udp.c 59.4 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>
#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>
#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(&low, &high);
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		remaining = (high - low) + 1;
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		rand = net_random();
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		first = (((u64)rand * remaining) >> 32) + low;
		/*
		 * 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) &&
				    !inet_is_reserved_local_port(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;
}


/* 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) {
				hash = inet_ehashfn(net, daddr, hnum,
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						    saddr, sport);
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				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
			if (((u64)hash * matches) >> 32 == 0)
				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,
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		__be16 sport, __be32 daddr, __be16 dport,
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		int dif, struct udp_table *udptable)
468
{
469
	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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	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) {
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			hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
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			slot2 = hash2 & udptable->mask;
			hslot2 = &udptable->hash2[slot2];
			if (hslot->count < hslot2->count)
				goto begin;

495
			result = udp4_lib_lookup2(net, saddr, sport,
496
						  htonl(INADDR_ANY), hnum, dif,
E
Eric Dumazet 已提交
497 498 499 500 501
						  hslot2, slot2);
		}
		rcu_read_unlock();
		return result;
	}
502 503
begin:
	result = NULL;
504
	badness = 0;
505
	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
506 507 508 509 510
		score = compute_score(sk, net, saddr, hnum, sport,
				      daddr, dport, dif);
		if (score > badness) {
			result = sk;
			badness = score;
511 512 513
			reuseport = sk->sk_reuseport;
			if (reuseport) {
				hash = inet_ehashfn(net, daddr, hnum,
E
Eric Dumazet 已提交
514
						    saddr, sport);
515 516 517 518 519 520 521
				matches = 1;
			}
		} else if (score == badness && reuseport) {
			matches++;
			if (((u64)hash * matches) >> 32 == 0)
				result = sk;
			hash = next_pseudo_random32(hash);
522 523
		}
	}
524 525 526 527 528
	/*
	 * 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
529
	if (get_nulls_value(node) != slot)
530 531
		goto begin;

532
	if (result) {
E
Eric Dumazet 已提交
533
		if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
534 535 536 537 538 539 540 541
			result = NULL;
		else if (unlikely(compute_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
542 543
	return result;
}
544
EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
545

546 547
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
						 __be16 sport, __be16 dport,
548
						 struct udp_table *udptable)
549
{
550
	struct sock *sk;
551 552
	const struct iphdr *iph = ip_hdr(skb);

553 554 555
	if (unlikely(sk = skb_steal_sock(skb)))
		return sk;
	else
E
Eric Dumazet 已提交
556
		return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
557 558
					 iph->daddr, dport, inet_iif(skb),
					 udptable);
559 560
}

561 562 563
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
564
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
565 566 567
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

568
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
569 570 571 572
					     __be16 loc_port, __be32 loc_addr,
					     __be16 rmt_port, __be32 rmt_addr,
					     int dif)
{
573
	struct hlist_nulls_node *node;
574 575 576
	struct sock *s = sk;
	unsigned short hnum = ntohs(loc_port);

577
	sk_nulls_for_each_from(s, node) {
578 579
		struct inet_sock *inet = inet_sk(s);

580 581 582 583 584 585 586
		if (!net_eq(sock_net(s), net) ||
		    udp_sk(s)->udp_port_hash != hnum ||
		    (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
		    (inet->inet_dport != rmt_port && inet->inet_dport) ||
		    (inet->inet_rcv_saddr &&
		     inet->inet_rcv_saddr != loc_addr) ||
		    ipv6_only_sock(s) ||
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608
		    (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
			continue;
		if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
			continue;
		goto found;
	}
	s = NULL;
found:
	return s;
}

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

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;
659 660 661
	case ICMP_REDIRECT:
		ipv4_sk_redirect(skb, sk);
		break;
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
 */
H
Herbert Xu 已提交
707
static 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
710 711 712 713
	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
	int hlen = len;
714 715
	__wsum csum = 0;

H
Herbert Xu 已提交
716
	if (!frags) {
717 718 719 720 721
		/*
		 * 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
722 723
		uh->check = ~csum_tcpudp_magic(src, dst, len,
					       IPPROTO_UDP, 0);
724 725 726 727 728 729
	} 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
730 731 732 733
		do {
			csum = csum_add(csum, frags->csum);
			hlen -= frags->len;
		} while ((frags = frags->next));
734

