contrib/check_dhcp.c

   1 /******************************************************************************
   2 *
   3 * CHECK_DHCP.C
   4 *
   5 * Program: DHCP plugin for Nagios
   6 * License: GPL
   7 * Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)
   8 *
   9 * License Information:
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 *
  25 *****************************************************************************/
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <unistd.h>
  32 #include <sys/time.h>
  33 #include <sys/ioctl.h>
  34 #include <fcntl.h>
  35 #include <features.h>
  36 #include <linux/if_ether.h>
  37 #include <getopt.h>
  38 #include <net/if.h>
  39 #include <sys/socket.h>
  40 #include <sys/types.h>
  41 #include <netinet/in.h>
  42 #include <arpa/inet.h>
  43 #include <netdb.h>
  44
  45 const char *progname = "check_dhcp";
  46
  47 /*#define DEBUG*/
  48 #define HAVE_GETOPT_H
  49
  50
  51 /**** Common definitions ****/
  52
  53 #define STATE_OK          0
  54 #define STATE_WARNING     1
  55 #define STATE_CRITICAL    2
  56 #define STATE_UNKNOWN     -1
  57
  58 #define OK                0
  59 #define ERROR             -1
  60
  61 #define FALSE             0
  62 #define TRUE              1
  63
  64
  65 /**** DHCP definitions ****/
  66
  67 #define MAX_DHCP_CHADDR_LENGTH           16
  68 #define MAX_DHCP_SNAME_LENGTH            64
  69 #define MAX_DHCP_FILE_LENGTH             128
  70 #define MAX_DHCP_OPTIONS_LENGTH          312
  71
  72
  73 typedef struct dhcp_packet_struct{
  74         u_int8_t  op;                   /* packet type */
  75         u_int8_t  htype;                /* type of hardware address for this machine (Ethernet, etc) */
  76         u_int8_t  hlen;                 /* length of hardware address (of this machine) */
  77         u_int8_t  hops;                 /* hops */
  78         u_int32_t xid;                  /* random transaction id number - chosen by this machine */
  79         u_int16_t secs;                 /* seconds used in timing */
  80         u_int16_t flags;                /* flags */
  81         struct in_addr ciaddr;          /* IP address of this machine (if we already have one) */
  82         struct in_addr yiaddr;          /* IP address of this machine (offered by the DHCP server) */
  83         struct in_addr siaddr;          /* IP address of DHCP server */
  84         struct in_addr giaddr;          /* IP address of DHCP relay */
  85         unsigned char chaddr [MAX_DHCP_CHADDR_LENGTH];      /* hardware address of this machine */
  86         char sname [MAX_DHCP_SNAME_LENGTH];    /* name of DHCP server */
  87         char file [MAX_DHCP_FILE_LENGTH];      /* boot file name (used for diskless booting?) */
  88         char options[MAX_DHCP_OPTIONS_LENGTH];  /* options */
  89         }dhcp_packet;
  90
  91
  92 typedef struct dhcp_offer_struct{
  93         struct in_addr server_address;   /* address of DHCP server that sent this offer */
  94         struct in_addr offered_address;  /* the IP address that was offered to us */
  95         u_int32_t lease_time;            /* lease time in seconds */
  96         u_int32_t renewal_time;          /* renewal time in seconds */
  97         u_int32_t rebinding_time;        /* rebinding time in seconds */
  98         struct dhcp_offer_struct *next;
  99         }dhcp_offer;
 100
 101
 102 typedef struct requested_server_struct{
 103         struct in_addr server_address;
 104         struct requested_server_struct *next;
 105         }requested_server;
 106
 107
 108 #define BOOTREQUEST     1
 109 #define BOOTREPLY       2
 110
 111 #define DHCPDISCOVER    1
 112 #define DHCPOFFER       2
 113 #define DHCPREQUEST     3
 114 #define DHCPDECLINE     4
 115 #define DHCPACK         5
 116 #define DHCPNACK        6
 117 #define DHCPRELEASE     7
 118
 119 #define DHCP_OPTION_MESSAGE_TYPE        53
 120 #define DHCP_OPTION_HOST_NAME           12
 121 #define DHCP_OPTION_BROADCAST_ADDRESS   28
 122 #define DHCP_OPTION_REQUESTED_ADDRESS   50
 123 #define DHCP_OPTION_LEASE_TIME          51
 124 #define DHCP_OPTION_RENEWAL_TIME        58
 125 #define DHCP_OPTION_REBINDING_TIME      59
 126
 127 #define DHCP_INFINITE_TIME              0xFFFFFFFF
 128
 129 #define DHCP_BROADCAST_FLAG 32768
 130
 131 #define DHCP_SERVER_PORT   67
 132 #define DHCP_CLIENT_PORT   68
 133
 134 #define ETHERNET_HARDWARE_ADDRESS            1     /* used in htype field of dhcp packet */
