593c80162913062f6f8c90bcfd716952605c26dd
[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                         spin_unlock_bh(&sctp_local_addr_lock);
116                 }
117                 break;
118         case NETDEV_DOWN:
119                 spin_lock_bh(&sctp_local_addr_lock);
120                 list_for_each_entry_safe(addr, temp,
121                                         &sctp_local_addr_list, list) {
122                         if (addr->a.sa.sa_family == AF_INET6 &&
123                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
124                                                 &ifa->addr)) {
125                                 found = 1;
126                                 addr->valid = 0;
127                                 list_del_rcu(&addr->list);
128                                 break;
129                         }
130                 }
131                 spin_unlock_bh(&sctp_local_addr_lock);
132                 if (found)
133                         call_rcu(&addr->rcu, sctp_local_addr_free);
134                 break;
135         }
136
137         return NOTIFY_DONE;
138 }
139
140 static struct notifier_block sctp_inet6addr_notifier = {
141         .notifier_call = sctp_inet6addr_event,
142 };
143
144 /* ICMP error handler. */
145 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
146                              u8 type, u8 code, int offset, __be32 info)
147 {
148         struct inet6_dev *idev;
149         struct sock *sk;
150         struct sctp_association *asoc;
151         struct sctp_transport *transport;
152         struct ipv6_pinfo *np;
153         sk_buff_data_t saveip, savesctp;
154         int err;
155
156         idev = in6_dev_get(skb->dev);
157
158         /* Fix up skb to look at the embedded net header. */
159         saveip   = skb->network_header;
160         savesctp = skb->transport_header;
161         skb_reset_network_header(skb);
162         skb_set_transport_header(skb, offset);
163         sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
164         /* Put back, the original pointers. */
165         skb->network_header   = saveip;
166         skb->transport_header = savesctp;
167         if (!sk) {
168                 ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
169                 goto out;
170         }
171
172         /* Warning:  The sock lock is held.  Remember to call
173          * sctp_err_finish!
174          */
175
176         switch (type) {
177         case ICMPV6_PKT_TOOBIG:
178                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
179                 goto out_unlock;
180         case ICMPV6_PARAMPROB:
181                 if (ICMPV6_UNK_NEXTHDR == code) {
182                         sctp_icmp_proto_unreachable(sk, asoc, transport);
183                         goto out_unlock;
184                 }
185                 break;
186         default:
187                 break;
188         }
189
190         np = inet6_sk(sk);
191         icmpv6_err_convert(type, code, &err);
192         if (!sock_owned_by_user(sk) && np->recverr) {
193                 sk->sk_err = err;
194                 sk->sk_error_report(sk);
195         } else {  /* Only an error on timeout */
196                 sk->sk_err_soft = err;
197         }
198
199 out_unlock:
200         sctp_err_finish(sk, asoc);
201 out:
202         if (likely(idev != NULL))
203                 in6_dev_put(idev);
204 }
205
206 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
208 {
209         struct sock *sk = skb->sk;
210         struct ipv6_pinfo *np = inet6_sk(sk);
211         struct flowi6 fl6;
212
213         memset(&fl6, 0, sizeof(fl6));
214
215         fl6.flowi6_proto = sk->sk_protocol;
216
217         /* Fill in the dest address from the route entry passed with the skb
218          * and the source address from the transport.
219          */
220         ipv6_addr_copy(&fl6.daddr, &transport->ipaddr.v6.sin6_addr);
221         ipv6_addr_copy(&fl6.saddr, &transport->saddr.v6.sin6_addr);
222
223         fl6.flowlabel = np->flow_label;
224         IP6_ECN_flow_xmit(sk, fl6.flowlabel);
225         if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
226                 fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
227         else
228                 fl6.flowi6_oif = sk->sk_bound_dev_if;
229
230         if (np->opt && np->opt->srcrt) {
231                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
232                 ipv6_addr_copy(&fl6.daddr, rt0->addr);
233         }
234
235         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
236                           __func__, skb, skb->len,
237                           &fl6.saddr, &fl6.daddr);
238
239         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
240
241         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
242                 skb->local_df = 1;
243
244         return ip6_xmit(sk, skb, &fl6, np->opt);
245 }
246
247 /* Returns the dst cache entry for the given source and destination ip
248  * addresses.
