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 or local socket */
 159 int
 160 np_net_connect (const char *host_name, int port, int *sd, int proto)
 161 {
 162         struct addrinfo hints;
 163         struct addrinfo *r, *res;
 164         struct sockaddr_un su;
 165         char port_str[6];
 166         int socktype, result;
 167
 168         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 169
 170         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 171         if(host_name[0] != '/'){
 172                 memset (&hints, 0, sizeof (hints));
 173                 hints.ai_family = address_family;
 174                 hints.ai_protocol = proto;
 175                 hints.ai_socktype = socktype;
 176
 177                 snprintf (port_str, sizeof (port_str), "%d", port);
 178                 result = getaddrinfo (host_name, port_str, &hints, &res);
 179
 180                 if (result != 0) {
 181                         printf ("%s\n", gai_strerror (result));
 182                         return STATE_UNKNOWN;
 183                 }
 184
 185                 r = res;
 186                 while (r) {
 187                         /* attempt to create a socket */
 188                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 189
 190                         if (*sd < 0) {
 191                                 printf (_("Socket creation failed\n"));
 192                                 freeaddrinfo (r);
 193                                 return STATE_UNKNOWN;
 194                         }
 195
 196                         /* attempt to open a connection */
 197                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 198
 199                         if (result == 0) {
 200                                 was_refused = FALSE;
 201                                 break;
 202                         }
 203
 204                         if (result < 0) {
 205                                 switch (errno) {
 206                                 case ECONNREFUSED:
 207                                         was_refused = TRUE;
 208                                         break;
 209                                 }
 210                         }
 211
 212                         close (*sd);
 213                         r = r->ai_next;
 214                 }
 215                 freeaddrinfo (res);
 216         }
 217         /* else the hostname is interpreted as a path to a unix socket */
 218         else {
 219                 if(strlen(host_name) >= UNIX_PATH_MAX){
 220                         die(_("Supplied path too long unix domain socket"));
 221                 }
 222                 memset(&su, 0, sizeof(su));
 223                 su.sun_family = AF_UNIX;
 224                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 225                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 226                 if(sd < 0){
 227                         die(_("Socket creation failed"));
 228                 }
 229                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 230                 if (result < 0 && errno == ECONNREFUSED)
 231                         was_refused = TRUE;
 232         }
 233
 234         if (result == 0)
 235                 return STATE_OK;
 236         else if (was_refused) {
 237                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 238                 case STATE_OK:
 239                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 240                         return econn_refuse_state;
 241                         break;
 242                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 243                         printf ("%s\n", strerror(errno));
 244                         return econn_refuse_state;
 245                         break;
 246                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 247                         return STATE_UNKNOWN;
 248                         break;
 249                 }
 250         }
 251         else {
 252                 printf ("%s\n", strerror(errno));
 253                 return STATE_CRITICAL;
 254         }
 255 }
 256
 257 int
 258 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 259 {
 260         int result = STATE_OK;
 261         int send_result;
 262         int recv_result;
 263         struct timeval tv;
 264         fd_set readfds;
 265
 266         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 267         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 268                 printf (_("Send failed\n"));
 269                 result = STATE_WARNING;
 270         }
 271
 272         /* wait up to the number of seconds for socket timeout minus one
 273            for data from the host */
 274         tv.tv_sec = socket_timeout - 1;
 275         tv.tv_usec = 0;
 276         FD_ZERO (&readfds);
 277         FD_SET (sd, &readfds);
 278         select (sd + 1, &readfds, NULL, NULL, &tv);
 279
 280         /* make sure some data has arrived */
 281         if (!FD_ISSET (sd, &readfds)) {
 282                 strcpy (recv_buffer, "");
 283                 printf (_("No data was received from host!\n"));
 284                 result = STATE_WARNING;
 285         }
 286
 287         else {
 288                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 289                 if (recv_result == -1) {
 290                         strcpy (recv_buffer, "");
 291                         if (proto != IPPROTO_TCP)
 292                                 printf (_("Receive failed\n"));
 293                         result = STATE_WARNING;
 294                 }
 295                 else
 296                         recv_buffer[recv_result] = 0;
 297
 298                 /* die returned string */
 299                 recv_buffer[recv_size - 1] = 0;
 300         }
 301         return result;
 302 }
 303
 304
 305 int
 306 is_host (const char *address)
 307 {
 308         if (is_addr (address) || is_hostname (address))
 309                 return (TRUE);
 310
 311         return (FALSE);
 312 }
 313
 314 void
 315 host_or_die(const char *str)
 316 {
 317         if(!str || (!is_addr(str) && !is_hostname(str)))
 318                 usage_va(_("Invalid hostname/address - %s"), str);
 319 }
 320
 321 int
 322 is_addr (const char *address)
 323 {
 324 #ifdef USE_IPV6
 325         if (is_inet_addr (address) && address_family != AF_INET6)
 326 #else
 327         if (is_inet_addr (address))
 328 #endif
 329                 return (TRUE);
 330
 331 #ifdef USE_IPV6
 332         if (is_inet6_addr (address) && address_family != AF_INET)
 333                 return (TRUE);
 334 #endif
 335
 336         return (FALSE);
 337 }
 338
 339 int
 340 resolve_host_or_addr (const char *address, int family)
 341 {
 342         struct addrinfo hints;
 343         struct addrinfo *res;
 344         int retval;
 345
 346         memset (&hints, 0, sizeof (hints));
 347         hints.ai_family = family;
 348         retval = getaddrinfo (address, NULL, &hints, &res);
 349
 350         if (retval != 0)
 351                 return FALSE;
 352         else {
 353                 freeaddrinfo (res);
 354                 return TRUE;
 355         }
 356 }