xref: /openbmc/linux/net/sctp/ipv6.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
184 			  "dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
185 			  __FUNCTION__, skb, skb->len,
186 			  NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
187 
188 	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
189 
190 	return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
191 }
192 
193 /* Returns the dst cache entry for the given source and destination ip
194  * addresses.
195  */
196 static struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
197 					 union sctp_addr *daddr,
198 					 union sctp_addr *saddr)
199 {
200 	struct dst_entry *dst;
201 	struct flowi fl;
202 
203 	memset(&fl, 0, sizeof(fl));
204 	ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
205 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
206 		fl.oif = daddr->v6.sin6_scope_id;
207 
208 
209 	SCTP_DEBUG_PRINTK("%s: DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
210 			  __FUNCTION__, NIP6(fl.fl6_dst));
211 
212 	if (saddr) {
213 		ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
214 		SCTP_DEBUG_PRINTK(
215 			"SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x - ",
216 			NIP6(fl.fl6_src));
217 	}
218 
219 	dst = ip6_route_output(NULL, &fl);
220 	if (dst) {
221 		struct rt6_info *rt;
222 		rt = (struct rt6_info *)dst;
223 		SCTP_DEBUG_PRINTK(
224 			"rt6_dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
225 			"rt6_src:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
226 			NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
227 	} else {
228 		SCTP_DEBUG_PRINTK("NO ROUTE\n");
229 	}
230 
231 	return dst;
232 }
233 
234 /* Returns the number of consecutive initial bits that match in the 2 ipv6
235  * addresses.
236  */
237 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
238 					 union sctp_addr *s2)
239 {
240 	struct in6_addr *a1 = &s1->v6.sin6_addr;
241 	struct in6_addr *a2 = &s2->v6.sin6_addr;
242 	int i, j;
243 
244 	for (i = 0; i < 4 ; i++) {
245 		__u32 a1xora2;
246 
247 		a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
248 
249 		if ((j = fls(ntohl(a1xora2))))
250 			return (i * 32 + 32 - j);
251 	}
252 
253 	return (i*32);
254 }
255 
256 /* Fills in the source address(saddr) based on the destination address(daddr)
257  * and asoc's bind address list.
258  */
259 static void sctp_v6_get_saddr(struct sctp_association *asoc,
260 			      struct dst_entry *dst,
261 			      union sctp_addr *daddr,
262 			      union sctp_addr *saddr)
263 {
264 	struct sctp_bind_addr *bp;
265 	rwlock_t *addr_lock;
266 	struct sctp_sockaddr_entry *laddr;
267 	struct list_head *pos;
268 	sctp_scope_t scope;
269 	union sctp_addr *baddr = NULL;
270 	__u8 matchlen = 0;
271 	__u8 bmatchlen;
272 
273 	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
274 			  "daddr:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
275 			  __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
276 
277 	if (!asoc) {
278 		ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
279 		SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: "
280 				  "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
281 				  NIP6(saddr->v6.sin6_addr));
282 		return;
283 	}
284 
285 	scope = sctp_scope(daddr);
286 
287 	bp = &asoc->base.bind_addr;
288 	addr_lock = &asoc->base.addr_lock;
289 
290 	/* Go through the bind address list and find the best source address
291 	 * that matches the scope of the destination address.
