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https://github.com/AuxXxilium/eudev.git
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sd-daemon: introduce sd_booted() and set ELF visibility to hidden for all symbols
This commit is contained in:
Lennart Poettering
parent
f1c5860be7
commit
40473a70cf
@ -38,6 +38,8 @@
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#define _weak_ __attribute__ ((weak))
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#define _likely_(x) (__builtin_expect(!!(x),1))
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#define _unlikely_(x) (__builtin_expect(!!(x),0))
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#define _public_ __attribute__ ((visibility("default")))
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#define _hidden_ __attribute__ ((visibility("hidden")))
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/* Rounds up */
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static inline size_t ALIGN(size_t l) {
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@ -426,3 +426,23 @@ int sd_notifyf(int unset_environment, const char *format, ...) {
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return r;
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#endif
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}
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int sd_booted(void) {
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#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
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return 0;
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#else
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struct stat a, b;
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/* We simply test whether the systemd cgroup hierarchy is
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* mounted */
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if (lstat("/cgroup", &a) < 0)
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return 0;
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if (lstat("/cgroup/systemd", &b) < 0)
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return 0;
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return a.st_dev != b.st_dev;
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#endif
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}
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277
src/sd-daemon.h
277
src/sd-daemon.h
@ -34,17 +34,43 @@
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extern "C" {
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#endif
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/* Reference implementation of a few systemd related interfaces for
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* writing daemons. These interfaces are trivial to implement. To
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* simplify porting we provide this reference
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* implementation. Applications are welcome to reimplement the
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* algorithms described here, if they do not want to include these two
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* source files. */
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/*
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Reference implementation of a few systemd related interfaces for
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writing daemons. These interfaces are trivial to implement. To
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simplify porting we provide this reference implementation.
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Applications are welcome to reimplement the algorithms described
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here if they do not want to include these two source files.
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#ifdef __GNUC__
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The following functionality is provided:
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- Support for logging with log levels on stderr
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- File descriptor passing for socket-based activation
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- Daemon startup and status notification
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- Detection of systemd boots
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You may compile this with -DDISABLE_SYSTEMD to disable systemd
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support. This make all those calls NOPs that are directly related to
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systemd (i.e. only sd_is_xxx() will stay useful).
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Since this is drop-in code we don't want any of our symbols to be
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exported in any case. Hence we declare hidden visibility for all of
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them.
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You may find an up-to-date version of these source files online:
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http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.h
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http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c
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This should compile on non-Linux systems, too, but with the
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exception of the sd_is_xxx() calls all functions will become NOPs.
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*/
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#if __GNUC__ >= 4
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#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
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#define _sd_hidden_ __attribute__ ((visibility("hidden")))
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#else
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#define _sd_printf_attr_(a,b)
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#define _sd_hidden_
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#endif
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/*
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@ -54,7 +80,6 @@ extern "C" {
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This is similar to printk() usage in the kernel.
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*/
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#define SD_EMERG "<0>" /* system is unusable */
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#define SD_ALERT "<1>" /* action must be taken immediately */
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#define SD_CRIT "<2>" /* critical conditions */
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@ -67,116 +92,144 @@ extern "C" {
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/* The first passed file descriptor is fd 3 */
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#define SD_LISTEN_FDS_START 3
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/* Returns how many file descriptors have been passed, or a negative
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* errno code on failure. Optionally, removes the $LISTEN_FDS and
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* $LISTEN_PID file descriptors from the environment (recommended, but
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* problematic in threaded environments). If r is the return value of
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* this function you'll find the file descriptors passed as fds
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* SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative
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* errno style error code on failure. This function call ensures that
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* the FD_CLOEXEC flag is set for the passed file descriptors, to make
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* sure they are not passed on to child processes. If FD_CLOEXEC shall
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* not be set, the caller needs to unset it after this call for all file
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* descriptors that are used.*/
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int sd_listen_fds(int unset_environment);
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/*
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Returns how many file descriptors have been passed, or a negative
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errno code on failure. Optionally, removes the $LISTEN_FDS and
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$LISTEN_PID file descriptors from the environment (recommended, but
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problematic in threaded environments). If r is the return value of
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this function you'll find the file descriptors passed as fds
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SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative
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errno style error code on failure. This function call ensures that
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the FD_CLOEXEC flag is set for the passed file descriptors, to make
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sure they are not passed on to child processes. If FD_CLOEXEC shall
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not be set, the caller needs to unset it after this call for all file
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descriptors that are used.
