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  *
   7  * This file contains device methods for creating, using and destroying
   8  * virtual HSR devices.
   9  */
  10
  11 #include <linux/netdevice.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/pkt_sched.h>
  16 #include "hsr_device.h"
  17 #include "hsr_slave.h"
  18 #include "hsr_framereg.h"
  19 #include "hsr_main.h"
  20 #include "hsr_forward.h"
  21
  22 static bool is_admin_up(struct net_device *dev)
  23 {
  24         return dev && (dev->flags & IFF_UP);
  25 }
  26
  27 static bool is_slave_up(struct net_device *dev)
  28 {
  29         return dev && is_admin_up(dev) && netif_oper_up(dev);
  30 }
  31
  32 static void __hsr_set_operstate(struct net_device *dev, int transition)
  33 {
  34         write_lock_bh(&dev_base_lock);
  35         if (dev->operstate != transition) {
  36                 dev->operstate = transition;
  37                 write_unlock_bh(&dev_base_lock);
  38                 netdev_state_change(dev);
  39         } else {
  40                 write_unlock_bh(&dev_base_lock);
  41         }
  42 }
  43
  44 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
  45 {
  46         if (!is_admin_up(master->dev)) {
  47                 __hsr_set_operstate(master->dev, IF_OPER_DOWN);
  48                 return;
  49         }
  50
  51         if (has_carrier)
  52                 __hsr_set_operstate(master->dev, IF_OPER_UP);
  53         else
  54                 __hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
  55 }
  56
  57 static bool hsr_check_carrier(struct hsr_port *master)
  58 {
  59         struct hsr_port *port;
  60         bool has_carrier;
  61
  62         has_carrier = false;
  63
  64         rcu_read_lock();
  65         hsr_for_each_port(master->hsr, port)
  66                 if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
  67                         has_carrier = true;
  68                         break;
  69                 }
  70         rcu_read_unlock();
  71
  72         if (has_carrier)
  73                 netif_carrier_on(master->dev);
  74         else
  75                 netif_carrier_off(master->dev);
  76
  77         return has_carrier;
  78 }
  79
  80 static void hsr_check_announce(struct net_device *hsr_dev,
  81                                unsigned char old_operstate)
  82 {
  83         struct hsr_priv *hsr;
  84
  85         hsr = netdev_priv(hsr_dev);
  86
  87         if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) {
  88                 /* Went up */
  89                 hsr->announce_count = 0;
  90                 mod_timer(&hsr->announce_timer,
  91                           jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
  92         }
  93
  94         if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP)
  95                 /* Went down */
  96                 del_timer(&hsr->announce_timer);
  97 }
  98
  99 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
 100 {
 101         struct hsr_port *master;
 102         unsigned char old_operstate;
 103         bool has_carrier;
 104
 105         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 106         /* netif_stacked_transfer_operstate() cannot be used here since
 107          * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
 108          */
 109         old_operstate = master->dev->operstate;
 110         has_carrier = hsr_check_carrier(master);
 111         hsr_set_operstate(master, has_carrier);
 112         hsr_check_announce(master->dev, old_operstate);
 113 }
 114
 115 int hsr_get_max_mtu(struct hsr_priv *hsr)
 116 {
 117         unsigned int mtu_max;
 118         struct hsr_port *port;
 119
 120         mtu_max = ETH_DATA_LEN;
 121         rcu_read_lock();
 122         hsr_for_each_port(hsr, port)
 123                 if (port->type != HSR_PT_MASTER)
 124                         mtu_max = min(port->dev->mtu, mtu_max);
 125         rcu_read_unlock();
 126
 127         if (mtu_max < HSR_HLEN)
 128                 return 0;
 129         return mtu_max - HSR_HLEN;
 130 }
 131
 132 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
 133 {
 134         struct hsr_priv *hsr;
 135         struct hsr_port *master;
 136
 137         hsr = netdev_priv(dev);
 138         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 139
 140         if (new_mtu > hsr_get_max_mtu(hsr)) {
 141                 netdev_info(master->dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
 142                             HSR_HLEN);
 143                 return -EINVAL;
 144         }
 145
 146         dev->mtu = new_mtu;
 147
 148         return 0;
 149 }
 150
 151 static int hsr_dev_open(struct net_device *dev)
 152 {
 153         struct hsr_priv *hsr;
 154         struct hsr_port *port;
 155         char designation;
 156
 157         hsr = netdev_priv(dev);
 158         designation = '\0';
 159
 160         rcu_read_lock();
 161         hsr_for_each_port(hsr, port) {
 162                 if (port->type == HSR_PT_MASTER)
 163                         continue;
 164                 switch (port->type) {
 165                 case HSR_PT_SLAVE_A:
 166                         designation = 'A';
 167                         break;
 168                 case HSR_PT_SLAVE_B:
 169                         designation = 'B';
 170                         break;
 171                 default:
 172                         designation = '?';
 173                 }
