plugins/netutils.c

   1 /*****************************************************************************
   2 *
   3 * Nagios plugins network utilities
   4 *
   5 * License: GPL
   6 * Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
   7 * Copyright (c) 2003-2008 Nagios Plugins Development Team
   8 *
   9 * Last Modified: $Date$
  10 *
  11 * Description:
  12 *
  13 * This file contains commons functions used in many of the plugins.
  14 *
  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 3 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, see <http://www.gnu.org/licenses/>.
  28 *
  29 * $Id$
  30 *
  31 *****************************************************************************/
  32
  33 #define LOCAL_TIMEOUT_ALARM_HANDLER
  34
  35 #include "common.h"
  36 #include "netutils.h"
  37
  38 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  39 int econn_refuse_state = STATE_CRITICAL;
  40 int was_refused = FALSE;
  41 #if USE_IPV6
  42 int address_family = AF_UNSPEC;
  43 #else
  44 int address_family = AF_INET;
  45 #endif
  46
  47 /* handles socket timeouts */
  48 void
  49 socket_timeout_alarm_handler (int sig)
  50 {
  51         if (sig == SIGALRM)
  52                 printf (_("CRITICAL - Socket timeout after %d seconds\n"), socket_timeout);
  53         else
  54                 printf (_("CRITICAL - Abnormal timeout after %d seconds\n"), socket_timeout);
  55
  56         exit (STATE_CRITICAL);
  57 }
  58
  59
  60 /* connects to a host on a specified tcp port, sends a string, and gets a
  61          response. loops on select-recv until timeout or eof to get all of a
  62          multi-packet answer */
  63 int
  64 process_tcp_request2 (const char *server_address, int server_port,
  65         const char *send_buffer, char *recv_buffer, int recv_size)
  66 {
  67
  68         int result;
  69         int send_result;
  70         int recv_result;
  71         int sd;
  72         struct timeval tv;
  73         fd_set readfds;
  74         int recv_length = 0;
  75
  76         result = np_net_connect (server_address, server_port, &sd, IPPROTO_TCP);
  77         if (result != STATE_OK)
  78                 return STATE_CRITICAL;
  79
  80         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
  81         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
  82                 printf ("%s\n", _("Send failed"));
  83                 result = STATE_WARNING;
  84         }
  85
  86         while (1) {
  87                 /* wait up to the number of seconds for socket timeout
  88                    minus one for data from the host */
  89                 tv.tv_sec = socket_timeout - 1;
  90                 tv.tv_usec = 0;
  91                 FD_ZERO (&readfds);
  92                 FD_SET (sd, &readfds);
  93                 select (sd + 1, &readfds, NULL, NULL, &tv);
  94
  95                 /* make sure some data has arrived */
  96                 if (!FD_ISSET (sd, &readfds)) { /* it hasn't */
  97                         if (!recv_length) {
  98                                 strcpy (recv_buffer, "");
  99                                 printf ("%s\n", _("No data was received from host!"));
 100                                 result = STATE_WARNING;
 101                         }
 102                         else {                                                                          /* this one failed, but previous ones worked */
 103                                 recv_buffer[recv_length] = 0;
 104                         }
 105                         break;
 106                 }
 107                 else {                                                                                  /* it has */
 108                         recv_result =
 109                                 recv (sd, recv_buffer + recv_length,
 110                                         (size_t)recv_size - recv_length - 1, 0);
 111                         if (recv_result == -1) {
 112                                 /* recv failed, bail out */
 113                                 strcpy (recv_buffer + recv_length, "");
 114                                 result = STATE_WARNING;
 115                                 break;
 116                         }
 117                         else if (recv_result == 0) {
 118                                 /* end of file ? */
 119                                 recv_buffer[recv_length] = 0;
 120                                 break;
 121                         }
 122                         else {                                                                          /* we got data! */
 123                                 recv_length += recv_result;
 124                                 if (recv_length >= recv_size - 1) {
 125                                         /* buffer full, we're done */
 126                                         recv_buffer[recv_size - 1] = 0;
 127                                         break;
 128                                 }
 129                         }
 130                 }
 131                 /* end if(!FD_ISSET(sd,&readfds)) */
 132         }
 133         /* end while(1) */
 134
 135         close (sd);
 136         return result;
 137 }
 138
 139
 140 /* connects to a host on a specified port, sends a string, and gets a
 141    response */
 142 int
 143 process_request (const char *server_address, int server_port, int proto,
 144         const char *send_buffer, char *recv_buffer, int recv_size)
 145 {
 146         int result;
 147         int sd;
 148
 149         result = STATE_OK;
 150
 151         result = np_net_connect (server_address, server_port, &sd, proto);
 152         if (result != STATE_OK)
 153                 return STATE_CRITICAL;
 154
 155         result = send_request (sd, proto, send_buffer, recv_buffer, recv_size);
 156
 157         close (sd);
 158
 159         return result;
 160 }
 161
 162
 163 /* opens a tcp or udp connection to a remote host or local socket */
 164 int
 165 np_net_connect (const char *host_name, int port, int *sd, int proto)
 166 {
 167         struct addrinfo hints;
 168         struct addrinfo *r, *res;
 169         struct sockaddr_un su;
 170         char port_str[6], host[MAX_HOST_ADDRESS_LENGTH];
 171         size_t len;
 172         int socktype, result;
 173
 174         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 175
 176         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 177         if(host_name[0] != '/'){
 178                 memset (&hints, 0, sizeof (hints));
 179                 hints.ai_family = address_family;
 180                 hints.ai_protocol = proto;
 181                 hints.ai_socktype = socktype;
 182
 183                 len = strlen (host_name);
 184                 /* check for an [IPv6] address (and strip the brackets) */
