xref: /openbmc/linux/net/ipv6/af_inet6.c (revision fd589a8f)
1 /*
2  *	PF_INET6 socket protocol family
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  *
8  *	Adapted from linux/net/ipv4/af_inet.c
9  *
10  * 	Fixes:
11  *	piggy, Karl Knutson	:	Socket protocol table
12  * 	Hideaki YOSHIFUJI	:	sin6_scope_id support
13  * 	Arnaldo Melo		: 	check proc_net_create return, cleanups
14  *
15  *	This program is free software; you can redistribute it and/or
16  *      modify it under the terms of the GNU General Public License
17  *      as published by the Free Software Foundation; either version
18  *      2 of the License, or (at your option) any later version.
19  */
20 
21 
22 #include <linux/module.h>
23 #include <linux/capability.h>
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/in.h>
28 #include <linux/kernel.h>
29 #include <linux/timer.h>
30 #include <linux/string.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/fcntl.h>
34 #include <linux/mm.h>
35 #include <linux/interrupt.h>
36 #include <linux/proc_fs.h>
37 #include <linux/stat.h>
38 #include <linux/init.h>
39 
40 #include <linux/inet.h>
41 #include <linux/netdevice.h>
42 #include <linux/icmpv6.h>
43 #include <linux/netfilter_ipv6.h>
44 
45 #include <net/ip.h>
46 #include <net/ipv6.h>
47 #include <net/udp.h>
48 #include <net/udplite.h>
49 #include <net/tcp.h>
50 #include <net/ipip.h>
51 #include <net/protocol.h>
52 #include <net/inet_common.h>
53 #include <net/route.h>
54 #include <net/transp_v6.h>
55 #include <net/ip6_route.h>
56 #include <net/addrconf.h>
57 #ifdef CONFIG_IPV6_TUNNEL
58 #include <net/ip6_tunnel.h>
59 #endif
60 
61 #include <asm/uaccess.h>
62 #include <asm/system.h>
63 #include <linux/mroute6.h>
64 
65 MODULE_AUTHOR("Cast of dozens");
66 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
67 MODULE_LICENSE("GPL");
68 
69 /* The inetsw6 table contains everything that inet6_create needs to
70  * build a new socket.
71  */
72 static struct list_head inetsw6[SOCK_MAX];
73 static DEFINE_SPINLOCK(inetsw6_lock);
74 
75 struct ipv6_params ipv6_defaults = {
76 	.disable_ipv6 = 0,
77 	.autoconf = 1,
78 };
79 
80 static int disable_ipv6_mod = 0;
81 
82 module_param_named(disable, disable_ipv6_mod, int, 0444);
83 MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
84 
85 module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
86 MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
87 
88 module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
89 MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");
90 
91 static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
92 {
93 	const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
94 
95 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
96 }
97 
98 static int inet6_create(struct net *net, struct socket *sock, int protocol)
99 {
100 	struct inet_sock *inet;
101 	struct ipv6_pinfo *np;
102 	struct sock *sk;
103 	struct inet_protosw *answer;
104 	struct proto *answer_prot;
105 	unsigned char answer_flags;
106 	char answer_no_check;
107 	int try_loading_module = 0;
108 	int err;
109 
110 	if (sock->type != SOCK_RAW &&
111 	    sock->type != SOCK_DGRAM &&
112 	    !inet_ehash_secret)
113 		build_ehash_secret();
114 
115 	/* Look for the requested type/protocol pair. */
116 lookup_protocol:
117 	err = -ESOCKTNOSUPPORT;
118 	rcu_read_lock();
119 	list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
120 
121 		err = 0;
122 		/* Check the non-wild match. */
123 		if (protocol == answer->protocol) {
124 			if (protocol != IPPROTO_IP)
125 				break;
126 		} else {
127 			/* Check for the two wild cases. */
128 			if (IPPROTO_IP == protocol) {
129 				protocol = answer->protocol;
130 				break;
131 			}
132 			if (IPPROTO_IP == answer->protocol)
133 				break;
134 		}
135 		err = -EPROTONOSUPPORT;
136 	}
137 
138 	if (err) {
139 		if (try_loading_module < 2) {
140 			rcu_read_unlock();
141 			/*
142 			 * Be more specific, e.g. net-pf-10-proto-132-type-1
143 			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
144 			 */
145 			if (++try_loading_module == 1)
146 				request_module("net-pf-%d-proto-%d-type-%d",
147 						PF_INET6, protocol, sock->type);
148 			/*
149 			 * Fall back to generic, e.g. net-pf-10-proto-132
150 			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
151 			 */
152 			else
153 				request_module("net-pf-%d-proto-%d",
154 						PF_INET6, protocol);
155 			goto lookup_protocol;
156 		} else
157 			goto out_rcu_unlock;
158 	}
159 
160 	err = -EPERM;
161 	if (answer->capability > 0 && !capable(answer->capability))
162 		goto out_rcu_unlock;
163 
164 	sock->ops = answer->ops;
165 	answer_prot = answer->prot;
166 	answer_no_check = answer->no_check;
167 	answer_flags = answer->flags;
168 	rcu_read_unlock();
169 
170 	WARN_ON(answer_prot->slab == NULL);
171 
172 	err = -ENOBUFS;
173 	sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot);
174 	if (sk == NULL)
175 		goto out;
176 
177 	sock_init_data(sock, sk);
178 
179 	err = 0;
180 	sk->sk_no_check = answer_no_check;
181 	if (INET_PROTOSW_REUSE & answer_flags)
182 		sk->sk_reuse = 1;
183 
184 	inet = inet_sk(sk);
185 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
186 
187 	if (SOCK_RAW == sock->type) {
188 		inet->num = protocol;
189 		if (IPPROTO_RAW == protocol)
190 			inet->hdrincl = 1;
191 	}
192 
193 	sk->sk_destruct		= inet_sock_destruct;
194 	sk->sk_family		= PF_INET6;
195 	sk->sk_protocol		= protocol;
196 
197 	sk->sk_backlog_rcv	= answer->prot->backlog_rcv;
198 
199 	inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
200 	np->hop_limit	= -1;
201 	np->mcast_hops	= -1;
202 	np->mc_loop	= 1;
203 	np->pmtudisc	= IPV6_PMTUDISC_WANT;
204 	np->ipv6only	= net->ipv6.sysctl.bindv6only;
205 
206 	/* Init the ipv4 part of the socket since we can have sockets
207 	 * using v6 API for ipv4.
