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         skb->dev = master->dev;
 231         hsr_forward_skb(skb, master);
 232
 233         return NETDEV_TX_OK;
 234 }
 235
 236 static const struct header_ops hsr_header_ops = {
 237         .create  = eth_header,
 238         .parse   = eth_header_parse,
 239 };
 240
 241 static void send_hsr_supervision_frame(struct hsr_port *master,
 242                                        u8 type, u8 hsr_ver)
 243 {
 244         struct sk_buff *skb;
 245         int hlen, tlen;
 246         struct hsr_tag *hsr_tag;
 247         struct hsr_sup_tag *hsr_stag;
 248         struct hsr_sup_payload *hsr_sp;
 249         unsigned long irqflags;
 250
 251         hlen = LL_RESERVED_SPACE(master->dev);
 252         tlen = master->dev->needed_tailroom;
 253         skb = dev_alloc_skb(sizeof(struct hsr_tag) +
 254                             sizeof(struct hsr_sup_tag) +
 255                             sizeof(struct hsr_sup_payload) + hlen + tlen);
 256
 257         if (!skb)
 258                 return;
 259
 260         skb_reserve(skb, hlen);
 261
 262         skb->dev = master->dev;
 263         skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
 264         skb->priority = TC_PRIO_CONTROL;
 265
 266         if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
 267                             master->hsr->sup_multicast_addr,
 268                             skb->dev->dev_addr, skb->len) <= 0)
 269                 goto out;
 270         skb_reset_mac_header(skb);
 271
 272         if (hsr_ver > 0) {
 273                 hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
 274                 hsr_tag->encap_proto = htons(ETH_P_PRP);
 275                 set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
 276         }
 277
 278         hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
 279         set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
 280         set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
 281
 282         /* From HSRv1 on we have separate supervision sequence numbers. */
 283         spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
 284         if (hsr_ver > 0) {
 285                 hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
 286                 hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
 287                 master->hsr->sup_sequence_nr++;
 288                 master->hsr->sequence_nr++;
 289         } else {
 290                 hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
 291                 master->hsr->sequence_nr++;
 292         }
 293         spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 294
 295         hsr_stag->HSR_TLV_type = type;
 296         /* TODO: Why 12 in HSRv0? */
 297         hsr_stag->HSR_TLV_length =
 298                                 hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
 299
 300         /* Payload: MacAddressA */
 301         hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 302         ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
 303
 304         if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
 305                 return;
 306
 307         hsr_forward_skb(skb, master);
 308         return;
 309
 310 out:
 311         WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 312         kfree_skb(skb);
 313 }
 314
 315 /* Announce (supervision frame) timer function
 316  */
 317 static void hsr_announce(struct timer_list *t)
 318 {
 319         struct hsr_priv *hsr;
 320         struct hsr_port *master;
 321         unsigned long interval;
 322
 323         hsr = from_timer(hsr, t, announce_timer);
 324
 325         rcu_read_lock();
 326         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 327
 328         if (hsr->announce_count < 3 && hsr->prot_version == 0) {
 329                 send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
 330                                            hsr->prot_version);
 331                 hsr->announce_count++;
 332
 333                 interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 334         } else {
 335                 send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
 336                                            hsr->prot_version);
 337
 338                 interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 339         }
 340
 341         if (is_admin_up(master->dev))
 342                 mod_timer(&hsr->announce_timer, jiffies + interval);
 343
 344         rcu_read_unlock();
 345 }
 346
 347 /* According to comments in the declaration of struct net_device, this function
 348  * is "Called from unregister, can be used to call free_netdev". Ok then...
