xref: /linux/net/sctp/ipv6.c (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1)
1 /* SCTP kernel reference 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 reference Implementation
8  *
9  * SCTP over IPv6.
10  *
11  * The SCTP reference 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  * The SCTP reference 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/sched.h>
57 #include <linux/in.h>
58 #include <linux/in6.h>
59 #include <linux/netdevice.h>
60 #include <linux/init.h>
61 #include <linux/ipsec.h>
62 
63 #include <linux/ipv6.h>
64 #include <linux/icmpv6.h>
65 #include <linux/random.h>
66 #include <linux/seq_file.h>
67 
68 #include <net/protocol.h>
69 #include <net/ndisc.h>
70 #include <net/ip.h>
71 #include <net/ipv6.h>
72 #include <net/transp_v6.h>
73 #include <net/addrconf.h>
74 #include <net/ip6_route.h>
75 #include <net/inet_common.h>
76 #include <net/inet_ecn.h>
77 #include <net/sctp/sctp.h>
78 
79 #include <asm/uaccess.h>
80 
81 extern int sctp_inetaddr_event(struct notifier_block *, unsigned long, void *);
82 static struct notifier_block sctp_inet6addr_notifier = {
83 	.notifier_call = sctp_inetaddr_event,
84 };
85 
86 /* ICMP error handler. */
87 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
88 			     int type, int code, int offset, __u32 info)
89 {
90 	struct inet6_dev *idev;
91 	struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
92 	struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
93 	struct sock *sk;
94 	struct sctp_association *asoc;
95 	struct sctp_transport *transport;
96 	struct ipv6_pinfo *np;
97 	char *saveip, *savesctp;
98 	int err;
99 
100 	idev = in6_dev_get(skb->dev);
101 
102 	/* Fix up skb to look at the embedded net header. */
103 	saveip = skb->nh.raw;
104 	savesctp  = skb->h.raw;
105 	skb->nh.ipv6h = iph;
106 	skb->h.raw = (char *)sh;
107 	sk = sctp_err_lookup(AF_INET6, skb, sh, &asoc, &transport);
108 	/* Put back, the original pointers. */
109 	skb->nh.raw = saveip;
110 	skb->h.raw = savesctp;
111 	if (!sk) {
112 		ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
113 		goto out;
114 	}
115 
116 	/* Warning:  The sock lock is held.  Remember to call
117 	 * sctp_err_finish!
118 	 */
119 
120 	switch (type) {
121 	case ICMPV6_PKT_TOOBIG:
122 		sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
123 		goto out_unlock;
124 	case ICMPV6_PARAMPROB:
125 		if (ICMPV6_UNK_NEXTHDR == code) {
126 			sctp_icmp_proto_unreachable(sk, asoc, transport);
127 			goto out_unlock;
128 		}
129 		break;
130 	default:
131 		break;
132 	}
133 
134 	np = inet6_sk(sk);
135 	icmpv6_err_convert(type, code, &err);
136 	if (!sock_owned_by_user(sk) && np->recverr) {
137 		sk->sk_err = err;
138 		sk->sk_error_report(sk);
139 	} else {  /* Only an error on timeout */
140 		sk->sk_err_soft = err;
141 	}
142 
143 out_unlock:
144 	sctp_err_finish(sk, asoc);
145 out:
146 	if (likely(idev != NULL))
147 		in6_dev_put(idev);
148 }
149 
150 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
151 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
152 			int ipfragok)
153 {
154 	struct sock *sk = skb->sk;
155 	struct ipv6_pinfo *np = inet6_sk(sk);
156 	struct flowi fl;
157 
158 	memset(&fl, 0, sizeof(fl));
159 
160 	fl.proto = sk->sk_protocol;
161 
162 	/* Fill in the dest address from the route entry passed with the skb
163 	 * and the source address from the transport.
164 	 */
165 	ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
166 	ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
167 
168 	fl.fl6_flowlabel = np->flow_label;
169 	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
170 	if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
171 		fl.oif = transport->saddr.v6.sin6_scope_id;
172 	else
173 		fl.oif = sk->sk_bound_dev_if;
174 	fl.fl_ip_sport = inet_sk(sk)->sport;
175 	fl.fl_ip_dport = transport->ipaddr.v6.sin6_port;
176 
177 	if (np->opt && np->opt->srcrt) {
178 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
179 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
180 	}
181 
182 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
183 			  "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
184 			  __FUNCTION__, skb, skb->len,
185 			  NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
186 
187 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
188 
189 	return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
190 }
191 
192 /* Returns the dst cache entry for the given source and destination ip
193  * addresses.
