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         if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
 155                 goto out_nlmsg_trim;
 156
 157         return nlmsg_end(skb, nlh);
 158
 159 out_nlmsg_trim:
 160         nlmsg_cancel(skb, nlh);
 161         return -EMSGSIZE;
 162 }
 163
 164 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 165                 u32 portid, u32 seq, u32 flags)
 166 {
 167         int sk_ino;
 168
 169         unix_state_lock(sk);
 170         sk_ino = sock_i_ino(sk);
 171         unix_state_unlock(sk);
 172
 173         if (!sk_ino)
 174                 return 0;
 175
 176         return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino);
 177 }
 178
 179 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 180 {
 181         struct unix_diag_req *req;
 182         int num, s_num, slot, s_slot;
 183         struct net *net = sock_net(skb->sk);
 184
 185         req = nlmsg_data(cb->nlh);
 186
 187         s_slot = cb->args[0];
 188         num = s_num = cb->args[1];
 189
 190         spin_lock(&unix_table_lock);
 191         for (slot = s_slot;
 192              slot < ARRAY_SIZE(unix_socket_table);
 193              s_num = 0, slot++) {
 194                 struct sock *sk;
 195                 struct hlist_node *node;
 196
 197                 num = 0;
 198                 sk_for_each(sk, node, &unix_socket_table[slot]) {
 199                         if (!net_eq(sock_net(sk), net))
 200                                 continue;
 201                         if (num < s_num)
 202                                 goto next;
 203                         if (!(req->udiag_states & (1 << sk->sk_state)))
 204                                 goto next;
 205                         if (sk_diag_dump(sk, skb, req,
 206                                          NETLINK_CB(cb->skb).portid,
 207                                          cb->nlh->nlmsg_seq,
 208                                          NLM_F_MULTI) < 0)
 209                                 goto done;
 210 next:
 211                         num++;
 212                 }
 213         }
 214 done:
 215         spin_unlock(&unix_table_lock);
 216         cb->args[0] = slot;
 217         cb->args[1] = num;
 218
 219         return skb->len;
 220 }
 221
 222 static struct sock *unix_lookup_by_ino(int ino)
 223 {
 224         int i;
 225         struct sock *sk;
 226
 227         spin_lock(&unix_table_lock);
 228         for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
 229                 struct hlist_node *node;
 230
 231                 sk_for_each(sk, node, &unix_socket_table[i])
 232                         if (ino == sock_i_ino(sk)) {
 233                                 sock_hold(sk);
 234                                 spin_unlock(&unix_table_lock);
 235
 236                                 return sk;
 237                         }
 238         }
 239
 240         spin_unlock(&unix_table_lock);
 241         return NULL;
 242 }
 243
 244 static int unix_diag_get_exact(struct sk_buff *in_skb,
 245                                const struct nlmsghdr *nlh,
 246                                struct unix_diag_req *req)
 247 {
 248         int err = -EINVAL;
 249         struct sock *sk;
 250         struct sk_buff *rep;
 251         unsigned int extra_len;
 252         struct net *net = sock_net(in_skb->sk);
 253
 254         if (req->udiag_ino == 0)
 255                 goto out_nosk;
 256
 257         sk = unix_lookup_by_ino(req->udiag_ino);
 258         err = -ENOENT;
 259         if (sk == NULL)
 260                 goto out_nosk;
 261
 262         err = sock_diag_check_cookie(sk, req->udiag_cookie);
 263         if (err)
 264                 goto out;
 265
 266         extra_len = 256;
 267 again:
 268         err = -ENOMEM;
 269         rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
 270         if (!rep)
 271                 goto out;
 272
 273         err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid,
 274                            nlh->nlmsg_seq, 0, req->udiag_ino);
 275         if (err < 0) {
 276                 nlmsg_free(rep);
 277                 extra_len += 256;
 278                 if (extra_len >= PAGE_SIZE)
 279                         goto out;
 280
 281                 goto again;
 282         }
 283         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 284                               MSG_DONTWAIT);
 285         if (err > 0)
 286                 err = 0;
 287 out:
 288         if (sk)
 289                 sock_put(sk);
 290 out_nosk:
 291         return err;
 292 }
 293
 294 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 295 {
 296         int hdrlen = sizeof(struct unix_diag_req);
 297         struct net *net = sock_net(skb->sk);
 298
 299         if (nlmsg_len(h) < hdrlen)
 300                 return -EINVAL;
 301
 302         if (h->nlmsg_flags & NLM_F_DUMP) {
 303                 struct netlink_dump_control c = {
 304                         .dump = unix_diag_dump,
 305                 };
 306                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 307         } else
 308                 return unix_diag_get_exact(skb, h, nlmsg_data(h));
 309 }
 310
 311 static const struct sock_diag_handler unix_diag_handler = {
 312         .family = AF_UNIX,
 313         .dump = unix_diag_handler_dump,
 314 };
 315
 316 static int __init unix_diag_init(void)
 317 {
 318         return sock_diag_register(&unix_diag_handler);
 319 }
 320
 321 static void __exit unix_diag_exit(void)
 322 {
 323         sock_diag_unregister(&unix_diag_handler);
 324 }
 325
 326 module_init(unix_diag_init);
 327 module_exit(unix_diag_exit);
 328 MODULE_LICENSE("GPL");
 329 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);