xref: /linux/net/ipv6/af_inet6.c (revision 9406b485dea5e25bed7c81cd822747d494cc8bde)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	PF_INET6 socket protocol family
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Pedro Roque		<roque@di.fc.ul.pt>
8  *
9  *	Adapted from linux/net/ipv4/af_inet.c
10  *
11  *	Fixes:
12  *	piggy, Karl Knutson	:	Socket protocol table
13  *	Hideaki YOSHIFUJI	:	sin6_scope_id support
14  *	Arnaldo Melo		:	check proc_net_create return, cleanups
15  */
16 
17 #define pr_fmt(fmt) "IPv6: " fmt
18 
19 #include <linux/module.h>
20 #include <linux/capability.h>
21 #include <linux/errno.h>
22 #include <linux/types.h>
23 #include <linux/socket.h>
24 #include <linux/in.h>
25 #include <linux/kernel.h>
26 #include <linux/timer.h>
27 #include <linux/string.h>
28 #include <linux/sockios.h>
29 #include <linux/net.h>
30 #include <linux/fcntl.h>
31 #include <linux/mm.h>
32 #include <linux/interrupt.h>
33 #include <linux/proc_fs.h>
34 #include <linux/stat.h>
35 #include <linux/init.h>
36 #include <linux/slab.h>
37 
38 #include <linux/inet.h>
39 #include <linux/netdevice.h>
40 #include <linux/icmpv6.h>
41 #include <linux/netfilter_ipv6.h>
42 
43 #include <net/ip.h>
44 #include <net/ipv6.h>
45 #include <net/udp.h>
46 #include <net/udplite.h>
47 #include <net/tcp.h>
48 #include <net/ping.h>
49 #include <net/protocol.h>
50 #include <net/inet_common.h>
51 #include <net/route.h>
52 #include <net/transp_v6.h>
53 #include <net/ip6_route.h>
54 #include <net/addrconf.h>
55 #include <net/ipv6_stubs.h>
56 #include <net/ndisc.h>
57 #ifdef CONFIG_IPV6_TUNNEL
58 #include <net/ip6_tunnel.h>
59 #endif
60 #include <net/calipso.h>
61 #include <net/seg6.h>
62 #include <net/rpl.h>
63 
64 #include <linux/uaccess.h>
65 #include <linux/mroute6.h>
66 
67 #include "ip6_offload.h"
68 
69 MODULE_AUTHOR("Cast of dozens");
70 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
71 MODULE_LICENSE("GPL");
72 
73 /* The inetsw6 table contains everything that inet6_create needs to
74  * build a new socket.
75  */
76 static struct list_head inetsw6[SOCK_MAX];
77 static DEFINE_SPINLOCK(inetsw6_lock);
78 
79 struct ipv6_params ipv6_defaults = {
80 	.disable_ipv6 = 0,
81 	.autoconf = 1,
82 };
83 
84 static int disable_ipv6_mod;
85 
86 module_param_named(disable, disable_ipv6_mod, int, 0444);
87 MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
88 
89 module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
90 MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
91 
92 module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
93 MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");
94 
95 bool ipv6_mod_enabled(void)
96 {
97 	return disable_ipv6_mod == 0;
98 }
99 EXPORT_SYMBOL_GPL(ipv6_mod_enabled);
100 
101 static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
102 {
103 	const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
104 
105 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
106 }
107 
108 static int inet6_create(struct net *net, struct socket *sock, int protocol,
109 			int kern)
110 {
111 	struct inet_sock *inet;
112 	struct ipv6_pinfo *np;
113 	struct sock *sk;
114 	struct inet_protosw *answer;
115 	struct proto *answer_prot;
116 	unsigned char answer_flags;
117 	int try_loading_module = 0;
118 	int err;
119 
120 	if (protocol < 0 || protocol >= IPPROTO_MAX)
121 		return -EINVAL;
122 
123 	/* Look for the requested type/protocol pair. */
124 lookup_protocol:
125 	err = -ESOCKTNOSUPPORT;
126 	rcu_read_lock();
127 	list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
128 
129 		err = 0;
130 		/* Check the non-wild match. */
131 		if (protocol == answer->protocol) {
132 			if (protocol != IPPROTO_IP)
133 				break;
134 		} else {
135 			/* Check for the two wild cases. */
136 			if (IPPROTO_IP == protocol) {
137 				protocol = answer->protocol;
138 				break;
139 			}
140 			if (IPPROTO_IP == answer->protocol)
141 				break;
142 		}
143 		err = -EPROTONOSUPPORT;
144 	}
145 
146 	if (err) {
147 		if (try_loading_module < 2) {
148 			rcu_read_unlock();
149 			/*
150 			 * Be more specific, e.g. net-pf-10-proto-132-type-1
151 			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
152 			 */
153 			if (++try_loading_module == 1)
154 				request_module("net-pf-%d-proto-%d-type-%d",
155 						PF_INET6, protocol, sock->type);
156 			/*
157 			 * Fall back to generic, e.g. net-pf-10-proto-132
158 			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
159 			 */
160 			else
161 				request_module("net-pf-%d-proto-%d",
162 						PF_INET6, protocol);
163 			goto lookup_protocol;
164 		} else
165 			goto out_rcu_unlock;
166 	}
167 
168 	err = -EPERM;
169 	if (sock->type == SOCK_RAW && !kern &&
170 	    !ns_capable(net->user_ns, CAP_NET_RAW))
171 		goto out_rcu_unlock;
172 
173 	sock->ops = answer->ops;
174 	answer_prot = answer->prot;
175 	answer_flags = answer->flags;
176 	rcu_read_unlock();
177 
178 	WARN_ON(!answer_prot->slab);
179 
180 	err = -ENOBUFS;
