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dhtest/dhtest.c

596 lines
15 KiB

/*
* DHCP client simulation tool. For testing pursose only.
* This program needs to be run with root privileges.
* Author - Saravanakumar.G E-mail: saravana815@gmail.com
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <getopt.h>
#include <time.h>
#include <stdlib.h>
#include <signal.h>
#include "headers.h"
int iface = 2; /* Socket descripter & transmit interface index */
struct sockaddr_ll ll = { 0 }; /* Socket address structure */
u_int16_t vlan = 0;
u_int8_t l3_tos = 0;
u_int16_t l2_hdr_size = 14;
u_int16_t l3_hdr_size = 20;
u_int16_t l4_hdr_size = 8;
u_char dhmac[ETHER_ADDR_LEN] = { 0 };
int dhmac_fname_flag;
char dhmac_fname[256];
char *iface_name = "eth0";
char ip_str[128];
u_int8_t dhmac_flag = 0;
u_int32_t server_id = { 0 }, option50_ip = { 0 };
u_int32_t dhcp_xid = 0;
int bcast_flag = 0; /* DHCP broadcast flag */
const char *vci_buff;
u_int16_t vci_flag = 0;
const char *hostname_buff;
u_int16_t hostname_flag = 0;
const char *fqdn_buff;
u_int16_t fqdn_flag = 0;
u_int16_t fqdn_n = 0;
u_int16_t fqdn_s = 0;
u_int32_t option51_lease_time = 0;
u_int32_t port = 67;
u_int8_t unicast_flag = 0;
u_int8_t nagios_flag = 0;
char *giaddr = "0.0.0.0";
char *server_addr = "255.255.255.255";
struct dhcpv4_hdr *dhcph_g = { 0 };
u_int8_t verbose = 0;
u_int8_t dhcp_release_flag = 0;
u_int8_t dhcp_request_flag = 0;
u_int8_t padding_flag = 0;
int timeout = 0;
static time_t time_now, time_last;
time_t lease_expires_at;
u_int32_t unicast_ip_address = 0;
u_int32_t ip_address;
u_char ip_listen_flag = 0;
struct timeval tval_listen = { 3600, 0 };
u_int32_t listen_timeout = 3600;
int quiet;
/* Help routine for the command line interface */
void print_help(char *cmd)
{
printf("Usage: %s [ options ]\n", cmd);
printf(" -m\t\t\t\t\t# MAC_address\n");
printf(" -R, --random-mac\t\t\t# Use a randomly generated MAC address\n");
printf(" -r, --release\t\t\t\t# Releases obtained DHCP IP for corresponding MAC\n");
printf(" -F, --log-filename\t\t\t# Log/status file, defaults to './$MAC'\n");
printf(" -L, --option51-lease_time [ Lease_time ] # Option 51. Requested lease time in secondes\n");
printf(" -I, --option50-ip\t[ IP_address ]\t# Option 50 IP address on DHCP discover\n");
printf(" -o, --option60-vci\t[ VCI_string ]\t# Vendor Class Idendifier string\n");
printf(" -h, --option12-hostname [ hostname_string ] # Client hostname string\n");
printf(" -v, --vlan\t\t[ vlan_id ]\t# VLAN ID. Range(1 - 4094)\n");
/* printf(" -x, --dhcp_xid\t[ dhcp_xid ]\n"); */
printf(" -t, --tos\t\t[ TOS_value ]\t# IP header TOS value\n");
printf(" -i, --interface\t[ interface ]\t# Interface to use. Default eth0\n");
printf(" -T, --timeout\t\t[ cmd_timeout ]\t# Command returns within specified timout in seconds\n");
printf(" -b, --bind-ip\t\t\t\t# Listens on the obtained IP. Supported protocols - ARP and ICMP\n");
printf(" -k, --bind-timeout\t[ timeout ]\t# Listen timout in seconds. Default 3600 seconds\n");
printf(" -f, --bcast_flag\t\t\t# Sets broadcast flag on DHCP discover and request\n");
printf(" -d, --fqdn-domain-name [ fqdn ]\t# FQDN domain name to use\n");
printf(" -n, --fqdn-server-not-update\t\t# Sets FQDN server not update flag\n");
printf(" -s, --fqdn-server-update-a\t\t# Sets FQDN server update flag\n");
printf(" -p, --padding\t\t\t\t# Add padding to packet to be at least 300 bytes\n");
printf(" -P, --port\t\t[ port ]\t# Use port instead of 67\n");
printf(" -g, --giaddr\t\t[ giaddr ]\t# Use giaddr instead of 0.0.0.0\n");
