xref: /linux/net/sctp/ipv6.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 ipv6hdr *iph = (struct ipv6hdr *)skb->data;
126 	struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
127 	struct sock *sk;
128 	struct sctp_association *asoc;
129 	struct sctp_transport *transport;
130 	struct ipv6_pinfo *np;
131 	char *saveip, *savesctp;
132 	int err;
133 
134 	idev = in6_dev_get(skb->dev);
135 
136 	/* Fix up skb to look at the embedded net header. */
137 	saveip = skb->nh.raw;
138 	savesctp  = skb->h.raw;
139 	skb->nh.ipv6h = iph;
140 	skb->h.raw = (char *)sh;
141 	sk = sctp_err_lookup(AF_INET6, skb, sh, &asoc, &transport);
142 	/* Put back, the original pointers. */
143 	skb->nh.raw = saveip;
144 	skb->h.raw = savesctp;
145 	if (!sk) {
146 		ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
147 		goto out;
148 	}
149 
150 	/* Warning:  The sock lock is held.  Remember to call
151 	 * sctp_err_finish!
152 	 */
153 
154 	switch (type) {
155 	case ICMPV6_PKT_TOOBIG:
156 		sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
157 		goto out_unlock;
158 	case ICMPV6_PARAMPROB:
159 		if (ICMPV6_UNK_NEXTHDR == code) {
160 			sctp_icmp_proto_unreachable(sk, asoc, transport);
161 			goto out_unlock;
162 		}
163 		break;
164 	default:
165 		break;
166 	}
167 
168 	np = inet6_sk(sk);
169 	icmpv6_err_convert(type, code, &err);
170 	if (!sock_owned_by_user(sk) && np->recverr) {
171 		sk->sk_err = err;
172 		sk->sk_error_report(sk);
173 	} else {  /* Only an error on timeout */
174 		sk->sk_err_soft = err;
175 	}
176 
177 out_unlock:
178 	sctp_err_finish(sk, asoc);
179 out:
180 	if (likely(idev != NULL))
181 		in6_dev_put(idev);
182 }
183 
184 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
185 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
186 			int ipfragok)
187 {
188 	struct sock *sk = skb->sk;
189 	struct ipv6_pinfo *np = inet6_sk(sk);
190 	struct flowi fl;
191 
192 	memset(&fl, 0, sizeof(fl));
193 
194 	fl.proto = sk->sk_protocol;
195 
196 	/* Fill in the dest address from the route entry passed with the skb
197 	 * and the source address from the transport.
198 	 */
199 	ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
200 	ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
201 
202 	fl.fl6_flowlabel = np->flow_label;
203 	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
204 	if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
205 		fl.oif = transport->saddr.v6.sin6_scope_id;
206 	else
207 		fl.oif = sk->sk_bound_dev_if;
208 
209 	if (np->opt && np->opt->srcrt) {
210 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
211 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
212 	}
213 
214 	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
215 			  "src:" NIP6_FMT " dst:" NIP6_FMT "\n",
216 			  __FUNCTION__, skb, skb->len,
217 			  NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
218 
219 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
220 
221 	return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
222 }
223 
224 /* Returns the dst cache entry for the given source and destination ip
225  * addresses.
226  */
227 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
228 					 union sctp_addr *daddr,
229 					 union sctp_addr *saddr)
230 {
231 	struct dst_entry *dst;
232 	struct flowi fl;
233 
234 	memset(&fl, 0, sizeof(fl));
235 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
236 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
237 		fl.oif = daddr->v6.sin6_scope_id;
238 
239 
240 	SCTP_DEBUG_PRINTK("%s: DST=" NIP6_FMT " ",
241 			  __FUNCTION__, NIP6(fl.fl6_dst));
242 
243 	if (saddr) {
244 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
245 		SCTP_DEBUG_PRINTK(
246 			"SRC=" NIP6_FMT " - ",
247 			NIP6(fl.fl6_src));
248 	}
249 
250 	dst = ip6_route_output(NULL, &fl);
251 	if (!dst->error) {
252 		struct rt6_info *rt;
253 		rt = (struct rt6_info *)dst;
254 		SCTP_DEBUG_PRINTK(
255 			"rt6_dst:" NIP6_FMT " rt6_src:" NIP6_FMT "\n",
256 			NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
257 		return dst;
258 	}
259 	SCTP_DEBUG_PRINTK("NO ROUTE\n");
260 	dst_release(dst);
261 	return NULL;
262 }
263 
264 /* Returns the number of consecutive initial bits that match in the 2 ipv6
265  * addresses.
