llc_output.c revision 249ff1c6d35fd32ca945967c3f0b948210a96baa 
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, unsigned char *sa, unsigned char *da)
34{
35	int rc = 0;
36
37	switch (skb->dev->type) {
38#ifdef CONFIG_TR
39	case ARPHRD_IEEE802_TR: {
40		struct net_device *dev = skb->dev;
41		struct trh_hdr *trh;
42
43		skb->mac.raw = skb_push(skb, sizeof(*trh));
44		trh = tr_hdr(skb);
45		trh->ac = AC;
46		trh->fc = LLC_FRAME;
47		if (sa)
48			memcpy(trh->saddr, sa, dev->addr_len);
49		else
50			memset(trh->saddr, 0, dev->addr_len);
51		if (da) {
52			memcpy(trh->daddr, da, dev->addr_len);
53			tr_source_route(skb, trh, dev);
54			skb->mac.raw = skb->data;
55		}
56		break;
57	}
58#endif
59	case ARPHRD_ETHER:
60	case ARPHRD_LOOPBACK: {
61		unsigned short len = skb->len;
62		struct ethhdr *eth;
63
64		skb->mac.raw = skb_push(skb, sizeof(*eth));
65		eth = eth_hdr(skb);
66		eth->h_proto = htons(len);
67		memcpy(eth->h_dest, da, ETH_ALEN);
68		memcpy(eth->h_source, sa, ETH_ALEN);
69		break;
70	}
71	default:
72		printk(KERN_WARNING "device type not supported: %d\n",
73		       skb->dev->type);
74		rc = -EINVAL;
75	}
76	return rc;
77}
78
79/**
80 *	llc_build_and_send_ui_pkt - unitdata request interface for upper layers
81 *	@sap: sap to use
82 *	@skb: packet to send
83 *	@dmac: destination mac address
84 *	@dsap: destination sap
85 *
86 *	Upper layers calls this function when upper layer wants to send data
87 *	using connection-less mode communication (UI pdu).
88 *
89 *	Accept data frame from network layer to be sent using connection-
90 *	less mode communication; timeout/retries handled by network layer;
91 *	package primitive as an event and send to SAP event handler
92 */
93int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
94			      unsigned char *dmac, unsigned char dsap)
95{
96	int rc;
97	llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
98			    dsap, LLC_PDU_CMD);
99	llc_pdu_init_as_ui_cmd(skb);
100	rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
101	if (likely(!rc))
102		rc = dev_queue_xmit(skb);
103	return rc;
104}
105
106EXPORT_SYMBOL(llc_mac_hdr_init);
107EXPORT_SYMBOL(llc_build_and_send_ui_pkt);
108