2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * PF_INET protocol family socket handler.
8 * Version: $Id: af_inet.c,v 1.137 2002/02/01 22:01:03 davem Exp $
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Alan Cox, <A.Cox@swansea.ac.uk>
15 * Changes (see also sock.c)
18 * Karl Knutson : Socket protocol table
19 * A.N.Kuznetsov : Socket death error in accept().
20 * John Richardson : Fix non blocking error in connect()
21 * so sockets that fail to connect
22 * don't return -EINPROGRESS.
23 * Alan Cox : Asynchronous I/O support
24 * Alan Cox : Keep correct socket pointer on sock
27 * Alan Cox : Semantics of SO_LINGER aren't state
28 * moved to close when you look carefully.
29 * With this fixed and the accept bug fixed
30 * some RPC stuff seems happier.
31 * Niibe Yutaka : 4.4BSD style write async I/O
33 * Tony Gale : Fixed reuse semantics.
34 * Alan Cox : bind() shouldn't abort existing but dead
35 * sockets. Stops FTP netin:.. I hope.
36 * Alan Cox : bind() works correctly for RAW sockets.
37 * Note that FreeBSD at least was broken
38 * in this respect so be careful with
39 * compatibility tests...
40 * Alan Cox : routing cache support
41 * Alan Cox : memzero the socket structure for
43 * Matt Day : nonblock connect error handler
44 * Alan Cox : Allow large numbers of pending sockets
45 * (eg for big web sites), but only if
46 * specifically application requested.
47 * Alan Cox : New buffering throughout IP. Used
49 * Alan Cox : New buffering now used smartly.
50 * Alan Cox : BSD rather than common sense
51 * interpretation of listen.
52 * Germano Caronni : Assorted small races.
53 * Alan Cox : sendmsg/recvmsg basic support.
54 * Alan Cox : Only sendmsg/recvmsg now supported.
55 * Alan Cox : Locked down bind (see security list).
56 * Alan Cox : Loosened bind a little.
57 * Mike McLagan : ADD/DEL DLCI Ioctls
58 * Willy Konynenberg : Transparent proxying support.
59 * David S. Miller : New socket lookup architecture.
60 * Some other random speedups.
61 * Cyrus Durgin : Cleaned up file for kmod hacks.
62 * Andi Kleen : Fix inet_stream_connect TCP race.
64 * This program is free software; you can redistribute it and/or
65 * modify it under the terms of the GNU General Public License
66 * as published by the Free Software Foundation; either version
67 * 2 of the License, or (at your option) any later version.
70 #include <linux/err.h>
71 #include <linux/errno.h>
72 #include <linux/types.h>
73 #include <linux/socket.h>
75 #include <linux/kernel.h>
76 #include <linux/module.h>
77 #include <linux/sched.h>
78 #include <linux/timer.h>
79 #include <linux/string.h>
80 #include <linux/sockios.h>
81 #include <linux/net.h>
82 #include <linux/capability.h>
83 #include <linux/fcntl.h>
85 #include <linux/interrupt.h>
86 #include <linux/stat.h>
87 #include <linux/init.h>
88 #include <linux/poll.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
92 #include <asm/uaccess.h>
93 #include <asm/system.h>
95 #include <linux/inet.h>
96 #include <linux/igmp.h>
97 #include <linux/inetdevice.h>
98 #include <linux/netdevice.h>
100 #include <net/protocol.h>
102 #include <net/route.h>
103 #include <net/ip_fib.h>
104 #include <net/inet_connection_sock.h>
107 #include <net/udplite.h>
108 #include <linux/skbuff.h>
109 #include <net/sock.h>
111 #include <net/icmp.h>
112 #include <net/ipip.h>
113 #include <net/inet_common.h>
114 #include <net/xfrm.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
119 DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly;
121 extern void ip_mc_drop_socket(struct sock *sk);
123 /* The inetsw table contains everything that inet_create needs to
124 * build a new socket.
