busybox/libbb/create_icmp_socket.c

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * create raw socket for icmp protocol test permission
 * and drop root privileges if running setuid
 *
 */

#include <sys/types.h>
#include <netdb.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include "libbb.h"

int create_icmp_socket(void)
{
	struct protoent *proto;
	int sock;

	proto = getprotobyname("icmp");
	/* if getprotobyname failed, just silently force
	 * proto->p_proto to have the correct value for "icmp" */
	if ((sock = socket(AF_INET, SOCK_RAW,
			(proto ? proto->p_proto : 1))) < 0) {        /* 1 == ICMP */
		if (errno == EPERM)
			bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
		else
			bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
	}

	/* drop root privs if running setuid */
	xsetuid(getuid());

	return sock;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Utility routines.
4	*
5	* create raw socket for icmp protocol test permission
6	* and drop root privileges 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
17	int 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	bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
29	else
30	bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
31	}
32
33	/* drop root privs if running setuid */
34	xsetuid(getuid());
35
36	return sock;
37	}