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54#include <linux/bottom_half.h>
55#include <linux/types.h>
56#include <linux/fcntl.h>
57#include <linux/module.h>
58#include <linux/random.h>
59#include <linux/cache.h>
60#include <linux/jhash.h>
61#include <linux/init.h>
62#include <linux/times.h>
63#include <linux/slab.h>
64
65#include <net/net_namespace.h>
66#include <net/icmp.h>
67#include <net/inet_hashtables.h>
68#include <net/tcp.h>
69#include <net/transp_v6.h>
70#include <net/ipv6.h>
71#include <net/inet_common.h>
72#include <net/timewait_sock.h>
73#include <net/xfrm.h>
74#include <net/netdma.h>
75
76#include <linux/inet.h>
77#include <linux/ipv6.h>
78#include <linux/stddef.h>
79#include <linux/proc_fs.h>
80#include <linux/seq_file.h>
81
82#include <linux/crypto.h>
83#include <linux/scatterlist.h>
84
85int sysctl_tcp_tw_reuse __read_mostly;
86int sysctl_tcp_low_latency __read_mostly;
87EXPORT_SYMBOL(sysctl_tcp_low_latency);
88
89
90#ifdef CONFIG_TCP_MD5SIG
91static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
92 __be32 addr);
93static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
94 __be32 daddr, __be32 saddr, struct tcphdr *th);
95#else
96static inline
97struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
98{
99 return NULL;
100}
101#endif
102
103struct inet_hashinfo tcp_hashinfo;
104EXPORT_SYMBOL(tcp_hashinfo);
105
106static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
107{
108 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
109 ip_hdr(skb)->saddr,
110 tcp_hdr(skb)->dest,
111 tcp_hdr(skb)->source);
112}
113
114int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
115{
116 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
117 struct tcp_sock *tp = tcp_sk(sk);
118
119
120
121
122
123
124
125
126
127
128
129
130 if (tcptw->tw_ts_recent_stamp &&
131 (twp == NULL || (sysctl_tcp_tw_reuse &&
132 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
133 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
134 if (tp->write_seq == 0)
135 tp->write_seq = 1;
136 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
137 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
138 sock_hold(sktw);
139 return 1;
140 }
141
142 return 0;
143}
144EXPORT_SYMBOL_GPL(tcp_twsk_unique);
145
146
147int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
148{
149 struct inet_sock *inet = inet_sk(sk);
150 struct tcp_sock *tp = tcp_sk(sk);
151 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
152 struct rtable *rt;
153 __be32 daddr, nexthop;
154 int tmp;
155 int err;
156
157 if (addr_len < sizeof(struct sockaddr_in))
158 return -EINVAL;
159
160 if (usin->sin_family != AF_INET)
161 return -EAFNOSUPPORT;
162
163 nexthop = daddr = usin->sin_addr.s_addr;
164 if (inet->opt && inet->opt->srr) {
165 if (!daddr)
166 return -EINVAL;
167 nexthop = inet->opt->faddr;
168 }
169
170 tmp = ip_route_connect(&rt, nexthop, inet->inet_saddr,
171 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
172 IPPROTO_TCP,
173 inet->inet_sport, usin->sin_port, sk, 1);
174 if (tmp < 0) {
175 if (tmp == -ENETUNREACH)
176 IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
177 return tmp;
178 }
179
180 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
181 ip_rt_put(rt);
182 return -ENETUNREACH;
183 }
184
185 if (!inet->opt || !inet->opt->srr)
186 daddr = rt->rt_dst;
187
188 if (!inet->inet_saddr)
189 inet->inet_saddr = rt->rt_src;
190 inet->inet_rcv_saddr = inet->inet_saddr;
191
192 if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) {
193
194 tp->rx_opt.ts_recent = 0;
195 tp->rx_opt.ts_recent_stamp = 0;
196 tp->write_seq = 0;
197 }
198
199 if (tcp_death_row.sysctl_tw_recycle &&
200 !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
201 struct inet_peer *peer = rt_get_peer(rt);
202
203
204
205
206
207
208 if (peer) {
209 inet_peer_refcheck(peer);
210 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
211 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
212 tp->rx_opt.ts_recent = peer->tcp_ts;
213 }
214 }
215 }
216
217 inet->inet_dport = usin->sin_port;
218 inet->inet_daddr = daddr;
219
220 inet_csk(sk)->icsk_ext_hdr_len = 0;
221 if (inet->opt)
222 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
223
224 tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
225
226
227
228
229
230
231 tcp_set_state(sk, TCP_SYN_SENT);
232 err = inet_hash_connect(&tcp_death_row, sk);
233 if (err)
234 goto failure;
235
236 err = ip_route_newports(&rt, IPPROTO_TCP,
237 inet->inet_sport, inet->inet_dport, sk);
238 if (err)
239 goto failure;
240
241
242 sk->sk_gso_type = SKB_GSO_TCPV4;
243 sk_setup_caps(sk, &rt->dst);
244
245 if (!tp->write_seq)
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 err = tcp_connect(sk);
254 rt = NULL;
255 if (err)
256 goto failure;
257
258 return 0;
259
260failure:
261
262
263
264
265 tcp_set_state(sk, TCP_CLOSE);
266 ip_rt_put(rt);
267 sk->sk_route_caps = 0;
268 inet->inet_dport = 0;
269 return err;
270}
271EXPORT_SYMBOL(tcp_v4_connect);
272
273
274
275
276static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
277{
278 struct dst_entry *dst;
279 struct inet_sock *inet = inet_sk(sk);
280
281
282
283
284
285 if (sk->sk_state == TCP_LISTEN)
286 return;
287
288
289
290
291
292
293
294 if ((dst = __sk_dst_check(sk, 0)) == NULL)
295 return;
296
297 dst->ops->update_pmtu(dst, mtu);
298
299
300
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
312
313
314
315
316 tcp_simple_retransmit(sk);
317 }
318}
319
320
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331
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334
335
336void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
337{
338 struct iphdr *iph = (struct iphdr *)icmp_skb->data;
339 struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));
340 struct inet_connection_sock *icsk;
341 struct tcp_sock *tp;
342 struct inet_sock *inet;
343 const int type = icmp_hdr(icmp_skb)->type;
344 const int code = icmp_hdr(icmp_skb)->code;
345 struct sock *sk;
346 struct sk_buff *skb;
347 __u32 seq;
348 __u32 remaining;
349 int err;
350 struct net *net = dev_net(icmp_skb->dev);
351
352 if (icmp_skb->len < (iph->ihl << 2) + 8) {
353 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
354 return;
355 }
356
357 sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
358 iph->saddr, th->source, inet_iif(icmp_skb));
359 if (!sk) {
360 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
361 return;
362 }
363 if (sk->sk_state == TCP_TIME_WAIT) {
364 inet_twsk_put(inet_twsk(sk));
365 return;
366 }
367
368 bh_lock_sock(sk);
369
370
371
372 if (sock_owned_by_user(sk))
373 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
374
375 if (sk->sk_state == TCP_CLOSE)
376 goto out;
377
378 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
379 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
380 goto out;
381 }
382
383 icsk = inet_csk(sk);
384 tp = tcp_sk(sk);
385 seq = ntohl(th->seq);
386 if (sk->sk_state != TCP_LISTEN &&
387 !between(seq, tp->snd_una, tp->snd_nxt)) {
388 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
389 goto out;
390 }
391
392 switch (type) {
393 case ICMP_SOURCE_QUENCH:
394
395 goto out;
396 case ICMP_PARAMETERPROB:
397 err = EPROTO;
398 break;
399 case ICMP_DEST_UNREACH:
400 if (code > NR_ICMP_UNREACH)
401 goto out;
402
403 if (code == ICMP_FRAG_NEEDED) {
404 if (!sock_owned_by_user(sk))
405 do_pmtu_discovery(sk, iph, info);
406 goto out;
407 }
408
409 err = icmp_err_convert[code].errno;
410
411
412 if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
413 break;
414 if (seq != tp->snd_una || !icsk->icsk_retransmits ||
415 !icsk->icsk_backoff)
416 break;
417
418 if (sock_owned_by_user(sk))
419 break;
420
421 icsk->icsk_backoff--;
422 inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) <<
