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nfsd: remove duplicate init in nfsd4_cb_recall
[linux-2.6/libata-dev.git] / net / ipv4 / tcp_ipv4.c
blob76782376401637e0709123564dd06b57c7196e3a
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 * Implementation of the Transmission Control Protocol(TCP).
7 *
8 * IPv4 specific functions
9 *
10 *
11 * code split from:
12 * linux/ipv4/tcp.c
13 * linux/ipv4/tcp_input.c
14 * linux/ipv4/tcp_output.c
15 *
16 * See tcp.c for author information
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 /*
25 * Changes:
26 * David S. Miller : New socket lookup architecture.
27 * This code is dedicated to John Dyson.
28 * David S. Miller : Change semantics of established hash,
29 * half is devoted to TIME_WAIT sockets
30 * and the rest go in the other half.
31 * Andi Kleen : Add support for syncookies and fixed
32 * some bugs: ip options weren't passed to
33 * the TCP layer, missed a check for an
34 * ACK bit.
35 * Andi Kleen : Implemented fast path mtu discovery.
36 * Fixed many serious bugs in the
37 * request_sock handling and moved
38 * most of it into the af independent code.
39 * Added tail drop and some other bugfixes.
40 * Added new listen semantics.
41 * Mike McLagan : Routing by source
42 * Juan Jose Ciarlante: ip_dynaddr bits
43 * Andi Kleen: various fixes.
44 * Vitaly E. Lavrov : Transparent proxy revived after year
45 * coma.
46 * Andi Kleen : Fix new listen.
47 * Andi Kleen : Fix accept error reporting.
48 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
49 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
50 * a single port at the same time.
51 */
52
53 #define pr_fmt(fmt) "TCP: " fmt
54
55 #include <linux/bottom_half.h>
56 #include <linux/types.h>
57 #include <linux/fcntl.h>
58 #include <linux/module.h>
59 #include <linux/random.h>
60 #include <linux/cache.h>
61 #include <linux/jhash.h>
62 #include <linux/init.h>
63 #include <linux/times.h>
64 #include <linux/slab.h>
65
66 #include <net/net_namespace.h>
67 #include <net/icmp.h>
68 #include <net/inet_hashtables.h>
69 #include <net/tcp.h>
70 #include <net/transp_v6.h>
71 #include <net/ipv6.h>
72 #include <net/inet_common.h>
73 #include <net/timewait_sock.h>
74 #include <net/xfrm.h>
75 #include <net/netdma.h>
76 #include <net/secure_seq.h>
77 #include <net/tcp_memcontrol.h>
78
79 #include <linux/inet.h>
80 #include <linux/ipv6.h>
81 #include <linux/stddef.h>
82 #include <linux/proc_fs.h>
83 #include <linux/seq_file.h>
84
85 #include <linux/crypto.h>
86 #include <linux/scatterlist.h>
87
88 int sysctl_tcp_tw_reuse __read_mostly;
89 int sysctl_tcp_low_latency __read_mostly;
90 EXPORT_SYMBOL(sysctl_tcp_low_latency);
91
92
93 #ifdef CONFIG_TCP_MD5SIG
94 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
95 __be32 daddr, __be32 saddr, const struct tcphdr *th);
96 #endif
97
98 struct inet_hashinfo tcp_hashinfo;
99 EXPORT_SYMBOL(tcp_hashinfo);
100
101 static inline __u32 tcp_v4_init_sequence(const struct sk_buff *skb)
102 {
103 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
104 ip_hdr(skb)->saddr,
105 tcp_hdr(skb)->dest,
106 tcp_hdr(skb)->source);
107 }
108
109 int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
110 {
111 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
112 struct tcp_sock *tp = tcp_sk(sk);
113
114 /* With PAWS, it is safe from the viewpoint
115 of data integrity. Even without PAWS it is safe provided sequence
116 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
117
118 Actually, the idea is close to VJ's one, only timestamp cache is
119 held not per host, but per port pair and TW bucket is used as state
120 holder.
121
122 If TW bucket has been already destroyed we fall back to VJ's scheme
123 and use initial timestamp retrieved from peer table.
124 */
125 if (tcptw->tw_ts_recent_stamp &&
126 (twp == NULL || (sysctl_tcp_tw_reuse &&
127 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
128 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
129 if (tp->write_seq == 0)
130 tp->write_seq = 1;
131 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
132 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
133 sock_hold(sktw);
134 return 1;
135 }
136
137 return 0;
138 }
139 EXPORT_SYMBOL_GPL(tcp_twsk_unique);
140
141 static int tcp_repair_connect(struct sock *sk)
142 {
143 tcp_connect_init(sk);
144 tcp_finish_connect(sk, NULL);
145
146 return 0;
147 }
148
149 /* This will initiate an outgoing connection. */
150 int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
151 {
152 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
153 struct inet_sock *inet = inet_sk(sk);
154 struct tcp_sock *tp = tcp_sk(sk);
155 __be16 orig_sport, orig_dport;
156 __be32 daddr, nexthop;
157 struct flowi4 *fl4;
158 struct rtable *rt;
159 int err;
160 struct ip_options_rcu *inet_opt;
161
162 if (addr_len < sizeof(struct sockaddr_in))
163 return -EINVAL;
164
165 if (usin->sin_family != AF_INET)
166 return -EAFNOSUPPORT;
167
168 nexthop = daddr = usin->sin_addr.s_addr;
169 inet_opt = rcu_dereference_protected(inet->inet_opt,
170 sock_owned_by_user(sk));
171 if (inet_opt && inet_opt->opt.srr) {
172 if (!daddr)
173 return -EINVAL;
174 nexthop = inet_opt->opt.faddr;
175 }
176
177 orig_sport = inet->inet_sport;
178 orig_dport = usin->sin_port;
179 fl4 = &inet->cork.fl.u.ip4;
180 rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
181 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
182 IPPROTO_TCP,
183 orig_sport, orig_dport, sk, true);
184 if (IS_ERR(rt)) {
185 err = PTR_ERR(rt);
186 if (err == -ENETUNREACH)
187 IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
188 return err;
189 }
190
191 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
192 ip_rt_put(rt);
193 return -ENETUNREACH;
194 }
195
196 if (!inet_opt || !inet_opt->opt.srr)
197 daddr = fl4->daddr;
198
199 if (!inet->inet_saddr)
200 inet->inet_saddr = fl4->saddr;
201 inet->inet_rcv_saddr = inet->inet_saddr;
202
203 if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) {
204 /* Reset inherited state */
205 tp->rx_opt.ts_recent = 0;
206 tp->rx_opt.ts_recent_stamp = 0;
207 if (likely(!tp->repair))
208 tp->write_seq = 0;
209 }
210
211 if (tcp_death_row.sysctl_tw_recycle &&
212 !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr)
213 tcp_fetch_timewait_stamp(sk, &rt->dst);
214
215 inet->inet_dport = usin->sin_port;
216 inet->inet_daddr = daddr;
217
218 inet_csk(sk)->icsk_ext_hdr_len = 0;
219 if (inet_opt)
220 inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
221
222 tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
223
224 /* Socket identity is still unknown (sport may be zero).
225 * However we set state to SYN-SENT and not releasing socket
226 * lock select source port, enter ourselves into the hash tables and
227 * complete initialization after this.
228 */
229 tcp_set_state(sk, TCP_SYN_SENT);
230 err = inet_hash_connect(&tcp_death_row, sk);
231 if (err)
232 goto failure;
233
234 rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
235 inet->inet_sport, inet->inet_dport, sk);
236 if (IS_ERR(rt)) {
237 err = PTR_ERR(rt);
238 rt = NULL;
239 goto failure;
240 }
241 /* OK, now commit destination to socket. */
242 sk->sk_gso_type = SKB_GSO_TCPV4;
243 sk_setup_caps(sk, &rt->dst);
244
245 if (!tp->write_seq && likely(!tp->repair))
246 tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr,
247 inet->inet_daddr,
248 inet->inet_sport,
249 usin->sin_port);
250
251 inet->inet_id = tp->write_seq ^ jiffies;
252
253 if (likely(!tp->repair))
254 err = tcp_connect(sk);
255 else
256 err = tcp_repair_connect(sk);
257
258 rt = NULL;
259 if (err)
260 goto failure;
261
262 return 0;
263
264 failure:
265 /*
266 * This unhashes the socket and releases the local port,
267 * if necessary.
268 */
269 tcp_set_state(sk, TCP_CLOSE);
270 ip_rt_put(rt);
271 sk->sk_route_caps = 0;
272 inet->inet_dport = 0;
273 return err;
274 }
275 EXPORT_SYMBOL(tcp_v4_connect);
276
277 /*
278 * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191.
279 * It can be called through tcp_release_cb() if socket was owned by user
280 * at the time tcp_v4_err() was called to handle ICMP message.
281 */
282 static void tcp_v4_mtu_reduced(struct sock *sk)
283 {
284 struct dst_entry *dst;
285 struct inet_sock *inet = inet_sk(sk);
286 u32 mtu = tcp_sk(sk)->mtu_info;
287
288 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
289 * send out by Linux are always <576bytes so they should go through
290 * unfragmented).
291 */
292 if (sk->sk_state == TCP_LISTEN)
293 return;
294
295 dst = inet_csk_update_pmtu(sk, mtu);
296 if (!dst)
297 return;
298
299 /* Something is about to be wrong... Remember soft error
300 * for the case, if this connection will not able to recover.
301 */
302 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
303 sk->sk_err_soft = EMSGSIZE;
304
305 mtu = dst_mtu(dst);
306
307 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
308 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
309 tcp_sync_mss(sk, mtu);
310
311 /* Resend the TCP packet because it's
312 * clear that the old packet has been
313 * dropped. This is the new "fast" path mtu
314 * discovery.
315 */
316 tcp_simple_retransmit(sk);
317 } /* else let the usual retransmit timer handle it */
318 }
319
320 static void do_redirect(struct sk_buff *skb, struct sock *sk)
321 {
322 struct dst_entry *dst = __sk_dst_check(sk, 0);
323
324 if (dst)
325 dst->ops->redirect(dst, sk, skb);
326 }
327
328 /*
329 * This routine is called by the ICMP module when it gets some
330 * sort of error condition. If err < 0 then the socket should
331 * be closed and the error returned to the user. If err > 0
332 * it's just the icmp type << 8 | icmp code. After adjustment
333 * header points to the first 8 bytes of the tcp header. We need
334 * to find the appropriate port.
335 *
336 * The locking strategy used here is very "optimistic". When
337 * someone else accesses the socket the ICMP is just dropped
338 * and for some paths there is no check at all.
