/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
 *
 * 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.
 */

/*! \defgroup cgi cgi handling
 *
 * ##CGI handling
 *
 * These functions allow low-level control over stdin/out/err of the cgi.
 *
 * However for most cases, binding the cgi to http in and out, the default
 * lws implementation already does the right thing.
 */

enum lws_enum_stdinouterr {
	LWS_STDIN = 0,
	LWS_STDOUT = 1,
	LWS_STDERR = 2,
};

enum lws_cgi_hdr_state {
	LCHS_HEADER,
	LCHS_CR1,
	LCHS_LF1,
	LCHS_CR2,
	LCHS_LF2,
	LHCS_RESPONSE,
	LHCS_DUMP_HEADERS,
	LHCS_PAYLOAD,
	LCHS_SINGLE_0A,
};

struct lws_cgi_args {
	struct lws **stdwsi; /**< get fd with lws_get_socket_fd() */
	enum lws_enum_stdinouterr ch; /**< channel index */
	unsigned char *data; /**< for messages with payload */
	enum lws_cgi_hdr_state hdr_state; /**< track where we are in cgi headers */
	int len; /**< length */
};

/** struct lws_cgi_info - parameters to spawn network-connected cgi
 *                        process when using lws_cgi_via_info() */
struct lws_cgi_info {
	struct lws *wsi;
	/**< connection to own the process */
	const char * const *exec_array;
	/**< array of "exec-name" "arg1" ... "argn" NULL */
	int script_uri_path_len;
	/**< how many chars on the left of the uri are the path to the
	 * cgi, or -1 to spawn without URL-related env vars */
	int timeout_secs;
	/**< seconds script should be allowed to run */
	const struct lws_protocol_vhost_options *mp_cgienv;
	/**< pvo list with per-vhost cgi options to put in env */
	const char *chroot_path;
	/**< NULL, or chroot patch for child process */
	const char *wd;
	/**< working directory to cd to after fork, NULL defaults to /tmp */
};

#ifdef LWS_WITH_CGI
/**
 * lws_cgi_via_info() - Spawn network-connected cgi process
 * \param cgiinfo: pointer to lws_cgi_info struct
 */
LWS_VISIBLE LWS_EXTERN int lws_cgi_via_info(struct lws_cgi_info * cgiinfo);

/**
 * lws_cgi: spawn network-connected cgi process
 *
 * \param wsi: connection to own the process
 * \param exec_array: array of "exec-name" "arg1" ... "argn" NULL
 * \param script_uri_path_len: how many chars on the left of the uri are the
 *        path to the cgi, or -1 to spawn without URL-related env vars
 * \param timeout_secs: seconds script should be allowed to run
 * \param mp_cgienv: pvo list with per-vhost cgi options to put in env
 */
LWS_VISIBLE LWS_EXTERN int
lws_cgi(struct lws *wsi, const char * const *exec_array,
	int script_uri_path_len, int timeout_secs,
	const struct lws_protocol_vhost_options *mp_cgienv);

/**
 * lws_cgi_write_split_stdout_headers: write cgi output accounting for header part
 *
 * \param wsi: connection to own the process
 */
LWS_VISIBLE LWS_EXTERN int
lws_cgi_write_split_stdout_headers(struct lws *wsi);

/**
 * lws_cgi_kill: terminate cgi process associated with wsi
 *
 * \param wsi: connection to own the process
 */
LWS_VISIBLE LWS_EXTERN int
lws_cgi_kill(struct lws *wsi);

/**
 * lws_cgi_get_stdwsi: get wsi for stdin, stdout, or stderr
 *
 * \param wsi: parent wsi that has cgi
 * \param ch: which of LWS_STDIN, LWS_STDOUT or LWS_STDERR
 */
LWS_VISIBLE LWS_EXTERN struct lws *
lws_cgi_get_stdwsi(struct lws *wsi, enum lws_enum_stdinouterr ch);

#endif
///@}