minimal-examples/http-server/minimal-http-server-dynamic/minimal-http-server-dynamic.c - platform/external/libwebsockets - Git at Google

 /*
  * lws-minimal-http-server-dynamic
  *
  * Copyright (C) 2018 Andy Green <andy@warmcat.com>
  *
  * This file is made available under the Creative Commons CC0 1.0
  * Universal Public Domain Dedication.
  *
  * This demonstrates a minimal http server that can produce dynamic http
  * content as well as static content.
  *
  * To keep it simple, it serves the static stuff from the subdirectory
  * "./mount-origin" of the directory it was started in.
  *
  * You can change that by changing mount.origin below.
  */

 #include <libwebsockets.h>
 #include <string.h>
 #include <signal.h>
 #include <time.h>

 /*
  * Unlike ws, http is a stateless protocol.  This pss only exists for the
  * duration of a single http transaction.  With http/1.1 keep-alive and http/2,
  * that is unrelated to (shorter than) the lifetime of the network connection.
  */
 struct pss {
 	char path[128];

 	int times;
 	int budget;

 	int content_lines;
 };

 static int interrupted;

 static int
 callback_dynamic_http(struct lws *wsi, enum lws_callback_reasons reason,
 			void *user, void *in, size_t len)
 {
 	struct pss *pss = (struct pss *)user;
 	uint8_t buf[LWS_PRE + 2048], *start = &buf[LWS_PRE], *p = start,
 		*end = &buf[sizeof(buf) - LWS_PRE - 1];
 	time_t t;
 	int n;

 	switch (reason) {
 	case LWS_CALLBACK_HTTP:

 		/* in contains the url part after our mountpoint /dyn, if any */
 		lws_snprintf(pss->path, sizeof(pss->path), "%s", (const char *)in);

 		/*
 		 * prepare and write http headers... with regards to content-
 		 * length, there are three approaches:
 		 *
 		 *  - http/1.0 or connection:close: no need, but no pipelining
 		 *  - http/1.1 or connected:keep-alive
 		 *     (keep-alive is default for 1.1): content-length required
 		 *  - http/2: no need, LWS_WRITE_HTTP_FINAL closes the stream
 		 *
 		 * giving the api below LWS_ILLEGAL_HTTP_CONTENT_LEN instead of
 		 * a content length forces the connection response headers to
 		 * send back "connection: close", disabling keep-alive.
 		 *
 		 * If you know the final content-length, it's always OK to give
 		 * it and keep-alive can work then if otherwise possible.  But
 		 * often you don't know it and avoiding having to compute it
 		 * at header-time makes life easier at the server.
 		 */
 		if (lws_add_http_common_headers(wsi, HTTP_STATUS_OK,
 				"text/html",
 				LWS_ILLEGAL_HTTP_CONTENT_LEN, /* no content len */
 				&p, end))
 			return 1;
 		if (lws_finalize_write_http_header(wsi, start, &p, end))
 			return 1;

 		pss->times = 0;
 		pss->budget = atoi((char *)in + 1);
 		pss->content_lines = 0;
 		if (!pss->budget)
 			pss->budget = 10;

 		/* write the body separately */
 		lws_callback_on_writable(wsi);

 		return 0;

 	case LWS_CALLBACK_HTTP_WRITEABLE:

 		if (!pss || pss->times > pss->budget)
 			break;

 		/*
 		 * We send a large reply in pieces of around 2KB each.
 		 *
 		 * For http/1, it's possible to send a large buffer at once,
 		 * but lws will malloc() up a temp buffer to hold any data
 		 * that the kernel didn't accept in one go.  This is expensive
 		 * in memory and cpu, so it's better to stage the creation of
 		 * the data to be sent each time.
 		 *
 		 * For http/2, large data frames would block the whole
 		 * connection, not just the stream and are not allowed.  Lws
 		 * will call back on writable when the stream both has transmit
 		 * credit and the round-robin fair access for sibling streams
 		 * allows it.
 		 *
 		 * For http/2, we must send the last part with
 		 * LWS_WRITE_HTTP_FINAL to close the stream representing
 		 * this transaction.
 		 */
 		n = LWS_WRITE_HTTP;
 		if (pss->times == pss->budget)
 			n = LWS_WRITE_HTTP_FINAL;

