xref: /freebsd-11-stable/sys/netinet/in.h

/*
 * 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 1.22 1996/10/22 22:25:54 sos 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
 */
#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_EGP		8		/* exterior gateway protocol */
#define	IPPROTO_PUP		12		/* pup */
#define	IPPROTO_UDP		17		/* user datagram protocol */
#define	IPPROTO_IDP		22		/* xns idp */
#define	IPPROTO_TP		29 		/* tp-4 w/ class negotiation */
#define IPPROTO_RSVP		46 		/* resource reservation */
#define	IPPROTO_EON		80		/* ISO cnlp */
#define	IPPROTO_ENCAP		98		/* encapsulation header */

#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.
 */

/*
 * 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	40000
#define	IPPORT_HILASTAUTO	44999

/*
 * 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_long 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)		(((long)(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)		(((long)(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)		(((long)(i) & 0xe0000000) == 0xc0000000)
#define	IN_CLASSC_NET		0xffffff00
#define	IN_CLASSC_NSHIFT	8
#define	IN_CLASSC_HOST		0x000000ff

#define	IN_CLASSD(i)		(((long)(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)	(((long)(i) & 0xf0000000) == 0xf0000000)
#define	IN_BADCLASS(i)		(((long)(i) & 0xf0000000) == 0xf0000000)

#define	INADDR_ANY		(u_long)0x00000000
#define	INADDR_BROADCAST	(u_long)0xffffffff	/* must be masked */
#ifndef KERNEL
#define	INADDR_NONE		0xffffffff		/* -1 return */
#endif

#define	INADDR_UNSPEC_GROUP	(u_long)0xe0000000	/* 224.0.0.0 */
#define	INADDR_ALLHOSTS_GROUP	(u_long)0xe0000001	/* 224.0.0.1 */
#define	INADDR_ALLRTRS_GROUP	(u_long)0xe0000002	/* 224.0.0.2 */
#define	INADDR_MAX_LOCAL_GROUP	(u_long)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_MAXID		12

#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 }, \
}


#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*, int, struct mbuf**));
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