[httpd/websocket/conf] Initial websocket implementation

If enabled (default) requires libwebsockets >= 2.0.2, can be disabled
with configure option --disable-websocket.
This commit is contained in:
chme 2017-08-12 20:01:57 +02:00
parent 0abf195347
commit 75eb5420fd
5 changed files with 393 additions and 1 deletions

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@ -259,6 +259,10 @@ dnl Build with libcurl
FORK_ARG_WITH_CHECK([FORKED_OPTS], [libcurl support], [libcurl], [LIBCURL],
[libcurl], [curl_global_init], [curl/curl.h])
dnl Build with libwebsockets
FORK_ARG_WITH_CHECK([FORKED_OPTS], [libwebsockets support], [libwebsockets], [LIBWEBSOCKETS],
[libwebsockets >= 2.0.2])
dnl Build with libsodium
FORK_ARG_WITH_CHECK([FORKED_OPTS], [libsodium support], [libsodium], [LIBSODIUM],
[libsodium], [sodium_init], [sodium.h])
@ -340,6 +344,12 @@ FORK_ARG_ENABLE([Chromecast support], [chromecast], [CHROMECAST],
AM_CONDITIONAL([COND_CHROMECAST], [[test "x$enable_chromecast" = "xyes"]])
AM_CONDITIONAL([COND_PROTOBUF_OLD], [[test "x$protobuf_old" = "xyes"]])
dnl Websocket support with libwebsockets
FORK_ARG_DISABLE([Websocket support], [websocket], [WEBSOCKET],
[AS_IF([[test "x$with_libwebsockets" = "xno"]],
[AC_MSG_ERROR([[Websocket support requires libwebsockets]])])])
AM_CONDITIONAL([COND_WEBSOCKET], [[test "x$enable_websocket" = "xyes"]])
dnl iTunes playlists with libplist
FORK_ARG_DISABLE([iTunes Music Library XML support], [itunes], [ITUNES],
[AS_IF([[test "x$with_libplist" = "xno"]],

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@ -43,6 +43,10 @@ else
MDNS_SRC=mdns_dnssd.c
endif
if COND_WEBSOCKET
WEBSOCKET_SRC=websocket.c websocket.h
endif
if COND_FFMPEG_LEGACY
FFMPEG_SRC=transcode_legacy.c artwork_legacy.c ffmpeg-compat.h
else
@ -133,8 +137,9 @@ forked_daapd_SOURCES = main.c \
listener.c listener.h \
commands.c commands.h \
mxml-compat.h \
$(WEBSOCKET_SRC) \
$(GPERF_SRC) \
$(ANTLR_SRC)
$(ANTLR_SRC)
# built by maintainers, and distributed. Clean with maintainer-clean
BUILT_SOURCES = \

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@ -68,6 +68,10 @@
#ifdef HAVE_SPOTIFY_H
# include "spotify.h"
#endif
#ifdef WEBSOCKET
# include "websocket.h"
#endif
/*
* HTTP client quirks by User-Agent, from mt-daapd
@ -1510,6 +1514,16 @@ httpd_init(void)
goto jsonapi_fail;
}
#ifdef WEBSOCKET
ret = websocket_init();
if (ret < 0)
{
DPRINTF(E_FATAL, L_HTTPD, "Websocket init failed\n");
goto websocket_fail;
}
#endif
streaming_init();
#ifdef HAVE_EVENTFD
@ -1616,6 +1630,10 @@ httpd_init(void)
#endif
pipe_fail:
streaming_deinit();
#ifdef WEBSOCKET
websocket_deinit();
#endif
websocket_fail:
jsonapi_deinit();
jsonapi_fail:
dacp_deinit();
@ -1664,6 +1682,9 @@ httpd_deinit(void)
}
streaming_deinit();
#ifdef WEBSOCKET
websocket_deinit();
#endif
jsonapi_deinit();
rsp_deinit();
dacp_deinit();