181 	sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot, kern);
182 	if (!sk)
183 		goto out;
184 
185 	sock_init_data(sock, sk);
186 
187 	err = 0;
188 	if (INET_PROTOSW_REUSE & answer_flags)
189 		sk->sk_reuse = SK_CAN_REUSE;
190 
191 	inet = inet_sk(sk);
192 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
193 
194 	if (SOCK_RAW == sock->type) {
195 		inet->inet_num = protocol;
196 		if (IPPROTO_RAW == protocol)
197 			inet->hdrincl = 1;
198 	}
199 
200 	sk->sk_destruct		= inet_sock_destruct;
201 	sk->sk_family		= PF_INET6;
202 	sk->sk_protocol		= protocol;
203 
204 	sk->sk_backlog_rcv	= answer->prot->backlog_rcv;
205 
206 	inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
207 	np->hop_limit	= -1;
208 	np->mcast_hops	= IPV6_DEFAULT_MCASTHOPS;
209 	np->mc_loop	= 1;
210 	np->mc_all	= 1;
211 	np->pmtudisc	= IPV6_PMTUDISC_WANT;
212 	np->repflow	= net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ESTABLISHED;
213 	sk->sk_ipv6only	= net->ipv6.sysctl.bindv6only;
214 
215 	/* Init the ipv4 part of the socket since we can have sockets
216 	 * using v6 API for ipv4.
217 	 */
218 	inet->uc_ttl	= -1;
219 
220 	inet->mc_loop	= 1;
221 	inet->mc_ttl	= 1;
222 	inet->mc_index	= 0;
223 	inet->mc_list	= NULL;
224 	inet->rcv_tos	= 0;
225 
226 	if (net->ipv4.sysctl_ip_no_pmtu_disc)
227 		inet->pmtudisc = IP_PMTUDISC_DONT;
228 	else
229 		inet->pmtudisc = IP_PMTUDISC_WANT;
230 	/*
231 	 * Increment only the relevant sk_prot->socks debug field, this changes
232 	 * the previous behaviour of incrementing both the equivalent to
233 	 * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
234 	 *
235 	 * This allows better debug granularity as we'll know exactly how many
236 	 * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
237 	 * transport protocol socks. -acme
238 	 */
239 	sk_refcnt_debug_inc(sk);
240 
241 	if (inet->inet_num) {
242 		/* It assumes that any protocol which allows
243 		 * the user to assign a number at socket
244 		 * creation time automatically shares.
245 		 */
246 		inet->inet_sport = htons(inet->inet_num);
247 		err = sk->sk_prot->hash(sk);
248 		if (err) {
249 			sk_common_release(sk);
250 			goto out;
251 		}
252 	}
253 	if (sk->sk_prot->init) {
254 		err = sk->sk_prot->init(sk);
255 		if (err) {
256 			sk_common_release(sk);
257 			goto out;
258 		}
259 	}
260 
261 	if (!kern) {
262 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
263 		if (err) {
264 			sk_common_release(sk);
265 			goto out;
266 		}
267 	}
268 out:
269 	return err;
270 out_rcu_unlock:
271 	rcu_read_unlock();
272 	goto out;
273 }
274 
275 static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
276 			u32 flags)
277 {
278 	struct sockaddr_in6 *addr = (struct sockaddr_in6 *)uaddr;
279 	struct inet_sock *inet = inet_sk(sk);
280 	struct ipv6_pinfo *np = inet6_sk(sk);
281 	struct net *net = sock_net(sk);
282 	__be32 v4addr = 0;
283 	unsigned short snum;
284 	bool saved_ipv6only;
285 	int addr_type = 0;
286 	int err = 0;
287 
288 	if (addr->sin6_family != AF_INET6)
289 		return -EAFNOSUPPORT;
290 
291 	addr_type = ipv6_addr_type(&addr->sin6_addr);
292 	if ((addr_type & IPV6_ADDR_MULTICAST) && sk->sk_type == SOCK_STREAM)
293 		return -EINVAL;
294 
295 	snum = ntohs(addr->sin6_port);
296 	if (snum && inet_port_requires_bind_service(net, snum) &&
297 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
298 		return -EACCES;
299 
300 	if (flags & BIND_WITH_LOCK)
301 		lock_sock(sk);
302 
303 	/* Check these errors (active socket, double bind). */
304 	if (sk->sk_state != TCP_CLOSE || inet->inet_num) {
305 		err = -EINVAL;
306 		goto out;
307 	}
308 
309 	/* Check if the address belongs to the host. */
310 	if (addr_type == IPV6_ADDR_MAPPED) {
311 		struct net_device *dev = NULL;
312 		int chk_addr_ret;
313 
314 		/* Binding to v4-mapped address on a v6-only socket
315 		 * makes no sense
316 		 */
317 		if (sk->sk_ipv6only) {
318 			err = -EINVAL;
319 			goto out;
320 		}
321 
322 		rcu_read_lock();
323 		if (sk->sk_bound_dev_if) {
324 			dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
325 			if (!dev) {
326 				err = -ENODEV;
327 				goto out_unlock;
328 			}
329 		}
330 
331 		/* Reproduce AF_INET checks to make the bindings consistent */
332 		v4addr = addr->sin6_addr.s6_addr32[3];
333 		chk_addr_ret = inet_addr_type_dev_table(net, dev, v4addr);
334 		rcu_read_unlock();
335 
336 		if (!inet_can_nonlocal_bind(net, inet) &&
337 		    v4addr != htonl(INADDR_ANY) &&
338 		    chk_addr_ret != RTN_LOCAL &&
339 		    chk_addr_ret != RTN_MULTICAST &&
340 		    chk_addr_ret != RTN_BROADCAST) {
341 			err = -EADDRNOTAVAIL;
342 			goto out;
343 		}
344 	} else {
345 		if (addr_type != IPV6_ADDR_ANY) {
346 			struct net_device *dev = NULL;
347 
348 			rcu_read_lock();
349 			if (__ipv6_addr_needs_scope_id(addr_type)) {
350 				if (addr_len >= sizeof(struct sockaddr_in6) &&
351 				    addr->sin6_scope_id) {
352 					/* Override any existing binding, if another one
353 					 * is supplied by user.
