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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/tcp.h>
103 #include <net/udp.h>
104 #include <net/udplite.h>
105 #include <net/ping.h>
106 #include <linux/skbuff.h>
107 #include <net/sock.h>
108 #include <net/raw.h>
109 #include <net/icmp.h>
110 #include <net/inet_common.h>
111 #include <net/ip_tunnels.h>
112 #include <net/xfrm.h>
113 #include <net/net_namespace.h>
114 #include <net/secure_seq.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
117 #endif
118 #include <net/l3mdev.h>
119 #include <net/compat.h>
120 #ifdef CONFIG_LOWPOWER_PROTOCOL
121 #include <net/lowpower_protocol.h>
122 #endif /* CONFIG_LOWPOWER_PROTOCOL */
123 
124 #include <trace/events/sock.h>
125 
126 /* The inetsw table contains everything that inet_create needs to
127  * build a new socket.
128  */
129 static struct list_head inetsw[SOCK_MAX];
130 static DEFINE_SPINLOCK(inetsw_lock);
131 
132 /* New destruction routine */
133 
inet_sock_destruct(struct sock * sk)134 void inet_sock_destruct(struct sock *sk)
135 {
136 	struct inet_sock *inet = inet_sk(sk);
137 
138 	__skb_queue_purge(&sk->sk_receive_queue);
139 	if (sk->sk_rx_skb_cache) {
140 		__kfree_skb(sk->sk_rx_skb_cache);
141 		sk->sk_rx_skb_cache = NULL;
142 	}
143 	__skb_queue_purge(&sk->sk_error_queue);
144 
145 	sk_mem_reclaim(sk);
146 
147 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
148 		pr_err("Attempt to release TCP socket in state %d %p\n",
149 		       sk->sk_state, sk);
150 		return;
151 	}
152 	if (!sock_flag(sk, SOCK_DEAD)) {
153 		pr_err("Attempt to release alive inet socket %p\n", sk);
154 		return;
155 	}
156 
157 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
158 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
159 	WARN_ON(sk->sk_wmem_queued);
160 	WARN_ON(sk->sk_forward_alloc);
161 
162 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
163 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
164 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
165 	sk_refcnt_debug_dec(sk);
166 }
167 EXPORT_SYMBOL(inet_sock_destruct);
168 
169 /*
170  *	The routines beyond this point handle the behaviour of an AF_INET
171  *	socket object. Mostly it punts to the subprotocols of IP to do
172  *	the work.
173  */
174 
175 /*
176  *	Automatically bind an unbound socket.
177  */
178 
inet_autobind(struct sock * sk)179 static int inet_autobind(struct sock *sk)
180 {
181 	struct inet_sock *inet;
182 	/* We may need to bind the socket. */
183 	lock_sock(sk);
184 	inet = inet_sk(sk);
185 	if (!inet->inet_num) {
186 		if (sk->sk_prot->get_port(sk, 0)) {
187 			release_sock(sk);
188 			return -EAGAIN;
189 		}
190 		inet->inet_sport = htons(inet->inet_num);
191 	}
192 	release_sock(sk);
193 	return 0;
194 }
195 
196 /*
197  *	Move a socket into listening state.
198  */
inet_listen(struct socket * sock,int backlog)199 int inet_listen(struct socket *sock, int backlog)
200 {
201 	struct sock *sk = sock->sk;
202 	unsigned char old_state;
203 	int err, tcp_fastopen;
204 
205 	lock_sock(sk);
206 
207 	err = -EINVAL;
208 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
209 		goto out;
210 
211 	old_state = sk->sk_state;
212 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
213 		goto out;
214 
215 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
216 	/* Really, if the socket is already in listen state
217 	 * we can only allow the backlog to be adjusted.
218 	 */
219 	if (old_state != TCP_LISTEN) {
220 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
221 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
222 		 * Also fastopen backlog may already been set via the option
223 		 * because the socket was in TCP_LISTEN state previously but
224 		 * was shutdown() rather than close().
225 		 */
226 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
227 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
228 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
229 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
230 			fastopen_queue_tune(sk, backlog);
231 			tcp_fastopen_init_key_once(sock_net(sk));
232 		}
233 
234 		err = inet_csk_listen_start(sk, backlog);
235 		if (err)
236 			goto out;
237 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
238 	}
239 	err = 0;
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 
inet_create(struct net * net,struct socket * sock,int protocol,int kern)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 = -ENOBUFS;
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->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
338 
339 	inet->nodefrag = 0;
340 
341 	if (SOCK_RAW == sock->type) {
342 		inet->inet_num = protocol;
343 		if (IPPROTO_RAW == protocol)
344 			inet->hdrincl = 1;
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 	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 
360 	inet->uc_ttl	= -1;
361 	inet->mc_loop	= 1;
362 	inet->mc_ttl	= 1;
363 	inet->mc_all	= 1;
364 	inet->mc_index	= 0;
365 	inet->mc_list	= NULL;
366 	inet->rcv_tos	= 0;
367 
368 	sk_refcnt_debug_inc(sk);
369 
370 	if (inet->inet_num) {
371 		/* It assumes that any protocol which allows
372 		 * the user to assign a number at socket
373 		 * creation time automatically
374 		 * shares.
375 		 */
376 		inet->inet_sport = htons(inet->inet_num);
377 		/* Add to protocol hash chains. */
378 		err = sk->sk_prot->hash(sk);
379 		if (err) {
380 			sk_common_release(sk);
381 			goto out;
382 		}
383 	}
384 
385 	if (sk->sk_prot->init) {
386 		err = sk->sk_prot->init(sk);
387 		if (err) {
388 			sk_common_release(sk);
389 			goto out;
390 		}
391 	}
392 
393 	if (!kern) {
394 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
395 		if (err) {
396 			sk_common_release(sk);
397 			goto out;
398 		}
399 	}
400 out:
401 	return err;
402 out_rcu_unlock:
403 	rcu_read_unlock();
404 	goto out;
405 }
406 
407 
408 /*
409  *	The peer socket should always be NULL (or else). When we call this
410  *	function we are destroying the object and from then on nobody
411  *	should refer to it.
412  */
inet_release(struct socket * sock)413 int inet_release(struct socket *sock)
414 {
415 	struct sock *sk = sock->sk;
416 
417 	if (sk) {
418 		long timeout;
419 
420 		if (!sk->sk_kern_sock)
421 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
422 
423 		/* Applications forget to leave groups before exiting */
424 		ip_mc_drop_socket(sk);
425 
426 		/* If linger is set, we don't return until the close
427 		 * is complete.  Otherwise we return immediately. The
428 		 * actually closing is done the same either way.
429 		 *
430 		 * If the close is due to the process exiting, we never
431 		 * linger..
