bd04aed673cb838cfdceb3d8483f7db3eafe2665
[linux-2.6.git] / net / sctp / ipv6.c
1 /* SCTP kernel reference 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 reference Implementation
8  *
9  * SCTP over IPv6.
10  *
11  * The SCTP reference 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  * The SCTP reference 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
93         switch (ev) {
94         case NETDEV_UP:
95                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
96                 if (addr) {
97                         addr->a.v6.sin6_family = AF_INET6;
98                         addr->a.v6.sin6_port = 0;
99                         memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
100                                  sizeof(struct in6_addr));
101                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
102                         addr->valid = 1;
103                         spin_lock_bh(&sctp_local_addr_lock);
104                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
105                         spin_unlock_bh(&sctp_local_addr_lock);
106                 }
107                 break;
108         case NETDEV_DOWN:
109                 spin_lock_bh(&sctp_local_addr_lock);
110                 list_for_each_entry_safe(addr, temp,
111                                         &sctp_local_addr_list, list) {
112                         if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
113                                              &ifa->addr)) {
114                                 addr->valid = 0;
115                                 list_del_rcu(&addr->list);
116                                 break;
117                         }
118                 }
119                 spin_unlock_bh(&sctp_local_addr_lock);
120                 if (addr && !addr->valid)
121                         call_rcu(&addr->rcu, sctp_local_addr_free);
122                 break;
123         }
124
125         return NOTIFY_DONE;
126 }
127
128 static struct notifier_block sctp_inet6addr_notifier = {
129         .notifier_call = sctp_inet6addr_event,
130 };
131
132 /* ICMP error handler. */
133 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
134                              int type, int code, int offset, __be32 info)
135 {
136         struct inet6_dev *idev;
137         struct sock *sk;
138         struct sctp_association *asoc;
139         struct sctp_transport *transport;
140         struct ipv6_pinfo *np;
141         sk_buff_data_t saveip, savesctp;
142         int err;
143
144         idev = in6_dev_get(skb->dev);
145
146         /* Fix up skb to look at the embedded net header. */
147         saveip   = skb->network_header;
148         savesctp = skb->transport_header;
149         skb_reset_network_header(skb);
150         skb_set_transport_header(skb, offset);
151         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
152         /* Put back, the original pointers. */
153         skb->network_header   = saveip;
154         skb->transport_header = savesctp;
155         if (!sk) {
156                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
157                 goto out;
158         }
159
160         /* Warning:  The sock lock is held.  Remember to call
161          * sctp_err_finish!
162          */
163
164         switch (type) {
165         case ICMPV6_PKT_TOOBIG:
166                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
167                 goto out_unlock;
168         case ICMPV6_PARAMPROB:
169                 if (ICMPV6_UNK_NEXTHDR == code) {
170                         sctp_icmp_proto_unreachable(sk, asoc, transport);
171                         goto out_unlock;
172                 }
173                 break;
174         default:
175                 break;
176         }
177
178         np = inet6_sk(sk);
179         icmpv6_err_convert(type, code, &err);
180         if (!sock_owned_by_user(sk) && np->recverr) {
181                 sk->sk_err = err;
182                 sk->sk_error_report(sk);
183         } else {  /* Only an error on timeout */
184                 sk->sk_err_soft = err;
185         }
186
187 out_unlock:
188         sctp_err_finish(sk, asoc);
189 out:
190         if (likely(idev != NULL))
191                 in6_dev_put(idev);
192 }
193
194 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
195 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
196                         int ipfragok)
197 {
198         struct sock *sk = skb->sk;
199         struct ipv6_pinfo *np = inet6_sk(sk);
200         struct flowi fl;
201
202         memset(&fl, 0, sizeof(fl));
203
204         fl.proto = sk->sk_protocol;
205
206         /* Fill in the dest address from the route entry passed with the skb
207          * and the source address from the transport.
208          */
209         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
210         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
211
212         fl.fl6_flowlabel = np->flow_label;
213         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
214         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
215                 fl.oif = transport->saddr.v6.sin6_scope_id;
216         else
217                 fl.oif = sk->sk_bound_dev_if;
218
219         if (np->opt && np->opt->srcrt) {
220                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
221                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
222         }
223
224         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
225                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
226                           __FUNCTION__, skb, skb->len,
227                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
228
229         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
230
231         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
232 }
233
234 /* Returns the dst cache entry for the given source and destination ip
235  * addresses.
