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-private.h"
  13 #include "device-util.h"
  14 #include "fd-util.h"
  15 #include "format-util.h"
  16 #include "hashmap.h"
  17 #include "set.h"
  18 #include "signal-util.h"
  19 #include "string-util.h"
  20 #include "udevadm.h"
  21 #include "virt.h"
  22 #include "time-util.h"
  23
  24 static bool arg_show_property = false;
  25 static bool arg_print_kernel = false;
  26 static bool arg_print_udev = false;
  27 static Set *arg_tag_filter = NULL;
  28 static Hashmap *arg_subsystem_filter = NULL;
  29
  30 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
  31         DeviceAction action = _DEVICE_ACTION_INVALID;
  32         const char *devpath = NULL, *subsystem = NULL;
  33         MonitorNetlinkGroup group = PTR_TO_INT(userdata);
  34         struct timespec ts;
  35
  36         assert(device);
  37         assert(IN_SET(group, MONITOR_GROUP_UDEV, MONITOR_GROUP_KERNEL));
  38
  39         (void) device_get_action(device, &action);
  40         (void) sd_device_get_devpath(device, &devpath);
  41         (void) sd_device_get_subsystem(device, &subsystem);
  42
  43         assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
  44
  45         printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n",
  46                group == MONITOR_GROUP_UDEV ? "UDEV" : "KERNEL",
  47                ts.tv_sec, (nsec_t)ts.tv_nsec/1000,
  48                strna(device_action_to_string(action)),
  49                devpath, subsystem);
  50
  51         if (arg_show_property) {
  52                 const char *key, *value;
  53
  54                 FOREACH_DEVICE_PROPERTY(device, key, value)
  55                         printf("%s=%s\n", key, value);
  56
  57                 printf("\n");
  58         }
  59
  60         return 0;
  61 }
  62
  63 static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
  64         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
  65         const char *subsystem, *devtype, *tag;
  66         Iterator i;
  67         int r;
  68
  69         r = device_monitor_new_full(&monitor, sender, -1);
  70         if (r < 0)
  71                 return log_error_errno(r, "Failed to create netlink socket: %m");
  72
  73         (void) sd_device_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
  74
  75         r = sd_device_monitor_attach_event(monitor, event);
  76         if (r < 0)
  77                 return log_error_errno(r, "Failed to attach event: %m");
  78
  79         HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) {
  80                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
  81                 if (r < 0)
  82                         return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
  83                                                subsystem, devtype ? "/" : "", strempty(devtype));
  84         }
  85
  86         SET_FOREACH(tag, arg_tag_filter, i) {
  87                 r = sd_device_monitor_filter_add_match_tag(monitor, tag);
  88                 if (r < 0)
  89                         return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag);
  90         }
  91
  92         r = sd_device_monitor_start(monitor, device_monitor_handler, INT_TO_PTR(sender));
  93         if (r < 0)
  94                 return log_error_errno(r, "Failed to start device monitor: %m");
  95
  96         (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor),
  97                                                sender == MONITOR_GROUP_UDEV ? "device-monitor-udev" : "device-monitor-kernel");
  98
  99         *ret = TAKE_PTR(monitor);
 100         return 0;
 101 }
 102
 103 static int help(void) {
 104         printf("%s monitor [OPTIONS]\n\n"
 105                "Listen to kernel and udev events.\n\n"
 106                "  -h --help                                Show this help\n"
 107                "  -V --version                             Show package version\n"
 108                "  -p --property                            Print the event properties\n"
 109                "  -k --kernel                              Print kernel uevents\n"
 110                "  -u --udev                                Print udev events\n"
 111                "  -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n"
 112                "  -t --tag-match=TAG                       Filter events by tag\n"
 113                , program_invocation_short_name);
 114
 115         return 0;
 116 }
 117
 118 static int parse_argv(int argc, char *argv[]) {
 119         static const struct option options[] = {
 120                 { "property",        no_argument,       NULL, 'p' },
 121                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
 122                 { "kernel",          no_argument,       NULL, 'k' },
 123                 { "udev",            no_argument,       NULL, 'u' },
 124                 { "subsystem-match", required_argument, NULL, 's' },
 125                 { "tag-match",       required_argument, NULL, 't' },
 126                 { "version",         no_argument,       NULL, 'V' },
 127                 { "help",            no_argument,       NULL, 'h' },
