net/switchdev/switchdev.c

   1 /*
   2  * net/switchdev/switchdev.c - Switch device API
   3  * Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
   4  * Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/types.h>
  14 #include <linux/init.h>
  15 #include <linux/mutex.h>
  16 #include <linux/notifier.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/if_bridge.h>
  20 #include <linux/list.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/if_vlan.h>
  23 #include <linux/rtnetlink.h>
  24 #include <net/switchdev.h>
  25
  26 static LIST_HEAD(deferred);
  27 static DEFINE_SPINLOCK(deferred_lock);
  28
  29 typedef void switchdev_deferred_func_t(struct net_device *dev,
  30                                        const void *data);
  31
  32 struct switchdev_deferred_item {
  33         struct list_head list;
  34         struct net_device *dev;
  35         switchdev_deferred_func_t *func;
  36         unsigned long data[0];
  37 };
  38
  39 static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
  40 {
  41         struct switchdev_deferred_item *dfitem;
  42
  43         spin_lock_bh(&deferred_lock);
  44         if (list_empty(&deferred)) {
  45                 dfitem = NULL;
  46                 goto unlock;
  47         }
  48         dfitem = list_first_entry(&deferred,
  49                                   struct switchdev_deferred_item, list);
  50         list_del(&dfitem->list);
  51 unlock:
  52         spin_unlock_bh(&deferred_lock);
  53         return dfitem;
  54 }
  55
  56 /**
  57  *      switchdev_deferred_process - Process ops in deferred queue
  58  *
  59  *      Called to flush the ops currently queued in deferred ops queue.
  60  *      rtnl_lock must be held.
  61  */
  62 void switchdev_deferred_process(void)
  63 {
  64         struct switchdev_deferred_item *dfitem;
  65
  66         ASSERT_RTNL();
  67
  68         while ((dfitem = switchdev_deferred_dequeue())) {
  69                 dfitem->func(dfitem->dev, dfitem->data);
  70                 dev_put(dfitem->dev);
  71                 kfree(dfitem);
  72         }
  73 }
  74 EXPORT_SYMBOL_GPL(switchdev_deferred_process);
  75
  76 static void switchdev_deferred_process_work(struct work_struct *work)
  77 {
  78         rtnl_lock();
  79         switchdev_deferred_process();
  80         rtnl_unlock();
  81 }
  82
  83 static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
  84
  85 static int switchdev_deferred_enqueue(struct net_device *dev,
  86                                       const void *data, size_t data_len,
  87                                       switchdev_deferred_func_t *func)
  88 {
  89         struct switchdev_deferred_item *dfitem;
  90
  91         dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
  92         if (!dfitem)
  93                 return -ENOMEM;
  94         dfitem->dev = dev;
  95         dfitem->func = func;
  96         memcpy(dfitem->data, data, data_len);
  97         dev_hold(dev);
  98         spin_lock_bh(&deferred_lock);
  99         list_add_tail(&dfitem->list, &deferred);
 100         spin_unlock_bh(&deferred_lock);
 101         schedule_work(&deferred_process_work);
 102         return 0;
 103 }
 104
 105 static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
 106                                       struct net_device *dev,
 107                                       const struct switchdev_attr *attr,
 108                                       struct switchdev_trans *trans)
 109 {
 110         int err;
 111         int rc;
 112
 113         struct switchdev_notifier_port_attr_info attr_info = {
 114                 .attr = attr,
 115                 .trans = trans,
 116                 .handled = false,
 117         };
 118
 119         rc = call_switchdev_blocking_notifiers(nt, dev,
 120                                                &attr_info.info, NULL);
 121         err = notifier_to_errno(rc);
 122         if (err) {
 123                 WARN_ON(!attr_info.handled);
 124                 return err;
 125         }
 126
 127         if (!attr_info.handled)
 128                 return -EOPNOTSUPP;
 129
 130         return 0;
 131 }
 132
 133 static int switchdev_port_attr_set_now(struct net_device *dev,
 134                                        const struct switchdev_attr *attr)
 135 {
 136         struct switchdev_trans trans;
 137         int err;
 138
 139         /* Phase I: prepare for attr set. Driver/device should fail
 140          * here if there are going to be issues in the commit phase,
 141          * such as lack of resources or support.  The driver/device
 142          * should reserve resources needed for the commit phase here,
 143          * but should not commit the attr.
