int main(int argc, char *argv[])
{
int get_tmp = 1, get_cmd;
if(argc < 3) {
print_help(argv[0]);
exit(1);
}
int option_index = 0;
static struct option long_options[] = {
{ "mac", required_argument, 0, 'm' },
{ "interface", required_argument, 0, 'i' },
{ "vlan", required_argument, 0, 'v' },
{ "dhcp_xid", required_argument, 0, 'x' },
{ "tos", required_argument, 0, 't' },
{ "option12-name", required_argument, 0, 'n' },
{ "option51-lease_time", required_argument, 0, 'L' },
{ "option50-ip", required_argument, 0, 'I' },
{ "option60-vci", required_argument, 0, 'o' },
{ "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'},
{ "write-log", no_argument, 0, 'W'},
{ "release", no_argument, 0, 'r'},
{ 0, 0, 0, 0 }
};
/*getopt routine to get command line arguments*/
while(get_tmp < argc) {
get_cmd = getopt_long(argc, argv, "m:i:v:t:bfVWrT:I:o:k:L:n:",\
long_options, &option_index);
if(get_cmd == -1 ) {
break;
}
switch(get_cmd) {
case 'm':
if(strlen(optarg) > 18) {
fprintf(stdout, "Invalid mac address\n");
exit(1);
}
strcpy(dhmac_fname, optarg);
sscanf((char *)optarg, "%2hhX:%2hhX:%2hhX:%2hhX:%2hhX:%2hhX", &dhmac[0], \
&dhmac[1], &dhmac[2], &dhmac[3], &dhmac[4], &dhmac[5]);
dhmac_flag = 1;
break;
case 'i':
iface = if_nametoindex(optarg);
if(iface == 0) {
fprintf(stdout, "Interface doesnot exist\n");
exit(1);
}
strncpy(iface_name, optarg, 29);
break;
case 'v':
if(atoi(optarg) < 1 || atoi(optarg) > 4095)
{
fprintf(stdout, "VLAN ID is not valid. Range 1 to 4095\n");
exit(1);
}
vlan = atoi(optarg);
l2_hdr_size = 18;
break;
case 'r':
dhcp_release_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':
sscanf((char *)optarg, "%X", &dhcp_xid);
break;
case 't':
if(atoi(optarg) >= 256 || atoi(optarg) < 0) {
fprintf(stdout, "Invalid TOS value\n");
exit(1);
}
l3_tos = atoi(optarg);
break;
case 'L':
option51_lease_time = atoi(optarg);
break;
case 'I':
option50_ip = inet_addr(optarg);
break;
case 'n':
strncpy(option12_name, optarg, sizeof(option12_name));
break;
case 'o':
if(strlen(optarg) > 256) {
fprintf(stdout, "VCI string size should be less than 256\n");
exit(1);
}
vci_flag = 1;
memcpy(vci_buff, optarg, sizeof(vci_buff));
break;
case 'T':
if(atoi(optarg) < 5 || atoi(optarg) > 3600) {
fprintf(stdout, "Invalid timout value. Range 5 to 3600\n");
exit(1);
}
timeout = atoi(optarg);
break;
case 'f':
bcast_flag = htons(0x8000);
break;
case 'V':
verbose = 1;
break;
case 'W':
writelog = 1;
break;
default:
exit(1);
}
get_tmp++;
}
if(!dhmac_flag) {
print_help(argv[0]);
exit(1);
}
/* Opens the PF_PACKET socket */
if(open_socket() < 0) {
fprintf(stdout, "Socket error\n");
exit(1);
}
/* Sets the promiscuous mode */
set_promisc();
/* Sets a random DHCP xid */
set_rand_dhcp_xid();
/*
* 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(get_dhinfo() == ERR_FILE_OPEN) {
fprintf(stdout, "Error on opening DHCP info file\n");
fprintf(stdout, "Release the DHCP IP after acquiring\n");
exit(1);
}
build_option53(DHCP_MSGRELEASE); /* Option53 DHCP release */
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 */
clear_promisc(); /* Clear the promiscuous mode */
close_socket();
return 0;
}
if(timeout) {
time_last = time(NULL);
}
build_option53(DHCP_MSGDISCOVER); /* Option53 for DHCP discover */
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;
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) {
close_socket();
exit(1);
}
}
if(dhcp_offer_state == DHCP_OFFR_RCVD) {
fprintf(stdout, "DHCP offer received\t - ");
set_serv_id_opt50();
