tcp: account SYN-ACK timeouts & retransmissions
[linux-3.10.git] / net / ipv6 / tcp_ipv6.c
1 /*
2  *      TCP over IPv6
3  *      Linux INET6 implementation
4  *
5  *      Authors:
6  *      Pedro Roque             <roque@di.fc.ul.pt>
7  *
8  *      Based on:
9  *      linux/net/ipv4/tcp.c
10  *      linux/net/ipv4/tcp_input.c
11  *      linux/net/ipv4/tcp_output.c
12  *
13  *      Fixes:
14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
17  *                                      a single port at the same time.
18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
19  *
20  *      This program is free software; you can redistribute it and/or
21  *      modify it under the terms of the GNU General Public License
22  *      as published by the Free Software Foundation; either version
23  *      2 of the License, or (at your option) any later version.
24  */
25
26 #include <linux/bottom_half.h>
27 #include <linux/module.h>
28 #include <linux/errno.h>
29 #include <linux/types.h>
30 #include <linux/socket.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/jiffies.h>
34 #include <linux/in.h>
35 #include <linux/in6.h>
36 #include <linux/netdevice.h>
37 #include <linux/init.h>
38 #include <linux/jhash.h>
39 #include <linux/ipsec.h>
40 #include <linux/times.h>
41
42 #include <linux/ipv6.h>
43 #include <linux/icmpv6.h>
44 #include <linux/random.h>
45
46 #include <net/tcp.h>
47 #include <net/ndisc.h>
48 #include <net/inet6_hashtables.h>
49 #include <net/inet6_connection_sock.h>
50 #include <net/ipv6.h>
51 #include <net/transp_v6.h>
52 #include <net/addrconf.h>
53 #include <net/ip6_route.h>
54 #include <net/ip6_checksum.h>
55 #include <net/inet_ecn.h>
56 #include <net/protocol.h>
57 #include <net/xfrm.h>
58 #include <net/snmp.h>
59 #include <net/dsfield.h>
60 #include <net/timewait_sock.h>
61 #include <net/netdma.h>
62 #include <net/inet_common.h>
63
64 #include <asm/uaccess.h>
65
66 #include <linux/proc_fs.h>
67 #include <linux/seq_file.h>
68
69 #include <linux/crypto.h>
70 #include <linux/scatterlist.h>
71
72 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
73 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
74                                       struct request_sock *req);
75
76 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
77
78 static const struct inet_connection_sock_af_ops ipv6_mapped;
79 static const struct inet_connection_sock_af_ops ipv6_specific;
80 #ifdef CONFIG_TCP_MD5SIG
81 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
82 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
83 #else
84 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
85                                                    struct in6_addr *addr)
86 {
87         return NULL;
88 }
89 #endif
90
91 static void tcp_v6_hash(struct sock *sk)
92 {
93         if (sk->sk_state != TCP_CLOSE) {
94                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
95                         tcp_prot.hash(sk);
96                         return;
97                 }
98                 local_bh_disable();
99                 __inet6_hash(sk, NULL);
100                 local_bh_enable();
101         }
102 }
103
104 static __inline__ __sum16 tcp_v6_check(int len,
105                                    struct in6_addr *saddr,
106                                    struct in6_addr *daddr,
107                                    __wsum base)
108 {
109         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
110 }
111
112 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
113 {
114         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
115                                             ipv6_hdr(skb)->saddr.s6_addr32,
116                                             tcp_hdr(skb)->dest,
117                                             tcp_hdr(skb)->source);
118 }
119
120 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
121                           int addr_len)
122 {
123         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
124         struct inet_sock *inet = inet_sk(sk);
125         struct inet_connection_sock *icsk = inet_csk(sk);
126         struct ipv6_pinfo *np = inet6_sk(sk);
127         struct tcp_sock *tp = tcp_sk(sk);
128         struct in6_addr *saddr = NULL, *final_p = NULL, final;
129         struct flowi fl;
130         struct dst_entry *dst;
131         int addr_type;
132         int err;
133
134         if (addr_len < SIN6_LEN_RFC2133)
135                 return -EINVAL;
136
137         if (usin->sin6_family != AF_INET6)
138                 return(-EAFNOSUPPORT);
139
140         memset(&fl, 0, sizeof(fl));
141
142         if (np->sndflow) {
143                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
144                 IP6_ECN_flow_init(fl.fl6_flowlabel);
145                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
146                         struct ip6_flowlabel *flowlabel;
147                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
148                         if (flowlabel == NULL)
149                                 return -EINVAL;
150                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
151                         fl6_sock_release(flowlabel);
152                 }
153         }
154
155         /*
156          *      connect() to INADDR_ANY means loopback (BSD'ism).
157          */
158
159         if(ipv6_addr_any(&usin->sin6_addr))
160                 usin->sin6_addr.s6_addr[15] = 0x1;
161
162         addr_type = ipv6_addr_type(&usin->sin6_addr);
163
164         if(addr_type & IPV6_ADDR_MULTICAST)
165                 return -ENETUNREACH;
166
167         if (addr_type&IPV6_ADDR_LINKLOCAL) {
168                 if (addr_len >= sizeof(struct sockaddr_in6) &&
169                     usin->sin6_scope_id) {
170                         /* If interface is set while binding, indices
171                          * must coincide.
172                          */
173                         if (sk->sk_bound_dev_if &&
174                             sk->sk_bound_dev_if != usin->sin6_scope_id)
175                                 return -EINVAL;
176
177                         sk->sk_bound_dev_if = usin->sin6_scope_id;
178                 }
179
180                 /* Connect to link-local address requires an interface */
181                 if (!sk->sk_bound_dev_if)
182                         return -EINVAL;
183         }
184
185         if (tp->rx_opt.ts_recent_stamp &&
186             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
187                 tp->rx_opt.ts_recent = 0;
188                 tp->rx_opt.ts_recent_stamp = 0;
189                 tp->write_seq = 0;
190         }
191
192         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
193         np->flow_label = fl.fl6_flowlabel;
194
195         /*
196          *      TCP over IPv4
197          */
198
199         if (addr_type == IPV6_ADDR_MAPPED) {
200                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
201                 struct sockaddr_in sin;
202
203                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
204
205                 if (__ipv6_only_sock(sk))
206                         return -ENETUNREACH;
207
208                 sin.sin_family = AF_INET;
209                 sin.sin_port = usin->sin6_port;
210                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
211
212                 icsk->icsk_af_ops = &ipv6_mapped;
213                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
214 #ifdef CONFIG_TCP_MD5SIG
215                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
216 #endif
217
218                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
219
220                 if (err) {
221                         icsk->icsk_ext_hdr_len = exthdrlen;
222                         icsk->icsk_af_ops = &ipv6_specific;
223                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
224 #ifdef CONFIG_TCP_MD5SIG
225                         tp->af_specific = &tcp_sock_ipv6_specific;
226 #endif
227                         goto failure;
228                 } else {
229                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
230                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
231                                                &np->rcv_saddr);
232                 }
233
234                 return err;
235         }
236
237         if (!ipv6_addr_any(&np->rcv_saddr))
238                 saddr = &np->rcv_saddr;
239
240         fl.proto = IPPROTO_TCP;
241         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
242         ipv6_addr_copy(&fl.fl6_src,
243                        (saddr ? saddr : &np->saddr));
244         fl.oif = sk->sk_bound_dev_if;
245         fl.mark = sk->sk_mark;
246         fl.fl_ip_dport = usin->sin6_port;
247         fl.fl_ip_sport = inet->inet_sport;
248
249         if (np->opt && np->opt->srcrt) {
250                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
251                 ipv6_addr_copy(&final, &fl.fl6_dst);
252                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
253                 final_p = &final;
254         }
255
256         security_sk_classify_flow(sk, &fl);
257
258         err = ip6_dst_lookup(sk, &dst, &fl);
259         if (err)
260                 goto failure;
261         if (final_p)
262                 ipv6_addr_copy(&fl.fl6_dst, final_p);
263
264         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
265         if (err < 0) {
266                 if (err == -EREMOTE)
267                         err = ip6_dst_blackhole(sk, &dst, &fl);
268                 if (err < 0)
269                         goto failure;
270         }
271
272         if (saddr == NULL) {
273                 saddr = &fl.fl6_src;
274                 ipv6_addr_copy(&np->rcv_saddr, saddr);
275         }
276
277         /* set the source address */
278         ipv6_addr_copy(&np->saddr, saddr);
279         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
280
281         sk->sk_gso_type = SKB_GSO_TCPV6;
282         __ip6_dst_store(sk, dst, NULL, NULL);
283
284         icsk->icsk_ext_hdr_len = 0;
285         if (np->opt)
286                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
287                                           np->opt->opt_nflen);
288
289         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
290
291         inet->inet_dport = usin->sin6_port;
292
293         tcp_set_state(sk, TCP_SYN_SENT);
294         err = inet6_hash_connect(&tcp_death_row, sk);
295         if (err)
296                 goto late_failure;
297
298         if (!tp->write_seq)
299                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
300                                                              np->daddr.s6_addr32,
301                                                              inet->inet_sport,
302                                                              inet->inet_dport);
303
304         err = tcp_connect(sk);
305         if (err)
306                 goto late_failure;
307
308         return 0;
309
310 late_failure:
311         tcp_set_state(sk, TCP_CLOSE);
312         __sk_dst_reset(sk);
313 failure:
314         inet->inet_dport = 0;
315         sk->sk_route_caps = 0;
316         return err;
317 }
318
319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
320                 u8 type, u8 code, int offset, __be32 info)
321 {
322         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
324         struct ipv6_pinfo *np;
325         struct sock *sk;
326         int err;
327         struct tcp_sock *tp;
328         __u32 seq;
329         struct net *net = dev_net(skb->dev);
330
331         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
332                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
333
334         if (sk == NULL) {
335                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
336                                    ICMP6_MIB_INERRORS);
337                 return;
338         }
339
340         if (sk->sk_state == TCP_TIME_WAIT) {
341                 inet_twsk_put(inet_twsk(sk));
342                 return;
343         }
344
345         bh_lock_sock(sk);
346         if (sock_owned_by_user(sk))
347                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
348
349         if (sk->sk_state == TCP_CLOSE)
350                 goto out;
351
352         tp = tcp_sk(sk);
353         seq = ntohl(th->seq);
354         if (sk->sk_state != TCP_LISTEN &&
355             !between(seq, tp->snd_una, tp->snd_nxt)) {
356                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
357                 goto out;
358         }
359
360         np = inet6_sk(sk);
361
362         if (type == ICMPV6_PKT_TOOBIG) {
363                 struct dst_entry *dst = NULL;
364
365                 if (sock_owned_by_user(sk))
366                         goto out;
367                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
368                         goto out;
369
370                 /* icmp should have updated the destination cache entry */
371                 dst = __sk_dst_check(sk, np->dst_cookie);
372
373                 if (dst == NULL) {
374                         struct inet_sock *inet = inet_sk(sk);
375                         struct flowi fl;
376
377                         /* BUGGG_FUTURE: Again, it is not clear how
378                            to handle rthdr case. Ignore this complexity
379                            for now.
