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Commit | Line | Data |
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3f421baa ACM |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Support for INET connection oriented protocols. | |
7 | * | |
8 | * Authors: See the TCP sources | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or(at your option) any later version. | |
14 | */ | |
15 | ||
3f421baa ACM |
16 | #include <linux/module.h> |
17 | #include <linux/jhash.h> | |
18 | ||
19 | #include <net/inet_connection_sock.h> | |
20 | #include <net/inet_hashtables.h> | |
21 | #include <net/inet_timewait_sock.h> | |
22 | #include <net/ip.h> | |
23 | #include <net/route.h> | |
24 | #include <net/tcp_states.h> | |
a019d6fe | 25 | #include <net/xfrm.h> |
3f421baa ACM |
26 | |
27 | #ifdef INET_CSK_DEBUG | |
28 | const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n"; | |
29 | EXPORT_SYMBOL(inet_csk_timer_bug_msg); | |
30 | #endif | |
31 | ||
32 | /* | |
3c689b73 | 33 | * This struct holds the first and last local port number. |
3f421baa | 34 | */ |
3c689b73 | 35 | struct local_ports sysctl_local_ports __read_mostly = { |
c4dbe54e | 36 | .lock = __SEQLOCK_UNLOCKED(sysctl_local_ports.lock), |
3c689b73 ED |
37 | .range = { 32768, 61000 }, |
38 | }; | |
227b60f5 | 39 | |
e3826f1e AW |
40 | unsigned long *sysctl_local_reserved_ports; |
41 | EXPORT_SYMBOL(sysctl_local_reserved_ports); | |
42 | ||
227b60f5 SH |
43 | void inet_get_local_port_range(int *low, int *high) |
44 | { | |
95c96174 ED |
45 | unsigned int seq; |
46 | ||
227b60f5 | 47 | do { |
3c689b73 | 48 | seq = read_seqbegin(&sysctl_local_ports.lock); |
227b60f5 | 49 | |
3c689b73 ED |
50 | *low = sysctl_local_ports.range[0]; |
51 | *high = sysctl_local_ports.range[1]; | |
52 | } while (read_seqretry(&sysctl_local_ports.lock, seq)); | |
227b60f5 SH |
53 | } |
54 | EXPORT_SYMBOL(inet_get_local_port_range); | |
3f421baa | 55 | |
971af18b | 56 | int inet_csk_bind_conflict(const struct sock *sk, |
aacd9289 | 57 | const struct inet_bind_bucket *tb, bool relax) |
3f421baa | 58 | { |
3f421baa ACM |
59 | struct sock *sk2; |
60 | struct hlist_node *node; | |
61 | int reuse = sk->sk_reuse; | |
da5e3630 TH |
62 | int reuseport = sk->sk_reuseport; |
63 | kuid_t uid = sock_i_uid((struct sock *)sk); | |
3f421baa | 64 | |
7477fd2e PE |
65 | /* |
66 | * Unlike other sk lookup places we do not check | |
67 | * for sk_net here, since _all_ the socks listed | |
68 | * in tb->owners list belong to the same net - the | |
69 | * one this bucket belongs to. | |
70 | */ | |
71 | ||
3f421baa ACM |
72 | sk_for_each_bound(sk2, node, &tb->owners) { |
73 | if (sk != sk2 && | |
74 | !inet_v6_ipv6only(sk2) && | |
75 | (!sk->sk_bound_dev_if || | |
76 | !sk2->sk_bound_dev_if || | |
77 | sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { | |
da5e3630 TH |
78 | if ((!reuse || !sk2->sk_reuse || |
79 | sk2->sk_state == TCP_LISTEN) && | |
80 | (!reuseport || !sk2->sk_reuseport || | |
81 | (sk2->sk_state != TCP_TIME_WAIT && | |
82 | !uid_eq(uid, sock_i_uid(sk2))))) { | |
68835aba ED |
83 | const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); |
84 | if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || | |
85 | sk2_rcv_saddr == sk_rcv_saddr(sk)) | |
3f421baa | 86 | break; |
8d238b25 | 87 | } |
aacd9289 AC |
88 | if (!relax && reuse && sk2->sk_reuse && |
89 | sk2->sk_state != TCP_LISTEN) { | |
90 | const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2); | |
91 | ||
92 | if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) || | |
93 | sk2_rcv_saddr == sk_rcv_saddr(sk)) | |
94 | break; | |
95 | } | |
3f421baa ACM |
96 | } |
97 | } | |
98 | return node != NULL; | |
99 | } | |
971af18b ACM |
100 | EXPORT_SYMBOL_GPL(inet_csk_bind_conflict); |
101 | ||
3f421baa ACM |
102 | /* Obtain a reference to a local port for the given sock, |
103 | * if snum is zero it means select any available local port. | |
104 | */ | |
ab1e0a13 | 105 | int inet_csk_get_port(struct sock *sk, unsigned short snum) |
3f421baa | 106 | { |
39d8cda7 | 107 | struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; |
3f421baa ACM |
108 | struct inet_bind_hashbucket *head; |
109 | struct hlist_node *node; | |
110 | struct inet_bind_bucket *tb; | |
a9d8f911 | 111 | int ret, attempts = 5; |
3b1e0a65 | 112 | struct net *net = sock_net(sk); |
a9d8f911 | 113 | int smallest_size = -1, smallest_rover; |
da5e3630 | 114 | kuid_t uid = sock_i_uid(sk); |
3f421baa ACM |
115 | |
116 | local_bh_disable(); | |
117 | if (!snum) { | |
227b60f5 SH |
118 | int remaining, rover, low, high; |
119 | ||
a9d8f911 | 120 | again: |
