1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		PF_INET protocol family socket handler.
7  *
8  * Authors:	Ross Biro
9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *		Florian La Roche, <flla@stud.uni-sb.de>
11  *		Alan Cox, <A.Cox@swansea.ac.uk>
12  *
13  * Changes (see also sock.c)
14  *
15  *		piggy,
16  *		Karl Knutson	:	Socket protocol table
17  *		A.N.Kuznetsov	:	Socket death error in accept().
18  *		John Richardson :	Fix non blocking error in connect()
19  *					so sockets that fail to connect
20  *					don't return -EINPROGRESS.
21  *		Alan Cox	:	Asynchronous I/O support
22  *		Alan Cox	:	Keep correct socket pointer on sock
23  *					structures
24  *					when accept() ed
25  *		Alan Cox	:	Semantics of SO_LINGER aren't state
26  *					moved to close when you look carefully.
27  *					With this fixed and the accept bug fixed
28  *					some RPC stuff seems happier.
29  *		Niibe Yutaka	:	4.4BSD style write async I/O
30  *		Alan Cox,
31  *		Tony Gale 	:	Fixed reuse semantics.
32  *		Alan Cox	:	bind() shouldn't abort existing but dead
33  *					sockets. Stops FTP netin:.. I hope.
34  *		Alan Cox	:	bind() works correctly for RAW sockets.
35  *					Note that FreeBSD at least was broken
36  *					in this respect so be careful with
37  *					compatibility tests...
38  *		Alan Cox	:	routing cache support
39  *		Alan Cox	:	memzero the socket structure for
40  *					compactness.
41  *		Matt Day	:	nonblock connect error handler
42  *		Alan Cox	:	Allow large numbers of pending sockets
43  *					(eg for big web sites), but only if
44  *					specifically application requested.
45  *		Alan Cox	:	New buffering throughout IP. Used
46  *					dumbly.
47  *		Alan Cox	:	New buffering now used smartly.
48  *		Alan Cox	:	BSD rather than common sense
49  *					interpretation of listen.
50  *		Germano Caronni	:	Assorted small races.
51  *		Alan Cox	:	sendmsg/recvmsg basic support.
52  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
53  *		Alan Cox	:	Locked down bind (see security list).
54  *		Alan Cox	:	Loosened bind a little.
55  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
56  *	Willy Konynenberg	:	Transparent proxying support.
57  *		David S. Miller	:	New socket lookup architecture.
58  *					Some other random speedups.
59  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
60  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
61  *
62  *		This program is free software; you can redistribute it and/or
63  *		modify it under the terms of the GNU General Public License
64  *		as published by the Free Software Foundation; either version
65  *		2 of the License, or (at your option) any later version.
66  */
67 
68 #include <linux/err.h>
69 #include <linux/errno.h>
70 #include <linux/types.h>
71 #include <linux/socket.h>
72 #include <linux/in.h>
73 #include <linux/kernel.h>
74 #include <linux/module.h>
75 #include <linux/sched.h>
76 #include <linux/timer.h>
77 #include <linux/string.h>
78 #include <linux/sockios.h>
79 #include <linux/net.h>
80 #include <linux/capability.h>
81 #include <linux/fcntl.h>
82 #include <linux/mm.h>
83 #include <linux/interrupt.h>
84 #include <linux/stat.h>
85 #include <linux/init.h>
86 #include <linux/poll.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/slab.h>
90 
91 #include <asm/uaccess.h>
92 #include <asm/system.h>
93 
94 #include <linux/inet.h>
95 #include <linux/igmp.h>
96 #include <linux/inetdevice.h>
97 #include <linux/netdevice.h>
98 #include <net/checksum.h>
99 #include <net/ip.h>
100 #include <net/protocol.h>
101 #include <net/arp.h>
102 #include <net/route.h>
103 #include <net/ip_fib.h>
104 #include <net/inet_connection_sock.h>
105 #include <net/tcp.h>
106 #include <net/udp.h>
107 #include <net/udplite.h>
108 #include <linux/skbuff.h>
109 #include <net/sock.h>
110 #include <net/raw.h>
111 #include <net/icmp.h>
112 #include <net/ipip.h>
113 #include <net/inet_common.h>
114 #include <net/xfrm.h>
115 #include <net/net_namespace.h>
116 #ifdef CONFIG_IP_MROUTE
117 #include <linux/mroute.h>
118 #endif
119 
120 
121 /* The inetsw table contains everything that inet_create needs to
122  * build a new socket.
123  */
124 static struct list_head inetsw[SOCK_MAX];
125 static DEFINE_SPINLOCK(inetsw_lock);
126 
127 struct ipv4_config ipv4_config;
128 EXPORT_SYMBOL(ipv4_config);
129 
130 /* New destruction routine */
131 
inet_sock_destruct(struct sock * sk)132 void inet_sock_destruct(struct sock *sk)
133 {
134 	struct inet_sock *inet = inet_sk(sk);
135 
136 	__skb_queue_purge(&sk->sk_receive_queue);
137 	__skb_queue_purge(&sk->sk_error_queue);
138 
139 	sk_mem_reclaim(sk);
140 
141 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
142 		pr_err("Attempt to release TCP socket in state %d %p\n",
143 		       sk->sk_state, sk);
144 		return;
145 	}
146 	if (!sock_flag(sk, SOCK_DEAD)) {
147 		pr_err("Attempt to release alive inet socket %p\n", sk);
148 		return;
149 	}
150 
151 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
152 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
153 	WARN_ON(sk->sk_wmem_queued);
154 	WARN_ON(sk->sk_forward_alloc);
155 
156 	kfree(inet->opt);
157 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
158 	sk_refcnt_debug_dec(sk);
159 }
160 EXPORT_SYMBOL(inet_sock_destruct);
161 
162 /*
163  *	The routines beyond this point handle the behaviour of an AF_INET
164  *	socket object. Mostly it punts to the subprotocols of IP to do
165  *	the work.
166  */
167 
168 /*
169  *	Automatically bind an unbound socket.
170  */
171 
inet_autobind(struct sock * sk)172 static int inet_autobind(struct sock *sk)
173 {
174 	struct inet_sock *inet;
175 	/* We may need to bind the socket. */
176 	lock_sock(sk);
177 	inet = inet_sk(sk);
178 	if (!inet->inet_num) {
179 		if (sk->sk_prot->get_port(sk, 0)) {
180 			release_sock(sk);
181 			return -EAGAIN;
182 		}
183 		inet->inet_sport = htons(inet->inet_num);
184 	}
185 	release_sock(sk);
186 	return 0;
187 }
188 
189 /*
190  *	Move a socket into listening state.
191  */
inet_listen(struct socket * sock,int backlog)192 int inet_listen(struct socket *sock, int backlog)
193 {
194 	struct sock *sk = sock->sk;
195 	unsigned char old_state;
196 	int err;
197 
198 	lock_sock(sk);
199 
200 	err = -EINVAL;
201 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
202 		goto out;
203 
204 	old_state = sk->sk_state;
205 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
206 		goto out;
207 
208 	/* Really, if the socket is already in listen state
209 	 * we can only allow the backlog to be adjusted.
