b429dfdd69dce9405d9eae23c9ef560f09c25751
[linux-2.6.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 #include <linux/slab.h>
42
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46
47 #include <net/tcp.h>
48 #include <net/ndisc.h>
49 #include <net/inet6_hashtables.h>
50 #include <net/inet6_connection_sock.h>
51 #include <net/ipv6.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/ip6_checksum.h>
56 #include <net/inet_ecn.h>
57 #include <net/protocol.h>
58 #include <net/xfrm.h>
59 #include <net/snmp.h>
60 #include <net/dsfield.h>
61 #include <net/timewait_sock.h>
62 #include <net/netdma.h>
63 #include <net/inet_common.h>
64
65 #include <asm/uaccess.h>
66
67 #include <linux/proc_fs.h>
68 #include <linux/seq_file.h>
69
70 #include <linux/crypto.h>
71 #include <linux/scatterlist.h>
72
73 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
74 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
75                                       struct request_sock *req);
76
77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
78 static void     __tcp_v6_send_check(struct sk_buff *skb,
79                                     struct in6_addr *saddr,
80                                     struct in6_addr *daddr);
81
82 static const struct inet_connection_sock_af_ops ipv6_mapped;
83 static const struct inet_connection_sock_af_ops ipv6_specific;
84 #ifdef CONFIG_TCP_MD5SIG
85 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
86 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
87 #else
88 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
89                                                    struct in6_addr *addr)
90 {
91         return NULL;
92 }
93 #endif
94
95 static void tcp_v6_hash(struct sock *sk)
96 {
97         if (sk->sk_state != TCP_CLOSE) {
98                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
99                         tcp_prot.hash(sk);
100                         return;
101                 }
102                 local_bh_disable();
103                 __inet6_hash(sk, NULL);
104                 local_bh_enable();
105         }
106 }
107
108 static __inline__ __sum16 tcp_v6_check(int len,
109                                    struct in6_addr *saddr,
110                                    struct in6_addr *daddr,
111                                    __wsum base)
112 {
113         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
114 }
115
116 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
117 {
118         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
119                                             ipv6_hdr(skb)->saddr.s6_addr32,
120                                             tcp_hdr(skb)->dest,
121                                             tcp_hdr(skb)->source);
122 }
123
124 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
125                           int addr_len)
126 {
127         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
128         struct inet_sock *inet = inet_sk(sk);
129         struct inet_connection_sock *icsk = inet_csk(sk);
130         struct ipv6_pinfo *np = inet6_sk(sk);
131         struct tcp_sock *tp = tcp_sk(sk);
132         struct in6_addr *saddr = NULL, *final_p = NULL, final;
133         struct flowi fl;
134         struct dst_entry *dst;
135         int addr_type;
136         int err;
137
138         if (addr_len < SIN6_LEN_RFC2133)
139                 return -EINVAL;
140
141         if (usin->sin6_family != AF_INET6)
142                 return(-EAFNOSUPPORT);
143
144         memset(&fl, 0, sizeof(fl));
145
146         if (np->sndflow) {
147                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
148                 IP6_ECN_flow_init(fl.fl6_flowlabel);
149                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
150                         struct ip6_flowlabel *flowlabel;
151                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
152                         if (flowlabel == NULL)
153                                 return -EINVAL;
154                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
155                         fl6_sock_release(flowlabel);
156                 }
157         }
158
159         /*
160          *      connect() to INADDR_ANY means loopback (BSD'ism).
161          */
162
163         if(ipv6_addr_any(&usin->sin6_addr))
164                 usin->sin6_addr.s6_addr[15] = 0x1;
165
166         addr_type = ipv6_addr_type(&usin->sin6_addr);
167
168         if(addr_type & IPV6_ADDR_MULTICAST)
169                 return -ENETUNREACH;
170
171         if (addr_type&IPV6_ADDR_LINKLOCAL) {
172                 if (addr_len >= sizeof(struct sockaddr_in6) &&
173                     usin->sin6_scope_id) {
174                         /* If interface is set while binding, indices
175                          * must coincide.
176                          */
177                         if (sk->sk_bound_dev_if &&
178                             sk->sk_bound_dev_if != usin->sin6_scope_id)
179                                 return -EINVAL;
180
181                         sk->sk_bound_dev_if = usin->sin6_scope_id;
182                 }
183
184                 /* Connect to link-local address requires an interface */
185                 if (!sk->sk_bound_dev_if)
186                         return -EINVAL;
187         }
188
189         if (tp->rx_opt.ts_recent_stamp &&
190             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
191                 tp->rx_opt.ts_recent = 0;
192                 tp->rx_opt.ts_recent_stamp = 0;
193                 tp->write_seq = 0;
194         }
195
196         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
197         np->flow_label = fl.fl6_flowlabel;
198
199         /*
200          *      TCP over IPv4
201          */
202
203         if (addr_type == IPV6_ADDR_MAPPED) {
204                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
205                 struct sockaddr_in sin;
206
207                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
208
209                 if (__ipv6_only_sock(sk))
210                         return -ENETUNREACH;
211
212                 sin.sin_family = AF_INET;
213                 sin.sin_port = usin->sin6_port;
214                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
215
216                 icsk->icsk_af_ops = &ipv6_mapped;
217                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
218 #ifdef CONFIG_TCP_MD5SIG
219                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
220 #endif
221
222                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
223
224                 if (err) {
225                         icsk->icsk_ext_hdr_len = exthdrlen;
226                         icsk->icsk_af_ops = &ipv6_specific;
227                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
228 #ifdef CONFIG_TCP_MD5SIG
229                         tp->af_specific = &tcp_sock_ipv6_specific;
230 #endif
231                         goto failure;
232                 } else {
233                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
234                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
235                                                &np->rcv_saddr);
236                 }
237
238                 return err;
239         }
240
241         if (!ipv6_addr_any(&np->rcv_saddr))
242                 saddr = &np->rcv_saddr;
243
244         fl.proto = IPPROTO_TCP;
245         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
246         ipv6_addr_copy(&fl.fl6_src,
247                        (saddr ? saddr : &np->saddr));
248         fl.oif = sk->sk_bound_dev_if;
249         fl.mark = sk->sk_mark;
250         fl.fl_ip_dport = usin->sin6_port;
251         fl.fl_ip_sport = inet->inet_sport;
252
253         if (np->opt && np->opt->srcrt) {
254                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
255                 ipv6_addr_copy(&final, &fl.fl6_dst);
256                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
257                 final_p = &final;
258         }
259
260         security_sk_classify_flow(sk, &fl);
261
262         err = ip6_dst_lookup(sk, &dst, &fl);
263         if (err)
264                 goto failure;
265         if (final_p)
266                 ipv6_addr_copy(&fl.fl6_dst, final_p);
267
268         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
269         if (err < 0) {
270                 if (err == -EREMOTE)
271                         err = ip6_dst_blackhole(sk, &dst, &fl);
272                 if (err < 0)
273                         goto failure;
274         }
275
276         if (saddr == NULL) {
277                 saddr = &fl.fl6_src;
278                 ipv6_addr_copy(&np->rcv_saddr, saddr);
279         }
280
281         /* set the source address */
282         ipv6_addr_copy(&np->saddr, saddr);
