plugins-root/check_dhcp.c

   1 /******************************************************************************
   2 *
   3 * Nagios check_dhcp plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)
   7 * Copyright (c) 2001-2006 Nagios Plugin Development Team
   8 *
   9 * Last Modified: $Date$
  10 *
  11 * Description:
  12 *
  13 * This file contains the check_dhcp plugin
  14 *
  15 *  This plugin tests the availability of DHCP servers on a network.
  16 *
  17 *
  18 * License Information:
  19 *
  20 * This program is free software; you can redistribute it and/or modify
  21 * it under the terms of the GNU General Public License as published by
  22 * the Free Software Foundation; either version 2 of the License, or
  23 * (at your option) any later version.
  24 *
  25 * This program is distributed in the hope that it will be useful,
  26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28 * GNU General Public License for more details.
  29 *
  30 * You should have received a copy of the GNU General Public License
  31 * along with this program; if not, write to the Free Software
  32 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  33 *
  34 * $Id$
  35 *
  36 *****************************************************************************/
  37
  38 const char *progname = "check_dhcp";
  39 const char *revision = "$Revision$";
  40 const char *copyright = "2001-2006";
  41 const char *email = "nagiosplug-devel@lists.sourceforge.net";
  42
  43 #include "common.h"
  44 #include "netutils.h"
  45 #include "utils.h"
  46
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <errno.h>
  51 #include <unistd.h>
  52 #include <sys/time.h>
  53 #include <sys/ioctl.h>
  54 #include <fcntl.h>
  55 #include <getopt.h>
  56 #include <sys/socket.h>
  57 #include <sys/types.h>
  58 #include <netdb.h>
  59 #include <netinet/in.h>
  60 #include <net/if.h>
  61 #include <arpa/inet.h>
  62
  63 #if defined( __linux__ )
  64
  65 #include <linux/if_ether.h>
  66 #include <features.h>
  67
  68 #elif defined (__bsd__)
  69
  70 #include <netinet/if_ether.h>
  71 #include <sys/param.h>
  72 #include <sys/sysctl.h>
  73 #include <net/if_dl.h>
  74
  75 #elif defined(__sun__) || defined(__solaris__) || defined(__hpux__)
  76
  77 #define INSAP 22
  78 #define OUTSAP 24
  79
  80 #include <signal.h>
  81 #include <ctype.h>
  82 #include <sys/stropts.h>
  83 #include <sys/poll.h>
  84 #include <sys/dlpi.h>
  85
  86 #define bcopy(source, destination, length) memcpy(destination, source, length)
  87
  88 #define AREA_SZ 5000            /* buffer length in bytes */
  89 static u_long ctl_area[AREA_SZ];
  90 static u_long dat_area[AREA_SZ];
  91 static struct strbuf ctl = {AREA_SZ, 0, (char *)ctl_area};
  92 static struct strbuf dat = {AREA_SZ, 0, (char *)dat_area};
  93
  94 #define GOT_CTRL 1
  95 #define GOT_DATA 2
  96 #define GOT_BOTH 3
  97 #define GOT_INTR 4
  98 #define GOT_ERR 128
  99
 100 #define u_int8_t         uint8_t
 101 #define u_int16_t       uint16_t
 102 #define u_int32_t       uint32_t
 103
 104 static int get_msg(int);
 105 static int check_ctrl(int);
 106 static int put_ctrl(int, int, int);
 107 static int put_both(int, int, int, int);
 108 static int dl_open(const char *, int, int *);
 109 static int dl_bind(int, int, u_char *);
 110 long mac_addr_dlpi( const char *, int, u_char *);
 111
 112 #endif
 113
 114
 115
 116 /**** Common definitions ****/
 117
 118 #define OK                0
 119 #define ERROR             -1
 120
 121 #define FALSE             0
 122 #define TRUE              1
 123
 124
 125 /**** DHCP definitions ****/
 126
 127 #define MAX_DHCP_CHADDR_LENGTH           16
 128 #define MAX_DHCP_SNAME_LENGTH            64
 129 #define MAX_DHCP_FILE_LENGTH             128
 130 #define MAX_DHCP_OPTIONS_LENGTH          312
 131
 132
 133 typedef struct dhcp_packet_struct{
 134         u_int8_t  op;                   /* packet type */
 135         u_int8_t  htype;                /* type of hardware address for this machine (Ethernet, etc) */
 136         u_int8_t  hlen;                 /* length of hardware address (of this machine) */
 137         u_int8_t  hops;                 /* hops */
 138         u_int32_t xid;                  /* random transaction id number - chosen by this machine */
 139         u_int16_t secs;                 /* seconds used in timing */
 140         u_int16_t flags;                /* flags */
 141         struct in_addr ciaddr;          /* IP address of this machine (if we already have one) */
 142         struct in_addr yiaddr;          /* IP address of this machine (offered by the DHCP server) */
 143         struct in_addr siaddr;          /* IP address of DHCP server */
 144         struct in_addr giaddr;          /* IP address of DHCP relay */
 145         unsigned char chaddr [MAX_DHCP_CHADDR_LENGTH];      /* hardware address of this machine */
 146         char sname [MAX_DHCP_SNAME_LENGTH];    /* name of DHCP server */
 147         char file [MAX_DHCP_FILE_LENGTH];      /* boot file name (used for diskless booting?) */
 148         char options[MAX_DHCP_OPTIONS_LENGTH];  /* options */
 149         }dhcp_packet;
 150
 151
 152 typedef struct dhcp_offer_struct{
 153         struct in_addr server_address;   /* address of DHCP server that sent this offer */
 154         struct in_addr offered_address;  /* the IP address that was offered to us */
 155         u_int32_t lease_time;            /* lease time in seconds */
 156         u_int32_t renewal_time;          /* renewal time in seconds */
 157         u_int32_t rebinding_time;        /* rebinding time in seconds */
 158         struct dhcp_offer_struct *next;
 159         }dhcp_offer;
 160
 161
 162 typedef struct requested_server_struct{
 163         struct in_addr server_address;
 164         int answered;
 165         struct requested_server_struct *next;
 166         }requested_server;
 167
 168
 169 #define BOOTREQUEST     1
 170 #define BOOTREPLY       2
 171
 172 #define DHCPDISCOVER    1
 173 #define DHCPOFFER       2
 174 #define DHCPREQUEST     3
 175 #define DHCPDECLINE     4
 176 #define DHCPACK         5
 177 #define DHCPNACK        6
 178 #define DHCPRELEASE     7
 179
 180 #define DHCP_OPTION_MESSAGE_TYPE        53
 181 #define DHCP_OPTION_HOST_NAME           12
 182 #define DHCP_OPTION_BROADCAST_ADDRESS   28
