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pkg-monitoring-plugins/plugins/check_ntp_time.c

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Imported Upstream version 1.4.11
2013-11-26 22:54:57 +00:00
/******************************************************************************
*
* Nagios check_ntp_time plugin
*
* License: GPL
* Copyright (c) 2006 sean finney <seanius@seanius.net>
* Copyright (c) 2007 nagios-plugins team
*
* Last Modified: $Date: 2007-12-11 05:57:35 +0000 (Tue, 11 Dec 2007) $
*
* Description:
*
* This file contains the check_ntp_time plugin
*
* This plugin checks the clock offset between the local host and a
* remote NTP server. It is independent of any commandline programs or
* external libraries.
*
* If you'd rather want to monitor an NTP server, please use
* check_ntp_peer.
*
*
* License Information:
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: check_ntp_time.c 1861 2007-12-11 05:57:35Z dermoth $
*****************************************************************************/
const char *progname = "check_ntp_time";
const char *revision = "$Revision: 1861 $";
const char *copyright = "2007";
const char *email = "nagiosplug-devel@lists.sourceforge.net";
#include "common.h"
#include "netutils.h"
#include "utils.h"
static char *server_address=NULL;
static int verbose=0;
static int quiet=0;
static char *owarn="60";
static char *ocrit="120";
int process_arguments (int, char **);
thresholds *offset_thresholds = NULL;
void print_help (void);
void print_usage (void);
/* number of times to perform each request to get a good average. */
#define AVG_NUM 4
/* max size of control message data */
#define MAX_CM_SIZE 468
/* this structure holds everything in an ntp request/response as per rfc1305 */
typedef struct {
uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
uint8_t stratum; /* clock stratum */
int8_t poll; /* polling interval */
int8_t precision; /* precision of the local clock */
int32_t rtdelay; /* total rt delay, as a fixed point num. see macros */
uint32_t rtdisp; /* like above, but for max err to primary src */
uint32_t refid; /* ref clock identifier */
uint64_t refts; /* reference timestamp. local time local clock */
uint64_t origts; /* time at which request departed client */
uint64_t rxts; /* time at which request arrived at server */
uint64_t txts; /* time at which request departed server */
} ntp_message;
/* this structure holds data about results from querying offset from a peer */
typedef struct {
time_t waiting; /* ts set when we started waiting for a response */
int num_responses; /* number of successfully recieved responses */
uint8_t stratum; /* copied verbatim from the ntp_message */
double rtdelay; /* converted from the ntp_message */
double rtdisp; /* converted from the ntp_message */
double offset[AVG_NUM]; /* offsets from each response */
uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
} ntp_server_results;
/* bits 1,2 are the leap indicator */
#define LI_MASK 0xc0
#define LI(x) ((x&LI_MASK)>>6)
#define LI_SET(x,y) do{ x |= ((y<<6)&LI_MASK); }while(0)
/* and these are the values of the leap indicator */
#define LI_NOWARNING 0x00
#define LI_EXTRASEC 0x01
#define LI_MISSINGSEC 0x02
#define LI_ALARM 0x03
/* bits 3,4,5 are the ntp version */
#define VN_MASK 0x38
#define VN(x) ((x&VN_MASK)>>3)
#define VN_SET(x,y) do{ x |= ((y<<3)&VN_MASK); }while(0)
#define VN_RESERVED 0x02
/* bits 6,7,8 are the ntp mode */
#define MODE_MASK 0x07
#define MODE(x) (x&MODE_MASK)
#define MODE_SET(x,y) do{ x |= (y&MODE_MASK); }while(0)
/* here are some values */
#define MODE_CLIENT 0x03
#define MODE_CONTROLMSG 0x06
/* In control message, bits 8-10 are R,E,M bits */
#define REM_MASK 0xe0
#define REM_RESP 0x80
#define REM_ERROR 0x40
#define REM_MORE 0x20
/* In control message, bits 11 - 15 are opcode */
#define OP_MASK 0x1f
#define OP_SET(x,y) do{ x |= (y&OP_MASK); }while(0)
#define OP_READSTAT 0x01
#define OP_READVAR 0x02
/* In peer status bytes, bits 6,7,8 determine clock selection status */
#define PEER_SEL(x) ((ntohs(x)>>8)&0x07)
#define PEER_INCLUDED 0x04
#define PEER_SYNCSOURCE 0x06
/**
** a note about the 32-bit "fixed point" numbers:
**
they are divided into halves, each being a 16-bit int in network byte order:
- the first 16 bits are an int on the left side of a decimal point.
