freebsd-src/sys/net/route.h
Jayanth Vijayaraghavan e7f3269307 When a connection is being dropped due to a listen queue overflow,
delete the cloned route that is associated with the connection.
This does not exhaust the routing table memory when the system
is under a SYN flood attack. The route entry is not deleted if there
is any prior information cached in it.

Reviewed by: Peter Wemm,asmodai
2000-07-21 23:26:37 +00:00

297 lines
11 KiB
C

/*
* Copyright (c) 1980, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)route.h 8.3 (Berkeley) 4/19/94
* $FreeBSD$
*/
#ifndef _NET_ROUTE_H_
#define _NET_ROUTE_H_
/*
* Kernel resident routing tables.
*
* The routing tables are initialized when interface addresses
* are set by making entries for all directly connected interfaces.
*/
/*
* A route consists of a destination address and a reference
* to a routing entry. These are often held by protocols
* in their control blocks, e.g. inpcb.
*/
struct route {
struct rtentry *ro_rt;
struct sockaddr ro_dst;
};
/*
* These numbers are used by reliable protocols for determining
* retransmission behavior and are included in the routing structure.
*/
struct rt_metrics {
u_long rmx_locks; /* Kernel must leave these values alone */
u_long rmx_mtu; /* MTU for this path */
u_long rmx_hopcount; /* max hops expected */
u_long rmx_expire; /* lifetime for route, e.g. redirect */
u_long rmx_recvpipe; /* inbound delay-bandwidth product */
u_long rmx_sendpipe; /* outbound delay-bandwidth product */
u_long rmx_ssthresh; /* outbound gateway buffer limit */
u_long rmx_rtt; /* estimated round trip time */
u_long rmx_rttvar; /* estimated rtt variance */
u_long rmx_pksent; /* packets sent using this route */
u_long rmx_filler[4]; /* will be used for T/TCP later */
};
/*
* rmx_rtt and rmx_rttvar are stored as microseconds;
* RTTTOPRHZ(rtt) converts to a value suitable for use
* by a protocol slowtimo counter.
*/
#define RTM_RTTUNIT 1000000 /* units for rtt, rttvar, as units per sec */
#define RTTTOPRHZ(r) ((r) / (RTM_RTTUNIT / PR_SLOWHZ))
/*
* XXX kernel function pointer `rt_output' is visible to applications.
*/
struct mbuf;
/*
* We distinguish between routes to hosts and routes to networks,
* preferring the former if available. For each route we infer
* the interface to use from the gateway address supplied when
* the route was entered. Routes that forward packets through
* gateways are marked so that the output routines know to address the
* gateway rather than the ultimate destination.
*/
#ifndef RNF_NORMAL
#include <net/radix.h>
#endif
struct rtentry {
struct radix_node rt_nodes[2]; /* tree glue, and other values */
#define rt_key(r) ((struct sockaddr *)((r)->rt_nodes->rn_key))
#define rt_mask(r) ((struct sockaddr *)((r)->rt_nodes->rn_mask))
struct sockaddr *rt_gateway; /* value */
long rt_refcnt; /* # held references */
u_long rt_flags; /* up/down?, host/net */
struct ifnet *rt_ifp; /* the answer: interface to use */
struct ifaddr *rt_ifa; /* the answer: interface to use */
struct sockaddr *rt_genmask; /* for generation of cloned routes */
caddr_t rt_llinfo; /* pointer to link level info cache */
struct rt_metrics rt_rmx; /* metrics used by rx'ing protocols */
struct rtentry *rt_gwroute; /* implied entry for gatewayed routes */
int (*rt_output) __P((struct ifnet *, struct mbuf *,
struct sockaddr *, struct rtentry *));
/* output routine for this (rt,if) */
struct rtentry *rt_parent; /* cloning parent of this route */
void *rt_filler2; /* more filler */
};
/*
* Following structure necessary for 4.3 compatibility;
* We should eventually move it to a compat file.