 183 #define DHCP_OPTION_REQUESTED_ADDRESS   50
 184 #define DHCP_OPTION_LEASE_TIME          51
 185 #define DHCP_OPTION_SERVER_IDENTIFIER   54
 186 #define DHCP_OPTION_RENEWAL_TIME        58
 187 #define DHCP_OPTION_REBINDING_TIME      59
 188 #define DHCP_OPTION_END                 255
 189
 190 #define DHCP_INFINITE_TIME              0xFFFFFFFF
 191
 192 #define DHCP_BROADCAST_FLAG 32768
 193
 194 #define DHCP_SERVER_PORT   67
 195 #define DHCP_CLIENT_PORT   68
 196
 197 #define ETHERNET_HARDWARE_ADDRESS            1     /* used in htype field of dhcp packet */
 198 #define ETHERNET_HARDWARE_ADDRESS_LENGTH     6     /* length of Ethernet hardware addresses */
 199
 200 unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH]="";
 201
 202 char network_interface_name[IFNAMSIZ]="eth0";
 203
 204 u_int32_t packet_xid=0;
 205
 206 u_int32_t dhcp_lease_time=0;
 207 u_int32_t dhcp_renewal_time=0;
 208 u_int32_t dhcp_rebinding_time=0;
 209
 210 int dhcpoffer_timeout=2;
 211
 212 dhcp_offer *dhcp_offer_list=NULL;
 213 requested_server *requested_server_list=NULL;
 214
 215 int valid_responses=0;     /* number of valid DHCPOFFERs we received */
 216 int requested_servers=0;
 217 int requested_responses=0;
 218
 219 int request_specific_address=FALSE;
 220 int received_requested_address=FALSE;
 221 int verbose=0;
 222 struct in_addr requested_address;
 223
 224
 225 int process_arguments(int, char **);
 226 int call_getopt(int, char **);
 227 int validate_arguments(void);
 228 void print_usage(void);
 229 void print_help(void);
 230
 231 int get_hardware_address(int,char *);
 232
 233 int send_dhcp_discover(int);
 234 int get_dhcp_offer(int);
 235
 236 int get_results(void);
 237
 238 int add_dhcp_offer(struct in_addr,dhcp_packet *);
 239 int free_dhcp_offer_list(void);
 240 int free_requested_server_list(void);
 241
 242 int create_dhcp_socket(void);
 243 int close_dhcp_socket(int);
 244 int send_dhcp_packet(void *,int,int,struct sockaddr_in *);
 245 int receive_dhcp_packet(void *,int,int,int,struct sockaddr_in *);
 246
 247
 248
 249 int main(int argc, char **argv){
 250         int dhcp_socket;
 251         int result = STATE_UNKNOWN;
 252
 253         setlocale (LC_ALL, "");
 254         bindtextdomain (PACKAGE, LOCALEDIR);
 255         textdomain (PACKAGE);
 256
 257         if(process_arguments(argc,argv)!=OK){
 258                 usage4 (_("Could not parse arguments"));
 259                 }
 260
 261         /* create socket for DHCP communications */
 262         dhcp_socket=create_dhcp_socket();
 263
 264         /* get hardware address of client machine */
 265         get_hardware_address(dhcp_socket,network_interface_name);
 266
 267         /* send DHCPDISCOVER packet */
 268         send_dhcp_discover(dhcp_socket);
 269
 270         /* wait for a DHCPOFFER packet */
 271         get_dhcp_offer(dhcp_socket);
 272
 273         /* close socket we created */
 274         close_dhcp_socket(dhcp_socket);
 275
 276         /* determine state/plugin output to return */
 277         result=get_results();
 278
 279         /* free allocated memory */
 280         free_dhcp_offer_list();
 281         free_requested_server_list();
 282
 283         return result;
 284         }
 285
 286
 287
 288 /* determines hardware address on client machine */
 289 int get_hardware_address(int sock,char *interface_name){
 290
 291         int i;
 292
 293 #if defined(__linux__)
 294         struct ifreq ifr;
 295
 296         strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name));
 297
 298         /* try and grab hardware address of requested interface */
 299         if(ioctl(sock,SIOCGIFHWADDR,&ifr)<0){
 300                 printf(_("Error: Could not get hardware address of interface '%s'\n"),interface_name);
 301                 exit(STATE_UNKNOWN);
 302                 }
 303
 304         memcpy(&client_hardware_address[0],&ifr.ifr_hwaddr.sa_data,6);
 305
 306 #elif defined(__bsd__)
 307                                                 /* King 2004    see ACKNOWLEDGEMENTS */
 308
 309         int                     mib[6], len;
 310         char                    *buf;
 311         unsigned char           *ptr;
 312         struct if_msghdr        *ifm;
 313         struct sockaddr_dl      *sdl;
 314
 315         mib[0] = CTL_NET;
 316         mib[1] = AF_ROUTE;
 317         mib[2] = 0;
 318         mib[3] = AF_LINK;
 319         mib[4] = NET_RT_IFLIST;
 320
 321         if((mib[5] = if_nametoindex(interface_name)) == 0){
 322                 printf(_("Error: if_nametoindex error - %s.\n"), strerror(errno));
 323                 exit(STATE_UNKNOWN);
 324                 }
 325
 326         if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0){
 327                 printf(_("Error: Couldn't get hardware address from %s. sysctl 1 error - %s.\n"), interface_name, strerror(errno));
 328                 exit(STATE_UNKNOWN);
 329                 }
 330
 331         if((buf = malloc(len)) == NULL){
 332                 printf(_("Error: Couldn't get hardware address from interface %s. malloc error - %s.\n"), interface_name, strerror(errno));
 333                 exit(4);
 334                 }
 335
 336         if(sysctl(mib, 6, buf, &len, NULL, 0) < 0){
 337                 printf(_("Error: Couldn't get hardware address from %s. sysctl 2 error - %s.\n"), interface_name, strerror(errno));
 338                 exit(STATE_UNKNOWN);
 339                 }
 340
 341         ifm = (struct if_msghdr *)buf;
 342         sdl = (struct sockaddr_dl *)(ifm + 1);
 343         ptr = (unsigned char *)LLADDR(sdl);
 344         memcpy(&client_hardware_address[0], ptr, 6) ;
 345                                                 /* King 2004 */
 346
 347 #elif defined(__sun__) || defined(__solaris__)
 348
 349                                                 /* Kompf 2000-2003      see ACKNOWLEDGEMENTS */
 350         long stat;
 351         char dev[20] = "/dev/";
 352         char *p;
 353         int unit;
 354
 355         for(p = interface_name; *p && isalpha(*p); p++)
 356                 /* no-op */ ;
 357         if( p != '\0' ){
 358                 unit = atoi(p) ;
 359                 *p = '\0' ;
 360                 strncat(dev, interface_name, 6) ;
 361                 }
 362         else{
