s390/mm: fix typo in comment
[linux-2.6-microblaze.git] / net / ipv6 / af_inet6.c
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
66 #include <linux/uaccess.h>
67 #include <linux/mroute6.h>
68
69 #include "ip6_offload.h"
70
71 MODULE_AUTHOR("Cast of dozens");
72 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
73 MODULE_LICENSE("GPL");
74
75 /* The inetsw6 table contains everything that inet6_create needs to
76  * build a new socket.
77  */
78 static struct list_head inetsw6[SOCK_MAX];
79 static DEFINE_SPINLOCK(inetsw6_lock);
80
81 struct ipv6_params ipv6_defaults = {
82         .disable_ipv6 = 0,
83         .autoconf = 1,
84 };
85
86 static int disable_ipv6_mod;
87
88 module_param_named(disable, disable_ipv6_mod, int, 0444);
89 MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
90
91 module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
92 MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
93
94 module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
95 MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");
96
97 bool ipv6_mod_enabled(void)
98 {
99         return disable_ipv6_mod == 0;
100 }
101 EXPORT_SYMBOL_GPL(ipv6_mod_enabled);
102
103 static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
104 {
105         const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
106
107         return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
108 }
109
110 static int inet6_create(struct net *net, struct socket *sock, int protocol,
111                         int kern)
112 {
113         struct inet_sock *inet;
114         struct ipv6_pinfo *np;
115         struct sock *sk;
116         struct inet_protosw *answer;
117         struct proto *answer_prot;
118         unsigned char answer_flags;
119         int try_loading_module = 0;
120         int err;
121
122         if (protocol < 0 || protocol >= IPPROTO_MAX)
123                 return -EINVAL;
124
125         /* Look for the requested type/protocol pair. */
126 lookup_protocol:
127         err = -ESOCKTNOSUPPORT;
128         rcu_read_lock();
129         list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {
130
131                 err = 0;
132                 /* Check the non-wild match. */
133                 if (protocol == answer->protocol) {
134                         if (protocol != IPPROTO_IP)
135                                 break;
136                 } else {
137                         /* Check for the two wild cases. */
138                         if (IPPROTO_IP == protocol) {
139                                 protocol = answer->protocol;
140                                 break;
141                         }
142                         if (IPPROTO_IP == answer->protocol)
143                                 break;
144                 }
145                 err = -EPROTONOSUPPORT;
146         }
147
148         if (err) {
149                 if (try_loading_module < 2) {
150                         rcu_read_unlock();
151                         /*
152                          * Be more specific, e.g. net-pf-10-proto-132-type-1
153                          * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
154                          */
155                         if (++try_loading_module == 1)
156                                 request_module("net-pf-%d-proto-%d-type-%d",
157                                                 PF_INET6, protocol, sock->type);
158                         /*
159                          * Fall back to generic, e.g. net-pf-10-proto-132
160                          * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
161                          */
162                         else
163                                 request_module("net-pf-%d-proto-%d",
164                                                 PF_INET6, protocol);
165                         goto lookup_protocol;
166                 } else
167                         goto out_rcu_unlock;
168         }
169
170         err = -EPERM;
171         if (sock->type == SOCK_RAW && !kern &&
172             !ns_capable(net->user_ns, CAP_NET_RAW))
173                 goto out_rcu_unlock;
174
175         sock->ops = answer->ops;
176         answer_prot = answer->prot;
177         answer_flags = answer->flags;
178         rcu_read_unlock();
179
180         WARN_ON(!answer_prot->slab);
181
182         err = -ENOBUFS;
183         sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot, kern);
184         if (!sk)
185                 goto out;
186
187         sock_init_data(sock, sk);
188
189         err = 0;
190         if (INET_PROTOSW_REUSE & answer_flags)
191                 sk->sk_reuse = SK_CAN_REUSE;
192
193         inet = inet_sk(sk);
194         inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
195
196         if (SOCK_RAW == sock->type) {
197                 inet->inet_num = protocol;
198                 if (IPPROTO_RAW == protocol)
199                         inet->hdrincl = 1;
200         }
201
202         sk->sk_destruct         = inet_sock_destruct;
203         sk->sk_family           = PF_INET6;
204         sk->sk_protocol         = protocol;
205
206         sk->sk_backlog_rcv      = answer->prot->backlog_rcv;
207
208         inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
209         np->hop_limit   = -1;
210         np->mcast_hops  = IPV6_DEFAULT_MCASTHOPS;
211         np->mc_loop     = 1;
212         np->mc_all      = 1;
213         np->pmtudisc    = IPV6_PMTUDISC_WANT;
214         np->repflow     = net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ESTABLISHED;
215         sk->sk_ipv6only = net->ipv6.sysctl.bindv6only;
216
217         /* Init the ipv4 part of the socket since we can have sockets
218          * using v6 API for ipv4.
219          */
220         inet->uc_ttl    = -1;
221
222         inet->mc_loop   = 1;
223         inet->mc_ttl    = 1;
224         inet->mc_index  = 0;
225         inet->mc_list   = NULL;
226         inet->rcv_tos   = 0;
227
228         if (net->ipv4.sysctl_ip_no_pmtu_disc)
229                 inet->pmtudisc = IP_PMTUDISC_DONT;
230         else
231                 inet->pmtudisc = IP_PMTUDISC_WANT;
232         /*
233          * Increment only the relevant sk_prot->socks debug field, this changes
234          * the previous behaviour of incrementing both the equivalent to
235          * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
236          *
237          * This allows better debug granularity as we'll know exactly how many
238          * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
239          * transport protocol socks. -acme
240          */
241         sk_refcnt_debug_inc(sk);
242
243         if (inet->inet_num) {
244                 /* It assumes that any protocol which allows
245                  * the user to assign a number at socket
246                  * creation time automatically shares.
