1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
4 *		operating system.  INET is implemented using the  BSD Socket
5 *		interface as the means of communication with the user level.
6 *
7 *		PF_INET protocol family socket handler.
8 *
9 * Authors:	Ross Biro
10 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 *		Florian La Roche, <flla@stud.uni-sb.de>
12 *		Alan Cox, <A.Cox@swansea.ac.uk>
13 *
14 * Changes (see also sock.c)
15 *
16 *		piggy,
17 *		Karl Knutson	:	Socket protocol table
18 *		A.N.Kuznetsov	:	Socket death error in accept().
19 *		John Richardson :	Fix non blocking error in connect()
20 *					so sockets that fail to connect
21 *					don't return -EINPROGRESS.
22 *		Alan Cox	:	Asynchronous I/O support
23 *		Alan Cox	:	Keep correct socket pointer on sock
24 *					structures
25 *					when accept() ed
26 *		Alan Cox	:	Semantics of SO_LINGER aren't state
27 *					moved to close when you look carefully.
28 *					With this fixed and the accept bug fixed
29 *					some RPC stuff seems happier.
30 *		Niibe Yutaka	:	4.4BSD style write async I/O
31 *		Alan Cox,
32 *		Tony Gale 	:	Fixed reuse semantics.
33 *		Alan Cox	:	bind() shouldn't abort existing but dead
34 *					sockets. Stops FTP netin:.. I hope.
35 *		Alan Cox	:	bind() works correctly for RAW sockets.
36 *					Note that FreeBSD at least was broken
37 *					in this respect so be careful with
38 *					compatibility tests...
39 *		Alan Cox	:	routing cache support
40 *		Alan Cox	:	memzero the socket structure for
41 *					compactness.
42 *		Matt Day	:	nonblock connect error handler
43 *		Alan Cox	:	Allow large numbers of pending sockets
44 *					(eg for big web sites), but only if
45 *					specifically application requested.
46 *		Alan Cox	:	New buffering throughout IP. Used
47 *					dumbly.
48 *		Alan Cox	:	New buffering now used smartly.
49 *		Alan Cox	:	BSD rather than common sense
50 *					interpretation of listen.
51 *		Germano Caronni	:	Assorted small races.
52 *		Alan Cox	:	sendmsg/recvmsg basic support.
53 *		Alan Cox	:	Only sendmsg/recvmsg now supported.
54 *		Alan Cox	:	Locked down bind (see security list).
55 *		Alan Cox	:	Loosened bind a little.
56 *		Mike McLagan	:	ADD/DEL DLCI Ioctls
57 *	Willy Konynenberg	:	Transparent proxying support.
58 *		David S. Miller	:	New socket lookup architecture.
59 *					Some other random speedups.
60 *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
61 *		Andi Kleen	:	Fix inet_stream_connect TCP race.
62 */
63
64#define pr_fmt(fmt) "IPv4: " fmt
65
66#include <linux/err.h>
67#include <linux/errno.h>
68#include <linux/types.h>
69#include <linux/socket.h>
70#include <linux/in.h>
71#include <linux/kernel.h>
72#include <linux/kmod.h>
73#include <linux/sched.h>
74#include <linux/timer.h>
75#include <linux/string.h>
76#include <linux/sockios.h>
77#include <linux/net.h>
78#include <linux/capability.h>
79#include <linux/fcntl.h>
80#include <linux/mm.h>
81#include <linux/interrupt.h>
82#include <linux/stat.h>
83#include <linux/init.h>
84#include <linux/poll.h>
85#include <linux/netfilter_ipv4.h>
86#include <linux/random.h>
87#include <linux/slab.h>
88
89#include <linux/uaccess.h>
90
91#include <linux/inet.h>
92#include <linux/igmp.h>
93#include <linux/inetdevice.h>
94#include <linux/netdevice.h>
95#include <net/checksum.h>
96#include <net/ip.h>
97#include <net/protocol.h>
98#include <net/arp.h>
99#include <net/route.h>
100#include <net/ip_fib.h>
101#include <net/inet_connection_sock.h>
102#include <net/gro.h>
103#include <net/gso.h>
104#include <net/tcp.h>
105#include <net/udp.h>
106#include <net/udplite.h>
107#include <net/ping.h>
108#include <linux/skbuff.h>
109#include <net/sock.h>
110#include <net/raw.h>
111#include <net/icmp.h>
112#include <net/inet_common.h>
113#include <net/ip_tunnels.h>
114#include <net/xfrm.h>
115#include <net/net_namespace.h>
116#include <net/secure_seq.h>
117#ifdef CONFIG_IP_MROUTE
118#include <linux/mroute.h>
119#endif
120#include <net/l3mdev.h>
121#include <net/compat.h>
122#include <net/rps.h>
123
124#include <trace/events/sock.h>
125
126/* The inetsw table contains everything that inet_create needs to
127 * build a new socket.
128 */
129static struct list_head inetsw[SOCK_MAX];
130static DEFINE_SPINLOCK(inetsw_lock);
131
132/* New destruction routine */
133
134void inet_sock_destruct(struct sock *sk)
135{
136	struct inet_sock *inet = inet_sk(sk);
137
138	__skb_queue_purge(&sk->sk_receive_queue);
139	__skb_queue_purge(&sk->sk_error_queue);
140
141	sk_mem_reclaim_final(sk);
142
143	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
144		pr_err("Attempt to release TCP socket in state %d %p\n",
145		       sk->sk_state, sk);
146		return;
147	}
148	if (!sock_flag(sk, SOCK_DEAD)) {
149		pr_err("Attempt to release alive inet socket %p\n", sk);
150		return;
151	}
152
153	WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));
154	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
155	WARN_ON_ONCE(sk->sk_wmem_queued);
156	WARN_ON_ONCE(sk_forward_alloc_get(sk));
157
158	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
160	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
161}
162EXPORT_SYMBOL(inet_sock_destruct);
163
164/*
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
167 *	the work.
168 */
169
170/*
171 *	Automatically bind an unbound socket.
172 */
173
174static int inet_autobind(struct sock *sk)
175{
176	struct inet_sock *inet;
177	/* We may need to bind the socket. */
178	lock_sock(sk);
179	inet = inet_sk(sk);
180	if (!inet->inet_num) {
181		if (sk->sk_prot->get_port(sk, 0)) {
182			release_sock(sk);
183			return -EAGAIN;
184		}
185		inet->inet_sport = htons(inet->inet_num);
186	}
187	release_sock(sk);
188	return 0;
189}
190
191int __inet_listen_sk(struct sock *sk, int backlog)
192{
193	unsigned char old_state = sk->sk_state;
194	int err, tcp_fastopen;
195
196	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
197		return -EINVAL;
198
199	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
200	/* Really, if the socket is already in listen state
201	 * we can only allow the backlog to be adjusted.
202	 */
203	if (old_state != TCP_LISTEN) {
204		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
205		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
206		 * Also fastopen backlog may already been set via the option
207		 * because the socket was in TCP_LISTEN state previously but
208		 * was shutdown() rather than close().
209		 */
210		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
211		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
212		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
213		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
214			fastopen_queue_tune(sk, backlog);
215			tcp_fastopen_init_key_once(sock_net(sk));
216		}
217
218		err = inet_csk_listen_start(sk);
219		if (err)
220			return err;
221
222		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
223	}
224	return 0;
225}
226
227/*
228 *	Move a socket into listening state.
229 */
230int inet_listen(struct socket *sock, int backlog)
231{
232	struct sock *sk = sock->sk;
233	int err = -EINVAL;
234
235	lock_sock(sk);
236
237	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
238		goto out;
239
240	err = __inet_listen_sk(sk, backlog);
241
242out:
243	release_sock(sk);
244	return err;
245}
246EXPORT_SYMBOL(inet_listen);
247
248/*
249 *	Create an inet socket.
