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1/******************************************************************************
2*
3* CHECK_DHCP.C
4*
5* Program: DHCP plugin for Nagios
6* License: GPL
7* Copyright (c) 2001 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#define 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
73typedef 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
92typedef 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
102typedef 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
137unsigned char client_hardware_address[MAX_DHCP_CHADDR_LENGTH]="";
138
139char network_interface_name[8]="eth0";
140
141u_int32_t packet_xid=0;
142
143u_int32_t dhcp_lease_time=0;
144u_int32_t dhcp_renewal_time=0;
145u_int32_t dhcp_rebinding_time=0;
146
147int dhcpoffer_timeout=2;
148
149dhcp_offer *dhcp_offer_list=NULL;
150requested_server *requested_server_list=NULL;
151
152int valid_responses=0; /* number of valid DHCPOFFERs we received */
153int requested_servers=0;
154int requested_responses=0;
155
156int request_specific_address=FALSE;
157int received_requested_address=FALSE;
158struct in_addr requested_address;
159
160
161int process_arguments(int, char **);
162int call_getopt(int, char **);
163int validate_arguments(void);
164void print_usage(void);
165void print_help(void);
166
167int get_hardware_address(int,char *);
168
169int send_dhcp_discover(int);
170int get_dhcp_offer(int);
171
172int get_results(void);
173
174int add_dhcp_offer(struct in_addr,dhcp_packet *);
175int free_dhcp_offer_list(void);
176int free_requested_server_list(void);
177
178int create_dhcp_socket(void);
179int close_dhcp_socket(int);
180int send_dhcp_packet(void *,int,int,struct sockaddr_in *);
181int receive_dhcp_packet(void *,int,int,int,struct sockaddr_in *);
182
183
184
185int 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 */
224int 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 */
249int 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 */
335int 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 */
436int 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_in *)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 */
455int 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 recieved\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 recv_result=recvfrom(sock,(char *)buffer,buffer_size,MSG_PEEK,(struct sockaddr_in *)&source_address,&address_size);
484#ifdef DEBUG
485 printf("recv_result_1: %d\n",recv_result);
486#endif
487 recv_result=recvfrom(sock,(char *)buffer,buffer_size,0,(struct sockaddr_in *)&source_address,&address_size);
488#ifdef DEBUG
489 printf("recv_result_2: %d\n",recv_result);
490#endif
491
492 if(recv_result==-1){
493#ifdef DEBUG
494 printf("recvfrom() failed, ");
495 printf("errno: (%d) -> %s\n",errno,strerror(errno));
496#endif
497 return ERROR;
498 }
499 else{
500#ifdef DEBUG
501 printf("receive_dhcp_packet() result: %d\n",recv_result);
502 printf("receive_dhcp_packet() source: %s\n",inet_ntoa(source_address.sin_addr));
503#endif
504
505 memcpy(address,&source_address,sizeof(source_address));
506 return OK;
507 }
508 }
509
510 return OK;
511 }
512
513
514
515/* creates a socket for DHCP communication */
516int create_dhcp_socket(void){
517 struct sockaddr_in myname;
518 int sock;
519 int flag=1;
520
521 /* Set up the address we're going to bind to. */
522 bzero(&myname,sizeof(myname));
523 myname.sin_family=AF_INET;
524 myname.sin_port=htons(DHCP_CLIENT_PORT);
525 myname.sin_addr.s_addr=INADDR_ANY; /* listen on any address */
526 bzero(&myname.sin_zero,sizeof(myname.sin_zero));
527
528 /* create a socket for DHCP communications */
529 sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
530 if(sock<0){
531 printf("Error: Could not create socket!\n");
532 exit(STATE_UNKNOWN);
533 }
534
535#ifdef DEBUG