210 	 */
211 	if (old_state != TCP_LISTEN) {
212 		err = inet_csk_listen_start(sk, backlog);
213 		if (err)
214 			goto out;
215 	}
216 	sk->sk_max_ack_backlog = backlog;
217 	err = 0;
218 
219 out:
220 	release_sock(sk);
221 	return err;
222 }
223 EXPORT_SYMBOL(inet_listen);
224 
225 u32 inet_ehash_secret __read_mostly;
226 EXPORT_SYMBOL(inet_ehash_secret);
227 
228 /*
229  * inet_ehash_secret must be set exactly once
230  */
build_ehash_secret(void)231 void build_ehash_secret(void)
232 {
233 	u32 rnd;
234 
235 	do {
236 		get_random_bytes(&rnd, sizeof(rnd));
237 	} while (rnd == 0);
238 
239 	cmpxchg(&inet_ehash_secret, 0, rnd);
240 }
241 EXPORT_SYMBOL(build_ehash_secret);
242 
inet_netns_ok(struct net * net,int protocol)243 static inline int inet_netns_ok(struct net *net, int protocol)
244 {
245 	int hash;
246 	const struct net_protocol *ipprot;
247 
248 	if (net_eq(net, &init_net))
249 		return 1;
250 
251 	hash = protocol & (MAX_INET_PROTOS - 1);
252 	ipprot = rcu_dereference(inet_protos[hash]);
253 
254 	if (ipprot == NULL)
255 		/* raw IP is OK */
256 		return 1;
257 	return ipprot->netns_ok;
258 }
259 
260 /*
261  *	Create an inet socket.
262  */
263 
inet_create(struct net * net,struct socket * sock,int protocol,int kern)264 static int inet_create(struct net *net, struct socket *sock, int protocol,
265 		       int kern)
266 {
267 	struct sock *sk;
268 	struct inet_protosw *answer;
269 	struct inet_sock *inet;
270 	struct proto *answer_prot;
271 	unsigned char answer_flags;
272 	char answer_no_check;
273 	int try_loading_module = 0;
274 	int err;
275 
276 	if (unlikely(!inet_ehash_secret))
277 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
278 			build_ehash_secret();
279 
280 	sock->state = SS_UNCONNECTED;
281 
282 	/* Look for the requested type/protocol pair. */
283 lookup_protocol:
284 	err = -ESOCKTNOSUPPORT;
285 	rcu_read_lock();
286 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
287 
288 		err = 0;
289 		/* Check the non-wild match. */
290 		if (protocol == answer->protocol) {
291 			if (protocol != IPPROTO_IP)
292 				break;
293 		} else {
294 			/* Check for the two wild cases. */
295 			if (IPPROTO_IP == protocol) {
296 				protocol = answer->protocol;
297 				break;
298 			}
299 			if (IPPROTO_IP == answer->protocol)
300 				break;
301 		}
302 		err = -EPROTONOSUPPORT;
303 	}
304 
305 	if (unlikely(err)) {
306 		if (try_loading_module < 2) {
307 			rcu_read_unlock();
308 			/*
309 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
310 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
311 			 */
312 			if (++try_loading_module == 1)
313 				request_module("net-pf-%d-proto-%d-type-%d",
314 					       PF_INET, protocol, sock->type);
315 			/*
316 			 * Fall back to generic, e.g. net-pf-2-proto-132
317 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
318 			 */
319 			else
320 				request_module("net-pf-%d-proto-%d",
321 					       PF_INET, protocol);
322 			goto lookup_protocol;
323 		} else
324 			goto out_rcu_unlock;
325 	}
326 
327 	err = -EPERM;
328 	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
329 		goto out_rcu_unlock;
330 
331 	err = -EAFNOSUPPORT;
332 	if (!inet_netns_ok(net, protocol))
333 		goto out_rcu_unlock;
334 
335 	sock->ops = answer->ops;
336 	answer_prot = answer->prot;
337 	answer_no_check = answer->no_check;
338 	answer_flags = answer->flags;
339 	rcu_read_unlock();
340 
341 	WARN_ON(answer_prot->slab == NULL);
342 
343 	err = -ENOBUFS;
344 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
345 	if (sk == NULL)
346 		goto out;
347 
348 	err = 0;
349 	sk->sk_no_check = answer_no_check;
350 	if (INET_PROTOSW_REUSE & answer_flags)
351 		sk->sk_reuse = 1;
352 
353 	inet = inet_sk(sk);
354 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
355 
356 	inet->nodefrag = 0;
357 
358 	if (SOCK_RAW == sock->type) {
359 		inet->inet_num = protocol;
360 		if (IPPROTO_RAW == protocol)
361 			inet->hdrincl = 1;
362 	}
363 
364 	if (ipv4_config.no_pmtu_disc)
365 		inet->pmtudisc = IP_PMTUDISC_DONT;
366 	else
367 		inet->pmtudisc = IP_PMTUDISC_WANT;
368 
369 	inet->inet_id = 0;
370 
371 	sock_init_data(sock, sk);
372 
373 	sk->sk_destruct	   = inet_sock_destruct;
374 	sk->sk_protocol	   = protocol;
375 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
376 
377 	inet->uc_ttl	= -1;
378 	inet->mc_loop	= 1;
379 	inet->mc_ttl	= 1;
380 	inet->mc_all	= 1;
381 	inet->mc_index	= 0;
382 	inet->mc_list	= NULL;
383 
384 	sk_refcnt_debug_inc(sk);
385 
386 	if (inet->inet_num) {
387 		/* It assumes that any protocol which allows
388 		 * the user to assign a number at socket
389 		 * creation time automatically
390 		 * shares.
391 		 */
392 		inet->inet_sport = htons(inet->inet_num);
393 		/* Add to protocol hash chains. */
394 		sk->sk_prot->hash(sk);
395 	}
396 
397 	if (sk->sk_prot->init) {
398 		err = sk->sk_prot->init(sk);
399 		if (err)
400 			sk_common_release(sk);
401 	}
402 out:
403 	return err;
404 out_rcu_unlock:
405 	rcu_read_unlock();
406 	goto out;
407 }
408 
409 
410 /*
411  *	The peer socket should always be NULL (or else). When we call this
412  *	function we are destroying the object and from then on nobody
413  *	should refer to it.
414  */
inet_release(struct socket * sock)415 int inet_release(struct socket *sock)
416 {
417 	struct sock *sk = sock->sk;
418 
419 	if (sk) {
420 		long timeout;
421 
422 		sock_rps_reset_flow(sk);
423 
424 		/* Applications forget to leave groups before exiting */
425 		ip_mc_drop_socket(sk);
426 
427 		/* If linger is set, we don't return until the close
428 		 * is complete.  Otherwise we return immediately. The
429 		 * actually closing is done the same either way.
430 		 *
431 		 * If the close is due to the process exiting, we never
432 		 * linger..
