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

   1
   2 #define _GNU_SOURCE
   3
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <libudev.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <sys/socket.h>
  12 #include <sys/types.h>
  13 #include <sys/un.h>
  14
  15 #include <log/log.h>
  16 #include <types/types.h>
  17 #include <talloc/talloc.h>
  18 #include <waiter/waiter.h>
  19 #include <system/system.h>
  20
  21 #include "event.h"
  22 #include "udev.h"
  23 #include "pb-discover.h"
  24 #include "device-handler.h"
  25
  26 struct pb_udev {
  27         struct udev *udev;
  28         struct udev_monitor *monitor;
  29         struct device_handler *handler;
  30 };
  31
  32 static int udev_destructor(void *p)
  33 {
  34         struct pb_udev *udev = p;
  35
  36         udev_monitor_unref(udev->monitor);
  37         udev->monitor = NULL;
  38
  39         udev_unref(udev->udev);
  40         udev->udev = NULL;
  41
  42         return 0;
  43 }
  44
  45 static void udev_setup_device_params(struct udev_device *udev,
  46                 struct discover_device *dev)
  47 {
  48         struct udev_list_entry *list, *entry;
  49
  50         list = udev_device_get_properties_list_entry(udev);
  51         if (!list)
  52                 return;
  53
  54         udev_list_entry_foreach(entry, list)
  55                 discover_device_set_param(dev,
  56                                 udev_list_entry_get_name(entry),
  57                                 udev_list_entry_get_value(entry));
  58 }
  59
  60 static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
  61 {
  62         struct discover_device *ddev;
  63         const char *typestr;
  64         const char *serial;
  65         const char *path;
  66         const char *name;
  67         const char *prop;
  68
  69         name = udev_device_get_sysname(dev);
  70         if (!name) {
  71                 pb_debug("udev_device_get_sysname failed\n");
  72                 return -1;
  73         }
  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         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         /* We have enough info to create the device and start discovery */
  94         ddev = device_lookup_by_id(udev->handler, name);
  95         if (ddev) {
  96                 pb_debug("device %s is already present?\n", name);
  97                 return -1;
  98         }
  99
 100         /* we may also see multipath devices; same dev nodes (hence id), but
 101          * different serial numbers */
 102         serial = udev_device_get_property_value(dev, "ID_SERIAL");
 103         if (serial && device_lookup_by_serial(udev->handler, serial))
 104                 return -1;
 105
 106         ddev = discover_device_create(udev->handler, name);
 107
 108         ddev->device_path = udev_device_get_devnode(dev);
 109         prop = udev_device_get_property_value(dev, "ID_FS_UUID");
 110         if (prop)
 111                 ddev->uuid = talloc_strdup(ddev, prop);
 112         prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
 113         if (prop)
 114                 ddev->label = talloc_strdup(ddev, prop);
 115         ddev->device->type = DEVICE_TYPE_DISK;
 116
 117         udev_setup_device_params(dev, ddev);
 118
 119         device_handler_discover(udev->handler, ddev);
 120
 121         return 0;
 122 }
 123
 124 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 125 {
 126         struct discover_device *ddev;
 127         const char *name;
 128
 129         name = udev_device_get_sysname(dev);
 130         if (!name) {
 131                 pb_debug("udev_device_get_sysname failed\n");
 132                 return -1;
 133         }
 134
 135         ddev = device_lookup_by_id(udev->handler, name);
 136         if (!ddev)
 137                 return 0;
 138
 139         device_handler_remove(udev->handler, ddev);
 140
 141         return 0;
 142 }
 143 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 144 {
 145         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 146
 147         if (!strcmp(action, "add"))
 148                 return udev_handle_dev_add(udev, dev);
 149
 150         else if (!strcmp(action, "remove"))
 151                 return udev_handle_dev_remove(udev, dev);
 152
 153         return 0;
 154 }
 155
 156 static int udev_enumerate(struct udev *udev)
 157 {
 158         int result;
 159         struct udev_list_entry *list, *entry;
 160         struct udev_enumerate *enumerate;
 161
 162         enumerate = udev_enumerate_new(udev);
 163
 164         if (!enumerate) {
 165                 pb_log("udev_enumerate_new failed\n");