536 printf("DHCP socket: %d\n",sock);
537#endif
538
539 /* set the reuse address flag so we don't get errors when restarting */
540 flag=1;
541 if(setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char *)&flag,sizeof(flag))<0){
542 printf("Error: Could not set reuse address option on DHCP socket!\n");
543 exit(STATE_UNKNOWN);
544 }
545
546 /* set the broadcast option - we need this to listen to DHCP broadcast messages */
547 if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST,(char *)&flag,sizeof flag)<0){
548 printf("Error: Could not set broadcast option on DHCP socket!\n");
549 exit(STATE_UNKNOWN);
550 }
551
552 /* bind the socket */
553 if(bind(sock,(struct sockaddr *)&myname,sizeof(myname))<0){
554 printf("Error: Could not bind to DHCP socket (port %d)! Check your privileges...\n",DHCP_CLIENT_PORT);
555 exit(STATE_UNKNOWN);
556 }
557
558 return sock;
559 }
560
561
562
563
564
565/* closes DHCP socket */
566int close_dhcp_socket(int sock){
567
568 close(sock);
569
570 return OK;
571 }
572
573
574
575
576/* adds a requested server address to list in memory */
577int add_requested_server(struct in_addr server_address){
578 requested_server *new_server;
579
580 new_server=(requested_server *)malloc(sizeof(requested_server));
581 if(new_server==NULL)
582 return ERROR;
583
584 new_server->server_address=server_address;
585
586 new_server->next=requested_server_list;
587 requested_server_list=new_server;
588
589 requested_servers++;
590
591#ifdef DEBUG
592 printf("Requested server address: %s\n",inet_ntoa(new_server->server_address));
593#endif
594
595 return OK;
596 }
597
598
599
600
601/* adds a DHCP OFFER to list in memory */
602int add_dhcp_offer(struct in_addr source,dhcp_packet *offer_packet){
603 dhcp_offer *new_offer;
604 int x;
605 int y;
606 unsigned option_type;
607 unsigned option_length;
608
609 if(offer_packet==NULL)
610 return ERROR;
611
612 /* process all DHCP options present in the packet */
613 for(x=4;x<MAX_DHCP_OPTIONS_LENGTH;){
614
615 /* end of options (0 is really just a pad, but bail out anyway) */
616 if((int)offer_packet->options[x]==-1 || (int)offer_packet->options[x]==0)
617 break;
618
619 /* get option type */
620 option_type=offer_packet->options[x++];
621
622 /* get option length */
623 option_length=offer_packet->options[x++];
624
625#ifdef DEBUG
626 printf("Option: %d (0x%02X)\n",option_type,option_length);
627#endif
628
629 /* get option data */
630 if(option_type==DHCP_OPTION_LEASE_TIME)
631 dhcp_lease_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
632 if(option_type==DHCP_OPTION_RENEWAL_TIME)
633 dhcp_renewal_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
634 if(option_type==DHCP_OPTION_REBINDING_TIME)
635 dhcp_rebinding_time=ntohl(*((u_int32_t *)&offer_packet->options[x]));
636
637 /* skip option data we're ignoring */
638 else
639 for(y=0;y<option_length;y++,x++);
640 }
641
642#ifdef DEBUG
643 if(dhcp_lease_time==DHCP_INFINITE_TIME)
644 printf("Lease Time: Infinite\n");
645 else
646 printf("Lease Time: %lu seconds\n",(unsigned long)dhcp_lease_time);
647 if(dhcp_renewal_time==DHCP_INFINITE_TIME)
648 printf("Renewal Time: Infinite\n");
649 else
650 printf("Renewal Time: %lu seconds\n",(unsigned long)dhcp_renewal_time);
651 if(dhcp_rebinding_time==DHCP_INFINITE_TIME)
652 printf("Rebinding Time: Infinite\n");
653 printf("Rebinding Time: %lu seconds\n",(unsigned long)dhcp_rebinding_time);
654#endif
655
656 new_offer=(dhcp_offer *)malloc(sizeof(dhcp_offer));
657
658 if(new_offer==NULL)
659 return ERROR;
660
661
662 new_offer->server_address=source;
663 new_offer->offered_address=offer_packet->yiaddr;
664 new_offer->lease_time=dhcp_lease_time;
665 new_offer->renewal_time=dhcp_renewal_time;
666 new_offer->rebinding_time=dhcp_rebinding_time;
667
668
669#ifdef DEBUG
670 printf("Added offer from server @ %s",inet_ntoa(new_offer->server_address));