339 * A more general error queue to queue errors for later handling
340 * is probably better.
341 *
342 */
343
344 void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
345 {
346 const struct iphdr *iph = (const struct iphdr *)icmp_skb->data;
347 struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));
348 struct inet_connection_sock *icsk;
349 struct tcp_sock *tp;
350 struct inet_sock *inet;
351 const int type = icmp_hdr(icmp_skb)->type;
352 const int code = icmp_hdr(icmp_skb)->code;
353 struct sock *sk;
354 struct sk_buff *skb;
355 __u32 seq;
356 __u32 remaining;
357 int err;
358 struct net *net = dev_net(icmp_skb->dev);
359
360 if (icmp_skb->len < (iph->ihl << 2) + 8) {
361 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
362 return;
363 }
364
365 sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
366 iph->saddr, th->source, inet_iif(icmp_skb));
367 if (!sk) {
368 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
369 return;
370 }
371 if (sk->sk_state == TCP_TIME_WAIT) {
372 inet_twsk_put(inet_twsk(sk));
373 return;
374 }
375
376 bh_lock_sock(sk);
377 /* If too many ICMPs get dropped on busy
378 * servers this needs to be solved differently.
379 * We do take care of PMTU discovery (RFC1191) special case :
380 * we can receive locally generated ICMP messages while socket is held.
381 */
382 if (sock_owned_by_user(sk) &&
383 type != ICMP_DEST_UNREACH &&
384 code != ICMP_FRAG_NEEDED)
385 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
386
387 if (sk->sk_state == TCP_CLOSE)
388 goto out;
389
390 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
391 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
392 goto out;
393 }
394
395 icsk = inet_csk(sk);
396 tp = tcp_sk(sk);
397 seq = ntohl(th->seq);
398 if (sk->sk_state != TCP_LISTEN &&
399 !between(seq, tp->snd_una, tp->snd_nxt)) {
400 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
401 goto out;
402 }
403
404 switch (type) {
405 case ICMP_REDIRECT:
406 do_redirect(icmp_skb, sk);
407 goto out;
408 case ICMP_SOURCE_QUENCH:
409 /* Just silently ignore these. */
410 goto out;
411 case ICMP_PARAMETERPROB:
412 err = EPROTO;
413 break;
414 case ICMP_DEST_UNREACH:
415 if (code > NR_ICMP_UNREACH)
416 goto out;
417
418 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
419 tp->mtu_info = info;
420 if (!sock_owned_by_user(sk))
421 tcp_v4_mtu_reduced(sk);
422 else
423 set_bit(TCP_MTU_REDUCED_DEFERRED, &tp->tsq_flags);
424 goto out;
425 }
426
427 err = icmp_err_convert[code].errno;
428 /* check if icmp_skb allows revert of backoff
429 * (see draft-zimmermann-tcp-lcd) */
430 if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
431 break;
432 if (seq != tp->snd_una || !icsk->icsk_retransmits ||
433 !icsk->icsk_backoff)
434 break;
435
436 if (sock_owned_by_user(sk))
437 break;
438
439 icsk->icsk_backoff--;
440 inet_csk(sk)->icsk_rto = (tp->srtt ? __tcp_set_rto(tp) :
441 TCP_TIMEOUT_INIT) << icsk->icsk_backoff;
442 tcp_bound_rto(sk);
443
444 skb = tcp_write_queue_head(sk);
445 BUG_ON(!skb);
446
447 remaining = icsk->icsk_rto - min(icsk->icsk_rto,
448 tcp_time_stamp - TCP_SKB_CB(skb)->when);
449
450 if (remaining) {
451 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
452 remaining, TCP_RTO_MAX);
453 } else {
454 /* RTO revert clocked out retransmission.
455 * Will retransmit now */
456 tcp_retransmit_timer(sk);
457 }
458
459 break;
460 case ICMP_TIME_EXCEEDED:
461 err = EHOSTUNREACH;
462 break;
463 default:
464 goto out;
465 }
466
467 switch (sk->sk_state) {
468 struct request_sock *req, **prev;
469 case TCP_LISTEN:
470 if (sock_owned_by_user(sk))
471 goto out;
472
473 req = inet_csk_search_req(sk, &prev, th->dest,
474 iph->daddr, iph->saddr);
475 if (!req)
476 goto out;
477
478 /* ICMPs are not backlogged, hence we cannot get
479 an established socket here.
480 */
481 WARN_ON(req->sk);
482
483 if (seq != tcp_rsk(req)->snt_isn) {
484 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
485 goto out;
486 }
487
488 /*
489 * Still in SYN_RECV, just remove it silently.
490 * There is no good way to pass the error to the newly
491 * created socket, and POSIX does not want network
492 * errors returned from accept().
493 */
494 inet_csk_reqsk_queue_drop(sk, req, prev);
495 goto out;
496
497 case TCP_SYN_SENT:
498 case TCP_SYN_RECV: /* Cannot happen.
499 It can f.e. if SYNs crossed.
500 */
501 if (!sock_owned_by_user(sk)) {
502 sk->sk_err = err;
503
504 sk->sk_error_report(sk);
505
506 tcp_done(sk);
507 } else {
508 sk->sk_err_soft = err;
509 }
510 goto out;
511 }
512
513 /* If we've already connected we will keep trying
514 * until we time out, or the user gives up.
515 *
516 * rfc1122 4.2.3.9 allows to consider as hard errors
517 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
518 * but it is obsoleted by pmtu discovery).
519 *
520 * Note, that in modern internet, where routing is unreliable
521 * and in each dark corner broken firewalls sit, sending random
522 * errors ordered by their masters even this two messages finally lose
523 * their original sense (even Linux sends invalid PORT_UNREACHs)
524 *
525 * Now we are in compliance with RFCs.
526 * --ANK (980905)
527 */
528
529 inet = inet_sk(sk);
530 if (!sock_owned_by_user(sk) && inet->recverr) {
531 sk->sk_err = err;
532 sk->sk_error_report(sk);
533 } else { /* Only an error on timeout */
534 sk->sk_err_soft = err;
535 }
536
537 out:
538 bh_unlock_sock(sk);
539 sock_put(sk);
540 }
541
542 static void __tcp_v4_send_check(struct sk_buff *skb,
543 __be32 saddr, __be32 daddr)
544 {
545 struct tcphdr *th = tcp_hdr(skb);
546
547 if (skb->ip_summed == CHECKSUM_PARTIAL) {
548 th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0);
549 skb->csum_start = skb_transport_header(skb) - skb->head;
550 skb->csum_offset = offsetof(struct tcphdr, check);
551 } else {
552 th->check = tcp_v4_check(skb->len, saddr, daddr,
553 csum_partial(th,
554 th->doff << 2,
555 skb->csum));
556 }
557 }
558
559 /* This routine computes an IPv4 TCP checksum. */
560 void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
561 {
562 const struct inet_sock *inet = inet_sk(sk);
563
564 __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
565 }
566 EXPORT_SYMBOL(tcp_v4_send_check);
567
568 int tcp_v4_gso_send_check(struct sk_buff *skb)
569 {
570 const struct iphdr *iph;
571 struct tcphdr *th;
572
573 if (!pskb_may_pull(skb, sizeof(*th)))
574 return -EINVAL;
575
576 iph = ip_hdr(skb);
577 th = tcp_hdr(skb);
578
579 th->check = 0;
580 skb->ip_summed = CHECKSUM_PARTIAL;
581 __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
582 return 0;
583 }
584
585 /*
586 * This routine will send an RST to the other tcp.
587 *
588 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
589 * for reset.
590 * Answer: if a packet caused RST, it is not for a socket
591 * existing in our system, if it is matched to a socket,
592 * it is just duplicate segment or bug in other side's TCP.
593 * So that we build reply only basing on parameters
594 * arrived with segment.
595 * Exception: precedence violation. We do not implement it in any case.
596 */
597
598 static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
599 {
600 const struct tcphdr *th = tcp_hdr(skb);
601 struct {
602 struct tcphdr th;
603 #ifdef CONFIG_TCP_MD5SIG
604 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
605 #endif
606 } rep;
607 struct ip_reply_arg arg;
608 #ifdef CONFIG_TCP_MD5SIG
609 struct tcp_md5sig_key *key;
610 const __u8 *hash_location = NULL;
611 unsigned char newhash[16];
612 int genhash;
613 struct sock *sk1 = NULL;
614 #endif
615 struct net *net;
616
617 /* Never send a reset in response to a reset. */
618 if (th->rst)
619 return;
620
621 if (skb_rtable(skb)->rt_type != RTN_LOCAL)
622 return;
623
624 /* Swap the send and the receive. */
625 memset(&rep, 0, sizeof(rep));
626 rep.th.dest = th->source;
627 rep.th.source = th->dest;
628 rep.th.doff = sizeof(struct tcphdr) / 4;
629 rep.th.rst = 1;
630
631 if (th->ack) {
632 rep.th.seq = th->ack_seq;
633 } else {
634 rep.th.ack = 1;
635 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
636 skb->len - (th->doff << 2));
637 }
638
639 memset(&arg, 0, sizeof(arg));
640 arg.iov[0].iov_base = (unsigned char *)&rep;
641 arg.iov[0].iov_len = sizeof(rep.th);
642
643 #ifdef CONFIG_TCP_MD5SIG
644 hash_location = tcp_parse_md5sig_option(th);
645 if (!sk && hash_location) {
646 /*
647 * active side is lost. Try to find listening socket through
648 * source port, and then find md5 key through listening socket.
649 * we are not loose security here:
650 * Incoming packet is checked with md5 hash with finding key,
651 * no RST generated if md5 hash doesn't match.
652 */
653 sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
654 &tcp_hashinfo, ip_hdr(skb)->daddr,
655 ntohs(th->source), inet_iif(skb));
656 /* don't send rst if it can't find key */
657 if (!sk1)
658 return;
659 rcu_read_lock();
660 key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *)
661 &ip_hdr(skb)->saddr, AF_INET);
662 if (!key)
663 goto release_sk1;
664
665 genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb);
666 if (genhash || memcmp(hash_location, newhash, 16) != 0)
667 goto release_sk1;
668 } else {
669 key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *)
670 &ip_hdr(skb)->saddr,
671 AF_INET) : NULL;
672 }
673
674 if (key) {
675 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
676 (TCPOPT_NOP << 16) |
677 (TCPOPT_MD5SIG << 8) |
678 TCPOLEN_MD5SIG);
679 /* Update length and the length the header thinks exists */
680 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
681 rep.th.doff = arg.iov[0].iov_len / 4;
682
683 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
684 key, ip_hdr(skb)->saddr,
685 ip_hdr(skb)->daddr, &rep.th);
686 }
687 #endif
688 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
689 ip_hdr(skb)->saddr, /* XXX */
690 arg.iov[0].iov_len, IPPROTO_TCP, 0);
691 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
692 arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
693 /* When socket is gone, all binding information is lost.
