1 /******************************************************************************
2 *
3 * Nagios check_ssh plugin
4 *
5 * License: GPL
6 * Copyright (c) 1999-2006 nagios-plugins team
7 *
8 * Last Modified: $Date$
9 *
10 * Description:
11 *
12 * This file contains the check_ssh plugin
13 *
14 *
15 * Try to connect to an SSH server at specified server and port
16 *
17 *
18 * License Information:
19 *
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
29 *
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software
32 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 *
34 * $Id$
35 *
36 ******************************************************************************/
38 const char *progname = "check_ssh";
39 const char *revision = "$Revision$";
40 const char *copyright = "2000-2006";
41 const char *email = "nagiosplug-devel@lists.sourceforge.net";
43 #include "common.h"
44 #include "netutils.h"
45 #include "utils.h"
47 #ifndef MSG_DONTWAIT
48 #define MSG_DONTWAIT 0
49 #endif
51 #define SSH_DFL_PORT 22
52 #define BUFF_SZ 256
54 int port = -1;
55 char *server_name = NULL;
56 char *remote_version = NULL;
57 int verbose = FALSE;
59 int process_arguments (int, char **);
60 int validate_arguments (void);
61 void print_help (void);
62 void print_usage (void);
64 int ssh_connect (char *haddr, int hport, char *remote_version);
68 int
69 main (int argc, char **argv)
70 {
71 int result = STATE_UNKNOWN;
73 setlocale (LC_ALL, "");
74 bindtextdomain (PACKAGE, LOCALEDIR);
75 textdomain (PACKAGE);
77 if (process_arguments (argc, argv) == ERROR)
78 usage4 (_("Could not parse arguments"));
80 /* initialize alarm signal handling */
81 signal (SIGALRM, socket_timeout_alarm_handler);
83 alarm (socket_timeout);
85 /* ssh_connect exits if error is found */
86 result = ssh_connect (server_name, port, remote_version);
88 alarm (0);
90 return (result);
91 }
95 /* process command-line arguments */
96 int
97 process_arguments (int argc, char **argv)
98 {
99 int c;
101 int option = 0;
102 static struct option longopts[] = {
103 {"help", no_argument, 0, 'h'},
104 {"version", no_argument, 0, 'V'},
105 {"host", required_argument, 0, 'H'}, /* backward compatibility */
106 {"hostname", required_argument, 0, 'H'},
107 {"port", required_argument, 0, 'p'},
108 {"use-ipv4", no_argument, 0, '4'},
109 {"use-ipv6", no_argument, 0, '6'},
110 {"timeout", required_argument, 0, 't'},
111 {"verbose", no_argument, 0, 'v'},
112 {"remote-version", required_argument, 0, 'r'},
113 {0, 0, 0, 0}
114 };
116 if (argc < 2)
117 return ERROR;
119 for (c = 1; c < argc; c++)
120 if (strcmp ("-to", argv[c]) == 0)
121 strcpy (argv[c], "-t");
123 while (1) {
124 c = getopt_long (argc, argv, "+Vhv46t:r:H:p:", longopts, &option);
126 if (c == -1 || c == EOF)
127 break;
129 switch (c) {
130 case '?': /* help */
131 usage5 ();
132 case 'V': /* version */
133 print_revision (progname, revision);
134 exit (STATE_OK);
135 case 'h': /* help */
136 print_help ();
137 exit (STATE_OK);
138 case 'v': /* verbose */
139 verbose = TRUE;
140 break;
141 case 't': /* timeout period */
142 if (!is_integer (optarg))
143 usage2 (_("Timeout interval must be a positive integer"), optarg);
144 else
145 socket_timeout = atoi (optarg);
146 break;
147 case '4':
148 address_family = AF_INET;
149 break;
150 case '6':
151 #ifdef USE_IPV6
152 address_family = AF_INET6;
153 #else
154 usage4 (_("IPv6 support not available"));
155 #endif
156 break;
157 case 'r': /* remote version */
158 remote_version = optarg;
159 break;
160 case 'H': /* host */
161 if (is_host (optarg) == FALSE)
162 usage2 (_("Invalid hostname/address"), optarg);
163 server_name = optarg;
164 break;
165 case 'p': /* port */
166 if (is_intpos (optarg)) {
167 port = atoi (optarg);
168 }
169 else {
170 usage2 (_("Port number must be a positive integer"), optarg);
171 }
172 }
173 }
175 c = optind;
176 if (server_name == NULL && c < argc) {
177 if (is_host (argv[c])) {
178 server_name = argv[c++];
179 }
180 }
182 if (port == -1 && c < argc) {
183 if (is_intpos (argv[c])) {
184 port = atoi (argv[c++]);
185 }
186 else {
187 print_usage ();
188 exit (STATE_UNKNOWN);
189 }
190 }
192 return validate_arguments ();
193 }
195 int
196 validate_arguments (void)
197 {
198 if (server_name == NULL)
199 return ERROR;
200 if (port == -1) /* funky, but allows -p to override stray integer in args */
201 port = SSH_DFL_PORT;
202 return OK;
203 }
206 /************************************************************************
207 *
208 * Try to connect to SSH server at specified server and port
209 *
210 *-----------------------------------------------------------------------*/
213 int
214 ssh_connect (char *haddr, int hport, char *remote_version)
215 {
216 int sd;
217 int result;
218 char *output = NULL;
219 char *buffer = NULL;
220 char *ssh_proto = NULL;
221 char *ssh_server = NULL;
222 char rev_no[20];
224 sscanf ("$Revision$", "$Revision: %[0123456789.]", rev_no);
226 result = my_tcp_connect (haddr, hport, &sd);
228 if (result != STATE_OK)
229 return result;
231 output = (char *) malloc (BUFF_SZ + 1);
232 memset (output, 0, BUFF_SZ + 1);
233 recv (sd, output, BUFF_SZ, 0);
234 if (strncmp (output, "SSH", 3)) {
235 printf (_("Server answer: %s"), output);
236 exit (STATE_CRITICAL);
237 }
238 else {
239 strip (output);
240 if (verbose)
241 printf ("%s\n", output);
242 ssh_proto = output + 4;
243 ssh_server = ssh_proto + strspn (ssh_proto, "-0123456789. ");
244 ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
246 asprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
247 send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
248 if (verbose)
249 printf ("%s\n", buffer);
251 if (remote_version && strcmp(remote_version, ssh_server)) {
252 printf
253 (_("SSH WARNING - %s (protocol %s) version mismatch, expected '%s'\n"),
254 ssh_server, ssh_proto, remote_version);
255 exit (STATE_WARNING);
256 }
258 printf
259 (_("SSH OK - %s (protocol %s)\n"),
260 ssh_server, ssh_proto);
261 close(sd);
262 exit (STATE_OK);
263 }
264 }
268 void
269 print_help (void)
270 {
271 char *myport;
272 asprintf (&myport, "%d", SSH_DFL_PORT);
274 print_revision (progname, revision);
276 printf ("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
277 printf (COPYRIGHT, copyright, email);
279 printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
281 printf ("\n\n");
283 print_usage ();
285 printf (_(UT_HELP_VRSN));
287 printf (_(UT_HOST_PORT), 'p', myport);
289 printf (_(UT_IPv46));
291 printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);
293 printf (" %s\n", "-r, --remote-version=STRING");
294 printf (" %s\n", _("Warn if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
296 printf (_(UT_VERBOSE));
298 printf (_(UT_SUPPORT));
299 }
303 void
304 print_usage (void)
305 {
306 printf (_("Usage:"));
307 printf ("%s [-46] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
308 }