xref: /openbmc/linux/net/ipv4/af_inet.c (revision 6db6b729)
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 
123 #include <trace/events/sock.h>
124 
125 /* The inetsw table contains everything that inet_create needs to
126  * build a new socket.
127  */
128 static struct list_head inetsw[SOCK_MAX];
129 static DEFINE_SPINLOCK(inetsw_lock);
130 
131 /* New destruction routine */
132 
133 void inet_sock_destruct(struct sock *sk)
134 {
135 	struct inet_sock *inet = inet_sk(sk);
136 
137 	__skb_queue_purge(&sk->sk_receive_queue);
138 	__skb_queue_purge(&sk->sk_error_queue);
139 
140 	sk_mem_reclaim_final(sk);
141 
142 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
143 		pr_err("Attempt to release TCP socket in state %d %p\n",
144 		       sk->sk_state, sk);
145 		return;
146 	}
147 	if (!sock_flag(sk, SOCK_DEAD)) {
148 		pr_err("Attempt to release alive inet socket %p\n", sk);
149 		return;
150 	}
151 
152 	WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));
153 	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
154 	WARN_ON_ONCE(sk->sk_wmem_queued);
155 	WARN_ON_ONCE(sk_forward_alloc_get(sk));
156 
157 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
158 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
159 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
160 }
161 EXPORT_SYMBOL(inet_sock_destruct);
162 
163 /*
164  *	The routines beyond this point handle the behaviour of an AF_INET
165  *	socket object. Mostly it punts to the subprotocols of IP to do
166  *	the work.
167  */
168 
169 /*
170  *	Automatically bind an unbound socket.
171  */
172 
173 static int inet_autobind(struct sock *sk)
174 {
175 	struct inet_sock *inet;
176 	/* We may need to bind the socket. */
177 	lock_sock(sk);
178 	inet = inet_sk(sk);
179 	if (!inet->inet_num) {
180 		if (sk->sk_prot->get_port(sk, 0)) {
181 			release_sock(sk);
182 			return -EAGAIN;
183 		}
184 		inet->inet_sport = htons(inet->inet_num);
185 	}
186 	release_sock(sk);
187 	return 0;
188 }
189 
190 int __inet_listen_sk(struct sock *sk, int backlog)
191 {
192 	unsigned char old_state = sk->sk_state;
193 	int err, tcp_fastopen;
194 
195 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
196 		return -EINVAL;
197 
198 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
199 	/* Really, if the socket is already in listen state
200 	 * we can only allow the backlog to be adjusted.
201 	 */
202 	if (old_state != TCP_LISTEN) {
203 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
204 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
205 		 * Also fastopen backlog may already been set via the option
206 		 * because the socket was in TCP_LISTEN state previously but
207 		 * was shutdown() rather than close().
208 		 */
209 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
210 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
211 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
212 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
213 			fastopen_queue_tune(sk, backlog);
214 			tcp_fastopen_init_key_once(sock_net(sk));
215 		}
216 
217 		err = inet_csk_listen_start(sk);
218 		if (err)
219 			return err;
220 
221 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
222 	}
223 	return 0;
224 }
225 
226 /*
227  *	Move a socket into listening state.
228  */
229 int inet_listen(struct socket *sock, int backlog)
230 {
231 	struct sock *sk = sock->sk;
232 	int err = -EINVAL;
233 
234 	lock_sock(sk);
235 
236 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
237 		goto out;
238 
239 	err = __inet_listen_sk(sk, backlog);
240 
241 out:
242 	release_sock(sk);
243 	return err;
244 }
245 EXPORT_SYMBOL(inet_listen);
246 
247 /*
248  *	Create an inet socket.
249  */
250 
251 static int inet_create(struct net *net, struct socket *sock, int protocol,
252 		       int kern)
253 {
254 	struct sock *sk;
255 	struct inet_protosw *answer;
256 	struct inet_sock *inet;
257 	struct proto *answer_prot;
258 	unsigned char answer_flags;
259 	int try_loading_module = 0;
260 	int err;
261 
262 	if (protocol < 0 || protocol >= IPPROTO_MAX)
263 		return -EINVAL;
264 
265 	sock->state = SS_UNCONNECTED;
266 
267 	/* Look for the requested type/protocol pair. */
268 lookup_protocol:
269 	err = -ESOCKTNOSUPPORT;
270 	rcu_read_lock();
271 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
272 
273 		err = 0;
274 		/* Check the non-wild match. */
275 		if (protocol == answer->protocol) {
276 			if (protocol != IPPROTO_IP)
277 				break;
278 		} else {
279 			/* Check for the two wild cases. */
280 			if (IPPROTO_IP == protocol) {
281 				protocol = answer->protocol;
282 				break;
283 			}
284 			if (IPPROTO_IP == answer->protocol)
285 				break;
286 		}
287 		err = -EPROTONOSUPPORT;
288 	}
289 
290 	if (unlikely(err)) {
291 		if (try_loading_module < 2) {
292 			rcu_read_unlock();
293 			/*
294 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
295 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
296 			 */
297 			if (++try_loading_module == 1)
298 				request_module("net-pf-%d-proto-%d-type-%d",
299 					       PF_INET, protocol, sock->type);
300 			/*
301 			 * Fall back to generic, e.g. net-pf-2-proto-132
302 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
303 			 */
304 			else
305 				request_module("net-pf-%d-proto-%d",
306 					       PF_INET, protocol);
307 			goto lookup_protocol;
308 		} else
309 			goto out_rcu_unlock;
310 	}
311 
312 	err = -EPERM;
313 	if (sock->type == SOCK_RAW && !kern &&
314 	    !ns_capable(net->user_ns, CAP_NET_RAW))
315 		goto out_rcu_unlock;
316 
317 	sock->ops = answer->ops;
318 	answer_prot = answer->prot;
319 	answer_flags = answer->flags;
320 	rcu_read_unlock();
321 
322 	WARN_ON(!answer_prot->slab);
323 
324 	err = -ENOMEM;
325 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
326 	if (!sk)
327 		goto out;
328 
329 	err = 0;
330 	if (INET_PROTOSW_REUSE & answer_flags)
331 		sk->sk_reuse = SK_CAN_REUSE;
332 
333 	inet = inet_sk(sk);
334 	inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
335 
336 	inet_clear_bit(NODEFRAG, sk);
337 
338 	if (SOCK_RAW == sock->type) {
339 		inet->inet_num = protocol;
340 		if (IPPROTO_RAW == protocol)
341 			inet_set_bit(HDRINCL, sk);
342 	}
343 
344 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
345 		inet->pmtudisc = IP_PMTUDISC_DONT;
346 	else
347 		inet->pmtudisc = IP_PMTUDISC_WANT;
348 
349 	atomic_set(&inet->inet_id, 0);
350 
351 	sock_init_data(sock, sk);
352 
353 	sk->sk_destruct	   = inet_sock_destruct;
354 	sk->sk_protocol	   = protocol;
355 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
356 	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
357 
358 	inet->uc_ttl	= -1;
359 	inet_set_bit(MC_LOOP, sk);
360 	inet->mc_ttl	= 1;
361 	inet_set_bit(MC_ALL, sk);
362 	inet->mc_index	= 0;
363 	inet->mc_list	= NULL;
364 	inet->rcv_tos	= 0;
365 
366 	if (inet->inet_num) {
367 		/* It assumes that any protocol which allows
368 		 * the user to assign a number at socket
369 		 * creation time automatically
370 		 * shares.