433 		 */
434 		timeout = 0;
435 		if (sock_flag(sk, SOCK_LINGER) &&
436 		    !(current->flags & PF_EXITING))
437 			timeout = sk->sk_lingertime;
438 		sock->sk = NULL;
439 		sk->sk_prot->close(sk, timeout);
440 	}
441 	return 0;
442 }
443 EXPORT_SYMBOL(inet_release);
444 
445 /* It is off by default, see below. */
446 int sysctl_ip_nonlocal_bind __read_mostly;
447 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
448 
inet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)449 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
450 {
451 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
452 	struct sock *sk = sock->sk;
453 	struct inet_sock *inet = inet_sk(sk);
454 	unsigned short snum;
455 	int chk_addr_ret;
456 	int err;
457 
458 	/* If the socket has its own bind function then use it. (RAW) */
459 	if (sk->sk_prot->bind) {
460 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
461 		goto out;
462 	}
463 	err = -EINVAL;
464 	if (addr_len < sizeof(struct sockaddr_in))
465 		goto out;
466 
467 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
468 
469 	/* Not specified by any standard per-se, however it breaks too
470 	 * many applications when removed.  It is unfortunate since
471 	 * allowing applications to make a non-local bind solves
472 	 * several problems with systems using dynamic addressing.
473 	 * (ie. your servers still start up even if your ISDN link
474 	 *  is temporarily down)
475 	 */
476 	err = -EADDRNOTAVAIL;
477 	if (!sysctl_ip_nonlocal_bind &&
478 	    !(inet->freebind || inet->transparent) &&
479 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
480 	    chk_addr_ret != RTN_LOCAL &&
481 	    chk_addr_ret != RTN_MULTICAST &&
482 	    chk_addr_ret != RTN_BROADCAST)
483 		goto out;
484 
485 	snum = ntohs(addr->sin_port);
486 	err = -EACCES;
487 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
488 		goto out;
489 
490 	/*      We keep a pair of addresses. rcv_saddr is the one
491 	 *      used by hash lookups, and saddr is used for transmit.
492 	 *
493 	 *      In the BSD API these are the same except where it
494 	 *      would be illegal to use them (multicast/broadcast) in
495 	 *      which case the sending device address is used.
496 	 */
497 	lock_sock(sk);
498 
499 	/* Check these errors (active socket, double bind). */
500 	err = -EINVAL;
501 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
502 		goto out_release_sock;
503 
504 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
505 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
506 		inet->inet_saddr = 0;  /* Use device */
507 
508 	/* Make sure we are allowed to bind here. */
509 	if (sk->sk_prot->get_port(sk, snum)) {
510 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
511 		err = -EADDRINUSE;
512 		goto out_release_sock;
513 	}
514 
515 	if (inet->inet_rcv_saddr)
516 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
517 	if (snum)
518 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
519 	inet->inet_sport = htons(inet->inet_num);
520 	inet->inet_daddr = 0;
521 	inet->inet_dport = 0;
522 	sk_dst_reset(sk);
523 	err = 0;
524 out_release_sock:
525 	release_sock(sk);
526 out:
527 	return err;
528 }
529 EXPORT_SYMBOL(inet_bind);
530 
inet_dgram_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)531 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
532 		       int addr_len, int flags)
533 {
534 	struct sock *sk = sock->sk;
535 
536 	if (addr_len < sizeof(uaddr->sa_family))
537 		return -EINVAL;
538 	if (uaddr->sa_family == AF_UNSPEC)
539 		return sk->sk_prot->disconnect(sk, flags);
540 
541 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
542 		return -EAGAIN;
543 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
544 }
545 EXPORT_SYMBOL(inet_dgram_connect);
546 
inet_wait_for_connect(struct sock * sk,long timeo)547 static long inet_wait_for_connect(struct sock *sk, long timeo)
548 {
549 	DEFINE_WAIT(wait);
550 
551 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
552 
553 	/* Basic assumption: if someone sets sk->sk_err, he _must_
554 	 * change state of the socket from TCP_SYN_*.
555 	 * Connect() does not allow to get error notifications
556 	 * without closing the socket.
557 	 */
558 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
559 		release_sock(sk);
560 		timeo = schedule_timeout(timeo);
561 		lock_sock(sk);
562 		if (signal_pending(current) || !timeo)
563 			break;
564 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
565 	}
566 	finish_wait(sk_sleep(sk), &wait);
567 	return timeo;
568 }
569 
570 /*
571  *	Connect to a remote host. There is regrettably still a little
572  *	TCP 'magic' in here.
573  */
inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)574 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
575 			int addr_len, int flags)
576 {
577 	struct sock *sk = sock->sk;
578 	int err;
579 	long timeo;
580 
581 	if (addr_len < sizeof(uaddr->sa_family))
582 		return -EINVAL;
583 
584 	lock_sock(sk);
585 
586 	if (uaddr->sa_family == AF_UNSPEC) {
587 		err = sk->sk_prot->disconnect(sk, flags);
588 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
589 		goto out;
590 	}
591 
592 	switch (sock->state) {
593 	default:
594 		err = -EINVAL;
595 		goto out;
596 	case SS_CONNECTED:
597 		err = -EISCONN;
598 		goto out;
599 	case SS_CONNECTING:
600 		err = -EALREADY;
601 		/* Fall out of switch with err, set for this state */
602 		break;
603 	case SS_UNCONNECTED:
604 		err = -EISCONN;
605 		if (sk->sk_state != TCP_CLOSE)
606 			goto out;
607 
608 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
609 		if (err < 0)
610 			goto out;
611 
612 		sock->state = SS_CONNECTING;
613 
614 		/* Just entered SS_CONNECTING state; the only
615 		 * difference is that return value in non-blocking
616 		 * case is EINPROGRESS, rather than EALREADY.
617 		 */
618 		err = -EINPROGRESS;
619 		break;
620 	}
621 
622 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
623 
624 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
625 		/* Error code is set above */
626 		if (!timeo || !inet_wait_for_connect(sk, timeo))
627 			goto out;
628 
629 		err = sock_intr_errno(timeo);
630 		if (signal_pending(current))
631 			goto out;
632 	}
633 
634 	/* Connection was closed by RST, timeout, ICMP error
635 	 * or another process disconnected us.
636 	 */
637 	if (sk->sk_state == TCP_CLOSE)
638 		goto sock_error;
639 
640 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
641 	 * and error was received after socket entered established state.
642 	 * Hence, it is handled normally after connect() return successfully.
643 	 */
644 
645 	sock->state = SS_CONNECTED;
646 	err = 0;
647 out:
648 	release_sock(sk);
649 	return err;
650 
651 sock_error:
652 	err = sock_error(sk) ? : -ECONNABORTED;
653 	sock->state = SS_UNCONNECTED;
654 	if (sk->sk_prot->disconnect(sk, flags))
655 		sock->state = SS_DISCONNECTING;
656 	goto out;
657 }
658 EXPORT_SYMBOL(inet_stream_connect);
659 
660 /*
661  *	Accept a pending connection. The TCP layer now gives BSD semantics.
662  */
663 
inet_accept(struct socket * sock,struct socket * newsock,int flags)664 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
665 {
666 	struct sock *sk1 = sock->sk;
667 	int err = -EINVAL;
668 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
669 
670 	if (!sk2)
671 		goto do_err;
672 
673 	lock_sock(sk2);
674 
675 	WARN_ON(!((1 << sk2->sk_state) &
676 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
677 
678 	sock_graft(sk2, newsock);
679 
680 	newsock->state = SS_CONNECTED;
681 	err = 0;
682 	release_sock(sk2);
683 do_err:
684 	return err;
685 }
686 EXPORT_SYMBOL(inet_accept);
687 
688 
689 /*
690  *	This does both peername and sockname.
