xref: /openbmc/linux/net/sctp/ipv6.c (revision 4800cd83)
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 #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 /* Event handler for inet6 address addition/deletion events.
84  * The sctp_local_addr_list needs to be protocted by a spin lock since
85  * multiple notifiers (say IPv4 and IPv6) may be running at the same
86  * time and thus corrupt the list.
87  * The reader side is protected with RCU.
88  */
89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
90 				void *ptr)
91 {
92 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
93 	struct sctp_sockaddr_entry *addr = NULL;
94 	struct sctp_sockaddr_entry *temp;
95 	int found = 0;
96 
97 	switch (ev) {
98 	case NETDEV_UP:
99 		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
100 		if (addr) {
101 			addr->a.v6.sin6_family = AF_INET6;
102 			addr->a.v6.sin6_port = 0;
103 			ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifa->addr);
104 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
105 			addr->valid = 1;
106 			spin_lock_bh(&sctp_local_addr_lock);
107 			list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
108 			spin_unlock_bh(&sctp_local_addr_lock);
109 		}
110 		break;
111 	case NETDEV_DOWN:
112 		spin_lock_bh(&sctp_local_addr_lock);
113 		list_for_each_entry_safe(addr, temp,
114 					&sctp_local_addr_list, list) {
115 			if (addr->a.sa.sa_family == AF_INET6 &&
116 					ipv6_addr_equal(&addr->a.v6.sin6_addr,
117 						&ifa->addr)) {
118 				found = 1;
119 				addr->valid = 0;
120 				list_del_rcu(&addr->list);
121 				break;
122 			}
123 		}
124 		spin_unlock_bh(&sctp_local_addr_lock);
125 		if (found)
126 			call_rcu(&addr->rcu, sctp_local_addr_free);
127 		break;
128 	}
129 
130 	return NOTIFY_DONE;
131 }
132 
133 static struct notifier_block sctp_inet6addr_notifier = {
134 	.notifier_call = sctp_inet6addr_event,
135 };
136 
137 /* ICMP error handler. */
138 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
139 			     u8 type, u8 code, int offset, __be32 info)
140 {
141 	struct inet6_dev *idev;
142 	struct sock *sk;
143 	struct sctp_association *asoc;
144 	struct sctp_transport *transport;
145 	struct ipv6_pinfo *np;
146 	sk_buff_data_t saveip, savesctp;
147 	int err;
148 
149 	idev = in6_dev_get(skb->dev);
150 
151 	/* Fix up skb to look at the embedded net header. */
152 	saveip	 = skb->network_header;
153 	savesctp = skb->transport_header;
154 	skb_reset_network_header(skb);
155 	skb_set_transport_header(skb, offset);
156 	sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
157 	/* Put back, the original pointers. */
158 	skb->network_header   = saveip;
159 	skb->transport_header = savesctp;
160 	if (!sk) {
161 		ICMP6_INC_STATS_BH(dev_net(skb->dev), idev, ICMP6_MIB_INERRORS);
162 		goto out;
163 	}
164 
165 	/* Warning:  The sock lock is held.  Remember to call
166 	 * sctp_err_finish!
167 	 */
168 
169 	switch (type) {
170 	case ICMPV6_PKT_TOOBIG:
171 		sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
172 		goto out_unlock;
173 	case ICMPV6_PARAMPROB:
174 		if (ICMPV6_UNK_NEXTHDR == code) {
175 			sctp_icmp_proto_unreachable(sk, asoc, transport);
176 			goto out_unlock;
177 		}
178 		break;
179 	default:
180 		break;
181 	}
182 
183 	np = inet6_sk(sk);
184 	icmpv6_err_convert(type, code, &err);
185 	if (!sock_owned_by_user(sk) && np->recverr) {
186 		sk->sk_err = err;
187 		sk->sk_error_report(sk);
188 	} else {  /* Only an error on timeout */
189 		sk->sk_err_soft = err;
190 	}
191 
192 out_unlock:
193 	sctp_err_finish(sk, asoc);
194 out:
195 	if (likely(idev != NULL))
196 		in6_dev_put(idev);
197 }
198 
199 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
200 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
201 {
202 	struct sock *sk = skb->sk;
203 	struct ipv6_pinfo *np = inet6_sk(sk);
204 	struct flowi fl;
205 
206 	memset(&fl, 0, sizeof(fl));
207 
208 	fl.proto = sk->sk_protocol;
209 
210 	/* Fill in the dest address from the route entry passed with the skb
211 	 * and the source address from the transport.
