xref: /linux/net/sctp/ipv6.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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 			memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
101 				 sizeof(struct in6_addr));
102 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
103 			addr->valid = 1;
104 			spin_lock_bh(&sctp_local_addr_lock);
105 			list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
106 			spin_unlock_bh(&sctp_local_addr_lock);
107 		}
108 		break;
109 	case NETDEV_DOWN:
110 		spin_lock_bh(&sctp_local_addr_lock);
111 		list_for_each_entry_safe(addr, temp,
112 					&sctp_local_addr_list, list) {
113 			if (addr->a.sa.sa_family == AF_INET6 &&
114 					ipv6_addr_equal(&addr->a.v6.sin6_addr,
115 						&ifa->addr)) {
116 				found = 1;
117 				addr->valid = 0;
118 				list_del_rcu(&addr->list);
119 				break;
120 			}
121 		}
122 		spin_unlock_bh(&sctp_local_addr_lock);
123 		if (found)
124 			call_rcu(&addr->rcu, sctp_local_addr_free);
125 		break;
126 	}
127 
128 	return NOTIFY_DONE;
129 }
130 
131 static struct notifier_block sctp_inet6addr_notifier = {
132 	.notifier_call = sctp_inet6addr_event,
133 };
134 
135 /* ICMP error handler. */
136 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
137 			     int type, int code, int offset, __be32 info)
138 {
139 	struct inet6_dev *idev;
140 	struct sock *sk;
141 	struct sctp_association *asoc;
142 	struct sctp_transport *transport;
143 	struct ipv6_pinfo *np;
144 	sk_buff_data_t saveip, savesctp;
145 	int err;
146 
147 	idev = in6_dev_get(skb->dev);
148 
149 	/* Fix up skb to look at the embedded net header. */
150 	saveip	 = skb->network_header;
151 	savesctp = skb->transport_header;
152 	skb_reset_network_header(skb);
153 	skb_set_transport_header(skb, offset);
154 	sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
155 	/* Put back, the original pointers. */
156 	skb->network_header   = saveip;
157 	skb->transport_header = savesctp;
158 	if (!sk) {
159 		ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
160 		goto out;
161 	}
162 
163 	/* Warning:  The sock lock is held.  Remember to call
164 	 * sctp_err_finish!
165 	 */
166 
167 	switch (type) {
168 	case ICMPV6_PKT_TOOBIG:
169 		sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
170 		goto out_unlock;
171 	case ICMPV6_PARAMPROB:
172 		if (ICMPV6_UNK_NEXTHDR == code) {
173 			sctp_icmp_proto_unreachable(sk, asoc, transport);
174 			goto out_unlock;
175 		}
176 		break;
177 	default:
178 		break;
179 	}
180 
181 	np = inet6_sk(sk);
182 	icmpv6_err_convert(type, code, &err);
183 	if (!sock_owned_by_user(sk) && np->recverr) {
184 		sk->sk_err = err;
185 		sk->sk_error_report(sk);
186 	} else {  /* Only an error on timeout */
187 		sk->sk_err_soft = err;
188 	}
189 
190 out_unlock:
191 	sctp_err_finish(sk, asoc);
192 out:
193 	if (likely(idev != NULL))
194 		in6_dev_put(idev);
195 }
196 
197 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
198 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
199 {
200 	struct sock *sk = skb->sk;
201 	struct ipv6_pinfo *np = inet6_sk(sk);
202 	struct flowi fl;
203 
204 	memset(&fl, 0, sizeof(fl));
205 
206 	fl.proto = sk->sk_protocol;
207 
208 	/* Fill in the dest address from the route entry passed with the skb
209 	 * and the source address from the transport.
