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Diffstat (limited to 'src/mhd/mhd_parsing.c')
| -rw-r--r-- | src/mhd/mhd_parsing.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/src/mhd/mhd_parsing.c b/src/mhd/mhd_parsing.c new file mode 100644 index 000000000..0b070ffe5 --- /dev/null +++ b/src/mhd/mhd_parsing.c @@ -0,0 +1,294 @@ +/* + This file is part of TALER + Copyright (C) 2014--2019 Taler Systems SA + + 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 mhd_parsing.c + * @brief functions to parse incoming requests (MHD arguments and JSON snippets) + * @author Florian Dold + * @author Benedikt Mueller + * @author Christian Grothoff + */ +#include "platform.h" +#include <gnunet/gnunet_util_lib.h> +#include <gnunet/gnunet_json_lib.h> +#include "taler_json_lib.h" +#include "taler_mhd_lib.h" + + +/** + * Maximum POST request size. + */ +#define REQUEST_BUFFER_MAX (1024 * 1024) + + +/** + * Process a POST request containing a JSON object. This function + * realizes an MHD POST processor that will (incrementally) process + * JSON data uploaded to the HTTP server. It will store the required + * state in the @a con_cls, which must be cleaned up using + * #TALER_MHD_post_cleanup_callback(). + * + * @param connection the MHD connection + * @param con_cls the closure (points to a `struct Buffer *`) + * @param upload_data the POST data + * @param upload_data_size number of bytes in @a upload_data + * @param json the JSON object for a completed request + * @return + * #GNUNET_YES if json object was parsed or at least + * may be parsed in the future (call again); + * `*json` will be NULL if we need to be called again, + * and non-NULL if we are done. + * #GNUNET_NO is request incomplete or invalid + * (error message was generated) + * #GNUNET_SYSERR on internal error + * (we could not even queue an error message, + * close HTTP session with MHD_NO) + */ +int +TALER_MHD_parse_post_json (struct MHD_Connection *connection, + void **con_cls, + const char *upload_data, + size_t *upload_data_size, + json_t **json) +{ + enum GNUNET_JSON_PostResult pr; + + pr = GNUNET_JSON_post_parser (REQUEST_BUFFER_MAX, + connection, + con_cls, + upload_data, + upload_data_size, + json); + switch (pr) + { + case GNUNET_JSON_PR_OUT_OF_MEMORY: + return (MHD_NO == + TALER_MHD_reply_with_error + (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_PARSER_OUT_OF_MEMORY, + "out of memory")) ? GNUNET_SYSERR : GNUNET_NO; + + case GNUNET_JSON_PR_CONTINUE: + return GNUNET_YES; + case GNUNET_JSON_PR_REQUEST_TOO_LARGE: + return (MHD_NO == + TALER_MHD_reply_request_too_large + (connection)) ? GNUNET_SYSERR : GNUNET_NO; + case GNUNET_JSON_PR_JSON_INVALID: + return (MHD_YES == + TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_JSON_INVALID, + "invalid JSON uploaded")) + ? GNUNET_NO : GNUNET_SYSERR; + case GNUNET_JSON_PR_SUCCESS: + GNUNET_break (NULL != *json); + return GNUNET_YES; + } + /* this should never happen */ + GNUNET_break (0); + return GNUNET_SYSERR; +} + + +/** + * Function called whenever we are done with a request + * to clean up our state. + * + * @param con_cls value as it was left by + * #TALER_MHD_post_json(), to be cleaned up + */ +void +TALER_MHD_parse_post_cleanup_callback (void *con_cls) +{ + // FIXME: this should probably NOT be done with a 'void *' like this! + GNUNET_JSON_post_parser_cleanup (con_cls); +} + + +/** + * Extract base32crockford encoded data from request. + * + * Queues an error response to the connection if the parameter is + * missing or invalid. + * + * @param connection the MHD connection + * @param param_name the name of the parameter with the key + * @param[out] out_data pointer to store the result + * @param out_size expected size of data + * @return + * #GNUNET_YES if the the argument is present + * #GNUNET_NO if the argument is absent or malformed + * #GNUNET_SYSERR on internal error (error