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Diffstat (limited to 'src/exchange-lib/exchange_api_context.c')
| -rw-r--r-- | src/exchange-lib/exchange_api_context.c | 537 |
1 files changed, 0 insertions, 537 deletions
diff --git a/src/exchange-lib/exchange_api_context.c b/src/exchange-lib/exchange_api_context.c deleted file mode 100644 index 5049bb0a1..000000000 --- a/src/exchange-lib/exchange_api_context.c +++ /dev/null @@ -1,537 +0,0 @@ -/* - This file is part of TALER - Copyright (C) 2014, 2015 GNUnet e.V. - - TALER is free software; you can redistribute it and/or modify it under the - terms of the GNU General Public License as published by the Free Software - Foundation; either version 3, or (at your option) any later version. - - TALER is distributed in the hope that it will be useful, but WITHOUT ANY - WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR - A PARTICULAR PURPOSE. See the GNU General Public License for more details. - - You should have received a copy of the GNU General Public License along with - TALER; see the file COPYING. If not, If not, see - <http://www.gnu.org/licenses/> -*/ -/** - * @file exchange-lib/exchange_api_context.c - * @brief Implementation of the context part of the exchange's HTTP API - * @author Sree Harsha Totakura <sreeharsha@totakura.in> - * @author Christian Grothoff - */ -#include "platform.h" -#include <curl/curl.h> -#include "taler_exchange_service.h" -#include "exchange_api_context.h" - - -/** - * Log error related to CURL operations. - * - * @param type log level - * @param function which function failed to run - * @param code what was the curl error code - */ -#define CURL_STRERROR(type, function, code) \ - GNUNET_log (type, \ - "Curl function `%s' has failed at `%s:%d' with error: %s\n", \ - function, __FILE__, __LINE__, curl_easy_strerror (code)); - -/** - * Print JSON parsing related error information - */ -#define JSON_WARN(error) \ - GNUNET_log (GNUNET_ERROR_TYPE_WARNING, \ - "JSON parsing failed at %s:%u: %s (%s)\n", \ - __FILE__, __LINE__, error.text, error.source) - - -/** - * Failsafe flag. Raised if our constructor fails to initialize - * the Curl library. - */ -static int TALER_EXCHANGE_curl_fail; - - -/** - * Jobs are CURL requests running within a `struct TALER_EXCHANGE_Context`. - */ -struct MAC_Job -{ - - /** - * We keep jobs in a DLL. - */ - struct MAC_Job *next; - - /** - * We keep jobs in a DLL. - */ - struct MAC_Job *prev; - - /** - * Easy handle of the job. - */ - CURL *easy_handle; - - /** - * Context this job runs in. - */ - struct TALER_EXCHANGE_Context *ctx; - - /** - * Function to call upon completion. - */ - MAC_JobCompletionCallback jcc; - - /** - * Closure for @e jcc. - */ - void *jcc_cls; - -}; - - -/** - * Context - */ -struct TALER_EXCHANGE_Context -{ - /** - * Curl multi handle - */ - CURLM *multi; - - /** - * Curl share handle - */ - CURLSH *share; - - /** - * We keep jobs in a DLL. - */ - struct MAC_Job *jobs_head; - - /** - * We keep jobs in a DLL. - */ - struct MAC_Job *jobs_tail; - - /** - * HTTP header "application/json", created once and used - * for all requests that need it. - */ - struct curl_slist *json_header; - -}; - - -/** - * Initialise this library. This function should be called before using any of - * the following functions. - * - * @return library context - */ -struct TALER_EXCHANGE_Context * -TALER_EXCHANGE_init () -{ - struct TALER_EXCHANGE_Context *ctx; - CURLM *multi; - CURLSH *share; - - if (TALER_EXCHANGE_curl_fail) - { - GNUNET_log (GNUNET_ERROR_TYPE_ERROR, - "Curl was not initialised properly\n"); - return NULL; - } - if (NULL == (multi = curl_multi_init ())) - { - GNUNET_log (GNUNET_ERROR_TYPE_ERROR, - "Failed to create a Curl multi handle\n"); - return NULL; - } - if (NULL == (share = curl_share_init ())) - { - GNUNET_log (GNUNET_ERROR_TYPE_ERROR, - "Failed to create a Curl share handle\n"); - return NULL; - } - ctx = GNUNET_new (struct TALER_EXCHANGE_Context); - ctx->multi = multi; - ctx->share = share; - GNUNET_assert (NULL != (ctx->json_header = - curl_slist_append (NULL, - "Content-Type: application/json"))); - return ctx; -} - - -/** - * Schedule a CURL request to be executed and call the given @a jcc - * upon its completion. Note that the context will make use of the - * CURLOPT_PRIVATE facility of the CURL @a eh. Applications can - * instead use #MAC_easy_to_closure to extract the @a jcc_cls argument - * from a valid @a eh afterwards. - * - * This function modifies the CURL