210 	 */
211 	ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
212 	ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
213 
214 	fl.fl6_flowlabel = np->flow_label;
215 	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
216 	if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
217 		fl.oif = transport->saddr.v6.sin6_scope_id;
218 	else
219 		fl.oif = sk->sk_bound_dev_if;
220 
221 	if (np->opt && np->opt->srcrt) {
222 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
223 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
224 	}
225 
226 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
227 			  __func__, skb, skb->len,
228 			  &fl.fl6_src, &fl.fl6_dst);
229 
230 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
231 
232 	if (!(transport->param_flags & SPP_PMTUD_ENABLE))
233 		skb->local_df = 1;
234 
235 	return ip6_xmit(sk, skb, &fl, np->opt, 0);
236 }
237 
238 /* Returns the dst cache entry for the given source and destination ip
239  * addresses.
240  */
241 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
242 					 union sctp_addr *daddr,
243 					 union sctp_addr *saddr)
244 {
245 	struct dst_entry *dst;
246 	struct flowi fl;
247 
248 	memset(&fl, 0, sizeof(fl));
249 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
250 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
251 		fl.oif = daddr->v6.sin6_scope_id;
252 
253 
254 	SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl.fl6_dst);
255 
256 	if (saddr) {
257 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
258 		SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl.fl6_src);
259 	}
260 
261 	dst = ip6_route_output(&init_net, NULL, &fl);
262 	if (!dst->error) {
263 		struct rt6_info *rt;
264 		rt = (struct rt6_info *)dst;
265 		SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
266 			&rt->rt6i_dst.addr, &rt->rt6i_src.addr);
267 		return dst;
268 	}
269 	SCTP_DEBUG_PRINTK("NO ROUTE\n");
270 	dst_release(dst);
271 	return NULL;
272 }
273 
274 /* Returns the number of consecutive initial bits that match in the 2 ipv6
275  * addresses.
276  */
277 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
278 					 union sctp_addr *s2)
279 {
280 	struct in6_addr *a1 = &s1->v6.sin6_addr;
281 	struct in6_addr *a2 = &s2->v6.sin6_addr;
282 	int i, j;
283 
284 	for (i = 0; i < 4 ; i++) {
285 		__be32 a1xora2;
286 
287 		a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
288 
289 		if ((j = fls(ntohl(a1xora2))))
290 			return (i * 32 + 32 - j);
291 	}
292 
293 	return (i*32);
294 }
295 
296 /* Fills in the source address(saddr) based on the destination address(daddr)
297  * and asoc's bind address list.
298  */
299 static void sctp_v6_get_saddr(struct sctp_sock *sk,
300 			      struct sctp_association *asoc,
301 			      struct dst_entry *dst,
302 			      union sctp_addr *daddr,
303 			      union sctp_addr *saddr)
304 {
305 	struct sctp_bind_addr *bp;
306 	struct sctp_sockaddr_entry *laddr;
307 	sctp_scope_t scope;
308 	union sctp_addr *baddr = NULL;
309 	__u8 matchlen = 0;
310 	__u8 bmatchlen;
311 
312 	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
313 			  __func__, asoc, dst, &daddr->v6.sin6_addr);
314 
315 	if (!asoc) {
316 		ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
317 				   dst ? ip6_dst_idev(dst)->dev : NULL,
318 				   &daddr->v6.sin6_addr,
319 				   inet6_sk(&sk->inet.sk)->srcprefs,
320 				   &saddr->v6.sin6_addr);
321 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
322 				  &saddr->v6.sin6_addr);
323 		return;
324 	}
325 
326 	scope = sctp_scope(daddr);
327 
328 	bp = &asoc->base.bind_addr;
329 
330 	/* Go through the bind address list and find the best source address
331 	 * that matches the scope of the destination address.
