linux/net/switchdev/switchdev.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * net/switchdev/switchdev.c - Switch device API
   4 * Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
   5 * Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/types.h>
  10#include <linux/init.h>
  11#include <linux/mutex.h>
  12#include <linux/notifier.h>
  13#include <linux/netdevice.h>
  14#include <linux/etherdevice.h>
  15#include <linux/if_bridge.h>
  16#include <linux/list.h>
  17#include <linux/workqueue.h>
  18#include <linux/if_vlan.h>
  19#include <linux/rtnetlink.h>
  20#include <net/switchdev.h>
  21
  22static LIST_HEAD(deferred);
  23static DEFINE_SPINLOCK(deferred_lock);
  24
  25typedef void switchdev_deferred_func_t(struct net_device *dev,
  26                                       const void *data);
  27
  28struct switchdev_deferred_item {
  29        struct list_head list;
  30        struct net_device *dev;
  31        switchdev_deferred_func_t *func;
  32        unsigned long data[];
  33};
  34
  35static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
  36{
  37        struct switchdev_deferred_item *dfitem;
  38
  39        spin_lock_bh(&deferred_lock);
  40        if (list_empty(&deferred)) {
  41                dfitem = NULL;
  42                goto unlock;
  43        }
  44        dfitem = list_first_entry(&deferred,
  45                                  struct switchdev_deferred_item, list);
  46        list_del(&dfitem->list);
  47unlock:
  48        spin_unlock_bh(&deferred_lock);
  49        return dfitem;
  50}
  51
  52/**
  53 *      switchdev_deferred_process - Process ops in deferred queue
  54 *
  55 *      Called to flush the ops currently queued in deferred ops queue.
  56 *      rtnl_lock must be held.
  57 */
  58void switchdev_deferred_process(void)
  59{
  60        struct switchdev_deferred_item *dfitem;
  61
  62        ASSERT_RTNL();
  63
  64        while ((dfitem = switchdev_deferred_dequeue())) {
  65                dfitem->func(dfitem->dev, dfitem->data);
  66                dev_put(dfitem->dev);
  67                kfree(dfitem);
  68        }
  69}
  70EXPORT_SYMBOL_GPL(switchdev_deferred_process);
  71
  72static void switchdev_deferred_process_work(struct work_struct *work)
  73{
  74        rtnl_lock();
  75        switchdev_deferred_process();
  76        rtnl_unlock();
  77}
  78
  79static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
  80
  81static int switchdev_deferred_enqueue(struct net_device *dev,
  82                                      const void *data, size_t data_len,
  83                                      switchdev_deferred_func_t *func)
  84{
  85        struct switchdev_deferred_item *dfitem;
  86
  87        dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
  88        if (!dfitem)
  89                return -ENOMEM;
  90        dfitem->dev = dev;
  91        dfitem->func = func;
  92        memcpy(dfitem->data, data, data_len);
  93        dev_hold(dev);
  94        spin_lock_bh(&deferred_lock);
  95        list_add_tail(&dfitem->list, &deferred);
  96        spin_unlock_bh(&deferred_lock);
  97        schedule_work(&deferred_process_work);
  98        return 0;
  99}
 100
 101static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
 102                                      struct net_device *dev,
 103                                      const struct switchdev_attr *attr,
 104                                      struct netlink_ext_ack *extack)
 105{
 106        int err;
 107        int rc;
 108
 109        struct switchdev_notifier_port_attr_info attr_info = {
 110                .attr = attr,
 111                .handled = false,
 112        };
 113
 114        rc = call_switchdev_blocking_notifiers(nt, dev,
 115                                               &attr_info.info, extack);
 116        err = notifier_to_errno(rc);
 117        if (err) {
 118                WARN_ON(!attr_info.handled);
 119                return err;
 120        }
 121
 122        if (!attr_info.handled)
 123                return -EOPNOTSUPP;
 124
 125        return 0;
 126}
 127
 128static int switchdev_port_attr_set_now(struct net_device *dev,
 129                                       const struct switchdev_attr *attr,
 130                                       struct netlink_ext_ack *extack)
 131{
 132        return switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
 133                                          extack);
 134}
 135
 136static void switchdev_port_attr_set_deferred(struct net_device *dev,
 137                                             const void *data)
 138{
 139        const struct switchdev_attr *attr = data;
 140        int err;
 141
 142        err = switchdev_port_attr_set_now(dev, attr, NULL);
 143        if (err && err != -EOPNOTSUPP)
 144                netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
 145                           err, attr->id);
 146        if (attr->complete)
 147                attr->complete(dev, err, attr->complete_priv);
 148}
 149
 150static int switchdev_port_attr_set_defer(struct net_device *dev,
 151                                         const struct switchdev_attr *attr)
 152{
 153        return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
 154                                          switchdev_port_attr_set_deferred);
 155}
 156
 157/**
 158 *      switchdev_port_attr_set - Set port attribute
 159 *
 160 *      @dev: port device
 161 *      @attr: attribute to set
 162 *      @extack: netlink extended ack, for error message propagation
 163 *
 164 *      rtnl_lock must be held and must not be in atomic section,
 165 *      in case SWITCHDEV_F_DEFER flag is not set.
