Code

Standardize the extra-opts notes
[nagiosplug.git] / plugins-root / check_dhcp.c
index cec44b57a39cd2f203b0e2458d0aa9e286b77dd5..ba35197ef96bf9b1d9557ea46b9e13a26839211c 100644 (file)
@@ -1,41 +1,47 @@
-/******************************************************************************
-*
-* CHECK_DHCP.C
-*
-* Program: DHCP plugin for Nagios
+/*****************************************************************************
+* 
+* Nagios check_dhcp plugin
+* 
 * License: GPL
 * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)
-* Copyright (c) 2001-2006 Nagios Plugin Development Team
-*
-* License Information:
-*
-* This program is free software; you can redistribute it and/or modify
+* Copyright (c) 2001-2007 Nagios Plugin Development Team
+* 
+* Description:
+* 
+* This file contains the check_dhcp plugin
+* 
+* This plugin tests the availability of DHCP servers on a network.
+* 
+* Unicast mode was originally implemented by Heiti of Boras Kommun with
+* general improvements as well as usability fixes and "forward"-porting by
+* Andreas Ericsson of OP5 AB.
+* 
+* 
+* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
-* the Free Software Foundation; either version 2 of the License, or
+* the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
-*
+* 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
-*
+* 
 * You should have received a copy of the GNU General Public License
-* along with this program; if not, write to the Free Software
-* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*
-* $Id$
-*
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+* 
+* 
 *****************************************************************************/
 
 const char *progname = "check_dhcp";
-const char *revision = "$Revision$";
-const char *copyright = "2001-2006";
+const char *copyright = "2001-2007";
 const char *email = "nagiosplug-devel@lists.sourceforge.net";
 
 #include "common.h"
 #include "netutils.h"
 #include "utils.h"
 
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -51,6 +57,9 @@ const char *email = "nagiosplug-devel@lists.sourceforge.net";
 #include <netinet/in.h>
 #include <net/if.h>
 #include <arpa/inet.h>
+#if HAVE_SYS_SOCKIO_H
+#include <sys/sockio.h>
+#endif
 
 #if defined( __linux__ )
 
@@ -60,13 +69,14 @@ const char *email = "nagiosplug-devel@lists.sourceforge.net";
 #elif defined (__bsd__)
 
 #include <netinet/if_ether.h>
+#include <sys/param.h>
 #include <sys/sysctl.h>
 #include <net/if_dl.h>
 
 #elif defined(__sun__) || defined(__solaris__) || defined(__hpux__)
 
-#define INSAP 22 
-#define OUTSAP 24 
+#define INSAP 22
+#define OUTSAP 24
 
 #include <signal.h>
 #include <ctype.h>
@@ -76,17 +86,17 @@ const char *email = "nagiosplug-devel@lists.sourceforge.net";
 
 #define bcopy(source, destination, length) memcpy(destination, source, length)
 
-#define AREA_SZ 5000           /* buffer length in bytes */ 
+#define AREA_SZ 5000           /* buffer length in bytes */
 static u_long ctl_area[AREA_SZ];
 static u_long dat_area[AREA_SZ];
 static struct strbuf ctl = {AREA_SZ, 0, (char *)ctl_area};
 static struct strbuf dat = {AREA_SZ, 0, (char *)dat_area};
 
-#define GOT_CTRL 1 
-#define GOT_DATA 2 
-#define GOT_BOTH 3 
-#define GOT_INTR 4 
-#define GOT_ERR 128 
+#define GOT_CTRL 1
+#define GOT_DATA 2
+#define GOT_BOTH 3
+#define GOT_INTR 4
+#define GOT_ERR 128
 
 #define u_int8_t        uint8_t
 #define u_int16_t      uint16_t
@@ -152,6 +162,7 @@ typedef struct dhcp_offer_struct{
 
 typedef struct requested_server_struct{
        struct in_addr server_address;
+       int answered;
        struct requested_server_struct *next;
         }requested_server;
 
@@ -172,8 +183,10 @@ typedef struct requested_server_struct{
 #define DHCP_OPTION_BROADCAST_ADDRESS   28
 #define DHCP_OPTION_REQUESTED_ADDRESS   50
 #define DHCP_OPTION_LEASE_TIME          51
+#define DHCP_OPTION_SERVER_IDENTIFIER   54
 #define DHCP_OPTION_RENEWAL_TIME        58
 #define DHCP_OPTION_REBINDING_TIME      59
+#define DHCP_OPTION_END                 255
 
 #define DHCP_INFINITE_TIME              0xFFFFFFFF
 
@@ -185,7 +198,11 @@ typedef struct requested_server_struct{
 #define ETHERNET_HARDWARE_ADDRESS            1     /* used in htype field of dhcp packet */
 #define ETHERNET_HARDWARE_ADDRESS_LENGTH     6     /* length of Ethernet hardware addresses */
 
+u_int8_t unicast = 0;        /* unicast mode: mimic a DHCP relay */
+struct in_addr my_ip;        /* our address (required for relay) */
+struct in_addr dhcp_ip;      /* server to query (if in unicast mode) */
 unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH]="";
+unsigned char *user_specified_mac=NULL;
 
 char network_interface_name[IFNAMSIZ]="eth0";
 
@@ -201,7 +218,7 @@ dhcp_offer *dhcp_offer_list=NULL;
 requested_server *requested_server_list=NULL;
 
 int valid_responses=0;     /* number of valid DHCPOFFERs we received */
-int requested_servers=0;   
+int requested_servers=0;
 int requested_responses=0;
 
 int request_specific_address=FALSE;
@@ -216,7 +233,11 @@ int validate_arguments(void);
 void print_usage(void);
 void print_help(void);
 
+void resolve_host(const char *in,struct in_addr *out);
+unsigned char *mac_aton(const char *);
+void print_hardware_address(const unsigned char *);
 int get_hardware_address(int,char *);
+int get_ip_address(int,char *);
 
 int send_dhcp_discover(int);
 int get_dhcp_offer(int);
@@ -241,16 +262,28 @@ int main(int argc, char **argv){
        setlocale (LC_ALL, "");
        bindtextdomain (PACKAGE, LOCALEDIR);
        textdomain (PACKAGE);
-       
+
+       /* Parse extra opts if any */
+       argv=np_extra_opts(&argc, argv, progname);
+
        if(process_arguments(argc,argv)!=OK){
                usage4 (_("Could not parse arguments"));
                }
 