212 	 */
213 	ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
214 	ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
215 
216 	fl.fl6_flowlabel = np->flow_label;
217 	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
218 	if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
219 		fl.oif = transport->saddr.v6.sin6_scope_id;
220 	else
221 		fl.oif = sk->sk_bound_dev_if;
222 
223 	if (np->opt && np->opt->srcrt) {
224 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
225 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
226 	}
227 
228 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
229 			  __func__, skb, skb->len,
230 			  &fl.fl6_src, &fl.fl6_dst);
231 
232 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
233 
234 	if (!(transport->param_flags & SPP_PMTUD_ENABLE))
235 		skb->local_df = 1;
236 
237 	return ip6_xmit(sk, skb, &fl, np->opt);
238 }
239 
240 /* Returns the dst cache entry for the given source and destination ip
241  * addresses.
242  */
243 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
244 					 union sctp_addr *daddr,
245 					 union sctp_addr *saddr)
246 {
247 	struct dst_entry *dst;
248 	struct flowi fl;
249 
250 	memset(&fl, 0, sizeof(fl));
251 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
252 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
253 		fl.oif = daddr->v6.sin6_scope_id;
254 
255 
256 	SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl.fl6_dst);
257 
258 	if (saddr) {
259 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
260 		SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl.fl6_src);
261 	}
262 
263 	dst = ip6_route_output(&init_net, NULL, &fl);
264 	if (!dst->error) {
265 		struct rt6_info *rt;
266 		rt = (struct rt6_info *)dst;
267 		SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
268 			&rt->rt6i_dst.addr, &rt->rt6i_src.addr);
269 		return dst;
270 	}
271 	SCTP_DEBUG_PRINTK("NO ROUTE\n");
272 	dst_release(dst);
273 	return NULL;
274 }
275 
276 /* Returns the number of consecutive initial bits that match in the 2 ipv6
277  * addresses.
278  */
279 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
280 					 union sctp_addr *s2)
281 {
282 	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
283 }
284 
285 /* Fills in the source address(saddr) based on the destination address(daddr)
286  * and asoc's bind address list.
287  */
288 static void sctp_v6_get_saddr(struct sctp_sock *sk,
289 			      struct sctp_association *asoc,
290 			      struct dst_entry *dst,
291 			      union sctp_addr *daddr,
292 			      union sctp_addr *saddr)
293 {
294 	struct sctp_bind_addr *bp;
295 	struct sctp_sockaddr_entry *laddr;
296 	sctp_scope_t scope;
297 	union sctp_addr *baddr = NULL;
298 	__u8 matchlen = 0;
299 	__u8 bmatchlen;
300 
301 	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p daddr:%pI6 ",
302 			  __func__, asoc, dst, &daddr->v6.sin6_addr);
303 
304 	if (!asoc) {
305 		ipv6_dev_get_saddr(sock_net(sctp_opt2sk(sk)),
306 				   dst ? ip6_dst_idev(dst)->dev : NULL,
307 				   &daddr->v6.sin6_addr,
308 				   inet6_sk(&sk->inet.sk)->srcprefs,
309 				   &saddr->v6.sin6_addr);
310 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: %pI6\n",
311 				  &saddr->v6.sin6_addr);
312 		return;
313 	}
314 
315 	scope = sctp_scope(daddr);
316 
317 	bp = &asoc->base.bind_addr;
318 
319 	/* Go through the bind address list and find the best source address
320 	 * that matches the scope of the destination address.