 144          */
 145
 146         trans.ph_prepare = true;
 147         err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
 148                                          &trans);
 149         if (err)
 150                 return err;
 151
 152         /* Phase II: commit attr set.  This cannot fail as a fault
 153          * of driver/device.  If it does, it's a bug in the driver/device
 154          * because the driver said everythings was OK in phase I.
 155          */
 156
 157         trans.ph_prepare = false;
 158         err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
 159                                          &trans);
 160         WARN(err, "%s: Commit of attribute (id=%d) failed.\n",
 161              dev->name, attr->id);
 162
 163         return err;
 164 }
 165
 166 static void switchdev_port_attr_set_deferred(struct net_device *dev,
 167                                              const void *data)
 168 {
 169         const struct switchdev_attr *attr = data;
 170         int err;
 171
 172         err = switchdev_port_attr_set_now(dev, attr);
 173         if (err && err != -EOPNOTSUPP)
 174                 netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
 175                            err, attr->id);
 176         if (attr->complete)
 177                 attr->complete(dev, err, attr->complete_priv);
 178 }
 179
 180 static int switchdev_port_attr_set_defer(struct net_device *dev,
 181                                          const struct switchdev_attr *attr)
 182 {
 183         return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
 184                                           switchdev_port_attr_set_deferred);
 185 }
 186
 187 /**
 188  *      switchdev_port_attr_set - Set port attribute
 189  *
 190  *      @dev: port device
 191  *      @attr: attribute to set
 192  *
 193  *      Use a 2-phase prepare-commit transaction model to ensure
 194  *      system is not left in a partially updated state due to
 195  *      failure from driver/device.
 196  *
 197  *      rtnl_lock must be held and must not be in atomic section,
 198  *      in case SWITCHDEV_F_DEFER flag is not set.
 199  */
 200 int switchdev_port_attr_set(struct net_device *dev,
 201                             const struct switchdev_attr *attr)
 202 {
 203         if (attr->flags & SWITCHDEV_F_DEFER)
 204                 return switchdev_port_attr_set_defer(dev, attr);
 205         ASSERT_RTNL();
 206         return switchdev_port_attr_set_now(dev, attr);
 207 }
 208 EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
 209
 210 static size_t switchdev_obj_size(const struct switchdev_obj *obj)
 211 {
 212         switch (obj->id) {
 213         case SWITCHDEV_OBJ_ID_PORT_VLAN:
 214                 return sizeof(struct switchdev_obj_port_vlan);
 215         case SWITCHDEV_OBJ_ID_PORT_MDB:
 216                 return sizeof(struct switchdev_obj_port_mdb);
 217         case SWITCHDEV_OBJ_ID_HOST_MDB:
 218                 return sizeof(struct switchdev_obj_port_mdb);
 219         default:
 220                 BUG();
 221         }
 222         return 0;
 223 }
 224
 225 static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
 226                                      struct net_device *dev,
 227                                      const struct switchdev_obj *obj,
 228                                      struct switchdev_trans *trans,
 229                                      struct netlink_ext_ack *extack)
 230 {
 231         int rc;
 232         int err;
 233
 234         struct switchdev_notifier_port_obj_info obj_info = {
 235                 .obj = obj,
 236                 .trans = trans,
 237                 .handled = false,
 238         };
 239
 240         rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
 241         err = notifier_to_errno(rc);
 242         if (err) {
 243                 WARN_ON(!obj_info.handled);
 244                 return err;
 245         }
 246         if (!obj_info.handled)
 247                 return -EOPNOTSUPP;
 248         return 0;
 249 }
 250
 251 static int switchdev_port_obj_add_now(struct net_device *dev,
 252                                       const struct switchdev_obj *obj,
 253                                       struct netlink_ext_ack *extack)
 254 {
 255         struct switchdev_trans trans;
 256         int err;
 257
 258         ASSERT_RTNL();
 259
 260         /* Phase I: prepare for obj add. Driver/device should fail
 261          * here if there are going to be issues in the commit phase,
 262          * such as lack of resources or support.  The driver/device
 263          * should reserve resources needed for the commit phase here,
 264          * but should not commit the obj.