 363                 printf(_("Error: can't find unit number in interface_name (%s) - expecting TypeNumber eg lnc0.\n"), interface_name);
 364                 exit(STATE_UNKNOWN);
 365                 }
 366         stat = mac_addr_dlpi(dev, unit, client_hardware_address);
 367         if(stat != 0){
 368                 printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit);
 369                 exit(STATE_UNKNOWN);
 370                 }
 371
 372 #elif defined(__hpux__)
 373
 374         long stat;
 375         char dev[20] = "/dev/dlpi" ;
 376         int unit = 0;
 377
 378         stat = mac_addr_dlpi(dev, unit, client_hardware_address);
 379         if(stat != 0){
 380                 printf(_("Error: can't read MAC address from DLPI streams interface for device %s unit %d.\n"), dev, unit);
 381                 exit(STATE_UNKNOWN);
 382                 }
 383                                                 /* Kompf 2000-2003 */
 384
 385 #else
 386         printf(_("Error: can't get MAC address for this architecture.\n"));
 387         exit(STATE_UNKNOWN);
 388 #endif
 389
 390         if(verbose){
 391                 printf(_("Hardware address: "));
 392                 for (i=0; i<6; ++i)
 393                         printf("%2.2x", client_hardware_address[i]);
 394                 printf( "\n");
 395                 }
 396
 397         return OK;
 398         }
 399
 400
 401 /* sends a DHCPDISCOVER broadcast message in an attempt to find DHCP servers */
 402 int send_dhcp_discover(int sock){
 403         dhcp_packet discover_packet;
 404         struct sockaddr_in sockaddr_broadcast;
 405     unsigned short opts;
 406
 407
 408         /* clear the packet data structure */
 409         bzero(&discover_packet,sizeof(discover_packet));
 410
 411
 412         /* boot request flag (backward compatible with BOOTP servers) */
 413         discover_packet.op=BOOTREQUEST;
 414
 415         /* hardware address type */
 416         discover_packet.htype=ETHERNET_HARDWARE_ADDRESS;
 417
 418         /* length of our hardware address */
 419         discover_packet.hlen=ETHERNET_HARDWARE_ADDRESS_LENGTH;
 420
 421         discover_packet.hops=0;
 422
 423         /* transaction id is supposed to be random */
 424         srand(time(NULL));
 425         packet_xid=random();
 426         discover_packet.xid=htonl(packet_xid);
 427
 428         /**** WHAT THE HECK IS UP WITH THIS?!?  IF I DON'T MAKE THIS CALL, ONLY ONE SERVER RESPONSE IS PROCESSED!!!! ****/
 429         /* downright bizzarre... */
 430         ntohl(discover_packet.xid);
 431
 432         /*discover_packet.secs=htons(65535);*/
 433         discover_packet.secs=0xFF;
 434
 435         /* tell server it should broadcast its response */
 436         discover_packet.flags=htons(DHCP_BROADCAST_FLAG);
 437
 438         /* our hardware address */
 439         memcpy(discover_packet.chaddr,client_hardware_address,ETHERNET_HARDWARE_ADDRESS_LENGTH);
 440
 441         /* first four bytes of options field is magic cookie (as per RFC 2132) */
 442         discover_packet.options[0]='\x63';
 443         discover_packet.options[1]='\x82';
 444         discover_packet.options[2]='\x53';
 445         discover_packet.options[3]='\x63';
 446
 447     opts = 4;
 448         /* DHCP message type is embedded in options field */
 449         discover_packet.options[opts++]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
 450         discover_packet.options[opts++]='\x01';               /* DHCP message option length in bytes */
 451         discover_packet.options[opts++]=DHCPDISCOVER;
 452
 453         /* the IP address we're requesting */
 454         if(request_specific_address==TRUE){
 455                 discover_packet.options[opts++]=DHCP_OPTION_REQUESTED_ADDRESS;
 456                 discover_packet.options[opts++]='\x04';
 457                 memcpy(&discover_packet.options[opts],&requested_address,sizeof(requested_address));
 458                 opts += sizeof(requested_address);
 459                 }
 460         discover_packet.options[opts++]=DHCP_OPTION_END;
 461
 462         /* send the DHCPDISCOVER packet to broadcast address */
 463         sockaddr_broadcast.sin_family=AF_INET;
 464         sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
 465         sockaddr_broadcast.sin_addr.s_addr=INADDR_BROADCAST;
 466         bzero(&sockaddr_broadcast.sin_zero,sizeof(sockaddr_broadcast.sin_zero));
 467
 468
 469         if(verbose){
 470                 printf(_("DHCPDISCOVER to %s port %d\n"),inet_ntoa(sockaddr_broadcast.sin_addr),ntohs(sockaddr_broadcast.sin_port));
 471                 printf("DHCPDISCOVER XID: %lu (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
 472                 printf("DHCDISCOVER ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
 473                 printf("DHCDISCOVER yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
 474                 printf("DHCDISCOVER siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
 475                 printf("DHCDISCOVER giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
 476                 }
 477
 478         /* send the DHCPDISCOVER packet out */
 479         send_dhcp_packet(&discover_packet,sizeof(discover_packet),sock,&sockaddr_broadcast);
 480
 481         if(verbose)
 482                 printf("\n\n");
 483
 484         return OK;
 485         }
 486
 487
 488
 489
 490 /* waits for a DHCPOFFER message from one or more DHCP servers */
 491 int get_dhcp_offer(int sock){
 492         dhcp_packet offer_packet;
 493         struct sockaddr_in source;
 494         struct sockaddr_in via;
 495         int result=OK;
 496         int responses=0;
 497         int x;
 498         time_t start_time;
 499         time_t current_time;
 500
 501         time(&start_time);
 502
 503         /* receive as many responses as we can */
 504         for(responses=0,valid_responses=0;;){
 505
 506                 time(&current_time);
 507                 if((current_time-start_time)>=dhcpoffer_timeout)
 508                         break;
 509
 510                 if(verbose)
 511                         printf("\n\n");
 512
 513                 bzero(&source,sizeof(source));
 514                 bzero(&via,sizeof(via));
 515                 bzero(&offer_packet,sizeof(offer_packet));
 516
 517                 result=OK;
