src/udev/udevadm-trigger.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <getopt.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10
  11 #include "fd-util.h"
  12 #include "set.h"
  13 #include "string-util.h"
  14 #include "udev.h"
  15 #include "udevadm-util.h"
  16 #include "util.h"
  17
  18 static int verbose;
  19 static int dry_run;
  20
  21 static int exec_list(struct udev_enumerate *udev_enumerate, const char *action, Set *settle_set) {
  22         struct udev_list_entry *entry;
  23         int r;
  24
  25         udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(udev_enumerate)) {
  26                 char filename[UTIL_PATH_SIZE];
  27                 const char *syspath;
  28                 _cleanup_close_ int fd = -1;
  29
  30                 syspath = udev_list_entry_get_name(entry);
  31                 if (verbose)
  32                         printf("%s\n", syspath);
  33                 if (dry_run)
  34                         continue;
  35
  36                 strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
  37                 fd = open(filename, O_WRONLY|O_CLOEXEC);
  38                 if (fd < 0)
  39                         continue;
  40
  41                 if (settle_set) {
  42                         r = set_put_strdup(settle_set, syspath);
  43                         if (r < 0)
  44                                 return log_oom();
  45                 }
  46
  47                 if (write(fd, action, strlen(action)) < 0)
  48                         log_debug_errno(errno, "error writing '%s' to '%s': %m", action, filename);
  49         }
  50
  51         return 0;
  52 }
  53
  54 static const char *keyval(const char *str, const char **val, char *buf, size_t size) {
  55         char *pos;
  56
  57         strscpy(buf, size,str);
  58         pos = strchr(buf, '=');
  59         if (pos != NULL) {
  60                 pos[0] = 0;
  61                 pos++;
  62         }
  63         *val = pos;
  64         return buf;
  65 }
  66
  67 static void help(void) {
  68         printf("%s trigger [OPTIONS] DEVPATH\n\n"
  69                "Request events from the kernel.\n\n"
  70                "  -h --help                         Show this help\n"
  71                "  -V --version                      Show package version\n"
  72                "  -v --verbose                      Print the list of devices while running\n"
  73                "  -n --dry-run                      Do not actually trigger the events\n"
  74                "  -t --type=                        Type of events to trigger\n"
  75                "          devices                     sysfs devices (default)\n"
  76                "          subsystems                  sysfs subsystems and drivers\n"
  77                "  -c --action=ACTION                Event action value, default is \"change\"\n"
  78                "  -s --subsystem-match=SUBSYSTEM    Trigger devices from a matching subsystem\n"
  79                "  -S --subsystem-nomatch=SUBSYSTEM  Exclude devices from a matching subsystem\n"
  80                "  -a --attr-match=FILE[=VALUE]      Trigger devices with a matching attribute\n"
  81                "  -A --attr-nomatch=FILE[=VALUE]    Exclude devices with a matching attribute\n"
  82                "  -p --property-match=KEY=VALUE     Trigger devices with a matching property\n"
  83                "  -g --tag-match=KEY=VALUE          Trigger devices with a matching property\n"
  84                "  -y --sysname-match=NAME           Trigger devices with this /sys path\n"
  85                "     --name-match=NAME              Trigger devices with this /dev name\n"
  86                "  -b --parent-match=NAME            Trigger devices with that parent device\n"
  87                "  -w --settle                       Wait for the triggered events to complete\n"
  88                , program_invocation_short_name);
  89 }
  90
  91 static int adm_trigger(struct udev *udev, int argc, char *argv[]) {
  92         enum {
  93                 ARG_NAME = 0x100,
  94         };
  95
  96         static const struct option options[] = {
  97                 { "verbose",           no_argument,       NULL, 'v'      },
  98                 { "dry-run",           no_argument,       NULL, 'n'      },
  99                 { "type",              required_argument, NULL, 't'      },
 100                 { "action",            required_argument, NULL, 'c'      },
 101                 { "subsystem-match",   required_argument, NULL, 's'      },
 102                 { "subsystem-nomatch", required_argument, NULL, 'S'      },
 103                 { "attr-match",        required_argument, NULL, 'a'      },
 104                 { "attr-nomatch",      required_argument, NULL, 'A'      },
 105                 { "property-match",    required_argument, NULL, 'p'      },
 106                 { "tag-match",         required_argument, NULL, 'g'      },
 107                 { "sysname-match",     required_argument, NULL, 'y'      },
 108                 { "name-match",        required_argument, NULL, ARG_NAME },
 109                 { "parent-match",      required_argument, NULL, 'b'      },
 110                 { "settle",            no_argument,       NULL, 'w'      },
 111                 { "version",           no_argument,       NULL, 'V'      },
 112                 { "help",              no_argument,       NULL, 'h'      },
 113                 {}
 114         };
 115         enum {
 116                 TYPE_DEVICES,
 117                 TYPE_SUBSYSTEMS,
 118         } device_type = TYPE_DEVICES;
