sctp: Add sysctl support for Auto-ASCONF.
[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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52 #include <linux/module.h>
53 #include <linux/errno.h>
54 #include <linux/types.h>
55 #include <linux/socket.h>
56 #include <linux/sockios.h>
57 #include <linux/net.h>
58 #include <linux/in.h>
59 #include <linux/in6.h>
60 #include <linux/netdevice.h>
61 #include <linux/init.h>
62 #include <linux/ipsec.h>
63 #include <linux/slab.h>
64
65 #include <linux/ipv6.h>
66 #include <linux/icmpv6.h>
67 #include <linux/random.h>
68 #include <linux/seq_file.h>
69
70 #include <net/protocol.h>
71 #include <net/ndisc.h>
72 #include <net/ip.h>
73 #include <net/ipv6.h>
74 #include <net/transp_v6.h>
75 #include <net/addrconf.h>
76 #include <net/ip6_route.h>
77 #include <net/inet_common.h>
78 #include <net/inet_ecn.h>
79 #include <net/sctp/sctp.h>
80
81 #include <asm/uaccess.h>
82
83 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
84                                          union sctp_addr *s2);
85 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
86                               __be16 port);
87 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
88                             const union sctp_addr *addr2);
89
90 /* Event handler for inet6 address addition/deletion events.
91  * The sctp_local_addr_list needs to be protocted by a spin lock since
92  * multiple notifiers (say IPv4 and IPv6) may be running at the same
93  * time and thus corrupt the list.
94  * The reader side is protected with RCU.
95  */
96 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
97                                 void *ptr)
98 {
99         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
100         struct sctp_sockaddr_entry *addr = NULL;
101         struct sctp_sockaddr_entry *temp;
102         int found = 0;
103
104         switch (ev) {
105         case NETDEV_UP:
106                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
107                 if (addr) {
108                         addr->a.v6.sin6_family = AF_INET6;
109                         addr->a.v6.sin6_port = 0;
110                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
111                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
112                         addr->valid = 1;
113                         spin_lock_bh(&sctp_local_addr_lock);
114                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
115                         sctp_addr_wq_mgmt(addr, SCTP_ADDR_NEW);
116                         spin_unlock_bh(&sctp_local_addr_lock);
117                 }
118                 break;
119         case NETDEV_DOWN:
120                 spin_lock_bh(&sctp_local_addr_lock);
121                 list_for_each_entry_safe(addr, temp,
122                                         &sctp_local_addr_list, list) {
123                         if (addr->a.sa.sa_family == AF_INET6 &&
124                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
125                                                 &ifa->addr)) {
126                                 sctp_addr_wq_mgmt(addr, SCTP_ADDR_DEL);
127                                 found = 1;
128                                 addr->valid = 0;
129                                 list_del_rcu(&addr->list);
130                                 break;
131                         }
132                 }
133                 spin_unlock_bh(&sctp_local_addr_lock);
134                 if (found)
135                         kfree_rcu(addr, rcu);
136                 break;
137         }
138
139         return NOTIFY_DONE;
140 }
141
142 static struct notifier_block sctp_inet6addr_notifier = {
143         .notifier_call = sctp_inet6addr_event,
144 };
145
146 /* ICMP error handler. */
147 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
148                              u8 type, u8 code, int offset, __be32 info)
149 {
150         struct inet6_dev *idev;
151         struct sock *sk;
152         struct sctp_association *asoc;
153         struct sctp_transport *transport;
154         struct ipv6_pinfo *np;
155         sk_buff_data_t saveip, savesctp;
156         int err;
157
158         idev = in6_dev_get(skb->dev);
159
160         /* Fix up skb to look at the embedded net header. */
161         saveip   = skb->network_header;
162         savesctp = skb->transport_header;
163         skb_reset_network_header(skb);
164         skb_set_transport_header(skb, offset);
165         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
166         /* Put back, the original pointers. */
167         skb->network_header   = saveip;
168         skb->transport_header = savesctp;
169         if (!sk) {
170                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
171                 goto out;
172         }
173
174         /* Warning:  The sock lock is held.  Remember to call
175          * sctp_err_finish!
