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#include <net/compat.h>
64#include <net/xfrm.h>
65#include <net/ioam6.h>
66#include <net/rawv6.h>
67#include <net/rps.h>
68
69#include <linux/uaccess.h>
70#include <linux/mroute6.h>
71
72#include "ip6_offload.h"
73
74MODULE_AUTHOR("Cast of dozens");
75MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
76MODULE_LICENSE("GPL");
77
78/* The inetsw6 table contains everything that inet6_create needs to
79 * build a new socket.
80 */
81static struct list_head inetsw6[SOCK_MAX];
82static DEFINE_SPINLOCK(inetsw6_lock);
83
84struct ipv6_params ipv6_defaults = {
85 .disable_ipv6 = 0,
86 .autoconf = 1,
87};
88
89static int disable_ipv6_mod;
90
91module_param_named(disable, disable_ipv6_mod, int, 0444);
92MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
93
94module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
95MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
96
97module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
98MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");
99
100bool ipv6_mod_enabled(void)
101{
102 return disable_ipv6_mod == 0;
103}
104EXPORT_SYMBOL_GPL(ipv6_mod_enabled);
105
106static struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
107{
108 const int offset = sk->sk_prot->ipv6_pinfo_offset;
109
110 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
111}
112
113void inet6_sock_destruct(struct sock *sk)
114{
115 inet6_cleanup_sock(sk);
116 inet_sock_destruct(sk);
117}
118EXPORT_SYMBOL_GPL(inet6_sock_destruct);
119
120static int inet6_create(struct net *net, struct socket *sock, int protocol,
121 int kern)
122{
123 struct inet_sock *inet;
124 struct ipv6_pinfo *np;
125 struct sock *sk;
126 struct inet_protosw *answer;
127 struct proto *answer_prot;
128 unsigned char answer_flags;
129 int try_loading_module = 0;
130 int err;
131
132 if (protocol < 0 || protocol >= IPPROTO_MAX)
133 return -EINVAL;
134
135 /* Look for the requested type/protocol pair. */
136lookup_protocol:
137 err = -ESOCKTNOSUPPORT;
138 rcu_read_lock();
139 list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
140
141 err = 0;
142 /* Check the non-wild match. */
143 if (protocol == answer->protocol) {
144 if (protocol != IPPROTO_IP)
145 break;
146 } else {
147 /* Check for the two wild cases. */
148 if (IPPROTO_IP == protocol) {
149 protocol = answer->protocol;
150 break;
151 }
152 if (IPPROTO_IP == answer->protocol)
153 break;
154 }
155 err = -EPROTONOSUPPORT;
156 }
157
158 if (err) {
159 if (try_loading_module < 2) {
160 rcu_read_unlock();
161 /*
162 * Be more specific, e.g. net-pf-10-proto-132-type-1
163 * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
164 */
165 if (++try_loading_module == 1)
166 request_module("net-pf-%d-proto-%d-type-%d",
167 PF_INET6, protocol, sock->type);
168 /*
169 * Fall back to generic, e.g. net-pf-10-proto-132
170 * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
171 */
172 else
173 request_module("net-pf-%d-proto-%d",
174 PF_INET6, protocol);
175 goto lookup_protocol;
176 } else
177 goto out_rcu_unlock;
178 }
179
180 err = -EPERM;
181 if (sock->type == SOCK_RAW && !kern &&
182 !ns_capable(ns: net->user_ns, CAP_NET_RAW))
183 goto out_rcu_unlock;
184
185 sock->ops = answer->ops;
186 answer_prot = answer->prot;
187 answer_flags = answer->flags;
188 rcu_read_unlock();
189
190 WARN_ON(!answer_prot->slab);
191
192 err = -ENOBUFS;
193 sk = sk_alloc(net, PF_INET6, GFP_KERNEL, prot: answer_prot, kern);
194 if (!sk)
195 goto out;
196
197 sock_init_data(sock, sk);
198
199 err = 0;
200 if (INET_PROTOSW_REUSE & answer_flags)
201 sk->sk_reuse = SK_CAN_REUSE;
202
203 if (INET_PROTOSW_ICSK & answer_flags)
204 inet_init_csk_locks(sk);
205
206 inet = inet_sk(sk);
207 inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
208
209 if (SOCK_RAW == sock->type) {
210 inet->inet_num = protocol;
211 if (IPPROTO_RAW == protocol)
212 inet_set_bit(HDRINCL, sk);
213 }
214
215 sk->sk_destruct = inet6_sock_destruct;
216 sk->sk_family = PF_INET6;
217 sk->sk_protocol = protocol;
218
219 sk->sk_backlog_rcv = answer->prot->backlog_rcv;
220
221 inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
222 np->hop_limit = -1;
223 np->mcast_hops = IPV6_DEFAULT_MCASTHOPS;
224 inet6_set_bit(MC6_LOOP, sk);
225 inet6_set_bit(MC6_ALL, sk);
226 np->pmtudisc = IPV6_PMTUDISC_WANT;
227 inet6_assign_bit(REPFLOW, sk, net->ipv6.sysctl.flowlabel_reflect &
228 FLOWLABEL_REFLECT_ESTABLISHED);
229 sk->sk_ipv6only = net->ipv6.sysctl.bindv6only;
230 sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
231
232 /* Init the ipv4 part of the socket since we can have sockets
233 * using v6 API for ipv4.