332 	 */
333 	rcu_read_lock();
334 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
335 		if (!laddr->valid)
336 			continue;
337 		if ((laddr->state == SCTP_ADDR_SRC) &&
338 		    (laddr->a.sa.sa_family == AF_INET6) &&
339 		    (scope <= sctp_scope(&laddr->a))) {
340 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
341 			if (!baddr || (matchlen < bmatchlen)) {
342 				baddr = &laddr->a;
343 				matchlen = bmatchlen;
344 			}
345 		}
346 	}
347 
348 	if (baddr) {
349 		memcpy(saddr, baddr, sizeof(union sctp_addr));
350 		SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
351 	} else {
352 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
353 		       "address for the dest:%pI6\n",
354 		       __func__, asoc, &daddr->v6.sin6_addr);
355 	}
356 
357 	rcu_read_unlock();
358 }
359 
360 /* Make a copy of all potential local addresses. */
361 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
362 				  struct net_device *dev)
363 {
364 	struct inet6_dev *in6_dev;
365 	struct inet6_ifaddr *ifp;
366 	struct sctp_sockaddr_entry *addr;
367 
368 	rcu_read_lock();
369 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
370 		rcu_read_unlock();
371 		return;
372 	}
373 
374 	read_lock_bh(&in6_dev->lock);
375 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
376 		/* Add the address to the local list.  */
377 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
378 		if (addr) {
379 			addr->a.v6.sin6_family = AF_INET6;
380 			addr->a.v6.sin6_port = 0;
381 			addr->a.v6.sin6_addr = ifp->addr;
382 			addr->a.v6.sin6_scope_id = dev->ifindex;
383 			addr->valid = 1;
384 			INIT_LIST_HEAD(&addr->list);
385 			INIT_RCU_HEAD(&addr->rcu);
386 			list_add_tail(&addr->list, addrlist);
387 		}
388 	}
389 
390 	read_unlock_bh(&in6_dev->lock);
391 	rcu_read_unlock();
392 }
393 
394 /* Initialize a sockaddr_storage from in incoming skb. */
395 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
396 			     int is_saddr)
397 {
398 	void *from;
399 	__be16 *port;
400 	struct sctphdr *sh;
401 
402 	port = &addr->v6.sin6_port;
403 	addr->v6.sin6_family = AF_INET6;
404 	addr->v6.sin6_flowinfo = 0; /* FIXME */
405 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
406 
407 	sh = sctp_hdr(skb);
408 	if (is_saddr) {
409 		*port  = sh->source;
410 		from = &ipv6_hdr(skb)->saddr;
411 	} else {
412 		*port = sh->dest;
413 		from = &ipv6_hdr(skb)->daddr;
414 	}
415 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
416 }
417 
418 /* Initialize an sctp_addr from a socket. */
419 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
420 {
421 	addr->v6.sin6_family = AF_INET6;
422 	addr->v6.sin6_port = 0;
423 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
424 }
425 
426 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
427 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
428 {
429 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
430 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
431 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
432 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
433 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
434 			addr->v4.sin_addr.s_addr;
435 	} else {
436 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
437 	}
438 }
439 
440 /* Initialize sk->sk_daddr from sctp_addr. */
441 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
442 {
443 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
444 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
445 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
446 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
447 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
448 	} else {
449 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
450 	}
451 }
452 
453 /* Initialize a sctp_addr from an address parameter. */
454 static void sctp_v6_from_addr_param(union sctp_addr *addr,
455 				    union sctp_addr_param *param,
456 				    __be16 port, int iif)
457 {
458 	addr->v6.sin6_family = AF_INET6;
459 	addr->v6.sin6_port = port;
460 	addr->v6.sin6_flowinfo = 0; /* BUG */
461 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
462 	addr->v6.sin6_scope_id = iif;
463 }
464 
465 /* Initialize an address parameter from a sctp_addr and return the length
466  * of the address parameter.
467  */
468 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
469 				 union sctp_addr_param *param)
470 {
471 	int length = sizeof(sctp_ipv6addr_param_t);
472 
473 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
474 	param->v6.param_hdr.length = htons(length);
475 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
476 
477 	return length;
478 }
479 
480 /* Initialize a sctp_addr from a dst_entry. */
481 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
482 			      __be16 port)
483 {
484 	struct rt6_info *rt = (struct rt6_info *)dst;
485 	addr->sa.sa_family = AF_INET6;
486 	addr->v6.sin6_port = port;
487 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
488 }
489 
490 /* Compare addresses exactly.
