1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
714 lines
20 KiB
C
714 lines
20 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/config.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.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>
|
|
|
|
/**
|
|
* struct llc_station - LLC station component
|
|
*
|
|
* SAP and connection resource manager, one per adapter.
|
|
*
|
|
* @state - state of station
|
|
* @xid_r_count - XID response PDU counter
|
|
* @mac_sa - MAC source address
|
|
* @sap_list - list of related SAPs
|
|
* @ev_q - events entering state mach.
|
|
* @mac_pdu_q - PDUs ready to send to MAC
|
|
*/
|
|
struct llc_station {
|
|
u8 state;
|
|
u8 xid_r_count;
|
|
struct timer_list ack_timer;
|
|
u8 retry_count;
|
|
u8 maximum_retry;
|
|
struct {
|
|
struct sk_buff_head list;
|
|
spinlock_t lock;
|
|
} ev_q;
|
|
struct sk_buff_head mac_pdu_q;
|
|
};
|
|
|
|
/* Types of events (possible values in 'ev->type') */
|
|
#define LLC_STATION_EV_TYPE_SIMPLE 1
|
|
#define LLC_STATION_EV_TYPE_CONDITION 2
|
|
#define LLC_STATION_EV_TYPE_PRIM 3
|
|
#define LLC_STATION_EV_TYPE_PDU 4 /* command/response PDU */
|
|
#define LLC_STATION_EV_TYPE_ACK_TMR 5
|
|
#define LLC_STATION_EV_TYPE_RPT_STATUS 6
|
|
|
|
/* Events */
|
|
#define LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK 1
|
|
#define LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK 2
|
|
#define LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY 3
|
|
#define LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY 4
|
|
#define LLC_STATION_EV_RX_NULL_DSAP_XID_C 5
|
|
#define LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ 6
|
|
#define LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ 7
|
|
#define LLC_STATION_EV_RX_NULL_DSAP_TEST_C 8
|
|
#define LLC_STATION_EV_DISABLE_REQ 9
|
|
|
|
struct llc_station_state_ev {
|
|
u8 type;
|
|
u8 prim;
|
|
u8 prim_type;
|
|
u8 reason;
|
|
struct list_head node; /* node in station->ev_q.list */
|
|
};
|
|
|
|
static __inline__ struct llc_station_state_ev *
|
|
llc_station_ev(struct sk_buff *skb)
|
|
{
|
|
return (struct llc_station_state_ev *)skb->cb;
|
|
}
|
|
|
|
typedef int (*llc_station_ev_t)(struct sk_buff *skb);
|
|
|
|
#define LLC_STATION_STATE_DOWN 1 /* initial state */
|
|
#define LLC_STATION_STATE_DUP_ADDR_CHK 2
|
|
#define LLC_STATION_STATE_UP 3
|
|
|
|
#define LLC_NBR_STATION_STATES 3 /* size of state table */
|
|
|
|
typedef int (*llc_station_action_t)(struct sk_buff *skb);
|
|
|
|
/* Station component state table structure */
|
|
struct llc_station_state_trans {
|
|
llc_station_ev_t ev;
|
|
u8 next_state;
|
|
llc_station_action_t *ev_actions;
|
|
};
|
|
|
|
struct llc_station_state {
|
|
u8 curr_state;
|
|
struct llc_station_state_trans **transitions;
|
|
};
|
|
|
|
static struct llc_station llc_main_station;
|
|
|
|
static int llc_stat_ev_enable_with_dup_addr_check(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_SIMPLE &&
|
|
ev->prim_type ==
|
|
LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_enable_without_dup_addr_check(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_SIMPLE &&
|
|
ev->prim_type ==
|
|
LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_ACK_TMR &&
|
|
llc_main_station.retry_count <
|
|
llc_main_station.maximum_retry ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_ACK_TMR &&
|
|
llc_main_station.retry_count ==
|
|
llc_main_station.maximum_retry ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_PDU &&
|
|
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_0_xid_r_xid_r_cnt_eq(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_PDU &&
|
|
LLC_PDU_IS_RSP(pdu) && /* response PDU */
|
|
LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
|
|
LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID &&
|
|
!pdu->dsap && /* NULL DSAP value */
|
|
!llc_main_station.xid_r_count ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_PDU &&
|
|
LLC_PDU_IS_RSP(pdu) && /* response PDU */
|
|
LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
|
|
LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_XID &&
|
|
!pdu->dsap && /* NULL DSAP value */
|
|
llc_main_station.xid_r_count == 1 ? 0 : 1;
|
|
}
|
|
|
|
static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_PDU &&
|
|
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_stat_ev_disable_req(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
return ev->type == LLC_STATION_EV_TYPE_PRIM &&
|
|
ev->prim == LLC_DISABLE_PRIM &&
|
|
ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
|
|
}
|
|
|
|
/**
|
|
* llc_station_send_pdu - queues PDU to send
|
|
* @skb: Address of the PDU
|
|
*
|
|
* Queues a PDU to send to the MAC layer.