234 */
235 inet->uc_ttl = -1;
236
237 inet_set_bit(MC_LOOP, sk);
238 inet->mc_ttl = 1;
239 inet->mc_index = 0;
240 RCU_INIT_POINTER(inet->mc_list, NULL);
241 inet->rcv_tos = 0;
242
243 if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
244 inet->pmtudisc = IP_PMTUDISC_DONT;
245 else
246 inet->pmtudisc = IP_PMTUDISC_WANT;
247
248 if (inet->inet_num) {
249 /* It assumes that any protocol which allows
250 * the user to assign a number at socket
251 * creation time automatically shares.
252 */
253 inet->inet_sport = htons(inet->inet_num);
254 err = sk->sk_prot->hash(sk);
255 if (err) {
256 sk_common_release(sk);
257 goto out;
258 }
259 }
260 if (sk->sk_prot->init) {
261 err = sk->sk_prot->init(sk);
262 if (err) {
263 sk_common_release(sk);
264 goto out;
265 }
266 }
267
268 if (!kern) {
269 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
270 if (err) {
271 sk_common_release(sk);
272 goto out;
273 }
274 }
275out:
276 return err;
277out_rcu_unlock:
278 rcu_read_unlock();
279 goto out;
280}
281
282static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
283 u32 flags)
284{
285 struct sockaddr_in6 *addr = (struct sockaddr_in6 *)uaddr;
286 struct inet_sock *inet = inet_sk(sk);
287 struct ipv6_pinfo *np = inet6_sk(sk: sk);
288 struct net *net = sock_net(sk);
289 __be32 v4addr = 0;
290 unsigned short snum;
291 bool saved_ipv6only;
292 int addr_type = 0;
293 int err = 0;
294
295 if (addr->sin6_family != AF_INET6)
296 return -EAFNOSUPPORT;
297
298 addr_type = ipv6_addr_type(addr: &addr->sin6_addr);
299 if ((addr_type & IPV6_ADDR_MULTICAST) && sk->sk_type == SOCK_STREAM)
300 return -EINVAL;
301
302 snum = ntohs(addr->sin6_port);
303 if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
304 snum && inet_port_requires_bind_service(net, port: snum) &&
305 !ns_capable(ns: net->user_ns, CAP_NET_BIND_SERVICE))
306 return -EACCES;
307
308 if (flags & BIND_WITH_LOCK)
309 lock_sock(sk);
310
311 /* Check these errors (active socket, double bind). */
312 if (sk->sk_state != TCP_CLOSE || inet->inet_num) {
313 err = -EINVAL;
314 goto out;
315 }
316
317 /* Check if the address belongs to the host. */
318 if (addr_type == IPV6_ADDR_MAPPED) {
319 struct net_device *dev = NULL;
320 int chk_addr_ret;
321
322 /* Binding to v4-mapped address on a v6-only socket
323 * makes no sense
324 */
325 if (ipv6_only_sock(sk)) {
326 err = -EINVAL;
327 goto out;
328 }
329
330 rcu_read_lock();
331 if (sk->sk_bound_dev_if) {
332 dev = dev_get_by_index_rcu(net, ifindex: sk->sk_bound_dev_if);
333 if (!dev) {
334 err = -ENODEV;
335 goto out_unlock;
336 }
337 }
338
339 /* Reproduce AF_INET checks to make the bindings consistent */
340 v4addr = addr->sin6_addr.s6_addr32[3];
341 chk_addr_ret = inet_addr_type_dev_table(net, dev, addr: v4addr);
342 rcu_read_unlock();
343
344 if (!inet_addr_valid_or_nonlocal(net, inet, addr: v4addr,
345 addr_type: chk_addr_ret)) {
346 err = -EADDRNOTAVAIL;
347 goto out;
348 }
349 } else {
350 if (addr_type != IPV6_ADDR_ANY) {
351 struct net_device *dev = NULL;
352
353 rcu_read_lock();
354 if (__ipv6_addr_needs_scope_id(type: addr_type)) {
355 if (addr_len >= sizeof(struct sockaddr_in6) &&
356 addr->sin6_scope_id) {
357 /* Override any existing binding, if another one
358 * is supplied by user.
359 */
360 sk->sk_bound_dev_if = addr->sin6_scope_id;
361 }
362
363 /* Binding to link-local address requires an interface */
364 if (!sk->sk_bound_dev_if) {
365 err = -EINVAL;
366 goto out_unlock;
367 }
368 }
369
370 if (sk->sk_bound_dev_if) {
371 dev = dev_get_by_index_rcu(net, ifindex: sk->sk_bound_dev_if);
372 if (!dev) {
373 err = -ENODEV;
374 goto out_unlock;
375 }
376 }
377
378 /* ipv4 addr of the socket is invalid. Only the
379 * unspecified and mapped address have a v4 equivalent.