371 		 */
372 		inet->inet_sport = htons(inet->inet_num);
373 		/* Add to protocol hash chains. */
374 		err = sk->sk_prot->hash(sk);
375 		if (err) {
376 			sk_common_release(sk);
377 			goto out;
378 		}
379 	}
380 
381 	if (sk->sk_prot->init) {
382 		err = sk->sk_prot->init(sk);
383 		if (err) {
384 			sk_common_release(sk);
385 			goto out;
386 		}
387 	}
388 
389 	if (!kern) {
390 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
391 		if (err) {
392 			sk_common_release(sk);
393 			goto out;
394 		}
395 	}
396 out:
397 	return err;
398 out_rcu_unlock:
399 	rcu_read_unlock();
400 	goto out;
401 }
402 
403 
404 /*
405  *	The peer socket should always be NULL (or else). When we call this
406  *	function we are destroying the object and from then on nobody
407  *	should refer to it.
408  */
409 int inet_release(struct socket *sock)
410 {
411 	struct sock *sk = sock->sk;
412 
413 	if (sk) {
414 		long timeout;
415 
416 		if (!sk->sk_kern_sock)
417 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
418 
419 		/* Applications forget to leave groups before exiting */
420 		ip_mc_drop_socket(sk);
421 
422 		/* If linger is set, we don't return until the close
423 		 * is complete.  Otherwise we return immediately. The
424 		 * actually closing is done the same either way.
425 		 *
426 		 * If the close is due to the process exiting, we never
427 		 * linger..
428 		 */
429 		timeout = 0;
430 		if (sock_flag(sk, SOCK_LINGER) &&
431 		    !(current->flags & PF_EXITING))
432 			timeout = sk->sk_lingertime;
433 		sk->sk_prot->close(sk, timeout);
434 		sock->sk = NULL;
435 	}
436 	return 0;
437 }
438 EXPORT_SYMBOL(inet_release);
439 
440 int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
441 {
442 	u32 flags = BIND_WITH_LOCK;
443 	int err;
444 
445 	/* If the socket has its own bind function then use it. (RAW) */
446 	if (sk->sk_prot->bind) {
447 		return sk->sk_prot->bind(sk, uaddr, addr_len);
448 	}
449 	if (addr_len < sizeof(struct sockaddr_in))
450 		return -EINVAL;
451 
452 	/* BPF prog is run before any checks are done so that if the prog
453 	 * changes context in a wrong way it will be caught.
454 	 */
455 	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr,
456 						 CGROUP_INET4_BIND, &flags);
457 	if (err)
458 		return err;
459 
460 	return __inet_bind(sk, uaddr, addr_len, flags);
461 }
462 
463 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
464 {
465 	return inet_bind_sk(sock->sk, uaddr, addr_len);
466 }
467 EXPORT_SYMBOL(inet_bind);
468 
469 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
470 		u32 flags)
471 {
472 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
473 	struct inet_sock *inet = inet_sk(sk);
474 	struct net *net = sock_net(sk);
475 	unsigned short snum;
476 	int chk_addr_ret;
477 	u32 tb_id = RT_TABLE_LOCAL;
478 	int err;
479 
480 	if (addr->sin_family != AF_INET) {
481 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
482 		 * only if s_addr is INADDR_ANY.
483 		 */
484 		err = -EAFNOSUPPORT;
485 		if (addr->sin_family != AF_UNSPEC ||
486 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
487 			goto out;
488 	}
489 
490 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
491 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
492 
493 	/* Not specified by any standard per-se, however it breaks too
494 	 * many applications when removed.  It is unfortunate since
495 	 * allowing applications to make a non-local bind solves
496 	 * several problems with systems using dynamic addressing.
497 	 * (ie. your servers still start up even if your ISDN link
498 	 *  is temporarily down)
499 	 */
500 	err = -EADDRNOTAVAIL;
501 	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
502 	                                 chk_addr_ret))
503 		goto out;
504 
505 	snum = ntohs(addr->sin_port);
506 	err = -EACCES;
507 	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
508 	    snum && inet_port_requires_bind_service(net, snum) &&
509 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
510 		goto out;
511 
512 	/*      We keep a pair of addresses. rcv_saddr is the one
513 	 *      used by hash lookups, and saddr is used for transmit.
514 	 *
515 	 *      In the BSD API these are the same except where it
516 	 *      would be illegal to use them (multicast/broadcast) in
517 	 *      which case the sending device address is used.
518 	 */
519 	if (flags & BIND_WITH_LOCK)
520 		lock_sock(sk);
521 
522 	/* Check these errors (active socket, double bind). */
523 	err = -EINVAL;
524 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
525 		goto out_release_sock;
526 
527 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
528 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
529 		inet->inet_saddr = 0;  /* Use device */
530 
531 	/* Make sure we are allowed to bind here. */
532 	if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
533 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
534 		err = sk->sk_prot->get_port(sk, snum);
535 		if (err) {
536 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
537 			goto out_release_sock;
538 		}
539 		if (!(flags & BIND_FROM_BPF)) {
540 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
541 			if (err) {
542 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
543 				if (sk->sk_prot->put_port)
544 					sk->sk_prot->put_port(sk);
545 				goto out_release_sock;
546 			}
547 		}
548 	}
549 
550 	if (inet->inet_rcv_saddr)
551 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
552 	if (snum)
553 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
554 	inet->inet_sport = htons(inet->inet_num);
555 	inet->inet_daddr = 0;
556 	inet->inet_dport = 0;
557 	sk_dst_reset(sk);
558 	err = 0;
559 out_release_sock:
560 	if (flags & BIND_WITH_LOCK)
561 		release_sock(sk);
562 out:
563 	return err;
564 }
565 
566 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
567 		       int addr_len, int flags)
568 {
569 	struct sock *sk = sock->sk;
570 	const struct proto *prot;
571 	int err;
572 
573 	if (addr_len < sizeof(uaddr->sa_family))
574 		return -EINVAL;
575 
576 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
577 	prot = READ_ONCE(sk->sk_prot);
578 
579 	if (uaddr->sa_family == AF_UNSPEC)
580 		return prot->disconnect(sk, flags);
581 
582 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
583 		err = prot->pre_connect(sk, uaddr, addr_len);
584 		if (err)
585 			return err;
586 	}
587 
588 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
589 		return -EAGAIN;
590 	return prot->connect(sk, uaddr, addr_len);
591 }
592 EXPORT_SYMBOL(inet_dgram_connect);
593 
594 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
595 {
596 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
597 
598 	add_wait_queue(sk_sleep(sk), &wait);
599 	sk->sk_write_pending += writebias;
600 
601 	/* Basic assumption: if someone sets sk->sk_err, he _must_
602 	 * change state of the socket from TCP_SYN_*.
603 	 * Connect() does not allow to get error notifications
604 	 * without closing the socket.
605 	 */
606 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
607 		release_sock(sk);
608 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
609 		lock_sock(sk);
610 		if (signal_pending(current) || !timeo)
611 			break;
612 	}
613 	remove_wait_queue(sk_sleep(sk), &wait);
614 	sk->sk_write_pending -= writebias;
615 	return timeo;
616 }
617 
618 /*
619  *	Connect to a remote host. There is regrettably still a little
620  *	TCP 'magic' in here.
621  */
622 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
623 			  int addr_len, int flags, int is_sendmsg)
624 {
625 	struct sock *sk = sock->sk;
626 	int err;
627 	long timeo;
628 
629 	/*
630 	 * uaddr can be NULL and addr_len can be 0 if:
631 	 * sk is a TCP fastopen active socket and
632 	 * TCP_FASTOPEN_CONNECT sockopt is set and
633 	 * we already have a valid cookie for this socket.
634 	 * In this case, user can call write() after connect().
635 	 * write() will invoke tcp_sendmsg_fastopen() which calls
636 	 * __inet_stream_connect().
