[PATCH 1/3] systemd: add systemd-style socket-activation
Lennart Poettering
mzqohf at 0pointer.de
Wed Jun 23 09:10:10 PDT 2010
This is a pretty straightforward implementation of systemd-style socket
activation using the reference implementation of the
$LISTEN_FDS/$LISTEN_PID env var parsing as supplied by systemd upstream.
---
dbus/Makefile.am | 8 +-
dbus/dbus-server-unix.c | 34 ++++-
dbus/dbus-sysdeps-unix.c | 101 +++++++++++
dbus/dbus-sysdeps-unix.h | 3 +
dbus/sd-daemon.c | 448 ++++++++++++++++++++++++++++++++++++++++++++++
dbus/sd-daemon.h | 239 ++++++++++++++++++++++++
6 files changed, 831 insertions(+), 2 deletions(-)
create mode 100644 dbus/sd-daemon.c
create mode 100644 dbus/sd-daemon.h
diff --git a/dbus/Makefile.am b/dbus/Makefile.am
index 906b4c7..f88c7b7 100644
--- a/dbus/Makefile.am
+++ b/dbus/Makefile.am
@@ -88,7 +88,9 @@ DBUS_SHARED_arch_sources = \
dbus-transport-unix.c \
dbus-transport-unix.h \
dbus-userdb.c \
- dbus-userdb.h
+ dbus-userdb.h \
+ sd-daemon.c \
+ sd-daemon.h
DBUS_UTIL_arch_sources = \
dbus-sysdeps-util-unix.c \
@@ -281,3 +283,7 @@ dbus_test_LDFLAGS=@R_DYNAMIC_LDFLAG@
## mop up the gcov files
clean-local:
/bin/rm *.bb *.bbg *.da *.gcov .libs/*.da .libs/*.bbg || true
+
+update-systemd:
+ curl http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c > sd-daemon.c
+ curl http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.h > sd-daemon.h
diff --git a/dbus/dbus-server-unix.c b/dbus/dbus-server-unix.c
index 65c9668..3e5ad6c 100644
--- a/dbus/dbus-server-unix.c
+++ b/dbus/dbus-server-unix.c
@@ -146,6 +146,39 @@ _dbus_server_listen_platform_specific (DBusAddressEntry *entry,
return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
}
}
+ else if (strcmp (method, "systemd") == 0)
+ {
+ int n, *fds;
+ DBusString address;
+
+ n = _dbus_listen_systemd_sockets (&fds, error);
+ if (n < 0)
+ {
+ _DBUS_ASSERT_ERROR_IS_SET (error);
+ return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
+ }
+
+ _dbus_string_init_const (&address, "systemd:");
+
+ *server_p = _dbus_server_new_for_socket (fds, n, &address, NULL);
+ if (*server_p == NULL)
+ {
+ int i;
+
+ for (i = 0; i < n; i++)
+ {
+ _dbus_close_socket (fds[i], NULL);
+ }
+ dbus_free (fds);
+
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
+ }
+
+ dbus_free (fds);
+
+ return DBUS_SERVER_LISTEN_OK;
+ }
else
{
/* If we don't handle the method, we return NULL with the
@@ -233,4 +266,3 @@ _dbus_server_new_for_domain_socket (const char *path,
}
/** @} */
-
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index ebe9bdd..e859ec6 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -76,6 +76,8 @@
#include <bsm/adt.h>
#endif
+#include "sd-daemon.h"
+
#ifndef O_BINARY
#define O_BINARY 0
#endif
@@ -1019,6 +1021,105 @@ _dbus_listen_unix_socket (const char *path,
}
/**
+ * Acquires one or more sockets passed in from systemd. The sockets
+ * are set to be nonblocking.
+ *
+ * This will set FD_CLOEXEC for the sockets returned.
