a238d6834b33ad1ba2728ebbd026016c3b88fc57
[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 (addr->a.sa.sa_family == AF_INET6 &&
114                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
115                                                 &ifa->addr)) {
116                                 found = 1;
117                                 addr->valid = 0;
118                                 list_del_rcu(&addr->list);
119                                 break;
120                         }
121                 }
122                 spin_unlock_bh(&sctp_local_addr_lock);
123                 if (found)
124                         call_rcu(&addr->rcu, sctp_local_addr_free);
125                 break;
126         }
127
128         return NOTIFY_DONE;
129 }
130
131 static struct notifier_block sctp_inet6addr_notifier = {
132         .notifier_call = sctp_inet6addr_event,
133 };
134
135 /* ICMP error handler. */
136 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
137                              int type, int code, int offset, __be32 info)
138 {
139         struct inet6_dev *idev;
140         struct sock *sk;
141         struct sctp_association *asoc;
142         struct sctp_transport *transport;
143         struct ipv6_pinfo *np;
144         sk_buff_data_t saveip, savesctp;
145         int err;
146
147         idev = in6_dev_get(skb->dev);
148
149         /* Fix up skb to look at the embedded net header. */
150         saveip   = skb->network_header;
151         savesctp = skb->transport_header;
152         skb_reset_network_header(skb);
153         skb_set_transport_header(skb, offset);
154         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
155         /* Put back, the original pointers. */
156         skb->network_header   = saveip;
157         skb->transport_header = savesctp;
158         if (!sk) {
159                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
160                 goto out;
161         }
162
163         /* Warning:  The sock lock is held.  Remember to call
164          * sctp_err_finish!
165          */
166
167         switch (type) {
168         case ICMPV6_PKT_TOOBIG:
169                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
170                 goto out_unlock;
171         case ICMPV6_PARAMPROB:
172                 if (ICMPV6_UNK_NEXTHDR == code) {
173                         sctp_icmp_proto_unreachable(sk, asoc, transport);
174                         goto out_unlock;
175                 }
176                 break;
177         default:
178                 break;
179         }
180
181         np = inet6_sk(sk);
182         icmpv6_err_convert(type, code, &err);
183         if (!sock_owned_by_user(sk) && np->recverr) {
184                 sk->sk_err = err;
185                 sk->sk_error_report(sk);
186         } else {  /* Only an error on timeout */
187                 sk->sk_err_soft = err;
188         }
189
190 out_unlock:
191         sctp_err_finish(sk, asoc);
192 out:
193         if (likely(idev != NULL))
194                 in6_dev_put(idev);
195 }
196
197 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
198 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
199                         int ipfragok)
200 {
201         struct sock *sk = skb->sk;
202         struct ipv6_pinfo *np = inet6_sk(sk);
203         struct flowi fl;
204
205         memset(&fl, 0, sizeof(fl));
206
207         fl.proto = sk->sk_protocol;
208
209         /* Fill in the dest address from the route entry passed with the skb
210          * and the source address from the transport.
211          */
212         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
213         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
214
215         fl.fl6_flowlabel = np->flow_label;
216         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
217         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
218                 fl.oif = transport->saddr.v6.sin6_scope_id;
219         else
220                 fl.oif = sk->sk_bound_dev_if;
221
222         if (np->opt && np->opt->srcrt) {
223                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
224                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
225         }
226
227         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
228                           "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
229                           __func__, skb, skb->len,
230                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
231
232         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
233
234         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
235 }
236
237 /* Returns the dst cache entry for the given source and destination ip
238  * addresses.
239  */
240 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
241                                          union sctp_addr *daddr,
242                                          union sctp_addr *saddr)
243 {
244         struct dst_entry *dst;
245         struct flowi fl;
246
247         memset(&fl, 0, sizeof(fl));
248         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
249         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
250                 fl.oif = daddr->v6.sin6_scope_id;
251
252
253         SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
254                           __func__, NIP6(fl.fl6_dst));
255
256         if (saddr) {
257                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
258                 SCTP_DEBUG_PRINTK(
259                         "SRC=" NIP6_FMT " - ",
260                         NIP6(fl.fl6_src));
261         }
262
263         dst = ip6_route_output(&init_net, NULL, &fl);
264         if (!dst->error) {
265                 struct rt6_info *rt;
266                 rt = (struct rt6_info *)dst;
267                 SCTP_DEBUG_PRINTK(
268                         "rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
269                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
270                 return dst;
271         }
272         SCTP_DEBUG_PRINTK("NO ROUTE\n");
273         dst_release(dst);
274         return NULL;
275 }
276
277 /* Returns the number of consecutive initial bits that match in the 2 ipv6
278  * addresses.
