1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2002, 2004
4  * Copyright (c) 2001 Nokia, Inc.
5  * Copyright (c) 2001 La Monte H.P. Yarroll
6  * Copyright (c) 2002-2003 Intel Corp.
7  *
8  * This file is part of the SCTP kernel implementation
9  *
10  * SCTP over IPv6.
11  *
12  * Please send any bug reports or fixes you make to the
13  * email address(es):
14  *    lksctp developers <linux-sctp@vger.kernel.org>
15  *
16  * Written or modified by:
17  *    Le Yanqun		    <yanqun.le@nokia.com>
18  *    Hui Huang		    <hui.huang@nokia.com>
19  *    La Monte H.P. Yarroll <piggy@acm.org>
20  *    Sridhar Samudrala	    <sri@us.ibm.com>
21  *    Jon Grimm		    <jgrimm@us.ibm.com>
22  *    Ardelle Fan	    <ardelle.fan@intel.com>
23  *
24  * Based on:
25  *	linux/net/ipv6/tcp_ipv6.c
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/netdevice.h>
39 #include <linux/init.h>
40 #include <linux/ipsec.h>
41 #include <linux/slab.h>
42 
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46 #include <linux/seq_file.h>
47 
48 #include <net/protocol.h>
49 #include <net/ndisc.h>
50 #include <net/ip.h>
51 #include <net/ipv6.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/inet_common.h>
56 #include <net/inet_ecn.h>
57 #include <net/sctp/sctp.h>
58 #include <net/udp_tunnel.h>
59 
60 #include <linux/uaccess.h>
61 
62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
63 					 union sctp_addr *s2);
64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
65 			      __be16 port);
66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
67 			    const union sctp_addr *addr2);
68 
69 /* Event handler for inet6 address addition/deletion events.
70  * The sctp_local_addr_list needs to be protocted by a spin lock since
71  * multiple notifiers (say IPv4 and IPv6) may be running at the same
72  * time and thus corrupt the list.
73  * The reader side is protected with RCU.
74  */
sctp_inet6addr_event(struct notifier_block * this,unsigned long ev,void * ptr)75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
76 				void *ptr)
77 {
78 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
79 	struct sctp_sockaddr_entry *addr = NULL;
80 	struct sctp_sockaddr_entry *temp;
81 	struct net *net = dev_net(ifa->idev->dev);
82 	int found = 0;
83 
84 	switch (ev) {
85 	case NETDEV_UP:
86 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
87 		if (addr) {
88 			addr->a.v6.sin6_family = AF_INET6;
89 			addr->a.v6.sin6_addr = ifa->addr;
90 			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
91 			addr->valid = 1;
92 			spin_lock_bh(&net->sctp.local_addr_lock);
93 			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
94 			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
95 			spin_unlock_bh(&net->sctp.local_addr_lock);
96 		}
97 		break;
98 	case NETDEV_DOWN:
99 		spin_lock_bh(&net->sctp.local_addr_lock);
100 		list_for_each_entry_safe(addr, temp,
101 					&net->sctp.local_addr_list, list) {
102 			if (addr->a.sa.sa_family == AF_INET6 &&
103 			    ipv6_addr_equal(&addr->a.v6.sin6_addr,
104 					    &ifa->addr) &&
105 			    addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {
106 				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
107 				found = 1;
108 				addr->valid = 0;
109 				list_del_rcu(&addr->list);
110 				break;
111 			}
112 		}
113 		spin_unlock_bh(&net->sctp.local_addr_lock);
114 		if (found)
115 			kfree_rcu(addr, rcu);
116 		break;
117 	}
118 
119 	return NOTIFY_DONE;
120 }
121 
122 static struct notifier_block sctp_inet6addr_notifier = {
123 	.notifier_call = sctp_inet6addr_event,
124 };
125 
sctp_v6_err_handle(struct sctp_transport * t,struct sk_buff * skb,__u8 type,__u8 code,__u32 info)126 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb,
127 			       __u8 type, __u8 code, __u32 info)
128 {
129 	struct sctp_association *asoc = t->asoc;
130 	struct sock *sk = asoc->base.sk;
131 	int err = 0;
132 
133 	switch (type) {
134 	case ICMPV6_PKT_TOOBIG:
135 		if (ip6_sk_accept_pmtu(sk))
136 			sctp_icmp_frag_needed(sk, asoc, t, info);
137 		return;
138 	case ICMPV6_PARAMPROB:
139 		if (ICMPV6_UNK_NEXTHDR == code) {
140 			sctp_icmp_proto_unreachable(sk, asoc, t);
141 			return;
142 		}
143 		break;
144 	case NDISC_REDIRECT:
145 		sctp_icmp_redirect(sk, t, skb);
146 		return;
147 	default:
148 		break;
149 	}
150 
151 	icmpv6_err_convert(type, code, &err);
152 	if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
153 		sk->sk_err = err;
154 		sk_error_report(sk);
155 	} else {
156 		WRITE_ONCE(sk->sk_err_soft, err);
157 	}
158 }
159 
160 /* ICMP error handler. */
sctp_v6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
162 		       u8 type, u8 code, int offset, __be32 info)
163 {
164 	struct net *net = dev_net(skb->dev);
165 	struct sctp_transport *transport;
166 	struct sctp_association *asoc;
167 	__u16 saveip, savesctp;
168 	struct sock *sk;
169 
170 	/* Fix up skb to look at the embedded net header. */
171 	saveip	 = skb->network_header;
172 	savesctp = skb->transport_header;
173 	skb_reset_network_header(skb);
174 	skb_set_transport_header(skb, offset);
175 	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
176 	/* Put back, the original pointers. */
177 	skb->network_header   = saveip;