691  */
inet_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)692 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
693 			int *uaddr_len, int peer)
694 {
695 	struct sock *sk		= sock->sk;
696 	struct inet_sock *inet	= inet_sk(sk);
697 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
698 
699 	sin->sin_family = AF_INET;
700 	if (peer) {
701 		if (!inet->inet_dport ||
702 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
703 		     peer == 1))
704 			return -ENOTCONN;
705 		sin->sin_port = inet->inet_dport;
706 		sin->sin_addr.s_addr = inet->inet_daddr;
707 	} else {
708 		__be32 addr = inet->inet_rcv_saddr;
709 		if (!addr)
710 			addr = inet->inet_saddr;
711 		sin->sin_port = inet->inet_sport;
712 		sin->sin_addr.s_addr = addr;
713 	}
714 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
715 	*uaddr_len = sizeof(*sin);
716 	return 0;
717 }
718 EXPORT_SYMBOL(inet_getname);
719 
inet_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size)720 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
721 		 size_t size)
722 {
723 	struct sock *sk = sock->sk;
724 
725 	sock_rps_record_flow(sk);
726 
727 	/* We may need to bind the socket. */
728 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
729 	    inet_autobind(sk))
730 		return -EAGAIN;
731 
732 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
733 }
734 EXPORT_SYMBOL(inet_sendmsg);
735 
inet_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)736 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
737 		      size_t size, int flags)
738 {
739 	struct sock *sk = sock->sk;
740 
741 	sock_rps_record_flow(sk);
742 
743 	/* We may need to bind the socket. */
744 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
745 	    inet_autobind(sk))
746 		return -EAGAIN;
747 
748 	if (sk->sk_prot->sendpage)
749 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
750 	return sock_no_sendpage(sock, page, offset, size, flags);
751 }
752 EXPORT_SYMBOL(inet_sendpage);
753 
inet_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size,int flags)754 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
755 		 size_t size, int flags)
756 {
757 	struct sock *sk = sock->sk;
758 	int addr_len = 0;
759 	int err;
760 
761 	sock_rps_record_flow(sk);
762 
763 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
764 				   flags & ~MSG_DONTWAIT, &addr_len);
765 	if (err >= 0)
766 		msg->msg_namelen = addr_len;
767 	return err;
768 }
769 EXPORT_SYMBOL(inet_recvmsg);
770 
inet_shutdown(struct socket * sock,int how)771 int inet_shutdown(struct socket *sock, int how)
772 {
773 	struct sock *sk = sock->sk;
774 	int err = 0;
775 
776 	/* This should really check to make sure
777 	 * the socket is a TCP socket. (WHY AC...)
778 	 */
779 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
780 		       1->2 bit 2 snds.
781 		       2->3 */
782 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
783 		return -EINVAL;
784 
785 	lock_sock(sk);
786 	if (sock->state == SS_CONNECTING) {
787 		if ((1 << sk->sk_state) &
788 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
789 			sock->state = SS_DISCONNECTING;
790 		else
791 			sock->state = SS_CONNECTED;
792 	}
793 
794 	switch (sk->sk_state) {
795 	case TCP_CLOSE:
796 		err = -ENOTCONN;
797 		/* Hack to wake up other listeners, who can poll for
798 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
799 	default:
800 		sk->sk_shutdown |= how;
801 		if (sk->sk_prot->shutdown)
802 			sk->sk_prot->shutdown(sk, how);
803 		break;
804 
805 	/* Remaining two branches are temporary solution for missing
806 	 * close() in multithreaded environment. It is _not_ a good idea,
807 	 * but we have no choice until close() is repaired at VFS level.
808 	 */
809 	case TCP_LISTEN:
810 		if (!(how & RCV_SHUTDOWN))
811 			break;
812 		/* Fall through */
813 	case TCP_SYN_SENT:
814 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
815 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
816 		break;
817 	}
818 
819 	/* Wake up anyone sleeping in poll. */
820 	sk->sk_state_change(sk);
821 	release_sock(sk);
822 	return err;
823 }
824 EXPORT_SYMBOL(inet_shutdown);
825 
826 /*
827  *	ioctl() calls you can issue on an INET socket. Most of these are
828  *	device configuration and stuff and very rarely used. Some ioctls
829  *	pass on to the socket itself.
830  *
831  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
832  *	loads the devconfigure module does its configuring and unloads it.
833  *	There's a good 20K of config code hanging around the kernel.
834  */
835 
inet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)836 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
837 {
838 	struct sock *sk = sock->sk;
839 	int err = 0;
840 	struct net *net = sock_net(sk);
841 
842 	switch (cmd) {
843 	case SIOCGSTAMP:
844 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
845 		break;
846 	case SIOCGSTAMPNS:
847 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
848 		break;
849 	case SIOCADDRT:
850 	case SIOCDELRT:
851 	case SIOCRTMSG:
852 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
853 		break;
854 	case SIOCDARP:
855 	case SIOCGARP:
856 	case SIOCSARP:
857 		err = arp_ioctl(net, cmd, (void __user *)arg);
858 		break;
859 	case SIOCGIFADDR:
860 	case SIOCSIFADDR:
861 	case SIOCGIFBRDADDR:
862 	case SIOCSIFBRDADDR:
863 	case SIOCGIFNETMASK:
864 	case SIOCSIFNETMASK:
865 	case SIOCGIFDSTADDR:
866 	case SIOCSIFDSTADDR:
867 	case SIOCSIFPFLAGS:
868 	case SIOCGIFPFLAGS:
869 	case SIOCSIFFLAGS:
870 		err = devinet_ioctl(net, cmd, (void __user *)arg);
871 		break;
872 	default:
873 		if (sk->sk_prot->ioctl)
874 			err = sk->sk_prot->ioctl(sk, cmd, arg);
875 		else
876 			err = -ENOIOCTLCMD;
877 		break;
878 	}
879 	return err;
880 }
881 EXPORT_SYMBOL(inet_ioctl);
882 
883 #ifdef CONFIG_COMPAT
inet_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)884 int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
885 {
886 	struct sock *sk = sock->sk;
887 	int err = -ENOIOCTLCMD;
888 
889 	if (sk->sk_prot->compat_ioctl)
890 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
891 
892 	return err;
893 }
894 #endif
895 
896 const struct proto_ops inet_stream_ops = {
897 	.family		   = PF_INET,
