treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 104
[sfrench/cifs-2.6.git] / net / sctp / ipv6.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2002, 2004
4  * Copyright (c) 2001 Nokia, Inc.
5  * Copyright (c) 2001 La Monte H.P. Yarroll
6  * Copyright (c) 2002-2003 Intel Corp.
7  *
8  * This file is part of the SCTP kernel implementation
9  *
10  * SCTP over IPv6.
11  *
12  * Please send any bug reports or fixes you make to the
13  * email address(es):
14  *    lksctp developers <linux-sctp@vger.kernel.org>
15  *
16  * Written or modified by:
17  *    Le Yanqun             <yanqun.le@nokia.com>
18  *    Hui Huang             <hui.huang@nokia.com>
19  *    La Monte H.P. Yarroll <piggy@acm.org>
20  *    Sridhar Samudrala     <sri@us.ibm.com>
21  *    Jon Grimm             <jgrimm@us.ibm.com>
22  *    Ardelle Fan           <ardelle.fan@intel.com>
23  *
24  * Based on:
25  *      linux/net/ipv6/tcp_ipv6.c
26  */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/netdevice.h>
39 #include <linux/init.h>
40 #include <linux/ipsec.h>
41 #include <linux/slab.h>
42
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46 #include <linux/seq_file.h>
47
48 #include <net/protocol.h>
49 #include <net/ndisc.h>
50 #include <net/ip.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/inet_common.h>
56 #include <net/inet_ecn.h>
57 #include <net/sctp/sctp.h>
58
59 #include <linux/uaccess.h>
60
61 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
62                                          union sctp_addr *s2);
63 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
64                               __be16 port);
65 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
66                             const union sctp_addr *addr2);
67
68 /* Event handler for inet6 address addition/deletion events.
69  * The sctp_local_addr_list needs to be protocted by a spin lock since
70  * multiple notifiers (say IPv4 and IPv6) may be running at the same
71  * time and thus corrupt the list.
72  * The reader side is protected with RCU.
73  */
74 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
75                                 void *ptr)
76 {
77         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
78         struct sctp_sockaddr_entry *addr = NULL;
79         struct sctp_sockaddr_entry *temp;
80         struct net *net = dev_net(ifa->idev->dev);
81         int found = 0;
82
83         switch (ev) {
84         case NETDEV_UP:
85                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
86                 if (addr) {
87                         addr->a.v6.sin6_family = AF_INET6;
88                         addr->a.v6.sin6_addr = ifa->addr;
89                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
90                         addr->valid = 1;
91                         spin_lock_bh(&net->sctp.local_addr_lock);
92                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
93                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
94                         spin_unlock_bh(&net->sctp.local_addr_lock);
95                 }
96                 break;
97         case NETDEV_DOWN:
98                 spin_lock_bh(&net->sctp.local_addr_lock);
99                 list_for_each_entry_safe(addr, temp,
100                                         &net->sctp.local_addr_list, list) {
101                         if (addr->a.sa.sa_family == AF_INET6 &&
102                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
103                                                 &ifa->addr)) {
104                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
105                                 found = 1;
106                                 addr->valid = 0;
107                                 list_del_rcu(&addr->list);
108                                 break;
109                         }
110                 }
111                 spin_unlock_bh(&net->sctp.local_addr_lock);
112                 if (found)
113                         kfree_rcu(addr, rcu);
114                 break;
115         }
116
117         return NOTIFY_DONE;
118 }
119
120 static struct notifier_block sctp_inet6addr_notifier = {
121         .notifier_call = sctp_inet6addr_event,
122 };
123
124 /* ICMP error handler. */
125 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
126                         u8 type, u8 code, int offset, __be32 info)
127 {
128         struct inet6_dev *idev;
129         struct sock *sk;
130         struct sctp_association *asoc;
131         struct sctp_transport *transport;
132         struct ipv6_pinfo *np;
133         __u16 saveip, savesctp;
134         int err, ret = 0;
135         struct net *net = dev_net(skb->dev);
136
137         idev = in6_dev_get(skb->dev);
138
139         /* Fix up skb to look at the embedded net header. */
140         saveip   = skb->network_header;
141         savesctp = skb->transport_header;
142         skb_reset_network_header(skb);
143         skb_set_transport_header(skb, offset);
144         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
145         /* Put back, the original pointers. */
146         skb->network_header   = saveip;
147         skb->transport_header = savesctp;
148         if (!sk) {
149                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
150                 ret = -ENOENT;
151                 goto out;
152         }
153
154         /* Warning:  The sock lock is held.  Remember to call
155          * sctp_err_finish!
