plugins/netutils.c

   1 /****************************************************************************
   2 *
   3 * Nagios plugins network utilities
   4 *
   5 * License: GPL
   6 * Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
   7 *
   8 * Last Modified: $Date$
   9 *
  10 * Description:
  11 *
  12 * This file contains commons functions used in many of the plugins.
  13 *
  14 * License Information:
  15 *
  16 * This program is free software; you can redistribute it and/or modify
  17 * it under the terms of the GNU General Public License as published by
  18 * the Free Software Foundation; either version 2 of the License, or
  19 * (at your option) any later version.
  20 *
  21 * This program is distributed in the hope that it will be useful,
  22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 * GNU General Public License for more details.
  25 *
  26 * You should have received a copy of the GNU General Public License
  27 * along with this program; if not, write to the Free Software
  28 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  29 *
  30 * $Id$
  31 *
  32 ****************************************************************************/
  33
  34 #define LOCAL_TIMEOUT_ALARM_HANDLER
  35
  36 #include "common.h"
  37 #include "netutils.h"
  38
  39 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  40 int econn_refuse_state = STATE_CRITICAL;
  41 int was_refused = FALSE;
  42 #if USE_IPV6
  43 int address_family = AF_UNSPEC;
  44 #else
  45 int address_family = AF_INET;
  46 #endif
  47
  48 /* handles socket timeouts */
  49 void
  50 socket_timeout_alarm_handler (int sig)
  51 {
  52         if (sig == SIGALRM)
  53                 printf (_("CRITICAL - Socket timeout after %d seconds\n"), socket_timeout);
  54         else
  55                 printf (_("CRITICAL - Abnormal timeout after %d seconds\n"), socket_timeout);
  56
  57         exit (STATE_CRITICAL);
  58 }
  59
  60
  61 /* connects to a host on a specified tcp port, sends a string, and gets a
  62          response. loops on select-recv until timeout or eof to get all of a
  63          multi-packet answer */
  64 int
  65 process_tcp_request2 (const char *server_address, int server_port,
  66         const char *send_buffer, char *recv_buffer, int recv_size)
  67 {
  68
  69         int result;
  70         int send_result;
  71         int recv_result;
  72         int sd;
  73         struct timeval tv;
  74         fd_set readfds;
  75         int recv_length = 0;
  76
  77         result = np_net_connect (server_address, server_port, &sd, IPPROTO_TCP);
  78         if (result != STATE_OK)
  79                 return STATE_CRITICAL;
  80
  81         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
  82         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
  83                 printf ("%s\n", _("Send failed"));
  84                 result = STATE_WARNING;
  85         }
  86
  87         while (1) {
  88                 /* wait up to the number of seconds for socket timeout
  89                    minus one for data from the host */
  90                 tv.tv_sec = socket_timeout - 1;
  91                 tv.tv_usec = 0;
  92                 FD_ZERO (&readfds);
  93                 FD_SET (sd, &readfds);
  94                 select (sd + 1, &readfds, NULL, NULL, &tv);
  95
  96                 /* make sure some data has arrived */
  97                 if (!FD_ISSET (sd, &readfds)) { /* it hasn't */
  98                         if (!recv_length) {
  99                                 strcpy (recv_buffer, "");
 100                                 printf ("%s\n", _("No data was received from host!"));
 101                                 result = STATE_WARNING;
 102                         }
 103                         else {                                                                          /* this one failed, but previous ones worked */
 104                                 recv_buffer[recv_length] = 0;
 105                         }
 106                         break;
 107                 }
 108                 else {                                                                                  /* it has */
 109                         recv_result =
 110                                 recv (sd, recv_buffer + recv_length,
 111                                         (size_t)recv_size - recv_length - 1, 0);
 112                         if (recv_result == -1) {
 113                                 /* recv failed, bail out */
 114                                 strcpy (recv_buffer + recv_length, "");
 115                                 result = STATE_WARNING;
 116                                 break;
 117                         }