432 		 */
433 		timeout = 0;
434 		if (sock_flag(sk, SOCK_LINGER) &&
435 		    !(current->flags & PF_EXITING))
436 			timeout = sk->sk_lingertime;
437 		sk->sk_prot->close(sk, timeout);
438 		sock->sk = NULL;
439 	}
440 	return 0;
441 }
442 EXPORT_SYMBOL(inet_release);
443 
inet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)444 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
445 {
446 	struct sock *sk = sock->sk;
447 	int err;
448 
449 	/* If the socket has its own bind function then use it. (RAW) */
450 	if (sk->sk_prot->bind) {
451 		return sk->sk_prot->bind(sk, uaddr, addr_len);
452 	}
453 	if (addr_len < sizeof(struct sockaddr_in))
454 		return -EINVAL;
455 
456 	/* BPF prog is run before any checks are done so that if the prog
457 	 * changes context in a wrong way it will be caught.
458 	 */
459 	err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr);
460 	if (err)
461 		return err;
462 
463 	return __inet_bind(sk, uaddr, addr_len, BIND_WITH_LOCK);
464 }
465 EXPORT_SYMBOL(inet_bind);
466 
__inet_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len,u32 flags)467 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
468 		u32 flags)
469 {
470 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
471 	struct inet_sock *inet = inet_sk(sk);
472 	struct net *net = sock_net(sk);
473 	unsigned short snum;
474 	int chk_addr_ret;
475 	u32 tb_id = RT_TABLE_LOCAL;
476 	int err;
477 
478 	if (addr->sin_family != AF_INET) {
479 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
480 		 * only if s_addr is INADDR_ANY.
481 		 */
482 		err = -EAFNOSUPPORT;
483 		if (addr->sin_family != AF_UNSPEC ||
484 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
485 			goto out;
486 	}
487 
488 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
489 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
490 
491 	/* Not specified by any standard per-se, however it breaks too
492 	 * many applications when removed.  It is unfortunate since
493 	 * allowing applications to make a non-local bind solves
494 	 * several problems with systems using dynamic addressing.
495 	 * (ie. your servers still start up even if your ISDN link
496 	 *  is temporarily down)
497 	 */
498 	err = -EADDRNOTAVAIL;
499 	if (!inet_can_nonlocal_bind(net, inet) &&
500 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
501 	    chk_addr_ret != RTN_LOCAL &&
502 	    chk_addr_ret != RTN_MULTICAST &&
503 	    chk_addr_ret != RTN_BROADCAST)
504 		goto out;
505 
506 	snum = ntohs(addr->sin_port);
507 	err = -EACCES;
508 	if (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->bind_address_no_port ||
533 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
534 		if (sk->sk_prot->get_port(sk, snum)) {
535 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
536 			err = -EADDRINUSE;
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 				goto out_release_sock;
544 			}
545 		}
546 	}
547 
548 	if (inet->inet_rcv_saddr)
549 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
550 	if (snum)
551 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
552 	inet->inet_sport = htons(inet->inet_num);
553 	inet->inet_daddr = 0;
554 	inet->inet_dport = 0;
555 	sk_dst_reset(sk);
556 	err = 0;
557 out_release_sock:
558 	if (flags & BIND_WITH_LOCK)
559 		release_sock(sk);
560 out:
561 	return err;
562 }
563 
inet_dgram_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)564 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
565 		       int addr_len, int flags)
566 {
567 	struct sock *sk = sock->sk;
568 	const struct proto *prot;
569 	int err;
570 
571 	if (addr_len < sizeof(uaddr->sa_family))
572 		return -EINVAL;
573 
574 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
575 	prot = READ_ONCE(sk->sk_prot);
576 
577 	if (uaddr->sa_family == AF_UNSPEC)
578 		return prot->disconnect(sk, flags);
579 
580 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
581 		err = prot->pre_connect(sk, uaddr, addr_len);
582 		if (err)
583 			return err;
584 	}
585 
586 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
587 		return -EAGAIN;
588 	return prot->connect(sk, uaddr, addr_len);
589 }
590 EXPORT_SYMBOL(inet_dgram_connect);
591 
inet_wait_for_connect(struct sock * sk,long timeo,int writebias)592 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
593 {
594 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
595 
596 	add_wait_queue(sk_sleep(sk), &wait);
597 	sk->sk_write_pending += writebias;
598 	sk->sk_wait_pending++;
599 
600 	/* Basic assumption: if someone sets sk->sk_err, he _must_
601 	 * change state of the socket from TCP_SYN_*.
602 	 * Connect() does not allow to get error notifications
603 	 * without closing the socket.
604 	 */
605 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
606 		release_sock(sk);
607 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
608 		lock_sock(sk);
609 		if (signal_pending(current) || !timeo)
610 			break;
611 	}
612 	remove_wait_queue(sk_sleep(sk), &wait);
613 	sk->sk_write_pending -= writebias;
614 	sk->sk_wait_pending--;
615 	return timeo;
616 }
617 
618 /*
619  *	Connect to a remote host. There is regrettably still a little
620  *	TCP 'magic' in here.
621  */
__inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags,int is_sendmsg)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 			err = sk->sk_prot->disconnect(sk, flags);
644 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
645 			goto out;
646 		}
647 	}
648 
649 	switch (sock->state) {
650 	default:
651 		err = -EINVAL;
652 		goto out;
653 	case SS_CONNECTED:
654 		err = -EISCONN;
655 		goto out;
656 	case SS_CONNECTING:
657 		if (inet_sk(sk)->defer_connect)
658 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
659 		else
660 			err = -EALREADY;
661 		/* Fall out of switch with err, set for this state */
662 		break;
663 	case SS_UNCONNECTED:
664 		err = -EISCONN;
665 		if (sk->sk_state != TCP_CLOSE)
666 			goto out;
667 
668 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
669 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
670 			if (err)
671 				goto out;
672 		}
673 
674 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
675 		if (err < 0)
676 			goto out;
677 
678 		sock->state = SS_CONNECTING;
679 
680 		if (!err && inet_sk(sk)->defer_connect)
681 			goto out;
682 
683 		/* Just entered SS_CONNECTING state; the only
684 		 * difference is that return value in non-blocking
685 		 * case is EINPROGRESS, rather than EALREADY.
686 		 */
687 		err = -EINPROGRESS;
688 		break;
689 	}
690 
691 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
692 
693 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
694 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
695 				tcp_sk(sk)->fastopen_req &&
696 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
697 
698 		/* Error code is set above */
699 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
700 			goto out;
701 
702 		err = sock_intr_errno(timeo);
703 		if (signal_pending(current))
704 			goto out;
705 	}
706 
707 	/* Connection was closed by RST, timeout, ICMP error
708 	 * or another process disconnected us.
709 	 */
710 	if (sk->sk_state == TCP_CLOSE)
711 		goto sock_error;
712 
713 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
714 	 * and error was received after socket entered established state.
715 	 * Hence, it is handled normally after connect() return successfully.
716 	 */
717 
718 	sock->state = SS_CONNECTED;
719 	err = 0;
720 out:
721 	return err;
722 
723 sock_error:
724 	err = sock_error(sk) ? : -ECONNABORTED;
725 	sock->state = SS_UNCONNECTED;
726 	if (sk->sk_prot->disconnect(sk, flags))
727 		sock->state = SS_DISCONNECTING;
728 	goto out;
729 }
730 EXPORT_SYMBOL(__inet_stream_connect);
731 
inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)732 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
733 			int addr_len, int flags)
734 {
735 	int err;
736 
737 	lock_sock(sock->sk);
738 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
739 	release_sock(sock->sk);
740 	return err;
741 }
742 EXPORT_SYMBOL(inet_stream_connect);
743 
744 /*
745  *	Accept a pending connection. The TCP layer now gives BSD semantics.
