isdnl2.c

linux-2.6.15.6

/* $Id: isdnl2.c,v 2.30.2.4 2004/02/11 13:21:34 keil Exp $
 *
 * Author       Karsten Keil
 *              based on the teles driver from Jan den Ouden
 * Copyright    by Karsten Keil      <[e-mail]>
 * 
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 * For changes and modifications please read
 * Documentation/isdn/HiSax.cert
 *
 * Thanks to    Jan den Ouden
 *              Fritz Elfert
 *
 */

#include <linux/init.h>
#include "hisax.h"
#include "isdnl2.h"

const char *l2_revision = "$Revision: 2.30.2.4 $";

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

static struct Fsm l2fsm;

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_SABME,
	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_REQ,
	EV_L2_DL_RELEASE_REQ,
	EV_L2_MDL_ASSIGN,
	EV_L2_MDL_REMOVE,
	EV_L2_MDL_ERROR,
	EV_L1_DEACTIVATE,
	EV_L2_T200,
	EV_L2_T203,
	EV_L2_SET_OWN_BUSY,
	EV_L2_CLEAR_OWN_BUSY,
	EV_L2_FRAME_ERROR,
};

#define L2_EVENT_COUNT (EV_L2_FRAME_ERROR+1)

static char *strL2Event[] =
{
	"EV_L2_UI",
	"EV_L2_SABME",
	"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_REQ",
	"EV_L2_DL_RELEASE_REQ",
	"EV_L2_MDL_ASSIGN",
	"EV_L2_MDL_REMOVE",
	"EV_L2_MDL_ERROR",
	"EV_L1_DEACTIVATE",
	"EV_L2_T200",
	"EV_L2_T203",
	"EV_L2_SET_OWN_BUSY",
	"EV_L2_CLEAR_OWN_BUSY",
	"EV_L2_FRAME_ERROR",
};

static int l2addrsize(struct Layer2 *l2);

static void
set_peer_busy(struct Layer2 *l2) {
	test_and_set_bit(FLG_PEER_BUSY, &l2->flag);
	if (!skb_queue_empty(&l2->i_queue) ||
	    !skb_queue_empty(&l2->ui_queue))
		test_and_set_bit(FLG_L2BLOCK, &l2->flag);
}

static void
clear_peer_busy(struct Layer2 *l2) {
	if (test_and_clear_bit(FLG_PEER_BUSY, &l2->flag))
		test_and_clear_bit(FLG_L2BLOCK, &l2->flag);
}

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

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

static int
freewin1(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]);
			l2->windowar[i] = NULL;
		}
	}
	return cnt;
}

static inline void
freewin(struct PStack *st)
{
	freewin1(&st->l2);
}

static void
ReleaseWin(struct Layer2 *l2)
{
	int cnt;

	if((cnt = freewin1(l2)))
		printk(KERN_WARNING "isdl2 freed %d skbuffs in release\n", cnt);
}

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

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

static 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);
	clear_peer_busy(l2);
}

static 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);
	}
}

static inline 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)

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

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

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

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

static inline int
IsSFrame(u_char * data, struct PStack *st)
{
	register u_char d = *data;
	
	if (!test_bit(FLG_MOD128, &st->l2.flag))
		d &= 0xf;
	return(((d & 0xf3) == 1) && ((d & 0x0c) != 0x0c));
}

static inline int
IsSABME(u_char * data, struct PStack *st)
{
	u_char d = data[0] & ~0x10;

	return (test_bit(FLG_MOD128, &st->l2.flag) ? d == SABME : d == SABM);
}

static inline int
IsREJ(u_char * data, struct PStack *st)
{
	return (test_bit(FLG_MOD128, &st->l2.flag) ? data[0] == REJ : (data[0] & 0xf) == REJ);
}

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

static inline int
IsRNR(u_char * data, struct PStack *st)
{
	return (test_bit(FLG_MOD128, &st->l2.flag) ? data[0] == RNR : (data[0] & 0xf) == RNR);
}

static int
iframe_error(struct PStack *st, struct sk_buff *skb)
{
	int i = l2addrsize(&st->l2) + (test_bit(FLG_MOD128, &st->l2.flag) ? 2 : 1);
	int rsp = *skb->data & 0x2;

	if (test_bit(FLG_ORIG, &st->l2.flag))
		rsp = !rsp;

	if (rsp)
		return 'L';


	if (skb->len < i)
		return 'N';

	if ((skb->len - i) > st->l2.maxlen)
		return 'O';


	return 0;
}

static int
super_error(struct PStack *st, struct sk_buff *skb)
{
	if (skb->len != l2addrsize(&st->l2) +
	    (test_bit(FLG_MOD128, &st->l2.flag) ? 2 : 1))
		return 'N';

	return 0;
}

static int
unnum_error(struct PStack *st, struct sk_buff *skb, int wantrsp)
{
	int rsp = (*skb->data & 0x2) >> 1;
	if (test_bit(FLG_ORIG, &st->l2.flag))
		rsp = !rsp;

	if (rsp != wantrsp)
		return 'L';

	if (skb->len != l2addrsize(&st->l2) + 1)
		return 'N';

	return 0;
}

static int
UI_error(struct PStack *st, struct sk_buff *skb)
{
	int rsp = *skb->data & 0x2;
	if (test_bit(FLG_ORIG, &st->l2.flag))
		rsp = !rsp;

