net/hsr/hsr_device.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright 2011-2014 Autronica Fire and Security AS
   3  *
   4  * Author(s):
   5  *      2011-2014 Arvid Brodin, arvid.brodin@alten.se
   6  * This file contains device methods for creating, using and destroying
   7  * virtual HSR or PRP devices.
   8  */
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/etherdevice.h>
  13 #include <linux/rtnetlink.h>
  14 #include <linux/pkt_sched.h>
  15 #include "hsr_device.h"
  16 #include "hsr_slave.h"
  17 #include "hsr_framereg.h"
  18 #include "hsr_main.h"
  19 #include "hsr_forward.h"
  20
  21 static bool is_admin_up(struct net_device *dev)
  22 {
  23         return dev && (dev->flags & IFF_UP);
  24 }
  25
  26 static bool is_slave_up(struct net_device *dev)
  27 {
  28         return dev && is_admin_up(dev) && netif_oper_up(dev);
  29 }
  30
  31 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
  32 {
  33         struct net_device *dev = master->dev;
  34
  35         if (!is_admin_up(dev)) {
  36                 netif_set_operstate(dev, IF_OPER_DOWN);
  37                 return;
  38         }
  39
  40         if (has_carrier)
  41                 netif_set_operstate(dev, IF_OPER_UP);
  42         else
  43                 netif_set_operstate(dev, IF_OPER_LOWERLAYERDOWN);
  44 }
  45
  46 static bool hsr_check_carrier(struct hsr_port *master)
  47 {
  48         struct hsr_port *port;
  49
  50         ASSERT_RTNL();
  51
  52         hsr_for_each_port(master->hsr, port) {
  53                 if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
  54                         netif_carrier_on(master->dev);
  55                         return true;
  56                 }
  57         }
  58
  59         netif_carrier_off(master->dev);
  60
  61         return false;
  62 }
  63
  64 static void hsr_check_announce(struct net_device *hsr_dev)
  65 {
  66         struct hsr_priv *hsr;
  67
  68         hsr = netdev_priv(hsr_dev);
  69         if (netif_running(hsr_dev) && netif_oper_up(hsr_dev)) {
  70                 /* Enable announce timer and start sending supervisory frames */
  71                 if (!timer_pending(&hsr->announce_timer)) {
  72                         hsr->announce_count = 0;
  73                         mod_timer(&hsr->announce_timer, jiffies +
  74                                   msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
  75                 }
  76
  77                 if (hsr->redbox && !timer_pending(&hsr->announce_proxy_timer))
  78                         mod_timer(&hsr->announce_proxy_timer, jiffies +
  79                                   msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL) / 2);
  80         } else {
  81                 /* Deactivate the announce timer  */
  82                 timer_delete(&hsr->announce_timer);
  83                 if (hsr->redbox)
  84                         timer_delete(&hsr->announce_proxy_timer);
  85         }
  86 }
  87
  88 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
  89 {
  90         struct hsr_port *master;
  91         bool has_carrier;
  92
  93         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
  94         /* netif_stacked_transfer_operstate() cannot be used here since
  95          * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
  96          */
  97         has_carrier = hsr_check_carrier(master);
  98         hsr_set_operstate(master, has_carrier);
  99         hsr_check_announce(master->dev);
 100 }
 101
 102 int hsr_get_max_mtu(struct hsr_priv *hsr)
 103 {
 104         unsigned int mtu_max;
 105         struct hsr_port *port;
 106
 107         mtu_max = ETH_DATA_LEN;
 108         hsr_for_each_port(hsr, port)
 109                 if (port->type != HSR_PT_MASTER)
 110                         mtu_max = min(port->dev->mtu, mtu_max);
 111
 112         if (mtu_max < HSR_HLEN)
 113                 return 0;
 114         return mtu_max - HSR_HLEN;
 115 }
 116
 117 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
 118 {
 119         struct hsr_priv *hsr;
 120
 121         hsr = netdev_priv(dev);
 122
 123         if (new_mtu > hsr_get_max_mtu(hsr)) {
 124                 netdev_info(dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
 125                             HSR_HLEN);
 126                 return -EINVAL;
 127         }
 128
 129         WRITE_ONCE(dev->mtu, new_mtu);
 130
 131         return 0;
 132 }
 133
 134 static int hsr_dev_open(struct net_device *dev)
 135 {
 136         struct hsr_priv *hsr;
 137         struct hsr_port *port;
