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Diffstat (limited to 'src/auditor/taler-auditor-httpd_responses.c')
| -rw-r--r-- | src/auditor/taler-auditor-httpd_responses.c | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/src/auditor/taler-auditor-httpd_responses.c b/src/auditor/taler-auditor-httpd_responses.c new file mode 100644 index 000000000..045a77772 --- /dev/null +++ b/src/auditor/taler-auditor-httpd_responses.c @@ -0,0 +1,479 @@ +/* + This file is part of TALER + Copyright (C) 2014-2017 Inria & GNUnet e.V. + + TALER is free software; you can redistribute it and/or modify it under the + terms of the GNU Affero 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 Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License along with + TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> +*/ +/** + * @file taler-exchange-httpd_responses.c + * @brief API for generating genric replies of the exchange; these + * functions are called TAH_RESPONSE_reply_ and they generate + * and queue MHD response objects for a given connection. + * @author Florian Dold + * @author Benedikt Mueller + * @author Christian Grothoff + */ +#include "platform.h" +#include <zlib.h> +#include "taler-auditor-httpd_responses.h" +#include "taler_util.h" +#include "taler_json_lib.h" + + +/** + * Add headers we want to return in every response. + * Useful for testing, like if we want to always close + * connections. + * + * @param response response to modify + */ +void +TAH_RESPONSE_add_global_headers (struct MHD_Response *response) +{ + if (TAH_auditor_connection_close) + GNUNET_break (MHD_YES == + MHD_add_response_header (response, + MHD_HTTP_HEADER_CONNECTION, + "close")); +} + + +/** + * Is HTTP body deflate compression supported by the client? + * + * @param connection connection to check + * @return #MHD_YES if 'deflate' compression is allowed + * + * Note that right now we're ignoring q-values, which is technically + * not correct, and also do not support "*" anywhere but in a line by + * itself. This should eventually be fixed, see also + * https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html + */ +int +TAH_RESPONSE_can_compress (struct MHD_Connection *connection) +{ + const char *ae; + const char *de; + + ae = MHD_lookup_connection_value (connection, + MHD_HEADER_KIND, + MHD_HTTP_HEADER_ACCEPT_ENCODING); + if (NULL == ae) + return MHD_NO; + if (0 == strcmp (ae, + "*")) + return MHD_YES; + de = strstr (ae, + "deflate"); + if (NULL == de) + return MHD_NO; + if ( ( (de == ae) || + (de[-1] == ',') || + (de[-1] == ' ') ) && + ( (de[strlen ("deflate")] == '\0') || + (de[strlen ("deflate")] == ',') || + (de[strlen ("deflate")] == ';') ) ) + return MHD_YES; + return MHD_NO; +} + + +/** + * Try to compress a response body. Updates @a buf and @a buf_size. + * + * @param[in,out] buf pointer to body to compress + * @param[in,out] buf_size pointer to initial size of @a buf + * @return #MHD_YES if @a buf was compressed + */ +int +TAH_RESPONSE_body_compress (void **buf, + size_t *buf_size) +{ + Bytef *cbuf; + uLongf cbuf_size; + int ret; + + cbuf_size = compressBound (*buf_size); + cbuf = malloc (cbuf_size); + if (NULL == cbuf) + return MHD_NO; + ret = compress (cbuf, + &cbuf_size, + (const Bytef *) *buf, + *buf_size); + if ( (Z_OK != ret) || + (cbuf_size >= *buf_size) ) + { + /* compression failed */ + free (cbuf); + return MHD_NO; + } + free (*buf); + *buf = (void *) cbuf; + *buf_size = (size_t) cbuf_size; + return MHD_YES; +} + + +/** + * Send JSON object as response. + * + * @param connection the MHD connection + * @param json the json object + * @param response_code the http response code + * @return MHD result code + */ +int +TAH_RESPONSE_reply_json (struct MHD_Connection *connection, + const json_t *json, + unsigned int response_code) +{ + struct MHD_Response *resp; + void *json_str; + size_t json_len; + int ret; + int comp; + + json_str = json_dumps (json, + JSON_INDENT(2)); + if (NULL == json_str) + { + /** + * This log helps to figure out which + * function called this one and assert-failed. + */ + TALER_LOG_ERROR ("Aborting json-packing for HTTP code: %u\n", + response_code); + + GNUNET_assert (0); + return MHD_NO; + } + json_len = strlen (json_str); + /* try to compress the body */ + comp = MHD_NO; + if (MHD_YES == + TAH_RESPONSE_can_compress (connection)) + comp = TAH_RESPONSE_body_compress (&json_str, + &json_len); + resp = MHD_create_response_from_buffer (json_len, + json_str, + MHD_RESPMEM_MUST_FREE); + if (NULL == resp) + { + free (json_str); + GNUNET_break (0); + return MHD_NO; + } + TAH_RESPONSE_add_global_headers (resp); + (void) MHD_add_response_header (resp, + MHD_HTTP_HEADER_CONTENT_TYPE, + "application/json"); + if (MHD_YES == comp) + { + /* Need to indicate to client that body is compressed */ + if (MHD_NO == + MHD_add_response_header (resp, + MHD_HTTP_HEADER_CONTENT_ENCODING, + "deflate")) + { + GNUNET_break (0); + MHD_destroy_response (resp); + return MHD_NO; + } + } + ret = MHD_queue_response (connection, + response_code, + resp); + MHD_destroy_response (resp); + return ret; +} + + +/** + * Function to call to handle the request by building a JSON + * reply from a format string and varargs. + * + * @param connection the MHD connection to handle + * @param response_code HTTP response code to use + * @param fmt format string for pack + * @param ... varargs + * @return MHD result code + */ +int +TAH_RESPONSE_reply_json_pack (struct MHD_Connection *connection, + unsigned int response_code, + const char *fmt, + ...) +{ + json_t *json; + va_list argp; + int ret; + json_error_t jerror; + + va_start (argp, fmt); + json = json_vpack_ex (&jerror, 0, fmt, argp); + va_end (argp); + if (NULL == json) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Failed to pack JSON with format `%s': %s\n", + fmt, + jerror.text); + GNUNET_break (0); + return MHD_NO; + } + ret = TAH_RESPONSE_reply_json (connection, + json, + response_code); + json_decref (json); + return ret; +} + + +/** + * Send a response indicating an invalid argument. