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monitoring-plugins/plugins/check_ntp.c
Lorenz Kästle 802e46f8ea Run clang-format again
2025-09-15 12:59:37 +02:00

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/*****************************************************************************
*
* Monitoring check_ntp plugin
*
* License: GPL
* Copyright (c) 2006 Sean Finney <seanius@seanius.net>
* Copyright (c) 2006-2024 Monitoring Plugins Development Team
*
* Description:
*
* This file contains the check_ntp plugin
*
* This plugin to check ntp servers independent of any commandline
* programs or external libraries.
*
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*
*****************************************************************************/
const char *progname = "check_ntp";
const char *copyright = "2006-2024";
const char *email = "devel@monitoring-plugins.org";
#include "common.h"
#include "netutils.h"
#include "utils.h"
static char *server_address = NULL;
static int verbose = 0;
static bool do_offset = false;
static char *owarn = "60";
static char *ocrit = "120";
static bool do_jitter = false;
static char *jwarn = "5000";
static char *jcrit = "10000";
static int process_arguments(int /*argc*/, char ** /*argv*/);
static thresholds *offset_thresholds = NULL;
static thresholds *jitter_thresholds = NULL;
static void print_help(void);
void print_usage(void);
/* number of times to perform each request to get a good average. */
#ifndef AVG_NUM
# define AVG_NUM 4
#endif
/* 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 received 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;
/* this structure holds everything in an ntp control message as per rfc1305 */
typedef struct {
uint8_t flags; /* byte with leapindicator,vers,mode. see macros */
uint8_t op; /* R,E,M bits and Opcode */
uint16_t seq; /* Packet sequence */
uint16_t status; /* Clock status */
uint16_t assoc; /* Association */
uint16_t offset; /* Similar to TCP sequence # */
uint16_t count; /* # bytes of data */
char data[MAX_CM_SIZE]; /* ASCII data of the request */
/* NB: not necessarily NULL terminated! */
} ntp_control_message;
/* this is an association/status-word pair found in control packet responses */
typedef struct {
uint16_t assoc;
uint16_t status;
} ntp_assoc_status_pair;
/* 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) + ((ntohs(m.count) % 4) ? 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 print_ntp_control_message(const ntp_control_message *p) {
int i = 0, numpeers = 0;
const ntp_assoc_status_pair *peer = NULL;
printf("control packet contents:\n");
printf("\tflags: 0x%.2x , 0x%.2x\n", p->flags, p->op);
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("\t response=%d (0x%.2x)\n", (p->op & REM_RESP) > 0, p->op & REM_RESP);
printf("\t more=%d (0x%.2x)\n", (p->op & REM_MORE) > 0, p->op & REM_MORE);
printf("\t error=%d (0x%.2x)\n", (p->op & REM_ERROR) > 0, p->op & REM_ERROR);
printf("\t op=%d (0x%.2x)\n", p->op & OP_MASK, p->op & OP_MASK);
printf("\tsequence: %d (0x%.2x)\n", ntohs(p->seq), ntohs(p->seq));
printf("\tstatus: %d (0x%.2x)\n", ntohs(p->status), ntohs(p->status));
printf("\tassoc: %d (0x%.2x)\n", ntohs(p->assoc), ntohs(p->assoc));
printf("\toffset: %d (0x%.2x)\n", ntohs(p->offset), ntohs(p->offset));
printf("\tcount: %d (0x%.2x)\n", ntohs(p->count), ntohs(p->count));
numpeers = ntohs(p->count) / (sizeof(ntp_assoc_status_pair));
if (p->op & REM_RESP && p->op & OP_READSTAT) {
peer = (ntp_assoc_status_pair *)p->data;
for (i = 0; i < numpeers; i++) {
printf("\tpeer id %.2x status %.2x", ntohs(peer[i].assoc), ntohs(peer[i].status));
if (PEER_SEL(peer[i].status) >= PEER_INCLUDED) {
if (PEER_SEL(peer[i].status) >= PEER_SYNCSOURCE) {
printf(" <-- current sync source");
} else {
printf(" <-- current sync candidate");
}
}
printf("\n");
}
}
}
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 cserver = 0, best_server = -1;
/* for each server */
for (cserver = 0; cserver < nservers; cserver++) {
/* We don't want any servers that fails these tests */
/* Sort out servers that didn't respond or responede with a 0 stratum;
* stratum 0 is for reference clocks so no NTP server should ever report
* a stratum 0 */
if (slist[cserver].stratum == 0) {
if (verbose) {
printf("discarding peer %d: stratum=%d\n", cserver, slist[cserver].stratum);
}
continue;
}