 138         const char *designation = NULL;
 139
 140         hsr = netdev_priv(dev);
 141
 142         hsr_for_each_port(hsr, port) {
 143                 if (port->type == HSR_PT_MASTER)
 144                         continue;
 145                 switch (port->type) {
 146                 case HSR_PT_SLAVE_A:
 147                         designation = "Slave A";
 148                         break;
 149                 case HSR_PT_SLAVE_B:
 150                         designation = "Slave B";
 151                         break;
 152                 case HSR_PT_INTERLINK:
 153                         designation = "Interlink";
 154                         break;
 155                 default:
 156                         designation = "Unknown";
 157                 }
 158                 if (!is_slave_up(port->dev))
 159                         netdev_warn(dev, "%s (%s) is not up; please bring it up to get a fully working HSR network\n",
 160                                     designation, port->dev->name);
 161         }
 162
 163         if (!designation)
 164                 netdev_warn(dev, "No slave devices configured\n");
 165
 166         return 0;
 167 }
 168
 169 static int hsr_dev_close(struct net_device *dev)
 170 {
 171         struct hsr_port *port;
 172         struct hsr_priv *hsr;
 173
 174         hsr = netdev_priv(dev);
 175         hsr_for_each_port(hsr, port) {
 176                 if (port->type == HSR_PT_MASTER)
 177                         continue;
 178                 switch (port->type) {
 179                 case HSR_PT_SLAVE_A:
 180                 case HSR_PT_SLAVE_B:
 181                         dev_uc_unsync(port->dev, dev);
 182                         dev_mc_unsync(port->dev, dev);
 183                         break;
 184                 default:
 185                         break;
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191
 192 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
 193                                                 netdev_features_t features)
 194 {
 195         netdev_features_t mask;
 196         struct hsr_port *port;
 197
 198         mask = features;
 199
 200         /* Mask out all features that, if supported by one device, should be
 201          * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
 202          *
 203          * Anything that's off in mask will not be enabled - so only things
 204          * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
 205          * may become enabled.
 206          */
 207         features &= ~NETIF_F_ONE_FOR_ALL;
 208         hsr_for_each_port(hsr, port)
 209                 features = netdev_increment_features(features,
 210                                                      port->dev->features,
 211                                                      mask);
 212
 213         return features;
 214 }
 215
 216 static netdev_features_t hsr_fix_features(struct net_device *dev,
 217                                           netdev_features_t features)
 218 {
 219         struct hsr_priv *hsr = netdev_priv(dev);
 220
 221         return hsr_features_recompute(hsr, features);
 222 }
 223
 224 static netdev_tx_t hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 225 {
 226         struct hsr_priv *hsr = netdev_priv(dev);
 227         struct hsr_port *master;
 228
 229         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 230         if (master) {
 231                 skb->dev = master->dev;
 232                 skb_reset_mac_header(skb);
 233                 skb_reset_mac_len(skb);
 234                 spin_lock_bh(&hsr->seqnr_lock);
 235                 hsr_forward_skb(skb, master);
 236                 spin_unlock_bh(&hsr->seqnr_lock);
 237         } else {
 238                 dev_core_stats_tx_dropped_inc(dev);
 239                 dev_kfree_skb_any(skb);
 240         }
 241         return NETDEV_TX_OK;
 242 }
 243
 244 static const struct header_ops hsr_header_ops = {
 245         .create  = eth_header,
 246         .parse   = eth_header_parse,
 247 };
 248
 249 static struct sk_buff *hsr_init_skb(struct hsr_port *master, int extra)
 250 {
 251         struct hsr_priv *hsr = master->hsr;
 252         struct sk_buff *skb;
 253         int hlen, tlen;
 254         int len;
 255
 256         hlen = LL_RESERVED_SPACE(master->dev);
 257         tlen = master->dev->needed_tailroom;
 258         len = sizeof(struct hsr_sup_tag) + sizeof(struct hsr_sup_payload);
 259         /* skb size is same for PRP/HSR frames, only difference
 260          * being, for PRP it is a trailer and for HSR it is a
 261          * header.
