root/drivers/isdn/mISDN/layer2.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Author       Karsten Keil <kkeil@novell.com>
 *
 * Copyright 2008  by Karsten Keil <kkeil@novell.com>
 */

#include <linux/mISDNif.h>
#include <linux/slab.h>
#include "core.h"
#include "fsm.h"
#include "layer2.h"

static u_int *debug;

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

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_UNITDATA,
        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_T200I,
        EV_L2_T203I,
        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_UNITDATA",
        "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_T200I",
        "EV_L2_T203I",
        "EV_L2_SET_OWN_BUSY",
        "EV_L2_CLEAR_OWN_BUSY",
        "EV_L2_FRAME_ERROR",
};

static void
l2m_debug(struct FsmInst *fi, char *fmt, ...)
{
        struct layer2 *l2 = fi->userdata;
        struct va_format vaf;
        va_list va;

        if (!(*debug & DEBUG_L2_FSM))
                return;

        va_start(va, fmt);

        vaf.fmt = fmt;
        vaf.va = &va;

        printk(KERN_DEBUG "%s l2 (sapi %d tei %d): %pV\n",
               mISDNDevName4ch(&l2->ch), l2->sapi, l2->tei, &vaf);

        va_end(va);
}

inline u_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 u_int
l2addrsize(struct layer2 *l2)
{
        return test_bit(FLG_LAPD, &l2->flag) ? 2 : 1;
}

static u_int
l2_newid(struct layer2 *l2)
{
        u_int   id;

        id = l2->next_id++;
        if (id == 0x7fff)
                l2->next_id = 1;
        id <<= 16;
        id |= l2->tei << 8;
        id |= l2->sapi;
        return id;
}

static void
l2up(struct layer2 *l2, u_int prim, struct sk_buff *skb)
{
        int     err;

        if (!l2->up)
                return;
        mISDN_HEAD_PRIM(skb) = prim;
        mISDN_HEAD_ID(skb) = (l2->ch.nr << 16) | l2->ch.addr;
        err = l2->up->send(l2->up, skb);
        if (err) {
                printk(KERN_WARNING "%s: dev %s err=%d\n", __func__,
                       mISDNDevName4ch(&l2->ch), err);
                dev_kfree_skb(skb);
        }
}

static void
l2up_create(struct layer2 *l2, u_int prim, int len, void *arg)
{
        struct sk_buff  *skb;
        struct mISDNhead *hh;
        int             err;

        if (!l2->up)
                return;
        skb = mI_alloc_skb(len, GFP_ATOMIC);
        if (!skb)
                return;
        hh = mISDN_HEAD_P(skb);
        hh->prim = prim;
        hh->id = (l2->ch.nr << 16) | l2->ch.addr;
        if (len)
                skb_put_data(skb, arg, len);
        err = l2->up->send(l2->up, skb);
        if (err) {
                printk(KERN_WARNING "%s: dev %s err=%d\n", __func__,
                       mISDNDevName4ch(&l2->ch), err);
                dev_kfree_skb(skb);
        }
}

static int
l2down_skb(struct layer2 *l2, struct sk_buff *skb) {
        int ret;

        ret = l2->ch.recv(l2->ch.peer, skb);
        if (ret && (*debug & DEBUG_L2_RECV))
                printk(KERN_DEBUG "l2down_skb: dev %s ret(%d)\n",
                       mISDNDevName4ch(&l2->ch), ret);
        return ret;
}

static int
l2down_raw(struct layer2 *l2, struct sk_buff *skb)
{
        struct mISDNhead *hh = mISDN_HEAD_P(skb);

        if (hh->prim == PH_DATA_REQ) {
                if (test_and_set_bit(FLG_L1_NOTREADY, &l2->flag)) {
                        skb_queue_tail(&l2->down_queue, skb);
                        return 0;
                }
                l2->down_id = mISDN_HEAD_ID(skb);
        }
        return l2down_skb(l2, skb);
}

static int
l2down(struct layer2 *l2, u_int prim, u_int id, struct sk_buff *skb)
{
        struct mISDNhead *hh = mISDN_HEAD_P(skb);

        hh->prim = prim;
        hh->id = id;
        return l2down_raw(l2, skb);
}

static int
l2down_create(struct layer2 *l2, u_int prim, u_int id, int len, void *arg)
{
        struct sk_buff  *skb;
        int             err;
        struct mISDNhead *hh;

        skb = mI_alloc_skb(len, GFP_ATOMIC);
        if (!skb)
                return -ENOMEM;
        hh = mISDN_HEAD_P(skb);
        hh->prim = prim;
        hh->id = id;
        if (len)
                skb_put_data(skb, arg, len);
        err = l2down_raw(l2, skb);
        if (err)
                dev_kfree_skb(skb);
        return err;
}

static int
ph_data_confirm(struct layer2 *l2, struct mISDNhead *hh, struct sk_buff *skb) {
        struct sk_buff *nskb = skb;
        int ret = -EAGAIN;

        if (test_bit(FLG_L1_NOTREADY, &l2->flag)) {
                if (hh->id == l2->down_id) {
                        nskb = skb_dequeue(&l2->down_queue);
                        if (nskb) {
                                l2->down_id = mISDN_HEAD_ID(nskb);
                                if (l2down_skb(l2, nskb)) {
                                        dev_kfree_skb(nskb);
                                        l2->down_id = MISDN_ID_NONE;
                                }
                        } else
                                l2->down_id = MISDN_ID_NONE;
                        if (ret) {
                                dev_kfree_skb(skb);
                                ret = 0;
                        }
                        if (l2->down_id == MISDN_ID_NONE) {
                                test_and_clear_bit(FLG_L1_NOTREADY, &l2->flag);
                                mISDN_FsmEvent(&l2->l2m, EV_L2_ACK_PULL, NULL);
                        }
                }
        }
        if (!test_and_set_bit(FLG_L1_NOTREADY, &l2->flag)) {
                nskb = skb_dequeue(&l2->down_queue);
                if (nskb) {
                        l2->down_id = mISDN_HEAD_ID(nskb);
                        if (l2down_skb(l2, nskb)) {
                                dev_kfree_skb(nskb);
                                l2->down_id = MISDN_ID_NONE;
                                test_and_clear_bit(FLG_L1_NOTREADY, &l2->flag);
                        }
                } else
                        test_and_clear_bit(FLG_L1_NOTREADY, &l2->flag);
        }
        return ret;
}

static void
l2_timeout(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb;
        struct mISDNhead *hh;

        skb = mI_alloc_skb(0, GFP_ATOMIC);
        if (!skb) {
                printk(KERN_WARNING "%s: L2(%d,%d) nr:%x timer %s no skb\n",
                       mISDNDevName4ch(&l2->ch), l2->sapi, l2->tei,
                       l2->ch.nr, event == EV_L2_T200 ? "T200" : "T203");
                return;
        }
        hh = mISDN_HEAD_P(skb);
        hh->prim = event == EV_L2_T200 ? DL_TIMER200_IND : DL_TIMER203_IND;
        hh->id = l2->ch.nr;
        if (*debug & DEBUG_TIMER)
                printk(KERN_DEBUG "%s: L2(%d,%d) nr:%x timer %s expired\n",
                       mISDNDevName4ch(&l2->ch), l2->sapi, l2->tei,
                       l2->ch.nr, event == EV_L2_T200 ? "T200" : "T203");
        if (l2->ch.st)
                l2->ch.st->own.recv(&l2->ch.st->own, skb);
}

static int
l2mgr(struct layer2 *l2, u_int prim, void *arg) {
        long c = (long)arg;

        printk(KERN_WARNING "l2mgr: dev %s addr:%x prim %x %c\n",
               mISDNDevName4ch(&l2->ch), l2->id, prim, (char)c);
        if (test_bit(FLG_LAPD, &l2->flag) &&
            !test_bit(FLG_FIXED_TEI, &l2->flag)) {
                switch (c) {
                case 'C':
                case 'D':
                case 'G':
                case 'H':
                        l2_tei(l2, prim, (u_long)arg);
                        break;
                }
        }
        return 0;
}

static void
set_peer_busy(struct layer2 *l2) {
        test_and_set_bit(FLG_PEER_BUSY, &l2->flag);
        if (skb_queue_len(&l2->i_queue) || skb_queue_len(&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
freewin(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 void
ReleaseWin(struct layer2 *l2)
{
        int cnt = freewin(l2);

        if (cnt)
                printk(KERN_WARNING
                       "isdnl2 freed %d skbuffs in release\n", cnt);
}

inline unsigned int
cansend(struct layer2 *l2)
{
        unsigned int p1;

