freebsd-skq/sys/netinet/in.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

450 lines
17 KiB
C

/*
* Copyright (c) 1982, 1986, 1990, 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.
*
* @(#)in.h 8.3 (Berkeley) 1/3/94
* $Id: in.h,v 1.35 1998/06/06 20:45:25 julian Exp $
*/
#ifndef _NETINET_IN_H_
#define _NETINET_IN_H_
/*
* Constants and structures defined by the internet system,
* Per RFC 790, September 1981, and numerous additions.
*/
/*
* Protocols (RFC 1700)
*/
#define IPPROTO_IP 0 /* dummy for IP */
#define IPPROTO_ICMP 1 /* control message protocol */
#define IPPROTO_IGMP 2 /* group mgmt protocol */
#define IPPROTO_GGP 3 /* gateway^2 (deprecated) */
#define IPPROTO_IPIP 4 /* IP encapsulation in IP */
#define IPPROTO_TCP 6 /* tcp */
#define IPPROTO_ST 7 /* Stream protocol II */
#define IPPROTO_EGP 8 /* exterior gateway protocol */
#define IPPROTO_PIGP 9 /* private interior gateway */
#define IPPROTO_RCCMON 10 /* BBN RCC Monitoring */
#define IPPROTO_NVPII 11 /* network voice protocol*/
#define IPPROTO_PUP 12 /* pup */
#define IPPROTO_ARGUS 13 /* Argus */
#define IPPROTO_EMCON 14 /* EMCON */
#define IPPROTO_XNET 15 /* Cross Net Debugger */
#define IPPROTO_CHAOS 16 /* Chaos*/
#define IPPROTO_UDP 17 /* user datagram protocol */
#define IPPROTO_MUX 18 /* Multiplexing */
#define IPPROTO_MEAS 19 /* DCN Measurement Subsystems */
#define IPPROTO_HMP 20 /* Host Monitoring */
#define IPPROTO_PRM 21 /* Packet Radio Measurement */
#define IPPROTO_IDP 22 /* xns idp */
#define IPPROTO_TRUNK1 23 /* Trunk-1 */
#define IPPROTO_TRUNK2 24 /* Trunk-2 */
#define IPPROTO_LEAF1 25 /* Leaf-1 */
#define IPPROTO_LEAF2 26 /* Leaf-2 */
#define IPPROTO_RDP 27 /* Reliable Data */
#define IPPROTO_IRTP 28 /* Reliable Transaction */
#define IPPROTO_TP 29 /* tp-4 w/ class negotiation */
#define IPPROTO_BLT 30 /* Bulk Data Transfer */
#define IPPROTO_NSP 31 /* Network Services */
#define IPPROTO_INP 32 /* Merit Internodal */
#define IPPROTO_SEP 33 /* Sequential Exchange */
#define IPPROTO_3PC 34 /* Third Party Connect */
#define IPPROTO_IDPR 35 /* InterDomain Policy Routing */
#define IPPROTO_XTP 36 /* XTP */
#define IPPROTO_DDP 37 /* Datagram Delivery */
#define IPPROTO_CMTP 38 /* Control Message Transport */
#define IPPROTO_TPXX 39 /* TP++ Transport */
#define IPPROTO_IL 40 /* IL transport protocol */
#define IPPROTO_SIP 41 /* Simple Internet Protocol */
#define IPPROTO_SDRP 42 /* Source Demand Routing */
#define IPPROTO_SIPSR 43 /* SIP Source Route */
#define IPPROTO_SIPFRAG 44 /* SIP Fragment */
#define IPPROTO_IDRP 45 /* InterDomain Routing*/
#define IPPROTO_RSVP 46 /* resource reservation */
#define IPPROTO_GRE 47 /* General Routing Encap. */
#define IPPROTO_MHRP 48 /* Mobile Host Routing */
#define IPPROTO_BHA 49 /* BHA */
#define IPPROTO_ESP 50 /* SIPP Encap Sec. Payload */
#define IPPROTO_AH 51 /* SIPP Auth Header */
#define IPPROTO_INLSP 52 /* Integ. Net Layer Security */
