src/systemd/sd-daemon.h - systemd-stable - Rivoreo Source Code Repositories

 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

 #ifndef foosddaemonhfoo
 #define foosddaemonhfoo

 /***
   Copyright 2010 Lennart Poettering

   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.
 ***/

 #include <sys/types.h>
 #include <inttypes.h>

 #ifdef __cplusplus
 extern "C" {
 #endif

 /*
   Reference implementation of a few systemd related interfaces for
   writing daemons. These interfaces are trivial to implement. To
   simplify porting we provide this reference implementation.
   Applications are welcome to reimplement the algorithms described
   here if they do not want to include these two source files.

   The following functionality is provided:

   - Support for logging with log levels on stderr
   - File descriptor passing for socket-based activation
   - Daemon startup and status notification
   - Detection of systemd boots

   You may compile this with -DDISABLE_SYSTEMD to disable systemd
   support. This makes all those calls NOPs that are directly related to
   systemd (i.e. only sd_is_xxx() will stay useful).

   Since this is drop-in code we don't want any of our symbols to be
   exported in any case. Hence we declare hidden visibility for all of
   them.

   You may find an up-to-date version of these source files online:

   http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-daemon.h
   http://cgit.freedesktop.org/systemd/systemd/plain/src/sd-daemon.c

   This should compile on non-Linux systems, too, but with the
   exception of the sd_is_xxx() calls all functions will become NOPs.

   See sd-daemon(7) for more information.
 */

 #ifndef _sd_printf_attr_
 #if __GNUC__ >= 4
 #define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
 #else
 #define _sd_printf_attr_(a,b)
 #endif
 #endif

 /*
   Log levels for usage on stderr:

           fprintf(stderr, SD_NOTICE "Hello World!\n");

   This is similar to printk() usage in the kernel.
 */
 #define SD_EMERG   "<0>"  /* system is unusable */
 #define SD_ALERT   "<1>"  /* action must be taken immediately */
 #define SD_CRIT    "<2>"  /* critical conditions */
 #define SD_ERR     "<3>"  /* error conditions */
 #define SD_WARNING "<4>"  /* warning conditions */
 #define SD_NOTICE  "<5>"  /* normal but significant condition */
 #define SD_INFO    "<6>"  /* informational */
 #define SD_DEBUG   "<7>"  /* debug-level messages */

 /* The first passed file descriptor is fd 3 */
 #define SD_LISTEN_FDS_START 3

 /*
   Returns how many file descriptors have been passed, or a negative
   errno code on failure. Optionally, removes the $LISTEN_FDS and
   $LISTEN_PID file descriptors from the environment (recommended, but
   problematic in threaded environments). If r is the return value of
   this function you'll find the file descriptors passed as fds
   SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative
   errno style error code on failure. This function call ensures that
   the FD_CLOEXEC flag is set for the passed file descriptors, to make
   sure they are not passed on to child processes. If FD_CLOEXEC shall
   not be set, the caller needs to unset it after this call for all file
   descriptors that are used.

   See sd_listen_fds(3) for more information.
 */
 int sd_listen_fds(int unset_environment);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is a FIFO in the file system stored under the
   specified path, 0 otherwise. If path is NULL a path name check will
   not be done and the call only verifies if the file descriptor
   refers to a FIFO. Returns a negative errno style error code on
   failure.

   See sd_is_fifo(3) for more information.
 */
 int sd_is_fifo(int fd, const char *path);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is a special character device on the file
   system stored under the specified path, 0 otherwise.
   If path is NULL a path name check will not be done and the call
   only verifies if the file descriptor refers to a special character.
   Returns a negative errno style error code on failure.

   See sd_is_special(3) for more information.
 */
 int sd_is_special(int fd, const char *path);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is a socket of the specified family (AF_INET,
   ...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If
   family is 0 a socket family check will not be done. If type is 0 a
   socket type check will not be done and the call only verifies if
   the file descriptor refers to a socket. If listening is > 0 it is
   verified that the socket is in listening mode. (i.e. listen() has
   been called) If listening is == 0 it is verified that the socket is
   not in listening mode. If listening is < 0 no listening mode check
   is done. Returns a negative errno style error code on failure.

