From 1db0a48375836c7e93ac30649007c2391be8b3b2 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 4 Jul 2011 01:37:01 +0200 Subject: [PATCH] systemd: add systemd socket activation and unit files On newer Linux machines systemd supports launchd-style socket activation. This patch adds support for this mechanism and also adds systemd unit files as appropriate to hook this up with systemd. This includes an MIT-licensed drop-in file that implements the most basic interfaces needed to get the file descriptors from systemd. Most of the systemd and Linux-specific code compiles to NOPs on other systems. Three triggers to start CUPS are defined: a) if new printer hardware is plugged in, b) when a client accesses the CUPS socket and c) when a spool file resides in /var/spool/cups. --- Makedefs.in | 2 + config-scripts/cups-systemd.m4 | 25 ++ configure.in | 4 + data/Makefile | 9 + data/cups.path.in | 8 + data/cups.service.in | 9 + data/cups.socket.in | 9 + scheduler/Makefile | 9 + scheduler/main.c | 107 ++++++++ scheduler/sd-daemon.c | 520 ++++++++++++++++++++++++++++++++++++++++ scheduler/sd-daemon.h | 277 +++++++++++++++++++++ 11 files changed, 979 insertions(+), 0 deletions(-) create mode 100644 config-scripts/cups-systemd.m4 create mode 100644 data/cups.path.in create mode 100644 data/cups.service.in create mode 100644 data/cups.socket.in create mode 100644 scheduler/sd-daemon.c create mode 100644 scheduler/sd-daemon.h diff --git a/Makedefs.in b/Makedefs.in index 654eea4..02c43b6 100644 --- a/Makedefs.in +++ b/Makedefs.in @@ -143,6 +143,7 @@ CXXFLAGS = @CPPFLAGS@ @CXXFLAGS@ CXXLIBS = @CXXLIBS@ DBUS_NOTIFIER = @DBUS_NOTIFIER@ DBUS_NOTIFIERLIBS = @DBUS_NOTIFIERLIBS@ +SYSTEMD_UNITS = @SYSTEMD_UNITS@ DNSSD_BACKEND = @DNSSD_BACKEND@ DSOFLAGS = -L../cups @DSOFLAGS@ DSOLIBS = @DSOLIBS@ $(COMMONLIBS) @@ -267,6 +268,7 @@ PAMFILE = @PAMFILE@ DEFAULT_LAUNCHD_CONF = @DEFAULT_LAUNCHD_CONF@ DBUSDIR = @DBUSDIR@ +SYSTEMDUNITDIR = $(BUILDROOT)@systemdsystemunitdir@ # diff --git a/config-scripts/cups-systemd.m4 b/config-scripts/cups-systemd.m4 new file mode 100644 index 0000000..fead8a9 --- /dev/null +++ b/config-scripts/cups-systemd.m4 @@ -0,0 +1,25 @@ +dnl +dnl "$Id$" +dnl +dnl systemd stuff for CUPS. + +dnl Find whether systemd is available + +AC_ARG_WITH([systemdsystemunitdir], + AS_HELP_STRING([--with-systemdsystemunitdir=DIR], [Directory for systemd service files]), + [], [with_systemdsystemunitdir=$($PKGCONFIG --variable=systemdsystemunitdir systemd)]) +if test "x$with_systemdsystemunitdir" != xno; then + AC_SUBST([systemdsystemunitdir], [$with_systemdsystemunitdir]) +fi + +if test -n "$with_systemdsystemunitdir" -a "x$with_systemdsystemunitdir" != xno ; then + SYSTEMD_UNITS="cups.service cups.socket cups.path" +else + SYSTEMD_UNITS="" +fi + +AC_SUBST(SYSTEMD_UNITS) + +dnl +dnl "$Id$" +dnl diff --git a/configure.in b/configure.in index 560f4f8..b0c19a9 100644 --- a/configure.in +++ b/configure.in @@ -37,6 +37,7 @@ sinclude(config-scripts/cups-pam.m4) sinclude(config-scripts/cups-largefile.m4) sinclude(config-scripts/cups-dnssd.m4) sinclude(config-scripts/cups-launchd.m4) +sinclude(config-scripts/cups-systemd.m4) sinclude(config-scripts/cups-defaults.m4) sinclude(config-scripts/cups-pdf.m4) sinclude(config-scripts/cups-scripting.m4) @@ -71,6 +72,9 @@ AC_OUTPUT(Makedefs conf/snmp.conf cups-config data/testprint + data/cups.service + data/cups.socket + data/cups.path desktop/cups.desktop doc/help/ref-cupsd-conf.html doc/help/standard.html diff --git a/data/Makefile b/data/Makefile index b9de21a..cccab85 100644 --- a/data/Makefile +++ b/data/Makefile @@ -112,6 +112,12 @@ install-data: $(INSTALL_DATA) $$file $(DATADIR)/ppdc; \ done $(INSTALL_DIR) -m 755 $(DATADIR)/profiles + if test "x$(SYSTEMD_UNITS)" != "x" ; then \ + $(INSTALL_DIR) -m 755 $(SYSTEMDUNITDIR); \ + for file in $(SYSTEMD_UNITS); do \ + $(INSTALL_DATA) $$file $(SYSTEMDUNITDIR); \ + done; \ + fi # @@ -159,6 +165,9 @@ uninstall: -$(RMDIR) $(DATADIR)/charsets -$(RMDIR) $(DATADIR)/banners -$(RMDIR) $(DATADIR) + for file in $(SYSTEMD_UNITS); do \ + $(RM) $(SYSTEMDUNITDIR)/$$file; \ + done # diff --git a/data/cups.path.in b/data/cups.path.in new file mode 100644 index 0000000..c99e39b --- /dev/null +++ b/data/cups.path.in @@ -0,0 +1,8 @@ +[Unit] +Description=CUPS Printer Service Spool + +[Path] +DirectoryNotEmpty=@CUPS_REQUESTS@ + +[Install] +WantedBy=multi-user.target diff --git a/data/cups.service.in b/data/cups.service.in new file mode 100644 index 0000000..007d0e6 --- /dev/null +++ b/data/cups.service.in @@ -0,0 +1,9 @@ +[Unit] +Description=CUPS Printing Service + +[Service] +ExecStart=@sbindir@/cupsd -f + +[Install] +Also=cups.socket cups.path +WantedBy=printer.target diff --git a/data/cups.socket.in b/data/cups.socket.in new file mode 100644 index 0000000..b940096 --- /dev/null +++ b/data/cups.socket.in @@ -0,0 +1,9 @@ +[Unit] +Description=CUPS Printing Service Sockets + +[Socket] +ListenStream=@CUPS_DEFAULT_DOMAINSOCKET@ +ListenStream=631 + +[Install] +WantedBy=sockets.target diff --git a/scheduler/Makefile b/scheduler/Makefile index 3c7da8e..05152a6 100644 --- a/scheduler/Makefile +++ b/scheduler/Makefile @@ -39,6 +39,7 @@ CUPSDOBJS = \ server.o \ statbuf.o \ subscriptions.o \ + sd-daemon.o \ sysman.o LIBOBJS = \ filter.o \ @@ -568,6 +569,14 @@ sloc: # +# Update sd-daemon.[ch] drop-in file from upstream git +# + +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 + +# # Dependencies... # diff --git a/scheduler/main.c b/scheduler/main.c index baaa3a1..5a4b8e1 100644 --- a/scheduler/main.c +++ b/scheduler/main.c @@ -26,6 +26,8 @@ * launchd_checkin() - Check-in with launchd and collect the listening * fds. * launchd_checkout() - Update the launchd KeepAlive file as needed. + * systemd_checkin() - Check-in with systemd and collect the + * listening fds. * parent_handler() - Catch USR1/CHLD signals... * process_children() - Process all dead children... * select_timeout() - Calculate the select timeout value. @@ -62,6 +64,8 @@ # endif /* !LAUNCH_JOBKEY_SERVICEIPC */ #endif /* HAVE_LAUNCH_H */ +#include "sd-daemon.h" + #if defined(HAVE_MALLOC_H) && defined(HAVE_MALLINFO) # include #endif /* HAVE_MALLOC_H && HAVE_MALLINFO */ @@ -78,6 +82,7 @@ static void launchd_checkin(void); static void launchd_checkout(void); #endif /* HAVE_LAUNCHD */ +static void systemd_checkin(void); static void parent_handler(int sig); static void process_children(void); static void sigchld_handler(int sig); @@ -520,6 +525,11 @@ main(int argc, /* I - Number of command-line args */ #endif /* HAVE_LAUNCHD */ /* + * If we were started by systemd get the listen sockets file descriptors... + */ + systemd_checkin(); + + /* * Startup the server... */ @@ -731,6 +741,12 @@ main(int argc, /* I - Number of command-line args */ #endif /* HAVE_LAUNCHD */ /* + * If we were started by systemd get the listen sockets file descriptors... + */ + + systemd_checkin(); + + /* * Startup the server... */ @@ -1535,6 +1551,97 @@ launchd_checkout(void) } #endif /* HAVE_LAUNCHD */ +static void +systemd_checkin(void) +{ + int n, fd; + + n = sd_listen_fds(1); + if (n < 0) + { + cupsdLogMessage(CUPSD_LOG_ERROR, + "systemd_checkin: Failed to acquire sockets from systemd - %s", + strerror(-n)); + exit(EXIT_FAILURE); + return; + } + + if (n == 0) + return; + + for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++) + { + http_addr_t addr; + socklen_t addrlen; + int r; + cupsd_listener_t *lis; + char s[256]; + + r = sd_is_socket(fd, AF_UNSPEC, SOCK_STREAM, 1); + if (r < 0) { + cupsdLogMessage(CUPSD_LOG_ERROR, + "systemd_checkin: Unable to verify socket type - %s", + strerror(-r)); + continue; + } + + if (!r) { + cupsdLogMessage(CUPSD_LOG_ERROR, + "systemd_checkin: Socket not of the right type"); + continue; + } + + if (getsockname(fd, (struct sockaddr*) &addr, &addrlen)) + { + cupsdLogMessage(CUPSD_LOG_ERROR, + "systemd_checkin: Unable to get local address - %s", + strerror(errno)); + continue; + } + + /* + * Try to match the systemd socket address to one of the listeners... + */ + + for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners); + lis; + lis = (cupsd_listener_t *)cupsArrayNext(Listeners)) + if (httpAddrEqual(&lis->address, &addr)) + break; + + if (lis) + { + cupsdLogMessage(CUPSD_LOG_DEBUG, + "systemd_checkin: Matched existing listener %s with fd %d...", + httpAddrString(&(lis->address), s, sizeof(s)), fd); + } + else + { + cupsdLogMessage(CUPSD_LOG_DEBUG, + "systemd_checkin: Adding new listener %s with fd %d...", + httpAddrString(&addr, s, sizeof(s)), fd); + + if ((lis = calloc(1, sizeof(cupsd_listener_t))) == NULL) + { + cupsdLogMessage(CUPSD_LOG_ERROR, + "systemd_checkin: Unable to allocate listener - " + "%s.", strerror(errno)); + exit(EXIT_FAILURE); + } + + cupsArrayAdd(Listeners, lis); + + memcpy(&lis->address, &addr, sizeof(lis->address)); + } + + lis->fd = fd; + +# ifdef HAVE_SSL + if (_httpAddrPort(&(lis->address)) == 443) + lis->encryption = HTTP_ENCRYPT_ALWAYS; +# endif /* HAVE_SSL */ + } +} /* * 'parent_handler()' - Catch USR1/CHLD signals... diff --git a/scheduler/sd-daemon.c b/scheduler/sd-daemon.c new file mode 100644 index 0000000..a2ec74c --- /dev/null +++ b/scheduler/sd-daemon.c @@ -0,0 +1,520 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if defined(__linux__) +#include +#endif + +#include "sd-daemon.h" + +#if (__GNUC__ >= 4) && !defined(SD_EXPORT_SYMBOLS) +#define _sd_hidden_ __attribute__ ((visibility("hidden"))) +#else +#define _sd_hidden_ +#endif + +_sd_hidden_ 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 +} + +_sd_hidden_ 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 (stat(path, &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; +} + +_sd_hidden_ int sd_is_special(int fd, const char *path) { + struct stat st_fd; + + if (fd < 0) + return -EINVAL; + + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISREG(st_fd.st_mode) && !S_ISCHR(st_fd.st_mode)) + return 0; + + if (path) { + struct stat st_path; + + if (stat(path, &st_path) < 0) { + + if (errno == ENOENT || errno == ENOTDIR) + return 0; + + return -errno; + } + + if (S_ISREG(st_fd.st_mode) && S_ISREG(st_path.st_mode)) + return + st_path.st_dev == st_fd.st_dev && + st_path.st_ino == st_fd.st_ino; + else if (S_ISCHR(st_fd.st_mode) && S_ISCHR(st_path.st_mode)) + return st_path.st_rdev == st_fd.st_rdev; + else + return 0; + } + + 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; +}; + +_sd_hidden_ 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; +} + +_sd_hidden_ 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; +} + +_sd_hidden_ 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 == offsetof(struct sockaddr_un, sun_path); + + if (path[0]) + /* Normal path socket */ + return + (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) && + memcmp(path, sockaddr.un.sun_path, length+1) == 0; + else + /* Abstract namespace socket */ + return + (l == offsetof(struct sockaddr_un, sun_path) + length) && + memcmp(path, sockaddr.un.sun_path, length) == 0; + } + + return 1; +} + +_sd_hidden_ int sd_is_mq(int fd, const char *path) { +#if !defined(__linux__) + return 0; +#else + struct mq_attr attr; + + if (fd < 0) + return -EINVAL; + + if (mq_getattr(fd, &attr) < 0) + return -errno; + + if (path) { + char fpath[PATH_MAX]; + struct stat a, b; + + if (path[0] != '/') + return -EINVAL; + + if (fstat(fd, &a) < 0) + return -errno; + + strncpy(stpcpy(fpath, "/dev/mqueue"), path, sizeof(fpath) - 12); + fpath[sizeof(fpath)-1] = 0; + + if (stat(fpath, &b) < 0) + return -errno; + + if (a.st_dev != b.st_dev || + a.st_ino != b.st_ino) + return 0; + } + + return 1; +#endif +} + +_sd_hidden_ int sd_notify(int unset_environment, const char *state) { +#if defined(DISABLE_SYSTEMD) || !defined(__linux__) || !defined(SOCK_CLOEXEC) + return 0; +#else + int fd = -1, r; + struct msghdr msghdr; + struct iovec iovec; + union sockaddr_union sockaddr; + 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(&msghdr, 0, sizeof(msghdr)); + msghdr.msg_name = &sockaddr; + msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(e); + + if (msghdr.msg_namelen > sizeof(struct sockaddr_un)) + msghdr.msg_namelen = sizeof(struct sockaddr_un); + + msghdr.msg_iov = &iovec; + msghdr.msg_iovlen = 1; + + 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 +} + +_sd_hidden_ 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 +} + +_sd_hidden_ 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("/sys/fs/cgroup", &a) < 0) + return 0; + + if (lstat("/sys/fs/cgroup/systemd", &b) < 0) + return 0; + + return a.st_dev != b.st_dev; +#endif +} diff --git a/scheduler/sd-daemon.h b/scheduler/sd-daemon.h new file mode 100644 index 0000000..46dc7fd --- /dev/null +++ b/scheduler/sd-daemon.h @@ -0,0 +1,277 @@ +/*-*- 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 +#include + +#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. + + 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" + + 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 -- 1.7.6