+       /* this plugin almost certainly needs root permissions. */
+       np_warn_if_not_root();
+
        /* create socket for DHCP communications */
        dhcp_socket=create_dhcp_socket();
 
        /* get hardware address of client machine */
-       get_hardware_address(dhcp_socket,network_interface_name);
+       if(user_specified_mac!=NULL)
+               memcpy(client_hardware_address,user_specified_mac,6);
+       else
+               get_hardware_address(dhcp_socket,network_interface_name);
+
+       if(unicast) /* get IP address of client machine */
+               get_ip_address(dhcp_socket,network_interface_name);
 
        /* send DHCPDISCOVER packet */
        send_dhcp_discover(dhcp_socket);
@@ -276,13 +309,12 @@ int main(int argc, char **argv){
 /* determines hardware address on client machine */
 int get_hardware_address(int sock,char *interface_name){
 
-       int i;
-
 #if defined(__linux__)
        struct ifreq ifr;
 
-       strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name));
-       
+       strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name)-1);
+       ifr.ifr_name[sizeof(ifr.ifr_name)-1]='\0';
+
        /* try and grab hardware address of requested interface */
        if(ioctl(sock,SIOCGIFHWADDR,&ifr)<0){
                 printf(_("Error: Could not get hardware address of interface '%s'\n"),interface_name);
@@ -306,25 +338,25 @@ int get_hardware_address(int sock,char *interface_name){
         mib[3] = AF_LINK;
         mib[4] = NET_RT_IFLIST;
 
-        if ((mib[5] = if_nametoindex(interface_name)) == 0) {
+        if((mib[5] = if_nametoindex(interface_name)) == 0){
                 printf(_("Error: if_nametoindex error - %s.\n"), strerror(errno));
                 exit(STATE_UNKNOWN);
-        }
+               }
 
-        if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
+        if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0){
                 printf(_("Error: Couldn't get hardware address from %s. sysctl 1 error - %s.\n"), interface_name, strerror(errno));
                 exit(STATE_UNKNOWN);
-        }
+               }
 
-        if ((buf = malloc(len)) == NULL) {
+        if((buf = malloc(len)) == NULL){
                 printf(_("Error: Couldn't get hardware address from interface %s. malloc error - %s.\n"), interface_name, strerror(errno));
                 exit(4);
-        }
+               }
 
-        if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
+        if(sysctl(mib, 6, buf, &len, NULL, 0) < 0){
                 printf(_("Error: Couldn't get hardware address from %s. sysctl 2 error - %s.\n"), interface_name, strerror(errno));
                 exit(STATE_UNKNOWN);
-        }
+               }
 
         ifm = (struct if_msghdr *)buf;
         sdl = (struct sockaddr_dl *)(ifm + 1);
@@ -340,21 +372,22 @@ int get_hardware_address(int sock,char *interface_name){
        char *p;
        int unit;
 
-       for (p = interface_name; *p && isalpha(*p); p++)
+       for(p = interface_name; *p && isalpha(*p); p++)
                /* no-op */ ;
-       if ( p != '\0' ) {
+       if( p != '\0' ){
                unit = atoi(p) ;
                *p = '\0' ;
                strncat(dev, interface_name, 6) ;
-       } else {
+               }
+       else{
                printf(_("Error: can't find unit number in interface_name (%s) - expecting TypeNumber eg lnc0.\n"), interface_name);
                exit(STATE_UNKNOWN);
-       }
+               }
        stat = mac_addr_dlpi(dev, unit, client_hardware_address);
-       if (stat != 0) {
+       if(stat != 0){
                printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit);
                exit(STATE_UNKNOWN);
-       }
+               }
 
 #elif defined(__hpux__)
 
@@ -363,32 +396,55 @@ int get_hardware_address(int sock,char *interface_name){
        int unit = 0;
 
        stat = mac_addr_dlpi(dev, unit, client_hardware_address);
-       if (stat != 0) {
+       if(stat != 0){
                printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit);
                exit(STATE_UNKNOWN);
-       }
+               }
                                                /* Kompf 2000-2003 */
 
 #else
-       printf(_("Error: can't get MAC address for this architecture.\n"));
+       printf(_("Error: can't get MAC address for this architecture.  Use the --mac option.\n"));
        exit(STATE_UNKNOWN);
 #endif
 
-       if (verbose) { 
-               printf(_("Hardware address: "));
-               for (i=0; i<6; ++i)
-                       printf("%2.2x", client_hardware_address[i]);
-               printf( "\n");
-       }
+       if(verbose)
+               print_hardware_address(client_hardware_address);
 
        return OK;
         }
 
+/* determines IP address of the client interface */
+int get_ip_address(int sock,char *interface_name){
+#if defined(SIOCGIFADDR)
+       struct ifreq ifr;
+
+       strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name)-1);
+       ifr.ifr_name[sizeof(ifr.ifr_name)-1]='\0';
+
+       if(ioctl(sock,SIOCGIFADDR,&ifr)<0){
+               printf(_("Error: Cannot determine IP address of interface %s\n"),
+                       interface_name);
+               exit(STATE_UNKNOWN);
+               }
+
+       my_ip=((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr;
+
+#else
+       printf(_("Error: Cannot get interface IP address on this platform.\n"));
+       exit(STATE_UNKNOWN);
+#endif
+
+       if(verbose)
+               printf(_("Pretending to be relay client %s\n"),inet_ntoa(my_ip));
+
+       return OK;
+       }
 
 /* sends a DHCPDISCOVER broadcast message in an attempt to find DHCP servers */
 int send_dhcp_discover(int sock){
        dhcp_packet discover_packet;
        struct sockaddr_in sockaddr_broadcast;
+    unsigned short opts;
 
 
        /* clear the packet data structure */
@@ -404,9 +460,10 @@ int send_dhcp_discover(int sock){
        /* length of our hardware address */
        discover_packet.hlen=ETHERNET_HARDWARE_ADDRESS_LENGTH;
 