694 * routing might fail in this case. using iif for oif to
695 * make sure we can deliver it
696 */
697 arg.bound_dev_if = sk ? sk->sk_bound_dev_if : inet_iif(skb);
698
699 net = dev_net(skb_dst(skb)->dev);
700 arg.tos = ip_hdr(skb)->tos;
701 ip_send_unicast_reply(net, skb, ip_hdr(skb)->saddr,
702 ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
703
704 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
705 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
706
707 #ifdef CONFIG_TCP_MD5SIG
708 release_sk1:
709 if (sk1) {
710 rcu_read_unlock();
711 sock_put(sk1);
712 }
713 #endif
714 }
715
716 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
717 outside socket context is ugly, certainly. What can I do?
718 */
719
720 static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
721 u32 win, u32 ts, int oif,
722 struct tcp_md5sig_key *key,
723 int reply_flags, u8 tos)
724 {
725 const struct tcphdr *th = tcp_hdr(skb);
726 struct {
727 struct tcphdr th;
728 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
729 #ifdef CONFIG_TCP_MD5SIG
730 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
731 #endif
732 ];
733 } rep;
734 struct ip_reply_arg arg;
735 struct net *net = dev_net(skb_dst(skb)->dev);
736
737 memset(&rep.th, 0, sizeof(struct tcphdr));
738 memset(&arg, 0, sizeof(arg));
739
740 arg.iov[0].iov_base = (unsigned char *)&rep;
741 arg.iov[0].iov_len = sizeof(rep.th);
742 if (ts) {
743 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
744 (TCPOPT_TIMESTAMP << 8) |
745 TCPOLEN_TIMESTAMP);
746 rep.opt[1] = htonl(tcp_time_stamp);
747 rep.opt[2] = htonl(ts);
748 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
749 }
750
751 /* Swap the send and the receive. */
752 rep.th.dest = th->source;
753 rep.th.source = th->dest;
754 rep.th.doff = arg.iov[0].iov_len / 4;
755 rep.th.seq = htonl(seq);
756 rep.th.ack_seq = htonl(ack);
757 rep.th.ack = 1;
758 rep.th.window = htons(win);
759
760 #ifdef CONFIG_TCP_MD5SIG
761 if (key) {
762 int offset = (ts) ? 3 : 0;
763
764 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
765 (TCPOPT_NOP << 16) |
766 (TCPOPT_MD5SIG << 8) |
767 TCPOLEN_MD5SIG);
768 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
769 rep.th.doff = arg.iov[0].iov_len/4;
770
771 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
772 key, ip_hdr(skb)->saddr,
773 ip_hdr(skb)->daddr, &rep.th);
774 }
775 #endif
776 arg.flags = reply_flags;
777 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
778 ip_hdr(skb)->saddr, /* XXX */
779 arg.iov[0].iov_len, IPPROTO_TCP, 0);
780 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
781 if (oif)
782 arg.bound_dev_if = oif;
783 arg.tos = tos;
784 ip_send_unicast_reply(net, skb, ip_hdr(skb)->saddr,
785 ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
786
787 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
788 }
789
790 static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
791 {
792 struct inet_timewait_sock *tw = inet_twsk(sk);
793 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
794
795 tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
796 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
797 tcptw->tw_ts_recent,
798 tw->tw_bound_dev_if,
799 tcp_twsk_md5_key(tcptw),
800 tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
801 tw->tw_tos
802 );
803
804 inet_twsk_put(tw);
805 }
806
807 static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
808 struct request_sock *req)
809 {
810 tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
811 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
812 req->ts_recent,
813 0,
814 tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr,
815 AF_INET),
816 inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
817 ip_hdr(skb)->tos);
818 }
819
820 /*
821 * Send a SYN-ACK after having received a SYN.
822 * This still operates on a request_sock only, not on a big
823 * socket.
824 */
825 static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
826 struct request_sock *req,
827 struct request_values *rvp,
828 u16 queue_mapping,
829 bool nocache)
830 {
831 const struct inet_request_sock *ireq = inet_rsk(req);
832 struct flowi4 fl4;
833 int err = -1;
834 struct sk_buff * skb;
835
836 /* First, grab a route. */
837 if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL)
838 return -1;
839
840 skb = tcp_make_synack(sk, dst, req, rvp);
841
842 if (skb) {
843 __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);
844
845 skb_set_queue_mapping(skb, queue_mapping);
846 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
847 ireq->rmt_addr,
848 ireq->opt);
849 err = net_xmit_eval(err);
850 }
851
852 return err;
853 }
854
855 static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req,
856 struct request_values *rvp)
857 {
858 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
859 return tcp_v4_send_synack(sk, NULL, req, rvp, 0, false);
860 }
861
862 /*
863 * IPv4 request_sock destructor.
864 */
865 static void tcp_v4_reqsk_destructor(struct request_sock *req)
866 {
867 kfree(inet_rsk(req)->opt);
868 }
869
870 /*
871 * Return true if a syncookie should be sent
872 */
873 bool tcp_syn_flood_action(struct sock *sk,
874 const struct sk_buff *skb,
875 const char *proto)
876 {
877 const char *msg = "Dropping request";
878 bool want_cookie = false;
879 struct listen_sock *lopt;
880
881
882
883 #ifdef CONFIG_SYN_COOKIES
884 if (sysctl_tcp_syncookies) {
885 msg = "Sending cookies";
886 want_cookie = true;
887 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES);
888 } else
889 #endif
890 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP);
891
892 lopt = inet_csk(sk)->icsk_accept_queue.listen_opt;
893 if (!lopt->synflood_warned) {
894 lopt->synflood_warned = 1;
895 pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
896 proto, ntohs(tcp_hdr(skb)->dest), msg);
897 }
898 return want_cookie;
899 }
900 EXPORT_SYMBOL(tcp_syn_flood_action);
901
902 /*
903 * Save and compile IPv4 options into the request_sock if needed.
904 */
905 static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
906 struct sk_buff *skb)
907 {
908 const struct ip_options *opt = &(IPCB(skb)->opt);
909 struct ip_options_rcu *dopt = NULL;
910
911 if (opt && opt->optlen) {
912 int opt_size = sizeof(*dopt) + opt->optlen;
913
914 dopt = kmalloc(opt_size, GFP_ATOMIC);
915 if (dopt) {
916 if (ip_options_echo(&dopt->opt, skb)) {
917 kfree(dopt);
918 dopt = NULL;
919 }
920 }
921 }
922 return dopt;
923 }
924
925 #ifdef CONFIG_TCP_MD5SIG
926 /*
927 * RFC2385 MD5 checksumming requires a mapping of
928 * IP address->MD5 Key.
929 * We need to maintain these in the sk structure.
930 */
931
932 /* Find the Key structure for an address. */
933 struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
934 const union tcp_md5_addr *addr,
935 int family)
936 {
937 struct tcp_sock *tp = tcp_sk(sk);
938 struct tcp_md5sig_key *key;
939 struct hlist_node *pos;
940 unsigned int size = sizeof(struct in_addr);
941 struct tcp_md5sig_info *md5sig;
942
943 /* caller either holds rcu_read_lock() or socket lock */
944 md5sig = rcu_dereference_check(tp->md5sig_info,
945 sock_owned_by_user(sk) ||
946 lockdep_is_held(&sk->sk_lock.slock));
947 if (!md5sig)
948 return NULL;
949 #if IS_ENABLED(CONFIG_IPV6)
950 if (family == AF_INET6)
951 size = sizeof(struct in6_addr);
952 #endif
953 hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) {
954 if (key->family != family)
955 continue;
956 if (!memcmp(&key->addr, addr, size))
957 return key;
958 }
959 return NULL;
960 }
961 EXPORT_SYMBOL(tcp_md5_do_lookup);
962
963 struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
964 struct sock *addr_sk)
965 {
966 union tcp_md5_addr *addr;
967
968 addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_daddr;
969 return tcp_md5_do_lookup(sk, addr, AF_INET);
970 }
971 EXPORT_SYMBOL(tcp_v4_md5_lookup);
972
973 static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
974 struct request_sock *req)
975 {
976 union tcp_md5_addr *addr;
977
978 addr = (union tcp_md5_addr *)&inet_rsk(req)->rmt_addr;
979 return tcp_md5_do_lookup(sk, addr, AF_INET);
980 }
981
982 /* This can be called on a newly created socket, from other files */
983 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
984 int family, const u8 *newkey, u8 newkeylen, gfp_t gfp)
985 {
986 /* Add Key to the list */
987 struct tcp_md5sig_key *key;
988 struct tcp_sock *tp = tcp_sk(sk);
989 struct tcp_md5sig_info *md5sig;
990
991 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
992 if (key) {
993 /* Pre-existing entry - just update that one. */
994 memcpy(key->key, newkey, newkeylen);
995 key->keylen = newkeylen;
996 return 0;
997 }
998
999 md5sig = rcu_dereference_protected(tp->md5sig_info,
1000 sock_owned_by_user(sk));
1001 if (!md5sig) {
1002 md5sig = kmalloc(sizeof(*md5sig), gfp);
1003 if (!md5sig)
1004 return -ENOMEM;
1005
1006 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
1007 INIT_HLIST_HEAD(&md5sig->head);
1008 rcu_assign_pointer(tp->md5sig_info, md5sig);
1009 }
1010
1011 key = sock_kmalloc(sk, sizeof(*key), gfp);
1012 if (!key)
1013 return -ENOMEM;
1014 if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) {
1015 sock_kfree_s(sk, key, sizeof(*key));
1016 return -ENOMEM;
1017 }
1018
1019 memcpy(key->key, newkey, newkeylen);
1020 key->keylen = newkeylen;
1021 key->family = family;
1022 memcpy(&key->addr, addr,
1023 (family == AF_INET6) ? sizeof(struct in6_addr) :
1024 sizeof(struct in_addr));
1025 hlist_add_head_rcu(&key->node, &md5sig->head);
1026 return 0;
1027 }
1028 EXPORT_SYMBOL(tcp_md5_do_add);
1029
1030 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family)
1031 {
1032 struct tcp_sock *tp = tcp_sk(sk);
1033 struct tcp_md5sig_key *key;
1034 struct tcp_md5sig_info *md5sig;
1035
1036 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
1037 if (!key)
1038 return -ENOENT;
1039 hlist_del_rcu(&key->node);
1040 atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
1041 kfree_rcu(key, rcu);
1042 md5sig = rcu_dereference_protected(tp->md5sig_info,
1043 sock_owned_by_user(sk));
1044 if (hlist_empty(&md5sig->head))
