xref: /openbmc/linux/net/sctp/ipv6.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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/in.h>
57 #include <linux/in6.h>
58 #include <linux/netdevice.h>
59 #include <linux/init.h>
60 #include <linux/ipsec.h>
61 
62 #include <linux/ipv6.h>
63 #include <linux/icmpv6.h>
64 #include <linux/random.h>
65 #include <linux/seq_file.h>
66 
67 #include <net/protocol.h>
68 #include <net/ndisc.h>
69 #include <net/ip.h>
70 #include <net/ipv6.h>
71 #include <net/transp_v6.h>
72 #include <net/addrconf.h>
73 #include <net/ip6_route.h>
74 #include <net/inet_common.h>
75 #include <net/inet_ecn.h>
76 #include <net/sctp/sctp.h>
77 
78 #include <asm/uaccess.h>
79 
80 /* Event handler for inet6 address addition/deletion events.  */
81 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
82 				void *ptr)
83 {
84 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
85 	struct sctp_sockaddr_entry *addr;
86 	struct list_head *pos, *temp;
87 
88 	switch (ev) {
89 	case NETDEV_UP:
90 		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
91 		if (addr) {
92 			addr->a.v6.sin6_family = AF_INET6;
93 			addr->a.v6.sin6_port = 0;
94 			memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
95 				 sizeof(struct in6_addr));
96 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
97 			list_add_tail(&addr->list, &sctp_local_addr_list);
98 		}
99 		break;
100 	case NETDEV_DOWN:
101 		list_for_each_safe(pos, temp, &sctp_local_addr_list) {
102 			addr = list_entry(pos, struct sctp_sockaddr_entry, list);
103 			if (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {
104 				list_del(pos);
105 				kfree(addr);
106 				break;
107 			}
108 		}
109 
110 		break;
111 	}
112 
113 	return NOTIFY_DONE;
114 }
115 
116 static struct notifier_block sctp_inet6addr_notifier = {
117 	.notifier_call = sctp_inet6addr_event,
118 };
119 
120 /* ICMP error handler. */
121 SCTP_STATIC void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
122 			     int type, int code, int offset, __be32 info)
123 {
124 	struct inet6_dev *idev;
125 	struct sock *sk;
126 	struct sctp_association *asoc;
127 	struct sctp_transport *transport;
128 	struct ipv6_pinfo *np;
129 	sk_buff_data_t saveip, savesctp;
130 	int err;
131 
132 	idev = in6_dev_get(skb->dev);
133 
134 	/* Fix up skb to look at the embedded net header. */
135 	saveip	 = skb->network_header;
136 	savesctp = skb->transport_header;
137 	skb_reset_network_header(skb);
138 	skb_set_transport_header(skb, offset);
139 	sk = sctp_err_lookup(AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
140 	/* Put back, the original pointers. */
141 	skb->network_header   = saveip;
142 	skb->transport_header = savesctp;
143 	if (!sk) {
144 		ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
145 		goto out;
146 	}
147 
148 	/* Warning:  The sock lock is held.  Remember to call
149 	 * sctp_err_finish!
150 	 */
151 
152 	switch (type) {
153 	case ICMPV6_PKT_TOOBIG:
154 		sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
155 		goto out_unlock;
156 	case ICMPV6_PARAMPROB:
157 		if (ICMPV6_UNK_NEXTHDR == code) {
158 			sctp_icmp_proto_unreachable(sk, asoc, transport);
159 			goto out_unlock;
160 		}
161 		break;
162 	default:
163 		break;
164 	}
165 
166 	np = inet6_sk(sk);
167 	icmpv6_err_convert(type, code, &err);
168 	if (!sock_owned_by_user(sk) && np->recverr) {
169 		sk->sk_err = err;
170 		sk->sk_error_report(sk);
171 	} else {  /* Only an error on timeout */
172 		sk->sk_err_soft = err;
173 	}
174 
175 out_unlock:
176 	sctp_err_finish(sk, asoc);
177 out:
178 	if (likely(idev != NULL))
179 		in6_dev_put(idev);
180 }
181 
182 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
183 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
184 			int ipfragok)
185 {
186 	struct sock *sk = skb->sk;
187 	struct ipv6_pinfo *np = inet6_sk(sk);
188 	struct flowi fl;
189 
190 	memset(&fl, 0, sizeof(fl));
191 
192 	fl.proto = sk->sk_protocol;
193 
194 	/* Fill in the dest address from the route entry passed with the skb
195 	 * and the source address from the transport.
