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Linux/net/sctp/ipv6.c

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  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, see
 25  * <http://www.gnu.org/licenses/>.
 26  *
 27  * Please send any bug reports or fixes you make to the
 28  * email address(es):
 29  *    lksctp developers <linux-sctp@vger.kernel.org>
 30  *
 31  * Written or modified by:
 32  *    Le Yanqun             <yanqun.le@nokia.com>
 33  *    Hui Huang             <hui.huang@nokia.com>
 34  *    La Monte H.P. Yarroll <piggy@acm.org>
 35  *    Sridhar Samudrala     <sri@us.ibm.com>
 36  *    Jon Grimm             <jgrimm@us.ibm.com>
 37  *    Ardelle Fan           <ardelle.fan@intel.com>
 38  *
 39  * Based on:
 40  *      linux/net/ipv6/tcp_ipv6.c
 41  */
 42 
 43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 44 
 45 #include <linux/module.h>
 46 #include <linux/errno.h>
 47 #include <linux/types.h>
 48 #include <linux/socket.h>
 49 #include <linux/sockios.h>
 50 #include <linux/net.h>
 51 #include <linux/in.h>
 52 #include <linux/in6.h>
 53 #include <linux/netdevice.h>
 54 #include <linux/init.h>
 55 #include <linux/ipsec.h>
 56 #include <linux/slab.h>
 57 
 58 #include <linux/ipv6.h>
 59 #include <linux/icmpv6.h>
 60 #include <linux/random.h>
 61 #include <linux/seq_file.h>
 62 
 63 #include <net/protocol.h>
 64 #include <net/ndisc.h>
 65 #include <net/ip.h>
 66 #include <net/ipv6.h>
 67 #include <net/transp_v6.h>
 68 #include <net/addrconf.h>
 69 #include <net/ip6_route.h>
 70 #include <net/inet_common.h>
 71 #include <net/inet_ecn.h>
 72 #include <net/sctp/sctp.h>
 73 
 74 #include <linux/uaccess.h>
 75 
 76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 77                                          union sctp_addr *s2);
 78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 79                               __be16 port);
 80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 81                             const union sctp_addr *addr2);
 82 
 83 /* Event handler for inet6 address addition/deletion events.
 84  * The sctp_local_addr_list needs to be protocted by a spin lock since
 85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
 86  * time and thus corrupt the list.
 87  * The reader side is protected with RCU.
 88  */
 89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
 90                                 void *ptr)
 91 {
 92         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
 93         struct sctp_sockaddr_entry *addr = NULL;
 94         struct sctp_sockaddr_entry *temp;
 95         struct net *net = dev_net(ifa->idev->dev);
 96         int found = 0;
 97 
 98         switch (ev) {
 99         case NETDEV_UP:
100                 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
101                 if (addr) {
102                         addr->a.v6.sin6_family = AF_INET6;
103                         addr->a.v6.sin6_port = 0;
104                         addr->a.v6.sin6_addr = ifa->addr;
105                         addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
106                         addr->valid = 1;
107                         spin_lock_bh(&net->sctp.local_addr_lock);
108                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
109                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
110                         spin_unlock_bh(&net->sctp.local_addr_lock);
111                 }
112                 break;
113         case NETDEV_DOWN:
114                 spin_lock_bh(&net->sctp.local_addr_lock);
115                 list_for_each_entry_safe(addr, temp,
116                                         &net->sctp.local_addr_list, list) {
117                         if (addr->a.sa.sa_family == AF_INET6 &&
118                                         ipv6_addr_equal(&addr->a.v6.sin6_addr,
119                                                 &ifa->addr)) {
120                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
121                                 found = 1;
122                                 addr->valid = 0;
123                                 list_del_rcu(&addr->list);
124                                 break;
125                         }
126                 }
127                 spin_unlock_bh(&net->sctp.local_addr_lock);
128                 if (found)
129                         kfree_rcu(addr, rcu);
130                 break;
131         }
132 
133         return NOTIFY_DONE;
134 }
135 
136 static struct notifier_block sctp_inet6addr_notifier = {
137         .notifier_call = sctp_inet6addr_event,
138 };
139 
140 /* ICMP error handler. */
141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
142                         u8 type, u8 code, int offset, __be32 info)
143 {
144         struct inet6_dev *idev;
145         struct sock *sk;
146         struct sctp_association *asoc;
147         struct sctp_transport *transport;
148         struct ipv6_pinfo *np;
149         __u16 saveip, savesctp;
150         int err;
151         struct net *net = dev_net(skb->dev);
152 
153         idev = in6_dev_get(skb->dev);
154 
155         /* Fix up skb to look at the embedded net header. */
156         saveip   = skb->network_header;
157         savesctp = skb->transport_header;
158         skb_reset_network_header(skb);
159         skb_set_transport_header(skb, offset);
160         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
161         /* Put back, the original pointers. */
162         skb->network_header   = saveip;
163         skb->transport_header = savesctp;
164         if (!sk) {
165                 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
166                 goto out;
167         }
168 
169         /* Warning:  The sock lock is held.  Remember to call
170          * sctp_err_finish!
