freebsd-dev/sys/netinet/ip_var.h
Julian Elischer f9e354df42 Support for IPFW based transparent forwarding.
Any packet that can be matched by a ipfw rule can be redirected
transparently to another port or machine. Redirection to another port
mostly makes sense with tcp, where a session can be set up
between a proxy and an unsuspecting client. Redirection to another machine
requires that the other machine also be expecting to receive the forwarded
packets, as their headers will not have been modified.

/sbin/ipfw must be recompiled!!!

Reviewed by:	Peter Wemm <peter@freebsd.org>
Submitted by: Chrisy Luke <chrisy@flix.net>
1998-07-06 03:20:19 +00:00

220 lines
8.2 KiB
C

/*
* Copyright (c) 1982, 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.
*
* @(#)ip_var.h 8.2 (Berkeley) 1/9/95
* $Id: ip_var.h,v 1.41 1998/06/08 09:47:42 bde Exp $
*/
#ifndef _NETINET_IP_VAR_H_
#define _NETINET_IP_VAR_H_
/*
* Overlay for ip header used by other protocols (tcp, udp).
*/
struct ipovly {
caddr_t ih_next, ih_prev; /* for protocol sequence q's */
u_char ih_x1; /* (unused) */
u_char ih_pr; /* protocol */
u_short ih_len; /* protocol length */
struct in_addr ih_src; /* source internet address */
struct in_addr ih_dst; /* destination internet address */
};
/*
* Ip reassembly queue structure. Each fragment
* being reassembled is attached to one of these structures.
* They are timed out after ipq_ttl drops to 0, and may also
* be reclaimed if memory becomes tight.
*/
struct ipq {
struct ipq *next,*prev; /* to other reass headers */
u_char ipq_ttl; /* time for reass q to live */
u_char ipq_p; /* protocol of this fragment */
u_short ipq_id; /* sequence id for reassembly */
struct ipasfrag *ipq_next,*ipq_prev;
/* to ip headers of fragments */
struct in_addr ipq_src,ipq_dst;
#ifdef IPDIVERT
u_short ipq_divert; /* divert protocol port */
u_short ipq_div_cookie; /* divert protocol cookie */
#endif
};
/*
* Ip header, when holding a fragment.
*
* Note: ipf_next must be at same offset as ipq_next above
*/
struct ipasfrag {
#if BYTE_ORDER == LITTLE_ENDIAN
u_int ip_hl:4,
ip_v:4;
#endif
#if BYTE_ORDER == BIG_ENDIAN
u_int ip_v:4,
ip_hl:4;
#endif
u_char ipf_mff; /* XXX overlays ip_tos: use low bit
* to avoid destroying tos;
* copied from (ip_off&IP_MF) */
u_short ip_len;
u_short ip_id;
u_short ip_off;
u_char ip_ttl;
u_char ip_p;
u_short ip_sum;
struct ipasfrag *ipf_next; /* next fragment */
struct ipasfrag *ipf_prev; /* previous fragment */
};
/*
* Structure stored in mbuf in inpcb.ip_options
* and passed to ip_output when ip options are in use.
* The actual length of the options (including ipopt_dst)
* is in m_len.
*/
#define MAX_IPOPTLEN 40
struct ipoption {
struct in_addr ipopt_dst; /* first-hop dst if source routed */
char ipopt_list[MAX_IPOPTLEN]; /* options proper */
};
/*
* Structure attached to inpcb.ip_moptions and
* passed to ip_output when IP multicast options are in use.
*/
struct ip_moptions {
struct ifnet *imo_multicast_ifp; /* ifp for outgoing multicasts */
u_char imo_multicast_ttl; /* TTL for outgoing multicasts */
u_char imo_multicast_loop; /* 1 => hear sends if a member */
u_short imo_num_memberships; /* no. memberships this socket */
struct in_multi *imo_membership[IP_MAX_MEMBERSHIPS];
u_long imo_multicast_vif; /* vif num outgoing multicasts */
};
struct ipstat {
u_long ips_total; /* total packets received */
u_long ips_badsum; /* checksum bad */
u_long ips_tooshort; /* packet too short */
u_long ips_toosmall; /* not enough data */
u_long ips_badhlen; /* ip header length < data size */
