sctp: fix dst refcnt leak in sctp_v6_get_dst()
[sfrench/cifs-2.6.git] / net / sctp / ipv6.c
1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2002, 2004
3  * Copyright (c) 2001 Nokia, Inc.
4  * Copyright (c) 2001 La Monte H.P. Yarroll
5  * Copyright (c) 2002-2003 Intel Corp.
6  *
7  * This file is part of the SCTP kernel implementation
8  *
9  * SCTP over IPv6.
10  *
11  * This SCTP implementation is free software;
12  * you can redistribute it and/or modify it under the terms of
13  * the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * This SCTP implementation is distributed in the hope that it
18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19  *                 ************************
20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21  * See the GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with GNU CC; see the file COPYING.  If not, see
25  * <http://www.gnu.org/licenses/>.
26  *
27  * Please send any bug reports or fixes you make to the
28  * email address(es):
29  *    lksctp developers <linux-sctp@vger.kernel.org>
30  *
31  * Written or modified by:
32  *    Le Yanqun             <yanqun.le@nokia.com>
33  *    Hui Huang             <hui.huang@nokia.com>
34  *    La Monte H.P. Yarroll <piggy@acm.org>
35  *    Sridhar Samudrala     <sri@us.ibm.com>
36  *    Jon Grimm             <jgrimm@us.ibm.com>
37  *    Ardelle Fan           <ardelle.fan@intel.com>
38  *
39  * Based on:
40  *      linux/net/ipv6/tcp_ipv6.c
41  */
42
43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44
45 #include <linux/module.h>
46 #include <linux/errno.h>
47 #include <linux/types.h>
48 #include <linux/socket.h>
49 #include <linux/sockios.h>
50 #include <linux/net.h>
51 #include <linux/in.h>
52 #include <linux/in6.h>
53 #include <linux/netdevice.h>
54 #include <linux/init.h>
55 #include <linux/ipsec.h>
56 #include <linux/slab.h>
57
58 #include <linux/ipv6.h>
59 #include <linux/icmpv6.h>
60 #include <linux/random.h>
61 #include <linux/seq_file.h>
62
63 #include <net/protocol.h>
64 #include <net/ndisc.h>
65 #include <net/ip.h>
66 #include <net/ipv6.h>
67 #include <net/transp_v6.h>
68 #include <net/addrconf.h>
69 #include <net/ip6_route.h>
70 #include <net/inet_common.h>
71 #include <net/inet_ecn.h>
72 #include <net/sctp/sctp.h>
73
74 #include <linux/uaccess.h>
75
76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
77                                          union sctp_addr *s2);
78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
79                               __be16 port);
80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
81                             const union sctp_addr *addr2);
82
83 /* Event handler for inet6 address addition/deletion events.
84  * The sctp_local_addr_list needs to be protocted by a spin lock since
85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
86  * time and thus corrupt the list.
87  * The reader side is protected with RCU.
88  */
89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
90                                 void *ptr)
91 {
92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
93         struct sctp_sockaddr_entry *addr = NULL;
94         struct sctp_sockaddr_entry *temp;
95         struct net *net = dev_net(ifa->idev->dev);
96         int found = 0;
97
98         switch (ev) {
99         case NETDEV_UP:
100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
101                 if (addr) {
102                         addr->a.v6.sin6_family = AF_INET6;
103                         addr->a.v6.sin6_port = 0;
104                         addr->a.v6.sin6_addr = ifa->addr;
105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
106                         addr->valid = 1;
107                         spin_lock_bh(&net->sctp.local_addr_lock);
108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
110                         spin_unlock_bh(&net->sctp.local_addr_lock);
111                 }
112                 break;
113         case NETDEV_DOWN:
114                 spin_lock_bh(&net->sctp.local_addr_lock);
115                 list_for_each_entry_safe(addr, temp,
116                                         &net->sctp.local_addr_list, list) {
117                         if (addr->a.sa.sa_family == AF_INET6 &&
118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
119                                                 &ifa->addr)) {
120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
121                                 found = 1;
122                                 addr->valid = 0;
123                                 list_del_rcu(&addr->list);
124                                 break;
125                         }
126                 }
127                 spin_unlock_bh(&net->sctp.local_addr_lock);
128                 if (found)
129                         kfree_rcu(addr, rcu);
130                 break;
131         }
132
133         return NOTIFY_DONE;
134 }
135
136 static struct notifier_block sctp_inet6addr_notifier = {
137         .notifier_call = sctp_inet6addr_event,
138 };
139
140 /* ICMP error handler. */
141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
142                         u8 type, u8 code, int offset, __be32 info)
143 {
144         struct inet6_dev *idev;
145         struct sock *sk;
146         struct sctp_association *asoc;
147         struct sctp_transport *transport;
148         struct ipv6_pinfo *np;
149         __u16 saveip, savesctp;
150         int err;
151         struct net *net = dev_net(skb->dev);
152
153         idev = in6_dev_get(skb->dev);
154
155         /* Fix up skb to look at the embedded net header. */
156         saveip   = skb->network_header;
157         savesctp = skb->transport_header;
158         skb_reset_network_header(skb);
159         skb_set_transport_header(skb, offset);
160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
161         /* Put back, the original pointers. */
162         skb->network_header   = saveip;
163         skb->transport_header = savesctp;
164         if (!sk) {
165                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
166                 goto out;
167         }
168
169         /* Warning:  The sock lock is held.  Remember to call
170          * sctp_err_finish!