 119         const char *action = "change";
 120         _cleanup_(udev_enumerate_unrefp) struct udev_enumerate *udev_enumerate = NULL;
 121         _cleanup_(udev_monitor_unrefp) struct udev_monitor *udev_monitor = NULL;
 122         _cleanup_close_ int fd_ep = -1;
 123         int fd_udev = -1;
 124         struct epoll_event ep_udev;
 125         bool settle = false;
 126         _cleanup_set_free_free_ Set *settle_set = NULL;
 127         int c, r;
 128
 129         udev_enumerate = udev_enumerate_new(udev);
 130         if (!udev_enumerate)
 131                 return 1;
 132
 133         while ((c = getopt_long(argc, argv, "vnt:c:s:S:a:A:p:g:y:b:wVh", options, NULL)) >= 0) {
 134                 const char *key;
 135                 const char *val;
 136                 char buf[UTIL_PATH_SIZE];
 137
 138                 switch (c) {
 139                 case 'v':
 140                         verbose = 1;
 141                         break;
 142                 case 'n':
 143                         dry_run = 1;
 144                         break;
 145                 case 't':
 146                         if (streq(optarg, "devices"))
 147                                 device_type = TYPE_DEVICES;
 148                         else if (streq(optarg, "subsystems"))
 149                                 device_type = TYPE_SUBSYSTEMS;
 150                         else {
 151                                 log_error("unknown type --type=%s", optarg);
 152                                 return 2;
 153                         }
 154                         break;
 155                 case 'c':
 156                         if (!STR_IN_SET(optarg, "add", "remove", "change")) {
 157                                 log_error("unknown action '%s'", optarg);
 158                                 return 2;
 159                         } else
 160                                 action = optarg;
 161
 162                         break;
 163                 case 's':
 164                         r = udev_enumerate_add_match_subsystem(udev_enumerate, optarg);
 165                         if (r < 0) {
 166                                 log_error_errno(r, "could not add subsystem match '%s': %m", optarg);
 167                                 return 2;
 168                         }
 169                         break;
 170                 case 'S':
 171                         r = udev_enumerate_add_nomatch_subsystem(udev_enumerate, optarg);
 172                         if (r < 0) {
 173                                 log_error_errno(r, "could not add negative subsystem match '%s': %m", optarg);
 174                                 return 2;
 175                         }
 176                         break;
 177                 case 'a':
 178                         key = keyval(optarg, &val, buf, sizeof(buf));
 179                         r = udev_enumerate_add_match_sysattr(udev_enumerate, key, val);
 180                         if (r < 0) {
 181                                 log_error_errno(r, "could not add sysattr match '%s=%s': %m", key, val);
 182                                 return 2;
 183                         }
 184                         break;
 185                 case 'A':
 186                         key = keyval(optarg, &val, buf, sizeof(buf));
 187                         r = udev_enumerate_add_nomatch_sysattr(udev_enumerate, key, val);
 188                         if (r < 0) {
 189                                 log_error_errno(r, "could not add negative sysattr match '%s=%s': %m", key, val);
 190                                 return 2;
 191                         }
 192                         break;
 193                 case 'p':
 194                         key = keyval(optarg, &val, buf, sizeof(buf));
 195                         r = udev_enumerate_add_match_property(udev_enumerate, key, val);
 196                         if (r < 0) {
 197                                 log_error_errno(r, "could not add property match '%s=%s': %m", key, val);
 198                                 return 2;
 199                         }
 200                         break;
 201                 case 'g':
 202                         r = udev_enumerate_add_match_tag(udev_enumerate, optarg);
 203                         if (r < 0) {
 204                                 log_error_errno(r, "could not add tag match '%s': %m", optarg);
 205                                 return 2;
 206                         }
 207                         break;
 208                 case 'y':
 209                         r = udev_enumerate_add_match_sysname(udev_enumerate, optarg);
 210                         if (r < 0) {
 211                                 log_error_errno(r, "could not add sysname match '%s': %m", optarg);
 212                                 return 2;
 213                         }
 214                         break;
 215                 case 'b': {
 216                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 217
 218                         dev = find_device(udev, optarg, "/sys");
 219                         if (!dev) {
 220                                 log_error("unable to open the device '%s'", optarg);
 221                                 return 2;
 222                         }
 223
 224                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 225                         if (r < 0) {
 226                                 log_error_errno(r, "could not add parent match '%s': %m", optarg);
 227                                 return 2;
 228                         }
