/*****************************************************************************
*
* Monitoring check_smtp plugin
*
* License: GPL
* Copyright (c) 2000-2007 Monitoring Plugins Development Team
*
* Description:
*
* This file contains the check_smtp plugin
*
* This plugin will attempt to open an SMTP connection with the host.
*
*
* 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 .
*
*
*****************************************************************************/
const char *progname = "check_smtp";
const char *copyright = "2000-2007";
const char *email = "devel@monitoring-plugins.org";
#include "common.h"
#include "netutils.h"
#include "utils.h"
#include "base64.h"
#include
#ifdef HAVE_SSL
int check_cert = FALSE;
int days_till_exp_warn, days_till_exp_crit;
# define my_recv(buf, len) ((use_ssl && ssl_established) ? np_net_ssl_read(buf, len) : read(sd, buf, len))
# define my_send(buf, len) ((use_ssl && ssl_established) ? np_net_ssl_write(buf, len) : send(sd, buf, len, 0))
#else /* ifndef HAVE_SSL */
# define my_recv(buf, len) read(sd, buf, len)
# define my_send(buf, len) send(sd, buf, len, 0)
#endif
enum {
SMTP_PORT = 25
};
#define SMTP_EXPECT "220"
#define SMTP_HELO "HELO "
#define SMTP_EHLO "EHLO "
#define SMTP_QUIT "QUIT\r\n"
#define SMTP_STARTTLS "STARTTLS\r\n"
#define SMTP_AUTH_LOGIN "AUTH LOGIN\r\n"
#ifndef HOST_MAX_BYTES
#define HOST_MAX_BYTES 255
#endif
#define EHLO_SUPPORTS_STARTTLS 1
int process_arguments (int, char **);
int validate_arguments (void);
void print_help (void);
void print_usage (void);
void smtp_quit(void);
int recvline(char *, size_t);
int recvlines(char *, size_t);
int my_close(void);
#include "regex.h"
char regex_expect[MAX_INPUT_BUFFER] = "";
regex_t preg;
regmatch_t pmatch[10];
char timestamp[20] = "";
char errbuf[MAX_INPUT_BUFFER];
int cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
int eflags = 0;
int errcode, excode;
int server_port = SMTP_PORT;
char *server_address = NULL;
char *server_expect = NULL;
char *mail_command = NULL;
char *from_arg = NULL;
int send_mail_from=0;
int ncommands=0;
int command_size=0;
int nresponses=0;
int response_size=0;
char **commands = NULL;
char **responses = NULL;
char *authtype = NULL;
char *authuser = NULL;
char *authpass = NULL;
double warning_time = 0;
int check_warning_time = FALSE;
double critical_time = 0;
int check_critical_time = FALSE;
int verbose = 0;
int use_ssl = FALSE;
short use_ehlo = FALSE;
short ssl_established = 0;
char *localhostname = NULL;
int sd;
char buffer[MAX_INPUT_BUFFER];
enum {
TCP_PROTOCOL = 1,
UDP_PROTOCOL = 2,
};
int ignore_send_quit_failure = FALSE;
int
main (int argc, char **argv)
{
short supports_tls=FALSE;
int n = 0;
double elapsed_time;
long microsec;
int result = STATE_UNKNOWN;
char *cmd_str = NULL;
char *helocmd = NULL;
char *error_msg = "";
struct timeval tv;
/* Catch pipe errors in read/write - sometimes occurs when writing QUIT */
(void) signal (SIGPIPE, SIG_IGN);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
/* Parse extra opts if any */
argv=np_extra_opts (&argc, argv, progname);
if (process_arguments (argc, argv) == ERROR)
usage4 (_("Could not parse arguments"));
