dsa: add support for Trailer tagging format
Lennert Buytenhek [Tue, 7 Oct 2008 13:46:07 +0000 (13:46 +0000)]
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 <buytenh@marvell.com>
Tested-by: Byron Bradley <byron.bbradley@gmail.com>
Tested-by: Tim Ellis <tim.ellis@mac.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_ether.h
include/linux/netdevice.h
include/net/dsa.h
net/dsa/Kconfig
net/dsa/Makefile
net/dsa/dsa.c
net/dsa/dsa_priv.h
net/dsa/slave.c
net/dsa/tag_trailer.c [new file with mode: 0644]
net/ethernet/eth.c

index 32b9dcd..a0099e9 100644 (file)
 #define ETH_P_HDLC     0x0019          /* HDLC frames                  */
 #define ETH_P_ARCNET   0x001A          /* 1A for ArcNet :-)            */
 #define ETH_P_DSA      0x001B          /* Distributed Switch Arch.     */
+#define ETH_P_TRAILER  0x001C          /* Trailer switch tagging       */
 #define ETH_P_PHONET   0x00F5          /* Nokia Phonet frames          */
 
 /*
index 97f0c64..d3ea3de 100644 (file)
@@ -812,6 +812,16 @@ static inline bool netdev_uses_dsa_tags(struct net_device *dev)
        return 0;
 }
 
+static inline bool netdev_uses_trailer_tags(struct net_device *dev)
+{
+#ifdef CONFIG_NET_DSA_TAG_TRAILER
+       if (dev->dsa_ptr != NULL)
+               return dsa_uses_trailer_tags(dev->dsa_ptr);
+#endif
+
+       return 0;
+}
+
 /**
  *     netdev_priv - access network device private data
  *     @dev: network device
index 72e509b..52e97bf 100644 (file)
@@ -31,6 +31,7 @@ struct dsa_platform_data {
 };
 
 extern bool dsa_uses_dsa_tags(void *dsa_ptr);
+extern bool dsa_uses_trailer_tags(void *dsa_ptr);
 
 
 #endif
index 79bcd76..505aa14 100644 (file)
@@ -18,6 +18,10 @@ config NET_DSA_TAG_EDSA
        bool
        default n
 
+config NET_DSA_TAG_TRAILER
+       bool
+       default n
+
 
 # switch drivers
 config NET_DSA_MV88E6XXX
index 7fb6f85..63d3c44 100644 (file)
@@ -1,6 +1,7 @@
 # tagging formats
 obj-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
 obj-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
+obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
 
 # switch drivers
 obj-$(CONFIG_NET_DSA_MV88E6XXX) += mv88e6xxx.o
index f8c5492..33e9946 100644 (file)
@@ -217,6 +217,13 @@ bool dsa_uses_dsa_tags(void *dsa_ptr)
        return !!(ds->tag_protocol == htons(ETH_P_DSA));
 }
 
+bool dsa_uses_trailer_tags(void *dsa_ptr)
+{
+       struct dsa_switch *ds = dsa_ptr;
+
+       return !!(ds->tag_protocol == htons(ETH_P_TRAILER));
+}
+
 
 /* link polling *************************************************************/
 static void dsa_link_poll_work(struct work_struct *ugly)
index 2f1d68c..7063378 100644 (file)
@@ -109,5 +109,8 @@ int dsa_xmit(struct sk_buff *skb, struct net_device *dev);
 /* tag_edsa.c */
 int edsa_xmit(struct sk_buff *skb, struct net_device *dev);
 
+/* tag_trailer.c */
+int trailer_xmit(struct sk_buff *skb, struct net_device *dev);
+
 
 #endif
index 8f8868d..3761688 100644 (file)
@@ -249,6 +249,11 @@ dsa_slave_create(struct dsa_switch *ds, struct device *parent,
                slave_dev->hard_start_xmit = edsa_xmit;
                break;
 #endif
+#ifdef CONFIG_NET_DSA_TAG_TRAILER
+       case htons(ETH_P_TRAILER):
+               slave_dev->hard_start_xmit = trailer_xmit;
+               break;
+#endif
        default:
                BUG();
        }
diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
new file mode 100644 (file)
index 0000000..d311776
--- /dev/null
@@ -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 <linux/etherdevice.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#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);
index dae47e7..b9d85af 100644 (file)
@@ -193,6 +193,8 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
         */
        if (netdev_uses_dsa_tags(dev))
                return htons(ETH_P_DSA);
+       if (netdev_uses_trailer_tags(dev))
+               return htons(ETH_P_TRAILER);
 
        if (ntohs(eth->h_proto) >= 1536)
                return eth->h_proto;