udp.c 57.7 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 "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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	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)
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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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		    (*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;
		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);
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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);

		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:
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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)
453
{
454
	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) {
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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;

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			result = udp4_lib_lookup2(net, saddr, sport,
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						  htonl(INADDR_ANY), hnum, dif,
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						  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) {
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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_score(result, net, saddr, hnum, sport,
				  daddr, dport, dif) < badness)) {
			sock_put(result);
			goto begin;
		}
	}
	rcu_read_unlock();
515 516
	return result;
}
517
EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
518

519 520
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
						 __be16 sport, __be16 dport,
521
						 struct udp_table *udptable)
522
{
523
	struct sock *sk;
524 525
	const struct iphdr *iph = ip_hdr(skb);

526 527 528
	if (unlikely(sk = skb_steal_sock(skb)))
		return sk;
	else
E
Eric Dumazet 已提交
529
		return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
530 531
					 iph->daddr, dport, inet_iif(skb),
					 udptable);
532 533
}

534 535 536
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
			     __be32 daddr, __be16 dport, int dif)
{
537
	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
538 539 540
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);

541
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
542 543 544 545
					     __be16 loc_port, __be32 loc_addr,
					     __be16 rmt_port, __be32 rmt_addr,
					     int dif)
{
546
	struct hlist_nulls_node *node;
547 548 549
	struct sock *s = sk;
	unsigned short hnum = ntohs(loc_port);

550
	sk_nulls_for_each_from(s, node) {
551 552
		struct inet_sock *inet = inet_sk(s);

553 554 555 556 557 558 559
		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) ||
560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581
		    (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.
 */

582
void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
583 584
{
	struct inet_sock *inet;
585
	const struct iphdr *iph = (const struct iphdr *)skb->data;
E
Eric Dumazet 已提交
586
	struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
587 588 589 590 591
	const int type = icmp_hdr(skb)->type;
	const int code = icmp_hdr(skb)->code;
	struct sock *sk;
	int harderr;
	int err;
592
	struct net *net = dev_net(skb->dev);
593

594
	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
595 596
			iph->saddr, uh->source, skb->dev->ifindex, udptable);
	if (sk == NULL) {
597
		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639
		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;
640
	} else
E
Eric Dumazet 已提交
641
		ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
642

643 644 645 646 647 648 649 650
	sk->sk_err = err;
	sk->sk_error_report(sk);
out:
	sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
651
	__udp4_lib_err(skb, info, &udp_table);
652 653 654 655 656
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
657
void udp_flush_pending_frames(struct sock *sk)
658 659 660 661 662 663 664 665 666
{
	struct udp_sock *up = udp_sk(sk);

	if (up->pending) {
		up->len = 0;
		up->pending = 0;
		ip_flush_pending_frames(sk);
	}
}
667
EXPORT_SYMBOL(udp_flush_pending_frames);
668 669

/**
H
Herbert Xu 已提交
670
 * 	udp4_hwcsum  -  handle outgoing HW checksumming
671 672
 * 	@skb: 	sk_buff containing the filled-in UDP header
 * 	        (checksum field must be zeroed out)
H
Herbert Xu 已提交
673 674
 *	@src:	source IP address
 *	@dst:	destination IP address
675
 */
H
Herbert Xu 已提交
676
static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
677 678
{
	struct udphdr *uh = udp_hdr(skb);
H
Herbert Xu 已提交
679 680 681 682
	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
	int hlen = len;
683 684
	__wsum csum = 0;

H
Herbert Xu 已提交
685
	if (!frags) {
686 687 688 689 690
		/*
		 * 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
691 692
		uh->check = ~csum_tcpudp_magic(src, dst, len,
					       IPPROTO_UDP, 0);
693 694 695 696 697 698
	} 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
699 700 701 702
		do {
			csum = csum_add(csum, frags->csum);
			hlen -= frags->len;
		} while ((frags = frags->next));
703

H
Herbert Xu 已提交
704
		csum = skb_checksum(skb, offset, hlen, csum);
705 706 707 708 709 710 711 712
		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;
	}
}

713
static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
714
{
H
Herbert Xu 已提交
715
	struct sock *sk = skb->sk;
716 717 718 719
	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
720 721
	int offset = skb_transport_offset(skb);
	int len = skb->len - offset;
722 723 724 725 726 727
	__wsum csum = 0;

	/*
	 * Create a UDP header
	 */
	uh = udp_hdr(skb);
H
Herbert Xu 已提交
728
	uh->source = inet->inet_sport;
729
	uh->dest = fl4->fl4_dport;
H
Herbert Xu 已提交
730
	uh->len = htons(len);
731 732 733
	uh->check = 0;

	if (is_udplite)  				 /*     UDP-Lite      */
H
Herbert Xu 已提交
734
		csum = udplite_csum(skb);
735 736 737 738 739 740 741 742

