/*
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
*/
/**
* @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
#include
#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_parse_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:
GNUNET_break (NULL == *json);
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:
GNUNET_break (NULL == *json);
return GNUNET_YES;
case GNUNET_JSON_PR_REQUEST_TOO_LARGE:
GNUNET_break (NULL == *json);
return (MHD_NO ==
TALER_MHD_reply_request_too_large
(connection)) ? GNUNET_SYSERR : GNUNET_NO;
case GNUNET_JSON_PR_JSON_INVALID:
GNUNET_break (NULL == *json);
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_parse_post_json(), to be cleaned up
*/
void
TALER_MHD_parse_post_cleanup_callback (void *con_cls)
{
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 = "";
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 = "";
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 */