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) && (old_operstate != IF_OPER_UP)) {
  94                 /* Went up */
  95                 hsr->announce_count = 0;
  96                 hsr->announce_timer.expires = jiffies +
  97                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
  98                 add_timer(&hsr->announce_timer);
  99         }
 100
 101         if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
 102                 /* Went down */
 103                 del_timer(&hsr->announce_timer);
 104 }
 105
 106 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
 107 {
 108         struct hsr_port *master;
 109         unsigned char old_operstate;
 110         bool has_carrier;
 111
 112         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 113         /* netif_stacked_transfer_operstate() cannot be used here since
 114          * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
 115          */
 116         old_operstate = master->dev->operstate;
 117         has_carrier = hsr_check_carrier(master);
 118         hsr_set_operstate(master, has_carrier);
 119         hsr_check_announce(master->dev, old_operstate);
 120 }
 121
 122 int hsr_get_max_mtu(struct hsr_priv *hsr)
 123 {
 124         unsigned int mtu_max;
 125         struct hsr_port *port;
 126
 127         mtu_max = ETH_DATA_LEN;
 128         rcu_read_lock();
 129         hsr_for_each_port(hsr, port)
 130                 if (port->type != HSR_PT_MASTER)
 131                         mtu_max = min(port->dev->mtu, mtu_max);
 132         rcu_read_unlock();
 133
 134         if (mtu_max < HSR_HLEN)
 135                 return 0;
 136         return mtu_max - HSR_HLEN;
 137 }
 138
 139
 140 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
 141 {
 142         struct hsr_priv *hsr;
 143         struct hsr_port *master;
 144
 145         hsr = netdev_priv(dev);
 146         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 147
 148         if (new_mtu > hsr_get_max_mtu(hsr)) {
 149                 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",
 150                             HSR_HLEN);
 151                 return -EINVAL;
 152         }
 153
 154         dev->mtu = new_mtu;
 155
 156         return 0;
 157 }
 158
 159 static int hsr_dev_open(struct net_device *dev)
 160 {
 161         struct hsr_priv *hsr;
 162         struct hsr_port *port;
 163         char designation;
 164
 165         hsr = netdev_priv(dev);
 166         designation = '\0';
 167
 168         rcu_read_lock();
 169         hsr_for_each_port(hsr, port) {
 170                 if (port->type == HSR_PT_MASTER)
 171                         continue;
 172                 switch (port->type) {
 173                 case HSR_PT_SLAVE_A:
 174                         designation = 'A';
 175                         break;
 176                 case HSR_PT_SLAVE_B:
 177                         designation = 'B';
 178                         break;
 179                 default:
 180                         designation = '?';
 181                 }
 182                 if (!is_slave_up(port->dev))
 183                         netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
 184                                     designation, port->dev->name);
 185         }
 186         rcu_read_unlock();
 187
 188         if (designation == '\0')
 189                 netdev_warn(dev, "No slave devices configured\n");
 190
 191         return 0;
 192 }
 193
 194
 195 static int hsr_dev_close(struct net_device *dev)
 196 {
 197         /* Nothing to do here. */
 198         return 0;
 199 }
 200
 201
 202 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
 203                                                 netdev_features_t features)
 204 {
 205         netdev_features_t mask;
 206         struct hsr_port *port;
 207
 208         mask = features;
 209
 210         /* Mask out all features that, if supported by one device, should be
 211          * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
 212          *
 213          * Anything that's off in mask will not be enabled - so only things
 214          * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
 215          * may become enabled.
 216          */
 217         features &= ~NETIF_F_ONE_FOR_ALL;
 218         hsr_for_each_port(hsr, port)
 219                 features = netdev_increment_features(features,
 220                                                      port->dev->features,
 221                                                      mask);
 222
 223         return features;
 224 }
 225
 226 static netdev_features_t hsr_fix_features(struct net_device *dev,
 227                                           netdev_features_t features)
 228 {
 229         struct hsr_priv *hsr = netdev_priv(dev);
 230
 231         return hsr_features_recompute(hsr, features);
 232 }
 233
 234
 235 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 236 {
 237         struct hsr_priv *hsr = netdev_priv(dev);
 238         struct hsr_port *master;
 239
 240         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 241         skb->dev = master->dev;
 242         hsr_forward_skb(skb, master);
 243
 244         return NETDEV_TX_OK;
 245 }
 246
 247
 248 static const struct header_ops hsr_header_ops = {
 249         .create  = eth_header,
 250         .parse   = eth_header_parse,
 251 };
 252
 253
 254 /* HSR:2010 supervision frames should be padded so that the whole frame,
 255  * including headers and FCS, is 64 bytes (without VLAN).