1045 tcp_free_md5sig_pool();
1046 return 0;
1047 }
1048 EXPORT_SYMBOL(tcp_md5_do_del);
1049
1050 void tcp_clear_md5_list(struct sock *sk)
1051 {
1052 struct tcp_sock *tp = tcp_sk(sk);
1053 struct tcp_md5sig_key *key;
1054 struct hlist_node *pos, *n;
1055 struct tcp_md5sig_info *md5sig;
1056
1057 md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
1058
1059 if (!hlist_empty(&md5sig->head))
1060 tcp_free_md5sig_pool();
1061 hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) {
1062 hlist_del_rcu(&key->node);
1063 atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
1064 kfree_rcu(key, rcu);
1065 }
1066 }
1067
1068 static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
1069 int optlen)
1070 {
1071 struct tcp_md5sig cmd;
1072 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
1073
1074 if (optlen < sizeof(cmd))
1075 return -EINVAL;
1076
1077 if (copy_from_user(&cmd, optval, sizeof(cmd)))
1078 return -EFAULT;
1079
1080 if (sin->sin_family != AF_INET)
1081 return -EINVAL;
1082
1083 if (!cmd.tcpm_key || !cmd.tcpm_keylen)
1084 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
1085 AF_INET);
1086
1087 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
1088 return -EINVAL;
1089
1090 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
1091 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen,
1092 GFP_KERNEL);
1093 }
1094
1095 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
1096 __be32 daddr, __be32 saddr, int nbytes)
1097 {
1098 struct tcp4_pseudohdr *bp;
1099 struct scatterlist sg;
1100
1101 bp = &hp->md5_blk.ip4;
1102
1103 /*
1104 * 1. the TCP pseudo-header (in the order: source IP address,
1105 * destination IP address, zero-padded protocol number, and
1106 * segment length)
1107 */
1108 bp->saddr = saddr;
1109 bp->daddr = daddr;
1110 bp->pad = 0;
1111 bp->protocol = IPPROTO_TCP;
1112 bp->len = cpu_to_be16(nbytes);
1113
1114 sg_init_one(&sg, bp, sizeof(*bp));
1115 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
1116 }
1117
1118 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
1119 __be32 daddr, __be32 saddr, const struct tcphdr *th)
1120 {
1121 struct tcp_md5sig_pool *hp;
1122 struct hash_desc *desc;
1123
1124 hp = tcp_get_md5sig_pool();
1125 if (!hp)
1126 goto clear_hash_noput;
1127 desc = &hp->md5_desc;
1128
1129 if (crypto_hash_init(desc))
1130 goto clear_hash;
1131 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
1132 goto clear_hash;
1133 if (tcp_md5_hash_header(hp, th))
1134 goto clear_hash;
1135 if (tcp_md5_hash_key(hp, key))
1136 goto clear_hash;
1137 if (crypto_hash_final(desc, md5_hash))
1138 goto clear_hash;
1139
1140 tcp_put_md5sig_pool();
1141 return 0;
1142
1143 clear_hash:
1144 tcp_put_md5sig_pool();
1145 clear_hash_noput:
1146 memset(md5_hash, 0, 16);
1147 return 1;
1148 }
1149
1150 int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
1151 const struct sock *sk, const struct request_sock *req,
1152 const struct sk_buff *skb)
1153 {
1154 struct tcp_md5sig_pool *hp;
1155 struct hash_desc *desc;
1156 const struct tcphdr *th = tcp_hdr(skb);
1157 __be32 saddr, daddr;
1158
1159 if (sk) {
1160 saddr = inet_sk(sk)->inet_saddr;
1161 daddr = inet_sk(sk)->inet_daddr;
1162 } else if (req) {
1163 saddr = inet_rsk(req)->loc_addr;
1164 daddr = inet_rsk(req)->rmt_addr;
1165 } else {
1166 const struct iphdr *iph = ip_hdr(skb);
1167 saddr = iph->saddr;
1168 daddr = iph->daddr;
1169 }
1170
1171 hp = tcp_get_md5sig_pool();
1172 if (!hp)
1173 goto clear_hash_noput;
1174 desc = &hp->md5_desc;
1175
1176 if (crypto_hash_init(desc))
1177 goto clear_hash;
1178
1179 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
1180 goto clear_hash;
1181 if (tcp_md5_hash_header(hp, th))
1182 goto clear_hash;
1183 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
1184 goto clear_hash;
1185 if (tcp_md5_hash_key(hp, key))
1186 goto clear_hash;
1187 if (crypto_hash_final(desc, md5_hash))
1188 goto clear_hash;
1189
1190 tcp_put_md5sig_pool();
1191 return 0;
1192
1193 clear_hash:
1194 tcp_put_md5sig_pool();
1195 clear_hash_noput:
1196 memset(md5_hash, 0, 16);
1197 return 1;
1198 }
1199 EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
1200
1201 static bool tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
1202 {
1203 /*
1204 * This gets called for each TCP segment that arrives
1205 * so we want to be efficient.
1206 * We have 3 drop cases:
1207 * o No MD5 hash and one expected.
1208 * o MD5 hash and we're not expecting one.
1209 * o MD5 hash and its wrong.
1210 */
1211 const __u8 *hash_location = NULL;
1212 struct tcp_md5sig_key *hash_expected;
1213 const struct iphdr *iph = ip_hdr(skb);
1214 const struct tcphdr *th = tcp_hdr(skb);
1215 int genhash;
1216 unsigned char newhash[16];
1217
1218 hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr,
1219 AF_INET);
1220 hash_location = tcp_parse_md5sig_option(th);
1221
1222 /* We've parsed the options - do we have a hash? */
1223 if (!hash_expected && !hash_location)
1224 return false;
1225
1226 if (hash_expected && !hash_location) {
1227 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
1228 return true;
1229 }
1230
1231 if (!hash_expected && hash_location) {
1232 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
1233 return true;
1234 }
1235
1236 /* Okay, so this is hash_expected and hash_location -
1237 * so we need to calculate the checksum.
1238 */
1239 genhash = tcp_v4_md5_hash_skb(newhash,
1240 hash_expected,
1241 NULL, NULL, skb);
1242
1243 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1244 net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1245 &iph->saddr, ntohs(th->source),
1246 &iph->daddr, ntohs(th->dest),
1247 genhash ? " tcp_v4_calc_md5_hash failed"
1248 : "");
1249 return true;
1250 }
1251 return false;
1252 }
1253
1254 #endif
1255
1256 struct request_sock_ops tcp_request_sock_ops __read_mostly = {
1257 .family = PF_INET,
1258 .obj_size = sizeof(struct tcp_request_sock),
1259 .rtx_syn_ack = tcp_v4_rtx_synack,
1260 .send_ack = tcp_v4_reqsk_send_ack,
1261 .destructor = tcp_v4_reqsk_destructor,
1262 .send_reset = tcp_v4_send_reset,
1263 .syn_ack_timeout = tcp_syn_ack_timeout,
1264 };
1265
1266 #ifdef CONFIG_TCP_MD5SIG
1267 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
1268 .md5_lookup = tcp_v4_reqsk_md5_lookup,
1269 .calc_md5_hash = tcp_v4_md5_hash_skb,
1270 };
1271 #endif
1272
1273 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1274 {
1275 struct tcp_extend_values tmp_ext;
1276 struct tcp_options_received tmp_opt;
1277 const u8 *hash_location;
1278 struct request_sock *req;
1279 struct inet_request_sock *ireq;
1280 struct tcp_sock *tp = tcp_sk(sk);
1281 struct dst_entry *dst = NULL;
1282 __be32 saddr = ip_hdr(skb)->saddr;
1283 __be32 daddr = ip_hdr(skb)->daddr;
1284 __u32 isn = TCP_SKB_CB(skb)->when;
1285 bool want_cookie = false;
1286
1287 /* Never answer to SYNs send to broadcast or multicast */
1288 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
1289 goto drop;
1290
1291 /* TW buckets are converted to open requests without
1292 * limitations, they conserve resources and peer is
1293 * evidently real one.
1294 */
1295 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1296 want_cookie = tcp_syn_flood_action(sk, skb, "TCP");
1297 if (!want_cookie)
1298 goto drop;
1299 }
1300
1301 /* Accept backlog is full. If we have already queued enough
1302 * of warm entries in syn queue, drop request. It is better than
1303 * clogging syn queue with openreqs with exponentially increasing
1304 * timeout.
1305 */
1306 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1307 goto drop;
1308
1309 req = inet_reqsk_alloc(&tcp_request_sock_ops);
1310 if (!req)
1311 goto drop;
1312
1313 #ifdef CONFIG_TCP_MD5SIG
1314 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1315 #endif
1316
1317 tcp_clear_options(&tmp_opt);
1318 tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
1319 tmp_opt.user_mss = tp->rx_opt.user_mss;
1320 tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);
1321
1322 if (tmp_opt.cookie_plus > 0 &&
1323 tmp_opt.saw_tstamp &&
1324 !tp->rx_opt.cookie_out_never &&
1325 (sysctl_tcp_cookie_size > 0 ||
1326 (tp->cookie_values != NULL &&
1327 tp->cookie_values->cookie_desired > 0))) {
1328 u8 *c;
1329 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1330 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1331
1332 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1333 goto drop_and_release;
1334
1335 /* Secret recipe starts with IP addresses */
1336 *mess++ ^= (__force u32)daddr;
1337 *mess++ ^= (__force u32)saddr;
1338
1339 /* plus variable length Initiator Cookie */
1340 c = (u8 *)mess;
1341 while (l-- > 0)
1342 *c++ ^= *hash_location++;
1343
1344 want_cookie = false; /* not our kind of cookie */
1345 tmp_ext.cookie_out_never = 0; /* false */
1346 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1347 } else if (!tp->rx_opt.cookie_in_always) {
1348 /* redundant indications, but ensure initialization. */
1349 tmp_ext.cookie_out_never = 1; /* true */
1350 tmp_ext.cookie_plus = 0;
1351 } else {
1352 goto drop_and_release;
1353 }
1354 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1355
1356 if (want_cookie && !tmp_opt.saw_tstamp)
1357 tcp_clear_options(&tmp_opt);
1358
1359 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1360 tcp_openreq_init(req, &tmp_opt, skb);
1361
1362 ireq = inet_rsk(req);
1363 ireq->loc_addr = daddr;
1364 ireq->rmt_addr = saddr;
1365 ireq->no_srccheck = inet_sk(sk)->transparent;
1366 ireq->opt = tcp_v4_save_options(sk, skb);
1367
1368 if (security_inet_conn_request(sk, skb, req))
1369 goto drop_and_free;
1370
1371 if (!want_cookie || tmp_opt.tstamp_ok)
1372 TCP_ECN_create_request(req, skb);
1373
1374 if (want_cookie) {
1375 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1376 req->cookie_ts = tmp_opt.tstamp_ok;
1377 } else if (!isn) {
1378 struct flowi4 fl4;
1379
1380 /* VJ's idea. We save last timestamp seen
1381 * from the destination in peer table, when entering
1382 * state TIME-WAIT, and check against it before
1383 * accepting new connection request.