156          */
157
158         switch (type) {
159         case ICMPV6_PKT_TOOBIG:
160                 if (ip6_sk_accept_pmtu(sk))
161                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
162                 goto out_unlock;
163         case ICMPV6_PARAMPROB:
164                 if (ICMPV6_UNK_NEXTHDR == code) {
165                         sctp_icmp_proto_unreachable(sk, asoc, transport);
166                         goto out_unlock;
167                 }
168                 break;
169         case NDISC_REDIRECT:
170                 sctp_icmp_redirect(sk, transport, skb);
171                 goto out_unlock;
172         default:
173                 break;
174         }
175
176         np = inet6_sk(sk);
177         icmpv6_err_convert(type, code, &err);
178         if (!sock_owned_by_user(sk) && np->recverr) {
179                 sk->sk_err = err;
180                 sk->sk_error_report(sk);
181         } else {  /* Only an error on timeout */
182                 sk->sk_err_soft = err;
183         }
184
185 out_unlock:
186         sctp_err_finish(sk, transport);
187 out:
188         if (likely(idev != NULL))
189                 in6_dev_put(idev);
190
191         return ret;
192 }
193
194 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
195 {
196         struct sock *sk = skb->sk;
197         struct ipv6_pinfo *np = inet6_sk(sk);
198         struct flowi6 *fl6 = &transport->fl.u.ip6;
199         __u8 tclass = np->tclass;
200         int res;
201
202         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
203                  skb->len, &fl6->saddr, &fl6->daddr);
204
205         if (transport->dscp & SCTP_DSCP_SET_MASK)
206                 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
207
208         if (INET_ECN_is_capable(tclass))
209                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
210
211         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
212                 skb->ignore_df = 1;
213
214         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
215
216         rcu_read_lock();
217         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
218                        tclass);
219         rcu_read_unlock();
220         return res;
221 }
222
223 /* Returns the dst cache entry for the given source and destination ip
224  * addresses.
225  */
226 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
227                             struct flowi *fl, struct sock *sk)
228 {
229         struct sctp_association *asoc = t->asoc;
230         struct dst_entry *dst = NULL;
231         struct flowi6 *fl6 = &fl->u.ip6;
232         struct sctp_bind_addr *bp;
233         struct ipv6_pinfo *np = inet6_sk(sk);
234         struct sctp_sockaddr_entry *laddr;
235         union sctp_addr *daddr = &t->ipaddr;
236         union sctp_addr dst_saddr;
237         struct in6_addr *final_p, final;
238         enum sctp_scope scope;
239         __u8 matchlen = 0;
240
241         memset(fl6, 0, sizeof(struct flowi6));
242         fl6->daddr = daddr->v6.sin6_addr;
243         fl6->fl6_dport = daddr->v6.sin6_port;
244         fl6->flowi6_proto = IPPROTO_SCTP;
245         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
246                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
247         else if (asoc)
248                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
249         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
250                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
251
252         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
253                 struct ip6_flowlabel *flowlabel;
254
255                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
256                 if (!flowlabel)
257                         goto out;
258                 fl6_sock_release(flowlabel);
259         }
260
261         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
262
263         if (asoc)
264                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
265
266         if (saddr) {
267                 fl6->saddr = saddr->v6.sin6_addr;
268                 if (!fl6->fl6_sport)
269                         fl6->fl6_sport = saddr->v6.sin6_port;
270
271                 pr_debug("src=%pI6 - ", &fl6->saddr);
272         }
273
274         rcu_read_lock();
275         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
276         rcu_read_unlock();
277
278         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
279         if (!asoc || saddr)
280                 goto out;
281
282         bp = &asoc->base.bind_addr;
283         scope = sctp_scope(daddr);
284         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
285          * to see if we can use it.
286          */
287         if (!IS_ERR(dst)) {
288                 /* Walk through the bind address list and look for a bind
289                  * address that matches the source address of the returned dst.
