savestr.c

网卡驱动相关实例 这是和网卡NT KMD驱动程序有关的一些资料和例子。主要是以下三方面内容: 3.1 article 一些有用的文档 3.2 Canberra 网络诊听工具Ethern

/*
 * Copyright (c) 1997
 *	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: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' 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.
 */

#ifndef lint
static const char rcsid[] =
    "@(#) $Header: savestr.c,v 1.2 97/05/09 14:52:31 leres Exp $ (LBL)";
#endif

#include <sys/types.h>

#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#include <stdio.h>

#include <stdlib.h>

#include "gnuc.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif

#define TCPDUMP_MAGIC 0xa1b2c3d4

/*
 * We use the "receiver-makes-right" approach to byte order,
 * because time is at a premium when we are writing the file.
 * In other words, the pcap_file_header and pcap_pkthdr,
 * records are written in host byte order.
 * Note that the packets are always written in network byte order.
 *
 * ntoh[ls] aren't sufficient because we might need to swap on a big-endian
 * machine (if the file was written in little-end order).
 */
#define	SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
#define	SWAPSHORT(y) \
	( (((y)&0xff)<<8) | ((u_short)((y)&0xff00)>>8) )

#define SFERR_TRUNC		1
#define SFERR_BADVERSION	2
#define SFERR_BADF		3
#define SFERR_EOF		4 /* not really an error, just a status */

/* A replacement for strdup() that cuts down on malloc() overhead */
char *
savestr(register const char *str)
{
	register u_int size;
	register char *p;
	static char *strptr = NULL;
	static u_int strsize = 0;

	size = strlen(str) + 1;
	if (size > strsize) {
		strsize = 1024;
		if (strsize < size)
			strsize = size;
		strptr = (char *)malloc(strsize);
		if (strptr == NULL) {
			fprintf(stderr, "savestr: malloc\n");
			exit(1);
		}
	}
	(void)strcpy(strptr, str);
	p = strptr;
	strptr += size;
	strsize -= size;
	return (p);
}