Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1372 insertions, 0 deletions

diff --git a/src/civetweb/include/civetweb.h b/src/civetweb/include/civetweb.h
new file mode 100644
index 000000000..6ddde4f2f
--- /dev/null
+++ b/src/civetweb/include/civetweb.h
@@ -0,0 +1,1372 @@
+/* Copyright (c) 2013-2017 the Civetweb developers
+ * Copyright (c) 2004-2013 Sergey Lyubka
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef CIVETWEB_HEADER_INCLUDED
+#define CIVETWEB_HEADER_INCLUDED
+
+#define CIVETWEB_VERSION "1.10"
+#define CIVETWEB_VERSION_MAJOR (1)
+#define CIVETWEB_VERSION_MINOR (10)
+#define CIVETWEB_VERSION_PATCH (0)
+#define CIVETWEB_VERSION_RELEASED
+
+#ifndef CIVETWEB_API
+#if defined(_WIN32)
+#if defined(CIVETWEB_DLL_EXPORTS)
+#define CIVETWEB_API __declspec(dllexport)
+#elif defined(CIVETWEB_DLL_IMPORTS)
+#define CIVETWEB_API __declspec(dllimport)
+#else
+#define CIVETWEB_API
+#endif
+#elif __GNUC__ >= 4
+#define CIVETWEB_API __attribute__((visibility("default")))
+#else
+#define CIVETWEB_API
+#endif
+#endif
+
+#include <stdio.h>
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+
+/* Initialize this library. This should be called once before any other
+ * function from this library. This function is not guaranteed to be
+ * thread safe.
+ * Parameters:
+ *   features: bit mask for features to be initialized.
+ * Return value:
+ *   initialized features
+ *   0: error
+ */
+CIVETWEB_API unsigned mg_init_library(unsigned features);
+
+
+/* Un-initialize this library.
+ * Return value:
+ *   0: error
+ */
+CIVETWEB_API unsigned mg_exit_library(void);
+
+
+struct mg_context;    /* Handle for the HTTP service itself */
+struct mg_connection; /* Handle for the individual connection */
+
+
+/* Maximum number of headers */
+#define MG_MAX_HEADERS (64)
+
+struct mg_header {
+	const char *name;  /* HTTP header name */
+	const char *value; /* HTTP header value */
+};
+
+
+/* This structure contains information about the HTTP request. */
+struct mg_request_info {
+	const char *request_method; /* "GET", "POST", etc */
+	const char *request_uri;    /* URL-decoded URI (absolute or relative,
+	                             * as in the request) */
+	const char *local_uri;      /* URL-decoded URI (relative). Can be NULL
+	                             * if the request_uri does not address a
+	                             * resource at the server host. */
+#if defined(MG_LEGACY_INTERFACE)
+	const char *uri; /* Deprecated: use local_uri instead */
+#endif
+	const char *http_version; /* E.g. "1.0", "1.1" */
+	const char *query_string; /* URL part after '?', not including '?', or
+	                             NULL */
+	const char *remote_user;  /* Authenticated user, or NULL if no auth
+	                             used */
+	char remote_addr[48];     /* Client's IP address as a string. */
+
+#if defined(MG_LEGACY_INTERFACE)
+	long remote_ip; /* Client's IP address. Deprecated: use remote_addr instead
+	                   */
+#endif
+
+	long long content_length; /* Length (in bytes) of the request body,
+	                             can be -1 if no length was given. */
+	int remote_port;          /* Client's port */
+	int is_ssl;               /* 1 if SSL-ed, 0 if not */
+	void *user_data;          /* User data pointer passed to mg_start() */
+	void *conn_data;          /* Connection-specific user data */
+
+	int num_headers; /* Number of HTTP headers */
+	struct mg_header
+	    http_headers[MG_MAX_HEADERS]; /* Allocate maximum headers */
+
+	struct mg_client_cert *client_cert; /* Client certificate information */
+
+	const char *acceptedWebSocketSubprotocol; /* websocket subprotocol,
+	                                           * accepted during handshake */
+};
+
+
+/* This structure contains information about the HTTP request. */
+/* This structure may be extended in future versions. */
+struct mg_response_info {
+	int status_code;          /* E.g. 200 */
+	const char *status_text;  /* E.g. "OK" */
+	const char *http_version; /* E.g. "1.0", "1.1" */
+
+	long long content_length; /* Length (in bytes) of the request body,
+	                             can be -1 if no length was given. */
+
+	int num_headers; /* Number of HTTP headers */
+	struct mg_header
+	    http_headers[MG_MAX_HEADERS]; /* Allocate maximum headers */
+};
+
+
+/* Client certificate information (part of mg_request_info) */
+/* New nomenclature. */
+struct mg_client_cert {
+	const char *subject;
+	const char *issuer;
+	const char *serial;
+	const char *finger;
+};
+
+/* Old nomenclature. */
+struct client_cert {
+	const char *subject;
+	const char *issuer;
+	const char *serial;
+	const char *finger;
+};
+
+
+/* This structure needs to be passed to mg_start(), to let civetweb know
+   which callbacks to invoke. For a detailed description, see
+   https://github.com/civetweb/civetweb/blob/master/docs/UserManual.md */
+struct mg_callbacks {
+	/* Called when civetweb has received new HTTP request.
+	   If the callback returns one, it must process the request
+	   by sending valid HTTP headers and a body. Civetweb will not do
+	   any further processing. Otherwise it must return zero.
+	   Note that since V1.7 the "begin_request" function is called
+	   before an authorization check. If an authorization check is
+	   required, use a request_handler instead.
+	   Return value:
+	     0: civetweb will process the request itself. In this case,
+	        the callback must not send any data to the client.
+	     1-999: callback already processed the request. Civetweb will
+	            not send any data after the callback returned. The
+	            return code is stored as a HTTP status code for the
+	            access log. */
+	int (*begin_request)(struct mg_connection *);
+
+	/* Called when civetweb has finished processing request. */
+	void (*end_request)(const struct mg_connection *, int reply_status_code);
+
+	/* Called when civetweb is about to log a message. If callback returns
+	   non-zero, civetweb does not log anything. */
+	int (*log_message)(const struct mg_connection *, const char *message);
+
+	/* Called when civetweb is about to log access. If callback returns
+	   non-zero, civetweb does not log anything. */
+	int (*log_access)(const struct mg_connection *, const char *message);
+
+	/* Called when civetweb initializes SSL library.
