summaryrefslogtreecommitdiff
path: root/net/hsr/hsr_device.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/hsr/hsr_device.c')
-rw-r--r--net/hsr/hsr_device.c596
1 files changed, 596 insertions, 0 deletions
diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
new file mode 100644
index 000000000000..cac505f166d5
--- /dev/null
+++ b/net/hsr/hsr_device.c
@@ -0,0 +1,596 @@
+/* Copyright 2011-2013 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ * 2011-2013 Arvid Brodin, arvid.brodin@xdin.com
+ *
+ * This file contains device methods for creating, using and destroying
+ * virtual HSR devices.
+ */
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <linux/pkt_sched.h>
+#include "hsr_device.h"
+#include "hsr_framereg.h"
+#include "hsr_main.h"
+
+
+static bool is_admin_up(struct net_device *dev)
+{
+ return dev && (dev->flags & IFF_UP);
+}
+
+static bool is_slave_up(struct net_device *dev)
+{
+ return dev && is_admin_up(dev) && netif_oper_up(dev);
+}
+
+static void __hsr_set_operstate(struct net_device *dev, int transition)
+{
+ write_lock_bh(&dev_base_lock);
+ if (dev->operstate != transition) {
+ dev->operstate = transition;
+ write_unlock_bh(&dev_base_lock);
+ netdev_state_change(dev);
+ } else {
+ write_unlock_bh(&dev_base_lock);
+ }
+}
+
+void hsr_set_operstate(struct net_device *hsr_dev, struct net_device *slave1,
+ struct net_device *slave2)
+{
+ if (!is_admin_up(hsr_dev)) {
+ __hsr_set_operstate(hsr_dev, IF_OPER_DOWN);
+ return;
+ }
+
+ if (is_slave_up(slave1) || is_slave_up(slave2))
+ __hsr_set_operstate(hsr_dev, IF_OPER_UP);
+ else
+ __hsr_set_operstate(hsr_dev, IF_OPER_LOWERLAYERDOWN);
+}
+
+void hsr_set_carrier(struct net_device *hsr_dev, struct net_device *slave1,
+ struct net_device *slave2)
+{
+ if (is_slave_up(slave1) || is_slave_up(slave2))
+ netif_carrier_on(hsr_dev);
+ else
+ netif_carrier_off(hsr_dev);
+}
+
+
+void hsr_check_announce(struct net_device *hsr_dev, int old_operstate)
+{
+ struct hsr_priv *hsr_priv;
+
+ hsr_priv = netdev_priv(hsr_dev);
+
+ if ((hsr_dev->operstate == IF_OPER_UP) && (old_operstate != IF_OPER_UP)) {
+ /* Went up */
+ hsr_priv->announce_count = 0;
+ hsr_priv->announce_timer.expires = jiffies +
+ msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+ add_timer(&hsr_priv->announce_timer);
+ }
+
+ if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
+ /* Went down */
+ del_timer(&hsr_priv->announce_timer);
+}
+
+
+int hsr_get_max_mtu(struct hsr_priv *hsr_priv)
+{
+ int mtu_max;
+
+ if (hsr_priv->slave[0] && hsr_priv->slave[1])
+ mtu_max = min(hsr_priv->slave[0]->mtu, hsr_priv->slave[1]->mtu);
+ else if (hsr_priv->slave[0])
+ mtu_max = hsr_priv->slave[0]->mtu;
+ else if (hsr_priv->slave[1])
+ mtu_max = hsr_priv->slave[1]->mtu;
+ else
+ mtu_max = HSR_TAGLEN;
+
+ return mtu_max - HSR_TAGLEN;
+}
+
+static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct hsr_priv *hsr_priv;
+
+ hsr_priv = netdev_priv(dev);
+
+ if (new_mtu > hsr_get_max_mtu(hsr_priv)) {
+ netdev_info(hsr_priv->dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
+ HSR_TAGLEN);
+ return -EINVAL;
+ }
+
+ dev->mtu = new_mtu;
+
+ return 0;
+}
+
+static int hsr_dev_open(struct net_device *dev)
+{
+ struct hsr_priv *hsr_priv;
+ int i;
+ char *slave_name;
+
+ hsr_priv = netdev_priv(dev);
+
+ for (i = 0; i < HSR_MAX_SLAVE; i++) {
+ if (hsr_priv->slave[i])
+ slave_name = hsr_priv->slave[i]->name;
+ else
+ slave_name = "null";
+
+ if (!is_slave_up(hsr_priv->slave[i]))
+ netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a working HSR network\n",
+ 'A' + i, slave_name);
+ }
+
+ return 0;
+}
+
+static int hsr_dev_close(struct net_device *dev)
+{
+ /* Nothing to do here. We could try to restore the state of the slaves
+ * to what they were before being changed by the hsr master dev's state,
+ * but they might have been changed manually in the mean time too, so
+ * taking them up or down here might be confusing and is probably not a
+ * good idea.
