mirror of https://gitee.com/openkylin/linux.git
124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
|
|
* llc_station.c - station component of LLC
|
|
*
|
|
* Copyright (c) 1997 by Procom Technology, Inc.
|
|
* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
|
|
*
|
|
* 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; /* 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; /* 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;
|
|
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;
|
|
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);
|
|
}
|