Merge branches 'kbuild', 'packaging' and 'misc' of git://git.kernel.org/pub/scm/linux...
[pandora-kernel.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                                     const struct in6_addr *saddr,
80                                     const 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                                                    const 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                                    const struct in6_addr *saddr,
110                                    const 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, final;
133         struct rt6_info *rt;
134         struct flowi6 fl6;
135         struct dst_entry *dst;
136         int addr_type;
137         int err;
138
139         if (addr_len < SIN6_LEN_RFC2133)
140                 return -EINVAL;
141
142         if (usin->sin6_family != AF_INET6)
143                 return -EAFNOSUPPORT;
144
145         memset(&fl6, 0, sizeof(fl6));
146
147         if (np->sndflow) {
148                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
149                 IP6_ECN_flow_init(fl6.flowlabel);
150                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
151                         struct ip6_flowlabel *flowlabel;
152                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
153                         if (flowlabel == NULL)
154                                 return -EINVAL;
155                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
156                         fl6_sock_release(flowlabel);
157                 }
158         }
159
160         /*
161          *      connect() to INADDR_ANY means loopback (BSD'ism).
162          */
163
164         if(ipv6_addr_any(&usin->sin6_addr))
165                 usin->sin6_addr.s6_addr[15] = 0x1;
166
167         addr_type = ipv6_addr_type(&usin->sin6_addr);
168
169         if(addr_type & IPV6_ADDR_MULTICAST)
170                 return -ENETUNREACH;
171
172         if (addr_type&IPV6_ADDR_LINKLOCAL) {
173                 if (addr_len >= sizeof(struct sockaddr_in6) &&
174                     usin->sin6_scope_id) {
175                         /* If interface is set while binding, indices
176                          * must coincide.
177                          */
178                         if (sk->sk_bound_dev_if &&
179                             sk->sk_bound_dev_if != usin->sin6_scope_id)
180                                 return -EINVAL;
181
182                         sk->sk_bound_dev_if = usin->sin6_scope_id;
183                 }
184
185                 /* Connect to link-local address requires an interface */
186                 if (!sk->sk_bound_dev_if)
187                         return -EINVAL;
188         }
189
190         if (tp->rx_opt.ts_recent_stamp &&
191             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
192                 tp->rx_opt.ts_recent = 0;
193                 tp->rx_opt.ts_recent_stamp = 0;
194                 tp->write_seq = 0;
195         }
196
197         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
198         np->flow_label = fl6.flowlabel;
199
200         /*
201          *      TCP over IPv4
202          */
203
204         if (addr_type == IPV6_ADDR_MAPPED) {
205                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
206                 struct sockaddr_in sin;
207
208                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
209
210                 if (__ipv6_only_sock(sk))
211                         return -ENETUNREACH;
212
213                 sin.sin_family = AF_INET;
214                 sin.sin_port = usin->sin6_port;
215                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
216
217                 icsk->icsk_af_ops = &ipv6_mapped;
218                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
219 #ifdef CONFIG_TCP_MD5SIG
220                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
221 #endif
222
223                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
224
225                 if (err) {
226                         icsk->icsk_ext_hdr_len = exthdrlen;
227                         icsk->icsk_af_ops = &ipv6_specific;
228                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
229 #ifdef CONFIG_TCP_MD5SIG
230                         tp->af_specific = &tcp_sock_ipv6_specific;
231 #endif
232                         goto failure;
233                 } else {
234                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
235                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
236                                                &np->rcv_saddr);
237                 }
238
239                 return err;
240         }
241
242         if (!ipv6_addr_any(&np->rcv_saddr))
243                 saddr = &np->rcv_saddr;
244
245         fl6.flowi6_proto = IPPROTO_TCP;
246         ipv6_addr_copy(&fl6.daddr, &np->daddr);
247         ipv6_addr_copy(&fl6.saddr,
248                        (saddr ? saddr : &np->saddr));
249         fl6.flowi6_oif = sk->sk_bound_dev_if;
250         fl6.flowi6_mark = sk->sk_mark;
251         fl6.fl6_dport = usin->sin6_port;
252         fl6.fl6_sport = inet->inet_sport;
253
254         final_p = fl6_update_dst(&fl6, np->opt, &final);
255
256         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
257
258         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
259         if (IS_ERR(dst)) {
260                 err = PTR_ERR(dst);
261                 goto failure;
262         }
263
264         if (saddr == NULL) {
265                 saddr = &fl6.saddr;
266                 ipv6_addr_copy(&np->rcv_saddr, saddr);
267         }
268
269         /* set the source address */
270         ipv6_addr_copy(&np->saddr, saddr);
271         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
272
273         sk->sk_gso_type = SKB_GSO_TCPV6;
274         __ip6_dst_store(sk, dst, NULL, NULL);
275
276         rt = (struct rt6_info *) dst;
277         if (tcp_death_row.sysctl_tw_recycle &&
278             !tp->rx_opt.ts_recent_stamp &&
279             ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
280                 struct inet_peer *peer = rt6_get_peer(rt);
281                 /*
282                  * VJ's idea. We save last timestamp seen from
283                  * the destination in peer table, when entering state
284                  * TIME-WAIT * and initialize rx_opt.ts_recent from it,
285                  * when trying new connection.
286                  */
287                 if (peer) {
288                         inet_peer_refcheck(peer);
289                         if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
290                                 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
291                                 tp->rx_opt.ts_recent = peer->tcp_ts;
292                         }
293                 }
294         }
295
296         icsk->icsk_ext_hdr_len = 0;
297         if (np->opt)
298                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
299                                           np->opt->opt_nflen);
300
301         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
302
303         inet->inet_dport = usin->sin6_port;
304
305         tcp_set_state(sk, TCP_SYN_SENT);
306         err = inet6_hash_connect(&tcp_death_row, sk);
307         if (err)
308                 goto late_failure;
309
310         if (!tp->write_seq)
311                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
312                                                              np->daddr.s6_addr32,
313                                                              inet->inet_sport,
314                                                              inet->inet_dport);
315
316         err = tcp_connect(sk);
317         if (err)
318                 goto late_failure;
319
320         return 0;
321
322 late_failure:
323         tcp_set_state(sk, TCP_CLOSE);
324         __sk_dst_reset(sk);
325 failure:
326         inet->inet_dport = 0;
327         sk->sk_route_caps = 0;
328         return err;
329 }
330
331 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
332                 u8 type, u8 code, int offset, __be32 info)
333 {
334         const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
335         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
336         struct ipv6_pinfo *np;
337         struct sock *sk;
338         int err;
339         struct tcp_sock *tp;
340         __u32 seq;
341         struct net *net = dev_net(skb->dev);
342
343         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
344                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
345
346         if (sk == NULL) {
347                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
348                                    ICMP6_MIB_INERRORS);
349                 return;
350         }
351
352         if (sk->sk_state == TCP_TIME_WAIT) {
353                 inet_twsk_put(inet_twsk(sk));
354                 return;
355         }
356
357         bh_lock_sock(sk);
358         if (sock_owned_by_user(sk))
359                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
360
361         if (sk->sk_state == TCP_CLOSE)
362                 goto out;
363
364         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
365                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
366                 goto out;
367         }
368
369         tp = tcp_sk(sk);
370         seq = ntohl(th->seq);
371         if (sk->sk_state != TCP_LISTEN &&
372             !between(seq, tp->snd_una, tp->snd_nxt)) {
373                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
374                 goto out;
375         }
376
377         np = inet6_sk(sk);
378
379         if (type == ICMPV6_PKT_TOOBIG) {
380                 struct dst_entry *dst;
381
382                 if (sock_owned_by_user(sk))
383                         goto out;
384                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
385                         goto out;
386
387                 /* icmp should have updated the destination cache entry */
388                 dst = __sk_dst_check(sk, np->dst_cookie);
389
390                 if (dst == NULL) {
391                         struct inet_sock *inet = inet_sk(sk);
392                         struct flowi6 fl6;
393
394                         /* BUGGG_FUTURE: Again, it is not clear how
395                            to handle rthdr case. Ignore this complexity
396                            for now.