printf(" -u<ip>, --unicast=<ip>\t\t# Unicast request, IP is optional. If not specified, the interface address will be used. \n");
printf(" -a, --nagios\t\t\t\t# Nagios output format. \n");
printf(" -S, --server\t\t[ address ]\t# Use server address instead of 255.255.255.255\n");
printf(" -V, --verbose\t\t\t\t# Prints DHCP offer and ack details\n");
printf(" -q, --quiet\t\t\t\t# Only print acquired IP address or errors\n");
printf(" -Q, --request-only\t\t\t\t# Refresh previous acquired lease by sending a request\n");
printf(" dhtest version 1.3\n");
}
static void cleanup(void) {
clear_promisc();
}
static void sigcleanup(int sig) {
fprintf(stderr, "signal %s received, exiting\n", strsignal(sig));
cleanup();
exit(0);
}
static void sigabort(int sig) {
signal(SIGABRT, SIG_DFL);
fprintf(stderr, "signal %s received, aborting\n", strsignal(sig));
cleanup();
abort();
}
int main(int argc, char *argv[])
{
int get_tmp = 1, get_cmd;
int dhinfo_ret;
if(argc < 3) {
print_help(argv[0]);
exit(2);
}
init_rand();
atexit(cleanup);
signal(SIGSEGV, sigabort);
signal(SIGABRT, sigabort);
signal(SIGTERM, sigcleanup);
signal(SIGINT, sigcleanup);
signal(SIGHUP, sigcleanup);
int option_index = 0;
static struct option long_options[] = {
{ "mac", required_argument, 0, 'm' },
{ "random-mac", no_argument, 0, 'R' },
{ "log-filename", required_argument, 0, 'F' },
{ "interface", required_argument, 0, 'i' },
{ "vlan", required_argument, 0, 'v' },
{ "dhcp_xid", required_argument, 0, 'x' },
{ "tos", required_argument, 0, 't' },
{ "option51-lease_time", required_argument, 0, 'L' },
{ "option50-ip", required_argument, 0, 'I' },
{ "option60-vci", required_argument, 0, 'o' },
{ "option12-hostname", required_argument, 0, 'h' },
{ "timeout", required_argument, 0, 'T' },
{ "bind-ip", no_argument, 0, 'b' },
{ "bind-timeout", required_argument, 0, 'k' },
{ "bcast_flag", no_argument, 0, 'f'},
{ "verbose", no_argument, 0, 'V'},
{ "fqdn-server-not-update", no_argument, 0, 'n'},
{ "fqdn-server-update-a", no_argument, 0, 's'},
{ "fqdn-domain-name", required_argument, 0, 'd'},
{ "padding", no_argument, 0, 'p'},
{ "port", required_argument, 0, 'P'},
{ "giaddr", required_argument, 0, 'g'},
{ "unicast", optional_argument, 0, 'u'},
{ "nagios", no_argument, 0, 'a'},
{ "server", required_argument, 0, 'S'},
{ "release", no_argument, 0, 'r'},
{ "quiet", no_argument, 0, 'q'},
{ "request-only", no_argument, 0, 'Q'},
{ 0, 0, 0, 0 }
};
/*getopt routine to get command line arguments*/
while(get_tmp < argc) {
get_cmd = getopt_long(argc, argv, "m:Ri:v:t:bfVrpansu::T:P:g:S:I:o:k:L:h:d:F:qQ",\
long_options, &option_index);
if(get_cmd == -1 ) {
break;
}
switch(get_cmd) {
case 'q':
quiet = 1;
break;
case 'm':
{
u_char aux_dhmac[ETHER_ADDR_LEN + 1];
if(strlen(optarg) != 17
|| sscanf(optarg, ETH_F_FMT, ETH_F_PARG(aux_dhmac)) != 6
)
{
fprintf(stderr, "Invalid mac address\n");
exit(2);
}
memcpy(dhmac, aux_dhmac, sizeof(dhmac));
dhmac_flag = 1;
}
break;
case 'R':
{
int i;
for (i = 0; i < ETHER_ADDR_LEN; i++)
dhmac[i] = rand() & 0xff;
/* clear multicast bit, set the L bit, clear MSB */
dhmac[0] &= ~0x81;
dhmac[0] |= 0x02;
dhmac_flag = 1;
}
break;
case 'F':
if (strlen(optarg) > sizeof(dhmac_fname) - 1) {
fprintf(stderr, "-F filename given is too long\n");
exit(2);
}
strcpy(dhmac_fname, optarg);
dhmac_fname_flag = 1;
break;
case 'i':
iface_name = optarg;
break;
case 'v':
if(atoi(optarg) < 1 || atoi(optarg) > 4095)
{
fprintf(stderr, "VLAN ID is not valid. Range 1 to 4095\n");
exit(2);
}
vlan = atoi(optarg);
l2_hdr_size = 18;
break;
case 'r':
dhcp_release_flag = 1;
break;
case 'Q':