290                  */
291                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
292                 rcu_read_lock();
293                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
294                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
295                             (laddr->state != SCTP_ADDR_SRC &&
296                              !asoc->src_out_of_asoc_ok))
297                                 continue;
298
299                         /* Do not compare against v4 addrs */
300                         if ((laddr->a.sa.sa_family == AF_INET6) &&
301                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
302                                 rcu_read_unlock();
303                                 goto out;
304                         }
305                 }
306                 rcu_read_unlock();
307                 /* None of the bound addresses match the source address of the
308                  * dst. So release it.
309                  */
310                 dst_release(dst);
311                 dst = NULL;
312         }
313
314         /* Walk through the bind address list and try to get the
315          * best source address for a given destination.
316          */
317         rcu_read_lock();
318         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
319                 struct dst_entry *bdst;
320                 __u8 bmatchlen;
321
322                 if (!laddr->valid ||
323                     laddr->state != SCTP_ADDR_SRC ||
324                     laddr->a.sa.sa_family != AF_INET6 ||
325                     scope > sctp_scope(&laddr->a))
326                         continue;
327
328                 fl6->saddr = laddr->a.v6.sin6_addr;
329                 fl6->fl6_sport = laddr->a.v6.sin6_port;
330                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
331                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
332
333                 if (IS_ERR(bdst))
334                         continue;
335
336                 if (ipv6_chk_addr(dev_net(bdst->dev),
337                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
338                         if (!IS_ERR_OR_NULL(dst))
339                                 dst_release(dst);
340                         dst = bdst;
341                         break;
342                 }
343
344                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
345                 if (matchlen > bmatchlen) {
346                         dst_release(bdst);
347                         continue;
348                 }
349
350                 if (!IS_ERR_OR_NULL(dst))
351                         dst_release(dst);
352                 dst = bdst;
353                 matchlen = bmatchlen;
354         }
355         rcu_read_unlock();
356
357 out:
358         if (!IS_ERR_OR_NULL(dst)) {
359                 struct rt6_info *rt;
360
361                 rt = (struct rt6_info *)dst;
362                 t->dst = dst;
363                 t->dst_cookie = rt6_get_cookie(rt);
364                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
365                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
366                          &fl6->saddr);
367         } else {
368                 t->dst = NULL;
369
370                 pr_debug("no route\n");
371         }
372 }
373
374 /* Returns the number of consecutive initial bits that match in the 2 ipv6
375  * addresses.
376  */
377 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
378                                          union sctp_addr *s2)
379 {
380         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
381 }
382
383 /* Fills in the source address(saddr) based on the destination address(daddr)
384  * and asoc's bind address list.
385  */
386 static void sctp_v6_get_saddr(struct sctp_sock *sk,
387                               struct sctp_transport *t,
388                               struct flowi *fl)
389 {
390         struct flowi6 *fl6 = &fl->u.ip6;
391         union sctp_addr *saddr = &t->saddr;
392
393         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
394
395         if (t->dst) {
396                 saddr->v6.sin6_family = AF_INET6;
397                 saddr->v6.sin6_addr = fl6->saddr;
398         }
399 }
400
401 /* Make a copy of all potential local addresses. */
402 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
403                                   struct net_device *dev)
404 {
405         struct inet6_dev *in6_dev;
406         struct inet6_ifaddr *ifp;
407         struct sctp_sockaddr_entry *addr;
408
409         rcu_read_lock();
410         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
411                 rcu_read_unlock();
412                 return;
413         }
414
415         read_lock_bh(&in6_dev->lock);
416         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
417                 /* Add the address to the local list.  */
418                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
419                 if (addr) {
420                         addr->a.v6.sin6_family = AF_INET6;
421                         addr->a.v6.sin6_addr = ifp->addr;
422                         addr->a.v6.sin6_scope_id = dev->ifindex;
423                         addr->valid = 1;
424                         INIT_LIST_HEAD(&addr->list);
425                         list_add_tail(&addr->list, addrlist);
426                 }
427         }
428
429         read_unlock_bh(&in6_dev->lock);
430         rcu_read_unlock();
431 }
432
433 /* Copy over any ip options */
434 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
435 {
436         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
437         struct ipv6_txoptions *opt;
438
439         newnp = inet6_sk(newsk);
440
441         rcu_read_lock();
