Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-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, write to
25  * the Free Software Foundation, 59 Temple Place - Suite 330,
26  * Boston, MA 02111-1307, USA.
27  *
28  * Please send any bug reports or fixes you make to the
29  * email address(es):
30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
31  *
32  * Or submit a bug report through the following website:
33  *    http://www.sf.net/projects/lksctp
34  *
35  * Written or modified by:
36  *    Le Yanqun             <yanqun.le@nokia.com>
37  *    Hui Huang             <hui.huang@nokia.com>
38  *    La Monte H.P. Yarroll <piggy@acm.org>
39  *    Sridhar Samudrala     <sri@us.ibm.com>
40  *    Jon Grimm             <jgrimm@us.ibm.com>
41  *    Ardelle Fan           <ardelle.fan@intel.com>
42  *
43  * Based on:
44  *      linux/net/ipv6/tcp_ipv6.c
45  *
46  * Any bugs reported given to us we will try to fix... any fixes shared will
47  * be incorporated into the next SCTP release.
48  */
49
50 #include <linux/module.h>
51 #include <linux/errno.h>
52 #include <linux/types.h>
53 #include <linux/socket.h>
54 #include <linux/sockios.h>
55 #include <linux/net.h>
56 #include <linux/in.h>
57 #include <linux/in6.h>
58 #include <linux/netdevice.h>
59 #include <linux/init.h>
60 #include <linux/ipsec.h>
61
62 #include <linux/ipv6.h>
63 #include <linux/icmpv6.h>
64 #include <linux/random.h>
65 #include <linux/seq_file.h>
66
67 #include <net/protocol.h>
68 #include <net/ndisc.h>
69 #include <net/ip.h>
70 #include <net/ipv6.h>
71 #include <net/transp_v6.h>
72 #include <net/addrconf.h>
73 #include <net/ip6_route.h>
74 #include <net/inet_common.h>
75 #include <net/inet_ecn.h>
76 #include <net/sctp/sctp.h>
77
78 #include <asm/uaccess.h>
79
80 /* Event handler for inet6 address addition/deletion events.
81  * The sctp_local_addr_list needs to be protocted by a spin lock since
82  * multiple notifiers (say IPv4 and IPv6) may be running at the same
83  * time and thus corrupt the list.
84  * The reader side is protected with RCU.
85  */
86 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
87                                 void *ptr)
88 {
89         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
90         struct sctp_sockaddr_entry *addr = NULL;
91         struct sctp_sockaddr_entry *temp;
92         int found = 0;
93
94         switch (ev) {
95         case NETDEV_UP:
96                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
97                 if (addr) {
98                         addr->a.v6.sin6_family = AF_INET6;
99                         addr->a.v6.sin6_port = 0;
100                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
101                                  sizeof(struct in6_addr));
102                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
103                         addr->valid = 1;
104                         spin_lock_bh(&sctp_local_addr_lock);
105                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
106                         spin_unlock_bh(&sctp_local_addr_lock);
107                 }
108                 break;
109         case NETDEV_DOWN:
110                 spin_lock_bh(&sctp_local_addr_lock);
111                 list_for_each_entry_safe(addr, temp,
112                                         &sctp_local_addr_list, list) {
113                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
114                                              &ifa->addr)) {
115                                 found = 1;
116                                 addr->valid = 0;
117                                 list_del_rcu(&addr->list);
118                                 break;
119                         }
120                 }
121                 spin_unlock_bh(&sctp_local_addr_lock);
122                 if (found)
123                         call_rcu(&addr->rcu, sctp_local_addr_free);
124                 break;
125         }
126
127         return NOTIFY_DONE;
128 }
129
130 static struct notifier_block sctp_inet6addr_notifier = {
131         .notifier_call = sctp_inet6addr_event,
132 };
133
134 /* ICMP error handler. */
135 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
136                              int type, int code, int offset, __be32 info)
137 {
138         struct inet6_dev *idev;
139         struct sock *sk;
140         struct sctp_association *asoc;
141         struct sctp_transport *transport;
142         struct ipv6_pinfo *np;
143         sk_buff_data_t saveip, savesctp;
144         int err;
145
146         idev = in6_dev_get(skb->dev);
147
148         /* Fix up skb to look at the embedded net header. */
149         saveip   = skb->network_header;
150         savesctp = skb->transport_header;
151         skb_reset_network_header(skb);
152         skb_set_transport_header(skb, offset);
153         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
154         /* Put back, the original pointers. */
155         skb->network_header   = saveip;
156         skb->transport_header = savesctp;
157         if (!sk) {
158                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
159                 goto out;
160         }
161
162         /* Warning:  The sock lock is held.  Remember to call
163          * sctp_err_finish!
