udp.c 64.3 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

80 81
#define pr_fmt(fmt) "UDP: " fmt

L
Linus Torvalds 已提交
82 83
#include <asm/uaccess.h>
#include <asm/ioctls.h>
H
Hideo Aoki 已提交
84
#include <linux/bootmem.h>
85 86
#include <linux/highmem.h>
#include <linux/swap.h>
L
Linus Torvalds 已提交
87 88 89 90 91
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/sockios.h>
92
#include <linux/igmp.h>
L
Linus Torvalds 已提交
93 94 95 96 97 98
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
99
#include <linux/slab.h>
100
#include <net/tcp_states.h>
L
Linus Torvalds 已提交
101 102 103
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
104
#include <net/net_namespace.h>
L
Linus Torvalds 已提交
105
#include <net/icmp.h>
S
Shawn Bohrer 已提交
106
#include <net/inet_hashtables.h>
L
Linus Torvalds 已提交
107 108 109
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
110
#include <trace/events/udp.h>
111
#include <linux/static_key.h>
112
#include <trace/events/skb.h>
113
#include <net/busy_poll.h>
114
#include "udp_impl.h"
L
Linus Torvalds 已提交
115

116
struct udp_table udp_table __read_mostly;
117
EXPORT_SYMBOL(udp_table);
L
Linus Torvalds 已提交
118

E
Eric Dumazet 已提交
119
long sysctl_udp_mem[3] __read_mostly;
H
Hideo Aoki 已提交
120
EXPORT_SYMBOL(sysctl_udp_mem);
E
Eric Dumazet 已提交
121 122

int sysctl_udp_rmem_min __read_mostly;
H
Hideo Aoki 已提交
123
EXPORT_SYMBOL(sysctl_udp_rmem_min);
E
Eric Dumazet 已提交
124 125

int sysctl_udp_wmem_min __read_mostly;
H
Hideo Aoki 已提交
126 127
EXPORT_SYMBOL(sysctl_udp_wmem_min);

E
Eric Dumazet 已提交
128
atomic_long_t udp_memory_allocated;
H
Hideo Aoki 已提交
129 130
EXPORT_SYMBOL(udp_memory_allocated);

131 132
#define MAX_UDP_PORTS 65536
#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
133

134
static int udp_lib_lport_inuse(struct net *net, __u16 num,
135
			       const struct udp_hslot *hslot,
136
			       unsigned long *bitmap,
137 138
			       struct sock *sk,
			       int (*saddr_comp)(const struct sock *sk1,
139 140
						 const struct sock *sk2),
			       unsigned int log)
L
Linus Torvalds 已提交
141
{
142
	struct sock *sk2;
143
	struct hlist_nulls_node *node;
144
	kuid_t uid = sock_i_uid(sk);
145

146
	sk_nulls_for_each(sk2, node, &hslot->head)
147 148
		if (net_eq(sock_net(sk2), net) &&
		    sk2 != sk &&
149
		    (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
150 151 152
		    (!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) &&
153 154
		    (!sk2->sk_reuseport || !sk->sk_reuseport ||
		      !uid_eq(uid, sock_i_uid(sk2))) &&
155 156
		    (*saddr_comp)(sk, sk2)) {
			if (bitmap)
157 158
				__set_bit(udp_sk(sk2)->udp_port_hash >> log,
					  bitmap);
159 160 161
			else
				return 1;
		}
162 163 164
	return 0;
}

E
Eric Dumazet 已提交
165 166 167 168 169 170 171 172 173 174 175 176
/*
 * 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;
177
	kuid_t uid = sock_i_uid(sk);
E
Eric Dumazet 已提交
178 179 180 181
	int res = 0;

	spin_lock(&hslot2->lock);
	udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
182 183 184 185 186 187
		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) &&
188 189
		    (!sk2->sk_reuseport || !sk->sk_reuseport ||
		      !uid_eq(uid, sock_i_uid(sk2))) &&
E
Eric Dumazet 已提交
190 191 192 193 194 195 196 197
		    (*saddr_comp)(sk, sk2)) {
			res = 1;
			break;
		}
	spin_unlock(&hslot2->lock);
	return res;
}

198
/**
199
 *  udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
200 201 202
 *
 *  @sk:          socket struct in question
 *  @snum:        port number to look up
203
 *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
L
Lucas De Marchi 已提交
204
 *  @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
E
Eric Dumazet 已提交
205
 *                   with NULL address
206
 */
207
int udp_lib_get_port(struct sock *sk, unsigned short snum,
208
		       int (*saddr_comp)(const struct sock *sk1,
E
Eric Dumazet 已提交
209 210
					 const struct sock *sk2),
		     unsigned int hash2_nulladdr)
211
{
212
	struct udp_hslot *hslot, *hslot2;
213
	struct udp_table *udptable = sk->sk_prot->h.udp_table;
214
	int    error = 1;
215
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
216

217
	if (!snum) {
E
Eric Dumazet 已提交
218
		int low, high, remaining;
219
		unsigned int rand;
220 221
		unsigned short first, last;
		DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
222

223
		inet_get_local_port_range(net, &low, &high);
224
		remaining = (high - low) + 1;
225

226
		rand = prandom_u32();
227 228 229 230
		first = (((u64)rand * remaining) >> 32) + low;
		/*
		 * force rand to be an odd multiple of UDP_HTABLE_SIZE
		 */
231
		rand = (rand | 1) * (udptable->mask + 1);
E
Eric Dumazet 已提交
232 233
		last = first + udptable->mask + 1;
		do {
234
			hslot = udp_hashslot(udptable, net, first);
235
			bitmap_zero(bitmap, PORTS_PER_CHAIN);
236
			spin_lock_bh(&hslot->lock);
237
			udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
238
					    saddr_comp, udptable->log);
239 240 241 242 243 244 245