171          */
172 
173         switch (type) {
174         case ICMPV6_PKT_TOOBIG:
175                 if (ip6_sk_accept_pmtu(sk))
176                         sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
177                 goto out_unlock;
178         case ICMPV6_PARAMPROB:
179                 if (ICMPV6_UNK_NEXTHDR == code) {
180                         sctp_icmp_proto_unreachable(sk, asoc, transport);
181                         goto out_unlock;
182                 }
183                 break;
184         case NDISC_REDIRECT:
185                 sctp_icmp_redirect(sk, transport, skb);
186                 goto out_unlock;
187         default:
188                 break;
189         }
190 
191         np = inet6_sk(sk);
192         icmpv6_err_convert(type, code, &err);
193         if (!sock_owned_by_user(sk) && np->recverr) {
194                 sk->sk_err = err;
195                 sk->sk_error_report(sk);
196         } else {  /* Only an error on timeout */
197                 sk->sk_err_soft = err;
198         }
199 
200 out_unlock:
201         sctp_err_finish(sk, transport);
202 out:
203         if (likely(idev != NULL))
204                 in6_dev_put(idev);
205 }
206 
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 = &transport->fl.u.ip6;
212         int res;
213 
214         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
215                  skb->len, &fl6->saddr, &fl6->daddr);
216 
217         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
218 
219         if (!(transport->param_flags & SPP_PMTUD_ENABLE))
220                 skb->ignore_df = 1;
221 
222         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
223 
224         rcu_read_lock();
225         res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
226                        np->tclass);
227         rcu_read_unlock();
228         return res;
229 }
230 
231 /* Returns the dst cache entry for the given source and destination ip
232  * addresses.
233  */
234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
235                             struct flowi *fl, struct sock *sk)
236 {
237         struct sctp_association *asoc = t->asoc;
238         struct dst_entry *dst = NULL;
239         struct flowi6 *fl6 = &fl->u.ip6;
240         struct sctp_bind_addr *bp;
241         struct ipv6_pinfo *np = inet6_sk(sk);
242         struct sctp_sockaddr_entry *laddr;
243         union sctp_addr *daddr = &t->ipaddr;
244         union sctp_addr dst_saddr;
245         struct in6_addr *final_p, final;
246         enum sctp_scope scope;
247         __u8 matchlen = 0;
248 
249         memset(fl6, 0, sizeof(struct flowi6));
250         fl6->daddr = daddr->v6.sin6_addr;
251         fl6->fl6_dport = daddr->v6.sin6_port;
252         fl6->flowi6_proto = IPPROTO_SCTP;
253         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
254                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
255         else if (asoc)
256                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
257 
258         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
259 
260         if (asoc)
261                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
262 
263         if (saddr) {
264                 fl6->saddr = saddr->v6.sin6_addr;
265                 fl6->fl6_sport = saddr->v6.sin6_port;
266 
267                 pr_debug("src=%pI6 - ", &fl6->saddr);
268         }
269 
270         rcu_read_lock();
271         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
272         rcu_read_unlock();
273 
274         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
275         if (!asoc || saddr)
276                 goto out;
277 
278         bp = &asoc->base.bind_addr;
279         scope = sctp_scope(daddr);
280         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
281          * to see if we can use it.
282          */
283         if (!IS_ERR(dst)) {
284                 /* Walk through the bind address list and look for a bind
285                  * address that matches the source address of the returned dst.
286                  */
287                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
288                 rcu_read_lock();
289                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
290                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
291                             (laddr->state != SCTP_ADDR_SRC &&
292                              !asoc->src_out_of_asoc_ok))
293                                 continue;
294 
295                         /* Do not compare against v4 addrs */
296                         if ((laddr->a.sa.sa_family == AF_INET6) &&
297                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
298                                 rcu_read_unlock();
299                                 goto out;
300                         }
301                 }
302                 rcu_read_unlock();
303                 /* None of the bound addresses match the source address of the
304                  * dst. So release it.