397                          */
398                         memset(&fl6, 0, sizeof(fl6));
399                         fl6.flowi6_proto = IPPROTO_TCP;
400                         ipv6_addr_copy(&fl6.daddr, &np->daddr);
401                         ipv6_addr_copy(&fl6.saddr, &np->saddr);
402                         fl6.flowi6_oif = sk->sk_bound_dev_if;
403                         fl6.flowi6_mark = sk->sk_mark;
404                         fl6.fl6_dport = inet->inet_dport;
405                         fl6.fl6_sport = inet->inet_sport;
406                         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
407
408                         dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
409                         if (IS_ERR(dst)) {
410                                 sk->sk_err_soft = -PTR_ERR(dst);
411                                 goto out;
412                         }
413
414                 } else
415                         dst_hold(dst);
416
417                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
418                         tcp_sync_mss(sk, dst_mtu(dst));
419                         tcp_simple_retransmit(sk);
420                 } /* else let the usual retransmit timer handle it */
421                 dst_release(dst);
422                 goto out;
423         }
424
425         icmpv6_err_convert(type, code, &err);
426
427         /* Might be for an request_sock */
428         switch (sk->sk_state) {
429                 struct request_sock *req, **prev;
430         case TCP_LISTEN:
431                 if (sock_owned_by_user(sk))
432                         goto out;
433
434                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
435                                            &hdr->saddr, inet6_iif(skb));
436                 if (!req)
437                         goto out;
438
439                 /* ICMPs are not backlogged, hence we cannot get
440                  * an established socket here.
441                  */
442                 WARN_ON(req->sk != NULL);
443
444                 if (seq != tcp_rsk(req)->snt_isn) {
445                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
446                         goto out;
447                 }
448
449                 inet_csk_reqsk_queue_drop(sk, req, prev);
450                 goto out;
451
452         case TCP_SYN_SENT:
453         case TCP_SYN_RECV:  /* Cannot happen.
454                                It can, it SYNs are crossed. --ANK */
455                 if (!sock_owned_by_user(sk)) {
456                         sk->sk_err = err;
457                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
458
459                         tcp_done(sk);
460                 } else
461                         sk->sk_err_soft = err;
462                 goto out;
463         }
464
465         if (!sock_owned_by_user(sk) && np->recverr) {
466                 sk->sk_err = err;
467                 sk->sk_error_report(sk);
468         } else
469                 sk->sk_err_soft = err;
470
471 out:
472         bh_unlock_sock(sk);
473         sock_put(sk);
474 }
475
476
477 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
478                               struct request_values *rvp)
479 {
480         struct inet6_request_sock *treq = inet6_rsk(req);
481         struct ipv6_pinfo *np = inet6_sk(sk);
482         struct sk_buff * skb;
483         struct ipv6_txoptions *opt = NULL;
484         struct in6_addr * final_p, final;
485         struct flowi6 fl6;
486         struct dst_entry *dst;
487         int err;
488
489         memset(&fl6, 0, sizeof(fl6));
490         fl6.flowi6_proto = IPPROTO_TCP;
491         ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
492         ipv6_addr_copy(&fl6.saddr, &treq->loc_addr);
493         fl6.flowlabel = 0;
494         fl6.flowi6_oif = treq->iif;
495         fl6.flowi6_mark = sk->sk_mark;
496         fl6.fl6_dport = inet_rsk(req)->rmt_port;
497         fl6.fl6_sport = inet_rsk(req)->loc_port;
498         security_req_classify_flow(req, flowi6_to_flowi(&fl6));
499
500         opt = np->opt;
501         final_p = fl6_update_dst(&fl6, opt, &final);
502
503         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
504         if (IS_ERR(dst)) {
505                 err = PTR_ERR(dst);
506                 dst = NULL;
507                 goto done;
508         }
509         skb = tcp_make_synack(sk, dst, req, rvp);
510         err = -ENOMEM;
511         if (skb) {
512                 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
513
514                 ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
515                 err = ip6_xmit(sk, skb, &fl6, opt);
516                 err = net_xmit_eval(err);
517         }
518
519 done:
520         if (opt && opt != np->opt)
521                 sock_kfree_s(sk, opt, opt->tot_len);
522         dst_release(dst);
523         return err;
524 }
525
526 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
527                              struct request_values *rvp)
528 {
529         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
530         return tcp_v6_send_synack(sk, req, rvp);
531 }
532
533 static inline void syn_flood_warning(struct sk_buff *skb)
534 {
535 #ifdef CONFIG_SYN_COOKIES
536         if (sysctl_tcp_syncookies)
537                 printk(KERN_INFO
538                        "TCPv6: Possible SYN flooding on port %d. "
539                        "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
540         else
541 #endif
542                 printk(KERN_INFO
543                        "TCPv6: Possible SYN flooding on port %d. "
544                        "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
545 }
546
547 static void tcp_v6_reqsk_destructor(struct request_sock *req)
548 {
549         kfree_skb(inet6_rsk(req)->pktopts);
550 }
551
552 #ifdef CONFIG_TCP_MD5SIG
553 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
554                                                    const struct in6_addr *addr)
555 {
556         struct tcp_sock *tp = tcp_sk(sk);
557         int i;
558
559         BUG_ON(tp == NULL);
560
561         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
562                 return NULL;
563
564         for (i = 0; i < tp->md5sig_info->entries6; i++) {
565                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
566                         return &tp->md5sig_info->keys6[i].base;
567         }
568         return NULL;
569 }
570
571 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
572                                                 struct sock *addr_sk)
573 {
574         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
575 }
576
577 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
578                                                       struct request_sock *req)
579 {
580         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
581 }
582
583 static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer,
584                              char *newkey, u8 newkeylen)
585 {
586         /* Add key to the list */
587         struct tcp_md5sig_key *key;
588         struct tcp_sock *tp = tcp_sk(sk);
589         struct tcp6_md5sig_key *keys;
590
591         key = tcp_v6_md5_do_lookup(sk, peer);
592         if (key) {
593                 /* modify existing entry - just update that one */
594                 kfree(key->key);
595                 key->key = newkey;
596                 key->keylen = newkeylen;
597         } else {
598                 /* reallocate new list if current one is full. */
599                 if (!tp->md5sig_info) {
600                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
601                         if (!tp->md5sig_info) {
602                                 kfree(newkey);
603                                 return -ENOMEM;
604                         }
605                         sk_nocaps_add(sk, NETIF_F_GSO_MASK);
606                 }
607                 if (tcp_alloc_md5sig_pool(sk) == NULL) {
608                         kfree(newkey);
609                         return -ENOMEM;
610                 }
611                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
612                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
613                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
614
615                         if (!keys) {
616                                 tcp_free_md5sig_pool();
617                                 kfree(newkey);
618                                 return -ENOMEM;
619                         }
620
621                         if (tp->md5sig_info->entries6)
622                                 memmove(keys, tp->md5sig_info->keys6,
623                                         (sizeof (tp->md5sig_info->keys6[0]) *
624                                          tp->md5sig_info->entries6));
625
626                         kfree(tp->md5sig_info->keys6);
627                         tp->md5sig_info->keys6 = keys;
628                         tp->md5sig_info->alloced6++;
629                 }
630
631                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
632                                peer);
633                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
634                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
635
636                 tp->md5sig_info->entries6++;
637         }
638         return 0;
639 }
640
641 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
642                                u8 *newkey, __u8 newkeylen)
643 {
644         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
645                                  newkey, newkeylen);
646 }
647
648 static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer)
649 {
650         struct tcp_sock *tp = tcp_sk(sk);
651         int i;
652
653         for (i = 0; i < tp->md5sig_info->entries6; i++) {
654                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
655                         /* Free the key */
656                         kfree(tp->md5sig_info->keys6[i].base.key);
657                         tp->md5sig_info->entries6--;
658
659                         if (tp->md5sig_info->entries6 == 0) {
660                                 kfree(tp->md5sig_info->keys6);
661                                 tp->md5sig_info->keys6 = NULL;