292 	 */
293 	sctp_read_lock(addr_lock);
294 	list_for_each(pos, &bp->address_list) {
295 		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
296 		if ((laddr->a.sa.sa_family == AF_INET6) &&
297 		    (scope <= sctp_scope(&laddr->a))) {
298 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
299 			if (!baddr || (matchlen < bmatchlen)) {
300 				baddr = &laddr->a;
301 				matchlen = bmatchlen;
302 			}
303 		}
304 	}
305 
306 	if (baddr) {
307 		memcpy(saddr, baddr, sizeof(union sctp_addr));
308 		SCTP_DEBUG_PRINTK("saddr: "
309 				  "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
310 				  NIP6(saddr->v6.sin6_addr));
311 	} else {
312 		printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
313 		       "address for the "
314 		       "dest:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
315 		       __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
316 	}
317 
318 	sctp_read_unlock(addr_lock);
319 }
320 
321 /* Make a copy of all potential local addresses. */
322 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
323 				  struct net_device *dev)
324 {
325 	struct inet6_dev *in6_dev;
326 	struct inet6_ifaddr *ifp;
327 	struct sctp_sockaddr_entry *addr;
328 
329 	read_lock(&addrconf_lock);
330 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
331 		read_unlock(&addrconf_lock);
332 		return;
333 	}
334 
335 	read_lock(&in6_dev->lock);
336 	for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
337 		/* Add the address to the local list.  */
338 		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
339 		if (addr) {
340 			addr->a.v6.sin6_family = AF_INET6;
341 			addr->a.v6.sin6_port = 0;
342 			addr->a.v6.sin6_addr = ifp->addr;
343 			addr->a.v6.sin6_scope_id = dev->ifindex;
344 			INIT_LIST_HEAD(&addr->list);
345 			list_add_tail(&addr->list, addrlist);
346 		}
347 	}
348 
349 	read_unlock(&in6_dev->lock);
350 	read_unlock(&addrconf_lock);
351 }
352 
353 /* Initialize a sockaddr_storage from in incoming skb. */
354 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
355 			     int is_saddr)
356 {
357 	void *from;
358 	__u16 *port;
359 	struct sctphdr *sh;
360 
361 	port = &addr->v6.sin6_port;
362 	addr->v6.sin6_family = AF_INET6;
363 	addr->v6.sin6_flowinfo = 0; /* FIXME */
364 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
365 
366 	sh = (struct sctphdr *) skb->h.raw;
367 	if (is_saddr) {
368 		*port  = ntohs(sh->source);
369 		from = &skb->nh.ipv6h->saddr;
370 	} else {
371 		*port = ntohs(sh->dest);
372 		from = &skb->nh.ipv6h->daddr;
373 	}
374 	ipv6_addr_copy(&addr->v6.sin6_addr, from);
375 }
376 
377 /* Initialize an sctp_addr from a socket. */
378 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
379 {
380 	addr->v6.sin6_family = AF_INET6;
381 	addr->v6.sin6_port = inet_sk(sk)->num;
382 	addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
383 }
384 
385 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
386 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
387 {
388 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
389 		inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
390 		inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
391 		inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
392 		inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
393 			addr->v4.sin_addr.s_addr;
394 	} else {
395 		inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
396 	}
397 }
398 
399 /* Initialize sk->sk_daddr from sctp_addr. */
400 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
401 {
402 	if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
403 		inet6_sk(sk)->daddr.s6_addr32[0] = 0;
404 		inet6_sk(sk)->daddr.s6_addr32[1] = 0;
405 		inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
406 		inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
407 	} else {
408 		inet6_sk(sk)->daddr = addr->v6.sin6_addr;
409 	}
410 }
411 
412 /* Initialize a sctp_addr from an address parameter. */
413 static void sctp_v6_from_addr_param(union sctp_addr *addr,
414 				    union sctp_addr_param *param,
415 				    __u16 port, int iif)
416 {
417 	addr->v6.sin6_family = AF_INET6;
418 	addr->v6.sin6_port = port;
419 	addr->v6.sin6_flowinfo = 0; /* BUG */
420 	ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
421 	addr->v6.sin6_scope_id = iif;
422 }
423 
424 /* Initialize an address parameter from a sctp_addr and return the length
425  * of the address parameter.
426  */
427 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
428 				 union sctp_addr_param *param)
429 {
430 	int length = sizeof(sctp_ipv6addr_param_t);
431 
432 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
433 	param->v6.param_hdr.length = ntohs(length);
434 	ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
435 
436 	return length;
437 }
438 
439 /* Initialize a sctp_addr from a dst_entry. */
440 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
441 			      unsigned short port)
442 {
443 	struct rt6_info *rt = (struct rt6_info *)dst;
444 	addr->sa.sa_family = AF_INET6;
445 	addr->v6.sin6_port = port;
446 	ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
447 }
448 
449 /* Compare addresses exactly.
450  * v4-mapped-v6 is also in consideration.