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

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)) {
                if (test_bit(FLG_LAPD_NET, &l2->flag))
                        crbit = !crbit;
                *ptr++ = (l2->sapi << 2) | (crbit ? 2 : 0);
                *ptr++ = (l2->tei << 1) | 1;
                return 2;
        } else {
                if (test_bit(FLG_ORIG, &l2->flag))
                        crbit = !crbit;
                if (crbit)
                        *ptr++ = l2->addr.B;
                else
                        *ptr++ = l2->addr.A;
                return 1;
        }
}

static inline void
enqueue_super(struct layer2 *l2, struct sk_buff *skb)
{
        if (l2down(l2, PH_DATA_REQ, l2_newid(l2), skb))
                dev_kfree_skb(skb);
}

static inline void
enqueue_ui(struct layer2 *l2, struct sk_buff *skb)
{
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_UI_IND, 0);
        if (l2down(l2, PH_DATA_REQ, l2_newid(l2), skb))
                dev_kfree_skb(skb);
}

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

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

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

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

inline int
IsRR(u_char *data, struct layer2 *l2)
{
        if (test_bit(FLG_MOD128, &l2->flag))
                return data[0] == RR;
        else
                return (data[0] & 0xf) == 1;
}

inline int
IsSFrame(u_char *data, struct layer2 *l2)
{
        register u_char d = *data;

        if (!test_bit(FLG_MOD128, &l2->flag))
                d &= 0xf;
        return ((d & 0xf3) == 1) && ((d & 0x0c) != 0x0c);
}

inline int
IsSABME(u_char *data, struct layer2 *l2)
{
        u_char d = data[0] & ~0x10;

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

inline int
IsREJ(u_char *data, struct layer2 *l2)
{
        return test_bit(FLG_MOD128, &l2->flag) ?
                data[0] == REJ : (data[0] & 0xf) == REJ;
}

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

inline int
IsRNR(u_char *data, struct layer2 *l2)
{
        return test_bit(FLG_MOD128, &l2->flag) ?
                data[0] == RNR : (data[0] & 0xf) == RNR;
}

static int
iframe_error(struct layer2 *l2, struct sk_buff *skb)
{
        u_int   i;
        int     rsp = *skb->data & 0x2;

        i = l2addrsize(l2) + (test_bit(FLG_MOD128, &l2->flag) ? 2 : 1);
        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;
        if (rsp)
                return 'L';
        if (skb->len < i)
                return 'N';
        if ((skb->len - i) > l2->maxlen)
                return 'O';
        return 0;
}

static int
super_error(struct layer2 *l2, struct sk_buff *skb)
{
        if (skb->len != l2addrsize(l2) +
            (test_bit(FLG_MOD128, &l2->flag) ? 2 : 1))
                return 'N';
        return 0;
}

static int
unnum_error(struct layer2 *l2, struct sk_buff *skb, int wantrsp)
{
        int rsp = (*skb->data & 0x2) >> 1;
        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;
        if (rsp != wantrsp)
                return 'L';
        if (skb->len != l2addrsize(l2) + 1)
                return 'N';
        return 0;
}

static int
UI_error(struct layer2 *l2, struct sk_buff *skb)
{
        int rsp = *skb->data & 0x2;
        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;
        if (rsp)
                return 'L';
        if (skb->len > l2->maxlen + l2addrsize(l2) + 1)
                return 'O';
        return 0;
}

static int
FRMR_error(struct layer2 *l2, struct sk_buff *skb)
{
        u_int   headers = l2addrsize(l2) + 1;
        u_char  *datap = skb->data + headers;
        int     rsp = *skb->data & 0x2;

        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;
        if (!rsp)
                return 'L';
        if (test_bit(FLG_MOD128, &l2->flag)) {
                if (skb->len < headers + 5)
                        return 'N';
                else if (*debug & DEBUG_L2)
                        l2m_debug(&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 if (*debug & DEBUG_L2)
                        l2m_debug(&l2->l2m,
                                  "FRMR information %2x %2x %2x",
                                  datap[0], datap[1], datap[2]);
        }
        return 0;
}

static unsigned int
legalnr(struct layer2 *l2, unsigned int nr)
{
        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 layer2 *l2, unsigned int nr)
{
        struct sk_buff  *skb;

        while (l2->va != nr) {
                l2->va++;
                if (test_bit(FLG_MOD128, &l2->flag))
                        l2->va %= 128;
                else
                        l2->va %= 8;
                if (l2->windowar[l2->sow]) {
                        skb_trim(l2->windowar[l2->sow], 0);
                        skb_queue_tail(&l2->tmp_queue, l2->windowar[l2->sow]);
                        l2->windowar[l2->sow] = NULL;
                }
                l2->sow = (l2->sow + 1) % l2->window;
        }
        skb = skb_dequeue(&l2->tmp_queue);
        while (skb) {
                dev_kfree_skb(skb);
                skb = skb_dequeue(&l2->tmp_queue);
        }
}

static void
send_uframe(struct layer2 *l2, struct sk_buff *skb, u_char cmd, u_char cr)
{
        u_char tmp[MAX_L2HEADER_LEN];
        int i;

        i = sethdraddr(l2, tmp, cr);
        tmp[i++] = cmd;
        if (skb)
                skb_trim(skb, 0);
        else {
                skb = mI_alloc_skb(i, GFP_ATOMIC);
                if (!skb) {
                        printk(KERN_WARNING "%s: can't alloc skbuff in %s\n",
                               mISDNDevName4ch(&l2->ch), __func__);
                        return;
                }
        }
        skb_put_data(skb, tmp, i);
        enqueue_super(l2, skb);
}


inline u_char
get_PollFlag(struct layer2 *l2, struct sk_buff *skb)
{
        return skb->data[l2addrsize(l2)] & 0x10;
}

inline u_char
get_PollFlagFree(struct layer2 *l2, struct sk_buff *skb)
{
        u_char PF;

        PF = get_PollFlag(l2, skb);
        dev_kfree_skb(skb);
        return PF;
}

inline void
start_t200(struct layer2 *l2, int i)
{
        mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, i);
        test_and_set_bit(FLG_T200_RUN, &l2->flag);
}

inline void
restart_t200(struct layer2 *l2, int i)
{
        mISDN_FsmRestartTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, i);
        test_and_set_bit(FLG_T200_RUN, &l2->flag);
}

inline void
stop_t200(struct layer2 *l2, int i)
{
        if (test_and_clear_bit(FLG_T200_RUN, &l2->flag))
                mISDN_FsmDelTimer(&l2->t200, i);
}

inline void
st5_dl_release_l2l3(struct layer2 *l2)
{
        int pr;

        if (test_and_clear_bit(FLG_PEND_REL, &l2->flag))
                pr = DL_RELEASE_CNF;
        else
                pr = DL_RELEASE_IND;
        l2up_create(l2, pr, 0, NULL);
}

inline void
lapb_dl_release_l2l3(struct layer2 *l2, int f)
{
        if (test_bit(FLG_LAPB, &l2->flag))
                l2down_create(l2, PH_DEACTIVATE_REQ, l2_newid(l2), 0, NULL);
        l2up_create(l2, f, 0, NULL);
}

static void
establishlink(struct FsmInst *fi)
{
        struct layer2 *l2 = fi->userdata;
        u_char cmd;

        clear_exception(l2);
        l2->rc = 0;
        cmd = (test_bit(FLG_MOD128, &l2->flag) ? SABME : SABM) | 0x10;
        send_uframe(l2, NULL, cmd, CMD);
        mISDN_FsmDelTimer(&l2->t203, 1);
        restart_t200(l2, 1);
        test_and_clear_bit(FLG_PEND_REL, &l2->flag);
        freewin(l2);
        mISDN_FsmChangeState(fi, ST_L2_5);
}

static void
l2_mdl_error_ua(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        if (get_PollFlagFree(l2, skb))
                l2mgr(l2, MDL_ERROR_IND, (void *) 'C');
        else
                l2mgr(l2, MDL_ERROR_IND, (void *) 'D');

