src/udev/udevadm-monitor.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #include <errno.h>
   4 #include <getopt.h>
   5 #include <signal.h>
   6
   7 #include "sd-device.h"
   8 #include "sd-event.h"
   9
  10 #include "alloc-util.h"
  11 #include "device-monitor-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
  22 static bool arg_show_property = false;
  23 static bool arg_print_kernel = false;
  24 static bool arg_print_udev = false;
  25 static Set *arg_tag_filter = NULL;
  26 static Hashmap *arg_subsystem_filter = NULL;
  27
  28 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
  29         const char *action = NULL, *devpath = NULL, *subsystem = NULL;
  30         MonitorNetlinkGroup group = PTR_TO_INT(userdata);
  31         struct timespec ts;
  32
  33         assert(device);
  34         assert(IN_SET(group, MONITOR_GROUP_UDEV, MONITOR_GROUP_KERNEL));
  35
  36         (void) sd_device_get_property_value(device, "ACTION", &action);
  37         (void) sd_device_get_devpath(device, &devpath);
  38         (void) sd_device_get_subsystem(device, &subsystem);
  39
  40         assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
  41
  42         printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n",
  43                group == MONITOR_GROUP_UDEV ? "UDEV" : "KERNEL",
  44                ts.tv_sec, (nsec_t)ts.tv_nsec/1000,
  45                action, devpath, subsystem);
  46
  47         if (arg_show_property) {
  48                 const char *key, *value;
  49
  50                 FOREACH_DEVICE_PROPERTY(device, key, value)
  51                         printf("%s=%s\n", key, value);
  52
  53                 printf("\n");
  54         }
  55
  56         return 0;
  57 }
  58
  59 static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
  60         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
  61         const char *subsystem, *devtype, *tag;
  62         Iterator i;
  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         (void) sd_device_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
  70
  71         r = sd_device_monitor_attach_event(monitor, event);
  72         if (r < 0)
  73                 return log_error_errno(r, "Failed to attach event: %m");
  74
  75         HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) {
  76                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
  77                 if (r < 0)
  78                         return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
  79                                                subsystem, devtype ? "/" : "", strempty(devtype));
  80         }
  81
  82         SET_FOREACH(tag, arg_tag_filter, i) {
  83                 r = sd_device_monitor_filter_add_match_tag(monitor, tag);
  84                 if (r < 0)
  85                         return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
  86         }
  87
  88         r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
  89         if (r < 0)
  90                 return log_error_errno(r, "Failed to start device monitor: %m");
  91
  92         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor),
  93                                                sender == MONITOR_GROUP_UDEV ? "device-monitor-udev" : "device-monitor-kernel");
  94
  95         *ret = TAKE_PTR(monitor);
  96         return 0;
  97 }
  98
  99 static int help(void) {
 100         printf("%s monitor [OPTIONS]\n\n"
 101                "Listen to kernel and udev events.\n\n"
 102                "  -h --help                                Show this help\n"
 103                "  -V --version                             Show package version\n"
 104                "  -p --property                            Print the event properties\n"
 105                "  -k --kernel                              Print kernel uevents\n"
 106                "  -u --udev                                Print udev events\n"
 107                "  -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n"
 108                "  -t --tag-match=TAG                       Filter events by tag\n"
 109                , program_invocation_short_name);
 110
 111         return 0;
 112 }
 113
 114 static int parse_argv(int argc, char *argv[]) {
 115         static const struct option options[] = {
 116                 { "property",        no_argument,       NULL, 'p' },
 117                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
 118                 { "kernel",          no_argument,       NULL, 'k' },
 119                 { "udev",            no_argument,       NULL, 'u' },
 120                 { "subsystem-match", required_argument, NULL, 's' },
 121                 { "tag-match",       required_argument, NULL, 't' },
 122                 { "version",         no_argument,       NULL, 'V' },
 123                 { "help",            no_argument,       NULL, 'h' },
 124                 {}
 125         };
 126
 127         int r, c;
 128
