src/udev/udevadm-monitor.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #include <errno.h>
   4 #include <getopt.h>
   5
   6 #include "sd-device.h"
   7 #include "sd-event.h"
   8
   9 #include "alloc-util.h"
  10 #include "device-monitor-private.h"
  11 #include "device-private.h"
  12 #include "device-util.h"
  13 #include "fd-util.h"
  14 #include "format-util.h"
  15 #include "hashmap.h"
  16 #include "set.h"
  17 #include "signal-util.h"
  18 #include "string-util.h"
  19 #include "udevadm.h"
  20 #include "virt.h"
  21 #include "time-util.h"
  22
  23 static bool arg_show_property = false;
  24 static bool arg_print_kernel = false;
  25 static bool arg_print_udev = false;
  26 static Set *arg_tag_filter = NULL;
  27 static Hashmap *arg_subsystem_filter = NULL;
  28
  29 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
  30         DeviceAction action = _DEVICE_ACTION_INVALID;
  31         const char *devpath = NULL, *subsystem = NULL;
  32         MonitorNetlinkGroup group = PTR_TO_INT(userdata);
  33         struct timespec ts;
  34
  35         assert(device);
  36         assert(IN_SET(group, MONITOR_GROUP_UDEV, MONITOR_GROUP_KERNEL));
  37
  38         (void) device_get_action(device, &action);
  39         (void) sd_device_get_devpath(device, &devpath);
  40         (void) sd_device_get_subsystem(device, &subsystem);
  41
  42         assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
  43
  44         printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n",
  45                group == MONITOR_GROUP_UDEV ? "UDEV" : "KERNEL",
  46                ts.tv_sec, (nsec_t)ts.tv_nsec/1000,
  47                strna(device_action_to_string(action)),
  48                devpath, subsystem);
  49
  50         if (arg_show_property) {
  51                 const char *key, *value;
  52
  53                 FOREACH_DEVICE_PROPERTY(device, key, value)
  54                         printf("%s=%s\n", key, value);
  55
  56                 printf("\n");
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
  63         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
  64         const char *subsystem, *devtype, *tag;
  65         Iterator i;
  66         int r;
  67
  68         r = device_monitor_new_full(&monitor, sender, -1);
  69         if (r < 0)
  70                 return log_error_errno(r, "Failed to create netlink socket: %m");
  71
  72         (void) sd_device_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
  73
  74         r = sd_device_monitor_attach_event(monitor, event);
  75         if (r < 0)
  76                 return log_error_errno(r, "Failed to attach event: %m");
  77
  78         HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) {
  79                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
  80                 if (r < 0)
  81                         return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
  82                                                subsystem, devtype ? "/" : "", strempty(devtype));
  83         }
  84
  85         SET_FOREACH(tag, arg_tag_filter, i) {
  86                 r = sd_device_monitor_filter_add_match_tag(monitor, tag);
  87                 if (r < 0)
  88                         return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
  89         }
  90
  91         r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
  92         if (r < 0)
  93                 return log_error_errno(r, "Failed to start device monitor: %m");
  94
  95         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor),
  96                                                sender == MONITOR_GROUP_UDEV ? "device-monitor-udev" : "device-monitor-kernel");
  97
  98         *ret = TAKE_PTR(monitor);
  99         return 0;
 100 }
 101
 102 static int help(void) {
 103         printf("%s monitor [OPTIONS]\n\n"
 104                "Listen to kernel and udev events.\n\n"
 105                "  -h --help                                Show this help\n"
 106                "  -V --version                             Show package version\n"
 107                "  -p --property                            Print the event properties\n"
 108                "  -k --kernel                              Print kernel uevents\n"
 109                "  -u --udev                                Print udev events\n"
 110                "  -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n"
 111                "  -t --tag-match=TAG                       Filter events by tag\n"
 112                , program_invocation_short_name);
 113
 114         return 0;
 115 }
 116
 117 static int parse_argv(int argc, char *argv[]) {
 118         static const struct option options[] = {
 119                 { "property",        no_argument,       NULL, 'p' },
 120                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
 121                 { "kernel",          no_argument,       NULL, 'k' },
 122                 { "udev",            no_argument,       NULL, 'u' },