- the second 16 bits represent a fraction n/(2^16)
likewise for the 64-bit "fixed point" numbers with everything doubled :)
**/
/* macros to access the left/right 16 bits of a 32-bit ntp "fixed point"
number. note that these can be used as lvalues too */
#define L16(x) (((uint16_t*)&x)[0])
#define R16(x) (((uint16_t*)&x)[1])
/* macros to access the left/right 32 bits of a 64-bit ntp "fixed point"
number. these too can be used as lvalues */
#define L32(x) (((uint32_t*)&x)[0])
#define R32(x) (((uint32_t*)&x)[1])
/* ntp wants seconds since 1/1/00, epoch is 1/1/70. this is the difference */
#define EPOCHDIFF 0x83aa7e80UL
/* extract a 32-bit ntp fixed point number into a double */
#define NTP32asDOUBLE(x) (ntohs(L16(x)) + (double)ntohs(R16(x))/65536.0)
/* likewise for a 64-bit ntp fp number */
#define NTP64asDOUBLE(n) (double)(((uint64_t)n)?\
(ntohl(L32(n))-EPOCHDIFF) + \
(.00000001*(0.5+(double)(ntohl(R32(n))/42.94967296))):\
0)
/* convert a struct timeval to a double */
#define TVasDOUBLE(x) (double)(x.tv_sec+(0.000001*x.tv_usec))
/* convert an ntp 64-bit fp number to a struct timeval */
#define NTP64toTV(n,t) \
do{ if(!n) t.tv_sec = t.tv_usec = 0; \
else { \
t.tv_sec=ntohl(L32(n))-EPOCHDIFF; \
t.tv_usec=(int)(0.5+(double)(ntohl(R32(n))/4294.967296)); \
} \
}while(0)
/* convert a struct timeval to an ntp 64-bit fp number */
#define TVtoNTP64(t,n) \
do{ if(!t.tv_usec && !t.tv_sec) n=0x0UL; \
else { \
L32(n)=htonl(t.tv_sec + EPOCHDIFF); \
R32(n)=htonl((uint64_t)((4294.967296*t.tv_usec)+.5)); \
} \
} while(0)
/* NTP control message header is 12 bytes, plus any data in the data
* field, plus null padding to the nearest 32-bit boundary per rfc.
*/
#define SIZEOF_NTPCM(m) (12+ntohs(m.count)+((m.count)?4-(ntohs(m.count)%4):0))
/* finally, a little helper or two for debugging: */
#define DBG(x) do{if(verbose>1){ x; }}while(0);
#define PRINTSOCKADDR(x) \
do{ \
printf("%u.%u.%u.%u", (x>>24)&0xff, (x>>16)&0xff, (x>>8)&0xff, x&0xff);\
}while(0);
/* calculate the offset of the local clock */
static inline double calc_offset(const ntp_message *m, const struct timeval *t){
double client_tx, peer_rx, peer_tx, client_rx;
client_tx = NTP64asDOUBLE(m->origts);
peer_rx = NTP64asDOUBLE(m->rxts);
peer_tx = NTP64asDOUBLE(m->txts);
client_rx=TVasDOUBLE((*t));
return (.5*((peer_tx-client_rx)+(peer_rx-client_tx)));
}
/* print out a ntp packet in human readable/debuggable format */
void print_ntp_message(const ntp_message *p){
struct timeval ref, orig, rx, tx;
NTP64toTV(p->refts,ref);
NTP64toTV(p->origts,orig);
NTP64toTV(p->rxts,rx);
NTP64toTV(p->txts,tx);
printf("packet contents:\n");
printf("\tflags: 0x%.2x\n", p->flags);
printf("\t li=%d (0x%.2x)\n", LI(p->flags), p->flags&LI_MASK);
printf("\t vn=%d (0x%.2x)\n", VN(p->flags), p->flags&VN_MASK);
printf("\t mode=%d (0x%.2x)\n", MODE(p->flags), p->flags&MODE_MASK);
printf("\tstratum = %d\n", p->stratum);
printf("\tpoll = %g\n", pow(2, p->poll));
printf("\tprecision = %g\n", pow(2, p->precision));
printf("\trtdelay = %-.16g\n", NTP32asDOUBLE(p->rtdelay));
printf("\trtdisp = %-.16g\n", NTP32asDOUBLE(p->rtdisp));
printf("\trefid = %x\n", p->refid);
printf("\trefts = %-.16g\n", NTP64asDOUBLE(p->refts));
printf("\torigts = %-.16g\n", NTP64asDOUBLE(p->origts));
printf("\trxts = %-.16g\n", NTP64asDOUBLE(p->rxts));
printf("\ttxts = %-.16g\n", NTP64asDOUBLE(p->txts));
}
void setup_request(ntp_message *p){
struct timeval t;
memset(p, 0, sizeof(ntp_message));
LI_SET(p->flags, LI_ALARM);
VN_SET(p->flags, 4);
MODE_SET(p->flags, MODE_CLIENT);
p->poll=4;
p->precision=(int8_t)0xfa;
L16(p->rtdelay)=htons(1);
L16(p->rtdisp)=htons(1);
gettimeofday(&t, NULL);
TVtoNTP64(t,p->txts);
}
/* select the "best" server from a list of servers, and return its index.