+	   Parameters:
+	     user_data: parameter user_data passed when starting the server.
+	   Return value:
+	     0: civetweb will set up the SSL certificate.
+	     1: civetweb assumes the callback already set up the certificate.
+	    -1: initializing ssl fails. */
+	int (*init_ssl)(void *ssl_context, void *user_data);
+
+#if defined(MG_LEGACY_INTERFACE)
+	/* Called when websocket request is received, before websocket handshake.
+	   Return value:
+	     0: civetweb proceeds with websocket handshake.
+	     1: connection is closed immediately.
+	   This callback is deprecated: Use mg_set_websocket_handler instead. */
+	int (*websocket_connect)(const struct mg_connection *);
+
+	/* Called when websocket handshake is successfully completed, and
+	   connection is ready for data exchange.
+	   This callback is deprecated: Use mg_set_websocket_handler instead. */
+	void (*websocket_ready)(struct mg_connection *);
+
+	/* Called when data frame has been received from the client.
+	   Parameters:
+	     bits: first byte of the websocket frame, see websocket RFC at
+	           http://tools.ietf.org/html/rfc6455, section 5.2
+	     data, data_len: payload, with mask (if any) already applied.
+	   Return value:
+	     1: keep this websocket connection open.
+	     0: close this websocket connection.
+	   This callback is deprecated: Use mg_set_websocket_handler instead. */
+	int (*websocket_data)(struct mg_connection *,
+	                      int bits,
+	                      char *data,
+	                      size_t data_len);
+#endif /* MG_LEGACY_INTERFACE */
+
+	/* Called when civetweb is closing a connection.  The per-context mutex is
+	   locked when this is invoked.
+
+	   Websockets:
+	   Before mg_set_websocket_handler has been added, it was primarily useful
+	   for noting when a websocket is closing, and used to remove it from any
+	   application-maintained list of clients.
+	   Using this callback for websocket connections is deprecated: Use
+	   mg_set_websocket_handler instead.
+
+	   Connection specific data:
+	   If memory has been allocated for the connection specific user data
+	   (mg_request_info->conn_data, mg_get_user_connection_data),
+	   this is the last chance to free it.
+	*/
+	void (*connection_close)(const struct mg_connection *);
+
+#if defined(MG_USE_OPEN_FILE)
+	/* Note: The "file in memory" feature is a deletion candidate, since
+	 * it complicates the code, and does not add any value compared to
+	 * "mg_add_request_handler".
+	 * See this discussion thread:
+	 * https://groups.google.com/forum/#!topic/civetweb/h9HT4CmeYqI
+	 * If you disagree, if there is any situation this is indeed useful
+	 * and cannot trivially be replaced by another existing feature,
+	 * please contribute to this discussion during the next 3 month
+	 * (till end of April 2017), otherwise this feature might be dropped
+	 * in future releases. */
+
+	/* Called when civetweb tries to open a file. Used to intercept file open
+	   calls, and serve file data from memory instead.
+	   Parameters:
+	      path:     Full path to the file to open.
+	      data_len: Placeholder for the file size, if file is served from
+	                memory.
+	   Return value:
+	     NULL: do not serve file from memory, proceed with normal file open.
+	     non-NULL: pointer to the file contents in memory. data_len must be
+	       initialized with the size of the memory block. */
+	const char *(*open_file)(const struct mg_connection *,
+	                         const char *path,
+	                         size_t *data_len);
+#endif
+
+	/* Called when civetweb is about to serve Lua server page, if
+	   Lua support is enabled.
+	   Parameters:
+	     lua_context: "lua_State *" pointer. */
+	void (*init_lua)(const struct mg_connection *, void *lua_context);
+
+#if defined(MG_LEGACY_INTERFACE)
+	/* Called when civetweb has uploaded a file to a temporary directory as a
+	   result of mg_upload() call.
+	   Note that mg_upload is deprecated. Use mg_handle_form_request instead.
+	   Parameters:
+	     file_name: full path name to the uploaded file. */
+	void (*upload)(struct mg_connection *, const char *file_name);
+#endif
+
+	/* Called when civetweb is about to send HTTP error to the client.
+	   Implementing this callback allows to create custom error pages.
+	   Parameters:
+	     status: HTTP error status code.
+	   Return value:
+	     1: run civetweb error handler.
+	     0: callback already handled the error. */
+	int (*http_error)(struct mg_connection *, int status);
+
+	/* Called after civetweb context has been created, before requests
+	   are processed.
+	   Parameters:
+	     ctx: context handle */
+	void (*init_context)(const struct mg_context *ctx);
+
+	/* Called when a new worker thread is initialized.
+	   Parameters:
+	     ctx: context handle
+	     thread_type:
+	       0 indicates the master thread
+	       1 indicates a worker thread handling client connections
+	       2 indicates an internal helper thread (timer thread)
+	       */
+	void (*init_thread)(const struct mg_context *ctx, int thread_type);
+
+	/* Called when civetweb context is deleted.
+	   Parameters:
+	     ctx: context handle */
+	void (*exit_context)(const struct mg_context *ctx);
+
+	/* Called when initializing a new connection object.
+	 * Can be used to initialize the connection specific user data
+	 * (mg_request_info->conn_data, mg_get_user_connection_data).
+	 * When the callback is called, it is not yet known if a
+	 * valid HTTP(S) request will be made.
+	 * Parameters:
+	 *   conn: not yet fully initialized connection object
+	 *   conn_data: output parameter, set to initialize the
+	 *              connection specific user data
+	 * Return value:
+	 *   must be 0
+	 *   Otherwise, the result is undefined
+	 */
+	int (*init_connection)(const struct mg_connection *conn, void **conn_data);
+};
+
+
+/* Start web server.
+
+   Parameters:
+     callbacks: mg_callbacks structure with user-defined callbacks.
+     options: NULL terminated list of option_name, option_value pairs that
+              specify Civetweb configuration parameters.
+
+   Side-effects: on UNIX, ignores SIGCHLD and SIGPIPE signals. If custom
+      processing is required for these, signal handlers must be set up
+      after calling mg_start().