176          */
177
178         switch (type) {
179         case ICMPV6_PKT_TOOBIG:
180                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
181                 goto out_unlock;
182         case ICMPV6_PARAMPROB:
183                 if (ICMPV6_UNK_NEXTHDR == code) {
184                         sctp_icmp_proto_unreachable(sk, asoc, transport);
185                         goto out_unlock;
186                 }
187                 break;
188         default:
189                 break;
190         }
191
192         np = inet6_sk(sk);
193         icmpv6_err_convert(type, code, &err);
194         if (!sock_owned_by_user(sk) && np->recverr) {
195                 sk->sk_err = err;
196                 sk->sk_error_report(sk);
197         } else {  /* Only an error on timeout */
198                 sk->sk_err_soft = err;
199         }
200
201 out_unlock:
202         sctp_err_finish(sk, asoc);
203 out:
204         if (likely(idev != NULL))
205                 in6_dev_put(idev);
206 }
207
208 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
209 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
210 {
211         struct sock *sk = skb->sk;
212         struct ipv6_pinfo *np = inet6_sk(sk);
213         struct flowi6 fl6;
214
215         memset(&fl6, 0, sizeof(fl6));
216
217         fl6.flowi6_proto = sk->sk_protocol;
218
219         /* Fill in the dest address from the route entry passed with the skb
220          * and the source address from the transport.
221          */
222         ipv6_addr_copy(&fl6.daddr, &transport->ipaddr.v6.sin6_addr);
223         ipv6_addr_copy(&fl6.saddr, &transport->saddr.v6.sin6_addr);
224
225         fl6.flowlabel = np->flow_label;
226         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
227         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
228                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
229         else
230                 fl6.flowi6_oif = sk->sk_bound_dev_if;
231
232         if (np->opt && np->opt->srcrt) {
233                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
234                 ipv6_addr_copy(&fl6.daddr, rt0->addr);
235         }
236
237         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
238                           __func__, skb, skb->len,
239                           &fl6.saddr, &fl6.daddr);
240
241         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
242
243         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
244                 skb->local_df = 1;
245
246         return ip6_xmit(sk, skb, &fl6, np->opt);
247 }
248
249 /* Returns the dst cache entry for the given source and destination ip
250  * addresses.
251  */
252 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
253                             struct flowi *fl, struct sock *sk)
254 {
255         struct sctp_association *asoc = t->asoc;
256         struct dst_entry *dst = NULL;
257         struct flowi6 *fl6 = &fl->u.ip6;
258         struct sctp_bind_addr *bp;
259         struct sctp_sockaddr_entry *laddr;
260         union sctp_addr *baddr = NULL;
261         union sctp_addr *daddr = &t->ipaddr;
262         union sctp_addr dst_saddr;
263         __u8 matchlen = 0;
264         __u8 bmatchlen;
265         sctp_scope_t scope;
266
267         memset(fl6, 0, sizeof(struct flowi6));
268         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
269         fl6->fl6_dport = daddr->v6.sin6_port;
270         fl6->flowi6_proto = IPPROTO_SCTP;
271         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
272                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
273
274         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
275
276         if (asoc)
277                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
278
279         if (saddr) {
280                 ipv6_addr_copy(&fl6->saddr, &saddr->v6.sin6_addr);
281                 fl6->fl6_sport = saddr->v6.sin6_port;
282                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
283         }
284
285         dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
286         if (!asoc || saddr)
287                 goto out;
288
289         bp = &asoc->base.bind_addr;
290         scope = sctp_scope(daddr);
291         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
292          * to see if we can use it.
293          */
294         if (!IS_ERR(dst)) {
295                 /* Walk through the bind address list and look for a bind
296                  * address that matches the source address of the returned dst.
