1/*
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.
5 *
6 *		PF_INET protocol family socket handler.
7 *
8 * Authors:	Ross Biro
9 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 *		Florian La Roche, <flla@stud.uni-sb.de>
11 *		Alan Cox, <A.Cox@swansea.ac.uk>
12 *
13 * Changes (see also sock.c)
14 *
15 *		piggy,
16 *		Karl Knutson	:	Socket protocol table
17 *		A.N.Kuznetsov	:	Socket death error in accept().
18 *		John Richardson :	Fix non blocking error in connect()
19 *					so sockets that fail to connect
20 *					don't return -EINPROGRESS.
21 *		Alan Cox	:	Asynchronous I/O support
22 *		Alan Cox	:	Keep correct socket pointer on sock
23 *					structures
24 *					when accept() ed
25 *		Alan Cox	:	Semantics of SO_LINGER aren't state
26 *					moved to close when you look carefully.
27 *					With this fixed and the accept bug fixed
28 *					some RPC stuff seems happier.
29 *		Niibe Yutaka	:	4.4BSD style write async I/O
30 *		Alan Cox,
31 *		Tony Gale 	:	Fixed reuse semantics.
32 *		Alan Cox	:	bind() shouldn't abort existing but dead
33 *					sockets. Stops FTP netin:.. I hope.
34 *		Alan Cox	:	bind() works correctly for RAW sockets.
35 *					Note that FreeBSD at least was broken
36 *					in this respect so be careful with
37 *					compatibility tests...
38 *		Alan Cox	:	routing cache support
39 *		Alan Cox	:	memzero the socket structure for
40 *					compactness.
41 *		Matt Day	:	nonblock connect error handler
42 *		Alan Cox	:	Allow large numbers of pending sockets
43 *					(eg for big web sites), but only if
44 *					specifically application requested.
45 *		Alan Cox	:	New buffering throughout IP. Used
46 *					dumbly.
47 *		Alan Cox	:	New buffering now used smartly.
48 *		Alan Cox	:	BSD rather than common sense
49 *					interpretation of listen.
50 *		Germano Caronni	:	Assorted small races.
51 *		Alan Cox	:	sendmsg/recvmsg basic support.
52 *		Alan Cox	:	Only sendmsg/recvmsg now supported.
53 *		Alan Cox	:	Locked down bind (see security list).
54 *		Alan Cox	:	Loosened bind a little.
55 *		Mike McLagan	:	ADD/DEL DLCI Ioctls
56 *	Willy Konynenberg	:	Transparent proxying support.
57 *		David S. Miller	:	New socket lookup architecture.
58 *					Some other random speedups.
59 *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
60 *		Andi Kleen	:	Fix inet_stream_connect TCP race.
61 *
62 *		This program is free software; you can redistribute it and/or
63 *		modify it under the terms of the GNU General Public License
64 *		as published by the Free Software Foundation; either version
65 *		2 of the License, or (at your option) any later version.
66 */
67
68#define pr_fmt(fmt) "IPv4: " fmt
69
70#include <linux/err.h>
71#include <linux/errno.h>
72#include <linux/types.h>
73#include <linux/socket.h>
74#include <linux/in.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>
84#include <linux/mm.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>
91#include <linux/slab.h>
92
93#include <asm/uaccess.h>
94
95#include <linux/inet.h>
96#include <linux/igmp.h>
97#include <linux/inetdevice.h>
98#include <linux/netdevice.h>
99#include <net/checksum.h>
100#include <net/ip.h>
101#include <net/protocol.h>
102#include <net/arp.h>
103#include <net/route.h>
104#include <net/ip_fib.h>
105#include <net/inet_connection_sock.h>
106#include <net/tcp.h>
107#include <net/udp.h>
108#include <net/udplite.h>
109#include <net/ping.h>
110#include <linux/skbuff.h>
111#include <net/sock.h>
112#include <net/raw.h>
113#include <net/icmp.h>
114#include <net/inet_common.h>
115#include <net/xfrm.h>
116#include <net/net_namespace.h>
117#include <net/secure_seq.h>
118#ifdef CONFIG_IP_MROUTE
119#include <linux/mroute.h>
120#endif
121
122#ifdef CONFIG_ANDROID_PARANOID_NETWORK
123#include <linux/android_aid.h>
124
125static inline int current_has_network(void)
126{
127	return in_egroup_p(AID_INET) || capable(CAP_NET_RAW);
128}
129#else
130static inline int current_has_network(void)
131{
132	return 1;
133}
134#endif
135
136/* The inetsw table contains everything that inet_create needs to
137 * build a new socket.
138 */
139static struct list_head inetsw[SOCK_MAX];
140static DEFINE_SPINLOCK(inetsw_lock);
141
142/* New destruction routine */
143
144void inet_sock_destruct(struct sock *sk)
145{
146	struct inet_sock *inet = inet_sk(sk);
147
148	__skb_queue_purge(&sk->sk_receive_queue);
149	__skb_queue_purge(&sk->sk_error_queue);
150
151	sk_mem_reclaim(sk);
152
153	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
154		pr_err("Attempt to release TCP socket in state %d %p\n",
155		       sk->sk_state, sk);
156		return;
157	}
158	if (!sock_flag(sk, SOCK_DEAD)) {
159		pr_err("Attempt to release alive inet socket %p\n", sk);
160		return;
161	}
162
163	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
164	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
165	WARN_ON(sk->sk_wmem_queued);
166	WARN_ON(sk->sk_forward_alloc);
167
168	kfree(rcu_dereference_protected(inet->inet_opt, 1));
169	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
170	dst_release(sk->sk_rx_dst);
171	sk_refcnt_debug_dec(sk);
172}
173EXPORT_SYMBOL(inet_sock_destruct);
174
175/*
176 *	The routines beyond this point handle the behaviour of an AF_INET
177 *	socket object. Mostly it punts to the subprotocols of IP to do
178 *	the work.
179 */
180
181/*
182 *	Automatically bind an unbound socket.
183 */
184
185static int inet_autobind(struct sock *sk)
186{
187	struct inet_sock *inet;
188	/* We may need to bind the socket. */
189	lock_sock(sk);
190	inet = inet_sk(sk);
191	if (!inet->inet_num) {
192		if (sk->sk_prot->get_port(sk, 0)) {
193			release_sock(sk);
194			return -EAGAIN;
195		}
196		inet->inet_sport = htons(inet->inet_num);
197	}
198	release_sock(sk);
199	return 0;
200}
201
202/*
203 *	Move a socket into listening state.
204 */
205int inet_listen(struct socket *sock, int backlog)
206{
207	struct sock *sk = sock->sk;
208	unsigned char old_state;
209	int err;
210
211	lock_sock(sk);
212
213	err = -EINVAL;
214	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
215		goto out;
216
217	old_state = sk->sk_state;
218	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
219		goto out;
220
221	/* Really, if the socket is already in listen state
222	 * we can only allow the backlog to be adjusted.
223	 */
224	if (old_state != TCP_LISTEN) {
225		/* Check special setups for testing purpose to enable TFO w/o
226		 * requiring TCP_FASTOPEN sockopt.