249  */
250 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
251                                          union sctp_addr *daddr,
252                                          union sctp_addr *saddr,
253                                          struct flowi *fl,
254                                          struct sock *sk)
255 {
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 dst_saddr;
262         __u8 matchlen = 0;
263         __u8 bmatchlen;
264         sctp_scope_t scope;
265
266         memset(fl6, 0, sizeof(struct flowi6));
267         ipv6_addr_copy(&fl6->daddr, &daddr->v6.sin6_addr);
268         fl6->fl6_dport = daddr->v6.sin6_port;
269         fl6->flowi6_proto = IPPROTO_SCTP;
270         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
271                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
272
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                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
347                         &rt->rt6i_dst.addr, &fl6->saddr);
348                 return dst;
349         }
350         SCTP_DEBUG_PRINTK("NO ROUTE\n");
351         return NULL;
352 }
353
354 /* Returns the number of consecutive initial bits that match in the 2 ipv6
355  * addresses.
356  */
357 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
358                                          union sctp_addr *s2)
359 {
360         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
361 }
362
363 /* Fills in the source address(saddr) based on the destination address(daddr)
364  * and asoc's bind address list.
365  */
366 static void sctp_v6_get_saddr(struct sctp_sock *sk,
367                               struct sctp_transport *t,
368                               union sctp_addr *daddr,
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 daddr:%pI6 ",
375                           __func__, t->asoc, t->dst, &daddr->v6.sin6_addr);
376
377
378         if (t->dst) {
379                 saddr->v6.sin6_family = AF_INET6;
380                 ipv6_addr_copy(&saddr->v6.sin6_addr, &fl6->saddr);
381         }
382 }
383
384 /* Make a copy of all potential local addresses. */
385 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
386                                   struct net_device *dev)
387 {
388         struct inet6_dev *in6_dev;
389         struct inet6_ifaddr *ifp;
390         struct sctp_sockaddr_entry *addr;
391
392         rcu_read_lock();
393         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
394                 rcu_read_unlock();
395                 return;
396         }
397
398         read_lock_bh(&in6_dev->lock);
399         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
400                 /* Add the address to the local list.  */
401                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
402                 if (addr) {
403                         addr->a.v6.sin6_family = AF_INET6;
404                         addr->a.v6.sin6_port = 0;
405                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
406                         addr->a.v6.sin6_scope_id = dev->ifindex;
407                         addr->valid = 1;
408                         INIT_LIST_HEAD(&addr->list);
409                         list_add_tail(&addr->list, addrlist);
410                 }
411         }
412
413         read_unlock_bh(&in6_dev->lock);
414         rcu_read_unlock();
415 }
416
417 /* Initialize a sockaddr_storage from in incoming skb. */
418 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
419                              int is_saddr)
420 {
421         void *from;
422         __be16 *port;
423         struct sctphdr *sh;
424
425         port = &addr->v6.sin6_port;
426         addr->v6.sin6_family = AF_INET6;
427         addr->v6.sin6_flowinfo = 0; /* FIXME */
428         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
429
430         sh = sctp_hdr(skb);
431         if (is_saddr) {
432                 *port  = sh->source;
433                 from = &ipv6_hdr(skb)->saddr;
434         } else {
435                 *port = sh->dest;
436                 from = &ipv6_hdr(skb)->daddr;
437         }
438         ipv6_addr_copy(&addr->v6.sin6_addr, from);
439 }
440
441 /* Initialize an sctp_addr from a socket. */
442 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
443 {
444         addr->v6.sin6_family = AF_INET6;
445         addr->v6.sin6_port = 0;
446         ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
447 }
448
449 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
450 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
451 {
452         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
453                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
454                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
455                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
456                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
457                         addr->v4.sin_addr.s_addr;
458         } else {
459                 ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
460         }
461 }
462
463 /* Initialize sk->sk_daddr from sctp_addr. */
464 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
465 {
466         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
467                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
468                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
469                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
470                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
471         } else {
472                 ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
473         }
474 }
475
476 /* Initialize a sctp_addr from an address parameter. */
477 static void sctp_v6_from_addr_param(union sctp_addr *addr,
478                                     union sctp_addr_param *param,
479                                     __be16 port, int iif)
480 {
481         addr->v6.sin6_family = AF_INET6;
482         addr->v6.sin6_port = port;
483         addr->v6.sin6_flowinfo = 0; /* BUG */
484         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
485         addr->v6.sin6_scope_id = iif;
486 }
487
488 /* Initialize an address parameter from a sctp_addr and return the length
489  * of the address parameter.