662                                 tp->md5sig_info->alloced6 = 0;
663                         } else {
664                                 /* shrink the database */
665                                 if (tp->md5sig_info->entries6 != i)
666                                         memmove(&tp->md5sig_info->keys6[i],
667                                                 &tp->md5sig_info->keys6[i+1],
668                                                 (tp->md5sig_info->entries6 - i)
669                                                 * sizeof (tp->md5sig_info->keys6[0]));
670                         }
671                         tcp_free_md5sig_pool();
672                         return 0;
673                 }
674         }
675         return -ENOENT;
676 }
677
678 static void tcp_v6_clear_md5_list (struct sock *sk)
679 {
680         struct tcp_sock *tp = tcp_sk(sk);
681         int i;
682
683         if (tp->md5sig_info->entries6) {
684                 for (i = 0; i < tp->md5sig_info->entries6; i++)
685                         kfree(tp->md5sig_info->keys6[i].base.key);
686                 tp->md5sig_info->entries6 = 0;
687                 tcp_free_md5sig_pool();
688         }
689
690         kfree(tp->md5sig_info->keys6);
691         tp->md5sig_info->keys6 = NULL;
692         tp->md5sig_info->alloced6 = 0;
693
694         if (tp->md5sig_info->entries4) {
695                 for (i = 0; i < tp->md5sig_info->entries4; i++)
696                         kfree(tp->md5sig_info->keys4[i].base.key);
697                 tp->md5sig_info->entries4 = 0;
698                 tcp_free_md5sig_pool();
699         }
700
701         kfree(tp->md5sig_info->keys4);
702         tp->md5sig_info->keys4 = NULL;
703         tp->md5sig_info->alloced4 = 0;
704 }
705
706 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
707                                   int optlen)
708 {
709         struct tcp_md5sig cmd;
710         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
711         u8 *newkey;
712
713         if (optlen < sizeof(cmd))
714                 return -EINVAL;
715
716         if (copy_from_user(&cmd, optval, sizeof(cmd)))
717                 return -EFAULT;
718
719         if (sin6->sin6_family != AF_INET6)
720                 return -EINVAL;
721
722         if (!cmd.tcpm_keylen) {
723                 if (!tcp_sk(sk)->md5sig_info)
724                         return -ENOENT;
725                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
726                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
727                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
728         }
729
730         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
731                 return -EINVAL;
732
733         if (!tcp_sk(sk)->md5sig_info) {
734                 struct tcp_sock *tp = tcp_sk(sk);
735                 struct tcp_md5sig_info *p;
736
737                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
738                 if (!p)
739                         return -ENOMEM;
740
741                 tp->md5sig_info = p;
742                 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
743         }
744
745         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
746         if (!newkey)
747                 return -ENOMEM;
748         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
749                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
750                                          newkey, cmd.tcpm_keylen);
751         }
752         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
753 }
754
755 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
756                                         const struct in6_addr *daddr,
757                                         const struct in6_addr *saddr, int nbytes)
758 {
759         struct tcp6_pseudohdr *bp;
760         struct scatterlist sg;
761
762         bp = &hp->md5_blk.ip6;
763         /* 1. TCP pseudo-header (RFC2460) */
764         ipv6_addr_copy(&bp->saddr, saddr);
765         ipv6_addr_copy(&bp->daddr, daddr);
766         bp->protocol = cpu_to_be32(IPPROTO_TCP);
767         bp->len = cpu_to_be32(nbytes);
768
769         sg_init_one(&sg, bp, sizeof(*bp));
770         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
771 }
772
773 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
774                                const struct in6_addr *daddr, struct in6_addr *saddr,
775                                struct tcphdr *th)
776 {
777         struct tcp_md5sig_pool *hp;
778         struct hash_desc *desc;
779
780         hp = tcp_get_md5sig_pool();
781         if (!hp)
782                 goto clear_hash_noput;
783         desc = &hp->md5_desc;
784
785         if (crypto_hash_init(desc))
786                 goto clear_hash;
787         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
788                 goto clear_hash;
789         if (tcp_md5_hash_header(hp, th))
790                 goto clear_hash;
791         if (tcp_md5_hash_key(hp, key))
792                 goto clear_hash;
793         if (crypto_hash_final(desc, md5_hash))
794                 goto clear_hash;
795
796         tcp_put_md5sig_pool();
797         return 0;
798
799 clear_hash:
800         tcp_put_md5sig_pool();
801 clear_hash_noput:
802         memset(md5_hash, 0, 16);
803         return 1;
804 }
805
806 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
807                                struct sock *sk, struct request_sock *req,
808                                struct sk_buff *skb)
809 {
810         const struct in6_addr *saddr, *daddr;
811         struct tcp_md5sig_pool *hp;
812         struct hash_desc *desc;
813         struct tcphdr *th = tcp_hdr(skb);
814
815         if (sk) {
816                 saddr = &inet6_sk(sk)->saddr;
817                 daddr = &inet6_sk(sk)->daddr;
818         } else if (req) {
819                 saddr = &inet6_rsk(req)->loc_addr;
820                 daddr = &inet6_rsk(req)->rmt_addr;
821         } else {
822                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
823                 saddr = &ip6h->saddr;
824                 daddr = &ip6h->daddr;
825         }
826
827         hp = tcp_get_md5sig_pool();
828         if (!hp)
829                 goto clear_hash_noput;
830         desc = &hp->md5_desc;
831
832         if (crypto_hash_init(desc))
833                 goto clear_hash;
834
835         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
836                 goto clear_hash;
837         if (tcp_md5_hash_header(hp, th))
838                 goto clear_hash;
839         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
840                 goto clear_hash;
841         if (tcp_md5_hash_key(hp, key))
842                 goto clear_hash;
843         if (crypto_hash_final(desc, md5_hash))
844                 goto clear_hash;
845
846         tcp_put_md5sig_pool();
847         return 0;
848
849 clear_hash:
850         tcp_put_md5sig_pool();
851 clear_hash_noput:
852         memset(md5_hash, 0, 16);
853         return 1;
854 }
855
856 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
857 {
858         __u8 *hash_location = NULL;
859         struct tcp_md5sig_key *hash_expected;
860         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
861         struct tcphdr *th = tcp_hdr(skb);
862         int genhash;
863         u8 newhash[16];
864
865         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
866         hash_location = tcp_parse_md5sig_option(th);
867
868         /* We've parsed the options - do we have a hash? */
869         if (!hash_expected && !hash_location)
870                 return 0;
871
872         if (hash_expected && !hash_location) {
873                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
874                 return 1;
875         }
876
877         if (!hash_expected && hash_location) {
878                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
879                 return 1;
880         }
881
882         /* check the signature */
883         genhash = tcp_v6_md5_hash_skb(newhash,
884                                       hash_expected,
885                                       NULL, NULL, skb);
886
887         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
888                 if (net_ratelimit()) {
889                         printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
890                                genhash ? "failed" : "mismatch",
891                                &ip6h->saddr, ntohs(th->source),
892                                &ip6h->daddr, ntohs(th->dest));
893                 }
894                 return 1;
895         }
896         return 0;
897 }
898 #endif
899
900 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
901         .family         =       AF_INET6,
902         .obj_size       =       sizeof(struct tcp6_request_sock),
903         .rtx_syn_ack    =       tcp_v6_rtx_synack,
904         .send_ack       =       tcp_v6_reqsk_send_ack,
905         .destructor     =       tcp_v6_reqsk_destructor,
906         .send_reset     =       tcp_v6_send_reset,
907         .syn_ack_timeout =      tcp_syn_ack_timeout,
908 };
909
910 #ifdef CONFIG_TCP_MD5SIG
911 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
912         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
913         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
914 };
915 #endif
916
917 static void __tcp_v6_send_check(struct sk_buff *skb,
918                                 const struct in6_addr *saddr, const struct in6_addr *daddr)
919 {
920         struct tcphdr *th = tcp_hdr(skb);
921
922         if (skb->ip_summed == CHECKSUM_PARTIAL) {
923                 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
924                 skb->csum_start = skb_transport_header(skb) - skb->head;
925                 skb->csum_offset = offsetof(struct tcphdr, check);
926         } else {
927                 th->check = tcp_v6_check(skb->len, saddr, daddr,
928                                          csum_partial(th, th->doff << 2,
929                                                       skb->csum));
930         }
931 }
932
933 static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
934 {
935         struct ipv6_pinfo *np = inet6_sk(sk);