171          */
172
173         switch (type) {
174         case ICMPV6_PKT_TOOBIG:
175                 if (ip6_sk_accept_pmtu(sk))
176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
177                 goto out_unlock;
178         case ICMPV6_PARAMPROB:
179                 if (ICMPV6_UNK_NEXTHDR == code) {
180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
181                         goto out_unlock;
182                 }
183                 break;
184         case NDISC_REDIRECT:
185                 sctp_icmp_redirect(sk, transport, skb);
186                 goto out_unlock;
187         default:
188                 break;
189         }
190
191         np = inet6_sk(sk);
192         icmpv6_err_convert(type, code, &err);
193         if (!sock_owned_by_user(sk) && np->recverr) {
194                 sk->sk_err = err;
195                 sk->sk_error_report(sk);
196         } else {  /* Only an error on timeout */
197                 sk->sk_err_soft = err;
198         }
199
200 out_unlock:
201         sctp_err_finish(sk, transport);
202 out:
203         if (likely(idev != NULL))
204                 in6_dev_put(idev);
205 }
206
207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
208 {
209         struct sock *sk = skb->sk;
210         struct ipv6_pinfo *np = inet6_sk(sk);
211         struct flowi6 *fl6 = &transport->fl.u.ip6;
212         int res;
213
214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
215                  skb->len, &fl6->saddr, &fl6->daddr);
216
217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
218
219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
220                 skb->ignore_df = 1;
221
222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
223
224         rcu_read_lock();
225         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
226                        np->tclass);
227         rcu_read_unlock();
228         return res;
229 }
230
231 /* Returns the dst cache entry for the given source and destination ip
232  * addresses.
233  */
234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
235                             struct flowi *fl, struct sock *sk)
236 {
237         struct sctp_association *asoc = t->asoc;
238         struct dst_entry *dst = NULL;
239         struct flowi6 *fl6 = &fl->u.ip6;
240         struct sctp_bind_addr *bp;
241         struct ipv6_pinfo *np = inet6_sk(sk);
242         struct sctp_sockaddr_entry *laddr;
243         union sctp_addr *daddr = &t->ipaddr;
244         union sctp_addr dst_saddr;
245         struct in6_addr *final_p, final;
246         enum sctp_scope scope;
247         __u8 matchlen = 0;
248
249         memset(fl6, 0, sizeof(struct flowi6));
250         fl6->daddr = daddr->v6.sin6_addr;
251         fl6->fl6_dport = daddr->v6.sin6_port;
252         fl6->flowi6_proto = IPPROTO_SCTP;
253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
255         else if (asoc)
256                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
257
258         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
259
260         if (asoc)
261                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
262
263         if (saddr) {
264                 fl6->saddr = saddr->v6.sin6_addr;
265                 fl6->fl6_sport = saddr->v6.sin6_port;
266
267                 pr_debug("src=%pI6 - ", &fl6->saddr);
268         }
269
270         rcu_read_lock();
271         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
272         rcu_read_unlock();
273
274         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
275         if (!asoc || saddr)
276                 goto out;
277
278         bp = &asoc->base.bind_addr;
279         scope = sctp_scope(daddr);
280         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
281          * to see if we can use it.