380                          */
381                         memset(&fl, 0, sizeof(fl));
382                         fl.proto = IPPROTO_TCP;
383                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
384                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
385                         fl.oif = sk->sk_bound_dev_if;
386                         fl.mark = sk->sk_mark;
387                         fl.fl_ip_dport = inet->inet_dport;
388                         fl.fl_ip_sport = inet->inet_sport;
389                         security_skb_classify_flow(skb, &fl);
390
391                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
392                                 sk->sk_err_soft = -err;
393                                 goto out;
394                         }
395
396                         if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) {
397                                 sk->sk_err_soft = -err;
398                                 goto out;
399                         }
400
401                 } else
402                         dst_hold(dst);
403
404                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
405                         tcp_sync_mss(sk, dst_mtu(dst));
406                         tcp_simple_retransmit(sk);
407                 } /* else let the usual retransmit timer handle it */
408                 dst_release(dst);
409                 goto out;
410         }
411
412         icmpv6_err_convert(type, code, &err);
413
414         /* Might be for an request_sock */
415         switch (sk->sk_state) {
416                 struct request_sock *req, **prev;
417         case TCP_LISTEN:
418                 if (sock_owned_by_user(sk))
419                         goto out;
420
421                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
422                                            &hdr->saddr, inet6_iif(skb));
423                 if (!req)
424                         goto out;
425
426                 /* ICMPs are not backlogged, hence we cannot get
427                  * an established socket here.
428                  */
429                 WARN_ON(req->sk != NULL);
430
431                 if (seq != tcp_rsk(req)->snt_isn) {
432                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
433                         goto out;
434                 }
435
436                 inet_csk_reqsk_queue_drop(sk, req, prev);
437                 goto out;
438
439         case TCP_SYN_SENT:
440         case TCP_SYN_RECV:  /* Cannot happen.
441                                It can, it SYNs are crossed. --ANK */
442                 if (!sock_owned_by_user(sk)) {
443                         sk->sk_err = err;
444                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
445
446                         tcp_done(sk);
447                 } else
448                         sk->sk_err_soft = err;
449                 goto out;
450         }
451
452         if (!sock_owned_by_user(sk) && np->recverr) {
453                 sk->sk_err = err;
454                 sk->sk_error_report(sk);
455         } else
456                 sk->sk_err_soft = err;
457
458 out:
459         bh_unlock_sock(sk);
460         sock_put(sk);
461 }
462
463
464 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
465                               struct request_values *rvp)
466 {
467         struct inet6_request_sock *treq = inet6_rsk(req);
468         struct ipv6_pinfo *np = inet6_sk(sk);
469         struct sk_buff * skb;
470         struct ipv6_txoptions *opt = NULL;
471         struct in6_addr * final_p = NULL, final;
472         struct flowi fl;
473         struct dst_entry *dst;
474         int err = -1;
475
476         memset(&fl, 0, sizeof(fl));
477         fl.proto = IPPROTO_TCP;
478         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
479         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
480         fl.fl6_flowlabel = 0;
481         fl.oif = treq->iif;
482         fl.mark = sk->sk_mark;
483         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
484         fl.fl_ip_sport = inet_rsk(req)->loc_port;
485         security_req_classify_flow(req, &fl);
486
487         opt = np->opt;
488         if (opt && opt->srcrt) {
489                 struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
490                 ipv6_addr_copy(&final, &fl.fl6_dst);
491                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
492                 final_p = &final;
493         }
494
495         err = ip6_dst_lookup(sk, &dst, &fl);
496         if (err)
497                 goto done;
498         if (final_p)
499                 ipv6_addr_copy(&fl.fl6_dst, final_p);
500         if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
501                 goto done;
502
503         skb = tcp_make_synack(sk, dst, req, rvp);
504         if (skb) {
505                 struct tcphdr *th = tcp_hdr(skb);
506
507                 th->check = tcp_v6_check(skb->len,
508                                          &treq->loc_addr, &treq->rmt_addr,
509                                          csum_partial(th, skb->len, skb->csum));
510
511                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
512                 err = ip6_xmit(sk, skb, &fl, opt, 0);
513                 err = net_xmit_eval(err);
514         }
515
516 done:
517         if (opt && opt != np->opt)
518                 sock_kfree_s(sk, opt, opt->tot_len);
519         dst_release(dst);
520         return err;
521 }
522
523 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
524                              struct request_values *rvp)
525 {
526         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
527         return tcp_v6_send_synack(sk, req, rvp);
528 }
529
530 static inline void syn_flood_warning(struct sk_buff *skb)
531 {
532 #ifdef CONFIG_SYN_COOKIES
533         if (sysctl_tcp_syncookies)
534                 printk(KERN_INFO
535                        "TCPv6: Possible SYN flooding on port %d. "
536                        "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
537         else
538 #endif
539                 printk(KERN_INFO
540                        "TCPv6: Possible SYN flooding on port %d. "
541                        "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
542 }
543
544 static void tcp_v6_reqsk_destructor(struct request_sock *req)
545 {
546         kfree_skb(inet6_rsk(req)->pktopts);
547 }
548
549 #ifdef CONFIG_TCP_MD5SIG
550 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
551                                                    struct in6_addr *addr)
552 {
553         struct tcp_sock *tp = tcp_sk(sk);
554         int i;
555
556         BUG_ON(tp == NULL);
557
558         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
559                 return NULL;
560
561         for (i = 0; i < tp->md5sig_info->entries6; i++) {
562                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
563                         return &tp->md5sig_info->keys6[i].base;
564         }
565         return NULL;
566 }
567
568 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
569                                                 struct sock *addr_sk)
570 {
571         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
572 }
573
574 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
575                                                       struct request_sock *req)
576 {
577         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
578 }
579
580 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
581                              char *newkey, u8 newkeylen)
582 {
583         /* Add key to the list */
584         struct tcp_md5sig_key *key;
585         struct tcp_sock *tp = tcp_sk(sk);
586         struct tcp6_md5sig_key *keys;
587
588         key = tcp_v6_md5_do_lookup(sk, peer);
589         if (key) {
590                 /* modify existing entry - just update that one */
591                 kfree(key->key);
592                 key->key = newkey;
593                 key->keylen = newkeylen;
594         } else {
595                 /* reallocate new list if current one is full. */
596                 if (!tp->md5sig_info) {
597                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
598                         if (!tp->md5sig_info) {
599                                 kfree(newkey);
600                                 return -ENOMEM;
601                         }
602                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
603                 }
604                 if (tcp_alloc_md5sig_pool(sk) == NULL) {
605                         kfree(newkey);
606                         return -ENOMEM;
607                 }
608                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
609                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
610                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
611
612                         if (!keys) {
613                                 tcp_free_md5sig_pool();
614                                 kfree(newkey);
615                                 return -ENOMEM;
616                         }
617
618                         if (tp->md5sig_info->entries6)
619                                 memmove(keys, tp->md5sig_info->keys6,
620                                         (sizeof (tp->md5sig_info->keys6[0]) *
621                                          tp->md5sig_info->entries6));
622
623                         kfree(tp->md5sig_info->keys6);
624                         tp->md5sig_info->keys6 = keys;
625                         tp->md5sig_info->alloced6++;
626                 }
627
628                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
629                                peer);
630                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
631                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