fprintf(stdout, "Offered IP : %s\n", inet_ntoa(*(struct in_addr *)&dhcph_g->dhcp_yip));
if(verbose) {
print_dhinfo(DHCP_MSGOFFER);
}
}
}
/* Reset the dhopt buffer to build DHCP request options */
reset_dhopt_size();
build_option53(DHCP_MSGREQUEST);
build_option50();
build_option54();
if(vci_flag == 1) {
build_option60_vci();
}
if(strlen(option12_name) > 0) {
build_option12(); /* Option 12 - Client ID (hostname) */
}
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;
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) {
fprintf(stdout, "Timeout reached. Exiting\n");
close_socket();
exit(1);
}
}
if(dhcp_ack_state == DHCP_ACK_RCVD) {
fprintf(stdout, "DHCP ack received\t - ");
fprintf(stdout, "Acquired IP: %s\n", inet_ntoa(*(struct in_addr *)&dhcph_g->dhcp_yip));
/* Logs DHCP IP details to log file. This file is used for DHCP release */
if(writelog) {
log_dhinfo();
}
if(verbose) {
print_dhinfo(DHCP_MSGACK);
}
} else if (dhcp_ack_state == DHCP_NAK_RCVD) {
fprintf(stdout, "DHCP nack received\t - ");
fprintf(stdout, "Client MAC : %02x:%02x:%02x:%02x:%02x:%02x\n", \
dhmac[0], dhmac[1], dhmac[2], dhmac[3], dhmac[4], dhmac[5]);
}
}
/* If IP listen flag is enabled, Listen on obtained for ARP, ICMP protocols */
if(ip_listen_flag) {
struct in_addr taddr;
taddr.s_addr=htonl(ip_address);
fprintf(stdout, "\nListening on %s for ARP and ICMP protocols\n", iface_name);
fprintf(stdout, "IP address: %s, Listen timeout: %d seconds\n", inet_ntoa(taddr), listen_timeout);
int arp_icmp_rcv_state = 0;
while(arp_icmp_rcv_state != LISTEN_TIMOUET) {
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) {
fprintf(stdout, "ARP request received\n");
fprintf(stdout, "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) {
fprintf(stdout, "ICMP request received\n");
fprintf(stdout, "Sending ICMP reply\n");
}*/
build_packet(ICMP_SEND);
send_packet(ICMP_SEND);
}
}
fprintf(stdout, "Listen timout reached\n");
}
/* Clear the promiscuous mode */
clear_promisc();
/* Close the socket */
close_socket();
return 0;
}
int main(int argc, char *argv[])
{
int get_tmp = 1, get_cmd;
if(argc < 3) {
print_help(argv[0]);
exit(2);
}
int option_index = 0;
static struct option long_options[] = {
{ "mac", required_argument, 0, 'm' },
{ "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'},
{ 0, 0, 0, 0 }
};
/*getopt routine to get command line arguments*/
while(get_tmp < argc) {
get_cmd = getopt_long(argc, argv, "m:i:v:t:bfVrpansu::T:P:g:S:I:o:k:L:h:d:",\
long_options, &option_index);
if(get_cmd == -1 ) {
break;
}
switch(get_cmd) {
case 'm':
{
u_char aux_dhmac[ETHER_ADDR_LEN + 1];
if(strlen(optarg) > 18) {
fprintf(stdout, "Invalid mac address\n");
exit(2);
}
strcpy(dhmac_fname, optarg);
sscanf((char *)optarg, "%2X:%2X:%2X:%2X:%2X:%2X",
(u_int32_t *) &aux_dhmac[0], (u_int32_t *) &aux_dhmac[1],
(u_int32_t *) &aux_dhmac[2], (u_int32_t *) &aux_dhmac[3],
(u_int32_t *) &aux_dhmac[4], (u_int32_t *) &aux_dhmac[5]);
memcpy(dhmac, aux_dhmac, sizeof(dhmac));
dhmac_flag = 1;
}
break;
case 'i':
iface = if_nametoindex(optarg);
if(iface == 0) {
fprintf(stdout, "Interface doesnot exist\n");
exit(2);
}
strncpy(iface_name, optarg, 29);
break;
case 'v':
if(atoi(optarg) < 1 || atoi(optarg) > 4095)
{
fprintf(stdout, "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 '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(stdout, "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(stdout, "VCI string size should be less than 256\n");
exit(2);
}
vci_flag = 1;
memcpy(vci_buff, optarg, sizeof(vci_buff));
break;
case 'h':
if(strlen(optarg) > 256) {