637 	 */
638 	if (uaddr) {
639 		if (addr_len < sizeof(uaddr->sa_family))
640 			return -EINVAL;
641 
642 		if (uaddr->sa_family == AF_UNSPEC) {
643 			sk->sk_disconnects++;
644 			err = sk->sk_prot->disconnect(sk, flags);
645 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
646 			goto out;
647 		}
648 	}
649 
650 	switch (sock->state) {
651 	default:
652 		err = -EINVAL;
653 		goto out;
654 	case SS_CONNECTED:
655 		err = -EISCONN;
656 		goto out;
657 	case SS_CONNECTING:
658 		if (inet_test_bit(DEFER_CONNECT, sk))
659 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
660 		else
661 			err = -EALREADY;
662 		/* Fall out of switch with err, set for this state */
663 		break;
664 	case SS_UNCONNECTED:
665 		err = -EISCONN;
666 		if (sk->sk_state != TCP_CLOSE)
667 			goto out;
668 
669 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
670 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
671 			if (err)
672 				goto out;
673 		}
674 
675 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
676 		if (err < 0)
677 			goto out;
678 
679 		sock->state = SS_CONNECTING;
680 
681 		if (!err && inet_test_bit(DEFER_CONNECT, sk))
682 			goto out;
683 
684 		/* Just entered SS_CONNECTING state; the only
685 		 * difference is that return value in non-blocking
686 		 * case is EINPROGRESS, rather than EALREADY.
687 		 */
688 		err = -EINPROGRESS;
689 		break;
690 	}
691 
692 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
693 
694 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
695 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
696 				tcp_sk(sk)->fastopen_req &&
697 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
698 		int dis = sk->sk_disconnects;
699 
700 		/* Error code is set above */
701 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
702 			goto out;
703 
704 		err = sock_intr_errno(timeo);
705 		if (signal_pending(current))
706 			goto out;
707 
708 		if (dis != sk->sk_disconnects) {
709 			err = -EPIPE;
710 			goto out;
711 		}
712 	}
713 
714 	/* Connection was closed by RST, timeout, ICMP error
715 	 * or another process disconnected us.
716 	 */
717 	if (sk->sk_state == TCP_CLOSE)
718 		goto sock_error;
719 
720 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
721 	 * and error was received after socket entered established state.
722 	 * Hence, it is handled normally after connect() return successfully.
723 	 */
724 
725 	sock->state = SS_CONNECTED;
726 	err = 0;
727 out:
728 	return err;
729 
730 sock_error:
731 	err = sock_error(sk) ? : -ECONNABORTED;
732 	sock->state = SS_UNCONNECTED;
733 	sk->sk_disconnects++;
734 	if (sk->sk_prot->disconnect(sk, flags))
735 		sock->state = SS_DISCONNECTING;
736 	goto out;
737 }
738 EXPORT_SYMBOL(__inet_stream_connect);
739 
740 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
741 			int addr_len, int flags)
742 {
743 	int err;
744 
745 	lock_sock(sock->sk);
746 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
747 	release_sock(sock->sk);
748 	return err;
749 }
750 EXPORT_SYMBOL(inet_stream_connect);
751 
752 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
753 {
754 	sock_rps_record_flow(newsk);
755 	WARN_ON(!((1 << newsk->sk_state) &
756 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
757 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
758 
759 	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
760 		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
761 	sock_graft(newsk, newsock);
762 
763 	newsock->state = SS_CONNECTED;
764 }
765 
766 /*
767  *	Accept a pending connection. The TCP layer now gives BSD semantics.
768  */
769 
770 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
771 		bool kern)
772 {
773 	struct sock *sk1 = sock->sk, *sk2;
774 	int err = -EINVAL;
775 
776 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
777 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
778 	if (!sk2)
779 		return err;
780 
781 	lock_sock(sk2);
782 	__inet_accept(sock, newsock, sk2);
783 	release_sock(sk2);
784 	return 0;
785 }
786 EXPORT_SYMBOL(inet_accept);
787 
788 /*
789  *	This does both peername and sockname.
790  */
791 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
792 		 int peer)
793 {
794 	struct sock *sk		= sock->sk;
795 	struct inet_sock *inet	= inet_sk(sk);
796 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
797 
798 	sin->sin_family = AF_INET;
799 	lock_sock(sk);
800 	if (peer) {
801 		if (!inet->inet_dport ||
802 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
803 		     peer == 1)) {
804 			release_sock(sk);
805 			return -ENOTCONN;
806 		}
807 		sin->sin_port = inet->inet_dport;
808 		sin->sin_addr.s_addr = inet->inet_daddr;
809 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
810 				       CGROUP_INET4_GETPEERNAME);
811 	} else {
812 		__be32 addr = inet->inet_rcv_saddr;
813 		if (!addr)
814 			addr = inet->inet_saddr;
815 		sin->sin_port = inet->inet_sport;
816 		sin->sin_addr.s_addr = addr;
817 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
818 				       CGROUP_INET4_GETSOCKNAME);
819 	}
820 	release_sock(sk);
821 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
822 	return sizeof(*sin);
823 }
824 EXPORT_SYMBOL(inet_getname);
825 
826 int inet_send_prepare(struct sock *sk)
827 {
828 	sock_rps_record_flow(sk);
829 
830 	/* We may need to bind the socket. */
831 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
832 	    inet_autobind(sk))
833 		return -EAGAIN;
834 
835 	return 0;
836 }
837 EXPORT_SYMBOL_GPL(inet_send_prepare);
838 
839 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
840 {
841 	struct sock *sk = sock->sk;
842 
843 	if (unlikely(inet_send_prepare(sk)))
844 		return -EAGAIN;
845 
846 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
847 			       sk, msg, size);
848 }
849 EXPORT_SYMBOL(inet_sendmsg);
850 
851 void inet_splice_eof(struct socket *sock)
852 {
853 	const struct proto *prot;
854 	struct sock *sk = sock->sk;
855 
856 	if (unlikely(inet_send_prepare(sk)))
857 		return;
858 
859 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
860 	prot = READ_ONCE(sk->sk_prot);
861 	if (prot->splice_eof)
862 		prot->splice_eof(sock);
863 }
864 EXPORT_SYMBOL_GPL(inet_splice_eof);
865 
866 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
867 					  size_t, int, int *));
868 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
869 		 int flags)
870 {
871 	struct sock *sk = sock->sk;
872 	int addr_len = 0;
873 	int err;
874 
875 	if (likely(!(flags & MSG_ERRQUEUE)))
876 		sock_rps_record_flow(sk);
877 
878 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
879 			      sk, msg, size, flags, &addr_len);
880 	if (err >= 0)
881 		msg->msg_namelen = addr_len;
882 	return err;
883 }
884 EXPORT_SYMBOL(inet_recvmsg);
885 
886 int inet_shutdown(struct socket *sock, int how)
887 {
888 	struct sock *sk = sock->sk;
889 	int err = 0;
890 
891 	/* This should really check to make sure
892 	 * the socket is a TCP socket. (WHY AC...)
893 	 */
894 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
895 		       1->2 bit 2 snds.
896 		       2->3 */
897 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
898 		return -EINVAL;
899 
900 	lock_sock(sk);
901 	if (sock->state == SS_CONNECTING) {
902 		if ((1 << sk->sk_state) &
903 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
904 			sock->state = SS_DISCONNECTING;
905 		else
906 			sock->state = SS_CONNECTED;
907 	}
908 
909 	switch (sk->sk_state) {
910 	case TCP_CLOSE:
911 		err = -ENOTCONN;
912 		/* Hack to wake up other listeners, who can poll for
913 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
914 		fallthrough;
915 	default:
916 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
917 		if (sk->sk_prot->shutdown)
918 			sk->sk_prot->shutdown(sk, how);
919 		break;
920 
921 	/* Remaining two branches are temporary solution for missing
922 	 * close() in multithreaded environment. It is _not_ a good idea,
923 	 * but we have no choice until close() is repaired at VFS level.
