net/ipv4/udp_diag.c

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