491  * v4-mapped-v6 is also in consideration.
492  */
493 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
494 			    const union sctp_addr *addr2)
495 {
496 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
497 		if (addr1->sa.sa_family == AF_INET &&
498 		    addr2->sa.sa_family == AF_INET6 &&
499 		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
500 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
501 			    addr2->v6.sin6_addr.s6_addr32[3] ==
502 			    addr1->v4.sin_addr.s_addr)
503 				return 1;
504 		}
505 		if (addr2->sa.sa_family == AF_INET &&
506 		    addr1->sa.sa_family == AF_INET6 &&
507 		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
508 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
509 			    addr1->v6.sin6_addr.s6_addr32[3] ==
510 			    addr2->v4.sin_addr.s_addr)
511 				return 1;
512 		}
513 		return 0;
514 	}
515 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
516 		return 0;
517 	/* If this is a linklocal address, compare the scope_id. */
518 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
519 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
520 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
521 			return 0;
522 		}
523 	}
524 
525 	return 1;
526 }
527 
528 /* Initialize addr struct to INADDR_ANY. */
529 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
530 {
531 	memset(addr, 0x00, sizeof(union sctp_addr));
532 	addr->v6.sin6_family = AF_INET6;
533 	addr->v6.sin6_port = port;
534 }
535 
536 /* Is this a wildcard address? */
537 static int sctp_v6_is_any(const union sctp_addr *addr)
538 {
539 	return ipv6_addr_any(&addr->v6.sin6_addr);
540 }
541 
542 /* Should this be available for binding?   */
543 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
544 {
545 	int type;
546 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
547 
548 	type = ipv6_addr_type(in6);
549 	if (IPV6_ADDR_ANY == type)
550 		return 1;
551 	if (type == IPV6_ADDR_MAPPED) {
552 		if (sp && !sp->v4mapped)
553 			return 0;
554 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
555 			return 0;
556 		sctp_v6_map_v4(addr);
557 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
558 	}
559 	if (!(type & IPV6_ADDR_UNICAST))
560 		return 0;
561 
562 	return ipv6_chk_addr(&init_net, in6, NULL, 0);
563 }
564 
565 /* This function checks if the address is a valid address to be used for
566  * SCTP.
567  *
568  * Output:
569  * Return 0 - If the address is a non-unicast or an illegal address.
570  * Return 1 - If the address is a unicast.
571  */
572 static int sctp_v6_addr_valid(union sctp_addr *addr,
573 			      struct sctp_sock *sp,
574 			      const struct sk_buff *skb)
575 {
576 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
577 
578 	/* Support v4-mapped-v6 address. */
579 	if (ret == IPV6_ADDR_MAPPED) {
580 		/* Note: This routine is used in input, so v4-mapped-v6
581 		 * are disallowed here when there is no sctp_sock.
582 		 */
583 		if (!sp || !sp->v4mapped)
584 			return 0;
585 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
586 			return 0;
587 		sctp_v6_map_v4(addr);
588 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
589 	}
590 
591 	/* Is this a non-unicast address */
592 	if (!(ret & IPV6_ADDR_UNICAST))
593 		return 0;
594 
595 	return 1;
596 }
597 
598 /* What is the scope of 'addr'?  */
599 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
600 {
601 	int v6scope;
602 	sctp_scope_t retval;
603 
604 	/* The IPv6 scope is really a set of bit fields.