 		if (!pss->times) {
 			/*
 			 * the first time, we print some html title
 			 */
 			t = time(NULL);
 			/*
 			 * to work with http/2, we must take care about LWS_PRE
 			 * valid behind the buffer we will send.
 			 */
 			p += lws_snprintf((char *)p, end - p, "<html>"
 				"<img src=\"/libwebsockets.org-logo.png\">"
 				"<br>Dynamic content for '%s' from mountpoint."
 				"<br>Time: %s<br><br>"
 				"</html>", pss->path, ctime(&t));
 		} else {
 			/*
 			 * after the first time, we create bulk content.
 			 *
 			 * Again we take care about LWS_PRE valid behind the
 			 * buffer we will send.
 			 */

 			while (lws_ptr_diff(end, p) > 80)
 				p += lws_snprintf((char *)p, end - p,
 					"%d.%d: this is some content... ",
 					pss->times, pss->content_lines++);

 			p += lws_snprintf((char *)p, end - p, "<br><br>");
 		}

 		pss->times++;
 		if (lws_write(wsi, (uint8_t *)start, lws_ptr_diff(p, start), n) !=
 				lws_ptr_diff(p, start))
 			return 1;

 		/*
 		 * HTTP/1.0 no keepalive: close network connection
 		 * HTTP/1.1 or HTTP1.0 + KA: wait / process next transaction
 		 * HTTP/2: stream ended, parent connection remains up
 		 */
 		if (n == LWS_WRITE_HTTP_FINAL) {
 		    if (lws_http_transaction_completed(wsi))
 			return -1;
 		} else
 			lws_callback_on_writable(wsi);

 		return 0;

 	default:
 		break;
 	}

 	return lws_callback_http_dummy(wsi, reason, user, in, len);
 }

 static struct lws_protocols protocols[] = {
 	{ "http", callback_dynamic_http, sizeof(struct pss), 0 },
 	{ NULL, NULL, 0, 0 } /* terminator */
 };

 /* override the default mount for /dyn in the URL space */

 static const struct lws_http_mount mount_dyn = {
 	/* .mount_next */		NULL,		/* linked-list "next" */
 	/* .mountpoint */		"/dyn",		/* mountpoint URL */
 	/* .origin */			NULL,	/* protocol */
 	/* .def */			NULL,
 	/* .protocol */			"http",
 	/* .cgienv */			NULL,
 	/* .extra_mimetypes */		NULL,
 	/* .interpret */		NULL,
 	/* .cgi_timeout */		0,
 	/* .cache_max_age */		0,
 	/* .auth_mask */		0,
 	/* .cache_reusable */		0,
 	/* .cache_revalidate */		0,
 	/* .cache_intermediaries */	0,
 	/* .origin_protocol */		LWSMPRO_CALLBACK, /* dynamic */
 	/* .mountpoint_len */		4,		/* char count */
 	/* .basic_auth_login_file */	NULL,
 };

 /* default mount serves the URL space from ./mount-origin */

 static const struct lws_http_mount mount = {
 	/* .mount_next */	&mount_dyn,		/* linked-list "next" */
 	/* .mountpoint */		"/",		/* mountpoint URL */
 	/* .origin */		"./mount-origin",	/* serve from dir */
 	/* .def */			"index.html",	/* default filename */
 	/* .protocol */			NULL,
 	/* .cgienv */			NULL,
 	/* .extra_mimetypes */		NULL,
 	/* .interpret */		NULL,
 	/* .cgi_timeout */		0,
 	/* .cache_max_age */		0,
 	/* .auth_mask */		0,
 	/* .cache_reusable */		0,
 	/* .cache_revalidate */		0,
 	/* .cache_intermediaries */	0,
 	/* .origin_protocol */		LWSMPRO_FILE,	/* files in a dir */
 	/* .mountpoint_len */		1,		/* char count */
 	/* .basic_auth_login_file */	NULL,
 };

