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Diffstat (limited to 'src/lib/merchant_api_tip_authorize.c')
-rw-r--r-- | src/lib/merchant_api_tip_authorize.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/src/lib/merchant_api_tip_authorize.c b/src/lib/merchant_api_tip_authorize.c new file mode 100644 index 00000000..eb3e657e --- /dev/null +++ b/src/lib/merchant_api_tip_authorize.c @@ -0,0 +1,267 @@ +/* + This file is part of TALER + Copyright (C) 2014-2017 Taler Systems SA + + TALER is free software; you can redistribute it and/or modify it under the + terms of the GNU Lesser General Public License as published by the Free Software + Foundation; either version 2.1, 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License along with + TALER; see the file COPYING.LGPL. If not, see + <http://www.gnu.org/licenses/> +*/ +/** + * @file lib/merchant_api_tip_authorize.c + * @brief Implementation of the /tip-authorize request of the merchant's HTTP API + * @author Marcello Stanisci + * @author Christian Grothoff + */ +#include "platform.h" +#include <curl/curl.h> +#include <jansson.h> +#include <microhttpd.h> /* just for HTTP status codes */ +#include <gnunet/gnunet_util_lib.h> +#include <gnunet/gnunet_curl_lib.h> +#include "taler_merchant_service.h" +#include <taler/taler_json_lib.h> +#include <taler/taler_signatures.h> +#include "merchant_api_common.h" + + +/** + * @brief A handle for tracking transactions. + */ +struct TALER_MERCHANT_TipAuthorizeOperation +{ + + /** + * The url for this request. + */ + char *url; + + /** + * JSON encoding of the request to POST. + */ + char *json_enc; + + /** + * Handle for the request. + */ + struct GNUNET_CURL_Job *job; + + /** + * Function to call with the result. + */ + TALER_MERCHANT_TipAuthorizeCallback cb; + + /** + * Closure for @a cb. + */ + void *cb_cls; + + /** + * Reference to the execution context. + */ + struct GNUNET_CURL_Context *ctx; +}; + + +/** + * We got a 200 response back from the exchange (or the merchant). + * Now we need to parse the response and if it is well-formed, + * call the callback (and set it to NULL afterwards). + * + * @param tao handle of the original authorization operation + * @param json cryptographic proof returned by the exchange/merchant + * @return #GNUNET_OK if response is valid + */ +static int +check_ok (struct TALER_MERCHANT_TipAuthorizeOperation *tao, + const json_t *json) +{ + struct GNUNET_HashCode tip_id; + struct GNUNET_TIME_Absolute tip_expiration; + const char *exchange_uri; + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_absolute_time ("expiration", &tip_expiration), + GNUNET_JSON_spec_fixed_auto ("tip_id", &tip_id), + GNUNET_JSON_spec_string ("exchange_uri", &exchange_uri), + GNUNET_JSON_spec_end() + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (json, + spec, + NULL, NULL)) + { + GNUNET_break_op (0); + return GNUNET_SYSERR; + } + tao->cb (tao->cb_cls, + MHD_HTTP_OK, + TALER_JSON_get_error_code (json), + &tip_id, + tip_expiration, + exchange_uri); + tao->cb = NULL; /* do not call twice */ + GNUNET_JSON_parse_free (spec); + return GNUNET_OK; +} + + +/** + * Function called when we're done processing the + * HTTP /track/transaction request. + * + * @param cls the `struct TALER_MERCHANT_TipAuthorizeOperation` + * @param response_code HTTP response code, 0 on error + * @param json response body, NULL if not in JSON + */ +static void +handle_tip_authorize_finished (void *cls, + long response_code, + const json_t *json) +{ + struct TALER_MERCHANT_TipAuthorizeOperation *tao = cls; + + tao->job = NULL; + switch (response_code) + { + case MHD_HTTP_OK: + if (GNUNET_OK != check_ok (tao, + json)) + { + GNUNET_break_op (0); + response_code = 0; + } + break; + case MHD_HTTP_INTERNAL_SERVER_ERROR: + /* Server had an internal issue; we should retry, but this API + leaves this to the application */ + break; + default: + /* unexpected response code */ + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Unexpected response code %u\n", + (unsigned int) response_code); + GNUNET_break (0); + response_code = 0; + break; + } + if (NULL != tao->cb) + tao->cb (tao->cb_cls, + response_code, + TALER_JSON_get_error_code (json), + NULL, + GNUNET_TIME_UNIT_ZERO_ABS, + NULL); + TALER_MERCHANT_tip_authorize_cancel (tao); +} + + +/** + * Issue a /tip-authorize request to the backend. Informs the backend + * that a tip should be created. + * + * @param ctx execution context + * @param backend_uri base URL of the merchant backend + * @param amount amount to be handed out as a tip + * @param instance which backend instance should create the tip (identifies the reserve and exchange) + * @param justification which justification should be stored (human-readable reason for the tip) + * @param authorize_cb callback which will work the response gotten from the backend + * @param authorize_cb_cls closure to pass to @a authorize_cb + * @return handle for this operation, NULL upon errors + */ +struct TALER_MERCHANT_TipAuthorizeOperation * +TALER_MERCHANT_tip_authorize (struct GNUNET_CURL_Context *ctx, + const char *backend_uri, + const struct TALER_Amount *amount, + const char *instance, + const char *justification, + TALER_MERCHANT_TipAuthorizeCallback authorize_cb, + void *authorize_cb_cls) +{ + struct TALER_MERCHANT_TipAuthorizeOperation *tao; + CURL *eh; + json_t *te_obj; + + tao = GNUNET_new (struct TALER_MERCHANT_TipAuthorizeOperation); + tao->ctx = ctx; + tao->cb = authorize_cb; + tao->cb_cls = authorize_cb_cls; + tao->url = MAH_path_to_url_ (backend_uri, + "/tip-authorize"); + te_obj = json_pack ("{" + " s:o," /* amount */ + " s:s," /* instance */ + " s:s," /* justification */ + "}", + "amount", TALER_JSON_from_amount (amount), + "instance", instance, + "justification", justification); + if (NULL == te_obj) + { + GNUNET_break (0); + GNUNET_free (tao->url); + return NULL; + } + if (NULL == (tao->json_enc = + json_dumps (te_obj, + JSON_COMPACT))) + { + GNUNET_break (0); + json_decref (te_obj); + GNUNET_free (tao->url); + GNUNET_free (tao); + return NULL; + } + json_decref (te_obj); + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Requesting URI '%s'\n", + tao->url); + eh = curl_easy_init (); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, + CURLOPT_URL, + tao->url)); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, + CURLOPT_POSTFIELDS, + tao->json_enc)); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, + CURLOPT_POSTFIELDSIZE, + strlen (tao->json_enc))); + tao->job = GNUNET_CURL_job_add (ctx, + eh, + GNUNET_YES, + &handle_tip_authorize_finished, + tao); + return tao; +} + + +/** + * Cancel a /track/transaction request. This function cannot be used + * on a request handle if a response is already served for it. + * + * @param tao handle to the tracking operation being cancelled + */ +void +TALER_MERCHANT_tip_authorize_cancel (struct TALER_MERCHANT_TipAuthorizeOperation *tao) +{ + if (NULL != tao->job) + { + GNUNET_CURL_job_cancel (tao->job); + tao->job = NULL; + } + GNUNET_free_non_null (tao->json_enc); + GNUNET_free (tao->url); + GNUNET_free (tao); +} + +/* end of merchant_api_tip_authorize.c */ |