udp.c 59.9 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(net, &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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477
	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
	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
710 711 712 713
	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
		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;
	}
}
743
EXPORT_SYMBOL_GPL(udp4_hwcsum);
744

745
static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
746
{
H
Herbert Xu 已提交
747
	struct sock *sk = skb->sk;
748 749 750 751
	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
752 753
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
754 755 756 757 758 759
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
760
	uh->source = inet->inet_sport;
761
	uh->dest = fl4->fl4_dport;
H
Herbert Xu 已提交
762
	uh->len = htons(len);
763 764 765
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
766
		csum = udplite_csum(skb);
767 768 769 770 771 772 773 774

	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 */

775
		udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
776 777
		goto send;

H
Herbert Xu 已提交
778 779
	} else
		csum = udp_csum(skb);
780 781

	/* add protocol-dependent pseudo-header */
782
	uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
E
Eric Dumazet 已提交
783
				      sk->sk_protocol, csum);
784 785 786 787
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
E
Eric Dumazet 已提交
788
	err = ip_send_skb(sock_net(sk), skb);
E
Eric Dumazet 已提交
789 790 791 792 793 794 795 796 797
	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
798 799 800 801 802 803
	return err;
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
804
int udp_push_pending_frames(struct sock *sk)
H
Herbert Xu 已提交
805 806 807
{
	struct udp_sock  *up = udp_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
D
David S. Miller 已提交
808
	struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
H
Herbert Xu 已提交
809 810 811
	struct sk_buff *skb;
	int err = 0;

812
	skb = ip_finish_skb(sk, fl4);
H
Herbert Xu 已提交
813 814 815
	if (!skb)
		goto out;

816
	err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
817

818 819 820 821 822
out:
	up->len = 0;
	up->pending = 0;
	return err;
}
823
EXPORT_SYMBOL(udp_push_pending_frames);
824 825 826 827 828 829

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);
830
	struct flowi4 fl4_stack;
D
David S. Miller 已提交
831
	struct flowi4 *fl4;
832 833 834 835 836 837 838 839 840 841 842
	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
843
	struct sk_buff *skb;
844
	struct ip_options_data opt_copy;
845 846 847 848 849 850 851 852

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
853
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
854 855 856
		return -EOPNOTSUPP;

	ipc.opt = NULL;
857
	ipc.tx_flags = 0;
858 859
	ipc.ttl = 0;
	ipc.tos = -1;
860

H
Herbert Xu 已提交
861 862
	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;

863
	fl4 = &inet->cork.fl.u.ip4;
864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884
	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
885
		struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
886 887 888 889 890 891 892 893 894 895 896 897 898 899
		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
900 901
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
902 903 904 905 906
		/* 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
907
	ipc.addr = inet->inet_saddr;
908 909

	ipc.oif = sk->sk_bound_dev_if;
910 911 912

	sock_tx_timestamp(sk, &ipc.tx_flags);

913
	if (msg->msg_controllen) {
914
		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
915 916 917 918 919 920
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
921 922 923 924 925 926 927 928 929 930 931 932
	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();
	}
933 934 935 936

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

937
	if (ipc.opt && ipc.opt->opt.srr) {
938 939
		if (!daddr)
			return -EINVAL;
940
		faddr = ipc.opt->opt.faddr;
941 942
		connected = 0;
	}
943
	tos = get_rttos(&ipc, inet);
944 945
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
946
	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
947 948 949 950 951 952 953 954 955 956
		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;
957 958
	} else if (!ipc.oif)
		ipc.oif = inet->uc_index;
959 960

	if (connected)
E
Eric Dumazet 已提交
961
		rt = (struct rtable *)sk_dst_check(sk, 0);
962 963

	if (rt == NULL) {
964 965
		struct net *net = sock_net(sk);

966 967
		fl4 = &fl4_stack;
		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
968 969 970 971
				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
				   inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
				   faddr, saddr, dport, inet->inet_sport);

972 973
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		rt = ip_route_output_flow(net, fl4, sk);
974 975
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
976
			rt = NULL;
977
			if (err == -ENETUNREACH)
978
				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
979 980 981 982 983 984 985 986
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
987
			sk_dst_set(sk, dst_clone(&rt->dst));
988 989 990 991 992 993
	}