247                  */
248                 inet->inet_sport = htons(inet->inet_num);
249                 err = sk->sk_prot->hash(sk);
250                 if (err) {
251                         sk_common_release(sk);
252                         goto out;
253                 }
254         }
255         if (sk->sk_prot->init) {
256                 err = sk->sk_prot->init(sk);
257                 if (err) {
258                         sk_common_release(sk);
259                         goto out;
260                 }
261         }
262
263         if (!kern) {
264                 err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
265                 if (err) {
266                         sk_common_release(sk);
267                         goto out;
268                 }
269         }
270 out:
271         return err;
272 out_rcu_unlock:
273         rcu_read_unlock();
274         goto out;
275 }
276
277 static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
278                         u32 flags)
279 {
280         struct sockaddr_in6 *addr = (struct sockaddr_in6 *)uaddr;
281         struct inet_sock *inet = inet_sk(sk);
282         struct ipv6_pinfo *np = inet6_sk(sk);
283         struct net *net = sock_net(sk);
284         __be32 v4addr = 0;
285         unsigned short snum;
286         bool saved_ipv6only;
287         int addr_type = 0;
288         int err = 0;
289
290         if (addr->sin6_family != AF_INET6)
291                 return -EAFNOSUPPORT;
292
293         addr_type = ipv6_addr_type(&addr->sin6_addr);
294         if ((addr_type & IPV6_ADDR_MULTICAST) && sk->sk_type == SOCK_STREAM)
295                 return -EINVAL;
296
297         snum = ntohs(addr->sin6_port);
298         if (snum && inet_port_requires_bind_service(net, snum) &&
299             !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
300                 return -EACCES;
301
302         if (flags & BIND_WITH_LOCK)
303                 lock_sock(sk);
304
305         /* Check these errors (active socket, double bind). */
306         if (sk->sk_state != TCP_CLOSE || inet->inet_num) {
307                 err = -EINVAL;
308                 goto out;
309         }
310
311         /* Check if the address belongs to the host. */
312         if (addr_type == IPV6_ADDR_MAPPED) {
313                 struct net_device *dev = NULL;
314                 int chk_addr_ret;
315
316                 /* Binding to v4-mapped address on a v6-only socket
317                  * makes no sense
318                  */
319                 if (sk->sk_ipv6only) {
320                         err = -EINVAL;
321                         goto out;
322                 }
323
324                 rcu_read_lock();
325                 if (sk->sk_bound_dev_if) {
326                         dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
327                         if (!dev) {
328                                 err = -ENODEV;
329                                 goto out_unlock;
330                         }
331                 }
332
333                 /* Reproduce AF_INET checks to make the bindings consistent */
334                 v4addr = addr->sin6_addr.s6_addr32[3];
335                 chk_addr_ret = inet_addr_type_dev_table(net, dev, v4addr);
336                 rcu_read_unlock();
337
338                 if (!inet_can_nonlocal_bind(net, inet) &&
339                     v4addr != htonl(INADDR_ANY) &&
340                     chk_addr_ret != RTN_LOCAL &&
341                     chk_addr_ret != RTN_MULTICAST &&
342                     chk_addr_ret != RTN_BROADCAST) {
343                         err = -EADDRNOTAVAIL;
344                         goto out;
345                 }
346         } else {
347                 if (addr_type != IPV6_ADDR_ANY) {
348                         struct net_device *dev = NULL;
349
350                         rcu_read_lock();
351                         if (__ipv6_addr_needs_scope_id(addr_type)) {
352                                 if (addr_len >= sizeof(struct sockaddr_in6) &&
353                                     addr->sin6_scope_id) {
354                                         /* Override any existing binding, if another one
355                                          * is supplied by user.
356                                          */
357                                         sk->sk_bound_dev_if = addr->sin6_scope_id;
358                                 }
359
360                                 /* Binding to link-local address requires an interface */
361                                 if (!sk->sk_bound_dev_if) {
362                                         err = -EINVAL;
363                                         goto out_unlock;
364                                 }
365                         }
366
367                         if (sk->sk_bound_dev_if) {
368                                 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
369                                 if (!dev) {
370                                         err = -ENODEV;
371                                         goto out_unlock;
372                                 }
373                         }
374
375                         /* ipv4 addr of the socket is invalid.  Only the
376                          * unspecified and mapped address have a v4 equivalent.