fprintf(stdout, "Hostname string size should be less than 256\n");
exit(2);
}
hostname_flag = 1;
memcpy(hostname_buff, optarg, sizeof(hostname_buff));
break;
case 'd':
if(strlen(optarg) > 256) {
fprintf(stdout, "FQDN domain name string size should be less than 256\n");
exit(2);
}
fqdn_flag = 1;
memcpy(fqdn_buff, optarg, sizeof(fqdn_buff));
break;
case 'n':
fqdn_n = 1;
break;
case 's':
fqdn_s = 1;
break;
case 'T':
if(atoi(optarg) < 5 || atoi(optarg) > 3600) {
fprintf(stdout, "Invalid timout value. Range 5 to 3600\n");
exit(2);
}
timeout = atoi(optarg);
break;
case 'P':
if(atoi(optarg) <=0 || atoi(optarg) > 65535) {
fprintf(stdout, "Invalid portt 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(stdout, "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);
}
/* Opens the PF_PACKET socket */
if(open_socket() < 0) {
if (nagios_flag)
fprintf(stdout, "CRITICAL: Socket error.");
else
fprintf(stdout, "Socket error\n");
exit(2);
}
/* 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();
/*
* 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(get_dhinfo() == ERR_FILE_OPEN) {
if (nagios_flag) {
fprintf(stdout, "CRITICAL: Error on opening DHCP info file.");
} else {
fprintf(stdout, "Error on opening DHCP info file\n");
fprintf(stdout, "Release the DHCP IP after acquiring\n");
}
exit(2);
}
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 */
clear_promisc(); /* Clear the promiscuous mode */
close_socket();
return 0;
}
if(timeout) {
time_last = time(NULL);
}
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) {
if (nagios_flag)
fprintf(stdout, "CRITICAL: Timeout reached: DISCOVER.");
close_socket();
exit(2);
}
}
if(dhcp_offer_state == DHCP_OFFR_RCVD) {
if (!nagios_flag)
fprintf(stdout, "DHCP offer received\t - ");
set_serv_id_opt50();
if (!nagios_flag)
fprintf(stdout, "Offered IP : %s\n", get_ip_str(dhcph_g->dhcp_yip));
if(!nagios_flag && verbose) {
print_dhinfo(DHCP_MSGOFFER);
}
}
}
/* 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;
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) {
if (nagios_flag)
fprintf(stdout, "CRITICAL: Timeout reached: REQUEST.");
else
fprintf(stdout, "Timeout reached. Exiting\n");
close_socket();
exit(1);
}
}
if(dhcp_ack_state == DHCP_ACK_RCVD) {
if (nagios_flag) {
fprintf(stdout, "OK: Acquired IP: %s", get_ip_str(dhcph_g->dhcp_yip));
} else {
fprintf(stdout, "DHCP ack received\t - ");
fprintf(stdout, "Acquired IP: %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);
}
} else if (dhcp_ack_state == DHCP_NAK_RCVD) {
if (!nagios_flag) {
fprintf(stdout, "DHCP nack received\t - ");
fprintf(stdout, "Client MAC : %02x:%02x:%02x:%02x:%02x:%02x\n", \
dhmac[0], dhmac[1], dhmac[2], dhmac[3], dhmac[4], dhmac[5]);
}
}
}
/* If IP listen flag is enabled, Listen on obtained for ARP, ICMP protocols */
if(!nagios_flag && ip_listen_flag) {
fprintf(stdout, "\nListening on %s for ARP and ICMP protocols\n", iface_name);
fprintf(stdout, "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_TIMOUET) {
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) {
fprintf(stdout, "ARP request received\n");
fprintf(stdout, "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) {
fprintf(stdout, "ICMP request received\n");
fprintf(stdout, "Sending ICMP reply\n");
}*/
build_packet(ICMP_SEND);
send_packet(ICMP_SEND);
}
}
fprintf(stdout, "Listen timout reached\n");
}
/* Clear the promiscuous mode */
clear_promisc();
/* Close the socket */
close_socket();
return 0;
}
static void cleanup(void) {
clear_promisc();
}