321 	 */
322 	rcu_read_lock();
323 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
324 		if (!laddr->valid)
325 			continue;
326 		if ((laddr->state == SCTP_ADDR_SRC) &&
327 		    (laddr->a.sa.sa_family == AF_INET6) &&
328 		    (scope <= sctp_scope(&laddr->a))) {
329 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
330 			if (!baddr || (matchlen < bmatchlen)) {
331 				baddr = &laddr->a;
332 				matchlen = bmatchlen;
333 			}
334 		}
335 	}
336 
337 	if (baddr) {
338 		memcpy(saddr, baddr, sizeof(union sctp_addr));
339 		SCTP_DEBUG_PRINTK("saddr: %pI6\n", &saddr->v6.sin6_addr);
340 	} else {
341 		pr_err("%s: asoc:%p Could not find a valid source "
342 		       "address for the dest:%pI6\n",
343 		       __func__, asoc, &daddr->v6.sin6_addr);
344 	}
345 
346 	rcu_read_unlock();
347 }
348 
349 /* Make a copy of all potential local addresses. */
350 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
351 				  struct net_device *dev)
352 {
353 	struct inet6_dev *in6_dev;
354 	struct inet6_ifaddr *ifp;
355 	struct sctp_sockaddr_entry *addr;
356 
357 	rcu_read_lock();
358 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
359 		rcu_read_unlock();
360 		return;
361 	}
362 
363 	read_lock_bh(&in6_dev->lock);
364 	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
365 		/* Add the address to the local list.  */
366 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
367 		if (addr) {
368 			addr->a.v6.sin6_family = AF_INET6;
369 			addr->a.v6.sin6_port = 0;
370 			ipv6_addr_copy(&addr->a.v6.sin6_addr, &ifp->addr);
371 			addr->a.v6.sin6_scope_id = dev->ifindex;
372 			addr->valid = 1;
373 			INIT_LIST_HEAD(&addr->list);
374 			list_add_tail(&addr->list, addrlist);
375 		}
376 	}
377 
378 	read_unlock_bh(&in6_dev->lock);
379 	rcu_read_unlock();
380 }
381 
382 /* Initialize a sockaddr_storage from in incoming skb. */
383 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
384 			     int is_saddr)
385 {
386 	void *from;
387 	__be16 *port;
388 	struct sctphdr *sh;
389 
390 	port = &addr->v6.sin6_port;
391 	addr->v6.sin6_family = AF_INET6;
392 	addr->v6.sin6_flowinfo = 0; /* FIXME */
393 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
394 
395 	sh = sctp_hdr(skb);
396 	if (is_saddr) {
397 		*port  = sh->source;
398 		from = &ipv6_hdr(skb)->saddr;
399 	} else {
400 		*port = sh->dest;
401 		from = &ipv6_hdr(skb)->daddr;
402 	}
403 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
404 }
405 
406 /* Initialize an sctp_addr from a socket. */
407 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
408 {
409 	addr->v6.sin6_family = AF_INET6;
410 	addr->v6.sin6_port = 0;
411 	ipv6_addr_copy(&addr->v6.sin6_addr, &inet6_sk(sk)->rcv_saddr);
412 }
413 
414 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
415 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
416 {
417 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
418 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
419 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
420 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
421 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
422 			addr->v4.sin_addr.s_addr;
423 	} else {
424 		ipv6_addr_copy(&inet6_sk(sk)->rcv_saddr, &addr->v6.sin6_addr);
425 	}
426 }
427 
428 /* Initialize sk->sk_daddr from sctp_addr. */
429 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
430 {
431 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
432 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
433 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
434 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
435 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
436 	} else {
437 		ipv6_addr_copy(&inet6_sk(sk)->daddr, &addr->v6.sin6_addr);
438 	}
439 }
440 
441 /* Initialize a sctp_addr from an address parameter. */
442 static void sctp_v6_from_addr_param(union sctp_addr *addr,
443 				    union sctp_addr_param *param,
444 				    __be16 port, int iif)
445 {
446 	addr->v6.sin6_family = AF_INET6;
447 	addr->v6.sin6_port = port;
448 	addr->v6.sin6_flowinfo = 0; /* BUG */
449 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
450 	addr->v6.sin6_scope_id = iif;
451 }
452 
453 /* Initialize an address parameter from a sctp_addr and return the length
454  * of the address parameter.