250 */
251
252static int inet_create(struct net *net, struct socket *sock, int protocol,
253		       int kern)
254{
255	struct sock *sk;
256	struct inet_protosw *answer;
257	struct inet_sock *inet;
258	struct proto *answer_prot;
259	unsigned char answer_flags;
260	int try_loading_module = 0;
261	int err;
262
263	if (protocol < 0 || protocol >= IPPROTO_MAX)
264		return -EINVAL;
265
266	sock->state = SS_UNCONNECTED;
267
268	/* Look for the requested type/protocol pair. */
269lookup_protocol:
270	err = -ESOCKTNOSUPPORT;
271	rcu_read_lock();
272	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
273
274		err = 0;
275		/* Check the non-wild match. */
276		if (protocol == answer->protocol) {
277			if (protocol != IPPROTO_IP)
278				break;
279		} else {
280			/* Check for the two wild cases. */
281			if (IPPROTO_IP == protocol) {
282				protocol = answer->protocol;
283				break;
284			}
285			if (IPPROTO_IP == answer->protocol)
286				break;
287		}
288		err = -EPROTONOSUPPORT;
289	}
290
291	if (unlikely(err)) {
292		if (try_loading_module < 2) {
293			rcu_read_unlock();
294			/*
295			 * Be more specific, e.g. net-pf-2-proto-132-type-1
296			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
297			 */
298			if (++try_loading_module == 1)
299				request_module("net-pf-%d-proto-%d-type-%d",
300					       PF_INET, protocol, sock->type);
301			/*
302			 * Fall back to generic, e.g. net-pf-2-proto-132
303			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
304			 */
305			else
306				request_module("net-pf-%d-proto-%d",
307					       PF_INET, protocol);
308			goto lookup_protocol;
309		} else
310			goto out_rcu_unlock;
311	}
312
313	err = -EPERM;
314	if (sock->type == SOCK_RAW && !kern &&
315	    !ns_capable(net->user_ns, CAP_NET_RAW))
316		goto out_rcu_unlock;
317
318	sock->ops = answer->ops;
319	answer_prot = answer->prot;
320	answer_flags = answer->flags;
321	rcu_read_unlock();
322
323	WARN_ON(!answer_prot->slab);
324
325	err = -ENOMEM;
326	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
327	if (!sk)
328		goto out;
329
330	err = 0;
331	if (INET_PROTOSW_REUSE & answer_flags)
332		sk->sk_reuse = SK_CAN_REUSE;
333
334	if (INET_PROTOSW_ICSK & answer_flags)
335		inet_init_csk_locks(sk);
336
337	inet = inet_sk(sk);
338	inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
339
340	inet_clear_bit(NODEFRAG, sk);
341
342	if (SOCK_RAW == sock->type) {
343		inet->inet_num = protocol;
344		if (IPPROTO_RAW == protocol)
345			inet_set_bit(HDRINCL, sk);
346	}
347
348	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
349		inet->pmtudisc = IP_PMTUDISC_DONT;
350	else
351		inet->pmtudisc = IP_PMTUDISC_WANT;
352
353	atomic_set(&inet->inet_id, 0);
354
355	sock_init_data(sock, sk);
356
357	sk->sk_destruct	   = inet_sock_destruct;
358	sk->sk_protocol	   = protocol;
359	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
360	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
361
362	inet->uc_ttl	= -1;
363	inet_set_bit(MC_LOOP, sk);
364	inet->mc_ttl	= 1;
365	inet_set_bit(MC_ALL, sk);
366	inet->mc_index	= 0;
367	inet->mc_list	= NULL;
368	inet->rcv_tos	= 0;
369
370	if (inet->inet_num) {
371		/* It assumes that any protocol which allows
372		 * the user to assign a number at socket
373		 * creation time automatically
374		 * shares.
375		 */
376		inet->inet_sport = htons(inet->inet_num);
377		/* Add to protocol hash chains. */
378		err = sk->sk_prot->hash(sk);
379		if (err) {
380			sk_common_release(sk);
381			goto out;
382		}
383	}
384
385	if (sk->sk_prot->init) {
386		err = sk->sk_prot->init(sk);
387		if (err) {
388			sk_common_release(sk);
389			goto out;
390		}
391	}
392
393	if (!kern) {
394		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
395		if (err) {
396			sk_common_release(sk);
397			goto out;
398		}
399	}
400out:
401	return err;
402out_rcu_unlock:
403	rcu_read_unlock();
404	goto out;
405}
406
407
408/*
409 *	The peer socket should always be NULL (or else). When we call this
410 *	function we are destroying the object and from then on nobody
411 *	should refer to it.
412 */
413int inet_release(struct socket *sock)
414{
415	struct sock *sk = sock->sk;
416
417	if (sk) {
418		long timeout;
419
420		if (!sk->sk_kern_sock)
421			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
422
423		/* Applications forget to leave groups before exiting */
424		ip_mc_drop_socket(sk);
425
426		/* If linger is set, we don't return until the close
427		 * is complete.  Otherwise we return immediately. The
428		 * actually closing is done the same either way.
429		 *
430		 * If the close is due to the process exiting, we never
431		 * linger..
432		 */
433		timeout = 0;
434		if (sock_flag(sk, SOCK_LINGER) &&
435		    !(current->flags & PF_EXITING))
436			timeout = sk->sk_lingertime;
437		sk->sk_prot->close(sk, timeout);
438		sock->sk = NULL;
439	}
440	return 0;
441}
442EXPORT_SYMBOL(inet_release);
443
444int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
445{
446	u32 flags = BIND_WITH_LOCK;
447	int err;
448
449	/* If the socket has its own bind function then use it. (RAW) */
450	if (sk->sk_prot->bind) {
451		return sk->sk_prot->bind(sk, uaddr, addr_len);
452	}
453	if (addr_len < sizeof(struct sockaddr_in))
454		return -EINVAL;
455
456	/* BPF prog is run before any checks are done so that if the prog
457	 * changes context in a wrong way it will be caught.
458	 */
459	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len,
460						 CGROUP_INET4_BIND, &flags);
461	if (err)
462		return err;
463
464	return __inet_bind(sk, uaddr, addr_len, flags);
465}
466
467int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
468{
469	return inet_bind_sk(sock->sk, uaddr, addr_len);
470}
471EXPORT_SYMBOL(inet_bind);
472
473int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
474		u32 flags)
475{
476	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
477	struct inet_sock *inet = inet_sk(sk);
478	struct net *net = sock_net(sk);
479	unsigned short snum;
480	int chk_addr_ret;
481	u32 tb_id = RT_TABLE_LOCAL;
482	int err;
483
484	if (addr->sin_family != AF_INET) {
485		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
486		 * only if s_addr is INADDR_ANY.
487		 */
488		err = -EAFNOSUPPORT;
489		if (addr->sin_family != AF_UNSPEC ||
490		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
491			goto out;
492	}
493
494	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
495	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
496
497	/* Not specified by any standard per-se, however it breaks too
498	 * many applications when removed.  It is unfortunate since
499	 * allowing applications to make a non-local bind solves
500	 * several problems with systems using dynamic addressing.
501	 * (ie. your servers still start up even if your ISDN link
502	 *  is temporarily down)
503	 */
504	err = -EADDRNOTAVAIL;
505	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
506	                                 chk_addr_ret))
507		goto out;
508
509	snum = ntohs(addr->sin_port);
510	err = -EACCES;
511	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
512	    snum && inet_port_requires_bind_service(net, snum) &&
513	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
514		goto out;
515
516	/*      We keep a pair of addresses. rcv_saddr is the one
517	 *      used by hash lookups, and saddr is used for transmit.
518	 *
519	 *      In the BSD API these are the same except where it
520	 *      would be illegal to use them (multicast/broadcast) in
521	 *      which case the sending device address is used.
