[linux.git] / net / llc / llc_station.c

/*
 * llc_station.c - station component of LLC
 *
 * Copyright (c) 1997 by Procom Technology, Inc.
 * 		 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
 *
 * This program can be redistributed or modified under the terms of the
 * GNU General Public License as published by the Free Software Foundation.
 * This program is distributed without any warranty or implied warranty
 * of merchantability or fitness for a particular purpose.
 *
 * See the GNU General Public License for more details.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <net/llc.h>
#include <net/llc_sap.h>
#include <net/llc_conn.h>
#include <net/llc_c_ac.h>
#include <net/llc_s_ac.h>
#include <net/llc_c_ev.h>
#include <net/llc_c_st.h>
#include <net/llc_s_ev.h>
#include <net/llc_s_st.h>
#include <net/llc_pdu.h>

static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
{
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
	       !pdu->dsap ? 0 : 1;			/* NULL DSAP value */
}

static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
{
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
	       !pdu->dsap ? 0 : 1;			/* NULL DSAP */
}

static int llc_station_ac_send_xid_r(struct sk_buff *skb)
{
	u8 mac_da[ETH_ALEN], dsap;
	int rc = 1;
	struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
					       sizeof(struct llc_xid_info));

	if (!nskb)
		goto out;
	rc = 0;
	llc_pdu_decode_sa(skb, mac_da);
	llc_pdu_decode_ssap(skb, &dsap);
	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
	llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127);
	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
	if (unlikely(rc))
		goto free;
	dev_queue_xmit(nskb);
out:
	return rc;
free:
	kfree_skb(nskb);
	goto out;
}

static int llc_station_ac_send_test_r(struct sk_buff *skb)
{
	u8 mac_da[ETH_ALEN], dsap;
	int rc = 1;
	u32 data_size;
	struct sk_buff *nskb;

	/* The test request command is type U (llc_len = 3) */
	data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
	nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);

	if (!nskb)
		goto out;
	rc = 0;
	llc_pdu_decode_sa(skb, mac_da);
	llc_pdu_decode_ssap(skb, &dsap);
	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
	llc_pdu_init_as_test_rsp(nskb, skb);
	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
	if (unlikely(rc))
		goto free;
	dev_queue_xmit(nskb);
out:
	return rc;
free:
	kfree_skb(nskb);
	goto out;
}

/**
 *	llc_station_rcv - send received pdu to the station state machine
 *	@skb: received frame.
 *
 *	Sends data unit to station state machine.
 */
static void llc_station_rcv(struct sk_buff *skb)
{
	if (llc_stat_ev_rx_null_dsap_xid_c(skb))
		llc_station_ac_send_xid_r(skb);
	else if (llc_stat_ev_rx_null_dsap_test_c(skb))
		llc_station_ac_send_test_r(skb);
	kfree_skb(skb);
}

void __init llc_station_init(void)
{
	llc_set_station_handler(llc_station_rcv);
}