 518                 result=receive_dhcp_packet(&offer_packet,sizeof(offer_packet),sock,dhcpoffer_timeout,&source);
 519
 520                 if(result!=OK){
 521                         if(verbose)
 522                                 printf(_("Result=ERROR\n"));
 523
 524                         continue;
 525                         }
 526                 else{
 527                         if(verbose)
 528                                 printf(_("Result=OK\n"));
 529
 530                         responses++;
 531                         }
 532
 533                 /* The "source" is either a server or a relay. */
 534                 /* Save a copy of "source" into "via" even if it's via itself */
 535                 memcpy(&via,&source,sizeof(source)) ;
 536
 537                 /* If siaddr is non-zero, set "source" to siaddr */
 538                 if(offer_packet.siaddr.s_addr != 0L){
 539                         source.sin_addr.s_addr = offer_packet.siaddr.s_addr ;
 540                         }
 541
 542                 if(verbose){
 543                         printf(_("DHCPOFFER from IP address %s"),inet_ntoa(source.sin_addr));
 544                         printf(_(" via %s\n"),inet_ntoa(via.sin_addr));
 545                         printf("DHCPOFFER XID: %lu (0x%X)\n",ntohl(offer_packet.xid),ntohl(offer_packet.xid));
 546                         }
 547
 548                 /* check packet xid to see if its the same as the one we used in the discover packet */
 549                 if(ntohl(offer_packet.xid)!=packet_xid){
 550                         if(verbose)
 551                                 printf(_("DHCPOFFER XID (%lu) did not match DHCPDISCOVER XID (%lu) - ignoring packet\n"),ntohl(offer_packet.xid),packet_xid);
 552
 553                         continue;
 554                         }
 555
 556                 /* check hardware address */
 557                 result=OK;
 558                 if(verbose)
 559                         printf("DHCPOFFER chaddr: ");
 560
 561                 for(x=0;x<ETHERNET_HARDWARE_ADDRESS_LENGTH;x++){
 562                         if(verbose)
 563                                 printf("%02X",(unsigned char)offer_packet.chaddr[x]);
 564
 565                         if(offer_packet.chaddr[x]!=client_hardware_address[x])
 566                                 result=ERROR;
 567                         }
 568                 if(verbose)
 569                         printf("\n");
 570
 571                 if(result==ERROR){
 572                         if(verbose)
 573                                 printf(_("DHCPOFFER hardware address did not match our own - ignoring packet\n"));
 574
 575                         continue;
 576                         }
 577
 578                 if(verbose){
 579                         printf("DHCPOFFER ciaddr: %s\n",inet_ntoa(offer_packet.ciaddr));
 580                         printf("DHCPOFFER yiaddr: %s\n",inet_ntoa(offer_packet.yiaddr));
 581                         printf("DHCPOFFER siaddr: %s\n",inet_ntoa(offer_packet.siaddr));
 582                         printf("DHCPOFFER giaddr: %s\n",inet_ntoa(offer_packet.giaddr));
 583                         }
 584
 585                 add_dhcp_offer(source.sin_addr,&offer_packet);
 586
 587                 valid_responses++;
 588                 }
 589
 590         if(verbose){
 591                 printf(_("Total responses seen on the wire: %d\n"),responses);
 592                 printf(_("Valid responses for this machine: %d\n"),valid_responses);
 593                 }
 594
 595         return OK;
 596         }
 597
 598
 599
 600 /* sends a DHCP packet */
 601 int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in *dest){
 602         int result;
 603
 604         result=sendto(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)dest,sizeof(*dest));
 605
 606         if(verbose)
 607                 printf(_("send_dhcp_packet result: %d\n"),result);
 608
 609         if(result<0)
 610                 return ERROR;
 611
 612         return OK;
 613         }
 614
 615
 616
 617 /* receives a DHCP packet */
 618 int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, struct sockaddr_in *address){
 619         struct timeval tv;
 620         fd_set readfds;
 621         int recv_result;
 622         socklen_t address_size;
 623         struct sockaddr_in source_address;
 624
 625
 626         /* wait for data to arrive (up time timeout) */
 627         tv.tv_sec=timeout;
 628         tv.tv_usec=0;
 629         FD_ZERO(&readfds);
 630         FD_SET(sock,&readfds);
 631         select(sock+1,&readfds,NULL,NULL,&tv);
 632
 633         /* make sure some data has arrived */
 634         if(!FD_ISSET(sock,&readfds)){
 635                 if(verbose)
 636                         printf(_("No (more) data received\n"));
 637                 return ERROR;
 638                 }
 639
 640         else{
 641
 642                 /* why do we need to peek first?  i don't know, its a hack.  without it, the source address of the first packet received was
 643                    not being interpreted correctly.  sigh... */
 644                 bzero(&source_address,sizeof(source_address));
 645                 address_size=sizeof(source_address);
 646                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,MSG_PEEK,(struct sockaddr *)&source_address,&address_size);
 647                 if(verbose)
 648                         printf("recv_result_1: %d\n",recv_result);
 649                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)&source_address,&address_size);
 650                 if(verbose)
 651                         printf("recv_result_2: %d\n",recv_result);
 652
 653                 if(recv_result==-1){
 654                         if(verbose){
 655                                 printf(_("recvfrom() failed, "));
 656                                 printf("errno: (%d) -> %s\n",errno,strerror(errno));
 657                                 }
 658                         return ERROR;
 659                         }
 660                 else{
 661                         if(verbose){
 662                                 printf(_("receive_dhcp_packet() result: %d\n"),recv_result);
 663                                 printf(_("receive_dhcp_packet() source: %s\n"),inet_ntoa(source_address.sin_addr));
