xref: /openbmc/linux/net/ipv4/af_inet.c (revision abb84c46)
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 	if (INET_PROTOSW_ICSK & answer_flags)
334 		inet_init_csk_locks(sk);
335 
336 	inet = inet_sk(sk);
337 	inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
338 
339 	inet_clear_bit(NODEFRAG, sk);
340 
341 	if (SOCK_RAW == sock->type) {
342 		inet->inet_num = protocol;
343 		if (IPPROTO_RAW == protocol)
344 			inet_set_bit(HDRINCL, sk);
345 	}
346 
347 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
348 		inet->pmtudisc = IP_PMTUDISC_DONT;
349 	else
350 		inet->pmtudisc = IP_PMTUDISC_WANT;
351 
352 	atomic_set(&inet->inet_id, 0);
353 
354 	sock_init_data(sock, sk);
355 
356 	sk->sk_destruct	   = inet_sock_destruct;
357 	sk->sk_protocol	   = protocol;
358 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
359 	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
360 
361 	inet->uc_ttl	= -1;
362 	inet_set_bit(MC_LOOP, sk);
363 	inet->mc_ttl	= 1;
364 	inet_set_bit(MC_ALL, sk);
365 	inet->mc_index	= 0;
366 	inet->mc_list	= NULL;
367 	inet->rcv_tos	= 0;
368 
369 	if (inet->inet_num) {
370 		/* It assumes that any protocol which allows
371 		 * the user to assign a number at socket
372 		 * creation time automatically
373 		 * shares.
374 		 */
375 		inet->inet_sport = htons(inet->inet_num);
376 		/* Add to protocol hash chains. */
377 		err = sk->sk_prot->hash(sk);
378 		if (err) {
379 			sk_common_release(sk);
380 			goto out;
381 		}
382 	}
383 
384 	if (sk->sk_prot->init) {
385 		err = sk->sk_prot->init(sk);
386 		if (err) {
387 			sk_common_release(sk);
388 			goto out;
389 		}
390 	}
391 
392 	if (!kern) {
393 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
394 		if (err) {
395 			sk_common_release(sk);
396 			goto out;
397 		}
398 	}
399 out:
400 	return err;
401 out_rcu_unlock:
402 	rcu_read_unlock();
403 	goto out;
404 }
405 
406 
407 /*
408  *	The peer socket should always be NULL (or else). When we call this
409  *	function we are destroying the object and from then on nobody
410  *	should refer to it.
411  */
412 int inet_release(struct socket *sock)
413 {
414 	struct sock *sk = sock->sk;
415 
416 	if (sk) {
417 		long timeout;
418 
419 		if (!sk->sk_kern_sock)
420 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
421 
422 		/* Applications forget to leave groups before exiting */
423 		ip_mc_drop_socket(sk);
424 
425 		/* If linger is set, we don't return until the close
426 		 * is complete.  Otherwise we return immediately. The
427 		 * actually closing is done the same either way.
428 		 *
429 		 * If the close is due to the process exiting, we never
430 		 * linger..
431 		 */
432 		timeout = 0;
433 		if (sock_flag(sk, SOCK_LINGER) &&
434 		    !(current->flags & PF_EXITING))
435 			timeout = sk->sk_lingertime;
436 		sk->sk_prot->close(sk, timeout);
437 		sock->sk = NULL;
438 	}
439 	return 0;
440 }
441 EXPORT_SYMBOL(inet_release);
442 
443 int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
444 {
445 	u32 flags = BIND_WITH_LOCK;
446 	int err;
447 
448 	/* If the socket has its own bind function then use it. (RAW) */
449 	if (sk->sk_prot->bind) {
450 		return sk->sk_prot->bind(sk, uaddr, addr_len);
451 	}
452 	if (addr_len < sizeof(struct sockaddr_in))
453 		return -EINVAL;
454 
455 	/* BPF prog is run before any checks are done so that if the prog
456 	 * changes context in a wrong way it will be caught.
457 	 */
458 	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len,
459 						 CGROUP_INET4_BIND, &flags);
460 	if (err)
461 		return err;
462 
463 	return __inet_bind(sk, uaddr, addr_len, flags);
464 }
465 
466 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
467 {
468 	return inet_bind_sk(sock->sk, uaddr, addr_len);
469 }
470 EXPORT_SYMBOL(inet_bind);
471 
472 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
473 		u32 flags)
474 {
475 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
476 	struct inet_sock *inet = inet_sk(sk);
477 	struct net *net = sock_net(sk);
478 	unsigned short snum;
479 	int chk_addr_ret;
480 	u32 tb_id = RT_TABLE_LOCAL;
481 	int err;
482 
483 	if (addr->sin_family != AF_INET) {
484 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
485 		 * only if s_addr is INADDR_ANY.
486 		 */
487 		err = -EAFNOSUPPORT;
488 		if (addr->sin_family != AF_UNSPEC ||
489 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
490 			goto out;
491 	}
492 
493 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
494 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
495 
496 	/* Not specified by any standard per-se, however it breaks too
497 	 * many applications when removed.  It is unfortunate since
498 	 * allowing applications to make a non-local bind solves
499 	 * several problems with systems using dynamic addressing.
500 	 * (ie. your servers still start up even if your ISDN link
501 	 *  is temporarily down)
502 	 */
503 	err = -EADDRNOTAVAIL;
504 	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
505 	                                 chk_addr_ret))
506 		goto out;
507 
508 	snum = ntohs(addr->sin_port);
509 	err = -EACCES;
510 	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
511 	    snum && inet_port_requires_bind_service(net, snum) &&
512 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
513 		goto out;
514 
515 	/*      We keep a pair of addresses. rcv_saddr is the one
516 	 *      used by hash lookups, and saddr is used for transmit.
517 	 *
518 	 *      In the BSD API these are the same except where it
519 	 *      would be illegal to use them (multicast/broadcast) in
520 	 *      which case the sending device address is used.
521 	 */
522 	if (flags & BIND_WITH_LOCK)
523 		lock_sock(sk);
524 
525 	/* Check these errors (active socket, double bind). */
526 	err = -EINVAL;
527 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
528 		goto out_release_sock;
529 
530 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
531 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
532 		inet->inet_saddr = 0;  /* Use device */
533 
534 	/* Make sure we are allowed to bind here. */
535 	if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
536 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
537 		err = sk->sk_prot->get_port(sk, snum);
538 		if (err) {
539 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
540 			goto out_release_sock;
541 		}
542 		if (!(flags & BIND_FROM_BPF)) {
543 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
544 			if (err) {
545 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
546 				if (sk->sk_prot->put_port)
547 					sk->sk_prot->put_port(sk);
548 				goto out_release_sock;
549 			}
550 		}
551 	}
552 
553 	if (inet->inet_rcv_saddr)
554 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
555 	if (snum)
556 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
557 	inet->inet_sport = htons(inet->inet_num);
558 	inet->inet_daddr = 0;
559 	inet->inet_dport = 0;
560 	sk_dst_reset(sk);
561 	err = 0;
562 out_release_sock:
563 	if (flags & BIND_WITH_LOCK)
564 		release_sock(sk);
565 out:
566 	return err;
567 }
568 
569 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
570 		       int addr_len, int flags)
571 {
572 	struct sock *sk = sock->sk;
573 	const struct proto *prot;
574 	int err;
575 
576 	if (addr_len < sizeof(uaddr->sa_family))
577 		return -EINVAL;
578 
579 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
580 	prot = READ_ONCE(sk->sk_prot);
581 
582 	if (uaddr->sa_family == AF_UNSPEC)
583 		return prot->disconnect(sk, flags);
584 
585 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
586 		err = prot->pre_connect(sk, uaddr, addr_len);
587 		if (err)
588 			return err;
589 	}
590 
591 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
592 		return -EAGAIN;
593 	return prot->connect(sk, uaddr, addr_len);
594 }
595 EXPORT_SYMBOL(inet_dgram_connect);
596 
597 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
598 {
599 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
600 
601 	add_wait_queue(sk_sleep(sk), &wait);
602 	sk->sk_write_pending += writebias;
603 
604 	/* Basic assumption: if someone sets sk->sk_err, he _must_
605 	 * change state of the socket from TCP_SYN_*.
