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 #include "common.h"
  35 #include "netutils.h"
  36
  37 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  38 int econn_refuse_state = STATE_CRITICAL;
  39 int was_refused = FALSE;
  40 int address_family = AF_UNSPEC;
  41
  42 /* handles socket timeouts */
  43 void
  44 socket_timeout_alarm_handler (int sig)
  45 {
  46         if (sig == SIGALRM)
  47                 printf (_("CRITICAL - Socket timeout after %d seconds\n"), socket_timeout);
  48         else
  49                 printf (_("CRITICAL - Abnormal timeout after %d seconds\n"), socket_timeout);
  50
  51         exit (STATE_CRITICAL);
  52 }
  53
  54
  55 /* connects to a host on a specified tcp port, sends a string, and gets a
  56          response. loops on select-recv until timeout or eof to get all of a
  57          multi-packet answer */
  58 int
  59 process_tcp_request2 (const char *server_address, int server_port,
  60         const char *send_buffer, char *recv_buffer, int recv_size)
  61 {
  62
  63         int result;
  64         int send_result;
  65         int recv_result;
  66         int sd;
  67         struct timeval tv;
  68         fd_set readfds;
  69         int recv_length = 0;
  70
  71         result = np_net_connect (server_address, server_port, &sd, IPPROTO_TCP);
  72         if (result != STATE_OK)
  73                 return STATE_CRITICAL;
  74
  75         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
  76         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
  77                 printf (_("Send failed\n"));
  78                 result = STATE_WARNING;
  79         }
  80
  81         while (1) {
  82                 /* wait up to the number of seconds for socket timeout
  83                    minus one for data from the host */
  84                 tv.tv_sec = socket_timeout - 1;
  85                 tv.tv_usec = 0;
  86                 FD_ZERO (&readfds);
  87                 FD_SET (sd, &readfds);
  88                 select (sd + 1, &readfds, NULL, NULL, &tv);
  89
  90                 /* make sure some data has arrived */
  91                 if (!FD_ISSET (sd, &readfds)) { /* it hasn't */
  92                         if (!recv_length) {
  93                                 strcpy (recv_buffer, "");
  94                                 printf (_("No data was received from host!\n"));
  95                                 result = STATE_WARNING;
  96                         }
  97                         else {                                                                          /* this one failed, but previous ones worked */
  98                                 recv_buffer[recv_length] = 0;
  99                         }
 100                         break;
 101                 }
 102                 else {                                                                                  /* it has */
 103                         recv_result =
 104                                 recv (sd, recv_buffer + recv_length,
 105                                         (size_t)recv_size - recv_length - 1, 0);
 106                         if (recv_result == -1) {
 107                                 /* recv failed, bail out */
 108                                 strcpy (recv_buffer + recv_length, "");
 109                                 result = STATE_WARNING;
 110                                 break;
 111                         }
 112                         else if (recv_result == 0) {
 113                                 /* end of file ? */
 114                                 recv_buffer[recv_length] = 0;
 115                                 break;
 116                         }
 117                         else {                                                                          /* we got data! */
 118                                 recv_length += recv_result;
 119                                 if (recv_length >= recv_size - 1) {
 120                                         /* buffer full, we're done */
 121                                         recv_buffer[recv_size - 1] = 0;
 122                                         break;
 123                                 }
 124                         }
 125                 }
 126                 /* end if(!FD_ISSET(sd,&readfds)) */
 127         }
 128         /* end while(1) */
 129
 130         close (sd);
 131         return result;
 132 }
 133
 134
 135 /* connects to a host on a specified port, sends a string, and gets a
 136    response */
 137 int
 138 process_request (const char *server_address, int server_port, int proto,
 139         const char *send_buffer, char *recv_buffer, int recv_size)
 140 {
 141         int result;
 142         int sd;
 143
 144         result = STATE_OK;
 145
 146         result = np_net_connect (server_address, server_port, &sd, proto);
 147         if (result != STATE_OK)
 148                 return STATE_CRITICAL;
 149
 150         result = send_request (sd, proto, send_buffer, recv_buffer, recv_size);
 151
 152         close (sd);
 153
 154         return result;
 155 }
 156
 157
 158 /* opens a tcp or udp connection to a remote host */
 159 int
 160 np_net_connect (const char *host_name, int port, int *sd, int proto)
 161 {
 162         struct addrinfo hints;
 163         struct addrinfo *res, *res0;
 164         char port_str[6];
 165         int result;
 166
 167         memset (&hints, 0, sizeof (hints));
 168         hints.ai_family = address_family;
 169         hints.ai_protocol = proto;
 170         hints.ai_socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 171
 172         snprintf (port_str, sizeof (port_str), "%d", port);
 173         result = getaddrinfo (host_name, port_str, &hints, &res0);
 174
 175         if (result != 0) {
 176                 printf ("%s\n", gai_strerror (result));
 177                 return STATE_UNKNOWN;
 178         }
 179         else {
 180                 res = res0;
 181                 while (res) {
 182                         /* attempt to create a socket */
 183                         *sd = socket (res->ai_family, (proto == IPPROTO_UDP) ?
