udp.c 63.6 KB
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/*
 * 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).
 *
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 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
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 *		Alan Cox, <alan@lxorguk.ukuu.org.uk>
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 *		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
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 *		Alan Cox	:	Tidied select() semantics.
 *		Alan Cox	:	udp_err() fixed properly, also now
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 *					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
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 *					for connect.
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 *	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
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 *	James Chapman		:	Add L2TP encapsulation type.
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 *
 *
 *		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.
 */
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#define pr_fmt(fmt) "UDP: " fmt

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#include <asm/uaccess.h>
#include <asm/ioctls.h>
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#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/sockios.h>
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#include <linux/igmp.h>
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#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
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#include <linux/slab.h>
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#include <net/tcp_states.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/proc_fs.h>
#include <linux/seq_file.h>
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#include <net/net_namespace.h>
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#include <net/icmp.h>
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#include <net/inet_hashtables.h>
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#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
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#include <trace/events/udp.h>
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#include <linux/static_key.h>
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#include <trace/events/skb.h>
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#include <net/busy_poll.h>
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#include "udp_impl.h"
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struct udp_table udp_table __read_mostly;
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EXPORT_SYMBOL(udp_table);
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long sysctl_udp_mem[3] __read_mostly;
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EXPORT_SYMBOL(sysctl_udp_mem);
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int sysctl_udp_rmem_min __read_mostly;
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EXPORT_SYMBOL(sysctl_udp_rmem_min);
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int sysctl_udp_wmem_min __read_mostly;
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EXPORT_SYMBOL(sysctl_udp_wmem_min);

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atomic_long_t udp_memory_allocated;
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EXPORT_SYMBOL(udp_memory_allocated);

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#define MAX_UDP_PORTS 65536
#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
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static int udp_lib_lport_inuse(struct net *net, __u16 num,
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			       const struct udp_hslot *hslot,
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			       unsigned long *bitmap,
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			       struct sock *sk,
			       int (*saddr_comp)(const struct sock *sk1,
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						 const struct sock *sk2),
			       unsigned int log)
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{
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	struct sock *sk2;
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	struct hlist_nulls_node *node;
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	kuid_t uid = sock_i_uid(sk);
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	sk_nulls_for_each(sk2, node, &hslot->head)
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		if (net_eq(sock_net(sk2), net) &&
		    sk2 != sk &&
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		    (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
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		    (!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) &&
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		    (!sk2->sk_reuseport || !sk->sk_reuseport ||
		      !uid_eq(uid, sock_i_uid(sk2))) &&
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		    (*saddr_comp)(sk, sk2)) {
			if (bitmap)
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				__set_bit(udp_sk(sk2)->udp_port_hash >> log,
					  bitmap);
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			else
				return 1;
		}
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	return 0;
}

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/*
 * 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;
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	kuid_t uid = sock_i_uid(sk);
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	int res = 0;

	spin_lock(&hslot2->lock);
	udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
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		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) &&
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		    (!sk2->sk_reuseport || !sk->sk_reuseport ||
		      !uid_eq(uid, sock_i_uid(sk2))) &&
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		    (*saddr_comp)(sk, sk2)) {
			res = 1;
			break;
		}
	spin_unlock(&hslot2->lock);
	return res;
}

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/**
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 *  udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
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 *
 *  @sk:          socket struct in question
 *  @snum:        port number to look up
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 *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
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 *  @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
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 *                   with NULL address
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 */
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int udp_lib_get_port(struct sock *sk, unsigned short snum,
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		       int (*saddr_comp)(const struct sock *sk1,
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					 const struct sock *sk2),
		     unsigned int hash2_nulladdr)
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{
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	struct udp_hslot *hslot, *hslot2;
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	struct udp_table *udptable = sk->sk_prot->h.udp_table;
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	int    error = 1;
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	struct net *net = sock_net(sk);
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	if (!snum) {
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		int low, high, remaining;
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		unsigned int rand;
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		unsigned short first, last;
		DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
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		inet_get_local_port_range(net, &low, &high);
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		remaining = (high - low) + 1;
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		rand = prandom_u32();
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		first = reciprocal_scale(rand, remaining) + low;
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		/*
		 * force rand to be an odd multiple of UDP_HTABLE_SIZE
		 */
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		rand = (rand | 1) * (udptable->mask + 1);
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		last = first + udptable->mask + 1;
		do {
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			hslot = udp_hashslot(udptable, net, first);
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			bitmap_zero(bitmap, PORTS_PER_CHAIN);
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			spin_lock_bh(&hslot->lock);
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			udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
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					    saddr_comp, udptable->log);
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			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.
			 */
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			do {
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				if (low <= snum && snum <= high &&
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				    !test_bit(snum >> udptable->log, bitmap) &&
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				    !inet_is_local_reserved_port(net, snum))
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					goto found;
				snum += rand;
			} while (snum != first);
			spin_unlock_bh(&hslot->lock);
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		} while (++first != last);
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		goto fail;
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	} else {
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		hslot = udp_hashslot(udptable, net, snum);
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		spin_lock_bh(&hslot->lock);
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		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:
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		if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
					saddr_comp, 0))
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			goto fail_unlock;
	}
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found:
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	inet_sk(sk)->inet_num = snum;
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	udp_sk(sk)->udp_port_hash = snum;
	udp_sk(sk)->udp_portaddr_hash ^= snum;
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	if (sk_unhashed(sk)) {
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		sk_nulls_add_node_rcu(sk, &hslot->head);
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		hslot->count++;
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		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
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		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);
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	}
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	error = 0;
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fail_unlock:
	spin_unlock_bh(&hslot->lock);
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fail:
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	return error;
}
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EXPORT_SYMBOL(udp_lib_get_port);
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static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
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{
	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);

