xref: /linux/net/sctp/ipv6.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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->a.sa.sa_family == AF_INET6) &&
294 		    (scope <= sctp_scope(&laddr->a))) {
295 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
296 			if (!baddr || (matchlen < bmatchlen)) {
297 				baddr = &laddr->a;
298 				matchlen = bmatchlen;
299 			}
300 		}
301 	}
302 
303 	if (baddr) {
304 		memcpy(saddr, baddr, sizeof(union sctp_addr));
305 		SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
306 				  NIP6(saddr->v6.sin6_addr));
307 	} else {
308 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
309 		       "address for the dest:" NIP6_FMT "\n",
310 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
311 	}
312 
313 	sctp_read_unlock(addr_lock);
314 }
315 
316 /* Make a copy of all potential local addresses. */
317 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
318 				  struct net_device *dev)
319 {
320 	struct inet6_dev *in6_dev;
321 	struct inet6_ifaddr *ifp;
322 	struct sctp_sockaddr_entry *addr;
323 
324 	read_lock(&addrconf_lock);
325 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
326 		read_unlock(&addrconf_lock);
327 		return;
328 	}
329 
330 	read_lock(&in6_dev->lock);
331 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
332 		/* Add the address to the local list.  */
333 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
334 		if (addr) {
335 			addr->a.v6.sin6_family = AF_INET6;
336 			addr->a.v6.sin6_port = 0;
337 			addr->a.v6.sin6_addr = ifp->addr;
338 			addr->a.v6.sin6_scope_id = dev->ifindex;
339 			INIT_LIST_HEAD(&addr->list);
340 			list_add_tail(&addr->list, addrlist);
341 		}
342 	}
343 
344 	read_unlock(&in6_dev->lock);
345 	read_unlock(&addrconf_lock);
346 }
347 
348 /* Initialize a sockaddr_storage from in incoming skb. */
349 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
350 			     int is_saddr)
351 {
352 	void *from;
353 	__u16 *port;
354 	struct sctphdr *sh;
355 
356 	port = &addr->v6.sin6_port;
357 	addr->v6.sin6_family = AF_INET6;
358 	addr->v6.sin6_flowinfo = 0; /* FIXME */
359 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
360 
361 	sh = (struct sctphdr *) skb->h.raw;
362 	if (is_saddr) {
363 		*port  = ntohs(sh->source);
364 		from = &skb->nh.ipv6h->saddr;
365 	} else {
366 		*port = ntohs(sh->dest);
367 		from = &skb->nh.ipv6h->daddr;
368 	}
369 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
370 }
371 
372 /* Initialize an sctp_addr from a socket. */
373 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
374 {
375 	addr->v6.sin6_family = AF_INET6;
376 	addr->v6.sin6_port = inet_sk(sk)->num;
377 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
378 }
379 
380 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
381 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
382 {
383 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
384 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
385 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
386 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
387 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
388 			addr->v4.sin_addr.s_addr;
389 	} else {
390 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
391 	}
392 }
393 
394 /* Initialize sk->sk_daddr from sctp_addr. */
395 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
396 {
397 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
398 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
399 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
400 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
401 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
402 	} else {
403 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
404 	}
405 }
406 
407 /* Initialize a sctp_addr from an address parameter. */
408 static void sctp_v6_from_addr_param(union sctp_addr *addr,
409 				    union sctp_addr_param *param,
410 				    __u16 port, int iif)
411 {
412 	addr->v6.sin6_family = AF_INET6;
413 	addr->v6.sin6_port = port;
414 	addr->v6.sin6_flowinfo = 0; /* BUG */
415 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
416 	addr->v6.sin6_scope_id = iif;
417 }
418 
419 /* Initialize an address parameter from a sctp_addr and return the length
420  * of the address parameter.
421  */
422 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
423 				 union sctp_addr_param *param)
424 {
425 	int length = sizeof(sctp_ipv6addr_param_t);
426 
427 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
428 	param->v6.param_hdr.length = ntohs(length);
429 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
430 
431 	return length;
432 }
433 
434 /* Initialize a sctp_addr from a dst_entry. */
435 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
436 			      unsigned short port)
437 {
438 	struct rt6_info *rt = (struct rt6_info *)dst;
439 	addr->sa.sa_family = AF_INET6;
440 	addr->v6.sin6_port = port;
441 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
442 }
443 
444 /* Compare addresses exactly.
445  * v4-mapped-v6 is also in consideration.
