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