522	 */
523	if (flags & BIND_WITH_LOCK)
524		lock_sock(sk);
525
526	/* Check these errors (active socket, double bind). */
527	err = -EINVAL;
528	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
529		goto out_release_sock;
530
531	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
532	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
533		inet->inet_saddr = 0;  /* Use device */
534
535	/* Make sure we are allowed to bind here. */
536	if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
537		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
538		err = sk->sk_prot->get_port(sk, snum);
539		if (err) {
540			inet->inet_saddr = inet->inet_rcv_saddr = 0;
541			goto out_release_sock;
542		}
543		if (!(flags & BIND_FROM_BPF)) {
544			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
545			if (err) {
546				inet->inet_saddr = inet->inet_rcv_saddr = 0;
547				if (sk->sk_prot->put_port)
548					sk->sk_prot->put_port(sk);
549				goto out_release_sock;
550			}
551		}
552	}
553
554	if (inet->inet_rcv_saddr)
555		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
556	if (snum)
557		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
558	inet->inet_sport = htons(inet->inet_num);
559	inet->inet_daddr = 0;
560	inet->inet_dport = 0;
561	sk_dst_reset(sk);
562	err = 0;
563out_release_sock:
564	if (flags & BIND_WITH_LOCK)
565		release_sock(sk);
566out:
567	return err;
568}
569
570int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
571		       int addr_len, int flags)
572{
573	struct sock *sk = sock->sk;
574	const struct proto *prot;
575	int err;
576
577	if (addr_len < sizeof(uaddr->sa_family))
578		return -EINVAL;
579
580	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
581	prot = READ_ONCE(sk->sk_prot);
582
583	if (uaddr->sa_family == AF_UNSPEC)
584		return prot->disconnect(sk, flags);
585
586	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
587		err = prot->pre_connect(sk, uaddr, addr_len);
588		if (err)
589			return err;
590	}
591
592	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
593		return -EAGAIN;
594	return prot->connect(sk, uaddr, addr_len);
595}
596EXPORT_SYMBOL(inet_dgram_connect);
597
598static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
599{
600	DEFINE_WAIT_FUNC(wait, woken_wake_function);
601
602	add_wait_queue(sk_sleep(sk), &wait);
603	sk->sk_write_pending += writebias;
604
605	/* Basic assumption: if someone sets sk->sk_err, he _must_
606	 * change state of the socket from TCP_SYN_*.
607	 * Connect() does not allow to get error notifications
608	 * without closing the socket.
609	 */
610	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
611		release_sock(sk);
612		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
613		lock_sock(sk);
614		if (signal_pending(current) || !timeo)
615			break;
616	}
617	remove_wait_queue(sk_sleep(sk), &wait);
618	sk->sk_write_pending -= writebias;
619	return timeo;
620}
621
622/*
623 *	Connect to a remote host. There is regrettably still a little
624 *	TCP 'magic' in here.
625 */
626int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
627			  int addr_len, int flags, int is_sendmsg)
628{
629	struct sock *sk = sock->sk;
630	int err;
631	long timeo;
632
633	/*
634	 * uaddr can be NULL and addr_len can be 0 if:
635	 * sk is a TCP fastopen active socket and
636	 * TCP_FASTOPEN_CONNECT sockopt is set and
637	 * we already have a valid cookie for this socket.
638	 * In this case, user can call write() after connect().
639	 * write() will invoke tcp_sendmsg_fastopen() which calls
640	 * __inet_stream_connect().
641	 */
642	if (uaddr) {
643		if (addr_len < sizeof(uaddr->sa_family))
644			return -EINVAL;
645
646		if (uaddr->sa_family == AF_UNSPEC) {
647			sk->sk_disconnects++;
648			err = sk->sk_prot->disconnect(sk, flags);
649			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
650			goto out;
651		}
652	}
653
654	switch (sock->state) {
655	default:
656		err = -EINVAL;
657		goto out;
658	case SS_CONNECTED:
659		err = -EISCONN;
660		goto out;
661	case SS_CONNECTING:
662		if (inet_test_bit(DEFER_CONNECT, sk))
663			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
664		else
665			err = -EALREADY;
666		/* Fall out of switch with err, set for this state */
667		break;
668	case SS_UNCONNECTED:
669		err = -EISCONN;
670		if (sk->sk_state != TCP_CLOSE)
671			goto out;
672
673		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
674			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
675			if (err)
676				goto out;
677		}
678
679		err = sk->sk_prot->connect(sk, uaddr, addr_len);
680		if (err < 0)
681			goto out;
682
683		sock->state = SS_CONNECTING;
684
685		if (!err && inet_test_bit(DEFER_CONNECT, sk))
686			goto out;
687
688		/* Just entered SS_CONNECTING state; the only
689		 * difference is that return value in non-blocking
690		 * case is EINPROGRESS, rather than EALREADY.
691		 */
692		err = -EINPROGRESS;
693		break;
694	}
695
696	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
697
698	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
699		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
700				tcp_sk(sk)->fastopen_req &&
701				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
702		int dis = sk->sk_disconnects;
703
704		/* Error code is set above */
705		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
706			goto out;
707
708		err = sock_intr_errno(timeo);
709		if (signal_pending(current))
710			goto out;
711
712		if (dis != sk->sk_disconnects) {
713			err = -EPIPE;
714			goto out;
715		}
716	}
717
718	/* Connection was closed by RST, timeout, ICMP error
719	 * or another process disconnected us.
720	 */
721	if (sk->sk_state == TCP_CLOSE)
722		goto sock_error;
723
724	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
725	 * and error was received after socket entered established state.
726	 * Hence, it is handled normally after connect() return successfully.
727	 */
728
729	sock->state = SS_CONNECTED;
730	err = 0;
731out:
732	return err;
733
734sock_error:
735	err = sock_error(sk) ? : -ECONNABORTED;
736	sock->state = SS_UNCONNECTED;
737	sk->sk_disconnects++;
738	if (sk->sk_prot->disconnect(sk, flags))
739		sock->state = SS_DISCONNECTING;
740	goto out;
741}
742EXPORT_SYMBOL(__inet_stream_connect);
743
744int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
745			int addr_len, int flags)
746{
747	int err;
748
749	lock_sock(sock->sk);
750	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
751	release_sock(sock->sk);
752	return err;
753}
754EXPORT_SYMBOL(inet_stream_connect);
755
756void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
757{
758	sock_rps_record_flow(newsk);
759	WARN_ON(!((1 << newsk->sk_state) &
760		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
761		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
762
763	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
764		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
765	sock_graft(newsk, newsock);
766
767	newsock->state = SS_CONNECTED;
768}
769
770/*
771 *	Accept a pending connection. The TCP layer now gives BSD semantics.
772 */
773
774int inet_accept(struct socket *sock, struct socket *newsock, int flags,
775		bool kern)
776{
777	struct sock *sk1 = sock->sk, *sk2;
778	int err = -EINVAL;
779
780	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
781	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
782	if (!sk2)
783		return err;
784
785	lock_sock(sk2);
786	__inet_accept(sock, newsock, sk2);
787	release_sock(sk2);
788	return 0;
789}
790EXPORT_SYMBOL(inet_accept);
791
792/*
793 *	This does both peername and sockname.
794 */
795int inet_getname(struct socket *sock, struct sockaddr *uaddr,
796		 int peer)
797{
798	struct sock *sk		= sock->sk;
799	struct inet_sock *inet	= inet_sk(sk);
800	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
801	int sin_addr_len = sizeof(*sin);
802
803	sin->sin_family = AF_INET;
804	lock_sock(sk);
805	if (peer) {
806		if (!inet->inet_dport ||
807		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
808		     peer == 1)) {
809			release_sock(sk);
810			return -ENOTCONN;
811		}
812		sin->sin_port = inet->inet_dport;
813		sin->sin_addr.s_addr = inet->inet_daddr;
814		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
815				       CGROUP_INET4_GETPEERNAME);
816	} else {
817		__be32 addr = inet->inet_rcv_saddr;
818		if (!addr)
819			addr = inet->inet_saddr;
820		sin->sin_port = inet->inet_sport;
821		sin->sin_addr.s_addr = addr;
822		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
823				       CGROUP_INET4_GETSOCKNAME);
824	}
825	release_sock(sk);
826	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
827	return sin_addr_len;
828}
829EXPORT_SYMBOL(inet_getname);
830
831int inet_send_prepare(struct sock *sk)
832{
833	sock_rps_record_flow(sk);
834
835	/* We may need to bind the socket. */
836	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
837	    inet_autobind(sk))
838		return -EAGAIN;
839
840	return 0;
841}
842EXPORT_SYMBOL_GPL(inet_send_prepare);
843
844int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
845{
846	struct sock *sk = sock->sk;
847
848	if (unlikely(inet_send_prepare(sk)))
849		return -EAGAIN;
850
851	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
852			       sk, msg, size);
853}
854EXPORT_SYMBOL(inet_sendmsg);
855
856void inet_splice_eof(struct socket *sock)
857{
858	const struct proto *prot;
859	struct sock *sk = sock->sk;
860
861	if (unlikely(inet_send_prepare(sk)))
862		return;
863
864	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
865	prot = READ_ONCE(sk->sk_prot);
866	if (prot->splice_eof)
867		prot->splice_eof(sock);
868}
869EXPORT_SYMBOL_GPL(inet_splice_eof);
870
871INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
872					  size_t, int, int *));
873int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
874		 int flags)
875{
876	struct sock *sk = sock->sk;
877	int addr_len = 0;
878	int err;
879
880	if (likely(!(flags & MSG_ERRQUEUE)))
881		sock_rps_record_flow(sk);
882
883	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
884			      sk, msg, size, flags, &addr_len);
885	if (err >= 0)
886		msg->msg_namelen = addr_len;
887	return err;
888}
889EXPORT_SYMBOL(inet_recvmsg);
890
891int inet_shutdown(struct socket *sock, int how)
892{
893	struct sock *sk = sock->sk;
894	int err = 0;
895
896	/* This should really check to make sure
897	 * the socket is a TCP socket. (WHY AC...)