 262          * RedBox might use @extra more bytes.
 263          */
 264         skb = dev_alloc_skb(len + extra + hlen + tlen);
 265
 266         if (!skb)
 267                 return skb;
 268
 269         skb_reserve(skb, hlen);
 270         skb->dev = master->dev;
 271         skb->priority = TC_PRIO_CONTROL;
 272
 273         skb_reset_network_header(skb);
 274         skb_reset_transport_header(skb);
 275         if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
 276                             hsr->sup_multicast_addr,
 277                             skb->dev->dev_addr, skb->len) <= 0)
 278                 goto out;
 279
 280         skb_reset_mac_header(skb);
 281         skb_reset_mac_len(skb);
 282
 283         return skb;
 284 out:
 285         kfree_skb(skb);
 286
 287         return NULL;
 288 }
 289
 290 static void send_hsr_supervision_frame(struct hsr_port *port,
 291                                        unsigned long *interval,
 292                                        const unsigned char *addr)
 293 {
 294         struct hsr_priv *hsr = port->hsr;
 295         __u8 type = HSR_TLV_LIFE_CHECK;
 296         struct hsr_sup_payload *hsr_sp;
 297         struct hsr_sup_tlv *hsr_stlv;
 298         struct hsr_sup_tag *hsr_stag;
 299         struct sk_buff *skb;
 300         int extra = 0;
 301
 302         *interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 303         if (hsr->announce_count < 3 && hsr->prot_version == 0) {
 304                 type = HSR_TLV_ANNOUNCE;
 305                 *interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 306                 hsr->announce_count++;
 307         }
 308
 309         if (hsr->redbox)
 310                 extra = sizeof(struct hsr_sup_tlv) +
 311                         sizeof(struct hsr_sup_payload);
 312
 313         skb = hsr_init_skb(port, extra);
 314         if (!skb) {
 315                 netdev_warn_once(port->dev, "HSR: Could not send supervision frame\n");
 316                 return;
 317         }
 318
 319         hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
 320         set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
 321         set_hsr_stag_HSR_ver(hsr_stag, hsr->prot_version);
 322
 323         /* From HSRv1 on we have separate supervision sequence numbers. */
 324         spin_lock_bh(&hsr->seqnr_lock);
 325         if (hsr->prot_version > 0) {
 326                 hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
 327                 hsr->sup_sequence_nr++;
 328         } else {
 329                 hsr_stag->sequence_nr = htons(hsr->sequence_nr);
 330                 hsr->sequence_nr++;
 331         }
 332
 333         hsr_stag->tlv.HSR_TLV_type = type;
 334         /* TODO: Why 12 in HSRv0? */
 335         hsr_stag->tlv.HSR_TLV_length = hsr->prot_version ?
