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Diffstat (limited to 'src/mhd/mhd_responses.c')
| -rw-r--r-- | src/mhd/mhd_responses.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/src/mhd/mhd_responses.c b/src/mhd/mhd_responses.c new file mode 100644 index 000000000..3642e7d54 --- /dev/null +++ b/src/mhd/mhd_responses.c @@ -0,0 +1,501 @@ +/* + 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_responses.c + * @brief API for generating HTTP replies + * @author Florian Dold + * @author Benedikt Mueller + * @author Christian Grothoff + */ +#include "platform.h" +#include <zlib.h> +#include "taler_util.h" +#include "taler_mhd_lib.h" + + +/** + * Enable checking signatures before we hand them out + * (even though we should have checked them before). + * So technically these checks are redundant, but good + * during testing. + */ +#define SANITY_CHECKS_ON 1 + + +/** + * Global options for response generation. + */ +static enum TALER_MHD_GlobalOptions TM_go; + + +/** + * Set global options for response generation + * within libtalermhd. + * + * @param go global options to use + */ +void +TALER_MHD_setup (enum TALER_MHD_GlobalOptions go) +{ + TM_go = go; +} + + +/** + * 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 +TALER_MHD_add_global_headers (struct MHD_Response *response) +{ + if (0 != (TM_go & TALER_MHD_GO_FORCE_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 +TALER_MHD_can_compress (struct MHD_Connection *connection) +{ + const char *ae; + const char *de; + + if (0 != (TM_go & TALER_MHD_GO_DISABLE_COMPRESSION)) + return MHD_NO; + 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 +TALER_MHD_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; +} + + +/** + * Make JSON response object. + * + * @param json the json object + * @return MHD response object + */ +struct MHD_Response * +TALER_MHD_make_json (const json_t *json) +{ + struct MHD_Response *resp; + char *json_str; + + json_str = json_dumps (json, + JSON_INDENT (2)); + if (NULL == json_str) + { + GNUNET_break (0); + return NULL; + } + resp = MHD_create_response_from_buffer (strlen (json_str), + json_str, + MHD_RESPMEM_MUST_FREE); + if (NULL == resp) + { + free (json_str); + GNUNET_break (0); + return NULL; + } + TALER_MHD_add_global_headers (resp); + GNUNET_break (MHD_YES == + MHD_add_response_header (resp, + MHD_HTTP_HEADER_CONTENT_TYPE, + "application/json")); + return resp; +} + + +/** + * 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 +TALER_MHD_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 == + TALER_MHD_can_compress (connection)) + comp = TALER_MHD_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; + } + TALER_MHD_add_global_headers (resp); + GNUNET_break (MHD_YES == + 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 +TALER_MHD_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 = TALER_MHD_reply_json (connection, + json, + response_code); + json_decref (json); + return ret; +} + + +/** + * Make JSON response object. + * + * @param fmt format string for pack + * @param ... varargs + * @return MHD response object + */ +struct MHD_Response * +TALER_MHD_make_json_pack (const char *fmt, + ...) +{ + json_t *json; + va_list argp; + struct MHD_Response *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 = TALER_MHD_make_json (json); + json_decref (json); + return ret; +} + + +/** + * Create a response indicating an internal error. + * + * @param ec error code to return + * @param hint hint about the internal error's nature + * @return a MHD response object + */ +struct MHD_Response * +TALER_MHD_make_error (enum TALER_ErrorCode ec, + const char *hint) +{ + return TALER_MHD_make_json_pack ("{s:I, s:s}", + "code", (json_int_t) ec, + "hint", hint); +} + + +/** + * Send a response indicating an error. + * + * @param connection the MHD connection to use + * @param ec error code uniquely identifying the error + * @param http_status HTTP status code to use + * @param hint human readable hint about the error + * @return a MHD result code + */ +int +TALER_MHD_reply_with_error (struct MHD_Connection *connection, + unsigned int http_status, + enum TALER_ErrorCode ec, + const char *hint) +{ + return TALER_MHD_reply_json_pack (connection, + http_status, + "{s:I, s:s}", + "code", (json_int_t) ec, + "hint", hint); +} + + +/** + * Send a response indicating that the request was too big. + * + * @param connection the MHD connection to use + * @return a MHD result code + */ +int +TALER_MHD_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; + TALER_MHD_add_global_headers (resp); + ret = MHD_queue_response (connection, + MHD_HTTP_REQUEST_ENTITY_TOO_LARGE, + resp); + MHD_destroy_response (resp); + return ret; +} + + +/** + * Function to call to handle the request by sending + * back a redirect to the AGPL source code. + * + * @param connection the MHD connection to handle + * @param url where to redirect for the sources + * @return MHD result code + */ +int +TALER_MHD_reply_agpl (struct MHD_Connection *connection, + const char *url) +{ + const char *agpl = + "This server is licensed under the Affero GPL. You will now be redirected to the source code."; + struct MHD_Response *response; + int ret; + + response = MHD_create_response_from_buffer (strlen (agpl), + (void *) agpl, + MHD_RESPMEM_PERSISTENT); + if (NULL == response) + { + GNUNET_break (0); + return MHD_NO; + } + TALER_MHD_add_global_headers (response); + GNUNET_break (MHD_YES == + MHD_add_response_header (response, + MHD_HTTP_HEADER_CONTENT_TYPE, + "text/plain")); + if (MHD_NO == + MHD_add_response_header (response, + MHD_HTTP_HEADER_LOCATION, + url)) + { + GNUNET_break (0); + MHD_destroy_response (response); + return MHD_NO; + } + ret = MHD_queue_response (connection, + MHD_HTTP_FOUND, + response); + MHD_destroy_response (response); + return ret; +} + + +/** + * Function to call to handle the request by sending + * back static data. + * + * @param rh context of the handler + * @param connection the MHD connection to handle + * @param http_status status code to return + * @param mime_type content-type to use + * @param body response payload + * @param body_size number of bytes in @a body + * @return MHD result code + */ +int +TALER_MHD_reply_static (struct MHD_Connection *connection, + unsigned int http_status, + const char *mime_type, + const char *body, + size_t body_size) +{ + struct MHD_Response *response; + int ret; + + response = MHD_create_response_from_buffer (body_size, + (void *) body, + MHD_RESPMEM_PERSISTENT); + if (NULL == response) + { + GNUNET_break (0); + return MHD_NO; + } + TALER_MHD_add_global_headers (response); + if (NULL != mime_type) + GNUNET_break (MHD_YES == + MHD_add_response_header (response, + MHD_HTTP_HEADER_CONTENT_TYPE, + mime_type)); + ret = MHD_queue_response (connection, + http_status, + response); + MHD_destroy_response (response); + return ret; +} + + +/* end of mhd_responses.c */ |