[systemd-devel] [PATCH 3/4] condition: add ConditionSELinux

[Michal Schmidt]

Using ConditionSELinux a unit can depend on the SELinux state:
 disabled, permissive, enforcing
A bool argument is also accepted:
 no  = disabled
 yes = permissive | enforcing

I'd like to use this feature for a unit that creates /.autorelabel if
SELinux is disabled, to ensure a relabel is done automatically when the
system is later rebooted with SELinux enabled.
---

 src/condition.c     |   41 +++++++++++++++++++++++++++++++++++++++++
 src/condition.h     |    1 +
 src/load-fragment.c |    1 +
 3 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/src/condition.c b/src/condition.c
index 5ab77d8..60e696f 100644
--- a/src/condition.c
+++ b/src/condition.c
@@ -24,6 +24,10 @@
 #include <string.h>
 #include <unistd.h>
 
+#ifdef HAVE_SELINUX
+#include <selinux/selinux.h>
+#endif
+
 #include "util.h"
 #include "condition.h"
 
@@ -128,6 +132,39 @@ static bool test_virtualization(const char *parameter) {
         return streq(parameter, id);
 }
 
+static bool test_selinux(const char *parameter) {
+        int enforce, b;
+        const char *mode;
+
+#ifdef HAVE_SELINUX
+        static const char * const mode_table[] = {
+                "disabled",
+                "permissive",
+                "enforcing"
+        };
+
+        enforce = security_getenforce();
+        assert(enforce >= -1 && enforce <= 1);
+        mode = mode_table[enforce + 1];
+#else
+        enforce = -1;
+        mode = "disabled";
+#endif
+
+        if (streq(parameter, mode))
+                return true;
+
+        b = parse_boolean(parameter);
+
+        if (enforce >= 0 && b > 0)
+                return true;
+
+        if (enforce < 0 && b == 0)
+                return true;
+
+        return false;
+}
+
 bool condition_test(Condition *c) {
         assert(c);
 
@@ -157,6 +194,9 @@ bool condition_test(Condition *c) {
         case CONDITION_VIRTUALIZATION:
                 return test_virtualization(c->parameter) == !c->negate;
 
+        case CONDITION_SELINUX:
+                return test_selinux(c->parameter) == !c->negate;
+
         case CONDITION_NULL:
                 return !c->negate;
 
@@ -220,6 +260,7 @@ static const char* const condition_type_table[_CONDITION_TYPE_MAX] = {
         [CONDITION_DIRECTORY_NOT_EMPTY] = "ConditionDirectoryNotEmpty",
         [CONDITION_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine",
         [CONDITION_VIRTUALIZATION] = "ConditionVirtualization",
+        [CONDITION_SELINUX] = "ConditionSELinux",
         [CONDITION_NULL] = "ConditionNull"
 };
 
diff --git a/src/condition.h b/src/condition.h
index 9913c8c..0167b61 100644
--- a/src/condition.h
+++ b/src/condition.h
@@ -32,6 +32,7 @@ typedef enum ConditionType {
         CONDITION_DIRECTORY_NOT_EMPTY,
         CONDITION_KERNEL_COMMAND_LINE,
         CONDITION_VIRTUALIZATION,
+        CONDITION_SELINUX,
         CONDITION_NULL,
         _CONDITION_TYPE_MAX,
         _CONDITION_TYPE_INVALID = -1
diff --git a/src/load-fragment.c b/src/load-fragment.c
index cb8c250..94adc6f 100644
--- a/src/load-fragment.c
+++ b/src/load-fragment.c
@@ -1853,6 +1853,7 @@ static int load_from_path(Unit *u, const char *path) {
                 { "ConditionDirectoryNotEmpty", config_parse_condition_path, CONDITION_DIRECTORY_NOT_EMPTY, u,                "Unit"    },
                 { "ConditionKernelCommandLine", config_parse_condition_string, CONDITION_KERNEL_COMMAND_LINE, u,              "Unit"    },
                 { "ConditionVirtualization",    config_parse_condition_string, CONDITION_VIRTUALIZATION, u,                   "Unit"    },
+                { "ConditionSELinux",           config_parse_condition_string, CONDITION_SELINUX, u,                          "Unit"    },
                 { "ConditionNull",          config_parse_condition_null,  0, u,                                               "Unit"    },
 
                 { "PIDFile",                config_parse_path,            0, &u->service.pid_file,                            "Service" },