net/packet/af_packet.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              PACKET - implements raw packet sockets.
   7  *
   8  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  11  *
  12  * Fixes:
  13  *              Alan Cox        :       verify_area() now used correctly
  14  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
  15  *              Alan Cox        :       tidied skbuff lists.
  16  *              Alan Cox        :       Now uses generic datagram routines I
  17  *                                      added. Also fixed the peek/read crash
  18  *                                      from all old Linux datagram code.
  19  *              Alan Cox        :       Uses the improved datagram code.
  20  *              Alan Cox        :       Added NULL's for socket options.
  21  *              Alan Cox        :       Re-commented the code.
  22  *              Alan Cox        :       Use new kernel side addressing
  23  *              Rob Janssen     :       Correct MTU usage.
  24  *              Dave Platt      :       Counter leaks caused by incorrect
  25  *                                      interrupt locking and some slightly
  26  *                                      dubious gcc output. Can you read
  27  *                                      compiler: it said _VOLATILE_
  28  *      Richard Kooijman        :       Timestamp fixes.
  29  *              Alan Cox        :       New buffers. Use sk->mac.raw.
  30  *              Alan Cox        :       sendmsg/recvmsg support.
  31  *              Alan Cox        :       Protocol setting support
  32  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
  33  *      Cyrus Durgin            :       Fixed kerneld for kmod.
  34  *      Michal Ostrowski        :       Module initialization cleanup.
  35  *         Ulises Alonso        :       Frame number limit removal and
  36  *                                      packet_set_ring memory leak.
  37  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
  38  *                                      The convention is that longer addresses
  39  *                                      will simply extend the hardware address
  40  *                                      byte arrays at the end of sockaddr_ll
  41  *                                      and packet_mreq.
  42  *              Johann Baudy    :       Added TX RING.
  43  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
  44  *                                      layer.
  45  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
  46  *
  47  *
  48  *              This program is free software; you can redistribute it and/or
  49  *              modify it under the terms of the GNU General Public License
  50  *              as published by the Free Software Foundation; either version
  51  *              2 of the License, or (at your option) any later version.
  52  *
  53  */
  54
  55 #include <linux/types.h>
  56 #include <linux/mm.h>
  57 #include <linux/capability.h>
  58 #include <linux/fcntl.h>
  59 #include <linux/socket.h>
  60 #include <linux/in.h>
  61 #include <linux/inet.h>
  62 #include <linux/netdevice.h>
  63 #include <linux/if_packet.h>
  64 #include <linux/wireless.h>
  65 #include <linux/kernel.h>
  66 #include <linux/kmod.h>
  67 #include <linux/slab.h>
  68 #include <linux/vmalloc.h>
  69 #include <net/net_namespace.h>
  70 #include <net/ip.h>
  71 #include <net/protocol.h>
  72 #include <linux/skbuff.h>
  73 #include <net/sock.h>
  74 #include <linux/errno.h>
  75 #include <linux/timer.h>
  76 #include <linux/uaccess.h>
  77 #include <asm/ioctls.h>
  78 #include <asm/page.h>
  79 #include <asm/cacheflush.h>
  80 #include <asm/io.h>
  81 #include <linux/proc_fs.h>
  82 #include <linux/seq_file.h>
  83 #include <linux/poll.h>
  84 #include <linux/module.h>
  85 #include <linux/init.h>
  86 #include <linux/mutex.h>
  87 #include <linux/if_vlan.h>
  88 #include <linux/virtio_net.h>
  89 #include <linux/errqueue.h>
  90 #include <linux/net_tstamp.h>
  91 #include <linux/percpu.h>
  92 #ifdef CONFIG_INET
  93 #include <net/inet_common.h>
  94 #endif
  95 #include <linux/bpf.h>
  96 #include <net/compat.h>
  97
  98 #include "internal.h"
  99
 100 /*
 101    Assumptions:
 102    - if device has no dev->hard_header routine, it adds and removes ll header
 103      inside itself. In this case ll header is invisible outside of device,
 104      but higher levels still should reserve dev->hard_header_len.
 105      Some devices are enough clever to reallocate skb, when header
 106      will not fit to reserved space (tunnel), another ones are silly
 107      (PPP).
 108    - packet socket receives packets with pulled ll header,
 109      so that SOCK_RAW should push it back.
 110
 111 On receive:
 112 -----------
 113
 114 Incoming, dev->hard_header!=NULL
 115    mac_header -> ll header
 116    data       -> data
 117
 118 Outgoing, dev->hard_header!=NULL
 119    mac_header -> ll header
 120    data       -> ll header
 121
 122 Incoming, dev->hard_header==NULL
 123    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 124                  header.  PPP makes it, that is wrong, because introduce
 125                  assymetry between rx and tx paths.
 126    data       -> data
 127
 128 Outgoing, dev->hard_header==NULL
 129    mac_header -> data. ll header is still not built!
 130    data       -> data
 131
 132 Resume
 133   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 134
 135
 136 On transmit:
 137 ------------
 138
 139 dev->hard_header != NULL
 140    mac_header -> ll header
 141    data       -> ll header
 142
 143 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 144    mac_header -> data
 145    data       -> data
 146
 147    We should set nh.raw on output to correct posistion,
 148    packet classifier depends on it.
 149  */
 150
 151 /* Private packet socket structures. */
 152
 153 /* identical to struct packet_mreq except it has
 154  * a longer address field.
 155  */
 156 struct packet_mreq_max {
 157         int             mr_ifindex;
 158         unsigned short  mr_type;
 159         unsigned short  mr_alen;
 160         unsigned char   mr_address[MAX_ADDR_LEN];
 161 };
 162
 163 union tpacket_uhdr {
 164         struct tpacket_hdr  *h1;
 165         struct tpacket2_hdr *h2;
 166         struct tpacket3_hdr *h3;
 167         void *raw;
 168 };
 169
 170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 171                 int closing, int tx_ring);
 172
 173 #define V3_ALIGNMENT    (8)
 174
 175 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 176
 177 #define BLK_PLUS_PRIV(sz_of_priv) \
 178         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 179
 180 #define PGV_FROM_VMALLOC 1
 181
 182 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 183 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 184 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 185 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 186 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 187 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 188 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 189
 190 struct packet_sock;
 191 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 193                        struct packet_type *pt, struct net_device *orig_dev);
 194
 195 static void *packet_previous_frame(struct packet_sock *po,
 196                 struct packet_ring_buffer *rb,
 197                 int status);
 198 static void packet_increment_head(struct packet_ring_buffer *buff);
 199 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 200                         struct tpacket_block_desc *);
 201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 202                         struct packet_sock *);
 203 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 204                 struct packet_sock *, unsigned int status);
 205 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 206 static void prb_open_block(struct tpacket_kbdq_core *,
 207                 struct tpacket_block_desc *);
 208 static void prb_retire_rx_blk_timer_expired(unsigned long);
 209 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 210 static void prb_init_blk_timer(struct packet_sock *,
 211                 struct tpacket_kbdq_core *,
 212                 void (*func) (unsigned long));
 213 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 214 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 215                 struct tpacket3_hdr *);
 216 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 217                 struct tpacket3_hdr *);
 218 static void packet_flush_mclist(struct sock *sk);
 219
 220 struct packet_skb_cb {
 221         union {
 222                 struct sockaddr_pkt pkt;
 223                 union {
 224                         /* Trick: alias skb original length with
 225                          * ll.sll_family and ll.protocol in order
 226                          * to save room.
 227                          */
 228                         unsigned int origlen;
 229                         struct sockaddr_ll ll;
 230                 };
 231         } sa;
 232 };
 233
 234 #define vio_le() virtio_legacy_is_little_endian()
 235
 236 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 237
 238 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 239 #define GET_PBLOCK_DESC(x, bid) \
 240         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 241 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 242         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 243 #define GET_NEXT_PRB_BLK_NUM(x) \
 244         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 245         ((x)->kactive_blk_num+1) : 0)
 246
 247 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 248 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 249
 250 static int packet_direct_xmit(struct sk_buff *skb)
 251 {
 252         struct net_device *dev = skb->dev;
 253         struct sk_buff *orig_skb = skb;
 254         struct netdev_queue *txq;
 255         int ret = NETDEV_TX_BUSY;
 256
 257         if (unlikely(!netif_running(dev) ||
 258                      !netif_carrier_ok(dev)))
 259                 goto drop;
 260
 261         skb = validate_xmit_skb_list(skb, dev);
 262         if (skb != orig_skb)
 263                 goto drop;
 264
 265         txq = skb_get_tx_queue(dev, skb);
 266
 267         local_bh_disable();
 268
 269         HARD_TX_LOCK(dev, txq, smp_processor_id());
 270         if (!netif_xmit_frozen_or_drv_stopped(txq))
 271                 ret = netdev_start_xmit(skb, dev, txq, false);
 272         HARD_TX_UNLOCK(dev, txq);
 273
 274         local_bh_enable();
 275
 276         if (!dev_xmit_complete(ret))
 277                 kfree_skb(skb);
 278
 279         return ret;
 280 drop:
 281         atomic_long_inc(&dev->tx_dropped);
 282         kfree_skb_list(skb);
 283         return NET_XMIT_DROP;
 284 }
 285
 286 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
 287 {
 288         struct net_device *dev;
 289
 290         rcu_read_lock();
 291         dev = rcu_dereference(po->cached_dev);
 292         if (likely(dev))
 293                 dev_hold(dev);
 294         rcu_read_unlock();
 295
 296         return dev;
 297 }
 298
 299 static void packet_cached_dev_assign(struct packet_sock *po,
 300                                      struct net_device *dev)
 301 {
 302         rcu_assign_pointer(po->cached_dev, dev);
 303 }
 304
 305 static void packet_cached_dev_reset(struct packet_sock *po)
 306 {
 307         RCU_INIT_POINTER(po->cached_dev, NULL);
 308 }
 309
 310 static bool packet_use_direct_xmit(const struct packet_sock *po)
 311 {
 312         return po->xmit == packet_direct_xmit;
 313 }
 314
 315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 316 {
 317         return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
 318 }
 319
 320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 321 {
 322         const struct net_device_ops *ops = dev->netdev_ops;
 323         u16 queue_index;
 324
 325         if (ops->ndo_select_queue) {
 326                 queue_index = ops->ndo_select_queue(dev, skb, NULL,
 327                                                     __packet_pick_tx_queue);
 328                 queue_index = netdev_cap_txqueue(dev, queue_index);
 329         } else {
 330                 queue_index = __packet_pick_tx_queue(dev, skb);
 331         }
 332
 333         skb_set_queue_mapping(skb, queue_index);
 334 }
 335
 336 /* register_prot_hook must be invoked with the po->bind_lock held,
 337  * or from a context in which asynchronous accesses to the packet
 338  * socket is not possible (packet_create()).
 339  */
 340 static void register_prot_hook(struct sock *sk)
 341 {
 342         struct packet_sock *po = pkt_sk(sk);
 343
 344         if (!po->running) {
 345                 if (po->fanout)
 346                         __fanout_link(sk, po);
 347                 else
 348                         dev_add_pack(&po->prot_hook);
 349
 350                 sock_hold(sk);
 351                 po->running = 1;
 352         }
 353 }
 354
 355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 356  * held.   If the sync parameter is true, we will temporarily drop
 357  * the po->bind_lock and do a synchronize_net to make sure no
 358  * asynchronous packet processing paths still refer to the elements
 359  * of po->prot_hook.  If the sync parameter is false, it is the
 360  * callers responsibility to take care of this.
 361  */
 362 static void __unregister_prot_hook(struct sock *sk, bool sync)
 363 {
 364         struct packet_sock *po = pkt_sk(sk);
 365
 366         po->running = 0;
 367
 368         if (po->fanout)
 369                 __fanout_unlink(sk, po);
 370         else
 371                 __dev_remove_pack(&po->prot_hook);
 372
 373         __sock_put(sk);
 374
 375         if (sync) {
 376                 spin_unlock(&po->bind_lock);
 377                 synchronize_net();
 378                 spin_lock(&po->bind_lock);
 379         }
 380 }
 381
 382 static void unregister_prot_hook(struct sock *sk, bool sync)
 383 {
 384         struct packet_sock *po = pkt_sk(sk);
 385
 386         if (po->running)
 387                 __unregister_prot_hook(sk, sync);
 388 }
 389
 390 static inline struct page * __pure pgv_to_page(void *addr)
 391 {
 392         if (is_vmalloc_addr(addr))
 393                 return vmalloc_to_page(addr);
 394         return virt_to_page(addr);
 395 }
 396
 397 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 398 {
 399         union tpacket_uhdr h;
 400
 401         h.raw = frame;
 402         switch (po->tp_version) {
 403         case TPACKET_V1:
 404                 h.h1->tp_status = status;
 405                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 406                 break;
 407         case TPACKET_V2:
 408                 h.h2->tp_status = status;
 409                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 410                 break;
 411         case TPACKET_V3:
 412         default:
 413                 WARN(1, "TPACKET version not supported.\n");
 414                 BUG();
 415         }
 416
 417         smp_wmb();
 418 }
 419
 420 static int __packet_get_status(struct packet_sock *po, void *frame)
 421 {
 422         union tpacket_uhdr h;
 423
 424         smp_rmb();
 425
 426         h.raw = frame;
 427         switch (po->tp_version) {
 428         case TPACKET_V1:
 429                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 430                 return h.h1->tp_status;
 431         case TPACKET_V2:
 432                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 433                 return h.h2->tp_status;
 434         case TPACKET_V3:
 435         default:
 436                 WARN(1, "TPACKET version not supported.\n");
 437                 BUG();
 438                 return 0;
 439         }
 440 }
 441
 442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 443                                    unsigned int flags)
 444 {
 445         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 446
 447         if (shhwtstamps &&
 448             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 449             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 450                 return TP_STATUS_TS_RAW_HARDWARE;
 451
 452         if (ktime_to_timespec_cond(skb->tstamp, ts))
 453                 return TP_STATUS_TS_SOFTWARE;
 454
 455         return 0;
 456 }
 457
 458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 459                                     struct sk_buff *skb)
 460 {
 461         union tpacket_uhdr h;
 462         struct timespec ts;
 463         __u32 ts_status;
 464
 465         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 466                 return 0;
 467
 468         h.raw = frame;
 469         switch (po->tp_version) {
 470         case TPACKET_V1:
 471                 h.h1->tp_sec = ts.tv_sec;
 472                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 473                 break;
 474         case TPACKET_V2:
 475                 h.h2->tp_sec = ts.tv_sec;
 476                 h.h2->tp_nsec = ts.tv_nsec;
 477                 break;
 478         case TPACKET_V3:
 479         default:
 480                 WARN(1, "TPACKET version not supported.\n");
 481                 BUG();
 482         }
 483
 484         /* one flush is safe, as both fields always lie on the same cacheline */
 485         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 486         smp_wmb();
 487
 488         return ts_status;
 489 }
 490
 491 static void *packet_lookup_frame(struct packet_sock *po,
 492                 struct packet_ring_buffer *rb,
 493                 unsigned int position,
 494                 int status)
 495 {
 496         unsigned int pg_vec_pos, frame_offset;
 497         union tpacket_uhdr h;
 498
 499         pg_vec_pos = position / rb->frames_per_block;
 500         frame_offset = position % rb->frames_per_block;
 501
 502         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 503                 (frame_offset * rb->frame_size);
 504
 505         if (status != __packet_get_status(po, h.raw))
 506                 return NULL;
 507
 508         return h.raw;
 509 }
 510
 511 static void *packet_current_frame(struct packet_sock *po,
 512                 struct packet_ring_buffer *rb,
 513                 int status)
 514 {
 515         return packet_lookup_frame(po, rb, rb->head, status);
 516 }
 517
 518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 519 {
 520         del_timer_sync(&pkc->retire_blk_timer);
 521 }
 522
 523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 524                 struct sk_buff_head *rb_queue)
 525 {
 526         struct tpacket_kbdq_core *pkc;
 527
 528         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 529
 530         spin_lock_bh(&rb_queue->lock);
 531         pkc->delete_blk_timer = 1;
 532         spin_unlock_bh(&rb_queue->lock);
 533
 534         prb_del_retire_blk_timer(pkc);
 535 }
 536
 537 static void prb_init_blk_timer(struct packet_sock *po,
 538                 struct tpacket_kbdq_core *pkc,
 539                 void (*func) (unsigned long))
 540 {
 541         init_timer(&pkc->retire_blk_timer);
 542         pkc->retire_blk_timer.data = (long)po;
 543         pkc->retire_blk_timer.function = func;
 544         pkc->retire_blk_timer.expires = jiffies;
 545 }
 546
 547 static void prb_setup_retire_blk_timer(struct packet_sock *po)
 548 {
 549         struct tpacket_kbdq_core *pkc;
 550
 551         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 552         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 553 }
 554
 555 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 556                                 int blk_size_in_bytes)
 557 {
 558         struct net_device *dev;
 559         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 560         struct ethtool_link_ksettings ecmd;
 561         int err;
 562
 563         rtnl_lock();
 564         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 565         if (unlikely(!dev)) {
 566                 rtnl_unlock();
 567                 return DEFAULT_PRB_RETIRE_TOV;
 568         }
 569         err = __ethtool_get_link_ksettings(dev, &ecmd);
 570         rtnl_unlock();
 571         if (!err) {
 572                 /*
 573                  * If the link speed is so slow you don't really
 574                  * need to worry about perf anyways
 575                  */
 576                 if (ecmd.base.speed < SPEED_1000 ||
 577                     ecmd.base.speed == SPEED_UNKNOWN) {
 578                         return DEFAULT_PRB_RETIRE_TOV;
 579                 } else {
 580                         msec = 1;
 581                         div = ecmd.base.speed / 1000;
 582                 }
 583         }
 584
 585         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 586
 587         if (div)
 588                 mbits /= div;
 589
 590         tmo = mbits * msec;
 591
 592         if (div)
 593                 return tmo+1;
 594         return tmo;
 595 }
 596
 597 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 598                         union tpacket_req_u *req_u)
 599 {
 600         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 601 }
 602
 603 static void init_prb_bdqc(struct packet_sock *po,
 604                         struct packet_ring_buffer *rb,
 605                         struct pgv *pg_vec,
 606                         union tpacket_req_u *req_u)
 607 {
 608         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 609         struct tpacket_block_desc *pbd;
 610
 611         memset(p1, 0x0, sizeof(*p1));
 612
 613         p1->knxt_seq_num = 1;
 614         p1->pkbdq = pg_vec;
 615         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 616         p1->pkblk_start = pg_vec[0].buffer;
 617         p1->kblk_size = req_u->req3.tp_block_size;
 618         p1->knum_blocks = req_u->req3.tp_block_nr;
 619         p1->hdrlen = po->tp_hdrlen;
 620         p1->version = po->tp_version;
 621         p1->last_kactive_blk_num = 0;
 622         po->stats.stats3.tp_freeze_q_cnt = 0;
 623         if (req_u->req3.tp_retire_blk_tov)
 624                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 625         else
 626                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 627                                                 req_u->req3.tp_block_size);
 628         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 629         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 630
 631         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 632         prb_init_ft_ops(p1, req_u);
 633         prb_setup_retire_blk_timer(po);
 634         prb_open_block(p1, pbd);
 635 }
 636
 637 /*  Do NOT update the last_blk_num first.
