plugins/check_ntp_time.c

   1 /*****************************************************************************
   2 *
   3 * Monitoring check_ntp_time plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 2006 Sean Finney <seanius@seanius.net>
   7 * Copyright (c) 2006-2008 Monitoring Plugins Development Team
   8 *
   9 * Description:
  10 *
  11 * This file contains the check_ntp_time plugin
  12 *
  13 * This plugin checks the clock offset between the local host and a
  14 * remote NTP server. It is independent of any commandline programs or
  15 * external libraries.
  16 *
  17 * If you'd rather want to monitor an NTP server, please use
  18 * check_ntp_peer.
  19 *
  20 *
  21 * This program is free software: you can redistribute it and/or modify
  22 * it under the terms of the GNU General Public License as published by
  23 * the Free Software Foundation, either version 3 of the License, or
  24 * (at your option) any later version.
  25 *
  26 * This program is distributed in the hope that it will be useful,
  27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29 * GNU General Public License for more details.
  30 *
  31 * You should have received a copy of the GNU General Public License
  32 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  33 *
  34 *
  35 *****************************************************************************/
  36
  37 const char *progname = "check_ntp_time";
  38 const char *copyright = "2006-2008";
  39 const char *email = "devel@monitoring-plugins.org";
  40
  41 #include "common.h"
  42 #include "netutils.h"
  43 #include "utils.h"
  44
  45 static char *server_address=NULL;
  46 static char *port="123";
  47 static int verbose=0;
  48 static int quiet=0;
  49 static char *owarn="60";
  50 static char *ocrit="120";
  51 static int time_offset=0;
  52
  53 int process_arguments (int, char **);
  54 thresholds *offset_thresholds = NULL;
  55 void print_help (void);
  56 void print_usage (void);
  57
  58 /* number of times to perform each request to get a good average. */
  59 #ifndef AVG_NUM
  60 #define AVG_NUM 4
  61 #endif
  62
  63 /* max size of control message data */
  64 #define MAX_CM_SIZE 468
  65
  66 /* this structure holds everything in an ntp request/response as per rfc1305 */
  67 typedef struct {
  68         uint8_t flags;       /* byte with leapindicator,vers,mode. see macros */
  69         uint8_t stratum;     /* clock stratum */
  70         int8_t poll;         /* polling interval */
  71         int8_t precision;    /* precision of the local clock */
  72         int32_t rtdelay;     /* total rt delay, as a fixed point num. see macros */
  73         uint32_t rtdisp;     /* like above, but for max err to primary src */
  74         uint32_t refid;      /* ref clock identifier */
  75         uint64_t refts;      /* reference timestamp.  local time local clock */
  76         uint64_t origts;     /* time at which request departed client */
  77         uint64_t rxts;       /* time at which request arrived at server */
  78         uint64_t txts;       /* time at which request departed server */
  79 } ntp_message;
  80
  81 /* this structure holds data about results from querying offset from a peer */
  82 typedef struct {
  83         time_t waiting;         /* ts set when we started waiting for a response */
  84         int num_responses;      /* number of successfully recieved responses */
  85         uint8_t stratum;        /* copied verbatim from the ntp_message */
  86         double rtdelay;         /* converted from the ntp_message */
  87         double rtdisp;          /* converted from the ntp_message */
  88         double offset[AVG_NUM]; /* offsets from each response */
  89         uint8_t flags;       /* byte with leapindicator,vers,mode. see macros */
