user-sessions: move into own subdir and build independently of logind

Suggested by Zbyszek on IRC.

[zj: /run/nologin is used with PAM. systemd-user-session is independent
     of logind.]

2 files changed, 81 insertions, 0 deletions

diff --git a/src/user-sessions/Makefile b/src/user-sessions/Makefile
new file mode 120000
index 0000000000..d0b0e8e008
--- /dev/null
+++ b/src/user-sessions/Makefile
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/user-sessions/user-sessions.c b/src/user-sessions/user-sessions.c
new file mode 100644
index 0000000000..1c31769fde
--- /dev/null
+++ b/src/user-sessions/user-sessions.c
@@ -0,0 +1,80 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <unistd.h>
+#include <errno.h>
+
+#include "log.h"
+#include "util.h"
+#include "fileio.h"
+
+int main(int argc, char*argv[]) {
+
+        if (argc != 2) {
+                log_error("This program requires one argument.");
+                return EXIT_FAILURE;
+        }
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        umask(0022);
+
+        if (streq(argv[1], "start")) {
+                int r = 0;
+
+                if (unlink("/run/nologin") < 0 && errno != ENOENT) {
+                        log_error_errno(errno, "Failed to remove /run/nologin file: %m");
+                        r = -errno;
+                }
+
+                if (unlink("/etc/nologin") < 0 && errno != ENOENT) {
+                        /* If the file doesn't exist and /etc simply
+                         * was read-only (in which case unlink()
+                         * returns EROFS even if the file doesn't
+                         * exist), don't complain */
+
+                        if (errno != EROFS || access("/etc/nologin", F_OK) >= 0) {
+                                log_error_errno(errno, "Failed to remove /etc/nologin file: %m");
+                                return EXIT_FAILURE;
+                        }
+                }
+
+                if (r < 0)
+                        return EXIT_FAILURE;
+
+        } else if (streq(argv[1], "stop")) {
+                int r;
+
+                r = write_string_file_atomic("/run/nologin", "System is going down.");
+                if (r < 0) {
+                        log_error_errno(r, "Failed to create /run/nologin: %m");
+                        return EXIT_FAILURE;
+                }
+
+        } else {
+                log_error("Unknown verb %s.", argv[1]);
+                return EXIT_FAILURE;
+        }
+
+        return EXIT_SUCCESS;
+}