in.h

著名操作系统Plan 9的第三版的部分核心源代码。现在很难找到了。Plan 9是bell实验室开发的Unix后继者。

#ifndef __netinet_in__
#define __netinet_in__

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Copyright (c) 1982, 1986, 1990 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution is only permitted until one year after the first shipment
 * of 4.4BSD by the Regents.  Otherwise, redistribution and use in source and
 * binary forms are permitted provided that: (1) source distributions retain
 * this entire copyright notice and comment, and (2) distributions including
 * binaries display the following acknowledgement:  This product includes
 * software developed by the University of California, Berkeley and its
 * contributors'' in the documentation or other materials provided with the
 * distribution and in all advertising materials mentioning features or use
 * of this software.  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 AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)in.h	7.10 (Berkeley) 6/28/90 plus MULTICAST 1.1
 */

/*
 * Constants and structures defined by the internet system,
 * Per RFC 790, September 1981.
 */

/*
 * Protocols
 */
#define	IPPROTO_IP		0		/* dummy for IP */
#define	IPPROTO_ICMP		1		/* control message protocol */
#define	IPPROTO_GGP		3		/* gateway^2 (deprecated) */
#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_EON		80		/* ISO cnlp */

#define	IPPROTO_RAW		255		/* raw IP packet */
#define	IPPROTO_MAX		256


/*
 * Local port number conventions:
 * Ports < IPPORT_RESERVED are reserved for
 * privileged processes (e.g. root).
 * Ports > IPPORT_USERRESERVED are reserved
 * for servers, not necessarily privileged.
 */
#define	IPPORT_RESERVED		1024
#define	IPPORT_USERRESERVED	5000

/*
 * Internet address (a structure for historical reasons)
 */
struct in_addr {
	unsigned 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_MULTICAST(i)		IN_CLASSD(i)

#define	IN_EXPERIMENTAL(i)	(((long)(i) & 0xe0000000) == 0xe0000000)
#define	IN_BADCLASS(i)		(((long)(i) & 0xf0000000) == 0xf0000000)

#define	INADDR_ANY		(unsigned long)0x00000000
#define	INADDR_BROADCAST	(unsigned long)0xffffffff	/* must be masked */

#define	IN_LOOPBACKNET		127			/* official! */

/*
 * Socket address, internet style.
 */
struct sockaddr_in {
	short	sin_family;
	unsigned 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 per-packet options */
#define	IP_HDRINCL	7	/* int; header is included with data (raw) */
#define	IP_TOS		8	/* int; IP type of service and precedence */
#define	IP_TTL		9	/* int; IP time to live */

extern unsigned long	ntohl(unsigned long x);
extern unsigned short	ntohs(unsigned short x);
extern unsigned long	htonl(unsigned long x);
extern unsigned short	htons(unsigned short x);
extern unsigned long	inet_addr(char*);
extern char*		inet_ntoa(struct in_addr);
extern unsigned long	nptohl(void*);

#ifdef __cplusplus
}
#endif

#endif /* __netinet_in__ */