208 	 */
209 	inet->uc_ttl	= -1;
210 
211 	inet->mc_loop	= 1;
212 	inet->mc_ttl	= 1;
213 	inet->mc_index	= 0;
214 	inet->mc_list	= NULL;
215 
216 	if (ipv4_config.no_pmtu_disc)
217 		inet->pmtudisc = IP_PMTUDISC_DONT;
218 	else
219 		inet->pmtudisc = IP_PMTUDISC_WANT;
220 	/*
221 	 * Increment only the relevant sk_prot->socks debug field, this changes
222 	 * the previous behaviour of incrementing both the equivalent to
223 	 * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
224 	 *
225 	 * This allows better debug granularity as we'll know exactly how many
226 	 * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
227 	 * transport protocol socks. -acme
228 	 */
229 	sk_refcnt_debug_inc(sk);
230 
231 	if (inet->num) {
232 		/* It assumes that any protocol which allows
233 		 * the user to assign a number at socket
234 		 * creation time automatically shares.
235 		 */
236 		inet->sport = htons(inet->num);
237 		sk->sk_prot->hash(sk);
238 	}
239 	if (sk->sk_prot->init) {
240 		err = sk->sk_prot->init(sk);
241 		if (err) {
242 			sk_common_release(sk);
243 			goto out;
244 		}
245 	}
246 out:
247 	return err;
248 out_rcu_unlock:
249 	rcu_read_unlock();
250 	goto out;
251 }
252 
253 
254 /* bind for INET6 API */
255 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
256 {
257 	struct sockaddr_in6 *addr=(struct sockaddr_in6 *)uaddr;
258 	struct sock *sk = sock->sk;
259 	struct inet_sock *inet = inet_sk(sk);
260 	struct ipv6_pinfo *np = inet6_sk(sk);
261 	struct net *net = sock_net(sk);
262 	__be32 v4addr = 0;
263 	unsigned short snum;
264 	int addr_type = 0;
265 	int err = 0;
266 
267 	/* If the socket has its own bind function then use it. */
268 	if (sk->sk_prot->bind)
269 		return sk->sk_prot->bind(sk, uaddr, addr_len);
270 
271 	if (addr_len < SIN6_LEN_RFC2133)
272 		return -EINVAL;
273 	addr_type = ipv6_addr_type(&addr->sin6_addr);
274 	if ((addr_type & IPV6_ADDR_MULTICAST) && sock->type == SOCK_STREAM)
275 		return -EINVAL;
276 
277 	snum = ntohs(addr->sin6_port);
278 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
279 		return -EACCES;
280 
281 	lock_sock(sk);
282 
283 	/* Check these errors (active socket, double bind). */
284 	if (sk->sk_state != TCP_CLOSE || inet->num) {
285 		err = -EINVAL;
286 		goto out;
287 	}
288 
289 	/* Check if the address belongs to the host. */
290 	if (addr_type == IPV6_ADDR_MAPPED) {
291 		int chk_addr_ret;
292 
293 		/* Binding to v4-mapped address on a v6-only socket
294 		 * makes no sense
295 		 */
296 		if (np->ipv6only) {
297 			err = -EINVAL;
298 			goto out;
299 		}
300 
301 		/* Reproduce AF_INET checks to make the bindings consitant */
302 		v4addr = addr->sin6_addr.s6_addr32[3];
303 		chk_addr_ret = inet_addr_type(net, v4addr);
304 		if (!sysctl_ip_nonlocal_bind &&
305 		    !(inet->freebind || inet->transparent) &&
306 		    v4addr != htonl(INADDR_ANY) &&
307 		    chk_addr_ret != RTN_LOCAL &&
308 		    chk_addr_ret != RTN_MULTICAST &&
309 		    chk_addr_ret != RTN_BROADCAST) {
310 			err = -EADDRNOTAVAIL;
311 			goto out;
312 		}
313 	} else {
314 		if (addr_type != IPV6_ADDR_ANY) {
315 			struct net_device *dev = NULL;
316 
317 			if (addr_type & IPV6_ADDR_LINKLOCAL) {
318 				if (addr_len >= sizeof(struct sockaddr_in6) &&
319 				    addr->sin6_scope_id) {
320 					/* Override any existing binding, if another one
321 					 * is supplied by user.
322 					 */
323 					sk->sk_bound_dev_if = addr->sin6_scope_id;
324 				}
325 
326 				/* Binding to link-local address requires an interface */
327 				if (!sk->sk_bound_dev_if) {
328 					err = -EINVAL;
329 					goto out;
330 				}
331 				dev = dev_get_by_index(net, sk->sk_bound_dev_if);
332 				if (!dev) {
333 					err = -ENODEV;
334 					goto out;
335 				}
336 			}
337 
338 			/* ipv4 addr of the socket is invalid.  Only the
339 			 * unspecified and mapped address have a v4 equivalent.