442         opt = rcu_dereference(np->opt);
443         if (opt) {
444                 opt = ipv6_dup_options(newsk, opt);
445                 if (!opt)
446                         pr_err("%s: Failed to copy ip options\n", __func__);
447         }
448         RCU_INIT_POINTER(newnp->opt, opt);
449         rcu_read_unlock();
450 }
451
452 /* Account for the IP options */
453 static int sctp_v6_ip_options_len(struct sock *sk)
454 {
455         struct ipv6_pinfo *np = inet6_sk(sk);
456         struct ipv6_txoptions *opt;
457         int len = 0;
458
459         rcu_read_lock();
460         opt = rcu_dereference(np->opt);
461         if (opt)
462                 len = opt->opt_flen + opt->opt_nflen;
463
464         rcu_read_unlock();
465         return len;
466 }
467
468 /* Initialize a sockaddr_storage from in incoming skb. */
469 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
470                              int is_saddr)
471 {
472         /* Always called on head skb, so this is safe */
473         struct sctphdr *sh = sctp_hdr(skb);
474         struct sockaddr_in6 *sa = &addr->v6;
475
476         addr->v6.sin6_family = AF_INET6;
477         addr->v6.sin6_flowinfo = 0; /* FIXME */
478         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
479
480         if (is_saddr) {
481                 sa->sin6_port = sh->source;
482                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
483         } else {
484                 sa->sin6_port = sh->dest;
485                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
486         }
487 }
488
489 /* Initialize an sctp_addr from a socket. */
490 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
491 {
492         addr->v6.sin6_family = AF_INET6;
493         addr->v6.sin6_port = 0;
494         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
495 }
496
497 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
498 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
499 {
500         if (addr->sa.sa_family == AF_INET) {
501                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
502                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
503                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
504                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
505                         addr->v4.sin_addr.s_addr;
506         } else {
507                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
508         }
509 }
510
511 /* Initialize sk->sk_daddr from sctp_addr. */
512 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
513 {
514         if (addr->sa.sa_family == AF_INET) {
515                 sk->sk_v6_daddr.s6_addr32[0] = 0;
516                 sk->sk_v6_daddr.s6_addr32[1] = 0;
517                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
518                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
519         } else {
520                 sk->sk_v6_daddr = addr->v6.sin6_addr;
521         }
522 }
523
524 /* Initialize a sctp_addr from an address parameter. */
525 static void sctp_v6_from_addr_param(union sctp_addr *addr,
526                                     union sctp_addr_param *param,
527                                     __be16 port, int iif)
528 {
529         addr->v6.sin6_family = AF_INET6;
530         addr->v6.sin6_port = port;
531         addr->v6.sin6_flowinfo = 0; /* BUG */
532         addr->v6.sin6_addr = param->v6.addr;
533         addr->v6.sin6_scope_id = iif;
534 }
535
536 /* Initialize an address parameter from a sctp_addr and return the length
537  * of the address parameter.
538  */
539 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
540                                  union sctp_addr_param *param)
541 {
542         int length = sizeof(struct sctp_ipv6addr_param);
543
544         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
545         param->v6.param_hdr.length = htons(length);
546         param->v6.addr = addr->v6.sin6_addr;
547
548         return length;
549 }
550
551 /* Initialize a sctp_addr from struct in6_addr. */
552 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
553                               __be16 port)
554 {
555         addr->sa.sa_family = AF_INET6;
556         addr->v6.sin6_port = port;
557         addr->v6.sin6_flowinfo = 0;
558         addr->v6.sin6_addr = *saddr;
559         addr->v6.sin6_scope_id = 0;
560 }
561
562 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
563                               const union sctp_addr *addr2)
564 {
565         if (addr1->sa.sa_family != addr2->sa.sa_family) {
566                 if (addr1->sa.sa_family == AF_INET &&
567                     addr2->sa.sa_family == AF_INET6 &&
568                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
569                     addr2->v6.sin6_addr.s6_addr32[3] ==
570                     addr1->v4.sin_addr.s_addr)
571                         return 1;
572
573                 if (addr2->sa.sa_family == AF_INET &&
574                     addr1->sa.sa_family == AF_INET6 &&
575                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
576                     addr1->v6.sin6_addr.s6_addr32[3] ==
577                     addr2->v4.sin_addr.s_addr)
578                         return 1;
579
580                 return 0;
581         }
582
583         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
584                 return 0;
585
586         /* If this is a linklocal address, compare the scope_id. */
587         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
588             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
589             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
590                 return 0;
591
592         return 1;
593 }
594
595 /* Compare addresses exactly.
596  * v4-mapped-v6 is also in consideration.
