udp.c 55.0 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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#include <asm/system.h>
#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 <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 "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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int sysctl_udp_mem[3] __read_mostly;
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);

atomic_t udp_memory_allocated;
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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	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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		    (*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;
	int res = 0;

	spin_lock(&hslot2->lock);
	udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
		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) &&
		    (*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-dependant hash value in secondary hash chains,
 *                   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;
		unsigned 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);
		for (last = first + udptable->mask + 1;
		     first != last;
		     first++) {
			hslot = udp_hashslot(udptable, net, first);
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			bitmap_zero(bitmap, PORTS_PER_CHAIN);
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			spin_lock_bh(&hslot->lock);
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			udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
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					    saddr_comp, udptable->log);
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			snum = first;
			/*
			 * Iterate on all possible values of snum for this hash.
			 * Using steps of an odd multiple of UDP_HTABLE_SIZE
			 * give us randomization and full range coverage.
			 */
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			do {
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				if (low <= snum && snum <= high &&
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				    !test_bit(snum >> udptable->log, bitmap))
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					goto found;
				snum += rand;
			} while (snum != first);
			spin_unlock_bh(&hslot->lock);
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		}
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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)
{
	return jhash_1word(saddr, net_hash_mix(net)) ^ port;
}

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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 =
		udp4_portaddr_hash(sock_net(sk), INADDR_ANY, snum);
	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);

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

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/*
 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
 */
#define SCORE2_MAX (1 + 2 + 2 + 2)
static inline int compute_score2(struct sock *sk, struct net *net,
				 __be32 saddr, __be16 sport,
				 __be32 daddr, unsigned int hnum, int dif)
{
	int score = -1;

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

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

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


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

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

	if (result) {
exact_match:
		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
			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
 */
static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
		__be16 sport, __be32 daddr, __be16 dport,
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		int dif, struct udp_table *udptable)
449
{
450
	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;
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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) {
			hash2 = udp4_portaddr_hash(net, INADDR_ANY, hnum);
			slot2 = hash2 & udptable->mask;
			hslot2 = &udptable->hash2[slot2];
			if (hslot->count < hslot2->count)
				goto begin;

			result = udp4_lib_lookup2(net, INADDR_ANY, sport,
						  daddr, hnum, dif,
						  hslot2, slot2);
		}
		rcu_read_unlock();
		return result;
	}
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begin:
	result = NULL;
	badness = -1;
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	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
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		score = compute_score(sk, net, saddr, hnum, sport,
				      daddr, dport, dif);
		if (score > badness) {
			result = sk;
			badness = score;
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		}
	}
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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.
	 */
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	if (get_nulls_value(node) != slot)
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		goto begin;

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	if (result) {
		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
			result = NULL;
		else if (unlikely(compute_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
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	return result;
}

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

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	if (unlikely(sk = skb_steal_sock(skb)))
		return sk;
	else
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		return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
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					 iph->daddr, dport, inet_iif(skb),
					 udptable);
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}

529 530 531
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
532
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
533 534 535
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

536
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
537 538 539 540
					     __be16 loc_port, __be32 loc_addr,
					     __be16 rmt_port, __be32 rmt_addr,
					     int dif)
{
541
	struct hlist_nulls_node *node;
542 543 544
	struct sock *s = sk;
	unsigned short hnum = ntohs(loc_port);

545
	sk_nulls_for_each_from(s, node) {
546 547
		struct inet_sock *inet = inet_sk(s);

548
		if (!net_eq(sock_net(s), net)				||
549
		    udp_sk(s)->udp_port_hash != hnum			||
E
Eric Dumazet 已提交
550 551 552 553
		    (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)			||
554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
		    ipv6_only_sock(s)					||
		    (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.
 */

577
void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
578 579
{
	struct inet_sock *inet;
E
Eric Dumazet 已提交
580 581
	struct iphdr *iph = (struct iphdr *)skb->data;
	struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
582 583 584 585 586
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	int harderr;
	int err;
587
	struct net *net = dev_net(skb->dev);
588