196 	 */
197 	ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
198 	ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
199 
200 	fl.fl6_flowlabel = np->flow_label;
201 	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
202 	if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
203 		fl.oif = transport->saddr.v6.sin6_scope_id;
204 	else
205 		fl.oif = sk->sk_bound_dev_if;
206 
207 	if (np->opt && np->opt->srcrt) {
208 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
209 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
210 	}
211 
212 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
213 			  "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
214 			  __FUNCTION__, skb, skb->len,
215 			  NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
216 
217 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
218 
219 	return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
220 }
221 
222 /* Returns the dst cache entry for the given source and destination ip
223  * addresses.
224  */
225 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
226 					 union sctp_addr *daddr,
227 					 union sctp_addr *saddr)
228 {
229 	struct dst_entry *dst;
230 	struct flowi fl;
231 
232 	memset(&fl, 0, sizeof(fl));
233 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
234 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
235 		fl.oif = daddr->v6.sin6_scope_id;
236 
237 
238 	SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
239 			  __FUNCTION__, NIP6(fl.fl6_dst));
240 
241 	if (saddr) {
242 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
243 		SCTP_DEBUG_PRINTK(
244 			"SRC=" NIP6_FMT " - ",
245 			NIP6(fl.fl6_src));
246 	}
247 
248 	dst = ip6_route_output(NULL, &fl);
249 	if (!dst->error) {
250 		struct rt6_info *rt;
251 		rt = (struct rt6_info *)dst;
252 		SCTP_DEBUG_PRINTK(
253 			"rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
254 			NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
255 		return dst;
256 	}
257 	SCTP_DEBUG_PRINTK("NO ROUTE\n");
258 	dst_release(dst);
259 	return NULL;
260 }
261 
262 /* Returns the number of consecutive initial bits that match in the 2 ipv6
263  * addresses.
264  */
265 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
266 					 union sctp_addr *s2)
267 {
268 	struct in6_addr *a1 = &s1->v6.sin6_addr;
269 	struct in6_addr *a2 = &s2->v6.sin6_addr;
270 	int i, j;
271 
272 	for (i = 0; i < 4 ; i++) {
273 		__be32 a1xora2;
274 
275 		a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
276 
277 		if ((j = fls(ntohl(a1xora2))))
278 			return (i * 32 + 32 - j);
279 	}
280 
281 	return (i*32);
282 }
283 
284 /* Fills in the source address(saddr) based on the destination address(daddr)
285  * and asoc's bind address list.
286  */
287 static void sctp_v6_get_saddr(struct sctp_association *asoc,
288 			      struct dst_entry *dst,
289 			      union sctp_addr *daddr,
290 			      union sctp_addr *saddr)
291 {
292 	struct sctp_bind_addr *bp;
293 	rwlock_t *addr_lock;
294 	struct sctp_sockaddr_entry *laddr;
295 	struct list_head *pos;
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 "
302 			  "daddr:" NIP6_FMT " ",
303 			  __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
304 
305 	if (!asoc) {
306 		ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
307 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
308 				  NIP6(saddr->v6.sin6_addr));
309 		return;
310 	}
311 
312 	scope = sctp_scope(daddr);
313 
314 	bp = &asoc->base.bind_addr;
315 	addr_lock = &asoc->base.addr_lock;
316 
317 	/* Go through the bind address list and find the best source address
318 	 * that matches the scope of the destination address.