178 	skb->transport_header = savesctp;
179 	if (!sk) {
180 		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
181 		return -ENOENT;
182 	}
183 
184 	sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
185 	sctp_err_finish(sk, transport);
186 
187 	return 0;
188 }
189 
sctp_udp_v6_err(struct sock * sk,struct sk_buff * skb)190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
191 {
192 	struct net *net = dev_net(skb->dev);
193 	struct sctp_association *asoc;
194 	struct sctp_transport *t;
195 	struct icmp6hdr *hdr;
196 	__u32 info = 0;
197 
198 	skb->transport_header += sizeof(struct udphdr);
199 	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
200 	if (!sk) {
201 		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
202 		return -ENOENT;
203 	}
204 
205 	skb->transport_header -= sizeof(struct udphdr);
206 	hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
207 	if (hdr->icmp6_type == NDISC_REDIRECT) {
208 		/* can't be handled without outer ip6hdr known, leave it to udpv6_err */
209 		sctp_err_finish(sk, t);
210 		return 0;
211 	}
212 	if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
213 		info = ntohl(hdr->icmp6_mtu);
214 	sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
215 
216 	sctp_err_finish(sk, t);
217 	return 1;
218 }
219 
sctp_v6_xmit(struct sk_buff * skb,struct sctp_transport * t)220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
221 {
222 	struct dst_entry *dst = dst_clone(t->dst);
223 	struct flowi6 *fl6 = &t->fl.u.ip6;
224 	struct sock *sk = skb->sk;
225 	struct ipv6_pinfo *np = inet6_sk(sk);
226 	__u8 tclass = np->tclass;
227 	__be32 label;
228 
229 	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
230 		 skb->len, &fl6->saddr, &fl6->daddr);
231 
232 	if (t->dscp & SCTP_DSCP_SET_MASK)
233 		tclass = t->dscp & SCTP_DSCP_VAL_MASK;
234 
235 	if (INET_ECN_is_capable(tclass))
236 		IP6_ECN_flow_xmit(sk, fl6->flowlabel);
237 
238 	if (!(t->param_flags & SPP_PMTUD_ENABLE))
239 		skb->ignore_df = 1;
240 
241 	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
242 
243 	if (!t->encap_port || !sctp_sk(sk)->udp_port) {
244 		int res;
245 
246 		skb_dst_set(skb, dst);
247 		rcu_read_lock();
248 		res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
249 			       rcu_dereference(np->opt),
250 			       tclass, READ_ONCE(sk->sk_priority));
251 		rcu_read_unlock();
252 		return res;
253 	}
254 
255 	if (skb_is_gso(skb))
256 		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
257 
258 	skb->encapsulation = 1;
259 	skb_reset_inner_mac_header(skb);
260 	skb_reset_inner_transport_header(skb);
261 	skb_set_inner_ipproto(skb, IPPROTO_SCTP);
262 	label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
263 
264 	return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
265 				    &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
266 				    label, sctp_sk(sk)->udp_port, t->encap_port, false);
267 }
268 
269 /* Returns the dst cache entry for the given source and destination ip
270  * addresses.
271  */
sctp_v6_get_dst(struct sctp_transport * t,union sctp_addr * saddr,struct flowi * fl,struct sock * sk)272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
273 			    struct flowi *fl, struct sock *sk)
274 {
275 	struct sctp_association *asoc = t->asoc;
276 	struct dst_entry *dst = NULL;
277 	struct flowi _fl;
278 	struct flowi6 *fl6 = &_fl.u.ip6;
279 	struct sctp_bind_addr *bp;
280 	struct ipv6_pinfo *np = inet6_sk(sk);
281 	struct sctp_sockaddr_entry *laddr;
282 	union sctp_addr *daddr = &t->ipaddr;
283 	union sctp_addr dst_saddr;
284 	struct in6_addr *final_p, final;
285 	enum sctp_scope scope;
286 	__u8 matchlen = 0;
287 
288 	memset(&_fl, 0, sizeof(_fl));
289 	fl6->daddr = daddr->v6.sin6_addr;
290 	fl6->fl6_dport = daddr->v6.sin6_port;
291 	fl6->flowi6_proto = IPPROTO_SCTP;
292 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
293 		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
294 	else if (asoc)
295 		fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
296 	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
297 		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
298 
299 	if (inet6_test_bit(SNDFLOW, sk) &&
300 	    (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
301 		struct ip6_flowlabel *flowlabel;
302 
303 		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
304 		if (IS_ERR(flowlabel))
305 			goto out;
306 		fl6_sock_release(flowlabel);
307 	}
308 
309 	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
310 
311 	if (asoc)
312 		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
313 
314 	if (saddr) {
315 		fl6->saddr = saddr->v6.sin6_addr;
316 		if (!fl6->fl6_sport)
317 			fl6->fl6_sport = saddr->v6.sin6_port;
318 
319 		pr_debug("src=%pI6 - ", &fl6->saddr);
320 	}
321 
322 	rcu_read_lock();
323 	final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
324 	rcu_read_unlock();
325 
326 	dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
327 	if (!asoc || saddr) {
328 		t->dst = dst;
329 		memcpy(fl, &_fl, sizeof(_fl));
330 		goto out;
331 	}
332 
333 	bp = &asoc->base.bind_addr;
334 	scope = sctp_scope(daddr);
335 	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
336 	 * to see if we can use it.