 166                 return -1;
 167         }
 168
 169         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 170
 171         if (result) {
 172                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 173                 goto fail;
 174         }
 175
 176         udev_enumerate_scan_devices(enumerate);
 177
 178         list = udev_enumerate_get_list_entry(enumerate);
 179
 180         if (!list) {
 181                 pb_log("udev_enumerate_get_list_entry failed\n");
 182                 goto fail;
 183         }
 184
 185         udev_list_entry_foreach(entry, list) {
 186                 const char *syspath;
 187                 struct udev_device *dev;
 188
 189                 syspath = udev_list_entry_get_name(entry);
 190                 dev = udev_device_new_from_syspath(udev, syspath);
 191
 192                 udev_handle_dev_action(dev, "add");
 193
 194                 udev_device_unref(dev);
 195         }
 196
 197         udev_enumerate_unref(enumerate);
 198         return 0;
 199
 200 fail:
 201         udev_enumerate_unref(enumerate);
 202         return -1;
 203 }
 204
 205 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 206 {
 207         int result;
 208         struct udev_monitor *m;
 209
 210         *monitor = NULL;
 211         m = udev_monitor_new_from_netlink(udev, "udev");
 212
 213         if (!m) {
 214                 pb_log("udev_monitor_new_from_netlink failed\n");
 215                 goto out_err;
 216         }
 217
 218         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 219                 NULL);
 220
 221         if (result) {
 222                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 223                 goto out_err;
 224         }
 225
 226         result = udev_monitor_enable_receiving(m);
 227
 228         if (result) {
 229                 pb_log("udev_monitor_enable_receiving failed\n");
 230                 goto out_err;
 231         }
 232
 233         *monitor = m;
 234         return 0;
 235
 236 out_err:
 237         udev_monitor_unref(m);
 238         return -1;
 239 }
 240
 241 /*
 242  * udev_process - waiter callback for monitor netlink.
 243  */
 244
 245 static int udev_process(void *arg)
 246 {
 247         struct udev_monitor *monitor = arg;
 248         struct udev_device *dev;
 249         const char *action;
 250         int result;
 251
 252         dev = udev_monitor_receive_device(monitor);
 253
 254         if (!dev) {
 255                 pb_log("udev_monitor_receive_device failed\n");
 256                 return -1;
 257         }
 258
 259         action = udev_device_get_action(dev);
 260
 261         if (!action) {
 262                 pb_log("udev_device_get_action failed\n");
 263                 goto fail;
 264         }
 265
 266         result = udev_handle_dev_action(dev, action);
 267
 268         udev_device_unref(dev);
 269         return result;
 270
 271 fail:
 272         udev_device_unref(dev);
 273         return -1;
 274 }
 275
 276 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 277         int __attribute__((unused)) priority, const char *file, int line,
 278         const char *fn, const char *format, va_list args)
 279 {
 280       pb_log("libudev: %s %s:%d: ", fn, file, line);
 281       vfprintf(pb_log_get_stream(), format, args);
 282 }
 283
 284 struct pb_udev *udev_init(struct waitset *waitset,
 285         struct device_handler *handler)
 286 {
 287         int result;
 288         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 289
 290         talloc_set_destructor(udev, udev_destructor);
 291         udev->handler = handler;
 292
 293         udev->udev = udev_new();
 294
 295         if (!udev->udev) {
 296                 pb_log("udev_new failed\n");
 297                 goto fail_new;
 298         }
 299
 300         udev_set_userdata(udev->udev, udev);
 301
 302         udev_set_log_fn(udev->udev, udev_log_fn);
 303
 304         result = udev_enumerate(udev->udev);
 305
 306         if (result)
 307                 goto fail_enumerate;
 308
 309         result = udev_setup_monitor(udev->udev, &udev->monitor);
 310
 311         if (result)
 312                 goto fail_monitor;
 313
 314         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 315                 udev_process, udev->monitor);
 316
 317         pb_debug("%s: waiting on udev\n", __func__);
 318
 319         return udev;
 320
 321 fail_monitor:
 322 fail_enumerate:
 323         udev_unref(udev->udev);
 324 fail_new:
 325         talloc_free(udev);
 326         return NULL;
 327 }
 328
 329 void udev_destroy(struct pb_udev *udev)
 330 {
 331         talloc_free(udev);
 332 }