 664                                 }
 665
 666                         memcpy(address,&source_address,sizeof(source_address));
 667                         return OK;
 668                         }
 669                 }
 670
 671         return OK;
 672         }
 673
 674
 675 /* creates a socket for DHCP communication */
 676 int create_dhcp_socket(void){
 677         struct sockaddr_in myname;
 678         struct ifreq interface;
 679         int sock;
 680         int flag=1;
 681
 682         /* Set up the address we're going to bind to. */
 683         bzero(&myname,sizeof(myname));
 684         myname.sin_family=AF_INET;
 685         myname.sin_port=htons(DHCP_CLIENT_PORT);
 686         myname.sin_addr.s_addr=INADDR_ANY;                 /* listen on any address */
 687         bzero(&myname.sin_zero,sizeof(myname.sin_zero));
 688
 689         /* create a socket for DHCP communications */
 690         sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
 691         if(sock<0){
 692                 printf(_("Error: Could not create socket!\n"));
 693                 exit(STATE_UNKNOWN);
 694                 }
 695
 696         if(verbose)
 697                 printf("DHCP socket: %d\n",sock);
 698
 699         /* set the reuse address flag so we don't get errors when restarting */
 700         flag=1;
 701         if(setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&flag,sizeof(flag))<0){
 702                 printf(_("Error: Could not set reuse address option on DHCP socket!\n"));
 703                 exit(STATE_UNKNOWN);
 704                 }
 705
 706         /* set the broadcast option - we need this to listen to DHCP broadcast messages */
 707         if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
 708                 printf(_("Error: Could not set broadcast option on DHCP socket!\n"));
 709                 exit(STATE_UNKNOWN);
 710                 }
 711
 712         /* bind socket to interface */
 713 #if defined(__linux__)
 714         strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ);
 715         if(setsockopt(sock,SOL_SOCKET,SO_BINDTODEVICE,(char *)&interface,sizeof(interface))<0){
 716                 printf(_("Error: Could not bind socket to interface %s.  Check your privileges...\n"),network_interface_name);
 717                 exit(STATE_UNKNOWN);
 718                 }
 719
 720 #else
 721         strncpy(interface.ifr_name,network_interface_name,IFNAMSIZ);
 722 #endif
 723
 724         /* bind the socket */
 725         if(bind(sock,(struct sockaddr *)&myname,sizeof(myname))<0){
 726                 printf(_("Error: Could not bind to DHCP socket (port %d)!  Check your privileges...\n"),DHCP_CLIENT_PORT);
 727                 exit(STATE_UNKNOWN);
 728                 }
 729
 730         return sock;
 731         }
 732
 733
 734 /* closes DHCP socket */
 735 int close_dhcp_socket(int sock){
 736
 737         close(sock);
 738
 739         return OK;
 740         }
 741
 742
 743 /* adds a requested server address to list in memory */
 744 int add_requested_server(struct in_addr server_address){
 745         requested_server *new_server;
 746
 747         new_server=(requested_server *)malloc(sizeof(requested_server));
 748         if(new_server==NULL)
 749                 return ERROR;
 750
 751         new_server->server_address=server_address;
 752         new_server->answered=FALSE;
 753
 754         new_server->next=requested_server_list;
 755         requested_server_list=new_server;
 756
 757         requested_servers++;
 758
 759         if(verbose)
 760                 printf(_("Requested server address: %s\n"),inet_ntoa(new_server->server_address));
 761
 762         return OK;
 763         }
 764
 765
 766
 767
 768 /* adds a DHCP OFFER to list in memory */
 769 int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
 770         dhcp_offer *new_offer;
 771         int x;
 772         unsigned option_type;
 773         unsigned option_length;
 774         struct in_addr serv_ident = {0};
 775
 776         if(offer_packet==NULL)
 777                 return ERROR;
 778
 779         /* process all DHCP options present in the packet */
 780         for(x=4;x<MAX_DHCP_OPTIONS_LENGTH;){
 781
 782                 /* end of options (0 is really just a pad, but bail out anyway) */
 783                 if((int)offer_packet->options[x]==-1 || (int)offer_packet->options[x]==0)
 784                         break;
 785
 786                 /* get option type */
 787                 option_type=offer_packet->options[x++];
 788
 789                 /* get option length */
 790                 option_length=offer_packet->options[x++];
 791
 792                 if(verbose)
 793                         printf("Option: %d (0x%02X)\n",option_type,option_length);
 794
 795                 /* get option data */
 796                 switch(option_type){
 797                 case DHCP_OPTION_LEASE_TIME:
 798                         memcpy(&dhcp_lease_time, &offer_packet->options[x],sizeof(dhcp_lease_time));
 799                         dhcp_lease_time = ntohl(dhcp_lease_time);
 800                         break;
 801                 case DHCP_OPTION_RENEWAL_TIME:
 802                         memcpy(&dhcp_renewal_time, &offer_packet->options[x],sizeof(dhcp_renewal_time));
 803                         dhcp_renewal_time = ntohl(dhcp_renewal_time);
 804                         break;
 805                 case DHCP_OPTION_REBINDING_TIME:
 806                         memcpy(&dhcp_rebinding_time, &offer_packet->options[x],sizeof(dhcp_rebinding_time));
 807                         dhcp_rebinding_time = ntohl(dhcp_rebinding_time);
 808                         break;
 809                 case DHCP_OPTION_SERVER_IDENTIFIER:
 810                         memcpy(&serv_ident.s_addr, &offer_packet->options[x],sizeof(serv_ident.s_addr));
 811                         break;
 812                         }
 813
 814                 /* skip option data we're ignoring */
 815                 if(option_type!=DHCP_OPTION_REBINDING_TIME)
 816                         x+=option_length;
 817                 }
 818
 819         if(verbose){
 820                 if(dhcp_lease_time==DHCP_INFINITE_TIME)
 821                         printf(_("Lease Time: Infinite\n"));