227		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
228		 * Also fastopenq may already been allocated because this
229		 * socket was in TCP_LISTEN state previously but was
230		 * shutdown() (rather than close()).
231		 */
232		if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
233		    inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
234			if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
235				err = fastopen_init_queue(sk, backlog);
236			else if ((sysctl_tcp_fastopen &
237				  TFO_SERVER_WO_SOCKOPT2) != 0)
238				err = fastopen_init_queue(sk,
239				    ((uint)sysctl_tcp_fastopen) >> 16);
240			else
241				err = 0;
242			if (err)
243				goto out;
244		}
245		err = inet_csk_listen_start(sk, backlog);
246		if (err)
247			goto out;
248	}
249	sk->sk_max_ack_backlog = backlog;
250	err = 0;
251
252out:
253	release_sock(sk);
254	return err;
255}
256EXPORT_SYMBOL(inet_listen);
257
258/*
259 *	Create an inet socket.
260 */
261
262static int inet_create(struct net *net, struct socket *sock, int protocol,
263		       int kern)
264{
265	struct sock *sk;
266	struct inet_protosw *answer;
267	struct inet_sock *inet;
268	struct proto *answer_prot;
269	unsigned char answer_flags;
270	int try_loading_module = 0;
271	int err;
272
273	if (!current_has_network())
274		return -EACCES;
275
276	sock->state = SS_UNCONNECTED;
277
278	/* Look for the requested type/protocol pair. */
279lookup_protocol:
280	err = -ESOCKTNOSUPPORT;
281	rcu_read_lock();
282	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
283
284		err = 0;
285		/* Check the non-wild match. */
286		if (protocol == answer->protocol) {
287			if (protocol != IPPROTO_IP)
288				break;
289		} else {
290			/* Check for the two wild cases. */
291			if (IPPROTO_IP == protocol) {
292				protocol = answer->protocol;
293				break;
294			}
295			if (IPPROTO_IP == answer->protocol)
296				break;
297		}
298		err = -EPROTONOSUPPORT;
299	}
300
301	if (unlikely(err)) {
302		if (try_loading_module < 2) {
303			rcu_read_unlock();
304			/*
305			 * Be more specific, e.g. net-pf-2-proto-132-type-1
306			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
307			 */
308			if (++try_loading_module == 1)
309				request_module("net-pf-%d-proto-%d-type-%d",
310					       PF_INET, protocol, sock->type);
311			/*
312			 * Fall back to generic, e.g. net-pf-2-proto-132
313			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
314			 */
315			else
316				request_module("net-pf-%d-proto-%d",
317					       PF_INET, protocol);
318			goto lookup_protocol;
319		} else
320			goto out_rcu_unlock;
321	}
322
323	err = -EPERM;
324	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
325		goto out_rcu_unlock;
326
327	sock->ops = answer->ops;
328	answer_prot = answer->prot;
329	answer_flags = answer->flags;
330	rcu_read_unlock();
331
332	WARN_ON(answer_prot->slab == NULL);
333
334	err = -ENOBUFS;
335	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
336	if (sk == NULL)
337		goto out;
338
339	err = 0;
340	if (INET_PROTOSW_REUSE & answer_flags)
341		sk->sk_reuse = SK_CAN_REUSE;
342
343	inet = inet_sk(sk);
344	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
345
346	inet->nodefrag = 0;
347
348	if (SOCK_RAW == sock->type) {
349		inet->inet_num = protocol;
350		if (IPPROTO_RAW == protocol)
351			inet->hdrincl = 1;
352	}
353
354	if (net->ipv4.sysctl_ip_no_pmtu_disc)
355		inet->pmtudisc = IP_PMTUDISC_DONT;
356	else
357		inet->pmtudisc = IP_PMTUDISC_WANT;
358
359	inet->inet_id = 0;
360
361	sock_init_data(sock, sk);
362
363	sk->sk_destruct	   = inet_sock_destruct;
364	sk->sk_protocol	   = protocol;
365	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
366
367	inet->uc_ttl	= -1;
368	inet->mc_loop	= 1;
369	inet->mc_ttl	= 1;
370	inet->mc_all	= 1;
371	inet->mc_index	= 0;
372	inet->mc_list	= NULL;
373	inet->rcv_tos	= 0;
374
375	sk_refcnt_debug_inc(sk);
376
377	if (inet->inet_num) {
378		/* It assumes that any protocol which allows
379		 * the user to assign a number at socket
380		 * creation time automatically
381		 * shares.
382		 */
383		inet->inet_sport = htons(inet->inet_num);
384		/* Add to protocol hash chains. */
385		sk->sk_prot->hash(sk);
386	}
387
388	if (sk->sk_prot->init) {
389		err = sk->sk_prot->init(sk);
390		if (err)
391			sk_common_release(sk);
392	}
393out:
394	return err;
395out_rcu_unlock:
396	rcu_read_unlock();
397	goto out;
398}
399
400
401/*
402 *	The peer socket should always be NULL (or else). When we call this
403 *	function we are destroying the object and from then on nobody
404 *	should refer to it.
405 */
406int inet_release(struct socket *sock)
407{
408	struct sock *sk = sock->sk;
409
410	if (sk) {
411		long timeout;
412
413		sock_rps_reset_flow(sk);
414
415		/* Applications forget to leave groups before exiting */
416		ip_mc_drop_socket(sk);
417
418		/* If linger is set, we don't return until the close
419		 * is complete.  Otherwise we return immediately. The
420		 * actually closing is done the same either way.
421		 *
422		 * If the close is due to the process exiting, we never
423		 * linger..
424		 */
425		timeout = 0;
426		if (sock_flag(sk, SOCK_LINGER) &&
427		    !(current->flags & PF_EXITING))
428			timeout = sk->sk_lingertime;
429		sock->sk = NULL;
430		sk->sk_prot->close(sk, timeout);
431	}
432	return 0;
433}
434EXPORT_SYMBOL(inet_release);
435
436int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
437{
438	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
439	struct sock *sk = sock->sk;
440	struct inet_sock *inet = inet_sk(sk);
441	struct net *net = sock_net(sk);
442	unsigned short snum;
443	int chk_addr_ret;
444	int err;
445
446	/* If the socket has its own bind function then use it. (RAW) */
447	if (sk->sk_prot->bind) {
448		err = sk->sk_prot->bind(sk, uaddr, addr_len);
449		goto out;
450	}
451	err = -EINVAL;
452	if (addr_len < sizeof(struct sockaddr_in))
453		goto out;
454
455	if (addr->sin_family != AF_INET) {
456		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
457		 * only if s_addr is INADDR_ANY.
458		 */
459		err = -EAFNOSUPPORT;
460		if (addr->sin_family != AF_UNSPEC ||
461		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
462			goto out;
463	}
464
465	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
466
467	/* Not specified by any standard per-se, however it breaks too
468	 * many applications when removed.  It is unfortunate since
469	 * allowing applications to make a non-local bind solves
470	 * several problems with systems using dynamic addressing.