380 */
381 v4addr = LOOPBACK4_IPV6;
382 if (!(addr_type & IPV6_ADDR_MULTICAST)) {
383 if (!ipv6_can_nonlocal_bind(net, inet) &&
384 !ipv6_chk_addr(net, addr: &addr->sin6_addr,
385 dev, strict: 0)) {
386 err = -EADDRNOTAVAIL;
387 goto out_unlock;
388 }
389 }
390 rcu_read_unlock();
391 }
392 }
393
394 inet->inet_rcv_saddr = v4addr;
395 inet->inet_saddr = v4addr;
396
397 sk->sk_v6_rcv_saddr = addr->sin6_addr;
398
399 if (!(addr_type & IPV6_ADDR_MULTICAST))
400 np->saddr = addr->sin6_addr;
401
402 saved_ipv6only = sk->sk_ipv6only;
403 if (addr_type != IPV6_ADDR_ANY && addr_type != IPV6_ADDR_MAPPED)
404 sk->sk_ipv6only = 1;
405
406 /* Make sure we are allowed to bind here. */
407 if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
408 (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
409 err = sk->sk_prot->get_port(sk, snum);
410 if (err) {
411 sk->sk_ipv6only = saved_ipv6only;
412 inet_reset_saddr(sk);
413 goto out;
414 }
415 if (!(flags & BIND_FROM_BPF)) {
416 err = BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk);
417 if (err) {
418 sk->sk_ipv6only = saved_ipv6only;
419 inet_reset_saddr(sk);
420 if (sk->sk_prot->put_port)
421 sk->sk_prot->put_port(sk);
422 goto out;
423 }
424 }
425 }
426
427 if (addr_type != IPV6_ADDR_ANY)
428 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
429 if (snum)
430 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
431 inet->inet_sport = htons(inet->inet_num);
432 inet->inet_dport = 0;
433 inet->inet_daddr = 0;
434out:
435 if (flags & BIND_WITH_LOCK)
436 release_sock(sk);
437 return err;
438out_unlock:
439 rcu_read_unlock();
440 goto out;
441}
442
443int inet6_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
444{
445 u32 flags = BIND_WITH_LOCK;
446 const struct proto *prot;
447 int err = 0;
448
449 /* IPV6_ADDRFORM can change sk->sk_prot under us. */
450 prot = READ_ONCE(sk->sk_prot);
451 /* If the socket has its own bind function then use it. */
452 if (prot->bind)
453 return prot->bind(sk, uaddr, addr_len);
454
455 if (addr_len < SIN6_LEN_RFC2133)
456 return -EINVAL;
457
458 /* BPF prog is run before any checks are done so that if the prog
459 * changes context in a wrong way it will be caught.
460 */
461 err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len,
462 CGROUP_INET6_BIND, &flags);
463 if (err)
464 return err;
465
466 return __inet6_bind(sk, uaddr, addr_len, flags);
467}
468
469/* bind for INET6 API */
470int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
471{
472 return inet6_bind_sk(sk: sock->sk, uaddr, addr_len);
473}
474EXPORT_SYMBOL(inet6_bind);
475
476int inet6_release(struct socket *sock)
477{
478 struct sock *sk = sock->sk;
479
480 if (!sk)
481 return -EINVAL;
482
483 /* Free mc lists */
484 ipv6_sock_mc_close(sk);
485
486 /* Free ac lists */
487 ipv6_sock_ac_close(sk);
488
489 return inet_release(sock);
490}
491EXPORT_SYMBOL(inet6_release);
492
493void inet6_cleanup_sock(struct sock *sk)
494{
495 struct ipv6_pinfo *np = inet6_sk(sk: sk);
496 struct sk_buff *skb;
497 struct ipv6_txoptions *opt;
498
499 /* Release rx options */
500
501 skb = xchg(&np->pktoptions, NULL);
502 kfree_skb(skb);
503
504 skb = xchg(&np->rxpmtu, NULL);
505 kfree_skb(skb);
506
507 /* Free flowlabels */
508 fl6_free_socklist(sk);
509
510 /* Free tx options */
511
512 opt = xchg((__force struct ipv6_txoptions **)&np->opt, NULL);
513 if (opt) {
514 atomic_sub(i: opt->tot_len, v: &sk->sk_omem_alloc);
515 txopt_put(opt);
516 }
517}
518EXPORT_SYMBOL_GPL(inet6_cleanup_sock);
519
520/*
521 * This does both peername and sockname.
522 */
523int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
524 int peer)
525{
526 struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr;
527 int sin_addr_len = sizeof(*sin);
528 struct sock *sk = sock->sk;
529 struct inet_sock *inet = inet_sk(sk);
530 struct ipv6_pinfo *np = inet6_sk(sk: sk);
531
532 sin->sin6_family = AF_INET6;
533 sin->sin6_flowinfo = 0;
534 sin->sin6_scope_id = 0;
535 lock_sock(sk);
536 if (peer) {
537 if (!inet->inet_dport ||
538 (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
539 peer == 1)) {
540 release_sock(sk);
541 return -ENOTCONN;
542 }
543 sin->sin6_port = inet->inet_dport;
544 sin->sin6_addr = sk->sk_v6_daddr;
545 if (inet6_test_bit(SNDFLOW, sk))
546 sin->sin6_flowinfo = np->flow_label;
547 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
548 CGROUP_INET6_GETPEERNAME);
549 } else {