 135 #define ETHERNET_HARDWARE_ADDRESS_LENGTH     6     /* length of Ethernet hardware addresses */
 136
 137 unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH]="";
 138
 139 char network_interface_name[8]="eth0";
 140
 141 u_int32_t packet_xid=0;
 142
 143 u_int32_t dhcp_lease_time=0;
 144 u_int32_t dhcp_renewal_time=0;
 145 u_int32_t dhcp_rebinding_time=0;
 146
 147 int dhcpoffer_timeout=2;
 148
 149 dhcp_offer *dhcp_offer_list=NULL;
 150 requested_server *requested_server_list=NULL;
 151
 152 int valid_responses=0;     /* number of valid DHCPOFFERs we received */
 153 int requested_servers=0;
 154 int requested_responses=0;
 155
 156 int request_specific_address=FALSE;
 157 int received_requested_address=FALSE;
 158 struct in_addr requested_address;
 159
 160
 161 int process_arguments(int, char **);
 162 int call_getopt(int, char **);
 163 int validate_arguments(void);
 164 void print_usage(void);
 165 void print_help(void);
 166
 167 int get_hardware_address(int,char *);
 168
 169 int send_dhcp_discover(int);
 170 int get_dhcp_offer(int);
 171
 172 int get_results(void);
 173
 174 int add_dhcp_offer(struct in_addr,dhcp_packet *);
 175 int free_dhcp_offer_list(void);
 176 int free_requested_server_list(void);
 177
 178 int create_dhcp_socket(void);
 179 int close_dhcp_socket(int);
 180 int send_dhcp_packet(void *,int,int,struct sockaddr_in *);
 181 int receive_dhcp_packet(void *,int,int,int,struct sockaddr_in *);
 182
 183
 184
 185 int main(int argc, char **argv){
 186         int dhcp_socket;
 187         int result;
 188
 189         if(process_arguments(argc,argv)!=OK){
 190                 /*usage("Invalid command arguments supplied\n");*/
 191                 printf("Invalid command arguments supplied\n");
 192                 exit(STATE_UNKNOWN);
 193                 }
 194
 195
 196         /* create socket for DHCP communications */
 197         dhcp_socket=create_dhcp_socket();
 198
 199         /* get hardware address of client machine */
 200         get_hardware_address(dhcp_socket,network_interface_name);
 201
 202         /* send DHCPDISCOVER packet */
 203         send_dhcp_discover(dhcp_socket);
 204
 205         /* wait for a DHCPOFFER packet */
 206         get_dhcp_offer(dhcp_socket);
 207
 208         /* close socket we created */
 209         close_dhcp_socket(dhcp_socket);
 210
 211         /* determine state/plugin output to return */
 212         result=get_results();
 213
 214         /* free allocated memory */
 215         free_dhcp_offer_list();
 216         free_requested_server_list();
 217
 218         return result;
 219         }
 220
 221
 222
 223 /* determines hardware address on client machine */
 224 int get_hardware_address(int sock,char *interface_name){
 225         struct ifreq ifr;
 226
 227         strncpy((char *)&ifr.ifr_name,interface_name,sizeof(ifr.ifr_name));
 228
 229         /* try and grab hardware address of requested interface */
 230         if(ioctl(sock,SIOCGIFHWADDR,&ifr)<0){
 231                 printf("Error: Could not get hardware address of interface '%s'\n",interface_name);
 232                 exit(STATE_UNKNOWN);
 233                 }
 234
 235         memcpy(&client_hardware_address[0],&ifr.ifr_hwaddr.sa_data,6);
 236
 237 #ifdef DEBUG
 238         printf("Hardware address: %02x:%02x:%02x:",client_hardware_address[0],client_hardware_address[1],client_hardware_address[2]);
 239         printf("%02x:",client_hardware_address[3]);
 240         printf("%02x:%02x\n",client_hardware_address[4],client_hardware_address[5]);
 241         printf("\n");
 242 #endif
 243
 244         return OK;
 245         }
 246
 247
 248 /* sends a DHCPDISCOVER broadcast message in an attempt to find DHCP servers */
 249 int send_dhcp_discover(int sock){
 250         dhcp_packet discover_packet;
 251         struct sockaddr_in sockaddr_broadcast;
 252
 253
 254         /* clear the packet data structure */
 255         bzero(&discover_packet,sizeof(discover_packet));
 256
 257
 258         /* boot request flag (backward compatible with BOOTP servers) */
 259         discover_packet.op=BOOTREQUEST;
 260
 261         /* hardware address type */
 262         discover_packet.htype=ETHERNET_HARDWARE_ADDRESS;
 263
 264         /* length of our hardware address */
 265         discover_packet.hlen=ETHERNET_HARDWARE_ADDRESS_LENGTH;
 266
 267         discover_packet.hops=0;
 268
 269         /* transaction id is supposed to be random */
 270         srand(time(NULL));
 271         packet_xid=random();
 272         discover_packet.xid=htonl(packet_xid);