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*/
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int sd_listen_fds(int unset_environment) _sd_hidden_;
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/* Helper call for identifying a passed file descriptor. Returns 1 if
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* the file descriptor is a FIFO in the file system stored under the
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* specified path, 0 otherwise. If path is NULL a path name check will
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* not be done and the call only verifies if the file descriptor
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* refers to a FIFO. Returns a negative errno style error code on
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* failure. */
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int sd_is_fifo(int fd, const char *path);
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/*
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Helper call for identifying a passed file descriptor. Returns 1 if
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the file descriptor is a FIFO in the file system stored under the
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specified path, 0 otherwise. If path is NULL a path name check will
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not be done and the call only verifies if the file descriptor
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refers to a FIFO. Returns a negative errno style error code on
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failure.
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*/
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int sd_is_fifo(int fd, const char *path) _sd_hidden_;
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/* Helper call for identifying a passed file descriptor. Returns 1 if
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* the file descriptor is a socket of the specified family (AF_INET,
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* ...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If
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* family is 0 a socket family check will not be done. If type is 0 a
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* socket type check will not be done and the call only verifies if
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* the file descriptor refers to a socket. If listening is > 0 it is
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* verified that the socket is in listening mode. (i.e. listen() has
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* been called) If listening is == 0 it is verified that the socket is
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* not in listening mode. If listening is < 0 no listening mode check
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* is done. Returns a negative errno style error code on failure. */
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int sd_is_socket(int fd, int family, int type, int listening);
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/*
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Helper call for identifying a passed file descriptor. Returns 1 if
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the file descriptor is a socket of the specified family (AF_INET,
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...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If
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family is 0 a socket family check will not be done. If type is 0 a
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socket type check will not be done and the call only verifies if
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the file descriptor refers to a socket. If listening is > 0 it is
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verified that the socket is in listening mode. (i.e. listen() has
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been called) If listening is == 0 it is verified that the socket is
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not in listening mode. If listening is < 0 no listening mode check
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is done. Returns a negative errno style error code on failure.
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*/
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int sd_is_socket(int fd, int family, int type, int listening) _sd_hidden_;
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/* Helper call for identifying a passed file descriptor. Returns 1 if
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* the file descriptor is an Internet socket, of the specified family
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* (either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM,
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* SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version
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* check is not done. If type is 0 a socket type check will not be
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* done. If port is 0 a socket port check will not be done. The
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* listening flag is used the same way as in sd_is_socket(). Returns a
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* negative errno style error code on failure. */
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int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port);
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/*
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Helper call for identifying a passed file descriptor. Returns 1 if
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the file descriptor is an Internet socket, of the specified family
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(either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM,
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SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version
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check is not done. If type is 0 a socket type check will not be
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done. If port is 0 a socket port check will not be done. The
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listening flag is used the same way as in sd_is_socket(). Returns a
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negative errno style error code on failure.
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*/
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int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) _sd_hidden_;
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/* Helper call for identifying a passed file descriptor. Returns 1 if
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* the file descriptor is an AF_UNIX socket of the specified type
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* (SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0
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* a socket type check will not be done. If path is NULL a socket path
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* check will not be done. For normal AF_UNIX sockets set length to
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* 0. For abstract namespace sockets set length to the length of the
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* socket name (including the initial 0 byte), and pass the full
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* socket path in path (including the initial 0 byte). The listening
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* flag is used the same way as in sd_is_socket(). Returns a negative
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* errno style error code on failure. */
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int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length);
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/*
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Helper call for identifying a passed file descriptor. Returns 1 if
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the file descriptor is an AF_UNIX socket of the specified type
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(SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0
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a socket type check will not be done. If path is NULL a socket path
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check will not be done. For normal AF_UNIX sockets set length to
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0. For abstract namespace sockets set length to the length of the
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socket name (including the initial 0 byte), and pass the full
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socket path in path (including the initial 0 byte). The listening
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flag is used the same way as in sd_is_socket(). Returns a negative
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errno style error code on failure.