354 					 */
355 					sk->sk_bound_dev_if = addr->sin6_scope_id;
356 				}
357 
358 				/* Binding to link-local address requires an interface */
359 				if (!sk->sk_bound_dev_if) {
360 					err = -EINVAL;
361 					goto out_unlock;
362 				}
363 			}
364 
365 			if (sk->sk_bound_dev_if) {
366 				dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
367 				if (!dev) {
368 					err = -ENODEV;
369 					goto out_unlock;
370 				}
371 			}
372 
373 			/* ipv4 addr of the socket is invalid.  Only the
374 			 * unspecified and mapped address have a v4 equivalent.
375 			 */
376 			v4addr = LOOPBACK4_IPV6;
377 			if (!(addr_type & IPV6_ADDR_MULTICAST))	{
378 				if (!ipv6_can_nonlocal_bind(net, inet) &&
379 				    !ipv6_chk_addr(net, &addr->sin6_addr,
380 						   dev, 0)) {
381 					err = -EADDRNOTAVAIL;
382 					goto out_unlock;
383 				}
384 			}
385 			rcu_read_unlock();
386 		}
387 	}
388 
389 	inet->inet_rcv_saddr = v4addr;
390 	inet->inet_saddr = v4addr;
391 
392 	sk->sk_v6_rcv_saddr = addr->sin6_addr;
393 
394 	if (!(addr_type & IPV6_ADDR_MULTICAST))
395 		np->saddr = addr->sin6_addr;
396 
397 	saved_ipv6only = sk->sk_ipv6only;
398 	if (addr_type != IPV6_ADDR_ANY && addr_type != IPV6_ADDR_MAPPED)
399 		sk->sk_ipv6only = 1;
400 
401 	/* Make sure we are allowed to bind here. */
402 	if (snum || !(inet->bind_address_no_port ||
403 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
404 		if (sk->sk_prot->get_port(sk, snum)) {
405 			sk->sk_ipv6only = saved_ipv6only;
406 			inet_reset_saddr(sk);
407 			err = -EADDRINUSE;
408 			goto out;
409 		}
410 		if (!(flags & BIND_FROM_BPF)) {
411 			err = BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk);
412 			if (err) {
413 				sk->sk_ipv6only = saved_ipv6only;
414 				inet_reset_saddr(sk);
415 				goto out;
416 			}
417 		}
418 	}
419 
420 	if (addr_type != IPV6_ADDR_ANY)
421 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
422 	if (snum)
423 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
424 	inet->inet_sport = htons(inet->inet_num);
425 	inet->inet_dport = 0;
426 	inet->inet_daddr = 0;
427 out:
428 	if (flags & BIND_WITH_LOCK)
429 		release_sock(sk);
430 	return err;
431 out_unlock:
432 	rcu_read_unlock();
433 	goto out;
434 }
435 
436 /* bind for INET6 API */
437 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
438 {
439 	struct sock *sk = sock->sk;
440 	int err = 0;
441 
442 	/* If the socket has its own bind function then use it. */
443 	if (sk->sk_prot->bind)
444 		return sk->sk_prot->bind(sk, uaddr, addr_len);
445 
446 	if (addr_len < SIN6_LEN_RFC2133)
447 		return -EINVAL;
448 
449 	/* BPF prog is run before any checks are done so that if the prog
450 	 * changes context in a wrong way it will be caught.
451 	 */
452 	err = BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr);
453 	if (err)
454 		return err;
455 
456 	return __inet6_bind(sk, uaddr, addr_len, BIND_WITH_LOCK);
457 }
458 EXPORT_SYMBOL(inet6_bind);
459 
460 int inet6_release(struct socket *sock)
461 {
462 	struct sock *sk = sock->sk;
463 
464 	if (!sk)
465 		return -EINVAL;
466 
467 	/* Free mc lists */
468 	ipv6_sock_mc_close(sk);
469 
470 	/* Free ac lists */
471 	ipv6_sock_ac_close(sk);
472 
473 	return inet_release(sock);
474 }
475 EXPORT_SYMBOL(inet6_release);
476 
477 void inet6_destroy_sock(struct sock *sk)
478 {
479 	struct ipv6_pinfo *np = inet6_sk(sk);
480 	struct sk_buff *skb;
481 	struct ipv6_txoptions *opt;
482 
483 	/* Release rx options */
484 
485 	skb = xchg(&np->pktoptions, NULL);
486 	kfree_skb(skb);
487 
488 	skb = xchg(&np->rxpmtu, NULL);
489 	kfree_skb(skb);
490 
491 	/* Free flowlabels */
492 	fl6_free_socklist(sk);
493 
494 	/* Free tx options */
495 
496 	opt = xchg((__force struct ipv6_txoptions **)&np->opt, NULL);
497 	if (opt) {
498 		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
499 		txopt_put(opt);
500 	}
501 }
502 EXPORT_SYMBOL_GPL(inet6_destroy_sock);
503 
504 /*
505  *	This does both peername and sockname.