305                  */
306                 dst_release(dst);
307                 dst = NULL;
308         }
309 
310         /* Walk through the bind address list and try to get the
311          * best source address for a given destination.
312          */
313         rcu_read_lock();
314         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
315                 struct dst_entry *bdst;
316                 __u8 bmatchlen;
317 
318                 if (!laddr->valid ||
319                     laddr->state != SCTP_ADDR_SRC ||
320                     laddr->a.sa.sa_family != AF_INET6 ||
321                     scope > sctp_scope(&laddr->a))
322                         continue;
323 
324                 fl6->saddr = laddr->a.v6.sin6_addr;
325                 fl6->fl6_sport = laddr->a.v6.sin6_port;
326                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
327                 bdst = ip6_dst_lookup_flow(sk, fl6, final_p);
328 
329                 if (IS_ERR(bdst))
330                         continue;
331 
332                 if (ipv6_chk_addr(dev_net(bdst->dev),
333                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
334                         if (!IS_ERR_OR_NULL(dst))
335                                 dst_release(dst);
336                         dst = bdst;
337                         break;
338                 }
339 
340                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
341                 if (matchlen > bmatchlen) {
342                         dst_release(bdst);
343                         continue;
344                 }
345 
346                 if (!IS_ERR_OR_NULL(dst))
347                         dst_release(dst);
348                 dst = bdst;
349                 matchlen = bmatchlen;
350         }
351         rcu_read_unlock();
352 
353 out:
354         if (!IS_ERR_OR_NULL(dst)) {
355                 struct rt6_info *rt;
356 
357                 rt = (struct rt6_info *)dst;
358                 t->dst = dst;
359                 t->dst_cookie = rt6_get_cookie(rt);
360                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
361                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
362                          &fl6->saddr);
363         } else {
364                 t->dst = NULL;
365 
366                 pr_debug("no route\n");
367         }
368 }
369 
370 /* Returns the number of consecutive initial bits that match in the 2 ipv6
371  * addresses.
372  */
373 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
374                                          union sctp_addr *s2)
375 {
376         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
377 }
378 
379 /* Fills in the source address(saddr) based on the destination address(daddr)
380  * and asoc's bind address list.
381  */
382 static void sctp_v6_get_saddr(struct sctp_sock *sk,
383                               struct sctp_transport *t,
384                               struct flowi *fl)
385 {
386         struct flowi6 *fl6 = &fl->u.ip6;
387         union sctp_addr *saddr = &t->saddr;
388 
389         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
390 
391         if (t->dst) {
392                 saddr->v6.sin6_family = AF_INET6;
393                 saddr->v6.sin6_addr = fl6->saddr;
394         }
395 }
396 
397 /* Make a copy of all potential local addresses. */
398 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
399                                   struct net_device *dev)
400 {
401         struct inet6_dev *in6_dev;
402         struct inet6_ifaddr *ifp;
403         struct sctp_sockaddr_entry *addr;
404 
405         rcu_read_lock();
406         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
407                 rcu_read_unlock();
408                 return;
409         }
410 
411         read_lock_bh(&in6_dev->lock);
412         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
413                 /* Add the address to the local list.  */
414                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
415                 if (addr) {
416                         addr->a.v6.sin6_family = AF_INET6;
417                         addr->a.v6.sin6_port = 0;
418                         addr->a.v6.sin6_addr = ifp->addr;
419                         addr->a.v6.sin6_scope_id = dev->ifindex;
420                         addr->valid = 1;
421                         INIT_LIST_HEAD(&addr->list);
422                         list_add_tail(&addr->list, addrlist);
423                 }
424         }
425 
426         read_unlock_bh(&in6_dev->lock);
427         rcu_read_unlock();
428 }
429 
430 /* Copy over any ip options */
431 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
432 {
433         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
434         struct ipv6_txoptions *opt;
435 
436         newnp = inet6_sk(newsk);
437 
438         rcu_read_lock();
439         opt = rcu_dereference(np->opt);
440         if (opt) {
441                 opt = ipv6_dup_options(newsk, opt);
442                 if (!opt)
443                         pr_err("%s: Failed to copy ip options\n", __func__);
444         }
445         RCU_INIT_POINTER(newnp->opt, opt);
446         rcu_read_unlock();
447 }
448 
449 /* Account for the IP options */
450 static int sctp_v6_ip_options_len(struct sock *sk)
451 {
452         struct ipv6_pinfo *np = inet6_sk(sk);
