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                 mod_timer(&hsr->announce_timer,
  97                           jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
  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 int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 235 {
 236         struct hsr_priv *hsr = netdev_priv(dev);
 237         struct hsr_port *master;
 238
 239         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 240         skb->dev = master->dev;
 241         hsr_forward_skb(skb, master);
 242
 243         return NETDEV_TX_OK;
 244 }
 245
 246
 247 static const struct header_ops hsr_header_ops = {
 248         .create  = eth_header,
 249         .parse   = eth_header_parse,
 250 };
 251
 252
 253 /* HSR:2010 supervision frames should be padded so that the whole frame,
 254  * including headers and FCS, is 64 bytes (without VLAN).
 255  */
 256 static int hsr_pad(int size)
 257 {
 258         const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
 259
 260         if (size >= min_size)
 261                 return size;
 262         return min_size;
 263 }
 264
 265 static void send_hsr_supervision_frame(struct hsr_port *master, u8 type)
 266 {
 267         struct sk_buff *skb;
 268         int hlen, tlen;
 269         struct hsr_sup_tag *hsr_stag;
 270         struct hsr_sup_payload *hsr_sp;
 271         unsigned long irqflags;
 272
 273         hlen = LL_RESERVED_SPACE(master->dev);
 274         tlen = master->dev->needed_tailroom;
 275         skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
 276                         GFP_ATOMIC);
 277
 278         if (skb == NULL)
 279                 return;
 280
 281         skb_reserve(skb, hlen);
 282
 283         skb->dev = master->dev;
 284         skb->protocol = htons(ETH_P_PRP);
 285         skb->priority = TC_PRIO_CONTROL;
 286
 287         if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
 288                             master->hsr->sup_multicast_addr,
 289                             skb->dev->dev_addr, skb->len) <= 0)
 290                 goto out;
 291         skb_reset_mac_header(skb);
 292         skb_reset_network_header(skb);
 293         skb_reset_transport_header(skb);
 294
 295         hsr_stag = (typeof(hsr_stag)) skb_put(skb, sizeof(*hsr_stag));
 296
 297         set_hsr_stag_path(hsr_stag, 0xf);
 298         set_hsr_stag_HSR_Ver(hsr_stag, 0);
 299
 300         spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
 301         hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
 302         master->hsr->sequence_nr++;
 303         spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
 304
 305         hsr_stag->HSR_TLV_Type = type;
 306         hsr_stag->HSR_TLV_Length = 12;
 307
 308         /* Payload: MacAddressA */
 309         hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
 310         ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 311
 312         hsr_forward_skb(skb, master);
 313         return;
 314
 315 out:
 316         WARN_ONCE(1, "HSR: Could not send supervision frame\n");
 317         kfree_skb(skb);
 318 }
 319
 320
 321 /* Announce (supervision frame) timer function
 322  */
 323 static void hsr_announce(unsigned long data)
 324 {
 325         struct hsr_priv *hsr;
 326         struct hsr_port *master;
 327         unsigned long interval;
 328
 329         hsr = (struct hsr_priv *) data;
 330
 331         rcu_read_lock();
 332         master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 333
 334         if (hsr->announce_count < 3) {
 335                 send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE);
 336                 hsr->announce_count++;
 337         } else {
 338                 send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK);
 339         }
 340
 341         if (hsr->announce_count < 3)
 342                 interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
 343         else
 344                 interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
 345
 346         if (is_admin_up(master->dev))
 347                 mod_timer(&hsr->announce_timer, jiffies + interval);
 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                 goto err_add_port;
 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 err_add_port:
 502         hsr_del_node(&hsr->self_node_db);
 503
 504         return res;
 505 }