1/*
2 * llc_output.c - LLC minimal output path
3 *
4 * Copyright (c) 1997 by Procom Technology, Inc.
5 * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program can be redistributed or modified under the terms of the
8 * GNU General Public License version 2 as published by the Free Software
9 * Foundation.
10 * This program is distributed without any warranty or implied warranty
11 * of merchantability or fitness for a particular purpose.
12 *
13 * See the GNU General Public License version 2 for more details.
14 */
15
16#include <linux/if_arp.h>
17#include <linux/if_tr.h>
18#include <linux/netdevice.h>
19#include <linux/trdevice.h>
20#include <linux/skbuff.h>
21#include <net/llc.h>
22#include <net/llc_pdu.h>
23
24/**
25 *	llc_mac_hdr_init - fills MAC header fields
26 *	@skb: Address of the frame to initialize its MAC header
27 *	@sa: The MAC source address
28 *	@da: The MAC destination address
29 *
30 *	Fills MAC header fields, depending on MAC type. Returns 0, If MAC type
31 *	is a valid type and initialization completes correctly 1, otherwise.
32 */
33int llc_mac_hdr_init(struct sk_buff *skb,
34		     const unsigned char *sa, const unsigned char *da)
35{
36	int rc = 0;
37
38	switch (skb->dev->type) {
39#ifdef CONFIG_TR
40	case ARPHRD_IEEE802_TR: {
41		struct net_device *dev = skb->dev;
42		struct trh_hdr *trh;
43
44		skb_push(skb, sizeof(*trh));
45		skb_reset_mac_header(skb);
46		trh = tr_hdr(skb);
47		trh->ac = AC;
48		trh->fc = LLC_FRAME;
49		if (sa)
50			memcpy(trh->saddr, sa, dev->addr_len);
51		else
52			memset(trh->saddr, 0, dev->addr_len);
53		if (da) {
54			memcpy(trh->daddr, da, dev->addr_len);
55			tr_source_route(skb, trh, dev);
56			skb_reset_mac_header(skb);
57		}
58		break;
59	}
60#endif
61	case ARPHRD_ETHER:
62	case ARPHRD_LOOPBACK: {
63		unsigned short len = skb->len;
64		struct ethhdr *eth;
65
66		skb_push(skb, sizeof(*eth));
67		skb_reset_mac_header(skb);
68		eth = eth_hdr(skb);
69		eth->h_proto = htons(len);
70		memcpy(eth->h_dest, da, ETH_ALEN);
71		memcpy(eth->h_source, sa, ETH_ALEN);
72		break;
73	}
74	default:
75		printk(KERN_WARNING "device type not supported: %d\n",
76		       skb->dev->type);
77		rc = -EINVAL;
78	}
79	return rc;
80}
81
82/**
83 *	llc_build_and_send_ui_pkt - unitdata request interface for upper layers
84 *	@sap: sap to use
85 *	@skb: packet to send
86 *	@dmac: destination mac address
87 *	@dsap: destination sap
88 *
89 *	Upper layers calls this function when upper layer wants to send data
90 *	using connection-less mode communication (UI pdu).
91 *
92 *	Accept data frame from network layer to be sent using connection-
93 *	less mode communication; timeout/retries handled by network layer;
94 *	package primitive as an event and send to SAP event handler
95 */
96int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
97			      unsigned char *dmac, unsigned char dsap)
98{
99	int rc;
100	llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
101			    dsap, LLC_PDU_CMD);
102	llc_pdu_init_as_ui_cmd(skb);
103	rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
104	if (likely(!rc))
105		rc = dev_queue_xmit(skb);
106	return rc;
107}
108
109EXPORT_SYMBOL(llc_mac_hdr_init);
110EXPORT_SYMBOL(llc_build_and_send_ui_pkt);
111