898	 */
899	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
900		       1->2 bit 2 snds.
901		       2->3 */
902	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
903		return -EINVAL;
904
905	lock_sock(sk);
906	if (sock->state == SS_CONNECTING) {
907		if ((1 << sk->sk_state) &
908		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
909			sock->state = SS_DISCONNECTING;
910		else
911			sock->state = SS_CONNECTED;
912	}
913
914	switch (sk->sk_state) {
915	case TCP_CLOSE:
916		err = -ENOTCONN;
917		/* Hack to wake up other listeners, who can poll for
918		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
919		fallthrough;
920	default:
921		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
922		if (sk->sk_prot->shutdown)
923			sk->sk_prot->shutdown(sk, how);
924		break;
925
926	/* Remaining two branches are temporary solution for missing
927	 * close() in multithreaded environment. It is _not_ a good idea,
928	 * but we have no choice until close() is repaired at VFS level.
929	 */
930	case TCP_LISTEN:
931		if (!(how & RCV_SHUTDOWN))
932			break;
933		fallthrough;
934	case TCP_SYN_SENT:
935		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
936		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
937		break;
938	}
939
940	/* Wake up anyone sleeping in poll. */
941	sk->sk_state_change(sk);
942	release_sock(sk);
943	return err;
944}
945EXPORT_SYMBOL(inet_shutdown);
946
947/*
948 *	ioctl() calls you can issue on an INET socket. Most of these are
949 *	device configuration and stuff and very rarely used. Some ioctls
950 *	pass on to the socket itself.
951 *
952 *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
953 *	loads the devconfigure module does its configuring and unloads it.
954 *	There's a good 20K of config code hanging around the kernel.
955 */
956
957int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
958{
959	struct sock *sk = sock->sk;
960	int err = 0;
961	struct net *net = sock_net(sk);
962	void __user *p = (void __user *)arg;
963	struct ifreq ifr;
964	struct rtentry rt;
965
966	switch (cmd) {
967	case SIOCADDRT:
968	case SIOCDELRT:
969		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
970			return -EFAULT;
971		err = ip_rt_ioctl(net, cmd, &rt);
972		break;
973	case SIOCRTMSG:
974		err = -EINVAL;
975		break;
976	case SIOCDARP:
977	case SIOCGARP:
978	case SIOCSARP:
979		err = arp_ioctl(net, cmd, (void __user *)arg);
980		break;
981	case SIOCGIFADDR:
982	case SIOCGIFBRDADDR:
983	case SIOCGIFNETMASK:
984	case SIOCGIFDSTADDR:
985	case SIOCGIFPFLAGS:
986		if (get_user_ifreq(&ifr, NULL, p))
987			return -EFAULT;
988		err = devinet_ioctl(net, cmd, &ifr);
989		if (!err && put_user_ifreq(&ifr, p))
990			err = -EFAULT;
991		break;
992
993	case SIOCSIFADDR:
994	case SIOCSIFBRDADDR:
995	case SIOCSIFNETMASK:
996	case SIOCSIFDSTADDR:
997	case SIOCSIFPFLAGS:
998	case SIOCSIFFLAGS:
999		if (get_user_ifreq(&ifr, NULL, p))
1000			return -EFAULT;
1001		err = devinet_ioctl(net, cmd, &ifr);
1002		break;
1003	default:
1004		if (sk->sk_prot->ioctl)
1005			err = sk_ioctl(sk, cmd, (void __user *)arg);
1006		else
1007			err = -ENOIOCTLCMD;
1008		break;
1009	}
1010	return err;
1011}
1012EXPORT_SYMBOL(inet_ioctl);
1013
1014#ifdef CONFIG_COMPAT
1015static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1016		struct compat_rtentry __user *ur)
1017{
1018	compat_uptr_t rtdev;
1019	struct rtentry rt;
1020
1021	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1022			3 * sizeof(struct sockaddr)) ||
1023	    get_user(rt.rt_flags, &ur->rt_flags) ||
1024	    get_user(rt.rt_metric, &ur->rt_metric) ||
1025	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1026	    get_user(rt.rt_window, &ur->rt_window) ||
1027	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1028	    get_user(rtdev, &ur->rt_dev))
1029		return -EFAULT;
1030
1031	rt.rt_dev = compat_ptr(rtdev);
1032	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1033}
1034
1035static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1036{
1037	void __user *argp = compat_ptr(arg);
1038	struct sock *sk = sock->sk;
1039
1040	switch (cmd) {
1041	case SIOCADDRT:
1042	case SIOCDELRT:
1043		return inet_compat_routing_ioctl(sk, cmd, argp);
1044	default:
1045		if (!sk->sk_prot->compat_ioctl)
1046			return -ENOIOCTLCMD;
1047		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1048	}
1049}
1050#endif /* CONFIG_COMPAT */
1051
1052const struct proto_ops inet_stream_ops = {
1053	.family		   = PF_INET,
1054	.owner		   = THIS_MODULE,
1055	.release	   = inet_release,
1056	.bind		   = inet_bind,
1057	.connect	   = inet_stream_connect,
1058	.socketpair	   = sock_no_socketpair,
1059	.accept		   = inet_accept,
1060	.getname	   = inet_getname,
1061	.poll		   = tcp_poll,
1062	.ioctl		   = inet_ioctl,
1063	.gettstamp	   = sock_gettstamp,
1064	.listen		   = inet_listen,
1065	.shutdown	   = inet_shutdown,
1066	.setsockopt	   = sock_common_setsockopt,
1067	.getsockopt	   = sock_common_getsockopt,
1068	.sendmsg	   = inet_sendmsg,
1069	.recvmsg	   = inet_recvmsg,
1070#ifdef CONFIG_MMU
1071	.mmap		   = tcp_mmap,
1072#endif
1073	.splice_eof	   = inet_splice_eof,
1074	.splice_read	   = tcp_splice_read,
1075	.read_sock	   = tcp_read_sock,
1076	.read_skb	   = tcp_read_skb,
1077	.sendmsg_locked    = tcp_sendmsg_locked,
1078	.peek_len	   = tcp_peek_len,
1079#ifdef CONFIG_COMPAT
1080	.compat_ioctl	   = inet_compat_ioctl,
1081#endif
1082	.set_rcvlowat	   = tcp_set_rcvlowat,
1083};
1084EXPORT_SYMBOL(inet_stream_ops);
1085
1086const struct proto_ops inet_dgram_ops = {
1087	.family		   = PF_INET,
1088	.owner		   = THIS_MODULE,
1089	.release	   = inet_release,
1090	.bind		   = inet_bind,
1091	.connect	   = inet_dgram_connect,
1092	.socketpair	   = sock_no_socketpair,
1093	.accept		   = sock_no_accept,
1094	.getname	   = inet_getname,
1095	.poll		   = udp_poll,
1096	.ioctl		   = inet_ioctl,
1097	.gettstamp	   = sock_gettstamp,
1098	.listen		   = sock_no_listen,
1099	.shutdown	   = inet_shutdown,
1100	.setsockopt	   = sock_common_setsockopt,
1101	.getsockopt	   = sock_common_getsockopt,
1102	.sendmsg	   = inet_sendmsg,
1103	.read_skb	   = udp_read_skb,
1104	.recvmsg	   = inet_recvmsg,
1105	.mmap		   = sock_no_mmap,
1106	.splice_eof	   = inet_splice_eof,
1107	.set_peek_off	   = udp_set_peek_off,
1108#ifdef CONFIG_COMPAT
1109	.compat_ioctl	   = inet_compat_ioctl,
1110#endif
1111};
1112EXPORT_SYMBOL(inet_dgram_ops);
1113
1114/*
1115 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1116 * udp_poll
1117 */
1118static const struct proto_ops inet_sockraw_ops = {
1119	.family		   = PF_INET,
1120	.owner		   = THIS_MODULE,
1121	.release	   = inet_release,
1122	.bind		   = inet_bind,
1123	.connect	   = inet_dgram_connect,
1124	.socketpair	   = sock_no_socketpair,
1125	.accept		   = sock_no_accept,
1126	.getname	   = inet_getname,
1127	.poll		   = datagram_poll,
1128	.ioctl		   = inet_ioctl,
1129	.gettstamp	   = sock_gettstamp,
1130	.listen		   = sock_no_listen,
1131	.shutdown	   = inet_shutdown,
1132	.setsockopt	   = sock_common_setsockopt,
1133	.getsockopt	   = sock_common_getsockopt,
1134	.sendmsg	   = inet_sendmsg,
1135	.recvmsg	   = inet_recvmsg,
1136	.mmap		   = sock_no_mmap,
1137	.splice_eof	   = inet_splice_eof,
1138#ifdef CONFIG_COMPAT
1139	.compat_ioctl	   = inet_compat_ioctl,
1140#endif
1141};
1142
1143static const struct net_proto_family inet_family_ops = {
1144	.family = PF_INET,
1145	.create = inet_create,
1146	.owner	= THIS_MODULE,
1147};
1148
1149/* Upon startup we insert all the elements in inetsw_array[] into
1150 * the linked list inetsw.