H
Herbert Xu 已提交
735
		csum = skb_checksum(skb, offset, hlen, csum);
736 737 738 739 740 741 742 743
		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
static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
745
{
H
Herbert Xu 已提交
746
	struct sock *sk = skb->sk;
747 748 749 750
	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
751 752
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
753 754 755 756 757 758
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
759
	uh->source = inet->inet_sport;
760
	uh->dest = fl4->fl4_dport;
H
Herbert Xu 已提交
761
	uh->len = htons(len);
762 763 764
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
765
		csum = udplite_csum(skb);
766 767 768 769 770 771 772 773

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

		skb->ip_summed = CHECKSUM_NONE;
		goto send;

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

774
		udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
775 776
		goto send;

H
Herbert Xu 已提交
777 778
	} else
		csum = udp_csum(skb);
779 780

	/* add protocol-dependent pseudo-header */
781
	uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
E
Eric Dumazet 已提交
782
				      sk->sk_protocol, csum);
783 784 785 786
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
E
Eric Dumazet 已提交
787
	err = ip_send_skb(sock_net(sk), skb);
E
Eric Dumazet 已提交
788 789 790 791 792 793 794 795 796
	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
797 798 799 800 801 802
	return err;
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
803
int udp_push_pending_frames(struct sock *sk)
H
Herbert Xu 已提交
804 805 806
{
	struct udp_sock  *up = udp_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
D
David S. Miller 已提交
807
	struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
H
Herbert Xu 已提交
808 809 810
	struct sk_buff *skb;
	int err = 0;

811
	skb = ip_finish_skb(sk, fl4);
H
Herbert Xu 已提交
812 813 814
	if (!skb)
		goto out;

815
	err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
816

817 818 819 820 821
out:
	up->len = 0;
	up->pending = 0;
	return err;
}
822
EXPORT_SYMBOL(udp_push_pending_frames);
823 824 825 826 827 828

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);
829
	struct flowi4 fl4_stack;
D
David S. Miller 已提交
830
	struct flowi4 *fl4;
831 832 833 834 835 836 837 838 839 840 841
	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
842
	struct sk_buff *skb;
843
	struct ip_options_data opt_copy;
844 845 846 847 848 849 850 851

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
852
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
853 854 855
		return -EOPNOTSUPP;

	ipc.opt = NULL;
856
	ipc.tx_flags = 0;
857

H
Herbert Xu 已提交
858 859
	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;

860
	fl4 = &inet->cork.fl.u.ip4;
861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881
	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) {
D
Daniel Baluta 已提交
882
		struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
883 884 885 886 887 888 889 890 891 892 893 894 895 896
		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
897 898
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
899 900 901 902 903
		/* 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
904
	ipc.addr = inet->inet_saddr;
905 906

	ipc.oif = sk->sk_bound_dev_if;
907 908 909

	sock_tx_timestamp(sk, &ipc.tx_flags);

910
	if (msg->msg_controllen) {
911
		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
912 913 914 915 916 917
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
918 919 920 921 922 923 924 925 926 927 928 929
	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();
	}
930 931 932 933

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

934
	if (ipc.opt && ipc.opt->opt.srr) {
935 936
		if (!daddr)
			return -EINVAL;
937
		faddr = ipc.opt->opt.faddr;
938 939 940 941 942
		connected = 0;
	}
	tos = RT_TOS(inet->tos);
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
943
	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
944 945 946 947 948 949 950 951 952 953
		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;
954 955
	} else if (!ipc.oif)
		ipc.oif = inet->uc_index;
956 957

	if (connected)
E
Eric Dumazet 已提交
958
		rt = (struct rtable *)sk_dst_check(sk, 0);
959 960

	if (rt == NULL) {
961 962
		struct net *net = sock_net(sk);

963 964
		fl4 = &fl4_stack;
		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
965 966 967 968
				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
				   inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
				   faddr, saddr, dport, inet->inet_sport);

969 970
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		rt = ip_route_output_flow(net, fl4, sk);
971 972
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
973
			rt = NULL;
974
			if (err == -ENETUNREACH)
975
				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
976 977 978 979 980 981 982 983
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
984
			sk_dst_set(sk, dst_clone(&rt->dst));
985 986 987 988 989 990
	}