924 	 */
925 	case TCP_LISTEN:
926 		if (!(how & RCV_SHUTDOWN))
927 			break;
928 		fallthrough;
929 	case TCP_SYN_SENT:
930 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
931 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
932 		break;
933 	}
934 
935 	/* Wake up anyone sleeping in poll. */
936 	sk->sk_state_change(sk);
937 	release_sock(sk);
938 	return err;
939 }
940 EXPORT_SYMBOL(inet_shutdown);
941 
942 /*
943  *	ioctl() calls you can issue on an INET socket. Most of these are
944  *	device configuration and stuff and very rarely used. Some ioctls
945  *	pass on to the socket itself.
946  *
947  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
948  *	loads the devconfigure module does its configuring and unloads it.
949  *	There's a good 20K of config code hanging around the kernel.
950  */
951 
952 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
953 {
954 	struct sock *sk = sock->sk;
955 	int err = 0;
956 	struct net *net = sock_net(sk);
957 	void __user *p = (void __user *)arg;
958 	struct ifreq ifr;
959 	struct rtentry rt;
960 
961 	switch (cmd) {
962 	case SIOCADDRT:
963 	case SIOCDELRT:
964 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
965 			return -EFAULT;
966 		err = ip_rt_ioctl(net, cmd, &rt);
967 		break;
968 	case SIOCRTMSG:
969 		err = -EINVAL;
970 		break;
971 	case SIOCDARP:
972 	case SIOCGARP:
973 	case SIOCSARP:
974 		err = arp_ioctl(net, cmd, (void __user *)arg);
975 		break;
976 	case SIOCGIFADDR:
977 	case SIOCGIFBRDADDR:
978 	case SIOCGIFNETMASK:
979 	case SIOCGIFDSTADDR:
980 	case SIOCGIFPFLAGS:
981 		if (get_user_ifreq(&ifr, NULL, p))
982 			return -EFAULT;
983 		err = devinet_ioctl(net, cmd, &ifr);
984 		if (!err && put_user_ifreq(&ifr, p))
985 			err = -EFAULT;
986 		break;
987 
988 	case SIOCSIFADDR:
989 	case SIOCSIFBRDADDR:
990 	case SIOCSIFNETMASK:
991 	case SIOCSIFDSTADDR:
992 	case SIOCSIFPFLAGS:
993 	case SIOCSIFFLAGS:
994 		if (get_user_ifreq(&ifr, NULL, p))
995 			return -EFAULT;
996 		err = devinet_ioctl(net, cmd, &ifr);
997 		break;
998 	default:
999 		if (sk->sk_prot->ioctl)
1000 			err = sk_ioctl(sk, cmd, (void __user *)arg);
1001 		else
1002 			err = -ENOIOCTLCMD;
1003 		break;
1004 	}
1005 	return err;
1006 }
1007 EXPORT_SYMBOL(inet_ioctl);
1008 
1009 #ifdef CONFIG_COMPAT
1010 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1011 		struct compat_rtentry __user *ur)
1012 {
1013 	compat_uptr_t rtdev;
1014 	struct rtentry rt;
1015 
1016 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1017 			3 * sizeof(struct sockaddr)) ||
1018 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1019 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1020 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1021 	    get_user(rt.rt_window, &ur->rt_window) ||
1022 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1023 	    get_user(rtdev, &ur->rt_dev))
1024 		return -EFAULT;
1025 
1026 	rt.rt_dev = compat_ptr(rtdev);
1027 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1028 }
1029 
1030 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1031 {
1032 	void __user *argp = compat_ptr(arg);
1033 	struct sock *sk = sock->sk;
1034 
1035 	switch (cmd) {
1036 	case SIOCADDRT:
1037 	case SIOCDELRT:
1038 		return inet_compat_routing_ioctl(sk, cmd, argp);
1039 	default:
1040 		if (!sk->sk_prot->compat_ioctl)
1041 			return -ENOIOCTLCMD;
1042 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1043 	}
1044 }
1045 #endif /* CONFIG_COMPAT */
1046 
1047 const struct proto_ops inet_stream_ops = {
1048 	.family		   = PF_INET,
1049 	.owner		   = THIS_MODULE,
1050 	.release	   = inet_release,
1051 	.bind		   = inet_bind,
1052 	.connect	   = inet_stream_connect,
1053 	.socketpair	   = sock_no_socketpair,
1054 	.accept		   = inet_accept,
1055 	.getname	   = inet_getname,
1056 	.poll		   = tcp_poll,
1057 	.ioctl		   = inet_ioctl,
1058 	.gettstamp	   = sock_gettstamp,
1059 	.listen		   = inet_listen,
1060 	.shutdown	   = inet_shutdown,
1061 	.setsockopt	   = sock_common_setsockopt,
1062 	.getsockopt	   = sock_common_getsockopt,
1063 	.sendmsg	   = inet_sendmsg,
1064 	.recvmsg	   = inet_recvmsg,
1065 #ifdef CONFIG_MMU
1066 	.mmap		   = tcp_mmap,
1067 #endif
1068 	.splice_eof	   = inet_splice_eof,
1069 	.splice_read	   = tcp_splice_read,
1070 	.read_sock	   = tcp_read_sock,
1071 	.read_skb	   = tcp_read_skb,
1072 	.sendmsg_locked    = tcp_sendmsg_locked,
1073 	.peek_len	   = tcp_peek_len,
1074 #ifdef CONFIG_COMPAT
1075 	.compat_ioctl	   = inet_compat_ioctl,
1076 #endif
1077 	.set_rcvlowat	   = tcp_set_rcvlowat,
1078 };
1079 EXPORT_SYMBOL(inet_stream_ops);
1080 
1081 const struct proto_ops inet_dgram_ops = {
1082 	.family		   = PF_INET,
1083 	.owner		   = THIS_MODULE,
1084 	.release	   = inet_release,
1085 	.bind		   = inet_bind,
1086 	.connect	   = inet_dgram_connect,
1087 	.socketpair	   = sock_no_socketpair,
1088 	.accept		   = sock_no_accept,
1089 	.getname	   = inet_getname,
1090 	.poll		   = udp_poll,
1091 	.ioctl		   = inet_ioctl,
1092 	.gettstamp	   = sock_gettstamp,
1093 	.listen		   = sock_no_listen,
1094 	.shutdown	   = inet_shutdown,
1095 	.setsockopt	   = sock_common_setsockopt,
1096 	.getsockopt	   = sock_common_getsockopt,
1097 	.sendmsg	   = inet_sendmsg,
1098 	.read_skb	   = udp_read_skb,
1099 	.recvmsg	   = inet_recvmsg,
1100 	.mmap		   = sock_no_mmap,
1101 	.splice_eof	   = inet_splice_eof,
1102 	.set_peek_off	   = sk_set_peek_off,
1103 #ifdef CONFIG_COMPAT
1104 	.compat_ioctl	   = inet_compat_ioctl,
1105 #endif
1106 };
1107 EXPORT_SYMBOL(inet_dgram_ops);
1108 
1109 /*
1110  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1111  * udp_poll
1112  */
1113 static const struct proto_ops inet_sockraw_ops = {
1114 	.family		   = PF_INET,
1115 	.owner		   = THIS_MODULE,
1116 	.release	   = inet_release,
1117 	.bind		   = inet_bind,
1118 	.connect	   = inet_dgram_connect,
1119 	.socketpair	   = sock_no_socketpair,
1120 	.accept		   = sock_no_accept,
1121 	.getname	   = inet_getname,
1122 	.poll		   = datagram_poll,
1123 	.ioctl		   = inet_ioctl,
1124 	.gettstamp	   = sock_gettstamp,
1125 	.listen		   = sock_no_listen,
1126 	.shutdown	   = inet_shutdown,
1127 	.setsockopt	   = sock_common_setsockopt,
1128 	.getsockopt	   = sock_common_getsockopt,
1129 	.sendmsg	   = inet_sendmsg,
1130 	.recvmsg	   = inet_recvmsg,
1131 	.mmap		   = sock_no_mmap,
1132 	.splice_eof	   = inet_splice_eof,
1133 #ifdef CONFIG_COMPAT
1134 	.compat_ioctl	   = inet_compat_ioctl,
1135 #endif
1136 };
1137 
1138 static const struct net_proto_family inet_family_ops = {
1139 	.family = PF_INET,
1140 	.create = inet_create,
1141 	.owner	= THIS_MODULE,
1142 };
1143 
1144 /* Upon startup we insert all the elements in inetsw_array[] into
1145  * the linked list inetsw.
