/*
* ip_vs_xmit.c: various packet transmitters for IPVS
*
* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
* Julian Anastasov <ja@ssi.bg>
*
* 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.
*
* Changes:
*
* Description of forwarding methods:
* - all transmitters are called from LOCAL_IN (remote clients) and
* LOCAL_OUT (local clients) but for ICMP can be called from FORWARD
* - not all connections have destination server, for example,
* connections in backup server when fwmark is used
* - bypass connections use daddr from packet
* LOCAL_OUT rules:
* - skb->dev is NULL, skb->protocol is not set (both are set in POST_ROUTING)
* - skb->pkt_type is not set yet
* - the only place where we can see skb->sk != NULL
*/
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/tcp.h> /* for tcphdr */
#include <net/ip.h>
#include <net/tcp.h> /* for csum_tcpudp_magic */
#include <net/udp.h>
#include <net/icmp.h> /* for icmp_send */
#include <net/route.h> /* for ip_route_output */
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <linux/icmpv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <net/ip_vs.h>
enum {
IP_VS_RT_MODE_LOCAL = 1, /* Allow local dest */
IP_VS_RT_MODE_NON_LOCAL = 2, /* Allow non-local dest */
IP_VS_RT_MODE_RDR = 4, /* Allow redirect from remote daddr to
* local
*/
IP_VS_RT_MODE_CONNECT = 8, /* Always bind route to saddr */
IP_VS_RT_MODE_KNOWN_NH = 16,/* Route via remote addr */
};
/*
* Destination cache to speed up outgoing route lookup
*/
static inline void
__ip_vs_dst_set(struct ip_vs_dest *dest, u32 rtos, struct dst_entry *dst,
u32 dst_cookie)
{
struct dst_entry *old_dst;
old_dst = dest->dst_cache;
dest->dst_cache = dst;
dest->dst_rtos