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

994
	saddr = fl4->saddr;
995
	if (!ipc.addr)
996
		daddr = ipc.addr = fl4->daddr;
997

H
Herbert Xu 已提交
998 999
	/* Lockless fast path for the non-corking case. */
	if (!corkreq) {
1000
		skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
H
Herbert Xu 已提交
1001 1002 1003
				  sizeof(struct udphdr), &ipc, &rt,
				  msg->msg_flags);
		err = PTR_ERR(skb);
1004
		if (!IS_ERR_OR_NULL(skb))
1005
			err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
1006 1007 1008
		goto out;
	}

1009 1010 1011 1012 1013 1014
	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);

1015
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1016 1017 1018 1019 1020 1021
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
D
David S. Miller 已提交
1022 1023 1024
	fl4 = &inet->cork.fl.u.ip4;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
1025 1026
	fl4->fl4_dport = dport;
	fl4->fl4_sport = inet->inet_sport;
1027 1028 1029 1030
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
1031 1032 1033
	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);
1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055
	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)) {
1056 1057
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
1058 1059 1060 1061
	}
	return err;

do_confirm:
1062
	dst_confirm(&rt->dst);
1063 1064 1065 1066 1067
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1068
EXPORT_SYMBOL(udp_sendmsg);
1069 1070 1071 1072

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
1073
	struct inet_sock *inet = inet_sk(sk);
1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093
	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);

1094
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1095 1096 1097
		return -EINVAL;
	}

1098 1099
	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
			     page, offset, size, flags);
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119
	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
1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138

/**
 *	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)) {
1139 1140
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1141 1142
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1143
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1144 1145 1146 1147 1148 1149 1150
		__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)) {
1151 1152
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1153 1154
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1155
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1156 1157 1158 1159
	}
	return res;
}

L
Linus Torvalds 已提交
1160 1161 1162
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1163

L
Linus Torvalds 已提交
1164 1165
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1166 1167
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1168
	{
1169 1170
		int amount = sk_wmem_alloc_get(sk);

1171 1172
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1173

1174 1175
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1176
		unsigned int amount = first_packet_length(sk);
1177

E
Eric Dumazet 已提交
1178
		if (amount)
1179 1180 1181 1182 1183
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1184 1185
			amount -= sizeof(struct udphdr);

1186 1187
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1188

1189 1190
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1191
	}
1192 1193

	return 0;
L
Linus Torvalds 已提交
1194
}
E
Eric Dumazet 已提交
1195
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1196

1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
/*
 * 	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;
1208
	unsigned int ulen, copied;
1209
	int peeked, off = 0;
1210 1211
	int err;
	int is_udplite = IS_UDPLITE(sk);
1212
	bool slow;
1213 1214 1215 1216 1217

	/*
	 *	Check any passed addresses
	 */
	if (addr_len)
E
Eric Dumazet 已提交
1218
		*addr_len = sizeof(*sin);
1219 1220 1221 1222 1223 1224

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

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1225
				  &peeked, &off, &err);
1226 1227 1228 1229
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
1230 1231 1232 1233
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
1234 1235 1236 1237 1238 1239 1240 1241
		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.
	 */

1242
	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1243 1244 1245 1246 1247 1248
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1249
					      msg->msg_iov, copied);
1250
	else {
E
Eric Dumazet 已提交
1251 1252 1253
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1254 1255 1256 1257 1258

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

1259 1260
	if (unlikely(err)) {
		trace_kfree_skb(skb, udp_recvmsg);
1261 1262 1263 1264 1265
		if (!peeked) {
			atomic_inc(&sk->sk_drops);
			UDP_INC_STATS_USER(sock_net(sk),
					   UDP_MIB_INERRORS, is_udplite);
		}
1266
		goto out_free;
1267
	}
1268 1269

	if (!peeked)
1270 1271
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1272

1273
	sock_recv_ts_and_drops(msg, sk, skb);
1274 1275

	/* Copy the address. */
E
Eric Dumazet 已提交
1276
	if (sin) {
1277 1278 1279 1280 1281 1282 1283 1284
		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);