227b60f5 | 121 | inet_get_local_port_range(&low, &high); |
a25de534 | 122 | remaining = (high - low) + 1; |
a9d8f911 | 123 | smallest_rover = rover = net_random() % remaining + low; |
3f421baa | 124 | |
a9d8f911 | 125 | smallest_size = -1; |
3f421baa | 126 | do { |
e3826f1e AW |
127 | if (inet_is_reserved_local_port(rover)) |
128 | goto next_nolock; | |
7f635ab7 PE |
129 | head = &hashinfo->bhash[inet_bhashfn(net, rover, |
130 | hashinfo->bhash_size)]; | |
3f421baa ACM |
131 | spin_lock(&head->lock); |
132 | inet_bind_bucket_for_each(tb, node, &head->chain) | |
09ad9bc7 | 133 | if (net_eq(ib_net(tb), net) && tb->port == rover) { |
da5e3630 TH |
134 | if (((tb->fastreuse > 0 && |
135 | sk->sk_reuse && | |
136 | sk->sk_state != TCP_LISTEN) || | |
137 | (tb->fastreuseport > 0 && | |
138 | sk->sk_reuseport && | |
139 | uid_eq(tb->fastuid, uid))) && | |
a9d8f911 EP |
140 | (tb->num_owners < smallest_size || smallest_size == -1)) { |
141 | smallest_size = tb->num_owners; | |
142 | smallest_rover = rover; | |
aacd9289 AC |
143 | if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 && |
144 | !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { | |
8d238b25 | 145 | snum = smallest_rover; |
fddb7b57 | 146 | goto tb_found; |
a9d8f911 EP |
147 | } |
148 | } | |
aacd9289 | 149 | if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, false)) { |
2b05ad33 | 150 | snum = rover; |
fddb7b57 | 151 | goto tb_found; |
2b05ad33 | 152 | } |
3f421baa | 153 | goto next; |
a9d8f911 | 154 | } |
3f421baa ACM |
155 | break; |
156 | next: | |
157 | spin_unlock(&head->lock); | |
e3826f1e | 158 | next_nolock: |
6df71634 SH |
159 | if (++rover > high) |
160 | rover = low; | |
3f421baa | 161 | } while (--remaining > 0); |
3f421baa ACM |
162 | |
163 | /* Exhausted local port range during search? It is not | |
164 | * possible for us to be holding one of the bind hash | |
165 | * locks if this test triggers, because if 'remaining' | |
166 | * drops to zero, we broke out of the do/while loop at | |
167 | * the top level, not from the 'break;' statement. | |
168 | */ | |
169 | ret = 1; | |
a9d8f911 EP |
170 | if (remaining <= 0) { |
171 | if (smallest_size != -1) { | |
172 | snum = smallest_rover; | |
173 | goto have_snum; | |
174 | } | |
3f421baa | 175 | goto fail; |
a9d8f911 | 176 | } |
3f421baa ACM |
177 | /* OK, here is the one we will use. HEAD is |
178 | * non-NULL and we hold it's mutex. | |
179 | */ | |
180 | snum = rover; | |
181 | } else { | |
a9d8f911 | 182 | have_snum: |
7f635ab7 PE |
183 | head = &hashinfo->bhash[inet_bhashfn(net, snum, |
184 | hashinfo->bhash_size)]; | |
3f421baa ACM |
185 | spin_lock(&head->lock); |
186 | inet_bind_bucket_for_each(tb, node, &head->chain) | |
09ad9bc7 | 187 | if (net_eq(ib_net(tb), net) && tb->port == snum) |
3f421baa ACM |
188 | goto tb_found; |
189 | } | |
190 | tb = NULL; | |
191 | goto tb_not_found; | |
192 | tb_found: | |
193 | if (!hlist_empty(&tb->owners)) { | |
4a17fd52 PE |
194 | if (sk->sk_reuse == SK_FORCE_REUSE) |
195 | goto success; | |
196 | ||
da5e3630 TH |
197 | if (((tb->fastreuse > 0 && |
198 | sk->sk_reuse && sk->sk_state != TCP_LISTEN) || | |
199 | (tb->fastreuseport > 0 && | |
200 | sk->sk_reuseport && uid_eq(tb->fastuid, uid))) && | |
a9d8f911 | 201 | smallest_size == -1) { |
3f421baa ACM |
202 | goto success; |
203 | } else { | |
204 | ret = 1; | |
aacd9289 | 205 | if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb, true)) { |
da5e3630 | 206 | if (((sk->sk_reuse && sk->sk_state != TCP_LISTEN) || |
9c5e0c0b TH |
207 | (tb->fastreuseport > 0 && |
208 | sk->sk_reuseport && uid_eq(tb->fastuid, uid))) && | |
5add3009 | 209 | smallest_size != -1 && --attempts >= 0) { |
a9d8f911 EP |
210 | spin_unlock(&head->lock); |
211 | goto again; | |
212 | } | |
aacd9289 | 213 | |
3f421baa | 214 | goto fail_unlock; |
a9d8f911 | 215 | } |
3f421baa ACM |
216 | } |
217 | } | |
218 | tb_not_found: | |
219 | ret = 1; | |
941b1d22 PE |
220 | if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep, |
221 | net, head, snum)) == NULL) | |
3f421baa ACM |
222 | goto fail_unlock; |
223 | if (hlist_empty(&tb->owners)) { | |
224 | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN) | |
225 | tb->fastreuse = 1; | |
226 | else | |
227 | tb->fastreuse = 0; | |
da5e3630 TH |
228 | if (sk->sk_reuseport) { |
229 | tb->fastreuseport = 1; | |
230 | tb->fastuid = uid; | |
9c5e0c0b | 231 | } else |
da5e3630 | 232 | tb->fastreuseport = 0; |
da5e3630 TH |
233 | } else { |
234 | if (tb->fastreuse && | |
235 | (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) | |
236 | tb->fastreuse = 0; | |
237 | if (tb->fastreuseport && | |