+
+
+   Example:
+     const char *options[] = {
+       "document_root", "/var/www",
+       "listening_ports", "80,443s",
+       NULL
+     };
+     struct mg_context *ctx = mg_start(&my_func, NULL, options);
+
+   Refer to https://github.com/civetweb/civetweb/blob/master/docs/UserManual.md
+   for the list of valid option and their possible values.
+
+   Return:
+     web server context, or NULL on error. */
+CIVETWEB_API struct mg_context *mg_start(const struct mg_callbacks *callbacks,
+                                         void *user_data,
+                                         const char **configuration_options);
+
+
+/* Stop the web server.
+
+   Must be called last, when an application wants to stop the web server and
+   release all associated resources. This function blocks until all Civetweb
+   threads are stopped. Context pointer becomes invalid. */
+CIVETWEB_API void mg_stop(struct mg_context *);
+
+
+/* mg_request_handler
+
+   Called when a new request comes in.  This callback is URI based
+   and configured with mg_set_request_handler().
+
+   Parameters:
+      conn: current connection information.
+      cbdata: the callback data configured with mg_set_request_handler().
+   Returns:
+      0: the handler could not handle the request, so fall through.
+      1 - 999: the handler processed the request. The return code is
+               stored as a HTTP status code for the access log. */
+typedef int (*mg_request_handler)(struct mg_connection *conn, void *cbdata);
+
+
+/* mg_set_request_handler
+
+   Sets or removes a URI mapping for a request handler.
+   This function uses mg_lock_context internally.
+
+   URI's are ordered and prefixed URI's are supported. For example,
+   consider two URIs: /a/b and /a
+           /a   matches /a
+           /a/b matches /a/b
+           /a/c matches /a
+
+   Parameters:
+      ctx: server context
+      uri: the URI (exact or pattern) for the handler
+      handler: the callback handler to use when the URI is requested.
+               If NULL, an already registered handler for this URI will
+               be removed.
+               The URI used to remove a handler must match exactly the
+               one used to register it (not only a pattern match).
+      cbdata: the callback data to give to the handler when it is called. */
+CIVETWEB_API void mg_set_request_handler(struct mg_context *ctx,
+                                         const char *uri,
+                                         mg_request_handler handler,
+                                         void *cbdata);
+
+
+/* Callback types for websocket handlers in C/C++.
+
+   mg_websocket_connect_handler
+       Is called when the client intends to establish a websocket connection,
+       before websocket handshake.
+       Return value:
+         0: civetweb proceeds with websocket handshake.
+         1: connection is closed immediately.
+
+   mg_websocket_ready_handler
+       Is called when websocket handshake is successfully completed, and
+       connection is ready for data exchange.
+
+   mg_websocket_data_handler
+       Is called when a data frame has been received from the client.
+       Parameters:
+         bits: first byte of the websocket frame, see websocket RFC at
+               http://tools.ietf.org/html/rfc6455, section 5.2
+         data, data_len: payload, with mask (if any) already applied.
+       Return value:
+         1: keep this websocket connection open.
+         0: close this websocket connection.
+
+   mg_connection_close_handler
+       Is called, when the connection is closed.*/
+typedef int (*mg_websocket_connect_handler)(const struct mg_connection *,
+                                            void *);
+typedef void (*mg_websocket_ready_handler)(struct mg_connection *, void *);
+typedef int (*mg_websocket_data_handler)(struct mg_connection *,
+                                         int,
+                                         char *,
+                                         size_t,
+                                         void *);
+typedef void (*mg_websocket_close_handler)(const struct mg_connection *,
+                                           void *);
+
+/* struct mg_websocket_subprotocols
+ *
+ * List of accepted subprotocols
+ */
+struct mg_websocket_subprotocols {
+	int nb_subprotocols;
+	char **subprotocols;
+};
+
+/* mg_set_websocket_handler
+
+   Set or remove handler functions for websocket connections.
+   This function works similar to mg_set_request_handler - see there. */
+CIVETWEB_API void
+mg_set_websocket_handler(struct mg_context *ctx,
+                         const char *uri,
+                         mg_websocket_connect_handler connect_handler,
+                         mg_websocket_ready_handler ready_handler,
+                         mg_websocket_data_handler data_handler,
+                         mg_websocket_close_handler close_handler,
+                         void *cbdata);
+
+/* mg_set_websocket_handler
+
+   Set or remove handler functions for websocket connections.
+   This function works similar to mg_set_request_handler - see there. */
+CIVETWEB_API void mg_set_websocket_handler_with_subprotocols(
+    struct mg_context *ctx,
+    const char *uri,
+    struct mg_websocket_subprotocols *subprotocols,
+    mg_websocket_connect_handler connect_handler,
+    mg_websocket_ready_handler ready_handler,
+    mg_websocket_data_handler data_handler,
+    mg_websocket_close_handler close_handler,
+    void *cbdata);
+
+
+/* mg_authorization_handler
+
+   Callback function definition for mg_set_auth_handler
+
+   Parameters:
+      conn: current connection information.
+      cbdata: the callback data configured with mg_set_request_handler().
+   Returns:
+      0: access denied
+      1: access granted
+ */
+typedef int (*mg_authorization_handler)(struct mg_connection *conn,
+                                        void *cbdata);
+
+
+/* mg_set_auth_handler
+
+   Sets or removes a URI mapping for an authorization handler.
+   This function works similar to mg_set_request_handler - see there. */
+CIVETWEB_API void mg_set_auth_handler(struct mg_context *ctx,
+                                      const char *uri,
+                                      mg_authorization_handler handler,
+                                      void *cbdata);
+
+
+/* Get the value of particular configuration parameter.
+   The value returned is read-only. Civetweb does not allow changing
+   configuration at run time.
+   If given parameter name is not valid, NULL is returned. For valid
+   names, return value is guaranteed to be non-NULL. If parameter is not
+   set, zero-length string is returned. */
+CIVETWEB_API const char *mg_get_option(const struct mg_context *ctx,
+                                       const char *name);
+
+
+/* Get context from connection. */
+CIVETWEB_API struct mg_context *
+mg_get_context(const struct mg_connection *conn);
+
+
+/* Get user data passed to mg_start from context. */
+CIVETWEB_API void *mg_get_user_data(const struct mg_context *ctx);
+
+
+/* Set user data for the current connection. */
+CIVETWEB_API void mg_set_user_connection_data(struct mg_connection *conn,
+                                              void *data);
+
+
+/* Get user data set for the current connection. */
+CIVETWEB_API void *
+mg_get_user_connection_data(const struct mg_connection *conn);
+
+
+/* Get a formatted link corresponding to the current request
+
+   Parameters:
+      conn: current connection information.
