mongoose.h

 * (an event loop). It returns number of user events generated (except POLLs).
 * `milli` is the maximum number of milliseconds to sleep.
 * `mg_mgr_poll()` checks all connections for IO readiness. If at least one
 * of the connections is IO-ready, `mg_mgr_poll()` triggers the respective
 * event handlers and returns.
 */
int mg_mgr_poll(struct mg_mgr *mgr, int milli);

#if MG_ENABLE_BROADCAST
/*
 * Passes a message of a given length to all connections.
 *
 * Must be called from a thread that does NOT call `mg_mgr_poll()`.
 * Note that `mg_broadcast()` is the only function
 * that can be, and must be, called from a different (non-IO) thread.
 *
 * `func` callback function will be called by the IO thread for each
 * connection. When called, the event will be `MG_EV_POLL`, and a message will
 * be passed as the `ev_data` pointer. Maximum message size is capped
 * by `MG_CTL_MSG_MESSAGE_SIZE` which is set to 8192 bytes.
 */
void mg_broadcast(struct mg_mgr *mgr, mg_event_handler_t cb, void *data,
                  size_t len);
#endif

/*
 * Iterates over all active connections.
 *
 * Returns the next connection from the list
 * of active connections or `NULL` if there are no more connections. Below
 * is the iteration idiom:
 *
 * ```c
 * for (c = mg_next(srv, NULL); c != NULL; c = mg_next(srv, c)) {
 *   // Do something with connection `c`
 * }
 * ```
 */
struct mg_connection *mg_next(struct mg_mgr *mgr, struct mg_connection *c);

/*
 * Optional parameters to `mg_add_sock_opt()`.
 *
 * `flags` is an initial `struct mg_connection::flags` bitmask to set,
 * see `MG_F_*` flags definitions.
 */
struct mg_add_sock_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Initial connection flags */
  const char **error_string; /* Placeholder for the error string */
  struct mg_iface *iface;    /* Interface instance */
};

/*
 * Creates a connection, associates it with the given socket and event handler
 * and adds it to the manager.
 *
 * For more options see the `mg_add_sock_opt` variant.
 */
struct mg_connection *mg_add_sock(struct mg_mgr *mgr, sock_t sock,
                                  MG_CB(mg_event_handler_t handler,
                                        void *user_data));

/*
 * Creates a connection, associates it with the given socket and event handler
 * and adds to the manager.
 *
 * See the `mg_add_sock_opts` structure for a description of the options.
 */
struct mg_connection *mg_add_sock_opt(struct mg_mgr *mgr, sock_t sock,
                                      MG_CB(mg_event_handler_t handler,
                                            void *user_data),
                                      struct mg_add_sock_opts opts);

/*
 * Optional parameters to `mg_bind_opt()`.
 *
 * `flags` is an initial `struct mg_connection::flags` bitmask to set,
 * see `MG_F_*` flags definitions.
 */
struct mg_bind_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Extra connection flags */
  const char **error_string; /* Placeholder for the error string */
  struct mg_iface *iface;    /* Interface instance */
#if MG_ENABLE_SSL
  /*
   * SSL settings.
   *
   * Server certificate to present to clients or client certificate to
   * present to tunnel dispatcher (for tunneled connections).
   */
  const char *ssl_cert;
  /* Private key corresponding to the certificate. If ssl_cert is set but
   * ssl_key is not, ssl_cert is used. */
  const char *ssl_key;
  /* CA bundle used to verify client certificates or tunnel dispatchers. */
  const char *ssl_ca_cert;
  /* Colon-delimited list of acceptable cipher suites.
   * Names depend on the library used, for example:
   *
   * ECDH-ECDSA-AES128-GCM-SHA256:DHE-RSA-AES128-SHA256 (OpenSSL)
   * TLS-ECDH-ECDSA-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256
   *   (mbedTLS)
   *
   * For OpenSSL the list can be obtained by running "openssl ciphers".
   * For mbedTLS, names can be found in library/ssl_ciphersuites.c
   * If NULL, a reasonable default is used.
   */
  const char *ssl_cipher_suites;
#endif
};