471	 * (ie. your servers still start up even if your ISDN link
472	 *  is temporarily down)
473	 */
474	err = -EADDRNOTAVAIL;
475	if (!net->ipv4.sysctl_ip_nonlocal_bind &&
476	    !(inet->freebind || inet->transparent) &&
477	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
478	    chk_addr_ret != RTN_LOCAL &&
479	    chk_addr_ret != RTN_MULTICAST &&
480	    chk_addr_ret != RTN_BROADCAST)
481		goto out;
482
483	snum = ntohs(addr->sin_port);
484	err = -EACCES;
485	if (snum && snum < PROT_SOCK &&
486	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
487		goto out;
488
489	/*      We keep a pair of addresses. rcv_saddr is the one
490	 *      used by hash lookups, and saddr is used for transmit.
491	 *
492	 *      In the BSD API these are the same except where it
493	 *      would be illegal to use them (multicast/broadcast) in
494	 *      which case the sending device address is used.
495	 */
496	lock_sock(sk);
497
498	/* Check these errors (active socket, double bind). */
499	err = -EINVAL;
500	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
501		goto out_release_sock;
502
503	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
504	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
505		inet->inet_saddr = 0;  /* Use device */
506
507	/* Make sure we are allowed to bind here. */
508	if (sk->sk_prot->get_port(sk, snum)) {
509		inet->inet_saddr = inet->inet_rcv_saddr = 0;
510		err = -EADDRINUSE;
511		goto out_release_sock;
512	}
513
514	if (inet->inet_rcv_saddr)
515		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
516	if (snum)
517		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
518	inet->inet_sport = htons(inet->inet_num);
519	inet->inet_daddr = 0;
520	inet->inet_dport = 0;
521	sk_dst_reset(sk);
522	err = 0;
523out_release_sock:
524	release_sock(sk);
525out:
526	return err;
527}
528EXPORT_SYMBOL(inet_bind);
529
530int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
531		       int addr_len, int flags)
532{
533	struct sock *sk = sock->sk;
534
535	if (addr_len < sizeof(uaddr->sa_family))
536		return -EINVAL;
537	if (uaddr->sa_family == AF_UNSPEC)
538		return sk->sk_prot->disconnect(sk, flags);
539
540	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
541		return -EAGAIN;
542	return sk->sk_prot->connect(sk, uaddr, addr_len);
543}
544EXPORT_SYMBOL(inet_dgram_connect);
545
546static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
547{
548	DEFINE_WAIT(wait);
549
550	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
551	sk->sk_write_pending += writebias;
552
553	/* Basic assumption: if someone sets sk->sk_err, he _must_
554	 * change state of the socket from TCP_SYN_*.
555	 * Connect() does not allow to get error notifications
556	 * without closing the socket.
557	 */
558	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
559		release_sock(sk);
560		timeo = schedule_timeout(timeo);
561		lock_sock(sk);
562		if (signal_pending(current) || !timeo)
563			break;
564		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
565	}
566	finish_wait(sk_sleep(sk), &wait);
567	sk->sk_write_pending -= writebias;
568	return timeo;
569}
570
571/*
572 *	Connect to a remote host. There is regrettably still a little
573 *	TCP 'magic' in here.
574 */
575int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
576			  int addr_len, int flags)
577{
578	struct sock *sk = sock->sk;
579	int err;
580	long timeo;
581
582	if (addr_len < sizeof(uaddr->sa_family))
583		return -EINVAL;
584
585	if (uaddr->sa_family == AF_UNSPEC) {
586		err = sk->sk_prot->disconnect(sk, flags);
587		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
588		goto out;
589	}
590
591	switch (sock->state) {
592	default:
593		err = -EINVAL;
594		goto out;
595	case SS_CONNECTED:
596		err = -EISCONN;
597		goto out;
598	case SS_CONNECTING:
599		err = -EALREADY;
600		/* Fall out of switch with err, set for this state */
601		break;
602	case SS_UNCONNECTED:
603		err = -EISCONN;
604		if (sk->sk_state != TCP_CLOSE)
605			goto out;
606
607		err = sk->sk_prot->connect(sk, uaddr, addr_len);
608		if (err < 0)
609			goto out;
610
611		sock->state = SS_CONNECTING;
612
613		/* Just entered SS_CONNECTING state; the only
614		 * difference is that return value in non-blocking
615		 * case is EINPROGRESS, rather than EALREADY.
616		 */
617		err = -EINPROGRESS;
618		break;
619	}
620
621	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
622
623	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
624		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
625				tcp_sk(sk)->fastopen_req &&
626				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
627
628		/* Error code is set above */
629		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
630			goto out;
631
632		err = sock_intr_errno(timeo);
633		if (signal_pending(current))
634			goto out;
635	}
636
637	/* Connection was closed by RST, timeout, ICMP error
638	 * or another process disconnected us.
639	 */
640	if (sk->sk_state == TCP_CLOSE)
641		goto sock_error;
642
643	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
644	 * and error was received after socket entered established state.
645	 * Hence, it is handled normally after connect() return successfully.
646	 */
647
648	sock->state = SS_CONNECTED;
649	err = 0;
650out:
651	return err;
652
653sock_error:
654	err = sock_error(sk) ? : -ECONNABORTED;
655	sock->state = SS_UNCONNECTED;
656	if (sk->sk_prot->disconnect(sk, flags))
657		sock->state = SS_DISCONNECTING;
658	goto out;
659}
660EXPORT_SYMBOL(__inet_stream_connect);
661
662int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
663			int addr_len, int flags)
664{
665	int err;
666
667	lock_sock(sock->sk);
668	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
669	release_sock(sock->sk);
670	return err;
671}
672EXPORT_SYMBOL(inet_stream_connect);
673
674/*
675 *	Accept a pending connection. The TCP layer now gives BSD semantics.
676 */
677
678int inet_accept(struct socket *sock, struct socket *newsock, int flags)
679{
680	struct sock *sk1 = sock->sk;
681	int err = -EINVAL;
682	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
683
684	if (!sk2)
685		goto do_err;
686
687	lock_sock(sk2);
688
689	sock_rps_record_flow(sk2);
690	WARN_ON(!((1 << sk2->sk_state) &
691		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
692		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
693
694	sock_graft(sk2, newsock);
695
696	newsock->state = SS_CONNECTED;
697	err = 0;
698	release_sock(sk2);
699do_err:
700	return err;
701}
702EXPORT_SYMBOL(inet_accept);
703
704
705/*
706 *	This does both peername and sockname.