+      buf: string buffer (out)
+      buflen: length of the string buffer
+   Returns:
+      <0: error
+      >=0: ok */
+CIVETWEB_API int
+mg_get_request_link(const struct mg_connection *conn, char *buf, size_t buflen);
+
+
+#if defined(MG_LEGACY_INTERFACE)
+/* Return array of strings that represent valid configuration options.
+   For each option, option name and default value is returned, i.e. the
+   number of entries in the array equals to number_of_options x 2.
+   Array is NULL terminated. */
+/* Deprecated: Use mg_get_valid_options instead. */
+CIVETWEB_API const char **mg_get_valid_option_names(void);
+#endif
+
+
+struct mg_option {
+	const char *name;
+	int type;
+	const char *default_value;
+};
+
+/* Old nomenclature */
+enum {
+	CONFIG_TYPE_UNKNOWN = 0x0,
+	CONFIG_TYPE_NUMBER = 0x1,
+	CONFIG_TYPE_STRING = 0x2,
+	CONFIG_TYPE_FILE = 0x3,
+	CONFIG_TYPE_DIRECTORY = 0x4,
+	CONFIG_TYPE_BOOLEAN = 0x5,
+	CONFIG_TYPE_EXT_PATTERN = 0x6,
+	CONFIG_TYPE_STRING_LIST = 0x7,
+	CONFIG_TYPE_STRING_MULTILINE = 0x8
+};
+
+/* New nomenclature */
+enum {
+	MG_CONFIG_TYPE_UNKNOWN = 0x0,
+	MG_CONFIG_TYPE_NUMBER = 0x1,
+	MG_CONFIG_TYPE_STRING = 0x2,
+	MG_CONFIG_TYPE_FILE = 0x3,
+	MG_CONFIG_TYPE_DIRECTORY = 0x4,
+	MG_CONFIG_TYPE_BOOLEAN = 0x5,
+	MG_CONFIG_TYPE_EXT_PATTERN = 0x6,
+	MG_CONFIG_TYPE_STRING_LIST = 0x7,
+	MG_CONFIG_TYPE_STRING_MULTILINE = 0x8
+};
+
+/* Return array of struct mg_option, representing all valid configuration
+   options of civetweb.c.
+   The array is terminated by a NULL name option. */
+CIVETWEB_API const struct mg_option *mg_get_valid_options(void);
+
+
+struct mg_server_ports {
+	int protocol;    /* 1 = IPv4, 2 = IPv6, 3 = both */
+	int port;        /* port number */
+	int is_ssl;      /* https port: 0 = no, 1 = yes */
+	int is_redirect; /* redirect all requests: 0 = no, 1 = yes */
+	int _reserved1;
+	int _reserved2;
+	int _reserved3;
+	int _reserved4;
+};
+
+
+/* Get the list of ports that civetweb is listening on.
+   The parameter size is the size of the ports array in elements.
+   The caller is responsibility to allocate the required memory.
+   This function returns the number of struct mg_server_ports elements
+   filled in, or <0 in case of an error. */
+CIVETWEB_API int mg_get_server_ports(const struct mg_context *ctx,
+                                     int size,
+                                     struct mg_server_ports *ports);
+
+
+#if defined(MG_LEGACY_INTERFACE)
+/* Deprecated: Use mg_get_server_ports instead. */
+CIVETWEB_API size_t
+mg_get_ports(const struct mg_context *ctx, size_t size, int *ports, int *ssl);
+#endif
+
+
+/* Add, edit or delete the entry in the passwords file.
+ *
+ * This function allows an application to manipulate .htpasswd files on the
+ * fly by adding, deleting and changing user records. This is one of the
+ * several ways of implementing authentication on the server side. For another,
+ * cookie-based way please refer to the examples/chat in the source tree.
+ *
+ * Parameter:
+ *   passwords_file_name: Path and name of a file storing multiple passwords
+ *   realm: HTTP authentication realm (authentication domain) name
+ *   user: User name
+ *   password:
+ *     If password is not NULL, entry modified or added.
+ *     If password is NULL, entry is deleted.
+ *
+ *  Return:
+ *    1 on success, 0 on error.
+ */
+CIVETWEB_API int mg_modify_passwords_file(const char *passwords_file_name,
+                                          const char *realm,
+                                          const char *user,
+                                          const char *password);
+
+
+/* Return information associated with the request.
+ * Use this function to implement a server and get data about a request
+ * from a HTTP/HTTPS client.
+ * Note: Before CivetWeb 1.10, this function could be used to read
+ * a response from a server, when implementing a client, although the
+ * values were never returned in appropriate mg_request_info elements.
+ * It is strongly advised to use mg_get_response_info for clients.
+ */
+CIVETWEB_API const struct mg_request_info *
+mg_get_request_info(const struct mg_connection *);
+
+/* Return the local address (server side) of the socket for a connection */
+CIVETWEB_API struct sockaddr *
+mg_get_local_addr(struct mg_connection *);
+
+/* Return information associated with a HTTP/HTTPS response.
+ * Use this function in a client, to check the response from
+ * the server. */
+CIVETWEB_API const struct mg_response_info *
+mg_get_response_info(const struct mg_connection *);
+
+
+/* Send data to the client.
+   Return:
+    0   when the connection has been closed
+    -1  on error
+    >0  number of bytes written on success */
+CIVETWEB_API int mg_write(struct mg_connection *, const void *buf, size_t len);
+
+
+/* Send data to a websocket client wrapped in a websocket frame.  Uses
+   mg_lock_connection to ensure that the transmission is not interrupted,
+   i.e., when the application is proactively communicating and responding to
+   a request simultaneously.
+
+   Send data to a websocket client wrapped in a websocket frame.