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	return 	(!ipv6_only_sock(sk2)  &&
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		 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
		   inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
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}

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static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
				       unsigned int port)
{
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	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
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}

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int udp_v4_get_port(struct sock *sk, unsigned short snum)
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{
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	unsigned int hash2_nulladdr =
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		udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
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	unsigned int hash2_partial =
		udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);

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	/* precompute partial secondary hash */
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	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
	return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
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}

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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;

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

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		score = (sk->sk_family == PF_INET ? 2 : 1);
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		if (inet->inet_rcv_saddr) {
			if (inet->inet_rcv_saddr != daddr)
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				return -1;
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			score += 4;
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		}
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		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
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				return -1;
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			score += 4;
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		}
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		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
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				return -1;
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			score += 4;
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		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
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			score += 4;
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		}
	}
	return score;
}

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/*
 * 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;

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		score = (sk->sk_family == PF_INET ? 2 : 1);
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		if (inet->inet_daddr) {
			if (inet->inet_daddr != saddr)
				return -1;
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			score += 4;
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		}
		if (inet->inet_dport) {
			if (inet->inet_dport != sport)
				return -1;
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			score += 4;
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		}
		if (sk->sk_bound_dev_if) {
			if (sk->sk_bound_dev_if != dif)
				return -1;
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			score += 4;
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		}
	}
	return score;
}

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static unsigned int udp_ehashfn(struct net *net, const __be32 laddr,
				 const __u16 lport, const __be32 faddr,
				 const __be16 fport)
{
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	static u32 udp_ehash_secret __read_mostly;

	net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));

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	return __inet_ehashfn(laddr, lport, faddr, fport,
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			      udp_ehash_secret + net_hash_mix(net));
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}

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/* 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;
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	int score, badness, matches = 0, reuseport = 0;
	u32 hash = 0;
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begin:
	result = NULL;
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	badness = 0;
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	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;
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			reuseport = sk->sk_reuseport;
			if (reuseport) {
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				hash = udp_ehashfn(net, daddr, hnum,
						   saddr, sport);
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				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
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			if (reciprocal_scale(hash, matches) == 0)
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				result = sk;
			hash = next_pseudo_random32(hash);
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		}
	}
	/*
	 * 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) {
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		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
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			result = NULL;
		else if (unlikely(compute_score2(result, net, saddr, sport,
				  daddr, hnum, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	return result;
}

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/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
 * harder than this. -DaveM
 */
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struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
480
		__be16 sport, __be32 daddr, __be16 dport,
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		int dif, struct udp_table *udptable)
482
{
483
	struct sock *sk, *result;
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	struct hlist_nulls_node *node;
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	unsigned short hnum = ntohs(dport);
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	unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
	struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
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	int score, badness, matches = 0, reuseport = 0;
	u32 hash = 0;
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	rcu_read_lock();
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Eric Dumazet 已提交
492 493 494 495 496 497 498 499 500 501 502
	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) {
503
			hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
E
Eric Dumazet 已提交
504 505 506 507 508
			slot2 = hash2 & udptable->mask;
			hslot2 = &udptable->hash2[slot2];
			if (hslot->count < hslot2->count)
				goto begin;

509
			result = udp4_lib_lookup2(net, saddr, sport,
510
						  htonl(INADDR_ANY), hnum, dif,
E
Eric Dumazet 已提交
511 512 513 514 515
						  hslot2, slot2);
		}
		rcu_read_unlock();
		return result;
	}
516 517
begin:
	result = NULL;
518
	badness = 0;
519
	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
520 521 522 523 524
		score = compute_score(sk, net, saddr, hnum, sport,
				      daddr, dport, dif);
		if (score > badness) {
			result = sk;
			badness = score;
525 526
			reuseport = sk->sk_reuseport;
			if (reuseport) {
527 528
				hash = udp_ehashfn(net, daddr, hnum,
						   saddr, sport);
529 530 531 532
				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
533
			if (reciprocal_scale(hash, matches) == 0)
534 535
				result = sk;
			hash = next_pseudo_random32(hash);
536 537
		}
	}
538 539 540 541 542
	/*
	 * 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
543
	if (get_nulls_value(node) != slot)
544 545
		goto begin;

546
	if (result) {
E
Eric Dumazet 已提交
547
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
548 549 550 551 552 553 554 555
			result = NULL;
		else if (unlikely(compute_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
556 557
	return result;
}
558
EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
559

560 561
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
						 __be16 sport, __be16 dport,
562
						 struct udp_table *udptable)
563 564 565
{
	const struct iphdr *iph = ip_hdr(skb);

566 567 568
	return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
				 iph->daddr, dport, inet_iif(skb),
				 udptable);
569 570
}

571 572 573
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
574
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
575 576 577
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

S
Shawn Bohrer 已提交
578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597
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;
}

598 599 600 601 602 603 604 605 606 607 608
/*
 * 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.
 */

609
void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
610 611
{
	struct inet_sock *inet;
612
	const struct iphdr *iph = (const struct iphdr *)skb->data;
E
Eric Dumazet 已提交
613
	struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
614 615 616 617 618
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	int harderr;
	int err;
619
	struct net *net = dev_net(skb->dev);
620

