plugins/netutils.c

   1 /*****************************************************************************
   2 *
   3 * Monitoring Plugins network utilities
   4 *
   5 * License: GPL
   6 * Copyright (c) 1999 Ethan Galstad (nagios@nagios.org)
   7 * Copyright (c) 2003-2008 Monitoring Plugins Development Team
   8 *
   9 * Description:
  10 *
  11 * This file contains commons functions used in many of the plugins.
  12 *
  13 *
  14 * This program is free software: you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation, either version 3 of the License, or
  17 * (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 *
  24 * You should have received a copy of the GNU General Public License
  25 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  26 *
  27 *
  28 *****************************************************************************/
  29
  30 #include "common.h"
  31 #include "netutils.h"
  32
  33 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  34 unsigned int socket_timeout_state = STATE_CRITICAL;
  35
  36 int econn_refuse_state = STATE_CRITICAL;
  37 int was_refused = FALSE;
  38 #if USE_IPV6
  39 int address_family = AF_UNSPEC;
  40 #else
  41 int address_family = AF_INET;
  42 #endif
  43
  44 /* handles socket timeouts */
  45 void
  46 socket_timeout_alarm_handler (int sig)
  47 {
  48         if (sig == SIGALRM)
  49                 printf (_("%s - Socket timeout after %d seconds\n"), state_text(socket_timeout_state),  socket_timeout);
  50         else
  51                 printf (_("%s - Abnormal timeout after %d seconds\n"), state_text(socket_timeout_state), socket_timeout);
  52
  53         exit (socket_timeout_state);
  54 }
  55
  56
  57 /* connects to a host on a specified tcp port, sends a string, and gets a
  58          response. loops on select-recv until timeout or eof to get all of a
  59          multi-packet answer */
  60 int
  61 process_tcp_request2 (const char *server_address, int server_port,
  62         const char *send_buffer, char *recv_buffer, int recv_size)
  63 {
  64
  65         int result;
  66         int send_result;
  67         int recv_result;
  68         int sd;
  69         struct timeval tv;
  70         fd_set readfds;
  71         int recv_length = 0;
  72
  73         result = np_net_connect (server_address, server_port, &sd, IPPROTO_TCP);
  74         if (result != STATE_OK)
  75                 return STATE_CRITICAL;
  76
  77         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
  78         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
  79                 printf ("%s\n", _("Send failed"));
  80                 result = STATE_WARNING;
  81         }
  82
  83         while (1) {
  84                 /* wait up to the number of seconds for socket timeout
  85                    minus one for data from the host */
  86                 tv.tv_sec = socket_timeout - 1;
  87                 tv.tv_usec = 0;
  88                 FD_ZERO (&readfds);
  89                 FD_SET (sd, &readfds);
  90                 select (sd + 1, &readfds, NULL, NULL, &tv);
  91
  92                 /* make sure some data has arrived */
  93                 if (!FD_ISSET (sd, &readfds)) { /* it hasn't */
  94                         if (!recv_length) {
  95                                 strcpy (recv_buffer, "");
  96                                 printf ("%s\n", _("No data was received from host!"));
  97                                 result = STATE_WARNING;
  98                         }
  99                         else {                                                                          /* this one failed, but previous ones worked */
 100                                 recv_buffer[recv_length] = 0;
 101                         }
 102                         break;
 103                 }
 104                 else {                                                                                  /* it has */
 105                         recv_result =
 106                                 recv (sd, recv_buffer + recv_length,
 107                                         (size_t)recv_size - recv_length - 1, 0);
 108                         if (recv_result == -1) {
 109                                 /* recv failed, bail out */
 110                                 strcpy (recv_buffer + recv_length, "");
 111                                 result = STATE_WARNING;
 112                                 break;
 113                         }
 114                         else if (recv_result == 0) {
 115                                 /* end of file ? */
 116                                 recv_buffer[recv_length] = 0;
 117                                 break;
 118                         }
 119                         else {                                                                          /* we got data! */