	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 */

743
		udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
744 745
		goto send;

H
Herbert Xu 已提交
746 747
	} else
		csum = udp_csum(skb);
748 749

	/* add protocol-dependent pseudo-header */
750
	uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
E
Eric Dumazet 已提交
751
				      sk->sk_protocol, csum);
752 753 754 755
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

send:
H
Herbert Xu 已提交
756
	err = ip_send_skb(skb);
E
Eric Dumazet 已提交
757 758 759 760 761 762 763 764 765
	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
766 767 768 769 770 771 772 773 774 775
	return err;
}

/*
 * 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);
D
David S. Miller 已提交
776
	struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
H
Herbert Xu 已提交
777 778 779
	struct sk_buff *skb;
	int err = 0;

780
	skb = ip_finish_skb(sk, fl4);
H
Herbert Xu 已提交
781 782 783
	if (!skb)
		goto out;

784
	err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
785

786 787 788 789 790 791 792 793 794 795 796
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);
797
	struct flowi4 fl4_stack;
D
David S. Miller 已提交
798
	struct flowi4 *fl4;
799 800 801 802 803 804 805 806 807 808 809
	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
810
	struct sk_buff *skb;
811
	struct ip_options_data opt_copy;
812 813 814 815 816 817 818 819

	if (len > 0xFFFF)
		return -EMSGSIZE;

	/*
	 *	Check the flags.
	 */

E
Eric Dumazet 已提交
820
	if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
821 822 823
		return -EOPNOTSUPP;

	ipc.opt = NULL;
824
	ipc.tx_flags = 0;
825

H
Herbert Xu 已提交
826 827
	getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;

828
	fl4 = &inet->cork.fl.u.ip4;
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849
	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
850
		struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
851 852 853 854 855 856 857 858 859 860 861 862 863 864
		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
865 866
		daddr = inet->inet_daddr;
		dport = inet->inet_dport;
867 868 869 870 871
		/* 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
872
	ipc.addr = inet->inet_saddr;
873 874

	ipc.oif = sk->sk_bound_dev_if;
875
	err = sock_tx_timestamp(sk, &ipc.tx_flags);
876 877
	if (err)
		return err;
878
	if (msg->msg_controllen) {
879
		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
880 881 882 883 884 885
		if (err)
			return err;
		if (ipc.opt)
			free = 1;
		connected = 0;
	}
886 887 888 889 890 891 892 893 894 895 896 897
	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();
	}
898 899 900 901

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

902
	if (ipc.opt && ipc.opt->opt.srr) {
903 904
		if (!daddr)
			return -EINVAL;
905
		faddr = ipc.opt->opt.faddr;
906 907 908 909 910
		connected = 0;
	}
	tos = RT_TOS(inet->tos);
	if (sock_flag(sk, SOCK_LOCALROUTE) ||
	    (msg->msg_flags & MSG_DONTROUTE) ||
911
	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
912 913 914 915 916 917 918 919 920 921
		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;
922 923
	} else if (!ipc.oif)
		ipc.oif = inet->uc_index;
924 925

	if (connected)
E
Eric Dumazet 已提交
926
		rt = (struct rtable *)sk_dst_check(sk, 0);
927 928

	if (rt == NULL) {
929 930
		struct net *net = sock_net(sk);

931 932
		fl4 = &fl4_stack;
		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
933 934 935 936
				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
				   inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
				   faddr, saddr, dport, inet->inet_sport);

937 938
		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
		rt = ip_route_output_flow(net, fl4, sk);
939 940
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
941
			rt = NULL;
942
			if (err == -ENETUNREACH)
943
				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
944 945 946 947 948 949 950 951
			goto out;
		}

		err = -EACCES;
		if ((rt->rt_flags & RTCF_BROADCAST) &&
		    !sock_flag(sk, SOCK_BROADCAST))
			goto out;
		if (connected)
952
			sk_dst_set(sk, dst_clone(&rt->dst));
953 954 955 956 957 958
	}

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

959
	saddr = fl4->saddr;
960
	if (!ipc.addr)
961
		daddr = ipc.addr = fl4->daddr;
962

H
Herbert Xu 已提交
963 964
	/* Lockless fast path for the non-corking case. */
	if (!corkreq) {
965
		skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
H
Herbert Xu 已提交
966 967 968 969
				  sizeof(struct udphdr), &ipc, &rt,
				  msg->msg_flags);
		err = PTR_ERR(skb);
		if (skb && !IS_ERR(skb))
970
			err = udp_send_skb(skb, fl4);
H
Herbert Xu 已提交
971 972 973
		goto out;
	}

974 975 976 977 978 979
	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);

