logind: implement delay inhibitor locks in addition to block inhibitor locks

This is useful to allow applications to synchronously save data before
the system is suspended or shut down.

1 files changed, 353 insertions, 0 deletions

diff --git a/src/login/inhibit.c b/src/login/inhibit.c
new file mode 100644
index 0000000000..a817c84b36
--- /dev/null
+++ b/src/login/inhibit.c
@@ -0,0 +1,353 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 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 <getopt.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <dbus.h>
+#include <unistd.h>
+
+#include "dbus-common.h"
+#include "util.h"
+#include "build.h"
+#include "strv.h"
+
+static const char* arg_what = "idle:suspend:shutdown";
+static const char* arg_who = NULL;
+static const char* arg_why = "Unknown reason";
+static const char* arg_mode = "block";
+
+static enum {
+        ACTION_INHIBIT,
+        ACTION_LIST
+} arg_action = ACTION_INHIBIT;
+
+static int inhibit(DBusConnection *bus, DBusError *error) {
+        DBusMessage *m = NULL, *reply = NULL;
+        int fd;
+
+        assert(bus);
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "Inhibit");
+        if (!m)
+                return -ENOMEM;
+
+        if (!dbus_message_append_args(m,
+                                      DBUS_TYPE_STRING, &arg_what,
+                                      DBUS_TYPE_STRING, &arg_who,
+                                      DBUS_TYPE_STRING, &arg_why,
+                                      DBUS_TYPE_STRING, &arg_mode,
+                                      DBUS_TYPE_INVALID)) {
+                fd = -ENOMEM;
+                goto finish;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, error);
+        if (!reply) {
+                fd = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_get_args(reply, error,
+                                   DBUS_TYPE_UNIX_FD, &fd,
+                                   DBUS_TYPE_INVALID)){
+                fd = -EIO;
+                goto finish;
+        }
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        return fd;
+}
+
+static int print_inhibitors(DBusConnection *bus, DBusError *error) {
+        DBusMessage *m, *reply;
+        unsigned n = 0;
+        DBusMessageIter iter, sub, sub2;
+        int r;
+
+        assert(bus);
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "ListInhibitors");
+        if (!m)
+                return -ENOMEM;
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, error);
+        if (!reply) {
+                r = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_iter_init(reply, &iter)) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY) {
+                r = -EIO;
+                goto finish;
+        }
+        dbus_message_iter_recurse(&iter, &sub);
+
+        printf("%-21s %-20s %-20s %-5s %6s %6s\n",
+               "WHAT",
+               "WHO",
+               "WHY",
+               "MODE",
+               "UID",
+               "PID");
+
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *what, *who, *why, *mode;
+                char *ewho, *ewhy;
+                dbus_uint32_t uid, pid;
+
+                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
+                        r = -EIO;
+                        goto finish;
+                }
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &what, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &who, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &why, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &mode, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &uid, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &pid, false) < 0) {
+                        r = -EIO;
+                        goto finish;
+                }
+
+                ewho = ellipsize(who, 20, 66);
+                ewhy = ellipsize(why, 20, 66);
+
+                printf("%-21s %-20s %-20s %-5s %6lu %6lu\n",
+                       what, ewho ? ewho : who, ewhy ? ewhy : why, mode, (unsigned long) uid, (unsigned long) pid);
+
+                free(ewho);
+                free(ewhy);
+
+                dbus_message_iter_next(&sub);
+
+                n++;
+        }
+
+        printf("\n%u inhibitors listed.\n", n);
+        r = 0;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        return r;
+}
+
+static int help(void) {
+
+        printf("%s [OPTIONS...] {COMMAND} ...\n\n"
+               "Execute a process while inhibiting shutdown/suspend/idle.\n\n"
+               "  -h --help               Show this help\n"
+               "     --version            Show package version\n"
+               "     --what=WHAT          Operations to inhibit, colon separated list of idle,\n"
+               "                          suspend, shutdown\n"
+               "     --who=STRING         A descriptive string who is inhibiting\n"
+               "     --why=STRING         A descriptive string why is being inhibited\n"
+               "     --mode=MODE          One of block or delay\n"
+               "     --list               List active inhibitors\n",
+               program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_WHAT,
+                ARG_WHO,
+                ARG_WHY,
+                ARG_MODE,
+                ARG_LIST,
+        };
+
+        static const struct option options[] = {
+                { "help",         no_argument,       NULL, 'h'              },
+                { "version",      no_argument,       NULL, ARG_VERSION      },
+                { "what",         required_argument, NULL, ARG_WHAT         },
+                { "who",          required_argument, NULL, ARG_WHO          },
+                { "why",          required_argument, NULL, ARG_WHY          },
+                { "mode",         required_argument, NULL, ARG_MODE         },
+                { "list",         no_argument,       NULL, ARG_LIST         },
+                { NULL,           0,                 NULL, 0                }
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "+h", options, NULL)) >= 0) {
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(DISTRIBUTION);
+                        puts(SYSTEMD_FEATURES);
+                        return 0;
+
+                case ARG_WHAT:
+                        arg_what = optarg;
+                        break;
+
+                case ARG_WHO:
+                        arg_who = optarg;
+                        break;
+
+                case ARG_WHY:
+                        arg_why = optarg;
+                        break;
+
+                case ARG_MODE:
+                        arg_mode = optarg;
+                        break;
+
+                case ARG_LIST:
+                        arg_action = ACTION_LIST;
+                        break;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        return -EINVAL;
+                }
+        }
+
+        if (arg_action == ACTION_INHIBIT && optind >= argc) {
+                log_error("Missing command line to execute.");
+                return -EINVAL;
+        }
+
+        return 1;
+}
+
+int main(int argc, char *argv[]) {
+        int r, exit_code = 0;
+        DBusConnection *bus = NULL;
+        DBusError error;
+        int fd = -1;
+
+        dbus_error_init(&error);
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error);
+        if (!bus) {
+                log_error("Failed to connect to bus: %s", bus_error_message(&error));
+                r = -EIO;
+                goto finish;
+        }
+
+        if (arg_action == ACTION_LIST) {
+
+                r = print_inhibitors(bus, &error);
+                if (r < 0) {
+                        log_error("Failed to list inhibitors: %s", bus_error_message_or_strerror(&error, -r));
+                        goto finish;
+                }
+
+        } else {
+                char *w = NULL;
+                pid_t pid;
+
+                if (!arg_who)
+                        arg_who = w = strv_join(argv + optind, " ");
+
+                fd = inhibit(bus, &error);
+                free(w);
+
+                if (fd < 0) {
+                        log_error("Failed to inhibit: %s", bus_error_message_or_strerror(&error, -r));
+                        r = fd;
+                        goto finish;
+                }
+
+                pid = fork();
+                if (pid < 0) {
+                        log_error("Failed to fork: %m");
+                        r = -errno;
+                        goto finish;
+                }
+
+                if (pid == 0) {
+                        /* Child */
+
+                        close_nointr_nofail(fd);
+                        execvp(argv[optind], argv + optind);
+                        log_error("Failed to execute %s: %m", argv[optind]);
+                        _exit(EXIT_FAILURE);
+                }
+
+                r = wait_for_terminate_and_warn(argv[optind], pid);
+                if (r >= 0)
+                        exit_code = r;
+        }
+
+finish:
+        if (bus) {
+                dbus_connection_close(bus);
+                dbus_connection_unref(bus);
+        }
+
+        dbus_error_free(&error);
+
+        if (fd >= 0)
+                close_nointr_nofail(fd);
+
+        return r < 0 ? EXIT_FAILURE : exit_code;
+}