1 /*****************************************************************************
2 *
3 * Nagios check_ssh plugin
4 *
5 * License: GPL
6 * Copyright (c) 2000-2007 Nagios Plugins Development Team
7 *
8 * Last Modified: $Date$
9 *
10 * Description:
11 *
12 * This file contains the check_ssh plugin
13 *
14 * Try to connect to an SSH server at specified server and port
15 *
16 *
17 * This program is free software: you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation, either version 3 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program. If not, see <http://www.gnu.org/licenses/>.
29 *
30 * $Id$
31 *
32 *****************************************************************************/
34 const char *progname = "check_ssh";
35 const char *revision = "$Revision$";
36 const char *copyright = "2000-2007";
37 const char *email = "nagiosplug-devel@lists.sourceforge.net";
39 #include "common.h"
40 #include "netutils.h"
41 #include "utils.h"
43 #ifndef MSG_DONTWAIT
44 #define MSG_DONTWAIT 0
45 #endif
47 #define SSH_DFL_PORT 22
48 #define BUFF_SZ 256
50 int port = -1;
51 char *server_name = NULL;
52 char *remote_version = NULL;
53 int verbose = FALSE;
55 int process_arguments (int, char **);
56 int validate_arguments (void);
57 void print_help (void);
58 void print_usage (void);
60 int ssh_connect (char *haddr, int hport, char *remote_version);
64 int
65 main (int argc, char **argv)
66 {
67 int result = STATE_UNKNOWN;
69 setlocale (LC_ALL, "");
70 bindtextdomain (PACKAGE, LOCALEDIR);
71 textdomain (PACKAGE);
73 if (process_arguments (argc, argv) == ERROR)
74 usage4 (_("Could not parse arguments"));
76 /* initialize alarm signal handling */
77 signal (SIGALRM, socket_timeout_alarm_handler);
79 alarm (socket_timeout);
81 /* ssh_connect exits if error is found */
82 result = ssh_connect (server_name, port, remote_version);
84 alarm (0);
86 return (result);
87 }
91 /* process command-line arguments */
92 int
93 process_arguments (int argc, char **argv)
94 {
95 int c;
97 int option = 0;
98 static struct option longopts[] = {
99 {"help", no_argument, 0, 'h'},
100 {"version", no_argument, 0, 'V'},
101 {"host", required_argument, 0, 'H'}, /* backward compatibility */
102 {"hostname", required_argument, 0, 'H'},
103 {"port", required_argument, 0, 'p'},
104 {"use-ipv4", no_argument, 0, '4'},
105 {"use-ipv6", no_argument, 0, '6'},
106 {"timeout", required_argument, 0, 't'},
107 {"verbose", no_argument, 0, 'v'},
108 {"remote-version", required_argument, 0, 'r'},
109 {0, 0, 0, 0}
110 };
112 if (argc < 2)
113 return ERROR;
115 for (c = 1; c < argc; c++)
116 if (strcmp ("-to", argv[c]) == 0)
117 strcpy (argv[c], "-t");
119 while (1) {
120 c = getopt_long (argc, argv, "+Vhv46t:r:H:p:", longopts, &option);
122 if (c == -1 || c == EOF)
123 break;
125 switch (c) {
126 case '?': /* help */
127 usage5 ();
128 case 'V': /* version */
129 print_revision (progname, revision);
130 exit (STATE_OK);
131 case 'h': /* help */
132 print_help ();
133 exit (STATE_OK);
134 case 'v': /* verbose */
135 verbose = TRUE;
136 break;
137 case 't': /* timeout period */
138 if (!is_integer (optarg))
139 usage2 (_("Timeout interval must be a positive integer"), optarg);
140 else
141 socket_timeout = atoi (optarg);
142 break;
143 case '4':
144 address_family = AF_INET;
145 break;
146 case '6':
147 #ifdef USE_IPV6
148 address_family = AF_INET6;
149 #else
150 usage4 (_("IPv6 support not available"));
151 #endif
152 break;