423 icsk->icsk_backoff;
424 tcp_bound_rto(sk);
425
426 skb = tcp_write_queue_head(sk);
427 BUG_ON(!skb);
428
429 remaining = icsk->icsk_rto - min(icsk->icsk_rto,
430 tcp_time_stamp - TCP_SKB_CB(skb)->when);
431
432 if (remaining) {
433 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
434 remaining, TCP_RTO_MAX);
435 } else {
436
437
438 tcp_retransmit_timer(sk);
439 }
440
441 break;
442 case ICMP_TIME_EXCEEDED:
443 err = EHOSTUNREACH;
444 break;
445 default:
446 goto out;
447 }
448
449 switch (sk->sk_state) {
450 struct request_sock *req, **prev;
451 case TCP_LISTEN:
452 if (sock_owned_by_user(sk))
453 goto out;
454
455 req = inet_csk_search_req(sk, &prev, th->dest,
456 iph->daddr, iph->saddr);
457 if (!req)
458 goto out;
459
460
461
462
463 WARN_ON(req->sk);
464
465 if (seq != tcp_rsk(req)->snt_isn) {
466 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
467 goto out;
468 }
469
470
471
472
473
474
475
476 inet_csk_reqsk_queue_drop(sk, req, prev);
477 goto out;
478
479 case TCP_SYN_SENT:
480 case TCP_SYN_RECV:
481
482
483 if (!sock_owned_by_user(sk)) {
484 sk->sk_err = err;
485
486 sk->sk_error_report(sk);
487
488 tcp_done(sk);
489 } else {
490 sk->sk_err_soft = err;
491 }
492 goto out;
493 }
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511 inet = inet_sk(sk);
512 if (!sock_owned_by_user(sk) && inet->recverr) {
513 sk->sk_err = err;
514 sk->sk_error_report(sk);
515 } else {
516 sk->sk_err_soft = err;
517 }
518
519out:
520 bh_unlock_sock(sk);
521 sock_put(sk);
522}
523
524static void __tcp_v4_send_check(struct sk_buff *skb,
525 __be32 saddr, __be32 daddr)
526{
527 struct tcphdr *th = tcp_hdr(skb);
528
529 if (skb->ip_summed == CHECKSUM_PARTIAL) {
530 th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0);
531 skb->csum_start = skb_transport_header(skb) - skb->head;
532 skb->csum_offset = offsetof(struct tcphdr, check);
533 } else {
534 th->check = tcp_v4_check(skb->len, saddr, daddr,
535 csum_partial(th,
536 th->doff << 2,
537 skb->csum));
538 }
539}
540
541
542void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
543{
544 struct inet_sock *inet = inet_sk(sk);
545
546 __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
547}
548EXPORT_SYMBOL(tcp_v4_send_check);
549
550int tcp_v4_gso_send_check(struct sk_buff *skb)
551{
552 const struct iphdr *iph;
553 struct tcphdr *th;
554
555 if (!pskb_may_pull(skb, sizeof(*th)))
556 return -EINVAL;
557
558 iph = ip_hdr(skb);
559 th = tcp_hdr(skb);
560
561 th->check = 0;
562 skb->ip_summed = CHECKSUM_PARTIAL;
563 __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
564 return 0;
565}
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
581{
582 struct tcphdr *th = tcp_hdr(skb);
583 struct {
584 struct tcphdr th;
585#ifdef CONFIG_TCP_MD5SIG
586 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
587#endif
588 } rep;
589 struct ip_reply_arg arg;
590#ifdef CONFIG_TCP_MD5SIG
591 struct tcp_md5sig_key *key;
592#endif
593 struct net *net;
594
595
596 if (th->rst)
597 return;
598
599 if (skb_rtable(skb)->rt_type != RTN_LOCAL)
600 return;
601
602
603 memset(&rep, 0, sizeof(rep));
604 rep.th.dest = th->source;
605 rep.th.source = th->dest;
606 rep.th.doff = sizeof(struct tcphdr) / 4;
607 rep.th.rst = 1;
608
609 if (th->ack) {
610 rep.th.seq = th->ack_seq;
611 } else {
612 rep.th.ack = 1;
613 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
614 skb->len - (th->doff << 2));
615 }
616
617 memset(&arg, 0, sizeof(arg));
618 arg.iov[0].iov_base = (unsigned char *)&rep;
619 arg.iov[0].iov_len = sizeof(rep.th);
620
621#ifdef CONFIG_TCP_MD5SIG
622 key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
623 if (key) {
624 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
625 (TCPOPT_NOP << 16) |
626 (TCPOPT_MD5SIG << 8) |
627 TCPOLEN_MD5SIG);
628
629 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
630 rep.th.doff = arg.iov[0].iov_len / 4;
631
632 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
633 key, ip_hdr(skb)->saddr,
634 ip_hdr(skb)->daddr, &rep.th);
635 }
636#endif
637 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
638 ip_hdr(skb)->saddr,
639 arg.iov[0].iov_len, IPPROTO_TCP, 0);
640 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
641 arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
642
643 net = dev_net(skb_dst(skb)->dev);
644 ip_send_reply(net->ipv4.tcp_sock, skb,
645 &arg, arg.iov[0].iov_len);
646
647 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
648 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
649}
650
651
652
653
654
655static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
656 u32 win, u32 ts, int oif,
657 struct tcp_md5sig_key *key,
658 int reply_flags)
659{
660 struct tcphdr *th = tcp_hdr(skb);
661 struct {
662 struct tcphdr th;
663 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
664#ifdef CONFIG_TCP_MD5SIG
665 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
666#endif
667 ];
668 } rep;
669 struct ip_reply_arg arg;
670 struct net *net = dev_net(skb_dst(skb)->dev);
671
672 memset(&rep.th, 0, sizeof(struct tcphdr));
673 memset(&arg, 0, sizeof(arg));
674
675 arg.iov[0].iov_base = (unsigned char *)&rep;
676 arg.iov[0].iov_len = sizeof(rep.th);
677 if (ts) {
678 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
679 (TCPOPT_TIMESTAMP << 8) |
680 TCPOLEN_TIMESTAMP);
681 rep.opt[1] = htonl(tcp_time_stamp);
682 rep.opt[2] = htonl(ts);
683 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
684 }
685
686
687 rep.th.dest = th->source;
688 rep.th.source = th->dest;
689 rep.th.doff = arg.iov[0].iov_len / 4;
690 rep.th.seq = htonl(seq);
691 rep.th.ack_seq = htonl(ack);
692 rep.th.ack = 1;
693 rep.th.window = htons(win);
694
695#ifdef CONFIG_TCP_MD5SIG
696 if (key) {
697 int offset = (ts) ? 3 : 0;
698
699 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
700 (TCPOPT_NOP << 16) |
701 (TCPOPT_MD5SIG << 8) |
702 TCPOLEN_MD5SIG);
703 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
704 rep.th.doff = arg.iov[0].iov_len/4;
705
706 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
707 key, ip_hdr(skb)->saddr,
708 ip_hdr(skb)->daddr, &rep.th);
709 }
710#endif
711 arg.flags = reply_flags;
712 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
713 ip_hdr(skb)->saddr,
714 arg.iov[0].iov_len, IPPROTO_TCP, 0);
715 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
716 if (oif)
717 arg.bound_dev_if = oif;
718
719 ip_send_reply(net->ipv4.tcp_sock, skb,
720 &arg, arg.iov[0].iov_len);
721
722 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
723}
724
725static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
726{
727 struct inet_timewait_sock *tw = inet_twsk(sk);
728 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
729
730 tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
731 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
732 tcptw->tw_ts_recent,
733 tw->tw_bound_dev_if,
734 tcp_twsk_md5_key(tcptw),
735 tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0
736 );
737
738 inet_twsk_put(tw);
739}
740
741static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
742 struct request_sock *req)
743{
744 tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
745 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
746 req->ts_recent,
747 0,
748 tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
749 inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
750}
751
752
753
754
755
756
757static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
758 struct request_sock *req,
759 struct request_values *rvp)
760{
761 const struct inet_request_sock *ireq = inet_rsk(req);
762 int err = -1;
763 struct sk_buff * skb;
764
765
766 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
767 return -1;
768
769 skb = tcp_make_synack(sk, dst, req, rvp);