980
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
981 982 983 984 985 986
		err = -EINVAL;
		goto out;
	}
	/*
	 *	Now cork the socket to pend data.
	 */
D
David S. Miller 已提交
987 988 989
	fl4 = &inet->cork.fl.u.ip4;
	fl4->daddr = daddr;
	fl4->saddr = saddr;
990 991
	fl4->fl4_dport = dport;
	fl4->fl4_sport = inet->inet_sport;
992 993 994 995
	up->pending = AF_INET;

do_append_data:
	up->len += ulen;
996 997 998
	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);
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
	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)) {
1021 1022
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_SNDBUFERRORS, is_udplite);
1023 1024 1025 1026
	}
	return err;

do_confirm:
1027
	dst_confirm(&rt->dst);
1028 1029 1030 1031 1032
	if (!(msg->msg_flags&MSG_PROBE) || len)
		goto back_from_confirm;
	err = 0;
	goto out;
}
E
Eric Dumazet 已提交
1033
EXPORT_SYMBOL(udp_sendmsg);
1034 1035 1036 1037

int udp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
1038
	struct inet_sock *inet = inet_sk(sk);
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
	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);

1059
		LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1060 1061 1062
		return -EINVAL;
	}

1063 1064
	ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
			     page, offset, size, flags);
1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
	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
1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105

/**
 *	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
1106
		atomic_inc(&sk->sk_drops);
E
Eric Dumazet 已提交
1107 1108 1109 1110 1111 1112 1113
		__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)) {
1114 1115
		bool slow = lock_sock_fast(sk);

E
Eric Dumazet 已提交
1116 1117
		__skb_queue_purge(&list_kill);
		sk_mem_reclaim_partial(sk);
1118
		unlock_sock_fast(sk, slow);
E
Eric Dumazet 已提交
1119 1120 1121 1122
	}
	return res;
}

L
Linus Torvalds 已提交
1123 1124 1125
/*
 *	IOCTL requests applicable to the UDP protocol
 */
1126

L
Linus Torvalds 已提交
1127 1128
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
1129 1130
	switch (cmd) {
	case SIOCOUTQ:
L
Linus Torvalds 已提交
1131
	{
1132 1133
		int amount = sk_wmem_alloc_get(sk);

1134 1135
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1136

1137 1138
	case SIOCINQ:
	{
E
Eric Dumazet 已提交
1139
		unsigned int amount = first_packet_length(sk);
1140

E
Eric Dumazet 已提交
1141
		if (amount)
1142 1143 1144 1145 1146
			/*
			 * We will only return the amount
			 * of this packet since that is all
			 * that will be read.
			 */
E
Eric Dumazet 已提交
1147 1148
			amount -= sizeof(struct udphdr);

1149 1150
		return put_user(amount, (int __user *)arg);
	}
L
Linus Torvalds 已提交
1151

1152 1153
	default:
		return -ENOIOCTLCMD;
L
Linus Torvalds 已提交
1154
	}
1155 1156

	return 0;
L
Linus Torvalds 已提交
1157
}
E
Eric Dumazet 已提交
1158
EXPORT_SYMBOL(udp_ioctl);
L
Linus Torvalds 已提交
1159

1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170
/*
 * 	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;
1171
	unsigned int ulen, copied;
1172
	int peeked, off = 0;
1173 1174
	int err;
	int is_udplite = IS_UDPLITE(sk);
1175
	bool slow;
1176 1177 1178 1179 1180

	/*
	 *	Check any passed addresses
	 */
	if (addr_len)
E
Eric Dumazet 已提交
1181
		*addr_len = sizeof(*sin);
1182 1183 1184 1185 1186 1187

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

try_again:
	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1188
				  &peeked, &off, &err);
1189 1190 1191 1192
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
1193 1194 1195 1196
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
1197 1198 1199 1200 1201 1202 1203 1204
		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.
	 */

1205
	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1206 1207 1208 1209 1210 1211
		if (udp_lib_checksum_complete(skb))
			goto csum_copy_err;
	}

	if (skb_csum_unnecessary(skb))
		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1212
					      msg->msg_iov, copied);
1213
	else {
E
Eric Dumazet 已提交
1214 1215 1216
		err = skb_copy_and_csum_datagram_iovec(skb,
						       sizeof(struct udphdr),
						       msg->msg_iov);
1217 1218 1219 1220 1221 1222 1223 1224 1225

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

	if (err)
		goto out_free;

	if (!peeked)
1226 1227
		UDP_INC_STATS_USER(sock_net(sk),
				UDP_MIB_INDATAGRAMS, is_udplite);
1228

1229
	sock_recv_ts_and_drops(msg, sk, skb);
1230 1231

	/* Copy the address. */
E
Eric Dumazet 已提交
1232
	if (sin) {
1233 1234 1235 1236 1237 1238 1239 1240
		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);