164          */
165
166         switch (type) {
167         case ICMPV6_PKT_TOOBIG:
168                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
169                 goto out_unlock;
170         case ICMPV6_PARAMPROB:
171                 if (ICMPV6_UNK_NEXTHDR == code) {
172                         sctp_icmp_proto_unreachable(sk, asoc, transport);
173                         goto out_unlock;
174                 }
175                 break;
176         default:
177                 break;
178         }
179
180         np = inet6_sk(sk);
181         icmpv6_err_convert(type, code, &err);
182         if (!sock_owned_by_user(sk) && np->recverr) {
183                 sk->sk_err = err;
184                 sk->sk_error_report(sk);
185         } else {  /* Only an error on timeout */
186                 sk->sk_err_soft = err;
187         }
188
189 out_unlock:
190         sctp_err_finish(sk, asoc);
191 out:
192         if (likely(idev != NULL))
193                 in6_dev_put(idev);
194 }
195
196 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
197 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
198                         int ipfragok)
199 {
200         struct sock *sk = skb->sk;
201         struct ipv6_pinfo *np = inet6_sk(sk);
202         struct flowi fl;
203
204         memset(&fl, 0, sizeof(fl));
205
206         fl.proto = sk->sk_protocol;
207
208         /* Fill in the dest address from the route entry passed with the skb
209          * and the source address from the transport.
210          */
211         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
212         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
213
214         fl.fl6_flowlabel = np->flow_label;
215         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
216         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
217                 fl.oif = transport->saddr.v6.sin6_scope_id;
218         else
219                 fl.oif = sk->sk_bound_dev_if;
220
221         if (np->opt && np->opt->srcrt) {
222                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
223                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
224         }
225
226         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
227                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
228                           __func__, skb, skb->len,
229                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
230
231         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
232
233         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
234 }
235
236 /* Returns the dst cache entry for the given source and destination ip
237  * addresses.
238  */
239 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
240                                          union sctp_addr *daddr,
241                                          union sctp_addr *saddr)
242 {
243         struct dst_entry *dst;
244         struct flowi fl;
245
246         memset(&fl, 0, sizeof(fl));
247         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
248         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
249                 fl.oif = daddr->v6.sin6_scope_id;
250
251
252         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
253                           __func__, NIP6(fl.fl6_dst));
254
255         if (saddr) {
256                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
257                 SCTP_DEBUG_PRINTK(
258                         "SRC=" NIP6_FMT " - ",
259                         NIP6(fl.fl6_src));
260         }
261
262         dst = ip6_route_output(&init_net, NULL, &fl);
263         if (!dst->error) {
264                 struct rt6_info *rt;
265                 rt = (struct rt6_info *)dst;
266                 SCTP_DEBUG_PRINTK(
267                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
268                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
269                 return dst;
270         }
271         SCTP_DEBUG_PRINTK("NO ROUTE\n");
272         dst_release(dst);
273         return NULL;
274 }
275
276 /* Returns the number of consecutive initial bits that match in the 2 ipv6
277  * addresses.
278  */
279 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
280                                          union sctp_addr *s2)
281 {
282         struct in6_addr *a1 = &s1->v6.sin6_addr;
283         struct in6_addr *a2 = &s2->v6.sin6_addr;
284         int i, j;
285
286         for (i = 0; i < 4 ; i++) {
287                 __be32 a1xora2;
288
289                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
290
291                 if ((j = fls(ntohl(a1xora2))))
292                         return (i * 32 + 32 - j);
293         }
294
295         return (i*32);
296 }
297
298 /* Fills in the source address(saddr) based on the destination address(daddr)
299  * and asoc's bind address list.
