isdnl2.c

arm平台上的uclinux系统全部源代码

/* $Id: isdnl2.c,v 1.1.1.1 1999/11/15 13:42:18 vadim Exp $

 * Author       Karsten Keil ([e-mail])
 *              based on the teles driver from Jan den Ouden
 *
 *		This file is (c) under GNU PUBLIC LICENSE
 *		For changes and modifications please read
 *		../../../Documentation/isdn/HiSax.cert
 *
 * Thanks to    Jan den Ouden
 *              Fritz Elfert
 *
 * $Log: isdnl2.c,v $
 * Revision 1.1.1.1  1999/11/15 13:42:18  vadim
 * Initial import
 *
 * Revision 1.10.2.11  1998/11/03 00:06:57  keil
 * certification related changes
 * fixed logging for smaller stack use
 *
 * Revision 1.10.2.10  1998/09/27 13:06:30  keil
 * Apply most changes from 2.1.X (HiSax 3.1)
 *
 * Revision 1.10.2.9  1998/06/19 15:17:56  keil
 * fix LAPB tx_cnt for none I-frames
 *
 * Revision 1.10.2.8  1998/06/18 23:12:05  keil
 * LAPB bugfix
 *
 * Revision 1.10.2.7  1998/05/27 18:05:51  keil
 * HiSax 3.0
 *
 * Revision 1.10.2.6  1998/05/26 10:36:57  keil
 * fixes from certification
 *
 * Revision 1.10.2.5  1998/03/07 23:15:31  tsbogend
 * made HiSax working on Linux/Alpha
 *
 * Revision 1.10.2.4  1998/01/27 22:44:38  keil
 * fixed window size calculation
 *
 * Revision 1.10.2.3  1997/11/15 18:54:03  keil
 * cosmetics
 *
 * Revision 1.10.2.2  1997/10/17 22:13:59  keil
 * update to last hisax version
 *
 * Revision 2.2  1997/07/31 11:49:05  keil
 * Eroor handling for no TEI assign
 *
 * Revision 2.1  1997/07/27 21:34:38  keil
 * cosmetics
 *
 * Revision 2.0  1997/06/26 11:07:29  keil
 * New q.921 and X.75 Layer2
 *
 *
 *  Old log removed KKe
 *
 */
#define __NO_VERSION__
#include "hisax.h"
#include "isdnl2.h"

const char *l2_revision = "$Revision: 1.1.1.1 $";

static void l2m_debug(struct FsmInst *fi, char *fmt, ...);

static
struct Fsm l2fsm =
{NULL, 0, 0, NULL, NULL};

enum {
	ST_L2_1,
	ST_L2_2,
	ST_L2_3,
	ST_L2_4,
	ST_L2_5,
	ST_L2_6,
	ST_L2_7,
	ST_L2_8,
};

#define L2_STATE_COUNT (ST_L2_8+1)

static char *strL2State[] =
{
	"ST_L2_1",
	"ST_L2_2",
	"ST_L2_3",
	"ST_L2_4",
	"ST_L2_5",
	"ST_L2_6",
	"ST_L2_7",
	"ST_L2_8",
};

enum {
	EV_L2_UI,
	EV_L2_SABMX,
	EV_L2_DISC,
	EV_L2_DM,
	EV_L2_UA,
	EV_L2_FRMR,
	EV_L2_SUPER,
	EV_L2_I,
	EV_L2_DL_DATA,
	EV_L2_ACK_PULL,
	EV_L2_DL_UNIT_DATA,
	EV_L2_DL_ESTABLISH,
	EV_L2_DL_RELEASE,
	EV_L2_MDL_ASSIGN,
	EV_L2_MDL_REMOVE,
	EV_L2_MDL_ERROR,
	EV_L1_DEACTIVATE,
	EV_L2_T200,
	EV_L2_T203,
};