 166 */
 167int switchdev_port_attr_set(struct net_device *dev,
 168                            const struct switchdev_attr *attr,
 169                            struct netlink_ext_ack *extack)
 170{
 171        if (attr->flags & SWITCHDEV_F_DEFER)
 172                return switchdev_port_attr_set_defer(dev, attr);
 173        ASSERT_RTNL();
 174        return switchdev_port_attr_set_now(dev, attr, extack);
 175}
 176EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
 177
 178static size_t switchdev_obj_size(const struct switchdev_obj *obj)
 179{
 180        switch (obj->id) {
 181        case SWITCHDEV_OBJ_ID_PORT_VLAN:
 182                return sizeof(struct switchdev_obj_port_vlan);
 183        case SWITCHDEV_OBJ_ID_PORT_MDB:
 184                return sizeof(struct switchdev_obj_port_mdb);
 185        case SWITCHDEV_OBJ_ID_HOST_MDB:
 186                return sizeof(struct switchdev_obj_port_mdb);
 187        default:
 188                BUG();
 189        }
 190        return 0;
 191}
 192
 193static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
 194                                     struct net_device *dev,
 195                                     const struct switchdev_obj *obj,
 196                                     struct netlink_ext_ack *extack)
 197{
 198        int rc;
 199        int err;
 200
 201        struct switchdev_notifier_port_obj_info obj_info = {
 202                .obj = obj,
 203                .handled = false,
 204        };
 205
 206        rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
 207        err = notifier_to_errno(rc);
 208        if (err) {
 209                WARN_ON(!obj_info.handled);
 210                return err;
 211        }
 212        if (!obj_info.handled)
 213                return -EOPNOTSUPP;
 214        return 0;
 215}
 216
 217static void switchdev_port_obj_add_deferred(struct net_device *dev,
 218                                            const void *data)
 219{
 220        const struct switchdev_obj *obj = data;
 221        int err;
 222
 223        ASSERT_RTNL();
 224        err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 225                                        dev, obj, NULL);
 226        if (err && err != -EOPNOTSUPP)
 227                netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
 228                           err, obj->id);
 229        if (obj->complete)
 230                obj->complete(dev, err, obj->complete_priv);
 231}
 232
 233static int switchdev_port_obj_add_defer(struct net_device *dev,
 234                                        const struct switchdev_obj *obj)
 235{
 236        return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 237                                          switchdev_port_obj_add_deferred);
 238}
 239
 240/**
 241 *      switchdev_port_obj_add - Add port object
 242 *
 243 *      @dev: port device
 244 *      @obj: object to add
 245 *      @extack: netlink extended ack
 246 *
 247 *      rtnl_lock must be held and must not be in atomic section,
 248 *      in case SWITCHDEV_F_DEFER flag is not set.
 249 */
 250int switchdev_port_obj_add(struct net_device *dev,
 251                           const struct switchdev_obj *obj,
 252                           struct netlink_ext_ack *extack)
 253{
 254        if (obj->flags & SWITCHDEV_F_DEFER)
 255                return switchdev_port_obj_add_defer(dev, obj);
 256        ASSERT_RTNL();
 257        return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 258                                         dev, obj, extack);
 259}
 260EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
 261
 262static int switchdev_port_obj_del_now(struct net_device *dev,
 263                                      const struct switchdev_obj *obj)
 264{
 265        return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
 266                                         dev, obj, NULL);
 267}
 268
 269static void switchdev_port_obj_del_deferred(struct net_device *dev,
 270                                            const void *data)
 271{
 272        const struct switchdev_obj *obj = data;
 273        int err;
 274
 275        err = switchdev_port_obj_del_now(dev, obj);
 276        if (err && err != -EOPNOTSUPP)
 277                netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
 278                           err, obj->id);
 279        if (obj->complete)
 280                obj->complete(dev, err, obj->complete_priv);
 281}
 282
 283static int switchdev_port_obj_del_defer(struct net_device *dev,
 284                                        const struct switchdev_obj *obj)
 285{
 286        return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 287                                          switchdev_port_obj_del_deferred);
 288}
 289
 290/**
 291 *      switchdev_port_obj_del - Delete port object
 292 *
 293 *      @dev: port device
 294 *      @obj: object to delete
 295 *
 296 *      rtnl_lock must be held and must not be in atomic section,
 297 *      in case SWITCHDEV_F_DEFER flag is not set.
