src/write_http.c

   1 /**
   2  * collectd - src/write_http.c
   3  * Copyright (C) 2009       Paul Sadauskas
   4  * Copyright (C) 2009       Doug MacEachern
   5  * Copyright (C) 2007-2014  Florian octo Forster
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; only version 2 of the License is applicable.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  *
  20  * Authors:
  21  *   Florian octo Forster <octo at collectd.org>
  22  *   Doug MacEachern <dougm@hyperic.com>
  23  *   Paul Sadauskas <psadauskas@gmail.com>
  24  **/
  25
  26 #include "collectd.h"
  27 #include "plugin.h"
  28 #include "common.h"
  29 #include "utils_cache.h"
  30 #include "utils_format_json.h"
  31
  32 #if HAVE_PTHREAD_H
  33 # include <pthread.h>
  34 #endif
  35
  36 #include <curl/curl.h>
  37
  38 #ifndef WRITE_HTTP_DEFAULT_BUFFER_SIZE
  39 # define WRITE_HTTP_DEFAULT_BUFFER_SIZE 4096
  40 #endif
  41
  42 #define WH_DEFAULT_LOW_LIMIT_BYTES_PER_SEC 100
  43 /*
  44  * Private variables
  45  */
  46 struct wh_callback_s
  47 {
  48         char *location;
  49
  50         char *user;
  51         char *pass;
  52         char *credentials;
  53         _Bool verify_peer;
  54         _Bool verify_host;
  55         char *cacert;
  56         char *capath;
  57         char *clientkey;
  58         char *clientcert;
  59         char *clientkeypass;
  60         long sslversion;
  61         _Bool store_rates;
  62         _Bool abort_on_slow;
  63         int   low_limit_bytes;
  64         time_t interval;
  65         int post_timeout;
  66
  67 #define WH_FORMAT_COMMAND 0
  68 #define WH_FORMAT_JSON    1
  69         int format;
  70
  71         CURL *curl;
  72         char curl_errbuf[CURL_ERROR_SIZE];
  73
  74         char  *send_buffer;
  75         size_t send_buffer_size;
  76         size_t send_buffer_free;
  77         size_t send_buffer_fill;
  78         cdtime_t send_buffer_init_time;
  79
  80         pthread_mutex_t send_lock;
  81 };
  82 typedef struct wh_callback_s wh_callback_t;
  83
  84 static void wh_reset_buffer (wh_callback_t *cb)  /* {{{ */
  85 {
  86         memset (cb->send_buffer, 0, cb->send_buffer_size);
  87         cb->send_buffer_free = cb->send_buffer_size;
  88         cb->send_buffer_fill = 0;
  89         cb->send_buffer_init_time = cdtime ();
  90
  91         if (cb->format == WH_FORMAT_JSON)
  92         {
  93                 format_json_initialize (cb->send_buffer,
  94                                 &cb->send_buffer_fill,
  95                                 &cb->send_buffer_free);
  96         }
  97 } /* }}} wh_reset_buffer */
  98
  99 static int wh_send_buffer (wh_callback_t *cb) /* {{{ */
 100 {
 101         int status = 0;
 102
 103         curl_easy_setopt (cb->curl, CURLOPT_POSTFIELDS, cb->send_buffer);
 104         status = curl_easy_perform (cb->curl);
 105         if (status != CURLE_OK)
 106         {
 107                 ERROR ("write_http plugin: curl_easy_perform failed with "
 108                                 "status %i: %s",
 109                                 status, cb->curl_errbuf);
 110         }
 111         return (status);
 112 } /* }}} wh_send_buffer */
 113
 114 static int wh_callback_init (wh_callback_t *cb) /* {{{ */
 115 {
 116         struct curl_slist *headers;
 117
 118         if (cb->curl != NULL)
 119                 return (0);
 120
 121         cb->curl = curl_easy_init ();
 122         if (cb->curl == NULL)
 123         {
 124                 ERROR ("curl plugin: curl_easy_init failed.");
 125                 return (-1);
 126         }
 127
 128         if(cb->abort_on_slow && cb->interval > 0)
 129         {
 130             curl_easy_setopt(cb->curl, CURLOPT_LOW_SPEED_LIMIT, (cb->low_limit_bytes?cb->low_limit_bytes:WH_DEFAULT_LOW_LIMIT_BYTES_PER_SEC));
 131             curl_easy_setopt(cb->curl, CURLOPT_LOW_SPEED_TIME, cb->interval);
 132         }
 133         if(cb->post_timeout >0)
 134         {
 135            curl_easy_setopt(cb->curl, CURLOPT_TIMEOUT, cb->post_timeout);
 136         }
 137
 138         curl_easy_setopt (cb->curl, CURLOPT_NOSIGNAL, 1L);
 139         curl_easy_setopt (cb->curl, CURLOPT_USERAGENT, COLLECTD_USERAGENT);
 140
 141         headers = NULL;
 142         headers = curl_slist_append (headers, "Accept:  */*");
 143         if (cb->format == WH_FORMAT_JSON)
 144                 headers = curl_slist_append (headers, "Content-Type: application/json");