282          */
283         if (!IS_ERR(dst)) {
284                 /* Walk through the bind address list and look for a bind
285                  * address that matches the source address of the returned dst.
286                  */
287                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
288                 rcu_read_lock();
289                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
290                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
291                             (laddr->state != SCTP_ADDR_SRC &&
292                              !asoc->src_out_of_asoc_ok))
293                                 continue;
294
295                         /* Do not compare against v4 addrs */
296                         if ((laddr->a.sa.sa_family == AF_INET6) &&
297                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
298                                 rcu_read_unlock();
299                                 goto out;
300                         }
301                 }
302                 rcu_read_unlock();
303                 /* None of the bound addresses match the source address of the
304                  * dst. So release it.
305                  */
306                 dst_release(dst);
307                 dst = NULL;
308         }
309
310         /* Walk through the bind address list and try to get the
311          * best source address for a given destination.
312          */
313         rcu_read_lock();
314         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
315                 struct dst_entry *bdst;
316                 __u8 bmatchlen;
317
318                 if (!laddr->valid ||
319                     laddr->state != SCTP_ADDR_SRC ||
320                     laddr->a.sa.sa_family != AF_INET6 ||
321                     scope > sctp_scope(&laddr->a))
322                         continue;
323
324                 fl6->saddr = laddr->a.v6.sin6_addr;
325                 fl6->fl6_sport = laddr->a.v6.sin6_port;
326                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
327                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
328
329                 if (IS_ERR(bdst))
330                         continue;
331
332                 if (ipv6_chk_addr(dev_net(bdst->dev),
333                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
334                         if (!IS_ERR_OR_NULL(dst))
335                                 dst_release(dst);
336                         dst = bdst;
337                         break;
338                 }
339
340                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
341                 if (matchlen > bmatchlen) {
342                         dst_release(bdst);
343                         continue;
344                 }
345
346                 if (!IS_ERR_OR_NULL(dst))
347                         dst_release(dst);
348                 dst = bdst;
349                 matchlen = bmatchlen;
350         }
351         rcu_read_unlock();
352
353 out:
354         if (!IS_ERR_OR_NULL(dst)) {
355                 struct rt6_info *rt;
356
357                 rt = (struct rt6_info *)dst;
358                 t->dst = dst;
359                 t->dst_cookie = rt6_get_cookie(rt);
360                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
361                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
362                          &fl6->saddr);
363         } else {
364                 t->dst = NULL;
365
366                 pr_debug("no route\n");
367         }
368 }
369
370 /* Returns the number of consecutive initial bits that match in the 2 ipv6
371  * addresses.
372  */
373 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
374                                          union sctp_addr *s2)
375 {
376         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
377 }
378
379 /* Fills in the source address(saddr) based on the destination address(daddr)
380  * and asoc's bind address list.
381  */
382 static void sctp_v6_get_saddr(struct sctp_sock *sk,
383                               struct sctp_transport *t,
384                               struct flowi *fl)
385 {
386         struct flowi6 *fl6 = &fl->u.ip6;
387         union sctp_addr *saddr = &t->saddr;
388
389         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
390
391         if (t->dst) {
392                 saddr->v6.sin6_family = AF_INET6;
393                 saddr->v6.sin6_addr = fl6->saddr;
394         }
395 }
396
397 /* Make a copy of all potential local addresses. */
398 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
399                                   struct net_device *dev)
400 {
401         struct inet6_dev *in6_dev;
402         struct inet6_ifaddr *ifp;
403         struct sctp_sockaddr_entry *addr;
404
405         rcu_read_lock();
406         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
407                 rcu_read_unlock();
408                 return;
409         }
410
411         read_lock_bh(&in6_dev->lock);
412         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
413                 /* Add the address to the local list.  */
414                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
415                 if (addr) {
416                         addr->a.v6.sin6_family = AF_INET6;
417                         addr->a.v6.sin6_port = 0;
418                         addr->a.v6.sin6_addr = ifp->addr;
419                         addr->a.v6.sin6_scope_id = dev->ifindex;
420                         addr->valid = 1;
421                         INIT_LIST_HEAD(&addr->list);
422                         list_add_tail(&addr->list, addrlist);
423                 }
424         }
425
426         read_unlock_bh(&in6_dev->lock);
427         rcu_read_unlock();
428 }
429
430 /* Initialize a sockaddr_storage from in incoming skb. */
431 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
432                              int is_saddr)
433 {
434         /* Always called on head skb, so this is safe */
435         struct sctphdr *sh = sctp_hdr(skb);
436         struct sockaddr_in6 *sa = &addr->v6;
437
438         addr->v6.sin6_family = AF_INET6;
439         addr->v6.sin6_flowinfo = 0; /* FIXME */
440         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
441