377                          */
378                         v4addr = LOOPBACK4_IPV6;
379                         if (!(addr_type & IPV6_ADDR_MULTICAST)) {
380                                 if (!ipv6_can_nonlocal_bind(net, inet) &&
381                                     !ipv6_chk_addr(net, &addr->sin6_addr,
382                                                    dev, 0)) {
383                                         err = -EADDRNOTAVAIL;
384                                         goto out_unlock;
385                                 }
386                         }
387                         rcu_read_unlock();
388                 }
389         }
390
391         inet->inet_rcv_saddr = v4addr;
392         inet->inet_saddr = v4addr;
393
394         sk->sk_v6_rcv_saddr = addr->sin6_addr;
395
396         if (!(addr_type & IPV6_ADDR_MULTICAST))
397                 np->saddr = addr->sin6_addr;
398
399         saved_ipv6only = sk->sk_ipv6only;
400         if (addr_type != IPV6_ADDR_ANY && addr_type != IPV6_ADDR_MAPPED)
401                 sk->sk_ipv6only = 1;
402
403         /* Make sure we are allowed to bind here. */
404         if (snum || !(inet->bind_address_no_port ||
405                       (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
406                 if (sk->sk_prot->get_port(sk, snum)) {
407                         sk->sk_ipv6only = saved_ipv6only;
408                         inet_reset_saddr(sk);
409                         err = -EADDRINUSE;
410                         goto out;
411                 }
412                 if (!(flags & BIND_FROM_BPF)) {
413                         err = BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk);
414                         if (err) {
415                                 sk->sk_ipv6only = saved_ipv6only;
416                                 inet_reset_saddr(sk);
417                                 goto out;
418                         }
419                 }
420         }
421
422         if (addr_type != IPV6_ADDR_ANY)
423                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
424         if (snum)
425                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
426         inet->inet_sport = htons(inet->inet_num);
427         inet->inet_dport = 0;
428         inet->inet_daddr = 0;
429 out:
430         if (flags & BIND_WITH_LOCK)
431                 release_sock(sk);
432         return err;
433 out_unlock:
434         rcu_read_unlock();
435         goto out;
436 }
437
438 /* bind for INET6 API */
439 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
440 {
441         struct sock *sk = sock->sk;
442         int err = 0;
443
444         /* If the socket has its own bind function then use it. */
445         if (sk->sk_prot->bind)
446                 return sk->sk_prot->bind(sk, uaddr, addr_len);
447
448         if (addr_len < SIN6_LEN_RFC2133)
449                 return -EINVAL;
450
451         /* BPF prog is run before any checks are done so that if the prog
452          * changes context in a wrong way it will be caught.
453          */
454         err = BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr);
455         if (err)
456                 return err;
457
458         return __inet6_bind(sk, uaddr, addr_len, BIND_WITH_LOCK);
459 }
460 EXPORT_SYMBOL(inet6_bind);
461
462 int inet6_release(struct socket *sock)
463 {
464         struct sock *sk = sock->sk;
465
466         if (!sk)
467                 return -EINVAL;
468
469         /* Free mc lists */
470         ipv6_sock_mc_close(sk);
471
472         /* Free ac lists */
473         ipv6_sock_ac_close(sk);
474
475         return inet_release(sock);
476 }
477 EXPORT_SYMBOL(inet6_release);
478
479 void inet6_destroy_sock(struct sock *sk)
480 {
481         struct ipv6_pinfo *np = inet6_sk(sk);
482         struct sk_buff *skb;
483         struct ipv6_txoptions *opt;
484
485         /* Release rx options */
486
487         skb = xchg(&np->pktoptions, NULL);
488         kfree_skb(skb);
489
490         skb = xchg(&np->rxpmtu, NULL);
491         kfree_skb(skb);
492
493         /* Free flowlabels */
494         fl6_free_socklist(sk);
495
496         /* Free tx options */
497
498         opt = xchg((__force struct ipv6_txoptions **)&np->opt, NULL);
499         if (opt) {
500                 atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
501                 txopt_put(opt);
502         }
503 }
504 EXPORT_SYMBOL_GPL(inet6_destroy_sock);
505
506 /*
507  *      This does both peername and sockname.
508  */
509 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
510                   int peer)
511 {
512         struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr;
513         struct sock *sk = sock->sk;
514         struct inet_sock *inet = inet_sk(sk);
515         struct ipv6_pinfo *np = inet6_sk(sk);
516
517         sin->sin6_family = AF_INET6;
518         sin->sin6_flowinfo = 0;
519         sin->sin6_scope_id = 0;
520         if (peer) {
521                 if (!inet->inet_dport)
522                         return -ENOTCONN;
523                 if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
524                     peer == 1)
525                         return -ENOTCONN;
526                 sin->sin6_port = inet->inet_dport;
527                 sin->sin6_addr = sk->sk_v6_daddr;
528                 if (np->sndflow)
529                         sin->sin6_flowinfo = np->flow_label;
530         } else {
531                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