936
937         __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
938 }
939
940 static int tcp_v6_gso_send_check(struct sk_buff *skb)
941 {
942         const struct ipv6hdr *ipv6h;
943         struct tcphdr *th;
944
945         if (!pskb_may_pull(skb, sizeof(*th)))
946                 return -EINVAL;
947
948         ipv6h = ipv6_hdr(skb);
949         th = tcp_hdr(skb);
950
951         th->check = 0;
952         skb->ip_summed = CHECKSUM_PARTIAL;
953         __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
954         return 0;
955 }
956
957 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
958                                          struct sk_buff *skb)
959 {
960         const struct ipv6hdr *iph = skb_gro_network_header(skb);
961
962         switch (skb->ip_summed) {
963         case CHECKSUM_COMPLETE:
964                 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
965                                   skb->csum)) {
966                         skb->ip_summed = CHECKSUM_UNNECESSARY;
967                         break;
968                 }
969
970                 /* fall through */
971         case CHECKSUM_NONE:
972                 NAPI_GRO_CB(skb)->flush = 1;
973                 return NULL;
974         }
975
976         return tcp_gro_receive(head, skb);
977 }
978
979 static int tcp6_gro_complete(struct sk_buff *skb)
980 {
981         const struct ipv6hdr *iph = ipv6_hdr(skb);
982         struct tcphdr *th = tcp_hdr(skb);
983
984         th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
985                                   &iph->saddr, &iph->daddr, 0);
986         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
987
988         return tcp_gro_complete(skb);
989 }
990
991 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
992                                  u32 ts, struct tcp_md5sig_key *key, int rst)
993 {
994         struct tcphdr *th = tcp_hdr(skb), *t1;
995         struct sk_buff *buff;
996         struct flowi6 fl6;
997         struct net *net = dev_net(skb_dst(skb)->dev);
998         struct sock *ctl_sk = net->ipv6.tcp_sk;
999         unsigned int tot_len = sizeof(struct tcphdr);
1000         struct dst_entry *dst;
1001         __be32 *topt;
1002
1003         if (ts)
1004                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1005 #ifdef CONFIG_TCP_MD5SIG
1006         if (key)
1007                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1008 #endif
1009
1010         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1011                          GFP_ATOMIC);
1012         if (buff == NULL)
1013                 return;
1014
1015         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1016
1017         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1018         skb_reset_transport_header(buff);
1019
1020         /* Swap the send and the receive. */
1021         memset(t1, 0, sizeof(*t1));
1022         t1->dest = th->source;
1023         t1->source = th->dest;
1024         t1->doff = tot_len / 4;
1025         t1->seq = htonl(seq);
1026         t1->ack_seq = htonl(ack);
1027         t1->ack = !rst || !th->ack;
1028         t1->rst = rst;
1029         t1->window = htons(win);
1030
1031         topt = (__be32 *)(t1 + 1);
1032
1033         if (ts) {
1034                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1035                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1036                 *topt++ = htonl(tcp_time_stamp);
1037                 *topt++ = htonl(ts);
1038         }
1039
1040 #ifdef CONFIG_TCP_MD5SIG
1041         if (key) {
1042                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1043                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1044                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1045                                     &ipv6_hdr(skb)->saddr,
1046                                     &ipv6_hdr(skb)->daddr, t1);
1047         }
1048 #endif
1049
1050         memset(&fl6, 0, sizeof(fl6));
1051         ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
1052         ipv6_addr_copy(&fl6.saddr, &ipv6_hdr(skb)->daddr);
1053
1054         buff->ip_summed = CHECKSUM_PARTIAL;
1055         buff->csum = 0;
1056
1057         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
1058
1059         fl6.flowi6_proto = IPPROTO_TCP;
1060         fl6.flowi6_oif = inet6_iif(skb);
1061         fl6.fl6_dport = t1->dest;
1062         fl6.fl6_sport = t1->source;
1063         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
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         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
1070         if (!IS_ERR(dst)) {
1071                 skb_dst_set(buff, dst);
1072                 ip6_xmit(ctl_sk, buff, &fl6, NULL);
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         kfree_skb(buff);
1080 }
1081
1082 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1083 {
1084         struct tcphdr *th = tcp_hdr(skb);
1085         u32 seq = 0, ack_seq = 0;
1086         struct tcp_md5sig_key *key = NULL;
1087
1088         if (th->rst)
1089                 return;
1090
1091         if (!ipv6_unicast_destination(skb))
1092                 return;
1093
1094 #ifdef CONFIG_TCP_MD5SIG
1095         if (sk)
1096                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1097 #endif
1098
1099         if (th->ack)
1100                 seq = ntohl(th->ack_seq);
1101         else
1102                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1103                           (th->doff << 2);
1104
1105         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1106 }
1107
1108 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1109                             struct tcp_md5sig_key *key)
1110 {
1111         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1112 }
1113
1114 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1115 {
1116         struct inet_timewait_sock *tw = inet_twsk(sk);
1117         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1118
1119         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1120                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1121                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1122
1123         inet_twsk_put(tw);
1124 }
1125
1126 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1127                                   struct request_sock *req)
1128 {
1129         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1130                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1131 }
1132
1133
1134 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1135 {
1136         struct request_sock *req, **prev;
1137         const struct tcphdr *th = tcp_hdr(skb);
1138         struct sock *nsk;
1139
1140         /* Find possible connection requests. */
1141         req = inet6_csk_search_req(sk, &prev, th->source,
1142                                    &ipv6_hdr(skb)->saddr,
1143                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1144         if (req)
1145                 return tcp_check_req(sk, skb, req, prev);
1146
1147         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1148                         &ipv6_hdr(skb)->saddr, th->source,
1149                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1150
1151         if (nsk) {
1152                 if (nsk->sk_state != TCP_TIME_WAIT) {
1153                         bh_lock_sock(nsk);
1154                         return nsk;
1155                 }
1156                 inet_twsk_put(inet_twsk(nsk));
1157                 return NULL;
1158         }
1159
1160 #ifdef CONFIG_SYN_COOKIES
1161         if (!th->syn)
1162                 sk = cookie_v6_check(sk, skb);
1163 #endif
1164         return sk;
1165 }
1166
1167 /* FIXME: this is substantially similar to the ipv4 code.
1168  * Can some kind of merge be done? -- erics
1169  */
1170 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1171 {
1172         struct tcp_extend_values tmp_ext;
1173         struct tcp_options_received tmp_opt;
1174         u8 *hash_location;
1175         struct request_sock *req;
1176         struct inet6_request_sock *treq;
1177         struct ipv6_pinfo *np = inet6_sk(sk);
1178         struct tcp_sock *tp = tcp_sk(sk);
1179         __u32 isn = TCP_SKB_CB(skb)->when;
1180         struct dst_entry *dst = NULL;
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 = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1236                 *mess++ ^= *d++;
1237                 *mess++ ^= *d++;
1238                 *mess++ ^= *d++;
1239                 *mess++ ^= *d++;
1240                 d = (__force u32 *)&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 || tmp_opt.tstamp_ok)
1275                 TCP_ECN_create_request(req, tcp_hdr(skb));
1276
1277         if (!isn) {
1278                 struct inet_peer *peer = NULL;
1279
1280                 if (ipv6_opt_accepted(sk, skb) ||
1281                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1282                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1283                         atomic_inc(&skb->users);
1284                         treq->pktopts = skb;
1285                 }
1286                 treq->iif = sk->sk_bound_dev_if;
1287
1288                 /* So that link locals have meaning */
1289                 if (!sk->sk_bound_dev_if &&
1290                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1291                         treq->iif = inet6_iif(skb);
1292
1293                 if (want_cookie) {
1294                         isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1295                         req->cookie_ts = tmp_opt.tstamp_ok;
1296                         goto have_isn;
1297                 }
1298
1299                 /* VJ's idea. We save last timestamp seen
1300                  * from the destination in peer table, when entering
1301                  * state TIME-WAIT, and check against it before
1302                  * accepting new connection request.
1303                  *
1304                  * If "isn" is not zero, this request hit alive
1305                  * timewait bucket, so that all the necessary checks
1306                  * are made in the function processing timewait state.