283         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
284
285         sk->sk_gso_type = SKB_GSO_TCPV6;
286         __ip6_dst_store(sk, dst, NULL, NULL);
287
288         icsk->icsk_ext_hdr_len = 0;
289         if (np->opt)
290                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
291                                           np->opt->opt_nflen);
292
293         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
294
295         inet->inet_dport = usin->sin6_port;
296
297         tcp_set_state(sk, TCP_SYN_SENT);
298         err = inet6_hash_connect(&tcp_death_row, sk);
299         if (err)
300                 goto late_failure;
301
302         if (!tp->write_seq)
303                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
304                                                              np->daddr.s6_addr32,
305                                                              inet->inet_sport,
306                                                              inet->inet_dport);
307
308         err = tcp_connect(sk);
309         if (err)
310                 goto late_failure;
311
312         return 0;
313
314 late_failure:
315         tcp_set_state(sk, TCP_CLOSE);
316         __sk_dst_reset(sk);
317 failure:
318         inet->inet_dport = 0;
319         sk->sk_route_caps = 0;
320         return err;
321 }
322
323 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
324                 u8 type, u8 code, int offset, __be32 info)
325 {
326         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
327         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
328         struct ipv6_pinfo *np;
329         struct sock *sk;
330         int err;
331         struct tcp_sock *tp;
332         __u32 seq;
333         struct net *net = dev_net(skb->dev);
334
335         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
336                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
337
338         if (sk == NULL) {
339                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
340                                    ICMP6_MIB_INERRORS);
341                 return;
342         }
343
344         if (sk->sk_state == TCP_TIME_WAIT) {
345                 inet_twsk_put(inet_twsk(sk));
346                 return;
347         }
348
349         bh_lock_sock(sk);
350         if (sock_owned_by_user(sk))
351                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
352
353         if (sk->sk_state == TCP_CLOSE)
354                 goto out;
355
356         tp = tcp_sk(sk);
357         seq = ntohl(th->seq);
358         if (sk->sk_state != TCP_LISTEN &&
359             !between(seq, tp->snd_una, tp->snd_nxt)) {
360                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
361                 goto out;
362         }
363
364         np = inet6_sk(sk);
365
366         if (type == ICMPV6_PKT_TOOBIG) {
367                 struct dst_entry *dst = NULL;
368
369                 if (sock_owned_by_user(sk))
370                         goto out;
371                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
372                         goto out;
373
374                 /* icmp should have updated the destination cache entry */
375                 dst = __sk_dst_check(sk, np->dst_cookie);
376
377                 if (dst == NULL) {
378                         struct inet_sock *inet = inet_sk(sk);
379                         struct flowi fl;
380
381                         /* BUGGG_FUTURE: Again, it is not clear how
382                            to handle rthdr case. Ignore this complexity
383                            for now.
384                          */
385                         memset(&fl, 0, sizeof(fl));
386                         fl.proto = IPPROTO_TCP;
387                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
388                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
389                         fl.oif = sk->sk_bound_dev_if;
390                         fl.mark = sk->sk_mark;
391                         fl.fl_ip_dport = inet->inet_dport;
392                         fl.fl_ip_sport = inet->inet_sport;
393                         security_skb_classify_flow(skb, &fl);
394
395                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
396                                 sk->sk_err_soft = -err;
397                                 goto out;
398                         }
399
400                         if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) {
401                                 sk->sk_err_soft = -err;
402                                 goto out;
403                         }
404
405                 } else
406                         dst_hold(dst);
407
408                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
409                         tcp_sync_mss(sk, dst_mtu(dst));
410                         tcp_simple_retransmit(sk);
411                 } /* else let the usual retransmit timer handle it */
412                 dst_release(dst);
413                 goto out;
414         }
415
416         icmpv6_err_convert(type, code, &err);
417
418         /* Might be for an request_sock */
419         switch (sk->sk_state) {
420                 struct request_sock *req, **prev;
421         case TCP_LISTEN:
422                 if (sock_owned_by_user(sk))
423                         goto out;
424
425                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
426                                            &hdr->saddr, inet6_iif(skb));
427                 if (!req)
428                         goto out;
429
430                 /* ICMPs are not backlogged, hence we cannot get
431                  * an established socket here.
432                  */
433                 WARN_ON(req->sk != NULL);
434
435                 if (seq != tcp_rsk(req)->snt_isn) {
436                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
437                         goto out;
438                 }
439
440                 inet_csk_reqsk_queue_drop(sk, req, prev);
441                 goto out;
442
443         case TCP_SYN_SENT:
444         case TCP_SYN_RECV:  /* Cannot happen.
445                                It can, it SYNs are crossed. --ANK */
446                 if (!sock_owned_by_user(sk)) {
447                         sk->sk_err = err;
448                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
449
450                         tcp_done(sk);
451                 } else
452                         sk->sk_err_soft = err;
453                 goto out;
454         }
455
456         if (!sock_owned_by_user(sk) && np->recverr) {
457                 sk->sk_err = err;
458                 sk->sk_error_report(sk);
459         } else
460                 sk->sk_err_soft = err;
461
462 out:
463         bh_unlock_sock(sk);
464         sock_put(sk);
465 }
466
467
468 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
469                               struct request_values *rvp)
470 {
471         struct inet6_request_sock *treq = inet6_rsk(req);
472         struct ipv6_pinfo *np = inet6_sk(sk);
473         struct sk_buff * skb;
474         struct ipv6_txoptions *opt = NULL;
475         struct in6_addr * final_p = NULL, final;
476         struct flowi fl;
477         struct dst_entry *dst;
478         int err = -1;
479
480         memset(&fl, 0, sizeof(fl));
481         fl.proto = IPPROTO_TCP;
482         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
483         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
484         fl.fl6_flowlabel = 0;
485         fl.oif = treq->iif;
486         fl.mark = sk->sk_mark;
487         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
488         fl.fl_ip_sport = inet_rsk(req)->loc_port;
489         security_req_classify_flow(req, &fl);
490
491         opt = np->opt;
492         if (opt && opt->srcrt) {
493                 struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
494                 ipv6_addr_copy(&final, &fl.fl6_dst);
495                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
496                 final_p = &final;
497         }
498
499         err = ip6_dst_lookup(sk, &dst, &fl);
500         if (err)
501                 goto done;
502         if (final_p)
503                 ipv6_addr_copy(&fl.fl6_dst, final_p);
504         if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
505                 goto done;
506
507         skb = tcp_make_synack(sk, dst, req, rvp);
508         if (skb) {
509                 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
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 sk_buff *skb,
921                                 struct in6_addr *saddr, struct in6_addr *daddr)
922 {
923         struct tcphdr *th = tcp_hdr(skb);
924
925         if (skb->ip_summed == CHECKSUM_PARTIAL) {