 273
 274         /**** WHAT THE HECK IS UP WITH THIS?!?  IF I DON'T MAKE THIS CALL, ONLY ONE SERVER RESPONSE IS PROCESSED!!!! ****/
 275         /* downright bizzarre... */
 276         ntohl(discover_packet.xid);
 277
 278         /*discover_packet.secs=htons(65535);*/
 279         discover_packet.secs=0xFF;
 280
 281         /* tell server it should broadcast its response */
 282         discover_packet.flags=htons(DHCP_BROADCAST_FLAG);
 283
 284         /* our hardware address */
 285         memcpy(discover_packet.chaddr,client_hardware_address,ETHERNET_HARDWARE_ADDRESS_LENGTH);
 286
 287         /* first four bytes of options field is magic cookie (as per RFC 2132) */
 288         discover_packet.options[0]='\x63';
 289         discover_packet.options[1]='\x82';
 290         discover_packet.options[2]='\x53';
 291         discover_packet.options[3]='\x63';
 292
 293         /* DHCP message type is embedded in options field */
 294         discover_packet.options[4]=DHCP_OPTION_MESSAGE_TYPE;    /* DHCP message type option identifier */
 295         discover_packet.options[5]='\x01';               /* DHCP message option length in bytes */
 296         discover_packet.options[6]=DHCPDISCOVER;
 297
 298         /* the IP address we're requesting */
 299         if(request_specific_address==TRUE){
 300                 discover_packet.options[7]=DHCP_OPTION_REQUESTED_ADDRESS;
 301                 discover_packet.options[8]='\x04';
 302                 memcpy(&discover_packet.options[9],&requested_address,sizeof(requested_address));
 303                 }
 304
 305         /* send the DHCPDISCOVER packet to broadcast address */
 306         sockaddr_broadcast.sin_family=AF_INET;
 307         sockaddr_broadcast.sin_port=htons(DHCP_SERVER_PORT);
 308         sockaddr_broadcast.sin_addr.s_addr=INADDR_BROADCAST;
 309         bzero(&sockaddr_broadcast.sin_zero,sizeof(sockaddr_broadcast.sin_zero));
 310
 311
 312 #ifdef DEBUG
 313         printf("DHCPDISCOVER to %s port %d\n",inet_ntoa(sockaddr_broadcast.sin_addr),ntohs(sockaddr_broadcast.sin_port));
 314         printf("DHCPDISCOVER XID: %lu (0x%X)\n",ntohl(discover_packet.xid),ntohl(discover_packet.xid));
 315         printf("DHCDISCOVER ciaddr:  %s\n",inet_ntoa(discover_packet.ciaddr));
 316         printf("DHCDISCOVER yiaddr:  %s\n",inet_ntoa(discover_packet.yiaddr));
 317         printf("DHCDISCOVER siaddr:  %s\n",inet_ntoa(discover_packet.siaddr));
 318         printf("DHCDISCOVER giaddr:  %s\n",inet_ntoa(discover_packet.giaddr));
 319 #endif
 320
 321         /* send the DHCPDISCOVER packet out */
 322         send_dhcp_packet(&discover_packet,sizeof(discover_packet),sock,&sockaddr_broadcast);
 323
 324 #ifdef DEBUG
 325         printf("\n\n");
 326 #endif
 327
 328         return OK;
 329         }
 330
 331
 332
 333
 334 /* waits for a DHCPOFFER message from one or more DHCP servers */
 335 int get_dhcp_offer(int sock){
 336         dhcp_packet offer_packet;
 337         struct sockaddr_in source;
 338         int result=OK;
 339         int timeout=1;
 340         int responses=0;
 341         int x;
 342         time_t start_time;
 343         time_t current_time;
 344
 345         time(&start_time);
 346
 347         /* receive as many responses as we can */
 348         for(responses=0,valid_responses=0;;){
 349
 350                 time(&current_time);
 351                 if((current_time-start_time)>=dhcpoffer_timeout)
 352                         break;
 353
 354 #ifdef DEBUG
 355                 printf("\n\n");
 356 #endif
 357
 358                 bzero(&source,sizeof(source));
 359                 bzero(&offer_packet,sizeof(offer_packet));
 360
 361                 result=OK;
 362                 result=receive_dhcp_packet(&offer_packet,sizeof(offer_packet),sock,dhcpoffer_timeout,&source);
 363
 364                 if(result!=OK){
 365 #ifdef DEBUG
 366                         printf("Result=ERROR\n");
 367 #endif
 368                         continue;
 369                         }
 370                 else{
 371 #ifdef DEBUG
 372                         printf("Result=OK\n");
 373 #endif
 374                         responses++;
 375                         }
 376
 377 #ifdef DEBUG
 378                 printf("DHCPOFFER from IP address %s\n",inet_ntoa(source.sin_addr));
 379                 printf("DHCPOFFER XID: %lu (0x%X)\n",ntohl(offer_packet.xid),ntohl(offer_packet.xid));
 380 #endif
 381
 382                 /* check packet xid to see if its the same as the one we used in the discover packet */
