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)
  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);
  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                 sk = __udp4_lib_lookup(net,
  46                                 req->id.idiag_src[0], req->id.idiag_sport,
  47                                 req->id.idiag_dst[0], req->id.idiag_dport,
  48                                 req->id.idiag_if, tbl, NULL);
  49 #if IS_ENABLED(CONFIG_IPV6)
  50         else if (req->sdiag_family == AF_INET6)
  51                 sk = __udp6_lib_lookup(net,
  52                                 (struct in6_addr *)req->id.idiag_src,
  53                                 req->id.idiag_sport,
  54                                 (struct in6_addr *)req->id.idiag_dst,
  55                                 req->id.idiag_dport,
  56                                 req->id.idiag_if, tbl, NULL);
  57 #endif
  58         if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
  59                 sk = NULL;
  60         rcu_read_unlock();
  61         err = -ENOENT;
  62         if (!sk)
  63                 goto out_nosk;
  64
  65         err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
  66         if (err)
  67                 goto out;
  68
  69         err = -ENOMEM;
  70         rep = nlmsg_new(sizeof(struct inet_diag_msg) +
  71                         sizeof(struct inet_diag_meminfo) + 64,
  72                         GFP_KERNEL);
  73         if (!rep)
  74                 goto out;
  75
  76         err = inet_sk_diag_fill(sk, NULL, rep, req,
  77                            sk_user_ns(NETLINK_CB(in_skb).sk),
  78                            NETLINK_CB(in_skb).portid,
  79                            nlh->nlmsg_seq, 0, nlh);
  80         if (err < 0) {
  81                 WARN_ON(err == -EMSGSIZE);
  82                 kfree_skb(rep);
  83                 goto out;
  84         }
  85         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
  86                               MSG_DONTWAIT);
  87         if (err > 0)
  88                 err = 0;
  89 out:
  90         if (sk)
  91                 sock_put(sk);
  92 out_nosk:
  93         return err;
  94 }
  95
  96 static void udp_dump(struct udp_table *table, struct sk_buff *skb,
  97                      struct netlink_callback *cb,
  98                      const struct inet_diag_req_v2 *r, struct nlattr *bc)
  99 {
 100         struct net *net = sock_net(skb->sk);
 101         int num, s_num, slot, s_slot;
 102
 103         s_slot = cb->args[0];
 104         num = s_num = cb->args[1];
 105
 106         for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
 107                 struct udp_hslot *hslot = &table->hash[slot];
 108                 struct sock *sk;
 109
 110                 num = 0;
 111
 112                 if (hlist_empty(&hslot->head))
 113                         continue;
 114
 115                 spin_lock_bh(&hslot->lock);
 116                 sk_for_each(sk, &hslot->head) {
 117                         struct inet_sock *inet = inet_sk(sk);
 118
 119                         if (!net_eq(sock_net(sk), net))
 120                                 continue;
 121                         if (num < s_num)
 122                                 goto next;
 123                         if (!(r->idiag_states & (1 << sk->sk_state)))
 124                                 goto next;
 125                         if (r->sdiag_family != AF_UNSPEC &&
 126                                         sk->sk_family != r->sdiag_family)
 127                                 goto next;
 128                         if (r->id.idiag_sport != inet->inet_sport &&
 129                             r->id.idiag_sport)
 130                                 goto next;
 131                         if (r->id.idiag_dport != inet->inet_dport &&
 132                             r->id.idiag_dport)
 133                                 goto next;
 134
 135                         if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
 136                                 spin_unlock_bh(&hslot->lock);
 137                                 goto done;
 138                         }
 139 next:
 140                         num++;
 141                 }
 142                 spin_unlock_bh(&hslot->lock);
 143         }
 144 done:
 145         cb->args[0] = slot;
 146         cb->args[1] = num;
 147 }
 148
 149 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 150                           const struct inet_diag_req_v2 *r, struct nlattr *bc)
 151 {
 152         udp_dump(&udp_table, skb, cb, r, bc);
 153 }
 154
 155 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 156                              const struct inet_diag_req_v2 *req)
 157 {
 158         return udp_dump_one(&udp_table, in_skb, nlh, req);
 159 }
 160
 161 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 162                 void *info)
 163 {
 164         r->idiag_rqueue = sk_rmem_alloc_get(sk);
 165         r->idiag_wqueue = sk_wmem_alloc_get(sk);
 166 }
 167
 168 static const struct inet_diag_handler udp_diag_handler = {
 169         .dump            = udp_diag_dump,
 170         .dump_one        = udp_diag_dump_one,
 171         .idiag_get_info  = udp_diag_get_info,
 172         .idiag_type      = IPPROTO_UDP,
 173         .idiag_info_size = 0,
 174 };
 175
 176 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 177                               const struct inet_diag_req_v2 *r,
 178                               struct nlattr *bc)
 179 {
 180         udp_dump(&udplite_table, skb, cb, r, bc);
 181 }
 182
 183 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
 184                                  const struct inet_diag_req_v2 *req)
 185 {
 186         return udp_dump_one(&udplite_table, in_skb, nlh, req);
 187 }
 188
 189 static const struct inet_diag_handler udplite_diag_handler = {
 190         .dump            = udplite_diag_dump,
 191         .dump_one        = udplite_diag_dump_one,
 192         .idiag_get_info  = udp_diag_get_info,
 193         .idiag_type      = IPPROTO_UDPLITE,
 194         .idiag_info_size = 0,
 195 };
 196
 197 static int __init udp_diag_init(void)
 198 {
 199         int err;
 200
 201         err = inet_diag_register(&udp_diag_handler);
 202         if (err)
 203                 goto out;
 204         err = inet_diag_register(&udplite_diag_handler);
 205         if (err)
 206                 goto out_lite;
 207 out:
 208         return err;
 209 out_lite:
 210         inet_diag_unregister(&udp_diag_handler);
 211         goto out;
 212 }
 213
 214 static void __exit udp_diag_exit(void)
 215 {
 216         inet_diag_unregister(&udplite_diag_handler);
 217         inet_diag_unregister(&udp_diag_handler);
 218 }
 219
 220 module_init(udp_diag_init);
 221 module_exit(udp_diag_exit);
 222 MODULE_LICENSE("GPL");
 223 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 224 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);