git.ozlabs.org Git - petitboot/blob - discover/udev.c

   1
   2 #if defined(HAVE_CONFIG_H)
   3 #include "config.h"
   4 #endif
   5
   6 #include <assert.h>
   7 #include <errno.h>
   8 #include <libudev.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <sys/socket.h>
  14 #include <sys/types.h>
  15 #include <sys/un.h>
  16
  17 #include <log/log.h>
  18 #include <types/types.h>
  19 #include <talloc/talloc.h>
  20 #include <waiter/waiter.h>
  21 #include <system/system.h>
  22
  23 #include "event.h"
  24 #include "udev.h"
  25 #include "pb-discover.h"
  26 #include "device-handler.h"
  27 #include "cdrom.h"
  28
  29 struct pb_udev {
  30         struct udev *udev;
  31         struct udev_monitor *monitor;
  32         struct device_handler *handler;
  33 };
  34
  35 static int udev_destructor(void *p)
  36 {
  37         struct pb_udev *udev = p;
  38
  39         udev_monitor_unref(udev->monitor);
  40         udev->monitor = NULL;
  41
  42         udev_unref(udev->udev);
  43         udev->udev = NULL;
  44
  45         return 0;
  46 }
  47
  48 static void udev_setup_device_params(struct udev_device *udev,
  49                 struct discover_device *dev)
  50 {
  51         struct udev_list_entry *list, *entry;
  52
  53         list = udev_device_get_properties_list_entry(udev);
  54         if (!list)
  55                 return;
  56
  57         udev_list_entry_foreach(entry, list)
  58                 discover_device_set_param(dev,
  59                                 udev_list_entry_get_name(entry),
  60                                 udev_list_entry_get_value(entry));
  61 }
  62
  63 static int udev_handle_block_add(struct pb_udev *udev, struct udev_device *dev,
  64                 const char *name)
  65 {
  66         struct discover_device *ddev;
  67         const char *typestr;
  68         const char *uuid;
  69         const char *path;
  70         const char *node;
  71         const char *prop;
  72         const char *type;
  73         bool cdrom;
  74
  75         typestr = udev_device_get_devtype(dev);
  76         if (!typestr) {
  77                 pb_debug("udev_device_get_devtype failed\n");
  78                 return -1;
  79         }
  80
  81         if (!(!strcmp(typestr, "disk") || !strcmp(typestr, "partition"))) {
  82                 pb_debug("SKIP %s: invalid type %s\n", name, typestr);
  83                 return 0;
  84         }
  85
  86         node = udev_device_get_devnode(dev);
  87         path = udev_device_get_devpath(dev);
  88         if (path && (strstr(path, "virtual/block/loop")
  89                         || strstr(path, "virtual/block/ram"))) {
  90                 pb_debug("SKIP: %s: ignored (path=%s)\n", name, path);
  91                 return 0;
  92         }
  93
  94         cdrom = node && !!udev_device_get_property_value(dev, "ID_CDROM");
  95         if (cdrom) {
  96                 /* CDROMs require a little initialisation, to get
  97                  * petitboot-compatible tray behaviour */
  98                 cdrom_init(node);
  99                 if (!cdrom_media_present(node)) {
 100                         pb_debug("SKIP: %s: no media present\n", name);
 101                         return 0;
 102                 }
 103         }
 104
 105         type = udev_device_get_property_value(dev, "ID_FS_TYPE");
 106         if (!type) {
 107                 pb_debug("SKIP: %s: no ID_FS_TYPE property\n", name);
 108                 return 0;
 109         }
 110
 111         /* We may see multipath devices; they'll have the same uuid as an
 112          * existing device, so only parse the first. */
 113         uuid = udev_device_get_property_value(dev, "ID_FS_UUID");
 114         if (uuid) {
 115                 ddev = device_lookup_by_uuid(udev->handler, uuid);
 116                 if (ddev) {
 117                         pb_log("SKIP: %s UUID [%s] already present (as %s)\n",
 118                                         name, uuid, ddev->device->id);
 119                         return -1;
 120                 }
 121         }
 122
 123         ddev = discover_device_create(udev->handler, name);
 124
 125         ddev->device_path = talloc_strdup(ddev, node);
 126
 127         if (uuid)
 128                 ddev->uuid = talloc_strdup(ddev, uuid);
 129         prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
 130         if (prop)
 131                 ddev->label = talloc_strdup(ddev, prop);
 132         ddev->device->type = cdrom ? DEVICE_TYPE_OPTICAL : DEVICE_TYPE_DISK;
 133
 134         udev_setup_device_params(dev, ddev);
 135
 136         device_handler_discover(udev->handler, ddev);
 137
 138         return 0;
 139 }
 140
 141 static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
 142 {
 143         const char *subsys;
 144         const char *name;
 145
 146         name = udev_device_get_sysname(dev);
 147         if (!name) {
 148                 pb_debug("udev_device_get_sysname failed\n");
 149                 return -1;