297                  */
298                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
299                 rcu_read_lock();
300                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
301                         if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
302                                 continue;
303
304                         /* Do not compare against v4 addrs */
305                         if ((laddr->a.sa.sa_family == AF_INET6) &&
306                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
307                                 rcu_read_unlock();
308                                 goto out;
309                         }
310                 }
311                 rcu_read_unlock();
312                 /* None of the bound addresses match the source address of the
313                  * dst. So release it.
314                  */
315                 dst_release(dst);
316                 dst = NULL;
317         }
318
319         /* Walk through the bind address list and try to get the
320          * best source address for a given destination.
321          */
322         rcu_read_lock();
323         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
324                 if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
325                         continue;
326                 if ((laddr->a.sa.sa_family == AF_INET6) &&
327                     (scope <= sctp_scope(&laddr->a))) {
328                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
329                         if (!baddr || (matchlen < bmatchlen)) {
330                                 baddr = &laddr->a;
331                                 matchlen = bmatchlen;
332                         }
333                 }
334         }
335         rcu_read_unlock();
336         if (baddr) {
337                 ipv6_addr_copy(&fl6->saddr, &baddr->v6.sin6_addr);
338                 fl6->fl6_sport = baddr->v6.sin6_port;
339                 dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
340         }
341
342 out:
343         if (!IS_ERR(dst)) {
344                 struct rt6_info *rt;
345                 rt = (struct rt6_info *)dst;
346                 t->dst = dst;
347                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
348                         &rt->rt6i_dst.addr, &fl6->saddr);
349         } else {
350                 t->dst = NULL;
351                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
352         }
353 }
354
355 /* Returns the number of consecutive initial bits that match in the 2 ipv6
356  * addresses.
357  */
358 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
359                                          union sctp_addr *s2)
360 {
361         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
362 }
363
364 /* Fills in the source address(saddr) based on the destination address(daddr)
365  * and asoc's bind address list.
366  */
367 static void sctp_v6_get_saddr(struct sctp_sock *sk,
368                               struct sctp_transport *t,
369                               struct flowi *fl)
370 {
371         struct flowi6 *fl6 = &fl->u.ip6;
372         union sctp_addr *saddr = &t->saddr;
373
374         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
375
376         if (t->dst) {
377                 saddr->v6.sin6_family = AF_INET6;
378                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
379         }
380 }
381
382 /* Make a copy of all potential local addresses. */
383 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
384                                   struct net_device *dev)
385 {
386         struct inet6_dev *in6_dev;
387         struct inet6_ifaddr *ifp;
388         struct sctp_sockaddr_entry *addr;
389
390         rcu_read_lock();
391         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
392                 rcu_read_unlock();
393                 return;
394         }
395
396         read_lock_bh(&in6_dev->lock);
397         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
398                 /* Add the address to the local list.  */
399                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
400                 if (addr) {
401                         addr->a.v6.sin6_family = AF_INET6;
402                         addr->a.v6.sin6_port = 0;
403                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
404                         addr->a.v6.sin6_scope_id = dev->ifindex;
405                         addr->valid = 1;
406                         INIT_LIST_HEAD(&addr->list);
407                         list_add_tail(&addr->list, addrlist);
408                 }
409         }
410
411         read_unlock_bh(&in6_dev->lock);
412         rcu_read_unlock();
413 }
414
415 /* Initialize a sockaddr_storage from in incoming skb. */
416 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
417                              int is_saddr)
418 {
419         void *from;
420         __be16 *port;
421         struct sctphdr *sh;
422
423         port = &addr->v6.sin6_port;
424         addr->v6.sin6_family = AF_INET6;
425         addr->v6.sin6_flowinfo = 0; /* FIXME */
426         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
427
428         sh = sctp_hdr(skb);
429         if (is_saddr) {
430                 *port  = sh->source;
431                 from = &ipv6_hdr(skb)->saddr;
432         } else {
433                 *port = sh->dest;
434                 from = &ipv6_hdr(skb)->daddr;
435         }
436         ipv6_addr_copy(&addr->v6.sin6_addr, from);
437 }
438
439 /* Initialize an sctp_addr from a socket. */
440 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
441 {
442         addr->v6.sin6_family = AF_INET6;
443         addr->v6.sin6_port = 0;
444         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
445 }
446
447 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
448 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
449 {
450         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
451                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
452                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
453                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
454                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
455                         addr->v4.sin_addr.s_addr;
456         } else {
457                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
458         }
459 }
460
461 /* Initialize sk->sk_daddr from sctp_addr. */
462 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
463 {
464         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
465                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
466                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
467                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
468                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
469         } else {
470                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
471         }
472 }
473
474 /* Initialize a sctp_addr from an address parameter. */
475 static void sctp_v6_from_addr_param(union sctp_addr *addr,
476                                     union sctp_addr_param *param,
477                                     __be16 port, int iif)
478 {
479         addr->v6.sin6_family = AF_INET6;
480         addr->v6.sin6_port = port;
481         addr->v6.sin6_flowinfo = 0; /* BUG */
482         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
483         addr->v6.sin6_scope_id = iif;
484 }
485
486 /* Initialize an address parameter from a sctp_addr and return the length
487  * of the address parameter.