 336                                 sizeof(struct hsr_sup_payload) : 12;
 337
 338         /* Payload: MacAddressA / SAN MAC from ProxyNodeTable */
 339         hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 340         ether_addr_copy(hsr_sp->macaddress_A, addr);
 341
 342         if (hsr->redbox &&
 343             hsr_is_node_in_db(&hsr->proxy_node_db, addr)) {
 344                 hsr_stlv = skb_put(skb, sizeof(struct hsr_sup_tlv));
 345                 hsr_stlv->HSR_TLV_type = PRP_TLV_REDBOX_MAC;
 346                 hsr_stlv->HSR_TLV_length = sizeof(struct hsr_sup_payload);
 347
 348                 /* Payload: MacAddressRedBox */
 349                 hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 350                 ether_addr_copy(hsr_sp->macaddress_A, hsr->macaddress_redbox);
 351         }
 352
 353         if (skb_put_padto(skb, ETH_ZLEN)) {
 354                 spin_unlock_bh(&hsr->seqnr_lock);
 355                 return;
 356         }
 357
 358         hsr_forward_skb(skb, port);
 359         spin_unlock_bh(&hsr->seqnr_lock);
 360         return;
 361 }
 362
 363 static void send_prp_supervision_frame(struct hsr_port *master,
 364                                        unsigned long *interval,
 365                                        const unsigned char *addr)
 366 {
 367         struct hsr_priv *hsr = master->hsr;
 368         struct hsr_sup_payload *hsr_sp;
 369         struct hsr_sup_tag *hsr_stag;
 370         struct sk_buff *skb;
 371
 372         skb = hsr_init_skb(master, 0);
 373         if (!skb) {
 374                 netdev_warn_once(master->dev, "PRP: Could not send supervision frame\n");
 375                 return;
 376         }
 377
 378         *interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 379         hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
 380         set_hsr_stag_path(hsr_stag, (hsr->prot_version ? 0x0 : 0xf));
 381         set_hsr_stag_HSR_ver(hsr_stag, (hsr->prot_version ? 1 : 0));
 382
 383         /* From HSRv1 on we have separate supervision sequence numbers. */
 384         spin_lock_bh(&hsr->seqnr_lock);
 385         hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr);
 386         hsr->sup_sequence_nr++;
 387         hsr_stag->tlv.HSR_TLV_type = PRP_TLV_LIFE_CHECK_DD;
 388         hsr_stag->tlv.HSR_TLV_length = sizeof(struct hsr_sup_payload);
 389
 390         /* Payload: MacAddressA */
 391         hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 392         ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
 393
 394         if (skb_put_padto(skb, ETH_ZLEN)) {
 395                 spin_unlock_bh(&hsr->seqnr_lock);
 396                 return;
 397         }
 398
 399         hsr_forward_skb(skb, master);
 400         spin_unlock_bh(&hsr->seqnr_lock);
 401 }
 402
 403 /* Announce (supervision frame) timer function
 404  */
 405 static void hsr_announce(struct timer_list *t)
 406 {
 407         struct hsr_priv *hsr;
 408         struct hsr_port *master;
 409         unsigned long interval;
 410
 411         hsr = timer_container_of(hsr, t, announce_timer);
 412
 413         rcu_read_lock();
 414         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 415         hsr->proto_ops->send_sv_frame(master, &interval, master->dev->dev_addr);
 416
 417         if (is_admin_up(master->dev))
 418                 mod_timer(&hsr->announce_timer, jiffies + interval);
 419
 420         rcu_read_unlock();
 421 }
 422
 423 /* Announce (supervision frame) timer function for RedBox
 424  */
 425 static void hsr_proxy_announce(struct timer_list *t)
 426 {
 427         struct hsr_priv *hsr = timer_container_of(hsr, t,
 428                                                   announce_proxy_timer);
 429         struct hsr_port *interlink;
 430         unsigned long interval = 0;
 431         struct hsr_node *node;
 432
 433         rcu_read_lock();
 434         /* RedBOX sends supervisory frames to HSR network with MAC addresses
 435          * of SAN nodes stored in ProxyNodeTable.