606 	 * Connect() does not allow to get error notifications
607 	 * without closing the socket.
608 	 */
609 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
610 		release_sock(sk);
611 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
612 		lock_sock(sk);
613 		if (signal_pending(current) || !timeo)
614 			break;
615 	}
616 	remove_wait_queue(sk_sleep(sk), &wait);
617 	sk->sk_write_pending -= writebias;
618 	return timeo;
619 }
620 
621 /*
622  *	Connect to a remote host. There is regrettably still a little
623  *	TCP 'magic' in here.
624  */
625 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
626 			  int addr_len, int flags, int is_sendmsg)
627 {
628 	struct sock *sk = sock->sk;
629 	int err;
630 	long timeo;
631 
632 	/*
633 	 * uaddr can be NULL and addr_len can be 0 if:
634 	 * sk is a TCP fastopen active socket and
635 	 * TCP_FASTOPEN_CONNECT sockopt is set and
636 	 * we already have a valid cookie for this socket.
637 	 * In this case, user can call write() after connect().
638 	 * write() will invoke tcp_sendmsg_fastopen() which calls
639 	 * __inet_stream_connect().
640 	 */
641 	if (uaddr) {
642 		if (addr_len < sizeof(uaddr->sa_family))
643 			return -EINVAL;
644 
645 		if (uaddr->sa_family == AF_UNSPEC) {
646 			sk->sk_disconnects++;
647 			err = sk->sk_prot->disconnect(sk, flags);
648 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
649 			goto out;
650 		}
651 	}
652 
653 	switch (sock->state) {
654 	default:
655 		err = -EINVAL;
656 		goto out;
657 	case SS_CONNECTED:
658 		err = -EISCONN;
659 		goto out;
660 	case SS_CONNECTING:
661 		if (inet_test_bit(DEFER_CONNECT, sk))
662 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
663 		else
664 			err = -EALREADY;
665 		/* Fall out of switch with err, set for this state */
666 		break;
667 	case SS_UNCONNECTED:
668 		err = -EISCONN;
669 		if (sk->sk_state != TCP_CLOSE)
670 			goto out;
671 
672 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
673 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
674 			if (err)
675 				goto out;
676 		}
677 
678 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
679 		if (err < 0)
680 			goto out;
681 
682 		sock->state = SS_CONNECTING;
683 
684 		if (!err && inet_test_bit(DEFER_CONNECT, sk))
685 			goto out;
686 
687 		/* Just entered SS_CONNECTING state; the only
688 		 * difference is that return value in non-blocking
689 		 * case is EINPROGRESS, rather than EALREADY.
690 		 */
691 		err = -EINPROGRESS;
692 		break;
693 	}
694 
695 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
696 
697 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
698 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
699 				tcp_sk(sk)->fastopen_req &&
700 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
701 		int dis = sk->sk_disconnects;
702 
703 		/* Error code is set above */
704 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
705 			goto out;
706 
707 		err = sock_intr_errno(timeo);
708 		if (signal_pending(current))
709 			goto out;
710 
711 		if (dis != sk->sk_disconnects) {
712 			err = -EPIPE;
713 			goto out;
714 		}
715 	}
716 
717 	/* Connection was closed by RST, timeout, ICMP error
718 	 * or another process disconnected us.
719 	 */
720 	if (sk->sk_state == TCP_CLOSE)
721 		goto sock_error;
722 
723 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
724 	 * and error was received after socket entered established state.
725 	 * Hence, it is handled normally after connect() return successfully.
726 	 */
727 
728 	sock->state = SS_CONNECTED;
729 	err = 0;
730 out:
731 	return err;
732 
733 sock_error:
734 	err = sock_error(sk) ? : -ECONNABORTED;
735 	sock->state = SS_UNCONNECTED;
736 	sk->sk_disconnects++;
737 	if (sk->sk_prot->disconnect(sk, flags))
738 		sock->state = SS_DISCONNECTING;
739 	goto out;
740 }
741 EXPORT_SYMBOL(__inet_stream_connect);
742 
743 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
744 			int addr_len, int flags)
745 {
746 	int err;
747 
748 	lock_sock(sock->sk);
749 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
750 	release_sock(sock->sk);
751 	return err;
752 }
753 EXPORT_SYMBOL(inet_stream_connect);
754 
755 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
756 {
757 	sock_rps_record_flow(newsk);
758 	WARN_ON(!((1 << newsk->sk_state) &
759 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
760 		   TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 |
761 		   TCPF_CLOSING | TCPF_CLOSE_WAIT |
762 		   TCPF_CLOSE)));
763 
764 	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
765 		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
766 	sock_graft(newsk, newsock);
767 
768 	newsock->state = SS_CONNECTED;
769 }
770 
771 /*
772  *	Accept a pending connection. The TCP layer now gives BSD semantics.
773  */
774 
775 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
776 		bool kern)
777 {
778 	struct sock *sk1 = sock->sk, *sk2;
779 	int err = -EINVAL;
780 
781 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
782 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
783 	if (!sk2)
784 		return err;
785 
786 	lock_sock(sk2);
787 	__inet_accept(sock, newsock, sk2);
788 	release_sock(sk2);
789 	return 0;
790 }
791 EXPORT_SYMBOL(inet_accept);
792 
793 /*
794  *	This does both peername and sockname.