/* Sort out servers with error flags */
if (LI(slist[cserver].flags) == LI_ALARM) {
if (verbose) {
printf("discarding peer %d: flags=%d\n", cserver, LI(slist[cserver].flags));
}
continue;
}
/* If we don't have a server yet, use the first one */
if (best_server == -1) {
best_server = cserver;
DBG(printf("using peer %d as our first candidate\n", best_server));
continue;
}
/* compare the server to the best one we've seen so far */
/* does it have an equal or better stratum? */
DBG(printf("comparing peer %d with peer %d\n", cserver, best_server));
if (slist[cserver].stratum <= slist[best_server].stratum) {
DBG(printf("stratum for peer %d <= peer %d\n", cserver, best_server));
/* does it have an equal or better dispersion? */
if (slist[cserver].rtdisp <= slist[best_server].rtdisp) {
DBG(printf("dispersion for peer %d <= peer %d\n", cserver, best_server));
/* does it have a better rtdelay? */
if (slist[cserver].rtdelay < slist[best_server].rtdelay) {
DBG(printf("rtdelay for peer %d < peer %d\n", cserver, best_server));
best_server = cserver;
DBG(printf("peer %d is now our best candidate\n", best_server));
}
}
}
}
if (best_server >= 0) {
DBG(printf("best server selected: peer %d\n", best_server));
return best_server;
} 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, ga_result = 0, num_hosts = 0, *socklist = NULL, respnum = 0;
int servers_completed = 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);
DBG(printf("Found %d peers to check\n", 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)) {
/* don't die here, because it is enough if there is one server
answering in time. This also would break for dual ipv4/6 stacked
ntp servers when the client only supports on of them.
*/
DBG(printf("can't create socket connection on peer %i: %s\n", i, strerror(errno)));
} 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. */
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;
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[i];
}
avg_offset /= servers[best_index].num_responses;
}
/* cleanup */
/* FIXME: Not closing the socket to avoid reuse of the local port
* which can cause old NTP packets to be read instead of NTP control
* packets in jitter_request(). THERE MUST BE ANOTHER WAY...
* 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;
}
void setup_control_request(ntp_control_message *p, uint8_t opcode, uint16_t seq) {
memset(p, 0, sizeof(ntp_control_message));
LI_SET(p->flags, LI_NOWARNING);
VN_SET(p->flags, VN_RESERVED);
MODE_SET(p->flags, MODE_CONTROLMSG);
OP_SET(p->op, opcode);
p->seq = htons(seq);
/* Remaining fields are zero for requests */
}
/* XXX handle responses with the error bit set */
double jitter_request(int *status) {
int conn = -1, i, npeers = 0, num_candidates = 0;
bool syncsource_found = false;
int run = 0, min_peer_sel = PEER_INCLUDED, num_selected = 0, num_valid = 0;
int peers_size = 0, peer_offset = 0;
ntp_assoc_status_pair *peers = NULL;
ntp_control_message req;
const char *getvar = "jitter";
double rval = 0.0, jitter = -1.0;
char *startofvalue = NULL, *nptr = NULL;
void *tmp;
/* Long-winded explanation:
* Getting the jitter requires a number of steps:
* 1) Send a READSTAT request.
* 2) Interpret the READSTAT reply
* a) The data section contains a list of peer identifiers (16 bits)
* and associated status words (16 bits)
* b) We want the value of 0x06 in the SEL (peer selection) value,
* which means "current synchronizatin source". If that's missing,
* we take anything better than 0x04 (see the rfc for details) but
* set a minimum of warning.
* 3) Send a READVAR request for information on each peer identified
* in 2b greater than the minimum selection value.
* 4) Extract the jitter value from the data[] (it's ASCII)
*/
my_udp_connect(server_address, 123, &conn);
/* keep sending requests until the server stops setting the
* REM_MORE bit, though usually this is only 1 packet. */
do {
setup_control_request(&req, OP_READSTAT, 1);
DBG(printf("sending READSTAT request"));
write(conn, &req, SIZEOF_NTPCM(req));
DBG(print_ntp_control_message(&req));
/* Attempt to read the largest size packet possible */
req.count = htons(MAX_CM_SIZE);
DBG(printf("receiving READSTAT response"))
read(conn, &req, SIZEOF_NTPCM(req));
DBG(print_ntp_control_message(&req));
/* Each peer identifier is 4 bytes in the data section, which
* we represent as a ntp_assoc_status_pair datatype.
