udp.c 56.7 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		The User Datagram Protocol (UDP).
 *
8
 * Authors:	Ross Biro
L
Linus Torvalds 已提交
9 10
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11
 *		Alan Cox, <alan@lxorguk.ukuu.org.uk>
L
Linus Torvalds 已提交
12 13 14 15 16 17 18 19 20
 *		Hirokazu Takahashi, <taka@valinux.co.jp>
 *
 * Fixes:
 *		Alan Cox	:	verify_area() calls
 *		Alan Cox	: 	stopped close while in use off icmp
 *					messages. Not a fix but a botch that
 *					for udp at least is 'valid'.
 *		Alan Cox	:	Fixed icmp handling properly
 *		Alan Cox	: 	Correct error for oversized datagrams
21 22
 *		Alan Cox	:	Tidied select() semantics.
 *		Alan Cox	:	udp_err() fixed properly, also now
L
Linus Torvalds 已提交
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
 *					select and read wake correctly on errors
 *		Alan Cox	:	udp_send verify_area moved to avoid mem leak
 *		Alan Cox	:	UDP can count its memory
 *		Alan Cox	:	send to an unknown connection causes
 *					an ECONNREFUSED off the icmp, but
 *					does NOT close.
 *		Alan Cox	:	Switched to new sk_buff handlers. No more backlog!
 *		Alan Cox	:	Using generic datagram code. Even smaller and the PEEK
 *					bug no longer crashes it.
 *		Fred Van Kempen	: 	Net2e support for sk->broadcast.
 *		Alan Cox	:	Uses skb_free_datagram
 *		Alan Cox	:	Added get/set sockopt support.
 *		Alan Cox	:	Broadcasting without option set returns EACCES.
 *		Alan Cox	:	No wakeup calls. Instead we now use the callbacks.
 *		Alan Cox	:	Use ip_tos and ip_ttl
 *		Alan Cox	:	SNMP Mibs
 *		Alan Cox	:	MSG_DONTROUTE, and 0.0.0.0 support.
 *		Matt Dillon	:	UDP length checks.
 *		Alan Cox	:	Smarter af_inet used properly.
 *		Alan Cox	:	Use new kernel side addressing.
 *		Alan Cox	:	Incorrect return on truncated datagram receive.
 *	Arnt Gulbrandsen 	:	New udp_send and stuff
 *		Alan Cox	:	Cache last socket
 *		Alan Cox	:	Route cache
 *		Jon Peatfield	:	Minor efficiency fix to sendto().
 *		Mike Shaver	:	RFC1122 checks.
 *		Alan Cox	:	Nonblocking error fix.
 *	Willy Konynenberg	:	Transparent proxying support.
 *		Mike McLagan	:	Routing by source
 *		David S. Miller	:	New socket lookup architecture.
 *					Last socket cache retained as it
 *					does have a high hit rate.
 *		Olaf Kirch	:	Don't linearise iovec on sendmsg.
 *		Andi Kleen	:	Some cleanups, cache destination entry
57
 *					for connect.
L
Linus Torvalds 已提交
58 59 60 61 62 63 64 65 66 67 68 69 70
 *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
 *		Melvin Smith	:	Check msg_name not msg_namelen in sendto(),
 *					return ENOTCONN for unconnected sockets (POSIX)
 *		Janos Farkas	:	don't deliver multi/broadcasts to a different
 *					bound-to-device socket
 *	Hirokazu Takahashi	:	HW checksumming for outgoing UDP
 *					datagrams.
 *	Hirokazu Takahashi	:	sendfile() on UDP works now.
 *		Arnaldo C. Melo :	convert /proc/net/udp to seq_file
 *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
 *	Alexey Kuznetsov:		allow both IPv4 and IPv6 sockets to bind
 *					a single port at the same time.
 *	Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71
 *	James Chapman		:	Add L2TP encapsulation type.
L
Linus Torvalds 已提交
72 73 74 75 76 77 78
 *
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
79

L
Linus Torvalds 已提交
80 81 82
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
H
Hideo Aoki 已提交
83
#include <linux/bootmem.h>
84 85
#include <linux/highmem.h>
#include <linux/swap.h>
L
Linus Torvalds 已提交
86 87 88 89 90
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/sockios.h>
91
#include <linux/igmp.h>
L
Linus Torvalds 已提交
92 93 94 95 96 97
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
98
#include <linux/slab.h>
99
#include <net/tcp_states.h>
L
Linus Torvalds 已提交
100 101 102
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
103
#include <net/net_namespace.h>
L
Linus Torvalds 已提交
104 105 106 107
#include <net/icmp.h>
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
108
#include "udp_impl.h"
L
Linus Torvalds 已提交
109

110
struct udp_table udp_table __read_mostly;
111
EXPORT_SYMBOL(udp_table);
L
Linus Torvalds 已提交
112

E
Eric Dumazet 已提交
113
long sysctl_udp_mem[3] __read_mostly;
H
Hideo Aoki 已提交
114
EXPORT_SYMBOL(sysctl_udp_mem);
E
Eric Dumazet 已提交
115 116

int sysctl_udp_rmem_min __read_mostly;
H
Hideo Aoki 已提交
117
EXPORT_SYMBOL(sysctl_udp_rmem_min);
E
Eric Dumazet 已提交
118 119

int sysctl_udp_wmem_min __read_mostly;
H
Hideo Aoki 已提交
120 121
EXPORT_SYMBOL(sysctl_udp_wmem_min);

E
Eric Dumazet 已提交
122
atomic_long_t udp_memory_allocated;
H
Hideo Aoki 已提交
123 124
EXPORT_SYMBOL(udp_memory_allocated);

125 126
#define MAX_UDP_PORTS 65536
#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
127

128
static int udp_lib_lport_inuse(struct net *net, __u16 num,
129
			       const struct udp_hslot *hslot,
130
			       unsigned long *bitmap,
131 132
			       struct sock *sk,
			       int (*saddr_comp)(const struct sock *sk1,
133 134
						 const struct sock *sk2),
			       unsigned int log)
L
Linus Torvalds 已提交
135
{
136
	struct sock *sk2;
137
	struct hlist_nulls_node *node;
138

139
	sk_nulls_for_each(sk2, node, &hslot->head)
140 141
		if (net_eq(sock_net(sk2), net) &&
		    sk2 != sk &&
142
		    (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
143 144 145
		    (!sk2->sk_reuse || !sk->sk_reuse) &&
		    (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
		     sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
146 147
		    (*saddr_comp)(sk, sk2)) {
			if (bitmap)
148 149
				__set_bit(udp_sk(sk2)->udp_port_hash >> log,
					  bitmap);
150 151 152
			else
				return 1;
		}
153 154 155
	return 0;
}

E
Eric Dumazet 已提交
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171
/*
 * Note: we still hold spinlock of primary hash chain, so no other writer
 * can insert/delete a socket with local_port == num
 */
static int udp_lib_lport_inuse2(struct net *net, __u16 num,
			       struct udp_hslot *hslot2,
			       struct sock *sk,
			       int (*saddr_comp)(const struct sock *sk1,
						 const struct sock *sk2))
{
	struct sock *sk2;
	struct hlist_nulls_node *node;
	int res = 0;

	spin_lock(&hslot2->lock);
	udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
172 173 174 175 176 177
		if (net_eq(sock_net(sk2), net) &&
		    sk2 != sk &&
		    (udp_sk(sk2)->udp_port_hash == num) &&
		    (!sk2->sk_reuse || !sk->sk_reuse) &&
		    (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
		     sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
E
Eric Dumazet 已提交
178 179 180 181 182 183 184 185
		    (*saddr_comp)(sk, sk2)) {
			res = 1;
			break;
		}
	spin_unlock(&hslot2->lock);
	return res;
}