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

991
	saddr = fl4->saddr;
992
	if (!ipc.addr)
993
		daddr = ipc.addr = fl4->daddr;
994

H
Herbert Xu 已提交
995 996
	/* Lockless fast path for the non-corking case. */
	if (!corkreq) {
997
		skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
H
Herbert Xu 已提交
998 999 1000
				  sizeof(struct udphdr), &ipc, &rt,
				  msg->msg_flags);
		err = PTR_ERR(skb);
1001
		if (!IS_ERR_OR_NULL(skb))
1002
			err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
1003 1004 1005
		goto out;
	}

1006 1007 1008 1009 1010 1011
	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);

1012
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1013 1014 1015 1016 1017 1018
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
D
David S. Miller 已提交
1019 1020 1021
	fl4 = &inet->cork.fl.u.ip4;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
1022 1023
	fl4->fl4_dport = dport;
	fl4->fl4_sport = inet->inet_sport;
1024 1025 1026 1027
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
1028 1029 1030
	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);
1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
	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)) {
1053 1054
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
1055 1056 1057 1058
	}
	return err;

do_confirm:
1059
	dst_confirm(&rt->dst);
1060 1061 1062 1063 1064
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1065
EXPORT_SYMBOL(udp_sendmsg);
1066 1067 1068 1069

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
1070
	struct inet_sock *inet = inet_sk(sk);
1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090
	struct udp_sock *up = udp_sk(sk);
	int ret;

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

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

	lock_sock(sk);

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

1091
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1092 1093 1094
		return -EINVAL;
	}

1095 1096
	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
			     page, offset, size, flags);
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116
	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
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135

/**
 *	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)) {
1136 1137
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1138 1139
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1140
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1141 1142 1143 1144 1145 1146 1147
		__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)) {
1148 1149
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1150 1151
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1152
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1153 1154 1155 1156
	}
	return res;
}

L
Linus Torvalds 已提交
1157 1158 1159
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1160

L
Linus Torvalds 已提交
1161 1162
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1163 1164
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1165
	{
1166 1167
		int amount = sk_wmem_alloc_get(sk);

1168 1169
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1170

1171 1172
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1173
		unsigned int amount = first_packet_length(sk);
1174

E
Eric Dumazet 已提交
1175
		if (amount)
1176 1177 1178 1179 1180
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1181 1182
			amount -= sizeof(struct udphdr);

1183 1184
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1185

1186 1187
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1188
	}
1189 1190

	return 0;
L
Linus Torvalds 已提交
1191
}
E
Eric Dumazet 已提交
1192
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1193

1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
/*
 * 	This should be easy, if there is something there we
 * 	return it, otherwise we block.
 */

int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
		size_t len, int noblock, int flags, int *addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
	struct sk_buff *skb;
1205
	unsigned int ulen, copied;
1206
	int peeked, off = 0;
1207 1208
	int err;
	int is_udplite = IS_UDPLITE(sk);
1209
	bool slow;
1210 1211 1212 1213 1214

	/*
	 *	Check any passed addresses
	 */
	if (addr_len)
E
Eric Dumazet 已提交
1215
		*addr_len = sizeof(*sin);
1216 1217 1218 1219 1220 1221

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

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1222
				  &peeked, &off, &err);
1223 1224 1225 1226
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
1227 1228 1229 1230
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
1231 1232 1233 1234 1235 1236 1237 1238
		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.
	 */

1239
	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1240 1241 1242 1243 1244 1245
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1246
					      msg->msg_iov, copied);
1247
	else {
E
Eric Dumazet 已提交
1248 1249 1250
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1251 1252 1253 1254 1255

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

1256 1257
	if (unlikely(err)) {
		trace_kfree_skb(skb, udp_recvmsg);
1258 1259 1260 1261 1262
		if (!peeked) {
			atomic_inc(&sk->sk_drops);
			UDP_INC_STATS_USER(sock_net(sk),
					   UDP_MIB_INERRORS, is_udplite);
		}
1263
		goto out_free;
1264
	}
1265 1266

	if (!peeked)
1267 1268
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1269

1270
	sock_recv_ts_and_drops(msg, sk, skb);
1271 1272

	/* Copy the address. */
E
Eric Dumazet 已提交
1273
	if (sin) {
1274 1275 1276 1277 1278 1279 1280 1281
		sin->sin_family = AF_INET;
		sin->sin_port = udp_hdr(skb)->source;
		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
		memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);