266  */
267 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
268 					 union sctp_addr *s2)
269 {
270 	struct in6_addr *a1 = &s1->v6.sin6_addr;
271 	struct in6_addr *a2 = &s2->v6.sin6_addr;
272 	int i, j;
273 
274 	for (i = 0; i < 4 ; i++) {
275 		__be32 a1xora2;
276 
277 		a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
278 
279 		if ((j = fls(ntohl(a1xora2))))
280 			return (i * 32 + 32 - j);
281 	}
282 
283 	return (i*32);
284 }
285 
286 /* Fills in the source address(saddr) based on the destination address(daddr)
287  * and asoc's bind address list.
288  */
289 static void sctp_v6_get_saddr(struct sctp_association *asoc,
290 			      struct dst_entry *dst,
291 			      union sctp_addr *daddr,
292 			      union sctp_addr *saddr)
293 {
294 	struct sctp_bind_addr *bp;
295 	rwlock_t *addr_lock;
296 	struct sctp_sockaddr_entry *laddr;
297 	struct list_head *pos;
298 	sctp_scope_t scope;
299 	union sctp_addr *baddr = NULL;
300 	__u8 matchlen = 0;
301 	__u8 bmatchlen;
302 
303 	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
304 			  "daddr:" NIP6_FMT " ",
305 			  __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
306 
307 	if (!asoc) {
308 		ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
309 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",
310 				  NIP6(saddr->v6.sin6_addr));
311 		return;
312 	}
313 
314 	scope = sctp_scope(daddr);
315 
316 	bp = &asoc->base.bind_addr;
317 	addr_lock = &asoc->base.addr_lock;
318 
319 	/* Go through the bind address list and find the best source address
320 	 * that matches the scope of the destination address.
321 	 */
322 	sctp_read_lock(addr_lock);
323 	list_for_each(pos, &bp->address_list) {
324 		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
325 		if ((laddr->use_as_src) &&
326 		    (laddr->a.sa.sa_family == AF_INET6) &&
327 		    (scope <= sctp_scope(&laddr->a))) {
328 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
329 			if (!baddr || (matchlen < bmatchlen)) {
330 				baddr = &laddr->a;
331 				matchlen = bmatchlen;
332 			}
333 		}
334 	}
335 
336 	if (baddr) {
337 		memcpy(saddr, baddr, sizeof(union sctp_addr));
338 		SCTP_DEBUG_PRINTK("saddr: " NIP6_FMT "\n",
339 				  NIP6(saddr->v6.sin6_addr));
340 	} else {
341 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
342 		       "address for the dest:" NIP6_FMT "\n",
343 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
344 	}
345 
346 	sctp_read_unlock(addr_lock);
347 }
348 
349 /* Make a copy of all potential local addresses. */
350 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
351 				  struct net_device *dev)
352 {
353 	struct inet6_dev *in6_dev;
354 	struct inet6_ifaddr *ifp;
355 	struct sctp_sockaddr_entry *addr;
356 
357 	rcu_read_lock();
358 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
359 		rcu_read_unlock();
360 		return;
361 	}
362 
363 	read_lock_bh(&in6_dev->lock);
364 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
365 		/* Add the address to the local list.  */
366 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
367 		if (addr) {
368 			addr->a.v6.sin6_family = AF_INET6;
369 			addr->a.v6.sin6_port = 0;
370 			addr->a.v6.sin6_addr = ifp->addr;
371 			addr->a.v6.sin6_scope_id = dev->ifindex;
372 			INIT_LIST_HEAD(&addr->list);
373 			list_add_tail(&addr->list, addrlist);
374 		}
375 	}
376 
377 	read_unlock_bh(&in6_dev->lock);
378 	rcu_read_unlock();
379 }
380 
381 /* Initialize a sockaddr_storage from in incoming skb. */
382 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
383 			     int is_saddr)
384 {
385 	void *from;
386 	__be16 *port;
387 	struct sctphdr *sh;
388 
389 	port = &addr->v6.sin6_port;
390 	addr->v6.sin6_family = AF_INET6;
391 	addr->v6.sin6_flowinfo = 0; /* FIXME */
392 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
393 
394 	sh = (struct sctphdr *) skb->h.raw;
395 	if (is_saddr) {
396 		*port  = sh->source;
397 		from = &skb->nh.ipv6h->saddr;
398 	} else {
399 		*port = sh->dest;
400 		from = &skb->nh.ipv6h->daddr;
401 	}
402 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
403 }
404 
405 /* Initialize an sctp_addr from a socket. */
406 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
407 {
408 	addr->v6.sin6_family = AF_INET6;
409 	addr->v6.sin6_port = 0;
410 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
411 }
412 
413 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
414 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
415 {
416 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