490  */
491 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
492                                  union sctp_addr_param *param)
493 {
494         int length = sizeof(sctp_ipv6addr_param_t);
495
496         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
497         param->v6.param_hdr.length = htons(length);
498         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
499
500         return length;
501 }
502
503 /* Initialize a sctp_addr from struct in6_addr. */
504 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
505                               __be16 port)
506 {
507         addr->sa.sa_family = AF_INET6;
508         addr->v6.sin6_port = port;
509         ipv6_addr_copy(&addr->v6.sin6_addr, saddr);
510 }
511
512 /* Compare addresses exactly.
513  * v4-mapped-v6 is also in consideration.
514  */
515 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
516                             const union sctp_addr *addr2)
517 {
518         if (addr1->sa.sa_family != addr2->sa.sa_family) {
519                 if (addr1->sa.sa_family == AF_INET &&
520                     addr2->sa.sa_family == AF_INET6 &&
521                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
522                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
523                             addr2->v6.sin6_addr.s6_addr32[3] ==
524                             addr1->v4.sin_addr.s_addr)
525                                 return 1;
526                 }
527                 if (addr2->sa.sa_family == AF_INET &&
528                     addr1->sa.sa_family == AF_INET6 &&
529                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
530                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
531                             addr1->v6.sin6_addr.s6_addr32[3] ==
532                             addr2->v4.sin_addr.s_addr)
533                                 return 1;
534                 }
535                 return 0;
536         }
537         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
538                 return 0;
539         /* If this is a linklocal address, compare the scope_id. */
540         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
541                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
542                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
543                         return 0;
544                 }
545         }
546
547         return 1;
548 }
549
550 /* Initialize addr struct to INADDR_ANY. */
551 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
552 {
553         memset(addr, 0x00, sizeof(union sctp_addr));
554         addr->v6.sin6_family = AF_INET6;
555         addr->v6.sin6_port = port;
556 }
557
558 /* Is this a wildcard address? */
559 static int sctp_v6_is_any(const union sctp_addr *addr)
560 {
561         return ipv6_addr_any(&addr->v6.sin6_addr);
562 }
563
564 /* Should this be available for binding?   */
565 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
566 {
567         int type;
568         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
569
570         type = ipv6_addr_type(in6);
571         if (IPV6_ADDR_ANY == type)
572                 return 1;
573         if (type == IPV6_ADDR_MAPPED) {
574                 if (sp && !sp->v4mapped)
575                         return 0;
576                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
577                         return 0;
578                 sctp_v6_map_v4(addr);
579                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
580         }
581         if (!(type & IPV6_ADDR_UNICAST))
582                 return 0;
583
584         return ipv6_chk_addr(&init_net, in6, NULL, 0);
585 }
586
587 /* This function checks if the address is a valid address to be used for
588  * SCTP.
589  *
590  * Output:
591  * Return 0 - If the address is a non-unicast or an illegal address.
592  * Return 1 - If the address is a unicast.
593  */
594 static int sctp_v6_addr_valid(union sctp_addr *addr,
595                               struct sctp_sock *sp,
596                               const struct sk_buff *skb)
597 {
598         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
599
600         /* Support v4-mapped-v6 address. */
601         if (ret == IPV6_ADDR_MAPPED) {
602                 /* Note: This routine is used in input, so v4-mapped-v6
603                  * are disallowed here when there is no sctp_sock.
604                  */
605                 if (!sp || !sp->v4mapped)
606                         return 0;
607                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
608                         return 0;
609                 sctp_v6_map_v4(addr);
610                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
611         }
612
613         /* Is this a non-unicast address */
614         if (!(ret & IPV6_ADDR_UNICAST))
615                 return 0;
616
617         return 1;
618 }
619
620 /* What is the scope of 'addr'?  */
621 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
622 {
623         int v6scope;
624         sctp_scope_t retval;
625
626         /* The IPv6 scope is really a set of bit fields.
627          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
628          */
629
630         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
631         switch (v6scope) {
632         case IFA_HOST:
633                 retval = SCTP_SCOPE_LOOPBACK;
634                 break;
635         case IFA_LINK:
636                 retval = SCTP_SCOPE_LINK;
637                 break;
638         case IFA_SITE:
639                 retval = SCTP_SCOPE_PRIVATE;
640                 break;
641         default:
642                 retval = SCTP_SCOPE_GLOBAL;
643                 break;
644         }
645
646         return retval;
647 }
648
649 /* Create and initialize a new sk for the socket to be returned by accept(). */
650 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
651                                              struct sctp_association *asoc)
652 {
653         struct sock *newsk;
654         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
655         struct sctp6_sock *newsctp6sk;
656
657         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
658         if (!newsk)
659                 goto out;
660
661         sock_init_data(NULL, newsk);
662
663         sctp_copy_sock(newsk, sk, asoc);
664         sock_reset_flag(sk, SOCK_ZAPPED);
665
666         newsctp6sk = (struct sctp6_sock *)newsk;
667         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
668
669         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
670
671         newnp = inet6_sk(newsk);
672
673         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
674
675         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
676          * and getpeername().