+ *
+ * @oaram fds the file descriptors
+ * @param error return location for errors
+ * @returns the number of file descriptors
+ */
+int
+_dbus_listen_systemd_sockets (int **fds,
+ DBusError *error)
+{
+ int r, n;
+ unsigned fd;
+ int *new_fds;
+
+ _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+ n = sd_listen_fds (TRUE);
+ if (n < 0)
+ {
+ dbus_set_error (error, _dbus_error_from_errno (-n),
+ "Failed to acquire systemd socket: %s",
+ _dbus_strerror (-n));
+ return -1;
+ }
+
+ if (n <= 0)
+ {
+ dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
+ "No socket received.");
+ return -1;
+ }
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++)
+ {
+ r = sd_is_socket (fd, AF_UNSPEC, SOCK_STREAM, 1);
+ if (r < 0)
+ {
+ dbus_set_error (error, _dbus_error_from_errno (-r),
+ "Failed to verify systemd socket type: %s",
+ _dbus_strerror (-r));
+ return -1;
+ }
+
+ if (!r)
+ {
+ dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
+ "Passed socket has wrong type.");
+ return -1;
+ }
+ }
+
+ /* OK, the file descriptors are all good, so let's take posession of
+ them then. */
+
+ new_fds = dbus_new (int, n);
+ if (!new_fds)
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
+ "Failed to allocate file handle array.");
+ goto fail;
+ }
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++)
+ {
+ if (!_dbus_set_local_creds (fd, TRUE))
+ {
+ dbus_set_error (error, _dbus_error_from_errno (errno),
+ "Failed to enable LOCAL_CREDS on systemd socket: %s",
+ _dbus_strerror (errno));
+ goto fail;
+ }
+
+ if (!_dbus_set_fd_nonblocking (fd, error))
+ {
+ _DBUS_ASSERT_ERROR_IS_SET (error);
+ goto fail;
+ }
+
+ new_fds[fd - SD_LISTEN_FDS_START] = fd;
+ }
+
+ *fds = new_fds;
+ return n;
+
+ fail:
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++)
+ {
+ _dbus_close (fd, NULL);
+ }
+
+ dbus_free (new_fds);
+ return -1;
+}
+
+/**
* Creates a socket and connects to a socket at the given host
* and port. The connection fd is returned, and is set up as
* nonblocking.
diff --git a/dbus/dbus-sysdeps-unix.h b/dbus/dbus-sysdeps-unix.h
index 81758e0..807d2cf 100644
--- a/dbus/dbus-sysdeps-unix.h
+++ b/dbus/dbus-sysdeps-unix.h
@@ -72,6 +72,9 @@ int _dbus_listen_unix_socket (const char *path,
dbus_bool_t abstract,
DBusError *error);
+int _dbus_listen_systemd_sockets (int **fd,
+ DBusError *error);
+
dbus_bool_t _dbus_read_credentials (int client_fd,
DBusCredentials *credentials,
DBusError *error);
diff --git a/dbus/sd-daemon.c b/dbus/sd-daemon.c
new file mode 100644
index 0000000..cb568b5
--- /dev/null
+++ b/dbus/sd-daemon.c
@@ -0,0 +1,448 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+ 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.
+***/
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/fcntl.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "sd-daemon.h"
+
+int sd_listen_fds(int unset_environment) {
+
+#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
+ return 0;
+#else
+ int r, fd;
+ const char *e;
+ char *p = NULL;
+ unsigned long l;
+
+ if (!(e = getenv("LISTEN_PID"))) {
+ r = 0;
+ goto finish;
+ }
+
+ errno = 0;
+ l = strtoul(e, &p, 10);
+
+ if (errno != 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (!p || *p || l <= 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ /* Is this for us? */
+ if (getpid() != (pid_t) l) {
+ r = 0;
+ goto finish;
+ }
+
+ if (!(e = getenv("LISTEN_FDS"))) {
+ r = 0;
+ goto finish;
+ }
+
+ errno = 0;
+ l = strtoul(e, &p, 10);
+
+ if (errno != 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (!p || *p) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + (int) l; fd ++) {
+ int flags;
+
+ if ((flags = fcntl(fd, F_GETFD)) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (flags & FD_CLOEXEC)
+ continue;
+
+ if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ r = (int) l;
+
+finish:
+ if (unset_environment) {
+ unsetenv("LISTEN_PID");
+ unsetenv("LISTEN_FDS");
+ }
+
+ return r;
+#endif
+}
+
+int sd_is_fifo(int fd, const char *path) {
+ struct stat st_fd;
+
+ if (fd < 0)
+ return -EINVAL;
+
+ memset(&st_fd, 0, sizeof(st_fd));
+ if (fstat(fd, &st_fd) < 0)