			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
246
			do {
247
				if (low <= snum && snum <= high &&
248
				    !test_bit(snum >> udptable->log, bitmap) &&
249
				    !inet_is_local_reserved_port(net, snum))
250 251 252 253
					goto found;
				snum += rand;
			} while (snum != first);
			spin_unlock_bh(&hslot->lock);
E
Eric Dumazet 已提交
254
		} while (++first != last);
255
		goto fail;
256
	} else {
257
		hslot = udp_hashslot(udptable, net, snum);
258
		spin_lock_bh(&hslot->lock);
E
Eric Dumazet 已提交
259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
		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:
283 284
		if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
					saddr_comp, 0))
285 286
			goto fail_unlock;
	}
287
found:
E
Eric Dumazet 已提交
288
	inet_sk(sk)->inet_num = snum;
289 290
	udp_sk(sk)->udp_port_hash = snum;
	udp_sk(sk)->udp_portaddr_hash ^= snum;
L
Linus Torvalds 已提交
291
	if (sk_unhashed(sk)) {
292
		sk_nulls_add_node_rcu(sk, &hslot->head);
E
Eric Dumazet 已提交
293
		hslot->count++;
294
		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
295 296 297 298 299 300 301

		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
302
	}
303
	error = 0;
304 305
fail_unlock:
	spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
306
fail:
307 308
	return error;
}
E
Eric Dumazet 已提交
309
EXPORT_SYMBOL(udp_lib_get_port);
310

311
static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
312 313 314
{
	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);

E
Eric Dumazet 已提交
315
	return 	(!ipv6_only_sock(sk2)  &&
E
Eric Dumazet 已提交
316 317
		 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
		   inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
318 319
}

320 321 322
static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
				       unsigned int port)
{
323
	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
324 325
}

326
int udp_v4_get_port(struct sock *sk, unsigned short snum)
327
{
E
Eric Dumazet 已提交
328
	unsigned int hash2_nulladdr =
329
		udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
E
Eric Dumazet 已提交
330 331 332
	unsigned int hash2_partial =
		udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);

333
	/* precompute partial secondary hash */
E
Eric Dumazet 已提交
334 335
	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
	return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
336 337
}

338 339 340 341 342 343
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;

344
	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
345 346 347
			!ipv6_only_sock(sk)) {
		struct inet_sock *inet = inet_sk(sk);

348
		score = (sk->sk_family == PF_INET ? 2 : 1);
E
Eric Dumazet 已提交
349 350
		if (inet->inet_rcv_saddr) {
			if (inet->inet_rcv_saddr != daddr)
351
				return -1;
352
			score += 4;
353
		}
E
Eric Dumazet 已提交
354 355
		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
356
				return -1;
357
			score += 4;
358
		}
E
Eric Dumazet 已提交
359 360
		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
361
				return -1;
362
			score += 4;
363 364 365 366
		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
367
			score += 4;
368 369 370 371 372
		}
	}
	return score;
}

E
Eric Dumazet 已提交
373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389
/*
 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
 */
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;

390
		score = (sk->sk_family == PF_INET ? 2 : 1);
E
Eric Dumazet 已提交
391 392 393
		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
				return -1;
394
			score += 4;
E
Eric Dumazet 已提交
395 396 397 398
		}
		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
				return -1;
399
			score += 4;
E
Eric Dumazet 已提交
400 401 402 403
		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
404
			score += 4;
E
Eric Dumazet 已提交
405 406 407 408 409
		}
	}
	return score;
}

410 411 412 413
static unsigned int udp_ehashfn(struct net *net, const __be32 laddr,
				 const __u16 lport, const __be32 faddr,
				 const __be16 fport)
{
414 415 416 417
	static u32 udp_ehash_secret __read_mostly;

	net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));

418
	return __inet_ehashfn(laddr, lport, faddr, fport,
419
			      udp_ehash_secret + net_hash_mix(net));
420 421
}

E
Eric Dumazet 已提交
422 423 424 425 426 427 428 429 430

/* 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;
431 432
	int score, badness, matches = 0, reuseport = 0;
	u32 hash = 0;
E
Eric Dumazet 已提交
433 434 435

begin:
	result = NULL;
436
	badness = 0;
E
Eric Dumazet 已提交
437 438 439 440 441 442
	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;
443 444
			reuseport = sk->sk_reuseport;
			if (reuseport) {
445 446
				hash = udp_ehashfn(net, daddr, hnum,
						   saddr, sport);
447 448 449 450 451 452 453
				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
			if (((u64)hash * matches) >> 32 == 0)
				result = sk;
			hash = next_pseudo_random32(hash);
E
Eric Dumazet 已提交
454 455 456 457 458 459 460 461 462 463
		}
	}
	/*
	 * 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) {
E
Eric Dumazet 已提交
464
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
E
Eric Dumazet 已提交
465 466 467 468 469 470 471 472 473 474
			result = NULL;
		else if (unlikely(compute_score2(result, net, saddr, sport,
				  daddr, hnum, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	return result;
}

475 476 477
/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
 * harder than this. -DaveM
 */
478
struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
479
		__be16 sport, __be32 daddr, __be16 dport,
480
		int dif, struct udp_table *udptable)
481
{
482
	struct sock *sk, *result;
483
	struct hlist_nulls_node *node;
484
	unsigned short hnum = ntohs(dport);
E
Eric Dumazet 已提交
485 486
	unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
	struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
487 488
	int score, badness, matches = 0, reuseport = 0;
	u32 hash = 0;
489

490
	rcu_read_lock();
E
Eric Dumazet 已提交
491 492 493 494 495 496 497 498 499 500 501
	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) {
502
			hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
E
Eric Dumazet 已提交
503 504 505 506 507
			slot2 = hash2 & udptable->mask;
			hslot2 = &udptable->hash2[slot2];
			if (hslot->count < hslot2->count)
				goto begin;

508
			result = udp4_lib_lookup2(net, saddr, sport,
509
						  htonl(INADDR_ANY), hnum, dif,
E
Eric Dumazet 已提交
510 511 512 513 514
						  hslot2, slot2);
		}
		rcu_read_unlock();
		return result;
	}
515 516
begin:
	result = NULL;
517
	badness = 0;
518
	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
519 520 521 522 523
		score = compute_score(sk, net, saddr, hnum, sport,
				      daddr, dport, dif);
		if (score > badness) {
			result = sk;
			badness = score;
524 525
			reuseport = sk->sk_reuseport;
			if (reuseport) {
526 527
				hash = udp_ehashfn(net, daddr, hnum,
						   saddr, sport);
528 529 530 531 532 533 534
				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
			if (((u64)hash * matches) >> 32 == 0)
				result = sk;
			hash = next_pseudo_random32(hash);
535 536
		}
	}
537 538 539 540 541
	/*
	 * 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
542
	if (get_nulls_value(node) != slot)
543 544
		goto begin;