*/
struct ortentry {
u_long rt_hash; /* to speed lookups */
struct sockaddr rt_dst; /* key */
struct sockaddr rt_gateway; /* value */
short rt_flags; /* up/down?, host/net */
short rt_refcnt; /* # held references */
u_long rt_use; /* raw # packets forwarded */
struct ifnet *rt_ifp; /* the answer: interface to use */
};
#define rt_use rt_rmx.rmx_pksent
#define RTF_UP 0x1 /* route usable */
#define RTF_GATEWAY 0x2 /* destination is a gateway */
#define RTF_HOST 0x4 /* host entry (net otherwise) */
#define RTF_REJECT 0x8 /* host or net unreachable */
#define RTF_DYNAMIC 0x10 /* created dynamically (by redirect) */
#define RTF_MODIFIED 0x20 /* modified dynamically (by redirect) */
#define RTF_DONE 0x40 /* message confirmed */
#define RTF_DELCLONE 0x80 /* delete cloned route */
#define RTF_CLONING 0x100 /* generate new routes on use */
#define RTF_XRESOLVE 0x200 /* external daemon resolves name */
#define RTF_LLINFO 0x400 /* generated by link layer (e.g. ARP) */
#define RTF_STATIC 0x800 /* manually added */
#define RTF_BLACKHOLE 0x1000 /* just discard pkts (during updates) */
#define RTF_PROTO2 0x4000 /* protocol specific routing flag */
#define RTF_PROTO1 0x8000 /* protocol specific routing flag */
#define RTF_PRCLONING 0x10000 /* protocol requires cloning */
#define RTF_WASCLONED 0x20000 /* route generated through cloning */
#define RTF_PROTO3 0x40000 /* protocol specific routing flag */
/* 0x80000 unused */
#define RTF_PINNED 0x100000 /* future use */
#define RTF_LOCAL 0x200000 /* route represents a local address */
#define RTF_BROADCAST 0x400000 /* route represents a bcast address */
#define RTF_MULTICAST 0x800000 /* route represents a mcast address */
/* 0x1000000 and up unassigned */
/*
* Routing statistics.
*/
struct rtstat {
short rts_badredirect; /* bogus redirect calls */
short rts_dynamic; /* routes created by redirects */
short rts_newgateway; /* routes modified by redirects */
short rts_unreach; /* lookups which failed */
short rts_wildcard; /* lookups satisfied by a wildcard */
};
/*
* Structures for routing messages.
*/
struct rt_msghdr {
u_short rtm_msglen; /* to skip over non-understood messages */
u_char rtm_version; /* future binary compatibility */
u_char rtm_type; /* message type */
u_short rtm_index; /* index for associated ifp */
int rtm_flags; /* flags, incl. kern & message, e.g. DONE */
int rtm_addrs; /* bitmask identifying sockaddrs in msg */
pid_t rtm_pid; /* identify sender */
int rtm_seq; /* for sender to identify action */
int rtm_errno; /* why failed */
int rtm_use; /* from rtentry */
u_long rtm_inits; /* which metrics we are initializing */
struct rt_metrics rtm_rmx; /* metrics themselves */
};
#define RTM_VERSION 5 /* Up the ante and ignore older versions */
/*
* Message types.
*/
#define RTM_ADD 0x1 /* Add Route */
#define RTM_DELETE 0x2 /* Delete Route */
#define RTM_CHANGE 0x3 /* Change Metrics or flags */
#define RTM_GET 0x4 /* Report Metrics */
#define RTM_LOSING 0x5 /* Kernel Suspects Partitioning */
#define RTM_REDIRECT 0x6 /* Told to use different route */
#define RTM_MISS 0x7 /* Lookup failed on this address */
#define RTM_LOCK 0x8 /* fix specified metrics */
#define RTM_OLDADD 0x9 /* caused by SIOCADDRT */
#define RTM_OLDDEL 0xa /* caused by SIOCDELRT */
#define RTM_RESOLVE 0xb /* req to resolve dst to LL addr */
#define RTM_NEWADDR 0xc /* address being added to iface */
#define RTM_DELADDR 0xd /* address being removed from iface */
#define RTM_IFINFO 0xe /* iface going up/down etc. */
#define RTM_NEWMADDR 0xf /* mcast group membership being added to if */
#define RTM_DELMADDR 0x10 /* mcast group membership being deleted */
/*
* Bitmask values for rtm_inits and rmx_locks.