 638  *  Assumes sk_buff_head lock is held.
 639  */
 640 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 641 {
 642         mod_timer(&pkc->retire_blk_timer,
 643                         jiffies + pkc->tov_in_jiffies);
 644         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 645 }
 646
 647 /*
 648  * Timer logic:
 649  * 1) We refresh the timer only when we open a block.
 650  *    By doing this we don't waste cycles refreshing the timer
 651  *        on packet-by-packet basis.
 652  *
 653  * With a 1MB block-size, on a 1Gbps line, it will take
 654  * i) ~8 ms to fill a block + ii) memcpy etc.
 655  * In this cut we are not accounting for the memcpy time.
 656  *
 657  * So, if the user sets the 'tmo' to 10ms then the timer
 658  * will never fire while the block is still getting filled
 659  * (which is what we want). However, the user could choose
 660  * to close a block early and that's fine.
 661  *
 662  * But when the timer does fire, we check whether or not to refresh it.
 663  * Since the tmo granularity is in msecs, it is not too expensive
 664  * to refresh the timer, lets say every '8' msecs.
 665  * Either the user can set the 'tmo' or we can derive it based on
 666  * a) line-speed and b) block-size.
 667  * prb_calc_retire_blk_tmo() calculates the tmo.
 668  *
 669  */
 670 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 671 {
 672         struct packet_sock *po = (struct packet_sock *)data;
 673         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 674         unsigned int frozen;
 675         struct tpacket_block_desc *pbd;
 676
 677         spin_lock(&po->sk.sk_receive_queue.lock);
 678
 679         frozen = prb_queue_frozen(pkc);
 680         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 681
 682         if (unlikely(pkc->delete_blk_timer))
 683                 goto out;
 684
 685         /* We only need to plug the race when the block is partially filled.
 686          * tpacket_rcv:
 687          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 688          *              copy_bits() is in progress ...
 689          *              timer fires on other cpu:
 690          *              we can't retire the current block because copy_bits
 691          *              is in progress.
 692          *
 693          */
 694         if (BLOCK_NUM_PKTS(pbd)) {
 695                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 696                         /* Waiting for skb_copy_bits to finish... */
 697                         cpu_relax();
 698                 }
 699         }
 700
 701         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 702                 if (!frozen) {
 703                         if (!BLOCK_NUM_PKTS(pbd)) {
 704                                 /* An empty block. Just refresh the timer. */
 705                                 goto refresh_timer;
 706                         }
 707                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 708                         if (!prb_dispatch_next_block(pkc, po))
 709                                 goto refresh_timer;
 710                         else
 711                                 goto out;
 712                 } else {
 713                         /* Case 1. Queue was frozen because user-space was
 714                          *         lagging behind.
 715                          */
 716                         if (prb_curr_blk_in_use(pkc, pbd)) {
 717                                 /*
 718                                  * Ok, user-space is still behind.
 719                                  * So just refresh the timer.
 720                                  */
 721                                 goto refresh_timer;
 722                         } else {
 723                                /* Case 2. queue was frozen,user-space caught up,
 724                                 * now the link went idle && the timer fired.
 725                                 * We don't have a block to close.So we open this
 726                                 * block and restart the timer.
 727                                 * opening a block thaws the queue,restarts timer
 728                                 * Thawing/timer-refresh is a side effect.
 729                                 */
 730                                 prb_open_block(pkc, pbd);
 731                                 goto out;
 732                         }
 733                 }
 734         }
 735
 736 refresh_timer:
 737         _prb_refresh_rx_retire_blk_timer(pkc);
 738
 739 out:
 740         spin_unlock(&po->sk.sk_receive_queue.lock);
 741 }
 742
 743 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 744                 struct tpacket_block_desc *pbd1, __u32 status)
 745 {
 746         /* Flush everything minus the block header */
 747
 748 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 749         u8 *start, *end;
 750
 751         start = (u8 *)pbd1;
 752
 753         /* Skip the block header(we know header WILL fit in 4K) */
 754         start += PAGE_SIZE;
 755
 756         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 757         for (; start < end; start += PAGE_SIZE)
 758                 flush_dcache_page(pgv_to_page(start));
 759
 760         smp_wmb();
 761 #endif
 762
 763         /* Now update the block status. */
 764
 765         BLOCK_STATUS(pbd1) = status;
 766
 767         /* Flush the block header */
 768
 769 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 770         start = (u8 *)pbd1;
 771         flush_dcache_page(pgv_to_page(start));
 772
 773         smp_wmb();
 774 #endif
 775 }
 776
 777 /*
 778  * Side effect:
 779  *
 780  * 1) flush the block
 781  * 2) Increment active_blk_num
 782  *
 783  * Note:We DONT refresh the timer on purpose.
 784  *      Because almost always the next block will be opened.
 785  */
 786 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 787                 struct tpacket_block_desc *pbd1,
 788                 struct packet_sock *po, unsigned int stat)
 789 {
 790         __u32 status = TP_STATUS_USER | stat;
 791
 792         struct tpacket3_hdr *last_pkt;
 793         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 794         struct sock *sk = &po->sk;
 795
 796         if (po->stats.stats3.tp_drops)
 797                 status |= TP_STATUS_LOSING;
 798
 799         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 800         last_pkt->tp_next_offset = 0;
 801
 802         /* Get the ts of the last pkt */
 803         if (BLOCK_NUM_PKTS(pbd1)) {
 804                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 805                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 806         } else {
 807                 /* Ok, we tmo'd - so get the current time.
 808                  *
 809                  * It shouldn't really happen as we don't close empty
 810                  * blocks. See prb_retire_rx_blk_timer_expired().
 811                  */
 812                 struct timespec ts;
 813                 getnstimeofday(&ts);
 814                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 815                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 816         }
 817
 818         smp_wmb();
 819
 820         /* Flush the block */
 821         prb_flush_block(pkc1, pbd1, status);
 822
 823         sk->sk_data_ready(sk);
 824
 825         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 826 }
 827
 828 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 829 {
 830         pkc->reset_pending_on_curr_blk = 0;
 831 }
 832
 833 /*
 834  * Side effect of opening a block:
 835  *
 836  * 1) prb_queue is thawed.
 837  * 2) retire_blk_timer is refreshed.
 838  *
 839  */
 840 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 841         struct tpacket_block_desc *pbd1)
 842 {
 843         struct timespec ts;
 844         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 845
 846         smp_rmb();
 847
 848         /* We could have just memset this but we will lose the
 849          * flexibility of making the priv area sticky
 850          */
 851
 852         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 853         BLOCK_NUM_PKTS(pbd1) = 0;
 854         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 855
 856         getnstimeofday(&ts);
 857
 858         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 859         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 860
 861         pkc1->pkblk_start = (char *)pbd1;
 862         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 863
 864         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 865         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 866
 867         pbd1->version = pkc1->version;
 868         pkc1->prev = pkc1->nxt_offset;
 869         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 870
 871         prb_thaw_queue(pkc1);
 872         _prb_refresh_rx_retire_blk_timer(pkc1);
 873
 874         smp_wmb();
 875 }
 876
 877 /*
 878  * Queue freeze logic:
 879  * 1) Assume tp_block_nr = 8 blocks.
 880  * 2) At time 't0', user opens Rx ring.
 881  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 882  * 4) user-space is either sleeping or processing block '0'.
 883  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 884  *    it will close block-7,loop around and try to fill block '0'.
 885  *    call-flow:
 886  *    __packet_lookup_frame_in_block
 887  *      prb_retire_current_block()
 888  *      prb_dispatch_next_block()
 889  *        |->(BLOCK_STATUS == USER) evaluates to true
 890  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 891  * 6) Now there are two cases:
 892  *    6.1) Link goes idle right after the queue is frozen.
 893  *         But remember, the last open_block() refreshed the timer.
 894  *         When this timer expires,it will refresh itself so that we can
 895  *         re-open block-0 in near future.
 896  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 897  *         case and __packet_lookup_frame_in_block will check if block-0
 898  *         is free and can now be re-used.
 899  */
 900 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 901                                   struct packet_sock *po)
 902 {
 903         pkc->reset_pending_on_curr_blk = 1;
 904         po->stats.stats3.tp_freeze_q_cnt++;
 905 }
 906
 907 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 908
 909 /*
 910  * If the next block is free then we will dispatch it
 911  * and return a good offset.
 912  * Else, we will freeze the queue.
 913  * So, caller must check the return value.
 914  */
 915 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 916                 struct packet_sock *po)
 917 {
 918         struct tpacket_block_desc *pbd;
 919
 920         smp_rmb();
 921
 922         /* 1. Get current block num */
 923         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 924
 925         /* 2. If this block is currently in_use then freeze the queue */
 926         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 927                 prb_freeze_queue(pkc, po);
 928                 return NULL;
 929         }
 930
 931         /*
 932          * 3.
 933          * open this block and return the offset where the first packet
 934          * needs to get stored.
 935          */
 936         prb_open_block(pkc, pbd);
 937         return (void *)pkc->nxt_offset;
 938 }
 939
 940 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 941                 struct packet_sock *po, unsigned int status)
 942 {
 943         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 944
 945         /* retire/close the current block */
 946         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 947                 /*
 948                  * Plug the case where copy_bits() is in progress on
 949                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 950                  * have space to copy the pkt in the current block and
 951                  * called prb_retire_current_block()
 952                  *
 953                  * We don't need to worry about the TMO case because
 954                  * the timer-handler already handled this case.
 955                  */
 956                 if (!(status & TP_STATUS_BLK_TMO)) {
 957                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 958                                 /* Waiting for skb_copy_bits to finish... */
 959                                 cpu_relax();
 960                         }
 961                 }
 962                 prb_close_block(pkc, pbd, po, status);
 963                 return;
 964         }
 965 }
 966
 967 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 968                                       struct tpacket_block_desc *pbd)
 969 {
 970         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 971 }
 972
 973 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 974 {
 975         return pkc->reset_pending_on_curr_blk;
 976 }
 977
 978 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 979 {
 980         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 981         atomic_dec(&pkc->blk_fill_in_prog);
 982 }
 983
 984 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 985                         struct tpacket3_hdr *ppd)
 986 {
 987         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 988 }
 989
 990 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 991                         struct tpacket3_hdr *ppd)
 992 {
 993         ppd->hv1.tp_rxhash = 0;
 994 }
 995
 996 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 997                         struct tpacket3_hdr *ppd)
 998 {
 999         if (skb_vlan_tag_present(pkc->skb)) {
1000                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1001                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1002                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1003         } else {
1004                 ppd->hv1.tp_vlan_tci = 0;
1005                 ppd->hv1.tp_vlan_tpid = 0;
1006                 ppd->tp_status = TP_STATUS_AVAILABLE;
1007         }
1008 }
1009
1010 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1011                         struct tpacket3_hdr *ppd)
1012 {
1013         ppd->hv1.tp_padding = 0;
1014         prb_fill_vlan_info(pkc, ppd);
1015
1016         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1017                 prb_fill_rxhash(pkc, ppd);
1018         else
1019                 prb_clear_rxhash(pkc, ppd);
1020 }
1021
1022 static void prb_fill_curr_block(char *curr,
1023                                 struct tpacket_kbdq_core *pkc,
1024                                 struct tpacket_block_desc *pbd,
1025                                 unsigned int len)
1026 {
1027         struct tpacket3_hdr *ppd;
1028
1029         ppd  = (struct tpacket3_hdr *)curr;
1030         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1031         pkc->prev = curr;
1032         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1033         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034         BLOCK_NUM_PKTS(pbd) += 1;
1035         atomic_inc(&pkc->blk_fill_in_prog);
1036         prb_run_all_ft_ops(pkc, ppd);
1037 }
1038
1039 /* Assumes caller has the sk->rx_queue.lock */
1040 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1041                                             struct sk_buff *skb,
1042                                                 int status,
1043                                             unsigned int len
1044                                             )
1045 {
1046         struct tpacket_kbdq_core *pkc;
1047         struct tpacket_block_desc *pbd;
1048         char *curr, *end;
1049
1050         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1051         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1052
1053         /* Queue is frozen when user space is lagging behind */
1054         if (prb_queue_frozen(pkc)) {
1055                 /*
1056                  * Check if that last block which caused the queue to freeze,
1057                  * is still in_use by user-space.
1058                  */
1059                 if (prb_curr_blk_in_use(pkc, pbd)) {
1060                         /* Can't record this packet */
1061                         return NULL;
1062                 } else {
1063                         /*
1064                          * Ok, the block was released by user-space.
1065                          * Now let's open that block.
1066                          * opening a block also thaws the queue.
1067                          * Thawing is a side effect.
1068                          */
1069                         prb_open_block(pkc, pbd);
1070                 }
1071         }
1072
1073         smp_mb();
1074         curr = pkc->nxt_offset;
1075         pkc->skb = skb;
1076         end = (char *)pbd + pkc->kblk_size;
1077
1078         /* first try the current block */
1079         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1080                 prb_fill_curr_block(curr, pkc, pbd, len);
1081                 return (void *)curr;
1082         }
1083
1084         /* Ok, close the current block */
1085         prb_retire_current_block(pkc, po, 0);
1086
1087         /* Now, try to dispatch the next block */
1088         curr = (char *)prb_dispatch_next_block(pkc, po);
1089         if (curr) {
1090                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1091                 prb_fill_curr_block(curr, pkc, pbd, len);
1092                 return (void *)curr;
1093         }
1094
1095         /*
1096          * No free blocks are available.user_space hasn't caught up yet.
1097          * Queue was just frozen and now this packet will get dropped.