 129         while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0)
 130                 switch (c) {
 131                 case 'p':
 132                 case 'e':
 133                         arg_show_property = true;
 134                         break;
 135                 case 'k':
 136                         arg_print_kernel = true;
 137                         break;
 138                 case 'u':
 139                         arg_print_udev = true;
 140                         break;
 141                 case 's': {
 142                         _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
 143                         const char *slash;
 144
 145                         slash = strchr(optarg, '/');
 146                         if (slash) {
 147                                 devtype = strdup(slash + 1);
 148                                 if (!devtype)
 149                                         return -ENOMEM;
 150
 151                                 subsystem = strndup(optarg, slash - optarg);
 152                         } else
 153                                 subsystem = strdup(optarg);
 154
 155                         if (!subsystem)
 156                                 return -ENOMEM;
 157
 158                         r = hashmap_ensure_allocated(&arg_subsystem_filter, NULL);
 159                         if (r < 0)
 160                                 return r;
 161
 162                         r = hashmap_put(arg_subsystem_filter, subsystem, devtype);
 163                         if (r < 0)
 164                                 return r;
 165
 166                         subsystem = devtype = NULL;
 167                         break;
 168                 }
 169                 case 't': {
 170                         _cleanup_free_ char *tag = NULL;
 171
 172                         r = set_ensure_allocated(&arg_tag_filter, &string_hash_ops);
 173                         if (r < 0)
 174                                 return r;
 175
 176                         tag = strdup(optarg);
 177                         if (!tag)
 178                                 return -ENOMEM;
 179
 180                         r = set_put(arg_tag_filter, tag);
 181                         if (r < 0)
 182                                 return r;
 183
 184                         tag = NULL;
 185                         break;
 186                 }
 187                 case 'V':
 188                         return print_version();
 189                 case 'h':
 190                         return help();
 191                 case '?':
 192                         return -EINVAL;
 193                 default:
 194                         assert_not_reached("Unknown option.");
 195                 }
 196
 197         if (!arg_print_kernel && !arg_print_udev) {
 198                 arg_print_kernel = true;
 199                 arg_print_udev = true;
 200         }
 201
 202         return 1;
 203 }
 204
 205 int monitor_main(int argc, char *argv[], void *userdata) {
 206         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
 207         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 208         int r;
 209
 210         r = parse_argv(argc, argv);
 211         if (r <= 0)
 212                 goto finalize;
 213
 214         if (running_in_chroot() > 0) {
 215                 log_info("Running in chroot, ignoring request.");
 216                 return 0;
 217         }
 218
 219         /* Callers are expecting to see events as they happen: Line buffering */
 220         setlinebuf(stdout);
 221
 222         r = sd_event_default(&event);
 223         if (r < 0) {
 224                 log_error_errno(r, "Failed to initialize event: %m");
 225                 goto finalize;
 226         }
 227
 228         assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
 229         (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
 230         (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
 231
 232         printf("monitor will print the received events for:\n");
 233         if (arg_print_udev) {
 234                 r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
 235                 if (r < 0)
 236                         goto finalize;
 237
 238                 printf("UDEV - the event which udev sends out after rule processing\n");
 239         }
 240
 241         if (arg_print_kernel) {
 242                 r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
 243                 if (r < 0)
 244                         goto finalize;
 245
 246                 printf("KERNEL - the kernel uevent\n");
 247         }
 248         printf("\n");
 249
 250         r = sd_event_loop(event);
 251         if (r < 0) {
 252                 log_error_errno(r, "Failed to run event loop: %m");
 253                 goto finalize;
 254         }
 255
 256         r = 0;
 257
 258 finalize:
 259         hashmap_free_free_free(arg_subsystem_filter);
 260         set_free_free(arg_tag_filter);
 261
 262         return r;
 263 }