 436          */
 437         interlink = hsr_port_get_hsr(hsr, HSR_PT_INTERLINK);
 438         if (!interlink)
 439                 goto done;
 440
 441         list_for_each_entry_rcu(node, &hsr->proxy_node_db, mac_list) {
 442                 if (hsr_addr_is_redbox(hsr, node->macaddress_A))
 443                         continue;
 444                 hsr->proto_ops->send_sv_frame(interlink, &interval,
 445                                               node->macaddress_A);
 446         }
 447
 448         if (is_admin_up(interlink->dev)) {
 449                 if (!interval)
 450                         interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 451
 452                 mod_timer(&hsr->announce_proxy_timer, jiffies + interval);
 453         }
 454
 455 done:
 456         rcu_read_unlock();
 457 }
 458
 459 void hsr_del_ports(struct hsr_priv *hsr)
 460 {
 461         struct hsr_port *port;
 462
 463         port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
 464         if (port)
 465                 hsr_del_port(port);
 466
 467         port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
 468         if (port)
 469                 hsr_del_port(port);
 470
 471         port = hsr_port_get_hsr(hsr, HSR_PT_INTERLINK);
 472         if (port)
 473                 hsr_del_port(port);
 474
 475         port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 476         if (port)
 477                 hsr_del_port(port);
 478 }
 479
 480 static void hsr_set_rx_mode(struct net_device *dev)
 481 {
 482         struct hsr_port *port;
 483         struct hsr_priv *hsr;
 484
 485         hsr = netdev_priv(dev);
 486
 487         hsr_for_each_port(hsr, port) {
 488                 if (port->type == HSR_PT_MASTER)
 489                         continue;
 490                 switch (port->type) {
 491                 case HSR_PT_SLAVE_A:
 492                 case HSR_PT_SLAVE_B:
 493                         dev_mc_sync_multiple(port->dev, dev);
 494                         dev_uc_sync_multiple(port->dev, dev);
 495                         break;
 496                 default:
 497                         break;
 498                 }
 499         }
 500 }
 501
 502 static void hsr_change_rx_flags(struct net_device *dev, int change)
 503 {
 504         struct hsr_port *port;
 505         struct hsr_priv *hsr;
 506
 507         hsr = netdev_priv(dev);
 508
 509         hsr_for_each_port(hsr, port) {
 510                 if (port->type == HSR_PT_MASTER)
 511                         continue;
 512                 switch (port->type) {
 513                 case HSR_PT_SLAVE_A:
 514                 case HSR_PT_SLAVE_B:
 515                         if (change & IFF_ALLMULTI)
 516                                 dev_set_allmulti(port->dev,
 517                                                  dev->flags &
 518                                                  IFF_ALLMULTI ? 1 : -1);
 519                         break;
 520                 default:
 521                         break;
 522                 }
 523         }
 524 }
 525
 526 static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev,
 527                                    __be16 proto, u16 vid)
 528 {
 529         bool is_slave_a_added = false;
 530         bool is_slave_b_added = false;
 531         struct hsr_port *port;
 532         struct hsr_priv *hsr;
 533         int ret = 0;
 534
 535         hsr = netdev_priv(dev);
 536
 537         hsr_for_each_port(hsr, port) {
 538                 if (port->type == HSR_PT_MASTER ||
 539                     port->type == HSR_PT_INTERLINK)
 540                         continue;
 541
 542                 ret = vlan_vid_add(port->dev, proto, vid);
 543                 switch (port->type) {
 544                 case HSR_PT_SLAVE_A:
 545                         if (ret) {
 546                                 /* clean up Slave-B */
 547                                 netdev_err(dev, "add vid failed for Slave-A\n");
 548                                 if (is_slave_b_added)
 549                                         vlan_vid_del(port->dev, proto, vid);
 550                                 return ret;
