1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * NET3: Support for 802.2 demultiplexing off Ethernet |
4 | * |
5 | * Demultiplex 802.2 encoded protocols. We match the entry by the |
6 | * SSAP/DSAP pair and then deliver to the registered datalink that |
7 | * matches. The control byte is ignored and handling of such items |
8 | * is up to the routine passed the frame. |
9 | * |
10 | * Unlike the 802.3 datalink we have a list of 802.2 entries as |
11 | * there are multiple protocols to demux. The list is currently |
12 | * short (3 or 4 entries at most). The current demux assumes this. |
13 | */ |
14 | #include <linux/module.h> |
15 | #include <linux/netdevice.h> |
16 | #include <linux/skbuff.h> |
17 | #include <linux/slab.h> |
18 | #include <net/datalink.h> |
19 | #include <linux/mm.h> |
20 | #include <linux/in.h> |
21 | #include <linux/init.h> |
22 | #include <net/llc.h> |
23 | #include <net/p8022.h> |
24 | |
25 | static int p8022_request(struct datalink_proto *dl, struct sk_buff *skb, |
26 | const unsigned char *dest) |
27 | { |
28 | llc_build_and_send_ui_pkt(sap: dl->sap, skb, dmac: dest, dsap: dl->sap->laddr.lsap); |
29 | return 0; |
30 | } |
31 | |
32 | struct datalink_proto *register_8022_client(unsigned char type, |
33 | int (*func)(struct sk_buff *skb, |
34 | struct net_device *dev, |
35 | struct packet_type *pt, |
36 | struct net_device *orig_dev)) |
37 | { |
38 | struct datalink_proto *proto; |
39 | |
40 | proto = kmalloc(size: sizeof(*proto), GFP_ATOMIC); |
41 | if (proto) { |
42 | proto->type[0] = type; |
43 | proto->header_length = 3; |
44 | proto->request = p8022_request; |
45 | proto->sap = llc_sap_open(lsap: type, rcv: func); |
46 | if (!proto->sap) { |
47 | kfree(objp: proto); |
48 | proto = NULL; |
49 | } |
50 | } |
51 | return proto; |
52 | } |
53 | |
54 | void unregister_8022_client(struct datalink_proto *proto) |
55 | { |
56 | llc_sap_put(sap: proto->sap); |
57 | kfree(objp: proto); |
58 | } |
59 | |
60 | EXPORT_SYMBOL(register_8022_client); |
61 | EXPORT_SYMBOL(unregister_8022_client); |
62 | |
63 | MODULE_DESCRIPTION("Support for 802.2 demultiplexing off Ethernet" ); |
64 | MODULE_LICENSE("GPL" ); |
65 | |