1307                  */
1308                 if (tmp_opt.saw_tstamp &&
1309                     tcp_death_row.sysctl_tw_recycle &&
1310                     (dst = inet6_csk_route_req(sk, req)) != NULL &&
1311                     (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1312                     ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1313                                     &treq->rmt_addr)) {
1314                         inet_peer_refcheck(peer);
1315                         if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1316                             (s32)(peer->tcp_ts - req->ts_recent) >
1317                                                         TCP_PAWS_WINDOW) {
1318                                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1319                                 goto drop_and_release;
1320                         }
1321                 }
1322                 /* Kill the following clause, if you dislike this way. */
1323                 else if (!sysctl_tcp_syncookies &&
1324                          (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1325                           (sysctl_max_syn_backlog >> 2)) &&
1326                          (!peer || !peer->tcp_ts_stamp) &&
1327                          (!dst || !dst_metric(dst, RTAX_RTT))) {
1328                         /* Without syncookies last quarter of
1329                          * backlog is filled with destinations,
1330                          * proven to be alive.
1331                          * It means that we continue to communicate
1332                          * to destinations, already remembered
1333                          * to the moment of synflood.
1334                          */
1335                         LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1336                                        &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1337                         goto drop_and_release;
1338                 }
1339
1340                 isn = tcp_v6_init_sequence(skb);
1341         }
1342 have_isn:
1343         tcp_rsk(req)->snt_isn = isn;
1344         tcp_rsk(req)->snt_synack = tcp_time_stamp;
1345
1346         security_inet_conn_request(sk, skb, req);
1347
1348         if (tcp_v6_send_synack(sk, req,
1349                                (struct request_values *)&tmp_ext) ||
1350             want_cookie)
1351                 goto drop_and_free;
1352
1353         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1354         return 0;
1355
1356 drop_and_release:
1357         dst_release(dst);
1358 drop_and_free:
1359         reqsk_free(req);
1360 drop:
1361         return 0; /* don't send reset */
1362 }
1363
1364 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1365                                           struct request_sock *req,
1366                                           struct dst_entry *dst)
1367 {
1368         struct inet6_request_sock *treq;
1369         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1370         struct tcp6_sock *newtcp6sk;
1371         struct inet_sock *newinet;
1372         struct tcp_sock *newtp;
1373         struct sock *newsk;
1374         struct ipv6_txoptions *opt;
1375 #ifdef CONFIG_TCP_MD5SIG
1376         struct tcp_md5sig_key *key;
1377 #endif
1378
1379         if (skb->protocol == htons(ETH_P_IP)) {
1380                 /*
1381                  *      v6 mapped
1382                  */
1383
1384                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1385
1386                 if (newsk == NULL)
1387                         return NULL;
1388
1389                 newtcp6sk = (struct tcp6_sock *)newsk;
1390                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1391
1392                 newinet = inet_sk(newsk);
1393                 newnp = inet6_sk(newsk);
1394                 newtp = tcp_sk(newsk);
1395
1396                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1397
1398                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1399
1400                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1401
1402                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1403
1404                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1405                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1406 #ifdef CONFIG_TCP_MD5SIG
1407                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1408 #endif
1409
1410                 newnp->pktoptions  = NULL;
1411                 newnp->opt         = NULL;
1412                 newnp->mcast_oif   = inet6_iif(skb);
1413                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1414
1415                 /*
1416                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1417                  * here, tcp_create_openreq_child now does this for us, see the comment in
1418                  * that function for the gory details. -acme
1419                  */
1420
1421                 /* It is tricky place. Until this moment IPv4 tcp
1422                    worked with IPv6 icsk.icsk_af_ops.
1423                    Sync it now.
1424                  */
1425                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1426
1427                 return newsk;
1428         }
1429
1430         treq = inet6_rsk(req);
1431         opt = np->opt;
1432
1433         if (sk_acceptq_is_full(sk))
1434                 goto out_overflow;
1435
1436         if (!dst) {
1437                 dst = inet6_csk_route_req(sk, req);
1438                 if (!dst)
1439                         goto out;
1440         }
1441
1442         newsk = tcp_create_openreq_child(sk, req, skb);
1443         if (newsk == NULL)
1444                 goto out_nonewsk;
1445
1446         /*
1447          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1448          * count here, tcp_create_openreq_child now does this for us, see the
1449          * comment in that function for the gory details. -acme
1450          */
1451
1452         newsk->sk_gso_type = SKB_GSO_TCPV6;
1453         __ip6_dst_store(newsk, dst, NULL, NULL);
1454
1455         newtcp6sk = (struct tcp6_sock *)newsk;
1456         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1457
1458         newtp = tcp_sk(newsk);
1459         newinet = inet_sk(newsk);
1460         newnp = inet6_sk(newsk);
1461
1462         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1463
1464         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1465         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1466         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1467         newsk->sk_bound_dev_if = treq->iif;
1468
1469         /* Now IPv6 options...
1470
1471            First: no IPv4 options.
1472          */
1473         newinet->inet_opt = NULL;
1474         newnp->ipv6_fl_list = NULL;
1475
1476         /* Clone RX bits */
1477         newnp->rxopt.all = np->rxopt.all;
1478
1479         /* Clone pktoptions received with SYN */
1480         newnp->pktoptions = NULL;
1481         if (treq->pktopts != NULL) {
1482                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1483                 kfree_skb(treq->pktopts);
1484                 treq->pktopts = NULL;
1485                 if (newnp->pktoptions)
1486                         skb_set_owner_r(newnp->pktoptions, newsk);
1487         }
1488         newnp->opt        = NULL;
1489         newnp->mcast_oif  = inet6_iif(skb);
1490         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1491
1492         /* Clone native IPv6 options from listening socket (if any)
1493
1494            Yes, keeping reference count would be much more clever,
1495            but we make one more one thing there: reattach optmem
1496            to newsk.
1497          */
1498         if (opt) {
1499                 newnp->opt = ipv6_dup_options(newsk, opt);
1500                 if (opt != np->opt)
1501                         sock_kfree_s(sk, opt, opt->tot_len);
1502         }
1503
1504         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1505         if (newnp->opt)
1506                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1507                                                      newnp->opt->opt_flen);
1508
1509         tcp_mtup_init(newsk);
1510         tcp_sync_mss(newsk, dst_mtu(dst));
1511         newtp->advmss = dst_metric_advmss(dst);
1512         tcp_initialize_rcv_mss(newsk);
1513         if (tcp_rsk(req)->snt_synack)
1514                 tcp_valid_rtt_meas(newsk,
1515                     tcp_time_stamp - tcp_rsk(req)->snt_synack);
1516         newtp->total_retrans = req->retrans;
1517
1518         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1519         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1520
1521 #ifdef CONFIG_TCP_MD5SIG
1522         /* Copy over the MD5 key from the original socket */
1523         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1524                 /* We're using one, so create a matching key
1525                  * on the newsk structure. If we fail to get
1526                  * memory, then we end up not copying the key
1527                  * across. Shucks.
1528                  */
1529                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1530                 if (newkey != NULL)
1531                         tcp_v6_md5_do_add(newsk, &newnp->daddr,
1532                                           newkey, key->keylen);
1533         }
1534 #endif
1535
1536         if (__inet_inherit_port(sk, newsk) < 0) {
1537                 sock_put(newsk);
1538                 goto out;
1539         }
1540         __inet6_hash(newsk, NULL);
1541
1542         return newsk;
1543
1544 out_overflow:
1545         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1546 out_nonewsk:
1547         if (opt && opt != np->opt)
1548                 sock_kfree_s(sk, opt, opt->tot_len);
1549         dst_release(dst);
1550 out:
1551         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1552         return NULL;
1553 }
1554
1555 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1556 {
1557         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1558                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1559                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1560                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1561                         return 0;
1562                 }
1563         }
1564
1565         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1566                                               &ipv6_hdr(skb)->saddr,
1567                                               &ipv6_hdr(skb)->daddr, 0));
1568
1569         if (skb->len <= 76) {
1570                 return __skb_checksum_complete(skb);
1571         }
1572         return 0;
1573 }
1574
1575 /* The socket must have it's spinlock held when we get
1576  * here.
1577  *
1578  * We have a potential double-lock case here, so even when
1579  * doing backlog processing we use the BH locking scheme.
1580  * This is because we cannot sleep with the original spinlock
1581  * held.
1582  */
1583 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1584 {
1585         struct ipv6_pinfo *np = inet6_sk(sk);
1586         struct tcp_sock *tp;
1587         struct sk_buff *opt_skb = NULL;
1588
1589         /* Imagine: socket is IPv6. IPv4 packet arrives,
1590            goes to IPv4 receive handler and backlogged.