9c5e0c0b | 238 | (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))) |
da5e3630 | 239 | tb->fastreuseport = 0; |
da5e3630 | 240 | } |
3f421baa ACM |
241 | success: |
242 | if (!inet_csk(sk)->icsk_bind_hash) | |
243 | inet_bind_hash(sk, tb, snum); | |
547b792c | 244 | WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); |
e905a9ed | 245 | ret = 0; |
3f421baa ACM |
246 | |
247 | fail_unlock: | |
248 | spin_unlock(&head->lock); | |
249 | fail: | |
250 | local_bh_enable(); | |
251 | return ret; | |
252 | } | |
3f421baa ACM |
253 | EXPORT_SYMBOL_GPL(inet_csk_get_port); |
254 | ||
255 | /* | |
256 | * Wait for an incoming connection, avoid race conditions. This must be called | |
257 | * with the socket locked. | |
258 | */ | |
259 | static int inet_csk_wait_for_connect(struct sock *sk, long timeo) | |
260 | { | |
261 | struct inet_connection_sock *icsk = inet_csk(sk); | |
262 | DEFINE_WAIT(wait); | |
263 | int err; | |
264 | ||
265 | /* | |
266 | * True wake-one mechanism for incoming connections: only | |
267 | * one process gets woken up, not the 'whole herd'. | |
268 | * Since we do not 'race & poll' for established sockets | |
269 | * anymore, the common case will execute the loop only once. | |
270 | * | |
271 | * Subtle issue: "add_wait_queue_exclusive()" will be added | |
272 | * after any current non-exclusive waiters, and we know that | |
273 | * it will always _stay_ after any new non-exclusive waiters | |
274 | * because all non-exclusive waiters are added at the | |
275 | * beginning of the wait-queue. As such, it's ok to "drop" | |
276 | * our exclusiveness temporarily when we get woken up without | |
277 | * having to remove and re-insert us on the wait queue. | |
278 | */ | |
279 | for (;;) { | |
aa395145 | 280 | prepare_to_wait_exclusive(sk_sleep(sk), &wait, |
3f421baa ACM |
281 | TASK_INTERRUPTIBLE); |
282 | release_sock(sk); | |
283 | if (reqsk_queue_empty(&icsk->icsk_accept_queue)) | |
284 | timeo = schedule_timeout(timeo); | |
285 | lock_sock(sk); | |
286 | err = 0; | |
287 | if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) | |
288 | break; | |
289 | err = -EINVAL; | |
290 | if (sk->sk_state != TCP_LISTEN) | |
291 | break; | |
292 | err = sock_intr_errno(timeo); | |
293 | if (signal_pending(current)) | |
294 | break; | |
295 | err = -EAGAIN; | |
296 | if (!timeo) | |
297 | break; | |
298 | } | |
aa395145 | 299 | finish_wait(sk_sleep(sk), &wait); |
3f421baa ACM |
300 | return err; |
301 | } | |
302 | ||
303 | /* | |
304 | * This will accept the next outstanding connection. | |
305 | */ | |
306 | struct sock *inet_csk_accept(struct sock *sk, int flags, int *err) | |
307 | { | |
308 | struct inet_connection_sock *icsk = inet_csk(sk); | |
8336886f | 309 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; |
3f421baa | 310 | struct sock *newsk; |
8336886f | 311 | struct request_sock *req; |
3f421baa ACM |
312 | int error; |
313 | ||
314 | lock_sock(sk); | |
315 | ||
316 | /* We need to make sure that this socket is listening, | |
317 | * and that it has something pending. | |
318 | */ | |
319 | error = -EINVAL; | |
320 | if (sk->sk_state != TCP_LISTEN) | |
321 | goto out_err; | |
322 | ||
323 | /* Find already established connection */ | |
8336886f | 324 | if (reqsk_queue_empty(queue)) { |
3f421baa ACM |
325 | long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); |
326 | ||
327 | /* If this is a non blocking socket don't sleep */ | |
328 | error = -EAGAIN; | |
329 | if (!timeo) | |
330 | goto out_err; | |
331 | ||
332 | error = inet_csk_wait_for_connect(sk, timeo); | |
333 | if (error) | |
334 | goto out_err; | |
335 | } | |
8336886f JC |
336 | req = reqsk_queue_remove(queue); |
337 | newsk = req->sk; | |
338 | ||
339 | sk_acceptq_removed(sk); | |
7ab4551f | 340 | if (sk->sk_protocol == IPPROTO_TCP && queue->fastopenq != NULL) { |
8336886f JC |
341 | spin_lock_bh(&queue->fastopenq->lock); |
342 | if (tcp_rsk(req)->listener) { | |
343 | /* We are still waiting for the final ACK from 3WHS | |
344 | * so can't free req now. Instead, we set req->sk to | |
345 | * NULL to signify that the child socket is taken | |
346 | * so reqsk_fastopen_remove() will free the req | |
347 | * when 3WHS finishes (or is aborted). | |
348 | */ | |
349 | req->sk = NULL; | |
350 | req = NULL; | |
351 | } | |
352 | spin_unlock_bh(&queue->fastopenq->lock); | |
353 | } | |
3f421baa ACM |
354 | out: |
355 | release_sock(sk); | |
8336886f JC |
356 | if (req) |
357 | __reqsk_free(req); | |
3f421baa ACM |
358 | return newsk; |
359 | out_err: | |
360 | newsk = NULL; | |
8336886f | 361 | req = NULL; |
3f421baa ACM |
