[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.
[linux-3.10.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,
320                                    inet6_sk(asoc->base.sk)->srcprefs,
321                                    &saddr->v6.sin6_addr);
322                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
323                                   NIP6(saddr->v6.sin6_addr));
324                 return;
325         }
326
327         scope = sctp_scope(daddr);
328
329         bp = &asoc->base.bind_addr;
330
331         /* Go through the bind address list and find the best source address
332          * that matches the scope of the destination address.
333          */
334         rcu_read_lock();
335         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
336                 if (!laddr->valid)
337                         continue;
338                 if ((laddr->state == SCTP_ADDR_SRC) &&
339                     (laddr->a.sa.sa_family == AF_INET6) &&
340                     (scope <= sctp_scope(&laddr->a))) {
341                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
342                         if (!baddr || (matchlen < bmatchlen)) {
343                                 baddr = &laddr->a;
344                                 matchlen = bmatchlen;
345                         }
346                 }
347         }
348
349         if (baddr) {
350                 memcpy(saddr, baddr, sizeof(union sctp_addr));
351                 SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
352                                   NIP6(saddr->v6.sin6_addr));
353         } else {
354                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
355                        "address for the dest:" NIP6_FMT "\n",
356                        __func__, asoc, NIP6(daddr->v6.sin6_addr));
357         }
358
359         rcu_read_unlock();
360 }
361
362 /* Make a copy of all potential local addresses. */
363 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
364                                   struct net_device *dev)
365 {
366         struct inet6_dev *in6_dev;
367         struct inet6_ifaddr *ifp;
368         struct sctp_sockaddr_entry *addr;
369
370         rcu_read_lock();
371         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
372                 rcu_read_unlock();
373                 return;
374         }
375
376         read_lock_bh(&in6_dev->lock);
377         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
378                 /* Add the address to the local list.  */
379                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
380                 if (addr) {
381                         addr->a.v6.sin6_family = AF_INET6;
382                         addr->a.v6.sin6_port = 0;
383                         addr->a.v6.sin6_addr = ifp->addr;
384                         addr->a.v6.sin6_scope_id = dev->ifindex;
385                         addr->valid = 1;
386                         INIT_LIST_HEAD(&addr->list);
387                         INIT_RCU_HEAD(&addr->rcu);
388                         list_add_tail(&addr->list, addrlist);
389                 }
390         }
391
392         read_unlock_bh(&in6_dev->lock);
393         rcu_read_unlock();
394 }
395
396 /* Initialize a sockaddr_storage from in incoming skb. */
397 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
398                              int is_saddr)
399 {
400         void *from;
401         __be16 *port;
402         struct sctphdr *sh;
403
404         port = &addr->v6.sin6_port;
405         addr->v6.sin6_family = AF_INET6;
406         addr->v6.sin6_flowinfo = 0; /* FIXME */
407         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
408
409         sh = sctp_hdr(skb);
410         if (is_saddr) {
411                 *port  = sh->source;
412                 from = &ipv6_hdr(skb)->saddr;
413         } else {
414                 *port = sh->dest;
415                 from = &ipv6_hdr(skb)->daddr;
416         }
417         ipv6_addr_copy(&addr->v6.sin6_addr, from);
418 }
419
420 /* Initialize an sctp_addr from a socket. */
421 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
422 {
423         addr->v6.sin6_family = AF_INET6;
424         addr->v6.sin6_port = 0;
425         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
426 }
427
428 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
429 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
430 {
431         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
432                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
433                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
434                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
435                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
436                         addr->v4.sin_addr.s_addr;
437         } else {
438                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
439         }
440 }
441
442 /* Initialize sk->sk_daddr from sctp_addr. */
443 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
444 {
445         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
446                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
447                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
448                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
449                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
450         } else {
451                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
452         }
453 }
454
455 /* Initialize a sctp_addr from an address parameter. */
456 static void sctp_v6_from_addr_param(union sctp_addr *addr,
457                                     union sctp_addr_param *param,
458                                     __be16 port, int iif)
459 {
460         addr->v6.sin6_family = AF_INET6;
461         addr->v6.sin6_port = port;
462         addr->v6.sin6_flowinfo = 0; /* BUG */
463         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
464         addr->v6.sin6_scope_id = iif;
465 }
466
467 /* Initialize an address parameter from a sctp_addr and return the length
468  * of the address parameter.
