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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, 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 <[email protected]>
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 <[email protected]>
37  * Hui Huang <[email protected]>
38  * La Monte H.P. Yarroll <[email protected]>
39  * Sridhar Samudrala <[email protected]>
40  * Jon Grimm <[email protected]>
41  * Ardelle Fan <[email protected]>
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  struct net *net = dev_net(ifa->idev->dev);
103  int found = 0;
104 
105  switch (ev) {
106  case NETDEV_UP:
107  addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
108  if (addr) {
109  addr->a.v6.sin6_family = AF_INET6;
110  addr->a.v6.sin6_port = 0;
111  addr->a.v6.sin6_addr = ifa->addr;
112  addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
113  addr->valid = 1;
114  spin_lock_bh(&net->sctp.local_addr_lock);
115  list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
116  sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
117  spin_unlock_bh(&net->sctp.local_addr_lock);
118  }
119  break;
120  case NETDEV_DOWN:
121  spin_lock_bh(&net->sctp.local_addr_lock);
122  list_for_each_entry_safe(addr, temp,
123  &net->sctp.local_addr_list, list) {
124  if (addr->a.sa.sa_family == AF_INET6 &&
125  ipv6_addr_equal(&addr->a.v6.sin6_addr,
126  &ifa->addr)) {
127  sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
128  found = 1;
129  addr->valid = 0;
130  list_del_rcu(&addr->list);
131  break;
132  }
133  }
134  spin_unlock_bh(&net->sctp.local_addr_lock);
135  if (found)
136  kfree_rcu(addr, rcu);
137  break;
138  }
139 
140  return NOTIFY_DONE;
141 }
142 
143 static struct notifier_block sctp_inet6addr_notifier = {
144  .notifier_call = sctp_inet6addr_event,
145 };
146 
147 /* ICMP error handler. */
149  u8 type, u8 code, int offset, __be32 info)
150 {
151  struct inet6_dev *idev;
152  struct sock *sk;
153  struct sctp_association *asoc;
154  struct sctp_transport *transport;
155  struct ipv6_pinfo *np;
156  sk_buff_data_t saveip, savesctp;
157  int err;
158  struct net *net = dev_net(skb->dev);
159 
160  idev = in6_dev_get(skb->dev);
161 
162  /* Fix up skb to look at the embedded net header. */
163  saveip = skb->network_header;
164  savesctp = skb->transport_header;
165  skb_reset_network_header(skb);
166  skb_set_transport_header(skb, offset);
167  sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
168  /* Put back, the original pointers. */
169  skb->network_header = saveip;
170  skb->transport_header = savesctp;
171  if (!sk) {
173  goto out;
174  }
175 
176  /* Warning: The sock lock is held. Remember to call
177  * sctp_err_finish!
178  */
179 
180  switch (type) {
181  case ICMPV6_PKT_TOOBIG:
182  sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
183  goto out_unlock;
184  case ICMPV6_PARAMPROB:
185  if (ICMPV6_UNK_NEXTHDR == code) {
186  sctp_icmp_proto_unreachable(sk, asoc, transport);
187  goto out_unlock;
188  }
189  break;
190  case NDISC_REDIRECT:
191  sctp_icmp_redirect(sk, transport, skb);
192  break;
193  default:
194  break;
195  }
196 
197  np = inet6_sk(sk);
198  icmpv6_err_convert(type, code, &err);
199  if (!sock_owned_by_user(sk) && np->recverr) {
200  sk->sk_err = err;
201  sk->sk_error_report(sk);
202  } else { /* Only an error on timeout */
203  sk->sk_err_soft = err;
204  }
205 
206 out_unlock:
207  sctp_err_finish(sk, asoc);
208 out:
209  if (likely(idev != NULL))
210  in6_dev_put(idev);
211 }
212 
213 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
214 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
215 {
216  struct sock *sk = skb->sk;
217  struct ipv6_pinfo *np = inet6_sk(sk);
218  struct flowi6 fl6;
219 
220  memset(&fl6, 0, sizeof(fl6));
221 
222  fl6.flowi6_proto = sk->sk_protocol;
223 
224  /* Fill in the dest address from the route entry passed with the skb
225  * and the source address from the transport.