632
633                 tp->md5sig_info->entries6++;
634         }
635         return 0;
636 }
637
638 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
639                                u8 *newkey, __u8 newkeylen)
640 {
641         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
642                                  newkey, newkeylen);
643 }
644
645 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
646 {
647         struct tcp_sock *tp = tcp_sk(sk);
648         int i;
649
650         for (i = 0; i < tp->md5sig_info->entries6; i++) {
651                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
652                         /* Free the key */
653                         kfree(tp->md5sig_info->keys6[i].base.key);
654                         tp->md5sig_info->entries6--;
655
656                         if (tp->md5sig_info->entries6 == 0) {
657                                 kfree(tp->md5sig_info->keys6);
658                                 tp->md5sig_info->keys6 = NULL;
659                                 tp->md5sig_info->alloced6 = 0;
660                         } else {
661                                 /* shrink the database */
662                                 if (tp->md5sig_info->entries6 != i)
663                                         memmove(&tp->md5sig_info->keys6[i],
664                                                 &tp->md5sig_info->keys6[i+1],
665                                                 (tp->md5sig_info->entries6 - i)
666                                                 * sizeof (tp->md5sig_info->keys6[0]));
667                         }
668                         tcp_free_md5sig_pool();
669                         return 0;
670                 }
671         }
672         return -ENOENT;
673 }
674
675 static void tcp_v6_clear_md5_list (struct sock *sk)
676 {
677         struct tcp_sock *tp = tcp_sk(sk);
678         int i;
679
680         if (tp->md5sig_info->entries6) {
681                 for (i = 0; i < tp->md5sig_info->entries6; i++)
682                         kfree(tp->md5sig_info->keys6[i].base.key);
683                 tp->md5sig_info->entries6 = 0;
684                 tcp_free_md5sig_pool();
685         }
686
687         kfree(tp->md5sig_info->keys6);
688         tp->md5sig_info->keys6 = NULL;
689         tp->md5sig_info->alloced6 = 0;
690
691         if (tp->md5sig_info->entries4) {
692                 for (i = 0; i < tp->md5sig_info->entries4; i++)
693                         kfree(tp->md5sig_info->keys4[i].base.key);
694                 tp->md5sig_info->entries4 = 0;
695                 tcp_free_md5sig_pool();
696         }
697
698         kfree(tp->md5sig_info->keys4);
699         tp->md5sig_info->keys4 = NULL;
700         tp->md5sig_info->alloced4 = 0;
701 }
702
703 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
704                                   int optlen)
705 {
706         struct tcp_md5sig cmd;
707         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
708         u8 *newkey;
709
710         if (optlen < sizeof(cmd))
711                 return -EINVAL;
712
713         if (copy_from_user(&cmd, optval, sizeof(cmd)))
714                 return -EFAULT;
715
716         if (sin6->sin6_family != AF_INET6)
717                 return -EINVAL;
718
719         if (!cmd.tcpm_keylen) {
720                 if (!tcp_sk(sk)->md5sig_info)
721                         return -ENOENT;
722                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
723                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
724                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
725         }
726
727         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
728                 return -EINVAL;
729
730         if (!tcp_sk(sk)->md5sig_info) {
731                 struct tcp_sock *tp = tcp_sk(sk);
732                 struct tcp_md5sig_info *p;
733
734                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
735                 if (!p)
736                         return -ENOMEM;
737
738                 tp->md5sig_info = p;
739                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
740         }
741
742         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
743         if (!newkey)
744                 return -ENOMEM;
745         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
746                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
747                                          newkey, cmd.tcpm_keylen);
748         }
749         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
750 }
751
752 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
753                                         struct in6_addr *daddr,
754                                         struct in6_addr *saddr, int nbytes)
755 {
756         struct tcp6_pseudohdr *bp;
757         struct scatterlist sg;
758
759         bp = &hp->md5_blk.ip6;
760         /* 1. TCP pseudo-header (RFC2460) */
761         ipv6_addr_copy(&bp->saddr, saddr);
762         ipv6_addr_copy(&bp->daddr, daddr);
763         bp->protocol = cpu_to_be32(IPPROTO_TCP);
764         bp->len = cpu_to_be32(nbytes);
765
766         sg_init_one(&sg, bp, sizeof(*bp));
767         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
768 }
769
770 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
771                                struct in6_addr *daddr, struct in6_addr *saddr,
772                                struct tcphdr *th)
773 {
774         struct tcp_md5sig_pool *hp;
775         struct hash_desc *desc;
776
777         hp = tcp_get_md5sig_pool();
778         if (!hp)
779                 goto clear_hash_noput;
780         desc = &hp->md5_desc;
781
782         if (crypto_hash_init(desc))
783                 goto clear_hash;
784         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
785                 goto clear_hash;
786         if (tcp_md5_hash_header(hp, th))
787                 goto clear_hash;
788         if (tcp_md5_hash_key(hp, key))
789                 goto clear_hash;
790         if (crypto_hash_final(desc, md5_hash))
791                 goto clear_hash;
792
793         tcp_put_md5sig_pool();
794         return 0;
795
796 clear_hash:
797         tcp_put_md5sig_pool();
798 clear_hash_noput:
799         memset(md5_hash, 0, 16);
800         return 1;
801 }
802
803 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
804                                struct sock *sk, struct request_sock *req,
805                                struct sk_buff *skb)
806 {
807         struct in6_addr *saddr, *daddr;
808         struct tcp_md5sig_pool *hp;
809         struct hash_desc *desc;
810         struct tcphdr *th = tcp_hdr(skb);
811
812         if (sk) {
813                 saddr = &inet6_sk(sk)->saddr;
814                 daddr = &inet6_sk(sk)->daddr;
815         } else if (req) {
816                 saddr = &inet6_rsk(req)->loc_addr;
817                 daddr = &inet6_rsk(req)->rmt_addr;
818         } else {
819                 struct ipv6hdr *ip6h = ipv6_hdr(skb);
820                 saddr = &ip6h->saddr;
821                 daddr = &ip6h->daddr;
822         }
823
824         hp = tcp_get_md5sig_pool();
825         if (!hp)
826                 goto clear_hash_noput;
827         desc = &hp->md5_desc;
828
829         if (crypto_hash_init(desc))
830                 goto clear_hash;
831
832         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
833                 goto clear_hash;
834         if (tcp_md5_hash_header(hp, th))
835                 goto clear_hash;
836         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
837                 goto clear_hash;
838         if (tcp_md5_hash_key(hp, key))
839                 goto clear_hash;
840         if (crypto_hash_final(desc, md5_hash))
841                 goto clear_hash;
842
843         tcp_put_md5sig_pool();
844         return 0;
845
846 clear_hash:
847         tcp_put_md5sig_pool();
848 clear_hash_noput:
849         memset(md5_hash, 0, 16);
850         return 1;
851 }
852
853 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
854 {
855         __u8 *hash_location = NULL;
856         struct tcp_md5sig_key *hash_expected;
857         struct ipv6hdr *ip6h = ipv6_hdr(skb);
858         struct tcphdr *th = tcp_hdr(skb);
859         int genhash;
860         u8 newhash[16];
861
862         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
863         hash_location = tcp_parse_md5sig_option(th);
864
865         /* We've parsed the options - do we have a hash? */
866         if (!hash_expected && !hash_location)
867                 return 0;
868
869         if (hash_expected && !hash_location) {
870                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
871                 return 1;
872         }
873
874         if (!hash_expected && hash_location) {
875                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
876                 return 1;
877         }
878
879         /* check the signature */
880         genhash = tcp_v6_md5_hash_skb(newhash,
881                                       hash_expected,
882                                       NULL, NULL, skb);
883
884         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
885                 if (net_ratelimit()) {
886                         printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
887                                genhash ? "failed" : "mismatch",
888                                &ip6h->saddr, ntohs(th->source),
889                                &ip6h->daddr, ntohs(th->dest));
890                 }
891                 return 1;
892         }
893         return 0;
894 }
895 #endif
896
897 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
898         .family         =       AF_INET6,
899         .obj_size       =       sizeof(struct tcp6_request_sock),
900         .rtx_syn_ack    =       tcp_v6_rtx_synack,