488  */
489 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
490                                  union sctp_addr_param *param)
491 {
492         int length = sizeof(sctp_ipv6addr_param_t);
493
494         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
495         param->v6.param_hdr.length = htons(length);
496         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
497
498         return length;
499 }
500
501 /* Initialize a sctp_addr from struct in6_addr. */
502 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
503                               __be16 port)
504 {
505         addr->sa.sa_family = AF_INET6;
506         addr->v6.sin6_port = port;
507         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
508 }
509
510 /* Compare addresses exactly.
511  * v4-mapped-v6 is also in consideration.
512  */
513 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
514                             const union sctp_addr *addr2)
515 {
516         if (addr1->sa.sa_family != addr2->sa.sa_family) {
517                 if (addr1->sa.sa_family == AF_INET &&
518                     addr2->sa.sa_family == AF_INET6 &&
519                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
520                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
521                             addr2->v6.sin6_addr.s6_addr32[3] ==
522                             addr1->v4.sin_addr.s_addr)
523                                 return 1;
524                 }
525                 if (addr2->sa.sa_family == AF_INET &&
526                     addr1->sa.sa_family == AF_INET6 &&
527                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
528                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
529                             addr1->v6.sin6_addr.s6_addr32[3] ==
530                             addr2->v4.sin_addr.s_addr)
531                                 return 1;
532                 }
533                 return 0;
534         }
535         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
536                 return 0;
537         /* If this is a linklocal address, compare the scope_id. */
538         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
539                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
540                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
541                         return 0;
542                 }
543         }
544
545         return 1;
546 }
547
548 /* Initialize addr struct to INADDR_ANY. */
549 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
550 {
551         memset(addr, 0x00, sizeof(union sctp_addr));
552         addr->v6.sin6_family = AF_INET6;
553         addr->v6.sin6_port = port;
554 }
555
556 /* Is this a wildcard address? */
557 static int sctp_v6_is_any(const union sctp_addr *addr)
558 {
559         return ipv6_addr_any(&addr->v6.sin6_addr);
560 }
561
562 /* Should this be available for binding?   */
563 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
564 {
565         int type;
566         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
567
568         type = ipv6_addr_type(in6);
569         if (IPV6_ADDR_ANY == type)
570                 return 1;
571         if (type == IPV6_ADDR_MAPPED) {
572                 if (sp && !sp->v4mapped)
573                         return 0;
574                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
575                         return 0;
576                 sctp_v6_map_v4(addr);
577                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
578         }
579         if (!(type & IPV6_ADDR_UNICAST))
580                 return 0;
581
582         return ipv6_chk_addr(&init_net, in6, NULL, 0);
583 }
584
585 /* This function checks if the address is a valid address to be used for
586  * SCTP.
