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 * 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 #define LOCAL_TIMEOUT_ALARM_HANDLER
  31
  32 #include "common.h"
  33 #include "netutils.h"
  34
  35 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  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 (_("CRITICAL - Socket timeout after %d seconds\n"), socket_timeout);
  50         else
  51                 printf (_("CRITICAL - Abnormal timeout after %d seconds\n"), socket_timeout);
  52
  53         exit (STATE_CRITICAL);
  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         struct addrinfo hints;
 165         struct addrinfo *r, *res;
 166         struct sockaddr_un su;
 167         char port_str[6], host[MAX_HOST_ADDRESS_LENGTH];
 168         size_t len;
 169         int socktype, result;
 170
 171         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 172
 173         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 174         if(host_name[0] != '/'){
 175                 memset (&hints, 0, sizeof (hints));
 176                 hints.ai_family = address_family;
 177                 hints.ai_protocol = proto;
 178                 hints.ai_socktype = socktype;
 179
 180                 len = strlen (host_name);
 181                 /* check for an [IPv6] address (and strip the brackets) */
 182                 if (len >= 2 && host_name[0] == '[' && host_name[len - 1] == ']') {
 183                         host_name++;
 184                         len -= 2;
 185                 }
 186                 if (len >= sizeof(host))
 187                         return STATE_UNKNOWN;
 188                 memcpy (host, host_name, len);
 189                 host[len] = '\0';
 190                 snprintf (port_str, sizeof (port_str), "%d", port);
 191                 result = getaddrinfo (host, port_str, &hints, &res);
 192
 193                 if (result != 0) {
 194                         printf ("%s\n", gai_strerror (result));
 195                         return STATE_UNKNOWN;
 196                 }
 197
 198                 r = res;
 199                 while (r) {
 200                         /* attempt to create a socket */
 201                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 202
 203                         if (*sd < 0) {
 204                                 printf ("%s\n", _("Socket creation failed"));
 205                                 freeaddrinfo (r);
 206                                 return STATE_UNKNOWN;
 207                         }
 208
 209                         /* attempt to open a connection */
 210                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 211
 212                         if (result == 0) {
 213                                 was_refused = FALSE;
 214                                 break;
 215                         }
 216
 217                         if (result < 0) {
 218                                 switch (errno) {
 219                                 case ECONNREFUSED:
 220                                         was_refused = TRUE;
 221                                         break;
 222                                 }
 223                         }
 224
 225                         close (*sd);
 226                         r = r->ai_next;
 227                 }
 228                 freeaddrinfo (res);
 229         }
 230         /* else the hostname is interpreted as a path to a unix socket */
 231         else {
 232                 if(strlen(host_name) >= UNIX_PATH_MAX){
 233                         die(STATE_UNKNOWN, _("Supplied path too long unix domain socket"));
 234                 }
 235                 memset(&su, 0, sizeof(su));
 236                 su.sun_family = AF_UNIX;
 237                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 238                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 239                 if(*sd < 0){
 240                         die(STATE_UNKNOWN, _("Socket creation failed"));
 241                 }
 242                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 243                 if (result < 0 && errno == ECONNREFUSED)
 244                         was_refused = TRUE;
 245         }
 246
 247         if (result == 0)
 248                 return STATE_OK;
 249         else if (was_refused) {
 250                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 251                 case STATE_OK:
 252                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 253                         return econn_refuse_state;
 254                         break;
 255                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 256                         printf ("%s\n", strerror(errno));
 257                         return econn_refuse_state;
 258                         break;
 259                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 260                         return STATE_UNKNOWN;
 261                         break;
 262                 }
 263         }
 264         else {
 265                 printf ("%s\n", strerror(errno));
 266                 return STATE_CRITICAL;
 267         }
 268 }
 269
 270 int
 271 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 272 {
 273         int result = STATE_OK;
 274         int send_result;
 275         int recv_result;
 276         struct timeval tv;
 277         fd_set readfds;
 278
 279         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 280         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 281                 printf ("%s\n", _("Send failed"));
 282                 result = STATE_WARNING;
 283         }
 284
 285         /* wait up to the number of seconds for socket timeout minus one
 286            for data from the host */
 287         tv.tv_sec = socket_timeout - 1;
 288         tv.tv_usec = 0;
 289         FD_ZERO (&readfds);
 290         FD_SET (sd, &readfds);
 291         select (sd + 1, &readfds, NULL, NULL, &tv);
 292
 293         /* make sure some data has arrived */
 294         if (!FD_ISSET (sd, &readfds)) {
 295                 strcpy (recv_buffer, "");
 296                 printf ("%s\n", _("No data was received from host!"));
 297                 result = STATE_WARNING;
 298         }
 299
 300         else {
 301                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 302                 if (recv_result == -1) {
 303                         strcpy (recv_buffer, "");
 304                         if (proto != IPPROTO_TCP)
 305                                 printf ("%s\n", _("Receive failed"));
 306                         result = STATE_WARNING;
 307                 }
 308                 else
 309                         recv_buffer[recv_result] = 0;
 310
 311                 /* die returned string */
 312                 recv_buffer[recv_size - 1] = 0;
 313         }
 314         return result;
 315 }
 316
 317
 318 int
 319 is_host (const char *address)
 320 {
 321         if (is_addr (address) || is_hostname (address))
 322                 return (TRUE);
 323
 324         return (FALSE);
 325 }
 326
 327 void
 328 host_or_die(const char *str)
 329 {
 330         if(!str || (!is_addr(str) && !is_hostname(str)))
 331                 usage_va(_("Invalid hostname/address - %s"), str);
 332 }
 333
 334 int
 335 is_addr (const char *address)
 336 {
 337 #ifdef USE_IPV6
 338         if (address_family == AF_INET && is_inet_addr (address))
 339                 return TRUE;
 340         else if (address_family == AF_INET6 && is_inet6_addr (address))
 341                 return TRUE;
 342 #else
 343         if (is_inet_addr (address))
 344                 return (TRUE);
 345 #endif
 346
 347         return (FALSE);
 348 }
 349
 350 int
 351 resolve_host_or_addr (const char *address, int family)
 352 {
 353         struct addrinfo hints;
 354         struct addrinfo *res;
 355         int retval;
 356
 357         memset (&hints, 0, sizeof (hints));
 358         hints.ai_family = family;
 359         retval = getaddrinfo (address, NULL, &hints, &res);
 360
 361         if (retval != 0)
 362                 return FALSE;
 363         else {
 364                 freeaddrinfo (res);
 365                 return TRUE;
 366         }
 367 }