 256  */
 257 static int hsr_pad(int size)
 258 {
 259         const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
 260
 261         if (size >= min_size)
 262                 return size;
 263         return min_size;
 264 }
 265
 266 static void send_hsr_supervision_frame(struct hsr_port *master, u8 type)
 267 {
 268         struct sk_buff *skb;
 269         int hlen, tlen;
 270         struct hsr_sup_tag *hsr_stag;
 271         struct hsr_sup_payload *hsr_sp;
 272         unsigned long irqflags;
 273
 274         hlen = LL_RESERVED_SPACE(master->dev);
 275         tlen = master->dev->needed_tailroom;
 276         skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
 277                         GFP_ATOMIC);
 278
 279         if (skb == NULL)
 280                 return;
 281
 282         skb_reserve(skb, hlen);
 283
 284         skb->dev = master->dev;
 285         skb->protocol = htons(ETH_P_PRP);
 286         skb->priority = TC_PRIO_CONTROL;
 287
 288         if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
 289                             master->hsr->sup_multicast_addr,
 290                             skb->dev->dev_addr, skb->len) <= 0)
 291                 goto out;
 292         skb_reset_mac_header(skb);
 293
 294         hsr_stag = (typeof(hsr_stag)) skb_put(skb, sizeof(*hsr_stag));
 295
 296         set_hsr_stag_path(hsr_stag, 0xf);
 297         set_hsr_stag_HSR_Ver(hsr_stag, 0);
 298
 299         spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
 300         hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
 301         master->hsr->sequence_nr++;
 302         spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 303
 304         hsr_stag->HSR_TLV_Type = type;
 305         hsr_stag->HSR_TLV_Length = 12;
 306
 307         /* Payload: MacAddressA */
 308         hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
 309         ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 310
 311         hsr_forward_skb(skb, master);
 312         return;
 313
 314 out:
 315         WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 316         kfree_skb(skb);
 317 }
 318
 319
 320 /* Announce (supervision frame) timer function
 321  */
 322 static void hsr_announce(unsigned long data)
 323 {
 324         struct hsr_priv *hsr;
 325         struct hsr_port *master;
 326
 327         hsr = (struct hsr_priv *) data;
 328
 329         rcu_read_lock();
 330         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 331
 332         if (hsr->announce_count < 3) {
 333                 send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE);
 334                 hsr->announce_count++;
 335         } else {
 336                 send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK);
 337         }
 338
 339         if (hsr->announce_count < 3)
 340                 hsr->announce_timer.expires = jiffies +
 341                                 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 342         else
 343                 hsr->announce_timer.expires = jiffies +
 344                                 msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 345
 346         if (is_admin_up(master->dev))
 347                 add_timer(&hsr->announce_timer);
 348
 349         rcu_read_unlock();
 350 }
 351
 352
 353 /* According to comments in the declaration of struct net_device, this function
 354  * is "Called from unregister, can be used to call free_netdev". Ok then...