/* If localhostname not set on command line, use gethostname to set */
if(! localhostname){
localhostname = malloc (HOST_MAX_BYTES);
if(!localhostname){
printf(_("malloc() failed!\n"));
return STATE_CRITICAL;
}
if(gethostname(localhostname, HOST_MAX_BYTES)){
printf(_("gethostname() failed!\n"));
return STATE_CRITICAL;
}
}
if(use_ehlo)
xasprintf (&helocmd, "%s%s%s", SMTP_EHLO, localhostname, "\r\n");
else
xasprintf (&helocmd, "%s%s%s", SMTP_HELO, localhostname, "\r\n");
if (verbose)
printf("HELOCMD: %s", helocmd);
/* initialize the MAIL command with optional FROM command */
xasprintf (&cmd_str, "%sFROM:<%s>%s", mail_command, from_arg, "\r\n");
if (verbose && send_mail_from)
printf ("FROM CMD: %s", cmd_str);
/* initialize alarm signal handling */
(void) signal (SIGALRM, socket_timeout_alarm_handler);
/* set socket timeout */
(void) alarm (socket_timeout);
/* start timer */
gettimeofday (&tv, NULL);
/* try to connect to the host at the given port number */
result = my_tcp_connect (server_address, server_port, &sd);
if (result == STATE_OK) { /* we connected */
/* watch for the SMTP connection string and */
/* return a WARNING status if we couldn't read any data */
if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
printf (_("recv() failed\n"));
return STATE_WARNING;
}
else {
if (verbose)
printf ("%s", buffer);
/* strip the buffer of carriage returns */
strip (buffer);
/* make sure we find the response we are looking for */
if (!strstr (buffer, server_expect)) {
if (server_port == SMTP_PORT)
printf (_("Invalid SMTP response received from host: %s\n"), buffer);
else
printf (_("Invalid SMTP response received from host on port %d: %s\n"),
server_port, buffer);
return STATE_WARNING;
}
}
/* send the HELO/EHLO command */
send(sd, helocmd, strlen(helocmd), 0);
/* allow for response to helo command to reach us */
if (recvlines(buffer, MAX_INPUT_BUFFER) <= 0) {
printf (_("recv() failed\n"));
return STATE_WARNING;
} else if(use_ehlo){
if(strstr(buffer, "250 STARTTLS") != NULL ||
strstr(buffer, "250-STARTTLS") != NULL){
supports_tls=TRUE;
}
}
if(use_ssl && ! supports_tls){
printf(_("WARNING - TLS not supported by server\n"));
smtp_quit();
return STATE_WARNING;
}
#ifdef HAVE_SSL
if(use_ssl) {
/* send the STARTTLS command */
send(sd, SMTP_STARTTLS, strlen(SMTP_STARTTLS), 0);
recvlines(buffer, MAX_INPUT_BUFFER); /* wait for it */
if (!strstr (buffer, SMTP_EXPECT)) {
printf (_("Server does not support STARTTLS\n"));
smtp_quit();
return STATE_UNKNOWN;
}
result = np_net_ssl_init(sd);
if(result != STATE_OK) {
printf (_("CRITICAL - Cannot create SSL context.\n"));
np_net_ssl_cleanup();
close(sd);
return STATE_CRITICAL;
} else {
ssl_established = 1;
}
/*
* Resend the EHLO command.
*
* RFC 3207 (4.2) says: ``The client MUST discard any knowledge
* obtained from the server, such as the list of SMTP service
* extensions, which was not obtained from the TLS negotiation
* itself. The client SHOULD send an EHLO command as the first
* command after a successful TLS negotiation.'' For this
* reason, some MTAs will not allow an AUTH LOGIN command before
* we resent EHLO via TLS.