|
|
*/
|
|
static void llc_station_send_pdu(struct sk_buff *skb)
|
|
{
|
|
skb_queue_tail(&llc_main_station.mac_pdu_q, skb);
|
|
while ((skb = skb_dequeue(&llc_main_station.mac_pdu_q)) != NULL)
|
|
if (dev_queue_xmit(skb))
|
|
break;
|
|
}
|
|
|
|
static int llc_station_ac_start_ack_timer(struct sk_buff *skb)
|
|
{
|
|
mod_timer(&llc_main_station.ack_timer, jiffies + LLC_ACK_TIME * HZ);
|
|
return 0;
|
|
}
|
|
|
|
static int llc_station_ac_set_retry_cnt_0(struct sk_buff *skb)
|
|
{
|
|
llc_main_station.retry_count = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int llc_station_ac_inc_retry_cnt_by_1(struct sk_buff *skb)
|
|
{
|
|
llc_main_station.retry_count++;
|
|
return 0;
|
|
}
|
|
|
|
static int llc_station_ac_set_xid_r_cnt_0(struct sk_buff *skb)
|
|
{
|
|
llc_main_station.xid_r_count = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int llc_station_ac_inc_xid_r_cnt_by_1(struct sk_buff *skb)
|
|
{
|
|
llc_main_station.xid_r_count++;
|
|
return 0;
|
|
}
|
|
|
|
static int llc_station_ac_send_null_dsap_xid_c(struct sk_buff *skb)
|
|
{
|
|
int rc = 1;
|
|
struct sk_buff *nskb = llc_alloc_frame();
|
|
|
|
if (!nskb)
|
|
goto out;
|
|
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, 0, LLC_PDU_CMD);
|
|
llc_pdu_init_as_xid_cmd(nskb, LLC_XID_NULL_CLASS_2, 127);
|
|
rc = llc_mac_hdr_init(nskb, llc_station_mac_sa, llc_station_mac_sa);
|
|
if (rc)
|
|
goto free;
|
|
llc_station_send_pdu(nskb);
|
|
out:
|
|
return rc;
|
|
free:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
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();
|
|
|
|
if (!nskb)
|
|
goto out;
|
|
rc = 0;
|
|
nskb->dev = skb->dev;
|
|
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, llc_station_mac_sa, mac_da);
|
|
if (rc)
|
|
goto free;
|
|
llc_station_send_pdu(nskb);
|
|
out:
|
|
return rc;
|
|
free:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
static int llc_station_ac_send_test_r(struct sk_buff *skb)
|
|
{
|
|
u8 mac_da[ETH_ALEN], dsap;
|
|
int rc = 1;
|
|
struct sk_buff *nskb = llc_alloc_frame();
|
|
|
|
if (!nskb)
|
|
goto out;
|
|
rc = 0;
|
|
nskb->dev = skb->dev;
|
|
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, llc_station_mac_sa, mac_da);
|
|
if (rc)
|
|
goto free;
|
|
llc_station_send_pdu(nskb);
|
|
out:
|
|
return rc;
|
|
free:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
static int llc_station_ac_report_status(struct sk_buff *skb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* COMMON STATION STATE transitions */
|
|
|
|
/* dummy last-transition indicator; common to all state transition groups
|
|
* last entry for this state
|
|
* all members are zeros, .bss zeroes it
|
|
*/
|
|
static struct llc_station_state_trans llc_stat_state_trans_end;
|
|
|
|
/* DOWN STATE transitions */
|
|
|
|
/* state transition for LLC_STATION_EV_ENABLE_WITH_DUP_ADDR_CHECK event */
|
|
static llc_station_action_t llc_stat_down_state_actions_1[] = {
|
|
[0] = llc_station_ac_start_ack_timer,
|
|
[1] = llc_station_ac_set_retry_cnt_0,
|
|
[2] = llc_station_ac_set_xid_r_cnt_0,
|
|
[3] = llc_station_ac_send_null_dsap_xid_c,
|
|
[4] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_down_state_trans_1 = {
|
|
.ev = llc_stat_ev_enable_with_dup_addr_check,
|
|
.next_state = LLC_STATION_STATE_DUP_ADDR_CHK,
|
|
.ev_actions = llc_stat_down_state_actions_1,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK event */
|
|
static llc_station_action_t llc_stat_down_state_actions_2[] = {
|
|
[0] = llc_station_ac_report_status, /* STATION UP */
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_down_state_trans_2 = {
|
|
.ev = llc_stat_ev_enable_without_dup_addr_check,
|
|
.next_state = LLC_STATION_STATE_UP,
|
|
.ev_actions = llc_stat_down_state_actions_2,
|
|
};
|
|
|
|