+ */
+ return 0;
+}
+
+
+static void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr_priv)
+{
+ unsigned long irqflags;
+
+ /* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values
+ * between 0001-1001 ("ring identifier", for regular HSR frames),
+ * or 1111 ("HSR management", supervision frames). Unfortunately, the
+ * spec writers forgot to explain what a "ring identifier" is, or
+ * how it is used. So we just set this to 0001 for regular frames,
+ * and 1111 for supervision frames.
+ */
+ set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1);
+
+ /* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet
+ * frame is the content of the frame located between the Length/Type
+ * field and the Frame Check Sequence."
+ *
+ * IEC 62439-3, p 48, specifies the "original LPDU" to include the
+ * original "LT" field (what "LT" means is not explained anywhere as
+ * far as I can see - perhaps "Length/Type"?). So LSDU_size might
+ * equal original length + 2.
+ * Also, the fact that this field is not used anywhere (might be used
+ * by a RedBox connecting HSR and PRP nets?) means I cannot test its
+ * correctness. Instead of guessing, I set this to 0 here, to make any
+ * problems immediately apparent. Anyone using this driver with PRP/HSR
+ * RedBoxes might need to fix this...
+ */
+ set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0);
+
+ spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags);
+ hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr_priv->sequence_nr);
+ hsr_priv->sequence_nr++;
+ spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags);
+
+ hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
+
+ hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
+}
+
+static int slave_xmit(struct sk_buff *skb, struct hsr_priv *hsr_priv,
+ enum hsr_dev_idx dev_idx)
+{
+ struct hsr_ethhdr *hsr_ethhdr;
+
+ hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
+
+ skb->dev = hsr_priv->slave[dev_idx];
+
+ hsr_addr_subst_dest(hsr_priv, &hsr_ethhdr->ethhdr, dev_idx);
+
+ /* Address substitution (IEC62439-3 pp 26, 50): replace mac
+ * address of outgoing frame with that of the outgoing slave's.