453         struct ipv6_txoptions *opt;
454         int len = 0;
455 
456         rcu_read_lock();
457         opt = rcu_dereference(np->opt);
458         if (opt)
459                 len = opt->opt_flen + opt->opt_nflen;
460 
461         rcu_read_unlock();
462         return len;
463 }
464 
465 /* Initialize a sockaddr_storage from in incoming skb. */
466 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
467                              int is_saddr)
468 {
469         /* Always called on head skb, so this is safe */
470         struct sctphdr *sh = sctp_hdr(skb);
471         struct sockaddr_in6 *sa = &addr->v6;
472 
473         addr->v6.sin6_family = AF_INET6;
474         addr->v6.sin6_flowinfo = 0; /* FIXME */
475         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
476 
477         if (is_saddr) {
478                 sa->sin6_port = sh->source;
479                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
480         } else {
481                 sa->sin6_port = sh->dest;
482                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
483         }
484 }
485 
486 /* Initialize an sctp_addr from a socket. */
487 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
488 {
489         addr->v6.sin6_family = AF_INET6;
490         addr->v6.sin6_port = 0;
491         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
492 }
493 
494 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
495 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
496 {
497         if (addr->sa.sa_family == AF_INET) {
498                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
499                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
500                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
501                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
502                         addr->v4.sin_addr.s_addr;
503         } else {
504                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
505         }
506 }
507 
508 /* Initialize sk->sk_daddr from sctp_addr. */
509 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
510 {
511         if (addr->sa.sa_family == AF_INET) {
512                 sk->sk_v6_daddr.s6_addr32[0] = 0;
513                 sk->sk_v6_daddr.s6_addr32[1] = 0;
514                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
515                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
516         } else {
517                 sk->sk_v6_daddr = addr->v6.sin6_addr;
518         }
519 }
520 
521 /* Initialize a sctp_addr from an address parameter. */
522 static void sctp_v6_from_addr_param(union sctp_addr *addr,
523                                     union sctp_addr_param *param,
524                                     __be16 port, int iif)
525 {
526         addr->v6.sin6_family = AF_INET6;
527         addr->v6.sin6_port = port;
528         addr->v6.sin6_flowinfo = 0; /* BUG */
529         addr->v6.sin6_addr = param->v6.addr;
530         addr->v6.sin6_scope_id = iif;
531 }
532 
533 /* Initialize an address parameter from a sctp_addr and return the length
534  * of the address parameter.
535  */
536 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
537                                  union sctp_addr_param *param)
538 {
539         int length = sizeof(struct sctp_ipv6addr_param);
540 
541         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
542         param->v6.param_hdr.length = htons(length);
543         param->v6.addr = addr->v6.sin6_addr;
544 
545         return length;
546 }
547 
548 /* Initialize a sctp_addr from struct in6_addr. */
549 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
550                               __be16 port)
551 {
552         addr->sa.sa_family = AF_INET6;
553         addr->v6.sin6_port = port;
554         addr->v6.sin6_flowinfo = 0;
555         addr->v6.sin6_addr = *saddr;
556         addr->v6.sin6_scope_id = 0;
557 }
558 
559 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
560                               const union sctp_addr *addr2)
561 {
562         if (addr1->sa.sa_family != addr2->sa.sa_family) {
563                 if (addr1->sa.sa_family == AF_INET &&
564                     addr2->sa.sa_family == AF_INET6 &&
565                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
566                     addr2->v6.sin6_addr.s6_addr32[3] ==
567                     addr1->v4.sin_addr.s_addr)
568                         return 1;
569 
570                 if (addr2->sa.sa_family == AF_INET &&
571                     addr1->sa.sa_family == AF_INET6 &&
572                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
573                     addr1->v6.sin6_addr.s6_addr32[3] ==
574                     addr2->v4.sin_addr.s_addr)
575                         return 1;
576 
577                 return 0;
578         }
579 
580         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
581                 return 0;
582 
583         /* If this is a linklocal address, compare the scope_id. */
584         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
585             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
586             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
587                 return 0;
588 
589         return 1;
590 }
591 
592 /* Compare addresses exactly.
593  * v4-mapped-v6 is also in consideration.