901         .send_ack       =       tcp_v6_reqsk_send_ack,
902         .destructor     =       tcp_v6_reqsk_destructor,
903         .send_reset     =       tcp_v6_send_reset,
904         .syn_ack_timeout =      tcp_syn_ack_timeout,
905 };
906
907 #ifdef CONFIG_TCP_MD5SIG
908 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
909         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
910         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
911 };
912 #endif
913
914 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
915         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
916         .twsk_unique    = tcp_twsk_unique,
917         .twsk_destructor= tcp_twsk_destructor,
918 };
919
920 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
921 {
922         struct ipv6_pinfo *np = inet6_sk(sk);
923         struct tcphdr *th = tcp_hdr(skb);
924
925         if (skb->ip_summed == CHECKSUM_PARTIAL) {
926                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
927                 skb->csum_start = skb_transport_header(skb) - skb->head;
928                 skb->csum_offset = offsetof(struct tcphdr, check);
929         } else {
930                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
931                                             csum_partial(th, th->doff<<2,
932                                                          skb->csum));
933         }
934 }
935
936 static int tcp_v6_gso_send_check(struct sk_buff *skb)
937 {
938         struct ipv6hdr *ipv6h;
939         struct tcphdr *th;
940
941         if (!pskb_may_pull(skb, sizeof(*th)))
942                 return -EINVAL;
943
944         ipv6h = ipv6_hdr(skb);
945         th = tcp_hdr(skb);
946
947         th->check = 0;
948         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
949                                      IPPROTO_TCP, 0);
950         skb->csum_start = skb_transport_header(skb) - skb->head;
951         skb->csum_offset = offsetof(struct tcphdr, check);
952         skb->ip_summed = CHECKSUM_PARTIAL;
953         return 0;
954 }
955
956 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
957                                          struct sk_buff *skb)
958 {
959         struct ipv6hdr *iph = skb_gro_network_header(skb);
960
961         switch (skb->ip_summed) {
962         case CHECKSUM_COMPLETE:
963                 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
964                                   skb->csum)) {
965                         skb->ip_summed = CHECKSUM_UNNECESSARY;
966                         break;
967                 }
968
969                 /* fall through */
970         case CHECKSUM_NONE:
971                 NAPI_GRO_CB(skb)->flush = 1;
972                 return NULL;
973         }
974
975         return tcp_gro_receive(head, skb);
976 }
977
978 static int tcp6_gro_complete(struct sk_buff *skb)
979 {
980         struct ipv6hdr *iph = ipv6_hdr(skb);
981         struct tcphdr *th = tcp_hdr(skb);
982
983         th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
984                                   &iph->saddr, &iph->daddr, 0);
985         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
986
987         return tcp_gro_complete(skb);
988 }
989
990 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
991                                  u32 ts, struct tcp_md5sig_key *key, int rst)
992 {
993         struct tcphdr *th = tcp_hdr(skb), *t1;
994         struct sk_buff *buff;
995         struct flowi fl;
996         struct net *net = dev_net(skb_dst(skb)->dev);
997         struct sock *ctl_sk = net->ipv6.tcp_sk;
998         unsigned int tot_len = sizeof(struct tcphdr);
999         struct dst_entry *dst;
1000         __be32 *topt;
1001
1002         if (ts)
1003                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1004 #ifdef CONFIG_TCP_MD5SIG
1005         if (key)
1006                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1007 #endif
1008
1009         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1010                          GFP_ATOMIC);
1011         if (buff == NULL)
1012                 return;
1013
1014         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1015
1016         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1017         skb_reset_transport_header(skb);
1018
1019         /* Swap the send and the receive. */
1020         memset(t1, 0, sizeof(*t1));
1021         t1->dest = th->source;
1022         t1->source = th->dest;
1023         t1->doff = tot_len / 4;
1024         t1->seq = htonl(seq);
1025         t1->ack_seq = htonl(ack);
1026         t1->ack = !rst || !th->ack;
1027         t1->rst = rst;
1028         t1->window = htons(win);
1029
1030         topt = (__be32 *)(t1 + 1);
1031
1032         if (ts) {
1033                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1034                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1035                 *topt++ = htonl(tcp_time_stamp);
1036                 *topt++ = htonl(ts);
1037         }
1038
1039 #ifdef CONFIG_TCP_MD5SIG
1040         if (key) {
1041                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1042                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1043                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1044                                     &ipv6_hdr(skb)->saddr,
1045                                     &ipv6_hdr(skb)->daddr, t1);
1046         }
1047 #endif
1048
1049         buff->csum = csum_partial(t1, tot_len, 0);
1050
1051         memset(&fl, 0, sizeof(fl));
1052         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1053         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1054
1055         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1056                                     tot_len, IPPROTO_TCP,
1057                                     buff->csum);
1058
1059         fl.proto = IPPROTO_TCP;
1060         fl.oif = inet6_iif(skb);
1061         fl.fl_ip_dport = t1->dest;
1062         fl.fl_ip_sport = t1->source;
1063         security_skb_classify_flow(skb, &fl);
1064
1065         /* Pass a socket to ip6_dst_lookup either it is for RST
1066          * Underlying function will use this to retrieve the network
1067          * namespace
1068          */
1069         if (!ip6_dst_lookup(ctl_sk, &dst, &fl)) {
1070                 if (xfrm_lookup(net, &dst, &fl, NULL, 0) >= 0) {
1071                         skb_dst_set(buff, dst);
1072                         ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1073                         TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1074                         if (rst)
1075                                 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1076                         return;
1077                 }
1078         }
1079
1080         kfree_skb(buff);
1081 }
1082
1083 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1084 {
1085         struct tcphdr *th = tcp_hdr(skb);
1086         u32 seq = 0, ack_seq = 0;
1087         struct tcp_md5sig_key *key = NULL;
1088
1089         if (th->rst)
1090                 return;
1091
1092         if (!ipv6_unicast_destination(skb))
1093                 return;
1094
1095 #ifdef CONFIG_TCP_MD5SIG
1096         if (sk)
1097                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1098 #endif
1099
1100         if (th->ack)
1101                 seq = ntohl(th->ack_seq);
1102         else
1103                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1104                           (th->doff << 2);
1105
1106         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1107 }
1108
1109 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1110                             struct tcp_md5sig_key *key)
1111 {
1112         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1113 }
1114
1115 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1116 {
1117         struct inet_timewait_sock *tw = inet_twsk(sk);
1118         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1119
1120         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1121                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1122                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1123
1124         inet_twsk_put(tw);
1125 }
1126
1127 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1128                                   struct request_sock *req)
1129 {
1130         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1131                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1132 }
1133
1134
1135 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1136 {
1137         struct request_sock *req, **prev;
1138         const struct tcphdr *th = tcp_hdr(skb);
1139         struct sock *nsk;
1140
1141         /* Find possible connection requests. */
1142         req = inet6_csk_search_req(sk, &prev, th->source,
1143                                    &ipv6_hdr(skb)->saddr,
1144                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1145         if (req)
1146                 return tcp_check_req(sk, skb, req, prev);
1147
1148         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1149                         &ipv6_hdr(skb)->saddr, th->source,
1150                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1151
1152         if (nsk) {
1153                 if (nsk->sk_state != TCP_TIME_WAIT) {
1154                         bh_lock_sock(nsk);
1155                         return nsk;
1156                 }
1157                 inet_twsk_put(inet_twsk(nsk));
1158                 return NULL;
1159         }
1160
1161 #ifdef CONFIG_SYN_COOKIES
1162         if (!th->rst && !th->syn && th->ack)
1163                 sk = cookie_v6_check(sk, skb);
1164 #endif
1165         return sk;
1166 }
1167
1168 /* FIXME: this is substantially similar to the ipv4 code.
