embedaddon/libnet/sample/dhcp_discover.c - diff

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Diff for /embedaddon/libnet/sample/dhcp_discover.c between versions 1.1.1.1 and 1.1.1.2

version 1.1.1.1, 2012/02/21 22:14:23	version 1.1.1.2, 2013/07/22 11:54:41
Line 64 main(int argc, char *argv[])	Line 64 main(int argc, char *argv[])

char errbuf[LIBNET_ERRBUF_SIZE];	char errbuf[LIBNET_ERRBUF_SIZE];

u_char options_req[] = { LIBNET_DHCP_SUBNETMASK , LIBNET_DHCP_BROADCASTADDR , LIBNET_DHCP_TIMEOFFSET , LIBNET_DHCP_ROUTER , LIBNET_DHCP_DOMAINNAME , LIBNET_DHCP_DNS , LIBNET_DHCP_HOSTNAME };	u_char options_req[] = { LIBNET_DHCP_SUBNETMASK,
	LIBNET_DHCP_BROADCASTADDR, LIBNET_DHCP_TIMEOFFSET,
	LIBNET_DHCP_ROUTER, LIBNET_DHCP_DOMAINNAME,
	LIBNET_DHCP_DNS, LIBNET_DHCP_HOSTNAME };
u_char *options;	u_char *options;
u_char enet_dst[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};	u_char enet_dst[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
u_char *tmp;	u_char *tmp;

// have to specify interface
if (argc != 2)	if (argc != 2)
	{
usage(argv[0]);	usage(argv[0]);
	}
intf = argv[1];	intf = argv[1];

l = libnet_init(	l = libnet_init(LIBNET_LINK, intf, errbuf);
LIBNET_LINK, // injection type
intf, // network interface
errbuf); // errbuf
if (!l)	if (!l)
{	{
fprintf(stderr, "libnet_init: %s", errbuf);	fprintf(stderr, "libnet_init: %s", errbuf);
exit(EXIT_FAILURE);	exit(EXIT_FAILURE);
}	}
else {	else
	{
src_ip = libnet_get_ipaddr4(l);;	src_ip = libnet_get_ipaddr4(l);;

if ((ethaddr = libnet_get_hwaddr(l)) == NULL)	if ((ethaddr = libnet_get_hwaddr(l)) == NULL)
Line 92 main(int argc, char *argv[])	Line 94 main(int argc, char *argv[])
exit(EXIT_FAILURE);	exit(EXIT_FAILURE);
}	}

printf("ip addr : %s\n", libnet_addr2name4(src_ip, LIBNET_DONT_RESOLVE));	printf("ip addr : %s\n", libnet_addr2name4(src_ip,
	LIBNET_DONT_RESOLVE));
printf("eth addr : ");	printf("eth addr : ");
for (i = 0; i < 6; i++) {	for (i = 0; i < 6; i++)
	{
printf("%2.2x", ethaddr->ether_addr_octet[i]);	printf("%2.2x", ethaddr->ether_addr_octet[i]);
if (i != 5) {	if (i != 5)
	{
printf(":");	printf(":");
}	}
}	}
printf("\n");	printf("\n");


// build options packet	/* build options packet */
i = 0;	i = 0;
options_len = 3; // update total payload size	/* update total payload size */
	options_len = 3;

// we are a discover packet	/* we are a discover packet */
options = malloc(3);	options = malloc(3);
options[i++] = LIBNET_DHCP_MESSAGETYPE; // type	options[i++] = LIBNET_DHCP_MESSAGETYPE; /* type */
options[i++] = 1; // len	options[i++] = 1; /* len */
options[i++] = LIBNET_DHCP_MSGDISCOVER; // data	options[i++] = LIBNET_DHCP_MSGDISCOVER; /* data */

orig_len = options_len;	orig_len = options_len;
options_len += sizeof(options_req) + 2; // update total payload size	/* update total payload size */
	options_len += sizeof(options_req) + 2;