707 */
708int inet_getname(struct socket *sock, struct sockaddr *uaddr,
709			int *uaddr_len, int peer)
710{
711	struct sock *sk		= sock->sk;
712	struct inet_sock *inet	= inet_sk(sk);
713	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
714
715	sin->sin_family = AF_INET;
716	if (peer) {
717		if (!inet->inet_dport ||
718		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
719		     peer == 1))
720			return -ENOTCONN;
721		sin->sin_port = inet->inet_dport;
722		sin->sin_addr.s_addr = inet->inet_daddr;
723	} else {
724		__be32 addr = inet->inet_rcv_saddr;
725		if (!addr)
726			addr = inet->inet_saddr;
727		sin->sin_port = inet->inet_sport;
728		sin->sin_addr.s_addr = addr;
729	}
730	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
731	*uaddr_len = sizeof(*sin);
732	return 0;
733}
734EXPORT_SYMBOL(inet_getname);
735
736int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
737		 size_t size)
738{
739	struct sock *sk = sock->sk;
740
741	sock_rps_record_flow(sk);
742
743	/* We may need to bind the socket. */
744	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
745	    inet_autobind(sk))
746		return -EAGAIN;
747
748	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
749}
750EXPORT_SYMBOL(inet_sendmsg);
751
752ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
753		      size_t size, int flags)
754{
755	struct sock *sk = sock->sk;
756
757	sock_rps_record_flow(sk);
758
759	/* We may need to bind the socket. */
760	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
761	    inet_autobind(sk))
762		return -EAGAIN;
763
764	if (sk->sk_prot->sendpage)
765		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
766	return sock_no_sendpage(sock, page, offset, size, flags);
767}
768EXPORT_SYMBOL(inet_sendpage);
769
770int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
771		 size_t size, int flags)
772{
773	struct sock *sk = sock->sk;
774	int addr_len = 0;
775	int err;
776
777	sock_rps_record_flow(sk);
778
779	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
780				   flags & ~MSG_DONTWAIT, &addr_len);
781	if (err >= 0)
782		msg->msg_namelen = addr_len;
783	return err;
784}
785EXPORT_SYMBOL(inet_recvmsg);
786
787int inet_shutdown(struct socket *sock, int how)
788{
789	struct sock *sk = sock->sk;
790	int err = 0;
791
792	/* This should really check to make sure
793	 * the socket is a TCP socket. (WHY AC...)
794	 */
795	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
796		       1->2 bit 2 snds.
797		       2->3 */
798	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
799		return -EINVAL;
800
801	lock_sock(sk);
802	if (sock->state == SS_CONNECTING) {
803		if ((1 << sk->sk_state) &
804		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
805			sock->state = SS_DISCONNECTING;
806		else
807			sock->state = SS_CONNECTED;
808	}
809
810	switch (sk->sk_state) {
811	case TCP_CLOSE:
812		err = -ENOTCONN;
813		/* Hack to wake up other listeners, who can poll for
814		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
815	default:
816		sk->sk_shutdown |= how;
817		if (sk->sk_prot->shutdown)
818			sk->sk_prot->shutdown(sk, how);
819		break;
820
821	/* Remaining two branches are temporary solution for missing
822	 * close() in multithreaded environment. It is _not_ a good idea,
823	 * but we have no choice until close() is repaired at VFS level.
824	 */
825	case TCP_LISTEN:
826		if (!(how & RCV_SHUTDOWN))
827			break;
828		/* Fall through */
829	case TCP_SYN_SENT:
830		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
831		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
832		break;
833	}
834
835	/* Wake up anyone sleeping in poll. */
836	sk->sk_state_change(sk);
837	release_sock(sk);
838	return err;
839}
840EXPORT_SYMBOL(inet_shutdown);
841
842/*
843 *	ioctl() calls you can issue on an INET socket. Most of these are
844 *	device configuration and stuff and very rarely used. Some ioctls
845 *	pass on to the socket itself.
846 *
847 *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
848 *	loads the devconfigure module does its configuring and unloads it.
849 *	There's a good 20K of config code hanging around the kernel.
850 */
851
852int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
853{
854	struct sock *sk = sock->sk;
855	int err = 0;
856	struct net *net = sock_net(sk);
857
858	switch (cmd) {
859	case SIOCGSTAMP:
860		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
861		break;
862	case SIOCGSTAMPNS:
863		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
864		break;
865	case SIOCADDRT:
866	case SIOCDELRT:
867	case SIOCRTMSG:
868		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
869		break;
870	case SIOCDARP:
871	case SIOCGARP:
872	case SIOCSARP:
873		err = arp_ioctl(net, cmd, (void __user *)arg);
874		break;
875	case SIOCGIFADDR:
876	case SIOCSIFADDR:
877	case SIOCGIFBRDADDR:
878	case SIOCSIFBRDADDR:
879	case SIOCGIFNETMASK:
880	case SIOCSIFNETMASK:
881	case SIOCGIFDSTADDR:
882	case SIOCSIFDSTADDR:
883	case SIOCSIFPFLAGS:
884	case SIOCGIFPFLAGS:
885	case SIOCSIFFLAGS:
886	case SIOCKILLADDR:
887		err = devinet_ioctl(net, cmd, (void __user *)arg);
888		break;
889	default:
890		if (sk->sk_prot->ioctl)
891			err = sk->sk_prot->ioctl(sk, cmd, arg);
892		else
893			err = -ENOIOCTLCMD;
894		break;
895	}
896	return err;
897}
898EXPORT_SYMBOL(inet_ioctl);
899
900#ifdef CONFIG_COMPAT
901static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
902{
903	struct sock *sk = sock->sk;
904	int err = -ENOIOCTLCMD;
905
906	if (sk->sk_prot->compat_ioctl)
907		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
908
909	return err;
910}
911#endif
912
913const struct proto_ops inet_stream_ops = {
914	.family		   = PF_INET,
915	.owner		   = THIS_MODULE,
916	.release	   = inet_release,
917	.bind		   = inet_bind,
918	.connect	   = inet_stream_connect,
919	.socketpair	   = sock_no_socketpair,
920	.accept		   = inet_accept,
921	.getname	   = inet_getname,
922	.poll		   = tcp_poll,
923	.ioctl		   = inet_ioctl,
924	.listen		   = inet_listen,
925	.shutdown	   = inet_shutdown,
926	.setsockopt	   = sock_common_setsockopt,
927	.getsockopt	   = sock_common_getsockopt,
928	.sendmsg	   = inet_sendmsg,
929	.recvmsg	   = inet_recvmsg,
930	.mmap		   = sock_no_mmap,
931	.sendpage	   = inet_sendpage,
932	.splice_read	   = tcp_splice_read,
933#ifdef CONFIG_COMPAT
934	.compat_setsockopt = compat_sock_common_setsockopt,
935	.compat_getsockopt = compat_sock_common_getsockopt,
936	.compat_ioctl	   = inet_compat_ioctl,
937#endif
938};
939EXPORT_SYMBOL(inet_stream_ops);
940
941const struct proto_ops inet_dgram_ops = {
942	.family		   = PF_INET,
943	.owner		   = THIS_MODULE,
944	.release	   = inet_release,
945	.bind		   = inet_bind,
946	.connect	   = inet_dgram_connect,
947	.socketpair	   = sock_no_socketpair,
948	.accept		   = sock_no_accept,
949	.getname	   = inet_getname,
950	.poll		   = udp_poll,
951	.ioctl		   = inet_ioctl,
952	.listen		   = sock_no_listen,
953	.shutdown	   = inet_shutdown,
954	.setsockopt	   = sock_common_setsockopt,
955	.getsockopt	   = sock_common_getsockopt,
956	.sendmsg	   = inet_sendmsg,
957	.recvmsg	   = inet_recvmsg,
958	.mmap		   = sock_no_mmap,
959	.sendpage	   = inet_sendpage,
960#ifdef CONFIG_COMPAT
961	.compat_setsockopt = compat_sock_common_setsockopt,
962	.compat_getsockopt = compat_sock_common_getsockopt,
963	.compat_ioctl	   = inet_compat_ioctl,
964#endif
965};
966EXPORT_SYMBOL(inet_dgram_ops);
967
968/*
969 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
970 * udp_poll
971 */
972static const struct proto_ops inet_sockraw_ops = {
973	.family		   = PF_INET,
974	.owner		   = THIS_MODULE,
975	.release	   = inet_release,
976	.bind		   = inet_bind,
977	.connect	   = inet_dgram_connect,
978	.socketpair	   = sock_no_socketpair,
979	.accept		   = sock_no_accept,
980	.getname	   = inet_getname,
981	.poll		   = datagram_poll,
982	.ioctl		   = inet_ioctl,
983	.listen		   = sock_no_listen,
984	.shutdown	   = inet_shutdown,
985	.setsockopt	   = sock_common_setsockopt,
986	.getsockopt	   = sock_common_getsockopt,
987	.sendmsg	   = inet_sendmsg,
988	.recvmsg	   = inet_recvmsg,
989	.mmap		   = sock_no_mmap,
990	.sendpage	   = inet_sendpage,
991#ifdef CONFIG_COMPAT
992	.compat_setsockopt = compat_sock_common_setsockopt,
993	.compat_getsockopt = compat_sock_common_getsockopt,
994	.compat_ioctl	   = inet_compat_ioctl,
995#endif
996};
997
998static const struct net_proto_family inet_family_ops = {
999	.family = PF_INET,
1000	.create = inet_create,
1001	.owner	= THIS_MODULE,
1002};
1003
1004/* Upon startup we insert all the elements in inetsw_array[] into
1005 * the linked list inetsw.