545
	if (result) {
E
Eric Dumazet 已提交
546
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
547 548 549 550 551 552 553 554
			result = NULL;
		else if (unlikely(compute_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
555 556
	return result;
}
557
EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
558

559 560
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
						 __be16 sport, __be16 dport,
561
						 struct udp_table *udptable)
562 563 564
{
	const struct iphdr *iph = ip_hdr(skb);

565 566 567
	return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
				 iph->daddr, dport, inet_iif(skb),
				 udptable);
568 569
}

570 571 572
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
573
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
574 575 576
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

S
Shawn Bohrer 已提交
577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596
static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
				       __be16 loc_port, __be32 loc_addr,
				       __be16 rmt_port, __be32 rmt_addr,
				       int dif, unsigned short hnum)
{
	struct inet_sock *inet = inet_sk(sk);

	if (!net_eq(sock_net(sk), net) ||
	    udp_sk(sk)->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(sk) ||
	    (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
		return false;
	if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
		return false;
	return true;
}

597
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
598 599 600 601
					     __be16 loc_port, __be32 loc_addr,
					     __be16 rmt_port, __be32 rmt_addr,
					     int dif)
{
602
	struct hlist_nulls_node *node;
603 604 605
	struct sock *s = sk;
	unsigned short hnum = ntohs(loc_port);

606
	sk_nulls_for_each_from(s, node) {
S
Shawn Bohrer 已提交
607 608 609 610 611
		if (__udp_is_mcast_sock(net, s,
					loc_port, loc_addr,
					rmt_port, rmt_addr,
					dif, hnum))
			goto found;
612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628
	}
	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.
 */

629
void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
630 631
{
	struct inet_sock *inet;
632
	const struct iphdr *iph = (const struct iphdr *)skb->data;
E
Eric Dumazet 已提交
633
	struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
634 635 636 637 638
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	int harderr;
	int err;
639
	struct net *net = dev_net(skb->dev);
640

641
	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
642 643
			iph->saddr, uh->source, skb->dev->ifindex, udptable);
	if (sk == NULL) {
644
		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664
		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 */
665
			ipv4_sk_update_pmtu(skb, sk, info);
666 667 668 669 670 671 672 673 674 675 676 677 678
			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;
679 680
	case ICMP_REDIRECT:
		ipv4_sk_redirect(skb, sk);
681
		goto out;
682 683 684 685 686 687 688 689 690
	}

	/*
	 *      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;
691
	} else
E
Eric Dumazet 已提交
692
		ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
693

694 695 696 697 698 699 700 701
	sk->sk_err = err;
	sk->sk_error_report(sk);
out:
	sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
702
	__udp4_lib_err(skb, info, &udp_table);
703 704 705 706 707
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
708
void udp_flush_pending_frames(struct sock *sk)
709 710 711 712 713 714 715 716 717
{
	struct udp_sock *up = udp_sk(sk);

	if (up->pending) {
		up->len = 0;
		up->pending = 0;
		ip_flush_pending_frames(sk);
	}
}
718
EXPORT_SYMBOL(udp_flush_pending_frames);
719 720

/**
H
Herbert Xu 已提交
721
 * 	udp4_hwcsum  -  handle outgoing HW checksumming
722 723
 * 	@skb: 	sk_buff containing the filled-in UDP header
 * 	        (checksum field must be zeroed out)
H
Herbert Xu 已提交
724 725
 *	@src:	source IP address
 *	@dst:	destination IP address
726
 */
727
void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
728 729
{
	struct udphdr *uh = udp_hdr(skb);
H
Herbert Xu 已提交
730 731 732 733
	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
	int hlen = len;
734 735
	__wsum csum = 0;

H
Herbert Xu 已提交
736
	if (!frags) {
737 738 739 740 741
		/*
		 * 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
742 743
		uh->check = ~csum_tcpudp_magic(src, dst, len,
					       IPPROTO_UDP, 0);
744 745 746 747 748 749
	} 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
750 751 752 753
		do {
			csum = csum_add(csum, frags->csum);
			hlen -= frags->len;
		} while ((frags = frags->next));
754

H
Herbert Xu 已提交
755
		csum = skb_checksum(skb, offset, hlen, csum);
756 757 758 759 760 761 762
		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;
	}
}
763
EXPORT_SYMBOL_GPL(udp4_hwcsum);
764

765
static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
766
{
H
Herbert Xu 已提交
767
	struct sock *sk = skb->sk;
768 769 770 771
	struct inet_sock *inet = inet_sk(sk);
	struct udphdr *uh;
	int err = 0;
	int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
772 773
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
774 775 776 777 778 779
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
780
	uh->source = inet->inet_sport;
781
	uh->dest = fl4->fl4_dport;
H
Herbert Xu 已提交
782
	uh->len = htons(len);
783 784 785
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
786
		csum = udplite_csum(skb);
787

788
	else if (sk->sk_no_check_tx) {   /* UDP csum disabled */
789 790 791 792 793 794

		skb->ip_summed = CHECKSUM_NONE;
		goto send;

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

795
		udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
796 797
		goto send;

H
Herbert Xu 已提交
798 799
	} else
		csum = udp_csum(skb);
800 801

	/* add protocol-dependent pseudo-header */
802
	uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
E
Eric Dumazet 已提交
803
				      sk->sk_protocol, csum);
804 805 806 807
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
E
Eric Dumazet 已提交
808
	err = ip_send_skb(sock_net(sk), skb);
E
Eric Dumazet 已提交
809 810 811 812 813 814 815 816 817
	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
818 819 820 821 822 823
	return err;
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
824
int udp_push_pending_frames(struct sock *sk)
H
Herbert Xu 已提交
825 826 827
{
	struct udp_sock  *up = udp_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
D
David S. Miller 已提交
828
	struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
H
Herbert Xu 已提交
829 830 831
	struct sk_buff *skb;
	int err = 0;

832
	skb = ip_finish_skb(sk, fl4);
H
Herbert Xu 已提交
833 834 835
	if (!skb)
		goto out;

836
	err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
837

838 839 840 841 842
out:
	up->len = 0;
	up->pending = 0;
	return err;
}
843
EXPORT_SYMBOL(udp_push_pending_frames);
844 845 846 847 848 849