* this is done by filtering servers based on stratum, dispersion, and
* finally round-trip delay. */
int best_offset_server(const ntp_server_results *slist, int nservers){
int i=0, j=0, cserver=0, candidates[5], csize=0;
/* for each server */
for(cserver=0; cserver<nservers; cserver++){
/* sort out servers with error flags */
if ( LI(slist[cserver].flags) != LI_NOWARNING ){
if (verbose) printf("discarding peer id %d: flags=%d\n", cserver, LI(slist[cserver].flags));
break;
}
/* compare it to each of the servers already in the candidate list */
for(i=0; i<csize; i++){
/* does it have an equal or better stratum? */
if(slist[cserver].stratum <= slist[i].stratum){
/* does it have an equal or better dispersion? */
if(slist[cserver].rtdisp <= slist[i].rtdisp){
/* does it have a better rtdelay? */
if(slist[cserver].rtdelay < slist[i].rtdelay){
break;
}
}
}
}
/* if we haven't reached the current list's end, move everyone
* over one to the right, and insert the new candidate */
if(i<csize){
for(j=5; j>i; j--){
candidates[j]=candidates[j-1];
}
}
/* regardless, if they should be on the list... */
if(i<5) {
candidates[i]=cserver;
if(csize<5) csize++;
/* otherwise discard the server */
} else {
DBG(printf("discarding peer id %d\n", cserver));
}
}
if(csize>0) {
DBG(printf("best server selected: peer %d\n", candidates[0]));
return candidates[0];
} else {
DBG(printf("no peers meeting synchronization criteria :(\n"));
return -1;
}
}
/* do everything we need to get the total average offset
* - we use a certain amount of parallelization with poll() to ensure
* we don't waste time sitting around waiting for single packets.
* - we also "manually" handle resolving host names and connecting, because
* we have to do it in a way that our lazy macros don't handle currently :( */
double offset_request(const char *host, int *status){
int i=0, j=0, ga_result=0, num_hosts=0, *socklist=NULL, respnum=0;
int servers_completed=0, one_written=0, one_read=0, servers_readable=0, best_index=-1;
time_t now_time=0, start_ts=0;
ntp_message *req=NULL;
double avg_offset=0.;
struct timeval recv_time;
struct addrinfo *ai=NULL, *ai_tmp=NULL, hints;
struct pollfd *ufds=NULL;
ntp_server_results *servers=NULL;
/* setup hints to only return results from getaddrinfo that we'd like */
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = address_family;
hints.ai_protocol = IPPROTO_UDP;
hints.ai_socktype = SOCK_DGRAM;
/* fill in ai with the list of hosts resolved by the host name */
ga_result = getaddrinfo(host, "123", &hints, &ai);
if(ga_result!=0){
die(STATE_UNKNOWN, "error getting address for %s: %s\n",
host, gai_strerror(ga_result));
}
/* count the number of returned hosts, and allocate stuff accordingly */
for(ai_tmp=ai; ai_tmp!=NULL; ai_tmp=ai_tmp->ai_next){ num_hosts++; }
req=(ntp_message*)malloc(sizeof(ntp_message)*num_hosts);
if(req==NULL) die(STATE_UNKNOWN, "can not allocate ntp message array");
socklist=(int*)malloc(sizeof(int)*num_hosts);
if(socklist==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
ufds=(struct pollfd*)malloc(sizeof(struct pollfd)*num_hosts);
if(ufds==NULL) die(STATE_UNKNOWN, "can not allocate socket array");
servers=(ntp_server_results*)malloc(sizeof(ntp_server_results)*num_hosts);
if(servers==NULL) die(STATE_UNKNOWN, "can not allocate server array");
memset(servers, 0, sizeof(ntp_server_results)*num_hosts);
/* setup each socket for writing, and the corresponding struct pollfd */
ai_tmp=ai;
for(i=0;ai_tmp;i++){
socklist[i]=socket(ai_tmp->ai_family, SOCK_DGRAM, IPPROTO_UDP);
if(socklist[i] == -1) {
perror(NULL);
die(STATE_UNKNOWN, "can not create new socket");
}
if(connect(socklist[i], ai_tmp->ai_addr, ai_tmp->ai_addrlen)){