   See sd_is_socket(3) for more information.
 */
 int sd_is_socket(int fd, int family, int type, int listening);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is an Internet socket, of the specified family
   (either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM,
   SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version
   check is not done. If type is 0 a socket type check will not be
   done. If port is 0 a socket port check will not be done. The
   listening flag is used the same way as in sd_is_socket(). Returns a
   negative errno style error code on failure.

   See sd_is_socket_inet(3) for more information.
 */
 int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is an AF_UNIX socket of the specified type
   (SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0
   a socket type check will not be done. If path is NULL a socket path
   check will not be done. For normal AF_UNIX sockets set length to
   0. For abstract namespace sockets set length to the length of the
   socket name (including the initial 0 byte), and pass the full
   socket path in path (including the initial 0 byte). The listening
   flag is used the same way as in sd_is_socket(). Returns a negative
   errno style error code on failure.

   See sd_is_socket_unix(3) for more information.
 */
 int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length);

 /*
   Helper call for identifying a passed file descriptor. Returns 1 if
   the file descriptor is a POSIX Message Queue of the specified name,
   0 otherwise. If path is NULL a message queue name check is not
   done. Returns a negative errno style error code on failure.
 */
 int sd_is_mq(int fd, const char *path);

 /*
   Informs systemd about changed daemon state. This takes a number of
   newline separated environment-style variable assignments in a
   string. The following variables are known:

      READY=1      Tells systemd that daemon startup is finished (only
                   relevant for services of Type=notify). The passed
                   argument is a boolean "1" or "0". Since there is
                   little value in signaling non-readiness the only
                   value daemons should send is "READY=1".

      STATUS=...   Passes a single-line status string back to systemd
                   that describes the daemon state. This is free-from
                   and can be used for various purposes: general state
                   feedback, fsck-like programs could pass completion
                   percentages and failing programs could pass a human
                   readable error message. Example: "STATUS=Completed
                   66% of file system check..."

      ERRNO=...    If a daemon fails, the errno-style error code,
                   formatted as string. Example: "ERRNO=2" for ENOENT.

      BUSERROR=... If a daemon fails, the D-Bus error-style error
                   code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"

      MAINPID=...  The main pid of a daemon, in case systemd did not
                   fork off the process itself. Example: "MAINPID=4711"

      WATCHDOG=1   Tells systemd to update the watchdog timestamp.
                   Services using this feature should do this in
                   regular intervals. A watchdog framework can use the
                   timestamps to detect failed services.

   Daemons can choose to send additional variables. However, it is
   recommended to prefix variable names not listed above with X_.

   Returns a negative errno-style error code on failure. Returns > 0
   if systemd could be notified, 0 if it couldn't possibly because
   systemd is not running.

   Example: When a daemon finished starting up, it could issue this
   call to notify systemd about it:

      sd_notify(0, "READY=1");

   See sd_notifyf() for more complete examples.

   See sd_notify(3) for more information.
 */
 int sd_notify(int unset_environment, const char *state);

 /*
   Similar to sd_notify() but takes a format string.

   Example 1: A daemon could send the following after initialization:

      sd_notifyf(0, "READY=1\n"
                    "STATUS=Processing requests...\n"
                    "MAINPID=%lu",
                    (unsigned long) getpid());

   Example 2: A daemon could send the following shortly before
   exiting, on failure:

      sd_notifyf(0, "STATUS=Failed to start up: %s\n"
                    "ERRNO=%i",
                    strerror(errno),
                    errno);

   See sd_notifyf(3) for more information.
 */
 int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3);

 /*
   Returns > 0 if the system was booted with systemd. Returns < 0 on
   error. Returns 0 if the system was not booted with systemd. Note
   that all of the functions above handle non-systemd boots just
   fine. You should NOT protect them with a call to this function. Also
   note that this function checks whether the system, not the user
   session is controlled by systemd. However the functions above work
   for both user and system services.