1241
	err = copied;
1242 1243 1244 1245
	if (flags & MSG_TRUNC)
		err = ulen;

out_free:
1246
	skb_free_datagram_locked(sk, skb);
1247 1248 1249 1250
out:
	return err;

csum_copy_err:
1251
	slow = lock_sock_fast(sk);
1252
	if (!skb_kill_datagram(sk, skb, flags))
1253
		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1254
	unlock_sock_fast(sk, slow);
1255 1256 1257

	if (noblock)
		return -EAGAIN;
1258 1259 1260

	/* starting over for a new packet */
	msg->msg_flags &= ~MSG_TRUNC;
1261 1262 1263 1264
	goto try_again;
}


L
Linus Torvalds 已提交
1265 1266 1267 1268 1269 1270
int udp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
	/*
	 *	1003.1g - break association.
	 */
1271

L
Linus Torvalds 已提交
1272
	sk->sk_state = TCP_CLOSE;
E
Eric Dumazet 已提交
1273 1274
	inet->inet_daddr = 0;
	inet->inet_dport = 0;
1275
	sock_rps_reset_rxhash(sk);
L
Linus Torvalds 已提交
1276 1277 1278 1279 1280 1281
	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
1282
		inet->inet_sport = 0;
L
Linus Torvalds 已提交
1283 1284 1285 1286
	}
	sk_dst_reset(sk);
	return 0;
}
E
Eric Dumazet 已提交
1287
EXPORT_SYMBOL(udp_disconnect);
L
Linus Torvalds 已提交
1288

1289 1290
void udp_lib_unhash(struct sock *sk)
{
1291 1292
	if (sk_hashed(sk)) {
		struct udp_table *udptable = sk->sk_prot->h.udp_table;
1293 1294 1295 1296 1297
		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);
1298

1299 1300
		spin_lock_bh(&hslot->lock);
		if (sk_nulls_del_node_init_rcu(sk)) {
E
Eric Dumazet 已提交
1301
			hslot->count--;
E
Eric Dumazet 已提交
1302
			inet_sk(sk)->inet_num = 0;
1303
			sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1304 1305 1306 1307 1308

			spin_lock(&hslot2->lock);
			hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
			hslot2->count--;
			spin_unlock(&hslot2->lock);
1309 1310
		}
		spin_unlock_bh(&hslot->lock);
1311 1312 1313 1314
	}
}
EXPORT_SYMBOL(udp_lib_unhash);

E
Eric Dumazet 已提交
1315 1316 1317 1318 1319 1320 1321 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
/*
 * 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
1358 1359
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
T
Tom Herbert 已提交
1360
	int rc;
E
Eric Dumazet 已提交
1361

T
Tom Herbert 已提交
1362
	if (inet_sk(sk)->inet_daddr)
1363
		sock_rps_save_rxhash(sk, skb);
T
Tom Herbert 已提交
1364

1365
	rc = sock_queue_rcv_skb(sk, skb);
E
Eric Dumazet 已提交
1366 1367
	if (rc < 0) {
		int is_udplite = IS_UDPLITE(sk);
H
Herbert Xu 已提交
1368 1369

		/* Note that an ENOMEM error is charged twice */
E
Eric Dumazet 已提交
1370
		if (rc == -ENOMEM)
H
Herbert Xu 已提交
1371 1372
			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
					 is_udplite);
E
Eric Dumazet 已提交
1373 1374
		UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
		kfree_skb(skb);
1375
		trace_udp_fail_queue_rcv_skb(rc, sk);
E
Eric Dumazet 已提交
1376
		return -1;
H
Herbert Xu 已提交
1377 1378 1379 1380 1381 1382
	}

	return 0;

}

1383 1384 1385 1386 1387 1388 1389 1390
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);

1391 1392 1393 1394 1395 1396 1397 1398
/* 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
1399
int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411
{
	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);

1412
	if (static_key_false(&udp_encap_needed) && up->encap_type) {
1413 1414
		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);

1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
		/*
		 * 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 */
1427 1428
		encap_rcv = ACCESS_ONCE(up->encap_rcv);
		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1429 1430
			int ret;

1431
			ret = encap_rcv(sk, skb);
1432
			if (ret <= 0) {
1433 1434
				UDP_INC_STATS_BH(sock_net(sk),
						 UDP_MIB_INDATAGRAMS,
1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
						 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  */
1460 1461
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
				       UDP_SKB_CB(skb)->cscov, skb->len);
1462 1463 1464 1465 1466 1467 1468 1469 1470
			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) {
1471 1472
			LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
1473 1474 1475 1476
			goto drop;
		}
	}

1477 1478 1479
	if (rcu_access_pointer(sk->sk_filter) &&
	    udp_lib_checksum_complete(skb))
		goto drop;
1480