532                         sin->sin6_addr = np->saddr;
533                 else
534                         sin->sin6_addr = sk->sk_v6_rcv_saddr;
535                 sin->sin6_port = inet->inet_sport;
536         }
537         if (cgroup_bpf_enabled)
538                 BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin,
539                                             peer ? BPF_CGROUP_INET6_GETPEERNAME :
540                                                    BPF_CGROUP_INET6_GETSOCKNAME,
541                                             NULL);
542         sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr,
543                                                  sk->sk_bound_dev_if);
544         return sizeof(*sin);
545 }
546 EXPORT_SYMBOL(inet6_getname);
547
548 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
549 {
550         void __user *argp = (void __user *)arg;
551         struct sock *sk = sock->sk;
552         struct net *net = sock_net(sk);
553
554         switch (cmd) {
555         case SIOCADDRT:
556         case SIOCDELRT: {
557                 struct in6_rtmsg rtmsg;
558
559                 if (copy_from_user(&rtmsg, argp, sizeof(rtmsg)))
560                         return -EFAULT;
561                 return ipv6_route_ioctl(net, cmd, &rtmsg);
562         }
563         case SIOCSIFADDR:
564                 return addrconf_add_ifaddr(net, argp);
565         case SIOCDIFADDR:
566                 return addrconf_del_ifaddr(net, argp);
567         case SIOCSIFDSTADDR:
568                 return addrconf_set_dstaddr(net, argp);
569         default:
570                 if (!sk->sk_prot->ioctl)
571                         return -ENOIOCTLCMD;
572                 return sk->sk_prot->ioctl(sk, cmd, arg);
573         }
574         /*NOTREACHED*/
575         return 0;
576 }
577 EXPORT_SYMBOL(inet6_ioctl);
578
579 #ifdef CONFIG_COMPAT
580 struct compat_in6_rtmsg {
581         struct in6_addr         rtmsg_dst;
582         struct in6_addr         rtmsg_src;
583         struct in6_addr         rtmsg_gateway;
584         u32                     rtmsg_type;
585         u16                     rtmsg_dst_len;
586         u16                     rtmsg_src_len;
587         u32                     rtmsg_metric;
588         u32                     rtmsg_info;
589         u32                     rtmsg_flags;
590         s32                     rtmsg_ifindex;
591 };
592
593 static int inet6_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
594                 struct compat_in6_rtmsg __user *ur)
595 {
596         struct in6_rtmsg rt;
597
598         if (copy_from_user(&rt.rtmsg_dst, &ur->rtmsg_dst,
599                         3 * sizeof(struct in6_addr)) ||
600             get_user(rt.rtmsg_type, &ur->rtmsg_type) ||
601             get_user(rt.rtmsg_dst_len, &ur->rtmsg_dst_len) ||
602             get_user(rt.rtmsg_src_len, &ur->rtmsg_src_len) ||
603             get_user(rt.rtmsg_metric, &ur->rtmsg_metric) ||
604             get_user(rt.rtmsg_info, &ur->rtmsg_info) ||
605             get_user(rt.rtmsg_flags, &ur->rtmsg_flags) ||
606             get_user(rt.rtmsg_ifindex, &ur->rtmsg_ifindex))
607                 return -EFAULT;
608
609
610         return ipv6_route_ioctl(sock_net(sk), cmd, &rt);
611 }
612
613 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
614 {
615         void __user *argp = compat_ptr(arg);
616         struct sock *sk = sock->sk;
617
618         switch (cmd) {
619         case SIOCADDRT:
620         case SIOCDELRT:
621                 return inet6_compat_routing_ioctl(sk, cmd, argp);
622         default:
623                 return -ENOIOCTLCMD;
624         }
625 }
626 EXPORT_SYMBOL_GPL(inet6_compat_ioctl);
627 #endif /* CONFIG_COMPAT */
628
629 INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
630                                             size_t));
631 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
632 {
633         struct sock *sk = sock->sk;
634
635         if (unlikely(inet_send_prepare(sk)))
636                 return -EAGAIN;
637
638         return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
639                                sk, msg, size);
640 }
641
642 INDIRECT_CALLABLE_DECLARE(int udpv6_recvmsg(struct sock *, struct msghdr *,
643                                             size_t, int, int, int *));
644 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
645                   int flags)
646 {
647         struct sock *sk = sock->sk;
648         int addr_len = 0;
649         int err;
650
651         if (likely(!(flags & MSG_ERRQUEUE)))
652                 sock_rps_record_flow(sk);
653
654         err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
655                               sk, msg, size, flags & MSG_DONTWAIT,
656                               flags & ~MSG_DONTWAIT, &addr_len);
657         if (err >= 0)
658                 msg->msg_namelen = addr_len;
659         return err;
660 }
661
662 const struct proto_ops inet6_stream_ops = {
663         .family            = PF_INET6,
664         .owner             = THIS_MODULE,
665         .release           = inet6_release,
666         .bind              = inet6_bind,
667         .connect           = inet_stream_connect,       /* ok           */
668         .socketpair        = sock_no_socketpair,        /* a do nothing */
669         .accept            = inet_accept,               /* ok           */
670         .getname           = inet6_getname,