186
/**
187
 *  udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
188 189 190
 *
 *  @sk:          socket struct in question
 *  @snum:        port number to look up
191
 *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
E
Eric Dumazet 已提交
192 193
 *  @hash2_nulladdr: AF-dependant hash value in secondary hash chains,
 *                   with NULL address
194
 */
195
int udp_lib_get_port(struct sock *sk, unsigned short snum,
196
		       int (*saddr_comp)(const struct sock *sk1,
E
Eric Dumazet 已提交
197 198
					 const struct sock *sk2),
		     unsigned int hash2_nulladdr)
199
{
200
	struct udp_hslot *hslot, *hslot2;
201
	struct udp_table *udptable = sk->sk_prot->h.udp_table;
202
	int    error = 1;
203
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
204

205
	if (!snum) {
E
Eric Dumazet 已提交
206 207
		int low, high, remaining;
		unsigned rand;
208 209
		unsigned short first, last;
		DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
210

211
		inet_get_local_port_range(&low, &high);
212
		remaining = (high - low) + 1;
213

E
Eric Dumazet 已提交
214
		rand = net_random();
215 216 217 218
		first = (((u64)rand * remaining) >> 32) + low;
		/*
		 * force rand to be an odd multiple of UDP_HTABLE_SIZE
		 */
219
		rand = (rand | 1) * (udptable->mask + 1);
E
Eric Dumazet 已提交
220 221
		last = first + udptable->mask + 1;
		do {
222
			hslot = udp_hashslot(udptable, net, first);
223
			bitmap_zero(bitmap, PORTS_PER_CHAIN);
224
			spin_lock_bh(&hslot->lock);
225
			udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
226
					    saddr_comp, udptable->log);
227 228 229 230 231 232 233

			snum = first;
			/*
			 * Iterate on all possible values of snum for this hash.
			 * Using steps of an odd multiple of UDP_HTABLE_SIZE
			 * give us randomization and full range coverage.
			 */
E
Eric Dumazet 已提交
234
			do {
235
				if (low <= snum && snum <= high &&
236 237
				    !test_bit(snum >> udptable->log, bitmap) &&
				    !inet_is_reserved_local_port(snum))
238 239 240 241
					goto found;
				snum += rand;
			} while (snum != first);
			spin_unlock_bh(&hslot->lock);
E
Eric Dumazet 已提交
242
		} while (++first != last);
243
		goto fail;
244
	} else {
245
		hslot = udp_hashslot(udptable, net, snum);
246
		spin_lock_bh(&hslot->lock);
E
Eric Dumazet 已提交
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270
		if (hslot->count > 10) {
			int exist;
			unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;

			slot2          &= udptable->mask;
			hash2_nulladdr &= udptable->mask;

			hslot2 = udp_hashslot2(udptable, slot2);
			if (hslot->count < hslot2->count)
				goto scan_primary_hash;

			exist = udp_lib_lport_inuse2(net, snum, hslot2,
						     sk, saddr_comp);
			if (!exist && (hash2_nulladdr != slot2)) {
				hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
				exist = udp_lib_lport_inuse2(net, snum, hslot2,
							     sk, saddr_comp);
			}
			if (exist)
				goto fail_unlock;
			else
				goto found;
		}
scan_primary_hash:
271 272
		if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
					saddr_comp, 0))
273 274
			goto fail_unlock;
	}
275
found:
E
Eric Dumazet 已提交
276
	inet_sk(sk)->inet_num = snum;
277 278
	udp_sk(sk)->udp_port_hash = snum;
	udp_sk(sk)->udp_portaddr_hash ^= snum;
L
Linus Torvalds 已提交
279
	if (sk_unhashed(sk)) {
280
		sk_nulls_add_node_rcu(sk, &hslot->head);
E
Eric Dumazet 已提交
281
		hslot->count++;
282
		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
283 284 285 286 287 288 289

		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
		spin_lock(&hslot2->lock);
		hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
					 &hslot2->head);
		hslot2->count++;
		spin_unlock(&hslot2->lock);
L
Linus Torvalds 已提交
290
	}
291
	error = 0;
292 293
fail_unlock:
	spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
294
fail:
295 296
	return error;
}
E
Eric Dumazet 已提交
297
EXPORT_SYMBOL(udp_lib_get_port);
298

299
static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
300 301 302
{
	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);

E
Eric Dumazet 已提交
303
	return 	(!ipv6_only_sock(sk2)  &&
E
Eric Dumazet 已提交
304 305
		 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
		   inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
306 307
}

308 309 310
static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
				       unsigned int port)
{
311
	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
312 313
}

314
int udp_v4_get_port(struct sock *sk, unsigned short snum)
315
{
E
Eric Dumazet 已提交
316
	unsigned int hash2_nulladdr =
317
		udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
E
Eric Dumazet 已提交
318 319 320
	unsigned int hash2_partial =
		udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);

321
	/* precompute partial secondary hash */
E
Eric Dumazet 已提交
322 323
	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
	return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
324 325
}

326 327 328 329 330 331
static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
			 unsigned short hnum,
			 __be16 sport, __be32 daddr, __be16 dport, int dif)
{
	int score = -1;

332
	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
333 334 335 336
			!ipv6_only_sock(sk)) {
		struct inet_sock *inet = inet_sk(sk);

		score = (sk->sk_family == PF_INET ? 1 : 0);
E
Eric Dumazet 已提交
337 338
		if (inet->inet_rcv_saddr) {
			if (inet->inet_rcv_saddr != daddr)
339 340 341
				return -1;
			score += 2;
		}
E
Eric Dumazet 已提交
342 343
		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
344 345 346
				return -1;
			score += 2;
		}
E
Eric Dumazet 已提交
347 348
		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
349 350 351 352 353 354 355 356 357 358 359 360
				return -1;
			score += 2;
		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
			score += 2;
		}
	}
	return score;
}

E
Eric Dumazet 已提交
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432
/*
 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
 */
#define SCORE2_MAX (1 + 2 + 2 + 2)
static inline int compute_score2(struct sock *sk, struct net *net,
				 __be32 saddr, __be16 sport,
				 __be32 daddr, unsigned int hnum, int dif)
{
	int score = -1;

	if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
		struct inet_sock *inet = inet_sk(sk);

		if (inet->inet_rcv_saddr != daddr)
			return -1;
		if (inet->inet_num != hnum)
			return -1;

		score = (sk->sk_family == PF_INET ? 1 : 0);
		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
				return -1;
			score += 2;
		}
		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
				return -1;
			score += 2;
		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
			score += 2;
		}
	}
	return score;
}


/* called with read_rcu_lock() */
static struct sock *udp4_lib_lookup2(struct net *net,
		__be32 saddr, __be16 sport,
		__be32 daddr, unsigned int hnum, int dif,
		struct udp_hslot *hslot2, unsigned int slot2)
{
	struct sock *sk, *result;
	struct hlist_nulls_node *node;
	int score, badness;

begin:
	result = NULL;
	badness = -1;
	udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
		score = compute_score2(sk, net, saddr, sport,
				      daddr, hnum, dif);
		if (score > badness) {
			result = sk;
			badness = score;
			if (score == SCORE2_MAX)
				goto exact_match;
		}
	}
	/*
	 * if the nulls value we got at the end of this lookup is
	 * not the expected one, we must restart lookup.
	 * We probably met an item that was moved to another chain.
	 */
	if (get_nulls_value(node) != slot2)
		goto begin;

	if (result) {
exact_match:
E
Eric Dumazet 已提交
433
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
E
Eric Dumazet 已提交
434 435 436 437 438 439 440 441 442 443
			result = NULL;
		else if (unlikely(compute_score2(result, net, saddr, sport,
				  daddr, hnum, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	return result;
}

444 445 446 447 448
/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
 * harder than this. -DaveM
 */
static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
		__be16 sport, __be32 daddr, __be16 dport,
449
		int dif, struct udp_table *udptable)
450
{
451
	struct sock *sk, *result;
452
	struct hlist_nulls_node *node;
453
	unsigned short hnum = ntohs(dport);
E
Eric Dumazet 已提交
454 455
	unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
	struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
456
	int score, badness;
457