#define IPPROTO_SWIPE 53 /* IP with encryption */
#define IPPROTO_NHRP 54 /* Next Hop Resolution */
/* 55-60: Unassigned */
#define IPPROTO_AHIP 61 /* any host internal protocol */
#define IPPROTO_CFTP 62 /* CFTP */
#define IPPROTO_HELLO 63 /* "hello" routing protocol */
#define IPPROTO_SATEXPAK 64 /* SATNET/Backroom EXPAK */
#define IPPROTO_KRYPTOLAN 65 /* Kryptolan */
#define IPPROTO_RVD 66 /* Remote Virtual Disk */
#define IPPROTO_IPPC 67 /* Pluribus Packet Core */
#define IPPROTO_ADFS 68 /* Any distributed FS */
#define IPPROTO_SATMON 69 /* Satnet Monitoring */
#define IPPROTO_VISA 70 /* VISA Protocol */
#define IPPROTO_IPCV 71 /* Packet Core Utility */
#define IPPROTO_CPNX 72 /* Comp. Prot. Net. Executive */
#define IPPROTO_CPHB 73 /* Comp. Prot. HeartBeat */
#define IPPROTO_WSN 74 /* Wang Span Network */
#define IPPROTO_PVP 75 /* Packet Video Protocol */
#define IPPROTO_BRSATMON 76 /* BackRoom SATNET Monitoring */
#define IPPROTO_ND 77 /* Sun net disk proto (temp.) */
#define IPPROTO_WBMON 78 /* WIDEBAND Monitoring */
#define IPPROTO_WBEXPAK 79 /* WIDEBAND EXPAK */
#define IPPROTO_EON 80 /* ISO cnlp */
#define IPPROTO_VMTP 81 /* VMTP */
#define IPPROTO_SVMTP 82 /* Secure VMTP */
#define IPPROTO_VINES 83 /* Banyon VINES */
#define IPPROTO_TTP 84 /* TTP */
#define IPPROTO_IGP 85 /* NSFNET-IGP */
#define IPPROTO_DGP 86 /* dissimilar gateway prot. */
#define IPPROTO_TCF 87 /* TCF */
#define IPPROTO_IGRP 88 /* Cisco/GXS IGRP */
#define IPPROTO_OSPFIGP 89 /* OSPFIGP */
#define IPPROTO_SRPC 90 /* Strite RPC protocol */
#define IPPROTO_LARP 91 /* Locus Address Resoloution */
#define IPPROTO_MTP 92 /* Multicast Transport */
#define IPPROTO_AX25 93 /* AX.25 Frames */
#define IPPROTO_IPEIP 94 /* IP encapsulated in IP */
#define IPPROTO_MICP 95 /* Mobile Int.ing control */
#define IPPROTO_SCCSP 96 /* Semaphore Comm. security */
#define IPPROTO_ETHERIP 97 /* Ethernet IP encapsulation */
#define IPPROTO_ENCAP 98 /* encapsulation header */
#define IPPROTO_APES 99 /* any private encr. scheme */
#define IPPROTO_GMTP 100 /* GMTP*/
/* 101-254: Unassigned */
/* 255: Reserved */
/* BSD Private, local use, namespace incursion */
#define IPPROTO_DIVERT 254 /* divert pseudo-protocol */
#define IPPROTO_RAW 255 /* raw IP packet */
#define IPPROTO_MAX 256
/*
* Local port number conventions:
*
* When a user does a bind(2) or connect(2) with a port number of zero,
* a non-conflicting local port address is chosen.
* The default range is IPPORT_RESERVED through
* IPPORT_USERRESERVED, although that is settable by sysctl.
*
* A user may set the IPPROTO_IP option IP_PORTRANGE to change this
* default assignment range.
*
* The value IP_PORTRANGE_DEFAULT causes the default behavior.
*
* The value IP_PORTRANGE_HIGH changes the range of candidate port numbers
* into the "high" range. These are reserved for client outbound connections
* which do not want to be filtered by any firewalls.