746  */
747 
inet_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)748 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
749 		bool kern)
750 {
751 	struct sock *sk1 = sock->sk, *sk2;
752 	int err = -EINVAL;
753 
754 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
755 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
756 	if (!sk2)
757 		goto do_err;
758 
759 	lock_sock(sk2);
760 
761 	sock_rps_record_flow(sk2);
762 	WARN_ON(!((1 << sk2->sk_state) &
763 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
764 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
765 
766 	sock_graft(sk2, newsock);
767 
768 	newsock->state = SS_CONNECTED;
769 	err = 0;
770 	release_sock(sk2);
771 do_err:
772 	return err;
773 }
774 EXPORT_SYMBOL(inet_accept);
775 
776 /*
777  *	This does both peername and sockname.
778  */
inet_getname(struct socket * sock,struct sockaddr * uaddr,int peer)779 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
780 		 int peer)
781 {
782 	struct sock *sk		= sock->sk;
783 	struct inet_sock *inet	= inet_sk(sk);
784 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
785 
786 	sin->sin_family = AF_INET;
787 	if (peer) {
788 		if (!inet->inet_dport ||
789 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
790 		     peer == 1))
791 			return -ENOTCONN;
792 		sin->sin_port = inet->inet_dport;
793 		sin->sin_addr.s_addr = inet->inet_daddr;
794 	} else {
795 		__be32 addr = inet->inet_rcv_saddr;
796 		if (!addr)
797 			addr = inet->inet_saddr;
798 		sin->sin_port = inet->inet_sport;
799 		sin->sin_addr.s_addr = addr;
800 	}
801 	if (cgroup_bpf_enabled)
802 		BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin,
803 					    peer ? BPF_CGROUP_INET4_GETPEERNAME :
804 						   BPF_CGROUP_INET4_GETSOCKNAME,
805 					    NULL);
806 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
807 	return sizeof(*sin);
808 }
809 EXPORT_SYMBOL(inet_getname);
810 
inet_send_prepare(struct sock * sk)811 int inet_send_prepare(struct sock *sk)
812 {
813 	sock_rps_record_flow(sk);
814 
815 	/* We may need to bind the socket. */
816 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
817 	    inet_autobind(sk))
818 		return -EAGAIN;
819 
820 	return 0;
821 }
822 EXPORT_SYMBOL_GPL(inet_send_prepare);
823 
inet_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)824 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
825 {
826 	struct sock *sk = sock->sk;
827 
828 	if (unlikely(inet_send_prepare(sk)))
829 		return -EAGAIN;
830 
831 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
832 			       sk, msg, size);
833 }
834 EXPORT_SYMBOL(inet_sendmsg);
835 
inet_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)836 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
837 		      size_t size, int flags)
838 {
839 	struct sock *sk = sock->sk;
840 	const struct proto *prot;
841 
842 	if (unlikely(inet_send_prepare(sk)))
843 		return -EAGAIN;
844 
845 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
846 	prot = READ_ONCE(sk->sk_prot);
847 	if (prot->sendpage)
848 		return prot->sendpage(sk, page, offset, size, flags);
849 	return sock_no_sendpage(sock, page, offset, size, flags);
850 }
851 EXPORT_SYMBOL(inet_sendpage);
852 
853 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
854 					  size_t, int, int, int *));
inet_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)855 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
856 		 int flags)
857 {
858 	struct sock *sk = sock->sk;
859 	int addr_len = 0;
860 	int err;
861 
862 	if (likely(!(flags & MSG_ERRQUEUE)))
863 		sock_rps_record_flow(sk);
864 
865 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
866 			      sk, msg, size, flags & MSG_DONTWAIT,
867 			      flags & ~MSG_DONTWAIT, &addr_len);
868 	if (err >= 0)
869 		msg->msg_namelen = addr_len;
870 	return err;
871 }
872 EXPORT_SYMBOL(inet_recvmsg);
873 
inet_shutdown(struct socket * sock,int how)874 int inet_shutdown(struct socket *sock, int how)
875 {
876 	struct sock *sk = sock->sk;
877 	int err = 0;
878 
879 	/* This should really check to make sure
880 	 * the socket is a TCP socket. (WHY AC...)
881 	 */
882 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
883 		       1->2 bit 2 snds.
884 		       2->3 */
885 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
886 		return -EINVAL;
887 
888 	lock_sock(sk);
889 	if (sock->state == SS_CONNECTING) {
890 		if ((1 << sk->sk_state) &
891 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
892 			sock->state = SS_DISCONNECTING;
893 		else
894 			sock->state = SS_CONNECTED;
895 	}
896 
897 	switch (sk->sk_state) {
898 	case TCP_CLOSE:
899 		err = -ENOTCONN;
900 		/* Hack to wake up other listeners, who can poll for
901 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
902 		fallthrough;
903 	default:
904 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
905 		if (sk->sk_prot->shutdown)
906 			sk->sk_prot->shutdown(sk, how);
907 		break;
908 
909 	/* Remaining two branches are temporary solution for missing
910 	 * close() in multithreaded environment. It is _not_ a good idea,
911 	 * but we have no choice until close() is repaired at VFS level.
912 	 */
913 	case TCP_LISTEN:
914 		if (!(how & RCV_SHUTDOWN))
915 			break;
916 		fallthrough;
917 	case TCP_SYN_SENT:
918 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
919 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
920 		break;
921 	}
922 
923 	/* Wake up anyone sleeping in poll. */
924 	sk->sk_state_change(sk);
925 	release_sock(sk);
926 	return err;
927 }
928 EXPORT_SYMBOL(inet_shutdown);
929 
930 /*
931  *	ioctl() calls you can issue on an INET socket. Most of these are
932  *	device configuration and stuff and very rarely used. Some ioctls
933  *	pass on to the socket itself.
934  *
935  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
936  *	loads the devconfigure module does its configuring and unloads it.
937  *	There's a good 20K of config code hanging around the kernel.