 145         else
 146                 headers = curl_slist_append (headers, "Content-Type: text/plain");
 147         headers = curl_slist_append (headers, "Expect:");
 148         curl_easy_setopt (cb->curl, CURLOPT_HTTPHEADER, headers);
 149
 150         curl_easy_setopt (cb->curl, CURLOPT_ERRORBUFFER, cb->curl_errbuf);
 151         curl_easy_setopt (cb->curl, CURLOPT_URL, cb->location);
 152
 153         if (cb->user != NULL)
 154         {
 155                 size_t credentials_size;
 156
 157                 credentials_size = strlen (cb->user) + 2;
 158                 if (cb->pass != NULL)
 159                         credentials_size += strlen (cb->pass);
 160
 161                 cb->credentials = (char *) malloc (credentials_size);
 162                 if (cb->credentials == NULL)
 163                 {
 164                         ERROR ("curl plugin: malloc failed.");
 165                         return (-1);
 166                 }
 167
 168                 ssnprintf (cb->credentials, credentials_size, "%s:%s",
 169                                 cb->user, (cb->pass == NULL) ? "" : cb->pass);
 170                 curl_easy_setopt (cb->curl, CURLOPT_USERPWD, cb->credentials);
 171                 curl_easy_setopt (cb->curl, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 172         }
 173
 174         curl_easy_setopt (cb->curl, CURLOPT_SSL_VERIFYPEER, (long) cb->verify_peer);
 175         curl_easy_setopt (cb->curl, CURLOPT_SSL_VERIFYHOST,
 176                         cb->verify_host ? 2L : 0L);
 177         curl_easy_setopt (cb->curl, CURLOPT_SSLVERSION, cb->sslversion);
 178         if (cb->cacert != NULL)
 179                 curl_easy_setopt (cb->curl, CURLOPT_CAINFO, cb->cacert);
 180         if (cb->capath != NULL)
 181                 curl_easy_setopt (cb->curl, CURLOPT_CAPATH, cb->capath);
 182
 183         if (cb->clientkey != NULL && cb->clientcert != NULL)
 184         {
 185             curl_easy_setopt (cb->curl, CURLOPT_SSLKEY, cb->clientkey);
 186             curl_easy_setopt (cb->curl, CURLOPT_SSLCERT, cb->clientcert);
 187
 188             if (cb->clientkeypass != NULL)
 189                 curl_easy_setopt (cb->curl, CURLOPT_SSLKEYPASSWD, cb->clientkeypass);
 190         }
 191
 192         wh_reset_buffer (cb);
 193
 194         return (0);
 195 } /* }}} int wh_callback_init */
 196
 197 static int wh_flush_nolock (cdtime_t timeout, wh_callback_t *cb) /* {{{ */
 198 {
 199         int status;
 200
 201         DEBUG ("write_http plugin: wh_flush_nolock: timeout = %.3f; "
 202                         "send_buffer_fill = %zu;",
 203                         CDTIME_T_TO_DOUBLE (timeout),
 204                         cb->send_buffer_fill);
 205
 206         /* timeout == 0  => flush unconditionally */
 207         if (timeout > 0)
 208         {
 209                 cdtime_t now;
 210
 211                 now = cdtime ();
 212                 if ((cb->send_buffer_init_time + timeout) > now)
 213                         return (0);
 214         }
 215
 216         if (cb->format == WH_FORMAT_COMMAND)
 217         {
 218                 if (cb->send_buffer_fill <= 0)
 219                 {
 220                         cb->send_buffer_init_time = cdtime ();
 221                         return (0);
 222                 }
 223
 224                 status = wh_send_buffer (cb);
 225                 wh_reset_buffer (cb);
 226         }
 227         else if (cb->format == WH_FORMAT_JSON)
 228         {
 229                 if (cb->send_buffer_fill <= 2)
 230                 {
 231                         cb->send_buffer_init_time = cdtime ();
 232                         return (0);
 233                 }
 234
 235                 status = format_json_finalize (cb->send_buffer,
 236                                 &cb->send_buffer_fill,
 237                                 &cb->send_buffer_free);
 238                 if (status != 0)
 239                 {
 240                         ERROR ("write_http: wh_flush_nolock: "
 241                                         "format_json_finalize failed.");
 242                         wh_reset_buffer (cb);
 243                         return (status);
 244                 }
 245
 246                 status = wh_send_buffer (cb);
 247                 wh_reset_buffer (cb);
 248         }
 249         else
 250         {