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);
850
	struct flowi4 fl4_stack;
D
David S. Miller 已提交
851
	struct flowi4 *fl4;
852 853 854 855 856 857 858 859 860 861 862
	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 *);
H
Herbert Xu 已提交
863
	struct sk_buff *skb;
864
	struct ip_options_data opt_copy;
865 866 867 868 869 870 871 872

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
873
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
874 875 876
		return -EOPNOTSUPP;

	ipc.opt = NULL;
877
	ipc.tx_flags = 0;
878 879
	ipc.ttl = 0;
	ipc.tos = -1;
880

H
Herbert Xu 已提交
881 882
	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;

883
	fl4 = &inet->cork.fl.u.ip4;
884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
	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) {
905
		DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
906 907 908 909 910 911 912 913 914 915 916 917 918 919
		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
920 921
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
922 923 924 925 926
		/* 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
927
	ipc.addr = inet->inet_saddr;
928 929

	ipc.oif = sk->sk_bound_dev_if;
930 931 932

	sock_tx_timestamp(sk, &ipc.tx_flags);

933
	if (msg->msg_controllen) {
934 935
		err = ip_cmsg_send(sock_net(sk), msg, &ipc,
				   sk->sk_family == AF_INET6);
936 937 938 939 940 941
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
942 943 944 945 946 947 948 949 950 951 952 953
	if (!ipc.opt) {
		struct ip_options_rcu *inet_opt;

		rcu_read_lock();
		inet_opt = rcu_dereference(inet->inet_opt);
		if (inet_opt) {
			memcpy(&opt_copy, inet_opt,
			       sizeof(*inet_opt) + inet_opt->opt.optlen);
			ipc.opt = &opt_copy.opt;
		}
		rcu_read_unlock();
	}
954 955 956 957

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

958
	if (ipc.opt && ipc.opt->opt.srr) {
959 960
		if (!daddr)
			return -EINVAL;
961
		faddr = ipc.opt->opt.faddr;
962 963
		connected = 0;
	}
964
	tos = get_rttos(&ipc, inet);
965 966
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
967
	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
968 969 970 971 972 973 974 975 976 977
		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;
978 979
	} else if (!ipc.oif)
		ipc.oif = inet->uc_index;
980 981

	if (connected)
E
Eric Dumazet 已提交
982
		rt = (struct rtable *)sk_dst_check(sk, 0);
983 984

	if (rt == NULL) {
985 986
		struct net *net = sock_net(sk);

987 988
		fl4 = &fl4_stack;
		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
989
				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
990
				   inet_sk_flowi_flags(sk),
991 992
				   faddr, saddr, dport, inet->inet_sport);

993 994
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		rt = ip_route_output_flow(net, fl4, sk);
995 996
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
997
			rt = NULL;
998
			if (err == -ENETUNREACH)
999
				IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1000 1001 1002 1003 1004 1005 1006 1007
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
1008
			sk_dst_set(sk, dst_clone(&rt->dst));
1009 1010 1011 1012 1013 1014
	}

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

1015
	saddr = fl4->saddr;
1016
	if (!ipc.addr)
1017
		daddr = ipc.addr = fl4->daddr;
1018

H
Herbert Xu 已提交
1019 1020
	/* Lockless fast path for the non-corking case. */
	if (!corkreq) {
1021
		skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
H
Herbert Xu 已提交
1022 1023 1024
				  sizeof(struct udphdr), &ipc, &rt,
				  msg->msg_flags);
		err = PTR_ERR(skb);
1025
		if (!IS_ERR_OR_NULL(skb))
1026
			err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
1027 1028 1029
		goto out;
	}

1030 1031 1032 1033 1034 1035
	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);

1036
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1037 1038 1039 1040 1041 1042
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
D
David S. Miller 已提交
1043 1044 1045
	fl4 = &inet->cork.fl.u.ip4;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
1046 1047
	fl4->fl4_dport = dport;
	fl4->fl4_sport = inet->inet_sport;
1048 1049 1050 1051
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
1052 1053 1054
	err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen,
			     sizeof(struct udphdr), &ipc, &rt,
			     corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
	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)) {
1077 1078
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
1079 1080 1081 1082
	}
	return err;

do_confirm:
1083
	dst_confirm(&rt->dst);
1084 1085 1086 1087 1088
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1089
EXPORT_SYMBOL(udp_sendmsg);
1090 1091 1092 1093

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
1094
	struct inet_sock *inet = inet_sk(sk);
1095 1096 1097
	struct udp_sock *up = udp_sk(sk);
	int ret;

1098 1099 1100
	if (flags & MSG_SENDPAGE_NOTLAST)
		flags |= MSG_MORE;

1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
	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);

1118
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1119 1120 1121
		return -EINVAL;
	}

1122 1123
	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
			     page, offset, size, flags);
1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
	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
1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162

/**
 *	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)) {
1163 1164
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1165 1166
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1167
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1168 1169 1170 1171 1172 1173 1174
		__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)) {
1175 1176
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1177 1178
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1179
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1180 1181 1182 1183
	}
	return res;
}

L
Linus Torvalds 已提交
1184 1185 1186
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1187

L
Linus Torvalds 已提交
1188 1189
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1190 1191
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1192
	{
1193 1194
		int amount = sk_wmem_alloc_get(sk);

1195 1196
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1197

1198 1199
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1200
		unsigned int amount = first_packet_length(sk);
1201

E
Eric Dumazet 已提交
1202
		if (amount)
1203 1204 1205 1206 1207
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1208 1209
			amount -= sizeof(struct udphdr);

1210 1211
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1212

1213 1214
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1215
	}
1216 1217

	return 0;
L
Linus Torvalds 已提交
1218
}
E
Eric Dumazet 已提交
1219
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1220

1221 1222 1223 1224 1225 1226 1227 1228 1229
/*
 * 	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);
1230
	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1231
	struct sk_buff *skb;
1232
	unsigned int ulen, copied;
1233
	int peeked, off = 0;
1234 1235
	int err;
	int is_udplite = IS_UDPLITE(sk);
1236
	bool slow;
1237 1238

	if (flags & MSG_ERRQUEUE)
1239
		return ip_recv_error(sk, msg, len, addr_len);
1240 1241 1242

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1243
				  &peeked, &off, &err);
1244 1245 1246 1247
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
1248 1249 1250 1251
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
1252 1253 1254 1255 1256 1257 1258 1259
		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.
	 */