/*
 * Creates a listening connection.
 *
 * See `mg_bind_opt` for full documentation.
 */
struct mg_connection *mg_bind(struct mg_mgr *mgr, const char *address,
                              MG_CB(mg_event_handler_t handler,
                                    void *user_data));
/*
 * Creates a listening connection.
 *
 * The `address` parameter specifies which address to bind to. It's format is
 * the same as for the `mg_connect()` call, where `HOST` part is optional.
 * `address` can be just a port number, e.g. `:8000`. To bind to a specific
 * interface, an IP address can be specified, e.g. `1.2.3.4:8000`. By default,
 * a TCP connection is created. To create UDP connection, prepend `udp://`
 * prefix, e.g. `udp://:8000`. To summarize, `address` parameter has following
 * format: `[PROTO://][IP_ADDRESS]:PORT`, where `PROTO` could be `tcp` or
 * `udp`.
 *
 * See the `mg_bind_opts` structure for a description of the optional
 * parameters.
 *
 * Returns a new listening connection or `NULL` on error.
 * NOTE: The connection remains owned by the manager, do not free().
 */
struct mg_connection *mg_bind_opt(struct mg_mgr *mgr, const char *address,
                                  MG_CB(mg_event_handler_t handler,
                                        void *user_data),
                                  struct mg_bind_opts opts);

/* Optional parameters to `mg_connect_opt()` */
struct mg_connect_opts {
  void *user_data;           /* Initial value for connection's user_data */
  unsigned int flags;        /* Extra connection flags */
  const char **error_string; /* Placeholder for the error string */
  struct mg_iface *iface;    /* Interface instance */
  const char *nameserver;    /* DNS server to use, NULL for default */
#if MG_ENABLE_SSL
  /*
   * SSL settings.
   * Client certificate to present to the server.
   */
  const char *ssl_cert;
  /*
   * Private key corresponding to the certificate.
   * If ssl_cert is set but ssl_key is not, ssl_cert is used.
   */
  const char *ssl_key;
  /*
   * Verify server certificate using this CA bundle. If set to "*", then SSL
   * is enabled but no cert verification is performed.
   */
  const char *ssl_ca_cert;
  /* Colon-delimited list of acceptable cipher suites.
   * Names depend on the library used, for example:
   *
   * ECDH-ECDSA-AES128-GCM-SHA256:DHE-RSA-AES128-SHA256 (OpenSSL)
   * TLS-ECDH-ECDSA-WITH-AES-128-GCM-SHA256:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256
   *   (mbedTLS)
   *
   * For OpenSSL the list can be obtained by running "openssl ciphers".
   * For mbedTLS, names can be found in library/ssl_ciphersuites.c
   * If NULL, a reasonable default is used.
   */
  const char *ssl_cipher_suites;
  /*
   * Server name verification. If ssl_ca_cert is set and the certificate has
   * passed verification, its subject will be verified against this string.
   * By default (if ssl_server_name is NULL) hostname part of the address will
   * be used. Wildcard matching is supported. A special value of "*" disables
   * name verification.
   */
  const char *ssl_server_name;
  /*
   * PSK identity and key. Identity is a NUL-terminated string and key is a hex
   * string. Key must be either 16 or 32 bytes (32 or 64 hex digits) for AES-128
   * or AES-256 respectively.
   * Note: Default list of cipher suites does not include PSK suites, if you
   * want to use PSK you will need to set ssl_cipher_suites as well.
   */
  const char *ssl_psk_identity;
  const char *ssl_psk_key;
#endif
};

/*
 * Connects to a remote host.
 *
 * See `mg_connect_opt()` for full documentation.
 */
struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *address,
                                 MG_CB(mg_event_handler_t handler,
                                       void *user_data));

/*
 * Connects to a remote host.
 *
 * The `address` format is `[PROTO://]HOST:PORT`. `PROTO` could be `tcp` or
 * `udp`. `HOST` could be an IP address,
 * IPv6 address (if Mongoose is compiled with `-DMG_ENABLE_IPV6`) or a host
 * name. If `HOST` is a name, Mongoose will resolve it asynchronously. Examples
 * of valid addresses: `google.com:80`, `udp://1.2.3.4:53`, `10.0.0.1:443`,
 * `[::1]:80`
 *
 * See the `mg_connect_opts` structure for a description of the optional
 * parameters.
 *
 * Returns a new outbound connection or `NULL` on error.
 *
 * NOTE: The connection remains owned by the manager, do not free().
 *
 * NOTE: To enable IPv6 addresses `-DMG_ENABLE_IPV6` should be specified
 * in the compilation flags.
 *
 * NOTE: The new connection will receive `MG_EV_CONNECT` as its first event
 * which will report the connect success status.
 * If the asynchronous resolution fails or the `connect()` syscall fails for
 * whatever reason (e.g. with `ECONNREFUSED` or `ENETUNREACH`), then
 * `MG_EV_CONNECT` event will report failure. Code example below:
 *
 * ```c
 * static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
 *   int connect_status;
 *
 *   switch (ev) {
 *     case MG_EV_CONNECT:
 *       connect_status = * (int *) ev_data;
 *       if (connect_status == 0) {
 *         // Success
 *       } else  {
 *         // Error
 *         printf("connect() error: %s\n", strerror(connect_status));
 *       }
 *       break;
 *     ...
 *   }
 * }
 *
 *   ...
 *   mg_connect(mgr, "my_site.com:80", ev_handler);
 * ```
 */
struct mg_connection *mg_connect_opt(struct mg_mgr *mgr, const char *address,
                                     MG_CB(mg_event_handler_t handler,
                                           void *user_data),
                                     struct mg_connect_opts opts);

