src/udev/udevadm-monitor.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   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         sd_device_action_t action = _SD_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) sd_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                 FOREACH_DEVICE_PROPERTY(device, key, value)
  52                         printf("%s=%s\n", key, value);
  53
  54                 printf("\n");
  55         }
  56
  57         return 0;
  58 }
  59
  60 static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
  61         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
  62         const char *subsystem, *devtype, *tag;
  63         int r;
  64
  65         r = device_monitor_new_full(&monitor, sender, -1);
  66         if (r < 0)
  67                 return log_error_errno(r, "Failed to create netlink socket: %m");
  68
  69         r = sd_device_monitor_attach_event(monitor, event);
  70         if (r < 0)
  71                 return log_error_errno(r, "Failed to attach event: %m");
  72
  73         HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter) {
  74                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
  75                 if (r < 0)
  76                         return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
  77                                                subsystem, devtype ? "/" : "", strempty(devtype));
  78         }
  79
  80         SET_FOREACH(tag, arg_tag_filter) {
  81                 r = sd_device_monitor_filter_add_match_tag(monitor, tag);
  82                 if (r < 0)
  83                         return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
  84         }
  85
  86         r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
  87         if (r < 0)
  88                 return log_error_errno(r, "Failed to start device monitor: %m");
  89
  90         (void) sd_device_monitor_set_description(monitor, sender == MONITOR_GROUP_UDEV ? "udev" : "kernel");
  91
  92         *ret = TAKE_PTR(monitor);
  93         return 0;
  94 }
  95
  96 static int help(void) {
  97         printf("%s monitor [OPTIONS]\n\n"
  98                "Listen to kernel and udev events.\n\n"
  99                "  -h --help                                Show this help\n"
 100                "  -V --version                             Show package version\n"
 101                "  -p --property                            Print the event properties\n"
 102                "  -k --kernel                              Print kernel uevents\n"
 103                "  -u --udev                                Print udev events\n"
 104                "  -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n"
 105                "  -t --tag-match=TAG                       Filter events by tag\n",
 106                program_invocation_short_name);
 107
 108         return 0;
 109 }
 110
 111 static int parse_argv(int argc, char *argv[]) {
 112         static const struct option options[] = {
 113                 { "property",        no_argument,       NULL, 'p' },
 114                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
 115                 { "kernel",          no_argument,       NULL, 'k' },
 116                 { "udev",            no_argument,       NULL, 'u' },
 117                 { "subsystem-match", required_argument, NULL, 's' },
 118                 { "tag-match",       required_argument, NULL, 't' },
 119                 { "version",         no_argument,       NULL, 'V' },
 120                 { "help",            no_argument,       NULL, 'h' },
 121                 {}
 122         };
 123
 124         int r, c;
 125
 126         while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0)
 127                 switch (c) {
 128                 case 'p':
 129                 case 'e':
 130                         arg_show_property = true;
 131                         break;
 132                 case 'k':
 133                         arg_print_kernel = true;
 134                         break;
 135                 case 'u':
 136                         arg_print_udev = true;
 137                         break;
 138                 case 's': {
 139                         _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
 140                         const char *slash;
 141
 142                         slash = strchr(optarg, '/');
 143                         if (slash) {
 144                                 devtype = strdup(slash + 1);
 145                                 if (!devtype)
 146                                         return -ENOMEM;
 147
 148                                 subsystem = strndup(optarg, slash - optarg);
 149                         } else
 150                                 subsystem = strdup(optarg);
 151
 152                         if (!subsystem)
 153                                 return -ENOMEM;
 154
 155                         r = hashmap_ensure_put(&arg_subsystem_filter, NULL, subsystem, devtype);
 156                         if (r < 0)
 157                                 return r;
 158
 159                         TAKE_PTR(subsystem);
 160                         TAKE_PTR(devtype);
 161                         break;
 162                 }
 163                 case 't':
 164                         /* optarg is stored in argv[], so we don't need to copy it */
 165                         r = set_ensure_put(&arg_tag_filter, &string_hash_ops, optarg);
 166                         if (r < 0)
 167                                 return r;
 168                         break;
 169
 170                 case 'V':
 171                         return print_version();
 172                 case 'h':
 173                         return help();
 174                 case '?':
 175                         return -EINVAL;
 176                 default:
 177                         assert_not_reached();
 178                 }
 179
 180         if (!arg_print_kernel && !arg_print_udev) {
 181                 arg_print_kernel = true;
 182                 arg_print_udev = true;
 183         }
 184
 185         return 1;
 186 }
 187
 188 int monitor_main(int argc, char *argv[], void *userdata) {
 189         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
 190         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 191         int r;
 192
 193         r = parse_argv(argc, argv);
 194         if (r <= 0)
 195                 goto finalize;
 196
 197         if (running_in_chroot() > 0) {
 198                 log_info("Running in chroot, ignoring request.");
 199                 return 0;
 200         }
 201
 202         /* Callers are expecting to see events as they happen: Line buffering */
 203         setlinebuf(stdout);
 204
 205         r = sd_event_default(&event);
 206         if (r < 0) {
 207                 log_error_errno(r, "Failed to initialize event: %m");
 208                 goto finalize;
 209         }
 210
 211         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
 212         (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
 213         (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
 214
 215         printf("monitor will print the received events for:\n");
 216         if (arg_print_udev) {
 217                 r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
 218                 if (r < 0)
 219                         goto finalize;
 220
 221                 printf("UDEV - the event which udev sends out after rule processing\n");
 222         }
 223
 224         if (arg_print_kernel) {
 225                 r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
 226                 if (r < 0)
 227                         goto finalize;
 228
 229                 printf("KERNEL - the kernel uevent\n");
 230         }
 231         printf("\n");
 232
 233         r = sd_event_loop(event);
 234         if (r < 0) {
 235                 log_error_errno(r, "Failed to run event loop: %m");
 236                 goto finalize;
 237         }
 238
 239         r = 0;
 240
 241 finalize:
 242         hashmap_free_free_free(arg_subsystem_filter);
 243         set_free(arg_tag_filter);
 244
 245         return r;
 246 }