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 #define UNIX_DIAG_PUT(skb, attrtype, attrlen) \
  12         RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
  13
  14 static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
  15 {
  16         struct unix_address *addr = unix_sk(sk)->addr;
  17         char *s;
  18
  19         if (addr) {
  20                 s = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short));
  21                 memcpy(s, addr->name->sun_path, addr->len - sizeof(short));
  22         }
  23
  24         return 0;
  25
  26 rtattr_failure:
  27         return -EMSGSIZE;
  28 }
  29
  30 static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
  31 {
  32         struct dentry *dentry = unix_sk(sk)->path.dentry;
  33         struct unix_diag_vfs *uv;
  34
  35         if (dentry) {
  36                 uv = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_VFS, sizeof(*uv));
  37                 uv->udiag_vfs_ino = dentry->d_inode->i_ino;
  38                 uv->udiag_vfs_dev = dentry->d_sb->s_dev;
  39         }
  40
  41         return 0;
  42
  43 rtattr_failure:
  44         return -EMSGSIZE;
  45 }
  46
  47 static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
  48 {
  49         struct sock *peer;
  50         int ino;
  51
  52         peer = unix_peer_get(sk);
  53         if (peer) {
  54                 unix_state_lock(peer);
  55                 ino = sock_i_ino(peer);
  56                 unix_state_unlock(peer);
  57                 sock_put(peer);
  58
  59                 RTA_PUT_U32(nlskb, UNIX_DIAG_PEER, ino);
  60         }
  61
  62         return 0;
  63 rtattr_failure:
  64         return -EMSGSIZE;
  65 }
  66
  67 static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
  68 {
  69         struct sk_buff *skb;
  70         u32 *buf;
  71         int i;
  72
  73         if (sk->sk_state == TCP_LISTEN) {
  74                 spin_lock(&sk->sk_receive_queue.lock);
  75                 buf = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_ICONS,
  76                                 sk->sk_receive_queue.qlen * sizeof(u32));
  77                 i = 0;
  78                 skb_queue_walk(&sk->sk_receive_queue, skb) {
  79                         struct sock *req, *peer;
  80
  81                         req = skb->sk;
  82                         /*
  83                          * The state lock is outer for the same sk's
  84                          * queue lock. With the other's queue locked it's
  85                          * OK to lock the state.
  86                          */
  87                         unix_state_lock_nested(req);
  88                         peer = unix_sk(req)->peer;
  89                         buf[i++] = (peer ? sock_i_ino(peer) : 0);
  90                         unix_state_unlock(req);
  91                 }
  92                 spin_unlock(&sk->sk_receive_queue.lock);
  93         }
  94
  95         return 0;
  96
  97 rtattr_failure:
  98         spin_unlock(&sk->sk_receive_queue.lock);
  99         return -EMSGSIZE;
 100 }
 101
 102 static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
 103 {
 104         struct unix_diag_rqlen *rql;
 105
 106         rql = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_RQLEN, sizeof(*rql));
 107
 108         if (sk->sk_state == TCP_LISTEN) {
 109                 rql->udiag_rqueue = sk->sk_receive_queue.qlen;
 110                 rql->udiag_wqueue = sk->sk_max_ack_backlog;
 111         } else {
 112                 rql->udiag_rqueue = (__u32)unix_inq_len(sk);
 113                 rql->udiag_wqueue = (__u32)unix_outq_len(sk);
 114         }
 115
 116         return 0;
 117
 118 rtattr_failure:
 119         return -EMSGSIZE;
 120 }
 121
 122 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 123                 u32 pid, u32 seq, u32 flags, int sk_ino)
 124 {
 125         unsigned char *b = skb_tail_pointer(skb);
 126         struct nlmsghdr *nlh;
 127         struct unix_diag_msg *rep;
 128
 129         nlh = NLMSG_PUT(skb, pid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep));
 130         nlh->nlmsg_flags = flags;
 131
 132         rep = NLMSG_DATA(nlh);
 133
 134         rep->udiag_family = AF_UNIX;
 135         rep->udiag_type = sk->sk_type;
 136         rep->udiag_state = sk->sk_state;
 137         rep->udiag_ino = sk_ino;
 138         sock_diag_save_cookie(sk, rep->udiag_cookie);
 139
 140         if ((req->udiag_show & UDIAG_SHOW_NAME) &&
 141             sk_diag_dump_name(sk, skb))
 142                 goto nlmsg_failure;
 143
 144         if ((req->udiag_show & UDIAG_SHOW_VFS) &&
 145             sk_diag_dump_vfs(sk, skb))
 146                 goto nlmsg_failure;
 147
 148         if ((req->udiag_show & UDIAG_SHOW_PEER) &&
 149             sk_diag_dump_peer(sk, skb))
 150                 goto nlmsg_failure;
 151
 152         if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
 153             sk_diag_dump_icons(sk, skb))
 154                 goto nlmsg_failure;
 155
 156         if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
 157             sk_diag_show_rqlen(sk, skb))
 158                 goto nlmsg_failure;
 159
 160         if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
 161             sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
 162                 goto nlmsg_failure;
 163