+ */
+ memcpy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr, ETH_ALEN);
+
+ return dev_queue_xmit(skb);
+}
+
+
+static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct hsr_priv *hsr_priv;
+ struct hsr_ethhdr *hsr_ethhdr;
+ struct sk_buff *skb2;
+ int res1, res2;
+
+ hsr_priv = netdev_priv(dev);
+ hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
+
+ if ((skb->protocol != htons(ETH_P_PRP)) ||
+ (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) {
+ hsr_fill_tag(hsr_ethhdr, hsr_priv);
+ skb->protocol = htons(ETH_P_PRP);
+ }
+
+ skb2 = pskb_copy(skb, GFP_ATOMIC);
+
+ res1 = NET_XMIT_DROP;
+ if (likely(hsr_priv->slave[HSR_DEV_SLAVE_A]))
+ res1 = slave_xmit(skb, hsr_priv, HSR_DEV_SLAVE_A);
+
+ res2 = NET_XMIT_DROP;
+ if (likely(skb2 && hsr_priv->slave[HSR_DEV_SLAVE_B]))
+ res2 = slave_xmit(skb2, hsr_priv, HSR_DEV_SLAVE_B);
+
+ if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN ||
+ res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) {
+ hsr_priv->dev->stats.tx_packets++;
+ hsr_priv->dev->stats.tx_bytes += skb->len;
+ } else {
+ hsr_priv->dev->stats.tx_dropped++;
+ }
+
+ return NETDEV_TX_OK;
+}
+
+
+static int hsr_header_create(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, const void *daddr,
+ const void *saddr, unsigned int len)
+{
+ int res;
+
+ /* Make room for the HSR tag now. We will fill it in later (in
+ * hsr_dev_xmit)
+ */
+ if (skb_headroom(skb) < HSR_TAGLEN + ETH_HLEN)
+ return -ENOBUFS;
+ skb_push(skb, HSR_TAGLEN);
+
+ /* To allow VLAN/HSR combos we should probably use
+ * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN);
+ * here instead. It would require other changes too, though - e.g.
+ * separate headers for each slave etc...
+ */
+ res = eth_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN);
+ if (res <= 0)
+ return res;
+ skb_reset_mac_header(skb);
+
+ return res + HSR_TAGLEN;
+}
+
+
+static const struct header_ops hsr_header_ops = {
+ .create = hsr_header_create,
+ .parse = eth_header_parse,
+};
+
+
+/* HSR:2010 supervision frames should be padded so that the whole frame,
+ * including headers and FCS, is 64 bytes (without VLAN).
+ */
+static int hsr_pad(int size)
+{
+ const int min_size = ETH_ZLEN - HSR_TAGLEN - ETH_HLEN;
+
+ if (size >= min_size)
+ return size;
+ return min_size;
+}
+
+static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type)
+{
+ struct hsr_priv *hsr_priv;
+ struct sk_buff *skb;
+ int hlen, tlen;
+ struct hsr_sup_tag *hsr_stag;
+ struct hsr_sup_payload *hsr_sp;
+ unsigned long irqflags;
+
+ hlen = LL_RESERVED_SPACE(hsr_dev);
+ tlen = hsr_dev->needed_tailroom;
+ skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
+ GFP_ATOMIC);
+
+ if (skb == NULL)
+ return;
+
+ hsr_priv = netdev_priv(hsr_dev);
+
+ skb_reserve(skb, hlen);
+
+ skb->dev = hsr_dev;
+ skb->protocol = htons(ETH_P_PRP);
+ skb->priority = TC_PRIO_CONTROL;
+
+ if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
+ hsr_priv->sup_multicast_addr,
+ skb->dev->dev_addr, skb->len) < 0)
+ goto out;
+
+ skb_pull(skb, sizeof(struct ethhdr));
+ hsr_stag = (typeof(hsr_stag)) skb->data;
+
+ set_hsr_stag_path(hsr_stag, 0xf);
+ set_hsr_stag_HSR_Ver(hsr_stag, 0);
+
+ spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags);
+ hsr_stag->sequence_nr = htons(hsr_priv->sequence_nr);
+ hsr_priv->sequence_nr++;
+ spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags);
+
+ hsr_stag->HSR_TLV_Type = type;
+ hsr_stag->HSR_TLV_Length = 12;
+
+ skb_push(skb, sizeof(struct ethhdr));
+