1098          */
1099         return NULL;
1100 }
1101
1102 static void *packet_current_rx_frame(struct packet_sock *po,
1103                                             struct sk_buff *skb,
1104                                             int status, unsigned int len)
1105 {
1106         char *curr = NULL;
1107         switch (po->tp_version) {
1108         case TPACKET_V1:
1109         case TPACKET_V2:
1110                 curr = packet_lookup_frame(po, &po->rx_ring,
1111                                         po->rx_ring.head, status);
1112                 return curr;
1113         case TPACKET_V3:
1114                 return __packet_lookup_frame_in_block(po, skb, status, len);
1115         default:
1116                 WARN(1, "TPACKET version not supported\n");
1117                 BUG();
1118                 return NULL;
1119         }
1120 }
1121
1122 static void *prb_lookup_block(struct packet_sock *po,
1123                                      struct packet_ring_buffer *rb,
1124                                      unsigned int idx,
1125                                      int status)
1126 {
1127         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1128         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1129
1130         if (status != BLOCK_STATUS(pbd))
1131                 return NULL;
1132         return pbd;
1133 }
1134
1135 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1136 {
1137         unsigned int prev;
1138         if (rb->prb_bdqc.kactive_blk_num)
1139                 prev = rb->prb_bdqc.kactive_blk_num-1;
1140         else
1141                 prev = rb->prb_bdqc.knum_blocks-1;
1142         return prev;
1143 }
1144
1145 /* Assumes caller has held the rx_queue.lock */
1146 static void *__prb_previous_block(struct packet_sock *po,
1147                                          struct packet_ring_buffer *rb,
1148                                          int status)
1149 {
1150         unsigned int previous = prb_previous_blk_num(rb);
1151         return prb_lookup_block(po, rb, previous, status);
1152 }
1153
1154 static void *packet_previous_rx_frame(struct packet_sock *po,
1155                                              struct packet_ring_buffer *rb,
1156                                              int status)
1157 {
1158         if (po->tp_version <= TPACKET_V2)
1159                 return packet_previous_frame(po, rb, status);
1160
1161         return __prb_previous_block(po, rb, status);
1162 }
1163
1164 static void packet_increment_rx_head(struct packet_sock *po,
1165                                             struct packet_ring_buffer *rb)
1166 {
1167         switch (po->tp_version) {
1168         case TPACKET_V1:
1169         case TPACKET_V2:
1170                 return packet_increment_head(rb);
1171         case TPACKET_V3:
1172         default:
1173                 WARN(1, "TPACKET version not supported.\n");
1174                 BUG();
1175                 return;
1176         }
1177 }
1178
1179 static void *packet_previous_frame(struct packet_sock *po,
1180                 struct packet_ring_buffer *rb,
1181                 int status)
1182 {
1183         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1184         return packet_lookup_frame(po, rb, previous, status);
1185 }
1186
1187 static void packet_increment_head(struct packet_ring_buffer *buff)
1188 {
1189         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1190 }
1191
1192 static void packet_inc_pending(struct packet_ring_buffer *rb)
1193 {
1194         this_cpu_inc(*rb->pending_refcnt);
1195 }
1196
1197 static void packet_dec_pending(struct packet_ring_buffer *rb)
1198 {
1199         this_cpu_dec(*rb->pending_refcnt);
1200 }
1201
1202 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1203 {
1204         unsigned int refcnt = 0;
1205         int cpu;
1206
1207         /* We don't use pending refcount in rx_ring. */
1208         if (rb->pending_refcnt == NULL)
1209                 return 0;
1210
1211         for_each_possible_cpu(cpu)
1212                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1213
1214         return refcnt;
1215 }
1216
1217 static int packet_alloc_pending(struct packet_sock *po)
1218 {
1219         po->rx_ring.pending_refcnt = NULL;
1220
1221         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1222         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1223                 return -ENOBUFS;
1224
1225         return 0;
1226 }
1227
1228 static void packet_free_pending(struct packet_sock *po)
1229 {
1230         free_percpu(po->tx_ring.pending_refcnt);
1231 }
1232
1233 #define ROOM_POW_OFF    2
1234 #define ROOM_NONE       0x0
1235 #define ROOM_LOW        0x1
1236 #define ROOM_NORMAL     0x2
1237
1238 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1239 {
1240         int idx, len;
1241
1242         len = po->rx_ring.frame_max + 1;
1243         idx = po->rx_ring.head;
1244         if (pow_off)
1245                 idx += len >> pow_off;
1246         if (idx >= len)
1247                 idx -= len;
1248         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1249 }
1250
1251 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1252 {
1253         int idx, len;
1254
1255         len = po->rx_ring.prb_bdqc.knum_blocks;
1256         idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1257         if (pow_off)
1258                 idx += len >> pow_off;
1259         if (idx >= len)
1260                 idx -= len;
1261         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1262 }
1263
1264 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1265 {
1266         struct sock *sk = &po->sk;
1267         int ret = ROOM_NONE;
1268
1269         if (po->prot_hook.func != tpacket_rcv) {
1270                 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1271                                           - (skb ? skb->truesize : 0);
1272                 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1273                         return ROOM_NORMAL;
1274                 else if (avail > 0)
1275                         return ROOM_LOW;
1276                 else
1277                         return ROOM_NONE;
1278         }
1279
1280         if (po->tp_version == TPACKET_V3) {
1281                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1282                         ret = ROOM_NORMAL;
1283                 else if (__tpacket_v3_has_room(po, 0))
1284                         ret = ROOM_LOW;
1285         } else {
1286                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1287                         ret = ROOM_NORMAL;
1288                 else if (__tpacket_has_room(po, 0))
1289                         ret = ROOM_LOW;
1290         }
1291
1292         return ret;
1293 }
1294
1295 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1296 {
1297         int ret;
1298         bool has_room;
1299
1300         spin_lock_bh(&po->sk.sk_receive_queue.lock);
1301         ret = __packet_rcv_has_room(po, skb);
1302         has_room = ret == ROOM_NORMAL;
1303         if (po->pressure == has_room)
1304                 po->pressure = !has_room;
1305         spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1306
1307         return ret;
1308 }
1309
1310 static void packet_sock_destruct(struct sock *sk)
1311 {
1312         skb_queue_purge(&sk->sk_error_queue);
1313
1314         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1315         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1316
1317         if (!sock_flag(sk, SOCK_DEAD)) {
1318                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1319                 return;
1320         }
1321
1322         sk_refcnt_debug_dec(sk);
1323 }
1324
1325 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1326 {
1327         u32 rxhash;
1328         int i, count = 0;
1329
1330         rxhash = skb_get_hash(skb);
1331         for (i = 0; i < ROLLOVER_HLEN; i++)
1332                 if (po->rollover->history[i] == rxhash)
1333                         count++;
1334
1335         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1336         return count > (ROLLOVER_HLEN >> 1);
1337 }
1338
1339 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1340                                       struct sk_buff *skb,
1341                                       unsigned int num)
1342 {
1343         return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1344 }
1345
1346 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1347                                     struct sk_buff *skb,
1348                                     unsigned int num)
1349 {
1350         unsigned int val = atomic_inc_return(&f->rr_cur);
1351
1352         return val % num;
1353 }
1354
1355 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1356                                      struct sk_buff *skb,
1357                                      unsigned int num)
1358 {
1359         return smp_processor_id() % num;
1360 }
1361
1362 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1363                                      struct sk_buff *skb,
1364                                      unsigned int num)
1365 {
1366         return prandom_u32_max(num);
1367 }
1368
1369 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1370                                           struct sk_buff *skb,
1371                                           unsigned int idx, bool try_self,
1372                                           unsigned int num)
1373 {
1374         struct packet_sock *po, *po_next, *po_skip = NULL;
1375         unsigned int i, j, room = ROOM_NONE;
1376
1377         po = pkt_sk(f->arr[idx]);
1378
1379         if (try_self) {
1380                 room = packet_rcv_has_room(po, skb);
1381                 if (room == ROOM_NORMAL ||
1382                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1383                         return idx;
1384                 po_skip = po;
1385         }
1386
1387         i = j = min_t(int, po->rollover->sock, num - 1);
1388         do {
1389                 po_next = pkt_sk(f->arr[i]);
1390                 if (po_next != po_skip && !po_next->pressure &&
1391                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1392                         if (i != j)
1393                                 po->rollover->sock = i;
1394                         atomic_long_inc(&po->rollover->num);
1395                         if (room == ROOM_LOW)
1396                                 atomic_long_inc(&po->rollover->num_huge);
1397                         return i;
1398                 }
1399
1400                 if (++i == num)
1401                         i = 0;
1402         } while (i != j);
1403
1404         atomic_long_inc(&po->rollover->num_failed);
1405         return idx;
1406 }
1407
1408 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1409                                     struct sk_buff *skb,
1410                                     unsigned int num)
1411 {
1412         return skb_get_queue_mapping(skb) % num;
1413 }
1414
1415 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1416                                      struct sk_buff *skb,
1417                                      unsigned int num)
1418 {
1419         struct bpf_prog *prog;
1420         unsigned int ret = 0;
1421
1422         rcu_read_lock();
1423         prog = rcu_dereference(f->bpf_prog);
1424         if (prog)
1425                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1426         rcu_read_unlock();
1427
1428         return ret;
1429 }
1430
1431 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1432 {
1433         return f->flags & (flag >> 8);
1434 }
1435
1436 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1437                              struct packet_type *pt, struct net_device *orig_dev)
1438 {
1439         struct packet_fanout *f = pt->af_packet_priv;
1440         unsigned int num = READ_ONCE(f->num_members);
1441         struct net *net = read_pnet(&f->net);
1442         struct packet_sock *po;
1443         unsigned int idx;
1444
1445         if (!net_eq(dev_net(dev), net) || !num) {
1446                 kfree_skb(skb);
1447                 return 0;
1448         }
1449
1450         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1451                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1452                 if (!skb)
1453                         return 0;
1454         }
1455         switch (f->type) {
1456         case PACKET_FANOUT_HASH:
1457         default:
1458                 idx = fanout_demux_hash(f, skb, num);
1459                 break;
1460         case PACKET_FANOUT_LB:
1461                 idx = fanout_demux_lb(f, skb, num);
1462                 break;
1463         case PACKET_FANOUT_CPU:
1464                 idx = fanout_demux_cpu(f, skb, num);
1465                 break;
1466         case PACKET_FANOUT_RND:
1467                 idx = fanout_demux_rnd(f, skb, num);
1468                 break;
1469         case PACKET_FANOUT_QM:
1470                 idx = fanout_demux_qm(f, skb, num);
1471                 break;
1472         case PACKET_FANOUT_ROLLOVER:
1473                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1474                 break;
1475         case PACKET_FANOUT_CBPF:
1476         case PACKET_FANOUT_EBPF:
1477                 idx = fanout_demux_bpf(f, skb, num);
1478                 break;
1479         }
1480
1481         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1482                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1483
1484         po = pkt_sk(f->arr[idx]);
1485         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1486 }
1487
1488 DEFINE_MUTEX(fanout_mutex);
1489 EXPORT_SYMBOL_GPL(fanout_mutex);
1490 static LIST_HEAD(fanout_list);
1491
1492 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1493 {
1494         struct packet_fanout *f = po->fanout;
1495
1496         spin_lock(&f->lock);
1497         f->arr[f->num_members] = sk;
1498         smp_wmb();
1499         f->num_members++;
1500         if (f->num_members == 1)
1501                 dev_add_pack(&f->prot_hook);
1502         spin_unlock(&f->lock);
1503 }
1504
1505 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1506 {
1507         struct packet_fanout *f = po->fanout;
1508         int i;
1509
1510         spin_lock(&f->lock);
1511         for (i = 0; i < f->num_members; i++) {
1512                 if (f->arr[i] == sk)
1513                         break;
1514         }
1515         BUG_ON(i >= f->num_members);
1516         f->arr[i] = f->arr[f->num_members - 1];
1517         f->num_members--;
1518         if (f->num_members == 0)
1519                 __dev_remove_pack(&f->prot_hook);
1520         spin_unlock(&f->lock);
1521 }
1522
1523 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1524 {
1525         if (sk->sk_family != PF_PACKET)
1526                 return false;
1527
1528         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1529 }
1530
1531 static void fanout_init_data(struct packet_fanout *f)
1532 {
1533         switch (f->type) {
1534         case PACKET_FANOUT_LB:
1535                 atomic_set(&f->rr_cur, 0);
1536                 break;
1537         case PACKET_FANOUT_CBPF:
1538         case PACKET_FANOUT_EBPF:
1539                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1540                 break;
1541         }
1542 }
1543
1544 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1545 {
1546         struct bpf_prog *old;
1547
1548         spin_lock(&f->lock);
1549         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1550         rcu_assign_pointer(f->bpf_prog, new);
1551         spin_unlock(&f->lock);
1552
1553         if (old) {
1554                 synchronize_net();
1555                 bpf_prog_destroy(old);
1556         }
1557 }
1558
1559 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1560                                 unsigned int len)
1561 {
1562         struct bpf_prog *new;
1563         struct sock_fprog fprog;
1564         int ret;
1565
1566         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1567                 return -EPERM;
1568         if (len != sizeof(fprog))
1569                 return -EINVAL;
1570         if (copy_from_user(&fprog, data, len))
1571                 return -EFAULT;
1572
1573         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1574         if (ret)
1575                 return ret;
1576
1577         __fanout_set_data_bpf(po->fanout, new);
1578         return 0;
1579 }
1580
1581 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1582                                 unsigned int len)
1583 {
1584         struct bpf_prog *new;
1585         u32 fd;
1586
1587         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1588                 return -EPERM;
1589         if (len != sizeof(fd))
1590                 return -EINVAL;
1591         if (copy_from_user(&fd, data, len))
1592                 return -EFAULT;
1593
1594         new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1595         if (IS_ERR(new))
1596                 return PTR_ERR(new);
1597
1598         __fanout_set_data_bpf(po->fanout, new);
1599         return 0;
1600 }
1601
1602 static int fanout_set_data(struct packet_sock *po, char __user *data,
1603                            unsigned int len)
1604 {
1605         switch (po->fanout->type) {
1606         case PACKET_FANOUT_CBPF:
1607                 return fanout_set_data_cbpf(po, data, len);
1608         case PACKET_FANOUT_EBPF:
1609                 return fanout_set_data_ebpf(po, data, len);
1610         default:
1611                 return -EINVAL;
1612         };
1613 }
1614
1615 static void fanout_release_data(struct packet_fanout *f)
1616 {
1617         switch (f->type) {
1618         case PACKET_FANOUT_CBPF:
1619         case PACKET_FANOUT_EBPF:
1620                 __fanout_set_data_bpf(f, NULL);
1621         };
1622 }
1623
1624 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1625 {
1626         struct packet_rollover *rollover = NULL;
1627         struct packet_sock *po = pkt_sk(sk);
1628         struct packet_fanout *f, *match;
1629         u8 type = type_flags & 0xff;
1630         u8 flags = type_flags >> 8;
1631         int err;
1632
1633         switch (type) {
1634         case PACKET_FANOUT_ROLLOVER:
1635                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1636                         return -EINVAL;
1637         case PACKET_FANOUT_HASH:
1638         case PACKET_FANOUT_LB:
1639         case PACKET_FANOUT_CPU:
1640         case PACKET_FANOUT_RND:
1641         case PACKET_FANOUT_QM:
1642         case PACKET_FANOUT_CBPF:
1643         case PACKET_FANOUT_EBPF:
1644                 break;
1645         default:
1646                 return -EINVAL;
1647         }
1648
1649         mutex_lock(&fanout_mutex);
1650
1651         err = -EINVAL;
1652         if (!po->running)
1653                 goto out;
1654
1655         err = -EALREADY;
1656         if (po->fanout)
1657                 goto out;
1658
1659         if (type == PACKET_FANOUT_ROLLOVER ||
1660             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1661                 err = -ENOMEM;
1662                 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1663                 if (!rollover)
1664                         goto out;
1665                 atomic_long_set(&rollover->num, 0);
1666                 atomic_long_set(&rollover->num_huge, 0);
1667                 atomic_long_set(&rollover->num_failed, 0);
1668                 po->rollover = rollover;
1669         }
1670
1671         match = NULL;
1672         list_for_each_entry(f, &fanout_list, list) {
1673                 if (f->id == id &&
1674                     read_pnet(&f->net) == sock_net(sk)) {
1675                         match = f;
1676                         break;
1677                 }
1678         }
1679         err = -EINVAL;
1680         if (match && match->flags != flags)
1681                 goto out;
1682         if (!match) {
1683                 err = -ENOMEM;
1684                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1685                 if (!match)
1686                         goto out;
1687                 write_pnet(&match->net, sock_net(sk));
1688                 match->id = id;
1689                 match->type = type;
1690                 match->flags = flags;
1691                 INIT_LIST_HEAD(&match->list);
1692                 spin_lock_init(&match->lock);
1693                 atomic_set(&match->sk_ref, 0);
1694                 fanout_init_data(match);
1695                 match->prot_hook.type = po->prot_hook.type;
1696                 match->prot_hook.dev = po->prot_hook.dev;
1697                 match->prot_hook.func = packet_rcv_fanout;
1698                 match->prot_hook.af_packet_priv = match;
1699                 match->prot_hook.id_match = match_fanout_group;
1700                 list_add(&match->list, &fanout_list);
1701         }
1702         err = -EINVAL;
1703         if (match->type == type &&
1704             match->prot_hook.type == po->prot_hook.type &&
1705             match->prot_hook.dev == po->prot_hook.dev) {
1706                 err = -ENOSPC;
1707                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1708                         __dev_remove_pack(&po->prot_hook);
1709                         po->fanout = match;
1710                         atomic_inc(&match->sk_ref);
1711                         __fanout_link(sk, po);
1712                         err = 0;
1713                 }
1714         }
1715 out:
1716         if (err && rollover) {
1717                 kfree(rollover);
1718                 po->rollover = NULL;
1719         }
1720         mutex_unlock(&fanout_mutex);
1721         return err;
1722 }
1723
1724 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1725  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1726  * It is the responsibility of the caller to call fanout_release_data() and
1727  * free the returned packet_fanout (after synchronize_net())
1728  */
1729 static struct packet_fanout *fanout_release(struct sock *sk)
1730 {
1731         struct packet_sock *po = pkt_sk(sk);
1732         struct packet_fanout *f;
1733
1734         mutex_lock(&fanout_mutex);
1735         f = po->fanout;
1736         if (f) {
1737                 po->fanout = NULL;
1738
1739                 if (atomic_dec_and_test(&f->sk_ref))
1740                         list_del(&f->list);
1741                 else
1742                         f = NULL;
1743
1744                 if (po->rollover)
1745                         kfree_rcu(po->rollover, rcu);
1746         }
1747         mutex_unlock(&fanout_mutex);
1748
1749         return f;
1750 }
1751
1752 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1753                                           struct sk_buff *skb)
1754 {
1755         /* Earlier code assumed this would be a VLAN pkt, double-check
1756          * this now that we have the actual packet in hand. We can only
1757          * do this check on Ethernet devices.