 174                 if (!is_slave_up(port->dev))
 175                         netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
 176                                     designation, port->dev->name);
 177         }
 178         rcu_read_unlock();
 179
 180         if (designation == '\0')
 181                 netdev_warn(dev, "No slave devices configured\n");
 182
 183         return 0;
 184 }
 185
 186 static int hsr_dev_close(struct net_device *dev)
 187 {
 188         /* Nothing to do here. */
 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 int 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                 hsr_forward_skb(skb, master);
 233         } else {
 234                 atomic_long_inc(&dev->tx_dropped);
 235                 dev_kfree_skb_any(skb);
 236         }
 237         return NETDEV_TX_OK;
 238 }
 239
 240 static const struct header_ops hsr_header_ops = {
 241         .create  = eth_header,
 242         .parse   = eth_header_parse,
 243 };
 244
 245 static void send_hsr_supervision_frame(struct hsr_port *master,
 246                                        u8 type, u8 hsr_ver)
 247 {
 248         struct sk_buff *skb;
 249         int hlen, tlen;
 250         struct hsr_tag *hsr_tag;
 251         struct hsr_sup_tag *hsr_stag;
 252         struct hsr_sup_payload *hsr_sp;
 253         unsigned long irqflags;
 254
 255         hlen = LL_RESERVED_SPACE(master->dev);
 256         tlen = master->dev->needed_tailroom;
 257         skb = dev_alloc_skb(sizeof(struct hsr_tag) +
 258                             sizeof(struct hsr_sup_tag) +
 259                             sizeof(struct hsr_sup_payload) + hlen + tlen);
 260
 261         if (!skb)
 262                 return;
 263
 264         skb_reserve(skb, hlen);
 265
 266         skb->dev = master->dev;
 267         skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
 268         skb->priority = TC_PRIO_CONTROL;
 269
 270         if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
 271                             master->hsr->sup_multicast_addr,
 272                             skb->dev->dev_addr, skb->len) <= 0)
 273                 goto out;
 274         skb_reset_mac_header(skb);
 275         skb_reset_network_header(skb);
 276         skb_reset_transport_header(skb);
 277
 278         if (hsr_ver > 0) {
 279                 hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
 280                 hsr_tag->encap_proto = htons(ETH_P_PRP);
 281                 set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
 282         }
 283
 284         hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
 285         set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
 286         set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
 287
 288         /* From HSRv1 on we have separate supervision sequence numbers. */
 289         spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
 290         if (hsr_ver > 0) {
 291                 hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
 292                 hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
 293                 master->hsr->sup_sequence_nr++;
 294                 master->hsr->sequence_nr++;
 295         } else {
 296                 hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
 297                 master->hsr->sequence_nr++;
 298         }
 299         spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 300
 301         hsr_stag->HSR_TLV_type = type;
 302         /* TODO: Why 12 in HSRv0? */
 303         hsr_stag->HSR_TLV_length =
 304                                 hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
 305
 306         /* Payload: MacAddressA */
 307         hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 308         ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
 309
 310         if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
 311                 return;
 312
 313         hsr_forward_skb(skb, master);
 314         return;
 315
 316 out:
 317         WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 318         kfree_skb(skb);
 319 }
 320
 321 /* Announce (supervision frame) timer function
 322  */
 323 static void hsr_announce(struct timer_list *t)
 324 {
 325         struct hsr_priv *hsr;
 326         struct hsr_port *master;
 327         unsigned long interval;
 328
 329         hsr = from_timer(hsr, t, announce_timer);
 330
 331         rcu_read_lock();
 332         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 333
 334         if (hsr->announce_count < 3 && hsr->prot_version == 0) {
 335                 send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
 336                                            hsr->prot_version);
 337                 hsr->announce_count++;
 338
 339                 interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 340         } else {
 341                 send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
 342                                            hsr->prot_version);
 343
 344                 interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 345         }
 346
 347         if (is_admin_up(master->dev))
 348                 mod_timer(&hsr->announce_timer, jiffies + interval);
 349
 350         rcu_read_unlock();
 351 }
 352
 353 /* This has to be called after all the readers are gone.
 354  * Otherwise we would have to check the return value of
 355  * hsr_port_get_hsr().