1260
	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1261 1262 1263 1264 1265 1266
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1267
					      msg->msg_iov, copied);
1268
	else {
E
Eric Dumazet 已提交
1269 1270 1271
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1272 1273 1274 1275 1276

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

1277 1278
	if (unlikely(err)) {
		trace_kfree_skb(skb, udp_recvmsg);
1279 1280 1281 1282 1283
		if (!peeked) {
			atomic_inc(&sk->sk_drops);
			UDP_INC_STATS_USER(sock_net(sk),
					   UDP_MIB_INERRORS, is_udplite);
		}
1284
		goto out_free;
1285
	}
1286 1287

	if (!peeked)
1288 1289
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1290

1291
	sock_recv_ts_and_drops(msg, sk, skb);
1292 1293

	/* Copy the address. */
E
Eric Dumazet 已提交
1294
	if (sin) {
1295 1296 1297 1298
		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));
1299
		*addr_len = sizeof(*sin);
1300 1301 1302 1303
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);

1304
	err = copied;
1305 1306 1307 1308
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1309
	skb_free_datagram_locked(sk, skb);
1310 1311 1312 1313
out:
	return err;

csum_copy_err:
1314
	slow = lock_sock_fast(sk);
1315 1316
	if (!skb_kill_datagram(sk, skb, flags)) {
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1317
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1318
	}
1319
	unlock_sock_fast(sk, slow);
1320 1321 1322

	if (noblock)
		return -EAGAIN;
1323 1324 1325

	/* starting over for a new packet */
	msg->msg_flags &= ~MSG_TRUNC;
1326 1327 1328 1329
	goto try_again;
}


L
Linus Torvalds 已提交
1330 1331 1332 1333 1334 1335
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1336

L
Linus Torvalds 已提交
1337
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1338 1339
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1340
	sock_rps_reset_rxhash(sk);
L
Linus Torvalds 已提交
1341 1342 1343 1344 1345 1346
	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
1347
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1348 1349 1350 1351
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1352
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1353

1354 1355
void udp_lib_unhash(struct sock *sk)
{
1356 1357
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1358 1359 1360 1361 1362
		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);
1363

1364 1365
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1366
			hslot->count--;
E
Eric Dumazet 已提交
1367
			inet_sk(sk)->inet_num = 0;
1368
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1369 1370 1371 1372 1373

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1374 1375
		}
		spin_unlock_bh(&hslot->lock);
1376 1377 1378 1379
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
1380 1381 1382 1383 1384 1385 1386 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
/*
 * 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
1423 1424
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1425
	int rc;
E
Eric Dumazet 已提交
1426

1427
	if (inet_sk(sk)->inet_daddr) {
1428
		sock_rps_save_rxhash(sk, skb);
1429 1430
		sk_mark_napi_id(sk, skb);
	}
T
Tom Herbert 已提交
1431

1432
	rc = sock_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1433 1434
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1435 1436

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1437
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1438 1439
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1440 1441
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
1442
		trace_udp_fail_queue_rcv_skb(rc, sk);
E
Eric Dumazet 已提交
1443
		return -1;
H
Herbert Xu 已提交
1444 1445 1446 1447 1448 1449
	}

	return 0;

}

1450 1451 1452 1453 1454 1455 1456 1457
static struct static_key udp_encap_needed __read_mostly;
void udp_encap_enable(void)
{
	if (!static_key_enabled(&udp_encap_needed))
		static_key_slow_inc(&udp_encap_needed);
}
EXPORT_SYMBOL(udp_encap_enable);

1458 1459 1460 1461 1462 1463 1464 1465
/* 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
1466
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
{
	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);

1479
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
1480 1481
		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);

1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493
		/*
		 * 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 */
1494 1495
		encap_rcv = ACCESS_ONCE(up->encap_rcv);
		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1496 1497
			int ret;

1498 1499 1500 1501
			/* Verify checksum before giving to encap */
			if (udp_lib_checksum_complete(skb))
				goto csum_error;

1502
			ret = encap_rcv(sk, skb);
1503
			if (ret <= 0) {
1504 1505
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530
						 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  */
1531 1532
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
				       UDP_SKB_CB(skb)->cscov, skb->len);
1533 1534 1535 1536 1537 1538 1539 1540 1541
			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) {
1542 1543
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
1544 1545 1546 1547
			goto drop;
		}
	}

1548 1549
	if (rcu_access_pointer(sk->sk_filter) &&
	    udp_lib_checksum_complete(skb))
1550
		goto csum_error;
1551

1552

1553
	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1554 1555
		goto drop;

H
Herbert Xu 已提交
1556
	rc = 0;
1557

1558
	ipv4_pktinfo_prepare(sk, skb);
H
Herbert Xu 已提交
1559 1560 1561
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
1562
	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
Z
Zhu Yi 已提交
1563 1564 1565
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1566 1567 1568
	bh_unlock_sock(sk);

	return rc;
1569

1570 1571
csum_error:
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1572
drop:
1573
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1574
	atomic_inc(&sk->sk_drops);
1575 1576 1577 1578
	kfree_skb(skb);
	return -1;
}

1579 1580 1581 1582 1583 1584

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;
1585
	struct sock *sk;
1586 1587

	for (i = 0; i < count; i++) {
1588
		sk = stack[i];
1589 1590 1591
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1592 1593 1594 1595 1596 1597 1598 1599 1600
		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)
1601 1602 1603 1604 1605 1606
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1607
/* For TCP sockets, sk_rx_dst is protected by socket lock
1608
 * For UDP, we use xchg() to guard against concurrent changes.
1609 1610
 */
static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
S
Shawn Bohrer 已提交
1611
{
1612 1613
	struct dst_entry *old;

1614 1615 1616
	dst_hold(dst);
	old = xchg(&sk->sk_rx_dst, dst);
	dst_release(old);
S
Shawn Bohrer 已提交
1617 1618
}

1619 1620 1621
/*
 *	Multicasts and broadcasts go to each listener.
 *
1622
 *	Note: called only from the BH handler context.
1623
 */
1624
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1625 1626
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1627
				    struct udp_table *udptable)
1628
{
1629
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1630
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1631
	int dif;
1632
	unsigned int i, count = 0;
1633

1634
	spin_lock(&hslot->lock);
1635
	sk = sk_nulls_head(&hslot->head);
1636
	dif = skb->dev->ifindex;
1637
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654
	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]);