442         if (is_saddr) {
443                 sa->sin6_port = sh->source;
444                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
445         } else {
446                 sa->sin6_port = sh->dest;
447                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
448         }
449 }
450
451 /* Initialize an sctp_addr from a socket. */
452 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
453 {
454         addr->v6.sin6_family = AF_INET6;
455         addr->v6.sin6_port = 0;
456         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
457 }
458
459 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
460 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
461 {
462         if (addr->sa.sa_family == AF_INET) {
463                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
464                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
465                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
466                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
467                         addr->v4.sin_addr.s_addr;
468         } else {
469                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
470         }
471 }
472
473 /* Initialize sk->sk_daddr from sctp_addr. */
474 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
475 {
476         if (addr->sa.sa_family == AF_INET) {
477                 sk->sk_v6_daddr.s6_addr32[0] = 0;
478                 sk->sk_v6_daddr.s6_addr32[1] = 0;
479                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
480                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
481         } else {
482                 sk->sk_v6_daddr = addr->v6.sin6_addr;
483         }
484 }
485
486 /* Initialize a sctp_addr from an address parameter. */
487 static void sctp_v6_from_addr_param(union sctp_addr *addr,
488                                     union sctp_addr_param *param,
489                                     __be16 port, int iif)
490 {
491         addr->v6.sin6_family = AF_INET6;
492         addr->v6.sin6_port = port;
493         addr->v6.sin6_flowinfo = 0; /* BUG */
494         addr->v6.sin6_addr = param->v6.addr;
495         addr->v6.sin6_scope_id = iif;
496 }
497
498 /* Initialize an address parameter from a sctp_addr and return the length
499  * of the address parameter.
500  */
501 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
502                                  union sctp_addr_param *param)
503 {
504         int length = sizeof(struct sctp_ipv6addr_param);
505
506         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
507         param->v6.param_hdr.length = htons(length);
508         param->v6.addr = addr->v6.sin6_addr;
509
510         return length;
511 }
512
513 /* Initialize a sctp_addr from struct in6_addr. */
514 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
515                               __be16 port)
516 {
517         addr->sa.sa_family = AF_INET6;
518         addr->v6.sin6_port = port;
519         addr->v6.sin6_flowinfo = 0;
520         addr->v6.sin6_addr = *saddr;
521         addr->v6.sin6_scope_id = 0;
522 }
523
524 /* Compare addresses exactly.
525  * v4-mapped-v6 is also in consideration.
526  */
527 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
528                             const union sctp_addr *addr2)
529 {
530         if (addr1->sa.sa_family != addr2->sa.sa_family) {
531                 if (addr1->sa.sa_family == AF_INET &&
532                     addr2->sa.sa_family == AF_INET6 &&
533                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
534                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
535                             addr2->v6.sin6_addr.s6_addr32[3] ==
536                             addr1->v4.sin_addr.s_addr)
537                                 return 1;
538                 }
539                 if (addr2->sa.sa_family == AF_INET &&
540                     addr1->sa.sa_family == AF_INET6 &&
541                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
542                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
543                             addr1->v6.sin6_addr.s6_addr32[3] ==
544                             addr2->v4.sin_addr.s_addr)
545                                 return 1;
546                 }
547                 return 0;
548         }
549         if (addr1->v6.sin6_port != addr2->v6.sin6_port)
550                 return 0;
551         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
552                 return 0;
553         /* If this is a linklocal address, compare the scope_id. */
554         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
555                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
556                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
557                         return 0;
558                 }
559         }
560
561         return 1;
562 }
563
564 /* Initialize addr struct to INADDR_ANY. */
565 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
566 {
567         memset(addr, 0x00, sizeof(union sctp_addr));
568         addr->v6.sin6_family = AF_INET6;
569         addr->v6.sin6_port = port;
570 }
571
572 /* Is this a wildcard address? */
573 static int sctp_v6_is_any(const union sctp_addr *addr)
574 {
575         return ipv6_addr_any(&addr->v6.sin6_addr);
576 }
577
578 /* Should this be available for binding?   */
579 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
580 {
581         int type;
582         struct net *net = sock_net(&sp->inet.sk);
583         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
584
585         type = ipv6_addr_type(in6);
586         if (IPV6_ADDR_ANY == type)
587                 return 1;
588         if (type == IPV6_ADDR_MAPPED) {
589                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
590                         return 0;
591                 sctp_v6_map_v4(addr);
592                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
593         }
594         if (!(type & IPV6_ADDR_UNICAST))
595                 return 0;
596
597         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
598                 ipv6_chk_addr(net, in6, NULL, 0);
599 }
600
601 /* This function checks if the address is a valid address to be used for
602  * SCTP.