605 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
606 	 */
607 
608 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
609 	switch (v6scope) {
610 	case IFA_HOST:
611 		retval = SCTP_SCOPE_LOOPBACK;
612 		break;
613 	case IFA_LINK:
614 		retval = SCTP_SCOPE_LINK;
615 		break;
616 	case IFA_SITE:
617 		retval = SCTP_SCOPE_PRIVATE;
618 		break;
619 	default:
620 		retval = SCTP_SCOPE_GLOBAL;
621 		break;
622 	}
623 
624 	return retval;
625 }
626 
627 /* Create and initialize a new sk for the socket to be returned by accept(). */
628 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
629 					     struct sctp_association *asoc)
630 {
631 	struct inet_sock *inet = inet_sk(sk);
632 	struct sock *newsk;
633 	struct inet_sock *newinet;
634 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
635 	struct sctp6_sock *newsctp6sk;
636 
637 	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
638 	if (!newsk)
639 		goto out;
640 
641 	sock_init_data(NULL, newsk);
642 
643 	newsk->sk_type = SOCK_STREAM;
644 
645 	newsk->sk_prot = sk->sk_prot;
646 	newsk->sk_no_check = sk->sk_no_check;
647 	newsk->sk_reuse = sk->sk_reuse;
648 
649 	newsk->sk_destruct = inet_sock_destruct;
650 	newsk->sk_family = PF_INET6;
651 	newsk->sk_protocol = IPPROTO_SCTP;
652 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
653 	newsk->sk_shutdown = sk->sk_shutdown;
654 	sock_reset_flag(sk, SOCK_ZAPPED);
655 
656 	newsctp6sk = (struct sctp6_sock *)newsk;
657 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
658 
659 	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
660 
661 	newinet = inet_sk(newsk);
662 	newnp = inet6_sk(newsk);
663 
664 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
665 
666 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
667 	 * and getpeername().
668 	 */
669 	newinet->sport = inet->sport;
670 	newnp->saddr = np->saddr;
671 	newnp->rcv_saddr = np->rcv_saddr;
672 	newinet->dport = htons(asoc->peer.port);
673 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
674 
675 	/* Init the ipv4 part of the socket since we can have sockets
676 	 * using v6 API for ipv4.
677 	 */
678 	newinet->uc_ttl = -1;
679 	newinet->mc_loop = 1;
680 	newinet->mc_ttl = 1;
681 	newinet->mc_index = 0;
682 	newinet->mc_list = NULL;
683 
684 	if (ipv4_config.no_pmtu_disc)
685 		newinet->pmtudisc = IP_PMTUDISC_DONT;
686 	else
687 		newinet->pmtudisc = IP_PMTUDISC_WANT;
688 
689 	sk_refcnt_debug_inc(newsk);
690 
691 	if (newsk->sk_prot->init(newsk)) {
692 		sk_common_release(newsk);
693 		newsk = NULL;
694 	}
695 
696 out:
697 	return newsk;
698 }
699 
700 /* Map v4 address to mapped v6 address */
701 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
702 {
703 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
704 		sctp_v4_map_v6(addr);
705 }
706 
707 /* Where did this skb come from?  */
708 static int sctp_v6_skb_iif(const struct sk_buff *skb)
709 {
710 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
711 	return opt->iif;
712 }
713 
714 /* Was this packet marked by Explicit Congestion Notification? */
715 static int sctp_v6_is_ce(const struct sk_buff *skb)
716 {
717 	return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
718 }
719 
720 /* Dump the v6 addr to the seq file. */
721 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
722 {
723 	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
724 }
725 
726 static void sctp_v6_ecn_capable(struct sock *sk)
727 {
728 	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
729 }
730 
731 /* Initialize a PF_INET6 socket msg_name. */
732 static void sctp_inet6_msgname(char *msgname, int *addr_len)
733 {
734 	struct sockaddr_in6 *sin6;
735 
736 	sin6 = (struct sockaddr_in6 *)msgname;
737 	sin6->sin6_family = AF_INET6;
738 	sin6->sin6_flowinfo = 0;
739 	sin6->sin6_scope_id = 0; /*FIXME */
740 	*addr_len = sizeof(struct sockaddr_in6);
741 }
742 
743 /* Initialize a PF_INET msgname from a ulpevent. */
744 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
745 				     char *msgname, int *addrlen)
746 {
747 	struct sockaddr_in6 *sin6, *sin6from;
748 
749 	if (msgname) {
750 		union sctp_addr *addr;
751 		struct sctp_association *asoc;
752 
753 		asoc = event->asoc;
754 		sctp_inet6_msgname(msgname, addrlen);
755 		sin6 = (struct sockaddr_in6 *)msgname;
756 		sin6->sin6_port = htons(asoc->peer.port);
757 		addr = &asoc->peer.primary_addr;
758 
759 		/* Note: If we go to a common v6 format, this code
760 		 * will change.