451  */
452 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
453 			    const union sctp_addr *addr2)
454 {
455 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
456 		if (addr1->sa.sa_family == AF_INET &&
457 		    addr2->sa.sa_family == AF_INET6 &&
458 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
459 			if (addr2->v6.sin6_port == addr1->v4.sin_port &&
460 			    addr2->v6.sin6_addr.s6_addr32[3] ==
461 			    addr1->v4.sin_addr.s_addr)
462 				return 1;
463 		}
464 		if (addr2->sa.sa_family == AF_INET &&
465 		    addr1->sa.sa_family == AF_INET6 &&
466 		    IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
467 			if (addr1->v6.sin6_port == addr2->v4.sin_port &&
468 			    addr1->v6.sin6_addr.s6_addr32[3] ==
469 			    addr2->v4.sin_addr.s_addr)
470 				return 1;
471 		}
472 		return 0;
473 	}
474 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
475 		return 0;
476 	/* If this is a linklocal address, compare the scope_id. */
477 	if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
478 		if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
479 		    (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
480 			return 0;
481 		}
482 	}
483 
484 	return 1;
485 }
486 
487 /* Initialize addr struct to INADDR_ANY. */
488 static void sctp_v6_inaddr_any(union sctp_addr *addr, unsigned short port)
489 {
490 	memset(addr, 0x00, sizeof(union sctp_addr));
491 	addr->v6.sin6_family = AF_INET6;
492 	addr->v6.sin6_port = port;
493 }
494 
495 /* Is this a wildcard address? */
496 static int sctp_v6_is_any(const union sctp_addr *addr)
497 {
498 	return ipv6_addr_any(&addr->v6.sin6_addr);
499 }
500 
501 /* Should this be available for binding?   */
502 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
503 {
504 	int type;
505 	struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
506 
507 	type = ipv6_addr_type(in6);
508 	if (IPV6_ADDR_ANY == type)
509 		return 1;
510 	if (type == IPV6_ADDR_MAPPED) {
511 		if (sp && !sp->v4mapped)
512 			return 0;
513 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
514 			return 0;
515 		sctp_v6_map_v4(addr);
516 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
517 	}
518 	if (!(type & IPV6_ADDR_UNICAST))
519 		return 0;
520 
521 	return ipv6_chk_addr(in6, NULL, 0);
522 }
523 
524 /* This function checks if the address is a valid address to be used for
525  * SCTP.
526  *
527  * Output:
528  * Return 0 - If the address is a non-unicast or an illegal address.
529  * Return 1 - If the address is a unicast.
530  */
531 static int sctp_v6_addr_valid(union sctp_addr *addr, struct sctp_sock *sp)
532 {
533 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
534 
535 	/* Support v4-mapped-v6 address. */
536 	if (ret == IPV6_ADDR_MAPPED) {
537 		/* Note: This routine is used in input, so v4-mapped-v6
538 		 * are disallowed here when there is no sctp_sock.
539 		 */
540 		if (!sp || !sp->v4mapped)
541 			return 0;
542 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
543 			return 0;
544 		sctp_v6_map_v4(addr);
545 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp);
546 	}
547 
548 	/* Is this a non-unicast address */
549 	if (!(ret & IPV6_ADDR_UNICAST))
550 		return 0;
551 
552 	return 1;
553 }
554 
555 /* What is the scope of 'addr'?  */
556 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
557 {
558 	int v6scope;
559 	sctp_scope_t retval;
560 
561 	/* The IPv6 scope is really a set of bit fields.
562 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
563 	 */
564 
565 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
566 	switch (v6scope) {
567 	case IFA_HOST:
568 		retval = SCTP_SCOPE_LOOPBACK;
569 		break;
570 	case IFA_LINK:
571 		retval = SCTP_SCOPE_LINK;
572 		break;
573 	case IFA_SITE:
574 		retval = SCTP_SCOPE_PRIVATE;
575 		break;
576 	default:
577 		retval = SCTP_SCOPE_GLOBAL;
578 		break;
579 	};
580 
581 	return retval;
582 }
583 
584 /* Create and initialize a new sk for the socket to be returned by accept(). */
585 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
586 					     struct sctp_association *asoc)
587 {
588 	struct inet_sock *inet = inet_sk(sk);
589 	struct sock *newsk;
590 	struct inet_sock *newinet;
591 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
592 	struct sctp6_sock *newsctp6sk;
593 
594 	newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot, 1);
595 	if (!newsk)
596 		goto out;
597 
598 	sock_init_data(NULL, newsk);
599 
600 	newsk->sk_type = SOCK_STREAM;
601 
602 	newsk->sk_prot = sk->sk_prot;
603 	newsk->sk_no_check = sk->sk_no_check;
604 	newsk->sk_reuse = sk->sk_reuse;
605 
606 	newsk->sk_destruct = inet_sock_destruct;
607 	newsk->sk_family = PF_INET6;
608 	newsk->sk_protocol = IPPROTO_SCTP;
609 	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
610 	newsk->sk_shutdown = sk->sk_shutdown;
611 	sock_reset_flag(sk, SOCK_ZAPPED);
612 
613 	newsctp6sk = (struct sctp6_sock *)newsk;
614 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
615 
616 	newinet = inet_sk(newsk);
617 	newnp = inet6_sk(newsk);
618 
619 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
620 
621 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
622 	 * and getpeername().
