execude: include RuntimeScope field in ExecParameters

Let's decouple execute.c a bit from the Manager object, let's pass the
runtime scope (i.e. the enum that discern invocation for user or system
context) as part of ExecParameters. This makes the scope available in
various functions without having to pass the Manager object in.

src/core/execute.c

@@ -4066,7 +4066,7 @@ static int apply_mount_namespace(
                         return -ENOMEM;
         }
 
-        if (MANAGER_IS_SYSTEM(u->manager)) {
+        if (params->runtime_scope == RUNTIME_SCOPE_SYSTEM) {
                 propagate_dir = path_join("/run/systemd/propagate/", u->id);
                 if (!propagate_dir)
                         return -ENOMEM;
@@ -4078,9 +4078,12 @@ static int apply_mount_namespace(
                 extension_dir = strdup("/run/systemd/unit-extensions");
                 if (!extension_dir)
                         return -ENOMEM;
-        } else
+        } else {
+                assert(params->runtime_scope == RUNTIME_SCOPE_USER);
+
                 if (asprintf(&extension_dir, "/run/user/" UID_FMT "/systemd/unit-extensions", geteuid()) < 0)
                         return -ENOMEM;
+        }
 
         if (root_image) {
                 r = verity_settings_prepare(
@@ -4707,14 +4710,17 @@ static void log_command_line(Unit *unit, const char *msg, const char *executable
                         LOG_UNIT_INVOCATION_ID(unit));
 }
 
-static bool exec_context_need_unprivileged_private_users(const ExecContext *context, const Manager *manager) {
+static bool exec_context_need_unprivileged_private_users(
+                const ExecContext *context,
+                const ExecParameters *params) {
+
         assert(context);
-        assert(manager);
+        assert(params);
 
         /* These options require PrivateUsers= when used in user units, as we need to be in a user namespace
          * to have permission to enable them when not running as root. If we have effective CAP_SYS_ADMIN
          * (system manager) then we have privileges and don't need this. */
-        if (MANAGER_IS_SYSTEM(manager))
+        if (params->runtime_scope != RUNTIME_SCOPE_USER)
                 return false;
 
         return context->private_users ||
@@ -4924,7 +4930,7 @@ static int exec_child(
          * invocations themselves. Also note that while we'll only invoke NSS modules involved in user management they
          * might internally call into other NSS modules that are involved in hostname resolution, we never know. */
         if (setenv("SYSTEMD_ACTIVATION_UNIT", unit->id, true) != 0 ||
-            setenv("SYSTEMD_ACTIVATION_SCOPE", runtime_scope_to_string(unit->manager->runtime_scope), true) != 0) {
+            setenv("SYSTEMD_ACTIVATION_SCOPE", runtime_scope_to_string(params->runtime_scope), true) != 0) {
                 *exit_status = EXIT_MEMORY;
                 return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
         }
@@ -5392,7 +5398,7 @@ static int exec_child(
                 }
         }
 
-        if (needs_sandboxing && exec_context_need_unprivileged_private_users(context, unit->manager)) {
+        if (needs_sandboxing && exec_context_need_unprivileged_private_users(context, params)) {
                 /* If we're unprivileged, set up the user namespace first to enable use of the other namespaces.
                  * Users with CAP_SYS_ADMIN can set up user namespaces last because they will be able to
                  * set up the all of the other namespaces (i.e. network, mount, UTS) without a user namespace. */

src/core/execute.h

@@ -27,6 +27,7 @@ typedef struct Manager Manager;
 #include "numa-util.h"
 #include "open-file.h"
 #include "path-util.h"
+#include "runtime-scope.h"
 #include "set.h"
 #include "time-util.h"
 
@@ -418,6 +419,8 @@ typedef enum ExecFlags {
 /* Parameters for a specific invocation of a command. This structure is put together right before a command is
  * executed. */
 struct ExecParameters {
+        RuntimeScope runtime_scope;
+
         char **environment;
 
         int *fds;

src/core/unit.c

@@ -5309,6 +5309,8 @@ int unit_set_exec_params(Unit *u, ExecParameters *p) {
         if (r < 0)
                 return r;
 
+        p->runtime_scope = u->manager->runtime_scope;
+
         p->confirm_spawn = manager_get_confirm_spawn(u->manager);
         p->cgroup_supported = u->manager->cgroup_supported;
         p->prefix = u->manager->prefix;