126 static struct list_head inetsw[SOCK_MAX];
127 static DEFINE_SPINLOCK(inetsw_lock);
129 struct ipv4_config ipv4_config;
131 EXPORT_SYMBOL(ipv4_config);
133 /* New destruction routine */
135 void inet_sock_destruct(struct sock *sk)
137 struct inet_sock *inet = inet_sk(sk);
139 __skb_queue_purge(&sk->sk_receive_queue);
140 __skb_queue_purge(&sk->sk_error_queue);
144 if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
145 printk("Attempt to release TCP socket in state %d %p\n",
149 if (!sock_flag(sk, SOCK_DEAD)) {
150 printk("Attempt to release alive inet socket %p\n", sk);
154 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
155 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
156 BUG_TRAP(!sk->sk_wmem_queued);
157 BUG_TRAP(!sk->sk_forward_alloc);
160 dst_release(sk->sk_dst_cache);
161 sk_refcnt_debug_dec(sk);
165 * The routines beyond this point handle the behaviour of an AF_INET
166 * socket object. Mostly it punts to the subprotocols of IP to do
171 * Automatically bind an unbound socket.
174 static int inet_autobind(struct sock *sk)
176 struct inet_sock *inet;
177 /* We may need to bind the socket. */
181 if (sk->sk_prot->get_port(sk, 0)) {
185 inet->sport = htons(inet->num);
192 * Move a socket into listening state.
194 int inet_listen(struct socket *sock, int backlog)
196 struct sock *sk = sock->sk;
197 unsigned char old_state;
203 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
206 old_state = sk->sk_state;
207 if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
210 /* Really, if the socket is already in listen state
211 * we can only allow the backlog to be adjusted.
213 if (old_state != TCP_LISTEN) {
214 err = inet_csk_listen_start(sk, backlog);
218 sk->sk_max_ack_backlog = backlog;
226 u32 inet_ehash_secret __read_mostly;
227 EXPORT_SYMBOL(inet_ehash_secret);
230 * inet_ehash_secret must be set exactly once
231 * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
233 void build_ehash_secret(void)
237 get_random_bytes(&rnd, sizeof(rnd));
239 spin_lock_bh(&inetsw_lock);
240 if (!inet_ehash_secret)
241 inet_ehash_secret = rnd;
242 spin_unlock_bh(&inetsw_lock);
244 EXPORT_SYMBOL(build_ehash_secret);
247 * Create an inet socket.
250 static int inet_create(struct net *net, struct socket *sock, int protocol)
254 struct inet_protosw *answer;
255 struct inet_sock *inet;
256 struct proto *answer_prot;
257 unsigned char answer_flags;
258 char answer_no_check;
259 int try_loading_module = 0;
262 if (net != &init_net)
263 return -EAFNOSUPPORT;
265 if (sock->type != SOCK_RAW &&
266 sock->type != SOCK_DGRAM &&
268 build_ehash_secret();
270 sock->state = SS_UNCONNECTED;
272 /* Look for the requested type/protocol pair. */
275 err = -ESOCKTNOSUPPORT;
277 list_for_each_rcu(p, &inetsw[sock->type]) {
278 answer = list_entry(p, struct inet_protosw, list);
280 /* Check the non-wild match. */
281 if (protocol == answer->protocol) {
282 if (protocol != IPPROTO_IP)
285 /* Check for the two wild cases. */
286 if (IPPROTO_IP == protocol) {
287 protocol = answer->protocol;
290 if (IPPROTO_IP == answer->protocol)
293 err = -EPROTONOSUPPORT;
297 if (unlikely(answer == NULL)) {
298 if (try_loading_module < 2) {
301 * Be more specific, e.g. net-pf-2-proto-132-type-1
302 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
304 if (++try_loading_module == 1)
305 request_module("net-pf-%d-proto-%d-type-%d",
306 PF_INET, protocol, sock->type);
308 * Fall back to generic, e.g. net-pf-2-proto-132
309 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
312 request_module("net-pf-%d-proto-%d",
314 goto lookup_protocol;
320 if (answer->capability > 0 && !capable(answer->capability))
323 sock->ops = answer->ops;
324 answer_prot = answer->prot;
325 answer_no_check = answer->no_check;
326 answer_flags = answer->flags;
329 BUG_TRAP(answer_prot->slab != NULL);
332 sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
337 sk->sk_no_check = answer_no_check;
338 if (INET_PROTOSW_REUSE & answer_flags)
342 inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
344 if (SOCK_RAW == sock->type) {
345 inet->num = protocol;
346 if (IPPROTO_RAW == protocol)
350 if (ipv4_config.no_pmtu_disc)
351 inet->pmtudisc = IP_PMTUDISC_DONT;
353 inet->pmtudisc = IP_PMTUDISC_WANT;
357 sock_init_data(sock, sk);
359 sk->sk_destruct = inet_sock_destruct;
360 sk->sk_family = PF_INET;
361 sk->sk_protocol = protocol;
362 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
368 inet->mc_list = NULL;
370 sk_refcnt_debug_inc(sk);
373 /* It assumes that any protocol which allows
374 * the user to assign a number at socket
375 * creation time automatically
378 inet->sport = htons(inet->num);
379 /* Add to protocol hash chains. */
380 sk->sk_prot->hash(sk);
383 if (sk->sk_prot->init) {
384 err = sk->sk_prot->init(sk);
386 sk_common_release(sk);
397 * The peer socket should always be NULL (or else). When we call this
398 * function we are destroying the object and from then on nobody
399 * should refer to it.