+   This function is available when civetweb is compiled with -DUSE_WEBSOCKET
+
+   Return:
+    0   when the connection has been closed
+    -1  on error
+    >0  number of bytes written on success */
+CIVETWEB_API int mg_websocket_write(struct mg_connection *conn,
+                                    int opcode,
+                                    const char *data,
+                                    size_t data_len);
+
+
+/* Send data to a websocket server wrapped in a masked websocket frame.  Uses
+   mg_lock_connection to ensure that the transmission is not interrupted,
+   i.e., when the application is proactively communicating and responding to
+   a request simultaneously.
+
+   Send data to a websocket server wrapped in a masked websocket frame.
+   This function is available when civetweb is compiled with -DUSE_WEBSOCKET
+
+   Return:
+    0   when the connection has been closed
+    -1  on error
+    >0  number of bytes written on success */
+CIVETWEB_API int mg_websocket_client_write(struct mg_connection *conn,
+                                           int opcode,
+                                           const char *data,
+                                           size_t data_len);
+
+
+/* Blocks until unique access is obtained to this connection. Intended for use
+   with websockets only.
+   Invoke this before mg_write or mg_printf when communicating with a
+   websocket if your code has server-initiated communication as well as
+   communication in direct response to a message. */
+CIVETWEB_API void mg_lock_connection(struct mg_connection *conn);
+CIVETWEB_API void mg_unlock_connection(struct mg_connection *conn);
+
+
+#if defined(MG_LEGACY_INTERFACE)
+#define mg_lock mg_lock_connection
+#define mg_unlock mg_unlock_connection
+#endif
+
+
+/* Lock server context.  This lock may be used to protect resources
+   that are shared between different connection/worker threads. */
+CIVETWEB_API void mg_lock_context(struct mg_context *ctx);
+CIVETWEB_API void mg_unlock_context(struct mg_context *ctx);
+
+
+/* Opcodes, from http://tools.ietf.org/html/rfc6455 */
+/* Old nomenclature */
+enum {
+	WEBSOCKET_OPCODE_CONTINUATION = 0x0,
+	WEBSOCKET_OPCODE_TEXT = 0x1,
+	WEBSOCKET_OPCODE_BINARY = 0x2,
+	WEBSOCKET_OPCODE_CONNECTION_CLOSE = 0x8,
+	WEBSOCKET_OPCODE_PING = 0x9,
+	WEBSOCKET_OPCODE_PONG = 0xa
+};
+
+/* New nomenclature */
+enum {
+	MG_WEBSOCKET_OPCODE_CONTINUATION = 0x0,
+	MG_WEBSOCKET_OPCODE_TEXT = 0x1,
+	MG_WEBSOCKET_OPCODE_BINARY = 0x2,
+	MG_WEBSOCKET_OPCODE_CONNECTION_CLOSE = 0x8,
+	MG_WEBSOCKET_OPCODE_PING = 0x9,
+	MG_WEBSOCKET_OPCODE_PONG = 0xa
+};
+
+/* Macros for enabling compiler-specific checks for printf-like arguments. */
+#undef PRINTF_FORMAT_STRING
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+#include <sal.h>
+#if defined(_MSC_VER) && _MSC_VER > 1400
+#define PRINTF_FORMAT_STRING(s) _Printf_format_string_ s
+#else
+#define PRINTF_FORMAT_STRING(s) __format_string s
+#endif
+#else
+#define PRINTF_FORMAT_STRING(s) s
+#endif
+
+#ifdef __GNUC__
+#define PRINTF_ARGS(x, y) __attribute__((format(printf, x, y)))
+#else
+#define PRINTF_ARGS(x, y)
+#endif
+
+
+/* Send data to the client using printf() semantics.
+   Works exactly like mg_write(), but allows to do message formatting. */
+CIVETWEB_API int mg_printf(struct mg_connection *,
+                           PRINTF_FORMAT_STRING(const char *fmt),
+                           ...) PRINTF_ARGS(2, 3);
+
+
+/* Send a part of the message body, if chunked transfer encoding is set.
+ * Only use this function after sending a complete HTTP request or response
+ * header with "Transfer-Encoding: chunked" set. */
+CIVETWEB_API int mg_send_chunk(struct mg_connection *conn,
+                               const char *chunk,
+                               unsigned int chunk_len);
+
+
+/* Send contents of the entire file together with HTTP headers. */
+CIVETWEB_API void mg_send_file(struct mg_connection *conn, const char *path);
+
+
+/* Send HTTP error reply. */
+CIVETWEB_API void mg_send_http_error(struct mg_connection *conn,
+                                     int status_code,
+                                     PRINTF_FORMAT_STRING(const char *fmt),
+                                     ...) PRINTF_ARGS(3, 4);
+
+
+/* Send HTTP digest access authentication request.
+ * Browsers will send a user name and password in their next request, showing
+ * an authentication dialog if the password is not stored.
+ * Parameters:
+ *   conn: Current connection handle.
+ *   realm: Authentication realm. If NULL is supplied, the sever domain
+ *          set in the authentication_domain configuration is used.
+ * Return:
+ *   < 0   Error
+ */
+CIVETWEB_API int
+mg_send_digest_access_authentication_request(struct mg_connection *conn,
+                                             const char *realm);
+
+
+/* Check if the current request has a valid authentication token set.
+ * A file is used to provide a list of valid user names, realms and
+ * password hashes. The file can be created and modified using the
+ * mg_modify_passwords_file API function.
+ * Parameters:
+ *   conn: Current connection handle.
+ *   realm: Authentication realm. If NULL is supplied, the sever domain
+ *          set in the authentication_domain configuration is used.
+ *   filename: Path and name of a file storing multiple password hashes.
+ * Return:
+ *   > 0   Valid authentication
+ *   0     Invalid authentication
+ *   < 0   Error (all values < 0 should be considered as invalid
+ *         authentication, future error codes will have negative
+ *         numbers)
+ *   -1    Parameter error
+ *   -2    File not found
+ */
+CIVETWEB_API int
+mg_check_digest_access_authentication(struct mg_connection *conn,
+                                      const char *realm,
+                                      const char *filename);
+
+
+/* Send contents of the entire file together with HTTP headers.
+ * Parameters:
+ *   conn: Current connection handle.
+ *   path: Full path to the file to send.
+ *   mime_type: Content-Type for file.  NULL will cause the type to be
+ *              looked up by the file extension.