 150         }
 151
 152         subsys = udev_device_get_subsystem(dev);
 153         if (!subsys) {
 154                 pb_debug("udev_device_get_subsystem failed\n");
 155                 return -1;
 156         }
 157
 158         if (device_lookup_by_id(udev->handler, name)) {
 159                 pb_debug("device %s is already present?\n", name);
 160                 return -1;
 161         }
 162
 163         if (!strcmp(subsys, "block")) {
 164                 return udev_handle_block_add(udev, dev, name);
 165         }
 166
 167         pb_debug("SKIP %s: unknown subsystem %s\n", name, subsys);
 168         return -1;
 169 }
 170
 171
 172 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 173 {
 174         struct discover_device *ddev;
 175         const char *name;
 176
 177         name = udev_device_get_sysname(dev);
 178         if (!name) {
 179                 pb_debug("udev_device_get_sysname failed\n");
 180                 return -1;
 181         }
 182
 183         ddev = device_lookup_by_id(udev->handler, name);
 184         if (!ddev)
 185                 return 0;
 186
 187         device_handler_remove(udev->handler, ddev);
 188
 189         return 0;
 190 }
 191
 192 /* returns true if further event processing should stop (eg., we've
 193  * ejected the cdrom)
 194  */
 195 static bool udev_handle_cdrom_events(struct pb_udev *udev,
 196                 struct udev_device *dev, struct discover_device *ddev)
 197 {
 198         const char *node;
 199
 200         node = udev_device_get_devnode(dev);
 201
 202         /* handle CDROM eject requests */
 203         if (udev_device_get_property_value(dev, "DISK_EJECT_REQUEST")) {
 204                 bool eject = false;
 205
 206                 pb_debug("udev: eject request\n");
 207
 208                 /* If the device is mounted, cdrom_id's own eject request may
 209                  * have failed. So, we'll need to do our own here.
 210                  */
 211                 if (ddev) {
 212                         eject = ddev->mounted;
 213                         udev_handle_dev_remove(udev, dev);
 214                         return false;
 215                 }
 216
 217                 if (eject)
 218                         cdrom_eject(node);
 219
 220                 return true;
 221         }
 222
 223         if (udev_device_get_property_value(dev, "DISK_MEDIA_CHANGE")) {
 224                 if (cdrom_media_present(node))
 225                         udev_handle_dev_add(udev, dev);
 226                 else
 227                         udev_handle_dev_remove(udev, dev);
 228                 return true;
 229         }
 230
 231         return false;
 232 }
 233
 234 static int udev_handle_dev_change(struct pb_udev *udev, struct udev_device *dev)
 235 {
 236         struct discover_device *ddev;
 237         const char *name;
 238         int rc = 0;
 239
 240         name = udev_device_get_sysname(dev);
 241
 242         ddev = device_lookup_by_id(udev->handler, name);
 243
 244         /* if this is a CDROM device, process eject & media change requests;
 245          * these may stop further processing */
 246         if (!udev_device_get_property_value(dev, "ID_CDROM")) {
 247                 if (udev_handle_cdrom_events(udev, dev, ddev))
 248                         return 0;
 249         }
 250
 251         /* if this is a new device, treat it as an add */
 252         if (!ddev)
 253                 rc = udev_handle_dev_add(udev, dev);
 254
 255         return rc;
 256 }
 257
 258 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 259 {
 260         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 261
 262 #ifdef DEBUG
 263         {
 264                 struct udev_list_entry *list;
 265                 const char *name;
 266
 267                 list = udev_device_get_properties_list_entry(dev);
 268                 name = udev_device_get_sysname(dev);
 269
 270                 pb_debug("%s: action %s, device %s\n", __func__, action, name);
 271                 pb_debug("%s properties:\n", __func__);
 272
 273                 for (; list; list = udev_list_entry_get_next(list))
 274                         pb_log("\t%-20s: %s\n", udev_list_entry_get_name(list),
 275                                         udev_list_entry_get_value(list));
 276         } while (0);
 277 #endif
 278
 279         if (!strcmp(action, "add"))
 280                 return udev_handle_dev_add(udev, dev);
 281
 282         else if (!strcmp(action, "remove"))
 283                 return udev_handle_dev_remove(udev, dev);
 284
 285         else if (!strcmp(action, "change"))
 286                 return udev_handle_dev_change(udev, dev);
 287
 288         return 0;
 289 }
 290
 291 static int udev_enumerate(struct udev *udev)
 292 {
 293         int result;
 294         struct udev_list_entry *list, *entry;
 295         struct udev_enumerate *enumerate;
 296
 297         enumerate = udev_enumerate_new(udev);
 298
 299         if (!enumerate) {