671         .poll              = tcp_poll,                  /* ok           */
672         .ioctl             = inet6_ioctl,               /* must change  */
673         .gettstamp         = sock_gettstamp,
674         .listen            = inet_listen,               /* ok           */
675         .shutdown          = inet_shutdown,             /* ok           */
676         .setsockopt        = sock_common_setsockopt,    /* ok           */
677         .getsockopt        = sock_common_getsockopt,    /* ok           */
678         .sendmsg           = inet6_sendmsg,             /* retpoline's sake */
679         .recvmsg           = inet6_recvmsg,             /* retpoline's sake */
680 #ifdef CONFIG_MMU
681         .mmap              = tcp_mmap,
682 #endif
683         .sendpage          = inet_sendpage,
684         .sendmsg_locked    = tcp_sendmsg_locked,
685         .sendpage_locked   = tcp_sendpage_locked,
686         .splice_read       = tcp_splice_read,
687         .read_sock         = tcp_read_sock,
688         .peek_len          = tcp_peek_len,
689 #ifdef CONFIG_COMPAT
690         .compat_ioctl      = inet6_compat_ioctl,
691         .compat_setsockopt = compat_sock_common_setsockopt,
692         .compat_getsockopt = compat_sock_common_getsockopt,
693 #endif
694         .set_rcvlowat      = tcp_set_rcvlowat,
695 };
696
697 const struct proto_ops inet6_dgram_ops = {
698         .family            = PF_INET6,
699         .owner             = THIS_MODULE,
700         .release           = inet6_release,
701         .bind              = inet6_bind,
702         .connect           = inet_dgram_connect,        /* ok           */
703         .socketpair        = sock_no_socketpair,        /* a do nothing */
704         .accept            = sock_no_accept,            /* a do nothing */
705         .getname           = inet6_getname,
706         .poll              = udp_poll,                  /* ok           */
707         .ioctl             = inet6_ioctl,               /* must change  */
708         .gettstamp         = sock_gettstamp,
709         .listen            = sock_no_listen,            /* ok           */
710         .shutdown          = inet_shutdown,             /* ok           */
711         .setsockopt        = sock_common_setsockopt,    /* ok           */
712         .getsockopt        = sock_common_getsockopt,    /* ok           */
713         .sendmsg           = inet6_sendmsg,             /* retpoline's sake */
714         .recvmsg           = inet6_recvmsg,             /* retpoline's sake */
715         .mmap              = sock_no_mmap,
716         .sendpage          = sock_no_sendpage,
717         .set_peek_off      = sk_set_peek_off,
718 #ifdef CONFIG_COMPAT
719         .compat_ioctl      = inet6_compat_ioctl,
720         .compat_setsockopt = compat_sock_common_setsockopt,
721         .compat_getsockopt = compat_sock_common_getsockopt,
722 #endif
723 };
724
725 static const struct net_proto_family inet6_family_ops = {
726         .family = PF_INET6,
727         .create = inet6_create,
728         .owner  = THIS_MODULE,
729 };
730
731 int inet6_register_protosw(struct inet_protosw *p)
732 {
733         struct list_head *lh;
734         struct inet_protosw *answer;
735         struct list_head *last_perm;
736         int protocol = p->protocol;
737         int ret;
738
739         spin_lock_bh(&inetsw6_lock);
740
741         ret = -EINVAL;
742         if (p->type >= SOCK_MAX)
743                 goto out_illegal;
744
745         /* If we are trying to override a permanent protocol, bail. */
746         answer = NULL;
747         ret = -EPERM;
748         last_perm = &inetsw6[p->type];
749         list_for_each(lh, &inetsw6[p->type]) {
750                 answer = list_entry(lh, struct inet_protosw, list);
751
752                 /* Check only the non-wild match. */
753                 if (INET_PROTOSW_PERMANENT & answer->flags) {
754                         if (protocol == answer->protocol)
755                                 break;
756                         last_perm = lh;
757                 }
758
759                 answer = NULL;
760         }
761         if (answer)
762                 goto out_permanent;
763
764         /* Add the new entry after the last permanent entry if any, so that
765          * the new entry does not override a permanent entry when matched with
766          * a wild-card protocol. But it is allowed to override any existing
767          * non-permanent entry.  This means that when we remove this entry, the
768          * system automatically returns to the old behavior.
769          */
770         list_add_rcu(&p->list, last_perm);
771         ret = 0;
772 out:
773         spin_unlock_bh(&inetsw6_lock);
774         return ret;
775
776 out_permanent:
777         pr_err("Attempt to override permanent protocol %d\n", protocol);
778         goto out;
779
780 out_illegal:
781         pr_err("Ignoring attempt to register invalid socket type %d\n",
782                p->type);
783         goto out;
784 }
785 EXPORT_SYMBOL(inet6_register_protosw);
786
787 void
788 inet6_unregister_protosw(struct inet_protosw *p)
789 {
790         if (INET_PROTOSW_PERMANENT & p->flags) {
791                 pr_err("Attempt to unregister permanent protocol %d\n",
792                        p->protocol);
793         } else {
794                 spin_lock_bh(&inetsw6_lock);
795                 list_del_rcu(&p->list);
796                 spin_unlock_bh(&inetsw6_lock);
797