#if MG_ENABLE_SSL && MG_NET_IF != MG_NET_IF_SIMPLELINK
/*
 * Note: This function is deprecated. Please, use SSL options in
 * mg_connect_opt.
 *
 * Enables SSL for a given connection.
 * `cert` is a server certificate file name for a listening connection
 * or a client certificate file name for an outgoing connection.
 * The certificate files must be in PEM format. The server certificate file
 * must contain a certificate, concatenated with a private key, optionally
 * concatenated with DH parameters.
 * `ca_cert` is a CA certificate or NULL if peer verification is not
 * required.
 * Return: NULL on success or error message on error.
 */
const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
                       const char *ca_cert);
#endif

/*
 * Sends data to the connection.
 *
 * Note that sending functions do not actually push data to the socket.
 * They just append data to the output buffer. MG_EV_SEND will be delivered when
 * the data has actually been pushed out.
 */
void mg_send(struct mg_connection *, const void *buf, int len);

/* Enables format string warnings for mg_printf */
#if defined(__GNUC__)
__attribute__((format(printf, 2, 3)))
#endif
/* don't separate from mg_printf declaration */

/*
 * Sends `printf`-style formatted data to the connection.
 *
 * See `mg_send` for more details on send semantics.
 */
int mg_printf(struct mg_connection *, const char *fmt, ...);

/* Same as `mg_printf()`, but takes `va_list ap` as an argument. */
int mg_vprintf(struct mg_connection *, const char *fmt, va_list ap);

/*
 * Creates a socket pair.
 * `sock_type` can be either `SOCK_STREAM` or `SOCK_DGRAM`.
 * Returns 0 on failure and 1 on success.
 */
int mg_socketpair(sock_t[2], int sock_type);

#if MG_ENABLE_SYNC_RESOLVER
/*
 * Convert domain name into IP address.
 *
 * This is a utility function. If compilation flags have
 * `-DMG_ENABLE_GETADDRINFO`, then `getaddrinfo()` call is used for name
 * resolution. Otherwise, `gethostbyname()` is used.
 *
 * CAUTION: this function can block.
 * Return 1 on success, 0 on failure.
 */
int mg_resolve(const char *domain_name, char *ip_addr_buf, size_t buf_len);
#endif

/*
 * Verify given IP address against the ACL.
 *
 * `remote_ip` - an IPv4 address to check, in host byte order
 * `acl` - a comma separated list of IP subnets: `x.x.x.x/x` or `x.x.x.x`.
 * Each subnet is
 * prepended by either a - or a + sign. A plus sign means allow, where a
 * minus sign means deny. If a subnet mask is omitted, such as `-1.2.3.4`,
 * it means that only that single IP address is denied.
 * Subnet masks may vary from 0 to 32, inclusive. The default setting
 * is to allow all access. On each request the full list is traversed,
 * and the last match wins. Example:
 *
 * `-0.0.0.0/0,+192.168/16` - deny all accesses, only allow 192.168/16 subnet
 *
 * To learn more about subnet masks, see this
 * link:https://en.wikipedia.org/wiki/Subnetwork[Wikipedia page on Subnetwork].
 *
 * Returns -1 if ACL is malformed, 0 if address is disallowed, 1 if allowed.
 */
int mg_check_ip_acl(const char *acl, uint32_t remote_ip);

/*
 * Schedules an MG_EV_TIMER event to be delivered at `timestamp` time.
 * `timestamp` is UNIX time (the number of seconds since Epoch). It is
 * `double` instead of `time_t` to allow for sub-second precision.
 * Returns the old timer value.
 *
 * Example: set the connect timeout to 1.5 seconds:
 *
 * ```
 *  c = mg_connect(&mgr, "cesanta.com", ev_handler);
 *  mg_set_timer(c, mg_time() + 1.5);
 *  ...
 *
 *  void ev_handler(struct mg_connection *c, int ev, void *ev_data) {
 *  switch (ev) {
 *    case MG_EV_CONNECT:
 *      mg_set_timer(c, 0);  // Clear connect timer
 *      break;
 *    case MG_EV_TIMER:
 *      log("Connect timeout");
 *      c->flags |= MG_F_CLOSE_IMMEDIATELY;
 *      break;
 * ```
 */
double mg_set_timer(struct mg_connection *c, double timestamp);