+ return -errno;
+
+ if (!S_ISFIFO(st_fd.st_mode))
+ return 0;
+
+ if (path) {
+ struct stat st_path;
+
+ memset(&st_path, 0, sizeof(st_path));
+ if (fstat(fd, &st_path) < 0) {
+
+ if (errno == ENOENT || errno == ENOTDIR)
+ return 0;
+
+ return -errno;
+ }
+
+ return
+ st_path.st_dev == st_fd.st_dev &&
+ st_path.st_ino == st_fd.st_ino;
+ }
+
+ return 1;
+}
+
+static int sd_is_socket_internal(int fd, int type, int listening) {
+ struct stat st_fd;
+
+ if (fd < 0 || type < 0)
+ return -EINVAL;
+
+ if (fstat(fd, &st_fd) < 0)
+ return -errno;
+
+ if (!S_ISSOCK(st_fd.st_mode))
+ return 0;
+
+ if (type != 0) {
+ int other_type = 0;
+ socklen_t l = sizeof(other_type);
+
+ if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0)
+ return -errno;
+
+ if (l != sizeof(other_type))
+ return -EINVAL;
+
+ if (other_type != type)
+ return 0;
+ }
+
+ if (listening >= 0) {
+ int accepting = 0;
+ socklen_t l = sizeof(accepting);
+
+ if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0)
+ return -errno;
+
+ if (l != sizeof(accepting))
+ return -EINVAL;
+
+ if (!accepting != !listening)
+ return 0;
+ }
+
+ return 1;
+}
+
+union sockaddr_union {
+ struct sockaddr sa;
+ struct sockaddr_in in4;
+ struct sockaddr_in6 in6;
+ struct sockaddr_un un;
+ struct sockaddr_storage storage;
+};
+
+int sd_is_socket(int fd, int family, int type, int listening) {
+ int r;
+
+ if (family < 0)
+ return -EINVAL;
+
+ if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
+ return r;
+
+ if (family > 0) {
+ union sockaddr_union sockaddr;
+ socklen_t l;
+
+ memset(&sockaddr, 0, sizeof(sockaddr));
+ l = sizeof(sockaddr);
+
+ if (getsockname(fd, &sockaddr.sa, &l) < 0)
+ return -errno;
+
+ if (l < sizeof(sa_family_t))
+ return -EINVAL;
+
+ return sockaddr.sa.sa_family == family;
+ }
+
+ return 1;
+}
+
+int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) {
+ union sockaddr_union sockaddr;
+ socklen_t l;
+ int r;
+
+ if (family != 0 && family != AF_INET && family != AF_INET6)
+ return -EINVAL;
+
+ if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
+ return r;
+
+ memset(&sockaddr, 0, sizeof(sockaddr));
+ l = sizeof(sockaddr);
+
+ if (getsockname(fd, &sockaddr.sa, &l) < 0)
+ return -errno;
+
+ if (l < sizeof(sa_family_t))
+ return -EINVAL;
+
+ if (sockaddr.sa.sa_family != AF_INET &&
+ sockaddr.sa.sa_family != AF_INET6)
+ return 0;
+
+ if (family > 0)
+ if (sockaddr.sa.sa_family != family)
+ return 0;
+
+ if (port > 0) {
+ if (sockaddr.sa.sa_family == AF_INET) {
+ if (l < sizeof(struct sockaddr_in))
+ return -EINVAL;
+
+ return htons(port) == sockaddr.in4.sin_port;
+ } else {
+ if (l < sizeof(struct sockaddr_in6))
+ return -EINVAL;
+
+ return htons(port) == sockaddr.in6.sin6_port;
+ }
+ }
+
+ return 1;
+}
+
+int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) {
+ union sockaddr_union sockaddr;
+ socklen_t l;
+ int r;
+
+ if ((r = sd_is_socket_internal(fd, type, listening)) <= 0)
+ return r;
+
+ memset(&sockaddr, 0, sizeof(sockaddr));
+ l = sizeof(sockaddr);
+
+ if (getsockname(fd, &sockaddr.sa, &l) < 0)
+ return -errno;
+
+ if (l < sizeof(sa_family_t))
+ return -EINVAL;
+
+ if (sockaddr.sa.sa_family != AF_UNIX)
+ return 0;
+
+ if (path) {
+ if (length <= 0)
+ length = strlen(path);
+
+ if (length <= 0)
+ /* Unnamed socket */
+ return l == sizeof(sa_family_t);
+
+ if (path[0])
+ /* Normal path socket */
+ return
+ (l >= sizeof(sa_family_t) + length + 1) &&
+ memcmp(path, sockaddr.un.sun_path, length+1) == 0;
+ else
+ /* Abstract namespace socket */
+ return
+ (l == sizeof(sa_family_t) + length) &&
+ memcmp(path, sockaddr.un.sun_path, length) == 0;
+ }
+
+ return 1;
+}
+
+int sd_notify(int unset_environment, const char *state) {
+#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
+ return 0;
+#else
+ int fd = -1, r;
+ struct msghdr msghdr;
+ struct iovec iovec;
+ union sockaddr_union sockaddr;
+ struct ucred *ucred;
+ union {
+ struct cmsghdr cmsghdr;
+ uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+ } control;
+ const char *e;
+
+ if (!state) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if (!(e = getenv("NOTIFY_SOCKET")))
