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 /* New destruction routine */
131 void inet_sock_destruct(struct sock *sk)
133 struct inet_sock *inet = inet_sk(sk);
135 __skb_queue_purge(&sk->sk_receive_queue);
136 __skb_queue_purge(&sk->sk_error_queue);
138 if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
139 printk("Attempt to release TCP socket in state %d %p\n",
143 if (!sock_flag(sk, SOCK_DEAD)) {
144 printk("Attempt to release alive inet socket %p\n", sk);
148 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
149 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
150 BUG_TRAP(!sk->sk_wmem_queued);
151 BUG_TRAP(!sk->sk_forward_alloc);
154 dst_release(sk->sk_dst_cache);
155 sk_refcnt_debug_dec(sk);
159 * The routines beyond this point handle the behaviour of an AF_INET
160 * socket object. Mostly it punts to the subprotocols of IP to do
165 * Automatically bind an unbound socket.
168 static int inet_autobind(struct sock *sk)
170 struct inet_sock *inet;
171 /* We may need to bind the socket. */
175 if (sk->sk_prot->get_port(sk, 0)) {
179 inet->sport = htons(inet->num);
186 * Move a socket into listening state.
188 int inet_listen(struct socket *sock, int backlog)
190 struct sock *sk = sock->sk;
191 unsigned char old_state;
197 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
200 old_state = sk->sk_state;
201 if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
204 /* Really, if the socket is already in listen state
205 * we can only allow the backlog to be adjusted.
207 if (old_state != TCP_LISTEN) {
208 err = inet_csk_listen_start(sk, backlog);
212 sk->sk_max_ack_backlog = backlog;
220 u32 inet_ehash_secret __read_mostly;
221 EXPORT_SYMBOL(inet_ehash_secret);
224 * inet_ehash_secret must be set exactly once
225 * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
227 void build_ehash_secret(void)
231 get_random_bytes(&rnd, sizeof(rnd));
233 spin_lock_bh(&inetsw_lock);
234 if (!inet_ehash_secret)
235 inet_ehash_secret = rnd;
236 spin_unlock_bh(&inetsw_lock);
238 EXPORT_SYMBOL(build_ehash_secret);
241 * Create an inet socket.
244 static int inet_create(struct socket *sock, int protocol)
248 struct inet_protosw *answer;
249 struct inet_sock *inet;
250 struct proto *answer_prot;
251 unsigned char answer_flags;
252 char answer_no_check;
253 int try_loading_module = 0;
256 if (sock->type != SOCK_RAW &&
257 sock->type != SOCK_DGRAM &&
259 build_ehash_secret();
261 sock->state = SS_UNCONNECTED;
263 /* Look for the requested type/protocol pair. */
266 err = -ESOCKTNOSUPPORT;
268 list_for_each_rcu(p, &inetsw[sock->type]) {
269 answer = list_entry(p, struct inet_protosw, list);
271 /* Check the non-wild match. */
272 if (protocol == answer->protocol) {
273 if (protocol != IPPROTO_IP)
276 /* Check for the two wild cases. */
277 if (IPPROTO_IP == protocol) {
278 protocol = answer->protocol;
281 if (IPPROTO_IP == answer->protocol)
284 err = -EPROTONOSUPPORT;
288 if (unlikely(answer == NULL)) {
289 if (try_loading_module < 2) {
292 * Be more specific, e.g. net-pf-2-proto-132-type-1
293 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
295 if (++try_loading_module == 1)
296 request_module("net-pf-%d-proto-%d-type-%d",
297 PF_INET, protocol, sock->type);
299 * Fall back to generic, e.g. net-pf-2-proto-132
300 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
303 request_module("net-pf-%d-proto-%d",
305 goto lookup_protocol;
311 if (answer->capability > 0 && !capable(answer->capability))
314 sock->ops = answer->ops;
315 answer_prot = answer->prot;
316 answer_no_check = answer->no_check;
317 answer_flags = answer->flags;
320 BUG_TRAP(answer_prot->slab != NULL);
323 sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1);
328 sk->sk_no_check = answer_no_check;
329 if (INET_PROTOSW_REUSE & answer_flags)
333 inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
335 if (SOCK_RAW == sock->type) {
336 inet->num = protocol;
337 if (IPPROTO_RAW == protocol)
341 if (ipv4_config.no_pmtu_disc)
342 inet->pmtudisc = IP_PMTUDISC_DONT;
344 inet->pmtudisc = IP_PMTUDISC_WANT;
348 sock_init_data(sock, sk);
350 sk->sk_destruct = inet_sock_destruct;
351 sk->sk_family = PF_INET;
352 sk->sk_protocol = protocol;
353 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
359 inet->mc_list = NULL;
361 sk_refcnt_debug_inc(sk);
364 /* It assumes that any protocol which allows
365 * the user to assign a number at socket
366 * creation time automatically
369 inet->sport = htons(inet->num);
370 /* Add to protocol hash chains. */
371 sk->sk_prot->hash(sk);
374 if (sk->sk_prot->init) {
375 err = sk->sk_prot->init(sk);
377 sk_common_release(sk);
388 * The peer socket should always be NULL (or else). When we call this
389 * function we are destroying the object and from then on nobody
390 * should refer to it.