194  */
195 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
196 					 union sctp_addr *daddr,
197 					 union sctp_addr *saddr)
198 {
199 	struct dst_entry *dst;
200 	struct flowi fl;
201 
202 	memset(&fl, 0, sizeof(fl));
203 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
204 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
205 		fl.oif = daddr->v6.sin6_scope_id;
206 
207 
208 	SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
209 			  __FUNCTION__, NIP6(fl.fl6_dst));
210 
211 	if (saddr) {
212 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
213 		SCTP_DEBUG_PRINTK(
214 			"SRC=" NIP6_FMT " - ",
215 			NIP6(fl.fl6_src));
216 	}
217 
218 	dst = ip6_route_output(NULL, &fl);
219 	if (dst) {
220 		struct rt6_info *rt;
221 		rt = (struct rt6_info *)dst;
222 		SCTP_DEBUG_PRINTK(
223 			"rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
224 			NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
225 	} else {
226 		SCTP_DEBUG_PRINTK("NO ROUTE\n");
227 	}
228 
229 	return dst;
230 }
231 
232 /* Returns the number of consecutive initial bits that match in the 2 ipv6
233  * addresses.
234  */
235 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
236 					 union sctp_addr *s2)
237 {
238 	struct in6_addr *a1 = &s1->v6.sin6_addr;
239 	struct in6_addr *a2 = &s2->v6.sin6_addr;
240 	int i, j;
241 
242 	for (i = 0; i < 4 ; i++) {
243 		__u32 a1xora2;
244 
245 		a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
246 
247 		if ((j = fls(ntohl(a1xora2))))
248 			return (i * 32 + 32 - j);
249 	}
250 
251 	return (i*32);
252 }
253 
254 /* Fills in the source address(saddr) based on the destination address(daddr)
255  * and asoc's bind address list.
256  */
257 static void sctp_v6_get_saddr(struct sctp_association *asoc,
258 			      struct dst_entry *dst,
259 			      union sctp_addr *daddr,
260 			      union sctp_addr *saddr)
261 {
262 	struct sctp_bind_addr *bp;
263 	rwlock_t *addr_lock;
264 	struct sctp_sockaddr_entry *laddr;
265 	struct list_head *pos;
266 	sctp_scope_t scope;
267 	union sctp_addr *baddr = NULL;
268 	__u8 matchlen = 0;
269 	__u8 bmatchlen;
270 
271 	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
272 			  "daddr:" NIP6_FMT " ",
273 			  __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
274 
275 	if (!asoc) {
276 		ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
277 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
278 				  NIP6(saddr->v6.sin6_addr));
279 		return;
280 	}
281 
282 	scope = sctp_scope(daddr);
283 
284 	bp = &asoc->base.bind_addr;
285 	addr_lock = &asoc->base.addr_lock;
286 
287 	/* Go through the bind address list and find the best source address
288 	 * that matches the scope of the destination address.