 185                 if (len >= 2 && host_name[0] == '[' && host_name[len - 1] == ']') {
 186                         host_name++;
 187                         len -= 2;
 188                 }
 189                 if (len >= sizeof(host))
 190                         return STATE_UNKNOWN;
 191                 memcpy (host, host_name, len);
 192                 host[len] = '\0';
 193                 snprintf (port_str, sizeof (port_str), "%d", port);
 194                 result = getaddrinfo (host, port_str, &hints, &res);
 195
 196                 if (result != 0) {
 197                         printf ("%s\n", gai_strerror (result));
 198                         return STATE_UNKNOWN;
 199                 }
 200
 201                 r = res;
 202                 while (r) {
 203                         /* attempt to create a socket */
 204                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 205
 206                         if (*sd < 0) {
 207                                 printf ("%s\n", _("Socket creation failed"));
 208                                 freeaddrinfo (r);
 209                                 return STATE_UNKNOWN;
 210                         }
 211
 212                         /* attempt to open a connection */
 213                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 214
 215                         if (result == 0) {
 216                                 was_refused = FALSE;
 217                                 break;
 218                         }
 219
 220                         if (result < 0) {
 221                                 switch (errno) {
 222                                 case ECONNREFUSED:
 223                                         was_refused = TRUE;
 224                                         break;
 225                                 }
 226                         }
 227
 228                         close (*sd);
 229                         r = r->ai_next;
 230                 }
 231                 freeaddrinfo (res);
 232         }
 233         /* else the hostname is interpreted as a path to a unix socket */
 234         else {
 235                 if(strlen(host_name) >= UNIX_PATH_MAX){
 236                         die(STATE_UNKNOWN, _("Supplied path too long unix domain socket"));
 237                 }
 238                 memset(&su, 0, sizeof(su));
 239                 su.sun_family = AF_UNIX;
 240                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 241                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 242                 if(*sd < 0){
 243                         die(STATE_UNKNOWN, _("Socket creation failed"));
 244                 }
 245                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 246                 if (result < 0 && errno == ECONNREFUSED)
 247                         was_refused = TRUE;
 248         }
 249
 250         if (result == 0)
 251                 return STATE_OK;
 252         else if (was_refused) {
 253                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 254                 case STATE_OK:
 255                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 256                         return econn_refuse_state;
 257                         break;
 258                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 259                         printf ("%s\n", strerror(errno));
 260                         return econn_refuse_state;
 261                         break;
 262                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 263                         return STATE_UNKNOWN;
 264                         break;
 265                 }
 266         }
 267         else {
 268                 printf ("%s\n", strerror(errno));
 269                 return STATE_CRITICAL;
 270         }
 271 }
 272
 273 int
 274 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 275 {
 276         int result = STATE_OK;
 277         int send_result;
 278         int recv_result;
 279         struct timeval tv;
 280         fd_set readfds;
 281
 282         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 283         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 284                 printf ("%s\n", _("Send failed"));
 285                 result = STATE_WARNING;
 286         }
 287
 288         /* wait up to the number of seconds for socket timeout minus one
 289            for data from the host */
 290         tv.tv_sec = socket_timeout - 1;
 291         tv.tv_usec = 0;
 292         FD_ZERO (&readfds);
 293         FD_SET (sd, &readfds);
 294         select (sd + 1, &readfds, NULL, NULL, &tv);
 295
 296         /* make sure some data has arrived */
 297         if (!FD_ISSET (sd, &readfds)) {
 298                 strcpy (recv_buffer, "");
 299                 printf ("%s\n", _("No data was received from host!"));
 300                 result = STATE_WARNING;
 301         }
 302
 303         else {
 304                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 305                 if (recv_result == -1) {
 306                         strcpy (recv_buffer, "");
 307                         if (proto != IPPROTO_TCP)
 308                                 printf ("%s\n", _("Receive failed"));
 309                         result = STATE_WARNING;
 310                 }
 311                 else
 312                         recv_buffer[recv_result] = 0;
 313
 314                 /* die returned string */
 315                 recv_buffer[recv_size - 1] = 0;
 316         }
 317         return result;
 318 }
 319
 320
 321 int
 322 is_host (const char *address)
 323 {
 324         if (is_addr (address) || is_hostname (address))
 325                 return (TRUE);
 326
 327         return (FALSE);
 328 }
 329
 330 void
 331 host_or_die(const char *str)
 332 {
 333         if(!str || (!is_addr(str) && !is_hostname(str)))
 334                 usage_va(_("Invalid hostname/address - %s"), str);
 335 }
 336
 337 int
 338 is_addr (const char *address)
 339 {
 340 #ifdef USE_IPV6
 341         if (address_family == AF_INET && is_inet_addr (address))
 342                 return TRUE;
 343         else if (address_family == AF_INET6 && is_inet6_addr (address))
 344                 return TRUE;
 345 #else
 346         if (is_inet_addr (address))
 347                 return (TRUE);
 348 #endif
 349
 350         return (FALSE);
 351 }
 352
 353 int
 354 resolve_host_or_addr (const char *address, int family)
 355 {
 356         struct addrinfo hints;
 357         struct addrinfo *res;
 358         int retval;
 359
 360         memset (&hints, 0, sizeof (hints));
 361         hints.ai_family = family;
 362         retval = getaddrinfo (address, NULL, &hints, &res);
 363
 364         if (retval != 0)
 365                 return FALSE;
 366         else {
 367                 freeaddrinfo (res);
 368                 return TRUE;
 369         }
 370 }