dhcp_request_flag = 1;
break;
case 'b':
ip_listen_flag = 1;
break;
case 'k':
listen_timeout = atoi(optarg);
tval_listen.tv_sec = listen_timeout;
break;
case 'x':
{
u_int32_t aux_dhcp_xid[2];
aux_dhcp_xid[0] = 0;
sscanf((char *)optarg, "%X", &aux_dhcp_xid[0]);
dhcp_xid = aux_dhcp_xid[0];
}
break;
case 't':
if(atoi(optarg) >= 256 || atoi(optarg) < 0) {
fprintf(stderr, "Invalid TOS value\n");
exit(2);
}
l3_tos = atoi(optarg);
break;
case 'L':
option51_lease_time = atoi(optarg);
break;
case 'I':
option50_ip = inet_addr(optarg);
break;
case 'o':
if(strlen(optarg) >= 256) {
fprintf(stderr, "VCI string size should be less than 256\n");
exit(2);
}
vci_flag = 1;
vci_buff = optarg;
break;
case 'h':
if(strlen(optarg) >= 256) {
fprintf(stderr, "Hostname string size should be less than 256\n");
exit(2);
}
hostname_flag = 1;
hostname_buff = optarg;
break;
case 'd':
if(strlen(optarg) >= 253) {
fprintf(stderr, "FQDN domain name string size should be less than 253\n");
exit(2);
}
fqdn_flag = 1;
fqdn_buff = optarg;
break;
case 'n':
fqdn_n = 1;
break;
case 's':
fqdn_s = 1;
break;
case 'T':
if(atoi(optarg) < 5 || atoi(optarg) > 3600) {
fprintf(stderr, "Invalid timout value. Range 5 to 3600\n");
exit(2);
}
timeout = atoi(optarg);
break;
case 'P':
if(atoi(optarg) <=0 || atoi(optarg) > 65535) {
fprintf(stderr, "Invalid port value. Range 1 to 65535\n");
exit(2);
}
port = atoi(optarg);
break;
case 'g':
giaddr = optarg;
break;
case 'S':
server_addr = optarg;
break;
case 'p':
padding_flag = 1;
break;
case 'f':
bcast_flag = htons(0x8000);
break;
case 'V':
verbose = 1;
break;
case 'u':
if (optarg) {
struct in_addr out;
if (!inet_aton(optarg, &out)) {
fprintf(stderr, "Invalid unicast IP address.");
exit(2);
}
unicast_ip_address = out.s_addr;
}
unicast_flag = 1;
break;
case 'a':
nagios_flag = 1;
break;
default:
exit(2);
}
get_tmp++;
}
if(!dhmac_flag) {
print_help(argv[0]);
exit(2);
}
if (!dhmac_fname_flag)
sprintf(dhmac_fname, ETH_F_FMT, ETH_F_ARG(dhmac));
dhinfo_ret = get_dhinfo();
iface = if_nametoindex(iface_name);
if(iface == 0) {
fprintf(stderr, "Interface %s does not exist\n", iface_name);
exit(2);
}
/* Opens the PF_PACKET socket */
if(open_socket() < 0)
critical("Socket error: %m");
/* Sets the promiscuous mode */
set_promisc();
if (unicast_flag && !unicast_ip_address) {
unicast_ip_address = get_interface_address();
}
/* Sets a random DHCP xid */
set_rand_dhcp_xid();
time_now = time_last = time(NULL);
/*
* If DHCP release flag is set, send DHCP release packet
* and exit. get_dhinfo parses the DHCP info from log file
* and unlinks it from the system
*/
if(dhcp_release_flag) {
if(dhinfo_ret)
critical("Error on opening DHCP info file: %s", strerror(dhinfo_ret));
if (!server_id)
critical("Can't release IP without an active lease");
build_option53(DHCP_MSGRELEASE); /* Option53 DHCP release */
if(hostname_flag) {
build_option12_hostname();
}
if(fqdn_flag) {
build_option81_fqdn();
}
build_option54(); /* Server id */
build_optioneof(); /* End of option */
build_dhpacket(DHCP_MSGRELEASE); /* Build DHCP release packet */
send_packet(DHCP_MSGRELEASE); /* Send DHCP release packet */
/* update status file: we no longer have our IP address */
log_dhinfo();
return 0;
}
if (dhcp_request_flag) {
if(dhinfo_ret)
critical("Error on opening DHCP info file: %s", strerror(dhinfo_ret));
if (!server_id)
critical("Can't refresh IP without an active lease");
/* Clients begin to attempt to renew their leases once half the lease interval has expired. */
if (lease_expires_at - time_now > option51_lease_time / 2)
return 0;
goto request;
}