236  */
237 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
238                                          union sctp_addr *daddr,
239                                          union sctp_addr *saddr)
240 {
241         struct dst_entry *dst;
242         struct flowi fl;
243
244         memset(&fl, 0, sizeof(fl));
245         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
246         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
247                 fl.oif = daddr->v6.sin6_scope_id;
248
249
250         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
251                           __FUNCTION__, NIP6(fl.fl6_dst));
252
253         if (saddr) {
254                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
255                 SCTP_DEBUG_PRINTK(
256                         "SRC=" NIP6_FMT " - ",
257                         NIP6(fl.fl6_src));
258         }
259
260         dst = ip6_route_output(NULL, &fl);
261         if (!dst->error) {
262                 struct rt6_info *rt;
263                 rt = (struct rt6_info *)dst;
264                 SCTP_DEBUG_PRINTK(
265                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
266                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
267                 return dst;
268         }
269         SCTP_DEBUG_PRINTK("NO ROUTE\n");
270         dst_release(dst);
271         return NULL;
272 }
273
274 /* Returns the number of consecutive initial bits that match in the 2 ipv6
275  * addresses.
276  */
277 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
278                                          union sctp_addr *s2)
279 {
280         struct in6_addr *a1 = &s1->v6.sin6_addr;
281         struct in6_addr *a2 = &s2->v6.sin6_addr;
282         int i, j;
283
284         for (i = 0; i < 4 ; i++) {
285                 __be32 a1xora2;
286
287                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
288
289                 if ((j = fls(ntohl(a1xora2))))
290                         return (i * 32 + 32 - j);
291         }
292
293         return (i*32);
294 }
295
296 /* Fills in the source address(saddr) based on the destination address(daddr)
297  * and asoc's bind address list.
298  */
299 static void sctp_v6_get_saddr(struct sctp_association *asoc,
300                               struct dst_entry *dst,
301                               union sctp_addr *daddr,
302                               union sctp_addr *saddr)
303 {
304         struct sctp_bind_addr *bp;
305         struct sctp_sockaddr_entry *laddr;
306         sctp_scope_t scope;
307         union sctp_addr *baddr = NULL;
308         __u8 matchlen = 0;
309         __u8 bmatchlen;
310
311         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
312                           "daddr:" NIP6_FMT " ",
313                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
314
315         if (!asoc) {
316                 ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
317                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
318                                   NIP6(saddr->v6.sin6_addr));
319                 return;
320         }
321
322         scope = sctp_scope(daddr);
323
324         bp = &asoc->base.bind_addr;
325
326         /* Go through the bind address list and find the best source address
327          * that matches the scope of the destination address.
328          */
329         rcu_read_lock();
330         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
331                 if (!laddr->valid)
332                         continue;
333                 if ((laddr->state == SCTP_ADDR_SRC) &&
334                     (laddr->a.sa.sa_family == AF_INET6) &&
335                     (scope <= sctp_scope(&laddr->a))) {
336                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
337                         if (!baddr || (matchlen < bmatchlen)) {
338                                 baddr = &laddr->a;
339                                 matchlen = bmatchlen;
340                         }
341                 }
342         }
343
344         if (baddr) {
345                 memcpy(saddr, baddr, sizeof(union sctp_addr));
346                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
347                                   NIP6(saddr->v6.sin6_addr));
348         } else {
349                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
350                        "address for the dest:" NIP6_FMT "\n",
351                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
352         }
353
354         rcu_read_unlock();
355 }
356
357 /* Make a copy of all potential local addresses. */
358 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
359                                   struct net_device *dev)
360 {
361         struct inet6_dev *in6_dev;
362         struct inet6_ifaddr *ifp;
363         struct sctp_sockaddr_entry *addr;
364
365         rcu_read_lock();
366         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
367                 rcu_read_unlock();
368                 return;
369         }
370
371         read_lock_bh(&in6_dev->lock);
372         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
373                 /* Add the address to the local list.  */
374                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
375                 if (addr) {
376                         addr->a.v6.sin6_family = AF_INET6;
377                         addr->a.v6.sin6_port = 0;
378                         addr->a.v6.sin6_addr = ifp->addr;
379                         addr->a.v6.sin6_scope_id = dev->ifindex;
380                         addr->valid = 1;
381                         INIT_LIST_HEAD(&addr->list);
382                         INIT_RCU_HEAD(&addr->rcu);
383                         list_add_tail(&addr->list, addrlist);
384                 }
385         }
386
387         read_unlock_bh(&in6_dev->lock);
388         rcu_read_unlock();
389 }
390
391 /* Initialize a sockaddr_storage from in incoming skb. */
392 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
393                              int is_saddr)
394 {
395         void *from;
396         __be16 *port;
397         struct sctphdr *sh;
398
399         port = &addr->v6.sin6_port;
400         addr->v6.sin6_family = AF_INET6;
401         addr->v6.sin6_flowinfo = 0; /* FIXME */