 void sigint_handler(int sig)
 {
 	interrupted = 1;
 }

 int main(int argc, const char **argv)
 {
 	struct lws_context_creation_info info;
 	struct lws_context *context;
 	const char *p;
 	int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
 			/* for LLL_ verbosity above NOTICE to be built into lws,
 			 * lws must have been configured and built with
 			 * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
 			/* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */
 			/* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */
 			/* | LLL_DEBUG */;

 	signal(SIGINT, sigint_handler);

 	if ((p = lws_cmdline_option(argc, argv, "-d")))
 		logs = atoi(p);

 	lws_set_log_level(logs, NULL);
 	lwsl_user("LWS minimal http server dynamic | visit http://localhost:7681\n");

 	memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
 	info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT |
 		       LWS_SERVER_OPTION_EXPLICIT_VHOSTS;

 	/* for testing ah queue, not useful in real world */
 	if (lws_cmdline_option(argc, argv, "--ah1"))
 		info.max_http_header_pool = 1;

 	context = lws_create_context(&info);
 	if (!context) {
 		lwsl_err("lws init failed\n");
 		return 1;
 	}

 	/* http on 7681 */

 	info.port = 7681;
 	info.protocols = protocols;
 	info.mounts = &mount;
 	info.vhost_name = "http";

 	if (!lws_create_vhost(context, &info)) {
 		lwsl_err("Failed to create tls vhost\n");
 		goto bail;
 	}

 	/* https on 7682 */

 	info.port = 7682;
 	info.error_document_404 = "/404.html";
 	info.ssl_cert_filepath = "localhost-100y.cert";
 	info.ssl_private_key_filepath = "localhost-100y.key";
 	info.vhost_name = "localhost";

 	if (!lws_create_vhost(context, &info)) {
 		lwsl_err("Failed to create tls vhost\n");
 		goto bail;
 	}

 	while (n >= 0 && !interrupted)
 		n = lws_service(context, 1000);

 bail:
 	lws_context_destroy(context);

 	return 0;
 }
	/*
	* lws-minimal-http-server-dynamic
	*
	* Copyright (C) 2018 Andy Green <andy@warmcat.com>
	*
	* This file is made available under the Creative Commons CC0 1.0
	* Universal Public Domain Dedication.
	*
	* This demonstrates a minimal http server that can produce dynamic http
	* content as well as static content.
	*
	* To keep it simple, it serves the static stuff from the subdirectory
	* "./mount-origin" of the directory it was started in.
	*
	* You can change that by changing mount.origin below.
	*/

	#include <libwebsockets.h>
	#include <string.h>
	#include <signal.h>
	#include <time.h>

	/*
	* Unlike ws, http is a stateless protocol. This pss only exists for the
	* duration of a single http transaction. With http/1.1 keep-alive and http/2,
	* that is unrelated to (shorter than) the lifetime of the network connection.
	*/
	struct pss {
	char path[128];

	int times;
	int budget;

	int content_lines;
	};

	static int interrupted;

	static int
	callback_dynamic_http(struct lws *wsi, enum lws_callback_reasons reason,
	void user, void in, size_t len)
	{
	struct pss pss = (struct pss )user;
	uint8_t buf[LWS_PRE + 2048], start = &buf[LWS_PRE], p = start,
	*end = &buf[sizeof(buf) - LWS_PRE - 1];
	time_t t;
	int n;

	switch (reason) {
	case LWS_CALLBACK_HTTP:

	/* in contains the url part after our mountpoint /dyn, if any */
	lws_snprintf(pss->path, sizeof(pss->path), "%s", (const char *)in);