671 printf(" of IP address %s\n",inet_ntoa(new_offer->offered_address));
672#endif
673
674 /* add new offer to head of list */
675 new_offer->next=dhcp_offer_list;
676 dhcp_offer_list=new_offer;
677
678 return OK;
679 }
680
681
682
683
684/* frees memory allocated to DHCP OFFER list */
685int free_dhcp_offer_list(void){
686 dhcp_offer *this_offer;
687 dhcp_offer *next_offer;
688
689 for(this_offer=dhcp_offer_list;this_offer!=NULL;this_offer=next_offer){
690 next_offer=this_offer->next;
691 free(this_offer);
692 }
693
694 return OK;
695 }
696
697
698
699
700/* frees memory allocated to requested server list */
701int free_requested_server_list(void){
702 requested_server *this_server;
703 requested_server *next_server;
704
705 for(this_server=requested_server_list;this_server!=NULL;this_server=next_server){
706 next_server=this_server->next;
707 free(this_server);
708 }
709
710 return OK;
711 }
712
713
714/* gets state and plugin output to return */
715int get_results(void){
716 dhcp_offer *temp_offer;
717 requested_server *temp_server;
718 int result;
719 u_int32_t max_lease_time=0;
720
721 received_requested_address=FALSE;
722
723 /* checks responses from requested servers */
724 requested_responses=0;
725 if(requested_servers>0){
726
727 for(temp_server=requested_server_list;temp_server!=NULL;temp_server=temp_server->next){
728
729 for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
730
731 /* get max lease time we were offered */
732 if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
733 max_lease_time=temp_offer->lease_time;
734
735 /* see if we got the address we requested */
736 if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
737 received_requested_address=TRUE;
738
739 /* see if the servers we wanted a response from talked to us or not */
740 if(!memcmp(&temp_offer->server_address,&temp_server->server_address,sizeof(temp_server->server_address))){
741#ifdef DEBUG
742 printf("DHCP Server Match: Offerer=%s",inet_ntoa(temp_offer->server_address));
743 printf(" Requested=%s\n",inet_ntoa(temp_server->server_address));
744#endif
745 requested_responses++;
746 }
747 }
748 }
749
750 }
751
752 /* else check and see if we got our requested address from any server */
753 else{
754
755 for(temp_offer=dhcp_offer_list;temp_offer!=NULL;temp_offer=temp_offer->next){
756
757 /* get max lease time we were offered */
758 if(temp_offer->lease_time>max_lease_time || temp_offer->lease_time==DHCP_INFINITE_TIME)
759 max_lease_time=temp_offer->lease_time;
760
761 /* see if we got the address we requested */
762 if(!memcmp(&requested_address,&temp_offer->offered_address,sizeof(requested_address)))
763 received_requested_address=TRUE;
764 }
765 }
766
767 result=STATE_OK;
768 if(valid_responses==0)
769 result=STATE_CRITICAL;
770 else if(requested_servers>0 && requested_responses==0)
771 result=STATE_CRITICAL;
772 else if(requested_responses<requested_servers)
773 result=STATE_WARNING;
774 else if(request_specific_address==TRUE && received_requested_address==FALSE)
775 result=STATE_WARNING;
776
777
778 printf("DHCP %s: ",(result==STATE_OK)?"ok":"problem");
779
780 /* we didn't receive any DHCPOFFERs */
781 if(dhcp_offer_list==NULL){
782 printf("No DHCPOFFERs were received.\n");
783 return result;
784 }
785
786 printf("Received %d DHCPOFFER(s)",valid_responses);
787
788 if(requested_servers>0)
789 printf(", %s%d of %d requested servers responded",((requested_responses<requested_servers) && requested_responses>0)?"only ":"",requested_responses,requested_servers);
790
791 if(request_specific_address==TRUE)
792 printf(", requested address (%s) was %soffered",inet_ntoa(requested_address),(received_requested_address==TRUE)?"":"not ");
793
794 printf(", max lease time = ");
795 if(max_lease_time==DHCP_INFINITE_TIME)
796 printf("Infinity");
797 else