1169  * Can some kind of merge be done? -- erics
1170  */
1171 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1172 {
1173         struct tcp_extend_values tmp_ext;
1174         struct tcp_options_received tmp_opt;
1175         u8 *hash_location;
1176         struct request_sock *req;
1177         struct inet6_request_sock *treq;
1178         struct ipv6_pinfo *np = inet6_sk(sk);
1179         struct tcp_sock *tp = tcp_sk(sk);
1180         __u32 isn = TCP_SKB_CB(skb)->when;
1181 #ifdef CONFIG_SYN_COOKIES
1182         int want_cookie = 0;
1183 #else
1184 #define want_cookie 0
1185 #endif
1186
1187         if (skb->protocol == htons(ETH_P_IP))
1188                 return tcp_v4_conn_request(sk, skb);
1189
1190         if (!ipv6_unicast_destination(skb))
1191                 goto drop;
1192
1193         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1194                 if (net_ratelimit())
1195                         syn_flood_warning(skb);
1196 #ifdef CONFIG_SYN_COOKIES
1197                 if (sysctl_tcp_syncookies)
1198                         want_cookie = 1;
1199                 else
1200 #endif
1201                 goto drop;
1202         }
1203
1204         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1205                 goto drop;
1206
1207         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1208         if (req == NULL)
1209                 goto drop;
1210
1211 #ifdef CONFIG_TCP_MD5SIG
1212         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1213 #endif
1214
1215         tcp_clear_options(&tmp_opt);
1216         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1217         tmp_opt.user_mss = tp->rx_opt.user_mss;
1218         tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1219
1220         if (tmp_opt.cookie_plus > 0 &&
1221             tmp_opt.saw_tstamp &&
1222             !tp->rx_opt.cookie_out_never &&
1223             (sysctl_tcp_cookie_size > 0 ||
1224              (tp->cookie_values != NULL &&
1225               tp->cookie_values->cookie_desired > 0))) {
1226                 u8 *c;
1227                 u32 *d;
1228                 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1229                 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1230
1231                 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1232                         goto drop_and_free;
1233
1234                 /* Secret recipe starts with IP addresses */
1235                 d = &ipv6_hdr(skb)->daddr.s6_addr32[0];
1236                 *mess++ ^= *d++;
1237                 *mess++ ^= *d++;
1238                 *mess++ ^= *d++;
1239                 *mess++ ^= *d++;
1240                 d = &ipv6_hdr(skb)->saddr.s6_addr32[0];
1241                 *mess++ ^= *d++;
1242                 *mess++ ^= *d++;
1243                 *mess++ ^= *d++;
1244                 *mess++ ^= *d++;
1245
1246                 /* plus variable length Initiator Cookie */
1247                 c = (u8 *)mess;
1248                 while (l-- > 0)
1249                         *c++ ^= *hash_location++;
1250
1251 #ifdef CONFIG_SYN_COOKIES
1252                 want_cookie = 0;        /* not our kind of cookie */
1253 #endif
1254                 tmp_ext.cookie_out_never = 0; /* false */
1255                 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1256         } else if (!tp->rx_opt.cookie_in_always) {
1257                 /* redundant indications, but ensure initialization. */
1258                 tmp_ext.cookie_out_never = 1; /* true */
1259                 tmp_ext.cookie_plus = 0;
1260         } else {
1261                 goto drop_and_free;
1262         }
1263         tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1264
1265         if (want_cookie && !tmp_opt.saw_tstamp)
1266                 tcp_clear_options(&tmp_opt);
1267
1268         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1269         tcp_openreq_init(req, &tmp_opt, skb);
1270
1271         treq = inet6_rsk(req);
1272         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1273         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1274         if (!want_cookie)
1275                 TCP_ECN_create_request(req, tcp_hdr(skb));
1276
1277         if (want_cookie) {
1278                 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1279                 req->cookie_ts = tmp_opt.tstamp_ok;
1280         } else if (!isn) {
1281                 if (ipv6_opt_accepted(sk, skb) ||
1282                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1283                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1284                         atomic_inc(&skb->users);
1285                         treq->pktopts = skb;
1286                 }
1287                 treq->iif = sk->sk_bound_dev_if;
1288
1289                 /* So that link locals have meaning */
1290                 if (!sk->sk_bound_dev_if &&
1291                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1292                         treq->iif = inet6_iif(skb);
1293
1294                 isn = tcp_v6_init_sequence(skb);
1295         }
1296         tcp_rsk(req)->snt_isn = isn;
1297
1298         security_inet_conn_request(sk, skb, req);
1299
1300         if (tcp_v6_send_synack(sk, req,
1301                                (struct request_values *)&tmp_ext) ||
1302             want_cookie)
1303                 goto drop_and_free;
1304
1305         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1306         return 0;
1307
1308 drop_and_free:
1309         reqsk_free(req);
1310 drop:
1311         return 0; /* don't send reset */
1312 }
1313
1314 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1315                                           struct request_sock *req,
1316                                           struct dst_entry *dst)
1317 {
1318         struct inet6_request_sock *treq;
1319         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1320         struct tcp6_sock *newtcp6sk;
1321         struct inet_sock *newinet;
1322         struct tcp_sock *newtp;
1323         struct sock *newsk;
1324         struct ipv6_txoptions *opt;
1325 #ifdef CONFIG_TCP_MD5SIG
1326         struct tcp_md5sig_key *key;
1327 #endif
1328
1329         if (skb->protocol == htons(ETH_P_IP)) {
1330                 /*
1331                  *      v6 mapped
1332                  */
1333
1334                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1335
1336                 if (newsk == NULL)
1337                         return NULL;
1338
1339                 newtcp6sk = (struct tcp6_sock *)newsk;
1340                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1341
1342                 newinet = inet_sk(newsk);
1343                 newnp = inet6_sk(newsk);
1344                 newtp = tcp_sk(newsk);
1345
1346                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1347
1348                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1349
1350                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1351
1352                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1353
1354                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1355                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1356 #ifdef CONFIG_TCP_MD5SIG
1357                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1358 #endif
1359
1360                 newnp->pktoptions  = NULL;
1361                 newnp->opt         = NULL;
1362                 newnp->mcast_oif   = inet6_iif(skb);
1363                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1364
1365                 /*
1366                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1367                  * here, tcp_create_openreq_child now does this for us, see the comment in
1368                  * that function for the gory details. -acme
1369                  */
1370
1371                 /* It is tricky place. Until this moment IPv4 tcp
1372                    worked with IPv6 icsk.icsk_af_ops.
1373                    Sync it now.
1374                  */
1375                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1376
1377                 return newsk;
1378         }
1379
1380         treq = inet6_rsk(req);
1381         opt = np->opt;
1382
1383         if (sk_acceptq_is_full(sk))
1384                 goto out_overflow;
1385
1386         if (dst == NULL) {
1387                 struct in6_addr *final_p = NULL, final;
1388                 struct flowi fl;
1389
1390                 memset(&fl, 0, sizeof(fl));
1391                 fl.proto = IPPROTO_TCP;
1392                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1393                 if (opt && opt->srcrt) {
1394                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1395                         ipv6_addr_copy(&final, &fl.fl6_dst);
1396                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1397                         final_p = &final;
1398                 }
1399                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1400                 fl.oif = sk->sk_bound_dev_if;
1401                 fl.mark = sk->sk_mark;
1402                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1403                 fl.fl_ip_sport = inet_rsk(req)->loc_port;
1404                 security_req_classify_flow(req, &fl);
1405
1406                 if (ip6_dst_lookup(sk, &dst, &fl))
1407                         goto out;
1408
1409                 if (final_p)
1410                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1411
1412                 if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
1413                         goto out;
1414         }
1415
1416         newsk = tcp_create_openreq_child(sk, req, skb);
1417         if (newsk == NULL)
1418                 goto out;
1419
1420         /*
1421          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1422          * count here, tcp_create_openreq_child now does this for us, see the
1423          * comment in that function for the gory details. -acme
1424          */
1425
1426         newsk->sk_gso_type = SKB_GSO_TCPV6;
1427         __ip6_dst_store(newsk, dst, NULL, NULL);
1428
1429         newtcp6sk = (struct tcp6_sock *)newsk;
1430         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1431
1432         newtp = tcp_sk(newsk);
1433         newinet = inet_sk(newsk);
1434         newnp = inet6_sk(newsk);
1435
1436         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1437
1438         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1439         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1440         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1441         newsk->sk_bound_dev_if = treq->iif;
1442
1443         /* Now IPv6 options...
1444
1445            First: no IPv4 options.
1446          */
1447         newinet->opt = NULL;
1448         newnp->ipv6_fl_list = NULL;
1449
1450         /* Clone RX bits */
1451         newnp->rxopt.all = np->rxopt.all;
1452
1453         /* Clone pktoptions received with SYN */
1454         newnp->pktoptions = NULL;
1455         if (treq->pktopts != NULL) {
1456                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1457                 kfree_skb(treq->pktopts);
1458                 treq->pktopts = NULL;
1459                 if (newnp->pktoptions)
1460                         skb_set_owner_r(newnp->pktoptions, newsk);
1461         }
1462         newnp->opt        = NULL;
1463         newnp->mcast_oif  = inet6_iif(skb);
1464         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1465
1466         /* Clone native IPv6 options from listening socket (if any)
1467
1468            Yes, keeping reference count would be much more clever,
1469            but we make one more one thing there: reattach optmem
1470            to newsk.