279  */
280 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
281                                          union sctp_addr *s2)
282 {
283         struct in6_addr *a1 = &s1->v6.sin6_addr;
284         struct in6_addr *a2 = &s2->v6.sin6_addr;
285         int i, j;
286
287         for (i = 0; i < 4 ; i++) {
288                 __be32 a1xora2;
289
290                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
291
292                 if ((j = fls(ntohl(a1xora2))))
293                         return (i * 32 + 32 - j);
294         }
295
296         return (i*32);
297 }
298
299 /* Fills in the source address(saddr) based on the destination address(daddr)
300  * and asoc's bind address list.
301  */
302 static void sctp_v6_get_saddr(struct sctp_sock *sk,
303                               struct sctp_association *asoc,
304                               struct dst_entry *dst,
305                               union sctp_addr *daddr,
306                               union sctp_addr *saddr)
307 {
308         struct sctp_bind_addr *bp;
309         struct sctp_sockaddr_entry *laddr;
310         sctp_scope_t scope;
311         union sctp_addr *baddr = NULL;
312         __u8 matchlen = 0;
313         __u8 bmatchlen;
314
315         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
316                           "daddr:" NIP6_FMT " ",
317                           __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
318
319         if (!asoc) {
320                 ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
321                                    &daddr->v6.sin6_addr,
322                                    inet6_sk(&sk->inet.sk)->srcprefs,
323                                    &saddr->v6.sin6_addr);
324                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
325                                   NIP6(saddr->v6.sin6_addr));
326                 return;
327         }
328
329         scope = sctp_scope(daddr);
330
331         bp = &asoc->base.bind_addr;
332
333         /* Go through the bind address list and find the best source address
334          * that matches the scope of the destination address.
335          */
336         rcu_read_lock();
337         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
338                 if (!laddr->valid)
339                         continue;
340                 if ((laddr->state == SCTP_ADDR_SRC) &&
341                     (laddr->a.sa.sa_family == AF_INET6) &&
342                     (scope <= sctp_scope(&laddr->a))) {
343                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
344                         if (!baddr || (matchlen < bmatchlen)) {
345                                 baddr = &laddr->a;
346                                 matchlen = bmatchlen;
347                         }
348                 }
349         }
350
351         if (baddr) {
352                 memcpy(saddr, baddr, sizeof(union sctp_addr));
353                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
354                                   NIP6(saddr->v6.sin6_addr));
355         } else {
356                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
357                        "address for the dest:" NIP6_FMT "\n",
358                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
359         }
360
361         rcu_read_unlock();
362 }
363
364 /* Make a copy of all potential local addresses. */
365 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
366                                   struct net_device *dev)
367 {
368         struct inet6_dev *in6_dev;
369         struct inet6_ifaddr *ifp;
370         struct sctp_sockaddr_entry *addr;
371
372         rcu_read_lock();
373         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
374                 rcu_read_unlock();
375                 return;
376         }
377
378         read_lock_bh(&in6_dev->lock);
379         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
380                 /* Add the address to the local list.  */
381                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
382                 if (addr) {
383                         addr->a.v6.sin6_family = AF_INET6;
384                         addr->a.v6.sin6_port = 0;
385                         addr->a.v6.sin6_addr = ifp->addr;
386                         addr->a.v6.sin6_scope_id = dev->ifindex;
387                         addr->valid = 1;
388                         INIT_LIST_HEAD(&addr->list);
389                         INIT_RCU_HEAD(&addr->rcu);
390                         list_add_tail(&addr->list, addrlist);
391                 }
392         }
393
394         read_unlock_bh(&in6_dev->lock);
395         rcu_read_unlock();
396 }
397
398 /* Initialize a sockaddr_storage from in incoming skb. */
399 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
400                              int is_saddr)
401 {
402         void *from;
403         __be16 *port;
404         struct sctphdr *sh;
405
406         port = &addr->v6.sin6_port;
407         addr->v6.sin6_family = AF_INET6;
408         addr->v6.sin6_flowinfo = 0; /* FIXME */
409         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
410
411         sh = sctp_hdr(skb);
412         if (is_saddr) {
413                 *port  = sh->source;
414                 from = &ipv6_hdr(skb)->saddr;
415         } else {
416                 *port = sh->dest;
417                 from = &ipv6_hdr(skb)->daddr;
418         }
419         ipv6_addr_copy(&addr->v6.sin6_addr, from);
420 }
421
422 /* Initialize an sctp_addr from a socket. */
423 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
424 {
425         addr->v6.sin6_family = AF_INET6;
426         addr->v6.sin6_port = 0;
427         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