1285
	err = copied;
1286 1287 1288 1289
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1290
	skb_free_datagram_locked(sk, skb);
1291 1292 1293 1294
out:
	return err;

csum_copy_err:
1295
	slow = lock_sock_fast(sk);
1296 1297
	if (!skb_kill_datagram(sk, skb, flags)) {
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1298
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1299
	}
1300
	unlock_sock_fast(sk, slow);
1301 1302 1303

	if (noblock)
		return -EAGAIN;
1304 1305 1306

	/* starting over for a new packet */
	msg->msg_flags &= ~MSG_TRUNC;
1307 1308 1309 1310
	goto try_again;
}


L
Linus Torvalds 已提交
1311 1312 1313 1314 1315 1316
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1317

L
Linus Torvalds 已提交
1318
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1319 1320
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1321
	sock_rps_reset_rxhash(sk);
L
Linus Torvalds 已提交
1322 1323 1324 1325 1326 1327
	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
1328
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1329 1330 1331 1332
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1333
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1334

1335 1336
void udp_lib_unhash(struct sock *sk)
{
1337 1338
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1339 1340 1341 1342 1343
		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);
1344

1345 1346
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1347
			hslot->count--;
E
Eric Dumazet 已提交
1348
			inet_sk(sk)->inet_num = 0;
1349
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1350 1351 1352 1353 1354

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1355 1356
		}
		spin_unlock_bh(&hslot->lock);
1357 1358 1359 1360
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
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 1401 1402 1403
/*
 * 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
1404 1405
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1406
	int rc;
E
Eric Dumazet 已提交
1407

1408
	if (inet_sk(sk)->inet_daddr) {
1409
		sock_rps_save_rxhash(sk, skb);
1410 1411
		sk_mark_napi_id(sk, skb);
	}
T
Tom Herbert 已提交
1412

1413
	rc = sock_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1414 1415
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1416 1417

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1418
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1419 1420
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1421 1422
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
1423
		trace_udp_fail_queue_rcv_skb(rc, sk);
E
Eric Dumazet 已提交
1424
		return -1;
H
Herbert Xu 已提交
1425 1426 1427 1428 1429 1430
	}

	return 0;

}

1431 1432 1433 1434 1435 1436 1437 1438
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);

1439 1440 1441 1442 1443 1444 1445 1446
/* 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
1447
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
{
	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);

1460
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
1461 1462
		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);

1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474
		/*
		 * 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 */
1475 1476
		encap_rcv = ACCESS_ONCE(up->encap_rcv);
		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1477 1478
			int ret;

1479
			ret = encap_rcv(sk, skb);
1480
			if (ret <= 0) {
1481 1482
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507
						 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  */
1508 1509
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
				       UDP_SKB_CB(skb)->cscov, skb->len);
1510 1511 1512 1513 1514 1515 1516 1517 1518
			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) {
1519 1520
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
1521 1522 1523 1524
			goto drop;
		}
	}

1525 1526
	if (rcu_access_pointer(sk->sk_filter) &&
	    udp_lib_checksum_complete(skb))
1527
		goto csum_error;
1528

1529

1530
	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1531 1532
		goto drop;

H
Herbert Xu 已提交
1533
	rc = 0;
1534

1535
	ipv4_pktinfo_prepare(skb);
H
Herbert Xu 已提交
1536 1537 1538
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
1539
	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
Z
Zhu Yi 已提交
1540 1541 1542
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1543 1544 1545
	bh_unlock_sock(sk);

	return rc;
1546

1547 1548
csum_error:
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1549
drop:
1550
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1551
	atomic_inc(&sk->sk_drops);
1552 1553 1554 1555
	kfree_skb(skb);
	return -1;
}

1556 1557 1558 1559 1560 1561

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;
1562
	struct sock *sk;
1563 1564

	for (i = 0; i < count; i++) {
1565
		sk = stack[i];
1566 1567 1568
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1569 1570 1571 1572 1573 1574 1575 1576 1577
		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)
1578 1579 1580 1581 1582 1583
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1584 1585 1586
/*
 *	Multicasts and broadcasts go to each listener.
 *
1587
 *	Note: called only from the BH handler context.
1588
 */
1589
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1590 1591
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1592
				    struct udp_table *udptable)
1593
{
1594
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1595
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1596
	int dif;
1597
	unsigned int i, count = 0;
1598

