auto-getty: rework auto console getty logic to work in conjunction with single user mode

1 files changed, 189 insertions, 0 deletions

diff --git a/src/auto-console-getty.c b/src/auto-console-getty.c
new file mode 100644
index 0000000000..44d2eff732
--- /dev/null
+++ b/src/auto-console-getty.c
@@ -0,0 +1,189 @@
+/*-*- 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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <dbus/dbus.h>
+
+#include "util.h"
+#include "log.h"
+#include "dbus-common.h"
+
+static int spawn_getty(DBusConnection *bus, const char *console) {
+        DBusMessage *m = NULL, *reply = NULL;
+        DBusError error;
+        const char *fail = "fail";
+        char *name;
+        int r = -EIO;
+
+        dbus_error_init(&error);
+
+        assert(bus);
+        assert(console);
+
+        /* FIXME: we probably should escape the tty name properly here */
+        if (asprintf(&name, "getty@%s.service", console) < 0)
+                return -ENOMEM;
+
+        if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartUnit"))) {
+                log_error("Could not allocate message.");
+                goto finish;
+        }
+
+        if (!dbus_message_append_args(m,
+                                      DBUS_TYPE_STRING, &name,
+                                      DBUS_TYPE_STRING, &fail,
+                                      DBUS_TYPE_INVALID)) {
+                log_error("Could not attach target and flag information to message.");
+                goto finish;
+        }
+
+        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
+                log_error("Failed to start unit: %s", error.message);
+                goto finish;
+        }
+
+        r = 0;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        dbus_error_free(&error);
+
+        free(name);
+
+        return r;
+}
+
+static int parse_proc_cmdline_word(const char *word, char **console) {
+        assert(word);
+
+        if (startswith(word, "console=")) {
+                const char *k;
+                size_t l;
+                char *w = NULL;
+
+                k = word + 8;
+                l = strcspn(k, ",");
+
+                if (l < 4 ||
+                    !startswith(k, "tty") ||
+                    k[3+strspn(k+3, "0123456789")] != 0) {
+
+                        if (!(w = strndup(k, l)))
+                                return -ENOMEM;
+
+                }
+
+                free(*console);
+                *console = w;
+        }
+
+        return 0;
+}
+
+static int parse_proc_cmdline(char **console) {
+        char *line;
+        int r;
+        char *w;
+        size_t l;
+        char *state;
+
+        assert(console);
+
+        if ((r = read_one_line_file("/tmp/cmdline", &line)) < 0) {
+                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+                return 0;
+        }
+
+        FOREACH_WORD_QUOTED(w, l, line, state) {
+                char *word;
+
+                if (!(word = strndup(w, l))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                r = parse_proc_cmdline_word(word, console);
+                free(word);
+
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+
+finish:
+        free(line);
+        return r;
+}
+
+int main(int argc, char *argv[]) {
+        DBusError error;
+        int r = 1;
+        char *console = NULL;
+        DBusConnection *bus = NULL;
+
+        dbus_error_init(&error);
+
+        if (argc > 1) {
+                log_error("This program does not take arguments.");
+                return 1;
+        }
+
+        log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+        log_parse_environment();
+        log_open();
+
+        if (bus_connect(DBUS_BUS_SYSTEM, &bus, NULL, &error) < 0) {
+                log_error("Failed to get D-Bus connection: %s", error.message);
+                goto finish;
+        }
+
+        if (parse_proc_cmdline(&console) < 0)
+                goto finish;
+
+        if (console)
+                if (spawn_getty(bus, console) < 0)
+                        goto finish;
+
+        r = 0;
+
+finish:
+        free(console);
+
+        if (bus) {
+               dbus_connection_close(bus);
+               dbus_connection_unref(bus);
+        }
+
+        dbus_error_free(&error);
+
+        dbus_shutdown();
+
+        return r;
+}