/* array of pointers; one to each transition */
|
|
static struct llc_station_state_trans *llc_stat_dwn_state_trans[] = {
|
|
[0] = &llc_stat_down_state_trans_1,
|
|
[1] = &llc_stat_down_state_trans_2,
|
|
[2] = &llc_stat_state_trans_end,
|
|
};
|
|
|
|
/* UP STATE transitions */
|
|
/* state transition for LLC_STATION_EV_DISABLE_REQ event */
|
|
static llc_station_action_t llc_stat_up_state_actions_1[] = {
|
|
[0] = llc_station_ac_report_status, /* STATION DOWN */
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_up_state_trans_1 = {
|
|
.ev = llc_stat_ev_disable_req,
|
|
.next_state = LLC_STATION_STATE_DOWN,
|
|
.ev_actions = llc_stat_up_state_actions_1,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */
|
|
static llc_station_action_t llc_stat_up_state_actions_2[] = {
|
|
[0] = llc_station_ac_send_xid_r,
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_up_state_trans_2 = {
|
|
.ev = llc_stat_ev_rx_null_dsap_xid_c,
|
|
.next_state = LLC_STATION_STATE_UP,
|
|
.ev_actions = llc_stat_up_state_actions_2,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_RX_NULL_DSAP_TEST_C event */
|
|
static llc_station_action_t llc_stat_up_state_actions_3[] = {
|
|
[0] = llc_station_ac_send_test_r,
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_up_state_trans_3 = {
|
|
.ev = llc_stat_ev_rx_null_dsap_test_c,
|
|
.next_state = LLC_STATION_STATE_UP,
|
|
.ev_actions = llc_stat_up_state_actions_3,
|
|
};
|
|
|
|
/* array of pointers; one to each transition */
|
|
static struct llc_station_state_trans *llc_stat_up_state_trans [] = {
|
|
[0] = &llc_stat_up_state_trans_1,
|
|
[1] = &llc_stat_up_state_trans_2,
|
|
[2] = &llc_stat_up_state_trans_3,
|
|
[3] = &llc_stat_state_trans_end,
|
|
};
|
|
|
|
/* DUP ADDR CHK STATE transitions */
|
|
/* state transition for LLC_STATION_EV_RX_NULL_DSAP_0_XID_R_XID_R_CNT_EQ
|
|
* event
|
|
*/
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_1[] = {
|
|
[0] = llc_station_ac_inc_xid_r_cnt_by_1,
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_1 = {
|
|
.ev = llc_stat_ev_rx_null_dsap_0_xid_r_xid_r_cnt_eq,
|
|
.next_state = LLC_STATION_STATE_DUP_ADDR_CHK,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_1,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_RX_NULL_DSAP_1_XID_R_XID_R_CNT_EQ
|
|
* event
|
|
*/
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_2[] = {
|
|
[0] = llc_station_ac_report_status, /* DUPLICATE ADDRESS FOUND */
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_2 = {
|
|
.ev = llc_stat_ev_rx_null_dsap_1_xid_r_xid_r_cnt_eq,
|
|
.next_state = LLC_STATION_STATE_DOWN,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_2,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_RX_NULL_DSAP_XID_C event */
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_3[] = {
|
|
[0] = llc_station_ac_send_xid_r,
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_3 = {
|
|
.ev = llc_stat_ev_rx_null_dsap_xid_c,
|
|
.next_state = LLC_STATION_STATE_DUP_ADDR_CHK,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_3,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_ACK_TMR_EXP_LT_RETRY_CNT_MAX_RETRY
|
|
* event
|
|
*/
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_4[] = {
|
|
[0] = llc_station_ac_start_ack_timer,
|
|
[1] = llc_station_ac_inc_retry_cnt_by_1,
|
|
[2] = llc_station_ac_set_xid_r_cnt_0,
|
|
[3] = llc_station_ac_send_null_dsap_xid_c,
|
|
[4] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_4 = {
|
|
.ev = llc_stat_ev_ack_tmr_exp_lt_retry_cnt_max_retry,
|
|
.next_state = LLC_STATION_STATE_DUP_ADDR_CHK,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_4,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_ACK_TMR_EXP_EQ_RETRY_CNT_MAX_RETRY
|
|
* event
|
|
*/
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_5[] = {
|
|