469  */
470 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
471                                  union sctp_addr_param *param)
472 {
473         int length = sizeof(sctp_ipv6addr_param_t);
474
475         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
476         param->v6.param_hdr.length = htons(length);
477         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
478
479         return length;
480 }
481
482 /* Initialize a sctp_addr from a dst_entry. */
483 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
484                               __be16 port)
485 {
486         struct rt6_info *rt = (struct rt6_info *)dst;
487         addr->sa.sa_family = AF_INET6;
488         addr->v6.sin6_port = port;
489         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
490 }
491
492 /* Compare addresses exactly.
493  * v4-mapped-v6 is also in consideration.
494  */
495 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
496                             const union sctp_addr *addr2)
497 {
498         if (addr1->sa.sa_family != addr2->sa.sa_family) {
499                 if (addr1->sa.sa_family == AF_INET &&
500                     addr2->sa.sa_family == AF_INET6 &&
501                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
502                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
503                             addr2->v6.sin6_addr.s6_addr32[3] ==
504                             addr1->v4.sin_addr.s_addr)
505                                 return 1;
506                 }
507                 if (addr2->sa.sa_family == AF_INET &&
508                     addr1->sa.sa_family == AF_INET6 &&
509                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
510                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
511                             addr1->v6.sin6_addr.s6_addr32[3] ==
512                             addr2->v4.sin_addr.s_addr)
513                                 return 1;
514                 }
515                 return 0;
516         }
517         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
518                 return 0;
519         /* If this is a linklocal address, compare the scope_id. */
520         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
521                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
522                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
523                         return 0;
524                 }
525         }
526
527         return 1;
528 }
529
530 /* Initialize addr struct to INADDR_ANY. */
531 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
532 {
533         memset(addr, 0x00, sizeof(union sctp_addr));
534         addr->v6.sin6_family = AF_INET6;
535         addr->v6.sin6_port = port;
536 }
537
538 /* Is this a wildcard address? */
539 static int sctp_v6_is_any(const union sctp_addr *addr)
540 {
541         return ipv6_addr_any(&addr->v6.sin6_addr);
542 }
543
544 /* Should this be available for binding?   */
545 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
546 {
547         int type;
548         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
549
550         type = ipv6_addr_type(in6);
551         if (IPV6_ADDR_ANY == type)
552                 return 1;
553         if (type == IPV6_ADDR_MAPPED) {
554                 if (sp && !sp->v4mapped)
555                         return 0;
556                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
557                         return 0;
558                 sctp_v6_map_v4(addr);
559                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
560         }
561         if (!(type & IPV6_ADDR_UNICAST))
562                 return 0;
563
564         return ipv6_chk_addr(&init_net, in6, NULL, 0);
565 }
566
567 /* This function checks if the address is a valid address to be used for
568  * SCTP.
569  *
570  * Output:
571  * Return 0 - If the address is a non-unicast or an illegal address.
572  * Return 1 - If the address is a unicast.
573  */
574 static int sctp_v6_addr_valid(union sctp_addr *addr,
575                               struct sctp_sock *sp,
576                               const struct sk_buff *skb)
577 {
578         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
579
580         /* Support v4-mapped-v6 address. */
581         if (ret == IPV6_ADDR_MAPPED) {
582                 /* Note: This routine is used in input, so v4-mapped-v6
583                  * are disallowed here when there is no sctp_sock.