	/*
	* prepare and write http headers... with regards to content-
	* length, there are three approaches:
	*
	* - http/1.0 or connection:close: no need, but no pipelining
	* - http/1.1 or connected:keep-alive
	* (keep-alive is default for 1.1): content-length required
	* - http/2: no need, LWS_WRITE_HTTP_FINAL closes the stream
	*
	* giving the api below LWS_ILLEGAL_HTTP_CONTENT_LEN instead of
	* a content length forces the connection response headers to
	* send back "connection: close", disabling keep-alive.
	*
	* If you know the final content-length, it's always OK to give
	* it and keep-alive can work then if otherwise possible. But
	* often you don't know it and avoiding having to compute it
	* at header-time makes life easier at the server.
	*/
	if (lws_add_http_common_headers(wsi, HTTP_STATUS_OK,
	"text/html",
	LWS_ILLEGAL_HTTP_CONTENT_LEN, /* no content len */
	&p, end))
	return 1;
	if (lws_finalize_write_http_header(wsi, start, &p, end))
	return 1;

	pss->times = 0;
	pss->budget = atoi((char *)in + 1);
	pss->content_lines = 0;
	if (!pss->budget)
	pss->budget = 10;

	/* write the body separately */
	lws_callback_on_writable(wsi);

	return 0;

	case LWS_CALLBACK_HTTP_WRITEABLE:

	if (!pss \|\| pss->times > pss->budget)
	break;

	/*
	* We send a large reply in pieces of around 2KB each.
	*
	* For http/1, it's possible to send a large buffer at once,
	* but lws will malloc() up a temp buffer to hold any data
	* that the kernel didn't accept in one go. This is expensive
	* in memory and cpu, so it's better to stage the creation of
	* the data to be sent each time.
	*
	* For http/2, large data frames would block the whole
	* connection, not just the stream and are not allowed. Lws
	* will call back on writable when the stream both has transmit
	* credit and the round-robin fair access for sibling streams
	* allows it.
	*
	* For http/2, we must send the last part with
	* LWS_WRITE_HTTP_FINAL to close the stream representing
	* this transaction.
	*/
	n = LWS_WRITE_HTTP;
	if (pss->times == pss->budget)
	n = LWS_WRITE_HTTP_FINAL;

	if (!pss->times) {
	/*
	* the first time, we print some html title
	*/
	t = time(NULL);
	/*
	* to work with http/2, we must take care about LWS_PRE
	* valid behind the buffer we will send.
	*/
	p += lws_snprintf((char *)p, end - p, "<html>"
	"<img src=\"/libwebsockets.org-logo.png\">"
	"<br>Dynamic content for '%s' from mountpoint."
	"<br>Time: %s<br><br>"
	"</html>", pss->path, ctime(&t));
	} else {
	/*
	* after the first time, we create bulk content.
	*
	* Again we take care about LWS_PRE valid behind the
	* buffer we will send.
	*/

	while (lws_ptr_diff(end, p) > 80)
	p += lws_snprintf((char *)p, end - p,
	"%d.%d: this is some content... ",
	pss->times, pss->content_lines++);

	p += lws_snprintf((char *)p, end - p, "<br><br>");
	}

	pss->times++;
	if (lws_write(wsi, (uint8_t *)start, lws_ptr_diff(p, start), n) !=
	lws_ptr_diff(p, start))
	return 1;

	/*
	* HTTP/1.0 no keepalive: close network connection
	* HTTP/1.1 or HTTP1.0 + KA: wait / process next transaction
	* HTTP/2: stream ended, parent connection remains up
	*/
	if (n == LWS_WRITE_HTTP_FINAL) {
	if (lws_http_transaction_completed(wsi))
	return -1;
	} else
	lws_callback_on_writable(wsi);

	return 0;

	default:
	break;
	}

	return lws_callback_http_dummy(wsi, reason, user, in, len);
	}

	static struct lws_protocols protocols[] = {
	{ "http", callback_dynamic_http, sizeof(struct pss), 0 },
	{ NULL, NULL, 0, 0 } /* terminator */
	};