621
	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
622 623
			iph->saddr, uh->source, skb->dev->ifindex, udptable);
	if (sk == NULL) {
624
		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644
		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 */
645
			ipv4_sk_update_pmtu(skb, sk, info);
646 647 648 649 650 651 652 653 654 655 656 657 658
			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;
659 660
	case ICMP_REDIRECT:
		ipv4_sk_redirect(skb, sk);
661
		goto out;
662 663 664 665 666 667 668 669 670
	}

	/*
	 *      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;
671
	} else
E
Eric Dumazet 已提交
672
		ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
673

674 675 676 677 678 679 680 681
	sk->sk_err = err;
	sk->sk_error_report(sk);
out:
	sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
682
	__udp4_lib_err(skb, info, &udp_table);
683 684 685 686 687
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
688
void udp_flush_pending_frames(struct sock *sk)
689 690 691 692 693 694 695 696 697
{
	struct udp_sock *up = udp_sk(sk);

	if (up->pending) {
		up->len = 0;
		up->pending = 0;
		ip_flush_pending_frames(sk);
	}
}
698
EXPORT_SYMBOL(udp_flush_pending_frames);
699 700

/**
H
Herbert Xu 已提交
701
 * 	udp4_hwcsum  -  handle outgoing HW checksumming
702 703
 * 	@skb: 	sk_buff containing the filled-in UDP header
 * 	        (checksum field must be zeroed out)
H
Herbert Xu 已提交
704 705
 *	@src:	source IP address
 *	@dst:	destination IP address
706
 */
707
void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
708 709
{
	struct udphdr *uh = udp_hdr(skb);
H
Herbert Xu 已提交
710 711 712
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
	int hlen = len;
713 714
	__wsum csum = 0;

715
	if (!skb_has_frag_list(skb)) {
716 717 718 719 720
		/*
		 * 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
721 722
		uh->check = ~csum_tcpudp_magic(src, dst, len,
					       IPPROTO_UDP, 0);
723
	} else {
724 725
		struct sk_buff *frags;

726 727 728 729 730
		/*
		 * 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
		 */
731
		skb_walk_frags(skb, frags) {
H
Herbert Xu 已提交
732 733
			csum = csum_add(csum, frags->csum);
			hlen -= frags->len;
734
		}
735

H
Herbert Xu 已提交
736
		csum = skb_checksum(skb, offset, hlen, csum);
737 738 739 740 741 742 743
		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;
	}
}
744
EXPORT_SYMBOL_GPL(udp4_hwcsum);
745

746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
 * for the simple case like when setting the checksum for a UDP tunnel.
 */
void udp_set_csum(bool nocheck, struct sk_buff *skb,
		  __be32 saddr, __be32 daddr, int len)
{
	struct udphdr *uh = udp_hdr(skb);

	if (nocheck)
		uh->check = 0;
	else if (skb_is_gso(skb))
		uh->check = ~udp_v4_check(len, saddr, daddr, 0);
	else if (skb_dst(skb) && skb_dst(skb)->dev &&
		 (skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) {

		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);

		skb->ip_summed = CHECKSUM_PARTIAL;
		skb->csum_start = skb_transport_header(skb) - skb->head;
		skb->csum_offset = offsetof(struct udphdr, check);
		uh->check = ~udp_v4_check(len, saddr, daddr, 0);
	} else {
		__wsum csum;

		BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);

		uh->check = 0;
		csum = skb_checksum(skb, 0, len, 0);
		uh->check = udp_v4_check(len, saddr, daddr, csum);
		if (uh->check == 0)
			uh->check = CSUM_MANGLED_0;

		skb->ip_summed = CHECKSUM_UNNECESSARY;
	}
}
EXPORT_SYMBOL(udp_set_csum);

783
static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
784
{
H
Herbert Xu 已提交
785
	struct sock *sk = skb->sk;
786 787 788 789
	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
790 791
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
792 793 794 795 796 797
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
798
	uh->source = inet->inet_sport;
799
	uh->dest = fl4->fl4_dport;
H
Herbert Xu 已提交
800
	uh->len = htons(len);
801 802 803
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
804
		csum = udplite_csum(skb);
805

806
	else if (sk->sk_no_check_tx) {   /* UDP csum disabled */
807 808 809 810 811 812

		skb->ip_summed = CHECKSUM_NONE;
		goto send;

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

813
		udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
814 815
		goto send;

H
Herbert Xu 已提交
816 817
	} else
		csum = udp_csum(skb);
818 819

	/* add protocol-dependent pseudo-header */
820
	uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
E
Eric Dumazet 已提交
821
				      sk->sk_protocol, csum);
822 823 824 825
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
E
Eric Dumazet 已提交
826
	err = ip_send_skb(sock_net(sk), skb);
E
Eric Dumazet 已提交
827 828 829 830 831 832 833 834 835
	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
836 837 838 839 840 841
	return err;
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
842
int udp_push_pending_frames(struct sock *sk)
H
Herbert Xu 已提交
843 844 845
{
	struct udp_sock  *up = udp_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
D
David S. Miller 已提交
846
	struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
H
Herbert Xu 已提交
847 848 849
	struct sk_buff *skb;
	int err = 0;

850
	skb = ip_finish_skb(sk, fl4);
H
Herbert Xu 已提交
851 852 853
	if (!skb)
		goto out;

