net/hsr/hsr_device.c

   1 /* Copyright 2011-2014 Autronica Fire and Security AS
   2  *
   3  * This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the GNU General Public License as published by the Free
   5  * Software Foundation; either version 2 of the License, or (at your option)
   6  * any later version.
   7  *
   8  * Author(s):
   9  *      2011-2014 Arvid Brodin, arvid.brodin@alten.se
  10  *
  11  * This file contains device methods for creating, using and destroying
  12  * virtual HSR devices.
  13  */
  14
  15 #include <linux/netdevice.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/pkt_sched.h>
  20 #include "hsr_device.h"
  21 #include "hsr_slave.h"
  22 #include "hsr_framereg.h"
  23 #include "hsr_main.h"
  24
  25
  26 static bool is_admin_up(struct net_device *dev)
  27 {
  28         return dev && (dev->flags & IFF_UP);
  29 }
  30
  31 static bool is_slave_up(struct net_device *dev)
  32 {
  33         return dev && is_admin_up(dev) && netif_oper_up(dev);
  34 }
  35
  36 static void __hsr_set_operstate(struct net_device *dev, int transition)
  37 {
  38         write_lock_bh(&dev_base_lock);
  39         if (dev->operstate != transition) {
  40                 dev->operstate = transition;
  41                 write_unlock_bh(&dev_base_lock);
  42                 netdev_state_change(dev);
  43         } else {
  44                 write_unlock_bh(&dev_base_lock);
  45         }
  46 }
  47
  48 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
  49 {
  50         if (!is_admin_up(master->dev)) {
  51                 __hsr_set_operstate(master->dev, IF_OPER_DOWN);
  52                 return;
  53         }
  54
  55         if (has_carrier)
  56                 __hsr_set_operstate(master->dev, IF_OPER_UP);
  57         else
  58                 __hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
  59 }
  60
  61 static bool hsr_check_carrier(struct hsr_port *master)
  62 {
  63         struct hsr_port *port;
  64         bool has_carrier;
  65
  66         has_carrier = false;
  67
  68         rcu_read_lock();
  69         hsr_for_each_port(master->hsr, port)
  70                 if ((port->type != HSR_PT_MASTER) && is_slave_up(port->dev)) {
  71                         has_carrier = true;
  72                         break;
  73                 }
  74         rcu_read_unlock();
  75
  76         if (has_carrier)
  77                 netif_carrier_on(master->dev);
  78         else
  79                 netif_carrier_off(master->dev);
  80
  81         return has_carrier;
  82 }
  83
  84
  85 static void hsr_check_announce(struct net_device *hsr_dev,
  86                                unsigned char old_operstate)
  87 {
  88         struct hsr_priv *hsr;
  89
  90         hsr = netdev_priv(hsr_dev);
  91
  92         if ((hsr_dev->operstate == IF_OPER_UP) && (old_operstate != IF_OPER_UP)) {
  93                 /* Went up */
  94                 hsr->announce_count = 0;
  95                 hsr->announce_timer.expires = jiffies +
  96                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
  97                 add_timer(&hsr->announce_timer);
  98         }
  99
 100         if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
 101                 /* Went down */
 102                 del_timer(&hsr->announce_timer);
 103 }
 104
 105 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
 106 {
 107         struct hsr_port *master;
 108         unsigned char old_operstate;
 109         bool has_carrier;
 110
 111         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 112         /* netif_stacked_transfer_operstate() cannot be used here since
 113          * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
 114          */
 115         old_operstate = master->dev->operstate;
 116         has_carrier = hsr_check_carrier(master);
 117         hsr_set_operstate(master, has_carrier);
 118         hsr_check_announce(master->dev, old_operstate);
 119 }
 120
 121 int hsr_get_max_mtu(struct hsr_priv *hsr)
 122 {
 123         unsigned int mtu_max;
 124         struct hsr_port *port;
 125
 126         mtu_max = ETH_DATA_LEN;
 127         rcu_read_lock();
 128         hsr_for_each_port(hsr, port)
 129                 if (port->type != HSR_PT_MASTER)
 130                         mtu_max = min(port->dev->mtu, mtu_max);
 131         rcu_read_unlock();
 132
 133         if (mtu_max < HSR_HLEN)