455  */
456 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
457 				 union sctp_addr_param *param)
458 {
459 	int length = sizeof(sctp_ipv6addr_param_t);
460 
461 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
462 	param->v6.param_hdr.length = htons(length);
463 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
464 
465 	return length;
466 }
467 
468 /* Initialize a sctp_addr from a dst_entry. */
469 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
470 			      __be16 port)
471 {
472 	struct rt6_info *rt = (struct rt6_info *)dst;
473 	addr->sa.sa_family = AF_INET6;
474 	addr->v6.sin6_port = port;
475 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
476 }
477 
478 /* Compare addresses exactly.
479  * v4-mapped-v6 is also in consideration.
480  */
481 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
482 			    const union sctp_addr *addr2)
483 {
484 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
485 		if (addr1->sa.sa_family == AF_INET &&
486 		    addr2->sa.sa_family == AF_INET6 &&
487 		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) {
488 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
489 			    addr2->v6.sin6_addr.s6_addr32[3] ==
490 			    addr1->v4.sin_addr.s_addr)
491 				return 1;
492 		}
493 		if (addr2->sa.sa_family == AF_INET &&
494 		    addr1->sa.sa_family == AF_INET6 &&
495 		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) {
496 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
497 			    addr1->v6.sin6_addr.s6_addr32[3] ==
498 			    addr2->v4.sin_addr.s_addr)
499 				return 1;
500 		}
501 		return 0;
502 	}
503 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
504 		return 0;
505 	/* If this is a linklocal address, compare the scope_id. */
506 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
507 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
508 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
509 			return 0;
510 		}
511 	}
512 
513 	return 1;
514 }
515 
516 /* Initialize addr struct to INADDR_ANY. */
517 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
518 {
519 	memset(addr, 0x00, sizeof(union sctp_addr));
520 	addr->v6.sin6_family = AF_INET6;
521 	addr->v6.sin6_port = port;
522 }
523 
524 /* Is this a wildcard address? */
525 static int sctp_v6_is_any(const union sctp_addr *addr)
526 {
527 	return ipv6_addr_any(&addr->v6.sin6_addr);
528 }
529 
530 /* Should this be available for binding?   */
531 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
532 {
533 	int type;
534 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
535 
536 	type = ipv6_addr_type(in6);
537 	if (IPV6_ADDR_ANY == type)
538 		return 1;
539 	if (type == IPV6_ADDR_MAPPED) {
540 		if (sp && !sp->v4mapped)
541 			return 0;
542 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
543 			return 0;
544 		sctp_v6_map_v4(addr);
545 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
546 	}
547 	if (!(type & IPV6_ADDR_UNICAST))
548 		return 0;
549 
550 	return ipv6_chk_addr(&init_net, in6, NULL, 0);
551 }
552 
553 /* This function checks if the address is a valid address to be used for
554  * SCTP.
555  *
556  * Output:
557  * Return 0 - If the address is a non-unicast or an illegal address.
558  * Return 1 - If the address is a unicast.
559  */
560 static int sctp_v6_addr_valid(union sctp_addr *addr,
561 			      struct sctp_sock *sp,
562 			      const struct sk_buff *skb)
563 {
564 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
565 
566 	/* Support v4-mapped-v6 address. */
567 	if (ret == IPV6_ADDR_MAPPED) {
568 		/* Note: This routine is used in input, so v4-mapped-v6
569 		 * are disallowed here when there is no sctp_sock.