void llc_station_exit(void)
{
	llc_set_station_handler(NULL);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* llc_station.c - station component of LLC
	3	*
	4	* Copyright (c) 1997 by Procom Technology, Inc.
	5	* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
	6	*
	7	* This program can be redistributed or modified under the terms of the
	8	* GNU General Public License as published by the Free Software Foundation.
	9	* This program is distributed without any warranty or implied warranty
	10	* of merchantability or fitness for a particular purpose.
	11	*
	12	* See the GNU General Public License for more details.
	13	*/
1da177e4 LT	14	#include <linux/init.h>
1da177e4 LT	15	#include <linux/module.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4 LT	17	#include <net/llc.h>
	18	#include <net/llc_sap.h>
	19	#include <net/llc_conn.h>
	20	#include <net/llc_c_ac.h>
	21	#include <net/llc_s_ac.h>
	22	#include <net/llc_c_ev.h>
	23	#include <net/llc_c_st.h>
	24	#include <net/llc_s_ev.h>
	25	#include <net/llc_s_st.h>
	26	#include <net/llc_pdu.h>
	27
1da177e4 LT	28	static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
1da177e4 LT	29	{
1da177e4 LT	30	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
1da177e4 LT	31
025e3633	32	return LLC_PDU_IS_CMD(pdu) && /* command PDU */
1da177e4 LT	33	LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
	34	LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
	35	!pdu->dsap ? 0 : 1; /* NULL DSAP value */
	36	}
	37
1da177e4 LT	38	static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
1da177e4 LT	39	{
1da177e4 LT	40	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
1da177e4 LT	41
025e3633	42	return LLC_PDU_IS_CMD(pdu) && /* command PDU */
1da177e4 LT	43	LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
	44	LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
	45	!pdu->dsap ? 0 : 1; /* NULL DSAP */
	46	}
	47
1da177e4 LT	48	static int llc_station_ac_send_xid_r(struct sk_buff *skb)
	49	{
	50	u8 mac_da[ETH_ALEN], dsap;
	51	int rc = 1;
f83f1768 JP	52	struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
f83f1768 JP	53	sizeof(struct llc_xid_info));
1da177e4 LT	54
	55	if (!nskb)
	56	goto out;
	57	rc = 0;
1da177e4 LT	58	llc_pdu_decode_sa(skb, mac_da);
	59	llc_pdu_decode_ssap(skb, &dsap);
	60	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
	61	llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127);
a5a04819	62	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
249ff1c6	63	if (unlikely(rc))
1da177e4	64	goto free;
5ecf9eea	65	dev_queue_xmit(nskb);
1da177e4 LT	66	out:
	67	return rc;
	68	free:
91d27a86	69	kfree_skb(nskb);
1da177e4 LT	70	goto out;
	71	}
	72
	73	static int llc_station_ac_send_test_r(struct sk_buff *skb)
	74	{
	75	u8 mac_da[ETH_ALEN], dsap;
	76	int rc = 1;
f83f1768 JP	77	u32 data_size;
	78	struct sk_buff *nskb;
	79
	80	/* The test request command is type U (llc_len = 3) */
	81	data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
	82	nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
1da177e4 LT	83
	84	if (!nskb)
	85	goto out;
	86	rc = 0;
1da177e4 LT	87	llc_pdu_decode_sa(skb, mac_da);
	88	llc_pdu_decode_ssap(skb, &dsap);
	89	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
d57b1869	90	llc_pdu_init_as_test_rsp(nskb, skb);
a5a04819	91	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
249ff1c6	92	if (unlikely(rc))
1da177e4	93	goto free;
5ecf9eea	94	dev_queue_xmit(nskb);
1da177e4 LT	95	out:
	96	return rc;
	97	free:
91d27a86	98	kfree_skb(nskb);
1da177e4 LT	99	goto out;
	100	}
	101
2c53040f	102	/**
1da177e4 LT	103	* llc_station_rcv - send received pdu to the station state machine
	104	* @skb: received frame.
	105	*
	106	* Sends data unit to station state machine.
	107	*/
	108	static void llc_station_rcv(struct sk_buff *skb)
	109	{
12ebc8b9 BH	110	if (llc_stat_ev_rx_null_dsap_xid_c(skb))
	111	llc_station_ac_send_xid_r(skb);
	112	else if (llc_stat_ev_rx_null_dsap_test_c(skb))
	113	llc_station_ac_send_test_r(skb);
04d191c2	114	kfree_skb(skb);
1da177e4 LT	115	}
1da177e4 LT	116
6024935f	117	void __init llc_station_init(void)
1da177e4	118	{
aadf31de	119	llc_set_station_handler(llc_station_rcv);
1da177e4 LT	120	}
1da177e4 LT	121
f4f8720f	122	void llc_station_exit(void)
1da177e4 LT	123	{
	124	llc_set_station_handler(NULL);
	125	}