-       discover_packet.hops=0;
-
-       /* transaction id is supposed to be random */
+       /*
+        * transaction ID is supposed to be random.  We won't use the address so
+        * we don't care about high entropy here.  time(2) is good enough.
+        */
        srand(time(NULL));
        packet_xid=random();
        discover_packet.xid=htonl(packet_xid);
@@ -418,8 +475,11 @@ int send_dhcp_discover(int sock){
        /*discover_packet.secs=htons(65535);*/
        discover_packet.secs=0xFF;
 
-       /* tell server it should broadcast its response */ 
-       discover_packet.flags=htons(DHCP_BROADCAST_FLAG);
+       /*
+        * server needs to know if it should broadcast or unicast its response:
+        * 0x8000L == 32768 == 1 << 15 == broadcast, 0 == unicast
+        */
+       discover_packet.flags = unicast ? 0 : htons(DHCP_BROADCAST_FLAG);
 
        /* our hardware address */
        memcpy(discover_packet.chaddr,client_hardware_address,ETHERNET_HARDWARE_ADDRESS_LENGTH);
@@ -430,38 +490,48 @@ int send_dhcp_discover(int sock){
        discover_packet.options[2]='\x53';
        discover_packet.options[3]='\x63';
 
+    opts = 4;
        /* DHCP message type is embedded in options field */
-       discover_packet.options[4]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
-       discover_packet.options[5]='\x01';               /* DHCP message option length in bytes */
-       discover_packet.options[6]=DHCPDISCOVER;
+       discover_packet.options[opts++]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
+       discover_packet.options[opts++]='\x01';               /* DHCP message option length in bytes */
+       discover_packet.options[opts++]=DHCPDISCOVER;
 
        /* the IP address we're requesting */
        if(request_specific_address==TRUE){
-               discover_packet.options[7]=DHCP_OPTION_REQUESTED_ADDRESS;
-               discover_packet.options[8]='\x04';
-               memcpy(&discover_packet.options[9],&requested_address,sizeof(requested_address));
+               discover_packet.options[opts++]=DHCP_OPTION_REQUESTED_ADDRESS;
+               discover_packet.options[opts++]='\x04';
+               memcpy(&discover_packet.options[opts],&requested_address,sizeof(requested_address));
+               opts += sizeof(requested_address);
                }
-       
+       discover_packet.options[opts++]=DHCP_OPTION_END;
+
+       /* unicast fields */
+       if(unicast)
+               discover_packet.giaddr.s_addr = my_ip.s_addr;
+
+       /* see RFC 1542, 4.1.1 */
+       discover_packet.hops = unicast ? 1 : 0;
+
        /* send the DHCPDISCOVER packet to broadcast address */
         sockaddr_broadcast.sin_family=AF_INET;
         sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
-        sockaddr_broadcast.sin_addr.s_addr=INADDR_BROADCAST;
+       sockaddr_broadcast.sin_addr.s_addr = unicast ? dhcp_ip.s_addr : INADDR_BROADCAST;
        bzero(&sockaddr_broadcast.sin_zero,sizeof(sockaddr_broadcast.sin_zero));
 
 
-       if (verbose) {
+       if(verbose){
                printf(_("DHCPDISCOVER to %s port %d\n"),inet_ntoa(sockaddr_broadcast.sin_addr),ntohs(sockaddr_broadcast.sin_port));
-               printf("DHCPDISCOVER XID: %lu (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
+               printf("DHCPDISCOVER XID: %u (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
                printf("DHCDISCOVER ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
                printf("DHCDISCOVER yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
                printf("DHCDISCOVER siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
                printf("DHCDISCOVER giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
-       }
+               }
 
        /* send the DHCPDISCOVER packet out */
        send_dhcp_packet(&discover_packet,sizeof(discover_packet),sock,&sockaddr_broadcast);
 
-       if (verbose) 
+       if(verbose)
                printf("\n\n");
 
        return OK;
@@ -474,8 +544,8 @@ int send_dhcp_discover(int sock){
 int get_dhcp_offer(int sock){
        dhcp_packet offer_packet;
        struct sockaddr_in source;
+       struct sockaddr_in via;
        int result=OK;
-       int timeout=1;
        int responses=0;
        int x;
        time_t start_time;
@@ -490,79 +560,90 @@ int get_dhcp_offer(int sock){
                if((current_time-start_time)>=dhcpoffer_timeout)
                        break;
 
-               if (verbose) 
+               if(verbose)
                        printf("\n\n");
 
                bzero(&source,sizeof(source));
+               bzero(&via,sizeof(via));
                bzero(&offer_packet,sizeof(offer_packet));
 
                result=OK;
                result=receive_dhcp_packet(&offer_packet,sizeof(offer_packet),sock,dhcpoffer_timeout,&source);
-               
+
                if(result!=OK){
-                       if (verbose)
+                       if(verbose)
                                printf(_("Result=ERROR\n"));
 
                        continue;
                        }
                else{
-                       if (verbose) 
+                       if(verbose)
                                printf(_("Result=OK\n"));
 
                        responses++;
                        }
 
-               if (verbose) {
-                       printf(_("DHCPOFFER from IP address %s\n"),inet_ntoa(source.sin_addr));
-                       printf("DHCPOFFER XID: %lu (0x%X)\n",ntohl(offer_packet.xid),ntohl(offer_packet.xid));
-               }
+               /* The "source" is either a server or a relay. */
+               /* Save a copy of "source" into "via" even if it's via itself */
+               memcpy(&via,&source,sizeof(source)) ;
+
+               /* If siaddr is non-zero, set "source" to siaddr */
+               if(offer_packet.siaddr.s_addr != 0L){
+                       source.sin_addr.s_addr = offer_packet.siaddr.s_addr ;
+                       }
+
+               if(verbose){
+                       printf(_("DHCPOFFER from IP address %s"),inet_ntoa(source.sin_addr));
+                       printf(_(" via %s\n"),inet_ntoa(via.sin_addr));
+                       printf("DHCPOFFER XID: %u (0x%X)\n",ntohl(offer_packet.xid),ntohl(offer_packet.xid));
+                       }
 