570 		 */
571 		if (!sp || !sp->v4mapped)
572 			return 0;
573 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
574 			return 0;
575 		sctp_v6_map_v4(addr);
576 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
577 	}
578 
579 	/* Is this a non-unicast address */
580 	if (!(ret & IPV6_ADDR_UNICAST))
581 		return 0;
582 
583 	return 1;
584 }
585 
586 /* What is the scope of 'addr'?  */
587 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
588 {
589 	int v6scope;
590 	sctp_scope_t retval;
591 
592 	/* The IPv6 scope is really a set of bit fields.
593 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
594 	 */
595 
596 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
597 	switch (v6scope) {
598 	case IFA_HOST:
599 		retval = SCTP_SCOPE_LOOPBACK;
600 		break;
601 	case IFA_LINK:
602 		retval = SCTP_SCOPE_LINK;
603 		break;
604 	case IFA_SITE:
605 		retval = SCTP_SCOPE_PRIVATE;
606 		break;
607 	default:
608 		retval = SCTP_SCOPE_GLOBAL;
609 		break;
610 	}
611 
612 	return retval;
613 }
614 
615 /* Create and initialize a new sk for the socket to be returned by accept(). */
616 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
617 					     struct sctp_association *asoc)
618 {
619 	struct sock *newsk;
620 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
621 	struct sctp6_sock *newsctp6sk;
622 
623 	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot);
624 	if (!newsk)
625 		goto out;
626 
627 	sock_init_data(NULL, newsk);
628 
629 	sctp_copy_sock(newsk, sk, asoc);
630 	sock_reset_flag(sk, SOCK_ZAPPED);
631 
632 	newsctp6sk = (struct sctp6_sock *)newsk;
633 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
634 
635 	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
636 
637 	newnp = inet6_sk(newsk);
638 
639 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
640 
641 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
642 	 * and getpeername().
643 	 */
644 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
645 
646 	sk_refcnt_debug_inc(newsk);
647 
648 	if (newsk->sk_prot->init(newsk)) {
649 		sk_common_release(newsk);
650 		newsk = NULL;
651 	}
652 
653 out:
654 	return newsk;
655 }
656 
657 /* Map v4 address to mapped v6 address */
658 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
659 {
660 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
661 		sctp_v4_map_v6(addr);
662 }
663 
664 /* Where did this skb come from?  */
665 static int sctp_v6_skb_iif(const struct sk_buff *skb)
666 {
667 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
668 	return opt->iif;
669 }
670 
671 /* Was this packet marked by Explicit Congestion Notification? */
672 static int sctp_v6_is_ce(const struct sk_buff *skb)
673 {
674 	return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
675 }
676 
677 /* Dump the v6 addr to the seq file. */
678 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
679 {
680 	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
681 }
682 
683 static void sctp_v6_ecn_capable(struct sock *sk)
684 {
685 	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
686 }
687 
688 /* Initialize a PF_INET6 socket msg_name. */
689 static void sctp_inet6_msgname(char *msgname, int *addr_len)
690 {
691 	struct sockaddr_in6 *sin6;
692 
693 	sin6 = (struct sockaddr_in6 *)msgname;
694 	sin6->sin6_family = AF_INET6;
695 	sin6->sin6_flowinfo = 0;
696 	sin6->sin6_scope_id = 0; /*FIXME */
697 	*addr_len = sizeof(struct sockaddr_in6);
698 }
699 
700 /* Initialize a PF_INET msgname from a ulpevent. */
701 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
702 				     char *msgname, int *addrlen)
703 {
704 	struct sockaddr_in6 *sin6, *sin6from;
705 
706 	if (msgname) {
707 		union sctp_addr *addr;
708 		struct sctp_association *asoc;
709 
710 		asoc = event->asoc;
711 		sctp_inet6_msgname(msgname, addrlen);
712 		sin6 = (struct sockaddr_in6 *)msgname;
713 		sin6->sin6_port = htons(asoc->peer.port);
714 		addr = &asoc->peer.primary_addr;
715 
716 		/* Note: If we go to a common v6 format, this code
717 		 * will change.