401 int inet_release(struct socket *sock)
403 struct sock *sk = sock->sk;
408 /* Applications forget to leave groups before exiting */
409 ip_mc_drop_socket(sk);
411 /* If linger is set, we don't return until the close
412 * is complete. Otherwise we return immediately. The
413 * actually closing is done the same either way.
415 * If the close is due to the process exiting, we never
419 if (sock_flag(sk, SOCK_LINGER) &&
420 !(current->flags & PF_EXITING))
421 timeout = sk->sk_lingertime;
423 sk->sk_prot->close(sk, timeout);
428 /* It is off by default, see below. */
429 int sysctl_ip_nonlocal_bind __read_mostly;
431 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
433 struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
434 struct sock *sk = sock->sk;
435 struct inet_sock *inet = inet_sk(sk);
440 /* If the socket has its own bind function then use it. (RAW) */
441 if (sk->sk_prot->bind) {
442 err = sk->sk_prot->bind(sk, uaddr, addr_len);
446 if (addr_len < sizeof(struct sockaddr_in))
449 chk_addr_ret = inet_addr_type(&init_net, addr->sin_addr.s_addr);
451 /* Not specified by any standard per-se, however it breaks too
452 * many applications when removed. It is unfortunate since
453 * allowing applications to make a non-local bind solves
454 * several problems with systems using dynamic addressing.
455 * (ie. your servers still start up even if your ISDN link
456 * is temporarily down)
458 err = -EADDRNOTAVAIL;
459 if (!sysctl_ip_nonlocal_bind &&
461 addr->sin_addr.s_addr != INADDR_ANY &&
462 chk_addr_ret != RTN_LOCAL &&
463 chk_addr_ret != RTN_MULTICAST &&
464 chk_addr_ret != RTN_BROADCAST)
467 snum = ntohs(addr->sin_port);
469 if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
472 /* We keep a pair of addresses. rcv_saddr is the one
473 * used by hash lookups, and saddr is used for transmit.
475 * In the BSD API these are the same except where it
476 * would be illegal to use them (multicast/broadcast) in
477 * which case the sending device address is used.
481 /* Check these errors (active socket, double bind). */
483 if (sk->sk_state != TCP_CLOSE || inet->num)
484 goto out_release_sock;
486 inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
487 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
488 inet->saddr = 0; /* Use device */
490 /* Make sure we are allowed to bind here. */
491 if (sk->sk_prot->get_port(sk, snum)) {
492 inet->saddr = inet->rcv_saddr = 0;
494 goto out_release_sock;
498 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
500 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
501 inet->sport = htons(inet->num);
512 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
513 int addr_len, int flags)
515 struct sock *sk = sock->sk;
517 if (uaddr->sa_family == AF_UNSPEC)
518 return sk->sk_prot->disconnect(sk, flags);
520 if (!inet_sk(sk)->num && inet_autobind(sk))
522 return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
525 static long inet_wait_for_connect(struct sock *sk, long timeo)
529 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
531 /* Basic assumption: if someone sets sk->sk_err, he _must_
532 * change state of the socket from TCP_SYN_*.