1758          */
1759         if (unlikely(dev->type != ARPHRD_ETHER))
1760                 return false;
1761
1762         skb_reset_mac_header(skb);
1763         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1764 }
1765
1766 static const struct proto_ops packet_ops;
1767
1768 static const struct proto_ops packet_ops_spkt;
1769
1770 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1771                            struct packet_type *pt, struct net_device *orig_dev)
1772 {
1773         struct sock *sk;
1774         struct sockaddr_pkt *spkt;
1775
1776         /*
1777          *      When we registered the protocol we saved the socket in the data
1778          *      field for just this event.
1779          */
1780
1781         sk = pt->af_packet_priv;
1782
1783         /*
1784          *      Yank back the headers [hope the device set this
1785          *      right or kerboom...]
1786          *
1787          *      Incoming packets have ll header pulled,
1788          *      push it back.
1789          *
1790          *      For outgoing ones skb->data == skb_mac_header(skb)
1791          *      so that this procedure is noop.
1792          */
1793
1794         if (skb->pkt_type == PACKET_LOOPBACK)
1795                 goto out;
1796
1797         if (!net_eq(dev_net(dev), sock_net(sk)))
1798                 goto out;
1799
1800         skb = skb_share_check(skb, GFP_ATOMIC);
1801         if (skb == NULL)
1802                 goto oom;
1803
1804         /* drop any routing info */
1805         skb_dst_drop(skb);
1806
1807         /* drop conntrack reference */
1808         nf_reset(skb);
1809
1810         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1811
1812         skb_push(skb, skb->data - skb_mac_header(skb));
1813
1814         /*
1815          *      The SOCK_PACKET socket receives _all_ frames.
1816          */
1817
1818         spkt->spkt_family = dev->type;
1819         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1820         spkt->spkt_protocol = skb->protocol;
1821
1822         /*
1823          *      Charge the memory to the socket. This is done specifically
1824          *      to prevent sockets using all the memory up.
1825          */
1826
1827         if (sock_queue_rcv_skb(sk, skb) == 0)
1828                 return 0;
1829
1830 out:
1831         kfree_skb(skb);
1832 oom:
1833         return 0;
1834 }
1835
1836
1837 /*
1838  *      Output a raw packet to a device layer. This bypasses all the other
1839  *      protocol layers and you must therefore supply it with a complete frame
1840  */
1841
1842 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1843                                size_t len)
1844 {
1845         struct sock *sk = sock->sk;
1846         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1847         struct sk_buff *skb = NULL;
1848         struct net_device *dev;
1849         struct sockcm_cookie sockc;
1850         __be16 proto = 0;
1851         int err;
1852         int extra_len = 0;
1853
1854         /*
1855          *      Get and verify the address.
1856          */
1857
1858         if (saddr) {
1859                 if (msg->msg_namelen < sizeof(struct sockaddr))
1860                         return -EINVAL;
1861                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1862                         proto = saddr->spkt_protocol;
1863         } else
1864                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1865
1866         /*
1867          *      Find the device first to size check it
1868          */
1869
1870         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1871 retry:
1872         rcu_read_lock();
1873         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1874         err = -ENODEV;
1875         if (dev == NULL)
1876                 goto out_unlock;
1877
1878         err = -ENETDOWN;
1879         if (!(dev->flags & IFF_UP))
1880                 goto out_unlock;
1881
1882         /*
1883          * You may not queue a frame bigger than the mtu. This is the lowest level
1884          * raw protocol and you must do your own fragmentation at this level.
1885          */
1886
1887         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1888                 if (!netif_supports_nofcs(dev)) {
1889                         err = -EPROTONOSUPPORT;
1890                         goto out_unlock;
1891                 }
1892                 extra_len = 4; /* We're doing our own CRC */
1893         }
1894
1895         err = -EMSGSIZE;
1896         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1897                 goto out_unlock;
1898
1899         if (!skb) {
1900                 size_t reserved = LL_RESERVED_SPACE(dev);
1901                 int tlen = dev->needed_tailroom;
1902                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1903
1904                 rcu_read_unlock();
1905                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1906                 if (skb == NULL)
1907                         return -ENOBUFS;
1908                 /* FIXME: Save some space for broken drivers that write a hard
1909                  * header at transmission time by themselves. PPP is the notable
1910                  * one here. This should really be fixed at the driver level.
1911                  */
1912                 skb_reserve(skb, reserved);
1913                 skb_reset_network_header(skb);
1914
1915                 /* Try to align data part correctly */
1916                 if (hhlen) {
1917                         skb->data -= hhlen;
1918                         skb->tail -= hhlen;
1919                         if (len < hhlen)
1920                                 skb_reset_network_header(skb);
1921                 }
1922                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1923                 if (err)
1924                         goto out_free;
1925                 goto retry;
1926         }
1927
1928         if (!dev_validate_header(dev, skb->data, len)) {
1929                 err = -EINVAL;
1930                 goto out_unlock;
1931         }
1932         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1933             !packet_extra_vlan_len_allowed(dev, skb)) {
1934                 err = -EMSGSIZE;
1935                 goto out_unlock;
1936         }
1937
1938         sockc.tsflags = sk->sk_tsflags;
1939         if (msg->msg_controllen) {
1940                 err = sock_cmsg_send(sk, msg, &sockc);
1941                 if (unlikely(err))
1942                         goto out_unlock;
1943         }
1944
1945         skb->protocol = proto;
1946         skb->dev = dev;
1947         skb->priority = sk->sk_priority;
1948         skb->mark = sk->sk_mark;
1949
1950         sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
1951
1952         if (unlikely(extra_len == 4))
1953                 skb->no_fcs = 1;
1954
1955         skb_probe_transport_header(skb, 0);
1956
1957         dev_queue_xmit(skb);
1958         rcu_read_unlock();
1959         return len;
1960
1961 out_unlock:
1962         rcu_read_unlock();
1963 out_free:
1964         kfree_skb(skb);
1965         return err;
1966 }
1967
1968 static unsigned int run_filter(struct sk_buff *skb,
1969                                const struct sock *sk,
1970                                unsigned int res)
1971 {
1972         struct sk_filter *filter;
1973
1974         rcu_read_lock();
1975         filter = rcu_dereference(sk->sk_filter);
1976         if (filter != NULL)
1977                 res = bpf_prog_run_clear_cb(filter->prog, skb);
1978         rcu_read_unlock();
1979
1980         return res;
1981 }
1982
1983 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
1984                            size_t *len)
1985 {
1986         struct virtio_net_hdr vnet_hdr;
1987
1988         if (*len < sizeof(vnet_hdr))
1989                 return -EINVAL;
1990         *len -= sizeof(vnet_hdr);
1991
1992         if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true))
1993                 return -EINVAL;
1994
1995         return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
1996 }
1997
1998 /*
1999  * This function makes lazy skb cloning in hope that most of packets
2000  * are discarded by BPF.
2001  *
2002  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2003  * and skb->cb are mangled. It works because (and until) packets
2004  * falling here are owned by current CPU. Output packets are cloned
2005  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2006  * sequencially, so that if we return skb to original state on exit,
2007  * we will not harm anyone.
2008  */
2009
2010 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2011                       struct packet_type *pt, struct net_device *orig_dev)
2012 {
2013         struct sock *sk;
2014         struct sockaddr_ll *sll;
2015         struct packet_sock *po;
2016         u8 *skb_head = skb->data;
2017         int skb_len = skb->len;
2018         unsigned int snaplen, res;
2019         bool is_drop_n_account = false;
2020
2021         if (skb->pkt_type == PACKET_LOOPBACK)
2022                 goto drop;
2023
2024         sk = pt->af_packet_priv;
2025         po = pkt_sk(sk);
2026
2027         if (!net_eq(dev_net(dev), sock_net(sk)))
2028                 goto drop;
2029
2030         skb->dev = dev;
2031
2032         if (dev->header_ops) {
2033                 /* The device has an explicit notion of ll header,
2034                  * exported to higher levels.
2035                  *
2036                  * Otherwise, the device hides details of its frame
2037                  * structure, so that corresponding packet head is
2038                  * never delivered to user.
2039                  */
2040                 if (sk->sk_type != SOCK_DGRAM)
2041                         skb_push(skb, skb->data - skb_mac_header(skb));
2042                 else if (skb->pkt_type == PACKET_OUTGOING) {
2043                         /* Special case: outgoing packets have ll header at head */
2044                         skb_pull(skb, skb_network_offset(skb));
2045                 }
2046         }
2047
2048         snaplen = skb->len;
2049
2050         res = run_filter(skb, sk, snaplen);
2051         if (!res)
2052                 goto drop_n_restore;
2053         if (snaplen > res)
2054                 snaplen = res;
2055
2056         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2057                 goto drop_n_acct;
2058
2059         if (skb_shared(skb)) {
2060                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2061                 if (nskb == NULL)
2062                         goto drop_n_acct;
2063
2064                 if (skb_head != skb->data) {
2065                         skb->data = skb_head;
2066                         skb->len = skb_len;
2067                 }
2068                 consume_skb(skb);
2069                 skb = nskb;
2070         }
2071
2072         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2073
2074         sll = &PACKET_SKB_CB(skb)->sa.ll;
2075         sll->sll_hatype = dev->type;
2076         sll->sll_pkttype = skb->pkt_type;
2077         if (unlikely(po->origdev))
2078                 sll->sll_ifindex = orig_dev->ifindex;
2079         else
2080                 sll->sll_ifindex = dev->ifindex;
2081
2082         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2083
2084         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2085          * Use their space for storing the original skb length.
2086          */
2087         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2088
2089         if (pskb_trim(skb, snaplen))
2090                 goto drop_n_acct;
2091
2092         skb_set_owner_r(skb, sk);
2093         skb->dev = NULL;
2094         skb_dst_drop(skb);
2095
2096         /* drop conntrack reference */
2097         nf_reset(skb);
2098
2099         spin_lock(&sk->sk_receive_queue.lock);
2100         po->stats.stats1.tp_packets++;
2101         sock_skb_set_dropcount(sk, skb);
2102         __skb_queue_tail(&sk->sk_receive_queue, skb);
2103         spin_unlock(&sk->sk_receive_queue.lock);
2104         sk->sk_data_ready(sk);
2105         return 0;
2106
2107 drop_n_acct:
2108         is_drop_n_account = true;
2109         spin_lock(&sk->sk_receive_queue.lock);
2110         po->stats.stats1.tp_drops++;
2111         atomic_inc(&sk->sk_drops);
2112         spin_unlock(&sk->sk_receive_queue.lock);
2113
2114 drop_n_restore:
2115         if (skb_head != skb->data && skb_shared(skb)) {
2116                 skb->data = skb_head;
2117                 skb->len = skb_len;
2118         }
2119 drop:
2120         if (!is_drop_n_account)
2121                 consume_skb(skb);
2122         else
2123                 kfree_skb(skb);
2124         return 0;
2125 }
2126
2127 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2128                        struct packet_type *pt, struct net_device *orig_dev)
2129 {
2130         struct sock *sk;
2131         struct packet_sock *po;
2132         struct sockaddr_ll *sll;
2133         union tpacket_uhdr h;
2134         u8 *skb_head = skb->data;
2135         int skb_len = skb->len;
2136         unsigned int snaplen, res;
2137         unsigned long status = TP_STATUS_USER;
2138         unsigned short macoff, netoff, hdrlen;
2139         struct sk_buff *copy_skb = NULL;
2140         struct timespec ts;
2141         __u32 ts_status;
2142         bool is_drop_n_account = false;
2143
2144         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2145          * We may add members to them until current aligned size without forcing
2146          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2147          */
2148         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2149         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2150
2151         if (skb->pkt_type == PACKET_LOOPBACK)
2152                 goto drop;
2153
2154         sk = pt->af_packet_priv;
2155         po = pkt_sk(sk);
2156
2157         if (!net_eq(dev_net(dev), sock_net(sk)))
2158                 goto drop;
2159
2160         if (dev->header_ops) {
2161                 if (sk->sk_type != SOCK_DGRAM)
2162                         skb_push(skb, skb->data - skb_mac_header(skb));
2163                 else if (skb->pkt_type == PACKET_OUTGOING) {
2164                         /* Special case: outgoing packets have ll header at head */
2165                         skb_pull(skb, skb_network_offset(skb));
2166                 }
2167         }
2168
2169         snaplen = skb->len;
2170
2171         res = run_filter(skb, sk, snaplen);
2172         if (!res)
2173                 goto drop_n_restore;
2174
2175         if (skb->ip_summed == CHECKSUM_PARTIAL)
2176                 status |= TP_STATUS_CSUMNOTREADY;
2177         else if (skb->pkt_type != PACKET_OUTGOING &&
2178                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2179                   skb_csum_unnecessary(skb)))
2180                 status |= TP_STATUS_CSUM_VALID;
2181
2182         if (snaplen > res)
2183                 snaplen = res;
2184
2185         if (sk->sk_type == SOCK_DGRAM) {
2186                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2187                                   po->tp_reserve;
2188         } else {
2189                 unsigned int maclen = skb_network_offset(skb);
2190                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2191                                        (maclen < 16 ? 16 : maclen)) +
2192                                        po->tp_reserve;
2193                 if (po->has_vnet_hdr)
2194                         netoff += sizeof(struct virtio_net_hdr);
2195                 macoff = netoff - maclen;
2196         }
2197         if (po->tp_version <= TPACKET_V2) {
2198                 if (macoff + snaplen > po->rx_ring.frame_size) {
2199                         if (po->copy_thresh &&
2200                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2201                                 if (skb_shared(skb)) {
2202                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2203                                 } else {
2204                                         copy_skb = skb_get(skb);
2205                                         skb_head = skb->data;
2206                                 }
2207                                 if (copy_skb)
2208                                         skb_set_owner_r(copy_skb, sk);
2209                         }
2210                         snaplen = po->rx_ring.frame_size - macoff;
2211                         if ((int)snaplen < 0)
2212                                 snaplen = 0;
2213                 }
2214         } else if (unlikely(macoff + snaplen >
2215                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2216                 u32 nval;
2217
2218                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2219                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2220                             snaplen, nval, macoff);
2221                 snaplen = nval;
2222                 if (unlikely((int)snaplen < 0)) {
2223                         snaplen = 0;
2224                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2225                 }
2226         }
2227         spin_lock(&sk->sk_receive_queue.lock);
2228         h.raw = packet_current_rx_frame(po, skb,
2229                                         TP_STATUS_KERNEL, (macoff+snaplen));
2230         if (!h.raw)
2231                 goto drop_n_account;
2232         if (po->tp_version <= TPACKET_V2) {
2233                 packet_increment_rx_head(po, &po->rx_ring);
2234         /*
2235          * LOSING will be reported till you read the stats,
2236          * because it's COR - Clear On Read.
2237          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2238          * at packet level.
2239          */
2240                 if (po->stats.stats1.tp_drops)
2241                         status |= TP_STATUS_LOSING;
2242         }
2243         po->stats.stats1.tp_packets++;
2244         if (copy_skb) {
2245                 status |= TP_STATUS_COPY;
2246                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2247         }
2248         spin_unlock(&sk->sk_receive_queue.lock);
2249
2250         if (po->has_vnet_hdr) {
2251                 if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
2252                                             sizeof(struct virtio_net_hdr),
2253                                             vio_le(), true)) {
2254                         spin_lock(&sk->sk_receive_queue.lock);
2255                         goto drop_n_account;
2256                 }
2257         }
2258
2259         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2260
2261         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2262                 getnstimeofday(&ts);
2263
2264         status |= ts_status;
2265
2266         switch (po->tp_version) {
2267         case TPACKET_V1:
2268                 h.h1->tp_len = skb->len;
2269                 h.h1->tp_snaplen = snaplen;
2270                 h.h1->tp_mac = macoff;
2271                 h.h1->tp_net = netoff;
2272                 h.h1->tp_sec = ts.tv_sec;
2273                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2274                 hdrlen = sizeof(*h.h1);
2275                 break;
2276         case TPACKET_V2:
2277                 h.h2->tp_len = skb->len;
2278                 h.h2->tp_snaplen = snaplen;
2279                 h.h2->tp_mac = macoff;
2280                 h.h2->tp_net = netoff;
2281                 h.h2->tp_sec = ts.tv_sec;
2282                 h.h2->tp_nsec = ts.tv_nsec;
2283                 if (skb_vlan_tag_present(skb)) {
2284                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2285                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2286                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2287                 } else {
2288                         h.h2->tp_vlan_tci = 0;
2289                         h.h2->tp_vlan_tpid = 0;
2290                 }
2291                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2292                 hdrlen = sizeof(*h.h2);
2293                 break;
2294         case TPACKET_V3:
2295                 /* tp_nxt_offset,vlan are already populated above.