417 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
418 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
419 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
420 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
421 			addr->v4.sin_addr.s_addr;
422 	} else {
423 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
424 	}
425 }
426 
427 /* Initialize sk->sk_daddr from sctp_addr. */
428 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
429 {
430 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
431 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
432 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
433 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
434 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
435 	} else {
436 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
437 	}
438 }
439 
440 /* Initialize a sctp_addr from an address parameter. */
441 static void sctp_v6_from_addr_param(union sctp_addr *addr,
442 				    union sctp_addr_param *param,
443 				    __be16 port, int iif)
444 {
445 	addr->v6.sin6_family = AF_INET6;
446 	addr->v6.sin6_port = port;
447 	addr->v6.sin6_flowinfo = 0; /* BUG */
448 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
449 	addr->v6.sin6_scope_id = iif;
450 }
451 
452 /* Initialize an address parameter from a sctp_addr and return the length
453  * of the address parameter.
454  */
455 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
456 				 union sctp_addr_param *param)
457 {
458 	int length = sizeof(sctp_ipv6addr_param_t);
459 
460 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
461 	param->v6.param_hdr.length = htons(length);
462 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
463 
464 	return length;
465 }
466 
467 /* Initialize a sctp_addr from a dst_entry. */
468 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
469 			      __be16 port)
470 {
471 	struct rt6_info *rt = (struct rt6_info *)dst;
472 	addr->sa.sa_family = AF_INET6;
473 	addr->v6.sin6_port = port;
474 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
475 }
476 
477 /* Compare addresses exactly.
478  * v4-mapped-v6 is also in consideration.
479  */
480 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
481 			    const union sctp_addr *addr2)
482 {
483 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
484 		if (addr1->sa.sa_family == AF_INET &&
485 		    addr2->sa.sa_family == AF_INET6 &&
486 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
487 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
488 			    addr2->v6.sin6_addr.s6_addr32[3] ==
489 			    addr1->v4.sin_addr.s_addr)
490 				return 1;
491 		}
492 		if (addr2->sa.sa_family == AF_INET &&
493 		    addr1->sa.sa_family == AF_INET6 &&
494 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
495 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
496 			    addr1->v6.sin6_addr.s6_addr32[3] ==
497 			    addr2->v4.sin_addr.s_addr)
498 				return 1;
499 		}
500 		return 0;
501 	}
502 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
503 		return 0;
504 	/* If this is a linklocal address, compare the scope_id. */
505 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
506 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
507 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
508 			return 0;
509 		}
510 	}
511 
512 	return 1;
513 }
514 
515 /* Initialize addr struct to INADDR_ANY. */
516 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
517 {
518 	memset(addr, 0x00, sizeof(union sctp_addr));
519 	addr->v6.sin6_family = AF_INET6;
520 	addr->v6.sin6_port = port;
521 }
522 
523 /* Is this a wildcard address? */
524 static int sctp_v6_is_any(const union sctp_addr *addr)
525 {
526 	return ipv6_addr_any(&addr->v6.sin6_addr);
527 }
528 
529 /* Should this be available for binding?   */
530 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
531 {
532 	int type;
533 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
534 
535 	type = ipv6_addr_type(in6);
536 	if (IPV6_ADDR_ANY == type)
537 		return 1;
538 	if (type == IPV6_ADDR_MAPPED) {
539 		if (sp && !sp->v4mapped)
540 			return 0;
541 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
542 			return 0;
543 		sctp_v6_map_v4(addr);
544 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
545 	}
546 	if (!(type & IPV6_ADDR_UNICAST))
547 		return 0;
548 
549 	return ipv6_chk_addr(in6, NULL, 0);
550 }
551 
552 /* This function checks if the address is a valid address to be used for
553  * SCTP.
