WSL2-Linux-Kernel/net/llc/llc_station.c

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C
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/*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 11:04:11 +03:00
#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>
/**
* 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)
{
int 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);
}