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
sk_diag_dump_name(struct sock * sk,struct sk_buff * nlskb)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
sk_diag_dump_vfs(struct sock * sk,struct sk_buff * nlskb)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
sk_diag_dump_peer(struct sock * sk,struct sk_buff * nlskb)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
sk_diag_dump_icons(struct sock * sk,struct sk_buff * nlskb)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
sk_diag_show_rqlen(struct sock * sk,struct sk_buff * nlskb)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
sk_diag_fill(struct sock * sk,struct sk_buff * skb,struct unix_diag_req * req,u32 portid,u32 seq,u32 flags,int sk_ino)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
sk_diag_dump(struct sock * sk,struct sk_buff * skb,struct unix_diag_req * req,u32 portid,u32 seq,u32 flags)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
unix_diag_dump(struct sk_buff * skb,struct netlink_callback * cb)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
unix_lookup_by_ino(unsigned int ino)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
unix_diag_get_exact(struct sk_buff * in_skb,const struct nlmsghdr * nlh,struct unix_diag_req * req)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
unix_diag_handler_dump(struct sk_buff * skb,struct nlmsghdr * h)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
unix_diag_init(void)317 static int __init unix_diag_init(void)
318 {
319 return sock_diag_register(&unix_diag_handler);
320 }
321
unix_diag_exit(void)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 */);
331