623 	 */
624 	newinet->sport = inet->sport;
625 	newnp->saddr = np->saddr;
626 	newnp->rcv_saddr = np->rcv_saddr;
627 	newinet->dport = htons(asoc->peer.port);
628 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
629 
630 	/* Init the ipv4 part of the socket since we can have sockets
631 	 * using v6 API for ipv4.
632 	 */
633 	newinet->uc_ttl = -1;
634 	newinet->mc_loop = 1;
635 	newinet->mc_ttl = 1;
636 	newinet->mc_index = 0;
637 	newinet->mc_list = NULL;
638 
639 	if (ipv4_config.no_pmtu_disc)
640 		newinet->pmtudisc = IP_PMTUDISC_DONT;
641 	else
642 		newinet->pmtudisc = IP_PMTUDISC_WANT;
643 
644 	sk_refcnt_debug_inc(newsk);
645 
646 	if (newsk->sk_prot->init(newsk)) {
647 		sk_common_release(newsk);
648 		newsk = NULL;
649 	}
650 
651 out:
652 	return newsk;
653 }
654 
655 /* Map v4 address to mapped v6 address */
656 static void sctp_v6_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
657 {
658 	if (sp->v4mapped && AF_INET == addr->sa.sa_family)
659 		sctp_v4_map_v6(addr);
660 }
661 
662 /* Where did this skb come from?  */
663 static int sctp_v6_skb_iif(const struct sk_buff *skb)
664 {
665 	struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
666 	return opt->iif;
667 }
668 
669 /* Was this packet marked by Explicit Congestion Notification? */
670 static int sctp_v6_is_ce(const struct sk_buff *skb)
671 {
672 	return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
673 }
674 
675 /* Dump the v6 addr to the seq file. */
676 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
677 {
678 	seq_printf(seq, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
679 		   NIP6(addr->v6.sin6_addr));
680 }
681 
682 /* Initialize a PF_INET6 socket msg_name. */
683 static void sctp_inet6_msgname(char *msgname, int *addr_len)
684 {
685 	struct sockaddr_in6 *sin6;
686 
687 	sin6 = (struct sockaddr_in6 *)msgname;
688 	sin6->sin6_family = AF_INET6;
689 	sin6->sin6_flowinfo = 0;
690 	sin6->sin6_scope_id = 0; /*FIXME */
691 	*addr_len = sizeof(struct sockaddr_in6);
692 }
693 
694 /* Initialize a PF_INET msgname from a ulpevent. */
695 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
696 				     char *msgname, int *addrlen)
697 {
698 	struct sockaddr_in6 *sin6, *sin6from;
699 
700 	if (msgname) {
701 		union sctp_addr *addr;
702 		struct sctp_association *asoc;
703 
704 		asoc = event->asoc;
705 		sctp_inet6_msgname(msgname, addrlen);
706 		sin6 = (struct sockaddr_in6 *)msgname;
707 		sin6->sin6_port = htons(asoc->peer.port);
708 		addr = &asoc->peer.primary_addr;
709 
710 		/* Note: If we go to a common v6 format, this code
711 		 * will change.
712 		 */
713 
714 		/* Map ipv4 address into v4-mapped-on-v6 address.  */
715 		if (sctp_sk(asoc->base.sk)->v4mapped &&
716 		    AF_INET == addr->sa.sa_family) {
717 			sctp_v4_map_v6((union sctp_addr *)sin6);
718 			sin6->sin6_addr.s6_addr32[3] =
719 				addr->v4.sin_addr.s_addr;
720 			return;
721 		}
722 
723 		sin6from = &asoc->peer.primary_addr.v6;
724 		ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
725 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
726 			sin6->sin6_scope_id = sin6from->sin6_scope_id;
727 	}
728 }
729 
730 /* Initialize a msg_name from an inbound skb. */
731 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
732 				   int *addr_len)
733 {
734 	struct sctphdr *sh;
735 	struct sockaddr_in6 *sin6;
736 
737 	if (msgname) {
738 		sctp_inet6_msgname(msgname, addr_len);
739 		sin6 = (struct sockaddr_in6 *)msgname;
740 		sh = (struct sctphdr *)skb->h.raw;
741 		sin6->sin6_port = sh->source;
742 
743 		/* Map ipv4 address into v4-mapped-on-v6 address. */
744 		if (sctp_sk(skb->sk)->v4mapped &&
745 		    skb->nh.iph->version == 4) {
746 			sctp_v4_map_v6((union sctp_addr *)sin6);
747 			sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
748 			return;
749 		}
750 
751 		/* Otherwise, just copy the v6 address. */
752 		ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
753 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
754 			struct sctp_ulpevent *ev = sctp_skb2event(skb);
755 			sin6->sin6_scope_id = ev->iif;
756 		}
757 	}
758 }
759 
760 /* Do we support this AF? */
761 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
762 {
763 	switch (family) {
764 	case AF_INET6:
765 		return 1;
766 	/* v4-mapped-v6 addresses */
767 	case AF_INET:
768 		if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
769 			return 1;
770 	default:
771 		return 0;
772 	}
773 }
774 
775 /* Address matching with wildcards allowed.  This extra level
776  * of indirection lets us choose whether a PF_INET6 should
777  * disallow any v4 addresses if we so choose.