1006 */
1007static struct inet_protosw inetsw_array[] =
1008{
1009	{
1010		.type =       SOCK_STREAM,
1011		.protocol =   IPPROTO_TCP,
1012		.prot =       &tcp_prot,
1013		.ops =        &inet_stream_ops,
1014		.flags =      INET_PROTOSW_PERMANENT |
1015			      INET_PROTOSW_ICSK,
1016	},
1017
1018	{
1019		.type =       SOCK_DGRAM,
1020		.protocol =   IPPROTO_UDP,
1021		.prot =       &udp_prot,
1022		.ops =        &inet_dgram_ops,
1023		.flags =      INET_PROTOSW_PERMANENT,
1024       },
1025
1026       {
1027		.type =       SOCK_DGRAM,
1028		.protocol =   IPPROTO_ICMP,
1029		.prot =       &ping_prot,
1030		.ops =        &inet_dgram_ops,
1031		.flags =      INET_PROTOSW_REUSE,
1032       },
1033
1034       {
1035	       .type =       SOCK_RAW,
1036	       .protocol =   IPPROTO_IP,	/* wild card */
1037	       .prot =       &raw_prot,
1038	       .ops =        &inet_sockraw_ops,
1039	       .flags =      INET_PROTOSW_REUSE,
1040       }
1041};
1042
1043#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1044
1045void inet_register_protosw(struct inet_protosw *p)
1046{
1047	struct list_head *lh;
1048	struct inet_protosw *answer;
1049	int protocol = p->protocol;
1050	struct list_head *last_perm;
1051
1052	spin_lock_bh(&inetsw_lock);
1053
1054	if (p->type >= SOCK_MAX)
1055		goto out_illegal;
1056
1057	/* If we are trying to override a permanent protocol, bail. */
1058	answer = NULL;
1059	last_perm = &inetsw[p->type];
1060	list_for_each(lh, &inetsw[p->type]) {
1061		answer = list_entry(lh, struct inet_protosw, list);
1062
1063		/* Check only the non-wild match. */
1064		if (INET_PROTOSW_PERMANENT & answer->flags) {
1065			if (protocol == answer->protocol)
1066				break;
1067			last_perm = lh;
1068		}
1069
1070		answer = NULL;
1071	}
1072	if (answer)
1073		goto out_permanent;
1074
1075	/* Add the new entry after the last permanent entry if any, so that
1076	 * the new entry does not override a permanent entry when matched with
1077	 * a wild-card protocol. But it is allowed to override any existing
1078	 * non-permanent entry.  This means that when we remove this entry, the
1079	 * system automatically returns to the old behavior.
1080	 */
1081	list_add_rcu(&p->list, last_perm);
1082out:
1083	spin_unlock_bh(&inetsw_lock);
1084
1085	return;
1086
1087out_permanent:
1088	pr_err("Attempt to override permanent protocol %d\n", protocol);
1089	goto out;
1090
1091out_illegal:
1092	pr_err("Ignoring attempt to register invalid socket type %d\n",
1093	       p->type);
1094	goto out;
1095}
1096EXPORT_SYMBOL(inet_register_protosw);
1097
1098void inet_unregister_protosw(struct inet_protosw *p)
1099{
1100	if (INET_PROTOSW_PERMANENT & p->flags) {
1101		pr_err("Attempt to unregister permanent protocol %d\n",
1102		       p->protocol);
1103	} else {
1104		spin_lock_bh(&inetsw_lock);
1105		list_del_rcu(&p->list);
1106		spin_unlock_bh(&inetsw_lock);
1107
1108		synchronize_net();
1109	}
1110}
1111EXPORT_SYMBOL(inet_unregister_protosw);
1112
1113/*
1114 *      Shall we try to damage output packets if routing dev changes?
1115 */
1116
1117int sysctl_ip_dynaddr __read_mostly;
1118
1119static int inet_sk_reselect_saddr(struct sock *sk)
1120{
1121	struct inet_sock *inet = inet_sk(sk);
1122	__be32 old_saddr = inet->inet_saddr;
1123	__be32 daddr = inet->inet_daddr;
1124	struct flowi4 *fl4;
1125	struct rtable *rt;
1126	__be32 new_saddr;
1127	struct ip_options_rcu *inet_opt;
1128
1129	inet_opt = rcu_dereference_protected(inet->inet_opt,
1130					     sock_owned_by_user(sk));
1131	if (inet_opt && inet_opt->opt.srr)
1132		daddr = inet_opt->opt.faddr;
1133
1134	/* Query new route. */
1135	fl4 = &inet->cork.fl.u.ip4;
1136	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1137			      sk->sk_bound_dev_if, sk->sk_protocol,
1138			      inet->inet_sport, inet->inet_dport, sk);
1139	if (IS_ERR(rt))
1140		return PTR_ERR(rt);
1141
1142	sk_setup_caps(sk, &rt->dst);
1143
1144	new_saddr = fl4->saddr;
1145
1146	if (new_saddr == old_saddr)
1147		return 0;
1148
1149	if (sysctl_ip_dynaddr > 1) {
1150		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1151			__func__, &old_saddr, &new_saddr);
1152	}
1153
1154	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1155
1156	/*
1157	 * XXX The only one ugly spot where we need to
1158	 * XXX really change the sockets identity after
1159	 * XXX it has entered the hashes. -DaveM
1160	 *
1161	 * Besides that, it does not check for connection
1162	 * uniqueness. Wait for troubles.