289 	 */
290 	sctp_read_lock(addr_lock);
291 	list_for_each(pos, &bp->address_list) {
292 		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
293 		if ((laddr->use_as_src) &&
294 		    (laddr->a.sa.sa_family == AF_INET6) &&
295 		    (scope <= sctp_scope(&laddr->a))) {
296 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
297 			if (!baddr || (matchlen < bmatchlen)) {
298 				baddr = &laddr->a;
299 				matchlen = bmatchlen;
300 			}
301 		}
302 	}
303 
304 	if (baddr) {
305 		memcpy(saddr, baddr, sizeof(union sctp_addr));
306 		SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
307 				  NIP6(saddr->v6.sin6_addr));
308 	} else {
309 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
310 		       "address for the dest:" NIP6_FMT "\n",
311 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
312 	}
313 
314 	sctp_read_unlock(addr_lock);
315 }
316 
317 /* Make a copy of all potential local addresses. */
318 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
319 				  struct net_device *dev)
320 {
321 	struct inet6_dev *in6_dev;
322 	struct inet6_ifaddr *ifp;
323 	struct sctp_sockaddr_entry *addr;
324 
325 	read_lock(&addrconf_lock);
326 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
327 		read_unlock(&addrconf_lock);
328 		return;
329 	}
330 
331 	read_lock(&in6_dev->lock);
332 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
333 		/* Add the address to the local list.  */
334 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
335 		if (addr) {
336 			addr->a.v6.sin6_family = AF_INET6;
337 			addr->a.v6.sin6_port = 0;
338 			addr->a.v6.sin6_addr = ifp->addr;
339 			addr->a.v6.sin6_scope_id = dev->ifindex;
340 			INIT_LIST_HEAD(&addr->list);
341 			list_add_tail(&addr->list, addrlist);
342 		}
343 	}
344 
345 	read_unlock(&in6_dev->lock);
346 	read_unlock(&addrconf_lock);
347 }
348 
349 /* Initialize a sockaddr_storage from in incoming skb. */
350 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
351 			     int is_saddr)
352 {
353 	void *from;
354 	__u16 *port;
355 	struct sctphdr *sh;
356 
357 	port = &addr->v6.sin6_port;
358 	addr->v6.sin6_family = AF_INET6;
359 	addr->v6.sin6_flowinfo = 0; /* FIXME */
360 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
361 
362 	sh = (struct sctphdr *) skb->h.raw;
363 	if (is_saddr) {
364 		*port  = ntohs(sh->source);
365 		from = &skb->nh.ipv6h->saddr;
366 	} else {
367 		*port = ntohs(sh->dest);
368 		from = &skb->nh.ipv6h->daddr;
369 	}
370 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
371 }
372 
373 /* Initialize an sctp_addr from a socket. */
374 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
375 {
376 	addr->v6.sin6_family = AF_INET6;
377 	addr->v6.sin6_port = inet_sk(sk)->num;
378 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
379 }
380 
381 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
382 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
383 {
384 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
385 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
386 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
387 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
388 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
389 			addr->v4.sin_addr.s_addr;
390 	} else {
391 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
392 	}
393 }
394 
395 /* Initialize sk->sk_daddr from sctp_addr. */
396 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
397 {
398 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
399 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
400 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
401 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
402 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
403 	} else {
404 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
405 	}
406 }
407 
408 /* Initialize a sctp_addr from an address parameter. */
409 static void sctp_v6_from_addr_param(union sctp_addr *addr,
410 				    union sctp_addr_param *param,
411 				    __u16 port, int iif)
412 {
413 	addr->v6.sin6_family = AF_INET6;
414 	addr->v6.sin6_port = port;
415 	addr->v6.sin6_flowinfo = 0; /* BUG */
416 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
417 	addr->v6.sin6_scope_id = iif;
418 }
419 
420 /* Initialize an address parameter from a sctp_addr and return the length
421  * of the address parameter.
422  */
423 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
424 				 union sctp_addr_param *param)
425 {
426 	int length = sizeof(sctp_ipv6addr_param_t);
427 
428 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
429 	param->v6.param_hdr.length = ntohs(length);
430 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
431 
432 	return length;
433 }
434 
435 /* Initialize a sctp_addr from a dst_entry. */
436 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
437 			      unsigned short port)
438 {
439 	struct rt6_info *rt = (struct rt6_info *)dst;
440 	addr->sa.sa_family = AF_INET6;
441 	addr->v6.sin6_port = port;
442 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
443 }
444 
445 /* Compare addresses exactly.
446  * v4-mapped-v6 is also in consideration.