1384 *
1385 * If "isn" is not zero, this request hit alive
1386 * timewait bucket, so that all the necessary checks
1387 * are made in the function processing timewait state.
1388 */
1389 if (tmp_opt.saw_tstamp &&
1390 tcp_death_row.sysctl_tw_recycle &&
1391 (dst = inet_csk_route_req(sk, &fl4, req)) != NULL &&
1392 fl4.daddr == saddr) {
1393 if (!tcp_peer_is_proven(req, dst, true)) {
1394 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1395 goto drop_and_release;
1396 }
1397 }
1398 /* Kill the following clause, if you dislike this way. */
1399 else if (!sysctl_tcp_syncookies &&
1400 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1401 (sysctl_max_syn_backlog >> 2)) &&
1402 !tcp_peer_is_proven(req, dst, false)) {
1403 /* Without syncookies last quarter of
1404 * backlog is filled with destinations,
1405 * proven to be alive.
1406 * It means that we continue to communicate
1407 * to destinations, already remembered
1408 * to the moment of synflood.
1409 */
1410 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"),
1411 &saddr, ntohs(tcp_hdr(skb)->source));
1412 goto drop_and_release;
1413 }
1414
1415 isn = tcp_v4_init_sequence(skb);
1416 }
1417 tcp_rsk(req)->snt_isn = isn;
1418 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1419
1420 if (tcp_v4_send_synack(sk, dst, req,
1421 (struct request_values *)&tmp_ext,
1422 skb_get_queue_mapping(skb),
1423 want_cookie) ||
1424 want_cookie)
1425 goto drop_and_free;
1426
1427 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1428 return 0;
1429
1430 drop_and_release:
1431 dst_release(dst);
1432 drop_and_free:
1433 reqsk_free(req);
1434 drop:
1435 return 0;
1436 }
1437 EXPORT_SYMBOL(tcp_v4_conn_request);
1438
1439
1440 /*
1441 * The three way handshake has completed - we got a valid synack -
1442 * now create the new socket.
1443 */
1444 struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1445 struct request_sock *req,
1446 struct dst_entry *dst)
1447 {
1448 struct inet_request_sock *ireq;
1449 struct inet_sock *newinet;
1450 struct tcp_sock *newtp;
1451 struct sock *newsk;
1452 #ifdef CONFIG_TCP_MD5SIG
1453 struct tcp_md5sig_key *key;
1454 #endif
1455 struct ip_options_rcu *inet_opt;
1456
1457 if (sk_acceptq_is_full(sk))
1458 goto exit_overflow;
1459
1460 newsk = tcp_create_openreq_child(sk, req, skb);
1461 if (!newsk)
1462 goto exit_nonewsk;
1463
1464 newsk->sk_gso_type = SKB_GSO_TCPV4;
1465
1466 newtp = tcp_sk(newsk);
1467 newinet = inet_sk(newsk);
1468 ireq = inet_rsk(req);
1469 newinet->inet_daddr = ireq->rmt_addr;
1470 newinet->inet_rcv_saddr = ireq->loc_addr;
1471 newinet->inet_saddr = ireq->loc_addr;
1472 inet_opt = ireq->opt;
1473 rcu_assign_pointer(newinet->inet_opt, inet_opt);
1474 ireq->opt = NULL;
1475 newinet->mc_index = inet_iif(skb);
1476 newinet->mc_ttl = ip_hdr(skb)->ttl;
1477 newinet->rcv_tos = ip_hdr(skb)->tos;
1478 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1479 if (inet_opt)
1480 inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
1481 newinet->inet_id = newtp->write_seq ^ jiffies;
1482
1483 if (!dst) {
1484 dst = inet_csk_route_child_sock(sk, newsk, req);
1485 if (!dst)
1486 goto put_and_exit;
1487 } else {
1488 /* syncookie case : see end of cookie_v4_check() */
1489 }
1490 sk_setup_caps(newsk, dst);
1491
1492 tcp_mtup_init(newsk);
1493 tcp_sync_mss(newsk, dst_mtu(dst));
1494 newtp->advmss = dst_metric_advmss(dst);
1495 if (tcp_sk(sk)->rx_opt.user_mss &&
1496 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1497 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1498
1499 tcp_initialize_rcv_mss(newsk);
1500 if (tcp_rsk(req)->snt_synack)
1501 tcp_valid_rtt_meas(newsk,
1502 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1503 newtp->total_retrans = req->retrans;
1504
1505 #ifdef CONFIG_TCP_MD5SIG
1506 /* Copy over the MD5 key from the original socket */
1507 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr,
1508 AF_INET);
1509 if (key != NULL) {
1510 /*
1511 * We're using one, so create a matching key
1512 * on the newsk structure. If we fail to get
1513 * memory, then we end up not copying the key
1514 * across. Shucks.
1515 */
1516 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr,
1517 AF_INET, key->key, key->keylen, GFP_ATOMIC);
1518 sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
1519 }
1520 #endif
1521
1522 if (__inet_inherit_port(sk, newsk) < 0)
1523 goto put_and_exit;
1524 __inet_hash_nolisten(newsk, NULL);
1525
1526 return newsk;
1527
1528 exit_overflow:
1529 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1530 exit_nonewsk:
1531 dst_release(dst);
1532 exit:
1533 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1534 return NULL;
1535 put_and_exit:
1536 tcp_clear_xmit_timers(newsk);
1537 tcp_cleanup_congestion_control(newsk);
1538 bh_unlock_sock(newsk);
1539 sock_put(newsk);
1540 goto exit;
1541 }
1542 EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
1543
1544 static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1545 {
1546 struct tcphdr *th = tcp_hdr(skb);
1547 const struct iphdr *iph = ip_hdr(skb);
1548 struct sock *nsk;
1549 struct request_sock **prev;
1550 /* Find possible connection requests. */
1551 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1552 iph->saddr, iph->daddr);
1553 if (req)
1554 return tcp_check_req(sk, skb, req, prev);
1555
1556 nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
1557 th->source, iph->daddr, th->dest, inet_iif(skb));
1558
1559 if (nsk) {
1560 if (nsk->sk_state != TCP_TIME_WAIT) {
1561 bh_lock_sock(nsk);
1562 return nsk;
1563 }
1564 inet_twsk_put(inet_twsk(nsk));
1565 return NULL;
1566 }
1567
1568 #ifdef CONFIG_SYN_COOKIES
1569 if (!th->syn)
1570 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1571 #endif
1572 return sk;
1573 }
1574
1575 static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
1576 {
1577 const struct iphdr *iph = ip_hdr(skb);
1578
1579 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1580 if (!tcp_v4_check(skb->len, iph->saddr,
1581 iph->daddr, skb->csum)) {
1582 skb->ip_summed = CHECKSUM_UNNECESSARY;
1583 return 0;
1584 }
1585 }
1586
1587 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1588 skb->len, IPPROTO_TCP, 0);
1589
1590 if (skb->len <= 76) {
1591 return __skb_checksum_complete(skb);
1592 }
1593 return 0;
1594 }
1595
1596
1597 /* The socket must have it's spinlock held when we get
1598 * here.
1599 *
1600 * We have a potential double-lock case here, so even when
1601 * doing backlog processing we use the BH locking scheme.
1602 * This is because we cannot sleep with the original spinlock
1603 * held.
1604 */
1605 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1606 {
1607 struct sock *rsk;
1608 #ifdef CONFIG_TCP_MD5SIG
1609 /*
1610 * We really want to reject the packet as early as possible
1611 * if:
1612 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1613 * o There is an MD5 option and we're not expecting one
1614 */
1615 if (tcp_v4_inbound_md5_hash(sk, skb))
1616 goto discard;
1617 #endif
1618
1619 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1620 struct dst_entry *dst = sk->sk_rx_dst;
1621
1622 sock_rps_save_rxhash(sk, skb);
1623 if (dst) {
1624 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1625 dst->ops->check(dst, 0) == NULL) {
1626 dst_release(dst);
1627 sk->sk_rx_dst = NULL;
1628 }
1629 }
1630 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
1631 rsk = sk;
1632 goto reset;
1633 }
1634 return 0;
1635 }
1636
1637 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1638 goto csum_err;
1639
1640 if (sk->sk_state == TCP_LISTEN) {
1641 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1642 if (!nsk)
1643 goto discard;
1644
1645 if (nsk != sk) {
1646 sock_rps_save_rxhash(nsk, skb);
1647 if (tcp_child_process(sk, nsk, skb)) {
1648 rsk = nsk;
1649 goto reset;
1650 }
1651 return 0;
1652 }
1653 } else
1654 sock_rps_save_rxhash(sk, skb);
1655
1656 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
1657 rsk = sk;
1658 goto reset;
1659 }
1660 return 0;
1661
1662 reset:
1663 tcp_v4_send_reset(rsk, skb);
1664 discard:
1665 kfree_skb(skb);
1666 /* Be careful here. If this function gets more complicated and
1667 * gcc suffers from register pressure on the x86, sk (in %ebx)
1668 * might be destroyed here. This current version compiles correctly,
1669 * but you have been warned.