854
	err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
855

856 857 858 859 860
out:
	up->len = 0;
	up->pending = 0;
	return err;
}
861
EXPORT_SYMBOL(udp_push_pending_frames);
862 863 864 865 866 867

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);
868
	struct flowi4 fl4_stack;
D
David S. Miller 已提交
869
	struct flowi4 *fl4;
870 871 872 873 874 875 876 877 878 879 880
	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
881
	struct sk_buff *skb;
882
	struct ip_options_data opt_copy;
883 884 885 886 887 888 889 890

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
891
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
892 893 894
		return -EOPNOTSUPP;

	ipc.opt = NULL;
895
	ipc.tx_flags = 0;
896 897
	ipc.ttl = 0;
	ipc.tos = -1;
898

H
Herbert Xu 已提交
899 900
	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;

901
	fl4 = &inet->cork.fl.u.ip4;
902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
	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) {
923
		DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
924 925 926 927 928 929 930 931 932 933 934 935 936 937
		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
938 939
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
940 941 942 943 944
		/* 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
945
	ipc.addr = inet->inet_saddr;
946 947

	ipc.oif = sk->sk_bound_dev_if;
948 949 950

	sock_tx_timestamp(sk, &ipc.tx_flags);

951
	if (msg->msg_controllen) {
952 953
		err = ip_cmsg_send(sock_net(sk), msg, &ipc,
				   sk->sk_family == AF_INET6);
954 955 956 957 958 959
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
960 961 962 963 964 965 966 967 968 969 970 971
	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();
	}
972 973 974 975

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

976
	if (ipc.opt && ipc.opt->opt.srr) {
977 978
		if (!daddr)
			return -EINVAL;
979
		faddr = ipc.opt->opt.faddr;
980 981
		connected = 0;
	}
982
	tos = get_rttos(&ipc, inet);
983 984
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
985
	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
986 987 988 989 990 991 992 993 994 995
		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;
996 997
	} else if (!ipc.oif)
		ipc.oif = inet->uc_index;
998 999

	if (connected)
E
Eric Dumazet 已提交
1000
		rt = (struct rtable *)sk_dst_check(sk, 0);
1001 1002

	if (rt == NULL) {
1003 1004
		struct net *net = sock_net(sk);

1005 1006
		fl4 = &fl4_stack;
		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1007
				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
1008
				   inet_sk_flowi_flags(sk),
1009 1010
				   faddr, saddr, dport, inet->inet_sport);

1011 1012
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		rt = ip_route_output_flow(net, fl4, sk);
1013 1014
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
1015
			rt = NULL;
1016
			if (err == -ENETUNREACH)
1017
				IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1018 1019 1020 1021 1022 1023 1024 1025
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
1026
			sk_dst_set(sk, dst_clone(&rt->dst));
1027 1028 1029 1030 1031 1032
	}

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

1033
	saddr = fl4->saddr;
1034
	if (!ipc.addr)
1035
		daddr = ipc.addr = fl4->daddr;
1036

H
Herbert Xu 已提交
1037 1038
	/* Lockless fast path for the non-corking case. */
	if (!corkreq) {
1039
		skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
H
Herbert Xu 已提交
1040 1041 1042
				  sizeof(struct udphdr), &ipc, &rt,
				  msg->msg_flags);
		err = PTR_ERR(skb);
1043
		if (!IS_ERR_OR_NULL(skb))
1044
			err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
1045 1046 1047
		goto out;
	}

1048 1049 1050 1051 1052 1053
	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);

1054
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1055 1056 1057 1058 1059 1060
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
D
David S. Miller 已提交
1061 1062 1063
	fl4 = &inet->cork.fl.u.ip4;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
1064 1065
	fl4->fl4_dport = dport;
	fl4->fl4_sport = inet->inet_sport;
1066 1067 1068 1069
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
1070 1071 1072
	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);
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
	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)) {
1095 1096
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
1097 1098 1099 1100
	}
	return err;

do_confirm:
1101
	dst_confirm(&rt->dst);
1102 1103 1104 1105 1106
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1107
EXPORT_SYMBOL(udp_sendmsg);
1108 1109 1110 1111

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
1112
	struct inet_sock *inet = inet_sk(sk);
1113 1114 1115
	struct udp_sock *up = udp_sk(sk);
	int ret;

1116 1117 1118
	if (flags & MSG_SENDPAGE_NOTLAST)
		flags |= MSG_MORE;

1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
	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);

1136
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1137 1138 1139
		return -EINVAL;
	}

1140 1141
	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
			     page, offset, size, flags);
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
	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
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180

/**
 *	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)) {
1181 1182
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1183 1184
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1185
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1186 1187 1188 1189 1190 1191 1192
		__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)) {
1193 1194
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1195 1196
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1197
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1198 1199 1200 1201
	}
	return res;
}

L
Linus Torvalds 已提交
1202 1203 1204
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1205

L
Linus Torvalds 已提交
1206 1207
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1208 1209
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1210
	{
1211 1212
		int amount = sk_wmem_alloc_get(sk);

1213 1214
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1215

1216 1217
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1218
		unsigned int amount = first_packet_length(sk);
1219

E
Eric Dumazet 已提交
1220
		if (amount)
1221 1222 1223 1224 1225
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1226 1227
			amount -= sizeof(struct udphdr);

1228 1229
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1230

1231 1232
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1233
	}
1234 1235

	return 0;
L
Linus Torvalds 已提交
1236
}
E
Eric Dumazet 已提交
1237
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1238