 134                 return 0;
 135         return mtu_max - HSR_HLEN;
 136 }
 137
 138
 139 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
 140 {
 141         struct hsr_priv *hsr;
 142         struct hsr_port *master;
 143
 144         hsr = netdev_priv(dev);
 145         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 146
 147         if (new_mtu > hsr_get_max_mtu(hsr)) {
 148                 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",
 149                             HSR_HLEN);
 150                 return -EINVAL;
 151         }
 152
 153         dev->mtu = new_mtu;
 154
 155         return 0;
 156 }
 157
 158 static int hsr_dev_open(struct net_device *dev)
 159 {
 160         struct hsr_priv *hsr;
 161         struct hsr_port *port;
 162         char designation;
 163
 164         hsr = netdev_priv(dev);
 165         designation = '\0';
 166
 167         rcu_read_lock();
 168         hsr_for_each_port(hsr, port) {
 169                 if (port->type == HSR_PT_MASTER)
 170                         continue;
 171                 switch (port->type) {
 172                 case HSR_PT_SLAVE_A:
 173                         designation = 'A';
 174                         break;
 175                 case HSR_PT_SLAVE_B:
 176                         designation = 'B';
 177                         break;
 178                 default:
 179                         designation = '?';
 180                 }
 181                 if (!is_slave_up(port->dev))
 182                         netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
 183                                     designation, port->dev->name);
 184         }
 185         rcu_read_unlock();
 186
 187         if (designation == '\0')
 188                 netdev_warn(dev, "No slave devices configured\n");
 189
 190         return 0;
 191 }
 192
 193
 194 static int hsr_dev_close(struct net_device *dev)
 195 {
 196         /* Nothing to do here. */
 197         return 0;
 198 }
 199
 200
 201 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
 202                                                 netdev_features_t features)
 203 {
 204         netdev_features_t mask;
 205         struct hsr_port *port;
 206
 207         mask = features;
 208
 209         /* Mask out all features that, if supported by one device, should be
 210          * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
 211          *
 212          * Anything that's off in mask will not be enabled - so only things
 213          * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
 214          * may become enabled.
 215          */
 216         features &= ~NETIF_F_ONE_FOR_ALL;
 217         hsr_for_each_port(hsr, port)
 218                 features = netdev_increment_features(features,
 219                                                      port->dev->features,
 220                                                      mask);
 221
 222         return features;
 223 }
 224
 225 static netdev_features_t hsr_fix_features(struct net_device *dev,
 226                                           netdev_features_t features)
 227 {
 228         struct hsr_priv *hsr = netdev_priv(dev);
 229
 230         return hsr_features_recompute(hsr, features);
 231 }
 232
 233
 234 static void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr)
 235 {
 236         unsigned long irqflags;
 237
 238         /* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values
 239          * between 0001-1001 ("ring identifier", for regular HSR frames),
 240          * or 1111 ("HSR management", supervision frames). Unfortunately, the
 241          * spec writers forgot to explain what a "ring identifier" is, or
 242          * how it is used. So we just set this to 0001 for regular frames,
 243          * and 1111 for supervision frames.
 244          */
 245         set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1);
 246
 247         /* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet
 248          * frame is the content of the frame located between the Length/Type
 249          * field and the Frame Check Sequence."
 250          *
 251          * IEC 62439-3, p 48, specifies the "original LPDU" to include the
 252          * original "LT" field (what "LT" means is not explained anywhere as
 253          * far as I can see - perhaps "Length/Type"?). So LSDU_size might
 254          * equal original length + 2.