   See sd_booted(3) for more information.
 */
 int sd_booted(void);

 #ifdef __cplusplus
 }
 #endif

 #endif
	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/

	#ifndef foosddaemonhfoo
	#define foosddaemonhfoo

	/***
	Copyright 2010 Lennart Poettering

	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.
	***/

	#include <sys/types.h>
	#include <inttypes.h>

	#ifdef __cplusplus
	extern "C" {
	#endif

	/*
	Reference implementation of a few systemd related interfaces for
	writing daemons. These interfaces are trivial to implement. To
	simplify porting we provide this reference implementation.
	Applications are welcome to reimplement the algorithms described
	here if they do not want to include these two source files.

	The following functionality is provided:

	- Support for logging with log levels on stderr
	- File descriptor passing for socket-based activation
	- Daemon startup and status notification
	- Detection of systemd boots

	You may compile this with -DDISABLE_SYSTEMD to disable systemd
	support. This makes all those calls NOPs that are directly related to
	systemd (i.e. only sd_is_xxx() will stay useful).

	Since this is drop-in code we don't want any of our symbols to be
	exported in any case. Hence we declare hidden visibility for all of
	them.

	You may find an up-to-date version of these source files online:

	http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-daemon.h
	http://cgit.freedesktop.org/systemd/systemd/plain/src/sd-daemon.c

	This should compile on non-Linux systems, too, but with the
	exception of the sd_is_xxx() calls all functions will become NOPs.

	See sd-daemon(7) for more information.
	*/

	#ifndef _sd_printf_attr_
	#if __GNUC__ >= 4
	#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
	#else
	#define _sd_printf_attr_(a,b)
	#endif
	#endif

	/*
	Log levels for usage on stderr:

	fprintf(stderr, SD_NOTICE "Hello World!\n");

	This is similar to printk() usage in the kernel.
	*/
	#define SD_EMERG "<0>" /* system is unusable */
	#define SD_ALERT "<1>" /* action must be taken immediately */
	#define SD_CRIT "<2>" /* critical conditions */
	#define SD_ERR "<3>" /* error conditions */
	#define SD_WARNING "<4>" /* warning conditions */
	#define SD_NOTICE "<5>" /* normal but significant condition */
	#define SD_INFO "<6>" /* informational */
	#define SD_DEBUG "<7>" /* debug-level messages */

	/* The first passed file descriptor is fd 3 */
	#define SD_LISTEN_FDS_START 3

	/*
	Returns how many file descriptors have been passed, or a negative
	errno code on failure. Optionally, removes the $LISTEN_FDS and
	$LISTEN_PID file descriptors from the environment (recommended, but
	problematic in threaded environments). If r is the return value of
	this function you'll find the file descriptors passed as fds
	SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative
	errno style error code on failure. This function call ensures that
	the FD_CLOEXEC flag is set for the passed file descriptors, to make
	sure they are not passed on to child processes. If FD_CLOEXEC shall
	not be set, the caller needs to unset it after this call for all file
	descriptors that are used.

	See sd_listen_fds(3) for more information.
	*/
	int sd_listen_fds(int unset_environment);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is a FIFO in the file system stored under the
	specified path, 0 otherwise. If path is NULL a path name check will
	not be done and the call only verifies if the file descriptor
	refers to a FIFO. Returns a negative errno style error code on
	failure.

	See sd_is_fifo(3) for more information.
	*/
	int sd_is_fifo(int fd, const char *path);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is a special character device on the file
	system stored under the specified path, 0 otherwise.
	If path is NULL a path name check will not be done and the call
	only verifies if the file descriptor refers to a special character.
	Returns a negative errno style error code on failure.

	See sd_is_special(3) for more information.
	*/
	int sd_is_special(int fd, const char *path);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is a socket of the specified family (AF_INET,
	...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If
	family is 0 a socket family check will not be done. If type is 0 a
	socket type check will not be done and the call only verifies if
	the file descriptor refers to a socket. If listening is > 0 it is
	verified that the socket is in listening mode. (i.e. listen() has
	been called) If listening is == 0 it is verified that the socket is
	not in listening mode. If listening is < 0 no listening mode check
	is done. Returns a negative errno style error code on failure.