327
src/websocket.c Normal file
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@ -0,0 +1,327 @@
/*
* Copyright (C) 2017 Christian Meffert <christian.meffert@googlemail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <json.h>
#include <libwebsockets.h>
#include <pthread.h>
#ifdef HAVE_PTHREAD_NP_H
# include <pthread_np.h>
#endif
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include "conffile.h"
#include "listener.h"
#include "logger.h"
static struct lws_context *context;
static pthread_t tid_websocket;
static int websocket_port;
static bool ws_exit = false;
// Event mask of events to notify websocket clients
static short events;
// Event mask of events processed by the writeable callback
static short write_events;
/* Thread: library (the thread the event occurred) */
static void
listener_cb(enum listener_event_type type)
{
// Add event to the event mask, clients will be notified at the next break of the libwebsockets service loop
events |= type;
}
/*
* Libwebsocket requires the HTTP protocol to be the first supported protocol
*
* This adds an empty implementation, because we are serving HTTP over libevent in httpd.h.
*/
static int
callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len)
{
return 0;
}
/*
* Each session of the "notify" protocol holds this event mask
*
* The client sends the events it wants to be notified of and the event mask is
* set accordingly translating them to the LISTENER enum (see listener.h)
*/
struct ws_session_data_notify
{
short events;
};
/*
* Processes client requests to the notify-protocol
*
* Expects the message in "in" to be a JSON string of the form:
*
* {
* "notify": [ "update" ]
* }
*/
static int
process_notify_request(struct ws_session_data_notify *session_data, void *in, size_t len)
{
json_tokener *tokener;
json_object *request;
json_object *item;
int count, i;
enum json_tokener_error jerr;
json_object *needle;
const char *event_type;
memset(session_data, 0, sizeof(struct ws_session_data_notify));
tokener = json_tokener_new();
request = json_tokener_parse_ex(tokener, in, len);
jerr = json_tokener_get_error(tokener);
if (jerr != json_tokener_success)
{
DPRINTF(E_LOG, L_WEB, "Failed to parse incoming request: %s\n", json_tokener_error_desc(jerr));
json_tokener_free(tokener);
return -1;
}
DPRINTF(E_DBG, L_WEB, "notify callback request: %s\n", json_object_to_json_string(request));
if (json_object_object_get_ex(request, "notify", &needle) && json_object_get_type(needle) == json_type_array)
{
count = json_object_array_length(needle);
for (i = 0; i < count; i++)
{
item = json_object_array_get_idx(needle, i);
if (json_object_get_type(item) == json_type_string)
{
event_type = json_object_get_string(item);
DPRINTF(E_DBG, L_WEB, "notify callback event received: %s\n", event_type);
if (0 == strcmp(event_type, "update"))
{
session_data->events |= LISTENER_UPDATE;
}
else if (0 == strcmp(event_type, "pairing"))
{
session_data->events |= LISTENER_PAIRING;
}
else if (0 == strcmp(event_type, "spotify"))
{
session_data->events |= LISTENER_SPOTIFY;
}
}
}
}
json_tokener_free(tokener);
json_object_put(request);
return 0;
}
/*
* Notify clients of the notify-protocol about occurred events
*
* Sends a JSON message of the form:
*
* {
* "notify": [ "update" ]
* }
*/
static void
send_notify_reply(short events, struct lws* wsi)
{
unsigned char* buf;
const char* json_response;
json_object* reply;
json_object* notify;
notify = json_object_new_array();
if (events & LISTENER_UPDATE)
{
json_object_array_add(notify, json_object_new_string("update"));
}
if (events & LISTENER_PAIRING)
{
json_object_array_add(notify, json_object_new_string("pairing"));
}
if (events & LISTENER_SPOTIFY)
{
json_object_array_add(notify, json_object_new_string("spotify"));
}
reply = json_object_new_object();
json_object_object_add(reply, "notify", notify);
json_response = json_object_to_json_string(reply);
buf = malloc(LWS_PRE + strlen(json_response));
memcpy(&buf[LWS_PRE], json_response, strlen(json_response));
lws_write(wsi, &buf[LWS_PRE], strlen(json_response), LWS_WRITE_TEXT);
free(buf);
json_object_put(reply);
}
/*
* Callback for the "notify" protocol
*/
static int
callback_notify(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len)
{
struct ws_session_data_notify *session_data = user;
int ret = 0;
DPRINTF(E_DBG, L_WEB, "notify callback reason: %d\n", reason);
switch (reason)
{
case LWS_CALLBACK_ESTABLISHED:
// Initialize session data for new connections
memset(session_data, 0, sizeof(struct ws_session_data_notify));
break;
case LWS_CALLBACK_RECEIVE:
ret = process_notify_request(session_data, in, len);
break;
case LWS_CALLBACK_SERVER_WRITEABLE:
if (write_events)
{
send_notify_reply(write_events, wsi);
}
break;
default:
break;
}
return ret;
}
/*
* Supported protocols of the websocket, needs to be in line with the protocols array
*/
enum ws_protocols
{
WS_PROTOCOL_HTTP = 0,
WS_PROTOCOL_NOTIFY,
};
static struct lws_protocols protocols[] =
{
// The first protocol must always be the HTTP handler
{
"http-only", // Protocol name
callback_http, // Callback function
0, // Size of per session data
0, // Frame size / rx buffer (0 = max frame size)
},
{
"notify",
callback_notify,
sizeof(struct ws_session_data_notify),
0,
},
{ NULL, NULL, 0, 0 } // terminator
};
/* Thread: websocket */
static void *
websocket(void *arg)
{
listener_add(listener_cb, LISTENER_UPDATE | LISTENER_PAIRING | LISTENER_SPOTIFY);
while(!ws_exit)
{
lws_service(context, 1000);
if (events)
{
write_events = events;
events = 0;
lws_callback_on_writable_all_protocol(context, &protocols[WS_PROTOCOL_NOTIFY]);
}
}
lws_context_destroy(context);
pthread_exit(NULL);
}
int
websocket_init(void)
{
struct lws_context_creation_info info;
int ret;
websocket_port = cfg_getint(cfg_getsec(cfg, "general"), "websocket_port");
if (websocket_port <= 0)
{
DPRINTF(E_LOG, L_WEB, "Websocket disabled. To enable it, set websocket_port in config to a valid port number.\n");
return 0;
}
memset(&info, 0, sizeof(info));
info.port = websocket_port;
info.protocols = protocols;
info.gid = -1;
info.uid = -1;
context = lws_create_context(&info);
if (context == NULL)
{
DPRINTF(E_LOG, L_WEB, "Failed to create websocket context\n");
return -1;
}
ret = pthread_create(&tid_websocket, NULL, websocket, NULL);
if (ret < 0)
{
DPRINTF(E_LOG, L_WEB, "Could not spawn websocket thread: %s\n", strerror(errno));
lws_context_destroy(context);
return -1;
}
return 0;
}
void
websocket_deinit(void)
{
if (websocket_port > 0)
{
ws_exit = true;
pthread_join(tid_websocket, NULL);
}
}

29
src/websocket.h Normal file
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@ -0,0 +1,29 @@
/*
* Copyright (C) 2017 Christian Meffert <christian.meffert@googlemail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef SRC_WEBSOCKET_H_
#define SRC_WEBSOCKET_H_
int
websocket_init(void);
void
websocket_deinit(void);
#endif /* SRC_WEBSOCKET_H_ */