300  */
301 static void sctp_v6_get_saddr(struct sctp_association *asoc,
302                               struct dst_entry *dst,
303                               union sctp_addr *daddr,
304                               union sctp_addr *saddr)
305 {
306         struct sctp_bind_addr *bp;
307         struct sctp_sockaddr_entry *laddr;
308         sctp_scope_t scope;
309         union sctp_addr *baddr = NULL;
310         __u8 matchlen = 0;
311         __u8 bmatchlen;
312
313         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
314                           "daddr:" NIP6_FMT " ",
315                           __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
316
317         if (!asoc) {
318                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
319                                    &daddr->v6.sin6_addr, &saddr->v6.sin6_addr);
320                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
321                                   NIP6(saddr->v6.sin6_addr));
322                 return;
323         }
324
325         scope = sctp_scope(daddr);
326
327         bp = &asoc->base.bind_addr;
328
329         /* Go through the bind address list and find the best source address
330          * that matches the scope of the destination address.
331          */
332         rcu_read_lock();
333         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
334                 if (!laddr->valid)
335                         continue;
336                 if ((laddr->state == SCTP_ADDR_SRC) &&
337                     (laddr->a.sa.sa_family == AF_INET6) &&
338                     (scope <= sctp_scope(&laddr->a))) {
339                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
340                         if (!baddr || (matchlen < bmatchlen)) {
341                                 baddr = &laddr->a;
342                                 matchlen = bmatchlen;
343                         }
344                 }
345         }
346
347         if (baddr) {
348                 memcpy(saddr, baddr, sizeof(union sctp_addr));
349                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
350                                   NIP6(saddr->v6.sin6_addr));
351         } else {
352                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
353                        "address for the dest:" NIP6_FMT "\n",
354                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
355         }
356
357         rcu_read_unlock();
358 }
359
360 /* Make a copy of all potential local addresses. */
361 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
362                                   struct net_device *dev)
363 {
364         struct inet6_dev *in6_dev;
365         struct inet6_ifaddr *ifp;
366         struct sctp_sockaddr_entry *addr;
367
368         rcu_read_lock();
369         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
370                 rcu_read_unlock();
371                 return;
372         }
373
374         read_lock_bh(&in6_dev->lock);
375         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
376                 /* Add the address to the local list.  */
377                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
378                 if (addr) {
379                         addr->a.v6.sin6_family = AF_INET6;
380                         addr->a.v6.sin6_port = 0;
381                         addr->a.v6.sin6_addr = ifp->addr;
382                         addr->a.v6.sin6_scope_id = dev->ifindex;
383                         addr->valid = 1;
384                         INIT_LIST_HEAD(&addr->list);
385                         INIT_RCU_HEAD(&addr->rcu);
386                         list_add_tail(&addr->list, addrlist);
387                 }
388         }
389
390         read_unlock_bh(&in6_dev->lock);
391         rcu_read_unlock();
392 }
393
394 /* Initialize a sockaddr_storage from in incoming skb. */
395 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
396                              int is_saddr)
397 {
398         void *from;
399         __be16 *port;
400         struct sctphdr *sh;
401
402         port = &addr->v6.sin6_port;
403         addr->v6.sin6_family = AF_INET6;
404         addr->v6.sin6_flowinfo = 0; /* FIXME */
405         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
406
407         sh = sctp_hdr(skb);
408         if (is_saddr) {
409                 *port  = sh->source;
410                 from = &ipv6_hdr(skb)->saddr;
411         } else {
412                 *port = sh->dest;
413                 from = &ipv6_hdr(skb)->daddr;
414         }
415         ipv6_addr_copy(&addr->v6.sin6_addr, from);
416 }
417
418 /* Initialize an sctp_addr from a socket. */
419 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
420 {
421         addr->v6.sin6_family = AF_INET6;
422         addr->v6.sin6_port = 0;
423         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
424 }
425
426 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
427 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
428 {
429         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
430                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
431                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
432                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
433                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
434                         addr->v4.sin_addr.s_addr;
435         } else {
436                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
437         }
438 }
439
440 /* Initialize sk->sk_daddr from sctp_addr. */
441 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
442 {
443         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
444                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
445                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
446                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
447                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
448         } else {
449                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
450         }
451 }
452
453 /* Initialize a sctp_addr from an address parameter. */
454 static void sctp_v6_from_addr_param(union sctp_addr *addr,
455                                     union sctp_addr_param *param,
456                                     __be16 port, int iif)
457 {
458         addr->v6.sin6_family = AF_INET6;
459         addr->v6.sin6_port = port;
460         addr->v6.sin6_flowinfo = 0; /* BUG */
461         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
462         addr->v6.sin6_scope_id = iif;
463 }
464
465 /* Initialize an address parameter from a sctp_addr and return the length
466  * of the address parameter.