 355  */
 356 static void hsr_dev_destroy(struct net_device *hsr_dev)
 357 {
 358         struct hsr_priv *hsr;
 359         struct hsr_port *port;
 360
 361         hsr = netdev_priv(hsr_dev);
 362
 363         rtnl_lock();
 364         hsr_for_each_port(hsr, port)
 365                 hsr_del_port(port);
 366         rtnl_unlock();
 367
 368         del_timer_sync(&hsr->prune_timer);
 369         del_timer_sync(&hsr->announce_timer);
 370
 371         synchronize_rcu();
 372         free_netdev(hsr_dev);
 373 }
 374
 375 static const struct net_device_ops hsr_device_ops = {
 376         .ndo_change_mtu = hsr_dev_change_mtu,
 377         .ndo_open = hsr_dev_open,
 378         .ndo_stop = hsr_dev_close,
 379         .ndo_start_xmit = hsr_dev_xmit,
 380         .ndo_fix_features = hsr_fix_features,
 381 };
 382
 383 static struct device_type hsr_type = {
 384         .name = "hsr",
 385 };
 386
 387 void hsr_dev_setup(struct net_device *dev)
 388 {
 389         random_ether_addr(dev->dev_addr);
 390
 391         ether_setup(dev);
 392         dev->header_ops = &hsr_header_ops;
 393         dev->netdev_ops = &hsr_device_ops;
 394         SET_NETDEV_DEVTYPE(dev, &hsr_type);
 395         dev->priv_flags |= IFF_NO_QUEUE;
 396
 397         dev->destructor = hsr_dev_destroy;
 398
 399         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 400                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 401                            NETIF_F_HW_VLAN_CTAG_TX;
 402
 403         dev->features = dev->hw_features;
 404
 405         /* Prevent recursive tx locking */
 406         dev->features |= NETIF_F_LLTX;
 407         /* VLAN on top of HSR needs testing and probably some work on
 408          * hsr_header_create() etc.
 409          */
 410         dev->features |= NETIF_F_VLAN_CHALLENGED;
 411         /* Not sure about this. Taken from bridge code. netdev_features.h says
 412          * it means "Does not change network namespaces".
 413          */
 414         dev->features |= NETIF_F_NETNS_LOCAL;
 415 }
 416
 417
 418 /* Return true if dev is a HSR master; return false otherwise.
 419  */
 420 inline bool is_hsr_master(struct net_device *dev)
 421 {
 422         return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
 423 }
 424
 425 /* Default multicast address for HSR Supervision frames */
 426 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 427         0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
 428 };
 429
 430 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 431                      unsigned char multicast_spec)
 432 {
 433         struct hsr_priv *hsr;
 434         struct hsr_port *port;
 435         int res;
 436
 437         hsr = netdev_priv(hsr_dev);
 438         INIT_LIST_HEAD(&hsr->ports);
 439         INIT_LIST_HEAD(&hsr->node_db);
 440         INIT_LIST_HEAD(&hsr->self_node_db);
 441
 442         ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
 443
 444         /* Make sure we recognize frames from ourselves in hsr_rcv() */
 445         res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
 446                                    slave[1]->dev_addr);
 447         if (res < 0)
 448                 return res;
 449
 450         spin_lock_init(&hsr->seqnr_lock);
 451         /* Overflow soon to find bugs easier: */
 452         hsr->sequence_nr = HSR_SEQNR_START;
 453
 454         init_timer(&hsr->announce_timer);
 455         hsr->announce_timer.function = hsr_announce;
 456         hsr->announce_timer.data = (unsigned long) hsr;
 457
 458         init_timer(&hsr->prune_timer);
 459         hsr->prune_timer.function = hsr_prune_nodes;
 460         hsr->prune_timer.data = (unsigned long) hsr;
 461
 462         ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
 463         hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
 464
 465         /* FIXME: should I modify the value of these?
 466          *
 467          * - hsr_dev->flags - i.e.
 468          *                      IFF_MASTER/SLAVE?
 469          * - hsr_dev->priv_flags - i.e.
 470          *                      IFF_EBRIDGE?
 471          *                      IFF_TX_SKB_SHARING?
 472          *                      IFF_HSR_MASTER/SLAVE?
 473          */
 474
 475         /* Make sure the 1st call to netif_carrier_on() gets through */
 476         netif_carrier_off(hsr_dev);
 477
 478         res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
 479         if (res)
 480                 return res;
 481
 482         res = register_netdevice(hsr_dev);
 483         if (res)
 484                 goto fail;
 485
 486         res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
 487         if (res)
 488                 goto fail;
 489         res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
 490         if (res)
 491                 goto fail;
 492
 493         hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
 494         add_timer(&hsr->prune_timer);
 495
 496         return 0;
 497
 498 fail:
 499         hsr_for_each_port(hsr, port)
 500                 hsr_del_port(port);
 501
 502         return res;
 503 }