 551                         }
 552
 553                         is_slave_a_added = true;
 554                         break;
 555
 556                 case HSR_PT_SLAVE_B:
 557                         if (ret) {
 558                                 /* clean up Slave-A */
 559                                 netdev_err(dev, "add vid failed for Slave-B\n");
 560                                 if (is_slave_a_added)
 561                                         vlan_vid_del(port->dev, proto, vid);
 562                                 return ret;
 563                         }
 564
 565                         is_slave_b_added = true;
 566                         break;
 567                 default:
 568                         break;
 569                 }
 570         }
 571
 572         return 0;
 573 }
 574
 575 static int hsr_ndo_vlan_rx_kill_vid(struct net_device *dev,
 576                                     __be16 proto, u16 vid)
 577 {
 578         struct hsr_port *port;
 579         struct hsr_priv *hsr;
 580
 581         hsr = netdev_priv(dev);
 582
 583         hsr_for_each_port(hsr, port) {
 584                 switch (port->type) {
 585                 case HSR_PT_SLAVE_A:
 586                 case HSR_PT_SLAVE_B:
 587                         vlan_vid_del(port->dev, proto, vid);
 588                         break;
 589                 default:
 590                         break;
 591                 }
 592         }
 593
 594         return 0;
 595 }
 596
 597 static const struct net_device_ops hsr_device_ops = {
 598         .ndo_change_mtu = hsr_dev_change_mtu,
 599         .ndo_open = hsr_dev_open,
 600         .ndo_stop = hsr_dev_close,
 601         .ndo_start_xmit = hsr_dev_xmit,
 602         .ndo_change_rx_flags = hsr_change_rx_flags,
 603         .ndo_fix_features = hsr_fix_features,
 604         .ndo_set_rx_mode = hsr_set_rx_mode,
 605         .ndo_vlan_rx_add_vid = hsr_ndo_vlan_rx_add_vid,
 606         .ndo_vlan_rx_kill_vid = hsr_ndo_vlan_rx_kill_vid,
 607 };
 608
 609 static const struct device_type hsr_type = {
 610         .name = "hsr",
 611 };
 612
 613 static struct hsr_proto_ops hsr_ops = {
 614         .send_sv_frame = send_hsr_supervision_frame,
 615         .create_tagged_frame = hsr_create_tagged_frame,
 616         .get_untagged_frame = hsr_get_untagged_frame,
 617         .drop_frame = hsr_drop_frame,
 618         .fill_frame_info = hsr_fill_frame_info,
 619         .invalid_dan_ingress_frame = hsr_invalid_dan_ingress_frame,
 620         .register_frame_out = hsr_register_frame_out,
 621 };
 622
 623 static struct hsr_proto_ops prp_ops = {
 624         .send_sv_frame = send_prp_supervision_frame,
 625         .create_tagged_frame = prp_create_tagged_frame,
 626         .get_untagged_frame = prp_get_untagged_frame,
 627         .drop_frame = prp_drop_frame,
 628         .fill_frame_info = prp_fill_frame_info,
 629         .handle_san_frame = prp_handle_san_frame,
 630         .update_san_info = prp_update_san_info,
 631         .register_frame_out = prp_register_frame_out,
 632 };
 633
 634 void hsr_dev_setup(struct net_device *dev)
 635 {
 636         eth_hw_addr_random(dev);
 637
 638         ether_setup(dev);
 639         dev->min_mtu = 0;
 640         dev->header_ops = &hsr_header_ops;
 641         dev->netdev_ops = &hsr_device_ops;
 642         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 643         dev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
 644         /* Prevent recursive tx locking */
 645         dev->lltx = true;
 646         /* Not sure about this. Taken from bridge code. netdevice.h says
 647          * it means "Does not change network namespaces".
 648          */
 649         dev->netns_immutable = true;
 650
 651         dev->needs_free_netdev = true;
 652
 653         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 654                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 655                            NETIF_F_HW_VLAN_CTAG_TX |
 656                            NETIF_F_HW_VLAN_CTAG_FILTER;
 657
 658         dev->features = dev->hw_features;
 659 }
 660
 661 /* Return true if dev is a HSR master; return false otherwise.