 118                         else if (recv_result == 0) {
 119                                 /* end of file ? */
 120                                 recv_buffer[recv_length] = 0;
 121                                 break;
 122                         }
 123                         else {                                                                          /* we got data! */
 124                                 recv_length += recv_result;
 125                                 if (recv_length >= recv_size - 1) {
 126                                         /* buffer full, we're done */
 127                                         recv_buffer[recv_size - 1] = 0;
 128                                         break;
 129                                 }
 130                         }
 131                 }
 132                 /* end if(!FD_ISSET(sd,&readfds)) */
 133         }
 134         /* end while(1) */
 135
 136         close (sd);
 137         return result;
 138 }
 139
 140
 141 /* connects to a host on a specified port, sends a string, and gets a
 142    response */
 143 int
 144 process_request (const char *server_address, int server_port, int proto,
 145         const char *send_buffer, char *recv_buffer, int recv_size)
 146 {
 147         int result;
 148         int sd;
 149
 150         result = STATE_OK;
 151
 152         result = np_net_connect (server_address, server_port, &sd, proto);
 153         if (result != STATE_OK)
 154                 return STATE_CRITICAL;
 155
 156         result = send_request (sd, proto, send_buffer, recv_buffer, recv_size);
 157
 158         close (sd);
 159
 160         return result;
 161 }
 162
 163
 164 /* opens a tcp or udp connection to a remote host or local socket */
 165 int
 166 np_net_connect (const char *host_name, int port, int *sd, int proto)
 167 {
 168         struct addrinfo hints;
 169         struct addrinfo *r, *res;
 170         struct sockaddr_un su;
 171         char port_str[6], host[MAX_HOST_ADDRESS_LENGTH];
 172         size_t len;
 173         int socktype, result;
 174
 175         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 176
 177         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 178         if(host_name[0] != '/'){
 179                 memset (&hints, 0, sizeof (hints));
 180                 hints.ai_family = address_family;
 181                 hints.ai_protocol = proto;
 182                 hints.ai_socktype = socktype;
 183
 184                 len = strlen (host_name);
 185                 /* check for an [IPv6] address (and strip the brackets) */
 186                 if (len >= 2 && host_name[0] == '[' && host_name[len - 1] == ']') {
 187                         host_name++;
 188                         len -= 2;
 189                 }
 190                 if (len >= sizeof(host))
 191                         return STATE_UNKNOWN;
 192                 memcpy (host, host_name, len);
 193                 host[len] = '\0';
 194                 snprintf (port_str, sizeof (port_str), "%d", port);
 195                 result = getaddrinfo (host, port_str, &hints, &res);
 196
 197                 if (result != 0) {
 198                         printf ("%s\n", gai_strerror (result));
 199                         return STATE_UNKNOWN;
 200                 }
 201
 202                 r = res;
 203                 while (r) {
 204                         /* attempt to create a socket */
 205                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 206
 207                         if (*sd < 0) {
 208                                 printf ("%s\n", _("Socket creation failed"));
 209                                 freeaddrinfo (r);
 210                                 return STATE_UNKNOWN;
 211                         }
 212
 213                         /* attempt to open a connection */
 214                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 215
 216                         if (result == 0) {
 217                                 was_refused = FALSE;
 218                                 break;
 219                         }
 220
 221                         if (result < 0) {
 222                                 switch (errno) {
 223                                 case ECONNREFUSED:
 224                                         was_refused = TRUE;
 225                                         break;
 226                                 }
 227                         }
 228
 229                         close (*sd);
 230                         r = r->ai_next;
 231                 }
 232                 freeaddrinfo (res);
 233         }
 234         /* else the hostname is interpreted as a path to a unix socket */
 235         else {
 236                 if(strlen(host_name) >= UNIX_PATH_MAX){