506  */
507 
508 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
509 		 int peer)
510 {
511 	struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr;
512 	struct sock *sk = sock->sk;
513 	struct inet_sock *inet = inet_sk(sk);
514 	struct ipv6_pinfo *np = inet6_sk(sk);
515 
516 	sin->sin6_family = AF_INET6;
517 	sin->sin6_flowinfo = 0;
518 	sin->sin6_scope_id = 0;
519 	if (peer) {
520 		if (!inet->inet_dport)
521 			return -ENOTCONN;
522 		if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
523 		    peer == 1)
524 			return -ENOTCONN;
525 		sin->sin6_port = inet->inet_dport;
526 		sin->sin6_addr = sk->sk_v6_daddr;
527 		if (np->sndflow)
528 			sin->sin6_flowinfo = np->flow_label;
529 	} else {
530 		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
531 			sin->sin6_addr = np->saddr;
532 		else
533 			sin->sin6_addr = sk->sk_v6_rcv_saddr;
534 
535 		sin->sin6_port = inet->inet_sport;
536 	}
537 	sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr,
538 						 sk->sk_bound_dev_if);
539 	return sizeof(*sin);
540 }
541 EXPORT_SYMBOL(inet6_getname);
542 
543 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
544 {
545 	struct sock *sk = sock->sk;
546 	struct net *net = sock_net(sk);
547 
548 	switch (cmd) {
549 	case SIOCADDRT:
550 	case SIOCDELRT:
551 
552 		return ipv6_route_ioctl(net, cmd, (void __user *)arg);
553 
554 	case SIOCSIFADDR:
555 		return addrconf_add_ifaddr(net, (void __user *) arg);
556 	case SIOCDIFADDR:
557 		return addrconf_del_ifaddr(net, (void __user *) arg);
558 	case SIOCSIFDSTADDR:
559 		return addrconf_set_dstaddr(net, (void __user *) arg);
560 	default:
561 		if (!sk->sk_prot->ioctl)
562 			return -ENOIOCTLCMD;
563 		return sk->sk_prot->ioctl(sk, cmd, arg);
564 	}
565 	/*NOTREACHED*/
566 	return 0;
567 }
568 EXPORT_SYMBOL(inet6_ioctl);
569 
570 INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
571 					    size_t));
572 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
573 {
574 	struct sock *sk = sock->sk;
575 
576 	if (unlikely(inet_send_prepare(sk)))
577 		return -EAGAIN;
578 
579 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
580 			       sk, msg, size);
581 }
582 
583 INDIRECT_CALLABLE_DECLARE(int udpv6_recvmsg(struct sock *, struct msghdr *,
584 					    size_t, int, int, int *));
585 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
586 		  int flags)
587 {
588 	struct sock *sk = sock->sk;
589 	int addr_len = 0;
590 	int err;
591 
592 	if (likely(!(flags & MSG_ERRQUEUE)))
593 		sock_rps_record_flow(sk);
594 
595 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
596 			      sk, msg, size, flags & MSG_DONTWAIT,
597 			      flags & ~MSG_DONTWAIT, &addr_len);
598 	if (err >= 0)
599 		msg->msg_namelen = addr_len;
600 	return err;
601 }
602 
603 const struct proto_ops inet6_stream_ops = {
604 	.family		   = PF_INET6,
605 	.owner		   = THIS_MODULE,
606 	.release	   = inet6_release,
607 	.bind		   = inet6_bind,
608 	.connect	   = inet_stream_connect,	/* ok		*/
609 	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
610 	.accept		   = inet_accept,		/* ok		*/
611 	.getname	   = inet6_getname,
612 	.poll		   = tcp_poll,			/* ok		*/
613 	.ioctl		   = inet6_ioctl,		/* must change  */
614 	.gettstamp	   = sock_gettstamp,
615 	.listen		   = inet_listen,		/* ok		*/
616 	.shutdown	   = inet_shutdown,		/* ok		*/
617 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
618 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
619 	.sendmsg	   = inet6_sendmsg,		/* retpoline's sake */
620 	.recvmsg	   = inet6_recvmsg,		/* retpoline's sake */
621 #ifdef CONFIG_MMU
622 	.mmap		   = tcp_mmap,
623 #endif
624 	.sendpage	   = inet_sendpage,
625 	.sendmsg_locked    = tcp_sendmsg_locked,
626 	.sendpage_locked   = tcp_sendpage_locked,
627 	.splice_read	   = tcp_splice_read,
628 	.read_sock	   = tcp_read_sock,
629 	.peek_len	   = tcp_peek_len,
630 #ifdef CONFIG_COMPAT