319 	 */
320 	sctp_read_lock(addr_lock);
321 	list_for_each(pos, &bp->address_list) {
322 		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
323 		if ((laddr->use_as_src) &&
324 		    (laddr->a.sa.sa_family == AF_INET6) &&
325 		    (scope <= sctp_scope(&laddr->a))) {
326 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
327 			if (!baddr || (matchlen < bmatchlen)) {
328 				baddr = &laddr->a;
329 				matchlen = bmatchlen;
330 			}
331 		}
332 	}
333 
334 	if (baddr) {
335 		memcpy(saddr, baddr, sizeof(union sctp_addr));
336 		SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
337 				  NIP6(saddr->v6.sin6_addr));
338 	} else {
339 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
340 		       "address for the dest:" NIP6_FMT "\n",
341 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
342 	}
343 
344 	sctp_read_unlock(addr_lock);
345 }
346 
347 /* Make a copy of all potential local addresses. */
348 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
349 				  struct net_device *dev)
350 {
351 	struct inet6_dev *in6_dev;
352 	struct inet6_ifaddr *ifp;
353 	struct sctp_sockaddr_entry *addr;
354 
355 	rcu_read_lock();
356 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
357 		rcu_read_unlock();
358 		return;
359 	}
360 
361 	read_lock_bh(&in6_dev->lock);
362 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
363 		/* Add the address to the local list.  */
364 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
365 		if (addr) {
366 			addr->a.v6.sin6_family = AF_INET6;
367 			addr->a.v6.sin6_port = 0;
368 			addr->a.v6.sin6_addr = ifp->addr;
369 			addr->a.v6.sin6_scope_id = dev->ifindex;
370 			INIT_LIST_HEAD(&addr->list);
371 			list_add_tail(&addr->list, addrlist);
372 		}
373 	}
374 
375 	read_unlock_bh(&in6_dev->lock);
376 	rcu_read_unlock();
377 }
378 
379 /* Initialize a sockaddr_storage from in incoming skb. */
380 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
381 			     int is_saddr)
382 {
383 	void *from;
384 	__be16 *port;
385 	struct sctphdr *sh;
386 
387 	port = &addr->v6.sin6_port;
388 	addr->v6.sin6_family = AF_INET6;
389 	addr->v6.sin6_flowinfo = 0; /* FIXME */
390 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
391 
392 	sh = sctp_hdr(skb);
393 	if (is_saddr) {
394 		*port  = sh->source;
395 		from = &ipv6_hdr(skb)->saddr;
396 	} else {
397 		*port = sh->dest;
398 		from = &ipv6_hdr(skb)->daddr;
399 	}
400 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
401 }
402 
403 /* Initialize an sctp_addr from a socket. */
404 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
405 {
406 	addr->v6.sin6_family = AF_INET6;
407 	addr->v6.sin6_port = 0;
408 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
409 }
410 
411 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
412 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
413 {
414 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
415 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
416 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
417 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
418 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
419 			addr->v4.sin_addr.s_addr;
420 	} else {
421 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
422 	}
423 }
424 
425 /* Initialize sk->sk_daddr from sctp_addr. */
426 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
427 {
428 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
429 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
430 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
431 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
432 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
433 	} else {
434 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
435 	}
436 }
437 
438 /* Initialize a sctp_addr from an address parameter. */
439 static void sctp_v6_from_addr_param(union sctp_addr *addr,
440 				    union sctp_addr_param *param,
441 				    __be16 port, int iif)
442 {
443 	addr->v6.sin6_family = AF_INET6;
444 	addr->v6.sin6_port = port;
445 	addr->v6.sin6_flowinfo = 0; /* BUG */
446 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
447 	addr->v6.sin6_scope_id = iif;
448 }
449 
450 /* Initialize an address parameter from a sctp_addr and return the length
451  * of the address parameter.
452  */
453 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
454 				 union sctp_addr_param *param)
455 {
456 	int length = sizeof(sctp_ipv6addr_param_t);
457 
458 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
459 	param->v6.param_hdr.length = htons(length);
460 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
461 
462 	return length;
463 }
464 
465 /* Initialize a sctp_addr from a dst_entry. */
466 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
467 			      __be16 port)
468 {
469 	struct rt6_info *rt = (struct rt6_info *)dst;
470 	addr->sa.sa_family = AF_INET6;
471 	addr->v6.sin6_port = port;
472 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
473 }
474 
475 /* Compare addresses exactly.
476  * v4-mapped-v6 is also in consideration.