1146  */
1147 static struct inet_protosw inetsw_array[] =
1148 {
1149 	{
1150 		.type =       SOCK_STREAM,
1151 		.protocol =   IPPROTO_TCP,
1152 		.prot =       &tcp_prot,
1153 		.ops =        &inet_stream_ops,
1154 		.flags =      INET_PROTOSW_PERMANENT |
1155 			      INET_PROTOSW_ICSK,
1156 	},
1157 
1158 	{
1159 		.type =       SOCK_DGRAM,
1160 		.protocol =   IPPROTO_UDP,
1161 		.prot =       &udp_prot,
1162 		.ops =        &inet_dgram_ops,
1163 		.flags =      INET_PROTOSW_PERMANENT,
1164        },
1165 
1166        {
1167 		.type =       SOCK_DGRAM,
1168 		.protocol =   IPPROTO_ICMP,
1169 		.prot =       &ping_prot,
1170 		.ops =        &inet_sockraw_ops,
1171 		.flags =      INET_PROTOSW_REUSE,
1172        },
1173 
1174        {
1175 	       .type =       SOCK_RAW,
1176 	       .protocol =   IPPROTO_IP,	/* wild card */
1177 	       .prot =       &raw_prot,
1178 	       .ops =        &inet_sockraw_ops,
1179 	       .flags =      INET_PROTOSW_REUSE,
1180        }
1181 };
1182 
1183 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1184 
1185 void inet_register_protosw(struct inet_protosw *p)
1186 {
1187 	struct list_head *lh;
1188 	struct inet_protosw *answer;
1189 	int protocol = p->protocol;
1190 	struct list_head *last_perm;
1191 
1192 	spin_lock_bh(&inetsw_lock);
1193 
1194 	if (p->type >= SOCK_MAX)
1195 		goto out_illegal;
1196 
1197 	/* If we are trying to override a permanent protocol, bail. */
1198 	last_perm = &inetsw[p->type];
1199 	list_for_each(lh, &inetsw[p->type]) {
1200 		answer = list_entry(lh, struct inet_protosw, list);
1201 		/* Check only the non-wild match. */
1202 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1203 			break;
1204 		if (protocol == answer->protocol)
1205 			goto out_permanent;
1206 		last_perm = lh;
1207 	}
1208 
1209 	/* Add the new entry after the last permanent entry if any, so that
1210 	 * the new entry does not override a permanent entry when matched with
1211 	 * a wild-card protocol. But it is allowed to override any existing
1212 	 * non-permanent entry.  This means that when we remove this entry, the
1213 	 * system automatically returns to the old behavior.
1214 	 */
1215 	list_add_rcu(&p->list, last_perm);
1216 out:
1217 	spin_unlock_bh(&inetsw_lock);
1218 
1219 	return;
1220 
1221 out_permanent:
1222 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1223 	goto out;
1224 
1225 out_illegal:
1226 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1227 	       p->type);
1228 	goto out;
1229 }
1230 EXPORT_SYMBOL(inet_register_protosw);
1231 
1232 void inet_unregister_protosw(struct inet_protosw *p)
1233 {
1234 	if (INET_PROTOSW_PERMANENT & p->flags) {
1235 		pr_err("Attempt to unregister permanent protocol %d\n",
1236 		       p->protocol);
1237 	} else {
1238 		spin_lock_bh(&inetsw_lock);
1239 		list_del_rcu(&p->list);
1240 		spin_unlock_bh(&inetsw_lock);
1241 
1242 		synchronize_net();
1243 	}
1244 }
1245 EXPORT_SYMBOL(inet_unregister_protosw);
1246 
1247 static int inet_sk_reselect_saddr(struct sock *sk)
1248 {
1249 	struct inet_sock *inet = inet_sk(sk);
1250 	__be32 old_saddr = inet->inet_saddr;
1251 	__be32 daddr = inet->inet_daddr;
1252 	struct flowi4 *fl4;
1253 	struct rtable *rt;
1254 	__be32 new_saddr;
1255 	struct ip_options_rcu *inet_opt;
1256 	int err;
1257 
1258 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1259 					     lockdep_sock_is_held(sk));
1260 	if (inet_opt && inet_opt->opt.srr)
1261 		daddr = inet_opt->opt.faddr;
1262 
1263 	/* Query new route. */
1264 	fl4 = &inet->cork.fl.u.ip4;
1265 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1266 			      sk->sk_protocol, inet->inet_sport,
1267 			      inet->inet_dport, sk);
1268 	if (IS_ERR(rt))
1269 		return PTR_ERR(rt);
1270 
1271 	new_saddr = fl4->saddr;
1272 
1273 	if (new_saddr == old_saddr) {
1274 		sk_setup_caps(sk, &rt->dst);
1275 		return 0;
1276 	}
1277 
1278 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1279 	if (err) {
1280 		ip_rt_put(rt);
1281 		return err;
1282 	}
1283 
1284 	sk_setup_caps(sk, &rt->dst);
1285 
1286 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1287 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1288 			__func__, &old_saddr, &new_saddr);
1289 	}
1290 
1291 	/*
1292 	 * XXX The only one ugly spot where we need to
1293 	 * XXX really change the sockets identity after
1294 	 * XXX it has entered the hashes. -DaveM
1295 	 *
1296 	 * Besides that, it does not check for connection
1297 	 * uniqueness. Wait for troubles.