1599
	spin_lock(&hslot->lock);
1600
	sk = sk_nulls_head(&hslot->head);
1601
	dif = skb->dev->ifindex;
1602
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619
	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]);

1620
	spin_unlock(&hslot->lock);
1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632

	/*
	 * 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);
	}
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
	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
1660
		if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677
				      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.
 */

1678
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1679 1680 1681
		   int proto)
{
	struct sock *sk;
1682
	struct udphdr *uh;
1683
	unsigned short ulen;
E
Eric Dumazet 已提交
1684
	struct rtable *rt = skb_rtable(skb);
1685
	__be32 saddr, daddr;
1686
	struct net *net = dev_net(skb->dev);
1687 1688 1689 1690 1691 1692 1693

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

1694
	uh   = udp_hdr(skb);
1695
	ulen = ntohs(uh->len);
1696 1697 1698
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712
	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))
1713 1714
		return __udp4_lib_mcast_deliver(net, skb, uh,
				saddr, daddr, udptable);
1715

1716
	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1717 1718

	if (sk != NULL) {
1719 1720 1721
		int ret;

		ret = udp_queue_rcv_skb(sk, skb);
1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
		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;

1740
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
	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:
1751
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1752 1753 1754 1755
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source),
		       ulen, skb->len,
		       &daddr, ntohs(uh->dest));
1756 1757 1758 1759 1760 1761 1762
	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).
	 */
1763
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1764 1765
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1766
		       ulen);
1767
	UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1768
drop:
1769
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1770 1771 1772 1773 1774 1775
	kfree_skb(skb);
	return 0;
}

int udp_rcv(struct sk_buff *skb)
{
1776
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1777 1778
}

1779
void udp_destroy_sock(struct sock *sk)
1780
{
T
Tom Parkin 已提交
1781
	struct udp_sock *up = udp_sk(sk);
1782
	bool slow = lock_sock_fast(sk);
1783
	udp_flush_pending_frames(sk);
1784
	unlock_sock_fast(sk, slow);
T
Tom Parkin 已提交
1785 1786 1787 1788 1789 1790
	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);
	}
1791 1792
}

L
Linus Torvalds 已提交
1793 1794 1795
/*
 *	Socket option code for UDP
 */
1796
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1797
		       char __user *optval, unsigned int optlen,
1798
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1799 1800 1801 1802
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1803
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1804

E
Eric Dumazet 已提交
1805
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1806 1807 1808 1809 1810
		return -EINVAL;

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

1811
	switch (optname) {
L
Linus Torvalds 已提交
1812 1813 1814 1815 1816 1817
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1818
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1819 1820 1821
			release_sock(sk);
		}
		break;
1822

L
Linus Torvalds 已提交
1823 1824 1825 1826 1827
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1828 1829
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
1830
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
1831
			up->encap_type = val;
1832
			udp_encap_enable();
L
Linus Torvalds 已提交
1833 1834 1835 1836 1837 1838 1839
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

1840 1841 1842 1843 1844 1845
	/*
	 * 	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
1846
		if (!is_udplite)         /* Disable the option on UDP sockets */
1847 1848 1849
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
1850 1851
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1852 1853 1854 1855
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

1856 1857
	/* 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
1858 1859
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
1860
		if (!is_udplite)         /* Disable the option on UDP sockets */
1861 1862 1863
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
1864 1865
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1866 1867 1868 1869
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
1870 1871 1872
	default:
		err = -ENOPROTOOPT;
		break;
1873
	}
L
Linus Torvalds 已提交
1874 1875 1876

	return err;
}
E
Eric Dumazet 已提交
1877
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
1878

1879
int udp_setsockopt(struct sock *sk, int level, int optname,
1880
		   char __user *optval, unsigned int optlen)
1881 1882 1883 1884 1885 1886 1887 1888 1889
{
	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,
1890
			  char __user *optval, unsigned int optlen)
1891 1892 1893 1894 1895 1896 1897 1898
{
	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

1899 1900
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
1901 1902 1903 1904
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
1905
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
1906 1907 1908
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
1909