1670 */
1671 return 0;
1672
1673 csum_err:
1674 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1675 goto discard;
1676 }
1677 EXPORT_SYMBOL(tcp_v4_do_rcv);
1678
1679 void tcp_v4_early_demux(struct sk_buff *skb)
1680 {
1681 struct net *net = dev_net(skb->dev);
1682 const struct iphdr *iph;
1683 const struct tcphdr *th;
1684 struct sock *sk;
1685
1686 if (skb->pkt_type != PACKET_HOST)
1687 return;
1688
1689 if (!pskb_may_pull(skb, ip_hdrlen(skb) + sizeof(struct tcphdr)))
1690 return;
1691
1692 iph = ip_hdr(skb);
1693 th = (struct tcphdr *) ((char *)iph + ip_hdrlen(skb));
1694
1695 if (th->doff < sizeof(struct tcphdr) / 4)
1696 return;
1697
1698 sk = __inet_lookup_established(net, &tcp_hashinfo,
1699 iph->saddr, th->source,
1700 iph->daddr, ntohs(th->dest),
1701 skb->skb_iif);
1702 if (sk) {
1703 skb->sk = sk;
1704 skb->destructor = sock_edemux;
1705 if (sk->sk_state != TCP_TIME_WAIT) {
1706 struct dst_entry *dst = sk->sk_rx_dst;
1707
1708 if (dst)
1709 dst = dst_check(dst, 0);
1710 if (dst &&
1711 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1712 skb_dst_set_noref(skb, dst);
1713 }
1714 }
1715 }
1716
1717 /*
1718 * From tcp_input.c
1719 */
1720
1721 int tcp_v4_rcv(struct sk_buff *skb)
1722 {
1723 const struct iphdr *iph;
1724 const struct tcphdr *th;
1725 struct sock *sk;
1726 int ret;
1727 struct net *net = dev_net(skb->dev);
1728
1729 if (skb->pkt_type != PACKET_HOST)
1730 goto discard_it;
1731
1732 /* Count it even if it's bad */
1733 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1734
1735 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1736 goto discard_it;
1737
1738 th = tcp_hdr(skb);
1739
1740 if (th->doff < sizeof(struct tcphdr) / 4)
1741 goto bad_packet;
1742 if (!pskb_may_pull(skb, th->doff * 4))
1743 goto discard_it;
1744
1745 /* An explanation is required here, I think.
1746 * Packet length and doff are validated by header prediction,
1747 * provided case of th->doff==0 is eliminated.
1748 * So, we defer the checks. */
1749 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
1750 goto bad_packet;
1751
1752 th = tcp_hdr(skb);
1753 iph = ip_hdr(skb);
1754 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1755 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1756 skb->len - th->doff * 4);
1757 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1758 TCP_SKB_CB(skb)->when = 0;
1759 TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
1760 TCP_SKB_CB(skb)->sacked = 0;
1761
1762 sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1763 if (!sk)
1764 goto no_tcp_socket;
1765
1766 process:
1767 if (sk->sk_state == TCP_TIME_WAIT)
1768 goto do_time_wait;
1769
1770 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
1771 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1772 goto discard_and_relse;
1773 }
1774
1775 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1776 goto discard_and_relse;
1777 nf_reset(skb);
1778
1779 if (sk_filter(sk, skb))
1780 goto discard_and_relse;
1781
1782 skb->dev = NULL;
1783
1784 bh_lock_sock_nested(sk);
1785 ret = 0;
1786 if (!sock_owned_by_user(sk)) {
1787 #ifdef CONFIG_NET_DMA
1788 struct tcp_sock *tp = tcp_sk(sk);
1789 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1790 tp->ucopy.dma_chan = net_dma_find_channel();
1791 if (tp->ucopy.dma_chan)
1792 ret = tcp_v4_do_rcv(sk, skb);
1793 else
1794 #endif
1795 {
1796 if (!tcp_prequeue(sk, skb))
1797 ret = tcp_v4_do_rcv(sk, skb);
1798 }
1799 } else if (unlikely(sk_add_backlog(sk, skb,
1800 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1801 bh_unlock_sock(sk);
1802 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1803 goto discard_and_relse;
1804 }
1805 bh_unlock_sock(sk);
1806
1807 sock_put(sk);
1808
1809 return ret;
1810
1811 no_tcp_socket:
1812 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1813 goto discard_it;
1814
1815 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1816 bad_packet:
1817 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1818 } else {
1819 tcp_v4_send_reset(NULL, skb);
1820 }
1821
1822 discard_it:
1823 /* Discard frame. */
1824 kfree_skb(skb);
1825 return 0;
1826
1827 discard_and_relse:
1828 sock_put(sk);
1829 goto discard_it;
1830
1831 do_time_wait:
1832 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1833 inet_twsk_put(inet_twsk(sk));
1834 goto discard_it;
1835 }
1836
1837 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1838 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1839 inet_twsk_put(inet_twsk(sk));
1840 goto discard_it;
1841 }
1842 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1843 case TCP_TW_SYN: {
1844 struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
1845 &tcp_hashinfo,
1846 iph->daddr, th->dest,
1847 inet_iif(skb));
1848 if (sk2) {
1849 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1850 inet_twsk_put(inet_twsk(sk));
1851 sk = sk2;
1852 goto process;
1853 }
1854 /* Fall through to ACK */
1855 }
1856 case TCP_TW_ACK:
1857 tcp_v4_timewait_ack(sk, skb);
1858 break;
1859 case TCP_TW_RST:
1860 goto no_tcp_socket;
1861 case TCP_TW_SUCCESS:;
1862 }
1863 goto discard_it;
1864 }
1865
1866 static struct timewait_sock_ops tcp_timewait_sock_ops = {
1867 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1868 .twsk_unique = tcp_twsk_unique,
1869 .twsk_destructor= tcp_twsk_destructor,
1870 };
1871
1872 void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
1873 {
1874 struct dst_entry *dst = skb_dst(skb);
1875
1876 dst_hold(dst);
1877 sk->sk_rx_dst = dst;
1878 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
1879 }
1880 EXPORT_SYMBOL(inet_sk_rx_dst_set);
1881
1882 const struct inet_connection_sock_af_ops ipv4_specific = {
1883 .queue_xmit = ip_queue_xmit,
1884 .send_check = tcp_v4_send_check,
1885 .rebuild_header = inet_sk_rebuild_header,
1886 .sk_rx_dst_set = inet_sk_rx_dst_set,
1887 .conn_request = tcp_v4_conn_request,
1888 .syn_recv_sock = tcp_v4_syn_recv_sock,
1889 .net_header_len = sizeof(struct iphdr),
1890 .setsockopt = ip_setsockopt,
1891 .getsockopt = ip_getsockopt,
1892 .addr2sockaddr = inet_csk_addr2sockaddr,
1893 .sockaddr_len = sizeof(struct sockaddr_in),
1894 .bind_conflict = inet_csk_bind_conflict,
1895 #ifdef CONFIG_COMPAT
1896 .compat_setsockopt = compat_ip_setsockopt,
1897 .compat_getsockopt = compat_ip_getsockopt,
1898 #endif
1899 };
1900 EXPORT_SYMBOL(ipv4_specific);
1901
1902 #ifdef CONFIG_TCP_MD5SIG
1903 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
1904 .md5_lookup = tcp_v4_md5_lookup,
1905 .calc_md5_hash = tcp_v4_md5_hash_skb,
1906 .md5_parse = tcp_v4_parse_md5_keys,
1907 };
1908 #endif
1909
1910 /* NOTE: A lot of things set to zero explicitly by call to
1911 * sk_alloc() so need not be done here.
1912 */
1913 static int tcp_v4_init_sock(struct sock *sk)
1914 {
1915 struct inet_connection_sock *icsk = inet_csk(sk);
1916
1917 tcp_init_sock(sk);
1918
1919 icsk->icsk_af_ops = &ipv4_specific;
1920
1921 #ifdef CONFIG_TCP_MD5SIG
1922 tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific;
1923 #endif
1924
1925 return 0;
1926 }
1927
1928 void tcp_v4_destroy_sock(struct sock *sk)
1929 {
1930 struct tcp_sock *tp = tcp_sk(sk);
1931
1932 tcp_clear_xmit_timers(sk);
1933
1934 tcp_cleanup_congestion_control(sk);
1935
1936 /* Cleanup up the write buffer. */
1937 tcp_write_queue_purge(sk);
1938
1939 /* Cleans up our, hopefully empty, out_of_order_queue. */
1940 __skb_queue_purge(&tp->out_of_order_queue);
1941
1942 #ifdef CONFIG_TCP_MD5SIG
1943 /* Clean up the MD5 key list, if any */
1944 if (tp->md5sig_info) {
1945 tcp_clear_md5_list(sk);
1946 kfree_rcu(tp->md5sig_info, rcu);
1947 tp->md5sig_info = NULL;
1948 }
1949 #endif
1950
1951 #ifdef CONFIG_NET_DMA
1952 /* Cleans up our sk_async_wait_queue */
1953 __skb_queue_purge(&sk->sk_async_wait_queue);
1954 #endif
1955
1956 /* Clean prequeue, it must be empty really */
1957 __skb_queue_purge(&tp->ucopy.prequeue);
1958
1959 /* Clean up a referenced TCP bind bucket. */
1960 if (inet_csk(sk)->icsk_bind_hash)
1961 inet_put_port(sk);
1962
1963 /*
1964 * If sendmsg cached page exists, toss it.
1965 */
1966 if (sk->sk_sndmsg_page) {
1967 __free_page(sk->sk_sndmsg_page);
1968 sk->sk_sndmsg_page = NULL;
1969 }
1970
1971 /* TCP Cookie Transactions */
1972 if (tp->cookie_values != NULL) {
1973 kref_put(&tp->cookie_values->kref,
1974 tcp_cookie_values_release);
1975 tp->cookie_values = NULL;
1976 }
1977
1978 /* If socket is aborted during connect operation */
1979 tcp_free_fastopen_req(tp);
1980
1981 sk_sockets_allocated_dec(sk);
1982 sock_release_memcg(sk);
1983 }
1984 EXPORT_SYMBOL(tcp_v4_destroy_sock);
1985
1986 #ifdef CONFIG_PROC_FS
1987 /* Proc filesystem TCP sock list dumping. */
1988
1989 static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
1990 {
1991 return hlist_nulls_empty(head) ? NULL :
1992 list_entry(head->first, struct inet_timewait_sock, tw_node);
1993 }
1994
1995 static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
1996 {
1997 return !is_a_nulls(tw->tw_node.next) ?
1998 hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
1999 }
2000
2001 /*
2002 * Get next listener socket follow cur. If cur is NULL, get first socket
2003 * starting from bucket given in st->bucket; when st->bucket is zero the
2004 * very first socket in the hash table is returned.