795  */
796 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
797 		 int peer)
798 {
799 	struct sock *sk		= sock->sk;
800 	struct inet_sock *inet	= inet_sk(sk);
801 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
802 	int sin_addr_len = sizeof(*sin);
803 
804 	sin->sin_family = AF_INET;
805 	lock_sock(sk);
806 	if (peer) {
807 		if (!inet->inet_dport ||
808 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
809 		     peer == 1)) {
810 			release_sock(sk);
811 			return -ENOTCONN;
812 		}
813 		sin->sin_port = inet->inet_dport;
814 		sin->sin_addr.s_addr = inet->inet_daddr;
815 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
816 				       CGROUP_INET4_GETPEERNAME);
817 	} else {
818 		__be32 addr = inet->inet_rcv_saddr;
819 		if (!addr)
820 			addr = inet->inet_saddr;
821 		sin->sin_port = inet->inet_sport;
822 		sin->sin_addr.s_addr = addr;
823 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
824 				       CGROUP_INET4_GETSOCKNAME);
825 	}
826 	release_sock(sk);
827 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
828 	return sin_addr_len;
829 }
830 EXPORT_SYMBOL(inet_getname);
831 
832 int inet_send_prepare(struct sock *sk)
833 {
834 	sock_rps_record_flow(sk);
835 
836 	/* We may need to bind the socket. */
837 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
838 	    inet_autobind(sk))
839 		return -EAGAIN;
840 
841 	return 0;
842 }
843 EXPORT_SYMBOL_GPL(inet_send_prepare);
844 
845 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
846 {
847 	struct sock *sk = sock->sk;
848 
849 	if (unlikely(inet_send_prepare(sk)))
850 		return -EAGAIN;
851 
852 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
853 			       sk, msg, size);
854 }
855 EXPORT_SYMBOL(inet_sendmsg);
856 
857 void inet_splice_eof(struct socket *sock)
858 {
859 	const struct proto *prot;
860 	struct sock *sk = sock->sk;
861 
862 	if (unlikely(inet_send_prepare(sk)))
863 		return;
864 
865 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
866 	prot = READ_ONCE(sk->sk_prot);
867 	if (prot->splice_eof)
868 		prot->splice_eof(sock);
869 }
870 EXPORT_SYMBOL_GPL(inet_splice_eof);
871 
872 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
873 					  size_t, int, int *));
874 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
875 		 int flags)
876 {
877 	struct sock *sk = sock->sk;
878 	int addr_len = 0;
879 	int err;
880 
881 	if (likely(!(flags & MSG_ERRQUEUE)))
882 		sock_rps_record_flow(sk);
883 
884 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
885 			      sk, msg, size, flags, &addr_len);
886 	if (err >= 0)
887 		msg->msg_namelen = addr_len;
888 	return err;
889 }
890 EXPORT_SYMBOL(inet_recvmsg);
891 
892 int inet_shutdown(struct socket *sock, int how)
893 {
894 	struct sock *sk = sock->sk;
895 	int err = 0;
896 
897 	/* This should really check to make sure
898 	 * the socket is a TCP socket. (WHY AC...)
899 	 */
900 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
901 		       1->2 bit 2 snds.
902 		       2->3 */
903 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
904 		return -EINVAL;
905 
906 	lock_sock(sk);
907 	if (sock->state == SS_CONNECTING) {
908 		if ((1 << sk->sk_state) &
909 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
910 			sock->state = SS_DISCONNECTING;
911 		else
912 			sock->state = SS_CONNECTED;
913 	}
914 
915 	switch (sk->sk_state) {
916 	case TCP_CLOSE:
917 		err = -ENOTCONN;
918 		/* Hack to wake up other listeners, who can poll for
919 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
920 		fallthrough;
921 	default:
922 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
923 		if (sk->sk_prot->shutdown)
924 			sk->sk_prot->shutdown(sk, how);
925 		break;
926 
927 	/* Remaining two branches are temporary solution for missing
928 	 * close() in multithreaded environment. It is _not_ a good idea,
929 	 * but we have no choice until close() is repaired at VFS level.
930 	 */
931 	case TCP_LISTEN:
932 		if (!(how & RCV_SHUTDOWN))
933 			break;
934 		fallthrough;
935 	case TCP_SYN_SENT:
936 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
937 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
938 		break;
939 	}
940 
941 	/* Wake up anyone sleeping in poll. */
942 	sk->sk_state_change(sk);
943 	release_sock(sk);
944 	return err;
945 }
946 EXPORT_SYMBOL(inet_shutdown);
947 
948 /*
949  *	ioctl() calls you can issue on an INET socket. Most of these are
950  *	device configuration and stuff and very rarely used. Some ioctls
951  *	pass on to the socket itself.
952  *
953  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
954  *	loads the devconfigure module does its configuring and unloads it.
955  *	There's a good 20K of config code hanging around the kernel.
956  */
957 
958 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
959 {
960 	struct sock *sk = sock->sk;
961 	int err = 0;
962 	struct net *net = sock_net(sk);
963 	void __user *p = (void __user *)arg;
964 	struct ifreq ifr;
965 	struct rtentry rt;
966 
967 	switch (cmd) {
968 	case SIOCADDRT:
969 	case SIOCDELRT:
970 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
971 			return -EFAULT;
972 		err = ip_rt_ioctl(net, cmd, &rt);
973 		break;
974 	case SIOCRTMSG:
975 		err = -EINVAL;
976 		break;
977 	case SIOCDARP:
978 	case SIOCGARP:
979 	case SIOCSARP:
980 		err = arp_ioctl(net, cmd, (void __user *)arg);
981 		break;
982 	case SIOCGIFADDR:
983 	case SIOCGIFBRDADDR:
984 	case SIOCGIFNETMASK:
985 	case SIOCGIFDSTADDR:
986 	case SIOCGIFPFLAGS:
987 		if (get_user_ifreq(&ifr, NULL, p))
988 			return -EFAULT;
989 		err = devinet_ioctl(net, cmd, &ifr);
990 		if (!err && put_user_ifreq(&ifr, p))
991 			err = -EFAULT;
992 		break;
993 
994 	case SIOCSIFADDR:
995 	case SIOCSIFBRDADDR:
996 	case SIOCSIFNETMASK:
997 	case SIOCSIFDSTADDR:
998 	case SIOCSIFPFLAGS:
999 	case SIOCSIFFLAGS:
1000 		if (get_user_ifreq(&ifr, NULL, p))
1001 			return -EFAULT;
1002 		err = devinet_ioctl(net, cmd, &ifr);
1003 		break;
1004 	default:
1005 		if (sk->sk_prot->ioctl)
1006 			err = sk_ioctl(sk, cmd, (void __user *)arg);
1007 		else
1008 			err = -ENOIOCTLCMD;
1009 		break;
1010 	}
1011 	return err;
1012 }
1013 EXPORT_SYMBOL(inet_ioctl);
1014 
1015 #ifdef CONFIG_COMPAT
1016 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1017 		struct compat_rtentry __user *ur)
1018 {
1019 	compat_uptr_t rtdev;
1020 	struct rtentry rt;
1021 