458
	rcu_read_lock();
E
Eric Dumazet 已提交
459 460 461 462 463 464 465 466 467 468 469
	if (hslot->count > 10) {
		hash2 = udp4_portaddr_hash(net, daddr, hnum);
		slot2 = hash2 & udptable->mask;
		hslot2 = &udptable->hash2[slot2];
		if (hslot->count < hslot2->count)
			goto begin;

		result = udp4_lib_lookup2(net, saddr, sport,
					  daddr, hnum, dif,
					  hslot2, slot2);
		if (!result) {
470
			hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
E
Eric Dumazet 已提交
471 472 473 474 475
			slot2 = hash2 & udptable->mask;
			hslot2 = &udptable->hash2[slot2];
			if (hslot->count < hslot2->count)
				goto begin;

476
			result = udp4_lib_lookup2(net, saddr, sport,
477
						  htonl(INADDR_ANY), hnum, dif,
E
Eric Dumazet 已提交
478 479 480 481 482
						  hslot2, slot2);
		}
		rcu_read_unlock();
		return result;
	}
483 484 485
begin:
	result = NULL;
	badness = -1;
486
	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
487 488 489 490 491
		score = compute_score(sk, net, saddr, hnum, sport,
				      daddr, dport, dif);
		if (score > badness) {
			result = sk;
			badness = score;
492 493
		}
	}
494 495 496 497 498
	/*
	 * if the nulls value we got at the end of this lookup is
	 * not the expected one, we must restart lookup.
	 * We probably met an item that was moved to another chain.
	 */
E
Eric Dumazet 已提交
499
	if (get_nulls_value(node) != slot)
500 501
		goto begin;

502
	if (result) {
E
Eric Dumazet 已提交
503
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
504 505 506 507 508 509 510 511
			result = NULL;
		else if (unlikely(compute_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
512 513 514
	return result;
}

515 516
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
						 __be16 sport, __be16 dport,
517
						 struct udp_table *udptable)
518
{
519
	struct sock *sk;
520 521
	const struct iphdr *iph = ip_hdr(skb);

522 523 524
	if (unlikely(sk = skb_steal_sock(skb)))
		return sk;
	else
E
Eric Dumazet 已提交
525
		return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
526 527
					 iph->daddr, dport, inet_iif(skb),
					 udptable);
528 529
}

530 531 532
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
533
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
534 535 536
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

537
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
538 539 540 541
					     __be16 loc_port, __be32 loc_addr,
					     __be16 rmt_port, __be32 rmt_addr,
					     int dif)
{
542
	struct hlist_nulls_node *node;
543 544 545
	struct sock *s = sk;
	unsigned short hnum = ntohs(loc_port);

546
	sk_nulls_for_each_from(s, node) {
547 548
		struct inet_sock *inet = inet_sk(s);

549 550 551 552 553 554 555
		if (!net_eq(sock_net(s), net) ||
		    udp_sk(s)->udp_port_hash != hnum ||
		    (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
		    (inet->inet_dport != rmt_port && inet->inet_dport) ||
		    (inet->inet_rcv_saddr &&
		     inet->inet_rcv_saddr != loc_addr) ||
		    ipv6_only_sock(s) ||
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577
		    (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
			continue;
		if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
			continue;
		goto found;
	}
	s = NULL;
found:
	return s;
}

/*
 * This routine is called by the ICMP module when it gets some
 * sort of error condition.  If err < 0 then the socket should
 * be closed and the error returned to the user.  If err > 0
 * it's just the icmp type << 8 | icmp code.
 * Header points to the ip header of the error packet. We move
 * on past this. Then (as it used to claim before adjustment)
 * header points to the first 8 bytes of the udp header.  We need
 * to find the appropriate port.
 */

578
void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
579 580
{
	struct inet_sock *inet;
E
Eric Dumazet 已提交
581 582
	struct iphdr *iph = (struct iphdr *)skb->data;
	struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
583 584 585 586 587
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	int harderr;
	int err;
588
	struct net *net = dev_net(skb->dev);
589

590
	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
591 592
			iph->saddr, uh->source, skb->dev->ifindex, udptable);
	if (sk == NULL) {
593
		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635
		return;	/* No socket for error */
	}

	err = 0;
	harderr = 0;
	inet = inet_sk(sk);

	switch (type) {
	default:
	case ICMP_TIME_EXCEEDED:
		err = EHOSTUNREACH;
		break;
	case ICMP_SOURCE_QUENCH:
		goto out;
	case ICMP_PARAMETERPROB:
		err = EPROTO;
		harderr = 1;
		break;
	case ICMP_DEST_UNREACH:
		if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
			if (inet->pmtudisc != IP_PMTUDISC_DONT) {
				err = EMSGSIZE;
				harderr = 1;
				break;
			}
			goto out;
		}
		err = EHOSTUNREACH;
		if (code <= NR_ICMP_UNREACH) {
			harderr = icmp_err_convert[code].fatal;
			err = icmp_err_convert[code].errno;
		}
		break;
	}

	/*
	 *      RFC1122: OK.  Passes ICMP errors back to application, as per
	 *	4.1.3.3.
	 */
	if (!inet->recverr) {
		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
			goto out;
636
	} else
E
Eric Dumazet 已提交
637
		ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
638

639 640 641 642 643 644 645 646
	sk->sk_err = err;
	sk->sk_error_report(sk);
out:
	sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
647
	__udp4_lib_err(skb, info, &udp_table);
648 649 650 651 652
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
653
void udp_flush_pending_frames(struct sock *sk)
654 655 656 657 658 659 660 661 662
{
	struct udp_sock *up = udp_sk(sk);

	if (up->pending) {
		up->len = 0;
		up->pending = 0;
		ip_flush_pending_frames(sk);
	}
}
663
EXPORT_SYMBOL(udp_flush_pending_frames);
664 665

/**
H
Herbert Xu 已提交
666
 * 	udp4_hwcsum  -  handle outgoing HW checksumming
667 668
 * 	@skb: 	sk_buff containing the filled-in UDP header
 * 	        (checksum field must be zeroed out)
H
Herbert Xu 已提交
669 670
 *	@src:	source IP address
 *	@dst:	destination IP address
671
 */
H
Herbert Xu 已提交
672
static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
673 674
{
	struct udphdr *uh = udp_hdr(skb);
H
Herbert Xu 已提交
675 676 677 678
	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
	int hlen = len;
679 680
	__wsum csum = 0;

H
Herbert Xu 已提交
681
	if (!frags) {
682 683 684 685 686
		/*
		 * Only one fragment on the socket.
		 */
		skb->csum_start = skb_transport_header(skb) - skb->head;
		skb->csum_offset = offsetof(struct udphdr, check);
H
Herbert Xu 已提交
687 688
		uh->check = ~csum_tcpudp_magic(src, dst, len,
					       IPPROTO_UDP, 0);
689 690 691 692 693 694
	} else {
		/*
		 * HW-checksum won't work as there are two or more
		 * fragments on the socket so that all csums of sk_buffs
		 * should be together
		 */
H
Herbert Xu 已提交
695 696 697 698
		do {
			csum = csum_add(csum, frags->csum);
			hlen -= frags->len;
		} while ((frags = frags->next));
699

H
Herbert Xu 已提交
700
		csum = skb_checksum(skb, offset, hlen, csum);
701 702 703 704 705 706 707 708
		skb->ip_summed = CHECKSUM_NONE;

		uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
		if (uh->check == 0)
			uh->check = CSUM_MANGLED_0;
	}
}

H
Herbert Xu 已提交
709
static int udp_send_skb(struct sk_buff *skb, __be32 daddr, __be32 dport)
710
{
H
Herbert Xu 已提交
711
	struct sock *sk = skb->sk;
712 713
	struct inet_sock *inet = inet_sk(sk);
	struct udphdr *uh;
H
Herbert Xu 已提交
714
	struct rtable *rt = (struct rtable *)skb_dst(skb);
715 716
	int err = 0;
	int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
717 718
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
719 720 721 722 723 724
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
725 726 727
	uh->source = inet->inet_sport;
	uh->dest = dport;
	uh->len = htons(len);
728 729 730
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
731
		csum = udplite_csum(skb);
732 733 734 735 736 737 738 739

	else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */

		skb->ip_summed = CHECKSUM_NONE;
		goto send;

