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 <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>

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 <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>
Lennert Buytenhek · David S. Miller
1 parent 2e5f032095
Showing 10 changed files with 164 additions and 0 deletions Side-by-side Diff
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
net/ethernet/eth.c
@@ -102,6 +102,7 @@
 #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          */
  
 /*
@@ -812,6 +812,16 @@
 	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
@@ -31,6 +31,7 @@
 };
  
 extern bool dsa_uses_dsa_tags(void *dsa_ptr);
+extern bool dsa_uses_trailer_tags(void *dsa_ptr);
  
  
 #endif
@@ -18,6 +18,10 @@
 	bool
 	default n
  
+config NET_DSA_TAG_TRAILER
+	bool
+	default n
+
  
 # switch drivers
 config NET_DSA_MV88E6XXX
 # 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
@@ -217,6 +217,13 @@
 	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)
@@ -109,6 +109,9 @@
 /* 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
@@ -249,6 +249,11 @@
 		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();
 	}
+/*
+ * 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);
@@ -193,6 +193,8 @@
 	 */
 	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;
...	...	@@ -102,6 +102,7 @@
102	102	#define ETH_P_HDLC 0x0019 /* HDLC frames */
103	103	#define ETH_P_ARCNET 0x001A /* 1A for ArcNet :-) */
104	104	#define ETH_P_DSA 0x001B /* Distributed Switch Arch. */
	105	+#define ETH_P_TRAILER 0x001C /* Trailer switch tagging */
105	106	#define ETH_P_PHONET 0x00F5 /* Nokia Phonet frames */
106	107
107	108	/*
...	...	@@ -812,6 +812,16 @@
812	812	return 0;
813	813	}
814	814
	815	+static inline bool netdev_uses_trailer_tags(struct net_device *dev)
	816	+{
	817	+#ifdef CONFIG_NET_DSA_TAG_TRAILER
	818	+ if (dev->dsa_ptr != NULL)
	819	+ return dsa_uses_trailer_tags(dev->dsa_ptr);
	820	+#endif
	821	+
	822	+ return 0;
	823	+}
	824	+
815	825	/**
816	826	* netdev_priv - access network device private data
817	827	* @dev: network device
...	...	@@ -31,6 +31,7 @@
31	31	};
32	32
33	33	extern bool dsa_uses_dsa_tags(void *dsa_ptr);
	34	+extern bool dsa_uses_trailer_tags(void *dsa_ptr);
34	35
35	36
36	37	#endif
...	...	@@ -18,6 +18,10 @@
18	18	bool
19	19	default n
20	20
	21	+config NET_DSA_TAG_TRAILER
	22	+ bool
	23	+ default n
	24	+
21	25
22	26	# switch drivers
23	27	config NET_DSA_MV88E6XXX
1	1	# tagging formats
2	2	obj-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
3	3	obj-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
	4	+obj-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
4	5
5	6	# switch drivers
6	7	obj-$(CONFIG_NET_DSA_MV88E6XXX) += mv88e6xxx.o
...	...	@@ -217,6 +217,13 @@
217	217	return !!(ds->tag_protocol == htons(ETH_P_DSA));
218	218	}
219	219
	220	+bool dsa_uses_trailer_tags(void *dsa_ptr)
	221	+{
	222	+ struct dsa_switch *ds = dsa_ptr;
	223	+
	224	+ return !!(ds->tag_protocol == htons(ETH_P_TRAILER));
	225	+}
	226	+
220	227
221	228	/* link polling *************************************************************/
222	229	static void dsa_link_poll_work(struct work_struct *ugly)
...	...	@@ -109,6 +109,9 @@
109	109	/* tag_edsa.c */
110	110	int edsa_xmit(struct sk_buff skb, struct net_device dev);
111	111
	112	+/* tag_trailer.c */
	113	+int trailer_xmit(struct sk_buff skb, struct net_device dev);
	114	+
112	115
113	116	#endif
...	...	@@ -249,6 +249,11 @@
249	249	slave_dev->hard_start_xmit = edsa_xmit;
250	250	break;
251	251	#endif
	252	+#ifdef CONFIG_NET_DSA_TAG_TRAILER
	253	+ case htons(ETH_P_TRAILER):
	254	+ slave_dev->hard_start_xmit = trailer_xmit;
	255	+ break;
	256	+#endif
252	257	default:
253	258	BUG();
254	259	}
	1	+/*
	2	+ * net/dsa/tag_trailer.c - Trailer tag format handling
	3	+ * Copyright (c) 2008 Marvell Semiconductor
	4	+ *
