net/netfilter/nf_conntrack_proto_sctp.c

   1 /*
   2  * Connection tracking protocol helper module for SCTP.
   3  *
   4  * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
   5  * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
   6  *
   7  * SCTP is defined in RFC 2960. References to various sections in this code
   8  * are to this RFC.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/types.h>
  16 #include <linux/timer.h>
  17 #include <linux/netfilter.h>
  18 #include <linux/in.h>
  19 #include <linux/ip.h>
  20 #include <linux/sctp.h>
  21 #include <linux/string.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/interrupt.h>
  25 #include <net/sctp/checksum.h>
  26
  27 #include <net/netfilter/nf_log.h>
  28 #include <net/netfilter/nf_conntrack.h>
  29 #include <net/netfilter/nf_conntrack_l4proto.h>
  30 #include <net/netfilter/nf_conntrack_ecache.h>
  31 #include <net/netfilter/nf_conntrack_timeout.h>
  32
  33 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  34    closely.  They're more complex. --RR
  35
  36    And so for me for SCTP :D -Kiran */
  37
  38 static const char *const sctp_conntrack_names[] = {
  39         "NONE",
  40         "CLOSED",
  41         "COOKIE_WAIT",
  42         "COOKIE_ECHOED",
  43         "ESTABLISHED",
  44         "SHUTDOWN_SENT",
  45         "SHUTDOWN_RECD",
  46         "SHUTDOWN_ACK_SENT",
  47         "HEARTBEAT_SENT",
  48         "HEARTBEAT_ACKED",
  49 };
  50
  51 #define SECS  * HZ
  52 #define MINS  * 60 SECS
  53 #define HOURS * 60 MINS
  54 #define DAYS  * 24 HOURS
  55
  56 static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
  57         [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  58         [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  59         [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  60         [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  61         [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  62         [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  63         [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  64         [SCTP_CONNTRACK_HEARTBEAT_SENT]         = 30 SECS,
  65         [SCTP_CONNTRACK_HEARTBEAT_ACKED]        = 210 SECS,
  66 };
  67
  68 #define sNO SCTP_CONNTRACK_NONE
  69 #define sCL SCTP_CONNTRACK_CLOSED
  70 #define sCW SCTP_CONNTRACK_COOKIE_WAIT
  71 #define sCE SCTP_CONNTRACK_COOKIE_ECHOED
  72 #define sES SCTP_CONNTRACK_ESTABLISHED
  73 #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
  74 #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
  75 #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
  76 #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
  77 #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
  78 #define sIV SCTP_CONNTRACK_MAX
  79
  80 /*
  81         These are the descriptions of the states:
  82
  83 NOTE: These state names are tantalizingly similar to the states of an
  84 SCTP endpoint. But the interpretation of the states is a little different,
  85 considering that these are the states of the connection and not of an end
  86 point. Please note the subtleties. -Kiran
  87
  88 NONE              - Nothing so far.
  89 COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  90                     an INIT_ACK chunk in the reply direction.
  91 COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  92 ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  93 SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  94 SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  95 SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  96                     to that of the SHUTDOWN chunk.
  97 CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  98                     the SHUTDOWN chunk. Connection is closed.
  99 HEARTBEAT_SENT    - We have seen a HEARTBEAT in a new flow.
 100 HEARTBEAT_ACKED   - We have seen a HEARTBEAT-ACK in the direction opposite to
 101                     that of the HEARTBEAT chunk. Secondary connection is
 102                     established.
 103 */
 104
 105 /* TODO
 106  - I have assumed that the first INIT is in the original direction.
 107  This messes things when an INIT comes in the reply direction in CLOSED
 108  state.
 109  - Check the error type in the reply dir before transitioning from
 110 cookie echoed to closed.
 111  - Sec 5.2.4 of RFC 2960
 112  - Full Multi Homing support.