*
* The value IP_PORTRANGE_LOW changes the range to the "low" are
* that is (by convention) restricted to privileged processes. This
* convention is based on "vouchsafe" principles only. It is only secure
* if you trust the remote host to restrict these ports.
*
* The default range of ports and the high range can be changed by
* sysctl(3). (net.inet.ip.port{hi,low}{first,last}_auto)
*
* Changing those values has bad security implications if you are
* using a a stateless firewall that is allowing packets outside of that
* range in order to allow transparent outgoing connections.
*
* Such a firewall configuration will generally depend on the use of these
* default values. If you change them, you may find your Security
* Administrator looking for you with a heavy object.
*
* For a slightly more orthodox text view on this:
*
* ftp://ftp.isi.edu/in-notes/iana/assignments/port-numbers
*
* port numbers are divided into three ranges:
*
* 0 - 1023 Well Known Ports
* 1024 - 49151 Registered Ports
* 49152 - 65535 Dynamic and/or Private Ports
*
*/
/*
* Ports < IPPORT_RESERVED are reserved for
* privileged processes (e.g. root). (IP_PORTRANGE_LOW)
* Ports > IPPORT_USERRESERVED are reserved
* for servers, not necessarily privileged. (IP_PORTRANGE_DEFAULT)
*/
#define IPPORT_RESERVED 1024
#define IPPORT_USERRESERVED 5000
/*
* Default local port range to use by setting IP_PORTRANGE_HIGH
*/
#define IPPORT_HIFIRSTAUTO 49152
#define IPPORT_HILASTAUTO 65535
/*
* Scanning for a free reserved port return a value below IPPORT_RESERVED,
* but higher than IPPORT_RESERVEDSTART. Traditionally the start value was
* 512, but that conflicts with some well-known-services that firewalls may
* have a fit if we use.
*/
#define IPPORT_RESERVEDSTART 600
/*
* Internet address (a structure for historical reasons)
*/
struct in_addr {
u_int32_t s_addr;
};
/*
* Definitions of bits in internet address integers.
* On subnets, the decomposition of addresses to host and net parts
* is done according to subnet mask, not the masks here.
*/
#define IN_CLASSA(i) (((u_int32_t)(i) & 0x80000000) == 0)
#define IN_CLASSA_NET 0xff000000
#define IN_CLASSA_NSHIFT 24
#define IN_CLASSA_HOST 0x00ffffff
#define IN_CLASSA_MAX 128
#define IN_CLASSB(i) (((u_int32_t)(i) & 0xc0000000) == 0x80000000)
#define IN_CLASSB_NET 0xffff0000
#define IN_CLASSB_NSHIFT 16
#define IN_CLASSB_HOST 0x0000ffff
#define IN_CLASSB_MAX 65536
#define IN_CLASSC(i) (((u_int32_t)(i) & 0xe0000000) == 0xc0000000)
#define IN_CLASSC_NET 0xffffff00
#define IN_CLASSC_NSHIFT 8
#define IN_CLASSC_HOST 0x000000ff
#define IN_CLASSD(i) (((u_int32_t)(i) & 0xf0000000) == 0xe0000000)
#define IN_CLASSD_NET 0xf0000000 /* These ones aren't really */
#define IN_CLASSD_NSHIFT 28 /* net and host fields, but */
#define IN_CLASSD_HOST 0x0fffffff /* routing needn't know. */
#define IN_MULTICAST(i) IN_CLASSD(i)
#define IN_EXPERIMENTAL(i) (((u_int32_t)(i) & 0xf0000000) == 0xf0000000)
#define IN_BADCLASS(i) (((u_int32_t)(i) & 0xf0000000) == 0xf0000000)
#define INADDR_ANY (u_int32_t)0x00000000
#define INADDR_LOOPBACK (u_int32_t)0x7f000001
#define INADDR_BROADCAST (u_int32_t)0xffffffff /* must be masked */
#ifndef KERNEL
#define INADDR_NONE 0xffffffff /* -1 return */
#endif
#define INADDR_UNSPEC_GROUP (u_int32_t)0xe0000000 /* 224.0.0.0 */
#define INADDR_ALLHOSTS_GROUP (u_int32_t)0xe0000001 /* 224.0.0.1 */
#define INADDR_ALLRTRS_GROUP (u_int32_t)0xe0000002 /* 224.0.0.2 */
#define INADDR_MAX_LOCAL_GROUP (u_int32_t)0xe00000ff /* 224.0.0.255 */
#define IN_LOOPBACKNET 127 /* official! */
/*
* Socket address, internet style.