446  */
447 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
448 			    const union sctp_addr *addr2)
449 {
450 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
451 		if (addr1->sa.sa_family == AF_INET &&
452 		    addr2->sa.sa_family == AF_INET6 &&
453 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
454 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
455 			    addr2->v6.sin6_addr.s6_addr32[3] ==
456 			    addr1->v4.sin_addr.s_addr)
457 				return 1;
458 		}
459 		if (addr2->sa.sa_family == AF_INET &&
460 		    addr1->sa.sa_family == AF_INET6 &&
461 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
462 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
463 			    addr1->v6.sin6_addr.s6_addr32[3] ==
464 			    addr2->v4.sin_addr.s_addr)
465 				return 1;
466 		}
467 		return 0;
468 	}
469 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
470 		return 0;
471 	/* If this is a linklocal address, compare the scope_id. */
472 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
473 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
474 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
475 			return 0;
476 		}
477 	}
478 
479 	return 1;
480 }
481 
482 /* Initialize addr struct to INADDR_ANY. */
483 static void sctp_v6_inaddr_any(union sctp_addr *addr, unsigned short port)
484 {
485 	memset(addr, 0x00, sizeof(union sctp_addr));
486 	addr->v6.sin6_family = AF_INET6;
487 	addr->v6.sin6_port = port;
488 }
489 
490 /* Is this a wildcard address? */
491 static int sctp_v6_is_any(const union sctp_addr *addr)
492 {
493 	return ipv6_addr_any(&addr->v6.sin6_addr);
494 }
495 
496 /* Should this be available for binding?   */
497 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
498 {
499 	int type;
500 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
501 
502 	type = ipv6_addr_type(in6);
503 	if (IPV6_ADDR_ANY == type)
504 		return 1;
505 	if (type == IPV6_ADDR_MAPPED) {
506 		if (sp && !sp->v4mapped)
507 			return 0;
508 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
509 			return 0;
510 		sctp_v6_map_v4(addr);
511 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
512 	}
513 	if (!(type & IPV6_ADDR_UNICAST))
514 		return 0;
515 
516 	return ipv6_chk_addr(in6, NULL, 0);
517 }
518 
519 /* This function checks if the address is a valid address to be used for
520  * SCTP.
521  *
522  * Output:
523  * Return 0 - If the address is a non-unicast or an illegal address.
524  * Return 1 - If the address is a unicast.
525  */
526 static int sctp_v6_addr_valid(union sctp_addr *addr, struct sctp_sock *sp)
527 {
528 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
529 
530 	/* Support v4-mapped-v6 address. */
531 	if (ret == IPV6_ADDR_MAPPED) {
532 		/* Note: This routine is used in input, so v4-mapped-v6
533 		 * are disallowed here when there is no sctp_sock.
534 		 */
535 		if (!sp || !sp->v4mapped)
536 			return 0;
537 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
538 			return 0;
539 		sctp_v6_map_v4(addr);
540 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp);
541 	}
542 
543 	/* Is this a non-unicast address */
544 	if (!(ret & IPV6_ADDR_UNICAST))
545 		return 0;
546 
547 	return 1;
548 }
549 
550 /* What is the scope of 'addr'?  */
551 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
552 {
553 	int v6scope;
554 	sctp_scope_t retval;
555 
556 	/* The IPv6 scope is really a set of bit fields.
557 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
558 	 */
559 
560 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
561 	switch (v6scope) {
562 	case IFA_HOST:
563 		retval = SCTP_SCOPE_LOOPBACK;
564 		break;
565 	case IFA_LINK:
566 		retval = SCTP_SCOPE_LINK;
567 		break;
568 	case IFA_SITE:
569 		retval = SCTP_SCOPE_PRIVATE;
570 		break;
571 	default:
572 		retval = SCTP_SCOPE_GLOBAL;
573 		break;
574 	};
575 
576 	return retval;
577 }
578 
579 /* Create and initialize a new sk for the socket to be returned by accept(). */
580 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
581 					     struct sctp_association *asoc)
582 {
583 	struct inet_sock *inet = inet_sk(sk);
584 	struct sock *newsk;
585 	struct inet_sock *newinet;
586 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
587 	struct sctp6_sock *newsctp6sk;
588 
589 	newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
590 	if (!newsk)
591 		goto out;
592 
593 	sock_init_data(NULL, newsk);
594 
595 	newsk->sk_type = SOCK_STREAM;
596 
597 	newsk->sk_prot = sk->sk_prot;
598 	newsk->sk_no_check = sk->sk_no_check;
599 	newsk->sk_reuse = sk->sk_reuse;
600 
601 	newsk->sk_destruct = inet_sock_destruct;
602 	newsk->sk_family = PF_INET6;
603 	newsk->sk_protocol = IPPROTO_SCTP;
604 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
605 	newsk->sk_shutdown = sk->sk_shutdown;
606 	sock_reset_flag(sk, SOCK_ZAPPED);
607 
608 	newsctp6sk = (struct sctp6_sock *)newsk;
609 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
610 
611 	newinet = inet_sk(newsk);
612 	newnp = inet6_sk(newsk);
613 
614 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
615 
616 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
617 	 * and getpeername().