	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */

H
Herbert Xu 已提交
740
		udp4_hwcsum(skb, rt->rt_src, daddr);
741 742
		goto send;

H
Herbert Xu 已提交
743 744
	} else
		csum = udp_csum(skb);
745 746

	/* add protocol-dependent pseudo-header */
H
Herbert Xu 已提交
747
	uh->check = csum_tcpudp_magic(rt->rt_src, daddr, len,
E
Eric Dumazet 已提交
748
				      sk->sk_protocol, csum);
749 750 751 752
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
H
Herbert Xu 已提交
753
	err = ip_send_skb(skb);
E
Eric Dumazet 已提交
754 755 756 757 758 759 760 761 762
	if (err) {
		if (err == -ENOBUFS && !inet->recverr) {
			UDP_INC_STATS_USER(sock_net(sk),
					   UDP_MIB_SNDBUFERRORS, is_udplite);
			err = 0;
		}
	} else
		UDP_INC_STATS_USER(sock_net(sk),
				   UDP_MIB_OUTDATAGRAMS, is_udplite);
H
Herbert Xu 已提交
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
	return err;
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
static int udp_push_pending_frames(struct sock *sk)
{
	struct udp_sock  *up = udp_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
	struct flowi *fl = &inet->cork.fl;
	struct sk_buff *skb;
	int err = 0;

	skb = ip_finish_skb(sk);
	if (!skb)
		goto out;

	err = udp_send_skb(skb, fl->fl4_dst, fl->fl_ip_dport);

783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812
out:
	up->len = 0;
	up->pending = 0;
	return err;
}

int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
		size_t len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct udp_sock *up = udp_sk(sk);
	int ulen = len;
	struct ipcm_cookie ipc;
	struct rtable *rt = NULL;
	int free = 0;
	int connected = 0;
	__be32 daddr, faddr, saddr;
	__be16 dport;
	u8  tos;
	int err, is_udplite = IS_UDPLITE(sk);
	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
813
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
814 815 816
		return -EOPNOTSUPP;

	ipc.opt = NULL;
817
	ipc.tx_flags = 0;
818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839

	if (up->pending) {
		/*
		 * There are pending frames.
		 * The socket lock must be held while it's corked.
		 */
		lock_sock(sk);
		if (likely(up->pending)) {
			if (unlikely(up->pending != AF_INET)) {
				release_sock(sk);
				return -EINVAL;
			}
			goto do_append_data;
		}
		release_sock(sk);
	}
	ulen += sizeof(struct udphdr);

	/*
	 *	Get and verify the address.
	 */
	if (msg->msg_name) {
E
Eric Dumazet 已提交
840
		struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
841 842 843 844 845 846 847 848 849 850 851 852 853 854
		if (msg->msg_namelen < sizeof(*usin))
			return -EINVAL;
		if (usin->sin_family != AF_INET) {
			if (usin->sin_family != AF_UNSPEC)
				return -EAFNOSUPPORT;
		}

		daddr = usin->sin_addr.s_addr;
		dport = usin->sin_port;
		if (dport == 0)
			return -EINVAL;
	} else {
		if (sk->sk_state != TCP_ESTABLISHED)
			return -EDESTADDRREQ;
E
Eric Dumazet 已提交
855 856
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
857 858 859 860 861
		/* Open fast path for connected socket.
		   Route will not be used, if at least one option is set.
		 */
		connected = 1;
	}
E
Eric Dumazet 已提交
862
	ipc.addr = inet->inet_saddr;
863 864

	ipc.oif = sk->sk_bound_dev_if;
865
	err = sock_tx_timestamp(sk, &ipc.tx_flags);
866 867
	if (err)
		return err;
868
	if (msg->msg_controllen) {
869
		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
	if (!ipc.opt)
		ipc.opt = inet->opt;

	saddr = ipc.addr;
	ipc.addr = faddr = daddr;

	if (ipc.opt && ipc.opt->srr) {
		if (!daddr)
			return -EINVAL;
		faddr = ipc.opt->faddr;
		connected = 0;
	}
	tos = RT_TOS(inet->tos);
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
	    (ipc.opt && ipc.opt->is_strictroute)) {
		tos |= RTO_ONLINK;
		connected = 0;
	}

	if (ipv4_is_multicast(daddr)) {
		if (!ipc.oif)
			ipc.oif = inet->mc_index;
		if (!saddr)
			saddr = inet->mc_addr;
		connected = 0;
	}

	if (connected)
E
Eric Dumazet 已提交
905
		rt = (struct rtable *)sk_dst_check(sk, 0);
906 907 908

	if (rt == NULL) {
		struct flowi fl = { .oif = ipc.oif,
909
				    .mark = sk->sk_mark,
910 911 912
				    .fl4_dst = faddr,
				    .fl4_src = saddr,
				    .fl4_tos = tos,
913
				    .proto = sk->sk_protocol,
914
				    .flags = inet_sk_flowi_flags(sk),
915 916
				    .fl_ip_sport = inet->inet_sport,
				    .fl_ip_dport = dport };
917 918
		struct net *net = sock_net(sk);

919
		security_sk_classify_flow(sk, &fl);
920
		err = ip_route_output_flow(net, &rt, &fl, sk, 1);
921 922
		if (err) {
			if (err == -ENETUNREACH)
923
				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
924 925 926 927 928 929 930 931
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
932
			sk_dst_set(sk, dst_clone(&rt->dst));
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958
	}

	if (msg->msg_flags&MSG_CONFIRM)
		goto do_confirm;
back_from_confirm:

	saddr = rt->rt_src;
	if (!ipc.addr)
		daddr = ipc.addr = rt->rt_dst;

	lock_sock(sk);
	if (unlikely(up->pending)) {
		/* The socket is already corked while preparing it. */
		/* ... which is an evident application bug. --ANK */
		release_sock(sk);

		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
	inet->cork.fl.fl4_dst = daddr;
	inet->cork.fl.fl_ip_dport = dport;
	inet->cork.fl.fl4_src = saddr;
E
Eric Dumazet 已提交
959
	inet->cork.fl.fl_ip_sport = inet->inet_sport;
960 961 962 963 964 965
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
	err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
966
			sizeof(struct udphdr), &ipc, &rt,
967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
	if (err)
		udp_flush_pending_frames(sk);
	else if (!corkreq)
		err = udp_push_pending_frames(sk);
	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
		up->pending = 0;
	release_sock(sk);

out:
	ip_rt_put(rt);
	if (free)
		kfree(ipc.opt);
	if (!err)
		return len;
	/*
	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
	 * we don't have a good statistic (IpOutDiscards but it can be too many
	 * things).  We could add another new stat but at least for now that
	 * seems like overkill.
	 */
	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
990 991
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
992 993 994 995
	}
	return err;

do_confirm:
996
	dst_confirm(&rt->dst);
997 998 999 1000 1001
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1002
EXPORT_SYMBOL(udp_sendmsg);
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
	struct udp_sock *up = udp_sk(sk);
	int ret;

	if (!up->pending) {
		struct msghdr msg = {	.msg_flags = flags|MSG_MORE };

		/* Call udp_sendmsg to specify destination address which
		 * sendpage interface can't pass.
		 * This will succeed only when the socket is connected.
		 */
		ret = udp_sendmsg(NULL, sk, &msg, 0);
		if (ret < 0)
			return ret;
	}

	lock_sock(sk);

	if (unlikely(!up->pending)) {
		release_sock(sk);

		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
		return -EINVAL;
	}

	ret = ip_append_page(sk, page, offset, size, flags);
	if (ret == -EOPNOTSUPP) {
		release_sock(sk);
		return sock_no_sendpage(sk->sk_socket, page, offset,
					size, flags);
	}
	if (ret < 0) {
		udp_flush_pending_frames(sk);
		goto out;
	}

	up->len += size;
	if (!(up->corkflag || (flags&MSG_MORE)))
		ret = udp_push_pending_frames(sk);
	if (!ret)
		ret = size;
out:
	release_sock(sk);
	return ret;
}