477  */
478 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
479 			    const union sctp_addr *addr2)
480 {
481 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
482 		if (addr1->sa.sa_family == AF_INET &&
483 		    addr2->sa.sa_family == AF_INET6 &&
484 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
485 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
486 			    addr2->v6.sin6_addr.s6_addr32[3] ==
487 			    addr1->v4.sin_addr.s_addr)
488 				return 1;
489 		}
490 		if (addr2->sa.sa_family == AF_INET &&
491 		    addr1->sa.sa_family == AF_INET6 &&
492 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
493 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
494 			    addr1->v6.sin6_addr.s6_addr32[3] ==
495 			    addr2->v4.sin_addr.s_addr)
496 				return 1;
497 		}
498 		return 0;
499 	}
500 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
501 		return 0;
502 	/* If this is a linklocal address, compare the scope_id. */
503 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
504 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
505 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
506 			return 0;
507 		}
508 	}
509 
510 	return 1;
511 }
512 
513 /* Initialize addr struct to INADDR_ANY. */
514 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
515 {
516 	memset(addr, 0x00, sizeof(union sctp_addr));
517 	addr->v6.sin6_family = AF_INET6;
518 	addr->v6.sin6_port = port;
519 }
520 
521 /* Is this a wildcard address? */
522 static int sctp_v6_is_any(const union sctp_addr *addr)
523 {
524 	return ipv6_addr_any(&addr->v6.sin6_addr);
525 }
526 
527 /* Should this be available for binding?   */
528 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
529 {
530 	int type;
531 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
532 
533 	type = ipv6_addr_type(in6);
534 	if (IPV6_ADDR_ANY == type)
535 		return 1;
536 	if (type == IPV6_ADDR_MAPPED) {
537 		if (sp && !sp->v4mapped)
538 			return 0;
539 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
540 			return 0;
541 		sctp_v6_map_v4(addr);
542 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
543 	}
544 	if (!(type & IPV6_ADDR_UNICAST))
545 		return 0;
546 
547 	return ipv6_chk_addr(in6, NULL, 0);
548 }
549 
550 /* This function checks if the address is a valid address to be used for
551  * SCTP.
552  *
553  * Output:
554  * Return 0 - If the address is a non-unicast or an illegal address.
555  * Return 1 - If the address is a unicast.
556  */
557 static int sctp_v6_addr_valid(union sctp_addr *addr,
558 			      struct sctp_sock *sp,
559 			      const struct sk_buff *skb)
560 {
561 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
562 
563 	/* Support v4-mapped-v6 address. */
564 	if (ret == IPV6_ADDR_MAPPED) {
565 		/* Note: This routine is used in input, so v4-mapped-v6
566 		 * are disallowed here when there is no sctp_sock.
567 		 */
568 		if (!sp || !sp->v4mapped)
569 			return 0;
570 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
571 			return 0;
572 		sctp_v6_map_v4(addr);
573 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
574 	}
575 
576 	/* Is this a non-unicast address */
577 	if (!(ret & IPV6_ADDR_UNICAST))
578 		return 0;
579 
580 	return 1;
581 }
582 
583 /* What is the scope of 'addr'?  */
584 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
585 {
586 	int v6scope;
587 	sctp_scope_t retval;
588 
589 	/* The IPv6 scope is really a set of bit fields.
590 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
591 	 */
592 
593 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
594 	switch (v6scope) {
595 	case IFA_HOST:
596 		retval = SCTP_SCOPE_LOOPBACK;
597 		break;
598 	case IFA_LINK:
599 		retval = SCTP_SCOPE_LINK;
600 		break;
601 	case IFA_SITE:
602 		retval = SCTP_SCOPE_PRIVATE;
603 		break;
604 	default:
605 		retval = SCTP_SCOPE_GLOBAL;
606 		break;
607 	}
608 
609 	return retval;
610 }
611 
612 /* Create and initialize a new sk for the socket to be returned by accept(). */
613 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
614 					     struct sctp_association *asoc)
615 {
616 	struct inet_sock *inet = inet_sk(sk);
617 	struct sock *newsk;
618 	struct inet_sock *newinet;
619 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
620 	struct sctp6_sock *newsctp6sk;
621 
622 	newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
623 	if (!newsk)
624 		goto out;
625 
626 	sock_init_data(NULL, newsk);
627 
628 	newsk->sk_type = SOCK_STREAM;
629 
630 	newsk->sk_prot = sk->sk_prot;
631 	newsk->sk_no_check = sk->sk_no_check;
632 	newsk->sk_reuse = sk->sk_reuse;
633 
634 	newsk->sk_destruct = inet_sock_destruct;
635 	newsk->sk_family = PF_INET6;
636 	newsk->sk_protocol = IPPROTO_SCTP;
637 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
638 	newsk->sk_shutdown = sk->sk_shutdown;
639 	sock_reset_flag(sk, SOCK_ZAPPED);
640 
641 	newsctp6sk = (struct sctp6_sock *)newsk;
642 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
643 
644 	newinet = inet_sk(newsk);
645 	newnp = inet6_sk(newsk);
646 
647 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
648 
649 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
650 	 * and getpeername().
