Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.git] / net / sctp / ipv6.c
1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2002, 2004
3  * Copyright (c) 2001 Nokia, Inc.
4  * Copyright (c) 2001 La Monte H.P. Yarroll
5  * Copyright (c) 2002-2003 Intel Corp.
6  *
7  * This file is part of the SCTP kernel implementation
8  *
9  * SCTP over IPv6.
10  *
11  * This SCTP implementation is free software;
12  * you can redistribute it and/or modify it under the terms of
13  * the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * This SCTP implementation is distributed in the hope that it
18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19  *                 ************************
20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21  * See the GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with GNU CC; see the file COPYING.  If not, write to
25  * the Free Software Foundation, 59 Temple Place - Suite 330,
26  * Boston, MA 02111-1307, USA.
27  *
28  * Please send any bug reports or fixes you make to the
29  * email address(es):
30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
31  *
32  * Or submit a bug report through the following website:
33  *    http://www.sf.net/projects/lksctp
34  *
35  * Written or modified by:
36  *    Le Yanqun             <yanqun.le@nokia.com>
37  *    Hui Huang             <hui.huang@nokia.com>
38  *    La Monte H.P. Yarroll <piggy@acm.org>
39  *    Sridhar Samudrala     <sri@us.ibm.com>
40  *    Jon Grimm             <jgrimm@us.ibm.com>
41  *    Ardelle Fan           <ardelle.fan@intel.com>
42  *
43  * Based on:
44  *      linux/net/ipv6/tcp_ipv6.c
45  *
46  * Any bugs reported given to us we will try to fix... any fixes shared will
47  * be incorporated into the next SCTP release.
48  */
49
50 #include <linux/module.h>
51 #include <linux/errno.h>
52 #include <linux/types.h>
53 #include <linux/socket.h>
54 #include <linux/sockios.h>
55 #include <linux/net.h>
56 #include <linux/in.h>
57 #include <linux/in6.h>
58 #include <linux/netdevice.h>
59 #include <linux/init.h>
60 #include <linux/ipsec.h>
61
62 #include <linux/ipv6.h>
63 #include <linux/icmpv6.h>
64 #include <linux/random.h>
65 #include <linux/seq_file.h>
66
67 #include <net/protocol.h>
68 #include <net/ndisc.h>
69 #include <net/ip.h>
70 #include <net/ipv6.h>
71 #include <net/transp_v6.h>
72 #include <net/addrconf.h>
73 #include <net/ip6_route.h>
74 #include <net/inet_common.h>
75 #include <net/inet_ecn.h>
76 #include <net/sctp/sctp.h>
77
78 #include <asm/uaccess.h>
79
80 /* Event handler for inet6 address addition/deletion events.
81  * The sctp_local_addr_list needs to be protocted by a spin lock since
82  * multiple notifiers (say IPv4 and IPv6) may be running at the same
83  * time and thus corrupt the list.
84  * The reader side is protected with RCU.
85  */
86 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
87                                 void *ptr)
88 {
89         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
90         struct sctp_sockaddr_entry *addr = NULL;
91         struct sctp_sockaddr_entry *temp;
92         int found = 0;
93
94         switch (ev) {
95         case NETDEV_UP:
96                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
97                 if (addr) {
98                         addr->a.v6.sin6_family = AF_INET6;
99                         addr->a.v6.sin6_port = 0;
100                         ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
101                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
102                         addr->valid = 1;
103                         spin_lock_bh(&sctp_local_addr_lock);
104                         list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
105                         spin_unlock_bh(&sctp_local_addr_lock);
106                 }
107                 break;
108         case NETDEV_DOWN:
109                 spin_lock_bh(&sctp_local_addr_lock);
110                 list_for_each_entry_safe(addr, temp,
111                                         &sctp_local_addr_list, list) {
112                         if (addr->a.sa.sa_family == AF_INET6 &&
113                                         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                              u8 type, u8 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(dev_net(skb->dev), 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 {
199         struct sock *sk = skb->sk;
200         struct ipv6_pinfo *np = inet6_sk(sk);
201         struct flowi fl;
202
203         memset(&fl, 0, sizeof(fl));
204
205         fl.proto = sk->sk_protocol;
206
207         /* Fill in the dest address from the route entry passed with the skb
208          * and the source address from the transport.