594  */
595 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
596                             const union sctp_addr *addr2)
597 {
598         return __sctp_v6_cmp_addr(addr1, addr2) &&
599                addr1->v6.sin6_port == addr2->v6.sin6_port;
600 }
601 
602 /* Initialize addr struct to INADDR_ANY. */
603 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
604 {
605         memset(addr, 0x00, sizeof(union sctp_addr));
606         addr->v6.sin6_family = AF_INET6;
607         addr->v6.sin6_port = port;
608 }
609 
610 /* Is this a wildcard address? */
611 static int sctp_v6_is_any(const union sctp_addr *addr)
612 {
613         return ipv6_addr_any(&addr->v6.sin6_addr);
614 }
615 
616 /* Should this be available for binding?   */
617 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
618 {
619         int type;
620         struct net *net = sock_net(&sp->inet.sk);
621         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
622 
623         type = ipv6_addr_type(in6);
624         if (IPV6_ADDR_ANY == type)
625                 return 1;
626         if (type == IPV6_ADDR_MAPPED) {
627                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
628                         return 0;
629                 sctp_v6_map_v4(addr);
630                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
631         }
632         if (!(type & IPV6_ADDR_UNICAST))
633                 return 0;
634 
635         return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
636                 ipv6_chk_addr(net, in6, NULL, 0);
637 }
638 
639 /* This function checks if the address is a valid address to be used for
640  * SCTP.
641  *
642  * Output:
643  * Return 0 - If the address is a non-unicast or an illegal address.
644  * Return 1 - If the address is a unicast.
645  */
646 static int sctp_v6_addr_valid(union sctp_addr *addr,
647                               struct sctp_sock *sp,
648                               const struct sk_buff *skb)
649 {
650         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
651 
652         /* Support v4-mapped-v6 address. */
653         if (ret == IPV6_ADDR_MAPPED) {
654                 /* Note: This routine is used in input, so v4-mapped-v6
655                  * are disallowed here when there is no sctp_sock.
656                  */
657                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
658                         return 0;
659                 sctp_v6_map_v4(addr);
660                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
661         }
662 
663         /* Is this a non-unicast address */
664         if (!(ret & IPV6_ADDR_UNICAST))
665                 return 0;
666 
667         return 1;
668 }
669 
670 /* What is the scope of 'addr'?  */
671 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
672 {
673         enum sctp_scope retval;
674         int v6scope;
675 
676         /* The IPv6 scope is really a set of bit fields.
677          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
678          */
679 
680         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
681         switch (v6scope) {
682         case IFA_HOST:
683                 retval = SCTP_SCOPE_LOOPBACK;
684                 break;
685         case IFA_LINK:
686                 retval = SCTP_SCOPE_LINK;
687                 break;
688         case IFA_SITE:
689                 retval = SCTP_SCOPE_PRIVATE;
690                 break;
691         default:
692                 retval = SCTP_SCOPE_GLOBAL;
693                 break;
694         }
695 
696         return retval;
697 }
698 
699 /* Create and initialize a new sk for the socket to be returned by accept(). */
700 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
701                                              struct sctp_association *asoc,
702                                              bool kern)
703 {
704         struct sock *newsk;
705         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
706         struct sctp6_sock *newsctp6sk;
707 
708         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
709         if (!newsk)
710                 goto out;
711 
712         sock_init_data(NULL, newsk);
713 
714         sctp_copy_sock(newsk, sk, asoc);
715         sock_reset_flag(sk, SOCK_ZAPPED);
716 
717         newsctp6sk = (struct sctp6_sock *)newsk;
718         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
719 
720         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
721 
722         newnp = inet6_sk(newsk);
723 
724         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
725         newnp->ipv6_mc_list = NULL;
726         newnp->ipv6_ac_list = NULL;
727         newnp->ipv6_fl_list = NULL;
728 
729         sctp_v6_copy_ip_options(sk, newsk);
730 
731         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
732          * and getpeername().