                /* check packet xid to see if its the same as the one we used in the discover packet */
                if(ntohl(offer_packet.xid)!=packet_xid){
-                       if (verbose)
-                               printf(_("DHCPOFFER XID (%lu) did not match DHCPDISCOVER XID (%lu) - ignoring packet\n"),ntohl(offer_packet.xid),packet_xid);
+                       if(verbose)
+                               printf(_("DHCPOFFER XID (%u) did not match DHCPDISCOVER XID (%u) - ignoring packet\n"),ntohl(offer_packet.xid),packet_xid);
 
                        continue;
                        }
 
                /* check hardware address */
                result=OK;
-               if (verbose)
+               if(verbose)
                        printf("DHCPOFFER chaddr: ");
 
                for(x=0;x<ETHERNET_HARDWARE_ADDRESS_LENGTH;x++){
-                       if (verbose)
+                       if(verbose)
                                printf("%02X",(unsigned char)offer_packet.chaddr[x]);
 
                        if(offer_packet.chaddr[x]!=client_hardware_address[x])
                                result=ERROR;
-               }
-               if (verbose)
+                       }
+               if(verbose)
                        printf("\n");
 
                if(result==ERROR){
-                       if (verbose) 
+                       if(verbose)
                                printf(_("DHCPOFFER hardware address did not match our own - ignoring packet\n"));
 
                        continue;
                        }
 
-               if (verbose) {
+               if(verbose){
                        printf("DHCPOFFER ciaddr: %s\n",inet_ntoa(offer_packet.ciaddr));
                        printf("DHCPOFFER yiaddr: %s\n",inet_ntoa(offer_packet.yiaddr));
                        printf("DHCPOFFER siaddr: %s\n",inet_ntoa(offer_packet.siaddr));
                        printf("DHCPOFFER giaddr: %s\n",inet_ntoa(offer_packet.giaddr));
-               }
+                       }
 
                add_dhcp_offer(source.sin_addr,&offer_packet);
 
                valid_responses++;
                }
 
-       if (verbose) {
+       if(verbose){
                printf(_("Total responses seen on the wire: %d\n"),responses);
                printf(_("Valid responses for this machine: %d\n"),valid_responses);
-       }
+               }
 
        return OK;
         }
@@ -571,12 +652,11 @@ int get_dhcp_offer(int sock){
 
 /* sends a DHCP packet */
 int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in *dest){
-       struct sockaddr_in myname;
        int result;
 
        result=sendto(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)dest,sizeof(*dest));
 
-       if (verbose) 
+       if(verbose)
                printf(_("send_dhcp_packet result: %d\n"),result);
 
        if(result<0)
@@ -591,22 +671,26 @@ int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in
 int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, struct sockaddr_in *address){
         struct timeval tv;
         fd_set readfds;
+       fd_set oobfds;
        int recv_result;
        socklen_t address_size;
        struct sockaddr_in source_address;
+       int nfound;
 
 
         /* wait for data to arrive (up time timeout) */
         tv.tv_sec=timeout;
         tv.tv_usec=0;
         FD_ZERO(&readfds);
+        FD_ZERO(&oobfds);
         FD_SET(sock,&readfds);
-        select(sock+1,&readfds,NULL,NULL,&tv);
+        FD_SET(sock,&oobfds);
+        nfound = select(sock+1,&readfds,NULL,&oobfds,&tv);
 
         /* make sure some data has arrived */
         if(!FD_ISSET(sock,&readfds)){
-               if (verbose)
-                       printf(_("No (more) data received\n"));
+               if(verbose)
+                       printf(_("No (more) data received (nfound: %d)\n"), nfound);
                 return ERROR;
                 }
 
@@ -617,24 +701,24 @@ int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, st
                bzero(&source_address,sizeof(source_address));
                address_size=sizeof(source_address);
                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,MSG_PEEK,(struct sockaddr *)&source_address,&address_size);
-               if (verbose)
+               if(verbose)
                        printf("recv_result_1: %d\n",recv_result);
                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)&source_address,&address_size);
-               if (verbose)
+               if(verbose)
                        printf("recv_result_2: %d\n",recv_result);
 
                 if(recv_result==-1){
-                       if (verbose) {
+                       if(verbose){
                                printf(_("recvfrom() failed, "));
                                printf("errno: (%d) -> %s\n",errno,strerror(errno));
-                       }
+                               }
                         return ERROR;
                         }
                else{
-                       if (verbose) {
+                       if(verbose){
                                printf(_("receive_dhcp_packet() result: %d\n"),recv_result);
                                printf(_("receive_dhcp_packet() source: %s\n"),inet_ntoa(source_address.sin_addr));
-                       }
+                               }
 
                        memcpy(address,&source_address,sizeof(source_address));
                        return OK;
@@ -655,8 +739,9 @@ int create_dhcp_socket(void){
         /* Set up the address we're going to bind to. */
        bzero(&myname,sizeof(myname));
         myname.sin_family=AF_INET;
-        myname.sin_port=htons(DHCP_CLIENT_PORT);
-        myname.sin_addr.s_addr=INADDR_ANY;                 /* listen on any address */
+        /* listen to DHCP server port if we're in unicast mode */
+        myname.sin_port = htons(unicast ? DHCP_SERVER_PORT : DHCP_CLIENT_PORT);
+        myname.sin_addr.s_addr = unicast ? my_ip.s_addr : INADDR_ANY;
         bzero(&myname.sin_zero,sizeof(myname.sin_zero));
 
         /* create a socket for DHCP communications */
@@ -666,7 +751,7 @@ int create_dhcp_socket(void){
                exit(STATE_UNKNOWN);
                }
 
-       if (verbose)
+       if(verbose)
                printf("DHCP socket: %d\n",sock);
 
         /* set the reuse address flag so we don't get errors when restarting */
@@ -677,21 +762,23 @@ int create_dhcp_socket(void){
                }
 
         /* set the broadcast option - we need this to listen to DHCP broadcast messages */
-        if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
+        if(!unicast && setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
                printf(_("Error: Could not set broadcast option on DHCP socket!\n"));
                exit(STATE_UNKNOWN);
                }
 
        /* bind socket to interface */
 #if defined(__linux__)
-       strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ);
+       strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ-1);
+       interface.ifr_ifrn.ifrn_name[IFNAMSIZ-1]='\0';
        if(setsockopt(sock,SOL_SOCKET,SO_BINDTODEVICE,(char *)&interface,sizeof(interface))<0){
                printf(_("Error: Could not bind socket to interface %s.  Check your privileges...\n"),network_interface_name);
                exit(STATE_UNKNOWN);
                }
 