1163	 */
1164	__sk_prot_rehash(sk);
1165	return 0;
1166}
1167
1168int inet_sk_rebuild_header(struct sock *sk)
1169{
1170	struct inet_sock *inet = inet_sk(sk);
1171	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1172	__be32 daddr;
1173	struct ip_options_rcu *inet_opt;
1174	struct flowi4 *fl4;
1175	int err;
1176
1177	/* Route is OK, nothing to do. */
1178	if (rt)
1179		return 0;
1180
1181	/* Reroute. */
1182	rcu_read_lock();
1183	inet_opt = rcu_dereference(inet->inet_opt);
1184	daddr = inet->inet_daddr;
1185	if (inet_opt && inet_opt->opt.srr)
1186		daddr = inet_opt->opt.faddr;
1187	rcu_read_unlock();
1188	fl4 = &inet->cork.fl.u.ip4;
1189	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1190				   inet->inet_dport, inet->inet_sport,
1191				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1192				   sk->sk_bound_dev_if);
1193	if (!IS_ERR(rt)) {
1194		err = 0;
1195		sk_setup_caps(sk, &rt->dst);
1196	} else {
1197		err = PTR_ERR(rt);
1198
1199		/* Routing failed... */
1200		sk->sk_route_caps = 0;
1201		/*
1202		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1203		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1204		 */
1205		if (!sysctl_ip_dynaddr ||
1206		    sk->sk_state != TCP_SYN_SENT ||
1207		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1208		    (err = inet_sk_reselect_saddr(sk)) != 0)
1209			sk->sk_err_soft = -err;
1210	}
1211
1212	return err;
1213}
1214EXPORT_SYMBOL(inet_sk_rebuild_header);
1215
1216static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1217					netdev_features_t features)
1218{
1219	struct sk_buff *segs = ERR_PTR(-EINVAL);
1220	const struct net_offload *ops;
1221	unsigned int offset = 0;
1222	bool udpfrag, encap;
1223	struct iphdr *iph;
1224	int proto;
1225	int nhoff;
1226	int ihl;
1227	int id;
1228
1229	if (unlikely(skb_shinfo(skb)->gso_type &
1230		     ~(SKB_GSO_TCPV4 |
1231		       SKB_GSO_UDP |
1232		       SKB_GSO_DODGY |
1233		       SKB_GSO_TCP_ECN |
1234		       SKB_GSO_GRE |
1235		       SKB_GSO_GRE_CSUM |
1236		       SKB_GSO_IPIP |
1237		       SKB_GSO_SIT |
1238		       SKB_GSO_TCPV6 |
1239		       SKB_GSO_UDP_TUNNEL |
1240		       SKB_GSO_UDP_TUNNEL_CSUM |
1241		       SKB_GSO_MPLS |
1242		       0)))
1243		goto out;
1244
1245	skb_reset_network_header(skb);
1246	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1247	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1248		goto out;
1249
1250	iph = ip_hdr(skb);
1251	ihl = iph->ihl * 4;
1252	if (ihl < sizeof(*iph))
1253		goto out;
1254
1255	id = ntohs(iph->id);
1256	proto = iph->protocol;
1257
1258	/* Warning: after this point, iph might be no longer valid */
1259	if (unlikely(!pskb_may_pull(skb, ihl)))
1260		goto out;
1261	__skb_pull(skb, ihl);
1262
1263	encap = SKB_GSO_CB(skb)->encap_level > 0;
1264	if (encap)
1265		features &= skb->dev->hw_enc_features;
1266	SKB_GSO_CB(skb)->encap_level += ihl;
1267
1268	skb_reset_transport_header(skb);
1269
1270	segs = ERR_PTR(-EPROTONOSUPPORT);
1271
1272	if (skb->encapsulation &&
1273	    skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
1274		udpfrag = proto == IPPROTO_UDP && encap;
1275	else
1276		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
1277
1278	ops = rcu_dereference(inet_offloads[proto]);
1279	if (likely(ops && ops->callbacks.gso_segment))
1280		segs = ops->callbacks.gso_segment(skb, features);
1281
1282	if (IS_ERR_OR_NULL(segs))
1283		goto out;
1284
1285	skb = segs;
1286	do {
1287		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1288		if (udpfrag) {
1289			iph->id = htons(id);
1290			iph->frag_off = htons(offset >> 3);
1291			if (skb->next != NULL)
1292				iph->frag_off |= htons(IP_MF);
1293			offset += skb->len - nhoff - ihl;
1294		} else {
1295			iph->id = htons(id++);
1296		}
1297		iph->tot_len = htons(skb->len - nhoff);
1298		ip_send_check(iph);
1299		if (encap)
1300			skb_reset_inner_headers(skb);
1301		skb->network_header = (u8 *)iph - skb->head;
1302	} while ((skb = skb->next));
1303
1304out:
1305	return segs;
1306}
1307
1308static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1309					 struct sk_buff *skb)
1310{
1311	const struct net_offload *ops;
1312	struct sk_buff **pp = NULL;
1313	struct sk_buff *p;
1314	const struct iphdr *iph;
1315	unsigned int hlen;
1316	unsigned int off;
1317	unsigned int id;
1318	int flush = 1;
1319	int proto;
1320
1321	off = skb_gro_offset(skb);
1322	hlen = off + sizeof(*iph);
1323	iph = skb_gro_header_fast(skb, off);
1324	if (skb_gro_header_hard(skb, hlen)) {
1325		iph = skb_gro_header_slow(skb, hlen, off);
1326		if (unlikely(!iph))
1327			goto out;
1328	}
1329
1330	proto = iph->protocol;
1331
1332	rcu_read_lock();
1333	ops = rcu_dereference(inet_offloads[proto]);
1334	if (!ops || !ops->callbacks.gro_receive)
1335		goto out_unlock;
1336
1337	if (*(u8 *)iph != 0x45)
1338		goto out_unlock;
1339
1340	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1341		goto out_unlock;
1342
1343	id = ntohl(*(__be32 *)&iph->id);
1344	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1345	id >>= 16;
1346
1347	for (p = *head; p; p = p->next) {
1348		struct iphdr *iph2;
1349
1350		if (!NAPI_GRO_CB(p)->same_flow)
1351			continue;
1352
1353		iph2 = (struct iphdr *)(p->data + off);
1354		/* The above works because, with the exception of the top
1355		 * (inner most) layer, we only aggregate pkts with the same
1356		 * hdr length so all the hdrs we'll need to verify will start
1357		 * at the same offset.
1358		 */
1359		if ((iph->protocol ^ iph2->protocol) |
1360		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1361		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1362			NAPI_GRO_CB(p)->same_flow = 0;
1363			continue;
1364		}
1365
1366		/* All fields must match except length and checksum. */
1367		NAPI_GRO_CB(p)->flush |=
1368			(iph->ttl ^ iph2->ttl) |
1369			(iph->tos ^ iph2->tos) |
1370			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1371
1372		/* Save the IP ID check to be included later when we get to
1373		 * the transport layer so only the inner most IP ID is checked.