 356  */
 357 static void hsr_dev_destroy(struct net_device *hsr_dev)
 358 {
 359         struct hsr_priv *hsr;
 360         struct hsr_port *port;
 361         struct hsr_port *tmp;
 362
 363         hsr = netdev_priv(hsr_dev);
 364
 365         hsr_debugfs_term(hsr);
 366
 367         list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
 368                 hsr_del_port(port);
 369
 370         del_timer_sync(&hsr->prune_timer);
 371         del_timer_sync(&hsr->announce_timer);
 372
 373         hsr_del_self_node(hsr);
 374         hsr_del_nodes(&hsr->node_db);
 375 }
 376
 377 static const struct net_device_ops hsr_device_ops = {
 378         .ndo_change_mtu = hsr_dev_change_mtu,
 379         .ndo_open = hsr_dev_open,
 380         .ndo_stop = hsr_dev_close,
 381         .ndo_start_xmit = hsr_dev_xmit,
 382         .ndo_fix_features = hsr_fix_features,
 383         .ndo_uninit = hsr_dev_destroy,
 384 };
 385
 386 static struct device_type hsr_type = {
 387         .name = "hsr",
 388 };
 389
 390 void hsr_dev_setup(struct net_device *dev)
 391 {
 392         eth_hw_addr_random(dev);
 393
 394         ether_setup(dev);
 395         dev->min_mtu = 0;
 396         dev->header_ops = &hsr_header_ops;
 397         dev->netdev_ops = &hsr_device_ops;
 398         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 399         dev->priv_flags |= IFF_NO_QUEUE;
 400
 401         dev->needs_free_netdev = true;
 402
 403         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 404                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 405                            NETIF_F_HW_VLAN_CTAG_TX;
 406
 407         dev->features = dev->hw_features;
 408
 409         /* Prevent recursive tx locking */
 410         dev->features |= NETIF_F_LLTX;
 411         /* VLAN on top of HSR needs testing and probably some work on
 412          * hsr_header_create() etc.
 413          */
 414         dev->features |= NETIF_F_VLAN_CHALLENGED;
 415         /* Not sure about this. Taken from bridge code. netdev_features.h says
 416          * it means "Does not change network namespaces".
 417          */
 418         dev->features |= NETIF_F_NETNS_LOCAL;
 419 }
 420
 421 /* Return true if dev is a HSR master; return false otherwise.
 422  */
 423 inline bool is_hsr_master(struct net_device *dev)
 424 {
 425         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 426 }
 427
 428 /* Default multicast address for HSR Supervision frames */
 429 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 430         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 431 };
 432
 433 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 434                      unsigned char multicast_spec, u8 protocol_version)
 435 {
 436         struct hsr_priv *hsr;
 437         struct hsr_port *port;
 438         struct hsr_port *tmp;
 439         int res;
 440
 441         hsr = netdev_priv(hsr_dev);
 442         INIT_LIST_HEAD(&hsr->ports);
 443         INIT_LIST_HEAD(&hsr->node_db);
 444         INIT_LIST_HEAD(&hsr->self_node_db);
 445         spin_lock_init(&hsr->list_lock);
 446
 447         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 448
 449         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 450         res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
 451                                    slave[1]->dev_addr);
 452         if (res < 0)
 453                 return res;
 454
 455         spin_lock_init(&hsr->seqnr_lock);
 456         /* Overflow soon to find bugs easier: */
 457         hsr->sequence_nr = HSR_SEQNR_START;
 458         hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
 459
 460         timer_setup(&hsr->announce_timer, hsr_announce, 0);
 461         timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
 462
 463         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 464         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 465
 466         hsr->prot_version = protocol_version;
 467
 468         /* FIXME: should I modify the value of these?
 469          *
 470          * - hsr_dev->flags - i.e.
 471          *                      IFF_MASTER/SLAVE?
 472          * - hsr_dev->priv_flags - i.e.
 473          *                      IFF_EBRIDGE?
 474          *                      IFF_TX_SKB_SHARING?
 475          *                      IFF_HSR_MASTER/SLAVE?
 476          */
 477
 478         /* Make sure the 1st call to netif_carrier_on() gets through */
 479         netif_carrier_off(hsr_dev);
 480
 481         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 482         if (res)
 483                 goto err_add_master;
 484
 485         res = register_netdevice(hsr_dev);
 486         if (res)
 487                 goto err_unregister;
 488
 489         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 490         if (res)
 491                 goto err_add_slaves;
 492
 493         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 494         if (res)
 495                 goto err_add_slaves;
 496
 497         hsr_debugfs_init(hsr, hsr_dev);
 498         mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
 499
 500         return 0;
 501
 502 err_add_slaves:
 503         unregister_netdevice(hsr_dev);
 504 err_unregister:
 505         list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
 506                 hsr_del_port(port);
 507 err_add_master:
 508         hsr_del_self_node(hsr);
 509
 510         return res;
 511 }