 113 */
 114
 115 /* SCTP conntrack state transitions */
 116 static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 117         {
 118 /*      ORIGINAL        */
 119 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 120 /* init         */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
 121 /* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
 122 /* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 123 /* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
 124 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
 125 /* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
 126 /* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
 127 /* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
 128 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
 129 /* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 130 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
 131         },
 132         {
 133 /*      REPLY   */
 134 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 135 /* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
 136 /* init_ack     */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
 137 /* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
 138 /* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
 139 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
 140 /* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
 141 /* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
 142 /* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
 143 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
 144 /* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 145 /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
 146         }
 147 };
 148
 149 static inline struct nf_sctp_net *sctp_pernet(struct net *net)
 150 {
 151         return &net->ct.nf_ct_proto.sctp;
 152 }
 153
 154 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 155 /* Print out the private part of the conntrack. */
 156 static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 157 {
 158         seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
 159 }
 160 #endif
 161
 162 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 163 for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0;        \
 164         (offset) < (skb)->len &&                                        \
 165         ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 166         (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 167
 168 /* Some validity checks to make sure the chunks are fine */
 169 static int do_basic_checks(struct nf_conn *ct,
 170                            const struct sk_buff *skb,
 171                            unsigned int dataoff,
 172                            unsigned long *map)
 173 {
 174         u_int32_t offset, count;
 175         struct sctp_chunkhdr _sch, *sch;
 176         int flag;
 177
 178         flag = 0;
 179
 180         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 181                 pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 182
 183                 if (sch->type == SCTP_CID_INIT ||
 184                     sch->type == SCTP_CID_INIT_ACK ||
 185                     sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 186                         flag = 1;
 187
 188                 /*
 189                  * Cookie Ack/Echo chunks not the first OR
 190                  * Init / Init Ack / Shutdown compl chunks not the only chunks
 191                  * OR zero-length.
 192                  */
 193                 if (((sch->type == SCTP_CID_COOKIE_ACK ||
 194                       sch->type == SCTP_CID_COOKIE_ECHO ||
 195                       flag) &&
 196                      count != 0) || !sch->length) {
 197                         pr_debug("Basic checks failed\n");
 198                         return 1;
 199                 }
 200
 201                 if (map)
 202                         set_bit(sch->type, map);
 203         }
 204
 205         pr_debug("Basic checks passed\n");
 206         return count == 0;
 207 }
 208
 209 static int sctp_new_state(enum ip_conntrack_dir dir,
 210                           enum sctp_conntrack cur_state,
 211                           int chunk_type)
 212 {
 213         int i;
 214
 215         pr_debug("Chunk type: %d\n", chunk_type);
 216
 217         switch (chunk_type) {
 218         case SCTP_CID_INIT:
 219                 pr_debug("SCTP_CID_INIT\n");
 220                 i = 0;
 221                 break;
 222         case SCTP_CID_INIT_ACK:
 223                 pr_debug("SCTP_CID_INIT_ACK\n");
 224                 i = 1;
 225                 break;
 226         case SCTP_CID_ABORT:
 227                 pr_debug("SCTP_CID_ABORT\n");
 228                 i = 2;
 229                 break;
 230         case SCTP_CID_SHUTDOWN:
 231                 pr_debug("SCTP_CID_SHUTDOWN\n");
 232                 i = 3;
 233                 break;
 234         case SCTP_CID_SHUTDOWN_ACK:
 235                 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 236                 i = 4;
 237                 break;
 238         case SCTP_CID_ERROR:
 239                 pr_debug("SCTP_CID_ERROR\n");
 240                 i = 5;
 241                 break;
 242         case SCTP_CID_COOKIE_ECHO:
 243                 pr_debug("SCTP_CID_COOKIE_ECHO\n");
 244                 i = 6;
 245                 break;
 246         case SCTP_CID_COOKIE_ACK:
 247                 pr_debug("SCTP_CID_COOKIE_ACK\n");
 248                 i = 7;
 249                 break;
 250         case SCTP_CID_SHUTDOWN_COMPLETE:
 251                 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 252                 i = 8;
 253                 break;
 254         case SCTP_CID_HEARTBEAT:
