summaryrefslogtreecommitdiffstats
path: root/net/unix/diag.c
blob: 3438b7af09af58187a7087f046eb10be3f8acb67 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/sock_diag.h>
#include <linux/unix_diag.h>
#include <linux/skbuff.h>
#include <linux/module.h>
#include <linux/uidgid.h>
#include <net/netlink.h>
#include <net/af_unix.h>
#include <net/tcp_states.h>
#include <net/sock.h>

static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
{
	/* might or might not have a hash table lock */
	struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);

	if (!addr)
		return 0;

	return nla_put(nlskb, UNIX_DIAG_NAME,
		       addr->len - offsetof(struct sockaddr_un, sun_path),
		       addr->name->sun_path);
}

static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
{
	struct dentry *dentry = unix_sk(sk)->path.dentry;

	if (dentry) {
		struct unix_diag_vfs uv = {
			.udiag_vfs_ino = d_backing_inode(dentry)->i_ino,
			.udiag_vfs_dev = dentry->d_sb->s_dev,
		};

		return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv);
	}

	return 0;
}

static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
{
	struct sock *peer;
	int ino;

	peer = unix_peer_get(sk);
	if (peer) {
		unix_state_lock(peer);
		ino = sock_i_ino(peer);
		unix_state_unlock(peer);
		sock_put(peer);

		return nla_put_u32(nlskb, UNIX_DIAG_PEER, ino);
	}

	return 0;
}

static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
{
	struct sk_buff *skb;
	struct nlattr *attr;
	u32 *buf;
	int i;

	if (sk->sk_state == TCP_LISTEN) {
		spin_lock(&sk->sk_receive_queue.lock);

		attr = nla_reserve(nlskb, UNIX_DIAG_ICONS,
				   sk->sk_receive_queue.qlen * sizeof(u32));
		if (!attr)
			goto errout;

		buf = nla_data(attr);
		i = 0;
		skb_queue_walk(&sk->sk_receive_queue, skb) {
			struct sock *req, *peer;

			req = skb->sk;
			/*
			 * The state lock is outer for the same sk's
			 * queue lock. With the other's queue locked it's
			 * OK to lock the state.
			 */
			unix_state_lock_nested(req, U_LOCK_DIAG);
			peer = unix_sk(req)->peer;
			buf[i++] = (peer ? sock_i_ino(peer) : 0);
			unix_state_unlock(req);
		}
		spin_unlock(&sk->sk_receive_queue.lock);
	}

	return 0;

errout:
	spin_unlock(&sk->sk_receive_queue.lock);
	return -EMSGSIZE;
}

static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
{
	struct unix_diag_rqlen rql;

	if (sk->sk_state == TCP_LISTEN) {
		rql.udiag_rqueue = sk->sk_receive_queue.qlen;
		rql.udiag_wqueue = sk->sk_max_ack_backlog;
	} else {
		rql.udiag_rqueue = (u32) unix_inq_len(sk);
		rql.udiag_wqueue = (u32) unix_outq_len(sk);
	}

	return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
}

static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb,
			    struct user_namespace *user_ns)
{
	uid_t uid = from_kuid_munged(user_ns, sock_i_uid(sk));
	return nla_put(nlskb, UNIX_DIAG_UID, sizeof(uid_t), &uid);
}

static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
			struct user_namespace *user_ns,
			u32 portid, u32 seq, u32 flags, int sk_ino)
{
	struct nlmsghdr *nlh;
	struct unix_diag_msg *rep;

	nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
			flags);
	if (!nlh)
		return -EMSGSIZE;

	rep = nlmsg_data(nlh);
	rep->udiag_family = AF_UNIX;
	rep->udiag_type = sk->sk_type;
	rep->udiag_state = sk->sk_state;
	rep->pad = 0;
	rep->udiag_ino = sk_ino;
	sock_diag_save_cookie(sk, rep->udiag_cookie);

	if ((req->udiag_show & UDIAG_SHOW_NAME) &&
	    sk_diag_dump_name(sk, skb))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_VFS) &&
	    sk_diag_dump_vfs(sk, skb))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_PEER) &&
	    sk_diag_dump_peer(sk, skb))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
	    sk_diag_dump_icons(sk, skb))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
	    sk_diag_show_rqlen(sk, skb))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
	    sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
		goto out_nlmsg_trim;

	if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
		goto out_nlmsg_trim;

	if ((req->udiag_show & UDIAG_SHOW_UID) &&
	    sk_diag_dump_uid(sk, skb, user_ns))
		goto out_nlmsg_trim;