  90 } ntp_server_results;
  91
  92 /* bits 1,2 are the leap indicator */
  93 #define LI_MASK 0xc0
  94 #define LI(x) ((x&LI_MASK)>>6)
  95 #define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
  96 /* and these are the values of the leap indicator */
  97 #define LI_NOWARNING 0x00
  98 #define LI_EXTRASEC 0x01
  99 #define LI_MISSINGSEC 0x02
 100 #define LI_ALARM 0x03
 101 /* bits 3,4,5 are the ntp version */
 102 #define VN_MASK 0x38
 103 #define VN(x)   ((x&VN_MASK)>>3)
 104 #define VN_SET(x,y)     do{ x |= ((y<<3)&VN_MASK); }while(0)
 105 #define VN_RESERVED 0x02
 106 /* bits 6,7,8 are the ntp mode */
 107 #define MODE_MASK 0x07
 108 #define MODE(x) (x&MODE_MASK)
 109 #define MODE_SET(x,y)   do{ x |= (y&MODE_MASK); }while(0)
 110 /* here are some values */
 111 #define MODE_CLIENT 0x03
 112 #define MODE_CONTROLMSG 0x06
 113 /* In control message, bits 8-10 are R,E,M bits */
 114 #define REM_MASK 0xe0
 115 #define REM_RESP 0x80
 116 #define REM_ERROR 0x40
 117 #define REM_MORE 0x20
 118 /* In control message, bits 11 - 15 are opcode */
 119 #define OP_MASK 0x1f
 120 #define OP_SET(x,y)   do{ x |= (y&OP_MASK); }while(0)
 121 #define OP_READSTAT 0x01
 122 #define OP_READVAR  0x02
 123 /* In peer status bytes, bits 6,7,8 determine clock selection status */
 124 #define PEER_SEL(x) ((ntohs(x)>>8)&0x07)
 125 #define PEER_INCLUDED 0x04
 126 #define PEER_SYNCSOURCE 0x06
 127
 128 /**
 129  ** a note about the 32-bit "fixed point" numbers:
 130  **
 131  they are divided into halves, each being a 16-bit int in network byte order:
 132  - the first 16 bits are an int on the left side of a decimal point.
 133  - the second 16 bits represent a fraction n/(2^16)
 134  likewise for the 64-bit "fixed point" numbers with everything doubled :)
 135  **/
 136
 137 /* macros to access the left/right 16 bits of a 32-bit ntp "fixed point"
 138    number.  note that these can be used as lvalues too */
 139 #define L16(x) (((uint16_t*)&x)[0])
 140 #define R16(x) (((uint16_t*)&x)[1])
 141 /* macros to access the left/right 32 bits of a 64-bit ntp "fixed point"
 142    number.  these too can be used as lvalues */
 143 #define L32(x) (((uint32_t*)&x)[0])
 144 #define R32(x) (((uint32_t*)&x)[1])
 145
 146 /* ntp wants seconds since 1/1/00, epoch is 1/1/70.  this is the difference */
 147 #define EPOCHDIFF 0x83aa7e80UL
 148
 149 /* extract a 32-bit ntp fixed point number into a double */
 150 #define NTP32asDOUBLE(x) (ntohs(L16(x)) + (double)ntohs(R16(x))/65536.0)
 151
 152 /* likewise for a 64-bit ntp fp number */
 153 #define NTP64asDOUBLE(n) (double)(((uint64_t)n)?\
 154                          (ntohl(L32(n))-EPOCHDIFF) + \
 155                          (.00000001*(0.5+(double)(ntohl(R32(n))/42.94967296))):\
 156                          0)
 157
 158 /* convert a struct timeval to a double */
 159 #define TVasDOUBLE(x) (double)(x.tv_sec+(0.000001*x.tv_usec))
 160
 161 /* convert an ntp 64-bit fp number to a struct timeval */
 162 #define NTP64toTV(n,t) \
 163         do{ if(!n) t.tv_sec = t.tv_usec = 0; \
 164             else { \
 165                         t.tv_sec=ntohl(L32(n))-EPOCHDIFF; \
 166                         t.tv_usec=(int)(0.5+(double)(ntohl(R32(n))/4294.967296)); \
 167                 } \
 168         }while(0)
 169
 170 /* convert a struct timeval to an ntp 64-bit fp number */
 171 #define TVtoNTP64(t,n) \
 172         do{ if(!t.tv_usec && !t.tv_sec) n=0x0UL; \
 173                 else { \
 174                         L32(n)=htonl(t.tv_sec + EPOCHDIFF); \
 175                         R32(n)=htonl((uint64_t)((4294.967296*t.tv_usec)+.5)); \
 176                 } \
 177         } while(0)
 178
 179 /* NTP control message header is 12 bytes, plus any data in the data
 180  * field, plus null padding to the nearest 32-bit boundary per rfc.