 255                 pr_debug("SCTP_CID_HEARTBEAT");
 256                 i = 9;
 257                 break;
 258         case SCTP_CID_HEARTBEAT_ACK:
 259                 pr_debug("SCTP_CID_HEARTBEAT_ACK");
 260                 i = 10;
 261                 break;
 262         default:
 263                 /* Other chunks like DATA or SACK do not change the state */
 264                 pr_debug("Unknown chunk type, Will stay in %s\n",
 265                          sctp_conntrack_names[cur_state]);
 266                 return cur_state;
 267         }
 268
 269         pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 270                  dir, sctp_conntrack_names[cur_state], chunk_type,
 271                  sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 272
 273         return sctp_conntracks[dir][i][cur_state];
 274 }
 275
 276 /* Don't need lock here: this conntrack not in circulation yet */
 277 static noinline bool
 278 sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 279          const struct sctphdr *sh, unsigned int dataoff)
 280 {
 281         enum sctp_conntrack new_state;
 282         const struct sctp_chunkhdr *sch;
 283         struct sctp_chunkhdr _sch;
 284         u32 offset, count;
 285
 286         memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 287         new_state = SCTP_CONNTRACK_MAX;
 288         for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) {
 289                 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 290                                            SCTP_CONNTRACK_NONE, sch->type);
 291
 292                 /* Invalid: delete conntrack */
 293                 if (new_state == SCTP_CONNTRACK_NONE ||
 294                     new_state == SCTP_CONNTRACK_MAX) {
 295                         pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 296                         return false;
 297                 }
 298
 299                 /* Copy the vtag into the state info */
 300                 if (sch->type == SCTP_CID_INIT) {
 301                         struct sctp_inithdr _inithdr, *ih;
 302                         /* Sec 8.5.1 (A) */
 303                         if (sh->vtag)
 304                                 return false;
 305
 306                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 307                                                 sizeof(_inithdr), &_inithdr);
 308                         if (!ih)
 309                                 return false;
 310
 311                         pr_debug("Setting vtag %x for new conn\n",
 312                                  ih->init_tag);
 313
 314                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
 315                 } else if (sch->type == SCTP_CID_HEARTBEAT) {
 316                         pr_debug("Setting vtag %x for secondary conntrack\n",
 317                                  sh->vtag);
 318                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
 319                 } else {
 320                 /* If it is a shutdown ack OOTB packet, we expect a return
 321                    shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 322                         pr_debug("Setting vtag %x for new conn OOTB\n",
 323                                  sh->vtag);
 324                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 325                 }
 326
 327                 ct->proto.sctp.state = new_state;
 328         }
 329
 330         return true;
 331 }
 332
 333 static bool sctp_error(struct sk_buff *skb,
 334                        unsigned int dataoff,
 335                        const struct nf_hook_state *state)
 336 {
 337         const struct sctphdr *sh;
 338         const char *logmsg;
 339
 340         if (skb->len < dataoff + sizeof(struct sctphdr)) {
 341                 logmsg = "nf_ct_sctp: short packet ";
 342                 goto out_invalid;
 343         }
 344         if (state->hook == NF_INET_PRE_ROUTING &&
 345             state->net->ct.sysctl_checksum &&
 346             skb->ip_summed == CHECKSUM_NONE) {
 347                 if (!skb_make_writable(skb, dataoff + sizeof(struct sctphdr))) {
 348                         logmsg = "nf_ct_sctp: failed to read header ";
 349                         goto out_invalid;
 350                 }
 351                 sh = (const struct sctphdr *)(skb->data + dataoff);
 352                 if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
 353                         logmsg = "nf_ct_sctp: bad CRC ";
 354                         goto out_invalid;
 355                 }
 356                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 357         }
 358         return false;
 359 out_invalid:
 360         nf_l4proto_log_invalid(skb, state->net, state->pf, IPPROTO_SCTP, "%s", logmsg);
 361         return true;
 362 }
 363
 364 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 365 static int sctp_packet(struct nf_conn *ct,
 366                        struct sk_buff *skb,
 367                        unsigned int dataoff,
 368                        enum ip_conntrack_info ctinfo,
 369                        const struct nf_hook_state *state)
 370 {
 371         enum sctp_conntrack new_state, old_state;
 372         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 373         const struct sctphdr *sh;
 374         struct sctphdr _sctph;
 375         const struct sctp_chunkhdr *sch;
 376         struct sctp_chunkhdr _sch;
 377         u_int32_t offset, count;
 378         unsigned int *timeouts;
 379         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 380
 381         if (sctp_error(skb, dataoff, state))
 382                 return -NF_ACCEPT;
 383
 384         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 385         if (sh == NULL)