 229                         break;
 230                 }
 231                 case 'w':
 232                         settle = true;
 233                         break;
 234
 235                 case ARG_NAME: {
 236                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 237
 238                         dev = find_device(udev, optarg, "/dev/");
 239                         if (!dev) {
 240                                 log_error("unable to open the device '%s'", optarg);
 241                                 return 2;
 242                         }
 243
 244                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 245                         if (r < 0) {
 246                                 log_error_errno(r, "could not add parent match '%s': %m", optarg);
 247                                 return 2;
 248                         }
 249                         break;
 250                 }
 251
 252                 case 'V':
 253                         print_version();
 254                         return 0;
 255                 case 'h':
 256                         help();
 257                         return 0;
 258                 case '?':
 259                         return 1;
 260                 default:
 261                         assert_not_reached("Unknown option");
 262                 }
 263         }
 264
 265         for (; optind < argc; optind++) {
 266                 _cleanup_(udev_device_unrefp) struct udev_device *dev;
 267
 268                 dev = find_device(udev, argv[optind], NULL);
 269                 if (!dev) {
 270                         log_error("unable to open the device '%s'", argv[optind]);
 271                         return 2;
 272                 }
 273
 274                 r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 275                 if (r < 0) {
 276                         log_error_errno(r, "could not add tag match '%s': %m", optarg);
 277                         return 2;
 278                 }
 279         }
 280
 281         if (settle) {
 282                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 283                 if (fd_ep < 0) {
 284                         log_error_errno(errno, "error creating epoll fd: %m");
 285                         return 1;
 286                 }
 287
 288                 udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
 289                 if (!udev_monitor) {
 290                         log_error("error: unable to create netlink socket");
 291                         return 3;
 292                 }
 293                 fd_udev = udev_monitor_get_fd(udev_monitor);
 294
 295                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 296                         log_error("error: unable to subscribe to udev events");
 297                         return 4;
 298                 }
 299
 300                 ep_udev = (struct epoll_event) { .events = EPOLLIN, .data.fd = fd_udev };
 301                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) {
 302                         log_error_errno(errno, "fail to add fd to epoll: %m");
 303                         return 5;
 304                 }
 305
 306                 settle_set = set_new(&string_hash_ops);
 307                 if (!settle_set) {
 308                         log_oom();
 309                         return 1;
 310                 }
 311         }
 312
 313         switch (device_type) {
 314         case TYPE_SUBSYSTEMS:
 315                 udev_enumerate_scan_subsystems(udev_enumerate);
 316                 break;
 317         case TYPE_DEVICES:
 318                 udev_enumerate_scan_devices(udev_enumerate);
 319                 break;
 320         default:
 321                 assert_not_reached("device_type");
 322         }
 323         r = exec_list(udev_enumerate, action, settle_set);
 324         if (r < 0)
 325                 return 1;
 326
 327         while (!set_isempty(settle_set)) {
 328                 int fdcount;
 329                 struct epoll_event ev[4];
 330                 int i;
 331
 332                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 333                 if (fdcount < 0) {
 334                         if (errno != EINTR)
 335                                 log_error_errno(errno, "error receiving uevent message: %m");
 336                         continue;
 337                 }
 338
 339                 for (i = 0; i < fdcount; i++) {
 340                         if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
 341                                 _cleanup_(udev_device_unrefp) struct udev_device *device;
 342                                 const char *syspath = NULL;
 343
 344                                 device = udev_monitor_receive_device(udev_monitor);
 345                                 if (!device)
 346                                         continue;
 347
 348                                 syspath = udev_device_get_syspath(device);
 349                                 if (verbose)
 350                                         printf("settle %s\n", syspath);
 351                                 if (!set_remove(settle_set, syspath))
 352                                         log_debug("Got epoll event on syspath %s not present in syspath set", syspath);
 353                         }
 354                 }
 355         }
 356
 357         return 0;
 358 }
 359
 360 const struct udevadm_cmd udevadm_trigger = {
 361         .name = "trigger",
 362         .cmd = adm_trigger,
 363         .help = "Request events from the kernel",
 364 };