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
 14static 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
 26rtattr_failure:
 27	return -EMSGSIZE;
 28}
 29
 30static 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
 43rtattr_failure:
 44	return -EMSGSIZE;
 45}
 46
 47static 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;
 63rtattr_failure:
 64	return -EMSGSIZE;
 65}
 66
 67static 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
 97rtattr_failure:
 98	spin_unlock(&sk->sk_receive_queue.lock);
 99	return -EMSGSIZE;
100}
101
102static 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
118rtattr_failure:
119	return -EMSGSIZE;
120}
121
122static 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
167nlmsg_failure:
168	nlmsg_trim(skb, b);
169	return -EMSGSIZE;
170}
171
172static 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
187static 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;
213next:
214			num++;
215		}
216	}
217done:
218	spin_unlock(&unix_table_lock);
219	cb->args[0] = slot;
220	cb->args[1] = num;
221
222	return skb->len;
223}
224
225static 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
247static 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;
269again:
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;
290out:
291	if (sk)
292		sock_put(sk);
293out_nosk:
294	return err;
295}
296
297static 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
313static const struct sock_diag_handler unix_diag_handler = {
314	.family = AF_UNIX,
315	.dump = unix_diag_handler_dump,
316};
317
318static int __init unix_diag_init(void)
319{
320	return sock_diag_register(&unix_diag_handler);
321}
322
323static void __exit unix_diag_exit(void)
324{
325	sock_diag_unregister(&unix_diag_handler);
326}
327
328module_init(unix_diag_init);
329module_exit(unix_diag_exit);
330MODULE_LICENSE("GPL");
331MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);