1910
	if (len < 0)
L
Linus Torvalds 已提交
1911 1912
		return -EINVAL;

1913
	switch (optname) {
L
Linus Torvalds 已提交
1914 1915 1916 1917 1918 1919 1920 1921
	case UDP_CORK:
		val = up->corkflag;
		break;

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

1922 1923 1924 1925 1926 1927 1928 1929 1930 1931
	/* 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
1932 1933
	default:
		return -ENOPROTOOPT;
1934
	}
L
Linus Torvalds 已提交
1935

1936
	if (put_user(len, optlen))
1937
		return -EFAULT;
E
Eric Dumazet 已提交
1938
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
1939
		return -EFAULT;
1940
	return 0;
L
Linus Torvalds 已提交
1941
}
E
Eric Dumazet 已提交
1942
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
1943

1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960
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
1961 1962 1963 1964 1965 1966
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
1967
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
1968 1969 1970 1971 1972 1973 1974 1975 1976 1977
 *	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;
1978

1979 1980
	sock_rps_record_flow(sk);

L
Linus Torvalds 已提交
1981
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
1982 1983 1984
	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
1985 1986

	return mask;
1987

L
Linus Torvalds 已提交
1988
}
E
Eric Dumazet 已提交
1989
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
1990

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
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
2004
	.backlog_rcv	   = __udp_queue_rcv_skb,
2005
	.release_cb	   = ip4_datagram_release_cb,
2006 2007
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
2008
	.rehash		   = udp_v4_rehash,
2009 2010 2011 2012 2013 2014
	.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),
2015
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
2016
	.h.udp_table	   = &udp_table,
2017 2018 2019 2020
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
2021
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
2022
};
E
Eric Dumazet 已提交
2023
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
2024 2025 2026 2027

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

2028
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
2029 2030 2031
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
2032
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2033

2034 2035
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
2036
		struct hlist_nulls_node *node;
2037
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2038 2039 2040 2041

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

2042
		spin_lock_bh(&hslot->lock);
2043
		sk_nulls_for_each(sk, node, &hslot->head) {
2044
			if (!net_eq(sock_net(sk), net))
2045
				continue;
L
Linus Torvalds 已提交
2046 2047 2048
			if (sk->sk_family == state->family)
				goto found;
		}
2049
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058
	}
	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;
2059
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
2060 2061

	do {
2062
		sk = sk_nulls_next(sk);
2063
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
2064

2065
	if (!sk) {
2066
		if (state->bucket <= state->udp_table->mask)
2067
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2068
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
2069 2070 2071 2072 2073 2074
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
2075
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
2076 2077

	if (sk)
2078
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
2079 2080 2081 2082 2083 2084
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
2085
	struct udp_iter_state *state = seq->private;
2086
	state->bucket = MAX_UDP_PORTS;
2087

2088
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
2089 2090 2091 2092 2093 2094
}

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

2095
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
		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)
{
2106 2107
	struct udp_iter_state *state = seq->private;

2108
	if (state->bucket <= state->udp_table->mask)
2109
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2110 2111
}

2112
int udp_seq_open(struct inode *inode, struct file *file)
L
Linus Torvalds 已提交
2113
{
A
Al Viro 已提交
2114
	struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2115 2116
	struct udp_iter_state *s;
	int err;
2117

2118 2119 2120 2121
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2122

2123
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2124
	s->family		= afinfo->family;
2125
	s->udp_table		= afinfo->udp_table;
2126
	return err;
2127
}
2128
EXPORT_SYMBOL(udp_seq_open);
2129

L
Linus Torvalds 已提交
2130
/* ------------------------------------------------------------------------ */
2131
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2132 2133 2134 2135
{
	struct proc_dir_entry *p;
	int rc = 0;

2136 2137 2138 2139
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2140
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2141
			     afinfo->seq_fops, afinfo);
2142
	if (!p)
L
Linus Torvalds 已提交
2143 2144 2145
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2146
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2147

2148
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2149
{
2150
	remove_proc_entry(afinfo->name, net->proc_net);
L
Linus Torvalds 已提交
2151
}
E
Eric Dumazet 已提交
2152
EXPORT_SYMBOL(udp_proc_unregister);
2153 2154