770
771 if (skb) {
772 __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);
773
774 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
775 ireq->rmt_addr,
776 ireq->opt);
777 err = net_xmit_eval(err);
778 }
779
780 dst_release(dst);
781 return err;
782}
783
784static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req,
785 struct request_values *rvp)
786{
787 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
788 return tcp_v4_send_synack(sk, NULL, req, rvp);
789}
790
791
792
793
794static void tcp_v4_reqsk_destructor(struct request_sock *req)
795{
796 kfree(inet_rsk(req)->opt);
797}
798
799static void syn_flood_warning(const struct sk_buff *skb)
800{
801 const char *msg;
802
803#ifdef CONFIG_SYN_COOKIES
804 if (sysctl_tcp_syncookies)
805 msg = "Sending cookies";
806 else
807#endif
808 msg = "Dropping request";
809
810 pr_info("TCP: Possible SYN flooding on port %d. %s.\n",
811 ntohs(tcp_hdr(skb)->dest), msg);
812}
813
814
815
816
817static struct ip_options *tcp_v4_save_options(struct sock *sk,
818 struct sk_buff *skb)
819{
820 struct ip_options *opt = &(IPCB(skb)->opt);
821 struct ip_options *dopt = NULL;
822
823 if (opt && opt->optlen) {
824 int opt_size = optlength(opt);
825 dopt = kmalloc(opt_size, GFP_ATOMIC);
826 if (dopt) {
827 if (ip_options_echo(dopt, skb)) {
828 kfree(dopt);
829 dopt = NULL;
830 }
831 }
832 }
833 return dopt;
834}
835
836#ifdef CONFIG_TCP_MD5SIG
837
838
839
840
841
842
843
844static struct tcp_md5sig_key *
845 tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
846{
847 struct tcp_sock *tp = tcp_sk(sk);
848 int i;
849
850 if (!tp->md5sig_info || !tp->md5sig_info->entries4)
851 return NULL;
852 for (i = 0; i < tp->md5sig_info->entries4; i++) {
853 if (tp->md5sig_info->keys4[i].addr == addr)
854 return &tp->md5sig_info->keys4[i].base;
855 }
856 return NULL;
857}
858
859struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
860 struct sock *addr_sk)
861{
862 return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->inet_daddr);
863}
864EXPORT_SYMBOL(tcp_v4_md5_lookup);
865
866static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
867 struct request_sock *req)
868{
869 return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
870}
871
872
873int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
874 u8 *newkey, u8 newkeylen)
875{
876
877 struct tcp_md5sig_key *key;
878 struct tcp_sock *tp = tcp_sk(sk);
879 struct tcp4_md5sig_key *keys;
880
881 key = tcp_v4_md5_do_lookup(sk, addr);
882 if (key) {
883
884 kfree(key->key);
885 key->key = newkey;
886 key->keylen = newkeylen;
887 } else {
888 struct tcp_md5sig_info *md5sig;
889
890 if (!tp->md5sig_info) {
891 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
892 GFP_ATOMIC);
893 if (!tp->md5sig_info) {
894 kfree(newkey);
895 return -ENOMEM;
896 }
897 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
898 }
899 if (tcp_alloc_md5sig_pool(sk) == NULL) {
900 kfree(newkey);
901 return -ENOMEM;
902 }
903 md5sig = tp->md5sig_info;
904
905 if (md5sig->alloced4 == md5sig->entries4) {
906 keys = kmalloc((sizeof(*keys) *
907 (md5sig->entries4 + 1)), GFP_ATOMIC);
908 if (!keys) {
909 kfree(newkey);
910 tcp_free_md5sig_pool();
911 return -ENOMEM;
912 }
913
914 if (md5sig->entries4)
915 memcpy(keys, md5sig->keys4,
916 sizeof(*keys) * md5sig->entries4);
917
918
919 kfree(md5sig->keys4);
920 md5sig->keys4 = keys;
921 md5sig->alloced4++;
922 }
923 md5sig->entries4++;
924 md5sig->keys4[md5sig->entries4 - 1].addr = addr;
925 md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
926 md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
927 }
928 return 0;
929}
930EXPORT_SYMBOL(tcp_v4_md5_do_add);
931
932static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
933 u8 *newkey, u8 newkeylen)
934{
935 return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->inet_daddr,
936 newkey, newkeylen);
937}
938
939int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
940{
941 struct tcp_sock *tp = tcp_sk(sk);
942 int i;
943
944 for (i = 0; i < tp->md5sig_info->entries4; i++) {
945 if (tp->md5sig_info->keys4[i].addr == addr) {
946
947 kfree(tp->md5sig_info->keys4[i].base.key);
948 tp->md5sig_info->entries4--;
949
950 if (tp->md5sig_info->entries4 == 0) {
951 kfree(tp->md5sig_info->keys4);
952 tp->md5sig_info->keys4 = NULL;
953 tp->md5sig_info->alloced4 = 0;
954 } else if (tp->md5sig_info->entries4 != i) {
955
956 memmove(&tp->md5sig_info->keys4[i],
957 &tp->md5sig_info->keys4[i+1],
958 (tp->md5sig_info->entries4 - i) *
959 sizeof(struct tcp4_md5sig_key));
960 }
961 tcp_free_md5sig_pool();
962 return 0;
963 }
964 }
965 return -ENOENT;
966}
967EXPORT_SYMBOL(tcp_v4_md5_do_del);
968
969static void tcp_v4_clear_md5_list(struct sock *sk)
970{
971 struct tcp_sock *tp = tcp_sk(sk);
972
973
974
975
976
977 if (tp->md5sig_info->entries4) {
978 int i;
979 for (i = 0; i < tp->md5sig_info->entries4; i++)
980 kfree(tp->md5sig_info->keys4[i].base.key);
981 tp->md5sig_info->entries4 = 0;
982 tcp_free_md5sig_pool();
983 }
984 if (tp->md5sig_info->keys4) {
985 kfree(tp->md5sig_info->keys4);
986 tp->md5sig_info->keys4 = NULL;
987 tp->md5sig_info->alloced4 = 0;
988 }
989}
990
991static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
992 int optlen)
993{
994 struct tcp_md5sig cmd;
995 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
996 u8 *newkey;
997
998 if (optlen < sizeof(cmd))
999 return -EINVAL;
1000
1001 if (copy_from_user(&cmd, optval, sizeof(cmd)))
1002 return -EFAULT;
1003
1004 if (sin->sin_family != AF_INET)
1005 return -EINVAL;
1006
1007 if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
1008 if (!tcp_sk(sk)->md5sig_info)
1009 return -ENOENT;
1010 return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
1011 }
1012
1013 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
1014 return -EINVAL;
1015
1016 if (!tcp_sk(sk)->md5sig_info) {
1017 struct tcp_sock *tp = tcp_sk(sk);
1018 struct tcp_md5sig_info *p;
1019
1020 p = kzalloc(sizeof(*p), sk->sk_allocation);
1021 if (!p)
1022 return -EINVAL;
1023
1024 tp->md5sig_info = p;
1025 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
1026 }
1027
1028 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation);
1029 if (!newkey)
1030 return -ENOMEM;
1031 return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
1032 newkey, cmd.tcpm_keylen);
1033}
1034
1035static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
1036 __be32 daddr, __be32 saddr, int nbytes)
1037{
1038 struct tcp4_pseudohdr *bp;
1039 struct scatterlist sg;
1040
1041 bp = &hp->md5_blk.ip4;
1042
1043
1044
1045
1046
1047
1048 bp->saddr = saddr;
1049 bp->daddr = daddr;
1050 bp->pad = 0;
1051 bp->protocol = IPPROTO_TCP;
1052 bp->len = cpu_to_be16(nbytes);
1053
1054 sg_init_one(&sg, bp, sizeof(*bp));
1055 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
1056}
1057
1058static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
1059 __be32 daddr, __be32 saddr, struct tcphdr *th)
1060{
1061 struct tcp_md5sig_pool *hp;
1062 struct hash_desc *desc;
1063
1064 hp = tcp_get_md5sig_pool();
1065 if (!hp)
1066 goto clear_hash_noput;
1067 desc = &hp->md5_desc;
1068
1069 if (crypto_hash_init(desc))
1070 goto clear_hash;
1071 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
1072 goto clear_hash;
1073 if (tcp_md5_hash_header(hp, th))
1074 goto clear_hash;
1075 if (tcp_md5_hash_key(hp, key))
1076 goto clear_hash;
1077 if (crypto_hash_final(desc, md5_hash))
1078 goto clear_hash;
1079
1080 tcp_put_md5sig_pool();
1081 return 0;
1082
1083clear_hash:
1084 tcp_put_md5sig_pool();
1085clear_hash_noput:
1086 memset(md5_hash, 0, 16);
1087 return 1;
1088}
1089
1090int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
1091 struct sock *sk, struct request_sock *req,
1092 struct sk_buff *skb)
