*
* Author(s):
* 2011-2014 Arvid Brodin, arvid.brodin@alten.se
- *
- * In addition to routines for registering and unregistering HSR support, this
- * file also contains the receive routine that handles all incoming frames with
- * Ethertype (protocol) ETH_P_PRP (HSRv0), and network device event handling.
*/
#include <linux/netdevice.h>
return false;
}
-
/* If dev is a HSR slave device, return the virtual master device. Return NULL
* otherwise.
*/
-static struct hsr_priv *get_hsr_master(struct net_device *dev)
+struct hsr_priv *get_hsr_master(struct net_device *dev)
{
struct hsr_priv *hsr;
return NULL;
}
-
/* If dev is a HSR slave device, return the other slave device. Return NULL
* otherwise.
*/
-static struct net_device *get_other_slave(struct hsr_priv *hsr,
- struct net_device *dev)
+struct net_device *get_other_slave(struct hsr_priv *hsr,
+ struct net_device *dev)
{
if (dev == hsr->slave[0])
return hsr->slave[1];
}
-static struct sk_buff *hsr_pull_tag(struct sk_buff *skb)
-{
- struct hsr_tag *hsr_tag;
- struct sk_buff *skb2;
-
- skb2 = skb_share_check(skb, GFP_ATOMIC);
- if (unlikely(!skb2))
- goto err_free;
- skb = skb2;
-
- if (unlikely(!pskb_may_pull(skb, HSR_HLEN)))
- goto err_free;
-
- hsr_tag = (struct hsr_tag *) skb->data;
- skb->protocol = hsr_tag->encap_proto;
- skb_pull(skb, HSR_HLEN);
-
- return skb;
-
-err_free:
- kfree_skb(skb);
- return NULL;
-}
-
-
-/* The uses I can see for these HSR supervision frames are:
- * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
- * 22") to reset any sequence_nr counters belonging to that node. Useful if
- * the other node's counter has been reset for some reason.
- * --
- * Or not - resetting the counter and bridging the frame would create a
- * loop, unfortunately.
- *
- * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
- * frame is received from a particular node, we know something is wrong.
- * We just register these (as with normal frames) and throw them away.
- *
- * 3) Allow different MAC addresses for the two slave interfaces, using the
- * MacAddressA field.
- */
-static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
-{
- struct hsr_sup_tag *hsr_stag;
-
- if (!ether_addr_equal(eth_hdr(skb)->h_dest,
- hsr->sup_multicast_addr))
- return false;
-
- hsr_stag = (struct hsr_sup_tag *) skb->data;
- if (get_hsr_stag_path(hsr_stag) != 0x0f)
- return false;
- if ((hsr_stag->HSR_TLV_Type != HSR_TLV_ANNOUNCE) &&
- (hsr_stag->HSR_TLV_Type != HSR_TLV_LIFE_CHECK))
- return false;
- if (hsr_stag->HSR_TLV_Length != 12)
- return false;
-
- return true;
-}
-
-
-/* Implementation somewhat according to IEC-62439-3, p. 43
- */
-static int hsr_rcv(struct sk_buff *skb, struct net_device *dev,
- struct packet_type *pt, struct net_device *orig_dev)
-{
- struct hsr_priv *hsr;
- struct net_device *other_slave;
- struct hsr_node *node;
- bool deliver_to_self;
- struct sk_buff *skb_deliver;
- enum hsr_dev_idx dev_in_idx, dev_other_idx;
- bool dup_out;
- int ret;
-
- hsr = get_hsr_master(dev);
-
- if (!hsr) {
- /* Non-HSR-slave device 'dev' is connected to a HSR network */
- kfree_skb(skb);
- dev->stats.rx_errors++;
- return NET_RX_SUCCESS;
- }
-
- if (dev == hsr->slave[0]) {
- dev_in_idx = HSR_DEV_SLAVE_A;
- dev_other_idx = HSR_DEV_SLAVE_B;
- } else {
- dev_in_idx = HSR_DEV_SLAVE_B;
- dev_other_idx = HSR_DEV_SLAVE_A;
- }
-
- node = hsr_find_node(&hsr->self_node_db, skb);
- if (node) {
- /* Always kill frames sent by ourselves */
- kfree_skb(skb);
- return NET_RX_SUCCESS;
- }
-
- /* Is this frame a candidate for local reception? */
- deliver_to_self = false;
- if ((skb->pkt_type == PACKET_HOST) ||
- (skb->pkt_type == PACKET_MULTICAST) ||
- (skb->pkt_type == PACKET_BROADCAST))
- deliver_to_self = true;
- else if (ether_addr_equal(eth_hdr(skb)->h_dest,
- hsr->dev->dev_addr)) {
- skb->pkt_type = PACKET_HOST;
- deliver_to_self = true;
- }
-
-
- rcu_read_lock(); /* node_db */
- node = hsr_find_node(&hsr->node_db, skb);
-
- if (is_supervision_frame(hsr, skb)) {
- skb_pull(skb, sizeof(struct hsr_sup_tag));
- node = hsr_merge_node(hsr, node, skb, dev_in_idx);
- if (!node) {
- rcu_read_unlock(); /* node_db */
- kfree_skb(skb);
- hsr->dev->stats.rx_dropped++;
- return NET_RX_DROP;
- }
- skb_push(skb, sizeof(struct hsr_sup_tag));
- deliver_to_self = false;
- }
-
- if (!node) {
- /* Source node unknown; this might be a HSR frame from
- * another net (different multicast address). Ignore it.
