diff options
Diffstat (limited to 'src/mint/taler-mint-httpd_parsing.c')
| -rw-r--r-- | src/mint/taler-mint-httpd_parsing.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/src/mint/taler-mint-httpd_parsing.c b/src/mint/taler-mint-httpd_parsing.c new file mode 100644 index 000000000..a976c0c06 --- /dev/null +++ b/src/mint/taler-mint-httpd_parsing.c @@ -0,0 +1,453 @@ +/* + This file is part of TALER + (C) 2014 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 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 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 + * GNUNET_SYSERR on fatal error (out of memory?) + */ +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); + 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. + * + * @param connection the MHD connection + * @param con_cs the closure (contains a 'struct Buffer *') + * @param upload_data the POST data + * @param upload_data_size the POST data size + * @param json the JSON object for a completed request + * + * @returns + * GNUNET_YES if json object was parsed + * GNUNET_NO is request incomplete or invalid + * GNUNET_SYSERR on internal error + */ +int +process_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; + + 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 GNUNET_SYSERR; + } + *upload_data_size = 0; + *con_cls = r; + return GNUNET_NO; + } + 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 or we're out of memory. */ + + *con_cls = NULL; + buffer_deinit (r); + GNUNET_free (r); + return GNUNET_SYSERR; + } + *upload_data_size = 0; + return GNUNET_NO; + } + + /* We have seen the whole request. */ + + *json = json_loadb (r->data, r->fill, 0, NULL); + buffer_deinit (r); + GNUNET_free (r); + if (NULL == *json) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + "Can't parse JSON request body\n"); + return (MHD_YES == + TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s}", + "error", "invalid json")) + ? GNUNET_NO : GNUNET_SYSERR; + } + *con_cls = NULL; + + return GNUNET_YES; +} + + +/** + * Navigate through a JSON tree. + * + * Sends an error response if navigation is impossible (i.e. + * the JSON object is invalid) + * + * @param connection the connection to send an error response to + * @param root the JSON node to start the navigation at. + * @param ... navigation specification (see JNAV_*) + * @return GNUNET_YES if navigation was successful + * GNUNET_NO if json is malformed, error response was generated + * GNUNET_SYSERR on internal error + */ +int +request_json_require_nav (struct MHD_Connection *connection, + const json_t *root, ...) +{ + va_list argp; + int ignore = GNUNET_NO; + // what's our current path from 'root'? + json_t *path; + + path = json_array (); + + va_start(argp, root); + + while (1) + { + int command = va_arg(argp, int); + switch (command) + { + case JNAV_FIELD: + { + const char *fname = va_arg(argp, const char *); + if (GNUNET_YES == ignore) + break; + json_array_append_new (path, json_string (fname)); + root = json_object_get (root, fname); + if (NULL == root) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s,s:o}", + "error", + "missing field in JSON", + "path", + path); + ignore = GNUNET_YES; + break; + } + } + break; + case JNAV_INDEX: + { + int fnum = va_arg(argp, int); + if (GNUNET_YES == ignore) + break; + json_array_append_new (path, json_integer (fnum)); + root = json_array_get (root, fnum); + if (NULL == root) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:o}", + "error", "missing index in JSON", + "path", path); + ignore = GNUNET_YES; + break; + } + } + break; + case JNAV_RET_DATA: + { + void *where = va_arg (argp, void *); + size_t len = va_arg (argp, size_t); + const char *str; + int res; + + va_end(argp); + if (GNUNET_YES == ignore) + return GNUNET_NO; + str = json_string_value (root); + if (NULL == str) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:o}", + "error", + "string expected", + "path", + path); + return GNUNET_NO; + } + res = GNUNET_STRINGS_string_to_data (str, strlen (str), + where, len); + if (GNUNET_OK != res) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s,s:o}", + "error", + "malformed binary data in JSON", + "path", path); + return GNUNET_NO; + } + return GNUNET_YES; + } + break; + case JNAV_RET_DATA_VAR: + { + void **where = va_arg (argp, void **); + size_t *len = va_arg (argp, size_t *); + const char *str; + + va_end(argp); + if (GNUNET_YES == ignore) + return GNUNET_NO; + str = json_string_value (root); + if (NULL == str) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + *len = (strlen (str) * 5) / 8; + if (where != NULL) + { + int res; + *where = GNUNET_malloc (*len); + res = GNUNET_STRINGS_string_to_data (str, strlen (str), + *where, *len); + if (GNUNET_OK != res) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:o}", + "error", + "malformed binary data in JSON", + "path", path); + return GNUNET_NO; + } + } + return GNUNET_OK; + } + break; + case JNAV_RET_TYPED_JSON: + { + int typ = va_arg (argp, int); + const json_t **r_json = va_arg (argp, const json_t **); + + va_end(argp); + if (GNUNET_YES == ignore) + return GNUNET_NO; + if (typ != -1 && json_typeof (root) != typ) + { + /* FIXME: can't IGNORE this return value! */ + (void) TALER_MINT_reply_json_pack (connection, + MHD_HTTP_BAD_REQUEST, + "{s:s, s:i, s:i s:o}", + "error", "wrong JSON field type", + "type_expected", typ, + "type_actual", json_typeof (root), + "path", path); + return GNUNET_NO; + } + *r_json = root; + return GNUNET_OK; + } + break; + default: + GNUNET_assert (0); + } + } + GNUNET_assert (0); +} + + +/** + * 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_MINT_mhd_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_MINT_reply_arg_missing (connection, 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_MINT_reply_arg_invalid (connection, param_name)) + ? GNUNET_SYSERR : GNUNET_NO; + return GNUNET_OK; +} |