/* SPDX-License-Identifier: GPL-2.0-or-later */

#include "sd-device.h"
#include "sd-event.h"

#include "alloc-util.h"
#include "device-monitor-private.h"
#include "device-private.h"
#include "device-util.h"
#include "format-table.h"
#include "format-util.h"
#include "hashmap.h"
#include "help-util.h"
#include "options.h"
#include "set.h"
#include "static-destruct.h"
#include "string-util.h"
#include "time-util.h"
#include "udevadm.h"
#include "virt.h"

static bool arg_show_property = false;
static bool arg_print_kernel = false;
static bool arg_print_udev = false;
static Set *arg_tag_filter = NULL;
static Hashmap *arg_subsystem_filter = NULL;

STATIC_DESTRUCTOR_REGISTER(arg_tag_filter, set_freep);
STATIC_DESTRUCTOR_REGISTER(arg_subsystem_filter, hashmap_freep);

static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
        sd_device_action_t action = _SD_DEVICE_ACTION_INVALID;
        const char *devpath = NULL, *subsystem = NULL;
        MonitorNetlinkGroup group = PTR_TO_INT(userdata);
        struct timespec ts;

        assert(device);
        assert(IN_SET(group, MONITOR_GROUP_UDEV, MONITOR_GROUP_KERNEL));

        (void) sd_device_get_action(device, &action);
        (void) sd_device_get_devpath(device, &devpath);
        (void) sd_device_get_subsystem(device, &subsystem);

        assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);

        printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n",
               group == MONITOR_GROUP_UDEV ? "UDEV" : "KERNEL",
               ts.tv_sec, (nsec_t)ts.tv_nsec/1000,
               strna(device_action_to_string(action)),
               devpath, subsystem);

        if (arg_show_property) {
                FOREACH_DEVICE_PROPERTY(device, key, value)
                        printf("%s=%s\n", key, value);

                printf("\n");
        }

        fflush(stdout);

        return 0;
}

static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
        _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
        const char *subsystem, *devtype, *tag;
        int r;

        assert(ret);

        r = device_monitor_new_full(&monitor, sender, -EBADF);
        if (r < 0)
                return log_error_errno(r, "Failed to create netlink socket: %m");

        r = sd_device_monitor_attach_event(monitor, event);
        if (r < 0)
                return log_error_errno(r, "Failed to attach event: %m");

        HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter) {
                r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
                if (r < 0)
                        return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
                                               subsystem, devtype ? "/" : "", strempty(devtype));
        }

        SET_FOREACH(tag, arg_tag_filter) {
                r = sd_device_monitor_filter_add_match_tag(monitor, tag);
                if (r < 0)
                        return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
        }

        r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
        if (r < 0)
                return log_error_errno(r, "Failed to start device monitor: %m");

        (void) sd_device_monitor_set_description(monitor, sender == MONITOR_GROUP_UDEV ? "udev" : "kernel");

        *ret = TAKE_PTR(monitor);
        return 0;
}

static int help(void) {
        _cleanup_(table_unrefp) Table *options = NULL;
        int r;

        r = option_parser_get_help_table_ns("udevadm-monitor", &options);
        if (r < 0)
                return r;

        help_cmdline("monitor [OPTIONS]");
        help_abstract("Listen to kernel and udev events.");
        help_section("Options");
        r = table_print_or_warn(options);
        if (r < 0)
                return r;

        help_man_page_reference("udevadm", "8");
        return 0;
}

static int parse_argv(int argc, char *argv[]) {
        int r;

        assert(argc >= 0);
        assert(argv);

        OptionParser opts = { argc, argv, .namespace = "udevadm-monitor" };

        FOREACH_OPTION_OR_RETURN(c, &opts)
                switch (c) {

                OPTION_NAMESPACE("udevadm-monitor"): {}

                OPTION_COMMON_HELP:
                        return help();

                OPTION('V', "version", NULL, "Show package version"):
                        return print_version();

                OPTION('e', "environment", NULL, /* help= */ NULL): {} /* hidden alias for -p */
                OPTION('p', "property", NULL, "Print the event properties"):
                        arg_show_property = true;
                        break;

                OPTION('k', "kernel", NULL, "Print kernel uevents"):
                        arg_print_kernel = true;
                        break;

                OPTION('u', "udev", NULL, "Print udev events"):
                        arg_print_udev = true;
                        break;

                OPTION('s', "subsystem-match", "SUBSYSTEM[/DEVTYPE]",
                       "Filter events by subsystem"): {
                        _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
                        const char *slash;

                        slash = strchr(opts.arg, '/');
                        if (slash) {
                                devtype = strdup(slash + 1);
                                if (!devtype)
                                        return log_oom();

                                subsystem = strndup(opts.arg, slash - opts.arg);
                        } else
                                subsystem = strdup(opts.arg);

                        if (!subsystem)
                                return log_oom();

                        r = hashmap_ensure_put(&arg_subsystem_filter, &trivial_hash_ops_free_free, subsystem, devtype);
                        if (r < 0)
                                return log_oom();

                        TAKE_PTR(subsystem);
                        TAKE_PTR(devtype);
                        break;
                }

                OPTION('t', "tag-match", "TAG", "Filter events by tag"):
                        r = set_put_strdup(&arg_tag_filter, opts.arg);
                        if (r < 0)
                                return log_oom();
                        break;
                }

        if (!arg_print_kernel && !arg_print_udev) {
                arg_print_kernel = true;
                arg_print_udev = true;
        }

        return 1;
}

int verb_monitor_main(int argc, char *argv[], uintptr_t _data, void *userdata) {
        _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
        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;
        }

        /* Callers are expecting to see events as they happen: Line buffering */
        setlinebuf(stdout);

        r = sd_event_default(&event);
        if (r < 0)
                return log_error_errno(r, "Failed to initialize event: %m");

        r = sd_event_set_signal_exit(event, true);
        if (r < 0)
                return log_error_errno(r, "Failed to install SIGINT/SIGTERM handling: %m");

        printf("monitor will print the received events for:\n");
        if (arg_print_udev) {
                r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
                if (r < 0)
                        return r;

                printf("UDEV - the event which udev sends out after rule processing\n");
        }

        if (arg_print_kernel) {
                r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
                if (r < 0)
                        return r;

                printf("KERNEL - the kernel uevent\n");
        }
        printf("\n");

        r = sd_event_loop(event);
        if (r < 0)
                return log_error_errno(r, "Failed to run event loop: %m");

        return 0;
}