718 		 */
719 
720 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
721 		if (sctp_sk(asoc->base.sk)->v4mapped &&
722 		    AF_INET == addr->sa.sa_family) {
723 			sctp_v4_map_v6((union sctp_addr *)sin6);
724 			sin6->sin6_addr.s6_addr32[3] =
725 				addr->v4.sin_addr.s_addr;
726 			return;
727 		}
728 
729 		sin6from = &asoc->peer.primary_addr.v6;
730 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
731 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
732 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
733 	}
734 }
735 
736 /* Initialize a msg_name from an inbound skb. */
737 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
738 				   int *addr_len)
739 {
740 	struct sctphdr *sh;
741 	struct sockaddr_in6 *sin6;
742 
743 	if (msgname) {
744 		sctp_inet6_msgname(msgname, addr_len);
745 		sin6 = (struct sockaddr_in6 *)msgname;
746 		sh = sctp_hdr(skb);
747 		sin6->sin6_port = sh->source;
748 
749 		/* Map ipv4 address into v4-mapped-on-v6 address. */
750 		if (sctp_sk(skb->sk)->v4mapped &&
751 		    ip_hdr(skb)->version == 4) {
752 			sctp_v4_map_v6((union sctp_addr *)sin6);
753 			sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
754 			return;
755 		}
756 
757 		/* Otherwise, just copy the v6 address. */
758 		ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
759 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
760 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
761 			sin6->sin6_scope_id = ev->iif;
762 		}
763 	}
764 }
765 
766 /* Do we support this AF? */
767 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
768 {
769 	switch (family) {
770 	case AF_INET6:
771 		return 1;
772 	/* v4-mapped-v6 addresses */
773 	case AF_INET:
774 		if (!__ipv6_only_sock(sctp_opt2sk(sp)))
775 			return 1;
776 	default:
777 		return 0;
778 	}
779 }
780 
781 /* Address matching with wildcards allowed.  This extra level
782  * of indirection lets us choose whether a PF_INET6 should
783  * disallow any v4 addresses if we so choose.
784  */
785 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
786 			       const union sctp_addr *addr2,
787 			       struct sctp_sock *opt)
788 {
789 	struct sctp_af *af1, *af2;
790 	struct sock *sk = sctp_opt2sk(opt);
791 
792 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
793 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
794 
795 	if (!af1 || !af2)
796 		return 0;
797 
798 	/* If the socket is IPv6 only, v4 addrs will not match */
799 	if (__ipv6_only_sock(sk) && af1 != af2)
800 		return 0;
801 
802 	/* Today, wildcard AF_INET/AF_INET6. */
803 	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
804 		return 1;
805 
806 	if (addr1->sa.sa_family != addr2->sa.sa_family)
807 		return 0;
808 
809 	return af1->cmp_addr(addr1, addr2);
810 }
811 
812 /* Verify that the provided sockaddr looks bindable.   Common verification,
813  * has already been taken care of.
814  */
815 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
816 {
817 	struct sctp_af *af;
818 
819 	/* ASSERT: address family has already been verified. */
820 	if (addr->sa.sa_family != AF_INET6)
821 		af = sctp_get_af_specific(addr->sa.sa_family);
822 	else {
823 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
824 		struct net_device *dev;
825 
826 		if (type & IPV6_ADDR_LINKLOCAL) {
827 			if (!addr->v6.sin6_scope_id)
828 				return 0;
829 			rcu_read_lock();
830 			dev = dev_get_by_index_rcu(&init_net,
831 						   addr->v6.sin6_scope_id);
832 			if (!dev ||
833 			    !ipv6_chk_addr(&init_net, &addr->v6.sin6_addr,
834 					   dev, 0)) {
835 				rcu_read_unlock();
836 				return 0;
837 			}
838 			rcu_read_unlock();
839 		} else if (type == IPV6_ADDR_MAPPED) {
840 			if (!opt->v4mapped)
841 				return 0;
842 		}
843 
844 		af = opt->pf->af;
845 	}
846 	return af->available(addr, opt);
847 }
848 
849 /* Verify that the provided sockaddr looks sendable.   Common verification,
850  * has already been taken care of.