428 }
429
430 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
431 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
432 {
433         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
434                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
435                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
436                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
437                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
438                         addr->v4.sin_addr.s_addr;
439         } else {
440                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
441         }
442 }
443
444 /* Initialize sk->sk_daddr from sctp_addr. */
445 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
446 {
447         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
448                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
449                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
450                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
451                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
452         } else {
453                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
454         }
455 }
456
457 /* Initialize a sctp_addr from an address parameter. */
458 static void sctp_v6_from_addr_param(union sctp_addr *addr,
459                                     union sctp_addr_param *param,
460                                     __be16 port, int iif)
461 {
462         addr->v6.sin6_family = AF_INET6;
463         addr->v6.sin6_port = port;
464         addr->v6.sin6_flowinfo = 0; /* BUG */
465         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
466         addr->v6.sin6_scope_id = iif;
467 }
468
469 /* Initialize an address parameter from a sctp_addr and return the length
470  * of the address parameter.
471  */
472 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
473                                  union sctp_addr_param *param)
474 {
475         int length = sizeof(sctp_ipv6addr_param_t);
476
477         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
478         param->v6.param_hdr.length = htons(length);
479         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
480
481         return length;
482 }
483
484 /* Initialize a sctp_addr from a dst_entry. */
485 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
486                               __be16 port)
487 {
488         struct rt6_info *rt = (struct rt6_info *)dst;
489         addr->sa.sa_family = AF_INET6;
490         addr->v6.sin6_port = port;
491         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
492 }
493
494 /* Compare addresses exactly.
495  * v4-mapped-v6 is also in consideration.
496  */
497 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
498                             const union sctp_addr *addr2)
499 {
500         if (addr1->sa.sa_family != addr2->sa.sa_family) {
501                 if (addr1->sa.sa_family == AF_INET &&
502                     addr2->sa.sa_family == AF_INET6 &&
503                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
504                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
505                             addr2->v6.sin6_addr.s6_addr32[3] ==
506                             addr1->v4.sin_addr.s_addr)
507                                 return 1;
508                 }
509                 if (addr2->sa.sa_family == AF_INET &&
510                     addr1->sa.sa_family == AF_INET6 &&
511                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
512                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
513                             addr1->v6.sin6_addr.s6_addr32[3] ==
514                             addr2->v4.sin_addr.s_addr)
515                                 return 1;
516                 }
517                 return 0;
518         }
519         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
520                 return 0;
521         /* If this is a linklocal address, compare the scope_id. */
522         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
523                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
524                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
525                         return 0;
526                 }
527         }
528
529         return 1;
530 }
531
532 /* Initialize addr struct to INADDR_ANY. */
533 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
534 {
535         memset(addr, 0x00, sizeof(union sctp_addr));
536         addr->v6.sin6_family = AF_INET6;
537         addr->v6.sin6_port = port;
538 }
539
540 /* Is this a wildcard address? */
541 static int sctp_v6_is_any(const union sctp_addr *addr)
542 {
543         return ipv6_addr_any(&addr->v6.sin6_addr);
544 }
545
546 /* Should this be available for binding?   */
547 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
548 {
549         int type;
550         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
551
552         type = ipv6_addr_type(in6);
553         if (IPV6_ADDR_ANY == type)
554                 return 1;
555         if (type == IPV6_ADDR_MAPPED) {
556                 if (sp && !sp->v4mapped)
557                         return 0;
558                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
559                         return 0;
560                 sctp_v6_map_v4(addr);
561                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
562         }
563         if (!(type & IPV6_ADDR_UNICAST))
564                 return 0;
565
566         return ipv6_chk_addr(&init_net, in6, NULL, 0);
567 }
568
569 /* This function checks if the address is a valid address to be used for
570  * SCTP.