618 	 */
619 	newinet->sport = inet->sport;
620 	newnp->saddr = np->saddr;
621 	newnp->rcv_saddr = np->rcv_saddr;
622 	newinet->dport = htons(asoc->peer.port);
623 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
624 
625 	/* Init the ipv4 part of the socket since we can have sockets
626 	 * using v6 API for ipv4.
627 	 */
628 	newinet->uc_ttl = -1;
629 	newinet->mc_loop = 1;
630 	newinet->mc_ttl = 1;
631 	newinet->mc_index = 0;
632 	newinet->mc_list = NULL;
633 
634 	if (ipv4_config.no_pmtu_disc)
635 		newinet->pmtudisc = IP_PMTUDISC_DONT;
636 	else
637 		newinet->pmtudisc = IP_PMTUDISC_WANT;
638 
639 	sk_refcnt_debug_inc(newsk);
640 
641 	if (newsk->sk_prot->init(newsk)) {
642 		sk_common_release(newsk);
643 		newsk = NULL;
644 	}
645 
646 out:
647 	return newsk;
648 }
649 
650 /* Map v4 address to mapped v6 address */
651 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
652 {
653 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
654 		sctp_v4_map_v6(addr);
655 }
656 
657 /* Where did this skb come from?  */
658 static int sctp_v6_skb_iif(const struct sk_buff *skb)
659 {
660 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
661 	return opt->iif;
662 }
663 
664 /* Was this packet marked by Explicit Congestion Notification? */
665 static int sctp_v6_is_ce(const struct sk_buff *skb)
666 {
667 	return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
668 }
669 
670 /* Dump the v6 addr to the seq file. */
671 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
672 {
673 	seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
674 }
675 
676 /* Initialize a PF_INET6 socket msg_name. */
677 static void sctp_inet6_msgname(char *msgname, int *addr_len)
678 {
679 	struct sockaddr_in6 *sin6;
680 
681 	sin6 = (struct sockaddr_in6 *)msgname;
682 	sin6->sin6_family = AF_INET6;
683 	sin6->sin6_flowinfo = 0;
684 	sin6->sin6_scope_id = 0; /*FIXME */
685 	*addr_len = sizeof(struct sockaddr_in6);
686 }
687 
688 /* Initialize a PF_INET msgname from a ulpevent. */
689 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
690 				     char *msgname, int *addrlen)
691 {
692 	struct sockaddr_in6 *sin6, *sin6from;
693 
694 	if (msgname) {
695 		union sctp_addr *addr;
696 		struct sctp_association *asoc;
697 
698 		asoc = event->asoc;
699 		sctp_inet6_msgname(msgname, addrlen);
700 		sin6 = (struct sockaddr_in6 *)msgname;
701 		sin6->sin6_port = htons(asoc->peer.port);
702 		addr = &asoc->peer.primary_addr;
703 
704 		/* Note: If we go to a common v6 format, this code
705 		 * will change.
706 		 */
707 
708 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
709 		if (sctp_sk(asoc->base.sk)->v4mapped &&
710 		    AF_INET == addr->sa.sa_family) {
711 			sctp_v4_map_v6((union sctp_addr *)sin6);
712 			sin6->sin6_addr.s6_addr32[3] =
713 				addr->v4.sin_addr.s_addr;
714 			return;
715 		}
716 
717 		sin6from = &asoc->peer.primary_addr.v6;
718 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
719 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
720 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
721 	}
722 }
723 
724 /* Initialize a msg_name from an inbound skb. */
725 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
726 				   int *addr_len)
727 {
728 	struct sctphdr *sh;
729 	struct sockaddr_in6 *sin6;
730 
731 	if (msgname) {
732 		sctp_inet6_msgname(msgname, addr_len);
733 		sin6 = (struct sockaddr_in6 *)msgname;
734 		sh = (struct sctphdr *)skb->h.raw;
735 		sin6->sin6_port = sh->source;
736 
737 		/* Map ipv4 address into v4-mapped-on-v6 address. */
738 		if (sctp_sk(skb->sk)->v4mapped &&
739 		    skb->nh.iph->version == 4) {
740 			sctp_v4_map_v6((union sctp_addr *)sin6);
741 			sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
742 			return;
743 		}
744 
745 		/* Otherwise, just copy the v6 address. */
746 		ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
747 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
748 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
749 			sin6->sin6_scope_id = ev->iif;
750 		}
751 	}
752 }
753 
754 /* Do we support this AF? */
755 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
756 {
757 	switch (family) {
758 	case AF_INET6:
759 		return 1;
760 	/* v4-mapped-v6 addresses */
761 	case AF_INET:
762 		if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
763 			return 1;
764 	default:
765 		return 0;
766 	}
767 }
768 
769 /* Address matching with wildcards allowed.  This extra level
770  * of indirection lets us choose whether a PF_INET6 should
771  * disallow any v4 addresses if we so choose.