798 printf("%lu sec",(unsigned long)max_lease_time);
799
800 printf(".\n");
801
802 return result;
803 }
804
805
806
807
808
809
810/* print usage help */
811void print_help(void){
812
813 /*print_revision(PROGNAME,"$Revision$");*/
814
815 printf("Copyright (c) 2001 Ethan Galstad (nagios@nagios.org)\n\n");
816 printf("This plugin tests the availability of DHCP servers on a network.\n\n");
817
818 print_usage();
819
820 printf
821 ("\nOptions:\n"
822 " -s, --serverip=IPADDRESS\n"
823 " IP address of DHCP server that we must hear from\n"
824 " -r, --requestedip=IPADDRESS\n"
825 " IP address that should be offered by at least one DHCP server\n"
826 " -t, --timeout=INTEGER\n"
827 " Seconds to wait for DHCPOFFER before timeout occurs\n"
828 " -i, --interface=STRING\n"
829 " Interface to to use for listening (i.e. eth0)\n"
830 " -v, --verbose\n"
831 " Print extra information (command-line use only)\n"
832 " -h, --help\n"
833 " Print detailed help screen\n"
834 " -V, --version\n"
835 " Print version information\n\n"
836 );
837
838 /*support();*/
839
840 return;
841 }
842
843
844/* prints usage information */
845void print_usage(void){
846
847 printf("Usage: %s [-s serverip] [-r requestedip] [-t timeout] [-i interface]\n",PROGNAME);
848 printf(" %s --help\n",PROGNAME);
849 printf(" %s --version\n",PROGNAME);
850
851 return;
852 }
853
854
855
856
857/* process command-line arguments */
858int process_arguments(int argc, char **argv){
859 int c;
860
861 if(argc<1)
862 return ERROR;
863
864 c=0;
865 while((c+=(call_getopt(argc-c,&argv[c])))<argc){
866
867 /*
868 if(is_option(argv[c]))
869 continue;
870 */
871 }
872
873 return validate_arguments();
874 }
875
876
877
878int call_getopt(int argc, char **argv){
879 int c=0;
880 int i=0;
881 struct in_addr ipaddress;
882
883#ifdef HAVE_GETOPT_H
884 int option_index = 0;
885 static struct option long_options[] =
886 {
887 {"serverip", required_argument,0,'s'},
888 {"requestedip", required_argument,0,'r'},
889 {"timeout", required_argument,0,'t'},
890 {"interface", required_argument,0,'i'},
891 {"verbose", no_argument, 0,'v'},
892 {"version", no_argument, 0,'V'},
893 {"help", no_argument, 0,'h'},
894 {0,0,0,0}
895 };
896#endif
897
898 while(1){
899#ifdef HAVE_GETOPT_H
900 c=getopt_long(argc,argv,"+hVvt:s:r:t:i:",long_options,&option_index);
901#else
902 c=getopt(argc,argv,"+?hVvt:s:r:t:i:");
903#endif
904
905 i++;
906
907 if(c==-1||c==EOF||c==1)
908 break;
909
910 switch(c){
911 case 'w':
912 case 'r':
913 case 't':
914 case 'i':
915 i++;
916 break;
917 default:
918 break;
919 }
920
921 switch(c){
922
923 case 's': /* DHCP server address */
924 if(inet_aton(optarg,&ipaddress))
925 add_requested_server(ipaddress);
926 /*
927 else
928 usage("Invalid server IP address\n");
929 */
930 break;
931
932 case 'r': /* address we are requested from DHCP servers */
933 if(inet_aton(optarg,&ipaddress)){
934 requested_address=ipaddress;
935 request_specific_address=TRUE;
936 }
937 /*
938 else
939 usage("Invalid requested IP address\n");
940 */
941 break;
942
943 case 't': /* timeout */
944
945 /*
946 if(is_intnonneg(optarg))
947 */
948 if(atoi(optarg)>0)
949 dhcpoffer_timeout=atoi(optarg);
950 /*
951 else
952 usage("Time interval must be a nonnegative integer\n");
953 */
954 break;
955
956 case 'i': /* interface name */
957
958 strncpy(network_interface_name,optarg,sizeof(network_interface_name)-1);
959 network_interface_name[sizeof(network_interface_name)-1]='\x0';
960
961 break;
962
963 case 'V': /* version */
964
965 /*print_revision(PROGNAME,"$Revision$");*/
966 exit(STATE_OK);
967
968 case 'h': /* help */
969
970 print_help();
971 exit(STATE_OK);
972
973 case '?': /* help */
974
975 /*usage("Invalid argument\n");*/
976 break;
977
978 default:
979 break;
980 }
981 }
982
983 return i;
984 }
985
986
987
988int validate_arguments(void){
989
990 return OK;
991 }
992