1093{
1094 struct tcp_md5sig_pool *hp;
1095 struct hash_desc *desc;
1096 struct tcphdr *th = tcp_hdr(skb);
1097 __be32 saddr, daddr;
1098
1099 if (sk) {
1100 saddr = inet_sk(sk)->inet_saddr;
1101 daddr = inet_sk(sk)->inet_daddr;
1102 } else if (req) {
1103 saddr = inet_rsk(req)->loc_addr;
1104 daddr = inet_rsk(req)->rmt_addr;
1105 } else {
1106 const struct iphdr *iph = ip_hdr(skb);
1107 saddr = iph->saddr;
1108 daddr = iph->daddr;
1109 }
1110
1111 hp = tcp_get_md5sig_pool();
1112 if (!hp)
1113 goto clear_hash_noput;
1114 desc = &hp->md5_desc;
1115
1116 if (crypto_hash_init(desc))
1117 goto clear_hash;
1118
1119 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
1120 goto clear_hash;
1121 if (tcp_md5_hash_header(hp, th))
1122 goto clear_hash;
1123 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
1124 goto clear_hash;
1125 if (tcp_md5_hash_key(hp, key))
1126 goto clear_hash;
1127 if (crypto_hash_final(desc, md5_hash))
1128 goto clear_hash;
1129
1130 tcp_put_md5sig_pool();
1131 return 0;
1132
1133clear_hash:
1134 tcp_put_md5sig_pool();
1135clear_hash_noput:
1136 memset(md5_hash, 0, 16);
1137 return 1;
1138}
1139EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
1140
1141static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
1142{
1143
1144
1145
1146
1147
1148
1149
1150
1151 __u8 *hash_location = NULL;
1152 struct tcp_md5sig_key *hash_expected;
1153 const struct iphdr *iph = ip_hdr(skb);
1154 struct tcphdr *th = tcp_hdr(skb);
1155 int genhash;
1156 unsigned char newhash[16];
1157
1158 hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
1159 hash_location = tcp_parse_md5sig_option(th);
1160
1161
1162 if (!hash_expected && !hash_location)
1163 return 0;
1164
1165 if (hash_expected && !hash_location) {
1166 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
1167 return 1;
1168 }
1169
1170 if (!hash_expected && hash_location) {
1171 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
1172 return 1;
1173 }
1174
1175
1176
1177
1178 genhash = tcp_v4_md5_hash_skb(newhash,
1179 hash_expected,
1180 NULL, NULL, skb);
1181
1182 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1183 if (net_ratelimit()) {
1184 printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1185 &iph->saddr, ntohs(th->source),
1186 &iph->daddr, ntohs(th->dest),
1187 genhash ? " tcp_v4_calc_md5_hash failed" : "");
1188 }
1189 return 1;
1190 }
1191 return 0;
1192}
1193
1194#endif
1195
1196struct request_sock_ops tcp_request_sock_ops __read_mostly = {
1197 .family = PF_INET,
1198 .obj_size = sizeof(struct tcp_request_sock),
1199 .rtx_syn_ack = tcp_v4_rtx_synack,
1200 .send_ack = tcp_v4_reqsk_send_ack,
1201 .destructor = tcp_v4_reqsk_destructor,
1202 .send_reset = tcp_v4_send_reset,
1203 .syn_ack_timeout = tcp_syn_ack_timeout,
1204};
1205
1206#ifdef CONFIG_TCP_MD5SIG
1207static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
1208 .md5_lookup = tcp_v4_reqsk_md5_lookup,
1209 .calc_md5_hash = tcp_v4_md5_hash_skb,
1210};
1211#endif
1212
1213int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1214{
1215 struct tcp_extend_values tmp_ext;
1216 struct tcp_options_received tmp_opt;
1217 u8 *hash_location;
1218 struct request_sock *req;
1219 struct inet_request_sock *ireq;
1220 struct tcp_sock *tp = tcp_sk(sk);
1221 struct dst_entry *dst = NULL;
1222 __be32 saddr = ip_hdr(skb)->saddr;
1223 __be32 daddr = ip_hdr(skb)->daddr;
1224 __u32 isn = TCP_SKB_CB(skb)->when;
1225#ifdef CONFIG_SYN_COOKIES
1226 int want_cookie = 0;
1227#else
1228#define want_cookie 0
1229#endif
1230
1231
1232 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
1233 goto drop;
1234
1235
1236
1237
1238
1239 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1240 if (net_ratelimit())
1241 syn_flood_warning(skb);
1242#ifdef CONFIG_SYN_COOKIES
1243 if (sysctl_tcp_syncookies) {
1244 want_cookie = 1;
1245 } else
1246#endif
1247 goto drop;
1248 }
1249
1250
1251
1252
1253
1254
1255 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1256 goto drop;
1257
1258 req = inet_reqsk_alloc(&tcp_request_sock_ops);
1259 if (!req)
1260 goto drop;
1261
1262#ifdef CONFIG_TCP_MD5SIG
1263 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1264#endif
1265
1266 tcp_clear_options(&tmp_opt);
1267 tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
1268 tmp_opt.user_mss = tp->rx_opt.user_mss;
1269 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1270
1271 if (tmp_opt.cookie_plus > 0 &&
1272 tmp_opt.saw_tstamp &&
1273 !tp->rx_opt.cookie_out_never &&
1274 (sysctl_tcp_cookie_size > 0 ||
1275 (tp->cookie_values != NULL &&
1276 tp->cookie_values->cookie_desired > 0))) {
1277 u8 *c;
1278 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1279 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1280
1281 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1282 goto drop_and_release;
1283
1284
1285 *mess++ ^= (__force u32)daddr;
1286 *mess++ ^= (__force u32)saddr;
1287
1288
1289 c = (u8 *)mess;
1290 while (l-- > 0)
1291 *c++ ^= *hash_location++;
1292
1293#ifdef CONFIG_SYN_COOKIES
1294 want_cookie = 0;
1295#endif
1296 tmp_ext.cookie_out_never = 0;
1297 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1298 } else if (!tp->rx_opt.cookie_in_always) {
1299
1300 tmp_ext.cookie_out_never = 1;
1301 tmp_ext.cookie_plus = 0;
1302 } else {
1303 goto drop_and_release;
1304 }
1305 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1306
1307 if (want_cookie && !tmp_opt.saw_tstamp)
1308 tcp_clear_options(&tmp_opt);
1309
1310 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1311 tcp_openreq_init(req, &tmp_opt, skb);
1312
1313 ireq = inet_rsk(req);
1314 ireq->loc_addr = daddr;
1315 ireq->rmt_addr = saddr;
1316 ireq->no_srccheck = inet_sk(sk)->transparent;
1317 ireq->opt = tcp_v4_save_options(sk, skb);
1318
1319 if (security_inet_conn_request(sk, skb, req))
1320 goto drop_and_free;
1321
1322 if (!want_cookie || tmp_opt.tstamp_ok)
1323 TCP_ECN_create_request(req, tcp_hdr(skb));
1324
1325 if (want_cookie) {
1326 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1327 req->cookie_ts = tmp_opt.tstamp_ok;
1328 } else if (!isn) {
1329 struct inet_peer *peer = NULL;
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340 if (tmp_opt.saw_tstamp &&
1341 tcp_death_row.sysctl_tw_recycle &&
1342 (dst = inet_csk_route_req(sk, req)) != NULL &&
1343 (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
1344 peer->daddr.a4 == saddr) {
1345 inet_peer_refcheck(peer);
1346 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1347 (s32)(peer->tcp_ts - req->ts_recent) >
1348 TCP_PAWS_WINDOW) {
1349 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1350 goto drop_and_release;
1351 }
1352 }
1353
1354 else if (!sysctl_tcp_syncookies &&
1355 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1356 (sysctl_max_syn_backlog >> 2)) &&
1357 (!peer || !peer->tcp_ts_stamp) &&
1358 (!dst || !dst_metric(dst, RTAX_RTT))) {
1359
1360
1361
1362
1363
1364
1365
1366 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n",
1367 &saddr, ntohs(tcp_hdr(skb)->source));
1368 goto drop_and_release;
1369 }
1370
1371 isn = tcp_v4_init_sequence(skb);
1372 }
1373 tcp_rsk(req)->snt_isn = isn;
1374
1375 if (tcp_v4_send_synack(sk, dst, req,
1376 (struct request_values *)&tmp_ext) ||
1377 want_cookie)
1378 goto drop_and_free;
1379
1380 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1381 return 0;
1382
1383drop_and_release:
1384 dst_release(dst);
1385drop_and_free:
1386 reqsk_free(req);
1387drop:
1388 return 0;
1389}
1390EXPORT_SYMBOL(tcp_v4_conn_request);
1391
1392
1393
1394
1395
1396
1397struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1398 struct request_sock *req,
1399 struct dst_entry *dst)
1400{
1401 struct inet_request_sock *ireq;
1402 struct inet_sock *newinet;
1403 struct tcp_sock *newtp;