 265          */
 266
 267         trans.ph_prepare = true;
 268         err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 269                                         dev, obj, &trans, extack);
 270         if (err)
 271                 return err;
 272
 273         /* Phase II: commit obj add.  This cannot fail as a fault
 274          * of driver/device.  If it does, it's a bug in the driver/device
 275          * because the driver said everythings was OK in phase I.
 276          */
 277
 278         trans.ph_prepare = false;
 279         err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 280                                         dev, obj, &trans, extack);
 281         WARN(err, "%s: Commit of object (id=%d) failed.\n", dev->name, obj->id);
 282
 283         return err;
 284 }
 285
 286 static void switchdev_port_obj_add_deferred(struct net_device *dev,
 287                                             const void *data)
 288 {
 289         const struct switchdev_obj *obj = data;
 290         int err;
 291
 292         err = switchdev_port_obj_add_now(dev, obj, NULL);
 293         if (err && err != -EOPNOTSUPP)
 294                 netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
 295                            err, obj->id);
 296         if (obj->complete)
 297                 obj->complete(dev, err, obj->complete_priv);
 298 }
 299
 300 static int switchdev_port_obj_add_defer(struct net_device *dev,
 301                                         const struct switchdev_obj *obj)
 302 {
 303         return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 304                                           switchdev_port_obj_add_deferred);
 305 }
 306
 307 /**
 308  *      switchdev_port_obj_add - Add port object
 309  *
 310  *      @dev: port device
 311  *      @id: object ID
 312  *      @obj: object to add
 313  *
 314  *      Use a 2-phase prepare-commit transaction model to ensure
 315  *      system is not left in a partially updated state due to
 316  *      failure from driver/device.
 317  *
 318  *      rtnl_lock must be held and must not be in atomic section,
 319  *      in case SWITCHDEV_F_DEFER flag is not set.
 320  */
 321 int switchdev_port_obj_add(struct net_device *dev,
 322                            const struct switchdev_obj *obj,
 323                            struct netlink_ext_ack *extack)
 324 {
 325         if (obj->flags & SWITCHDEV_F_DEFER)
 326                 return switchdev_port_obj_add_defer(dev, obj);
 327         ASSERT_RTNL();
 328         return switchdev_port_obj_add_now(dev, obj, extack);
 329 }
 330 EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
 331
 332 static int switchdev_port_obj_del_now(struct net_device *dev,
 333                                       const struct switchdev_obj *obj)
 334 {
 335         return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
 336                                          dev, obj, NULL, NULL);
 337 }
 338
 339 static void switchdev_port_obj_del_deferred(struct net_device *dev,
 340                                             const void *data)
 341 {
 342         const struct switchdev_obj *obj = data;
 343         int err;
 344
 345         err = switchdev_port_obj_del_now(dev, obj);
 346         if (err && err != -EOPNOTSUPP)
 347                 netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
 348                            err, obj->id);
 349         if (obj->complete)
 350                 obj->complete(dev, err, obj->complete_priv);
 351 }
 352
 353 static int switchdev_port_obj_del_defer(struct net_device *dev,
 354                                         const struct switchdev_obj *obj)
 355 {
 356         return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 357                                           switchdev_port_obj_del_deferred);
 358 }
 359
 360 /**
 361  *      switchdev_port_obj_del - Delete port object
 362  *
 363  *      @dev: port device
 364  *      @id: object ID
 365  *      @obj: object to delete
 366  *
 367  *      rtnl_lock must be held and must not be in atomic section,
 368  *      in case SWITCHDEV_F_DEFER flag is not set.