926                 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
927                 skb->csum_start = skb_transport_header(skb) - skb->head;
928                 skb->csum_offset = offsetof(struct tcphdr, check);
929         } else {
930                 th->check = tcp_v6_check(skb->len, saddr, daddr,
931                                          csum_partial(th, th->doff << 2,
932                                                       skb->csum));
933         }
934 }
935
936 static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
937 {
938         struct ipv6_pinfo *np = inet6_sk(sk);
939
940         __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
941 }
942
943 static int tcp_v6_gso_send_check(struct sk_buff *skb)
944 {
945         struct ipv6hdr *ipv6h;
946         struct tcphdr *th;
947
948         if (!pskb_may_pull(skb, sizeof(*th)))
949                 return -EINVAL;
950
951         ipv6h = ipv6_hdr(skb);
952         th = tcp_hdr(skb);
953
954         th->check = 0;
955         skb->ip_summed = CHECKSUM_PARTIAL;
956         __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
957         return 0;
958 }
959
960 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
961                                          struct sk_buff *skb)
962 {
963         struct ipv6hdr *iph = skb_gro_network_header(skb);
964
965         switch (skb->ip_summed) {
966         case CHECKSUM_COMPLETE:
967                 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
968                                   skb->csum)) {
969                         skb->ip_summed = CHECKSUM_UNNECESSARY;
970                         break;
971                 }
972
973                 /* fall through */
974         case CHECKSUM_NONE:
975                 NAPI_GRO_CB(skb)->flush = 1;
976                 return NULL;
977         }
978
979         return tcp_gro_receive(head, skb);
980 }
981
982 static int tcp6_gro_complete(struct sk_buff *skb)
983 {
984         struct ipv6hdr *iph = ipv6_hdr(skb);
985         struct tcphdr *th = tcp_hdr(skb);
986
987         th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
988                                   &iph->saddr, &iph->daddr, 0);
989         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
990
991         return tcp_gro_complete(skb);
992 }
993
994 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
995                                  u32 ts, struct tcp_md5sig_key *key, int rst)
996 {
997         struct tcphdr *th = tcp_hdr(skb), *t1;
998         struct sk_buff *buff;
999         struct flowi fl;
1000         struct net *net = dev_net(skb_dst(skb)->dev);
1001         struct sock *ctl_sk = net->ipv6.tcp_sk;
1002         unsigned int tot_len = sizeof(struct tcphdr);
1003         struct dst_entry *dst;
1004         __be32 *topt;
1005
1006         if (ts)
1007                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1008 #ifdef CONFIG_TCP_MD5SIG
1009         if (key)
1010                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1011 #endif
1012
1013         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1014                          GFP_ATOMIC);
1015         if (buff == NULL)
1016                 return;
1017
1018         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1019
1020         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1021         skb_reset_transport_header(skb);
1022
1023         /* Swap the send and the receive. */
1024         memset(t1, 0, sizeof(*t1));
1025         t1->dest = th->source;
1026         t1->source = th->dest;
1027         t1->doff = tot_len / 4;
1028         t1->seq = htonl(seq);
1029         t1->ack_seq = htonl(ack);
1030         t1->ack = !rst || !th->ack;
1031         t1->rst = rst;
1032         t1->window = htons(win);
1033
1034         topt = (__be32 *)(t1 + 1);
1035
1036         if (ts) {
1037                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1038                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1039                 *topt++ = htonl(tcp_time_stamp);
1040                 *topt++ = htonl(ts);
1041         }
1042
1043 #ifdef CONFIG_TCP_MD5SIG
1044         if (key) {
1045                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1046                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1047                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1048                                     &ipv6_hdr(skb)->saddr,
1049                                     &ipv6_hdr(skb)->daddr, t1);
1050         }
1051 #endif
1052
1053         buff->csum = csum_partial(t1, tot_len, 0);
1054
1055         memset(&fl, 0, sizeof(fl));
1056         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1057         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1058
1059         __tcp_v6_send_check(buff, &fl.fl6_src, &fl.fl6_dst);
1060
1061         fl.proto = IPPROTO_TCP;
1062         fl.oif = inet6_iif(skb);
1063         fl.fl_ip_dport = t1->dest;
1064         fl.fl_ip_sport = t1->source;
1065         security_skb_classify_flow(skb, &fl);
1066
1067         /* Pass a socket to ip6_dst_lookup either it is for RST
1068          * Underlying function will use this to retrieve the network
1069          * namespace
1070          */
1071         if (!ip6_dst_lookup(ctl_sk, &dst, &fl)) {
1072                 if (xfrm_lookup(net, &dst, &fl, NULL, 0) >= 0) {
1073                         skb_dst_set(buff, dst);
1074                         ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1075                         TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1076                         if (rst)
1077                                 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1078                         return;
1079                 }
1080         }
1081
1082         kfree_skb(buff);
1083 }
1084
1085 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1086 {
1087         struct tcphdr *th = tcp_hdr(skb);
1088         u32 seq = 0, ack_seq = 0;
1089         struct tcp_md5sig_key *key = NULL;
1090
1091         if (th->rst)
1092                 return;
1093
1094         if (!ipv6_unicast_destination(skb))
1095                 return;
1096
1097 #ifdef CONFIG_TCP_MD5SIG
1098         if (sk)
1099                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1100 #endif
1101
1102         if (th->ack)
1103                 seq = ntohl(th->ack_seq);
1104         else
1105                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1106                           (th->doff << 2);
1107
1108         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1109 }
1110
1111 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1112                             struct tcp_md5sig_key *key)
1113 {
1114         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1115 }
1116
1117 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1118 {
1119         struct inet_timewait_sock *tw = inet_twsk(sk);
1120         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1121
1122         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1123                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1124                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1125
1126         inet_twsk_put(tw);
1127 }
1128
1129 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1130                                   struct request_sock *req)
1131 {
1132         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1133                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1134 }
1135
1136
1137 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1138 {
1139         struct request_sock *req, **prev;
1140         const struct tcphdr *th = tcp_hdr(skb);
1141         struct sock *nsk;
1142
1143         /* Find possible connection requests. */
1144         req = inet6_csk_search_req(sk, &prev, th->source,
1145                                    &ipv6_hdr(skb)->saddr,
1146                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1147         if (req)
1148                 return tcp_check_req(sk, skb, req, prev);
1149
1150         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1151                         &ipv6_hdr(skb)->saddr, th->source,
1152                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1153
1154         if (nsk) {
1155                 if (nsk->sk_state != TCP_TIME_WAIT) {
1156                         bh_lock_sock(nsk);
1157                         return nsk;
1158                 }
1159                 inet_twsk_put(inet_twsk(nsk));
1160                 return NULL;
1161         }
1162
1163 #ifdef CONFIG_SYN_COOKIES
1164         if (!th->rst && !th->syn && th->ack)
1165                 sk = cookie_v6_check(sk, skb);
1166 #endif
1167         return sk;
1168 }
1169
1170 /* FIXME: this is substantially similar to the ipv4 code.