467  */
468 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
469                                  union sctp_addr_param *param)
470 {
471         int length = sizeof(sctp_ipv6addr_param_t);
472
473         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
474         param->v6.param_hdr.length = htons(length);
475         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
476
477         return length;
478 }
479
480 /* Initialize a sctp_addr from a dst_entry. */
481 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
482                               __be16 port)
483 {
484         struct rt6_info *rt = (struct rt6_info *)dst;
485         addr->sa.sa_family = AF_INET6;
486         addr->v6.sin6_port = port;
487         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
488 }
489
490 /* Compare addresses exactly.
491  * v4-mapped-v6 is also in consideration.
492  */
493 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
494                             const union sctp_addr *addr2)
495 {
496         if (addr1->sa.sa_family != addr2->sa.sa_family) {
497                 if (addr1->sa.sa_family == AF_INET &&
498                     addr2->sa.sa_family == AF_INET6 &&
499                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
500                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
501                             addr2->v6.sin6_addr.s6_addr32[3] ==
502                             addr1->v4.sin_addr.s_addr)
503                                 return 1;
504                 }
505                 if (addr2->sa.sa_family == AF_INET &&
506                     addr1->sa.sa_family == AF_INET6 &&
507                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
508                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
509                             addr1->v6.sin6_addr.s6_addr32[3] ==
510                             addr2->v4.sin_addr.s_addr)
511                                 return 1;
512                 }
513                 return 0;
514         }
515         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
516                 return 0;
517         /* If this is a linklocal address, compare the scope_id. */
518         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
519                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
520                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
521                         return 0;
522                 }
523         }
524
525         return 1;
526 }
527
528 /* Initialize addr struct to INADDR_ANY. */
529 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
530 {
531         memset(addr, 0x00, sizeof(union sctp_addr));
532         addr->v6.sin6_family = AF_INET6;
533         addr->v6.sin6_port = port;
534 }
535
536 /* Is this a wildcard address? */
537 static int sctp_v6_is_any(const union sctp_addr *addr)
538 {
539         return ipv6_addr_any(&addr->v6.sin6_addr);
540 }
541
542 /* Should this be available for binding?   */
543 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
544 {
545         int type;
546         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
547
548         type = ipv6_addr_type(in6);
549         if (IPV6_ADDR_ANY == type)
550                 return 1;
551         if (type == IPV6_ADDR_MAPPED) {
552                 if (sp && !sp->v4mapped)
553                         return 0;
554                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
555                         return 0;
556                 sctp_v6_map_v4(addr);
557                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
558         }
559         if (!(type & IPV6_ADDR_UNICAST))
560                 return 0;
561
562         return ipv6_chk_addr(&init_net, in6, NULL, 0);
563 }
564
565 /* This function checks if the address is a valid address to be used for
566  * SCTP.
567  *
568  * Output:
569  * Return 0 - If the address is a non-unicast or an illegal address.
570  * Return 1 - If the address is a unicast.
