Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 214 insertions, 0 deletions

diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c
new file mode 100644
index 0000000..9f4ce55
--- /dev/null
+++ b/net/dsa/tag_edsa.c
@@ -0,0 +1,214 @@
+/*
+ * net/dsa/tag_edsa.c - Ethertype DSA tagging
+ * Copyright (c) 2008 Marvell Semiconductor
+ *
+ * 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.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include "dsa_priv.h"
+
+#define DSA_HLEN	4
+#define EDSA_HLEN	8
+
+int edsa_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct dsa_slave_priv *p = netdev_priv(dev);
+	u8 *edsa_header;
+
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += skb->len;
+
+	/*
+	 * Convert the outermost 802.1q tag to a DSA tag and prepend
+	 * a DSA ethertype field is the packet is tagged, or insert
+	 * a DSA ethertype plus DSA tag between the addresses and the
+	 * current ethertype field if the packet is untagged.
+	 */
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		if (skb_cow_head(skb, DSA_HLEN) < 0)
+			goto out_free;
+		skb_push(skb, DSA_HLEN);
+
+		memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);
+
+		/*
+		 * Construct tagged FROM_CPU DSA tag from 802.1q tag.
+		 */
+		edsa_header = skb->data + 2 * ETH_ALEN;
+		edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
+		edsa_header[1] = ETH_P_EDSA & 0xff;
+		edsa_header[2] = 0x00;
+		edsa_header[3] = 0x00;
+		edsa_header[4] = 0x60;
+		edsa_header[5] = p->port << 3;
+
+		/*
+		 * Move CFI field from byte 6 to byte 5.
+		 */
+		if (edsa_header[6] & 0x10) {
+			edsa_header[5] |= 0x01;
+			edsa_header[6] &= ~0x10;
+		}
+	} else {
+		if (skb_cow_head(skb, EDSA_HLEN) < 0)
+			goto out_free;
+		skb_push(skb, EDSA_HLEN);
+
+		memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN);
+
+		/*
+		 * Construct untagged FROM_CPU DSA tag.
+		 */
+		edsa_header = skb->data + 2 * ETH_ALEN;
+		edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
+		edsa_header[1] = ETH_P_EDSA & 0xff;
+		edsa_header[2] = 0x00;
+		edsa_header[3] = 0x00;
+		edsa_header[4] = 0x40;
+		edsa_header[5] = p->port << 3;
+		edsa_header[6] = 0x00;
+		edsa_header[7] = 0x00;
+	}
+
+	skb->protocol = htons(ETH_P_EDSA);
+
+	skb->dev = p->parent->master_netdev;
+	dev_queue_xmit(skb);
+
+	return NETDEV_TX_OK;
+
+out_free:
+	kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static int edsa_rcv(struct sk_buff *skb, struct net_device *dev,
+		    struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct dsa_switch *ds = dev->dsa_ptr;
+	u8 *edsa_header;
+	int source_port;
+
+	if (unlikely(ds == NULL))
+		goto out_drop;
+
+	skb = skb_unshare(skb, GFP_ATOMIC);
+	if (skb == NULL)
+		goto out;
+
+	if (unlikely(!pskb_may_pull(skb, EDSA_HLEN)))
+		goto out_drop;
+
+	/*
+	 * Skip the two null bytes after the ethertype.
+	 */
+	edsa_header = skb->data + 2;
+
+	/*
+	 * Check that frame type is either TO_CPU or FORWARD, and
+	 * that the source device is zero.
+	 */
+	if ((edsa_header[0] & 0xdf) != 0x00 && (edsa_header[0] & 0xdf) != 0xc0)
+		goto out_drop;
+
+	/*
+	 * Check that the source port is a registered DSA port.
+	 */
+	source_port = (edsa_header[1] >> 3) & 0x1f;
+	if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
+		goto out_drop;
+
+	/*
+	 * If the 'tagged' bit is set, convert the DSA tag to a 802.1q
+	 * tag and delete the ethertype part.  If the 'tagged' bit is
+	 * clear, delete the ethertype and the DSA tag parts.
+	 */
+	if (edsa_header[0] & 0x20) {
+		u8 new_header[4];
+
+		/*
+		 * Insert 802.1q ethertype and copy the VLAN-related
+		 * fields, but clear the bit that will hold CFI (since
+		 * DSA uses that bit location for another purpose).
+		 */
+		new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
+		new_header[1] = ETH_P_8021Q & 0xff;
+		new_header[2] = edsa_header[2] & ~0x10;
+		new_header[3] = edsa_header[3];
+
+		/*
+		 * Move CFI bit from its place in the DSA header to
+		 * its 802.1q-designated place.
+		 */
+		if (edsa_header[1] & 0x01)
+			new_header[2] |= 0x10;
+
+		skb_pull_rcsum(skb, DSA_HLEN);
+
+		/*
+		 * Update packet checksum if skb is CHECKSUM_COMPLETE.
+		 */
+		if (skb->ip_summed == CHECKSUM_COMPLETE) {
+			__wsum c = skb->csum;
+			c = csum_add(c, csum_partial(new_header + 2, 2, 0));
+			c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0));
+			skb->csum = c;
+		}
+
+		memcpy(edsa_header, new_header, DSA_HLEN);
+
+		memmove(skb->data - ETH_HLEN,
+			skb->data - ETH_HLEN - DSA_HLEN,
+			2 * ETH_ALEN);
+	} else {
+		/*
+		 * Remove DSA tag and update checksum.
+		 */
+		skb_pull_rcsum(skb, EDSA_HLEN);
+		memmove(skb->data - ETH_HLEN,
+			skb->data - ETH_HLEN - EDSA_HLEN,
+			2 * ETH_ALEN);
+	}
+
+	skb->dev = ds->ports[source_port];
+	skb_push(skb, ETH_HLEN);
+	skb->pkt_type = PACKET_HOST;
+	skb->protocol = eth_type_trans(skb, skb->dev);
+
+	skb->dev->last_rx = jiffies;
+	skb->dev->stats.rx_packets++;
+	skb->dev->stats.rx_bytes += skb->len;
+
+	netif_receive_skb(skb);
+
+	return 0;
+
+out_drop:
+	kfree_skb(skb);
+out:
+	return 0;
+}
+
+static struct packet_type edsa_packet_type = {
+	.type	= __constant_htons(ETH_P_EDSA),
+	.func	= edsa_rcv,
+};
+
+static int __init edsa_init_module(void)
+{
+	dev_add_pack(&edsa_packet_type);
+	return 0;
+}
+module_init(edsa_init_module);
+
+static void __exit edsa_cleanup_module(void)
+{
+	dev_remove_pack(&edsa_packet_type);
+}
+module_exit(edsa_cleanup_module);