340 			 */
341 			v4addr = LOOPBACK4_IPV6;
342 			if (!(addr_type & IPV6_ADDR_MULTICAST))	{
343 				if (!ipv6_chk_addr(net, &addr->sin6_addr,
344 						   dev, 0)) {
345 					if (dev)
346 						dev_put(dev);
347 					err = -EADDRNOTAVAIL;
348 					goto out;
349 				}
350 			}
351 			if (dev)
352 				dev_put(dev);
353 		}
354 	}
355 
356 	inet->rcv_saddr = v4addr;
357 	inet->saddr = v4addr;
358 
359 	ipv6_addr_copy(&np->rcv_saddr, &addr->sin6_addr);
360 
361 	if (!(addr_type & IPV6_ADDR_MULTICAST))
362 		ipv6_addr_copy(&np->saddr, &addr->sin6_addr);
363 
364 	/* Make sure we are allowed to bind here. */
365 	if (sk->sk_prot->get_port(sk, snum)) {
366 		inet_reset_saddr(sk);
367 		err = -EADDRINUSE;
368 		goto out;
369 	}
370 
371 	if (addr_type != IPV6_ADDR_ANY) {
372 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
373 		if (addr_type != IPV6_ADDR_MAPPED)
374 			np->ipv6only = 1;
375 	}
376 	if (snum)
377 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
378 	inet->sport = htons(inet->num);
379 	inet->dport = 0;
380 	inet->daddr = 0;
381 out:
382 	release_sock(sk);
383 	return err;
384 }
385 
386 EXPORT_SYMBOL(inet6_bind);
387 
388 int inet6_release(struct socket *sock)
389 {
390 	struct sock *sk = sock->sk;
391 
392 	if (sk == NULL)
393 		return -EINVAL;
394 
395 	/* Free mc lists */
396 	ipv6_sock_mc_close(sk);
397 
398 	/* Free ac lists */
399 	ipv6_sock_ac_close(sk);
400 
401 	return inet_release(sock);
402 }
403 
404 EXPORT_SYMBOL(inet6_release);
405 
406 void inet6_destroy_sock(struct sock *sk)
407 {
408 	struct ipv6_pinfo *np = inet6_sk(sk);
409 	struct sk_buff *skb;
410 	struct ipv6_txoptions *opt;
411 
412 	/* Release rx options */
413 
414 	if ((skb = xchg(&np->pktoptions, NULL)) != NULL)
415 		kfree_skb(skb);
416 
417 	/* Free flowlabels */
418 	fl6_free_socklist(sk);
419 
420 	/* Free tx options */
421 
422 	if ((opt = xchg(&np->opt, NULL)) != NULL)
423 		sock_kfree_s(sk, opt, opt->tot_len);
424 }
425 
426 EXPORT_SYMBOL_GPL(inet6_destroy_sock);
427 
428 /*
429  *	This does both peername and sockname.
430  */
431 
432 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
433 		 int *uaddr_len, int peer)
434 {
435 	struct sockaddr_in6 *sin=(struct sockaddr_in6 *)uaddr;
436 	struct sock *sk = sock->sk;
437 	struct inet_sock *inet = inet_sk(sk);
438 	struct ipv6_pinfo *np = inet6_sk(sk);
439 
440 	sin->sin6_family = AF_INET6;
441 	sin->sin6_flowinfo = 0;
442 	sin->sin6_scope_id = 0;
443 	if (peer) {
444 		if (!inet->dport)
445 			return -ENOTCONN;
446 		if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
447 		    peer == 1)
448 			return -ENOTCONN;
449 		sin->sin6_port = inet->dport;
450 		ipv6_addr_copy(&sin->sin6_addr, &np->daddr);
451 		if (np->sndflow)
452 			sin->sin6_flowinfo = np->flow_label;
453 	} else {
454 		if (ipv6_addr_any(&np->rcv_saddr))
455 			ipv6_addr_copy(&sin->sin6_addr, &np->saddr);
456 		else
457 			ipv6_addr_copy(&sin->sin6_addr, &np->rcv_saddr);
458 
459 		sin->sin6_port = inet->sport;
460 	}
461 	if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
462 		sin->sin6_scope_id = sk->sk_bound_dev_if;
463 	*uaddr_len = sizeof(*sin);
464 	return(0);
465 }
466 
467 EXPORT_SYMBOL(inet6_getname);
468 
469 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
470 {
471 	struct sock *sk = sock->sk;
472 	struct net *net = sock_net(sk);
473 
474 	switch(cmd)
475 	{
476 	case SIOCGSTAMP:
477 		return sock_get_timestamp(sk, (struct timeval __user *)arg);
478 
479 	case SIOCGSTAMPNS:
480 		return sock_get_timestampns(sk, (struct timespec __user *)arg);
481 
482 	case SIOCADDRT:
483 	case SIOCDELRT:
484 
485 		return(ipv6_route_ioctl(net, cmd, (void __user *)arg));
486 
487 	case SIOCSIFADDR:
488 		return addrconf_add_ifaddr(net, (void __user *) arg);
489 	case SIOCDIFADDR:
490 		return addrconf_del_ifaddr(net, (void __user *) arg);
491 	case SIOCSIFDSTADDR:
492 		return addrconf_set_dstaddr(net, (void __user *) arg);
493 	default:
494 		if (!sk->sk_prot->ioctl)
495 			return -ENOIOCTLCMD;
496 		return sk->sk_prot->ioctl(sk, cmd, arg);
497 	}
498 	/*NOTREACHED*/
499 	return(0);
500 }
501 
502 EXPORT_SYMBOL(inet6_ioctl);
503 
504 const struct proto_ops inet6_stream_ops = {
505 	.family		   = PF_INET6,
506 	.owner		   = THIS_MODULE,
507 	.release	   = inet6_release,