response could not be sent) + */ +int +TALER_MHD_parse_request_arg_data (struct MHD_Connection *connection, + const char *param_name, + void *out_data, + size_t out_size) +{ + const char *str; + + str = MHD_lookup_connection_value (connection, + MHD_GET_ARGUMENT_KIND, + param_name); + if (NULL == str) + { + return (MHD_NO == + TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_PARAMETER_MISSING, + param_name)) + ? GNUNET_SYSERR : GNUNET_NO; + } + if (GNUNET_OK != + GNUNET_STRINGS_string_to_data (str, + strlen (str), + out_data, + out_size)) + return (MHD_NO == + TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_PARAMETER_MALFORMED, + param_name)) + ? GNUNET_SYSERR : GNUNET_NO; + return GNUNET_OK; +} + + +/** + * Parse JSON object into components based on the given field + * specification. Generates error response on parse errors. + * + * @param connection the connection to send an error response to + * @param root the JSON node to start the navigation at. + * @param[in,out] spec field specification for the parser + * @return + * #GNUNET_YES if navigation was successful (caller is responsible + * for freeing allocated variable-size data using + * GNUNET_JSON_parse_free() when done) + * #GNUNET_NO if json is malformed, error response was generated + * #GNUNET_SYSERR on internal error + */ +int +TALER_MHD_parse_json_data (struct MHD_Connection *connection, + const json_t *root, + struct GNUNET_JSON_Specification *spec) +{ + int ret; + const char *error_json_name; + unsigned int error_line; + + ret = GNUNET_JSON_parse (root, + spec, + &error_json_name, + &error_line); + if (GNUNET_SYSERR == ret) + { + if (NULL == error_json_name) + error_json_name = "<no field>"; + ret = (MHD_YES == + TALER_MHD_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:s, s:I}", + "hint", "JSON parse error", + "code", + (json_int_t) + TALER_EC_JSON_INVALID_WITH_DETAILS, + "field", error_json_name, + "line", (json_int_t) error_line)) + ? GNUNET_NO : GNUNET_SYSERR; + return ret; + } + return GNUNET_YES; +} + + +/** + * Parse JSON array into components based on the given field + * specification. Generates error response on parse errors. + * + * @param connection the connection to send an error response to + * @param root the JSON node to start the navigation at. + * @param[in,out] spec field specification for the parser + * @param ... -1-terminated list of array offsets of type 'int' + * @return + * #GNUNET_YES if navigation was successful (caller is responsible + * for freeing allocated variable-size data using + * GNUNET_JSON_parse_free() when done) + * #GNUNET_NO if json is malformed, error response was generated + * #GNUNET_SYSERR on internal error + */ +int +TALER_MHD_parse_json_array (struct MHD_Connection *connection, + const json_t *root, + struct GNUNET_JSON_Specification *spec, + ...) +{ + int ret; + const char *error_json_name; + unsigned int error_line; + va_list ap; + json_int_t dim; + + va_start (ap, spec); + dim = 0; + while ( (-1 != (ret = va_arg (ap, int))) && + (NULL != root) ) + { + dim++; + root = json_array_get (root, ret); + } + va_end (ap); + if (NULL == root) + { + ret = (MHD_YES == + TALER_MHD_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:I}", + "hint", "expected array", + "code", + (json_int_t) + TALER_EC_JSON_INVALID_WITH_DETAILS, + "dimension", dim)) + ? GNUNET_NO : GNUNET_SYSERR; + return ret; + } + ret = GNUNET_JSON_parse (root, + spec, + &error_json_name, + &error_line); + if (GNUNET_SYSERR == ret) + { + if (NULL == error_json_name) + error_json_name = "<no field>"; + ret = (MHD_YES == + TALER_MHD_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:I, s:I}", + "hint", error_json_name, + "code", + (json_int_t) + TALER_EC_JSON_INVALID_WITH_DETAILS, + "line", (json_int_t) error_line)) + ? GNUNET_NO : GNUNET_SYSERR; + return ret; + } + return GNUNET_YES; +} + + +/* end of mhd_parsing.c */ |