	nlmsg_end(skb, nlh);
	return 0;

out_nlmsg_trim:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
			struct user_namespace *user_ns,
			u32 portid, u32 seq, u32 flags)
{
	int sk_ino;

	unix_state_lock(sk);
	sk_ino = sock_i_ino(sk);
	unix_state_unlock(sk);

	if (!sk_ino)
		return 0;

	return sk_diag_fill(sk, skb, req, user_ns, portid, seq, flags, sk_ino);
}

static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net *net = sock_net(skb->sk);
	int num, s_num, slot, s_slot;
	struct unix_diag_req *req;

	req = nlmsg_data(cb->nlh);

	s_slot = cb->args[0];
	num = s_num = cb->args[1];

	for (slot = s_slot; slot < UNIX_HASH_SIZE; s_num = 0, slot++) {
		struct sock *sk;

		num = 0;
		spin_lock(&net->unx.table.locks[slot]);
		sk_for_each(sk, &net->unx.table.buckets[slot]) {
			if (num < s_num)
				goto next;
			if (!(req->udiag_states & (1 << sk->sk_state)))
				goto next;
			if (sk_diag_dump(sk, skb, req, sk_user_ns(skb->sk),
					 NETLINK_CB(cb->skb).portid,
					 cb->nlh->nlmsg_seq,
					 NLM_F_MULTI) < 0) {
				spin_unlock(&net->unx.table.locks[slot]);
				goto done;
			}
next:
			num++;
		}
		spin_unlock(&net->unx.table.locks[slot]);
	}
done:
	cb->args[0] = slot;
	cb->args[1] = num;

	return skb->len;
}

static struct sock *unix_lookup_by_ino(struct net *net, unsigned int ino)
{
	struct sock *sk;
	int i;

	for (i = 0; i < UNIX_HASH_SIZE; i++) {
		spin_lock(&net->unx.table.locks[i]);
		sk_for_each(sk, &net->unx.table.buckets[i]) {
			if (ino == sock_i_ino(sk)) {
				sock_hold(sk);
				spin_unlock(&net->unx.table.locks[i]);
				return sk;
			}
		}
		spin_unlock(&net->unx.table.locks[i]);
	}
	return NULL;
}

static int unix_diag_get_exact(struct sk_buff *in_skb,
			       const struct nlmsghdr *nlh,
			       struct unix_diag_req *req)
{
	struct net *net = sock_net(in_skb->sk);
	unsigned int extra_len;
	struct sk_buff *rep;
	struct sock *sk;
	int err;

	err = -EINVAL;
	if (req->udiag_ino == 0)
		goto out_nosk;

	sk = unix_lookup_by_ino(net, req->udiag_ino);
	err = -ENOENT;
	if (sk == NULL)
		goto out_nosk;

	err = sock_diag_check_cookie(sk, req->udiag_cookie);
	if (err)
		goto out;

	extra_len = 256;
again:
	err = -ENOMEM;
	rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
	if (!rep)
		goto out;

	err = sk_diag_fill(sk, rep, req, sk_user_ns(NETLINK_CB(in_skb).sk),
			   NETLINK_CB(in_skb).portid,
			   nlh->nlmsg_seq, 0, req->udiag_ino);
	if (err < 0) {
		nlmsg_free(rep);
		extra_len += 256;
		if (extra_len >= PAGE_SIZE)
			goto out;

		goto again;
	}
	err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);

out:
	if (sk)
		sock_put(sk);
out_nosk:
	return err;
}

static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
{
	int hdrlen = sizeof(struct unix_diag_req);

	if (nlmsg_len(h) < hdrlen)
		return -EINVAL;

	if (h->nlmsg_flags & NLM_F_DUMP) {
		struct netlink_dump_control c = {
			.dump = unix_diag_dump,
		};
		return netlink_dump_start(sock_net(skb->sk)->diag_nlsk, skb, h, &c);
	} else
		return unix_diag_get_exact(skb, h, nlmsg_data(h));
}

static const struct sock_diag_handler unix_diag_handler = {
	.family = AF_UNIX,
	.dump = unix_diag_handler_dump,
};

static int __init unix_diag_init(void)
{
	return sock_diag_register(&unix_diag_handler);
}

static void __exit unix_diag_exit(void)
{
	sock_diag_unregister(&unix_diag_handler);
}

module_init(unix_diag_init);
module_exit(unix_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);