677          */
678         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
679
680         sk_refcnt_debug_inc(newsk);
681
682         if (newsk->sk_prot->init(newsk)) {
683                 sk_common_release(newsk);
684                 newsk = NULL;
685         }
686
687 out:
688         return newsk;
689 }
690
691 /* Map v4 address to mapped v6 address */
692 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
693 {
694         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
695                 sctp_v4_map_v6(addr);
696 }
697
698 /* Where did this skb come from?  */
699 static int sctp_v6_skb_iif(const struct sk_buff *skb)
700 {
701         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
702         return opt->iif;
703 }
704
705 /* Was this packet marked by Explicit Congestion Notification? */
706 static int sctp_v6_is_ce(const struct sk_buff *skb)
707 {
708         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
709 }
710
711 /* Dump the v6 addr to the seq file. */
712 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
713 {
714         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
715 }
716
717 static void sctp_v6_ecn_capable(struct sock *sk)
718 {
719         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
720 }
721
722 /* Initialize a PF_INET6 socket msg_name. */
723 static void sctp_inet6_msgname(char *msgname, int *addr_len)
724 {
725         struct sockaddr_in6 *sin6;
726
727         sin6 = (struct sockaddr_in6 *)msgname;
728         sin6->sin6_family = AF_INET6;
729         sin6->sin6_flowinfo = 0;
730         sin6->sin6_scope_id = 0; /*FIXME */
731         *addr_len = sizeof(struct sockaddr_in6);
732 }
733
734 /* Initialize a PF_INET msgname from a ulpevent. */
735 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
736                                      char *msgname, int *addrlen)
737 {
738         struct sockaddr_in6 *sin6, *sin6from;
739
740         if (msgname) {
741                 union sctp_addr *addr;
742                 struct sctp_association *asoc;
743
744                 asoc = event->asoc;
745                 sctp_inet6_msgname(msgname, addrlen);
746                 sin6 = (struct sockaddr_in6 *)msgname;
747                 sin6->sin6_port = htons(asoc->peer.port);
748                 addr = &asoc->peer.primary_addr;
749
750                 /* Note: If we go to a common v6 format, this code
751                  * will change.
752                  */
753
754                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
755                 if (sctp_sk(asoc->base.sk)->v4mapped &&
756                     AF_INET == addr->sa.sa_family) {
757                         sctp_v4_map_v6((union sctp_addr *)sin6);
758                         sin6->sin6_addr.s6_addr32[3] =
759                                 addr->v4.sin_addr.s_addr;
760                         return;
761                 }
762
763                 sin6from = &asoc->peer.primary_addr.v6;
764                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
765                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
766                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
767         }
768 }
769
770 /* Initialize a msg_name from an inbound skb. */
771 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
772                                    int *addr_len)
773 {
774         struct sctphdr *sh;
775         struct sockaddr_in6 *sin6;
776
777         if (msgname) {
778                 sctp_inet6_msgname(msgname, addr_len);
779                 sin6 = (struct sockaddr_in6 *)msgname;
780                 sh = sctp_hdr(skb);
781                 sin6->sin6_port = sh->source;
782
783                 /* Map ipv4 address into v4-mapped-on-v6 address. */
784                 if (sctp_sk(skb->sk)->v4mapped &&
785                     ip_hdr(skb)->version == 4) {
786                         sctp_v4_map_v6((union sctp_addr *)sin6);
787                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
788                         return;
789                 }
790
791                 /* Otherwise, just copy the v6 address. */
792                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
793                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
794                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
795                         sin6->sin6_scope_id = ev->iif;
796                 }
797         }
798 }
799
800 /* Do we support this AF? */
801 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
802 {
803         switch (family) {
804         case AF_INET6:
805                 return 1;
806         /* v4-mapped-v6 addresses */
807         case AF_INET:
808                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
809                         return 1;
810         default:
811                 return 0;
812         }
813 }
814
815 /* Address matching with wildcards allowed.  This extra level
816  * of indirection lets us choose whether a PF_INET6 should
817  * disallow any v4 addresses if we so choose.
