plugins/check_ssh.c

   1 /*****************************************************************************
   2 *
   3 * Monitoring check_ssh plugin
   4 *
   5 * License: GPL
   6 * Copyright (c) 2000-2007 Monitoring Plugins Development Team
   7 *
   8 * Description:
   9 *
  10 * This file contains the check_ssh plugin
  11 *
  12 * Try to connect to an SSH server at specified server and port
  13 *
  14 *
  15 * This program is free software: you can redistribute it and/or modify
  16 * it under the terms of the GNU General Public License as published by
  17 * the Free Software Foundation, either version 3 of the License, or
  18 * (at your option) any later version.
  19 *
  20 * This program is distributed in the hope that it will be useful,
  21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 * GNU General Public License for more details.
  24 *
  25 * You should have received a copy of the GNU General Public License
  26 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  27 *
  28 *
  29 *****************************************************************************/
  30
  31 const char *progname = "check_ssh";
  32 const char *copyright = "2000-2007";
  33 const char *email = "devel@monitoring-plugins.org";
  34
  35 #include "common.h"
  36 #include "netutils.h"
  37 #include "utils.h"
  38
  39 #ifndef MSG_DONTWAIT
  40 #define MSG_DONTWAIT 0
  41 #endif
  42
  43 #define SSH_DFL_PORT    22
  44 #define BUFF_SZ         256
  45
  46 int port = -1;
  47 char *server_name = NULL;
  48 char *remote_version = NULL;
  49 char *remote_protocol = NULL;
  50 int verbose = FALSE;
  51
  52 int process_arguments (int, char **);
  53 int validate_arguments (void);
  54 void print_help (void);
  55 void print_usage (void);
  56
  57 int ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol);
  58
  59
  60
  61 int
  62 main (int argc, char **argv)
  63 {
  64         int result = STATE_UNKNOWN;
  65
  66         setlocale (LC_ALL, "");
  67         bindtextdomain (PACKAGE, LOCALEDIR);
  68         textdomain (PACKAGE);
  69
  70         /* Parse extra opts if any */
  71         argv=np_extra_opts (&argc, argv, progname);
  72
  73         if (process_arguments (argc, argv) == ERROR)
  74                 usage4 (_("Could not parse arguments"));
  75
  76         /* initialize alarm signal handling */
  77         signal (SIGALRM, socket_timeout_alarm_handler);
  78
  79         alarm (socket_timeout);
  80
  81         /* ssh_connect exits if error is found */
  82         result = ssh_connect (server_name, port, remote_version, remote_protocol);
  83
  84         alarm (0);
  85
  86         return (result);
  87 }
  88
  89
  90
  91 /* process command-line arguments */
  92 int
  93 process_arguments (int argc, char **argv)
  94 {
  95         int c;
  96
  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                 {"remote-protcol", required_argument, 0, 'P'},
 110                 {0, 0, 0, 0}
 111         };
 112
 113         if (argc < 2)
 114                 return ERROR;
 115
 116         for (c = 1; c < argc; c++)
 117                 if (strcmp ("-to", argv[c]) == 0)
 118                         strcpy (argv[c], "-t");
 119
 120         while (1) {
 121                 c = getopt_long (argc, argv, "+Vhv46t:r:H:p:P:", longopts, &option);
 122
 123                 if (c == -1 || c == EOF)
 124                         break;
 125
 126                 switch (c) {
 127                 case '?':                                                                       /* help */
 128                         usage5 ();
 129                 case 'V':                                                                       /* version */
 130                         print_revision (progname, NP_VERSION);
 131                         exit (STATE_UNKNOWN);
 132                 case 'h':                                                                       /* help */
 133                         print_help ();
 134                         exit (STATE_UNKNOWN);
 135                 case 'v':                                                                       /* verbose */
 136                         verbose = TRUE;
 137                         break;
 138                 case 't':                                                                       /* timeout period */
 139                         if (!is_integer (optarg))
 140                                 usage2 (_("Timeout interval must be a positive integer"), optarg);
 141                         else
 142                                 socket_timeout = atoi (optarg);
 143                         break;
 144                 case '4':
 145                         address_family = AF_INET;
 146                         break;
 147                 case '6':
 148 #ifdef USE_IPV6
 149                         address_family = AF_INET6;
 150 #else
 151                         usage4 (_("IPv6 support not available"));
 152 #endif
 153                         break;