584                  */
585                 if (!sp || !sp->v4mapped)
586                         return 0;
587                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
588                         return 0;
589                 sctp_v6_map_v4(addr);
590                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
591         }
592
593         /* Is this a non-unicast address */
594         if (!(ret & IPV6_ADDR_UNICAST))
595                 return 0;
596
597         return 1;
598 }
599
600 /* What is the scope of 'addr'?  */
601 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
602 {
603         int v6scope;
604         sctp_scope_t retval;
605
606         /* The IPv6 scope is really a set of bit fields.
607          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
608          */
609
610         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
611         switch (v6scope) {
612         case IFA_HOST:
613                 retval = SCTP_SCOPE_LOOPBACK;
614                 break;
615         case IFA_LINK:
616                 retval = SCTP_SCOPE_LINK;
617                 break;
618         case IFA_SITE:
619                 retval = SCTP_SCOPE_PRIVATE;
620                 break;
621         default:
622                 retval = SCTP_SCOPE_GLOBAL;
623                 break;
624         }
625
626         return retval;
627 }
628
629 /* Create and initialize a new sk for the socket to be returned by accept(). */
630 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
631                                              struct sctp_association *asoc)
632 {
633         struct inet_sock *inet = inet_sk(sk);
634         struct sock *newsk;
635         struct inet_sock *newinet;
636         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
637         struct sctp6_sock *newsctp6sk;
638
639         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
640         if (!newsk)
641                 goto out;
642
643         sock_init_data(NULL, newsk);
644
645         newsk->sk_type = SOCK_STREAM;
646
647         newsk->sk_prot = sk->sk_prot;
648         newsk->sk_no_check = sk->sk_no_check;
649         newsk->sk_reuse = sk->sk_reuse;
650
651         newsk->sk_destruct = inet_sock_destruct;
652         newsk->sk_family = PF_INET6;
653         newsk->sk_protocol = IPPROTO_SCTP;
654         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
655         newsk->sk_shutdown = sk->sk_shutdown;
656         sock_reset_flag(sk, SOCK_ZAPPED);
657
658         newsctp6sk = (struct sctp6_sock *)newsk;
659         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
660
661         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
662
663         newinet = inet_sk(newsk);
664         newnp = inet6_sk(newsk);
665
666         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
667
668         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
669          * and getpeername().
670          */
671         newinet->sport = inet->sport;
672         newnp->saddr = np->saddr;
673         newnp->rcv_saddr = np->rcv_saddr;
674         newinet->dport = htons(asoc->peer.port);
675         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
676
677         /* Init the ipv4 part of the socket since we can have sockets
678          * using v6 API for ipv4.
679          */
680         newinet->uc_ttl = -1;
681         newinet->mc_loop = 1;
682         newinet->mc_ttl = 1;
683         newinet->mc_index = 0;
684         newinet->mc_list = NULL;
685
686         if (ipv4_config.no_pmtu_disc)
687                 newinet->pmtudisc = IP_PMTUDISC_DONT;
688         else
689                 newinet->pmtudisc = IP_PMTUDISC_WANT;
690
691         sk_refcnt_debug_inc(newsk);
692
693         if (newsk->sk_prot->init(newsk)) {
694                 sk_common_release(newsk);
695                 newsk = NULL;
696         }
697
698 out:
699         return newsk;
700 }
701
702 /* Map v4 address to mapped v6 address */
703 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
704 {
705         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
706                 sctp_v4_map_v6(addr);
707 }
708
709 /* Where did this skb come from?  */
710 static int sctp_v6_skb_iif(const struct sk_buff *skb)
711 {
712         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
713         return opt->iif;
714 }
715
716 /* Was this packet marked by Explicit Congestion Notification? */
717 static int sctp_v6_is_ce(const struct sk_buff *skb)
718 {
719         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
720 }
721
722 /* Dump the v6 addr to the seq file. */
723 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
724 {
725         seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
726 }
727
728 /* Initialize a PF_INET6 socket msg_name. */
729 static void sctp_inet6_msgname(char *msgname, int *addr_len)
730 {
731         struct sockaddr_in6 *sin6;
732
733         sin6 = (struct sockaddr_in6 *)msgname;
734         sin6->sin6_family = AF_INET6;
735         sin6->sin6_flowinfo = 0;
736         sin6->sin6_scope_id = 0; /*FIXME */
737         *addr_len = sizeof(struct sockaddr_in6);
738 }
739
740 /* Initialize a PF_INET msgname from a ulpevent. */
741 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
742                                      char *msgname, int *addrlen)
743 {
744         struct sockaddr_in6 *sin6, *sin6from;
745
746         if (msgname) {
747                 union sctp_addr *addr;
748                 struct sctp_association *asoc;
749
750                 asoc = event->asoc;
751                 sctp_inet6_msgname(msgname, addrlen);
752                 sin6 = (struct sockaddr_in6 *)msgname;
753                 sin6->sin6_port = htons(asoc->peer.port);
754                 addr = &asoc->peer.primary_addr;
755
756                 /* Note: If we go to a common v6 format, this code
757                  * will change.