}

static void
l2_mdl_error_dm(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        if (get_PollFlagFree(l2, skb))
                l2mgr(l2, MDL_ERROR_IND, (void *) 'B');
        else {
                l2mgr(l2, MDL_ERROR_IND, (void *) 'E');
                establishlink(fi);
                test_and_clear_bit(FLG_L3_INIT, &l2->flag);
        }
}

static void
l2_st8_mdl_error_dm(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        if (get_PollFlagFree(l2, skb))
                l2mgr(l2, MDL_ERROR_IND, (void *) 'B');
        else
                l2mgr(l2, MDL_ERROR_IND, (void *) 'E');
        establishlink(fi);
        test_and_clear_bit(FLG_L3_INIT, &l2->flag);
}

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

static void
l2_mdl_assign(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;

        mISDN_FsmChangeState(fi, ST_L2_3);
        dev_kfree_skb((struct sk_buff *)arg);
        l2_tei(l2, MDL_ASSIGN_IND, 0);
}

static void
l2_queue_ui_assign(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_tail(&l2->ui_queue, skb);
        mISDN_FsmChangeState(fi, ST_L2_2);
        l2_tei(l2, MDL_ASSIGN_IND, 0);
}

static void
l2_queue_ui(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_tail(&l2->ui_queue, skb);
}

static void
tx_ui(struct layer2 *l2)
{
        struct sk_buff *skb;
        u_char header[MAX_L2HEADER_LEN];
        int i;

        i = sethdraddr(l2, header, CMD);
        if (test_bit(FLG_LAPD_NET, &l2->flag))
                header[1] = 0xff; /* tei 127 */
        header[i++] = UI;
        while ((skb = skb_dequeue(&l2->ui_queue))) {
                memcpy(skb_push(skb, i), header, i);
                enqueue_ui(l2, skb);
        }
}

static void
l2_send_ui(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_tail(&l2->ui_queue, skb);
        tx_ui(l2);
}

static void
l2_got_ui(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_pull(skb, l2headersize(l2, 1));
/*
 *              in states 1-3 for broadcast
 */

        if (l2->tm)
                l2_tei(l2, MDL_STATUS_UI_IND, 0);
        l2up(l2, DL_UNITDATA_IND, skb);
}

static void
l2_establish(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        establishlink(fi);
        test_and_set_bit(FLG_L3_INIT, &l2->flag);
        dev_kfree_skb(skb);
}

static void
l2_discard_i_setl3(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->i_queue);
        test_and_set_bit(FLG_L3_INIT, &l2->flag);
        test_and_clear_bit(FLG_PEND_REL, &l2->flag);
        dev_kfree_skb(skb);
}

static void
l2_l3_reestablish(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->i_queue);
        establishlink(fi);
        test_and_set_bit(FLG_L3_INIT, &l2->flag);
        dev_kfree_skb(skb);
}

static void
l2_release(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_trim(skb, 0);
        l2up(l2, DL_RELEASE_CNF, skb);
}

static void
l2_pend_rel(struct FsmInst *fi, int event, void *arg)
{
        struct sk_buff *skb = arg;
        struct layer2 *l2 = fi->userdata;

        test_and_set_bit(FLG_PEND_REL, &l2->flag);
        dev_kfree_skb(skb);
}

static void
l2_disconnect(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_purge(&l2->i_queue);
        freewin(l2);
        mISDN_FsmChangeState(fi, ST_L2_6);
        l2->rc = 0;
        send_uframe(l2, NULL, DISC | 0x10, CMD);
        mISDN_FsmDelTimer(&l2->t203, 1);
        restart_t200(l2, 2);
        dev_kfree_skb(skb);
}

static void
l2_start_multi(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb = arg;

        l2->vs = 0;
        l2->va = 0;
        l2->vr = 0;
        l2->sow = 0;
        clear_exception(l2);
        send_uframe(l2, NULL, UA | get_PollFlag(l2, skb), RSP);
        mISDN_FsmChangeState(fi, ST_L2_7);
        mISDN_FsmAddTimer(&l2->t203, l2->T203, EV_L2_T203, NULL, 3);
        skb_trim(skb, 0);
        l2up(l2, DL_ESTABLISH_IND, skb);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_UP_IND, 0);
}

static void
l2_send_UA(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        send_uframe(l2, skb, UA | get_PollFlag(l2, skb), RSP);
}

static void
l2_send_DM(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        send_uframe(l2, skb, DM | get_PollFlag(l2, skb), RSP);
}

static void
l2_restart_multi(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb = arg;
        int             est = 0;

        send_uframe(l2, skb, UA | get_PollFlag(l2, skb), RSP);

        l2mgr(l2, MDL_ERROR_IND, (void *) 'F');

        if (l2->vs != l2->va) {
                skb_queue_purge(&l2->i_queue);
                est = 1;
        }

        clear_exception(l2);
        l2->vs = 0;
        l2->va = 0;
        l2->vr = 0;
        l2->sow = 0;
        mISDN_FsmChangeState(fi, ST_L2_7);
        stop_t200(l2, 3);
        mISDN_FsmRestartTimer(&l2->t203, l2->T203, EV_L2_T203, NULL, 3);

        if (est)
                l2up_create(l2, DL_ESTABLISH_IND, 0, NULL);
/*              mISDN_queue_data(&l2->inst, l2->inst.id | MSG_BROADCAST,
 *                  MGR_SHORTSTATUS | INDICATION, SSTATUS_L2_ESTABLISHED,
 *                  0, NULL, 0);
 */
        if (skb_queue_len(&l2->i_queue) && cansend(l2))
                mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);
}

static void
l2_stop_multi(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb = arg;

        mISDN_FsmChangeState(fi, ST_L2_4);
        mISDN_FsmDelTimer(&l2->t203, 3);
        stop_t200(l2, 4);

        send_uframe(l2, skb, UA | get_PollFlag(l2, skb), RSP);
        skb_queue_purge(&l2->i_queue);
        freewin(l2);
        lapb_dl_release_l2l3(l2, DL_RELEASE_IND);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
}

static void
l2_connected(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb = arg;
        int pr = -1;

        if (!get_PollFlag(l2, skb)) {
                l2_mdl_error_ua(fi, event, arg);
                return;
        }
        dev_kfree_skb(skb);
        if (test_and_clear_bit(FLG_PEND_REL, &l2->flag))
                l2_disconnect(fi, event, NULL);
        if (test_and_clear_bit(FLG_L3_INIT, &l2->flag)) {
                pr = DL_ESTABLISH_CNF;
        } else if (l2->vs != l2->va) {
                skb_queue_purge(&l2->i_queue);
                pr = DL_ESTABLISH_IND;
        }
        stop_t200(l2, 5);
        l2->vr = 0;
        l2->vs = 0;
        l2->va = 0;
        l2->sow = 0;
        mISDN_FsmChangeState(fi, ST_L2_7);
        mISDN_FsmAddTimer(&l2->t203, l2->T203, EV_L2_T203, NULL, 4);
        if (pr != -1)
                l2up_create(l2, pr, 0, NULL);

        if (skb_queue_len(&l2->i_queue) && cansend(l2))
                mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);

        if (l2->tm)
                l2_tei(l2, MDL_STATUS_UP_IND, 0);
}

static void
l2_released(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (!get_PollFlag(l2, skb)) {
                l2_mdl_error_ua(fi, event, arg);
                return;
        }
        dev_kfree_skb(skb);
        stop_t200(l2, 6);
        lapb_dl_release_l2l3(l2, DL_RELEASE_CNF);
        mISDN_FsmChangeState(fi, ST_L2_4);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
}

static void
l2_reestablish(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (!get_PollFlagFree(l2, skb)) {
                establishlink(fi);
                test_and_set_bit(FLG_L3_INIT, &l2->flag);
        }
}

static void
l2_st5_dm_release(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (get_PollFlagFree(l2, skb)) {
                stop_t200(l2, 7);
                if (!test_bit(FLG_L3_INIT, &l2->flag))
                        skb_queue_purge(&l2->i_queue);
                if (test_bit(FLG_LAPB, &l2->flag))
                        l2down_create(l2, PH_DEACTIVATE_REQ,
                                      l2_newid(l2), 0, NULL);
                st5_dl_release_l2l3(l2);
                mISDN_FsmChangeState(fi, ST_L2_4);
                if (l2->tm)
                        l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
        }
}