761 		 */
762 
763 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
764 		if (sctp_sk(asoc->base.sk)->v4mapped &&
765 		    AF_INET == addr->sa.sa_family) {
766 			sctp_v4_map_v6((union sctp_addr *)sin6);
767 			sin6->sin6_addr.s6_addr32[3] =
768 				addr->v4.sin_addr.s_addr;
769 			return;
770 		}
771 
772 		sin6from = &asoc->peer.primary_addr.v6;
773 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
774 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
775 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
776 	}
777 }
778 
779 /* Initialize a msg_name from an inbound skb. */
780 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
781 				   int *addr_len)
782 {
783 	struct sctphdr *sh;
784 	struct sockaddr_in6 *sin6;
785 
786 	if (msgname) {
787 		sctp_inet6_msgname(msgname, addr_len);
788 		sin6 = (struct sockaddr_in6 *)msgname;
789 		sh = sctp_hdr(skb);
790 		sin6->sin6_port = sh->source;
791 
792 		/* Map ipv4 address into v4-mapped-on-v6 address. */
793 		if (sctp_sk(skb->sk)->v4mapped &&
794 		    ip_hdr(skb)->version == 4) {
795 			sctp_v4_map_v6((union sctp_addr *)sin6);
796 			sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
797 			return;
798 		}
799 
800 		/* Otherwise, just copy the v6 address. */
801 		ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
802 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
803 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
804 			sin6->sin6_scope_id = ev->iif;
805 		}
806 	}
807 }
808 
809 /* Do we support this AF? */
810 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
811 {
812 	switch (family) {
813 	case AF_INET6:
814 		return 1;
815 	/* v4-mapped-v6 addresses */
816 	case AF_INET:
817 		if (!__ipv6_only_sock(sctp_opt2sk(sp)))
818 			return 1;
819 	default:
820 		return 0;
821 	}
822 }
823 
824 /* Address matching with wildcards allowed.  This extra level
825  * of indirection lets us choose whether a PF_INET6 should
826  * disallow any v4 addresses if we so choose.
827  */
828 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
829 			       const union sctp_addr *addr2,
830 			       struct sctp_sock *opt)
831 {
832 	struct sctp_af *af1, *af2;
833 	struct sock *sk = sctp_opt2sk(opt);
834 
835 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
836 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
837 
838 	if (!af1 || !af2)
839 		return 0;
840 
841 	/* If the socket is IPv6 only, v4 addrs will not match */
842 	if (__ipv6_only_sock(sk) && af1 != af2)
843 		return 0;
844 
845 	/* Today, wildcard AF_INET/AF_INET6. */
846 	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
847 		return 1;
848 
849 	if (addr1->sa.sa_family != addr2->sa.sa_family)
850 		return 0;
851 
852 	return af1->cmp_addr(addr1, addr2);
853 }
854 
855 /* Verify that the provided sockaddr looks bindable.   Common verification,
856  * has already been taken care of.
857  */
858 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
859 {
860 	struct sctp_af *af;
861 
862 	/* ASSERT: address family has already been verified. */
863 	if (addr->sa.sa_family != AF_INET6)
864 		af = sctp_get_af_specific(addr->sa.sa_family);
865 	else {
866 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
867 		struct net_device *dev;
868 
869 		if (type & IPV6_ADDR_LINKLOCAL) {
870 			if (!addr->v6.sin6_scope_id)
871 				return 0;
872 			dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
873 			if (!dev)
874 				return 0;
875 			if (!ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
876 					   dev, 0)) {
877 				dev_put(dev);
878 				return 0;
879 			}
880 			dev_put(dev);
881 		} else if (type == IPV6_ADDR_MAPPED) {
882 			if (!opt->v4mapped)
883 				return 0;
884 		}
885 
886 		af = opt->pf->af;
887 	}
888 	return af->available(addr, opt);
889 }
890 
891 /* Verify that the provided sockaddr looks sendable.   Common verification,
892  * has already been taken care of.