392 int inet_release(struct socket *sock)
394 struct sock *sk = sock->sk;
399 /* Applications forget to leave groups before exiting */
400 ip_mc_drop_socket(sk);
402 /* If linger is set, we don't return until the close
403 * is complete. Otherwise we return immediately. The
404 * actually closing is done the same either way.
406 * If the close is due to the process exiting, we never
410 if (sock_flag(sk, SOCK_LINGER) &&
411 !(current->flags & PF_EXITING))
412 timeout = sk->sk_lingertime;
414 sk->sk_prot->close(sk, timeout);
419 /* It is off by default, see below. */
420 int sysctl_ip_nonlocal_bind __read_mostly;
422 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
424 struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
425 struct sock *sk = sock->sk;
426 struct inet_sock *inet = inet_sk(sk);
431 /* If the socket has its own bind function then use it. (RAW) */
432 if (sk->sk_prot->bind) {
433 err = sk->sk_prot->bind(sk, uaddr, addr_len);
437 if (addr_len < sizeof(struct sockaddr_in))
440 chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr);
442 /* Not specified by any standard per-se, however it breaks too
443 * many applications when removed. It is unfortunate since
444 * allowing applications to make a non-local bind solves
445 * several problems with systems using dynamic addressing.
446 * (ie. your servers still start up even if your ISDN link
447 * is temporarily down)
449 err = -EADDRNOTAVAIL;
450 if (!sysctl_ip_nonlocal_bind &&
452 addr->sin_addr.s_addr != INADDR_ANY &&
453 chk_addr_ret != RTN_LOCAL &&
454 chk_addr_ret != RTN_MULTICAST &&
455 chk_addr_ret != RTN_BROADCAST)
458 snum = ntohs(addr->sin_port);
460 if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
463 /* We keep a pair of addresses. rcv_saddr is the one
464 * used by hash lookups, and saddr is used for transmit.
466 * In the BSD API these are the same except where it
467 * would be illegal to use them (multicast/broadcast) in
468 * which case the sending device address is used.
472 /* Check these errors (active socket, double bind). */
474 if (sk->sk_state != TCP_CLOSE || inet->num)
475 goto out_release_sock;
477 inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
478 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
479 inet->saddr = 0; /* Use device */
481 /* Make sure we are allowed to bind here. */
482 if (sk->sk_prot->get_port(sk, snum)) {
483 inet->saddr = inet->rcv_saddr = 0;
485 goto out_release_sock;
489 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
491 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
492 inet->sport = htons(inet->num);
503 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
504 int addr_len, int flags)
506 struct sock *sk = sock->sk;
508 if (uaddr->sa_family == AF_UNSPEC)
509 return sk->sk_prot->disconnect(sk, flags);
511 if (!inet_sk(sk)->num && inet_autobind(sk))
513 return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
516 static long inet_wait_for_connect(struct sock *sk, long timeo)
520 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
522 /* Basic assumption: if someone sets sk->sk_err, he _must_
523 * change state of the socket from TCP_SYN_*.
524 * Connect() does not allow to get error notifications
525 * without closing the socket.
