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 #if defined(DEBUG)
  27 #define DBG(fmt, args...) pb_log("DBG: " fmt, ## args)
  28 #define DBGS(fmt, args...) \
  29         pb_log("DBG:%s:%d: " fmt, __func__, __LINE__, ## args)
  30 #else
  31 #define DBG(fmt, args...)
  32 #define DBGS(fmt, args...)
  33 #endif
  34
  35 struct pb_udev {
  36         struct udev *udev;
  37         struct udev_monitor *monitor;
  38         struct device_handler *handler;
  39 };
  40
  41 static int udev_destructor(void *p)
  42 {
  43         struct pb_udev *udev = p;
  44
  45         udev_monitor_unref(udev->monitor);
  46         udev->monitor = NULL;
  47
  48         udev_unref(udev->udev);
  49         udev->udev = NULL;
  50
  51         return 0;
  52 }
  53
  54 static void udev_setup_device_params(struct udev_device *udev,
  55                 struct discover_device *dev)
  56 {
  57         struct udev_list_entry *list, *entry;
  58
  59         list = udev_device_get_properties_list_entry(udev);
  60         if (!list)
  61                 return;
  62
  63         udev_list_entry_foreach(entry, list)
  64                 discover_device_set_param(dev,
  65                                 udev_list_entry_get_name(entry),
  66                                 udev_list_entry_get_value(entry));
  67 }
  68
  69 static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
  70 {
  71         struct discover_device *ddev;
  72         const char *typestr;
  73         const char *path;
  74         const char *name;
  75
  76         name = udev_device_get_sysname(dev);
  77         if (!name) {
  78                 pb_debug("udev_device_get_sysname failed\n");
  79                 return -1;
  80         }
  81
  82         typestr = udev_device_get_devtype(dev);
  83         if (!typestr) {
  84                 pb_debug("udev_device_get_devtype failed\n");
  85                 return -1;
  86         }
  87
  88         if (!(!strcmp(typestr, "disk") || !strcmp(typestr, "partition"))) {
  89                 pb_debug("SKIP %s: invalid type %s\n", name, typestr);
  90                 return 0;
  91         }
  92
  93         path = udev_device_get_devpath(dev);
  94         if (path && (strstr(path, "virtual/block/loop")
  95                         || strstr(path, "virtual/block/ram"))) {
  96                 pb_debug("SKIP: %s: ignored (path=%s)\n", name, path);
  97                 return 0;
  98         }
  99
 100         /* We have enough info to create the device and start discovery */
 101         ddev = device_lookup_by_id(udev->handler, name);
 102         if (ddev) {
 103                 pb_debug("device %s is already present?\n", name);
 104                 return -1;
 105         }
 106
 107         ddev = discover_device_create(udev->handler, name);
 108
 109         ddev->device_path = udev_device_get_devnode(dev);
 110         ddev->uuid = udev_device_get_property_value(dev, "ID_FS_UUID");
 111         ddev->label = udev_device_get_property_value(dev, "ID_FS_LABEL");
 112         ddev->device->type = DEVICE_TYPE_DISK;
 113
 114         udev_setup_device_params(dev, ddev);
 115
 116         device_handler_discover(udev->handler, ddev, CONF_METHOD_LOCAL_FILE);
 117
 118         return 0;
 119 }
 120
 121 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 122 {
 123         struct discover_device *ddev;
 124         const char *name;
 125
 126         name = udev_device_get_sysname(dev);
 127         if (!name) {
 128                 pb_debug("udev_device_get_sysname failed\n");
 129                 return -1;
 130         }
 131
 132         ddev = device_lookup_by_id(udev->handler, name);
 133         if (!ddev)
 134                 return 0;
 135
 136         device_handler_remove(udev->handler, ddev);
 137
 138         return 0;
 139 }
 140 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 141 {
 142         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 143
 144         if (!strcmp(action, "add"))
 145                 return udev_handle_dev_add(udev, dev);
 146
 147         else if (!strcmp(action, "remove"))
 148                 return udev_handle_dev_remove(udev, dev);
 149
 150         return 0;
 151 }
 152
 153 static int udev_enumerate(struct udev *udev)
 154 {
 155         int result;
 156         struct udev_list_entry *list, *entry;
 157         struct udev_enumerate *enumerate;
 158
 159         enumerate = udev_enumerate_new(udev);
 160
 161         if (!enumerate) {
 162                 pb_log("udev_enumerate_new failed\n");
 163                 return -1;
 164         }
 165