209          */
210         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
211         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
212
213         fl.fl6_flowlabel = np->flow_label;
214         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
215         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
216                 fl.oif = transport->saddr.v6.sin6_scope_id;
217         else
218                 fl.oif = sk->sk_bound_dev_if;
219
220         if (np->opt && np->opt->srcrt) {
221                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
222                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
223         }
224
225         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
226                           __func__, skb, skb->len,
227                           &fl.fl6_src, &fl.fl6_dst);
228
229         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
230
231         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
232                 skb->local_df = 1;
233
234         return ip6_xmit(sk, skb, &fl, np->opt, 0);
235 }
236
237 /* Returns the dst cache entry for the given source and destination ip
238  * addresses.
239  */
240 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
241                                          union sctp_addr *daddr,
242                                          union sctp_addr *saddr)
243 {
244         struct dst_entry *dst;
245         struct flowi fl;
246
247         memset(&fl, 0, sizeof(fl));
248         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
249         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
250                 fl.oif = daddr->v6.sin6_scope_id;
251
252
253         SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl.fl6_dst);
254
255         if (saddr) {
256                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
257                 SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl.fl6_src);
258         }
259
260         dst = ip6_route_output(&init_net, NULL, &fl);
261         if (!dst->error) {
262                 struct rt6_info *rt;
263                 rt = (struct rt6_info *)dst;
264                 SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
265                         &rt->rt6i_dst.addr, &rt->rt6i_src.addr);
266                 return dst;
267         }
268         SCTP_DEBUG_PRINTK("NO ROUTE\n");
269         dst_release(dst);
270         return NULL;
271 }
272
273 /* Returns the number of consecutive initial bits that match in the 2 ipv6
274  * addresses.
275  */
276 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
277                                          union sctp_addr *s2)
278 {
279         struct in6_addr *a1 = &s1->v6.sin6_addr;
280         struct in6_addr *a2 = &s2->v6.sin6_addr;
281         int i, j;
282
283         for (i = 0; i < 4 ; i++) {
284                 __be32 a1xora2;
285
286                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
287
288                 if ((j = fls(ntohl(a1xora2))))
289                         return (i * 32 + 32 - j);
290         }
291
292         return (i*32);
293 }
294
295 /* Fills in the source address(saddr) based on the destination address(daddr)
296  * and asoc's bind address list.
297  */
298 static void sctp_v6_get_saddr(struct sctp_sock *sk,
299                               struct sctp_association *asoc,
300                               struct dst_entry *dst,
301                               union sctp_addr *daddr,
302                               union sctp_addr *saddr)
303 {
304         struct sctp_bind_addr *bp;
305         struct sctp_sockaddr_entry *laddr;
306         sctp_scope_t scope;
307         union sctp_addr *baddr = NULL;
308         __u8 matchlen = 0;
309         __u8 bmatchlen;
310
311         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
312                           __func__, asoc, dst, &daddr->v6.sin6_addr);
313
314         if (!asoc) {
315                 ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
316                                    dst ? ip6_dst_idev(dst)->dev : NULL,
317                                    &daddr->v6.sin6_addr,
318                                    inet6_sk(&sk->inet.sk)->srcprefs,
319                                    &saddr->v6.sin6_addr);
320                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
321                                   &saddr->v6.sin6_addr);
322                 return;
323         }
324
325         scope = sctp_scope(daddr);
326
327         bp = &asoc->base.bind_addr;
328
329         /* Go through the bind address list and find the best source address
330          * that matches the scope of the destination address.