571  */
572 static int sctp_v6_addr_valid(union sctp_addr *addr,
573                               struct sctp_sock *sp,
574                               const struct sk_buff *skb)
575 {
576         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
577
578         /* Support v4-mapped-v6 address. */
579         if (ret == IPV6_ADDR_MAPPED) {
580                 /* Note: This routine is used in input, so v4-mapped-v6
581                  * are disallowed here when there is no sctp_sock.
582                  */
583                 if (!sp || !sp->v4mapped)
584                         return 0;
585                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
586                         return 0;
587                 sctp_v6_map_v4(addr);
588                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
589         }
590
591         /* Is this a non-unicast address */
592         if (!(ret & IPV6_ADDR_UNICAST))
593                 return 0;
594
595         return 1;
596 }
597
598 /* What is the scope of 'addr'?  */
599 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
600 {
601         int v6scope;
602         sctp_scope_t retval;
603
604         /* The IPv6 scope is really a set of bit fields.
605          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
606          */
607
608         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
609         switch (v6scope) {
610         case IFA_HOST:
611                 retval = SCTP_SCOPE_LOOPBACK;
612                 break;
613         case IFA_LINK:
614                 retval = SCTP_SCOPE_LINK;
615                 break;
616         case IFA_SITE:
617                 retval = SCTP_SCOPE_PRIVATE;
618                 break;
619         default:
620                 retval = SCTP_SCOPE_GLOBAL;
621                 break;
622         }
623
624         return retval;
625 }
626
627 /* Create and initialize a new sk for the socket to be returned by accept(). */
628 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
629                                              struct sctp_association *asoc)
630 {
631         struct inet_sock *inet = inet_sk(sk);
632         struct sock *newsk;
633         struct inet_sock *newinet;
634         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
635         struct sctp6_sock *newsctp6sk;
636
637         newsk = sk_alloc(sk->sk_net, PF_INET6, GFP_KERNEL, sk->sk_prot);
638         if (!newsk)
639                 goto out;
640
641         sock_init_data(NULL, newsk);
642
643         newsk->sk_type = SOCK_STREAM;
644
645         newsk->sk_prot = sk->sk_prot;
646         newsk->sk_no_check = sk->sk_no_check;
647         newsk->sk_reuse = sk->sk_reuse;
648
649         newsk->sk_destruct = inet_sock_destruct;
650         newsk->sk_family = PF_INET6;
651         newsk->sk_protocol = IPPROTO_SCTP;
652         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
653         newsk->sk_shutdown = sk->sk_shutdown;
654         sock_reset_flag(sk, SOCK_ZAPPED);
655
656         newsctp6sk = (struct sctp6_sock *)newsk;
657         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
658
659         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
660
661         newinet = inet_sk(newsk);
662         newnp = inet6_sk(newsk);
663
664         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
665
666         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
667          * and getpeername().
668          */
669         newinet->sport = inet->sport;
670         newnp->saddr = np->saddr;
671         newnp->rcv_saddr = np->rcv_saddr;
672         newinet->dport = htons(asoc->peer.port);
673         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
674
675         /* Init the ipv4 part of the socket since we can have sockets
676          * using v6 API for ipv4.
