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