 123                 { "subsystem-match", required_argument, NULL, 's' },
 124                 { "tag-match",       required_argument, NULL, 't' },
 125                 { "version",         no_argument,       NULL, 'V' },
 126                 { "help",            no_argument,       NULL, 'h' },
 127                 {}
 128         };
 129
 130         int r, c;
 131
 132         while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0)
 133                 switch (c) {
 134                 case 'p':
 135                 case 'e':
 136                         arg_show_property = true;
 137                         break;
 138                 case 'k':
 139                         arg_print_kernel = true;
 140                         break;
 141                 case 'u':
 142                         arg_print_udev = true;
 143                         break;
 144                 case 's': {
 145                         _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
 146                         const char *slash;
 147
 148                         slash = strchr(optarg, '/');
 149                         if (slash) {
 150                                 devtype = strdup(slash + 1);
 151                                 if (!devtype)
 152                                         return -ENOMEM;
 153
 154                                 subsystem = strndup(optarg, slash - optarg);
 155                         } else
 156                                 subsystem = strdup(optarg);
 157
 158                         if (!subsystem)
 159                                 return -ENOMEM;
 160
 161                         r = hashmap_ensure_allocated(&arg_subsystem_filter, NULL);
 162                         if (r < 0)
 163                                 return r;
 164
 165                         r = hashmap_put(arg_subsystem_filter, subsystem, devtype);
 166                         if (r < 0)
 167                                 return r;
 168
 169                         subsystem = devtype = NULL;
 170                         break;
 171                 }
 172                 case 't':
 173                         /* optarg is stored in argv[], so we don't need to copy it */
 174                         r = set_ensure_put(&arg_tag_filter, &string_hash_ops, optarg);
 175                         if (r < 0)
 176                                 return r;
 177                         break;
 178
 179                 case 'V':
 180                         return print_version();
 181                 case 'h':
 182                         return help();
 183                 case '?':
 184                         return -EINVAL;
 185                 default:
 186                         assert_not_reached("Unknown option.");
 187                 }
 188
 189         if (!arg_print_kernel && !arg_print_udev) {
 190                 arg_print_kernel = true;
 191                 arg_print_udev = true;
 192         }
 193
 194         return 1;
 195 }
 196
 197 int monitor_main(int argc, char *argv[], void *userdata) {
 198         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
 199         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 200         int r;
 201
 202         r = parse_argv(argc, argv);
 203         if (r <= 0)
 204                 goto finalize;
 205
 206         if (running_in_chroot() > 0) {
 207                 log_info("Running in chroot, ignoring request.");
 208                 return 0;
 209         }
 210
 211         /* Callers are expecting to see events as they happen: Line buffering */
 212         setlinebuf(stdout);
 213
 214         r = sd_event_default(&event);
 215         if (r < 0) {
 216                 log_error_errno(r, "Failed to initialize event: %m");
 217                 goto finalize;
 218         }
 219
 220         assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
 221         (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
 222         (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
 223
 224         printf("monitor will print the received events for:\n");
 225         if (arg_print_udev) {
 226                 r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
 227                 if (r < 0)
 228                         goto finalize;
 229
 230                 printf("UDEV - the event which udev sends out after rule processing\n");
 231         }
 232
 233         if (arg_print_kernel) {
 234                 r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
 235                 if (r < 0)
 236                         goto finalize;
 237
 238                 printf("KERNEL - the kernel uevent\n");
 239         }
 240         printf("\n");
 241
 242         r = sd_event_loop(event);
 243         if (r < 0) {
 244                 log_error_errno(r, "Failed to run event loop: %m");
 245                 goto finalize;
 246         }
 247
 248         r = 0;
 249
 250 finalize:
 251         hashmap_free_free_free(arg_subsystem_filter);
 252         set_free(arg_tag_filter);
 253
 254         return r;
 255 }