src/udev/udevadm-trigger.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  *
   4  */
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <getopt.h>
   9 #include <stddef.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13
  14 #include "fd-util.h"
  15 #include "set.h"
  16 #include "string-util.h"
  17 #include "udev-util.h"
  18 #include "udev.h"
  19 #include "udevadm-util.h"
  20 #include "util.h"
  21
  22 static int verbose;
  23 static int dry_run;
  24
  25 static int exec_list(struct udev_enumerate *udev_enumerate, const char *action, Set *settle_set) {
  26         struct udev_list_entry *entry;
  27         int r;
  28
  29         udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(udev_enumerate)) {
  30                 char filename[UTIL_PATH_SIZE];
  31                 const char *syspath;
  32                 _cleanup_close_ int fd = -1;
  33
  34                 syspath = udev_list_entry_get_name(entry);
  35                 if (verbose)
  36                         printf("%s\n", syspath);
  37                 if (dry_run)
  38                         continue;
  39
  40                 strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
  41                 fd = open(filename, O_WRONLY|O_CLOEXEC);
  42                 if (fd < 0)
  43                         continue;
  44
  45                 if (settle_set) {
  46                         r = set_put_strdup(settle_set, syspath);
  47                         if (r < 0)
  48                                 return log_oom();
  49                 }
  50
  51                 if (write(fd, action, strlen(action)) < 0)
  52                         log_debug_errno(errno, "error writing '%s' to '%s': %m", action, filename);
  53         }
  54
  55         return 0;
  56 }
  57
  58 static const char *keyval(const char *str, const char **val, char *buf, size_t size) {
  59         char *pos;
  60
  61         strscpy(buf, size,str);
  62         pos = strchr(buf, '=');
  63         if (pos != NULL) {
  64                 pos[0] = 0;
  65                 pos++;
  66         }
  67         *val = pos;
  68         return buf;
  69 }
  70
  71 static void help(void) {
  72         printf("%s trigger [OPTIONS] DEVPATH\n\n"
  73                "Request events from the kernel.\n\n"
  74                "  -h --help                         Show this help\n"
  75                "  -V --version                      Show package version\n"
  76                "  -v --verbose                      Print the list of devices while running\n"
  77                "  -n --dry-run                      Do not actually trigger the events\n"
  78                "  -t --type=                        Type of events to trigger\n"
  79                "          devices                     sysfs devices (default)\n"
  80                "          subsystems                  sysfs subsystems and drivers\n"
  81                "  -c --action=ACTION                Event action value, default is \"change\"\n"
  82                "  -s --subsystem-match=SUBSYSTEM    Trigger devices from a matching subsystem\n"
  83                "  -S --subsystem-nomatch=SUBSYSTEM  Exclude devices from a matching subsystem\n"
  84                "  -a --attr-match=FILE[=VALUE]      Trigger devices with a matching attribute\n"
  85                "  -A --attr-nomatch=FILE[=VALUE]    Exclude devices with a matching attribute\n"
  86                "  -p --property-match=KEY=VALUE     Trigger devices with a matching property\n"
  87                "  -g --tag-match=KEY=VALUE          Trigger devices with a matching property\n"
  88                "  -y --sysname-match=NAME           Trigger devices with this /sys path\n"
  89                "     --name-match=NAME              Trigger devices with this /dev name\n"
  90                "  -b --parent-match=NAME            Trigger devices with that parent device\n"
  91                "  -w --settle                       Wait for the triggered events to complete\n"
  92                , program_invocation_short_name);
  93 }
  94
  95 static int adm_trigger(struct udev *udev, int argc, char *argv[]) {
  96         enum {
  97                 ARG_NAME = 0x100,
  98         };
  99
 100         static const struct option options[] = {
 101                 { "verbose",           no_argument,       NULL, 'v'      },
 102                 { "dry-run",           no_argument,       NULL, 'n'      },
 103                 { "type",              required_argument, NULL, 't'      },
 104                 { "action",            required_argument, NULL, 'c'      },
 105                 { "subsystem-match",   required_argument, NULL, 's'      },
 106                 { "subsystem-nomatch", required_argument, NULL, 'S'      },
 107                 { "attr-match",        required_argument, NULL, 'a'      },
 108                 { "attr-nomatch",      required_argument, NULL, 'A'      },
 109                 { "property-match",    required_argument, NULL, 'p'      },
 110                 { "tag-match",         required_argument, NULL, 'g'      },
 111                 { "sysname-match",     required_argument, NULL, 'y'      },
 112                 { "name-match",        required_argument, NULL, ARG_NAME },
 113                 { "parent-match",      required_argument, NULL, 'b'      },
 114                 { "settle",            no_argument,       NULL, 'w'      },
 115                 { "version",           no_argument,       NULL, 'V'      },
 116                 { "help",              no_argument,       NULL, 'h'      },
 117                 {}
 118         };
 119         enum {
 120                 TYPE_DEVICES,