1374		 * This is because some GSO/TSO implementations do not
1375		 * correctly increment the IP ID for the outer hdrs.
1376		 */
1377		NAPI_GRO_CB(p)->flush_id =
1378			    ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1379		NAPI_GRO_CB(p)->flush |= flush;
1380	}
1381
1382	NAPI_GRO_CB(skb)->flush |= flush;
1383	skb_set_network_header(skb, off);
1384	/* The above will be needed by the transport layer if there is one
1385	 * immediately following this IP hdr.
1386	 */
1387
1388	/* Note : No need to call skb_gro_postpull_rcsum() here,
1389	 * as we already checked checksum over ipv4 header was 0
1390	 */
1391	skb_gro_pull(skb, sizeof(*iph));
1392	skb_set_transport_header(skb, skb_gro_offset(skb));
1393
1394	pp = ops->callbacks.gro_receive(head, skb);
1395
1396out_unlock:
1397	rcu_read_unlock();
1398
1399out:
1400	NAPI_GRO_CB(skb)->flush |= flush;
1401
1402	return pp;
1403}
1404
1405int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1406{
1407	if (sk->sk_family == AF_INET)
1408		return ip_recv_error(sk, msg, len, addr_len);
1409#if IS_ENABLED(CONFIG_IPV6)
1410	if (sk->sk_family == AF_INET6)
1411		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1412#endif
1413	return -EINVAL;
1414}
1415
1416static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1417{
1418	__be16 newlen = htons(skb->len - nhoff);
1419	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1420	const struct net_offload *ops;
1421	int proto = iph->protocol;
1422	int err = -ENOSYS;
1423
1424	if (skb->encapsulation)
1425		skb_set_inner_network_header(skb, nhoff);
1426
1427	csum_replace2(&iph->check, iph->tot_len, newlen);
1428	iph->tot_len = newlen;
1429
1430	rcu_read_lock();
1431	ops = rcu_dereference(inet_offloads[proto]);
1432	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1433		goto out_unlock;
1434
1435	/* Only need to add sizeof(*iph) to get to the next hdr below
1436	 * because any hdr with option will have been flushed in
1437	 * inet_gro_receive().
1438	 */
1439	err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1440
1441out_unlock:
1442	rcu_read_unlock();
1443
1444	return err;
1445}
1446
1447int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1448			 unsigned short type, unsigned char protocol,
1449			 struct net *net)
1450{
1451	struct socket *sock;
1452	int rc = sock_create_kern(family, type, protocol, &sock);
1453
1454	if (rc == 0) {
1455		*sk = sock->sk;
1456		(*sk)->sk_allocation = GFP_ATOMIC;
1457		/*
1458		 * Unhash it so that IP input processing does not even see it,
1459		 * we do not wish this socket to see incoming packets.
1460		 */
1461		(*sk)->sk_prot->unhash(*sk);
1462
1463		sk_change_net(*sk, net);
1464	}
1465	return rc;
1466}
1467EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1468
1469unsigned long snmp_fold_field(void __percpu *mib, int offt)
1470{
1471	unsigned long res = 0;
1472	int i;
1473
1474	for_each_possible_cpu(i)
1475		res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
1476	return res;
1477}
1478EXPORT_SYMBOL_GPL(snmp_fold_field);
1479
1480#if BITS_PER_LONG==32
1481
1482u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1483{
1484	u64 res = 0;
1485	int cpu;
1486
1487	for_each_possible_cpu(cpu) {
1488		void *bhptr;
1489		struct u64_stats_sync *syncp;
1490		u64 v;
1491		unsigned int start;
1492
1493		bhptr = per_cpu_ptr(mib, cpu);
1494		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1495		do {
1496			start = u64_stats_fetch_begin_irq(syncp);
1497			v = *(((u64 *) bhptr) + offt);
1498		} while (u64_stats_fetch_retry_irq(syncp, start));
1499
1500		res += v;
1501	}
1502	return res;
1503}
1504EXPORT_SYMBOL_GPL(snmp_fold_field64);
1505#endif
1506
1507#ifdef CONFIG_IP_MULTICAST
1508static const struct net_protocol igmp_protocol = {
1509	.handler =	igmp_rcv,
1510	.netns_ok =	1,
1511};
1512#endif
1513
1514static const struct net_protocol tcp_protocol = {
1515	.early_demux	=	tcp_v4_early_demux,
1516	.handler	=	tcp_v4_rcv,
1517	.err_handler	=	tcp_v4_err,
1518	.no_policy	=	1,
1519	.netns_ok	=	1,
1520	.icmp_strict_tag_validation = 1,
1521};
1522
1523static const struct net_protocol udp_protocol = {
1524	.early_demux =	udp_v4_early_demux,
1525	.handler =	udp_rcv,
1526	.err_handler =	udp_err,
1527	.no_policy =	1,
1528	.netns_ok =	1,
1529};
1530
1531static const struct net_protocol icmp_protocol = {
1532	.handler =	icmp_rcv,
1533	.err_handler =	icmp_err,
1534	.no_policy =	1,
1535	.netns_ok =	1,
1536};
1537
1538static __net_init int ipv4_mib_init_net(struct net *net)
1539{
1540	int i;
1541
1542	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1543	if (!net->mib.tcp_statistics)
1544		goto err_tcp_mib;
1545	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1546	if (!net->mib.ip_statistics)
1547		goto err_ip_mib;
1548
1549	for_each_possible_cpu(i) {
1550		struct ipstats_mib *af_inet_stats;
1551		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1552		u64_stats_init(&af_inet_stats->syncp);
1553	}
1554
1555	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1556	if (!net->mib.net_statistics)
1557		goto err_net_mib;
1558	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1559	if (!net->mib.udp_statistics)
1560		goto err_udp_mib;
1561	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1562	if (!net->mib.udplite_statistics)
1563		goto err_udplite_mib;
1564	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1565	if (!net->mib.icmp_statistics)
1566		goto err_icmp_mib;
1567	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1568					      GFP_KERNEL);
1569	if (!net->mib.icmpmsg_statistics)
1570		goto err_icmpmsg_mib;
1571
1572	tcp_mib_init(net);
1573	return 0;
1574
1575err_icmpmsg_mib:
1576	free_percpu(net->mib.icmp_statistics);
1577err_icmp_mib:
1578	free_percpu(net->mib.udplite_statistics);
1579err_udplite_mib:
1580	free_percpu(net->mib.udp_statistics);
1581err_udp_mib:
1582	free_percpu(net->mib.net_statistics);
1583err_net_mib:
1584	free_percpu(net->mib.ip_statistics);
1585err_ip_mib:
1586	free_percpu(net->mib.tcp_statistics);
1587err_tcp_mib:
1588	return -ENOMEM;
1589}
1590
1591static __net_exit void ipv4_mib_exit_net(struct net *net)
1592{
1593	kfree(net->mib.icmpmsg_statistics);
1594	free_percpu(net->mib.icmp_statistics);
1595	free_percpu(net->mib.udplite_statistics);
1596	free_percpu(net->mib.udp_statistics);
1597	free_percpu(net->mib.net_statistics);
1598	free_percpu(net->mib.ip_statistics);
1599	free_percpu(net->mib.tcp_statistics);
1600}
1601
1602static __net_initdata struct pernet_operations ipv4_mib_ops = {
1603	.init = ipv4_mib_init_net,
1604	.exit = ipv4_mib_exit_net,
1605};
1606
1607static int __init init_ipv4_mibs(void)
1608{
1609	return register_pernet_subsys(&ipv4_mib_ops);
1610}
1611
1612static __net_init int inet_init_net(struct net *net)
1613{
1614	/*
1615	 * Set defaults for local port range
1616	 */
1617	seqlock_init(&net->ipv4.ip_local_ports.lock);
1618	net->ipv4.ip_local_ports.range[0] =  32768;
1619	net->ipv4.ip_local_ports.range[1] =  61000;
1620
1621	seqlock_init(&net->ipv4.ping_group_range.lock);
1622	/*
1623	 * Sane defaults - nobody may create ping sockets.
