libkmod, depmod: Load modprobe.d, depmod.d from ${prefix}/lib.

There is an ongoing effort to limit use of files outside of /usr (or
${prefix} on general). Currently all modprobe.d paths are hardcoded to
outside of $prefix. Teach kmod to load modprobe.d from ${prefix}/lib.

On some distributions /usr/lib and /lib are the same directory because
of a compatibility symlink, and it is possible to craft configuration
files with sideeffects that would behave differently when loaded twice.
However, the override semantic ensures that one 'overrides' the other,
and only one configuration file of the same name is loaded from any of
the search directories.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Link: https://lore.kernel.org/r/a290343ce32e2a3c25b134e4f27c13b26e06c9e0.1689681454.git.msuchanek@suse.de
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

7 files changed, 20 insertions, 5 deletions

diff --git a/Makefile.am b/Makefile.am
index 5b7abfe..e6630a3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -19,6 +19,7 @@ AM_CPPFLAGS = \
 	-include $(top_builddir)/config.h \
 	-I$(top_srcdir) \
 	-DSYSCONFDIR=\""$(sysconfdir)"\" \
+	-DDISTCONFDIR=\""$(distconfdir)"\" \
 	${zlib_CFLAGS}
 
 AM_CFLAGS = $(OUR_CFLAGS)
diff --git a/configure.ac b/configure.ac
index e5bceea..fd88d1f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -79,6 +79,10 @@ AC_COMPILE_IFELSE(
 # --with-
 #####################################################################
 
+AC_ARG_WITH([distconfdir], AS_HELP_STRING([--with-distconfdir=DIR], [directory to search for distribution configuration files]),
+        [], [with_distconfdir='${prefix}/lib'])
+AC_SUBST([distconfdir], [$with_distconfdir])
+
 AC_ARG_WITH([rootlibdir],
         AS_HELP_STRING([--with-rootlibdir=DIR], [rootfs directory to install shared libraries]),
         [], [with_rootlibdir=$libdir])
@@ -313,6 +317,7 @@ AC_MSG_RESULT([
 
 	prefix:			${prefix}
 	sysconfdir:		${sysconfdir}
+	distconfdir:		${distconfdir}
 	libdir:			${libdir}
 	rootlibdir:		${rootlibdir}
 	includedir:		${includedir}
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 1b8773c..57fac1c 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -65,6 +65,7 @@ static const char *const default_config_paths[] = {
 	SYSCONFDIR "/modprobe.d",
 	"/run/modprobe.d",
 	"/usr/local/lib/modprobe.d",
+	DISTCONFDIR "/modprobe.d",
 	"/lib/modprobe.d",
 	NULL
 };
@@ -272,9 +273,9 @@ static enum kmod_file_compression_type get_kernel_compression(struct kmod_ctx *c
  *                to load from user-defined configuration parameters such as
  *                alias, blacklists, commands (install, remove). If NULL
  *                defaults to /etc/modprobe.d, /run/modprobe.d,
- *                /usr/local/lib/modprobe.d and /lib/modprobe.d. Give an empty
- *                vector if configuration should not be read. This array must
- *                be null terminated.
+ *                /usr/local/lib/modprobe.d, DISTCONFDIR/modprobe.d, and
+ *                /lib/modprobe.d. Give an empty vector if configuration should
+ *                not be read. This array must be null terminated.
  *
  * Create kmod library context. This reads the kmod configuration
  * and fills in the default values.
diff --git a/man/Makefile.am b/man/Makefile.am
index 11514d5..2fea8e4 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -17,9 +17,14 @@ EXTRA_DIST = $(MAN5:%.5=%.xml) $(MAN8:%.8=%.xml)
 CLEANFILES = $(dist_man_MANS)
 
 %.5 %.8: %.xml
-	$(AM_V_XSLT)$(XSLT) \
+	$(AM_V_XSLT)if [ '$(distconfdir)' != '/lib' ] ; then \
+		sed -e 's|@DISTCONFDIR@|$(distconfdir)|g' $< ; \
+	else \
+		sed -e '/@DISTCONFDIR@/d' $< ; \
+	fi | \
+	$(XSLT) \
 		-o $@ \
 		--nonet \
 		--stringparam man.output.quietly 1 \
 		--param funcsynopsis.style "'ansi'" \
-		http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl $<
+		http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl -
diff --git a/man/depmod.d.xml b/man/depmod.d.xml
index 8d3d821..f282a39 100644
--- a/man/depmod.d.xml
+++ b/man/depmod.d.xml
@@ -40,6 +40,7 @@
 
   <refsynopsisdiv>
     <para><filename>/lib/depmod.d/*.conf</filename></para>
+    <para><filename>@DISTCONFDIR@/depmod.d/*.conf</filename></para>
     <para><filename>/usr/local/lib/depmod.d/*.conf</filename></para>
     <para><filename>/run/depmod.d/*.conf</filename></para>
     <para><filename>/etc/depmod.d/*.conf</filename></para>
diff --git a/man/modprobe.d.xml b/man/modprobe.d.xml
index 0ab3e91..2bf6537 100644
--- a/man/modprobe.d.xml
+++ b/man/modprobe.d.xml
@@ -41,6 +41,7 @@
 
   <refsynopsisdiv>
     <para><filename>/lib/modprobe.d/*.conf</filename></para>
+    <para><filename>@DISTCONFDIR@/modprobe.d/*.conf</filename></para>
     <para><filename>/usr/local/lib/modprobe.d/*.conf</filename></para>
     <para><filename>/run/modprobe.d/*.conf</filename></para>
     <para><filename>/etc/modprobe.d/*.conf</filename></para>
diff --git a/tools/depmod.c b/tools/depmod.c
index 1d1d41d..630fef9 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -54,6 +54,7 @@ static const char *const default_cfg_paths[] = {
 	SYSCONFDIR "/depmod.d",
 	"/run/depmod.d",
 	"/usr/local/lib/depmod.d",
+	DISTCONFDIR "/depmod.d",
 	"/lib/depmod.d",
 	NULL
 };