2296                  * So DONT clear those fields here
2297                  */
2298                 h.h3->tp_status |= status;
2299                 h.h3->tp_len = skb->len;
2300                 h.h3->tp_snaplen = snaplen;
2301                 h.h3->tp_mac = macoff;
2302                 h.h3->tp_net = netoff;
2303                 h.h3->tp_sec  = ts.tv_sec;
2304                 h.h3->tp_nsec = ts.tv_nsec;
2305                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2306                 hdrlen = sizeof(*h.h3);
2307                 break;
2308         default:
2309                 BUG();
2310         }
2311
2312         sll = h.raw + TPACKET_ALIGN(hdrlen);
2313         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2314         sll->sll_family = AF_PACKET;
2315         sll->sll_hatype = dev->type;
2316         sll->sll_protocol = skb->protocol;
2317         sll->sll_pkttype = skb->pkt_type;
2318         if (unlikely(po->origdev))
2319                 sll->sll_ifindex = orig_dev->ifindex;
2320         else
2321                 sll->sll_ifindex = dev->ifindex;
2322
2323         smp_mb();
2324
2325 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2326         if (po->tp_version <= TPACKET_V2) {
2327                 u8 *start, *end;
2328
2329                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2330                                         macoff + snaplen);
2331
2332                 for (start = h.raw; start < end; start += PAGE_SIZE)
2333                         flush_dcache_page(pgv_to_page(start));
2334         }
2335         smp_wmb();
2336 #endif
2337
2338         if (po->tp_version <= TPACKET_V2) {
2339                 __packet_set_status(po, h.raw, status);
2340                 sk->sk_data_ready(sk);
2341         } else {
2342                 prb_clear_blk_fill_status(&po->rx_ring);
2343         }
2344
2345 drop_n_restore:
2346         if (skb_head != skb->data && skb_shared(skb)) {
2347                 skb->data = skb_head;
2348                 skb->len = skb_len;
2349         }
2350 drop:
2351         if (!is_drop_n_account)
2352                 consume_skb(skb);
2353         else
2354                 kfree_skb(skb);
2355         return 0;
2356
2357 drop_n_account:
2358         is_drop_n_account = true;
2359         po->stats.stats1.tp_drops++;
2360         spin_unlock(&sk->sk_receive_queue.lock);
2361
2362         sk->sk_data_ready(sk);
2363         kfree_skb(copy_skb);
2364         goto drop_n_restore;
2365 }
2366
2367 static void tpacket_destruct_skb(struct sk_buff *skb)
2368 {
2369         struct packet_sock *po = pkt_sk(skb->sk);
2370
2371         if (likely(po->tx_ring.pg_vec)) {
2372                 void *ph;
2373                 __u32 ts;
2374
2375                 ph = skb_shinfo(skb)->destructor_arg;
2376                 packet_dec_pending(&po->tx_ring);
2377
2378                 ts = __packet_set_timestamp(po, ph, skb);
2379                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2380         }
2381
2382         sock_wfree(skb);
2383 }
2384
2385 static void tpacket_set_protocol(const struct net_device *dev,
2386                                  struct sk_buff *skb)
2387 {
2388         if (dev->type == ARPHRD_ETHER) {
2389                 skb_reset_mac_header(skb);
2390                 skb->protocol = eth_hdr(skb)->h_proto;
2391         }
2392 }
2393
2394 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2395 {
2396         if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2397             (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2398              __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2399               __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2400                 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2401                          __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2402                         __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2403
2404         if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2405                 return -EINVAL;
2406
2407         return 0;
2408 }
2409
2410 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2411                                  struct virtio_net_hdr *vnet_hdr)
2412 {
2413         if (*len < sizeof(*vnet_hdr))
2414                 return -EINVAL;
2415         *len -= sizeof(*vnet_hdr);
2416
2417         if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2418                 return -EFAULT;
2419
2420         return __packet_snd_vnet_parse(vnet_hdr, *len);
2421 }
2422
2423 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2424                 void *frame, struct net_device *dev, void *data, int tp_len,
2425                 __be16 proto, unsigned char *addr, int hlen, int copylen,
2426                 const struct sockcm_cookie *sockc)
2427 {
2428         union tpacket_uhdr ph;
2429         int to_write, offset, len, nr_frags, len_max;
2430         struct socket *sock = po->sk.sk_socket;
2431         struct page *page;
2432         int err;
2433
2434         ph.raw = frame;
2435
2436         skb->protocol = proto;
2437         skb->dev = dev;
2438         skb->priority = po->sk.sk_priority;
2439         skb->mark = po->sk.sk_mark;
2440         sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);
2441         skb_shinfo(skb)->destructor_arg = ph.raw;
2442
2443         skb_reserve(skb, hlen);
2444         skb_reset_network_header(skb);
2445
2446         to_write = tp_len;
2447
2448         if (sock->type == SOCK_DGRAM) {
2449                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2450                                 NULL, tp_len);
2451                 if (unlikely(err < 0))
2452                         return -EINVAL;
2453         } else if (copylen) {
2454                 int hdrlen = min_t(int, copylen, tp_len);
2455
2456                 skb_push(skb, dev->hard_header_len);
2457                 skb_put(skb, copylen - dev->hard_header_len);
2458                 err = skb_store_bits(skb, 0, data, hdrlen);
2459                 if (unlikely(err))
2460                         return err;
2461                 if (!dev_validate_header(dev, skb->data, hdrlen))
2462                         return -EINVAL;
2463                 if (!skb->protocol)
2464                         tpacket_set_protocol(dev, skb);
2465
2466                 data += hdrlen;
2467                 to_write -= hdrlen;
2468         }
2469
2470         offset = offset_in_page(data);
2471         len_max = PAGE_SIZE - offset;
2472         len = ((to_write > len_max) ? len_max : to_write);
2473
2474         skb->data_len = to_write;
2475         skb->len += to_write;
2476         skb->truesize += to_write;
2477         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2478
2479         while (likely(to_write)) {
2480                 nr_frags = skb_shinfo(skb)->nr_frags;
2481
2482                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2483                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2484                                MAX_SKB_FRAGS);
2485                         return -EFAULT;
2486                 }
2487
2488                 page = pgv_to_page(data);
2489                 data += len;
2490                 flush_dcache_page(page);
2491                 get_page(page);
2492                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2493                 to_write -= len;
2494                 offset = 0;
2495                 len_max = PAGE_SIZE;
2496                 len = ((to_write > len_max) ? len_max : to_write);
2497         }
2498
2499         skb_probe_transport_header(skb, 0);
2500
2501         return tp_len;
2502 }
2503
2504 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2505                                 int size_max, void **data)
2506 {
2507         union tpacket_uhdr ph;
2508         int tp_len, off;
2509
2510         ph.raw = frame;
2511
2512         switch (po->tp_version) {
2513         case TPACKET_V2:
2514                 tp_len = ph.h2->tp_len;
2515                 break;
2516         default:
2517                 tp_len = ph.h1->tp_len;
2518                 break;
2519         }
2520         if (unlikely(tp_len > size_max)) {
2521                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2522                 return -EMSGSIZE;
2523         }
2524
2525         if (unlikely(po->tp_tx_has_off)) {
2526                 int off_min, off_max;
2527
2528                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2529                 off_max = po->tx_ring.frame_size - tp_len;
2530                 if (po->sk.sk_type == SOCK_DGRAM) {
2531                         switch (po->tp_version) {
2532                         case TPACKET_V2:
2533                                 off = ph.h2->tp_net;
2534                                 break;
2535                         default:
2536                                 off = ph.h1->tp_net;
2537                                 break;
2538                         }
2539                 } else {
2540                         switch (po->tp_version) {
2541                         case TPACKET_V2:
2542                                 off = ph.h2->tp_mac;
2543                                 break;
2544                         default:
2545                                 off = ph.h1->tp_mac;
2546                                 break;
2547                         }
2548                 }
2549                 if (unlikely((off < off_min) || (off_max < off)))
2550                         return -EINVAL;
2551         } else {
2552                 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2553         }
2554
2555         *data = frame + off;
2556         return tp_len;
2557 }
2558
2559 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2560 {
2561         struct sk_buff *skb;
2562         struct net_device *dev;
2563         struct virtio_net_hdr *vnet_hdr = NULL;
2564         struct sockcm_cookie sockc;
2565         __be16 proto;
2566         int err, reserve = 0;
2567         void *ph;
2568         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2569         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2570         int tp_len, size_max;
2571         unsigned char *addr;
2572         void *data;
2573         int len_sum = 0;
2574         int status = TP_STATUS_AVAILABLE;
2575         int hlen, tlen, copylen = 0;
2576
2577         mutex_lock(&po->pg_vec_lock);
2578
2579         if (likely(saddr == NULL)) {
2580                 dev     = packet_cached_dev_get(po);
2581                 proto   = po->num;
2582                 addr    = NULL;
2583         } else {
2584                 err = -EINVAL;
2585                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2586                         goto out;
2587                 if (msg->msg_namelen < (saddr->sll_halen
2588                                         + offsetof(struct sockaddr_ll,
2589                                                 sll_addr)))
2590                         goto out;
2591                 proto   = saddr->sll_protocol;
2592                 addr    = saddr->sll_addr;
2593                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2594         }
2595
2596         sockc.tsflags = po->sk.sk_tsflags;
2597         if (msg->msg_controllen) {
2598                 err = sock_cmsg_send(&po->sk, msg, &sockc);
2599                 if (unlikely(err))
2600                         goto out;
2601         }
2602
2603         err = -ENXIO;
2604         if (unlikely(dev == NULL))
2605                 goto out;
2606         err = -ENETDOWN;
2607         if (unlikely(!(dev->flags & IFF_UP)))
2608                 goto out_put;
2609
2610         if (po->sk.sk_socket->type == SOCK_RAW)
2611                 reserve = dev->hard_header_len;
2612         size_max = po->tx_ring.frame_size
2613                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2614
2615         if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2616                 size_max = dev->mtu + reserve + VLAN_HLEN;
2617
2618         do {
2619                 ph = packet_current_frame(po, &po->tx_ring,
2620                                           TP_STATUS_SEND_REQUEST);
2621                 if (unlikely(ph == NULL)) {
2622                         if (need_wait && need_resched())
2623                                 schedule();
2624                         continue;
2625                 }
2626
2627                 skb = NULL;
2628                 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2629                 if (tp_len < 0)
2630                         goto tpacket_error;
2631
2632                 status = TP_STATUS_SEND_REQUEST;
2633                 hlen = LL_RESERVED_SPACE(dev);
2634                 tlen = dev->needed_tailroom;
2635                 if (po->has_vnet_hdr) {
2636                         vnet_hdr = data;
2637                         data += sizeof(*vnet_hdr);
2638                         tp_len -= sizeof(*vnet_hdr);
2639                         if (tp_len < 0 ||
2640                             __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2641                                 tp_len = -EINVAL;
2642                                 goto tpacket_error;
2643                         }
2644                         copylen = __virtio16_to_cpu(vio_le(),
2645                                                     vnet_hdr->hdr_len);
2646                 }
2647                 copylen = max_t(int, copylen, dev->hard_header_len);
2648                 skb = sock_alloc_send_skb(&po->sk,
2649                                 hlen + tlen + sizeof(struct sockaddr_ll) +
2650                                 (copylen - dev->hard_header_len),
2651                                 !need_wait, &err);
2652
2653                 if (unlikely(skb == NULL)) {
2654                         /* we assume the socket was initially writeable ... */
2655                         if (likely(len_sum > 0))
2656                                 err = len_sum;
2657                         goto out_status;
2658                 }
2659                 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2660                                           addr, hlen, copylen, &sockc);
2661                 if (likely(tp_len >= 0) &&
2662                     tp_len > dev->mtu + reserve &&
2663                     !po->has_vnet_hdr &&
2664                     !packet_extra_vlan_len_allowed(dev, skb))
2665                         tp_len = -EMSGSIZE;
2666
2667                 if (unlikely(tp_len < 0)) {
2668 tpacket_error:
2669                         if (po->tp_loss) {
2670                                 __packet_set_status(po, ph,
2671                                                 TP_STATUS_AVAILABLE);
2672                                 packet_increment_head(&po->tx_ring);
2673                                 kfree_skb(skb);
2674                                 continue;
2675                         } else {
2676                                 status = TP_STATUS_WRONG_FORMAT;
2677                                 err = tp_len;
2678                                 goto out_status;
2679                         }
2680                 }
2681
2682                 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
2683                                                               vio_le())) {
2684                         tp_len = -EINVAL;
2685                         goto tpacket_error;
2686                 }
2687
2688                 packet_pick_tx_queue(dev, skb);
2689
2690                 skb->destructor = tpacket_destruct_skb;
2691                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2692                 packet_inc_pending(&po->tx_ring);
2693
2694                 status = TP_STATUS_SEND_REQUEST;
2695                 err = po->xmit(skb);
2696                 if (unlikely(err > 0)) {
2697                         err = net_xmit_errno(err);
2698                         if (err && __packet_get_status(po, ph) ==
2699                                    TP_STATUS_AVAILABLE) {
2700                                 /* skb was destructed already */
2701                                 skb = NULL;
2702                                 goto out_status;
2703                         }
2704                         /*
2705                          * skb was dropped but not destructed yet;
2706                          * let's treat it like congestion or err < 0
2707                          */
2708                         err = 0;
2709                 }
2710                 packet_increment_head(&po->tx_ring);
2711                 len_sum += tp_len;
2712         } while (likely((ph != NULL) ||
2713                 /* Note: packet_read_pending() might be slow if we have
2714                  * to call it as it's per_cpu variable, but in fast-path
2715                  * we already short-circuit the loop with the first
2716                  * condition, and luckily don't have to go that path
2717                  * anyway.
2718                  */
2719                  (need_wait && packet_read_pending(&po->tx_ring))));
2720
2721         err = len_sum;
2722         goto out_put;
2723
2724 out_status:
2725         __packet_set_status(po, ph, status);
2726         kfree_skb(skb);
2727 out_put:
2728         dev_put(dev);
2729 out:
2730         mutex_unlock(&po->pg_vec_lock);
2731         return err;
2732 }
2733
2734 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2735                                         size_t reserve, size_t len,
2736                                         size_t linear, int noblock,
2737                                         int *err)
2738 {
2739         struct sk_buff *skb;
2740
2741         /* Under a page?  Don't bother with paged skb. */
2742         if (prepad + len < PAGE_SIZE || !linear)
2743                 linear = len;
2744
2745         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2746                                    err, 0);
2747         if (!skb)
2748                 return NULL;
2749
2750         skb_reserve(skb, reserve);
2751         skb_put(skb, linear);
2752         skb->data_len = len - linear;
2753         skb->len += len - linear;
2754
2755         return skb;
2756 }
2757
2758 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2759 {
2760         struct sock *sk = sock->sk;
2761         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2762         struct sk_buff *skb;
2763         struct net_device *dev;
2764         __be16 proto;
2765         unsigned char *addr;
2766         int err, reserve = 0;
2767         struct sockcm_cookie sockc;
2768         struct virtio_net_hdr vnet_hdr = { 0 };
2769         int offset = 0;
2770         struct packet_sock *po = pkt_sk(sk);
2771         int hlen, tlen, linear;
2772         int extra_len = 0;
2773
2774         /*
2775          *      Get and verify the address.