1282
	err = copied;
1283 1284 1285 1286
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1287
	skb_free_datagram_locked(sk, skb);
1288 1289 1290 1291
out:
	return err;

csum_copy_err:
1292
	slow = lock_sock_fast(sk);
1293 1294
	if (!skb_kill_datagram(sk, skb, flags)) {
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1295
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1296
	}
1297
	unlock_sock_fast(sk, slow);
1298 1299 1300

	if (noblock)
		return -EAGAIN;
1301 1302 1303

	/* starting over for a new packet */
	msg->msg_flags &= ~MSG_TRUNC;
1304 1305 1306 1307
	goto try_again;
}


L
Linus Torvalds 已提交
1308 1309 1310 1311 1312 1313
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1314

L
Linus Torvalds 已提交
1315
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1316 1317
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1318
	sock_rps_reset_rxhash(sk);
L
Linus Torvalds 已提交
1319 1320 1321 1322 1323 1324
	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
1325
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1326 1327 1328 1329
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1330
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1331

1332 1333
void udp_lib_unhash(struct sock *sk)
{
1334 1335
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1336 1337 1338 1339 1340
		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);
1341

1342 1343
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1344
			hslot->count--;
E
Eric Dumazet 已提交
1345
			inet_sk(sk)->inet_num = 0;
1346
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1347 1348 1349 1350 1351

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1352 1353
		}
		spin_unlock_bh(&hslot->lock);
1354 1355 1356 1357
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400
/*
 * 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
1401 1402
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1403
	int rc;
E
Eric Dumazet 已提交
1404

T
Tom Herbert 已提交
1405
	if (inet_sk(sk)->inet_daddr)
1406
		sock_rps_save_rxhash(sk, skb);
T
Tom Herbert 已提交
1407

1408
	rc = sock_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1409 1410
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1411 1412

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1413
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1414 1415
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1416 1417
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
1418
		trace_udp_fail_queue_rcv_skb(rc, sk);
E
Eric Dumazet 已提交
1419
		return -1;
H
Herbert Xu 已提交
1420 1421 1422 1423 1424 1425
	}

	return 0;

}

1426 1427 1428 1429 1430 1431 1432 1433
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);

1434 1435 1436 1437 1438 1439 1440 1441
/* 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
1442
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
{
	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);

1455
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
1456 1457
		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);

1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469
		/*
		 * 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 */
1470 1471
		encap_rcv = ACCESS_ONCE(up->encap_rcv);
		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1472 1473
			int ret;

1474
			ret = encap_rcv(sk, skb);
1475
			if (ret <= 0) {
1476 1477
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502
						 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  */
1503 1504
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
				       UDP_SKB_CB(skb)->cscov, skb->len);
1505 1506 1507 1508 1509 1510 1511 1512 1513
			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) {
1514 1515
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
1516 1517 1518 1519
			goto drop;
		}
	}

1520 1521
	if (rcu_access_pointer(sk->sk_filter) &&
	    udp_lib_checksum_complete(skb))
1522
		goto csum_error;
1523

1524

1525
	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1526 1527
		goto drop;

H
Herbert Xu 已提交
1528
	rc = 0;
1529

1530
	ipv4_pktinfo_prepare(skb);
H
Herbert Xu 已提交
1531 1532 1533
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
1534
	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
Z
Zhu Yi 已提交
1535 1536 1537
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1538 1539 1540
	bh_unlock_sock(sk);

	return rc;
1541

1542 1543
csum_error:
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1544
drop:
1545
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1546
	atomic_inc(&sk->sk_drops);
1547 1548 1549 1550
	kfree_skb(skb);
	return -1;
}

1551 1552 1553 1554 1555 1556

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;
1557
	struct sock *sk;
1558 1559

	for (i = 0; i < count; i++) {
1560
		sk = stack[i];
1561 1562 1563
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1564 1565 1566 1567 1568 1569 1570 1571 1572
		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)
1573 1574 1575 1576 1577 1578
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1579 1580 1581
/*
 *	Multicasts and broadcasts go to each listener.
 *
1582
 *	Note: called only from the BH handler context.
1583
 */
1584
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1585 1586
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1587
				    struct udp_table *udptable)
1588
{
1589
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1590
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1591
	int dif;
1592
	unsigned int i, count = 0;
1593