402         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
403
404         sh = sctp_hdr(skb);
405         if (is_saddr) {
406                 *port  = sh->source;
407                 from = &ipv6_hdr(skb)->saddr;
408         } else {
409                 *port = sh->dest;
410                 from = &ipv6_hdr(skb)->daddr;
411         }
412         ipv6_addr_copy(&addr->v6.sin6_addr, from);
413 }
414
415 /* Initialize an sctp_addr from a socket. */
416 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
417 {
418         addr->v6.sin6_family = AF_INET6;
419         addr->v6.sin6_port = 0;
420         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
421 }
422
423 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
424 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
425 {
426         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
427                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
428                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
429                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
430                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
431                         addr->v4.sin_addr.s_addr;
432         } else {
433                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
434         }
435 }
436
437 /* Initialize sk->sk_daddr from sctp_addr. */
438 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
439 {
440         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
441                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
442                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
443                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
444                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
445         } else {
446                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
447         }
448 }
449
450 /* Initialize a sctp_addr from an address parameter. */
451 static void sctp_v6_from_addr_param(union sctp_addr *addr,
452                                     union sctp_addr_param *param,
453                                     __be16 port, int iif)
454 {
455         addr->v6.sin6_family = AF_INET6;
456         addr->v6.sin6_port = port;
457         addr->v6.sin6_flowinfo = 0; /* BUG */
458         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
459         addr->v6.sin6_scope_id = iif;
460 }
461
462 /* Initialize an address parameter from a sctp_addr and return the length
463  * of the address parameter.
464  */
465 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
466                                  union sctp_addr_param *param)
467 {
468         int length = sizeof(sctp_ipv6addr_param_t);
469
470         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
471         param->v6.param_hdr.length = htons(length);
472         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
473
474         return length;
475 }
476
477 /* Initialize a sctp_addr from a dst_entry. */
478 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
479                               __be16 port)
480 {
481         struct rt6_info *rt = (struct rt6_info *)dst;
482         addr->sa.sa_family = AF_INET6;
483         addr->v6.sin6_port = port;
484         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
485 }
486
487 /* Compare addresses exactly.
488  * v4-mapped-v6 is also in consideration.
489  */
490 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
491                             const union sctp_addr *addr2)
492 {
493         if (addr1->sa.sa_family != addr2->sa.sa_family) {
494                 if (addr1->sa.sa_family == AF_INET &&
495                     addr2->sa.sa_family == AF_INET6 &&
496                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
497                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
498                             addr2->v6.sin6_addr.s6_addr32[3] ==
499                             addr1->v4.sin_addr.s_addr)
500                                 return 1;
501                 }
502                 if (addr2->sa.sa_family == AF_INET &&
503                     addr1->sa.sa_family == AF_INET6 &&
504                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
505                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
506                             addr1->v6.sin6_addr.s6_addr32[3] ==
507                             addr2->v4.sin_addr.s_addr)
508                                 return 1;
509                 }
510                 return 0;
511         }
512         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
513                 return 0;
514         /* If this is a linklocal address, compare the scope_id. */
515         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
516                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
517                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
518                         return 0;
519                 }
520         }
521
522         return 1;
523 }
524
525 /* Initialize addr struct to INADDR_ANY. */
526 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
527 {
528         memset(addr, 0x00, sizeof(union sctp_addr));
529         addr->v6.sin6_family = AF_INET6;
530         addr->v6.sin6_port = port;
531 }
532
533 /* Is this a wildcard address? */
534 static int sctp_v6_is_any(const union sctp_addr *addr)
535 {
536         return ipv6_addr_any(&addr->v6.sin6_addr);
537 }
538
539 /* Should this be available for binding?   */
540 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
541 {
542         int type;
543         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
544
545         type = ipv6_addr_type(in6);
546         if (IPV6_ADDR_ANY == type)
547                 return 1;
548         if (type == IPV6_ADDR_MAPPED) {
549                 if (sp && !sp->v4mapped)
550                         return 0;
551                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
552                         return 0;
553                 sctp_v6_map_v4(addr);
554                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
555         }
556         if (!(type & IPV6_ADDR_UNICAST))
557                 return 0;
558
559         return ipv6_chk_addr(in6, NULL, 0);
560 }
561
562 /* This function checks if the address is a valid address to be used for
563  * SCTP.
