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, cb, req, NLM_F_MULTI,
  25                                  net_admin);
  26 }
  27
  28 static int udp_dump_one(struct udp_table *tbl,
  29                         struct netlink_callback *cb,
  30                         const struct inet_diag_req_v2 *req)
  31 {
  32         struct sk_buff *in_skb = cb->skb;
  33         int err;
  34         struct sock *sk = NULL;
  35         struct sk_buff *rep;
  36         struct net *net = sock_net(in_skb->sk);
  37
  38         rcu_read_lock();
  39         if (req->sdiag_family == AF_INET)
  40                 /* src and dst are swapped for historical reasons */
  41                 sk = __udp4_lib_lookup(net,
  42                                 req->id.idiag_src[0], req->id.idiag_sport,
  43                                 req->id.idiag_dst[0], req->id.idiag_dport,
  44                                 req->id.idiag_if, 0, tbl, NULL);
  45 #if IS_ENABLED(CONFIG_IPV6)
  46         else if (req->sdiag_family == AF_INET6)
  47                 sk = __udp6_lib_lookup(net,
  48                                 (struct in6_addr *)req->id.idiag_src,
  49                                 req->id.idiag_sport,
  50                                 (struct in6_addr *)req->id.idiag_dst,
  51                                 req->id.idiag_dport,
  52                                 req->id.idiag_if, 0, tbl, NULL);
  53 #endif
  54         if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
  55                 sk = NULL;
  56         rcu_read_unlock();
  57         err = -ENOENT;
  58         if (!sk)
  59                 goto out_nosk;
  60
  61         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
  62         if (err)
  63                 goto out;
  64
  65         err = -ENOMEM;
  66         rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
  67                         inet_diag_msg_attrs_size() +
  68                         nla_total_size(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, cb, req, 0,
  74                                 netlink_net_capable(in_skb, CAP_NET_ADMIN));
  75         if (err < 0) {
  76                 WARN_ON(err == -EMSGSIZE);
  77                 kfree_skb(rep);
  78                 goto out;
  79         }
  80         err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
  81
  82 out:
  83         if (sk)
  84                 sock_put(sk);
  85 out_nosk:
  86         return err;
  87 }
  88
  89 static void udp_dump(struct udp_table *table, struct sk_buff *skb,
  90                      struct netlink_callback *cb,
  91                      const struct inet_diag_req_v2 *r)
  92 {
  93         bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
  94         struct net *net = sock_net(skb->sk);
  95         struct inet_diag_dump_data *cb_data;
  96         int num, s_num, slot, s_slot;
  97         struct nlattr *bc;
  98
  99         cb_data = cb->data;
 100         bc = cb_data->inet_diag_nla_bc;
 101         s_slot = cb->args[0];
 102         num = s_num = cb->args[1];
 103
 104         for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
 105                 struct udp_hslot *hslot = &table->hash[slot];
 106                 struct sock *sk;
 107
 108                 num = 0;
 109
 110                 if (hlist_empty(&hslot->head))
 111                         continue;
 112
 113                 spin_lock_bh(&hslot->lock);
 114                 sk_for_each(sk, &hslot->head) {
 115                         struct inet_sock *inet = inet_sk(sk);
 116
 117                         if (!net_eq(sock_net(sk), net))
 118                                 continue;
 119                         if (num < s_num)
 120                                 goto next;
 121                         if (!(r->idiag_states & (1 << sk->sk_state)))
 122                                 goto next;
 123                         if (r->sdiag_family != AF_UNSPEC &&
 124                                         sk->sk_family != r->sdiag_family)
 125                                 goto next;
 126                         if (r->id.idiag_sport != inet->inet_sport &&
 127                             r->id.idiag_sport)
 128                                 goto next;
 129                         if (r->id.idiag_dport != inet->inet_dport &&
 130                             r->id.idiag_dport)
 131                                 goto next;
 132
 133                         if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
 134                                 spin_unlock_bh(&hslot->lock);