/*
 * A sub-second precision version of time().
 */
double mg_time(void);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_MONGOOSE_SRC_NET_H_ */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_uri.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/*
 * === URI
 */

#ifndef CS_MONGOOSE_SRC_URI_H_
#define CS_MONGOOSE_SRC_URI_H_

/* Amalgamated: #include "mg_net.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/*
 * Parses an URI and fills string chunks with locations of the respective
 * uri components within the input uri string. NULL pointers will be
 * ignored.
 *
 * General syntax:
 *
 *     [scheme://[user_info@]]host[:port][/path][?query][#fragment]
 *
 * Example:
 *
 *     foo.com:80
 *     tcp://foo.com:1234
 *     http://foo.com:80/bar?baz=1
 *     https://user:pw@foo.com:443/blah
 *
 * `path` will include the leading slash. `query` won't include the leading `?`.
 * `host` can contain embedded colons if surrounded by square brackets in order
 * to support IPv6 literal addresses.
 *
 *
 * Returns 0 on success, -1 on error.
 */
int mg_parse_uri(const struct mg_str uri, struct mg_str *scheme,
                 struct mg_str *user_info, struct mg_str *host,
                 unsigned int *port, struct mg_str *path, struct mg_str *query,
                 struct mg_str *fragment);

/*
 * Assemble URI from parts. Any of the inputs can be NULL or zero-length mg_str.
 *
 * If normalize_path is true, path is normalized by resolving relative refs.
 *
 * Result is a heap-allocated string (uri->p must be free()d after use).
 *
 * Returns 0 on success, -1 on error.
 */
int mg_assemble_uri(const struct mg_str *scheme, const struct mg_str *user_info,
                    const struct mg_str *host, unsigned int port,
                    const struct mg_str *path, const struct mg_str *query,
                    const struct mg_str *fragment, int normalize_path,
                    struct mg_str *uri);

int mg_normalize_uri_path(const struct mg_str *in, struct mg_str *out);

#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* CS_MONGOOSE_SRC_URI_H_ */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_util.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/*
 * === Utility API
 */

#ifndef CS_MONGOOSE_SRC_UTIL_H_
#define CS_MONGOOSE_SRC_UTIL_H_

#include <stdio.h>

/* Amalgamated: #include "mg_common.h" */
/* Amalgamated: #include "mg_net_if.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MG_MAX_PATH
#ifdef PATH_MAX
#define MG_MAX_PATH PATH_MAX
#else
#define MG_MAX_PATH 256
#endif
#endif

/*
 * Fetches substring from input string `s`, `end` into `v`.
 * Skips initial delimiter characters. Records first non-delimiter character
 * at the beginning of substring `v`. Then scans the rest of the string
 * until a delimiter character or end-of-string is found.
 * `delimiters` is a 0-terminated string containing delimiter characters.
 * Either one of `delimiters` or `end_string` terminates the search.
 * Returns an `s` pointer, advanced forward where parsing has stopped.
 */
const char *mg_skip(const char *s, const char *end_string,
                    const char *delimiters, struct mg_str *v);

/*
 * Decodes base64-encoded string `s`, `len` into the destination `dst`.
 * The destination has to have enough space to hold the decoded buffer.
 * Decoding stops either when all strings have been decoded or invalid an
 * character appeared.
 * Destination is '\0'-terminated.
 * Returns the number of decoded characters. On success, that should be equal
 * to `len`. On error (invalid character) the return value is smaller then
 * `len`.
 */
int mg_base64_decode(const unsigned char *s, int len, char *dst);

/*
 * Base64-encode chunk of memory `src`, `src_len` into the destination `dst`.
 * Destination has to have enough space to hold encoded buffer.
 * Destination is '\0'-terminated.
 */
void mg_base64_encode(const unsigned char *src, int src_len, char *dst);

#if MG_ENABLE_FILESYSTEM
/*
 * Performs a 64-bit `stat()` call against a given file.
 *
 * `path` should be UTF8 encoded.
 *
 * Return value is the same as for `stat()` syscall.
 */
int mg_stat(const char *path, cs_stat_t *st);

/*
 * Opens the given file and returns a file stream.
 *
 * `path` and `mode` should be UTF8 encoded.
 *
 * Return value is the same as for the `fopen()` call.
 */
FILE *mg_fopen(const char *path, const char *mode);

/*
 * Opens the given file and returns a file stream.
 *
 * `path` should be UTF8 encoded.
 *
 * Return value is the same as for the `open()` syscall.
 */
int mg_open(const char *path, int flag, int mode);