550 if (ipv6_addr_any(a: &sk->sk_v6_rcv_saddr))
551 sin->sin6_addr = np->saddr;
552 else
553 sin->sin6_addr = sk->sk_v6_rcv_saddr;
554 sin->sin6_port = inet->inet_sport;
555 BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
556 CGROUP_INET6_GETSOCKNAME);
557 }
558 sin->sin6_scope_id = ipv6_iface_scope_id(addr: &sin->sin6_addr,
559 iface: sk->sk_bound_dev_if);
560 release_sock(sk);
561 return sin_addr_len;
562}
563EXPORT_SYMBOL(inet6_getname);
564
565int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
566{
567 void __user *argp = (void __user *)arg;
568 struct sock *sk = sock->sk;
569 struct net *net = sock_net(sk);
570 const struct proto *prot;
571
572 switch (cmd) {
573 case SIOCADDRT:
574 case SIOCDELRT: {
575 struct in6_rtmsg rtmsg;
576
577 if (copy_from_user(to: &rtmsg, from: argp, n: sizeof(rtmsg)))
578 return -EFAULT;
579 return ipv6_route_ioctl(net, cmd, rtmsg: &rtmsg);
580 }
581 case SIOCSIFADDR:
582 return addrconf_add_ifaddr(net, arg: argp);
583 case SIOCDIFADDR:
584 return addrconf_del_ifaddr(net, arg: argp);
585 case SIOCSIFDSTADDR:
586 return addrconf_set_dstaddr(net, arg: argp);
587 default:
588 /* IPV6_ADDRFORM can change sk->sk_prot under us. */
589 prot = READ_ONCE(sk->sk_prot);
590 if (!prot->ioctl)
591 return -ENOIOCTLCMD;
592 return sk_ioctl(sk, cmd, arg: (void __user *)arg);
593 }
594 /*NOTREACHED*/
595 return 0;
596}
597EXPORT_SYMBOL(inet6_ioctl);
598
599#ifdef CONFIG_COMPAT
600struct compat_in6_rtmsg {
601 struct in6_addr rtmsg_dst;
602 struct in6_addr rtmsg_src;
603 struct in6_addr rtmsg_gateway;
604 u32 rtmsg_type;
605 u16 rtmsg_dst_len;
606 u16 rtmsg_src_len;
607 u32 rtmsg_metric;
608 u32 rtmsg_info;
609 u32 rtmsg_flags;
610 s32 rtmsg_ifindex;
611};
612
613static int inet6_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
614 struct compat_in6_rtmsg __user *ur)
615{
616 struct in6_rtmsg rt;
617
618 if (copy_from_user(to: &rt.rtmsg_dst, from: &ur->rtmsg_dst,
619 n: 3 * sizeof(struct in6_addr)) ||
620 get_user(rt.rtmsg_type, &ur->rtmsg_type) ||
621 get_user(rt.rtmsg_dst_len, &ur->rtmsg_dst_len) ||
622 get_user(rt.rtmsg_src_len, &ur->rtmsg_src_len) ||
623 get_user(rt.rtmsg_metric, &ur->rtmsg_metric) ||
624 get_user(rt.rtmsg_info, &ur->rtmsg_info) ||
625 get_user(rt.rtmsg_flags, &ur->rtmsg_flags) ||
626 get_user(rt.rtmsg_ifindex, &ur->rtmsg_ifindex))
627 return -EFAULT;
628
629
630 return ipv6_route_ioctl(net: sock_net(sk), cmd, rtmsg: &rt);
631}
632
633int inet6_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
634{
635 void __user *argp = compat_ptr(uptr: arg);
636 struct sock *sk = sock->sk;
637
638 switch (cmd) {
639 case SIOCADDRT:
640 case SIOCDELRT:
641 return inet6_compat_routing_ioctl(sk, cmd, ur: argp);
642 default:
643 return -ENOIOCTLCMD;
644 }
645}
646EXPORT_SYMBOL_GPL(inet6_compat_ioctl);
647#endif /* CONFIG_COMPAT */
648
649INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
650 size_t));
651int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
652{
653 struct sock *sk = sock->sk;
654 const struct proto *prot;
655
656 if (unlikely(inet_send_prepare(sk)))
657 return -EAGAIN;
658
659 /* IPV6_ADDRFORM can change sk->sk_prot under us. */
660 prot = READ_ONCE(sk->sk_prot);
661 return INDIRECT_CALL_2(prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
662 sk, msg, size);
663}
664
665INDIRECT_CALLABLE_DECLARE(int udpv6_recvmsg(struct sock *, struct msghdr *,
666 size_t, int, int *));
667int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
668 int flags)
669{
670 struct sock *sk = sock->sk;
671 const struct proto *prot;
672 int addr_len = 0;
673 int err;
674
675 if (likely(!(flags & MSG_ERRQUEUE)))
676 sock_rps_record_flow(sk);
677
678 /* IPV6_ADDRFORM can change sk->sk_prot under us. */
679 prot = READ_ONCE(sk->sk_prot);
680 err = INDIRECT_CALL_2(prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
681 sk, msg, size, flags, &addr_len);
682 if (err >= 0)
683 msg->msg_namelen = addr_len;
684 return err;
685}
686
687const struct proto_ops inet6_stream_ops = {
688 .family = PF_INET6,
689 .owner = THIS_MODULE,
690 .release = inet6_release,
691 .bind = inet6_bind,
692 .connect = inet_stream_connect, /* ok */
693 .socketpair = sock_no_socketpair, /* a do nothing */
694 .accept = inet_accept, /* ok */
695 .getname = inet6_getname,
696 .poll = tcp_poll, /* ok */
697 .ioctl = inet6_ioctl, /* must change */
698 .gettstamp = sock_gettstamp,
699 .listen = inet_listen, /* ok */