 251                 ERROR ("write_http: wh_flush_nolock: "
 252                                 "Unknown format: %i",
 253                                 cb->format);
 254                 return (-1);
 255         }
 256
 257         return (status);
 258 } /* }}} wh_flush_nolock */
 259
 260 static int wh_flush (cdtime_t timeout, /* {{{ */
 261                 const char *identifier __attribute__((unused)),
 262                 user_data_t *user_data)
 263 {
 264         wh_callback_t *cb;
 265         int status;
 266
 267         if (user_data == NULL)
 268                 return (-EINVAL);
 269
 270         cb = user_data->data;
 271
 272         pthread_mutex_lock (&cb->send_lock);
 273
 274         if (cb->curl == NULL)
 275         {
 276                 status = wh_callback_init (cb);
 277                 if (status != 0)
 278                 {
 279                         ERROR ("write_http plugin: wh_callback_init failed.");
 280                         pthread_mutex_unlock (&cb->send_lock);
 281                         return (-1);
 282                 }
 283         }
 284
 285         status = wh_flush_nolock (timeout, cb);
 286         pthread_mutex_unlock (&cb->send_lock);
 287
 288         return (status);
 289 } /* }}} int wh_flush */
 290
 291 static void wh_callback_free (void *data) /* {{{ */
 292 {
 293         wh_callback_t *cb;
 294
 295         if (data == NULL)
 296                 return;
 297
 298         cb = data;
 299
 300         wh_flush_nolock (/* timeout = */ 0, cb);
 301
 302         if (cb->curl != NULL)
 303         {
 304                 curl_easy_cleanup (cb->curl);
 305                 cb->curl = NULL;
 306         }
 307         sfree (cb->location);
 308         sfree (cb->user);
 309         sfree (cb->pass);
 310         sfree (cb->credentials);
 311         sfree (cb->cacert);
 312         sfree (cb->capath);
 313         sfree (cb->clientkey);
 314         sfree (cb->clientcert);
 315         sfree (cb->clientkeypass);
 316         sfree (cb->send_buffer);
 317
 318         sfree (cb);
 319 } /* }}} void wh_callback_free */
 320
 321 static int wh_write_command (const data_set_t *ds, const value_list_t *vl, /* {{{ */
 322                 wh_callback_t *cb)
 323 {
 324         char key[10*DATA_MAX_NAME_LEN];
 325         char values[512];
 326         char command[1024];
 327         size_t command_len;
 328
 329         int status;
 330
 331         if (0 != strcmp (ds->type, vl->type)) {
 332                 ERROR ("write_http plugin: DS type does not match "
 333                                 "value list type");
 334                 return -1;
 335         }
 336
 337         /* Copy the identifier to `key' and escape it. */
 338         status = FORMAT_VL (key, sizeof (key), vl);
 339         if (status != 0) {
 340                 ERROR ("write_http plugin: error with format_name");
 341                 return (status);
 342         }
 343         escape_string (key, sizeof (key));
 344
 345         /* Convert the values to an ASCII representation and put that into
 346          * `values'. */
 347         status = format_values (values, sizeof (values), ds, vl, cb->store_rates);
 348         if (status != 0) {
 349                 ERROR ("write_http plugin: error with "
 350                                 "wh_value_list_to_string");
 351                 return (status);
 352         }
 353
 354         command_len = (size_t) ssnprintf (command, sizeof (command),
 355                         "PUTVAL %s interval=%.3f %s\r\n",
 356                         key,
 357                         CDTIME_T_TO_DOUBLE (vl->interval),
 358                         values);
 359         if (command_len >= sizeof (command)) {
 360                 ERROR ("write_http plugin: Command buffer too small: "
 361                                 "Need %zu bytes.", command_len + 1);
 362                 return (-1);
 363         }
 364
 365         pthread_mutex_lock (&cb->send_lock);
 366
 367         if (cb->curl == NULL)
 368         {
 369                 cb->interval = CDTIME_T_TO_TIME_T(vl->interval);
 370                 status = wh_callback_init (cb);
 371                 if (status != 0)
 372                 {
 373                         ERROR ("write_http plugin: wh_callback_init failed.");
 374                         pthread_mutex_unlock (&cb->send_lock);
 375                         return (-1);
 376                 }