226  */
227  fl6.daddr = transport->ipaddr.v6.sin6_addr;
228  fl6.saddr = transport->saddr.v6.sin6_addr;
229 
230  fl6.flowlabel = np->flow_label;
231  IP6_ECN_flow_xmit(sk, fl6.flowlabel);
232  if (ipv6_addr_type(&fl6.saddr) & IPV6_ADDR_LINKLOCAL)
233  fl6.flowi6_oif = transport->saddr.v6.sin6_scope_id;
234  else
235  fl6.flowi6_oif = sk->sk_bound_dev_if;
236 
237  if (np->opt && np->opt->srcrt) {
238  struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
239  fl6.daddr = *rt0->addr;
240  }
241 
242  SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
243  __func__, skb, skb->len,
244  &fl6.saddr, &fl6.daddr);
245 
246  SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
247 
248  if (!(transport->param_flags & SPP_PMTUD_ENABLE))
249  skb->local_df = 1;
250 
251  return ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
252 }
253 
254 /* Returns the dst cache entry for the given source and destination ip
255  * addresses.
256  */
257 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
258  struct flowi *fl, struct sock *sk)
259 {
260  struct sctp_association *asoc = t->asoc;
261  struct dst_entry *dst = NULL;
262  struct flowi6 *fl6 = &fl->u.ip6;
263  struct sctp_bind_addr *bp;
264  struct sctp_sockaddr_entry *laddr;
265  union sctp_addr *baddr = NULL;
266  union sctp_addr *daddr = &t->ipaddr;
267  union sctp_addr dst_saddr;
268  __u8 matchlen = 0;
269  __u8 bmatchlen;
271 
272  memset(fl6, 0, sizeof(struct flowi6));
273  fl6->daddr = daddr->v6.sin6_addr;
274  fl6->fl6_dport = daddr->v6.sin6_port;
275  fl6->flowi6_proto = IPPROTO_SCTP;
276  if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
277  fl6->flowi6_oif = daddr->v6.sin6_scope_id;
278 
279  SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
280 
281  if (asoc)
282  fl6->fl6_sport = htons(asoc->base.bind_addr.port);
283 
284  if (saddr) {
285  fl6->saddr = saddr->v6.sin6_addr;
286  fl6->fl6_sport = saddr->v6.sin6_port;
287  SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
288  }
289 
290  dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
291  if (!asoc || saddr)
292  goto out;
293 
294  bp = &asoc->base.bind_addr;
295  scope = sctp_scope(daddr);
296  /* ip6_dst_lookup has filled in the fl6->saddr for us. Check
297  * to see if we can use it.
298  */
299  if (!IS_ERR(dst)) {
300  /* Walk through the bind address list and look for a bind
301  * address that matches the source address of the returned dst.
302  */
303  sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
304  rcu_read_lock();
305  list_for_each_entry_rcu(laddr, &bp->address_list, list) {
306  if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
307  continue;
308 
309  /* Do not compare against v4 addrs */
310  if ((laddr->a.sa.sa_family == AF_INET6) &&
311  (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
312  rcu_read_unlock();
313  goto out;
314  }
315  }
316  rcu_read_unlock();
317  /* None of the bound addresses match the source address of the
318  * dst. So release it.
319  */
320  dst_release(dst);
321  dst = NULL;
322  }
323 
324  /* Walk through the bind address list and try to get the
325  * best source address for a given destination.