1022 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1023 			3 * sizeof(struct sockaddr)) ||
1024 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1025 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1026 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1027 	    get_user(rt.rt_window, &ur->rt_window) ||
1028 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1029 	    get_user(rtdev, &ur->rt_dev))
1030 		return -EFAULT;
1031 
1032 	rt.rt_dev = compat_ptr(rtdev);
1033 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1034 }
1035 
1036 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1037 {
1038 	void __user *argp = compat_ptr(arg);
1039 	struct sock *sk = sock->sk;
1040 
1041 	switch (cmd) {
1042 	case SIOCADDRT:
1043 	case SIOCDELRT:
1044 		return inet_compat_routing_ioctl(sk, cmd, argp);
1045 	default:
1046 		if (!sk->sk_prot->compat_ioctl)
1047 			return -ENOIOCTLCMD;
1048 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1049 	}
1050 }
1051 #endif /* CONFIG_COMPAT */
1052 
1053 const struct proto_ops inet_stream_ops = {
1054 	.family		   = PF_INET,
1055 	.owner		   = THIS_MODULE,
1056 	.release	   = inet_release,
1057 	.bind		   = inet_bind,
1058 	.connect	   = inet_stream_connect,
1059 	.socketpair	   = sock_no_socketpair,
1060 	.accept		   = inet_accept,
1061 	.getname	   = inet_getname,
1062 	.poll		   = tcp_poll,
1063 	.ioctl		   = inet_ioctl,
1064 	.gettstamp	   = sock_gettstamp,
1065 	.listen		   = inet_listen,
1066 	.shutdown	   = inet_shutdown,
1067 	.setsockopt	   = sock_common_setsockopt,
1068 	.getsockopt	   = sock_common_getsockopt,
1069 	.sendmsg	   = inet_sendmsg,
1070 	.recvmsg	   = inet_recvmsg,
1071 #ifdef CONFIG_MMU
1072 	.mmap		   = tcp_mmap,
1073 #endif
1074 	.splice_eof	   = inet_splice_eof,
1075 	.splice_read	   = tcp_splice_read,
1076 	.read_sock	   = tcp_read_sock,
1077 	.read_skb	   = tcp_read_skb,
1078 	.sendmsg_locked    = tcp_sendmsg_locked,
1079 	.peek_len	   = tcp_peek_len,
1080 #ifdef CONFIG_COMPAT
1081 	.compat_ioctl	   = inet_compat_ioctl,
1082 #endif
1083 	.set_rcvlowat	   = tcp_set_rcvlowat,
1084 };
1085 EXPORT_SYMBOL(inet_stream_ops);
1086 
1087 const struct proto_ops inet_dgram_ops = {
1088 	.family		   = PF_INET,
1089 	.owner		   = THIS_MODULE,
1090 	.release	   = inet_release,
1091 	.bind		   = inet_bind,
1092 	.connect	   = inet_dgram_connect,
1093 	.socketpair	   = sock_no_socketpair,
1094 	.accept		   = sock_no_accept,
1095 	.getname	   = inet_getname,
1096 	.poll		   = udp_poll,
1097 	.ioctl		   = inet_ioctl,
1098 	.gettstamp	   = sock_gettstamp,
1099 	.listen		   = sock_no_listen,
1100 	.shutdown	   = inet_shutdown,
1101 	.setsockopt	   = sock_common_setsockopt,
1102 	.getsockopt	   = sock_common_getsockopt,
1103 	.sendmsg	   = inet_sendmsg,
1104 	.read_skb	   = udp_read_skb,
1105 	.recvmsg	   = inet_recvmsg,
1106 	.mmap		   = sock_no_mmap,
1107 	.splice_eof	   = inet_splice_eof,
1108 	.set_peek_off	   = sk_set_peek_off,
1109 #ifdef CONFIG_COMPAT
1110 	.compat_ioctl	   = inet_compat_ioctl,
1111 #endif
1112 };
1113 EXPORT_SYMBOL(inet_dgram_ops);
1114 
1115 /*
1116  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1117  * udp_poll
1118  */
1119 static const struct proto_ops inet_sockraw_ops = {
1120 	.family		   = PF_INET,
1121 	.owner		   = THIS_MODULE,
1122 	.release	   = inet_release,
1123 	.bind		   = inet_bind,
1124 	.connect	   = inet_dgram_connect,
1125 	.socketpair	   = sock_no_socketpair,
1126 	.accept		   = sock_no_accept,
1127 	.getname	   = inet_getname,
1128 	.poll		   = datagram_poll,
1129 	.ioctl		   = inet_ioctl,
1130 	.gettstamp	   = sock_gettstamp,
1131 	.listen		   = sock_no_listen,
1132 	.shutdown	   = inet_shutdown,
1133 	.setsockopt	   = sock_common_setsockopt,
1134 	.getsockopt	   = sock_common_getsockopt,
1135 	.sendmsg	   = inet_sendmsg,
1136 	.recvmsg	   = inet_recvmsg,
1137 	.mmap		   = sock_no_mmap,
1138 	.splice_eof	   = inet_splice_eof,
1139 #ifdef CONFIG_COMPAT
1140 	.compat_ioctl	   = inet_compat_ioctl,
1141 #endif
1142 };
1143 
1144 static const struct net_proto_family inet_family_ops = {
1145 	.family = PF_INET,
1146 	.create = inet_create,
1147 	.owner	= THIS_MODULE,
1148 };
1149 
1150 /* Upon startup we insert all the elements in inetsw_array[] into
1151  * the linked list inetsw.
1152  */
1153 static struct inet_protosw inetsw_array[] =
1154 {
1155 	{
1156 		.type =       SOCK_STREAM,
1157 		.protocol =   IPPROTO_TCP,
1158 		.prot =       &tcp_prot,
1159 		.ops =        &inet_stream_ops,
1160 		.flags =      INET_PROTOSW_PERMANENT |
1161 			      INET_PROTOSW_ICSK,
1162 	},
1163 
1164 	{
1165 		.type =       SOCK_DGRAM,
1166 		.protocol =   IPPROTO_UDP,
1167 		.prot =       &udp_prot,
1168 		.ops =        &inet_dgram_ops,
1169 		.flags =      INET_PROTOSW_PERMANENT,
1170        },
1171 
1172        {
1173 		.type =       SOCK_DGRAM,
1174 		.protocol =   IPPROTO_ICMP,
1175 		.prot =       &ping_prot,
1176 		.ops =        &inet_sockraw_ops,
1177 		.flags =      INET_PROTOSW_REUSE,
1178        },
1179 
1180        {
1181 	       .type =       SOCK_RAW,
1182 	       .protocol =   IPPROTO_IP,	/* wild card */
1183 	       .prot =       &raw_prot,
1184 	       .ops =        &inet_sockraw_ops,
1185 	       .flags =      INET_PROTOSW_REUSE,
1186        }
1187 };
1188 
1189 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1190 
1191 void inet_register_protosw(struct inet_protosw *p)
1192 {
1193 	struct list_head *lh;
1194 	struct inet_protosw *answer;
1195 	int protocol = p->protocol;
1196 	struct list_head *last_perm;
1197 
1198 	spin_lock_bh(&inetsw_lock);
1199 
1200 	if (p->type >= SOCK_MAX)
1201 		goto out_illegal;
1202 
1203 	/* If we are trying to override a permanent protocol, bail. */
1204 	last_perm = &inetsw[p->type];
1205 	list_for_each(lh, &inetsw[p->type]) {
1206 		answer = list_entry(lh, struct inet_protosw, list);
1207 		/* Check only the non-wild match. */
1208 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1209 			break;
1210 		if (protocol == answer->protocol)
1211 			goto out_permanent;
1212 		last_perm = lh;
1213 	}
1214 
1215 	/* Add the new entry after the last permanent entry if any, so that
1216 	 * the new entry does not override a permanent entry when matched with
1217 	 * a wild-card protocol. But it is allowed to override any existing
1218 	 * non-permanent entry.  This means that when we remove this entry, the
1219 	 * system automatically returns to the old behavior.