587  *
588  * Output:
589  * Return 0 - If the address is a non-unicast or an illegal address.
590  * Return 1 - If the address is a unicast.
591  */
592 static int sctp_v6_addr_valid(union sctp_addr *addr,
593                               struct sctp_sock *sp,
594                               const struct sk_buff *skb)
595 {
596         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
597
598         /* Support v4-mapped-v6 address. */
599         if (ret == IPV6_ADDR_MAPPED) {
600                 /* Note: This routine is used in input, so v4-mapped-v6
601                  * are disallowed here when there is no sctp_sock.
602                  */
603                 if (!sp || !sp->v4mapped)
604                         return 0;
605                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
606                         return 0;
607                 sctp_v6_map_v4(addr);
608                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
609         }
610
611         /* Is this a non-unicast address */
612         if (!(ret & IPV6_ADDR_UNICAST))
613                 return 0;
614
615         return 1;
616 }
617
618 /* What is the scope of 'addr'?  */
619 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
620 {
621         int v6scope;
622         sctp_scope_t retval;
623
624         /* The IPv6 scope is really a set of bit fields.
625          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
626          */
627
628         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
629         switch (v6scope) {
630         case IFA_HOST:
631                 retval = SCTP_SCOPE_LOOPBACK;
632                 break;
633         case IFA_LINK:
634                 retval = SCTP_SCOPE_LINK;
635                 break;
636         case IFA_SITE:
637                 retval = SCTP_SCOPE_PRIVATE;
638                 break;
639         default:
640                 retval = SCTP_SCOPE_GLOBAL;
641                 break;
642         }
643
644         return retval;
645 }
646
647 /* Create and initialize a new sk for the socket to be returned by accept(). */
648 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
649                                              struct sctp_association *asoc)
650 {
651         struct sock *newsk;
652         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
653         struct sctp6_sock *newsctp6sk;
654
655         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
656         if (!newsk)
657                 goto out;
658
659         sock_init_data(NULL, newsk);
660
661         sctp_copy_sock(newsk, sk, asoc);
662         sock_reset_flag(sk, SOCK_ZAPPED);
663
664         newsctp6sk = (struct sctp6_sock *)newsk;
665         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
666
667         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
668
669         newnp = inet6_sk(newsk);
670
671         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
672
673         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
674          * and getpeername().
675          */
676         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
677
678         sk_refcnt_debug_inc(newsk);
679
680         if (newsk->sk_prot->init(newsk)) {
681                 sk_common_release(newsk);
682                 newsk = NULL;
683         }
684
685 out:
686         return newsk;
687 }
688
689 /* Map v4 address to mapped v6 address */
690 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
691 {
692         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
693                 sctp_v4_map_v6(addr);
694 }
695
696 /* Where did this skb come from?  */
697 static int sctp_v6_skb_iif(const struct sk_buff *skb)
698 {
699         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
700         return opt->iif;
701 }
702
703 /* Was this packet marked by Explicit Congestion Notification? */
704 static int sctp_v6_is_ce(const struct sk_buff *skb)
705 {
706         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
707 }
708
709 /* Dump the v6 addr to the seq file. */
710 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
711 {
712         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
713 }
714
715 static void sctp_v6_ecn_capable(struct sock *sk)
716 {
717         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
718 }
719
720 /* Initialize a PF_INET6 socket msg_name. */
721 static void sctp_inet6_msgname(char *msgname, int *addr_len)
722 {
723         struct sockaddr_in6 *sin6;
724
725         sin6 = (struct sockaddr_in6 *)msgname;
726         sin6->sin6_family = AF_INET6;
727         sin6->sin6_flowinfo = 0;
728         sin6->sin6_scope_id = 0; /*FIXME */
729         *addr_len = sizeof(struct sockaddr_in6);
730 }
731
732 /* Initialize a PF_INET msgname from a ulpevent. */
733 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
734                                      char *msgname, int *addrlen)
735 {
736         struct sockaddr_in6 *sin6, *sin6from;
737
738         if (msgname) {
739                 union sctp_addr *addr;
740                 struct sctp_association *asoc;
741
742                 asoc = event->asoc;
743                 sctp_inet6_msgname(msgname, addrlen);
744                 sin6 = (struct sockaddr_in6 *)msgname;
745                 sin6->sin6_port = htons(asoc->peer.port);
746                 addr = &asoc->peer.primary_addr;
747
748                 /* Note: If we go to a common v6 format, this code
749                  * will change.