326  */
327  rcu_read_lock();
328  list_for_each_entry_rcu(laddr, &bp->address_list, list) {
329  if (!laddr->valid && laddr->state != SCTP_ADDR_SRC)
330  continue;
331  if ((laddr->a.sa.sa_family == AF_INET6) &&
332  (scope <= sctp_scope(&laddr->a))) {
333  bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
334  if (!baddr || (matchlen < bmatchlen)) {
335  baddr = &laddr->a;
336  matchlen = bmatchlen;
337  }
338  }
339  }
340  rcu_read_unlock();
341  if (baddr) {
342  fl6->saddr = baddr->v6.sin6_addr;
343  fl6->fl6_sport = baddr->v6.sin6_port;
344  dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
345  }
346 
347 out:
348  if (!IS_ERR(dst)) {
349  struct rt6_info *rt;
350  rt = (struct rt6_info *)dst;
351  t->dst = dst;
352  SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
353  &rt->rt6i_dst.addr, &fl6->saddr);
354  } else {
355  t->dst = NULL;
356  SCTP_DEBUG_PRINTK("NO ROUTE\n");
357  }
358 }
359 
360 /* Returns the number of consecutive initial bits that match in the 2 ipv6
361  * addresses.
362  */
363 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
364  union sctp_addr *s2)
365 {
366  return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
367 }
368 
369 /* Fills in the source address(saddr) based on the destination address(daddr)
370  * and asoc's bind address list.
371  */
372 static void sctp_v6_get_saddr(struct sctp_sock *sk,
373  struct sctp_transport *t,
374  struct flowi *fl)
375 {
376  struct flowi6 *fl6 = &fl->u.ip6;
377  union sctp_addr *saddr = &t->saddr;
378 
379  SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
380 
381  if (t->dst) {
382  saddr->v6.sin6_family = AF_INET6;
383  saddr->v6.sin6_addr = fl6->saddr;
384  }
385 }
386 
387 /* Make a copy of all potential local addresses. */
388 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
389  struct net_device *dev)
390 {
391  struct inet6_dev *in6_dev;
392  struct inet6_ifaddr *ifp;
393  struct sctp_sockaddr_entry *addr;
394 
395  rcu_read_lock();
396  if ((in6_dev = __in6_dev_get(dev)) == NULL) {
397  rcu_read_unlock();
398  return;
399  }
400 
401  read_lock_bh(&in6_dev->lock);
402  list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
403  /* Add the address to the local list. */
404  addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
405  if (addr) {
406  addr->a.v6.sin6_family = AF_INET6;
407  addr->a.v6.sin6_port = 0;
408  addr->a.v6.sin6_addr = ifp->addr;
409  addr->a.v6.sin6_scope_id = dev->ifindex;
410  addr->valid = 1;
411  INIT_LIST_HEAD(&addr->list);
412  list_add_tail(&addr->list, addrlist);
413  }
414  }
415 
416  read_unlock_bh(&in6_dev->lock);
417  rcu_read_unlock();
418 }
419 
420 /* Initialize a sockaddr_storage from in incoming skb. */
421 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
422  int is_saddr)
423 {
424  __be16 *port;
425  struct sctphdr *sh;
426 
427  port = &addr->v6.sin6_port;
428  addr->v6.sin6_family = AF_INET6;
429  addr->v6.sin6_flowinfo = 0; /* FIXME */
430  addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
431 
432  sh = sctp_hdr(skb);
433  if (is_saddr) {
434  *port = sh->source;
435  addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
436  } else {
437  *port = sh->dest;
438  addr->v6.sin6_addr = ipv6_hdr(skb)->daddr;
439  }
440 }
441 
442 /* Initialize an sctp_addr from a socket. */
443 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
444 {
445  addr->v6.sin6_family = AF_INET6;
446  addr->v6.sin6_port = 0;
447  addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
448 }
449 
450 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
451 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
452 {
453  if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
454  inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
455  inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
456  inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
457  inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
458  addr->v4.sin_addr.s_addr;
459  } else {
460  inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
461  }
462 }
463 
464 /* Initialize sk->sk_daddr from sctp_addr. */
465 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
466 {
467  if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
468  inet6_sk(sk)->daddr.s6_addr32[0] = 0;
469  inet6_sk(sk)->daddr.s6_addr32[1] = 0;
470  inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
471  inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
472  } else {
473  inet6_sk(sk)->daddr = addr->v6.sin6_addr;
474  }
475 }
476 
477 /* Initialize a sctp_addr from an address parameter. */
478 static void sctp_v6_from_addr_param(union sctp_addr *addr,
479  union sctp_addr_param *param,
480  __be16 port, int iif)
481 {
482  addr->v6.sin6_family = AF_INET6;
483  addr->v6.sin6_port = port;
484  addr->v6.sin6_flowinfo = 0; /* BUG */
485  addr->v6.sin6_addr = param->v6.addr;
486  addr->v6.sin6_scope_id = iif;
487 }
488 
489 /* Initialize an address parameter from a sctp_addr and return the length
490  * of the address parameter.