 822                 else
 823                         printf(_("Lease Time: %lu seconds\n"),(unsigned long)dhcp_lease_time);
 824                 if(dhcp_renewal_time==DHCP_INFINITE_TIME)
 825                         printf(_("Renewal Time: Infinite\n"));
 826                 else
 827                         printf(_("Renewal Time: %lu seconds\n"),(unsigned long)dhcp_renewal_time);
 828                 if(dhcp_rebinding_time==DHCP_INFINITE_TIME)
 829                         printf(_("Rebinding Time: Infinite\n"));
 830                 printf(_("Rebinding Time: %lu seconds\n"),(unsigned long)dhcp_rebinding_time);
 831                 }
 832
 833         new_offer=(dhcp_offer *)malloc(sizeof(dhcp_offer));
 834
 835         if(new_offer==NULL)
 836                 return ERROR;
 837
 838         /*
 839          * RFC 2131 (2.) says: "DHCP clarifies the interpretation of the
 840          * 'siaddr' field as the address of the server to use in the next step
 841          * of the client's bootstrap process.  A DHCP server may return its own
 842          * address in the 'siaddr' field, if the server is prepared to supply
 843          * the next bootstrap service (e.g., delivery of an operating system
 844          * executable image).  A DHCP server always returns its own address in
 845          * the 'server identifier' option."  'serv_ident' is the 'server
 846          * identifier' option, 'source' is the 'siaddr' field or (if 'siaddr'
 847          * wasn't available) the IP address we received the DHCPOFFER from.  If
 848          * 'serv_ident' isn't available for some reason, we use 'source'.
 849          */
 850         new_offer->server_address=serv_ident.s_addr?serv_ident:source;
 851         new_offer->offered_address=offer_packet->yiaddr;
 852         new_offer->lease_time=dhcp_lease_time;
 853         new_offer->renewal_time=dhcp_renewal_time;
 854         new_offer->rebinding_time=dhcp_rebinding_time;
 855
 856
 857         if(verbose){
 858                 printf(_("Added offer from server @ %s"),inet_ntoa(new_offer->server_address));
 859                 printf(_(" of IP address %s\n"),inet_ntoa(new_offer->offered_address));
 860                 }
 861
 862         /* add new offer to head of list */
 863         new_offer->next=dhcp_offer_list;
 864         dhcp_offer_list=new_offer;
 865
 866         return OK;
 867         }
 868
 869
 870 /* frees memory allocated to DHCP OFFER list */
 871 int free_dhcp_offer_list(void){
 872         dhcp_offer *this_offer;
 873         dhcp_offer *next_offer;
 874
 875         for(this_offer=dhcp_offer_list;this_offer!=NULL;this_offer=next_offer){
 876                 next_offer=this_offer->next;
 877                 free(this_offer);
 878                 }
 879
 880         return OK;
 881         }
 882
 883
 884 /* frees memory allocated to requested server list */
 885 int free_requested_server_list(void){
 886         requested_server *this_server;
 887         requested_server *next_server;
 888
 889         for(this_server=requested_server_list;this_server!=NULL;this_server=next_server){
 890                 next_server=this_server->next;
 891                 free(this_server);
 892                 }
 893
 894         return OK;
 895         }
 896
 897
 898 /* gets state and plugin output to return */
 899 int get_results(void){
 900         dhcp_offer *temp_offer;
 901         requested_server *temp_server;
 902         int result;
 903         u_int32_t max_lease_time=0;
 904
 905         received_requested_address=FALSE;
 906
 907         /* checks responses from requested servers */
 908         requested_responses=0;
 909         if(requested_servers>0){
 910
 911                 for(temp_server=requested_server_list;temp_server!=NULL;temp_server=temp_server->next){
 912
 913                         for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
 914
 915                                 /* get max lease time we were offered */
 916                                 if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
 917                                         max_lease_time=temp_offer->lease_time;
 918
 919                                 /* see if we got the address we requested */
 920                                 if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
 921                                         received_requested_address=TRUE;
 922
 923                                 /* see if the servers we wanted a response from talked to us or not */
 924                                 if(!memcmp(&temp_offer->server_address,&temp_server->server_address,sizeof(temp_server->server_address))){
 925                                         if(verbose){
 926                                                 printf(_("DHCP Server Match: Offerer=%s"),inet_ntoa(temp_offer->server_address));
 927                                                 printf(_(" Requested=%s"),inet_ntoa(temp_server->server_address));
 928                                                 if(temp_server->answered)
 929                                                         printf(_(" (duplicate)"));
 930                                                 printf(_("\n"));
 931                                                 }
 932                                         if(temp_server->answered == FALSE){
 933                                                 requested_responses++;
 934                                                 temp_server->answered=TRUE;
 935                                                 }
 936                                         }
 937                                 }
 938                         }
 939
 940                 }
 941
 942         /* else check and see if we got our requested address from any server */
 943         else{
 944
 945                 for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
 946
 947                         /* get max lease time we were offered */
 948                         if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
 949                                 max_lease_time=temp_offer->lease_time;
 950
 951                         /* see if we got the address we requested */
 952                         if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