631 	.compat_setsockopt = compat_sock_common_setsockopt,
632 	.compat_getsockopt = compat_sock_common_getsockopt,
633 #endif
634 	.set_rcvlowat	   = tcp_set_rcvlowat,
635 };
636 
637 const struct proto_ops inet6_dgram_ops = {
638 	.family		   = PF_INET6,
639 	.owner		   = THIS_MODULE,
640 	.release	   = inet6_release,
641 	.bind		   = inet6_bind,
642 	.connect	   = inet_dgram_connect,	/* ok		*/
643 	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
644 	.accept		   = sock_no_accept,		/* a do nothing	*/
645 	.getname	   = inet6_getname,
646 	.poll		   = udp_poll,			/* ok		*/
647 	.ioctl		   = inet6_ioctl,		/* must change  */
648 	.gettstamp	   = sock_gettstamp,
649 	.listen		   = sock_no_listen,		/* ok		*/
650 	.shutdown	   = inet_shutdown,		/* ok		*/
651 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
652 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
653 	.sendmsg	   = inet6_sendmsg,		/* retpoline's sake */
654 	.recvmsg	   = inet6_recvmsg,		/* retpoline's sake */
655 	.mmap		   = sock_no_mmap,
656 	.sendpage	   = sock_no_sendpage,
657 	.set_peek_off	   = sk_set_peek_off,
658 #ifdef CONFIG_COMPAT
659 	.compat_setsockopt = compat_sock_common_setsockopt,
660 	.compat_getsockopt = compat_sock_common_getsockopt,
661 #endif
662 };
663 
664 static const struct net_proto_family inet6_family_ops = {
665 	.family = PF_INET6,
666 	.create = inet6_create,
667 	.owner	= THIS_MODULE,
668 };
669 
670 int inet6_register_protosw(struct inet_protosw *p)
671 {
672 	struct list_head *lh;
673 	struct inet_protosw *answer;
674 	struct list_head *last_perm;
675 	int protocol = p->protocol;
676 	int ret;
677 
678 	spin_lock_bh(&inetsw6_lock);
679 
680 	ret = -EINVAL;
681 	if (p->type >= SOCK_MAX)
682 		goto out_illegal;
683 
684 	/* If we are trying to override a permanent protocol, bail. */
685 	answer = NULL;
686 	ret = -EPERM;
687 	last_perm = &inetsw6[p->type];
688 	list_for_each(lh, &inetsw6[p->type]) {
689 		answer = list_entry(lh, struct inet_protosw, list);
690 
691 		/* Check only the non-wild match. */
692 		if (INET_PROTOSW_PERMANENT & answer->flags) {
693 			if (protocol == answer->protocol)
694 				break;
695 			last_perm = lh;
696 		}
697 
698 		answer = NULL;
699 	}
700 	if (answer)
701 		goto out_permanent;
702 
703 	/* Add the new entry after the last permanent entry if any, so that
704 	 * the new entry does not override a permanent entry when matched with
705 	 * a wild-card protocol. But it is allowed to override any existing
706 	 * non-permanent entry.  This means that when we remove this entry, the
707 	 * system automatically returns to the old behavior.
708 	 */
709 	list_add_rcu(&p->list, last_perm);
710 	ret = 0;
711 out:
712 	spin_unlock_bh(&inetsw6_lock);
713 	return ret;
714 
715 out_permanent:
716 	pr_err("Attempt to override permanent protocol %d\n", protocol);
717 	goto out;
718 
719 out_illegal:
720 	pr_err("Ignoring attempt to register invalid socket type %d\n",
721 	       p->type);
722 	goto out;
723 }
724 EXPORT_SYMBOL(inet6_register_protosw);
725 
726 void
727 inet6_unregister_protosw(struct inet_protosw *p)
728 {
729 	if (INET_PROTOSW_PERMANENT & p->flags) {
730 		pr_err("Attempt to unregister permanent protocol %d\n",
731 		       p->protocol);
732 	} else {
733 		spin_lock_bh(&inetsw6_lock);
734 		list_del_rcu(&p->list);
735 		spin_unlock_bh(&inetsw6_lock);
736 
737 		synchronize_net();
738 	}
739 }
740 EXPORT_SYMBOL(inet6_unregister_protosw);
741 
742 int inet6_sk_rebuild_header(struct sock *sk)
743 {
744 	struct ipv6_pinfo *np = inet6_sk(sk);
745 	struct dst_entry *dst;
746 
747 	dst = __sk_dst_check(sk, np->dst_cookie);
748 
749 	if (!dst) {
750 		struct inet_sock *inet = inet_sk(sk);
751 		struct in6_addr *final_p, final;
752 		struct flowi6 fl6;
753 
754 		memset(&fl6, 0, sizeof(fl6));
755 		fl6.flowi6_proto = sk->sk_protocol;
756 		fl6.daddr = sk->sk_v6_daddr;
757 		fl6.saddr = np->saddr;
758 		fl6.flowlabel = np->flow_label;