 369  */
 370 int switchdev_port_obj_del(struct net_device *dev,
 371                            const struct switchdev_obj *obj)
 372 {
 373         if (obj->flags & SWITCHDEV_F_DEFER)
 374                 return switchdev_port_obj_del_defer(dev, obj);
 375         ASSERT_RTNL();
 376         return switchdev_port_obj_del_now(dev, obj);
 377 }
 378 EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
 379
 380 static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
 381 static BLOCKING_NOTIFIER_HEAD(switchdev_blocking_notif_chain);
 382
 383 /**
 384  *      register_switchdev_notifier - Register notifier
 385  *      @nb: notifier_block
 386  *
 387  *      Register switch device notifier.
 388  */
 389 int register_switchdev_notifier(struct notifier_block *nb)
 390 {
 391         return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
 392 }
 393 EXPORT_SYMBOL_GPL(register_switchdev_notifier);
 394
 395 /**
 396  *      unregister_switchdev_notifier - Unregister notifier
 397  *      @nb: notifier_block
 398  *
 399  *      Unregister switch device notifier.
 400  */
 401 int unregister_switchdev_notifier(struct notifier_block *nb)
 402 {
 403         return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
 404 }
 405 EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
 406
 407 /**
 408  *      call_switchdev_notifiers - Call notifiers
 409  *      @val: value passed unmodified to notifier function
 410  *      @dev: port device
 411  *      @info: notifier information data
 412  *
 413  *      Call all network notifier blocks.
 414  */
 415 int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
 416                              struct switchdev_notifier_info *info,
 417                              struct netlink_ext_ack *extack)
 418 {
 419         info->dev = dev;
 420         info->extack = extack;
 421         return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
 422 }
 423 EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
 424
 425 int register_switchdev_blocking_notifier(struct notifier_block *nb)
 426 {
 427         struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
 428
 429         return blocking_notifier_chain_register(chain, nb);
 430 }
 431 EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);
 432
 433 int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
 434 {
 435         struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
 436
 437         return blocking_notifier_chain_unregister(chain, nb);
 438 }
 439 EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);
 440
 441 int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
 442                                       struct switchdev_notifier_info *info,
 443                                       struct netlink_ext_ack *extack)
 444 {
 445         info->dev = dev;
 446         info->extack = extack;
 447         return blocking_notifier_call_chain(&switchdev_blocking_notif_chain,
 448                                             val, info);
 449 }
 450 EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
 451
 452 static int __switchdev_handle_port_obj_add(struct net_device *dev,
 453                         struct switchdev_notifier_port_obj_info *port_obj_info,
 454                         bool (*check_cb)(const struct net_device *dev),
 455                         int (*add_cb)(struct net_device *dev,
 456                                       const struct switchdev_obj *obj,
 457                                       struct switchdev_trans *trans,
 458                                       struct netlink_ext_ack *extack))
 459 {
 460         struct netlink_ext_ack *extack;
 461         struct net_device *lower_dev;
 462         struct list_head *iter;
 463         int err = -EOPNOTSUPP;
 464
 465         extack = switchdev_notifier_info_to_extack(&port_obj_info->info);
 466
 467         if (check_cb(dev)) {
 468                 /* This flag is only checked if the return value is success. */
 469                 port_obj_info->handled = true;
 470                 return add_cb(dev, port_obj_info->obj, port_obj_info->trans,
 471                               extack);
 472         }
 473
 474         /* Switch ports might be stacked under e.g. a LAG. Ignore the
 475          * unsupported devices, another driver might be able to handle them. But
 476          * propagate to the callers any hard errors.
 477          *
 478          * If the driver does its own bookkeeping of stacked ports, it's not
 479          * necessary to go through this helper.