331          */
332         rcu_read_lock();
333         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
334                 if (!laddr->valid)
335                         continue;
336                 if ((laddr->state == SCTP_ADDR_SRC) &&
337                     (laddr->a.sa.sa_family == AF_INET6) &&
338                     (scope <= sctp_scope(&laddr->a))) {
339                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
340                         if (!baddr || (matchlen < bmatchlen)) {
341                                 baddr = &laddr->a;
342                                 matchlen = bmatchlen;
343                         }
344                 }
345         }
346
347         if (baddr) {
348                 memcpy(saddr, baddr, sizeof(union sctp_addr));
349                 SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
350         } else {
351                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
352                        "address for the dest:%pI6\n",
353                        __func__, asoc, &daddr->v6.sin6_addr);
354         }
355
356         rcu_read_unlock();
357 }
358
359 /* Make a copy of all potential local addresses. */
360 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
361                                   struct net_device *dev)
362 {
363         struct inet6_dev *in6_dev;
364         struct inet6_ifaddr *ifp;
365         struct sctp_sockaddr_entry *addr;
366
367         rcu_read_lock();
368         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
369                 rcu_read_unlock();
370                 return;
371         }
372
373         read_lock_bh(&in6_dev->lock);
374         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
375                 /* Add the address to the local list.  */
376                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
377                 if (addr) {
378                         addr->a.v6.sin6_family = AF_INET6;
379                         addr->a.v6.sin6_port = 0;
380                         addr->a.v6.sin6_addr = ifp->addr;
381                         addr->a.v6.sin6_scope_id = dev->ifindex;
382                         addr->valid = 1;
383                         INIT_LIST_HEAD(&addr->list);
384                         INIT_RCU_HEAD(&addr->rcu);
385                         list_add_tail(&addr->list, addrlist);
386                 }
387         }
388
389         read_unlock_bh(&in6_dev->lock);
390         rcu_read_unlock();
391 }
392
393 /* Initialize a sockaddr_storage from in incoming skb. */
394 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
395                              int is_saddr)
396 {
397         void *from;
398         __be16 *port;
399         struct sctphdr *sh;
400
401         port = &addr->v6.sin6_port;
402         addr->v6.sin6_family = AF_INET6;
403         addr->v6.sin6_flowinfo = 0; /* FIXME */
404         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
405
406         sh = sctp_hdr(skb);
407         if (is_saddr) {
408                 *port  = sh->source;
409                 from = &ipv6_hdr(skb)->saddr;
410         } else {
411                 *port = sh->dest;
412                 from = &ipv6_hdr(skb)->daddr;
413         }
414         ipv6_addr_copy(&addr->v6.sin6_addr, from);
415 }
416
417 /* Initialize an sctp_addr from a socket. */
418 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
419 {
420         addr->v6.sin6_family = AF_INET6;
421         addr->v6.sin6_port = 0;
422         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
423 }
424
425 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
426 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
427 {
428         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
429                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
430                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
431                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
432                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
433                         addr->v4.sin_addr.s_addr;
434         } else {
435                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
436         }
437 }
438
439 /* Initialize sk->sk_daddr from sctp_addr. */
440 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
441 {
442         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
443                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
444                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
445                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
446                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
447         } else {
448                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
449         }
450 }
451
452 /* Initialize a sctp_addr from an address parameter. */
453 static void sctp_v6_from_addr_param(union sctp_addr *addr,
454                                     union sctp_addr_param *param,
455                                     __be16 port, int iif)
456 {
457         addr->v6.sin6_family = AF_INET6;
458         addr->v6.sin6_port = port;
459         addr->v6.sin6_flowinfo = 0; /* BUG */
460         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
461         addr->v6.sin6_scope_id = iif;
462 }
463
464 /* Initialize an address parameter from a sctp_addr and return the length
465  * of the address parameter.
466  */
467 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
468                                  union sctp_addr_param *param)
469 {
470         int length = sizeof(sctp_ipv6addr_param_t);
471
472         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
473         param->v6.param_hdr.length = htons(length);
474         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
475
476         return length;
477 }
478
479 /* Initialize a sctp_addr from a dst_entry. */
480 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
481                               __be16 port)
482 {
483         struct rt6_info *rt = (struct rt6_info *)dst;
484         addr->sa.sa_family = AF_INET6;
485         addr->v6.sin6_port = port;
486         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
487 }
488
489 /* Compare addresses exactly.
490  * v4-mapped-v6 is also in consideration.
