net/unix/diag.c

   1 #include <linux/types.h>
   2 #include <linux/spinlock.h>
   3 #include <linux/sock_diag.h>
   4 #include <linux/unix_diag.h>
   5 #include <linux/skbuff.h>
   6 #include <linux/module.h>
   7 #include <net/netlink.h>
   8 #include <net/af_unix.h>
   9 #include <net/tcp_states.h>
  10
  11 static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
  12 {
  13         struct unix_address *addr = unix_sk(sk)->addr;
  14
  15         if (!addr)
  16                 return 0;
  17
  18         return nla_put(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short),
  19                        addr->name->sun_path);
  20 }
  21
  22 static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
  23 {
  24         struct dentry *dentry = unix_sk(sk)->path.dentry;
  25
  26         if (dentry) {
  27                 struct unix_diag_vfs uv = {
  28                         .udiag_vfs_ino = dentry->d_inode->i_ino,
  29                         .udiag_vfs_dev = dentry->d_sb->s_dev,
  30                 };
  31
  32                 return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv);
  33         }
  34
  35         return 0;
  36 }
  37
  38 static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
  39 {
  40         struct sock *peer;
  41         int ino;
  42
  43         peer = unix_peer_get(sk);
  44         if (peer) {
  45                 unix_state_lock(peer);
  46                 ino = sock_i_ino(peer);
  47                 unix_state_unlock(peer);
  48                 sock_put(peer);
  49
  50                 return nla_put_u32(nlskb, UNIX_DIAG_PEER, ino);
  51         }
  52
  53         return 0;
  54 }
  55
  56 static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
  57 {
  58         struct sk_buff *skb;
  59         struct nlattr *attr;
  60         u32 *buf;
  61         int i;
  62
  63         if (sk->sk_state == TCP_LISTEN) {
  64                 spin_lock(&sk->sk_receive_queue.lock);
  65
  66                 attr = nla_reserve(nlskb, UNIX_DIAG_ICONS,
  67                                    sk->sk_receive_queue.qlen * sizeof(u32));
  68                 if (!attr)
  69                         goto errout;
  70
  71                 buf = nla_data(attr);
  72                 i = 0;
  73                 skb_queue_walk(&sk->sk_receive_queue, skb) {
  74                         struct sock *req, *peer;
  75
  76                         req = skb->sk;
  77                         /*
  78                          * The state lock is outer for the same sk's
  79                          * queue lock. With the other's queue locked it's
  80                          * OK to lock the state.
  81                          */
  82                         unix_state_lock_nested(req);
  83                         peer = unix_sk(req)->peer;
  84                         buf[i++] = (peer ? sock_i_ino(peer) : 0);
  85                         unix_state_unlock(req);
  86                 }
  87                 spin_unlock(&sk->sk_receive_queue.lock);
  88         }
  89
  90         return 0;
  91
  92 errout:
  93         spin_unlock(&sk->sk_receive_queue.lock);
  94         return -EMSGSIZE;
  95 }
  96
  97 static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
  98 {
  99         struct unix_diag_rqlen rql;
 100
 101         if (sk->sk_state == TCP_LISTEN) {
 102                 rql.udiag_rqueue = sk->sk_receive_queue.qlen;
 103                 rql.udiag_wqueue = sk->sk_max_ack_backlog;
 104         } else {
 105                 rql.udiag_rqueue = (u32) unix_inq_len(sk);
 106                 rql.udiag_wqueue = (u32) unix_outq_len(sk);
 107         }
 108
 109         return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
 110 }
 111
 112 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 113                 u32 portid, u32 seq, u32 flags, int sk_ino)
 114 {
 115         struct nlmsghdr *nlh;
 116         struct unix_diag_msg *rep;
 117
 118         nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
 119                         flags);
 120         if (!nlh)
 121                 return -EMSGSIZE;
 122
 123         rep = nlmsg_data(nlh);
 124         rep->udiag_family = AF_UNIX;
 125         rep->udiag_type = sk->sk_type;
 126         rep->udiag_state = sk->sk_state;
 127         rep->udiag_ino = sk_ino;
 128         sock_diag_save_cookie(sk, rep->udiag_cookie);
 129
 130         if ((req->udiag_show & UDIAG_SHOW_NAME) &&
 131             sk_diag_dump_name(sk, skb))
 132                 goto out_nlmsg_trim;
 133
 134         if ((req->udiag_show & UDIAG_SHOW_VFS) &&
 135             sk_diag_dump_vfs(sk, skb))
 136                 goto out_nlmsg_trim;
 137
 138         if ((req->udiag_show & UDIAG_SHOW_PEER) &&
 139             sk_diag_dump_peer(sk, skb))
 140                 goto out_nlmsg_trim;
 141
 142         if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
 143             sk_diag_dump_icons(sk, skb))
 144                 goto out_nlmsg_trim;
 145
 146         if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
 147             sk_diag_show_rqlen(sk, skb))
 148                 goto out_nlmsg_trim;
 149
 150         if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
 151             sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
 152                 goto out_nlmsg_trim;
 153
 154         return nlmsg_end(skb, nlh);
 155
 156 out_nlmsg_trim:
 157         nlmsg_cancel(skb, nlh);
 158         return -EMSGSIZE;
 159 }