 181  */
 182 #define SIZEOF_NTPCM(m) (12+ntohs(m.count)+((m.count)?4-(ntohs(m.count)%4):0))
 183
 184 /* finally, a little helper or two for debugging: */
 185 #define DBG(x) do{if(verbose>1){ x; }}while(0);
 186 #define PRINTSOCKADDR(x) \
 187         do{ \
 188                 printf("%u.%u.%u.%u", (x>>24)&0xff, (x>>16)&0xff, (x>>8)&0xff, x&0xff);\
 189         }while(0);
 190
 191 /* calculate the offset of the local clock */
 192 static inline double calc_offset(const ntp_message *m, const struct timeval *t){
 193         double client_tx, peer_rx, peer_tx, client_rx;
 194         client_tx = NTP64asDOUBLE(m->origts);
 195         peer_rx = NTP64asDOUBLE(m->rxts);
 196         peer_tx = NTP64asDOUBLE(m->txts);
 197         client_rx=TVasDOUBLE((*t));
 198         return (.5*((peer_tx-client_rx)+(peer_rx-client_tx)));
 199 }
 200
 201 /* print out a ntp packet in human readable/debuggable format */
 202 void print_ntp_message(const ntp_message *p){
 203         struct timeval ref, orig, rx, tx;
 204
 205         NTP64toTV(p->refts,ref);
 206         NTP64toTV(p->origts,orig);
 207         NTP64toTV(p->rxts,rx);
 208         NTP64toTV(p->txts,tx);
 209
 210         printf("packet contents:\n");
 211         printf("\tflags: 0x%.2x\n", p->flags);
 212         printf("\t  li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
 213         printf("\t  vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
 214         printf("\t  mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
 215         printf("\tstratum = %d\n", p->stratum);
 216         printf("\tpoll = %g\n", pow(2, p->poll));
 217         printf("\tprecision = %g\n", pow(2, p->precision));
 218         printf("\trtdelay = %-.16g\n", NTP32asDOUBLE(p->rtdelay));
 219         printf("\trtdisp = %-.16g\n", NTP32asDOUBLE(p->rtdisp));
 220         printf("\trefid = %x\n", p->refid);
 221         printf("\trefts = %-.16g\n", NTP64asDOUBLE(p->refts));
 222         printf("\torigts = %-.16g\n", NTP64asDOUBLE(p->origts));
 223         printf("\trxts = %-.16g\n", NTP64asDOUBLE(p->rxts));
 224         printf("\ttxts = %-.16g\n", NTP64asDOUBLE(p->txts));
 225 }
 226
 227 void setup_request(ntp_message *p){
 228         struct timeval t;
 229
 230         memset(p, 0, sizeof(ntp_message));
 231         LI_SET(p->flags, LI_ALARM);
 232         VN_SET(p->flags, 4);
 233         MODE_SET(p->flags, MODE_CLIENT);
 234         p->poll=4;
 235         p->precision=(int8_t)0xfa;
 236         L16(p->rtdelay)=htons(1);
 237         L16(p->rtdisp)=htons(1);
 238
 239         gettimeofday(&t, NULL);
 240         TVtoNTP64(t,p->txts);
 241 }
 242
 243 /* select the "best" server from a list of servers, and return its index.