 #else
-       strncpy(interface.ifr_name,network_interface_name,IFNAMSIZ);
+       strncpy(interface.ifr_name,network_interface_name,IFNAMSIZ-1);
+       interface.ifr_name[IFNAMSIZ-1]='\0';
 #endif
 
         /* bind the socket */
@@ -722,13 +809,14 @@ int add_requested_server(struct in_addr server_address){
                return ERROR;
 
        new_server->server_address=server_address;
+       new_server->answered=FALSE;
 
        new_server->next=requested_server_list;
        requested_server_list=new_server;
 
        requested_servers++;
 
-       if (verbose)
+       if(verbose)
                printf(_("Requested server address: %s\n"),inet_ntoa(new_server->server_address));
 
        return OK;
@@ -741,9 +829,9 @@ int add_requested_server(struct in_addr server_address){
 int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
        dhcp_offer *new_offer;
        int x;
-       int y;
        unsigned option_type;
        unsigned option_length;
+       struct in_addr serv_ident = {0};
 
        if(offer_packet==NULL)
                return ERROR;
@@ -761,32 +849,34 @@ int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
                /* get option length */
                option_length=offer_packet->options[x++];
 
-               if (verbose) 
+               if(verbose)
                        printf("Option: %d (0x%02X)\n",option_type,option_length);
 
                /* get option data */
-        if(option_type==DHCP_OPTION_LEASE_TIME) {
-            memcpy(&dhcp_lease_time, &offer_packet->options[x],
-                sizeof(dhcp_lease_time));
-            dhcp_lease_time = ntohl(dhcp_lease_time);
-        }
-        if(option_type==DHCP_OPTION_RENEWAL_TIME) {
-            memcpy(&dhcp_renewal_time, &offer_packet->options[x],
-                sizeof(dhcp_renewal_time));
-            dhcp_renewal_time = ntohl(dhcp_renewal_time);
-        }
-        if(option_type==DHCP_OPTION_REBINDING_TIME) {
-            memcpy(&dhcp_rebinding_time, &offer_packet->options[x],
-                sizeof(dhcp_rebinding_time));
-            dhcp_rebinding_time = ntohl(dhcp_rebinding_time);
-        }
+               switch(option_type){
+               case DHCP_OPTION_LEASE_TIME:
+                       memcpy(&dhcp_lease_time, &offer_packet->options[x],sizeof(dhcp_lease_time));
+                       dhcp_lease_time = ntohl(dhcp_lease_time);
+                       break;
+               case DHCP_OPTION_RENEWAL_TIME:
+                       memcpy(&dhcp_renewal_time, &offer_packet->options[x],sizeof(dhcp_renewal_time));
+                       dhcp_renewal_time = ntohl(dhcp_renewal_time);
+                       break;
+               case DHCP_OPTION_REBINDING_TIME:
+                       memcpy(&dhcp_rebinding_time, &offer_packet->options[x],sizeof(dhcp_rebinding_time));
+                       dhcp_rebinding_time = ntohl(dhcp_rebinding_time);
+                       break;
+               case DHCP_OPTION_SERVER_IDENTIFIER:
+                       memcpy(&serv_ident.s_addr, &offer_packet->options[x],sizeof(serv_ident.s_addr));
+                       break;
+                       }
 
                /* skip option data we're ignoring */
-               else
-                       for(y=0;y<option_length;y++,x++);
-               }
+               if(option_type!=DHCP_OPTION_REBINDING_TIME)
+                       x+=option_length;
+               }
 
-       if (verbose) {
+       if(verbose){
                if(dhcp_lease_time==DHCP_INFINITE_TIME)
                        printf(_("Lease Time: Infinite\n"));
                else
@@ -798,24 +888,36 @@ int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
                if(dhcp_rebinding_time==DHCP_INFINITE_TIME)
                        printf(_("Rebinding Time: Infinite\n"));
                printf(_("Rebinding Time: %lu seconds\n"),(unsigned long)dhcp_rebinding_time);
-       }
+               }
 
        new_offer=(dhcp_offer *)malloc(sizeof(dhcp_offer));
 
        if(new_offer==NULL)
                return ERROR;
 
-       new_offer->server_address=source;
+       /*
+        * RFC 2131 (2.) says: "DHCP clarifies the interpretation of the
+        * 'siaddr' field as the address of the server to use in the next step
+        * of the client's bootstrap process.  A DHCP server may return its own
+        * address in the 'siaddr' field, if the server is prepared to supply
+        * the next bootstrap service (e.g., delivery of an operating system
+        * executable image).  A DHCP server always returns its own address in
+        * the 'server identifier' option."  'serv_ident' is the 'server
+        * identifier' option, 'source' is the 'siaddr' field or (if 'siaddr'
+        * wasn't available) the IP address we received the DHCPOFFER from.  If
+        * 'serv_ident' isn't available for some reason, we use 'source'.
+        */
+       new_offer->server_address=serv_ident.s_addr?serv_ident:source;
        new_offer->offered_address=offer_packet->yiaddr;
        new_offer->lease_time=dhcp_lease_time;
        new_offer->renewal_time=dhcp_renewal_time;
        new_offer->rebinding_time=dhcp_rebinding_time;
 
 
-       if (verbose) {
+       if(verbose){
                printf(_("Added offer from server @ %s"),inet_ntoa(new_offer->server_address));
                printf(_(" of IP address %s\n"),inet_ntoa(new_offer->offered_address));
-       }
+               }
 
        /* add new offer to head of list */
        new_offer->next=dhcp_offer_list;
@@ -848,7 +950,7 @@ int free_requested_server_list(void){
                next_server=this_server->next;
                free(this_server);
                }
-       
+
        return OK;
         }
 
@@ -873,18 +975,24 @@ int get_results(void){
                                /* get max lease time we were offered */
                                if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
                                        max_lease_time=temp_offer->lease_time;
-                               
+
                                /* see if we got the address we requested */
                                if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
                                        received_requested_address=TRUE;
 
