entered into RCS

1 files changed, 123 insertions, 0 deletions

diff --git a/pfinet/linux-inet/psnap.c b/pfinet/linux-inet/psnap.c
new file mode 100644
index 00000000..287b3353
--- /dev/null
+++ b/pfinet/linux-inet/psnap.c
@@ -0,0 +1,123 @@
+/*
+ *	SNAP data link layer. Derived from 802.2
+ *
+ *		Alan Cox <Alan.Cox@linux.org>, from the 802.2 layer by Greg Page.
+ *		Merged in additions from Greg Page's psnap.c.
+ *
+ *		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/netdevice.h>
+#include <linux/skbuff.h>
+#include "datalink.h"
+#include "p8022.h"
+#include "psnap.h"
+#include <linux/mm.h>
+#include <linux/in.h>
+
+static struct datalink_proto *snap_list = NULL;
+static struct datalink_proto *snap_dl = NULL;		/* 802.2 DL for SNAP */
+
+/*
+ *	Find a snap client by matching the 5 bytes.
+ */
+ 
+static struct datalink_proto *find_snap_client(unsigned char *desc)
+{
+	struct datalink_proto	*proto;
+
+	for (proto = snap_list; proto != NULL && memcmp(proto->type, desc, 5) ; proto = proto->next);
+	return proto;
+}
+
+/*
+ *	A SNAP packet has arrived
+ */
+ 
+int snap_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
+{
+	static struct packet_type psnap_packet_type = 
+	{
+		0,	
+		NULL,		/* All Devices */
+		snap_rcv,
+		NULL,
+		NULL,
+	};
+	
+	struct datalink_proto	*proto;
+
+	proto = find_snap_client(skb->h.raw);
+	if (proto != NULL) 
+	{
+		/*
+		 *	Pass the frame on.
+		 */
+		 
+		skb->h.raw += 5;
+		skb->len -= 5;
+		if (psnap_packet_type.type == 0)
+			psnap_packet_type.type=htons(ETH_P_SNAP);
+		return proto->rcvfunc(skb, dev, &psnap_packet_type);
+	}
+	skb->sk = NULL;
+	kfree_skb(skb, FREE_READ);
+	return 0;
+}
+
+/*
+ *	Put a SNAP header on a frame and pass to 802.2
+ */
+ 
+static void snap_datalink_header(struct datalink_proto *dl, struct sk_buff *skb, unsigned char *dest_node)
+{
+	struct device	*dev = skb->dev;
+	unsigned char	*rawp;
+
+	rawp = skb->data + snap_dl->header_length+dev->hard_header_len;
+	memcpy(rawp,dl->type,5);
+	skb->h.raw = rawp+5;
+	snap_dl->datalink_header(snap_dl, skb, dest_node);
+}
+
+/*
+ *	Set up the SNAP layer
+ */
+ 
+void snap_proto_init(struct net_proto *pro)
+{
+	snap_dl=register_8022_client(0xAA, snap_rcv);
+	if(snap_dl==NULL)
+		printk("SNAP - unable to register with 802.2\n");
+}
+	
+/*
+ *	Register SNAP clients. We don't yet use this for IP or IPX.
+ */
+ 
+struct datalink_proto *register_snap_client(unsigned char *desc, int (*rcvfunc)(struct sk_buff *, struct device *, struct packet_type *))
+{
+	struct datalink_proto	*proto;
+
+	if (find_snap_client(desc) != NULL)
+		return NULL;
+
+	proto = (struct datalink_proto *) kmalloc(sizeof(*proto), GFP_ATOMIC);
+	if (proto != NULL) 
+	{
+		memcpy(proto->type, desc,5);
+		proto->type_len = 5;
+		proto->rcvfunc = rcvfunc;
+		proto->header_length = 5+snap_dl->header_length;
+		proto->datalink_header = snap_datalink_header;
+		proto->string_name = "SNAP";
+		proto->next = snap_list;
+		snap_list = proto;
+	}
+
+	return proto;
+}
+