362 | *err = error; |
363 | goto out; | |
364 | } | |
3f421baa ACM |
365 | EXPORT_SYMBOL(inet_csk_accept); |
366 | ||
367 | /* | |
368 | * Using different timers for retransmit, delayed acks and probes | |
e905a9ed | 369 | * We may wish use just one timer maintaining a list of expire jiffies |
3f421baa ACM |
370 | * to optimize. |
371 | */ | |
372 | void inet_csk_init_xmit_timers(struct sock *sk, | |
373 | void (*retransmit_handler)(unsigned long), | |
374 | void (*delack_handler)(unsigned long), | |
375 | void (*keepalive_handler)(unsigned long)) | |
376 | { | |
377 | struct inet_connection_sock *icsk = inet_csk(sk); | |
378 | ||
b24b8a24 PE |
379 | setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler, |
380 | (unsigned long)sk); | |
381 | setup_timer(&icsk->icsk_delack_timer, delack_handler, | |
382 | (unsigned long)sk); | |
383 | setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk); | |
3f421baa ACM |
384 | icsk->icsk_pending = icsk->icsk_ack.pending = 0; |
385 | } | |
3f421baa ACM |
386 | EXPORT_SYMBOL(inet_csk_init_xmit_timers); |
387 | ||
388 | void inet_csk_clear_xmit_timers(struct sock *sk) | |
389 | { | |
390 | struct inet_connection_sock *icsk = inet_csk(sk); | |
391 | ||
392 | icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0; | |
393 | ||
394 | sk_stop_timer(sk, &icsk->icsk_retransmit_timer); | |
395 | sk_stop_timer(sk, &icsk->icsk_delack_timer); | |
396 | sk_stop_timer(sk, &sk->sk_timer); | |
397 | } | |
3f421baa ACM |
398 | EXPORT_SYMBOL(inet_csk_clear_xmit_timers); |
399 | ||
400 | void inet_csk_delete_keepalive_timer(struct sock *sk) | |
401 | { | |
402 | sk_stop_timer(sk, &sk->sk_timer); | |
403 | } | |
3f421baa ACM |
404 | EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); |
405 | ||
406 | void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) | |
407 | { | |
408 | sk_reset_timer(sk, &sk->sk_timer, jiffies + len); | |
409 | } | |
3f421baa ACM |
410 | EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); |
411 | ||
d9319100 | 412 | struct dst_entry *inet_csk_route_req(struct sock *sk, |
6bd023f3 | 413 | struct flowi4 *fl4, |
ba3f7f04 | 414 | const struct request_sock *req) |
3f421baa ACM |
415 | { |
416 | struct rtable *rt; | |
417 | const struct inet_request_sock *ireq = inet_rsk(req); | |
f6d8bd05 | 418 | struct ip_options_rcu *opt = inet_rsk(req)->opt; |
84a3aa00 | 419 | struct net *net = sock_net(sk); |
3e12939a | 420 | int flags = inet_sk_flowi_flags(sk); |
3f421baa | 421 | |
6bd023f3 | 422 | flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, |
e79d9bc7 | 423 | RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, |
7433819a | 424 | sk->sk_protocol, |
7586eceb | 425 | flags, |
f6d8bd05 | 426 | (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, |
e79d9bc7 | 427 | ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); |
6bd023f3 DM |
428 | security_req_classify_flow(req, flowi4_to_flowi(fl4)); |
429 | rt = ip_route_output_flow(net, fl4, sk); | |
b23dd4fe | 430 | if (IS_ERR(rt)) |
857a6e0a | 431 | goto no_route; |
155e8336 | 432 | if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) |
857a6e0a | 433 | goto route_err; |
d8d1f30b | 434 | return &rt->dst; |
857a6e0a IJ |
435 | |
436 | route_err: | |
437 | ip_rt_put(rt); | |
438 | no_route: | |
439 | IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); | |
440 | return NULL; | |
3f421baa | 441 | } |
3f421baa ACM |
442 | EXPORT_SYMBOL_GPL(inet_csk_route_req); |
443 | ||
77357a95 DM |
444 | struct dst_entry *inet_csk_route_child_sock(struct sock *sk, |
445 | struct sock *newsk, | |
446 | const struct request_sock *req) | |
447 | { | |
448 | const struct inet_request_sock *ireq = inet_rsk(req); | |
449 | struct inet_sock *newinet = inet_sk(newsk); | |
1a7b27c9 | 450 | struct ip_options_rcu *opt; |
77357a95 DM |
451 | struct net *net = sock_net(sk); |
452 | struct flowi4 *fl4; | |
453 | struct rtable *rt; | |
454 | ||
455 | fl4 = &newinet->cork.fl.u.ip4; | |
1a7b27c9 CP |
456 | |
457 | rcu_read_lock(); | |
458 | opt = rcu_dereference(newinet->inet_opt); | |
77357a95 DM |
459 | flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, |
460 | RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, | |
461 | sk->sk_protocol, inet_sk_flowi_flags(sk), | |
462 | (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr, | |
463 | ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport); | |
464 | security_req_classify_flow(req, flowi4_to_flowi(fl4)); | |
465 | rt = ip_route_output_flow(net, fl4, sk); | |
466 | if (IS_ERR(rt)) | |
467 | goto no_route; | |
155e8336 | 468 | if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) |