 255          *   Also, the fact that this field is not used anywhere (might be used
 256          * by a RedBox connecting HSR and PRP nets?) means I cannot test its
 257          * correctness. Instead of guessing, I set this to 0 here, to make any
 258          * problems immediately apparent. Anyone using this driver with PRP/HSR
 259          * RedBoxes might need to fix this...
 260          */
 261         set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0);
 262
 263         spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
 264         hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr->sequence_nr);
 265         hsr->sequence_nr++;
 266         spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);
 267
 268         hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
 269
 270         hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
 271 }
 272
 273 static int slave_xmit(struct hsr_priv *hsr, struct sk_buff *skb,
 274                       enum hsr_port_type type)
 275 {
 276         struct hsr_port *port;
 277         struct hsr_ethhdr *hsr_ethhdr;
 278
 279         hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
 280
 281         rcu_read_lock();
 282         port = hsr_port_get_hsr(hsr, type);
 283         if (!port) {
 284                 rcu_read_unlock();
 285                 return NET_XMIT_DROP;
 286         }
 287         skb->dev = port->dev;
 288
 289         hsr_addr_subst_dest(port->hsr, &hsr_ethhdr->ethhdr, port);
 290         rcu_read_unlock();
 291
 292         /* Address substitution (IEC62439-3 pp 26, 50): replace mac
 293          * address of outgoing frame with that of the outgoing slave's.
 294          */
 295         ether_addr_copy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr);
 296
 297         return dev_queue_xmit(skb);
 298 }
 299
 300 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 301 {
 302         struct hsr_priv *hsr;
 303         struct hsr_port *master;
 304         struct hsr_ethhdr *hsr_ethhdr;
 305         struct sk_buff *skb2;
 306         int res1, res2;
 307
 308         hsr = netdev_priv(dev);
 309         hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
 310
 311         if ((skb->protocol != htons(ETH_P_PRP)) ||
 312             (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) {
 313                 hsr_fill_tag(hsr_ethhdr, hsr);
 314                 skb->protocol = htons(ETH_P_PRP);
 315         }
 316
 317         skb2 = pskb_copy(skb, GFP_ATOMIC);
 318
 319         res1 = slave_xmit(hsr, skb, HSR_PT_SLAVE_A);
 320         if (skb2)
 321                 res2 = slave_xmit(hsr, skb2, HSR_PT_SLAVE_B);
 322         else
 323                 res2 = NET_XMIT_DROP;
 324
 325         rcu_read_lock();
 326         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 327         if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN ||
 328                    res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) {
 329                 master->dev->stats.tx_packets++;
 330                 master->dev->stats.tx_bytes += skb->len;
 331         } else {
 332                 master->dev->stats.tx_dropped++;
 333         }
 334         rcu_read_unlock();
 335
 336         return NETDEV_TX_OK;
 337 }
 338
 339
 340 static int hsr_header_create(struct sk_buff *skb, struct net_device *dev,
 341                              unsigned short type, const void *daddr,
 342                              const void *saddr, unsigned int len)
 343 {
 344         int res;
 345
 346         /* Make room for the HSR tag now. We will fill it in later (in
 347          * hsr_dev_xmit)
 348          */
 349         if (skb_headroom(skb) < HSR_HLEN + ETH_HLEN)
 350                 return -ENOBUFS;
 351         skb_push(skb, HSR_HLEN);
 352
 353         /* To allow VLAN/HSR combos we should probably use
 354          * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
 355          * here instead. It would require other changes too, though - e.g.
 356          * separate headers for each slave etc...
 357          */
 358         res = eth_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
 359         if (res <= 0)
 360                 return res;
 361         skb_reset_mac_header(skb);
 362
 363         return res + HSR_HLEN;
 364 }
 365
 366
 367 static const struct header_ops hsr_header_ops = {
 368         .create  = hsr_header_create,
 369         .parse   = eth_header_parse,
 370 };
 371
 372
 373 /* HSR:2010 supervision frames should be padded so that the whole frame,
 374  * including headers and FCS, is 64 bytes (without VLAN).