554  *
555  * Output:
556  * Return 0 - If the address is a non-unicast or an illegal address.
557  * Return 1 - If the address is a unicast.
558  */
559 static int sctp_v6_addr_valid(union sctp_addr *addr,
560 			      struct sctp_sock *sp,
561 			      const struct sk_buff *skb)
562 {
563 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
564 
565 	/* Support v4-mapped-v6 address. */
566 	if (ret == IPV6_ADDR_MAPPED) {
567 		/* Note: This routine is used in input, so v4-mapped-v6
568 		 * are disallowed here when there is no sctp_sock.
569 		 */
570 		if (!sp || !sp->v4mapped)
571 			return 0;
572 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
573 			return 0;
574 		sctp_v6_map_v4(addr);
575 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
576 	}
577 
578 	/* Is this a non-unicast address */
579 	if (!(ret & IPV6_ADDR_UNICAST))
580 		return 0;
581 
582 	return 1;
583 }
584 
585 /* What is the scope of 'addr'?  */
586 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
587 {
588 	int v6scope;
589 	sctp_scope_t retval;
590 
591 	/* The IPv6 scope is really a set of bit fields.
592 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
593 	 */
594 
595 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
596 	switch (v6scope) {
597 	case IFA_HOST:
598 		retval = SCTP_SCOPE_LOOPBACK;
599 		break;
600 	case IFA_LINK:
601 		retval = SCTP_SCOPE_LINK;
602 		break;
603 	case IFA_SITE:
604 		retval = SCTP_SCOPE_PRIVATE;
605 		break;
606 	default:
607 		retval = SCTP_SCOPE_GLOBAL;
608 		break;
609 	};
610 
611 	return retval;
612 }
613 
614 /* Create and initialize a new sk for the socket to be returned by accept(). */
615 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
616 					     struct sctp_association *asoc)
617 {
618 	struct inet_sock *inet = inet_sk(sk);
619 	struct sock *newsk;
620 	struct inet_sock *newinet;
621 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
622 	struct sctp6_sock *newsctp6sk;
623 
624 	newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
625 	if (!newsk)
626 		goto out;
627 
628 	sock_init_data(NULL, newsk);
629 
630 	newsk->sk_type = SOCK_STREAM;
631 
632 	newsk->sk_prot = sk->sk_prot;
633 	newsk->sk_no_check = sk->sk_no_check;
634 	newsk->sk_reuse = sk->sk_reuse;
635 
636 	newsk->sk_destruct = inet_sock_destruct;
637 	newsk->sk_family = PF_INET6;
638 	newsk->sk_protocol = IPPROTO_SCTP;
639 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
640 	newsk->sk_shutdown = sk->sk_shutdown;
641 	sock_reset_flag(sk, SOCK_ZAPPED);
642 
643 	newsctp6sk = (struct sctp6_sock *)newsk;
644 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
645 
646 	newinet = inet_sk(newsk);
647 	newnp = inet6_sk(newsk);
648 
649 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
650 
651 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
652 	 * and getpeername().
653 	 */
654 	newinet->sport = inet->sport;
655 	newnp->saddr = np->saddr;
656 	newnp->rcv_saddr = np->rcv_saddr;
657 	newinet->dport = htons(asoc->peer.port);
658 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
659 
660 	/* Init the ipv4 part of the socket since we can have sockets
661 	 * using v6 API for ipv4.