533 * Connect() does not allow to get error notifications
534 * without closing the socket.
536 while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
538 timeo = schedule_timeout(timeo);
540 if (signal_pending(current) || !timeo)
542 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
544 finish_wait(sk->sk_sleep, &wait);
549 * Connect to a remote host. There is regrettably still a little
550 * TCP 'magic' in here.
552 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
553 int addr_len, int flags)
555 struct sock *sk = sock->sk;
561 if (uaddr->sa_family == AF_UNSPEC) {
562 err = sk->sk_prot->disconnect(sk, flags);
563 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
567 switch (sock->state) {
576 /* Fall out of switch with err, set for this state */
580 if (sk->sk_state != TCP_CLOSE)
583 err = sk->sk_prot->connect(sk, uaddr, addr_len);
587 sock->state = SS_CONNECTING;
589 /* Just entered SS_CONNECTING state; the only
590 * difference is that return value in non-blocking
591 * case is EINPROGRESS, rather than EALREADY.
597 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
599 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
600 /* Error code is set above */
601 if (!timeo || !inet_wait_for_connect(sk, timeo))
604 err = sock_intr_errno(timeo);
605 if (signal_pending(current))
609 /* Connection was closed by RST, timeout, ICMP error
610 * or another process disconnected us.
612 if (sk->sk_state == TCP_CLOSE)
615 /* sk->sk_err may be not zero now, if RECVERR was ordered by user
616 * and error was received after socket entered established state.
617 * Hence, it is handled normally after connect() return successfully.
620 sock->state = SS_CONNECTED;
627 err = sock_error(sk) ? : -ECONNABORTED;
628 sock->state = SS_UNCONNECTED;
629 if (sk->sk_prot->disconnect(sk, flags))
630 sock->state = SS_DISCONNECTING;
635 * Accept a pending connection. The TCP layer now gives BSD semantics.
638 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
640 struct sock *sk1 = sock->sk;
642 struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
649 BUG_TRAP((1 << sk2->sk_state) &
650 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE));
652 sock_graft(sk2, newsock);
654 newsock->state = SS_CONNECTED;
663 * This does both peername and sockname.
665 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
666 int *uaddr_len, int peer)
668 struct sock *sk = sock->sk;
669 struct inet_sock *inet = inet_sk(sk);
670 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
672 sin->sin_family = AF_INET;
675 (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
678 sin->sin_port = inet->dport;
679 sin->sin_addr.s_addr = inet->daddr;
681 __be32 addr = inet->rcv_saddr;
684 sin->sin_port = inet->sport;
685 sin->sin_addr.s_addr = addr;
687 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
688 *uaddr_len = sizeof(*sin);
692 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
695 struct sock *sk = sock->sk;
697 /* We may need to bind the socket. */
698 if (!inet_sk(sk)->num && inet_autobind(sk))
701 return sk->sk_prot->sendmsg(iocb, sk, msg, size);
705 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
707 struct sock *sk = sock->sk;
709 /* We may need to bind the socket. */
710 if (!inet_sk(sk)->num && inet_autobind(sk))
713 if (sk->sk_prot->sendpage)
714 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
715 return sock_no_sendpage(sock, page, offset, size, flags);
719 int inet_shutdown(struct socket *sock, int how)
721 struct sock *sk = sock->sk;
724 /* This should really check to make sure
725 * the socket is a TCP socket. (WHY AC...)
727 how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
730 if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */
734 if (sock->state == SS_CONNECTING) {
735 if ((1 << sk->sk_state) &
736 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
737 sock->state = SS_DISCONNECTING;
739 sock->state = SS_CONNECTED;
742 switch (sk->sk_state) {
745 /* Hack to wake up other listeners, who can poll for
746 POLLHUP, even on eg. unconnected UDP sockets -- RR */
748 sk->sk_shutdown |= how;
749 if (sk->sk_prot->shutdown)
750 sk->sk_prot->shutdown(sk, how);
753 /* Remaining two branches are temporary solution for missing
754 * close() in multithreaded environment. It is _not_ a good idea,
755 * but we have no choice until close() is repaired at VFS level.