447  */
448 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
449 			    const union sctp_addr *addr2)
450 {
451 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
452 		if (addr1->sa.sa_family == AF_INET &&
453 		    addr2->sa.sa_family == AF_INET6 &&
454 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
455 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
456 			    addr2->v6.sin6_addr.s6_addr32[3] ==
457 			    addr1->v4.sin_addr.s_addr)
458 				return 1;
459 		}
460 		if (addr2->sa.sa_family == AF_INET &&
461 		    addr1->sa.sa_family == AF_INET6 &&
462 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
463 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
464 			    addr1->v6.sin6_addr.s6_addr32[3] ==
465 			    addr2->v4.sin_addr.s_addr)
466 				return 1;
467 		}
468 		return 0;
469 	}
470 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
471 		return 0;
472 	/* If this is a linklocal address, compare the scope_id. */
473 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
474 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
475 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
476 			return 0;
477 		}
478 	}
479 
480 	return 1;
481 }
482 
483 /* Initialize addr struct to INADDR_ANY. */
484 static void sctp_v6_inaddr_any(union sctp_addr *addr, unsigned short port)
485 {
486 	memset(addr, 0x00, sizeof(union sctp_addr));
487 	addr->v6.sin6_family = AF_INET6;
488 	addr->v6.sin6_port = port;
489 }
490 
491 /* Is this a wildcard address? */
492 static int sctp_v6_is_any(const union sctp_addr *addr)
493 {
494 	return ipv6_addr_any(&addr->v6.sin6_addr);
495 }
496 
497 /* Should this be available for binding?   */
498 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
499 {
500 	int type;
501 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
502 
503 	type = ipv6_addr_type(in6);
504 	if (IPV6_ADDR_ANY == type)
505 		return 1;
506 	if (type == IPV6_ADDR_MAPPED) {
507 		if (sp && !sp->v4mapped)
508 			return 0;
509 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
510 			return 0;
511 		sctp_v6_map_v4(addr);
512 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
513 	}
514 	if (!(type & IPV6_ADDR_UNICAST))
515 		return 0;
516 
517 	return ipv6_chk_addr(in6, NULL, 0);
518 }
519 
520 /* This function checks if the address is a valid address to be used for
521  * SCTP.
522  *
523  * Output:
524  * Return 0 - If the address is a non-unicast or an illegal address.
525  * Return 1 - If the address is a unicast.
526  */
527 static int sctp_v6_addr_valid(union sctp_addr *addr,
528 			      struct sctp_sock *sp,
529 			      const struct sk_buff *skb)
530 {
531 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
532 
533 	/* Support v4-mapped-v6 address. */
534 	if (ret == IPV6_ADDR_MAPPED) {
535 		/* Note: This routine is used in input, so v4-mapped-v6
536 		 * are disallowed here when there is no sctp_sock.
537 		 */
538 		if (!sp || !sp->v4mapped)
539 			return 0;
540 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
541 			return 0;
542 		sctp_v6_map_v4(addr);
543 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
544 	}
545 
546 	/* Is this a non-unicast address */
547 	if (!(ret & IPV6_ADDR_UNICAST))
548 		return 0;
549 
550 	return 1;
551 }
552 
553 /* What is the scope of 'addr'?  */
554 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
555 {
556 	int v6scope;
557 	sctp_scope_t retval;
558 
559 	/* The IPv6 scope is really a set of bit fields.
560 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
561 	 */
562 
563 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
564 	switch (v6scope) {
565 	case IFA_HOST:
566 		retval = SCTP_SCOPE_LOOPBACK;
567 		break;
568 	case IFA_LINK:
569 		retval = SCTP_SCOPE_LINK;
570 		break;
571 	case IFA_SITE:
572 		retval = SCTP_SCOPE_PRIVATE;
573 		break;
574 	default:
575 		retval = SCTP_SCOPE_GLOBAL;
576 		break;
577 	};
578 
579 	return retval;
580 }
581 
582 /* Create and initialize a new sk for the socket to be returned by accept(). */
583 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
584 					     struct sctp_association *asoc)
585 {
586 	struct inet_sock *inet = inet_sk(sk);
587 	struct sock *newsk;
588 	struct inet_sock *newinet;
589 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
590 	struct sctp6_sock *newsctp6sk;
591 
592 	newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
593 	if (!newsk)
594 		goto out;
595 
596 	sock_init_data(NULL, newsk);
597 
598 	newsk->sk_type = SOCK_STREAM;
599 
600 	newsk->sk_prot = sk->sk_prot;
601 	newsk->sk_no_check = sk->sk_no_check;
602 	newsk->sk_reuse = sk->sk_reuse;
603 
604 	newsk->sk_destruct = inet_sock_destruct;
605 	newsk->sk_family = PF_INET6;
606 	newsk->sk_protocol = IPPROTO_SCTP;
607 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
608 	newsk->sk_shutdown = sk->sk_shutdown;
609 	sock_reset_flag(sk, SOCK_ZAPPED);
610 
611 	newsctp6sk = (struct sctp6_sock *)newsk;
612 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
613 
614 	newinet = inet_sk(newsk);
615 	newnp = inet6_sk(newsk);
616 
617 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
618 
619 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
620 	 * and getpeername().
621 	 */
622 	newinet->sport = inet->sport;
623 	newnp->saddr = np->saddr;
624 	newnp->rcv_saddr = np->rcv_saddr;
625 	newinet->dport = htons(asoc->peer.port);
626 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
627 
628 	/* Init the ipv4 part of the socket since we can have sockets
629 	 * using v6 API for ipv4.