#define L2_EVENT_COUNT (EV_L2_T203+1)

static char *strL2Event[] =
{
	"EV_L2_UI",
	"EV_L2_SABMX",
	"EV_L2_DISC",
	"EV_L2_DM",
	"EV_L2_UA",
	"EV_L2_FRMR",
	"EV_L2_SUPER",
	"EV_L2_I",
	"EV_L2_DL_DATA",
	"EV_L2_ACK_PULL",
	"EV_L2_DL_UNIT_DATA",
	"EV_L2_DL_ESTABLISH",
	"EV_L2_DL_RELEASE",
	"EV_L2_MDL_ASSIGN",
	"EV_L2_MDL_REMOVE",
	"EV_L2_MDL_ERROR",
	"EV_L1_DEACTIVATE",
	"EV_L2_T200",
	"EV_L2_T203",
};

static int l2addrsize(struct Layer2 *l2);

static void
InitWin(struct Layer2 *l2)
{
	int i;

	for (i = 0; i < MAX_WINDOW; i++)
		l2->windowar[i] = NULL;
}

static void
ReleaseWin(struct Layer2 *l2)
{
	int i, cnt = 0;

	for (i = 0; i < MAX_WINDOW; i++) {
		if (l2->windowar[i]) {
			cnt++;
			dev_kfree_skb(l2->windowar[i], FREE_WRITE);
			l2->windowar[i] = NULL;
		}
	}
	if (cnt)
		printk(KERN_WARNING "isdl2 freed %d skbuffs in release\n", cnt);
}

inline int
cansend(struct PStack *st)
{
	int p1;

	p1 = st->l2.vs - st->l2.va;
	if (p1 < 0)
		p1 += (test_bit(FLG_MOD128, &st->l2.flag) ? 128 : 8);
	return ((p1 < st->l2.window) && !test_bit(FLG_PEER_BUSY, &st->l2.flag));
}

inline void
clear_exception(struct Layer2 *l2)
{
	test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
	test_and_clear_bit(FLG_REJEXC, &l2->flag);
	test_and_clear_bit(FLG_OWN_BUSY, &l2->flag);
	test_and_clear_bit(FLG_PEER_BUSY, &l2->flag);
}

inline int
l2headersize(struct Layer2 *l2, int ui)
{
	return (((test_bit(FLG_MOD128, &l2->flag) && (!ui)) ? 2 : 1) +
		(test_bit(FLG_LAPD, &l2->flag) ? 2 : 1));
}

inline int
l2addrsize(struct Layer2 *l2)
{
	return (test_bit(FLG_LAPD, &l2->flag) ? 2 : 1);
}

static int
sethdraddr(struct Layer2 *l2, u_char * header, int rsp)
{
	u_char *ptr = header;
	int crbit = rsp;

	if (test_bit(FLG_LAPD, &l2->flag)) {
		*ptr++ = (l2->sap << 2) | (rsp ? 2 : 0);
		*ptr++ = (l2->tei << 1) | 1;
		return (2);
	} else {
		if (test_bit(FLG_ORIG, &l2->flag))
			crbit = !crbit;
		if (crbit)
			*ptr++ = 1;
		else
			*ptr++ = 3;
		return (1);
	}
}

inline static void
enqueue_super(struct PStack *st,
	      struct sk_buff *skb)
{
	if (test_bit(FLG_LAPB, &st->l2.flag))
		st->l1.bcs->tx_cnt += skb->len;
	st->l2.l2l1(st, PH_DATA | REQUEST, skb);
}

#define enqueue_ui(a, b) enqueue_super(a, b)

inline int
IsUI(u_char * data, int ext)
{
	return ((data[0] & 0xef) == UI);
}

inline int
IsUA(u_char * data, int ext)
{
	return ((data[0] & 0xef) == UA);
}

inline int
IsDM(u_char * data, int ext)
{
	return ((data[0] & 0xef) == DM);
}

inline int
IsDISC(u_char * data, int ext)
{
	return ((data[0] & 0xef) == DISC);
}

inline int
IsRR(u_char * data, int ext)
{
	if (ext)
		return (data[0] == RR);
	else
		return ((data[0] & 0xf) == 1);
}

inline int
IsSFrame(u_char * data, int ext)
{
	register u_char d = *data;
	