+ return 0;
+
+ /* Must be an abstract socket, or an absolute path */
+ if ((e[0] != '@' && e[0] != '/') || e[1] == 0) {
+ r = -EINVAL;
+ goto finish;
+ }
+
+ if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ memset(&sockaddr, 0, sizeof(sockaddr));
+ sockaddr.sa.sa_family = AF_UNIX;
+ strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path));
+
+ if (sockaddr.un.sun_path[0] == '@')
+ sockaddr.un.sun_path[0] = 0;
+
+ memset(&iovec, 0, sizeof(iovec));
+ iovec.iov_base = (char*) state;
+ iovec.iov_len = strlen(state);
+
+ memset(&control, 0, sizeof(control));
+ control.cmsghdr.cmsg_level = SOL_SOCKET;
+ control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
+ control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));
+
+ ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+ ucred->pid = getpid();
+ ucred->uid = getuid();
+ ucred->gid = getgid();
+
+ memset(&msghdr, 0, sizeof(msghdr));
+ msghdr.msg_name = &sockaddr;
+ msghdr.msg_namelen = sizeof(struct sockaddr_un);
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = control.cmsghdr.cmsg_len;
+
+ if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ r = 1;
+
+finish:
+ if (unset_environment)
+ unsetenv("NOTIFY_SOCKET");
+
+ if (fd >= 0)
+ close(fd);
+
+ return r;
+#endif
+}
+
+int sd_notifyf(int unset_environment, const char *format, ...) {
+#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
+ return 0;
+#else
+ va_list ap;
+ char *p = NULL;
+ int r;
+
+ va_start(ap, format);
+ r = vasprintf(&p, format, ap);
+ va_end(ap);
+
+ if (r < 0 || !p)
+ return -ENOMEM;
+
+ r = sd_notify(unset_environment, p);
+ free(p);
+
+ return r;
+#endif
+}
+
+int sd_booted(void) {
+#if defined(DISABLE_SYSTEMD) || !defined(__linux__)
+ return 0;
+#else
+
+ struct stat a, b;
+
+ /* We simply test whether the systemd cgroup hierarchy is
+ * mounted */
+
+ if (lstat("/cgroup", &a) < 0)
+ return 0;
+
+ if (lstat("/cgroup/systemd", &b) < 0)
+ return 0;
+
+ return a.st_dev != b.st_dev;
+#endif
+}
diff --git a/dbus/sd-daemon.h b/dbus/sd-daemon.h
new file mode 100644
index 0000000..7797047
--- /dev/null
+++ b/dbus/sd-daemon.h
@@ -0,0 +1,239 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#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/plain/src/sd-daemon.h
+ http://cgit.freedesktop.org/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.
+*/
+
+#if __GNUC__ >= 4
+#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b)))
+#define _sd_hidden_ __attribute__ ((visibility("hidden")))
+#else
+#define _sd_printf_attr_(a,b)
+#define _sd_hidden_
+#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.
+*/
+int sd_listen_fds(int unset_environment) _sd_hidden_;
+
+/*
+ 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.
+*/
+int sd_is_fifo(int fd, const char *path) _sd_hidden_;
+
+/*
+ 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.
+*/
+int sd_is_socket(int fd, int family, int type, int listening) _sd_hidden_;
+
+/*
+ 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.
+*/
+int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) _sd_hidden_;
+
+/*
+ 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.
+*/
+int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) _sd_hidden_;
+
+/*
+ Informs systemd about changed daemon state. This takes a number of
+ newline seperated 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 signalling 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"
+
+ Daemons can choose to send additional variables. However, it is
+ recommened 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.
+*/
+int sd_notify(int unset_environment, const char *state) _sd_hidden_;
+
+/*
+ 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);
+*/
+int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3) _sd_hidden_;
+
+/*
+ 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 session and system services.
+*/
+int sd_booted(void) _sd_hidden_;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
--
1.7.0.1
Lennart
--
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
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