diff options
Diffstat (limited to 'src/lib/merchant_api_config.c')
-rw-r--r-- | src/lib/merchant_api_config.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/src/lib/merchant_api_config.c b/src/lib/merchant_api_config.c new file mode 100644 index 00000000..16c20141 --- /dev/null +++ b/src/lib/merchant_api_config.c @@ -0,0 +1,327 @@ +/* + This file is part of TALER + Copyright (C) 2014-2018, 2020 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_config.c + * @brief Implementation of the /config request of the merchant's HTTP API + * @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> + +/** + * Which version of the Taler protocol is implemented + * by this library? Used to determine compatibility. + */ +#define MERCHANT_PROTOCOL_CURRENT 0 + +/** + * How many configs are we backwards compatible with? + */ +#define MERCHANT_PROTOCOL_AGE 0 + + +/** + * @brief A handle for /config operations + */ +struct TALER_MERCHANT_ConfigGetHandle +{ + /** + * The url for this request. + */ + char *url; + + /** + * Handle for the request. + */ + struct GNUNET_CURL_Job *job; + + /** + * Function to call with the result. + */ + TALER_MERCHANT_ConfigCallback cb; + + /** + * Closure for @a cb. + */ + void *cb_cls; + + /** + * Reference to the execution context. + */ + struct GNUNET_CURL_Context *ctx; + +}; + + +/** + * Parse instance information from @a ia. + * + * @param ia JSON array (or NULL!) with instance data + * @param[in,out] ci config information to update + * @return #GNUNET_OK on success + */ +static int +parse_instances (const json_t *ia, + struct TALER_MERCHANT_ConfigInformation *ci) +{ + size_t index; + json_t *value; + int ret; + + if (NULL == ia) + return GNUNET_OK; /* permit not disclosing instances for now */ + if (! json_is_array (ia)) + { + GNUNET_break_op (0); + return GNUNET_SYSERR; + } + GNUNET_array_grow (ci->iis, + ci->iis_len, + json_array_size (ia)); + ret = GNUNET_OK; + json_array_foreach (ia, index, value) { + struct TALER_MERCHANT_InstanceInformation *ii = &ci->iis[index]; + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_fixed_auto ("merchant_pub", + &ii->merchant_pub), + GNUNET_JSON_spec_string ("instance_baseurl", + &ii->instance_baseurl), + GNUNET_JSON_spec_string ("name", + &ii->name), + GNUNET_JSON_spec_string ("tipping_exchange_baseurl", + &ii->tipping_exchange_baseurl), + GNUNET_JSON_spec_end () + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (value, + spec, + NULL, NULL)) + { + GNUNET_break_op (0); + ret = GNUNET_SYSERR; + } + } + return ret; +} + + +/** + * Function called when we're done processing the + * HTTP /track/transaction request. + * + * @param cls the `struct TALER_MERCHANT_ConfigGetHandle` + * @param response_code HTTP response code, 0 on error + * @param json response body, NULL if not in JSON + */ +static void +handle_config_finished (void *cls, + long response_code, + const void *response) +{ + struct TALER_MERCHANT_ConfigGetHandle *vgh = cls; + const json_t *json = response; + struct TALER_MERCHANT_HttpResponse hr = { + .http_status = (unsigned int) response_code, + .reply = json + }; + + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Got /config response with status code %u\n", + (unsigned int) response_code); + + vgh->job = NULL; + switch (response_code) + { + case MHD_HTTP_OK: + { + struct TALER_MERCHANT_ConfigInformation vi = { + .iis = NULL, + .iis_len = 0 + }; + enum TALER_MERCHANT_VersionCompatibility vc = + TALER_MERCHANT_VC_PROTOCOL_ERROR; + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_string ("currency", + &vi.currency), + GNUNET_JSON_spec_string ("version", + &vi.version), + GNUNET_JSON_spec_end () + }; + + if (GNUNET_OK != + GNUNET_JSON_parse (json, + spec, + NULL, NULL)) + { + hr.http_status = 0; + hr.ec = TALER_EC_INVALID_RESPONSE; + } + else + { + unsigned int age; + unsigned int revision; + unsigned int current; + + if (3 != sscanf (vi.version, + "%u:%u:%u", + ¤t, + &revision, + &age)) + { + hr.http_status = 0; + hr.ec = TALER_EC_INVALID_RESPONSE; + } + else + { + vc = TALER_MERCHANT_VC_MATCH; + if (MERCHANT_PROTOCOL_CURRENT < current) + { + vc |= TALER_MERCHANT_VC_NEWER; + if (MERCHANT_PROTOCOL_CURRENT < current - age) + vc |= TALER_MERCHANT_VC_INCOMPATIBLE; + } + if (MERCHANT_PROTOCOL_CURRENT > current) + { + vc |= TALER_MERCHANT_VC_OLDER; + if (MERCHANT_PROTOCOL_CURRENT - MERCHANT_PROTOCOL_AGE > current) + vc |= TALER_MERCHANT_VC_INCOMPATIBLE; + } + } + } + if (0 == (vc & (TALER_MERCHANT_VC_INCOMPATIBLE + | TALER_MERCHANT_VC_PROTOCOL_ERROR))) + { + if (GNUNET_OK != + parse_instances (json_object_get (json, + "instances"), + &vi)) + { + /* Let's keep the 200 OK, as we got at least the version data */ + hr.ec = TALER_EC_INVALID_RESPONSE; + } + } + vgh->cb (vgh->cb_cls, + &hr, + &vi, + vc); + GNUNET_array_grow (vi.iis, + vi.iis_len, + 0); + TALER_MERCHANT_config_get_cancel (vgh); + return; + } + default: + /* unexpected response code */ + hr.ec = TALER_JSON_get_error_code (json); + hr.hint = TALER_JSON_get_error_hint (json); + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Unexpected response code %u/%d\n", + (unsigned int) response_code, + (int) hr.ec); + vgh->cb (vgh->cb_cls, + &hr, + NULL, + TALER_MERCHANT_VC_PROTOCOL_ERROR); + break; + } + TALER_MERCHANT_config_get_cancel (vgh); +} + + +/** + * Get the config data of a merchant. Will connect to the merchant backend + * and obtain information about the backend. The respective information will + * be passed to the @a config_cb once available. + * + * @param ctx the context + * @param backend_url HTTP base URL for the backend + * @param config_cb function to call with the + * backend's config information + * @param config_cb_cls closure for @a config_cb + * @return the config check handle; NULL upon error + */ +struct TALER_MERCHANT_ConfigGetHandle * +TALER_MERCHANT_config_get (struct GNUNET_CURL_Context *ctx, + const char *backend_url, + TALER_MERCHANT_ConfigCallback config_cb, + void *config_cb_cls) +{ + struct TALER_MERCHANT_ConfigGetHandle *vgh; + CURL *eh; + + vgh = GNUNET_new (struct TALER_MERCHANT_ConfigGetHandle); + vgh->ctx = ctx; + vgh->cb = config_cb; + vgh->cb_cls = config_cb_cls; + vgh->url = TALER_url_join (backend_url, + "config", + NULL); + if (NULL == vgh->url) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Could not construct request URL.\n"); + GNUNET_free (vgh); + return NULL; + } + + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Requesting URL '%s'\n", + vgh->url); + + eh = curl_easy_init (); + GNUNET_assert (CURLE_OK == + curl_easy_setopt (eh, + CURLOPT_URL, + vgh->url)); + + vgh->job = GNUNET_CURL_job_add (ctx, + eh, + GNUNET_YES, + &handle_config_finished, + vgh); + return vgh; +} + + +/** + * Cancel /config request. Must not be called by clients after + * the callback was invoked. + * + * @param vgh request to cancel. + */ +void +TALER_MERCHANT_config_get_cancel (struct TALER_MERCHANT_ConfigGetHandle *vgh) +{ + if (NULL != vgh->job) + { + GNUNET_CURL_job_cancel (vgh->job); + vgh->job = NULL; + } + GNUNET_free (vgh->url); + GNUNET_free (vgh); +} + + +/* end of merchant_api_config.c */ |