+ /* Payload: MacAddressA */
+ hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
+ memcpy(hsr_sp->MacAddressA, hsr_dev->dev_addr, ETH_ALEN);
+
+ dev_queue_xmit(skb);
+ return;
+
+out:
+ kfree_skb(skb);
+}
+
+
+/* Announce (supervision frame) timer function
+ */
+static void hsr_announce(unsigned long data)
+{
+ struct hsr_priv *hsr_priv;
+
+ hsr_priv = (struct hsr_priv *) data;
+
+ if (hsr_priv->announce_count < 3) {
+ send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_ANNOUNCE);
+ hsr_priv->announce_count++;
+ } else {
+ send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_LIFE_CHECK);
+ }
+
+ if (hsr_priv->announce_count < 3)
+ hsr_priv->announce_timer.expires = jiffies +
+ msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
+ else
+ hsr_priv->announce_timer.expires = jiffies +
+ msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
+
+ if (is_admin_up(hsr_priv->dev))
+ add_timer(&hsr_priv->announce_timer);
+}
+
+
+static void restore_slaves(struct net_device *hsr_dev)
+{
+ struct hsr_priv *hsr_priv;
+ int i;
+ int res;
+
+ hsr_priv = netdev_priv(hsr_dev);
+
+ rtnl_lock();
+
+ /* Restore promiscuity */
+ for (i = 0; i < HSR_MAX_SLAVE; i++) {
+ if (!hsr_priv->slave[i])
+ continue;
+ res = dev_set_promiscuity(hsr_priv->slave[i], -1);
+ if (res)
+ netdev_info(hsr_dev,
+ "Cannot restore slave promiscuity (%s, %d)\n",
+ hsr_priv->slave[i]->name, res);
+ }
+
+ rtnl_unlock();
+}
+
+static void reclaim_hsr_dev(struct rcu_head *rh)
+{
+ struct hsr_priv *hsr_priv;
+
+ hsr_priv = container_of(rh, struct hsr_priv, rcu_head);
+ free_netdev(hsr_priv->dev);
+}
+
+
+/* According to comments in the declaration of struct net_device, this function
+ * is "Called from unregister, can be used to call free_netdev". Ok then...
+ */
+static void hsr_dev_destroy(struct net_device *hsr_dev)
+{
+ struct hsr_priv *hsr_priv;
+
+ hsr_priv = netdev_priv(hsr_dev);
+
+ del_timer(&hsr_priv->announce_timer);
+ unregister_hsr_master(hsr_priv); /* calls list_del_rcu on hsr_priv */
+ restore_slaves(hsr_dev);
+ call_rcu(&hsr_priv->rcu_head, reclaim_hsr_dev); /* reclaim hsr_priv */
+}
+
+static const struct net_device_ops hsr_device_ops = {
+ .ndo_change_mtu = hsr_dev_change_mtu,
+ .ndo_open = hsr_dev_open,
+ .ndo_stop = hsr_dev_close,
+ .ndo_start_xmit = hsr_dev_xmit,
+};
+
+
+void hsr_dev_setup(struct net_device *dev)
+{
+ random_ether_addr(dev->dev_addr);
+
+ ether_setup(dev);
+ dev->header_ops = &hsr_header_ops;
+ dev->netdev_ops = &hsr_device_ops;
+ dev->tx_queue_len = 0;
+
+ dev->destructor = hsr_dev_destroy;
+}
+
+
+/* Return true if dev is a HSR master; return false otherwise.
+ */
+bool is_hsr_master(struct net_device *dev)
+{
+ return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
+}
+
+static int check_slave_ok(struct net_device *dev)
+{
+ /* Don't allow HSR on non-ethernet like devices */
+ if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
+ (dev->addr_len != ETH_ALEN)) {
+ netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
+ return -EINVAL;
+ }
+
+ /* Don't allow enslaving hsr devices */
+ if (is_hsr_master(dev)) {
+ netdev_info(dev, "Cannot create trees of HSR devices.\n");
+ return -EINVAL;
+ }
+
+ if (is_hsr_slave(dev)) {
+ netdev_info(dev, "This device is already a HSR slave.\n");
+ return -EINVAL;
+ }
+
+ if (dev->priv_flags & IFF_802_1Q_VLAN) {
+ netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
+ return -EINVAL;
+ }
+
+ /* HSR over bonded devices has not been tested, but I'm not sure it
+ * won't work...