491  */
492 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
493  union sctp_addr_param *param)
494 {
495  int length = sizeof(sctp_ipv6addr_param_t);
496 
497  param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
498  param->v6.param_hdr.length = htons(length);
499  param->v6.addr = addr->v6.sin6_addr;
500 
501  return length;
502 }
503 
504 /* Initialize a sctp_addr from struct in6_addr. */
505 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
506  __be16 port)
507 {
508  addr->sa.sa_family = AF_INET6;
509  addr->v6.sin6_port = port;
510  addr->v6.sin6_addr = *saddr;
511 }
512 
513 /* Compare addresses exactly.
514  * v4-mapped-v6 is also in consideration.
515  */
516 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
517  const union sctp_addr *addr2)
518 {
519  if (addr1->sa.sa_family != addr2->sa.sa_family) {
520  if (addr1->sa.sa_family == AF_INET &&
521  addr2->sa.sa_family == AF_INET6 &&
522  ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
523  if (addr2->v6.sin6_port == addr1->v4.sin_port &&
524  addr2->v6.sin6_addr.s6_addr32[3] ==
525  addr1->v4.sin_addr.s_addr)
526  return 1;
527  }
528  if (addr2->sa.sa_family == AF_INET &&
529  addr1->sa.sa_family == AF_INET6 &&
530  ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
531  if (addr1->v6.sin6_port == addr2->v4.sin_port &&
532  addr1->v6.sin6_addr.s6_addr32[3] ==
533  addr2->v4.sin_addr.s_addr)
534  return 1;
535  }
536  return 0;
537  }
538  if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
539  return 0;
540  /* If this is a linklocal address, compare the scope_id. */
541  if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
542  if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
543  (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
544  return 0;
545  }
546  }
547 
548  return 1;
549 }
550 
551 /* Initialize addr struct to INADDR_ANY. */
552 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
553 {
554  memset(addr, 0x00, sizeof(union sctp_addr));
555  addr->v6.sin6_family = AF_INET6;
556  addr->v6.sin6_port = port;
557 }
558 
559 /* Is this a wildcard address? */
560 static int sctp_v6_is_any(const union sctp_addr *addr)
561 {
562  return ipv6_addr_any(&addr->v6.sin6_addr);
563 }
564 
565 /* Should this be available for binding? */
566 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
567 {
568  int type;
569  const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
570 
571  type = ipv6_addr_type(in6);
572  if (IPV6_ADDR_ANY == type)
573  return 1;
574  if (type == IPV6_ADDR_MAPPED) {
575  if (sp && !sp->v4mapped)
576  return 0;
577  if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
578  return 0;
579  sctp_v6_map_v4(addr);
580  return sctp_get_af_specific(AF_INET)->available(addr, sp);
581  }
582  if (!(type & IPV6_ADDR_UNICAST))
583  return 0;
584 
585  return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0);
586 }
587 
588 /* This function checks if the address is a valid address to be used for
589  * SCTP.
590  *
591  * Output:
592  * Return 0 - If the address is a non-unicast or an illegal address.
593  * Return 1 - If the address is a unicast.
