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 void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr)
 202 {
 203         unsigned long irqflags;
 204
 205         /* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values
 206          * between 0001-1001 ("ring identifier", for regular HSR frames),
 207          * or 1111 ("HSR management", supervision frames). Unfortunately, the
 208          * spec writers forgot to explain what a "ring identifier" is, or
 209          * how it is used. So we just set this to 0001 for regular frames,
 210          * and 1111 for supervision frames.
 211          */
 212         set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1);
 213
 214         /* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet
 215          * frame is the content of the frame located between the Length/Type
 216          * field and the Frame Check Sequence."
 217          *
 218          * IEC 62439-3, p 48, specifies the "original LPDU" to include the
 219          * original "LT" field (what "LT" means is not explained anywhere as
 220          * far as I can see - perhaps "Length/Type"?). So LSDU_size might
 221          * equal original length + 2.
 222          *   Also, the fact that this field is not used anywhere (might be used
 223          * by a RedBox connecting HSR and PRP nets?) means I cannot test its
 224          * correctness. Instead of guessing, I set this to 0 here, to make any
 225          * problems immediately apparent. Anyone using this driver with PRP/HSR
 226          * RedBoxes might need to fix this...
 227          */
 228         set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0);
 229
 230         spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
 231         hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr->sequence_nr);
 232         hsr->sequence_nr++;
 233         spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);
 234
 235         hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
 236
 237         hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
 238 }
 239
 240 static int slave_xmit(struct hsr_priv *hsr, struct sk_buff *skb,
 241                       enum hsr_port_type type)
 242 {
 243         struct hsr_port *port;
 244         struct hsr_ethhdr *hsr_ethhdr;
 245
 246         hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
 247
 248         rcu_read_lock();
 249         port = hsr_port_get_hsr(hsr, type);
 250         if (!port) {
 251                 rcu_read_unlock();
 252                 return NET_XMIT_DROP;
 253         }
 254         skb->dev = port->dev;
 255
 256         hsr_addr_subst_dest(port->hsr, &hsr_ethhdr->ethhdr, port);
 257         rcu_read_unlock();
 258
 259         /* Address substitution (IEC62439-3 pp 26, 50): replace mac
 260          * address of outgoing frame with that of the outgoing slave's.
 261          */
 262         ether_addr_copy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr);
 263
 264         return dev_queue_xmit(skb);
 265 }
 266
 267 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 268 {
 269         struct hsr_priv *hsr;
 270         struct hsr_port *master;
 271         struct hsr_ethhdr *hsr_ethhdr;
 272         struct sk_buff *skb2;
 273         int res1, res2;
 274
 275         hsr = netdev_priv(dev);
 276         hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
 277
 278         if ((skb->protocol != htons(ETH_P_PRP)) ||
 279             (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) {
 280                 hsr_fill_tag(hsr_ethhdr, hsr);
 281                 skb->protocol = htons(ETH_P_PRP);
 282         }
 283
 284         skb2 = pskb_copy(skb, GFP_ATOMIC);
 285
 286         res1 = slave_xmit(hsr, skb, HSR_PT_SLAVE_A);
 287         if (skb2)
 288                 res2 = slave_xmit(hsr, skb2, HSR_PT_SLAVE_B);
 289         else
 290                 res2 = NET_XMIT_DROP;
 291
 292         rcu_read_lock();
 293         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 294         if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN ||
 295                    res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) {
 296                 master->dev->stats.tx_packets++;
 297                 master->dev->stats.tx_bytes += skb->len;
 298         } else {
 299                 master->dev->stats.tx_dropped++;
 300         }
 301         rcu_read_unlock();
 302
 303         return NETDEV_TX_OK;
 304 }
 305
 306
 307 static int hsr_header_create(struct sk_buff *skb, struct net_device *dev,
 308                              unsigned short type, const void *daddr,
 309                              const void *saddr, unsigned int len)
 310 {
 311         int res;
 312
 313         /* Make room for the HSR tag now. We will fill it in later (in
 314          * hsr_dev_xmit)
 315          */
 316         if (skb_headroom(skb) < HSR_HLEN + ETH_HLEN)
 317                 return -ENOBUFS;
 318         skb_push(skb, HSR_HLEN);
 319
 320         /* To allow VLAN/HSR combos we should probably use
 321          * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
 322          * here instead. It would require other changes too, though - e.g.