527 while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
529 timeo = schedule_timeout(timeo);
531 if (signal_pending(current) || !timeo)
533 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
535 finish_wait(sk->sk_sleep, &wait);
540 * Connect to a remote host. There is regrettably still a little
541 * TCP 'magic' in here.
543 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
544 int addr_len, int flags)
546 struct sock *sk = sock->sk;
552 if (uaddr->sa_family == AF_UNSPEC) {
553 err = sk->sk_prot->disconnect(sk, flags);
554 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
558 switch (sock->state) {
567 /* Fall out of switch with err, set for this state */
571 if (sk->sk_state != TCP_CLOSE)
574 err = sk->sk_prot->connect(sk, uaddr, addr_len);
578 sock->state = SS_CONNECTING;
580 /* Just entered SS_CONNECTING state; the only
581 * difference is that return value in non-blocking
582 * case is EINPROGRESS, rather than EALREADY.
588 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
590 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
591 /* Error code is set above */
592 if (!timeo || !inet_wait_for_connect(sk, timeo))
595 err = sock_intr_errno(timeo);
596 if (signal_pending(current))
600 /* Connection was closed by RST, timeout, ICMP error
601 * or another process disconnected us.
603 if (sk->sk_state == TCP_CLOSE)
606 /* sk->sk_err may be not zero now, if RECVERR was ordered by user
607 * and error was received after socket entered established state.
608 * Hence, it is handled normally after connect() return successfully.
611 sock->state = SS_CONNECTED;
618 err = sock_error(sk) ? : -ECONNABORTED;
619 sock->state = SS_UNCONNECTED;
620 if (sk->sk_prot->disconnect(sk, flags))
621 sock->state = SS_DISCONNECTING;
626 * Accept a pending connection. The TCP layer now gives BSD semantics.
629 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
631 struct sock *sk1 = sock->sk;
633 struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
640 BUG_TRAP((1 << sk2->sk_state) &
641 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE));
643 sock_graft(sk2, newsock);
645 newsock->state = SS_CONNECTED;
654 * This does both peername and sockname.
656 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
657 int *uaddr_len, int peer)
659 struct sock *sk = sock->sk;
660 struct inet_sock *inet = inet_sk(sk);
661 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
663 sin->sin_family = AF_INET;
666 (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
669 sin->sin_port = inet->dport;
670 sin->sin_addr.s_addr = inet->daddr;
672 __be32 addr = inet->rcv_saddr;
675 sin->sin_port = inet->sport;
676 sin->sin_addr.s_addr = addr;
678 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
679 *uaddr_len = sizeof(*sin);
683 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
686 struct sock *sk = sock->sk;
688 /* We may need to bind the socket. */
689 if (!inet_sk(sk)->num && inet_autobind(sk))
692 return sk->sk_prot->sendmsg(iocb, sk, msg, size);
696 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
698 struct sock *sk = sock->sk;
700 /* We may need to bind the socket. */
701 if (!inet_sk(sk)->num && inet_autobind(sk))
704 if (sk->sk_prot->sendpage)
705 return sk->sk_prot->sendpage(sk, page, offset, size, flags);
706 return sock_no_sendpage(sock, page, offset, size, flags);
710 int inet_shutdown(struct socket *sock, int how)
712 struct sock *sk = sock->sk;
715 /* This should really check to make sure
716 * the socket is a TCP socket. (WHY AC...)
718 how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
721 if ((how & ~SHUTDOWN_MASK) || !how) /* MAXINT->0 */
725 if (sock->state == SS_CONNECTING) {
726 if ((1 << sk->sk_state) &
727 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
728 sock->state = SS_DISCONNECTING;
730 sock->state = SS_CONNECTED;
733 switch (sk->sk_state) {
736 /* Hack to wake up other listeners, who can poll for
737 POLLHUP, even on eg. unconnected UDP sockets -- RR */
739 sk->sk_shutdown |= how;
740 if (sk->sk_prot->shutdown)
741 sk->sk_prot->shutdown(sk, how);
744 /* Remaining two branches are temporary solution for missing
745 * close() in multithreaded environment. It is _not_ a good idea,
746 * but we have no choice until close() is repaired at VFS level.