 375  */
 376 static int hsr_pad(int size)
 377 {
 378         const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
 379
 380         if (size >= min_size)
 381                 return size;
 382         return min_size;
 383 }
 384
 385 static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type)
 386 {
 387         struct hsr_priv *hsr;
 388         struct hsr_port *master;
 389         struct sk_buff *skb;
 390         int hlen, tlen;
 391         struct hsr_sup_tag *hsr_stag;
 392         struct hsr_sup_payload *hsr_sp;
 393         unsigned long irqflags;
 394         int res;
 395
 396         hsr = netdev_priv(hsr_dev);
 397         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 398
 399         hlen = LL_RESERVED_SPACE(master->dev);
 400         tlen = master->dev->needed_tailroom;
 401         skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
 402                         GFP_ATOMIC);
 403
 404         if (skb == NULL)
 405                 return;
 406
 407         skb_reserve(skb, hlen);
 408
 409         skb->dev = master->dev;
 410         skb->protocol = htons(ETH_P_PRP);
 411         skb->priority = TC_PRIO_CONTROL;
 412
 413         res = dev_hard_header(skb, skb->dev, ETH_P_PRP,
 414                               hsr->sup_multicast_addr,
 415                               skb->dev->dev_addr, skb->len);
 416         if (res <= 0)
 417                 goto out;
 418
 419         skb_pull(skb, sizeof(struct ethhdr));
 420         hsr_stag = (typeof(hsr_stag)) skb->data;
 421
 422         set_hsr_stag_path(hsr_stag, 0xf);
 423         set_hsr_stag_HSR_Ver(hsr_stag, 0);
 424
 425         spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
 426         hsr_stag->sequence_nr = htons(hsr->sequence_nr);
 427         hsr->sequence_nr++;
 428         spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);
 429
 430         hsr_stag->HSR_TLV_Type = type;
 431         hsr_stag->HSR_TLV_Length = 12;
 432
 433         skb_push(skb, sizeof(struct ethhdr));
 434
 435         /* Payload: MacAddressA */
 436         hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
 437         ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 438
 439         dev_queue_xmit(skb);
 440         return;
 441
 442 out:
 443         WARN_ON_ONCE("HSR: Could not send supervision frame\n");
 444         kfree_skb(skb);
 445 }
 446
 447
 448 /* Announce (supervision frame) timer function
 449  */
 450 static void hsr_announce(unsigned long data)
 451 {
 452         struct hsr_priv *hsr;
 453         struct hsr_port *master;
 454
 455         hsr = (struct hsr_priv *) data;
 456         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 457
 458         if (hsr->announce_count < 3) {
 459                 send_hsr_supervision_frame(master->dev, HSR_TLV_ANNOUNCE);
 460                 hsr->announce_count++;
 461         } else {
 462                 send_hsr_supervision_frame(master->dev, HSR_TLV_LIFE_CHECK);
 463         }
 464
 465         if (hsr->announce_count < 3)
 466                 hsr->announce_timer.expires = jiffies +
 467                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 468         else
 469                 hsr->announce_timer.expires = jiffies +
 470                                 msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 471
 472         if (is_admin_up(master->dev))
 473                 add_timer(&hsr->announce_timer);
 474 }
 475
 476
 477 /* According to comments in the declaration of struct net_device, this function
 478  * is "Called from unregister, can be used to call free_netdev". Ok then...