 323          * separate headers for each slave etc...
 324          */
 325         res = eth_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
 326         if (res <= 0)
 327                 return res;
 328         skb_reset_mac_header(skb);
 329
 330         return res + HSR_HLEN;
 331 }
 332
 333
 334 static const struct header_ops hsr_header_ops = {
 335         .create  = hsr_header_create,
 336         .parse   = eth_header_parse,
 337 };
 338
 339
 340 /* HSR:2010 supervision frames should be padded so that the whole frame,
 341  * including headers and FCS, is 64 bytes (without VLAN).
 342  */
 343 static int hsr_pad(int size)
 344 {
 345         const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
 346
 347         if (size >= min_size)
 348                 return size;
 349         return min_size;
 350 }
 351
 352 static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type)
 353 {
 354         struct hsr_priv *hsr;
 355         struct hsr_port *master;
 356         struct sk_buff *skb;
 357         int hlen, tlen;
 358         struct hsr_sup_tag *hsr_stag;
 359         struct hsr_sup_payload *hsr_sp;
 360         unsigned long irqflags;
 361         int res;
 362
 363         hsr = netdev_priv(hsr_dev);
 364         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 365
 366         hlen = LL_RESERVED_SPACE(master->dev);
 367         tlen = master->dev->needed_tailroom;
 368         skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
 369                         GFP_ATOMIC);
 370
 371         if (skb == NULL)
 372                 return;
 373
 374         skb_reserve(skb, hlen);
 375
 376         skb->dev = master->dev;
 377         skb->protocol = htons(ETH_P_PRP);
 378         skb->priority = TC_PRIO_CONTROL;
 379
 380         res = dev_hard_header(skb, skb->dev, ETH_P_PRP,
 381                               hsr->sup_multicast_addr,
 382                               skb->dev->dev_addr, skb->len);
 383         if (res <= 0)
 384                 goto out;
 385
 386         skb_pull(skb, sizeof(struct ethhdr));
 387         hsr_stag = (typeof(hsr_stag)) skb->data;
 388
 389         set_hsr_stag_path(hsr_stag, 0xf);
 390         set_hsr_stag_HSR_Ver(hsr_stag, 0);
 391
 392         spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
 393         hsr_stag->sequence_nr = htons(hsr->sequence_nr);
 394         hsr->sequence_nr++;
 395         spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);
 396
 397         hsr_stag->HSR_TLV_Type = type;
 398         hsr_stag->HSR_TLV_Length = 12;
 399
 400         skb_push(skb, sizeof(struct ethhdr));
 401
 402         /* Payload: MacAddressA */
 403         hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
 404         ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 405
 406         dev_queue_xmit(skb);
 407         return;
 408
 409 out:
 410         WARN_ON_ONCE("HSR: Could not send supervision frame\n");
 411         kfree_skb(skb);
 412 }
 413
 414
 415 /* Announce (supervision frame) timer function
 416  */
 417 static void hsr_announce(unsigned long data)
 418 {
 419         struct hsr_priv *hsr;
 420         struct hsr_port *master;
 421
 422         hsr = (struct hsr_priv *) data;
 423         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 424
 425         if (hsr->announce_count < 3) {
 426                 send_hsr_supervision_frame(master->dev, HSR_TLV_ANNOUNCE);
 427                 hsr->announce_count++;
 428         } else {
 429                 send_hsr_supervision_frame(master->dev, HSR_TLV_LIFE_CHECK);
 430         }
 431
 432         if (hsr->announce_count < 3)
 433                 hsr->announce_timer.expires = jiffies +
 434                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 435         else
 436                 hsr->announce_timer.expires = jiffies +
 437                                 msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 438
 439         if (is_admin_up(master->dev))
 440                 add_timer(&hsr->announce_timer);
 441 }
 442
 443
 444 /* According to comments in the declaration of struct net_device, this function
 445  * is "Called from unregister, can be used to call free_netdev". Ok then...