594  */
595 static int sctp_v6_addr_valid(union sctp_addr *addr,
596  struct sctp_sock *sp,
597  const struct sk_buff *skb)
598 {
599  int ret = ipv6_addr_type(&addr->v6.sin6_addr);
600 
601  /* Support v4-mapped-v6 address. */
602  if (ret == IPV6_ADDR_MAPPED) {
603  /* Note: This routine is used in input, so v4-mapped-v6
604  * are disallowed here when there is no sctp_sock.
605  */
606  if (!sp || !sp->v4mapped)
607  return 0;
608  if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
609  return 0;
610  sctp_v6_map_v4(addr);
611  return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
612  }
613 
614  /* Is this a non-unicast address */
615  if (!(ret & IPV6_ADDR_UNICAST))
616  return 0;
617 
618  return 1;
619 }
620 
621 /* What is the scope of 'addr'? */
622 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
623 {
624  int v6scope;
626 
627  /* The IPv6 scope is really a set of bit fields.
628  * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope.
629  */
630 
631  v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
632  switch (v6scope) {
633  case IFA_HOST:
634  retval = SCTP_SCOPE_LOOPBACK;
635  break;
636  case IFA_LINK:
637  retval = SCTP_SCOPE_LINK;
638  break;
639  case IFA_SITE:
640  retval = SCTP_SCOPE_PRIVATE;
641  break;
642  default:
643  retval = SCTP_SCOPE_GLOBAL;
644  break;
645  }
646 
647  return retval;
648 }
649 
650 /* Create and initialize a new sk for the socket to be returned by accept(). */
651 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
652  struct sctp_association *asoc)
653 {
654  struct sock *newsk;
655  struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
656  struct sctp6_sock *newsctp6sk;
657 
658  newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
659  if (!newsk)
660  goto out;
661 
662  sock_init_data(NULL, newsk);
663 
664  sctp_copy_sock(newsk, sk, asoc);
665  sock_reset_flag(sk, SOCK_ZAPPED);
666 
667  newsctp6sk = (struct sctp6_sock *)newsk;
668  inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
669 
670  sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
671 
672  newnp = inet6_sk(newsk);
673 
674  memcpy(newnp, np, sizeof(struct ipv6_pinfo));
675 
676  /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
677  * and getpeername().
678  */
679  sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
680 
681  sk_refcnt_debug_inc(newsk);
682 
683  if (newsk->sk_prot->init(newsk)) {
684  sk_common_release(newsk);
685  newsk = NULL;
686  }
687 
688 out:
689  return newsk;
690 }
691 
692 /* Map v4 address to mapped v6 address */
693 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
694 {
695  if (sp->v4mapped && AF_INET == addr->sa.sa_family)
696  sctp_v4_map_v6(addr);
697 }
698 
699 /* Where did this skb come from? */
700 static int sctp_v6_skb_iif(const struct sk_buff *skb)
701 {
702  struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
703  return opt->iif;
704 }
705 
706 /* Was this packet marked by Explicit Congestion Notification? */
707 static int sctp_v6_is_ce(const struct sk_buff *skb)
708 {
709  return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
710 }
711 
712 /* Dump the v6 addr to the seq file. */
713 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
714 {
715  seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
716 }
717 
718 static void sctp_v6_ecn_capable(struct sock *sk)
719 {
720  inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
721 }
722 
723 /* Initialize a PF_INET6 socket msg_name. */
724 static void sctp_inet6_msgname(char *msgname, int *addr_len)
725 {
726  struct sockaddr_in6 *sin6;
727 
728  sin6 = (struct sockaddr_in6 *)msgname;
729  sin6->sin6_family = AF_INET6;
730  sin6->sin6_flowinfo = 0;
731  sin6->sin6_scope_id = 0; /*FIXME */
732  *addr_len = sizeof(struct sockaddr_in6);
733 }
734 
735 /* Initialize a PF_INET msgname from a ulpevent. */
736 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
737  char *msgname, int *addrlen)
738 {
739  struct sockaddr_in6 *sin6, *sin6from;
740 
741  if (msgname) {
742  union sctp_addr *addr;
743  struct sctp_association *asoc;
744 
745  asoc = event->asoc;
746  sctp_inet6_msgname(msgname, addrlen);
747  sin6 = (struct sockaddr_in6 *)msgname;
748  sin6->sin6_port = htons(asoc->peer.port);
749  addr = &asoc->peer.primary_addr;
750 
751  /* Note: If we go to a common v6 format, this code
752  * will change.