/*
 * Reads data from the given file stream.
 *
 * Return value is a number of bytes readen.
 */
size_t mg_fread(void *ptr, size_t size, size_t count, FILE *f);

/*
 * Writes data to the given file stream.
 *
 * Return value is a number of bytes wtitten.
 */
size_t mg_fwrite(const void *ptr, size_t size, size_t count, FILE *f);

#endif /* MG_ENABLE_FILESYSTEM */

#if MG_ENABLE_THREADS
/*
 * Starts a new detached thread.
 * Arguments and semantics are the same as pthead's `pthread_create()`.
 * `thread_func` is a thread function, `thread_func_param` is a parameter
 * that is passed to the thread function.
 */
void *mg_start_thread(void *(*thread_func)(void *), void *thread_func_param);
#endif

void mg_set_close_on_exec(sock_t);

#define MG_SOCK_STRINGIFY_IP 1
#define MG_SOCK_STRINGIFY_PORT 2
#define MG_SOCK_STRINGIFY_REMOTE 4
/*
 * Converts a connection's local or remote address into string.
 *
 * The `flags` parameter is a bit mask that controls the behaviour,
 * see `MG_SOCK_STRINGIFY_*` definitions.
 *
 * - MG_SOCK_STRINGIFY_IP - print IP address
 * - MG_SOCK_STRINGIFY_PORT - print port number
 * - MG_SOCK_STRINGIFY_REMOTE - print remote peer's IP/port, not local address
 *
 * If both port number and IP address are printed, they are separated by `:`.
 * If compiled with `-DMG_ENABLE_IPV6`, IPv6 addresses are supported.
 * Return length of the stringified address.
 */
int mg_conn_addr_to_str(struct mg_connection *c, char *buf, size_t len,
                        int flags);
#if MG_NET_IF == MG_NET_IF_SOCKET
/* Legacy interface. */
void mg_sock_to_str(sock_t sock, char *buf, size_t len, int flags);
#endif

/*
 * Convert the socket's address into string.
 *
 * `flags` is MG_SOCK_STRINGIFY_IP and/or MG_SOCK_STRINGIFY_PORT.
 */
int mg_sock_addr_to_str(const union socket_address *sa, char *buf, size_t len,
                        int flags);

#if MG_ENABLE_HEXDUMP
/*
 * Generates a human-readable hexdump of memory chunk.
 *
 * Takes a memory buffer `buf` of length `len` and creates a hex dump of that
 * buffer in `dst`. The generated output is a-la hexdump(1).
 * Returns the length of generated string, excluding terminating `\0`. If
 * returned length is bigger than `dst_len`, the overflow bytes are discarded.
 */
int mg_hexdump(const void *buf, int len, char *dst, int dst_len);

/* Same as mg_hexdump, but with output going to file instead of a buffer. */
void mg_hexdumpf(FILE *fp, const void *buf, int len);

/*
 * Generates human-readable hexdump of the data sent or received by the
 * connection. `path` is a file name where hexdump should be written.
 * `num_bytes` is a number of bytes sent/received. `ev` is one of the `MG_*`
 * events sent to an event handler. This function is supposed to be called from
 * the event handler.
 */
void mg_hexdump_connection(struct mg_connection *nc, const char *path,
                           const void *buf, int num_bytes, int ev);
#endif

/*
 * Returns true if target platform is big endian.
 */
int mg_is_big_endian(void);

/*
 * Use with cs_base64_init/update/finish in order to write out base64 in chunks.
 */
void mg_mbuf_append_base64_putc(char ch, void *user_data);

/*
 * Encode `len` bytes starting at `data` as base64 and append them to an mbuf.
 */
void mg_mbuf_append_base64(struct mbuf *mbuf, const void *data, size_t len);

/*
 * Generate a Basic Auth header and appends it to buf.
 * If pass is NULL, then user is expected to contain the credentials pair
 * already encoded as `user:pass`.
 */
void mg_basic_auth_header(const struct mg_str user, const struct mg_str pass,
                          struct mbuf *buf);

/*
 * URL-escape the specified string.
 * All characters acept letters, numbers and characters listed in
 * `safe` are escaped. If `hex_upper`is true, `A-F` are used for hex digits.
 * Input need not be NUL-terminated, but the returned string is.
 * Returned string is heap-allocated and must be free()'d.
 */
#define MG_URL_ENCODE_F_SPACE_AS_PLUS (1 << 0)
#define MG_URL_ENCODE_F_UPPERCASE_HEX (1 << 1)
struct mg_str mg_url_encode_opt(const struct mg_str src,
                                const struct mg_str safe, unsigned int flags);

