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/*
* ping-module for bscan.
* IDEA: add record-route and source-route feature
* and -p pattern [where can we save our time-struct then ?
*/
#include <bscan/bscan.h>
#include <bscan/module.h>
#include <bscan/system.h>
#include <stdio.h>
#ifndef MOD_NAME
#define MOD_NAME "mod_ping"
#endif
static int process_rcv(struct _opt *);
static int isinit=0;
/*
* some variables from the binary-process
*/
extern int dlt_len;
extern u_char *align_buf;
extern unsigned short ip_options;
extern struct ip *ip;
extern struct Ether_header *eth;
extern u_int plen, pcaplen;
extern struct timeval *pts;
struct _mopt
{
int type;
int size;
} static mopt;
/*
* static functions prototypes
*/
static int mdo_opt(int, char **, struct _opt *);
static void init_vars(struct _opt *);
/*
* print out usage informations
*/
void
musage()
{
printf ("\n"MOD_NAME"\n");
printf (" -t (echo|time) -s <size>, size of ping-data [default 56].\n");
}
/*
* return 0 on success, != 0 on failure
*/
int
init(char **modname, int argc, char *argv[], struct _opt *opt)
{
#ifdef DEBUG
printf("MODULE INIT\n");
#endif
if (isinit)
return(-1);
*modname = MOD_NAME;
isinit = 1;
init_vars(opt);
if (mdo_opt(argc, argv, opt) != 0)
return(-1);
return(0);
}
/*
* fini-routine. called on cleanup
*/
int
fini()
{
#ifdef DEBUG
printf("MODULE FINI\n");
#endif
return(0);
}
/*
* Module entry point [entry]
* RMOD_OK: everything allright. send the packet out [if first]
* or do nothing [MOD_RCV].
* RMOD_SKIP: proceed with next IP without sending out the packet.
*/
int
callmdl(int entry, struct _opt *opt)
{
#ifdef DEBUG
printf("MODULE CALLMDL\n");
#endif
if (entry == MOD_FIRSTPKG)
{
add_icmpping (opt->packet + ETH_SIZE + IP_SIZE, mopt.size, mopt.type);
add_iphdr (opt->packet + ETH_SIZE, IPPROTO_ICMP, &opt->nt, ICMP_SIZE + mopt.size);
opt->pkg_len = IP_SIZE + ICMP_SIZE + mopt.size;
return(RMOD_OK);
}
if (entry == MOD_RCV)
process_rcv(opt);
return(RMOD_OK);
}
/*
***********************************************************
* Our OWN/static functions for THIS module *
***********************************************************
*/
/*
* initialize all local variables.
* We use some 'unused' variables of the masterprogramm
*/
static void
init_vars(struct _opt *opt)
{
mopt.size = ICMP_ECHO;
mopt.size = 56;
}
/*
* LOCAL/STATIC function, only available in the module
* return 0 on success, != 0 on failure
*/
static int
mdo_opt(int argc, char *argv[], struct _opt *opt)
{
extern char *optarg;
/*extern int optind, opterr, optopt;*/
int c;
while ((c = getopt (argc, argv, "t:s:")) != -1)
{
switch (c)
{
case 't':
if (strcasecmp (optarg, "echo") == 0)
mopt.type = ICMP_ECHO;
else if (strcasecmp (optarg, "time") == 0)
mopt.type = ICMP_TSTAMP;
else
return (-1);
break;
case 's':
mopt.size = atoi(optarg);
break;
case ':':
fprintf(stderr, "missing parameter\n");
return(-1);
default:
return(-1);
}
}
return(0);
}
/*
* handle incoming icmp ECHO_REPLY packages
*/
static int
process_rcv(struct _opt *opt)
{
struct icmp *icmp;
struct timeval now;
double rrt;
if (ip->ip_p != IPPROTO_ICMP)
return(0);
if (plen < dlt_len + IP_SIZE + ip_options + sizeof(*icmp))
return(0); /* invalid size */
icmp = (struct icmp *) (align_buf + IP_SIZE + ip_options);
// if ((icmp->icmp_type != 0) || (icmp->icmp_code != 0))
// return(0);
memcpy(&now, pts, sizeof(now));
time_diff((struct timeval *)icmp->icmp_dun.id_data, &now);
rrt = now.tv_sec * 1000.0 + now.tv_usec / 1000.0;
printf("%d bytes from %s: icmp_seq=%u ttl=%d time=%.3f ms\n",
(int)(plen - dlt_len - IP_SIZE - ip_options),
int_ntoa(ip->ip_src.s_addr), icmp->icmp_hun.ih_idseq.icd_seq,
ip->ip_ttl, rrt);
return(0);
}
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