1471          */
1472         if (opt) {
1473                 newnp->opt = ipv6_dup_options(newsk, opt);
1474                 if (opt != np->opt)
1475                         sock_kfree_s(sk, opt, opt->tot_len);
1476         }
1477
1478         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1479         if (newnp->opt)
1480                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1481                                                      newnp->opt->opt_flen);
1482
1483         tcp_mtup_init(newsk);
1484         tcp_sync_mss(newsk, dst_mtu(dst));
1485         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1486         tcp_initialize_rcv_mss(newsk);
1487
1488         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1489         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1490
1491 #ifdef CONFIG_TCP_MD5SIG
1492         /* Copy over the MD5 key from the original socket */
1493         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1494                 /* We're using one, so create a matching key
1495                  * on the newsk structure. If we fail to get
1496                  * memory, then we end up not copying the key
1497                  * across. Shucks.
1498                  */
1499                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1500                 if (newkey != NULL)
1501                         tcp_v6_md5_do_add(newsk, &newnp->daddr,
1502                                           newkey, key->keylen);
1503         }
1504 #endif
1505
1506         __inet6_hash(newsk, NULL);
1507         __inet_inherit_port(sk, newsk);
1508
1509         return newsk;
1510
1511 out_overflow:
1512         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1513 out:
1514         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1515         if (opt && opt != np->opt)
1516                 sock_kfree_s(sk, opt, opt->tot_len);
1517         dst_release(dst);
1518         return NULL;
1519 }
1520
1521 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1522 {
1523         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1524                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1525                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1526                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1527                         return 0;
1528                 }
1529         }
1530
1531         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1532                                               &ipv6_hdr(skb)->saddr,
1533                                               &ipv6_hdr(skb)->daddr, 0));
1534
1535         if (skb->len <= 76) {
1536                 return __skb_checksum_complete(skb);
1537         }
1538         return 0;
1539 }
1540
1541 /* The socket must have it's spinlock held when we get
1542  * here.
1543  *
1544  * We have a potential double-lock case here, so even when
1545  * doing backlog processing we use the BH locking scheme.
1546  * This is because we cannot sleep with the original spinlock
1547  * held.
1548  */
1549 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1550 {
1551         struct ipv6_pinfo *np = inet6_sk(sk);
1552         struct tcp_sock *tp;
1553         struct sk_buff *opt_skb = NULL;
1554
1555         /* Imagine: socket is IPv6. IPv4 packet arrives,
1556            goes to IPv4 receive handler and backlogged.
1557            From backlog it always goes here. Kerboom...
1558            Fortunately, tcp_rcv_established and rcv_established
1559            handle them correctly, but it is not case with
1560            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1561          */
1562
1563         if (skb->protocol == htons(ETH_P_IP))
1564                 return tcp_v4_do_rcv(sk, skb);
1565
1566 #ifdef CONFIG_TCP_MD5SIG
1567         if (tcp_v6_inbound_md5_hash (sk, skb))
1568                 goto discard;
1569 #endif
1570
1571         if (sk_filter(sk, skb))
1572                 goto discard;
1573
1574         /*
1575          *      socket locking is here for SMP purposes as backlog rcv
1576          *      is currently called with bh processing disabled.
1577          */
1578
1579         /* Do Stevens' IPV6_PKTOPTIONS.
1580
1581            Yes, guys, it is the only place in our code, where we
1582            may make it not affecting IPv4.
1583            The rest of code is protocol independent,
1584            and I do not like idea to uglify IPv4.
1585
1586            Actually, all the idea behind IPV6_PKTOPTIONS
1587            looks not very well thought. For now we latch
1588            options, received in the last packet, enqueued
1589            by tcp. Feel free to propose better solution.
1590                                                --ANK (980728)
1591          */
1592         if (np->rxopt.all)
1593                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1594
1595         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1596                 TCP_CHECK_TIMER(sk);
1597                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1598                         goto reset;
1599                 TCP_CHECK_TIMER(sk);
1600                 if (opt_skb)
1601                         goto ipv6_pktoptions;
1602                 return 0;
1603         }
1604
1605         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1606                 goto csum_err;
1607
1608         if (sk->sk_state == TCP_LISTEN) {
1609                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1610                 if (!nsk)
1611                         goto discard;
1612
1613                 /*
1614                  * Queue it on the new socket if the new socket is active,
1615                  * otherwise we just shortcircuit this and continue with
1616                  * the new socket..
1617                  */
1618                 if(nsk != sk) {
1619                         if (tcp_child_process(sk, nsk, skb))
1620                                 goto reset;
1621                         if (opt_skb)
1622                                 __kfree_skb(opt_skb);
1623                         return 0;
1624                 }
1625         }
1626
1627         TCP_CHECK_TIMER(sk);
1628         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1629                 goto reset;
1630         TCP_CHECK_TIMER(sk);
1631         if (opt_skb)
1632                 goto ipv6_pktoptions;
1633         return 0;
1634
1635 reset:
1636         tcp_v6_send_reset(sk, skb);
1637 discard:
1638         if (opt_skb)
1639                 __kfree_skb(opt_skb);
1640         kfree_skb(skb);
1641         return 0;
1642 csum_err:
1643         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1644         goto discard;
1645
1646
1647 ipv6_pktoptions:
1648         /* Do you ask, what is it?
1649
1650            1. skb was enqueued by tcp.
1651            2. skb is added to tail of read queue, rather than out of order.
1652            3. socket is not in passive state.
1653            4. Finally, it really contains options, which user wants to receive.
1654          */
1655         tp = tcp_sk(sk);
1656         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1657             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1658                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1659                         np->mcast_oif = inet6_iif(opt_skb);
1660                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1661                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1662                 if (ipv6_opt_accepted(sk, opt_skb)) {
1663                         skb_set_owner_r(opt_skb, sk);
1664                         opt_skb = xchg(&np->pktoptions, opt_skb);
1665                 } else {
1666                         __kfree_skb(opt_skb);
1667                         opt_skb = xchg(&np->pktoptions, NULL);
1668                 }
1669         }
1670
1671         kfree_skb(opt_skb);
1672         return 0;
1673 }
1674
1675 static int tcp_v6_rcv(struct sk_buff *skb)
1676 {
1677         struct tcphdr *th;
1678         struct sock *sk;
1679         int ret;
1680         struct net *net = dev_net(skb->dev);
1681
1682         if (skb->pkt_type != PACKET_HOST)
1683                 goto discard_it;
1684
1685         /*
1686          *      Count it even if it's bad.