	5	+ * This program is free software; you can redistribute it and/or modify
	6	+ * it under the terms of the GNU General Public License as published by
	7	+ * the Free Software Foundation; either version 2 of the License, or
	8	+ * (at your option) any later version.
	9	+ */
	10	+
	11	+#include <linux/etherdevice.h>
	12	+#include <linux/list.h>
	13	+#include <linux/netdevice.h>
	14	+#include "dsa_priv.h"
	15	+
	16	+int trailer_xmit(struct sk_buff skb, struct net_device dev)
	17	+{
	18	+ struct dsa_slave_priv *p = netdev_priv(dev);
	19	+ struct sk_buff *nskb;
	20	+ int padlen;
	21	+ u8 *trailer;
	22	+
	23	+ dev->stats.tx_packets++;
	24	+ dev->stats.tx_bytes += skb->len;
	25	+
	26	+ /*
	27	+ * We have to make sure that the trailer ends up as the very
	28	+ * last 4 bytes of the packet. This means that we have to pad
	29	+ * the packet to the minimum ethernet frame size, if necessary,
	30	+ * before adding the trailer.
	31	+ */
	32	+ padlen = 0;
	33	+ if (skb->len < 60)
	34	+ padlen = 60 - skb->len;
	35	+
	36	+ nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC);
	37	+ if (nskb == NULL) {
	38	+ kfree_skb(skb);
	39	+ return NETDEV_TX_OK;
	40	+ }
	41	+ skb_reserve(nskb, NET_IP_ALIGN);
	42	+
	43	+ skb_reset_mac_header(nskb);
	44	+ skb_set_network_header(nskb, skb_network_header(skb) - skb->head);
	45	+ skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head);
	46	+ skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
	47	+ kfree_skb(skb);
	48	+
	49	+ if (padlen) {
	50	+ u8 *pad = skb_put(nskb, padlen);
	51	+ memset(pad, 0, padlen);
	52	+ }
	53	+
	54	+ trailer = skb_put(nskb, 4);
	55	+ trailer[0] = 0x80;
	56	+ trailer[1] = 1 << p->port;
	57	+ trailer[2] = 0x10;
	58	+ trailer[3] = 0x00;
	59	+
	60	+ nskb->protocol = htons(ETH_P_TRAILER);
	61	+
	62	+ nskb->dev = p->parent->master_netdev;
	63	+ dev_queue_xmit(nskb);
	64	+
	65	+ return NETDEV_TX_OK;
	66	+}
	67	+
	68	+static int trailer_rcv(struct sk_buff skb, struct net_device dev,
	69	+ struct packet_type pt, struct net_device orig_dev)
	70	+{
	71	+ struct dsa_switch *ds = dev->dsa_ptr;
	72	+ u8 *trailer;
	73	+ int source_port;
	74	+
	75	+ if (unlikely(ds == NULL))
	76	+ goto out_drop;
	77	+
	78	+ skb = skb_unshare(skb, GFP_ATOMIC);
	79	+ if (skb == NULL)
	80	+ goto out;
	81	+
	82	+ if (skb_linearize(skb))
	83	+ goto out_drop;
	84	+
	85	+ trailer = skb_tail_pointer(skb) - 4;
	86	+ if (trailer[0] != 0x80 \|\| (trailer[1] & 0xf8) != 0x00 \|\|
	87	+ (trailer[3] & 0xef) != 0x00 \|\| trailer[3] != 0x00)
	88	+ goto out_drop;
	89	+
	90	+ source_port = trailer[1] & 7;
	91	+ if (source_port >= DSA_MAX_PORTS \|\| ds->ports[source_port] == NULL)
	92	+ goto out_drop;
	93	+
	94	+ pskb_trim_rcsum(skb, skb->len - 4);
	95	+
	96	+ skb->dev = ds->ports[source_port];
	97	+ skb_push(skb, ETH_HLEN);
	98	+ skb->protocol = eth_type_trans(skb, skb->dev);
	99	+
	100	+ skb->dev->last_rx = jiffies;
	101	+ skb->dev->stats.rx_packets++;
	102	+ skb->dev->stats.rx_bytes += skb->len;
	103	+
	104	+ netif_receive_skb(skb);
	105	+
	106	+ return 0;
	107	+
	108	+out_drop:
	109	+ kfree_skb(skb);
	110	+out:
	111	+ return 0;
	112	+}
	113	+
	114	+static struct packet_type trailer_packet_type = {
	115	+ .type = __constant_htons(ETH_P_TRAILER),
	116	+ .func = trailer_rcv,
	117	+};
	118	+
	119	+static int __init trailer_init_module(void)
	120	+{
	121	+ dev_add_pack(&trailer_packet_type);
	122	+ return 0;
	123	+}
	124	+module_init(trailer_init_module);
	125	+
	126	+static void __exit trailer_cleanup_module(void)
	127	+{
	128	+ dev_remove_pack(&trailer_packet_type);
	129	+}
	130	+module_exit(trailer_cleanup_module);
...	...	@@ -193,6 +193,8 @@
193	193	*/
194	194	if (netdev_uses_dsa_tags(dev))
195	195	return htons(ETH_P_DSA);
	196	+ if (netdev_uses_trailer_tags(dev))
	197	+ return htons(ETH_P_TRAILER);
196	198
197	199	if (ntohs(eth->h_proto) >= 1536)
198	200	return eth->h_proto;