153 case 'r': /* remote version */
154 remote_version = optarg;
155 break;
156 case 'H': /* host */
157 if (is_host (optarg) == FALSE)
158 usage2 (_("Invalid hostname/address"), optarg);
159 server_name = optarg;
160 break;
161 case 'p': /* port */
162 if (is_intpos (optarg)) {
163 port = atoi (optarg);
164 }
165 else {
166 usage2 (_("Port number must be a positive integer"), optarg);
167 }
168 }
169 }
171 c = optind;
172 if (server_name == NULL && c < argc) {
173 if (is_host (argv[c])) {
174 server_name = argv[c++];
175 }
176 }
178 if (port == -1 && c < argc) {
179 if (is_intpos (argv[c])) {
180 port = atoi (argv[c++]);
181 }
182 else {
183 print_usage ();
184 exit (STATE_UNKNOWN);
185 }
186 }
188 return validate_arguments ();
189 }
191 int
192 validate_arguments (void)
193 {
194 if (server_name == NULL)
195 return ERROR;
196 if (port == -1) /* funky, but allows -p to override stray integer in args */
197 port = SSH_DFL_PORT;
198 return OK;
199 }
202 /************************************************************************
203 *
204 * Try to connect to SSH server at specified server and port
205 *
206 *-----------------------------------------------------------------------*/
209 int
210 ssh_connect (char *haddr, int hport, char *remote_version)
211 {
212 int sd;
213 int result;
214 char *output = NULL;
215 char *buffer = NULL;
216 char *ssh_proto = NULL;
217 char *ssh_server = NULL;
218 char rev_no[20];
220 sscanf ("$Revision$", "$Revision: %[0123456789.]", rev_no);
222 result = my_tcp_connect (haddr, hport, &sd);
224 if (result != STATE_OK)
225 return result;
227 output = (char *) malloc (BUFF_SZ + 1);
228 memset (output, 0, BUFF_SZ + 1);
229 recv (sd, output, BUFF_SZ, 0);
230 if (strncmp (output, "SSH", 3)) {
231 printf (_("Server answer: %s"), output);
232 close(sd);
233 exit (STATE_CRITICAL);
234 }
235 else {
236 strip (output);
237 if (verbose)
238 printf ("%s\n", output);
239 ssh_proto = output + 4;
240 ssh_server = ssh_proto + strspn (ssh_proto, "-0123456789. ");
241 ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
243 asprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
244 send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
245 if (verbose)
246 printf ("%s\n", buffer);
248 if (remote_version && strcmp(remote_version, ssh_server)) {
249 printf
250 (_("SSH WARNING - %s (protocol %s) version mismatch, expected '%s'\n"),
251 ssh_server, ssh_proto, remote_version);
252 close(sd);
253 exit (STATE_WARNING);
254 }
256 printf
257 (_("SSH OK - %s (protocol %s)\n"),
258 ssh_server, ssh_proto);
259 close(sd);
260 exit (STATE_OK);
261 }
262 }
266 void
267 print_help (void)
268 {
269 char *myport;
270 asprintf (&myport, "%d", SSH_DFL_PORT);
272 print_revision (progname, revision);
274 printf ("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
275 printf (COPYRIGHT, copyright, email);
277 printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
279 printf ("\n\n");
281 print_usage ();
283 printf (_(UT_HELP_VRSN));
285 printf (_(UT_HOST_PORT), 'p', myport);
287 printf (_(UT_IPv46));
289 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
291 printf (" %s\n", "-r, --remote-version=STRING");
292 printf (" %s\n", _("Warn if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
294 printf (_(UT_VERBOSE));
296 printf (_(UT_SUPPORT));
297 }
301 void
302 print_usage (void)
303 {
304 printf (_("Usage:"));
305 printf ("%s [-46] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
306 }