	if (!ext)
		d &= 0xf;
	return(((d & 0xf3) == 1) && ((d & 0x0c) != 0x0c));
}

inline int
IsSABMX(u_char * data, int ext)
{
	u_char d = data[0] & ~0x10;

	return (ext ? d == SABME : d == SABM);
}

inline int
IsREJ(u_char * data, int ext)
{
	return (ext ? data[0] == REJ : (data[0] & 0xf) == REJ);
}

inline int
IsFRMR(u_char * data, int ext)
{
	return ((data[0] & 0xef) == FRMR);
}

inline int
IsRNR(u_char * data, int ext)
{
	return (ext ? data[0] == RNR : (data[0] & 0xf) == RNR);
}

static int
legalnr(struct PStack *st, int nr)
{
	struct Layer2 *l2 = &st->l2;
	int lnr, lvs;

	lvs = (l2->vs >= l2->va) ? l2->vs :
	    (l2->vs + (test_bit(FLG_MOD128, &l2->flag) ? 128 : 8));
	lnr = (nr >= l2->va) ? nr : (test_bit(FLG_MOD128, &l2->flag) ? 128 : 8);
	return (lnr <= lvs);
}

static void
setva(struct PStack *st, int nr)
{
	struct Layer2 *l2 = &st->l2;
	int len;

	while (l2->va != nr) {
		l2->va = (l2->va + 1) % (test_bit(FLG_MOD128, &l2->flag) ? 128 : 8);
		len = l2->windowar[l2->sow]->len;
		if (PACKET_NOACK == l2->windowar[l2->sow]->pkt_type)
			len = -1;
		dev_kfree_skb(l2->windowar[l2->sow], FREE_WRITE);
		l2->windowar[l2->sow] = NULL;
		l2->sow = (l2->sow + 1) % l2->window;
		if (st->lli.l2writewakeup && (len >=0))
			st->lli.l2writewakeup(st, len);
	}
}

static void
send_uframe(struct PStack *st, u_char cmd, u_char cr)
{
	struct sk_buff *skb;
	u_char tmp[MAX_HEADER_LEN];
	int i;

	i = sethdraddr(&st->l2, tmp, cr);
	tmp[i++] = cmd;
	if (!(skb = alloc_skb(i, GFP_ATOMIC))) {
		printk(KERN_WARNING "isdl2 can't alloc sbbuff for send_uframe\n");
		return;
	}
	SET_SKB_FREE(skb);
	memcpy(skb_put(skb, i), tmp, i);
	enqueue_super(st, skb);
}

inline u_char
get_PollFlag(struct PStack * st, struct sk_buff * skb)
{
	return (skb->data[l2addrsize(&(st->l2))] & 0x10);
}

inline void
FreeSkb(struct sk_buff *skb)
{
	dev_kfree_skb(skb, FREE_READ);
}


inline u_char
get_PollFlagFree(struct PStack *st, struct sk_buff *skb)
{
	u_char PF;

	PF = get_PollFlag(st, skb);
	FreeSkb(skb);
	return (PF);
}

static void
establishlink(struct FsmInst *fi)
{
	struct PStack *st = fi->userdata;
	u_char cmd;

	clear_exception(&st->l2);
	st->l2.rc = 0;
	cmd = (test_bit(FLG_MOD128, &st->l2.flag) ? SABME : SABM) | 0x10;
	send_uframe(st, cmd, CMD);
	FsmDelTimer(&st->l2.t203, 1);
	FsmRestartTimer(&st->l2.t200, st->l2.T200, EV_L2_T200, NULL, 1);
	test_and_set_bit(FLG_T200_RUN, &st->l2.flag);
	FsmChangeState(fi, ST_L2_5);
}

static void
l2_mdl_error(struct FsmInst *fi, int event, void *arg)
{
	struct sk_buff *skb = arg;
	struct PStack *st = fi->userdata;