508 	.bind		   = inet6_bind,
509 	.connect	   = inet_stream_connect,	/* ok		*/
510 	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
511 	.accept		   = inet_accept,		/* ok		*/
512 	.getname	   = inet6_getname,
513 	.poll		   = tcp_poll,			/* ok		*/
514 	.ioctl		   = inet6_ioctl,		/* must change  */
515 	.listen		   = inet_listen,		/* ok		*/
516 	.shutdown	   = inet_shutdown,		/* ok		*/
517 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
518 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
519 	.sendmsg	   = tcp_sendmsg,		/* ok		*/
520 	.recvmsg	   = sock_common_recvmsg,	/* ok		*/
521 	.mmap		   = sock_no_mmap,
522 	.sendpage	   = tcp_sendpage,
523 	.splice_read	   = tcp_splice_read,
524 #ifdef CONFIG_COMPAT
525 	.compat_setsockopt = compat_sock_common_setsockopt,
526 	.compat_getsockopt = compat_sock_common_getsockopt,
527 #endif
528 };
529 
530 const struct proto_ops inet6_dgram_ops = {
531 	.family		   = PF_INET6,
532 	.owner		   = THIS_MODULE,
533 	.release	   = inet6_release,
534 	.bind		   = inet6_bind,
535 	.connect	   = inet_dgram_connect,	/* ok		*/
536 	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
537 	.accept		   = sock_no_accept,		/* a do nothing	*/
538 	.getname	   = inet6_getname,
539 	.poll		   = udp_poll,			/* ok		*/
540 	.ioctl		   = inet6_ioctl,		/* must change  */
541 	.listen		   = sock_no_listen,		/* ok		*/
542 	.shutdown	   = inet_shutdown,		/* ok		*/
543 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
544 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
545 	.sendmsg	   = inet_sendmsg,		/* ok		*/
546 	.recvmsg	   = sock_common_recvmsg,	/* ok		*/
547 	.mmap		   = sock_no_mmap,
548 	.sendpage	   = sock_no_sendpage,
549 #ifdef CONFIG_COMPAT
550 	.compat_setsockopt = compat_sock_common_setsockopt,
551 	.compat_getsockopt = compat_sock_common_getsockopt,
552 #endif
553 };
554 
555 static struct net_proto_family inet6_family_ops = {
556 	.family = PF_INET6,
557 	.create = inet6_create,
558 	.owner	= THIS_MODULE,
559 };
560 
561 int inet6_register_protosw(struct inet_protosw *p)
562 {
563 	struct list_head *lh;
564 	struct inet_protosw *answer;
565 	struct list_head *last_perm;
566 	int protocol = p->protocol;
567 	int ret;
568 
569 	spin_lock_bh(&inetsw6_lock);
570 
571 	ret = -EINVAL;
572 	if (p->type >= SOCK_MAX)
573 		goto out_illegal;
574 
575 	/* If we are trying to override a permanent protocol, bail. */
576 	answer = NULL;
577 	ret = -EPERM;
578 	last_perm = &inetsw6[p->type];
579 	list_for_each(lh, &inetsw6[p->type]) {
580 		answer = list_entry(lh, struct inet_protosw, list);
581 
582 		/* Check only the non-wild match. */
583 		if (INET_PROTOSW_PERMANENT & answer->flags) {
584 			if (protocol == answer->protocol)
585 				break;
586 			last_perm = lh;
587 		}
588 
589 		answer = NULL;
590 	}
591 	if (answer)
592 		goto out_permanent;
593 
594 	/* Add the new entry after the last permanent entry if any, so that
595 	 * the new entry does not override a permanent entry when matched with
596 	 * a wild-card protocol. But it is allowed to override any existing
597 	 * non-permanent entry.  This means that when we remove this entry, the
598 	 * system automatically returns to the old behavior.
599 	 */
600 	list_add_rcu(&p->list, last_perm);
601 	ret = 0;
602 out:
603 	spin_unlock_bh(&inetsw6_lock);
604 	return ret;
605 
606 out_permanent:
607 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
608 	       protocol);
609 	goto out;
610 
611 out_illegal:
612 	printk(KERN_ERR
613 	       "Ignoring attempt to register invalid socket type %d.\n",
614 	       p->type);
615 	goto out;
616 }
617 
618 EXPORT_SYMBOL(inet6_register_protosw);
619 
620 void
621 inet6_unregister_protosw(struct inet_protosw *p)
622 {
623 	if (INET_PROTOSW_PERMANENT & p->flags) {
624 		printk(KERN_ERR
625 		       "Attempt to unregister permanent protocol %d.\n",
626 		       p->protocol);
627 	} else {
628 		spin_lock_bh(&inetsw6_lock);
629 		list_del_rcu(&p->list);
630 		spin_unlock_bh(&inetsw6_lock);
631 
632 		synchronize_net();
633 	}
634 }
635 
636 EXPORT_SYMBOL(inet6_unregister_protosw);
637 
638 int inet6_sk_rebuild_header(struct sock *sk)
639 {
640 	int err;
641 	struct dst_entry *dst;
642 	struct ipv6_pinfo *np = inet6_sk(sk);
643 