1171  * Can some kind of merge be done? -- erics
1172  */
1173 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1174 {
1175         struct tcp_extend_values tmp_ext;
1176         struct tcp_options_received tmp_opt;
1177         u8 *hash_location;
1178         struct request_sock *req;
1179         struct inet6_request_sock *treq;
1180         struct ipv6_pinfo *np = inet6_sk(sk);
1181         struct tcp_sock *tp = tcp_sk(sk);
1182         __u32 isn = TCP_SKB_CB(skb)->when;
1183 #ifdef CONFIG_SYN_COOKIES
1184         int want_cookie = 0;
1185 #else
1186 #define want_cookie 0
1187 #endif
1188
1189         if (skb->protocol == htons(ETH_P_IP))
1190                 return tcp_v4_conn_request(sk, skb);
1191
1192         if (!ipv6_unicast_destination(skb))
1193                 goto drop;
1194
1195         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1196                 if (net_ratelimit())
1197                         syn_flood_warning(skb);
1198 #ifdef CONFIG_SYN_COOKIES
1199                 if (sysctl_tcp_syncookies)
1200                         want_cookie = 1;
1201                 else
1202 #endif
1203                 goto drop;
1204         }
1205
1206         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1207                 goto drop;
1208
1209         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1210         if (req == NULL)
1211                 goto drop;
1212
1213 #ifdef CONFIG_TCP_MD5SIG
1214         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1215 #endif
1216
1217         tcp_clear_options(&tmp_opt);
1218         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1219         tmp_opt.user_mss = tp->rx_opt.user_mss;
1220         tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1221
1222         if (tmp_opt.cookie_plus > 0 &&
1223             tmp_opt.saw_tstamp &&
1224             !tp->rx_opt.cookie_out_never &&
1225             (sysctl_tcp_cookie_size > 0 ||
1226              (tp->cookie_values != NULL &&
1227               tp->cookie_values->cookie_desired > 0))) {
1228                 u8 *c;
1229                 u32 *d;
1230                 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1231                 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1232
1233                 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1234                         goto drop_and_free;
1235
1236                 /* Secret recipe starts with IP addresses */
1237                 d = &ipv6_hdr(skb)->daddr.s6_addr32[0];
1238                 *mess++ ^= *d++;
1239                 *mess++ ^= *d++;
1240                 *mess++ ^= *d++;
1241                 *mess++ ^= *d++;
1242                 d = &ipv6_hdr(skb)->saddr.s6_addr32[0];
1243                 *mess++ ^= *d++;
1244                 *mess++ ^= *d++;
1245                 *mess++ ^= *d++;
1246                 *mess++ ^= *d++;
1247
1248                 /* plus variable length Initiator Cookie */
1249                 c = (u8 *)mess;
1250                 while (l-- > 0)
1251                         *c++ ^= *hash_location++;
1252
1253 #ifdef CONFIG_SYN_COOKIES
1254                 want_cookie = 0;        /* not our kind of cookie */
1255 #endif
1256                 tmp_ext.cookie_out_never = 0; /* false */
1257                 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1258         } else if (!tp->rx_opt.cookie_in_always) {
1259                 /* redundant indications, but ensure initialization. */
1260                 tmp_ext.cookie_out_never = 1; /* true */
1261                 tmp_ext.cookie_plus = 0;
1262         } else {
1263                 goto drop_and_free;
1264         }
1265         tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1266
1267         if (want_cookie && !tmp_opt.saw_tstamp)
1268                 tcp_clear_options(&tmp_opt);
1269
1270         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1271         tcp_openreq_init(req, &tmp_opt, skb);
1272
1273         treq = inet6_rsk(req);
1274         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1275         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1276         if (!want_cookie)
1277                 TCP_ECN_create_request(req, tcp_hdr(skb));
1278
1279         if (want_cookie) {
1280                 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1281                 req->cookie_ts = tmp_opt.tstamp_ok;
1282         } else if (!isn) {
1283                 if (ipv6_opt_accepted(sk, skb) ||
1284                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1285                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1286                         atomic_inc(&skb->users);
1287                         treq->pktopts = skb;
1288                 }
1289                 treq->iif = sk->sk_bound_dev_if;
1290
1291                 /* So that link locals have meaning */
1292                 if (!sk->sk_bound_dev_if &&
1293                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1294                         treq->iif = inet6_iif(skb);
1295
1296                 isn = tcp_v6_init_sequence(skb);
1297         }
1298         tcp_rsk(req)->snt_isn = isn;
1299
1300         security_inet_conn_request(sk, skb, req);
1301
1302         if (tcp_v6_send_synack(sk, req,
1303                                (struct request_values *)&tmp_ext) ||
1304             want_cookie)
1305                 goto drop_and_free;
1306
1307         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1308         return 0;
1309
1310 drop_and_free:
1311         reqsk_free(req);
1312 drop:
1313         return 0; /* don't send reset */
1314 }
1315
1316 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1317                                           struct request_sock *req,
1318                                           struct dst_entry *dst)
1319 {
1320         struct inet6_request_sock *treq;
1321         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1322         struct tcp6_sock *newtcp6sk;
1323         struct inet_sock *newinet;
1324         struct tcp_sock *newtp;
1325         struct sock *newsk;
1326         struct ipv6_txoptions *opt;
1327 #ifdef CONFIG_TCP_MD5SIG
1328         struct tcp_md5sig_key *key;
1329 #endif
1330
1331         if (skb->protocol == htons(ETH_P_IP)) {
1332                 /*
1333                  *      v6 mapped
1334                  */
1335
1336                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1337
1338                 if (newsk == NULL)
1339                         return NULL;
1340
1341                 newtcp6sk = (struct tcp6_sock *)newsk;
1342                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1343
1344                 newinet = inet_sk(newsk);
1345                 newnp = inet6_sk(newsk);
1346                 newtp = tcp_sk(newsk);
1347
1348                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1349
1350                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1351
1352                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1353
1354                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1355
1356                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1357                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1358 #ifdef CONFIG_TCP_MD5SIG
1359                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1360 #endif
1361
1362                 newnp->pktoptions  = NULL;
1363                 newnp->opt         = NULL;
1364                 newnp->mcast_oif   = inet6_iif(skb);
1365                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1366
1367                 /*
1368                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1369                  * here, tcp_create_openreq_child now does this for us, see the comment in
1370                  * that function for the gory details. -acme
1371                  */
1372
1373                 /* It is tricky place. Until this moment IPv4 tcp
1374                    worked with IPv6 icsk.icsk_af_ops.
