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/inet_diag.h>
  19 #include <linux/sock_diag.h>
  20
  21 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
  22                 struct netlink_callback *cb, struct inet_diag_req_v2 *req,
  23                 struct nlattr *bc)
  24 {
  25         if (!inet_diag_bc_sk(bc, sk))
  26                 return 0;
  27
  28         return inet_sk_diag_fill(sk, NULL, skb, req, NETLINK_CB(cb->skb).pid,
  29                         cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
  30 }
  31
  32 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
  33                 const struct nlmsghdr *nlh, struct inet_diag_req_v2 *req)
  34 {
  35         int err = -EINVAL;
  36         struct sock *sk;
  37         struct sk_buff *rep;
  38
  39         if (req->sdiag_family == AF_INET)
  40                 sk = __udp4_lib_lookup(&init_net,
  41                                 req->id.idiag_src[0], req->id.idiag_sport,
  42                                 req->id.idiag_dst[0], req->id.idiag_dport,
  43                                 req->id.idiag_if, tbl);
  44 #if IS_ENABLED(CONFIG_IPV6)
  45         else if (req->sdiag_family == AF_INET6)
  46                 sk = __udp6_lib_lookup(&init_net,
  47                                 (struct in6_addr *)req->id.idiag_src,
  48                                 req->id.idiag_sport,
  49                                 (struct in6_addr *)req->id.idiag_dst,
  50                                 req->id.idiag_dport,
  51                                 req->id.idiag_if, tbl);
  52 #endif
  53         else
  54                 goto out_nosk;
  55
  56         err = -ENOENT;
  57         if (sk == NULL)
  58                 goto out_nosk;
  59
  60         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
  61         if (err)
  62                 goto out;
  63
  64         err = -ENOMEM;
  65         rep = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
  66                                      sizeof(struct inet_diag_meminfo) +
  67                                      64)), GFP_KERNEL);
  68         if (!rep)
  69                 goto out;
  70
  71         err = inet_sk_diag_fill(sk, NULL, rep, req,
  72                            NETLINK_CB(in_skb).pid,
  73                            nlh->nlmsg_seq, 0, nlh);
  74         if (err < 0) {
  75                 WARN_ON(err == -EMSGSIZE);
  76                 kfree_skb(rep);
  77                 goto out;
  78         }
  79         err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
  80                               MSG_DONTWAIT);
  81         if (err > 0)
  82                 err = 0;
  83 out:
  84         if (sk)
  85                 sock_put(sk);
  86 out_nosk:
  87         return err;
  88 }
  89
  90 static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb,
  91                 struct inet_diag_req_v2 *r, struct nlattr *bc)
  92 {
  93         int num, s_num, slot, s_slot;
  94
  95         s_slot = cb->args[0];
  96         num = s_num = cb->args[1];
  97
  98         for (slot = s_slot; slot <= table->mask; num = s_num = 0, slot++) {
  99                 struct sock *sk;
 100                 struct hlist_nulls_node *node;
 101                 struct udp_hslot *hslot = &table->hash[slot];
 102
 103                 if (hlist_nulls_empty(&hslot->head))
 104                         continue;
 105
 106                 spin_lock_bh(&hslot->lock);
 107                 sk_nulls_for_each(sk, node, &hslot->head) {
 108                         struct inet_sock *inet = inet_sk(sk);
 109
 110                         if (num < s_num)
 111                                 goto next;
 112                         if (!(r->idiag_states & (1 << sk->sk_state)))
 113                                 goto next;
 114                         if (r->sdiag_family != AF_UNSPEC &&
 115                                         sk->sk_family != r->sdiag_family)
 116                                 goto next;
 117                         if (r->id.idiag_sport != inet->inet_sport &&
 118                             r->id.idiag_sport)
 119                                 goto next;
 120                         if (r->id.idiag_dport != inet->inet_dport &&
 121                             r->id.idiag_dport)
 122                                 goto next;
 123
 124                         if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
 125                                 spin_unlock_bh(&hslot->lock);
 126                                 goto done;
 127                         }
 128 next:
 129                         num++;
 130                 }
 131                 spin_unlock_bh(&hslot->lock);
 132         }
 133 done:
 134         cb->args[0] = slot;
 135         cb->args[1] = num;
 136 }
 137
 138 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 139                 struct inet_diag_req_v2 *r, struct nlattr *bc)
 140 {
 141         udp_dump(&udp_table, skb, cb, r, bc);
 142 }
 143
 144 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 145                 struct inet_diag_req_v2 *req)
 146 {
 147         return udp_dump_one(&udp_table, in_skb, nlh, req);
 148 }
 149
 150 static const struct inet_diag_handler udp_diag_handler = {
 151         .dump            = udp_diag_dump,
 152         .dump_one        = udp_diag_dump_one,
 153         .idiag_type      = IPPROTO_UDP,
 154 };
 155
 156 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 157                 struct inet_diag_req_v2 *r, struct nlattr *bc)
 158 {
 159         udp_dump(&udplite_table, skb, cb, r, bc);
 160 }
 161
 162 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 163                 struct inet_diag_req_v2 *req)
 164 {
 165         return udp_dump_one(&udplite_table, in_skb, nlh, req);
 166 }
 167
 168 static const struct inet_diag_handler udplite_diag_handler = {
 169         .dump            = udplite_diag_dump,
 170         .dump_one        = udplite_diag_dump_one,
 171         .idiag_type      = IPPROTO_UDPLITE,
 172 };
 173
 174 static int __init udp_diag_init(void)
 175 {
 176         int err;
 177
 178         err = inet_diag_register(&udp_diag_handler);
 179         if (err)
 180                 goto out;
 181         err = inet_diag_register(&udplite_diag_handler);
 182         if (err)
 183                 goto out_lite;
 184 out:
 185         return err;
 186 out_lite:
 187         inet_diag_unregister(&udp_diag_handler);
 188         goto out;
 189 }
 190
 191 static void __exit udp_diag_exit(void)
 192 {
 193         inet_diag_unregister(&udplite_diag_handler);
 194         inet_diag_unregister(&udp_diag_handler);
 195 }
 196
 197 module_init(udp_diag_init);
 198 module_exit(udp_diag_exit);
 199 MODULE_LICENSE("GPL");
 200 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 201 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);