677          */
678         newinet->uc_ttl = -1;
679         newinet->mc_loop = 1;
680         newinet->mc_ttl = 1;
681         newinet->mc_index = 0;
682         newinet->mc_list = NULL;
683
684         if (ipv4_config.no_pmtu_disc)
685                 newinet->pmtudisc = IP_PMTUDISC_DONT;
686         else
687                 newinet->pmtudisc = IP_PMTUDISC_WANT;
688
689         sk_refcnt_debug_inc(newsk);
690
691         if (newsk->sk_prot->init(newsk)) {
692                 sk_common_release(newsk);
693                 newsk = NULL;
694         }
695
696 out:
697         return newsk;
698 }
699
700 /* Map v4 address to mapped v6 address */
701 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
702 {
703         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
704                 sctp_v4_map_v6(addr);
705 }
706
707 /* Where did this skb come from?  */
708 static int sctp_v6_skb_iif(const struct sk_buff *skb)
709 {
710         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
711         return opt->iif;
712 }
713
714 /* Was this packet marked by Explicit Congestion Notification? */
715 static int sctp_v6_is_ce(const struct sk_buff *skb)
716 {
717         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
718 }
719
720 /* Dump the v6 addr to the seq file. */
721 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
722 {
723         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
724 }
725
726 /* Initialize a PF_INET6 socket msg_name. */
727 static void sctp_inet6_msgname(char *msgname, int *addr_len)
728 {
729         struct sockaddr_in6 *sin6;
730
731         sin6 = (struct sockaddr_in6 *)msgname;
732         sin6->sin6_family = AF_INET6;
733         sin6->sin6_flowinfo = 0;
734         sin6->sin6_scope_id = 0; /*FIXME */
735         *addr_len = sizeof(struct sockaddr_in6);
736 }
737
738 /* Initialize a PF_INET msgname from a ulpevent. */
739 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
740                                      char *msgname, int *addrlen)
741 {
742         struct sockaddr_in6 *sin6, *sin6from;
743
744         if (msgname) {
745                 union sctp_addr *addr;
746                 struct sctp_association *asoc;
747
748                 asoc = event->asoc;
749                 sctp_inet6_msgname(msgname, addrlen);
750                 sin6 = (struct sockaddr_in6 *)msgname;
751                 sin6->sin6_port = htons(asoc->peer.port);
752                 addr = &asoc->peer.primary_addr;
753
754                 /* Note: If we go to a common v6 format, this code
755                  * will change.
756                  */
757
758                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
759                 if (sctp_sk(asoc->base.sk)->v4mapped &&
760                     AF_INET == addr->sa.sa_family) {
761                         sctp_v4_map_v6((union sctp_addr *)sin6);
762                         sin6->sin6_addr.s6_addr32[3] =
763                                 addr->v4.sin_addr.s_addr;
764                         return;
765                 }
766
767                 sin6from = &asoc->peer.primary_addr.v6;
768                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
769                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
770                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
771         }
772 }
773
774 /* Initialize a msg_name from an inbound skb. */
775 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
776                                    int *addr_len)
777 {
778         struct sctphdr *sh;
779         struct sockaddr_in6 *sin6;
780
781         if (msgname) {
782                 sctp_inet6_msgname(msgname, addr_len);
783                 sin6 = (struct sockaddr_in6 *)msgname;
784                 sh = sctp_hdr(skb);
785                 sin6->sin6_port = sh->source;
786
787                 /* Map ipv4 address into v4-mapped-on-v6 address. */
788                 if (sctp_sk(skb->sk)->v4mapped &&
789                     ip_hdr(skb)->version == 4) {
790                         sctp_v4_map_v6((union sctp_addr *)sin6);
791                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
792                         return;
793                 }
794
795                 /* Otherwise, just copy the v6 address. */
796                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
797                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
798                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
799                         sin6->sin6_scope_id = ev->iif;
800                 }
801         }
802 }
803
804 /* Do we support this AF? */
805 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
806 {
807         switch (family) {
808         case AF_INET6:
809                 return 1;
810         /* v4-mapped-v6 addresses */
811         case AF_INET:
812                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
813                         return 1;
814         default:
815                 return 0;
816         }
817 }
818
819 /* Address matching with wildcards allowed.  This extra level
820  * of indirection lets us choose whether a PF_INET6 should
821  * disallow any v4 addresses if we so choose.
822  */
823 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
824                                const union sctp_addr *addr2,
825                                struct sctp_sock *opt)
826 {
827         struct sctp_af *af1, *af2;
828
829         af1 = sctp_get_af_specific(addr1->sa.sa_family);
830         af2 = sctp_get_af_specific(addr2->sa.sa_family);
831
832         if (!af1 || !af2)
833                 return 0;
834         /* Today, wildcard AF_INET/AF_INET6. */
835         if (sctp_is_any(addr1) || sctp_is_any(addr2))
836                 return 1;
837
838         if (addr1->sa.sa_family != addr2->sa.sa_family)
839                 return 0;
840
841         return af1->cmp_addr(addr1, addr2);
842 }
843
844 /* Verify that the provided sockaddr looks bindable.   Common verification,
845  * has already been taken care of.
