as_http.h

实现了在arp欺骗环境下

#ifndef __AS_HTTP_H__
#define __AS_HTTP_H__

#define XLS		0x01
#define DOC		0x02
#define PPT		0x03
#define PDF		0x04
#define EXE		0x05
#define ZIP		0x06
#define RAR		0x07
#define RM		0x08
#define SWF		0x09
#define TXT		0x0a
#define AVI		0x0b
#define BMP		0x0c
#define JPG		0x0d

//////////////////////////////////////////////////////////////////////////
//过滤http报文头部，获得Content-Length
//////////////////////////////////////////////////////////////////////////
int DecodeHTTP(const u_char *datatcp, u_int lentcp, ULONG &clen, int &postion)
{
	if(lentcp <= 0) {
		return 0;
	}

	if(memcmp(datatcp, "HTTP", 4) != 0) return 0;
	if(memcmp(datatcp+9, "200", 3) != 0) return 0;

	char *str = new char[lentcp+1];
	memcpy(str, datatcp, lentcp);
	str[lentcp] = '\0';

	char *pdest;
	char seps[5] = {0x0d, 0x0a, 0x0d, 0x0a};
	char *seps1 = "Content-Length";

	pdest = strstr(str, seps1 );
	if( pdest == NULL ) return 0;
	else {
		clen = atol(pdest+16);
	}

	pdest = strstr(str, seps );
	if( pdest == NULL ) return 0;
	else {
		postion = (int)(pdest - str + 1) + 3;
	}

	delete []str;
	return 1;
}
//////////////////////////////////////////////////////////////////////////
//	根据GET报文的URL字段判断要下载的文件类型
int get_ftype(const u_char *datatcp, u_int lentcp)
{
	if(lentcp <= 0) {
		return 0;
	}

	char seps1[3] = {0x0d, 0x0a};
	char seps2[2] = {0x20};
	char *token = NULL;

	char *str = new char[lentcp+1];
	memcpy(str, datatcp, lentcp);
	str[lentcp] = '\0';

	token = strtok( str, seps1);

	token = strtok( str, seps2);
	
	if(token != NULL) {
		token = strtok( NULL, seps2);
		int len = strlen(token)-4;
		if (memcmp(token+len, ".exe", 4) == 0) {
			return EXE;
		}
		if (memcmp(token+len, ".doc", 4) == 0) {
			return DOC;
		}
		if (memcmp(token+len, ".xls", 4) == 0) {
			return XLS;
		}
		if (memcmp(token+len, ".pdf", 4) == 0) {
			return PDF;
		}
		if (memcmp(token+len, ".rar", 4) == 0) {
			return RAR;
		}
		if (memcmp(token+len, ".zip", 4) == 0) {
			return ZIP;
		}
	}
	delete []str;
	return 0;
}

#endif