758                  */
759
760                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
761                 if (sctp_sk(asoc->base.sk)->v4mapped &&
762                     AF_INET == addr->sa.sa_family) {
763                         sctp_v4_map_v6((union sctp_addr *)sin6);
764                         sin6->sin6_addr.s6_addr32[3] =
765                                 addr->v4.sin_addr.s_addr;
766                         return;
767                 }
768
769                 sin6from = &asoc->peer.primary_addr.v6;
770                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
771                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
772                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
773         }
774 }
775
776 /* Initialize a msg_name from an inbound skb. */
777 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
778                                    int *addr_len)
779 {
780         struct sctphdr *sh;
781         struct sockaddr_in6 *sin6;
782
783         if (msgname) {
784                 sctp_inet6_msgname(msgname, addr_len);
785                 sin6 = (struct sockaddr_in6 *)msgname;
786                 sh = sctp_hdr(skb);
787                 sin6->sin6_port = sh->source;
788
789                 /* Map ipv4 address into v4-mapped-on-v6 address. */
790                 if (sctp_sk(skb->sk)->v4mapped &&
791                     ip_hdr(skb)->version == 4) {
792                         sctp_v4_map_v6((union sctp_addr *)sin6);
793                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
794                         return;
795                 }
796
797                 /* Otherwise, just copy the v6 address. */
798                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
799                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
800                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
801                         sin6->sin6_scope_id = ev->iif;
802                 }
803         }
804 }
805
806 /* Do we support this AF? */
807 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
808 {
809         switch (family) {
810         case AF_INET6:
811                 return 1;
812         /* v4-mapped-v6 addresses */
813         case AF_INET:
814                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
815                         return 1;
816         default:
817                 return 0;
818         }
819 }
820
821 /* Address matching with wildcards allowed.  This extra level
822  * of indirection lets us choose whether a PF_INET6 should
823  * disallow any v4 addresses if we so choose.
824  */
825 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
826                                const union sctp_addr *addr2,
827                                struct sctp_sock *opt)
828 {
829         struct sctp_af *af1, *af2;
830
831         af1 = sctp_get_af_specific(addr1->sa.sa_family);
832         af2 = sctp_get_af_specific(addr2->sa.sa_family);
833
834         if (!af1 || !af2)
835                 return 0;
836         /* Today, wildcard AF_INET/AF_INET6. */
837         if (sctp_is_any(addr1) || sctp_is_any(addr2))
838                 return 1;
839
840         if (addr1->sa.sa_family != addr2->sa.sa_family)
841                 return 0;
842
843         return af1->cmp_addr(addr1, addr2);
844 }
845
846 /* Verify that the provided sockaddr looks bindable.   Common verification,
847  * has already been taken care of.