759 		fl6.flowi6_oif = sk->sk_bound_dev_if;
760 		fl6.flowi6_mark = sk->sk_mark;
761 		fl6.fl6_dport = inet->inet_dport;
762 		fl6.fl6_sport = inet->inet_sport;
763 		fl6.flowi6_uid = sk->sk_uid;
764 		security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
765 
766 		rcu_read_lock();
767 		final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt),
768 					 &final);
769 		rcu_read_unlock();
770 
771 		dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
772 		if (IS_ERR(dst)) {
773 			sk->sk_route_caps = 0;
774 			sk->sk_err_soft = -PTR_ERR(dst);
775 			return PTR_ERR(dst);
776 		}
777 
778 		ip6_dst_store(sk, dst, NULL, NULL);
779 	}
780 
781 	return 0;
782 }
783 EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);
784 
785 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
786 		       const struct inet6_skb_parm *opt)
787 {
788 	const struct ipv6_pinfo *np = inet6_sk(sk);
789 
790 	if (np->rxopt.all) {
791 		if (((opt->flags & IP6SKB_HOPBYHOP) &&
792 		     (np->rxopt.bits.hopopts || np->rxopt.bits.ohopopts)) ||
793 		    (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
794 		     np->rxopt.bits.rxflow) ||
795 		    (opt->srcrt && (np->rxopt.bits.srcrt ||
796 		     np->rxopt.bits.osrcrt)) ||
797 		    ((opt->dst1 || opt->dst0) &&
798 		     (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
799 			return true;
800 	}
801 	return false;
802 }
803 EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
804 
805 static struct packet_type ipv6_packet_type __read_mostly = {
806 	.type = cpu_to_be16(ETH_P_IPV6),
807 	.func = ipv6_rcv,
808 	.list_func = ipv6_list_rcv,
809 };
810 
811 static int __init ipv6_packet_init(void)
812 {
813 	dev_add_pack(&ipv6_packet_type);
814 	return 0;
815 }
816 
817 static void ipv6_packet_cleanup(void)
818 {
819 	dev_remove_pack(&ipv6_packet_type);
820 }
821 
822 static int __net_init ipv6_init_mibs(struct net *net)
823 {
824 	int i;
825 
826 	net->mib.udp_stats_in6 = alloc_percpu(struct udp_mib);
827 	if (!net->mib.udp_stats_in6)
828 		return -ENOMEM;
829 	net->mib.udplite_stats_in6 = alloc_percpu(struct udp_mib);
830 	if (!net->mib.udplite_stats_in6)
831 		goto err_udplite_mib;
832 	net->mib.ipv6_statistics = alloc_percpu(struct ipstats_mib);
833 	if (!net->mib.ipv6_statistics)
834 		goto err_ip_mib;
835 
836 	for_each_possible_cpu(i) {
837 		struct ipstats_mib *af_inet6_stats;
838 		af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics, i);
839 		u64_stats_init(&af_inet6_stats->syncp);
840 	}
841 
842 
843 	net->mib.icmpv6_statistics = alloc_percpu(struct icmpv6_mib);
844 	if (!net->mib.icmpv6_statistics)
845 		goto err_icmp_mib;
846 	net->mib.icmpv6msg_statistics = kzalloc(sizeof(struct icmpv6msg_mib),
847 						GFP_KERNEL);
848 	if (!net->mib.icmpv6msg_statistics)
849 		goto err_icmpmsg_mib;
850 	return 0;
851 
852 err_icmpmsg_mib:
853 	free_percpu(net->mib.icmpv6_statistics);
854 err_icmp_mib:
855 	free_percpu(net->mib.ipv6_statistics);
856 err_ip_mib:
857 	free_percpu(net->mib.udplite_stats_in6);
858 err_udplite_mib:
859 	free_percpu(net->mib.udp_stats_in6);
860 	return -ENOMEM;
861 }
862 
863 static void ipv6_cleanup_mibs(struct net *net)
864 {
865 	free_percpu(net->mib.udp_stats_in6);
866 	free_percpu(net->mib.udplite_stats_in6);
867 	free_percpu(net->mib.ipv6_statistics);
868 	free_percpu(net->mib.icmpv6_statistics);
869 	kfree(net->mib.icmpv6msg_statistics);
870 }
871 
872 static int __net_init inet6_net_init(struct net *net)
873 {
874 	int err = 0;
875 
876 	net->ipv6.sysctl.bindv6only = 0;
877 	net->ipv6.sysctl.icmpv6_time = 1*HZ;
878 	net->ipv6.sysctl.icmpv6_echo_ignore_all = 0;
879 	net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0;
880 	net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0;
881 
882 	/* By default, rate limit error messages.
883 	 * Except for pmtu discovery, it would break it.
884 	 * proc_do_large_bitmap needs pointer to the bitmap.