 244  * this is done by filtering servers based on stratum, dispersion, and
 245  * finally round-trip delay. */
 246 int best_offset_server(const ntp_server_results *slist, int nservers){
 247         int cserver=0, best_server=-1;
 248
 249         /* for each server */
 250         for(cserver=0; cserver<nservers; cserver++){
 251                 /* We don't want any servers that fails these tests */
 252                 /* Sort out servers that didn't respond or responede with a 0 stratum;
 253                  * stratum 0 is for reference clocks so no NTP server should ever report
 254                  * a stratum 0 */
 255                 if ( slist[cserver].stratum == 0){
 256                         if (verbose) printf("discarding peer %d: stratum=%d\n", cserver, slist[cserver].stratum);
 257                         continue;
 258                 }
 259                 /* Sort out servers with error flags */
 260                 if ( LI(slist[cserver].flags) == LI_ALARM ){
 261                         if (verbose) printf("discarding peer %d: flags=%d\n", cserver, LI(slist[cserver].flags));
 262                         continue;
 263                 }
 264
 265                 /* If we don't have a server yet, use the first one */
 266                 if (best_server == -1) {
 267                         best_server = cserver;
 268                         DBG(printf("using peer %d as our first candidate\n", best_server));
 269                         continue;
 270                 }
 271
 272                 /* compare the server to the best one we've seen so far */
 273                 /* does it have an equal or better stratum? */
 274                 DBG(printf("comparing peer %d with peer %d\n", cserver, best_server));
 275                 if(slist[cserver].stratum <= slist[best_server].stratum){
 276                         DBG(printf("stratum for peer %d <= peer %d\n", cserver, best_server));
 277                         /* does it have an equal or better dispersion? */
 278                         if(slist[cserver].rtdisp <= slist[best_server].rtdisp){
 279                                 DBG(printf("dispersion for peer %d <= peer %d\n", cserver, best_server));
 280                                 /* does it have a better rtdelay? */
 281                                 if(slist[cserver].rtdelay < slist[best_server].rtdelay){
 282                                         DBG(printf("rtdelay for peer %d < peer %d\n", cserver, best_server));
 283                                         best_server = cserver;
 284                                         DBG(printf("peer %d is now our best candidate\n", best_server));
 285                                 }
 286                         }
 287                 }
 288         }
 289
 290         if(best_server >= 0) {
 291                 DBG(printf("best server selected: peer %d\n", best_server));
 292                 return best_server;
 293         } else {
 294                 DBG(printf("no peers meeting synchronization criteria :(\n"));
 295                 return -1;
 296         }
 297 }
 298
 299 /* do everything we need to get the total average offset
 300  * - we use a certain amount of parallelization with poll() to ensure
 301  *   we don't waste time sitting around waiting for single packets.
 302  * - we also "manually" handle resolving host names and connecting, because
 303  *   we have to do it in a way that our lazy macros don't handle currently :( */
 304 double offset_request(const char *host, int *status){
 305         int i=0, j=0, ga_result=0, num_hosts=0, *socklist=NULL, respnum=0;
 306         int servers_completed=0, one_read=0, servers_readable=0, best_index=-1;
 307         time_t now_time=0, start_ts=0;
 308         ntp_message *req=NULL;
 309         double avg_offset=0.;
 310         struct timeval recv_time;
 311         struct addrinfo *ai=NULL, *ai_tmp=NULL, hints;
 312         struct pollfd *ufds=NULL;
 313         ntp_server_results *servers=NULL;
 314
 315         /* setup hints to only return results from getaddrinfo that we'd like */
 316         memset(&hints, 0, sizeof(struct addrinfo));
 317         hints.ai_family = address_family;
 318         hints.ai_protocol = IPPROTO_UDP;
 319         hints.ai_socktype = SOCK_DGRAM;
 320
 321         /* fill in ai with the list of hosts resolved by the host name */
 322         ga_result = getaddrinfo(host, port, &hints, &ai);
 323         if(ga_result!=0){
 324                 die(STATE_UNKNOWN, "error getting address for %s: %s\n",
 325                     host, gai_strerror(ga_result));
 326         }
 327
 328         /* count the number of returned hosts, and allocate stuff accordingly */
 329         for(ai_tmp=ai; ai_tmp!=NULL; ai_tmp=ai_tmp->ai_next){ num_hosts++; }
 330         req=(ntp_message*)malloc(sizeof(ntp_message)*num_hosts);
 331         if(req==NULL) die(STATE_UNKNOWN, "can not allocate ntp message array");
 332         socklist=(int*)malloc(sizeof(int)*num_hosts);
 333         if(socklist==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
 334         ufds=(struct pollfd*)malloc(sizeof(struct pollfd)*num_hosts);
 335         if(ufds==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
 336         servers=(ntp_server_results*)malloc(sizeof(ntp_server_results)*num_hosts);
 337         if(servers==NULL) die(STATE_UNKNOWN, "can not allocate server array");
 338         memset(servers, 0, sizeof(ntp_server_results)*num_hosts);
 339         DBG(printf("Found %d peers to check\n", num_hosts));
 340
 341         /* setup each socket for writing, and the corresponding struct pollfd */
 342         ai_tmp=ai;
 343         for(i=0;ai_tmp;i++){
 344                 socklist[i]=socket(ai_tmp->ai_family, SOCK_DGRAM, IPPROTO_UDP);
 345                 if(socklist[i] == -1) {
 346                         perror(NULL);
 347                         die(STATE_UNKNOWN, "can not create new socket");
 348                 }
 349                 if(connect(socklist[i], ai_tmp->ai_addr, ai_tmp->ai_addrlen)){
 350                         /* don't die here, because it is enough if there is one server
 351                            answering in time. This also would break for dual ipv4/6 stacked
 352                            ntp servers when the client only supports on of them.
