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/* $Id: icmp_echo.c,v 1.9 2001/10/20 15:23:55 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_icmpecho_req(struct sockaddr_in to) {
return(send_icmpecho_var_req( to, IP_DF));
}
rpack_t *send_icmpecho_var_req(struct sockaddr_in to, int bits) {
int sndsock;
int res;
struct ip *ip;
struct icmp *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 (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
sizeof(on)) < 0) {
perror("IP_HDRINCL");
exit(1);
}
packlen = sizeof(struct ip) + sizeof(struct icmp) + DATA_SIZE;
if((pack = (unsigned char *)calloc( packlen, 1)) == NULL) {
perror("calloc");
exit(1);
}
ip = (struct ip *)pack;
icmp = (struct icmp *)(pack + sizeof(struct ip));
make_ippkt(ip, IPPROTO_ICMP, interf.addr, to.sin_addr,
packlen, bits, 6);
icmp->icmp_type = ICMP_ECHO;
icmp->icmp_code = 123; /* ! */
icmp->icmp_seq = rand();
icmp->icmp_id = rand();
icmp->icmp_cksum = in_cksum((unsigned short *)icmp,
DATA_SIZE + sizeof(struct icmp));
if (icmp->icmp_cksum == 0)
icmp->icmp_cksum = 0xffff;
log_message("[send]-> ICMP echo 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);
free(pack);
return NULL;
}
log_message("[%d bytes] sent, waiting for response.", res);
recv_pack = read_icmp(&res, ICMP_ECHOREPLY, -1);
if (recv_pack == NULL || res < sizeof(ip) + 8) {
fprintf(stderr,"Receive timeout. Quitting..\n");
close(sndsock);
free(pack);
return NULL;
}
if ((retval=calloc(sizeof(rpack_t), 1)) == NULL) {
perror("calloc");
exit(1);
}
retval->packsize = res;
if((retval->pkt = calloc(res, 1)) == NULL) {
perror("calloc");
exit(1);
}
memcpy((void *)retval->pkt, (void *)recv_pack, res);
#ifdef DEBUG
fprintf(stderr,"Received %d bytes packet.\n", res);
hexdump(recv_pack, res);
fprintf(stderr,"\n----\n");
hexdump(retval->pkt, res);
#endif
retval->ip = (struct ip *)retval->pkt;
/* sanity checks */
#ifdef DEBUG
fprintf(stderr, "hlen: %d\nlen: %d\n", retval->ip->ip_hl<<2, htons(retval->ip->ip_len));
#endif
if (res < sizeof(struct ip) ||
(retval->ip->ip_hl << 2) > res ||
ntohs(retval->ip->ip_len) > res ) {
fprintf(stderr,"Received maliformed packet!\n");
close(sndsock);
free(pack);
free(retval->pkt);
free(retval);
return NULL;
}
retval->icmp = (struct icmp *)((VOIDPTR_T)retval->pkt + (VOIDPTR_T)(retval->ip->ip_hl<<2));
#ifdef DEBUG
fprintf(stderr,"type: %d code: %d\n", retval->icmp->icmp_type, retval->icmp->icmp_code);
#endif
/* if (rcv_icmp->icmp_type != ICMP_ECHOREPLY) {
fprintf(stderr, "Received datagram is not ICMP echo reply\n");
close(sndsock);
close(rcvsock);
free(pack);
free(recv_pack);
return NULL;
}
*/
retval->orig_pkt = NULL;
close(sndsock);
free(pack);
return retval;
}
int wait_icmp(int sock, struct sockaddr_in *from, unsigned char *pack,
int packlen) {
struct timeval wait;
fd_set fds;
int fromlen = sizeof(*from);
ssize_t cc=0;
wait.tv_sec=receive_timeout;
wait.tv_usec=0;
FD_ZERO(&fds);
FD_SET(sock, &fds);
if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0)
cc=recvfrom(sock, (char *)pack, packlen, 0,
(struct sockaddr *)from, &fromlen);
#ifdef DEBUG
if(cc>0)
hexdump((void *)pack, cc);
#endif
return((int)cc);
}
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