pjs/webtools/web-sniffer/dns.c

162 строки
3.2 KiB
C

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is SniffURI.
*
* The Initial Developer of the Original Code is
* Erik van der Poel <erik@vanderpoel.org>.
* Portions created by the Initial Developer are Copyright (C) 1998-2005
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* ***** END LICENSE BLOCK ***** */
#include "all.h"
#define server (unsigned char *) "host.domain.com"
#define QR 0 /* query */
#define OPCODE 0 /* standard query */
#define AA 0 /* authoritative answer */
#define TC 0 /* truncation */
#define RD 1 /* recursion desired */
#define RA 0 /* recursion available */
#define Z 0 /* reserved */
#define RCODE 0 /* response code */
static unsigned short ID = 0xbeef;
static unsigned char *
putDomainName(unsigned char *p, char *name)
{
char *begin;
char *q;
q = name;
while (*q)
{
begin = q;
while (*q && (*q != '.'))
{
q++;
}
if (q - begin > 0)
{
*p++ = q - begin;
q = begin;
while (*q && (*q != '.'))
{
*p++ = *q++;
}
if (*q == '.')
{
q++;
}
}
}
*p++ = 0;
return p;
}
int
main(int argc, char *argv[])
{
unsigned char buf[1024];
int bytesTransferred;
int c;
int fd;
int i;
int len;
unsigned char *p;
if (!netInit())
{
return 1;
}
if (!threadInit())
{
return 1;
}
fd = netConnect(NULL, server, 53);
if (fd < 0)
{
fprintf(stderr, "netConnect failed\n");
return 1;
}
p = buf + 2;
p[0] = (ID >> 8);
p[1] = (ID & 0xff);
p[2] = (QR | OPCODE | AA | TC | RD);
p[3] = (RA | Z | RCODE);
p[4] = 0; /* QDCOUNT */
p[5] = 1; /* QDCOUNT */
p[6] = 0; /* ANCOUNT */
p[7] = 0; /* ANCOUNT */
p[8] = 0; /* NSCOUNT */
p[9] = 0; /* NSCOUNT */
p[10] = 0; /* ARCOUNT */
p[11] = 0; /* ARCOUNT */
p = putDomainName(&p[12], "w3.org");
/* A = 1 = host address */
p[0] = 0;
p[1] = 15; /* MX = mail exchange */
p[2] = 0;
p[3] = 1; /* IN = Internet */
len = (p + 4) - buf;
buf[0] = 0;
buf[1] = len - 2;
bytesTransferred = send(fd, buf, len, 0);
if (bytesTransferred != len)
{
fprintf(stderr, "wrong number of bytes written\n");
return 1;
}
bytesTransferred = recv(fd, buf, sizeof(buf), 0);
for (i = 0; i < bytesTransferred; i++)
{
c = buf[i];
if ((0x20 <= c) && (c <= 0x7e))
{
printf("%02d: 0x%02x = '%c'\n", i, c, c);
}
else
{
printf("%02d: 0x%02x\n", i, c);
}
}
printf("%d bytes read\n", bytesTransferred);
printf("ID 0x%04x\n", (buf[2] << 8) | buf[3]);
printf("QR %d\n", buf[4] >> 7);
printf("RCODE %d\n", buf[5] & 0xf);
printf("QDCOUNT %d\n", (buf[ 6] << 8) | buf[ 7]);
printf("ANCOUNT %d\n", (buf[ 8] << 8) | buf[ 9]);
printf("NSCOUNT %d\n", (buf[10] << 8) | buf[11]);
printf("ARCOUNT %d\n", (buf[12] << 8) | buf[13]);
return 0;
}