651 	 */
652 	newinet->sport = inet->sport;
653 	newnp->saddr = np->saddr;
654 	newnp->rcv_saddr = np->rcv_saddr;
655 	newinet->dport = htons(asoc->peer.port);
656 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
657 
658 	/* Init the ipv4 part of the socket since we can have sockets
659 	 * using v6 API for ipv4.
660 	 */
661 	newinet->uc_ttl = -1;
662 	newinet->mc_loop = 1;
663 	newinet->mc_ttl = 1;
664 	newinet->mc_index = 0;
665 	newinet->mc_list = NULL;
666 
667 	if (ipv4_config.no_pmtu_disc)
668 		newinet->pmtudisc = IP_PMTUDISC_DONT;
669 	else
670 		newinet->pmtudisc = IP_PMTUDISC_WANT;
671 
672 	sk_refcnt_debug_inc(newsk);
673 
674 	if (newsk->sk_prot->init(newsk)) {
675 		sk_common_release(newsk);
676 		newsk = NULL;
677 	}
678 
679 out:
680 	return newsk;
681 }
682 
683 /* Map v4 address to mapped v6 address */
684 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
685 {
686 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
687 		sctp_v4_map_v6(addr);
688 }
689 
690 /* Where did this skb come from?  */
691 static int sctp_v6_skb_iif(const struct sk_buff *skb)
692 {
693 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
694 	return opt->iif;
695 }
696 
697 /* Was this packet marked by Explicit Congestion Notification? */
698 static int sctp_v6_is_ce(const struct sk_buff *skb)
699 {
700 	return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20);
701 }
702 
703 /* Dump the v6 addr to the seq file. */
704 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
705 {
706 	seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
707 }
708 
709 /* Initialize a PF_INET6 socket msg_name. */
710 static void sctp_inet6_msgname(char *msgname, int *addr_len)
711 {
712 	struct sockaddr_in6 *sin6;
713 
714 	sin6 = (struct sockaddr_in6 *)msgname;
715 	sin6->sin6_family = AF_INET6;
716 	sin6->sin6_flowinfo = 0;
717 	sin6->sin6_scope_id = 0; /*FIXME */
718 	*addr_len = sizeof(struct sockaddr_in6);
719 }
720 
721 /* Initialize a PF_INET msgname from a ulpevent. */
722 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
723 				     char *msgname, int *addrlen)
724 {
725 	struct sockaddr_in6 *sin6, *sin6from;
726 
727 	if (msgname) {
728 		union sctp_addr *addr;
729 		struct sctp_association *asoc;
730 
731 		asoc = event->asoc;
732 		sctp_inet6_msgname(msgname, addrlen);
733 		sin6 = (struct sockaddr_in6 *)msgname;
734 		sin6->sin6_port = htons(asoc->peer.port);
735 		addr = &asoc->peer.primary_addr;
736 
737 		/* Note: If we go to a common v6 format, this code
738 		 * will change.
