Split DBUS_SESSION_BUS_DEFAULT_ADDRESS into listen, connect addresses and set better defaults

On Unix, the connect address should basically always be "autolaunch:"
but the listen address has to be something you can listen on.

On Windows, you can listen on "autolaunch:" or
"autolaunch:scope=*install-path", for instance, and the dbus-daemon is
involved in the auto-launching process.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=38201
Reviewed-by: David Zeuthen <davidz@redhat.com>
[default address changed to autolaunch: for interop with GDBus -smcv]
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>

8 files changed, 76 insertions, 24 deletions

diff --git a/README.cmake b/README.cmake
index 0e923356..0c30ba66 100644
--- a/README.cmake
+++ b/README.cmake
@@ -129,8 +129,11 @@ DBUS_HAVE_ATOMIC_INT:BOOL=OFF
 // install required system libraries
 DBUS_INSTALL_SYSTEM_LIBS:BOOL=OFF
 
-// session bus default address
-DBUS_SESSION_BUS_DEFAULT_ADDRESS:STRING=nonce-tcp:
+// session bus default listening address
+DBUS_SESSION_BUS_LISTEN_ADDRESS:STRING=autolaunch:
+
+// session bus fallback address for clients
+DBUS_SESSION_BUS_CONNECT_ADDRESS:STRING=autolaunch:
 
 // system bus default address (only useful on Unix)
 DBUS_SYSTEM_BUS_DEFAULT_ADDRESS:STRING=unix:path=/var/run/dbus/system_bus_socket
diff --git a/bus/session.conf.in b/bus/session.conf.in
index e121ff93..716b5e79 100644
--- a/bus/session.conf.in
+++ b/bus/session.conf.in
@@ -12,7 +12,7 @@
        the behavior of child processes. -->
   <keep_umask/>
 
-  <listen>@DBUS_SESSION_BUS_DEFAULT_ADDRESS@</listen>
+  <listen>@DBUS_SESSION_BUS_LISTEN_ADDRESS@</listen>
 
   <standard_session_servicedirs />
 
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 5174469d..52a48fdc 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -442,14 +442,16 @@ set (DBUS_USER )
 set (DBUS_SYSTEM_BUS_DEFAULT_ADDRESS "unix:path=${EXPANDED_LOCALSTATEDIR}/run/dbus/system_bus_socket" CACHE STRING "system bus default address")
 
 if (WIN32)
-  set (DBUS_SESSION_BUS_DEFAULT_ADDRESS "nonce-tcp:" CACHE STRING "session bus default address")
+  set (DBUS_SESSION_BUS_LISTEN_ADDRESS "autolaunch:" CACHE STRING "session bus default listening address")
+  set (DBUS_SESSION_BUS_CONNECT_ADDRESS "autolaunch:" CACHE STRING "session bus fallback address for clients")
 
   set (DBUS_SYSTEM_CONFIG_FILE "etc/dbus-1/system.conf")
   set (DBUS_SESSION_CONFIG_FILE "etc/dbus-1/session.conf")
   # bus-test expects a non empty string
   set (DBUS_USER "Administrator")
 else (WIN32)
-  set (DBUS_SESSION_BUS_DEFAULT_ADDRESS "unix:path=${DBUS_SESSION_SOCKET_DIR}" CACHE STRING "session bus default address")
+  set (DBUS_SESSION_BUS_LISTEN_ADDRESS "unix:tmpdir=${DBUS_SESSION_SOCKET_DIR}" CACHE STRING "session bus default listening address")
+  set (DBUS_SESSION_BUS_CONNECT_ADDRESS "autolaunch:" CACHE STRING "session bus fallback address for clients")
   set (sysconfdir "")
   set (configdir ${sysconfdir}/dbus-1 )
   set (DBUS_SYSTEM_CONFIG_FILE  ${configdir}/system.conf)
@@ -569,7 +571,8 @@ message("        Using XML parser:         ${XML_LIB}                          "
 message("        Daemon executable name:   ${DBUS_DAEMON_NAME}")
 if (WIN32)
 message("        System bus address:       ${DBUS_SYSTEM_BUS_DEFAULT_ADDRESS}  ")
-message("        Session bus address:      ${DBUS_SESSION_BUS_DEFAULT_ADDRESS} ")
+message("        Session bus listens on:   ${DBUS_SESSION_BUS_LISTEN_ADDRESS} ")
+message("        Session clients connect to: ${DBUS_SESSION_BUS_CONNECT_ADDRESS} ")
 else (WIN32)
 #message("        Init scripts style:       ${with_init_scripts}                ")
 #message("        Abstract socket names:    ${have_abstract_sockets}            ")
diff --git a/cmake/config.h.cmake b/cmake/config.h.cmake
index 6221c190..76ccb866 100644
--- a/cmake/config.h.cmake
+++ b/cmake/config.h.cmake
@@ -15,8 +15,8 @@
 #cmakedefine DBUS_SESSION_CONFIG_FILE "@DBUS_SESSION_CONFIG_FILE@"
 #cmakedefine DBUS_DAEMON_NAME "@DBUS_DAEMON_NAME@"
 #cmakedefine DBUS_SYSTEM_BUS_DEFAULT_ADDRESS  "@DBUS_SYSTEM_BUS_DEFAULT_ADDRESS@"
+#cmakedefine DBUS_SESSION_BUS_CONNECT_ADDRESS  "@DBUS_SESSION_BUS_CONNECT_ADDRESS@"
 #cmakedefine DBUS_MACHINE_UUID_FILE "@DBUS_MACHINE_UUID_FILE@"
-#cmakedefine DBUS_SESSION_BUS_DEFAULT_ADDRESS "@DBUS_SESSION_BUS_DEFAULT_ADDRESS@"
 #cmakedefine DBUS_DAEMONDIR "@DBUS_DAEMONDIR@"
 #cmakedefine PACKAGE "@PACKAGE@"
 /* Version number of package */
diff --git a/cmake/dbus-env.bat.cmake b/cmake/dbus-env.bat.cmake
index 85f70051..d859ce03 100644
--- a/cmake/dbus-env.bat.cmake
+++ b/cmake/dbus-env.bat.cmake
@@ -2,7 +2,7 @@
 @echo off
 