1239 1240 1241 1242 1243 1244 1245 1246 1247
/*
 * 	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);
1248
	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1249
	struct sk_buff *skb;
1250
	unsigned int ulen, copied;
1251
	int peeked, off = 0;
1252 1253
	int err;
	int is_udplite = IS_UDPLITE(sk);
1254
	bool slow;
1255 1256

	if (flags & MSG_ERRQUEUE)
1257
		return ip_recv_error(sk, msg, len, addr_len);
1258 1259 1260

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1261
				  &peeked, &off, &err);
1262 1263 1264 1265
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
1266 1267 1268 1269
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
1270 1271 1272 1273 1274 1275 1276 1277
		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.
	 */

1278
	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1279 1280 1281 1282 1283
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
1284 1285
		err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
					    msg, copied);
1286
	else {
E
Eric Dumazet 已提交
1287 1288 1289
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1290 1291 1292 1293 1294

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

1295 1296
	if (unlikely(err)) {
		trace_kfree_skb(skb, udp_recvmsg);
1297 1298 1299 1300 1301
		if (!peeked) {
			atomic_inc(&sk->sk_drops);
			UDP_INC_STATS_USER(sock_net(sk),
					   UDP_MIB_INERRORS, is_udplite);
		}
1302
		goto out_free;
1303
	}
1304 1305

	if (!peeked)
1306 1307
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1308

1309
	sock_recv_ts_and_drops(msg, sk, skb);
1310 1311

	/* Copy the address. */
E
Eric Dumazet 已提交
1312
	if (sin) {
1313 1314 1315 1316
		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));
1317
		*addr_len = sizeof(*sin);
1318 1319 1320 1321
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);

1322
	err = copied;
1323 1324 1325 1326
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1327
	skb_free_datagram_locked(sk, skb);
1328 1329 1330 1331
out:
	return err;

csum_copy_err:
1332
	slow = lock_sock_fast(sk);
1333 1334
	if (!skb_kill_datagram(sk, skb, flags)) {
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1335
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1336
	}
1337
	unlock_sock_fast(sk, slow);
1338 1339 1340

	if (noblock)
		return -EAGAIN;
1341 1342 1343

	/* starting over for a new packet */
	msg->msg_flags &= ~MSG_TRUNC;
1344 1345 1346 1347
	goto try_again;
}


L
Linus Torvalds 已提交
1348 1349 1350 1351 1352 1353
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1354

L
Linus Torvalds 已提交
1355
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1356 1357
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1358
	sock_rps_reset_rxhash(sk);
L
Linus Torvalds 已提交
1359 1360 1361 1362 1363 1364
	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
1365
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1366 1367 1368 1369
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1370
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1371

1372 1373
void udp_lib_unhash(struct sock *sk)
{
1374 1375
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1376 1377 1378 1379 1380
		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);
1381

1382 1383
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1384
			hslot->count--;
E
Eric Dumazet 已提交
1385
			inet_sk(sk)->inet_num = 0;
1386
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1387 1388 1389 1390 1391

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1392 1393
		}
		spin_unlock_bh(&hslot->lock);
1394 1395 1396 1397
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
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 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440
/*
 * 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
1441 1442
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1443
	int rc;
E
Eric Dumazet 已提交
1444

1445
	if (inet_sk(sk)->inet_daddr) {
1446
		sock_rps_save_rxhash(sk, skb);
1447 1448
		sk_mark_napi_id(sk, skb);
	}
T
Tom Herbert 已提交
1449

1450
	rc = sock_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1451 1452
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1453 1454

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1455
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1456 1457
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1458 1459
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
1460
		trace_udp_fail_queue_rcv_skb(rc, sk);
E
Eric Dumazet 已提交
1461
		return -1;
H
Herbert Xu 已提交
1462 1463 1464 1465 1466 1467
	}

	return 0;

}

1468 1469 1470 1471 1472 1473 1474 1475
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);

1476 1477 1478 1479 1480 1481 1482 1483
/* 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
1484
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496
{
	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);

1497
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
1498 1499
		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);

1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511
		/*
		 * 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 */
1512 1513
		encap_rcv = ACCESS_ONCE(up->encap_rcv);
		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1514 1515
			int ret;

1516 1517 1518 1519
			/* Verify checksum before giving to encap */
			if (udp_lib_checksum_complete(skb))
				goto csum_error;

1520
			ret = encap_rcv(sk, skb);
1521
			if (ret <= 0) {
1522 1523
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548
						 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  */
1549 1550
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
				       UDP_SKB_CB(skb)->cscov, skb->len);
1551 1552 1553 1554 1555 1556 1557 1558 1559
			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) {
1560 1561
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
1562 1563 1564 1565
			goto drop;
		}
	}

1566 1567
	if (rcu_access_pointer(sk->sk_filter) &&
	    udp_lib_checksum_complete(skb))
1568
		goto csum_error;
1569

1570

1571
	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
1572 1573
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
				 is_udplite);
1574
		goto drop;
1575
	}
1576

H
Herbert Xu 已提交
1577
	rc = 0;
1578

1579
	ipv4_pktinfo_prepare(sk, skb);
H
Herbert Xu 已提交
1580 1581 1582
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
1583
	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
Z
Zhu Yi 已提交
1584 1585 1586
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1587 1588 1589
	bh_unlock_sock(sk);

	return rc;
1590

1591 1592
csum_error:
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1593
drop:
1594
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1595
	atomic_inc(&sk->sk_drops);
1596 1597 1598 1599
	kfree_skb(skb);
	return -1;
}