597  */
598 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
599                             const union sctp_addr *addr2)
600 {
601         return __sctp_v6_cmp_addr(addr1, addr2) &&
602                addr1->v6.sin6_port == addr2->v6.sin6_port;
603 }
604
605 /* Initialize addr struct to INADDR_ANY. */
606 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
607 {
608         memset(addr, 0x00, sizeof(union sctp_addr));
609         addr->v6.sin6_family = AF_INET6;
610         addr->v6.sin6_port = port;
611 }
612
613 /* Is this a wildcard address? */
614 static int sctp_v6_is_any(const union sctp_addr *addr)
615 {
616         return ipv6_addr_any(&addr->v6.sin6_addr);
617 }
618
619 /* Should this be available for binding?   */
620 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
621 {
622         int type;
623         struct net *net = sock_net(&sp->inet.sk);
624         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
625
626         type = ipv6_addr_type(in6);
627         if (IPV6_ADDR_ANY == type)
628                 return 1;
629         if (type == IPV6_ADDR_MAPPED) {
630                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
631                         return 0;
632                 sctp_v6_map_v4(addr);
633                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
634         }
635         if (!(type & IPV6_ADDR_UNICAST))
636                 return 0;
637
638         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
639                 ipv6_chk_addr(net, in6, NULL, 0);
640 }
641
642 /* This function checks if the address is a valid address to be used for
643  * SCTP.
644  *
645  * Output:
646  * Return 0 - If the address is a non-unicast or an illegal address.
647  * Return 1 - If the address is a unicast.
648  */
649 static int sctp_v6_addr_valid(union sctp_addr *addr,
650                               struct sctp_sock *sp,
651                               const struct sk_buff *skb)
652 {
653         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
654
655         /* Support v4-mapped-v6 address. */
656         if (ret == IPV6_ADDR_MAPPED) {
657                 /* Note: This routine is used in input, so v4-mapped-v6
658                  * are disallowed here when there is no sctp_sock.
659                  */
660                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
661                         return 0;
662                 sctp_v6_map_v4(addr);
663                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
664         }
665
666         /* Is this a non-unicast address */
667         if (!(ret & IPV6_ADDR_UNICAST))
668                 return 0;
669
670         return 1;
671 }
672
673 /* What is the scope of 'addr'?  */
674 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
675 {
676         enum sctp_scope retval;
677         int v6scope;
678
679         /* The IPv6 scope is really a set of bit fields.
680          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
681          */
682
683         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
684         switch (v6scope) {
685         case IFA_HOST:
686                 retval = SCTP_SCOPE_LOOPBACK;
687                 break;
688         case IFA_LINK:
689                 retval = SCTP_SCOPE_LINK;
690                 break;
691         case IFA_SITE:
692                 retval = SCTP_SCOPE_PRIVATE;
693                 break;
694         default:
695                 retval = SCTP_SCOPE_GLOBAL;
696                 break;
697         }
698
699         return retval;
700 }
701
702 /* Create and initialize a new sk for the socket to be returned by accept(). */
703 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
704                                              struct sctp_association *asoc,
705                                              bool kern)
706 {
707         struct sock *newsk;
708         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
709         struct sctp6_sock *newsctp6sk;
710
711         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
712         if (!newsk)
713                 goto out;
714
715         sock_init_data(NULL, newsk);
716
717         sctp_copy_sock(newsk, sk, asoc);
718         sock_reset_flag(sk, SOCK_ZAPPED);
719
720         newsctp6sk = (struct sctp6_sock *)newsk;
721         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
722
723         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
724
725         newnp = inet6_sk(newsk);
726
727         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
728         newnp->ipv6_mc_list = NULL;
729         newnp->ipv6_ac_list = NULL;
730         newnp->ipv6_fl_list = NULL;
731
732         sctp_v6_copy_ip_options(sk, newsk);
733
734         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
735          * and getpeername().
