diff options
Diffstat (limited to 'net/llc/llc_station.c')
| -rw-r--r-- | net/llc/llc_station.c | 721 |
1 files changed, 721 insertions, 0 deletions
diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c new file mode 100644 index 0000000..83da133 --- /dev/null +++ b/net/llc/llc_station.c @@ -0,0 +1,721 @@ +/* + * 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 <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; +}; + +#define LLC_STATION_ACK_TIME (3 * HZ) + +int sysctl_llc_station_ack_timeout = LLC_STATION_ACK_TIME; + +/* 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 + sysctl_llc_station_ack_timeout); + 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(NULL, skb->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_xid_info)); + + 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, skb->dev->dev_addr, skb->dev->dev_addr); + if (unlikely(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(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; + 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; + 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; + 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); + setup_timer(&llc_main_station.ack_timer, llc_station_ack_tmr_cb, + (unsigned long)&llc_main_station); + llc_main_station.ack_timer.expires = jiffies + + sysctl_llc_station_ack_timeout; + 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.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); +} |