*/
if (my_send(helocmd, strlen(helocmd)) <= 0) {
printf("%s\n", _("SMTP UNKNOWN - Cannot send EHLO command via TLS."));
my_close();
return STATE_UNKNOWN;
}
if (verbose)
printf(_("sent %s"), helocmd);
if ((n = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
printf("%s\n", _("SMTP UNKNOWN - Cannot read EHLO response via TLS."));
my_close();
return STATE_UNKNOWN;
}
if (verbose) {
printf("%s", buffer);
}
# ifdef USE_OPENSSL
if ( check_cert ) {
result = np_net_ssl_check_cert(days_till_exp_warn, days_till_exp_crit);
smtp_quit();
my_close();
return result;
}
# endif /* USE_OPENSSL */
}
#endif
if (send_mail_from) {
my_send(cmd_str, strlen(cmd_str));
if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
printf("%s", buffer);
}
while (n < ncommands) {
xasprintf (&cmd_str, "%s%s", commands[n], "\r\n");
my_send(cmd_str, strlen(cmd_str));
if (recvlines(buffer, MAX_INPUT_BUFFER) >= 1 && verbose)
printf("%s", buffer);
strip (buffer);
if (n < nresponses) {
cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
errcode = regcomp (&preg, responses[n], cflags);
if (errcode != 0) {
regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);
printf (_("Could Not Compile Regular Expression"));
return ERROR;
}
excode = regexec (&preg, buffer, 10, pmatch, eflags);
if (excode == 0) {
result = STATE_OK;
}
else if (excode == REG_NOMATCH) {
result = STATE_WARNING;
printf (_("SMTP %s - Invalid response '%s' to command '%s'\n"), state_text (result), buffer, commands[n]);
}
else {
regerror (excode, &preg, errbuf, MAX_INPUT_BUFFER);
printf (_("Execute Error: %s\n"), errbuf);
result = STATE_UNKNOWN;
}
}
n++;
}
if (authtype != NULL) {
if (strcmp (authtype, "LOGIN") == 0) {
char *abuf;
int ret;
do {
if (authuser == NULL) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("no authuser specified, "));
break;
}
if (authpass == NULL) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("no authpass specified, "));
break;
}
/* send AUTH LOGIN */
my_send(SMTP_AUTH_LOGIN, strlen(SMTP_AUTH_LOGIN));
if (verbose)
printf (_("sent %s\n"), "AUTH LOGIN");
if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
xasprintf(&error_msg, _("recv() failed after AUTH LOGIN, "));
result = STATE_WARNING;
break;
}
if (verbose)
printf (_("received %s\n"), buffer);
if (strncmp (buffer, "334", 3) != 0) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("invalid response received after AUTH LOGIN, "));
break;
}
/* encode authuser with base64 */
base64_encode_alloc (authuser, strlen(authuser), &abuf);
xasprintf(&abuf, "%s\r\n", abuf);
my_send(abuf, strlen(abuf));
if (verbose)
printf (_("sent %s\n"), abuf);
if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("recv() failed after sending authuser, "));
break;
}
if (verbose) {
printf (_("received %s\n"), buffer);
}
if (strncmp (buffer, "334", 3) != 0) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("invalid response received after authuser, "));
break;
}
/* encode authpass with base64 */
base64_encode_alloc (authpass, strlen(authpass), &abuf);
xasprintf(&abuf, "%s\r\n", abuf);
my_send(abuf, strlen(abuf));
if (verbose) {
printf (_("sent %s\n"), abuf);
}
if ((ret = recvlines(buffer, MAX_INPUT_BUFFER)) <= 0) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("recv() failed after sending authpass, "));
break;
}
if (verbose) {
printf (_("received %s\n"), buffer);
}
if (strncmp (buffer, "235", 3) != 0) {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("invalid response received after authpass, "));
break;
}
break;
} while (0);
} else {
result = STATE_CRITICAL;
xasprintf(&error_msg, _("only authtype LOGIN is supported, "));
}
}
/* tell the server we're done */
smtp_quit();
/* finally close the connection */
close (sd);
}
/* reset the alarm */
alarm (0);
