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