851  */
852 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
853 {
854 	struct sctp_af *af = NULL;
855 
856 	/* ASSERT: address family has already been verified. */
857 	if (addr->sa.sa_family != AF_INET6)
858 		af = sctp_get_af_specific(addr->sa.sa_family);
859 	else {
860 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
861 		struct net_device *dev;
862 
863 		if (type & IPV6_ADDR_LINKLOCAL) {
864 			if (!addr->v6.sin6_scope_id)
865 				return 0;
866 			rcu_read_lock();
867 			dev = dev_get_by_index_rcu(&init_net,
868 						   addr->v6.sin6_scope_id);
869 			rcu_read_unlock();
870 			if (!dev)
871 				return 0;
872 		}
873 		af = opt->pf->af;
874 	}
875 
876 	return af != NULL;
877 }
878 
879 /* Fill in Supported Address Type information for INIT and INIT-ACK
880  * chunks.   Note: In the future, we may want to look at sock options
881  * to determine whether a PF_INET6 socket really wants to have IPV4
882  * addresses.
883  * Returns number of addresses supported.
884  */
885 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
886 				      __be16 *types)
887 {
888 	types[0] = SCTP_PARAM_IPV6_ADDRESS;
889 	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
890 		types[1] = SCTP_PARAM_IPV4_ADDRESS;
891 		return 2;
892 	}
893 	return 1;
894 }
895 
896 static const struct proto_ops inet6_seqpacket_ops = {
897 	.family		   = PF_INET6,
898 	.owner		   = THIS_MODULE,
899 	.release	   = inet6_release,
900 	.bind		   = inet6_bind,
901 	.connect	   = inet_dgram_connect,
902 	.socketpair	   = sock_no_socketpair,
903 	.accept		   = inet_accept,
904 	.getname	   = inet6_getname,
905 	.poll		   = sctp_poll,
906 	.ioctl		   = inet6_ioctl,
907 	.listen		   = sctp_inet_listen,
908 	.shutdown	   = inet_shutdown,
909 	.setsockopt	   = sock_common_setsockopt,
910 	.getsockopt	   = sock_common_getsockopt,
911 	.sendmsg	   = inet_sendmsg,
912 	.recvmsg	   = sock_common_recvmsg,
913 	.mmap		   = sock_no_mmap,
914 #ifdef CONFIG_COMPAT
915 	.compat_setsockopt = compat_sock_common_setsockopt,
916 	.compat_getsockopt = compat_sock_common_getsockopt,
917 #endif
918 };
919 
920 static struct inet_protosw sctpv6_seqpacket_protosw = {
921 	.type          = SOCK_SEQPACKET,
922 	.protocol      = IPPROTO_SCTP,
923 	.prot 	       = &sctpv6_prot,
924 	.ops           = &inet6_seqpacket_ops,
925 	.no_check      = 0,
926 	.flags         = SCTP_PROTOSW_FLAG
927 };
928 static struct inet_protosw sctpv6_stream_protosw = {
929 	.type          = SOCK_STREAM,
930 	.protocol      = IPPROTO_SCTP,
931 	.prot 	       = &sctpv6_prot,
932 	.ops           = &inet6_seqpacket_ops,
933 	.no_check      = 0,
934 	.flags         = SCTP_PROTOSW_FLAG,
935 };
936 
937 static int sctp6_rcv(struct sk_buff *skb)
938 {
939 	return sctp_rcv(skb) ? -1 : 0;
940 }
941 
942 static const struct inet6_protocol sctpv6_protocol = {
943 	.handler      = sctp6_rcv,
944 	.err_handler  = sctp_v6_err,
945 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
946 };
947 
948 static struct sctp_af sctp_af_inet6 = {
949 	.sa_family	   = AF_INET6,
950 	.sctp_xmit	   = sctp_v6_xmit,
951 	.setsockopt	   = ipv6_setsockopt,
952 	.getsockopt	   = ipv6_getsockopt,
953 	.get_dst	   = sctp_v6_get_dst,