1375                    Sync it now.
1376                  */
1377                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1378
1379                 return newsk;
1380         }
1381
1382         treq = inet6_rsk(req);
1383         opt = np->opt;
1384
1385         if (sk_acceptq_is_full(sk))
1386                 goto out_overflow;
1387
1388         if (dst == NULL) {
1389                 struct in6_addr *final_p = NULL, final;
1390                 struct flowi fl;
1391
1392                 memset(&fl, 0, sizeof(fl));
1393                 fl.proto = IPPROTO_TCP;
1394                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1395                 if (opt && opt->srcrt) {
1396                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1397                         ipv6_addr_copy(&final, &fl.fl6_dst);
1398                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1399                         final_p = &final;
1400                 }
1401                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1402                 fl.oif = sk->sk_bound_dev_if;
1403                 fl.mark = sk->sk_mark;
1404                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1405                 fl.fl_ip_sport = inet_rsk(req)->loc_port;
1406                 security_req_classify_flow(req, &fl);
1407
1408                 if (ip6_dst_lookup(sk, &dst, &fl))
1409                         goto out;
1410
1411                 if (final_p)
1412                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1413
1414                 if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
1415                         goto out;
1416         }
1417
1418         newsk = tcp_create_openreq_child(sk, req, skb);
1419         if (newsk == NULL)
1420                 goto out;
1421
1422         /*
1423          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1424          * count here, tcp_create_openreq_child now does this for us, see the
1425          * comment in that function for the gory details. -acme
1426          */
1427
1428         newsk->sk_gso_type = SKB_GSO_TCPV6;
1429         __ip6_dst_store(newsk, dst, NULL, NULL);
1430
1431         newtcp6sk = (struct tcp6_sock *)newsk;
1432         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1433
1434         newtp = tcp_sk(newsk);
1435         newinet = inet_sk(newsk);
1436         newnp = inet6_sk(newsk);
1437
1438         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1439
1440         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1441         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1442         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1443         newsk->sk_bound_dev_if = treq->iif;
1444
1445         /* Now IPv6 options...
1446
1447            First: no IPv4 options.
1448          */
1449         newinet->opt = NULL;
1450         newnp->ipv6_fl_list = NULL;
1451
1452         /* Clone RX bits */
1453         newnp->rxopt.all = np->rxopt.all;
1454
1455         /* Clone pktoptions received with SYN */
1456         newnp->pktoptions = NULL;
1457         if (treq->pktopts != NULL) {
1458                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1459                 kfree_skb(treq->pktopts);
1460                 treq->pktopts = NULL;
1461                 if (newnp->pktoptions)
1462                         skb_set_owner_r(newnp->pktoptions, newsk);
1463         }
1464         newnp->opt        = NULL;
1465         newnp->mcast_oif  = inet6_iif(skb);
1466         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1467
1468         /* Clone native IPv6 options from listening socket (if any)
1469
1470            Yes, keeping reference count would be much more clever,
1471            but we make one more one thing there: reattach optmem
1472            to newsk.
1473          */
1474         if (opt) {
1475                 newnp->opt = ipv6_dup_options(newsk, opt);
1476                 if (opt != np->opt)
1477                         sock_kfree_s(sk, opt, opt->tot_len);
1478         }
1479
1480         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1481         if (newnp->opt)
1482                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1483                                                      newnp->opt->opt_flen);
1484
1485         tcp_mtup_init(newsk);
1486         tcp_sync_mss(newsk, dst_mtu(dst));
1487         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1488         tcp_initialize_rcv_mss(newsk);
1489
1490         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1491         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1492
1493 #ifdef CONFIG_TCP_MD5SIG
1494         /* Copy over the MD5 key from the original socket */
1495         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1496                 /* We're using one, so create a matching key
1497                  * on the newsk structure. If we fail to get
1498                  * memory, then we end up not copying the key
1499                  * across. Shucks.
1500                  */
1501                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1502                 if (newkey != NULL)
1503                         tcp_v6_md5_do_add(newsk, &newnp->daddr,
1504                                           newkey, key->keylen);
1505         }
1506 #endif
1507
1508         __inet6_hash(newsk, NULL);
1509         __inet_inherit_port(sk, newsk);
1510
1511         return newsk;
1512
1513 out_overflow:
1514         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1515 out:
1516         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1517         if (opt && opt != np->opt)
1518                 sock_kfree_s(sk, opt, opt->tot_len);
1519         dst_release(dst);
1520         return NULL;
1521 }
1522
1523 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1524 {
1525         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1526                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1527                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1528                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1529                         return 0;
1530                 }
1531         }
1532
1533         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1534                                               &ipv6_hdr(skb)->saddr,
1535                                               &ipv6_hdr(skb)->daddr, 0));
1536
1537         if (skb->len <= 76) {
1538                 return __skb_checksum_complete(skb);
1539         }
1540         return 0;
1541 }
1542
1543 /* The socket must have it's spinlock held when we get
1544  * here.
1545  *
1546  * We have a potential double-lock case here, so even when
1547  * doing backlog processing we use the BH locking scheme.
1548  * This is because we cannot sleep with the original spinlock
1549  * held.
1550  */
1551 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1552 {
1553         struct ipv6_pinfo *np = inet6_sk(sk);
1554         struct tcp_sock *tp;
1555         struct sk_buff *opt_skb = NULL;
1556
1557         /* Imagine: socket is IPv6. IPv4 packet arrives,
1558            goes to IPv4 receive handler and backlogged.
1559            From backlog it always goes here. Kerboom...
1560            Fortunately, tcp_rcv_established and rcv_established
1561            handle them correctly, but it is not case with
1562            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1563          */
1564
1565         if (skb->protocol == htons(ETH_P_IP))
1566                 return tcp_v4_do_rcv(sk, skb);
1567
1568 #ifdef CONFIG_TCP_MD5SIG
1569         if (tcp_v6_inbound_md5_hash (sk, skb))
1570                 goto discard;
1571 #endif
1572
1573         if (sk_filter(sk, skb))
1574                 goto discard;
1575
1576         /*
1577          *      socket locking is here for SMP purposes as backlog rcv
1578          *      is currently called with bh processing disabled.
1579          */
1580
1581         /* Do Stevens' IPV6_PKTOPTIONS.
1582
1583            Yes, guys, it is the only place in our code, where we
1584            may make it not affecting IPv4.
1585            The rest of code is protocol independent,
1586            and I do not like idea to uglify IPv4.
1587
1588            Actually, all the idea behind IPV6_PKTOPTIONS
1589            looks not very well thought. For now we latch
1590            options, received in the last packet, enqueued
1591            by tcp. Feel free to propose better solution.
1592                                                --ANK (980728)
1593          */
1594         if (np->rxopt.all)
1595                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1596
1597         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1598                 TCP_CHECK_TIMER(sk);
1599                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1600                         goto reset;
1601                 TCP_CHECK_TIMER(sk);
1602                 if (opt_skb)
1603                         goto ipv6_pktoptions;
1604                 return 0;
1605         }
1606
1607         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1608                 goto csum_err;
1609
1610         if (sk->sk_state == TCP_LISTEN) {
1611                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1612                 if (!nsk)
1613                         goto discard;
1614
1615                 /*
1616                  * Queue it on the new socket if the new socket is active,
1617                  * otherwise we just shortcircuit this and continue with
1618                  * the new socket..
1619                  */
1620                 if(nsk != sk) {
1621                         if (tcp_child_process(sk, nsk, skb))
1622                                 goto reset;
1623                         if (opt_skb)
1624                                 __kfree_skb(opt_skb);
1625                         return 0;
1626                 }
1627         }
1628
1629         TCP_CHECK_TIMER(sk);
1630         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1631                 goto reset;
1632         TCP_CHECK_TIMER(sk);
1633         if (opt_skb)
1634                 goto ipv6_pktoptions;
1635         return 0;
1636
1637 reset:
1638         tcp_v6_send_reset(sk, skb);
1639 discard:
1640         if (opt_skb)
1641                 __kfree_skb(opt_skb);
1642         kfree_skb(skb);
1643         return 0;
1644 csum_err:
1645         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1646         goto discard;
1647
1648
1649 ipv6_pktoptions:
1650         /* Do you ask, what is it?