491  */
492 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
493                             const union sctp_addr *addr2)
494 {
495         if (addr1->sa.sa_family != addr2->sa.sa_family) {
496                 if (addr1->sa.sa_family == AF_INET &&
497                     addr2->sa.sa_family == AF_INET6 &&
498                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
499                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
500                             addr2->v6.sin6_addr.s6_addr32[3] ==
501                             addr1->v4.sin_addr.s_addr)
502                                 return 1;
503                 }
504                 if (addr2->sa.sa_family == AF_INET &&
505                     addr1->sa.sa_family == AF_INET6 &&
506                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
507                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
508                             addr1->v6.sin6_addr.s6_addr32[3] ==
509                             addr2->v4.sin_addr.s_addr)
510                                 return 1;
511                 }
512                 return 0;
513         }
514         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
515                 return 0;
516         /* If this is a linklocal address, compare the scope_id. */
517         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
518                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
519                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
520                         return 0;
521                 }
522         }
523
524         return 1;
525 }
526
527 /* Initialize addr struct to INADDR_ANY. */
528 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
529 {
530         memset(addr, 0x00, sizeof(union sctp_addr));
531         addr->v6.sin6_family = AF_INET6;
532         addr->v6.sin6_port = port;
533 }
534
535 /* Is this a wildcard address? */
536 static int sctp_v6_is_any(const union sctp_addr *addr)
537 {
538         return ipv6_addr_any(&addr->v6.sin6_addr);
539 }
540
541 /* Should this be available for binding?   */
542 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
543 {
544         int type;
545         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
546
547         type = ipv6_addr_type(in6);
548         if (IPV6_ADDR_ANY == type)
549                 return 1;
550         if (type == IPV6_ADDR_MAPPED) {
551                 if (sp && !sp->v4mapped)
552                         return 0;
553                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
554                         return 0;
555                 sctp_v6_map_v4(addr);
556                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
557         }
558         if (!(type & IPV6_ADDR_UNICAST))
559                 return 0;
560
561         return ipv6_chk_addr(&init_net, in6, NULL, 0);
562 }
563
564 /* This function checks if the address is a valid address to be used for
565  * SCTP.
566  *
567  * Output:
568  * Return 0 - If the address is a non-unicast or an illegal address.
569  * Return 1 - If the address is a unicast.
570  */
571 static int sctp_v6_addr_valid(union sctp_addr *addr,
572                               struct sctp_sock *sp,
573                               const struct sk_buff *skb)
574 {
575         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
576
577         /* Support v4-mapped-v6 address. */
578         if (ret == IPV6_ADDR_MAPPED) {
579                 /* Note: This routine is used in input, so v4-mapped-v6
580                  * are disallowed here when there is no sctp_sock.
581                  */
582                 if (!sp || !sp->v4mapped)
583                         return 0;
584                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
585                         return 0;
586                 sctp_v6_map_v4(addr);
587                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
588         }
589
590         /* Is this a non-unicast address */
591         if (!(ret & IPV6_ADDR_UNICAST))
592                 return 0;
593
594         return 1;
595 }
596
597 /* What is the scope of 'addr'?  */
598 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
599 {
600         int v6scope;
601         sctp_scope_t retval;
602
603         /* The IPv6 scope is really a set of bit fields.
604          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
605          */
606
607         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
608         switch (v6scope) {
609         case IFA_HOST:
610                 retval = SCTP_SCOPE_LOOPBACK;
611                 break;
612         case IFA_LINK:
613                 retval = SCTP_SCOPE_LINK;
614                 break;
615         case IFA_SITE:
616                 retval = SCTP_SCOPE_PRIVATE;
617                 break;
618         default:
619                 retval = SCTP_SCOPE_GLOBAL;
620                 break;
621         }
622
623         return retval;
624 }
625
626 /* Create and initialize a new sk for the socket to be returned by accept(). */
627 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
628                                              struct sctp_association *asoc)
629 {
630         struct sock *newsk;
631         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
632         struct sctp6_sock *newsctp6sk;
633
634         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
635         if (!newsk)
636                 goto out;
637
638         sock_init_data(NULL, newsk);
639
640         sctp_copy_sock(newsk, sk, asoc);
641         sock_reset_flag(sk, SOCK_ZAPPED);
642
643         newsctp6sk = (struct sctp6_sock *)newsk;
644         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
645
646         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
647
648         newnp = inet6_sk(newsk);
649
650         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
651
652         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
653          * and getpeername().