644 	dst = __sk_dst_check(sk, np->dst_cookie);
645 
646 	if (dst == NULL) {
647 		struct inet_sock *inet = inet_sk(sk);
648 		struct in6_addr *final_p = NULL, final;
649 		struct flowi fl;
650 
651 		memset(&fl, 0, sizeof(fl));
652 		fl.proto = sk->sk_protocol;
653 		ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
654 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
655 		fl.fl6_flowlabel = np->flow_label;
656 		fl.oif = sk->sk_bound_dev_if;
657 		fl.fl_ip_dport = inet->dport;
658 		fl.fl_ip_sport = inet->sport;
659 		security_sk_classify_flow(sk, &fl);
660 
661 		if (np->opt && np->opt->srcrt) {
662 			struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
663 			ipv6_addr_copy(&final, &fl.fl6_dst);
664 			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
665 			final_p = &final;
666 		}
667 
668 		err = ip6_dst_lookup(sk, &dst, &fl);
669 		if (err) {
670 			sk->sk_route_caps = 0;
671 			return err;
672 		}
673 		if (final_p)
674 			ipv6_addr_copy(&fl.fl6_dst, final_p);
675 
676 		if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
677 			sk->sk_err_soft = -err;
678 			return err;
679 		}
680 
681 		__ip6_dst_store(sk, dst, NULL, NULL);
682 	}
683 
684 	return 0;
685 }
686 
687 EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);
688 
689 int ipv6_opt_accepted(struct sock *sk, struct sk_buff *skb)
690 {
691 	struct ipv6_pinfo *np = inet6_sk(sk);
692 	struct inet6_skb_parm *opt = IP6CB(skb);
693 
694 	if (np->rxopt.all) {
695 		if ((opt->hop && (np->rxopt.bits.hopopts ||
696 				  np->rxopt.bits.ohopopts)) ||
697 		    ((IPV6_FLOWINFO_MASK &
698 		      *(__be32 *)skb_network_header(skb)) &&
699 		     np->rxopt.bits.rxflow) ||
700 		    (opt->srcrt && (np->rxopt.bits.srcrt ||
701 		     np->rxopt.bits.osrcrt)) ||
702 		    ((opt->dst1 || opt->dst0) &&
703 		     (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
704 			return 1;
705 	}
706 	return 0;
707 }
708 
709 EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
710 
711 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
712 {
713 	const struct inet6_protocol *ops = NULL;
714 
715 	for (;;) {
716 		struct ipv6_opt_hdr *opth;
717 		int len;
718 
719 		if (proto != NEXTHDR_HOP) {
720 			ops = rcu_dereference(inet6_protos[proto]);
721 
722 			if (unlikely(!ops))
723 				break;
724 
725 			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
726 				break;
727 		}
728 
729 		if (unlikely(!pskb_may_pull(skb, 8)))
730 			break;
731 
732 		opth = (void *)skb->data;
733 		len = ipv6_optlen(opth);
734 
735 		if (unlikely(!pskb_may_pull(skb, len)))
736 			break;
737 
738 		proto = opth->nexthdr;
739 		__skb_pull(skb, len);
740 	}
741 
742 	return proto;
743 }
744 
745 static int ipv6_gso_send_check(struct sk_buff *skb)
746 {
747 	struct ipv6hdr *ipv6h;
748 	const struct inet6_protocol *ops;
749 	int err = -EINVAL;
750 
751 	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
752 		goto out;
753 
754 	ipv6h = ipv6_hdr(skb);
755 	__skb_pull(skb, sizeof(*ipv6h));
756 	err = -EPROTONOSUPPORT;
757 
758 	rcu_read_lock();
759 	ops = rcu_dereference(inet6_protos[
760 		ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
761 
762 	if (likely(ops && ops->gso_send_check)) {
763 		skb_reset_transport_header(skb);
764 		err = ops->gso_send_check(skb);
765 	}
766 	rcu_read_unlock();
767 
768 out:
769 	return err;
770 }
771 
772 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, int features)
773 {
774 	struct sk_buff *segs = ERR_PTR(-EINVAL);
775 	struct ipv6hdr *ipv6h;
776 	const struct inet6_protocol *ops;
777 	int proto;
778 	struct frag_hdr *fptr;
779 	unsigned int unfrag_ip6hlen;
780 	u8 *prevhdr;
781 	int offset = 0;
782 
783 	if (!(features & NETIF_F_V6_CSUM))
784 		features &= ~NETIF_F_SG;
785 
786 	if (unlikely(skb_shinfo(skb)->gso_type &
787 		     ~(SKB_GSO_UDP |
788 		       SKB_GSO_DODGY |
789 		       SKB_GSO_TCP_ECN |
790 		       SKB_GSO_TCPV6 |
791 		       0)))
792 		goto out;
793 
794 	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
795 		goto out;
796 
797 	ipv6h = ipv6_hdr(skb);
798 	__skb_pull(skb, sizeof(*ipv6h));
799 	segs = ERR_PTR(-EPROTONOSUPPORT);
800 
801 	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
802 	rcu_read_lock();
803 	ops = rcu_dereference(inet6_protos[proto]);
