1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/spinlock.h>
4 #include <linux/sock_diag.h>
5 #include <linux/unix_diag.h>
6 #include <linux/skbuff.h>
7 #include <linux/module.h>
8 #include <linux/uidgid.h>
9 #include <net/netlink.h>
10 #include <net/af_unix.h>
11 #include <net/tcp_states.h>
12 #include <net/sock.h>
13
sk_diag_dump_name(struct sock * sk,struct sk_buff * nlskb)14 static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
15 {
16 /* might or might not have unix_table_lock */
17 struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);
18
19 if (!addr)
20 return 0;
21
22 return nla_put(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short),
23 addr->name->sun_path);
24 }
25
sk_diag_dump_vfs(struct sock * sk,struct sk_buff * nlskb)26 static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
27 {
28 struct dentry *dentry = unix_sk(sk)->path.dentry;
29
30 if (dentry) {
31 struct unix_diag_vfs uv = {
32 .udiag_vfs_ino = d_backing_inode(dentry)->i_ino,
33 .udiag_vfs_dev = dentry->d_sb->s_dev,
34 };
35
36 return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv);
37 }
38
39 return 0;
40 }
41
sk_diag_dump_peer(struct sock * sk,struct sk_buff * nlskb)42 static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
43 {
44 struct sock *peer;
45 int ino;
46
47 peer = unix_peer_get(sk);
48 if (peer) {
49 unix_state_lock(peer);
50 ino = sock_i_ino(peer);
51 unix_state_unlock(peer);
52 sock_put(peer);
53
54 return nla_put_u32(nlskb, UNIX_DIAG_PEER, ino);
55 }
56
57 return 0;
58 }
59
sk_diag_dump_icons(struct sock * sk,struct sk_buff * nlskb)60 static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
61 {
62 struct sk_buff *skb;
63 struct nlattr *attr;
64 u32 *buf;
65 int i;
66
67 if (sk->sk_state == TCP_LISTEN) {
68 spin_lock(&sk->sk_receive_queue.lock);
69
70 attr = nla_reserve(nlskb, UNIX_DIAG_ICONS,
71 sk->sk_receive_queue.qlen * sizeof(u32));
72 if (!attr)
73 goto errout;
74
75 buf = nla_data(attr);
76 i = 0;
77 skb_queue_walk(&sk->sk_receive_queue, skb) {
78 struct sock *req, *peer;
79
80 req = skb->sk;
81 /*
82 * The state lock is outer for the same sk's
83 * queue lock. With the other's queue locked it's
84 * OK to lock the state.
85 */
86 unix_state_lock_nested(req);
87 peer = unix_sk(req)->peer;
88 buf[i++] = (peer ? sock_i_ino(peer) : 0);
89 unix_state_unlock(req);
90 }
91 spin_unlock(&sk->sk_receive_queue.lock);
92 }
93
94 return 0;
95
96 errout:
97 spin_unlock(&sk->sk_receive_queue.lock);
98 return -EMSGSIZE;
99 }
100
sk_diag_show_rqlen(struct sock * sk,struct sk_buff * nlskb)101 static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
102 {
103 struct unix_diag_rqlen rql;
104
105 if (sk->sk_state == TCP_LISTEN) {
106 rql.udiag_rqueue = sk->sk_receive_queue.qlen;
107 rql.udiag_wqueue = sk->sk_max_ack_backlog;
108 } else {
109 rql.udiag_rqueue = (u32) unix_inq_len(sk);
110 rql.udiag_wqueue = (u32) unix_outq_len(sk);
111 }
112
113 return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
114 }
115
sk_diag_dump_uid(struct sock * sk,struct sk_buff * nlskb)116 static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb)
117 {
118 uid_t uid = from_kuid_munged(sk_user_ns(nlskb->sk), sock_i_uid(sk));
119 return nla_put(nlskb, UNIX_DIAG_UID, sizeof(uid_t), &uid);
120 }
121
sk_diag_fill(struct sock * sk,struct sk_buff * skb,struct unix_diag_req * req,u32 portid,u32 seq,u32 flags,int sk_ino)122 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
123 u32 portid, u32 seq, u32 flags, int sk_ino)
124 {
125 struct nlmsghdr *nlh;
126 struct unix_diag_msg *rep;
127
128 nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
129 flags);
130 if (!nlh)
131 return -EMSGSIZE;
132
133 rep = nlmsg_data(nlh);
134 rep->udiag_family = AF_UNIX;
135 rep->udiag_type = sk->sk_type;
136 rep->udiag_state = sk->sk_state;
137 rep->pad = 0;
138 rep->udiag_ino = sk_ino;
139 sock_diag_save_cookie(sk, rep->udiag_cookie);
140
141 if ((req->udiag_show & UDIAG_SHOW_NAME) &&
142 sk_diag_dump_name(sk, skb))
143 goto out_nlmsg_trim;
144
145 if ((req->udiag_show & UDIAG_SHOW_VFS) &&
146 sk_diag_dump_vfs(sk, skb))
147 goto out_nlmsg_trim;
148
149 if ((req->udiag_show & UDIAG_SHOW_PEER) &&
150 sk_diag_dump_peer(sk, skb))
151 goto out_nlmsg_trim;
152
153 if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
154 sk_diag_dump_icons(sk, skb))
155 goto out_nlmsg_trim;
156
157 if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
158 sk_diag_show_rqlen(sk, skb))
159 goto out_nlmsg_trim;
160
161 if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
