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 #include "hsr_forward.h"
  25
  26
  27 static bool is_admin_up(struct net_device *dev)
  28 {
  29         return dev && (dev->flags & IFF_UP);
  30 }
  31
  32 static bool is_slave_up(struct net_device *dev)
  33 {
  34         return dev && is_admin_up(dev) && netif_oper_up(dev);
  35 }
  36
  37 static void __hsr_set_operstate(struct net_device *dev, int transition)
  38 {
  39         write_lock_bh(&dev_base_lock);
  40         if (dev->operstate != transition) {
  41                 dev->operstate = transition;
  42                 write_unlock_bh(&dev_base_lock);
  43                 netdev_state_change(dev);
  44         } else {
  45                 write_unlock_bh(&dev_base_lock);
  46         }
  47 }
  48
  49 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
  50 {
  51         if (!is_admin_up(master->dev)) {
  52                 __hsr_set_operstate(master->dev, IF_OPER_DOWN);
  53                 return;
  54         }
  55
  56         if (has_carrier)
  57                 __hsr_set_operstate(master->dev, IF_OPER_UP);
  58         else
  59                 __hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
  60 }
  61
  62 static bool hsr_check_carrier(struct hsr_port *master)
  63 {
  64         struct hsr_port *port;
  65         bool has_carrier;
  66
  67         has_carrier = false;
  68
  69         rcu_read_lock();
  70         hsr_for_each_port(master->hsr, port)
  71                 if ((port->type != HSR_PT_MASTER) && is_slave_up(port->dev)) {
  72                         has_carrier = true;
  73                         break;
  74                 }
  75         rcu_read_unlock();
  76
  77         if (has_carrier)
  78                 netif_carrier_on(master->dev);
  79         else
  80                 netif_carrier_off(master->dev);
  81
  82         return has_carrier;
  83 }
  84
  85
  86 static void hsr_check_announce(struct net_device *hsr_dev,
  87                                unsigned char old_operstate)
  88 {
  89         struct hsr_priv *hsr;
  90
  91         hsr = netdev_priv(hsr_dev);
  92
  93         if ((hsr_dev->operstate == IF_OPER_UP)
  94                         && (old_operstate != IF_OPER_UP)) {
  95                 /* Went up */
  96                 hsr->announce_count = 0;
  97                 hsr->announce_timer.expires = jiffies +
  98                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
  99                 add_timer(&hsr->announce_timer);
 100         }
 101
 102         if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
 103                 /* Went down */
 104                 del_timer(&hsr->announce_timer);
 105 }
 106
 107 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
 108 {
 109         struct hsr_port *master;
 110         unsigned char old_operstate;
 111         bool has_carrier;
 112
 113         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 114         /* netif_stacked_transfer_operstate() cannot be used here since
 115          * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
 116          */
 117         old_operstate = master->dev->operstate;
 118         has_carrier = hsr_check_carrier(master);
 119         hsr_set_operstate(master, has_carrier);
 120         hsr_check_announce(master->dev, old_operstate);
 121 }
 122
 123 int hsr_get_max_mtu(struct hsr_priv *hsr)
 124 {
 125         unsigned int mtu_max;
 126         struct hsr_port *port;
 127
 128         mtu_max = ETH_DATA_LEN;
 129         rcu_read_lock();
 130         hsr_for_each_port(hsr, port)
 131                 if (port->type != HSR_PT_MASTER)
 132                         mtu_max = min(port->dev->mtu, mtu_max);
 133         rcu_read_unlock();
 134
 135         if (mtu_max < HSR_HLEN)
 136                 return 0;
 137         return mtu_max - HSR_HLEN;
 138 }
 139
 140
 141 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
 142 {
 143         struct hsr_priv *hsr;
 144         struct hsr_port *master;
 145
 146         hsr = netdev_priv(dev);
 147         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 148
 149         if (new_mtu > hsr_get_max_mtu(hsr)) {
 150                 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",
 151                             HSR_HLEN);
 152                 return -EINVAL;
 153         }
 154
 155         dev->mtu = new_mtu;
 156
 157         return 0;
 158 }
 159
 160 static int hsr_dev_open(struct net_device *dev)
 161 {
 162         struct hsr_priv *hsr;
 163         struct hsr_port *port;
 164         char designation;
 165
 166         hsr = netdev_priv(dev);
 167         designation = '\0';
 168
 169         rcu_read_lock();
 170         hsr_for_each_port(hsr, port) {
 171                 if (port->type == HSR_PT_MASTER)
 172                         continue;
 173                 switch (port->type) {
 174                 case HSR_PT_SLAVE_A:
 175                         designation = 'A';
 176                         break;
 177                 case HSR_PT_SLAVE_B:
 178                         designation = 'B';
 179                         break;
 180                 default:
 181                         designation = '?';
 182                 }
 183                 if (!is_slave_up(port->dev))
 184                         netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
 185                                     designation, port->dev->name);
 186         }
 187         rcu_read_unlock();
 188
 189         if (designation == '\0')
 190                 netdev_warn(dev, "No slave devices configured\n");
 191
 192         return 0;
 193 }
 194
 195
 196 static int hsr_dev_close(struct net_device *dev)
 197 {
 198         /* Nothing to do here. */
 199         return 0;
 200 }
 201
 202
 203 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
 204                                                 netdev_features_t features)
 205 {
 206         netdev_features_t mask;
 207         struct hsr_port *port;
 208
 209         mask = features;
 210
 211         /* Mask out all features that, if supported by one device, should be
 212          * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
 213          *
 214          * Anything that's off in mask will not be enabled - so only things
 215          * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
 216          * may become enabled.