 953                                 received_requested_address=TRUE;
 954                         }
 955                 }
 956
 957         result=STATE_OK;
 958         if(valid_responses==0)
 959                 result=STATE_CRITICAL;
 960         else if(requested_servers>0 && requested_responses==0)
 961                 result=STATE_CRITICAL;
 962         else if(requested_responses<requested_servers)
 963                 result=STATE_WARNING;
 964         else if(request_specific_address==TRUE && received_requested_address==FALSE)
 965                 result=STATE_WARNING;
 966
 967         if(result==0)               /* garrett honeycutt 2005 */
 968                 printf("OK: ");
 969         else if(result==1)
 970                 printf("WARNING: ");
 971         else if(result==2)
 972                 printf("CRITICAL: ");
 973         else if(result==3)
 974                 printf("UNKNOWN: ");
 975
 976         /* we didn't receive any DHCPOFFERs */
 977         if(dhcp_offer_list==NULL){
 978                 printf(_("No DHCPOFFERs were received.\n"));
 979                 return result;
 980                 }
 981
 982         printf(_("Received %d DHCPOFFER(s)"),valid_responses);
 983
 984         if(requested_servers>0)
 985                 printf(_(", %s%d of %d requested servers responded"),((requested_responses<requested_servers) && requested_responses>0)?"only ":"",requested_responses,requested_servers);
 986
 987         if(request_specific_address==TRUE)
 988                 printf(_(", requested address (%s) was %soffered"),inet_ntoa(requested_address),(received_requested_address==TRUE)?"":_("not "));
 989
 990         printf(_(", max lease time = "));
 991         if(max_lease_time==DHCP_INFINITE_TIME)
 992                 printf(_("Infinity"));
 993         else
 994                 printf("%lu sec",(unsigned long)max_lease_time);
 995
 996         printf(".\n");
 997
 998         return result;
 999         }
1000
1001
1002 /* process command-line arguments */
1003 int process_arguments(int argc, char **argv){
1004         int c;
1005
1006         if(argc<1)
1007                 return ERROR;
1008
1009         c=0;
1010         while((c+=(call_getopt(argc-c,&argv[c])))<argc){
1011
1012                 /*
1013                 if(is_option(argv[c]))
1014                         continue;
1015                 */
1016                 }
1017
1018         return validate_arguments();
1019         }
1020
1021
1022
1023 int call_getopt(int argc, char **argv){
1024         int c=0;
1025         int i=0;
1026         struct in_addr ipaddress;
1027
1028         int option_index = 0;
1029         static struct option long_options[] =
1030         {
1031                 {"serverip",       required_argument,0,'s'},
1032                 {"requestedip",    required_argument,0,'r'},
1033                 {"timeout",        required_argument,0,'t'},
1034                 {"interface",      required_argument,0,'i'},
1035                 {"verbose",        no_argument,      0,'v'},
1036                 {"version",        no_argument,      0,'V'},
1037                 {"help",           no_argument,      0,'h'},
1038                 {0,0,0,0}
1039         };
1040
1041         while(1){
1042                 c=getopt_long(argc,argv,"+hVvt:s:r:t:i:",long_options,&option_index);
1043
1044                 i++;
1045
1046                 if(c==-1||c==EOF||c==1)
1047                         break;
1048
1049                 switch(c){
1050                 case 'w':
1051                 case 'r':
1052                 case 't':
1053                 case 'i':
1054                         i++;
1055                         break;
1056                 default:
1057                         break;
1058                         }
1059
1060                 switch(c){
1061
1062                 case 's': /* DHCP server address */
1063                         if(inet_aton(optarg,&ipaddress))
1064                                 add_requested_server(ipaddress);
1065                         /*
1066                         else
1067                                 usage("Invalid server IP address\n");
1068                         */
1069                         break;
1070
1071                 case 'r': /* address we are requested from DHCP servers */
1072                         if(inet_aton(optarg,&ipaddress)){
1073                                 requested_address=ipaddress;
1074                                 request_specific_address=TRUE;
1075                                 }
1076                         /*
1077                         else
1078                                 usage("Invalid requested IP address\n");
1079                         */
1080                         break;
1081
1082                 case 't': /* timeout */
1083
1084                         /*
1085                         if(is_intnonneg(optarg))
1086                         */
1087                         if(atoi(optarg)>0)
1088                                 dhcpoffer_timeout=atoi(optarg);
1089                         /*
1090                         else
1091                                 usage("Time interval must be a nonnegative integer\n");
1092                         */
1093                         break;
1094
1095                 case 'i': /* interface name */
1096
1097                         strncpy(network_interface_name,optarg,sizeof(network_interface_name)-1);
1098                         network_interface_name[sizeof(network_interface_name)-1]='\x0';
1099
1100                         break;
1101
1102                 case 'V': /* version */
1103                         print_revision(progname,revision);
1104                         exit(STATE_OK);
1105
1106                 case 'h': /* help */
1107                         print_help();
1108                         exit(STATE_OK);
1109
1110                 case 'v': /* verbose */
1111                         verbose=1;
1112                         break;
1113
1114                 case '?': /* help */
1115                         usage5 ();
1116                         break;
1117
1118                 default:
1119                         break;
1120                         }
1121                 }
1122
1123         return i;
1124         }
1125
1126
1127 int validate_arguments(void){
1128
1129         return OK;