+ */
+CIVETWEB_API void mg_send_mime_file(struct mg_connection *conn,
+                                    const char *path,
+                                    const char *mime_type);
+
+
+/* Send contents of the entire file together with HTTP headers.
+   Parameters:
+     conn: Current connection information.
+     path: Full path to the file to send.
+     mime_type: Content-Type for file.  NULL will cause the type to be
+                looked up by the file extension.
+     additional_headers: Additional custom header fields appended to the header.
+                         Each header should start with an X-, to ensure it is
+                         not included twice.
+                         NULL does not append anything.
+*/
+CIVETWEB_API void mg_send_mime_file2(struct mg_connection *conn,
+                                     const char *path,
+                                     const char *mime_type,
+                                     const char *additional_headers);
+
+
+/* Store body data into a file. */
+CIVETWEB_API long long mg_store_body(struct mg_connection *conn,
+                                     const char *path);
+/* Read entire request body and store it in a file "path".
+   Return:
+     < 0   Error
+     >= 0  Number of bytes stored in file "path".
+*/
+
+
+/* Read data from the remote end, return number of bytes read.
+   Return:
+     0     connection has been closed by peer. No more data could be read.
+     < 0   read error. No more data could be read from the connection.
+     > 0   number of bytes read into the buffer. */
+CIVETWEB_API int mg_read(struct mg_connection *, void *buf, size_t len);
+
+
+/* Get the value of particular HTTP header.
+
+   This is a helper function. It traverses request_info->http_headers array,
+   and if the header is present in the array, returns its value. If it is
+   not present, NULL is returned. */
+CIVETWEB_API const char *mg_get_header(const struct mg_connection *,
+                                       const char *name);
+
+
+/* Get a value of particular form variable.
+
+   Parameters:
+     data: pointer to form-uri-encoded buffer. This could be either POST data,
+           or request_info.query_string.
+     data_len: length of the encoded data.
+     var_name: variable name to decode from the buffer
+     dst: destination buffer for the decoded variable
+     dst_len: length of the destination buffer
+
+   Return:
+     On success, length of the decoded variable.
+     On error:
+        -1 (variable not found).
+        -2 (destination buffer is NULL, zero length or too small to hold the
+            decoded variable).
+
+   Destination buffer is guaranteed to be '\0' - terminated if it is not
+   NULL or zero length. */
+CIVETWEB_API int mg_get_var(const char *data,
+                            size_t data_len,
+                            const char *var_name,
+                            char *dst,
+                            size_t dst_len);
+
+
+/* Get a value of particular form variable.
+
+   Parameters:
+     data: pointer to form-uri-encoded buffer. This could be either POST data,
+           or request_info.query_string.
+     data_len: length of the encoded data.
+     var_name: variable name to decode from the buffer
+     dst: destination buffer for the decoded variable
+     dst_len: length of the destination buffer
+     occurrence: which occurrence of the variable, 0 is the first, 1 the
+                 second...
+                this makes it possible to parse a query like
+                b=x&a=y&a=z which will have occurrence values b:0, a:0 and a:1
+
+   Return:
+     On success, length of the decoded variable.
+     On error:
+        -1 (variable not found).
+        -2 (destination buffer is NULL, zero length or too small to hold the
+            decoded variable).
+
+   Destination buffer is guaranteed to be '\0' - terminated if it is not
+   NULL or zero length. */
+CIVETWEB_API int mg_get_var2(const char *data,
+                             size_t data_len,
+                             const char *var_name,
+                             char *dst,
+                             size_t dst_len,
+                             size_t occurrence);
+
+
+/* Fetch value of certain cookie variable into the destination buffer.
+
+   Destination buffer is guaranteed to be '\0' - terminated. In case of
+   failure, dst[0] == '\0'. Note that RFC allows many occurrences of the same
+   parameter. This function returns only first occurrence.
+
+   Return:
+     On success, value length.
+     On error:
+        -1 (either "Cookie:" header is not present at all or the requested
+            parameter is not found).
+        -2 (destination buffer is NULL, zero length or too small to hold the
+            value). */
+CIVETWEB_API int mg_get_cookie(const char *cookie,
+                               const char *var_name,
+                               char *buf,
+                               size_t buf_len);
+
+
+/* Download data from the remote web server.
+     host: host name to connect to, e.g. "foo.com", or "10.12.40.1".
+     port: port number, e.g. 80.
+     use_ssl: wether to use SSL connection.
+     error_buffer, error_buffer_size: error message placeholder.
+     request_fmt,...: HTTP request.
+   Return:
+     On success, valid pointer to the new connection, suitable for mg_read().
+     On error, NULL. error_buffer contains error message.
+   Example:
+     char ebuf[100];
+     struct mg_connection *conn;
+     conn = mg_download("google.com", 80, 0, ebuf, sizeof(ebuf),
+                        "%s", "GET / HTTP/1.0\r\nHost: google.com\r\n\r\n");
+ */
+CIVETWEB_API struct mg_connection *
+mg_download(const char *host,
+            int port,
+            int use_ssl,
+            char *error_buffer,
+            size_t error_buffer_size,
+            PRINTF_FORMAT_STRING(const char *request_fmt),
+            ...) PRINTF_ARGS(6, 7);
+
+
+/* Close the connection opened by mg_download(). */
+CIVETWEB_API void mg_close_connection(struct mg_connection *conn);
+
+
+#if defined(MG_LEGACY_INTERFACE)
+/* File upload functionality. Each uploaded file gets saved into a temporary
+   file and MG_UPLOAD event is sent.
+   Return number of uploaded files.
+   Deprecated: Use mg_handle_form_request instead. */
+CIVETWEB_API int mg_upload(struct mg_connection *conn,
+                           const char *destination_dir);
+#endif
+
+
+/* This structure contains callback functions for handling form fields.
+   It is used as an argument to mg_handle_form_request. */
+struct mg_form_data_handler {
+	/* This callback function is called, if a new field has been found.
+	 * The return value of this callback is used to define how the field
+	 * should be processed.
+	 *
+	 * Parameters:
+	 *   key: Name of the field ("name" property of the HTML input field).
+	 *   filename: Name of a file to upload, at the client computer.
+	 *             Only set for input fields of type "file", otherwise NULL.
+	 *   path: Output parameter: File name (incl. path) to store the file
+	 *         at the server computer. Only used if FORM_FIELD_STORAGE_STORE
+	 *         is returned by this callback. Existing files will be
+	 *         overwritten.