 217          */
 218         features &= ~NETIF_F_ONE_FOR_ALL;
 219         hsr_for_each_port(hsr, port)
 220                 features = netdev_increment_features(features,
 221                                                      port->dev->features,
 222                                                      mask);
 223
 224         return features;
 225 }
 226
 227 static netdev_features_t hsr_fix_features(struct net_device *dev,
 228                                           netdev_features_t features)
 229 {
 230         struct hsr_priv *hsr = netdev_priv(dev);
 231
 232         return hsr_features_recompute(hsr, features);
 233 }
 234
 235
 236 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 237 {
 238         struct hsr_priv *hsr = netdev_priv(dev);
 239         struct hsr_port *master;
 240
 241         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 242         skb->dev = master->dev;
 243         hsr_forward_skb(skb, master);
 244
 245         return NETDEV_TX_OK;
 246 }
 247
 248
 249 static const struct header_ops hsr_header_ops = {
 250         .create  = eth_header,
 251         .parse   = eth_header_parse,
 252 };
 253
 254 static void send_hsr_supervision_frame(struct hsr_port *master,
 255                 u8 type, u8 hsrVer)
 256 {
 257         struct sk_buff *skb;
 258         int hlen, tlen;
 259         struct hsr_tag *hsr_tag;
 260         struct hsr_sup_tag *hsr_stag;
 261         struct hsr_sup_payload *hsr_sp;
 262         unsigned long irqflags;
 263
 264         hlen = LL_RESERVED_SPACE(master->dev);
 265         tlen = master->dev->needed_tailroom;
 266         skb = dev_alloc_skb(
 267                         sizeof(struct hsr_tag) +
 268                         sizeof(struct hsr_sup_tag) +
 269                         sizeof(struct hsr_sup_payload) + hlen + tlen);
 270
 271         if (skb == NULL)
 272                 return;
 273
 274         skb_reserve(skb, hlen);
 275
 276         skb->dev = master->dev;
 277         skb->protocol = htons(hsrVer ? ETH_P_HSR : ETH_P_PRP);
 278         skb->priority = TC_PRIO_CONTROL;
 279
 280         if (dev_hard_header(skb, skb->dev, (hsrVer ? ETH_P_HSR : ETH_P_PRP),
 281                             master->hsr->sup_multicast_addr,
 282                             skb->dev->dev_addr, skb->len) <= 0)
 283                 goto out;
 284         skb_reset_mac_header(skb);
 285
 286         if (hsrVer > 0) {
 287                 hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
 288                 hsr_tag->encap_proto = htons(ETH_P_PRP);
 289                 set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
 290         }
 291
 292         hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
 293         set_hsr_stag_path(hsr_stag, (hsrVer ? 0x0 : 0xf));
 294         set_hsr_stag_HSR_Ver(hsr_stag, hsrVer);
 295
 296         /* From HSRv1 on we have separate supervision sequence numbers. */
 297         spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
 298         if (hsrVer > 0) {
 299                 hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
 300                 hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
 301                 master->hsr->sup_sequence_nr++;
 302                 master->hsr->sequence_nr++;
 303         } else {
 304                 hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
 305                 master->hsr->sequence_nr++;
 306         }
 307         spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 308
 309         hsr_stag->HSR_TLV_Type = type;
 310         /* TODO: Why 12 in HSRv0? */
 311         hsr_stag->HSR_TLV_Length = hsrVer ? sizeof(struct hsr_sup_payload) : 12;
 312
 313         /* Payload: MacAddressA */
 314         hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
 315         ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 316
 317         if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
 318                 return;
 319
 320         hsr_forward_skb(skb, master);
 321         return;
 322
 323 out:
 324         WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 325         kfree_skb(skb);
 326 }
 327
 328
 329 /* Announce (supervision frame) timer function
 330  */
 331 static void hsr_announce(unsigned long data)
 332 {
 333         struct hsr_priv *hsr;
 334         struct hsr_port *master;
 335
 336         hsr = (struct hsr_priv *) data;
 337
 338         rcu_read_lock();
 339         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 340
 341         if (hsr->announce_count < 3 && hsr->protVersion == 0) {
 342                 send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
 343                                 hsr->protVersion);
 344                 hsr->announce_count++;
 345
 346                 hsr->announce_timer.expires = jiffies +
 347                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 348         } else {
 349                 send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
 350                                 hsr->protVersion);
 351
 352                 hsr->announce_timer.expires = jiffies +
 353                                 msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 354         }
 355
 356         if (is_admin_up(master->dev))
 357                 add_timer(&hsr->announce_timer);
 358
 359         rcu_read_unlock();
 360 }
 361
 362
 363 /* According to comments in the declaration of struct net_device, this function
 364  * is "Called from unregister, can be used to call free_netdev". Ok then...