/* Same as `mg_url_encode_opt(src, "._-$,;~()/", 0)`. */
struct mg_str mg_url_encode(const struct mg_str src);

#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* CS_MONGOOSE_SRC_UTIL_H_ */
#ifdef MG_MODULE_LINES
#line 1 "mongoose/src/mg_http.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/*
 * === Common API reference
 */

#ifndef CS_MONGOOSE_SRC_HTTP_H_
#define CS_MONGOOSE_SRC_HTTP_H_

#if MG_ENABLE_HTTP

/* Amalgamated: #include "mg_net.h" */
/* Amalgamated: #include "common/mg_str.h" */

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#ifndef MG_MAX_HTTP_HEADERS
#define MG_MAX_HTTP_HEADERS 20
#endif

#ifndef MG_MAX_HTTP_REQUEST_SIZE
#define MG_MAX_HTTP_REQUEST_SIZE 1024
#endif

#ifndef MG_MAX_HTTP_SEND_MBUF
#define MG_MAX_HTTP_SEND_MBUF 1024
#endif

#ifndef MG_CGI_ENVIRONMENT_SIZE
#define MG_CGI_ENVIRONMENT_SIZE 8192
#endif

/* HTTP message */
struct http_message {
  struct mg_str message; /* Whole message: request line + headers + body */
  struct mg_str body;    /* Message body. 0-length for requests with no body */

  /* HTTP Request line (or HTTP response line) */
  struct mg_str method; /* "GET" */
  struct mg_str uri;    /* "/my_file.html" */
  struct mg_str proto;  /* "HTTP/1.1" -- for both request and response */

  /* For responses, code and response status message are set */
  int resp_code;
  struct mg_str resp_status_msg;

  /*
   * Query-string part of the URI. For example, for HTTP request
   *    GET /foo/bar?param1=val1&param2=val2
   *    |    uri    |     query_string     |
   *
   * Note that question mark character doesn't belong neither to the uri,
   * nor to the query_string
   */
  struct mg_str query_string;

  /* Headers */
  struct mg_str header_names[MG_MAX_HTTP_HEADERS];
  struct mg_str header_values[MG_MAX_HTTP_HEADERS];
};

#if MG_ENABLE_HTTP_WEBSOCKET
/* WebSocket message */
struct websocket_message {
  unsigned char *data;
  size_t size;
  unsigned char flags;
};
#endif

/* HTTP multipart part */
struct mg_http_multipart_part {
  const char *file_name;
  const char *var_name;
  struct mg_str data;
  int status; /* <0 on error */
  void *user_data;
};

/* SSI call context */
struct mg_ssi_call_ctx {
  struct http_message *req; /* The request being processed. */
  struct mg_str file;       /* Filesystem path of the file being processed. */
  struct mg_str arg; /* The argument passed to the tag: <!-- call arg -->. */
};

/* HTTP and websocket events. void *ev_data is described in a comment. */
#define MG_EV_HTTP_REQUEST 100 /* struct http_message * */
#define MG_EV_HTTP_REPLY 101   /* struct http_message * */
#define MG_EV_HTTP_CHUNK 102   /* struct http_message * */
#define MG_EV_SSI_CALL 105     /* char * */
#define MG_EV_SSI_CALL_CTX 106 /* struct mg_ssi_call_ctx * */

#if MG_ENABLE_HTTP_WEBSOCKET
#define MG_EV_WEBSOCKET_HANDSHAKE_REQUEST 111 /* struct http_message * */
#define MG_EV_WEBSOCKET_HANDSHAKE_DONE 112    /* NULL */
#define MG_EV_WEBSOCKET_FRAME 113             /* struct websocket_message * */
#define MG_EV_WEBSOCKET_CONTROL_FRAME 114     /* struct websocket_message * */
#endif

#if MG_ENABLE_HTTP_STREAMING_MULTIPART
#define MG_EV_HTTP_MULTIPART_REQUEST 121 /* struct http_message */
#define MG_EV_HTTP_PART_BEGIN 122        /* struct mg_http_multipart_part */
#define MG_EV_HTTP_PART_DATA 123         /* struct mg_http_multipart_part */
#define MG_EV_HTTP_PART_END 124          /* struct mg_http_multipart_part */
/* struct mg_http_multipart_part */
#define MG_EV_HTTP_MULTIPART_REQUEST_END 125
#endif

