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, struct inet_diag_req_v2 *req,
  22                 struct nlattr *bc)
  23 {
  24         if (!inet_diag_bc_sk(bc, sk))
  25                 return 0;
  26
  27         return inet_sk_diag_fill(sk, NULL, skb, req,
  28                         sk_user_ns(NETLINK_CB(cb->skb).ssk),
  29                         NETLINK_CB(cb->skb).portid,
  30                         cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
  31 }
  32
  33 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
  34                 const struct nlmsghdr *nlh, struct inet_diag_req_v2 *req)
  35 {
  36         int err = -EINVAL;
  37         struct sock *sk;
  38         struct sk_buff *rep;
  39         struct net *net = sock_net(in_skb->sk);
  40
  41         if (req->sdiag_family == AF_INET)
  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, tbl);
  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, tbl);
  54 #endif
  55         else
  56                 goto out_nosk;
  57
  58         err = -ENOENT;
  59         if (sk == NULL)
  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 = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
  68                                      sizeof(struct inet_diag_meminfo) +
  69                                      64)), 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).ssk),
  75                            NETLINK_CB(in_skb).portid,
  76                            nlh->nlmsg_seq, 0, nlh);
  77         if (err < 0) {
  78                 WARN_ON(err == -EMSGSIZE);
  79                 kfree_skb(rep);
  80                 goto out;
  81         }
  82         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
  83                               MSG_DONTWAIT);
  84         if (err > 0)
  85                 err = 0;
  86 out:
  87         if (sk)
  88                 sock_put(sk);
  89 out_nosk:
  90         return err;
  91 }
  92
  93 static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb,
  94                 struct inet_diag_req_v2 *r, struct nlattr *bc)
  95 {
  96         int num, s_num, slot, s_slot;
  97         struct net *net = sock_net(skb->sk);
  98
  99         s_slot = cb->args[0];
 100         num = s_num = cb->args[1];
 101
 102         for (slot = s_slot; slot <= table->mask; num = s_num = 0, slot++) {
 103                 struct sock *sk;
 104                 struct hlist_nulls_node *node;
 105                 struct udp_hslot *hslot = &table->hash[slot];
 106
 107                 if (hlist_nulls_empty(&hslot->head))
 108                         continue;
 109
 110                 spin_lock_bh(&hslot->lock);
 111                 sk_nulls_for_each(sk, node, &hslot->head) {
 112                         struct inet_sock *inet = inet_sk(sk);
 113
 114                         if (!net_eq(sock_net(sk), net))
 115                                 continue;
 116                         if (num < s_num)
 117                                 goto next;
 118                         if (!(r->idiag_states & (1 << sk->sk_state)))
 119                                 goto next;
 120                         if (r->sdiag_family != AF_UNSPEC &&
 121                                         sk->sk_family != r->sdiag_family)
 122                                 goto next;
 123                         if (r->id.idiag_sport != inet->inet_sport &&
 124                             r->id.idiag_sport)
 125                                 goto next;
 126                         if (r->id.idiag_dport != inet->inet_dport &&
 127                             r->id.idiag_dport)
 128                                 goto next;
 129
 130                         if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
 131                                 spin_unlock_bh(&hslot->lock);
 132                                 goto done;
 133                         }
 134 next:
 135                         num++;
 136                 }
 137                 spin_unlock_bh(&hslot->lock);
 138         }
 139 done:
 140         cb->args[0] = slot;
 141         cb->args[1] = num;
 142 }
 143
 144 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 145                 struct inet_diag_req_v2 *r, struct nlattr *bc)
 146 {
 147         udp_dump(&udp_table, skb, cb, r, bc);
 148 }
 149
 150 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 151                 struct inet_diag_req_v2 *req)
 152 {
 153         return udp_dump_one(&udp_table, in_skb, nlh, req);
 154 }
 155
 156 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 157                 void *info)
 158 {
 159         r->idiag_rqueue = sk_rmem_alloc_get(sk);
 160         r->idiag_wqueue = sk_wmem_alloc_get(sk);
 161 }
 162
 163 static const struct inet_diag_handler udp_diag_handler = {
 164         .dump            = udp_diag_dump,
 165         .dump_one        = udp_diag_dump_one,
 166         .idiag_get_info  = udp_diag_get_info,
 167         .idiag_type      = IPPROTO_UDP,
 168 };
 169
 170 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 171                 struct inet_diag_req_v2 *r, struct nlattr *bc)
 172 {
 173         udp_dump(&udplite_table, skb, cb, r, bc);
 174 }
 175
 176 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 177                 struct inet_diag_req_v2 *req)
 178 {
 179         return udp_dump_one(&udplite_table, in_skb, nlh, req);
 180 }
 181
 182 static const struct inet_diag_handler udplite_diag_handler = {
 183         .dump            = udplite_diag_dump,
 184         .dump_one        = udplite_diag_dump_one,
 185         .idiag_get_info  = udp_diag_get_info,
 186         .idiag_type      = IPPROTO_UDPLITE,
 187 };
 188
 189 static int __init udp_diag_init(void)
 190 {
 191         int err;
 192
 193         err = inet_diag_register(&udp_diag_handler);
 194         if (err)
 195                 goto out;
 196         err = inet_diag_register(&udplite_diag_handler);
 197         if (err)
 198                 goto out_lite;
 199 out:
 200         return err;
 201 out_lite:
 202         inet_diag_unregister(&udp_diag_handler);
 203         goto out;
 204 }
 205
 206 static void __exit udp_diag_exit(void)
 207 {
 208         inet_diag_unregister(&udplite_diag_handler);
 209         inet_diag_unregister(&udp_diag_handler);
 210 }
 211
 212 module_init(udp_diag_init);
 213 module_exit(udp_diag_exit);
 214 MODULE_LICENSE("GPL");
 215 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 216 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);