954 	.get_saddr	   = sctp_v6_get_saddr,
955 	.copy_addrlist	   = sctp_v6_copy_addrlist,
956 	.from_skb	   = sctp_v6_from_skb,
957 	.from_sk	   = sctp_v6_from_sk,
958 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
959 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
960 	.from_addr_param   = sctp_v6_from_addr_param,
961 	.to_addr_param	   = sctp_v6_to_addr_param,
962 	.dst_saddr	   = sctp_v6_dst_saddr,
963 	.cmp_addr	   = sctp_v6_cmp_addr,
964 	.scope		   = sctp_v6_scope,
965 	.addr_valid	   = sctp_v6_addr_valid,
966 	.inaddr_any	   = sctp_v6_inaddr_any,
967 	.is_any		   = sctp_v6_is_any,
968 	.available	   = sctp_v6_available,
969 	.skb_iif	   = sctp_v6_skb_iif,
970 	.is_ce		   = sctp_v6_is_ce,
971 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
972 	.ecn_capable	   = sctp_v6_ecn_capable,
973 	.net_header_len	   = sizeof(struct ipv6hdr),
974 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
975 #ifdef CONFIG_COMPAT
976 	.compat_setsockopt = compat_ipv6_setsockopt,
977 	.compat_getsockopt = compat_ipv6_getsockopt,
978 #endif
979 };
980 
981 static struct sctp_pf sctp_pf_inet6 = {
982 	.event_msgname = sctp_inet6_event_msgname,
983 	.skb_msgname   = sctp_inet6_skb_msgname,
984 	.af_supported  = sctp_inet6_af_supported,
985 	.cmp_addr      = sctp_inet6_cmp_addr,
986 	.bind_verify   = sctp_inet6_bind_verify,
987 	.send_verify   = sctp_inet6_send_verify,
988 	.supported_addrs = sctp_inet6_supported_addrs,
989 	.create_accept_sk = sctp_v6_create_accept_sk,
990 	.addr_v4map    = sctp_v6_addr_v4map,
991 	.af            = &sctp_af_inet6,
992 };
993 
994 /* Initialize IPv6 support and register with socket layer.  */
995 void sctp_v6_pf_init(void)
996 {
997 	/* Register the SCTP specific PF_INET6 functions. */
998 	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
999 
1000 	/* Register the SCTP specific AF_INET6 functions. */
1001 	sctp_register_af(&sctp_af_inet6);
1002 }
1003 
1004 void sctp_v6_pf_exit(void)
1005 {
1006 	list_del(&sctp_af_inet6.list);
1007 }
1008 
1009 /* Initialize IPv6 support and register with socket layer.  */
1010 int sctp_v6_protosw_init(void)
1011 {
1012 	int rc;
1013 
1014 	rc = proto_register(&sctpv6_prot, 1);
1015 	if (rc)
1016 		return rc;
1017 
1018 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1019 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1020 	inet6_register_protosw(&sctpv6_stream_protosw);
1021 
1022 	return 0;
1023 }
1024 
1025 void sctp_v6_protosw_exit(void)
1026 {
1027 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1028 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1029 	proto_unregister(&sctpv6_prot);
1030 }
1031 
1032 
1033 /* Register with inet6 layer. */
1034 int sctp_v6_add_protocol(void)
1035 {
1036 	/* Register notifier for inet6 address additions/deletions. */
1037 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1038 
1039 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1040 		return -EAGAIN;
1041 
1042 	return 0;
1043 }
1044 
1045 /* Unregister with inet6 layer. */
1046 void sctp_v6_del_protocol(void)
1047 {
1048 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1049 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1050 }
1051