749 if (!(how & RCV_SHUTDOWN))
753 err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
754 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
758 /* Wake up anyone sleeping in poll. */
759 sk->sk_state_change(sk);
765 * ioctl() calls you can issue on an INET socket. Most of these are
766 * device configuration and stuff and very rarely used. Some ioctls
767 * pass on to the socket itself.
769 * NOTE: I like the idea of a module for the config stuff. ie ifconfig
770 * loads the devconfigure module does its configuring and unloads it.
771 * There's a good 20K of config code hanging around the kernel.
774 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
776 struct sock *sk = sock->sk;
781 err = sock_get_timestamp(sk, (struct timeval __user *)arg);
784 err = sock_get_timestampns(sk, (struct timespec __user *)arg);
789 err = ip_rt_ioctl(cmd, (void __user *)arg);
794 err = arp_ioctl(cmd, (void __user *)arg);
807 err = devinet_ioctl(cmd, (void __user *)arg);
810 if (sk->sk_prot->ioctl)
811 err = sk->sk_prot->ioctl(sk, cmd, arg);
819 const struct proto_ops inet_stream_ops = {
821 .owner = THIS_MODULE,
822 .release = inet_release,
824 .connect = inet_stream_connect,
825 .socketpair = sock_no_socketpair,
826 .accept = inet_accept,
827 .getname = inet_getname,
830 .listen = inet_listen,
831 .shutdown = inet_shutdown,
832 .setsockopt = sock_common_setsockopt,
833 .getsockopt = sock_common_getsockopt,
834 .sendmsg = tcp_sendmsg,
835 .recvmsg = sock_common_recvmsg,
836 .mmap = sock_no_mmap,
837 .sendpage = tcp_sendpage,
839 .compat_setsockopt = compat_sock_common_setsockopt,
840 .compat_getsockopt = compat_sock_common_getsockopt,
844 const struct proto_ops inet_dgram_ops = {
846 .owner = THIS_MODULE,
847 .release = inet_release,
849 .connect = inet_dgram_connect,
850 .socketpair = sock_no_socketpair,
851 .accept = sock_no_accept,
852 .getname = inet_getname,
855 .listen = sock_no_listen,
856 .shutdown = inet_shutdown,
857 .setsockopt = sock_common_setsockopt,
858 .getsockopt = sock_common_getsockopt,
859 .sendmsg = inet_sendmsg,
860 .recvmsg = sock_common_recvmsg,
861 .mmap = sock_no_mmap,
862 .sendpage = inet_sendpage,
864 .compat_setsockopt = compat_sock_common_setsockopt,
865 .compat_getsockopt = compat_sock_common_getsockopt,
870 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
873 static const struct proto_ops inet_sockraw_ops = {
875 .owner = THIS_MODULE,
876 .release = inet_release,
878 .connect = inet_dgram_connect,
879 .socketpair = sock_no_socketpair,
880 .accept = sock_no_accept,
881 .getname = inet_getname,
882 .poll = datagram_poll,
884 .listen = sock_no_listen,
885 .shutdown = inet_shutdown,
886 .setsockopt = sock_common_setsockopt,
887 .getsockopt = sock_common_getsockopt,
888 .sendmsg = inet_sendmsg,
889 .recvmsg = sock_common_recvmsg,
890 .mmap = sock_no_mmap,
891 .sendpage = inet_sendpage,
893 .compat_setsockopt = compat_sock_common_setsockopt,
894 .compat_getsockopt = compat_sock_common_getsockopt,
898 static struct net_proto_family inet_family_ops = {
900 .create = inet_create,
901 .owner = THIS_MODULE,
904 /* Upon startup we insert all the elements in inetsw_array[] into
905 * the linked list inetsw.
