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author | Simon McVittie <smcv@collabora.com> | 2022-05-18 16:13:36 +0100 |
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committer | Simon McVittie <smcv@collabora.com> | 2022-10-11 17:14:11 +0100 |
commit | e5d8d0c19ad932dad44b3302c90ba692d3a9017a (patch) | |
tree | 5d0301595d4387629842f14d1d01d2831b98ca39 /tools | |
parent | ba6fb129bdb57320f84032e02f34a98d433caf14 (diff) | |
download | dbus-e5d8d0c19ad932dad44b3302c90ba692d3a9017a.tar.gz |
build: Show a warning if the system bus socket is not interoperable
We would like to start using ${runstatedir}/dbus/system_bus_socket,
so that distributors who make /var/run a symbolic link to /run will
usually get their dbus-daemon listening on /run/dbus/system_bus_socket,
which has some advantages in corner cases, such as when /var is mediated
by an automounter or is unmounted during system shutdown.
Unfortunately, the interoperable path in the D-Bus Specification is
/var/run/dbus/system_bus_socket for historical reasons (D-Bus is older
than /run), and older versions of Slackware are known to have had /run
and /var/run as distinct directories. Do a check during configuration
to catch systems configured like this and show a warning.
When cross-compiling, this assumes that the system where dbus is built
(the build system in Autotools/Meson, or the "host" in CMake terminology)
has its /var/run and /run set up in a way that is compatible with the
system where dbus will run (the host system in Autotools/Meson, or the
"target" in CMake terminology). This is not 100% correct, but seems good
enough for a warning that will hopefully only trigger for misguided OS
distributors.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Diffstat (limited to 'tools')
-rwxr-xr-x | tools/check-runstatedir.sh | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/tools/check-runstatedir.sh b/tools/check-runstatedir.sh new file mode 100755 index 00000000..75eb713d --- /dev/null +++ b/tools/check-runstatedir.sh @@ -0,0 +1,77 @@ +#!/bin/sh +# Copyright 2022 Collabora Ltd. +# SPDX-License-Identifier: MIT + +# Usage: check-runstatedir.sh /run/dbus/system_bus_socket + +set -e +set -u + +same_file () { + # Many shells implement test -ef (test whether two names point to + # the same file), but POSIX doesn't require it, so fall back to + # comparing realpath output if necessary. We prefer test -ef if + # available, since it does the right thing for bind-mounts, not just + # symlinks + if test / -ef / 2>/dev/null; then + test "$1" -ef "$2" + else + test "$(realpath "$1")" = "$(realpath "$2")" + fi +} + +if [ -e /run ] && [ -e /var/run ] && ! same_file /run /var/run; then + echo + echo "WARNING: /run and /var/run are not the same directory." + echo "| Tools that do not agree on whether a socket is in /run or in" + echo "| /var/run will fail to interoperate." + echo "| Ask your OS distributor to make these two directories equivalent" + echo "| via a symbolic link or bind mount: there is no useful reason to" + echo "| make them different." + echo +fi + +system_socket="$1" + +case "$system_socket" in + (/run/dbus/system_bus_socket) + # --with-system-socket=/run/dbus/system_bus_socket + if ! same_file /run /var/run; then + echo + echo "WARNING: system bus socket: /run/dbus/system_bus_socket" + echo "| The system bus has been configured to listen on" + echo "| /run/dbus/system_bus_socket, but /run is not the same" + echo "| as /var/run on this system." + echo "|" + echo "| Most D-Bus implementations will expect to find the D-Bus" + echo "| system bus socket at /var/run/dbus/system_bus_socket." + echo "| Consider creating a symbolic link." + echo + fi + ;; + + (/var/run/dbus/system_bus_socket) + # e.g. --localstatedir=/var + if ! same_file /run /var/run; then + echo + echo "NOTE: system bus socket: /var/run/dbus/system_bus_socket" + echo "| The system bus has been configured to listen on" + echo "| /var/run/dbus/system_bus_socket, but /run is not the same" + echo "| as /var/run on this system." + echo "|" + echo "| Some D-Bus implementations might expect to find the" + echo "| D-Bus system bus socket at /run/dbus/system_bus_socket." + echo "| Consider creating a symbolic link." + echo + fi + ;; + + (*) + # e.g. --prefix=/opt/dbus + echo + echo "NOTE: system bus listens on $system_socket" + echo "| This build of dbus will not interoperate with the well-known" + echo "| system bus socket, /var/run/dbus/system_bus_socket." + echo + ;; +esac |