938  */
939 
inet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)940 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
941 {
942 	struct sock *sk = sock->sk;
943 	int err = 0;
944 	struct net *net = sock_net(sk);
945 	void __user *p = (void __user *)arg;
946 	struct ifreq ifr;
947 	struct rtentry rt;
948 
949 	switch (cmd) {
950 	case SIOCADDRT:
951 	case SIOCDELRT:
952 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
953 			return -EFAULT;
954 		err = ip_rt_ioctl(net, cmd, &rt);
955 		break;
956 	case SIOCRTMSG:
957 		err = -EINVAL;
958 		break;
959 	case SIOCDARP:
960 	case SIOCGARP:
961 	case SIOCSARP:
962 		err = arp_ioctl(net, cmd, (void __user *)arg);
963 		break;
964 	case SIOCGIFADDR:
965 	case SIOCGIFBRDADDR:
966 	case SIOCGIFNETMASK:
967 	case SIOCGIFDSTADDR:
968 	case SIOCGIFPFLAGS:
969 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
970 			return -EFAULT;
971 		err = devinet_ioctl(net, cmd, &ifr);
972 		if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
973 			err = -EFAULT;
974 		break;
975 
976 	case SIOCSIFADDR:
977 	case SIOCSIFBRDADDR:
978 	case SIOCSIFNETMASK:
979 	case SIOCSIFDSTADDR:
980 	case SIOCSIFPFLAGS:
981 	case SIOCSIFFLAGS:
982 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
983 			return -EFAULT;
984 		err = devinet_ioctl(net, cmd, &ifr);
985 		break;
986 	default:
987 		if (sk->sk_prot->ioctl)
988 			err = sk->sk_prot->ioctl(sk, cmd, arg);
989 		else
990 			err = -ENOIOCTLCMD;
991 		break;
992 	}
993 	return err;
994 }
995 EXPORT_SYMBOL(inet_ioctl);
996 
997 #ifdef CONFIG_COMPAT
inet_compat_routing_ioctl(struct sock * sk,unsigned int cmd,struct compat_rtentry __user * ur)998 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
999 		struct compat_rtentry __user *ur)
1000 {
1001 	compat_uptr_t rtdev;
1002 	struct rtentry rt;
1003 
1004 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1005 			3 * sizeof(struct sockaddr)) ||
1006 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1007 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1008 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1009 	    get_user(rt.rt_window, &ur->rt_window) ||
1010 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1011 	    get_user(rtdev, &ur->rt_dev))
1012 		return -EFAULT;
1013 
1014 	rt.rt_dev = compat_ptr(rtdev);
1015 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1016 }
1017 
inet_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1018 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1019 {
1020 	void __user *argp = compat_ptr(arg);
1021 	struct sock *sk = sock->sk;
1022 
1023 	switch (cmd) {
1024 	case SIOCADDRT:
1025 	case SIOCDELRT:
1026 		return inet_compat_routing_ioctl(sk, cmd, argp);
1027 	default:
1028 		if (!sk->sk_prot->compat_ioctl)
1029 			return -ENOIOCTLCMD;
1030 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1031 	}
1032 }
1033 #endif /* CONFIG_COMPAT */
1034 
1035 const struct proto_ops inet_stream_ops = {
1036 	.family		   = PF_INET,
1037 	.owner		   = THIS_MODULE,
1038 	.release	   = inet_release,
1039 	.bind		   = inet_bind,
1040 	.connect	   = inet_stream_connect,
1041 	.socketpair	   = sock_no_socketpair,
1042 	.accept		   = inet_accept,
1043 	.getname	   = inet_getname,
1044 	.poll		   = tcp_poll,
1045 	.ioctl		   = inet_ioctl,
1046 	.gettstamp	   = sock_gettstamp,
1047 	.listen		   = inet_listen,
1048 	.shutdown	   = inet_shutdown,
1049 	.setsockopt	   = sock_common_setsockopt,
1050 	.getsockopt	   = sock_common_getsockopt,
1051 	.sendmsg	   = inet_sendmsg,
1052 	.recvmsg	   = inet_recvmsg,
1053 #ifdef CONFIG_MMU
1054 	.mmap		   = tcp_mmap,
1055 #endif
1056 	.sendpage	   = inet_sendpage,
1057 	.splice_read	   = tcp_splice_read,
1058 	.read_sock	   = tcp_read_sock,
1059 	.sendmsg_locked    = tcp_sendmsg_locked,
1060 	.sendpage_locked   = tcp_sendpage_locked,
1061 	.peek_len	   = tcp_peek_len,
1062 #ifdef CONFIG_COMPAT
1063 	.compat_ioctl	   = inet_compat_ioctl,
1064 #endif
1065 	.set_rcvlowat	   = tcp_set_rcvlowat,
1066 };
1067 EXPORT_SYMBOL(inet_stream_ops);
1068 
1069 const struct proto_ops inet_dgram_ops = {
1070 	.family		   = PF_INET,
1071 	.owner		   = THIS_MODULE,
1072 	.release	   = inet_release,
1073 	.bind		   = inet_bind,
1074 	.connect	   = inet_dgram_connect,
1075 	.socketpair	   = sock_no_socketpair,
1076 	.accept		   = sock_no_accept,
1077 	.getname	   = inet_getname,
1078 	.poll		   = udp_poll,
1079 	.ioctl		   = inet_ioctl,
1080 	.gettstamp	   = sock_gettstamp,
1081 	.listen		   = sock_no_listen,
1082 	.shutdown	   = inet_shutdown,
1083 	.setsockopt	   = sock_common_setsockopt,
1084 	.getsockopt	   = sock_common_getsockopt,
1085 	.sendmsg	   = inet_sendmsg,
1086 	.recvmsg	   = inet_recvmsg,
1087 	.mmap		   = sock_no_mmap,
1088 	.sendpage	   = inet_sendpage,
1089 	.set_peek_off	   = sk_set_peek_off,
1090 #ifdef CONFIG_COMPAT
1091 	.compat_ioctl	   = inet_compat_ioctl,
1092 #endif
1093 };
1094 EXPORT_SYMBOL(inet_dgram_ops);
1095 
1096 /*
1097  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1098  * udp_poll
1099  */
1100 static const struct proto_ops inet_sockraw_ops = {
1101 	.family		   = PF_INET,
1102 	.owner		   = THIS_MODULE,
1103 	.release	   = inet_release,
1104 	.bind		   = inet_bind,
1105 	.connect	   = inet_dgram_connect,
1106 	.socketpair	   = sock_no_socketpair,
1107 	.accept		   = sock_no_accept,
1108 	.getname	   = inet_getname,
1109 	.poll		   = datagram_poll,
1110 	.ioctl		   = inet_ioctl,
1111 	.gettstamp	   = sock_gettstamp,
1112 	.listen		   = sock_no_listen,
1113 	.shutdown	   = inet_shutdown,
1114 	.setsockopt	   = sock_common_setsockopt,
1115 	.getsockopt	   = sock_common_getsockopt,
1116 	.sendmsg	   = inet_sendmsg,
1117 	.recvmsg	   = inet_recvmsg,
1118 	.mmap		   = sock_no_mmap,
1119 	.sendpage	   = inet_sendpage,
1120 #ifdef CONFIG_COMPAT
1121 	.compat_ioctl	   = inet_compat_ioctl,
1122 #endif
1123 };
1124 
1125 static const struct net_proto_family inet_family_ops = {
1126 	.family = PF_INET,
1127 	.create = inet_create,
1128 	.owner	= THIS_MODULE,
1129 };
1130 
1131 /* Upon startup we insert all the elements in inetsw_array[] into
1132  * the linked list inetsw.