846  */
847 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
848 {
849         struct sctp_af *af;
850
851         /* ASSERT: address family has already been verified. */
852         if (addr->sa.sa_family != AF_INET6)
853                 af = sctp_get_af_specific(addr->sa.sa_family);
854         else {
855                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
856                 struct net_device *dev;
857
858                 if (type & IPV6_ADDR_LINKLOCAL) {
859                         if (!addr->v6.sin6_scope_id)
860                                 return 0;
861                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
862                         if (!dev)
863                                 return 0;
864                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
865                                            dev, 0)) {
866                                 dev_put(dev);
867                                 return 0;
868                         }
869                         dev_put(dev);
870                 }
871                 af = opt->pf->af;
872         }
873         return af->available(addr, opt);
874 }
875
876 /* Verify that the provided sockaddr looks sendable.   Common verification,
877  * has already been taken care of.
878  */
879 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
880 {
881         struct sctp_af *af = NULL;
882
883         /* ASSERT: address family has already been verified. */
884         if (addr->sa.sa_family != AF_INET6)
885                 af = sctp_get_af_specific(addr->sa.sa_family);
886         else {
887                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
888                 struct net_device *dev;
889
890                 if (type & IPV6_ADDR_LINKLOCAL) {
891                         if (!addr->v6.sin6_scope_id)
892                                 return 0;
893                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
894                         if (!dev)
895                                 return 0;
896                         dev_put(dev);
897                 }
898                 af = opt->pf->af;
899         }
900
901         return af != NULL;
902 }
903
904 /* Fill in Supported Address Type information for INIT and INIT-ACK
905  * chunks.   Note: In the future, we may want to look at sock options
906  * to determine whether a PF_INET6 socket really wants to have IPV4
907  * addresses.
908  * Returns number of addresses supported.
909  */
910 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
911                                       __be16 *types)
912 {
913         types[0] = SCTP_PARAM_IPV4_ADDRESS;
914         types[1] = SCTP_PARAM_IPV6_ADDRESS;
915         return 2;
916 }
917
918 static const struct proto_ops inet6_seqpacket_ops = {
919         .family            = PF_INET6,
920         .owner             = THIS_MODULE,
921         .release           = inet6_release,
922         .bind              = inet6_bind,
923         .connect           = inet_dgram_connect,
924         .socketpair        = sock_no_socketpair,
925         .accept            = inet_accept,
926         .getname           = inet6_getname,
927         .poll              = sctp_poll,
928         .ioctl             = inet6_ioctl,
929         .listen            = sctp_inet_listen,
930         .shutdown          = inet_shutdown,
931         .setsockopt        = sock_common_setsockopt,
932         .getsockopt        = sock_common_getsockopt,
933         .sendmsg           = inet_sendmsg,
934         .recvmsg           = sock_common_recvmsg,
935         .mmap              = sock_no_mmap,
936 #ifdef CONFIG_COMPAT
937         .compat_setsockopt = compat_sock_common_setsockopt,
938         .compat_getsockopt = compat_sock_common_getsockopt,
939 #endif
940 };
941
942 static struct inet_protosw sctpv6_seqpacket_protosw = {
943         .type          = SOCK_SEQPACKET,
944         .protocol      = IPPROTO_SCTP,
945         .prot          = &sctpv6_prot,
946         .ops           = &inet6_seqpacket_ops,
947         .capability    = -1,
948         .no_check      = 0,
949         .flags         = SCTP_PROTOSW_FLAG
950 };
951 static struct inet_protosw sctpv6_stream_protosw = {
952         .type          = SOCK_STREAM,