1151 */
1152static struct inet_protosw inetsw_array[] =
1153{
1154	{
1155		.type =       SOCK_STREAM,
1156		.protocol =   IPPROTO_TCP,
1157		.prot =       &tcp_prot,
1158		.ops =        &inet_stream_ops,
1159		.flags =      INET_PROTOSW_PERMANENT |
1160			      INET_PROTOSW_ICSK,
1161	},
1162
1163	{
1164		.type =       SOCK_DGRAM,
1165		.protocol =   IPPROTO_UDP,
1166		.prot =       &udp_prot,
1167		.ops =        &inet_dgram_ops,
1168		.flags =      INET_PROTOSW_PERMANENT,
1169       },
1170
1171       {
1172		.type =       SOCK_DGRAM,
1173		.protocol =   IPPROTO_ICMP,
1174		.prot =       &ping_prot,
1175		.ops =        &inet_sockraw_ops,
1176		.flags =      INET_PROTOSW_REUSE,
1177       },
1178
1179       {
1180	       .type =       SOCK_RAW,
1181	       .protocol =   IPPROTO_IP,	/* wild card */
1182	       .prot =       &raw_prot,
1183	       .ops =        &inet_sockraw_ops,
1184	       .flags =      INET_PROTOSW_REUSE,
1185       }
1186};
1187
1188#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1189
1190void inet_register_protosw(struct inet_protosw *p)
1191{
1192	struct list_head *lh;
1193	struct inet_protosw *answer;
1194	int protocol = p->protocol;
1195	struct list_head *last_perm;
1196
1197	spin_lock_bh(&inetsw_lock);
1198
1199	if (p->type >= SOCK_MAX)
1200		goto out_illegal;
1201
1202	/* If we are trying to override a permanent protocol, bail. */
1203	last_perm = &inetsw[p->type];
1204	list_for_each(lh, &inetsw[p->type]) {
1205		answer = list_entry(lh, struct inet_protosw, list);
1206		/* Check only the non-wild match. */
1207		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1208			break;
1209		if (protocol == answer->protocol)
1210			goto out_permanent;
1211		last_perm = lh;
1212	}
1213
1214	/* Add the new entry after the last permanent entry if any, so that
1215	 * the new entry does not override a permanent entry when matched with
1216	 * a wild-card protocol. But it is allowed to override any existing
1217	 * non-permanent entry.  This means that when we remove this entry, the
1218	 * system automatically returns to the old behavior.
1219	 */
1220	list_add_rcu(&p->list, last_perm);
1221out:
1222	spin_unlock_bh(&inetsw_lock);
1223
1224	return;
1225
1226out_permanent:
1227	pr_err("Attempt to override permanent protocol %d\n", protocol);
1228	goto out;
1229
1230out_illegal:
1231	pr_err("Ignoring attempt to register invalid socket type %d\n",
1232	       p->type);
1233	goto out;
1234}
1235EXPORT_SYMBOL(inet_register_protosw);
1236
1237void inet_unregister_protosw(struct inet_protosw *p)
1238{
1239	if (INET_PROTOSW_PERMANENT & p->flags) {
1240		pr_err("Attempt to unregister permanent protocol %d\n",
1241		       p->protocol);
1242	} else {
1243		spin_lock_bh(&inetsw_lock);
1244		list_del_rcu(&p->list);
1245		spin_unlock_bh(&inetsw_lock);
1246
1247		synchronize_net();
1248	}
1249}
1250EXPORT_SYMBOL(inet_unregister_protosw);
1251
1252static int inet_sk_reselect_saddr(struct sock *sk)
1253{
1254	struct inet_sock *inet = inet_sk(sk);
1255	__be32 old_saddr = inet->inet_saddr;
1256	__be32 daddr = inet->inet_daddr;
1257	struct flowi4 *fl4;
1258	struct rtable *rt;
1259	__be32 new_saddr;
1260	struct ip_options_rcu *inet_opt;
1261	int err;
1262
1263	inet_opt = rcu_dereference_protected(inet->inet_opt,
1264					     lockdep_sock_is_held(sk));
1265	if (inet_opt && inet_opt->opt.srr)
1266		daddr = inet_opt->opt.faddr;
1267
1268	/* Query new route. */
1269	fl4 = &inet->cork.fl.u.ip4;
1270	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1271			      sk->sk_protocol, inet->inet_sport,
1272			      inet->inet_dport, sk);
1273	if (IS_ERR(rt))
1274		return PTR_ERR(rt);
1275
1276	new_saddr = fl4->saddr;
1277
1278	if (new_saddr == old_saddr) {
1279		sk_setup_caps(sk, &rt->dst);
1280		return 0;
1281	}
1282
1283	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1284	if (err) {
1285		ip_rt_put(rt);
1286		return err;
1287	}
1288
1289	sk_setup_caps(sk, &rt->dst);
1290
1291	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1292		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1293			__func__, &old_saddr, &new_saddr);
1294	}
1295
1296	/*
1297	 * XXX The only one ugly spot where we need to
1298	 * XXX really change the sockets identity after
1299	 * XXX it has entered the hashes. -DaveM
1300	 *
1301	 * Besides that, it does not check for connection
1302	 * uniqueness. Wait for troubles.
