From c0bc172383c2c955394589e5808457935ae06f1d Mon Sep 17 00:00:00 2001

From: "Daniel P. Berrange" <berrange@redhat.com>

Date: Mon, 6 Jun 2016 15:03:27 +0100

Subject: [PATCH] systemd: directly notify systemd instead of using sd_notify

The sd_notify method is used to tell systemd when libvirtd

has finished starting up. All it does is send a datagram

containing the string parameter to systemd on a UNIX socket

named in the NOTIFY_SOCKET environment variable. Rather than

pulling in the systemd libraries for this, just code the

notification directly in libvirt as this is a stable ABI

from systemd's POV which explicitly allows independant

implementations:

See "Reimplementable Independently" column in the

"$NOTIFY_SOCKET Daemon Notifications" row:

https://www.freedesktop.org/wiki/Software/systemd/InterfacePortabilityAndStabilityChart/

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1314881

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

---

 configure.ac              |  2 --

 libvirt.spec.in           | 12 -----------

 m4/virt-systemd-daemon.m4 | 34 ------------------------------

 src/Makefile.am           |  4 ++--

 src/util/virsystemd.c     | 53 ++++++++++++++++++++++++++++++++++++++++++-----

 5 files changed, 50 insertions(+), 55 deletions(-)

 delete mode 100644 m4/virt-systemd-daemon.m4

diff --git a/configure.ac b/configure.ac

index f2554a4..12eb3b3 100644

--- a/configure.ac

+++ b/configure.ac

@@ -256,7 +256,6 @@ LIBVIRT_CHECK_SANLOCK

 LIBVIRT_CHECK_SASL

 LIBVIRT_CHECK_SELINUX

 LIBVIRT_CHECK_SSH2

-LIBVIRT_CHECK_SYSTEMD_DAEMON

 LIBVIRT_CHECK_UDEV

 LIBVIRT_CHECK_WIRESHARK

 LIBVIRT_CHECK_NSS

@@ -2787,7 +2786,6 @@ LIBVIRT_RESULT_SANLOCK

 LIBVIRT_RESULT_SASL

 LIBVIRT_RESULT_SELINUX

 LIBVIRT_RESULT_SSH2

-LIBVIRT_RESULT_SYSTEMD_DAEMON

 LIBVIRT_RESULT_UDEV

 LIBVIRT_RESULT_WIRESHARK

 LIBVIRT_RESULT_NSS

diff --git a/libvirt.spec.in b/libvirt.spec.in

index 8b88eef..b93a53c 100644

--- a/libvirt.spec.in

+++ b/libvirt.spec.in

@@ -79,7 +79,6 @@

 %define with_firewalld     0%{!?_without_firewalld:0}

 %define with_libssh2       0%{!?_without_libssh2:0}

 %define with_wireshark     0%{!?_without_wireshark:0}

-%define with_systemd_daemon 0%{!?_without_systemd_daemon:0}

 %define with_pm_utils      1

 # Finally set the OS / architecture specific special cases

@@ -133,7 +132,6 @@

 # Fedora has systemd, libvirt still used sysvinit there.

 %if 0%{?fedora} || 0%{?rhel} >= 7

     %define with_systemd 1

-    %define with_systemd_daemon 1

     %define with_pm_utils 0

 %endif

@@ -268,9 +266,6 @@ BuildRequires: python

 %if %{with_systemd}

 BuildRequires: systemd-units

 %endif

-%if %{with_systemd_daemon}

-BuildRequires: systemd-devel

-%endif

 %if %{with_xen} || %{with_libxl}

 BuildRequires: xen-devel

 %endif

@@ -1061,12 +1056,6 @@ rm -rf .git

     %define arg_wireshark --without-wireshark-dissector

 %endif

-%if %{with_systemd_daemon}

-    %define arg_systemd_daemon --with-systemd-daemon

-%else

-    %define arg_systemd_daemon --without-systemd-daemon

-%endif

-

 %if %{with_pm_utils}

     %define arg_pm_utils --with-pm-utils

 %else

@@ -1157,7 +1146,6 @@ rm -f po/stamp-po

            --with-driver-modules \

            %{?arg_firewalld} \

            %{?arg_wireshark} \

-           %{?arg_systemd_daemon} \

            %{?arg_pm_utils} \

            --with-nss-plugin \

            %{arg_packager} \

diff --git a/m4/virt-systemd-daemon.m4 b/m4/virt-systemd-daemon.m4

deleted file mode 100644

index 8516e41..0000000

--- a/m4/virt-systemd-daemon.m4

+++ /dev/null

@@ -1,34 +0,0 @@

-dnl The libsystemd-daemon.so library

-dnl

-dnl Copyright (C) 2012-2013 Red Hat, Inc.

-dnl

-dnl This library is free software; you can redistribute it and/or

-dnl modify it under the terms of the GNU Lesser General Public

-dnl License as published by the Free Software Foundation; either

-dnl version 2.1 of the License, or (at your option) any later version.

-dnl

-dnl This library is distributed in the hope that it will be useful,

-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of

-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

-dnl Lesser General Public License for more details.