898 	.owner		   = THIS_MODULE,
899 	.release	   = inet_release,
900 	.bind		   = inet_bind,
901 	.connect	   = inet_stream_connect,
902 	.socketpair	   = sock_no_socketpair,
903 	.accept		   = inet_accept,
904 	.getname	   = inet_getname,
905 	.poll		   = tcp_poll,
906 	.ioctl		   = inet_ioctl,
907 	.listen		   = inet_listen,
908 	.shutdown	   = inet_shutdown,
909 	.setsockopt	   = sock_common_setsockopt,
910 	.getsockopt	   = sock_common_getsockopt,
911 	.sendmsg	   = inet_sendmsg,
912 	.recvmsg	   = inet_recvmsg,
913 	.mmap		   = sock_no_mmap,
914 	.sendpage	   = inet_sendpage,
915 	.splice_read	   = tcp_splice_read,
916 #ifdef CONFIG_COMPAT
917 	.compat_setsockopt = compat_sock_common_setsockopt,
918 	.compat_getsockopt = compat_sock_common_getsockopt,
919 	.compat_ioctl	   = inet_compat_ioctl,
920 #endif
921 };
922 EXPORT_SYMBOL(inet_stream_ops);
923 
924 const struct proto_ops inet_dgram_ops = {
925 	.family		   = PF_INET,
926 	.owner		   = THIS_MODULE,
927 	.release	   = inet_release,
928 	.bind		   = inet_bind,
929 	.connect	   = inet_dgram_connect,
930 	.socketpair	   = sock_no_socketpair,
931 	.accept		   = sock_no_accept,
932 	.getname	   = inet_getname,
933 	.poll		   = udp_poll,
934 	.ioctl		   = inet_ioctl,
935 	.listen		   = sock_no_listen,
936 	.shutdown	   = inet_shutdown,
937 	.setsockopt	   = sock_common_setsockopt,
938 	.getsockopt	   = sock_common_getsockopt,
939 	.sendmsg	   = inet_sendmsg,
940 	.recvmsg	   = inet_recvmsg,
941 	.mmap		   = sock_no_mmap,
942 	.sendpage	   = inet_sendpage,
943 #ifdef CONFIG_COMPAT
944 	.compat_setsockopt = compat_sock_common_setsockopt,
945 	.compat_getsockopt = compat_sock_common_getsockopt,
946 	.compat_ioctl	   = inet_compat_ioctl,
947 #endif
948 };
949 EXPORT_SYMBOL(inet_dgram_ops);
950 
951 /*
952  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
953  * udp_poll
954  */
955 static const struct proto_ops inet_sockraw_ops = {
956 	.family		   = PF_INET,
957 	.owner		   = THIS_MODULE,
958 	.release	   = inet_release,
959 	.bind		   = inet_bind,
960 	.connect	   = inet_dgram_connect,
961 	.socketpair	   = sock_no_socketpair,
962 	.accept		   = sock_no_accept,
963 	.getname	   = inet_getname,
964 	.poll		   = datagram_poll,
965 	.ioctl		   = inet_ioctl,
966 	.listen		   = sock_no_listen,
967 	.shutdown	   = inet_shutdown,
968 	.setsockopt	   = sock_common_setsockopt,
969 	.getsockopt	   = sock_common_getsockopt,
970 	.sendmsg	   = inet_sendmsg,
971 	.recvmsg	   = inet_recvmsg,
972 	.mmap		   = sock_no_mmap,
973 	.sendpage	   = inet_sendpage,
974 #ifdef CONFIG_COMPAT
975 	.compat_setsockopt = compat_sock_common_setsockopt,
976 	.compat_getsockopt = compat_sock_common_getsockopt,
977 	.compat_ioctl	   = inet_compat_ioctl,
978 #endif
979 };
980 
981 static const struct net_proto_family inet_family_ops = {
982 	.family = PF_INET,
983 	.create = inet_create,
984 	.owner	= THIS_MODULE,
985 };
986 
987 /* Upon startup we insert all the elements in inetsw_array[] into
988  * the linked list inetsw.
989  */
990 static struct inet_protosw inetsw_array[] =
991 {
992 	{
993 		.type =       SOCK_STREAM,
994 		.protocol =   IPPROTO_TCP,
995 		.prot =       &tcp_prot,
996 		.ops =        &inet_stream_ops,
997 		.no_check =   0,
998 		.flags =      INET_PROTOSW_PERMANENT |
999 			      INET_PROTOSW_ICSK,
1000 	},
1001 
1002 	{
1003 		.type =       SOCK_DGRAM,
1004 		.protocol =   IPPROTO_UDP,
1005 		.prot =       &udp_prot,
1006 		.ops =        &inet_dgram_ops,
1007 		.no_check =   UDP_CSUM_DEFAULT,
1008 		.flags =      INET_PROTOSW_PERMANENT,
1009        },
1010 
1011 
1012        {
1013 	       .type =       SOCK_RAW,
1014 	       .protocol =   IPPROTO_IP,	/* wild card */
1015 	       .prot =       &raw_prot,
1016 	       .ops =        &inet_sockraw_ops,
1017 	       .no_check =   UDP_CSUM_DEFAULT,
1018 	       .flags =      INET_PROTOSW_REUSE,
1019        }
1020 };
1021 
1022 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1023 
inet_register_protosw(struct inet_protosw * p)1024 void inet_register_protosw(struct inet_protosw *p)
1025 {
1026 	struct list_head *lh;
1027 	struct inet_protosw *answer;
1028 	int protocol = p->protocol;
1029 	struct list_head *last_perm;
1030 
1031 	spin_lock_bh(&inetsw_lock);
1032 
1033 	if (p->type >= SOCK_MAX)
1034 		goto out_illegal;
1035 
1036 	/* If we are trying to override a permanent protocol, bail. */
1037 	answer = NULL;
1038 	last_perm = &inetsw[p->type];
1039 	list_for_each(lh, &inetsw[p->type]) {
1040 		answer = list_entry(lh, struct inet_protosw, list);
1041 
1042 		/* Check only the non-wild match. */
1043 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1044 			if (protocol == answer->protocol)
1045 				break;
1046 			last_perm = lh;
1047 		}
1048 
1049 		answer = NULL;
1050 	}
1051 	if (answer)
1052 		goto out_permanent;
1053 
1054 	/* Add the new entry after the last permanent entry if any, so that
1055 	 * the new entry does not override a permanent entry when matched with
1056 	 * a wild-card protocol. But it is allowed to override any existing
1057 	 * non-permanent entry.  This means that when we remove this entry, the
1058 	 * system automatically returns to the old behavior.
1059 	 */
1060 	list_add_rcu(&p->list, last_perm);
1061 out:
1062 	spin_unlock_bh(&inetsw_lock);
1063 
1064 	return;
1065 
1066 out_permanent:
1067 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1068 	       protocol);
1069 	goto out;
1070 
1071 out_illegal:
1072 	printk(KERN_ERR
1073 	       "Ignoring attempt to register invalid socket type %d.\n",
1074 	       p->type);
1075 	goto out;
1076 }
1077 EXPORT_SYMBOL(inet_register_protosw);
1078 
inet_unregister_protosw(struct inet_protosw * p)1079 void inet_unregister_protosw(struct inet_protosw *p)
1080 {
1081 	if (INET_PROTOSW_PERMANENT & p->flags) {
1082 		printk(KERN_ERR
1083 		       "Attempt to unregister permanent protocol %d.\n",
1084 		       p->protocol);
1085 	} else {
1086 		spin_lock_bh(&inetsw_lock);
1087 		list_del_rcu(&p->list);
1088 		spin_unlock_bh(&inetsw_lock);
1089 
1090 		synchronize_net();
1091 	}
1092 }
1093 EXPORT_SYMBOL(inet_unregister_protosw);
1094 
1095 /*
1096  *      Shall we try to damage output packets if routing dev changes?