778  */
779 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
780 			       const union sctp_addr *addr2,
781 			       struct sctp_sock *opt)
782 {
783 	struct sctp_af *af1, *af2;
784 
785 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
786 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
787 
788 	if (!af1 || !af2)
789 		return 0;
790 	/* Today, wildcard AF_INET/AF_INET6. */
791 	if (sctp_is_any(addr1) || sctp_is_any(addr2))
792 		return 1;
793 
794 	if (addr1->sa.sa_family != addr2->sa.sa_family)
795 		return 0;
796 
797 	return af1->cmp_addr(addr1, addr2);
798 }
799 
800 /* Verify that the provided sockaddr looks bindable.   Common verification,
801  * has already been taken care of.
802  */
803 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
804 {
805 	struct sctp_af *af;
806 
807 	/* ASSERT: address family has already been verified. */
808 	if (addr->sa.sa_family != AF_INET6)
809 		af = sctp_get_af_specific(addr->sa.sa_family);
810 	else {
811 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
812 		struct net_device *dev;
813 
814 		if (type & IPV6_ADDR_LINKLOCAL) {
815 			if (!addr->v6.sin6_scope_id)
816 				return 0;
817 			dev = dev_get_by_index(addr->v6.sin6_scope_id);
818 			if (!dev)
819 				return 0;
820 			dev_put(dev);
821 		}
822 		af = opt->pf->af;
823 	}
824 	return af->available(addr, opt);
825 }
826 
827 /* Verify that the provided sockaddr looks sendable.   Common verification,
828  * has already been taken care of.
829  */
830 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
831 {
832 	struct sctp_af *af = NULL;
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 
852 	return af != NULL;
853 }
854 
855 /* Fill in Supported Address Type information for INIT and INIT-ACK
856  * chunks.   Note: In the future, we may want to look at sock options
857  * to determine whether a PF_INET6 socket really wants to have IPV4
858  * addresses.
859  * Returns number of addresses supported.
860  */
861 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
862 				      __u16 *types)
863 {
864 	types[0] = SCTP_PARAM_IPV4_ADDRESS;
865 	types[1] = SCTP_PARAM_IPV6_ADDRESS;
866 	return 2;
867 }
868 
869 static struct proto_ops inet6_seqpacket_ops = {
870 	.family     = PF_INET6,
871 	.owner      = THIS_MODULE,
872 	.release    = inet6_release,
873 	.bind       = inet6_bind,
874 	.connect    = inet_dgram_connect,
875 	.socketpair = sock_no_socketpair,
876 	.accept     = inet_accept,
877 	.getname    = inet6_getname,
878 	.poll       = sctp_poll,
879 	.ioctl      = inet6_ioctl,
880 	.listen     = sctp_inet_listen,
881 	.shutdown   = inet_shutdown,
882 	.setsockopt = sock_common_setsockopt,
883 	.getsockopt = sock_common_getsockopt,
884 	.sendmsg    = inet_sendmsg,
885 	.recvmsg    = sock_common_recvmsg,
886 	.mmap       = sock_no_mmap,
887 };
888 
889 static struct inet_protosw sctpv6_seqpacket_protosw = {
890 	.type          = SOCK_SEQPACKET,
891 	.protocol      = IPPROTO_SCTP,
892 	.prot 	       = &sctpv6_prot,
893 	.ops           = &inet6_seqpacket_ops,
894 	.capability    = -1,
895 	.no_check      = 0,
896 	.flags         = SCTP_PROTOSW_FLAG
897 };
898 static struct inet_protosw sctpv6_stream_protosw = {
899 	.type          = SOCK_STREAM,
900 	.protocol      = IPPROTO_SCTP,
901 	.prot 	       = &sctpv6_prot,
902 	.ops           = &inet6_seqpacket_ops,
903 	.capability    = -1,
904 	.no_check      = 0,
