1 files changed, 146 insertions, 0 deletions
diff --git a/src/udev/udevadm-settle.c b/src/udev/udevadm-settle.c
new file mode 100644
index 0000000..8d9c450
--- /dev/null
+++ b/src/udev/udevadm-settle.c
@@ -0,0 +1,146 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright © 2009 Canonical Ltd.
+ * Copyright © 2009 Scott James Remnant <scott@netsplit.com>
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <poll.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "libudev-util.h"
+#include "time-util.h"
+#include "udevadm.h"
+#include "udev-ctrl.h"
+#include "util.h"
+#include "virt.h"
+
+static usec_t arg_timeout = 120 * USEC_PER_SEC;
+static const char *arg_exists = NULL;
+
+static int help(void) {
+        printf("%s settle [OPTIONS]\n\n"
+               "Wait for pending udev events.\n\n"
+               "  -h --help                 Show this help\n"
+               "  -V --version              Show package version\n"
+               "  -t --timeout=SEC          Maximum time to wait for events\n"
+               "  -E --exit-if-exists=FILE  Stop waiting if file exists\n"
+               , program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+        static const struct option options[] = {
+                { "timeout",        required_argument, NULL, 't' },
+                { "exit-if-exists", required_argument, NULL, 'E' },
+                { "version",        no_argument,       NULL, 'V' },
+                { "help",           no_argument,       NULL, 'h' },
+                { "seq-start",      required_argument, NULL, 's' }, /* removed */
+                { "seq-end",        required_argument, NULL, 'e' }, /* removed */
+                { "quiet",          no_argument,       NULL, 'q' }, /* removed */
+                {}
+        };
+
+        int c, r;
+
+        while ((c = getopt_long(argc, argv, "t:E:Vhs:e:q", options, NULL)) >= 0) {
+                switch (c) {
+                case 't':
+                        r = parse_sec(optarg, &arg_timeout);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to parse timeout value '%s': %m", optarg);
+                        break;
+                case 'E':
+                        arg_exists = optarg;
+                        break;
+                case 'V':
+                        return print_version();
+                case 'h':
+                        return help();
+                case 's':
+                case 'e':
+                case 'q':
+                        return log_info_errno(SYNTHETIC_ERRNO(EINVAL),
+                                              "Option -%c no longer supported.",
+                                              c);
+                case '?':
+                        return -EINVAL;
+                default:
+                        assert_not_reached("Unknown option.");
+                }
+        }
+
+        return 1;
+}
+
+int settle_main(int argc, char *argv[], void *userdata) {
+        _cleanup_(udev_queue_unrefp) struct udev_queue *queue = NULL;
+        struct pollfd pfd;
+        usec_t deadline;
+        int r;
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r;
+
+        if (running_in_chroot() > 0) {
+                log_info("Running in chroot, ignoring request.");
+                return 0;
+        }
+
+        deadline = now(CLOCK_MONOTONIC) + arg_timeout;
+
+        /* guarantee that the udev daemon isn't pre-processing */
+        if (getuid() == 0) {
+                _cleanup_(udev_ctrl_unrefp) struct udev_ctrl *uctrl = NULL;
+
+                uctrl = udev_ctrl_new();
+                if (uctrl) {
+                        r = udev_ctrl_send_ping(uctrl, MAX(5 * USEC_PER_SEC, arg_timeout));
+                        if (r < 0) {
+                                log_debug_errno(r, "Failed to connect to udev daemon: %m");
+                                return 0;
+                        }
+                }
+        }
+
+        queue = udev_queue_new(NULL);
+        if (!queue)
+                return log_error_errno(errno, "Failed to get udev queue: %m");
+
+        r = udev_queue_get_fd(queue);
+        if (r < 0) {
+                log_debug_errno(r, "Queue is empty, nothing to watch.");
+                return 0;
+        }
+
+        pfd = (struct pollfd) {
+                .events = POLLIN,
+                .fd = r,
+        };
+
+        for (;;) {
+                if (arg_exists && access(arg_exists, F_OK) >= 0)
+                        return 0;
+
+                /* exit if queue is empty */
+                if (udev_queue_get_queue_is_empty(queue))
+                        return 0;
+
+                if (now(CLOCK_MONOTONIC) >= deadline)
+                        return -ETIMEDOUT;
+
+                /* wake up when queue becomes empty */
+                if (poll(&pfd, 1, MSEC_PER_SEC) > 0 && pfd.revents & POLLIN) {
+                        r = udev_queue_flush(queue);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to flush queue: %m");
+                }
+        }
+}