 349  */
 350 static void hsr_dev_destroy(struct net_device *hsr_dev)
 351 {
 352         struct hsr_priv *hsr;
 353         struct hsr_port *port;
 354
 355         hsr = netdev_priv(hsr_dev);
 356
 357         hsr_debugfs_term(hsr);
 358
 359         rtnl_lock();
 360         hsr_for_each_port(hsr, port)
 361                 hsr_del_port(port);
 362         rtnl_unlock();
 363
 364         del_timer_sync(&hsr->prune_timer);
 365         del_timer_sync(&hsr->announce_timer);
 366
 367         synchronize_rcu();
 368 }
 369
 370 static const struct net_device_ops hsr_device_ops = {
 371         .ndo_change_mtu = hsr_dev_change_mtu,
 372         .ndo_open = hsr_dev_open,
 373         .ndo_stop = hsr_dev_close,
 374         .ndo_start_xmit = hsr_dev_xmit,
 375         .ndo_fix_features = hsr_fix_features,
 376 };
 377
 378 static struct device_type hsr_type = {
 379         .name = "hsr",
 380 };
 381
 382 void hsr_dev_setup(struct net_device *dev)
 383 {
 384         eth_hw_addr_random(dev);
 385
 386         ether_setup(dev);
 387         dev->min_mtu = 0;
 388         dev->header_ops = &hsr_header_ops;
 389         dev->netdev_ops = &hsr_device_ops;
 390         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 391         dev->priv_flags |= IFF_NO_QUEUE;
 392
 393         dev->needs_free_netdev = true;
 394         dev->priv_destructor = hsr_dev_destroy;
 395
 396         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 397                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 398                            NETIF_F_HW_VLAN_CTAG_TX;
 399
 400         dev->features = dev->hw_features;
 401
 402         /* Prevent recursive tx locking */
 403         dev->features |= NETIF_F_LLTX;
 404         /* VLAN on top of HSR needs testing and probably some work on
 405          * hsr_header_create() etc.
 406          */
 407         dev->features |= NETIF_F_VLAN_CHALLENGED;
 408         /* Not sure about this. Taken from bridge code. netdev_features.h says
 409          * it means "Does not change network namespaces".
 410          */
 411         dev->features |= NETIF_F_NETNS_LOCAL;
 412 }
 413
 414 /* Return true if dev is a HSR master; return false otherwise.
 415  */
 416 inline bool is_hsr_master(struct net_device *dev)
 417 {
 418         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 419 }
 420
 421 /* Default multicast address for HSR Supervision frames */
 422 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 423         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 424 };
 425
 426 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 427                      unsigned char multicast_spec, u8 protocol_version)
 428 {
 429         struct hsr_priv *hsr;
 430         struct hsr_port *port;
 431         int res;
 432
 433         hsr = netdev_priv(hsr_dev);
 434         INIT_LIST_HEAD(&hsr->ports);
 435         INIT_LIST_HEAD(&hsr->node_db);
 436         INIT_LIST_HEAD(&hsr->self_node_db);
 437
 438         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 439
 440         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 441         res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 442                                    slave[1]->dev_addr);
 443         if (res < 0)
 444                 return res;
 445
 446         spin_lock_init(&hsr->seqnr_lock);
 447         /* Overflow soon to find bugs easier: */
 448         hsr->sequence_nr = HSR_SEQNR_START;
 449         hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
 450
 451         timer_setup(&hsr->announce_timer, hsr_announce, 0);
 452         timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
 453
 454         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 455         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 456
 457         hsr->prot_version = protocol_version;
 458
 459         /* FIXME: should I modify the value of these?
 460          *
 461          * - hsr_dev->flags - i.e.
 462          *                      IFF_MASTER/SLAVE?
 463          * - hsr_dev->priv_flags - i.e.
 464          *                      IFF_EBRIDGE?
 465          *                      IFF_TX_SKB_SHARING?
 466          *                      IFF_HSR_MASTER/SLAVE?
 467          */
 468
 469         /* Make sure the 1st call to netif_carrier_on() gets through */
 470         netif_carrier_off(hsr_dev);
 471
 472         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 473         if (res)
 474                 goto err_add_port;
 475
 476         res = register_netdevice(hsr_dev);
 477         if (res)
 478                 goto fail;
 479
 480         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 481         if (res)
 482                 goto fail;
 483         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 484         if (res)
 485                 goto fail;
 486
 487         mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
 488         res = hsr_debugfs_init(hsr, hsr_dev);
 489         if (res)
 490                 goto fail;
 491
 492         return 0;
 493
 494 fail:
 495         hsr_for_each_port(hsr, port)
 496                 hsr_del_port(port);
 497 err_add_port:
 498         hsr_del_node(&hsr->self_node_db);
 499
 500         return res;
 501 }