xref: /linux/net/sctp/ipv6.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
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 const 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 }
1061