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/*
* udp.c
*
* Copyright (c) 2001 Dug Song <dugsong@monkey.org>
*
* $Id$
*/
#include "config.h"
#include <sys/types.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "dumbnet.h"
#include "aton.h"
#include "mod.h"
void
udp_usage(void)
{
fprintf(stderr, "Usage: dnet udp [sport|dport <value>] ...\n");
exit(1);
}
int
udp_main(int argc, char *argv[])
{
struct udp_hdr *udp;
u_char *p, buf[IP_LEN_MAX]; /* XXX */
char *name, *value;
int c, len;
srand(time(NULL));
udp = (struct udp_hdr *)buf;
memset(udp, 0, sizeof(*udp));
udp->uh_sport = rand() & 0xffff;
udp->uh_dport = rand() & 0xffff;
for (c = 1; c + 1 < argc; c += 2) {
name = argv[c];
value = argv[c + 1];
if (strcmp(name, "sport") == 0) {
if (port_aton(value, &udp->uh_sport) < 0)
udp_usage();
} else if (strcmp(name, "dport") == 0) {
if (port_aton(value, &udp->uh_dport) < 0)
udp_usage();
} else
udp_usage();
}
argc -= c;
argv += c;
if (argc != 0)
udp_usage();
p = buf + UDP_HDR_LEN;
if (!isatty(STDIN_FILENO)) {
len = sizeof(buf) - (p - buf);
while ((c = read(STDIN_FILENO, p, len)) > 0) {
p += c;
len -= c;
}
}
len = p - buf;
udp->uh_ulen = htons(len);
if (write(STDOUT_FILENO, buf, len) != len)
err(1, "write");
return (0);
}
struct mod mod_udp = {
"udp",
MOD_TYPE_ENCAP,
udp_main
};
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