603  *
604  * Output:
605  * Return 0 - If the address is a non-unicast or an illegal address.
606  * Return 1 - If the address is a unicast.
607  */
608 static int sctp_v6_addr_valid(union sctp_addr *addr,
609                               struct sctp_sock *sp,
610                               const struct sk_buff *skb)
611 {
612         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
613
614         /* Support v4-mapped-v6 address. */
615         if (ret == IPV6_ADDR_MAPPED) {
616                 /* Note: This routine is used in input, so v4-mapped-v6
617                  * are disallowed here when there is no sctp_sock.
618                  */
619                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
620                         return 0;
621                 sctp_v6_map_v4(addr);
622                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
623         }
624
625         /* Is this a non-unicast address */
626         if (!(ret & IPV6_ADDR_UNICAST))
627                 return 0;
628
629         return 1;
630 }
631
632 /* What is the scope of 'addr'?  */
633 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
634 {
635         enum sctp_scope retval;
636         int v6scope;
637
638         /* The IPv6 scope is really a set of bit fields.
639          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
640          */
641
642         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
643         switch (v6scope) {
644         case IFA_HOST:
645                 retval = SCTP_SCOPE_LOOPBACK;
646                 break;
647         case IFA_LINK:
648                 retval = SCTP_SCOPE_LINK;
649                 break;
650         case IFA_SITE:
651                 retval = SCTP_SCOPE_PRIVATE;
652                 break;
653         default:
654                 retval = SCTP_SCOPE_GLOBAL;
655                 break;
656         }
657
658         return retval;
659 }
660
661 /* Create and initialize a new sk for the socket to be returned by accept(). */
662 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
663                                              struct sctp_association *asoc,
664                                              bool kern)
665 {
666         struct sock *newsk;
667         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
668         struct sctp6_sock *newsctp6sk;
669         struct ipv6_txoptions *opt;
670
671         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
672         if (!newsk)
673                 goto out;
674
675         sock_init_data(NULL, newsk);
676
677         sctp_copy_sock(newsk, sk, asoc);
678         sock_reset_flag(sk, SOCK_ZAPPED);
679
680         newsctp6sk = (struct sctp6_sock *)newsk;
681         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
682
683         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
684
685         newnp = inet6_sk(newsk);
686
687         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
688         newnp->ipv6_mc_list = NULL;
689         newnp->ipv6_ac_list = NULL;
690         newnp->ipv6_fl_list = NULL;
691
692         rcu_read_lock();
693         opt = rcu_dereference(np->opt);
694         if (opt)
695                 opt = ipv6_dup_options(newsk, opt);
696         RCU_INIT_POINTER(newnp->opt, opt);
697         rcu_read_unlock();
698
699         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
700          * and getpeername().