1655
	spin_unlock(&hslot->lock);
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667

	/*
	 * 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);
	}
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689
	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)
{
	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;
	}

1690 1691
	return skb_checksum_init_zero_check(skb, proto, uh->check,
					    inet_compute_pseudo);
1692 1693 1694 1695 1696 1697
}

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

1698
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1699 1700 1701
		   int proto)
{
	struct sock *sk;
1702
	struct udphdr *uh;
1703
	unsigned short ulen;
E
Eric Dumazet 已提交
1704
	struct rtable *rt = skb_rtable(skb);
1705
	__be32 saddr, daddr;
1706
	struct net *net = dev_net(skb->dev);
1707 1708 1709 1710 1711 1712 1713

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

1714
	uh   = udp_hdr(skb);
1715
	ulen = ntohs(uh->len);
1716 1717 1718
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731
	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;

1732 1733
	sk = skb_steal_sock(skb);
	if (sk) {
1734
		struct dst_entry *dst = skb_dst(skb);
S
Shawn Bohrer 已提交
1735 1736
		int ret;

1737 1738
		if (unlikely(sk->sk_rx_dst != dst))
			udp_sk_rx_dst_set(sk, dst);
1739

S
Shawn Bohrer 已提交
1740
		ret = udp_queue_rcv_skb(sk, skb);
1741
		sock_put(sk);
S
Shawn Bohrer 已提交
1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
		/* 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;
	} else {
		if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
			return __udp4_lib_mcast_deliver(net, skb, uh,
					saddr, daddr, udptable);

		sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
	}
1755 1756

	if (sk != NULL) {
1757 1758 1759
		int ret;

		ret = udp_queue_rcv_skb(sk, skb);
1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777
		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;

1778
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788
	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:
1789
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1790 1791 1792 1793
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source),
		       ulen, skb->len,
		       &daddr, ntohs(uh->dest));
1794 1795 1796 1797 1798 1799 1800
	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).
	 */
1801
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1802 1803
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1804
		       ulen);
1805
	UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1806
drop:
1807
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1808 1809 1810 1811
	kfree_skb(skb);
	return 0;
}

S
Shawn Bohrer 已提交
1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850
/* We can only early demux multicast if there is a single matching socket.
 * If more than one socket found returns NULL
 */
static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
						  __be16 loc_port, __be32 loc_addr,
						  __be16 rmt_port, __be32 rmt_addr,
						  int dif)
{
	struct sock *sk, *result;
	struct hlist_nulls_node *node;
	unsigned short hnum = ntohs(loc_port);
	unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask);
	struct udp_hslot *hslot = &udp_table.hash[slot];

	rcu_read_lock();
begin:
	count = 0;
	result = NULL;
	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
		if (__udp_is_mcast_sock(net, sk,
					loc_port, loc_addr,
					rmt_port, rmt_addr,
					dif, hnum)) {
			result = sk;
			++count;
		}
	}
	/*
	 * 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) != slot)
		goto begin;

	if (result) {
		if (count != 1 ||
		    unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
			result = NULL;
1851
		else if (unlikely(!__udp_is_mcast_sock(net, result,
S
Shawn Bohrer 已提交
1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
						       loc_port, loc_addr,
						       rmt_port, rmt_addr,
						       dif, hnum))) {
			sock_put(result);
			result = NULL;
		}
	}
	rcu_read_unlock();
	return result;
}

/* For unicast we should only early demux connected sockets or we can
 * break forwarding setups.  The chains here can be long so only check
 * if the first socket is an exact match and if not move on.
 */
static struct sock *__udp4_lib_demux_lookup(struct net *net,
					    __be16 loc_port, __be32 loc_addr,
					    __be16 rmt_port, __be32 rmt_addr,
					    int dif)
{
	struct sock *sk, *result;
	struct hlist_nulls_node *node;
	unsigned short hnum = ntohs(loc_port);
	unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
	unsigned int slot2 = hash2 & udp_table.mask;
	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
1878
	INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
S
Shawn Bohrer 已提交
1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);

	rcu_read_lock();
	result = NULL;
	udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
		if (INET_MATCH(sk, net, acookie,
			       rmt_addr, loc_addr, ports, dif))
			result = sk;
		/* Only check first socket in chain */
		break;
	}

	if (result) {
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
			result = NULL;
		else if (unlikely(!INET_MATCH(sk, net, acookie,
					      rmt_addr, loc_addr,
					      ports, dif))) {
			sock_put(result);
			result = NULL;
		}
	}
	rcu_read_unlock();
	return result;
}

void udp_v4_early_demux(struct sk_buff *skb)
{
1907 1908 1909
	struct net *net = dev_net(skb->dev);
	const struct iphdr *iph;
	const struct udphdr *uh;
S
Shawn Bohrer 已提交
1910 1911 1912 1913 1914 1915 1916 1917
	struct sock *sk;
	struct dst_entry *dst;
	int dif = skb->dev->ifindex;

	/* validate the packet */
	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
		return;

1918 1919 1920
	iph = ip_hdr(skb);
	uh = udp_hdr(skb);

S
Shawn Bohrer 已提交
1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943
	if (skb->pkt_type == PACKET_BROADCAST ||
	    skb->pkt_type == PACKET_MULTICAST)
		sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
						   uh->source, iph->saddr, dif);
	else if (skb->pkt_type == PACKET_HOST)
		sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
					     uh->source, iph->saddr, dif);
	else
		return;

	if (!sk)
		return;

	skb->sk = sk;
	skb->destructor = sock_edemux;
	dst = sk->sk_rx_dst;

	if (dst)
		dst = dst_check(dst, 0);
	if (dst)
		skb_dst_set_noref(skb, dst);
}

1944 1945
int udp_rcv(struct sk_buff *skb)
{
1946
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1947 1948
}

1949
void udp_destroy_sock(struct sock *sk)
1950
{
T
Tom Parkin 已提交
1951
	struct udp_sock *up = udp_sk(sk);
1952
	bool slow = lock_sock_fast(sk);
1953
	udp_flush_pending_frames(sk);
1954
	unlock_sock_fast(sk, slow);
T
Tom Parkin 已提交
1955 1956 1957 1958 1959 1960
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
		void (*encap_destroy)(struct sock *sk);
		encap_destroy = ACCESS_ONCE(up->encap_destroy);
		if (encap_destroy)
			encap_destroy(sk);
	}
1961 1962
}