564  *
565  * Output:
566  * Return 0 - If the address is a non-unicast or an illegal address.
567  * Return 1 - If the address is a unicast.
568  */
569 static int sctp_v6_addr_valid(union sctp_addr *addr,
570                               struct sctp_sock *sp,
571                               const struct sk_buff *skb)
572 {
573         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
574
575         /* Support v4-mapped-v6 address. */
576         if (ret == IPV6_ADDR_MAPPED) {
577                 /* Note: This routine is used in input, so v4-mapped-v6
578                  * are disallowed here when there is no sctp_sock.
579                  */
580                 if (!sp || !sp->v4mapped)
581                         return 0;
582                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
583                         return 0;
584                 sctp_v6_map_v4(addr);
585                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
586         }
587
588         /* Is this a non-unicast address */
589         if (!(ret & IPV6_ADDR_UNICAST))
590                 return 0;
591
592         return 1;
593 }
594
595 /* What is the scope of 'addr'?  */
596 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
597 {
598         int v6scope;
599         sctp_scope_t retval;
600
601         /* The IPv6 scope is really a set of bit fields.
602          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
603          */
604
605         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
606         switch (v6scope) {
607         case IFA_HOST:
608                 retval = SCTP_SCOPE_LOOPBACK;
609                 break;
610         case IFA_LINK:
611                 retval = SCTP_SCOPE_LINK;
612                 break;
613         case IFA_SITE:
614                 retval = SCTP_SCOPE_PRIVATE;
615                 break;
616         default:
617                 retval = SCTP_SCOPE_GLOBAL;
618                 break;
619         }
620
621         return retval;
622 }
623
624 /* Create and initialize a new sk for the socket to be returned by accept(). */
625 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
626                                              struct sctp_association *asoc)
627 {
628         struct inet_sock *inet = inet_sk(sk);
629         struct sock *newsk;
630         struct inet_sock *newinet;
631         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
632         struct sctp6_sock *newsctp6sk;
633
634         newsk = sk_alloc(sk->sk_net, PF_INET6, GFP_KERNEL, sk->sk_prot);
635         if (!newsk)
636                 goto out;
637
638         sock_init_data(NULL, newsk);
639
640         newsk->sk_type = SOCK_STREAM;
641
642         newsk->sk_prot = sk->sk_prot;
643         newsk->sk_no_check = sk->sk_no_check;
644         newsk->sk_reuse = sk->sk_reuse;
645
646         newsk->sk_destruct = inet_sock_destruct;
647         newsk->sk_family = PF_INET6;
648         newsk->sk_protocol = IPPROTO_SCTP;
649         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
650         newsk->sk_shutdown = sk->sk_shutdown;
651         sock_reset_flag(sk, SOCK_ZAPPED);
652
653         newsctp6sk = (struct sctp6_sock *)newsk;
654         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
655
656         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
657
658         newinet = inet_sk(newsk);
659         newnp = inet6_sk(newsk);
660
661         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
662
663         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
664          * and getpeername().
665          */
666         newinet->sport = inet->sport;
667         newnp->saddr = np->saddr;
668         newnp->rcv_saddr = np->rcv_saddr;
669         newinet->dport = htons(asoc->peer.port);
670         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
671
672         /* Init the ipv4 part of the socket since we can have sockets
673          * using v6 API for ipv4.