                                /* see if the servers we wanted a response from talked to us or not */
                                if(!memcmp(&temp_offer->server_address,&temp_server->server_address,sizeof(temp_server->server_address))){
-       if (verbose) {
-                                       printf(_("DHCP Server Match: Offerer=%s"),inet_ntoa(temp_offer->server_address));
-                                       printf(_(" Requested=%s\n"),inet_ntoa(temp_server->server_address));
-       }                                      
-                                       requested_responses++;
+                                       if(verbose){
+                                               printf(_("DHCP Server Match: Offerer=%s"),inet_ntoa(temp_offer->server_address));
+                                               printf(_(" Requested=%s"),inet_ntoa(temp_server->server_address));
+                                               if(temp_server->answered)
+                                                       printf(_(" (duplicate)"));
+                                               printf(_("\n"));
+                                               }
+                                       if(temp_server->answered == FALSE){
+                                               requested_responses++;
+                                               temp_server->answered=TRUE;
+                                               }
                                        }
                                }
                        }
@@ -899,7 +1007,7 @@ int get_results(void){
                        /* get max lease time we were offered */
                        if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
                                max_lease_time=temp_offer->lease_time;
-                               
+
                        /* see if we got the address we requested */
                        if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
                                received_requested_address=TRUE;
@@ -916,14 +1024,14 @@ int get_results(void){
        else if(request_specific_address==TRUE && received_requested_address==FALSE)
                result=STATE_WARNING;
 
-    if(result==0)               /* garrett honeycutt 2005 */
-        printf("OK: ");
-    else if(result==1)
-        printf("WARNING: ");
-    else if(result==2)
-        printf("CRITICAL: ");
-    else if(result==3)
-        printf("UNKNOWN: ");
+       if(result==0)               /* garrett honeycutt 2005 */
+               printf("OK: ");
+       else if(result==1)
+               printf("WARNING: ");
+       else if(result==2)
+               printf("CRITICAL: ");
+       else if(result==3)
+               printf("UNKNOWN: ");
 
        /* we didn't receive any DHCPOFFERs */
        if(dhcp_offer_list==NULL){
@@ -975,15 +1083,16 @@ int process_arguments(int argc, char **argv){
 int call_getopt(int argc, char **argv){
        int c=0;
        int i=0;
-       struct in_addr ipaddress;
 
        int option_index = 0;
        static struct option long_options[] =
-       { 
+       {
                {"serverip",       required_argument,0,'s'},
                {"requestedip",    required_argument,0,'r'},
                {"timeout",        required_argument,0,'t'},
                {"interface",      required_argument,0,'i'},
+               {"mac",            required_argument,0,'m'},
+               {"unicast",        no_argument,      0,'u'},
                {"verbose",        no_argument,      0,'v'},
                {"version",        no_argument,      0,'V'},
                {"help",           no_argument,      0,'h'},
@@ -991,7 +1100,7 @@ int call_getopt(int argc, char **argv){
        };
 
        while(1){
-               c=getopt_long(argc,argv,"+hVvt:s:r:t:i:",long_options,&option_index);
+               c=getopt_long(argc,argv,"+hVvt:s:r:t:i:m:u",long_options,&option_index);
 
                i++;
 
@@ -1012,23 +1121,13 @@ int call_getopt(int argc, char **argv){
                switch(c){
 
                case 's': /* DHCP server address */
-                       if(inet_aton(optarg,&ipaddress))
-                               add_requested_server(ipaddress);
-                       /*
-                       else
-                               usage("Invalid server IP address\n");
-                       */
+                       resolve_host(optarg,&dhcp_ip);
+                       add_requested_server(dhcp_ip);
                        break;
 
                case 'r': /* address we are requested from DHCP servers */
-                       if(inet_aton(optarg,&ipaddress)){
-                               requested_address=ipaddress;
-                               request_specific_address=TRUE;
-                               }
-                       /*
-                       else
-                               usage("Invalid requested IP address\n");
-                       */
+                       resolve_host(optarg,&requested_address);
+                       request_specific_address=TRUE;
                        break;
 
                case 't': /* timeout */
@@ -1044,6 +1143,15 @@ int call_getopt(int argc, char **argv){
                        */
                        break;
 
+               case 'm': /* MAC address */
+
+                       if((user_specified_mac=mac_aton(optarg)) == NULL)
+                               usage("Cannot parse MAC address.\n");
+                       if(verbose)
+                               print_hardware_address(user_specified_mac);
+
+                       break;
+
                case 'i': /* interface name */
 
                        strncpy(network_interface_name,optarg,sizeof(network_interface_name)-1);
@@ -1051,8 +1159,12 @@ int call_getopt(int argc, char **argv){
 
                        break;
 
+               case 'u': /* unicast testing */
+                       unicast=1;
+                       break;
+
                case 'V': /* version */
-                       print_revision(progname,revision);
+                       print_revision(progname, NP_VERSION);
                        exit(STATE_OK);
 
                case 'h': /* help */
@@ -1064,7 +1176,7 @@ int call_getopt(int argc, char **argv){
                        break;
 
                case '?': /* help */
-                       usage2 (_("Unknown argument"), optarg);
+                       usage5 ();
                        break;
 
                default:
@@ -1081,111 +1193,116 @@ int validate_arguments(void){
        return OK;
         }
 
-#if defined(__sun__) || defined(__solaris__) || defined(__hpux__)
 
-                                               /* Kompf 2000-2003      see ACKNOWLEDGEMENTS */
+#if defined(__sun__) || defined(__solaris__) || defined(__hpux__)
+/* Kompf 2000-2003     see ACKNOWLEDGEMENTS */
 