804 	if (likely(ops && ops->gso_segment)) {
805 		skb_reset_transport_header(skb);
806 		segs = ops->gso_segment(skb, features);
807 	}
808 	rcu_read_unlock();
809 
810 	if (unlikely(IS_ERR(segs)))
811 		goto out;
812 
813 	for (skb = segs; skb; skb = skb->next) {
814 		ipv6h = ipv6_hdr(skb);
815 		ipv6h->payload_len = htons(skb->len - skb->mac_len -
816 					   sizeof(*ipv6h));
817 		if (proto == IPPROTO_UDP) {
818 			unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
819 			fptr = (struct frag_hdr *)(skb_network_header(skb) +
820 				unfrag_ip6hlen);
821 			fptr->frag_off = htons(offset);
822 			if (skb->next != NULL)
823 				fptr->frag_off |= htons(IP6_MF);
824 			offset += (ntohs(ipv6h->payload_len) -
825 				   sizeof(struct frag_hdr));
826 		}
827 	}
828 
829 out:
830 	return segs;
831 }
832 
833 struct ipv6_gro_cb {
834 	struct napi_gro_cb napi;
835 	int proto;
836 };
837 
838 #define IPV6_GRO_CB(skb) ((struct ipv6_gro_cb *)(skb)->cb)
839 
840 static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
841 					 struct sk_buff *skb)
842 {
843 	const struct inet6_protocol *ops;
844 	struct sk_buff **pp = NULL;
845 	struct sk_buff *p;
846 	struct ipv6hdr *iph;
847 	unsigned int nlen;
848 	unsigned int hlen;
849 	unsigned int off;
850 	int flush = 1;
851 	int proto;
852 	__wsum csum;
853 
854 	off = skb_gro_offset(skb);
855 	hlen = off + sizeof(*iph);
856 	iph = skb_gro_header_fast(skb, off);
857 	if (skb_gro_header_hard(skb, hlen)) {
858 		iph = skb_gro_header_slow(skb, hlen, off);
859 		if (unlikely(!iph))
860 			goto out;
861 	}
862 
863 	skb_gro_pull(skb, sizeof(*iph));
864 	skb_set_transport_header(skb, skb_gro_offset(skb));
865 
866 	flush += ntohs(iph->payload_len) != skb_gro_len(skb);
867 
868 	rcu_read_lock();
869 	proto = iph->nexthdr;
870 	ops = rcu_dereference(inet6_protos[proto]);
871 	if (!ops || !ops->gro_receive) {
872 		__pskb_pull(skb, skb_gro_offset(skb));
873 		proto = ipv6_gso_pull_exthdrs(skb, proto);
874 		skb_gro_pull(skb, -skb_transport_offset(skb));
875 		skb_reset_transport_header(skb);
876 		__skb_push(skb, skb_gro_offset(skb));
877 
878 		if (!ops || !ops->gro_receive)
879 			goto out_unlock;
880 
881 		iph = ipv6_hdr(skb);
882 	}
883 
884 	IPV6_GRO_CB(skb)->proto = proto;
885 
886 	flush--;
887 	nlen = skb_network_header_len(skb);
888 
889 	for (p = *head; p; p = p->next) {
890 		struct ipv6hdr *iph2;
891 
892 		if (!NAPI_GRO_CB(p)->same_flow)
893 			continue;
894 
895 		iph2 = ipv6_hdr(p);
896 
897 		/* All fields must match except length. */
898 		if (nlen != skb_network_header_len(p) ||
899 		    memcmp(iph, iph2, offsetof(struct ipv6hdr, payload_len)) ||
900 		    memcmp(&iph->nexthdr, &iph2->nexthdr,
901 			   nlen - offsetof(struct ipv6hdr, nexthdr))) {
902 			NAPI_GRO_CB(p)->same_flow = 0;
903 			continue;
904 		}
905 
906 		NAPI_GRO_CB(p)->flush |= flush;
907 	}
908 
909 	NAPI_GRO_CB(skb)->flush |= flush;
910 
911 	csum = skb->csum;
912 	skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
913 
914 	pp = ops->gro_receive(head, skb);
915 
916 	skb->csum = csum;
917 
918 out_unlock:
919 	rcu_read_unlock();
920 
921 out:
922 	NAPI_GRO_CB(skb)->flush |= flush;
923 
924 	return pp;
925 }
926 
927 static int ipv6_gro_complete(struct sk_buff *skb)
928 {
929 	const struct inet6_protocol *ops;
930 	struct ipv6hdr *iph = ipv6_hdr(skb);
931 	int err = -ENOSYS;
932 
933 	iph->payload_len = htons(skb->len - skb_network_offset(skb) -
934 				 sizeof(*iph));
935 
936 	rcu_read_lock();
937 	ops = rcu_dereference(inet6_protos[IPV6_GRO_CB(skb)->proto]);
938 	if (WARN_ON(!ops || !ops->gro_complete))
939 		goto out_unlock;
940 
941 	err = ops->gro_complete(skb);
942 
943 out_unlock:
944 	rcu_read_unlock();
945 
946 	return err;
947 }
948 
949 static struct packet_type ipv6_packet_type __read_mostly = {
950 	.type = cpu_to_be16(ETH_P_IPV6),
951 	.func = ipv6_rcv,
952 	.gso_send_check = ipv6_gso_send_check,
953 	.gso_segment = ipv6_gso_segment,
954 	.gro_receive = ipv6_gro_receive,
955 	.gro_complete = ipv6_gro_complete,
956 };
957 
958 static int __init ipv6_packet_init(void)
959 {
960 	dev_add_pack(&ipv6_packet_type);
961 	return 0;
962 }
963 
964 static void ipv6_packet_cleanup(void)
965 {
966 	dev_remove_pack(&ipv6_packet_type);
967 }
968 