1298 	 */
1299 	return __sk_prot_rehash(sk);
1300 }
1301 
1302 int inet_sk_rebuild_header(struct sock *sk)
1303 {
1304 	struct inet_sock *inet = inet_sk(sk);
1305 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1306 	__be32 daddr;
1307 	struct ip_options_rcu *inet_opt;
1308 	struct flowi4 *fl4;
1309 	int err;
1310 
1311 	/* Route is OK, nothing to do. */
1312 	if (rt)
1313 		return 0;
1314 
1315 	/* Reroute. */
1316 	rcu_read_lock();
1317 	inet_opt = rcu_dereference(inet->inet_opt);
1318 	daddr = inet->inet_daddr;
1319 	if (inet_opt && inet_opt->opt.srr)
1320 		daddr = inet_opt->opt.faddr;
1321 	rcu_read_unlock();
1322 	fl4 = &inet->cork.fl.u.ip4;
1323 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1324 				   inet->inet_dport, inet->inet_sport,
1325 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1326 				   sk->sk_bound_dev_if);
1327 	if (!IS_ERR(rt)) {
1328 		err = 0;
1329 		sk_setup_caps(sk, &rt->dst);
1330 	} else {
1331 		err = PTR_ERR(rt);
1332 
1333 		/* Routing failed... */
1334 		sk->sk_route_caps = 0;
1335 		/*
1336 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1337 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1338 		 */
1339 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1340 		    sk->sk_state != TCP_SYN_SENT ||
1341 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1342 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1343 			WRITE_ONCE(sk->sk_err_soft, -err);
1344 	}
1345 
1346 	return err;
1347 }
1348 EXPORT_SYMBOL(inet_sk_rebuild_header);
1349 
1350 void inet_sk_set_state(struct sock *sk, int state)
1351 {
1352 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1353 	sk->sk_state = state;
1354 }
1355 EXPORT_SYMBOL(inet_sk_set_state);
1356 
1357 void inet_sk_state_store(struct sock *sk, int newstate)
1358 {
1359 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1360 	smp_store_release(&sk->sk_state, newstate);
1361 }
1362 
1363 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1364 				 netdev_features_t features)
1365 {
1366 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1367 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1368 	const struct net_offload *ops;
1369 	unsigned int offset = 0;
1370 	struct iphdr *iph;
1371 	int proto, tot_len;
1372 	int nhoff;
1373 	int ihl;
1374 	int id;
1375 
1376 	skb_reset_network_header(skb);
1377 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1378 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1379 		goto out;
1380 
1381 	iph = ip_hdr(skb);
1382 	ihl = iph->ihl * 4;
1383 	if (ihl < sizeof(*iph))
1384 		goto out;
1385 
1386 	id = ntohs(iph->id);
1387 	proto = iph->protocol;
1388 
1389 	/* Warning: after this point, iph might be no longer valid */
1390 	if (unlikely(!pskb_may_pull(skb, ihl)))
1391 		goto out;
1392 	__skb_pull(skb, ihl);
1393 
1394 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1395 	if (encap)
1396 		features &= skb->dev->hw_enc_features;
1397 	SKB_GSO_CB(skb)->encap_level += ihl;
1398 
1399 	skb_reset_transport_header(skb);
1400 
1401 	segs = ERR_PTR(-EPROTONOSUPPORT);
1402 
1403 	if (!skb->encapsulation || encap) {
1404 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1405 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1406 
1407 		/* fixed ID is invalid if DF bit is not set */
1408 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1409 			goto out;
1410 	}
1411 
1412 	ops = rcu_dereference(inet_offloads[proto]);
1413 	if (likely(ops && ops->callbacks.gso_segment)) {
1414 		segs = ops->callbacks.gso_segment(skb, features);
1415 		if (!segs)
1416 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1417 	}
1418 
1419 	if (IS_ERR_OR_NULL(segs))
1420 		goto out;
1421 
1422 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1423 
1424 	skb = segs;
1425 	do {
1426 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1427 		if (udpfrag) {
1428 			iph->frag_off = htons(offset >> 3);
1429 			if (skb->next)
1430 				iph->frag_off |= htons(IP_MF);
1431 			offset += skb->len - nhoff - ihl;
1432 			tot_len = skb->len - nhoff;
1433 		} else if (skb_is_gso(skb)) {
1434 			if (!fixedid) {
1435 				iph->id = htons(id);
1436 				id += skb_shinfo(skb)->gso_segs;
1437 			}
1438 
1439 			if (gso_partial)
1440 				tot_len = skb_shinfo(skb)->gso_size +
1441 					  SKB_GSO_CB(skb)->data_offset +
1442 					  skb->head - (unsigned char *)iph;
1443 			else
1444 				tot_len = skb->len - nhoff;
1445 		} else {
1446 			if (!fixedid)
1447 				iph->id = htons(id++);
1448 			tot_len = skb->len - nhoff;
1449 		}
1450 		iph->tot_len = htons(tot_len);
1451 		ip_send_check(iph);
1452 		if (encap)
1453 			skb_reset_inner_headers(skb);
1454 		skb->network_header = (u8 *)iph - skb->head;
1455 		skb_reset_mac_len(skb);
1456 	} while ((skb = skb->next));
1457 
1458 out:
1459 	return segs;
1460 }
1461 
1462 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1463 					netdev_features_t features)
1464 {
1465 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1466 		return ERR_PTR(-EINVAL);
1467 
1468 	return inet_gso_segment(skb, features);
1469 }
1470 
1471 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1472 {
1473 	const struct net_offload *ops;
1474 	struct sk_buff *pp = NULL;
1475 	const struct iphdr *iph;
1476 	struct sk_buff *p;
1477 	unsigned int hlen;
1478 	unsigned int off;
1479 	unsigned int id;
1480 	int flush = 1;
1481 	int proto;
1482 
1483 	off = skb_gro_offset(skb);
1484 	hlen = off + sizeof(*iph);
1485 	iph = skb_gro_header(skb, hlen, off);
1486 	if (unlikely(!iph))
1487 		goto out;
1488 
1489 	proto = iph->protocol;
1490 
1491 	ops = rcu_dereference(inet_offloads[proto]);
1492 	if (!ops || !ops->callbacks.gro_receive)
1493 		goto out;
1494 
1495 	if (*(u8 *)iph != 0x45)
1496 		goto out;
1497 
1498 	if (ip_is_fragment(iph))
1499 		goto out;
1500 
1501 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1502 		goto out;
1503 
1504 	NAPI_GRO_CB(skb)->proto = proto;
1505 	id = ntohl(*(__be32 *)&iph->id);
1506 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1507 	id >>= 16;
1508 
1509 	list_for_each_entry(p, head, list) {
1510 		struct iphdr *iph2;
1511 		u16 flush_id;
1512 
1513 		if (!NAPI_GRO_CB(p)->same_flow)
1514 			continue;
1515 
1516 		iph2 = (struct iphdr *)(p->data + off);
1517 		/* The above works because, with the exception of the top
1518 		 * (inner most) layer, we only aggregate pkts with the same
1519 		 * hdr length so all the hdrs we'll need to verify will start
1520 		 * at the same offset.
1521 		 */
1522 		if ((iph->protocol ^ iph2->protocol) |
1523 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1524 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1525 			NAPI_GRO_CB(p)->same_flow = 0;
1526 			continue;
1527 		}
1528 
1529 		/* All fields must match except length and checksum. */
1530 		NAPI_GRO_CB(p)->flush |=
1531 			(iph->ttl ^ iph2->ttl) |
1532 			(iph->tos ^ iph2->tos) |
1533 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1534 
1535 		NAPI_GRO_CB(p)->flush |= flush;
1536 
1537 		/* We need to store of the IP ID check to be included later
1538 		 * when we can verify that this packet does in fact belong
1539 		 * to a given flow.
1540 		 */
1541 		flush_id = (u16)(id - ntohs(iph2->id));
1542 
1543 		/* This bit of code makes it much easier for us to identify
1544 		 * the cases where we are doing atomic vs non-atomic IP ID
1545 		 * checks.  Specifically an atomic check can return IP ID
1546 		 * values 0 - 0xFFFF, while a non-atomic check can only
1547 		 * return 0 or 0xFFFF.
1548 		 */
1549 		if (!NAPI_GRO_CB(p)->is_atomic ||
1550 		    !(iph->frag_off & htons(IP_DF))) {
1551 			flush_id ^= NAPI_GRO_CB(p)->count;
1552 			flush_id = flush_id ? 0xFFFF : 0;
1553 		}
1554 
1555 		/* If the previous IP ID value was based on an atomic
1556 		 * datagram we can overwrite the value and ignore it.
1557 		 */
1558 		if (NAPI_GRO_CB(skb)->is_atomic)
1559 			NAPI_GRO_CB(p)->flush_id = flush_id;
1560 		else
1561 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1562 	}
1563 
1564 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1565 	NAPI_GRO_CB(skb)->flush |= flush;
1566 	skb_set_network_header(skb, off);
1567 	/* The above will be needed by the transport layer if there is one
1568 	 * immediately following this IP hdr.
1569 	 */
1570 
1571 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1572 	 * as we already checked checksum over ipv4 header was 0
1573 	 */
1574 	skb_gro_pull(skb, sizeof(*iph));
1575 	skb_set_transport_header(skb, skb_gro_offset(skb));
1576 
1577 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1578 				       ops->callbacks.gro_receive, head, skb);
1579 
1580 out:
1581 	skb_gro_flush_final(skb, pp, flush);
1582 
1583 	return pp;
1584 }
1585 
1586 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1587 					struct sk_buff *skb)
1588 {
1589 	if (NAPI_GRO_CB(skb)->encap_mark) {
1590 		NAPI_GRO_CB(skb)->flush = 1;
1591 		return NULL;
1592 	}
1593 
1594 	NAPI_GRO_CB(skb)->encap_mark = 1;
1595 
1596 	return inet_gro_receive(head, skb);
1597 }
1598 
1599 #define SECONDS_PER_DAY	86400
1600 
1601 /* inet_current_timestamp - Return IP network timestamp
1602  *
1603  * Return milliseconds since midnight in network byte order.