674          */
675         newinet->uc_ttl = -1;
676         newinet->mc_loop = 1;
677         newinet->mc_ttl = 1;
678         newinet->mc_index = 0;
679         newinet->mc_list = NULL;
680
681         if (ipv4_config.no_pmtu_disc)
682                 newinet->pmtudisc = IP_PMTUDISC_DONT;
683         else
684                 newinet->pmtudisc = IP_PMTUDISC_WANT;
685
686         sk_refcnt_debug_inc(newsk);
687
688         if (newsk->sk_prot->init(newsk)) {
689                 sk_common_release(newsk);
690                 newsk = NULL;
691         }
692
693 out:
694         return newsk;
695 }
696
697 /* Map v4 address to mapped v6 address */
698 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
699 {
700         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
701                 sctp_v4_map_v6(addr);
702 }
703
704 /* Where did this skb come from?  */
705 static int sctp_v6_skb_iif(const struct sk_buff *skb)
706 {
707         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
708         return opt->iif;
709 }
710
711 /* Was this packet marked by Explicit Congestion Notification? */
712 static int sctp_v6_is_ce(const struct sk_buff *skb)
713 {
714         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
715 }
716
717 /* Dump the v6 addr to the seq file. */
718 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
719 {
720         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
721 }
722
723 /* Initialize a PF_INET6 socket msg_name. */
724 static void sctp_inet6_msgname(char *msgname, int *addr_len)
725 {
726         struct sockaddr_in6 *sin6;
727
728         sin6 = (struct sockaddr_in6 *)msgname;
729         sin6->sin6_family = AF_INET6;
730         sin6->sin6_flowinfo = 0;
731         sin6->sin6_scope_id = 0; /*FIXME */
732         *addr_len = sizeof(struct sockaddr_in6);
733 }
734
735 /* Initialize a PF_INET msgname from a ulpevent. */
736 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
737                                      char *msgname, int *addrlen)
738 {
739         struct sockaddr_in6 *sin6, *sin6from;
740
741         if (msgname) {
742                 union sctp_addr *addr;
743                 struct sctp_association *asoc;
744
745                 asoc = event->asoc;
746                 sctp_inet6_msgname(msgname, addrlen);
747                 sin6 = (struct sockaddr_in6 *)msgname;
748                 sin6->sin6_port = htons(asoc->peer.port);
749                 addr = &asoc->peer.primary_addr;
750
751                 /* Note: If we go to a common v6 format, this code
752                  * will change.
753                  */
754
755                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
756                 if (sctp_sk(asoc->base.sk)->v4mapped &&
757                     AF_INET == addr->sa.sa_family) {
758                         sctp_v4_map_v6((union sctp_addr *)sin6);
759                         sin6->sin6_addr.s6_addr32[3] =
760                                 addr->v4.sin_addr.s_addr;
761                         return;
762                 }
763
764                 sin6from = &asoc->peer.primary_addr.v6;
765                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
766                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
767                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
768         }
769 }
770
771 /* Initialize a msg_name from an inbound skb. */
772 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
773                                    int *addr_len)
774 {
775         struct sctphdr *sh;
776         struct sockaddr_in6 *sin6;
777
778         if (msgname) {
779                 sctp_inet6_msgname(msgname, addr_len);
780                 sin6 = (struct sockaddr_in6 *)msgname;
781                 sh = sctp_hdr(skb);
782                 sin6->sin6_port = sh->source;
783
784                 /* Map ipv4 address into v4-mapped-on-v6 address. */
785                 if (sctp_sk(skb->sk)->v4mapped &&
786                     ip_hdr(skb)->version == 4) {
787                         sctp_v4_map_v6((union sctp_addr *)sin6);
788                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
789                         return;
790                 }
791
792                 /* Otherwise, just copy the v6 address. */
793                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
794                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
795                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
796                         sin6->sin6_scope_id = ev->iif;
797                 }
798         }
799 }
800
801 /* Do we support this AF? */
802 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
803 {
804         switch (family) {
805         case AF_INET6:
806                 return 1;
807         /* v4-mapped-v6 addresses */
808         case AF_INET:
809                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
810                         return 1;
811         default:
812                 return 0;
813         }
814 }
815
816 /* Address matching with wildcards allowed.  This extra level
817  * of indirection lets us choose whether a PF_INET6 should
818  * disallow any v4 addresses if we so choose.