654          */
655         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
656
657         sk_refcnt_debug_inc(newsk);
658
659         if (newsk->sk_prot->init(newsk)) {
660                 sk_common_release(newsk);
661                 newsk = NULL;
662         }
663
664 out:
665         return newsk;
666 }
667
668 /* Map v4 address to mapped v6 address */
669 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
670 {
671         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
672                 sctp_v4_map_v6(addr);
673 }
674
675 /* Where did this skb come from?  */
676 static int sctp_v6_skb_iif(const struct sk_buff *skb)
677 {
678         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
679         return opt->iif;
680 }
681
682 /* Was this packet marked by Explicit Congestion Notification? */
683 static int sctp_v6_is_ce(const struct sk_buff *skb)
684 {
685         return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
686 }
687
688 /* Dump the v6 addr to the seq file. */
689 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
690 {
691         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
692 }
693
694 static void sctp_v6_ecn_capable(struct sock *sk)
695 {
696         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
697 }
698
699 /* Initialize a PF_INET6 socket msg_name. */
700 static void sctp_inet6_msgname(char *msgname, int *addr_len)
701 {
702         struct sockaddr_in6 *sin6;
703
704         sin6 = (struct sockaddr_in6 *)msgname;
705         sin6->sin6_family = AF_INET6;
706         sin6->sin6_flowinfo = 0;
707         sin6->sin6_scope_id = 0; /*FIXME */
708         *addr_len = sizeof(struct sockaddr_in6);
709 }
710
711 /* Initialize a PF_INET msgname from a ulpevent. */
712 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
713                                      char *msgname, int *addrlen)
714 {
715         struct sockaddr_in6 *sin6, *sin6from;
716
717         if (msgname) {
718                 union sctp_addr *addr;
719                 struct sctp_association *asoc;
720
721                 asoc = event->asoc;
722                 sctp_inet6_msgname(msgname, addrlen);
723                 sin6 = (struct sockaddr_in6 *)msgname;
724                 sin6->sin6_port = htons(asoc->peer.port);
725                 addr = &asoc->peer.primary_addr;
726
727                 /* Note: If we go to a common v6 format, this code
728                  * will change.
729                  */
730
731                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
732                 if (sctp_sk(asoc->base.sk)->v4mapped &&
733                     AF_INET == addr->sa.sa_family) {
734                         sctp_v4_map_v6((union sctp_addr *)sin6);
735                         sin6->sin6_addr.s6_addr32[3] =
736                                 addr->v4.sin_addr.s_addr;
737                         return;
738                 }
739
740                 sin6from = &asoc->peer.primary_addr.v6;
741                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
742                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
743                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
744         }
745 }
746
747 /* Initialize a msg_name from an inbound skb. */
748 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
749                                    int *addr_len)
750 {
751         struct sctphdr *sh;
752         struct sockaddr_in6 *sin6;
753
754         if (msgname) {
755                 sctp_inet6_msgname(msgname, addr_len);
756                 sin6 = (struct sockaddr_in6 *)msgname;
757                 sh = sctp_hdr(skb);
758                 sin6->sin6_port = sh->source;
759
760                 /* Map ipv4 address into v4-mapped-on-v6 address. */
761                 if (sctp_sk(skb->sk)->v4mapped &&
762                     ip_hdr(skb)->version == 4) {
763                         sctp_v4_map_v6((union sctp_addr *)sin6);
764                         sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
765                         return;
766                 }
767
768                 /* Otherwise, just copy the v6 address. */
769                 ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
770                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
771                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
772                         sin6->sin6_scope_id = ev->iif;
773                 }
774         }
775 }
776
777 /* Do we support this AF? */
778 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
779 {
780         switch (family) {
781         case AF_INET6:
782                 return 1;
783         /* v4-mapped-v6 addresses */
784         case AF_INET:
785                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
786                         return 1;
787         default:
788                 return 0;
789         }
790 }
791
792 /* Address matching with wildcards allowed.  This extra level
793  * of indirection lets us choose whether a PF_INET6 should
794  * disallow any v4 addresses if we so choose.
795  */
796 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
797                                const union sctp_addr *addr2,
798                                struct sctp_sock *opt)
799 {
800         struct sctp_af *af1, *af2;
801         struct sock *sk = sctp_opt2sk(opt);
802
803         af1 = sctp_get_af_specific(addr1->sa.sa_family);
804         af2 = sctp_get_af_specific(addr2->sa.sa_family);
805
806         if (!af1 || !af2)
807                 return 0;
808
809         /* If the socket is IPv6 only, v4 addrs will not match */
810         if (__ipv6_only_sock(sk) && af1 != af2)
811                 return 0;
812
813         /* Today, wildcard AF_INET/AF_INET6. */
814         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
815                 return 1;
816
817         if (addr1->sa.sa_family != addr2->sa.sa_family)
818                 return 0;
819
820         return af1->cmp_addr(addr1, addr2);
821 }
822
823 /* Verify that the provided sockaddr looks bindable.   Common verification,
824  * has already been taken care of.