 386                 goto out;
 387
 388         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 389                 goto out;
 390
 391         if (!nf_ct_is_confirmed(ct)) {
 392                 /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 393                 if (test_bit(SCTP_CID_ABORT, map) ||
 394                     test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 395                     test_bit(SCTP_CID_COOKIE_ACK, map))
 396                         return -NF_ACCEPT;
 397
 398                 if (!sctp_new(ct, skb, sh, dataoff))
 399                         return -NF_ACCEPT;
 400         }
 401
 402         /* Check the verification tag (Sec 8.5) */
 403         if (!test_bit(SCTP_CID_INIT, map) &&
 404             !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 405             !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 406             !test_bit(SCTP_CID_ABORT, map) &&
 407             !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 408             !test_bit(SCTP_CID_HEARTBEAT, map) &&
 409             !test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
 410             sh->vtag != ct->proto.sctp.vtag[dir]) {
 411                 pr_debug("Verification tag check failed\n");
 412                 goto out;
 413         }
 414
 415         old_state = new_state = SCTP_CONNTRACK_NONE;
 416         spin_lock_bh(&ct->lock);
 417         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 418                 /* Special cases of Verification tag check (Sec 8.5.1) */
 419                 if (sch->type == SCTP_CID_INIT) {
 420                         /* Sec 8.5.1 (A) */
 421                         if (sh->vtag != 0)
 422                                 goto out_unlock;
 423                 } else if (sch->type == SCTP_CID_ABORT) {
 424                         /* Sec 8.5.1 (B) */
 425                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 426                             sh->vtag != ct->proto.sctp.vtag[!dir])
 427                                 goto out_unlock;
 428                 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 429                         /* Sec 8.5.1 (C) */
 430                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 431                             sh->vtag != ct->proto.sctp.vtag[!dir] &&
 432                             sch->flags & SCTP_CHUNK_FLAG_T)
 433                                 goto out_unlock;
 434                 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 435                         /* Sec 8.5.1 (D) */
 436                         if (sh->vtag != ct->proto.sctp.vtag[dir])
 437                                 goto out_unlock;
 438                 } else if (sch->type == SCTP_CID_HEARTBEAT ||
 439                            sch->type == SCTP_CID_HEARTBEAT_ACK) {
 440                         if (ct->proto.sctp.vtag[dir] == 0) {
 441                                 pr_debug("Setting vtag %x for dir %d\n",
 442                                          sh->vtag, dir);
 443                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 444                         } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 445                                 pr_debug("Verification tag check failed\n");
 446                                 goto out_unlock;
 447                         }
 448                 }
 449
 450                 old_state = ct->proto.sctp.state;
 451                 new_state = sctp_new_state(dir, old_state, sch->type);
 452
 453                 /* Invalid */
 454                 if (new_state == SCTP_CONNTRACK_MAX) {
 455                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 456                                  "conntrack=%u\n",
 457                                  dir, sch->type, old_state);
 458                         goto out_unlock;
 459                 }
 460
 461                 /* If it is an INIT or an INIT ACK note down the vtag */
 462                 if (sch->type == SCTP_CID_INIT ||
 463                     sch->type == SCTP_CID_INIT_ACK) {
 464                         struct sctp_inithdr _inithdr, *ih;
 465
 466                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 467                                                 sizeof(_inithdr), &_inithdr);
 468                         if (ih == NULL)
 469                                 goto out_unlock;
 470                         pr_debug("Setting vtag %x for dir %d\n",
 471                                  ih->init_tag, !dir);
 472                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
 473                 }
 474
 475                 ct->proto.sctp.state = new_state;
 476                 if (old_state != new_state)
 477                         nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 478         }
 479         spin_unlock_bh(&ct->lock);
 480
 481         timeouts = nf_ct_timeout_lookup(ct);
 482         if (!timeouts)
 483                 timeouts = sctp_pernet(nf_ct_net(ct))->timeouts;
 484
 485         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 486
 487         if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 488             dir == IP_CT_DIR_REPLY &&
 489             new_state == SCTP_CONNTRACK_ESTABLISHED) {
 490                 pr_debug("Setting assured bit\n");
 491                 set_bit(IPS_ASSURED_BIT, &ct->status);
 492                 nf_conntrack_event_cache(IPCT_ASSURED, ct);
 493         }
 494
 495         return NF_ACCEPT;
 496
 497 out_unlock:
 498         spin_unlock_bh(&ct->lock);
 499 out:
 500         return -NF_ACCEPT;
 501 }
 502
 503 static bool sctp_can_early_drop(const struct nf_conn *ct)
 504 {
 505         switch (ct->proto.sctp.state) {
 506         case SCTP_CONNTRACK_SHUTDOWN_SENT:
 507         case SCTP_CONNTRACK_SHUTDOWN_RECD:
 508         case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
 509                 return true;
 510         default:
 511                 break;
 512         }
 513
 514         return false;
 515 }
 516
 517 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 518
 519 #include <linux/netfilter/nfnetlink.h>
 520 #include <linux/netfilter/nfnetlink_conntrack.h>
 521
 522 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 523                           struct nf_conn *ct)
 524 {
 525         struct nlattr *nest_parms;
 526
 527         spin_lock_bh(&ct->lock);
 528         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 529         if (!nest_parms)
 530                 goto nla_put_failure;
 531
 532         if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 533             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 534                          ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 535             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 536                          ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 537                 goto nla_put_failure;
 538
 539         spin_unlock_bh(&ct->lock);
 540
 541         nla_nest_end(skb, nest_parms);
 542
 543         return 0;
 544
 545 nla_put_failure:
 546         spin_unlock_bh(&ct->lock);
 547         return -1;
 548 }
 549
 550 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 551         [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 552         [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 553         [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 554 };
 555
 556 #define SCTP_NLATTR_SIZE ( \
 557                 NLA_ALIGN(NLA_HDRLEN + 1) + \
 558                 NLA_ALIGN(NLA_HDRLEN + 4) + \
 559                 NLA_ALIGN(NLA_HDRLEN + 4))
 560
 561 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 562 {
 563         struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 564         struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 565         int err;
 566
 567         /* updates may not contain the internal protocol info, skip parsing */
 568         if (!attr)
 569                 return 0;
 570
 571         err = nla_parse_nested(tb, CTA_PROTOINFO_SCTP_MAX, attr,
 572                                sctp_nla_policy, NULL);
 573         if (err < 0)
 574                 return err;
 575
 576         if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 577             !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 578             !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 579                 return -EINVAL;
 580
 581         spin_lock_bh(&ct->lock);
 582         ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 583         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 584                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 585         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 586                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 587         spin_unlock_bh(&ct->lock);
 588
 589         return 0;
 590 }
 591 #endif
 592
 593 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 594
 595 #include <linux/netfilter/nfnetlink.h>
 596 #include <linux/netfilter/nfnetlink_cttimeout.h>
 597
 598 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 599                                       struct net *net, void *data)
 600 {
 601         unsigned int *timeouts = data;
 602         struct nf_sctp_net *sn = sctp_pernet(net);
 603         int i;
 604
 605         /* set default SCTP timeouts. */
 606         for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 607                 timeouts[i] = sn->timeouts[i];
 608
 609         /* there's a 1:1 mapping between attributes and protocol states. */
 610         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 611                 if (tb[i]) {
 612                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 613                 }
 614         }
 615
 616         timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED];
 617         return 0;
 618 }
 619
 620 static int
 621 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 622 {
 623         const unsigned int *timeouts = data;
 624         int i;
 625
 626         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 627                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 628                         goto nla_put_failure;
 629         }
 630         return 0;
 631
 632 nla_put_failure:
 633         return -ENOSPC;
 634 }
 635
 636 static const struct nla_policy
 637 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 638         [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 639         [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 640         [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 641         [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 642         [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 643         [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 644         [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 645         [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT]       = { .type = NLA_U32 },
 646         [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED]      = { .type = NLA_U32 },
 647 };
 648 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 649
 650
 651 #ifdef CONFIG_SYSCTL
 652 static struct ctl_table sctp_sysctl_table[] = {
 653         {
 654                 .procname       = "nf_conntrack_sctp_timeout_closed",
 655                 .maxlen         = sizeof(unsigned int),
 656                 .mode           = 0644,
 657                 .proc_handler   = proc_dointvec_jiffies,