 184                                       SOCK_DGRAM : SOCK_STREAM, res->ai_protocol);
 185
 186                         if (*sd < 0) {
 187                                 printf (_("Socket creation failed\n"));
 188                                 freeaddrinfo (res);
 189                                 return STATE_UNKNOWN;
 190                         }
 191
 192                         /* attempt to open a connection */
 193                         result = connect (*sd, res->ai_addr, res->ai_addrlen);
 194
 195                         if (result == 0) {
 196                                 was_refused = FALSE;
 197                                 break;
 198                         }
 199
 200                         if (result < 0) {
 201                                 switch (errno) {
 202                                 case ECONNREFUSED:
 203                                         was_refused = TRUE;
 204                                         break;
 205                                 }
 206                         }
 207
 208                         close (*sd);
 209                         res = res->ai_next;
 210                 }
 211                 freeaddrinfo (res0);
 212         }
 213
 214         if (result == 0)
 215                 return STATE_OK;
 216         else if (was_refused) {
 217                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 218                 case STATE_OK:
 219                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 220                         return econn_refuse_state;
 221                         break;
 222                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 223                         printf ("%s\n", strerror(errno));
 224                         return econn_refuse_state;
 225                         break;
 226                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 227                         return STATE_UNKNOWN;
 228                         break;
 229                 }
 230         }
 231         else {
 232                 printf ("%s\n", strerror(errno));
 233                 return STATE_CRITICAL;
 234         }
 235 }
 236
 237 int
 238 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 239 {
 240         int result = STATE_OK;
 241         int send_result;
 242         int recv_result;
 243         struct timeval tv;
 244         fd_set readfds;
 245
 246         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 247         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 248                 printf (_("Send failed\n"));
 249                 result = STATE_WARNING;
 250         }
 251
 252         /* wait up to the number of seconds for socket timeout minus one
 253            for data from the host */
 254         tv.tv_sec = socket_timeout - 1;
 255         tv.tv_usec = 0;
 256         FD_ZERO (&readfds);
 257         FD_SET (sd, &readfds);
 258         select (sd + 1, &readfds, NULL, NULL, &tv);
 259
 260         /* make sure some data has arrived */
 261         if (!FD_ISSET (sd, &readfds)) {
 262                 strcpy (recv_buffer, "");
 263                 printf (_("No data was received from host!\n"));
 264                 result = STATE_WARNING;
 265         }
 266
 267         else {
 268                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 269                 if (recv_result == -1) {
 270                         strcpy (recv_buffer, "");
 271                         if (proto != IPPROTO_TCP)
 272                                 printf (_("Receive failed\n"));
 273                         result = STATE_WARNING;
 274                 }
 275                 else
 276                         recv_buffer[recv_result] = 0;
 277
 278                 /* die returned string */
 279                 recv_buffer[recv_size - 1] = 0;
 280         }
 281         return result;
 282 }
 283
 284
 285 int
 286 is_host (const char *address)
 287 {
 288         if (is_addr (address) || is_hostname (address))
 289                 return (TRUE);
 290
 291         return (FALSE);
 292 }
 293
 294 int
 295 is_addr (const char *address)
 296 {
 297 #ifdef USE_IPV6
 298         if (is_inet_addr (address) && address_family != AF_INET6)
 299 #else
 300         if (is_inet_addr (address))
 301 #endif
 302                 return (TRUE);
 303
 304 #ifdef USE_IPV6
 305         if (is_inet6_addr (address) && address_family != AF_INET)
 306                 return (TRUE);
 307 #endif
 308
 309         return (FALSE);
 310 }
 311
 312 int
 313 resolve_host_or_addr (const char *address, int family)
 314 {
 315         struct addrinfo hints;
 316         struct addrinfo *res;
 317         int retval;
 318
 319         memset (&hints, 0, sizeof (hints));
 320         hints.ai_family = family;
 321         retval = getaddrinfo (address, NULL, &hints, &res);
 322
 323         if (retval != 0)
 324                 return FALSE;
 325         else {
 326                 freeaddrinfo (res);
 327                 return TRUE;
 328         }
 329 }