758 if (!(how & RCV_SHUTDOWN))
762 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
763 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
767 /* Wake up anyone sleeping in poll. */
768 sk->sk_state_change(sk);
774 * ioctl() calls you can issue on an INET socket. Most of these are
775 * device configuration and stuff and very rarely used. Some ioctls
776 * pass on to the socket itself.
778 * NOTE: I like the idea of a module for the config stuff. ie ifconfig
779 * loads the devconfigure module does its configuring and unloads it.
780 * There's a good 20K of config code hanging around the kernel.
783 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
785 struct sock *sk = sock->sk;
790 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
793 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
798 err = ip_rt_ioctl(sk->sk_net, cmd, (void __user *)arg);
803 err = arp_ioctl(sk->sk_net, cmd, (void __user *)arg);
816 err = devinet_ioctl(cmd, (void __user *)arg);
819 if (sk->sk_prot->ioctl)
820 err = sk->sk_prot->ioctl(sk, cmd, arg);
828 const struct proto_ops inet_stream_ops = {
830 .owner = THIS_MODULE,
831 .release = inet_release,
833 .connect = inet_stream_connect,
834 .socketpair = sock_no_socketpair,
835 .accept = inet_accept,
836 .getname = inet_getname,
839 .listen = inet_listen,
840 .shutdown = inet_shutdown,
841 .setsockopt = sock_common_setsockopt,
842 .getsockopt = sock_common_getsockopt,
843 .sendmsg = tcp_sendmsg,
844 .recvmsg = sock_common_recvmsg,
845 .mmap = sock_no_mmap,
846 .sendpage = tcp_sendpage,
847 .splice_read = tcp_splice_read,
849 .compat_setsockopt = compat_sock_common_setsockopt,
850 .compat_getsockopt = compat_sock_common_getsockopt,
854 const struct proto_ops inet_dgram_ops = {
856 .owner = THIS_MODULE,
857 .release = inet_release,
859 .connect = inet_dgram_connect,
860 .socketpair = sock_no_socketpair,
861 .accept = sock_no_accept,
862 .getname = inet_getname,
865 .listen = sock_no_listen,
866 .shutdown = inet_shutdown,
867 .setsockopt = sock_common_setsockopt,
868 .getsockopt = sock_common_getsockopt,
869 .sendmsg = inet_sendmsg,
870 .recvmsg = sock_common_recvmsg,
871 .mmap = sock_no_mmap,
872 .sendpage = inet_sendpage,
874 .compat_setsockopt = compat_sock_common_setsockopt,
875 .compat_getsockopt = compat_sock_common_getsockopt,
880 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
883 static const struct proto_ops inet_sockraw_ops = {
885 .owner = THIS_MODULE,
886 .release = inet_release,
888 .connect = inet_dgram_connect,
889 .socketpair = sock_no_socketpair,
890 .accept = sock_no_accept,
891 .getname = inet_getname,
892 .poll = datagram_poll,
894 .listen = sock_no_listen,
895 .shutdown = inet_shutdown,
896 .setsockopt = sock_common_setsockopt,
897 .getsockopt = sock_common_getsockopt,
898 .sendmsg = inet_sendmsg,
899 .recvmsg = sock_common_recvmsg,
900 .mmap = sock_no_mmap,
901 .sendpage = inet_sendpage,
903 .compat_setsockopt = compat_sock_common_setsockopt,
904 .compat_getsockopt = compat_sock_common_getsockopt,
908 static struct net_proto_family inet_family_ops = {
910 .create = inet_create,
911 .owner = THIS_MODULE,
914 /* Upon startup we insert all the elements in inetsw_array[] into
915 * the linked list inetsw.
