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 <talloc/talloc.h>
  17 #include <waiter/waiter.h>
  18 #include <system/system.h>
  19
  20 #include "event.h"
  21 #include "udev.h"
  22 #include "pb-discover.h"
  23 #include "device-handler.h"
  24
  25 #if defined(DEBUG)
  26 #define DBG(fmt, args...) pb_log("DBG: " fmt, ## args)
  27 #define DBGS(fmt, args...) \
  28         pb_log("DBG:%s:%d: " fmt, __func__, __LINE__, ## args)
  29 #else
  30 #define DBG(fmt, args...)
  31 #define DBGS(fmt, args...)
  32 #endif
  33
  34 struct pb_udev {
  35         struct udev *udev;
  36         struct udev_monitor *monitor;
  37         struct device_handler *handler;
  38 };
  39
  40 static int udev_destructor(void *p)
  41 {
  42         struct pb_udev *udev = p;
  43
  44         udev_monitor_unref(udev->monitor);
  45         udev->monitor = NULL;
  46
  47         udev_unref(udev->udev);
  48         udev->udev = NULL;
  49
  50         return 0;
  51 }
  52
  53 static void udev_setup_event_params(struct udev_device *dev,
  54                 struct event *event)
  55 {
  56         struct udev_list_entry *list, *entry;
  57
  58         list = udev_device_get_properties_list_entry(dev);
  59         if (!list)
  60                 return;
  61
  62         udev_list_entry_foreach(entry, list) {
  63                 DBG("property: %s - %s\n",
  64                         udev_list_entry_get_name(entry),
  65                         udev_device_get_property_value(dev,
  66                                 udev_list_entry_get_name(entry)));
  67
  68                 event_set_param(event,udev_list_entry_get_name(entry),
  69                                 udev_list_entry_get_value(entry));
  70
  71         }
  72 }
  73
  74 static int udev_handle_dev_action(struct udev_device *dev, const char *action)
  75 {
  76         const char *devtype;
  77         const char *devpath;
  78         const char *devnode;
  79         struct pb_udev *udev;
  80         struct event *event;
  81         enum event_action eva = 0;
  82
  83         assert(dev);
  84         assert(action);
  85
  86         devtype = udev_device_get_devtype(dev); /* DEVTYPE */
  87
  88         if (!devtype) {
  89                 pb_log("udev_device_get_devtype failed\n");
  90                 return -1;
  91         }
  92
  93         devpath = udev_device_get_devpath(dev); /* DEVPATH */
  94
  95         if (!devpath) {
  96                 pb_log("udev_device_get_devpath failed\n");
  97                 return -1;
  98         }
  99
 100         devnode = udev_device_get_devnode(dev); /* DEVNAME */
 101
 102         if (!devnode) {
 103                 pb_log("udev_device_get_devnode failed\n");
 104                 return -1;
 105         }
 106
 107         /* Ignore non disk or partition, ram, loop. */
 108
 109         if (!(strstr(devtype, "disk") || strstr(devtype, "partition"))
 110                 || strstr(devpath, "virtual/block/loop")
 111                 || strstr(devpath, "virtual/block/ram")) {
 112                 pb_log("SKIP: %s - %s\n", devtype, devnode);
 113                 return 0;
 114         }
 115
 116         if (!strcmp(action, "add")) {
 117                 pb_log("ADD: %s - %s\n", devtype, devnode);
 118                 eva = EVENT_ACTION_ADD;
 119         } else if (!strcmp(action, "remove")) {
 120                 pb_log("REMOVE: %s - %s\n", devtype, devnode);
 121                 eva = EVENT_ACTION_REMOVE;
 122         } else {
 123                 pb_log("SKIP: %s: %s - %s\n", action, devtype, devnode);
 124                 return 0;
 125         }
 126
 127         event = talloc(NULL, struct event);
 128
 129         event->type = EVENT_TYPE_UDEV;
 130         event->action = eva;
 131         event->device = devnode;
 132
 133         event->n_params = 0;
 134         event->params = NULL;
 135         event_set_param(event, "DEVNAME", devnode);
 136
 137         udev_setup_event_params(dev, event);
 138
 139         udev = udev_get_userdata(udev_device_get_udev(dev));
 140         assert(udev);
 141
 142         device_handler_event(udev->handler, event);
 143
 144         talloc_free(event);
 145         return 0;
 146 }
 147
 148 static int udev_enumerate(struct udev *udev)
 149 {
 150         int result;
 151         struct udev_list_entry *list, *entry;
 152         struct udev_enumerate *enumerate;
 153
 154         enumerate = udev_enumerate_new(udev);
 155
 156         if (!enumerate) {
 157                 pb_log("udev_enumerate_new failed\n");
 158                 return -1;
 159         }
 160
 161         result = udev_enumerate_add_match_subsystem(enumerate, "block");