739 		 */
740 
741 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
742 		if (sctp_sk(asoc->base.sk)->v4mapped &&
743 		    AF_INET == addr->sa.sa_family) {
744 			sctp_v4_map_v6((union sctp_addr *)sin6);
745 			sin6->sin6_addr.s6_addr32[3] =
746 				addr->v4.sin_addr.s_addr;
747 			return;
748 		}
749 
750 		sin6from = &asoc->peer.primary_addr.v6;
751 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
752 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
753 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
754 	}
755 }
756 
757 /* Initialize a msg_name from an inbound skb. */
758 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
759 				   int *addr_len)
760 {
761 	struct sctphdr *sh;
762 	struct sockaddr_in6 *sin6;
763 
764 	if (msgname) {
765 		sctp_inet6_msgname(msgname, addr_len);
766 		sin6 = (struct sockaddr_in6 *)msgname;
767 		sh = sctp_hdr(skb);
768 		sin6->sin6_port = sh->source;
769 
770 		/* Map ipv4 address into v4-mapped-on-v6 address. */
771 		if (sctp_sk(skb->sk)->v4mapped &&
772 		    ip_hdr(skb)->version == 4) {
773 			sctp_v4_map_v6((union sctp_addr *)sin6);
774 			sin6->sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
775 			return;
776 		}
777 
778 		/* Otherwise, just copy the v6 address. */
779 		ipv6_addr_copy(&sin6->sin6_addr, &ipv6_hdr(skb)->saddr);
780 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
781 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
782 			sin6->sin6_scope_id = ev->iif;
783 		}
784 	}
785 }
786 
787 /* Do we support this AF? */
788 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
789 {
790 	switch (family) {
791 	case AF_INET6:
792 		return 1;
793 	/* v4-mapped-v6 addresses */
794 	case AF_INET:
795 		if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
796 			return 1;
797 	default:
798 		return 0;
799 	}
800 }
801 
802 /* Address matching with wildcards allowed.  This extra level
803  * of indirection lets us choose whether a PF_INET6 should
804  * disallow any v4 addresses if we so choose.
805  */
806 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
807 			       const union sctp_addr *addr2,
808 			       struct sctp_sock *opt)
809 {
810 	struct sctp_af *af1, *af2;
811 
812 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
813 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
814 
815 	if (!af1 || !af2)
816 		return 0;
817 	/* Today, wildcard AF_INET/AF_INET6. */
818 	if (sctp_is_any(addr1) || sctp_is_any(addr2))
819 		return 1;
820 
821 	if (addr1->sa.sa_family != addr2->sa.sa_family)
822 		return 0;
823 
824 	return af1->cmp_addr(addr1, addr2);
825 }
826 
827 /* Verify that the provided sockaddr looks bindable.   Common verification,
828  * has already been taken care of.
829  */
830 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
831 {
832 	struct sctp_af *af;
833 
834 	/* ASSERT: address family has already been verified. */
835 	if (addr->sa.sa_family != AF_INET6)
836 		af = sctp_get_af_specific(addr->sa.sa_family);
837 	else {
838 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
839 		struct net_device *dev;
840 
841 		if (type & IPV6_ADDR_LINKLOCAL) {
842 			if (!addr->v6.sin6_scope_id)
843 				return 0;
844 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
845 			if (!dev)
846 				return 0;
847 			dev_put(dev);
848 		}
849 		af = opt->pf->af;
850 	}
851 	return af->available(addr, opt);
852 }
853 
854 /* Verify that the provided sockaddr looks sendable.   Common verification,
855  * has already been taken care of.
856  */
857 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
858 {
859 	struct sctp_af *af = NULL;
860 
861 	/* ASSERT: address family has already been verified. */
862 	if (addr->sa.sa_family != AF_INET6)
863 		af = sctp_get_af_specific(addr->sa.sa_family);
864 	else {
865 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
866 		struct net_device *dev;
867 
868 		if (type & IPV6_ADDR_LINKLOCAL) {
869 			if (!addr->v6.sin6_scope_id)
870 				return 0;
871 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
872 			if (!dev)
873 				return 0;
874 			dev_put(dev);
875 		}
876 		af = opt->pf->af;
877 	}
878 
879 	return af != NULL;
880 }
881 
882 /* Fill in Supported Address Type information for INIT and INIT-ACK
883  * chunks.   Note: In the future, we may want to look at sock options
884  * to determine whether a PF_INET6 socket really wants to have IPV4
885  * addresses.
886  * Returns number of addresses supported.