1600 1601 1602 1603 1604 1605

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;
1606
	struct sock *sk;
1607 1608

	for (i = 0; i < count; i++) {
1609
		sk = stack[i];
1610 1611 1612
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1613 1614 1615 1616 1617 1618 1619 1620 1621
		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)
1622
			skb1 = NULL;
1623 1624

		sock_put(sk);
1625 1626 1627 1628 1629
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1630
/* For TCP sockets, sk_rx_dst is protected by socket lock
1631
 * For UDP, we use xchg() to guard against concurrent changes.
1632 1633
 */
static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
S
Shawn Bohrer 已提交
1634
{
1635 1636
	struct dst_entry *old;

1637 1638 1639
	dst_hold(dst);
	old = xchg(&sk->sk_rx_dst, dst);
	dst_release(old);
S
Shawn Bohrer 已提交
1640 1641
}

1642 1643 1644
/*
 *	Multicasts and broadcasts go to each listener.
 *
1645
 *	Note: called only from the BH handler context.
1646
 */
1647
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1648 1649
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1650
				    struct udp_table *udptable)
1651
{
1652
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1653 1654 1655 1656
	struct hlist_nulls_node *node;
	unsigned short hnum = ntohs(uh->dest);
	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
	int dif = skb->dev->ifindex;
1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667
	unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);

	if (use_hash2) {
		hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
			    udp_table.mask;
		hash2 = udp4_portaddr_hash(net, daddr, hnum) & udp_table.mask;
start_lookup:
		hslot = &udp_table.hash2[hash2];
		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
	}
1668

1669
	spin_lock(&hslot->lock);
1670
	sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) {
1671 1672 1673 1674 1675 1676 1677 1678 1679
		if (__udp_is_mcast_sock(net, sk,
					uh->dest, daddr,
					uh->source, saddr,
					dif, hnum)) {
			if (unlikely(count == ARRAY_SIZE(stack))) {
				flush_stack(stack, count, skb, ~0);
				count = 0;
			}
			stack[count++] = sk;
1680
			sock_hold(sk);
1681 1682 1683
		}
	}

1684
	spin_unlock(&hslot->lock);
1685

1686 1687 1688 1689 1690 1691
	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
	if (use_hash2 && hash2 != hash2_any) {
		hash2 = hash2_any;
		goto start_lookup;
	}

1692 1693 1694 1695 1696 1697 1698 1699
	/*
	 * do the slow work with no lock held
	 */
	if (count) {
		flush_stack(stack, count, skb, count - 1);
	} else {
		kfree_skb(skb);
	}
1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
	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;
	}

1722 1723
	return skb_checksum_init_zero_check(skb, proto, uh->check,
					    inet_compute_pseudo);
1724 1725 1726 1727 1728 1729
}

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

1730
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1731 1732 1733
		   int proto)
{
	struct sock *sk;
1734
	struct udphdr *uh;
1735
	unsigned short ulen;
E
Eric Dumazet 已提交
1736
	struct rtable *rt = skb_rtable(skb);
1737
	__be32 saddr, daddr;
1738
	struct net *net = dev_net(skb->dev);
1739 1740 1741 1742 1743 1744 1745

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

1746
	uh   = udp_hdr(skb);
1747
	ulen = ntohs(uh->len);
1748 1749 1750
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
	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;

1764 1765
	sk = skb_steal_sock(skb);
	if (sk) {
1766
		struct dst_entry *dst = skb_dst(skb);
S
Shawn Bohrer 已提交
1767 1768
		int ret;

1769 1770
		if (unlikely(sk->sk_rx_dst != dst))
			udp_sk_rx_dst_set(sk, dst);
1771

S
Shawn Bohrer 已提交
1772
		ret = udp_queue_rcv_skb(sk, skb);
1773
		sock_put(sk);
S
Shawn Bohrer 已提交
1774 1775 1776 1777 1778 1779 1780
		/* 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;
	}
1781

F
Fabian Frederick 已提交
1782 1783 1784 1785 1786
	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);
1787
	if (sk != NULL) {
1788 1789
		int ret;

1790 1791 1792 1793
		if (udp_sk(sk)->convert_csum && uh->check && !IS_UDPLITE(sk))
			skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
						 inet_compute_pseudo);

1794
		ret = udp_queue_rcv_skb(sk, skb);
1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812
		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;

1813
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1814 1815 1816 1817 1818 1819 1820 1821 1822 1823
	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:
1824
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1825 1826 1827 1828
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source),
		       ulen, skb->len,
		       &daddr, ntohs(uh->dest));
1829 1830 1831 1832 1833 1834 1835
	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).
	 */
1836
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1837 1838
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1839
		       ulen);
1840
	UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1841
drop:
1842
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1843 1844 1845 1846
	kfree_skb(skb);
	return 0;
}

S
Shawn Bohrer 已提交
1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860
/* 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];

1861 1862 1863 1864
	/* Do not bother scanning a too big list */
	if (hslot->count > 10)
		return NULL;

S
Shawn Bohrer 已提交
1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889
	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;
1890
		else if (unlikely(!__udp_is_mcast_sock(net, result,
S
Shawn Bohrer 已提交
1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916
						       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];
1917
	INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
S
Shawn Bohrer 已提交
1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945
	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)
{
1946 1947 1948
	struct net *net = dev_net(skb->dev);
	const struct iphdr *iph;
	const struct udphdr *uh;
S
Shawn Bohrer 已提交
1949 1950 1951 1952 1953 1954 1955 1956
	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;