-dnl

-dnl You should have received a copy of the GNU Lesser General Public

-dnl License along with this library.  If not, see

-dnl <http://www.gnu.org/licenses/>.

-dnl

-

-AC_DEFUN([LIBVIRT_CHECK_SYSTEMD_DAEMON],[

-  LIBVIRT_CHECK_PKG([SYSTEMD_DAEMON], [libsystemd-daemon], [0.27.1])

-

-    old_CFLAGS="$CFLAGS"

-    old_LIBS="$LIBS"

-    CFLAGS="$CFLAGS $SYSTEMD_DAEMON_CFLAGS"

-    LIBS="$LIBS $SYSTEMD_DAEMON_LIBS"

-    AC_CHECK_FUNCS([sd_notify])

-    CFLAGS="$old_CFLAGS"

-    LIBS="$old_LIBS"

-])

-

-AC_DEFUN([LIBVIRT_RESULT_SYSTEMD_DAEMON],[

-  LIBVIRT_RESULT_LIB([SYSTEMD_DAEMON])

-])

diff --git a/src/Makefile.am b/src/Makefile.am

index f3c9a14..f020b92 100644

--- a/src/Makefile.am

+++ b/src/Makefile.am

@@ -1107,12 +1107,12 @@ libvirt_util_la_SOURCES =					\

 libvirt_util_la_CFLAGS = $(CAPNG_CFLAGS) $(YAJL_CFLAGS) $(LIBNL_CFLAGS) \

 		$(AM_CFLAGS) $(AUDIT_CFLAGS) $(DEVMAPPER_CFLAGS) \

 		$(DBUS_CFLAGS) $(LDEXP_LIBM) $(NUMACTL_CFLAGS)	\

-		$(SYSTEMD_DAEMON_CFLAGS) $(POLKIT_CFLAGS) $(GNUTLS_CFLAGS) \

+		$(POLKIT_CFLAGS) $(GNUTLS_CFLAGS) \

 		-I$(srcdir)/conf

 libvirt_util_la_LIBADD = $(CAPNG_LIBS) $(YAJL_LIBS) $(LIBNL_LIBS) \

 		$(THREAD_LIBS) $(AUDIT_LIBS) $(DEVMAPPER_LIBS) \

 		$(LIB_CLOCK_GETTIME) $(DBUS_LIBS) $(MSCOM_LIBS) $(LIBXML_LIBS) \

-		$(SECDRIVER_LIBS) $(NUMACTL_LIBS) $(SYSTEMD_DAEMON_LIBS) \

+		$(SECDRIVER_LIBS) $(NUMACTL_LIBS) \

 		$(POLKIT_LIBS)

diff --git a/src/util/virsystemd.c b/src/util/virsystemd.c

index 4883f94..871db7e 100644

--- a/src/util/virsystemd.c

+++ b/src/util/virsystemd.c

@@ -21,8 +21,9 @@

 #include <config.h>

-#ifdef WITH_SYSTEMD_DAEMON

-# include <systemd/sd-daemon.h>

+#include <sys/socket.h>

+#ifdef HAVE_SYS_UN_H

+# include <sys/un.h>

 #endif

 #include "virsystemd.h"

@@ -34,6 +35,7 @@

 #include "virutil.h"

 #include "virlog.h"

 #include "virerror.h"

+#include "virfile.h"

 #define VIR_FROM_THIS VIR_FROM_SYSTEMD

@@ -480,9 +482,50 @@ int virSystemdTerminateMachine(const char *name)

 void

 virSystemdNotifyStartup(void)

 {

-#ifdef WITH_SYSTEMD_DAEMON

-    sd_notify(0, "READY=1");

-#endif

+#ifdef HAVE_SYS_UN_H

+    const char *path;

+    const char *msg = "READY=1";

+    int fd;

+    struct sockaddr_un un = {

+        .sun_family = AF_UNIX,

+    };

+    struct iovec iov = {

+        .iov_base = (char *)msg,

+        .iov_len = strlen(msg),

+    };

+    struct msghdr mh = {

+        .msg_name = &un,

+        .msg_namelen = sizeof(un),

+        .msg_iov = &iov,

+        .msg_iovlen = 1,

+    };

+

+    if (!(path = virGetEnvBlockSUID("NOTIFY_SOCKET"))) {

+        VIR_DEBUG("Skipping systemd notify, not requested");

+        return;

+    }

+

+    /* NB sun_path field is *not* NUL-terminated, hence >, not >= */

+    if (strlen(path) > sizeof(un.sun_path)) {

+        VIR_WARN("Systemd notify socket path '%s' too long", path);

+        return;

+    }

+

+    memcpy(un.sun_path, path, strlen(path));

+    if (un.sun_path[0] == '@')

+        un.sun_path[0] = '\0';

+

+    fd = socket(AF_UNIX, SOCK_DGRAM, 0);

+    if (fd < 0) {

+        VIR_WARN("Unable to create socket FD");

+        return;

+    }

+

+    if (sendmsg(fd, &mh, MSG_NOSIGNAL) < 0)

+        VIR_WARN("Failed to notify systemd");

+

+    VIR_FORCE_CLOSE(fd);

+#endif /* HAVE_SYS_UN_H */

 }

 static int

-- 

2.5.5