- */
- rcu_read_unlock(); /* node_db */
- kfree_skb(skb);
- return NET_RX_SUCCESS;
- }
-
- /* Register ALL incoming frames as outgoing through the other interface.
- * This allows us to register frames as incoming only if they are valid
- * for the receiving interface, without using a specific counter for
- * incoming frames.
- */
- dup_out = hsr_register_frame_out(node, dev_other_idx, skb);
- if (!dup_out)
- hsr_register_frame_in(node, dev_in_idx);
-
- /* Forward this frame? */
- if (!dup_out && (skb->pkt_type != PACKET_HOST))
- other_slave = get_other_slave(hsr, dev);
- else
- other_slave = NULL;
-
- if (hsr_register_frame_out(node, HSR_DEV_MASTER, skb))
- deliver_to_self = false;
-
- rcu_read_unlock(); /* node_db */
-
- if (!deliver_to_self && !other_slave) {
- kfree_skb(skb);
- /* Circulated frame; silently remove it. */
- return NET_RX_SUCCESS;
- }
-
- skb_deliver = skb;
- if (deliver_to_self && other_slave) {
- /* skb_clone() is not enough since we will strip the hsr tag
- * and do address substitution below
- */
- skb_deliver = pskb_copy(skb, GFP_ATOMIC);
- if (!skb_deliver) {
- deliver_to_self = false;
- hsr->dev->stats.rx_dropped++;
- }
- }
-
- if (deliver_to_self) {
- bool multicast_frame;
-
- skb_deliver = hsr_pull_tag(skb_deliver);
- if (!skb_deliver) {
- hsr->dev->stats.rx_dropped++;
- goto forward;
- }
-#if !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
- /* Move everything in the header that is after the HSR tag,
- * to work around alignment problems caused by the 6-byte HSR
- * tag. In practice, this removes/overwrites the HSR tag in
- * the header and restores a "standard" packet.
- */
- memmove(skb_deliver->data - HSR_HLEN, skb_deliver->data,
- skb_headlen(skb_deliver));
-
- /* Adjust skb members so they correspond with the move above.
- * This cannot possibly underflow skb->data since hsr_pull_tag()
- * above succeeded.
- * At this point in the protocol stack, the transport and
- * network headers have not been set yet, and we haven't touched
- * the mac header nor the head. So we only need to adjust data
- * and tail:
- */
- skb_deliver->data -= HSR_HLEN;
- skb_deliver->tail -= HSR_HLEN;
-#endif
- skb_deliver->dev = hsr->dev;
- hsr_addr_subst_source(hsr, skb_deliver);
- multicast_frame = (skb_deliver->pkt_type == PACKET_MULTICAST);
- ret = netif_rx(skb_deliver);
- if (ret == NET_RX_DROP) {
- hsr->dev->stats.rx_dropped++;
- } else {
- hsr->dev->stats.rx_packets++;
- hsr->dev->stats.rx_bytes += skb->len;
- if (multicast_frame)
- hsr->dev->stats.multicast++;
- }
- }
-
-forward:
- if (other_slave) {
- skb_push(skb, ETH_HLEN);
- skb->dev = other_slave;
- dev_queue_xmit(skb);
- }
-
- return NET_RX_SUCCESS;
-}
-
-
-static struct packet_type hsr_pt __read_mostly = {
- .type = htons(ETH_P_PRP),
- .func = hsr_rcv,
-};
-
static struct notifier_block hsr_nb = {
.notifier_call = hsr_netdev_notify, /* Slave event notifications */
};
BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
- dev_add_pack(&hsr_pt);
-
init_timer(&prune_timer);
prune_timer.function = prune_nodes_all;
prune_timer.data = 0;
unregister_netdevice_notifier(&hsr_nb);
del_timer_sync(&prune_timer);
hsr_netlink_exit();
- dev_remove_pack(&hsr_pt);
}
module_init(hsr_init);
projects / cascardo / linux.git / blobdiff