systemd socket activation

README.md

@@ -17,6 +17,7 @@
 | [DV-timings](https://linuxtv.org/downloads/v4l-dvb-apis-new/userspace-api/v4l/dv-timings.html) support -<br>the ability to change resolution<br>on the fly by source signal | ✔ | ☹ Partially yes <sup>1</sup> |
 | Option to skip frames when streaming<br>static images by HTTP to save the traffic | ✔ <sup>2</sup> | ✘ |
 | Streaming via UNIX domain socket | ✔ | ✘ |
+| Systemd socket activation | ✔ | ✘ |
 | Debug logs without recompiling,<br>performance statistics log,<br>access to HTTP streaming parameters | ✔ | ✘ |
 | Option to serve files<br>with a built-in HTTP server | ✔ | ☹ Regular files only |
 | Signaling about the stream state<br>on GPIO using [libgpiod](https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/about) | ✔ | ✘ |

README.ru.md

@@ -17,6 +17,7 @@
 | Поддержка [DV-таймингов](https://linuxtv.org/downloads/v4l-dvb-apis-new/userspace-api/v4l/dv-timings.html) - возможности<br>изменения  параметров разрешения<br>трансляции на лету по сигналу<br>источника (устройства видеозахвата) | ✔ | ☹ Условно есть <sup>1</sup> |
 | Возможность пропуска фреймов при передаче<br>статического изображения по HTTP<br>для экономии трафика | ✔ <sup>2</sup> | ✘ |
 | Стрим через UNIX domain socket | ✔ | ✘ |
+| Systemd socket activation | ✔ | ✘ |
 | Дебаг-логи без перекомпиляции,<br>логгирование статистики производительности,<br>возможность получения параметров<br>трансляции по HTTP | ✔ | ✘ |
 | Возможность сервить файлы встроенным<br>HTTP-сервером  | ✔ | ☹ Нет каталогов |
 | Вывод сигналов о состоянии стрима на GPIO<br>с помощью [libgpiod](https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/about) | ✔ | ✘ |

man/ustreamer.1

@@ -173,6 +173,9 @@ Try to remove old unix socket file before binding. default: disabled.
 .BR \-M\ \fImode ", " \-\-unix\-mode\ \fImode
 Set UNIX socket file permissions (like 777). Default: disabled.
 .TP
+.BR \-\-systemd
+Bind to systemd socket for socket activation. Required \fBWITH_SYSTEMD\fR feature. Default: disabled.
+.TP
 .BR \-\-user\ \fIname
 HTTP basic auth user. Default: disabled.
 .TP
@@ -189,7 +192,7 @@ Don't send identical frames to clients, but no more than specified number. It ca
 Override image resolution for the /state. Default: disabled.
 .TP
 .BR \-\-tcp\-nodelay
-Set TCP_NODELAY flag to the client /stream socket. Ignored for \-\-unix.
+Set TCP_NODELAY flag to the client /stream socket. Only for TCP socket.
 Default: disabled.
 .TP
 .BR \-\-allow\-origin\ \fIstr

pkg/arch/PKGBUILD

@@ -31,6 +31,11 @@ if [ -e /usr/include/janus/plugins/plugin.h ];then
 	makedepends+=(janus-gateway-pikvm)
 	_options="$_options WITH_JANUS=1"
 fi
+if [ -e /usr/include/systemd/sd-daemon.h ];then
+	depends+=(systemd)
+	makedepends+=(systemd)
+	_options="$_options WITH_SYSTEMD=1"
+fi
 
 
 # LD does not link mmal with this option

src/Makefile

@@ -59,6 +59,13 @@ _USTR_SRCS += $(shell ls ustreamer/gpio/*.c)
 endif
 
 
+ifneq ($(call optbool,$(WITH_SYSTEMD)),)
+_USTR_LIBS += -lsystemd
+override _CFLAGS += -DWITH_SYSTEMD
+_USTR_SRCS += $(shell ls ustreamer/http/systemd/*.c)
+endif
+
+
 WITH_PTHREAD_NP ?= 1
 ifneq ($(call optbool,$(WITH_PTHREAD_NP)),)
 override _CFLAGS += -DWITH_PTHREAD_NP

src/ustreamer/http/server.c

@@ -86,8 +86,8 @@ void server_destroy(server_s *server) {
 	}
 
 	evhttp_free(RUN(http));
-	if (RUN(unix_fd)) {
+	if (RUN(ext_fd)) {
-		close(RUN(unix_fd));
+		close(RUN(ext_fd));
 	}
 	event_base_free(RUN(base));
 