[0] = llc_station_ac_report_status, /* STATION UP */
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_5 = {
|
|
.ev = llc_stat_ev_ack_tmr_exp_eq_retry_cnt_max_retry,
|
|
.next_state = LLC_STATION_STATE_UP,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_5,
|
|
};
|
|
|
|
/* state transition for LLC_STATION_EV_DISABLE_REQ event */
|
|
static llc_station_action_t llc_stat_dupaddr_state_actions_6[] = {
|
|
[0] = llc_station_ac_report_status, /* STATION DOWN */
|
|
[1] = NULL,
|
|
};
|
|
|
|
static struct llc_station_state_trans llc_stat_dupaddr_state_trans_6 = {
|
|
.ev = llc_stat_ev_disable_req,
|
|
.next_state = LLC_STATION_STATE_DOWN,
|
|
.ev_actions = llc_stat_dupaddr_state_actions_6,
|
|
};
|
|
|
|
/* array of pointers; one to each transition */
|
|
static struct llc_station_state_trans *llc_stat_dupaddr_state_trans[] = {
|
|
[0] = &llc_stat_dupaddr_state_trans_6, /* Request */
|
|
[1] = &llc_stat_dupaddr_state_trans_4, /* Timer */
|
|
[2] = &llc_stat_dupaddr_state_trans_5,
|
|
[3] = &llc_stat_dupaddr_state_trans_1, /* Receive frame */
|
|
[4] = &llc_stat_dupaddr_state_trans_2,
|
|
[5] = &llc_stat_dupaddr_state_trans_3,
|
|
[6] = &llc_stat_state_trans_end,
|
|
};
|
|
|
|
static struct llc_station_state
|
|
llc_station_state_table[LLC_NBR_STATION_STATES] = {
|
|
[LLC_STATION_STATE_DOWN - 1] = {
|
|
.curr_state = LLC_STATION_STATE_DOWN,
|
|
.transitions = llc_stat_dwn_state_trans,
|
|
},
|
|
[LLC_STATION_STATE_DUP_ADDR_CHK - 1] = {
|
|
.curr_state = LLC_STATION_STATE_DUP_ADDR_CHK,
|
|
.transitions = llc_stat_dupaddr_state_trans,
|
|
},
|
|
[LLC_STATION_STATE_UP - 1] = {
|
|
.curr_state = LLC_STATION_STATE_UP,
|
|
.transitions = llc_stat_up_state_trans,
|
|
},
|
|
};
|
|
|
|
/**
|
|
* llc_exec_station_trans_actions - executes actions for transition
|
|
* @trans: Address of the transition
|
|
* @skb: Address of the event that caused the transition
|
|
*
|
|
* Executes actions of a transition of the station state machine. Returns
|
|
* 0 if all actions complete successfully, nonzero otherwise.
|
|
*/
|
|
static u16 llc_exec_station_trans_actions(struct llc_station_state_trans *trans,
|
|
struct sk_buff *skb)
|
|
{
|
|
u16 rc = 0;
|
|
llc_station_action_t *next_action = trans->ev_actions;
|
|
|
|
for (; next_action && *next_action; next_action++)
|
|
if ((*next_action)(skb))
|
|
rc = 1;
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* llc_find_station_trans - finds transition for this event
|
|
* @skb: Address of the event
|
|
*
|
|
* Search thru events of the current state of the station until list
|
|
* exhausted or it's obvious that the event is not valid for the current
|
|
* state. Returns the address of the transition if cound, %NULL otherwise.
|
|
*/
|
|
static struct llc_station_state_trans *
|
|
llc_find_station_trans(struct sk_buff *skb)
|
|
{
|
|
int i = 0;
|
|
struct llc_station_state_trans *rc = NULL;
|
|
struct llc_station_state_trans **next_trans;
|
|
struct llc_station_state *curr_state =
|
|
&llc_station_state_table[llc_main_station.state - 1];
|
|
|
|
for (next_trans = curr_state->transitions; next_trans[i]->ev; i++)
|
|
if (!next_trans[i]->ev(skb)) {
|
|
rc = next_trans[i];
|
|
break;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* llc_station_free_ev - frees an event
|
|
* @skb: Address of the event
|
|
*
|
|
* Frees an event.
|
|
*/
|
|
static void llc_station_free_ev(struct sk_buff *skb)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
if (ev->type == LLC_STATION_EV_TYPE_PDU)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/**
|
|
* llc_station_next_state - processes event and goes to the next state
|
|
* @skb: Address of the event
|
|
*
|
|
* Processes an event, executes any transitions related to that event and
|
|
* updates the state of the station.