 162
 163         if (result) {
 164                 pb_log("udev_enumerate_add_match_subsystem failed\n");
 165                 goto fail;
 166         }
 167
 168         udev_enumerate_scan_devices(enumerate);
 169
 170         list = udev_enumerate_get_list_entry(enumerate);
 171
 172         if (!list) {
 173                 pb_log("udev_enumerate_get_list_entry failed\n");
 174                 goto fail;
 175         }
 176
 177         udev_list_entry_foreach(entry, list) {
 178                 const char *syspath;
 179                 struct udev_device *dev;
 180
 181                 syspath = udev_list_entry_get_name(entry);
 182                 dev = udev_device_new_from_syspath(udev, syspath);
 183
 184                 udev_handle_dev_action(dev, "add");
 185
 186                 udev_device_unref(dev);
 187         }
 188
 189         udev_enumerate_unref(enumerate);
 190         return 0;
 191
 192 fail:
 193         udev_enumerate_unref(enumerate);
 194         return -1;
 195 }
 196
 197 static int udev_setup_monitor(struct udev *udev, struct udev_monitor **monitor)
 198 {
 199         int result;
 200         struct udev_monitor *m;
 201
 202         *monitor = NULL;
 203         m = udev_monitor_new_from_netlink(udev, "udev");
 204
 205         if (!m) {
 206                 pb_log("udev_monitor_new_from_netlink failed\n");
 207                 goto out_err;
 208         }
 209
 210         result = udev_monitor_filter_add_match_subsystem_devtype(m, "block",
 211                 NULL);
 212
 213         if (result) {
 214                 pb_log("udev_monitor_filter_add_match_subsystem_devtype failed\n");
 215                 goto out_err;
 216         }
 217
 218         result = udev_monitor_enable_receiving(m);
 219
 220         if (result) {
 221                 pb_log("udev_monitor_enable_receiving failed\n");
 222                 goto out_err;
 223         }
 224
 225         *monitor = m;
 226         return 0;
 227
 228 out_err:
 229         udev_monitor_unref(m);
 230         return -1;
 231 }
 232
 233 /*
 234  * udev_process - waiter callback for monitor netlink.
 235  */
 236
 237 static int udev_process(void *arg)
 238 {
 239         struct udev_monitor *monitor = arg;
 240         struct udev_device *dev;
 241         const char *action;
 242         int result;
 243
 244         dev = udev_monitor_receive_device(monitor);
 245
 246         if (!dev) {
 247                 pb_log("udev_monitor_receive_device failed\n");
 248                 return -1;
 249         }
 250
 251         action = udev_device_get_action(dev);
 252
 253         if (!action) {
 254                 pb_log("udev_device_get_action failed\n");
 255                 goto fail;
 256         }
 257
 258         result = udev_handle_dev_action(dev, action);
 259
 260         udev_device_unref(dev);
 261         return result;
 262
 263 fail:
 264         udev_device_unref(dev);
 265         return -1;
 266 }
 267
 268 static void udev_log_fn(struct udev __attribute__((unused)) *udev,
 269         int __attribute__((unused)) priority, const char *file, int line,
 270         const char *fn, const char *format, va_list args)
 271 {
 272       pb_log("libudev: %s %s:%d: ", fn, file, line);
 273       vfprintf(pb_log_get_stream(), format, args);
 274 }
 275
 276 struct pb_udev *udev_init(struct waitset *waitset,
 277         struct device_handler *handler)
 278 {
 279         int result;
 280         struct pb_udev *udev = talloc(NULL, struct pb_udev);
 281
 282         talloc_set_destructor(udev, udev_destructor);
 283         udev->handler = handler;
 284
 285         udev->udev = udev_new();
 286
 287         if (!udev->udev) {
 288                 pb_log("udev_new failed\n");
 289                 goto fail_new;
 290         }
 291
 292         udev_set_userdata(udev->udev, udev);
 293
 294         udev_set_log_fn(udev->udev, udev_log_fn);
 295
 296         result = udev_enumerate(udev->udev);
 297
 298         if (result)
 299                 goto fail_enumerate;
 300
 301         result = udev_setup_monitor(udev->udev, &udev->monitor);
 302
 303         if (result)
 304                 goto fail_monitor;
 305
 306         waiter_register(waitset, udev_monitor_get_fd(udev->monitor), WAIT_IN,
 307                 udev_process, udev->monitor);
 308
 309         pb_log("%s: waiting on udev\n", __func__);
 310
 311         return udev;
 312
 313 fail_monitor:
 314 fail_enumerate:
 315         udev_unref(udev->udev);
 316 fail_new:
 317         talloc_free(udev);
 318         return NULL;
 319 }
 320
 321 void udev_destroy(struct pb_udev *udev)
 322 {
 323         talloc_free(udev);
 324 }