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