microsec = deltime (tv);
elapsed_time = (double)microsec / 1.0e6;
if (result == STATE_OK) {
if (check_critical_time && elapsed_time > critical_time)
result = STATE_CRITICAL;
else if (check_warning_time && elapsed_time > warning_time)
result = STATE_WARNING;
}
printf (_("SMTP %s - %s%.3f sec. response time%s%s|%s\n"),
state_text (result),
error_msg,
elapsed_time,
verbose?", ":"", verbose?buffer:"",
fperfdata ("time", elapsed_time, "s",
(int)check_warning_time, warning_time,
(int)check_critical_time, critical_time,
TRUE, 0, FALSE, 0));
return result;
}
/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
int c;
char* temp;
int option = 0;
static struct option longopts[] = {
{"hostname", required_argument, 0, 'H'},
{"expect", required_argument, 0, 'e'},
{"critical", required_argument, 0, 'c'},
{"warning", required_argument, 0, 'w'},
{"timeout", required_argument, 0, 't'},
{"port", required_argument, 0, 'p'},
{"from", required_argument, 0, 'f'},
{"fqdn", required_argument, 0, 'F'},
{"authtype", required_argument, 0, 'A'},
{"authuser", required_argument, 0, 'U'},
{"authpass", required_argument, 0, 'P'},
{"command", required_argument, 0, 'C'},
{"response", required_argument, 0, 'R'},
{"verbose", no_argument, 0, 'v'},
{"version", no_argument, 0, 'V'},
{"use-ipv4", no_argument, 0, '4'},
{"use-ipv6", no_argument, 0, '6'},
{"help", no_argument, 0, 'h'},
{"starttls",no_argument,0,'S'},
{"certificate",required_argument,0,'D'},
{"ignore-quit-failure",no_argument,0,'q'},
{0, 0, 0, 0}
};
if (argc < 2)
return ERROR;
for (c = 1; c < argc; c++) {
if (strcmp ("-to", argv[c]) == 0)
strcpy (argv[c], "-t");
else if (strcmp ("-wt", argv[c]) == 0)
strcpy (argv[c], "-w");
else if (strcmp ("-ct", argv[c]) == 0)
strcpy (argv[c], "-c");
}
while (1) {
c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:R:SD:F:A:U:P:q",
longopts, &option);
if (c == -1 || c == EOF)
break;
switch (c) {
case 'H': /* hostname */
if (is_host (optarg)) {
server_address = optarg;
}
else {
usage2 (_("Invalid hostname/address"), optarg);
}
break;
case 'p': /* port */
if (is_intpos (optarg))
server_port = atoi (optarg);
else
usage4 (_("Port must be a positive integer"));
break;
case 'F':
/* localhostname */
localhostname = strdup(optarg);
break;
case 'f': /* from argument */
from_arg = optarg + strspn(optarg, "<");
from_arg = strndup(from_arg, strcspn(from_arg, ">"));
send_mail_from = 1;
break;
case 'A':
authtype = optarg;
use_ehlo = TRUE;
break;
case 'U':
authuser = optarg;
break;
case 'P':
authpass = optarg;
break;
case 'e': /* server expect string on 220 */
server_expect = optarg;
break;
case 'C': /* commands */
if (ncommands >= command_size) {
command_size+=8;
commands = realloc (commands, sizeof(char *) * command_size);
if (commands == NULL)
die (STATE_UNKNOWN,
_("Could not realloc() units [%d]\n"), ncommands);
}
commands[ncommands] = (char *) malloc (sizeof(char) * 255);
strncpy (commands[ncommands], optarg, 255);
ncommands++;
break;
case 'R': /* server responses */
if (nresponses >= response_size) {
response_size += 8;
responses = realloc (responses, sizeof(char *) * response_size);
if (responses == NULL)
die (STATE_UNKNOWN,
_("Could not realloc() units [%d]\n"), nresponses);
}
responses[nresponses] = (char *) malloc (sizeof(char) * 255);
strncpy (responses[nresponses], optarg, 255);
nresponses++;
break;
case 'c': /* critical time threshold */
if (!is_nonnegative (optarg))
usage4 (_("Critical time must be a positive"));
else {
critical_time = strtod (optarg, NULL);
check_critical_time = TRUE;
}
break;
case 'w': /* warning time threshold */
if (!is_nonnegative (optarg))
usage4 (_("Warning time must be a positive"));
else {
warning_time = strtod (optarg, NULL);
check_warning_time = TRUE;
}
break;
case 'v': /* verbose */