700 .shutdown = inet_shutdown, /* ok */
701 .setsockopt = sock_common_setsockopt, /* ok */
702 .getsockopt = sock_common_getsockopt, /* ok */
703 .sendmsg = inet6_sendmsg, /* retpoline's sake */
704 .recvmsg = inet6_recvmsg, /* retpoline's sake */
705#ifdef CONFIG_MMU
706 .mmap = tcp_mmap,
707#endif
708 .splice_eof = inet_splice_eof,
709 .sendmsg_locked = tcp_sendmsg_locked,
710 .splice_read = tcp_splice_read,
711 .read_sock = tcp_read_sock,
712 .read_skb = tcp_read_skb,
713 .peek_len = tcp_peek_len,
714#ifdef CONFIG_COMPAT
715 .compat_ioctl = inet6_compat_ioctl,
716#endif
717 .set_rcvlowat = tcp_set_rcvlowat,
718};
719
720const struct proto_ops inet6_dgram_ops = {
721 .family = PF_INET6,
722 .owner = THIS_MODULE,
723 .release = inet6_release,
724 .bind = inet6_bind,
725 .connect = inet_dgram_connect, /* ok */
726 .socketpair = sock_no_socketpair, /* a do nothing */
727 .accept = sock_no_accept, /* a do nothing */
728 .getname = inet6_getname,
729 .poll = udp_poll, /* ok */
730 .ioctl = inet6_ioctl, /* must change */
731 .gettstamp = sock_gettstamp,
732 .listen = sock_no_listen, /* ok */
733 .shutdown = inet_shutdown, /* ok */
734 .setsockopt = sock_common_setsockopt, /* ok */
735 .getsockopt = sock_common_getsockopt, /* ok */
736 .sendmsg = inet6_sendmsg, /* retpoline's sake */
737 .recvmsg = inet6_recvmsg, /* retpoline's sake */
738 .read_skb = udp_read_skb,
739 .mmap = sock_no_mmap,
740 .set_peek_off = udp_set_peek_off,
741#ifdef CONFIG_COMPAT
742 .compat_ioctl = inet6_compat_ioctl,
743#endif
744};
745
746static const struct net_proto_family inet6_family_ops = {
747 .family = PF_INET6,
748 .create = inet6_create,
749 .owner = THIS_MODULE,
750};
751
752int inet6_register_protosw(struct inet_protosw *p)
753{
754 struct list_head *lh;
755 struct inet_protosw *answer;
756 struct list_head *last_perm;
757 int protocol = p->protocol;
758 int ret;
759
760 spin_lock_bh(lock: &inetsw6_lock);
761
762 ret = -EINVAL;
763 if (p->type >= SOCK_MAX)
764 goto out_illegal;
765
766 /* If we are trying to override a permanent protocol, bail. */
767 answer = NULL;
768 ret = -EPERM;
769 last_perm = &inetsw6[p->type];
770 list_for_each(lh, &inetsw6[p->type]) {
771 answer = list_entry(lh, struct inet_protosw, list);
772
773 /* Check only the non-wild match. */
774 if (INET_PROTOSW_PERMANENT & answer->flags) {
775 if (protocol == answer->protocol)
776 break;
777 last_perm = lh;
778 }
779
780 answer = NULL;
781 }
782 if (answer)
783 goto out_permanent;
784
785 /* Add the new entry after the last permanent entry if any, so that
786 * the new entry does not override a permanent entry when matched with
787 * a wild-card protocol. But it is allowed to override any existing
788 * non-permanent entry. This means that when we remove this entry, the
789 * system automatically returns to the old behavior.
790 */
791 list_add_rcu(new: &p->list, head: last_perm);
792 ret = 0;
793out:
794 spin_unlock_bh(lock: &inetsw6_lock);
795 return ret;
796
797out_permanent:
798 pr_err("Attempt to override permanent protocol %d\n", protocol);
799 goto out;
800
801out_illegal:
802 pr_err("Ignoring attempt to register invalid socket type %d\n",
803 p->type);
804 goto out;
805}
806EXPORT_SYMBOL(inet6_register_protosw);
807
808void
809inet6_unregister_protosw(struct inet_protosw *p)
810{
811 if (INET_PROTOSW_PERMANENT & p->flags) {
812 pr_err("Attempt to unregister permanent protocol %d\n",
813 p->protocol);
814 } else {
815 spin_lock_bh(lock: &inetsw6_lock);
816 list_del_rcu(entry: &p->list);
817 spin_unlock_bh(lock: &inetsw6_lock);
818
819 synchronize_net();
820 }
821}
822EXPORT_SYMBOL(inet6_unregister_protosw);
823
824int inet6_sk_rebuild_header(struct sock *sk)
825{
826 struct ipv6_pinfo *np = inet6_sk(sk: sk);
827 struct dst_entry *dst;
828
829 dst = __sk_dst_check(sk, cookie: np->dst_cookie);
830
831 if (!dst) {
832 struct inet_sock *inet = inet_sk(sk);
833 struct in6_addr *final_p, final;
834 struct flowi6 fl6;
835
836 memset(&fl6, 0, sizeof(fl6));
837 fl6.flowi6_proto = sk->sk_protocol;
838 fl6.daddr = sk->sk_v6_daddr;
839 fl6.saddr = np->saddr;
840 fl6.flowlabel = np->flow_label;
841 fl6.flowi6_oif = sk->sk_bound_dev_if;
842 fl6.flowi6_mark = sk->sk_mark;
843 fl6.fl6_dport = inet->inet_dport;
844 fl6.fl6_sport = inet->inet_sport;
845 fl6.flowi6_uid = sk->sk_uid;
846 security_sk_classify_flow(sk, flic: flowi6_to_flowi_common(fl6: &fl6));
847
848 rcu_read_lock();