1220 	 */
1221 	list_add_rcu(&p->list, last_perm);
1222 out:
1223 	spin_unlock_bh(&inetsw_lock);
1224 
1225 	return;
1226 
1227 out_permanent:
1228 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1229 	goto out;
1230 
1231 out_illegal:
1232 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1233 	       p->type);
1234 	goto out;
1235 }
1236 EXPORT_SYMBOL(inet_register_protosw);
1237 
1238 void inet_unregister_protosw(struct inet_protosw *p)
1239 {
1240 	if (INET_PROTOSW_PERMANENT & p->flags) {
1241 		pr_err("Attempt to unregister permanent protocol %d\n",
1242 		       p->protocol);
1243 	} else {
1244 		spin_lock_bh(&inetsw_lock);
1245 		list_del_rcu(&p->list);
1246 		spin_unlock_bh(&inetsw_lock);
1247 
1248 		synchronize_net();
1249 	}
1250 }
1251 EXPORT_SYMBOL(inet_unregister_protosw);
1252 
1253 static int inet_sk_reselect_saddr(struct sock *sk)
1254 {
1255 	struct inet_sock *inet = inet_sk(sk);
1256 	__be32 old_saddr = inet->inet_saddr;
1257 	__be32 daddr = inet->inet_daddr;
1258 	struct flowi4 *fl4;
1259 	struct rtable *rt;
1260 	__be32 new_saddr;
1261 	struct ip_options_rcu *inet_opt;
1262 	int err;
1263 
1264 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1265 					     lockdep_sock_is_held(sk));
1266 	if (inet_opt && inet_opt->opt.srr)
1267 		daddr = inet_opt->opt.faddr;
1268 
1269 	/* Query new route. */
1270 	fl4 = &inet->cork.fl.u.ip4;
1271 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1272 			      sk->sk_protocol, inet->inet_sport,
1273 			      inet->inet_dport, sk);
1274 	if (IS_ERR(rt))
1275 		return PTR_ERR(rt);
1276 
1277 	new_saddr = fl4->saddr;
1278 
1279 	if (new_saddr == old_saddr) {
1280 		sk_setup_caps(sk, &rt->dst);
1281 		return 0;
1282 	}
1283 
1284 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1285 	if (err) {
1286 		ip_rt_put(rt);
1287 		return err;
1288 	}
1289 
1290 	sk_setup_caps(sk, &rt->dst);
1291 
1292 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1293 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1294 			__func__, &old_saddr, &new_saddr);
1295 	}
1296 
1297 	/*
1298 	 * XXX The only one ugly spot where we need to
1299 	 * XXX really change the sockets identity after
1300 	 * XXX it has entered the hashes. -DaveM
1301 	 *
1302 	 * Besides that, it does not check for connection
1303 	 * uniqueness. Wait for troubles.
1304 	 */
1305 	return __sk_prot_rehash(sk);
1306 }
1307 
1308 int inet_sk_rebuild_header(struct sock *sk)
1309 {
1310 	struct inet_sock *inet = inet_sk(sk);
1311 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1312 	__be32 daddr;
1313 	struct ip_options_rcu *inet_opt;
1314 	struct flowi4 *fl4;
1315 	int err;
1316 
1317 	/* Route is OK, nothing to do. */
1318 	if (rt)
1319 		return 0;
1320 
1321 	/* Reroute. */
1322 	rcu_read_lock();
1323 	inet_opt = rcu_dereference(inet->inet_opt);
1324 	daddr = inet->inet_daddr;
1325 	if (inet_opt && inet_opt->opt.srr)
1326 		daddr = inet_opt->opt.faddr;
1327 	rcu_read_unlock();
1328 	fl4 = &inet->cork.fl.u.ip4;
1329 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1330 				   inet->inet_dport, inet->inet_sport,
1331 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1332 				   sk->sk_bound_dev_if);
1333 	if (!IS_ERR(rt)) {
1334 		err = 0;
1335 		sk_setup_caps(sk, &rt->dst);
1336 	} else {
1337 		err = PTR_ERR(rt);
1338 
1339 		/* Routing failed... */
1340 		sk->sk_route_caps = 0;
1341 		/*
1342 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1343 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1344 		 */
1345 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1346 		    sk->sk_state != TCP_SYN_SENT ||
1347 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1348 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1349 			WRITE_ONCE(sk->sk_err_soft, -err);
1350 	}
1351 
1352 	return err;
1353 }
1354 EXPORT_SYMBOL(inet_sk_rebuild_header);
1355 
1356 void inet_sk_set_state(struct sock *sk, int state)
1357 {
1358 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1359 	sk->sk_state = state;
1360 }
1361 EXPORT_SYMBOL(inet_sk_set_state);
1362 
1363 void inet_sk_state_store(struct sock *sk, int newstate)
1364 {
1365 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1366 	smp_store_release(&sk->sk_state, newstate);
1367 }
1368 
1369 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1370 				 netdev_features_t features)
1371 {
1372 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1373 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1374 	const struct net_offload *ops;
1375 	unsigned int offset = 0;
1376 	struct iphdr *iph;
1377 	int proto, tot_len;
1378 	int nhoff;
1379 	int ihl;
1380 	int id;
1381 
1382 	skb_reset_network_header(skb);
1383 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1384 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1385 		goto out;
1386 
1387 	iph = ip_hdr(skb);
1388 	ihl = iph->ihl * 4;
1389 	if (ihl < sizeof(*iph))
1390 		goto out;
1391 
1392 	id = ntohs(iph->id);
1393 	proto = iph->protocol;
1394 
1395 	/* Warning: after this point, iph might be no longer valid */
1396 	if (unlikely(!pskb_may_pull(skb, ihl)))
1397 		goto out;
1398 	__skb_pull(skb, ihl);
1399 
1400 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1401 	if (encap)
1402 		features &= skb->dev->hw_enc_features;
1403 	SKB_GSO_CB(skb)->encap_level += ihl;
1404 
1405 	skb_reset_transport_header(skb);
1406 
1407 	segs = ERR_PTR(-EPROTONOSUPPORT);
1408 
1409 	if (!skb->encapsulation || encap) {
1410 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1411 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1412 
1413 		/* fixed ID is invalid if DF bit is not set */
1414 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1415 			goto out;
1416 	}
1417 
1418 	ops = rcu_dereference(inet_offloads[proto]);
1419 	if (likely(ops && ops->callbacks.gso_segment)) {
1420 		segs = ops->callbacks.gso_segment(skb, features);
1421 		if (!segs)
1422 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1423 	}
1424 
1425 	if (IS_ERR_OR_NULL(segs))
1426 		goto out;
1427 
1428 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1429 
1430 	skb = segs;
1431 	do {
1432 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1433 		if (udpfrag) {
1434 			iph->frag_off = htons(offset >> 3);
1435 			if (skb->next)
1436 				iph->frag_off |= htons(IP_MF);
1437 			offset += skb->len - nhoff - ihl;
1438 			tot_len = skb->len - nhoff;
1439 		} else if (skb_is_gso(skb)) {
1440 			if (!fixedid) {
1441 				iph->id = htons(id);
1442 				id += skb_shinfo(skb)->gso_segs;
1443 			}
1444 
1445 			if (gso_partial)
1446 				tot_len = skb_shinfo(skb)->gso_size +
1447 					  SKB_GSO_CB(skb)->data_offset +
1448 					  skb->head - (unsigned char *)iph;