static void
l2_st6_dm_release(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (get_PollFlagFree(l2, skb)) {
                stop_t200(l2, 8);
                lapb_dl_release_l2l3(l2, DL_RELEASE_CNF);
                mISDN_FsmChangeState(fi, ST_L2_4);
                if (l2->tm)
                        l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
        }
}

static void
enquiry_cr(struct layer2 *l2, u_char typ, u_char cr, u_char pf)
{
        struct sk_buff *skb;
        u_char tmp[MAX_L2HEADER_LEN];
        int i;

        i = sethdraddr(l2, tmp, cr);
        if (test_bit(FLG_MOD128, &l2->flag)) {
                tmp[i++] = typ;
                tmp[i++] = (l2->vr << 1) | (pf ? 1 : 0);
        } else
                tmp[i++] = (l2->vr << 5) | typ | (pf ? 0x10 : 0);
        skb = mI_alloc_skb(i, GFP_ATOMIC);
        if (!skb) {
                printk(KERN_WARNING "%s: isdnl2 can't alloc sbbuff in %s\n",
                       mISDNDevName4ch(&l2->ch), __func__);
                return;
        }
        skb_put_data(skb, tmp, i);
        enqueue_super(l2, skb);
}

inline void
enquiry_response(struct layer2 *l2)
{
        if (test_bit(FLG_OWN_BUSY, &l2->flag))
                enquiry_cr(l2, RNR, RSP, 1);
        else
                enquiry_cr(l2, RR, RSP, 1);
        test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
}

inline void
transmit_enquiry(struct layer2 *l2)
{
        if (test_bit(FLG_OWN_BUSY, &l2->flag))
                enquiry_cr(l2, RNR, CMD, 1);
        else
                enquiry_cr(l2, RR, CMD, 1);
        test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
        start_t200(l2, 9);
}


static void
nrerrorrecovery(struct FsmInst *fi)
{
        struct layer2 *l2 = fi->userdata;

        l2mgr(l2, MDL_ERROR_IND, (void *) 'J');
        establishlink(fi);
        test_and_clear_bit(FLG_L3_INIT, &l2->flag);
}

static void
invoke_retransmission(struct layer2 *l2, unsigned int nr)
{
        u_int   p1;

        if (l2->vs != nr) {
                while (l2->vs != nr) {
                        (l2->vs)--;
                        if (test_bit(FLG_MOD128, &l2->flag)) {
                                l2->vs %= 128;
                                p1 = (l2->vs - l2->va) % 128;
                        } else {
                                l2->vs %= 8;
                                p1 = (l2->vs - l2->va) % 8;
                        }
                        p1 = (p1 + l2->sow) % l2->window;
                        if (l2->windowar[p1])
                                skb_queue_head(&l2->i_queue, l2->windowar[p1]);
                        else
                                printk(KERN_WARNING
                                       "%s: windowar[%d] is NULL\n",
                                       mISDNDevName4ch(&l2->ch), p1);
                        l2->windowar[p1] = NULL;
                }
                mISDN_FsmEvent(&l2->l2m, EV_L2_ACK_PULL, NULL);
        }
}

static void
l2_st7_got_super(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;
        int PollFlag, rsp, typ = RR;
        unsigned int nr;

        rsp = *skb->data & 0x2;
        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;

        skb_pull(skb, l2addrsize(l2));
        if (IsRNR(skb->data, l2)) {
                set_peer_busy(l2);
                typ = RNR;
        } else
                clear_peer_busy(l2);
        if (IsREJ(skb->data, l2))
                typ = REJ;

        if (test_bit(FLG_MOD128, &l2->flag)) {
                PollFlag = (skb->data[1] & 0x1) == 0x1;
                nr = skb->data[1] >> 1;
        } else {
                PollFlag = (skb->data[0] & 0x10);
                nr = (skb->data[0] >> 5) & 0x7;
        }
        dev_kfree_skb(skb);

        if (PollFlag) {
                if (rsp)
                        l2mgr(l2, MDL_ERROR_IND, (void *) 'A');
                else
                        enquiry_response(l2);
        }
        if (legalnr(l2, nr)) {
                if (typ == REJ) {
                        setva(l2, nr);
                        invoke_retransmission(l2, nr);
                        stop_t200(l2, 10);
                        if (mISDN_FsmAddTimer(&l2->t203, l2->T203,
                                              EV_L2_T203, NULL, 6))
                                l2m_debug(&l2->l2m, "Restart T203 ST7 REJ");
                } else if ((nr == l2->vs) && (typ == RR)) {
                        setva(l2, nr);
                        stop_t200(l2, 11);
                        mISDN_FsmRestartTimer(&l2->t203, l2->T203,
                                              EV_L2_T203, NULL, 7);
                } else if ((l2->va != nr) || (typ == RNR)) {
                        setva(l2, nr);
                        if (typ != RR)
                                mISDN_FsmDelTimer(&l2->t203, 9);
                        restart_t200(l2, 12);
                }
                if (skb_queue_len(&l2->i_queue) && (typ == RR))
                        mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);
        } else
                nrerrorrecovery(fi);
}

static void
l2_feed_i_if_reest(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (!test_bit(FLG_L3_INIT, &l2->flag))
                skb_queue_tail(&l2->i_queue, skb);
        else
                dev_kfree_skb(skb);
}

static void
l2_feed_i_pull(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_tail(&l2->i_queue, skb);
        mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);
}

static void
l2_feed_iqueue(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_tail(&l2->i_queue, skb);
}

static void
l2_got_iframe(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb = arg;
        int             PollFlag, i;
        u_int           ns, nr;

        i = l2addrsize(l2);
        if (test_bit(FLG_MOD128, &l2->flag)) {
                PollFlag = ((skb->data[i + 1] & 0x1) == 0x1);
                ns = skb->data[i] >> 1;
                nr = (skb->data[i + 1] >> 1) & 0x7f;
        } else {
                PollFlag = (skb->data[i] & 0x10);
                ns = (skb->data[i] >> 1) & 0x7;
                nr = (skb->data[i] >> 5) & 0x7;
        }
        if (test_bit(FLG_OWN_BUSY, &l2->flag)) {
                dev_kfree_skb(skb);
                if (PollFlag)
                        enquiry_response(l2);
        } else {
                if (l2->vr == ns) {
                        l2->vr++;
                        if (test_bit(FLG_MOD128, &l2->flag))
                                l2->vr %= 128;
                        else
                                l2->vr %= 8;
                        test_and_clear_bit(FLG_REJEXC, &l2->flag);
                        if (PollFlag)
                                enquiry_response(l2);
                        else
                                test_and_set_bit(FLG_ACK_PEND, &l2->flag);
                        skb_pull(skb, l2headersize(l2, 0));
                        l2up(l2, DL_DATA_IND, skb);
                } else {
                        /* n(s)!=v(r) */
                        dev_kfree_skb(skb);
                        if (test_and_set_bit(FLG_REJEXC, &l2->flag)) {
                                if (PollFlag)
                                        enquiry_response(l2);
                        } else {
                                enquiry_cr(l2, REJ, RSP, PollFlag);
                                test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
                        }
                }
        }
        if (legalnr(l2, nr)) {
                if (!test_bit(FLG_PEER_BUSY, &l2->flag) &&
                    (fi->state == ST_L2_7)) {
                        if (nr == l2->vs) {
                                stop_t200(l2, 13);
                                mISDN_FsmRestartTimer(&l2->t203, l2->T203,
                                                      EV_L2_T203, NULL, 7);
                        } else if (nr != l2->va)
                                restart_t200(l2, 14);
                }
                setva(l2, nr);
        } else {
                nrerrorrecovery(fi);
                return;
        }
        if (skb_queue_len(&l2->i_queue) && (fi->state == ST_L2_7))
                mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);
        if (test_and_clear_bit(FLG_ACK_PEND, &l2->flag))
                enquiry_cr(l2, RR, RSP, 0);
}

static void
l2_got_tei(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        u_int           info;

        l2->tei = (signed char)(long)arg;
        set_channel_address(&l2->ch, l2->sapi, l2->tei);
        info = DL_INFO_L2_CONNECT;
        l2up_create(l2, DL_INFORMATION_IND, sizeof(info), &info);
        if (fi->state == ST_L2_3) {
                establishlink(fi);
                test_and_set_bit(FLG_L3_INIT, &l2->flag);
        } else
                mISDN_FsmChangeState(fi, ST_L2_4);
        if (skb_queue_len(&l2->ui_queue))
                tx_ui(l2);
}