849 final_p = fl6_update_dst(fl6: &fl6, rcu_dereference(np->opt),
850 orig: &final);
851 rcu_read_unlock();
852
853 dst = ip6_dst_lookup_flow(net: sock_net(sk), sk, fl6: &fl6, final_dst: final_p);
854 if (IS_ERR(ptr: dst)) {
855 sk->sk_route_caps = 0;
856 WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst));
857 return PTR_ERR(ptr: dst);
858 }
859
860 ip6_dst_store(sk, dst, NULL, NULL);
861 }
862
863 return 0;
864}
865EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);
866
867bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
868 const struct inet6_skb_parm *opt)
869{
870 const struct ipv6_pinfo *np = inet6_sk(sk: sk);
871
872 if (np->rxopt.all) {
873 if (((opt->flags & IP6SKB_HOPBYHOP) &&
874 (np->rxopt.bits.hopopts || np->rxopt.bits.ohopopts)) ||
875 (ip6_flowinfo(hdr: (struct ipv6hdr *) skb_network_header(skb)) &&
876 np->rxopt.bits.rxflow) ||
877 (opt->srcrt && (np->rxopt.bits.srcrt ||
878 np->rxopt.bits.osrcrt)) ||
879 ((opt->dst1 || opt->dst0) &&
880 (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
881 return true;
882 }
883 return false;
884}
885EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
886
887static struct packet_type ipv6_packet_type __read_mostly = {
888 .type = cpu_to_be16(ETH_P_IPV6),
889 .func = ipv6_rcv,
890 .list_func = ipv6_list_rcv,
891};
892
893static int __init ipv6_packet_init(void)
894{
895 dev_add_pack(pt: &ipv6_packet_type);
896 return 0;
897}
898
899static void ipv6_packet_cleanup(void)
900{
901 dev_remove_pack(pt: &ipv6_packet_type);
902}
903
904static int __net_init ipv6_init_mibs(struct net *net)
905{
906 int i;
907
908 net->mib.udp_stats_in6 = alloc_percpu(struct udp_mib);
909 if (!net->mib.udp_stats_in6)
910 return -ENOMEM;
911 net->mib.udplite_stats_in6 = alloc_percpu(struct udp_mib);
912 if (!net->mib.udplite_stats_in6)
913 goto err_udplite_mib;
914 net->mib.ipv6_statistics = alloc_percpu(struct ipstats_mib);
915 if (!net->mib.ipv6_statistics)
916 goto err_ip_mib;
917
918 for_each_possible_cpu(i) {
919 struct ipstats_mib *af_inet6_stats;
920 af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics, i);
921 u64_stats_init(syncp: &af_inet6_stats->syncp);
922 }
923
924
925 net->mib.icmpv6_statistics = alloc_percpu(struct icmpv6_mib);
926 if (!net->mib.icmpv6_statistics)
927 goto err_icmp_mib;
928 net->mib.icmpv6msg_statistics = kzalloc(size: sizeof(struct icmpv6msg_mib),
929 GFP_KERNEL);
930 if (!net->mib.icmpv6msg_statistics)
931 goto err_icmpmsg_mib;
932 return 0;
933
934err_icmpmsg_mib:
935 free_percpu(pdata: net->mib.icmpv6_statistics);
936err_icmp_mib:
937 free_percpu(pdata: net->mib.ipv6_statistics);
938err_ip_mib:
939 free_percpu(pdata: net->mib.udplite_stats_in6);
940err_udplite_mib:
941 free_percpu(pdata: net->mib.udp_stats_in6);
942 return -ENOMEM;
943}
944
945static void ipv6_cleanup_mibs(struct net *net)
946{
947 free_percpu(pdata: net->mib.udp_stats_in6);
948 free_percpu(pdata: net->mib.udplite_stats_in6);
949 free_percpu(pdata: net->mib.ipv6_statistics);
950 free_percpu(pdata: net->mib.icmpv6_statistics);
951 kfree(objp: net->mib.icmpv6msg_statistics);
952}
953
954static int __net_init inet6_net_init(struct net *net)
955{
956 int err = 0;
957
958 net->ipv6.sysctl.bindv6only = 0;
959 net->ipv6.sysctl.icmpv6_time = 1*HZ;
960 net->ipv6.sysctl.icmpv6_echo_ignore_all = 0;
961 net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0;
962 net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0;
963 net->ipv6.sysctl.icmpv6_error_anycast_as_unicast = 0;
964
965 /* By default, rate limit error messages.
966 * Except for pmtu discovery, it would break it.
967 * proc_do_large_bitmap needs pointer to the bitmap.
968 */
969 bitmap_set(map: net->ipv6.sysctl.icmpv6_ratemask, start: 0, ICMPV6_ERRMSG_MAX + 1);
970 bitmap_clear(map: net->ipv6.sysctl.icmpv6_ratemask, ICMPV6_PKT_TOOBIG, nbits: 1);
971 net->ipv6.sysctl.icmpv6_ratemask_ptr = net->ipv6.sysctl.icmpv6_ratemask;
972
973 net->ipv6.sysctl.flowlabel_consistency = 1;
974 net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
975 net->ipv6.sysctl.idgen_retries = 3;
976 net->ipv6.sysctl.idgen_delay = 1 * HZ;
977 net->ipv6.sysctl.flowlabel_state_ranges = 0;
978 net->ipv6.sysctl.max_dst_opts_cnt = IP6_DEFAULT_MAX_DST_OPTS_CNT;
979 net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT;
980 net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN;
981 net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN;