917 static struct inet_protosw inetsw_array[] =
921 .protocol = IPPROTO_TCP,
923 .ops = &inet_stream_ops,
926 .flags = INET_PROTOSW_PERMANENT |
932 .protocol = IPPROTO_UDP,
934 .ops = &inet_dgram_ops,
936 .no_check = UDP_CSUM_DEFAULT,
937 .flags = INET_PROTOSW_PERMANENT,
943 .protocol = IPPROTO_IP, /* wild card */
945 .ops = &inet_sockraw_ops,
946 .capability = CAP_NET_RAW,
947 .no_check = UDP_CSUM_DEFAULT,
948 .flags = INET_PROTOSW_REUSE,
952 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
954 void inet_register_protosw(struct inet_protosw *p)
956 struct list_head *lh;
957 struct inet_protosw *answer;
958 int protocol = p->protocol;
959 struct list_head *last_perm;
961 spin_lock_bh(&inetsw_lock);
963 if (p->type >= SOCK_MAX)
966 /* If we are trying to override a permanent protocol, bail. */
968 last_perm = &inetsw[p->type];
969 list_for_each(lh, &inetsw[p->type]) {
970 answer = list_entry(lh, struct inet_protosw, list);
972 /* Check only the non-wild match. */
973 if (INET_PROTOSW_PERMANENT & answer->flags) {
974 if (protocol == answer->protocol)
984 /* Add the new entry after the last permanent entry if any, so that
985 * the new entry does not override a permanent entry when matched with
986 * a wild-card protocol. But it is allowed to override any existing
987 * non-permanent entry. This means that when we remove this entry, the
988 * system automatically returns to the old behavior.
990 list_add_rcu(&p->list, last_perm);
992 spin_unlock_bh(&inetsw_lock);
999 printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1005 "Ignoring attempt to register invalid socket type %d.\n",
1010 void inet_unregister_protosw(struct inet_protosw *p)
1012 if (INET_PROTOSW_PERMANENT & p->flags) {
1014 "Attempt to unregister permanent protocol %d.\n",
1017 spin_lock_bh(&inetsw_lock);
1018 list_del_rcu(&p->list);
1019 spin_unlock_bh(&inetsw_lock);
1026 * Shall we try to damage output packets if routing dev changes?
1029 int sysctl_ip_dynaddr __read_mostly;
1031 static int inet_sk_reselect_saddr(struct sock *sk)
1033 struct inet_sock *inet = inet_sk(sk);
1036 __be32 old_saddr = inet->saddr;
1038 __be32 daddr = inet->daddr;
1040 if (inet->opt && inet->opt->srr)
1041 daddr = inet->opt->faddr;
1043 /* Query new route. */
1044 err = ip_route_connect(&rt, daddr, 0,
1046 sk->sk_bound_dev_if,
1048 inet->sport, inet->dport, sk, 0);
1052 sk_setup_caps(sk, &rt->u.dst);
1054 new_saddr = rt->rt_src;
1056 if (new_saddr == old_saddr)
1059 if (sysctl_ip_dynaddr > 1) {
1060 printk(KERN_INFO "%s(): shifting inet->"
1061 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
1064 NIPQUAD(new_saddr));
1067 inet->saddr = inet->rcv_saddr = new_saddr;
1070 * XXX The only one ugly spot where we need to
1071 * XXX really change the sockets identity after
1072 * XXX it has entered the hashes. -DaveM
1074 * Besides that, it does not check for connection
1075 * uniqueness. Wait for troubles.