 383                 if(ntohl(offer_packet.xid)!=packet_xid){
 384 #ifdef DEBUG
 385                         printf("DHCPOFFER XID (%lu) did not match DHCPDISCOVER XID (%lu) - ignoring packet\n",ntohl(offer_packet.xid),packet_xid);
 386 #endif
 387                         continue;
 388                         }
 389
 390                 /* check hardware address */
 391                 result=OK;
 392 #ifdef DEBUG
 393                 printf("DHCPOFFER chaddr: ");
 394 #endif
 395                 for(x=0;x<ETHERNET_HARDWARE_ADDRESS_LENGTH;x++){
 396 #ifdef DEBUG
 397                         printf("%02X",(unsigned char)offer_packet.chaddr[x]);
 398 #endif
 399                         if(offer_packet.chaddr[x]!=client_hardware_address[x]){
 400                                 result=ERROR;
 401                                 }
 402                         }
 403 #ifdef DEBUG
 404                 printf("\n");
 405 #endif
 406                 if(result==ERROR){
 407 #ifdef DEBUG
 408                         printf("DHCPOFFER hardware address did not match our own - ignoring packet\n");
 409 #endif
 410                         continue;
 411                         }
 412
 413 #ifdef DEBUG
 414                 printf("DHCPOFFER ciaddr: %s\n",inet_ntoa(offer_packet.ciaddr));
 415                 printf("DHCPOFFER yiaddr: %s\n",inet_ntoa(offer_packet.yiaddr));
 416                 printf("DHCPOFFER siaddr: %s\n",inet_ntoa(offer_packet.siaddr));
 417                 printf("DHCPOFFER giaddr: %s\n",inet_ntoa(offer_packet.giaddr));
 418 #endif
 419
 420                 add_dhcp_offer(source.sin_addr,&offer_packet);
 421
 422                 valid_responses++;
 423                 }
 424
 425 #ifdef DEBUG
 426         printf("Total responses seen on the wire: %d\n",responses);
 427         printf("Valid responses for this machine: %d\n",valid_responses);
 428 #endif
 429
 430         return OK;
 431         }
 432
 433
 434
 435 /* sends a DHCP packet */
 436 int send_dhcp_packet(void *buffer, int buffer_size, int sock, struct sockaddr_in *dest){
 437         struct sockaddr_in myname;
 438         int result;
 439
 440         result=sendto(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)dest,sizeof(*dest));
 441
 442 #ifdef DEBUG
 443         printf("send_dhcp_packet result: %d\n",result);
 444 #endif
 445
 446         if(result<0)
 447                 return ERROR;
 448
 449         return OK;
 450         }
 451
 452
 453
 454 /* receives a DHCP packet */
 455 int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, struct sockaddr_in *address){
 456         struct timeval tv;
 457         fd_set readfds;
 458         int recv_result;
 459         socklen_t address_size;
 460         struct sockaddr_in source_address;
 461
 462
 463         /* wait for data to arrive (up time timeout) */
 464         tv.tv_sec=timeout;
 465         tv.tv_usec=0;
 466         FD_ZERO(&readfds);
 467         FD_SET(sock,&readfds);
 468         select(sock+1,&readfds,NULL,NULL,&tv);
 469
 470         /* make sure some data has arrived */
 471         if(!FD_ISSET(sock,&readfds)){
 472 #ifdef DEBUG
 473                 printf("No (more) data received\n");
 474 #endif
 475                 return ERROR;
 476                 }
 477
 478         else{
 479
 480                 /* 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
 481                    not being interpreted correctly.  sigh... */
 482                 bzero(&source_address,sizeof(source_address));
 483                 address_size=sizeof(source_address);
 484                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,MSG_PEEK,(struct sockaddr *)&source_address,&address_size);
 485 #ifdef DEBUG
 486                 printf("recv_result_1: %d\n",recv_result);
 487 #endif
 488                 recv_result=recvfrom(sock,(char *)buffer,buffer_size,0,(struct sockaddr *)&source_address,&address_size);
 489 #ifdef DEBUG
 490                 printf("recv_result_2: %d\n",recv_result);
 491 #endif
 492
 493                 if(recv_result==-1){
 494 #ifdef DEBUG
 495                         printf("recvfrom() failed, ");
 496                         printf("errno: (%d) -> %s\n",errno,strerror(errno));
 497 #endif
 498                         return ERROR;
 499                         }
 500                 else{
 501 #ifdef DEBUG
 502                         printf("receive_dhcp_packet() result: %d\n",recv_result);