736          */
737         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
738
739         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
740
741         sk_refcnt_debug_inc(newsk);
742
743         if (newsk->sk_prot->init(newsk)) {
744                 sk_common_release(newsk);
745                 newsk = NULL;
746         }
747
748 out:
749         return newsk;
750 }
751
752 /* Format a sockaddr for return to user space. This makes sure the return is
753  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
754  */
755 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
756 {
757         if (sp->v4mapped) {
758                 if (addr->sa.sa_family == AF_INET)
759                         sctp_v4_map_v6(addr);
760         } else {
761                 if (addr->sa.sa_family == AF_INET6 &&
762                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
763                         sctp_v6_map_v4(addr);
764         }
765
766         if (addr->sa.sa_family == AF_INET) {
767                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
768                 return sizeof(struct sockaddr_in);
769         }
770         return sizeof(struct sockaddr_in6);
771 }
772
773 /* Where did this skb come from?  */
774 static int sctp_v6_skb_iif(const struct sk_buff *skb)
775 {
776         return IP6CB(skb)->iif;
777 }
778
779 /* Was this packet marked by Explicit Congestion Notification? */
780 static int sctp_v6_is_ce(const struct sk_buff *skb)
781 {
782         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
783 }
784
785 /* Dump the v6 addr to the seq file. */
786 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
787 {
788         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
789 }
790
791 static void sctp_v6_ecn_capable(struct sock *sk)
792 {
793         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
794 }
795
796 /* Initialize a PF_INET msgname from a ulpevent. */
797 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
798                                      char *msgname, int *addrlen)
799 {
800         union sctp_addr *addr;
801         struct sctp_association *asoc;
802         union sctp_addr *paddr;
803
804         if (!msgname)
805                 return;
806
807         addr = (union sctp_addr *)msgname;
808         asoc = event->asoc;
809         paddr = &asoc->peer.primary_addr;
810
811         if (paddr->sa.sa_family == AF_INET) {
812                 addr->v4.sin_family = AF_INET;
813                 addr->v4.sin_port = htons(asoc->peer.port);
814                 addr->v4.sin_addr = paddr->v4.sin_addr;
815         } else {
816                 addr->v6.sin6_family = AF_INET6;
817                 addr->v6.sin6_flowinfo = 0;
818                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
819                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
820                 else
821                         addr->v6.sin6_scope_id = 0;
822                 addr->v6.sin6_port = htons(asoc->peer.port);
823                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
824         }
825
826         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
827 }
828
829 /* Initialize a msg_name from an inbound skb. */
830 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
831                                    int *addr_len)
832 {
833         union sctp_addr *addr;
834         struct sctphdr *sh;
835
836         if (!msgname)
837                 return;
838
839         addr = (union sctp_addr *)msgname;
840         sh = sctp_hdr(skb);
841
842         if (ip_hdr(skb)->version == 4) {
843                 addr->v4.sin_family = AF_INET;
844                 addr->v4.sin_port = sh->source;
845                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
846         } else {
847                 addr->v6.sin6_family = AF_INET6;
848                 addr->v6.sin6_flowinfo = 0;
849                 addr->v6.sin6_port = sh->source;
850                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
851                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
852                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
853                 else
854                         addr->v6.sin6_scope_id = 0;
855         }
856
857         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
858 }
859
860 /* Do we support this AF? */
861 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
862 {
863         switch (family) {
864         case AF_INET6:
865                 return 1;
866         /* v4-mapped-v6 addresses */
867         case AF_INET:
868                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
869                         return 1;
870                 /* fallthru */
871         default:
872                 return 0;
873         }
874 }
875
876 /* Address matching with wildcards allowed.  This extra level
877  * of indirection lets us choose whether a PF_INET6 should
878  * disallow any v4 addresses if we so choose.
879  */
880 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
881                                const union sctp_addr *addr2,
882                                struct sctp_sock *opt)
883 {
884         struct sock *sk = sctp_opt2sk(opt);
885         struct sctp_af *af1, *af2;
886
887         af1 = sctp_get_af_specific(addr1->sa.sa_family);
888         af2 = sctp_get_af_specific(addr2->sa.sa_family);
889
890         if (!af1 || !af2)
891                 return 0;
892
893         /* If the socket is IPv6 only, v4 addrs will not match */
894         if (__ipv6_only_sock(sk) && af1 != af2)
895                 return 0;
896
897         /* Today, wildcard AF_INET/AF_INET6. */
898         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
899                 return 1;
900
901         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
902                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
903
904         return __sctp_v6_cmp_addr(addr1, addr2);
905 }
906
907 /* Verify that the provided sockaddr looks bindable.   Common verification,
908  * has already been taken care of.