701          */
702         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
703
704         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
705
706         sk_refcnt_debug_inc(newsk);
707
708         if (newsk->sk_prot->init(newsk)) {
709                 sk_common_release(newsk);
710                 newsk = NULL;
711         }
712
713 out:
714         return newsk;
715 }
716
717 /* Format a sockaddr for return to user space. This makes sure the return is
718  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
719  */
720 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
721 {
722         if (sp->v4mapped) {
723                 if (addr->sa.sa_family == AF_INET)
724                         sctp_v4_map_v6(addr);
725         } else {
726                 if (addr->sa.sa_family == AF_INET6 &&
727                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
728                         sctp_v6_map_v4(addr);
729         }
730
731         if (addr->sa.sa_family == AF_INET)
732                 return sizeof(struct sockaddr_in);
733         return sizeof(struct sockaddr_in6);
734 }
735
736 /* Where did this skb come from?  */
737 static int sctp_v6_skb_iif(const struct sk_buff *skb)
738 {
739         return IP6CB(skb)->iif;
740 }
741
742 /* Was this packet marked by Explicit Congestion Notification? */
743 static int sctp_v6_is_ce(const struct sk_buff *skb)
744 {
745         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
746 }
747
748 /* Dump the v6 addr to the seq file. */
749 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
750 {
751         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
752 }
753
754 static void sctp_v6_ecn_capable(struct sock *sk)
755 {
756         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
757 }
758
759 /* Initialize a PF_INET msgname from a ulpevent. */
760 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
761                                      char *msgname, int *addrlen)
762 {
763         union sctp_addr *addr;
764         struct sctp_association *asoc;
765         union sctp_addr *paddr;
766
767         if (!msgname)
768                 return;
769
770         addr = (union sctp_addr *)msgname;
771         asoc = event->asoc;
772         paddr = &asoc->peer.primary_addr;
773
774         if (paddr->sa.sa_family == AF_INET) {
775                 addr->v4.sin_family = AF_INET;
776                 addr->v4.sin_port = htons(asoc->peer.port);
777                 addr->v4.sin_addr = paddr->v4.sin_addr;
778         } else {
779                 addr->v6.sin6_family = AF_INET6;
780                 addr->v6.sin6_flowinfo = 0;
781                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
782                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
783                 else
784                         addr->v6.sin6_scope_id = 0;
785                 addr->v6.sin6_port = htons(asoc->peer.port);
786                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
787         }
788
789         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
790 }
791
792 /* Initialize a msg_name from an inbound skb. */
793 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
794                                    int *addr_len)
795 {
796         union sctp_addr *addr;
797         struct sctphdr *sh;
798
799         if (!msgname)
800                 return;
801
802         addr = (union sctp_addr *)msgname;
803         sh = sctp_hdr(skb);
804
805         if (ip_hdr(skb)->version == 4) {
806                 addr->v4.sin_family = AF_INET;
807                 addr->v4.sin_port = sh->source;
808                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
809         } else {
810                 addr->v6.sin6_family = AF_INET6;
811                 addr->v6.sin6_flowinfo = 0;
812                 addr->v6.sin6_port = sh->source;
813                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
814                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
815                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
816                 else
817                         addr->v6.sin6_scope_id = 0;
818         }
819
820         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
821 }
822
823 /* Do we support this AF? */
824 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
825 {
826         switch (family) {
827         case AF_INET6:
828                 return 1;
829         /* v4-mapped-v6 addresses */
830         case AF_INET:
831                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
832                         return 1;
833                 /* fallthru */
834         default:
835                 return 0;
836         }
837 }
838
839 /* Address matching with wildcards allowed.  This extra level
840  * of indirection lets us choose whether a PF_INET6 should
841  * disallow any v4 addresses if we so choose.
842  */
843 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
844                                const union sctp_addr *addr2,
845                                struct sctp_sock *opt)
846 {
847         struct sctp_af *af1, *af2;
848         struct sock *sk = sctp_opt2sk(opt);
849
850         af1 = sctp_get_af_specific(addr1->sa.sa_family);
851         af2 = sctp_get_af_specific(addr2->sa.sa_family);
852
853         if (!af1 || !af2)
854                 return 0;
855
856         /* If the socket is IPv6 only, v4 addrs will not match */
857         if (__ipv6_only_sock(sk) && af1 != af2)
858                 return 0;
859
860         /* Today, wildcard AF_INET/AF_INET6. */
861         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
862                 return 1;
863
864         if (addr1->sa.sa_family != addr2->sa.sa_family)
865                 return 0;
866
867         return af1->cmp_addr(addr1, addr2);
868 }
869
870 /* Verify that the provided sockaddr looks bindable.   Common verification,
871  * has already been taken care of.