 121                 TYPE_SUBSYSTEMS,
 122         } device_type = TYPE_DEVICES;
 123         const char *action = "change";
 124         _cleanup_(udev_enumerate_unrefp) struct udev_enumerate *udev_enumerate = NULL;
 125         _cleanup_(udev_monitor_unrefp) struct udev_monitor *udev_monitor = NULL;
 126         _cleanup_close_ int fd_ep = -1;
 127         int fd_udev = -1;
 128         struct epoll_event ep_udev;
 129         bool settle = false;
 130         _cleanup_set_free_free_ Set *settle_set = NULL;
 131         int c, r;
 132
 133         udev_enumerate = udev_enumerate_new(udev);
 134         if (!udev_enumerate)
 135                 return 1;
 136
 137         while ((c = getopt_long(argc, argv, "vnt:c:s:S:a:A:p:g:y:b:wVh", options, NULL)) >= 0) {
 138                 const char *key;
 139                 const char *val;
 140                 char buf[UTIL_PATH_SIZE];
 141
 142                 switch (c) {
 143                 case 'v':
 144                         verbose = 1;
 145                         break;
 146                 case 'n':
 147                         dry_run = 1;
 148                         break;
 149                 case 't':
 150                         if (streq(optarg, "devices"))
 151                                 device_type = TYPE_DEVICES;
 152                         else if (streq(optarg, "subsystems"))
 153                                 device_type = TYPE_SUBSYSTEMS;
 154                         else {
 155                                 log_error("unknown type --type=%s", optarg);
 156                                 return 2;
 157                         }
 158                         break;
 159                 case 'c':
 160                         if (!STR_IN_SET(optarg, "add", "remove", "change")) {
 161                                 log_error("unknown action '%s'", optarg);
 162                                 return 2;
 163                         } else
 164                                 action = optarg;
 165
 166                         break;
 167                 case 's':
 168                         r = udev_enumerate_add_match_subsystem(udev_enumerate, optarg);
 169                         if (r < 0) {
 170                                 log_error_errno(r, "could not add subsystem match '%s': %m", optarg);
 171                                 return 2;
 172                         }
 173                         break;
 174                 case 'S':
 175                         r = udev_enumerate_add_nomatch_subsystem(udev_enumerate, optarg);
 176                         if (r < 0) {
 177                                 log_error_errno(r, "could not add negative subsystem match '%s': %m", optarg);
 178                                 return 2;
 179                         }
 180                         break;
 181                 case 'a':
 182                         key = keyval(optarg, &val, buf, sizeof(buf));
 183                         r = udev_enumerate_add_match_sysattr(udev_enumerate, key, val);
 184                         if (r < 0) {
 185                                 log_error_errno(r, "could not add sysattr match '%s=%s': %m", key, val);
 186                                 return 2;
 187                         }
 188                         break;
 189                 case 'A':
 190                         key = keyval(optarg, &val, buf, sizeof(buf));
 191                         r = udev_enumerate_add_nomatch_sysattr(udev_enumerate, key, val);
 192                         if (r < 0) {
 193                                 log_error_errno(r, "could not add negative sysattr match '%s=%s': %m", key, val);
 194                                 return 2;
 195                         }
 196                         break;
 197                 case 'p':
 198                         key = keyval(optarg, &val, buf, sizeof(buf));
 199                         r = udev_enumerate_add_match_property(udev_enumerate, key, val);
 200                         if (r < 0) {
 201                                 log_error_errno(r, "could not add property match '%s=%s': %m", key, val);
 202                                 return 2;
 203                         }
 204                         break;
 205                 case 'g':
 206                         r = udev_enumerate_add_match_tag(udev_enumerate, optarg);
 207                         if (r < 0) {
 208                                 log_error_errno(r, "could not add tag match '%s': %m", optarg);
 209                                 return 2;
 210                         }
 211                         break;
 212                 case 'y':
 213                         r = udev_enumerate_add_match_sysname(udev_enumerate, optarg);
 214                         if (r < 0) {
 215                                 log_error_errno(r, "could not add sysname match '%s': %m", optarg);
 216                                 return 2;
 217                         }
 218                         break;
 219                 case 'b': {
 220                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 221
 222                         dev = find_device(udev, optarg, "/sys");
 223                         if (!dev) {
 224                                 log_error("unable to open the device '%s'", optarg);
 225                                 return 2;
 226                         }
 227
 228                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 229                         if (r < 0) {
 230                                 log_error_errno(r, "could not add parent match '%s': %m", optarg);
 231                                 return 2;
