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