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