 503                         printf("receive_dhcp_packet() source: %s\n",inet_ntoa(source_address.sin_addr));
 504 #endif
 505
 506                         memcpy(address,&source_address,sizeof(source_address));
 507                         return OK;
 508                         }
 509                 }
 510
 511         return OK;
 512         }
 513
 514
 515
 516 /* creates a socket for DHCP communication */
 517 int create_dhcp_socket(void){
 518         struct sockaddr_in myname;
 519         struct ifreq interface;
 520         int sock;
 521         int flag=1;
 522
 523         /* Set up the address we're going to bind to. */
 524         bzero(&myname,sizeof(myname));
 525         myname.sin_family=AF_INET;
 526         myname.sin_port=htons(DHCP_CLIENT_PORT);
 527         myname.sin_addr.s_addr=INADDR_ANY;                 /* listen on any address */
 528         bzero(&myname.sin_zero,sizeof(myname.sin_zero));
 529
 530         /* create a socket for DHCP communications */
 531         sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
 532         if(sock<0){
 533                 printf("Error: Could not create socket!\n");
 534                 exit(STATE_UNKNOWN);
 535                 }
 536
 537 #ifdef DEBUG
 538         printf("DHCP socket: %d\n",sock);
 539 #endif
 540
 541         /* set the reuse address flag so we don't get errors when restarting */
 542         flag=1;
 543         if(setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&flag,sizeof(flag))<0){
 544                 printf("Error: Could not set reuse address option on DHCP socket!\n");
 545                 exit(STATE_UNKNOWN);
 546                 }
 547
 548         /* set the broadcast option - we need this to listen to DHCP broadcast messages */
 549         if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
 550                 printf("Error: Could not set broadcast option on DHCP socket!\n");
 551                 exit(STATE_UNKNOWN);
 552                 }
 553
 554         /* bind socket to interface */
 555         strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ);
 556         if(setsockopt(sock,SOL_SOCKET,SO_BINDTODEVICE,(char *)&interface,sizeof(interface))<0){
 557                 printf("Error: Could not bind socket to interface %s.  Check your privileges...\n",network_interface_name);
 558                 exit(STATE_UNKNOWN);
 559                 }
 560
 561         /* bind the socket */
 562         if(bind(sock,(struct sockaddr *)&myname,sizeof(myname))<0){
 563                 printf("Error: Could not bind to DHCP socket (port %d)!  Check your privileges...\n",DHCP_CLIENT_PORT);
 564                 exit(STATE_UNKNOWN);
 565                 }
 566
 567         return sock;
 568         }
 569
 570
 571
 572
 573
 574 /* closes DHCP socket */
 575 int close_dhcp_socket(int sock){
 576
 577         close(sock);
 578
 579         return OK;
 580         }
 581
 582
 583
 584
 585 /* adds a requested server address to list in memory */
 586 int add_requested_server(struct in_addr server_address){
 587         requested_server *new_server;
 588
 589         new_server=(requested_server *)malloc(sizeof(requested_server));
 590         if(new_server==NULL)
 591                 return ERROR;
 592
 593         new_server->server_address=server_address;
 594
 595         new_server->next=requested_server_list;
 596         requested_server_list=new_server;
 597
 598         requested_servers++;
 599
 600 #ifdef DEBUG
 601         printf("Requested server address: %s\n",inet_ntoa(new_server->server_address));
 602 #endif
 603
 604         return OK;
 605         }
 606
 607
 608
 609
 610 /* adds a DHCP OFFER to list in memory */
 611 int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
 612         dhcp_offer *new_offer;
 613         int x;
 614         int y;
 615         unsigned option_type;
 616         unsigned option_length;
 617
 618         if(offer_packet==NULL)
 619                 return ERROR;
 620
 621         /* process all DHCP options present in the packet */
 622         for(x=4;x<MAX_DHCP_OPTIONS_LENGTH;){
 623
 624                 /* end of options (0 is really just a pad, but bail out anyway) */
 625                 if((int)offer_packet->options[x]==-1 || (int)offer_packet->options[x]==0)
 626                         break;
 627
 628                 /* get option type */
 629                 option_type=offer_packet->options[x++];
 630
 631                 /* get option length */
 632                 option_length=offer_packet->options[x++];