1651
1652            1. skb was enqueued by tcp.
1653            2. skb is added to tail of read queue, rather than out of order.
1654            3. socket is not in passive state.
1655            4. Finally, it really contains options, which user wants to receive.
1656          */
1657         tp = tcp_sk(sk);
1658         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1659             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1660                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1661                         np->mcast_oif = inet6_iif(opt_skb);
1662                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1663                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1664                 if (ipv6_opt_accepted(sk, opt_skb)) {
1665                         skb_set_owner_r(opt_skb, sk);
1666                         opt_skb = xchg(&np->pktoptions, opt_skb);
1667                 } else {
1668                         __kfree_skb(opt_skb);
1669                         opt_skb = xchg(&np->pktoptions, NULL);
1670                 }
1671         }
1672
1673         kfree_skb(opt_skb);
1674         return 0;
1675 }
1676
1677 static int tcp_v6_rcv(struct sk_buff *skb)
1678 {
1679         struct tcphdr *th;
1680         struct sock *sk;
1681         int ret;
1682         struct net *net = dev_net(skb->dev);
1683
1684         if (skb->pkt_type != PACKET_HOST)
1685                 goto discard_it;
1686
1687         /*
1688          *      Count it even if it's bad.
1689          */
1690         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1691
1692         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1693                 goto discard_it;
1694
1695         th = tcp_hdr(skb);
1696
1697         if (th->doff < sizeof(struct tcphdr)/4)
1698                 goto bad_packet;
1699         if (!pskb_may_pull(skb, th->doff*4))
1700                 goto discard_it;
1701
1702         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1703                 goto bad_packet;
1704
1705         th = tcp_hdr(skb);
1706         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1707         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1708                                     skb->len - th->doff*4);
1709         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1710         TCP_SKB_CB(skb)->when = 0;
1711         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1712         TCP_SKB_CB(skb)->sacked = 0;
1713
1714         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1715         if (!sk)
1716                 goto no_tcp_socket;
1717
1718 process:
1719         if (sk->sk_state == TCP_TIME_WAIT)
1720                 goto do_time_wait;
1721
1722         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1723                 goto discard_and_relse;
1724
1725         if (sk_filter(sk, skb))
1726                 goto discard_and_relse;
1727
1728         skb->dev = NULL;
1729
1730         bh_lock_sock_nested(sk);
1731         ret = 0;
1732         if (!sock_owned_by_user(sk)) {
1733 #ifdef CONFIG_NET_DMA
1734                 struct tcp_sock *tp = tcp_sk(sk);
1735                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1736                         tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1737                 if (tp->ucopy.dma_chan)
1738                         ret = tcp_v6_do_rcv(sk, skb);
1739                 else
1740 #endif
1741                 {
1742                         if (!tcp_prequeue(sk, skb))
1743                                 ret = tcp_v6_do_rcv(sk, skb);
1744                 }
1745         } else if (unlikely(sk_add_backlog(sk, skb))) {
1746                 bh_unlock_sock(sk);
1747                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1748                 goto discard_and_relse;
1749         }
1750         bh_unlock_sock(sk);
1751
1752         sock_put(sk);
1753         return ret ? -1 : 0;
1754
1755 no_tcp_socket:
1756         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1757                 goto discard_it;
1758
1759         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1760 bad_packet:
1761                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1762         } else {
1763                 tcp_v6_send_reset(NULL, skb);
1764         }
1765
1766 discard_it:
1767
1768         /*
1769          *      Discard frame
1770          */
1771
1772         kfree_skb(skb);
1773         return 0;
1774
1775 discard_and_relse:
1776         sock_put(sk);
1777         goto discard_it;
1778
1779 do_time_wait:
1780         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1781                 inet_twsk_put(inet_twsk(sk));
1782                 goto discard_it;
1783         }
1784
1785         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1786                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1787                 inet_twsk_put(inet_twsk(sk));
1788                 goto discard_it;
1789         }
1790
1791         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1792         case TCP_TW_SYN:
1793         {
1794                 struct sock *sk2;
1795
1796                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1797                                             &ipv6_hdr(skb)->daddr,
1798                                             ntohs(th->dest), inet6_iif(skb));
1799                 if (sk2 != NULL) {
1800                         struct inet_timewait_sock *tw = inet_twsk(sk);
1801                         inet_twsk_deschedule(tw, &tcp_death_row);
1802                         inet_twsk_put(tw);
1803                         sk = sk2;
1804                         goto process;
1805                 }
1806                 /* Fall through to ACK */
1807         }
1808         case TCP_TW_ACK:
1809                 tcp_v6_timewait_ack(sk, skb);
1810                 break;
1811         case TCP_TW_RST:
1812                 goto no_tcp_socket;
1813         case TCP_TW_SUCCESS:;
1814         }
1815         goto discard_it;
1816 }
1817
1818 static int tcp_v6_remember_stamp(struct sock *sk)
1819 {
1820         /* Alas, not yet... */
1821         return 0;
1822 }
1823
1824 static const struct inet_connection_sock_af_ops ipv6_specific = {
1825         .queue_xmit        = inet6_csk_xmit,
1826         .send_check        = tcp_v6_send_check,
1827         .rebuild_header    = inet6_sk_rebuild_header,
1828         .conn_request      = tcp_v6_conn_request,
1829         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1830         .remember_stamp    = tcp_v6_remember_stamp,
1831         .net_header_len    = sizeof(struct ipv6hdr),
1832         .setsockopt        = ipv6_setsockopt,
1833         .getsockopt        = ipv6_getsockopt,
1834         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1835         .sockaddr_len      = sizeof(struct sockaddr_in6),
1836         .bind_conflict     = inet6_csk_bind_conflict,
1837 #ifdef CONFIG_COMPAT
1838         .compat_setsockopt = compat_ipv6_setsockopt,
1839         .compat_getsockopt = compat_ipv6_getsockopt,
1840 #endif
1841 };
1842
1843 #ifdef CONFIG_TCP_MD5SIG
1844 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1845         .md5_lookup     =       tcp_v6_md5_lookup,
1846         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1847         .md5_add        =       tcp_v6_md5_add_func,
1848         .md5_parse      =       tcp_v6_parse_md5_keys,
1849 };
1850 #endif
1851
1852 /*
1853  *      TCP over IPv4 via INET6 API
1854  */
1855
1856 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1857         .queue_xmit        = ip_queue_xmit,
1858         .send_check        = tcp_v4_send_check,
1859         .rebuild_header    = inet_sk_rebuild_header,
1860         .conn_request      = tcp_v6_conn_request,
1861         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1862         .remember_stamp    = tcp_v4_remember_stamp,
1863         .net_header_len    = sizeof(struct iphdr),
1864         .setsockopt        = ipv6_setsockopt,
1865         .getsockopt        = ipv6_getsockopt,
1866         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1867         .sockaddr_len      = sizeof(struct sockaddr_in6),
1868         .bind_conflict     = inet6_csk_bind_conflict,
1869 #ifdef CONFIG_COMPAT
1870         .compat_setsockopt = compat_ipv6_setsockopt,
1871         .compat_getsockopt = compat_ipv6_getsockopt,
1872 #endif
1873 };
1874
1875 #ifdef CONFIG_TCP_MD5SIG
1876 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1877         .md5_lookup     =       tcp_v4_md5_lookup,
1878         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1879         .md5_add        =       tcp_v6_md5_add_func,
1880         .md5_parse      =       tcp_v6_parse_md5_keys,
1881 };
1882 #endif
1883
1884 /* NOTE: A lot of things set to zero explicitly by call to
1885  *       sk_alloc() so need not be done here.