825  */
826 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
827 {
828         struct sctp_af *af;
829
830         /* ASSERT: address family has already been verified. */
831         if (addr->sa.sa_family != AF_INET6)
832                 af = sctp_get_af_specific(addr->sa.sa_family);
833         else {
834                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
835                 struct net_device *dev;
836
837                 if (type & IPV6_ADDR_LINKLOCAL) {
838                         if (!addr->v6.sin6_scope_id)
839                                 return 0;
840                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
841                         if (!dev)
842                                 return 0;
843                         if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
844                                            dev, 0)) {
845                                 dev_put(dev);
846                                 return 0;
847                         }
848                         dev_put(dev);
849                 } else if (type == IPV6_ADDR_MAPPED) {
850                         if (!opt->v4mapped)
851                                 return 0;
852                 }
853
854                 af = opt->pf->af;
855         }
856         return af->available(addr, opt);
857 }
858
859 /* Verify that the provided sockaddr looks sendable.   Common verification,
860  * has already been taken care of.
861  */
862 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
863 {
864         struct sctp_af *af = NULL;
865
866         /* ASSERT: address family has already been verified. */
867         if (addr->sa.sa_family != AF_INET6)
868                 af = sctp_get_af_specific(addr->sa.sa_family);
869         else {
870                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
871                 struct net_device *dev;
872
873                 if (type & IPV6_ADDR_LINKLOCAL) {
874                         if (!addr->v6.sin6_scope_id)
875                                 return 0;
876                         dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
877                         if (!dev)
878                                 return 0;
879                         dev_put(dev);
880                 }
881                 af = opt->pf->af;
882         }
883
884         return af != NULL;
885 }
886
887 /* Fill in Supported Address Type information for INIT and INIT-ACK
888  * chunks.   Note: In the future, we may want to look at sock options
889  * to determine whether a PF_INET6 socket really wants to have IPV4
890  * addresses.
891  * Returns number of addresses supported.
892  */
893 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
894                                       __be16 *types)
895 {
896         types[0] = SCTP_PARAM_IPV6_ADDRESS;
897         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
898                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
899                 return 2;
900         }
901         return 1;
902 }
903
904 static const struct proto_ops inet6_seqpacket_ops = {
905         .family            = PF_INET6,
906         .owner             = THIS_MODULE,
907         .release           = inet6_release,
908         .bind              = inet6_bind,
909         .connect           = inet_dgram_connect,
910         .socketpair        = sock_no_socketpair,
911         .accept            = inet_accept,
912         .getname           = inet6_getname,
913         .poll              = sctp_poll,
914         .ioctl             = inet6_ioctl,
915         .listen            = sctp_inet_listen,
916         .shutdown          = inet_shutdown,
917         .setsockopt        = sock_common_setsockopt,
918         .getsockopt        = sock_common_getsockopt,
919         .sendmsg           = inet_sendmsg,
920         .recvmsg           = sock_common_recvmsg,
921         .mmap              = sock_no_mmap,
922 #ifdef CONFIG_COMPAT
923         .compat_setsockopt = compat_sock_common_setsockopt,
924         .compat_getsockopt = compat_sock_common_getsockopt,
925 #endif
926 };
927
928 static struct inet_protosw sctpv6_seqpacket_protosw = {
929         .type          = SOCK_SEQPACKET,
930         .protocol      = IPPROTO_SCTP,
931         .prot          = &sctpv6_prot,
932         .ops           = &inet6_seqpacket_ops,
933         .capability    = -1,
934         .no_check      = 0,
935         .flags         = SCTP_PROTOSW_FLAG
936 };
937 static struct inet_protosw sctpv6_stream_protosw = {