1303	 */
1304	return __sk_prot_rehash(sk);
1305}
1306
1307int inet_sk_rebuild_header(struct sock *sk)
1308{
1309	struct inet_sock *inet = inet_sk(sk);
1310	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1311	__be32 daddr;
1312	struct ip_options_rcu *inet_opt;
1313	struct flowi4 *fl4;
1314	int err;
1315
1316	/* Route is OK, nothing to do. */
1317	if (rt)
1318		return 0;
1319
1320	/* Reroute. */
1321	rcu_read_lock();
1322	inet_opt = rcu_dereference(inet->inet_opt);
1323	daddr = inet->inet_daddr;
1324	if (inet_opt && inet_opt->opt.srr)
1325		daddr = inet_opt->opt.faddr;
1326	rcu_read_unlock();
1327	fl4 = &inet->cork.fl.u.ip4;
1328	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1329				   inet->inet_dport, inet->inet_sport,
1330				   sk->sk_protocol, ip_sock_rt_tos(sk),
1331				   sk->sk_bound_dev_if);
1332	if (!IS_ERR(rt)) {
1333		err = 0;
1334		sk_setup_caps(sk, &rt->dst);
1335	} else {
1336		err = PTR_ERR(rt);
1337
1338		/* Routing failed... */
1339		sk->sk_route_caps = 0;
1340		/*
1341		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1342		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1343		 */
1344		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1345		    sk->sk_state != TCP_SYN_SENT ||
1346		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1347		    (err = inet_sk_reselect_saddr(sk)) != 0)
1348			WRITE_ONCE(sk->sk_err_soft, -err);
1349	}
1350
1351	return err;
1352}
1353EXPORT_SYMBOL(inet_sk_rebuild_header);
1354
1355void inet_sk_set_state(struct sock *sk, int state)
1356{
1357	trace_inet_sock_set_state(sk, sk->sk_state, state);
1358	sk->sk_state = state;
1359}
1360EXPORT_SYMBOL(inet_sk_set_state);
1361
1362void inet_sk_state_store(struct sock *sk, int newstate)
1363{
1364	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1365	smp_store_release(&sk->sk_state, newstate);
1366}
1367
1368struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1369				 netdev_features_t features)
1370{
1371	bool udpfrag = false, fixedid = false, gso_partial, encap;
1372	struct sk_buff *segs = ERR_PTR(-EINVAL);
1373	const struct net_offload *ops;
1374	unsigned int offset = 0;
1375	struct iphdr *iph;
1376	int proto, tot_len;
1377	int nhoff;
1378	int ihl;
1379	int id;
1380
1381	skb_reset_network_header(skb);
1382	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1383	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1384		goto out;
1385
1386	iph = ip_hdr(skb);
1387	ihl = iph->ihl * 4;
1388	if (ihl < sizeof(*iph))
1389		goto out;
1390
1391	id = ntohs(iph->id);
1392	proto = iph->protocol;
1393
1394	/* Warning: after this point, iph might be no longer valid */
1395	if (unlikely(!pskb_may_pull(skb, ihl)))
1396		goto out;
1397	__skb_pull(skb, ihl);
1398
1399	encap = SKB_GSO_CB(skb)->encap_level > 0;
1400	if (encap)
1401		features &= skb->dev->hw_enc_features;
1402	SKB_GSO_CB(skb)->encap_level += ihl;
1403
1404	skb_reset_transport_header(skb);
1405
1406	segs = ERR_PTR(-EPROTONOSUPPORT);
1407
1408	if (!skb->encapsulation || encap) {
1409		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1410		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1411
1412		/* fixed ID is invalid if DF bit is not set */
1413		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1414			goto out;
1415	}
1416
1417	ops = rcu_dereference(inet_offloads[proto]);
1418	if (likely(ops && ops->callbacks.gso_segment)) {
1419		segs = ops->callbacks.gso_segment(skb, features);
1420		if (!segs)
1421			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1422	}
1423
1424	if (IS_ERR_OR_NULL(segs))
1425		goto out;
1426
1427	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1428
1429	skb = segs;
1430	do {
1431		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1432		if (udpfrag) {
1433			iph->frag_off = htons(offset >> 3);
1434			if (skb->next)
1435				iph->frag_off |= htons(IP_MF);
1436			offset += skb->len - nhoff - ihl;
1437			tot_len = skb->len - nhoff;
1438		} else if (skb_is_gso(skb)) {
1439			if (!fixedid) {
1440				iph->id = htons(id);
1441				id += skb_shinfo(skb)->gso_segs;
1442			}
1443
1444			if (gso_partial)
1445				tot_len = skb_shinfo(skb)->gso_size +
1446					  SKB_GSO_CB(skb)->data_offset +
1447					  skb->head - (unsigned char *)iph;
1448			else
1449				tot_len = skb->len - nhoff;
1450		} else {
1451			if (!fixedid)
1452				iph->id = htons(id++);
1453			tot_len = skb->len - nhoff;
1454		}
1455		iph->tot_len = htons(tot_len);
1456		ip_send_check(iph);
1457		if (encap)
1458			skb_reset_inner_headers(skb);
1459		skb->network_header = (u8 *)iph - skb->head;
1460		skb_reset_mac_len(skb);
1461	} while ((skb = skb->next));
1462
1463out:
1464	return segs;
1465}
1466
1467static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1468					netdev_features_t features)
1469{
1470	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1471		return ERR_PTR(-EINVAL);
1472
1473	return inet_gso_segment(skb, features);
1474}
1475
1476struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1477{
1478	const struct net_offload *ops;
1479	struct sk_buff *pp = NULL;
1480	const struct iphdr *iph;
1481	struct sk_buff *p;
1482	unsigned int hlen;
1483	unsigned int off;
1484	unsigned int id;
1485	int flush = 1;
1486	int proto;
1487
1488	off = skb_gro_offset(skb);
1489	hlen = off + sizeof(*iph);
1490	iph = skb_gro_header(skb, hlen, off);
1491	if (unlikely(!iph))
1492		goto out;
1493
1494	proto = iph->protocol;
1495
1496	ops = rcu_dereference(inet_offloads[proto]);
1497	if (!ops || !ops->callbacks.gro_receive)
1498		goto out;
1499
1500	if (*(u8 *)iph != 0x45)
1501		goto out;
1502
1503	if (ip_is_fragment(iph))
1504		goto out;
1505
1506	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1507		goto out;
1508
1509	NAPI_GRO_CB(skb)->proto = proto;
1510	id = ntohl(*(__be32 *)&iph->id);
1511	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1512	id >>= 16;
1513
1514	list_for_each_entry(p, head, list) {
1515		struct iphdr *iph2;
1516		u16 flush_id;
1517
1518		if (!NAPI_GRO_CB(p)->same_flow)
1519			continue;
1520
1521		iph2 = (struct iphdr *)(p->data + off);
1522		/* The above works because, with the exception of the top
1523		 * (inner most) layer, we only aggregate pkts with the same
1524		 * hdr length so all the hdrs we'll need to verify will start
1525		 * at the same offset.
1526		 */
1527		if ((iph->protocol ^ iph2->protocol) |
1528		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1529		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1530			NAPI_GRO_CB(p)->same_flow = 0;
1531			continue;
1532		}
1533
1534		/* All fields must match except length and checksum. */
1535		NAPI_GRO_CB(p)->flush |=
1536			(iph->ttl ^ iph2->ttl) |
1537			(iph->tos ^ iph2->tos) |
1538			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1539
1540		NAPI_GRO_CB(p)->flush |= flush;
1541
1542		/* We need to store of the IP ID check to be included later
1543		 * when we can verify that this packet does in fact belong
1544		 * to a given flow.
1545		 */
1546		flush_id = (u16)(id - ntohs(iph2->id));
1547
1548		/* This bit of code makes it much easier for us to identify
1549		 * the cases where we are doing atomic vs non-atomic IP ID
1550		 * checks.  Specifically an atomic check can return IP ID
1551		 * values 0 - 0xFFFF, while a non-atomic check can only
1552		 * return 0 or 0xFFFF.
1553		 */
1554		if (!NAPI_GRO_CB(p)->is_atomic ||
1555		    !(iph->frag_off & htons(IP_DF))) {
1556			flush_id ^= NAPI_GRO_CB(p)->count;
1557			flush_id = flush_id ? 0xFFFF : 0;
1558		}
1559
1560		/* If the previous IP ID value was based on an atomic
1561		 * datagram we can overwrite the value and ignore it.
1562		 */
1563		if (NAPI_GRO_CB(skb)->is_atomic)
1564			NAPI_GRO_CB(p)->flush_id = flush_id;
1565		else
1566			NAPI_GRO_CB(p)->flush_id |= flush_id;
1567	}
1568
1569	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1570	NAPI_GRO_CB(skb)->flush |= flush;
1571	skb_set_network_header(skb, off);
1572	/* The above will be needed by the transport layer if there is one
1573	 * immediately following this IP hdr.