1404 struct sock *newsk;
1405#ifdef CONFIG_TCP_MD5SIG
1406 struct tcp_md5sig_key *key;
1407#endif
1408
1409 if (sk_acceptq_is_full(sk))
1410 goto exit_overflow;
1411
1412 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
1413 goto exit;
1414
1415 newsk = tcp_create_openreq_child(sk, req, skb);
1416 if (!newsk)
1417 goto exit_nonewsk;
1418
1419 newsk->sk_gso_type = SKB_GSO_TCPV4;
1420 sk_setup_caps(newsk, dst);
1421
1422 newtp = tcp_sk(newsk);
1423 newinet = inet_sk(newsk);
1424 ireq = inet_rsk(req);
1425 newinet->inet_daddr = ireq->rmt_addr;
1426 newinet->inet_rcv_saddr = ireq->loc_addr;
1427 newinet->inet_saddr = ireq->loc_addr;
1428 newinet->opt = ireq->opt;
1429 ireq->opt = NULL;
1430 newinet->mc_index = inet_iif(skb);
1431 newinet->mc_ttl = ip_hdr(skb)->ttl;
1432 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1433 if (newinet->opt)
1434 inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
1435 newinet->inet_id = newtp->write_seq ^ jiffies;
1436
1437 tcp_mtup_init(newsk);
1438 tcp_sync_mss(newsk, dst_mtu(dst));
1439 newtp->advmss = dst_metric_advmss(dst);
1440 if (tcp_sk(sk)->rx_opt.user_mss &&
1441 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1442 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1443
1444 tcp_initialize_rcv_mss(newsk);
1445
1446#ifdef CONFIG_TCP_MD5SIG
1447
1448 key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr);
1449 if (key != NULL) {
1450
1451
1452
1453
1454
1455
1456 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1457 if (newkey != NULL)
1458 tcp_v4_md5_do_add(newsk, newinet->inet_daddr,
1459 newkey, key->keylen);
1460 sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
1461 }
1462#endif
1463
1464 if (__inet_inherit_port(sk, newsk) < 0) {
1465 sock_put(newsk);
1466 goto exit;
1467 }
1468 __inet_hash_nolisten(newsk, NULL);
1469
1470 return newsk;
1471
1472exit_overflow:
1473 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1474exit_nonewsk:
1475 dst_release(dst);
1476exit:
1477 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1478 return NULL;
1479}
1480EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
1481
1482static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1483{
1484 struct tcphdr *th = tcp_hdr(skb);
1485 const struct iphdr *iph = ip_hdr(skb);
1486 struct sock *nsk;
1487 struct request_sock **prev;
1488
1489 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1490 iph->saddr, iph->daddr);
1491 if (req)
1492 return tcp_check_req(sk, skb, req, prev);
1493
1494 nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
1495 th->source, iph->daddr, th->dest, inet_iif(skb));
1496
1497 if (nsk) {
1498 if (nsk->sk_state != TCP_TIME_WAIT) {
1499 bh_lock_sock(nsk);
1500 return nsk;
1501 }
1502 inet_twsk_put(inet_twsk(nsk));
1503 return NULL;
1504 }
1505
1506#ifdef CONFIG_SYN_COOKIES
1507 if (!th->syn)
1508 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1509#endif
1510 return sk;
1511}
1512
1513static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
1514{
1515 const struct iphdr *iph = ip_hdr(skb);
1516
1517 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1518 if (!tcp_v4_check(skb->len, iph->saddr,
1519 iph->daddr, skb->csum)) {
1520 skb->ip_summed = CHECKSUM_UNNECESSARY;
1521 return 0;
1522 }
1523 }
1524
1525 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1526 skb->len, IPPROTO_TCP, 0);
1527
1528 if (skb->len <= 76) {
1529 return __skb_checksum_complete(skb);
1530 }
1531 return 0;
1532}
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1544{
1545 struct sock *rsk;
1546#ifdef CONFIG_TCP_MD5SIG
1547
1548
1549
1550
1551
1552
1553 if (tcp_v4_inbound_md5_hash(sk, skb))
1554 goto discard;
1555#endif
1556
1557 if (sk->sk_state == TCP_ESTABLISHED) {
1558 sock_rps_save_rxhash(sk, skb->rxhash);
1559 TCP_CHECK_TIMER(sk);
1560 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
1561 rsk = sk;
1562 goto reset;
1563 }
1564 TCP_CHECK_TIMER(sk);
1565 return 0;
1566 }
1567
1568 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1569 goto csum_err;
1570
1571 if (sk->sk_state == TCP_LISTEN) {
1572 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1573 if (!nsk)
1574 goto discard;
1575
1576 if (nsk != sk) {
1577 if (tcp_child_process(sk, nsk, skb)) {
1578 rsk = nsk;
1579 goto reset;
1580 }
1581 return 0;
1582 }
1583 } else
1584 sock_rps_save_rxhash(sk, skb->rxhash);
1585
1586
1587 TCP_CHECK_TIMER(sk);
1588 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
1589 rsk = sk;
1590 goto reset;
1591 }
1592 TCP_CHECK_TIMER(sk);
1593 return 0;
1594
1595reset:
1596 tcp_v4_send_reset(rsk, skb);
1597discard:
1598 kfree_skb(skb);
1599
1600
1601
1602
1603
1604 return 0;
1605
1606csum_err:
1607 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1608 goto discard;
1609}
1610EXPORT_SYMBOL(tcp_v4_do_rcv);
1611
1612
1613
1614
1615
1616int tcp_v4_rcv(struct sk_buff *skb)
1617{
1618 const struct iphdr *iph;
1619 struct tcphdr *th;
1620 struct sock *sk;
1621 int ret;
1622 struct net *net = dev_net(skb->dev);
1623
1624 if (skb->pkt_type != PACKET_HOST)
1625 goto discard_it;
1626
1627
1628 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1629
1630 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1631 goto discard_it;
1632
1633 th = tcp_hdr(skb);
1634
1635 if (th->doff < sizeof(struct tcphdr) / 4)
1636 goto bad_packet;
1637 if (!pskb_may_pull(skb, th->doff * 4))
1638 goto discard_it;
1639
1640
1641
1642
1643
1644 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
1645 goto bad_packet;
1646
1647 th = tcp_hdr(skb);
1648 iph = ip_hdr(skb);
1649 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1650 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1651 skb->len - th->doff * 4);
1652 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1653 TCP_SKB_CB(skb)->when = 0;
1654 TCP_SKB_CB(skb)->flags = iph->tos;
1655 TCP_SKB_CB(skb)->sacked = 0;
1656
1657 sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1658 if (!sk)
1659 goto no_tcp_socket;
1660
1661process:
1662 if (sk->sk_state == TCP_TIME_WAIT)
1663 goto do_time_wait;
1664
1665 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
1666 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1667 goto discard_and_relse;
1668 }
1669
1670 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1671 goto discard_and_relse;
1672 nf_reset(skb);
1673
1674 if (sk_filter(sk, skb))
1675 goto discard_and_relse;
1676
1677 skb->dev = NULL;
1678
1679 bh_lock_sock_nested(sk);
1680 ret = 0;
1681 if (!sock_owned_by_user(sk)) {
1682#ifdef CONFIG_NET_DMA
1683 struct tcp_sock *tp = tcp_sk(sk);
1684 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1685 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1686 if (tp->ucopy.dma_chan)
1687 ret = tcp_v4_do_rcv(sk, skb);
1688 else
1689#endif
1690 {
1691 if (!tcp_prequeue(sk, skb))
1692 ret = tcp_v4_do_rcv(sk, skb);
1693 }
1694 } else if (unlikely(sk_add_backlog(sk, skb))) {
1695 bh_unlock_sock(sk);
1696 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1697 goto discard_and_relse;
1698 }
1699 bh_unlock_sock(sk);
1700
1701 sock_put(sk);
1702
1703 return ret;
1704
1705no_tcp_socket:
1706 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1707 goto discard_it;
1708
1709 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1710bad_packet:
1711 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1712 } else {
1713 tcp_v4_send_reset(NULL, skb);
1714 }
1715
1716discard_it:
1717
1718 kfree_skb(skb);
1719 return 0;
1720
1721discard_and_relse:
1722 sock_put(sk);
1723 goto discard_it;
1724
1725do_time_wait:
1726 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1727 inet_twsk_put(inet_twsk(sk));
1728 goto discard_it;
1729 }
1730
1731 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1732 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1733 inet_twsk_put(inet_twsk(sk));