verbose++;
break;
case 'q':
ignore_send_quit_failure++; /* ignore problem sending QUIT */
break;
case 't': /* timeout */
if (is_intnonneg (optarg)) {
socket_timeout = atoi (optarg);
}
else {
usage4 (_("Timeout interval must be a positive integer"));
}
break;
case 'D':
/* Check SSL cert validity */
#ifdef USE_OPENSSL
if ((temp=strchr(optarg,','))!=NULL) {
*temp='\0';
if (!is_intnonneg (optarg))
usage2 ("Invalid certificate expiration period", optarg);
days_till_exp_warn = atoi(optarg);
*temp=',';
temp++;
if (!is_intnonneg (temp))
usage2 (_("Invalid certificate expiration period"), temp);
days_till_exp_crit = atoi (temp);
}
else {
days_till_exp_crit=0;
if (!is_intnonneg (optarg))
usage2 ("Invalid certificate expiration period", optarg);
days_till_exp_warn = atoi (optarg);
}
check_cert = TRUE;
ignore_send_quit_failure = TRUE;
#else
usage (_("SSL support not available - install OpenSSL and recompile"));
#endif
case 'S':
/* starttls */
use_ssl = TRUE;
use_ehlo = TRUE;
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 'V': /* version */
print_revision (progname, NP_VERSION);
exit (STATE_UNKNOWN);
case 'h': /* help */
print_help ();
exit (STATE_UNKNOWN);
case '?': /* help */
usage5 ();
}
}
c = optind;
if (server_address == NULL) {
if (argv[c]) {
if (is_host (argv[c]))
server_address = argv[c];
else
usage2 (_("Invalid hostname/address"), argv[c]);
}
else {
xasprintf (&server_address, "127.0.0.1");
}
}
if (server_expect == NULL)
server_expect = strdup (SMTP_EXPECT);
if (mail_command == NULL)
mail_command = strdup("MAIL ");
if (from_arg==NULL)
from_arg = strdup(" ");
return validate_arguments ();
}
int
validate_arguments (void)
{
return OK;
}
void
smtp_quit(void)
{
int bytes;
int n;
n = my_send(SMTP_QUIT, strlen(SMTP_QUIT));
if(n < 0) {
if(ignore_send_quit_failure) {
if(verbose) {
printf(_("Connection closed by server before sending QUIT command\n"));
}
return;
}
die (STATE_UNKNOWN,
_("Connection closed by server before sending QUIT command\n"));
}
if (verbose)
printf(_("sent %s\n"), "QUIT");
/* read the response but don't care about problems */
bytes = recvlines(buffer, MAX_INPUT_BUFFER);
if (verbose) {
if (bytes < 0)
printf(_("recv() failed after QUIT."));
else if (bytes == 0)
printf(_("Connection reset by peer."));
else {
buffer[bytes] = '\0';
printf(_("received %s\n"), buffer);
}
}
}
/*
* Receive one line, copy it into buf and nul-terminate it. Returns the
* number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
* error.
*
* TODO: Reading one byte at a time is very inefficient. Replace this by a
* function which buffers the data, move that to netutils.c and change
* check_smtp and other plugins to use that. Also, remove (\r)\n.
*/
int
recvline(char *buf, size_t bufsize)
{
int result;
unsigned i;
for (i = result = 0; i < bufsize - 1; i++) {
if ((result = my_recv(&buf[i], 1)) != 1)
break;
if (buf[i] == '\n') {
buf[++i] = '\0';
return i;
}
}
return (result == 1 || i == 0) ? -2 : result; /* -2 if out of space */
}
/*
* Receive one or more lines, copy them into buf and nul-terminate it. Returns
* the number of bytes written to buf (excluding the '\0') or 0 on EOF or <0 on
* error. Works for all protocols which format multiline replies as follows:
*
* ``The format for multiline replies requires that every line, except the last,
* begin with the reply code, followed immediately by a hyphen, `-' (also known
* as minus), followed by text. The last line will begin with the reply code,
* followed immediately by , optionally some text, and . As noted
* above, servers SHOULD send the if subsequent text is not sent, but
* clients MUST be prepared for it to be omitted.'' (RFC 2821, 4.2.1)
*
* TODO: Move this to netutils.c. Also, remove \r and possibly the final \n.