1591            From backlog it always goes here. Kerboom...
1592            Fortunately, tcp_rcv_established and rcv_established
1593            handle them correctly, but it is not case with
1594            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1595          */
1596
1597         if (skb->protocol == htons(ETH_P_IP))
1598                 return tcp_v4_do_rcv(sk, skb);
1599
1600 #ifdef CONFIG_TCP_MD5SIG
1601         if (tcp_v6_inbound_md5_hash (sk, skb))
1602                 goto discard;
1603 #endif
1604
1605         if (sk_filter(sk, skb))
1606                 goto discard;
1607
1608         /*
1609          *      socket locking is here for SMP purposes as backlog rcv
1610          *      is currently called with bh processing disabled.
1611          */
1612
1613         /* Do Stevens' IPV6_PKTOPTIONS.
1614
1615            Yes, guys, it is the only place in our code, where we
1616            may make it not affecting IPv4.
1617            The rest of code is protocol independent,
1618            and I do not like idea to uglify IPv4.
1619
1620            Actually, all the idea behind IPV6_PKTOPTIONS
1621            looks not very well thought. For now we latch
1622            options, received in the last packet, enqueued
1623            by tcp. Feel free to propose better solution.
1624                                                --ANK (980728)
1625          */
1626         if (np->rxopt.all)
1627                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1628
1629         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1630                 sock_rps_save_rxhash(sk, skb->rxhash);
1631                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1632                         goto reset;
1633                 if (opt_skb)
1634                         goto ipv6_pktoptions;
1635                 return 0;
1636         }
1637
1638         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1639                 goto csum_err;
1640
1641         if (sk->sk_state == TCP_LISTEN) {
1642                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1643                 if (!nsk)
1644                         goto discard;
1645
1646                 /*
1647                  * Queue it on the new socket if the new socket is active,
1648                  * otherwise we just shortcircuit this and continue with
1649                  * the new socket..
1650                  */
1651                 if(nsk != sk) {
1652                         sock_rps_save_rxhash(nsk, skb->rxhash);
1653                         if (tcp_child_process(sk, nsk, skb))
1654                                 goto reset;
1655                         if (opt_skb)
1656                                 __kfree_skb(opt_skb);
1657                         return 0;
1658                 }
1659         } else
1660                 sock_rps_save_rxhash(sk, skb->rxhash);
1661
1662         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1663                 goto reset;
1664         if (opt_skb)
1665                 goto ipv6_pktoptions;
1666         return 0;
1667
1668 reset:
1669         tcp_v6_send_reset(sk, skb);
1670 discard:
1671         if (opt_skb)
1672                 __kfree_skb(opt_skb);
1673         kfree_skb(skb);
1674         return 0;
1675 csum_err:
1676         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1677         goto discard;
1678
1679
1680 ipv6_pktoptions:
1681         /* Do you ask, what is it?
1682
1683            1. skb was enqueued by tcp.
1684            2. skb is added to tail of read queue, rather than out of order.
1685            3. socket is not in passive state.
1686            4. Finally, it really contains options, which user wants to receive.
1687          */
1688         tp = tcp_sk(sk);
1689         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1690             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1691                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1692                         np->mcast_oif = inet6_iif(opt_skb);
1693                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1694                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1695                 if (ipv6_opt_accepted(sk, opt_skb)) {
1696                         skb_set_owner_r(opt_skb, sk);
1697                         opt_skb = xchg(&np->pktoptions, opt_skb);
1698                 } else {
1699                         __kfree_skb(opt_skb);
1700                         opt_skb = xchg(&np->pktoptions, NULL);
1701                 }
1702         }
1703
1704         kfree_skb(opt_skb);
1705         return 0;
1706 }
1707
1708 static int tcp_v6_rcv(struct sk_buff *skb)
1709 {
1710         struct tcphdr *th;
1711         const struct ipv6hdr *hdr;
1712         struct sock *sk;
1713         int ret;
1714         struct net *net = dev_net(skb->dev);
1715
1716         if (skb->pkt_type != PACKET_HOST)
1717                 goto discard_it;
1718
1719         /*
1720          *      Count it even if it's bad.
1721          */
1722         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1723
1724         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1725                 goto discard_it;
1726
1727         th = tcp_hdr(skb);
1728
1729         if (th->doff < sizeof(struct tcphdr)/4)
1730                 goto bad_packet;
1731         if (!pskb_may_pull(skb, th->doff*4))
1732                 goto discard_it;
1733
1734         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1735                 goto bad_packet;
1736
1737         th = tcp_hdr(skb);
1738         hdr = ipv6_hdr(skb);
1739         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1740         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1741                                     skb->len - th->doff*4);
1742         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1743         TCP_SKB_CB(skb)->when = 0;
1744         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(hdr);
1745         TCP_SKB_CB(skb)->sacked = 0;
1746
1747         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1748         if (!sk)
1749                 goto no_tcp_socket;
1750
1751 process:
1752         if (sk->sk_state == TCP_TIME_WAIT)
1753                 goto do_time_wait;
1754
1755         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1756                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1757                 goto discard_and_relse;
1758         }
1759
1760         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1761                 goto discard_and_relse;
1762
1763         if (sk_filter(sk, skb))
1764                 goto discard_and_relse;
1765
1766         skb->dev = NULL;
1767
1768         bh_lock_sock_nested(sk);
1769         ret = 0;
1770         if (!sock_owned_by_user(sk)) {
1771 #ifdef CONFIG_NET_DMA
1772                 struct tcp_sock *tp = tcp_sk(sk);
1773                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1774                         tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1775                 if (tp->ucopy.dma_chan)
1776                         ret = tcp_v6_do_rcv(sk, skb);
1777                 else
1778 #endif
1779                 {
1780                         if (!tcp_prequeue(sk, skb))
1781                                 ret = tcp_v6_do_rcv(sk, skb);
1782                 }
1783         } else if (unlikely(sk_add_backlog(sk, skb))) {
1784                 bh_unlock_sock(sk);
1785                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1786                 goto discard_and_relse;
1787         }
1788         bh_unlock_sock(sk);
1789
1790         sock_put(sk);
1791         return ret ? -1 : 0;
1792
1793 no_tcp_socket:
1794         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1795                 goto discard_it;
1796
1797         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1798 bad_packet:
1799                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1800         } else {
1801                 tcp_v6_send_reset(NULL, skb);
1802         }
1803
1804 discard_it:
1805
1806         /*
1807          *      Discard frame
1808          */
1809
1810         kfree_skb(skb);
1811         return 0;
1812
1813 discard_and_relse:
1814         sock_put(sk);
1815         goto discard_it;
1816
1817 do_time_wait:
1818         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1819                 inet_twsk_put(inet_twsk(sk));
1820                 goto discard_it;
1821         }
1822
1823         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1824                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1825                 inet_twsk_put(inet_twsk(sk));
1826                 goto discard_it;
1827         }
1828
1829         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1830         case TCP_TW_SYN:
1831         {
1832                 struct sock *sk2;
1833
1834                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1835                                             &ipv6_hdr(skb)->daddr,
1836                                             ntohs(th->dest), inet6_iif(skb));
1837                 if (sk2 != NULL) {
1838                         struct inet_timewait_sock *tw = inet_twsk(sk);
1839                         inet_twsk_deschedule(tw, &tcp_death_row);
1840                         inet_twsk_put(tw);
1841                         sk = sk2;
1842                         goto process;