1574	 */
1575
1576	/* Note : No need to call skb_gro_postpull_rcsum() here,
1577	 * as we already checked checksum over ipv4 header was 0
1578	 */
1579	skb_gro_pull(skb, sizeof(*iph));
1580	skb_set_transport_header(skb, skb_gro_offset(skb));
1581
1582	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1583				       ops->callbacks.gro_receive, head, skb);
1584
1585out:
1586	skb_gro_flush_final(skb, pp, flush);
1587
1588	return pp;
1589}
1590
1591static struct sk_buff *ipip_gro_receive(struct list_head *head,
1592					struct sk_buff *skb)
1593{
1594	if (NAPI_GRO_CB(skb)->encap_mark) {
1595		NAPI_GRO_CB(skb)->flush = 1;
1596		return NULL;
1597	}
1598
1599	NAPI_GRO_CB(skb)->encap_mark = 1;
1600
1601	return inet_gro_receive(head, skb);
1602}
1603
1604#define SECONDS_PER_DAY	86400
1605
1606/* inet_current_timestamp - Return IP network timestamp
1607 *
1608 * Return milliseconds since midnight in network byte order.
1609 */
1610__be32 inet_current_timestamp(void)
1611{
1612	u32 secs;
1613	u32 msecs;
1614	struct timespec64 ts;
1615
1616	ktime_get_real_ts64(&ts);
1617
1618	/* Get secs since midnight. */
1619	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1620	/* Convert to msecs. */
1621	msecs = secs * MSEC_PER_SEC;
1622	/* Convert nsec to msec. */
1623	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1624
1625	/* Convert to network byte order. */
1626	return htonl(msecs);
1627}
1628EXPORT_SYMBOL(inet_current_timestamp);
1629
1630int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1631{
1632	unsigned int family = READ_ONCE(sk->sk_family);
1633
1634	if (family == AF_INET)
1635		return ip_recv_error(sk, msg, len, addr_len);
1636#if IS_ENABLED(CONFIG_IPV6)
1637	if (family == AF_INET6)
1638		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1639#endif
1640	return -EINVAL;
1641}
1642EXPORT_SYMBOL(inet_recv_error);
1643
1644int inet_gro_complete(struct sk_buff *skb, int nhoff)
1645{
1646	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1647	const struct net_offload *ops;
1648	__be16 totlen = iph->tot_len;
1649	int proto = iph->protocol;
1650	int err = -ENOSYS;
1651
1652	if (skb->encapsulation) {
1653		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1654		skb_set_inner_network_header(skb, nhoff);
1655	}
1656
1657	iph_set_totlen(iph, skb->len - nhoff);
1658	csum_replace2(&iph->check, totlen, iph->tot_len);
1659
1660	ops = rcu_dereference(inet_offloads[proto]);
1661	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1662		goto out;
1663
1664	/* Only need to add sizeof(*iph) to get to the next hdr below
1665	 * because any hdr with option will have been flushed in
1666	 * inet_gro_receive().
1667	 */
1668	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1669			      tcp4_gro_complete, udp4_gro_complete,
1670			      skb, nhoff + sizeof(*iph));
1671
1672out:
1673	return err;
1674}
1675
1676static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1677{
1678	skb->encapsulation = 1;
1679	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1680	return inet_gro_complete(skb, nhoff);
1681}
1682
1683int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1684			 unsigned short type, unsigned char protocol,
1685			 struct net *net)
1686{
1687	struct socket *sock;
1688	int rc = sock_create_kern(net, family, type, protocol, &sock);
1689
1690	if (rc == 0) {
1691		*sk = sock->sk;
1692		(*sk)->sk_allocation = GFP_ATOMIC;
1693		(*sk)->sk_use_task_frag = false;
1694		/*
1695		 * Unhash it so that IP input processing does not even see it,
1696		 * we do not wish this socket to see incoming packets.
1697		 */
1698		(*sk)->sk_prot->unhash(*sk);
1699	}
1700	return rc;
1701}
1702EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1703
1704unsigned long snmp_fold_field(void __percpu *mib, int offt)
1705{
1706	unsigned long res = 0;
1707	int i;
1708
1709	for_each_possible_cpu(i)
1710		res += snmp_get_cpu_field(mib, i, offt);
1711	return res;
1712}
1713EXPORT_SYMBOL_GPL(snmp_fold_field);
1714
1715#if BITS_PER_LONG==32
1716
1717u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1718			 size_t syncp_offset)
1719{
1720	void *bhptr;
1721	struct u64_stats_sync *syncp;
1722	u64 v;
1723	unsigned int start;
1724
1725	bhptr = per_cpu_ptr(mib, cpu);
1726	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1727	do {
1728		start = u64_stats_fetch_begin(syncp);
1729		v = *(((u64 *)bhptr) + offt);
1730	} while (u64_stats_fetch_retry(syncp, start));
1731
1732	return v;
1733}
1734EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1735
1736u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1737{
1738	u64 res = 0;
1739	int cpu;
1740
1741	for_each_possible_cpu(cpu) {
1742		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1743	}
1744	return res;
1745}
1746EXPORT_SYMBOL_GPL(snmp_fold_field64);
1747#endif
1748
1749#ifdef CONFIG_IP_MULTICAST
1750static const struct net_protocol igmp_protocol = {
1751	.handler =	igmp_rcv,
1752};
1753#endif
1754
1755static const struct net_protocol icmp_protocol = {
1756	.handler =	icmp_rcv,
1757	.err_handler =	icmp_err,
1758	.no_policy =	1,
1759};
1760
1761static __net_init int ipv4_mib_init_net(struct net *net)
1762{
1763	int i;
1764
1765	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1766	if (!net->mib.tcp_statistics)
1767		goto err_tcp_mib;
1768	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1769	if (!net->mib.ip_statistics)
1770		goto err_ip_mib;
1771
1772	for_each_possible_cpu(i) {
1773		struct ipstats_mib *af_inet_stats;
1774		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1775		u64_stats_init(&af_inet_stats->syncp);
1776	}
1777
1778	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1779	if (!net->mib.net_statistics)
1780		goto err_net_mib;
1781	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1782	if (!net->mib.udp_statistics)
1783		goto err_udp_mib;
1784	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1785	if (!net->mib.udplite_statistics)
1786		goto err_udplite_mib;
1787	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1788	if (!net->mib.icmp_statistics)
1789		goto err_icmp_mib;
1790	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1791					      GFP_KERNEL);
1792	if (!net->mib.icmpmsg_statistics)
1793		goto err_icmpmsg_mib;
1794
1795	tcp_mib_init(net);
1796	return 0;
1797
1798err_icmpmsg_mib:
1799	free_percpu(net->mib.icmp_statistics);
1800err_icmp_mib:
1801	free_percpu(net->mib.udplite_statistics);
1802err_udplite_mib:
1803	free_percpu(net->mib.udp_statistics);
1804err_udp_mib:
1805	free_percpu(net->mib.net_statistics);
1806err_net_mib:
1807	free_percpu(net->mib.ip_statistics);
1808err_ip_mib:
1809	free_percpu(net->mib.tcp_statistics);
1810err_tcp_mib:
1811	return -ENOMEM;
1812}
1813
1814static __net_exit void ipv4_mib_exit_net(struct net *net)
1815{
1816	kfree(net->mib.icmpmsg_statistics);
1817	free_percpu(net->mib.icmp_statistics);
1818	free_percpu(net->mib.udplite_statistics);
1819	free_percpu(net->mib.udp_statistics);
1820	free_percpu(net->mib.net_statistics);
1821	free_percpu(net->mib.ip_statistics);
1822	free_percpu(net->mib.tcp_statistics);
1823#ifdef CONFIG_MPTCP
1824	/* allocated on demand, see mptcp_init_sock() */
1825	free_percpu(net->mib.mptcp_statistics);
1826#endif
1827}
1828
1829static __net_initdata struct pernet_operations ipv4_mib_ops = {
1830	.init = ipv4_mib_init_net,
1831	.exit = ipv4_mib_exit_net,
1832};
1833
1834static int __init init_ipv4_mibs(void)
1835{
1836	return register_pernet_subsys(&ipv4_mib_ops);
1837}
1838
1839static __net_init int inet_init_net(struct net *net)
1840{
1841	/*
1842	 * Set defaults for local port range
1843	 */
1844	net->ipv4.ip_local_ports.range = 60999u << 16 | 32768u;
1845
1846	seqlock_init(&net->ipv4.ping_group_range.lock);
1847	/*
1848	 * Sane defaults - nobody may create ping sockets.