 128                 {}
 129         };
 130
 131         int r, c;
 132
 133         while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0)
 134                 switch (c) {
 135                 case 'p':
 136                 case 'e':
 137                         arg_show_property = true;
 138                         break;
 139                 case 'k':
 140                         arg_print_kernel = true;
 141                         break;
 142                 case 'u':
 143                         arg_print_udev = true;
 144                         break;
 145                 case 's': {
 146                         _cleanup_free_ char *subsystem = NULL, *devtype = NULL;
 147                         const char *slash;
 148
 149                         slash = strchr(optarg, '/');
 150                         if (slash) {
 151                                 devtype = strdup(slash + 1);
 152                                 if (!devtype)
 153                                         return -ENOMEM;
 154
 155                                 subsystem = strndup(optarg, slash - optarg);
 156                         } else
 157                                 subsystem = strdup(optarg);
 158
 159                         if (!subsystem)
 160                                 return -ENOMEM;
 161
 162                         r = hashmap_ensure_allocated(&arg_subsystem_filter, NULL);
 163                         if (r < 0)
 164                                 return r;
 165
 166                         r = hashmap_put(arg_subsystem_filter, subsystem, devtype);
 167                         if (r < 0)
 168                                 return r;
 169
 170                         subsystem = devtype = NULL;
 171                         break;
 172                 }
 173                 case 't': {
 174                         _cleanup_free_ char *tag = NULL;
 175
 176                         r = set_ensure_allocated(&arg_tag_filter, &string_hash_ops);
 177                         if (r < 0)
 178                                 return r;
 179
 180                         tag = strdup(optarg);
 181                         if (!tag)
 182                                 return -ENOMEM;
 183
 184                         r = set_put(arg_tag_filter, tag);
 185                         if (r < 0)
 186                                 return r;
 187
 188                         tag = NULL;
 189                         break;
 190                 }
 191                 case 'V':
 192                         return print_version();
 193                 case 'h':
 194                         return help();
 195                 case '?':
 196                         return -EINVAL;
 197                 default:
 198                         assert_not_reached("Unknown option.");
 199                 }
 200
 201         if (!arg_print_kernel && !arg_print_udev) {
 202                 arg_print_kernel = true;
 203                 arg_print_udev = true;
 204         }
 205
 206         return 1;
 207 }
 208
 209 int monitor_main(int argc, char *argv[], void *userdata) {
 210         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *kernel_monitor = NULL, *udev_monitor = NULL;
 211         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 212         int r;
 213
 214         r = parse_argv(argc, argv);
 215         if (r <= 0)
 216                 goto finalize;
 217
 218         if (running_in_chroot() > 0) {
 219                 log_info("Running in chroot, ignoring request.");
 220                 return 0;
 221         }
 222
 223         /* Callers are expecting to see events as they happen: Line buffering */
 224         setlinebuf(stdout);
 225
 226         r = sd_event_default(&event);
 227         if (r < 0) {
 228                 log_error_errno(r, "Failed to initialize event: %m");
 229                 goto finalize;
 230         }
 231
 232         assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
 233         (void) sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
 234         (void) sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
 235
 236         printf("monitor will print the received events for:\n");
 237         if (arg_print_udev) {
 238                 r = setup_monitor(MONITOR_GROUP_UDEV, event, &udev_monitor);
 239                 if (r < 0)
 240                         goto finalize;
 241
 242                 printf("UDEV - the event which udev sends out after rule processing\n");
 243         }
 244
 245         if (arg_print_kernel) {
 246                 r = setup_monitor(MONITOR_GROUP_KERNEL, event, &kernel_monitor);
 247                 if (r < 0)
 248                         goto finalize;
 249
 250                 printf("KERNEL - the kernel uevent\n");
 251         }
 252         printf("\n");
 253
 254         r = sd_event_loop(event);
 255         if (r < 0) {
 256                 log_error_errno(r, "Failed to run event loop: %m");
 257                 goto finalize;
 258         }
 259
 260         r = 0;
 261
 262 finalize:
 263         hashmap_free_free_free(arg_subsystem_filter);
 264         set_free_free(arg_tag_filter);
 265
 266         return r;
 267 }