589
	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
590 591
			iph->saddr, uh->source, skb->dev->ifindex, udptable);
	if (sk == NULL) {
592
		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635
		return;	/* No socket for error */
	}

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

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

	/*
	 *      RFC1122: OK.  Passes ICMP errors back to application, as per
	 *	4.1.3.3.
	 */
	if (!inet->recverr) {
		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
			goto out;
	} else {
E
Eric Dumazet 已提交
636
		ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
637 638 639 640 641 642 643 644 645
	}
	sk->sk_err = err;
	sk->sk_error_report(sk);
out:
	sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
646
	__udp4_lib_err(skb, info, &udp_table);
647 648 649 650 651
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
652
void udp_flush_pending_frames(struct sock *sk)
653 654 655 656 657 658 659 660 661
{
	struct udp_sock *up = udp_sk(sk);

	if (up->pending) {
		up->len = 0;
		up->pending = 0;
		ip_flush_pending_frames(sk);
	}
}
662
EXPORT_SYMBOL(udp_flush_pending_frames);
663 664 665 666 667 668 669 670

/**
 * 	udp4_hwcsum_outgoing  -  handle outgoing HW checksumming
 * 	@sk: 	socket we are sending on
 * 	@skb: 	sk_buff containing the filled-in UDP header
 * 	        (checksum field must be zeroed out)
 */
static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
E
Eric Dumazet 已提交
671
				 __be32 src, __be32 dst, int len)
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741
{
	unsigned int offset;
	struct udphdr *uh = udp_hdr(skb);
	__wsum csum = 0;

	if (skb_queue_len(&sk->sk_write_queue) == 1) {
		/*
		 * Only one fragment on the socket.
		 */
		skb->csum_start = skb_transport_header(skb) - skb->head;
		skb->csum_offset = offsetof(struct udphdr, check);
		uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
	} 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
		 */
		offset = skb_transport_offset(skb);
		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);

		skb->ip_summed = CHECKSUM_NONE;

		skb_queue_walk(&sk->sk_write_queue, skb) {
			csum = csum_add(csum, skb->csum);
		}

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

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

	/* Grab the skbuff where UDP header space exists. */
	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
		goto out;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
	uh->source = fl->fl_ip_sport;
	uh->dest = fl->fl_ip_dport;
	uh->len = htons(up->len);
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
		csum  = udplite_csum_outgoing(sk, skb);

	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 */

E
Eric Dumazet 已提交
742
		udp4_hwcsum_outgoing(sk, skb, fl->fl4_src, fl->fl4_dst, up->len);
743 744 745 746 747 748 749
		goto send;

	} else						 /*   `normal' UDP    */
		csum = udp_csum_outgoing(sk, skb);

	/* add protocol-dependent pseudo-header */
	uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
E
Eric Dumazet 已提交
750
				      sk->sk_protocol, csum);
751 752 753 754 755
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
	err = ip_push_pending_frames(sk);
E
Eric Dumazet 已提交
756 757 758 759 760 761 762 763 764
	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);
765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794
out:
	up->len = 0;
	up->pending = 0;
	return err;
}

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

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
795
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
796 797 798
		return -EOPNOTSUPP;

	ipc.opt = NULL;
799
	ipc.shtx.flags = 0;
800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821

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

	/*
	 *	Get and verify the address.
	 */
	if (msg->msg_name) {
E
Eric Dumazet 已提交
822
		struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name;
823 824 825 826 827 828 829 830 831 832 833 834 835 836
		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
837 838
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
839 840 841 842 843
		/* 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
844
	ipc.addr = inet->inet_saddr;
845 846

	ipc.oif = sk->sk_bound_dev_if;
847 848 849
	err = sock_tx_timestamp(msg, sk, &ipc.shtx);
	if (err)
		return err;
850
	if (msg->msg_controllen) {
851
		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
	if (!ipc.opt)
		ipc.opt = inet->opt;