953         .protocol      = IPPROTO_SCTP,
954         .prot          = &sctpv6_prot,
955         .ops           = &inet6_seqpacket_ops,
956         .capability    = -1,
957         .no_check      = 0,
958         .flags         = SCTP_PROTOSW_FLAG,
959 };
960
961 static int sctp6_rcv(struct sk_buff *skb)
962 {
963         return sctp_rcv(skb) ? -1 : 0;
964 }
965
966 static struct inet6_protocol sctpv6_protocol = {
967         .handler      = sctp6_rcv,
968         .err_handler  = sctp_v6_err,
969         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
970 };
971
972 static struct sctp_af sctp_af_inet6 = {
973         .sa_family         = AF_INET6,
974         .sctp_xmit         = sctp_v6_xmit,
975         .setsockopt        = ipv6_setsockopt,
976         .getsockopt        = ipv6_getsockopt,
977         .get_dst           = sctp_v6_get_dst,
978         .get_saddr         = sctp_v6_get_saddr,
979         .copy_addrlist     = sctp_v6_copy_addrlist,
980         .from_skb          = sctp_v6_from_skb,
981         .from_sk           = sctp_v6_from_sk,
982         .to_sk_saddr       = sctp_v6_to_sk_saddr,
983         .to_sk_daddr       = sctp_v6_to_sk_daddr,
984         .from_addr_param   = sctp_v6_from_addr_param,
985         .to_addr_param     = sctp_v6_to_addr_param,
986         .dst_saddr         = sctp_v6_dst_saddr,
987         .cmp_addr          = sctp_v6_cmp_addr,
988         .scope             = sctp_v6_scope,
989         .addr_valid        = sctp_v6_addr_valid,
990         .inaddr_any        = sctp_v6_inaddr_any,
991         .is_any            = sctp_v6_is_any,
992         .available         = sctp_v6_available,
993         .skb_iif           = sctp_v6_skb_iif,
994         .is_ce             = sctp_v6_is_ce,
995         .seq_dump_addr     = sctp_v6_seq_dump_addr,
996         .net_header_len    = sizeof(struct ipv6hdr),
997         .sockaddr_len      = sizeof(struct sockaddr_in6),
998 #ifdef CONFIG_COMPAT
999         .compat_setsockopt = compat_ipv6_setsockopt,
1000         .compat_getsockopt = compat_ipv6_getsockopt,
1001 #endif
1002 };
1003
1004 static struct sctp_pf sctp_pf_inet6 = {
1005         .event_msgname = sctp_inet6_event_msgname,
1006         .skb_msgname   = sctp_inet6_skb_msgname,
1007         .af_supported  = sctp_inet6_af_supported,
1008         .cmp_addr      = sctp_inet6_cmp_addr,
1009         .bind_verify   = sctp_inet6_bind_verify,
1010         .send_verify   = sctp_inet6_send_verify,
1011         .supported_addrs = sctp_inet6_supported_addrs,
1012         .create_accept_sk = sctp_v6_create_accept_sk,
1013         .addr_v4map    = sctp_v6_addr_v4map,
1014         .af            = &sctp_af_inet6,
1015 };
1016
1017 /* Initialize IPv6 support and register with socket layer.  */
1018 int sctp_v6_init(void)
1019 {
1020         int rc;
1021
1022         /* Register the SCTP specific PF_INET6 functions. */
1023         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1024
1025         /* Register the SCTP specific AF_INET6 functions. */
1026         sctp_register_af(&sctp_af_inet6);
1027
1028         rc = proto_register(&sctpv6_prot, 1);
1029         if (rc)
1030                 return rc;
1031
1032         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1033         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1034         inet6_register_protosw(&sctpv6_stream_protosw);
1035
1036         return 0;
1037 }
1038
1039 /* Register with inet6 layer. */
1040 int sctp_v6_add_protocol(void)
1041 {
1042         /* Register notifier for inet6 address additions/deletions. */
1043         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1044
1045         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1046                 return -EAGAIN;
1047
1048         return 0;
1049 }
1050
1051 /* IPv6 specific exit support. */
1052 void sctp_v6_exit(void)
1053 {
1054         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1055         inet6_unregister_protosw(&sctpv6_stream_protosw);
1056         proto_unregister(&sctpv6_prot);
1057         list_del(&sctp_af_inet6.list);
1058 }
1059
1060 /* Unregister with inet6 layer. */
1061 void sctp_v6_del_protocol(void)
1062 {
1063         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1064         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1065 }