1734 goto discard_it;
1735 }
1736 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1737 case TCP_TW_SYN: {
1738 struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
1739 &tcp_hashinfo,
1740 iph->daddr, th->dest,
1741 inet_iif(skb));
1742 if (sk2) {
1743 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1744 inet_twsk_put(inet_twsk(sk));
1745 sk = sk2;
1746 goto process;
1747 }
1748
1749 }
1750 case TCP_TW_ACK:
1751 tcp_v4_timewait_ack(sk, skb);
1752 break;
1753 case TCP_TW_RST:
1754 goto no_tcp_socket;
1755 case TCP_TW_SUCCESS:;
1756 }
1757 goto discard_it;
1758}
1759
1760struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it)
1761{
1762 struct rtable *rt = (struct rtable *) __sk_dst_get(sk);
1763 struct inet_sock *inet = inet_sk(sk);
1764 struct inet_peer *peer;
1765
1766 if (!rt || rt->rt_dst != inet->inet_daddr) {
1767 peer = inet_getpeer_v4(inet->inet_daddr, 1);
1768 *release_it = true;
1769 } else {
1770 if (!rt->peer)
1771 rt_bind_peer(rt, 1);
1772 peer = rt->peer;
1773 *release_it = false;
1774 }
1775
1776 return peer;
1777}
1778EXPORT_SYMBOL(tcp_v4_get_peer);
1779
1780void *tcp_v4_tw_get_peer(struct sock *sk)
1781{
1782 struct inet_timewait_sock *tw = inet_twsk(sk);
1783
1784 return inet_getpeer_v4(tw->tw_daddr, 1);
1785}
1786EXPORT_SYMBOL(tcp_v4_tw_get_peer);
1787
1788static struct timewait_sock_ops tcp_timewait_sock_ops = {
1789 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1790 .twsk_unique = tcp_twsk_unique,
1791 .twsk_destructor= tcp_twsk_destructor,
1792 .twsk_getpeer = tcp_v4_tw_get_peer,
1793};
1794
1795const struct inet_connection_sock_af_ops ipv4_specific = {
1796 .queue_xmit = ip_queue_xmit,
1797 .send_check = tcp_v4_send_check,
1798 .rebuild_header = inet_sk_rebuild_header,
1799 .conn_request = tcp_v4_conn_request,
1800 .syn_recv_sock = tcp_v4_syn_recv_sock,
1801 .get_peer = tcp_v4_get_peer,
1802 .net_header_len = sizeof(struct iphdr),
1803 .setsockopt = ip_setsockopt,
1804 .getsockopt = ip_getsockopt,
1805 .addr2sockaddr = inet_csk_addr2sockaddr,
1806 .sockaddr_len = sizeof(struct sockaddr_in),
1807 .bind_conflict = inet_csk_bind_conflict,
1808#ifdef CONFIG_COMPAT
1809 .compat_setsockopt = compat_ip_setsockopt,
1810 .compat_getsockopt = compat_ip_getsockopt,
1811#endif
1812};
1813EXPORT_SYMBOL(ipv4_specific);
1814
1815#ifdef CONFIG_TCP_MD5SIG
1816static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
1817 .md5_lookup = tcp_v4_md5_lookup,
1818 .calc_md5_hash = tcp_v4_md5_hash_skb,
1819 .md5_add = tcp_v4_md5_add_func,
1820 .md5_parse = tcp_v4_parse_md5_keys,
1821};
1822#endif
1823
1824
1825
1826
1827static int tcp_v4_init_sock(struct sock *sk)
1828{
1829 struct inet_connection_sock *icsk = inet_csk(sk);
1830 struct tcp_sock *tp = tcp_sk(sk);
1831
1832 skb_queue_head_init(&tp->out_of_order_queue);
1833 tcp_init_xmit_timers(sk);
1834 tcp_prequeue_init(tp);
1835
1836 icsk->icsk_rto = TCP_TIMEOUT_INIT;
1837 tp->mdev = TCP_TIMEOUT_INIT;
1838
1839
1840
1841
1842
1843
1844 tp->snd_cwnd = 2;
1845
1846
1847
1848
1849 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1850 tp->snd_cwnd_clamp = ~0;
1851 tp->mss_cache = TCP_MSS_DEFAULT;
1852
1853 tp->reordering = sysctl_tcp_reordering;
1854 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1855
1856 sk->sk_state = TCP_CLOSE;
1857
1858 sk->sk_write_space = sk_stream_write_space;
1859 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1860
1861 icsk->icsk_af_ops = &ipv4_specific;
1862 icsk->icsk_sync_mss = tcp_sync_mss;
1863#ifdef CONFIG_TCP_MD5SIG
1864 tp->af_specific = &tcp_sock_ipv4_specific;
1865#endif
1866
1867
1868 if (sysctl_tcp_cookie_size > 0) {
1869
1870 tp->cookie_values =
1871 kzalloc(sizeof(*tp->cookie_values),
1872 sk->sk_allocation);
1873 if (tp->cookie_values != NULL)
1874 kref_init(&tp->cookie_values->kref);
1875 }
1876
1877
1878
1879
1880 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1881 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1882
1883 local_bh_disable();
1884 percpu_counter_inc(&tcp_sockets_allocated);
1885 local_bh_enable();
1886
1887 return 0;
1888}
1889
1890void tcp_v4_destroy_sock(struct sock *sk)
1891{
1892 struct tcp_sock *tp = tcp_sk(sk);
1893
1894 tcp_clear_xmit_timers(sk);
1895
1896 tcp_cleanup_congestion_control(sk);
1897
1898
1899 tcp_write_queue_purge(sk);
1900
1901
1902 __skb_queue_purge(&tp->out_of_order_queue);
1903
1904#ifdef CONFIG_TCP_MD5SIG
1905
1906 if (tp->md5sig_info) {
1907 tcp_v4_clear_md5_list(sk);
1908 kfree(tp->md5sig_info);
1909 tp->md5sig_info = NULL;
1910 }
1911#endif
1912
1913#ifdef CONFIG_NET_DMA
1914
1915 __skb_queue_purge(&sk->sk_async_wait_queue);
1916#endif
1917
1918
1919 __skb_queue_purge(&tp->ucopy.prequeue);
1920
1921
1922 if (inet_csk(sk)->icsk_bind_hash)
1923 inet_put_port(sk);
1924
1925
1926
1927
1928 if (sk->sk_sndmsg_page) {
1929 __free_page(sk->sk_sndmsg_page);
1930 sk->sk_sndmsg_page = NULL;
1931 }
1932
1933
1934 if (tp->cookie_values != NULL) {
1935 kref_put(&tp->cookie_values->kref,
1936 tcp_cookie_values_release);
1937 tp->cookie_values = NULL;
1938 }
1939
1940 percpu_counter_dec(&tcp_sockets_allocated);
1941}
1942EXPORT_SYMBOL(tcp_v4_destroy_sock);
1943
1944#ifdef CONFIG_PROC_FS
1945
1946
1947static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
1948{
1949 return hlist_nulls_empty(head) ? NULL :
1950 list_entry(head->first, struct inet_timewait_sock, tw_node);
1951}
1952
1953static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
1954{
1955 return !is_a_nulls(tw->tw_node.next) ?
1956 hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
1957}
1958
1959
1960
1961
1962
1963
1964static void *listening_get_next(struct seq_file *seq, void *cur)
1965{
1966 struct inet_connection_sock *icsk;
1967 struct hlist_nulls_node *node;
1968 struct sock *sk = cur;
1969 struct inet_listen_hashbucket *ilb;
1970 struct tcp_iter_state *st = seq->private;
1971 struct net *net = seq_file_net(seq);
1972
1973 if (!sk) {
1974 ilb = &tcp_hashinfo.listening_hash[st->bucket];
1975 spin_lock_bh(&ilb->lock);
1976 sk = sk_nulls_head(&ilb->head);
1977 st->offset = 0;
1978 goto get_sk;
1979 }
1980 ilb = &tcp_hashinfo.listening_hash[st->bucket];
1981 ++st->num;
1982 ++st->offset;
1983
1984 if (st->state == TCP_SEQ_STATE_OPENREQ) {
1985 struct request_sock *req = cur;
1986
1987 icsk = inet_csk(st->syn_wait_sk);
1988 req = req->dl_next;
1989 while (1) {
1990 while (req) {
1991 if (req->rsk_ops->family == st->family) {
1992 cur = req;
1993 goto out;
1994 }
1995 req = req->dl_next;
1996 }
1997 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
1998 break;
1999get_req:
2000 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
2001 }
2002 sk = sk_nulls_next(st->syn_wait_sk);
2003 st->state = TCP_SEQ_STATE_LISTENING;
2004 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2005 } else {
2006 icsk = inet_csk(sk);
2007 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2008 if (reqsk_queue_len(&icsk->icsk_accept_queue))
2009 goto start_req;
2010 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2011 sk = sk_nulls_next(sk);
2012 }
2013get_sk:
2014 sk_nulls_for_each_from(sk, node) {
2015 if (!net_eq(sock_net(sk), net))
2016 continue;
2017 if (sk->sk_family == st->family) {
2018 cur = sk;
2019 goto out;
2020 }
2021 icsk = inet_csk(sk);
2022 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2023 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
2024start_req:
2025 st->uid = sock_i_uid(sk);
2026 st->syn_wait_sk = sk;
2027 st->state = TCP_SEQ_STATE_OPENREQ;
2028 st->sbucket = 0;
2029 goto get_req;
2030 }
2031 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2032 }
2033 spin_unlock_bh(&ilb->lock);
2034 st->offset = 0;
2035 if (++st->bucket < INET_LHTABLE_SIZE) {