1449 			else
1450 				tot_len = skb->len - nhoff;
1451 		} else {
1452 			if (!fixedid)
1453 				iph->id = htons(id++);
1454 			tot_len = skb->len - nhoff;
1455 		}
1456 		iph->tot_len = htons(tot_len);
1457 		ip_send_check(iph);
1458 		if (encap)
1459 			skb_reset_inner_headers(skb);
1460 		skb->network_header = (u8 *)iph - skb->head;
1461 		skb_reset_mac_len(skb);
1462 	} while ((skb = skb->next));
1463 
1464 out:
1465 	return segs;
1466 }
1467 
1468 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1469 					netdev_features_t features)
1470 {
1471 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1472 		return ERR_PTR(-EINVAL);
1473 
1474 	return inet_gso_segment(skb, features);
1475 }
1476 
1477 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1478 {
1479 	const struct net_offload *ops;
1480 	struct sk_buff *pp = NULL;
1481 	const struct iphdr *iph;
1482 	struct sk_buff *p;
1483 	unsigned int hlen;
1484 	unsigned int off;
1485 	unsigned int id;
1486 	int flush = 1;
1487 	int proto;
1488 
1489 	off = skb_gro_offset(skb);
1490 	hlen = off + sizeof(*iph);
1491 	iph = skb_gro_header(skb, hlen, off);
1492 	if (unlikely(!iph))
1493 		goto out;
1494 
1495 	proto = iph->protocol;
1496 
1497 	ops = rcu_dereference(inet_offloads[proto]);
1498 	if (!ops || !ops->callbacks.gro_receive)
1499 		goto out;
1500 
1501 	if (*(u8 *)iph != 0x45)
1502 		goto out;
1503 
1504 	if (ip_is_fragment(iph))
1505 		goto out;
1506 
1507 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1508 		goto out;
1509 
1510 	NAPI_GRO_CB(skb)->proto = proto;
1511 	id = ntohl(*(__be32 *)&iph->id);
1512 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1513 	id >>= 16;
1514 
1515 	list_for_each_entry(p, head, list) {
1516 		struct iphdr *iph2;
1517 		u16 flush_id;
1518 
1519 		if (!NAPI_GRO_CB(p)->same_flow)
1520 			continue;
1521 
1522 		iph2 = (struct iphdr *)(p->data + off);
1523 		/* The above works because, with the exception of the top
1524 		 * (inner most) layer, we only aggregate pkts with the same
1525 		 * hdr length so all the hdrs we'll need to verify will start
1526 		 * at the same offset.
1527 		 */
1528 		if ((iph->protocol ^ iph2->protocol) |
1529 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1530 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1531 			NAPI_GRO_CB(p)->same_flow = 0;
1532 			continue;
1533 		}
1534 
1535 		/* All fields must match except length and checksum. */
1536 		NAPI_GRO_CB(p)->flush |=
1537 			(iph->ttl ^ iph2->ttl) |
1538 			(iph->tos ^ iph2->tos) |
1539 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1540 
1541 		NAPI_GRO_CB(p)->flush |= flush;
1542 
1543 		/* We need to store of the IP ID check to be included later
1544 		 * when we can verify that this packet does in fact belong
1545 		 * to a given flow.
1546 		 */
1547 		flush_id = (u16)(id - ntohs(iph2->id));
1548 
1549 		/* This bit of code makes it much easier for us to identify
1550 		 * the cases where we are doing atomic vs non-atomic IP ID
1551 		 * checks.  Specifically an atomic check can return IP ID
1552 		 * values 0 - 0xFFFF, while a non-atomic check can only
1553 		 * return 0 or 0xFFFF.
1554 		 */
1555 		if (!NAPI_GRO_CB(p)->is_atomic ||
1556 		    !(iph->frag_off & htons(IP_DF))) {
1557 			flush_id ^= NAPI_GRO_CB(p)->count;
1558 			flush_id = flush_id ? 0xFFFF : 0;
1559 		}
1560 
1561 		/* If the previous IP ID value was based on an atomic
1562 		 * datagram we can overwrite the value and ignore it.
1563 		 */
1564 		if (NAPI_GRO_CB(skb)->is_atomic)
1565 			NAPI_GRO_CB(p)->flush_id = flush_id;
1566 		else
1567 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1568 	}
1569 
1570 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1571 	NAPI_GRO_CB(skb)->flush |= flush;
1572 	skb_set_network_header(skb, off);
1573 	/* The above will be needed by the transport layer if there is one
1574 	 * immediately following this IP hdr.
1575 	 */
1576 	NAPI_GRO_CB(skb)->inner_network_offset = off;
1577 
1578 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1579 	 * as we already checked checksum over ipv4 header was 0
1580 	 */
1581 	skb_gro_pull(skb, sizeof(*iph));
1582 	skb_set_transport_header(skb, skb_gro_offset(skb));
1583 
1584 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1585 				       ops->callbacks.gro_receive, head, skb);
1586 
1587 out:
1588 	skb_gro_flush_final(skb, pp, flush);
1589 
1590 	return pp;
1591 }
1592 
1593 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1594 					struct sk_buff *skb)
1595 {
1596 	if (NAPI_GRO_CB(skb)->encap_mark) {
1597 		NAPI_GRO_CB(skb)->flush = 1;
1598 		return NULL;
1599 	}
1600 
1601 	NAPI_GRO_CB(skb)->encap_mark = 1;
1602 
1603 	return inet_gro_receive(head, skb);
1604 }
1605 
1606 #define SECONDS_PER_DAY	86400
1607 
1608 /* inet_current_timestamp - Return IP network timestamp
1609  *
1610  * Return milliseconds since midnight in network byte order.
1611  */
1612 __be32 inet_current_timestamp(void)
1613 {
1614 	u32 secs;
1615 	u32 msecs;
1616 	struct timespec64 ts;
1617 
1618 	ktime_get_real_ts64(&ts);
1619 
1620 	/* Get secs since midnight. */
1621 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1622 	/* Convert to msecs. */
1623 	msecs = secs * MSEC_PER_SEC;
1624 	/* Convert nsec to msec. */
1625 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1626 
1627 	/* Convert to network byte order. */
1628 	return htonl(msecs);
1629 }
1630 EXPORT_SYMBOL(inet_current_timestamp);
1631 
1632 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1633 {
1634 	unsigned int family = READ_ONCE(sk->sk_family);
1635 
1636 	if (family == AF_INET)
1637 		return ip_recv_error(sk, msg, len, addr_len);
1638 #if IS_ENABLED(CONFIG_IPV6)
1639 	if (family == AF_INET6)
1640 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1641 #endif
1642 	return -EINVAL;
1643 }
1644 EXPORT_SYMBOL(inet_recv_error);
1645 
1646 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1647 {
1648 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1649 	const struct net_offload *ops;
1650 	__be16 totlen = iph->tot_len;
1651 	int proto = iph->protocol;
1652 	int err = -ENOSYS;
1653 
1654 	if (skb->encapsulation) {
1655 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1656 		skb_set_inner_network_header(skb, nhoff);
1657 	}
1658 
1659 	iph_set_totlen(iph, skb->len - nhoff);
1660 	csum_replace2(&iph->check, totlen, iph->tot_len);
1661 
1662 	ops = rcu_dereference(inet_offloads[proto]);
1663 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1664 		goto out;
1665 
1666 	/* Only need to add sizeof(*iph) to get to the next hdr below
1667 	 * because any hdr with option will have been flushed in
1668 	 * inet_gro_receive().