1594
	spin_lock(&hslot->lock);
1595
	sk = sk_nulls_head(&hslot->head);
1596
	dif = skb->dev->ifindex;
1597
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614
	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]);

1615
	spin_unlock(&hslot->lock);
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627

	/*
	 * 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);
	}
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654
	return 0;
}

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

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

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

	iph = ip_hdr(skb);
	if (uh->check == 0) {
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
E
Eric Dumazet 已提交
1655
		if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
				      proto, skb->csum))
			skb->ip_summed = CHECKSUM_UNNECESSARY;
	}
	if (!skb_csum_unnecessary(skb))
		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
					       skb->len, proto, 0);
	/* Probably, we should checksum udp header (it should be in cache
	 * in any case) and data in tiny packets (< rx copybreak).
	 */

	return 0;
}

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

1673
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1674 1675 1676
		   int proto)
{
	struct sock *sk;
1677
	struct udphdr *uh;
1678
	unsigned short ulen;
E
Eric Dumazet 已提交
1679
	struct rtable *rt = skb_rtable(skb);
1680
	__be32 saddr, daddr;
1681
	struct net *net = dev_net(skb->dev);
1682 1683 1684 1685 1686 1687 1688

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

1689
	uh   = udp_hdr(skb);
1690
	ulen = ntohs(uh->len);
1691 1692 1693
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707
	if (ulen > skb->len)
		goto short_packet;

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

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

	if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1708 1709
		return __udp4_lib_mcast_deliver(net, skb, uh,
				saddr, daddr, udptable);
1710

1711
	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1712 1713

	if (sk != NULL) {
1714 1715
		int ret;

1716
		sk_mark_napi_id(sk, skb);
1717
		ret = udp_queue_rcv_skb(sk, skb);
1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735
		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;

1736
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746
	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:
1747
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1748 1749 1750 1751
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source),
		       ulen, skb->len,
		       &daddr, ntohs(uh->dest));
1752 1753 1754 1755 1756 1757 1758
	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).
	 */
1759
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1760 1761
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1762
		       ulen);
1763
	UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1764
drop:
1765
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1766 1767 1768 1769 1770 1771
	kfree_skb(skb);
	return 0;
}

int udp_rcv(struct sk_buff *skb)
{
1772
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1773 1774
}

1775
void udp_destroy_sock(struct sock *sk)
1776
{
T
Tom Parkin 已提交
1777
	struct udp_sock *up = udp_sk(sk);
1778
	bool slow = lock_sock_fast(sk);
1779
	udp_flush_pending_frames(sk);
1780
	unlock_sock_fast(sk, slow);
T
Tom Parkin 已提交
1781 1782 1783 1784 1785 1786
	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);
	}
1787 1788
}

L
Linus Torvalds 已提交
1789 1790 1791
/*
 *	Socket option code for UDP
 */
1792
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1793
		       char __user *optval, unsigned int optlen,
1794
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1795 1796 1797 1798
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1799
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1800

E
Eric Dumazet 已提交
1801
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1802 1803 1804 1805 1806
		return -EINVAL;

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

1807
	switch (optname) {
L
Linus Torvalds 已提交
1808 1809 1810 1811 1812 1813
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1814
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1815 1816 1817
			release_sock(sk);
		}
		break;
1818

L
Linus Torvalds 已提交
1819 1820 1821 1822 1823
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1824 1825
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
1826
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
1827
			up->encap_type = val;
1828
			udp_encap_enable();
L
Linus Torvalds 已提交
1829 1830 1831 1832 1833 1834 1835
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

1836 1837 1838 1839 1840 1841
	/*
	 * 	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
1842
		if (!is_udplite)         /* Disable the option on UDP sockets */
1843 1844 1845
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
1846 1847
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1848 1849 1850 1851
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

1852 1853
	/* 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
1854 1855
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
1856
		if (!is_udplite)         /* Disable the option on UDP sockets */
1857 1858 1859
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
1860 1861
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1862 1863 1864 1865
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
1866 1867 1868
	default:
		err = -ENOPROTOOPT;
		break;
1869
	}
L
Linus Torvalds 已提交
1870 1871 1872

	return err;
}
E
Eric Dumazet 已提交
1873
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
1874

