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>

7 files changed, 85 insertions, 4 deletions

diff --git a/src/librc/librc.c b/src/librc/librc.c
index fe9e1b6b..6d823434 100644
--- a/src/librc/librc.c
+++ b/src/librc/librc.c
@@ -199,7 +199,51 @@ file_regex(const char *file, const char *regex)
 #endif
 
 const char *
-rc_sys(void)
+rc_sys_v2(void)
+{
+#define __STRING_SWITCH(x) { char* __string_switch = x; if(false) {}
+#define __STRING_CASE(y) else if(strcmp(__string_switch,y) == 0)
+#define __STRING_SWITCH_END() }
+	char* systype = rc_conf_value("rc_sys");
+	/* New sys identification code */
+	if(systype) {
+		char* s = systype;
+		// Convert to uppercase
+		while(s && *s) { 
+			if(islower((unsigned char)*s))
+				*s = toupper((unsigned char)*s); 
+			s++;
+		}
+		// Now do detection
+		__STRING_SWITCH(systype)
+		__STRING_CASE(RC_SYS_PREFIX)	{ return RC_SYS_PREFIX; }
+#ifdef __FreeBSD__
+		__STRING_CASE(RC_SYS_JAIL) { return RC_SYS_JAIL; }
+#endif /* __FreeBSD__ */
+#ifdef __NetBSD__
+		__STRING_CASE(RC_SYS_XEN0) { return RC_SYS_XEN0; }
+		__STRING_CASE(RC_SYS_XENU) { return RC_SYS_XENU; }
+#endif /* __NetBSD__ */
+#ifdef __linux__
+		__STRING_CASE(RC_SYS_XEN0) { return RC_SYS_XEN0; }
+		__STRING_CASE(RC_SYS_XENU) { return RC_SYS_XENU; }
+		__STRING_CASE(RC_SYS_UML) { return RC_SYS_UML; }
+		__STRING_CASE(RC_SYS_VSERVER) { return RC_SYS_VSERVER; }
+		__STRING_CASE(RC_SYS_OPENVZ) { return RC_SYS_OPENVZ; }
+		__STRING_CASE(RC_SYS_LXC) { return RC_SYS_LXC; }
+#endif /* __linux__ */
+		__STRING_SWITCH_END()
+	}
+#undef __STRING_SWITCH
+#undef __STRING_CASE
+#undef __STRING_SWITCH_END
+	return NULL;
+}
+librc_hidden_def(rc_sys_v2)
+
+/* Old sys identification code */
+const char *
+rc_sys_v1(void)
 {
 #ifdef PREFIX
 	return RC_SYS_PREFIX;
@@ -243,6 +287,15 @@ rc_sys(void)
 	return NULL;
 #endif /* PREFIX */
 }
+librc_hidden_def(rc_sys_v1)
+
+const char *
+rc_sys(void)
+{
+	const char *s = rc_sys_v2();
+	if(s) return s;
+	return rc_sys_v1();
+}
 librc_hidden_def(rc_sys)
 
 static const char *
diff --git a/src/librc/librc.h b/src/librc/librc.h
index fc87bb10..dc97f1d3 100644
--- a/src/librc/librc.h
+++ b/src/librc/librc.h
@@ -125,6 +125,8 @@ librc_hidden_proto(rc_stringlist_new)
 librc_hidden_proto(rc_stringlist_split)
 librc_hidden_proto(rc_stringlist_sort)
 librc_hidden_proto(rc_sys)
+librc_hidden_proto(rc_sys_v1)
+librc_hidden_proto(rc_sys_v2)
 librc_hidden_proto(rc_yesno)
 
 #endif
diff --git a/src/librc/rc.h.in b/src/librc/rc.h.in
index d9d04539..3d0ffb42 100644
--- a/src/librc/rc.h.in
+++ b/src/librc/rc.h.in
@@ -274,8 +274,19 @@ bool rc_service_daemons_crashed(const char *);
 #define RC_SYS_VSERVER "VSERVER"
 #define RC_SYS_XEN0    "XEN0"
 #define RC_SYS_XENU    "XENU"
+
+/*! Returns the type of subsystem
+ * @return string from RC_SYS_* types or NULL if none detected */
 const char *rc_sys(void);
 
+/*! Returns the type of subsystem using old automatic code
+ * @return string from RC_SYS_* types or NULL if none detected */
+const char *rc_sys_v1(void);
+
+/*! Returns the type of subsystem using new rc.conf rc_sys value
+ * @return string from RC_SYS_* types or NULL if none detected */
+const char *rc_sys_v2(void);
+
 /*! @name Dependency options
  * These options can change the services found by the rc_get_depinfo and
  * rc_get_depends functions. */
diff --git a/src/librc/rc.map b/src/librc/rc.map
index 3f1e7e70..113f2d7d 100644
--- a/src/librc/rc.map
+++ b/src/librc/rc.map
@@ -55,6 +55,8 @@ global:
 	rc_stringlist_sort;
 	rc_stringlist_free;
 	rc_sys;
+	rc_sys_v1;
+	rc_sys_v2;
 	rc_yesno;
 
 local:
diff --git a/src/rc/rc.c b/src/rc/rc.c
index ccafbe38..b062349a 100644
--- a/src/rc/rc.c
+++ b/src/rc/rc.c
@@ -878,9 +878,16 @@ main(int argc, char **argv)
 			eerrorx("%s: %s", applet, strerror(errno));
 			/* NOTREACHED */
 		case 'S':
-			bootlevel = rc_sys();
-			if (bootlevel)
-				printf("%s\n", bootlevel);
+			if (rc_conf_value("rc_sys")) {
+				bootlevel = rc_sys_v2();
+				if(bootlevel)
+					printf("%s\n", bootlevel);
+			} else {
+				ewarn("WARNING: rc_sys not defined in rc.conf. Falling back to automatic detection");
+				bootlevel = rc_sys_v1();
+				if(bootlevel)
+					printf("%s\n", bootlevel);
+			}
 			exit(EXIT_SUCCESS);
 			/* NOTREACHED */
 			case_RC_COMMON_GETOPT
diff --git a/src/test/librc.funcs.hidden.list b/src/test/librc.funcs.hidden.list
index 121bfcf0..b661850f 100644
--- a/src/test/librc.funcs.hidden.list
+++ b/src/test/librc.funcs.hidden.list
@@ -51,4 +51,6 @@ rc_stringlist_new
 rc_stringlist_sort
 rc_stringlist_split
 rc_sys
+rc_sys_v1
+rc_sys_v2
 rc_yesno
diff --git a/src/test/rc.funcs.list b/src/test/rc.funcs.list
index b67c0d8f..0aac8f9a 100644
--- a/src/test/rc.funcs.list
+++ b/src/test/rc.funcs.list
@@ -104,5 +104,9 @@ rc_stringlist_split
 rc_stringlist_split@@RC_1.0
 rc_sys
 rc_sys@@RC_1.0
+rc_sys_v1
+rc_sys_v1@@RC_1.0
+rc_sys_v2
+rc_sys_v2@@RC_1.0
 rc_yesno
 rc_yesno@@RC_1.0