1133  */
1134 static struct inet_protosw inetsw_array[] =
1135 {
1136 	{
1137 		.type =       SOCK_STREAM,
1138 		.protocol =   IPPROTO_TCP,
1139 		.prot =       &tcp_prot,
1140 		.ops =        &inet_stream_ops,
1141 		.flags =      INET_PROTOSW_PERMANENT |
1142 			      INET_PROTOSW_ICSK,
1143 	},
1144 
1145 	{
1146 		.type =       SOCK_DGRAM,
1147 		.protocol =   IPPROTO_UDP,
1148 		.prot =       &udp_prot,
1149 		.ops =        &inet_dgram_ops,
1150 		.flags =      INET_PROTOSW_PERMANENT,
1151        },
1152 
1153        {
1154 		.type =       SOCK_DGRAM,
1155 		.protocol =   IPPROTO_ICMP,
1156 		.prot =       &ping_prot,
1157 		.ops =        &inet_sockraw_ops,
1158 		.flags =      INET_PROTOSW_REUSE,
1159        },
1160 
1161        {
1162 	       .type =       SOCK_RAW,
1163 	       .protocol =   IPPROTO_IP,	/* wild card */
1164 	       .prot =       &raw_prot,
1165 	       .ops =        &inet_sockraw_ops,
1166 	       .flags =      INET_PROTOSW_REUSE,
1167        }
1168 };
1169 
1170 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1171 
inet_register_protosw(struct inet_protosw * p)1172 void inet_register_protosw(struct inet_protosw *p)
1173 {
1174 	struct list_head *lh;
1175 	struct inet_protosw *answer;
1176 	int protocol = p->protocol;
1177 	struct list_head *last_perm;
1178 
1179 	spin_lock_bh(&inetsw_lock);
1180 
1181 	if (p->type >= SOCK_MAX)
1182 		goto out_illegal;
1183 
1184 	/* If we are trying to override a permanent protocol, bail. */
1185 	last_perm = &inetsw[p->type];
1186 	list_for_each(lh, &inetsw[p->type]) {
1187 		answer = list_entry(lh, struct inet_protosw, list);
1188 		/* Check only the non-wild match. */
1189 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1190 			break;
1191 		if (protocol == answer->protocol)
1192 			goto out_permanent;
1193 		last_perm = lh;
1194 	}
1195 
1196 	/* Add the new entry after the last permanent entry if any, so that
1197 	 * the new entry does not override a permanent entry when matched with
1198 	 * a wild-card protocol. But it is allowed to override any existing
1199 	 * non-permanent entry.  This means that when we remove this entry, the
1200 	 * system automatically returns to the old behavior.
1201 	 */
1202 	list_add_rcu(&p->list, last_perm);
1203 out:
1204 	spin_unlock_bh(&inetsw_lock);
1205 
1206 	return;
1207 
1208 out_permanent:
1209 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1210 	goto out;
1211 
1212 out_illegal:
1213 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1214 	       p->type);
1215 	goto out;
1216 }
1217 EXPORT_SYMBOL(inet_register_protosw);
1218 
inet_unregister_protosw(struct inet_protosw * p)1219 void inet_unregister_protosw(struct inet_protosw *p)
1220 {
1221 	if (INET_PROTOSW_PERMANENT & p->flags) {
1222 		pr_err("Attempt to unregister permanent protocol %d\n",
1223 		       p->protocol);
1224 	} else {
1225 		spin_lock_bh(&inetsw_lock);
1226 		list_del_rcu(&p->list);
1227 		spin_unlock_bh(&inetsw_lock);
1228 
1229 		synchronize_net();
1230 	}
1231 }
1232 EXPORT_SYMBOL(inet_unregister_protosw);
1233 
inet_sk_reselect_saddr(struct sock * sk)1234 static int inet_sk_reselect_saddr(struct sock *sk)
1235 {
1236 	struct inet_sock *inet = inet_sk(sk);
1237 	__be32 old_saddr = inet->inet_saddr;
1238 	__be32 daddr = inet->inet_daddr;
1239 	struct flowi4 *fl4;
1240 	struct rtable *rt;
1241 	__be32 new_saddr;
1242 	struct ip_options_rcu *inet_opt;
1243 
1244 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1245 					     lockdep_sock_is_held(sk));
1246 	if (inet_opt && inet_opt->opt.srr)
1247 		daddr = inet_opt->opt.faddr;
1248 
1249 	/* Query new route. */
1250 	fl4 = &inet->cork.fl.u.ip4;
1251 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1252 			      sk->sk_bound_dev_if, sk->sk_protocol,
1253 			      inet->inet_sport, inet->inet_dport, sk);
1254 	if (IS_ERR(rt))
1255 		return PTR_ERR(rt);
1256 
1257 	sk_setup_caps(sk, &rt->dst);
1258 
1259 	new_saddr = fl4->saddr;
1260 
1261 	if (new_saddr == old_saddr)
1262 		return 0;
1263 
1264 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1265 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1266 			__func__, &old_saddr, &new_saddr);
1267 	}
1268 
1269 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1270 
1271 	/*
1272 	 * XXX The only one ugly spot where we need to
1273 	 * XXX really change the sockets identity after
1274 	 * XXX it has entered the hashes. -DaveM
1275 	 *
1276 	 * Besides that, it does not check for connection
1277 	 * uniqueness. Wait for troubles.
1278 	 */
1279 	return __sk_prot_rehash(sk);
1280 }
1281 
inet_sk_rebuild_header(struct sock * sk)1282 int inet_sk_rebuild_header(struct sock *sk)
1283 {
1284 	struct inet_sock *inet = inet_sk(sk);
1285 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1286 	__be32 daddr;
1287 	struct ip_options_rcu *inet_opt;
1288 	struct flowi4 *fl4;
1289 	int err;
1290 
1291 	/* Route is OK, nothing to do. */
1292 	if (rt)
1293 		return 0;
1294 
1295 	/* Reroute. */
1296 	rcu_read_lock();
1297 	inet_opt = rcu_dereference(inet->inet_opt);
1298 	daddr = inet->inet_daddr;
1299 	if (inet_opt && inet_opt->opt.srr)
1300 		daddr = inet_opt->opt.faddr;
1301 	rcu_read_unlock();
1302 	fl4 = &inet->cork.fl.u.ip4;
1303 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1304 				   inet->inet_dport, inet->inet_sport,
1305 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1306 				   sk->sk_bound_dev_if);
1307 	if (!IS_ERR(rt)) {
1308 		err = 0;
1309 		sk_setup_caps(sk, &rt->dst);
1310 	} else {
1311 		err = PTR_ERR(rt);
1312 
1313 		/* Routing failed... */
1314 		sk->sk_route_caps = 0;
1315 		/*
1316 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1317 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1318 		 */
1319 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1320 		    sk->sk_state != TCP_SYN_SENT ||
1321 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1322 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1323 			sk->sk_err_soft = -err;
1324 	}
1325 
1326 	return err;
1327 }
1328 EXPORT_SYMBOL(inet_sk_rebuild_header);
1329 
inet_sk_set_state(struct sock * sk,int state)1330 void inet_sk_set_state(struct sock *sk, int state)
1331 {
1332 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1333 	sk->sk_state = state;
1334 }
1335 EXPORT_SYMBOL(inet_sk_set_state);
1336 
inet_sk_state_store(struct sock * sk,int newstate)1337 void inet_sk_state_store(struct sock *sk, int newstate)
