unit: add minimal condition checker for unit startup

1 files changed, 65 insertions, 0 deletions

diff --git a/src/load-fragment.c b/src/load-fragment.c
index eb9861802b..2b5c8e70dd 100644
--- a/src/load-fragment.c
+++ b/src/load-fragment.c
@@ -1400,6 +1400,67 @@ static int config_parse_ip_tos(
         return 0;
 }
 
+static int config_parse_condition_path(
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Unit *u = data;
+        bool negate;
+        Condition *c;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if ((negate = rvalue[0] == '!'))
+                rvalue++;
+
+        if (!path_is_absolute(rvalue)) {
+                log_error("[%s:%u] Path in condition not absolute: %s", filename, line, rvalue);
+                return 0;
+        }
+
+        if (!(c = condition_new(CONDITION_PATH_EXISTS, rvalue, negate)))
+                return -ENOMEM;
+
+        LIST_PREPEND(Condition, conditions, u->meta.conditions, c);
+        return 0;
+}
+
+static int config_parse_condition_kernel(
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Unit *u = data;
+        bool negate;
+        Condition *c;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if ((negate = rvalue[0] == '!'))
+                rvalue++;
+
+        if (!(c = condition_new(CONDITION_KERNEL_COMMAND_LINE, rvalue, negate)))
+                return -ENOMEM;
+
+        LIST_PREPEND(Condition, conditions, u->meta.conditions, c);
+        return 0;
+}
+
 static DEFINE_CONFIG_PARSE_ENUM(config_parse_notify_access, notify_access, NotifyAccess, "Failed to parse notify access specifier");
 
 #define FOLLOW_MAX 8
@@ -1571,6 +1632,8 @@ static void dump_items(FILE *f, const ConfigItem *items) {
                 { config_parse_path_unit,        "UNIT" },
                 { config_parse_notify_access,    "ACCESS" },
                 { config_parse_ip_tos,           "TOS" },
+                { config_parse_condition_path,   "CONDITION" },
+                { config_parse_condition_kernel, "CONDITION" },
         };
 
         assert(f);
@@ -1692,6 +1755,8 @@ static int load_from_path(Unit *u, const char *path) {
                 { "DefaultDependencies",    config_parse_bool,            &u->meta.default_dependencies,                   "Unit"    },
                 { "IgnoreDependencyFailure",config_parse_bool,            &u->meta.ignore_dependency_failure,              "Unit"    },
                 { "JobTimeoutSec",          config_parse_usec,            &u->meta.job_timeout,                            "Unit"    },
+                { "ConditionPathExists",    config_parse_condition_path,  u,                                               "Unit"    },
+                { "ConditionKernelCommandLine", config_parse_condition_kernel, u,                                          "Unit"    },
 
                 { "PIDFile",                config_parse_path,            &u->service.pid_file,                            "Service" },
                 { "ExecStartPre",           config_parse_exec,            u->service.exec_command+SERVICE_EXEC_START_PRE,  "Service" },