 298 */
 299int switchdev_port_obj_del(struct net_device *dev,
 300                           const struct switchdev_obj *obj)
 301{
 302        if (obj->flags & SWITCHDEV_F_DEFER)
 303                return switchdev_port_obj_del_defer(dev, obj);
 304        ASSERT_RTNL();
 305        return switchdev_port_obj_del_now(dev, obj);
 306}
 307EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
 308
 309static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
 310static BLOCKING_NOTIFIER_HEAD(switchdev_blocking_notif_chain);
 311
 312/**
 313 *      register_switchdev_notifier - Register notifier
 314 *      @nb: notifier_block
 315 *
 316 *      Register switch device notifier.
 317 */
 318int register_switchdev_notifier(struct notifier_block *nb)
 319{
 320        return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
 321}
 322EXPORT_SYMBOL_GPL(register_switchdev_notifier);
 323
 324/**
 325 *      unregister_switchdev_notifier - Unregister notifier
 326 *      @nb: notifier_block
 327 *
 328 *      Unregister switch device notifier.
 329 */
 330int unregister_switchdev_notifier(struct notifier_block *nb)
 331{
 332        return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
 333}
 334EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
 335
 336/**
 337 *      call_switchdev_notifiers - Call notifiers
 338 *      @val: value passed unmodified to notifier function
 339 *      @dev: port device
 340 *      @info: notifier information data
 341 *      @extack: netlink extended ack
 342 *      Call all network notifier blocks.
 343 */
 344int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
 345                             struct switchdev_notifier_info *info,
 346                             struct netlink_ext_ack *extack)
 347{
 348        info->dev = dev;
 349        info->extack = extack;
 350        return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
 351}
 352EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
 353
 354int register_switchdev_blocking_notifier(struct notifier_block *nb)
 355{
 356        struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
 357
 358        return blocking_notifier_chain_register(chain, nb);
 359}
 360EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);
 361
 362int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
 363{
 364        struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;
 365
 366        return blocking_notifier_chain_unregister(chain, nb);
 367}
 368EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);
 369
 370int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
 371                                      struct switchdev_notifier_info *info,
 372                                      struct netlink_ext_ack *extack)
 373{
 374        info->dev = dev;
 375        info->extack = extack;
 376        return blocking_notifier_call_chain(&switchdev_blocking_notif_chain,
 377                                            val, info);
 378}
 379EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
 380
 381static int __switchdev_handle_port_obj_add(struct net_device *dev,
 382                        struct switchdev_notifier_port_obj_info *port_obj_info,
 383                        bool (*check_cb)(const struct net_device *dev),
 384                        int (*add_cb)(struct net_device *dev, const void *ctx,
 385                                      const struct switchdev_obj *obj,
 386                                      struct netlink_ext_ack *extack))
 387{
 388        struct switchdev_notifier_info *info = &port_obj_info->info;
 389        struct netlink_ext_ack *extack;
 390        struct net_device *lower_dev;
 391        struct list_head *iter;
 392        int err = -EOPNOTSUPP;
 393
 394        extack = switchdev_notifier_info_to_extack(info);
 395
 396        if (check_cb(dev)) {
 397                err = add_cb(dev, info->ctx, port_obj_info->obj, extack);
 398                if (err != -EOPNOTSUPP)
 399                        port_obj_info->handled = true;
 400                return err;
 401        }
 402
 403        /* Switch ports might be stacked under e.g. a LAG. Ignore the
 404         * unsupported devices, another driver might be able to handle them. But
 405         * propagate to the callers any hard errors.
 406         *
 407         * If the driver does its own bookkeeping of stacked ports, it's not
 408         * necessary to go through this helper.
