alistair23-linux/include/net/route.h
Ilia Sotnikov cef2685e00 [IPV4]: Aggregate route entries with different TOS values
When we get an ICMP need-to-frag message, the original TOS value in the
ICMP payload cannot be used as a key to look up the routes to update.
This is because the TOS field may have been modified by routers on the
way.  Similarly, ip_rt_redirect should also ignore the TOS as the router
that gave us the message may have modified the TOS value.

The patch achieves this objective by aggregating entries with different
TOS values (but are otherwise identical) into the same bucket.  This
makes it easy to update them at the same time when an ICMP message is
received.

In future we should use a twin-hashing scheme where teh aggregation
occurs at the entry level.  That is, the TOS goes back into the hash
for normal lookups while ICMP lookups will end up with a node that
gives us a list that contains all other route entries that differ
only by TOS.

Signed-off-by: Ilia Sotnikov <hostcc@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-25 01:38:55 -08:00

205 lines
5.3 KiB
C

/*
* 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.
*
* Definitions for the IP router.
*
* Version: @(#)route.h 1.0.4 05/27/93
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Fixes:
* Alan Cox : Reformatted. Added ip_rt_local()
* Alan Cox : Support for TCP parameters.
* Alexey Kuznetsov: Major changes for new routing code.
* Mike McLagan : Routing by source
* Robert Olsson : Added rt_cache statistics
*
* 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.
*/
#ifndef _ROUTE_H
#define _ROUTE_H
#include <linux/config.h>
#include <net/dst.h>
#include <net/inetpeer.h>
#include <net/flow.h>
#include <linux/in_route.h>
#include <linux/rtnetlink.h>
#include <linux/route.h>
#include <linux/ip.h>
#include <linux/cache.h>
#ifndef __KERNEL__
#warning This file is not supposed to be used outside of kernel.
#endif
#define RTO_ONLINK 0x01
#define RTO_CONN 0
/* RTO_CONN is not used (being alias for 0), but preserved not to break
* some modules referring to it. */
#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
struct fib_nh;
struct inet_peer;
struct rtable
{
union
{
struct dst_entry dst;
struct rtable *rt_next;
} u;
struct in_device *idev;
unsigned rt_flags;
__u16 rt_type;
__u16 rt_multipath_alg;
__u32 rt_dst; /* Path destination */
__u32 rt_src; /* Path source */
int rt_iif;
/* Info on neighbour */
__u32 rt_gateway;
/* Cache lookup keys */
struct flowi fl;
/* Miscellaneous cached information */
__u32 rt_spec_dst; /* RFC1122 specific destination */
struct inet_peer *peer; /* long-living peer info */
};
struct ip_rt_acct
{
__u32 o_bytes;
__u32 o_packets;
__u32 i_bytes;
__u32 i_packets;
};
struct rt_cache_stat
{
unsigned int in_hit;
unsigned int in_slow_tot;
unsigned int in_slow_mc;
unsigned int in_no_route;
unsigned int in_brd;
unsigned int in_martian_dst;
unsigned int in_martian_src;
unsigned int out_hit;
unsigned int out_slow_tot;
unsigned int out_slow_mc;
unsigned int gc_total;
unsigned int gc_ignored;
unsigned int gc_goal_miss;
unsigned int gc_dst_overflow;
unsigned int in_hlist_search;
unsigned int out_hlist_search;
};
extern struct ip_rt_acct *ip_rt_acct;
struct in_device;
extern int ip_rt_init(void);
extern void ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
u32 src, struct net_device *dev);
extern void ip_rt_advice(struct rtable **rp, int advice);
extern void rt_cache_flush(int how);
extern int __ip_route_output_key(struct rtable **, const struct flowi *flp);
extern int ip_route_output_key(struct rtable **, struct flowi *flp);
extern int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
extern int ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
extern unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
extern void ip_rt_send_redirect(struct sk_buff *skb);
extern unsigned inet_addr_type(u32 addr);
extern void ip_rt_multicast_event(struct in_device *);
extern int ip_rt_ioctl(unsigned int cmd, void __user *arg);
extern void ip_rt_get_source(u8 *src, struct rtable *rt);
extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb);
struct in_ifaddr;
extern void fib_add_ifaddr(struct in_ifaddr *);
static inline void ip_rt_put(struct rtable * rt)
{
if (rt)
dst_release(&rt->u.dst);
}
#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
extern __u8 ip_tos2prio[16];
static inline char rt_tos2priority(u8 tos)
{
return ip_tos2prio[IPTOS_TOS(tos)>>1];
}
static inline int ip_route_connect(struct rtable **rp, u32 dst,
u32 src, u32 tos, int oif, u8 protocol,
u16 sport, u16 dport, struct sock *sk)
{
struct flowi fl = { .oif = oif,
.nl_u = { .ip4_u = { .daddr = dst,
.saddr = src,
.tos = tos } },
.proto = protocol,
.uli_u = { .ports =
{ .sport = sport,
.dport = dport } } };
int err;
if (!dst || !src) {
err = __ip_route_output_key(rp, &fl);
if (err)
return err;
fl.fl4_dst = (*rp)->rt_dst;
fl.fl4_src = (*rp)->rt_src;
ip_rt_put(*rp);
*rp = NULL;
}
return ip_route_output_flow(rp, &fl, sk, 0);
}
static inline int ip_route_newports(struct rtable **rp, u8 protocol,
u16 sport, u16 dport, struct sock *sk)
{
if (sport != (*rp)->fl.fl_ip_sport ||
dport != (*rp)->fl.fl_ip_dport) {
struct flowi fl;
memcpy(&fl, &(*rp)->fl, sizeof(fl));
fl.fl_ip_sport = sport;
fl.fl_ip_dport = dport;
fl.proto = protocol;
ip_rt_put(*rp);
*rp = NULL;
return ip_route_output_flow(rp, &fl, sk, 0);
}
return 0;
}
extern void rt_bind_peer(struct rtable *rt, int create);
static inline struct inet_peer *rt_get_peer(struct rtable *rt)
{
if (rt->peer)
return rt->peer;
rt_bind_peer(rt, 0);
return rt->peer;
}
extern ctl_table ipv4_route_table[];
#endif /* _ROUTE_H */