 :: session bus address
-set DBUS_SESSION_BUS_ADDRESS=@DBUS_SESSION_BUS_DEFAULT_ADDRESS@
+set DBUS_SESSION_BUS_ADDRESS=@DBUS_SESSION_BUS_CONNECT_ADDRESS@
 
 :: system bus address
-set DBUS_SYSTEM_BUS_DEFAULT_ADDRESS=@DBUS_SYSTEM_BUS_DEFAULT_ADDRESS@ 
\ No newline at end of file
+set DBUS_SYSTEM_BUS_DEFAULT_ADDRESS=@DBUS_SYSTEM_BUS_DEFAULT_ADDRESS@
diff --git a/configure.ac b/configure.ac
index 12847c4a..b54d29d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -169,7 +169,6 @@ AC_ARG_WITH(console-owner-file, AS_HELP_STRING([--with-console-owner-file=[filen
 AC_ARG_WITH(launchd-agent-dir, AS_HELP_STRING([--with-launchd-agent-dir=[dirname]],[directory to put the launchd agent (default: /Library/LaunchAgents)]))
 AC_ARG_WITH(dbus_user, AS_HELP_STRING([--with-dbus-user=<user>],[User for running the DBUS daemon (messagebus)]))
 AC_ARG_WITH(dbus_daemondir, AS_HELP_STRING([--with-dbus-daemondir=[dirname]],[Directory for installing the DBUS daemon]))
-AC_ARG_WITH(dbus_session_bus_default_address, AS_HELP_STRING([--with-dbus-session-bus-default-address=[nonce-tcp:/autolaunch:/tcp:host:port]],[Transport Type to be used (default: nonce-tcp:)]),with_dbus_session_bus_default_address=$withval,with_dbus_session_bus_default_address=nonce-tcp:)
 
 AC_ARG_ENABLE([embedded-tests],
   AS_HELP_STRING([--enable-embedded-tests],
@@ -1675,14 +1674,64 @@ fi
 AC_DEFINE_UNQUOTED(DBUS_SESSION_SOCKET_DIR, "$DBUS_SESSION_SOCKET_DIR", [Where per-session bus puts its sockets])
 AC_SUBST(DBUS_SESSION_SOCKET_DIR)
 
