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_dev_add(struct pb_udev *udev, struct udev_device *dev)
  64 {
  65         struct discover_device *ddev;
  66         const char *typestr;
  67         const char *uuid;
  68         const char *path;
  69         const char *name;
  70         const char *node;
  71         const char *prop;
  72         bool cdrom;
  73
  74         name = udev_device_get_sysname(dev);
  75         if (!name) {
  76                 pb_debug("udev_device_get_sysname failed\n");
  77                 return -1;
  78         }
  79
  80         typestr = udev_device_get_devtype(dev);
  81         if (!typestr) {
  82                 pb_debug("udev_device_get_devtype failed\n");
  83                 return -1;
  84         }
  85
  86         if (!(!strcmp(typestr, "disk") || !strcmp(typestr, "partition"))) {
  87                 pb_debug("SKIP %s: invalid type %s\n", name, typestr);
  88                 return 0;
  89         }
  90
  91         node = udev_device_get_devnode(dev);
  92         path = udev_device_get_devpath(dev);
  93         if (path && (strstr(path, "virtual/block/loop")
  94                         || strstr(path, "virtual/block/ram"))) {
  95                 pb_debug("SKIP: %s: ignored (path=%s)\n", name, path);
  96                 return 0;
  97         }
  98
  99         cdrom = node && !!udev_device_get_property_value(dev, "ID_CDROM");
 100         if (cdrom) {
 101                 /* CDROMs require a little initialisation, to get
 102                  * petitboot-compatible tray behaviour */
 103                 cdrom_init(node);
 104                 if (!cdrom_media_present(node)) {
 105                         pb_debug("SKIP: %s: no media present\n", name);
 106                         return 0;
 107                 }
 108         }
 109
 110         /* We have enough info to create the device and start discovery */
 111         ddev = device_lookup_by_id(udev->handler, name);
 112         if (ddev) {
 113                 pb_debug("device %s is already present?\n", name);
 114                 return -1;
 115         }
 116
 117         /* We may see multipath devices; they'll have the same uuid as an
 118          * existing device, so only parse the first. */
 119         uuid = udev_device_get_property_value(dev, "ID_FS_UUID");
 120         if (uuid) {
 121                 ddev = device_lookup_by_uuid(udev->handler, uuid);
 122                 if (ddev) {
 123                         pb_log("SKIP: %s UUID [%s] already present (as %s)\n",
 124                                         name, uuid, ddev->device->id);
 125                         return -1;
 126                 }
 127         }
 128
 129         ddev = discover_device_create(udev->handler, name);
 130
 131         ddev->device_path = talloc_strdup(ddev, node);
 132
 133         if (uuid)
 134                 ddev->uuid = talloc_strdup(ddev, uuid);
 135         prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
 136         if (prop)
 137                 ddev->label = talloc_strdup(ddev, prop);
 138         ddev->device->type = cdrom ? DEVICE_TYPE_OPTICAL : DEVICE_TYPE_DISK;
 139
 140         udev_setup_device_params(dev, ddev);
 141
 142         device_handler_discover(udev->handler, ddev);
 143
 144         return 0;
 145 }
 146
 147 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 148 {
 149         struct discover_device *ddev;
 150         const char *name;
 151
 152         name = udev_device_get_sysname(dev);
 153         if (!name) {
 154                 pb_debug("udev_device_get_sysname failed\n");
 155                 return -1;
 156         }
 157
 158         ddev = device_lookup_by_id(udev->handler, name);
 159         if (!ddev)
 160                 return 0;
 161
 162         device_handler_remove(udev->handler, ddev);
 163
 164         return 0;
 165 }
 166
 167 static int udev_handle_dev_change(struct pb_udev *udev, struct udev_device *dev)
 168 {
 169         struct discover_device *ddev;
 170         const char *name, *node;
 171
 172         name = udev_device_get_sysname(dev);
 173         node = udev_device_get_devnode(dev);
 174
 175         /* we're only interested in CDROM change events at present */
 176         if (!udev_device_get_property_value(dev, "ID_CDROM"))
 177                 return 0;
 178
 179         /* handle CDROM eject requests */
 180         if (udev_device_get_property_value(dev, "DISK_EJECT_REQUEST")) {
 181                 bool eject = false;
 182
 183                 pb_debug("udev: eject request\n");
 184
 185                 /* If the device is mounted, cdrom_id's own eject request may
 186                  * have failed. So, we'll need to do our own here.