893  */
894 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
895 {
896 	struct sctp_af *af = NULL;
897 
898 	/* ASSERT: address family has already been verified. */
899 	if (addr->sa.sa_family != AF_INET6)
900 		af = sctp_get_af_specific(addr->sa.sa_family);
901 	else {
902 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
903 		struct net_device *dev;
904 
905 		if (type & IPV6_ADDR_LINKLOCAL) {
906 			if (!addr->v6.sin6_scope_id)
907 				return 0;
908 			dev = dev_get_by_index(&init_net, addr->v6.sin6_scope_id);
909 			if (!dev)
910 				return 0;
911 			dev_put(dev);
912 		}
913 		af = opt->pf->af;
914 	}
915 
916 	return af != NULL;
917 }
918 
919 /* Fill in Supported Address Type information for INIT and INIT-ACK
920  * chunks.   Note: In the future, we may want to look at sock options
921  * to determine whether a PF_INET6 socket really wants to have IPV4
922  * addresses.
923  * Returns number of addresses supported.
924  */
925 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
926 				      __be16 *types)
927 {
928 	types[0] = SCTP_PARAM_IPV6_ADDRESS;
929 	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
930 		types[1] = SCTP_PARAM_IPV4_ADDRESS;
931 		return 2;
932 	}
933 	return 1;
934 }
935 
936 static const struct proto_ops inet6_seqpacket_ops = {
937 	.family		   = PF_INET6,
938 	.owner		   = THIS_MODULE,
939 	.release	   = inet6_release,
940 	.bind		   = inet6_bind,
941 	.connect	   = inet_dgram_connect,
942 	.socketpair	   = sock_no_socketpair,
943 	.accept		   = inet_accept,
944 	.getname	   = inet6_getname,
945 	.poll		   = sctp_poll,
946 	.ioctl		   = inet6_ioctl,
947 	.listen		   = sctp_inet_listen,
948 	.shutdown	   = inet_shutdown,
949 	.setsockopt	   = sock_common_setsockopt,
950 	.getsockopt	   = sock_common_getsockopt,
951 	.sendmsg	   = inet_sendmsg,
952 	.recvmsg	   = sock_common_recvmsg,
953 	.mmap		   = sock_no_mmap,
954 #ifdef CONFIG_COMPAT
955 	.compat_setsockopt = compat_sock_common_setsockopt,
956 	.compat_getsockopt = compat_sock_common_getsockopt,
957 #endif
958 };
959 
960 static struct inet_protosw sctpv6_seqpacket_protosw = {
961 	.type          = SOCK_SEQPACKET,
962 	.protocol      = IPPROTO_SCTP,
963 	.prot 	       = &sctpv6_prot,
964 	.ops           = &inet6_seqpacket_ops,
965 	.capability    = -1,
966 	.no_check      = 0,
967 	.flags         = SCTP_PROTOSW_FLAG
968 };
969 static struct inet_protosw sctpv6_stream_protosw = {
970 	.type          = SOCK_STREAM,
971 	.protocol      = IPPROTO_SCTP,
972 	.prot 	       = &sctpv6_prot,
973 	.ops           = &inet6_seqpacket_ops,
974 	.capability    = -1,
975 	.no_check      = 0,
976 	.flags         = SCTP_PROTOSW_FLAG,
977 };
978 
979 static int sctp6_rcv(struct sk_buff *skb)
980 {
981 	return sctp_rcv(skb) ? -1 : 0;
982 }
983 
984 static struct inet6_protocol sctpv6_protocol = {
985 	.handler      = sctp6_rcv,
986 	.err_handler  = sctp_v6_err,
987 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
988 };
989 
990 static struct sctp_af sctp_af_inet6 = {
991 	.sa_family	   = AF_INET6,
992 	.sctp_xmit	   = sctp_v6_xmit,
993 	.setsockopt	   = ipv6_setsockopt,
994 	.getsockopt	   = ipv6_getsockopt,
995 	.get_dst	   = sctp_v6_get_dst,
996 	.get_saddr	   = sctp_v6_get_saddr,