 237                         die(STATE_UNKNOWN, _("Supplied path too long unix domain socket"));
 238                 }
 239                 memset(&su, 0, sizeof(su));
 240                 su.sun_family = AF_UNIX;
 241                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 242                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 243                 if(*sd < 0){
 244                         die(STATE_UNKNOWN, _("Socket creation failed"));
 245                 }
 246                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 247                 if (result < 0 && errno == ECONNREFUSED)
 248                         was_refused = TRUE;
 249         }
 250
 251         if (result == 0)
 252                 return STATE_OK;
 253         else if (was_refused) {
 254                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 255                 case STATE_OK:
 256                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 257                         return econn_refuse_state;
 258                         break;
 259                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 260                         printf ("%s\n", strerror(errno));
 261                         return econn_refuse_state;
 262                         break;
 263                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 264                         return STATE_UNKNOWN;
 265                         break;
 266                 }
 267         }
 268         else {
 269                 printf ("%s\n", strerror(errno));
 270                 return STATE_CRITICAL;
 271         }
 272 }
 273
 274 int
 275 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 276 {
 277         int result = STATE_OK;
 278         int send_result;
 279         int recv_result;
 280         struct timeval tv;
 281         fd_set readfds;
 282
 283         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 284         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 285                 printf ("%s\n", _("Send failed"));
 286                 result = STATE_WARNING;
 287         }
 288
 289         /* wait up to the number of seconds for socket timeout minus one
 290            for data from the host */
 291         tv.tv_sec = socket_timeout - 1;
 292         tv.tv_usec = 0;
 293         FD_ZERO (&readfds);
 294         FD_SET (sd, &readfds);
 295         select (sd + 1, &readfds, NULL, NULL, &tv);
 296
 297         /* make sure some data has arrived */
 298         if (!FD_ISSET (sd, &readfds)) {
 299                 strcpy (recv_buffer, "");
 300                 printf ("%s\n", _("No data was received from host!"));
 301                 result = STATE_WARNING;
 302         }
 303
 304         else {
 305                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 306                 if (recv_result == -1) {
 307                         strcpy (recv_buffer, "");
 308                         if (proto != IPPROTO_TCP)
 309                                 printf ("%s\n", _("Receive failed"));
 310                         result = STATE_WARNING;
 311                 }
 312                 else
 313                         recv_buffer[recv_result] = 0;
 314
 315                 /* die returned string */
 316                 recv_buffer[recv_size - 1] = 0;
 317         }
 318         return result;
 319 }
 320
 321
 322 int
 323 is_host (const char *address)
 324 {
 325         if (is_addr (address) || is_hostname (address))
 326                 return (TRUE);
 327
 328         return (FALSE);
 329 }
 330
 331 void
 332 host_or_die(const char *str)
 333 {
 334         if(!str || (!is_addr(str) && !is_hostname(str)))
 335                 usage_va(_("Invalid hostname/address - %s"), str);
 336 }
 337
 338 int
 339 is_addr (const char *address)
 340 {
 341 #ifdef USE_IPV6
 342         if (address_family == AF_INET && is_inet_addr (address))
 343                 return TRUE;
 344         else if (address_family == AF_INET6 && is_inet6_addr (address))
 345                 return TRUE;
 346 #else
 347         if (is_inet_addr (address))
 348                 return (TRUE);
 349 #endif
 350
 351         return (FALSE);
 352 }
 353
 354 int
 355 resolve_host_or_addr (const char *address, int family)
 356 {
 357         struct addrinfo hints;
 358         struct addrinfo *res;
 359         int retval;
 360
 361         memset (&hints, 0, sizeof (hints));
 362         hints.ai_family = family;
 363         retval = getaddrinfo (address, NULL, &hints, &res);
 364
 365         if (retval != 0)
 366                 return FALSE;
 367         else {
 368                 freeaddrinfo (res);
 369                 return TRUE;
 370         }
 371 }