build_option53(DHCP_MSGDISCOVER); /* Option53 for DHCP discover */
if(hostname_flag) {
build_option12_hostname();
}
if(fqdn_flag) {
build_option81_fqdn();
}
if(option50_ip) {
build_option50(); /* Option50 - req. IP */
}
if(option51_lease_time) {
build_option51(); /* Option51 - DHCP lease time requested */
}
if(vci_flag == 1) {
build_option60_vci(); /* Option60 - VCI */
}
build_optioneof(); /* End of option */
build_dhpacket(DHCP_MSGDISCOVER); /* Build DHCP discover packet */
int dhcp_offer_state = 0;
while(dhcp_offer_state != DHCP_OFFR_RCVD) {
/* Sends DHCP discover packet */
send_packet(DHCP_MSGDISCOVER);
/*
* recv_packet functions returns when the specified
* packet is received
*/
dhcp_offer_state = recv_packet(DHCP_MSGOFFER);
if(timeout) {
time_now = time(NULL);
if((time_now - time_last) > timeout)
critical("Timeout reached: DISCOVER");
}
if(dhcp_offer_state == DHCP_OFFR_RCVD) {
if (!nagios_flag && !quiet)
printf("DHCP offer received\t - ");
set_serv_id_opt50();
if (!nagios_flag && !quiet)
printf("Offered IP : %s\n", get_ip_str(dhcph_g->dhcp_yip));
if(!nagios_flag && verbose) {
print_dhinfo(DHCP_MSGOFFER);
}
}
}
request:
/* Reset the dhopt buffer to build DHCP request options */
reset_dhopt_size();
build_option53(DHCP_MSGREQUEST);
build_option50();
build_option54();
if(hostname_flag) {
build_option12_hostname();
}
if(fqdn_flag) {
build_option81_fqdn();
}
if(vci_flag == 1) {
build_option60_vci();
}
if(option51_lease_time) {
build_option51(); /* Option51 - DHCP lease time requested */
}
build_option55();
build_optioneof();
build_dhpacket(DHCP_MSGREQUEST); /* Builds specified packet */
int dhcp_ack_state = 1;
int retries = 3;
while(dhcp_ack_state != DHCP_ACK_RCVD) {
send_packet(DHCP_MSGREQUEST);
dhcp_ack_state = recv_packet(DHCP_MSGACK);
if(timeout) {
time_now = time(NULL);
if((time_now - time_last) > timeout)
critical("Timeout reached: REQUEST");
}
if(dhcp_ack_state == DHCP_ACK_RCVD) {
if (nagios_flag) {
printf("OK: Acquired IP: %s", get_ip_str(dhcph_g->dhcp_yip));
} else if (!quiet) {
printf("DHCP ack received\t - ");
printf("Acquired IP: %s\n", get_ip_str(dhcph_g->dhcp_yip));
}
else {
/* quiet */
printf("%s\n", get_ip_str(dhcph_g->dhcp_yip));
}
/* Logs DHCP IP details to log file. This file is used for DHCP release */
log_dhinfo();
if(!nagios_flag && verbose) {
print_dhinfo(DHCP_MSGACK);
}
break;
}
if (dhcp_ack_state == DHCP_NAK_RCVD) {
if (!nagios_flag && !quiet) {
printf("DHCP nack received\t - ");
printf("Client MAC : %02x:%02x:%02x:%02x:%02x:%02x\n", \
dhmac[0], dhmac[1], dhmac[2], dhmac[3], dhmac[4], dhmac[5]);
}
}
if (--retries <= 0) {
printf("Failure - exit\n");
exit(2);
}
sleep(1);
}
/* If IP listen flag is enabled, Listen on obtained for ARP, ICMP protocols */
if(!nagios_flag && ip_listen_flag) {
if (!quiet) {
printf("\nListening on %s for ARP and ICMP protocols\n", iface_name);
printf("IP address: %s, Listen timeout: %d seconds\n", get_ip_str(htonl(ip_address)), listen_timeout);
}
int arp_icmp_rcv_state = 0;
while(arp_icmp_rcv_state != LISTEN_TIMEOUT) {
arp_icmp_rcv_state = recv_packet(ARP_ICMP_RCV);
/* Send ARP reply if ARP request received */
if(arp_icmp_rcv_state == ARP_RCVD) {
/*if(verbose) {
printf("ARP request received\n");
printf("Sending ARP reply\n");
}*/
build_packet(ARP_SEND);
send_packet(ARP_SEND);
} else if(arp_icmp_rcv_state == ICMP_RCVD) {
/* Send ICMP reply if ICMP echo request received */
/*if(verbose) {
printf("ICMP request received\n");
printf("Sending ICMP reply\n");
}*/
build_packet(ICMP_SEND);
send_packet(ICMP_SEND);
}
}
printf("Listen timout reached\n");
}
return 0;
}