Added DHCP option51 support and changed vlan id range for vlan option

README.txt

@@ -29,6 +29,7 @@ dhtest version 1.1 supports the following
 
 2. Support of bind timout with -k flag on command line
 
+3. Added DHCP option 51 - Requested lease time from server
 
 Authour: Saravanakumar.G
 Send your comments, enhancements and bugs to saravana815@gmail.com

dhtest.c

@@ -45,6 +45,7 @@ u_int32_t dhcp_xid = 0;
 u_int16_t bcast_flag = 0; /* DHCP broadcast flag */ 
 u_int8_t vci_buff[256] = { 0 }; /* VCI buffer*/
 u_int16_t vci_flag = 0;
+u_int32_t option51_lease_time = 0;
 
 /* Pointers for all layer data structures */
 struct ethernet_hdr *eth_hg = { 0 };
@@ -77,9 +78,10 @@ void print_help(char *cmd)
 {
     fprintf(stdout, "Usage: %s [ options ] -m mac_address\n", cmd);
     fprintf(stdout, "  -r, --release\t\t\t\t# Releases obtained DHCP IP for corresponding MAC\n");
+    fprintf(stdout, "  -L, --option51-lease_time [ Lease_time ] # Option 51. Requested lease time in secondes\n");
     fprintf(stdout, "  -I, --option50-ip\t[ IP_address ]\t# Option 50 IP address on DHCP discover\n");
     fprintf(stdout, "  -o, --option60-vci\t[ VCI_string ]\t# Vendor Class Idendifier string\n");
-    fprintf(stdout, "  -v, --vlan\t\t[ vlan_id ]\t# VLAN ID. Range(2 - 4094)\n");
+    fprintf(stdout, "  -v, --vlan\t\t[ vlan_id ]\t# VLAN ID. Range(1 - 4094)\n");
     /* fprintf(stdout, "  -x, --dhcp_xid\t[ dhcp_xid ]\n"); */
     fprintf(stdout, "  -t, --tos\t\t[ TOS_value ]\t# IP header TOS value\n");
     fprintf(stdout, "  -i, --interface\t[ interface ]\t# Interface to use. Default eth0\n");
@@ -108,6 +110,7 @@ int main(int argc, char *argv[])
 	{ "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' },
 	{ "timeout", required_argument, 0, 'T' },
@@ -121,7 +124,7 @@ int main(int argc, char *argv[])
 
     /*getopt routine to get command line arguments*/
     while(get_tmp < argc) {
-	get_cmd  = getopt_long(argc, argv, "m:i:v:t:bfVrT:I:o:k:",\
+	get_cmd  = getopt_long(argc, argv, "m:i:v:t:bfVrT:I:o:k:L:",\
 		long_options, &option_index);
 	if(get_cmd == -1 ) {
 	    break;
@@ -148,9 +151,9 @@ int main(int argc, char *argv[])
 		break;
 
 	    case 'v':
-		if(atoi(optarg) <= 1 || atoi(optarg) >= 4095)
+		if(atoi(optarg) < 1 || atoi(optarg) > 4095)
 		{
-		    fprintf(stdout, "VLAN ID is not valid. Range 2 to 4094\n");
+		    fprintf(stdout, "VLAN ID is not valid. Range 1 to 4095\n");
 		    exit(1);
 		}
 		vlan = atoi(optarg);
@@ -181,7 +184,11 @@ int main(int argc, char *argv[])
 		}
 		l3_tos = atoi(optarg);
 		break;
-		
+
+	    case 'L':
+		option51_lease_time = atoi(optarg);
+		break;
+
 	    case 'I':
 		option50_ip = inet_addr(optarg);
 		break;
@@ -260,6 +267,9 @@ int main(int argc, char *argv[])
     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  */
@@ -302,6 +312,9 @@ int main(int argc, char *argv[])
     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 */

functions.c

@@ -37,6 +37,7 @@ extern u_int32_t dhcp_xid;
 extern u_int32_t bcast_flag;
 extern u_int8_t timeout;
 extern u_int8_t vci_buff[256];
+extern u_int32_t option51_lease_time;
 
 extern struct ethernet_hdr *eth_hg;
 extern struct vlan_hdr *vlan_hg; 
@@ -459,6 +460,21 @@ int build_option50()
     return 0;
 }
 
+/*
+ * Builds DHCP option51 on dhopt_buff - DHCP lease time requested
+ */
+int build_option51()
+{
+    u_int8_t msgtype = DHCP_LEASETIME;
+    u_int8_t msglen = 4;
+    u_int32_t msg = htonl(option51_lease_time); 
+
+    memcpy((dhopt_buff + dhopt_size), &msgtype, 1);
+    memcpy((dhopt_buff + dhopt_size + 1), &msglen, 1);
+    memcpy((dhopt_buff + dhopt_size + 2), &msg, 4);
+    dhopt_size = dhopt_size + 6; 
+    return 0;
+}
 /*
  * Builds DHCP option54 on dhopt_buff
  */

headers.h

@@ -24,6 +24,7 @@ int build_option53(int msg_type);	/* Option53: MSGTYPE. Builds option53*/
 int build_option55();		/* Requested parameters list */
 int build_option54();		/* Builds server identifier on DHCP request */
 int build_option50();		/* Option50: Rqstd IP. Builds option50*/
+int build_option51();		/* Option51: Rqstd lease time. Builds option51*/
 int build_option60_vci();	/* Vendor class identifier */
 int build_optioneof();		/* End of option */