 480          */
 481         netdev_for_each_lower_dev(dev, lower_dev, iter) {
 482                 err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
 483                                                       check_cb, add_cb);
 484                 if (err && err != -EOPNOTSUPP)
 485                         return err;
 486         }
 487
 488         return err;
 489 }
 490
 491 int switchdev_handle_port_obj_add(struct net_device *dev,
 492                         struct switchdev_notifier_port_obj_info *port_obj_info,
 493                         bool (*check_cb)(const struct net_device *dev),
 494                         int (*add_cb)(struct net_device *dev,
 495                                       const struct switchdev_obj *obj,
 496                                       struct switchdev_trans *trans,
 497                                       struct netlink_ext_ack *extack))
 498 {
 499         int err;
 500
 501         err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
 502                                               add_cb);
 503         if (err == -EOPNOTSUPP)
 504                 err = 0;
 505         return err;
 506 }
 507 EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);
 508
 509 static int __switchdev_handle_port_obj_del(struct net_device *dev,
 510                         struct switchdev_notifier_port_obj_info *port_obj_info,
 511                         bool (*check_cb)(const struct net_device *dev),
 512                         int (*del_cb)(struct net_device *dev,
 513                                       const struct switchdev_obj *obj))
 514 {
 515         struct net_device *lower_dev;
 516         struct list_head *iter;
 517         int err = -EOPNOTSUPP;
 518
 519         if (check_cb(dev)) {
 520                 /* This flag is only checked if the return value is success. */
 521                 port_obj_info->handled = true;
 522                 return del_cb(dev, port_obj_info->obj);
 523         }
 524
 525         /* Switch ports might be stacked under e.g. a LAG. Ignore the
 526          * unsupported devices, another driver might be able to handle them. But
 527          * propagate to the callers any hard errors.
 528          *
 529          * If the driver does its own bookkeeping of stacked ports, it's not
 530          * necessary to go through this helper.
 531          */
 532         netdev_for_each_lower_dev(dev, lower_dev, iter) {
 533                 err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
 534                                                       check_cb, del_cb);
 535                 if (err && err != -EOPNOTSUPP)
 536                         return err;
 537         }
 538
 539         return err;
 540 }
 541
 542 int switchdev_handle_port_obj_del(struct net_device *dev,
 543                         struct switchdev_notifier_port_obj_info *port_obj_info,
 544                         bool (*check_cb)(const struct net_device *dev),
 545                         int (*del_cb)(struct net_device *dev,
 546                                       const struct switchdev_obj *obj))
 547 {
 548         int err;
 549
 550         err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
 551                                               del_cb);
 552         if (err == -EOPNOTSUPP)
 553                 err = 0;
 554         return err;
 555 }
 556 EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
 557
 558 static int __switchdev_handle_port_attr_set(struct net_device *dev,
 559                         struct switchdev_notifier_port_attr_info *port_attr_info,
 560                         bool (*check_cb)(const struct net_device *dev),
 561                         int (*set_cb)(struct net_device *dev,
 562                                       const struct switchdev_attr *attr,
 563                                       struct switchdev_trans *trans))
 564 {
 565         struct net_device *lower_dev;
 566         struct list_head *iter;
 567         int err = -EOPNOTSUPP;
 568
 569         if (check_cb(dev)) {
 570                 port_attr_info->handled = true;
 571                 return set_cb(dev, port_attr_info->attr,
 572                               port_attr_info->trans);
 573         }
 574
 575         /* Switch ports might be stacked under e.g. a LAG. Ignore the
 576          * unsupported devices, another driver might be able to handle them. But
 577          * propagate to the callers any hard errors.
 578          *
 579          * If the driver does its own bookkeeping of stacked ports, it's not
 580          * necessary to go through this helper.
 581          */
 582         netdev_for_each_lower_dev(dev, lower_dev, iter) {
 583                 err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
 584                                                        check_cb, set_cb);
 585                 if (err && err != -EOPNOTSUPP)
 586                         return err;
 587         }
 588
 589         return err;
 590 }
 591
 592 int switchdev_handle_port_attr_set(struct net_device *dev,
 593                         struct switchdev_notifier_port_attr_info *port_attr_info,
 594                         bool (*check_cb)(const struct net_device *dev),
 595                         int (*set_cb)(struct net_device *dev,
 596                                       const struct switchdev_attr *attr,
 597                                       struct switchdev_trans *trans))
 598 {
 599         int err;
 600
 601         err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
 602                                                set_cb);
 603         if (err == -EOPNOTSUPP)
 604                 err = 0;
 605         return err;
 606 }
 607 EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);