1097  */
1098 
1099 int sysctl_ip_dynaddr __read_mostly;
1100 
inet_sk_reselect_saddr(struct sock * sk)1101 static int inet_sk_reselect_saddr(struct sock *sk)
1102 {
1103 	struct inet_sock *inet = inet_sk(sk);
1104 	__be32 old_saddr = inet->inet_saddr;
1105 	__be32 daddr = inet->inet_daddr;
1106 	struct rtable *rt;
1107 	__be32 new_saddr;
1108 
1109 	if (inet->opt && inet->opt->srr)
1110 		daddr = inet->opt->faddr;
1111 
1112 	/* Query new route. */
1113 	rt = ip_route_connect(daddr, 0, RT_CONN_FLAGS(sk),
1114 			      sk->sk_bound_dev_if, sk->sk_protocol,
1115 			      inet->inet_sport, inet->inet_dport, sk, false);
1116 	if (IS_ERR(rt))
1117 		return PTR_ERR(rt);
1118 
1119 	sk_setup_caps(sk, &rt->dst);
1120 
1121 	new_saddr = rt->rt_src;
1122 
1123 	if (new_saddr == old_saddr)
1124 		return 0;
1125 
1126 	if (sysctl_ip_dynaddr > 1) {
1127 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1128 		       __func__, &old_saddr, &new_saddr);
1129 	}
1130 
1131 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1132 
1133 	/*
1134 	 * XXX The only one ugly spot where we need to
1135 	 * XXX really change the sockets identity after
1136 	 * XXX it has entered the hashes. -DaveM
1137 	 *
1138 	 * Besides that, it does not check for connection
1139 	 * uniqueness. Wait for troubles.
1140 	 */
1141 	__sk_prot_rehash(sk);
1142 	return 0;
1143 }
1144 
inet_sk_rebuild_header(struct sock * sk)1145 int inet_sk_rebuild_header(struct sock *sk)
1146 {
1147 	struct inet_sock *inet = inet_sk(sk);
1148 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1149 	__be32 daddr;
1150 	int err;
1151 
1152 	/* Route is OK, nothing to do. */
1153 	if (rt)
1154 		return 0;
1155 
1156 	/* Reroute. */
1157 	daddr = inet->inet_daddr;
1158 	if (inet->opt && inet->opt->srr)
1159 		daddr = inet->opt->faddr;
1160 	rt = ip_route_output_ports(sock_net(sk), sk, daddr, inet->inet_saddr,
1161 				   inet->inet_dport, inet->inet_sport,
1162 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1163 				   sk->sk_bound_dev_if);
1164 	if (!IS_ERR(rt)) {
1165 		err = 0;
1166 		sk_setup_caps(sk, &rt->dst);
1167 	} else {
1168 		err = PTR_ERR(rt);
1169 
1170 		/* Routing failed... */
1171 		sk->sk_route_caps = 0;
1172 		/*
1173 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1174 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1175 		 */
1176 		if (!sysctl_ip_dynaddr ||
1177 		    sk->sk_state != TCP_SYN_SENT ||
1178 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1179 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1180 			sk->sk_err_soft = -err;
1181 	}
1182 
1183 	return err;
1184 }
1185 EXPORT_SYMBOL(inet_sk_rebuild_header);
1186 
inet_gso_send_check(struct sk_buff * skb)1187 static int inet_gso_send_check(struct sk_buff *skb)
1188 {
1189 	struct iphdr *iph;
1190 	const struct net_protocol *ops;
1191 	int proto;
1192 	int ihl;
1193 	int err = -EINVAL;
1194 
1195 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1196 		goto out;
1197 
1198 	iph = ip_hdr(skb);
1199 	ihl = iph->ihl * 4;
1200 	if (ihl < sizeof(*iph))
1201 		goto out;
1202 
1203 	if (unlikely(!pskb_may_pull(skb, ihl)))
1204 		goto out;
1205 
1206 	__skb_pull(skb, ihl);
1207 	skb_reset_transport_header(skb);
1208 	iph = ip_hdr(skb);
1209 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1210 	err = -EPROTONOSUPPORT;
1211 
1212 	rcu_read_lock();
1213 	ops = rcu_dereference(inet_protos[proto]);
1214 	if (likely(ops && ops->gso_send_check))
1215 		err = ops->gso_send_check(skb);
1216 	rcu_read_unlock();
1217 
1218 out:
1219 	return err;
1220 }
1221 
inet_gso_segment(struct sk_buff * skb,u32 features)1222 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, u32 features)
1223 {
1224 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1225 	struct iphdr *iph;
1226 	const struct net_protocol *ops;
1227 	int proto;
1228 	int ihl;
1229 	int id;
1230 	unsigned int offset = 0;
1231 
1232 	if (!(features & NETIF_F_V4_CSUM))
1233 		features &= ~NETIF_F_SG;
1234 
1235 	if (unlikely(skb_shinfo(skb)->gso_type &
1236 		     ~(SKB_GSO_TCPV4 |
1237 		       SKB_GSO_UDP |
1238 		       SKB_GSO_DODGY |
1239 		       SKB_GSO_TCP_ECN |
1240 		       0)))
1241 		goto out;
1242 
1243 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1244 		goto out;
1245 
1246 	iph = ip_hdr(skb);
1247 	ihl = iph->ihl * 4;
1248 	if (ihl < sizeof(*iph))
1249 		goto out;
1250 
1251 	if (unlikely(!pskb_may_pull(skb, ihl)))
1252 		goto out;
1253 
1254 	__skb_pull(skb, ihl);
1255 	skb_reset_transport_header(skb);
1256 	iph = ip_hdr(skb);
1257 	id = ntohs(iph->id);
1258 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1259 	segs = ERR_PTR(-EPROTONOSUPPORT);
1260 
1261 	rcu_read_lock();
1262 	ops = rcu_dereference(inet_protos[proto]);
1263 	if (likely(ops && ops->gso_segment))
1264 		segs = ops->gso_segment(skb, features);
1265 	rcu_read_unlock();
1266 
1267 	if (!segs || IS_ERR(segs))
1268 		goto out;
1269 
1270 	skb = segs;
1271 	do {
1272 		iph = ip_hdr(skb);
1273 		if (proto == IPPROTO_UDP) {
1274 			iph->id = htons(id);
1275 			iph->frag_off = htons(offset >> 3);
1276 			if (skb->next != NULL)
1277 				iph->frag_off |= htons(IP_MF);
1278 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1279 		} else
1280 			iph->id = htons(id++);
1281 		iph->tot_len = htons(skb->len - skb->mac_len);
1282 		iph->check = 0;
1283 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1284 	} while ((skb = skb->next));
1285 
1286 out:
1287 	return segs;
1288 }
1289 
inet_gro_receive(struct sk_buff ** head,struct sk_buff * skb)1290 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1291 					 struct sk_buff *skb)
1292 {
1293 	const struct net_protocol *ops;
1294 	struct sk_buff **pp = NULL;
1295 	struct sk_buff *p;
1296 	struct iphdr *iph;
1297 	unsigned int hlen;
1298 	unsigned int off;
1299 	unsigned int id;
1300 	int flush = 1;
1301 	int proto;
1302 
1303 	off = skb_gro_offset(skb);
1304 	hlen = off + sizeof(*iph);
1305 	iph = skb_gro_header_fast(skb, off);
1306 	if (skb_gro_header_hard(skb, hlen)) {
1307 		iph = skb_gro_header_slow(skb, hlen, off);
1308 		if (unlikely(!iph))
1309 			goto out;
1310 	}
1311 
1312 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1313 
1314 	rcu_read_lock();
1315 	ops = rcu_dereference(inet_protos[proto]);
1316 	if (!ops || !ops->gro_receive)
1317 		goto out_unlock;
1318 
1319 	if (*(u8 *)iph != 0x45)
1320 		goto out_unlock;