907 static struct inet_protosw inetsw_array[] =
911 .protocol = IPPROTO_TCP,
913 .ops = &inet_stream_ops,
916 .flags = INET_PROTOSW_PERMANENT |
922 .protocol = IPPROTO_UDP,
924 .ops = &inet_dgram_ops,
926 .no_check = UDP_CSUM_DEFAULT,
927 .flags = INET_PROTOSW_PERMANENT,
933 .protocol = IPPROTO_IP, /* wild card */
935 .ops = &inet_sockraw_ops,
936 .capability = CAP_NET_RAW,
937 .no_check = UDP_CSUM_DEFAULT,
938 .flags = INET_PROTOSW_REUSE,
942 #define INETSW_ARRAY_LEN (sizeof(inetsw_array) / sizeof(struct inet_protosw))
944 void inet_register_protosw(struct inet_protosw *p)
946 struct list_head *lh;
947 struct inet_protosw *answer;
948 int protocol = p->protocol;
949 struct list_head *last_perm;
951 spin_lock_bh(&inetsw_lock);
953 if (p->type >= SOCK_MAX)
956 /* If we are trying to override a permanent protocol, bail. */
958 last_perm = &inetsw[p->type];
959 list_for_each(lh, &inetsw[p->type]) {
960 answer = list_entry(lh, struct inet_protosw, list);
962 /* Check only the non-wild match. */
963 if (INET_PROTOSW_PERMANENT & answer->flags) {
964 if (protocol == answer->protocol)
974 /* Add the new entry after the last permanent entry if any, so that
975 * the new entry does not override a permanent entry when matched with
976 * a wild-card protocol. But it is allowed to override any existing
977 * non-permanent entry. This means that when we remove this entry, the
978 * system automatically returns to the old behavior.
980 list_add_rcu(&p->list, last_perm);
982 spin_unlock_bh(&inetsw_lock);
989 printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
995 "Ignoring attempt to register invalid socket type %d.\n",
1000 void inet_unregister_protosw(struct inet_protosw *p)
1002 if (INET_PROTOSW_PERMANENT & p->flags) {
1004 "Attempt to unregister permanent protocol %d.\n",
1007 spin_lock_bh(&inetsw_lock);
1008 list_del_rcu(&p->list);
1009 spin_unlock_bh(&inetsw_lock);
1016 * Shall we try to damage output packets if routing dev changes?
1019 int sysctl_ip_dynaddr __read_mostly;
1021 static int inet_sk_reselect_saddr(struct sock *sk)
1023 struct inet_sock *inet = inet_sk(sk);
1026 __be32 old_saddr = inet->saddr;
1028 __be32 daddr = inet->daddr;
1030 if (inet->opt && inet->opt->srr)
1031 daddr = inet->opt->faddr;
1033 /* Query new route. */
1034 err = ip_route_connect(&rt, daddr, 0,
1036 sk->sk_bound_dev_if,
1038 inet->sport, inet->dport, sk, 0);
1042 sk_setup_caps(sk, &rt->u.dst);
1044 new_saddr = rt->rt_src;
1046 if (new_saddr == old_saddr)
1049 if (sysctl_ip_dynaddr > 1) {
1050 printk(KERN_INFO "%s(): shifting inet->"
1051 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
1054 NIPQUAD(new_saddr));
1057 inet->saddr = inet->rcv_saddr = new_saddr;
1060 * XXX The only one ugly spot where we need to
1061 * XXX really change the sockets identity after
1062 * XXX it has entered the hashes. -DaveM
1064 * Besides that, it does not check for connection
1065 * uniqueness. Wait for troubles.