819  */
820 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
821                                const union sctp_addr *addr2,
822                                struct sctp_sock *opt)
823 {
824         struct sctp_af *af1, *af2;
825
826         af1 = sctp_get_af_specific(addr1->sa.sa_family);
827         af2 = sctp_get_af_specific(addr2->sa.sa_family);
828
829         if (!af1 || !af2)
830                 return 0;
831         /* Today, wildcard AF_INET/AF_INET6. */
832         if (sctp_is_any(addr1) || sctp_is_any(addr2))
833                 return 1;
834
835         if (addr1->sa.sa_family != addr2->sa.sa_family)
836                 return 0;
837
838         return af1->cmp_addr(addr1, addr2);
839 }
840
841 /* Verify that the provided sockaddr looks bindable.   Common verification,
842  * has already been taken care of.
843  */
844 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
845 {
846         struct sctp_af *af;
847
848         /* ASSERT: address family has already been verified. */
849         if (addr->sa.sa_family != AF_INET6)
850                 af = sctp_get_af_specific(addr->sa.sa_family);
851         else {
852                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
853                 struct net_device *dev;
854
855                 if (type & IPV6_ADDR_LINKLOCAL) {
856                         if (!addr->v6.sin6_scope_id)
857                                 return 0;
858                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
859                         if (!dev)
860                                 return 0;
861                         if (!ipv6_chk_addr(&addr->v6.sin6_addr, dev, 0)) {
862                                 dev_put(dev);
863                                 return 0;
864                         }
865                         dev_put(dev);
866                 }
867                 af = opt->pf->af;
868         }
869         return af->available(addr, opt);
870 }
871
872 /* Verify that the provided sockaddr looks sendable.   Common verification,
873  * has already been taken care of.
874  */
875 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
876 {
877         struct sctp_af *af = NULL;
878
879         /* ASSERT: address family has already been verified. */
880         if (addr->sa.sa_family != AF_INET6)
881                 af = sctp_get_af_specific(addr->sa.sa_family);
882         else {
883                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
884                 struct net_device *dev;
885
886                 if (type & IPV6_ADDR_LINKLOCAL) {
887                         if (!addr->v6.sin6_scope_id)
888                                 return 0;
889                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
890                         if (!dev)
891                                 return 0;
892                         dev_put(dev);
893                 }
894                 af = opt->pf->af;
895         }
896
897         return af != NULL;
898 }
899
900 /* Fill in Supported Address Type information for INIT and INIT-ACK
901  * chunks.   Note: In the future, we may want to look at sock options
902  * to determine whether a PF_INET6 socket really wants to have IPV4
903  * addresses.
904  * Returns number of addresses supported.
905  */
906 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
907                                       __be16 *types)
908 {
909         types[0] = SCTP_PARAM_IPV4_ADDRESS;
910         types[1] = SCTP_PARAM_IPV6_ADDRESS;
911         return 2;
912 }
913
914 static const struct proto_ops inet6_seqpacket_ops = {
915         .family            = PF_INET6,
916         .owner             = THIS_MODULE,
917         .release           = inet6_release,
918         .bind              = inet6_bind,
919         .connect           = inet_dgram_connect,
920         .socketpair        = sock_no_socketpair,
921         .accept            = inet_accept,
922         .getname           = inet6_getname,
923         .poll              = sctp_poll,
924         .ioctl             = inet6_ioctl,
925         .listen            = sctp_inet_listen,
926         .shutdown          = inet_shutdown,
927         .setsockopt        = sock_common_setsockopt,
928         .getsockopt        = sock_common_getsockopt,
929         .sendmsg           = inet_sendmsg,
930         .recvmsg           = sock_common_recvmsg,
931         .mmap              = sock_no_mmap,
932 #ifdef CONFIG_COMPAT
933         .compat_setsockopt = compat_sock_common_setsockopt,
934         .compat_getsockopt = compat_sock_common_getsockopt,
935 #endif
936 };
937
938 static struct inet_protosw sctpv6_seqpacket_protosw = {
939         .type          = SOCK_SEQPACKET,