 164         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 165         return skb->len;
 166
 167 nlmsg_failure:
 168         nlmsg_trim(skb, b);
 169         return -EMSGSIZE;
 170 }
 171
 172 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 173                 u32 pid, u32 seq, u32 flags)
 174 {
 175         int sk_ino;
 176
 177         unix_state_lock(sk);
 178         sk_ino = sock_i_ino(sk);
 179         unix_state_unlock(sk);
 180
 181         if (!sk_ino)
 182                 return 0;
 183
 184         return sk_diag_fill(sk, skb, req, pid, seq, flags, sk_ino);
 185 }
 186
 187 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 188 {
 189         struct unix_diag_req *req;
 190         int num, s_num, slot, s_slot;
 191
 192         req = NLMSG_DATA(cb->nlh);
 193
 194         s_slot = cb->args[0];
 195         num = s_num = cb->args[1];
 196
 197         spin_lock(&unix_table_lock);
 198         for (slot = s_slot; slot <= UNIX_HASH_SIZE; s_num = 0, slot++) {
 199                 struct sock *sk;
 200                 struct hlist_node *node;
 201
 202                 num = 0;
 203                 sk_for_each(sk, node, &unix_socket_table[slot]) {
 204                         if (num < s_num)
 205                                 goto next;
 206                         if (!(req->udiag_states & (1 << sk->sk_state)))
 207                                 goto next;
 208                         if (sk_diag_dump(sk, skb, req,
 209                                          NETLINK_CB(cb->skb).pid,
 210                                          cb->nlh->nlmsg_seq,
 211                                          NLM_F_MULTI) < 0)
 212                                 goto done;
 213 next:
 214                         num++;
 215                 }
 216         }
 217 done:
 218         spin_unlock(&unix_table_lock);
 219         cb->args[0] = slot;
 220         cb->args[1] = num;
 221
 222         return skb->len;
 223 }
 224
 225 static struct sock *unix_lookup_by_ino(int ino)
 226 {
 227         int i;
 228         struct sock *sk;
 229
 230         spin_lock(&unix_table_lock);
 231         for (i = 0; i <= UNIX_HASH_SIZE; i++) {
 232                 struct hlist_node *node;
 233
 234                 sk_for_each(sk, node, &unix_socket_table[i])
 235                         if (ino == sock_i_ino(sk)) {
 236                                 sock_hold(sk);
 237                                 spin_unlock(&unix_table_lock);
 238
 239                                 return sk;
 240                         }
 241         }
 242
 243         spin_unlock(&unix_table_lock);
 244         return NULL;
 245 }
 246
 247 static int unix_diag_get_exact(struct sk_buff *in_skb,
 248                                const struct nlmsghdr *nlh,
 249                                struct unix_diag_req *req)
 250 {
 251         int err = -EINVAL;
 252         struct sock *sk;
 253         struct sk_buff *rep;
 254         unsigned int extra_len;
 255
 256         if (req->udiag_ino == 0)
 257                 goto out_nosk;
 258
 259         sk = unix_lookup_by_ino(req->udiag_ino);
 260         err = -ENOENT;
 261         if (sk == NULL)
 262                 goto out_nosk;
 263
 264         err = sock_diag_check_cookie(sk, req->udiag_cookie);
 265         if (err)
 266                 goto out;
 267
 268         extra_len = 256;
 269 again:
 270         err = -ENOMEM;
 271         rep = alloc_skb(NLMSG_SPACE((sizeof(struct unix_diag_msg) + extra_len)),
 272                         GFP_KERNEL);
 273         if (!rep)
 274                 goto out;
 275
 276         err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).pid,
 277                            nlh->nlmsg_seq, 0, req->udiag_ino);
 278         if (err < 0) {
 279                 kfree_skb(rep);
 280                 extra_len += 256;
 281                 if (extra_len >= PAGE_SIZE)
 282                         goto out;
 283
 284                 goto again;
 285         }
 286         err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
 287                               MSG_DONTWAIT);
 288         if (err > 0)
 289                 err = 0;
 290 out:
 291         if (sk)
 292                 sock_put(sk);
 293 out_nosk:
 294         return err;
 295 }
 296
 297 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 298 {
 299         int hdrlen = sizeof(struct unix_diag_req);
 300
 301         if (nlmsg_len(h) < hdrlen)
 302                 return -EINVAL;
 303
 304         if (h->nlmsg_flags & NLM_F_DUMP) {
 305                 struct netlink_dump_control c = {
 306                         .dump = unix_diag_dump,
 307                 };
 308                 return netlink_dump_start(sock_diag_nlsk, skb, h, &c);
 309         } else
 310                 return unix_diag_get_exact(skb, h, (struct unix_diag_req *)NLMSG_DATA(h));
 311 }
 312
 313 static const struct sock_diag_handler unix_diag_handler = {
 314         .family = AF_UNIX,
 315         .dump = unix_diag_handler_dump,
 316 };
 317
 318 static int __init unix_diag_init(void)
 319 {
 320         return sock_diag_register(&unix_diag_handler);
 321 }
 322
 323 static void __exit unix_diag_exit(void)
 324 {
 325         sock_diag_unregister(&unix_diag_handler);
 326 }
 327
 328 module_init(unix_diag_init);
 329 module_exit(unix_diag_exit);
 330 MODULE_LICENSE("GPL");
 331 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);