 353                          */
 354                         DBG(printf("can't create socket connection on peer %i: %s\n", i, strerror(errno)));
 355                 } else {
 356                         ufds[i].fd=socklist[i];
 357                         ufds[i].events=POLLIN;
 358                         ufds[i].revents=0;
 359                 }
 360                 ai_tmp = ai_tmp->ai_next;
 361         }
 362
 363         /* now do AVG_NUM checks to each host. We stop before timeout/2 seconds
 364          * have passed in order to ensure post-processing and jitter time. */
 365         now_time=start_ts=time(NULL);
 366         while(servers_completed<num_hosts && now_time-start_ts <= socket_timeout/2){
 367                 /* loop through each server and find each one which hasn't
 368                  * been touched in the past second or so and is still lacking
 369                  * some responses. For each of these servers, send a new request,
 370                  * and update the "waiting" timestamp with the current time. */
 371                 now_time=time(NULL);
 372
 373                 for(i=0; i<num_hosts; i++){
 374                         if(servers[i].waiting<now_time && servers[i].num_responses<AVG_NUM){
 375                                 if(verbose && servers[i].waiting != 0) printf("re-");
 376                                 if(verbose) printf("sending request to peer %d\n", i);
 377                                 setup_request(&req[i]);
 378                                 write(socklist[i], &req[i], sizeof(ntp_message));
 379                                 servers[i].waiting=now_time;
 380                                 break;
 381                         }
 382                 }
 383
 384                 /* quickly poll for any sockets with pending data */
 385                 servers_readable=poll(ufds, num_hosts, 100);
 386                 if(servers_readable==-1){
 387                         perror("polling ntp sockets");
 388                         die(STATE_UNKNOWN, "communication errors");
 389                 }
 390
 391                 /* read from any sockets with pending data */
 392                 for(i=0; servers_readable && i<num_hosts; i++){
 393                         if(ufds[i].revents&POLLIN && servers[i].num_responses < AVG_NUM){
 394                                 if(verbose) {
 395                                         printf("response from peer %d: ", i);
 396                                 }
 397
 398                                 read(ufds[i].fd, &req[i], sizeof(ntp_message));
 399                                 gettimeofday(&recv_time, NULL);
 400                                 DBG(print_ntp_message(&req[i]));
 401                                 respnum=servers[i].num_responses++;
 402                                 servers[i].offset[respnum]=calc_offset(&req[i], &recv_time)+time_offset;
 403                                 if(verbose) {
 404                                         printf("offset %.10g\n", servers[i].offset[respnum]);
 405                                 }
 406                                 servers[i].stratum=req[i].stratum;
 407                                 servers[i].rtdisp=NTP32asDOUBLE(req[i].rtdisp);
 408                                 servers[i].rtdelay=NTP32asDOUBLE(req[i].rtdelay);
 409                                 servers[i].waiting=0;
 410                                 servers[i].flags=req[i].flags;
 411                                 servers_readable--;
 412                                 one_read = 1;
 413                                 if(servers[i].num_responses==AVG_NUM) servers_completed++;
 414                         }
 415                 }
 416                 /* lather, rinse, repeat. */
 417         }
 418
 419         if (one_read == 0) {
 420                 die(STATE_CRITICAL, "NTP CRITICAL: No response from NTP server\n");
 421         }
 422
 423         /* now, pick the best server from the list */
 424         best_index=best_offset_server(servers, num_hosts);
 425         if(best_index < 0){
 426                 *status=STATE_UNKNOWN;
 427         } else {
 428                 /* finally, calculate the average offset */
 429                 for(i=0; i<servers[best_index].num_responses;i++){
 430                         avg_offset+=servers[best_index].offset[i];
 431                 }