 120                                 recv_length += recv_result;
 121                                 if (recv_length >= recv_size - 1) {
 122                                         /* buffer full, we're done */
 123                                         recv_buffer[recv_size - 1] = 0;
 124                                         break;
 125                                 }
 126                         }
 127                 }
 128                 /* end if(!FD_ISSET(sd,&readfds)) */
 129         }
 130         /* end while(1) */
 131
 132         close (sd);
 133         return result;
 134 }
 135
 136
 137 /* connects to a host on a specified port, sends a string, and gets a
 138    response */
 139 int
 140 process_request (const char *server_address, int server_port, int proto,
 141         const char *send_buffer, char *recv_buffer, int recv_size)
 142 {
 143         int result;
 144         int sd;
 145
 146         result = STATE_OK;
 147
 148         result = np_net_connect (server_address, server_port, &sd, proto);
 149         if (result != STATE_OK)
 150                 return STATE_CRITICAL;
 151
 152         result = send_request (sd, proto, send_buffer, recv_buffer, recv_size);
 153
 154         close (sd);
 155
 156         return result;
 157 }
 158
 159
 160 /* opens a tcp or udp connection to a remote host or local socket */
 161 int
 162 np_net_connect (const char *host_name, int port, int *sd, int proto)
 163 {
 164         /* send back STATE_UNKOWN if there's an error
 165            send back STATE_OK if we connect
 166            send back STATE_CRITICAL if we can't connect.
 167            Let upstream figure out what to send to the user. */
 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         short is_socket = (host_name[0] == '/');
 175
 176         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 177
 178         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 179         if (!is_socket){
 180                 memset (&hints, 0, sizeof (hints));
 181                 hints.ai_family = address_family;
 182                 hints.ai_protocol = proto;
 183                 hints.ai_socktype = socktype;
 184
 185                 len = strlen (host_name);
 186                 /* check for an [IPv6] address (and strip the brackets) */
 187                 if (len >= 2 && host_name[0] == '[' && host_name[len - 1] == ']') {
 188                         host_name++;
 189                         len -= 2;
 190                 }
 191                 if (len >= sizeof(host))
 192                         return STATE_UNKNOWN;
 193                 memcpy (host, host_name, len);
 194                 host[len] = '\0';
 195                 snprintf (port_str, sizeof (port_str), "%d", port);
 196                 result = getaddrinfo (host, port_str, &hints, &res);
 197
 198                 if (result != 0) {
 199                         printf ("%s\n", gai_strerror (result));
 200                         return STATE_UNKNOWN;
 201                 }
 202
 203                 r = res;
 204                 while (r) {
 205                         /* attempt to create a socket */
 206                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 207
 208                         if (*sd < 0) {
 209                                 printf ("%s\n", _("Socket creation failed"));
 210                                 freeaddrinfo (r);
 211                                 return STATE_UNKNOWN;
 212                         }
 213
 214                         /* attempt to open a connection */
 215                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 216
 217                         if (result == 0) {
 218                                 was_refused = FALSE;
 219                                 break;
 220                         }
 221
 222                         if (result < 0) {
 223                                 switch (errno) {
 224                                 case ECONNREFUSED:
 225                                         was_refused = TRUE;
 226                                         break;
 227                                 }
 228                         }
 229
 230                         close (*sd);
 231                         r = r->ai_next;
 232                 }
 233                 freeaddrinfo (res);
 234         }
 235         /* else the hostname is interpreted as a path to a unix socket */
 236         else {
 237                 if(strlen(host_name) >= UNIX_PATH_MAX){
 238                         die(STATE_UNKNOWN, _("Supplied path too long unix domain socket"));
 239                 }
 240                 memset(&su, 0, sizeof(su));
 241                 su.sun_family = AF_UNIX;
 242                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 243                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 244                 if(*sd < 0){