1875
int udp_setsockopt(struct sock *sk, int level, int optname,
1876
		   char __user *optval, unsigned int optlen)
1877 1878 1879 1880 1881 1882 1883 1884 1885
{
	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,
1886
			  char __user *optval, unsigned int optlen)
1887 1888 1889 1890 1891 1892 1893 1894
{
	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

1895 1896
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
1897 1898 1899 1900
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
1901
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
1902 1903 1904
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
1905

1906
	if (len < 0)
L
Linus Torvalds 已提交
1907 1908
		return -EINVAL;

1909
	switch (optname) {
L
Linus Torvalds 已提交
1910 1911 1912 1913 1914 1915 1916 1917
	case UDP_CORK:
		val = up->corkflag;
		break;

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

1918 1919 1920 1921 1922 1923 1924 1925 1926 1927
	/* 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
1928 1929
	default:
		return -ENOPROTOOPT;
1930
	}
L
Linus Torvalds 已提交
1931

1932
	if (put_user(len, optlen))
1933
		return -EFAULT;
E
Eric Dumazet 已提交
1934
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
1935
		return -EFAULT;
1936
	return 0;
L
Linus Torvalds 已提交
1937
}
E
Eric Dumazet 已提交
1938
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
1939

1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
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
1957 1958 1959 1960 1961 1962
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
1963
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
 *	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;
1974

1975 1976
	sock_rps_record_flow(sk);

L
Linus Torvalds 已提交
1977
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
1978 1979 1980
	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
1981 1982

	return mask;
1983

L
Linus Torvalds 已提交
1984
}
E
Eric Dumazet 已提交
1985
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
1986

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
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
2000
	.backlog_rcv	   = __udp_queue_rcv_skb,
2001
	.release_cb	   = ip4_datagram_release_cb,
2002 2003
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
2004
	.rehash		   = udp_v4_rehash,
2005 2006 2007 2008 2009 2010
	.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),
2011
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
2012
	.h.udp_table	   = &udp_table,
2013 2014 2015 2016
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
2017
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
2018
};
E
Eric Dumazet 已提交
2019
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
2020 2021 2022 2023

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

2024
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
2025 2026 2027
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
2028
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2029

2030 2031
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
2032
		struct hlist_nulls_node *node;
2033
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2034 2035 2036 2037

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

2038
		spin_lock_bh(&hslot->lock);
2039
		sk_nulls_for_each(sk, node, &hslot->head) {
2040
			if (!net_eq(sock_net(sk), net))
2041
				continue;
L
Linus Torvalds 已提交
2042 2043 2044
			if (sk->sk_family == state->family)
				goto found;
		}
2045
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
2046 2047 2048 2049 2050 2051 2052 2053 2054
	}
	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;
2055
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2056 2057

	do {
2058
		sk = sk_nulls_next(sk);
2059
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
2060

2061
	if (!sk) {
2062
		if (state->bucket <= state->udp_table->mask)
2063
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2064
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
2065 2066 2067 2068 2069 2070
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
2071
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
2072 2073

	if (sk)
2074
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
2075 2076 2077 2078 2079 2080
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
2081
	struct udp_iter_state *state = seq->private;
2082
	state->bucket = MAX_UDP_PORTS;
2083

2084
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
2085 2086 2087 2088 2089 2090
}

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

2091
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
		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)
{
2102 2103
	struct udp_iter_state *state = seq->private;

2104
	if (state->bucket <= state->udp_table->mask)
2105
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2106 2107
}

2108
int udp_seq_open(struct inode *inode, struct file *file)
L
Linus Torvalds 已提交
2109
{
A
Al Viro 已提交
2110
	struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2111 2112
	struct udp_iter_state *s;
	int err;
2113

2114 2115 2116 2117
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2118

2119
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2120
	s->family		= afinfo->family;
2121
	s->udp_table		= afinfo->udp_table;
2122
	return err;
2123
}
2124
EXPORT_SYMBOL(udp_seq_open);
2125

L
Linus Torvalds 已提交
2126
/* ------------------------------------------------------------------------ */
2127
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2128 2129 2130 2131
{
	struct proc_dir_entry *p;
	int rc = 0;

2132 2133 2134 2135
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2136
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2137
			     afinfo->seq_fops, afinfo);
2138
	if (!p)
L
Linus Torvalds 已提交
2139 2140 2141
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2142
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2143