1687          */
1688         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1689
1690         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1691                 goto discard_it;
1692
1693         th = tcp_hdr(skb);
1694
1695         if (th->doff < sizeof(struct tcphdr)/4)
1696                 goto bad_packet;
1697         if (!pskb_may_pull(skb, th->doff*4))
1698                 goto discard_it;
1699
1700         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1701                 goto bad_packet;
1702
1703         th = tcp_hdr(skb);
1704         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1705         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1706                                     skb->len - th->doff*4);
1707         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1708         TCP_SKB_CB(skb)->when = 0;
1709         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1710         TCP_SKB_CB(skb)->sacked = 0;
1711
1712         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1713         if (!sk)
1714                 goto no_tcp_socket;
1715
1716 process:
1717         if (sk->sk_state == TCP_TIME_WAIT)
1718                 goto do_time_wait;
1719
1720         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1721                 goto discard_and_relse;
1722
1723         if (sk_filter(sk, skb))
1724                 goto discard_and_relse;
1725
1726         skb->dev = NULL;
1727
1728         bh_lock_sock_nested(sk);
1729         ret = 0;
1730         if (!sock_owned_by_user(sk)) {
1731 #ifdef CONFIG_NET_DMA
1732                 struct tcp_sock *tp = tcp_sk(sk);
1733                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1734                         tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1735                 if (tp->ucopy.dma_chan)
1736                         ret = tcp_v6_do_rcv(sk, skb);
1737                 else
1738 #endif
1739                 {
1740                         if (!tcp_prequeue(sk, skb))
1741                                 ret = tcp_v6_do_rcv(sk, skb);
1742                 }
1743         } else
1744                 sk_add_backlog(sk, skb);
1745         bh_unlock_sock(sk);
1746
1747         sock_put(sk);
1748         return ret ? -1 : 0;
1749
1750 no_tcp_socket:
1751         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1752                 goto discard_it;
1753
1754         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1755 bad_packet:
1756                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1757         } else {
1758                 tcp_v6_send_reset(NULL, skb);
1759         }
1760
1761 discard_it:
1762
1763         /*
1764          *      Discard frame
1765          */
1766
1767         kfree_skb(skb);
1768         return 0;
1769
1770 discard_and_relse:
1771         sock_put(sk);
1772         goto discard_it;
1773
1774 do_time_wait:
1775         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1776                 inet_twsk_put(inet_twsk(sk));
1777                 goto discard_it;
1778         }
1779
1780         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1781                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1782                 inet_twsk_put(inet_twsk(sk));
1783                 goto discard_it;
1784         }
1785
1786         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1787         case TCP_TW_SYN:
1788         {
1789                 struct sock *sk2;
1790
1791                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1792                                             &ipv6_hdr(skb)->daddr,
1793                                             ntohs(th->dest), inet6_iif(skb));
1794                 if (sk2 != NULL) {
1795                         struct inet_timewait_sock *tw = inet_twsk(sk);
1796                         inet_twsk_deschedule(tw, &tcp_death_row);
1797                         inet_twsk_put(tw);
1798                         sk = sk2;
1799                         goto process;
1800                 }
1801                 /* Fall through to ACK */
1802         }
1803         case TCP_TW_ACK:
1804                 tcp_v6_timewait_ack(sk, skb);
1805                 break;
1806         case TCP_TW_RST:
1807                 goto no_tcp_socket;
1808         case TCP_TW_SUCCESS:;
1809         }
1810         goto discard_it;
1811 }
1812
1813 static int tcp_v6_remember_stamp(struct sock *sk)
1814 {
1815         /* Alas, not yet... */
1816         return 0;
1817 }
1818
1819 static const struct inet_connection_sock_af_ops ipv6_specific = {
1820         .queue_xmit        = inet6_csk_xmit,
1821         .send_check        = tcp_v6_send_check,
1822         .rebuild_header    = inet6_sk_rebuild_header,
1823         .conn_request      = tcp_v6_conn_request,
1824         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1825         .remember_stamp    = tcp_v6_remember_stamp,
1826         .net_header_len    = sizeof(struct ipv6hdr),
1827         .setsockopt        = ipv6_setsockopt,
1828         .getsockopt        = ipv6_getsockopt,
1829         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1830         .sockaddr_len      = sizeof(struct sockaddr_in6),
1831         .bind_conflict     = inet6_csk_bind_conflict,
1832 #ifdef CONFIG_COMPAT
1833         .compat_setsockopt = compat_ipv6_setsockopt,
1834         .compat_getsockopt = compat_ipv6_getsockopt,
1835 #endif
1836 };
1837
1838 #ifdef CONFIG_TCP_MD5SIG
1839 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1840         .md5_lookup     =       tcp_v6_md5_lookup,
1841         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1842         .md5_add        =       tcp_v6_md5_add_func,
1843         .md5_parse      =       tcp_v6_parse_md5_keys,
1844 };
1845 #endif
1846
1847 /*
1848  *      TCP over IPv4 via INET6 API
1849  */
1850
1851 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1852         .queue_xmit        = ip_queue_xmit,
1853         .send_check        = tcp_v4_send_check,
1854         .rebuild_header    = inet_sk_rebuild_header,
1855         .conn_request      = tcp_v6_conn_request,
1856         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1857         .remember_stamp    = tcp_v4_remember_stamp,
1858         .net_header_len    = sizeof(struct iphdr),
1859         .setsockopt        = ipv6_setsockopt,
1860         .getsockopt        = ipv6_getsockopt,
1861         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1862         .sockaddr_len      = sizeof(struct sockaddr_in6),
1863         .bind_conflict     = inet6_csk_bind_conflict,
1864 #ifdef CONFIG_COMPAT
1865         .compat_setsockopt = compat_ipv6_setsockopt,
1866         .compat_getsockopt = compat_ipv6_getsockopt,
1867 #endif
1868 };
1869
1870 #ifdef CONFIG_TCP_MD5SIG
1871 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1872         .md5_lookup     =       tcp_v4_md5_lookup,
1873         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1874         .md5_add        =       tcp_v6_md5_add_func,
1875         .md5_parse      =       tcp_v6_parse_md5_keys,
1876 };
1877 #endif
1878
1879 /* NOTE: A lot of things set to zero explicitly by call to
1880  *       sk_alloc() so need not be done here.
1881  */
1882 static int tcp_v6_init_sock(struct sock *sk)
1883 {
1884         struct inet_connection_sock *icsk = inet_csk(sk);
1885         struct tcp_sock *tp = tcp_sk(sk);
1886
1887         skb_queue_head_init(&tp->out_of_order_queue);
1888         tcp_init_xmit_timers(sk);
1889         tcp_prequeue_init(tp);
1890
1891         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1892         tp->mdev = TCP_TIMEOUT_INIT;
1893
1894         /* So many TCP implementations out there (incorrectly) count the
1895          * initial SYN frame in their delayed-ACK and congestion control
1896          * algorithms that we must have the following bandaid to talk
1897          * efficiently to them.  -DaveM
1898          */
1899         tp->snd_cwnd = 2;
1900
1901         /* See draft-stevens-tcpca-spec-01 for discussion of the
1902          * initialization of these values.
1903          */
1904         tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1905         tp->snd_cwnd_clamp = ~0;
1906         tp->mss_cache = TCP_MSS_DEFAULT;
1907
1908         tp->reordering = sysctl_tcp_reordering;
1909
1910         sk->sk_state = TCP_CLOSE;
1911
1912         icsk->icsk_af_ops = &ipv6_specific;
1913         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1914         icsk->icsk_sync_mss = tcp_sync_mss;
1915         sk->sk_write_space = sk_stream_write_space;
1916         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1917
1918 #ifdef CONFIG_TCP_MD5SIG
1919         tp->af_specific = &tcp_sock_ipv6_specific;
1920 #endif
1921
1922         /* TCP Cookie Transactions */
1923         if (sysctl_tcp_cookie_size > 0) {
1924                 /* Default, cookies without s_data_payload. */
1925                 tp->cookie_values =
1926                         kzalloc(sizeof(*tp->cookie_values),
1927                                 sk->sk_allocation);
1928                 if (tp->cookie_values != NULL)
1929                         kref_init(&tp->cookie_values->kref);
1930         }
1931         /* Presumed zeroed, in order of appearance:
1932          *      cookie_in_always, cookie_out_never,
1933          *      s_data_constant, s_data_in, s_data_out
1934          */
1935         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1936         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1937
1938         local_bh_disable();
1939         percpu_counter_inc(&tcp_sockets_allocated);
1940         local_bh_enable();
1941
1942         return 0;
1943 }
1944
1945 static void tcp_v6_destroy_sock(struct sock *sk)
1946 {
1947 #ifdef CONFIG_TCP_MD5SIG
1948         /* Clean up the MD5 key list */
1949         if (tcp_sk(sk)->md5sig_info)
1950                 tcp_v6_clear_md5_list(sk);
1951 #endif
1952         tcp_v4_destroy_sock(sk);
1953         inet6_destroy_sock(sk);
1954 }
1955
1956 #ifdef CONFIG_PROC_FS
1957 /* Proc filesystem TCPv6 sock list dumping. */
1958 static void get_openreq6(struct seq_file *seq,
1959                          struct sock *sk, struct request_sock *req, int i, int uid)
1960 {
1961         int ttd = req->expires - jiffies;
1962         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1963         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1964
1965         if (ttd < 0)
1966                 ttd = 0;
1967
1968         seq_printf(seq,
1969                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1970                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1971                    i,
1972                    src->s6_addr32[0], src->s6_addr32[1],