1481 1482 1483 1484

	if (sk_rcvqueues_full(sk, skb))
		goto drop;

H
Herbert Xu 已提交
1485
	rc = 0;
1486

1487
	ipv4_pktinfo_prepare(skb);
H
Herbert Xu 已提交
1488 1489 1490
	bh_lock_sock(sk);
	if (!sock_owned_by_user(sk))
		rc = __udp_queue_rcv_skb(sk, skb);
Z
Zhu Yi 已提交
1491
	else if (sk_add_backlog(sk, skb)) {
Z
Zhu Yi 已提交
1492 1493 1494
		bh_unlock_sock(sk);
		goto drop;
	}
H
Herbert Xu 已提交
1495 1496 1497
	bh_unlock_sock(sk);

	return rc;
1498 1499

drop:
1500
	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
E
Eric Dumazet 已提交
1501
	atomic_inc(&sk->sk_drops);
1502 1503 1504 1505
	kfree_skb(skb);
	return -1;
}

1506 1507 1508 1509 1510 1511

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;
1512
	struct sock *sk;
1513 1514

	for (i = 0; i < count; i++) {
1515
		sk = stack[i];
1516 1517 1518
		if (likely(skb1 == NULL))
			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);

1519 1520 1521 1522 1523 1524 1525 1526 1527
		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)
1528 1529 1530 1531 1532 1533
			skb1 = NULL;
	}
	if (unlikely(skb1))
		kfree_skb(skb1);
}

1534 1535 1536
/*
 *	Multicasts and broadcasts go to each listener.
 *
1537
 *	Note: called only from the BH handler context.
1538
 */
1539
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1540 1541
				    struct udphdr  *uh,
				    __be32 saddr, __be32 daddr,
1542
				    struct udp_table *udptable)
1543
{
1544
	struct sock *sk, *stack[256 / sizeof(struct sock *)];
1545
	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1546
	int dif;
1547
	unsigned int i, count = 0;
1548

1549
	spin_lock(&hslot->lock);
1550
	sk = sk_nulls_head(&hslot->head);
1551
	dif = skb->dev->ifindex;
1552
	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569
	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]);

1570
	spin_unlock(&hslot->lock);
1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582

	/*
	 * 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);
	}
1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609
	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
1610
		if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627
				      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.
 */

1628
int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1629 1630 1631
		   int proto)
{
	struct sock *sk;
1632
	struct udphdr *uh;
1633
	unsigned short ulen;
E
Eric Dumazet 已提交
1634
	struct rtable *rt = skb_rtable(skb);
1635
	__be32 saddr, daddr;
1636
	struct net *net = dev_net(skb->dev);
1637 1638 1639 1640 1641 1642 1643

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

1644
	uh   = udp_hdr(skb);
1645
	ulen = ntohs(uh->len);
1646 1647 1648
	saddr = ip_hdr(skb)->saddr;
	daddr = ip_hdr(skb)->daddr;

1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662
	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))
1663 1664
		return __udp4_lib_mcast_deliver(net, skb, uh,
				saddr, daddr, udptable);
1665

1666
	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1667 1668

	if (sk != NULL) {
H
Herbert Xu 已提交
1669
		int ret = udp_queue_rcv_skb(sk, skb);
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
		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;

1688
	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1689 1690 1691 1692 1693 1694 1695 1696 1697 1698
	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:
1699
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1700 1701 1702 1703
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source),
		       ulen, skb->len,
		       &daddr, ntohs(uh->dest));
1704 1705 1706 1707 1708 1709 1710
	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).
	 */
1711
	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1712 1713
		       proto == IPPROTO_UDPLITE ? "Lite" : "",
		       &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1714 1715
		       ulen);
drop:
1716
	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1717 1718 1719 1720 1721 1722
	kfree_skb(skb);
	return 0;
}

int udp_rcv(struct sk_buff *skb)
{
1723
	return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1724 1725
}

1726
void udp_destroy_sock(struct sock *sk)
1727
{
1728
	bool slow = lock_sock_fast(sk);
1729
	udp_flush_pending_frames(sk);
1730
	unlock_sock_fast(sk, slow);
1731 1732
}

L
Linus Torvalds 已提交
1733 1734 1735
/*
 *	Socket option code for UDP
 */
1736
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1737
		       char __user *optval, unsigned int optlen,
1738
		       int (*push_pending_frames)(struct sock *))
L
Linus Torvalds 已提交
1739 1740 1741 1742
{
	struct udp_sock *up = udp_sk(sk);
	int val;
	int err = 0;
W
Wang Chen 已提交
1743
	int is_udplite = IS_UDPLITE(sk);
L
Linus Torvalds 已提交
1744

E
Eric Dumazet 已提交
1745
	if (optlen < sizeof(int))
L
Linus Torvalds 已提交
1746 1747 1748 1749 1750
		return -EINVAL;

