diff options
Diffstat (limited to 'net/dsa/tag_edsa.c')
| -rw-r--r-- | net/dsa/tag_edsa.c | 213 |
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); |