 377         }
 378
 379         if (command_len >= cb->send_buffer_free)
 380         {
 381                 status = wh_flush_nolock (/* timeout = */ 0, cb);
 382                 if (status != 0)
 383                 {
 384                         pthread_mutex_unlock (&cb->send_lock);
 385                         return (status);
 386                 }
 387         }
 388         assert (command_len < cb->send_buffer_free);
 389
 390         /* `command_len + 1' because `command_len' does not include the
 391          * trailing null byte. Neither does `send_buffer_fill'. */
 392         memcpy (cb->send_buffer + cb->send_buffer_fill,
 393                         command, command_len + 1);
 394         cb->send_buffer_fill += command_len;
 395         cb->send_buffer_free -= command_len;
 396
 397         DEBUG ("write_http plugin: <%s> buffer %zu/%zu (%g%%) \"%s\"",
 398                         cb->location,
 399                         cb->send_buffer_fill, cb->send_buffer_size,
 400                         100.0 * ((double) cb->send_buffer_fill) / ((double) cb->send_buffer_size),
 401                         command);
 402
 403         /* Check if we have enough space for this command. */
 404         pthread_mutex_unlock (&cb->send_lock);
 405
 406         return (0);
 407 } /* }}} int wh_write_command */
 408
 409 static int wh_write_json (const data_set_t *ds, const value_list_t *vl, /* {{{ */
 410                 wh_callback_t *cb)
 411 {
 412         int status;
 413
 414         pthread_mutex_lock (&cb->send_lock);
 415
 416         if (cb->curl == NULL)
 417         {
 418                 cb->interval = CDTIME_T_TO_TIME_T(vl->interval);
 419
 420                 status = wh_callback_init (cb);
 421                 if (status != 0)
 422                 {
 423                         ERROR ("write_http plugin: wh_callback_init failed.");
 424                         pthread_mutex_unlock (&cb->send_lock);
 425                         return (-1);
 426                 }
 427         }
 428
 429         status = format_json_value_list (cb->send_buffer,
 430                         &cb->send_buffer_fill,
 431                         &cb->send_buffer_free,
 432                         ds, vl, cb->store_rates);
 433         if (status == (-ENOMEM))
 434         {
 435                 status = wh_flush_nolock (/* timeout = */ 0, cb);
 436                 if (status != 0)
 437                 {
 438                         wh_reset_buffer (cb);
 439                         pthread_mutex_unlock (&cb->send_lock);
 440                         return (status);
 441                 }
 442
 443                 status = format_json_value_list (cb->send_buffer,
 444                                 &cb->send_buffer_fill,
 445                                 &cb->send_buffer_free,
 446                                 ds, vl, cb->store_rates);
 447         }
 448         if (status != 0)
 449         {
 450                 pthread_mutex_unlock (&cb->send_lock);
 451                 return (status);
 452         }
 453
 454         DEBUG ("write_http plugin: <%s> buffer %zu/%zu (%g%%)",
 455                         cb->location,
 456                         cb->send_buffer_fill, cb->send_buffer_size,
 457                         100.0 * ((double) cb->send_buffer_fill) / ((double) cb->send_buffer_size));
 458
 459         /* Check if we have enough space for this command. */
 460         pthread_mutex_unlock (&cb->send_lock);
 461
 462         return (0);
 463 } /* }}} int wh_write_json */
 464
 465 static int wh_write (const data_set_t *ds, const value_list_t *vl, /* {{{ */
 466                 user_data_t *user_data)
 467 {
 468         wh_callback_t *cb;
 469         int status;
 470
 471         if (user_data == NULL)
 472                 return (-EINVAL);
 473
 474         cb = user_data->data;
 475
 476         if (cb->format == WH_FORMAT_JSON)
 477                 status = wh_write_json (ds, vl, cb);
 478         else
 479                 status = wh_write_command (ds, vl, cb);
 480
 481         return (status);
 482 } /* }}} int wh_write */
 483
 484 static int config_set_format (wh_callback_t *cb, /* {{{ */
 485                 oconfig_item_t *ci)
 486 {
 487         char *string;
 488
 489         if ((ci->values_num != 1)
 490                         || (ci->values[0].type != OCONFIG_TYPE_STRING))
 491         {