die(STATE_UNKNOWN, "can't create socket connection");
} else {
ufds[i].fd=socklist[i];
ufds[i].events=POLLIN;
ufds[i].revents=0;
}
ai_tmp = ai_tmp->ai_next;
}
/* now do AVG_NUM checks to each host. We stop before timeout/2 seconds
* have passed in order to ensure post-processing and jitter time. */
now_time=start_ts=time(NULL);
while(servers_completed<num_hosts && now_time-start_ts <= socket_timeout/2){
/* loop through each server and find each one which hasn't
* been touched in the past second or so and is still lacking
* some responses. For each of these servers, send a new request,
* and update the "waiting" timestamp with the current time. */
one_written=0;
now_time=time(NULL);
for(i=0; i<num_hosts; i++){
if(servers[i].waiting<now_time && servers[i].num_responses<AVG_NUM){
if(verbose && servers[i].waiting != 0) printf("re-");
if(verbose) printf("sending request to peer %d\n", i);
setup_request(&req[i]);
write(socklist[i], &req[i], sizeof(ntp_message));
servers[i].waiting=now_time;
one_written=1;
break;
}
}
/* quickly poll for any sockets with pending data */
servers_readable=poll(ufds, num_hosts, 100);
if(servers_readable==-1){
perror("polling ntp sockets");
die(STATE_UNKNOWN, "communication errors");
}
/* read from any sockets with pending data */
for(i=0; servers_readable && i<num_hosts; i++){
if(ufds[i].revents&POLLIN && servers[i].num_responses < AVG_NUM){
if(verbose) {
printf("response from peer %d: ", i);
}
read(ufds[i].fd, &req[i], sizeof(ntp_message));
gettimeofday(&recv_time, NULL);
DBG(print_ntp_message(&req[i]));
respnum=servers[i].num_responses++;
servers[i].offset[respnum]=calc_offset(&req[i], &recv_time);
if(verbose) {
printf("offset %.10g\n", servers[i].offset[respnum]);
}
servers[i].stratum=req[i].stratum;
servers[i].rtdisp=NTP32asDOUBLE(req[i].rtdisp);
servers[i].rtdelay=NTP32asDOUBLE(req[i].rtdelay);
servers[i].waiting=0;
servers[i].flags=req[i].flags;
servers_readable--;
one_read = 1;
if(servers[i].num_responses==AVG_NUM) servers_completed++;
}
}
/* lather, rinse, repeat. */
}
if (one_read == 0) {
die(STATE_CRITICAL, "NTP CRITICAL: No response from NTP server\n");
}
/* now, pick the best server from the list */
best_index=best_offset_server(servers, num_hosts);
if(best_index < 0){
*status=STATE_UNKNOWN;
} else {
/* finally, calculate the average offset */
for(i=0; i<servers[best_index].num_responses;i++){
avg_offset+=servers[best_index].offset[j];
}
avg_offset/=servers[best_index].num_responses;
}
/* cleanup */
for(j=0; j<num_hosts; j++){ close(socklist[j]); }
free(socklist);
free(ufds);
free(servers);
free(req);
freeaddrinfo(ai);
if(verbose) printf("overall average offset: %.10g\n", avg_offset);
return avg_offset;
}
int process_arguments(int argc, char **argv){
int c;
int option=0;
static struct option longopts[] = {
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{"verbose", no_argument, 0, 'v'},
{"use-ipv4", no_argument, 0, '4'},
{"use-ipv6", no_argument, 0, '6'},
{"quiet", no_argument, 0, 'q'},
{"warning", required_argument, 0, 'w'},
{"critical", required_argument, 0, 'c'},
{"timeout", required_argument, 0, 't'},
{"hostname", required_argument, 0, 'H'},
{0, 0, 0, 0}
};
if (argc < 2)
usage ("\n");
while (1) {
c = getopt_long (argc, argv, "Vhv46qw:c:t:H:", longopts, &option);
if (c == -1 || c == EOF || c == 1)
break;
switch (c) {
case 'h':
print_help();
exit(STATE_OK);
break;
case 'V':
print_revision(progname, revision);
exit(STATE_OK);
break;
case 'v':
verbose++;
break;
case 'q':
quiet = 1;
break;
case 'w':
owarn = optarg;
break;
case 'c':
ocrit = optarg;
break;
case 'H':
if(is_host(optarg) == FALSE)
usage2(_("Invalid hostname/address"), optarg);