// workaround for realloc on old machines
// options = realloc(options, options_len); // resize options buffer
tmp = malloc(options_len);	tmp = malloc(options_len);
memcpy(tmp, options, orig_len);	memcpy(tmp, options, orig_len);
free(options);	free(options);
options = tmp;	options = tmp;

// we are going to request some parameters	/* we are going to request some parameters */
options[i++] = LIBNET_DHCP_PARAMREQUEST; // type	options[i++] = LIBNET_DHCP_PARAMREQUEST; /* type */
options[i++] = sizeof(options_req); // len	options[i++] = sizeof(options_req); /* len */
memcpy(options + i, options_req, sizeof(options_req)); // data	memcpy(options + i, options_req, sizeof(options_req)); /* data */
i += sizeof(options_req);	i += sizeof(options_req);

// if we have an ip already, let's request it.	/* if we have an ip already, let's request it. */
if (src_ip)	if (src_ip)
{	{
orig_len = options_len;	orig_len = options_len;
options_len += 2 + sizeof(src_ip);	options_len += 2 + sizeof(src_ip);

// workaround for realloc on old machines
// options = realloc(options, options_len);
tmp = malloc(options_len);	tmp = malloc(options_len);
memcpy(tmp, options, orig_len);	memcpy(tmp, options, orig_len);
free(options);	free(options);
options = tmp;	options = tmp;

options[i++] = LIBNET_DHCP_DISCOVERADDR; // type	options[i++] = LIBNET_DHCP_DISCOVERADDR; /* type */
options[i++] = sizeof(src_ip); // len	options[i++] = sizeof(src_ip); /* len */
memcpy(options + i, (char *)&src_ip, sizeof(src_ip));// data	memcpy(options + i, (char )&src_ip, sizeof(src_ip)); / data */
i += sizeof(src_ip);	i += sizeof(src_ip);
}	}

// end our options packet	/* end our options packet */
// workaround for realloc on old machines
// options = realloc(options, options_len); // resize options buffer
orig_len = options_len;	orig_len = options_len;
options_len += 1;	options_len += 1;
tmp = malloc(options_len);	tmp = malloc(options_len);
Line 160 main(int argc, char *argv[])	Line 161 main(int argc, char *argv[])
options[i++] = LIBNET_DHCP_END;	options[i++] = LIBNET_DHCP_END;


// make sure we are at least the minimum length, if not fill	/* make sure we are at least the minimum length, if not fill */
// this could go in libnet, but we will leave it in the app for now	/* this could go in libnet, but we will leave it in the app for now */
if (options_len + LIBNET_DHCPV4_H < LIBNET_BOOTP_MIN_LEN)	if (options_len + LIBNET_DHCPV4_H < LIBNET_BOOTP_MIN_LEN)
{	{
orig_len = options_len;	orig_len = options_len;
options_len = LIBNET_BOOTP_MIN_LEN - LIBNET_DHCPV4_H;	options_len = LIBNET_BOOTP_MIN_LEN - LIBNET_DHCPV4_H;

// workaround for realloc on old machines
// options = realloc(options, options_len);
tmp = malloc(options_len);	tmp = malloc(options_len);
memcpy(tmp, options, orig_len);	memcpy(tmp, options, orig_len);
free(options);	free(options);
Line 177 main(int argc, char *argv[])	Line 176 main(int argc, char *argv[])
memset(options + i, 0, options_len - i);	memset(options + i, 0, options_len - i);
}	}