static void
l2_st5_tout_200(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        if (test_bit(FLG_LAPD, &l2->flag) &&
            test_bit(FLG_DCHAN_BUSY, &l2->flag)) {
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 9);
        } else if (l2->rc == l2->N200) {
                mISDN_FsmChangeState(fi, ST_L2_4);
                test_and_clear_bit(FLG_T200_RUN, &l2->flag);
                skb_queue_purge(&l2->i_queue);
                l2mgr(l2, MDL_ERROR_IND, (void *) 'G');
                if (test_bit(FLG_LAPB, &l2->flag))
                        l2down_create(l2, PH_DEACTIVATE_REQ,
                                      l2_newid(l2), 0, NULL);
                st5_dl_release_l2l3(l2);
                if (l2->tm)
                        l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
        } else {
                l2->rc++;
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 9);
                send_uframe(l2, NULL, (test_bit(FLG_MOD128, &l2->flag) ?
                                       SABME : SABM) | 0x10, CMD);
        }
}

static void
l2_st6_tout_200(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        if (test_bit(FLG_LAPD, &l2->flag) &&
            test_bit(FLG_DCHAN_BUSY, &l2->flag)) {
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 9);
        } else if (l2->rc == l2->N200) {
                mISDN_FsmChangeState(fi, ST_L2_4);
                test_and_clear_bit(FLG_T200_RUN, &l2->flag);
                l2mgr(l2, MDL_ERROR_IND, (void *) 'H');
                lapb_dl_release_l2l3(l2, DL_RELEASE_CNF);
                if (l2->tm)
                        l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
        } else {
                l2->rc++;
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200,
                                  NULL, 9);
                send_uframe(l2, NULL, DISC | 0x10, CMD);
        }
}

static void
l2_st7_tout_200(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        if (test_bit(FLG_LAPD, &l2->flag) &&
            test_bit(FLG_DCHAN_BUSY, &l2->flag)) {
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 9);
                return;
        }
        test_and_clear_bit(FLG_T200_RUN, &l2->flag);
        l2->rc = 0;
        mISDN_FsmChangeState(fi, ST_L2_8);
        transmit_enquiry(l2);
        l2->rc++;
}

static void
l2_st8_tout_200(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        if (test_bit(FLG_LAPD, &l2->flag) &&
            test_bit(FLG_DCHAN_BUSY, &l2->flag)) {
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 9);
                return;
        }
        test_and_clear_bit(FLG_T200_RUN, &l2->flag);
        if (l2->rc == l2->N200) {
                l2mgr(l2, MDL_ERROR_IND, (void *) 'I');
                establishlink(fi);
                test_and_clear_bit(FLG_L3_INIT, &l2->flag);
        } else {
                transmit_enquiry(l2);
                l2->rc++;
        }
}

static void
l2_st7_tout_203(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        if (test_bit(FLG_LAPD, &l2->flag) &&
            test_bit(FLG_DCHAN_BUSY, &l2->flag)) {
                mISDN_FsmAddTimer(&l2->t203, l2->T203, EV_L2_T203, NULL, 9);
                return;
        }
        mISDN_FsmChangeState(fi, ST_L2_8);
        transmit_enquiry(l2);
        l2->rc = 0;
}

static void
l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
{
        struct layer2   *l2 = fi->userdata;
        struct sk_buff  *skb, *nskb;
        u_char          header[MAX_L2HEADER_LEN];
        u_int           i, p1;

        if (!cansend(l2))
                return;

        skb = skb_dequeue(&l2->i_queue);
        if (!skb)
                return;
        i = sethdraddr(l2, header, CMD);
        if (test_bit(FLG_MOD128, &l2->flag)) {
                header[i++] = l2->vs << 1;
                header[i++] = l2->vr << 1;
        } else
                header[i++] = (l2->vr << 5) | (l2->vs << 1);
        nskb = skb_realloc_headroom(skb, i);
        if (!nskb) {
                printk(KERN_WARNING "%s: no headroom(%d) copy for IFrame\n",
                       mISDNDevName4ch(&l2->ch), i);
                skb_queue_head(&l2->i_queue, skb);
                return;
        }
        if (test_bit(FLG_MOD128, &l2->flag)) {
                p1 = (l2->vs - l2->va) % 128;
                l2->vs = (l2->vs + 1) % 128;
        } else {
                p1 = (l2->vs - l2->va) % 8;
                l2->vs = (l2->vs + 1) % 8;
        }
        p1 = (p1 + l2->sow) % l2->window;
        if (l2->windowar[p1]) {
                printk(KERN_WARNING "%s: l2 try overwrite ack queue entry %d\n",
                       mISDNDevName4ch(&l2->ch), p1);
                dev_kfree_skb(l2->windowar[p1]);
        }
        l2->windowar[p1] = skb;
        memcpy(skb_push(nskb, i), header, i);
        l2down(l2, PH_DATA_REQ, l2_newid(l2), nskb);
        test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
        if (!test_and_set_bit(FLG_T200_RUN, &l2->flag)) {
                mISDN_FsmDelTimer(&l2->t203, 13);
                mISDN_FsmAddTimer(&l2->t200, l2->T200, EV_L2_T200, NULL, 11);
        }
}

static void
l2_st8_got_super(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;
        int PollFlag, rsp, rnr = 0;
        unsigned int nr;

        rsp = *skb->data & 0x2;
        if (test_bit(FLG_ORIG, &l2->flag))
                rsp = !rsp;

        skb_pull(skb, l2addrsize(l2));

        if (IsRNR(skb->data, l2)) {
                set_peer_busy(l2);
                rnr = 1;
        } else
                clear_peer_busy(l2);

        if (test_bit(FLG_MOD128, &l2->flag)) {
                PollFlag = (skb->data[1] & 0x1) == 0x1;
                nr = skb->data[1] >> 1;
        } else {
                PollFlag = (skb->data[0] & 0x10);
                nr = (skb->data[0] >> 5) & 0x7;
        }
        dev_kfree_skb(skb);
        if (rsp && PollFlag) {
                if (legalnr(l2, nr)) {
                        if (rnr) {
                                restart_t200(l2, 15);
                        } else {
                                stop_t200(l2, 16);
                                mISDN_FsmAddTimer(&l2->t203, l2->T203,
                                                  EV_L2_T203, NULL, 5);
                                setva(l2, nr);
                        }
                        invoke_retransmission(l2, nr);
                        mISDN_FsmChangeState(fi, ST_L2_7);
                        if (skb_queue_len(&l2->i_queue) && cansend(l2))
                                mISDN_FsmEvent(fi, EV_L2_ACK_PULL, NULL);
                } else
                        nrerrorrecovery(fi);
        } else {
                if (!rsp && PollFlag)
                        enquiry_response(l2);
                if (legalnr(l2, nr))
                        setva(l2, nr);
                else
                        nrerrorrecovery(fi);
        }
}

static void
l2_got_FRMR(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_pull(skb, l2addrsize(l2) + 1);

        if (!(skb->data[0] & 1) || ((skb->data[0] & 3) == 1) || /* I or S */
            (IsUA(skb->data) && (fi->state == ST_L2_7))) {
                l2mgr(l2, MDL_ERROR_IND, (void *) 'K');
                establishlink(fi);
                test_and_clear_bit(FLG_L3_INIT, &l2->flag);
        }
        dev_kfree_skb(skb);
}

static void
l2_st24_tei_remove(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->ui_queue);
        l2->tei = GROUP_TEI;
        mISDN_FsmChangeState(fi, ST_L2_1);
}

static void
l2_st3_tei_remove(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->ui_queue);
        l2->tei = GROUP_TEI;
        l2up_create(l2, DL_RELEASE_IND, 0, NULL);
        mISDN_FsmChangeState(fi, ST_L2_1);
}

static void
l2_st5_tei_remove(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        freewin(l2);
        l2->tei = GROUP_TEI;
        stop_t200(l2, 17);
        st5_dl_release_l2l3(l2);
        mISDN_FsmChangeState(fi, ST_L2_1);
}