 492                 WARNING ("write_http plugin: The `%s' config option "
 493                                 "needs exactly one string argument.", ci->key);
 494                 return (-1);
 495         }
 496
 497         string = ci->values[0].value.string;
 498         if (strcasecmp ("Command", string) == 0)
 499                 cb->format = WH_FORMAT_COMMAND;
 500         else if (strcasecmp ("JSON", string) == 0)
 501                 cb->format = WH_FORMAT_JSON;
 502         else
 503         {
 504                 ERROR ("write_http plugin: Invalid format string: %s",
 505                                 string);
 506                 return (-1);
 507         }
 508
 509         return (0);
 510 } /* }}} int config_set_format */
 511
 512 static int wh_config_url (oconfig_item_t *ci) /* {{{ */
 513 {
 514         wh_callback_t *cb;
 515         int buffer_size = 0;
 516         user_data_t user_data;
 517         int i;
 518
 519         cb = malloc (sizeof (*cb));
 520         if (cb == NULL)
 521         {
 522                 ERROR ("write_http plugin: malloc failed.");
 523                 return (-1);
 524         }
 525         memset (cb, 0, sizeof (*cb));
 526         cb->verify_peer = 1;
 527         cb->verify_host = 1;
 528         cb->format = WH_FORMAT_COMMAND;
 529         cb->sslversion = CURL_SSLVERSION_DEFAULT;
 530         cb->low_limit_bytes = WH_DEFAULT_LOW_LIMIT_BYTES_PER_SEC;
 531         cb->post_timeout = 0;
 532
 533         pthread_mutex_init (&cb->send_lock, /* attr = */ NULL);
 534
 535         cf_util_get_string (ci, &cb->location);
 536         if (cb->location == NULL)
 537                 return (-1);
 538
 539         for (i = 0; i < ci->children_num; i++)
 540         {
 541                 oconfig_item_t *child = ci->children + i;
 542
 543                 if (strcasecmp ("User", child->key) == 0)
 544                         cf_util_get_string (child, &cb->user);
 545                 else if (strcasecmp ("Password", child->key) == 0)
 546                         cf_util_get_string (child, &cb->pass);
 547                 else if (strcasecmp ("VerifyPeer", child->key) == 0)
 548                         cf_util_get_boolean (child, &cb->verify_peer);
 549                 else if (strcasecmp ("VerifyHost", child->key) == 0)
 550                         cf_util_get_boolean (child, &cb->verify_host);
 551                 else if (strcasecmp ("CACert", child->key) == 0)
 552                         cf_util_get_string (child, &cb->cacert);
 553                 else if (strcasecmp ("CAPath", child->key) == 0)
 554                         cf_util_get_string (child, &cb->capath);
 555                 else if (strcasecmp ("ClientKey", child->key) == 0)
 556                         cf_util_get_string (child, &cb->clientkey);
 557                 else if (strcasecmp ("ClientCert", child->key) == 0)
 558                         cf_util_get_string (child, &cb->clientcert);
 559                 else if (strcasecmp ("ClientKeyPass", child->key) == 0)
 560                         cf_util_get_string (child, &cb->clientkeypass);
 561                 else if (strcasecmp ("SSLVersion", child->key) == 0)
 562                 {
 563                         char *value = NULL;
 564
 565                         cf_util_get_string (child, &value);
 566
 567                         if (value == NULL || strcasecmp ("default", value) == 0)
 568                                 cb->sslversion = CURL_SSLVERSION_DEFAULT;
 569                         else if (strcasecmp ("SSLv2", value) == 0)
 570                                 cb->sslversion = CURL_SSLVERSION_SSLv2;
 571                         else if (strcasecmp ("SSLv3", value) == 0)
 572                                 cb->sslversion = CURL_SSLVERSION_SSLv3;
 573                         else if (strcasecmp ("TLSv1", value) == 0)
 574                                 cb->sslversion = CURL_SSLVERSION_TLSv1;
 575 #if (LIBCURL_VERSION_MAJOR > 7) || (LIBCURL_VERSION_MAJOR == 7 && LIBCURL_VERSION_MINOR >= 34)
 576                         else if (strcasecmp ("TLSv1_0", value) == 0)
 577                                 cb->sslversion = CURL_SSLVERSION_TLSv1_0;
 578                         else if (strcasecmp ("TLSv1_1", value) == 0)
 579                                 cb->sslversion = CURL_SSLVERSION_TLSv1_1;
 580                         else if (strcasecmp ("TLSv1_2", value) == 0)
