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