 300                 pb_log("udev_enumerate_new failed\n");
 301                 return -1;
 302         }
 303
 304         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 305         if (result) {
 306                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 307                 goto fail;
 308         }
 309
 310         result = udev_enumerate_add_match_is_initialized(enumerate);
 311         if (result) {
 312                 pb_log("udev_enumerate_add_match_is_initialised failed\n");
 313                 goto fail;
 314         }
 315
 316         udev_enumerate_scan_devices(enumerate);
 317
 318         list = udev_enumerate_get_list_entry(enumerate);
 319
 320         if (!list) {
 321                 pb_log("udev_enumerate_get_list_entry failed\n");
 322                 goto fail;
 323         }
 324
 325         udev_list_entry_foreach(entry, list) {
 326                 const char *syspath;
 327                 struct udev_device *dev;
 328
 329                 syspath = udev_list_entry_get_name(entry);
 330                 dev = udev_device_new_from_syspath(udev, syspath);
 331
 332                 udev_handle_dev_action(dev, "add");
 333
 334                 udev_device_unref(dev);
 335         }
 336
 337         udev_enumerate_unref(enumerate);
 338         return 0;
 339
 340 fail:
 341         udev_enumerate_unref(enumerate);
 342         return -1;
 343 }
 344
 345 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 346 {
 347         int result;
 348         struct udev_monitor *m;
 349
 350         *monitor = NULL;
 351         m = udev_monitor_new_from_netlink(udev, "udev");
 352
 353         if (!m) {
 354                 pb_log("udev_monitor_new_from_netlink failed\n");
 355                 goto out_err;
 356         }
 357
 358         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 359                 NULL);
 360
 361         if (result) {
 362                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 363                 goto out_err;
 364         }
 365
 366         result = udev_monitor_enable_receiving(m);
 367
 368         if (result) {
 369                 pb_log("udev_monitor_enable_receiving failed\n");
 370                 goto out_err;
 371         }
 372
 373         *monitor = m;
 374         return 0;
 375
 376 out_err:
 377         udev_monitor_unref(m);
 378         return -1;
 379 }
 380
 381 /*
 382  * udev_process - waiter callback for monitor netlink.
 383  */
 384
 385 static int udev_process(void *arg)
 386 {
 387         struct udev_monitor *monitor = arg;
 388         struct udev_device *dev;
 389         const char *action;
 390         int result;
 391
 392         dev = udev_monitor_receive_device(monitor);
 393
 394         if (!dev) {
 395                 pb_log("udev_monitor_receive_device failed\n");
 396                 return -1;
 397         }
 398
 399         action = udev_device_get_action(dev);
 400
 401         if (!action) {
 402                 pb_log("udev_device_get_action failed\n");
 403                 goto fail;
 404         }
 405
 406         result = udev_handle_dev_action(dev, action);
 407
 408         udev_device_unref(dev);
 409         return result;
 410
 411 fail:
 412         udev_device_unref(dev);
 413         return -1;
 414 }
 415
 416 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 417         int __attribute__((unused)) priority, const char *file, int line,
 418         const char *fn, const char *format, va_list args)
 419 {
 420       pb_log("libudev: %s %s:%d: ", fn, file, line);
 421       vfprintf(pb_log_get_stream(), format, args);
 422 }
 423
 424 struct pb_udev *udev_init(struct waitset *waitset,
 425         struct device_handler *handler)
 426 {
 427         int result;
 428         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 429
 430         talloc_set_destructor(udev, udev_destructor);
 431         udev->handler = handler;
 432
 433         udev->udev = udev_new();
 434
 435         if (!udev->udev) {
 436                 pb_log("udev_new failed\n");
 437                 goto fail_new;
 438         }
 439
 440         udev_set_userdata(udev->udev, udev);
 441
 442         udev_set_log_fn(udev->udev, udev_log_fn);
 443
 444         result = udev_setup_monitor(udev->udev, &udev->monitor);
 445         if (result)
 446                 goto fail_monitor;
 447
 448         result = udev_enumerate(udev->udev);
 449         if (result)
 450                 goto fail_enumerate;
 451
 452         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 453                 udev_process, udev->monitor);
 454
 455         pb_debug("%s: waiting on udev\n", __func__);
 456
 457         return udev;
 458
 459 fail_monitor:
 460         udev_monitor_unref(udev->monitor);
 461 fail_enumerate:
 462         udev_unref(udev->udev);
 463 fail_new:
 464         talloc_free(udev);
 465         return NULL;
 466 }
 467
 468 void udev_destroy(struct pb_udev *udev)
 469 {
 470         talloc_free(udev);
 471 }