848  */
849 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
850 {
851         struct sctp_af *af;
852
853         /* ASSERT: address family has already been verified. */
854         if (addr->sa.sa_family != AF_INET6)
855                 af = sctp_get_af_specific(addr->sa.sa_family);
856         else {
857                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
858                 struct net_device *dev;
859
860                 if (type & IPV6_ADDR_LINKLOCAL) {
861                         if (!addr->v6.sin6_scope_id)
862                                 return 0;
863                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
864                         if (!dev)
865                                 return 0;
866                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
867                                            dev, 0)) {
868                                 dev_put(dev);
869                                 return 0;
870                         }
871                         dev_put(dev);
872                 }
873                 af = opt->pf->af;
874         }
875         return af->available(addr, opt);
876 }
877
878 /* Verify that the provided sockaddr looks sendable.   Common verification,
879  * has already been taken care of.
880  */
881 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
882 {
883         struct sctp_af *af = NULL;
884
885         /* ASSERT: address family has already been verified. */
886         if (addr->sa.sa_family != AF_INET6)
887                 af = sctp_get_af_specific(addr->sa.sa_family);
888         else {
889                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
890                 struct net_device *dev;
891
892                 if (type & IPV6_ADDR_LINKLOCAL) {
893                         if (!addr->v6.sin6_scope_id)
894                                 return 0;
895                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
896                         if (!dev)
897                                 return 0;
898                         dev_put(dev);
899                 }
900                 af = opt->pf->af;
901         }
902
903         return af != NULL;
904 }
905
906 /* Fill in Supported Address Type information for INIT and INIT-ACK
907  * chunks.   Note: In the future, we may want to look at sock options
908  * to determine whether a PF_INET6 socket really wants to have IPV4
909  * addresses.
910  * Returns number of addresses supported.
911  */
912 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
913                                       __be16 *types)
914 {
915         types[0] = SCTP_PARAM_IPV4_ADDRESS;
916         types[1] = SCTP_PARAM_IPV6_ADDRESS;
917         return 2;
918 }
919
920 static const struct proto_ops inet6_seqpacket_ops = {
921         .family            = PF_INET6,
922         .owner             = THIS_MODULE,
923         .release           = inet6_release,
924         .bind              = inet6_bind,
925         .connect           = inet_dgram_connect,
926         .socketpair        = sock_no_socketpair,
927         .accept            = inet_accept,
928         .getname           = inet6_getname,
929         .poll              = sctp_poll,
930         .ioctl             = inet6_ioctl,
931         .listen            = sctp_inet_listen,
932         .shutdown          = inet_shutdown,
933         .setsockopt        = sock_common_setsockopt,
934         .getsockopt        = sock_common_getsockopt,
935         .sendmsg           = inet_sendmsg,
936         .recvmsg           = sock_common_recvmsg,
937         .mmap              = sock_no_mmap,
938 #ifdef CONFIG_COMPAT
939         .compat_setsockopt = compat_sock_common_setsockopt,
940         .compat_getsockopt = compat_sock_common_getsockopt,
941 #endif
942 };
943
944 static struct inet_protosw sctpv6_seqpacket_protosw = {
945         .type          = SOCK_SEQPACKET,
946         .protocol      = IPPROTO_SCTP,
947         .prot          = &sctpv6_prot,
948         .ops           = &inet6_seqpacket_ops,
949         .capability    = -1,
950         .no_check      = 0,
951         .flags         = SCTP_PROTOSW_FLAG
952 };
953 static struct inet_protosw sctpv6_stream_protosw = {
954         .type          = SOCK_STREAM,