1077 __sk_prot_rehash(sk);
1081 int inet_sk_rebuild_header(struct sock *sk)
1083 struct inet_sock *inet = inet_sk(sk);
1084 struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1088 /* Route is OK, nothing to do. */
1093 daddr = inet->daddr;
1094 if (inet->opt && inet->opt->srr)
1095 daddr = inet->opt->faddr;
1098 .oif = sk->sk_bound_dev_if,
1102 .saddr = inet->saddr,
1103 .tos = RT_CONN_FLAGS(sk),
1106 .proto = sk->sk_protocol,
1109 .sport = inet->sport,
1110 .dport = inet->dport,
1115 security_sk_classify_flow(sk, &fl);
1116 err = ip_route_output_flow(&init_net, &rt, &fl, sk, 0);
1119 sk_setup_caps(sk, &rt->u.dst);
1121 /* Routing failed... */
1122 sk->sk_route_caps = 0;
1124 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1125 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1127 if (!sysctl_ip_dynaddr ||
1128 sk->sk_state != TCP_SYN_SENT ||
1129 (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1130 (err = inet_sk_reselect_saddr(sk)) != 0)
1131 sk->sk_err_soft = -err;
1137 EXPORT_SYMBOL(inet_sk_rebuild_header);
1139 static int inet_gso_send_check(struct sk_buff *skb)
1142 struct net_protocol *ops;
1147 if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1152 if (ihl < sizeof(*iph))
1155 if (unlikely(!pskb_may_pull(skb, ihl)))
1158 __skb_pull(skb, ihl);
1159 skb_reset_transport_header(skb);
1161 proto = iph->protocol & (MAX_INET_PROTOS - 1);
1162 err = -EPROTONOSUPPORT;
1165 ops = rcu_dereference(inet_protos[proto]);
1166 if (likely(ops && ops->gso_send_check))
1167 err = ops->gso_send_check(skb);
1174 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1176 struct sk_buff *segs = ERR_PTR(-EINVAL);
1178 struct net_protocol *ops;
1183 if (!(features & NETIF_F_V4_CSUM))
1184 features &= ~NETIF_F_SG;
1186 if (unlikely(skb_shinfo(skb)->gso_type &
1194 if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1199 if (ihl < sizeof(*iph))
1202 if (unlikely(!pskb_may_pull(skb, ihl)))
1205 __skb_pull(skb, ihl);
1206 skb_reset_transport_header(skb);
1208 id = ntohs(iph->id);
1209 proto = iph->protocol & (MAX_INET_PROTOS - 1);
1210 segs = ERR_PTR(-EPROTONOSUPPORT);
1213 ops = rcu_dereference(inet_protos[proto]);
1214 if (likely(ops && ops->gso_segment))
1215 segs = ops->gso_segment(skb, features);
1218 if (!segs || unlikely(IS_ERR(segs)))
1224 iph->id = htons(id++);
1225 iph->tot_len = htons(skb->len - skb->mac_len);
1227 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1228 } while ((skb = skb->next));
1234 unsigned long snmp_fold_field(void *mib[], int offt)
1236 unsigned long res = 0;
1239 for_each_possible_cpu(i) {
1240 res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1241 res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1245 EXPORT_SYMBOL_GPL(snmp_fold_field);
1247 int snmp_mib_init(void *ptr[2], size_t mibsize)
1249 BUG_ON(ptr == NULL);
1250 ptr[0] = __alloc_percpu(mibsize);
1253 ptr[1] = __alloc_percpu(mibsize);
1258 free_percpu(ptr[0]);
1263 EXPORT_SYMBOL_GPL(snmp_mib_init);
1265 void snmp_mib_free(void *ptr[2])
1267 BUG_ON(ptr == NULL);
1268 free_percpu(ptr[0]);
1269 free_percpu(ptr[1]);
1270 ptr[0] = ptr[1] = NULL;
1272 EXPORT_SYMBOL_GPL(snmp_mib_free);
1274 #ifdef CONFIG_IP_MULTICAST
1275 static struct net_protocol igmp_protocol = {
1276 .handler = igmp_rcv,
1280 static struct net_protocol tcp_protocol = {
1281 .handler = tcp_v4_rcv,
1282 .err_handler = tcp_v4_err,
1283 .gso_send_check = tcp_v4_gso_send_check,
1284 .gso_segment = tcp_tso_segment,
1288 static struct net_protocol udp_protocol = {
1290 .err_handler = udp_err,
1294 static struct net_protocol icmp_protocol = {
1295 .handler = icmp_rcv,
1299 static int __init init_ipv4_mibs(void)
1301 if (snmp_mib_init((void **)net_statistics,
1302 sizeof(struct linux_mib)) < 0)
1304 if (snmp_mib_init((void **)ip_statistics,
1305 sizeof(struct ipstats_mib)) < 0)
1307 if (snmp_mib_init((void **)icmp_statistics,
1308 sizeof(struct icmp_mib)) < 0)
