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 *serial;
  74         const char *path;
  75         const char *name;
  76         const char *prop;
  77
  78         name = udev_device_get_sysname(dev);
  79         if (!name) {
  80                 pb_debug("udev_device_get_sysname failed\n");
  81                 return -1;
  82         }
  83
  84         typestr = udev_device_get_devtype(dev);
  85         if (!typestr) {
  86                 pb_debug("udev_device_get_devtype failed\n");
  87                 return -1;
  88         }
  89
  90         if (!(!strcmp(typestr, "disk") || !strcmp(typestr, "partition"))) {
  91                 pb_debug("SKIP %s: invalid type %s\n", name, typestr);
  92                 return 0;
  93         }
  94
  95         path = udev_device_get_devpath(dev);
  96         if (path && (strstr(path, "virtual/block/loop")
  97                         || strstr(path, "virtual/block/ram"))) {
  98                 pb_debug("SKIP: %s: ignored (path=%s)\n", name, path);
  99                 return 0;
 100         }
 101
 102         /* We have enough info to create the device and start discovery */
 103         ddev = device_lookup_by_id(udev->handler, name);
 104         if (ddev) {
 105                 pb_debug("device %s is already present?\n", name);
 106                 return -1;
 107         }
 108
 109         /* we may also see multipath devices; same dev nodes (hence id), but
 110          * different serial numbers */
 111         serial = udev_device_get_property_value(dev, "ID_SERIAL");
 112         if (serial && device_lookup_by_serial(udev->handler, serial))
 113                 return -1;
 114
 115         ddev = discover_device_create(udev->handler, name);
 116
 117         ddev->device_path = udev_device_get_devnode(dev);
 118         prop = udev_device_get_property_value(dev, "ID_FS_UUID");
 119         if (prop)
 120                 ddev->uuid = talloc_strdup(ddev, prop);
 121         prop = udev_device_get_property_value(dev, "ID_FS_LABEL");
 122         if (prop)
 123                 ddev->label = talloc_strdup(ddev, prop);
 124         ddev->device->type = DEVICE_TYPE_DISK;
 125
 126         udev_setup_device_params(dev, ddev);
 127
 128         device_handler_discover(udev->handler, ddev, CONF_METHOD_LOCAL_FILE);
 129
 130         return 0;
 131 }
 132
 133 static int udev_handle_dev_remove(struct pb_udev *udev, struct udev_device *dev)
 134 {
 135         struct discover_device *ddev;
 136         const char *name;
 137
 138         name = udev_device_get_sysname(dev);
 139         if (!name) {
 140                 pb_debug("udev_device_get_sysname failed\n");
 141                 return -1;
 142         }
 143
 144         ddev = device_lookup_by_id(udev->handler, name);
 145         if (!ddev)
 146                 return 0;
 147
 148         device_handler_remove(udev->handler, ddev);
 149
 150         return 0;
 151 }
 152 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
 153 {
 154         struct pb_udev *udev = udev_get_userdata(udev_device_get_udev(dev));
 155
 156         if (!strcmp(action, "add"))
 157                 return udev_handle_dev_add(udev, dev);
 158
 159         else if (!strcmp(action, "remove"))
 160                 return udev_handle_dev_remove(udev, dev);
 161
 162         return 0;
 163 }
 164
 165 static int udev_enumerate(struct udev *udev)
 166 {
 167         int result;
 168         struct udev_list_entry *list, *entry;
 169         struct udev_enumerate *enumerate;
 170
 171         enumerate = udev_enumerate_new(udev);
 172
 173         if (!enumerate) {
 174                 pb_log("udev_enumerate_new failed\n");
 175                 return -1;
 176         }
 177
 178         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 179
 180         if (result) {
 181                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 182                 goto fail;
 183         }
 184
 185         udev_enumerate_scan_devices(enumerate);
 186
 187         list = udev_enumerate_get_list_entry(enumerate);
 188
 189         if (!list) {
 190                 pb_log("udev_enumerate_get_list_entry failed\n");
 191                 goto fail;
