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