750                  */
751
752                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
753                 if (sctp_sk(asoc->base.sk)->v4mapped &&
754                     AF_INET == addr->sa.sa_family) {
755                         sctp_v4_map_v6((union sctp_addr *)sin6);
756                         sin6->sin6_addr.s6_addr32[3] =
757                                 addr->v4.sin_addr.s_addr;
758                         return;
759                 }
760
761                 sin6from = &asoc->peer.primary_addr.v6;
762                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
763                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
764                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
765         }
766 }
767
768 /* Initialize a msg_name from an inbound skb. */
769 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
770                                    int *addr_len)
771 {
772         struct sctphdr *sh;
773         struct sockaddr_in6 *sin6;
774
775         if (msgname) {
776                 sctp_inet6_msgname(msgname, addr_len);
777                 sin6 = (struct sockaddr_in6 *)msgname;
778                 sh = sctp_hdr(skb);
779                 sin6->sin6_port = sh->source;
780
781                 /* Map ipv4 address into v4-mapped-on-v6 address. */
782                 if (sctp_sk(skb->sk)->v4mapped &&
783                     ip_hdr(skb)->version == 4) {
784                         sctp_v4_map_v6((union sctp_addr *)sin6);
785                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
786                         return;
787                 }
788
789                 /* Otherwise, just copy the v6 address. */
790                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
791                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
792                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
793                         sin6->sin6_scope_id = ev->iif;
794                 }
795         }
796 }
797
798 /* Do we support this AF? */
799 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
800 {
801         switch (family) {
802         case AF_INET6:
803                 return 1;
804         /* v4-mapped-v6 addresses */
805         case AF_INET:
806                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
807                         return 1;
808         default:
809                 return 0;
810         }
811 }
812
813 /* Address matching with wildcards allowed.  This extra level
814  * of indirection lets us choose whether a PF_INET6 should
815  * disallow any v4 addresses if we so choose.
816  */
817 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
818                                const union sctp_addr *addr2,
819                                struct sctp_sock *opt)
820 {
821         struct sctp_af *af1, *af2;
822         struct sock *sk = sctp_opt2sk(opt);
823
824         af1 = sctp_get_af_specific(addr1->sa.sa_family);
825         af2 = sctp_get_af_specific(addr2->sa.sa_family);
826
827         if (!af1 || !af2)
828                 return 0;
829
830         /* If the socket is IPv6 only, v4 addrs will not match */
831         if (__ipv6_only_sock(sk) && af1 != af2)
832                 return 0;
833
834         /* Today, wildcard AF_INET/AF_INET6. */
835         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
836                 return 1;
837
838         if (addr1->sa.sa_family != addr2->sa.sa_family)
839                 return 0;
840
841         return af1->cmp_addr(addr1, addr2);
842 }
843
844 /* Verify that the provided sockaddr looks bindable.   Common verification,
845  * has already been taken care of.
846  */
847 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
848 {
849         struct sctp_af *af;
850
851         /* ASSERT: address family has already been verified. */
852         if (addr->sa.sa_family != AF_INET6)
853                 af = sctp_get_af_specific(addr->sa.sa_family);
854         else {
855                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
856                 struct net_device *dev;
857
858                 if (type & IPV6_ADDR_LINKLOCAL) {
859                         if (!addr->v6.sin6_scope_id)
860                                 return 0;
861                         rcu_read_lock();
862                         dev = dev_get_by_index_rcu(&init_net,
863                                                    addr->v6.sin6_scope_id);
864                         if (!dev ||
865                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
866                                            dev, 0)) {
867                                 rcu_read_unlock();
868                                 return 0;
869                         }
870                         rcu_read_unlock();
871                 } else if (type == IPV6_ADDR_MAPPED) {
872                         if (!opt->v4mapped)
873                                 return 0;
874                 }
875
876                 af = opt->pf->af;
877         }
878         return af->available(addr, opt);
879 }
880
881 /* Verify that the provided sockaddr looks sendable.   Common verification,
882  * has already been taken care of.