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

1751
	switch (optname) {
L
Linus Torvalds 已提交
1752 1753 1754 1755 1756 1757
	case UDP_CORK:
		if (val != 0) {
			up->corkflag = 1;
		} else {
			up->corkflag = 0;
			lock_sock(sk);
1758
			(*push_pending_frames)(sk);
L
Linus Torvalds 已提交
1759 1760 1761
			release_sock(sk);
		}
		break;
1762

L
Linus Torvalds 已提交
1763 1764 1765 1766 1767
	case UDP_ENCAP:
		switch (val) {
		case 0:
		case UDP_ENCAP_ESPINUDP:
		case UDP_ENCAP_ESPINUDP_NON_IKE:
1768 1769
			up->encap_rcv = xfrm4_udp_encap_rcv;
			/* FALLTHROUGH */
1770
		case UDP_ENCAP_L2TPINUDP:
L
Linus Torvalds 已提交
1771
			up->encap_type = val;
1772
			udp_encap_enable();
L
Linus Torvalds 已提交
1773 1774 1775 1776 1777 1778 1779
			break;
		default:
			err = -ENOPROTOOPT;
			break;
		}
		break;

1780 1781 1782 1783 1784 1785
	/*
	 * 	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
1786
		if (!is_udplite)         /* Disable the option on UDP sockets */
1787 1788 1789
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
			val = 8;
1790 1791
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1792 1793 1794 1795
		up->pcslen = val;
		up->pcflag |= UDPLITE_SEND_CC;
		break;

1796 1797
	/* 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
1798 1799
	 * used, this again means full checksum coverage.                     */
	case UDPLITE_RECV_CSCOV:
W
Wang Chen 已提交
1800
		if (!is_udplite)         /* Disable the option on UDP sockets */
1801 1802 1803
			return -ENOPROTOOPT;
		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
			val = 8;
1804 1805
		else if (val > USHRT_MAX)
			val = USHRT_MAX;
1806 1807 1808 1809
		up->pcrlen = val;
		up->pcflag |= UDPLITE_RECV_CC;
		break;

L
Linus Torvalds 已提交
1810 1811 1812
	default:
		err = -ENOPROTOOPT;
		break;
1813
	}
L
Linus Torvalds 已提交
1814 1815 1816

	return err;
}
E
Eric Dumazet 已提交
1817
EXPORT_SYMBOL(udp_lib_setsockopt);
L
Linus Torvalds 已提交
1818

1819
int udp_setsockopt(struct sock *sk, int level, int optname,
1820
		   char __user *optval, unsigned int optlen)
1821 1822 1823 1824 1825 1826 1827 1828 1829
{
	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,
1830
			  char __user *optval, unsigned int optlen)
1831 1832 1833 1834 1835 1836 1837 1838
{
	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

1839 1840
int udp_lib_getsockopt(struct sock *sk, int level, int optname,
		       char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
1841 1842 1843 1844
{
	struct udp_sock *up = udp_sk(sk);
	int val, len;

E
Eric Dumazet 已提交
1845
	if (get_user(len, optlen))
L
Linus Torvalds 已提交
1846 1847 1848
		return -EFAULT;

	len = min_t(unsigned int, len, sizeof(int));
1849

1850
	if (len < 0)
L
Linus Torvalds 已提交
1851 1852
		return -EINVAL;

1853
	switch (optname) {
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859 1860 1861
	case UDP_CORK:
		val = up->corkflag;
		break;

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

1862 1863 1864 1865 1866 1867 1868 1869 1870 1871
	/* 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
1872 1873
	default:
		return -ENOPROTOOPT;
1874
	}
L
Linus Torvalds 已提交
1875

1876
	if (put_user(len, optlen))
1877
		return -EFAULT;
E
Eric Dumazet 已提交
1878
	if (copy_to_user(optval, &val, len))
L
Linus Torvalds 已提交
1879
		return -EFAULT;
1880
	return 0;
L
Linus Torvalds 已提交
1881
}
E
Eric Dumazet 已提交
1882
EXPORT_SYMBOL(udp_lib_getsockopt);
L
Linus Torvalds 已提交
1883

1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
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
1901 1902 1903 1904 1905 1906
/**
 * 	udp_poll - wait for a UDP event.
 *	@file - file struct
 *	@sock - socket
 *	@wait - poll table
 *
1907
 *	This is same as datagram poll, except for the special case of
L
Linus Torvalds 已提交
1908 1909 1910 1911 1912 1913 1914 1915 1916 1917
 *	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;
1918

L
Linus Torvalds 已提交
1919
	/* Check for false positives due to checksum errors */
E
Eric Dumazet 已提交
1920 1921 1922
	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
1923 1924

	return mask;
1925

L
Linus Torvalds 已提交
1926
}
E
Eric Dumazet 已提交
1927
EXPORT_SYMBOL(udp_poll);
L
Linus Torvalds 已提交
1928