885 	 */
886 	bitmap_set(net->ipv6.sysctl.icmpv6_ratemask, 0, ICMPV6_ERRMSG_MAX + 1);
887 	bitmap_clear(net->ipv6.sysctl.icmpv6_ratemask, ICMPV6_PKT_TOOBIG, 1);
888 	net->ipv6.sysctl.icmpv6_ratemask_ptr = net->ipv6.sysctl.icmpv6_ratemask;
889 
890 	net->ipv6.sysctl.flowlabel_consistency = 1;
891 	net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
892 	net->ipv6.sysctl.idgen_retries = 3;
893 	net->ipv6.sysctl.idgen_delay = 1 * HZ;
894 	net->ipv6.sysctl.flowlabel_state_ranges = 0;
895 	net->ipv6.sysctl.max_dst_opts_cnt = IP6_DEFAULT_MAX_DST_OPTS_CNT;
896 	net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT;
897 	net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN;
898 	net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN;
899 	atomic_set(&net->ipv6.fib6_sernum, 1);
900 
901 	err = ipv6_init_mibs(net);
902 	if (err)
903 		return err;
904 #ifdef CONFIG_PROC_FS
905 	err = udp6_proc_init(net);
906 	if (err)
907 		goto out;
908 	err = tcp6_proc_init(net);
909 	if (err)
910 		goto proc_tcp6_fail;
911 	err = ac6_proc_init(net);
912 	if (err)
913 		goto proc_ac6_fail;
914 #endif
915 	return err;
916 
917 #ifdef CONFIG_PROC_FS
918 proc_ac6_fail:
919 	tcp6_proc_exit(net);
920 proc_tcp6_fail:
921 	udp6_proc_exit(net);
922 out:
923 	ipv6_cleanup_mibs(net);
924 	return err;
925 #endif
926 }
927 
928 static void __net_exit inet6_net_exit(struct net *net)
929 {
930 #ifdef CONFIG_PROC_FS
931 	udp6_proc_exit(net);
932 	tcp6_proc_exit(net);
933 	ac6_proc_exit(net);
934 #endif
935 	ipv6_cleanup_mibs(net);
936 }
937 
938 static struct pernet_operations inet6_net_ops = {
939 	.init = inet6_net_init,
940 	.exit = inet6_net_exit,
941 };
942 
943 static int ipv6_route_input(struct sk_buff *skb)
944 {
945 	ip6_route_input(skb);
946 	return skb_dst(skb)->error;
947 }
948 
949 static const struct ipv6_stub ipv6_stub_impl = {
950 	.ipv6_sock_mc_join = ipv6_sock_mc_join,
951 	.ipv6_sock_mc_drop = ipv6_sock_mc_drop,
952 	.ipv6_dst_lookup_flow = ip6_dst_lookup_flow,
953 	.ipv6_route_input  = ipv6_route_input,
954 	.fib6_get_table	   = fib6_get_table,
955 	.fib6_table_lookup = fib6_table_lookup,
956 	.fib6_lookup       = fib6_lookup,
957 	.fib6_select_path  = fib6_select_path,
958 	.ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
959 	.fib6_nh_init	   = fib6_nh_init,
960 	.fib6_nh_release   = fib6_nh_release,
961 	.fib6_update_sernum = fib6_update_sernum_stub,
962 	.fib6_rt_update	   = fib6_rt_update,
963 	.ip6_del_rt	   = ip6_del_rt,
964 	.udpv6_encap_enable = udpv6_encap_enable,
965 	.ndisc_send_na = ndisc_send_na,
966 	.nd_tbl	= &nd_tbl,
967 };
968 
969 static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
970 	.inet6_bind = __inet6_bind,
971 	.udp6_lib_lookup = __udp6_lib_lookup,
972 };
973 
974 static int __init inet6_init(void)
975 {
976 	struct list_head *r;
977 	int err = 0;
978 
979 	sock_skb_cb_check_size(sizeof(struct inet6_skb_parm));
980 
981 	/* Register the socket-side information for inet6_create.  */
982 	for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
983 		INIT_LIST_HEAD(r);
984 
985 	if (disable_ipv6_mod) {
986 		pr_info("Loaded, but administratively disabled, reboot required to enable\n");
987 		goto out;
988 	}
989 
990 	err = proto_register(&tcpv6_prot, 1);
991 	if (err)
992 		goto out;
993 
994 	err = proto_register(&udpv6_prot, 1);
995 	if (err)
996 		goto out_unregister_tcp_proto;
997 
998 	err = proto_register(&udplitev6_prot, 1);
999 	if (err)
1000 		goto out_unregister_udp_proto;
1001 
1002 	err = proto_register(&rawv6_prot, 1);
1003 	if (err)
1004 		goto out_unregister_udplite_proto;
1005 
1006 	err = proto_register(&pingv6_prot, 1);
1007 	if (err)
1008 		goto out_unregister_raw_proto;
1009 
1010 	/* We MUST register RAW sockets before we create the ICMP6,
1011 	 * IGMP6, or NDISC control sockets.
1012 	 */
1013 	err = rawv6_init();
1014 	if (err)
1015 		goto out_unregister_ping_proto;
1016 
1017 	/* Register the family here so that the init calls below will
1018 	 * be able to create sockets. (?? is this dangerous ??)
1019 	 */
1020 	err = sock_register(&inet6_family_ops);
1021 	if (err)
1022 		goto out_sock_register_fail;
1023 
1024 	/*
1025 	 *	ipngwg API draft makes clear that the correct semantics
1026 	 *	for TCP and UDP is to consider one TCP and UDP instance
1027 	 *	in a host available by both INET and INET6 APIs and
1028 	 *	able to communicate via both network protocols.