1067 __sk_prot_rehash(sk);
1071 int inet_sk_rebuild_header(struct sock *sk)
1073 struct inet_sock *inet = inet_sk(sk);
1074 struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1078 /* Route is OK, nothing to do. */
1083 daddr = inet->daddr;
1084 if (inet->opt && inet->opt->srr)
1085 daddr = inet->opt->faddr;
1088 .oif = sk->sk_bound_dev_if,
1092 .saddr = inet->saddr,
1093 .tos = RT_CONN_FLAGS(sk),
1096 .proto = sk->sk_protocol,
1099 .sport = inet->sport,
1100 .dport = inet->dport,
1105 security_sk_classify_flow(sk, &fl);
1106 err = ip_route_output_flow(&rt, &fl, sk, 0);
1109 sk_setup_caps(sk, &rt->u.dst);
1111 /* Routing failed... */
1112 sk->sk_route_caps = 0;
1114 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1115 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1117 if (!sysctl_ip_dynaddr ||
1118 sk->sk_state != TCP_SYN_SENT ||
1119 (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1120 (err = inet_sk_reselect_saddr(sk)) != 0)
1121 sk->sk_err_soft = -err;
1127 EXPORT_SYMBOL(inet_sk_rebuild_header);
1129 static int inet_gso_send_check(struct sk_buff *skb)
1132 struct net_protocol *ops;
1137 if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1142 if (ihl < sizeof(*iph))
1145 if (unlikely(!pskb_may_pull(skb, ihl)))
1148 __skb_pull(skb, ihl);
1149 skb_reset_transport_header(skb);
1151 proto = iph->protocol & (MAX_INET_PROTOS - 1);
1152 err = -EPROTONOSUPPORT;
1155 ops = rcu_dereference(inet_protos[proto]);
1156 if (likely(ops && ops->gso_send_check))
1157 err = ops->gso_send_check(skb);
1164 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1166 struct sk_buff *segs = ERR_PTR(-EINVAL);
1168 struct net_protocol *ops;
1173 if (!(features & NETIF_F_V4_CSUM))
1174 features &= ~NETIF_F_SG;
1176 if (unlikely(skb_shinfo(skb)->gso_type &
1184 if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1189 if (ihl < sizeof(*iph))
1192 if (unlikely(!pskb_may_pull(skb, ihl)))
1195 __skb_pull(skb, ihl);
1196 skb_reset_transport_header(skb);
1198 id = ntohs(iph->id);
1199 proto = iph->protocol & (MAX_INET_PROTOS - 1);
1200 segs = ERR_PTR(-EPROTONOSUPPORT);
1203 ops = rcu_dereference(inet_protos[proto]);
1204 if (likely(ops && ops->gso_segment))
1205 segs = ops->gso_segment(skb, features);
1208 if (!segs || unlikely(IS_ERR(segs)))
1214 iph->id = htons(id++);
1215 iph->tot_len = htons(skb->len - skb->mac_len);
1217 iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1218 } while ((skb = skb->next));
1224 unsigned long snmp_fold_field(void *mib[], int offt)
1226 unsigned long res = 0;
1229 for_each_possible_cpu(i) {
1230 res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1231 res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1235 EXPORT_SYMBOL_GPL(snmp_fold_field);
1237 int snmp_mib_init(void *ptr[2], size_t mibsize, size_t mibalign)
1239 BUG_ON(ptr == NULL);
1240 ptr[0] = __alloc_percpu(mibsize);
1243 ptr[1] = __alloc_percpu(mibsize);
1248 free_percpu(ptr[0]);
1253 EXPORT_SYMBOL_GPL(snmp_mib_init);
1255 void snmp_mib_free(void *ptr[2])
1257 BUG_ON(ptr == NULL);
1258 free_percpu(ptr[0]);
1259 free_percpu(ptr[1]);
1260 ptr[0] = ptr[1] = NULL;
1262 EXPORT_SYMBOL_GPL(snmp_mib_free);
1264 #ifdef CONFIG_IP_MULTICAST
1265 static struct net_protocol igmp_protocol = {
1266 .handler = igmp_rcv,
1270 static struct net_protocol tcp_protocol = {
1271 .handler = tcp_v4_rcv,
1272 .err_handler = tcp_v4_err,
1273 .gso_send_check = tcp_v4_gso_send_check,
1274 .gso_segment = tcp_tso_segment,
1278 static struct net_protocol udp_protocol = {
1280 .err_handler = udp_err,
1284 static struct net_protocol icmp_protocol = {
1285 .handler = icmp_rcv,
1288 static int __init init_ipv4_mibs(void)
1290 if (snmp_mib_init((void **)net_statistics,
1291 sizeof(struct linux_mib),
1292 __alignof__(struct linux_mib)) < 0)
1294 if (snmp_mib_init((void **)ip_statistics,
1295 sizeof(struct ipstats_mib),
1296 __alignof__(struct ipstats_mib)) < 0)
1298 if (snmp_mib_init((void **)icmp_statistics,