733          */
734         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
735 
736         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
737 
738         sk_refcnt_debug_inc(newsk);
739 
740         if (newsk->sk_prot->init(newsk)) {
741                 sk_common_release(newsk);
742                 newsk = NULL;
743         }
744 
745 out:
746         return newsk;
747 }
748 
749 /* Format a sockaddr for return to user space. This makes sure the return is
750  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
751  */
752 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
753 {
754         if (sp->v4mapped) {
755                 if (addr->sa.sa_family == AF_INET)
756                         sctp_v4_map_v6(addr);
757         } else {
758                 if (addr->sa.sa_family == AF_INET6 &&
759                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
760                         sctp_v6_map_v4(addr);
761         }
762 
763         if (addr->sa.sa_family == AF_INET) {
764                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
765                 return sizeof(struct sockaddr_in);
766         }
767         return sizeof(struct sockaddr_in6);
768 }
769 
770 /* Where did this skb come from?  */
771 static int sctp_v6_skb_iif(const struct sk_buff *skb)
772 {
773         return IP6CB(skb)->iif;
774 }
775 
776 /* Was this packet marked by Explicit Congestion Notification? */
777 static int sctp_v6_is_ce(const struct sk_buff *skb)
778 {
779         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
780 }
781 
782 /* Dump the v6 addr to the seq file. */
783 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
784 {
785         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
786 }
787 
788 static void sctp_v6_ecn_capable(struct sock *sk)
789 {
790         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
791 }
792 
793 /* Initialize a PF_INET msgname from a ulpevent. */
794 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
795                                      char *msgname, int *addrlen)
796 {
797         union sctp_addr *addr;
798         struct sctp_association *asoc;
799         union sctp_addr *paddr;
800 
801         if (!msgname)
802                 return;
803 
804         addr = (union sctp_addr *)msgname;
805         asoc = event->asoc;
806         paddr = &asoc->peer.primary_addr;
807 
808         if (paddr->sa.sa_family == AF_INET) {
809                 addr->v4.sin_family = AF_INET;
810                 addr->v4.sin_port = htons(asoc->peer.port);
811                 addr->v4.sin_addr = paddr->v4.sin_addr;
812         } else {
813                 addr->v6.sin6_family = AF_INET6;
814                 addr->v6.sin6_flowinfo = 0;
815                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
816                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
817                 else
818                         addr->v6.sin6_scope_id = 0;
819                 addr->v6.sin6_port = htons(asoc->peer.port);
820                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
821         }
822 
823         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
824 }
825 
826 /* Initialize a msg_name from an inbound skb. */
827 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
828                                    int *addr_len)
829 {
830         union sctp_addr *addr;
831         struct sctphdr *sh;
832 
833         if (!msgname)
834                 return;
835 
836         addr = (union sctp_addr *)msgname;
837         sh = sctp_hdr(skb);
838 
839         if (ip_hdr(skb)->version == 4) {
840                 addr->v4.sin_family = AF_INET;
841                 addr->v4.sin_port = sh->source;
842                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
843         } else {
844                 addr->v6.sin6_family = AF_INET6;
845                 addr->v6.sin6_flowinfo = 0;
846                 addr->v6.sin6_port = sh->source;
847                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
848                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
849                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
850                 else
851                         addr->v6.sin6_scope_id = 0;
852         }
853 
854         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
855 }
856 
857 /* Do we support this AF? */
858 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
859 {
860         switch (family) {
861         case AF_INET6:
862                 return 1;
863         /* v4-mapped-v6 addresses */
864         case AF_INET:
865                 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
866                         return 1;
867                 /* fallthru */
868         default:
869                 return 0;
870         }
871 }
872 
873 /* Address matching with wildcards allowed.  This extra level
874  * of indirection lets us choose whether a PF_INET6 should
875  * disallow any v4 addresses if we so choose.
876  */
877 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
878                                const union sctp_addr *addr2,
879                                struct sctp_sock *opt)
880 {
881         struct sock *sk = sctp_opt2sk(opt);
882         struct sctp_af *af1, *af2;
883 
884         af1 = sctp_get_af_specific(addr1->sa.sa_family);
885         af2 = sctp_get_af_specific(addr2->sa.sa_family);
886 
887         if (!af1 || !af2)
888                 return 0;
889 
890         /* If the socket is IPv6 only, v4 addrs will not match */
891         if (__ipv6_only_sock(sk) && af1 != af2)
892                 return 0;
893 
894         /* Today, wildcard AF_INET/AF_INET6. */
895         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
896                 return 1;
897 
898         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
899                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
900 
901         return __sctp_v6_cmp_addr(addr1, addr2);
902 }
903 
904 /* Verify that the provided sockaddr looks bindable.   Common verification,
905  * has already been taken care of.