630 	 */
631 	newinet->uc_ttl = -1;
632 	newinet->mc_loop = 1;
633 	newinet->mc_ttl = 1;
634 	newinet->mc_index = 0;
635 	newinet->mc_list = NULL;
636 
637 	if (ipv4_config.no_pmtu_disc)
638 		newinet->pmtudisc = IP_PMTUDISC_DONT;
639 	else
640 		newinet->pmtudisc = IP_PMTUDISC_WANT;
641 
642 	sk_refcnt_debug_inc(newsk);
643 
644 	if (newsk->sk_prot->init(newsk)) {
645 		sk_common_release(newsk);
646 		newsk = NULL;
647 	}
648 
649 out:
650 	return newsk;
651 }
652 
653 /* Map v4 address to mapped v6 address */
654 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
655 {
656 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
657 		sctp_v4_map_v6(addr);
658 }
659 
660 /* Where did this skb come from?  */
661 static int sctp_v6_skb_iif(const struct sk_buff *skb)
662 {
663 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
664 	return opt->iif;
665 }
666 
667 /* Was this packet marked by Explicit Congestion Notification? */
668 static int sctp_v6_is_ce(const struct sk_buff *skb)
669 {
670 	return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
671 }
672 
673 /* Dump the v6 addr to the seq file. */
674 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
675 {
676 	seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
677 }
678 
679 /* Initialize a PF_INET6 socket msg_name. */
680 static void sctp_inet6_msgname(char *msgname, int *addr_len)
681 {
682 	struct sockaddr_in6 *sin6;
683 
684 	sin6 = (struct sockaddr_in6 *)msgname;
685 	sin6->sin6_family = AF_INET6;
686 	sin6->sin6_flowinfo = 0;
687 	sin6->sin6_scope_id = 0; /*FIXME */
688 	*addr_len = sizeof(struct sockaddr_in6);
689 }
690 
691 /* Initialize a PF_INET msgname from a ulpevent. */
692 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
693 				     char *msgname, int *addrlen)
694 {
695 	struct sockaddr_in6 *sin6, *sin6from;
696 
697 	if (msgname) {
698 		union sctp_addr *addr;
699 		struct sctp_association *asoc;
700 
701 		asoc = event->asoc;
702 		sctp_inet6_msgname(msgname, addrlen);
703 		sin6 = (struct sockaddr_in6 *)msgname;
704 		sin6->sin6_port = htons(asoc->peer.port);
705 		addr = &asoc->peer.primary_addr;
706 
707 		/* Note: If we go to a common v6 format, this code
708 		 * will change.
709 		 */
710 
711 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
712 		if (sctp_sk(asoc->base.sk)->v4mapped &&
713 		    AF_INET == addr->sa.sa_family) {
714 			sctp_v4_map_v6((union sctp_addr *)sin6);
715 			sin6->sin6_addr.s6_addr32[3] =
716 				addr->v4.sin_addr.s_addr;
717 			return;
718 		}
719 
720 		sin6from = &asoc->peer.primary_addr.v6;
721 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
722 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
723 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
724 	}
725 }
726 
727 /* Initialize a msg_name from an inbound skb. */
728 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
729 				   int *addr_len)
730 {
731 	struct sctphdr *sh;
732 	struct sockaddr_in6 *sin6;
733 
734 	if (msgname) {
735 		sctp_inet6_msgname(msgname, addr_len);
736 		sin6 = (struct sockaddr_in6 *)msgname;
737 		sh = (struct sctphdr *)skb->h.raw;
738 		sin6->sin6_port = sh->source;
739 
740 		/* Map ipv4 address into v4-mapped-on-v6 address. */
741 		if (sctp_sk(skb->sk)->v4mapped &&
742 		    skb->nh.iph->version == 4) {
743 			sctp_v4_map_v6((union sctp_addr *)sin6);
744 			sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
745 			return;
746 		}
747 
748 		/* Otherwise, just copy the v6 address. */
749 		ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
750 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
751 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
752 			sin6->sin6_scope_id = ev->iif;
753 		}
754 	}
755 }
756 
757 /* Do we support this AF? */
758 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
759 {
760 	switch (family) {
761 	case AF_INET6:
762 		return 1;
763 	/* v4-mapped-v6 addresses */
764 	case AF_INET:
765 		if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
766 			return 1;
767 	default:
768 		return 0;
769 	}
770 }
771 
772 /* Address matching with wildcards allowed.  This extra level
773  * of indirection lets us choose whether a PF_INET6 should
774  * disallow any v4 addresses if we so choose.