1029 	 */
1030 
1031 	err = register_pernet_subsys(&inet6_net_ops);
1032 	if (err)
1033 		goto register_pernet_fail;
1034 	err = ip6_mr_init();
1035 	if (err)
1036 		goto ipmr_fail;
1037 	err = icmpv6_init();
1038 	if (err)
1039 		goto icmp_fail;
1040 	err = ndisc_init();
1041 	if (err)
1042 		goto ndisc_fail;
1043 	err = igmp6_init();
1044 	if (err)
1045 		goto igmp_fail;
1046 
1047 	err = ipv6_netfilter_init();
1048 	if (err)
1049 		goto netfilter_fail;
1050 	/* Create /proc/foo6 entries. */
1051 #ifdef CONFIG_PROC_FS
1052 	err = -ENOMEM;
1053 	if (raw6_proc_init())
1054 		goto proc_raw6_fail;
1055 	if (udplite6_proc_init())
1056 		goto proc_udplite6_fail;
1057 	if (ipv6_misc_proc_init())
1058 		goto proc_misc6_fail;
1059 	if (if6_proc_init())
1060 		goto proc_if6_fail;
1061 #endif
1062 	err = ip6_route_init();
1063 	if (err)
1064 		goto ip6_route_fail;
1065 	err = ndisc_late_init();
1066 	if (err)
1067 		goto ndisc_late_fail;
1068 	err = ip6_flowlabel_init();
1069 	if (err)
1070 		goto ip6_flowlabel_fail;
1071 	err = ipv6_anycast_init();
1072 	if (err)
1073 		goto ipv6_anycast_fail;
1074 	err = addrconf_init();
1075 	if (err)
1076 		goto addrconf_fail;
1077 
1078 	/* Init v6 extension headers. */
1079 	err = ipv6_exthdrs_init();
1080 	if (err)
1081 		goto ipv6_exthdrs_fail;
1082 
1083 	err = ipv6_frag_init();
1084 	if (err)
1085 		goto ipv6_frag_fail;
1086 
1087 	/* Init v6 transport protocols. */
1088 	err = udpv6_init();
1089 	if (err)
1090 		goto udpv6_fail;
1091 
1092 	err = udplitev6_init();
1093 	if (err)
1094 		goto udplitev6_fail;
1095 
1096 	err = udpv6_offload_init();
1097 	if (err)
1098 		goto udpv6_offload_fail;
1099 
1100 	err = tcpv6_init();
1101 	if (err)
1102 		goto tcpv6_fail;
1103 
1104 	err = ipv6_packet_init();
1105 	if (err)
1106 		goto ipv6_packet_fail;
1107 
1108 	err = pingv6_init();
1109 	if (err)
1110 		goto pingv6_fail;
1111 
1112 	err = calipso_init();
1113 	if (err)
1114 		goto calipso_fail;
1115 
1116 	err = seg6_init();
1117 	if (err)
1118 		goto seg6_fail;
1119 
1120 	err = rpl_init();
1121 	if (err)
1122 		goto rpl_fail;
1123 
1124 	err = igmp6_late_init();
1125 	if (err)
1126 		goto igmp6_late_err;
1127 
1128 #ifdef CONFIG_SYSCTL
1129 	err = ipv6_sysctl_register();
1130 	if (err)
1131 		goto sysctl_fail;
1132 #endif
1133 
1134 	/* ensure that ipv6 stubs are visible only after ipv6 is ready */
1135 	wmb();
1136 	ipv6_stub = &ipv6_stub_impl;
1137 	ipv6_bpf_stub = &ipv6_bpf_stub_impl;
1138 out:
1139 	return err;
1140 
1141 #ifdef CONFIG_SYSCTL
1142 sysctl_fail:
1143 	igmp6_late_cleanup();
1144 #endif
1145 igmp6_late_err:
1146 	rpl_exit();
1147 rpl_fail:
1148 	seg6_exit();
1149 seg6_fail:
1150 	calipso_exit();
1151 calipso_fail:
1152 	pingv6_exit();
1153 pingv6_fail:
1154 	ipv6_packet_cleanup();
1155 ipv6_packet_fail:
1156 	tcpv6_exit();
1157 tcpv6_fail:
1158 	udpv6_offload_exit();
1159 udpv6_offload_fail:
1160 	udplitev6_exit();
1161 udplitev6_fail:
1162 	udpv6_exit();
1163 udpv6_fail:
1164 	ipv6_frag_exit();
1165 ipv6_frag_fail:
1166 	ipv6_exthdrs_exit();
1167 ipv6_exthdrs_fail:
1168 	addrconf_cleanup();
1169 addrconf_fail:
1170 	ipv6_anycast_cleanup();
1171 ipv6_anycast_fail:
1172 	ip6_flowlabel_cleanup();
1173 ip6_flowlabel_fail:
1174 	ndisc_late_cleanup();
1175 ndisc_late_fail:
1176 	ip6_route_cleanup();
1177 ip6_route_fail:
1178 #ifdef CONFIG_PROC_FS
1179 	if6_proc_exit();
1180 proc_if6_fail:
1181 	ipv6_misc_proc_exit();
1182 proc_misc6_fail:
1183 	udplite6_proc_exit();
1184 proc_udplite6_fail:
1185 	raw6_proc_exit();
1186 proc_raw6_fail:
1187 #endif
1188 	ipv6_netfilter_fini();
1189 netfilter_fail:
1190 	igmp6_cleanup();
1191 igmp_fail:
1192 	ndisc_cleanup();
1193 ndisc_fail:
1194 	icmpv6_cleanup();
1195 icmp_fail:
1196 	ip6_mr_cleanup();
1197 ipmr_fail:
1198 	unregister_pernet_subsys(&inet6_net_ops);
1199 register_pernet_fail:
1200 	sock_unregister(PF_INET6);
1201 	rtnl_unregister_all(PF_INET6);
1202 out_sock_register_fail:
1203 	rawv6_exit();
1204 out_unregister_ping_proto:
1205 	proto_unregister(&pingv6_prot);
1206 out_unregister_raw_proto:
1207 	proto_unregister(&rawv6_prot);
1208 out_unregister_udplite_proto:
1209 	proto_unregister(&udplitev6_prot);
1210 out_unregister_udp_proto:
1211 	proto_unregister(&udpv6_prot);
1212 out_unregister_tcp_proto:
1213 	proto_unregister(&tcpv6_prot);
1214 	goto out;
1215 }
1216 module_init(inet6_init);
1217 
1218 MODULE_ALIAS_NETPROTO(PF_INET6);
1219