1973                    src->s6_addr32[2], src->s6_addr32[3],
1974                    ntohs(inet_rsk(req)->loc_port),
1975                    dest->s6_addr32[0], dest->s6_addr32[1],
1976                    dest->s6_addr32[2], dest->s6_addr32[3],
1977                    ntohs(inet_rsk(req)->rmt_port),
1978                    TCP_SYN_RECV,
1979                    0,0, /* could print option size, but that is af dependent. */
1980                    1,   /* timers active (only the expire timer) */
1981                    jiffies_to_clock_t(ttd),
1982                    req->retrans,
1983                    uid,
1984                    0,  /* non standard timer */
1985                    0, /* open_requests have no inode */
1986                    0, req);
1987 }
1988
1989 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1990 {
1991         struct in6_addr *dest, *src;
1992         __u16 destp, srcp;
1993         int timer_active;
1994         unsigned long timer_expires;
1995         struct inet_sock *inet = inet_sk(sp);
1996         struct tcp_sock *tp = tcp_sk(sp);
1997         const struct inet_connection_sock *icsk = inet_csk(sp);
1998         struct ipv6_pinfo *np = inet6_sk(sp);
1999
2000         dest  = &np->daddr;
2001         src   = &np->rcv_saddr;
2002         destp = ntohs(inet->inet_dport);
2003         srcp  = ntohs(inet->inet_sport);
2004
2005         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2006                 timer_active    = 1;
2007                 timer_expires   = icsk->icsk_timeout;
2008         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2009                 timer_active    = 4;
2010                 timer_expires   = icsk->icsk_timeout;
2011         } else if (timer_pending(&sp->sk_timer)) {
2012                 timer_active    = 2;
2013                 timer_expires   = sp->sk_timer.expires;
2014         } else {
2015                 timer_active    = 0;
2016                 timer_expires = jiffies;
2017         }
2018
2019         seq_printf(seq,
2020                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2021                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %lu %lu %u %u %d\n",
2022                    i,
2023                    src->s6_addr32[0], src->s6_addr32[1],
2024                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2025                    dest->s6_addr32[0], dest->s6_addr32[1],
2026                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2027                    sp->sk_state,
2028                    tp->write_seq-tp->snd_una,
2029                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2030                    timer_active,
2031                    jiffies_to_clock_t(timer_expires - jiffies),
2032                    icsk->icsk_retransmits,
2033                    sock_i_uid(sp),
2034                    icsk->icsk_probes_out,
2035                    sock_i_ino(sp),
2036                    atomic_read(&sp->sk_refcnt), sp,
2037                    jiffies_to_clock_t(icsk->icsk_rto),
2038                    jiffies_to_clock_t(icsk->icsk_ack.ato),
2039                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2040                    tp->snd_cwnd,
2041                    tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
2042                    );
2043 }
2044
2045 static void get_timewait6_sock(struct seq_file *seq,
2046                                struct inet_timewait_sock *tw, int i)
2047 {
2048         struct in6_addr *dest, *src;
2049         __u16 destp, srcp;
2050         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2051         int ttd = tw->tw_ttd - jiffies;
2052
2053         if (ttd < 0)
2054                 ttd = 0;
2055
2056         dest = &tw6->tw_v6_daddr;
2057         src  = &tw6->tw_v6_rcv_saddr;
2058         destp = ntohs(tw->tw_dport);
2059         srcp  = ntohs(tw->tw_sport);
2060
2061         seq_printf(seq,
2062                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2063                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2064                    i,
2065                    src->s6_addr32[0], src->s6_addr32[1],
2066                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2067                    dest->s6_addr32[0], dest->s6_addr32[1],
2068                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2069                    tw->tw_substate, 0, 0,
2070                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2071                    atomic_read(&tw->tw_refcnt), tw);
2072 }
2073
2074 static int tcp6_seq_show(struct seq_file *seq, void *v)
2075 {
2076         struct tcp_iter_state *st;
2077
2078         if (v == SEQ_START_TOKEN) {
2079                 seq_puts(seq,
2080                          "  sl  "
2081                          "local_address                         "
2082                          "remote_address                        "
2083                          "st tx_queue rx_queue tr tm->when retrnsmt"
2084                          "   uid  timeout inode\n");
2085                 goto out;
2086         }
2087         st = seq->private;
2088
2089         switch (st->state) {
2090         case TCP_SEQ_STATE_LISTENING:
2091         case TCP_SEQ_STATE_ESTABLISHED:
2092                 get_tcp6_sock(seq, v, st->num);
2093                 break;
2094         case TCP_SEQ_STATE_OPENREQ:
2095                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2096                 break;
2097         case TCP_SEQ_STATE_TIME_WAIT:
2098                 get_timewait6_sock(seq, v, st->num);
2099                 break;
2100         }
2101 out:
2102         return 0;
2103 }
2104
2105 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2106         .name           = "tcp6",
2107         .family         = AF_INET6,
2108         .seq_fops       = {
2109                 .owner          = THIS_MODULE,
2110         },
2111         .seq_ops        = {
2112                 .show           = tcp6_seq_show,
2113         },
2114 };
2115
2116 int tcp6_proc_init(struct net *net)
2117 {
2118         return tcp_proc_register(net, &tcp6_seq_afinfo);
2119 }
2120
2121 void tcp6_proc_exit(struct net *net)
2122 {
2123         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2124 }
2125 #endif
2126
2127 struct proto tcpv6_prot = {
2128         .name                   = "TCPv6",
2129         .owner                  = THIS_MODULE,
2130         .close                  = tcp_close,
2131         .connect                = tcp_v6_connect,
2132         .disconnect             = tcp_disconnect,
2133         .accept                 = inet_csk_accept,
2134         .ioctl                  = tcp_ioctl,
2135         .init                   = tcp_v6_init_sock,
2136         .destroy                = tcp_v6_destroy_sock,
2137         .shutdown               = tcp_shutdown,
2138         .setsockopt             = tcp_setsockopt,
2139         .getsockopt             = tcp_getsockopt,
2140         .recvmsg                = tcp_recvmsg,
2141         .backlog_rcv            = tcp_v6_do_rcv,
2142         .hash                   = tcp_v6_hash,
2143         .unhash                 = inet_unhash,
2144         .get_port               = inet_csk_get_port,
2145         .enter_memory_pressure  = tcp_enter_memory_pressure,
2146         .sockets_allocated      = &tcp_sockets_allocated,
2147         .memory_allocated       = &tcp_memory_allocated,
2148         .memory_pressure        = &tcp_memory_pressure,
2149         .orphan_count           = &tcp_orphan_count,
2150         .sysctl_mem             = sysctl_tcp_mem,
2151         .sysctl_wmem            = sysctl_tcp_wmem,
2152         .sysctl_rmem            = sysctl_tcp_rmem,
2153         .max_header             = MAX_TCP_HEADER,
2154         .obj_size               = sizeof(struct tcp6_sock),
2155         .slab_flags             = SLAB_DESTROY_BY_RCU,
2156         .twsk_prot              = &tcp6_timewait_sock_ops,
2157         .rsk_prot               = &tcp6_request_sock_ops,
2158         .h.hashinfo             = &tcp_hashinfo,
2159 #ifdef CONFIG_COMPAT
2160         .compat_setsockopt      = compat_tcp_setsockopt,
2161         .compat_getsockopt      = compat_tcp_getsockopt,
2162 #endif
2163 };
2164
2165 static const struct inet6_protocol tcpv6_protocol = {
2166         .handler        =       tcp_v6_rcv,
2167         .err_handler    =       tcp_v6_err,
2168         .gso_send_check =       tcp_v6_gso_send_check,
2169         .gso_segment    =       tcp_tso_segment,
2170         .gro_receive    =       tcp6_gro_receive,
2171         .gro_complete   =       tcp6_gro_complete,
2172         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2173 };
2174
2175 static struct inet_protosw tcpv6_protosw = {
2176         .type           =       SOCK_STREAM,
2177         .protocol       =       IPPROTO_TCP,
2178         .prot           =       &tcpv6_prot,
2179         .ops            =       &inet6_stream_ops,
2180         .no_check       =       0,
2181         .flags          =       INET_PROTOSW_PERMANENT |
2182                                 INET_PROTOSW_ICSK,
2183 };
2184
2185 static int tcpv6_net_init(struct net *net)
2186 {
2187         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2188                                     SOCK_RAW, IPPROTO_TCP, net);
2189 }
2190
2191 static void tcpv6_net_exit(struct net *net)
2192 {
2193         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2194 }
2195
2196 static void tcpv6_net_exit_batch(struct list_head *net_exit_list)
2197 {
2198         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2199 }
2200
2201 static struct pernet_operations tcpv6_net_ops = {
2202         .init       = tcpv6_net_init,
2203         .exit       = tcpv6_net_exit,
2204         .exit_batch = tcpv6_net_exit_batch,
2205 };
2206
2207 int __init tcpv6_init(void)
2208 {
2209         int ret;
2210
2211         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2212         if (ret)
2213                 goto out;
2214
2215         /* register inet6 protocol */
2216         ret = inet6_register_protosw(&tcpv6_protosw);
2217         if (ret)
2218                 goto out_tcpv6_protocol;
2219
2220         ret = register_pernet_subsys(&tcpv6_net_ops);
2221         if (ret)
2222                 goto out_tcpv6_protosw;
2223 out:
2224         return ret;
2225
2226 out_tcpv6_protocol:
2227         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2228 out_tcpv6_protosw:
2229         inet6_unregister_protosw(&tcpv6_protosw);
2230         goto out;
2231 }
2232
2233 void tcpv6_exit(void)
2234 {
2235         unregister_pernet_subsys(&tcpv6_net_ops);
2236         inet6_unregister_protosw(&tcpv6_protosw);
2237         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2238 }