 365  */
 366 static void hsr_dev_destroy(struct net_device *hsr_dev)
 367 {
 368         struct hsr_priv *hsr;
 369         struct hsr_port *port;
 370
 371         hsr = netdev_priv(hsr_dev);
 372
 373         rtnl_lock();
 374         hsr_for_each_port(hsr, port)
 375                 hsr_del_port(port);
 376         rtnl_unlock();
 377
 378         del_timer_sync(&hsr->prune_timer);
 379         del_timer_sync(&hsr->announce_timer);
 380
 381         synchronize_rcu();
 382 }
 383
 384 static const struct net_device_ops hsr_device_ops = {
 385         .ndo_change_mtu = hsr_dev_change_mtu,
 386         .ndo_open = hsr_dev_open,
 387         .ndo_stop = hsr_dev_close,
 388         .ndo_start_xmit = hsr_dev_xmit,
 389         .ndo_fix_features = hsr_fix_features,
 390 };
 391
 392 static struct device_type hsr_type = {
 393         .name = "hsr",
 394 };
 395
 396 void hsr_dev_setup(struct net_device *dev)
 397 {
 398         eth_hw_addr_random(dev);
 399
 400         ether_setup(dev);
 401         dev->min_mtu = 0;
 402         dev->header_ops = &hsr_header_ops;
 403         dev->netdev_ops = &hsr_device_ops;
 404         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 405         dev->priv_flags |= IFF_NO_QUEUE;
 406
 407         dev->needs_free_netdev = true;
 408         dev->priv_destructor = hsr_dev_destroy;
 409
 410         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 411                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 412                            NETIF_F_HW_VLAN_CTAG_TX;
 413
 414         dev->features = dev->hw_features;
 415
 416         /* Prevent recursive tx locking */
 417         dev->features |= NETIF_F_LLTX;
 418         /* VLAN on top of HSR needs testing and probably some work on
 419          * hsr_header_create() etc.
 420          */
 421         dev->features |= NETIF_F_VLAN_CHALLENGED;
 422         /* Not sure about this. Taken from bridge code. netdev_features.h says
 423          * it means "Does not change network namespaces".
 424          */
 425         dev->features |= NETIF_F_NETNS_LOCAL;
 426 }
 427
 428
 429 /* Return true if dev is a HSR master; return false otherwise.
 430  */
 431 inline bool is_hsr_master(struct net_device *dev)
 432 {
 433         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 434 }
 435
 436 /* Default multicast address for HSR Supervision frames */
 437 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 438         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 439 };
 440
 441 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 442                      unsigned char multicast_spec, u8 protocol_version)
 443 {
 444         struct hsr_priv *hsr;
 445         struct hsr_port *port;
 446         int res;
 447
 448         hsr = netdev_priv(hsr_dev);
 449         INIT_LIST_HEAD(&hsr->ports);
 450         INIT_LIST_HEAD(&hsr->node_db);
 451         INIT_LIST_HEAD(&hsr->self_node_db);
 452
 453         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 454
 455         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 456         res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 457                                    slave[1]->dev_addr);
 458         if (res < 0)
 459                 return res;
 460
 461         spin_lock_init(&hsr->seqnr_lock);
 462         /* Overflow soon to find bugs easier: */
 463         hsr->sequence_nr = HSR_SEQNR_START;
 464         hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
 465
 466         setup_timer(&hsr->announce_timer, hsr_announce, (unsigned long)hsr);
 467
 468         setup_timer(&hsr->prune_timer, hsr_prune_nodes, (unsigned long)hsr);
 469
 470         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 471         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 472
 473         hsr->protVersion = protocol_version;
 474
 475         /* FIXME: should I modify the value of these?
 476          *
 477          * - hsr_dev->flags - i.e.
 478          *                      IFF_MASTER/SLAVE?
 479          * - hsr_dev->priv_flags - i.e.
 480          *                      IFF_EBRIDGE?
 481          *                      IFF_TX_SKB_SHARING?
 482          *                      IFF_HSR_MASTER/SLAVE?
 483          */
 484
 485         /* Make sure the 1st call to netif_carrier_on() gets through */
 486         netif_carrier_off(hsr_dev);
 487
 488         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 489         if (res)
 490                 return res;
 491
 492         res = register_netdevice(hsr_dev);
 493         if (res)
 494                 goto fail;
 495
 496         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 497         if (res)
 498                 goto fail;
 499         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 500         if (res)
 501                 goto fail;
 502
 503         mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
 504
 505         return 0;
 506
 507 fail:
 508         hsr_for_each_port(hsr, port)
 509                 hsr_del_port(port);
 510
 511         return res;
 512 }