906  */
907 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
908 {
909         struct sctp_af *af;
910 
911         /* ASSERT: address family has already been verified. */
912         if (addr->sa.sa_family != AF_INET6)
913                 af = sctp_get_af_specific(addr->sa.sa_family);
914         else {
915                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
916                 struct net_device *dev;
917 
918                 if (type & IPV6_ADDR_LINKLOCAL) {
919                         struct net *net;
920                         if (!addr->v6.sin6_scope_id)
921                                 return 0;
922                         net = sock_net(&opt->inet.sk);
923                         rcu_read_lock();
924                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
925                         if (!dev || !(opt->inet.freebind ||
926                                       net->ipv6.sysctl.ip_nonlocal_bind ||
927                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
928                                                     dev, 0))) {
929                                 rcu_read_unlock();
930                                 return 0;
931                         }
932                         rcu_read_unlock();
933                 }
934 
935                 af = opt->pf->af;
936         }
937         return af->available(addr, opt);
938 }
939 
940 /* Verify that the provided sockaddr looks sendable.   Common verification,
941  * has already been taken care of.
942  */
943 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
944 {
945         struct sctp_af *af = NULL;
946 
947         /* ASSERT: address family has already been verified. */
948         if (addr->sa.sa_family != AF_INET6)
949                 af = sctp_get_af_specific(addr->sa.sa_family);
950         else {
951                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
952                 struct net_device *dev;
953 
954                 if (type & IPV6_ADDR_LINKLOCAL) {
955                         if (!addr->v6.sin6_scope_id)
956                                 return 0;
957                         rcu_read_lock();
958                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
959                                                    addr->v6.sin6_scope_id);
960                         rcu_read_unlock();
961                         if (!dev)
962                                 return 0;
963                 }
964                 af = opt->pf->af;
965         }
966 
967         return af != NULL;
968 }
969 
970 /* Fill in Supported Address Type information for INIT and INIT-ACK
971  * chunks.   Note: In the future, we may want to look at sock options
972  * to determine whether a PF_INET6 socket really wants to have IPV4
973  * addresses.
974  * Returns number of addresses supported.
975  */
976 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
977                                       __be16 *types)
978 {
979         types[0] = SCTP_PARAM_IPV6_ADDRESS;
980         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
981                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
982                 return 2;
983         }
984         return 1;
985 }
986 
987 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
988 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
989                         int peer)
990 {
991         int rc;
992 
993         rc = inet6_getname(sock, uaddr, peer);
994 
995         if (rc < 0)
996                 return rc;
997 
998         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
999                                           (union sctp_addr *)uaddr);
1000 
1001         return rc;
1002 }
1003 
1004 static const struct proto_ops inet6_seqpacket_ops = {
1005         .family            = PF_INET6,
1006         .owner             = THIS_MODULE,
1007         .release           = inet6_release,
1008         .bind              = inet6_bind,
1009         .connect           = sctp_inet_connect,
1010         .socketpair        = sock_no_socketpair,
1011         .accept            = inet_accept,
1012         .getname           = sctp_getname,
1013         .poll              = sctp_poll,
1014         .ioctl             = inet6_ioctl,
1015         .listen            = sctp_inet_listen,
1016         .shutdown          = inet_shutdown,
1017         .setsockopt        = sock_common_setsockopt,
1018         .getsockopt        = sock_common_getsockopt,
1019         .sendmsg           = inet_sendmsg,
1020         .recvmsg           = inet_recvmsg,
1021         .mmap              = sock_no_mmap,
1022 #ifdef CONFIG_COMPAT
1023         .compat_setsockopt = compat_sock_common_setsockopt,
1024         .compat_getsockopt = compat_sock_common_getsockopt,
1025 #endif
1026 };
1027 
1028 static struct inet_protosw sctpv6_seqpacket_protosw = {
1029         .type          = SOCK_SEQPACKET,
