Implement explicit selection of subsystem types.

- Fixes bugs #347583, #349389, both of which were triggered by cgroups
  being detected as the LXC subsystem type.
- Makes it much easier to select "prefix" type.
- "rc -S" will now print a warning if you have not configured rc_sys in
  /etc/rc.conf
- All other semantics of rc_sys are unchanged in this patch.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

etc/Makefile

@@ -7,3 +7,6 @@ MK=	../mk
 include ${MK}/os.mk
 include Makefile.${OS}
 include ${MK}/scripts.mk
+
+rc.conf: rc.conf.in rc.conf.${OS}
+	${SED} ${SED_REPLACE} ${SED_EXTRA} $^ > $@

etc/Makefile.Linux

@@ -1,6 +1,2 @@
 SED_EXTRA=	-e 's:@TERM@:wsvt25:g'
-SRCS+=		rc.in rc.shutdown.in
-
-rc.conf:
-	cp rc.conf.in rc.conf
-	cat rc.conf.Linux >> rc.conf
+SRCS+=		rc.conf.in rc.in rc.shutdown.in

etc/rc.conf.FreeBSD

@@ -0,0 +1,8 @@
+# This is the subsystem type. Valid options on FreeBSD:
+# ""        - nothing special
+# "jail"    - FreeBSD jails
+# "prefix"  - Prefix
+# If unset, the old automagic detection code will be triggered. Said old code
+# is deprecated and be removed not later than 2010/03/01.
+rc_sys=""
+

etc/rc.conf.Linux

@@ -1,3 +1,15 @@
+# This is the subsystem type. Valid options on Linux:
+# ""        - nothing special
+# "lxc"     - Linux Containers
+# "openvz"  - Linux OpenVZ
+# "prefix"  - Prefix
+# "uml"     - Usermode Linux
+# "vserver" - Linux vserver
+# "xen0"    - Xen0 Domain
+# "xenU"    - XenU Domain
+# If unset, the old automagic detection code will be triggered. Said old code
+# is deprecated and be removed not later than 2010/03/01.
+rc_sys=""
 
 ##############################################################################
 # LINUX SPECIFIC OPTIONS

etc/rc.conf.NetBSD

@@ -0,0 +1,9 @@
+# This is the subsystem type. Valid options on NetBSD:
+# ""        - nothing special
+# "prefix"  - Prefix
+# "xen0"    - Xen0 Domain
+# "xenU"    - XenU Domain
+# If unset, the old automagic detection code will be triggered. Said old code
+# is deprecated and be removed not later than 2010/03/01.
+rc_sys=""
+

etc/rc.conf.in

@@ -115,3 +115,4 @@
 # You can also remove dependencies.
 # This is mainly used for saying which servies do NOT provide net.
 #rc_net_tap0_provide="!net"
+