*/
struct sockaddr_in {
u_char sin_len;
u_char sin_family;
u_short sin_port;
struct in_addr sin_addr;
char sin_zero[8];
};
/*
* Structure used to describe IP options.
* Used to store options internally, to pass them to a process,
* or to restore options retrieved earlier.
* The ip_dst is used for the first-hop gateway when using a source route
* (this gets put into the header proper).
*/
struct ip_opts {
struct in_addr ip_dst; /* first hop, 0 w/o src rt */
char ip_opts[40]; /* actually variable in size */
};
/*
* Options for use with [gs]etsockopt at the IP level.
* First word of comment is data type; bool is stored in int.
*/
#define IP_OPTIONS 1 /* buf/ip_opts; set/get IP options */
#define IP_HDRINCL 2 /* int; header is included with data */
#define IP_TOS 3 /* int; IP type of service and preced. */
#define IP_TTL 4 /* int; IP time to live */
#define IP_RECVOPTS 5 /* bool; receive all IP opts w/dgram */
#define IP_RECVRETOPTS 6 /* bool; receive IP opts for response */
#define IP_RECVDSTADDR 7 /* bool; receive IP dst addr w/dgram */
#define IP_RETOPTS 8 /* ip_opts; set/get IP options */
#define IP_MULTICAST_IF 9 /* u_char; set/get IP multicast i/f */
#define IP_MULTICAST_TTL 10 /* u_char; set/get IP multicast ttl */
#define IP_MULTICAST_LOOP 11 /* u_char; set/get IP multicast loopback */
#define IP_ADD_MEMBERSHIP 12 /* ip_mreq; add an IP group membership */
#define IP_DROP_MEMBERSHIP 13 /* ip_mreq; drop an IP group membership */
#define IP_MULTICAST_VIF 14 /* set/get IP mcast virt. iface */
#define IP_RSVP_ON 15 /* enable RSVP in kernel */
#define IP_RSVP_OFF 16 /* disable RSVP in kernel */
#define IP_RSVP_VIF_ON 17 /* set RSVP per-vif socket */
#define IP_RSVP_VIF_OFF 18 /* unset RSVP per-vif socket */
#define IP_PORTRANGE 19 /* int; range to choose for unspec port */
#define IP_RECVIF 20 /* bool; receive reception if w/dgram */
#define IP_FW_ADD 50 /* add a firewall rule to chain */
#define IP_FW_DEL 51 /* delete a firewall rule from chain */
#define IP_FW_FLUSH 52 /* flush firewall rule chain */
#define IP_FW_ZERO 53 /* clear single/all firewall counter(s) */
#define IP_FW_GET 54 /* get entire firewall rule chain */
#define IP_NAT 55 /* set/get NAT opts */
/*
* Defaults and limits for options
*/
#define IP_DEFAULT_MULTICAST_TTL 1 /* normally limit m'casts to 1 hop */
#define IP_DEFAULT_MULTICAST_LOOP 1 /* normally hear sends if a member */
#define IP_MAX_MEMBERSHIPS 20 /* per socket */
/*
* Argument structure for IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP.
*/
struct ip_mreq {
struct in_addr imr_multiaddr; /* IP multicast address of group */
struct in_addr imr_interface; /* local IP address of interface */
};
/*
* Argument for IP_PORTRANGE:
* - which range to search when port is unspecified at bind() or connect()
*/
#define IP_PORTRANGE_DEFAULT 0 /* default range */
#define IP_PORTRANGE_HIGH 1 /* "high" - request firewall bypass */
#define IP_PORTRANGE_LOW 2 /* "low" - vouchsafe security */
/*
* Definitions for inet sysctl operations.
*
* Third level is protocol number.