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

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

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

	if (connected)
E
Eric Dumazet 已提交
887
		rt = (struct rtable *)sk_dst_check(sk, 0);
888 889 890

	if (rt == NULL) {
		struct flowi fl = { .oif = ipc.oif,
891
				    .mark = sk->sk_mark,
892 893 894 895 896
				    .nl_u = { .ip4_u =
					      { .daddr = faddr,
						.saddr = saddr,
						.tos = tos } },
				    .proto = sk->sk_protocol,
897
				    .flags = inet_sk_flowi_flags(sk),
898
				    .uli_u = { .ports =
E
Eric Dumazet 已提交
899
					       { .sport = inet->inet_sport,
900
						 .dport = dport } } };
901 902
		struct net *net = sock_net(sk);

903
		security_sk_classify_flow(sk, &fl);
904
		err = ip_route_output_flow(net, &rt, &fl, sk, 1);
905 906
		if (err) {
			if (err == -ENETUNREACH)
907
				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
			sk_dst_set(sk, dst_clone(&rt->u.dst));
	}

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

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

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

		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
	inet->cork.fl.fl4_dst = daddr;
	inet->cork.fl.fl_ip_dport = dport;
	inet->cork.fl.fl4_src = saddr;
E
Eric Dumazet 已提交
943
	inet->cork.fl.fl_ip_sport = inet->inet_sport;
944 945 946 947 948 949
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
	err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
950
			sizeof(struct udphdr), &ipc, &rt,
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973
			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
	if (err)
		udp_flush_pending_frames(sk);
	else if (!corkreq)
		err = udp_push_pending_frames(sk);
	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
		up->pending = 0;
	release_sock(sk);

out:
	ip_rt_put(rt);
	if (free)
		kfree(ipc.opt);
	if (!err)
		return len;
	/*
	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
	 * we don't have a good statistic (IpOutDiscards but it can be too many
	 * things).  We could add another new stat but at least for now that
	 * seems like overkill.
	 */
	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
974 975
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
976 977 978 979 980 981 982 983 984 985
	}
	return err;

do_confirm:
	dst_confirm(&rt->u.dst);
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
986
EXPORT_SYMBOL(udp_sendmsg);
987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035

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

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

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

	lock_sock(sk);

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

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

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

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

E
Eric Dumazet 已提交
1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056

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

	__skb_queue_head_init(&list_kill);

	spin_lock_bh(&rcvq->lock);
	while ((skb = skb_peek(rcvq)) != NULL &&
		udp_lib_checksum_complete(skb)) {
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
				 IS_UDPLITE(sk));
E
Eric Dumazet 已提交
1057
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
		__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)) {
		lock_sock(sk);
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
		release_sock(sk);
	}
	return res;
}

L
Linus Torvalds 已提交
1073 1074 1075
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1076

L
Linus Torvalds 已提交
1077 1078
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1079 1080
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1081
	{
1082 1083
		int amount = sk_wmem_alloc_get(sk);

1084 1085
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1086

1087 1088
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1089
		unsigned int amount = first_packet_length(sk);
1090

E
Eric Dumazet 已提交
1091
		if (amount)
1092 1093 1094 1095 1096
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1097 1098
			amount -= sizeof(struct udphdr);

1099 1100
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1101

1102 1103
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1104
	}
1105 1106

	return 0;
L
Linus Torvalds 已提交
1107
}
E
Eric Dumazet 已提交
1108
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1109

1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129
/*
 * 	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;
	unsigned int ulen, copied;
	int peeked;
	int err;
	int is_udplite = IS_UDPLITE(sk);

	/*
	 *	Check any passed addresses
	 */
	if (addr_len)
E
Eric Dumazet 已提交
1130
		*addr_len = sizeof(*sin);
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160

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

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

	ulen = skb->len - sizeof(struct udphdr);
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
		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.
	 */

	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
E
Eric Dumazet 已提交
1161
					      msg->msg_iov, copied);
1162
	else {
E
Eric Dumazet 已提交
1163 1164 1165
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1166 1167 1168 1169 1170 1171 1172 1173 1174