	switch (event) {
		case EV_L2_UA:
			if (get_PollFlagFree(st, skb))
				st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'C');
			else
				st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'D');
			break;
		case EV_L2_DM:
			if (get_PollFlagFree(st, skb))
				st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'B');
			else {
				st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'E');
				establishlink(fi);
				test_and_clear_bit(FLG_L3_INIT, &st->l2.flag);
			}
			break;
	}
}

static void
l2_dl_establish(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;
	int state = fi->state;

	
	if (test_bit(FLG_FIXED_TEI, &st->l2.flag)) {
		FsmChangeState(fi, ST_L2_4);
		establishlink(fi);
		test_and_set_bit(FLG_L3_INIT, &st->l2.flag);
	} else {
		FsmChangeState(fi, ST_L2_3);
		if (state == ST_L2_1)
			st->l2.l2tei(st, MDL_ASSIGN | INDICATION, NULL);
	}
}

static void
l2_send_ui(struct PStack *st)
{
	struct sk_buff *skb;
	u_char header[MAX_HEADER_LEN];
	int i;

	i = sethdraddr(&(st->l2), header, CMD);
	header[i++] = UI;
	while ((skb = skb_dequeue(&st->l2.ui_queue))) {
		memcpy(skb_push(skb, i), header, i);
		enqueue_ui(st, skb);
	}
}

static void
l2_put_ui(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;
	struct sk_buff *skb = arg;

	skb_queue_tail(&st->l2.ui_queue, skb);
	if (fi->state == ST_L2_1) {
		FsmChangeState(fi, ST_L2_2);
		st->l2.l2tei(st, MDL_ASSIGN | INDICATION, NULL);
	}
	if (fi->state > ST_L2_3)
		l2_send_ui(st);
}

static void
l2_got_ui(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;
	struct sk_buff *skb = arg;

	skb_pull(skb, l2headersize(&st->l2, 1));
	if (skb->len > st->l2.maxlen) { 
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'O');
		FreeSkb(skb);
	} else
		st->l2.l2l3(st, DL_UNIT_DATA | INDICATION, skb);
}

static void
l2_establish(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;

	if (fi->state != ST_L2_4)
		discard_queue(&st->l2.i_queue);
	if (fi->state != ST_L2_5)
		establishlink(fi);
	test_and_set_bit(FLG_L3_INIT, &st->l2.flag);
}

static void
l2_dl_release(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;

	if (fi->state == ST_L2_4) {
		st->l2.l2l3(st, DL_RELEASE  | CONFIRM, NULL);
		return;
	} else if (fi->state == ST_L2_5) {
		test_and_set_bit(FLG_PEND_REL, &st->l2.flag);
		return;
	}
	discard_queue(&st->l2.i_queue);
	FsmChangeState(fi, ST_L2_6);
	st->l2.rc = 0;
	send_uframe(st, DISC | 0x10, CMD);
	FsmDelTimer(&st->l2.t203, 1);
	FsmRestartTimer(&st->l2.t200, st->l2.T200, EV_L2_T200, NULL, 2);
	test_and_set_bit(FLG_T200_RUN, &st->l2.flag);
}

static void
l2_got_SABMX(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;
	struct sk_buff *skb = arg;
	int est = 1, state, rsp;
	u_char PollFlag;

	state = fi->state;
	rsp = *skb->data & 0x2;
	if (test_bit(FLG_ORIG, &st->l2.flag))
		rsp = !rsp;
	if (rsp) {
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'L');
		FreeSkb(skb);
		if ((state == ST_L2_7) || (state == ST_L2_8))
			establishlink(fi);
		return;
	}	
	if (skb->len != (l2addrsize(&st->l2) + 1)) {
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'N');
		FreeSkb(skb);
		if ((state == ST_L2_7) || (state == ST_L2_8))
			establishlink(fi);
		return;
	}
	PollFlag = get_PollFlagFree(st, skb);
	if (ST_L2_6 == state) {
		send_uframe(st, DM | PollFlag, RSP);
		return;
	} else
		send_uframe(st, UA | PollFlag, RSP);
	if (ST_L2_5 == state)
		return;
	if (ST_L2_4 != state) {
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'F');
		if (st->l2.vs != st->l2.va) {