955         .protocol      = IPPROTO_SCTP,
956         .prot          = &sctpv6_prot,
957         .ops           = &inet6_seqpacket_ops,
958         .capability    = -1,
959         .no_check      = 0,
960         .flags         = SCTP_PROTOSW_FLAG,
961 };
962
963 static int sctp6_rcv(struct sk_buff *skb)
964 {
965         return sctp_rcv(skb) ? -1 : 0;
966 }
967
968 static struct inet6_protocol sctpv6_protocol = {
969         .handler      = sctp6_rcv,
970         .err_handler  = sctp_v6_err,
971         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
972 };
973
974 static struct sctp_af sctp_af_inet6 = {
975         .sa_family         = AF_INET6,
976         .sctp_xmit         = sctp_v6_xmit,
977         .setsockopt        = ipv6_setsockopt,
978         .getsockopt        = ipv6_getsockopt,
979         .get_dst           = sctp_v6_get_dst,
980         .get_saddr         = sctp_v6_get_saddr,
981         .copy_addrlist     = sctp_v6_copy_addrlist,
982         .from_skb          = sctp_v6_from_skb,
983         .from_sk           = sctp_v6_from_sk,
984         .to_sk_saddr       = sctp_v6_to_sk_saddr,
985         .to_sk_daddr       = sctp_v6_to_sk_daddr,
986         .from_addr_param   = sctp_v6_from_addr_param,
987         .to_addr_param     = sctp_v6_to_addr_param,
988         .dst_saddr         = sctp_v6_dst_saddr,
989         .cmp_addr          = sctp_v6_cmp_addr,
990         .scope             = sctp_v6_scope,
991         .addr_valid        = sctp_v6_addr_valid,
992         .inaddr_any        = sctp_v6_inaddr_any,
993         .is_any            = sctp_v6_is_any,
994         .available         = sctp_v6_available,
995         .skb_iif           = sctp_v6_skb_iif,
996         .is_ce             = sctp_v6_is_ce,
997         .seq_dump_addr     = sctp_v6_seq_dump_addr,
998         .net_header_len    = sizeof(struct ipv6hdr),
999         .sockaddr_len      = sizeof(struct sockaddr_in6),
1000 #ifdef CONFIG_COMPAT
1001         .compat_setsockopt = compat_ipv6_setsockopt,
1002         .compat_getsockopt = compat_ipv6_getsockopt,
1003 #endif
1004 };
1005
1006 static struct sctp_pf sctp_pf_inet6 = {
1007         .event_msgname = sctp_inet6_event_msgname,
1008         .skb_msgname   = sctp_inet6_skb_msgname,
1009         .af_supported  = sctp_inet6_af_supported,
1010         .cmp_addr      = sctp_inet6_cmp_addr,
1011         .bind_verify   = sctp_inet6_bind_verify,
1012         .send_verify   = sctp_inet6_send_verify,
1013         .supported_addrs = sctp_inet6_supported_addrs,
1014         .create_accept_sk = sctp_v6_create_accept_sk,
1015         .addr_v4map    = sctp_v6_addr_v4map,
1016         .af            = &sctp_af_inet6,
1017 };
1018
1019 /* Initialize IPv6 support and register with socket layer.  */
1020 void sctp_v6_pf_init(void)
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
1029 void sctp_v6_pf_exit(void)
1030 {
1031         list_del(&sctp_af_inet6.list);
1032 }
1033
1034 /* Initialize IPv6 support and register with socket layer.  */
1035 int sctp_v6_protosw_init(void)
1036 {
1037         int rc;
1038
1039         rc = proto_register(&sctpv6_prot, 1);
1040         if (rc)
1041                 return rc;
1042
1043         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1044         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1045         inet6_register_protosw(&sctpv6_stream_protosw);
1046
1047         return 0;
1048 }
1049
1050 void sctp_v6_protosw_exit(void)
1051 {
1052         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1053         inet6_unregister_protosw(&sctpv6_stream_protosw);
1054         proto_unregister(&sctpv6_prot);
1055 }
1056
1057
1058 /* Register with inet6 layer. */
1059 int sctp_v6_add_protocol(void)
1060 {
1061         /* Register notifier for inet6 address additions/deletions. */
1062         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1063
1064         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1065                 return -EAGAIN;
1066
1067         return 0;
1068 }
1069
1070 /* Unregister with inet6 layer. */
1071 void sctp_v6_del_protocol(void)
1072 {
1073         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1074         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1075 }