753  */
754 
755  /* Map ipv4 address into v4-mapped-on-v6 address. */
756  if (sctp_sk(asoc->base.sk)->v4mapped &&
757  AF_INET == addr->sa.sa_family) {
758  sctp_v4_map_v6((union sctp_addr *)sin6);
759  sin6->sin6_addr.s6_addr32[3] =
760  addr->v4.sin_addr.s_addr;
761  return;
762  }
763 
764  sin6from = &asoc->peer.primary_addr.v6;
765  sin6->sin6_addr = sin6from->sin6_addr;
766  if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
767  sin6->sin6_scope_id = sin6from->sin6_scope_id;
768  }
769 }
770 
771 /* Initialize a msg_name from an inbound skb. */
772 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
773  int *addr_len)
774 {
775  struct sctphdr *sh;
776  struct sockaddr_in6 *sin6;
777 
778  if (msgname) {
779  sctp_inet6_msgname(msgname, addr_len);
780  sin6 = (struct sockaddr_in6 *)msgname;
781  sh = sctp_hdr(skb);
782  sin6->sin6_port = sh->source;
783 
784  /* Map ipv4 address into v4-mapped-on-v6 address. */
785  if (sctp_sk(skb->sk)->v4mapped &&
786  ip_hdr(skb)->version == 4) {
787  sctp_v4_map_v6((union sctp_addr *)sin6);
788  sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
789  return;
790  }
791 
792  /* Otherwise, just copy the v6 address. */
793  sin6->sin6_addr = ipv6_hdr(skb)->saddr;
794  if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
795  struct sctp_ulpevent *ev = sctp_skb2event(skb);
796  sin6->sin6_scope_id = ev->iif;
797  }
798  }
799 }
800 
801 /* Do we support this AF? */
802 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
803 {
804  switch (family) {
805  case AF_INET6:
806  return 1;
807  /* v4-mapped-v6 addresses */
808  case AF_INET:
809  if (!__ipv6_only_sock(sctp_opt2sk(sp)))
810  return 1;
811  default:
812  return 0;
813  }
814 }
815 
816 /* Address matching with wildcards allowed. This extra level
817  * of indirection lets us choose whether a PF_INET6 should
818  * disallow any v4 addresses if we so choose.
819  */
820 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
821  const union sctp_addr *addr2,
822  struct sctp_sock *opt)
823 {
824  struct sctp_af *af1, *af2;
825  struct sock *sk = sctp_opt2sk(opt);
826 
827  af1 = sctp_get_af_specific(addr1->sa.sa_family);
828  af2 = sctp_get_af_specific(addr2->sa.sa_family);
829 
830  if (!af1 || !af2)
831  return 0;
832 
833  /* If the socket is IPv6 only, v4 addrs will not match */
834  if (__ipv6_only_sock(sk) && af1 != af2)
835  return 0;
836 
837  /* Today, wildcard AF_INET/AF_INET6. */
838  if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
839  return 1;
840 
841  if (addr1->sa.sa_family != addr2->sa.sa_family)
842  return 0;
843 
844  return af1->cmp_addr(addr1, addr2);
845 }
846 
847 /* Verify that the provided sockaddr looks bindable. Common verification,
848  * has already been taken care of.