/*
 * Attaches a built-in HTTP event handler to the given connection.
 * The user-defined event handler will receive following extra events:
 *
 * - MG_EV_HTTP_REQUEST: HTTP request has arrived. Parsed HTTP request
 *  is passed as
 *   `struct http_message` through the handler's `void *ev_data` pointer.
 * - MG_EV_HTTP_REPLY: The HTTP reply has arrived. The parsed HTTP reply is
 *   passed as `struct http_message` through the handler's `void *ev_data`
 *   pointer.
 * - MG_EV_HTTP_CHUNK: The HTTP chunked-encoding chunk has arrived.
 *   The parsed HTTP reply is passed as `struct http_message` through the
 *   handler's `void *ev_data` pointer. `http_message::body` would contain
 *   incomplete, reassembled HTTP body.
 *   It will grow with every new chunk that arrives, and it can
 *   potentially consume a lot of memory. An event handler may process
 *   the body as chunks are coming, and signal Mongoose to delete processed
 *   body by setting `MG_F_DELETE_CHUNK` in `mg_connection::flags`. When
 *   the last zero chunk is received,
 *   Mongoose sends `MG_EV_HTTP_REPLY` event with
 *   full reassembled body (if handler did not signal to delete chunks) or
 *   with empty body (if handler did signal to delete chunks).
 * - MG_EV_WEBSOCKET_HANDSHAKE_REQUEST: server has received the WebSocket
 *   handshake request. `ev_data` contains parsed HTTP request.
 * - MG_EV_WEBSOCKET_HANDSHAKE_DONE: server has completed the WebSocket
 *   handshake. `ev_data` is `NULL`.
 * - MG_EV_WEBSOCKET_FRAME: new WebSocket frame has arrived. `ev_data` is
 *   `struct websocket_message *`
 *
 * When compiled with MG_ENABLE_HTTP_STREAMING_MULTIPART, Mongoose parses
 * multipart requests and splits them into separate events:
 * - MG_EV_HTTP_MULTIPART_REQUEST: Start of the request.
 *   This event is sent before body is parsed. After this, the user
 *   should expect a sequence of PART_BEGIN/DATA/END requests.
 *   This is also the last time when headers and other request fields are
 *   accessible.
 * - MG_EV_HTTP_PART_BEGIN: Start of a part of a multipart message.
 *   Argument: mg_http_multipart_part with var_name and file_name set
 *   (if present). No data is passed in this message.
 * - MG_EV_HTTP_PART_DATA: new portion of data from the multipart message.
 *   Argument: mg_http_multipart_part. var_name and file_name are preserved,
 *   data is available in mg_http_multipart_part.data.
 * - MG_EV_HTTP_PART_END: End of the current part. var_name, file_name are
 *   the same, no data in the message. If status is 0, then the part is
 *   properly terminated with a boundary, status < 0 means that connection
 *   was terminated.
 * - MG_EV_HTTP_MULTIPART_REQUEST_END: End of the multipart request.
 *   Argument: mg_http_multipart_part, var_name and file_name are NULL,
 *   status = 0 means request was properly closed, < 0 means connection
 *   was terminated (note: in this case both PART_END and REQUEST_END are
 *   delivered).
 */
void mg_set_protocol_http_websocket(struct mg_connection *nc);

#if MG_ENABLE_HTTP_WEBSOCKET
/*
 * Send websocket handshake to the server.
 *
 * `nc` must be a valid connection, connected to a server. `uri` is an URI
 * to fetch, extra_headers` is extra HTTP headers to send or `NULL`.
 *
 * This function is intended to be used by websocket client.
 *
 * Note that the Host header is mandatory in HTTP/1.1 and must be
 * included in `extra_headers`. `mg_send_websocket_handshake2` offers
 * a better API for that.
 *
 * Deprecated in favour of `mg_send_websocket_handshake2`
 */
void mg_send_websocket_handshake(struct mg_connection *nc, const char *uri,
                                 const char *extra_headers);

/*
 * Send websocket handshake to the server.
 *
 * `nc` must be a valid connection, connected to a server. `uri` is an URI
 * to fetch, `host` goes into the `Host` header, `protocol` goes into the
 * `Sec-WebSocket-Proto` header (NULL to omit), extra_headers` is extra HTTP
 * headers to send or `NULL`.
 *
 * This function is intended to be used by websocket client.
 */
void mg_send_websocket_handshake2(struct mg_connection *nc, const char *path,
                                  const char *host, const char *protocol,
                                  const char *extra_headers);

/* Like mg_send_websocket_handshake2 but also passes basic auth header */
void mg_send_websocket_handshake3(struct mg_connection *nc, const char *path,
                                  const char *host, const char *protocol,
                                  const char *extra_headers, const char *user,
                                  const char *pass);