2036 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2037 spin_lock_bh(&ilb->lock);
2038 sk = sk_nulls_head(&ilb->head);
2039 goto get_sk;
2040 }
2041 cur = NULL;
2042out:
2043 return cur;
2044}
2045
2046static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
2047{
2048 struct tcp_iter_state *st = seq->private;
2049 void *rc;
2050
2051 st->bucket = 0;
2052 st->offset = 0;
2053 rc = listening_get_next(seq, NULL);
2054
2055 while (rc && *pos) {
2056 rc = listening_get_next(seq, rc);
2057 --*pos;
2058 }
2059 return rc;
2060}
2061
2062static inline int empty_bucket(struct tcp_iter_state *st)
2063{
2064 return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
2065 hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
2066}
2067
2068
2069
2070
2071
2072static void *established_get_first(struct seq_file *seq)
2073{
2074 struct tcp_iter_state *st = seq->private;
2075 struct net *net = seq_file_net(seq);
2076 void *rc = NULL;
2077
2078 st->offset = 0;
2079 for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
2080 struct sock *sk;
2081 struct hlist_nulls_node *node;
2082 struct inet_timewait_sock *tw;
2083 spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
2084
2085
2086 if (empty_bucket(st))
2087 continue;
2088
2089 spin_lock_bh(lock);
2090 sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
2091 if (sk->sk_family != st->family ||
2092 !net_eq(sock_net(sk), net)) {
2093 continue;
2094 }
2095 rc = sk;
2096 goto out;
2097 }
2098 st->state = TCP_SEQ_STATE_TIME_WAIT;
2099 inet_twsk_for_each(tw, node,
2100 &tcp_hashinfo.ehash[st->bucket].twchain) {
2101 if (tw->tw_family != st->family ||
2102 !net_eq(twsk_net(tw), net)) {
2103 continue;
2104 }
2105 rc = tw;
2106 goto out;
2107 }
2108 spin_unlock_bh(lock);
2109 st->state = TCP_SEQ_STATE_ESTABLISHED;
2110 }
2111out:
2112 return rc;
2113}
2114
2115static void *established_get_next(struct seq_file *seq, void *cur)
2116{
2117 struct sock *sk = cur;
2118 struct inet_timewait_sock *tw;
2119 struct hlist_nulls_node *node;
2120 struct tcp_iter_state *st = seq->private;
2121 struct net *net = seq_file_net(seq);
2122
2123 ++st->num;
2124 ++st->offset;
2125
2126 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2127 tw = cur;
2128 tw = tw_next(tw);
2129get_tw:
2130 while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
2131 tw = tw_next(tw);
2132 }
2133 if (tw) {
2134 cur = tw;
2135 goto out;
2136 }
2137 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2138 st->state = TCP_SEQ_STATE_ESTABLISHED;
2139
2140
2141 st->offset = 0;
2142 while (++st->bucket <= tcp_hashinfo.ehash_mask &&
2143 empty_bucket(st))
2144 ;
2145 if (st->bucket > tcp_hashinfo.ehash_mask)
2146 return NULL;
2147
2148 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2149 sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
2150 } else
2151 sk = sk_nulls_next(sk);
2152
2153 sk_nulls_for_each_from(sk, node) {
2154 if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
2155 goto found;
2156 }
2157
2158 st->state = TCP_SEQ_STATE_TIME_WAIT;
2159 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
2160 goto get_tw;
2161found:
2162 cur = sk;
2163out:
2164 return cur;
2165}
2166
2167static void *established_get_idx(struct seq_file *seq, loff_t pos)
2168{
2169 struct tcp_iter_state *st = seq->private;
2170 void *rc;
2171
2172 st->bucket = 0;
2173 rc = established_get_first(seq);
2174
2175 while (rc && pos) {
2176 rc = established_get_next(seq, rc);
2177 --pos;
2178 }
2179 return rc;
2180}
2181
2182static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2183{
2184 void *rc;
2185 struct tcp_iter_state *st = seq->private;
2186
2187 st->state = TCP_SEQ_STATE_LISTENING;
2188 rc = listening_get_idx(seq, &pos);
2189
2190 if (!rc) {
2191 st->state = TCP_SEQ_STATE_ESTABLISHED;
2192 rc = established_get_idx(seq, pos);
2193 }
2194
2195 return rc;
2196}
2197
2198static void *tcp_seek_last_pos(struct seq_file *seq)
2199{
2200 struct tcp_iter_state *st = seq->private;
2201 int offset = st->offset;
2202 int orig_num = st->num;
2203 void *rc = NULL;
2204
2205 switch (st->state) {
2206 case TCP_SEQ_STATE_OPENREQ:
2207 case TCP_SEQ_STATE_LISTENING:
2208 if (st->bucket >= INET_LHTABLE_SIZE)
2209 break;
2210 st->state = TCP_SEQ_STATE_LISTENING;
2211 rc = listening_get_next(seq, NULL);
2212 while (offset-- && rc)
2213 rc = listening_get_next(seq, rc);
2214 if (rc)
2215 break;
2216 st->bucket = 0;
2217
2218 case TCP_SEQ_STATE_ESTABLISHED:
2219 case TCP_SEQ_STATE_TIME_WAIT:
2220 st->state = TCP_SEQ_STATE_ESTABLISHED;
2221 if (st->bucket > tcp_hashinfo.ehash_mask)
2222 break;
2223 rc = established_get_first(seq);
2224 while (offset-- && rc)
2225 rc = established_get_next(seq, rc);
2226 }
2227
2228 st->num = orig_num;
2229
2230 return rc;
2231}
2232
2233static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2234{
2235 struct tcp_iter_state *st = seq->private;
2236 void *rc;
2237
2238 if (*pos && *pos == st->last_pos) {
2239 rc = tcp_seek_last_pos(seq);
2240 if (rc)
2241 goto out;
2242 }
2243
2244 st->state = TCP_SEQ_STATE_LISTENING;
2245 st->num = 0;
2246 st->bucket = 0;
2247 st->offset = 0;
2248 rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2249
2250out:
2251 st->last_pos = *pos;
2252 return rc;
2253}
2254
2255static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2256{
2257 struct tcp_iter_state *st = seq->private;
2258 void *rc = NULL;
2259
2260 if (v == SEQ_START_TOKEN) {
2261 rc = tcp_get_idx(seq, 0);
2262 goto out;
2263 }
2264
2265 switch (st->state) {
2266 case TCP_SEQ_STATE_OPENREQ:
2267 case TCP_SEQ_STATE_LISTENING:
2268 rc = listening_get_next(seq, v);
2269 if (!rc) {
2270 st->state = TCP_SEQ_STATE_ESTABLISHED;
2271 st->bucket = 0;
2272 st->offset = 0;
2273 rc = established_get_first(seq);
2274 }
2275 break;
2276 case TCP_SEQ_STATE_ESTABLISHED:
2277 case TCP_SEQ_STATE_TIME_WAIT:
2278 rc = established_get_next(seq, v);
2279 break;
2280 }
2281out:
2282 ++*pos;
2283 st->last_pos = *pos;
2284 return rc;
2285}
2286
2287static void tcp_seq_stop(struct seq_file *seq, void *v)
2288{
2289 struct tcp_iter_state *st = seq->private;
2290
2291 switch (st->state) {
2292 case TCP_SEQ_STATE_OPENREQ:
2293 if (v) {
2294 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2295 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2296 }
2297 case TCP_SEQ_STATE_LISTENING:
2298 if (v != SEQ_START_TOKEN)
2299 spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
2300 break;
2301 case TCP_SEQ_STATE_TIME_WAIT:
2302 case TCP_SEQ_STATE_ESTABLISHED:
2303 if (v)
2304 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2305 break;
2306 }
2307}
2308
2309static int tcp_seq_open(struct inode *inode, struct file *file)
2310{
2311 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
2312 struct tcp_iter_state *s;
2313 int err;
2314
2315 err = seq_open_net(inode, file, &afinfo->seq_ops,
2316 sizeof(struct tcp_iter_state));
2317 if (err < 0)
2318 return err;
2319
2320 s = ((struct seq_file *)file->private_data)->private;
2321 s->family = afinfo->family;
2322 s->last_pos = 0;
2323 return 0;
2324}
2325
2326int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
2327{
2328 int rc = 0;
2329 struct proc_dir_entry *p;
2330
2331 afinfo->seq_fops.open = tcp_seq_open;
2332 afinfo->seq_fops.read = seq_read;
2333 afinfo->seq_fops.llseek = seq_lseek;
2334 afinfo->seq_fops.release = seq_release_net;
2335
2336 afinfo->seq_ops.start = tcp_seq_start;
2337 afinfo->seq_ops.next = tcp_seq_next;
2338 afinfo->seq_ops.stop = tcp_seq_stop;
2339
2340 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2341 &afinfo->seq_fops, afinfo);
2342 if (!p)
2343 rc = -ENOMEM;
2344 return rc;
2345}
2346EXPORT_SYMBOL(tcp_proc_register);
2347
2348void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
2349{
2350 proc_net_remove(net, afinfo->name);
2351}