*/
int
recvlines(char *buf, size_t bufsize)
{
int result, i;
for (i = 0; /* forever */; i += result)
if (!((result = recvline(buf + i, bufsize - i)) > 3 &&
isdigit((int)buf[i]) &&
isdigit((int)buf[i + 1]) &&
isdigit((int)buf[i + 2]) &&
buf[i + 3] == '-'))
break;
return (result <= 0) ? result : result + i;
}
int
my_close (void)
{
#ifdef HAVE_SSL
np_net_ssl_cleanup();
#endif
return close(sd);
}
void
print_help (void)
{
char *myport;
xasprintf (&myport, "%d", SMTP_PORT);
print_revision (progname, NP_VERSION);
printf ("Copyright (c) 1999-2001 Ethan Galstad \n");
printf (COPYRIGHT, copyright, email);
printf("%s\n", _("This plugin will attempt to open an SMTP connection with the host."));
printf ("\n\n");
print_usage ();
printf (UT_HELP_VRSN);
printf (UT_EXTRA_OPTS);
printf (UT_HOST_PORT, 'p', myport);
printf (UT_IPv46);
printf (" %s\n", "-e, --expect=STRING");
printf (_(" String to expect in first line of server response (default: '%s')\n"), SMTP_EXPECT);
printf (" %s\n", "-C, --command=STRING");
printf (" %s\n", _("SMTP command (may be used repeatedly)"));
printf (" %s\n", "-R, --response=STRING");
printf (" %s\n", _("Expected response to command (may be used repeatedly)"));
printf (" %s\n", "-f, --from=STRING");
printf (" %s\n", _("FROM-address to include in MAIL command, required by Exchange 2000")),
printf (" %s\n", "-F, --fqdn=STRING");
printf (" %s\n", _("FQDN used for HELO"));
#ifdef HAVE_SSL
printf (" %s\n", "-D, --certificate=INTEGER[,INTEGER]");
printf (" %s\n", _("Minimum number of days a certificate has to be valid."));
printf (" %s\n", "-S, --starttls");
printf (" %s\n", _("Use STARTTLS for the connection."));
#endif
printf (" %s\n", "-A, --authtype=STRING");
printf (" %s\n", _("SMTP AUTH type to check (default none, only LOGIN supported)"));
printf (" %s\n", "-U, --authuser=STRING");
printf (" %s\n", _("SMTP AUTH username"));
printf (" %s\n", "-P, --authpass=STRING");
printf (" %s\n", _("SMTP AUTH password"));
printf (" %s\n", "-q, --ignore-quit-failure");
printf (" %s\n", _("Ignore failure when sending QUIT command to server"));
printf (UT_WARN_CRIT);
printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
printf (UT_VERBOSE);
printf("\n");
printf ("%s\n", _("Successul connects return STATE_OK, refusals and timeouts return"));
printf ("%s\n", _("STATE_CRITICAL, other errors return STATE_UNKNOWN. Successful"));
printf ("%s\n", _("connects, but incorrect reponse messages from the host result in"));
printf ("%s\n", _("STATE_WARNING return values."));
printf (UT_SUPPORT);
}
void
print_usage (void)
{
printf ("%s\n", _("Usage:"));
printf ("%s -H host [-p port] [-4|-6] [-e expect] [-C command] [-R response] [-f from addr]\n", progname);
printf ("[-A authtype -U authuser -P authpass] [-w warn] [-c crit] [-t timeout] [-q]\n");
printf ("[-F fqdn] [-S] [-D warn days cert expire[,crit days cert expire]] [-v] \n");
}