982 net->ipv6.sysctl.fib_notify_on_flag_change = 0;
983 atomic_set(v: &net->ipv6.fib6_sernum, i: 1);
984
985 net->ipv6.sysctl.ioam6_id = IOAM6_DEFAULT_ID;
986 net->ipv6.sysctl.ioam6_id_wide = IOAM6_DEFAULT_ID_WIDE;
987
988 err = ipv6_init_mibs(net);
989 if (err)
990 return err;
991#ifdef CONFIG_PROC_FS
992 err = udp6_proc_init(net);
993 if (err)
994 goto out;
995 err = tcp6_proc_init(net);
996 if (err)
997 goto proc_tcp6_fail;
998 err = ac6_proc_init(net);
999 if (err)
1000 goto proc_ac6_fail;
1001#endif
1002 return err;
1003
1004#ifdef CONFIG_PROC_FS
1005proc_ac6_fail:
1006 tcp6_proc_exit(net);
1007proc_tcp6_fail:
1008 udp6_proc_exit(net);
1009out:
1010 ipv6_cleanup_mibs(net);
1011 return err;
1012#endif
1013}
1014
1015static void __net_exit inet6_net_exit(struct net *net)
1016{
1017#ifdef CONFIG_PROC_FS
1018 udp6_proc_exit(net);
1019 tcp6_proc_exit(net);
1020 ac6_proc_exit(net);
1021#endif
1022 ipv6_cleanup_mibs(net);
1023}
1024
1025static struct pernet_operations inet6_net_ops = {
1026 .init = inet6_net_init,
1027 .exit = inet6_net_exit,
1028};
1029
1030static int ipv6_route_input(struct sk_buff *skb)
1031{
1032 ip6_route_input(skb);
1033 return skb_dst(skb)->error;
1034}
1035
1036static const struct ipv6_stub ipv6_stub_impl = {
1037 .ipv6_sock_mc_join = ipv6_sock_mc_join,
1038 .ipv6_sock_mc_drop = ipv6_sock_mc_drop,
1039 .ipv6_dst_lookup_flow = ip6_dst_lookup_flow,
1040 .ipv6_route_input = ipv6_route_input,
1041 .fib6_get_table = fib6_get_table,
1042 .fib6_table_lookup = fib6_table_lookup,
1043 .fib6_lookup = fib6_lookup,
1044 .fib6_select_path = fib6_select_path,
1045 .ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
1046 .fib6_nh_init = fib6_nh_init,
1047 .fib6_nh_release = fib6_nh_release,
1048 .fib6_nh_release_dsts = fib6_nh_release_dsts,
1049 .fib6_update_sernum = fib6_update_sernum_stub,
1050 .fib6_rt_update = fib6_rt_update,
1051 .ip6_del_rt = ip6_del_rt,
1052 .udpv6_encap_enable = udpv6_encap_enable,
1053 .ndisc_send_na = ndisc_send_na,
1054#if IS_ENABLED(CONFIG_XFRM)
1055 .xfrm6_local_rxpmtu = xfrm6_local_rxpmtu,
1056 .xfrm6_udp_encap_rcv = xfrm6_udp_encap_rcv,
1057 .xfrm6_gro_udp_encap_rcv = xfrm6_gro_udp_encap_rcv,
1058 .xfrm6_rcv_encap = xfrm6_rcv_encap,
1059#endif
1060 .nd_tbl = &nd_tbl,
1061 .ipv6_fragment = ip6_fragment,
1062 .ipv6_dev_find = ipv6_dev_find,
1063};
1064
1065static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
1066 .inet6_bind = __inet6_bind,
1067 .udp6_lib_lookup = __udp6_lib_lookup,
1068 .ipv6_setsockopt = do_ipv6_setsockopt,
1069 .ipv6_getsockopt = do_ipv6_getsockopt,
1070 .ipv6_dev_get_saddr = ipv6_dev_get_saddr,
1071};
1072
1073static int __init inet6_init(void)
1074{
1075 struct list_head *r;
1076 int err = 0;
1077
1078 sock_skb_cb_check_size(sizeof(struct inet6_skb_parm));
1079
1080 /* Register the socket-side information for inet6_create. */
1081 for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
1082 INIT_LIST_HEAD(list: r);
1083
1084 raw_hashinfo_init(hashinfo: &raw_v6_hashinfo);
1085
1086 if (disable_ipv6_mod) {
1087 pr_info("Loaded, but administratively disabled, reboot required to enable\n");
1088 goto out;
1089 }
1090
1091 err = proto_register(prot: &tcpv6_prot, alloc_slab: 1);
1092 if (err)
1093 goto out;
1094
1095 err = proto_register(prot: &udpv6_prot, alloc_slab: 1);
1096 if (err)
1097 goto out_unregister_tcp_proto;
1098
1099 err = proto_register(prot: &udplitev6_prot, alloc_slab: 1);
1100 if (err)
1101 goto out_unregister_udp_proto;
1102
1103 err = proto_register(prot: &rawv6_prot, alloc_slab: 1);
1104 if (err)
1105 goto out_unregister_udplite_proto;
1106
1107 err = proto_register(prot: &pingv6_prot, alloc_slab: 1);
1108 if (err)
1109 goto out_unregister_raw_proto;
1110
1111 /* We MUST register RAW sockets before we create the ICMP6,
1112 * IGMP6, or NDISC control sockets.
1113 */
1114 err = rawv6_init();
1115 if (err)
1116 goto out_unregister_ping_proto;
1117
1118 /* Register the family here so that the init calls below will
1119 * be able to create sockets. (?? is this dangerous ??)
1120 */
1121 err = sock_register(fam: &inet6_family_ops);
1122 if (err)
1123 goto out_sock_register_fail;
1124
1125 /*
1126 * ipngwg API draft makes clear that the correct semantics
1127 * for TCP and UDP is to consider one TCP and UDP instance
1128 * in a host available by both INET and INET6 APIs and
1129 * able to communicate via both network protocols.