|
|
*/
|
|
static u16 llc_station_next_state(struct sk_buff *skb)
|
|
{
|
|
u16 rc = 1;
|
|
struct llc_station_state_trans *trans;
|
|
|
|
if (llc_main_station.state > LLC_NBR_STATION_STATES)
|
|
goto out;
|
|
trans = llc_find_station_trans(skb);
|
|
if (trans) {
|
|
/* got the state to which we next transition; perform the
|
|
* actions associated with this transition before actually
|
|
* transitioning to the next state
|
|
*/
|
|
rc = llc_exec_station_trans_actions(trans, skb);
|
|
if (!rc)
|
|
/* transition station to next state if all actions
|
|
* execute successfully; done; wait for next event
|
|
*/
|
|
llc_main_station.state = trans->next_state;
|
|
} else
|
|
/* event not recognized in current state; re-queue it for
|
|
* processing again at a later time; return failure
|
|
*/
|
|
rc = 0;
|
|
out:
|
|
llc_station_free_ev(skb);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* llc_station_service_events - service events in the queue
|
|
*
|
|
* Get an event from the station event queue (if any); attempt to service
|
|
* the event; if event serviced, get the next event (if any) on the event
|
|
* queue; if event not service, re-queue the event on the event queue and
|
|
* attempt to service the next event; when serviced all events in queue,
|
|
* finished; if don't transition to different state, just service all
|
|
* events once; if transition to new state, service all events again.
|
|
* Caller must hold llc_main_station.ev_q.lock.
|
|
*/
|
|
static void llc_station_service_events(void)
|
|
{
|
|
struct sk_buff *skb;
|
|
|
|
while ((skb = skb_dequeue(&llc_main_station.ev_q.list)) != NULL)
|
|
llc_station_next_state(skb);
|
|
}
|
|
|
|
/**
|
|
* llc_station_state_process: queue event and try to process queue.
|
|
* @skb: Address of the event
|
|
*
|
|
* Queues an event (on the station event queue) for handling by the
|
|
* station state machine and attempts to process any queued-up events.
|
|
*/
|
|
static void llc_station_state_process(struct sk_buff *skb)
|
|
{
|
|
spin_lock_bh(&llc_main_station.ev_q.lock);
|
|
skb_queue_tail(&llc_main_station.ev_q.list, skb);
|
|
llc_station_service_events();
|
|
spin_unlock_bh(&llc_main_station.ev_q.lock);
|
|
}
|
|
|
|
static void llc_station_ack_tmr_cb(unsigned long timeout_data)
|
|
{
|
|
struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
|
|
|
|
if (skb) {
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
ev->type = LLC_STATION_EV_TYPE_ACK_TMR;
|
|
llc_station_state_process(skb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct llc_station_state_ev *ev = llc_station_ev(skb);
|
|
|
|
ev->type = LLC_STATION_EV_TYPE_PDU;
|
|
ev->reason = 0;
|
|
llc_station_state_process(skb);
|
|
}
|
|
|
|
int __init llc_station_init(void)
|
|
{
|
|
u16 rc = -ENOBUFS;
|
|
struct sk_buff *skb;
|
|
struct llc_station_state_ev *ev;
|
|
|
|
skb_queue_head_init(&llc_main_station.mac_pdu_q);
|
|
skb_queue_head_init(&llc_main_station.ev_q.list);
|
|
spin_lock_init(&llc_main_station.ev_q.lock);
|
|
init_timer(&llc_main_station.ack_timer);
|
|
llc_main_station.ack_timer.data = (unsigned long)&llc_main_station;
|
|
llc_main_station.ack_timer.function = llc_station_ack_tmr_cb;
|
|
|
|
skb = alloc_skb(0, GFP_ATOMIC);
|
|
if (!skb)
|
|
goto out;
|
|
rc = 0;
|
|
llc_set_station_handler(llc_station_rcv);
|
|
ev = llc_station_ev(skb);
|
|
memset(ev, 0, sizeof(*ev));
|
|
llc_main_station.ack_timer.expires = jiffies + 3 * HZ;
|
|
llc_main_station.maximum_retry = 1;
|
|
llc_main_station.state = LLC_STATION_STATE_DOWN;
|
|
ev->type = LLC_STATION_EV_TYPE_SIMPLE;
|
|
ev->prim_type = LLC_STATION_EV_ENABLE_WITHOUT_DUP_ADDR_CHECK;
|
|
rc = llc_station_next_state(skb);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
void __exit llc_station_exit(void)
|
|
{
|
|
llc_set_station_handler(NULL);
|
|
}
|