1321 
1322 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1323 		goto out_unlock;
1324 
1325 	id = ntohl(*(__be32 *)&iph->id);
1326 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1327 	id >>= 16;
1328 
1329 	for (p = *head; p; p = p->next) {
1330 		struct iphdr *iph2;
1331 
1332 		if (!NAPI_GRO_CB(p)->same_flow)
1333 			continue;
1334 
1335 		iph2 = ip_hdr(p);
1336 
1337 		if ((iph->protocol ^ iph2->protocol) |
1338 		    (iph->tos ^ iph2->tos) |
1339 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1340 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1341 			NAPI_GRO_CB(p)->same_flow = 0;
1342 			continue;
1343 		}
1344 
1345 		/* All fields must match except length and checksum. */
1346 		NAPI_GRO_CB(p)->flush |=
1347 			(iph->ttl ^ iph2->ttl) |
1348 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1349 
1350 		NAPI_GRO_CB(p)->flush |= flush;
1351 	}
1352 
1353 	NAPI_GRO_CB(skb)->flush |= flush;
1354 	skb_gro_pull(skb, sizeof(*iph));
1355 	skb_set_transport_header(skb, skb_gro_offset(skb));
1356 
1357 	pp = ops->gro_receive(head, skb);
1358 
1359 out_unlock:
1360 	rcu_read_unlock();
1361 
1362 out:
1363 	NAPI_GRO_CB(skb)->flush |= flush;
1364 
1365 	return pp;
1366 }
1367 
inet_gro_complete(struct sk_buff * skb)1368 static int inet_gro_complete(struct sk_buff *skb)
1369 {
1370 	const struct net_protocol *ops;
1371 	struct iphdr *iph = ip_hdr(skb);
1372 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1373 	int err = -ENOSYS;
1374 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1375 
1376 	csum_replace2(&iph->check, iph->tot_len, newlen);
1377 	iph->tot_len = newlen;
1378 
1379 	rcu_read_lock();
1380 	ops = rcu_dereference(inet_protos[proto]);
1381 	if (WARN_ON(!ops || !ops->gro_complete))
1382 		goto out_unlock;
1383 
1384 	err = ops->gro_complete(skb);
1385 
1386 out_unlock:
1387 	rcu_read_unlock();
1388 
1389 	return err;
1390 }
1391 
inet_ctl_sock_create(struct sock ** sk,unsigned short family,unsigned short type,unsigned char protocol,struct net * net)1392 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1393 			 unsigned short type, unsigned char protocol,
1394 			 struct net *net)
1395 {
1396 	struct socket *sock;
1397 	int rc = sock_create_kern(family, type, protocol, &sock);
1398 
1399 	if (rc == 0) {
1400 		*sk = sock->sk;
1401 		(*sk)->sk_allocation = GFP_ATOMIC;
1402 		/*
1403 		 * Unhash it so that IP input processing does not even see it,
1404 		 * we do not wish this socket to see incoming packets.
1405 		 */
1406 		(*sk)->sk_prot->unhash(*sk);
1407 
1408 		sk_change_net(*sk, net);
1409 	}
1410 	return rc;
1411 }
1412 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1413 
snmp_fold_field(void __percpu * mib[],int offt)1414 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1415 {
1416 	unsigned long res = 0;
1417 	int i;
1418 
1419 	for_each_possible_cpu(i) {
1420 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1421 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1422 	}
1423 	return res;
1424 }
1425 EXPORT_SYMBOL_GPL(snmp_fold_field);
1426 
1427 #if BITS_PER_LONG==32
1428 
snmp_fold_field64(void __percpu * mib[],int offt,size_t syncp_offset)1429 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1430 {
1431 	u64 res = 0;
1432 	int cpu;
1433 
1434 	for_each_possible_cpu(cpu) {
1435 		void *bhptr, *userptr;
1436 		struct u64_stats_sync *syncp;
1437 		u64 v_bh, v_user;
1438 		unsigned int start;
1439 
1440 		/* first mib used by softirq context, we must use _bh() accessors */
1441 		bhptr = per_cpu_ptr(SNMP_STAT_BHPTR(mib), cpu);
1442 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1443 		do {
1444 			start = u64_stats_fetch_begin_bh(syncp);
1445 			v_bh = *(((u64 *) bhptr) + offt);
1446 		} while (u64_stats_fetch_retry_bh(syncp, start));
1447 
1448 		/* second mib used in USER context */
1449 		userptr = per_cpu_ptr(SNMP_STAT_USRPTR(mib), cpu);
1450 		syncp = (struct u64_stats_sync *)(userptr + syncp_offset);
1451 		do {
1452 			start = u64_stats_fetch_begin(syncp);
1453 			v_user = *(((u64 *) userptr) + offt);
1454 		} while (u64_stats_fetch_retry(syncp, start));
1455 
1456 		res += v_bh + v_user;
1457 	}
1458 	return res;
1459 }
1460 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1461 #endif
1462 
snmp_mib_init(void __percpu * ptr[2],size_t mibsize,size_t align)1463 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1464 {
1465 	BUG_ON(ptr == NULL);
1466 	ptr[0] = __alloc_percpu(mibsize, align);
1467 	if (!ptr[0])
1468 		goto err0;
1469 	ptr[1] = __alloc_percpu(mibsize, align);
1470 	if (!ptr[1])
1471 		goto err1;
1472 	return 0;
1473 err1:
1474 	free_percpu(ptr[0]);
1475 	ptr[0] = NULL;
1476 err0:
1477 	return -ENOMEM;
1478 }
1479 EXPORT_SYMBOL_GPL(snmp_mib_init);
1480 
snmp_mib_free(void __percpu * ptr[2])1481 void snmp_mib_free(void __percpu *ptr[2])
1482 {
1483 	BUG_ON(ptr == NULL);
1484 	free_percpu(ptr[0]);
1485 	free_percpu(ptr[1]);
1486 	ptr[0] = ptr[1] = NULL;
1487 }
1488 EXPORT_SYMBOL_GPL(snmp_mib_free);
1489 
1490 #ifdef CONFIG_IP_MULTICAST
1491 static const struct net_protocol igmp_protocol = {
1492 	.handler =	igmp_rcv,
1493 	.netns_ok =	1,
1494 };
1495 #endif
1496 
1497 static const struct net_protocol tcp_protocol = {
1498 	.handler =	tcp_v4_rcv,
1499 	.err_handler =	tcp_v4_err,
1500 	.gso_send_check = tcp_v4_gso_send_check,
1501 	.gso_segment =	tcp_tso_segment,
1502 	.gro_receive =	tcp4_gro_receive,
1503 	.gro_complete =	tcp4_gro_complete,
1504 	.no_policy =	1,
1505 	.netns_ok =	1,
1506 };
1507 
1508 static const struct net_protocol udp_protocol = {
1509 	.handler =	udp_rcv,
1510 	.err_handler =	udp_err,
1511 	.gso_send_check = udp4_ufo_send_check,
1512 	.gso_segment = udp4_ufo_fragment,
1513 	.no_policy =	1,
1514 	.netns_ok =	1,
1515 };
1516 
1517 static const struct net_protocol icmp_protocol = {
1518 	.handler =	icmp_rcv,
1519 	.no_policy =	1,
1520 	.netns_ok =	1,
1521 };
1522 
ipv4_mib_init_net(struct net * net)1523 static __net_init int ipv4_mib_init_net(struct net *net)
1524 {
1525 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1526 			  sizeof(struct tcp_mib),
1527 			  __alignof__(struct tcp_mib)) < 0)
1528 		goto err_tcp_mib;
1529 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1530 			  sizeof(struct ipstats_mib),
1531 			  __alignof__(struct ipstats_mib)) < 0)
1532 		goto err_ip_mib;