 135                                 goto done;
 136                         }
 137 next:
 138                         num++;
 139                 }
 140                 spin_unlock_bh(&hslot->lock);
 141         }
 142 done:
 143         cb->args[0] = slot;
 144         cb->args[1] = num;
 145 }
 146
 147 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 148                           const struct inet_diag_req_v2 *r)
 149 {
 150         udp_dump(sock_net(cb->skb->sk)->ipv4.udp_table, skb, cb, r);
 151 }
 152
 153 static int udp_diag_dump_one(struct netlink_callback *cb,
 154                              const struct inet_diag_req_v2 *req)
 155 {
 156         return udp_dump_one(sock_net(cb->skb->sk)->ipv4.udp_table, cb, req);
 157 }
 158
 159 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 160                 void *info)
 161 {
 162         r->idiag_rqueue = udp_rqueue_get(sk);
 163         r->idiag_wqueue = sk_wmem_alloc_get(sk);
 164 }
 165
 166 #ifdef CONFIG_INET_DIAG_DESTROY
 167 static int __udp_diag_destroy(struct sk_buff *in_skb,
 168                               const struct inet_diag_req_v2 *req,
 169                               struct udp_table *tbl)
 170 {
 171         struct net *net = sock_net(in_skb->sk);
 172         struct sock *sk;
 173         int err;
 174
 175         rcu_read_lock();
 176
 177         if (req->sdiag_family == AF_INET)
 178                 sk = __udp4_lib_lookup(net,
 179                                 req->id.idiag_dst[0], req->id.idiag_dport,
 180                                 req->id.idiag_src[0], req->id.idiag_sport,
 181                                 req->id.idiag_if, 0, tbl, NULL);
 182 #if IS_ENABLED(CONFIG_IPV6)
 183         else if (req->sdiag_family == AF_INET6) {
 184                 if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
 185                     ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
 186                         sk = __udp4_lib_lookup(net,
 187                                         req->id.idiag_dst[3], req->id.idiag_dport,
 188                                         req->id.idiag_src[3], req->id.idiag_sport,
 189                                         req->id.idiag_if, 0, tbl, NULL);
 190
 191                 else
 192                         sk = __udp6_lib_lookup(net,
 193                                         (struct in6_addr *)req->id.idiag_dst,
 194                                         req->id.idiag_dport,
 195                                         (struct in6_addr *)req->id.idiag_src,
 196                                         req->id.idiag_sport,
 197                                         req->id.idiag_if, 0, tbl, NULL);
 198         }
 199 #endif
 200         else {
 201                 rcu_read_unlock();
 202                 return -EINVAL;
 203         }
 204
 205         if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 206                 sk = NULL;
 207
 208         rcu_read_unlock();
 209
 210         if (!sk)
 211                 return -ENOENT;
 212
 213         if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
 214                 sock_put(sk);
 215                 return -ENOENT;
 216         }
 217
 218         err = sock_diag_destroy(sk, ECONNABORTED);
 219
 220         sock_put(sk);
 221
 222         return err;
 223 }
 224
 225 static int udp_diag_destroy(struct sk_buff *in_skb,
 226                             const struct inet_diag_req_v2 *req)
 227 {
 228         return __udp_diag_destroy(in_skb, req, sock_net(in_skb->sk)->ipv4.udp_table);
 229 }
 230
 231 static int udplite_diag_destroy(struct sk_buff *in_skb,
 232                                 const struct inet_diag_req_v2 *req)
 233 {
 234         return __udp_diag_destroy(in_skb, req, &udplite_table);
 235 }
 236
 237 #endif
 238
 239 static const struct inet_diag_handler udp_diag_handler = {
 240         .owner           = THIS_MODULE,
 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 {
 254         udp_dump(&udplite_table, skb, cb, r);
 255 }
 256
 257 static int udplite_diag_dump_one(struct netlink_callback *cb,
 258                                  const struct inet_diag_req_v2 *req)
 259 {
 260         return udp_dump_one(&udplite_table, cb, req);
 261 }
 262
 263 static const struct inet_diag_handler udplite_diag_handler = {
 264         .owner           = THIS_MODULE,
 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_DESCRIPTION("UDP socket monitoring via SOCK_DIAG");
 302 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 303 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);