940         .protocol      = IPPROTO_SCTP,
941         .prot          = &sctpv6_prot,
942         .ops           = &inet6_seqpacket_ops,
943         .capability    = -1,
944         .no_check      = 0,
945         .flags         = SCTP_PROTOSW_FLAG
946 };
947 static struct inet_protosw sctpv6_stream_protosw = {
948         .type          = SOCK_STREAM,
949         .protocol      = IPPROTO_SCTP,
950         .prot          = &sctpv6_prot,
951         .ops           = &inet6_seqpacket_ops,
952         .capability    = -1,
953         .no_check      = 0,
954         .flags         = SCTP_PROTOSW_FLAG,
955 };
956
957 static int sctp6_rcv(struct sk_buff *skb)
958 {
959         return sctp_rcv(skb) ? -1 : 0;
960 }
961
962 static struct inet6_protocol sctpv6_protocol = {
963         .handler      = sctp6_rcv,
964         .err_handler  = sctp_v6_err,
965         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
966 };
967
968 static struct sctp_af sctp_ipv6_specific = {
969         .sa_family         = AF_INET6,
970         .sctp_xmit         = sctp_v6_xmit,
971         .setsockopt        = ipv6_setsockopt,
972         .getsockopt        = ipv6_getsockopt,
973         .get_dst           = sctp_v6_get_dst,
974         .get_saddr         = sctp_v6_get_saddr,
975         .copy_addrlist     = sctp_v6_copy_addrlist,
976         .from_skb          = sctp_v6_from_skb,
977         .from_sk           = sctp_v6_from_sk,
978         .to_sk_saddr       = sctp_v6_to_sk_saddr,
979         .to_sk_daddr       = sctp_v6_to_sk_daddr,
980         .from_addr_param   = sctp_v6_from_addr_param,
981         .to_addr_param     = sctp_v6_to_addr_param,
982         .dst_saddr         = sctp_v6_dst_saddr,
983         .cmp_addr          = sctp_v6_cmp_addr,
984         .scope             = sctp_v6_scope,
985         .addr_valid        = sctp_v6_addr_valid,
986         .inaddr_any        = sctp_v6_inaddr_any,
987         .is_any            = sctp_v6_is_any,
988         .available         = sctp_v6_available,
989         .skb_iif           = sctp_v6_skb_iif,
990         .is_ce             = sctp_v6_is_ce,
991         .seq_dump_addr     = sctp_v6_seq_dump_addr,
992         .net_header_len    = sizeof(struct ipv6hdr),
993         .sockaddr_len      = sizeof(struct sockaddr_in6),
994 #ifdef CONFIG_COMPAT
995         .compat_setsockopt = compat_ipv6_setsockopt,
996         .compat_getsockopt = compat_ipv6_getsockopt,
997 #endif
998 };
999
1000 static struct sctp_pf sctp_pf_inet6_specific = {
1001         .event_msgname = sctp_inet6_event_msgname,
1002         .skb_msgname   = sctp_inet6_skb_msgname,
1003         .af_supported  = sctp_inet6_af_supported,
1004         .cmp_addr      = sctp_inet6_cmp_addr,
1005         .bind_verify   = sctp_inet6_bind_verify,
1006         .send_verify   = sctp_inet6_send_verify,
1007         .supported_addrs = sctp_inet6_supported_addrs,
1008         .create_accept_sk = sctp_v6_create_accept_sk,
1009         .addr_v4map    = sctp_v6_addr_v4map,
1010         .af            = &sctp_ipv6_specific,
1011 };
1012
1013 /* Initialize IPv6 support and register with socket layer.  */
1014 int sctp_v6_init(void)
1015 {
1016         int rc;
1017
1018         /* Register the SCTP specific PF_INET6 functions. */
1019         sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
1020
1021         /* Register the SCTP specific AF_INET6 functions. */
1022         sctp_register_af(&sctp_ipv6_specific);
1023
1024         rc = proto_register(&sctpv6_prot, 1);
1025         if (rc)
1026                 return rc;
1027
1028         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1029         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1030         inet6_register_protosw(&sctpv6_stream_protosw);
1031
1032         return 0;
1033 }
1034
1035 /* Register with inet6 layer. */
1036 int sctp_v6_add_protocol(void)
1037 {
1038         /* Register notifier for inet6 address additions/deletions. */
1039         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1040
1041         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1042                 return -EAGAIN;
1043
1044         return 0;
1045 }
1046
1047 /* IPv6 specific exit support. */
1048 void sctp_v6_exit(void)
1049 {
1050         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1051         inet6_unregister_protosw(&sctpv6_stream_protosw);
1052         proto_unregister(&sctpv6_prot);
1053         list_del(&sctp_ipv6_specific.list);
1054 }
1055
1056 /* Unregister with inet6 layer. */
1057 void sctp_v6_del_protocol(void)
1058 {
1059         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1060         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1061 }