+	 *   pathlen: Length of the buffer for path.
+	 *   user_data: Value of the member user_data of mg_form_data_handler
+	 *
+	 * Return value:
+	 *   The callback must return the intended storage for this field
+	 *   (See FORM_FIELD_STORAGE_*).
+	 */
+	int (*field_found)(const char *key,
+	                   const char *filename,
+	                   char *path,
+	                   size_t pathlen,
+	                   void *user_data);
+
+	/* If the "field_found" callback returned FORM_FIELD_STORAGE_GET,
+	 * this callback will receive the field data.
+	 *
+	 * Parameters:
+	 *   key: Name of the field ("name" property of the HTML input field).
+	 *   value: Value of the input field.
+	 *   user_data: Value of the member user_data of mg_form_data_handler
+	 *
+	 * Return value:
+	 *   TODO: Needs to be defined.
+	 */
+	int (*field_get)(const char *key,
+	                 const char *value,
+	                 size_t valuelen,
+	                 void *user_data);
+
+	/* If the "field_found" callback returned FORM_FIELD_STORAGE_STORE,
+	 * the data will be stored into a file. If the file has been written
+	 * successfully, this callback will be called. This callback will
+	 * not be called for only partially uploaded files. The
+	 * mg_handle_form_request function will either store the file completely
+	 * and call this callback, or it will remove any partial content and
+	 * not call this callback function.
+	 *
+	 * Parameters:
+	 *   path: Path of the file stored at the server.
+	 *   file_size: Size of the stored file in bytes.
+	 *   user_data: Value of the member user_data of mg_form_data_handler
+	 *
+	 * Return value:
+	 *   TODO: Needs to be defined.
+	 */
+	int (*field_store)(const char *path, long long file_size, void *user_data);
+
+	/* User supplied argument, passed to all callback functions. */
+	void *user_data;
+};
+
+
+/* Return values definition for the "field_found" callback in
+ * mg_form_data_handler. */
+/* Old nomenclature */
+enum {
+	/* Skip this field (neither get nor store it). Continue with the
+     * next field. */
+	FORM_FIELD_STORAGE_SKIP = 0x0,
+	/* Get the field value. */
+	FORM_FIELD_STORAGE_GET = 0x1,
+	/* Store the field value into a file. */
+	FORM_FIELD_STORAGE_STORE = 0x2,
+	/* Stop parsing this request. Skip the remaining fields. */
+	FORM_FIELD_STORAGE_ABORT = 0x10
+};
+
+/* New nomenclature */
+enum {
+	/* Skip this field (neither get nor store it). Continue with the
+     * next field. */
+	MG_FORM_FIELD_STORAGE_SKIP = 0x0,
+	/* Get the field value. */
+	MG_FORM_FIELD_STORAGE_GET = 0x1,
+	/* Store the field value into a file. */
+	MG_FORM_FIELD_STORAGE_STORE = 0x2,
+	/* Stop parsing this request. Skip the remaining fields. */
+	MG_FORM_FIELD_STORAGE_ABORT = 0x10
+};
+
+/* Process form data.
+ * Returns the number of fields handled, or < 0 in case of an error.
+ * Note: It is possible that several fields are already handled successfully
+ * (e.g., stored into files), before the request handling is stopped with an
+ * error. In this case a number < 0 is returned as well.
+ * In any case, it is the duty of the caller to remove files once they are
+ * no longer required. */
+CIVETWEB_API int mg_handle_form_request(struct mg_connection *conn,
+                                        struct mg_form_data_handler *fdh);
+
+
+/* Convenience function -- create detached thread.
+   Return: 0 on success, non-0 on error. */
+typedef void *(*mg_thread_func_t)(void *);
+CIVETWEB_API int mg_start_thread(mg_thread_func_t f, void *p);
+
+
+/* Return builtin mime type for the given file name.
+   For unrecognized extensions, "text/plain" is returned. */
+CIVETWEB_API const char *mg_get_builtin_mime_type(const char *file_name);
+
+
+/* Get text representation of HTTP status code. */
+CIVETWEB_API const char *
+mg_get_response_code_text(const struct mg_connection *conn, int response_code);
+
+
+/* Return CivetWeb version. */
+CIVETWEB_API const char *mg_version(void);
+
+
+/* URL-decode input buffer into destination buffer.
+   0-terminate the destination buffer.
+   form-url-encoded data differs from URI encoding in a way that it
+   uses '+' as character for space, see RFC 1866 section 8.2.1
+   http://ftp.ics.uci.edu/pub/ietf/html/rfc1866.txt
+   Return: length of the decoded data, or -1 if dst buffer is too small. */
+CIVETWEB_API int mg_url_decode(const char *src,
+                               int src_len,
+                               char *dst,
+                               int dst_len,
+                               int is_form_url_encoded);
+
+
+/* URL-encode input buffer into destination buffer.
+   returns the length of the resulting buffer or -1
+   is the buffer is too small. */
+CIVETWEB_API int mg_url_encode(const char *src, char *dst, size_t dst_len);
+
+
+/* MD5 hash given strings.
+   Buffer 'buf' must be 33 bytes long. Varargs is a NULL terminated list of
+   ASCIIz strings. When function returns, buf will contain human-readable
+   MD5 hash. Example:
+     char buf[33];
+     mg_md5(buf, "aa", "bb", NULL); */
+CIVETWEB_API char *mg_md5(char buf[33], ...);
+
+
+/* Print error message to the opened error log stream.
+   This utilizes the provided logging configuration.
+     conn: connection (not used for sending data, but to get perameters)
+     fmt: format string without the line return
+     ...: variable argument list
+   Example:
+     mg_cry(conn,"i like %s", "logging"); */
+CIVETWEB_API void mg_cry(const struct mg_connection *conn,
+                         PRINTF_FORMAT_STRING(const char *fmt),
+                         ...) PRINTF_ARGS(2, 3);
+
+
+/* utility methods to compare two buffers, case insensitive. */
+CIVETWEB_API int mg_strcasecmp(const char *s1, const char *s2);
+CIVETWEB_API int mg_strncasecmp(const char *s1, const char *s2, size_t len);
+
+ /* set connection's http status */
+CIVETWEB_API void mg_set_http_status(struct mg_connection *conn, int status);
+
+/* Connect to a websocket as a client
+   Parameters:
+     host: host to connect to, i.e. "echo.websocket.org" or "192.168.1.1" or
+   "localhost"
+     port: server port
+     use_ssl: make a secure connection to server
+     error_buffer, error_buffer_size: buffer for an error message
+     path: server path you are trying to connect to, i.e. if connection to
+   localhost/app, path should be "/app"
+     origin: value of the Origin HTTP header
+     data_func: callback that should be used when data is received from the
+   server
+     user_data: user supplied argument
+
+   Return:
+     On success, valid mg_connection object.