 633
 634 #ifdef DEBUG
 635                 printf("Option: %d (0x%02X)\n",option_type,option_length);
 636 #endif
 637
 638                 /* get option data */
 639                 if(option_type==DHCP_OPTION_LEASE_TIME)
 640                         dhcp_lease_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
 641                 if(option_type==DHCP_OPTION_RENEWAL_TIME)
 642                         dhcp_renewal_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
 643                 if(option_type==DHCP_OPTION_REBINDING_TIME)
 644                         dhcp_rebinding_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
 645
 646                 /* skip option data we're ignoring */
 647                 else
 648                         for(y=0;y<option_length;y++,x++);
 649                 }
 650
 651 #ifdef DEBUG
 652         if(dhcp_lease_time==DHCP_INFINITE_TIME)
 653                 printf("Lease Time: Infinite\n");
 654         else
 655                 printf("Lease Time: %lu seconds\n",(unsigned long)dhcp_lease_time);
 656         if(dhcp_renewal_time==DHCP_INFINITE_TIME)
 657                 printf("Renewal Time: Infinite\n");
 658         else
 659                 printf("Renewal Time: %lu seconds\n",(unsigned long)dhcp_renewal_time);
 660         if(dhcp_rebinding_time==DHCP_INFINITE_TIME)
 661                 printf("Rebinding Time: Infinite\n");
 662         printf("Rebinding Time: %lu seconds\n",(unsigned long)dhcp_rebinding_time);
 663 #endif
 664
 665         new_offer=(dhcp_offer *)malloc(sizeof(dhcp_offer));
 666
 667         if(new_offer==NULL)
 668                 return ERROR;
 669
 670
 671         new_offer->server_address=source;
 672         new_offer->offered_address=offer_packet->yiaddr;
 673         new_offer->lease_time=dhcp_lease_time;
 674         new_offer->renewal_time=dhcp_renewal_time;
 675         new_offer->rebinding_time=dhcp_rebinding_time;
 676
 677
 678 #ifdef DEBUG
 679         printf("Added offer from server @ %s",inet_ntoa(new_offer->server_address));
 680         printf(" of IP address %s\n",inet_ntoa(new_offer->offered_address));
 681 #endif
 682
 683         /* add new offer to head of list */
 684         new_offer->next=dhcp_offer_list;
 685         dhcp_offer_list=new_offer;
 686
 687         return OK;
 688         }
 689
 690
 691
 692
 693 /* frees memory allocated to DHCP OFFER list */
 694 int free_dhcp_offer_list(void){
 695         dhcp_offer *this_offer;
 696         dhcp_offer *next_offer;
 697
 698         for(this_offer=dhcp_offer_list;this_offer!=NULL;this_offer=next_offer){
 699                 next_offer=this_offer->next;
 700                 free(this_offer);
 701                 }
 702
 703         return OK;
 704         }
 705
 706
 707
 708
 709 /* frees memory allocated to requested server list */
 710 int free_requested_server_list(void){
 711         requested_server *this_server;
 712         requested_server *next_server;
 713
 714         for(this_server=requested_server_list;this_server!=NULL;this_server=next_server){
 715                 next_server=this_server->next;
 716                 free(this_server);
 717                 }
 718
 719         return OK;
 720         }
 721
 722
 723 /* gets state and plugin output to return */
 724 int get_results(void){
 725         dhcp_offer *temp_offer;
 726         requested_server *temp_server;
 727         int result;
 728         u_int32_t max_lease_time=0;
 729
 730         received_requested_address=FALSE;
 731
 732         /* checks responses from requested servers */
 733         requested_responses=0;
 734         if(requested_servers>0){
 735
 736                 for(temp_server=requested_server_list;temp_server!=NULL;temp_server=temp_server->next){
 737
 738                         for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
 739
 740                                 /* get max lease time we were offered */
 741                                 if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
 742                                         max_lease_time=temp_offer->lease_time;
 743
 744                                 /* see if we got the address we requested */
 745                                 if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
 746                                         received_requested_address=TRUE;
 747
 748                                 /* see if the servers we wanted a response from talked to us or not */
