1 /*
2  *	NET3:	Support for 802.2 demultiplexing off Ethernet (Token ring
3  *		is kept separate see p8022tr.c)
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *		Demultiplex 802.2 encoded protocols. We match the entry by the
10  *		SSAP/DSAP pair and then deliver to the registered datalink that
11  *		matches. The control byte is ignored and handling of such items
12  *		is up to the routine passed the frame.
13  *
14  *		Unlike the 802.3 datalink we have a list of 802.2 entries as
15  *		there are multiple protocols to demux. The list is currently
16  *		short (3 or 4 entries at most). The current demux assumes this.
17  */
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
20 #include <linux/skbuff.h>
21 #include <linux/slab.h>
22 #include <net/datalink.h>
23 #include <linux/mm.h>
24 #include <linux/in.h>
25 #include <linux/init.h>
26 #include <net/llc.h>
27 #include <net/p8022.h>
28 
p8022_request(struct datalink_proto * dl,struct sk_buff * skb,unsigned char * dest)29 static int p8022_request(struct datalink_proto *dl, struct sk_buff *skb,
30 			 unsigned char *dest)
31 {
32 	llc_build_and_send_ui_pkt(dl->sap, skb, dest, dl->sap->laddr.lsap);
33 	return 0;
34 }
35 
register_8022_client(unsigned char type,int (* func)(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev))36 struct datalink_proto *register_8022_client(unsigned char type,
37 					    int (*func)(struct sk_buff *skb,
38 							struct net_device *dev,
39 							struct packet_type *pt,
40 							struct net_device *orig_dev))
41 {
42 	struct datalink_proto *proto;
43 
44 	proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
45 	if (proto) {
46 		proto->type[0]		= type;
47 		proto->header_length	= 3;
48 		proto->request		= p8022_request;
49 		proto->sap = llc_sap_open(type, func);
50 		if (!proto->sap) {
51 			kfree(proto);
52 			proto = NULL;
53 		}
54 	}
55 	return proto;
56 }
57 
unregister_8022_client(struct datalink_proto * proto)58 void unregister_8022_client(struct datalink_proto *proto)
59 {
60 	llc_sap_put(proto->sap);
61 	kfree(proto);
62 }
63 
64 EXPORT_SYMBOL(register_8022_client);
65 EXPORT_SYMBOL(unregister_8022_client);
66 
67 MODULE_LICENSE("GPL");
68