+ if (arg_user) {
+
+ /* Note that this resolves user names
+ * inside the container, and hence
+ * accesses the NSS modules from the
+ * container and not the host. This is
+ * a bit weird... */
+
+ if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
+ log_error("get_user_creds() failed: %m");
+ goto child_fail;
+ }
+
+ if (mkdir_parents_label(home, 0775) < 0) {
+ log_error("mkdir_parents_label() failed: %m");
+ goto child_fail;
+ }
+
+ if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
+ log_error("mkdir_safe_label() failed: %m");
+ goto child_fail;
+ }
+
+ if (initgroups((const char*)arg_user, gid) < 0) {
+ log_error("initgroups() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresgid(gid, gid, gid) < 0) {
+ log_error("setregid() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresuid(uid, uid, uid) < 0) {
+ log_error("setreuid() failed: %m");
+ goto child_fail;
+ }
+ } else {
+ /* Reset everything fully to 0, just in case */
+
+ if (setgroups(0, NULL) < 0) {
+ log_error("setgroups() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresgid(0, 0, 0) < 0) {
+ log_error("setregid() failed: %m");
+ goto child_fail;
+ }
+
+ if (setresuid(0, 0, 0) < 0) {
+ log_error("setreuid() failed: %m");
+ goto child_fail;
+ }
+ }
+
+ if ((asprintf((char**)(envp + n_env++), "HOME=%s", home ? home: "/root") < 0) ||
+ (asprintf((char**)(envp + n_env++), "USER=%s", arg_user ? arg_user : "root") < 0) ||
+ (asprintf((char**)(envp + n_env++), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
+ log_oom();