969 static int __net_init ipv6_init_mibs(struct net *net)
970 {
971 	if (snmp_mib_init((void **)net->mib.udp_stats_in6,
972 			  sizeof (struct udp_mib)) < 0)
973 		return -ENOMEM;
974 	if (snmp_mib_init((void **)net->mib.udplite_stats_in6,
975 			  sizeof (struct udp_mib)) < 0)
976 		goto err_udplite_mib;
977 	if (snmp_mib_init((void **)net->mib.ipv6_statistics,
978 			  sizeof(struct ipstats_mib)) < 0)
979 		goto err_ip_mib;
980 	if (snmp_mib_init((void **)net->mib.icmpv6_statistics,
981 			  sizeof(struct icmpv6_mib)) < 0)
982 		goto err_icmp_mib;
983 	if (snmp_mib_init((void **)net->mib.icmpv6msg_statistics,
984 			  sizeof(struct icmpv6msg_mib)) < 0)
985 		goto err_icmpmsg_mib;
986 	return 0;
987 
988 err_icmpmsg_mib:
989 	snmp_mib_free((void **)net->mib.icmpv6_statistics);
990 err_icmp_mib:
991 	snmp_mib_free((void **)net->mib.ipv6_statistics);
992 err_ip_mib:
993 	snmp_mib_free((void **)net->mib.udplite_stats_in6);
994 err_udplite_mib:
995 	snmp_mib_free((void **)net->mib.udp_stats_in6);
996 	return -ENOMEM;
997 }
998 
999 static void __net_exit ipv6_cleanup_mibs(struct net *net)
1000 {
1001 	snmp_mib_free((void **)net->mib.udp_stats_in6);
1002 	snmp_mib_free((void **)net->mib.udplite_stats_in6);
1003 	snmp_mib_free((void **)net->mib.ipv6_statistics);
1004 	snmp_mib_free((void **)net->mib.icmpv6_statistics);
1005 	snmp_mib_free((void **)net->mib.icmpv6msg_statistics);
1006 }
1007 
1008 static int __net_init inet6_net_init(struct net *net)
1009 {
1010 	int err = 0;
1011 
1012 	net->ipv6.sysctl.bindv6only = 0;
1013 	net->ipv6.sysctl.icmpv6_time = 1*HZ;
1014 
1015 	err = ipv6_init_mibs(net);
1016 	if (err)
1017 		return err;
1018 #ifdef CONFIG_PROC_FS
1019 	err = udp6_proc_init(net);
1020 	if (err)
1021 		goto out;
1022 	err = tcp6_proc_init(net);
1023 	if (err)
1024 		goto proc_tcp6_fail;
1025 	err = ac6_proc_init(net);
1026 	if (err)
1027 		goto proc_ac6_fail;
1028 #endif
1029 	return err;
1030 
1031 #ifdef CONFIG_PROC_FS
1032 proc_ac6_fail:
1033 	tcp6_proc_exit(net);
1034 proc_tcp6_fail:
1035 	udp6_proc_exit(net);
1036 out:
1037 	ipv6_cleanup_mibs(net);
1038 	return err;
1039 #endif
1040 }
1041 
1042 static void inet6_net_exit(struct net *net)
1043 {
1044 #ifdef CONFIG_PROC_FS
1045 	udp6_proc_exit(net);
1046 	tcp6_proc_exit(net);
1047 	ac6_proc_exit(net);
1048 #endif
1049 	ipv6_cleanup_mibs(net);
1050 }
1051 
1052 static struct pernet_operations inet6_net_ops = {
1053 	.init = inet6_net_init,
1054 	.exit = inet6_net_exit,
1055 };
1056 
1057 static int __init inet6_init(void)
1058 {
1059 	struct sk_buff *dummy_skb;
1060 	struct list_head *r;
1061 	int err = 0;
1062 
1063 	BUILD_BUG_ON(sizeof(struct inet6_skb_parm) > sizeof(dummy_skb->cb));
1064 
1065 	/* Register the socket-side information for inet6_create.  */
1066 	for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
1067 		INIT_LIST_HEAD(r);
1068 
1069 	if (disable_ipv6_mod) {
1070 		printk(KERN_INFO
1071 		       "IPv6: Loaded, but administratively disabled, "
1072 		       "reboot required to enable\n");
1073 		goto out;
1074 	}
1075 
1076 	err = proto_register(&tcpv6_prot, 1);
1077 	if (err)
1078 		goto out;
1079 
1080 	err = proto_register(&udpv6_prot, 1);
1081 	if (err)
1082 		goto out_unregister_tcp_proto;
1083 
1084 	err = proto_register(&udplitev6_prot, 1);
1085 	if (err)
1086 		goto out_unregister_udp_proto;
1087 
1088 	err = proto_register(&rawv6_prot, 1);
1089 	if (err)
1090 		goto out_unregister_udplite_proto;
1091 
1092 
1093 	/* We MUST register RAW sockets before we create the ICMP6,
1094 	 * IGMP6, or NDISC control sockets.
1095 	 */
1096 	err = rawv6_init();
1097 	if (err)
1098 		goto out_unregister_raw_proto;
1099 
1100 	/* Register the family here so that the init calls below will
1101 	 * be able to create sockets. (?? is this dangerous ??)
1102 	 */
1103 	err = sock_register(&inet6_family_ops);
1104 	if (err)
1105 		goto out_sock_register_fail;
1106 
1107 #ifdef CONFIG_SYSCTL
1108 	err = ipv6_static_sysctl_register();
1109 	if (err)
1110 		goto static_sysctl_fail;
1111 #endif
1112 	/*
1113 	 *	ipngwg API draft makes clear that the correct semantics
1114 	 *	for TCP and UDP is to consider one TCP and UDP instance
1115 	 *	in a host availiable by both INET and INET6 APIs and
1116 	 *	able to communicate via both network protocols.