1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941
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
1942
	.backlog_rcv	   = __udp_queue_rcv_skb,
1943 1944
	.hash		   = udp_lib_hash,
	.unhash		   = udp_lib_unhash,
E
Eric Dumazet 已提交
1945
	.rehash		   = udp_v4_rehash,
1946 1947 1948 1949 1950 1951
	.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),
1952
	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1953
	.h.udp_table	   = &udp_table,
1954 1955 1956 1957
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_udp_setsockopt,
	.compat_getsockopt = compat_udp_getsockopt,
#endif
1958
	.clear_sk	   = sk_prot_clear_portaddr_nulls,
1959
};
E
Eric Dumazet 已提交
1960
EXPORT_SYMBOL(udp_prot);
L
Linus Torvalds 已提交
1961 1962 1963 1964

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

1965
static struct sock *udp_get_first(struct seq_file *seq, int start)
L
Linus Torvalds 已提交
1966 1967 1968
{
	struct sock *sk;
	struct udp_iter_state *state = seq->private;
1969
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1970

1971 1972
	for (state->bucket = start; state->bucket <= state->udp_table->mask;
	     ++state->bucket) {
1973
		struct hlist_nulls_node *node;
1974
		struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1975 1976 1977 1978

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

1979
		spin_lock_bh(&hslot->lock);
1980
		sk_nulls_for_each(sk, node, &hslot->head) {
1981
			if (!net_eq(sock_net(sk), net))
1982
				continue;
L
Linus Torvalds 已提交
1983 1984 1985
			if (sk->sk_family == state->family)
				goto found;
		}
1986
		spin_unlock_bh(&hslot->lock);
L
Linus Torvalds 已提交
1987 1988 1989 1990 1991 1992 1993 1994 1995
	}
	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;
1996
	struct net *net = seq_file_net(seq);
L
Linus Torvalds 已提交
1997 1998

	do {
1999
		sk = sk_nulls_next(sk);
2000
	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
L
Linus Torvalds 已提交
2001

2002
	if (!sk) {
2003
		if (state->bucket <= state->udp_table->mask)
2004
			spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2005
		return udp_get_first(seq, state->bucket + 1);
L
Linus Torvalds 已提交
2006 2007 2008 2009 2010 2011
	}
	return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
2012
	struct sock *sk = udp_get_first(seq, 0);
L
Linus Torvalds 已提交
2013 2014

	if (sk)
2015
		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
L
Linus Torvalds 已提交
2016 2017 2018 2019 2020 2021
			--pos;
	return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
2022
	struct udp_iter_state *state = seq->private;
2023
	state->bucket = MAX_UDP_PORTS;
2024

2025
	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
L
Linus Torvalds 已提交
2026 2027 2028 2029 2030 2031
}

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

2032
	if (v == SEQ_START_TOKEN)
L
Linus Torvalds 已提交
2033 2034 2035 2036 2037 2038 2039 2040 2041 2042
		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)
{
2043 2044
	struct udp_iter_state *state = seq->private;

2045
	if (state->bucket <= state->udp_table->mask)
2046
		spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
L
Linus Torvalds 已提交
2047 2048
}

2049
int udp_seq_open(struct inode *inode, struct file *file)
L
Linus Torvalds 已提交
2050 2051
{
	struct udp_seq_afinfo *afinfo = PDE(inode)->data;
2052 2053
	struct udp_iter_state *s;
	int err;
2054

2055 2056 2057 2058
	err = seq_open_net(inode, file, &afinfo->seq_ops,
			   sizeof(struct udp_iter_state));
	if (err < 0)
		return err;
2059

2060
	s = ((struct seq_file *)file->private_data)->private;
L
Linus Torvalds 已提交
2061
	s->family		= afinfo->family;
2062
	s->udp_table		= afinfo->udp_table;
2063
	return err;
2064
}
2065
EXPORT_SYMBOL(udp_seq_open);
2066

L
Linus Torvalds 已提交
2067
/* ------------------------------------------------------------------------ */
2068
int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2069 2070 2071 2072
{
	struct proc_dir_entry *p;
	int rc = 0;

2073 2074 2075 2076
	afinfo->seq_ops.start		= udp_seq_start;
	afinfo->seq_ops.next		= udp_seq_next;
	afinfo->seq_ops.stop		= udp_seq_stop;

2077
	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2078
			     afinfo->seq_fops, afinfo);
2079
	if (!p)
L
Linus Torvalds 已提交
2080 2081 2082
		rc = -ENOMEM;
	return rc;
}
E
Eric Dumazet 已提交
2083
EXPORT_SYMBOL(udp_proc_register);
L
Linus Torvalds 已提交
2084