818  */
819 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
820                                const union sctp_addr *addr2,
821                                struct sctp_sock *opt)
822 {
823         struct sctp_af *af1, *af2;
824         struct sock *sk = sctp_opt2sk(opt);
825
826         af1 = sctp_get_af_specific(addr1->sa.sa_family);
827         af2 = sctp_get_af_specific(addr2->sa.sa_family);
828
829         if (!af1 || !af2)
830                 return 0;
831
832         /* If the socket is IPv6 only, v4 addrs will not match */
833         if (__ipv6_only_sock(sk) && af1 != af2)
834                 return 0;
835
836         /* Today, wildcard AF_INET/AF_INET6. */
837         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, 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                         rcu_read_lock();
864                         dev = dev_get_by_index_rcu(&init_net,
865                                                    addr->v6.sin6_scope_id);
866                         if (!dev ||
867                             !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
868                                            dev, 0)) {
869                                 rcu_read_unlock();
870                                 return 0;
871                         }
872                         rcu_read_unlock();
873                 } else if (type == IPV6_ADDR_MAPPED) {
874                         if (!opt->v4mapped)
875                                 return 0;
876                 }
877
878                 af = opt->pf->af;
879         }
880         return af->available(addr, opt);
881 }
882
883 /* Verify that the provided sockaddr looks sendable.   Common verification,
884  * has already been taken care of.
885  */
886 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
887 {
888         struct sctp_af *af = NULL;
889
890         /* ASSERT: address family has already been verified. */
891         if (addr->sa.sa_family != AF_INET6)
892                 af = sctp_get_af_specific(addr->sa.sa_family);
893         else {
894                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
895                 struct net_device *dev;
896
897                 if (type & IPV6_ADDR_LINKLOCAL) {
898                         if (!addr->v6.sin6_scope_id)
899                                 return 0;
900                         rcu_read_lock();
901                         dev = dev_get_by_index_rcu(&init_net,
902                                                    addr->v6.sin6_scope_id);
903                         rcu_read_unlock();
904                         if (!dev)
905                                 return 0;
906                 }
907                 af = opt->pf->af;
908         }
909
910         return af != NULL;
911 }
912
913 /* Fill in Supported Address Type information for INIT and INIT-ACK
914  * chunks.   Note: In the future, we may want to look at sock options
915  * to determine whether a PF_INET6 socket really wants to have IPV4
916  * addresses.
917  * Returns number of addresses supported.
918  */
919 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
920                                       __be16 *types)
921 {
922         types[0] = SCTP_PARAM_IPV6_ADDRESS;
923         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
924                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
925                 return 2;
926         }
927         return 1;
928 }
929
930 static const struct proto_ops inet6_seqpacket_ops = {
931         .family            = PF_INET6,
932         .owner             = THIS_MODULE,
933         .release           = inet6_release,
934         .bind              = inet6_bind,
935         .connect           = inet_dgram_connect,
936         .socketpair        = sock_no_socketpair,
937         .accept            = inet_accept,
938         .getname           = inet6_getname,
939         .poll              = sctp_poll,
940         .ioctl             = inet6_ioctl,
941         .listen            = sctp_inet_listen,
942         .shutdown          = inet_shutdown,
943         .setsockopt        = sock_common_setsockopt,
944         .getsockopt        = sock_common_getsockopt,
945         .sendmsg           = inet_sendmsg,
946         .recvmsg           = sock_common_recvmsg,
947         .mmap              = sock_no_mmap,
948 #ifdef CONFIG_COMPAT
949         .compat_setsockopt = compat_sock_common_setsockopt,
950         .compat_getsockopt = compat_sock_common_getsockopt,
951 #endif
952 };
953
954 static struct inet_protosw sctpv6_seqpacket_protosw = {
955         .type          = SOCK_SEQPACKET,
956         .protocol      = IPPROTO_SCTP,
957         .prot          = &sctpv6_prot,