@@ -160,7 +160,7 @@ int server_listen(server_s *server) {
 
 	if (server->unix_path[0] != '\0') {
 		LOG_DEBUG("Binding HTTP to UNIX socket '%s' ...", server->unix_path);
-		if ((RUN(unix_fd) = evhttp_my_bind_unix(
+		if ((RUN(ext_fd) = evhttp_my_bind_unix(
 			RUN(http),
 			server->unix_path,
 			server->unix_rm,
@@ -169,9 +169,16 @@ int server_listen(server_s *server) {
 			return -1;
 		}
 		LOG_INFO("Listening HTTP on UNIX socket '%s'", server->unix_path);
-		if (server->tcp_nodelay) {
+
-			LOG_ERROR("TCP_NODELAY flag can't be used with UNIX socket and will be ignored");
+#	ifdef WITH_SYSTEMD
+	} else if (server->systemd) {
+		LOG_DEBUG("Binding HTTP to systemd socket ...");
+		if ((RUN(ext_fd) = evhttp_my_bind_systemd(RUN(http))) < 0) {
+			return -1;
 		}
+		LOG_INFO("Listening systemd socket ...");
+#	endif
+
 	} else {
 		LOG_DEBUG("Binding HTTP to [%s]:%u ...", server->host, server->port);
 		if (evhttp_bind_socket(RUN(http), server->host, server->port) < 0) {
@@ -546,7 +553,7 @@ static void _http_callback_stream(struct evhttp_request *request, void *v_server
 			client->hostport, client->id, RUN(stream_clients_count));
 
 		struct bufferevent *buf_event = evhttp_connection_get_bufferevent(conn);
-		if (server->tcp_nodelay && !RUN(unix_fd)) {
+		if (server->tcp_nodelay && !RUN(ext_fd)) {
 			evutil_socket_t fd;
 			int on = 1;
 

src/ustreamer/http/server.h

@@ -71,6 +71,9 @@
 #include "uri.h"
 #include "mime.h"
 #include "static.h"
+#ifdef WITH_SYSTEMD
+#	include "systemd/systemd.h"
+#endif
 
 
 typedef struct stream_client_sx {
@@ -112,7 +115,7 @@ typedef struct {
 typedef struct {
 	struct event_base	*base;
 	struct evhttp		*http;
-	evutil_socket_t		unix_fd;
+	evutil_socket_t		ext_fd; // Unix or socket activation
 	char				*auth_token;
 	struct event		*refresh;
 	stream_s			*stream;
@@ -124,9 +127,15 @@ typedef struct {
 typedef struct server_sx {
 	char		*host;
 	unsigned	port;
+
 	char		*unix_path;
 	bool		unix_rm;
 	mode_t		unix_mode;
+
+#	ifdef WITH_SYSTEMD
+	bool		systemd;
+#	endif
+
 	bool		tcp_nodelay;
 	unsigned	timeout;
 

src/ustreamer/http/systemd/systemd.c

@@ -0,0 +1,46 @@
+/*****************************************************************************
+#                                                                            #
+#    uStreamer - Lightweight and fast MJPEG-HTTP streamer.                   #
+#                                                                            #
+#    Copyright (C) 2018-2022  Maxim Devaev <mdevaev@gmail.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 3 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, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+*****************************************************************************/
+
+
+#include "systemd.h"
+
+
+evutil_socket_t evhttp_my_bind_systemd(struct evhttp *http) {
+	int fds = sd_listen_fds(1);
+	if (fds < 1) {
+		LOG_ERROR("No available systemd sockets");
+		return -1;
+	}
+
+	int fd;
+	for (fd = 1; fd < fds; ++fd) {
+		close(SD_LISTEN_FDS_START + fd);
+	}
+	fd = SD_LISTEN_FDS_START;
+
+	assert(!evutil_make_socket_nonblocking(fd));
+
+	if (evhttp_accept_socket(http, fd) < 0) {
+		LOG_PERROR("Can't evhttp_accept_socket() systemd socket");
+		return -1;
+	}
+	return fd;
+}

src/ustreamer/http/systemd/systemd.h

@@ -0,0 +1,37 @@
+/*****************************************************************************
+#                                                                            #
+#    uStreamer - Lightweight and fast MJPEG-HTTP streamer.                   #
+#                                                                            #
+#    Copyright (C) 2018-2022  Maxim Devaev <mdevaev@gmail.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 3 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, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+*****************************************************************************/
+
+
+#pragma once
+
+#include <unistd.h>
+#include <assert.h>
+
+#include <event2/http.h>
+#include <event2/util.h>
+
+#include <systemd/sd-daemon.h>
+
+#include "../../../libs/tools.h"
+#include "../../../libs/logging.h"
+
+
+evutil_socket_t evhttp_my_bind_systemd(struct evhttp *http);