 432                 avg_offset/=servers[best_index].num_responses;
 433         }
 434
 435         /* cleanup */
 436         for(j=0; j<num_hosts; j++){ close(socklist[j]); }
 437         free(socklist);
 438         free(ufds);
 439         free(servers);
 440         free(req);
 441         freeaddrinfo(ai);
 442
 443         if(verbose) printf("overall average offset: %.10g\n", avg_offset);
 444         return avg_offset;
 445 }
 446
 447 int process_arguments(int argc, char **argv){
 448         int c;
 449         int option=0;
 450         static struct option longopts[] = {
 451                 {"version", no_argument, 0, 'V'},
 452                 {"help", no_argument, 0, 'h'},
 453                 {"verbose", no_argument, 0, 'v'},
 454                 {"use-ipv4", no_argument, 0, '4'},
 455                 {"use-ipv6", no_argument, 0, '6'},
 456                 {"quiet", no_argument, 0, 'q'},
 457                 {"time-offset", optional_argument, 0, 'o'},
 458                 {"warning", required_argument, 0, 'w'},
 459                 {"critical", required_argument, 0, 'c'},
 460                 {"timeout", required_argument, 0, 't'},
 461                 {"hostname", required_argument, 0, 'H'},
 462                 {"port", required_argument, 0, 'p'},
 463                 {0, 0, 0, 0}
 464         };
 465
 466
 467         if (argc < 2)
 468                 usage ("\n");
 469
 470         while (1) {
 471                 c = getopt_long (argc, argv, "Vhv46qw:c:t:H:p:o:", longopts, &option);
 472                 if (c == -1 || c == EOF || c == 1)
 473                         break;
 474
 475                 switch (c) {
 476                 case 'h':
 477                         print_help();
 478                         exit(STATE_UNKNOWN);
 479                         break;
 480                 case 'V':
 481                         print_revision(progname, NP_VERSION);
 482                         exit(STATE_UNKNOWN);
 483                         break;
 484                 case 'v':
 485                         verbose++;
 486                         break;
 487                 case 'q':
 488                         quiet = 1;
 489                         break;
 490                 case 'w':
 491                         owarn = optarg;
 492                         break;
 493                 case 'c':
 494                         ocrit = optarg;
 495                         break;
 496                 case 'H':
 497                         if(is_host(optarg) == FALSE)
 498                                 usage2(_("Invalid hostname/address"), optarg);
 499                         server_address = strdup(optarg);
 500                         break;
 501                 case 'p':
 502                         port = strdup(optarg);
 503                         break;
 504                 case 't':
 505                         socket_timeout=atoi(optarg);
 506                         break;
 507                 case 'o':
 508                         time_offset=atoi(optarg);
 509                         break;
 510                 case '4':
 511                         address_family = AF_INET;
 512                         break;
 513                 case '6':
 514 #ifdef USE_IPV6
 515                         address_family = AF_INET6;
 516 #else
 517                         usage4 (_("IPv6 support not available"));
 518 #endif
 519                         break;
 520                 case '?':
 521                         /* print short usage statement if args not parsable */
 522                         usage5 ();
 523                         break;
 524                 }
 525         }
 526
 527         if(server_address == NULL){
 528                 usage4(_("Hostname was not supplied"));
 529         }
 530
 531         return 0;
 532 }
 533
 534 char *perfd_offset (double offset)
 535 {
 536         return fperfdata ("offset", offset, "s",
 537                 TRUE, offset_thresholds->warning->end,
 538                 TRUE, offset_thresholds->critical->end,
 539                 FALSE, 0, FALSE, 0);
 540 }
 541
 542 int main(int argc, char *argv[]){
 543         int result, offset_result;
 544         double offset=0;
 545         char *result_line, *perfdata_line;
 546
 547         setlocale (LC_ALL, "");
 548         bindtextdomain (PACKAGE, LOCALEDIR);
 549         textdomain (PACKAGE);
 550
