/*
* 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 str[128];
int len;
};
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 + 256], *start = &buf[LWS_PRE], *p = start,
*end = &buf[sizeof(buf) - 1];
time_t t;
switch (reason) {
case LWS_CALLBACK_HTTP:
/* in contains the url part after our mountpoint /dyn, if any */
t = time(NULL);
pss->len = lws_snprintf(pss->str, sizeof(pss->str),
"<html>"
"<img src=\"/libwebsockets.org-logo.png\">"
"<br>Dynamic content for '%s' from mountpoint."
"<br>Time: %s"
"</html>", (const char *)in, ctime(&t));
/* prepare and write http headers */
if (lws_add_http_common_headers(wsi, HTTP_STATUS_OK,
"text/html", pss->len, &p, end))
return 1;
if (lws_finalize_write_http_header(wsi, start, &p, end))
return 1;
/* write the body separately */
lws_callback_on_writable(wsi);
return 0;
case LWS_CALLBACK_HTTP_WRITEABLE:
if (!pss || !pss->len)
break;
/*
* Use LWS_WRITE_HTTP for intermediate writes, on http/2
* lws uses this to understand to end the stream with this
* frame
*/
if (lws_write(wsi, (uint8_t *)pss->str, pss->len,
LWS_WRITE_HTTP_FINAL) != pss->len)
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 (lws_http_transaction_completed(wsi))
return -1;
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.port = 7681;
info.protocols = protocols;
info.mounts = &mount;
/* 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;
}
while (n >= 0 && !interrupted)
n = lws_service(context, 1000);
lws_context_destroy(context);
return 0;
}