* Fourth level is desired variable within that protocol.
*/
#define IPPROTO_MAXID (IPPROTO_IDP + 1) /* don't list to IPPROTO_MAX */
#define CTL_IPPROTO_NAMES { \
{ "ip", CTLTYPE_NODE }, \
{ "icmp", CTLTYPE_NODE }, \
{ "igmp", CTLTYPE_NODE }, \
{ "ggp", CTLTYPE_NODE }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ "tcp", CTLTYPE_NODE }, \
{ 0, 0 }, \
{ "egp", CTLTYPE_NODE }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ "pup", CTLTYPE_NODE }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ "udp", CTLTYPE_NODE }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ 0, 0 }, \
{ "idp", CTLTYPE_NODE }, \
}
/*
* Names for IP sysctl objects
*/
#define IPCTL_FORWARDING 1 /* act as router */
#define IPCTL_SENDREDIRECTS 2 /* may send redirects when forwarding */
#define IPCTL_DEFTTL 3 /* default TTL */
#ifdef notyet
#define IPCTL_DEFMTU 4 /* default MTU */
#endif
#define IPCTL_RTEXPIRE 5 /* cloned route expiration time */
#define IPCTL_RTMINEXPIRE 6 /* min value for expiration time */
#define IPCTL_RTMAXCACHE 7 /* trigger level for dynamic expire */
#define IPCTL_SOURCEROUTE 8 /* may perform source routes */
#define IPCTL_DIRECTEDBROADCAST 9 /* may re-broadcast received packets */
#define IPCTL_INTRQMAXLEN 10 /* max length of netisr queue */
#define IPCTL_INTRQDROPS 11 /* number of netisr q drops */
#define IPCTL_STATS 12 /* ipstat structure */
#define IPCTL_ACCEPTSOURCEROUTE 13 /* may accept source routed packets */
#define IPCTL_FASTFORWARDING 14 /* use fast IP forwarding code */
#define IPCTL_MAXID 15
#define IPCTL_NAMES { \
{ 0, 0 }, \
{ "forwarding", CTLTYPE_INT }, \
{ "redirect", CTLTYPE_INT }, \
{ "ttl", CTLTYPE_INT }, \
{ "mtu", CTLTYPE_INT }, \
{ "rtexpire", CTLTYPE_INT }, \
{ "rtminexpire", CTLTYPE_INT }, \
{ "rtmaxcache", CTLTYPE_INT }, \
{ "sourceroute", CTLTYPE_INT }, \
{ "directed-broadcast", CTLTYPE_INT }, \
{ "intr-queue-maxlen", CTLTYPE_INT }, \
{ "intr-queue-drops", CTLTYPE_INT }, \
{ "stats", CTLTYPE_STRUCT }, \
{ "accept_sourceroute", CTLTYPE_INT }, \
{ "fastforwarding", CTLTYPE_INT }, \
}
#ifdef KERNEL
struct ifnet; struct mbuf; /* forward declarations for Standard C */
int in_broadcast __P((struct in_addr, struct ifnet *));
int in_canforward __P((struct in_addr));
int in_cksum __P((struct mbuf *, int));
int in_localaddr __P((struct in_addr));
char *inet_ntoa __P((struct in_addr)); /* in libkern */
/* Firewall hooks */
struct ip;
typedef int ip_fw_chk_t __P((struct ip**, int, struct ifnet*, u_int16_t*, struct mbuf**, struct sockaddr_in**));
typedef int ip_fw_ctl_t __P((int, struct mbuf**));
extern ip_fw_chk_t *ip_fw_chk_ptr;
extern ip_fw_ctl_t *ip_fw_ctl_ptr;
/* IP NAT hooks */
typedef int ip_nat_t __P((struct ip**, struct mbuf**, struct ifnet*, int));
typedef int ip_nat_ctl_t __P((int, struct mbuf**));
extern ip_nat_t *ip_nat_ptr;
extern ip_nat_ctl_t *ip_nat_ctl_ptr;
#define IP_NAT_IN 0x00000001
#define IP_NAT_OUT 0x00000002
#endif /* KERNEL */
#endif