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param param_name the parameter that is invalid + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_arg_invalid (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *param_name) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:s}", + "error", "invalid parameter", + "code", (json_int_t) ec, + "parameter", param_name); +} + + +/** + * Send a response indicating an argument refering to a + * resource unknown to the auditor (i.e. unknown reserve or + * denomination key). + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param param_name the parameter that is invalid + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_arg_unknown (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *param_name) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_NOT_FOUND, + "{s:s, s:I, s:s}", + "error", "unknown entity referenced", + "code", (json_int_t) ec, + "parameter", param_name); +} + + +/** + * Send a response indicating an invalid signature. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param param_name the parameter that is invalid + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_signature_invalid (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *param_name) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_UNAUTHORIZED, + "{s:s, s:I, s:s}", + "error", "invalid signature", + "code", (json_int_t) ec, + "parameter", param_name); +} + + +/** + * Send a response indicating a missing argument. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param param_name the parameter that is missing + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_arg_missing (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *param_name) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:s}", + "error", "missing parameter", + "code", (json_int_t) ec, + "parameter", param_name); +} + + +/** + * Send a response indicating permission denied. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param hint hint about why access was denied + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_permission_denied (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *hint) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_FORBIDDEN, + "{s:s, s:I, s:s}", + "error", "permission denied", + "code", (json_int_t) ec, + "hint", hint); +} + + +/** + * Send a response indicating an internal error. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param hint hint about the internal error's nature + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_internal_error (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *hint) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + "{s:s, s:I, s:s}", + "error", "internal error", + "code", (json_int_t) ec, + "hint", hint); +} + + +/** + * Send a response indicating an external error. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param hint hint about the error's nature + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_external_error (struct MHD_Connection *connection, + enum TALER_ErrorCode ec, + const char *hint) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:s}", + "error", "client error", + "code", (json_int_t) ec, + "hint", hint); +} + + +/** + * Send a response indicating an error committing a + * transaction (concurrent interference). + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_commit_error (struct MHD_Connection *connection, + enum TALER_ErrorCode ec) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + "{s:s, s:I}", + "error", "commit failure", + "code", (json_int_t) ec); +} + + +/** + * Send a response indicating a failure to talk to the Auditor's + * database. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_internal_db_error (struct MHD_Connection *connection, + enum TALER_ErrorCode ec) +{ + return TAH_RESPONSE_reply_internal_error (connection, + ec, + "Failure in database interaction"); +} + + +/** + * Send a response indicating that the request was too big. + * + * @param connection the MHD connection to use + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_request_too_large (struct MHD_Connection *connection) +{ + struct MHD_Response *resp; + int ret; + + resp = MHD_create_response_from_buffer (0, + NULL, + MHD_RESPMEM_PERSISTENT); + if (NULL == resp) + return MHD_NO; + TAH_RESPONSE_add_global_headers (resp); + ret = MHD_queue_response (connection, + MHD_HTTP_REQUEST_ENTITY_TOO_LARGE, + resp); + MHD_destroy_response (resp); + return ret; +} + + +/** + * Send a response indicating that the JSON was malformed. + * + * @param connection the MHD connection to use + * @return a MHD result code + */ +int +TAH_RESPONSE_reply_invalid_json (struct MHD_Connection *connection) +{ + return TAH_RESPONSE_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I}", + "error", "invalid json", + "code", (json_int_t) TALER_EC_JSON_INVALID); +} + + +/* end of taler-auditor-httpd_responses.c */ |