1338 {
1339 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1340 	smp_store_release(&sk->sk_state, newstate);
1341 }
1342 
inet_gso_segment(struct sk_buff * skb,netdev_features_t features)1343 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1344 				 netdev_features_t features)
1345 {
1346 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1347 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1348 	const struct net_offload *ops;
1349 	unsigned int offset = 0;
1350 	struct iphdr *iph;
1351 	int proto, tot_len;
1352 	int nhoff;
1353 	int ihl;
1354 	int id;
1355 
1356 	skb_reset_network_header(skb);
1357 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1358 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1359 		goto out;
1360 
1361 	iph = ip_hdr(skb);
1362 	ihl = iph->ihl * 4;
1363 	if (ihl < sizeof(*iph))
1364 		goto out;
1365 
1366 	id = ntohs(iph->id);
1367 	proto = iph->protocol;
1368 
1369 	/* Warning: after this point, iph might be no longer valid */
1370 	if (unlikely(!pskb_may_pull(skb, ihl)))
1371 		goto out;
1372 	__skb_pull(skb, ihl);
1373 
1374 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1375 	if (encap)
1376 		features &= skb->dev->hw_enc_features;
1377 	SKB_GSO_CB(skb)->encap_level += ihl;
1378 
1379 	skb_reset_transport_header(skb);
1380 
1381 	segs = ERR_PTR(-EPROTONOSUPPORT);
1382 
1383 	if (!skb->encapsulation || encap) {
1384 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1385 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1386 
1387 		/* fixed ID is invalid if DF bit is not set */
1388 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1389 			goto out;
1390 	}
1391 
1392 	ops = rcu_dereference(inet_offloads[proto]);
1393 	if (likely(ops && ops->callbacks.gso_segment)) {
1394 		segs = ops->callbacks.gso_segment(skb, features);
1395 		if (!segs)
1396 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1397 	}
1398 
1399 	if (IS_ERR_OR_NULL(segs))
1400 		goto out;
1401 
1402 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1403 
1404 	skb = segs;
1405 	do {
1406 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1407 		if (udpfrag) {
1408 			iph->frag_off = htons(offset >> 3);
1409 			if (skb->next)
1410 				iph->frag_off |= htons(IP_MF);
1411 			offset += skb->len - nhoff - ihl;
1412 			tot_len = skb->len - nhoff;
1413 		} else if (skb_is_gso(skb)) {
1414 			if (!fixedid) {
1415 				iph->id = htons(id);
1416 				id += skb_shinfo(skb)->gso_segs;
1417 			}
1418 
1419 			if (gso_partial)
1420 				tot_len = skb_shinfo(skb)->gso_size +
1421 					  SKB_GSO_CB(skb)->data_offset +
1422 					  skb->head - (unsigned char *)iph;
1423 			else
1424 				tot_len = skb->len - nhoff;
1425 		} else {
1426 			if (!fixedid)
1427 				iph->id = htons(id++);
1428 			tot_len = skb->len - nhoff;
1429 		}
1430 		iph->tot_len = htons(tot_len);
1431 		ip_send_check(iph);
1432 		if (encap)
1433 			skb_reset_inner_headers(skb);
1434 		skb->network_header = (u8 *)iph - skb->head;
1435 		skb_reset_mac_len(skb);
1436 	} while ((skb = skb->next));
1437 
1438 out:
1439 	return segs;
1440 }
1441 EXPORT_SYMBOL(inet_gso_segment);
1442 
ipip_gso_segment(struct sk_buff * skb,netdev_features_t features)1443 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1444 					netdev_features_t features)
1445 {
1446 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1447 		return ERR_PTR(-EINVAL);
1448 
1449 	return inet_gso_segment(skb, features);
1450 }
1451 
inet_gro_receive(struct list_head * head,struct sk_buff * skb)1452 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1453 {
1454 	const struct net_offload *ops;
1455 	struct sk_buff *pp = NULL;
1456 	const struct iphdr *iph;
1457 	struct sk_buff *p;
1458 	unsigned int hlen;
1459 	unsigned int off;
1460 	unsigned int id;
1461 	int flush = 1;
1462 	int proto;
1463 
1464 	off = skb_gro_offset(skb);
1465 	hlen = off + sizeof(*iph);
1466 	iph = skb_gro_header_fast(skb, off);
1467 	if (skb_gro_header_hard(skb, hlen)) {
1468 		iph = skb_gro_header_slow(skb, hlen, off);
1469 		if (unlikely(!iph))
1470 			goto out;
1471 	}
1472 
1473 	proto = iph->protocol;
1474 
1475 	rcu_read_lock();
1476 	ops = rcu_dereference(inet_offloads[proto]);
1477 	if (!ops || !ops->callbacks.gro_receive)
1478 		goto out_unlock;
1479 
1480 	if (*(u8 *)iph != 0x45)
1481 		goto out_unlock;
1482 
1483 	if (ip_is_fragment(iph))
1484 		goto out_unlock;
1485 
1486 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1487 		goto out_unlock;
1488 
1489 	id = ntohl(*(__be32 *)&iph->id);
1490 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1491 	id >>= 16;
1492 
1493 	list_for_each_entry(p, head, list) {
1494 		struct iphdr *iph2;
1495 		u16 flush_id;
1496 
1497 		if (!NAPI_GRO_CB(p)->same_flow)
1498 			continue;
1499 
1500 		iph2 = (struct iphdr *)(p->data + off);
1501 		/* The above works because, with the exception of the top
1502 		 * (inner most) layer, we only aggregate pkts with the same
1503 		 * hdr length so all the hdrs we'll need to verify will start
1504 		 * at the same offset.
1505 		 */
1506 		if ((iph->protocol ^ iph2->protocol) |
1507 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1508 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1509 			NAPI_GRO_CB(p)->same_flow = 0;
1510 			continue;
1511 		}
1512 
1513 		/* All fields must match except length and checksum. */
1514 		NAPI_GRO_CB(p)->flush |=
1515 			(iph->ttl ^ iph2->ttl) |
1516 			(iph->tos ^ iph2->tos) |
1517 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1518 
1519 		NAPI_GRO_CB(p)->flush |= flush;
1520 
1521 		/* We need to store of the IP ID check to be included later
1522 		 * when we can verify that this packet does in fact belong
1523 		 * to a given flow.
1524 		 */
1525 		flush_id = (u16)(id - ntohs(iph2->id));
1526 
1527 		/* This bit of code makes it much easier for us to identify
1528 		 * the cases where we are doing atomic vs non-atomic IP ID
1529 		 * checks.  Specifically an atomic check can return IP ID
1530 		 * values 0 - 0xFFFF, while a non-atomic check can only
1531 		 * return 0 or 0xFFFF.
1532 		 */
1533 		if (!NAPI_GRO_CB(p)->is_atomic ||
1534 		    !(iph->frag_off & htons(IP_DF))) {
1535 			flush_id ^= NAPI_GRO_CB(p)->count;
1536 			flush_id = flush_id ? 0xFFFF : 0;
1537 		}
1538 
1539 		/* If the previous IP ID value was based on an atomic
1540 		 * datagram we can overwrite the value and ignore it.
