Prevent shutdown while running dpkg

As long as we are running dpkg, keep an inhibitor that
blocks us from shutting down.

LP: #1820886

(cherry picked from commit 96aef11a5cf400377a52f7e93e70944b17e249d1)
(cherry picked from commit 8ea79afcadead5a5b7d94bf8623cb833859f6d80)
(cherry picked from commit c5b8a857f2535fe284426cefda2fbd1bbb3d5808)

Also fixup prepare-release for CI to handle [linux-any] build-dep,
and do the whole autoconf / makefile stuff.

10 files changed, 88 insertions, 3 deletions

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 5d283bdf5..f2642e5dc 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -67,6 +67,9 @@
 #ifdef HAVE_LZ4
 	#include <lz4frame.h>
 #endif
+#ifdef HAVE_SYSTEMD
+#include <systemd/sd-bus.h>
+#endif
 #include <endian.h>
 #include <stdint.h>
 
@@ -3029,3 +3032,48 @@ bool DropPrivileges()							/*{{{*/
    return true;
 }
 									/*}}}*/
+int Inhibit(const char *what, const char *who, const char *why, const char *mode) /*{{{*/
+{
+#ifdef HAVE_SYSTEMD
+   sd_bus_error error = SD_BUS_ERROR_NULL;
+   sd_bus_message *m = NULL;
+   sd_bus *bus = NULL;
+   int fd;
+   int r;
+
+   r = sd_bus_open_system(&bus);
+   if (r < 0)
+      goto out;
+
+   r = sd_bus_call_method(bus,
+			  "org.freedesktop.login1",
+			  "/org/freedesktop/login1",
+			  "org.freedesktop.login1.Manager",
+			  "Inhibit",
+			  &error,
+			  &m,
+			  "ssss",
+			  what,
+			  who,
+			  why,
+			  mode);
+   if (r < 0)
+      goto out;
+
+   r = sd_bus_message_read(m, "h", &fd);
+   if (r < 0)
+      goto out;
+
+   // We received a file descriptor, return it - systemd will close the read fd
+   // on free, so let's duplicate it here.
+   r = dup(fd);
+out:
+   sd_bus_error_free(&error);
+   sd_bus_message_unref(m);
+   sd_bus_unref(bus);
+   return r;
+#else
+   return -ENOTSUP;
+#endif
+}
+									/*}}}*/
diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h
index 7ee302d7b..32e5612bf 100644
--- a/apt-pkg/contrib/fileutl.h
+++ b/apt-pkg/contrib/fileutl.h
@@ -253,4 +253,6 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode,
 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode);
 
 
+APT_HIDDEN int Inhibit(const char *what, const char *who, const char *why, const char *mode);
+
 #endif
diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc
index 7a3d1d1f4..05bee9286 100644
--- a/apt-pkg/deb/dpkgpm.cc
+++ b/apt-pkg/deb/dpkgpm.cc
@@ -1232,6 +1232,22 @@ bool pkgDPkgPM::Go(APT::Progress::PackageManager *progress)
       return (I.Pkg->Flags & pkgCache::Flag::Essential) != 0;
    };
 
+   struct Inhibitor
+   {
+      int Fd = -1;
+      Inhibitor()
+      {
+	 if (_config->FindB("DPkg::Inhibit-Shutdown", true))
+	    Fd = Inhibit("shutdown", "APT", "APT is installing or removing packages", "block");
+      }
+      ~Inhibitor()
+      {
+	 if (Fd > 0)
+	    close(Fd);
+      }
+   } inhibitor;
+
+
    pkgPackageManager::SigINTStop = false;
    d->progress = progress;
 
diff --git a/apt-pkg/makefile b/apt-pkg/makefile
index 789d3f2fd..b66e9b272 100644
--- a/apt-pkg/makefile
+++ b/apt-pkg/makefile
@@ -12,7 +12,7 @@ include ../buildlib/defaults.mak
 # The library name and version (indirectly used from init.h)
 include ../buildlib/libversion.mak
 
-CPPFLAGS+=-DAPT_PKG_EXPOSE_STRING_VIEW
+CPPFLAGS+=-DAPT_PKG_EXPOSE_STRING_VIEW $(SYSTEMD_CFLAGS)
 LIBRARY=apt-pkg
 MAJOR=$(LIBAPTPKG_MAJOR)
 MINOR=$(LIBAPTPKG_RELEASE)
@@ -29,6 +29,9 @@ endif
 ifeq ($(HAVE_LZ4),yes)
 SLIBS+= -llz4
 endif
+ifeq ($(HAVE_SYSTEMD),yes)
+SLIBS+= $(SYSTEMD_LIBS)
+endif
 APT_DOMAIN:=libapt-pkg$(LIBAPTPKG_MAJOR)
 