server_address = strdup(optarg);
break;
case 't':
socket_timeout=atoi(optarg);
break;
case '4':
address_family = AF_INET;
break;
case '6':
#ifdef USE_IPV6
address_family = AF_INET6;
#else
usage4 (_("IPv6 support not available"));
#endif
break;
case '?':
/* print short usage statement if args not parsable */
usage5 ();
break;
}
}
if(server_address == NULL){
usage4(_("Hostname was not supplied"));
}
return 0;
}
char *perfd_offset (double offset)
{
return fperfdata ("offset", offset, "s",
TRUE, offset_thresholds->warning->end,
TRUE, offset_thresholds->critical->end,
FALSE, 0, FALSE, 0);
}
int main(int argc, char *argv[]){
int result, offset_result;
double offset=0;
char *result_line, *perfdata_line;
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
result = offset_result = STATE_OK;
if (process_arguments (argc, argv) == ERROR)
usage4 (_("Could not parse arguments"));
set_thresholds(&offset_thresholds, owarn, ocrit);
/* initialize alarm signal handling */
signal (SIGALRM, socket_timeout_alarm_handler);
/* set socket timeout */
alarm (socket_timeout);
offset = offset_request(server_address, &offset_result);
if (offset_result == STATE_UNKNOWN) {
result = (quiet == 1 ? STATE_UNKNOWN : STATE_CRITICAL);
} else {
result = get_status(fabs(offset), offset_thresholds);
}
switch (result) {
case STATE_CRITICAL :
asprintf(&result_line, _("NTP CRITICAL:"));
break;
case STATE_WARNING :
asprintf(&result_line, _("NTP WARNING:"));
break;
case STATE_OK :
asprintf(&result_line, _("NTP OK:"));
break;
default :
asprintf(&result_line, _("NTP UNKNOWN:"));
break;
}
if(offset_result == STATE_UNKNOWN){
asprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
asprintf(&perfdata_line, "");
} else {
asprintf(&result_line, "%s %s %.10g secs", result_line, _("Offset"), offset);
asprintf(&perfdata_line, "%s", perfd_offset(offset));
}
printf("%s|%s\n", result_line, perfdata_line);
if(server_address!=NULL) free(server_address);
return result;
}
void print_help(void){
print_revision(progname, revision);
printf ("Copyright (c) 2006 Sean Finney\n");
printf (COPYRIGHT, copyright, email);
printf ("%s\n", _("This plugin checks the clock offset with the ntp server"));
printf ("\n\n");
print_usage();
printf (_(UT_HELP_VRSN));
printf (_(UT_HOST_PORT), 'p', "123");
printf (" %s\n", "-q, --quiet");
printf (" %s\n", _("Returns UNKNOWN instead of CRITICAL if offset cannot be found"));
printf (" %s\n", "-w, --warning=THRESHOLD");
printf (" %s\n", _("Offset to result in warning status (seconds)"));
printf (" %s\n", "-c, --critical=THRESHOLD");
printf (" %s\n", _("Offset to result in critical status (seconds)"));
printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
printf (_(UT_VERBOSE));
printf("\n");
printf("%s\n", _("Notes:"));
printf(" %s\n", _("This plugin checks the clock offset between the local host and a"));
printf(" %s\n", _("remote NTP server. It is independent of any commandline programs or"));
printf(" %s\n\n", _("external libraries."));
printf(" %s\n", _("If you'd rather want to monitor an NTP server, please use"));
printf(" %s\n\n", _("check_ntp_peer."));
printf(" %s\n", _("See:"));
printf(" %s\n", ("http://nagiosplug.sourceforge.net/developer-guidelines.html#THRESHOLDFORMAT"));
printf(" %s\n", _("for THRESHOLD format and examples."));
printf("\n");
printf("%s\n", _("Examples:"));
printf(" %s\n", ("./check_ntp_time -H ntpserv -w 0.5 -c 1"));
printf (_(UT_SUPPORT));
}
void
print_usage(void)
{
printf (_("Usage:"));
printf(" %s -H <host> [-w <warn>] [-c <crit>] [-W <warn>] [-C <crit>]\n", progname);
printf(" [-j <warn>] [-k <crit>] [-v verbose]\n");
}
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