662 	 */
663 	newinet->uc_ttl = -1;
664 	newinet->mc_loop = 1;
665 	newinet->mc_ttl = 1;
666 	newinet->mc_index = 0;
667 	newinet->mc_list = NULL;
668 
669 	if (ipv4_config.no_pmtu_disc)
670 		newinet->pmtudisc = IP_PMTUDISC_DONT;
671 	else
672 		newinet->pmtudisc = IP_PMTUDISC_WANT;
673 
674 	sk_refcnt_debug_inc(newsk);
675 
676 	if (newsk->sk_prot->init(newsk)) {
677 		sk_common_release(newsk);
678 		newsk = NULL;
679 	}
680 
681 out:
682 	return newsk;
683 }
684 
685 /* Map v4 address to mapped v6 address */
686 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
687 {
688 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
689 		sctp_v4_map_v6(addr);
690 }
691 
692 /* Where did this skb come from?  */
693 static int sctp_v6_skb_iif(const struct sk_buff *skb)
694 {
695 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
696 	return opt->iif;
697 }
698 
699 /* Was this packet marked by Explicit Congestion Notification? */
700 static int sctp_v6_is_ce(const struct sk_buff *skb)
701 {
702 	return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
703 }
704 
705 /* Dump the v6 addr to the seq file. */
706 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
707 {
708 	seq_printf(seq, NIP6_FMT " ", NIP6(addr->v6.sin6_addr));
709 }
710 
711 /* Initialize a PF_INET6 socket msg_name. */
712 static void sctp_inet6_msgname(char *msgname, int *addr_len)
713 {
714 	struct sockaddr_in6 *sin6;
715 
716 	sin6 = (struct sockaddr_in6 *)msgname;
717 	sin6->sin6_family = AF_INET6;
718 	sin6->sin6_flowinfo = 0;
719 	sin6->sin6_scope_id = 0; /*FIXME */
720 	*addr_len = sizeof(struct sockaddr_in6);
721 }
722 
723 /* Initialize a PF_INET msgname from a ulpevent. */
724 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
725 				     char *msgname, int *addrlen)
726 {
727 	struct sockaddr_in6 *sin6, *sin6from;
728 
729 	if (msgname) {
730 		union sctp_addr *addr;
731 		struct sctp_association *asoc;
732 
733 		asoc = event->asoc;
734 		sctp_inet6_msgname(msgname, addrlen);
735 		sin6 = (struct sockaddr_in6 *)msgname;
736 		sin6->sin6_port = htons(asoc->peer.port);
737 		addr = &asoc->peer.primary_addr;
738 
739 		/* Note: If we go to a common v6 format, this code
740 		 * will change.
741 		 */
742 
743 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
744 		if (sctp_sk(asoc->base.sk)->v4mapped &&
745 		    AF_INET == addr->sa.sa_family) {
746 			sctp_v4_map_v6((union sctp_addr *)sin6);
747 			sin6->sin6_addr.s6_addr32[3] =
748 				addr->v4.sin_addr.s_addr;
749 			return;
750 		}
751 
752 		sin6from = &asoc->peer.primary_addr.v6;
753 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
754 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
755 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
756 	}
757 }
758 
759 /* Initialize a msg_name from an inbound skb. */
760 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
761 				   int *addr_len)
762 {
763 	struct sctphdr *sh;
764 	struct sockaddr_in6 *sin6;
765 
766 	if (msgname) {
767 		sctp_inet6_msgname(msgname, addr_len);
768 		sin6 = (struct sockaddr_in6 *)msgname;
769 		sh = (struct sctphdr *)skb->h.raw;
770 		sin6->sin6_port = sh->source;
771 
772 		/* Map ipv4 address into v4-mapped-on-v6 address. */
773 		if (sctp_sk(skb->sk)->v4mapped &&
774 		    skb->nh.iph->version == 4) {
775 			sctp_v4_map_v6((union sctp_addr *)sin6);
776 			sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
777 			return;
778 		}
779 
780 		/* Otherwise, just copy the v6 address. */
781 		ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
782 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
783 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
784 			sin6->sin6_scope_id = ev->iif;
785 		}
786 	}
787 }
788 
789 /* Do we support this AF? */
790 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
791 {
792 	switch (family) {
793 	case AF_INET6:
794 		return 1;
795 	/* v4-mapped-v6 addresses */
796 	case AF_INET:
797 		if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
798 			return 1;
799 	default:
800 		return 0;
801 	}
802 }
803 
804 /* Address matching with wildcards allowed.  This extra level
805  * of indirection lets us choose whether a PF_INET6 should
806  * disallow any v4 addresses if we so choose.