1130 */
1131
1132 err = register_pernet_subsys(&inet6_net_ops);
1133 if (err)
1134 goto register_pernet_fail;
1135 err = ip6_mr_init();
1136 if (err)
1137 goto ipmr_fail;
1138 err = icmpv6_init();
1139 if (err)
1140 goto icmp_fail;
1141 err = ndisc_init();
1142 if (err)
1143 goto ndisc_fail;
1144 err = igmp6_init();
1145 if (err)
1146 goto igmp_fail;
1147
1148 err = ipv6_netfilter_init();
1149 if (err)
1150 goto netfilter_fail;
1151 /* Create /proc/foo6 entries. */
1152#ifdef CONFIG_PROC_FS
1153 err = -ENOMEM;
1154 if (raw6_proc_init())
1155 goto proc_raw6_fail;
1156 if (udplite6_proc_init())
1157 goto proc_udplite6_fail;
1158 if (ipv6_misc_proc_init())
1159 goto proc_misc6_fail;
1160 if (if6_proc_init())
1161 goto proc_if6_fail;
1162#endif
1163 err = ip6_route_init();
1164 if (err)
1165 goto ip6_route_fail;
1166 err = ndisc_late_init();
1167 if (err)
1168 goto ndisc_late_fail;
1169 err = ip6_flowlabel_init();
1170 if (err)
1171 goto ip6_flowlabel_fail;
1172 err = ipv6_anycast_init();
1173 if (err)
1174 goto ipv6_anycast_fail;
1175 err = addrconf_init();
1176 if (err)
1177 goto addrconf_fail;
1178
1179 /* Init v6 extension headers. */
1180 err = ipv6_exthdrs_init();
1181 if (err)
1182 goto ipv6_exthdrs_fail;
1183
1184 err = ipv6_frag_init();
1185 if (err)
1186 goto ipv6_frag_fail;
1187
1188 /* Init v6 transport protocols. */
1189 err = udpv6_init();
1190 if (err)
1191 goto udpv6_fail;
1192
1193 err = udplitev6_init();
1194 if (err)
1195 goto udplitev6_fail;
1196
1197 err = udpv6_offload_init();
1198 if (err)
1199 goto udpv6_offload_fail;
1200
1201 err = tcpv6_init();
1202 if (err)
1203 goto tcpv6_fail;
1204
1205 err = ipv6_packet_init();
1206 if (err)
1207 goto ipv6_packet_fail;
1208
1209 err = pingv6_init();
1210 if (err)
1211 goto pingv6_fail;
1212
1213 err = calipso_init();
1214 if (err)
1215 goto calipso_fail;
1216
1217 err = seg6_init();
1218 if (err)
1219 goto seg6_fail;
1220
1221 err = rpl_init();
1222 if (err)
1223 goto rpl_fail;
1224
1225 err = ioam6_init();
1226 if (err)
1227 goto ioam6_fail;
1228
1229 err = igmp6_late_init();
1230 if (err)
1231 goto igmp6_late_err;
1232
1233#ifdef CONFIG_SYSCTL
1234 err = ipv6_sysctl_register();
1235 if (err)
1236 goto sysctl_fail;
1237#endif
1238
1239 /* ensure that ipv6 stubs are visible only after ipv6 is ready */
1240 wmb();
1241 ipv6_stub = &ipv6_stub_impl;
1242 ipv6_bpf_stub = &ipv6_bpf_stub_impl;
1243out:
1244 return err;
1245
1246#ifdef CONFIG_SYSCTL
1247sysctl_fail:
1248 igmp6_late_cleanup();
1249#endif
1250igmp6_late_err:
1251 ioam6_exit();
1252ioam6_fail:
1253 rpl_exit();
1254rpl_fail:
1255 seg6_exit();
1256seg6_fail:
1257 calipso_exit();
1258calipso_fail:
1259 pingv6_exit();
1260pingv6_fail:
1261 ipv6_packet_cleanup();
1262ipv6_packet_fail:
1263 tcpv6_exit();
1264tcpv6_fail:
1265 udpv6_offload_exit();
1266udpv6_offload_fail:
1267 udplitev6_exit();
1268udplitev6_fail:
1269 udpv6_exit();
1270udpv6_fail:
1271 ipv6_frag_exit();
1272ipv6_frag_fail:
1273 ipv6_exthdrs_exit();
1274ipv6_exthdrs_fail:
1275 addrconf_cleanup();
1276addrconf_fail:
1277 ipv6_anycast_cleanup();
1278ipv6_anycast_fail:
1279 ip6_flowlabel_cleanup();
1280ip6_flowlabel_fail:
1281 ndisc_late_cleanup();
1282ndisc_late_fail:
1283 ip6_route_cleanup();
1284ip6_route_fail:
1285#ifdef CONFIG_PROC_FS
1286 if6_proc_exit();
1287proc_if6_fail:
1288 ipv6_misc_proc_exit();
1289proc_misc6_fail:
1290 udplite6_proc_exit();
1291proc_udplite6_fail:
1292 raw6_proc_exit();
1293proc_raw6_fail:
1294#endif
1295 ipv6_netfilter_fini();
1296netfilter_fail:
1297 igmp6_cleanup();
1298igmp_fail:
1299 ndisc_cleanup();
1300ndisc_fail:
1301 icmpv6_cleanup();
1302icmp_fail:
1303 ip6_mr_cleanup();
1304ipmr_fail:
1305 unregister_pernet_subsys(&inet6_net_ops);
1306register_pernet_fail:
1307 sock_unregister(PF_INET6);
1308 rtnl_unregister_all(PF_INET6);
1309out_sock_register_fail:
1310 rawv6_exit();
1311out_unregister_ping_proto:
1312 proto_unregister(prot: &pingv6_prot);
1313out_unregister_raw_proto:
1314 proto_unregister(prot: &rawv6_prot);
1315out_unregister_udplite_proto:
1316 proto_unregister(prot: &udplitev6_prot);
1317out_unregister_udp_proto:
1318 proto_unregister(prot: &udpv6_prot);
1319out_unregister_tcp_proto:
1320 proto_unregister(prot: &tcpv6_prot);
1321 goto out;
1322}
1323module_init(inet6_init);
1324
1325MODULE_ALIAS_NETPROTO(PF_INET6);
1326

source code of linux/net/ipv6/af_inet6.c