571  *
572  * Output:
573  * Return 0 - If the address is a non-unicast or an illegal address.
574  * Return 1 - If the address is a unicast.
575  */
576 static int sctp_v6_addr_valid(union sctp_addr *addr,
577                               struct sctp_sock *sp,
578                               const struct sk_buff *skb)
579 {
580         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
581
582         /* Support v4-mapped-v6 address. */
583         if (ret == IPV6_ADDR_MAPPED) {
584                 /* Note: This routine is used in input, so v4-mapped-v6
585                  * are disallowed here when there is no sctp_sock.
586                  */
587                 if (!sp || !sp->v4mapped)
588                         return 0;
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)->addr_valid(addr, sp, skb);
593         }
594
595         /* Is this a non-unicast address */
596         if (!(ret & IPV6_ADDR_UNICAST))
597                 return 0;
598
599         return 1;
600 }
601
602 /* What is the scope of 'addr'?  */
603 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
604 {
605         int v6scope;
606         sctp_scope_t retval;
607
608         /* The IPv6 scope is really a set of bit fields.
609          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
610          */
611
612         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
613         switch (v6scope) {
614         case IFA_HOST:
615                 retval = SCTP_SCOPE_LOOPBACK;
616                 break;
617         case IFA_LINK:
618                 retval = SCTP_SCOPE_LINK;
619                 break;
620         case IFA_SITE:
621                 retval = SCTP_SCOPE_PRIVATE;
622                 break;
623         default:
624                 retval = SCTP_SCOPE_GLOBAL;
625                 break;
626         }
627
628         return retval;
629 }
630
631 /* Create and initialize a new sk for the socket to be returned by accept(). */
632 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
633                                              struct sctp_association *asoc)
634 {
635         struct inet_sock *inet = inet_sk(sk);
636         struct sock *newsk;
637         struct inet_sock *newinet;
638         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
639         struct sctp6_sock *newsctp6sk;
640
641         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
642         if (!newsk)
643                 goto out;
644
645         sock_init_data(NULL, newsk);
646
647         newsk->sk_type = SOCK_STREAM;
648
649         newsk->sk_prot = sk->sk_prot;
650         newsk->sk_no_check = sk->sk_no_check;
651         newsk->sk_reuse = sk->sk_reuse;
652
653         newsk->sk_destruct = inet_sock_destruct;
654         newsk->sk_family = PF_INET6;
655         newsk->sk_protocol = IPPROTO_SCTP;
656         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
657         newsk->sk_shutdown = sk->sk_shutdown;
658         sock_reset_flag(sk, SOCK_ZAPPED);
659
660         newsctp6sk = (struct sctp6_sock *)newsk;
661         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
662
663         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
664
665         newinet = inet_sk(newsk);
666         newnp = inet6_sk(newsk);
667
668         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
669
670         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
671          * and getpeername().
672          */
673         newinet->sport = inet->sport;
674         newnp->saddr = np->saddr;
675         newnp->rcv_saddr = np->rcv_saddr;
676         newinet->dport = htons(asoc->peer.port);
677         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
678
679         /* Init the ipv4 part of the socket since we can have sockets
680          * using v6 API for ipv4.