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

	if (err)
		goto out_free;

	if (!peeked)
1175 1176
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1177

1178
	sock_recv_ts_and_drops(msg, sk, skb);
1179 1180

	/* Copy the address. */
E
Eric Dumazet 已提交
1181
	if (sin) {
1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194
		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);

	err = copied;
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1195
	skb_free_datagram_locked(sk, skb);
1196 1197 1198 1199 1200 1201
out:
	return err;

csum_copy_err:
	lock_sock(sk);
	if (!skb_kill_datagram(sk, skb, flags))
1202
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1203 1204 1205 1206 1207 1208 1209 1210
	release_sock(sk);

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


L
Linus Torvalds 已提交
1211 1212 1213 1214 1215 1216
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1217

L
Linus Torvalds 已提交
1218
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1219 1220
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
1221 1222 1223 1224 1225 1226
	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
1227
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1228 1229 1230 1231
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1232
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1233

1234 1235
void udp_lib_unhash(struct sock *sk)
{
1236 1237
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1238 1239 1240 1241 1242
		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);
1243

1244 1245
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1246
			hslot->count--;
E
Eric Dumazet 已提交
1247
			inet_sk(sk)->inet_num = 0;
1248
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1249 1250 1251 1252 1253

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1254 1255
		}
		spin_unlock_bh(&hslot->lock);
1256 1257 1258 1259
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

H
Herbert Xu 已提交
1260 1261
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
1262 1263 1264 1265
	int rc = sock_queue_rcv_skb(sk, skb);

	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1266 1267

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1268
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1269 1270
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1271 1272 1273
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
		return -1;
H
Herbert Xu 已提交
1274 1275 1276 1277 1278 1279
	}

	return 0;

}

1280 1281 1282 1283 1284 1285 1286 1287
/* 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
1288
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319
{
	struct udp_sock *up = udp_sk(sk);
	int rc;
	int is_udplite = IS_UDPLITE(sk);

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

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

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

			ret = (*up->encap_rcv)(sk, skb);
			if (ret <= 0) {
1320 1321
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370
						 is_udplite);
				return -ret;
			}
		}

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

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

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

	if (sk->sk_filter) {
		if (udp_lib_checksum_complete(skb))
			goto drop;
	}

H
Herbert Xu 已提交
1371
	rc = 0;
1372

H
Herbert Xu 已提交
1373 1374 1375 1376 1377 1378 1379 1380
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
	else
		sk_add_backlog(sk, skb);
	bh_unlock_sock(sk);

	return rc;
1381 1382

drop:
1383
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1384
	atomic_inc(&sk->sk_drops);
1385 1386 1387 1388
	kfree_skb(skb);
	return -1;
}

1389 1390 1391 1392 1393 1394

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;
1395
	struct sock *sk;
1396 1397

	for (i = 0; i < count; i++) {
1398
		sk = stack[i];
1399 1400 1401
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1402 1403 1404 1405 1406 1407 1408 1409 1410
		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)
1411 1412 1413 1414 1415 1416
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1417 1418 1419
/*
 *	Multicasts and broadcasts go to each listener.
 *
1420
 *	Note: called only from the BH handler context.
1421
 */
1422
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1423 1424
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1425
				    struct udp_table *udptable)
1426
{
1427
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1428
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1429
	int dif;
1430
	unsigned int i, count = 0;
1431

1432
	spin_lock(&hslot->lock);
1433
	sk = sk_nulls_head(&hslot->head);
1434
	dif = skb->dev->ifindex;
1435
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
	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]);

1453
	spin_unlock(&hslot->lock);
1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465

	/*
	 * 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);
	}
1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
	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
1493
		if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
				      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.
 */

1511
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1512 1513 1514
		   int proto)
{
	struct sock *sk;
1515
	struct udphdr *uh;
1516
	unsigned short ulen;
E
Eric Dumazet 已提交
1517
	struct rtable *rt = skb_rtable(skb);
1518
	__be32 saddr, daddr;
1519
	struct net *net = dev_net(skb->dev);
1520 1521 1522 1523 1524 1525 1526

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

1527
	uh   = udp_hdr(skb);
1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
	ulen = ntohs(uh->len);
	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;

1542 1543 1544
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1545
	if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1546 1547
		return __udp4_lib_mcast_deliver(net, skb, uh,
				saddr, daddr, udptable);
1548