-if test x$dbus_win = xyes; then
-        DBUS_SESSION_BUS_DEFAULT_ADDRESS="$with_dbus_session_bus_default_address"
+# This must be a listening address. It doesn't necessarily need to be an
+# address you can connect to - it can be something vague like
+# "nonce-tcp:".
+#
+# The default varies by platform.
+AC_ARG_WITH([dbus_session_bus_listen_address],
+            AS_HELP_STRING([--with-dbus-session-bus-listen-address=[ADDRESS]],
+                           [default address for a session bus to listen on (see configure.ac)]),
+            [with_dbus_session_bus_listen_address=$withval],
+            [with_dbus_session_bus_listen_address=])
+
+if test "x$with_dbus_session_bus_listen_address" != "x"; then
+        # the user specified something, trust them
+        DBUS_SESSION_BUS_LISTEN_ADDRESS="$with_dbus_session_bus_listen_address"
+elif test x$dbus_win = xyes; then
+        # On Windows, you can (and should) listen on autolaunch addresses,
+        # because autolaunching is different.
+        # See https://bugs.freedesktop.org/show_bug.cgi?id=38201
+        DBUS_SESSION_BUS_LISTEN_ADDRESS="autolaunch:"
 elif test x$have_launchd = xyes; then
-        DBUS_SESSION_BUS_DEFAULT_ADDRESS="launchd:env=DBUS_LAUNCHD_SESSION_BUS_SOCKET"
+        # Mac OS X default is to use launchd
+        DBUS_SESSION_BUS_LISTEN_ADDRESS="launchd:env=DBUS_LAUNCHD_SESSION_BUS_SOCKET"
+else
+        # The default on all other Unix platforms (notably Linux)
+        # is to create a randomly named socket in /tmp or similar
+        DBUS_SESSION_BUS_LISTEN_ADDRESS="unix:tmpdir=$DBUS_SESSION_SOCKET_DIR"
+fi
+AC_SUBST([DBUS_SESSION_BUS_LISTEN_ADDRESS])
+
+# This must be an address you can connect to. It doesn't necessarily
+# need to be an address you can listen on - it can be "autolaunch:",
+# even on Unix.
+#
+# The default varies by platform.
+AC_ARG_WITH([dbus_session_bus_connect_address],
+            AS_HELP_STRING([--with-dbus-session-bus-connect-address=[ADDRESS]],
+                           [fallback address for a session bus client to connect to (see configure.ac)]),
+            [with_dbus_session_bus_connect_address=$withval],
+            [with_dbus_session_bus_connect_address=])
+
+if test "x$with_dbus_session_bus_connect_address" != "x"; then
+        # the user specified something, trust them
+        DBUS_SESSION_BUS_CONNECT_ADDRESS="$with_dbus_session_bus_connect_address"
+elif test x$dbus_win = xyes; then
+        # Windows autolaunching is a bit different; leaving it in its own
+        # branch of the conditional because the default might conceivably
+        # change (see #38201)
+        DBUS_SESSION_BUS_CONNECT_ADDRESS="autolaunch:"
 else
-        DBUS_SESSION_BUS_DEFAULT_ADDRESS="unix:tmpdir=$DBUS_SESSION_SOCKET_DIR"
+        # The default on all other Unix platforms (notably Linux)
+        # is to use auto-launching - this works a bit differently on Mac OS X
+        # but comes out basically the same in the end
+        DBUS_SESSION_BUS_CONNECT_ADDRESS="autolaunch:"
 fi
-AC_SUBST(DBUS_SESSION_BUS_DEFAULT_ADDRESS)
+AC_SUBST([DBUS_SESSION_BUS_CONNECT_ADDRESS])
+AC_DEFINE_UNQUOTED([DBUS_SESSION_BUS_CONNECT_ADDRESS],
+  ["$DBUS_SESSION_BUS_CONNECT_ADDRESS"],
+  [Fallback address for session bus clients])
 
 # darwin needs this to initialize the environment
 AC_CHECK_HEADERS(crt_externs.h)
@@ -1798,7 +1847,8 @@ echo "
         System bus socket:        ${DBUS_SYSTEM_SOCKET}
         System bus address:       ${DBUS_SYSTEM_BUS_DEFAULT_ADDRESS}
         System bus PID file:      ${DBUS_SYSTEM_PID_FILE}
-        Session bus address:      ${DBUS_SESSION_BUS_DEFAULT_ADDRESS}
+        Session bus listens on:   ${DBUS_SESSION_BUS_LISTEN_ADDRESS}
+        Session clients connect to: ${DBUS_SESSION_BUS_CONNECT_ADDRESS}
         Console auth dir:         ${DBUS_CONSOLE_AUTH_DIR}
         Console owner file:       ${have_console_owner_file}
         Console owner file path:  ${DBUS_CONSOLE_OWNER_FILE}
diff --git a/dbus/dbus-bus.c b/dbus/dbus-bus.c
index fadc3a8b..6f81c74a 100644
--- a/dbus/dbus-bus.c
+++ b/dbus/dbus-bus.c
@@ -192,12 +192,12 @@ init_session_address (void)
   if (!retval)
     return FALSE;
 
-  /* The DBUS_SESSION_BUS_DEFAULT_ADDRESS should have really been named
-   * DBUS_SESSION_BUS_FALLBACK_ADDRESS. 
-   */
+  /* We have a hard-coded (but compile-time-configurable) fallback address for
+   * the session bus. */
   if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
     bus_connection_addresses[DBUS_BUS_SESSION] =
-      _dbus_strdup (DBUS_SESSION_BUS_DEFAULT_ADDRESS);
+      _dbus_strdup (DBUS_SESSION_BUS_CONNECT_ADDRESS);
+
   if (bus_connection_addresses[DBUS_BUS_SESSION] == NULL)
     return FALSE;
 
diff --git a/dbus/dbus-internals.h b/dbus/dbus-internals.h
index 8036a2ba..80376ad5 100644
--- a/dbus/dbus-internals.h
+++ b/dbus/dbus-internals.h
@@ -35,10 +35,6 @@
 
 DBUS_BEGIN_DECLS
 
-#ifndef DBUS_SESSION_BUS_DEFAULT_ADDRESS
-#define DBUS_SESSION_BUS_DEFAULT_ADDRESS	"autolaunch:"
-#endif
-
 void _dbus_warn               (const char *format,
                                ...) _DBUS_GNUC_PRINTF (1, 2);