1030         .protocol      = IPPROTO_SCTP,
1031         .prot          = &sctpv6_prot,
1032         .ops           = &inet6_seqpacket_ops,
1033         .flags         = SCTP_PROTOSW_FLAG
1034 };
1035 static struct inet_protosw sctpv6_stream_protosw = {
1036         .type          = SOCK_STREAM,
1037         .protocol      = IPPROTO_SCTP,
1038         .prot          = &sctpv6_prot,
1039         .ops           = &inet6_seqpacket_ops,
1040         .flags         = SCTP_PROTOSW_FLAG,
1041 };
1042 
1043 static int sctp6_rcv(struct sk_buff *skb)
1044 {
1045         return sctp_rcv(skb) ? -1 : 0;
1046 }
1047 
1048 static const struct inet6_protocol sctpv6_protocol = {
1049         .handler      = sctp6_rcv,
1050         .err_handler  = sctp_v6_err,
1051         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1052 };
1053 
1054 static struct sctp_af sctp_af_inet6 = {
1055         .sa_family         = AF_INET6,
1056         .sctp_xmit         = sctp_v6_xmit,
1057         .setsockopt        = ipv6_setsockopt,
1058         .getsockopt        = ipv6_getsockopt,
1059         .get_dst           = sctp_v6_get_dst,
1060         .get_saddr         = sctp_v6_get_saddr,
1061         .copy_addrlist     = sctp_v6_copy_addrlist,
1062         .from_skb          = sctp_v6_from_skb,
1063         .from_sk           = sctp_v6_from_sk,
1064         .from_addr_param   = sctp_v6_from_addr_param,
1065         .to_addr_param     = sctp_v6_to_addr_param,
1066         .cmp_addr          = sctp_v6_cmp_addr,
1067         .scope             = sctp_v6_scope,
1068         .addr_valid        = sctp_v6_addr_valid,
1069         .inaddr_any        = sctp_v6_inaddr_any,
1070         .is_any            = sctp_v6_is_any,
1071         .available         = sctp_v6_available,
1072         .skb_iif           = sctp_v6_skb_iif,
1073         .is_ce             = sctp_v6_is_ce,
1074         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1075         .ecn_capable       = sctp_v6_ecn_capable,
1076         .net_header_len    = sizeof(struct ipv6hdr),
1077         .sockaddr_len      = sizeof(struct sockaddr_in6),
1078         .ip_options_len    = sctp_v6_ip_options_len,
1079 #ifdef CONFIG_COMPAT
1080         .compat_setsockopt = compat_ipv6_setsockopt,
1081         .compat_getsockopt = compat_ipv6_getsockopt,
1082 #endif
1083 };
1084 
1085 static struct sctp_pf sctp_pf_inet6 = {
1086         .event_msgname = sctp_inet6_event_msgname,
1087         .skb_msgname   = sctp_inet6_skb_msgname,
1088         .af_supported  = sctp_inet6_af_supported,
1089         .cmp_addr      = sctp_inet6_cmp_addr,
1090         .bind_verify   = sctp_inet6_bind_verify,
1091         .send_verify   = sctp_inet6_send_verify,
1092         .supported_addrs = sctp_inet6_supported_addrs,
1093         .create_accept_sk = sctp_v6_create_accept_sk,
1094         .addr_to_user  = sctp_v6_addr_to_user,
1095         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1096         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1097         .copy_ip_options = sctp_v6_copy_ip_options,
1098         .af            = &sctp_af_inet6,
1099 };
1100 
1101 /* Initialize IPv6 support and register with socket layer.  */
1102 void sctp_v6_pf_init(void)
1103 {
1104         /* Register the SCTP specific PF_INET6 functions. */
1105         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1106 
1107         /* Register the SCTP specific AF_INET6 functions. */
1108         sctp_register_af(&sctp_af_inet6);
1109 }
1110 
1111 void sctp_v6_pf_exit(void)
1112 {
1113         list_del(&sctp_af_inet6.list);
1114 }
1115 
1116 /* Initialize IPv6 support and register with socket layer.  */
1117 int sctp_v6_protosw_init(void)
1118 {
1119         int rc;
1120 
1121         rc = proto_register(&sctpv6_prot, 1);
1122         if (rc)
1123                 return rc;
1124 
1125         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1126         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1127         inet6_register_protosw(&sctpv6_stream_protosw);
1128 
1129         return 0;
1130 }
1131 
1132 void sctp_v6_protosw_exit(void)
1133 {
1134         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1135         inet6_unregister_protosw(&sctpv6_stream_protosw);
1136         proto_unregister(&sctpv6_prot);
1137 }
1138 
1139 
1140 /* Register with inet6 layer. */
1141 int sctp_v6_add_protocol(void)
1142 {
1143         /* Register notifier for inet6 address additions/deletions. */
1144         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1145 
1146         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1147                 return -EAGAIN;
1148 
1149         return 0;
1150 }
1151 
1152 /* Unregister with inet6 layer. */
1153 void sctp_v6_del_protocol(void)
1154 {
1155         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1156         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1157 }
1158 

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