938         .type          = SOCK_STREAM,
939         .protocol      = IPPROTO_SCTP,
940         .prot          = &sctpv6_prot,
941         .ops           = &inet6_seqpacket_ops,
942         .capability    = -1,
943         .no_check      = 0,
944         .flags         = SCTP_PROTOSW_FLAG,
945 };
946
947 static int sctp6_rcv(struct sk_buff *skb)
948 {
949         return sctp_rcv(skb) ? -1 : 0;
950 }
951
952 static struct inet6_protocol sctpv6_protocol = {
953         .handler      = sctp6_rcv,
954         .err_handler  = sctp_v6_err,
955         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
956 };
957
958 static struct sctp_af sctp_af_inet6 = {
959         .sa_family         = AF_INET6,
960         .sctp_xmit         = sctp_v6_xmit,
961         .setsockopt        = ipv6_setsockopt,
962         .getsockopt        = ipv6_getsockopt,
963         .get_dst           = sctp_v6_get_dst,
964         .get_saddr         = sctp_v6_get_saddr,
965         .copy_addrlist     = sctp_v6_copy_addrlist,
966         .from_skb          = sctp_v6_from_skb,
967         .from_sk           = sctp_v6_from_sk,
968         .to_sk_saddr       = sctp_v6_to_sk_saddr,
969         .to_sk_daddr       = sctp_v6_to_sk_daddr,
970         .from_addr_param   = sctp_v6_from_addr_param,
971         .to_addr_param     = sctp_v6_to_addr_param,
972         .dst_saddr         = sctp_v6_dst_saddr,
973         .cmp_addr          = sctp_v6_cmp_addr,
974         .scope             = sctp_v6_scope,
975         .addr_valid        = sctp_v6_addr_valid,
976         .inaddr_any        = sctp_v6_inaddr_any,
977         .is_any            = sctp_v6_is_any,
978         .available         = sctp_v6_available,
979         .skb_iif           = sctp_v6_skb_iif,
980         .is_ce             = sctp_v6_is_ce,
981         .seq_dump_addr     = sctp_v6_seq_dump_addr,
982         .ecn_capable       = sctp_v6_ecn_capable,
983         .net_header_len    = sizeof(struct ipv6hdr),
984         .sockaddr_len      = sizeof(struct sockaddr_in6),
985 #ifdef CONFIG_COMPAT
986         .compat_setsockopt = compat_ipv6_setsockopt,
987         .compat_getsockopt = compat_ipv6_getsockopt,
988 #endif
989 };
990
991 static struct sctp_pf sctp_pf_inet6 = {
992         .event_msgname = sctp_inet6_event_msgname,
993         .skb_msgname   = sctp_inet6_skb_msgname,
994         .af_supported  = sctp_inet6_af_supported,
995         .cmp_addr      = sctp_inet6_cmp_addr,
996         .bind_verify   = sctp_inet6_bind_verify,
997         .send_verify   = sctp_inet6_send_verify,
998         .supported_addrs = sctp_inet6_supported_addrs,
999         .create_accept_sk = sctp_v6_create_accept_sk,
1000         .addr_v4map    = sctp_v6_addr_v4map,
1001         .af            = &sctp_af_inet6,
1002 };
1003
1004 /* Initialize IPv6 support and register with socket layer.  */
1005 void sctp_v6_pf_init(void)
1006 {
1007         /* Register the SCTP specific PF_INET6 functions. */
1008         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1009
1010         /* Register the SCTP specific AF_INET6 functions. */
1011         sctp_register_af(&sctp_af_inet6);
1012 }
1013
1014 void sctp_v6_pf_exit(void)
1015 {
1016         list_del(&sctp_af_inet6.list);
1017 }
1018
1019 /* Initialize IPv6 support and register with socket layer.  */
1020 int sctp_v6_protosw_init(void)
1021 {
1022         int rc;
1023
1024         rc = proto_register(&sctpv6_prot, 1);
1025         if (rc)
1026                 return rc;
1027
1028         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1029         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1030         inet6_register_protosw(&sctpv6_stream_protosw);
1031
1032         return 0;
1033 }
1034
1035 void sctp_v6_protosw_exit(void)
1036 {
1037         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1038         inet6_unregister_protosw(&sctpv6_stream_protosw);
1039         proto_unregister(&sctpv6_prot);
1040 }
1041
1042
1043 /* Register with inet6 layer. */
1044 int sctp_v6_add_protocol(void)
1045 {
1046         /* Register notifier for inet6 address additions/deletions. */
1047         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1048
1049         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1050                 return -EAGAIN;
1051
1052         return 0;
1053 }
1054
1055 /* Unregister with inet6 layer. */
1056 void sctp_v6_del_protocol(void)
1057 {
1058         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1059         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1060 }