1117 	 */
1118 
1119 	err = register_pernet_subsys(&inet6_net_ops);
1120 	if (err)
1121 		goto register_pernet_fail;
1122 	err = icmpv6_init();
1123 	if (err)
1124 		goto icmp_fail;
1125 	err = ip6_mr_init();
1126 	if (err)
1127 		goto ipmr_fail;
1128 	err = ndisc_init();
1129 	if (err)
1130 		goto ndisc_fail;
1131 	err = igmp6_init();
1132 	if (err)
1133 		goto igmp_fail;
1134 	err = ipv6_netfilter_init();
1135 	if (err)
1136 		goto netfilter_fail;
1137 	/* Create /proc/foo6 entries. */
1138 #ifdef CONFIG_PROC_FS
1139 	err = -ENOMEM;
1140 	if (raw6_proc_init())
1141 		goto proc_raw6_fail;
1142 	if (udplite6_proc_init())
1143 		goto proc_udplite6_fail;
1144 	if (ipv6_misc_proc_init())
1145 		goto proc_misc6_fail;
1146 	if (if6_proc_init())
1147 		goto proc_if6_fail;
1148 #endif
1149 	err = ip6_route_init();
1150 	if (err)
1151 		goto ip6_route_fail;
1152 	err = ip6_flowlabel_init();
1153 	if (err)
1154 		goto ip6_flowlabel_fail;
1155 	err = addrconf_init();
1156 	if (err)
1157 		goto addrconf_fail;
1158 
1159 	/* Init v6 extension headers. */
1160 	err = ipv6_exthdrs_init();
1161 	if (err)
1162 		goto ipv6_exthdrs_fail;
1163 
1164 	err = ipv6_frag_init();
1165 	if (err)
1166 		goto ipv6_frag_fail;
1167 
1168 	/* Init v6 transport protocols. */
1169 	err = udpv6_init();
1170 	if (err)
1171 		goto udpv6_fail;
1172 
1173 	err = udplitev6_init();
1174 	if (err)
1175 		goto udplitev6_fail;
1176 
1177 	err = tcpv6_init();
1178 	if (err)
1179 		goto tcpv6_fail;
1180 
1181 	err = ipv6_packet_init();
1182 	if (err)
1183 		goto ipv6_packet_fail;
1184 
1185 #ifdef CONFIG_SYSCTL
1186 	err = ipv6_sysctl_register();
1187 	if (err)
1188 		goto sysctl_fail;
1189 #endif
1190 out:
1191 	return err;
1192 
1193 #ifdef CONFIG_SYSCTL
1194 sysctl_fail:
1195 	ipv6_packet_cleanup();
1196 #endif
1197 ipv6_packet_fail:
1198 	tcpv6_exit();
1199 tcpv6_fail:
1200 	udplitev6_exit();
1201 udplitev6_fail:
1202 	udpv6_exit();
1203 udpv6_fail:
1204 	ipv6_frag_exit();
1205 ipv6_frag_fail:
1206 	ipv6_exthdrs_exit();
1207 ipv6_exthdrs_fail:
1208 	addrconf_cleanup();
1209 addrconf_fail:
1210 	ip6_flowlabel_cleanup();
1211 ip6_flowlabel_fail:
1212 	ip6_route_cleanup();
1213 ip6_route_fail:
1214 #ifdef CONFIG_PROC_FS
1215 	if6_proc_exit();
1216 proc_if6_fail:
1217 	ipv6_misc_proc_exit();
1218 proc_misc6_fail:
1219 	udplite6_proc_exit();
1220 proc_udplite6_fail:
1221 	raw6_proc_exit();
1222 proc_raw6_fail:
1223 #endif
1224 	ipv6_netfilter_fini();
1225 netfilter_fail:
1226 	igmp6_cleanup();
1227 igmp_fail:
1228 	ndisc_cleanup();
1229 ndisc_fail:
1230 	ip6_mr_cleanup();
1231 ipmr_fail:
1232 	icmpv6_cleanup();
1233 icmp_fail:
1234 	unregister_pernet_subsys(&inet6_net_ops);
1235 register_pernet_fail:
1236 #ifdef CONFIG_SYSCTL
1237 	ipv6_static_sysctl_unregister();
1238 static_sysctl_fail:
1239 #endif
1240 	sock_unregister(PF_INET6);
1241 	rtnl_unregister_all(PF_INET6);
1242 out_sock_register_fail:
1243 	rawv6_exit();
1244 out_unregister_raw_proto:
1245 	proto_unregister(&rawv6_prot);
1246 out_unregister_udplite_proto:
1247 	proto_unregister(&udplitev6_prot);
1248 out_unregister_udp_proto:
1249 	proto_unregister(&udpv6_prot);
1250 out_unregister_tcp_proto:
1251 	proto_unregister(&tcpv6_prot);
1252 	goto out;
1253 }
1254 module_init(inet6_init);
1255 
1256 static void __exit inet6_exit(void)
1257 {
1258 	if (disable_ipv6_mod)
1259 		return;
1260 
1261 	/* First of all disallow new sockets creation. */
1262 	sock_unregister(PF_INET6);
1263 	/* Disallow any further netlink messages */
1264 	rtnl_unregister_all(PF_INET6);
1265 
1266 #ifdef CONFIG_SYSCTL
1267 	ipv6_sysctl_unregister();
1268 #endif
1269 	udpv6_exit();
1270 	udplitev6_exit();
1271 	tcpv6_exit();
1272 
1273 	/* Cleanup code parts. */
1274 	ipv6_packet_cleanup();
1275 	ipv6_frag_exit();
1276 	ipv6_exthdrs_exit();
1277 	addrconf_cleanup();
1278 	ip6_flowlabel_cleanup();
1279 	ip6_route_cleanup();
1280 #ifdef CONFIG_PROC_FS
1281 
1282 	/* Cleanup code parts. */
1283 	if6_proc_exit();
1284 	ipv6_misc_proc_exit();
1285 	udplite6_proc_exit();
1286 	raw6_proc_exit();
1287 #endif
1288 	ipv6_netfilter_fini();
1289 	igmp6_cleanup();
1290 	ndisc_cleanup();
1291 	ip6_mr_cleanup();
1292 	icmpv6_cleanup();
1293 	rawv6_exit();
1294 
1295 	unregister_pernet_subsys(&inet6_net_ops);
1296 #ifdef CONFIG_SYSCTL
1297 	ipv6_static_sysctl_unregister();
1298 #endif
1299 	proto_unregister(&rawv6_prot);
1300 	proto_unregister(&udplitev6_prot);
1301 	proto_unregister(&udpv6_prot);
1302 	proto_unregister(&tcpv6_prot);
1303 
1304 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
1305 }
1306 module_exit(inet6_exit);
1307 
1308 MODULE_ALIAS_NETPROTO(PF_INET6);
1309