1957 1958 1959
	iph = ip_hdr(skb);
	uh = udp_hdr(skb);

S
Shawn Bohrer 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
	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;
1974
	skb->destructor = sock_efree;
S
Shawn Bohrer 已提交
1975 1976 1977 1978 1979 1980 1981 1982
	dst = sk->sk_rx_dst;

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

1983 1984
int udp_rcv(struct sk_buff *skb)
{
1985
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1986 1987
}

1988
void udp_destroy_sock(struct sock *sk)
1989
{
T
Tom Parkin 已提交
1990
	struct udp_sock *up = udp_sk(sk);
1991
	bool slow = lock_sock_fast(sk);
1992
	udp_flush_pending_frames(sk);
1993
	unlock_sock_fast(sk, slow);
T
Tom Parkin 已提交
1994 1995 1996 1997 1998 1999
	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);
	}
2000 2001
}

L
Linus Torvalds 已提交
2002 2003 2004
/*
 *	Socket option code for UDP
 */
2005
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2006
		       char __user *optval, unsigned int optlen,
2007
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
2008 2009
{
	struct udp_sock *up = udp_sk(sk);
2010
	int val, valbool;
L
Linus Torvalds 已提交
2011
	int err = 0;
W
Wang Chen 已提交
2012
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
2013

E
Eric Dumazet 已提交
2014
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
2015 2016 2017 2018 2019
		return -EINVAL;

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

2020 2021
	valbool = val ? 1 : 0;

2022
	switch (optname) {
L
Linus Torvalds 已提交
2023 2024 2025 2026 2027 2028
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
2029
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
2030 2031 2032
			release_sock(sk);
		}
		break;
2033

L
Linus Torvalds 已提交
2034 2035 2036 2037 2038
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
2039 2040
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
2041
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
2042
			up->encap_type = val;
2043
			udp_encap_enable();
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

2051 2052 2053 2054 2055 2056 2057 2058
	case UDP_NO_CHECK6_TX:
		up->no_check6_tx = valbool;
		break;

	case UDP_NO_CHECK6_RX:
		up->no_check6_rx = valbool;
		break;

2059 2060 2061 2062 2063 2064
	/*
	 * 	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
2065
		if (!is_udplite)         /* Disable the option on UDP sockets */
2066 2067 2068
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
2069 2070
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
2071 2072 2073 2074
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

2075 2076
	/* 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
2077 2078
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
2079
		if (!is_udplite)         /* Disable the option on UDP sockets */
2080 2081 2082
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
2083 2084
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
2085 2086 2087 2088
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
2089 2090 2091
	default:
		err = -ENOPROTOOPT;
		break;
2092
	}
L
Linus Torvalds 已提交
2093 2094 2095

	return err;
}
E
Eric Dumazet 已提交
2096
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
2097

2098
int udp_setsockopt(struct sock *sk, int level, int optname,
2099
		   char __user *optval, unsigned int optlen)
2100 2101 2102 2103 2104 2105 2106 2107 2108
{
	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,
2109
			  char __user *optval, unsigned int optlen)
2110 2111 2112 2113 2114 2115 2116 2117
{
	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

2118 2119
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
2120 2121 2122 2123
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
2124
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
2125 2126 2127
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
2128

2129
	if (len < 0)
L
Linus Torvalds 已提交
2130 2131
		return -EINVAL;

2132
	switch (optname) {
L
Linus Torvalds 已提交
2133 2134 2135 2136 2137 2138 2139 2140
	case UDP_CORK:
		val = up->corkflag;
		break;

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

2141 2142 2143 2144 2145 2146 2147 2148
	case UDP_NO_CHECK6_TX:
		val = up->no_check6_tx;
		break;

	case UDP_NO_CHECK6_RX:
		val = up->no_check6_rx;
		break;

2149 2150 2151 2152 2153 2154 2155 2156 2157 2158
	/* 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
2159 2160
	default:
		return -ENOPROTOOPT;
2161
	}
L
Linus Torvalds 已提交
2162

2163
	if (put_user(len, optlen))
2164
		return -EFAULT;
E
Eric Dumazet 已提交
2165
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
2166
		return -EFAULT;
2167
	return 0;
L
Linus Torvalds 已提交
2168
}
E
Eric Dumazet 已提交
2169
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
2170

2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187
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
2188 2189 2190 2191 2192 2193
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
2194
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204
 *	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;
2205

2206 2207
	sock_rps_record_flow(sk);

L
Linus Torvalds 已提交
2208
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
2209 2210 2211
	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
2212 2213

	return mask;
2214

L
Linus Torvalds 已提交
2215
}
E
Eric Dumazet 已提交
2216
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
2217

2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230
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
2231
	.backlog_rcv	   = __udp_queue_rcv_skb,
2232
	.release_cb	   = ip4_datagram_release_cb,
2233 2234
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
2235
	.rehash		   = udp_v4_rehash,
2236 2237 2238 2239 2240 2241
	.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),
2242
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
2243
	.h.udp_table	   = &udp_table,
2244 2245 2246 2247
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
2248
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
2249
};
E
Eric Dumazet 已提交
2250
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
2251 2252 2253 2254

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

2255
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
2256 2257 2258
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
2259
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2260