681          */
682         newinet->uc_ttl = -1;
683         newinet->mc_loop = 1;
684         newinet->mc_ttl = 1;
685         newinet->mc_index = 0;
686         newinet->mc_list = NULL;
687
688         if (ipv4_config.no_pmtu_disc)
689                 newinet->pmtudisc = IP_PMTUDISC_DONT;
690         else
691                 newinet->pmtudisc = IP_PMTUDISC_WANT;
692
693         sk_refcnt_debug_inc(newsk);
694
695         if (newsk->sk_prot->init(newsk)) {
696                 sk_common_release(newsk);
697                 newsk = NULL;
698         }
699
700 out:
701         return newsk;
702 }
703
704 /* Map v4 address to mapped v6 address */
705 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
706 {
707         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
708                 sctp_v4_map_v6(addr);
709 }
710
711 /* Where did this skb come from?  */
712 static int sctp_v6_skb_iif(const struct sk_buff *skb)
713 {
714         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
715         return opt->iif;
716 }
717
718 /* Was this packet marked by Explicit Congestion Notification? */
719 static int sctp_v6_is_ce(const struct sk_buff *skb)
720 {
721         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
722 }
723
724 /* Dump the v6 addr to the seq file. */
725 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
726 {
727         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
728 }
729
730 static void sctp_v6_ecn_capable(struct sock *sk)
731 {
732         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
733 }
734
735 /* Initialize a PF_INET6 socket msg_name. */
736 static void sctp_inet6_msgname(char *msgname, int *addr_len)
737 {
738         struct sockaddr_in6 *sin6;
739
740         sin6 = (struct sockaddr_in6 *)msgname;
741         sin6->sin6_family = AF_INET6;
742         sin6->sin6_flowinfo = 0;
743         sin6->sin6_scope_id = 0; /*FIXME */
744         *addr_len = sizeof(struct sockaddr_in6);
745 }
746
747 /* Initialize a PF_INET msgname from a ulpevent. */
748 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
749                                      char *msgname, int *addrlen)
750 {
751         struct sockaddr_in6 *sin6, *sin6from;
752
753         if (msgname) {
754                 union sctp_addr *addr;
755                 struct sctp_association *asoc;
756
757                 asoc = event->asoc;
758                 sctp_inet6_msgname(msgname, addrlen);
759                 sin6 = (struct sockaddr_in6 *)msgname;
760                 sin6->sin6_port = htons(asoc->peer.port);
761                 addr = &asoc->peer.primary_addr;
762
763                 /* Note: If we go to a common v6 format, this code
764                  * will change.
765                  */
766
767                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
768                 if (sctp_sk(asoc->base.sk)->v4mapped &&
769                     AF_INET == addr->sa.sa_family) {
770                         sctp_v4_map_v6((union sctp_addr *)sin6);
771                         sin6->sin6_addr.s6_addr32[3] =
772                                 addr->v4.sin_addr.s_addr;
773                         return;
774                 }
775
776                 sin6from = &asoc->peer.primary_addr.v6;
777                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
778                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
779                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
780         }
781 }
782
783 /* Initialize a msg_name from an inbound skb. */
784 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
785                                    int *addr_len)
786 {
787         struct sctphdr *sh;
788         struct sockaddr_in6 *sin6;
789
790         if (msgname) {
791                 sctp_inet6_msgname(msgname, addr_len);
792                 sin6 = (struct sockaddr_in6 *)msgname;
793                 sh = sctp_hdr(skb);
794                 sin6->sin6_port = sh->source;
795
796                 /* Map ipv4 address into v4-mapped-on-v6 address. */
797                 if (sctp_sk(skb->sk)->v4mapped &&
798                     ip_hdr(skb)->version == 4) {
799                         sctp_v4_map_v6((union sctp_addr *)sin6);
800                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
801                         return;
802                 }
803
804                 /* Otherwise, just copy the v6 address. */
805                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
806                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
807                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
808                         sin6->sin6_scope_id = ev->iif;
809                 }
810         }
811 }
812
813 /* Do we support this AF? */
814 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
815 {
816         switch (family) {
817         case AF_INET6:
818                 return 1;
819         /* v4-mapped-v6 addresses */
820         case AF_INET:
821                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
822                         return 1;
823         default:
824                 return 0;
825         }
826 }
827
828 /* Address matching with wildcards allowed.  This extra level
829  * of indirection lets us choose whether a PF_INET6 should
830  * disallow any v4 addresses if we so choose.
831  */
832 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
833                                const union sctp_addr *addr2,
834                                struct sctp_sock *opt)
835 {
836         struct sctp_af *af1, *af2;
837
838         af1 = sctp_get_af_specific(addr1->sa.sa_family);
839         af2 = sctp_get_af_specific(addr2->sa.sa_family);
840
841         if (!af1 || !af2)
842                 return 0;
843
844         /* If the socket is IPv6 only, v4 addrs will not match */
845         if (__ipv6_only_sock(sctp_opt2sk(opt)) && af1 != af2)
846                 return 0;
847
848         /* Today, wildcard AF_INET/AF_INET6. */
849         if (sctp_is_any(addr1) || sctp_is_any(addr2))
850                 return 1;
851
852         if (addr1->sa.sa_family != addr2->sa.sa_family)
853                 return 0;
854
855         return af1->cmp_addr(addr1, addr2);
856 }
857
858 /* Verify that the provided sockaddr looks bindable.   Common verification,
859  * has already been taken care of.