handle to add the - * "Content-Type: application/json" header if @a add_json is set. - * - * @param ctx context to execute the job in - * @param eh curl easy handle for the request, will - * be executed AND cleaned up - * @param add_json add "application/json" content type header - * @param jcc callback to invoke upon completion - * @param jcc_cls closure for @a jcc - */ -struct MAC_Job * -MAC_job_add (struct TALER_EXCHANGE_Context *ctx, - CURL *eh, - int add_json, - MAC_JobCompletionCallback jcc, - void *jcc_cls) -{ - struct MAC_Job *job; - - if (GNUNET_YES == add_json) - GNUNET_assert (CURLE_OK == - curl_easy_setopt (eh, - CURLOPT_HTTPHEADER, - ctx->json_header)); - - job = GNUNET_new (struct MAC_Job); - job->easy_handle = eh; - job->ctx = ctx; - job->jcc = jcc; - job->jcc_cls = jcc_cls; - GNUNET_CONTAINER_DLL_insert (ctx->jobs_head, - ctx->jobs_tail, - job); - GNUNET_assert (CURLE_OK == - curl_easy_setopt (eh, - CURLOPT_PRIVATE, - job)); - GNUNET_assert (CURLE_OK == - curl_easy_setopt (eh, - CURLOPT_SHARE, - ctx->share)); - GNUNET_assert (CURLM_OK == - curl_multi_add_handle (ctx->multi, - eh)); - return job; -} - - -/** - * Obtain the `jcc_cls` argument from an `eh` that was - * given to #MAC_job_add(). - * - * @param eh easy handle that was used - * @return the `jcc_cls` that was given to #MAC_job_add(). - */ -void * -MAC_easy_to_closure (CURL *eh) -{ - struct MAC_Job *job; - - GNUNET_assert (CURLE_OK == - curl_easy_getinfo (eh, - CURLINFO_PRIVATE, - (char **) &job)); - return job->jcc_cls; -} - - -/** - * Cancel a job. Must only be called before the job completion - * callback is called for the respective job. - * - * @param job job to cancel - */ -void -MAC_job_cancel (struct MAC_Job *job) -{ - struct TALER_EXCHANGE_Context *ctx = job->ctx; - - GNUNET_CONTAINER_DLL_remove (ctx->jobs_head, - ctx->jobs_tail, - job); - GNUNET_assert (CURLM_OK == - curl_multi_remove_handle (ctx->multi, - job->easy_handle)); - curl_easy_cleanup (job->easy_handle); - GNUNET_free (job); -} - - -/** - * Run the main event loop for the Taler interaction. - * - * @param ctx the library context - */ -void -TALER_EXCHANGE_perform (struct TALER_EXCHANGE_Context *ctx) -{ - CURLMsg *cmsg; - struct MAC_Job *job; - int n_running; - int n_completed; - - (void) curl_multi_perform (ctx->multi, - &n_running); - while (NULL != (cmsg = curl_multi_info_read (ctx->multi, - &n_completed))) - { - /* Only documented return value is CURLMSG_DONE */ - GNUNET_break (CURLMSG_DONE == cmsg->msg); - GNUNET_assert (CURLE_OK == - curl_easy_getinfo (cmsg->easy_handle, - CURLINFO_PRIVATE, - (char **) &job)); - GNUNET_assert (job->ctx == ctx); - job->jcc (job->jcc_cls, - cmsg->easy_handle); - MAC_job_cancel (job); - } -} - - -/** - * Obtain the information for a select() call to wait until - * #TALER_EXCHANGE_perform() is ready again. Note that calling - * any other TALER_EXCHANGE-API may also imply that the library - * is again ready for #TALER_EXCHANGE_perform(). - * - * Basically, a client should use this API to prepare for select(), - * then block on select(), then call #TALER_EXCHANGE_perform() and then - * start again until the work with the context is done. - * - * This function will NOT zero out the sets and assumes that @a max_fd - * and @a timeout are already set to minimal applicable values. It is - * safe to give this API FD-sets and @a max_fd and @a timeout that are - * already initialized to some other descriptors that need to go into - * the select() call. - * - * @param ctx context to get the event loop information for - * @param read_fd_set will be set for any pending read operations - * @param write_fd_set will be set for any pending write operations - * @param except_fd_set is here because curl_multi_fdset() has this argument - * @param max_fd set to the highest FD included in any set; - * if the existing sets have no FDs in it, the initial - * value should be "-1". (Note that `max_fd + 1` will need - * to be passed to select().) - * @param timeout set to the timeout in milliseconds (!); -1 means - * no timeout (NULL, blocking forever is OK), 0 means to - * proceed immediately with #TALER_EXCHANGE_perform(). - */ -void -TALER_EXCHANGE_get_select_info (struct TALER_EXCHANGE_Context *ctx, - fd_set *read_fd_set, - fd_set *write_fd_set, - fd_set *except_fd_set, - int *max_fd, - long *timeout) -{ - long to; - int m; - - m = -1; - GNUNET_assert (CURLM_OK == - curl_multi_fdset (ctx->multi, - read_fd_set, - write_fd_set, - except_fd_set, - &m)); - to = *timeout; - *max_fd = GNUNET_MAX (m, *max_fd); - GNUNET_assert (CURLM_OK == - curl_multi_timeout (ctx->multi, - &to)); - - /* Only if what we got back from curl is smaller than what we - already had (-1 == infinity!), then update timeout */ - if ( (to < *timeout) && - (-1 != to) ) - *timeout = to; - if ( (-1 == (*timeout)) && - (NULL != ctx->jobs_head) ) - *timeout = to; -} - - -/** - * Cleanup library initialisation resources. This function should be called - * after using this library to cleanup the resources occupied during library's - * initialisation. - * - * @param ctx the library context - */ -void -TALER_EXCHANGE_fini (struct TALER_EXCHANGE_Context *ctx) -{ - /* all jobs must have been cancelled at this time, assert this */ - GNUNET_assert (NULL == ctx->jobs_head); - curl_share_cleanup (ctx->share); - curl_multi_cleanup (ctx->multi); - curl_slist_free_all (ctx->json_header); - GNUNET_free (ctx); -} - - -/** - * Callback used when downloading the reply to an HTTP request. - * Just appends all of the data to the `buf` in the - * `struct MAC_DownloadBuffer` for further processing. The size of - * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if - * the download exceeds this size, we abort with an error. - * - * @param bufptr data downloaded via HTTP - * @param size size of an item in @a bufptr - * @param nitems number of items in @a bufptr - * @param cls the `struct MAC_DownloadBuffer` - * @return number of bytes processed from @a bufptr - */ -size_t -MAC_download_cb (char *bufptr, - size_t size, - size_t nitems, - void *cls) -{ - struct MAC_DownloadBuffer *db = cls; - size_t msize; - void *buf; - - if (0 == size * nitems) - { - /* Nothing (left) to do */ - return 0; - } - msize = size * nitems; - if ( (msize + db->buf_size) >= GNUNET_MAX_MALLOC_CHECKED) - { - db->eno = ENOMEM; - return 0; /* signals an error to curl */ - } - db->buf = GNUNET_realloc (db->buf, - db->buf_size + msize); - buf = db->buf + db->buf_size; - memcpy (buf, bufptr, msize); - db->buf_size += msize; - return msize; -} - - -/** - * Obtain information about the final result about the - * HTTP download. If the download was successful, parses - * the JSON in the @a db and returns it. Also returns - * the HTTP @a response_code. If the download failed, - * the return value is NULL. The response code is set - * in any case, on download errors to zero. - * - * Calling this function also cleans up @a db. - * - * @param db download buffer - * @param eh CURL handle (to get the response code) - * @param[out] response_code set to the HTTP response code - * (or zero if we aborted the download, i.e. - * because the response was too big, or if - * the JSON we received was malformed). - * @return NULL if downloading a JSON reply failed - */ -json_t * -MAC_download_get_result (struct MAC_DownloadBuffer *db, - CURL *eh, - long *response_code) -{ - json_t *json; - json_error_t error; - char *ct; - - if ( (CURLE_OK != - curl_easy_getinfo (eh, - CURLINFO_CONTENT_TYPE, - &ct)) || - (NULL == ct) || - (0 != strcasecmp (ct, - "application/json")) ) - { - /* No content type or explicitly not JSON, refuse to parse - (but keep response code) */ - if (CURLE_OK != - curl_easy_getinfo (eh, - CURLINFO_RESPONSE_CODE, - response_code)) - { - /* unexpected error... */ - GNUNET_break (0); - *response_code = 0; - } - return NULL; - } - - json = NULL; - if (0 == db->eno) - { - json = json_loadb (db->buf, - db->buf_size, - JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK, - &error); - if (NULL == json) - { - JSON_WARN (error); - *response_code = 0; - } - } - GNUNET_free_non_null (db->buf); - db->buf = NULL; - db->buf_size = 0; - if (NULL != json) - { - if (CURLE_OK != - curl_easy_getinfo (eh, - CURLINFO_RESPONSE_CODE, - response_code)) - { - /* unexpected error... */ - GNUNET_break (0); - *response_code = 0; - } - } - return json; -} - - -/** - * Initial global setup logic, specifically runs the Curl setup. - */ -__attribute__ ((constructor)) -void -TALER_EXCHANGE_constructor__ (void) -{ - CURLcode ret; - - if (CURLE_OK != (ret = curl_global_init (CURL_GLOBAL_DEFAULT))) - { - CURL_STRERROR (GNUNET_ERROR_TYPE_ERROR, - "curl_global_init", - ret); - TALER_EXCHANGE_curl_fail = 1; - } -} - - -/** - * Cleans up after us, specifically runs the Curl cleanup. - */ -__attribute__ ((destructor)) -void -TALER_EXCHANGE_destructor__ (void) -{ - if (TALER_EXCHANGE_curl_fail) - return; - curl_global_cleanup (); -} - -/* end of exchange_api_context.c */ |