1541 		 */
1542 		if (NAPI_GRO_CB(skb)->is_atomic)
1543 			NAPI_GRO_CB(p)->flush_id = flush_id;
1544 		else
1545 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1546 	}
1547 
1548 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1549 	NAPI_GRO_CB(skb)->flush |= flush;
1550 	skb_set_network_header(skb, off);
1551 	/* The above will be needed by the transport layer if there is one
1552 	 * immediately following this IP hdr.
1553 	 */
1554 
1555 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1556 	 * as we already checked checksum over ipv4 header was 0
1557 	 */
1558 	skb_gro_pull(skb, sizeof(*iph));
1559 	skb_set_transport_header(skb, skb_gro_offset(skb));
1560 
1561 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1562 				       ops->callbacks.gro_receive, head, skb);
1563 
1564 out_unlock:
1565 	rcu_read_unlock();
1566 
1567 out:
1568 	skb_gro_flush_final(skb, pp, flush);
1569 
1570 	return pp;
1571 }
1572 EXPORT_SYMBOL(inet_gro_receive);
1573 
ipip_gro_receive(struct list_head * head,struct sk_buff * skb)1574 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1575 					struct sk_buff *skb)
1576 {
1577 	if (NAPI_GRO_CB(skb)->encap_mark) {
1578 		NAPI_GRO_CB(skb)->flush = 1;
1579 		return NULL;
1580 	}
1581 
1582 	NAPI_GRO_CB(skb)->encap_mark = 1;
1583 
1584 	return inet_gro_receive(head, skb);
1585 }
1586 
1587 #define SECONDS_PER_DAY	86400
1588 
1589 /* inet_current_timestamp - Return IP network timestamp
1590  *
1591  * Return milliseconds since midnight in network byte order.
1592  */
inet_current_timestamp(void)1593 __be32 inet_current_timestamp(void)
1594 {
1595 	u32 secs;
1596 	u32 msecs;
1597 	struct timespec64 ts;
1598 
1599 	ktime_get_real_ts64(&ts);
1600 
1601 	/* Get secs since midnight. */
1602 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1603 	/* Convert to msecs. */
1604 	msecs = secs * MSEC_PER_SEC;
1605 	/* Convert nsec to msec. */
1606 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1607 
1608 	/* Convert to network byte order. */
1609 	return htonl(msecs);
1610 }
1611 EXPORT_SYMBOL(inet_current_timestamp);
1612 
inet_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)1613 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1614 {
1615 	if (sk->sk_family == AF_INET)
1616 		return ip_recv_error(sk, msg, len, addr_len);
1617 #if IS_ENABLED(CONFIG_IPV6)
1618 	if (sk->sk_family == AF_INET6)
1619 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1620 #endif
1621 	return -EINVAL;
1622 }
1623 
inet_gro_complete(struct sk_buff * skb,int nhoff)1624 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1625 {
1626 	__be16 newlen = htons(skb->len - nhoff);
1627 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1628 	const struct net_offload *ops;
1629 	int proto = iph->protocol;
1630 	int err = -ENOSYS;
1631 
1632 	if (skb->encapsulation) {
1633 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1634 		skb_set_inner_network_header(skb, nhoff);
1635 	}
1636 
1637 	csum_replace2(&iph->check, iph->tot_len, newlen);
1638 	iph->tot_len = newlen;
1639 
1640 	rcu_read_lock();
1641 	ops = rcu_dereference(inet_offloads[proto]);
1642 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1643 		goto out_unlock;
1644 
1645 	/* Only need to add sizeof(*iph) to get to the next hdr below
1646 	 * because any hdr with option will have been flushed in
1647 	 * inet_gro_receive().
1648 	 */
1649 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1650 			      tcp4_gro_complete, udp4_gro_complete,
1651 			      skb, nhoff + sizeof(*iph));
1652 
1653 out_unlock:
1654 	rcu_read_unlock();
1655 
1656 	return err;
1657 }
1658 EXPORT_SYMBOL(inet_gro_complete);
1659 
ipip_gro_complete(struct sk_buff * skb,int nhoff)1660 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1661 {
1662 	skb->encapsulation = 1;
1663 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1664 	return inet_gro_complete(skb, nhoff);
1665 }
1666 
inet_ctl_sock_create(struct sock ** sk,unsigned short family,unsigned short type,unsigned char protocol,struct net * net)1667 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1668 			 unsigned short type, unsigned char protocol,
1669 			 struct net *net)
1670 {
1671 	struct socket *sock;
1672 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1673 
1674 	if (rc == 0) {
1675 		*sk = sock->sk;
1676 		(*sk)->sk_allocation = GFP_ATOMIC;
1677 		/*
1678 		 * Unhash it so that IP input processing does not even see it,
1679 		 * we do not wish this socket to see incoming packets.
1680 		 */
1681 		(*sk)->sk_prot->unhash(*sk);
1682 	}
1683 	return rc;
1684 }
1685 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1686 
snmp_get_cpu_field(void __percpu * mib,int cpu,int offt)1687 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1688 {
1689 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1690 }
1691 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1692 
snmp_fold_field(void __percpu * mib,int offt)1693 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1694 {
1695 	unsigned long res = 0;
1696 	int i;
1697 
1698 	for_each_possible_cpu(i)
1699 		res += snmp_get_cpu_field(mib, i, offt);
1700 	return res;
1701 }
1702 EXPORT_SYMBOL_GPL(snmp_fold_field);
1703 
1704 #if BITS_PER_LONG==32
1705 
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offt,size_t syncp_offset)1706 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1707 			 size_t syncp_offset)
1708 {
1709 	void *bhptr;
1710 	struct u64_stats_sync *syncp;
1711 	u64 v;
1712 	unsigned int start;
1713 
1714 	bhptr = per_cpu_ptr(mib, cpu);
1715 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1716 	do {
1717 		start = u64_stats_fetch_begin_irq(syncp);
1718 		v = *(((u64 *)bhptr) + offt);
1719 	} while (u64_stats_fetch_retry_irq(syncp, start));
1720 
1721 	return v;
1722 }
1723 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1724 
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_offset)1725 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1726 {
1727 	u64 res = 0;
1728 	int cpu;
1729 
1730 	for_each_possible_cpu(cpu) {
1731 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1732 	}
1733 	return res;
1734 }
1735 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1736 #endif
1737 
1738 #ifdef CONFIG_IP_MULTICAST
1739 static const struct net_protocol igmp_protocol = {
1740 	.handler =	igmp_rcv,
1741 	.netns_ok =	1,
1742 };
1743 #endif
1744 
1745 static const struct net_protocol tcp_protocol = {
1746 	.handler	=	tcp_v4_rcv,
1747 	.err_handler	=	tcp_v4_err,
1748 	.no_policy	=	1,
1749 	.netns_ok	=	1,
1750 	.icmp_strict_tag_validation = 1,
1751 };
1752 