 /* get a message from a stream; return type of message */
-static int get_msg(int fd)
-{
-    int flags = 0;
-    int res, ret;
-    ctl_area[0] = 0;
-    dat_area[0] = 0;
-    ret = 0;
-    res = getmsg(fd, &ctl, &dat, &flags);
-
-    if(res < 0) {
-        if(errno == EINTR) {
-            return(GOT_INTR);
-        } else {
-           printf("%s\n", "get_msg FAILED.");
-            return(GOT_ERR);
-        }
-    }
-    if(ctl.len > 0) {
-        ret |= GOT_CTRL;
-    }
-    if(dat.len > 0) {
-        ret |= GOT_DATA;
-    }
-    return(ret);
-}
+static int get_msg(int fd){
+       int flags = 0;
+       int res, ret;
+       ctl_area[0] = 0;
+       dat_area[0] = 0;
+       ret = 0;
+       res = getmsg(fd, &ctl, &dat, &flags);
+
+       if(res < 0){
+               if(errno == EINTR){
+                       return(GOT_INTR);
+                       }
+               else{
+                       printf("%s\n", "get_msg FAILED.");
+                       return(GOT_ERR);
+                       }
+               }
+       if(ctl.len > 0){
+               ret |= GOT_CTRL;
+               }
+       if(dat.len > 0){
+               ret |= GOT_DATA;
+               }
+
+       return(ret);
+       }
 
 /* verify that dl_primitive in ctl_area = prim */
-static int check_ctrl(int prim)
-{
-    dl_error_ack_t *err_ack = (dl_error_ack_t *)ctl_area;
-    if(err_ack->dl_primitive != prim) {
-       printf(_("Error: DLPI stream API failed to get MAC in check_ctrl: %s.\n"), strerror(errno));
-        exit(STATE_UNKNOWN);
-    }
-    return 0;
-}
+static int check_ctrl(int prim){
+       dl_error_ack_t *err_ack = (dl_error_ack_t *)ctl_area;
+
+       if(err_ack->dl_primitive != prim){
+               printf(_("Error: DLPI stream API failed to get MAC in check_ctrl: %s.\n"), strerror(errno));
+               exit(STATE_UNKNOWN);
+               }
+
+       return 0;
+       }
 
 /* put a control message on a stream */
-static int put_ctrl(int fd, int len, int pri)
-{
-    ctl.len = len;
-    if(putmsg(fd, &ctl, 0, pri) < 0) {
-       printf(_("Error: DLPI stream API failed to get MAC in put_ctrl/putmsg(): %s.\n"), strerror(errno));
-        exit(STATE_UNKNOWN);
-    }
-    return  0;
-}
+static int put_ctrl(int fd, int len, int pri){
+
+       ctl.len = len;
+       if(putmsg(fd, &ctl, 0, pri) < 0){
+               printf(_("Error: DLPI stream API failed to get MAC in put_ctrl/putmsg(): %s.\n"), strerror(errno));
+               exit(STATE_UNKNOWN);
+               }
+
+       return  0;
+       }
 
 /* put a control + data message on a stream */
-static int put_both(int fd, int clen, int dlen, int pri)
-{
-    ctl.len = clen;
-    dat.len = dlen;
-    if(putmsg(fd, &ctl, &dat, pri) < 0) {
-       printf(_("Error: DLPI stream API failed to get MAC in put_both/putmsg().\n"), strerror(errno));
-        exit(STATE_UNKNOWN);
-    }
-    return  0;
-}
+static int put_both(int fd, int clen, int dlen, int pri){
+
+       ctl.len = clen;
+       dat.len = dlen;
+       if(putmsg(fd, &ctl, &dat, pri) < 0){
+               printf(_("Error: DLPI stream API failed to get MAC in put_both/putmsg().\n"), strerror(errno));
+               exit(STATE_UNKNOWN);
+               }
+
+       return  0;
+       }
 
 /* open file descriptor and attach */
-static int dl_open(const char *dev, int unit, int *fd)
-{
-    dl_attach_req_t *attach_req = (dl_attach_req_t *)ctl_area;
-    if((*fd = open(dev, O_RDWR)) == -1) {
-       printf(_("Error: DLPI stream API failed to get MAC in dl_attach_req/open(%s..): %s.\n"), dev, strerror(errno));
-        exit(STATE_UNKNOWN);
-    }
-    attach_req->dl_primitive = DL_ATTACH_REQ;
-    attach_req->dl_ppa = unit;
-    put_ctrl(*fd, sizeof(dl_attach_req_t), 0);
-    get_msg(*fd);
-    return check_ctrl(DL_OK_ACK);
-}
+static int dl_open(const char *dev, int unit, int *fd){
+       dl_attach_req_t *attach_req = (dl_attach_req_t *)ctl_area;
+
+       if((*fd = open(dev, O_RDWR)) == -1){
+               printf(_("Error: DLPI stream API failed to get MAC in dl_attach_req/open(%s..): %s.\n"), dev, strerror(errno));
+               exit(STATE_UNKNOWN);
+               }
+       attach_req->dl_primitive = DL_ATTACH_REQ;
+       attach_req->dl_ppa = unit;
+       put_ctrl(*fd, sizeof(dl_attach_req_t), 0);
+       get_msg(*fd);
+       return check_ctrl(DL_OK_ACK);
+       }
 
 /* send DL_BIND_REQ */
-static int dl_bind(int fd, int sap, u_char *addr)
-{
-    dl_bind_req_t *bind_req = (dl_bind_req_t *)ctl_area;
-    dl_bind_ack_t *bind_ack = (dl_bind_ack_t *)ctl_area;
-    bind_req->dl_primitive = DL_BIND_REQ;
-    bind_req->dl_sap = sap;
-    bind_req->dl_max_conind = 1;
-    bind_req->dl_service_mode = DL_CLDLS;
-    bind_req->dl_conn_mgmt = 0;
-    bind_req->dl_xidtest_flg = 0;
-    put_ctrl(fd, sizeof(dl_bind_req_t), 0);
-    get_msg(fd);
-    if (GOT_ERR == check_ctrl(DL_BIND_ACK)) {
-       printf(_("Error: DLPI stream API failed to get MAC in dl_bind/check_ctrl(): %s.\n"), strerror(errno));
-        exit(STATE_UNKNOWN);
-    }
-    bcopy((u_char *)bind_ack + bind_ack->dl_addr_offset, addr,
-        bind_ack->dl_addr_length);
-    return 0;
-}
+static int dl_bind(int fd, int sap, u_char *addr){
+       dl_bind_req_t *bind_req = (dl_bind_req_t *)ctl_area;
+       dl_bind_ack_t *bind_ack = (dl_bind_ack_t *)ctl_area;
+
+       bind_req->dl_primitive = DL_BIND_REQ;
+       bind_req->dl_sap = sap;
+       bind_req->dl_max_conind = 1;
+       bind_req->dl_service_mode = DL_CLDLS;
+       bind_req->dl_conn_mgmt = 0;
+       bind_req->dl_xidtest_flg = 0;
+       put_ctrl(fd, sizeof(dl_bind_req_t), 0);
+       get_msg(fd);
+       if (GOT_ERR == check_ctrl(DL_BIND_ACK)){
+               printf(_("Error: DLPI stream API failed to get MAC in dl_bind/check_ctrl(): %s.\n"), strerror(errno));
+               exit(STATE_UNKNOWN);
+               }
+       bcopy((u_char *)bind_ack + bind_ack->dl_addr_offset, addr,
+             bind_ack->dl_addr_length);
+
+       return 0;
+       }
 