337 	 */
338 	if (!IS_ERR(dst)) {
339 		/* Walk through the bind address list and look for a bind
340 		 * address that matches the source address of the returned dst.
341 		 */
342 		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
343 		rcu_read_lock();
344 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
345 			if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
346 			    (laddr->state != SCTP_ADDR_SRC &&
347 			     !asoc->src_out_of_asoc_ok))
348 				continue;
349 
350 			/* Do not compare against v4 addrs */
351 			if ((laddr->a.sa.sa_family == AF_INET6) &&
352 			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
353 				rcu_read_unlock();
354 				t->dst = dst;
355 				memcpy(fl, &_fl, sizeof(_fl));
356 				goto out;
357 			}
358 		}
359 		rcu_read_unlock();
360 		/* None of the bound addresses match the source address of the
361 		 * dst. So release it.
362 		 */
363 		dst_release(dst);
364 		dst = NULL;
365 	}
366 
367 	/* Walk through the bind address list and try to get the
368 	 * best source address for a given destination.
369 	 */
370 	rcu_read_lock();
371 	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
372 		struct dst_entry *bdst;
373 		__u8 bmatchlen;
374 
375 		if (!laddr->valid ||
376 		    laddr->state != SCTP_ADDR_SRC ||
377 		    laddr->a.sa.sa_family != AF_INET6 ||
378 		    scope > sctp_scope(&laddr->a))
379 			continue;
380 
381 		fl6->saddr = laddr->a.v6.sin6_addr;
382 		fl6->fl6_sport = laddr->a.v6.sin6_port;
383 		final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
384 		bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
385 
386 		if (IS_ERR(bdst))
387 			continue;
388 
389 		if (ipv6_chk_addr(dev_net(bdst->dev),
390 				  &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
391 			if (!IS_ERR_OR_NULL(dst))
392 				dst_release(dst);
393 			dst = bdst;
394 			t->dst = dst;
395 			memcpy(fl, &_fl, sizeof(_fl));
396 			break;
397 		}
398 
399 		bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
400 		if (matchlen > bmatchlen) {
401 			dst_release(bdst);
402 			continue;
403 		}
404 
405 		if (!IS_ERR_OR_NULL(dst))
406 			dst_release(dst);
407 		dst = bdst;
408 		matchlen = bmatchlen;
409 		t->dst = dst;
410 		memcpy(fl, &_fl, sizeof(_fl));
411 	}
412 	rcu_read_unlock();
413 
414 out:
415 	if (!IS_ERR_OR_NULL(dst)) {
416 		struct rt6_info *rt;
417 
418 		rt = dst_rt6_info(dst);
419 		t->dst_cookie = rt6_get_cookie(rt);
420 		pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
421 			 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
422 			 &fl->u.ip6.saddr);
423 	} else {
424 		t->dst = NULL;
425 		pr_debug("no route\n");
426 	}
427 }
428 
429 /* Returns the number of consecutive initial bits that match in the 2 ipv6
430  * addresses.
431  */
sctp_v6_addr_match_len(union sctp_addr * s1,union sctp_addr * s2)432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
433 					 union sctp_addr *s2)
434 {
435 	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
436 }
437 
438 /* Fills in the source address(saddr) based on the destination address(daddr)
439  * and asoc's bind address list.
440  */
sctp_v6_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)441 static void sctp_v6_get_saddr(struct sctp_sock *sk,
442 			      struct sctp_transport *t,
443 			      struct flowi *fl)
444 {
445 	struct flowi6 *fl6 = &fl->u.ip6;
446 	union sctp_addr *saddr = &t->saddr;
447 
448 	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
449 
450 	if (t->dst) {
451 		saddr->v6.sin6_family = AF_INET6;
452 		saddr->v6.sin6_addr = fl6->saddr;
453 	}
454 }
455 
456 /* Make a copy of all potential local addresses. */
sctp_v6_copy_addrlist(struct list_head * addrlist,struct net_device * dev)457 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
458 				  struct net_device *dev)
459 {
460 	struct inet6_dev *in6_dev;
461 	struct inet6_ifaddr *ifp;
462 	struct sctp_sockaddr_entry *addr;
463 
464 	rcu_read_lock();
465 	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
466 		rcu_read_unlock();
467 		return;
468 	}
469 
470 	read_lock_bh(&in6_dev->lock);
471 	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
472 		/* Add the address to the local list.  */
473 		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
474 		if (addr) {
475 			addr->a.v6.sin6_family = AF_INET6;
476 			addr->a.v6.sin6_addr = ifp->addr;
477 			addr->a.v6.sin6_scope_id = dev->ifindex;
478 			addr->valid = 1;
479 			INIT_LIST_HEAD(&addr->list);
480 			list_add_tail(&addr->list, addrlist);
481 		}
482 	}
483 
484 	read_unlock_bh(&in6_dev->lock);
485 	rcu_read_unlock();
486 }
487 
488 /* Copy over any ip options */
sctp_v6_copy_ip_options(struct sock * sk,struct sock * newsk)489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
490 {
491 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
492 	struct ipv6_txoptions *opt;
493 
494 	newnp = inet6_sk(newsk);
495 
496 	rcu_read_lock();
497 	opt = rcu_dereference(np->opt);
498 	if (opt) {
499 		opt = ipv6_dup_options(newsk, opt);
500 		if (!opt)
501 			pr_err("%s: Failed to copy ip options\n", __func__);
502 	}
503 	RCU_INIT_POINTER(newnp->opt, opt);
504 	rcu_read_unlock();
505 }
506 
507 /* Account for the IP options */