static void
l2_st6_tei_remove(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->ui_queue);
        l2->tei = GROUP_TEI;
        stop_t200(l2, 18);
        l2up_create(l2, DL_RELEASE_IND, 0, NULL);
        mISDN_FsmChangeState(fi, ST_L2_1);
}

static void
l2_tei_remove(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        freewin(l2);
        l2->tei = GROUP_TEI;
        stop_t200(l2, 17);
        mISDN_FsmDelTimer(&l2->t203, 19);
        l2up_create(l2, DL_RELEASE_IND, 0, NULL);
/*      mISDN_queue_data(&l2->inst, l2->inst.id | MSG_BROADCAST,
 *              MGR_SHORTSTATUS_IND, SSTATUS_L2_RELEASED,
 *              0, NULL, 0);
 */
        mISDN_FsmChangeState(fi, ST_L2_1);
}

static void
l2_st14_persistent_da(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        if (test_and_clear_bit(FLG_ESTAB_PEND, &l2->flag))
                l2up(l2, DL_RELEASE_IND, skb);
        else
                dev_kfree_skb(skb);
}

static void
l2_st5_persistent_da(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        freewin(l2);
        stop_t200(l2, 19);
        st5_dl_release_l2l3(l2);
        mISDN_FsmChangeState(fi, ST_L2_4);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
        dev_kfree_skb(skb);
}

static void
l2_st6_persistent_da(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_purge(&l2->ui_queue);
        stop_t200(l2, 20);
        l2up(l2, DL_RELEASE_CNF, skb);
        mISDN_FsmChangeState(fi, ST_L2_4);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
}

static void
l2_persistent_da(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        freewin(l2);
        stop_t200(l2, 19);
        mISDN_FsmDelTimer(&l2->t203, 19);
        l2up(l2, DL_RELEASE_IND, skb);
        mISDN_FsmChangeState(fi, ST_L2_4);
        if (l2->tm)
                l2_tei(l2, MDL_STATUS_DOWN_IND, 0);
}

static void
l2_set_own_busy(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (!test_and_set_bit(FLG_OWN_BUSY, &l2->flag)) {
                enquiry_cr(l2, RNR, RSP, 0);
                test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
        }
        dev_kfree_skb(skb);
}

static void
l2_clear_own_busy(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;
        struct sk_buff *skb = arg;

        if (!test_and_clear_bit(FLG_OWN_BUSY, &l2->flag)) {
                enquiry_cr(l2, RR, RSP, 0);
                test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
        }
        dev_kfree_skb(skb);
}

static void
l2_frame_error(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        l2mgr(l2, MDL_ERROR_IND, arg);
}

static void
l2_frame_error_reest(struct FsmInst *fi, int event, void *arg)
{
        struct layer2 *l2 = fi->userdata;

        l2mgr(l2, MDL_ERROR_IND, arg);
        establishlink(fi);
        test_and_clear_bit(FLG_L3_INIT, &l2->flag);
}

static struct FsmNode L2FnList[] =
{
        {ST_L2_1, EV_L2_DL_ESTABLISH_REQ, l2_mdl_assign},
        {ST_L2_2, EV_L2_DL_ESTABLISH_REQ, l2_go_st3},
        {ST_L2_4, EV_L2_DL_ESTABLISH_REQ, l2_establish},
        {ST_L2_5, EV_L2_DL_ESTABLISH_REQ, l2_discard_i_setl3},
        {ST_L2_7, EV_L2_DL_ESTABLISH_REQ, l2_l3_reestablish},
        {ST_L2_8, EV_L2_DL_ESTABLISH_REQ, l2_l3_reestablish},
        {ST_L2_4, EV_L2_DL_RELEASE_REQ, l2_release},
        {ST_L2_5, EV_L2_DL_RELEASE_REQ, l2_pend_rel},
        {ST_L2_7, EV_L2_DL_RELEASE_REQ, l2_disconnect},
        {ST_L2_8, EV_L2_DL_RELEASE_REQ, l2_disconnect},
        {ST_L2_5, EV_L2_DL_DATA, l2_feed_i_if_reest},
        {ST_L2_7, EV_L2_DL_DATA, l2_feed_i_pull},
        {ST_L2_8, EV_L2_DL_DATA, l2_feed_iqueue},
        {ST_L2_1, EV_L2_DL_UNITDATA, l2_queue_ui_assign},
        {ST_L2_2, EV_L2_DL_UNITDATA, l2_queue_ui},
        {ST_L2_3, EV_L2_DL_UNITDATA, l2_queue_ui},
        {ST_L2_4, EV_L2_DL_UNITDATA, l2_send_ui},
        {ST_L2_5, EV_L2_DL_UNITDATA, l2_send_ui},
        {ST_L2_6, EV_L2_DL_UNITDATA, l2_send_ui},
        {ST_L2_7, EV_L2_DL_UNITDATA, l2_send_ui},
        {ST_L2_8, EV_L2_DL_UNITDATA, l2_send_ui},
        {ST_L2_1, EV_L2_MDL_ASSIGN, l2_got_tei},
        {ST_L2_2, EV_L2_MDL_ASSIGN, l2_got_tei},
        {ST_L2_3, EV_L2_MDL_ASSIGN, l2_got_tei},
        {ST_L2_2, EV_L2_MDL_ERROR, l2_st24_tei_remove},
        {ST_L2_3, EV_L2_MDL_ERROR, l2_st3_tei_remove},
        {ST_L2_4, EV_L2_MDL_REMOVE, l2_st24_tei_remove},
        {ST_L2_5, EV_L2_MDL_REMOVE, l2_st5_tei_remove},
        {ST_L2_6, EV_L2_MDL_REMOVE, l2_st6_tei_remove},
        {ST_L2_7, EV_L2_MDL_REMOVE, l2_tei_remove},
        {ST_L2_8, EV_L2_MDL_REMOVE, l2_tei_remove},
        {ST_L2_4, EV_L2_SABME, l2_start_multi},
        {ST_L2_5, EV_L2_SABME, l2_send_UA},
        {ST_L2_6, EV_L2_SABME, l2_send_DM},
        {ST_L2_7, EV_L2_SABME, l2_restart_multi},
        {ST_L2_8, EV_L2_SABME, l2_restart_multi},
        {ST_L2_4, EV_L2_DISC, l2_send_DM},
        {ST_L2_5, EV_L2_DISC, l2_send_DM},
        {ST_L2_6, EV_L2_DISC, l2_send_UA},
        {ST_L2_7, EV_L2_DISC, l2_stop_multi},
        {ST_L2_8, EV_L2_DISC, l2_stop_multi},
        {ST_L2_4, EV_L2_UA, l2_mdl_error_ua},
        {ST_L2_5, EV_L2_UA, l2_connected},
        {ST_L2_6, EV_L2_UA, l2_released},
        {ST_L2_7, EV_L2_UA, l2_mdl_error_ua},
        {ST_L2_8, EV_L2_UA, l2_mdl_error_ua},
        {ST_L2_4, EV_L2_DM, l2_reestablish},
        {ST_L2_5, EV_L2_DM, l2_st5_dm_release},
        {ST_L2_6, EV_L2_DM, l2_st6_dm_release},
        {ST_L2_7, EV_L2_DM, l2_mdl_error_dm},
        {ST_L2_8, EV_L2_DM, l2_st8_mdl_error_dm},
        {ST_L2_1, EV_L2_UI, l2_got_ui},
        {ST_L2_2, EV_L2_UI, l2_got_ui},
        {ST_L2_3, EV_L2_UI, l2_got_ui},
        {ST_L2_4, EV_L2_UI, l2_got_ui},
        {ST_L2_5, EV_L2_UI, l2_got_ui},
        {ST_L2_6, EV_L2_UI, l2_got_ui},
        {ST_L2_7, EV_L2_UI, l2_got_ui},
        {ST_L2_8, EV_L2_UI, l2_got_ui},
        {ST_L2_7, EV_L2_FRMR, l2_got_FRMR},
        {ST_L2_8, EV_L2_FRMR, l2_got_FRMR},
        {ST_L2_7, EV_L2_SUPER, l2_st7_got_super},
        {ST_L2_8, EV_L2_SUPER, l2_st8_got_super},
        {ST_L2_7, EV_L2_I, l2_got_iframe},
        {ST_L2_8, EV_L2_I, l2_got_iframe},
        {ST_L2_5, EV_L2_T200, l2_timeout},
        {ST_L2_6, EV_L2_T200, l2_timeout},
        {ST_L2_7, EV_L2_T200, l2_timeout},
        {ST_L2_8, EV_L2_T200, l2_timeout},
        {ST_L2_7, EV_L2_T203, l2_timeout},
        {ST_L2_5, EV_L2_T200I, l2_st5_tout_200},
        {ST_L2_6, EV_L2_T200I, l2_st6_tout_200},
        {ST_L2_7, EV_L2_T200I, l2_st7_tout_200},
        {ST_L2_8, EV_L2_T200I, l2_st8_tout_200},
        {ST_L2_7, EV_L2_T203I, l2_st7_tout_203},
        {ST_L2_7, EV_L2_ACK_PULL, l2_pull_iqueue},
        {ST_L2_7, EV_L2_SET_OWN_BUSY, l2_set_own_busy},
        {ST_L2_8, EV_L2_SET_OWN_BUSY, l2_set_own_busy},
        {ST_L2_7, EV_L2_CLEAR_OWN_BUSY, l2_clear_own_busy},
        {ST_L2_8, EV_L2_CLEAR_OWN_BUSY, l2_clear_own_busy},
        {ST_L2_4, EV_L2_FRAME_ERROR, l2_frame_error},
        {ST_L2_5, EV_L2_FRAME_ERROR, l2_frame_error},
        {ST_L2_6, EV_L2_FRAME_ERROR, l2_frame_error},
        {ST_L2_7, EV_L2_FRAME_ERROR, l2_frame_error_reest},
        {ST_L2_8, EV_L2_FRAME_ERROR, l2_frame_error_reest},
        {ST_L2_1, EV_L1_DEACTIVATE, l2_st14_persistent_da},
        {ST_L2_2, EV_L1_DEACTIVATE, l2_st24_tei_remove},
        {ST_L2_3, EV_L1_DEACTIVATE, l2_st3_tei_remove},
        {ST_L2_4, EV_L1_DEACTIVATE, l2_st14_persistent_da},
        {ST_L2_5, EV_L1_DEACTIVATE, l2_st5_persistent_da},
        {ST_L2_6, EV_L1_DEACTIVATE, l2_st6_persistent_da},
        {ST_L2_7, EV_L1_DEACTIVATE, l2_persistent_da},
        {ST_L2_8, EV_L1_DEACTIVATE, l2_persistent_da},
};