+     On error, NULL. Se error_buffer for details.
+*/
+CIVETWEB_API struct mg_connection *
+mg_connect_websocket_client(const char *host,
+                            int port,
+                            int use_ssl,
+                            char *error_buffer,
+                            size_t error_buffer_size,
+                            const char *path,
+                            const char *origin,
+                            mg_websocket_data_handler data_func,
+                            mg_websocket_close_handler close_func,
+                            void *user_data);
+
+
+/* Connect to a TCP server as a client (can be used to connect to a HTTP server)
+   Parameters:
+     host: host to connect to, i.e. "www.wikipedia.org" or "192.168.1.1" or
+   "localhost"
+     port: server port
+     use_ssl: make a secure connection to server
+     error_buffer, error_buffer_size: buffer for an error message
+
+   Return:
+     On success, valid mg_connection object.
+     On error, NULL. Se error_buffer for details.
+*/
+CIVETWEB_API struct mg_connection *mg_connect_client(const char *host,
+                                                     int port,
+                                                     int use_ssl,
+                                                     char *error_buffer,
+                                                     size_t error_buffer_size);
+
+
+struct mg_client_options {
+	const char *host;
+	int port;
+	const char *client_cert;
+	const char *server_cert;
+	/* TODO: add more data */
+};
+
+
+CIVETWEB_API struct mg_connection *
+mg_connect_client_secure(const struct mg_client_options *client_options,
+                         char *error_buffer,
+                         size_t error_buffer_size);
+
+
+enum { TIMEOUT_INFINITE = -1 };
+enum { MG_TIMEOUT_INFINITE = -1 };
+
+/* Wait for a response from the server
+   Parameters:
+     conn: connection
+     ebuf, ebuf_len: error message placeholder.
+     timeout: time to wait for a response in milliseconds (if < 0 then wait
+   forever)
+
+   Return:
+     On success, >= 0
+     On error/timeout, < 0
+*/
+CIVETWEB_API int mg_get_response(struct mg_connection *conn,
+                                 char *ebuf,
+                                 size_t ebuf_len,
+                                 int timeout);
+
+
+/* Check which features where set when the civetweb library has been compiled.
+   The function explicitly addresses compile time defines used when building
+   the library - it does not mean, the feature has been initialized using a
+   mg_init_library call.
+   mg_check_feature can be called anytime, even before mg_init_library has
+   been called.
+
+   Parameters:
+     feature: specifies which feature should be checked
+       The value is a bit mask. The individual bits are defined as:
+         1  serve files (NO_FILES not set)
+         2  support HTTPS (NO_SSL not set)
+         4  support CGI (NO_CGI not set)
+         8  support IPv6 (USE_IPV6 set)
+        16  support WebSocket (USE_WEBSOCKET set)
+        32  support Lua scripts and Lua server pages (USE_LUA is set)
+        64  support server side JavaScript (USE_DUKTAPE is set)
+       128  support caching (NO_CACHING not set)
+       256  support server statistics (USE_SERVER_STATS is set)
+       The result is undefined, if bits are set that do not represent a
+       defined feature (currently: feature >= 512).
+       The result is undefined, if no bit is set (feature == 0).
+
+   Return:
+     If feature is available, the corresponding bit is set
+     If feature is not available, the bit is 0
+*/
+CIVETWEB_API unsigned mg_check_feature(unsigned feature);
+
+
+/* Get information on the system. Useful for support requests.
+   Parameters:
+     buffer: Store system information as string here.
+     buflen: Length of buffer (including a byte required for a terminating 0).
+   Return:
+     Available size of system information, exluding a terminating 0.
+     The information is complete, if the return value is smaller than buflen.
+     The result is a JSON formatted string, the exact content may vary.
+   Note:
+     It is possible to determine the required buflen, by first calling this
+     function with buffer = NULL and buflen = NULL. The required buflen is
+     one byte more than the returned value.
+*/
+CIVETWEB_API int mg_get_system_info(char *buffer, int buflen);
+
+
+/* Get context information. Useful for server diagnosis.
+   Parameters:
+     ctx: Context handle
+     buffer: Store context information here.
+     buflen: Length of buffer (including a byte required for a terminating 0).
+   Return:
+     Available size of system information, exluding a terminating 0.
+     The information is complete, if the return value is smaller than buflen.
+     The result is a JSON formatted string, the exact content may vary.
+     Note:
+     It is possible to determine the required buflen, by first calling this
+     function with buffer = NULL and buflen = NULL. The required buflen is
+     one byte more than the returned value. However, since the available
+     context information changes, you should allocate a few bytes more.
+*/
+CIVETWEB_API int
+mg_get_context_info(const struct mg_context *ctx, char *buffer, int buflen);
+
+
+#ifdef MG_EXPERIMENTAL_INTERFACES
+/* Get connection information. Useful for server diagnosis.
+   Parameters:
+     ctx: Context handle
+     idx: Connection index
+     buffer: Store context information here.
+     buflen: Length of buffer (including a byte required for a terminating 0).
+   Return:
+     Available size of system information, exluding a terminating 0.
+     The information is complete, if the return value is smaller than buflen.
+     The result is a JSON formatted string, the exact content may vary.
+   Note:
+     It is possible to determine the required buflen, by first calling this
+     function with buffer = NULL and buflen = NULL. The required buflen is
+     one byte more than the returned value. However, since the available
+     context information changes, you should allocate a few bytes more.
+*/
+CIVETWEB_API int mg_get_connection_info(const struct mg_context *ctx,
+                                        int idx,
+                                        char *buffer,
+                                        int buflen);
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* CIVETWEB_HEADER_INCLUDED */