 581                                 cb->sslversion = CURL_SSLVERSION_TLSv1_2;
 582 #endif
 583                         else
 584                                 ERROR ("write_http plugin: Invalid SSLVersion "
 585                                                 "option: %s.", value);
 586
 587                         sfree(value);
 588                 }
 589                 else if (strcasecmp ("Format", child->key) == 0)
 590                         config_set_format (cb, child);
 591                 else if (strcasecmp ("StoreRates", child->key) == 0)
 592                         cf_util_get_boolean (child, &cb->store_rates);
 593                 else if (strcasecmp ("BufferSize", child->key) == 0)
 594                         cf_util_get_int (child, &buffer_size);
 595                 else if (strcasecmp ("LowSpeedLimit", child->key) == 0)
 596                         cf_util_get_boolean (child,&cb->abort_on_slow);
 597                 else if (strcasecmp ("LowLimitBytesPerSec", child->key) == 0)
 598                         cf_util_get_int (child, &cb->low_limit_bytes);
 599                 else if (strcasecmp ("PostTimeoutSec", child->key) == 0)
 600                         cf_util_get_int (child, &cb->post_timeout);
 601                 else
 602                 {
 603                         ERROR ("write_http plugin: Invalid configuration "
 604                                         "option: %s.", child->key);
 605                 }
 606         }
 607
 608         if(cb->abort_on_slow)
 609         {
 610                 cb->interval = CDTIME_T_TO_TIME_T(plugin_get_interval());
 611         }
 612         if(cb->post_timeout == 0)
 613         {
 614                 //setting default timeout to plugin interval.
 615                 cb->post_timeout = CDTIME_T_TO_TIME_T(plugin_get_interval());
 616         }
 617
 618         /* Determine send_buffer_size. */
 619         cb->send_buffer_size = WRITE_HTTP_DEFAULT_BUFFER_SIZE;
 620         if (buffer_size >= 1024)
 621                 cb->send_buffer_size = (size_t) buffer_size;
 622         else if (buffer_size != 0)
 623                 ERROR ("write_http plugin: Ignoring invalid BufferSize setting (%d).",
 624                                 buffer_size);
 625
 626         /* Allocate the buffer. */
 627         cb->send_buffer = malloc (cb->send_buffer_size);
 628         if (cb->send_buffer == NULL)
 629         {
 630                 ERROR ("write_http plugin: malloc(%zu) failed.", cb->send_buffer_size);
 631                 wh_callback_free (cb);
 632                 return (-1);
 633         }
 634         /* Nulls the buffer and sets ..._free and ..._fill. */
 635         wh_reset_buffer (cb);
 636
 637         DEBUG ("write_http: Registering write callback with URL %s",
 638                         cb->location);
 639
 640         memset (&user_data, 0, sizeof (user_data));
 641         user_data.data = cb;
 642         user_data.free_func = NULL;
 643         plugin_register_flush ("write_http", wh_flush, &user_data);
 644
 645         user_data.free_func = wh_callback_free;
 646         plugin_register_write ("write_http", wh_write, &user_data);
 647
 648         return (0);
 649 } /* }}} int wh_config_url */
 650
 651 static int wh_config (oconfig_item_t *ci) /* {{{ */
 652 {
 653         int i;
 654
 655         for (i = 0; i < ci->children_num; i++)
 656         {
 657                 oconfig_item_t *child = ci->children + i;
 658
 659                 if (strcasecmp ("URL", child->key) == 0)
 660                         wh_config_url (child);
 661                 else
 662                 {
 663                         ERROR ("write_http plugin: Invalid configuration "
 664                                         "option: %s.", child->key);
 665                 }
 666         }
 667
 668         return (0);
 669 } /* }}} int wh_config */
 670
 671 static int wh_init (void) /* {{{ */
 672 {
 673         /* Call this while collectd is still single-threaded to avoid
 674          * initialization issues in libgcrypt. */
 675         curl_global_init (CURL_GLOBAL_SSL);
 676         return (0);
 677 } /* }}} int wh_init */
 678
 679 void module_register (void) /* {{{ */
 680 {
 681         plugin_register_complex_config ("write_http", wh_config);
 682         plugin_register_init ("write_http", wh_init);
 683 } /* }}} void module_register */
 684
 685 /* vim: set fdm=marker sw=8 ts=8 tw=78 et : */