*/
#define RTV_MTU 0x1 /* init or lock _mtu */
#define RTV_HOPCOUNT 0x2 /* init or lock _hopcount */
#define RTV_EXPIRE 0x4 /* init or lock _expire */
#define RTV_RPIPE 0x8 /* init or lock _recvpipe */
#define RTV_SPIPE 0x10 /* init or lock _sendpipe */
#define RTV_SSTHRESH 0x20 /* init or lock _ssthresh */
#define RTV_RTT 0x40 /* init or lock _rtt */
#define RTV_RTTVAR 0x80 /* init or lock _rttvar */
/*
* Bitmask values for rtm_addrs.
*/
#define RTA_DST 0x1 /* destination sockaddr present */
#define RTA_GATEWAY 0x2 /* gateway sockaddr present */
#define RTA_NETMASK 0x4 /* netmask sockaddr present */
#define RTA_GENMASK 0x8 /* cloning mask sockaddr present */
#define RTA_IFP 0x10 /* interface name sockaddr present */
#define RTA_IFA 0x20 /* interface addr sockaddr present */
#define RTA_AUTHOR 0x40 /* sockaddr for author of redirect */
#define RTA_BRD 0x80 /* for NEWADDR, broadcast or p-p dest addr */
/*
* Index offsets for sockaddr array for alternate internal encoding.
*/
#define RTAX_DST 0 /* destination sockaddr present */
#define RTAX_GATEWAY 1 /* gateway sockaddr present */
#define RTAX_NETMASK 2 /* netmask sockaddr present */
#define RTAX_GENMASK 3 /* cloning mask sockaddr present */
#define RTAX_IFP 4 /* interface name sockaddr present */
#define RTAX_IFA 5 /* interface addr sockaddr present */
#define RTAX_AUTHOR 6 /* sockaddr for author of redirect */
#define RTAX_BRD 7 /* for NEWADDR, broadcast or p-p dest addr */
#define RTAX_MAX 8 /* size of array to allocate */
struct rt_addrinfo {
int rti_addrs;
struct sockaddr *rti_info[RTAX_MAX];
};
struct route_cb {
int ip_count;
int ip6_count;
int ipx_count;
int ns_count;
int any_count;
};
#ifdef _KERNEL
#define RTFREE(rt) \
do { \
if ((rt)->rt_refcnt <= 1) \
rtfree(rt); \
else \
(rt)->rt_refcnt--; \
} while (0)
extern struct route_cb route_cb;
extern struct radix_node_head *rt_tables[AF_MAX+1];
struct ifmultiaddr;
struct proc;
void route_init __P((void));
void rt_ifmsg __P((struct ifnet *));
void rt_missmsg __P((int, struct rt_addrinfo *, int, int));
void rt_newaddrmsg __P((int, struct ifaddr *, int, struct rtentry *));
void rt_newmaddrmsg __P((int, struct ifmultiaddr *));
int rt_setgate __P((struct rtentry *,
struct sockaddr *, struct sockaddr *));
void rtalloc __P((struct route *));
void rtalloc_ign __P((struct route *, u_long));
struct rtentry *
rtalloc1 __P((struct sockaddr *, int, u_long));
void rtfree __P((struct rtentry *));
int rtinit __P((struct ifaddr *, int, int));
int rtioctl __P((int, caddr_t, struct proc *));
void rtredirect __P((struct sockaddr *, struct sockaddr *,
struct sockaddr *, int, struct sockaddr *, struct rtentry **));
int rtrequest __P((int, struct sockaddr *,
struct sockaddr *, struct sockaddr *, int, struct rtentry **));
#endif
#endif