net/ipv4/udp_diag.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * udp_diag.c   Module for monitoring UDP transport protocols sockets.
   4  *
   5  * Authors:     Pavel Emelyanov, <xemul@parallels.com>
   6  */
   7
   8
   9 #include <linux/module.h>
  10 #include <linux/inet_diag.h>
  11 #include <linux/udp.h>
  12 #include <net/udp.h>
  13 #include <net/udplite.h>
  14 #include <linux/sock_diag.h>
  15
  16 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
  17                         struct netlink_callback *cb,
  18                         const struct inet_diag_req_v2 *req,
  19                         struct nlattr *bc, bool net_admin)
  20 {
  21         if (!inet_diag_bc_sk(bc, sk))
  22                 return 0;
  23
  24         return inet_sk_diag_fill(sk, NULL, skb, req,
  25                         sk_user_ns(NETLINK_CB(cb->skb).sk),
  26                         NETLINK_CB(cb->skb).portid,
  27                         cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh, net_admin);
  28 }
  29
  30 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
  31                         const struct nlmsghdr *nlh,
  32                         const struct inet_diag_req_v2 *req)
  33 {
  34         int err = -EINVAL;
  35         struct sock *sk = NULL;
  36         struct sk_buff *rep;
  37         struct net *net = sock_net(in_skb->sk);
  38
  39         rcu_read_lock();
  40         if (req->sdiag_family == AF_INET)
  41                 /* src and dst are swapped for historical reasons */
  42                 sk = __udp4_lib_lookup(net,
  43                                 req->id.idiag_src[0], req->id.idiag_sport,
  44                                 req->id.idiag_dst[0], req->id.idiag_dport,
  45                                 req->id.idiag_if, 0, tbl, NULL);
  46 #if IS_ENABLED(CONFIG_IPV6)
  47         else if (req->sdiag_family == AF_INET6)
  48                 sk = __udp6_lib_lookup(net,
  49                                 (struct in6_addr *)req->id.idiag_src,
  50                                 req->id.idiag_sport,
  51                                 (struct in6_addr *)req->id.idiag_dst,
  52                                 req->id.idiag_dport,
  53                                 req->id.idiag_if, 0, tbl, NULL);
  54 #endif
  55         if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
  56                 sk = NULL;
  57         rcu_read_unlock();
  58         err = -ENOENT;
  59         if (!sk)
  60                 goto out_nosk;
  61
  62         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
  63         if (err)
  64                 goto out;
  65
  66         err = -ENOMEM;
  67         rep = nlmsg_new(sizeof(struct inet_diag_msg) +
  68                         sizeof(struct inet_diag_meminfo) + 64,
  69                         GFP_KERNEL);
  70         if (!rep)
  71                 goto out;
  72
  73         err = inet_sk_diag_fill(sk, NULL, rep, req,
  74                            sk_user_ns(NETLINK_CB(in_skb).sk),
  75                            NETLINK_CB(in_skb).portid,
  76                            nlh->nlmsg_seq, 0, nlh,
  77                            netlink_net_capable(in_skb, CAP_NET_ADMIN));
  78         if (err < 0) {
  79                 WARN_ON(err == -EMSGSIZE);
  80                 kfree_skb(rep);
  81                 goto out;
  82         }
  83         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
  84                               MSG_DONTWAIT);
  85         if (err > 0)
  86                 err = 0;
  87 out:
  88         if (sk)
  89                 sock_put(sk);
  90 out_nosk:
  91         return err;
  92 }
  93
  94 static void udp_dump(struct udp_table *table, struct sk_buff *skb,
  95                      struct netlink_callback *cb,
  96                      const struct inet_diag_req_v2 *r, struct nlattr *bc)
  97 {
  98         bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
  99         struct net *net = sock_net(skb->sk);
 100         int num, s_num, slot, s_slot;
 101
 102         s_slot = cb->args[0];
 103         num = s_num = cb->args[1];
 104
 105         for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
 106                 struct udp_hslot *hslot = &table->hash[slot];
 107                 struct sock *sk;
 108
 109                 num = 0;
 110
 111                 if (hlist_empty(&hslot->head))
 112                         continue;
 113
 114                 spin_lock_bh(&hslot->lock);
 115                 sk_for_each(sk, &hslot->head) {
 116                         struct inet_sock *inet = inet_sk(sk);
 117
 118                         if (!net_eq(sock_net(sk), net))
 119                                 continue;
 120                         if (num < s_num)
 121                                 goto next;
 122                         if (!(r->idiag_states & (1 << sk->sk_state)))
 123                                 goto next;
 124                         if (r->sdiag_family != AF_UNSPEC &&
 125                                         sk->sk_family != r->sdiag_family)
 126                                 goto next;
 127                         if (r->id.idiag_sport != inet->inet_sport &&
 128                             r->id.idiag_sport)
 129                                 goto next;
 130                         if (r->id.idiag_dport != inet->inet_dport &&
 131                             r->id.idiag_dport)
 132                                 goto next;
 133
 134                         if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
 135                                 spin_unlock_bh(&hslot->lock);
 136                                 goto done;
 137                         }
 138 next:
 139                         num++;