775  */
776 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
777 			       const union sctp_addr *addr2,
778 			       struct sctp_sock *opt)
779 {
780 	struct sctp_af *af1, *af2;
781 
782 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
783 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
784 
785 	if (!af1 || !af2)
786 		return 0;
787 	/* Today, wildcard AF_INET/AF_INET6. */
788 	if (sctp_is_any(addr1) || sctp_is_any(addr2))
789 		return 1;
790 
791 	if (addr1->sa.sa_family != addr2->sa.sa_family)
792 		return 0;
793 
794 	return af1->cmp_addr(addr1, addr2);
795 }
796 
797 /* Verify that the provided sockaddr looks bindable.   Common verification,
798  * has already been taken care of.
799  */
800 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
801 {
802 	struct sctp_af *af;
803 
804 	/* ASSERT: address family has already been verified. */
805 	if (addr->sa.sa_family != AF_INET6)
806 		af = sctp_get_af_specific(addr->sa.sa_family);
807 	else {
808 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
809 		struct net_device *dev;
810 
811 		if (type & IPV6_ADDR_LINKLOCAL) {
812 			if (!addr->v6.sin6_scope_id)
813 				return 0;
814 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
815 			if (!dev)
816 				return 0;
817 			dev_put(dev);
818 		}
819 		af = opt->pf->af;
820 	}
821 	return af->available(addr, opt);
822 }
823 
824 /* Verify that the provided sockaddr looks sendable.   Common verification,
825  * has already been taken care of.
826  */
827 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
828 {
829 	struct sctp_af *af = NULL;
830 
831 	/* ASSERT: address family has already been verified. */
832 	if (addr->sa.sa_family != AF_INET6)
833 		af = sctp_get_af_specific(addr->sa.sa_family);
834 	else {
835 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
836 		struct net_device *dev;
837 
838 		if (type & IPV6_ADDR_LINKLOCAL) {
839 			if (!addr->v6.sin6_scope_id)
840 				return 0;
841 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
842 			if (!dev)
843 				return 0;
844 			dev_put(dev);
845 		}
846 		af = opt->pf->af;
847 	}
848 
849 	return af != NULL;
850 }
851 
852 /* Fill in Supported Address Type information for INIT and INIT-ACK
853  * chunks.   Note: In the future, we may want to look at sock options
854  * to determine whether a PF_INET6 socket really wants to have IPV4
855  * addresses.
856  * Returns number of addresses supported.
857  */
858 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
859 				      __u16 *types)
860 {
861 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
862 	types[1] = SCTP_PARAM_IPV6_ADDRESS;
863 	return 2;
864 }
865 
866 static const struct proto_ops inet6_seqpacket_ops = {
867 	.family		   = PF_INET6,
868 	.owner		   = THIS_MODULE,
869 	.release	   = inet6_release,
870 	.bind		   = inet6_bind,
871 	.connect	   = inet_dgram_connect,
872 	.socketpair	   = sock_no_socketpair,
873 	.accept		   = inet_accept,
874 	.getname	   = inet6_getname,
875 	.poll		   = sctp_poll,
876 	.ioctl		   = inet6_ioctl,
877 	.listen		   = sctp_inet_listen,
878 	.shutdown	   = inet_shutdown,
879 	.setsockopt	   = sock_common_setsockopt,
880 	.getsockopt	   = sock_common_getsockopt,
881 	.sendmsg	   = inet_sendmsg,
882 	.recvmsg	   = sock_common_recvmsg,
883 	.mmap		   = sock_no_mmap,
884 #ifdef CONFIG_COMPAT
885 	.compat_setsockopt = compat_sock_common_setsockopt,
886 	.compat_getsockopt = compat_sock_common_getsockopt,
887 #endif
888 };
889 
890 static struct inet_protosw sctpv6_seqpacket_protosw = {
891 	.type          = SOCK_SEQPACKET,
892 	.protocol      = IPPROTO_SCTP,
893 	.prot 	       = &sctpv6_prot,
894 	.ops           = &inet6_seqpacket_ops,
895 	.capability    = -1,
896 	.no_check      = 0,
897 	.flags         = SCTP_PROTOSW_FLAG
898 };