 749                                 if(!memcmp(&temp_offer->server_address,&temp_server->server_address,sizeof(temp_server->server_address))){
 750 #ifdef DEBUG
 751                                         printf("DHCP Server Match: Offerer=%s",inet_ntoa(temp_offer->server_address));
 752                                         printf(" Requested=%s\n",inet_ntoa(temp_server->server_address));
 753 #endif
 754                                         requested_responses++;
 755                                         }
 756                                 }
 757                         }
 758
 759                 }
 760
 761         /* else check and see if we got our requested address from any server */
 762         else{
 763
 764                 for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
 765
 766                         /* get max lease time we were offered */
 767                         if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
 768                                 max_lease_time=temp_offer->lease_time;
 769
 770                         /* see if we got the address we requested */
 771                         if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
 772                                 received_requested_address=TRUE;
 773                         }
 774                 }
 775
 776         result=STATE_OK;
 777         if(valid_responses==0)
 778                 result=STATE_CRITICAL;
 779         else if(requested_servers>0 && requested_responses==0)
 780                 result=STATE_CRITICAL;
 781         else if(requested_responses<requested_servers)
 782                 result=STATE_WARNING;
 783         else if(request_specific_address==TRUE && received_requested_address==FALSE)
 784                 result=STATE_WARNING;
 785
 786
 787         printf("DHCP %s: ",(result==STATE_OK)?"ok":"problem");
 788
 789         /* we didn't receive any DHCPOFFERs */
 790         if(dhcp_offer_list==NULL){
 791                 printf("No DHCPOFFERs were received.\n");
 792                 return result;
 793                 }
 794
 795         printf("Received %d DHCPOFFER(s)",valid_responses);
 796
 797         if(requested_servers>0)
 798                 printf(", %s%d of %d requested servers responded",((requested_responses<requested_servers) && requested_responses>0)?"only ":"",requested_responses,requested_servers);
 799
 800         if(request_specific_address==TRUE)
 801                 printf(", requested address (%s) was %soffered",inet_ntoa(requested_address),(received_requested_address==TRUE)?"":"not ");
 802
 803         printf(", max lease time = ");
 804         if(max_lease_time==DHCP_INFINITE_TIME)
 805                 printf("Infinity");
 806         else
 807                 printf("%lu sec",(unsigned long)max_lease_time);
 808
 809         printf(".\n");
 810
 811         return result;
 812         }
 813
 814
 815
 816
 817
 818
 819 /* print usage help */
 820 void print_help(void){
 821
 822         /*print_revision(progname,"$Revision$");*/
 823
 824         printf("Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)\n\n");
 825         printf("This plugin tests the availability of DHCP servers on a network.\n\n");
 826
 827         print_usage();
 828
 829         printf
 830                 ("\nOptions:\n"
 831                  " -s, --serverip=IPADDRESS\n"
 832                  "   IP address of DHCP server that we must hear from\n"
 833                  " -r, --requestedip=IPADDRESS\n"
 834                  "   IP address that should be offered by at least one DHCP server\n"
 835                  " -t, --timeout=INTEGER\n"
 836                  "   Seconds to wait for DHCPOFFER before timeout occurs\n"
 837                  " -i, --interface=STRING\n"
 838                  "   Interface to to use for listening (i.e. eth0)\n"
 839                  " -v, --verbose\n"
 840                  "   Print extra information (command-line use only)\n"
 841                  " -h, --help\n"
 842                  "   Print detailed help screen\n"
 843                  " -V, --version\n"
 844                  "   Print version information\n\n"
 845                  );
 846
 847         /*support();*/
 848
 849         return;
 850         }
 851
 852
 853 /* prints usage information */
 854 void print_usage(void){
 855
 856         printf("Usage: %s [-s serverip] [-r requestedip] [-t timeout] [-i interface]\n",progname);
 857         printf("       %s --help\n",progname);
 858         printf("       %s --version\n",progname);
 859