849  */
850 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
851 {
852  struct sctp_af *af;
853 
854  /* ASSERT: address family has already been verified. */
855  if (addr->sa.sa_family != AF_INET6)
856  af = sctp_get_af_specific(addr->sa.sa_family);
857  else {
858  int type = ipv6_addr_type(&addr->v6.sin6_addr);
859  struct net_device *dev;
860 
861  if (type & IPV6_ADDR_LINKLOCAL) {
862  struct net *net;
863  if (!addr->v6.sin6_scope_id)
864  return 0;
865  net = sock_net(&opt->inet.sk);
866  rcu_read_lock();
867  dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
868  if (!dev ||
869  !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
870  rcu_read_unlock();
871  return 0;
872  }
873  rcu_read_unlock();
874  } else if (type == IPV6_ADDR_MAPPED) {
875  if (!opt->v4mapped)
876  return 0;
877  }
878 
879  af = opt->pf->af;
880  }
881  return af->available(addr, opt);
882 }
883 
884 /* Verify that the provided sockaddr looks sendable. Common verification,
885  * has already been taken care of.
886  */
887 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
888 {
889  struct sctp_af *af = NULL;
890 
891  /* ASSERT: address family has already been verified. */
892  if (addr->sa.sa_family != AF_INET6)
893  af = sctp_get_af_specific(addr->sa.sa_family);
894  else {
895  int type = ipv6_addr_type(&addr->v6.sin6_addr);
896  struct net_device *dev;
897 
898  if (type & IPV6_ADDR_LINKLOCAL) {
899  if (!addr->v6.sin6_scope_id)
900  return 0;
901  rcu_read_lock();
902  dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
903  addr->v6.sin6_scope_id);
904  rcu_read_unlock();
905  if (!dev)
906  return 0;
907  }
908  af = opt->pf->af;
909  }
910 
911  return af != NULL;
912 }
913 
914 /* Fill in Supported Address Type information for INIT and INIT-ACK
915  * chunks. Note: In the future, we may want to look at sock options
916  * to determine whether a PF_INET6 socket really wants to have IPV4
917  * addresses.
918  * Returns number of addresses supported.
919  */
920 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
921  __be16 *types)
922 {
923  types[0] = SCTP_PARAM_IPV6_ADDRESS;
924  if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
925  types[1] = SCTP_PARAM_IPV4_ADDRESS;
926  return 2;
927  }
928  return 1;
929 }
930 
931 static const struct proto_ops inet6_seqpacket_ops = {
932  .family = PF_INET6,
933  .owner = THIS_MODULE,
934  .release = inet6_release,
935  .bind = inet6_bind,
936  .connect = inet_dgram_connect,
937  .socketpair = sock_no_socketpair,
938  .accept = inet_accept,
939  .getname = inet6_getname,
940  .poll = sctp_poll,
941  .ioctl = inet6_ioctl,
942  .listen = sctp_inet_listen,
943  .shutdown = inet_shutdown,
944  .setsockopt = sock_common_setsockopt,
945  .getsockopt = sock_common_getsockopt,
946  .sendmsg = inet_sendmsg,
947  .recvmsg = sock_common_recvmsg,
948  .mmap = sock_no_mmap,
949 #ifdef CONFIG_COMPAT
950  .compat_setsockopt = compat_sock_common_setsockopt,
951  .compat_getsockopt = compat_sock_common_getsockopt,
952 #endif
953 };
954 
955 static struct inet_protosw sctpv6_seqpacket_protosw = {
956  .type = SOCK_SEQPACKET,
957  .protocol = IPPROTO_SCTP,
958  .prot = &sctpv6_prot,
959  .ops = &inet6_seqpacket_ops,
960  .no_check = 0,
961  .flags = SCTP_PROTOSW_FLAG
962 };
963 static struct inet_protosw sctpv6_stream_protosw = {
964  .type = SOCK_STREAM,
965  .protocol = IPPROTO_SCTP,
966  .prot = &sctpv6_prot,