 /***********************************************************************
  * interface:
- * function mac_addr_dlpi - get the mac address of the interface with 
+ * function mac_addr_dlpi - get the mac address of the interface with
  *                          type dev (eg lnc, hme) and unit (0, 1 ..)
  *
  * parameter: addr: an array of six bytes, has to be allocated by the caller
@@ -1195,59 +1312,118 @@ static int dl_bind(int fd, int sap, u_char *addr)
  *
  ***********************************************************************/
 
-long mac_addr_dlpi( const char *dev, int unit, u_char  *addr) {
-
+long mac_addr_dlpi( const char *dev, int unit, u_char  *addr){
        int fd;
        u_char mac_addr[25];
 
-       if (GOT_ERR != dl_open(dev, unit, &fd)) {
-               if (GOT_ERR != dl_bind(fd, INSAP, mac_addr)) {
+       if(GOT_ERR != dl_open(dev, unit, &fd)){
+               if(GOT_ERR != dl_bind(fd, INSAP, mac_addr)){
                        bcopy( mac_addr, addr, 6);
                        return 0;
-                }
-       }
+                       }
+               }
         close(fd);
-       return -1;
-}
 
-                                               /* Kompf 2000-2003 */
+       return -1;
+       }
 
+/* Kompf 2000-2003 */
 #endif
 
 
+/* resolve host name or die (TODO: move this to netutils.c!) */
+void resolve_host(const char *in,struct in_addr *out){
+       struct addrinfo hints, *ai;
+
+       memset(&hints,0,sizeof(hints));
+       hints.ai_family=PF_INET;
+       if (getaddrinfo(in,NULL,&hints,&ai) != 0)
+               usage_va(_("Invalid hostname/address - %s"),optarg);
+
+       memcpy(out,&((struct sockaddr_in *)ai->ai_addr)->sin_addr,sizeof(*out));
+       freeaddrinfo(ai);
+       }
+
+
+/* parse MAC address string, return 6 bytes (unterminated) or NULL */
+unsigned char *mac_aton(const char *string){
+       static unsigned char result[6];
+       char tmp[3];
+       unsigned i, j;
+
+       for(i=0, j=0; string[i] != '\0' && j < sizeof(result); i++){
+               /* ignore ':' and any other non-hex character */
+               if(!isxdigit(string[i]) || !isxdigit(string[i+1]))
+                       continue;
+               tmp[0]=string[i];
+               tmp[1]=string[i+1];
+               tmp[2]='\0';
+               result[j]=strtol(tmp,(char **)NULL,16);
+               i++;
+               j++;
+               }
+
+       return (j==6) ? result : NULL;
+       }
+
+
+void print_hardware_address(const unsigned char *address){
+       int i;
+
+       printf(_("Hardware address: "));
+       for (i=0; i<5; i++)
+               printf("%2.2x:", address[i]);
+       printf("%2.2x", address[i]);
+       putchar('\n');
+       }
+
+
 /* print usage help */
 void print_help(void){
 
-       print_revision(progname,revision);
+       print_revision(progname, NP_VERSION);
 
        printf("Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)\n");
        printf (COPYRIGHT, copyright, email);
-       
-       printf(_("This plugin tests the availability of DHCP servers on a network.\n\n"));
+
+       printf("%s\n", _("This plugin tests the availability of DHCP servers on a network."));
+
+  printf ("\n\n");
 
        print_usage();
 
-       printf (_(UT_HELP_VRSN));
+       printf (UT_HELP_VRSN);
+       printf (UT_EXTRA_OPTS);
+
+       printf (UT_VERBOSE);
+
+       printf (" %s\n", "-s, --serverip=IPADDRESS");
+  printf ("    %s\n", _("IP address of DHCP server that we must hear from"));
+  printf (" %s\n", "-r, --requestedip=IPADDRESS");
+  printf ("    %s\n", _("IP address that should be offered by at least one DHCP server"));
+  printf (" %s\n", "-t, --timeout=INTEGER");
+  printf ("    %s\n", _("Seconds to wait for DHCPOFFER before timeout occurs"));
+  printf (" %s\n", "-i, --interface=STRING");
+  printf ("    %s\n", _("Interface to to use for listening (i.e. eth0)"));
+  printf (" %s\n", "-m, --mac=STRING");
+  printf ("    %s\n", _("MAC address to use in the DHCP request"));
+  printf (" %s\n", "-u, --unicast");
+  printf ("    %s\n", _("Unicast testing: mimic a DHCP relay, requires -s"));
+
+  printf (UT_SUPPORT);
+       return;
+       }
 
-       printf (_(UT_VERBOSE));
 
-       printf(_("\
- -s, --serverip=IPADDRESS\n\
-   IP address of DHCP server that we must hear from\n\
- -r, --requestedip=IPADDRESS\n\
-   IP address that should be offered by at least one DHCP server\n\
- -t, --timeout=INTEGER\n\
-   Seconds to wait for DHCPOFFER before timeout occurs\n\
- -i, --interface=STRING\n\
-   Interface to to use for listening (i.e. eth0)\n"));
-}
+void
+print_usage(void){
 
+  printf (_("Usage:"));
+  printf (" %s [-v] [-u] [-s serverip] [-r requestedip] [-t timeout]\n",progname);
+  printf ("                  [-i interface] [-m mac]\n");
 
-void print_usage(void)
-{
-       printf("\
-Usage: %s [-s serverip] [-r requestedip] [-t timeout] [-i interface] [-v]\n",progname);
-}
+       return;
+       }