798                 synchronize_net();
799         }
800 }
801 EXPORT_SYMBOL(inet6_unregister_protosw);
802
803 int inet6_sk_rebuild_header(struct sock *sk)
804 {
805         struct ipv6_pinfo *np = inet6_sk(sk);
806         struct dst_entry *dst;
807
808         dst = __sk_dst_check(sk, np->dst_cookie);
809
810         if (!dst) {
811                 struct inet_sock *inet = inet_sk(sk);
812                 struct in6_addr *final_p, final;
813                 struct flowi6 fl6;
814
815                 memset(&fl6, 0, sizeof(fl6));
816                 fl6.flowi6_proto = sk->sk_protocol;
817                 fl6.daddr = sk->sk_v6_daddr;
818                 fl6.saddr = np->saddr;
819                 fl6.flowlabel = np->flow_label;
820                 fl6.flowi6_oif = sk->sk_bound_dev_if;
821                 fl6.flowi6_mark = sk->sk_mark;
822                 fl6.fl6_dport = inet->inet_dport;
823                 fl6.fl6_sport = inet->inet_sport;
824                 fl6.flowi6_uid = sk->sk_uid;
825                 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
826
827                 rcu_read_lock();
828                 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt),
829                                          &final);
830                 rcu_read_unlock();
831
832                 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
833                 if (IS_ERR(dst)) {
834                         sk->sk_route_caps = 0;
835                         sk->sk_err_soft = -PTR_ERR(dst);
836                         return PTR_ERR(dst);
837                 }
838
839                 ip6_dst_store(sk, dst, NULL, NULL);
840         }
841
842         return 0;
843 }
844 EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);
845
846 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
847                        const struct inet6_skb_parm *opt)
848 {
849         const struct ipv6_pinfo *np = inet6_sk(sk);
850
851         if (np->rxopt.all) {
852                 if (((opt->flags & IP6SKB_HOPBYHOP) &&
853                      (np->rxopt.bits.hopopts || np->rxopt.bits.ohopopts)) ||
854                     (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
855                      np->rxopt.bits.rxflow) ||
856                     (opt->srcrt && (np->rxopt.bits.srcrt ||
857                      np->rxopt.bits.osrcrt)) ||
858                     ((opt->dst1 || opt->dst0) &&
859                      (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
860                         return true;
861         }
862         return false;
863 }
864 EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
865
866 static struct packet_type ipv6_packet_type __read_mostly = {
867         .type = cpu_to_be16(ETH_P_IPV6),
868         .func = ipv6_rcv,
869         .list_func = ipv6_list_rcv,
870 };
871
872 static int __init ipv6_packet_init(void)
873 {
874         dev_add_pack(&ipv6_packet_type);
875         return 0;
876 }
877
878 static void ipv6_packet_cleanup(void)
879 {
880         dev_remove_pack(&ipv6_packet_type);
881 }
882
883 static int __net_init ipv6_init_mibs(struct net *net)
884 {
885         int i;
886
887         net->mib.udp_stats_in6 = alloc_percpu(struct udp_mib);
888         if (!net->mib.udp_stats_in6)
889                 return -ENOMEM;
890         net->mib.udplite_stats_in6 = alloc_percpu(struct udp_mib);
891         if (!net->mib.udplite_stats_in6)
892                 goto err_udplite_mib;
893         net->mib.ipv6_statistics = alloc_percpu(struct ipstats_mib);
894         if (!net->mib.ipv6_statistics)
895                 goto err_ip_mib;
896
897         for_each_possible_cpu(i) {
898                 struct ipstats_mib *af_inet6_stats;
899                 af_inet6_stats = per_cpu_ptr(net->mib.ipv6_statistics, i);
900                 u64_stats_init(&af_inet6_stats->syncp);
901         }
902
903
904         net->mib.icmpv6_statistics = alloc_percpu(struct icmpv6_mib);
905         if (!net->mib.icmpv6_statistics)
906                 goto err_icmp_mib;
907         net->mib.icmpv6msg_statistics = kzalloc(sizeof(struct icmpv6msg_mib),
908                                                 GFP_KERNEL);
909         if (!net->mib.icmpv6msg_statistics)
910                 goto err_icmpmsg_mib;
911         return 0;
912
913 err_icmpmsg_mib:
914         free_percpu(net->mib.icmpv6_statistics);
915 err_icmp_mib:
916         free_percpu(net->mib.ipv6_statistics);
917 err_ip_mib:
918         free_percpu(net->mib.udplite_stats_in6);
919 err_udplite_mib:
920         free_percpu(net->mib.udp_stats_in6);
921         return -ENOMEM;
922 }
923
924 static void ipv6_cleanup_mibs(struct net *net)
925 {
926         free_percpu(net->mib.udp_stats_in6);
927         free_percpu(net->mib.udplite_stats_in6);
928         free_percpu(net->mib.ipv6_statistics);
929         free_percpu(net->mib.icmpv6_statistics);
930         kfree(net->mib.icmpv6msg_statistics);
931 }
932
933 static int __net_init inet6_net_init(struct net *net)
934 {
935         int err = 0;
936
937         net->ipv6.sysctl.bindv6only = 0;
938         net->ipv6.sysctl.icmpv6_time = 1*HZ;
939         net->ipv6.sysctl.icmpv6_echo_ignore_all = 0;
940         net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0;
941         net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0;
942
943         /* By default, rate limit error messages.
944          * Except for pmtu discovery, it would break it.
945          * proc_do_large_bitmap needs pointer to the bitmap.