887  */
888 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
889 				      __be16 *types)
890 {
891 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
892 	types[1] = SCTP_PARAM_IPV6_ADDRESS;
893 	return 2;
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 	.capability    = -1,
926 	.no_check      = 0,
927 	.flags         = SCTP_PROTOSW_FLAG
928 };
929 static struct inet_protosw sctpv6_stream_protosw = {
930 	.type          = SOCK_STREAM,
931 	.protocol      = IPPROTO_SCTP,
932 	.prot 	       = &sctpv6_prot,
933 	.ops           = &inet6_seqpacket_ops,
934 	.capability    = -1,
935 	.no_check      = 0,
936 	.flags         = SCTP_PROTOSW_FLAG,
937 };
938 
939 static int sctp6_rcv(struct sk_buff **pskb)
940 {
941 	return sctp_rcv(*pskb) ? -1 : 0;
942 }
943 
944 static struct inet6_protocol sctpv6_protocol = {
945 	.handler      = sctp6_rcv,
946 	.err_handler  = sctp_v6_err,
947 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
948 };
949 
950 static struct sctp_af sctp_ipv6_specific = {
951 	.sa_family	   = AF_INET6,
952 	.sctp_xmit	   = sctp_v6_xmit,
953 	.setsockopt	   = ipv6_setsockopt,
954 	.getsockopt	   = ipv6_getsockopt,
955 	.get_dst	   = sctp_v6_get_dst,
956 	.get_saddr	   = sctp_v6_get_saddr,
957 	.copy_addrlist	   = sctp_v6_copy_addrlist,
958 	.from_skb	   = sctp_v6_from_skb,
959 	.from_sk	   = sctp_v6_from_sk,
960 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
961 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
962 	.from_addr_param   = sctp_v6_from_addr_param,
963 	.to_addr_param	   = sctp_v6_to_addr_param,
964 	.dst_saddr	   = sctp_v6_dst_saddr,
965 	.cmp_addr	   = sctp_v6_cmp_addr,
966 	.scope		   = sctp_v6_scope,
967 	.addr_valid	   = sctp_v6_addr_valid,
968 	.inaddr_any	   = sctp_v6_inaddr_any,
969 	.is_any		   = sctp_v6_is_any,
970 	.available	   = sctp_v6_available,
971 	.skb_iif	   = sctp_v6_skb_iif,
972 	.is_ce		   = sctp_v6_is_ce,
973 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
974 	.net_header_len	   = sizeof(struct ipv6hdr),
975 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
976 #ifdef CONFIG_COMPAT
977 	.compat_setsockopt = compat_ipv6_setsockopt,
978 	.compat_getsockopt = compat_ipv6_getsockopt,
979 #endif
980 };
981 
982 static struct sctp_pf sctp_pf_inet6_specific = {
983 	.event_msgname = sctp_inet6_event_msgname,
984 	.skb_msgname   = sctp_inet6_skb_msgname,
985 	.af_supported  = sctp_inet6_af_supported,
986 	.cmp_addr      = sctp_inet6_cmp_addr,
987 	.bind_verify   = sctp_inet6_bind_verify,
988 	.send_verify   = sctp_inet6_send_verify,
989 	.supported_addrs = sctp_inet6_supported_addrs,
990 	.create_accept_sk = sctp_v6_create_accept_sk,
991 	.addr_v4map    = sctp_v6_addr_v4map,
992 	.af            = &sctp_ipv6_specific,
993 };
994 
995 /* Initialize IPv6 support and register with socket layer.  */
996 int sctp_v6_init(void)
997 {
998 	int rc;
999 
1000 	/* Register the SCTP specific PF_INET6 functions. */
1001 	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
1002 
1003 	/* Register the SCTP specific AF_INET6 functions. */
1004 	sctp_register_af(&sctp_ipv6_specific);
1005 
1006 	rc = proto_register(&sctpv6_prot, 1);
1007 	if (rc)
1008 		return rc;
1009 
1010 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1011 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1012 	inet6_register_protosw(&sctpv6_stream_protosw);
1013 
1014 	return 0;
1015 }
1016 
1017 /* Register with inet6 layer. */
1018 int sctp_v6_add_protocol(void)
1019 {
1020 	/* Register notifier for inet6 address additions/deletions. */
1021 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1022 
1023 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1024 		return -EAGAIN;
1025 
1026 	return 0;
1027 }
1028 
1029 /* IPv6 specific exit support. */
1030 void sctp_v6_exit(void)
1031 {
1032 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1033 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1034 	proto_unregister(&sctpv6_prot);
1035 	list_del(&sctp_ipv6_specific.list);
1036 }
1037 
1038 /* Unregister with inet6 layer. */
1039 void sctp_v6_del_protocol(void)
1040 {
1041 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1042 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1043 }
1044