sctp_v6_ip_options_len(struct sock * sk)508 static int sctp_v6_ip_options_len(struct sock *sk)
509 {
510 	struct ipv6_pinfo *np = inet6_sk(sk);
511 	struct ipv6_txoptions *opt;
512 	int len = 0;
513 
514 	rcu_read_lock();
515 	opt = rcu_dereference(np->opt);
516 	if (opt)
517 		len = opt->opt_flen + opt->opt_nflen;
518 
519 	rcu_read_unlock();
520 	return len;
521 }
522 
523 /* Initialize a sockaddr_storage from in incoming skb. */
sctp_v6_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
525 			     int is_saddr)
526 {
527 	/* Always called on head skb, so this is safe */
528 	struct sctphdr *sh = sctp_hdr(skb);
529 	struct sockaddr_in6 *sa = &addr->v6;
530 
531 	addr->v6.sin6_family = AF_INET6;
532 	addr->v6.sin6_flowinfo = 0; /* FIXME */
533 	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
534 
535 	if (is_saddr) {
536 		sa->sin6_port = sh->source;
537 		sa->sin6_addr = ipv6_hdr(skb)->saddr;
538 	} else {
539 		sa->sin6_port = sh->dest;
540 		sa->sin6_addr = ipv6_hdr(skb)->daddr;
541 	}
542 }
543 
544 /* Initialize an sctp_addr from a socket. */
sctp_v6_from_sk(union sctp_addr * addr,struct sock * sk)545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
546 {
547 	addr->v6.sin6_family = AF_INET6;
548 	addr->v6.sin6_port = 0;
549 	addr->v6.sin6_flowinfo = 0;
550 	addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
551 	addr->v6.sin6_scope_id = 0;
552 }
553 
554 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v6_to_sk_saddr(union sctp_addr * addr,struct sock * sk)555 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
556 {
557 	if (addr->sa.sa_family == AF_INET) {
558 		sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
559 		sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
560 		sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
561 		sk->sk_v6_rcv_saddr.s6_addr32[3] =
562 			addr->v4.sin_addr.s_addr;
563 	} else {
564 		sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
565 	}
566 }
567 
568 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v6_to_sk_daddr(union sctp_addr * addr,struct sock * sk)569 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
570 {
571 	if (addr->sa.sa_family == AF_INET) {
572 		sk->sk_v6_daddr.s6_addr32[0] = 0;
573 		sk->sk_v6_daddr.s6_addr32[1] = 0;
574 		sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
575 		sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
576 	} else {
577 		sk->sk_v6_daddr = addr->v6.sin6_addr;
578 	}
579 }
580 
581 /* Initialize a sctp_addr from an address parameter. */
sctp_v6_from_addr_param(union sctp_addr * addr,union sctp_addr_param * param,__be16 port,int iif)582 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
583 				    union sctp_addr_param *param,
584 				    __be16 port, int iif)
585 {
586 	if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
587 		return false;
588 
589 	addr->v6.sin6_family = AF_INET6;
590 	addr->v6.sin6_port = port;
591 	addr->v6.sin6_flowinfo = 0; /* BUG */
592 	addr->v6.sin6_addr = param->v6.addr;
593 	addr->v6.sin6_scope_id = iif;
594 
595 	return true;
596 }
597 
598 /* Initialize an address parameter from a sctp_addr and return the length
599  * of the address parameter.
600  */
sctp_v6_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)601 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
602 				 union sctp_addr_param *param)
603 {
604 	int length = sizeof(struct sctp_ipv6addr_param);
605 
606 	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
607 	param->v6.param_hdr.length = htons(length);
608 	param->v6.addr = addr->v6.sin6_addr;
609 
610 	return length;
611 }
612 
613 /* Initialize a sctp_addr from struct in6_addr. */
sctp_v6_to_addr(union sctp_addr * addr,struct in6_addr * saddr,__be16 port)614 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
615 			      __be16 port)
616 {
617 	addr->sa.sa_family = AF_INET6;
618 	addr->v6.sin6_port = port;
619 	addr->v6.sin6_flowinfo = 0;
620 	addr->v6.sin6_addr = *saddr;
621 	addr->v6.sin6_scope_id = 0;
622 }
623 
__sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)624 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
625 			      const union sctp_addr *addr2)
626 {
627 	if (addr1->sa.sa_family != addr2->sa.sa_family) {
628 		if (addr1->sa.sa_family == AF_INET &&
629 		    addr2->sa.sa_family == AF_INET6 &&
630 		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
631 		    addr2->v6.sin6_addr.s6_addr32[3] ==
632 		    addr1->v4.sin_addr.s_addr)
633 			return 1;
634 
635 		if (addr2->sa.sa_family == AF_INET &&
636 		    addr1->sa.sa_family == AF_INET6 &&
637 		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
638 		    addr1->v6.sin6_addr.s6_addr32[3] ==
639 		    addr2->v4.sin_addr.s_addr)
640 			return 1;
641 
642 		return 0;
643 	}
644 
645 	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
646 		return 0;
647 
648 	/* If this is a linklocal address, compare the scope_id. */
649 	if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
650 	    addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
651 	    addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
652 		return 0;
653 
654 	return 1;
655 }
656 
657 /* Compare addresses exactly.