1604  */
1605 __be32 inet_current_timestamp(void)
1606 {
1607 	u32 secs;
1608 	u32 msecs;
1609 	struct timespec64 ts;
1610 
1611 	ktime_get_real_ts64(&ts);
1612 
1613 	/* Get secs since midnight. */
1614 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1615 	/* Convert to msecs. */
1616 	msecs = secs * MSEC_PER_SEC;
1617 	/* Convert nsec to msec. */
1618 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1619 
1620 	/* Convert to network byte order. */
1621 	return htonl(msecs);
1622 }
1623 EXPORT_SYMBOL(inet_current_timestamp);
1624 
1625 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1626 {
1627 	if (sk->sk_family == AF_INET)
1628 		return ip_recv_error(sk, msg, len, addr_len);
1629 #if IS_ENABLED(CONFIG_IPV6)
1630 	if (sk->sk_family == AF_INET6)
1631 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1632 #endif
1633 	return -EINVAL;
1634 }
1635 
1636 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1637 {
1638 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1639 	const struct net_offload *ops;
1640 	__be16 totlen = iph->tot_len;
1641 	int proto = iph->protocol;
1642 	int err = -ENOSYS;
1643 
1644 	if (skb->encapsulation) {
1645 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1646 		skb_set_inner_network_header(skb, nhoff);
1647 	}
1648 
1649 	iph_set_totlen(iph, skb->len - nhoff);
1650 	csum_replace2(&iph->check, totlen, iph->tot_len);
1651 
1652 	ops = rcu_dereference(inet_offloads[proto]);
1653 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1654 		goto out;
1655 
1656 	/* Only need to add sizeof(*iph) to get to the next hdr below
1657 	 * because any hdr with option will have been flushed in
1658 	 * inet_gro_receive().
1659 	 */
1660 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1661 			      tcp4_gro_complete, udp4_gro_complete,
1662 			      skb, nhoff + sizeof(*iph));
1663 
1664 out:
1665 	return err;
1666 }
1667 
1668 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1669 {
1670 	skb->encapsulation = 1;
1671 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1672 	return inet_gro_complete(skb, nhoff);
1673 }
1674 
1675 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1676 			 unsigned short type, unsigned char protocol,
1677 			 struct net *net)
1678 {
1679 	struct socket *sock;
1680 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1681 
1682 	if (rc == 0) {
1683 		*sk = sock->sk;
1684 		(*sk)->sk_allocation = GFP_ATOMIC;
1685 		(*sk)->sk_use_task_frag = false;
1686 		/*
1687 		 * Unhash it so that IP input processing does not even see it,
1688 		 * we do not wish this socket to see incoming packets.
1689 		 */
1690 		(*sk)->sk_prot->unhash(*sk);
1691 	}
1692 	return rc;
1693 }
1694 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1695 
1696 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1697 {
1698 	unsigned long res = 0;
1699 	int i;
1700 
1701 	for_each_possible_cpu(i)
1702 		res += snmp_get_cpu_field(mib, i, offt);
1703 	return res;
1704 }
1705 EXPORT_SYMBOL_GPL(snmp_fold_field);
1706 
1707 #if BITS_PER_LONG==32
1708 
1709 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1710 			 size_t syncp_offset)
1711 {
1712 	void *bhptr;
1713 	struct u64_stats_sync *syncp;
1714 	u64 v;
1715 	unsigned int start;
1716 
1717 	bhptr = per_cpu_ptr(mib, cpu);
1718 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1719 	do {
1720 		start = u64_stats_fetch_begin(syncp);
1721 		v = *(((u64 *)bhptr) + offt);
1722 	} while (u64_stats_fetch_retry(syncp, start));
1723 
1724 	return v;
1725 }
1726 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1727 
1728 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1729 {
1730 	u64 res = 0;
1731 	int cpu;
1732 
1733 	for_each_possible_cpu(cpu) {
1734 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1735 	}
1736 	return res;
1737 }
1738 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1739 #endif
1740 
1741 #ifdef CONFIG_IP_MULTICAST
1742 static const struct net_protocol igmp_protocol = {
1743 	.handler =	igmp_rcv,
1744 };
1745 #endif
1746 
1747 static const struct net_protocol tcp_protocol = {
1748 	.handler	=	tcp_v4_rcv,
1749 	.err_handler	=	tcp_v4_err,
1750 	.no_policy	=	1,
1751 	.icmp_strict_tag_validation = 1,
1752 };
1753 
1754 static const struct net_protocol udp_protocol = {
1755 	.handler =	udp_rcv,
1756 	.err_handler =	udp_err,
1757 	.no_policy =	1,
1758 };
1759 
1760 static const struct net_protocol icmp_protocol = {
1761 	.handler =	icmp_rcv,
1762 	.err_handler =	icmp_err,
1763 	.no_policy =	1,
1764 };
1765 
1766 static __net_init int ipv4_mib_init_net(struct net *net)
1767 {
1768 	int i;
1769 
1770 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1771 	if (!net->mib.tcp_statistics)
1772 		goto err_tcp_mib;
1773 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1774 	if (!net->mib.ip_statistics)
1775 		goto err_ip_mib;
1776 
1777 	for_each_possible_cpu(i) {
1778 		struct ipstats_mib *af_inet_stats;
1779 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1780 		u64_stats_init(&af_inet_stats->syncp);
1781 	}
1782 
1783 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1784 	if (!net->mib.net_statistics)
1785 		goto err_net_mib;
1786 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1787 	if (!net->mib.udp_statistics)
1788 		goto err_udp_mib;
1789 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1790 	if (!net->mib.udplite_statistics)
1791 		goto err_udplite_mib;
1792 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1793 	if (!net->mib.icmp_statistics)
1794 		goto err_icmp_mib;
1795 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1796 					      GFP_KERNEL);
1797 	if (!net->mib.icmpmsg_statistics)
1798 		goto err_icmpmsg_mib;
1799 
1800 	tcp_mib_init(net);
1801 	return 0;
1802 
1803 err_icmpmsg_mib:
1804 	free_percpu(net->mib.icmp_statistics);
1805 err_icmp_mib:
1806 	free_percpu(net->mib.udplite_statistics);
1807 err_udplite_mib:
1808 	free_percpu(net->mib.udp_statistics);
1809 err_udp_mib:
1810 	free_percpu(net->mib.net_statistics);
1811 err_net_mib:
1812 	free_percpu(net->mib.ip_statistics);
1813 err_ip_mib:
1814 	free_percpu(net->mib.tcp_statistics);
1815 err_tcp_mib:
1816 	return -ENOMEM;
1817 }
1818 
1819 static __net_exit void ipv4_mib_exit_net(struct net *net)
1820 {
1821 	kfree(net->mib.icmpmsg_statistics);
1822 	free_percpu(net->mib.icmp_statistics);
1823 	free_percpu(net->mib.udplite_statistics);
1824 	free_percpu(net->mib.udp_statistics);
1825 	free_percpu(net->mib.net_statistics);
1826 	free_percpu(net->mib.ip_statistics);
1827 	free_percpu(net->mib.tcp_statistics);
1828 #ifdef CONFIG_MPTCP
1829 	/* allocated on demand, see mptcp_init_sock() */
1830 	free_percpu(net->mib.mptcp_statistics);
1831 #endif
1832 }
1833 
1834 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1835 	.init = ipv4_mib_init_net,
1836 	.exit = ipv4_mib_exit_net,
1837 };
1838 
1839 static int __init init_ipv4_mibs(void)
1840 {
1841 	return register_pernet_subsys(&ipv4_mib_ops);
1842 }
1843 
1844 static __net_init int inet_init_net(struct net *net)
1845 {
1846 	/*
1847 	 * Set defaults for local port range
1848 	 */
1849 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1850 	net->ipv4.ip_local_ports.range[0] =  32768;
1851 	net->ipv4.ip_local_ports.range[1] =  60999;
1852 
1853 	seqlock_init(&net->ipv4.ping_group_range.lock);
1854 	/*
1855 	 * Sane defaults - nobody may create ping sockets.