*/
peers_size += ntohs(req.count);
if ((tmp = realloc(peers, peers_size)) == NULL) {
free(peers), die(STATE_UNKNOWN, "can not (re)allocate 'peers' buffer\n");
}
peers = tmp;
memcpy((void *)((ptrdiff_t)peers + peer_offset), (void *)req.data, ntohs(req.count));
npeers = peers_size / sizeof(ntp_assoc_status_pair);
peer_offset += ntohs(req.count);
} while (req.op & REM_MORE);
/* first, let's find out if we have a sync source, or if there are
* at least some candidates. in the case of the latter we'll issue
* a warning but go ahead with the check on them. */
for (i = 0; i < npeers; i++) {
if (PEER_SEL(peers[i].status) >= PEER_INCLUDED) {
num_candidates++;
if (PEER_SEL(peers[i].status) >= PEER_SYNCSOURCE) {
syncsource_found = true;
min_peer_sel = PEER_SYNCSOURCE;
}
}
}
if (verbose) {
printf("%d candidate peers available\n", num_candidates);
}
if (verbose && syncsource_found) {
printf("synchronization source found\n");
}
if (!syncsource_found) {
*status = STATE_UNKNOWN;
if (verbose) {
printf("warning: no synchronization source found\n");
}
}
for (run = 0; run < AVG_NUM; run++) {
if (verbose) {
printf("jitter run %d of %d\n", run + 1, AVG_NUM);
}
for (i = 0; i < npeers; i++) {
/* Only query this server if it is the current sync source */
if (PEER_SEL(peers[i].status) >= min_peer_sel) {
char jitter_data[MAX_CM_SIZE + 1];
size_t jitter_data_count;
num_selected++;
setup_control_request(&req, OP_READVAR, 2);
req.assoc = peers[i].assoc;
/* By spec, putting the variable name "jitter" in the request
* should cause the server to provide _only_ the jitter value.
* thus reducing net traffic, guaranteeing us only a single
* datagram in reply, and making interpretation much simpler
*/
/* Older servers doesn't know what jitter is, so if we get an
* error on the first pass we redo it with "dispersion" */
strncpy(req.data, getvar, MAX_CM_SIZE - 1);
req.count = htons(strlen(getvar));
DBG(printf("sending READVAR request...\n"));
write(conn, &req, SIZEOF_NTPCM(req));
DBG(print_ntp_control_message(&req));
req.count = htons(MAX_CM_SIZE);
DBG(printf("receiving READVAR response...\n"));
read(conn, &req, SIZEOF_NTPCM(req));
DBG(print_ntp_control_message(&req));
if (req.op & REM_ERROR && strstr(getvar, "jitter")) {
if (verbose) {
printf("The 'jitter' command failed (old ntp server?)\nRestarting with "
"'dispersion'...\n");
}
getvar = "dispersion";
num_selected--;
i--;
continue;
}
/* get to the float value */
if (verbose) {
printf("parsing jitter from peer %.2x: ", ntohs(peers[i].assoc));
}
if ((jitter_data_count = ntohs(req.count)) >= sizeof(jitter_data)) {
die(STATE_UNKNOWN, _("jitter response too large (%lu bytes)\n"),
(unsigned long)jitter_data_count);
}
memcpy(jitter_data, req.data, jitter_data_count);
jitter_data[jitter_data_count] = '\0';
startofvalue = strchr(jitter_data, '=');
if (startofvalue != NULL) {
startofvalue++;
jitter = strtod(startofvalue, &nptr);
}
if (startofvalue == NULL || startofvalue == nptr) {
printf("warning: unable to read server jitter response.\n");
*status = STATE_UNKNOWN;
} else {
if (verbose) {
printf("%g\n", jitter);
}
num_valid++;
rval += jitter;
}
}
}
if (verbose) {
printf("jitter parsed from %d/%d peers\n", num_valid, num_selected);
}
}
rval = num_valid ? rval / num_valid : -1.0;
close(conn);
if (peers != NULL) {
free(peers);
}
/* If we return -1.0, it means no synchronization source was found */
return rval;
}
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'}, {"warning", required_argument, 0, 'w'},
{"critical", required_argument, 0, 'c'}, {"jwarn", required_argument, 0, 'j'},
{"jcrit", required_argument, 0, 'k'}, {"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, "Vhv46w:c:j:k:t:H:", longopts, &option);
if (c == -1 || c == EOF || c == 1) {
break;
}
switch (c) {
case 'h':
print_help();
exit(STATE_UNKNOWN);
break;
case 'V':
print_revision(progname, NP_VERSION);
exit(STATE_UNKNOWN);
break;
case 'v':
verbose++;
break;
case 'w':
do_offset = true;
owarn = optarg;
break;
case 'c':
do_offset = true;
ocrit = optarg;
break;
case 'j':
do_jitter = true;
jwarn = optarg;
break;
case 'k':
do_jitter = true;
jcrit = optarg;
break;
case 'H':
if (!is_host(optarg)) {
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);
}
char *perfd_jitter(double jitter) {
return fperfdata("jitter", jitter, "s", do_jitter, jitter_thresholds->warning->end, do_jitter,
jitter_thresholds->critical->end, true, 0, false, 0);
}
int main(int argc, char *argv[]) {
int result, offset_result, jitter_result;
double offset = 0, jitter = 0;
char *result_line, *perfdata_line;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
result = offset_result = jitter_result = STATE_OK;
/* Parse extra opts if any */
argv = np_extra_opts(&argc, argv, progname);
if (process_arguments(argc, argv) == ERROR) {
usage4(_("Could not parse arguments"));
}
set_thresholds(&offset_thresholds, owarn, ocrit);
set_thresholds(&jitter_thresholds, jwarn, jcrit);
/* initialize alarm signal handling */
signal(SIGALRM, socket_timeout_alarm_handler);
/* set socket timeout */
alarm(socket_timeout);
offset = offset_request(server_address, &offset_result);
/* check_ntp used to always return CRITICAL if offset_result == STATE_UNKNOWN.