 479  */
 480 static void hsr_dev_destroy(struct net_device *hsr_dev)
 481 {
 482         struct hsr_priv *hsr;
 483         struct hsr_port *port;
 484
 485         hsr = netdev_priv(hsr_dev);
 486         hsr_for_each_port(hsr, port)
 487                 hsr_del_port(port);
 488
 489         del_timer_sync(&hsr->prune_timer);
 490         del_timer_sync(&hsr->announce_timer);
 491
 492         synchronize_rcu();
 493         free_netdev(hsr_dev);
 494 }
 495
 496 static const struct net_device_ops hsr_device_ops = {
 497         .ndo_change_mtu = hsr_dev_change_mtu,
 498         .ndo_open = hsr_dev_open,
 499         .ndo_stop = hsr_dev_close,
 500         .ndo_start_xmit = hsr_dev_xmit,
 501         .ndo_fix_features = hsr_fix_features,
 502 };
 503
 504 static struct device_type hsr_type = {
 505         .name = "hsr",
 506 };
 507
 508 void hsr_dev_setup(struct net_device *dev)
 509 {
 510         random_ether_addr(dev->dev_addr);
 511
 512         ether_setup(dev);
 513         dev->header_ops = &hsr_header_ops;
 514         dev->netdev_ops = &hsr_device_ops;
 515         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 516         dev->tx_queue_len = 0;
 517
 518         dev->destructor = hsr_dev_destroy;
 519
 520         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 521                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 522                            NETIF_F_HW_VLAN_CTAG_TX;
 523
 524         dev->features = dev->hw_features;
 525
 526         /* Prevent recursive tx locking */
 527         dev->features |= NETIF_F_LLTX;
 528         /* VLAN on top of HSR needs testing and probably some work on
 529          * hsr_header_create() etc.
 530          */
 531         dev->features |= NETIF_F_VLAN_CHALLENGED;
 532         /* Not sure about this. Taken from bridge code. netdev_features.h says
 533          * it means "Does not change network namespaces".
 534          */
 535         dev->features |= NETIF_F_NETNS_LOCAL;
 536 }
 537
 538
 539 /* Return true if dev is a HSR master; return false otherwise.
 540  */
 541 inline bool is_hsr_master(struct net_device *dev)
 542 {
 543         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 544 }
 545
 546 /* Default multicast address for HSR Supervision frames */
 547 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 548         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 549 };
 550
 551 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 552                      unsigned char multicast_spec)
 553 {
 554         struct hsr_priv *hsr;
 555         struct hsr_port *port;
 556         int res;
 557
 558         hsr = netdev_priv(hsr_dev);
 559         INIT_LIST_HEAD(&hsr->ports);
 560         INIT_LIST_HEAD(&hsr->node_db);
 561         INIT_LIST_HEAD(&hsr->self_node_db);
 562
 563         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 564
 565         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 566         res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 567                                    slave[1]->dev_addr);
 568         if (res < 0)
 569                 return res;
 570
 571         spin_lock_init(&hsr->seqnr_lock);
 572         /* Overflow soon to find bugs easier: */
 573         hsr->sequence_nr = USHRT_MAX - 1024;
 574
 575         init_timer(&hsr->announce_timer);
 576         hsr->announce_timer.function = hsr_announce;
 577         hsr->announce_timer.data = (unsigned long) hsr;
 578
 579         init_timer(&hsr->prune_timer);
 580         hsr->prune_timer.function = hsr_prune_nodes;
 581         hsr->prune_timer.data = (unsigned long) hsr;
 582
 583         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 584         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 585
 586         /* FIXME: should I modify the value of these?
 587          *
 588          * - hsr_dev->flags - i.e.
 589          *                      IFF_MASTER/SLAVE?
 590          * - hsr_dev->priv_flags - i.e.
 591          *                      IFF_EBRIDGE?
 592          *                      IFF_TX_SKB_SHARING?
 593          *                      IFF_HSR_MASTER/SLAVE?
 594          */
 595
 596         /* Make sure the 1st call to netif_carrier_on() gets through */
 597         netif_carrier_off(hsr_dev);
 598
 599         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 600         if (res)
 601                 return res;
 602
 603         res = register_netdevice(hsr_dev);
 604         if (res)
 605                 goto fail;
 606
 607         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 608         if (res)
 609                 goto fail;
 610         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 611         if (res)
 612                 goto fail;
 613
 614         hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
 615         add_timer(&hsr->prune_timer);
 616
 617         return 0;
 618
 619 fail:
 620         hsr_for_each_port(hsr, port)
 621                 hsr_del_port(port);
 622
 623         return res;
 624 }