909  */
910 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
911 {
912         struct sctp_af *af;
913
914         /* ASSERT: address family has already been verified. */
915         if (addr->sa.sa_family != AF_INET6)
916                 af = sctp_get_af_specific(addr->sa.sa_family);
917         else {
918                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
919                 struct net_device *dev;
920
921                 if (type & IPV6_ADDR_LINKLOCAL) {
922                         struct net *net;
923                         if (!addr->v6.sin6_scope_id)
924                                 return 0;
925                         net = sock_net(&opt->inet.sk);
926                         rcu_read_lock();
927                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
928                         if (!dev || !(opt->inet.freebind ||
929                                       net->ipv6.sysctl.ip_nonlocal_bind ||
930                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
931                                                     dev, 0))) {
932                                 rcu_read_unlock();
933                                 return 0;
934                         }
935                         rcu_read_unlock();
936                 }
937
938                 af = opt->pf->af;
939         }
940         return af->available(addr, opt);
941 }
942
943 /* Verify that the provided sockaddr looks sendable.   Common verification,
944  * has already been taken care of.
945  */
946 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
947 {
948         struct sctp_af *af = NULL;
949
950         /* ASSERT: address family has already been verified. */
951         if (addr->sa.sa_family != AF_INET6)
952                 af = sctp_get_af_specific(addr->sa.sa_family);
953         else {
954                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
955                 struct net_device *dev;
956
957                 if (type & IPV6_ADDR_LINKLOCAL) {
958                         if (!addr->v6.sin6_scope_id)
959                                 return 0;
960                         rcu_read_lock();
961                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
962                                                    addr->v6.sin6_scope_id);
963                         rcu_read_unlock();
964                         if (!dev)
965                                 return 0;
966                 }
967                 af = opt->pf->af;
968         }
969
970         return af != NULL;
971 }
972
973 /* Fill in Supported Address Type information for INIT and INIT-ACK
974  * chunks.   Note: In the future, we may want to look at sock options
975  * to determine whether a PF_INET6 socket really wants to have IPV4
976  * addresses.
977  * Returns number of addresses supported.
978  */
979 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
980                                       __be16 *types)
981 {
982         types[0] = SCTP_PARAM_IPV6_ADDRESS;
983         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
984                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
985                 return 2;
986         }
987         return 1;
988 }
989
990 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
991 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
992                         int peer)
993 {
994         int rc;
995
996         rc = inet6_getname(sock, uaddr, peer);
997
998         if (rc < 0)
999                 return rc;
1000
1001         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1002                                           (union sctp_addr *)uaddr);
1003
1004         return rc;
1005 }
1006
1007 static const struct proto_ops inet6_seqpacket_ops = {
1008         .family            = PF_INET6,
1009         .owner             = THIS_MODULE,
1010         .release           = inet6_release,
1011         .bind              = inet6_bind,
1012         .connect           = sctp_inet_connect,
1013         .socketpair        = sock_no_socketpair,
1014         .accept            = inet_accept,
1015         .getname           = sctp_getname,
1016         .poll              = sctp_poll,
1017         .ioctl             = inet6_ioctl,
1018         .gettstamp         = sock_gettstamp,
1019         .listen            = sctp_inet_listen,
1020         .shutdown          = inet_shutdown,
1021         .setsockopt        = sock_common_setsockopt,
1022         .getsockopt        = sock_common_getsockopt,
1023         .sendmsg           = inet_sendmsg,
1024         .recvmsg           = inet_recvmsg,
1025         .mmap              = sock_no_mmap,
1026 #ifdef CONFIG_COMPAT
1027         .compat_setsockopt = compat_sock_common_setsockopt,
1028         .compat_getsockopt = compat_sock_common_getsockopt,
1029 #endif
1030 };
1031
1032 static struct inet_protosw sctpv6_seqpacket_protosw = {