162 sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
163 goto out_nlmsg_trim;
164
165 if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
166 goto out_nlmsg_trim;
167
168 if ((req->udiag_show & UDIAG_SHOW_UID) &&
169 sk_diag_dump_uid(sk, skb))
170 goto out_nlmsg_trim;
171
172 nlmsg_end(skb, nlh);
173 return 0;
174
175 out_nlmsg_trim:
176 nlmsg_cancel(skb, nlh);
177 return -EMSGSIZE;
178 }
179
sk_diag_dump(struct sock * sk,struct sk_buff * skb,struct unix_diag_req * req,u32 portid,u32 seq,u32 flags)180 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
181 u32 portid, u32 seq, u32 flags)
182 {
183 int sk_ino;
184
185 unix_state_lock(sk);
186 sk_ino = sock_i_ino(sk);
187 unix_state_unlock(sk);
188
189 if (!sk_ino)
190 return 0;
191
192 return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino);
193 }
194
unix_diag_dump(struct sk_buff * skb,struct netlink_callback * cb)195 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
196 {
197 struct unix_diag_req *req;
198 int num, s_num, slot, s_slot;
199 struct net *net = sock_net(skb->sk);
200
201 req = nlmsg_data(cb->nlh);
202
203 s_slot = cb->args[0];
204 num = s_num = cb->args[1];
205
206 spin_lock(&unix_table_lock);
207 for (slot = s_slot;
208 slot < ARRAY_SIZE(unix_socket_table);
209 s_num = 0, slot++) {
210 struct sock *sk;
211
212 num = 0;
213 sk_for_each(sk, &unix_socket_table[slot]) {
214 if (!net_eq(sock_net(sk), net))
215 continue;
216 if (num < s_num)
217 goto next;
218 if (!(req->udiag_states & (1 << sk->sk_state)))
219 goto next;
220 if (sk_diag_dump(sk, skb, req,
221 NETLINK_CB(cb->skb).portid,
222 cb->nlh->nlmsg_seq,
223 NLM_F_MULTI) < 0)
224 goto done;
225 next:
226 num++;
227 }
228 }
229 done:
230 spin_unlock(&unix_table_lock);
231 cb->args[0] = slot;
232 cb->args[1] = num;
233
234 return skb->len;
235 }
236
unix_lookup_by_ino(unsigned int ino)237 static struct sock *unix_lookup_by_ino(unsigned int ino)
238 {
239 int i;
240 struct sock *sk;
241
242 spin_lock(&unix_table_lock);
243 for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
244 sk_for_each(sk, &unix_socket_table[i])
245 if (ino == sock_i_ino(sk)) {
246 sock_hold(sk);
247 spin_unlock(&unix_table_lock);
248
249 return sk;
250 }
251 }
252
253 spin_unlock(&unix_table_lock);
254 return NULL;
255 }
256
unix_diag_get_exact(struct sk_buff * in_skb,const struct nlmsghdr * nlh,struct unix_diag_req * req)257 static int unix_diag_get_exact(struct sk_buff *in_skb,
258 const struct nlmsghdr *nlh,
259 struct unix_diag_req *req)
260 {
261 int err = -EINVAL;
262 struct sock *sk;
263 struct sk_buff *rep;
264 unsigned int extra_len;
265 struct net *net = sock_net(in_skb->sk);
266
267 if (req->udiag_ino == 0)
268 goto out_nosk;
269
270 sk = unix_lookup_by_ino(req->udiag_ino);
271 err = -ENOENT;
272 if (sk == NULL)
273 goto out_nosk;
274 if (!net_eq(sock_net(sk), net))
275 goto out;
276
277 err = sock_diag_check_cookie(sk, req->udiag_cookie);
278 if (err)
279 goto out;
280
281 extra_len = 256;
282 again:
283 err = -ENOMEM;
284 rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
285 if (!rep)
286 goto out;
287
288 err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid,
289 nlh->nlmsg_seq, 0, req->udiag_ino);
290 if (err < 0) {
291 nlmsg_free(rep);
292 extra_len += 256;
293 if (extra_len >= PAGE_SIZE)
294 goto out;
295
296 goto again;
297 }
298 err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
299 MSG_DONTWAIT);
300 if (err > 0)
301 err = 0;
302 out:
303 if (sk)
304 sock_put(sk);
305 out_nosk:
306 return err;
307 }
308
unix_diag_handler_dump(struct sk_buff * skb,struct nlmsghdr * h)309 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
310 {
311 int hdrlen = sizeof(struct unix_diag_req);
312 struct net *net = sock_net(skb->sk);
313
314 if (nlmsg_len(h) < hdrlen)
315 return -EINVAL;
316
317 if (h->nlmsg_flags & NLM_F_DUMP) {
318 struct netlink_dump_control c = {
319 .dump = unix_diag_dump,
320 };
321 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
322 } else
323 return unix_diag_get_exact(skb, h, nlmsg_data(h));
324 }
325
326 static const struct sock_diag_handler unix_diag_handler = {
327 .family = AF_UNIX,
328 .dump = unix_diag_handler_dump,
329 };
330
unix_diag_init(void)331 static int __init unix_diag_init(void)
332 {
333 return sock_diag_register(&unix_diag_handler);
334 }
335
unix_diag_exit(void)336 static void __exit unix_diag_exit(void)
337 {
338 sock_diag_unregister(&unix_diag_handler);
339 }
340
341 module_init(unix_diag_init);
342 module_exit(unix_diag_exit);
343 MODULE_LICENSE("GPL");
344 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);
345