L
Linus Torvalds 已提交
1963 1964 1965
/*
 *	Socket option code for UDP
 */
1966
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1967
		       char __user *optval, unsigned int optlen,
1968
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1969 1970 1971 1972
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1973
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1974

E
Eric Dumazet 已提交
1975
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1976 1977 1978 1979 1980
		return -EINVAL;

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

1981
	switch (optname) {
L
Linus Torvalds 已提交
1982 1983 1984 1985 1986 1987
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1988
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1989 1990 1991
			release_sock(sk);
		}
		break;
1992

L
Linus Torvalds 已提交
1993 1994 1995 1996 1997
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1998 1999
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
2000
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
2001
			up->encap_type = val;
2002
			udp_encap_enable();
L
Linus Torvalds 已提交
2003 2004 2005 2006 2007 2008 2009
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

2010 2011 2012 2013 2014 2015
	/*
	 * 	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
2016
		if (!is_udplite)         /* Disable the option on UDP sockets */
2017 2018 2019
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
2020 2021
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
2022 2023 2024 2025
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

2026 2027
	/* 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
2028 2029
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
2030
		if (!is_udplite)         /* Disable the option on UDP sockets */
2031 2032 2033
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
2034 2035
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
2036 2037 2038 2039
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
2040 2041 2042
	default:
		err = -ENOPROTOOPT;
		break;
2043
	}
L
Linus Torvalds 已提交
2044 2045 2046

	return err;
}
E
Eric Dumazet 已提交
2047
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
2048

2049
int udp_setsockopt(struct sock *sk, int level, int optname,
2050
		   char __user *optval, unsigned int optlen)
2051 2052 2053 2054 2055 2056 2057 2058 2059
{
	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,
2060
			  char __user *optval, unsigned int optlen)
2061 2062 2063 2064 2065 2066 2067 2068
{
	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

2069 2070
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
2071 2072 2073 2074
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
2075
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
2076 2077 2078
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
2079

2080
	if (len < 0)
L
Linus Torvalds 已提交
2081 2082
		return -EINVAL;

2083
	switch (optname) {
L
Linus Torvalds 已提交
2084 2085 2086 2087 2088 2089 2090 2091
	case UDP_CORK:
		val = up->corkflag;
		break;

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

2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
	/* 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
2102 2103
	default:
		return -ENOPROTOOPT;
2104
	}
L
Linus Torvalds 已提交
2105

2106
	if (put_user(len, optlen))
2107
		return -EFAULT;
E
Eric Dumazet 已提交
2108
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
2109
		return -EFAULT;
2110
	return 0;
L
Linus Torvalds 已提交
2111
}
E
Eric Dumazet 已提交
2112
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
2113

2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130
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
2131 2132 2133 2134 2135 2136
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
2137
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
2138 2139 2140 2141 2142 2143 2144 2145 2146 2147
 *	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;
2148

2149 2150
	sock_rps_record_flow(sk);

L
Linus Torvalds 已提交
2151
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
2152 2153 2154
	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
2155 2156

	return mask;
2157

L
Linus Torvalds 已提交
2158
}
E
Eric Dumazet 已提交
2159
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
2160

2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173
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
2174
	.backlog_rcv	   = __udp_queue_rcv_skb,
2175
	.release_cb	   = ip4_datagram_release_cb,
2176 2177
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
2178
	.rehash		   = udp_v4_rehash,
2179 2180 2181 2182 2183 2184
	.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),
2185
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
2186
	.h.udp_table	   = &udp_table,
2187 2188 2189 2190
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
2191
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
2192
};
E
Eric Dumazet 已提交
2193
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
2194 2195 2196 2197

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

2198
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
2199 2200 2201
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
2202
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2203

2204 2205
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
2206
		struct hlist_nulls_node *node;
2207
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2208 2209 2210 2211

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

2212
		spin_lock_bh(&hslot->lock);
2213
		sk_nulls_for_each(sk, node, &hslot->head) {
2214
			if (!net_eq(sock_net(sk), net))
2215
				continue;
L
Linus Torvalds 已提交
2216 2217 2218
			if (sk->sk_family == state->family)
				goto found;
		}
2219
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
2220 2221 2222 2223 2224 2225 2226 2227 2228
	}
	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;
2229
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2230 2231

	do {
2232
		sk = sk_nulls_next(sk);
2233
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
2234

2235
	if (!sk) {
2236
		if (state->bucket <= state->udp_table->mask)
2237
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2238
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
2239 2240 2241 2242 2243 2244
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
2245
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
2246 2247

	if (sk)
2248
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
2249 2250 2251 2252 2253 2254
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
2255
	struct udp_iter_state *state = seq->private;
2256
	state->bucket = MAX_UDP_PORTS;
2257

2258
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
2259 2260 2261 2262 2263 2264
}

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

2265
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
2266 2267 2268 2269 2270 2271 2272 2273 2274 2275
		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)
{
2276 2277
	struct udp_iter_state *state = seq->private;

2278
	if (state->bucket <= state->udp_table->mask)
2279
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2280 2281
}

2282
int udp_seq_open(struct inode *inode, struct file *file)
L
Linus Torvalds 已提交
2283
{
A
Al Viro 已提交
2284
	struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2285 2286
	struct udp_iter_state *s;
	int err;
2287

2288 2289 2290 2291
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2292

2293
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2294
	s->family		= afinfo->family;
2295
	s->udp_table		= afinfo->udp_table;
2296
	return err;
2297
}
2298
EXPORT_SYMBOL(udp_seq_open);
2299

L
Linus Torvalds 已提交
2300
/* ------------------------------------------------------------------------ */
2301
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2302 2303 2304 2305
{
	struct proc_dir_entry *p;
	int rc = 0;

2306 2307 2308 2309
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2310
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2311
			     afinfo->seq_fops, afinfo);
2312
	if (!p)
L
Linus Torvalds 已提交
2313 2314 2315
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2316
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2317

2318
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2319
{
2320
	remove_proc_entry(afinfo->name, net->proc_net);
L
Linus Torvalds 已提交
2321
}
E
Eric Dumazet 已提交
2322
EXPORT_SYMBOL(udp_proc_unregister);
2323 2324

/* ------------------------------------------------------------------------ */
2325
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2326
		int bucket)
2327 2328
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2329 2330 2331 2332
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2333