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*/
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int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) _sd_hidden_;
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/* Informs systemd about changed daemon state. This takes a numeber of
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* newline seperated environment-style variable assignments in a
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* string. The following strings are known:
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*
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* READY=1 Tells systemd that daemon startup is finished (only
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* relevant for services of Type=notify). The passed
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* argument is a boolean "1" or "0". Since there is
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* little value in signalling non-readiness the only
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* value daemons should send is "READY=1".
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*
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* STATUS=... Passes a single-line status string back to systemd
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* that describes the daemon state. This is free-from
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* and can be used for various purposes: general state
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* feedback, fsck-like programs could pass completion
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* percentages and failing programs could pass a human
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* readable error message. Example: "STATUS=Completed
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* 66% of file system check..."
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*
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* ERRNO=... If a daemon fails, the errno-style error code,
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* formatted as string. Example: "ERRNO=2" for ENOENT.
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*
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* BUSERROR=... If a daemon fails, the D-Bus error-style error
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* code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
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*
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* MAINPID=... The main pid of a daemon, in case systemd did not
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* fork off the process itself. Example: "MAINPID=4711"
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*
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* Daemons can choose to send additional variables.
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*
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* Returns a negative errno-style error code on failure. Returns > 0
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* if systemd could be notified, 0 if it couldn't possibly because
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* systemd is not running.
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*
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* See sd_notifyf() for more complete examples.
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*/
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int sd_notify(int unset_environment, const char *state);
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/*
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Informs systemd about changed daemon state. This takes a numeber of
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newline seperated environment-style variable assignments in a
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string. The following strings are known:
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/* Similar to sd_send_state() but takes a format string.
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*
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* Example 1: A daemon could send the following after initialization:
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*
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* sd_notifyf(0, "READY=1\n"
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* "STATUS=Processing requests...\n"
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* "MAINPID=%lu",
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* (unsigned long) getpid());
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*
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* Example 2: A daemon could send the following shortly before
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* exiting, on failure:
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*
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* sd_notifyf(0, "STATUS=Failed to start up: %s\n"
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* "ERRNO=%i",
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* strerror(errno),
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* errno);
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*/
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int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3);
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READY=1 Tells systemd that daemon startup is finished (only
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relevant for services of Type=notify). The passed
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argument is a boolean "1" or "0". Since there is
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little value in signalling non-readiness the only
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value daemons should send is "READY=1".
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STATUS=... Passes a single-line status string back to systemd
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that describes the daemon state. This is free-from
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and can be used for various purposes: general state
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feedback, fsck-like programs could pass completion
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percentages and failing programs could pass a human
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readable error message. Example: "STATUS=Completed
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66% of file system check..."
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ERRNO=... If a daemon fails, the errno-style error code,
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formatted as string. Example: "ERRNO=2" for ENOENT.
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BUSERROR=... If a daemon fails, the D-Bus error-style error
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code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut"
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MAINPID=... The main pid of a daemon, in case systemd did not
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fork off the process itself. Example: "MAINPID=4711"
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Daemons can choose to send additional variables.
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Returns a negative errno-style error code on failure. Returns > 0
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if systemd could be notified, 0 if it couldn't possibly because
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systemd is not running.
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Example: When a daemon finished starting up, it could issue this
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call to notify systemd about it:
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sd_notify(0, "READY=1");
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See sd_notifyf() for more complete examples.
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*/
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int sd_notify(int unset_environment, const char *state) _sd_hidden_;
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/*
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Similar to sd_notify() but takes a format string.
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Example 1: A daemon could send the following after initialization:
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sd_notifyf(0, "READY=1\n"
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"STATUS=Processing requests...\n"
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"MAINPID=%lu",
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(unsigned long) getpid());
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Example 2: A daemon could send the following shortly before
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exiting, on failure:
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sd_notifyf(0, "STATUS=Failed to start up: %s\n"
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"ERRNO=%i",
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strerror(errno),
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errno);
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*/
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int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3) _sd_hidden_;
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/*
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Returns > 0 if the system was booted with systemd. Returns < 0 on
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error. Returns 0 if the system was not booted with systemd. Note
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that all of the functions above handle non-systemd boots just
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fine. You should NOT protect them with a call to this function. Also
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note that this function checks whether the system, not the user
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session is controlled by systemd. However the functions above work
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for both session and system services.
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*/
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int sd_booted(void) _sd_hidden_;
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#ifdef __cplusplus
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}
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