1130         }
1131
1132
1133 #if defined(__sun__) || defined(__solaris__) || defined(__hpux__)
1134 /* Kompf 2000-2003      see ACKNOWLEDGEMENTS */
1135
1136 /* get a message from a stream; return type of message */
1137 static int get_msg(int fd){
1138         int flags = 0;
1139         int res, ret;
1140         ctl_area[0] = 0;
1141         dat_area[0] = 0;
1142         ret = 0;
1143         res = getmsg(fd, &ctl, &dat, &flags);
1144
1145         if(res < 0){
1146                 if(errno == EINTR){
1147                         return(GOT_INTR);
1148                         }
1149                 else{
1150                         printf("%s\n", "get_msg FAILED.");
1151                         return(GOT_ERR);
1152                         }
1153                 }
1154         if(ctl.len > 0){
1155                 ret |= GOT_CTRL;
1156                 }
1157         if(dat.len > 0){
1158                 ret |= GOT_DATA;
1159                 }
1160
1161         return(ret);
1162         }
1163
1164 /* verify that dl_primitive in ctl_area = prim */
1165 static int check_ctrl(int prim){
1166         dl_error_ack_t *err_ack = (dl_error_ack_t *)ctl_area;
1167
1168         if(err_ack->dl_primitive != prim){
1169                 printf(_("Error: DLPI stream API failed to get MAC in check_ctrl: %s.\n"), strerror(errno));
1170                 exit(STATE_UNKNOWN);
1171                 }
1172
1173         return 0;
1174         }
1175
1176 /* put a control message on a stream */
1177 static int put_ctrl(int fd, int len, int pri){
1178
1179         ctl.len = len;
1180         if(putmsg(fd, &ctl, 0, pri) < 0){
1181                 printf(_("Error: DLPI stream API failed to get MAC in put_ctrl/putmsg(): %s.\n"), strerror(errno));
1182                 exit(STATE_UNKNOWN);
1183                 }
1184
1185         return  0;
1186         }
1187
1188 /* put a control + data message on a stream */
1189 static int put_both(int fd, int clen, int dlen, int pri){
1190
1191         ctl.len = clen;
1192         dat.len = dlen;
1193         if(putmsg(fd, &ctl, &dat, pri) < 0){
1194                 printf(_("Error: DLPI stream API failed to get MAC in put_both/putmsg().\n"), strerror(errno));
1195                 exit(STATE_UNKNOWN);
1196                 }
1197
1198         return  0;
1199         }
1200
1201 /* open file descriptor and attach */
1202 static int dl_open(const char *dev, int unit, int *fd){
1203         dl_attach_req_t *attach_req = (dl_attach_req_t *)ctl_area;
1204
1205         if((*fd = open(dev, O_RDWR)) == -1){
1206                 printf(_("Error: DLPI stream API failed to get MAC in dl_attach_req/open(%s..): %s.\n"), dev, strerror(errno));
1207                 exit(STATE_UNKNOWN);
1208                 }
1209         attach_req->dl_primitive = DL_ATTACH_REQ;
1210         attach_req->dl_ppa = unit;
1211         put_ctrl(*fd, sizeof(dl_attach_req_t), 0);
1212         get_msg(*fd);
1213         return check_ctrl(DL_OK_ACK);
1214         }
1215
1216 /* send DL_BIND_REQ */
1217 static int dl_bind(int fd, int sap, u_char *addr){
1218         dl_bind_req_t *bind_req = (dl_bind_req_t *)ctl_area;
1219         dl_bind_ack_t *bind_ack = (dl_bind_ack_t *)ctl_area;
1220
1221         bind_req->dl_primitive = DL_BIND_REQ;
1222         bind_req->dl_sap = sap;
1223         bind_req->dl_max_conind = 1;
1224         bind_req->dl_service_mode = DL_CLDLS;
1225         bind_req->dl_conn_mgmt = 0;
1226         bind_req->dl_xidtest_flg = 0;
1227         put_ctrl(fd, sizeof(dl_bind_req_t), 0);
1228         get_msg(fd);
1229         if (GOT_ERR == check_ctrl(DL_BIND_ACK)){
1230                 printf(_("Error: DLPI stream API failed to get MAC in dl_bind/check_ctrl(): %s.\n"), strerror(errno));
1231                 exit(STATE_UNKNOWN);
1232                 }
1233         bcopy((u_char *)bind_ack + bind_ack->dl_addr_offset, addr,
1234               bind_ack->dl_addr_length);
1235
1236         return 0;
1237         }
1238
1239 /***********************************************************************
1240  * interface:
1241  * function mac_addr_dlpi - get the mac address of the interface with
1242  *                          type dev (eg lnc, hme) and unit (0, 1 ..)
1243  *
1244  * parameter: addr: an array of six bytes, has to be allocated by the caller
1245  *
1246  * return: 0 if OK, -1 if the address could not be determined
1247  *
1248  *
1249  ***********************************************************************/
1250
1251 long mac_addr_dlpi( const char *dev, int unit, u_char  *addr){
1252         int fd;
1253         u_char mac_addr[25];
1254
1255         if(GOT_ERR != dl_open(dev, unit, &fd)){
1256                 if(GOT_ERR != dl_bind(fd, INSAP, mac_addr)){
1257                         bcopy( mac_addr, addr, 6);
1258                         return 0;
1259                         }
1260                 }
1261         close(fd);
1262
1263         return -1;
1264         }
1265
1266 /* Kompf 2000-2003 */
1267 #endif
1268
1269
1270 /* print usage help */
1271 void print_help(void){
1272
1273         print_revision(progname,revision);
1274
1275         printf("Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)\n");
1276         printf (COPYRIGHT, copyright, email);
1277
1278         printf("%s\n", _("This plugin tests the availability of DHCP servers on a network."));
1279
1280   printf ("\n\n");
1281
1282         print_usage();
1283
1284         printf (_(UT_HELP_VRSN));
1285
1286         printf (_(UT_VERBOSE));
1287
1288         printf (" %s\n", "-s, --serverip=IPADDRESS");
1289   printf ("    %s\n", _("IP address of DHCP server that we must hear from"));
1290   printf (" %s\n", "-r, --requestedip=IPADDRESS");
1291   printf ("    %s\n", _("IP address that should be offered by at least one DHCP server"));
1292   printf (" %s\n", "-t, --timeout=INTEGER");
1293   printf ("    %s\n", _("Seconds to wait for DHCPOFFER before timeout occurs"));
1294   printf (" %s\n", "-i, --interface=STRING");
1295   printf ("    %s\n", _("Interface to to use for listening (i.e. eth0)"));
1296
1297         return;
1298         }
1299
1300
1301 void
1302 print_usage(void){
1303
1304   printf (_("Usage:"));
1305   printf ("%s [-s serverip] [-r requestedip] [-t timeout] [-i interface] [-v]\n",progname);
1306
1307         return;
1308         }
1309
1310
1311