1549
	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1550 1551

	if (sk != NULL) {
H
Herbert Xu 已提交
1552
		int ret = udp_queue_rcv_skb(sk, skb);
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570
		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;

1571
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1572 1573 1574 1575 1576 1577 1578 1579 1580 1581
	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:
1582
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1583
		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
1584
		       &saddr,
1585 1586 1587
		       ntohs(uh->source),
		       ulen,
		       skb->len,
1588
		       &daddr,
1589 1590 1591 1592 1593 1594 1595 1596
		       ntohs(uh->dest));
	goto drop;

csum_error:
	/*
	 * RFC1122: OK.  Discards the bad packet silently (as far as
	 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
	 */
1597
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1598
		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
1599
		       &saddr,
1600
		       ntohs(uh->source),
1601
		       &daddr,
1602 1603 1604
		       ntohs(uh->dest),
		       ulen);
drop:
1605
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1606 1607 1608 1609 1610 1611
	kfree_skb(skb);
	return 0;
}

int udp_rcv(struct sk_buff *skb)
{
1612
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1613 1614
}

1615
void udp_destroy_sock(struct sock *sk)
1616 1617 1618 1619 1620 1621
{
	lock_sock(sk);
	udp_flush_pending_frames(sk);
	release_sock(sk);
}

L
Linus Torvalds 已提交
1622 1623 1624
/*
 *	Socket option code for UDP
 */
1625
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1626
		       char __user *optval, unsigned int optlen,
1627
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1628 1629 1630 1631
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1632
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1633

E
Eric Dumazet 已提交
1634
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1635 1636 1637 1638 1639
		return -EINVAL;

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

1640
	switch (optname) {
L
Linus Torvalds 已提交
1641 1642 1643 1644 1645 1646
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1647
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1648 1649 1650
			release_sock(sk);
		}
		break;
1651

L
Linus Torvalds 已提交
1652 1653 1654 1655 1656
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1657 1658
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
1659
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
1660 1661 1662 1663 1664 1665 1666 1667
			up->encap_type = val;
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

1668 1669 1670 1671 1672 1673
	/*
	 * 	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
1674
		if (!is_udplite)         /* Disable the option on UDP sockets */
1675 1676 1677
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
1678 1679
		else if (val > USHORT_MAX)
			val = USHORT_MAX;
1680 1681 1682 1683
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

1684 1685
	/* 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
1686 1687
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
1688
		if (!is_udplite)         /* Disable the option on UDP sockets */
1689 1690 1691
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
1692 1693
		else if (val > USHORT_MAX)
			val = USHORT_MAX;
1694 1695 1696 1697
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
1698 1699 1700
	default:
		err = -ENOPROTOOPT;
		break;
1701
	}
L
Linus Torvalds 已提交
1702 1703 1704

	return err;
}
E
Eric Dumazet 已提交
1705
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
1706

1707
int udp_setsockopt(struct sock *sk, int level, int optname,
1708
		   char __user *optval, unsigned int optlen)
1709 1710 1711 1712 1713 1714 1715 1716 1717
{
	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,
1718
			  char __user *optval, unsigned int optlen)
1719 1720 1721 1722 1723 1724 1725 1726
{
	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

1727 1728
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
1729 1730 1731 1732
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
1733
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
1734 1735 1736
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
1737

1738
	if (len < 0)
L
Linus Torvalds 已提交
1739 1740
		return -EINVAL;

1741
	switch (optname) {
L
Linus Torvalds 已提交
1742 1743 1744 1745 1746 1747 1748 1749
	case UDP_CORK:
		val = up->corkflag;
		break;

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

1750 1751 1752 1753 1754 1755 1756 1757 1758 1759
	/* 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
1760 1761
	default:
		return -ENOPROTOOPT;
1762
	}
L
Linus Torvalds 已提交
1763

1764
	if (put_user(len, optlen))
1765
		return -EFAULT;
E
Eric Dumazet 已提交
1766
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
1767
		return -EFAULT;
1768
	return 0;
L
Linus Torvalds 已提交
1769
}
E
Eric Dumazet 已提交
1770
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
1771