E
Eric Dumazet 已提交
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072

/**
 *	first_packet_length	- return length of first packet in receive queue
 *	@sk: socket
 *
 *	Drops all bad checksum frames, until a valid one is found.
 *	Returns the length of found skb, or 0 if none is found.
 */
static unsigned int first_packet_length(struct sock *sk)
{
	struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
	struct sk_buff *skb;
	unsigned int res;

	__skb_queue_head_init(&list_kill);

	spin_lock_bh(&rcvq->lock);
	while ((skb = skb_peek(rcvq)) != NULL &&
		udp_lib_checksum_complete(skb)) {
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1073
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1074 1075 1076 1077 1078 1079 1080
		__skb_unlink(skb, rcvq);
		__skb_queue_tail(&list_kill, skb);
	}
	res = skb ? skb->len : 0;
	spin_unlock_bh(&rcvq->lock);

	if (!skb_queue_empty(&list_kill)) {
1081 1082
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1083 1084
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1085
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1086 1087 1088 1089
	}
	return res;
}

L
Linus Torvalds 已提交
1090 1091 1092
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1093

L
Linus Torvalds 已提交
1094 1095
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1096 1097
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1098
	{
1099 1100
		int amount = sk_wmem_alloc_get(sk);

1101 1102
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1103

1104 1105
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1106
		unsigned int amount = first_packet_length(sk);
1107

E
Eric Dumazet 已提交
1108
		if (amount)
1109 1110 1111 1112 1113
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1114 1115
			amount -= sizeof(struct udphdr);

1116 1117
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1118

1119 1120
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1121
	}
1122 1123

	return 0;
L
Linus Torvalds 已提交
1124
}
E
Eric Dumazet 已提交
1125
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1126

1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
/*
 * 	This should be easy, if there is something there we
 * 	return it, otherwise we block.
 */

int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
		size_t len, int noblock, int flags, int *addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
	struct sk_buff *skb;
G
Gerrit Renker 已提交
1138
	unsigned int ulen;
1139 1140 1141
	int peeked;
	int err;
	int is_udplite = IS_UDPLITE(sk);
1142
	bool slow;
1143 1144 1145 1146 1147

	/*
	 *	Check any passed addresses
	 */
	if (addr_len)
E
Eric Dumazet 已提交
1148
		*addr_len = sizeof(*sin);
1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159

	if (flags & MSG_ERRQUEUE)
		return ip_recv_error(sk, msg, len);

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
				  &peeked, &err);
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
G
Gerrit Renker 已提交
1160 1161 1162
	if (len > ulen)
		len = ulen;
	else if (len < ulen)
1163 1164 1165 1166 1167 1168 1169 1170
		msg->msg_flags |= MSG_TRUNC;

	/*
	 * If checksum is needed at all, try to do it while copying the
	 * data.  If the data is truncated, or if we only want a partial
	 * coverage checksum (UDP-Lite), do it before the copy.
	 */

G
Gerrit Renker 已提交
1171
	if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {
1172 1173 1174 1175 1176 1177
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
G
Gerrit Renker 已提交
1178
					      msg->msg_iov, len);
1179
	else {
E
Eric Dumazet 已提交
1180 1181 1182
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1183 1184 1185 1186 1187 1188 1189 1190 1191

		if (err == -EINVAL)
			goto csum_copy_err;
	}

	if (err)
		goto out_free;

	if (!peeked)
1192 1193
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1194

1195
	sock_recv_ts_and_drops(msg, sk, skb);
1196 1197

	/* Copy the address. */
E
Eric Dumazet 已提交
1198
	if (sin) {
1199 1200 1201 1202 1203 1204 1205 1206
		sin->sin_family = AF_INET;
		sin->sin_port = udp_hdr(skb)->source;
		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
		memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);

G
Gerrit Renker 已提交
1207
	err = len;
1208 1209 1210 1211
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1212
	skb_free_datagram_locked(sk, skb);
1213 1214 1215 1216
out:
	return err;

csum_copy_err:
1217
	slow = lock_sock_fast(sk);
1218
	if (!skb_kill_datagram(sk, skb, flags))
1219
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1220
	unlock_sock_fast(sk, slow);
1221 1222 1223 1224 1225 1226 1227

	if (noblock)
		return -EAGAIN;
	goto try_again;
}


L
Linus Torvalds 已提交
1228 1229 1230 1231 1232 1233
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1234

L
Linus Torvalds 已提交
1235
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1236 1237
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1238
	sock_rps_save_rxhash(sk, 0);
L
Linus Torvalds 已提交
1239 1240 1241 1242 1243 1244
	sk->sk_bound_dev_if = 0;
	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
		inet_reset_saddr(sk);

	if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
		sk->sk_prot->unhash(sk);
E
Eric Dumazet 已提交
1245
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1246 1247 1248 1249
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1250
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1251

1252 1253
void udp_lib_unhash(struct sock *sk)
{
1254 1255
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1256 1257 1258 1259 1260
		struct udp_hslot *hslot, *hslot2;

		hslot  = udp_hashslot(udptable, sock_net(sk),
				      udp_sk(sk)->udp_port_hash);
		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1261

1262 1263
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1264
			hslot->count--;
E
Eric Dumazet 已提交
1265
			inet_sk(sk)->inet_num = 0;
1266
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1267 1268 1269 1270 1271

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1272 1273
		}
		spin_unlock_bh(&hslot->lock);
1274 1275 1276 1277
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320
/*
 * inet_rcv_saddr was changed, we must rehash secondary hash
 */
void udp_lib_rehash(struct sock *sk, u16 newhash)
{
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
		struct udp_hslot *hslot, *hslot2, *nhslot2;

		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
		nhslot2 = udp_hashslot2(udptable, newhash);
		udp_sk(sk)->udp_portaddr_hash = newhash;
		if (hslot2 != nhslot2) {
			hslot = udp_hashslot(udptable, sock_net(sk),
					     udp_sk(sk)->udp_port_hash);
			/* we must lock primary chain too */
			spin_lock_bh(&hslot->lock);

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);

			spin_lock(&nhslot2->lock);
			hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
						 &nhslot2->head);
			nhslot2->count++;
			spin_unlock(&nhslot2->lock);

			spin_unlock_bh(&hslot->lock);
		}
	}
}
EXPORT_SYMBOL(udp_lib_rehash);

static void udp_v4_rehash(struct sock *sk)
{
	u16 new_hash = udp4_portaddr_hash(sock_net(sk),
					  inet_sk(sk)->inet_rcv_saddr,
					  inet_sk(sk)->inet_num);
	udp_lib_rehash(sk, new_hash);
}

H
Herbert Xu 已提交
1321 1322
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1323
	int rc;
E
Eric Dumazet 已提交
1324

T
Tom Herbert 已提交
1325
	if (inet_sk(sk)->inet_daddr)
1326
		sock_rps_save_rxhash(sk, skb->rxhash);
T
Tom Herbert 已提交
1327

E
Eric Dumazet 已提交
1328
	rc = ip_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1329 1330
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1331 1332

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1333
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1334 1335
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1336 1337 1338
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
		return -1;
H
Herbert Xu 已提交
1339 1340 1341 1342 1343 1344
	}

	return 0;

}

1345 1346 1347 1348 1349 1350 1351 1352
/* returns:
 *  -1: error
 *   0: success
 *  >0: "udp encap" protocol resubmission
 *
 * Note that in the success and error cases, the skb is assumed to
 * have either been requeued or freed.
 */
E
Eric Dumazet 已提交
1353
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384
{
	struct udp_sock *up = udp_sk(sk);
	int rc;
	int is_udplite = IS_UDPLITE(sk);