1856 	 * Boot scripts should set this to distro-specific group.
1857 	 */
1858 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1859 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1860 
1861 	/* Default values for sysctl-controlled parameters.
1862 	 * We set them here, in case sysctl is not compiled.
1863 	 */
1864 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1865 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1866 	net->ipv4.sysctl_ip_dynaddr = 0;
1867 	net->ipv4.sysctl_ip_early_demux = 1;
1868 	net->ipv4.sysctl_udp_early_demux = 1;
1869 	net->ipv4.sysctl_tcp_early_demux = 1;
1870 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1871 #ifdef CONFIG_SYSCTL
1872 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1873 #endif
1874 
1875 	/* Some igmp sysctl, whose values are always used */
1876 	net->ipv4.sysctl_igmp_max_memberships = 20;
1877 	net->ipv4.sysctl_igmp_max_msf = 10;
1878 	/* IGMP reports for link-local multicast groups are enabled by default */
1879 	net->ipv4.sysctl_igmp_llm_reports = 1;
1880 	net->ipv4.sysctl_igmp_qrv = 2;
1881 
1882 	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1883 
1884 	return 0;
1885 }
1886 
1887 static __net_initdata struct pernet_operations af_inet_ops = {
1888 	.init = inet_init_net,
1889 };
1890 
1891 static int __init init_inet_pernet_ops(void)
1892 {
1893 	return register_pernet_subsys(&af_inet_ops);
1894 }
1895 
1896 static int ipv4_proc_init(void);
1897 
1898 /*
1899  *	IP protocol layer initialiser
1900  */
1901 
1902 static struct packet_offload ip_packet_offload __read_mostly = {
1903 	.type = cpu_to_be16(ETH_P_IP),
1904 	.callbacks = {
1905 		.gso_segment = inet_gso_segment,
1906 		.gro_receive = inet_gro_receive,
1907 		.gro_complete = inet_gro_complete,
1908 	},
1909 };
1910 
1911 static const struct net_offload ipip_offload = {
1912 	.callbacks = {
1913 		.gso_segment	= ipip_gso_segment,
1914 		.gro_receive	= ipip_gro_receive,
1915 		.gro_complete	= ipip_gro_complete,
1916 	},
1917 };
1918 
1919 static int __init ipip_offload_init(void)
1920 {
1921 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1922 }
1923 
1924 static int __init ipv4_offload_init(void)
1925 {
1926 	/*
1927 	 * Add offloads
1928 	 */
1929 	if (udpv4_offload_init() < 0)
1930 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1931 	if (tcpv4_offload_init() < 0)
1932 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1933 	if (ipip_offload_init() < 0)
1934 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1935 
1936 	dev_add_offload(&ip_packet_offload);
1937 	return 0;
1938 }
1939 
1940 fs_initcall(ipv4_offload_init);
1941 
1942 static struct packet_type ip_packet_type __read_mostly = {
1943 	.type = cpu_to_be16(ETH_P_IP),
1944 	.func = ip_rcv,
1945 	.list_func = ip_list_rcv,
1946 };
1947 
1948 static int __init inet_init(void)
1949 {
1950 	struct inet_protosw *q;
1951 	struct list_head *r;
1952 	int rc;
1953 
1954 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1955 
1956 	raw_hashinfo_init(&raw_v4_hashinfo);
1957 
1958 	rc = proto_register(&tcp_prot, 1);
1959 	if (rc)
1960 		goto out;
1961 
1962 	rc = proto_register(&udp_prot, 1);
1963 	if (rc)
1964 		goto out_unregister_tcp_proto;
1965 
1966 	rc = proto_register(&raw_prot, 1);
1967 	if (rc)
1968 		goto out_unregister_udp_proto;
1969 
1970 	rc = proto_register(&ping_prot, 1);
1971 	if (rc)
1972 		goto out_unregister_raw_proto;
1973 
1974 	/*
1975 	 *	Tell SOCKET that we are alive...
1976 	 */
1977 
1978 	(void)sock_register(&inet_family_ops);
1979 
1980 #ifdef CONFIG_SYSCTL
1981 	ip_static_sysctl_init();
1982 #endif
1983 
1984 	/*
1985 	 *	Add all the base protocols.
1986 	 */
1987 
1988 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1989 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1990 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1991 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1992 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1993 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1994 #ifdef CONFIG_IP_MULTICAST
1995 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1996 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1997 #endif
1998 
1999 	/* Register the socket-side information for inet_create. */
2000 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2001 		INIT_LIST_HEAD(r);
2002 
2003 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2004 		inet_register_protosw(q);
2005 
2006 	/*
2007 	 *	Set the ARP module up
2008 	 */
2009 
2010 	arp_init();
2011 
2012 	/*
2013 	 *	Set the IP module up
2014 	 */
2015 
2016 	ip_init();
2017 
2018 	/* Initialise per-cpu ipv4 mibs */
2019 	if (init_ipv4_mibs())
2020 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2021 
2022 	/* Setup TCP slab cache for open requests. */
2023 	tcp_init();
2024 
2025 	/* Setup UDP memory threshold */
2026 	udp_init();
2027 
2028 	/* Add UDP-Lite (RFC 3828) */
2029 	udplite4_register();
2030 
2031 	raw_init();
2032 
2033 	ping_init();
2034 
2035 	/*
2036 	 *	Set the ICMP layer up
2037 	 */
2038 
2039 	if (icmp_init() < 0)
2040 		panic("Failed to create the ICMP control socket.\n");
2041 
2042 	/*
2043 	 *	Initialise the multicast router
2044 	 */
2045 #if defined(CONFIG_IP_MROUTE)
2046 	if (ip_mr_init())
2047 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2048 #endif
2049 
2050 	if (init_inet_pernet_ops())
2051 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2052 
2053 	ipv4_proc_init();
2054 
2055 	ipfrag_init();
2056 
2057 	dev_add_pack(&ip_packet_type);
2058 
2059 	ip_tunnel_core_init();
2060 
2061 	rc = 0;
2062 out:
2063 	return rc;
2064 out_unregister_raw_proto:
2065 	proto_unregister(&raw_prot);
2066 out_unregister_udp_proto:
2067 	proto_unregister(&udp_prot);
2068 out_unregister_tcp_proto:
2069 	proto_unregister(&tcp_prot);
2070 	goto out;
2071 }
2072 
2073 fs_initcall(inet_init);
2074 
2075 /* ------------------------------------------------------------------------ */
2076 
2077 #ifdef CONFIG_PROC_FS
2078 static int __init ipv4_proc_init(void)
2079 {
2080 	int rc = 0;
2081 
2082 	if (raw_proc_init())
2083 		goto out_raw;
2084 	if (tcp4_proc_init())
2085 		goto out_tcp;
2086 	if (udp4_proc_init())
2087 		goto out_udp;
2088 	if (ping_proc_init())
2089 		goto out_ping;
2090 	if (ip_misc_proc_init())
2091 		goto out_misc;
2092 out:
2093 	return rc;
2094 out_misc:
2095 	ping_proc_exit();
2096 out_ping:
2097 	udp4_proc_exit();
2098 out_udp:
2099 	tcp4_proc_exit();
2100 out_tcp:
2101 	raw_proc_exit();
2102 out_raw:
2103 	rc = -ENOMEM;
2104 	goto out;
2105 }
2106 
2107 #else /* CONFIG_PROC_FS */
2108 static int __init ipv4_proc_init(void)
2109 {
2110 	return 0;
2111 }
2112 #endif /* CONFIG_PROC_FS */
2113