1669 	 */
1670 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1671 			      tcp4_gro_complete, udp4_gro_complete,
1672 			      skb, nhoff + sizeof(*iph));
1673 
1674 out:
1675 	return err;
1676 }
1677 
1678 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1679 {
1680 	skb->encapsulation = 1;
1681 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1682 	return inet_gro_complete(skb, nhoff);
1683 }
1684 
1685 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1686 			 unsigned short type, unsigned char protocol,
1687 			 struct net *net)
1688 {
1689 	struct socket *sock;
1690 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1691 
1692 	if (rc == 0) {
1693 		*sk = sock->sk;
1694 		(*sk)->sk_allocation = GFP_ATOMIC;
1695 		(*sk)->sk_use_task_frag = false;
1696 		/*
1697 		 * Unhash it so that IP input processing does not even see it,
1698 		 * we do not wish this socket to see incoming packets.
1699 		 */
1700 		(*sk)->sk_prot->unhash(*sk);
1701 	}
1702 	return rc;
1703 }
1704 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1705 
1706 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1707 {
1708 	unsigned long res = 0;
1709 	int i;
1710 
1711 	for_each_possible_cpu(i)
1712 		res += snmp_get_cpu_field(mib, i, offt);
1713 	return res;
1714 }
1715 EXPORT_SYMBOL_GPL(snmp_fold_field);
1716 
1717 #if BITS_PER_LONG==32
1718 
1719 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1720 			 size_t syncp_offset)
1721 {
1722 	void *bhptr;
1723 	struct u64_stats_sync *syncp;
1724 	u64 v;
1725 	unsigned int start;
1726 
1727 	bhptr = per_cpu_ptr(mib, cpu);
1728 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1729 	do {
1730 		start = u64_stats_fetch_begin(syncp);
1731 		v = *(((u64 *)bhptr) + offt);
1732 	} while (u64_stats_fetch_retry(syncp, start));
1733 
1734 	return v;
1735 }
1736 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1737 
1738 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1739 {
1740 	u64 res = 0;
1741 	int cpu;
1742 
1743 	for_each_possible_cpu(cpu) {
1744 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1745 	}
1746 	return res;
1747 }
1748 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1749 #endif
1750 
1751 #ifdef CONFIG_IP_MULTICAST
1752 static const struct net_protocol igmp_protocol = {
1753 	.handler =	igmp_rcv,
1754 };
1755 #endif
1756 
1757 static const struct net_protocol tcp_protocol = {
1758 	.handler	=	tcp_v4_rcv,
1759 	.err_handler	=	tcp_v4_err,
1760 	.no_policy	=	1,
1761 	.icmp_strict_tag_validation = 1,
1762 };
1763 
1764 static const struct net_protocol udp_protocol = {
1765 	.handler =	udp_rcv,
1766 	.err_handler =	udp_err,
1767 	.no_policy =	1,
1768 };
1769 
1770 static const struct net_protocol icmp_protocol = {
1771 	.handler =	icmp_rcv,
1772 	.err_handler =	icmp_err,
1773 	.no_policy =	1,
1774 };
1775 
1776 static __net_init int ipv4_mib_init_net(struct net *net)
1777 {
1778 	int i;
1779 
1780 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1781 	if (!net->mib.tcp_statistics)
1782 		goto err_tcp_mib;
1783 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1784 	if (!net->mib.ip_statistics)
1785 		goto err_ip_mib;
1786 
1787 	for_each_possible_cpu(i) {
1788 		struct ipstats_mib *af_inet_stats;
1789 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1790 		u64_stats_init(&af_inet_stats->syncp);
1791 	}
1792 
1793 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1794 	if (!net->mib.net_statistics)
1795 		goto err_net_mib;
1796 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1797 	if (!net->mib.udp_statistics)
1798 		goto err_udp_mib;
1799 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1800 	if (!net->mib.udplite_statistics)
1801 		goto err_udplite_mib;
1802 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1803 	if (!net->mib.icmp_statistics)
1804 		goto err_icmp_mib;
1805 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1806 					      GFP_KERNEL);
1807 	if (!net->mib.icmpmsg_statistics)
1808 		goto err_icmpmsg_mib;
1809 
1810 	tcp_mib_init(net);
1811 	return 0;
1812 
1813 err_icmpmsg_mib:
1814 	free_percpu(net->mib.icmp_statistics);
1815 err_icmp_mib:
1816 	free_percpu(net->mib.udplite_statistics);
1817 err_udplite_mib:
1818 	free_percpu(net->mib.udp_statistics);
1819 err_udp_mib:
1820 	free_percpu(net->mib.net_statistics);
1821 err_net_mib:
1822 	free_percpu(net->mib.ip_statistics);
1823 err_ip_mib:
1824 	free_percpu(net->mib.tcp_statistics);
1825 err_tcp_mib:
1826 	return -ENOMEM;
1827 }
1828 
1829 static __net_exit void ipv4_mib_exit_net(struct net *net)
1830 {
1831 	kfree(net->mib.icmpmsg_statistics);
1832 	free_percpu(net->mib.icmp_statistics);
1833 	free_percpu(net->mib.udplite_statistics);
1834 	free_percpu(net->mib.udp_statistics);
1835 	free_percpu(net->mib.net_statistics);
1836 	free_percpu(net->mib.ip_statistics);
1837 	free_percpu(net->mib.tcp_statistics);
1838 #ifdef CONFIG_MPTCP
1839 	/* allocated on demand, see mptcp_init_sock() */
1840 	free_percpu(net->mib.mptcp_statistics);
1841 #endif
1842 }
1843 
1844 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1845 	.init = ipv4_mib_init_net,
1846 	.exit = ipv4_mib_exit_net,
1847 };
1848 
1849 static int __init init_ipv4_mibs(void)
1850 {
1851 	return register_pernet_subsys(&ipv4_mib_ops);
1852 }
1853 
1854 static __net_init int inet_init_net(struct net *net)
1855 {
1856 	/*
1857 	 * Set defaults for local port range
1858 	 */
1859 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1860 	net->ipv4.ip_local_ports.range[0] =  32768;
1861 	net->ipv4.ip_local_ports.range[1] =  60999;
1862 
1863 	seqlock_init(&net->ipv4.ping_group_range.lock);
1864 	/*
1865 	 * Sane defaults - nobody may create ping sockets.
1866 	 * Boot scripts should set this to distro-specific group.
1867 	 */
1868 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1869 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1870 
1871 	/* Default values for sysctl-controlled parameters.
1872 	 * We set them here, in case sysctl is not compiled.
