linux/net/unix/diag.c
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   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
  11static 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
  22static 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
  38static 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
  56static 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
  92errout:
  93        spin_unlock(&sk->sk_receive_queue.lock);
  94        return -EMSGSIZE;
  95}
  96
  97static 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
 112static 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        return nlmsg_end(skb, nlh);
 159
 160out_nlmsg_trim:
 161        nlmsg_cancel(skb, nlh);
 162        return -EMSGSIZE;
 163}
 164
 165static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
 166                u32 portid, u32 seq, u32 flags)
 167{
 168        int sk_ino;
 169
 170        unix_state_lock(sk);
 171        sk_ino = sock_i_ino(sk);
 172        unix_state_unlock(sk);
 173
 174        if (!sk_ino)
 175                return 0;
 176
 177        return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino);
 178}
 179
 180static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 181{
 182        struct unix_diag_req *req;
 183        int num, s_num, slot, s_slot;
 184        struct net *net = sock_net(skb->sk);
 185
 186        req = nlmsg_data(cb->nlh);
 187
 188        s_slot = cb->args[0];
 189        num = s_num = cb->args[1];
 190
 191        spin_lock(&unix_table_lock);
 192        for (slot = s_slot;
 193             slot < ARRAY_SIZE(unix_socket_table);
 194             s_num = 0, slot++) {
 195                struct sock *sk;
 196
 197                num = 0;
 198                sk_for_each(sk, &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;
 210next:
 211                        num++;
 212                }
 213        }
 214done:
 215        spin_unlock(&unix_table_lock);
 216        cb->args[0] = slot;
 217        cb->args[1] = num;
 218
 219        return skb->len;
 220}
 221
 222static 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                sk_for_each(sk, &unix_socket_table[i])
 230                        if (ino == sock_i_ino(sk)) {
 231                                sock_hold(sk);
 232                                spin_unlock(&unix_table_lock);
 233
 234                                return sk;
 235                        }
 236        }
 237
 238        spin_unlock(&unix_table_lock);
 239        return NULL;
 240}
 241
 242static int unix_diag_get_exact(struct sk_buff *in_skb,
 243                               const struct nlmsghdr *nlh,
 244                               struct unix_diag_req *req)
 245{
 246        int err = -EINVAL;
 247        struct sock *sk;
 248        struct sk_buff *rep;
 249        unsigned int extra_len;
 250        struct net *net = sock_net(in_skb->sk);
 251
 252        if (req->udiag_ino == 0)
 253                goto out_nosk;
 254
 255        sk = unix_lookup_by_ino(req->udiag_ino);
 256        err = -ENOENT;
 257        if (sk == NULL)
 258                goto out_nosk;
 259
 260        err = sock_diag_check_cookie(sk, req->udiag_cookie);
 261        if (err)
 262                goto out;
 263
 264        extra_len = 256;
 265again:
 266        err = -ENOMEM;
 267        rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
 268        if (!rep)
 269                goto out;
 270
 271        err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid,
 272                           nlh->nlmsg_seq, 0, req->udiag_ino);
 273        if (err < 0) {
 274                nlmsg_free(rep);
 275                extra_len += 256;
 276                if (extra_len >= PAGE_SIZE)
 277                        goto out;
 278
 279                goto again;
 280        }
 281        err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 282                              MSG_DONTWAIT);
 283        if (err > 0)
 284                err = 0;
 285out:
 286        if (sk)
 287                sock_put(sk);
 288out_nosk:
 289        return err;
 290}
 291
 292static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 293{
 294        int hdrlen = sizeof(struct unix_diag_req);
 295        struct net *net = sock_net(skb->sk);
 296
 297        if (nlmsg_len(h) < hdrlen)
 298                return -EINVAL;
 299
 300        if (h->nlmsg_flags & NLM_F_DUMP) {
 301                struct netlink_dump_control c = {
 302                        .dump = unix_diag_dump,
 303                };
 304                return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 305        } else
 306                return unix_diag_get_exact(skb, h, nlmsg_data(h));
 307}
 308
 309static const struct sock_diag_handler unix_diag_handler = {
 310        .family = AF_UNIX,
 311        .dump = unix_diag_handler_dump,
 312};
 313
 314static int __init unix_diag_init(void)
 315{
 316        return sock_diag_register(&unix_diag_handler);
 317}
 318
 319static void __exit unix_diag_exit(void)
 320{
 321        sock_diag_unregister(&unix_diag_handler);
 322}
 323
 324module_init(unix_diag_init);
 325module_exit(unix_diag_exit);
 326MODULE_LICENSE("GPL");
 327MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);
 328