 140                 }
 141                 spin_unlock_bh(&hslot->lock);
 142         }
 143 done:
 144         cb->args[0] = slot;
 145         cb->args[1] = num;
 146 }
 147
 148 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 149                           const struct inet_diag_req_v2 *r, struct nlattr *bc)
 150 {
 151         udp_dump(&udp_table, skb, cb, r, bc);
 152 }
 153
 154 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 155                              const struct inet_diag_req_v2 *req)
 156 {
 157         return udp_dump_one(&udp_table, in_skb, nlh, req);
 158 }
 159
 160 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 161                 void *info)
 162 {
 163         r->idiag_rqueue = udp_rqueue_get(sk);
 164         r->idiag_wqueue = sk_wmem_alloc_get(sk);
 165 }
 166
 167 #ifdef CONFIG_INET_DIAG_DESTROY
 168 static int __udp_diag_destroy(struct sk_buff *in_skb,
 169                               const struct inet_diag_req_v2 *req,
 170                               struct udp_table *tbl)
 171 {
 172         struct net *net = sock_net(in_skb->sk);
 173         struct sock *sk;
 174         int err;
 175
 176         rcu_read_lock();
 177
 178         if (req->sdiag_family == AF_INET)
 179                 sk = __udp4_lib_lookup(net,
 180                                 req->id.idiag_dst[0], req->id.idiag_dport,
 181                                 req->id.idiag_src[0], req->id.idiag_sport,
 182                                 req->id.idiag_if, 0, tbl, NULL);
 183 #if IS_ENABLED(CONFIG_IPV6)
 184         else if (req->sdiag_family == AF_INET6) {
 185                 if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
 186                     ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
 187                         sk = __udp4_lib_lookup(net,
 188                                         req->id.idiag_dst[3], req->id.idiag_dport,
 189                                         req->id.idiag_src[3], req->id.idiag_sport,
 190                                         req->id.idiag_if, 0, tbl, NULL);
 191
 192                 else
 193                         sk = __udp6_lib_lookup(net,
 194                                         (struct in6_addr *)req->id.idiag_dst,
 195                                         req->id.idiag_dport,
 196                                         (struct in6_addr *)req->id.idiag_src,
 197                                         req->id.idiag_sport,
 198                                         req->id.idiag_if, 0, tbl, NULL);
 199         }
 200 #endif
 201         else {
 202                 rcu_read_unlock();
 203                 return -EINVAL;
 204         }
 205
 206         if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 207                 sk = NULL;
 208
 209         rcu_read_unlock();
 210
 211         if (!sk)
 212                 return -ENOENT;
 213
 214         if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
 215                 sock_put(sk);
 216                 return -ENOENT;
 217         }
 218
 219         err = sock_diag_destroy(sk, ECONNABORTED);
 220
 221         sock_put(sk);
 222
 223         return err;
 224 }
 225
 226 static int udp_diag_destroy(struct sk_buff *in_skb,
 227                             const struct inet_diag_req_v2 *req)
 228 {
 229         return __udp_diag_destroy(in_skb, req, &udp_table);
 230 }
 231
 232 static int udplite_diag_destroy(struct sk_buff *in_skb,
 233                                 const struct inet_diag_req_v2 *req)
 234 {
 235         return __udp_diag_destroy(in_skb, req, &udplite_table);
 236 }
 237
 238 #endif
 239
 240 static const struct inet_diag_handler udp_diag_handler = {
 241         .dump            = udp_diag_dump,
 242         .dump_one        = udp_diag_dump_one,
 243         .idiag_get_info  = udp_diag_get_info,
 244         .idiag_type      = IPPROTO_UDP,
 245         .idiag_info_size = 0,
 246 #ifdef CONFIG_INET_DIAG_DESTROY
 247         .destroy         = udp_diag_destroy,
 248 #endif
 249 };
 250
 251 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 252                               const struct inet_diag_req_v2 *r,
 253                               struct nlattr *bc)
 254 {
 255         udp_dump(&udplite_table, skb, cb, r, bc);
 256 }
 257
 258 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 259                                  const struct inet_diag_req_v2 *req)
 260 {
 261         return udp_dump_one(&udplite_table, in_skb, nlh, req);
 262 }
 263
 264 static const struct inet_diag_handler udplite_diag_handler = {
 265         .dump            = udplite_diag_dump,
 266         .dump_one        = udplite_diag_dump_one,
 267         .idiag_get_info  = udp_diag_get_info,
 268         .idiag_type      = IPPROTO_UDPLITE,
 269         .idiag_info_size = 0,
 270 #ifdef CONFIG_INET_DIAG_DESTROY
 271         .destroy         = udplite_diag_destroy,
 272 #endif
 273 };
 274
 275 static int __init udp_diag_init(void)
 276 {
 277         int err;
 278
 279         err = inet_diag_register(&udp_diag_handler);
 280         if (err)
 281                 goto out;
 282         err = inet_diag_register(&udplite_diag_handler);
 283         if (err)
 284                 goto out_lite;
 285 out:
 286         return err;
 287 out_lite:
 288         inet_diag_unregister(&udp_diag_handler);
 289         goto out;
 290 }
 291
 292 static void __exit udp_diag_exit(void)
 293 {
 294         inet_diag_unregister(&udplite_diag_handler);
 295         inet_diag_unregister(&udp_diag_handler);
 296 }
 297
 298 module_init(udp_diag_init);
 299 module_exit(udp_diag_exit);
 300 MODULE_LICENSE("GPL");
 301 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 302 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);