1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788
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
1789 1790 1791 1792 1793 1794
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
1795
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
1796 1797 1798 1799 1800 1801 1802 1803 1804 1805
 *	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;
1806

L
Linus Torvalds 已提交
1807
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
1808 1809 1810
	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
1811 1812

	return mask;
1813

L
Linus Torvalds 已提交
1814
}
E
Eric Dumazet 已提交
1815
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
1816

1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829
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
1830
	.backlog_rcv	   = __udp_queue_rcv_skb,
1831 1832 1833 1834 1835 1836 1837 1838
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
	.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),
1839
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1840
	.h.udp_table	   = &udp_table,
1841 1842 1843 1844 1845
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
};
E
Eric Dumazet 已提交
1846
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
1847 1848 1849 1850

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

1851
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
1852 1853 1854
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
1855
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1856

1857 1858
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
1859
		struct hlist_nulls_node *node;
1860
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1861 1862 1863 1864

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

1865
		spin_lock_bh(&hslot->lock);
1866
		sk_nulls_for_each(sk, node, &hslot->head) {
1867
			if (!net_eq(sock_net(sk), net))
1868
				continue;
L
Linus Torvalds 已提交
1869 1870 1871
			if (sk->sk_family == state->family)
				goto found;
		}
1872
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
1873 1874 1875 1876 1877 1878 1879 1880 1881
	}
	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;
1882
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1883 1884

	do {
1885
		sk = sk_nulls_next(sk);
1886
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
1887

1888
	if (!sk) {
1889
		if (state->bucket <= state->udp_table->mask)
1890
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
1891
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
1892 1893 1894 1895 1896 1897
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
1898
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
1899 1900

	if (sk)
1901
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
1902 1903 1904 1905 1906 1907
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
1908
	struct udp_iter_state *state = seq->private;
1909
	state->bucket = MAX_UDP_PORTS;
1910

1911
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
1912 1913 1914 1915 1916 1917
}

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

1918
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
1919 1920 1921 1922 1923 1924 1925 1926 1927 1928
		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)
{
1929 1930
	struct udp_iter_state *state = seq->private;

1931
	if (state->bucket <= state->udp_table->mask)
1932
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
1933 1934 1935 1936 1937
}

static int udp_seq_open(struct inode *inode, struct file *file)
{
	struct udp_seq_afinfo *afinfo = PDE(inode)->data;
1938 1939
	struct udp_iter_state *s;
	int err;
1940

1941 1942 1943 1944
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
1945

1946
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
1947
	s->family		= afinfo->family;
1948
	s->udp_table		= afinfo->udp_table;
1949
	return err;
1950 1951
}

L
Linus Torvalds 已提交
1952
/* ------------------------------------------------------------------------ */
1953
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
1954 1955 1956 1957
{
	struct proc_dir_entry *p;
	int rc = 0;

1958 1959 1960 1961
	afinfo->seq_fops.open		= udp_seq_open;
	afinfo->seq_fops.read		= seq_read;
	afinfo->seq_fops.llseek		= seq_lseek;
	afinfo->seq_fops.release	= seq_release_net;
L
Linus Torvalds 已提交
1962

1963 1964 1965 1966
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

1967 1968 1969
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
			     &afinfo->seq_fops, afinfo);
	if (!p)
L
Linus Torvalds 已提交
1970 1971 1972
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
1973
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
1974

1975
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
1976
{
1977
	proc_net_remove(net, afinfo->name);
L
Linus Torvalds 已提交
1978
}
E
Eric Dumazet 已提交
1979
EXPORT_SYMBOL(udp_proc_unregister);
1980 1981

/* ------------------------------------------------------------------------ */
1982 1983
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
		int bucket, int *len)
1984 1985
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
1986 1987 1988 1989
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
1990

1991
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
E
Eric Dumazet 已提交
1992
		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
1993
		bucket, src, srcp, dest, destp, sp->sk_state,
1994 1995
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
1996
		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
E
Eric Dumazet 已提交
1997 1998
		atomic_read(&sp->sk_refcnt), sp,
		atomic_read(&sp->sk_drops), len);
1999 2000 2001 2002 2003 2004 2005 2006
}