1299 sizeof(struct icmp_mib),
1300 __alignof__(struct icmp_mib)) < 0)
1302 if (snmp_mib_init((void **)tcp_statistics,
1303 sizeof(struct tcp_mib),
1304 __alignof__(struct tcp_mib)) < 0)
1306 if (snmp_mib_init((void **)udp_statistics,
1307 sizeof(struct udp_mib),
1308 __alignof__(struct udp_mib)) < 0)
1310 if (snmp_mib_init((void **)udplite_statistics,
1311 sizeof(struct udp_mib),
1312 __alignof__(struct udp_mib)) < 0)
1313 goto err_udplite_mib;
1320 snmp_mib_free((void **)udp_statistics);
1322 snmp_mib_free((void **)tcp_statistics);
1324 snmp_mib_free((void **)icmp_statistics);
1326 snmp_mib_free((void **)ip_statistics);
1328 snmp_mib_free((void **)net_statistics);
1333 static int ipv4_proc_init(void);
1336 * IP protocol layer initialiser
1339 static struct packet_type ip_packet_type = {
1340 .type = __constant_htons(ETH_P_IP),
1342 .gso_send_check = inet_gso_send_check,
1343 .gso_segment = inet_gso_segment,
1346 static int __init inet_init(void)
1348 struct sk_buff *dummy_skb;
1349 struct inet_protosw *q;
1350 struct list_head *r;
1353 BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1355 rc = proto_register(&tcp_prot, 1);
1359 rc = proto_register(&udp_prot, 1);
1361 goto out_unregister_tcp_proto;
1363 rc = proto_register(&raw_prot, 1);
1365 goto out_unregister_udp_proto;
1368 * Tell SOCKET that we are alive...
1371 (void)sock_register(&inet_family_ops);
1374 * Add all the base protocols.
1377 if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1378 printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1379 if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1380 printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1381 if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1382 printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1383 #ifdef CONFIG_IP_MULTICAST
1384 if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1385 printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1388 /* Register the socket-side information for inet_create. */
1389 for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1392 for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1393 inet_register_protosw(q);
1396 * Set the ARP module up
1402 * Set the IP module up
1407 tcp_v4_init(&inet_family_ops);
1409 /* Setup TCP slab cache for open requests. */
1412 /* Add UDP-Lite (RFC 3828) */
1413 udplite4_register();
1416 * Set the ICMP layer up
1419 icmp_init(&inet_family_ops);
1422 * Initialise the multicast router
1424 #if defined(CONFIG_IP_MROUTE)
1428 * Initialise per-cpu ipv4 mibs
1431 if (init_ipv4_mibs())
1432 printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ;
1438 dev_add_pack(&ip_packet_type);
1443 out_unregister_udp_proto:
1444 proto_unregister(&udp_prot);
1445 out_unregister_tcp_proto:
1446 proto_unregister(&tcp_prot);
1450 fs_initcall(inet_init);
1452 /* ------------------------------------------------------------------------ */
1454 #ifdef CONFIG_PROC_FS
1455 static int __init ipv4_proc_init(void)
1459 if (raw_proc_init())
1461 if (tcp4_proc_init())
1463 if (udp4_proc_init())
1465 if (fib_proc_init())
1467 if (ip_misc_proc_init())
1484 #else /* CONFIG_PROC_FS */
1485 static int __init ipv4_proc_init(void)
1489 #endif /* CONFIG_PROC_FS */
1491 MODULE_ALIAS_NETPROTO(PF_INET);
1493 EXPORT_SYMBOL(inet_accept);
1494 EXPORT_SYMBOL(inet_bind);
1495 EXPORT_SYMBOL(inet_dgram_connect);
1496 EXPORT_SYMBOL(inet_dgram_ops);
1497 EXPORT_SYMBOL(inet_getname);
1498 EXPORT_SYMBOL(inet_ioctl);
1499 EXPORT_SYMBOL(inet_listen);
1500 EXPORT_SYMBOL(inet_register_protosw);
1501 EXPORT_SYMBOL(inet_release);
1502 EXPORT_SYMBOL(inet_sendmsg);
1503 EXPORT_SYMBOL(inet_shutdown);
1504 EXPORT_SYMBOL(inet_sock_destruct);
1505 EXPORT_SYMBOL(inet_stream_connect);
1506 EXPORT_SYMBOL(inet_stream_ops);
1507 EXPORT_SYMBOL(inet_unregister_protosw);
1508 EXPORT_SYMBOL(net_statistics);
1509 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);