 245                         die(STATE_UNKNOWN, _("Socket creation failed"));
 246                 }
 247                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 248                 if (result < 0 && errno == ECONNREFUSED)
 249                         was_refused = TRUE;
 250         }
 251
 252         if (result == 0)
 253                 return STATE_OK;
 254         else if (was_refused) {
 255                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 256                 case STATE_OK:
 257                 case STATE_WARNING:  /* user wants WARN or OK on refusal, or... */
 258                 case STATE_CRITICAL: /* user did not set econn_refuse_state, or wanted critical */
 259                         if (is_socket)
 260                                 printf("connect to file socket %s: %s\n", host_name, strerror(errno));
 261                         else
 262                                 printf("connect to address %s and port %d: %s\n",
 263                                        host_name, port, strerror(errno));
 264                         return STATE_CRITICAL;
 265                         break;
 266                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 267                         return STATE_UNKNOWN;
 268                         break;
 269                 }
 270         }
 271         else {
 272                 if (is_socket)
 273                         printf("connect to file socket %s: %s\n", host_name, strerror(errno));
 274                 else
 275                         printf("connect to address %s and port %d: %s\n",
 276                                host_name, port, strerror(errno));
 277                 return STATE_CRITICAL;
 278         }
 279 }
 280
 281 int
 282 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 283 {
 284         int result = STATE_OK;
 285         int send_result;
 286         int recv_result;
 287         struct timeval tv;
 288         fd_set readfds;
 289
 290         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 291         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 292                 printf ("%s\n", _("Send failed"));
 293                 result = STATE_WARNING;
 294         }
 295
 296         /* wait up to the number of seconds for socket timeout minus one
 297            for data from the host */
 298         tv.tv_sec = socket_timeout - 1;
 299         tv.tv_usec = 0;
 300         FD_ZERO (&readfds);
 301         FD_SET (sd, &readfds);
 302         select (sd + 1, &readfds, NULL, NULL, &tv);
 303
 304         /* make sure some data has arrived */
 305         if (!FD_ISSET (sd, &readfds)) {
 306                 strcpy (recv_buffer, "");
 307                 printf ("%s\n", _("No data was received from host!"));
 308                 result = STATE_WARNING;
 309         }
 310
 311         else {
 312                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 313                 if (recv_result == -1) {
 314                         strcpy (recv_buffer, "");
 315                         if (proto != IPPROTO_TCP)
 316                                 printf ("%s\n", _("Receive failed"));
 317                         result = STATE_WARNING;
 318                 }
 319                 else
 320                         recv_buffer[recv_result] = 0;
 321
 322                 /* die returned string */
 323                 recv_buffer[recv_size - 1] = 0;
 324         }
 325         return result;
 326 }
 327
 328
 329 int
 330 is_host (const char *address)
 331 {
 332         if (is_addr (address) || is_hostname (address))
 333                 return (TRUE);
 334
 335         return (FALSE);
 336 }
 337
 338 void
 339 host_or_die(const char *str)
 340 {
 341         if(!str || (!is_addr(str) && !is_hostname(str)))
 342                 usage_va(_("Invalid hostname/address - %s"), str);
 343 }
 344
 345 int
 346 is_addr (const char *address)
 347 {
 348 #ifdef USE_IPV6
 349         if (address_family == AF_INET && is_inet_addr (address))
 350                 return TRUE;
 351         else if (address_family == AF_INET6 && is_inet6_addr (address))
 352                 return TRUE;
 353 #else
 354         if (is_inet_addr (address))
 355                 return (TRUE);
 356 #endif
 357
 358         return (FALSE);
 359 }
 360
 361 int
 362 dns_lookup (const char *in, struct sockaddr_storage *ss, int family)
 363 {
 364         struct addrinfo hints;
 365         struct addrinfo *res;
 366         int retval;
 367
 368         memset (&hints, 0, sizeof(struct addrinfo));
 369         hints.ai_family = family;
 370
 371         retval = getaddrinfo (in, NULL, &hints, &res);
 372         if (retval != 0)
 373                 return FALSE;
 374
 375         if (ss != NULL)
 376                 memcpy (ss, res->ai_addr, res->ai_addrlen);
 377         freeaddrinfo (res);
 378         return TRUE;
 379 }