77357a95 | 469 | goto route_err; |
1a7b27c9 | 470 | rcu_read_unlock(); |
77357a95 DM |
471 | return &rt->dst; |
472 | ||
473 | route_err: | |
474 | ip_rt_put(rt); | |
475 | no_route: | |
1a7b27c9 | 476 | rcu_read_unlock(); |
77357a95 DM |
477 | IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); |
478 | return NULL; | |
479 | } | |
480 | EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); | |
481 | ||
6b72977b | 482 | static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport, |
72a3effa | 483 | const u32 rnd, const u32 synq_hsize) |
3f421baa | 484 | { |
6b72977b | 485 | return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1); |
3f421baa ACM |
486 | } |
487 | ||
dfd56b8b | 488 | #if IS_ENABLED(CONFIG_IPV6) |
3f421baa ACM |
489 | #define AF_INET_FAMILY(fam) ((fam) == AF_INET) |
490 | #else | |
491 | #define AF_INET_FAMILY(fam) 1 | |
492 | #endif | |
493 | ||
494 | struct request_sock *inet_csk_search_req(const struct sock *sk, | |
495 | struct request_sock ***prevp, | |
6b72977b | 496 | const __be16 rport, const __be32 raddr, |
7f25afbb | 497 | const __be32 laddr) |
3f421baa ACM |
498 | { |
499 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
500 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | |
501 | struct request_sock *req, **prev; | |
502 | ||
503 | for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd, | |
504 | lopt->nr_table_entries)]; | |
505 | (req = *prev) != NULL; | |
506 | prev = &req->dl_next) { | |
507 | const struct inet_request_sock *ireq = inet_rsk(req); | |
508 | ||
509 | if (ireq->rmt_port == rport && | |
510 | ireq->rmt_addr == raddr && | |
511 | ireq->loc_addr == laddr && | |
512 | AF_INET_FAMILY(req->rsk_ops->family)) { | |
547b792c | 513 | WARN_ON(req->sk); |
3f421baa ACM |
514 | *prevp = prev; |
515 | break; | |
516 | } | |
517 | } | |
518 | ||
519 | return req; | |
520 | } | |
3f421baa ACM |
521 | EXPORT_SYMBOL_GPL(inet_csk_search_req); |
522 | ||
523 | void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, | |
c2977c22 | 524 | unsigned long timeout) |
3f421baa ACM |
525 | { |
526 | struct inet_connection_sock *icsk = inet_csk(sk); | |
527 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; | |
528 | const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, | |
529 | lopt->hash_rnd, lopt->nr_table_entries); | |
530 | ||
531 | reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); | |
532 | inet_csk_reqsk_queue_added(sk, timeout); | |
533 | } | |
4bc2f18b | 534 | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); |
3f421baa | 535 | |
a019d6fe ACM |
536 | /* Only thing we need from tcp.h */ |
537 | extern int sysctl_tcp_synack_retries; | |
538 | ||
9f1d2604 | 539 | |
0c3d79bc JA |
540 | /* Decide when to expire the request and when to resend SYN-ACK */ |
541 | static inline void syn_ack_recalc(struct request_sock *req, const int thresh, | |
542 | const int max_retries, | |
543 | const u8 rskq_defer_accept, | |
544 | int *expire, int *resend) | |
545 | { | |
546 | if (!rskq_defer_accept) { | |
e6c022a4 | 547 | *expire = req->num_timeout >= thresh; |
0c3d79bc JA |
548 | *resend = 1; |
549 | return; | |
550 | } | |
e6c022a4 ED |
551 | *expire = req->num_timeout >= thresh && |
552 | (!inet_rsk(req)->acked || req->num_timeout >= max_retries); | |
0c3d79bc JA |
553 | /* |
554 | * Do not resend while waiting for data after ACK, | |
555 | * start to resend on end of deferring period to give | |
556 | * last chance for data or ACK to create established socket. | |
557 | */ | |
558 | *resend = !inet_rsk(req)->acked || | |
e6c022a4 | 559 | req->num_timeout >= rskq_defer_accept - 1; |
0c3d79bc JA |
560 | } |
561 | ||
e6c022a4 ED |
562 | int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req) |
563 | { | |
564 | int err = req->rsk_ops->rtx_syn_ack(parent, req, NULL); | |
565 | ||
566 | if (!err) | |
567 | req->num_retrans++; | |
568 | return err; | |
569 | } | |
570 | EXPORT_SYMBOL(inet_rtx_syn_ack); | |
571 | ||
a019d6fe ACM |
572 | void inet_csk_reqsk_queue_prune(struct sock *parent, |
573 | const unsigned long interval, | |
574 | const unsigned long timeout, | |
575 | const unsigned long max_rto) | |
576 | { | |
577 | struct inet_connection_sock *icsk = inet_csk(parent); | |
578 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; | |
579 | struct listen_sock *lopt = queue->listen_opt; | |
ec0a1966 DM |
580 | int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries; |
581 | int thresh = max_retries; | |
a019d6fe ACM |
582 | unsigned long now = jiffies; |
583 | struct request_sock **reqp, *req; | |
584 | int i, budget; | |
585 | ||