807  */
808 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
809 			       const union sctp_addr *addr2,
810 			       struct sctp_sock *opt)
811 {
812 	struct sctp_af *af1, *af2;
813 
814 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
815 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
816 
817 	if (!af1 || !af2)
818 		return 0;
819 	/* Today, wildcard AF_INET/AF_INET6. */
820 	if (sctp_is_any(addr1) || sctp_is_any(addr2))
821 		return 1;
822 
823 	if (addr1->sa.sa_family != addr2->sa.sa_family)
824 		return 0;
825 
826 	return af1->cmp_addr(addr1, addr2);
827 }
828 
829 /* Verify that the provided sockaddr looks bindable.   Common verification,
830  * has already been taken care of.
831  */
832 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
833 {
834 	struct sctp_af *af;
835 
836 	/* ASSERT: address family has already been verified. */
837 	if (addr->sa.sa_family != AF_INET6)
838 		af = sctp_get_af_specific(addr->sa.sa_family);
839 	else {
840 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
841 		struct net_device *dev;
842 
843 		if (type & IPV6_ADDR_LINKLOCAL) {
844 			if (!addr->v6.sin6_scope_id)
845 				return 0;
846 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
847 			if (!dev)
848 				return 0;
849 			dev_put(dev);
850 		}
851 		af = opt->pf->af;
852 	}
853 	return af->available(addr, opt);
854 }
855 
856 /* Verify that the provided sockaddr looks sendable.   Common verification,
857  * has already been taken care of.
858  */
859 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
860 {
861 	struct sctp_af *af = NULL;
862 
863 	/* ASSERT: address family has already been verified. */
864 	if (addr->sa.sa_family != AF_INET6)
865 		af = sctp_get_af_specific(addr->sa.sa_family);
866 	else {
867 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
868 		struct net_device *dev;
869 
870 		if (type & IPV6_ADDR_LINKLOCAL) {
871 			if (!addr->v6.sin6_scope_id)
872 				return 0;
873 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
874 			if (!dev)
875 				return 0;
876 			dev_put(dev);
877 		}
878 		af = opt->pf->af;
879 	}
880 
881 	return af != NULL;
882 }
883 
884 /* Fill in Supported Address Type information for INIT and INIT-ACK
885  * chunks.   Note: In the future, we may want to look at sock options
886  * to determine whether a PF_INET6 socket really wants to have IPV4
887  * addresses.
888  * Returns number of addresses supported.
889  */
890 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
891 				      __be16 *types)
892 {
893 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
894 	types[1] = SCTP_PARAM_IPV6_ADDRESS;
895 	return 2;
896 }
897 
898 static const struct proto_ops inet6_seqpacket_ops = {
899 	.family		   = PF_INET6,
900 	.owner		   = THIS_MODULE,
901 	.release	   = inet6_release,
902 	.bind		   = inet6_bind,
903 	.connect	   = inet_dgram_connect,
904 	.socketpair	   = sock_no_socketpair,
905 	.accept		   = inet_accept,
906 	.getname	   = inet6_getname,
907 	.poll		   = sctp_poll,
908 	.ioctl		   = inet6_ioctl,
909 	.listen		   = sctp_inet_listen,
910 	.shutdown	   = inet_shutdown,
911 	.setsockopt	   = sock_common_setsockopt,
912 	.getsockopt	   = sock_common_getsockopt,
913 	.sendmsg	   = inet_sendmsg,
914 	.recvmsg	   = sock_common_recvmsg,
915 	.mmap		   = sock_no_mmap,
916 #ifdef CONFIG_COMPAT
917 	.compat_setsockopt = compat_sock_common_setsockopt,
918 	.compat_getsockopt = compat_sock_common_getsockopt,
919 #endif
920 };
921 
922 static struct inet_protosw sctpv6_seqpacket_protosw = {
923 	.type          = SOCK_SEQPACKET,
924 	.protocol      = IPPROTO_SCTP,
925 	.prot 	       = &sctpv6_prot,
926 	.ops           = &inet6_seqpacket_ops,
927 	.capability    = -1,
928 	.no_check      = 0,
929 	.flags         = SCTP_PROTOSW_FLAG
930 };