1753 static const struct net_protocol udp_protocol = {
1754 	.handler =	udp_rcv,
1755 	.err_handler =	udp_err,
1756 	.no_policy =	1,
1757 	.netns_ok =	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 	.netns_ok =	1,
1765 };
1766 
ipv4_mib_init_net(struct net * net)1767 static __net_init int ipv4_mib_init_net(struct net *net)
1768 {
1769 	int i;
1770 
1771 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1772 	if (!net->mib.tcp_statistics)
1773 		goto err_tcp_mib;
1774 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1775 	if (!net->mib.ip_statistics)
1776 		goto err_ip_mib;
1777 
1778 	for_each_possible_cpu(i) {
1779 		struct ipstats_mib *af_inet_stats;
1780 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1781 		u64_stats_init(&af_inet_stats->syncp);
1782 	}
1783 
1784 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1785 	if (!net->mib.net_statistics)
1786 		goto err_net_mib;
1787 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1788 	if (!net->mib.udp_statistics)
1789 		goto err_udp_mib;
1790 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1791 	if (!net->mib.udplite_statistics)
1792 		goto err_udplite_mib;
1793 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1794 	if (!net->mib.icmp_statistics)
1795 		goto err_icmp_mib;
1796 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1797 					      GFP_KERNEL);
1798 	if (!net->mib.icmpmsg_statistics)
1799 		goto err_icmpmsg_mib;
1800 
1801 	tcp_mib_init(net);
1802 	return 0;
1803 
1804 err_icmpmsg_mib:
1805 	free_percpu(net->mib.icmp_statistics);
1806 err_icmp_mib:
1807 	free_percpu(net->mib.udplite_statistics);
1808 err_udplite_mib:
1809 	free_percpu(net->mib.udp_statistics);
1810 err_udp_mib:
1811 	free_percpu(net->mib.net_statistics);
1812 err_net_mib:
1813 	free_percpu(net->mib.ip_statistics);
1814 err_ip_mib:
1815 	free_percpu(net->mib.tcp_statistics);
1816 err_tcp_mib:
1817 	return -ENOMEM;
1818 }
1819 
ipv4_mib_exit_net(struct net * net)1820 static __net_exit void ipv4_mib_exit_net(struct net *net)
1821 {
1822 	kfree(net->mib.icmpmsg_statistics);
1823 	free_percpu(net->mib.icmp_statistics);
1824 	free_percpu(net->mib.udplite_statistics);
1825 	free_percpu(net->mib.udp_statistics);
1826 	free_percpu(net->mib.net_statistics);
1827 	free_percpu(net->mib.ip_statistics);
1828 	free_percpu(net->mib.tcp_statistics);
1829 #ifdef CONFIG_MPTCP
1830 	/* allocated on demand, see mptcp_init_sock() */
1831 	free_percpu(net->mib.mptcp_statistics);
1832 #endif
1833 }
1834 
1835 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1836 	.init = ipv4_mib_init_net,
1837 	.exit = ipv4_mib_exit_net,
1838 };
1839 
init_ipv4_mibs(void)1840 static int __init init_ipv4_mibs(void)
1841 {
1842 	return register_pernet_subsys(&ipv4_mib_ops);
1843 }
1844 
inet_init_net(struct net * net)1845 static __net_init int inet_init_net(struct net *net)
1846 {
1847 	/*
1848 	 * Set defaults for local port range
1849 	 */
1850 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1851 	net->ipv4.ip_local_ports.range[0] =  32768;
1852 	net->ipv4.ip_local_ports.range[1] =  60999;
1853 
1854 	seqlock_init(&net->ipv4.ping_group_range.lock);
1855 	/*
1856 	 * Sane defaults - nobody may create ping sockets.
1857 	 * Boot scripts should set this to distro-specific group.
1858 	 */
1859 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1860 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1861 
1862 	/* Default values for sysctl-controlled parameters.
1863 	 * We set them here, in case sysctl is not compiled.
1864 	 */
1865 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1866 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1867 	net->ipv4.sysctl_ip_dynaddr = 0;
1868 	net->ipv4.sysctl_ip_early_demux = 1;
1869 	net->ipv4.sysctl_udp_early_demux = 1;
1870 	net->ipv4.sysctl_tcp_early_demux = 1;
1871 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1872 #ifdef CONFIG_SYSCTL
1873 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1874 #endif
1875 
1876 	/* Some igmp sysctl, whose values are always used */
1877 	net->ipv4.sysctl_igmp_max_memberships = 20;
1878 	net->ipv4.sysctl_igmp_max_msf = 10;
1879 	/* IGMP reports for link-local multicast groups are enabled by default */
1880 	net->ipv4.sysctl_igmp_llm_reports = 1;
1881 	net->ipv4.sysctl_igmp_qrv = 2;
1882 
1883 #ifdef CONFIG_LOWPOWER_PROTOCOL
1884 	lowpower_protocol_net_init(net);
1885 #endif /* CONFIG_LOWPOWER_PROTOCOL */
1886 	return 0;
1887 }
1888 
1889 static __net_initdata struct pernet_operations af_inet_ops = {
1890 	.init = inet_init_net,
1891 };
1892 
init_inet_pernet_ops(void)1893 static int __init init_inet_pernet_ops(void)
1894 {
1895 	return register_pernet_subsys(&af_inet_ops);
1896 }
1897 
1898 static int ipv4_proc_init(void);
1899 
1900 /*
1901  *	IP protocol layer initialiser
1902  */
1903 
1904 static struct packet_offload ip_packet_offload __read_mostly = {
1905 	.type = cpu_to_be16(ETH_P_IP),
1906 	.callbacks = {
1907 		.gso_segment = inet_gso_segment,
1908 		.gro_receive = inet_gro_receive,
1909 		.gro_complete = inet_gro_complete,
1910 	},
1911 };
1912 
1913 static const struct net_offload ipip_offload = {
1914 	.callbacks = {
1915 		.gso_segment	= ipip_gso_segment,
1916 		.gro_receive	= ipip_gro_receive,
1917 		.gro_complete	= ipip_gro_complete,
1918 	},
1919 };
1920 
ipip_offload_init(void)1921 static int __init ipip_offload_init(void)
1922 {
1923 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1924 }
1925 
ipv4_offload_init(void)1926 static int __init ipv4_offload_init(void)
1927 {
1928 	/*
1929 	 * Add offloads
1930 	 */
1931 	if (udpv4_offload_init() < 0)
1932 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1933 	if (tcpv4_offload_init() < 0)
1934 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1935 	if (ipip_offload_init() < 0)
1936 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1937 
1938 	dev_add_offload(&ip_packet_offload);
1939 	return 0;
1940 }
1941 
1942 fs_initcall(ipv4_offload_init);
1943 
1944 static struct packet_type ip_packet_type __read_mostly = {
1945 	.type = cpu_to_be16(ETH_P_IP),
1946 	.func = ip_rcv,
1947 	.list_func = ip_list_rcv,
1948 };
1949 
inet_init(void)1950 static int __init inet_init(void)
1951 {
1952 	struct inet_protosw *q;
1953 	struct list_head *r;
1954 	int rc;
1955 
1956 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
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
ipv4_proc_init(void)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 */
ipv4_proc_init(void)2108 static int __init ipv4_proc_init(void)
2109 {
2110 	return 0;
2111 }
2112 #endif /* CONFIG_PROC_FS */
2113