905 	.flags         = SCTP_PROTOSW_FLAG,
906 };
907 
908 static int sctp6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
909 {
910 	return sctp_rcv(*pskb) ? -1 : 0;
911 }
912 
913 static struct inet6_protocol sctpv6_protocol = {
914 	.handler      = sctp6_rcv,
915 	.err_handler  = sctp_v6_err,
916 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
917 };
918 
919 static struct sctp_af sctp_ipv6_specific = {
920 	.sctp_xmit       = sctp_v6_xmit,
921 	.setsockopt      = ipv6_setsockopt,
922 	.getsockopt      = ipv6_getsockopt,
923 	.get_dst	 = sctp_v6_get_dst,
924 	.get_saddr	 = sctp_v6_get_saddr,
925 	.copy_addrlist   = sctp_v6_copy_addrlist,
926 	.from_skb        = sctp_v6_from_skb,
927 	.from_sk         = sctp_v6_from_sk,
928 	.to_sk_saddr     = sctp_v6_to_sk_saddr,
929 	.to_sk_daddr     = sctp_v6_to_sk_daddr,
930 	.from_addr_param = sctp_v6_from_addr_param,
931 	.to_addr_param   = sctp_v6_to_addr_param,
932 	.dst_saddr       = sctp_v6_dst_saddr,
933 	.cmp_addr        = sctp_v6_cmp_addr,
934 	.scope           = sctp_v6_scope,
935 	.addr_valid      = sctp_v6_addr_valid,
936 	.inaddr_any      = sctp_v6_inaddr_any,
937 	.is_any          = sctp_v6_is_any,
938 	.available       = sctp_v6_available,
939 	.skb_iif         = sctp_v6_skb_iif,
940 	.is_ce           = sctp_v6_is_ce,
941 	.seq_dump_addr   = sctp_v6_seq_dump_addr,
942 	.net_header_len  = sizeof(struct ipv6hdr),
943 	.sockaddr_len    = sizeof(struct sockaddr_in6),
944 	.sa_family       = AF_INET6,
945 };
946 
947 static struct sctp_pf sctp_pf_inet6_specific = {
948 	.event_msgname = sctp_inet6_event_msgname,
949 	.skb_msgname   = sctp_inet6_skb_msgname,
950 	.af_supported  = sctp_inet6_af_supported,
951 	.cmp_addr      = sctp_inet6_cmp_addr,
952 	.bind_verify   = sctp_inet6_bind_verify,
953 	.send_verify   = sctp_inet6_send_verify,
954 	.supported_addrs = sctp_inet6_supported_addrs,
955 	.create_accept_sk = sctp_v6_create_accept_sk,
956 	.addr_v4map    = sctp_v6_addr_v4map,
957 	.af            = &sctp_ipv6_specific,
958 };
959 
960 /* Initialize IPv6 support and register with inet6 stack.  */
961 int sctp_v6_init(void)
962 {
963 	int rc = proto_register(&sctpv6_prot, 1);
964 
965 	if (rc)
966 		goto out;
967 	/* Register inet6 protocol. */
968 	rc = -EAGAIN;
969 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
970 		goto out_unregister_sctp_proto;
971 
972 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
973 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
974 	inet6_register_protosw(&sctpv6_stream_protosw);
975 
976 	/* Register the SCTP specific PF_INET6 functions. */
977 	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
978 
979 	/* Register the SCTP specific AF_INET6 functions. */
980 	sctp_register_af(&sctp_ipv6_specific);
981 
982 	/* Register notifier for inet6 address additions/deletions. */
983 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
984 	rc = 0;
985 out:
986 	return rc;
987 out_unregister_sctp_proto:
988 	proto_unregister(&sctpv6_prot);
989 	goto out;
990 }
991 
992 /* IPv6 specific exit support. */
993 void sctp_v6_exit(void)
994 {
995 	list_del(&sctp_ipv6_specific.list);
996 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
997 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
998 	inet6_unregister_protosw(&sctpv6_stream_protosw);
999 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1000 	proto_unregister(&sctpv6_prot);
1001 }
1002