899 static struct inet_protosw sctpv6_stream_protosw = {
900 	.type          = SOCK_STREAM,
901 	.protocol      = IPPROTO_SCTP,
902 	.prot 	       = &sctpv6_prot,
903 	.ops           = &inet6_seqpacket_ops,
904 	.capability    = -1,
905 	.no_check      = 0,
906 	.flags         = SCTP_PROTOSW_FLAG,
907 };
908 
909 static int sctp6_rcv(struct sk_buff **pskb)
910 {
911 	return sctp_rcv(*pskb) ? -1 : 0;
912 }
913 
914 static struct inet6_protocol sctpv6_protocol = {
915 	.handler      = sctp6_rcv,
916 	.err_handler  = sctp_v6_err,
917 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
918 };
919 
920 static struct sctp_af sctp_ipv6_specific = {
921 	.sa_family	   = AF_INET6,
922 	.sctp_xmit	   = sctp_v6_xmit,
923 	.setsockopt	   = ipv6_setsockopt,
924 	.getsockopt	   = ipv6_getsockopt,
925 	.get_dst	   = sctp_v6_get_dst,
926 	.get_saddr	   = sctp_v6_get_saddr,
927 	.copy_addrlist	   = sctp_v6_copy_addrlist,
928 	.from_skb	   = sctp_v6_from_skb,
929 	.from_sk	   = sctp_v6_from_sk,
930 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
931 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
932 	.from_addr_param   = sctp_v6_from_addr_param,
933 	.to_addr_param	   = sctp_v6_to_addr_param,
934 	.dst_saddr	   = sctp_v6_dst_saddr,
935 	.cmp_addr	   = sctp_v6_cmp_addr,
936 	.scope		   = sctp_v6_scope,
937 	.addr_valid	   = sctp_v6_addr_valid,
938 	.inaddr_any	   = sctp_v6_inaddr_any,
939 	.is_any		   = sctp_v6_is_any,
940 	.available	   = sctp_v6_available,
941 	.skb_iif	   = sctp_v6_skb_iif,
942 	.is_ce		   = sctp_v6_is_ce,
943 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
944 	.net_header_len	   = sizeof(struct ipv6hdr),
945 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
946 #ifdef CONFIG_COMPAT
947 	.compat_setsockopt = compat_ipv6_setsockopt,
948 	.compat_getsockopt = compat_ipv6_getsockopt,
949 #endif
950 };
951 
952 static struct sctp_pf sctp_pf_inet6_specific = {
953 	.event_msgname = sctp_inet6_event_msgname,
954 	.skb_msgname   = sctp_inet6_skb_msgname,
955 	.af_supported  = sctp_inet6_af_supported,
956 	.cmp_addr      = sctp_inet6_cmp_addr,
957 	.bind_verify   = sctp_inet6_bind_verify,
958 	.send_verify   = sctp_inet6_send_verify,
959 	.supported_addrs = sctp_inet6_supported_addrs,
960 	.create_accept_sk = sctp_v6_create_accept_sk,
961 	.addr_v4map    = sctp_v6_addr_v4map,
962 	.af            = &sctp_ipv6_specific,
963 };
964 
965 /* Initialize IPv6 support and register with inet6 stack.  */
966 int sctp_v6_init(void)
967 {
968 	int rc = proto_register(&sctpv6_prot, 1);
969 
970 	if (rc)
971 		goto out;
972 	/* Register inet6 protocol. */
973 	rc = -EAGAIN;
974 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
975 		goto out_unregister_sctp_proto;
976 
977 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
978 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
979 	inet6_register_protosw(&sctpv6_stream_protosw);
980 
981 	/* Register the SCTP specific PF_INET6 functions. */
982 	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
983 
984 	/* Register the SCTP specific AF_INET6 functions. */
985 	sctp_register_af(&sctp_ipv6_specific);
986 
987 	/* Register notifier for inet6 address additions/deletions. */
988 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
989 	rc = 0;
990 out:
991 	return rc;
992 out_unregister_sctp_proto:
993 	proto_unregister(&sctpv6_prot);
994 	goto out;
995 }
996 
997 /* IPv6 specific exit support. */
998 void sctp_v6_exit(void)
999 {
1000 	list_del(&sctp_ipv6_specific.list);
1001 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1002 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1003 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1004 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1005 	proto_unregister(&sctpv6_prot);
1006 }
1007