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