1843                 }
1844                 /* Fall through to ACK */
1845         }
1846         case TCP_TW_ACK:
1847                 tcp_v6_timewait_ack(sk, skb);
1848                 break;
1849         case TCP_TW_RST:
1850                 goto no_tcp_socket;
1851         case TCP_TW_SUCCESS:;
1852         }
1853         goto discard_it;
1854 }
1855
1856 static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1857 {
1858         struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1859         struct ipv6_pinfo *np = inet6_sk(sk);
1860         struct inet_peer *peer;
1861
1862         if (!rt ||
1863             !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1864                 peer = inet_getpeer_v6(&np->daddr, 1);
1865                 *release_it = true;
1866         } else {
1867                 if (!rt->rt6i_peer)
1868                         rt6_bind_peer(rt, 1);
1869                 peer = rt->rt6i_peer;
1870                 *release_it = false;
1871         }
1872
1873         return peer;
1874 }
1875
1876 static void *tcp_v6_tw_get_peer(struct sock *sk)
1877 {
1878         struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1879         struct inet_timewait_sock *tw = inet_twsk(sk);
1880
1881         if (tw->tw_family == AF_INET)
1882                 return tcp_v4_tw_get_peer(sk);
1883
1884         return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1885 }
1886
1887 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1888         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1889         .twsk_unique    = tcp_twsk_unique,
1890         .twsk_destructor= tcp_twsk_destructor,
1891         .twsk_getpeer   = tcp_v6_tw_get_peer,
1892 };
1893
1894 static const struct inet_connection_sock_af_ops ipv6_specific = {
1895         .queue_xmit        = inet6_csk_xmit,
1896         .send_check        = tcp_v6_send_check,
1897         .rebuild_header    = inet6_sk_rebuild_header,
1898         .conn_request      = tcp_v6_conn_request,
1899         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1900         .get_peer          = tcp_v6_get_peer,
1901         .net_header_len    = sizeof(struct ipv6hdr),
1902         .setsockopt        = ipv6_setsockopt,
1903         .getsockopt        = ipv6_getsockopt,
1904         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1905         .sockaddr_len      = sizeof(struct sockaddr_in6),
1906         .bind_conflict     = inet6_csk_bind_conflict,
1907 #ifdef CONFIG_COMPAT
1908         .compat_setsockopt = compat_ipv6_setsockopt,
1909         .compat_getsockopt = compat_ipv6_getsockopt,
1910 #endif
1911 };
1912
1913 #ifdef CONFIG_TCP_MD5SIG
1914 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1915         .md5_lookup     =       tcp_v6_md5_lookup,
1916         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1917         .md5_add        =       tcp_v6_md5_add_func,
1918         .md5_parse      =       tcp_v6_parse_md5_keys,
1919 };
1920 #endif
1921
1922 /*
1923  *      TCP over IPv4 via INET6 API
1924  */
1925
1926 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1927         .queue_xmit        = ip_queue_xmit,
1928         .send_check        = tcp_v4_send_check,
1929         .rebuild_header    = inet_sk_rebuild_header,
1930         .conn_request      = tcp_v6_conn_request,
1931         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1932         .get_peer          = tcp_v4_get_peer,
1933         .net_header_len    = sizeof(struct iphdr),
1934         .setsockopt        = ipv6_setsockopt,
1935         .getsockopt        = ipv6_getsockopt,
1936         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1937         .sockaddr_len      = sizeof(struct sockaddr_in6),
1938         .bind_conflict     = inet6_csk_bind_conflict,
1939 #ifdef CONFIG_COMPAT
1940         .compat_setsockopt = compat_ipv6_setsockopt,
1941         .compat_getsockopt = compat_ipv6_getsockopt,
1942 #endif
1943 };
1944
1945 #ifdef CONFIG_TCP_MD5SIG
1946 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1947         .md5_lookup     =       tcp_v4_md5_lookup,
1948         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1949         .md5_add        =       tcp_v6_md5_add_func,
1950         .md5_parse      =       tcp_v6_parse_md5_keys,
1951 };
1952 #endif
1953
1954 /* NOTE: A lot of things set to zero explicitly by call to
1955  *       sk_alloc() so need not be done here.
1956  */
1957 static int tcp_v6_init_sock(struct sock *sk)
1958 {
1959         struct inet_connection_sock *icsk = inet_csk(sk);
1960         struct tcp_sock *tp = tcp_sk(sk);
1961
1962         skb_queue_head_init(&tp->out_of_order_queue);
1963         tcp_init_xmit_timers(sk);
1964         tcp_prequeue_init(tp);
1965
1966         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1967         tp->mdev = TCP_TIMEOUT_INIT;
1968
1969         /* So many TCP implementations out there (incorrectly) count the
1970          * initial SYN frame in their delayed-ACK and congestion control
1971          * algorithms that we must have the following bandaid to talk
1972          * efficiently to them.  -DaveM
1973          */
1974         tp->snd_cwnd = 2;
1975
1976         /* See draft-stevens-tcpca-spec-01 for discussion of the
1977          * initialization of these values.
1978          */
1979         tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1980         tp->snd_cwnd_clamp = ~0;
1981         tp->mss_cache = TCP_MSS_DEFAULT;
1982
1983         tp->reordering = sysctl_tcp_reordering;
1984
1985         sk->sk_state = TCP_CLOSE;
1986
1987         icsk->icsk_af_ops = &ipv6_specific;
1988         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1989         icsk->icsk_sync_mss = tcp_sync_mss;
1990         sk->sk_write_space = sk_stream_write_space;
1991         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1992
1993 #ifdef CONFIG_TCP_MD5SIG
1994         tp->af_specific = &tcp_sock_ipv6_specific;
1995 #endif
1996
1997         /* TCP Cookie Transactions */
1998         if (sysctl_tcp_cookie_size > 0) {
1999                 /* Default, cookies without s_data_payload. */
2000                 tp->cookie_values =
2001                         kzalloc(sizeof(*tp->cookie_values),
2002                                 sk->sk_allocation);
2003                 if (tp->cookie_values != NULL)
2004                         kref_init(&tp->cookie_values->kref);
2005         }
2006         /* Presumed zeroed, in order of appearance:
2007          *      cookie_in_always, cookie_out_never,
2008          *      s_data_constant, s_data_in, s_data_out
2009          */
2010         sk->sk_sndbuf = sysctl_tcp_wmem[1];
2011         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
2012
2013         local_bh_disable();
2014         percpu_counter_inc(&tcp_sockets_allocated);
2015         local_bh_enable();
2016
2017         return 0;
2018 }
2019
2020 static void tcp_v6_destroy_sock(struct sock *sk)
2021 {
2022 #ifdef CONFIG_TCP_MD5SIG
2023         /* Clean up the MD5 key list */
2024         if (tcp_sk(sk)->md5sig_info)
2025                 tcp_v6_clear_md5_list(sk);
2026 #endif
2027         tcp_v4_destroy_sock(sk);
2028         inet6_destroy_sock(sk);
2029 }
2030
2031 #ifdef CONFIG_PROC_FS
2032 /* Proc filesystem TCPv6 sock list dumping. */
2033 static void get_openreq6(struct seq_file *seq,
2034                          struct sock *sk, struct request_sock *req, int i, int uid)
2035 {
2036         int ttd = req->expires - jiffies;
2037         const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
2038         const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
2039
2040         if (ttd < 0)
2041                 ttd = 0;
2042
2043         seq_printf(seq,
2044                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2045                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2046                    i,
2047                    src->s6_addr32[0], src->s6_addr32[1],
2048                    src->s6_addr32[2], src->s6_addr32[3],
2049                    ntohs(inet_rsk(req)->loc_port),
2050                    dest->s6_addr32[0], dest->s6_addr32[1],
2051                    dest->s6_addr32[2], dest->s6_addr32[3],
2052                    ntohs(inet_rsk(req)->rmt_port),
2053                    TCP_SYN_RECV,
2054                    0,0, /* could print option size, but that is af dependent. */
2055                    1,   /* timers active (only the expire timer) */
2056                    jiffies_to_clock_t(ttd),
2057                    req->retrans,
2058                    uid,
2059                    0,  /* non standard timer */
2060                    0, /* open_requests have no inode */
2061                    0, req);
2062 }
2063
2064 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2065 {
2066         const struct in6_addr *dest, *src;
2067         __u16 destp, srcp;
2068         int timer_active;
2069         unsigned long timer_expires;
2070         struct inet_sock *inet = inet_sk(sp);
2071         struct tcp_sock *tp = tcp_sk(sp);
2072         const struct inet_connection_sock *icsk = inet_csk(sp);
2073         struct ipv6_pinfo *np = inet6_sk(sp);
2074
2075         dest  = &np->daddr;
2076         src   = &np->rcv_saddr;
2077         destp = ntohs(inet->inet_dport);
2078         srcp  = ntohs(inet->inet_sport);
2079
2080         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2081                 timer_active    = 1;