2261 2262
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
2263
		struct hlist_nulls_node *node;
2264
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2265 2266 2267 2268

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

2269
		spin_lock_bh(&hslot->lock);
2270
		sk_nulls_for_each(sk, node, &hslot->head) {
2271
			if (!net_eq(sock_net(sk), net))
2272
				continue;
L
Linus Torvalds 已提交
2273 2274 2275
			if (sk->sk_family == state->family)
				goto found;
		}
2276
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
2277 2278 2279 2280 2281 2282 2283 2284 2285
	}
	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;
2286
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2287 2288

	do {
2289
		sk = sk_nulls_next(sk);
2290
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
2291

2292
	if (!sk) {
2293
		if (state->bucket <= state->udp_table->mask)
2294
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2295
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
2296 2297 2298 2299 2300 2301
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
2302
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
2303 2304

	if (sk)
2305
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
2306 2307 2308 2309 2310 2311
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
2312
	struct udp_iter_state *state = seq->private;
2313
	state->bucket = MAX_UDP_PORTS;
2314

2315
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
2316 2317 2318 2319 2320 2321
}

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

2322
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
2323 2324 2325 2326 2327 2328 2329 2330 2331 2332
		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)
{
2333 2334
	struct udp_iter_state *state = seq->private;

2335
	if (state->bucket <= state->udp_table->mask)
2336
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2337 2338
}

2339
int udp_seq_open(struct inode *inode, struct file *file)
L
Linus Torvalds 已提交
2340
{
A
Al Viro 已提交
2341
	struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2342 2343
	struct udp_iter_state *s;
	int err;
2344

2345 2346 2347 2348
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2349

2350
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2351
	s->family		= afinfo->family;
2352
	s->udp_table		= afinfo->udp_table;
2353
	return err;
2354
}
2355
EXPORT_SYMBOL(udp_seq_open);
2356

L
Linus Torvalds 已提交
2357
/* ------------------------------------------------------------------------ */
2358
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2359 2360 2361 2362
{
	struct proc_dir_entry *p;
	int rc = 0;

2363 2364 2365 2366
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2367
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2368
			     afinfo->seq_fops, afinfo);
2369
	if (!p)
L
Linus Torvalds 已提交
2370 2371 2372
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2373
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2374

2375
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2376
{
2377
	remove_proc_entry(afinfo->name, net->proc_net);
L
Linus Torvalds 已提交
2378
}
E
Eric Dumazet 已提交
2379
EXPORT_SYMBOL(udp_proc_unregister);
2380 2381

/* ------------------------------------------------------------------------ */
2382
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2383
		int bucket)
2384 2385
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2386 2387 2388 2389
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2390

2391
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2392
		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2393
		bucket, src, srcp, dest, destp, sp->sk_state,
2394 2395
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2396 2397 2398
		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
2399
		atomic_read(&sp->sk_refcnt), sp,
2400
		atomic_read(&sp->sk_drops));
2401 2402 2403 2404
}

int udp4_seq_show(struct seq_file *seq, void *v)
{
2405
	seq_setwidth(seq, 127);
2406
	if (v == SEQ_START_TOKEN)
2407
		seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
2408
			   "rx_queue tr tm->when retrnsmt   uid  timeout "
E
Eric Dumazet 已提交
2409
			   "inode ref pointer drops");
2410 2411 2412
	else {
		struct udp_iter_state *state = seq->private;

2413
		udp4_format_sock(v, seq, state->bucket);
2414
	}
2415
	seq_pad(seq, '\n');
2416 2417 2418
	return 0;
}

2419 2420 2421 2422 2423 2424 2425 2426
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
};

2427 2428 2429 2430
/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2431
	.udp_table	= &udp_table,
2432
	.seq_fops	= &udp_afinfo_seq_fops,
2433 2434 2435
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2436 2437
};

2438
static int __net_init udp4_proc_init_net(struct net *net)
2439 2440 2441 2442
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2443
static void __net_exit udp4_proc_exit_net(struct net *net)
2444 2445 2446 2447 2448 2449 2450 2451 2452
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2453 2454
int __init udp4_proc_init(void)
{
2455
	return register_pernet_subsys(&udp4_net_ops);
2456 2457 2458 2459
}

void udp4_proc_exit(void)
{
2460
	unregister_pernet_subsys(&udp4_net_ops);
2461
}
L
Linus Torvalds 已提交
2462 2463
#endif /* CONFIG_PROC_FS */

2464 2465
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2466
{
2467 2468
	ssize_t ret;

2469 2470
	if (!str)
		return 0;
2471 2472 2473 2474 2475

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

2476 2477 2478 2479 2480
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2481

2482 2483 2484 2485
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

2486 2487 2488 2489 2490 2491 2492 2493 2494 2495
	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);

2496
	table->hash2 = table->hash + (table->mask + 1);
2497
	for (i = 0; i <= table->mask; i++) {
2498
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2499
		table->hash[i].count = 0;
2500 2501
		spin_lock_init(&table->hash[i].lock);
	}
2502 2503 2504 2505 2506
	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);
	}
2507 2508
}

H
Hideo Aoki 已提交
2509 2510
void __init udp_init(void)
{
2511
	unsigned long limit;
H
Hideo Aoki 已提交
2512

2513
	udp_table_init(&udp_table, "UDP");
2514
	limit = nr_free_buffer_pages() / 8;
H
Hideo Aoki 已提交
2515 2516 2517 2518 2519 2520 2521 2522
	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;
}