 662  */
 663 bool is_hsr_master(struct net_device *dev)
 664 {
 665         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 666 }
 667 EXPORT_SYMBOL(is_hsr_master);
 668
 669 struct net_device *hsr_get_port_ndev(struct net_device *ndev,
 670                                      enum hsr_port_type pt)
 671 {
 672         struct hsr_priv *hsr = netdev_priv(ndev);
 673         struct hsr_port *port;
 674
 675         hsr_for_each_port(hsr, port)
 676                 if (port->type == pt)
 677                         return port->dev;
 678         return NULL;
 679 }
 680 EXPORT_SYMBOL(hsr_get_port_ndev);
 681
 682 /* Default multicast address for HSR Supervision frames */
 683 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 684         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 685 };
 686
 687 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 688                      struct net_device *interlink, unsigned char multicast_spec,
 689                      u8 protocol_version, struct netlink_ext_ack *extack)
 690 {
 691         bool unregister = false;
 692         struct hsr_priv *hsr;
 693         int res;
 694
 695         hsr = netdev_priv(hsr_dev);
 696         INIT_LIST_HEAD(&hsr->ports);
 697         INIT_LIST_HEAD(&hsr->node_db);
 698         INIT_LIST_HEAD(&hsr->proxy_node_db);
 699         spin_lock_init(&hsr->list_lock);
 700
 701         eth_hw_addr_set(hsr_dev, slave[0]->dev_addr);
 702
 703         /* initialize protocol specific functions */
 704         if (protocol_version == PRP_V1) {
 705                 /* For PRP, lan_id has most significant 3 bits holding
 706                  * the net_id of PRP_LAN_ID
 707                  */
 708                 hsr->net_id = PRP_LAN_ID << 1;
 709                 hsr->proto_ops = &prp_ops;
 710         } else {
 711                 hsr->proto_ops = &hsr_ops;
 712         }
 713
 714         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 715         res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
 716                                    slave[1]->dev_addr);
 717         if (res < 0)
 718                 return res;
 719
 720         spin_lock_init(&hsr->seqnr_lock);
 721         /* Overflow soon to find bugs easier: */
 722         hsr->sequence_nr = HSR_SEQNR_START;
 723         hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
 724
 725         timer_setup(&hsr->announce_timer, hsr_announce, 0);
 726         timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
 727         timer_setup(&hsr->prune_proxy_timer, hsr_prune_proxy_nodes, 0);
 728         timer_setup(&hsr->announce_proxy_timer, hsr_proxy_announce, 0);
 729
 730         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 731         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 732
 733         hsr->prot_version = protocol_version;
 734
 735         /* Make sure the 1st call to netif_carrier_on() gets through */
 736         netif_carrier_off(hsr_dev);
 737
 738         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER, extack);
 739         if (res)
 740                 goto err_add_master;
 741
 742         /* HSR forwarding offload supported in lower device? */
 743         if ((slave[0]->features & NETIF_F_HW_HSR_FWD) &&
 744             (slave[1]->features & NETIF_F_HW_HSR_FWD))
 745                 hsr->fwd_offloaded = true;
 746
 747         if ((slave[0]->features & NETIF_F_HW_VLAN_CTAG_FILTER) &&
 748             (slave[1]->features & NETIF_F_HW_VLAN_CTAG_FILTER))
 749                 hsr_dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
 750
 751         res = register_netdevice(hsr_dev);
 752         if (res)
 753                 goto err_unregister;
 754
 755         unregister = true;
 756
 757         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A, extack);
 758         if (res)
 759                 goto err_unregister;
 760
 761         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
 762         if (res)
 763                 goto err_unregister;
 764
 765         if (protocol_version == PRP_V1) {
 766                 eth_hw_addr_set(slave[1], slave[0]->dev_addr);
 767                 call_netdevice_notifiers(NETDEV_CHANGEADDR, slave[1]);
 768         }
 769
 770         if (interlink) {
 771                 res = hsr_add_port(hsr, interlink, HSR_PT_INTERLINK, extack);
 772                 if (res)
 773                         goto err_unregister;
 774
 775                 hsr->redbox = true;
 776                 ether_addr_copy(hsr->macaddress_redbox, interlink->dev_addr);
 777                 mod_timer(&hsr->prune_proxy_timer,
 778                           jiffies + msecs_to_jiffies(PRUNE_PROXY_PERIOD));
 779         }
 780
 781         hsr_debugfs_init(hsr, hsr_dev);
 782         mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
 783
 784         return 0;
 785
 786 err_unregister:
 787         hsr_del_ports(hsr);
 788 err_add_master:
 789         hsr_del_self_node(hsr);
 790
 791         if (unregister)
 792                 unregister_netdevice(hsr_dev);
 793         return res;
 794 }