From 396138f03f4521c55ecc3a5dd75d4c56e6323244 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Tue, 7 Oct 2008 13:46:07 +0000 Subject: dsa: add support for Trailer tagging format This adds support for the Trailer switch tagging format. This is another tagging that doesn't explicitly mark tagged packets with a distinct ethertype, so that we need to add a similar hack in the receive path as for the Original DSA tagging format. Signed-off-by: Lennert Buytenhek Tested-by: Byron Bradley Tested-by: Tim Ellis Signed-off-by: David S. Miller --- net/dsa/tag_trailer.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 net/dsa/tag_trailer.c (limited to 'net/dsa/tag_trailer.c') diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c new file mode 100644 index 00000000000..d3117764b2c --- /dev/null +++ b/net/dsa/tag_trailer.c @@ -0,0 +1,130 @@ +/* + * net/dsa/tag_trailer.c - Trailer tag format handling + * 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 +#include +#include +#include "dsa_priv.h" + +int trailer_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct dsa_slave_priv *p = netdev_priv(dev); + struct sk_buff *nskb; + int padlen; + u8 *trailer; + + dev->stats.tx_packets++; + dev->stats.tx_bytes += skb->len; + + /* + * We have to make sure that the trailer ends up as the very + * last 4 bytes of the packet. This means that we have to pad + * the packet to the minimum ethernet frame size, if necessary, + * before adding the trailer. + */ + padlen = 0; + if (skb->len < 60) + padlen = 60 - skb->len; + + nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC); + if (nskb == NULL) { + kfree_skb(skb); + return NETDEV_TX_OK; + } + skb_reserve(nskb, NET_IP_ALIGN); + + skb_reset_mac_header(nskb); + skb_set_network_header(nskb, skb_network_header(skb) - skb->head); + skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head); + skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len)); + kfree_skb(skb); + + if (padlen) { + u8 *pad = skb_put(nskb, padlen); + memset(pad, 0, padlen); + } + + trailer = skb_put(nskb, 4); + trailer[0] = 0x80; + trailer[1] = 1 << p->port; + trailer[2] = 0x10; + trailer[3] = 0x00; + + nskb->protocol = htons(ETH_P_TRAILER); + + nskb->dev = p->parent->master_netdev; + dev_queue_xmit(nskb); + + return NETDEV_TX_OK; +} + +static int trailer_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 *trailer; + int source_port; + + if (unlikely(ds == NULL)) + goto out_drop; + + skb = skb_unshare(skb, GFP_ATOMIC); + if (skb == NULL) + goto out; + + if (skb_linearize(skb)) + goto out_drop; + + trailer = skb_tail_pointer(skb) - 4; + if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 || + (trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00) + goto out_drop; + + source_port = trailer[1] & 7; + if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL) + goto out_drop; + + pskb_trim_rcsum(skb, skb->len - 4); + + 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 trailer_packet_type = { + .type = __constant_htons(ETH_P_TRAILER), + .func = trailer_rcv, +}; + +static int __init trailer_init_module(void) +{ + dev_add_pack(&trailer_packet_type); + return 0; +} +module_init(trailer_init_module); + +static void __exit trailer_cleanup_module(void) +{ + dev_remove_pack(&trailer_packet_type); +} +module_exit(trailer_cleanup_module); -- cgit v1.2.3