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 #define LOCAL_TIMEOUT_ALARM_HANDLER
  35
  36 #include "common.h"
  37 #include "netutils.h"
  38
  39 unsigned int socket_timeout = DEFAULT_SOCKET_TIMEOUT;
  40 int econn_refuse_state = STATE_CRITICAL;
  41 int was_refused = FALSE;
  42 int address_family = AF_UNSPEC;
  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];
 168         int socktype, result;
 169
 170         socktype = (proto == IPPROTO_UDP) ? SOCK_DGRAM : SOCK_STREAM;
 171
 172         /* as long as it doesn't start with a '/', it's assumed a host or ip */
 173         if(host_name[0] != '/'){
 174                 memset (&hints, 0, sizeof (hints));
 175                 hints.ai_family = address_family;
 176                 hints.ai_protocol = proto;
 177                 hints.ai_socktype = socktype;
 178
 179                 snprintf (port_str, sizeof (port_str), "%d", port);
 180                 result = getaddrinfo (host_name, port_str, &hints, &res);
 181
 182                 if (result != 0) {
 183                         printf ("%s\n", gai_strerror (result));
 184                         return STATE_UNKNOWN;
 185                 }
 186
 187                 r = res;
 188                 while (r) {
 189                         /* attempt to create a socket */
 190                         *sd = socket (r->ai_family, socktype, r->ai_protocol);
 191
 192                         if (*sd < 0) {
 193                                 printf ("%s\n", _("Socket creation failed"));
 194                                 freeaddrinfo (r);
 195                                 return STATE_UNKNOWN;
 196                         }
 197
 198                         /* attempt to open a connection */
 199                         result = connect (*sd, r->ai_addr, r->ai_addrlen);
 200
 201                         if (result == 0) {
 202                                 was_refused = FALSE;
 203                                 break;
 204                         }
 205
 206                         if (result < 0) {
 207                                 switch (errno) {
 208                                 case ECONNREFUSED:
 209                                         was_refused = TRUE;
 210                                         break;
 211                                 }
 212                         }
 213
 214                         close (*sd);
 215                         r = r->ai_next;
 216                 }
 217                 freeaddrinfo (res);
 218         }
 219         /* else the hostname is interpreted as a path to a unix socket */
 220         else {
 221                 if(strlen(host_name) >= UNIX_PATH_MAX){
 222                         die(STATE_UNKNOWN, _("Supplied path too long unix domain socket"));
 223                 }
 224                 memset(&su, 0, sizeof(su));
 225                 su.sun_family = AF_UNIX;
 226                 strncpy(su.sun_path, host_name, UNIX_PATH_MAX);
 227                 *sd = socket(PF_UNIX, SOCK_STREAM, 0);
 228                 if(sd < 0){
 229                         die(STATE_UNKNOWN, _("Socket creation failed"));
 230                 }
 231                 result = connect(*sd, (struct sockaddr *)&su, sizeof(su));
 232                 if (result < 0 && errno == ECONNREFUSED)
 233                         was_refused = TRUE;
 234         }
 235
 236         if (result == 0)
 237                 return STATE_OK;
 238         else if (was_refused) {
 239                 switch (econn_refuse_state) { /* a user-defined expected outcome */
 240                 case STATE_OK:
 241                 case STATE_WARNING:  /* user wants WARN or OK on refusal */
 242                         return econn_refuse_state;
 243                         break;
 244                 case STATE_CRITICAL: /* user did not set econn_refuse_state */
 245                         printf ("%s\n", strerror(errno));
 246                         return econn_refuse_state;
 247                         break;
 248                 default: /* it's a logic error if we do not end up in STATE_(OK|WARNING|CRITICAL) */
 249                         return STATE_UNKNOWN;
 250                         break;
 251                 }
 252         }
 253         else {
 254                 printf ("%s\n", strerror(errno));
 255                 return STATE_CRITICAL;
 256         }
 257 }
 258
 259 int
 260 send_request (int sd, int proto, const char *send_buffer, char *recv_buffer, int recv_size)
 261 {
 262         int result = STATE_OK;
 263         int send_result;
 264         int recv_result;
 265         struct timeval tv;
 266         fd_set readfds;
 267
 268         send_result = send (sd, send_buffer, strlen (send_buffer), 0);
 269         if (send_result<0 || (size_t)send_result!=strlen(send_buffer)) {
 270                 printf ("%s\n", _("Send failed"));
 271                 result = STATE_WARNING;
 272         }
 273
 274         /* wait up to the number of seconds for socket timeout minus one
 275            for data from the host */
 276         tv.tv_sec = socket_timeout - 1;
 277         tv.tv_usec = 0;
 278         FD_ZERO (&readfds);
 279         FD_SET (sd, &readfds);
 280         select (sd + 1, &readfds, NULL, NULL, &tv);
 281
 282         /* make sure some data has arrived */
 283         if (!FD_ISSET (sd, &readfds)) {
 284                 strcpy (recv_buffer, "");
 285                 printf ("%s\n", _("No data was received from host!"));
 286                 result = STATE_WARNING;
 287         }
 288
 289         else {
 290                 recv_result = recv (sd, recv_buffer, (size_t)recv_size - 1, 0);
 291                 if (recv_result == -1) {
 292                         strcpy (recv_buffer, "");
 293                         if (proto != IPPROTO_TCP)
 294                                 printf ("%s\n", _("Receive failed"));
 295                         result = STATE_WARNING;
 296                 }
 297                 else
 298                         recv_buffer[recv_result] = 0;
 299
 300                 /* die returned string */
 301                 recv_buffer[recv_size - 1] = 0;
 302         }
 303         return result;
 304 }
 305
 306
 307 int
 308 is_host (const char *address)
 309 {
 310         if (is_addr (address) || is_hostname (address))
 311                 return (TRUE);
 312
 313         return (FALSE);
 314 }
 315
 316 void
 317 host_or_die(const char *str)
 318 {
 319         if(!str || (!is_addr(str) && !is_hostname(str)))
 320                 usage_va(_("Invalid hostname/address - %s"), str);
 321 }
 322
 323 int
 324 is_addr (const char *address)
 325 {
 326 #ifdef USE_IPV6
 327         if (address_family == AF_INET && is_inet_addr (address))
 328                 return TRUE;
 329         else if (address_family == AF_INET6 && is_inet6_addr (address))
 330                 return TRUE;
 331 #else
 332         if (is_inet_addr (address))
 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 }