debian/pkg-monitoring-plugins
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
pkg-monitoring-plugins/plugins/check_ssh.c

403 lines
10 KiB
C
Raw Blame History

/*****************************************************************************
*
* Monitoring check_ssh plugin
*
* License: GPL
* Copyright (c) 2000-2007 Monitoring Plugins Development Team
*
* Description:
*
* This file contains the check_ssh plugin
*
* Try to connect to an SSH server at specified server and port
*
*
* 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_ssh";
const char *copyright = "2000-2007";
const char *email = "devel@monitoring-plugins.org";
#include "./common.h"
#include "./netutils.h"
#include "utils.h"
#ifndef MSG_DONTWAIT
#define MSG_DONTWAIT 0
#endif
#define SSH_DFL_PORT 22
#define BUFF_SZ 256
int port = -1;
char *server_name = NULL;
char *remote_version = NULL;
char *remote_protocol = NULL;
bool verbose = false;
int process_arguments (int, char **);
int validate_arguments (void);
void print_help (void);
void print_usage (void);
int ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol);
int
main (int argc, char **argv)
{
int result = STATE_UNKNOWN;
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"));
/* initialize alarm signal handling */
signal (SIGALRM, socket_timeout_alarm_handler);
alarm (socket_timeout);
/* ssh_connect exits if error is found */
result = ssh_connect (server_name, port, remote_version, remote_protocol);
alarm (0);
return (result);
}
/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
int c;
int option = 0;
static struct option longopts[] = {
{"help", no_argument, 0, 'h'},
{"version", no_argument, 0, 'V'},
{"host", required_argument, 0, 'H'}, /* backward compatibility */
{"hostname", required_argument, 0, 'H'},
{"port", required_argument, 0, 'p'},
{"use-ipv4", no_argument, 0, '4'},
{"use-ipv6", no_argument, 0, '6'},
{"timeout", required_argument, 0, 't'},
{"verbose", no_argument, 0, 'v'},
{"remote-version", required_argument, 0, 'r'},
{"remote-protocol", required_argument, 0, 'P'},
{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");
while (1) {
c = getopt_long (argc, argv, "+Vhv46t:r:H:p:P:", longopts, &option);
if (c == -1 || c == EOF)
break;
switch (c) {
case '?': /* help */
usage5 ();
case 'V': /* version */
print_revision (progname, NP_VERSION);
exit (STATE_UNKNOWN);
case 'h': /* help */
print_help ();
exit (STATE_UNKNOWN);
case 'v': /* verbose */
verbose = true;
break;
case 't': /* timeout period */
if (!is_integer (optarg))
usage2 (_("Timeout interval must be a positive integer"), optarg);
else
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 'r': /* remote version */
remote_version = optarg;
break;
case 'P': /* remote version */
remote_protocol = optarg;
break;
case 'H': /* host */
if (!is_host (optarg))
usage2 (_("Invalid hostname/address"), optarg);
server_name = optarg;
break;
case 'p': /* port */
if (is_intpos (optarg)) {
port = atoi (optarg);
}
else {
usage2 (_("Port number must be a positive integer"), optarg);
}
}
}
c = optind;
if (server_name == NULL && c < argc) {
if (is_host (argv[c])) {
server_name = argv[c++];
}
}
if (port == -1 && c < argc) {
if (is_intpos (argv[c])) {
port = atoi (argv[c++]);
}
else {
print_usage ();
exit (STATE_UNKNOWN);
}
}
return validate_arguments ();
}
int
validate_arguments (void)
{
if (server_name == NULL)
return ERROR;
if (port == -1) /* funky, but allows -p to override stray integer in args */
port = SSH_DFL_PORT;
return OK;
}
/************************************************************************
*
* Try to connect to SSH server at specified server and port
*
*-----------------------------------------------------------------------*/
int
ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol)
{
int sd;
int result;
int len = 0;
ssize_t recv_ret = 0;
char *version_control_string = NULL;
char *buffer = NULL;
char *ssh_proto = NULL;
char *ssh_server = NULL;
static char *rev_no = VERSION;
struct timeval tv;
double elapsed_time;
gettimeofday(&tv, NULL);
result = my_tcp_connect (haddr, hport, &sd);
if (result != STATE_OK)
return result;
char *output = (char *) calloc (BUFF_SZ + 1, sizeof(char));
unsigned int iteration = 0;
ssize_t byte_offset = 0;
while ((version_control_string == NULL) && (recv_ret = recv(sd, output+byte_offset, BUFF_SZ - byte_offset, 0) > 0)) {
if (strchr(output, '\n')) { /* we've got at least one full line, start parsing*/
byte_offset = 0;