2085
void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
L
Linus Torvalds 已提交
2086
{
2087
	proc_net_remove(net, afinfo->name);
L
Linus Torvalds 已提交
2088
}
E
Eric Dumazet 已提交
2089
EXPORT_SYMBOL(udp_proc_unregister);
2090 2091

/* ------------------------------------------------------------------------ */
2092 2093
static void udp4_format_sock(struct sock *sp, struct seq_file *f,
		int bucket, int *len)
2094 2095
{
	struct inet_sock *inet = inet_sk(sp);
E
Eric Dumazet 已提交
2096 2097 2098 2099
	__be32 dest = inet->inet_daddr;
	__be32 src  = inet->inet_rcv_saddr;
	__u16 destp	  = ntohs(inet->inet_dport);
	__u16 srcp	  = ntohs(inet->inet_sport);
2100

2101
	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
D
Dan Rosenberg 已提交
2102
		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
2103
		bucket, src, srcp, dest, destp, sp->sk_state,
2104 2105
		sk_wmem_alloc_get(sp),
		sk_rmem_alloc_get(sp),
2106
		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
E
Eric Dumazet 已提交
2107 2108
		atomic_read(&sp->sk_refcnt), sp,
		atomic_read(&sp->sk_drops), len);
2109 2110 2111 2112 2113 2114 2115 2116
}

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
2117
			   "inode ref pointer drops");
2118 2119
	else {
		struct udp_iter_state *state = seq->private;
2120
		int len;
2121

2122
		udp4_format_sock(v, seq, state->bucket, &len);
E
Eric Dumazet 已提交
2123
		seq_printf(seq, "%*s\n", 127 - len, "");
2124 2125 2126 2127
	}
	return 0;
}

2128 2129 2130 2131 2132 2133 2134 2135
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
};

2136 2137 2138 2139
/* ------------------------------------------------------------------------ */
static struct udp_seq_afinfo udp4_seq_afinfo = {
	.name		= "udp",
	.family		= AF_INET,
2140
	.udp_table	= &udp_table,
2141
	.seq_fops	= &udp_afinfo_seq_fops,
2142 2143 2144
	.seq_ops	= {
		.show		= udp4_seq_show,
	},
2145 2146
};

2147
static int __net_init udp4_proc_init_net(struct net *net)
2148 2149 2150 2151
{
	return udp_proc_register(net, &udp4_seq_afinfo);
}

2152
static void __net_exit udp4_proc_exit_net(struct net *net)
2153 2154 2155 2156 2157 2158 2159 2160 2161
{
	udp_proc_unregister(net, &udp4_seq_afinfo);
}

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

2162 2163
int __init udp4_proc_init(void)
{
2164
	return register_pernet_subsys(&udp4_net_ops);
2165 2166 2167 2168
}

void udp4_proc_exit(void)
{
2169
	unregister_pernet_subsys(&udp4_net_ops);
2170
}
L
Linus Torvalds 已提交
2171 2172
#endif /* CONFIG_PROC_FS */

2173 2174
static __initdata unsigned long uhash_entries;
static int __init set_uhash_entries(char *str)
2175
{
2176 2177 2178 2179 2180 2181 2182 2183
	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);
2184

2185 2186 2187 2188 2189 2190
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,
2191
			2 * sizeof(struct udp_hslot),
2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202
			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 *
2203
				      2 * sizeof(struct udp_hslot), GFP_KERNEL);
2204 2205 2206 2207 2208
		if (!table->hash)
			panic(name);
		table->log = ilog2(UDP_HTABLE_SIZE_MIN);
		table->mask = UDP_HTABLE_SIZE_MIN - 1;
	}
2209
	table->hash2 = table->hash + (table->mask + 1);
2210
	for (i = 0; i <= table->mask; i++) {
2211
		INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
E
Eric Dumazet 已提交
2212
		table->hash[i].count = 0;
2213 2214
		spin_lock_init(&table->hash[i].lock);
	}
2215 2216 2217 2218 2219
	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);
	}
2220 2221
}

H
Hideo Aoki 已提交
2222 2223
void __init udp_init(void)
{
2224
	unsigned long limit;
H
Hideo Aoki 已提交
2225

2226
	udp_table_init(&udp_table, "UDP");
2227
	limit = nr_free_buffer_pages() / 8;
H
Hideo Aoki 已提交
2228 2229 2230 2231 2232 2233 2234 2235 2236
	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;
}

2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
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;
}

2256 2257
struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
	netdev_features_t features)
2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284
{
	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.
	 */
2285
	offset = skb_checksum_start_offset(skb);
E
Eric Dumazet 已提交
2286
	csum = skb_checksum(skb, offset, skb->len - offset, 0);
2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298
	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;
}