2352EXPORT_SYMBOL(tcp_proc_unregister);
2353
2354static void get_openreq4(struct sock *sk, struct request_sock *req,
2355 struct seq_file *f, int i, int uid, int *len)
2356{
2357 const struct inet_request_sock *ireq = inet_rsk(req);
2358 int ttd = req->expires - jiffies;
2359
2360 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2361 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
2362 i,
2363 ireq->loc_addr,
2364 ntohs(inet_sk(sk)->inet_sport),
2365 ireq->rmt_addr,
2366 ntohs(ireq->rmt_port),
2367 TCP_SYN_RECV,
2368 0, 0,
2369 1,
2370 jiffies_to_clock_t(ttd),
2371 req->retrans,
2372 uid,
2373 0,
2374 0,
2375 atomic_read(&sk->sk_refcnt),
2376 req,
2377 len);
2378}
2379
2380static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
2381{
2382 int timer_active;
2383 unsigned long timer_expires;
2384 struct tcp_sock *tp = tcp_sk(sk);
2385 const struct inet_connection_sock *icsk = inet_csk(sk);
2386 struct inet_sock *inet = inet_sk(sk);
2387 __be32 dest = inet->inet_daddr;
2388 __be32 src = inet->inet_rcv_saddr;
2389 __u16 destp = ntohs(inet->inet_dport);
2390 __u16 srcp = ntohs(inet->inet_sport);
2391 int rx_queue;
2392
2393 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2394 timer_active = 1;
2395 timer_expires = icsk->icsk_timeout;
2396 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2397 timer_active = 4;
2398 timer_expires = icsk->icsk_timeout;
2399 } else if (timer_pending(&sk->sk_timer)) {
2400 timer_active = 2;
2401 timer_expires = sk->sk_timer.expires;
2402 } else {
2403 timer_active = 0;
2404 timer_expires = jiffies;
2405 }
2406
2407 if (sk->sk_state == TCP_LISTEN)
2408 rx_queue = sk->sk_ack_backlog;
2409 else
2410
2411
2412
2413 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
2414
2415 seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2416 "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
2417 i, src, srcp, dest, destp, sk->sk_state,
2418 tp->write_seq - tp->snd_una,
2419 rx_queue,
2420 timer_active,
2421 jiffies_to_clock_t(timer_expires - jiffies),
2422 icsk->icsk_retransmits,
2423 sock_i_uid(sk),
2424 icsk->icsk_probes_out,
2425 sock_i_ino(sk),
2426 atomic_read(&sk->sk_refcnt), sk,
2427 jiffies_to_clock_t(icsk->icsk_rto),
2428 jiffies_to_clock_t(icsk->icsk_ack.ato),
2429 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
2430 tp->snd_cwnd,
2431 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
2432 len);
2433}
2434
2435static void get_timewait4_sock(struct inet_timewait_sock *tw,
2436 struct seq_file *f, int i, int *len)
2437{
2438 __be32 dest, src;
2439 __u16 destp, srcp;
2440 int ttd = tw->tw_ttd - jiffies;
2441
2442 if (ttd < 0)
2443 ttd = 0;
2444
2445 dest = tw->tw_daddr;
2446 src = tw->tw_rcv_saddr;
2447 destp = ntohs(tw->tw_dport);
2448 srcp = ntohs(tw->tw_sport);
2449
2450 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2451 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
2452 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2453 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2454 atomic_read(&tw->tw_refcnt), tw, len);
2455}
2456
2457#define TMPSZ 150
2458
2459static int tcp4_seq_show(struct seq_file *seq, void *v)
2460{
2461 struct tcp_iter_state *st;
2462 int len;
2463
2464 if (v == SEQ_START_TOKEN) {
2465 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2466 " sl local_address rem_address st tx_queue "
2467 "rx_queue tr tm->when retrnsmt uid timeout "
2468 "inode");
2469 goto out;
2470 }
2471 st = seq->private;
2472
2473 switch (st->state) {
2474 case TCP_SEQ_STATE_LISTENING:
2475 case TCP_SEQ_STATE_ESTABLISHED:
2476 get_tcp4_sock(v, seq, st->num, &len);
2477 break;
2478 case TCP_SEQ_STATE_OPENREQ:
2479 get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
2480 break;
2481 case TCP_SEQ_STATE_TIME_WAIT:
2482 get_timewait4_sock(v, seq, st->num, &len);
2483 break;
2484 }
2485 seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
2486out:
2487 return 0;
2488}
2489
2490static struct tcp_seq_afinfo tcp4_seq_afinfo = {
2491 .name = "tcp",
2492 .family = AF_INET,
2493 .seq_fops = {
2494 .owner = THIS_MODULE,
2495 },
2496 .seq_ops = {
2497 .show = tcp4_seq_show,
2498 },
2499};
2500
2501static int __net_init tcp4_proc_init_net(struct net *net)
2502{
2503 return tcp_proc_register(net, &tcp4_seq_afinfo);
2504}
2505
2506static void __net_exit tcp4_proc_exit_net(struct net *net)
2507{
2508 tcp_proc_unregister(net, &tcp4_seq_afinfo);
2509}
2510
2511static struct pernet_operations tcp4_net_ops = {
2512 .init = tcp4_proc_init_net,
2513 .exit = tcp4_proc_exit_net,
2514};
2515
2516int __init tcp4_proc_init(void)
2517{
2518 return register_pernet_subsys(&tcp4_net_ops);
2519}
2520
2521void tcp4_proc_exit(void)
2522{
2523 unregister_pernet_subsys(&tcp4_net_ops);
2524}
2525#endif
2526
2527struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2528{
2529 struct iphdr *iph = skb_gro_network_header(skb);
2530
2531 switch (skb->ip_summed) {
2532 case CHECKSUM_COMPLETE:
2533 if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
2534 skb->csum)) {
2535 skb->ip_summed = CHECKSUM_UNNECESSARY;
2536 break;
2537 }
2538
2539
2540 case CHECKSUM_NONE:
2541 NAPI_GRO_CB(skb)->flush = 1;
2542 return NULL;
2543 }
2544
2545 return tcp_gro_receive(head, skb);
2546}
2547
2548int tcp4_gro_complete(struct sk_buff *skb)
2549{
2550 struct iphdr *iph = ip_hdr(skb);
2551 struct tcphdr *th = tcp_hdr(skb);
2552
2553 th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
2554 iph->saddr, iph->daddr, 0);
2555 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
2556
2557 return tcp_gro_complete(skb);
2558}
2559
2560struct proto tcp_prot = {
2561 .name = "TCP",
2562 .owner = THIS_MODULE,
2563 .close = tcp_close,
2564 .connect = tcp_v4_connect,
2565 .disconnect = tcp_disconnect,
2566 .accept = inet_csk_accept,
2567 .ioctl = tcp_ioctl,
2568 .init = tcp_v4_init_sock,
2569 .destroy = tcp_v4_destroy_sock,
2570 .shutdown = tcp_shutdown,
2571 .setsockopt = tcp_setsockopt,
2572 .getsockopt = tcp_getsockopt,
2573 .recvmsg = tcp_recvmsg,
2574 .sendmsg = tcp_sendmsg,
2575 .sendpage = tcp_sendpage,
2576 .backlog_rcv = tcp_v4_do_rcv,
2577 .hash = inet_hash,
2578 .unhash = inet_unhash,
2579 .get_port = inet_csk_get_port,
2580 .enter_memory_pressure = tcp_enter_memory_pressure,
2581 .sockets_allocated = &tcp_sockets_allocated,
2582 .orphan_count = &tcp_orphan_count,
2583 .memory_allocated = &tcp_memory_allocated,
2584 .memory_pressure = &tcp_memory_pressure,
2585 .sysctl_mem = sysctl_tcp_mem,
2586 .sysctl_wmem = sysctl_tcp_wmem,
2587 .sysctl_rmem = sysctl_tcp_rmem,
2588 .max_header = MAX_TCP_HEADER,
2589 .obj_size = sizeof(struct tcp_sock),
2590 .slab_flags = SLAB_DESTROY_BY_RCU,
2591 .twsk_prot = &tcp_timewait_sock_ops,
2592 .rsk_prot = &tcp_request_sock_ops,
2593 .h.hashinfo = &tcp_hashinfo,
2594 .no_autobind = true,
2595#ifdef CONFIG_COMPAT
2596 .compat_setsockopt = compat_tcp_setsockopt,
2597 .compat_getsockopt = compat_tcp_getsockopt,
2598#endif
2599};
2600EXPORT_SYMBOL(tcp_prot);
2601
2602
2603static int __net_init tcp_sk_init(struct net *net)
2604{
2605 return inet_ctl_sock_create(&net->ipv4.tcp_sock,
2606 PF_INET, SOCK_RAW, IPPROTO_TCP, net);
2607}
2608
2609static void __net_exit tcp_sk_exit(struct net *net)
2610{
2611 inet_ctl_sock_destroy(net->ipv4.tcp_sock);
2612}
2613
2614static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
2615{
2616 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
2617}
2618
2619static struct pernet_operations __net_initdata tcp_sk_ops = {
2620 .init = tcp_sk_init,
2621 .exit = tcp_sk_exit,
2622 .exit_batch = tcp_sk_exit_batch,
2623};
2624
2625void __init tcp_v4_init(void)
2626{
2627 inet_hashinfo_init(&tcp_hashinfo);
2628 if (register_pernet_subsys(&tcp_sk_ops))
2629 panic("Failed to create the TCP control socket.\n");
2630}
2631