946          */
947         bitmap_set(net->ipv6.sysctl.icmpv6_ratemask, 0, ICMPV6_ERRMSG_MAX + 1);
948         bitmap_clear(net->ipv6.sysctl.icmpv6_ratemask, ICMPV6_PKT_TOOBIG, 1);
949         net->ipv6.sysctl.icmpv6_ratemask_ptr = net->ipv6.sysctl.icmpv6_ratemask;
950
951         net->ipv6.sysctl.flowlabel_consistency = 1;
952         net->ipv6.sysctl.auto_flowlabels = IP6_DEFAULT_AUTO_FLOW_LABELS;
953         net->ipv6.sysctl.idgen_retries = 3;
954         net->ipv6.sysctl.idgen_delay = 1 * HZ;
955         net->ipv6.sysctl.flowlabel_state_ranges = 0;
956         net->ipv6.sysctl.max_dst_opts_cnt = IP6_DEFAULT_MAX_DST_OPTS_CNT;
957         net->ipv6.sysctl.max_hbh_opts_cnt = IP6_DEFAULT_MAX_HBH_OPTS_CNT;
958         net->ipv6.sysctl.max_dst_opts_len = IP6_DEFAULT_MAX_DST_OPTS_LEN;
959         net->ipv6.sysctl.max_hbh_opts_len = IP6_DEFAULT_MAX_HBH_OPTS_LEN;
960         atomic_set(&net->ipv6.fib6_sernum, 1);
961
962         err = ipv6_init_mibs(net);
963         if (err)
964                 return err;
965 #ifdef CONFIG_PROC_FS
966         err = udp6_proc_init(net);
967         if (err)
968                 goto out;
969         err = tcp6_proc_init(net);
970         if (err)
971                 goto proc_tcp6_fail;
972         err = ac6_proc_init(net);
973         if (err)
974                 goto proc_ac6_fail;
975 #endif
976         return err;
977
978 #ifdef CONFIG_PROC_FS
979 proc_ac6_fail:
980         tcp6_proc_exit(net);
981 proc_tcp6_fail:
982         udp6_proc_exit(net);
983 out:
984         ipv6_cleanup_mibs(net);
985         return err;
986 #endif
987 }
988
989 static void __net_exit inet6_net_exit(struct net *net)
990 {
991 #ifdef CONFIG_PROC_FS
992         udp6_proc_exit(net);
993         tcp6_proc_exit(net);
994         ac6_proc_exit(net);
995 #endif
996         ipv6_cleanup_mibs(net);
997 }
998
999 static struct pernet_operations inet6_net_ops = {
1000         .init = inet6_net_init,
1001         .exit = inet6_net_exit,
1002 };
1003
1004 static int ipv6_route_input(struct sk_buff *skb)
1005 {
1006         ip6_route_input(skb);
1007         return skb_dst(skb)->error;
1008 }
1009
1010 static const struct ipv6_stub ipv6_stub_impl = {
1011         .ipv6_sock_mc_join = ipv6_sock_mc_join,
1012         .ipv6_sock_mc_drop = ipv6_sock_mc_drop,
1013         .ipv6_dst_lookup_flow = ip6_dst_lookup_flow,
1014         .ipv6_route_input  = ipv6_route_input,
1015         .fib6_get_table    = fib6_get_table,
1016         .fib6_table_lookup = fib6_table_lookup,
1017         .fib6_lookup       = fib6_lookup,
1018         .fib6_select_path  = fib6_select_path,
1019         .ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
1020         .fib6_nh_init      = fib6_nh_init,
1021         .fib6_nh_release   = fib6_nh_release,
1022         .fib6_update_sernum = fib6_update_sernum_stub,
1023         .fib6_rt_update    = fib6_rt_update,
1024         .ip6_del_rt        = ip6_del_rt,
1025         .udpv6_encap_enable = udpv6_encap_enable,
1026         .ndisc_send_na = ndisc_send_na,
1027 #if IS_ENABLED(CONFIG_XFRM)
1028         .xfrm6_local_rxpmtu = xfrm6_local_rxpmtu,
1029         .xfrm6_udp_encap_rcv = xfrm6_udp_encap_rcv,
1030         .xfrm6_rcv_encap = xfrm6_rcv_encap,
1031 #endif
1032         .nd_tbl = &nd_tbl,
1033 };
1034
1035 static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
1036         .inet6_bind = __inet6_bind,
1037         .udp6_lib_lookup = __udp6_lib_lookup,
1038 };
1039
1040 static int __init inet6_init(void)
1041 {
1042         struct list_head *r;
1043         int err = 0;
1044
1045         sock_skb_cb_check_size(sizeof(struct inet6_skb_parm));
1046
1047         /* Register the socket-side information for inet6_create.  */
1048         for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
1049                 INIT_LIST_HEAD(r);
1050
1051         if (disable_ipv6_mod) {
1052                 pr_info("Loaded, but administratively disabled, reboot required to enable\n");
1053                 goto out;
1054         }
1055
1056         err = proto_register(&tcpv6_prot, 1);
1057         if (err)
1058                 goto out;
1059
1060         err = proto_register(&udpv6_prot, 1);
1061         if (err)
1062                 goto out_unregister_tcp_proto;
1063
1064         err = proto_register(&udplitev6_prot, 1);
1065         if (err)
1066                 goto out_unregister_udp_proto;
1067
1068         err = proto_register(&rawv6_prot, 1);
1069         if (err)
1070                 goto out_unregister_udplite_proto;
1071
1072         err = proto_register(&pingv6_prot, 1);
1073         if (err)
1074                 goto out_unregister_raw_proto;
1075
1076         /* We MUST register RAW sockets before we create the ICMP6,
1077          * IGMP6, or NDISC control sockets.
1078          */
1079         err = rawv6_init();
1080         if (err)
1081                 goto out_unregister_ping_proto;
1082
1083         /* Register the family here so that the init calls below will
1084          * be able to create sockets. (?? is this dangerous ??)
1085          */
1086         err = sock_register(&inet6_family_ops);
1087         if (err)
1088                 goto out_sock_register_fail;
1089
1090         /*
1091          *      ipngwg API draft makes clear that the correct semantics
1092          *      for TCP and UDP is to consider one TCP and UDP instance
1093          *      in a host available by both INET and INET6 APIs and
1094          *      able to communicate via both network protocols.