static int
ph_data_indication(struct layer2 *l2, struct mISDNhead *hh, struct sk_buff *skb)
{
        u_char  *datap = skb->data;
        int     ret = -EINVAL;
        int     psapi, ptei;
        u_int   l;
        int     c = 0;

        l = l2addrsize(l2);
        if (skb->len <= l) {
                mISDN_FsmEvent(&l2->l2m, EV_L2_FRAME_ERROR, (void *) 'N');
                return ret;
        }
        if (test_bit(FLG_LAPD, &l2->flag)) { /* Maybe not needed */
                psapi = *datap++;
                ptei = *datap++;
                if ((psapi & 1) || !(ptei & 1)) {
                        printk(KERN_WARNING
                               "%s l2 D-channel frame wrong EA0/EA1\n",
                               mISDNDevName4ch(&l2->ch));
                        return ret;
                }
                psapi >>= 2;
                ptei >>= 1;
                if (psapi != l2->sapi) {
                        /* not our business */
                        if (*debug & DEBUG_L2)
                                printk(KERN_DEBUG "%s: sapi %d/%d mismatch\n",
                                       mISDNDevName4ch(&l2->ch), psapi,
                                       l2->sapi);
                        dev_kfree_skb(skb);
                        return 0;
                }
                if ((ptei != l2->tei) && (ptei != GROUP_TEI)) {
                        /* not our business */
                        if (*debug & DEBUG_L2)
                                printk(KERN_DEBUG "%s: tei %d/%d mismatch\n",
                                       mISDNDevName4ch(&l2->ch), ptei, l2->tei);
                        dev_kfree_skb(skb);
                        return 0;
                }
        } else
                datap += l;
        if (!(*datap & 1)) {    /* I-Frame */
                c = iframe_error(l2, skb);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_I, skb);
        } else if (IsSFrame(datap, l2)) {       /* S-Frame */
                c = super_error(l2, skb);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_SUPER, skb);
        } else if (IsUI(datap)) {
                c = UI_error(l2, skb);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_UI, skb);
        } else if (IsSABME(datap, l2)) {
                c = unnum_error(l2, skb, CMD);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_SABME, skb);
        } else if (IsUA(datap)) {
                c = unnum_error(l2, skb, RSP);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_UA, skb);
        } else if (IsDISC(datap)) {
                c = unnum_error(l2, skb, CMD);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DISC, skb);
        } else if (IsDM(datap)) {
                c = unnum_error(l2, skb, RSP);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DM, skb);
        } else if (IsFRMR(datap)) {
                c = FRMR_error(l2, skb);
                if (!c)
                        ret = mISDN_FsmEvent(&l2->l2m, EV_L2_FRMR, skb);
        } else
                c = 'L';
        if (c) {
                printk(KERN_WARNING "%s:l2 D-channel frame error %c\n",
                       mISDNDevName4ch(&l2->ch), c);
                mISDN_FsmEvent(&l2->l2m, EV_L2_FRAME_ERROR, (void *)(long)c);
        }
        return ret;
}

static int
l2_send(struct mISDNchannel *ch, struct sk_buff *skb)
{
        struct layer2           *l2 = container_of(ch, struct layer2, ch);
        struct mISDNhead        *hh =  mISDN_HEAD_P(skb);
        int                     ret = -EINVAL;

        if (*debug & DEBUG_L2_RECV)
                printk(KERN_DEBUG "%s: %s prim(%x) id(%x) sapi(%d) tei(%d)\n",
                       __func__, mISDNDevName4ch(&l2->ch), hh->prim, hh->id,
                       l2->sapi, l2->tei);
        if (hh->prim == DL_INTERN_MSG) {
                struct mISDNhead *chh = hh + 1; /* saved copy */

                *hh = *chh;
                if (*debug & DEBUG_L2_RECV)
                        printk(KERN_DEBUG "%s: prim(%x) id(%x) internal msg\n",
                                mISDNDevName4ch(&l2->ch), hh->prim, hh->id);
        }
        switch (hh->prim) {
        case PH_DATA_IND:
                ret = ph_data_indication(l2, hh, skb);
                break;
        case PH_DATA_CNF:
                ret = ph_data_confirm(l2, hh, skb);
                break;
        case PH_ACTIVATE_IND:
                test_and_set_bit(FLG_L1_ACTIV, &l2->flag);
                l2up_create(l2, MPH_ACTIVATE_IND, 0, NULL);
                if (test_and_clear_bit(FLG_ESTAB_PEND, &l2->flag))
                        ret = mISDN_FsmEvent(&l2->l2m,
                                             EV_L2_DL_ESTABLISH_REQ, skb);
                break;
        case PH_DEACTIVATE_IND:
                test_and_clear_bit(FLG_L1_ACTIV, &l2->flag);
                l2up_create(l2, MPH_DEACTIVATE_IND, 0, NULL);
                ret = mISDN_FsmEvent(&l2->l2m, EV_L1_DEACTIVATE, skb);
                break;
        case MPH_INFORMATION_IND:
                if (!l2->up)
                        break;
                ret = l2->up->send(l2->up, skb);
                break;
        case DL_DATA_REQ:
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DL_DATA, skb);
                break;
        case DL_UNITDATA_REQ:
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DL_UNITDATA, skb);
                break;
        case DL_ESTABLISH_REQ:
                if (test_bit(FLG_LAPB, &l2->flag))
                        test_and_set_bit(FLG_ORIG, &l2->flag);
                if (test_bit(FLG_L1_ACTIV, &l2->flag)) {
                        if (test_bit(FLG_LAPD, &l2->flag) ||
                            test_bit(FLG_ORIG, &l2->flag))
                                ret = mISDN_FsmEvent(&l2->l2m,
                                                     EV_L2_DL_ESTABLISH_REQ, skb);
                } else {
                        if (test_bit(FLG_LAPD, &l2->flag) ||
                            test_bit(FLG_ORIG, &l2->flag)) {
                                test_and_set_bit(FLG_ESTAB_PEND,
                                                 &l2->flag);
                        }
                        ret = l2down(l2, PH_ACTIVATE_REQ, l2_newid(l2),
                                     skb);
                }
                break;
        case DL_RELEASE_REQ:
                if (test_bit(FLG_LAPB, &l2->flag))
                        l2down_create(l2, PH_DEACTIVATE_REQ,
                                      l2_newid(l2), 0, NULL);
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_DL_RELEASE_REQ,
                                     skb);
                break;
        case DL_TIMER200_IND:
                mISDN_FsmEvent(&l2->l2m, EV_L2_T200I, NULL);
                break;
        case DL_TIMER203_IND:
                mISDN_FsmEvent(&l2->l2m, EV_L2_T203I, NULL);
                break;
        default:
                if (*debug & DEBUG_L2)
                        l2m_debug(&l2->l2m, "l2 unknown pr %04x",
                                  hh->prim);
        }
        if (ret) {
                dev_kfree_skb(skb);
                ret = 0;
        }
        return ret;
}