883  */
884 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
885 {
886         struct sctp_af *af = NULL;
887
888         /* ASSERT: address family has already been verified. */
889         if (addr->sa.sa_family != AF_INET6)
890                 af = sctp_get_af_specific(addr->sa.sa_family);
891         else {
892                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
893                 struct net_device *dev;
894
895                 if (type & IPV6_ADDR_LINKLOCAL) {
896                         if (!addr->v6.sin6_scope_id)
897                                 return 0;
898                         rcu_read_lock();
899                         dev = dev_get_by_index_rcu(&init_net,
900                                                    addr->v6.sin6_scope_id);
901                         rcu_read_unlock();
902                         if (!dev)
903                                 return 0;
904                 }
905                 af = opt->pf->af;
906         }
907
908         return af != NULL;
909 }
910
911 /* Fill in Supported Address Type information for INIT and INIT-ACK
912  * chunks.   Note: In the future, we may want to look at sock options
913  * to determine whether a PF_INET6 socket really wants to have IPV4
914  * addresses.
915  * Returns number of addresses supported.
916  */
917 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
918                                       __be16 *types)
919 {
920         types[0] = SCTP_PARAM_IPV6_ADDRESS;
921         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
922                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
923                 return 2;
924         }
925         return 1;
926 }
927
928 static const struct proto_ops inet6_seqpacket_ops = {
929         .family            = PF_INET6,
930         .owner             = THIS_MODULE,
931         .release           = inet6_release,
932         .bind              = inet6_bind,
933         .connect           = inet_dgram_connect,
934         .socketpair        = sock_no_socketpair,
935         .accept            = inet_accept,
936         .getname           = inet6_getname,
937         .poll              = sctp_poll,
938         .ioctl             = inet6_ioctl,
939         .listen            = sctp_inet_listen,
940         .shutdown          = inet_shutdown,
941         .setsockopt        = sock_common_setsockopt,
942         .getsockopt        = sock_common_getsockopt,
943         .sendmsg           = inet_sendmsg,
944         .recvmsg           = sock_common_recvmsg,
945         .mmap              = sock_no_mmap,
946 #ifdef CONFIG_COMPAT
947         .compat_setsockopt = compat_sock_common_setsockopt,
948         .compat_getsockopt = compat_sock_common_getsockopt,
949 #endif
950 };
951
952 static struct inet_protosw sctpv6_seqpacket_protosw = {
953         .type          = SOCK_SEQPACKET,
954         .protocol      = IPPROTO_SCTP,
955         .prot          = &sctpv6_prot,
956         .ops           = &inet6_seqpacket_ops,
957         .no_check      = 0,
958         .flags         = SCTP_PROTOSW_FLAG
959 };
960 static struct inet_protosw sctpv6_stream_protosw = {
961         .type          = SOCK_STREAM,
962         .protocol      = IPPROTO_SCTP,
963         .prot          = &sctpv6_prot,
964         .ops           = &inet6_seqpacket_ops,
965         .no_check      = 0,
966         .flags         = SCTP_PROTOSW_FLAG,
967 };
968
969 static int sctp6_rcv(struct sk_buff *skb)
970 {
971         return sctp_rcv(skb) ? -1 : 0;
972 }
973
974 static const struct inet6_protocol sctpv6_protocol = {
975         .handler      = sctp6_rcv,
976         .err_handler  = sctp_v6_err,
977         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
978 };
979
980 static struct sctp_af sctp_af_inet6 = {
981         .sa_family         = AF_INET6,