586 | if (lopt == NULL || lopt->qlen == 0) | |
587 | return; | |
588 | ||
589 | /* Normally all the openreqs are young and become mature | |
590 | * (i.e. converted to established socket) for first timeout. | |
fd4f2cea | 591 | * If synack was not acknowledged for 1 second, it means |
a019d6fe ACM |
592 | * one of the following things: synack was lost, ack was lost, |
593 | * rtt is high or nobody planned to ack (i.e. synflood). | |
594 | * When server is a bit loaded, queue is populated with old | |
595 | * open requests, reducing effective size of queue. | |
596 | * When server is well loaded, queue size reduces to zero | |
597 | * after several minutes of work. It is not synflood, | |
598 | * it is normal operation. The solution is pruning | |
599 | * too old entries overriding normal timeout, when | |
600 | * situation becomes dangerous. | |
601 | * | |
602 | * Essentially, we reserve half of room for young | |
603 | * embrions; and abort old ones without pity, if old | |
604 | * ones are about to clog our table. | |
605 | */ | |
606 | if (lopt->qlen>>(lopt->max_qlen_log-1)) { | |
607 | int young = (lopt->qlen_young<<1); | |
608 | ||
609 | while (thresh > 2) { | |
610 | if (lopt->qlen < young) | |
611 | break; | |
612 | thresh--; | |
613 | young <<= 1; | |
614 | } | |
615 | } | |
616 | ||
ec0a1966 DM |
617 | if (queue->rskq_defer_accept) |
618 | max_retries = queue->rskq_defer_accept; | |
619 | ||
a019d6fe ACM |
620 | budget = 2 * (lopt->nr_table_entries / (timeout / interval)); |
621 | i = lopt->clock_hand; | |
622 | ||
623 | do { | |
624 | reqp=&lopt->syn_table[i]; | |
625 | while ((req = *reqp) != NULL) { | |
626 | if (time_after_eq(now, req->expires)) { | |
0c3d79bc JA |
627 | int expire = 0, resend = 0; |
628 | ||
629 | syn_ack_recalc(req, thresh, max_retries, | |
630 | queue->rskq_defer_accept, | |
631 | &expire, &resend); | |
c72e1183 | 632 | req->rsk_ops->syn_ack_timeout(parent, req); |
0c3d79bc JA |
633 | if (!expire && |
634 | (!resend || | |
e6c022a4 | 635 | !inet_rtx_syn_ack(parent, req) || |
0c3d79bc | 636 | inet_rsk(req)->acked)) { |
a019d6fe ACM |
637 | unsigned long timeo; |
638 | ||
e6c022a4 | 639 | if (req->num_timeout++ == 0) |
a019d6fe | 640 | lopt->qlen_young--; |
e6c022a4 ED |
641 | timeo = min(timeout << req->num_timeout, |
642 | max_rto); | |
a019d6fe ACM |
643 | req->expires = now + timeo; |
644 | reqp = &req->dl_next; | |
645 | continue; | |
646 | } | |
647 | ||
648 | /* Drop this request */ | |
649 | inet_csk_reqsk_queue_unlink(parent, req, reqp); | |
650 | reqsk_queue_removed(queue, req); | |
651 | reqsk_free(req); | |
652 | continue; | |
653 | } | |
654 | reqp = &req->dl_next; | |
655 | } | |
656 | ||
657 | i = (i + 1) & (lopt->nr_table_entries - 1); | |
658 | ||
659 | } while (--budget > 0); | |
660 | ||
661 | lopt->clock_hand = i; | |
662 | ||
663 | if (lopt->qlen) | |
664 | inet_csk_reset_keepalive_timer(parent, interval); | |
665 | } | |
a019d6fe ACM |
666 | EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune); |
667 | ||
e56c57d0 ED |
668 | /** |
669 | * inet_csk_clone_lock - clone an inet socket, and lock its clone | |
670 | * @sk: the socket to clone | |
671 | * @req: request_sock | |
672 | * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) | |
673 | * | |
674 | * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) | |
675 | */ | |
676 | struct sock *inet_csk_clone_lock(const struct sock *sk, | |
677 | const struct request_sock *req, | |
678 | const gfp_t priority) | |
9f1d2604 | 679 | { |
e56c57d0 | 680 | struct sock *newsk = sk_clone_lock(sk, priority); |
9f1d2604 ACM |
681 | |
682 | if (newsk != NULL) { | |
683 | struct inet_connection_sock *newicsk = inet_csk(newsk); | |
684 | ||
685 | newsk->sk_state = TCP_SYN_RECV; | |
686 | newicsk->icsk_bind_hash = NULL; | |
687 | ||
c720c7e8 ED |
688 | inet_sk(newsk)->inet_dport = inet_rsk(req)->rmt_port; |
689 | inet_sk(newsk)->inet_num = ntohs(inet_rsk(req)->loc_port); | |
690 | inet_sk(newsk)->inet_sport = inet_rsk(req)->loc_port; | |
9f1d2604 ACM |
691 | newsk->sk_write_space = sk_stream_write_space; |
692 | ||
693 | newicsk->icsk_retransmits = 0; | |
6687e988 ACM |
694 | newicsk->icsk_backoff = 0; |
695 | newicsk->icsk_probes_out = 0; | |
9f1d2604 ACM |
696 | |
697 | /* Deinitialize accept_queue to trap illegal accesses. */ | |
698 | memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); | |
4237c75c VY |
699 | |
700 | security_inet_csk_clone(newsk, req); | |
9f1d2604 ACM |
701 | } |
702 | return newsk; | |
703 | } | |
e56c57d0 | 704 | EXPORT_SYMBOL_GPL(inet_csk_clone_lock); |
a019d6fe ACM |
705 | |
706 | /* | |
