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authorArvid Brodin <arvid.brodin@alten.se>2014-07-04 23:35:24 +0200
committerDavid S. Miller <davem@davemloft.net>2014-07-08 11:35:30 -0700
commit81ba6afd6e6443d2bf4bf40f16df1f1f91c603f8 (patch)
tree62220e2dd7d59cb889a0b7859475f2a445450ab5 /net/hsr/hsr_slave.c
parent70ebe4a47185db15f3c55be9611a1a971237870b (diff)
net/hsr: Switch from dev_add_pack() to netdev_rx_handler_register()
Also move the frame receive handler to hsr_slave.c. Signed-off-by: Arvid Brodin <arvid.brodin@alten.se> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/hsr/hsr_slave.c')
-rw-r--r--net/hsr/hsr_slave.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
new file mode 100644
index 000000000000..702814631ee1
--- /dev/null
+++ b/net/hsr/hsr_slave.c
@@ -0,0 +1,243 @@
+/* Copyright 2011-2014 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):
+ * 2011-2014 Arvid Brodin, arvid.brodin@alten.se
+ */
+
+#include "hsr_slave.h"
+#include <linux/etherdevice.h>
+#include "hsr_main.h"
+#include "hsr_framereg.h"
+
+
+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
+ */
+rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
+{
+ struct sk_buff *skb = *pskb;
+ struct net_device *dev = skb->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;
+
+ if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
+ return RX_HANDLER_PASS;
+
+ hsr = get_hsr_master(dev);
+ if (!hsr) {
+ WARN_ON_ONCE(1);
+ return RX_HANDLER_PASS;
+ }
+
+ 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 RX_HANDLER_CONSUMED;
+ }
+
+ /* 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 RX_HANDLER_CONSUMED;
+ }
+ 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 RX_HANDLER_CONSUMED;
+ }
+
+ /* 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 RX_HANDLER_CONSUMED;
+ }
+
+ 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 RX_HANDLER_CONSUMED;
+}