Allow udev rules to be configured at build time [#25]

Prior to this change, the udev rules were fixed to allow read-write
access only to the `plugdev` group. However, while this is the default
group for USB input devices on Debian and its derivatives, this is not
true for some systems such as openSUSE, which use `input` as the group.

This change adds a `--with-input-group` argument to `configure`, which
defaults to `plugdev`. This change also updates the install
documentation to reflect the new options.

INSTALL.md

@@ -56,3 +56,23 @@ You will also need the following packages to run the unit tests:
 make && sudo make install
 ```
 
+## Configuration options
+
+### udev
+
+The configuration system should automatically detect the udev rules directory,
+but you can override it by using the following argument to `configure`:
+
+```
+--with-udevrulesdir=/path/to/udev/rules.d
+```
+
+### Input group
+
+The udev rules that are installed provide read/write access to members of the
+input devices group. This defaults to `plugdev`, but can be modified using
+the following argument to `configure`:
+
+```
+--with-input-group=group
+```

configure.ac

@@ -74,6 +74,12 @@ AC_ARG_WITH([udevrulesdir],
     [udevrulesdir=$($PKG_CONFIG --variable=udevdir udev)"/rules.d"])
 AC_SUBST([udevrulesdir], [$udevrulesdir])
 
+AC_ARG_WITH([input-group],
+    AS_HELP_STRING([--with-input-group=GROUP], [Group allowed to access input devices]),
+    [input_group=$withval],
+    [input_group=plugdev])
+AC_SUBST([input_group], [$input_group])
+
 # Doxygen Support
 AC_CHECK_PROGS([DOXYGEN], [doxygen])
 AM_CONDITIONAL([HAVE_DOXYGEN], [test -n "$DOXYGEN"])
@@ -107,6 +113,7 @@ AC_CONFIG_FILES([ po/Makefile.in
     lib/libx52util/Makefile
     lib/libx52io/Makefile
     udev/Makefile
+    udev/60-saitek-x52-x52pro.rules
     utils/Makefile
     utils/cli/Makefile
     utils/test/Makefile

udev/60-saitek-x52-x52pro.rules.in

@@ -1,17 +1,17 @@
-# udev rules to give plugdev users permissions to:
+# udev rules to give members of "@input_group@" users permissions to:
 # - write to the X52/X52pro using libx52
 # - read from the hidraw interface
 ACTION!="add", GOTO="x52_rules_end"
 
 # X52Pro flight control system
-SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0762", MODE="0664", GROUP="plugdev"
+SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0762", MODE="0664", GROUP="@input_group@"
-SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0762", MODE="0640", GROUP="plugdev"
+SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0762", MODE="0640", GROUP="@input_group@"
 
 # X52 flight control system
-SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0255", MODE="0664", GROUP="plugdev"
+SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0255", MODE="0664", GROUP="@input_group@"
-SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0255", MODE="0640", GROUP="plugdev"
+SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="0255", MODE="0640", GROUP="@input_group@"
-SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="075c", MODE="0664", GROUP="plugdev"
+SUBSYSTEM=="usb", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="075c", MODE="0664", GROUP="@input_group@"
-SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="075c", MODE="0640", GROUP="plugdev"
+SUBSYSTEM=="hidraw", ATTRS{idVendor}=="06a3", ATTRS{idProduct}=="075c", MODE="0640", GROUP="@input_group@"
 
 LABEL="x52_rules_end"