2334
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2335
		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2336
		bucket, src, srcp, dest, destp, sp->sk_state,
2337 2338
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2339 2340 2341
		0, 0L, 0,
		from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
		0, sock_i_ino(sp),
E
Eric Dumazet 已提交
2342
		atomic_read(&sp->sk_refcnt), sp,
2343
		atomic_read(&sp->sk_drops));
2344 2345 2346 2347
}

int udp4_seq_show(struct seq_file *seq, void *v)
{
2348
	seq_setwidth(seq, 127);
2349
	if (v == SEQ_START_TOKEN)
2350
		seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
2351
			   "rx_queue tr tm->when retrnsmt   uid  timeout "
E
Eric Dumazet 已提交
2352
			   "inode ref pointer drops");
2353 2354 2355
	else {
		struct udp_iter_state *state = seq->private;

2356
		udp4_format_sock(v, seq, state->bucket);
2357
	}
2358
	seq_pad(seq, '\n');
2359 2360 2361
	return 0;
}

2362 2363 2364 2365 2366 2367 2368 2369
static const struct file_operations udp_afinfo_seq_fops = {
	.owner    = THIS_MODULE,
	.open     = udp_seq_open,
	.read     = seq_read,
	.llseek   = seq_lseek,
	.release  = seq_release_net
};

2370 2371 2372 2373
/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2374
	.udp_table	= &udp_table,
2375
	.seq_fops	= &udp_afinfo_seq_fops,
2376 2377 2378
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2379 2380
};

2381
static int __net_init udp4_proc_init_net(struct net *net)
2382 2383 2384 2385
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2386
static void __net_exit udp4_proc_exit_net(struct net *net)
2387 2388 2389 2390 2391 2392 2393 2394 2395
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2396 2397
int __init udp4_proc_init(void)
{
2398
	return register_pernet_subsys(&udp4_net_ops);
2399 2400 2401 2402
}

void udp4_proc_exit(void)
{
2403
	unregister_pernet_subsys(&udp4_net_ops);
2404
}
L
Linus Torvalds 已提交
2405 2406
#endif /* CONFIG_PROC_FS */

2407 2408
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2409
{
2410 2411
	ssize_t ret;

2412 2413
	if (!str)
		return 0;
2414 2415 2416 2417 2418

	ret = kstrtoul(str, 0, &uhash_entries);
	if (ret)
		return 0;

2419 2420 2421 2422 2423
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2424

2425 2426 2427 2428
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
	table->hash = alloc_large_system_hash(name,
					      2 * sizeof(struct udp_hslot),
					      uhash_entries,
					      21, /* one slot per 2 MB */
					      0,
					      &table->log,
					      &table->mask,
					      UDP_HTABLE_SIZE_MIN,
					      64 * 1024);

2439
	table->hash2 = table->hash + (table->mask + 1);
2440
	for (i = 0; i <= table->mask; i++) {
2441
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2442
		table->hash[i].count = 0;
2443 2444
		spin_lock_init(&table->hash[i].lock);
	}
2445 2446 2447 2448 2449
	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);
	}
2450 2451
}

H
Hideo Aoki 已提交
2452 2453
void __init udp_init(void)
{
2454
	unsigned long limit;
H
Hideo Aoki 已提交
2455

2456
	udp_table_init(&udp_table, "UDP");
2457
	limit = nr_free_buffer_pages() / 8;
H
Hideo Aoki 已提交
2458 2459 2460 2461 2462 2463 2464 2465 2466
	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;
}

2467 2468
struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
				       netdev_features_t features)
2469 2470
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
2471
	u16 mac_offset = skb->mac_header;
2472 2473
	int mac_len = skb->mac_len;
	int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
P
Pravin B Shelar 已提交
2474
	__be16 protocol = skb->protocol;
2475
	netdev_features_t enc_features;
P
Pravin B Shelar 已提交
2476
	int outer_hlen;
2477 2478 2479 2480 2481 2482 2483 2484 2485

	if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
		goto out;

	skb->encapsulation = 0;
	__skb_pull(skb, tnl_hlen);
	skb_reset_mac_header(skb);
	skb_set_network_header(skb, skb_inner_network_offset(skb));
	skb->mac_len = skb_inner_network_offset(skb);
2486
	skb->protocol = htons(ETH_P_TEB);
2487 2488 2489 2490

	/* segment inner packet. */
	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
	segs = skb_mac_gso_segment(skb, enc_features);
2491 2492 2493
	if (!segs || IS_ERR(segs)) {
		skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
				     mac_len);
2494
		goto out;
2495
	}
2496 2497 2498 2499 2500 2501 2502

	outer_hlen = skb_tnl_header_len(skb);
	skb = segs;
	do {
		struct udphdr *uh;
		int udp_offset = outer_hlen - tnl_hlen;

2503 2504 2505
		skb_reset_inner_headers(skb);
		skb->encapsulation = 1;

2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
		skb->mac_len = mac_len;

		skb_push(skb, outer_hlen);
		skb_reset_mac_header(skb);
		skb_set_network_header(skb, mac_len);
		skb_set_transport_header(skb, udp_offset);
		uh = udp_hdr(skb);
		uh->len = htons(skb->len - udp_offset);

		/* csum segment if tunnel sets skb with csum. */
2516
		if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) {
2517 2518 2519 2520 2521 2522 2523 2524 2525 2526
			struct iphdr *iph = ip_hdr(skb);

			uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
						       skb->len - udp_offset,
						       IPPROTO_UDP, 0);
			uh->check = csum_fold(skb_checksum(skb, udp_offset,
							   skb->len - udp_offset, 0));
			if (uh->check == 0)
				uh->check = CSUM_MANGLED_0;

2527 2528 2529 2530 2531 2532 2533 2534 2535 2536
		} else if (protocol == htons(ETH_P_IPV6)) {
			struct ipv6hdr *ipv6h = ipv6_hdr(skb);
			u32 len = skb->len - udp_offset;

			uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
						     len, IPPROTO_UDP, 0);
			uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0));
			if (uh->check == 0)
				uh->check = CSUM_MANGLED_0;
			skb->ip_summed = CHECKSUM_NONE;
2537
		}
2538

P
Pravin B Shelar 已提交
2539
		skb->protocol = protocol;
2540 2541 2542 2543
	} while ((skb = skb->next));
out:
	return segs;
}