char *index = NULL;
while ((index = strchr(output+byte_offset, '\n')) != NULL) {
/*Partition the buffer so that this line is a separate string,
* by replacing the newline with NUL*/
output[(index - output)] = '\0';
len = strlen(output + byte_offset);
if ((len >= 4) && (strncmp (output+byte_offset, "SSH-", 4) == 0)) {
/*if the string starts with SSH-, this _should_ be a valid version control string*/
version_control_string = output+byte_offset;
break;
}
/*the start of the next line (if one exists) will be after the current one (+ NUL)*/
byte_offset += (len + 1);
}
if(version_control_string == NULL) {
/* move unconsumed data to beginning of buffer, null rest */
memmove((void *)output, (void *)output+byte_offset+1, BUFF_SZ - len+1);
memset(output+byte_offset+1, 0, BUFF_SZ-byte_offset+1);
/*start reading from end of current line chunk on next recv*/
byte_offset = strlen(output);
}
} else {
byte_offset += recv_ret;
}
}
if (recv_ret < 0) {
printf("SSH CRITICAL - %s", strerror(errno));
exit(STATE_CRITICAL);
}
if (version_control_string == NULL) {
printf("SSH CRITICAL - No version control string received");
exit(STATE_CRITICAL);
}
/*
* "When the connection has been established, both sides MUST send an
* identification string. This identification string MUST be
*
* SSH-protoversion-softwareversion SP comments CR LF"
* - RFC 4253:4.2
*/
strip (version_control_string);
if (verbose)
printf ("%s\n", version_control_string);
ssh_proto = version_control_string + 4;
/*
* We assume the protoversion is of the form Major.Minor, although
* this is not _strictly_ required. See
*
* "Both the 'protoversion' and 'softwareversion' strings MUST consist of
* printable US-ASCII characters, with the exception of whitespace
* characters and the minus sign (-)"
* - RFC 4253:4.2
* and,
*
* "As stated earlier, the 'protoversion' specified for this protocol is
* "2.0". Earlier versions of this protocol have not been formally
* documented, but it is widely known that they use 'protoversion' of
* "1.x" (e.g., "1.5" or "1.3")."
* - RFC 4253:5
*/
ssh_server = ssh_proto + strspn (ssh_proto, "0123456789.") + 1; /* (+1 for the '-' separating protoversion from softwareversion) */
/* If there's a space in the version string, whatever's after the space is a comment
* (which is NOT part of the server name/version)*/
char *tmp = strchr(ssh_server, ' ');
if (tmp) {
ssh_server[tmp - ssh_server] = '\0';
}
if (strlen(ssh_proto) == 0 || strlen(ssh_server) == 0) {
printf(_("SSH CRITICAL - Invalid protocol version control string %s\n"), version_control_string);
exit (STATE_CRITICAL);
}
ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
xasprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
if (verbose)
printf ("%s\n", buffer);
if (remote_version && strcmp(remote_version, ssh_server)) {
printf
(_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"),
ssh_server, ssh_proto, remote_version);
close(sd);
exit (STATE_CRITICAL);
}
if (remote_protocol && strcmp(remote_protocol, ssh_proto)) {
printf
(_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s' | %s\n"),
ssh_server, ssh_proto, remote_protocol, fperfdata("time", elapsed_time, "s",
false, 0, false, 0, true, 0, true, (int)socket_timeout));
close(sd);
exit (STATE_CRITICAL);
}
elapsed_time = (double)deltime(tv) / 1.0e6;
printf
(_("SSH OK - %s (protocol %s) | %s\n"),
ssh_server, ssh_proto, fperfdata("time", elapsed_time, "s",
false, 0, false, 0, true, 0, true, (int)socket_timeout));
close(sd);
exit (STATE_OK);
}
void
print_help (void)
{
char *myport;
xasprintf (&myport, "%d", SSH_DFL_PORT);
print_revision (progname, NP_VERSION);
printf ("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
printf (COPYRIGHT, copyright, email);
printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
printf ("\n\n");
print_usage ();
printf (UT_HELP_VRSN);
printf (UT_EXTRA_OPTS);
printf (UT_HOST_PORT, 'p', myport);
printf (UT_IPv46);
printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
printf (" %s\n", "-r, --remote-version=STRING");
printf (" %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
printf (" %s\n", "-P, --remote-protocol=STRING");
printf (" %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
printf (UT_VERBOSE);
printf (UT_SUPPORT);
}
void
print_usage (void)
{
printf ("%s\n", _("Usage:"));
printf ("%s [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
}
Reference in a new issue View git blame Copy permalink