 192         }
 193
 194         udev_list_entry_foreach(entry, list) {
 195                 const char *syspath;
 196                 struct udev_device *dev;
 197
 198                 syspath = udev_list_entry_get_name(entry);
 199                 dev = udev_device_new_from_syspath(udev, syspath);
 200
 201                 udev_handle_dev_action(dev, "add");
 202
 203                 udev_device_unref(dev);
 204         }
 205
 206         udev_enumerate_unref(enumerate);
 207         return 0;
 208
 209 fail:
 210         udev_enumerate_unref(enumerate);
 211         return -1;
 212 }
 213
 214 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 215 {
 216         int result;
 217         struct udev_monitor *m;
 218
 219         *monitor = NULL;
 220         m = udev_monitor_new_from_netlink(udev, "udev");
 221
 222         if (!m) {
 223                 pb_log("udev_monitor_new_from_netlink failed\n");
 224                 goto out_err;
 225         }
 226
 227         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 228                 NULL);
 229
 230         if (result) {
 231                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 232                 goto out_err;
 233         }
 234
 235         result = udev_monitor_enable_receiving(m);
 236
 237         if (result) {
 238                 pb_log("udev_monitor_enable_receiving failed\n");
 239                 goto out_err;
 240         }
 241
 242         *monitor = m;
 243         return 0;
 244
 245 out_err:
 246         udev_monitor_unref(m);
 247         return -1;
 248 }
 249
 250 /*
 251  * udev_process - waiter callback for monitor netlink.
 252  */
 253
 254 static int udev_process(void *arg)
 255 {
 256         struct udev_monitor *monitor = arg;
 257         struct udev_device *dev;
 258         const char *action;
 259         int result;
 260
 261         dev = udev_monitor_receive_device(monitor);
 262
 263         if (!dev) {
 264                 pb_log("udev_monitor_receive_device failed\n");
 265                 return -1;
 266         }
 267
 268         action = udev_device_get_action(dev);
 269
 270         if (!action) {
 271                 pb_log("udev_device_get_action failed\n");
 272                 goto fail;
 273         }
 274
 275         result = udev_handle_dev_action(dev, action);
 276
 277         udev_device_unref(dev);
 278         return result;
 279
 280 fail:
 281         udev_device_unref(dev);
 282         return -1;
 283 }
 284
 285 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 286         int __attribute__((unused)) priority, const char *file, int line,
 287         const char *fn, const char *format, va_list args)
 288 {
 289       pb_log("libudev: %s %s:%d: ", fn, file, line);
 290       vfprintf(pb_log_get_stream(), format, args);
 291 }
 292
 293 struct pb_udev *udev_init(struct waitset *waitset,
 294         struct device_handler *handler)
 295 {
 296         int result;
 297         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 298
 299         talloc_set_destructor(udev, udev_destructor);
 300         udev->handler = handler;
 301
 302         udev->udev = udev_new();
 303
 304         if (!udev->udev) {
 305                 pb_log("udev_new failed\n");
 306                 goto fail_new;
 307         }
 308
 309         udev_set_userdata(udev->udev, udev);
 310
 311         udev_set_log_fn(udev->udev, udev_log_fn);
 312
 313         result = udev_enumerate(udev->udev);
 314
 315         if (result)
 316                 goto fail_enumerate;
 317
 318         result = udev_setup_monitor(udev->udev, &udev->monitor);
 319
 320         if (result)
 321                 goto fail_monitor;
 322
 323         waiter_register_io(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 324                 udev_process, udev->monitor);
 325
 326         pb_log("%s: waiting on udev\n", __func__);
 327
 328         return udev;
 329
 330 fail_monitor:
 331 fail_enumerate:
 332         udev_unref(udev->udev);
 333 fail_new:
 334         talloc_free(udev);
 335         return NULL;
 336 }
 337
 338 void udev_destroy(struct pb_udev *udev)
 339 {
 340         talloc_free(udev);
 341 }