967  .ops = &inet6_seqpacket_ops,
968  .no_check = 0,
969  .flags = SCTP_PROTOSW_FLAG,
970 };
971 
972 static int sctp6_rcv(struct sk_buff *skb)
973 {
974  return sctp_rcv(skb) ? -1 : 0;
975 }
976 
977 static const struct inet6_protocol sctpv6_protocol = {
978  .handler = sctp6_rcv,
979  .err_handler = sctp_v6_err,
980  .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
981 };
982 
983 static struct sctp_af sctp_af_inet6 = {
984  .sa_family = AF_INET6,
985  .sctp_xmit = sctp_v6_xmit,
986  .setsockopt = ipv6_setsockopt,
987  .getsockopt = ipv6_getsockopt,
988  .get_dst = sctp_v6_get_dst,
989  .get_saddr = sctp_v6_get_saddr,
990  .copy_addrlist = sctp_v6_copy_addrlist,
991  .from_skb = sctp_v6_from_skb,
992  .from_sk = sctp_v6_from_sk,
993  .to_sk_saddr = sctp_v6_to_sk_saddr,
994  .to_sk_daddr = sctp_v6_to_sk_daddr,
995  .from_addr_param = sctp_v6_from_addr_param,
996  .to_addr_param = sctp_v6_to_addr_param,
997  .cmp_addr = sctp_v6_cmp_addr,
998  .scope = sctp_v6_scope,
999  .addr_valid = sctp_v6_addr_valid,
1000  .inaddr_any = sctp_v6_inaddr_any,
1001  .is_any = sctp_v6_is_any,
1002  .available = sctp_v6_available,
1003  .skb_iif = sctp_v6_skb_iif,
1004  .is_ce = sctp_v6_is_ce,
1005  .seq_dump_addr = sctp_v6_seq_dump_addr,
1006  .ecn_capable = sctp_v6_ecn_capable,
1007  .net_header_len = sizeof(struct ipv6hdr),
1008  .sockaddr_len = sizeof(struct sockaddr_in6),
1009 #ifdef CONFIG_COMPAT
1010  .compat_setsockopt = compat_ipv6_setsockopt,
1011  .compat_getsockopt = compat_ipv6_getsockopt,
1012 #endif
1013 };
1014 
1015 static struct sctp_pf sctp_pf_inet6 = {
1016  .event_msgname = sctp_inet6_event_msgname,
1017  .skb_msgname = sctp_inet6_skb_msgname,
1018  .af_supported = sctp_inet6_af_supported,
1019  .cmp_addr = sctp_inet6_cmp_addr,
1020  .bind_verify = sctp_inet6_bind_verify,
1021  .send_verify = sctp_inet6_send_verify,
1022  .supported_addrs = sctp_inet6_supported_addrs,
1023  .create_accept_sk = sctp_v6_create_accept_sk,
1024  .addr_v4map = sctp_v6_addr_v4map,
1025  .af = &sctp_af_inet6,
1026 };
1027 
1028 /* Initialize IPv6 support and register with socket layer. */
1030 {
1031  /* Register the SCTP specific PF_INET6 functions. */
1032  sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1033 
1034  /* Register the SCTP specific AF_INET6 functions. */
1035  sctp_register_af(&sctp_af_inet6);
1036 }
1037 
1039 {
1040  list_del(&sctp_af_inet6.list);
1041 }
1042 
1043 /* Initialize IPv6 support and register with socket layer. */
1045 {
1046  int rc;
1047 
1048  rc = proto_register(&sctpv6_prot, 1);
1049  if (rc)
1050  return rc;
1051 
1052  /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1053  inet6_register_protosw(&sctpv6_seqpacket_protosw);
1054  inet6_register_protosw(&sctpv6_stream_protosw);
1055 
1056  return 0;
1057 }
1058 
1060 {
1061  inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1062  inet6_unregister_protosw(&sctpv6_stream_protosw);
1064 }
1065 
1066 
1067 /* Register with inet6 layer. */
1069 {
1070  /* Register notifier for inet6 address additions/deletions. */
1071  register_inet6addr_notifier(&sctp_inet6addr_notifier);
1072 
1073  if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1074  return -EAGAIN;
1075 
1076  return 0;
1077 }
1078 
1079 /* Unregister with inet6 layer. */
1081 {
1082  inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1083  unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1084 }