* Now we'll only do that is the offset thresholds were set */
if (do_offset && offset_result == STATE_UNKNOWN) {
result = STATE_CRITICAL;
} else {
result = get_status(fabs(offset), offset_thresholds);
}
/* If not told to check the jitter, we don't even send packets.
* jitter is checked using NTP control packets, which not all
* servers recognize. Trying to check the jitter on OpenNTPD
* (for example) will result in an error
*/
if (do_jitter) {
jitter = jitter_request(&jitter_result);
result = max_state_alt(result, get_status(jitter, jitter_thresholds));
/* -1 indicates that we couldn't calculate the jitter
* Only overrides STATE_OK from the offset */
if (jitter == -1.0 && result == STATE_OK) {
result = STATE_UNKNOWN;
}
}
result = max_state_alt(result, jitter_result);
switch (result) {
case STATE_CRITICAL:
xasprintf(&result_line, _("NTP CRITICAL:"));
break;
case STATE_WARNING:
xasprintf(&result_line, _("NTP WARNING:"));
break;
case STATE_OK:
xasprintf(&result_line, _("NTP OK:"));
break;
default:
xasprintf(&result_line, _("NTP UNKNOWN:"));
break;
}
if (offset_result == STATE_UNKNOWN) {
xasprintf(&result_line, "%s %s", result_line, _("Offset unknown"));
xasprintf(&perfdata_line, "");
} else {
xasprintf(&result_line, "%s %s %.10g secs", result_line, _("Offset"), offset);
xasprintf(&perfdata_line, "%s", perfd_offset(offset));
}
if (do_jitter) {
xasprintf(&result_line, "%s, jitter=%f", result_line, jitter);
xasprintf(&perfdata_line, "%s %s", perfdata_line, perfd_jitter(jitter));
}
printf("%s|%s\n", result_line, perfdata_line);
if (server_address != NULL) {
free(server_address);
}
return result;
}
void print_help(void) {
print_revision(progname, NP_VERSION);
printf("Copyright (c) 2006 Sean Finney\n");
printf(COPYRIGHT, copyright, email);
printf("%s\n", _("This plugin checks the selected ntp server"));
printf("\n\n");
print_usage();
printf(UT_HELP_VRSN);
printf(UT_EXTRA_OPTS);
printf(UT_HOST_PORT, 'p', "123");
printf(UT_IPv46);
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(" %s\n", "-j, --jwarn=THRESHOLD");
printf(" %s\n", _("Warning threshold for jitter"));
printf(" %s\n", "-k, --jcrit=THRESHOLD");
printf(" %s\n", _("Critical threshold for jitter"));
printf(UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
printf(UT_VERBOSE);
printf("\n");
printf("%s\n", _("Notes:"));
printf(UT_THRESHOLDS_NOTES);
printf("\n");
printf("%s\n", _("Examples:"));
printf(" %s\n", _("Normal offset check:"));
printf(" %s\n", ("./check_ntp -H ntpserv -w 0.5 -c 1"));
printf("\n");
printf(" %s\n",
_("Check jitter too, avoiding critical notifications if jitter isn't available"));
printf(" %s\n", _("(See Notes above for more details on thresholds formats):"));
printf(" %s\n", ("./check_ntp -H ntpserv -w 0.5 -c 1 -j -1:100 -k -1:200"));
printf(UT_SUPPORT);
printf("%s\n", _("WARNING: check_ntp is deprecated. Please use check_ntp_peer or"));
printf("%s\n\n", _("check_ntp_time instead."));
}
void print_usage(void) {
printf("%s\n", _("WARNING: check_ntp is deprecated. Please use check_ntp_peer or"));
printf("%s\n\n", _("check_ntp_time instead."));
printf("%s\n", _("Usage:"));
printf(" %s -H <host> [-w <warn>] [-c <crit>] [-j <warn>] [-k <crit>] [-4|-6] [-v verbose]\n",
progname);
}
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