658  * v4-mapped-v6 is also in consideration.
659  */
sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)660 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
661 			    const union sctp_addr *addr2)
662 {
663 	return __sctp_v6_cmp_addr(addr1, addr2) &&
664 	       addr1->v6.sin6_port == addr2->v6.sin6_port;
665 }
666 
667 /* Initialize addr struct to INADDR_ANY. */
sctp_v6_inaddr_any(union sctp_addr * addr,__be16 port)668 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
669 {
670 	memset(addr, 0x00, sizeof(union sctp_addr));
671 	addr->v6.sin6_family = AF_INET6;
672 	addr->v6.sin6_port = port;
673 }
674 
675 /* Is this a wildcard address? */
sctp_v6_is_any(const union sctp_addr * addr)676 static int sctp_v6_is_any(const union sctp_addr *addr)
677 {
678 	return ipv6_addr_any(&addr->v6.sin6_addr);
679 }
680 
681 /* Should this be available for binding?   */
sctp_v6_available(union sctp_addr * addr,struct sctp_sock * sp)682 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
683 {
684 	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
685 	struct sock *sk = &sp->inet.sk;
686 	struct net *net = sock_net(sk);
687 	struct net_device *dev = NULL;
688 	int type, res, bound_dev_if;
689 
690 	type = ipv6_addr_type(in6);
691 	if (IPV6_ADDR_ANY == type)
692 		return 1;
693 	if (type == IPV6_ADDR_MAPPED) {
694 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
695 			return 0;
696 		sctp_v6_map_v4(addr);
697 		return sctp_get_af_specific(AF_INET)->available(addr, sp);
698 	}
699 	if (!(type & IPV6_ADDR_UNICAST))
700 		return 0;
701 
702 	rcu_read_lock();
703 	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
704 	if (bound_dev_if) {
705 		res = 0;
706 		dev = dev_get_by_index_rcu(net, bound_dev_if);
707 		if (!dev)
708 			goto out;
709 	}
710 
711 	res = ipv6_can_nonlocal_bind(net, &sp->inet) ||
712 	      ipv6_chk_addr(net, in6, dev, 0);
713 
714 out:
715 	rcu_read_unlock();
716 	return res;
717 }
718 
719 /* This function checks if the address is a valid address to be used for
720  * SCTP.
721  *
722  * Output:
723  * Return 0 - If the address is a non-unicast or an illegal address.
724  * Return 1 - If the address is a unicast.
725  */
sctp_v6_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)726 static int sctp_v6_addr_valid(union sctp_addr *addr,
727 			      struct sctp_sock *sp,
728 			      const struct sk_buff *skb)
729 {
730 	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
731 
732 	/* Support v4-mapped-v6 address. */
733 	if (ret == IPV6_ADDR_MAPPED) {
734 		/* Note: This routine is used in input, so v4-mapped-v6
735 		 * are disallowed here when there is no sctp_sock.
736 		 */
737 		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
738 			return 0;
739 		sctp_v6_map_v4(addr);
740 		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
741 	}
742 
743 	/* Is this a non-unicast address */
744 	if (!(ret & IPV6_ADDR_UNICAST))
745 		return 0;
746 
747 	return 1;
748 }
749 
750 /* What is the scope of 'addr'?  */
sctp_v6_scope(union sctp_addr * addr)751 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
752 {
753 	enum sctp_scope retval;
754 	int v6scope;
755 
756 	/* The IPv6 scope is really a set of bit fields.
757 	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
758 	 */
759 
760 	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
761 	switch (v6scope) {
762 	case IFA_HOST:
763 		retval = SCTP_SCOPE_LOOPBACK;
764 		break;
765 	case IFA_LINK:
766 		retval = SCTP_SCOPE_LINK;
767 		break;
768 	case IFA_SITE:
769 		retval = SCTP_SCOPE_PRIVATE;
770 		break;
771 	default:
772 		retval = SCTP_SCOPE_GLOBAL;
773 		break;
774 	}
775 
776 	return retval;
777 }
778 
779 /* Create and initialize a new sk for the socket to be returned by accept(). */
sctp_v6_create_accept_sk(struct sock * sk,struct sctp_association * asoc,bool kern)780 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
781 					     struct sctp_association *asoc,
782 					     bool kern)
783 {
784 	struct sock *newsk;
785 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
786 	struct sctp6_sock *newsctp6sk;
787 
788 	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
789 	if (!newsk)
790 		goto out;
791 
792 	sock_init_data(NULL, newsk);
793 
794 	sctp_copy_sock(newsk, sk, asoc);
795 	sock_reset_flag(sk, SOCK_ZAPPED);
796 
797 	newsctp6sk = (struct sctp6_sock *)newsk;
798 	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
799 
800 	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
801 
802 	newnp = inet6_sk(newsk);
803 
804 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
805 	newnp->ipv6_mc_list = NULL;
806 	newnp->ipv6_ac_list = NULL;
807 	newnp->ipv6_fl_list = NULL;
808 
809 	sctp_v6_copy_ip_options(sk, newsk);
810 
811 	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
812 	 * and getpeername().