2776          */
2777
2778         if (likely(saddr == NULL)) {
2779                 dev     = packet_cached_dev_get(po);
2780                 proto   = po->num;
2781                 addr    = NULL;
2782         } else {
2783                 err = -EINVAL;
2784                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2785                         goto out;
2786                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2787                         goto out;
2788                 proto   = saddr->sll_protocol;
2789                 addr    = saddr->sll_addr;
2790                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2791         }
2792
2793         err = -ENXIO;
2794         if (unlikely(dev == NULL))
2795                 goto out_unlock;
2796         err = -ENETDOWN;
2797         if (unlikely(!(dev->flags & IFF_UP)))
2798                 goto out_unlock;
2799
2800         sockc.tsflags = sk->sk_tsflags;
2801         sockc.mark = sk->sk_mark;
2802         if (msg->msg_controllen) {
2803                 err = sock_cmsg_send(sk, msg, &sockc);
2804                 if (unlikely(err))
2805                         goto out_unlock;
2806         }
2807
2808         if (sock->type == SOCK_RAW)
2809                 reserve = dev->hard_header_len;
2810         if (po->has_vnet_hdr) {
2811                 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2812                 if (err)
2813                         goto out_unlock;
2814         }
2815
2816         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2817                 if (!netif_supports_nofcs(dev)) {
2818                         err = -EPROTONOSUPPORT;
2819                         goto out_unlock;
2820                 }
2821                 extra_len = 4; /* We're doing our own CRC */
2822         }
2823
2824         err = -EMSGSIZE;
2825         if (!vnet_hdr.gso_type &&
2826             (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2827                 goto out_unlock;
2828
2829         err = -ENOBUFS;
2830         hlen = LL_RESERVED_SPACE(dev);
2831         tlen = dev->needed_tailroom;
2832         linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2833         linear = max(linear, min_t(int, len, dev->hard_header_len));
2834         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2835                                msg->msg_flags & MSG_DONTWAIT, &err);
2836         if (skb == NULL)
2837                 goto out_unlock;
2838
2839         skb_set_network_header(skb, reserve);
2840
2841         err = -EINVAL;
2842         if (sock->type == SOCK_DGRAM) {
2843                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2844                 if (unlikely(offset < 0))
2845                         goto out_free;
2846         }
2847
2848         /* Returns -EFAULT on error */
2849         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2850         if (err)
2851                 goto out_free;
2852
2853         if (sock->type == SOCK_RAW &&
2854             !dev_validate_header(dev, skb->data, len)) {
2855                 err = -EINVAL;
2856                 goto out_free;
2857         }
2858
2859         sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
2860
2861         if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2862             !packet_extra_vlan_len_allowed(dev, skb)) {
2863                 err = -EMSGSIZE;
2864                 goto out_free;
2865         }
2866
2867         skb->protocol = proto;
2868         skb->dev = dev;
2869         skb->priority = sk->sk_priority;
2870         skb->mark = sockc.mark;
2871
2872         packet_pick_tx_queue(dev, skb);
2873
2874         if (po->has_vnet_hdr) {
2875                 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2876                 if (err)
2877                         goto out_free;
2878                 len += sizeof(vnet_hdr);
2879         }
2880
2881         skb_probe_transport_header(skb, reserve);
2882
2883         if (unlikely(extra_len == 4))
2884                 skb->no_fcs = 1;
2885
2886         err = po->xmit(skb);
2887         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2888                 goto out_unlock;
2889
2890         dev_put(dev);
2891
2892         return len;
2893
2894 out_free:
2895         kfree_skb(skb);
2896 out_unlock:
2897         if (dev)
2898                 dev_put(dev);
2899 out:
2900         return err;
2901 }
2902
2903 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2904 {
2905         struct sock *sk = sock->sk;
2906         struct packet_sock *po = pkt_sk(sk);
2907
2908         if (po->tx_ring.pg_vec)
2909                 return tpacket_snd(po, msg);
2910         else
2911                 return packet_snd(sock, msg, len);
2912 }
2913
2914 /*
2915  *      Close a PACKET socket. This is fairly simple. We immediately go
2916  *      to 'closed' state and remove our protocol entry in the device list.
2917  */
2918
2919 static int packet_release(struct socket *sock)
2920 {
2921         struct sock *sk = sock->sk;
2922         struct packet_sock *po;
2923         struct packet_fanout *f;
2924         struct net *net;
2925         union tpacket_req_u req_u;
2926
2927         if (!sk)
2928                 return 0;
2929
2930         net = sock_net(sk);
2931         po = pkt_sk(sk);
2932
2933         mutex_lock(&net->packet.sklist_lock);
2934         sk_del_node_init_rcu(sk);
2935         mutex_unlock(&net->packet.sklist_lock);
2936
2937         preempt_disable();
2938         sock_prot_inuse_add(net, sk->sk_prot, -1);
2939         preempt_enable();
2940
2941         spin_lock(&po->bind_lock);
2942         unregister_prot_hook(sk, false);
2943         packet_cached_dev_reset(po);
2944
2945         if (po->prot_hook.dev) {
2946                 dev_put(po->prot_hook.dev);
2947                 po->prot_hook.dev = NULL;
2948         }
2949         spin_unlock(&po->bind_lock);
2950
2951         packet_flush_mclist(sk);
2952
2953         if (po->rx_ring.pg_vec) {
2954                 memset(&req_u, 0, sizeof(req_u));
2955                 packet_set_ring(sk, &req_u, 1, 0);
2956         }
2957
2958         if (po->tx_ring.pg_vec) {
2959                 memset(&req_u, 0, sizeof(req_u));
2960                 packet_set_ring(sk, &req_u, 1, 1);
2961         }
2962
2963         f = fanout_release(sk);
2964
2965         synchronize_net();
2966
2967         if (f) {
2968                 fanout_release_data(f);
2969                 kfree(f);
2970         }
2971         /*
2972          *      Now the socket is dead. No more input will appear.
2973          */
2974         sock_orphan(sk);
2975         sock->sk = NULL;
2976
2977         /* Purge queues */
2978
2979         skb_queue_purge(&sk->sk_receive_queue);
2980         packet_free_pending(po);
2981         sk_refcnt_debug_release(sk);
2982
2983         sock_put(sk);
2984         return 0;
2985 }
2986
2987 /*
2988  *      Attach a packet hook.
2989  */
2990
2991 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2992                           __be16 proto)
2993 {
2994         struct packet_sock *po = pkt_sk(sk);
2995         struct net_device *dev_curr;
2996         __be16 proto_curr;
2997         bool need_rehook;
2998         struct net_device *dev = NULL;
2999         int ret = 0;
3000         bool unlisted = false;
3001
3002         if (po->fanout)
3003                 return -EINVAL;
3004
3005         lock_sock(sk);
3006         spin_lock(&po->bind_lock);
3007         rcu_read_lock();
3008
3009         if (name) {
3010                 dev = dev_get_by_name_rcu(sock_net(sk), name);
3011                 if (!dev) {
3012                         ret = -ENODEV;
3013                         goto out_unlock;
3014                 }
3015         } else if (ifindex) {
3016                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3017                 if (!dev) {
3018                         ret = -ENODEV;
3019                         goto out_unlock;
3020                 }
3021         }
3022
3023         if (dev)
3024                 dev_hold(dev);
3025
3026         proto_curr = po->prot_hook.type;
3027         dev_curr = po->prot_hook.dev;
3028
3029         need_rehook = proto_curr != proto || dev_curr != dev;
3030
3031         if (need_rehook) {
3032                 if (po->running) {
3033                         rcu_read_unlock();
3034                         __unregister_prot_hook(sk, true);
3035                         rcu_read_lock();
3036                         dev_curr = po->prot_hook.dev;
3037                         if (dev)
3038                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3039                                                                  dev->ifindex);
3040                 }
3041
3042                 po->num = proto;
3043                 po->prot_hook.type = proto;
3044
3045                 if (unlikely(unlisted)) {
3046                         dev_put(dev);
3047                         po->prot_hook.dev = NULL;
3048                         po->ifindex = -1;
3049                         packet_cached_dev_reset(po);
3050                 } else {
3051                         po->prot_hook.dev = dev;
3052                         po->ifindex = dev ? dev->ifindex : 0;
3053                         packet_cached_dev_assign(po, dev);
3054                 }
3055         }
3056         if (dev_curr)
3057                 dev_put(dev_curr);
3058
3059         if (proto == 0 || !need_rehook)
3060                 goto out_unlock;
3061
3062         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3063                 register_prot_hook(sk);
3064         } else {
3065                 sk->sk_err = ENETDOWN;
3066                 if (!sock_flag(sk, SOCK_DEAD))
3067                         sk->sk_error_report(sk);
3068         }
3069
3070 out_unlock:
3071         rcu_read_unlock();
3072         spin_unlock(&po->bind_lock);
3073         release_sock(sk);
3074         return ret;
3075 }
3076
3077 /*
3078  *      Bind a packet socket to a device
3079  */
3080
3081 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3082                             int addr_len)
3083 {
3084         struct sock *sk = sock->sk;
3085         char name[15];
3086
3087         /*
3088          *      Check legality
3089          */
3090
3091         if (addr_len != sizeof(struct sockaddr))
3092                 return -EINVAL;
3093         strlcpy(name, uaddr->sa_data, sizeof(name));
3094
3095         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3096 }
3097
3098 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3099 {
3100         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3101         struct sock *sk = sock->sk;
3102
3103         /*
3104          *      Check legality
3105          */
3106
3107         if (addr_len < sizeof(struct sockaddr_ll))
3108                 return -EINVAL;
3109         if (sll->sll_family != AF_PACKET)
3110                 return -EINVAL;
3111
3112         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3113                               sll->sll_protocol ? : pkt_sk(sk)->num);
3114 }
3115
3116 static struct proto packet_proto = {
3117         .name     = "PACKET",
3118         .owner    = THIS_MODULE,
3119         .obj_size = sizeof(struct packet_sock),
3120 };
3121
3122 /*
3123  *      Create a packet of type SOCK_PACKET.
3124  */
3125
3126 static int packet_create(struct net *net, struct socket *sock, int protocol,
3127                          int kern)
3128 {
3129         struct sock *sk;
3130         struct packet_sock *po;
3131         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3132         int err;
3133
3134         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3135                 return -EPERM;
3136         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3137             sock->type != SOCK_PACKET)
3138                 return -ESOCKTNOSUPPORT;
3139
3140         sock->state = SS_UNCONNECTED;
3141
3142         err = -ENOBUFS;
3143         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3144         if (sk == NULL)
3145                 goto out;
3146
3147         sock->ops = &packet_ops;
3148         if (sock->type == SOCK_PACKET)
3149                 sock->ops = &packet_ops_spkt;
3150
3151         sock_init_data(sock, sk);
3152
3153         po = pkt_sk(sk);
3154         sk->sk_family = PF_PACKET;
3155         po->num = proto;
3156         po->xmit = dev_queue_xmit;
3157
3158         err = packet_alloc_pending(po);
3159         if (err)
3160                 goto out2;
3161
3162         packet_cached_dev_reset(po);
3163
3164         sk->sk_destruct = packet_sock_destruct;
3165         sk_refcnt_debug_inc(sk);
3166
3167         /*
3168          *      Attach a protocol block
3169          */
3170
3171         spin_lock_init(&po->bind_lock);
3172         mutex_init(&po->pg_vec_lock);
3173         po->rollover = NULL;
3174         po->prot_hook.func = packet_rcv;
3175
3176         if (sock->type == SOCK_PACKET)
3177                 po->prot_hook.func = packet_rcv_spkt;
3178
3179         po->prot_hook.af_packet_priv = sk;
3180
3181         if (proto) {
3182                 po->prot_hook.type = proto;
3183                 register_prot_hook(sk);
3184         }
3185
3186         mutex_lock(&net->packet.sklist_lock);
3187         sk_add_node_rcu(sk, &net->packet.sklist);
3188         mutex_unlock(&net->packet.sklist_lock);
3189
3190         preempt_disable();
3191         sock_prot_inuse_add(net, &packet_proto, 1);
3192         preempt_enable();
3193
3194         return 0;
3195 out2:
3196         sk_free(sk);
3197 out:
3198         return err;
3199 }
3200
3201 /*
3202  *      Pull a packet from our receive queue and hand it to the user.
3203  *      If necessary we block.
3204  */
3205
3206 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3207                           int flags)
3208 {
3209         struct sock *sk = sock->sk;
3210         struct sk_buff *skb;
3211         int copied, err;
3212         int vnet_hdr_len = 0;
3213         unsigned int origlen = 0;
3214
3215         err = -EINVAL;
3216         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3217                 goto out;
3218
3219 #if 0
3220         /* What error should we return now? EUNATTACH? */
3221         if (pkt_sk(sk)->ifindex < 0)
3222                 return -ENODEV;
3223 #endif
3224
3225         if (flags & MSG_ERRQUEUE) {
3226                 err = sock_recv_errqueue(sk, msg, len,
3227                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3228                 goto out;
3229         }
3230
3231         /*
3232          *      Call the generic datagram receiver. This handles all sorts
3233          *      of horrible races and re-entrancy so we can forget about it
3234          *      in the protocol layers.
3235          *
3236          *      Now it will return ENETDOWN, if device have just gone down,
3237          *      but then it will block.
3238          */
3239
3240         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3241
3242         /*
3243          *      An error occurred so return it. Because skb_recv_datagram()
3244          *      handles the blocking we don't see and worry about blocking
3245          *      retries.
3246          */
3247
3248         if (skb == NULL)
3249                 goto out;
3250
3251         if (pkt_sk(sk)->pressure)
3252                 packet_rcv_has_room(pkt_sk(sk), NULL);
3253
3254         if (pkt_sk(sk)->has_vnet_hdr) {
3255                 err = packet_rcv_vnet(msg, skb, &len);
3256                 if (err)
3257                         goto out_free;
3258                 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3259         }
3260
3261         /* You lose any data beyond the buffer you gave. If it worries
3262          * a user program they can ask the device for its MTU
3263          * anyway.
3264          */
3265         copied = skb->len;
3266         if (copied > len) {
3267                 copied = len;
3268                 msg->msg_flags |= MSG_TRUNC;
3269         }
3270
3271         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3272         if (err)
3273                 goto out_free;
3274
3275         if (sock->type != SOCK_PACKET) {
3276                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3277
3278                 /* Original length was stored in sockaddr_ll fields */
3279                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3280                 sll->sll_family = AF_PACKET;
3281                 sll->sll_protocol = skb->protocol;
3282         }
3283
3284         sock_recv_ts_and_drops(msg, sk, skb);
3285
3286         if (msg->msg_name) {
3287                 /* If the address length field is there to be filled
3288                  * in, we fill it in now.
3289                  */
3290                 if (sock->type == SOCK_PACKET) {
3291                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3292                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3293                 } else {
3294                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3295
3296                         msg->msg_namelen = sll->sll_halen +
3297                                 offsetof(struct sockaddr_ll, sll_addr);
3298                 }
3299                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3300                        msg->msg_namelen);
3301         }
3302
3303         if (pkt_sk(sk)->auxdata) {
3304                 struct tpacket_auxdata aux;
3305
3306                 aux.tp_status = TP_STATUS_USER;
3307                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3308                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3309                 else if (skb->pkt_type != PACKET_OUTGOING &&
3310                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3311                           skb_csum_unnecessary(skb)))
3312                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3313
3314                 aux.tp_len = origlen;
3315                 aux.tp_snaplen = skb->len;
3316                 aux.tp_mac = 0;
3317                 aux.tp_net = skb_network_offset(skb);
3318                 if (skb_vlan_tag_present(skb)) {
3319                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3320                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3321                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3322                 } else {
3323                         aux.tp_vlan_tci = 0;
3324                         aux.tp_vlan_tpid = 0;
3325                 }
3326                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3327         }
3328
3329         /*
3330          *      Free or return the buffer as appropriate. Again this
3331          *      hides all the races and re-entrancy issues from us.