	/* override the default mount for /dyn in the URL space */

	static const struct lws_http_mount mount_dyn = {
	/* .mount_next / NULL, / linked-list "next" */
	/* .mountpoint / "/dyn", / mountpoint URL */
	/* .origin / NULL, / protocol */
	/* .def */ NULL,
	/* .protocol */ "http",
	/* .cgienv */ NULL,
	/* .extra_mimetypes */ NULL,
	/* .interpret */ NULL,
	/* .cgi_timeout */ 0,
	/* .cache_max_age */ 0,
	/* .auth_mask */ 0,
	/* .cache_reusable */ 0,
	/* .cache_revalidate */ 0,
	/* .cache_intermediaries */ 0,
	/* .origin_protocol / LWSMPRO_CALLBACK, / dynamic */
	/* .mountpoint_len / 4, / char count */
	/* .basic_auth_login_file */ NULL,
	};

	/* default mount serves the URL space from ./mount-origin */

	static const struct lws_http_mount mount = {
	/* .mount_next / &mount_dyn, / linked-list "next" */
	/* .mountpoint / "/", / mountpoint URL */
	/* .origin / "./mount-origin", / serve from dir */
	/* .def / "index.html", / default filename */
	/* .protocol */ NULL,
	/* .cgienv */ NULL,
	/* .extra_mimetypes */ NULL,
	/* .interpret */ NULL,
	/* .cgi_timeout */ 0,
	/* .cache_max_age */ 0,
	/* .auth_mask */ 0,
	/* .cache_reusable */ 0,
	/* .cache_revalidate */ 0,
	/* .cache_intermediaries */ 0,
	/* .origin_protocol / LWSMPRO_FILE, / files in a dir */
	/* .mountpoint_len / 1, / char count */
	/* .basic_auth_login_file */ NULL,
	};

	void sigint_handler(int sig)
	{
	interrupted = 1;
	}

	int main(int argc, const char **argv)
	{
	struct lws_context_creation_info info;
	struct lws_context *context;
	const char *p;
	int n = 0, logs = LLL_USER \| LLL_ERR \| LLL_WARN \| LLL_NOTICE
	/* for LLL_ verbosity above NOTICE to be built into lws,
	* lws must have been configured and built with
	* -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
	/* \| LLL_INFO / / \| LLL_PARSER / / \| LLL_HEADER */
	/* \| LLL_EXT / / \| LLL_CLIENT / / \| LLL_LATENCY */
	/* \| LLL_DEBUG */;

	signal(SIGINT, sigint_handler);

	if ((p = lws_cmdline_option(argc, argv, "-d")))
	logs = atoi(p);

	lws_set_log_level(logs, NULL);
	lwsl_user("LWS minimal http server dynamic \| visit http://localhost:7681\n");

	memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
	info.options = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT \|
	LWS_SERVER_OPTION_EXPLICIT_VHOSTS;

	/* for testing ah queue, not useful in real world */
	if (lws_cmdline_option(argc, argv, "--ah1"))
	info.max_http_header_pool = 1;

	context = lws_create_context(&info);
	if (!context) {
	lwsl_err("lws init failed\n");
	return 1;
	}

	/* http on 7681 */

	info.port = 7681;
	info.protocols = protocols;
	info.mounts = &mount;
	info.vhost_name = "http";

	if (!lws_create_vhost(context, &info)) {
	lwsl_err("Failed to create tls vhost\n");
	goto bail;
	}

	/* https on 7682 */

	info.port = 7682;
	info.error_document_404 = "/404.html";
	info.ssl_cert_filepath = "localhost-100y.cert";
	info.ssl_private_key_filepath = "localhost-100y.key";
	info.vhost_name = "localhost";

	if (!lws_create_vhost(context, &info)) {
	lwsl_err("Failed to create tls vhost\n");
	goto bail;
	}

	while (n >= 0 && !interrupted)
	n = lws_service(context, 1000);

	bail:
	lws_context_destroy(context);

	return 0;
	}