1886  */
1887 static int tcp_v6_init_sock(struct sock *sk)
1888 {
1889         struct inet_connection_sock *icsk = inet_csk(sk);
1890         struct tcp_sock *tp = tcp_sk(sk);
1891
1892         skb_queue_head_init(&tp->out_of_order_queue);
1893         tcp_init_xmit_timers(sk);
1894         tcp_prequeue_init(tp);
1895
1896         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1897         tp->mdev = TCP_TIMEOUT_INIT;
1898
1899         /* So many TCP implementations out there (incorrectly) count the
1900          * initial SYN frame in their delayed-ACK and congestion control
1901          * algorithms that we must have the following bandaid to talk
1902          * efficiently to them.  -DaveM
1903          */
1904         tp->snd_cwnd = 2;
1905
1906         /* See draft-stevens-tcpca-spec-01 for discussion of the
1907          * initialization of these values.
1908          */
1909         tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1910         tp->snd_cwnd_clamp = ~0;
1911         tp->mss_cache = TCP_MSS_DEFAULT;
1912
1913         tp->reordering = sysctl_tcp_reordering;
1914
1915         sk->sk_state = TCP_CLOSE;
1916
1917         icsk->icsk_af_ops = &ipv6_specific;
1918         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1919         icsk->icsk_sync_mss = tcp_sync_mss;
1920         sk->sk_write_space = sk_stream_write_space;
1921         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1922
1923 #ifdef CONFIG_TCP_MD5SIG
1924         tp->af_specific = &tcp_sock_ipv6_specific;
1925 #endif
1926
1927         /* TCP Cookie Transactions */
1928         if (sysctl_tcp_cookie_size > 0) {
1929                 /* Default, cookies without s_data_payload. */
1930                 tp->cookie_values =
1931                         kzalloc(sizeof(*tp->cookie_values),
1932                                 sk->sk_allocation);
1933                 if (tp->cookie_values != NULL)
1934                         kref_init(&tp->cookie_values->kref);
1935         }
1936         /* Presumed zeroed, in order of appearance:
1937          *      cookie_in_always, cookie_out_never,
1938          *      s_data_constant, s_data_in, s_data_out
1939          */
1940         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1941         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1942
1943         local_bh_disable();
1944         percpu_counter_inc(&tcp_sockets_allocated);
1945         local_bh_enable();
1946
1947         return 0;
1948 }
1949
1950 static void tcp_v6_destroy_sock(struct sock *sk)
1951 {
1952 #ifdef CONFIG_TCP_MD5SIG
1953         /* Clean up the MD5 key list */
1954         if (tcp_sk(sk)->md5sig_info)
1955                 tcp_v6_clear_md5_list(sk);
1956 #endif
1957         tcp_v4_destroy_sock(sk);
1958         inet6_destroy_sock(sk);
1959 }
1960
1961 #ifdef CONFIG_PROC_FS
1962 /* Proc filesystem TCPv6 sock list dumping. */
1963 static void get_openreq6(struct seq_file *seq,
1964                          struct sock *sk, struct request_sock *req, int i, int uid)
1965 {
1966         int ttd = req->expires - jiffies;
1967         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1968         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1969
1970         if (ttd < 0)
1971                 ttd = 0;
1972
1973         seq_printf(seq,
1974                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1975                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1976                    i,
1977                    src->s6_addr32[0], src->s6_addr32[1],
1978                    src->s6_addr32[2], src->s6_addr32[3],
1979                    ntohs(inet_rsk(req)->loc_port),
1980                    dest->s6_addr32[0], dest->s6_addr32[1],
1981                    dest->s6_addr32[2], dest->s6_addr32[3],
1982                    ntohs(inet_rsk(req)->rmt_port),
1983                    TCP_SYN_RECV,
1984                    0,0, /* could print option size, but that is af dependent. */
1985                    1,   /* timers active (only the expire timer) */
1986                    jiffies_to_clock_t(ttd),
1987                    req->retrans,
1988                    uid,
1989                    0,  /* non standard timer */
1990                    0, /* open_requests have no inode */
1991                    0, req);
1992 }
1993
1994 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1995 {
1996         struct in6_addr *dest, *src;
1997         __u16 destp, srcp;
1998         int timer_active;
1999         unsigned long timer_expires;
2000         struct inet_sock *inet = inet_sk(sp);
2001         struct tcp_sock *tp = tcp_sk(sp);
2002         const struct inet_connection_sock *icsk = inet_csk(sp);
2003         struct ipv6_pinfo *np = inet6_sk(sp);
2004
2005         dest  = &np->daddr;
2006         src   = &np->rcv_saddr;
2007         destp = ntohs(inet->inet_dport);
2008         srcp  = ntohs(inet->inet_sport);
2009
2010         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2011                 timer_active    = 1;
2012                 timer_expires   = icsk->icsk_timeout;
2013         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2014                 timer_active    = 4;
2015                 timer_expires   = icsk->icsk_timeout;
2016         } else if (timer_pending(&sp->sk_timer)) {
2017                 timer_active    = 2;
2018                 timer_expires   = sp->sk_timer.expires;
2019         } else {
2020                 timer_active    = 0;
2021                 timer_expires = jiffies;
2022         }
2023
2024         seq_printf(seq,
2025                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2026                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %lu %lu %u %u %d\n",
2027                    i,
2028                    src->s6_addr32[0], src->s6_addr32[1],
2029                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2030                    dest->s6_addr32[0], dest->s6_addr32[1],
2031                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2032                    sp->sk_state,
2033                    tp->write_seq-tp->snd_una,
2034                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2035                    timer_active,
2036                    jiffies_to_clock_t(timer_expires - jiffies),
2037                    icsk->icsk_retransmits,
2038                    sock_i_uid(sp),
2039                    icsk->icsk_probes_out,
2040                    sock_i_ino(sp),
2041                    atomic_read(&sp->sk_refcnt), sp,
2042                    jiffies_to_clock_t(icsk->icsk_rto),
2043                    jiffies_to_clock_t(icsk->icsk_ack.ato),
2044                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2045                    tp->snd_cwnd,
2046                    tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
2047                    );
2048 }
2049
2050 static void get_timewait6_sock(struct seq_file *seq,
2051                                struct inet_timewait_sock *tw, int i)
2052 {
2053         struct in6_addr *dest, *src;
2054         __u16 destp, srcp;
2055         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2056         int ttd = tw->tw_ttd - jiffies;