872  */
873 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
874 {
875         struct sctp_af *af;
876
877         /* ASSERT: address family has already been verified. */
878         if (addr->sa.sa_family != AF_INET6)
879                 af = sctp_get_af_specific(addr->sa.sa_family);
880         else {
881                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
882                 struct net_device *dev;
883
884                 if (type & IPV6_ADDR_LINKLOCAL) {
885                         struct net *net;
886                         if (!addr->v6.sin6_scope_id)
887                                 return 0;
888                         net = sock_net(&opt->inet.sk);
889                         rcu_read_lock();
890                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
891                         if (!dev || !(opt->inet.freebind ||
892                                       net->ipv6.sysctl.ip_nonlocal_bind ||
893                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
894                                                     dev, 0))) {
895                                 rcu_read_unlock();
896                                 return 0;
897                         }
898                         rcu_read_unlock();
899                 }
900
901                 af = opt->pf->af;
902         }
903         return af->available(addr, opt);
904 }
905
906 /* Verify that the provided sockaddr looks sendable.   Common verification,
907  * has already been taken care of.
908  */
909 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
910 {
911         struct sctp_af *af = NULL;
912
913         /* ASSERT: address family has already been verified. */
914         if (addr->sa.sa_family != AF_INET6)
915                 af = sctp_get_af_specific(addr->sa.sa_family);
916         else {
917                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
918                 struct net_device *dev;
919
920                 if (type & IPV6_ADDR_LINKLOCAL) {
921                         if (!addr->v6.sin6_scope_id)
922                                 return 0;
923                         rcu_read_lock();
924                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
925                                                    addr->v6.sin6_scope_id);
926                         rcu_read_unlock();
927                         if (!dev)
928                                 return 0;
929                 }
930                 af = opt->pf->af;
931         }
932
933         return af != NULL;
934 }
935
936 /* Fill in Supported Address Type information for INIT and INIT-ACK
937  * chunks.   Note: In the future, we may want to look at sock options
938  * to determine whether a PF_INET6 socket really wants to have IPV4
939  * addresses.
940  * Returns number of addresses supported.
941  */
942 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
943                                       __be16 *types)
944 {
945         types[0] = SCTP_PARAM_IPV6_ADDRESS;
946         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
947                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
948                 return 2;
949         }
950         return 1;
951 }
952
953 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
954 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
955                         int *uaddr_len, int peer)
956 {
957         int rc;
958
959         rc = inet6_getname(sock, uaddr, uaddr_len, peer);
960
961         if (rc != 0)
962                 return rc;
963
964         *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk),
965                                           (union sctp_addr *)uaddr);
966
967         return rc;
968 }
969
970 static const struct proto_ops inet6_seqpacket_ops = {
971         .family            = PF_INET6,
972         .owner             = THIS_MODULE,
973         .release           = inet6_release,
974         .bind              = inet6_bind,
975         .connect           = inet_dgram_connect,
976         .socketpair        = sock_no_socketpair,
977         .accept            = inet_accept,
978         .getname           = sctp_getname,
979         .poll              = sctp_poll,
980         .ioctl             = inet6_ioctl,
981         .listen            = sctp_inet_listen,
982         .shutdown          = inet_shutdown,
983         .setsockopt        = sock_common_setsockopt,
984         .getsockopt        = sock_common_getsockopt,
985         .sendmsg           = inet_sendmsg,
986         .recvmsg           = inet_recvmsg,
987         .mmap              = sock_no_mmap,
988 #ifdef CONFIG_COMPAT
989         .compat_setsockopt = compat_sock_common_setsockopt,
990         .compat_getsockopt = compat_sock_common_getsockopt,
991 #endif
992 };
993
994 static struct inet_protosw sctpv6_seqpacket_protosw = {