2005 */
2006 static void *listening_get_next(struct seq_file *seq, void *cur)
2007 {
2008 struct inet_connection_sock *icsk;
2009 struct hlist_nulls_node *node;
2010 struct sock *sk = cur;
2011 struct inet_listen_hashbucket *ilb;
2012 struct tcp_iter_state *st = seq->private;
2013 struct net *net = seq_file_net(seq);
2014
2015 if (!sk) {
2016 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2017 spin_lock_bh(&ilb->lock);
2018 sk = sk_nulls_head(&ilb->head);
2019 st->offset = 0;
2020 goto get_sk;
2021 }
2022 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2023 ++st->num;
2024 ++st->offset;
2025
2026 if (st->state == TCP_SEQ_STATE_OPENREQ) {
2027 struct request_sock *req = cur;
2028
2029 icsk = inet_csk(st->syn_wait_sk);
2030 req = req->dl_next;
2031 while (1) {
2032 while (req) {
2033 if (req->rsk_ops->family == st->family) {
2034 cur = req;
2035 goto out;
2036 }
2037 req = req->dl_next;
2038 }
2039 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
2040 break;
2041 get_req:
2042 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
2043 }
2044 sk = sk_nulls_next(st->syn_wait_sk);
2045 st->state = TCP_SEQ_STATE_LISTENING;
2046 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2047 } else {
2048 icsk = inet_csk(sk);
2049 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2050 if (reqsk_queue_len(&icsk->icsk_accept_queue))
2051 goto start_req;
2052 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2053 sk = sk_nulls_next(sk);
2054 }
2055 get_sk:
2056 sk_nulls_for_each_from(sk, node) {
2057 if (!net_eq(sock_net(sk), net))
2058 continue;
2059 if (sk->sk_family == st->family) {
2060 cur = sk;
2061 goto out;
2062 }
2063 icsk = inet_csk(sk);
2064 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2065 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
2066 start_req:
2067 st->uid = sock_i_uid(sk);
2068 st->syn_wait_sk = sk;
2069 st->state = TCP_SEQ_STATE_OPENREQ;
2070 st->sbucket = 0;
2071 goto get_req;
2072 }
2073 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2074 }
2075 spin_unlock_bh(&ilb->lock);
2076 st->offset = 0;
2077 if (++st->bucket < INET_LHTABLE_SIZE) {
2078 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2079 spin_lock_bh(&ilb->lock);
2080 sk = sk_nulls_head(&ilb->head);
2081 goto get_sk;
2082 }
2083 cur = NULL;
2084 out:
2085 return cur;
2086 }
2087
2088 static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
2089 {
2090 struct tcp_iter_state *st = seq->private;
2091 void *rc;
2092
2093 st->bucket = 0;
2094 st->offset = 0;
2095 rc = listening_get_next(seq, NULL);
2096
2097 while (rc && *pos) {
2098 rc = listening_get_next(seq, rc);
2099 --*pos;
2100 }
2101 return rc;
2102 }
2103
2104 static inline bool empty_bucket(struct tcp_iter_state *st)
2105 {
2106 return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
2107 hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
2108 }
2109
2110 /*
2111 * Get first established socket starting from bucket given in st->bucket.
2112 * If st->bucket is zero, the very first socket in the hash is returned.
2113 */
2114 static void *established_get_first(struct seq_file *seq)
2115 {
2116 struct tcp_iter_state *st = seq->private;
2117 struct net *net = seq_file_net(seq);
2118 void *rc = NULL;
2119
2120 st->offset = 0;
2121 for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
2122 struct sock *sk;
2123 struct hlist_nulls_node *node;
2124 struct inet_timewait_sock *tw;
2125 spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
2126
2127 /* Lockless fast path for the common case of empty buckets */
2128 if (empty_bucket(st))
2129 continue;
2130
2131 spin_lock_bh(lock);
2132 sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
2133 if (sk->sk_family != st->family ||
2134 !net_eq(sock_net(sk), net)) {
2135 continue;
2136 }
2137 rc = sk;
2138 goto out;
2139 }
2140 st->state = TCP_SEQ_STATE_TIME_WAIT;
2141 inet_twsk_for_each(tw, node,
2142 &tcp_hashinfo.ehash[st->bucket].twchain) {
2143 if (tw->tw_family != st->family ||
2144 !net_eq(twsk_net(tw), net)) {
2145 continue;
2146 }
2147 rc = tw;
2148 goto out;
2149 }
2150 spin_unlock_bh(lock);
2151 st->state = TCP_SEQ_STATE_ESTABLISHED;
2152 }
2153 out:
2154 return rc;
2155 }
2156
2157 static void *established_get_next(struct seq_file *seq, void *cur)
2158 {
2159 struct sock *sk = cur;
2160 struct inet_timewait_sock *tw;
2161 struct hlist_nulls_node *node;
2162 struct tcp_iter_state *st = seq->private;
2163 struct net *net = seq_file_net(seq);
2164
2165 ++st->num;
2166 ++st->offset;
2167
2168 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2169 tw = cur;
2170 tw = tw_next(tw);
2171 get_tw:
2172 while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
2173 tw = tw_next(tw);
2174 }
2175 if (tw) {
2176 cur = tw;
2177 goto out;
2178 }
2179 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2180 st->state = TCP_SEQ_STATE_ESTABLISHED;
2181
2182 /* Look for next non empty bucket */
2183 st->offset = 0;
2184 while (++st->bucket <= tcp_hashinfo.ehash_mask &&
2185 empty_bucket(st))
2186 ;
2187 if (st->bucket > tcp_hashinfo.ehash_mask)
2188 return NULL;
2189
2190 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2191 sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
2192 } else
2193 sk = sk_nulls_next(sk);
2194
2195 sk_nulls_for_each_from(sk, node) {
2196 if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
2197 goto found;
2198 }
2199
2200 st->state = TCP_SEQ_STATE_TIME_WAIT;
2201 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
2202 goto get_tw;
2203 found:
2204 cur = sk;
2205 out:
2206 return cur;
2207 }
2208
2209 static void *established_get_idx(struct seq_file *seq, loff_t pos)
2210 {
2211 struct tcp_iter_state *st = seq->private;
2212 void *rc;
2213
2214 st->bucket = 0;
2215 rc = established_get_first(seq);
2216
2217 while (rc && pos) {
2218 rc = established_get_next(seq, rc);
2219 --pos;
2220 }
2221 return rc;
2222 }
2223
2224 static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2225 {
2226 void *rc;
2227 struct tcp_iter_state *st = seq->private;
2228
2229 st->state = TCP_SEQ_STATE_LISTENING;
2230 rc = listening_get_idx(seq, &pos);
2231
2232 if (!rc) {
2233 st->state = TCP_SEQ_STATE_ESTABLISHED;
2234 rc = established_get_idx(seq, pos);
2235 }
2236
2237 return rc;
2238 }
2239
2240 static void *tcp_seek_last_pos(struct seq_file *seq)
2241 {
2242 struct tcp_iter_state *st = seq->private;
2243 int offset = st->offset;
2244 int orig_num = st->num;
2245 void *rc = NULL;
2246
2247 switch (st->state) {
2248 case TCP_SEQ_STATE_OPENREQ:
2249 case TCP_SEQ_STATE_LISTENING:
2250 if (st->bucket >= INET_LHTABLE_SIZE)
2251 break;
2252 st->state = TCP_SEQ_STATE_LISTENING;
2253 rc = listening_get_next(seq, NULL);
2254 while (offset-- && rc)
2255 rc = listening_get_next(seq, rc);
2256 if (rc)
2257 break;
2258 st->bucket = 0;
2259 /* Fallthrough */
2260 case TCP_SEQ_STATE_ESTABLISHED:
2261 case TCP_SEQ_STATE_TIME_WAIT:
2262 st->state = TCP_SEQ_STATE_ESTABLISHED;
2263 if (st->bucket > tcp_hashinfo.ehash_mask)
2264 break;
2265 rc = established_get_first(seq);
2266 while (offset-- && rc)
2267 rc = established_get_next(seq, rc);
2268 }
2269
2270 st->num = orig_num;
2271
2272 return rc;
2273 }
2274
2275 static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2276 {
2277 struct tcp_iter_state *st = seq->private;
2278 void *rc;
2279
2280 if (*pos && *pos == st->last_pos) {
2281 rc = tcp_seek_last_pos(seq);
2282 if (rc)
2283 goto out;
2284 }
2285
2286 st->state = TCP_SEQ_STATE_LISTENING;
2287 st->num = 0;
2288 st->bucket = 0;
2289 st->offset = 0;
2290 rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2291
2292 out:
2293 st->last_pos = *pos;
2294 return rc;
2295 }
2296
2297 static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2298 {
2299 struct tcp_iter_state *st = seq->private;
2300 void *rc = NULL;
2301
2302 if (v == SEQ_START_TOKEN) {
2303 rc = tcp_get_idx(seq, 0);
2304 goto out;
2305 }
2306
2307 switch (st->state) {
2308 case TCP_SEQ_STATE_OPENREQ:
2309 case TCP_SEQ_STATE_LISTENING:
2310 rc = listening_get_next(seq, v);
2311 if (!rc) {
2312 st->state = TCP_SEQ_STATE_ESTABLISHED;
2313 st->bucket = 0;
2314 st->offset = 0;
2315 rc = established_get_first(seq);
2316 }
2317 break;
2318 case TCP_SEQ_STATE_ESTABLISHED:
2319 case TCP_SEQ_STATE_TIME_WAIT:
2320 rc = established_get_next(seq, v);
2321 break;
2322 }
2323 out:
2324 ++*pos;
2325 st->last_pos = *pos;
2326 return rc;
2327 }
2328
2329 static void tcp_seq_stop(struct seq_file *seq, void *v)
2330 {
2331 struct tcp_iter_state *st = seq->private;
2332
2333 switch (st->state) {
2334 case TCP_SEQ_STATE_OPENREQ:
2335 if (v) {
2336 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2337 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2338 }
2339 case TCP_SEQ_STATE_LISTENING:
2340 if (v != SEQ_START_TOKEN)
2341 spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
2342 break;
2343 case TCP_SEQ_STATE_TIME_WAIT:
2344 case TCP_SEQ_STATE_ESTABLISHED:
2345 if (v)
2346 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2347 break;
2348 }
2349 }
2350
2351 int tcp_seq_open(struct inode *inode, struct file *file)
2352 {
2353 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
2354 struct tcp_iter_state *s;
2355 int err;
2356
2357 err = seq_open_net(inode, file, &afinfo->seq_ops,