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
2007
			   "inode ref pointer drops");
2008 2009
	else {
		struct udp_iter_state *state = seq->private;
2010
		int len;
2011

2012
		udp4_format_sock(v, seq, state->bucket, &len);
E
Eric Dumazet 已提交
2013
		seq_printf(seq, "%*s\n", 127 - len, "");
2014 2015 2016 2017 2018 2019 2020 2021
	}
	return 0;
}

/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2022
	.udp_table	= &udp_table,
2023 2024 2025
	.seq_fops	= {
		.owner	=	THIS_MODULE,
	},
2026 2027 2028
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2029 2030
};

2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045
static int udp4_proc_init_net(struct net *net)
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

static void udp4_proc_exit_net(struct net *net)
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2046 2047
int __init udp4_proc_init(void)
{
2048
	return register_pernet_subsys(&udp4_net_ops);
2049 2050 2051 2052
}

void udp4_proc_exit(void)
{
2053
	unregister_pernet_subsys(&udp4_net_ops);
2054
}
L
Linus Torvalds 已提交
2055 2056
#endif /* CONFIG_PROC_FS */

2057 2058
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2059
{
2060 2061 2062 2063 2064 2065 2066 2067
	if (!str)
		return 0;
	uhash_entries = simple_strtoul(str, &str, 0);
	if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
		uhash_entries = UDP_HTABLE_SIZE_MIN;
	return 1;
}
__setup("uhash_entries=", set_uhash_entries);
2068

2069 2070 2071 2072 2073 2074
void __init udp_table_init(struct udp_table *table, const char *name)
{
	unsigned int i;

	if (!CONFIG_BASE_SMALL)
		table->hash = alloc_large_system_hash(name,
2075
			2 * sizeof(struct udp_hslot),
2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086
			uhash_entries,
			21, /* one slot per 2 MB */
			0,
			&table->log,
			&table->mask,
			64 * 1024);
	/*
	 * Make sure hash table has the minimum size
	 */
	if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) {
		table->hash = kmalloc(UDP_HTABLE_SIZE_MIN *
2087
				      2 * sizeof(struct udp_hslot), GFP_KERNEL);
2088 2089 2090 2091 2092
		if (!table->hash)
			panic(name);
		table->log = ilog2(UDP_HTABLE_SIZE_MIN);
		table->mask = UDP_HTABLE_SIZE_MIN - 1;
	}
2093
	table->hash2 = table->hash + (table->mask + 1);
2094
	for (i = 0; i <= table->mask; i++) {
2095
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2096
		table->hash[i].count = 0;
2097 2098
		spin_lock_init(&table->hash[i].lock);
	}
2099 2100 2101 2102 2103
	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);
	}
2104 2105
}

H
Hideo Aoki 已提交
2106 2107
void __init udp_init(void)
{
2108
	unsigned long nr_pages, limit;
H
Hideo Aoki 已提交
2109

2110
	udp_table_init(&udp_table, "UDP");
H
Hideo Aoki 已提交
2111 2112 2113 2114
	/* Set the pressure threshold up by the same strategy of TCP. It is a
	 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
	 * toward zero with the amount of memory, with a floor of 128 pages.
	 */
2115 2116 2117
	nr_pages = totalram_pages - totalhigh_pages;
	limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
	limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
H
Hideo Aoki 已提交
2118 2119 2120 2121 2122 2123 2124 2125 2126
	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;
}

2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174
int udp4_ufo_send_check(struct sk_buff *skb)
{
	const struct iphdr *iph;
	struct udphdr *uh;

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

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

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

struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	unsigned int mss;
	int offset;
	__wsum csum;

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

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

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

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

		segs = NULL;
		goto out;
	}

	/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
	 * do checksum of UDP packets sent as multiple IP fragments.
	 */
	offset = skb->csum_start - skb_headroom(skb);
E
Eric Dumazet 已提交
2175
	csum = skb_checksum(skb, offset, skb->len - offset, 0);
2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187
	offset += skb->csum_offset;
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
	skb->ip_summed = CHECKSUM_NONE;

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