 SOURCE = $(sort $(wildcard *.cc */*.cc))
diff --git a/buildlib/config.h.in b/buildlib/config.h.in
index fb21b387f..3179beb69 100644
--- a/buildlib/config.h.in
+++ b/buildlib/config.h.in
@@ -17,6 +17,9 @@
 /* Define if we have the lz4 library for lz4 */
 #undef HAVE_LZ4
 
+/* Define if we have the systemd library */
+#undef HAVE_SYSTEMD
+
 /* These two are used by the statvfs shim for glibc2.0 and bsd */
 /* Define if we have sys/vfs.h */
 #undef HAVE_VFS_H
diff --git a/buildlib/environment.mak.in b/buildlib/environment.mak.in
index 9620722de..2df4786f9 100644
--- a/buildlib/environment.mak.in
+++ b/buildlib/environment.mak.in
@@ -71,6 +71,9 @@ HAVE_BZ2 = @HAVE_BZ2@
 HAVE_LZMA = @HAVE_LZMA@
 HAVE_LZ4 = @HAVE_LZ4@
 NEED_SOCKLEN_T_DEFINE = @NEED_SOCKLEN_T_DEFINE@
+HAVE_SYSTEMD = @HAVE_SYSTEMD@
+SYSTEMD_CFLAGS = @SYSTEMD_CFLAGS@
+SYSTEMD_LIBS = @SYSTEMD_LIBS@
 
 # Shared library things
 HOST_OS = @host_os@
diff --git a/configure.ac b/configure.ac
index 82b7e73a6..edf98fbeb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -129,6 +129,12 @@ if test "x$HAVE_LZMA" = "xyes"; then
 	AC_DEFINE(HAVE_LZMA)
 fi
 
+HAVE_SYSTEMD=no
+AC_SUBST(HAVE_SYSTEMD)
+PKG_CHECK_MODULES([SYSTEMD], [libsystemd >= 221],
+       [HAVE_SYSTEMD=yes
+	AC_DEFINE(HAVE_SYSTEMD)])
+
 dnl Converts the ARCH to be something singular for this general CPU family
 dnl This is often the dpkg architecture string.
 dnl First check against the full canonical canoncial-system-type in $target
diff --git a/debian/control b/debian/control
index 319aea118..bb8e92520 100644
--- a/debian/control
+++ b/debian/control
@@ -9,7 +9,8 @@ Build-Depends: dpkg-dev (>= 1.17.14), debhelper (>= 9.20141010), libdb-dev,
  gettext (>= 0.12), libcurl4-gnutls-dev (>= 7.19.4~),
  zlib1g-dev, libbz2-dev, liblzma-dev, liblz4-dev (>= 0.0~r126),
  xsltproc, docbook-xsl, docbook-xml, po4a (>= 0.34-2),
- autotools-dev, autoconf, automake, libgtest-dev <!nocheck>, dh-systemd
+ autotools-dev, autoconf, automake, libgtest-dev <!nocheck>, dh-systemd,
+ libsystemd-dev [linux-any], pkg-config
 Build-Depends-Indep: doxygen, w3m, graphviz
 Build-Conflicts: autoconf2.13, automake1.4
 Vcs-Git: git://anonscm.debian.org/apt/apt.git
diff --git a/doc/examples/configure-index b/doc/examples/configure-index
index 8e8110d94..24c5581b4 100644
--- a/doc/examples/configure-index
+++ b/doc/examples/configure-index
@@ -418,6 +418,9 @@ DPkg
    // controls if apt will apport on the first dpkg error or if it 
    // tries to install as many packages as possible
    StopOnError "true";
+
+   // Set a shutdown block inhibitor on systemd systems while running dpkg
+   Inhibit-Shutdown "<BOOL>";
 }
 
 /* Options you can set to see some debugging text They correspond to names
diff --git a/prepare-release b/prepare-release
index 731eb1096..8810dd500 100755
--- a/prepare-release
+++ b/prepare-release
@@ -147,7 +147,7 @@ elif [ "$1" = 'buildlog' ]; then
 		shift
 	done
 elif [ "$1" = 'travis-ci' ]; then
-	apt-get install -qy --no-install-recommends $(sed -n -e '/^Build-Depends: /,/^Build-Depends-Indep: / {p}' debian/control | sed -e 's#([^)]*)##g' -e 's#^Build-Depends\(-Indep\)\?: ##' -e 's#<.*>##g' | tr -d ',')
+	apt-get install -qy --no-install-recommends $(sed -n -e '/^Build-Depends: /,/^Build-Depends-Indep: / {p}' debian/control | sed -e 's#([^)]*)##g' -e 's#\[[^]]*\]##g' -e 's#^Build-Depends\(-Indep\)\?: ##' -e 's#<.*>##g' | tr -d ',')
 	apt-get install -qy --no-install-recommends $(sed -n 's#^Depends: .*@, \(.*\)$#\1#p' debian/tests/control | tr -d ',')
 elif [ "$1" = 'coverage' ]; then
 	DIR="${2:-./coverage}"