+ */
+
+ return 0;
+}
+
+
+/* Default multicast address for HSR Supervision frames */
+static const unsigned char def_multicast_addr[ETH_ALEN] = {
+ 0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
+};
+
+int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
+ unsigned char multicast_spec)
+{
+ struct hsr_priv *hsr_priv;
+ int i;
+ int res;
+
+ hsr_priv = netdev_priv(hsr_dev);
+ hsr_priv->dev = hsr_dev;
+ INIT_LIST_HEAD(&hsr_priv->node_db);
+ INIT_LIST_HEAD(&hsr_priv->self_node_db);
+ for (i = 0; i < HSR_MAX_SLAVE; i++)
+ hsr_priv->slave[i] = slave[i];
+
+ spin_lock_init(&hsr_priv->seqnr_lock);
+ /* Overflow soon to find bugs easier: */
+ hsr_priv->sequence_nr = USHRT_MAX - 1024;
+
+ init_timer(&hsr_priv->announce_timer);
+ hsr_priv->announce_timer.function = hsr_announce;
+ hsr_priv->announce_timer.data = (unsigned long) hsr_priv;
+
+ memcpy(hsr_priv->sup_multicast_addr, def_multicast_addr, ETH_ALEN);
+ hsr_priv->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
+
+/* FIXME: should I modify the value of these?
+ *
+ * - hsr_dev->flags - i.e.
+ * IFF_MASTER/SLAVE?
+ * - hsr_dev->priv_flags - i.e.
+ * IFF_EBRIDGE?
+ * IFF_TX_SKB_SHARING?
+ * IFF_HSR_MASTER/SLAVE?
+ */
+
+ for (i = 0; i < HSR_MAX_SLAVE; i++) {
+ res = check_slave_ok(slave[i]);
+ if (res)
+ return res;
+ }
+
+ hsr_dev->features = slave[0]->features & slave[1]->features;
+ /* Prevent recursive tx locking */
+ hsr_dev->features |= NETIF_F_LLTX;
+ /* VLAN on top of HSR needs testing and probably some work on
+ * hsr_header_create() etc.
+ */
+ hsr_dev->features |= NETIF_F_VLAN_CHALLENGED;
+
+ /* Set hsr_dev's MAC address to that of mac_slave1 */
+ memcpy(hsr_dev->dev_addr, hsr_priv->slave[0]->dev_addr, ETH_ALEN);
+
+ /* Set required header length */
+ for (i = 0; i < HSR_MAX_SLAVE; i++) {
+ if (slave[i]->hard_header_len + HSR_TAGLEN >
+ hsr_dev->hard_header_len)
+ hsr_dev->hard_header_len =
+ slave[i]->hard_header_len + HSR_TAGLEN;
+ }
+
+ /* MTU */
+ for (i = 0; i < HSR_MAX_SLAVE; i++)
+ if (slave[i]->mtu - HSR_TAGLEN < hsr_dev->mtu)
+ hsr_dev->mtu = slave[i]->mtu - HSR_TAGLEN;
+
+ /* Make sure the 1st call to netif_carrier_on() gets through */
+ netif_carrier_off(hsr_dev);
+
+ /* Promiscuity */
+ for (i = 0; i < HSR_MAX_SLAVE; i++) {
+ res = dev_set_promiscuity(slave[i], 1);
+ if (res) {
+ netdev_info(hsr_dev, "Cannot set slave promiscuity (%s, %d)\n",
+ slave[i]->name, res);
+ goto fail;
+ }
+ }
+
+ /* Make sure we recognize frames from ourselves in hsr_rcv() */
+ res = hsr_create_self_node(&hsr_priv->self_node_db,
+ hsr_dev->dev_addr,
+ hsr_priv->slave[1]->dev_addr);
+ if (res < 0)
+ goto fail;
+
+ res = register_netdevice(hsr_dev);
+ if (res)
+ goto fail;
+
+ register_hsr_master(hsr_priv);
+
+ return 0;
+
+fail:
+ restore_slaves(hsr_dev);
+ return res;
+}