1873 	 */
1874 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1875 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1876 	net->ipv4.sysctl_ip_dynaddr = 0;
1877 	net->ipv4.sysctl_ip_early_demux = 1;
1878 	net->ipv4.sysctl_udp_early_demux = 1;
1879 	net->ipv4.sysctl_tcp_early_demux = 1;
1880 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1881 #ifdef CONFIG_SYSCTL
1882 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1883 #endif
1884 
1885 	/* Some igmp sysctl, whose values are always used */
1886 	net->ipv4.sysctl_igmp_max_memberships = 20;
1887 	net->ipv4.sysctl_igmp_max_msf = 10;
1888 	/* IGMP reports for link-local multicast groups are enabled by default */
1889 	net->ipv4.sysctl_igmp_llm_reports = 1;
1890 	net->ipv4.sysctl_igmp_qrv = 2;
1891 
1892 	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1893 
1894 	return 0;
1895 }
1896 
1897 static __net_initdata struct pernet_operations af_inet_ops = {
1898 	.init = inet_init_net,
1899 };
1900 
1901 static int __init init_inet_pernet_ops(void)
1902 {
1903 	return register_pernet_subsys(&af_inet_ops);
1904 }
1905 
1906 static int ipv4_proc_init(void);
1907 
1908 /*
1909  *	IP protocol layer initialiser
1910  */
1911 
1912 static struct packet_offload ip_packet_offload __read_mostly = {
1913 	.type = cpu_to_be16(ETH_P_IP),
1914 	.callbacks = {
1915 		.gso_segment = inet_gso_segment,
1916 		.gro_receive = inet_gro_receive,
1917 		.gro_complete = inet_gro_complete,
1918 	},
1919 };
1920 
1921 static const struct net_offload ipip_offload = {
1922 	.callbacks = {
1923 		.gso_segment	= ipip_gso_segment,
1924 		.gro_receive	= ipip_gro_receive,
1925 		.gro_complete	= ipip_gro_complete,
1926 	},
1927 };
1928 
1929 static int __init ipip_offload_init(void)
1930 {
1931 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1932 }
1933 
1934 static int __init ipv4_offload_init(void)
1935 {
1936 	/*
1937 	 * Add offloads
1938 	 */
1939 	if (udpv4_offload_init() < 0)
1940 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1941 	if (tcpv4_offload_init() < 0)
1942 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1943 	if (ipip_offload_init() < 0)
1944 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1945 
1946 	dev_add_offload(&ip_packet_offload);
1947 	return 0;
1948 }
1949 
1950 fs_initcall(ipv4_offload_init);
1951 
1952 static struct packet_type ip_packet_type __read_mostly = {
1953 	.type = cpu_to_be16(ETH_P_IP),
1954 	.func = ip_rcv,
1955 	.list_func = ip_list_rcv,
1956 };
1957 
1958 static int __init inet_init(void)
1959 {
1960 	struct inet_protosw *q;
1961 	struct list_head *r;
1962 	int rc;
1963 
1964 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1965 
1966 	raw_hashinfo_init(&raw_v4_hashinfo);
1967 
1968 	rc = proto_register(&tcp_prot, 1);
1969 	if (rc)
1970 		goto out;
1971 
1972 	rc = proto_register(&udp_prot, 1);
1973 	if (rc)
1974 		goto out_unregister_tcp_proto;
1975 
1976 	rc = proto_register(&raw_prot, 1);
1977 	if (rc)
1978 		goto out_unregister_udp_proto;
1979 
1980 	rc = proto_register(&ping_prot, 1);
1981 	if (rc)
1982 		goto out_unregister_raw_proto;
1983 
1984 	/*
1985 	 *	Tell SOCKET that we are alive...
1986 	 */
1987 
1988 	(void)sock_register(&inet_family_ops);
1989 
1990 #ifdef CONFIG_SYSCTL
1991 	ip_static_sysctl_init();
1992 #endif
1993 
1994 	/*
1995 	 *	Add all the base protocols.
1996 	 */
1997 
1998 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1999 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
2000 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
2001 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
2002 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
2003 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
2004 #ifdef CONFIG_IP_MULTICAST
2005 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
2006 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2007 #endif
2008 
2009 	/* Register the socket-side information for inet_create. */
2010 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2011 		INIT_LIST_HEAD(r);
2012 
2013 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2014 		inet_register_protosw(q);
2015 
2016 	/*
2017 	 *	Set the ARP module up
2018 	 */
2019 
2020 	arp_init();
2021 
2022 	/*
2023 	 *	Set the IP module up
2024 	 */
2025 
2026 	ip_init();
2027 
2028 	/* Initialise per-cpu ipv4 mibs */
2029 	if (init_ipv4_mibs())
2030 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2031 
2032 	/* Setup TCP slab cache for open requests. */
2033 	tcp_init();
2034 
2035 	/* Setup UDP memory threshold */
2036 	udp_init();
2037 
2038 	/* Add UDP-Lite (RFC 3828) */
2039 	udplite4_register();
2040 
2041 	raw_init();
2042 
2043 	ping_init();
2044 
2045 	/*
2046 	 *	Set the ICMP layer up
2047 	 */
2048 
2049 	if (icmp_init() < 0)
2050 		panic("Failed to create the ICMP control socket.\n");
2051 
2052 	/*
2053 	 *	Initialise the multicast router
2054 	 */
2055 #if defined(CONFIG_IP_MROUTE)
2056 	if (ip_mr_init())
2057 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2058 #endif
2059 
2060 	if (init_inet_pernet_ops())
2061 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2062 
2063 	ipv4_proc_init();
2064 
2065 	ipfrag_init();
2066 
2067 	dev_add_pack(&ip_packet_type);
2068 
2069 	ip_tunnel_core_init();
2070 
2071 	rc = 0;
2072 out:
2073 	return rc;
2074 out_unregister_raw_proto:
2075 	proto_unregister(&raw_prot);
2076 out_unregister_udp_proto:
2077 	proto_unregister(&udp_prot);
2078 out_unregister_tcp_proto:
2079 	proto_unregister(&tcp_prot);
2080 	goto out;
2081 }
2082 
2083 fs_initcall(inet_init);
2084 
2085 /* ------------------------------------------------------------------------ */
2086 
2087 #ifdef CONFIG_PROC_FS
2088 static int __init ipv4_proc_init(void)
2089 {
2090 	int rc = 0;
2091 
2092 	if (raw_proc_init())
2093 		goto out_raw;
2094 	if (tcp4_proc_init())
2095 		goto out_tcp;
2096 	if (udp4_proc_init())
2097 		goto out_udp;
2098 	if (ping_proc_init())
2099 		goto out_ping;
2100 	if (ip_misc_proc_init())
2101 		goto out_misc;
2102 out:
2103 	return rc;
2104 out_misc:
2105 	ping_proc_exit();
2106 out_ping:
2107 	udp4_proc_exit();
2108 out_udp:
2109 	tcp4_proc_exit();
2110 out_tcp:
2111 	raw_proc_exit();
2112 out_raw:
2113 	rc = -ENOMEM;
2114 	goto out;
2115 }
2116 
2117 #else /* CONFIG_PROC_FS */
2118 static int __init ipv4_proc_init(void)
2119 {
2120 	return 0;
2121 }
2122 #endif /* CONFIG_PROC_FS */
2123