813 	 */
814 	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
815 
816 	newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
817 
818 	if (newsk->sk_prot->init(newsk)) {
819 		sk_common_release(newsk);
820 		newsk = NULL;
821 	}
822 
823 out:
824 	return newsk;
825 }
826 
827 /* Format a sockaddr for return to user space. This makes sure the return is
828  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
829  */
sctp_v6_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)830 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
831 {
832 	if (sp->v4mapped) {
833 		if (addr->sa.sa_family == AF_INET)
834 			sctp_v4_map_v6(addr);
835 	} else {
836 		if (addr->sa.sa_family == AF_INET6 &&
837 		    ipv6_addr_v4mapped(&addr->v6.sin6_addr))
838 			sctp_v6_map_v4(addr);
839 	}
840 
841 	if (addr->sa.sa_family == AF_INET) {
842 		memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
843 		return sizeof(struct sockaddr_in);
844 	}
845 	return sizeof(struct sockaddr_in6);
846 }
847 
848 /* Where did this skb come from?  */
sctp_v6_skb_iif(const struct sk_buff * skb)849 static int sctp_v6_skb_iif(const struct sk_buff *skb)
850 {
851 	return inet6_iif(skb);
852 }
853 
sctp_v6_skb_sdif(const struct sk_buff * skb)854 static int sctp_v6_skb_sdif(const struct sk_buff *skb)
855 {
856 	return inet6_sdif(skb);
857 }
858 
859 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v6_is_ce(const struct sk_buff * skb)860 static int sctp_v6_is_ce(const struct sk_buff *skb)
861 {
862 	return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
863 }
864 
865 /* Dump the v6 addr to the seq file. */
sctp_v6_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)866 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
867 {
868 	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
869 }
870 
sctp_v6_ecn_capable(struct sock * sk)871 static void sctp_v6_ecn_capable(struct sock *sk)
872 {
873 	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
874 }
875 
876 /* Initialize a PF_INET msgname from a ulpevent. */
sctp_inet6_event_msgname(struct sctp_ulpevent * event,char * msgname,int * addrlen)877 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
878 				     char *msgname, int *addrlen)
879 {
880 	union sctp_addr *addr;
881 	struct sctp_association *asoc;
882 	union sctp_addr *paddr;
883 
884 	if (!msgname)
885 		return;
886 
887 	addr = (union sctp_addr *)msgname;
888 	asoc = event->asoc;
889 	paddr = &asoc->peer.primary_addr;
890 
891 	if (paddr->sa.sa_family == AF_INET) {
892 		addr->v4.sin_family = AF_INET;
893 		addr->v4.sin_port = htons(asoc->peer.port);
894 		addr->v4.sin_addr = paddr->v4.sin_addr;
895 	} else {
896 		addr->v6.sin6_family = AF_INET6;
897 		addr->v6.sin6_flowinfo = 0;
898 		if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
899 			addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
900 		else
901 			addr->v6.sin6_scope_id = 0;
902 		addr->v6.sin6_port = htons(asoc->peer.port);
903 		addr->v6.sin6_addr = paddr->v6.sin6_addr;
904 	}
905 
906 	*addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
907 }
908 
909 /* Initialize a msg_name from an inbound skb. */
sctp_inet6_skb_msgname(struct sk_buff * skb,char * msgname,int * addr_len)910 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
911 				   int *addr_len)
912 {
913 	union sctp_addr *addr;
914 	struct sctphdr *sh;
915 
916 	if (!msgname)
917 		return;
918 
919 	addr = (union sctp_addr *)msgname;
920 	sh = sctp_hdr(skb);
921 
922 	if (ip_hdr(skb)->version == 4) {
923 		addr->v4.sin_family = AF_INET;
924 		addr->v4.sin_port = sh->source;
925 		addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
926 	} else {
927 		addr->v6.sin6_family = AF_INET6;
928 		addr->v6.sin6_flowinfo = 0;
929 		addr->v6.sin6_port = sh->source;
930 		addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
931 		if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
932 			addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
933 		else
934 			addr->v6.sin6_scope_id = 0;
935 	}
936 
937 	*addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
938 }
939 
940 /* Do we support this AF? */
sctp_inet6_af_supported(sa_family_t family,struct sctp_sock * sp)941 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
942 {
943 	switch (family) {
944 	case AF_INET6:
945 		return 1;
946 	/* v4-mapped-v6 addresses */
947 	case AF_INET:
948 		if (!ipv6_only_sock(sctp_opt2sk(sp)))
949 			return 1;
950 		fallthrough;
951 	default:
952 		return 0;
953 	}
954 }
955 
956 /* Address matching with wildcards allowed.  This extra level
957  * of indirection lets us choose whether a PF_INET6 should
958  * disallow any v4 addresses if we so choose.