2082                 timer_expires   = icsk->icsk_timeout;
2083         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2084                 timer_active    = 4;
2085                 timer_expires   = icsk->icsk_timeout;
2086         } else if (timer_pending(&sp->sk_timer)) {
2087                 timer_active    = 2;
2088                 timer_expires   = sp->sk_timer.expires;
2089         } else {
2090                 timer_active    = 0;
2091                 timer_expires = jiffies;
2092         }
2093
2094         seq_printf(seq,
2095                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2096                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
2097                    i,
2098                    src->s6_addr32[0], src->s6_addr32[1],
2099                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2100                    dest->s6_addr32[0], dest->s6_addr32[1],
2101                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2102                    sp->sk_state,
2103                    tp->write_seq-tp->snd_una,
2104                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2105                    timer_active,
2106                    jiffies_to_clock_t(timer_expires - jiffies),
2107                    icsk->icsk_retransmits,
2108                    sock_i_uid(sp),
2109                    icsk->icsk_probes_out,
2110                    sock_i_ino(sp),
2111                    atomic_read(&sp->sk_refcnt), sp,
2112                    jiffies_to_clock_t(icsk->icsk_rto),
2113                    jiffies_to_clock_t(icsk->icsk_ack.ato),
2114                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2115                    tp->snd_cwnd,
2116                    tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
2117                    );
2118 }
2119
2120 static void get_timewait6_sock(struct seq_file *seq,
2121                                struct inet_timewait_sock *tw, int i)
2122 {
2123         const struct in6_addr *dest, *src;
2124         __u16 destp, srcp;
2125         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2126         int ttd = tw->tw_ttd - jiffies;
2127
2128         if (ttd < 0)
2129                 ttd = 0;
2130
2131         dest = &tw6->tw_v6_daddr;
2132         src  = &tw6->tw_v6_rcv_saddr;
2133         destp = ntohs(tw->tw_dport);
2134         srcp  = ntohs(tw->tw_sport);
2135
2136         seq_printf(seq,
2137                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2138                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2139                    i,
2140                    src->s6_addr32[0], src->s6_addr32[1],
2141                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2142                    dest->s6_addr32[0], dest->s6_addr32[1],
2143                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2144                    tw->tw_substate, 0, 0,
2145                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2146                    atomic_read(&tw->tw_refcnt), tw);
2147 }
2148
2149 static int tcp6_seq_show(struct seq_file *seq, void *v)
2150 {
2151         struct tcp_iter_state *st;
2152
2153         if (v == SEQ_START_TOKEN) {
2154                 seq_puts(seq,
2155                          "  sl  "
2156                          "local_address                         "
2157                          "remote_address                        "
2158                          "st tx_queue rx_queue tr tm->when retrnsmt"
2159                          "   uid  timeout inode\n");
2160                 goto out;
2161         }
2162         st = seq->private;
2163
2164         switch (st->state) {
2165         case TCP_SEQ_STATE_LISTENING:
2166         case TCP_SEQ_STATE_ESTABLISHED:
2167                 get_tcp6_sock(seq, v, st->num);
2168                 break;
2169         case TCP_SEQ_STATE_OPENREQ:
2170                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2171                 break;
2172         case TCP_SEQ_STATE_TIME_WAIT:
2173                 get_timewait6_sock(seq, v, st->num);
2174                 break;
2175         }
2176 out:
2177         return 0;
2178 }
2179
2180 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2181         .name           = "tcp6",
2182         .family         = AF_INET6,
2183         .seq_fops       = {
2184                 .owner          = THIS_MODULE,
2185         },
2186         .seq_ops        = {
2187                 .show           = tcp6_seq_show,
2188         },
2189 };
2190
2191 int __net_init tcp6_proc_init(struct net *net)
2192 {
2193         return tcp_proc_register(net, &tcp6_seq_afinfo);
2194 }
2195
2196 void tcp6_proc_exit(struct net *net)
2197 {
2198         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2199 }
2200 #endif
2201
2202 struct proto tcpv6_prot = {
2203         .name                   = "TCPv6",
2204         .owner                  = THIS_MODULE,
2205         .close                  = tcp_close,
2206         .connect                = tcp_v6_connect,
2207         .disconnect             = tcp_disconnect,
2208         .accept                 = inet_csk_accept,
2209         .ioctl                  = tcp_ioctl,
2210         .init                   = tcp_v6_init_sock,
2211         .destroy                = tcp_v6_destroy_sock,
2212         .shutdown               = tcp_shutdown,
2213         .setsockopt             = tcp_setsockopt,
2214         .getsockopt             = tcp_getsockopt,
2215         .recvmsg                = tcp_recvmsg,
2216         .sendmsg                = tcp_sendmsg,
2217         .sendpage               = tcp_sendpage,
2218         .backlog_rcv            = tcp_v6_do_rcv,
2219         .hash                   = tcp_v6_hash,
2220         .unhash                 = inet_unhash,
2221         .get_port               = inet_csk_get_port,
2222         .enter_memory_pressure  = tcp_enter_memory_pressure,
2223         .sockets_allocated      = &tcp_sockets_allocated,
2224         .memory_allocated       = &tcp_memory_allocated,
2225         .memory_pressure        = &tcp_memory_pressure,
2226         .orphan_count           = &tcp_orphan_count,
2227         .sysctl_mem             = sysctl_tcp_mem,
2228         .sysctl_wmem            = sysctl_tcp_wmem,
2229         .sysctl_rmem            = sysctl_tcp_rmem,
2230         .max_header             = MAX_TCP_HEADER,
2231         .obj_size               = sizeof(struct tcp6_sock),
2232         .slab_flags             = SLAB_DESTROY_BY_RCU,
2233         .twsk_prot              = &tcp6_timewait_sock_ops,
2234         .rsk_prot               = &tcp6_request_sock_ops,
2235         .h.hashinfo             = &tcp_hashinfo,
2236         .no_autobind            = true,
2237 #ifdef CONFIG_COMPAT
2238         .compat_setsockopt      = compat_tcp_setsockopt,
2239         .compat_getsockopt      = compat_tcp_getsockopt,
2240 #endif
2241 };
2242
2243 static const struct inet6_protocol tcpv6_protocol = {
2244         .handler        =       tcp_v6_rcv,
2245         .err_handler    =       tcp_v6_err,
2246         .gso_send_check =       tcp_v6_gso_send_check,
2247         .gso_segment    =       tcp_tso_segment,
2248         .gro_receive    =       tcp6_gro_receive,
2249         .gro_complete   =       tcp6_gro_complete,
2250         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2251 };
2252
2253 static struct inet_protosw tcpv6_protosw = {
2254         .type           =       SOCK_STREAM,
2255         .protocol       =       IPPROTO_TCP,
2256         .prot           =       &tcpv6_prot,
2257         .ops            =       &inet6_stream_ops,
2258         .no_check       =       0,
2259         .flags          =       INET_PROTOSW_PERMANENT |
2260                                 INET_PROTOSW_ICSK,
2261 };
2262
2263 static int __net_init tcpv6_net_init(struct net *net)
2264 {
2265         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2266                                     SOCK_RAW, IPPROTO_TCP, net);
2267 }
2268
2269 static void __net_exit tcpv6_net_exit(struct net *net)
2270 {
2271         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2272 }
2273
2274 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2275 {
2276         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2277 }
2278
2279 static struct pernet_operations tcpv6_net_ops = {
2280         .init       = tcpv6_net_init,
2281         .exit       = tcpv6_net_exit,
2282         .exit_batch = tcpv6_net_exit_batch,
2283 };
2284
2285 int __init tcpv6_init(void)
2286 {
2287         int ret;
2288
2289         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2290         if (ret)
2291                 goto out;
2292
2293         /* register inet6 protocol */
2294         ret = inet6_register_protosw(&tcpv6_protosw);
2295         if (ret)
2296                 goto out_tcpv6_protocol;
2297
2298         ret = register_pernet_subsys(&tcpv6_net_ops);
2299         if (ret)
2300                 goto out_tcpv6_protosw;
2301 out:
2302         return ret;
2303
2304 out_tcpv6_protocol:
2305         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2306 out_tcpv6_protosw:
2307         inet6_unregister_protosw(&tcpv6_protosw);
2308         goto out;
2309 }
2310
2311 void tcpv6_exit(void)
2312 {
2313         unregister_pernet_subsys(&tcpv6_net_ops);
2314         inet6_unregister_protosw(&tcpv6_protosw);
2315         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2316 }