 166         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 167
 168         if (result) {
 169                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 170                 goto fail;
 171         }
 172
 173         udev_enumerate_scan_devices(enumerate);
 174
 175         list = udev_enumerate_get_list_entry(enumerate);
 176
 177         if (!list) {
 178                 pb_log("udev_enumerate_get_list_entry failed\n");
 179                 goto fail;
 180         }
 181
 182         udev_list_entry_foreach(entry, list) {
 183                 const char *syspath;
 184                 struct udev_device *dev;
 185
 186                 syspath = udev_list_entry_get_name(entry);
 187                 dev = udev_device_new_from_syspath(udev, syspath);
 188
 189                 udev_handle_dev_action(dev, "add");
 190
 191                 udev_device_unref(dev);
 192         }
 193
 194         udev_enumerate_unref(enumerate);
 195         return 0;
 196
 197 fail:
 198         udev_enumerate_unref(enumerate);
 199         return -1;
 200 }
 201
 202 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 203 {
 204         int result;
 205         struct udev_monitor *m;
 206
 207         *monitor = NULL;
 208         m = udev_monitor_new_from_netlink(udev, "udev");
 209
 210         if (!m) {
 211                 pb_log("udev_monitor_new_from_netlink failed\n");
 212                 goto out_err;
 213         }
 214
 215         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 216                 NULL);
 217
 218         if (result) {
 219                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 220                 goto out_err;
 221         }
 222
 223         result = udev_monitor_enable_receiving(m);
 224
 225         if (result) {
 226                 pb_log("udev_monitor_enable_receiving failed\n");
 227                 goto out_err;
 228         }
 229
 230         *monitor = m;
 231         return 0;
 232
 233 out_err:
 234         udev_monitor_unref(m);
 235         return -1;
 236 }
 237
 238 /*
 239  * udev_process - waiter callback for monitor netlink.
 240  */
 241
 242 static int udev_process(void *arg)
 243 {
 244         struct udev_monitor *monitor = arg;
 245         struct udev_device *dev;
 246         const char *action;
 247         int result;
 248
 249         dev = udev_monitor_receive_device(monitor);
 250
 251         if (!dev) {
 252                 pb_log("udev_monitor_receive_device failed\n");
 253                 return -1;
 254         }
 255
 256         action = udev_device_get_action(dev);
 257
 258         if (!action) {
 259                 pb_log("udev_device_get_action failed\n");
 260                 goto fail;
 261         }
 262
 263         result = udev_handle_dev_action(dev, action);
 264
 265         udev_device_unref(dev);
 266         return result;
 267
 268 fail:
 269         udev_device_unref(dev);
 270         return -1;
 271 }
 272
 273 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 274         int __attribute__((unused)) priority, const char *file, int line,
 275         const char *fn, const char *format, va_list args)
 276 {
 277       pb_log("libudev: %s %s:%d: ", fn, file, line);
 278       vfprintf(pb_log_get_stream(), format, args);
 279 }
 280
 281 struct pb_udev *udev_init(struct waitset *waitset,
 282         struct device_handler *handler)
 283 {
 284         int result;
 285         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 286
 287         talloc_set_destructor(udev, udev_destructor);
 288         udev->handler = handler;
 289
 290         udev->udev = udev_new();
 291
 292         if (!udev->udev) {
 293                 pb_log("udev_new failed\n");
 294                 goto fail_new;
 295         }
 296
 297         udev_set_userdata(udev->udev, udev);
 298
 299         udev_set_log_fn(udev->udev, udev_log_fn);
 300
 301         result = udev_enumerate(udev->udev);
 302
 303         if (result)
 304                 goto fail_enumerate;
 305
 306         result = udev_setup_monitor(udev->udev, &udev->monitor);
 307
 308         if (result)
 309                 goto fail_monitor;
 310
 311         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 312                 udev_process, udev->monitor);
 313
 314         pb_log("%s: waiting on udev\n", __func__);
 315
 316         return udev;
 317
 318 fail_monitor:
 319 fail_enumerate:
 320         udev_unref(udev->udev);
 321 fail_new:
 322         talloc_free(udev);
 323         return NULL;
 324 }
 325
 326 void udev_destroy(struct pb_udev *udev)
 327 {
 328         talloc_free(udev);
 329 }