860  */
861 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
862 {
863         struct sctp_af *af;
864
865         /* ASSERT: address family has already been verified. */
866         if (addr->sa.sa_family != AF_INET6)
867                 af = sctp_get_af_specific(addr->sa.sa_family);
868         else {
869                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
870                 struct net_device *dev;
871
872                 if (type & IPV6_ADDR_LINKLOCAL) {
873                         if (!addr->v6.sin6_scope_id)
874                                 return 0;
875                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
876                         if (!dev)
877                                 return 0;
878                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
879                                            dev, 0)) {
880                                 dev_put(dev);
881                                 return 0;
882                         }
883                         dev_put(dev);
884                 } else if (type == IPV6_ADDR_MAPPED) {
885                         if (!opt->v4mapped)
886                                 return 0;
887                 }
888
889                 af = opt->pf->af;
890         }
891         return af->available(addr, opt);
892 }
893
894 /* Verify that the provided sockaddr looks sendable.   Common verification,
895  * has already been taken care of.
896  */
897 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
898 {
899         struct sctp_af *af = NULL;
900
901         /* ASSERT: address family has already been verified. */
902         if (addr->sa.sa_family != AF_INET6)
903                 af = sctp_get_af_specific(addr->sa.sa_family);
904         else {
905                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
906                 struct net_device *dev;
907
908                 if (type & IPV6_ADDR_LINKLOCAL) {
909                         if (!addr->v6.sin6_scope_id)
910                                 return 0;
911                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
912                         if (!dev)
913                                 return 0;
914                         dev_put(dev);
915                 }
916                 af = opt->pf->af;
917         }
918
919         return af != NULL;
920 }
921
922 /* Fill in Supported Address Type information for INIT and INIT-ACK
923  * chunks.   Note: In the future, we may want to look at sock options
924  * to determine whether a PF_INET6 socket really wants to have IPV4
925  * addresses.
926  * Returns number of addresses supported.
927  */
928 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
929                                       __be16 *types)
930 {
931         types[0] = SCTP_PARAM_IPV6_ADDRESS;
932         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
933                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
934                 return 2;
935         }
936         return 1;
937 }
938
939 static const struct proto_ops inet6_seqpacket_ops = {
940         .family            = PF_INET6,
941         .owner             = THIS_MODULE,
942         .release           = inet6_release,
943         .bind              = inet6_bind,
944         .connect           = inet_dgram_connect,
945         .socketpair        = sock_no_socketpair,
946         .accept            = inet_accept,
947         .getname           = inet6_getname,
948         .poll              = sctp_poll,
949         .ioctl             = inet6_ioctl,
950         .listen            = sctp_inet_listen,
951         .shutdown          = inet_shutdown,
952         .setsockopt        = sock_common_setsockopt,
953         .getsockopt        = sock_common_getsockopt,
954         .sendmsg           = inet_sendmsg,
955         .recvmsg           = sock_common_recvmsg,
956         .mmap              = sock_no_mmap,
957 #ifdef CONFIG_COMPAT
958         .compat_setsockopt = compat_sock_common_setsockopt,
959         .compat_getsockopt = compat_sock_common_getsockopt,
960 #endif
961 };
962
963 static struct inet_protosw sctpv6_seqpacket_protosw = {
964         .type          = SOCK_SEQPACKET,
965         .protocol      = IPPROTO_SCTP,
966         .prot          = &sctpv6_prot,
967         .ops           = &inet6_seqpacket_ops,
968         .capability    = -1,
969         .no_check      = 0,
970         .flags         = SCTP_PROTOSW_FLAG
971 };
972 static struct inet_protosw sctpv6_stream_protosw = {
973         .type          = SOCK_STREAM,