2144
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2145
{
2146
	remove_proc_entry(afinfo->name, net->proc_net);
L
Linus Torvalds 已提交
2147
}
E
Eric Dumazet 已提交
2148
EXPORT_SYMBOL(udp_proc_unregister);
2149 2150

/* ------------------------------------------------------------------------ */
2151 2152
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
		int bucket, int *len)
2153 2154
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2155 2156 2157 2158
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2159

2160
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
D
Dan Rosenberg 已提交
2161
		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
2162
		bucket, src, srcp, dest, destp, sp->sk_state,
2163 2164
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2165 2166 2167
		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
2168 2169
		atomic_read(&sp->sk_refcnt), sp,
		atomic_read(&sp->sk_drops), len);
2170 2171 2172 2173 2174 2175 2176 2177
}

int udp4_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_printf(seq, "%-127s\n",
			   "  sl  local_address rem_address   st tx_queue "
			   "rx_queue tr tm->when retrnsmt   uid  timeout "
E
Eric Dumazet 已提交
2178
			   "inode ref pointer drops");
2179 2180
	else {
		struct udp_iter_state *state = seq->private;
2181
		int len;
2182

2183
		udp4_format_sock(v, seq, state->bucket, &len);
E
Eric Dumazet 已提交
2184
		seq_printf(seq, "%*s\n", 127 - len, "");
2185 2186 2187 2188
	}
	return 0;
}

2189 2190 2191 2192 2193 2194 2195 2196
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
};

2197 2198 2199 2200
/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2201
	.udp_table	= &udp_table,
2202
	.seq_fops	= &udp_afinfo_seq_fops,
2203 2204 2205
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2206 2207
};

2208
static int __net_init udp4_proc_init_net(struct net *net)
2209 2210 2211 2212
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2213
static void __net_exit udp4_proc_exit_net(struct net *net)
2214 2215 2216 2217 2218 2219 2220 2221 2222
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2223 2224
int __init udp4_proc_init(void)
{
2225
	return register_pernet_subsys(&udp4_net_ops);
2226 2227 2228 2229
}

void udp4_proc_exit(void)
{
2230
	unregister_pernet_subsys(&udp4_net_ops);
2231
}
L
Linus Torvalds 已提交
2232 2233
#endif /* CONFIG_PROC_FS */

2234 2235
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2236
{
2237 2238
	ssize_t ret;

2239 2240
	if (!str)
		return 0;
2241 2242 2243 2244 2245

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

2246 2247 2248 2249 2250
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2251

2252 2253 2254 2255
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

2256 2257 2258 2259 2260 2261 2262 2263 2264 2265
	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);

2266
	table->hash2 = table->hash + (table->mask + 1);
2267
	for (i = 0; i <= table->mask; i++) {
2268
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2269
		table->hash[i].count = 0;
2270 2271
		spin_lock_init(&table->hash[i].lock);
	}
2272 2273 2274 2275 2276
	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);
	}
2277 2278
}

H
Hideo Aoki 已提交
2279 2280
void __init udp_init(void)
{
2281
	unsigned long limit;
H
Hideo Aoki 已提交
2282

2283
	udp_table_init(&udp_table, "UDP");
2284
	limit = nr_free_buffer_pages() / 8;
H
Hideo Aoki 已提交
2285 2286 2287 2288 2289 2290 2291 2292 2293
	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;
}

2294 2295
struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
				       netdev_features_t features)
2296 2297 2298 2299
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	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
2300
	__be16 protocol = skb->protocol;
2301
	netdev_features_t enc_features;
P
Pravin B Shelar 已提交
2302
	int outer_hlen;
2303 2304 2305 2306 2307 2308 2309 2310 2311

	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);
2312
	skb->protocol = htons(ETH_P_TEB);
2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325

	/* segment inner packet. */
	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
	segs = skb_mac_gso_segment(skb, enc_features);
	if (!segs || IS_ERR(segs))
		goto out;

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

2326 2327 2328
		skb_reset_inner_headers(skb);
		skb->encapsulation = 1;

2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350
		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. */
		if (unlikely(uh->check)) {
			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;

		}
P
Pravin B Shelar 已提交
2351
		skb->protocol = protocol;
2352 2353 2354 2355
	} while ((skb = skb->next));
out:
	return segs;
}