	if (rsp)
		return 'L';

	if (skb->len > st->l2.maxlen + l2addrsize(&st->l2) + 1)
		return 'O';

	return 0;
}

static int
FRMR_error(struct PStack *st, struct sk_buff *skb)
{
	int headers = l2addrsize(&st->l2) + 1;
	u_char *datap = skb->data + headers;
	int rsp = *skb->data & 0x2;

	if (test_bit(FLG_ORIG, &st->l2.flag))
		rsp = !rsp;

	if (!rsp)
		return 'L';

	if (test_bit(FLG_MOD128, &st->l2.flag)) {
		if (skb->len < headers + 5)
			return 'N';
		else
			l2m_debug(&st->l2.l2m, "FRMR information %2x %2x %2x %2x %2x",
				datap[0], datap[1], datap[2],
				datap[3], datap[4]);
	} else {
		if (skb->len < headers + 3)
			return 'N';
		else
			l2m_debug(&st->l2.l2m, "FRMR information %2x %2x %2x",
				datap[0], datap[1], datap[2]);
	}

	return 0;
}

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

	if(test_bit(FLG_MOD128, &l2->flag))
		return ((nr - l2->va) % 128) <= ((l2->vs - l2->va) % 128);
	else
		return ((nr - l2->va) % 8) <= ((l2->vs - l2->va) % 8);
}

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

	spin_lock_irqsave(&l2->lock, flags);
	while (l2->va != nr) {
		(l2->va)++;
		if(test_bit(FLG_MOD128, &l2->flag))
			l2->va %= 128;
		else
			l2->va %= 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]);
		l2->windowar[l2->sow] = NULL;
		l2->sow = (l2->sow + 1) % l2->window;
		spin_unlock_irqrestore(&l2->lock, flags);
		if (test_bit(FLG_LLI_L2WAKEUP, &st->lli.flag) && (len >=0))
			lli_writewakeup(st, len);
		spin_lock_irqsave(&l2->lock, flags);
	}
	spin_unlock_irqrestore(&l2->lock, flags);
}

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;
	}
	memcpy(skb_put(skb, i), tmp, i);
	enqueue_super(st, skb);
}

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

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

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

static inline void
start_t200(struct PStack *st, int i)
{
	FsmAddTimer(&st->l2.t200, st->l2.T200, EV_L2_T200, NULL, i);
	test_and_set_bit(FLG_T200_RUN, &st->l2.flag);
}

static inline void
restart_t200(struct PStack *st, int i)
{
	FsmRestartTimer(&st->l2.t200, st->l2.T200, EV_L2_T200, NULL, i);
	test_and_set_bit(FLG_T200_RUN, &st->l2.flag);
}

static inline void
stop_t200(struct PStack *st, int i)
{
	if(test_and_clear_bit(FLG_T200_RUN, &st->l2.flag))
		FsmDelTimer(&st->l2.t200, i);
}

static inline void
st5_dl_release_l2l3(struct PStack *st)
{
		int pr;

		if(test_and_clear_bit(FLG_PEND_REL, &st->l2.flag))
			pr = DL_RELEASE | CONFIRM;
		else
			pr = DL_RELEASE | INDICATION;

		st->l2.l2l3(st, pr, NULL);
}

static inline void
lapb_dl_release_l2l3(struct PStack *st, int f)
{
		if (test_bit(FLG_LAPB, &st->l2.flag))
			st->l2.l2l1(st, PH_DEACTIVATE | REQUEST, NULL);
		st->l2.l2l3(st, DL_RELEASE | f, NULL);
}

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);
	restart_t200(st, 1);
	test_and_clear_bit(FLG_PEND_REL, &st->l2.flag);
	freewin(st);
	FsmChangeState(fi, ST_L2_5);
}

static void
l2_mdl_error_ua(struct FsmInst *fi, int event, void *arg)
{
	struct sk_buff *skb = arg;
	struct PStack *st = fi->userdata;

	if (get_PollFlagFree(st, skb))
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'C');
	else
		st->ma.layer(st, MDL_ERROR | INDICATION, (void *) 'D');
}

static void
l2_mdl_error_dm(struct FsmInst *fi, int event, void *arg)
{
	struct sk_buff *skb = arg;
	struct PStack *st = fi->userdata;

	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);
	}
}

static void
l2_st8_mdl_error_dm(struct FsmInst *fi, int event, void *arg)
{
	struct sk_buff *skb = arg;
	struct PStack *st = fi->userdata;

	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);
}

static void
l2_go_st3(struct FsmInst *fi, int event, void *arg)
{
	FsmChangeState(fi, ST_L2_3); 
}

static void
l2_mdl_assign(struct FsmInst *fi, int event, void *arg)
{
	struct PStack *st = fi->userdata;

	FsmChangeState(fi, ST_L2_3); 
	st->l2.l2tei(st, MDL_ASSIGN | INDICATION, NULL);
}

static void
l2_queue_ui_assign(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);
	FsmChangeState(fi, ST_L2_2);
	st->l2.l2tei(st, MDL_ASSIGN | INDICATION, NULL);
}

static void
l2_queue_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);
}

static void
tx_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_send_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);
	tx_ui(st);
}

static void