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/*
* Copyright (C) 2006-2019 Anders Gavare. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*
* Dumps UDP packets in hex and ASCII that arrive at a specific port.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
void dump_buf(unsigned char *p, ssize_t len)
{
while (len > 0) {
ssize_t i, n = len>=16? 16 : len;
for (i=0; i<n; i++)
printf(" %02x", p[i]);
for (i=n; i<16; i++)
printf(" ");
printf(" ");
for (i=0; i<n; i++) {
if (p[i]>=32 && p[i]<127)
printf("%c", p[i]);
else
printf(".");
}
printf("\n");
p += 16;
len -= 16;
}
}
int main(int argc, char *argv[])
{
struct sockaddr_in si;
int s;
if (argc < 2) {
fprintf(stderr, "usage: %s udp_portnr\n", argv[0]);
exit(1);
}
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("socket");
exit(1);
}
memset((char *)&si, 0, sizeof(si));
si.sin_family = AF_INET;
si.sin_port = htons(atoi(argv[1]));
si.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(s, (struct sockaddr *)&si, sizeof(si)) < 0) {
perror("bind");
exit(1);
}
for (;;) {
unsigned char buf[2048];
ssize_t r = recv(s, buf, sizeof(buf), 0);
if (r < 0) {
perror("recv");
exit(1);
}
dump_buf(buf, r);
printf("\n");
}
return 0;
}
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