 160
 161 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 162                 u32 portid, u32 seq, u32 flags)
 163 {
 164         int sk_ino;
 165
 166         unix_state_lock(sk);
 167         sk_ino = sock_i_ino(sk);
 168         unix_state_unlock(sk);
 169
 170         if (!sk_ino)
 171                 return 0;
 172
 173         return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino);
 174 }
 175
 176 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 177 {
 178         struct unix_diag_req *req;
 179         int num, s_num, slot, s_slot;
 180         struct net *net = sock_net(skb->sk);
 181
 182         req = nlmsg_data(cb->nlh);
 183
 184         s_slot = cb->args[0];
 185         num = s_num = cb->args[1];
 186
 187         spin_lock(&unix_table_lock);
 188         for (slot = s_slot;
 189              slot < ARRAY_SIZE(unix_socket_table);
 190              s_num = 0, slot++) {
 191                 struct sock *sk;
 192                 struct hlist_node *node;
 193
 194                 num = 0;
 195                 sk_for_each(sk, node, &unix_socket_table[slot]) {
 196                         if (!net_eq(sock_net(sk), net))
 197                                 continue;
 198                         if (num < s_num)
 199                                 goto next;
 200                         if (!(req->udiag_states & (1 << sk->sk_state)))
 201                                 goto next;
 202                         if (sk_diag_dump(sk, skb, req,
 203                                          NETLINK_CB(cb->skb).portid,
 204                                          cb->nlh->nlmsg_seq,
 205                                          NLM_F_MULTI) < 0)
 206                                 goto done;
 207 next:
 208                         num++;
 209                 }
 210         }
 211 done:
 212         spin_unlock(&unix_table_lock);
 213         cb->args[0] = slot;
 214         cb->args[1] = num;
 215
 216         return skb->len;
 217 }
 218
 219 static struct sock *unix_lookup_by_ino(int ino)
 220 {
 221         int i;
 222         struct sock *sk;
 223
 224         spin_lock(&unix_table_lock);
 225         for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
 226                 struct hlist_node *node;
 227
 228                 sk_for_each(sk, node, &unix_socket_table[i])
 229                         if (ino == sock_i_ino(sk)) {
 230                                 sock_hold(sk);
 231                                 spin_unlock(&unix_table_lock);
 232
 233                                 return sk;
 234                         }
 235         }
 236
 237         spin_unlock(&unix_table_lock);
 238         return NULL;
 239 }
 240
 241 static int unix_diag_get_exact(struct sk_buff *in_skb,
 242                                const struct nlmsghdr *nlh,
 243                                struct unix_diag_req *req)
 244 {
 245         int err = -EINVAL;
 246         struct sock *sk;
 247         struct sk_buff *rep;
 248         unsigned int extra_len;
 249         struct net *net = sock_net(in_skb->sk);
 250
 251         if (req->udiag_ino == 0)
 252                 goto out_nosk;
 253
 254         sk = unix_lookup_by_ino(req->udiag_ino);
 255         err = -ENOENT;
 256         if (sk == NULL)
 257                 goto out_nosk;
 258
 259         err = sock_diag_check_cookie(sk, req->udiag_cookie);
 260         if (err)
 261                 goto out;
 262
 263         extra_len = 256;
 264 again:
 265         err = -ENOMEM;
 266         rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
 267         if (!rep)
 268                 goto out;
 269
 270         err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid,
 271                            nlh->nlmsg_seq, 0, req->udiag_ino);
 272         if (err < 0) {
 273                 nlmsg_free(rep);
 274                 extra_len += 256;
 275                 if (extra_len >= PAGE_SIZE)
 276                         goto out;
 277
 278                 goto again;
 279         }
 280         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 281                               MSG_DONTWAIT);
 282         if (err > 0)
 283                 err = 0;
 284 out:
 285         if (sk)
 286                 sock_put(sk);
 287 out_nosk:
 288         return err;
 289 }
 290
 291 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 292 {
 293         int hdrlen = sizeof(struct unix_diag_req);
 294         struct net *net = sock_net(skb->sk);
 295
 296         if (nlmsg_len(h) < hdrlen)
 297                 return -EINVAL;
 298
 299         if (h->nlmsg_flags & NLM_F_DUMP) {
 300                 struct netlink_dump_control c = {
 301                         .dump = unix_diag_dump,
 302                 };
 303                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 304         } else
 305                 return unix_diag_get_exact(skb, h, nlmsg_data(h));
 306 }
 307
 308 static const struct sock_diag_handler unix_diag_handler = {
 309         .family = AF_UNIX,
 310         .dump = unix_diag_handler_dump,
 311 };
 312
 313 static int __init unix_diag_init(void)
 314 {
 315         return sock_diag_register(&unix_diag_handler);
 316 }
 317
 318 static void __exit unix_diag_exit(void)
 319 {
 320         sock_diag_unregister(&unix_diag_handler);
 321 }
 322
 323 module_init(unix_diag_init);
 324 module_exit(unix_diag_exit);
 325 MODULE_LICENSE("GPL");
 326 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);