3332          */
3333         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3334
3335 out_free:
3336         skb_free_datagram(sk, skb);
3337 out:
3338         return err;
3339 }
3340
3341 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3342                                int *uaddr_len, int peer)
3343 {
3344         struct net_device *dev;
3345         struct sock *sk = sock->sk;
3346
3347         if (peer)
3348                 return -EOPNOTSUPP;
3349
3350         uaddr->sa_family = AF_PACKET;
3351         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3352         rcu_read_lock();
3353         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3354         if (dev)
3355                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3356         rcu_read_unlock();
3357         *uaddr_len = sizeof(*uaddr);
3358
3359         return 0;
3360 }
3361
3362 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3363                           int *uaddr_len, int peer)
3364 {
3365         struct net_device *dev;
3366         struct sock *sk = sock->sk;
3367         struct packet_sock *po = pkt_sk(sk);
3368         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3369
3370         if (peer)
3371                 return -EOPNOTSUPP;
3372
3373         sll->sll_family = AF_PACKET;
3374         sll->sll_ifindex = po->ifindex;
3375         sll->sll_protocol = po->num;
3376         sll->sll_pkttype = 0;
3377         rcu_read_lock();
3378         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3379         if (dev) {
3380                 sll->sll_hatype = dev->type;
3381                 sll->sll_halen = dev->addr_len;
3382                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3383         } else {
3384                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3385                 sll->sll_halen = 0;
3386         }
3387         rcu_read_unlock();
3388         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3389
3390         return 0;
3391 }
3392
3393 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3394                          int what)
3395 {
3396         switch (i->type) {
3397         case PACKET_MR_MULTICAST:
3398                 if (i->alen != dev->addr_len)
3399                         return -EINVAL;
3400                 if (what > 0)
3401                         return dev_mc_add(dev, i->addr);
3402                 else
3403                         return dev_mc_del(dev, i->addr);
3404                 break;
3405         case PACKET_MR_PROMISC:
3406                 return dev_set_promiscuity(dev, what);
3407         case PACKET_MR_ALLMULTI:
3408                 return dev_set_allmulti(dev, what);
3409         case PACKET_MR_UNICAST:
3410                 if (i->alen != dev->addr_len)
3411                         return -EINVAL;
3412                 if (what > 0)
3413                         return dev_uc_add(dev, i->addr);
3414                 else
3415                         return dev_uc_del(dev, i->addr);
3416                 break;
3417         default:
3418                 break;
3419         }
3420         return 0;
3421 }
3422
3423 static void packet_dev_mclist_delete(struct net_device *dev,
3424                                      struct packet_mclist **mlp)
3425 {
3426         struct packet_mclist *ml;
3427
3428         while ((ml = *mlp) != NULL) {
3429                 if (ml->ifindex == dev->ifindex) {
3430                         packet_dev_mc(dev, ml, -1);
3431                         *mlp = ml->next;
3432                         kfree(ml);
3433                 } else
3434                         mlp = &ml->next;
3435         }
3436 }
3437
3438 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3439 {
3440         struct packet_sock *po = pkt_sk(sk);
3441         struct packet_mclist *ml, *i;
3442         struct net_device *dev;
3443         int err;
3444
3445         rtnl_lock();
3446
3447         err = -ENODEV;
3448         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3449         if (!dev)
3450                 goto done;
3451
3452         err = -EINVAL;
3453         if (mreq->mr_alen > dev->addr_len)
3454                 goto done;
3455
3456         err = -ENOBUFS;
3457         i = kmalloc(sizeof(*i), GFP_KERNEL);
3458         if (i == NULL)
3459                 goto done;
3460
3461         err = 0;
3462         for (ml = po->mclist; ml; ml = ml->next) {
3463                 if (ml->ifindex == mreq->mr_ifindex &&
3464                     ml->type == mreq->mr_type &&
3465                     ml->alen == mreq->mr_alen &&
3466                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3467                         ml->count++;
3468                         /* Free the new element ... */
3469                         kfree(i);
3470                         goto done;
3471                 }
3472         }
3473
3474         i->type = mreq->mr_type;
3475         i->ifindex = mreq->mr_ifindex;
3476         i->alen = mreq->mr_alen;
3477         memcpy(i->addr, mreq->mr_address, i->alen);
3478         memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3479         i->count = 1;
3480         i->next = po->mclist;
3481         po->mclist = i;
3482         err = packet_dev_mc(dev, i, 1);
3483         if (err) {
3484                 po->mclist = i->next;
3485                 kfree(i);
3486         }
3487
3488 done:
3489         rtnl_unlock();
3490         return err;
3491 }
3492
3493 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3494 {
3495         struct packet_mclist *ml, **mlp;
3496
3497         rtnl_lock();
3498
3499         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3500                 if (ml->ifindex == mreq->mr_ifindex &&
3501                     ml->type == mreq->mr_type &&
3502                     ml->alen == mreq->mr_alen &&
3503                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3504                         if (--ml->count == 0) {
3505                                 struct net_device *dev;
3506                                 *mlp = ml->next;
3507                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3508                                 if (dev)
3509                                         packet_dev_mc(dev, ml, -1);
3510                                 kfree(ml);
3511                         }
3512                         break;
3513                 }
3514         }
3515         rtnl_unlock();
3516         return 0;
3517 }
3518
3519 static void packet_flush_mclist(struct sock *sk)
3520 {
3521         struct packet_sock *po = pkt_sk(sk);
3522         struct packet_mclist *ml;
3523
3524         if (!po->mclist)
3525                 return;
3526
3527         rtnl_lock();
3528         while ((ml = po->mclist) != NULL) {
3529                 struct net_device *dev;
3530
3531                 po->mclist = ml->next;
3532                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3533                 if (dev != NULL)
3534                         packet_dev_mc(dev, ml, -1);
3535                 kfree(ml);
3536         }
3537         rtnl_unlock();
3538 }
3539
3540 static int
3541 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3542 {
3543         struct sock *sk = sock->sk;
3544         struct packet_sock *po = pkt_sk(sk);
3545         int ret;
3546
3547         if (level != SOL_PACKET)
3548                 return -ENOPROTOOPT;
3549
3550         switch (optname) {
3551         case PACKET_ADD_MEMBERSHIP:
3552         case PACKET_DROP_MEMBERSHIP:
3553         {
3554                 struct packet_mreq_max mreq;
3555                 int len = optlen;
3556                 memset(&mreq, 0, sizeof(mreq));
3557                 if (len < sizeof(struct packet_mreq))
3558                         return -EINVAL;
3559                 if (len > sizeof(mreq))
3560                         len = sizeof(mreq);
3561                 if (copy_from_user(&mreq, optval, len))
3562                         return -EFAULT;
3563                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3564                         return -EINVAL;
3565                 if (optname == PACKET_ADD_MEMBERSHIP)
3566                         ret = packet_mc_add(sk, &mreq);
3567                 else
3568                         ret = packet_mc_drop(sk, &mreq);
3569                 return ret;
3570         }
3571
3572         case PACKET_RX_RING:
3573         case PACKET_TX_RING:
3574         {
3575                 union tpacket_req_u req_u;
3576                 int len;
3577
3578                 switch (po->tp_version) {
3579                 case TPACKET_V1:
3580                 case TPACKET_V2:
3581                         len = sizeof(req_u.req);
3582                         break;
3583                 case TPACKET_V3:
3584                 default:
3585                         len = sizeof(req_u.req3);
3586                         break;
3587                 }
3588                 if (optlen < len)
3589                         return -EINVAL;
3590                 if (copy_from_user(&req_u.req, optval, len))
3591                         return -EFAULT;
3592                 return packet_set_ring(sk, &req_u, 0,
3593                         optname == PACKET_TX_RING);
3594         }
3595         case PACKET_COPY_THRESH:
3596         {
3597                 int val;
3598
3599                 if (optlen != sizeof(val))
3600                         return -EINVAL;
3601                 if (copy_from_user(&val, optval, sizeof(val)))
3602                         return -EFAULT;
3603
3604                 pkt_sk(sk)->copy_thresh = val;
3605                 return 0;
3606         }
3607         case PACKET_VERSION:
3608         {
3609                 int val;
3610
3611                 if (optlen != sizeof(val))
3612                         return -EINVAL;
3613                 if (copy_from_user(&val, optval, sizeof(val)))
3614                         return -EFAULT;
3615                 switch (val) {
3616                 case TPACKET_V1:
3617                 case TPACKET_V2:
3618                 case TPACKET_V3:
3619                         break;
3620                 default:
3621                         return -EINVAL;
3622                 }
3623                 lock_sock(sk);
3624                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3625                         ret = -EBUSY;
3626                 } else {
3627                         po->tp_version = val;
3628                         ret = 0;
3629                 }
3630                 release_sock(sk);
3631                 return ret;
3632         }
3633         case PACKET_RESERVE:
3634         {
3635                 unsigned int val;
3636
3637                 if (optlen != sizeof(val))
3638                         return -EINVAL;
3639                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3640                         return -EBUSY;
3641                 if (copy_from_user(&val, optval, sizeof(val)))
3642                         return -EFAULT;
3643                 po->tp_reserve = val;
3644                 return 0;
3645         }
3646         case PACKET_LOSS:
3647         {
3648                 unsigned int val;
3649
3650                 if (optlen != sizeof(val))
3651                         return -EINVAL;
3652                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3653                         return -EBUSY;
3654                 if (copy_from_user(&val, optval, sizeof(val)))
3655                         return -EFAULT;
3656                 po->tp_loss = !!val;
3657                 return 0;
3658         }
3659         case PACKET_AUXDATA:
3660         {
3661                 int val;
3662
3663                 if (optlen < sizeof(val))
3664                         return -EINVAL;
3665                 if (copy_from_user(&val, optval, sizeof(val)))
3666                         return -EFAULT;
3667
3668                 po->auxdata = !!val;
3669                 return 0;
3670         }
3671         case PACKET_ORIGDEV:
3672         {
3673                 int val;
3674
3675                 if (optlen < sizeof(val))
3676                         return -EINVAL;
3677                 if (copy_from_user(&val, optval, sizeof(val)))
3678                         return -EFAULT;
3679
3680                 po->origdev = !!val;
3681                 return 0;
3682         }
3683         case PACKET_VNET_HDR:
3684         {
3685                 int val;
3686
3687                 if (sock->type != SOCK_RAW)
3688                         return -EINVAL;
3689                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3690                         return -EBUSY;
3691                 if (optlen < sizeof(val))
3692                         return -EINVAL;
3693                 if (copy_from_user(&val, optval, sizeof(val)))
3694                         return -EFAULT;
3695
3696                 po->has_vnet_hdr = !!val;
3697                 return 0;
3698         }
3699         case PACKET_TIMESTAMP:
3700         {
3701                 int val;
3702
3703                 if (optlen != sizeof(val))
3704                         return -EINVAL;
3705                 if (copy_from_user(&val, optval, sizeof(val)))
3706                         return -EFAULT;
3707
3708                 po->tp_tstamp = val;
3709                 return 0;
3710         }
3711         case PACKET_FANOUT:
3712         {
3713                 int val;
3714
3715                 if (optlen != sizeof(val))
3716                         return -EINVAL;
3717                 if (copy_from_user(&val, optval, sizeof(val)))
3718                         return -EFAULT;
3719
3720                 return fanout_add(sk, val & 0xffff, val >> 16);
3721         }
3722         case PACKET_FANOUT_DATA:
3723         {
3724                 if (!po->fanout)
3725                         return -EINVAL;
3726
3727                 return fanout_set_data(po, optval, optlen);
3728         }
3729         case PACKET_TX_HAS_OFF:
3730         {
3731                 unsigned int val;
3732
3733                 if (optlen != sizeof(val))
3734                         return -EINVAL;
3735                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3736                         return -EBUSY;
3737                 if (copy_from_user(&val, optval, sizeof(val)))
3738                         return -EFAULT;
3739                 po->tp_tx_has_off = !!val;
3740                 return 0;
3741         }
3742         case PACKET_QDISC_BYPASS:
3743         {
3744                 int val;
3745
3746                 if (optlen != sizeof(val))
3747                         return -EINVAL;
3748                 if (copy_from_user(&val, optval, sizeof(val)))
3749                         return -EFAULT;
3750
3751                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3752                 return 0;
3753         }
3754         default:
3755                 return -ENOPROTOOPT;
3756         }
3757 }
3758
3759 static int packet_getsockopt(struct socket *sock, int level, int optname,
3760                              char __user *optval, int __user *optlen)
3761 {
3762         int len;
3763         int val, lv = sizeof(val);
3764         struct sock *sk = sock->sk;
3765         struct packet_sock *po = pkt_sk(sk);
3766         void *data = &val;
3767         union tpacket_stats_u st;
3768         struct tpacket_rollover_stats rstats;
3769
3770         if (level != SOL_PACKET)
3771                 return -ENOPROTOOPT;
3772
3773         if (get_user(len, optlen))
3774                 return -EFAULT;
3775
3776         if (len < 0)
3777                 return -EINVAL;
3778
3779         switch (optname) {
3780         case PACKET_STATISTICS:
3781                 spin_lock_bh(&sk->sk_receive_queue.lock);
3782                 memcpy(&st, &po->stats, sizeof(st));
3783                 memset(&po->stats, 0, sizeof(po->stats));
3784                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3785
3786                 if (po->tp_version == TPACKET_V3) {
3787                         lv = sizeof(struct tpacket_stats_v3);
3788                         st.stats3.tp_packets += st.stats3.tp_drops;
3789                         data = &st.stats3;
3790                 } else {
3791                         lv = sizeof(struct tpacket_stats);
3792                         st.stats1.tp_packets += st.stats1.tp_drops;
3793                         data = &st.stats1;
3794                 }
3795
3796                 break;
3797         case PACKET_AUXDATA:
3798                 val = po->auxdata;
3799                 break;
3800         case PACKET_ORIGDEV:
3801                 val = po->origdev;
3802                 break;
3803         case PACKET_VNET_HDR:
3804                 val = po->has_vnet_hdr;
3805                 break;
3806         case PACKET_VERSION:
3807                 val = po->tp_version;
3808                 break;
3809         case PACKET_HDRLEN:
3810                 if (len > sizeof(int))
3811                         len = sizeof(int);
3812                 if (copy_from_user(&val, optval, len))
3813                         return -EFAULT;
3814                 switch (val) {
3815                 case TPACKET_V1:
3816                         val = sizeof(struct tpacket_hdr);
3817                         break;
3818                 case TPACKET_V2:
3819                         val = sizeof(struct tpacket2_hdr);
3820                         break;
3821                 case TPACKET_V3:
3822                         val = sizeof(struct tpacket3_hdr);
3823                         break;
3824                 default:
3825                         return -EINVAL;
3826                 }
3827                 break;
3828         case PACKET_RESERVE:
3829                 val = po->tp_reserve;
3830                 break;
3831         case PACKET_LOSS:
3832                 val = po->tp_loss;
3833                 break;
3834         case PACKET_TIMESTAMP:
3835                 val = po->tp_tstamp;
3836                 break;
3837         case PACKET_FANOUT:
3838                 val = (po->fanout ?
3839                        ((u32)po->fanout->id |
3840                         ((u32)po->fanout->type << 16) |
3841                         ((u32)po->fanout->flags << 24)) :
3842                        0);
3843                 break;
3844         case PACKET_ROLLOVER_STATS:
3845                 if (!po->rollover)
3846                         return -EINVAL;
3847                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3848                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3849                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3850                 data = &rstats;
3851                 lv = sizeof(rstats);
3852                 break;
3853         case PACKET_TX_HAS_OFF:
3854                 val = po->tp_tx_has_off;
3855                 break;
3856         case PACKET_QDISC_BYPASS:
3857                 val = packet_use_direct_xmit(po);
3858                 break;
3859         default:
3860                 return -ENOPROTOOPT;
3861         }
3862
3863         if (len > lv)
3864                 len = lv;
3865         if (put_user(len, optlen))
3866                 return -EFAULT;
3867         if (copy_to_user(optval, data, len))
3868                 return -EFAULT;
3869         return 0;
3870 }
3871
3872
3873 #ifdef CONFIG_COMPAT
3874 static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
3875                                     char __user *optval, unsigned int optlen)
3876 {
3877         struct packet_sock *po = pkt_sk(sock->sk);
3878
3879         if (level != SOL_PACKET)
3880                 return -ENOPROTOOPT;
3881
3882         if (optname == PACKET_FANOUT_DATA &&
3883             po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
3884                 optval = (char __user *)get_compat_bpf_fprog(optval);
3885                 if (!optval)
3886                         return -EFAULT;
3887                 optlen = sizeof(struct sock_fprog);
3888         }
3889
3890         return packet_setsockopt(sock, level, optname, optval, optlen);
3891 }
3892 #endif
3893
3894 static int packet_notifier(struct notifier_block *this,
3895                            unsigned long msg, void *ptr)
3896 {
3897         struct sock *sk;
3898         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3899         struct net *net = dev_net(dev);
3900
3901         rcu_read_lock();
3902         sk_for_each_rcu(sk, &net->packet.sklist) {
3903                 struct packet_sock *po = pkt_sk(sk);
3904
3905                 switch (msg) {
3906                 case NETDEV_UNREGISTER:
3907                         if (po->mclist)
3908                                 packet_dev_mclist_delete(dev, &po->mclist);
3909                         /* fallthrough */
3910
3911                 case NETDEV_DOWN:
3912                         if (dev->ifindex == po->ifindex) {
3913                                 spin_lock(&po->bind_lock);
3914                                 if (po->running) {
3915                                         __unregister_prot_hook(sk, false);
3916                                         sk->sk_err = ENETDOWN;
3917                                         if (!sock_flag(sk, SOCK_DEAD))
3918                                                 sk->sk_error_report(sk);
3919                                 }
3920                                 if (msg == NETDEV_UNREGISTER) {
3921                                         packet_cached_dev_reset(po);
3922                                         po->ifindex = -1;
3923                                         if (po->prot_hook.dev)
3924                                                 dev_put(po->prot_hook.dev);
3925                                         po->prot_hook.dev = NULL;
3926                                 }
3927                                 spin_unlock(&po->bind_lock);
3928                         }
3929                         break;
3930                 case NETDEV_UP:
3931                         if (dev->ifindex == po->ifindex) {
3932                                 spin_lock(&po->bind_lock);
3933                                 if (po->num)
3934                                         register_prot_hook(sk);
3935                                 spin_unlock(&po->bind_lock);
3936                         }
3937                         break;
3938                 }
3939         }
3940         rcu_read_unlock();
3941         return NOTIFY_DONE;
3942 }
3943
3944
3945 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3946                         unsigned long arg)
3947 {
3948         struct sock *sk = sock->sk;
3949
3950         switch (cmd) {
3951         case SIOCOUTQ:
3952         {
3953                 int amount = sk_wmem_alloc_get(sk);
3954
3955                 return put_user(amount, (int __user *)arg);
3956         }
3957         case SIOCINQ:
3958         {
3959                 struct sk_buff *skb;
3960                 int amount = 0;
3961
3962                 spin_lock_bh(&sk->sk_receive_queue.lock);
3963                 skb = skb_peek(&sk->sk_receive_queue);
3964                 if (skb)
3965                         amount = skb->len;
3966                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3967                 return put_user(amount, (int __user *)arg);
3968         }
3969         case SIOCGSTAMP:
3970                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3971         case SIOCGSTAMPNS:
3972                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3973
3974 #ifdef CONFIG_INET
3975         case SIOCADDRT:
3976         case SIOCDELRT:
3977         case SIOCDARP:
3978         case SIOCGARP:
3979         case SIOCSARP:
3980         case SIOCGIFADDR:
3981         case SIOCSIFADDR:
3982         case SIOCGIFBRDADDR:
3983         case SIOCSIFBRDADDR:
3984         case SIOCGIFNETMASK:
3985         case SIOCSIFNETMASK:
3986         case SIOCGIFDSTADDR:
3987         case SIOCSIFDSTADDR:
3988         case SIOCSIFFLAGS:
3989                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3990 #endif
3991
3992         default:
3993                 return -ENOIOCTLCMD;
3994         }
3995         return 0;
3996 }
3997
3998 static unsigned int packet_poll(struct file *file, struct socket *sock,
3999                                 poll_table *wait)
4000 {
4001         struct sock *sk = sock->sk;
4002         struct packet_sock *po = pkt_sk(sk);
4003         unsigned int mask = datagram_poll(file, sock, wait);
4004
4005         spin_lock_bh(&sk->sk_receive_queue.lock);
4006         if (po->rx_ring.pg_vec) {
4007                 if (!packet_previous_rx_frame(po, &po->rx_ring,
4008                         TP_STATUS_KERNEL))
4009                         mask |= POLLIN | POLLRDNORM;
4010         }
4011         if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4012                 po->pressure = 0;
4013         spin_unlock_bh(&sk->sk_receive_queue.lock);
4014         spin_lock_bh(&sk->sk_write_queue.lock);
4015         if (po->tx_ring.pg_vec) {
4016                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4017                         mask |= POLLOUT | POLLWRNORM;
4018         }
4019         spin_unlock_bh(&sk->sk_write_queue.lock);
4020         return mask;
4021 }
4022
4023
4024 /* Dirty? Well, I still did not learn better way to account
4025  * for user mmaps.
