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
  21 static bool arg_show_property = false;
  22 static bool arg_print_kernel = false;
  23 static bool arg_print_udev = false;
  24 static Set *arg_tag_filter = NULL;
  25 static Hashmap *arg_subsystem_filter = NULL;
  26
  27 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
  28         const char *action = NULL, *devpath = NULL, *subsystem = NULL;
  29         MonitorNetlinkGroup group = PTR_TO_INT(userdata);
  30         struct timespec ts;
  31
  32         assert(device);
  33         assert(IN_SET(group, MONITOR_GROUP_UDEV, MONITOR_GROUP_KERNEL));
  34
  35         (void) sd_device_get_property_value(device, "ACTION", &action);
  36         (void) sd_device_get_devpath(device, &devpath);
  37         (void) sd_device_get_subsystem(device, &subsystem);
  38
  39         assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
  40
  41         printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n",
  42                group == MONITOR_GROUP_UDEV ? "UDEV" : "KERNEL",
  43                ts.tv_sec, (nsec_t)ts.tv_nsec/1000,
  44                action, devpath, subsystem);
  45
  46         if (arg_show_property) {
  47                 const char *key, *value;
  48
  49                 FOREACH_DEVICE_PROPERTY(device, key, value)
  50                         printf("%s=%s\n", key, value);
  51
  52                 printf("\n");
  53         }
  54
  55         return 0;
  56 }
  57
  58 static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
  59         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
  60         const char *subsystem, *devtype, *tag;
  61         Iterator i;
  62         int r;
  63
  64         r = device_monitor_new_full(&monitor, sender, -1);
  65         if (r < 0)
  66                 return log_error_errno(r, "Failed to create netlink socket: %m");
  67
  68         (void) sd_device_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
  69
  70         r = sd_device_monitor_attach_event(monitor, event);
  71         if (r < 0)
  72                 return log_error_errno(r, "Failed to attach event: %m");
  73
  74         HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) {
  75                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
  76                 if (r < 0)
  77                         return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
  78                                                subsystem, devtype ? "/" : "", strempty(devtype));
  79         }
  80
  81         SET_FOREACH(tag, arg_tag_filter, i) {
  82                 r = sd_device_monitor_filter_add_match_tag(monitor, tag);
  83                 if (r < 0)
  84                         return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
  85         }
  86
  87         r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
  88         if (r < 0)
  89                 return log_error_errno(r, "Failed to start device monitor: %m");
  90
  91         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor),
  92                                                sender == MONITOR_GROUP_UDEV ? "device-monitor-udev" : "device-monitor-kernel");
  93
  94         *ret = TAKE_PTR(monitor);
  95         return 0;
  96 }
  97
  98 static int help(void) {
  99         printf("%s monitor [OPTIONS]\n\n"
 100                "Listen to kernel and udev events.\n\n"
 101                "  -h --help                                Show this help\n"
 102                "  -V --version                             Show package version\n"
 103                "  -p --property                            Print the event properties\n"
 104                "  -k --kernel                              Print kernel uevents\n"
 105                "  -u --udev                                Print udev events\n"
 106                "  -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n"
 107                "  -t --tag-match=TAG                       Filter events by tag\n"
 108                , program_invocation_short_name);
 109
 110         return 0;
 111 }
 112
 113 static int parse_argv(int argc, char *argv[]) {
 114         static const struct option options[] = {
 115                 { "property",        no_argument,       NULL, 'p' },
 116                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
 117                 { "kernel",          no_argument,       NULL, 'k' },
 118                 { "udev",            no_argument,       NULL, 'u' },
 119                 { "subsystem-match", required_argument, NULL, 's' },
 120                 { "tag-match",       required_argument, NULL, 't' },
 121                 { "version",         no_argument,       NULL, 'V' },
 122                 { "help",            no_argument,       NULL, 'h' },
 123                 {}
 124         };
 125
 126         int r, c;
 127
 128         while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0)
 129                 switch (c) {
 130                 case 'p':
 131                 case 'e':
 132                         arg_show_property = true;
 133                         break;
 134                 case 'k':
 135                         arg_print_kernel = true;
 136                         break;
 137                 case 'u':
 138                         arg_print_udev = true;
 139                         break;
 140                 case 's': {
 141                         _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
 142                         const char *slash;
 143
 144                         slash = strchr(optarg, '/');
 145                         if (slash) {
 146                                 devtype = strdup(devtype + 1);
 147                                 if (!devtype)
 148                                         return -ENOMEM;
 149
 150                                 subsystem = strndup(optarg, devtype - optarg);
 151                         } else
 152                                 subsystem = strdup(optarg);
 153
 154                         if (!subsystem)
 155                                 return -ENOMEM;
 156
 157                         r = hashmap_ensure_allocated(&arg_subsystem_filter, NULL);
 158                         if (r < 0)
 159                                 return r;
 160
 161                         r = hashmap_put(arg_subsystem_filter, subsystem, devtype);
 162                         if (r < 0)
 163                                 return r;
 164
 165                         subsystem = devtype = NULL;
 166                         break;
 167                 }
 168                 case 't': {
 169                         _cleanup_free_ char *tag = NULL;
 170
 171                         r = set_ensure_allocated(&arg_tag_filter, &string_hash_ops);
 172                         if (r < 0)
 173                                 return r;
 174
 175                         tag = strdup(optarg);
 176                         if (!tag)
 177                                 return -ENOMEM;
 178
 179                         r = set_put(arg_tag_filter, tag);
 180                         if (r < 0)
 181                                 return r;
 182
 183                         tag = NULL;
 184                         break;
 185                 }
 186                 case 'V':
 187                         return print_version();
 188                 case 'h':
 189                         return help();
 190                 case '?':
 191                         return -EINVAL;
 192                 default:
 193                         assert_not_reached("Unknown option.");
 194                 }
 195
 196         if (!arg_print_kernel && !arg_print_udev) {
 197                 arg_print_kernel = true;
 198                 arg_print_udev = true;
 199         }
 200
 201         return 1;
 202 }
 203
 204 int monitor_main(int argc, char *argv[], void *userdata) {
 205         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
 206         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 207         int r;
 208
 209         r = parse_argv(argc, argv);
 210         if (r <= 0)
 211                 goto finalize;
 212
 213         /* Callers are expecting to see events as they happen: Line buffering */
 214         setlinebuf(stdout);
 215
 216         r = sd_event_default(&event);
 217         if (r < 0) {
 218                 log_error_errno(r, "Failed to initialize event: %m");
 219                 goto finalize;
 220         }
 221
 222         assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
 223         (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
 224         (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
 225
 226         printf("monitor will print the received events for:\n");
 227         if (arg_print_udev) {
 228                 r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
 229                 if (r < 0)
 230                         goto finalize;
 231
 232                 printf("UDEV - the event which udev sends out after rule processing\n");
 233         }
 234
 235         if (arg_print_kernel) {
 236                 r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
 237                 if (r < 0)
 238                         goto finalize;
 239
 240                 printf("KERNEL - the kernel uevent\n");
 241         }
 242         printf("\n");
 243
 244         r = sd_event_loop(event);
 245         if (r < 0) {
 246                 log_error_errno(r, "Failed to run event loop: %m");
 247                 goto finalize;
 248         }
 249
 250         r = 0;
 251
 252 finalize:
 253         hashmap_free_free_free(arg_subsystem_filter);
 254         set_free_free(arg_tag_filter);
 255
 256         return r;
 257 }