 232                         }
 233                         break;
 234                 }
 235                 case 'w':
 236                         settle = true;
 237                         break;
 238
 239                 case ARG_NAME: {
 240                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 241
 242                         dev = find_device(udev, optarg, "/dev/");
 243                         if (!dev) {
 244                                 log_error("unable to open the device '%s'", optarg);
 245                                 return 2;
 246                         }
 247
 248                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 249                         if (r < 0) {
 250                                 log_error_errno(r, "could not add parent match '%s': %m", optarg);
 251                                 return 2;
 252                         }
 253                         break;
 254                 }
 255
 256                 case 'V':
 257                         print_version();
 258                         return 0;
 259                 case 'h':
 260                         help();
 261                         return 0;
 262                 case '?':
 263                         return 1;
 264                 default:
 265                         assert_not_reached("Unknown option");
 266                 }
 267         }
 268
 269         for (; optind < argc; optind++) {
 270                 _cleanup_(udev_device_unrefp) struct udev_device *dev;
 271
 272                 dev = find_device(udev, argv[optind], NULL);
 273                 if (!dev) {
 274                         log_error("unable to open the device '%s'", argv[optind]);
 275                         return 2;
 276                 }
 277
 278                 r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 279                 if (r < 0) {
 280                         log_error_errno(r, "could not add tag match '%s': %m", optarg);
 281                         return 2;
 282                 }
 283         }
 284
 285         if (settle) {
 286                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 287                 if (fd_ep < 0) {
 288                         log_error_errno(errno, "error creating epoll fd: %m");
 289                         return 1;
 290                 }
 291
 292                 udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
 293                 if (!udev_monitor) {
 294                         log_error("error: unable to create netlink socket");
 295                         return 3;
 296                 }
 297                 fd_udev = udev_monitor_get_fd(udev_monitor);
 298
 299                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 300                         log_error("error: unable to subscribe to udev events");
 301                         return 4;
 302                 }
 303
 304                 ep_udev = (struct epoll_event) { .events = EPOLLIN, .data.fd = fd_udev };
 305                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) {
 306                         log_error_errno(errno, "fail to add fd to epoll: %m");
 307                         return 5;
 308                 }
 309
 310                 settle_set = set_new(&string_hash_ops);
 311                 if (!settle_set) {
 312                         log_oom();
 313                         return 1;
 314                 }
 315         }
 316
 317         switch (device_type) {
 318         case TYPE_SUBSYSTEMS:
 319                 udev_enumerate_scan_subsystems(udev_enumerate);
 320                 break;
 321         case TYPE_DEVICES:
 322                 udev_enumerate_scan_devices(udev_enumerate);
 323                 break;
 324         default:
 325                 assert_not_reached("device_type");
 326         }
 327         r = exec_list(udev_enumerate, action, settle_set);
 328         if (r < 0)
 329                 return 1;
 330
 331         while (!set_isempty(settle_set)) {
 332                 int fdcount;
 333                 struct epoll_event ev[4];
 334                 int i;
 335
 336                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 337                 if (fdcount < 0) {
 338                         if (errno != EINTR)
 339                                 log_error_errno(errno, "error receiving uevent message: %m");
 340                         continue;
 341                 }
 342
 343                 for (i = 0; i < fdcount; i++) {
 344                         if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
 345                                 _cleanup_(udev_device_unrefp) struct udev_device *device;
 346                                 const char *syspath = NULL;
 347
 348                                 device = udev_monitor_receive_device(udev_monitor);
 349                                 if (!device)
 350                                         continue;
 351
 352                                 syspath = udev_device_get_syspath(device);
 353                                 if (verbose)
 354                                         printf("settle %s\n", syspath);
 355                                 if (!set_remove(settle_set, syspath))
 356                                         log_debug("Got epoll event on syspath %s not present in syspath set", syspath);
 357                         }
 358                 }
 359         }
 360
 361         return 0;
 362 }
 363
 364 const struct udevadm_cmd udevadm_trigger = {
 365         .name = "trigger",
 366         .cmd = adm_trigger,
 367         .help = "Request events from the kernel",
 368 };