 446  */
 447 static void hsr_dev_destroy(struct net_device *hsr_dev)
 448 {
 449         struct hsr_priv *hsr;
 450         struct hsr_port *port;
 451
 452         hsr = netdev_priv(hsr_dev);
 453         hsr_for_each_port(hsr, port)
 454                 hsr_del_port(port);
 455
 456         del_timer_sync(&hsr->prune_timer);
 457         del_timer_sync(&hsr->announce_timer);
 458
 459         synchronize_rcu();
 460         free_netdev(hsr_dev);
 461 }
 462
 463 static const struct net_device_ops hsr_device_ops = {
 464         .ndo_change_mtu = hsr_dev_change_mtu,
 465         .ndo_open = hsr_dev_open,
 466         .ndo_stop = hsr_dev_close,
 467         .ndo_start_xmit = hsr_dev_xmit,
 468 };
 469
 470
 471 void hsr_dev_setup(struct net_device *dev)
 472 {
 473         random_ether_addr(dev->dev_addr);
 474
 475         ether_setup(dev);
 476         dev->header_ops          = &hsr_header_ops;
 477         dev->netdev_ops          = &hsr_device_ops;
 478         dev->tx_queue_len        = 0;
 479
 480         dev->destructor = hsr_dev_destroy;
 481 }
 482
 483
 484 /* Return true if dev is a HSR master; return false otherwise.
 485  */
 486 inline bool is_hsr_master(struct net_device *dev)
 487 {
 488         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 489 }
 490
 491 /* Default multicast address for HSR Supervision frames */
 492 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 493         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 494 };
 495
 496 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 497                      unsigned char multicast_spec)
 498 {
 499         struct hsr_priv *hsr;
 500         struct hsr_port *port;
 501         int res;
 502
 503         hsr = netdev_priv(hsr_dev);
 504         INIT_LIST_HEAD(&hsr->ports);
 505         INIT_LIST_HEAD(&hsr->node_db);
 506         INIT_LIST_HEAD(&hsr->self_node_db);
 507
 508         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 509
 510         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 511         res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 512                                    slave[1]->dev_addr);
 513         if (res < 0)
 514                 return res;
 515
 516         hsr_dev->features = slave[0]->features & slave[1]->features;
 517         /* Prevent recursive tx locking */
 518         hsr_dev->features |= NETIF_F_LLTX;
 519         /* VLAN on top of HSR needs testing and probably some work on
 520          * hsr_header_create() etc.
 521          */
 522         hsr_dev->features |= NETIF_F_VLAN_CHALLENGED;
 523
 524         spin_lock_init(&hsr->seqnr_lock);
 525         /* Overflow soon to find bugs easier: */
 526         hsr->sequence_nr = USHRT_MAX - 1024;
 527
 528         init_timer(&hsr->announce_timer);
 529         hsr->announce_timer.function = hsr_announce;
 530         hsr->announce_timer.data = (unsigned long) hsr;
 531
 532         init_timer(&hsr->prune_timer);
 533         hsr->prune_timer.function = hsr_prune_nodes;
 534         hsr->prune_timer.data = (unsigned long) hsr;
 535
 536         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 537         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 538
 539         /* FIXME: should I modify the value of these?
 540          *
 541          * - hsr_dev->flags - i.e.
 542          *                      IFF_MASTER/SLAVE?
 543          * - hsr_dev->priv_flags - i.e.
 544          *                      IFF_EBRIDGE?
 545          *                      IFF_TX_SKB_SHARING?
 546          *                      IFF_HSR_MASTER/SLAVE?
 547          */
 548
 549         /* Make sure the 1st call to netif_carrier_on() gets through */
 550         netif_carrier_off(hsr_dev);
 551
 552         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 553         if (res)
 554                 return res;
 555
 556         res = register_netdevice(hsr_dev);
 557         if (res)
 558                 goto fail;
 559
 560         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 561         if (res)
 562                 goto fail;
 563         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 564         if (res)
 565                 goto fail;
 566
 567         hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
 568         add_timer(&hsr->prune_timer);
 569
 570         return 0;
 571
 572 fail:
 573         hsr_for_each_port(hsr, port)
 574                 hsr_del_port(port);
 575
 576         return res;
 577 }