1033         .type          = SOCK_SEQPACKET,
1034         .protocol      = IPPROTO_SCTP,
1035         .prot          = &sctpv6_prot,
1036         .ops           = &inet6_seqpacket_ops,
1037         .flags         = SCTP_PROTOSW_FLAG
1038 };
1039 static struct inet_protosw sctpv6_stream_protosw = {
1040         .type          = SOCK_STREAM,
1041         .protocol      = IPPROTO_SCTP,
1042         .prot          = &sctpv6_prot,
1043         .ops           = &inet6_seqpacket_ops,
1044         .flags         = SCTP_PROTOSW_FLAG,
1045 };
1046
1047 static int sctp6_rcv(struct sk_buff *skb)
1048 {
1049         return sctp_rcv(skb) ? -1 : 0;
1050 }
1051
1052 static const struct inet6_protocol sctpv6_protocol = {
1053         .handler      = sctp6_rcv,
1054         .err_handler  = sctp_v6_err,
1055         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1056 };
1057
1058 static struct sctp_af sctp_af_inet6 = {
1059         .sa_family         = AF_INET6,
1060         .sctp_xmit         = sctp_v6_xmit,
1061         .setsockopt        = ipv6_setsockopt,
1062         .getsockopt        = ipv6_getsockopt,
1063         .get_dst           = sctp_v6_get_dst,
1064         .get_saddr         = sctp_v6_get_saddr,
1065         .copy_addrlist     = sctp_v6_copy_addrlist,
1066         .from_skb          = sctp_v6_from_skb,
1067         .from_sk           = sctp_v6_from_sk,
1068         .from_addr_param   = sctp_v6_from_addr_param,
1069         .to_addr_param     = sctp_v6_to_addr_param,
1070         .cmp_addr          = sctp_v6_cmp_addr,
1071         .scope             = sctp_v6_scope,
1072         .addr_valid        = sctp_v6_addr_valid,
1073         .inaddr_any        = sctp_v6_inaddr_any,
1074         .is_any            = sctp_v6_is_any,
1075         .available         = sctp_v6_available,
1076         .skb_iif           = sctp_v6_skb_iif,
1077         .is_ce             = sctp_v6_is_ce,
1078         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1079         .ecn_capable       = sctp_v6_ecn_capable,
1080         .net_header_len    = sizeof(struct ipv6hdr),
1081         .sockaddr_len      = sizeof(struct sockaddr_in6),
1082         .ip_options_len    = sctp_v6_ip_options_len,
1083 #ifdef CONFIG_COMPAT
1084         .compat_setsockopt = compat_ipv6_setsockopt,
1085         .compat_getsockopt = compat_ipv6_getsockopt,
1086 #endif
1087 };
1088
1089 static struct sctp_pf sctp_pf_inet6 = {
1090         .event_msgname = sctp_inet6_event_msgname,
1091         .skb_msgname   = sctp_inet6_skb_msgname,
1092         .af_supported  = sctp_inet6_af_supported,
1093         .cmp_addr      = sctp_inet6_cmp_addr,
1094         .bind_verify   = sctp_inet6_bind_verify,
1095         .send_verify   = sctp_inet6_send_verify,
1096         .supported_addrs = sctp_inet6_supported_addrs,
1097         .create_accept_sk = sctp_v6_create_accept_sk,
1098         .addr_to_user  = sctp_v6_addr_to_user,
1099         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1100         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1101         .copy_ip_options = sctp_v6_copy_ip_options,
1102         .af            = &sctp_af_inet6,
1103 };
1104
1105 /* Initialize IPv6 support and register with socket layer.  */
1106 void sctp_v6_pf_init(void)
1107 {
1108         /* Register the SCTP specific PF_INET6 functions. */
1109         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1110
1111         /* Register the SCTP specific AF_INET6 functions. */
1112         sctp_register_af(&sctp_af_inet6);
1113 }
1114
1115 void sctp_v6_pf_exit(void)
1116 {
1117         list_del(&sctp_af_inet6.list);
1118 }
1119
1120 /* Initialize IPv6 support and register with socket layer.  */
1121 int sctp_v6_protosw_init(void)
1122 {
1123         int rc;
1124
1125         rc = proto_register(&sctpv6_prot, 1);
1126         if (rc)
1127                 return rc;
1128
1129         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1130         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1131         inet6_register_protosw(&sctpv6_stream_protosw);
1132
1133         return 0;
1134 }
1135
1136 void sctp_v6_protosw_exit(void)
1137 {
1138         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1139         inet6_unregister_protosw(&sctpv6_stream_protosw);
1140         proto_unregister(&sctpv6_prot);
1141 }
1142
1143
1144 /* Register with inet6 layer. */
1145 int sctp_v6_add_protocol(void)
1146 {
1147         /* Register notifier for inet6 address additions/deletions. */
1148         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1149
1150         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1151                 return -EAGAIN;
1152
1153         return 0;
1154 }
1155
1156 /* Unregister with inet6 layer. */
1157 void sctp_v6_del_protocol(void)
1158 {
1159         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1160         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1161 }