982         .sctp_xmit         = sctp_v6_xmit,
983         .setsockopt        = ipv6_setsockopt,
984         .getsockopt        = ipv6_getsockopt,
985         .get_dst           = sctp_v6_get_dst,
986         .get_saddr         = sctp_v6_get_saddr,
987         .copy_addrlist     = sctp_v6_copy_addrlist,
988         .from_skb          = sctp_v6_from_skb,
989         .from_sk           = sctp_v6_from_sk,
990         .to_sk_saddr       = sctp_v6_to_sk_saddr,
991         .to_sk_daddr       = sctp_v6_to_sk_daddr,
992         .from_addr_param   = sctp_v6_from_addr_param,
993         .to_addr_param     = sctp_v6_to_addr_param,
994         .cmp_addr          = sctp_v6_cmp_addr,
995         .scope             = sctp_v6_scope,
996         .addr_valid        = sctp_v6_addr_valid,
997         .inaddr_any        = sctp_v6_inaddr_any,
998         .is_any            = sctp_v6_is_any,
999         .available         = sctp_v6_available,
1000         .skb_iif           = sctp_v6_skb_iif,
1001         .is_ce             = sctp_v6_is_ce,
1002         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1003         .ecn_capable       = sctp_v6_ecn_capable,
1004         .net_header_len    = sizeof(struct ipv6hdr),
1005         .sockaddr_len      = sizeof(struct sockaddr_in6),
1006 #ifdef CONFIG_COMPAT
1007         .compat_setsockopt = compat_ipv6_setsockopt,
1008         .compat_getsockopt = compat_ipv6_getsockopt,
1009 #endif
1010 };
1011
1012 static struct sctp_pf sctp_pf_inet6 = {
1013         .event_msgname = sctp_inet6_event_msgname,
1014         .skb_msgname   = sctp_inet6_skb_msgname,
1015         .af_supported  = sctp_inet6_af_supported,
1016         .cmp_addr      = sctp_inet6_cmp_addr,
1017         .bind_verify   = sctp_inet6_bind_verify,
1018         .send_verify   = sctp_inet6_send_verify,
1019         .supported_addrs = sctp_inet6_supported_addrs,
1020         .create_accept_sk = sctp_v6_create_accept_sk,
1021         .addr_v4map    = sctp_v6_addr_v4map,
1022         .af            = &sctp_af_inet6,
1023 };
1024
1025 /* Initialize IPv6 support and register with socket layer.  */
1026 void sctp_v6_pf_init(void)
1027 {
1028         /* Register the SCTP specific PF_INET6 functions. */
1029         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1030
1031         /* Register the SCTP specific AF_INET6 functions. */
1032         sctp_register_af(&sctp_af_inet6);
1033 }
1034
1035 void sctp_v6_pf_exit(void)
1036 {
1037         list_del(&sctp_af_inet6.list);
1038 }
1039
1040 /* Initialize IPv6 support and register with socket layer.  */
1041 int sctp_v6_protosw_init(void)
1042 {
1043         int rc;
1044
1045         rc = proto_register(&sctpv6_prot, 1);
1046         if (rc)
1047                 return rc;
1048
1049         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1050         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1051         inet6_register_protosw(&sctpv6_stream_protosw);
1052
1053         return 0;
1054 }
1055
1056 void sctp_v6_protosw_exit(void)
1057 {
1058         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1059         inet6_unregister_protosw(&sctpv6_stream_protosw);
1060         proto_unregister(&sctpv6_prot);
1061 }
1062
1063
1064 /* Register with inet6 layer. */
1065 int sctp_v6_add_protocol(void)
1066 {
1067         /* Register notifier for inet6 address additions/deletions. */
1068         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1069
1070         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1071                 return -EAGAIN;
1072
1073         return 0;
1074 }
1075
1076 /* Unregister with inet6 layer. */
1077 void sctp_v6_del_protocol(void)
1078 {
1079         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1080         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1081 }