997 	.copy_addrlist	   = sctp_v6_copy_addrlist,
998 	.from_skb	   = sctp_v6_from_skb,
999 	.from_sk	   = sctp_v6_from_sk,
1000 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
1001 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
1002 	.from_addr_param   = sctp_v6_from_addr_param,
1003 	.to_addr_param	   = sctp_v6_to_addr_param,
1004 	.dst_saddr	   = sctp_v6_dst_saddr,
1005 	.cmp_addr	   = sctp_v6_cmp_addr,
1006 	.scope		   = sctp_v6_scope,
1007 	.addr_valid	   = sctp_v6_addr_valid,
1008 	.inaddr_any	   = sctp_v6_inaddr_any,
1009 	.is_any		   = sctp_v6_is_any,
1010 	.available	   = sctp_v6_available,
1011 	.skb_iif	   = sctp_v6_skb_iif,
1012 	.is_ce		   = sctp_v6_is_ce,
1013 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
1014 	.ecn_capable	   = sctp_v6_ecn_capable,
1015 	.net_header_len	   = sizeof(struct ipv6hdr),
1016 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1017 #ifdef CONFIG_COMPAT
1018 	.compat_setsockopt = compat_ipv6_setsockopt,
1019 	.compat_getsockopt = compat_ipv6_getsockopt,
1020 #endif
1021 };
1022 
1023 static struct sctp_pf sctp_pf_inet6 = {
1024 	.event_msgname = sctp_inet6_event_msgname,
1025 	.skb_msgname   = sctp_inet6_skb_msgname,
1026 	.af_supported  = sctp_inet6_af_supported,
1027 	.cmp_addr      = sctp_inet6_cmp_addr,
1028 	.bind_verify   = sctp_inet6_bind_verify,
1029 	.send_verify   = sctp_inet6_send_verify,
1030 	.supported_addrs = sctp_inet6_supported_addrs,
1031 	.create_accept_sk = sctp_v6_create_accept_sk,
1032 	.addr_v4map    = sctp_v6_addr_v4map,
1033 	.af            = &sctp_af_inet6,
1034 };
1035 
1036 /* Initialize IPv6 support and register with socket layer.  */
1037 void sctp_v6_pf_init(void)
1038 {
1039 	/* Register the SCTP specific PF_INET6 functions. */
1040 	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1041 
1042 	/* Register the SCTP specific AF_INET6 functions. */
1043 	sctp_register_af(&sctp_af_inet6);
1044 }
1045 
1046 void sctp_v6_pf_exit(void)
1047 {
1048 	list_del(&sctp_af_inet6.list);
1049 }
1050 
1051 /* Initialize IPv6 support and register with socket layer.  */
1052 int sctp_v6_protosw_init(void)
1053 {
1054 	int rc;
1055 
1056 	rc = proto_register(&sctpv6_prot, 1);
1057 	if (rc)
1058 		return rc;
1059 
1060 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1061 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1062 	inet6_register_protosw(&sctpv6_stream_protosw);
1063 
1064 	return 0;
1065 }
1066 
1067 void sctp_v6_protosw_exit(void)
1068 {
1069 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1070 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1071 	proto_unregister(&sctpv6_prot);
1072 }
1073 
1074 
1075 /* Register with inet6 layer. */
1076 int sctp_v6_add_protocol(void)
1077 {
1078 	/* Register notifier for inet6 address additions/deletions. */
1079 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1080 
1081 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1082 		return -EAGAIN;
1083 
1084 	return 0;
1085 }
1086 
1087 /* Unregister with inet6 layer. */
1088 void sctp_v6_del_protocol(void)
1089 {
1090 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1091 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1092 }
1093