src/ustreamer/options.c

@@ -50,6 +50,9 @@ enum _OPT_VALUES {
 	_O_UNIX = 'U',
 	_O_UNIX_RM = 'D',
 	_O_UNIX_MODE = 'M',
+#	ifdef WITH_SYSTEMD
+	_O_SYSTEMD = 'S',
+#	endif
 	_O_DROP_SAME_FRAMES = 'e',
 	_O_FAKE_RESOLUTION = 'R',
 
@@ -168,6 +171,9 @@ static const struct option _LONG_OPTS[] = {
 	{"unix",					required_argument,	NULL,	_O_UNIX},
 	{"unix-rm",					no_argument,		NULL,	_O_UNIX_RM},
 	{"unix-mode",				required_argument,	NULL,	_O_UNIX_MODE},
+#	ifdef WITH_SYSTEMD
+	{"systemd",					no_argument,		NULL,	_O_SYSTEMD},
+#	endif
 	{"user",					required_argument,	NULL,	_O_USER},
 	{"passwd",					required_argument,	NULL,	_O_PASSWD},
 	{"static",					required_argument,	NULL,	_O_STATIC},
@@ -419,6 +425,9 @@ int options_parse(options_s *options, device_s *dev, encoder_s *enc, stream_s *s
 			case _O_UNIX:				OPT_SET(server->unix_path, optarg);
 			case _O_UNIX_RM:			OPT_SET(server->unix_rm, true);
 			case _O_UNIX_MODE:			OPT_NUMBER("--unix-mode", server->unix_mode, INT_MIN, INT_MAX, 8);
+#			ifdef WITH_SYSTEMD
+			case _O_SYSTEMD:			OPT_SET(server->systemd, true);
+#			endif
 			case _O_USER:				OPT_SET(server->user, optarg);
 			case _O_PASSWD:				OPT_SET(server->passwd, optarg);
 			case _O_STATIC:				OPT_SET(server->static_path, optarg);
@@ -551,6 +560,12 @@ static void _features(void) {
 	puts("- WITH_GPIO");
 #	endif
 
+#	ifdef WITH_SYSTEMD
+	puts("+ WITH_SYSTEMD");
+#	else
+	puts("- WITH_SYSTEMD");
+#	endif
+
 #	ifdef WITH_PTHREAD_NP
 	puts("+ WITH_PTHREAD_NP");
 #	else
@@ -652,6 +667,9 @@ static void _help(FILE *fp, device_s *dev, encoder_s *enc, stream_s *stream, ser
 	SAY("    -U|--unix <path>  ─────────── Bind to UNIX domain socket. Default: disabled.\n");
 	SAY("    -D|--unix-rm  ─────────────── Try to remove old UNIX socket file before binding. Default: disabled.\n");
 	SAY("    -M|--unix-mode <mode>  ────── Set UNIX socket file permissions (like 777). Default: disabled.\n");
+#	ifdef WITH_SYSTEMD
+	SAY("    -S|--systemd  ─────────────── Bind to systemd socket for socket activation.\n");
+#	endif
 	SAY("    --user <name>  ────────────── HTTP basic auth user. Default: disabled.\n");
 	SAY("    --passwd <str>  ───────────── HTTP basic auth passwd. Default: empty.\n");
 	SAY("    --static <path> ───────────── Path to dir with static files instead of embedded root index page.");
@@ -661,7 +679,7 @@ static void _help(FILE *fp, device_s *dev, encoder_s *enc, stream_s *stream, ser
 	SAY("                                  the CPU loading. Don't use this option with analog signal sources");
 	SAY("                                  or webcams, it's useless. Default: disabled.\n");
 	SAY("    -R|--fake-resolution <WxH>  ─ Override image resolution for the /state. Default: disabled.\n");
-	SAY("    --tcp-nodelay  ────────────── Set TCP_NODELAY flag to the client /stream socket. Ignored for --unix.");
+	SAY("    --tcp-nodelay  ────────────── Set TCP_NODELAY flag to the client /stream socket. Only for TCP socket.");
 	SAY("                                  Default: disabled.\n");
 	SAY("    --allow-origin <str>  ─────── Set Access-Control-Allow-Origin header. Default: disabled.\n");
 	SAY("    --server-timeout <sec>  ───── Timeout for client connections. Default: %u.\n", server->timeout);