931 static struct inet_protosw sctpv6_stream_protosw = {
932 	.type          = SOCK_STREAM,
933 	.protocol      = IPPROTO_SCTP,
934 	.prot 	       = &sctpv6_prot,
935 	.ops           = &inet6_seqpacket_ops,
936 	.capability    = -1,
937 	.no_check      = 0,
938 	.flags         = SCTP_PROTOSW_FLAG,
939 };
940 
941 static int sctp6_rcv(struct sk_buff **pskb)
942 {
943 	return sctp_rcv(*pskb) ? -1 : 0;
944 }
945 
946 static struct inet6_protocol sctpv6_protocol = {
947 	.handler      = sctp6_rcv,
948 	.err_handler  = sctp_v6_err,
949 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
950 };
951 
952 static struct sctp_af sctp_ipv6_specific = {
953 	.sa_family	   = AF_INET6,
954 	.sctp_xmit	   = sctp_v6_xmit,
955 	.setsockopt	   = ipv6_setsockopt,
956 	.getsockopt	   = ipv6_getsockopt,
957 	.get_dst	   = sctp_v6_get_dst,
958 	.get_saddr	   = sctp_v6_get_saddr,
959 	.copy_addrlist	   = sctp_v6_copy_addrlist,
960 	.from_skb	   = sctp_v6_from_skb,
961 	.from_sk	   = sctp_v6_from_sk,
962 	.to_sk_saddr	   = sctp_v6_to_sk_saddr,
963 	.to_sk_daddr	   = sctp_v6_to_sk_daddr,
964 	.from_addr_param   = sctp_v6_from_addr_param,
965 	.to_addr_param	   = sctp_v6_to_addr_param,
966 	.dst_saddr	   = sctp_v6_dst_saddr,
967 	.cmp_addr	   = sctp_v6_cmp_addr,
968 	.scope		   = sctp_v6_scope,
969 	.addr_valid	   = sctp_v6_addr_valid,
970 	.inaddr_any	   = sctp_v6_inaddr_any,
971 	.is_any		   = sctp_v6_is_any,
972 	.available	   = sctp_v6_available,
973 	.skb_iif	   = sctp_v6_skb_iif,
974 	.is_ce		   = sctp_v6_is_ce,
975 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
976 	.net_header_len	   = sizeof(struct ipv6hdr),
977 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
978 #ifdef CONFIG_COMPAT
979 	.compat_setsockopt = compat_ipv6_setsockopt,
980 	.compat_getsockopt = compat_ipv6_getsockopt,
981 #endif
982 };
983 
984 static struct sctp_pf sctp_pf_inet6_specific = {
985 	.event_msgname = sctp_inet6_event_msgname,
986 	.skb_msgname   = sctp_inet6_skb_msgname,
987 	.af_supported  = sctp_inet6_af_supported,
988 	.cmp_addr      = sctp_inet6_cmp_addr,
989 	.bind_verify   = sctp_inet6_bind_verify,
990 	.send_verify   = sctp_inet6_send_verify,
991 	.supported_addrs = sctp_inet6_supported_addrs,
992 	.create_accept_sk = sctp_v6_create_accept_sk,
993 	.addr_v4map    = sctp_v6_addr_v4map,
994 	.af            = &sctp_ipv6_specific,
995 };
996 
997 /* Initialize IPv6 support and register with inet6 stack.  */
998 int sctp_v6_init(void)
999 {
1000 	int rc = proto_register(&sctpv6_prot, 1);
1001 
1002 	if (rc)
1003 		goto out;
1004 	/* Register inet6 protocol. */
1005 	rc = -EAGAIN;
1006 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1007 		goto out_unregister_sctp_proto;
1008 
1009 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1010 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1011 	inet6_register_protosw(&sctpv6_stream_protosw);
1012 
1013 	/* Register the SCTP specific PF_INET6 functions. */
1014 	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
1015 
1016 	/* Register the SCTP specific AF_INET6 functions. */
1017 	sctp_register_af(&sctp_ipv6_specific);
1018 
1019 	/* Register notifier for inet6 address additions/deletions. */
1020 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1021 	rc = 0;
1022 out:
1023 	return rc;
1024 out_unregister_sctp_proto:
1025 	proto_unregister(&sctpv6_prot);
1026 	goto out;
1027 }
1028 
1029 /* IPv6 specific exit support. */
1030 void sctp_v6_exit(void)
1031 {
1032 	list_del(&sctp_ipv6_specific.list);
1033 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1034 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1035 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1036 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1037 	proto_unregister(&sctpv6_prot);
1038 }
1039