958         .ops           = &inet6_seqpacket_ops,
959         .no_check      = 0,
960         .flags         = SCTP_PROTOSW_FLAG
961 };
962 static struct inet_protosw sctpv6_stream_protosw = {
963         .type          = SOCK_STREAM,
964         .protocol      = IPPROTO_SCTP,
965         .prot          = &sctpv6_prot,
966         .ops           = &inet6_seqpacket_ops,
967         .no_check      = 0,
968         .flags         = SCTP_PROTOSW_FLAG,
969 };
970
971 static int sctp6_rcv(struct sk_buff *skb)
972 {
973         return sctp_rcv(skb) ? -1 : 0;
974 }
975
976 static const struct inet6_protocol sctpv6_protocol = {
977         .handler      = sctp6_rcv,
978         .err_handler  = sctp_v6_err,
979         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
980 };
981
982 static struct sctp_af sctp_af_inet6 = {
983         .sa_family         = AF_INET6,
984         .sctp_xmit         = sctp_v6_xmit,
985         .setsockopt        = ipv6_setsockopt,
986         .getsockopt        = ipv6_getsockopt,
987         .get_dst           = sctp_v6_get_dst,
988         .get_saddr         = sctp_v6_get_saddr,
989         .copy_addrlist     = sctp_v6_copy_addrlist,
990         .from_skb          = sctp_v6_from_skb,
991         .from_sk           = sctp_v6_from_sk,
992         .to_sk_saddr       = sctp_v6_to_sk_saddr,
993         .to_sk_daddr       = sctp_v6_to_sk_daddr,
994         .from_addr_param   = sctp_v6_from_addr_param,
995         .to_addr_param     = sctp_v6_to_addr_param,
996         .cmp_addr          = sctp_v6_cmp_addr,
997         .scope             = sctp_v6_scope,
998         .addr_valid        = sctp_v6_addr_valid,
999         .inaddr_any        = sctp_v6_inaddr_any,
1000         .is_any            = sctp_v6_is_any,
1001         .available         = sctp_v6_available,
1002         .skb_iif           = sctp_v6_skb_iif,
1003         .is_ce             = sctp_v6_is_ce,
1004         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1005         .ecn_capable       = sctp_v6_ecn_capable,
1006         .net_header_len    = sizeof(struct ipv6hdr),
1007         .sockaddr_len      = sizeof(struct sockaddr_in6),
1008 #ifdef CONFIG_COMPAT
1009         .compat_setsockopt = compat_ipv6_setsockopt,
1010         .compat_getsockopt = compat_ipv6_getsockopt,
1011 #endif
1012 };
1013
1014 static struct sctp_pf sctp_pf_inet6 = {
1015         .event_msgname = sctp_inet6_event_msgname,
1016         .skb_msgname   = sctp_inet6_skb_msgname,
1017         .af_supported  = sctp_inet6_af_supported,
1018         .cmp_addr      = sctp_inet6_cmp_addr,
1019         .bind_verify   = sctp_inet6_bind_verify,
1020         .send_verify   = sctp_inet6_send_verify,
1021         .supported_addrs = sctp_inet6_supported_addrs,
1022         .create_accept_sk = sctp_v6_create_accept_sk,
1023         .addr_v4map    = sctp_v6_addr_v4map,
1024         .af            = &sctp_af_inet6,
1025 };
1026
1027 /* Initialize IPv6 support and register with socket layer.  */
1028 void sctp_v6_pf_init(void)
1029 {
1030         /* Register the SCTP specific PF_INET6 functions. */
1031         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1032
1033         /* Register the SCTP specific AF_INET6 functions. */
1034         sctp_register_af(&sctp_af_inet6);
1035 }
1036
1037 void sctp_v6_pf_exit(void)
1038 {
1039         list_del(&sctp_af_inet6.list);
1040 }
1041
1042 /* Initialize IPv6 support and register with socket layer.  */
1043 int sctp_v6_protosw_init(void)
1044 {
1045         int rc;
1046
1047         rc = proto_register(&sctpv6_prot, 1);
1048         if (rc)
1049                 return rc;
1050
1051         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1052         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1053         inet6_register_protosw(&sctpv6_stream_protosw);
1054
1055         return 0;
1056 }
1057
1058 void sctp_v6_protosw_exit(void)
1059 {
1060         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1061         inet6_unregister_protosw(&sctpv6_stream_protosw);
1062         proto_unregister(&sctpv6_prot);
1063 }
1064
1065
1066 /* Register with inet6 layer. */
1067 int sctp_v6_add_protocol(void)
1068 {
1069         /* Register notifier for inet6 address additions/deletions. */
1070         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1071
1072         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1073                 return -EAGAIN;
1074
1075         return 0;
1076 }
1077
1078 /* Unregister with inet6 layer. */
1079 void sctp_v6_del_protocol(void)
1080 {
1081         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1082         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1083 }