1095          */
1096
1097         err = register_pernet_subsys(&inet6_net_ops);
1098         if (err)
1099                 goto register_pernet_fail;
1100         err = ip6_mr_init();
1101         if (err)
1102                 goto ipmr_fail;
1103         err = icmpv6_init();
1104         if (err)
1105                 goto icmp_fail;
1106         err = ndisc_init();
1107         if (err)
1108                 goto ndisc_fail;
1109         err = igmp6_init();
1110         if (err)
1111                 goto igmp_fail;
1112
1113         err = ipv6_netfilter_init();
1114         if (err)
1115                 goto netfilter_fail;
1116         /* Create /proc/foo6 entries. */
1117 #ifdef CONFIG_PROC_FS
1118         err = -ENOMEM;
1119         if (raw6_proc_init())
1120                 goto proc_raw6_fail;
1121         if (udplite6_proc_init())
1122                 goto proc_udplite6_fail;
1123         if (ipv6_misc_proc_init())
1124                 goto proc_misc6_fail;
1125         if (if6_proc_init())
1126                 goto proc_if6_fail;
1127 #endif
1128         err = ip6_route_init();
1129         if (err)
1130                 goto ip6_route_fail;
1131         err = ndisc_late_init();
1132         if (err)
1133                 goto ndisc_late_fail;
1134         err = ip6_flowlabel_init();
1135         if (err)
1136                 goto ip6_flowlabel_fail;
1137         err = ipv6_anycast_init();
1138         if (err)
1139                 goto ipv6_anycast_fail;
1140         err = addrconf_init();
1141         if (err)
1142                 goto addrconf_fail;
1143
1144         /* Init v6 extension headers. */
1145         err = ipv6_exthdrs_init();
1146         if (err)
1147                 goto ipv6_exthdrs_fail;
1148
1149         err = ipv6_frag_init();
1150         if (err)
1151                 goto ipv6_frag_fail;
1152
1153         /* Init v6 transport protocols. */
1154         err = udpv6_init();
1155         if (err)
1156                 goto udpv6_fail;
1157
1158         err = udplitev6_init();
1159         if (err)
1160                 goto udplitev6_fail;
1161
1162         err = udpv6_offload_init();
1163         if (err)
1164                 goto udpv6_offload_fail;
1165
1166         err = tcpv6_init();
1167         if (err)
1168                 goto tcpv6_fail;
1169
1170         err = ipv6_packet_init();
1171         if (err)
1172                 goto ipv6_packet_fail;
1173
1174         err = pingv6_init();
1175         if (err)
1176                 goto pingv6_fail;
1177
1178         err = calipso_init();
1179         if (err)
1180                 goto calipso_fail;
1181
1182         err = seg6_init();
1183         if (err)
1184                 goto seg6_fail;
1185
1186         err = rpl_init();
1187         if (err)
1188                 goto rpl_fail;
1189
1190         err = igmp6_late_init();
1191         if (err)
1192                 goto igmp6_late_err;
1193
1194 #ifdef CONFIG_SYSCTL
1195         err = ipv6_sysctl_register();
1196         if (err)
1197                 goto sysctl_fail;
1198 #endif
1199
1200         /* ensure that ipv6 stubs are visible only after ipv6 is ready */
1201         wmb();
1202         ipv6_stub = &ipv6_stub_impl;
1203         ipv6_bpf_stub = &ipv6_bpf_stub_impl;
1204 out:
1205         return err;
1206
1207 #ifdef CONFIG_SYSCTL
1208 sysctl_fail:
1209         igmp6_late_cleanup();
1210 #endif
1211 igmp6_late_err:
1212         rpl_exit();
1213 rpl_fail:
1214         seg6_exit();
1215 seg6_fail:
1216         calipso_exit();
1217 calipso_fail:
1218         pingv6_exit();
1219 pingv6_fail:
1220         ipv6_packet_cleanup();
1221 ipv6_packet_fail:
1222         tcpv6_exit();
1223 tcpv6_fail:
1224         udpv6_offload_exit();
1225 udpv6_offload_fail:
1226         udplitev6_exit();
1227 udplitev6_fail:
1228         udpv6_exit();
1229 udpv6_fail:
1230         ipv6_frag_exit();
1231 ipv6_frag_fail:
1232         ipv6_exthdrs_exit();
1233 ipv6_exthdrs_fail:
1234         addrconf_cleanup();
1235 addrconf_fail:
1236         ipv6_anycast_cleanup();
1237 ipv6_anycast_fail:
1238         ip6_flowlabel_cleanup();
1239 ip6_flowlabel_fail:
1240         ndisc_late_cleanup();
1241 ndisc_late_fail:
1242         ip6_route_cleanup();
1243 ip6_route_fail:
1244 #ifdef CONFIG_PROC_FS
1245         if6_proc_exit();
1246 proc_if6_fail:
1247         ipv6_misc_proc_exit();
1248 proc_misc6_fail:
1249         udplite6_proc_exit();
1250 proc_udplite6_fail:
1251         raw6_proc_exit();
1252 proc_raw6_fail:
1253 #endif
1254         ipv6_netfilter_fini();
1255 netfilter_fail:
1256         igmp6_cleanup();
1257 igmp_fail:
1258         ndisc_cleanup();
1259 ndisc_fail:
1260         icmpv6_cleanup();
1261 icmp_fail:
1262         ip6_mr_cleanup();
1263 ipmr_fail:
1264         unregister_pernet_subsys(&inet6_net_ops);
1265 register_pernet_fail:
1266         sock_unregister(PF_INET6);
1267         rtnl_unregister_all(PF_INET6);
1268 out_sock_register_fail:
1269         rawv6_exit();
1270 out_unregister_ping_proto:
1271         proto_unregister(&pingv6_prot);
1272 out_unregister_raw_proto:
1273         proto_unregister(&rawv6_prot);
1274 out_unregister_udplite_proto:
1275         proto_unregister(&udplitev6_prot);
1276 out_unregister_udp_proto:
1277         proto_unregister(&udpv6_prot);
1278 out_unregister_tcp_proto:
1279         proto_unregister(&tcpv6_prot);
1280         goto out;
1281 }
1282 module_init(inet6_init);
1283
1284 MODULE_ALIAS_NETPROTO(PF_INET6);