959  */
sctp_inet6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)960 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
961 			       const union sctp_addr *addr2,
962 			       struct sctp_sock *opt)
963 {
964 	struct sock *sk = sctp_opt2sk(opt);
965 	struct sctp_af *af1, *af2;
966 
967 	af1 = sctp_get_af_specific(addr1->sa.sa_family);
968 	af2 = sctp_get_af_specific(addr2->sa.sa_family);
969 
970 	if (!af1 || !af2)
971 		return 0;
972 
973 	/* If the socket is IPv6 only, v4 addrs will not match */
974 	if (ipv6_only_sock(sk) && af1 != af2)
975 		return 0;
976 
977 	/* Today, wildcard AF_INET/AF_INET6. */
978 	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
979 		return 1;
980 
981 	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
982 		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
983 
984 	return __sctp_v6_cmp_addr(addr1, addr2);
985 }
986 
987 /* Verify that the provided sockaddr looks bindable.   Common verification,
988  * has already been taken care of.
989  */
sctp_inet6_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)990 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
991 {
992 	struct sctp_af *af;
993 
994 	/* ASSERT: address family has already been verified. */
995 	if (addr->sa.sa_family != AF_INET6)
996 		af = sctp_get_af_specific(addr->sa.sa_family);
997 	else {
998 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
999 		struct net_device *dev;
1000 
1001 		if (type & IPV6_ADDR_LINKLOCAL) {
1002 			struct net *net;
1003 			if (!addr->v6.sin6_scope_id)
1004 				return 0;
1005 			net = sock_net(&opt->inet.sk);
1006 			rcu_read_lock();
1007 			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
1008 			if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
1009 				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
1010 						    dev, 0))) {
1011 				rcu_read_unlock();
1012 				return 0;
1013 			}
1014 			rcu_read_unlock();
1015 		}
1016 
1017 		af = opt->pf->af;
1018 	}
1019 	return af->available(addr, opt);
1020 }
1021 
1022 /* Verify that the provided sockaddr looks sendable.   Common verification,
1023  * has already been taken care of.
1024  */
sctp_inet6_send_verify(struct sctp_sock * opt,union sctp_addr * addr)1025 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1026 {
1027 	struct sctp_af *af = NULL;
1028 
1029 	/* ASSERT: address family has already been verified. */
1030 	if (addr->sa.sa_family != AF_INET6)
1031 		af = sctp_get_af_specific(addr->sa.sa_family);
1032 	else {
1033 		int type = ipv6_addr_type(&addr->v6.sin6_addr);
1034 		struct net_device *dev;
1035 
1036 		if (type & IPV6_ADDR_LINKLOCAL) {
1037 			if (!addr->v6.sin6_scope_id)
1038 				return 0;
1039 			rcu_read_lock();
1040 			dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1041 						   addr->v6.sin6_scope_id);
1042 			rcu_read_unlock();
1043 			if (!dev)
1044 				return 0;
1045 		}
1046 		af = opt->pf->af;
1047 	}
1048 
1049 	return af != NULL;
1050 }
1051 
1052 /* Fill in Supported Address Type information for INIT and INIT-ACK
1053  * chunks.   Note: In the future, we may want to look at sock options
1054  * to determine whether a PF_INET6 socket really wants to have IPV4
1055  * addresses.
1056  * Returns number of addresses supported.
1057  */
sctp_inet6_supported_addrs(const struct sctp_sock * opt,__be16 * types)1058 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1059 				      __be16 *types)
1060 {
1061 	types[0] = SCTP_PARAM_IPV6_ADDRESS;
1062 	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1063 		types[1] = SCTP_PARAM_IPV4_ADDRESS;
1064 		return 2;
1065 	}
1066 	return 1;
1067 }
1068 
1069 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
sctp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)1070 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1071 			int peer)
1072 {
1073 	int rc;
1074 
1075 	rc = inet6_getname(sock, uaddr, peer);
1076 
1077 	if (rc < 0)
1078 		return rc;
1079 
1080 	rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1081 					  (union sctp_addr *)uaddr);
1082 
1083 	return rc;
1084 }
1085 
1086 static const struct proto_ops inet6_seqpacket_ops = {
1087 	.family		   = PF_INET6,
1088 	.owner		   = THIS_MODULE,
1089 	.release	   = inet6_release,
1090 	.bind		   = inet6_bind,
1091 	.connect	   = sctp_inet_connect,
1092 	.socketpair	   = sock_no_socketpair,
1093 	.accept		   = inet_accept,
1094 	.getname	   = sctp_getname,
1095 	.poll		   = sctp_poll,
1096 	.ioctl		   = inet6_ioctl,
1097 	.gettstamp	   = sock_gettstamp,
1098 	.listen		   = sctp_inet_listen,
1099 	.shutdown	   = inet_shutdown,
1100 	.setsockopt	   = sock_common_setsockopt,
1101 	.getsockopt	   = sock_common_getsockopt,
