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 = d_backing_inode(dentry)->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->pad = 0;
 128         rep->udiag_ino = sk_ino;
 129         sock_diag_save_cookie(sk, rep->udiag_cookie);
 130
 131         if ((req->udiag_show & UDIAG_SHOW_NAME) &&
 132             sk_diag_dump_name(sk, skb))
 133                 goto out_nlmsg_trim;
 134
 135         if ((req->udiag_show & UDIAG_SHOW_VFS) &&
 136             sk_diag_dump_vfs(sk, skb))
 137                 goto out_nlmsg_trim;
 138
 139         if ((req->udiag_show & UDIAG_SHOW_PEER) &&
 140             sk_diag_dump_peer(sk, skb))
 141                 goto out_nlmsg_trim;
 142
 143         if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
 144             sk_diag_dump_icons(sk, skb))
 145                 goto out_nlmsg_trim;
 146
 147         if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
 148             sk_diag_show_rqlen(sk, skb))
 149                 goto out_nlmsg_trim;
 150
 151         if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
 152             sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
 153                 goto out_nlmsg_trim;
 154
 155         if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
 156                 goto out_nlmsg_trim;
 157
 158         nlmsg_end(skb, nlh);
 159         return 0;
 160
 161 out_nlmsg_trim:
 162         nlmsg_cancel(skb, nlh);
 163         return -EMSGSIZE;
 164 }
 165
 166 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 167                 u32 portid, u32 seq, u32 flags)
 168 {
 169         int sk_ino;
 170
 171         unix_state_lock(sk);
 172         sk_ino = sock_i_ino(sk);
 173         unix_state_unlock(sk);
 174
 175         if (!sk_ino)
 176                 return 0;
 177
 178         return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino);
 179 }
 180
 181 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 182 {
 183         struct unix_diag_req *req;
 184         int num, s_num, slot, s_slot;
 185         struct net *net = sock_net(skb->sk);
 186
 187         req = nlmsg_data(cb->nlh);
 188
 189         s_slot = cb->args[0];
 190         num = s_num = cb->args[1];
 191
 192         spin_lock(&unix_table_lock);
 193         for (slot = s_slot;
 194              slot < ARRAY_SIZE(unix_socket_table);
 195              s_num = 0, slot++) {
 196                 struct sock *sk;
 197
 198                 num = 0;
 199                 sk_for_each(sk, &unix_socket_table[slot]) {
 200                         if (!net_eq(sock_net(sk), net))
 201                                 continue;
 202                         if (num < s_num)
 203                                 goto next;
 204                         if (!(req->udiag_states & (1 << sk->sk_state)))
 205                                 goto next;
 206                         if (sk_diag_dump(sk, skb, req,
 207                                          NETLINK_CB(cb->skb).portid,
 208                                          cb->nlh->nlmsg_seq,
 209                                          NLM_F_MULTI) < 0)
 210                                 goto done;
 211 next:
 212                         num++;
 213                 }
 214         }
 215 done:
 216         spin_unlock(&unix_table_lock);
 217         cb->args[0] = slot;
 218         cb->args[1] = num;
 219
 220         return skb->len;
 221 }
 222
 223 static struct sock *unix_lookup_by_ino(unsigned int ino)
 224 {
 225         int i;
 226         struct sock *sk;
 227
 228         spin_lock(&unix_table_lock);
 229         for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
 230                 sk_for_each(sk, &unix_socket_table[i])
 231                         if (ino == sock_i_ino(sk)) {
 232                                 sock_hold(sk);
 233                                 spin_unlock(&unix_table_lock);
 234
 235                                 return sk;
 236                         }
 237         }
 238
 239         spin_unlock(&unix_table_lock);
 240         return NULL;
 241 }
 242
 243 static int unix_diag_get_exact(struct sk_buff *in_skb,
 244                                const struct nlmsghdr *nlh,
 245                                struct unix_diag_req *req)
 246 {
 247         int err = -EINVAL;
 248         struct sock *sk;
 249         struct sk_buff *rep;
 250         unsigned int extra_len;
 251         struct net *net = sock_net(in_skb->sk);
 252
 253         if (req->udiag_ino == 0)
 254                 goto out_nosk;
 255
 256         sk = unix_lookup_by_ino(req->udiag_ino);
 257         err = -ENOENT;
 258         if (sk == NULL)
 259                 goto out_nosk;
 260         if (!net_eq(sock_net(sk), net))
 261                 goto out;
 262
 263         err = sock_diag_check_cookie(sk, req->udiag_cookie);
 264         if (err)
 265                 goto out;
 266
 267         extra_len = 256;
 268 again:
 269         err = -ENOMEM;
 270         rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
 271         if (!rep)
 272                 goto out;
 273
 274         err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid,
 275                            nlh->nlmsg_seq, 0, req->udiag_ino);
 276         if (err < 0) {
 277                 nlmsg_free(rep);
 278                 extra_len += 256;
 279                 if (extra_len >= PAGE_SIZE)
 280                         goto out;
 281
 282                 goto again;
 283         }
 284         err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 285                               MSG_DONTWAIT);
 286         if (err > 0)
 287                 err = 0;
 288 out:
 289         if (sk)
 290                 sock_put(sk);
 291 out_nosk:
 292         return err;
 293 }
 294
 295 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 296 {
 297         int hdrlen = sizeof(struct unix_diag_req);
 298         struct net *net = sock_net(skb->sk);
 299
 300         if (nlmsg_len(h) < hdrlen)
 301                 return -EINVAL;
 302
 303         if (h->nlmsg_flags & NLM_F_DUMP) {
 304                 struct netlink_dump_control c = {
 305                         .dump = unix_diag_dump,
 306                 };
 307                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 308         } else
 309                 return unix_diag_get_exact(skb, h, nlmsg_data(h));
 310 }
 311
 312 static const struct sock_diag_handler unix_diag_handler = {
 313         .family = AF_UNIX,
 314         .dump = unix_diag_handler_dump,
 315 };
 316
 317 static int __init unix_diag_init(void)
 318 {
 319         return sock_diag_register(&unix_diag_handler);
 320 }
 321
 322 static void __exit unix_diag_exit(void)
 323 {
 324         sock_diag_unregister(&unix_diag_handler);
 325 }
 326
 327 module_init(unix_diag_init);
 328 module_exit(unix_diag_exit);
 329 MODULE_LICENSE("GPL");
 330 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);