772  */
773 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
774 			       const union sctp_addr *addr2,
775 			       struct sctp_sock *opt)
776 {
777 	struct sctp_af *af1, *af2;
778 
779 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
780 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
781 
782 	if (!af1 || !af2)
783 		return 0;
784 	/* Today, wildcard AF_INET/AF_INET6. */
785 	if (sctp_is_any(addr1) || sctp_is_any(addr2))
786 		return 1;
787 
788 	if (addr1->sa.sa_family != addr2->sa.sa_family)
789 		return 0;
790 
791 	return af1->cmp_addr(addr1, addr2);
792 }
793 
794 /* Verify that the provided sockaddr looks bindable.   Common verification,
795  * has already been taken care of.
796  */
797 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
798 {
799 	struct sctp_af *af;
800 
801 	/* ASSERT: address family has already been verified. */
802 	if (addr->sa.sa_family != AF_INET6)
803 		af = sctp_get_af_specific(addr->sa.sa_family);
804 	else {
805 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
806 		struct net_device *dev;
807 
808 		if (type & IPV6_ADDR_LINKLOCAL) {
809 			if (!addr->v6.sin6_scope_id)
810 				return 0;
811 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
812 			if (!dev)
813 				return 0;
814 			dev_put(dev);
815 		}
816 		af = opt->pf->af;
817 	}
818 	return af->available(addr, opt);
819 }
820 
821 /* Verify that the provided sockaddr looks sendable.   Common verification,
822  * has already been taken care of.
823  */
824 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
825 {
826 	struct sctp_af *af = NULL;
827 
828 	/* ASSERT: address family has already been verified. */
829 	if (addr->sa.sa_family != AF_INET6)
830 		af = sctp_get_af_specific(addr->sa.sa_family);
831 	else {
832 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
833 		struct net_device *dev;
834 
835 		if (type & IPV6_ADDR_LINKLOCAL) {
836 			if (!addr->v6.sin6_scope_id)
837 				return 0;
838 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
839 			if (!dev)
840 				return 0;
841 			dev_put(dev);
842 		}
843 		af = opt->pf->af;
844 	}
845 
846 	return af != NULL;
847 }
848 
849 /* Fill in Supported Address Type information for INIT and INIT-ACK
850  * chunks.   Note: In the future, we may want to look at sock options
851  * to determine whether a PF_INET6 socket really wants to have IPV4
852  * addresses.
853  * Returns number of addresses supported.
854  */
855 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
856 				      __u16 *types)
857 {
858 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
859 	types[1] = SCTP_PARAM_IPV6_ADDRESS;
860 	return 2;
861 }
862 
863 static const struct proto_ops inet6_seqpacket_ops = {
864 	.family		   = PF_INET6,
865 	.owner		   = THIS_MODULE,
866 	.release	   = inet6_release,
867 	.bind		   = inet6_bind,
868 	.connect	   = inet_dgram_connect,
869 	.socketpair	   = sock_no_socketpair,
870 	.accept		   = inet_accept,
871 	.getname	   = inet6_getname,
872 	.poll		   = sctp_poll,
873 	.ioctl		   = inet6_ioctl,
874 	.listen		   = sctp_inet_listen,
875 	.shutdown	   = inet_shutdown,
876 	.setsockopt	   = sock_common_setsockopt,
877 	.getsockopt	   = sock_common_getsockopt,
878 	.sendmsg	   = inet_sendmsg,
879 	.recvmsg	   = sock_common_recvmsg,
880 	.mmap		   = sock_no_mmap,
881 #ifdef CONFIG_COMPAT
882 	.compat_setsockopt = compat_sock_common_setsockopt,
883 	.compat_getsockopt = compat_sock_common_getsockopt,
884 #endif
885 };
886 
887 static struct inet_protosw sctpv6_seqpacket_protosw = {
888 	.type          = SOCK_SEQPACKET,
889 	.protocol      = IPPROTO_SCTP,
890 	.prot 	       = &sctpv6_prot,
891 	.ops           = &inet6_seqpacket_ops,
892 	.capability    = -1,
893 	.no_check      = 0,
894 	.flags         = SCTP_PROTOSW_FLAG
895 };
