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