707 | * At this point, there should be no process reference to this | |
708 | * socket, and thus no user references at all. Therefore we | |
709 | * can assume the socket waitqueue is inactive and nobody will | |
710 | * try to jump onto it. | |
711 | */ | |
712 | void inet_csk_destroy_sock(struct sock *sk) | |
713 | { | |
547b792c IJ |
714 | WARN_ON(sk->sk_state != TCP_CLOSE); |
715 | WARN_ON(!sock_flag(sk, SOCK_DEAD)); | |
a019d6fe ACM |
716 | |
717 | /* It cannot be in hash table! */ | |
547b792c | 718 | WARN_ON(!sk_unhashed(sk)); |
a019d6fe | 719 | |
c720c7e8 ED |
720 | /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ |
721 | WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); | |
a019d6fe ACM |
722 | |
723 | sk->sk_prot->destroy(sk); | |
724 | ||
725 | sk_stream_kill_queues(sk); | |
726 | ||
727 | xfrm_sk_free_policy(sk); | |
728 | ||
729 | sk_refcnt_debug_release(sk); | |
730 | ||
dd24c001 | 731 | percpu_counter_dec(sk->sk_prot->orphan_count); |
a019d6fe ACM |
732 | sock_put(sk); |
733 | } | |
a019d6fe ACM |
734 | EXPORT_SYMBOL(inet_csk_destroy_sock); |
735 | ||
e337e24d CP |
736 | /* This function allows to force a closure of a socket after the call to |
737 | * tcp/dccp_create_openreq_child(). | |
738 | */ | |
739 | void inet_csk_prepare_forced_close(struct sock *sk) | |
740 | { | |
741 | /* sk_clone_lock locked the socket and set refcnt to 2 */ | |
742 | bh_unlock_sock(sk); | |
743 | sock_put(sk); | |
744 | ||
745 | /* The below has to be done to allow calling inet_csk_destroy_sock */ | |
746 | sock_set_flag(sk, SOCK_DEAD); | |
747 | percpu_counter_inc(sk->sk_prot->orphan_count); | |
748 | inet_sk(sk)->inet_num = 0; | |
749 | } | |
750 | EXPORT_SYMBOL(inet_csk_prepare_forced_close); | |
751 | ||
a019d6fe ACM |
752 | int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) |
753 | { | |
754 | struct inet_sock *inet = inet_sk(sk); | |
755 | struct inet_connection_sock *icsk = inet_csk(sk); | |
756 | int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries); | |
757 | ||
758 | if (rc != 0) | |
759 | return rc; | |
760 | ||
761 | sk->sk_max_ack_backlog = 0; | |
762 | sk->sk_ack_backlog = 0; | |
763 | inet_csk_delack_init(sk); | |
764 | ||
765 | /* There is race window here: we announce ourselves listening, | |
766 | * but this transition is still not validated by get_port(). | |
767 | * It is OK, because this socket enters to hash table only | |
768 | * after validation is complete. | |
769 | */ | |
770 | sk->sk_state = TCP_LISTEN; | |
c720c7e8 ED |
771 | if (!sk->sk_prot->get_port(sk, inet->inet_num)) { |
772 | inet->inet_sport = htons(inet->inet_num); | |
a019d6fe ACM |
773 | |
774 | sk_dst_reset(sk); | |
775 | sk->sk_prot->hash(sk); | |
776 | ||
777 | return 0; | |
778 | } | |
779 | ||
780 | sk->sk_state = TCP_CLOSE; | |
781 | __reqsk_queue_destroy(&icsk->icsk_accept_queue); | |
782 | return -EADDRINUSE; | |
783 | } | |
a019d6fe ACM |
784 | EXPORT_SYMBOL_GPL(inet_csk_listen_start); |
785 | ||
786 | /* | |
787 | * This routine closes sockets which have been at least partially | |
788 | * opened, but not yet accepted. | |
789 | */ | |
790 | void inet_csk_listen_stop(struct sock *sk) | |
791 | { | |
792 | struct inet_connection_sock *icsk = inet_csk(sk); | |
8336886f | 793 | struct request_sock_queue *queue = &icsk->icsk_accept_queue; |
a019d6fe ACM |
794 | struct request_sock *acc_req; |
795 | struct request_sock *req; | |
796 | ||
797 | inet_csk_delete_keepalive_timer(sk); | |
798 | ||
799 | /* make all the listen_opt local to us */ | |
8336886f | 800 | acc_req = reqsk_queue_yank_acceptq(queue); |
a019d6fe ACM |
801 | |
802 | /* Following specs, it would be better either to send FIN | |
803 | * (and enter FIN-WAIT-1, it is normal close) | |
804 | * or to send active reset (abort). | |
805 | * Certainly, it is pretty dangerous while synflood, but it is | |
806 | * bad justification for our negligence 8) | |
807 | * To be honest, we are not able to make either | |
808 | * of the variants now. --ANK | |
809 | */ | |
8336886f | 810 | reqsk_queue_destroy(queue); |
a019d6fe ACM |
811 | |
812 | while ((req = acc_req) != NULL) { | |
813 | struct sock *child = req->sk; | |
814 | ||
815 | acc_req = req->dl_next; | |
816 | ||
817 | local_bh_disable(); | |
818 | bh_lock_sock(child); | |
547b792c | 819 | WARN_ON(sock_owned_by_user(child)); |
a019d6fe ACM |
820 | sock_hold(child); |
821 | ||
822 | sk->sk_prot->disconnect(child, O_NONBLOCK); | |
823 | ||
824 | sock_orphan(child); | |
825 | ||
eb4dea58 HX |
826 | percpu_counter_inc(sk->sk_prot->orphan_count); |
827 | ||
7ab4551f | 828 | if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->listener) { |
