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/* $Id: icmp_addrmask.c,v 1.7 2001/10/14 18:28:27 fygrave Exp $ */
/*
** Copyright (C) 2001 Fyodor Yarochkin <fygrave@tigerteam.net>,
** Ofir Arkin <ofir@sys-security.com>
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** All material for nonprofit, educational use only.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "xprobe.h"
rpack_t *send_icmpmaskreq_req(struct sockaddr_in to) {
int sndsock, rcvsock;
int res;
struct protoent *pe;
struct sockaddr_in from;
struct ip *ip, *rcv_ip;
struct icmp *icmp, *rcv_icmp;
unsigned char *pack, *recv_pack;
int on = 1;
int packlen;
rpack_t *retval = NULL;
if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0) {
perror("Can not open raw socket:");
exit(1);
}
if ((pe = getprotobyname("icmp")) == NULL) {
fprintf(stderr, "icmp: unknown protocol");
exit(1);
}
if ((rcvsock = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0) {
perror("icmp socket");
exit(1);
}
if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
sizeof(on)) < 0) {
perror("IP_HDRINCL");
exit(1);
}
packlen = sizeof(struct ip) + sizeof(struct icmp);
pack = (unsigned char *)calloc( packlen, 1);
if (pack == NULL) {
perror("calloc");
return NULL;
}
ip = (struct ip *)pack;
icmp = (struct icmp *)(pack + sizeof(struct ip));
make_ippkt(ip, IPPROTO_ICMP, interf.addr, to.sin_addr,
packlen, 0, 0);
icmp->icmp_type = ICMP_MASKREQ;
icmp->icmp_code = 0;
icmp->icmp_seq = rand();
icmp->icmp_cksum = in_cksum((unsigned short *)icmp,
packlen - sizeof(struct ip));
if (icmp->icmp_cksum == 0)
icmp->icmp_cksum = 0xffff;
log_message("[send]-> ICMP address mask request to %s ",
inet_ntoa(to.sin_addr));
res = sendto(sndsock, (void *)pack, packlen,
0, (struct sockaddr *)&to, sizeof(struct sockaddr));
if (res <0) {
perror("sendto:");
close(sndsock);
close(rcvsock);
free(pack);
return NULL;
}
log_message("[%d bytes] sent, waiting for response.", res);
recv_pack=calloc(PACKBUF_SIZ+1, 1);
res = wait_icmp(rcvsock, &from, recv_pack, PACKBUF_SIZ);
if (res == 0 || res < 0 ) {
if (res < 0)
perror("Receive error:");
else
log_message("Receive timeout. Quitting..\n");
close(sndsock);
close(rcvsock);
free(pack);
free(recv_pack);
return NULL;
}
#ifdef DEBUG
fprintf(stderr, "Received %d bytes packet.\n", res);
#endif
rcv_ip = (struct ip *)recv_pack;
/* sanity checks */
#ifdef DEBUG
fprintf(stderr, "hlen: %d\nlen: %d\n", rcv_ip->ip_hl<<2, rcv_ip->ip_len);
#endif
if (res < sizeof(struct ip) ||
(rcv_ip->ip_hl << 2) > res ||
#ifdef __linux__
ntohs(rcv_ip->ip_len)
#else
(rcv_ip->ip_len)
#endif
> res ) {
fprintf(stderr,"Received maliformed packet!\n");
close(sndsock);
close(rcvsock);
free(pack);
free(recv_pack);
return NULL;
}
rcv_icmp = (struct icmp *)(recv_pack + (rcv_ip->ip_hl<<2));
#ifdef DEBUG
fprintf(stderr,"type: %d code: %d\n", rcv_icmp->icmp_type, rcv_icmp->icmp_code);
#endif
if ((retval=calloc(sizeof(rpack_t), 1)) == NULL) {
perror("calloc");
exit(1);
}
retval->packsize = res;
retval->pkt = recv_pack;
retval->ip = rcv_ip;
retval->icmp = rcv_icmp;
retval->orig_pkt = NULL;
close(sndsock);
close(rcvsock);
free(pack);
return retval;
}
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