1102 	.sendmsg	   = inet_sendmsg,
1103 	.recvmsg	   = inet_recvmsg,
1104 	.mmap		   = sock_no_mmap,
1105 #ifdef CONFIG_COMPAT
1106 	.compat_ioctl	   = inet6_compat_ioctl,
1107 #endif
1108 };
1109 
1110 static struct inet_protosw sctpv6_seqpacket_protosw = {
1111 	.type          = SOCK_SEQPACKET,
1112 	.protocol      = IPPROTO_SCTP,
1113 	.prot 	       = &sctpv6_prot,
1114 	.ops           = &inet6_seqpacket_ops,
1115 	.flags         = SCTP_PROTOSW_FLAG
1116 };
1117 static struct inet_protosw sctpv6_stream_protosw = {
1118 	.type          = SOCK_STREAM,
1119 	.protocol      = IPPROTO_SCTP,
1120 	.prot 	       = &sctpv6_prot,
1121 	.ops           = &inet6_seqpacket_ops,
1122 	.flags         = SCTP_PROTOSW_FLAG,
1123 };
1124 
sctp6_rcv(struct sk_buff * skb)1125 static int sctp6_rcv(struct sk_buff *skb)
1126 {
1127 	SCTP_INPUT_CB(skb)->encap_port = 0;
1128 	return sctp_rcv(skb) ? -1 : 0;
1129 }
1130 
1131 static const struct inet6_protocol sctpv6_protocol = {
1132 	.handler      = sctp6_rcv,
1133 	.err_handler  = sctp_v6_err,
1134 	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1135 };
1136 
1137 static struct sctp_af sctp_af_inet6 = {
1138 	.sa_family	   = AF_INET6,
1139 	.sctp_xmit	   = sctp_v6_xmit,
1140 	.setsockopt	   = ipv6_setsockopt,
1141 	.getsockopt	   = ipv6_getsockopt,
1142 	.get_dst	   = sctp_v6_get_dst,
1143 	.get_saddr	   = sctp_v6_get_saddr,
1144 	.copy_addrlist	   = sctp_v6_copy_addrlist,
1145 	.from_skb	   = sctp_v6_from_skb,
1146 	.from_sk	   = sctp_v6_from_sk,
1147 	.from_addr_param   = sctp_v6_from_addr_param,
1148 	.to_addr_param	   = sctp_v6_to_addr_param,
1149 	.cmp_addr	   = sctp_v6_cmp_addr,
1150 	.scope		   = sctp_v6_scope,
1151 	.addr_valid	   = sctp_v6_addr_valid,
1152 	.inaddr_any	   = sctp_v6_inaddr_any,
1153 	.is_any		   = sctp_v6_is_any,
1154 	.available	   = sctp_v6_available,
1155 	.skb_iif	   = sctp_v6_skb_iif,
1156 	.skb_sdif	   = sctp_v6_skb_sdif,
1157 	.is_ce		   = sctp_v6_is_ce,
1158 	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
1159 	.ecn_capable	   = sctp_v6_ecn_capable,
1160 	.net_header_len	   = sizeof(struct ipv6hdr),
1161 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1162 	.ip_options_len	   = sctp_v6_ip_options_len,
1163 };
1164 
1165 static struct sctp_pf sctp_pf_inet6 = {
1166 	.event_msgname = sctp_inet6_event_msgname,
1167 	.skb_msgname   = sctp_inet6_skb_msgname,
1168 	.af_supported  = sctp_inet6_af_supported,
1169 	.cmp_addr      = sctp_inet6_cmp_addr,
1170 	.bind_verify   = sctp_inet6_bind_verify,
1171 	.send_verify   = sctp_inet6_send_verify,
1172 	.supported_addrs = sctp_inet6_supported_addrs,
1173 	.create_accept_sk = sctp_v6_create_accept_sk,
1174 	.addr_to_user  = sctp_v6_addr_to_user,
1175 	.to_sk_saddr   = sctp_v6_to_sk_saddr,
1176 	.to_sk_daddr   = sctp_v6_to_sk_daddr,
1177 	.copy_ip_options = sctp_v6_copy_ip_options,
1178 	.af            = &sctp_af_inet6,
1179 };
1180 
1181 /* Initialize IPv6 support and register with socket layer.  */
sctp_v6_pf_init(void)1182 void sctp_v6_pf_init(void)
1183 {
1184 	/* Register the SCTP specific PF_INET6 functions. */
1185 	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1186 
1187 	/* Register the SCTP specific AF_INET6 functions. */
1188 	sctp_register_af(&sctp_af_inet6);
1189 }
1190 
sctp_v6_pf_exit(void)1191 void sctp_v6_pf_exit(void)
1192 {
1193 	list_del(&sctp_af_inet6.list);
1194 }
1195 
1196 /* Initialize IPv6 support and register with socket layer.  */
sctp_v6_protosw_init(void)1197 int sctp_v6_protosw_init(void)
1198 {
1199 	int rc;
1200 
1201 	rc = proto_register(&sctpv6_prot, 1);
1202 	if (rc)
1203 		return rc;
1204 
1205 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1206 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1207 	inet6_register_protosw(&sctpv6_stream_protosw);
1208 
1209 	return 0;
1210 }
1211 
sctp_v6_protosw_exit(void)1212 void sctp_v6_protosw_exit(void)
1213 {
1214 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1215 	inet6_unregister_protosw(&sctpv6_stream_protosw);
1216 	proto_unregister(&sctpv6_prot);
1217 }
1218 
1219 
1220 /* Register with inet6 layer. */
sctp_v6_add_protocol(void)1221 int sctp_v6_add_protocol(void)
1222 {
1223 	/* Register notifier for inet6 address additions/deletions. */
1224 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1225 
1226 	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1227 		return -EAGAIN;
1228 
1229 	return 0;
1230 }
1231 
1232 /* Unregister with inet6 layer. */
sctp_v6_del_protocol(void)1233 void sctp_v6_del_protocol(void)
1234 {
1235 	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1236 	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1237 }
1238