	/*
	 *	Charge it to the socket, dropping if the queue is full.
	 */
	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
		goto drop;
	nf_reset(skb);

	if (up->encap_type) {
		/*
		 * This is an encapsulation socket so pass the skb to
		 * the socket's udp_encap_rcv() hook. Otherwise, just
		 * fall through and pass this up the UDP socket.
		 * up->encap_rcv() returns the following value:
		 * =0 if skb was successfully passed to the encap
		 *    handler or was discarded by it.
		 * >0 if skb should be passed on to UDP.
		 * <0 if skb should be resubmitted as proto -N
		 */

		/* if we're overly short, let UDP handle it */
		if (skb->len > sizeof(struct udphdr) &&
		    up->encap_rcv != NULL) {
			int ret;

			ret = (*up->encap_rcv)(sk, skb);
			if (ret <= 0) {
1385 1386
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430
						 is_udplite);
				return -ret;
			}
		}

		/* FALLTHROUGH -- it's a UDP Packet */
	}

	/*
	 * 	UDP-Lite specific tests, ignored on UDP sockets
	 */
	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {

		/*
		 * MIB statistics other than incrementing the error count are
		 * disabled for the following two types of errors: these depend
		 * on the application settings, not on the functioning of the
		 * protocol stack as such.
		 *
		 * RFC 3828 here recommends (sec 3.3): "There should also be a
		 * way ... to ... at least let the receiving application block
		 * delivery of packets with coverage values less than a value
		 * provided by the application."
		 */
		if (up->pcrlen == 0) {          /* full coverage was set  */
			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
				"%d while full coverage %d requested\n",
				UDP_SKB_CB(skb)->cscov, skb->len);
			goto drop;
		}
		/* The next case involves violating the min. coverage requested
		 * by the receiver. This is subtle: if receiver wants x and x is
		 * greater than the buffersize/MTU then receiver will complain
		 * that it wants x while sender emits packets of smaller size y.
		 * Therefore the above ...()->partial_cov statement is essential.
		 */
		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
			LIMIT_NETDEBUG(KERN_WARNING
				"UDPLITE: coverage %d too small, need min %d\n",
				UDP_SKB_CB(skb)->cscov, up->pcrlen);
			goto drop;
		}
	}

1431
	if (rcu_dereference_raw(sk->sk_filter)) {
1432 1433 1434 1435
		if (udp_lib_checksum_complete(skb))
			goto drop;
	}

1436 1437 1438 1439

	if (sk_rcvqueues_full(sk, skb))
		goto drop;

H
Herbert Xu 已提交
1440
	rc = 0;
1441

H
Herbert Xu 已提交
1442 1443 1444
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
Z
Zhu Yi 已提交
1445
	else if (sk_add_backlog(sk, skb)) {
Z
Zhu Yi 已提交
1446 1447 1448
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1449 1450 1451
	bh_unlock_sock(sk);

	return rc;
1452 1453

drop:
1454
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1455
	atomic_inc(&sk->sk_drops);
1456 1457 1458 1459
	kfree_skb(skb);
	return -1;
}

1460 1461 1462 1463 1464 1465

static void flush_stack(struct sock **stack, unsigned int count,
			struct sk_buff *skb, unsigned int final)
{
	unsigned int i;
	struct sk_buff *skb1 = NULL;
1466
	struct sock *sk;
1467 1468

	for (i = 0; i < count; i++) {
1469
		sk = stack[i];
1470 1471 1472
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1473 1474 1475 1476 1477 1478 1479 1480 1481
		if (!skb1) {
			atomic_inc(&sk->sk_drops);
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 IS_UDPLITE(sk));
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
					 IS_UDPLITE(sk));
		}

		if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1482 1483 1484 1485 1486 1487
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1488 1489 1490
/*
 *	Multicasts and broadcasts go to each listener.
 *
1491
 *	Note: called only from the BH handler context.
1492
 */
1493
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1494 1495
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1496
				    struct udp_table *udptable)
1497
{
1498
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1499
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1500
	int dif;
1501
	unsigned int i, count = 0;
1502

1503
	spin_lock(&hslot->lock);
1504
	sk = sk_nulls_head(&hslot->head);
1505
	dif = skb->dev->ifindex;
1506
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
	while (sk) {
		stack[count++] = sk;
		sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
				       daddr, uh->source, saddr, dif);
		if (unlikely(count == ARRAY_SIZE(stack))) {
			if (!sk)
				break;
			flush_stack(stack, count, skb, ~0);
			count = 0;
		}
	}
	/*
	 * before releasing chain lock, we must take a reference on sockets
	 */
	for (i = 0; i < count; i++)
		sock_hold(stack[i]);

1524
	spin_unlock(&hslot->lock);
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536

	/*
	 * do the slow work with no lock held
	 */
	if (count) {
		flush_stack(stack, count, skb, count - 1);

		for (i = 0; i < count; i++)
			sock_put(stack[i]);
	} else {
		kfree_skb(skb);
	}
1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563
	return 0;
}

/* Initialize UDP checksum. If exited with zero value (success),
 * CHECKSUM_UNNECESSARY means, that no more checks are required.
 * Otherwise, csum completion requires chacksumming packet body,
 * including udp header and folding it to skb->csum.
 */
static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
				 int proto)
{
	const struct iphdr *iph;
	int err;

	UDP_SKB_CB(skb)->partial_cov = 0;
	UDP_SKB_CB(skb)->cscov = skb->len;

	if (proto == IPPROTO_UDPLITE) {
		err = udplite_checksum_init(skb, uh);
		if (err)
			return err;
	}

	iph = ip_hdr(skb);
	if (uh->check == 0) {
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
E
Eric Dumazet 已提交
1564
		if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581
				      proto, skb->csum))
			skb->ip_summed = CHECKSUM_UNNECESSARY;
	}
	if (!skb_csum_unnecessary(skb))
		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
					       skb->len, proto, 0);
	/* Probably, we should checksum udp header (it should be in cache
	 * in any case) and data in tiny packets (< rx copybreak).
	 */

	return 0;
}

/*
 *	All we need to do is get the socket, and then do a checksum.
 */

1582
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1583 1584 1585
		   int proto)
{
	struct sock *sk;
1586
	struct udphdr *uh;
1587
	unsigned short ulen;
E
Eric Dumazet 已提交
1588
	struct rtable *rt = skb_rtable(skb);
1589
	__be32 saddr, daddr;
1590
	struct net *net = dev_net(skb->dev);
1591 1592 1593 1594 1595 1596 1597

	/*
	 *  Validate the packet.
	 */
	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
		goto drop;		/* No space for header. */

1598
	uh   = udp_hdr(skb);
1599
	ulen = ntohs(uh->len);
1600 1601 1602
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616
	if (ulen > skb->len)
		goto short_packet;

	if (proto == IPPROTO_UDP) {
		/* UDP validates ulen. */
		if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
			goto short_packet;
		uh = udp_hdr(skb);
	}

	if (udp4_csum_init(skb, uh, proto))
		goto csum_error;

	if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1617 1618
		return __udp4_lib_mcast_deliver(net, skb, uh,
				saddr, daddr, udptable);
1619

1620
	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1621 1622

	if (sk != NULL) {
H
Herbert Xu 已提交
1623
		int ret = udp_queue_rcv_skb(sk, skb);
1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641
		sock_put(sk);

		/* a return value > 0 means to resubmit the input, but
		 * it wants the return to be -protocol, or 0
		 */
		if (ret > 0)
			return -ret;
		return 0;
	}

	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
		goto drop;
	nf_reset(skb);

	/* No socket. Drop packet silently, if checksum is wrong */
	if (udp_lib_checksum_complete(skb))
		goto csum_error;

1642
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1643 1644 1645 1646 1647 1648 1649 1650 1651 1652
	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);