 154                 case 'r':                                                                       /* remote version */
 155                         remote_version = optarg;
 156                         break;
 157                 case 'P':                                                                       /* remote version */
 158                         remote_protocol = 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         }
 174
 175         c = optind;
 176         if (server_name == NULL && c < argc) {
 177                 if (is_host (argv[c])) {
 178                         server_name = argv[c++];
 179                 }
 180         }
 181
 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         }
 191
 192         return validate_arguments ();
 193 }
 194
 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 }
 204
 205
 206 /************************************************************************
 207 *
 208 * Try to connect to SSH server at specified server and port
 209 *
 210 *-----------------------------------------------------------------------*/
 211
 212
 213 int
 214 ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol)
 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         static char *rev_no = VERSION;
 223         struct timeval tv;
 224         double elapsed_time;
 225
 226         gettimeofday(&tv, NULL);
 227
 228         result = my_tcp_connect (haddr, hport, &sd);
 229
 230         if (result != STATE_OK)
 231                 return result;
 232
 233         output = (char *) malloc (BUFF_SZ + 1);
 234         memset (output, 0, BUFF_SZ + 1);
 235         recv (sd, output, BUFF_SZ, 0);
 236         if (strncmp (output, "SSH", 3)) {
 237                 printf (_("Server answer: %s"), output);
 238                 close(sd);
 239                 exit (STATE_CRITICAL);
 240         }
 241         else {
 242                 strip (output);
 243                 if (verbose)
 244                         printf ("%s\n", output);
 245                 ssh_proto = output + 4;
 246                 ssh_server = ssh_proto + strspn (ssh_proto, "-0123456789. ");
 247                 ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
 248
 249                 xasprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
 250                 send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
 251                 if (verbose)
 252                         printf ("%s\n", buffer);
 253
 254                 if (remote_version && strcmp(remote_version, ssh_server)) {
 255                         printf
 256                                 (_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"),
 257                                  ssh_server, ssh_proto, remote_version);
 258                         close(sd);
 259                         exit (STATE_CRITICAL);
 260                 }
 261
 262                 if (remote_protocol && strcmp(remote_protocol, ssh_proto)) {
 263                         printf
 264                                 (_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s'\n"),
 265                                  ssh_server, ssh_proto, remote_protocol);
 266                         close(sd);
 267                         exit (STATE_CRITICAL);
 268                 }
 269
 270                 elapsed_time = (double)deltime(tv) / 1.0e6;
 271
 272                 printf
 273                         (_("SSH OK - %s (protocol %s) | %s\n"),
 274                          ssh_server, ssh_proto, fperfdata("time", elapsed_time, "s",
 275                          FALSE, 0, FALSE, 0, TRUE, 0, TRUE, (int)socket_timeout));
 276                 close(sd);
 277                 exit (STATE_OK);
 278         }
 279 }
 280
 281
 282
 283 void
 284 print_help (void)
 285 {
 286         char *myport;
 287         xasprintf (&myport, "%d", SSH_DFL_PORT);
 288
 289         print_revision (progname, NP_VERSION);
 290
 291         printf ("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
 292         printf (COPYRIGHT, copyright, email);
 293
 294         printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
 295
 296   printf ("\n\n");
 297
 298         print_usage ();
 299
 300         printf (UT_HELP_VRSN);
 301         printf (UT_EXTRA_OPTS);
 302
 303         printf (UT_HOST_PORT, 'p', myport);
 304
 305         printf (UT_IPv46);
 306
 307         printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
 308
 309         printf (" %s\n", "-r, --remote-version=STRING");
 310   printf ("    %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
 311
 312         printf (" %s\n", "-P, --remote-protocol=STRING");
 313   printf ("    %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
 314
 315         printf (UT_VERBOSE);
 316
 317         printf (UT_SUPPORT);
 318 }
 319
 320
 321
 322 void
 323 print_usage (void)
 324 {
 325   printf ("%s\n", _("Usage:"));
 326         printf ("%s  [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
 327 }
 328