 658         },
 659         {
 660                 .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 661                 .maxlen         = sizeof(unsigned int),
 662                 .mode           = 0644,
 663                 .proc_handler   = proc_dointvec_jiffies,
 664         },
 665         {
 666                 .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 667                 .maxlen         = sizeof(unsigned int),
 668                 .mode           = 0644,
 669                 .proc_handler   = proc_dointvec_jiffies,
 670         },
 671         {
 672                 .procname       = "nf_conntrack_sctp_timeout_established",
 673                 .maxlen         = sizeof(unsigned int),
 674                 .mode           = 0644,
 675                 .proc_handler   = proc_dointvec_jiffies,
 676         },
 677         {
 678                 .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 679                 .maxlen         = sizeof(unsigned int),
 680                 .mode           = 0644,
 681                 .proc_handler   = proc_dointvec_jiffies,
 682         },
 683         {
 684                 .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 685                 .maxlen         = sizeof(unsigned int),
 686                 .mode           = 0644,
 687                 .proc_handler   = proc_dointvec_jiffies,
 688         },
 689         {
 690                 .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 691                 .maxlen         = sizeof(unsigned int),
 692                 .mode           = 0644,
 693                 .proc_handler   = proc_dointvec_jiffies,
 694         },
 695         {
 696                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_sent",
 697                 .maxlen         = sizeof(unsigned int),
 698                 .mode           = 0644,
 699                 .proc_handler   = proc_dointvec_jiffies,
 700         },
 701         {
 702                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_acked",
 703                 .maxlen         = sizeof(unsigned int),
 704                 .mode           = 0644,
 705                 .proc_handler   = proc_dointvec_jiffies,
 706         },
 707         { }
 708 };
 709 #endif
 710
 711 static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
 712                                      struct nf_sctp_net *sn)
 713 {
 714 #ifdef CONFIG_SYSCTL
 715         if (pn->ctl_table)
 716                 return 0;
 717
 718         pn->ctl_table = kmemdup(sctp_sysctl_table,
 719                                 sizeof(sctp_sysctl_table),
 720                                 GFP_KERNEL);
 721         if (!pn->ctl_table)
 722                 return -ENOMEM;
 723
 724         pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 725         pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 726         pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 727         pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 728         pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 729         pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 730         pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 731         pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
 732         pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
 733 #endif
 734         return 0;
 735 }
 736
 737 static int sctp_init_net(struct net *net)
 738 {
 739         struct nf_sctp_net *sn = sctp_pernet(net);
 740         struct nf_proto_net *pn = &sn->pn;
 741
 742         if (!pn->users) {
 743                 int i;
 744
 745                 for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 746                         sn->timeouts[i] = sctp_timeouts[i];
 747
 748                 /* timeouts[0] is unused, init it so ->timeouts[0] contains
 749                  * 'new' timeout, like udp or icmp.
 750                  */
 751                 sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED];
 752         }
 753
 754         return sctp_kmemdup_sysctl_table(pn, sn);
 755 }
 756
 757 static struct nf_proto_net *sctp_get_net_proto(struct net *net)
 758 {
 759         return &net->ct.nf_ct_proto.sctp.pn;
 760 }
 761
 762 const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = {
 763         .l4proto                = IPPROTO_SCTP,
 764 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 765         .print_conntrack        = sctp_print_conntrack,
 766 #endif
 767         .packet                 = sctp_packet,
 768         .can_early_drop         = sctp_can_early_drop,
 769         .me                     = THIS_MODULE,
 770 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 771         .nlattr_size            = SCTP_NLATTR_SIZE,
 772         .to_nlattr              = sctp_to_nlattr,
 773         .from_nlattr            = nlattr_to_sctp,
 774         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 775         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 776         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 777         .nla_policy             = nf_ct_port_nla_policy,
 778 #endif
 779 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 780         .ctnl_timeout           = {
 781                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 782                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 783                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 784                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 785                 .nla_policy     = sctp_timeout_nla_policy,
 786         },
 787 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 788         .init_net               = sctp_init_net,
 789         .get_net_proto          = sctp_get_net_proto,
 790 };