 409         */
 410        netdev_for_each_lower_dev(dev, lower_dev, iter) {
 411                if (netif_is_bridge_master(lower_dev))
 412                        continue;
 413
 414                err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
 415                                                      check_cb, add_cb);
 416                if (err && err != -EOPNOTSUPP)
 417                        return err;
 418        }
 419
 420        return err;
 421}
 422
 423int switchdev_handle_port_obj_add(struct net_device *dev,
 424                        struct switchdev_notifier_port_obj_info *port_obj_info,
 425                        bool (*check_cb)(const struct net_device *dev),
 426                        int (*add_cb)(struct net_device *dev, const void *ctx,
 427                                      const struct switchdev_obj *obj,
 428                                      struct netlink_ext_ack *extack))
 429{
 430        int err;
 431
 432        err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
 433                                              add_cb);
 434        if (err == -EOPNOTSUPP)
 435                err = 0;
 436        return err;
 437}
 438EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);
 439
 440static int __switchdev_handle_port_obj_del(struct net_device *dev,
 441                        struct switchdev_notifier_port_obj_info *port_obj_info,
 442                        bool (*check_cb)(const struct net_device *dev),
 443                        int (*del_cb)(struct net_device *dev, const void *ctx,
 444                                      const struct switchdev_obj *obj))
 445{
 446        struct switchdev_notifier_info *info = &port_obj_info->info;
 447        struct net_device *lower_dev;
 448        struct list_head *iter;
 449        int err = -EOPNOTSUPP;
 450
 451        if (check_cb(dev)) {
 452                err = del_cb(dev, info->ctx, port_obj_info->obj);
 453                if (err != -EOPNOTSUPP)
 454                        port_obj_info->handled = true;
 455                return err;
 456        }
 457
 458        /* Switch ports might be stacked under e.g. a LAG. Ignore the
 459         * unsupported devices, another driver might be able to handle them. But
 460         * propagate to the callers any hard errors.
 461         *
 462         * If the driver does its own bookkeeping of stacked ports, it's not
 463         * necessary to go through this helper.
 464         */
 465        netdev_for_each_lower_dev(dev, lower_dev, iter) {
 466                if (netif_is_bridge_master(lower_dev))
 467                        continue;
 468
 469                err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
 470                                                      check_cb, del_cb);
 471                if (err && err != -EOPNOTSUPP)
 472                        return err;
 473        }
 474
 475        return err;
 476}
 477
 478int switchdev_handle_port_obj_del(struct net_device *dev,
 479                        struct switchdev_notifier_port_obj_info *port_obj_info,
 480                        bool (*check_cb)(const struct net_device *dev),
 481                        int (*del_cb)(struct net_device *dev, const void *ctx,
 482                                      const struct switchdev_obj *obj))
 483{
 484        int err;
 485
 486        err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
 487                                              del_cb);
 488        if (err == -EOPNOTSUPP)
 489                err = 0;
 490        return err;
 491}
 492EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
 493
 494static int __switchdev_handle_port_attr_set(struct net_device *dev,
 495                        struct switchdev_notifier_port_attr_info *port_attr_info,
 496                        bool (*check_cb)(const struct net_device *dev),
 497                        int (*set_cb)(struct net_device *dev, const void *ctx,
 498                                      const struct switchdev_attr *attr,
 499                                      struct netlink_ext_ack *extack))
 500{
 501        struct switchdev_notifier_info *info = &port_attr_info->info;
 502        struct netlink_ext_ack *extack;
 503        struct net_device *lower_dev;
 504        struct list_head *iter;
 505        int err = -EOPNOTSUPP;
 506
 507        extack = switchdev_notifier_info_to_extack(info);
 508
 509        if (check_cb(dev)) {
 510                err = set_cb(dev, info->ctx, port_attr_info->attr, extack);
 511                if (err != -EOPNOTSUPP)
 512                        port_attr_info->handled = true;
 513                return err;
 514        }
 515
 516        /* Switch ports might be stacked under e.g. a LAG. Ignore the
 517         * unsupported devices, another driver might be able to handle them. But
 518         * propagate to the callers any hard errors.
 519         *
 520         * If the driver does its own bookkeeping of stacked ports, it's not
 521         * necessary to go through this helper.
 522         */
 523        netdev_for_each_lower_dev(dev, lower_dev, iter) {
 524                if (netif_is_bridge_master(lower_dev))
 525                        continue;
 526
 527                err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
 528                                                       check_cb, set_cb);
 529                if (err && err != -EOPNOTSUPP)
 530                        return err;
 531        }
 532
 533        return err;
 534}
 535
 536int switchdev_handle_port_attr_set(struct net_device *dev,
 537                        struct switchdev_notifier_port_attr_info *port_attr_info,
 538                        bool (*check_cb)(const struct net_device *dev),
 539                        int (*set_cb)(struct net_device *dev, const void *ctx,
 540                                      const struct switchdev_attr *attr,
 541                                      struct netlink_ext_ack *extack))
 542{
 543        int err;
 544
 545        err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
 546                                               set_cb);
 547        if (err == -EOPNOTSUPP)
 548                err = 0;
 549        return err;
 550}
 551EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);
 552