896 static struct inet_protosw sctpv6_stream_protosw = {
897 	.type          = SOCK_STREAM,
898 	.protocol      = IPPROTO_SCTP,
899 	.prot 	       = &sctpv6_prot,
900 	.ops           = &inet6_seqpacket_ops,
901 	.capability    = -1,
902 	.no_check      = 0,
903 	.flags         = SCTP_PROTOSW_FLAG,
904 };
905 
906 static int sctp6_rcv(struct sk_buff **pskb)
907 {
908 	return sctp_rcv(*pskb) ? -1 : 0;
909 }
910 
911 static struct inet6_protocol sctpv6_protocol = {
912 	.handler      = sctp6_rcv,
913 	.err_handler  = sctp_v6_err,
914 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
915 };
916 
917 static struct sctp_af sctp_ipv6_specific = {
918 	.sa_family	   = AF_INET6,
919 	.sctp_xmit	   = sctp_v6_xmit,
920 	.setsockopt	   = ipv6_setsockopt,
921 	.getsockopt	   = ipv6_getsockopt,
922 	.get_dst	   = sctp_v6_get_dst,
923 	.get_saddr	   = sctp_v6_get_saddr,
924 	.copy_addrlist	   = sctp_v6_copy_addrlist,
925 	.from_skb	   = sctp_v6_from_skb,
926 	.from_sk	   = sctp_v6_from_sk,
927 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
928 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
929 	.from_addr_param   = sctp_v6_from_addr_param,
930 	.to_addr_param	   = sctp_v6_to_addr_param,
931 	.dst_saddr	   = sctp_v6_dst_saddr,
932 	.cmp_addr	   = sctp_v6_cmp_addr,
933 	.scope		   = sctp_v6_scope,
934 	.addr_valid	   = sctp_v6_addr_valid,
935 	.inaddr_any	   = sctp_v6_inaddr_any,
936 	.is_any		   = sctp_v6_is_any,
937 	.available	   = sctp_v6_available,
938 	.skb_iif	   = sctp_v6_skb_iif,
939 	.is_ce		   = sctp_v6_is_ce,
940 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
941 	.net_header_len	   = sizeof(struct ipv6hdr),
942 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
943 #ifdef CONFIG_COMPAT
944 	.compat_setsockopt = compat_ipv6_setsockopt,
945 	.compat_getsockopt = compat_ipv6_getsockopt,
946 #endif
947 };
948 
949 static struct sctp_pf sctp_pf_inet6_specific = {
950 	.event_msgname = sctp_inet6_event_msgname,
951 	.skb_msgname   = sctp_inet6_skb_msgname,
952 	.af_supported  = sctp_inet6_af_supported,
953 	.cmp_addr      = sctp_inet6_cmp_addr,
954 	.bind_verify   = sctp_inet6_bind_verify,
955 	.send_verify   = sctp_inet6_send_verify,
956 	.supported_addrs = sctp_inet6_supported_addrs,
957 	.create_accept_sk = sctp_v6_create_accept_sk,
958 	.addr_v4map    = sctp_v6_addr_v4map,
959 	.af            = &sctp_ipv6_specific,
960 };
961 
962 /* Initialize IPv6 support and register with inet6 stack.  */
963 int sctp_v6_init(void)
964 {
965 	int rc = proto_register(&sctpv6_prot, 1);
966 
967 	if (rc)
968 		goto out;
969 	/* Register inet6 protocol. */
970 	rc = -EAGAIN;
971 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
972 		goto out_unregister_sctp_proto;
973 
974 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
975 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
976 	inet6_register_protosw(&sctpv6_stream_protosw);
977 
978 	/* Register the SCTP specific PF_INET6 functions. */
979 	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
980 
981 	/* Register the SCTP specific AF_INET6 functions. */
982 	sctp_register_af(&sctp_ipv6_specific);
983 
984 	/* Register notifier for inet6 address additions/deletions. */
985 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
986 	rc = 0;
987 out:
988 	return rc;
989 out_unregister_sctp_proto:
990 	proto_unregister(&sctpv6_prot);
991 	goto out;
992 }
993 
994 /* IPv6 specific exit support. */
995 void sctp_v6_exit(void)
996 {
997 	list_del(&sctp_ipv6_specific.list);
998 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
999 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1000 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1001 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1002 	proto_unregister(&sctpv6_prot);
1003 }
1004