1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * create raw socket for icmp protocol test permision
6 * and drop root privilegies if running setuid
7 *
8 */
9
10#include <sys/types.h>
11#include <netdb.h>
12#include <sys/socket.h>
13#include <errno.h>
14#include <unistd.h>
15#include "libbb.h"
16
17int create_icmp_socket(void)
18{
19	struct protoent *proto;
20	int sock;
21
22	proto = getprotobyname("icmp");
23	/* if getprotobyname failed, just silently force
24	 * proto->p_proto to have the correct value for "icmp" */
25	if ((sock = socket(AF_INET, SOCK_RAW,
26			(proto ? proto->p_proto : 1))) < 0) {        /* 1 == ICMP */
27		if (errno == EPERM)
28			error_msg_and_die("permission denied. (are you root?)");
29		else
30			perror_msg_and_die(can_not_create_raw_socket);
31	}
32
33	/* drop root privs if running setuid */
34	setuid(getuid());
35
36	return sock;
37}
38