 551         result = offset_result = STATE_OK;
 552
 553         /* Parse extra opts if any */
 554         argv=np_extra_opts (&argc, argv, progname);
 555
 556         if (process_arguments (argc, argv) == ERROR)
 557                 usage4 (_("Could not parse arguments"));
 558
 559         set_thresholds(&offset_thresholds, owarn, ocrit);
 560
 561         /* initialize alarm signal handling */
 562         signal (SIGALRM, socket_timeout_alarm_handler);
 563
 564         /* set socket timeout */
 565         alarm (socket_timeout);
 566
 567         offset = offset_request(server_address, &offset_result);
 568         if (offset_result == STATE_UNKNOWN) {
 569                 result = (quiet == 1 ? STATE_UNKNOWN : STATE_CRITICAL);
 570         } else {
 571                 result = get_status(fabs(offset), offset_thresholds);
 572         }
 573
 574         switch (result) {
 575                 case STATE_CRITICAL :
 576                         xasprintf(&result_line, _("NTP CRITICAL:"));
 577                         break;
 578                 case STATE_WARNING :
 579                         xasprintf(&result_line, _("NTP WARNING:"));
 580                         break;
 581                 case STATE_OK :
 582                         xasprintf(&result_line, _("NTP OK:"));
 583                         break;
 584                 default :
 585                         xasprintf(&result_line, _("NTP UNKNOWN:"));
 586                         break;
 587         }
 588         if(offset_result == STATE_UNKNOWN){
 589                 xasprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
 590                 xasprintf(&perfdata_line, "");
 591         } else {
 592                 xasprintf(&result_line, "%s %s %.10g secs", result_line, _("Offset"), offset);
 593                 xasprintf(&perfdata_line, "%s", perfd_offset(offset));
 594         }
 595         printf("%s|%s\n", result_line, perfdata_line);
 596
 597         if(server_address!=NULL) free(server_address);
 598         return result;
 599 }
 600
 601 void print_help(void){
 602         print_revision(progname, NP_VERSION);
 603
 604         printf ("Copyright (c) 2006 Sean Finney\n");
 605         printf (COPYRIGHT, copyright, email);
 606
 607         printf ("%s\n", _("This plugin checks the clock offset with the ntp server"));
 608
 609         printf ("\n\n");
 610
 611         print_usage();
 612         printf (UT_HELP_VRSN);
 613         printf (UT_EXTRA_OPTS);
 614         printf (UT_IPv46);
 615         printf (UT_HOST_PORT, 'p', "123");
 616         printf (" %s\n", "-q, --quiet");
 617         printf ("    %s\n", _("Returns UNKNOWN instead of CRITICAL if offset cannot be found"));
 618         printf (" %s\n", "-w, --warning=THRESHOLD");
 619         printf ("    %s\n", _("Offset to result in warning status (seconds)"));
 620         printf (" %s\n", "-c, --critical=THRESHOLD");
 621         printf ("    %s\n", _("Offset to result in critical status (seconds)"));
 622         printf (" %s\n", "-o, --time_offset=INTEGER");
 623         printf ("    %s\n", _("Expected offset of the ntp server relative to local server (seconds)"));
 624         printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
 625         printf (UT_VERBOSE);
 626
 627         printf("\n");
 628         printf("%s\n", _("This plugin checks the clock offset between the local host and a"));
 629         printf("%s\n", _("remote NTP server. It is independent of any commandline programs or"));
 630         printf("%s\n", _("external libraries."));
 631
 632         printf("\n");
 633         printf("%s\n", _("Notes:"));
 634         printf(" %s\n", _("If you'd rather want to monitor an NTP server, please use"));
 635         printf(" %s\n", _("check_ntp_peer."));
 636         printf(" %s\n", _("--time-offset is useful for compensating for servers with known"));
 637         printf(" %s\n", _("and expected clock skew."));
 638         printf("\n");
 639         printf(UT_THRESHOLDS_NOTES);
 640
 641         printf("\n");
 642         printf("%s\n", _("Examples:"));
 643         printf("  %s\n", ("./check_ntp_time -H ntpserv -w 0.5 -c 1"));
 644
 645         printf (UT_SUPPORT);
 646 }
 647
 648 void
 649 print_usage(void)
 650 {
 651         printf ("%s\n", _("Usage:"));
 652         printf(" %s -H <host> [-4|-6] [-w <warn>] [-c <crit>] [-v verbose] [-o <time offset>]\n", progname);
 653 }
 654