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/*
This file is part of TALER
Copyright (C) 2014, 2015 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, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-mint-httpd_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 "taler-mint-httpd_parsing.h"
#include "taler-mint-httpd_responses.h"
/**
* Initial size for POST request buffer.
*/
#define REQUEST_BUFFER_INITIAL (2*1024)
/**
* Maximum POST request size.
*/
#define REQUEST_BUFFER_MAX (1024*1024)
/**
* Buffer for POST requests.
*/
struct Buffer
{
/**
* Allocated memory
*/
char *data;
/**
* Number of valid bytes in buffer.
*/
size_t fill;
/**
* Number of allocated bytes in buffer.
*/
size_t alloc;
};
/**
* Initialize a buffer.
*
* @param buf the buffer to initialize
* @param data the initial data
* @param data_size size of the initial data
* @param alloc_size size of the buffer
* @param max_size maximum size that the buffer can grow to
* @return a GNUnet result code
*/
static int
buffer_init (struct Buffer *buf,
const void *data,
size_t data_size,
size_t alloc_size,
size_t max_size)
{
if (data_size > max_size || alloc_size > max_size)
return GNUNET_SYSERR;
if (data_size > alloc_size)
alloc_size = data_size;
buf->data = GNUNET_malloc (alloc_size);
memcpy (buf->data, data, data_size);
return GNUNET_OK;
}
/**
* Free the data in a buffer. Does *not* free
* the buffer object itself.
*
* @param buf buffer to de-initialize
*/
static void
buffer_deinit (struct Buffer *buf)
{
GNUNET_free (buf->data);
buf->data = NULL;
}
/**
* Append data to a buffer, growing the buffer if necessary.
*
* @param buf the buffer to append to
* @param data the data to append
* @param data_size the size of @a data
* @param max_size maximum size that the buffer can grow to
* @return #GNUNET_OK on success,
* #GNUNET_NO if the buffer can't accomodate for the new data
*/
static int
buffer_append (struct Buffer *buf,
const void *data,
size_t data_size,
size_t max_size)
{
if (buf->fill + data_size > max_size)
return GNUNET_NO;
if (data_size + buf->fill > buf->alloc)
{
char *new_buf;
size_t new_size = buf->alloc;
while (new_size < buf->fill + data_size)
new_size += 2;
if (new_size > max_size)
return GNUNET_NO;
new_buf = GNUNET_malloc (new_size);
memcpy (new_buf, buf->data, buf->fill);
GNUNET_free (buf->data);
buf->data = new_buf;
buf->alloc = new_size;
}
memcpy (buf->data + buf->fill, data, data_size);
buf->fill += data_size;
return GNUNET_OK;
}
/**
* 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
* #TMH_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
TMH_PARSE_post_json (struct MHD_Connection *connection,
void **con_cls,
const char *upload_data,
size_t *upload_data_size,
json_t **json)
{
struct Buffer *r = *con_cls;
*json = NULL;
if (NULL == *con_cls)
{
/* We are seeing a fresh POST request. */
r = GNUNET_new (struct Buffer);
if (GNUNET_OK !=
buffer_init (r,
upload_data,
*upload_data_size,
REQUEST_BUFFER_INITIAL,
REQUEST_BUFFER_MAX))
{
*con_cls = NULL;
buffer_deinit (r);
GNUNET_free (r);
return (MHD_NO ==
TMH_RESPONSE_reply_internal_error (connection,
"out of memory"))
? GNUNET_SYSERR : GNUNET_NO;
}
/* everything OK, wait for more POST data */
*upload_data_size = 0;
*con_cls = r;
return GNUNET_YES;
}
if (0 != *upload_data_size)
{
/* We are seeing an old request with more data available. */
if (GNUNET_OK !=
buffer_append (r,
upload_data,
*upload_data_size,
REQUEST_BUFFER_MAX))
{
/* Request too long */
*con_cls = NULL;
buffer_deinit (r);
GNUNET_free (r);
return (MHD_NO ==
TMH_RESPONSE_reply_request_too_large (connection))
? GNUNET_SYSERR : GNUNET_NO;
}
/* everything OK, wait for more POST data */
*upload_data_size = 0;
return GNUNET_YES;
}
/* We have seen the whole request. */
*json = json_loadb (r->data,
r->fill,
0,
NULL);
if (NULL == *json)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to parse JSON request body\n");
return (MHD_YES ==
TMH_RESPONSE_reply_invalid_json (connection))
? GNUNET_NO : GNUNET_SYSERR;
}
buffer_deinit (r);
GNUNET_free (r);
*con_cls = NULL;
return GNUNET_YES;
}
/* end of taler-mint-httpd_parsing.c */
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