2358 sizeof(struct tcp_iter_state));
2359 if (err < 0)
2360 return err;
2361
2362 s = ((struct seq_file *)file->private_data)->private;
2363 s->family = afinfo->family;
2364 s->last_pos = 0;
2365 return 0;
2366 }
2367 EXPORT_SYMBOL(tcp_seq_open);
2368
2369 int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
2370 {
2371 int rc = 0;
2372 struct proc_dir_entry *p;
2373
2374 afinfo->seq_ops.start = tcp_seq_start;
2375 afinfo->seq_ops.next = tcp_seq_next;
2376 afinfo->seq_ops.stop = tcp_seq_stop;
2377
2378 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2379 afinfo->seq_fops, afinfo);
2380 if (!p)
2381 rc = -ENOMEM;
2382 return rc;
2383 }
2384 EXPORT_SYMBOL(tcp_proc_register);
2385
2386 void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
2387 {
2388 proc_net_remove(net, afinfo->name);
2389 }
2390 EXPORT_SYMBOL(tcp_proc_unregister);
2391
2392 static void get_openreq4(const struct sock *sk, const struct request_sock *req,
2393 struct seq_file *f, int i, int uid, int *len)
2394 {
2395 const struct inet_request_sock *ireq = inet_rsk(req);
2396 int ttd = req->expires - jiffies;
2397
2398 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2399 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
2400 i,
2401 ireq->loc_addr,
2402 ntohs(inet_sk(sk)->inet_sport),
2403 ireq->rmt_addr,
2404 ntohs(ireq->rmt_port),
2405 TCP_SYN_RECV,
2406 0, 0, /* could print option size, but that is af dependent. */
2407 1, /* timers active (only the expire timer) */
2408 jiffies_to_clock_t(ttd),
2409 req->retrans,
2410 uid,
2411 0, /* non standard timer */
2412 0, /* open_requests have no inode */
2413 atomic_read(&sk->sk_refcnt),
2414 req,
2415 len);
2416 }
2417
2418 static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
2419 {
2420 int timer_active;
2421 unsigned long timer_expires;
2422 const struct tcp_sock *tp = tcp_sk(sk);
2423 const struct inet_connection_sock *icsk = inet_csk(sk);
2424 const struct inet_sock *inet = inet_sk(sk);
2425 __be32 dest = inet->inet_daddr;
2426 __be32 src = inet->inet_rcv_saddr;
2427 __u16 destp = ntohs(inet->inet_dport);
2428 __u16 srcp = ntohs(inet->inet_sport);
2429 int rx_queue;
2430
2431 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2432 timer_active = 1;
2433 timer_expires = icsk->icsk_timeout;
2434 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2435 timer_active = 4;
2436 timer_expires = icsk->icsk_timeout;
2437 } else if (timer_pending(&sk->sk_timer)) {
2438 timer_active = 2;
2439 timer_expires = sk->sk_timer.expires;
2440 } else {
2441 timer_active = 0;
2442 timer_expires = jiffies;
2443 }
2444
2445 if (sk->sk_state == TCP_LISTEN)
2446 rx_queue = sk->sk_ack_backlog;
2447 else
2448 /*
2449 * because we dont lock socket, we might find a transient negative value
2450 */
2451 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
2452
2453 seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2454 "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n",
2455 i, src, srcp, dest, destp, sk->sk_state,
2456 tp->write_seq - tp->snd_una,
2457 rx_queue,
2458 timer_active,
2459 jiffies_to_clock_t(timer_expires - jiffies),
2460 icsk->icsk_retransmits,
2461 sock_i_uid(sk),
2462 icsk->icsk_probes_out,
2463 sock_i_ino(sk),
2464 atomic_read(&sk->sk_refcnt), sk,
2465 jiffies_to_clock_t(icsk->icsk_rto),
2466 jiffies_to_clock_t(icsk->icsk_ack.ato),
2467 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
2468 tp->snd_cwnd,
2469 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
2470 len);
2471 }
2472
2473 static void get_timewait4_sock(const struct inet_timewait_sock *tw,
2474 struct seq_file *f, int i, int *len)
2475 {
2476 __be32 dest, src;
2477 __u16 destp, srcp;
2478 int ttd = tw->tw_ttd - jiffies;
2479
2480 if (ttd < 0)
2481 ttd = 0;
2482
2483 dest = tw->tw_daddr;
2484 src = tw->tw_rcv_saddr;
2485 destp = ntohs(tw->tw_dport);
2486 srcp = ntohs(tw->tw_sport);
2487
2488 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2489 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
2490 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2491 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2492 atomic_read(&tw->tw_refcnt), tw, len);
2493 }
2494
2495 #define TMPSZ 150
2496
2497 static int tcp4_seq_show(struct seq_file *seq, void *v)
2498 {
2499 struct tcp_iter_state *st;
2500 int len;
2501
2502 if (v == SEQ_START_TOKEN) {
2503 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2504 " sl local_address rem_address st tx_queue "
2505 "rx_queue tr tm->when retrnsmt uid timeout "
2506 "inode");
2507 goto out;
2508 }
2509 st = seq->private;
2510
2511 switch (st->state) {
2512 case TCP_SEQ_STATE_LISTENING:
2513 case TCP_SEQ_STATE_ESTABLISHED:
2514 get_tcp4_sock(v, seq, st->num, &len);
2515 break;
2516 case TCP_SEQ_STATE_OPENREQ:
2517 get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
2518 break;
2519 case TCP_SEQ_STATE_TIME_WAIT:
2520 get_timewait4_sock(v, seq, st->num, &len);
2521 break;
2522 }
2523 seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
2524 out:
2525 return 0;
2526 }
2527
2528 static const struct file_operations tcp_afinfo_seq_fops = {
2529 .owner = THIS_MODULE,
2530 .open = tcp_seq_open,
2531 .read = seq_read,
2532 .llseek = seq_lseek,
2533 .release = seq_release_net
2534 };
2535
2536 static struct tcp_seq_afinfo tcp4_seq_afinfo = {
2537 .name = "tcp",
2538 .family = AF_INET,
2539 .seq_fops = &tcp_afinfo_seq_fops,
2540 .seq_ops = {
2541 .show = tcp4_seq_show,
2542 },
2543 };
2544
2545 static int __net_init tcp4_proc_init_net(struct net *net)
2546 {
2547 return tcp_proc_register(net, &tcp4_seq_afinfo);
2548 }
2549
2550 static void __net_exit tcp4_proc_exit_net(struct net *net)
2551 {
2552 tcp_proc_unregister(net, &tcp4_seq_afinfo);
2553 }
2554
2555 static struct pernet_operations tcp4_net_ops = {
2556 .init = tcp4_proc_init_net,
2557 .exit = tcp4_proc_exit_net,
2558 };
2559
2560 int __init tcp4_proc_init(void)
2561 {
2562 return register_pernet_subsys(&tcp4_net_ops);
2563 }
2564
2565 void tcp4_proc_exit(void)
2566 {
2567 unregister_pernet_subsys(&tcp4_net_ops);
2568 }
2569 #endif /* CONFIG_PROC_FS */
2570
2571 struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2572 {
2573 const struct iphdr *iph = skb_gro_network_header(skb);
2574
2575 switch (skb->ip_summed) {
2576 case CHECKSUM_COMPLETE:
2577 if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
2578 skb->csum)) {
2579 skb->ip_summed = CHECKSUM_UNNECESSARY;
2580 break;
2581 }
2582
2583 /* fall through */
2584 case CHECKSUM_NONE:
2585 NAPI_GRO_CB(skb)->flush = 1;
2586 return NULL;
2587 }
2588
2589 return tcp_gro_receive(head, skb);
2590 }
2591
2592 int tcp4_gro_complete(struct sk_buff *skb)
2593 {
2594 const struct iphdr *iph = ip_hdr(skb);
2595 struct tcphdr *th = tcp_hdr(skb);
2596
2597 th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
2598 iph->saddr, iph->daddr, 0);
2599 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
2600
2601 return tcp_gro_complete(skb);
2602 }
2603
2604 struct proto tcp_prot = {
2605 .name = "TCP",
2606 .owner = THIS_MODULE,
2607 .close = tcp_close,
2608 .connect = tcp_v4_connect,
2609 .disconnect = tcp_disconnect,
2610 .accept = inet_csk_accept,
2611 .ioctl = tcp_ioctl,
2612 .init = tcp_v4_init_sock,
2613 .destroy = tcp_v4_destroy_sock,
2614 .shutdown = tcp_shutdown,
2615 .setsockopt = tcp_setsockopt,
2616 .getsockopt = tcp_getsockopt,
2617 .recvmsg = tcp_recvmsg,
2618 .sendmsg = tcp_sendmsg,
2619 .sendpage = tcp_sendpage,
2620 .backlog_rcv = tcp_v4_do_rcv,
2621 .release_cb = tcp_release_cb,
2622 .mtu_reduced = tcp_v4_mtu_reduced,
2623 .hash = inet_hash,
2624 .unhash = inet_unhash,
2625 .get_port = inet_csk_get_port,
2626 .enter_memory_pressure = tcp_enter_memory_pressure,
2627 .sockets_allocated = &tcp_sockets_allocated,
2628 .orphan_count = &tcp_orphan_count,
2629 .memory_allocated = &tcp_memory_allocated,
2630 .memory_pressure = &tcp_memory_pressure,
2631 .sysctl_wmem = sysctl_tcp_wmem,
2632 .sysctl_rmem = sysctl_tcp_rmem,
2633 .max_header = MAX_TCP_HEADER,
2634 .obj_size = sizeof(struct tcp_sock),
2635 .slab_flags = SLAB_DESTROY_BY_RCU,
2636 .twsk_prot = &tcp_timewait_sock_ops,
2637 .rsk_prot = &tcp_request_sock_ops,
2638 .h.hashinfo = &tcp_hashinfo,
2639 .no_autobind = true,
2640 #ifdef CONFIG_COMPAT
2641 .compat_setsockopt = compat_tcp_setsockopt,
2642 .compat_getsockopt = compat_tcp_getsockopt,
2643 #endif
2644 #ifdef CONFIG_MEMCG_KMEM
2645 .init_cgroup = tcp_init_cgroup,
2646 .destroy_cgroup = tcp_destroy_cgroup,
2647 .proto_cgroup = tcp_proto_cgroup,
2648 #endif
2649 };
2650 EXPORT_SYMBOL(tcp_prot);
2651
2652 static int __net_init tcp_sk_init(struct net *net)
2653 {
2654 return 0;
2655 }
2656
2657 static void __net_exit tcp_sk_exit(struct net *net)
2658 {
2659 }
2660
2661 static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
2662 {
2663 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
2664 }
2665
2666 static struct pernet_operations __net_initdata tcp_sk_ops = {
2667 .init = tcp_sk_init,
2668 .exit = tcp_sk_exit,
2669 .exit_batch = tcp_sk_exit_batch,
2670 };
2671
2672 void __init tcp_v4_init(void)
2673 {
2674 inet_hashinfo_init(&tcp_hashinfo);
2675 if (register_pernet_subsys(&tcp_sk_ops))
2676 panic("Failed to create the TCP control socket.\n");
2677 }
Linux 2.6 libata-dev (mirror)