// the goodies are here
dhcp = libnet_build_dhcpv4(	dhcp = libnet_build_dhcpv4(
LIBNET_DHCP_REQUEST, // opcode	LIBNET_DHCP_REQUEST, /* opcode */
1, // hardware type	1, /* hardware type */
6, // hardware address length	6, /* hardware address length */
0, // hop count	0, /* hop count */
0xdeadbeef, // transaction id	0xdeadbeef, /* transaction id */
0, // seconds since bootstrap	0, /* seconds since bootstrap */
0x8000, // flags	0x8000, /* flags */
0, // client ip	0, /* client ip */
0, // your ip	0, /* your ip */
0, // server ip	0, /* server ip */
0, // gateway ip	0, /* gateway ip */
ethaddr->ether_addr_octet, // client hardware addr	ethaddr->ether_addr_octet, /* client hardware addr */
NULL, // server host name	NULL, /* server host name */
NULL, // boot file	NULL, /* boot file */
options, // dhcp options stuck in payload since it is dynamic	options, /* dhcp options in payload */
options_len, // length of options	options_len, /* length of options */
l, // libnet handle	l, /* libnet context */
0); // libnet id	0); /* libnet ptag */

// wrap it
udp = libnet_build_udp(	udp = libnet_build_udp(
68, // source port	68, /* source port */
67, // destination port	67, /* destination port */
LIBNET_UDP_H + LIBNET_DHCPV4_H + options_len, // packet size	LIBNET_UDP_H + LIBNET_DHCPV4_H + options_len, /* packet size */
0, // checksum	0, /* checksum */
NULL, // payload	NULL, /* payload */
0, // payload size	0, /* payload size */
l, // libnet handle	l, /* libnet context */
0); // libnet id	0); /* libnet ptag */

// hook me up with some ipv4
ip = libnet_build_ipv4(	ip = libnet_build_ipv4(
LIBNET_IPV4_H + LIBNET_UDP_H + LIBNET_DHCPV4_H	LIBNET_IPV4_H + LIBNET_UDP_H + LIBNET_DHCPV4_H
+ options_len, // length	+ options_len, /* length */
0x10, // TOS	0x10, /* TOS */
0, // IP ID	0, /* IP ID */
0, // IP Frag	0, /* IP Frag */
16, // TTL	16, /* TTL */
IPPROTO_UDP, // protocol	IPPROTO_UDP, /* protocol */
0, // checksum	0, /* checksum */
src_ip, // src ip	src_ip, /* src ip */
inet_addr("255.255.255.255"), // destination ip	inet_addr("255.255.255.255"), /* destination ip */
NULL, // payload	NULL, /* payload */
0, // payload size	0, /* payload size */
l, // libnet handle	l, /* libnet context */
0); // libnet id	0); /* libnet ptag */

// we can just autobuild since we arent doing anything tricky
t = libnet_autobuild_ethernet(	t = libnet_autobuild_ethernet(
enet_dst, // ethernet destination	enet_dst, /* ethernet destination */
ETHERTYPE_IP, // protocol type	ETHERTYPE_IP, /* protocol type */
l); // libnet handle	l); /* libnet context */

// write to the wire
if (libnet_write(l) == -1)	if (libnet_write(l) == -1)
{	{
fprintf(stderr, " %s: libnet_write: %s\n", argv[0],	fprintf(stderr, " %s: libnet_write: %s\n", argv[0],
Line 240 main(int argc, char *argv[])	Line 234 main(int argc, char *argv[])
exit(EXIT_FAILURE);	exit(EXIT_FAILURE);
}	}

// fill and print stats
libnet_stats(l, &ls);	libnet_stats(l, &ls);
fprintf(stderr, "Packets sent: %lld\n"	fprintf(stderr, "Packets sent: %lld\n"
"Packet errors: %lld\n"	"Packet errors: %lld\n"
Line 248 main(int argc, char *argv[])	Line 241 main(int argc, char *argv[])
ls.packets_sent, ls.packet_errors, ls.bytes_written);	ls.packets_sent, ls.packet_errors, ls.bytes_written);
libnet_destroy(l);	libnet_destroy(l);

// free mem
free(options);	free(options);

exit(0);	exit(0);

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Removed from v.1.1.1.1
changed lines
	Added in v.1.1.1.2