1533 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1534 			  sizeof(struct linux_mib),
1535 			  __alignof__(struct linux_mib)) < 0)
1536 		goto err_net_mib;
1537 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1538 			  sizeof(struct udp_mib),
1539 			  __alignof__(struct udp_mib)) < 0)
1540 		goto err_udp_mib;
1541 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1542 			  sizeof(struct udp_mib),
1543 			  __alignof__(struct udp_mib)) < 0)
1544 		goto err_udplite_mib;
1545 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1546 			  sizeof(struct icmp_mib),
1547 			  __alignof__(struct icmp_mib)) < 0)
1548 		goto err_icmp_mib;
1549 	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1550 			  sizeof(struct icmpmsg_mib),
1551 			  __alignof__(struct icmpmsg_mib)) < 0)
1552 		goto err_icmpmsg_mib;
1553 
1554 	tcp_mib_init(net);
1555 	return 0;
1556 
1557 err_icmpmsg_mib:
1558 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1559 err_icmp_mib:
1560 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1561 err_udplite_mib:
1562 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1563 err_udp_mib:
1564 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1565 err_net_mib:
1566 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1567 err_ip_mib:
1568 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1569 err_tcp_mib:
1570 	return -ENOMEM;
1571 }
1572 
ipv4_mib_exit_net(struct net * net)1573 static __net_exit void ipv4_mib_exit_net(struct net *net)
1574 {
1575 	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1576 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1577 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1578 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1579 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1580 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1581 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1582 }
1583 
1584 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1585 	.init = ipv4_mib_init_net,
1586 	.exit = ipv4_mib_exit_net,
1587 };
1588 
init_ipv4_mibs(void)1589 static int __init init_ipv4_mibs(void)
1590 {
1591 	return register_pernet_subsys(&ipv4_mib_ops);
1592 }
1593 
1594 static int ipv4_proc_init(void);
1595 
1596 /*
1597  *	IP protocol layer initialiser
1598  */
1599 
1600 static struct packet_type ip_packet_type __read_mostly = {
1601 	.type = cpu_to_be16(ETH_P_IP),
1602 	.func = ip_rcv,
1603 	.gso_send_check = inet_gso_send_check,
1604 	.gso_segment = inet_gso_segment,
1605 	.gro_receive = inet_gro_receive,
1606 	.gro_complete = inet_gro_complete,
1607 };
1608 
inet_init(void)1609 static int __init inet_init(void)
1610 {
1611 	struct sk_buff *dummy_skb;
1612 	struct inet_protosw *q;
1613 	struct list_head *r;
1614 	int rc = -EINVAL;
1615 
1616 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1617 
1618 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1619 	if (!sysctl_local_reserved_ports)
1620 		goto out;
1621 
1622 	rc = proto_register(&tcp_prot, 1);
1623 	if (rc)
1624 		goto out_free_reserved_ports;
1625 
1626 	rc = proto_register(&udp_prot, 1);
1627 	if (rc)
1628 		goto out_unregister_tcp_proto;
1629 
1630 	rc = proto_register(&raw_prot, 1);
1631 	if (rc)
1632 		goto out_unregister_udp_proto;
1633 
1634 	/*
1635 	 *	Tell SOCKET that we are alive...
1636 	 */
1637 
1638 	(void)sock_register(&inet_family_ops);
1639 
1640 #ifdef CONFIG_SYSCTL
1641 	ip_static_sysctl_init();
1642 #endif
1643 
1644 	/*
1645 	 *	Add all the base protocols.
1646 	 */
1647 
1648 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1649 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1650 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1651 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1652 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1653 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1654 #ifdef CONFIG_IP_MULTICAST
1655 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1656 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1657 #endif
1658 
1659 	/* Register the socket-side information for inet_create. */
1660 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1661 		INIT_LIST_HEAD(r);
1662 
1663 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1664 		inet_register_protosw(q);
1665 
1666 	/*
1667 	 *	Set the ARP module up
1668 	 */
1669 
1670 	arp_init();
1671 
1672 	/*
1673 	 *	Set the IP module up
1674 	 */
1675 
1676 	ip_init();
1677 
1678 	tcp_v4_init();
1679 
1680 	/* Setup TCP slab cache for open requests. */
1681 	tcp_init();
1682 
1683 	/* Setup UDP memory threshold */
1684 	udp_init();
1685 
1686 	/* Add UDP-Lite (RFC 3828) */
1687 	udplite4_register();
1688 
1689 	/*
1690 	 *	Set the ICMP layer up
1691 	 */
1692 
1693 	if (icmp_init() < 0)
1694 		panic("Failed to create the ICMP control socket.\n");
1695 
1696 	/*
1697 	 *	Initialise the multicast router
1698 	 */
1699 #if defined(CONFIG_IP_MROUTE)
1700 	if (ip_mr_init())
1701 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1702 #endif
1703 	/*
1704 	 *	Initialise per-cpu ipv4 mibs
1705 	 */
1706 
1707 	if (init_ipv4_mibs())
1708 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1709 
1710 	ipv4_proc_init();
1711 
1712 	ipfrag_init();
1713 
1714 	dev_add_pack(&ip_packet_type);
1715 
1716 	rc = 0;
1717 out:
1718 	return rc;
1719 out_unregister_udp_proto:
1720 	proto_unregister(&udp_prot);
1721 out_unregister_tcp_proto:
1722 	proto_unregister(&tcp_prot);
1723 out_free_reserved_ports:
1724 	kfree(sysctl_local_reserved_ports);
1725 	goto out;
1726 }
1727 
1728 fs_initcall(inet_init);
1729 
1730 /* ------------------------------------------------------------------------ */
1731 
1732 #ifdef CONFIG_PROC_FS
ipv4_proc_init(void)1733 static int __init ipv4_proc_init(void)
1734 {
1735 	int rc = 0;
1736 
1737 	if (raw_proc_init())
1738 		goto out_raw;
1739 	if (tcp4_proc_init())
1740 		goto out_tcp;
1741 	if (udp4_proc_init())
1742 		goto out_udp;
1743 	if (ip_misc_proc_init())
1744 		goto out_misc;
1745 out:
1746 	return rc;
1747 out_misc:
1748 	udp4_proc_exit();
1749 out_udp:
1750 	tcp4_proc_exit();
1751 out_tcp:
1752 	raw_proc_exit();
1753 out_raw:
1754 	rc = -ENOMEM;
1755 	goto out;
1756 }
1757 
1758 #else /* CONFIG_PROC_FS */
ipv4_proc_init(void)1759 static int __init ipv4_proc_init(void)
1760 {
1761 	return 0;
1762 }
1763 #endif /* CONFIG_PROC_FS */
1764 
1765 MODULE_ALIAS_NETPROTO(PF_INET);
1766 
1767