	/*
	 * Hmm.  We got an UDP packet to a port to which we
	 * don't wanna listen.  Ignore it.
	 */
	kfree_skb(skb);
	return 0;

short_packet:
1653
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1654
		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
1655
		       &saddr,
1656 1657 1658
		       ntohs(uh->source),
		       ulen,
		       skb->len,
1659
		       &daddr,
1660 1661 1662 1663 1664 1665 1666 1667
		       ntohs(uh->dest));
	goto drop;

csum_error:
	/*
	 * RFC1122: OK.  Discards the bad packet silently (as far as
	 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
	 */
1668
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1669
		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
1670
		       &saddr,
1671
		       ntohs(uh->source),
1672
		       &daddr,
1673 1674 1675
		       ntohs(uh->dest),
		       ulen);
drop:
1676
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1677 1678 1679 1680 1681 1682
	kfree_skb(skb);
	return 0;
}

int udp_rcv(struct sk_buff *skb)
{
1683
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1684 1685
}

1686
void udp_destroy_sock(struct sock *sk)
1687
{
1688
	bool slow = lock_sock_fast(sk);
1689
	udp_flush_pending_frames(sk);
1690
	unlock_sock_fast(sk, slow);
1691 1692
}

L
Linus Torvalds 已提交
1693 1694 1695
/*
 *	Socket option code for UDP
 */
1696
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1697
		       char __user *optval, unsigned int optlen,
1698
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1699 1700 1701 1702
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1703
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1704

E
Eric Dumazet 已提交
1705
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1706 1707 1708 1709 1710
		return -EINVAL;

	if (get_user(val, (int __user *)optval))
		return -EFAULT;

1711
	switch (optname) {
L
Linus Torvalds 已提交
1712 1713 1714 1715 1716 1717
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1718
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1719 1720 1721
			release_sock(sk);
		}
		break;
1722

L
Linus Torvalds 已提交
1723 1724 1725 1726 1727
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1728 1729
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
1730
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
1731 1732 1733 1734 1735 1736 1737 1738
			up->encap_type = val;
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

1739 1740 1741 1742 1743 1744
	/*
	 * 	UDP-Lite's partial checksum coverage (RFC 3828).
	 */
	/* The sender sets actual checksum coverage length via this option.
	 * The case coverage > packet length is handled by send module. */
	case UDPLITE_SEND_CSCOV:
W
Wang Chen 已提交
1745
		if (!is_udplite)         /* Disable the option on UDP sockets */
1746 1747 1748
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
1749 1750
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1751 1752 1753 1754
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

1755 1756
	/* The receiver specifies a minimum checksum coverage value. To make
	 * sense, this should be set to at least 8 (as done below). If zero is
1757 1758
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
1759
		if (!is_udplite)         /* Disable the option on UDP sockets */
1760 1761 1762
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
1763 1764
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1765 1766 1767 1768
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
1769 1770 1771
	default:
		err = -ENOPROTOOPT;
		break;
1772
	}
L
Linus Torvalds 已提交
1773 1774 1775

	return err;
}
E
Eric Dumazet 已提交
1776
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
1777

1778
int udp_setsockopt(struct sock *sk, int level, int optname,
1779
		   char __user *optval, unsigned int optlen)
1780 1781 1782 1783 1784 1785 1786 1787 1788
{
	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
					  udp_push_pending_frames);
	return ip_setsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1789
			  char __user *optval, unsigned int optlen)
1790 1791 1792 1793 1794 1795 1796 1797
{
	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
					  udp_push_pending_frames);
	return compat_ip_setsockopt(sk, level, optname, optval, optlen);
}
#endif

1798 1799
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
1800 1801 1802 1803
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
1804
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
1805 1806 1807
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
1808

1809
	if (len < 0)
L
Linus Torvalds 已提交
1810 1811
		return -EINVAL;

1812
	switch (optname) {
L
Linus Torvalds 已提交
1813 1814 1815 1816 1817 1818 1819 1820
	case UDP_CORK:
		val = up->corkflag;
		break;

	case UDP_ENCAP:
		val = up->encap_type;
		break;

1821 1822 1823 1824 1825 1826 1827 1828 1829 1830
	/* The following two cannot be changed on UDP sockets, the return is
	 * always 0 (which corresponds to the full checksum coverage of UDP). */
	case UDPLITE_SEND_CSCOV:
		val = up->pcslen;
		break;

	case UDPLITE_RECV_CSCOV:
		val = up->pcrlen;
		break;

L
Linus Torvalds 已提交
1831 1832
	default:
		return -ENOPROTOOPT;
1833
	}
L
Linus Torvalds 已提交
1834

1835
	if (put_user(len, optlen))
1836
		return -EFAULT;
E
Eric Dumazet 已提交
1837
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
1838
		return -EFAULT;
1839
	return 0;
L
Linus Torvalds 已提交
1840
}
E
Eric Dumazet 已提交
1841
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
1842

1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
int udp_getsockopt(struct sock *sk, int level, int optname,
		   char __user *optval, int __user *optlen)
{
	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
	return ip_getsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
int compat_udp_getsockopt(struct sock *sk, int level, int optname,
				 char __user *optval, int __user *optlen)
{
	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
	return compat_ip_getsockopt(sk, level, optname, optval, optlen);
}
#endif
L
Linus Torvalds 已提交
1860 1861 1862 1863 1864 1865
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
1866
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876
 *	blocking sockets. If application is using a blocking fd
 *	and a packet with checksum error is in the queue;
 *	then it could get return from select indicating data available
 *	but then block when reading it. Add special case code
 *	to work around these arguably broken applications.
 */
unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
{
	unsigned int mask = datagram_poll(file, sock, wait);
	struct sock *sk = sock->sk;
1877

L
Linus Torvalds 已提交
1878
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
1879 1880 1881
	if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
	    !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
		mask &= ~(POLLIN | POLLRDNORM);
L
Linus Torvalds 已提交
1882 1883

	return mask;
1884

L
Linus Torvalds 已提交
1885
}
E
Eric Dumazet 已提交
1886
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
1887

1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
struct proto udp_prot = {
	.name		   = "UDP",
	.owner		   = THIS_MODULE,
	.close		   = udp_lib_close,
	.connect	   = ip4_datagram_connect,
	.disconnect	   = udp_disconnect,
	.ioctl		   = udp_ioctl,
	.destroy	   = udp_destroy_sock,
	.setsockopt	   = udp_setsockopt,
	.getsockopt	   = udp_getsockopt,
	.sendmsg	   = udp_sendmsg,
	.recvmsg	   = udp_recvmsg,
	.sendpage	   = udp_sendpage,
H
Herbert Xu 已提交
1901
	.backlog_rcv	   = __udp_queue_rcv_skb,
1902 1903
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
1904
	.rehash		   = udp_v4_rehash,
1905 1906 1907 1908 1909 1910
	.get_port	   = udp_v4_get_port,
	.memory_allocated  = &udp_memory_allocated,
	.sysctl_mem	   = sysctl_udp_mem,
	.sysctl_wmem	   = &sysctl_udp_wmem_min,
	.sysctl_rmem	   = &sysctl_udp_rmem_min,
	.obj_size	   = sizeof(struct udp_sock),
1911
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1912
	.h.udp_table	   = &udp_table,
1913 1914 1915 1916
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
1917
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
1918
};
E
Eric Dumazet 已提交
1919
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
1920 1921 1922 1923

/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS

1924
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
1925 1926 1927
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
1928
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1929

1930 1931
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
1932
		struct hlist_nulls_node *node;
1933
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1934 1935 1936 1937

		if (hlist_nulls_empty(&hslot->head))
			continue;

1938
		spin_lock_bh(&hslot->lock);
1939
		sk_nulls_for_each(sk, node, &hslot->head) {
1940
			if (!net_eq(sock_net(sk), net))
1941
				continue;
L
Linus Torvalds 已提交
1942 1943 1944
			if (sk->sk_family == state->family)
				goto found;
		}
1945
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
1946 1947 1948 1949 1950 1951 1952 1953 1954
	}
	sk = NULL;
found:
	return sk;
}

static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
{
	struct udp_iter_state *state = seq->private;
1955
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1956 1957

	do {
1958
		sk = sk_nulls_next(sk);
1959
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
1960

1961
	if (!sk) {
1962
		if (state->bucket <= state->udp_table->mask)
1963
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1964
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
1965 1966 1967 1968 1969 1970
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
1971
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
1972 1973

	if (sk)
1974
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
1975 1976 1977 1978 1979 1980
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
1981
	struct udp_iter_state *state = seq->private;
1982
	state->bucket = MAX_UDP_PORTS;
1983