 860         return;
 861         }
 862
 863
 864
 865
 866 /* process command-line arguments */
 867 int process_arguments(int argc, char **argv){
 868         int c;
 869
 870         if(argc<1)
 871                 return ERROR;
 872
 873         c=0;
 874         while((c+=(call_getopt(argc-c,&argv[c])))<argc){
 875
 876                 /*
 877                 if(is_option(argv[c]))
 878                         continue;
 879                 */
 880                 }
 881
 882         return validate_arguments();
 883         }
 884
 885
 886
 887 int call_getopt(int argc, char **argv){
 888         int c=0;
 889         int i=0;
 890         struct in_addr ipaddress;
 891
 892 #ifdef HAVE_GETOPT_H
 893         int option_index = 0;
 894         static struct option long_options[] =
 895         {
 896                 {"serverip",       required_argument,0,'s'},
 897                 {"requestedip",    required_argument,0,'r'},
 898                 {"timeout",        required_argument,0,'t'},
 899                 {"interface",      required_argument,0,'i'},
 900                 {"verbose",        no_argument,      0,'v'},
 901                 {"version",        no_argument,      0,'V'},
 902                 {"help",           no_argument,      0,'h'},
 903                 {0,0,0,0}
 904         };
 905 #endif
 906
 907         while(1){
 908 #ifdef HAVE_GETOPT_H
 909                 c=getopt_long(argc,argv,"+hVvt:s:r:t:i:",long_options,&option_index);
 910 #else
 911                 c=getopt(argc,argv,"+?hVvt:s:r:t:i:");
 912 #endif
 913
 914                 i++;
 915
 916                 if(c==-1||c==EOF||c==1)
 917                         break;
 918
 919                 switch(c){
 920                 case 'w':
 921                 case 'r':
 922                 case 't':
 923                 case 'i':
 924                         i++;
 925                         break;
 926                 default:
 927                         break;
 928                         }
 929
 930                 switch(c){
 931
 932                 case 's': /* DHCP server address */
 933                         if(inet_aton(optarg,&ipaddress))
 934                                 add_requested_server(ipaddress);
 935                         /*
 936                         else
 937                                 usage("Invalid server IP address\n");
 938                         */
 939                         break;
 940
 941                 case 'r': /* address we are requested from DHCP servers */
 942                         if(inet_aton(optarg,&ipaddress)){
 943                                 requested_address=ipaddress;
 944                                 request_specific_address=TRUE;
 945                                 }
 946                         /*
 947                         else
 948                                 usage("Invalid requested IP address\n");
 949                         */
 950                         break;
 951
 952                 case 't': /* timeout */
 953
 954                         /*
 955                         if(is_intnonneg(optarg))
 956                         */
 957                         if(atoi(optarg)>0)
 958                                 dhcpoffer_timeout=atoi(optarg);
 959                         /*
 960                         else
 961                                 usage("Time interval must be a nonnegative integer\n");
 962                         */
 963                         break;
 964
 965                 case 'i': /* interface name */
 966
 967                         strncpy(network_interface_name,optarg,sizeof(network_interface_name)-1);
 968                         network_interface_name[sizeof(network_interface_name)-1]='\x0';
 969
 970                         break;
 971
 972                 case 'V': /* version */
 973
 974                         /*print_revision(progname,"$Revision$");*/
 975                         exit(STATE_OK);
 976
 977                 case 'h': /* help */
 978
 979                         print_help();
 980                         exit(STATE_OK);
 981
 982                 case '?': /* help */
 983
 984                         /*usage("Invalid argument\n");*/
 985                         break;
 986
 987                 default:
 988                         break;
 989                         }
 990                 }
 991
 992         return i;
 993         }
 994
 995
 996
 997 int validate_arguments(void){
 998
 999         return OK;
1000         }
1001