1849	 * Boot scripts should set this to distro-specific group.
1850	 */
1851	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1852	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1853
1854	/* Default values for sysctl-controlled parameters.
1855	 * We set them here, in case sysctl is not compiled.
1856	 */
1857	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1858	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1859	net->ipv4.sysctl_ip_dynaddr = 0;
1860	net->ipv4.sysctl_ip_early_demux = 1;
1861	net->ipv4.sysctl_udp_early_demux = 1;
1862	net->ipv4.sysctl_tcp_early_demux = 1;
1863	net->ipv4.sysctl_nexthop_compat_mode = 1;
1864#ifdef CONFIG_SYSCTL
1865	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1866#endif
1867
1868	/* Some igmp sysctl, whose values are always used */
1869	net->ipv4.sysctl_igmp_max_memberships = 20;
1870	net->ipv4.sysctl_igmp_max_msf = 10;
1871	/* IGMP reports for link-local multicast groups are enabled by default */
1872	net->ipv4.sysctl_igmp_llm_reports = 1;
1873	net->ipv4.sysctl_igmp_qrv = 2;
1874
1875	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1876
1877	return 0;
1878}
1879
1880static __net_initdata struct pernet_operations af_inet_ops = {
1881	.init = inet_init_net,
1882};
1883
1884static int __init init_inet_pernet_ops(void)
1885{
1886	return register_pernet_subsys(&af_inet_ops);
1887}
1888
1889static int ipv4_proc_init(void);
1890
1891/*
1892 *	IP protocol layer initialiser
1893 */
1894
1895
1896static const struct net_offload ipip_offload = {
1897	.callbacks = {
1898		.gso_segment	= ipip_gso_segment,
1899		.gro_receive	= ipip_gro_receive,
1900		.gro_complete	= ipip_gro_complete,
1901	},
1902};
1903
1904static int __init ipip_offload_init(void)
1905{
1906	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1907}
1908
1909static int __init ipv4_offload_init(void)
1910{
1911	/*
1912	 * Add offloads
1913	 */
1914	if (udpv4_offload_init() < 0)
1915		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1916	if (tcpv4_offload_init() < 0)
1917		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1918	if (ipip_offload_init() < 0)
1919		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1920
1921	net_hotdata.ip_packet_offload = (struct packet_offload) {
1922		.type = cpu_to_be16(ETH_P_IP),
1923		.callbacks = {
1924			.gso_segment = inet_gso_segment,
1925			.gro_receive = inet_gro_receive,
1926			.gro_complete = inet_gro_complete,
1927		},
1928	};
1929	dev_add_offload(&net_hotdata.ip_packet_offload);
1930	return 0;
1931}
1932
1933fs_initcall(ipv4_offload_init);
1934
1935static struct packet_type ip_packet_type __read_mostly = {
1936	.type = cpu_to_be16(ETH_P_IP),
1937	.func = ip_rcv,
1938	.list_func = ip_list_rcv,
1939};
1940
1941static int __init inet_init(void)
1942{
1943	struct inet_protosw *q;
1944	struct list_head *r;
1945	int rc;
1946
1947	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1948
1949	raw_hashinfo_init(&raw_v4_hashinfo);
1950
1951	rc = proto_register(&tcp_prot, 1);
1952	if (rc)
1953		goto out;
1954
1955	rc = proto_register(&udp_prot, 1);
1956	if (rc)
1957		goto out_unregister_tcp_proto;
1958
1959	rc = proto_register(&raw_prot, 1);
1960	if (rc)
1961		goto out_unregister_udp_proto;
1962
1963	rc = proto_register(&ping_prot, 1);
1964	if (rc)
1965		goto out_unregister_raw_proto;
1966
1967	/*
1968	 *	Tell SOCKET that we are alive...
1969	 */
1970
1971	(void)sock_register(&inet_family_ops);
1972
1973#ifdef CONFIG_SYSCTL
1974	ip_static_sysctl_init();
1975#endif
1976
1977	/*
1978	 *	Add all the base protocols.
1979	 */
1980
1981	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1982		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1983
1984	net_hotdata.udp_protocol = (struct net_protocol) {
1985		.handler =	udp_rcv,
1986		.err_handler =	udp_err,
1987		.no_policy =	1,
1988	};
1989	if (inet_add_protocol(&net_hotdata.udp_protocol, IPPROTO_UDP) < 0)
1990		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1991
1992	net_hotdata.tcp_protocol = (struct net_protocol) {
1993		.handler	=	tcp_v4_rcv,
1994		.err_handler	=	tcp_v4_err,
1995		.no_policy	=	1,
1996		.icmp_strict_tag_validation = 1,
1997	};
1998	if (inet_add_protocol(&net_hotdata.tcp_protocol, IPPROTO_TCP) < 0)
1999		pr_crit("%s: Cannot add TCP protocol\n", __func__);
2000#ifdef CONFIG_IP_MULTICAST
2001	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
2002		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2003#endif
2004
2005	/* Register the socket-side information for inet_create. */
2006	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2007		INIT_LIST_HEAD(r);
2008
2009	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2010		inet_register_protosw(q);
2011
2012	/*
2013	 *	Set the ARP module up
2014	 */
2015
2016	arp_init();
2017
2018	/*
2019	 *	Set the IP module up
2020	 */
2021
2022	ip_init();
2023
2024	/* Initialise per-cpu ipv4 mibs */
2025	if (init_ipv4_mibs())
2026		panic("%s: Cannot init ipv4 mibs\n", __func__);
2027
2028	/* Setup TCP slab cache for open requests. */
2029	tcp_init();
2030
2031	/* Setup UDP memory threshold */
2032	udp_init();
2033
2034	/* Add UDP-Lite (RFC 3828) */
2035	udplite4_register();
2036
2037	raw_init();
2038
2039	ping_init();
2040
2041	/*
2042	 *	Set the ICMP layer up
2043	 */
2044
2045	if (icmp_init() < 0)
2046		panic("Failed to create the ICMP control socket.\n");
2047
2048	/*
2049	 *	Initialise the multicast router
2050	 */
2051#if defined(CONFIG_IP_MROUTE)
2052	if (ip_mr_init())
2053		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2054#endif
2055
2056	if (init_inet_pernet_ops())
2057		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2058
2059	ipv4_proc_init();
2060
2061	ipfrag_init();
2062
2063	dev_add_pack(&ip_packet_type);
2064
2065	ip_tunnel_core_init();
2066
2067	rc = 0;
2068out:
2069	return rc;
2070out_unregister_raw_proto:
2071	proto_unregister(&raw_prot);
2072out_unregister_udp_proto:
2073	proto_unregister(&udp_prot);
2074out_unregister_tcp_proto:
2075	proto_unregister(&tcp_prot);
2076	goto out;
2077}
2078
2079fs_initcall(inet_init);
2080
2081/* ------------------------------------------------------------------------ */
2082
2083#ifdef CONFIG_PROC_FS
2084static int __init ipv4_proc_init(void)
2085{
2086	int rc = 0;
2087
2088	if (raw_proc_init())
2089		goto out_raw;
2090	if (tcp4_proc_init())
2091		goto out_tcp;
2092	if (udp4_proc_init())
2093		goto out_udp;
2094	if (ping_proc_init())
2095		goto out_ping;
2096	if (ip_misc_proc_init())
2097		goto out_misc;
2098out:
2099	return rc;
2100out_misc:
2101	ping_proc_exit();
2102out_ping:
2103	udp4_proc_exit();
2104out_udp:
2105	tcp4_proc_exit();
2106out_tcp:
2107	raw_proc_exit();
2108out_raw:
2109	rc = -ENOMEM;
2110	goto out;
2111}
2112
2113#else /* CONFIG_PROC_FS */
2114static int __init ipv4_proc_init(void)
2115{
2116	return 0;
2117}
2118#endif /* CONFIG_PROC_FS */
2119