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Diffstat (limited to 'net/dsa/tag_edsa.c')
-rw-r--r--net/dsa/tag_edsa.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c
new file mode 100644
index 00000000000..f985ea99384
--- /dev/null
+++ b/net/dsa/tag_edsa.c
@@ -0,0 +1,213 @@
+/*
+ * 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->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);