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 = talloc_strdup(ddev, udev_device_get_devnode(dev));
 109
 110         prop = udev_device_get_property_value(dev, "ID_FS_UUID");
 111         if (prop)
 112                 ddev->uuid = talloc_strdup(ddev, prop);
 113         prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
 114         if (prop)
 115                 ddev->label = talloc_strdup(ddev, prop);
 116         ddev->device->type = DEVICE_TYPE_DISK;
 117
 118         udev_setup_device_params(dev, ddev);
 119
 120         device_handler_discover(udev->handler, ddev);
 121
 122         return 0;
 123 }
 124
 125 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 126 {
 127         struct discover_device *ddev;
 128         const char *name;
 129
 130         name = udev_device_get_sysname(dev);
 131         if (!name) {
 132                 pb_debug("udev_device_get_sysname failed\n");
 133                 return -1;
 134         }
 135
 136         ddev = device_lookup_by_id(udev->handler, name);
 137         if (!ddev)
 138                 return 0;
 139
 140         device_handler_remove(udev->handler, ddev);
 141
 142         return 0;
 143 }
 144 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 145 {
 146         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 147
 148         if (!strcmp(action, "add"))
 149                 return udev_handle_dev_add(udev, dev);
 150
 151         else if (!strcmp(action, "remove"))
 152                 return udev_handle_dev_remove(udev, dev);
 153
 154         return 0;
 155 }
 156
 157 static int udev_enumerate(struct udev *udev)
 158 {
 159         int result;
 160         struct udev_list_entry *list, *entry;
 161         struct udev_enumerate *enumerate;
 162
 163         enumerate = udev_enumerate_new(udev);
 164
 165         if (!enumerate) {
 166                 pb_log("udev_enumerate_new failed\n");
 167                 return -1;
 168         }
 169
 170         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 171
 172         if (result) {
 173                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 174                 goto fail;
 175         }
 176
 177         udev_enumerate_scan_devices(enumerate);
 178
 179         list = udev_enumerate_get_list_entry(enumerate);
 180
 181         if (!list) {
 182                 pb_log("udev_enumerate_get_list_entry failed\n");
 183                 goto fail;
 184         }
 185
 186         udev_list_entry_foreach(entry, list) {
 187                 const char *syspath;
 188                 struct udev_device *dev;
 189
 190                 syspath = udev_list_entry_get_name(entry);
 191                 dev = udev_device_new_from_syspath(udev, syspath);
 192
 193                 udev_handle_dev_action(dev, "add");
 194
 195                 udev_device_unref(dev);
 196         }
 197
 198         udev_enumerate_unref(enumerate);
 199         return 0;
 200
 201 fail:
 202         udev_enumerate_unref(enumerate);
 203         return -1;
 204 }
 205
 206 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 207 {
 208         int result;
 209         struct udev_monitor *m;
 210
 211         *monitor = NULL;
 212         m = udev_monitor_new_from_netlink(udev, "udev");
 213
 214         if (!m) {
 215                 pb_log("udev_monitor_new_from_netlink failed\n");
 216                 goto out_err;
 217         }
 218
 219         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 220                 NULL);
 221
 222         if (result) {
 223                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 224                 goto out_err;
 225         }
 226
 227         result = udev_monitor_enable_receiving(m);
 228
 229         if (result) {
 230                 pb_log("udev_monitor_enable_receiving failed\n");
 231                 goto out_err;
 232         }
 233
 234         *monitor = m;
 235         return 0;
 236
 237 out_err:
 238         udev_monitor_unref(m);
 239         return -1;
 240 }
 241
 242 /*
 243  * udev_process - waiter callback for monitor netlink.
 244  */
 245
 246 static int udev_process(void *arg)
 247 {
 248         struct udev_monitor *monitor = arg;
 249         struct udev_device *dev;
 250         const char *action;
 251         int result;
 252
 253         dev = udev_monitor_receive_device(monitor);
 254
 255         if (!dev) {
 256                 pb_log("udev_monitor_receive_device failed\n");
 257                 return -1;
 258         }
 259
 260         action = udev_device_get_action(dev);
 261
 262         if (!action) {
 263                 pb_log("udev_device_get_action failed\n");
 264                 goto fail;
 265         }
 266
 267         result = udev_handle_dev_action(dev, action);
 268
 269         udev_device_unref(dev);
 270         return result;
 271
 272 fail:
 273         udev_device_unref(dev);
 274         return -1;
 275 }
 276
 277 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 278         int __attribute__((unused)) priority, const char *file, int line,
 279         const char *fn, const char *format, va_list args)
 280 {
 281       pb_log("libudev: %s %s:%d: ", fn, file, line);
 282       vfprintf(pb_log_get_stream(), format, args);
 283 }
 284
 285 struct pb_udev *udev_init(struct waitset *waitset,
 286         struct device_handler *handler)
 287 {
 288         int result;
 289         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 290
 291         talloc_set_destructor(udev, udev_destructor);
 292         udev->handler = handler;
 293
 294         udev->udev = udev_new();
 295
 296         if (!udev->udev) {
 297                 pb_log("udev_new failed\n");
 298                 goto fail_new;
 299         }
 300
 301         udev_set_userdata(udev->udev, udev);
 302
 303         udev_set_log_fn(udev->udev, udev_log_fn);
 304
 305         result = udev_enumerate(udev->udev);
 306
 307         if (result)
 308                 goto fail_enumerate;
 309
 310         result = udev_setup_monitor(udev->udev, &udev->monitor);
 311
 312         if (result)
 313                 goto fail_monitor;
 314
 315         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 316                 udev_process, udev->monitor);
 317
 318         pb_debug("%s: waiting on udev\n", __func__);
 319
 320         return udev;
 321
 322 fail_monitor:
 323 fail_enumerate:
 324         udev_unref(udev->udev);
 325 fail_new:
 326         talloc_free(udev);
 327         return NULL;
 328 }
 329
 330 void udev_destroy(struct pb_udev *udev)
 331 {
 332         talloc_free(udev);
 333 }