/* ------------------------------------------------------------------------ */
2155 2156
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
		int bucket, int *len)
2157 2158
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2159 2160 2161 2162
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2163

2164
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2165
		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d%n",
2166
		bucket, src, srcp, dest, destp, sp->sk_state,
2167 2168
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2169 2170 2171
		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
2172 2173
		atomic_read(&sp->sk_refcnt), sp,
		atomic_read(&sp->sk_drops), len);
2174 2175 2176 2177 2178 2179 2180 2181
}

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
2182
			   "inode ref pointer drops");
2183 2184
	else {
		struct udp_iter_state *state = seq->private;
2185
		int len;
2186

2187
		udp4_format_sock(v, seq, state->bucket, &len);
E
Eric Dumazet 已提交
2188
		seq_printf(seq, "%*s\n", 127 - len, "");
2189 2190 2191 2192
	}
	return 0;
}

2193 2194 2195 2196 2197 2198 2199 2200
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
};

2201 2202 2203 2204
/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2205
	.udp_table	= &udp_table,
2206
	.seq_fops	= &udp_afinfo_seq_fops,
2207 2208 2209
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2210 2211
};

2212
static int __net_init udp4_proc_init_net(struct net *net)
2213 2214 2215 2216
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2217
static void __net_exit udp4_proc_exit_net(struct net *net)
2218 2219 2220 2221 2222 2223 2224 2225 2226
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2227 2228
int __init udp4_proc_init(void)
{
2229
	return register_pernet_subsys(&udp4_net_ops);
2230 2231 2232 2233
}

void udp4_proc_exit(void)
{
2234
	unregister_pernet_subsys(&udp4_net_ops);
2235
}
L
Linus Torvalds 已提交
2236 2237
#endif /* CONFIG_PROC_FS */

2238 2239
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2240
{
2241 2242
	ssize_t ret;

2243 2244
	if (!str)
		return 0;
2245 2246 2247 2248 2249

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

2250 2251 2252 2253 2254
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2255

2256 2257 2258 2259
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

2260 2261 2262 2263 2264 2265 2266 2267 2268 2269
	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);

2270
	table->hash2 = table->hash + (table->mask + 1);
2271
	for (i = 0; i <= table->mask; i++) {
2272
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2273
		table->hash[i].count = 0;
2274 2275
		spin_lock_init(&table->hash[i].lock);
	}
2276 2277 2278 2279 2280
	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);
	}
2281 2282
}

H
Hideo Aoki 已提交
2283 2284
void __init udp_init(void)
{
2285
	unsigned long limit;
H
Hideo Aoki 已提交
2286

2287
	udp_table_init(&udp_table, "UDP");
2288
	limit = nr_free_buffer_pages() / 8;
H
Hideo Aoki 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297
	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;
}

2298 2299
struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
				       netdev_features_t features)
2300 2301 2302 2303
{
	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
2304
	__be16 protocol = skb->protocol;
2305
	netdev_features_t enc_features;
P
Pravin B Shelar 已提交
2306
	int outer_hlen;
2307 2308 2309 2310 2311 2312 2313 2314 2315

	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);
2316
	skb->protocol = htons(ETH_P_TEB);
2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329

	/* 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;

2330 2331 2332
		skb_reset_inner_headers(skb);
		skb->encapsulation = 1;

2333 2334 2335 2336 2337 2338 2339 2340 2341 2342
		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. */
2343
		if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) {
2344 2345 2346 2347 2348 2349 2350 2351 2352 2353
			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;

2354 2355 2356 2357 2358 2359 2360 2361 2362 2363
		} else if (protocol == htons(ETH_P_IPV6)) {
			struct ipv6hdr *ipv6h = ipv6_hdr(skb);
			u32 len = skb->len - udp_offset;

			uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
						     len, IPPROTO_UDP, 0);
			uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0));
			if (uh->check == 0)
				uh->check = CSUM_MANGLED_0;
			skb->ip_summed = CHECKSUM_NONE;
2364
		}
2365

P
Pravin B Shelar 已提交
2366
		skb->protocol = protocol;
2367 2368 2369 2370
	} while ((skb = skb->next));
out:
	return segs;
}