1624	 * Boot scripts should set this to distro-specific group.
1625	 */
1626	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1627	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1628	return 0;
1629}
1630
1631static __net_exit void inet_exit_net(struct net *net)
1632{
1633}
1634
1635static __net_initdata struct pernet_operations af_inet_ops = {
1636	.init = inet_init_net,
1637	.exit = inet_exit_net,
1638};
1639
1640static int __init init_inet_pernet_ops(void)
1641{
1642	return register_pernet_subsys(&af_inet_ops);
1643}
1644
1645static int ipv4_proc_init(void);
1646
1647/*
1648 *	IP protocol layer initialiser
1649 */
1650
1651static struct packet_offload ip_packet_offload __read_mostly = {
1652	.type = cpu_to_be16(ETH_P_IP),
1653	.callbacks = {
1654		.gso_segment = inet_gso_segment,
1655		.gro_receive = inet_gro_receive,
1656		.gro_complete = inet_gro_complete,
1657	},
1658};
1659
1660static const struct net_offload ipip_offload = {
1661	.callbacks = {
1662		.gso_segment	= inet_gso_segment,
1663		.gro_receive	= inet_gro_receive,
1664		.gro_complete	= inet_gro_complete,
1665	},
1666};
1667
1668static int __init ipv4_offload_init(void)
1669{
1670	/*
1671	 * Add offloads
1672	 */
1673	if (udpv4_offload_init() < 0)
1674		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1675	if (tcpv4_offload_init() < 0)
1676		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1677
1678	dev_add_offload(&ip_packet_offload);
1679	inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1680	return 0;
1681}
1682
1683fs_initcall(ipv4_offload_init);
1684
1685static struct packet_type ip_packet_type __read_mostly = {
1686	.type = cpu_to_be16(ETH_P_IP),
1687	.func = ip_rcv,
1688};
1689
1690static int __init inet_init(void)
1691{
1692	struct inet_protosw *q;
1693	struct list_head *r;
1694	int rc = -EINVAL;
1695
1696	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1697
1698	rc = proto_register(&tcp_prot, 1);
1699	if (rc)
1700		goto out;
1701
1702	rc = proto_register(&udp_prot, 1);
1703	if (rc)
1704		goto out_unregister_tcp_proto;
1705
1706	rc = proto_register(&raw_prot, 1);
1707	if (rc)
1708		goto out_unregister_udp_proto;
1709
1710	rc = proto_register(&ping_prot, 1);
1711	if (rc)
1712		goto out_unregister_raw_proto;
1713
1714	/*
1715	 *	Tell SOCKET that we are alive...
1716	 */
1717
1718	(void)sock_register(&inet_family_ops);
1719
1720#ifdef CONFIG_SYSCTL
1721	ip_static_sysctl_init();
1722#endif
1723
1724	/*
1725	 *	Add all the base protocols.
1726	 */
1727
1728	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1729		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1730	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1731		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1732	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1733		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1734#ifdef CONFIG_IP_MULTICAST
1735	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1736		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1737#endif
1738
1739	/* Register the socket-side information for inet_create. */
1740	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1741		INIT_LIST_HEAD(r);
1742
1743	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1744		inet_register_protosw(q);
1745
1746	/*
1747	 *	Set the ARP module up
1748	 */
1749
1750	arp_init();
1751
1752	/*
1753	 *	Set the IP module up
1754	 */
1755
1756	ip_init();
1757
1758	tcp_v4_init();
1759
1760	/* Setup TCP slab cache for open requests. */
1761	tcp_init();
1762
1763	/* Setup UDP memory threshold */
1764	udp_init();
1765
1766	/* Add UDP-Lite (RFC 3828) */
1767	udplite4_register();
1768
1769	ping_init();
1770
1771	/*
1772	 *	Set the ICMP layer up
1773	 */
1774
1775	if (icmp_init() < 0)
1776		panic("Failed to create the ICMP control socket.\n");
1777
1778	/*
1779	 *	Initialise the multicast router
1780	 */
1781#if defined(CONFIG_IP_MROUTE)
1782	if (ip_mr_init())
1783		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1784#endif
1785
1786	if (init_inet_pernet_ops())
1787		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1788	/*
1789	 *	Initialise per-cpu ipv4 mibs
1790	 */
1791
1792	if (init_ipv4_mibs())
1793		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1794
1795	ipv4_proc_init();
1796
1797	ipfrag_init();
1798
1799	dev_add_pack(&ip_packet_type);
1800
1801	rc = 0;
1802out:
1803	return rc;
1804out_unregister_raw_proto:
1805	proto_unregister(&raw_prot);
1806out_unregister_udp_proto:
1807	proto_unregister(&udp_prot);
1808out_unregister_tcp_proto:
1809	proto_unregister(&tcp_prot);
1810	goto out;
1811}
1812
1813fs_initcall(inet_init);
1814
1815/* ------------------------------------------------------------------------ */
1816
1817#ifdef CONFIG_PROC_FS
1818static int __init ipv4_proc_init(void)
1819{
1820	int rc = 0;
1821
1822	if (raw_proc_init())
1823		goto out_raw;
1824	if (tcp4_proc_init())
1825		goto out_tcp;
1826	if (udp4_proc_init())
1827		goto out_udp;
1828	if (ping_proc_init())
1829		goto out_ping;
1830	if (ip_misc_proc_init())
1831		goto out_misc;
1832out:
1833	return rc;
1834out_misc:
1835	ping_proc_exit();
1836out_ping:
1837	udp4_proc_exit();
1838out_udp:
1839	tcp4_proc_exit();
1840out_tcp:
1841	raw_proc_exit();
1842out_raw:
1843	rc = -ENOMEM;
1844	goto out;
1845}
1846
1847#else /* CONFIG_PROC_FS */
1848static int __init ipv4_proc_init(void)
1849{
1850	return 0;
1851}
1852#endif /* CONFIG_PROC_FS */
1853
1854MODULE_ALIAS_NETPROTO(PF_INET);
1855
1856