1310 if (snmp_mib_init((void **)icmpmsg_statistics,
1311 sizeof(struct icmpmsg_mib)) < 0)
1312 goto err_icmpmsg_mib;
1313 if (snmp_mib_init((void **)tcp_statistics,
1314 sizeof(struct tcp_mib)) < 0)
1316 if (snmp_mib_init((void **)udp_statistics,
1317 sizeof(struct udp_mib)) < 0)
1319 if (snmp_mib_init((void **)udplite_statistics,
1320 sizeof(struct udp_mib)) < 0)
1321 goto err_udplite_mib;
1328 snmp_mib_free((void **)udp_statistics);
1330 snmp_mib_free((void **)tcp_statistics);
1332 snmp_mib_free((void **)icmpmsg_statistics);
1334 snmp_mib_free((void **)icmp_statistics);
1336 snmp_mib_free((void **)ip_statistics);
1338 snmp_mib_free((void **)net_statistics);
1343 static int ipv4_proc_init(void);
1346 * IP protocol layer initialiser
1349 static struct packet_type ip_packet_type = {
1350 .type = __constant_htons(ETH_P_IP),
1352 .gso_send_check = inet_gso_send_check,
1353 .gso_segment = inet_gso_segment,
1356 static int __init inet_init(void)
1358 struct sk_buff *dummy_skb;
1359 struct inet_protosw *q;
1360 struct list_head *r;
1363 BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1365 rc = proto_register(&tcp_prot, 1);
1369 rc = proto_register(&udp_prot, 1);
1371 goto out_unregister_tcp_proto;
1373 rc = proto_register(&raw_prot, 1);
1375 goto out_unregister_udp_proto;
1378 * Tell SOCKET that we are alive...
1381 (void)sock_register(&inet_family_ops);
1384 * Add all the base protocols.
1387 if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1388 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1389 if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1390 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1391 if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1392 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1393 #ifdef CONFIG_IP_MULTICAST
1394 if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1395 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1398 /* Register the socket-side information for inet_create. */
1399 for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1402 for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1403 inet_register_protosw(q);
1406 * Set the ARP module up
1412 * Set the IP module up
1417 tcp_v4_init(&inet_family_ops);
1419 /* Setup TCP slab cache for open requests. */
1422 /* Setup UDP memory threshold */
1425 /* Add UDP-Lite (RFC 3828) */
1426 udplite4_register();
1429 * Set the ICMP layer up
1432 icmp_init(&inet_family_ops);
1435 * Initialise the multicast router
1437 #if defined(CONFIG_IP_MROUTE)
1441 * Initialise per-cpu ipv4 mibs
1444 if (init_ipv4_mibs())
1445 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ;
1451 dev_add_pack(&ip_packet_type);
1456 out_unregister_udp_proto:
1457 proto_unregister(&udp_prot);
1458 out_unregister_tcp_proto:
1459 proto_unregister(&tcp_prot);
1463 fs_initcall(inet_init);
1465 /* ------------------------------------------------------------------------ */
1467 #ifdef CONFIG_PROC_FS
1468 static int __init ipv4_proc_init(void)
1472 if (raw_proc_init())
1474 if (tcp4_proc_init())
1476 if (udp4_proc_init())
1478 if (ip_misc_proc_init())
1493 #else /* CONFIG_PROC_FS */
1494 static int __init ipv4_proc_init(void)
1498 #endif /* CONFIG_PROC_FS */
1500 MODULE_ALIAS_NETPROTO(PF_INET);
1502 EXPORT_SYMBOL(inet_accept);
1503 EXPORT_SYMBOL(inet_bind);
1504 EXPORT_SYMBOL(inet_dgram_connect);
1505 EXPORT_SYMBOL(inet_dgram_ops);
1506 EXPORT_SYMBOL(inet_getname);
1507 EXPORT_SYMBOL(inet_ioctl);
1508 EXPORT_SYMBOL(inet_listen);
1509 EXPORT_SYMBOL(inet_register_protosw);
1510 EXPORT_SYMBOL(inet_release);
1511 EXPORT_SYMBOL(inet_sendmsg);
1512 EXPORT_SYMBOL(inet_shutdown);
1513 EXPORT_SYMBOL(inet_sock_destruct);
1514 EXPORT_SYMBOL(inet_stream_connect);
1515 EXPORT_SYMBOL(inet_stream_ops);
1516 EXPORT_SYMBOL(inet_unregister_protosw);
1517 EXPORT_SYMBOL(net_statistics);
1518 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);