u_long ips_badlen; /* ip length < ip header length */
u_long ips_fragments; /* fragments received */
u_long ips_fragdropped; /* frags dropped (dups, out of space) */
u_long ips_fragtimeout; /* fragments timed out */
u_long ips_forward; /* packets forwarded */
u_long ips_fastforward; /* packets fast forwarded */
u_long ips_cantforward; /* packets rcvd for unreachable dest */
u_long ips_redirectsent; /* packets forwarded on same net */
u_long ips_noproto; /* unknown or unsupported protocol */
u_long ips_delivered; /* datagrams delivered to upper level*/
u_long ips_localout; /* total ip packets generated here */
u_long ips_odropped; /* lost packets due to nobufs, etc. */
u_long ips_reassembled; /* total packets reassembled ok */
u_long ips_fragmented; /* datagrams successfully fragmented */
u_long ips_ofragments; /* output fragments created */
u_long ips_cantfrag; /* don't fragment flag was set, etc. */
u_long ips_badoptions; /* error in option processing */
u_long ips_noroute; /* packets discarded due to no route */
u_long ips_badvers; /* ip version != 4 */
u_long ips_rawout; /* total raw ip packets generated */
u_long ips_toolong; /* ip length > max ip packet size */
u_long ips_notmember; /* multicasts for unregistered grps */
};
#ifdef KERNEL
/* flags passed to ip_output as last parameter */
#define IP_FORWARDING 0x1 /* most of ip header exists */
#define IP_RAWOUTPUT 0x2 /* raw ip header exists */
#define IP_ROUTETOIF SO_DONTROUTE /* bypass routing tables */
#define IP_ALLOWBROADCAST SO_BROADCAST /* can send broadcast packets */
struct inpcb;
struct route;
extern struct ipstat ipstat;
extern u_short ip_id; /* ip packet ctr, for ids */
extern int ip_defttl; /* default IP ttl */
extern int ipforwarding; /* ip forwarding */
extern u_char ip_protox[];
extern struct socket *ip_rsvpd; /* reservation protocol daemon */
extern struct socket *ip_mrouter; /* multicast routing daemon */
extern int (*legal_vif_num) __P((int));
extern u_long (*ip_mcast_src) __P((int));
extern int rsvp_on;
extern struct pr_usrreqs rip_usrreqs;
int ip_ctloutput __P((int, struct socket *, int, int, struct mbuf **,
struct proc *));
void ip_drain __P((void));
void ip_freemoptions __P((struct ip_moptions *));
void ip_init __P((void));
extern int (*ip_mforward) __P((struct ip *, struct ifnet *, struct mbuf *,
struct ip_moptions *));
int ip_output __P((struct mbuf *,
struct mbuf *, struct route *, int, struct ip_moptions *));
void ip_savecontrol __P((struct inpcb *, struct mbuf **, struct ip *,
struct mbuf *));
void ip_slowtimo __P((void));
struct mbuf *
ip_srcroute __P((void));
void ip_stripoptions __P((struct mbuf *, struct mbuf *));
int rip_ctloutput __P((int, struct socket *, int, int, struct mbuf **,
struct proc *p));
void rip_ctlinput __P((int, struct sockaddr *, void *));
void rip_init __P((void));
void rip_input __P((struct mbuf *, int));
int rip_output __P((struct mbuf *, struct socket *, u_long));
void ipip_input __P((struct mbuf *, int));
void rsvp_input __P((struct mbuf *, int));
int ip_rsvp_init __P((struct socket *));
int ip_rsvp_done __P((void));
int ip_rsvp_vif_init __P((struct socket *, struct mbuf *));
int ip_rsvp_vif_done __P((struct socket *, struct mbuf *));
void ip_rsvp_force_done __P((struct socket *));
#ifdef IPDIVERT
void div_init __P((void));
void div_input __P((struct mbuf *, int));
extern struct pr_usrreqs div_usrreqs;
extern u_short ip_divert_port;
extern u_short ip_divert_cookie;
#endif /* IPDIVERT */
struct sockaddr_in;
extern struct sockaddr_in *ip_fw_fwd_addr;
#endif /* KERNEL */
#endif /* _NETINET_IP_VAR_H_ */