2057
2058         if (ttd < 0)
2059                 ttd = 0;
2060
2061         dest = &tw6->tw_v6_daddr;
2062         src  = &tw6->tw_v6_rcv_saddr;
2063         destp = ntohs(tw->tw_dport);
2064         srcp  = ntohs(tw->tw_sport);
2065
2066         seq_printf(seq,
2067                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2068                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2069                    i,
2070                    src->s6_addr32[0], src->s6_addr32[1],
2071                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2072                    dest->s6_addr32[0], dest->s6_addr32[1],
2073                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2074                    tw->tw_substate, 0, 0,
2075                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2076                    atomic_read(&tw->tw_refcnt), tw);
2077 }
2078
2079 static int tcp6_seq_show(struct seq_file *seq, void *v)
2080 {
2081         struct tcp_iter_state *st;
2082
2083         if (v == SEQ_START_TOKEN) {
2084                 seq_puts(seq,
2085                          "  sl  "
2086                          "local_address                         "
2087                          "remote_address                        "
2088                          "st tx_queue rx_queue tr tm->when retrnsmt"
2089                          "   uid  timeout inode\n");
2090                 goto out;
2091         }
2092         st = seq->private;
2093
2094         switch (st->state) {
2095         case TCP_SEQ_STATE_LISTENING:
2096         case TCP_SEQ_STATE_ESTABLISHED:
2097                 get_tcp6_sock(seq, v, st->num);
2098                 break;
2099         case TCP_SEQ_STATE_OPENREQ:
2100                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2101                 break;
2102         case TCP_SEQ_STATE_TIME_WAIT:
2103                 get_timewait6_sock(seq, v, st->num);
2104                 break;
2105         }
2106 out:
2107         return 0;
2108 }
2109
2110 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2111         .name           = "tcp6",
2112         .family         = AF_INET6,
2113         .seq_fops       = {
2114                 .owner          = THIS_MODULE,
2115         },
2116         .seq_ops        = {
2117                 .show           = tcp6_seq_show,
2118         },
2119 };
2120
2121 int __net_init tcp6_proc_init(struct net *net)
2122 {
2123         return tcp_proc_register(net, &tcp6_seq_afinfo);
2124 }
2125
2126 void tcp6_proc_exit(struct net *net)
2127 {
2128         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2129 }
2130 #endif
2131
2132 struct proto tcpv6_prot = {
2133         .name                   = "TCPv6",
2134         .owner                  = THIS_MODULE,
2135         .close                  = tcp_close,
2136         .connect                = tcp_v6_connect,
2137         .disconnect             = tcp_disconnect,
2138         .accept                 = inet_csk_accept,
2139         .ioctl                  = tcp_ioctl,
2140         .init                   = tcp_v6_init_sock,
2141         .destroy                = tcp_v6_destroy_sock,
2142         .shutdown               = tcp_shutdown,
2143         .setsockopt             = tcp_setsockopt,
2144         .getsockopt             = tcp_getsockopt,
2145         .recvmsg                = tcp_recvmsg,
2146         .backlog_rcv            = tcp_v6_do_rcv,
2147         .hash                   = tcp_v6_hash,
2148         .unhash                 = inet_unhash,
2149         .get_port               = inet_csk_get_port,
2150         .enter_memory_pressure  = tcp_enter_memory_pressure,
2151         .sockets_allocated      = &tcp_sockets_allocated,
2152         .memory_allocated       = &tcp_memory_allocated,
2153         .memory_pressure        = &tcp_memory_pressure,
2154         .orphan_count           = &tcp_orphan_count,
2155         .sysctl_mem             = sysctl_tcp_mem,
2156         .sysctl_wmem            = sysctl_tcp_wmem,
2157         .sysctl_rmem            = sysctl_tcp_rmem,
2158         .max_header             = MAX_TCP_HEADER,
2159         .obj_size               = sizeof(struct tcp6_sock),
2160         .slab_flags             = SLAB_DESTROY_BY_RCU,
2161         .twsk_prot              = &tcp6_timewait_sock_ops,
2162         .rsk_prot               = &tcp6_request_sock_ops,
2163         .h.hashinfo             = &tcp_hashinfo,
2164 #ifdef CONFIG_COMPAT
2165         .compat_setsockopt      = compat_tcp_setsockopt,
2166         .compat_getsockopt      = compat_tcp_getsockopt,
2167 #endif
2168 };
2169
2170 static const struct inet6_protocol tcpv6_protocol = {
2171         .handler        =       tcp_v6_rcv,
2172         .err_handler    =       tcp_v6_err,
2173         .gso_send_check =       tcp_v6_gso_send_check,
2174         .gso_segment    =       tcp_tso_segment,
2175         .gro_receive    =       tcp6_gro_receive,
2176         .gro_complete   =       tcp6_gro_complete,
2177         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2178 };
2179
2180 static struct inet_protosw tcpv6_protosw = {
2181         .type           =       SOCK_STREAM,
2182         .protocol       =       IPPROTO_TCP,
2183         .prot           =       &tcpv6_prot,
2184         .ops            =       &inet6_stream_ops,
2185         .no_check       =       0,
2186         .flags          =       INET_PROTOSW_PERMANENT |
2187                                 INET_PROTOSW_ICSK,
2188 };
2189
2190 static int __net_init tcpv6_net_init(struct net *net)
2191 {
2192         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2193                                     SOCK_RAW, IPPROTO_TCP, net);
2194 }
2195
2196 static void __net_exit tcpv6_net_exit(struct net *net)
2197 {
2198         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2199 }
2200
2201 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2202 {
2203         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2204 }
2205
2206 static struct pernet_operations tcpv6_net_ops = {
2207         .init       = tcpv6_net_init,
2208         .exit       = tcpv6_net_exit,
2209         .exit_batch = tcpv6_net_exit_batch,
2210 };
2211
2212 int __init tcpv6_init(void)
2213 {
2214         int ret;
2215
2216         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2217         if (ret)
2218                 goto out;
2219
2220         /* register inet6 protocol */
2221         ret = inet6_register_protosw(&tcpv6_protosw);
2222         if (ret)
2223                 goto out_tcpv6_protocol;
2224
2225         ret = register_pernet_subsys(&tcpv6_net_ops);
2226         if (ret)
2227                 goto out_tcpv6_protosw;
2228 out:
2229         return ret;
2230
2231 out_tcpv6_protocol:
2232         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2233 out_tcpv6_protosw:
2234         inet6_unregister_protosw(&tcpv6_protosw);
2235         goto out;
2236 }
2237
2238 void tcpv6_exit(void)
2239 {
2240         unregister_pernet_subsys(&tcpv6_net_ops);
2241         inet6_unregister_protosw(&tcpv6_protosw);
2242         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2243 }