4026  */
4027
4028 static void packet_mm_open(struct vm_area_struct *vma)
4029 {
4030         struct file *file = vma->vm_file;
4031         struct socket *sock = file->private_data;
4032         struct sock *sk = sock->sk;
4033
4034         if (sk)
4035                 atomic_inc(&pkt_sk(sk)->mapped);
4036 }
4037
4038 static void packet_mm_close(struct vm_area_struct *vma)
4039 {
4040         struct file *file = vma->vm_file;
4041         struct socket *sock = file->private_data;
4042         struct sock *sk = sock->sk;
4043
4044         if (sk)
4045                 atomic_dec(&pkt_sk(sk)->mapped);
4046 }
4047
4048 static const struct vm_operations_struct packet_mmap_ops = {
4049         .open   =       packet_mm_open,
4050         .close  =       packet_mm_close,
4051 };
4052
4053 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4054                         unsigned int len)
4055 {
4056         int i;
4057
4058         for (i = 0; i < len; i++) {
4059                 if (likely(pg_vec[i].buffer)) {
4060                         if (is_vmalloc_addr(pg_vec[i].buffer))
4061                                 vfree(pg_vec[i].buffer);
4062                         else
4063                                 free_pages((unsigned long)pg_vec[i].buffer,
4064                                            order);
4065                         pg_vec[i].buffer = NULL;
4066                 }
4067         }
4068         kfree(pg_vec);
4069 }
4070
4071 static char *alloc_one_pg_vec_page(unsigned long order)
4072 {
4073         char *buffer;
4074         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4075                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4076
4077         buffer = (char *) __get_free_pages(gfp_flags, order);
4078         if (buffer)
4079                 return buffer;
4080
4081         /* __get_free_pages failed, fall back to vmalloc */
4082         buffer = vzalloc((1 << order) * PAGE_SIZE);
4083         if (buffer)
4084                 return buffer;
4085
4086         /* vmalloc failed, lets dig into swap here */
4087         gfp_flags &= ~__GFP_NORETRY;
4088         buffer = (char *) __get_free_pages(gfp_flags, order);
4089         if (buffer)
4090                 return buffer;
4091
4092         /* complete and utter failure */
4093         return NULL;
4094 }
4095
4096 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4097 {
4098         unsigned int block_nr = req->tp_block_nr;
4099         struct pgv *pg_vec;
4100         int i;
4101
4102         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4103         if (unlikely(!pg_vec))
4104                 goto out;
4105
4106         for (i = 0; i < block_nr; i++) {
4107                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4108                 if (unlikely(!pg_vec[i].buffer))
4109                         goto out_free_pgvec;
4110         }
4111
4112 out:
4113         return pg_vec;
4114
4115 out_free_pgvec:
4116         free_pg_vec(pg_vec, order, block_nr);
4117         pg_vec = NULL;
4118         goto out;
4119 }
4120
4121 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4122                 int closing, int tx_ring)
4123 {
4124         struct pgv *pg_vec = NULL;
4125         struct packet_sock *po = pkt_sk(sk);
4126         int was_running, order = 0;
4127         struct packet_ring_buffer *rb;
4128         struct sk_buff_head *rb_queue;
4129         __be16 num;
4130         int err = -EINVAL;
4131         /* Added to avoid minimal code churn */
4132         struct tpacket_req *req = &req_u->req;
4133
4134         lock_sock(sk);
4135         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4136         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4137                 net_warn_ratelimited("Tx-ring is not supported.\n");
4138                 goto out;
4139         }
4140
4141         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4142         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4143
4144         err = -EBUSY;
4145         if (!closing) {
4146                 if (atomic_read(&po->mapped))
4147                         goto out;
4148                 if (packet_read_pending(rb))
4149                         goto out;
4150         }
4151
4152         if (req->tp_block_nr) {
4153                 /* Sanity tests and some calculations */
4154                 err = -EBUSY;
4155                 if (unlikely(rb->pg_vec))
4156                         goto out;
4157
4158                 switch (po->tp_version) {
4159                 case TPACKET_V1:
4160                         po->tp_hdrlen = TPACKET_HDRLEN;
4161                         break;
4162                 case TPACKET_V2:
4163                         po->tp_hdrlen = TPACKET2_HDRLEN;
4164                         break;
4165                 case TPACKET_V3:
4166                         po->tp_hdrlen = TPACKET3_HDRLEN;
4167                         break;
4168                 }
4169
4170                 err = -EINVAL;
4171                 if (unlikely((int)req->tp_block_size <= 0))
4172                         goto out;
4173                 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4174                         goto out;
4175                 if (po->tp_version >= TPACKET_V3 &&
4176                     (int)(req->tp_block_size -
4177                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4178                         goto out;
4179                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4180                                         po->tp_reserve))
4181                         goto out;
4182                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4183                         goto out;
4184
4185                 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4186                 if (unlikely(rb->frames_per_block == 0))
4187                         goto out;
4188                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4189                                         req->tp_frame_nr))
4190                         goto out;
4191
4192                 err = -ENOMEM;
4193                 order = get_order(req->tp_block_size);
4194                 pg_vec = alloc_pg_vec(req, order);
4195                 if (unlikely(!pg_vec))
4196                         goto out;
4197                 switch (po->tp_version) {
4198                 case TPACKET_V3:
4199                 /* Transmit path is not supported. We checked
4200                  * it above but just being paranoid
4201                  */
4202                         if (!tx_ring)
4203                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4204                         break;
4205                 default:
4206                         break;
4207                 }
4208         }
4209         /* Done */
4210         else {
4211                 err = -EINVAL;
4212                 if (unlikely(req->tp_frame_nr))
4213                         goto out;
4214         }
4215
4216
4217         /* Detach socket from network */
4218         spin_lock(&po->bind_lock);
4219         was_running = po->running;
4220         num = po->num;
4221         if (was_running) {
4222                 po->num = 0;
4223                 __unregister_prot_hook(sk, false);
4224         }
4225         spin_unlock(&po->bind_lock);
4226
4227         synchronize_net();
4228
4229         err = -EBUSY;
4230         mutex_lock(&po->pg_vec_lock);
4231         if (closing || atomic_read(&po->mapped) == 0) {
4232                 err = 0;
4233                 spin_lock_bh(&rb_queue->lock);
4234                 swap(rb->pg_vec, pg_vec);
4235                 rb->frame_max = (req->tp_frame_nr - 1);
4236                 rb->head = 0;
4237                 rb->frame_size = req->tp_frame_size;
4238                 spin_unlock_bh(&rb_queue->lock);
4239
4240                 swap(rb->pg_vec_order, order);
4241                 swap(rb->pg_vec_len, req->tp_block_nr);
4242
4243                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4244                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4245                                                 tpacket_rcv : packet_rcv;
4246                 skb_queue_purge(rb_queue);
4247                 if (atomic_read(&po->mapped))
4248                         pr_err("packet_mmap: vma is busy: %d\n",
4249                                atomic_read(&po->mapped));
4250         }
4251         mutex_unlock(&po->pg_vec_lock);
4252
4253         spin_lock(&po->bind_lock);
4254         if (was_running) {
4255                 po->num = num;
4256                 register_prot_hook(sk);
4257         }
4258         spin_unlock(&po->bind_lock);
4259         if (closing && (po->tp_version > TPACKET_V2)) {
4260                 /* Because we don't support block-based V3 on tx-ring */
4261                 if (!tx_ring)
4262                         prb_shutdown_retire_blk_timer(po, rb_queue);
4263         }
4264
4265         if (pg_vec)
4266                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4267 out:
4268         release_sock(sk);
4269         return err;
4270 }
4271
4272 static int packet_mmap(struct file *file, struct socket *sock,
4273                 struct vm_area_struct *vma)
4274 {
4275         struct sock *sk = sock->sk;
4276         struct packet_sock *po = pkt_sk(sk);
4277         unsigned long size, expected_size;
4278         struct packet_ring_buffer *rb;
4279         unsigned long start;
4280         int err = -EINVAL;
4281         int i;
4282
4283         if (vma->vm_pgoff)
4284                 return -EINVAL;
4285
4286         mutex_lock(&po->pg_vec_lock);
4287
4288         expected_size = 0;
4289         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4290                 if (rb->pg_vec) {
4291                         expected_size += rb->pg_vec_len
4292                                                 * rb->pg_vec_pages
4293                                                 * PAGE_SIZE;
4294                 }
4295         }
4296
4297         if (expected_size == 0)
4298                 goto out;
4299
4300         size = vma->vm_end - vma->vm_start;
4301         if (size != expected_size)
4302                 goto out;
4303
4304         start = vma->vm_start;
4305         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4306                 if (rb->pg_vec == NULL)
4307                         continue;
4308
4309                 for (i = 0; i < rb->pg_vec_len; i++) {
4310                         struct page *page;
4311                         void *kaddr = rb->pg_vec[i].buffer;
4312                         int pg_num;
4313
4314                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4315                                 page = pgv_to_page(kaddr);
4316                                 err = vm_insert_page(vma, start, page);
4317                                 if (unlikely(err))
4318                                         goto out;
4319                                 start += PAGE_SIZE;
4320                                 kaddr += PAGE_SIZE;
4321                         }
4322                 }
4323         }
4324
4325         atomic_inc(&po->mapped);
4326         vma->vm_ops = &packet_mmap_ops;
4327         err = 0;
4328
4329 out:
4330         mutex_unlock(&po->pg_vec_lock);
4331         return err;
4332 }
4333
4334 static const struct proto_ops packet_ops_spkt = {
4335         .family =       PF_PACKET,
4336         .owner =        THIS_MODULE,
4337         .release =      packet_release,
4338         .bind =         packet_bind_spkt,
4339         .connect =      sock_no_connect,
4340         .socketpair =   sock_no_socketpair,
4341         .accept =       sock_no_accept,
4342         .getname =      packet_getname_spkt,
4343         .poll =         datagram_poll,
4344         .ioctl =        packet_ioctl,
4345         .listen =       sock_no_listen,
4346         .shutdown =     sock_no_shutdown,
4347         .setsockopt =   sock_no_setsockopt,
4348         .getsockopt =   sock_no_getsockopt,
4349         .sendmsg =      packet_sendmsg_spkt,
4350         .recvmsg =      packet_recvmsg,
4351         .mmap =         sock_no_mmap,
4352         .sendpage =     sock_no_sendpage,
4353 };
4354
4355 static const struct proto_ops packet_ops = {
4356         .family =       PF_PACKET,
4357         .owner =        THIS_MODULE,
4358         .release =      packet_release,
4359         .bind =         packet_bind,
4360         .connect =      sock_no_connect,
4361         .socketpair =   sock_no_socketpair,
4362         .accept =       sock_no_accept,
4363         .getname =      packet_getname,
4364         .poll =         packet_poll,
4365         .ioctl =        packet_ioctl,
4366         .listen =       sock_no_listen,
4367         .shutdown =     sock_no_shutdown,
4368         .setsockopt =   packet_setsockopt,
4369         .getsockopt =   packet_getsockopt,
4370 #ifdef CONFIG_COMPAT
4371         .compat_setsockopt = compat_packet_setsockopt,
4372 #endif
4373         .sendmsg =      packet_sendmsg,
4374         .recvmsg =      packet_recvmsg,
4375         .mmap =         packet_mmap,
4376         .sendpage =     sock_no_sendpage,
4377 };
4378
4379 static const struct net_proto_family packet_family_ops = {
4380         .family =       PF_PACKET,
4381         .create =       packet_create,
4382         .owner  =       THIS_MODULE,
4383 };
4384
4385 static struct notifier_block packet_netdev_notifier = {
4386         .notifier_call =        packet_notifier,
4387 };
4388
4389 #ifdef CONFIG_PROC_FS
4390
4391 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4392         __acquires(RCU)
4393 {
4394         struct net *net = seq_file_net(seq);
4395
4396         rcu_read_lock();
4397         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4398 }
4399
4400 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4401 {
4402         struct net *net = seq_file_net(seq);
4403         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4404 }
4405
4406 static void packet_seq_stop(struct seq_file *seq, void *v)
4407         __releases(RCU)
4408 {
4409         rcu_read_unlock();
4410 }
4411
4412 static int packet_seq_show(struct seq_file *seq, void *v)
4413 {
4414         if (v == SEQ_START_TOKEN)
4415                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4416         else {
4417                 struct sock *s = sk_entry(v);
4418                 const struct packet_sock *po = pkt_sk(s);
4419
4420                 seq_printf(seq,
4421                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4422                            s,
4423                            atomic_read(&s->sk_refcnt),
4424                            s->sk_type,
4425                            ntohs(po->num),
4426                            po->ifindex,
4427                            po->running,
4428                            atomic_read(&s->sk_rmem_alloc),
4429                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4430                            sock_i_ino(s));
4431         }
4432
4433         return 0;
4434 }
4435
4436 static const struct seq_operations packet_seq_ops = {
4437         .start  = packet_seq_start,
4438         .next   = packet_seq_next,
4439         .stop   = packet_seq_stop,
4440         .show   = packet_seq_show,
4441 };
4442
4443 static int packet_seq_open(struct inode *inode, struct file *file)
4444 {
4445         return seq_open_net(inode, file, &packet_seq_ops,
4446                             sizeof(struct seq_net_private));
4447 }
4448
4449 static const struct file_operations packet_seq_fops = {
4450         .owner          = THIS_MODULE,
4451         .open           = packet_seq_open,
4452         .read           = seq_read,
4453         .llseek         = seq_lseek,
4454         .release        = seq_release_net,
4455 };
4456
4457 #endif
4458
4459 static int __net_init packet_net_init(struct net *net)
4460 {
4461         mutex_init(&net->packet.sklist_lock);
4462         INIT_HLIST_HEAD(&net->packet.sklist);
4463
4464         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4465                 return -ENOMEM;
4466
4467         return 0;
4468 }
4469
4470 static void __net_exit packet_net_exit(struct net *net)
4471 {
4472         remove_proc_entry("packet", net->proc_net);
4473 }
4474
4475 static struct pernet_operations packet_net_ops = {
4476         .init = packet_net_init,
4477         .exit = packet_net_exit,
4478 };
4479
4480
4481 static void __exit packet_exit(void)
4482 {
4483         unregister_netdevice_notifier(&packet_netdev_notifier);
4484         unregister_pernet_subsys(&packet_net_ops);
4485         sock_unregister(PF_PACKET);
4486         proto_unregister(&packet_proto);
4487 }
4488
4489 static int __init packet_init(void)
4490 {
4491         int rc = proto_register(&packet_proto, 0);
4492
4493         if (rc != 0)
4494                 goto out;
4495
4496         sock_register(&packet_family_ops);
4497         register_pernet_subsys(&packet_net_ops);
4498         register_netdevice_notifier(&packet_netdev_notifier);
4499 out:
4500         return rc;
4501 }
4502
4503 module_init(packet_init);
4504 module_exit(packet_exit);
4505 MODULE_LICENSE("GPL");
4506 MODULE_ALIAS_NETPROTO(PF_PACKET);