974         .protocol      = IPPROTO_SCTP,
975         .prot          = &sctpv6_prot,
976         .ops           = &inet6_seqpacket_ops,
977         .capability    = -1,
978         .no_check      = 0,
979         .flags         = SCTP_PROTOSW_FLAG,
980 };
981
982 static int sctp6_rcv(struct sk_buff *skb)
983 {
984         return sctp_rcv(skb) ? -1 : 0;
985 }
986
987 static struct inet6_protocol sctpv6_protocol = {
988         .handler      = sctp6_rcv,
989         .err_handler  = sctp_v6_err,
990         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
991 };
992
993 static struct sctp_af sctp_af_inet6 = {
994         .sa_family         = AF_INET6,
995         .sctp_xmit         = sctp_v6_xmit,
996         .setsockopt        = ipv6_setsockopt,
997         .getsockopt        = ipv6_getsockopt,
998         .get_dst           = sctp_v6_get_dst,
999         .get_saddr         = sctp_v6_get_saddr,
1000         .copy_addrlist     = sctp_v6_copy_addrlist,
1001         .from_skb          = sctp_v6_from_skb,
1002         .from_sk           = sctp_v6_from_sk,
1003         .to_sk_saddr       = sctp_v6_to_sk_saddr,
1004         .to_sk_daddr       = sctp_v6_to_sk_daddr,
1005         .from_addr_param   = sctp_v6_from_addr_param,
1006         .to_addr_param     = sctp_v6_to_addr_param,
1007         .dst_saddr         = sctp_v6_dst_saddr,
1008         .cmp_addr          = sctp_v6_cmp_addr,
1009         .scope             = sctp_v6_scope,
1010         .addr_valid        = sctp_v6_addr_valid,
1011         .inaddr_any        = sctp_v6_inaddr_any,
1012         .is_any            = sctp_v6_is_any,
1013         .available         = sctp_v6_available,
1014         .skb_iif           = sctp_v6_skb_iif,
1015         .is_ce             = sctp_v6_is_ce,
1016         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1017         .ecn_capable       = sctp_v6_ecn_capable,
1018         .net_header_len    = sizeof(struct ipv6hdr),
1019         .sockaddr_len      = sizeof(struct sockaddr_in6),
1020 #ifdef CONFIG_COMPAT
1021         .compat_setsockopt = compat_ipv6_setsockopt,
1022         .compat_getsockopt = compat_ipv6_getsockopt,
1023 #endif
1024 };
1025
1026 static struct sctp_pf sctp_pf_inet6 = {
1027         .event_msgname = sctp_inet6_event_msgname,
1028         .skb_msgname   = sctp_inet6_skb_msgname,
1029         .af_supported  = sctp_inet6_af_supported,
1030         .cmp_addr      = sctp_inet6_cmp_addr,
1031         .bind_verify   = sctp_inet6_bind_verify,
1032         .send_verify   = sctp_inet6_send_verify,
1033         .supported_addrs = sctp_inet6_supported_addrs,
1034         .create_accept_sk = sctp_v6_create_accept_sk,
1035         .addr_v4map    = sctp_v6_addr_v4map,
1036         .af            = &sctp_af_inet6,
1037 };
1038
1039 /* Initialize IPv6 support and register with socket layer.  */
1040 void sctp_v6_pf_init(void)
1041 {
1042         /* Register the SCTP specific PF_INET6 functions. */
1043         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1044
1045         /* Register the SCTP specific AF_INET6 functions. */
1046         sctp_register_af(&sctp_af_inet6);
1047 }
1048
1049 void sctp_v6_pf_exit(void)
1050 {
1051         list_del(&sctp_af_inet6.list);
1052 }
1053
1054 /* Initialize IPv6 support and register with socket layer.  */
1055 int sctp_v6_protosw_init(void)
1056 {
1057         int rc;
1058
1059         rc = proto_register(&sctpv6_prot, 1);
1060         if (rc)
1061                 return rc;
1062
1063         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1064         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1065         inet6_register_protosw(&sctpv6_stream_protosw);
1066
1067         return 0;
1068 }
1069
1070 void sctp_v6_protosw_exit(void)
1071 {
1072         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1073         inet6_unregister_protosw(&sctpv6_stream_protosw);
1074         proto_unregister(&sctpv6_prot);
1075 }
1076
1077
1078 /* Register with inet6 layer. */
1079 int sctp_v6_add_protocol(void)
1080 {
1081         /* Register notifier for inet6 address additions/deletions. */
1082         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1083
1084         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1085                 return -EAGAIN;
1086
1087         return 0;
1088 }
1089
1090 /* Unregister with inet6 layer. */
1091 void sctp_v6_del_protocol(void)
1092 {
1093         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1094         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1095 }