8336886f JC |
829 | BUG_ON(tcp_sk(child)->fastopen_rsk != req); |
830 | BUG_ON(sk != tcp_rsk(req)->listener); | |
831 | ||
832 | /* Paranoid, to prevent race condition if | |
833 | * an inbound pkt destined for child is | |
834 | * blocked by sock lock in tcp_v4_rcv(). | |
835 | * Also to satisfy an assertion in | |
836 | * tcp_v4_destroy_sock(). | |
837 | */ | |
838 | tcp_sk(child)->fastopen_rsk = NULL; | |
839 | sock_put(sk); | |
840 | } | |
a019d6fe ACM |
841 | inet_csk_destroy_sock(child); |
842 | ||
843 | bh_unlock_sock(child); | |
844 | local_bh_enable(); | |
845 | sock_put(child); | |
846 | ||
847 | sk_acceptq_removed(sk); | |
848 | __reqsk_free(req); | |
849 | } | |
8336886f JC |
850 | if (queue->fastopenq != NULL) { |
851 | /* Free all the reqs queued in rskq_rst_head. */ | |
852 | spin_lock_bh(&queue->fastopenq->lock); | |
853 | acc_req = queue->fastopenq->rskq_rst_head; | |
854 | queue->fastopenq->rskq_rst_head = NULL; | |
855 | spin_unlock_bh(&queue->fastopenq->lock); | |
856 | while ((req = acc_req) != NULL) { | |
857 | acc_req = req->dl_next; | |
858 | __reqsk_free(req); | |
859 | } | |
860 | } | |
547b792c | 861 | WARN_ON(sk->sk_ack_backlog); |
a019d6fe | 862 | } |
a019d6fe | 863 | EXPORT_SYMBOL_GPL(inet_csk_listen_stop); |
af05dc93 ACM |
864 | |
865 | void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) | |
866 | { | |
867 | struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; | |
868 | const struct inet_sock *inet = inet_sk(sk); | |
869 | ||
870 | sin->sin_family = AF_INET; | |
c720c7e8 ED |
871 | sin->sin_addr.s_addr = inet->inet_daddr; |
872 | sin->sin_port = inet->inet_dport; | |
af05dc93 | 873 | } |
af05dc93 | 874 | EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); |
c4d93909 | 875 | |
dec73ff0 ACM |
876 | #ifdef CONFIG_COMPAT |
877 | int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, | |
878 | char __user *optval, int __user *optlen) | |
879 | { | |
dbeff12b | 880 | const struct inet_connection_sock *icsk = inet_csk(sk); |
dec73ff0 ACM |
881 | |
882 | if (icsk->icsk_af_ops->compat_getsockopt != NULL) | |
883 | return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname, | |
884 | optval, optlen); | |
885 | return icsk->icsk_af_ops->getsockopt(sk, level, optname, | |
886 | optval, optlen); | |
887 | } | |
dec73ff0 ACM |
888 | EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt); |
889 | ||
890 | int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, | |
b7058842 | 891 | char __user *optval, unsigned int optlen) |
dec73ff0 | 892 | { |
dbeff12b | 893 | const struct inet_connection_sock *icsk = inet_csk(sk); |
dec73ff0 ACM |
894 | |
895 | if (icsk->icsk_af_ops->compat_setsockopt != NULL) | |
896 | return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname, | |
897 | optval, optlen); | |
898 | return icsk->icsk_af_ops->setsockopt(sk, level, optname, | |
899 | optval, optlen); | |
900 | } | |
dec73ff0 ACM |
901 | EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt); |
902 | #endif | |
80d0a69f DM |
903 | |
904 | static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl) | |
905 | { | |
5abf7f7e ED |
906 | const struct inet_sock *inet = inet_sk(sk); |
907 | const struct ip_options_rcu *inet_opt; | |
80d0a69f DM |
908 | __be32 daddr = inet->inet_daddr; |
909 | struct flowi4 *fl4; | |
910 | struct rtable *rt; | |
911 | ||
912 | rcu_read_lock(); | |
913 | inet_opt = rcu_dereference(inet->inet_opt); | |
914 | if (inet_opt && inet_opt->opt.srr) | |
915 | daddr = inet_opt->opt.faddr; | |
916 | fl4 = &fl->u.ip4; | |
917 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, | |
918 | inet->inet_saddr, inet->inet_dport, | |
919 | inet->inet_sport, sk->sk_protocol, | |
920 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); | |
921 | if (IS_ERR(rt)) | |
922 | rt = NULL; | |
923 | if (rt) | |
924 | sk_setup_caps(sk, &rt->dst); | |
925 | rcu_read_unlock(); | |
926 | ||
927 | return &rt->dst; | |
928 | } | |
929 | ||
930 | struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu) | |
931 | { | |
932 | struct dst_entry *dst = __sk_dst_check(sk, 0); | |
933 | struct inet_sock *inet = inet_sk(sk); | |
934 | ||
935 | if (!dst) { | |
936 | dst = inet_csk_rebuild_route(sk, &inet->cork.fl); | |
937 | if (!dst) | |
938 | goto out; | |
939 | } | |
6700c270 | 940 | dst->ops->update_pmtu(dst, sk, NULL, mtu); |
80d0a69f DM |
941 | |
942 | dst = __sk_dst_check(sk, 0); | |
943 | if (!dst) | |
944 | dst = inet_csk_rebuild_route(sk, &inet->cork.fl); | |
945 | out: | |
946 | return dst; | |
947 | } | |
948 | EXPORT_SYMBOL_GPL(inet_csk_update_pmtu); |