/* Same as mg_send_websocket_handshake3 but with strings not necessarily
 * NUL-temrinated */
void mg_send_websocket_handshake3v(struct mg_connection *nc,
                                   const struct mg_str path,
                                   const struct mg_str host,
                                   const struct mg_str protocol,
                                   const struct mg_str extra_headers,
                                   const struct mg_str user,
                                   const struct mg_str pass);

/*
 * Helper function that creates an outbound WebSocket connection.
 *
 * `url` is a URL to connect to. It must be properly URL-encoded, e.g. have
 * no spaces, etc. By default, `mg_connect_ws()` sends Connection and
 * Host headers. `extra_headers` is an extra HTTP header to send, e.g.
 * `"User-Agent: my-app\r\n"`.
 * If `protocol` is not NULL, then a `Sec-WebSocket-Protocol` header is sent.
 *
 * Examples:
 *
 * ```c
 *   nc1 = mg_connect_ws(mgr, ev_handler_1, "ws://echo.websocket.org", NULL,
 *                       NULL);
 *   nc2 = mg_connect_ws(mgr, ev_handler_1, "wss://echo.websocket.org", NULL,
 *                       NULL);
 *   nc3 = mg_connect_ws(mgr, ev_handler_1, "ws://api.cesanta.com",
 *                       "clubby.cesanta.com", NULL);
 * ```
 */
struct mg_connection *mg_connect_ws(struct mg_mgr *mgr,
                                    MG_CB(mg_event_handler_t event_handler,
                                          void *user_data),
                                    const char *url, const char *protocol,
                                    const char *extra_headers);

/*
 * Helper function that creates an outbound WebSocket connection
 *
 * Mostly identical to `mg_connect_ws`, but allows to provide extra parameters
 * (for example, SSL parameters)
 */
struct mg_connection *mg_connect_ws_opt(
    struct mg_mgr *mgr, MG_CB(mg_event_handler_t ev_handler, void *user_data),
    struct mg_connect_opts opts, const char *url, const char *protocol,
    const char *extra_headers);

/*
 * Send WebSocket frame to the remote end.
 *
 * `op_and_flags` specifies the frame's type. It's one of:
 *
 * - WEBSOCKET_OP_CONTINUE
 * - WEBSOCKET_OP_TEXT
 * - WEBSOCKET_OP_BINARY
 * - WEBSOCKET_OP_CLOSE
 * - WEBSOCKET_OP_PING
 * - WEBSOCKET_OP_PONG
 *
 * Orred with one of the flags:
 *
 * - WEBSOCKET_DONT_FIN: Don't set the FIN flag on the frame to be sent.
 *
 * `data` and `data_len` contain frame data.
 */
void mg_send_websocket_frame(struct mg_connection *nc, int op_and_flags,
                             const void *data, size_t data_len);

/*
 * Like `mg_send_websocket_frame()`, but composes a single frame from multiple
 * buffers.
 */
void mg_send_websocket_framev(struct mg_connection *nc, int op_and_flags,
                              const struct mg_str *strings, int num_strings);

/*
 * Sends WebSocket frame to the remote end.
 *
 * Like `mg_send_websocket_frame()`, but allows to create formatted messages
 * with `printf()`-like semantics.
 */
void mg_printf_websocket_frame(struct mg_connection *nc, int op_and_flags,
                               const char *fmt, ...);

/* Websocket opcodes, from http://tools.ietf.org/html/rfc6455 */
#define WEBSOCKET_OP_CONTINUE 0
#define WEBSOCKET_OP_TEXT 1
#define WEBSOCKET_OP_BINARY 2
#define WEBSOCKET_OP_CLOSE 8
#define WEBSOCKET_OP_PING 9
#define WEBSOCKET_OP_PONG 10

/*
 * If set causes the FIN flag to not be set on outbound
 * frames. This enables sending multiple fragments of a single
 * logical message.
 *
 * The WebSocket protocol mandates that if the FIN flag of a data
 * frame is not set, the next frame must be a WEBSOCKET_OP_CONTINUE.
 * The last frame must have the FIN bit set.
 *
 * Note that mongoose will automatically defragment incoming messages,
 * so this flag is used only on outbound messages.
 */
#define WEBSOCKET_DONT_FIN 0x100

#endif /* MG_ENABLE_HTTP_WEBSOCKET */

/*
 * Decodes a URL-encoded string.
 *
 * Source string is specified by (`src`, `src_len`), and destination is
 * (`dst`, `dst_len`). If `is_form_url_encoded` is non-zero, then
 * `+` character is decoded as a blank space character. This function
 * guarantees to NUL-terminate the destination. If destination is too small,
 * then the source string is partially decoded and `-1` is returned.
 *Otherwise,
 * a length of the decoded string is returned, not counting final NUL.
 */