995         .type          = SOCK_SEQPACKET,
996         .protocol      = IPPROTO_SCTP,
997         .prot          = &sctpv6_prot,
998         .ops           = &inet6_seqpacket_ops,
999         .flags         = SCTP_PROTOSW_FLAG
1000 };
1001 static struct inet_protosw sctpv6_stream_protosw = {
1002         .type          = SOCK_STREAM,
1003         .protocol      = IPPROTO_SCTP,
1004         .prot          = &sctpv6_prot,
1005         .ops           = &inet6_seqpacket_ops,
1006         .flags         = SCTP_PROTOSW_FLAG,
1007 };
1008
1009 static int sctp6_rcv(struct sk_buff *skb)
1010 {
1011         return sctp_rcv(skb) ? -1 : 0;
1012 }
1013
1014 static const struct inet6_protocol sctpv6_protocol = {
1015         .handler      = sctp6_rcv,
1016         .err_handler  = sctp_v6_err,
1017         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1018 };
1019
1020 static struct sctp_af sctp_af_inet6 = {
1021         .sa_family         = AF_INET6,
1022         .sctp_xmit         = sctp_v6_xmit,
1023         .setsockopt        = ipv6_setsockopt,
1024         .getsockopt        = ipv6_getsockopt,
1025         .get_dst           = sctp_v6_get_dst,
1026         .get_saddr         = sctp_v6_get_saddr,
1027         .copy_addrlist     = sctp_v6_copy_addrlist,
1028         .from_skb          = sctp_v6_from_skb,
1029         .from_sk           = sctp_v6_from_sk,
1030         .from_addr_param   = sctp_v6_from_addr_param,
1031         .to_addr_param     = sctp_v6_to_addr_param,
1032         .cmp_addr          = sctp_v6_cmp_addr,
1033         .scope             = sctp_v6_scope,
1034         .addr_valid        = sctp_v6_addr_valid,
1035         .inaddr_any        = sctp_v6_inaddr_any,
1036         .is_any            = sctp_v6_is_any,
1037         .available         = sctp_v6_available,
1038         .skb_iif           = sctp_v6_skb_iif,
1039         .is_ce             = sctp_v6_is_ce,
1040         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1041         .ecn_capable       = sctp_v6_ecn_capable,
1042         .net_header_len    = sizeof(struct ipv6hdr),
1043         .sockaddr_len      = sizeof(struct sockaddr_in6),
1044 #ifdef CONFIG_COMPAT
1045         .compat_setsockopt = compat_ipv6_setsockopt,
1046         .compat_getsockopt = compat_ipv6_getsockopt,
1047 #endif
1048 };
1049
1050 static struct sctp_pf sctp_pf_inet6 = {
1051         .event_msgname = sctp_inet6_event_msgname,
1052         .skb_msgname   = sctp_inet6_skb_msgname,
1053         .af_supported  = sctp_inet6_af_supported,
1054         .cmp_addr      = sctp_inet6_cmp_addr,
1055         .bind_verify   = sctp_inet6_bind_verify,
1056         .send_verify   = sctp_inet6_send_verify,
1057         .supported_addrs = sctp_inet6_supported_addrs,
1058         .create_accept_sk = sctp_v6_create_accept_sk,
1059         .addr_to_user  = sctp_v6_addr_to_user,
1060         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1061         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1062         .af            = &sctp_af_inet6,
1063 };
1064
1065 /* Initialize IPv6 support and register with socket layer.  */
1066 void sctp_v6_pf_init(void)
1067 {
1068         /* Register the SCTP specific PF_INET6 functions. */
1069         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1070
1071         /* Register the SCTP specific AF_INET6 functions. */
1072         sctp_register_af(&sctp_af_inet6);
1073 }
1074
1075 void sctp_v6_pf_exit(void)
1076 {
1077         list_del(&sctp_af_inet6.list);
1078 }
1079
1080 /* Initialize IPv6 support and register with socket layer.  */
1081 int sctp_v6_protosw_init(void)
1082 {
1083         int rc;
1084
1085         rc = proto_register(&sctpv6_prot, 1);
1086         if (rc)
1087                 return rc;
1088
1089         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1090         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1091         inet6_register_protosw(&sctpv6_stream_protosw);
1092
1093         return 0;
1094 }
1095
1096 void sctp_v6_protosw_exit(void)
1097 {
1098         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1099         inet6_unregister_protosw(&sctpv6_stream_protosw);
1100         proto_unregister(&sctpv6_prot);
1101 }
1102
1103
1104 /* Register with inet6 layer. */
1105 int sctp_v6_add_protocol(void)
1106 {
1107         /* Register notifier for inet6 address additions/deletions. */
1108         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1109
1110         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1111                 return -EAGAIN;
1112
1113         return 0;
1114 }
1115
1116 /* Unregister with inet6 layer. */
1117 void sctp_v6_del_protocol(void)
1118 {
1119         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1120         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1121 }