	See sd_is_socket(3) for more information.
	*/
	int sd_is_socket(int fd, int family, int type, int listening);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is an Internet socket, of the specified family
	(either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM,
	SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version
	check is not done. If type is 0 a socket type check will not be
	done. If port is 0 a socket port check will not be done. The
	listening flag is used the same way as in sd_is_socket(). Returns a
	negative errno style error code on failure.

	See sd_is_socket_inet(3) for more information.
	*/
	int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is an AF_UNIX socket of the specified type
	(SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0
	a socket type check will not be done. If path is NULL a socket path
	check will not be done. For normal AF_UNIX sockets set length to
	0. For abstract namespace sockets set length to the length of the
	socket name (including the initial 0 byte), and pass the full
	socket path in path (including the initial 0 byte). The listening
	flag is used the same way as in sd_is_socket(). Returns a negative
	errno style error code on failure.

	See sd_is_socket_unix(3) for more information.
	*/
	int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length);

	/*
	Helper call for identifying a passed file descriptor. Returns 1 if
	the file descriptor is a POSIX Message Queue of the specified name,
	0 otherwise. If path is NULL a message queue name check is not
	done. Returns a negative errno style error code on failure.
	*/
	int sd_is_mq(int fd, const char *path);

	/*
	Informs systemd about changed daemon state. This takes a number of
	newline separated environment-style variable assignments in a
	string. The following variables are known:

	READY=1 Tells systemd that daemon startup is finished (only
	relevant for services of Type=notify). The passed
	argument is a boolean "1" or "0". Since there is
	little value in signaling non-readiness the only
	value daemons should send is "READY=1".

	STATUS=... Passes a single-line status string back to systemd
	that describes the daemon state. This is free-from
	and can be used for various purposes: general state
	feedback, fsck-like programs could pass completion
	percentages and failing programs could pass a human
	readable error message. Example: "STATUS=Completed
	66% of file system check..."

	ERRNO=... If a daemon fails, the errno-style error code,
	formatted as string. Example: "ERRNO=2" for ENOENT.

	BUSERROR=... If a daemon fails, the D-Bus error-style error
	code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"

	MAINPID=... The main pid of a daemon, in case systemd did not
	fork off the process itself. Example: "MAINPID=4711"

	WATCHDOG=1 Tells systemd to update the watchdog timestamp.
	Services using this feature should do this in
	regular intervals. A watchdog framework can use the
	timestamps to detect failed services.

	Daemons can choose to send additional variables. However, it is
	recommended to prefix variable names not listed above with X_.

	Returns a negative errno-style error code on failure. Returns > 0
	if systemd could be notified, 0 if it couldn't possibly because
	systemd is not running.

	Example: When a daemon finished starting up, it could issue this
	call to notify systemd about it:

	sd_notify(0, "READY=1");

	See sd_notifyf() for more complete examples.

	See sd_notify(3) for more information.
	*/
	int sd_notify(int unset_environment, const char *state);

	/*
	Similar to sd_notify() but takes a format string.

	Example 1: A daemon could send the following after initialization:

	sd_notifyf(0, "READY=1\n"
	"STATUS=Processing requests...\n"
	"MAINPID=%lu",
	(unsigned long) getpid());

	Example 2: A daemon could send the following shortly before
	exiting, on failure:

	sd_notifyf(0, "STATUS=Failed to start up: %s\n"
	"ERRNO=%i",
	strerror(errno),
	errno);

	See sd_notifyf(3) for more information.
	*/
	int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3);

	/*
	Returns > 0 if the system was booted with systemd. Returns < 0 on
	error. Returns 0 if the system was not booted with systemd. Note
	that all of the functions above handle non-systemd boots just
	fine. You should NOT protect them with a call to this function. Also
	note that this function checks whether the system, not the user
	session is controlled by systemd. However the functions above work
	for both user and system services.

	See sd_booted(3) for more information.
	*/
	int sd_booted(void);

	#ifdef __cplusplus
	}
	#endif

	#endif