 187                  */
 188                 ddev = device_lookup_by_id(udev->handler, name);
 189                 if (ddev) {
 190                         eject = ddev->mounted;
 191                         udev_handle_dev_remove(udev, dev);
 192                 }
 193
 194                 if (eject)
 195                         cdrom_eject(node);
 196
 197                 return 0;
 198         }
 199
 200         if (udev_device_get_property_value(dev, "DISK_MEDIA_CHANGE")) {
 201                 if (cdrom_media_present(node))
 202                         return udev_handle_dev_add(udev, dev);
 203                 else
 204                         return udev_handle_dev_remove(udev, dev);
 205         }
 206
 207         return 0;
 208 }
 209
 210 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 211 {
 212         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 213
 214 #ifdef DEBUG
 215         {
 216                 struct udev_list_entry *list;
 217                 const char *name;
 218
 219                 list = udev_device_get_properties_list_entry(dev);
 220                 name = udev_device_get_sysname(dev);
 221
 222                 pb_debug("%s: action %s, device %s\n", __func__, action, name);
 223                 pb_debug("%s properties:\n", __func__);
 224
 225                 for (; list; list = udev_list_entry_get_next(list))
 226                         pb_log("\t%-20s: %s\n", udev_list_entry_get_name(list),
 227                                         udev_list_entry_get_value(list));
 228         } while (0);
 229 #endif
 230
 231         if (!strcmp(action, "add"))
 232                 return udev_handle_dev_add(udev, dev);
 233
 234         else if (!strcmp(action, "remove"))
 235                 return udev_handle_dev_remove(udev, dev);
 236
 237         else if (!strcmp(action, "change"))
 238                 return udev_handle_dev_change(udev, dev);
 239
 240         return 0;
 241 }
 242
 243 static int udev_enumerate(struct udev *udev)
 244 {
 245         int result;
 246         struct udev_list_entry *list, *entry;
 247         struct udev_enumerate *enumerate;
 248
 249         enumerate = udev_enumerate_new(udev);
 250
 251         if (!enumerate) {
 252                 pb_log("udev_enumerate_new failed\n");
 253                 return -1;
 254         }
 255
 256         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 257
 258         if (result) {
 259                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 260                 goto fail;
 261         }
 262
 263         udev_enumerate_scan_devices(enumerate);
 264
 265         list = udev_enumerate_get_list_entry(enumerate);
 266
 267         if (!list) {
 268                 pb_log("udev_enumerate_get_list_entry failed\n");
 269                 goto fail;
 270         }
 271
 272         udev_list_entry_foreach(entry, list) {
 273                 const char *syspath;
 274                 struct udev_device *dev;
 275
 276                 syspath = udev_list_entry_get_name(entry);
 277                 dev = udev_device_new_from_syspath(udev, syspath);
 278
 279                 udev_handle_dev_action(dev, "add");
 280
 281                 udev_device_unref(dev);
 282         }
 283
 284         udev_enumerate_unref(enumerate);
 285         return 0;
 286
 287 fail:
 288         udev_enumerate_unref(enumerate);
 289         return -1;
 290 }
 291
 292 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 293 {
 294         int result;
 295         struct udev_monitor *m;
 296
 297         *monitor = NULL;
 298         m = udev_monitor_new_from_netlink(udev, "udev");
 299
 300         if (!m) {
 301                 pb_log("udev_monitor_new_from_netlink failed\n");
 302                 goto out_err;
 303         }
 304
 305         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 306                 NULL);
 307
 308         if (result) {
 309                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 310                 goto out_err;
 311         }
 312
 313         result = udev_monitor_enable_receiving(m);
 314
 315         if (result) {
 316                 pb_log("udev_monitor_enable_receiving failed\n");
 317                 goto out_err;
 318         }
 319
 320         *monitor = m;
 321         return 0;
 322
 323 out_err:
 324         udev_monitor_unref(m);
 325         return -1;
 326 }
 327
 328 /*
 329  * udev_process - waiter callback for monitor netlink.
 330  */
 331
 332 static int udev_process(void *arg)
 333 {
 334         struct udev_monitor *monitor = arg;
 335         struct udev_device *dev;
 336         const char *action;
 337         int result;
 338
 339         dev = udev_monitor_receive_device(monitor);
 340
 341         if (!dev) {
 342                 pb_log("udev_monitor_receive_device failed\n");
 343                 return -1;
 344         }
 345
 346         action = udev_device_get_action(dev);
 347
 348         if (!action) {
 349                 pb_log("udev_device_get_action failed\n");
 350                 goto fail;
 351         }
 352
 353         result = udev_handle_dev_action(dev, action);
 354
 355         udev_device_unref(dev);
 356         return result;
 357
 358 fail:
 359         udev_device_unref(dev);
 360         return -1;
 361 }
 362
 363 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 364         int __attribute__((unused)) priority, const char *file, int line,
 365         const char *fn, const char *format, va_list args)
 366 {
 367       pb_log("libudev: %s %s:%d: ", fn, file, line);
 368       vfprintf(pb_log_get_stream(), format, args);
 369 }
 370
 371 struct pb_udev *udev_init(struct waitset *waitset,
 372         struct device_handler *handler)
 373 {
 374         int result;
 375         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 376
 377         talloc_set_destructor(udev, udev_destructor);
 378         udev->handler = handler;
 379
 380         udev->udev = udev_new();
 381
 382         if (!udev->udev) {
 383                 pb_log("udev_new failed\n");
 384                 goto fail_new;
 385         }
 386
 387         udev_set_userdata(udev->udev, udev);
 388
 389         udev_set_log_fn(udev->udev, udev_log_fn);
 390
 391         result = udev_enumerate(udev->udev);
 392
 393         if (result)
 394                 goto fail_enumerate;
 395
 396         result = udev_setup_monitor(udev->udev, &udev->monitor);
 397
 398         if (result)
 399                 goto fail_monitor;
 400
 401         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 402                 udev_process, udev->monitor);
 403
 404         pb_debug("%s: waiting on udev\n", __func__);
 405
 406         return udev;
 407
 408 fail_monitor:
 409 fail_enumerate:
 410         udev_unref(udev->udev);
 411 fail_new:
 412         talloc_free(udev);
 413         return NULL;
 414 }
 415
 416 void udev_destroy(struct pb_udev *udev)
 417 {
 418         talloc_free(udev);
 419 }