1984
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
1985 1986 1987 1988 1989 1990
}

static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct sock *sk;

1991
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
		sk = udp_get_idx(seq, 0);
	else
		sk = udp_get_next(seq, v);

	++*pos;
	return sk;
}

static void udp_seq_stop(struct seq_file *seq, void *v)
{
2002 2003
	struct udp_iter_state *state = seq->private;

2004
	if (state->bucket <= state->udp_table->mask)
2005
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2006 2007 2008 2009 2010
}

static int udp_seq_open(struct inode *inode, struct file *file)
{
	struct udp_seq_afinfo *afinfo = PDE(inode)->data;
2011 2012
	struct udp_iter_state *s;
	int err;
2013

2014 2015 2016 2017
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2018

2019
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2020
	s->family		= afinfo->family;
2021
	s->udp_table		= afinfo->udp_table;
2022
	return err;
2023 2024
}

L
Linus Torvalds 已提交
2025
/* ------------------------------------------------------------------------ */
2026
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2027 2028 2029 2030
{
	struct proc_dir_entry *p;
	int rc = 0;

2031 2032 2033 2034
	afinfo->seq_fops.open		= udp_seq_open;
	afinfo->seq_fops.read		= seq_read;
	afinfo->seq_fops.llseek		= seq_lseek;
	afinfo->seq_fops.release	= seq_release_net;
L
Linus Torvalds 已提交
2035

2036 2037 2038 2039
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2040 2041 2042
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
			     &afinfo->seq_fops, afinfo);
	if (!p)
L
Linus Torvalds 已提交
2043 2044 2045
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2046
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2047

2048
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2049
{
2050
	proc_net_remove(net, afinfo->name);
L
Linus Torvalds 已提交
2051
}
E
Eric Dumazet 已提交
2052
EXPORT_SYMBOL(udp_proc_unregister);
2053 2054

/* ------------------------------------------------------------------------ */
2055 2056
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
		int bucket, int *len)
2057 2058
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2059 2060 2061 2062
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2063

2064
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
E
Eric Dumazet 已提交
2065
		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
2066
		bucket, src, srcp, dest, destp, sp->sk_state,
2067 2068
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2069
		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
E
Eric Dumazet 已提交
2070 2071
		atomic_read(&sp->sk_refcnt), sp,
		atomic_read(&sp->sk_drops), len);
2072 2073 2074 2075 2076 2077 2078 2079
}

int udp4_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_printf(seq, "%-127s\n",
			   "  sl  local_address rem_address   st tx_queue "
			   "rx_queue tr tm->when retrnsmt   uid  timeout "
E
Eric Dumazet 已提交
2080
			   "inode ref pointer drops");
2081 2082
	else {
		struct udp_iter_state *state = seq->private;
2083
		int len;
2084

2085
		udp4_format_sock(v, seq, state->bucket, &len);
E
Eric Dumazet 已提交
2086
		seq_printf(seq, "%*s\n", 127 - len, "");
2087 2088 2089 2090 2091 2092 2093 2094
	}
	return 0;
}

/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2095
	.udp_table	= &udp_table,
2096 2097 2098
	.seq_fops	= {
		.owner	=	THIS_MODULE,
	},
2099 2100 2101
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2102 2103
};

2104
static int __net_init udp4_proc_init_net(struct net *net)
2105 2106 2107 2108
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2109
static void __net_exit udp4_proc_exit_net(struct net *net)
2110 2111 2112 2113 2114 2115 2116 2117 2118
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

static struct pernet_operations udp4_net_ops = {
	.init = udp4_proc_init_net,
	.exit = udp4_proc_exit_net,
};

2119 2120
int __init udp4_proc_init(void)
{
2121
	return register_pernet_subsys(&udp4_net_ops);
2122 2123 2124 2125
}

void udp4_proc_exit(void)
{
2126
	unregister_pernet_subsys(&udp4_net_ops);
2127
}
L
Linus Torvalds 已提交
2128 2129
#endif /* CONFIG_PROC_FS */

2130 2131
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2132
{
2133 2134 2135 2136 2137 2138 2139 2140
	if (!str)
		return 0;
	uhash_entries = simple_strtoul(str, &str, 0);
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2141

2142 2143 2144 2145 2146 2147
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

	if (!CONFIG_BASE_SMALL)
		table->hash = alloc_large_system_hash(name,
2148
			2 * sizeof(struct udp_hslot),
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159
			uhash_entries,
			21, /* one slot per 2 MB */
			0,
			&table->log,
			&table->mask,
			64 * 1024);
	/*
	 * Make sure hash table has the minimum size
	 */
	if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
		table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
2160
				      2 * sizeof(struct udp_hslot), GFP_KERNEL);
2161 2162 2163 2164 2165
		if (!table->hash)
			panic(name);
		table->log = ilog2(UDP_HTABLE_SIZE_MIN);
		table->mask = UDP_HTABLE_SIZE_MIN - 1;
	}
2166
	table->hash2 = table->hash + (table->mask + 1);
2167
	for (i = 0; i <= table->mask; i++) {
2168
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2169
		table->hash[i].count = 0;
2170 2171
		spin_lock_init(&table->hash[i].lock);
	}
2172 2173 2174 2175 2176
	for (i = 0; i <= table->mask; i++) {
		INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
		table->hash2[i].count = 0;
		spin_lock_init(&table->hash2[i].lock);
	}
2177 2178
}

H
Hideo Aoki 已提交
2179 2180
void __init udp_init(void)
{
2181
	unsigned long nr_pages, limit;
H
Hideo Aoki 已提交
2182

2183
	udp_table_init(&udp_table, "UDP");
H
Hideo Aoki 已提交
2184 2185 2186 2187
	/* Set the pressure threshold up by the same strategy of TCP. It is a
	 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
	 * toward zero with the amount of memory, with a floor of 128 pages.
	 */
2188 2189 2190
	nr_pages = totalram_pages - totalhigh_pages;
	limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
	limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
H
Hideo Aoki 已提交
2191 2192 2193 2194 2195 2196 2197 2198 2199
	limit = max(limit, 128UL);
	sysctl_udp_mem[0] = limit / 4 * 3;
	sysctl_udp_mem[1] = limit;
	sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;

	sysctl_udp_rmem_min = SK_MEM_QUANTUM;
	sysctl_udp_wmem_min = SK_MEM_QUANTUM;
}

2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
int udp4_ufo_send_check(struct sk_buff *skb)
{
	const struct iphdr *iph;
	struct udphdr *uh;

	if (!pskb_may_pull(skb, sizeof(*uh)))
		return -EINVAL;

	iph = ip_hdr(skb);
	uh = udp_hdr(skb);

	uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
				       IPPROTO_UDP, 0);
	skb->csum_start = skb_transport_header(skb) - skb->head;
	skb->csum_offset = offsetof(struct udphdr, check);
	skb->ip_summed = CHECKSUM_PARTIAL;
	return 0;
}

2219
struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, u32 features)
2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	unsigned int mss;
	int offset;
	__wsum csum;

	mss = skb_shinfo(skb)->gso_size;
	if (unlikely(skb->len <= mss))
		goto out;

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		int type = skb_shinfo(skb)->gso_type;

		if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
			     !(type & (SKB_GSO_UDP))))
			goto out;

		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);

		segs = NULL;
		goto out;
	}

	/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
	 * do checksum of UDP packets sent as multiple IP fragments.
	 */
2247
	offset = skb_checksum_start_offset(skb);
E
Eric Dumazet 已提交
2248
	csum = skb_checksum(skb, offset, skb->len - offset, 0);
2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260
	offset += skb->csum_offset;
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
	skb->ip_summed = CHECKSUM_NONE;

	/* Fragment the skb. IP headers of the fragments are updated in
	 * inet_gso_segment()
	 */
	segs = skb_segment(skb, features);
out:
	return segs;
}