int
tei_l2(struct layer2 *l2, u_int cmd, u_long arg)
{
        int             ret = -EINVAL;

        if (*debug & DEBUG_L2_TEI)
                printk(KERN_DEBUG "%s: cmd(%x) in %s\n",
                       mISDNDevName4ch(&l2->ch), cmd, __func__);
        switch (cmd) {
        case (MDL_ASSIGN_REQ):
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_MDL_ASSIGN, (void *)arg);
                break;
        case (MDL_REMOVE_REQ):
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_MDL_REMOVE, NULL);
                break;
        case (MDL_ERROR_IND):
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_MDL_ERROR, NULL);
                break;
        case (MDL_ERROR_RSP):
                /* ETS 300-125 5.3.2.1 Test: TC13010 */
                printk(KERN_NOTICE "%s: MDL_ERROR|REQ (tei_l2)\n",
                       mISDNDevName4ch(&l2->ch));
                ret = mISDN_FsmEvent(&l2->l2m, EV_L2_MDL_ERROR, NULL);
                break;
        }
        return ret;
}

static void
release_l2(struct layer2 *l2)
{
        mISDN_FsmDelTimer(&l2->t200, 21);
        mISDN_FsmDelTimer(&l2->t203, 16);
        skb_queue_purge(&l2->i_queue);
        skb_queue_purge(&l2->ui_queue);
        skb_queue_purge(&l2->down_queue);
        ReleaseWin(l2);
        if (test_bit(FLG_LAPD, &l2->flag)) {
                TEIrelease(l2);
                if (l2->ch.st)
                        l2->ch.st->dev->D.ctrl(&l2->ch.st->dev->D,
                                               CLOSE_CHANNEL, NULL);
        }
        kfree(l2);
}

static int
l2_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
{
        struct layer2           *l2 = container_of(ch, struct layer2, ch);
        u_int                   info;

        if (*debug & DEBUG_L2_CTRL)
                printk(KERN_DEBUG "%s: %s cmd(%x)\n",
                       mISDNDevName4ch(ch), __func__, cmd);

        switch (cmd) {
        case OPEN_CHANNEL:
                if (test_bit(FLG_LAPD, &l2->flag)) {
                        set_channel_address(&l2->ch, l2->sapi, l2->tei);
                        info = DL_INFO_L2_CONNECT;
                        l2up_create(l2, DL_INFORMATION_IND,
                                    sizeof(info), &info);
                }
                break;
        case CLOSE_CHANNEL:
                if (l2->ch.peer)
                        l2->ch.peer->ctrl(l2->ch.peer, CLOSE_CHANNEL, NULL);
                release_l2(l2);
                break;
        }
        return 0;
}

struct layer2 *
create_l2(struct mISDNchannel *ch, u_int protocol, u_long options, int tei,
          int sapi)
{
        struct layer2           *l2;
        struct channel_req      rq;

        l2 = kzalloc_obj(struct layer2);
        if (!l2) {
                printk(KERN_ERR "kzalloc layer2 failed\n");
                return NULL;
        }
        l2->next_id = 1;
        l2->down_id = MISDN_ID_NONE;
        l2->up = ch;
        l2->ch.st = ch->st;
        l2->ch.send = l2_send;
        l2->ch.ctrl = l2_ctrl;
        switch (protocol) {
        case ISDN_P_LAPD_NT:
                test_and_set_bit(FLG_LAPD, &l2->flag);
                test_and_set_bit(FLG_LAPD_NET, &l2->flag);
                test_and_set_bit(FLG_MOD128, &l2->flag);
                l2->sapi = sapi;
                l2->maxlen = MAX_DFRAME_LEN;
                if (test_bit(OPTION_L2_PMX, &options))
                        l2->window = 7;
                else
                        l2->window = 1;
                if (test_bit(OPTION_L2_PTP, &options))
                        test_and_set_bit(FLG_PTP, &l2->flag);
                if (test_bit(OPTION_L2_FIXEDTEI, &options))
                        test_and_set_bit(FLG_FIXED_TEI, &l2->flag);
                l2->tei = tei;
                l2->T200 = 1000;
                l2->N200 = 3;
                l2->T203 = 10000;
                if (test_bit(OPTION_L2_PMX, &options))
                        rq.protocol = ISDN_P_NT_E1;
                else
                        rq.protocol = ISDN_P_NT_S0;
                rq.adr.channel = 0;
                l2->ch.st->dev->D.ctrl(&l2->ch.st->dev->D, OPEN_CHANNEL, &rq);
                break;
        case ISDN_P_LAPD_TE:
                test_and_set_bit(FLG_LAPD, &l2->flag);
                test_and_set_bit(FLG_MOD128, &l2->flag);
                test_and_set_bit(FLG_ORIG, &l2->flag);
                l2->sapi = sapi;
                l2->maxlen = MAX_DFRAME_LEN;
                if (test_bit(OPTION_L2_PMX, &options))
                        l2->window = 7;
                else
                        l2->window = 1;
                if (test_bit(OPTION_L2_PTP, &options))
                        test_and_set_bit(FLG_PTP, &l2->flag);
                if (test_bit(OPTION_L2_FIXEDTEI, &options))
                        test_and_set_bit(FLG_FIXED_TEI, &l2->flag);
                l2->tei = tei;
                l2->T200 = 1000;
                l2->N200 = 3;
                l2->T203 = 10000;
                if (test_bit(OPTION_L2_PMX, &options))
                        rq.protocol = ISDN_P_TE_E1;
                else
                        rq.protocol = ISDN_P_TE_S0;
                rq.adr.channel = 0;
                l2->ch.st->dev->D.ctrl(&l2->ch.st->dev->D, OPEN_CHANNEL, &rq);
                break;
        case ISDN_P_B_X75SLP:
                test_and_set_bit(FLG_LAPB, &l2->flag);
                l2->window = 7;
                l2->maxlen = MAX_DATA_SIZE;
                l2->T200 = 1000;
                l2->N200 = 4;
                l2->T203 = 5000;
                l2->addr.A = 3;
                l2->addr.B = 1;
                break;
        default:
                printk(KERN_ERR "layer2 create failed prt %x\n",
                       protocol);
                kfree(l2);
                return NULL;
        }
        skb_queue_head_init(&l2->i_queue);
        skb_queue_head_init(&l2->ui_queue);
        skb_queue_head_init(&l2->down_queue);
        skb_queue_head_init(&l2->tmp_queue);
        InitWin(l2);
        l2->l2m.fsm = &l2fsm;
        if (test_bit(FLG_LAPB, &l2->flag) ||
            test_bit(FLG_FIXED_TEI, &l2->flag) ||
            test_bit(FLG_LAPD_NET, &l2->flag))
                l2->l2m.state = ST_L2_4;
        else
                l2->l2m.state = ST_L2_1;
        l2->l2m.debug = *debug;
        l2->l2m.userdata = l2;
        l2->l2m.userint = 0;
        l2->l2m.printdebug = l2m_debug;

        mISDN_FsmInitTimer(&l2->l2m, &l2->t200);
        mISDN_FsmInitTimer(&l2->l2m, &l2->t203);
        return l2;
}

static int
x75create(struct channel_req *crq)
{
        struct layer2   *l2;

        if (crq->protocol != ISDN_P_B_X75SLP)
                return -EPROTONOSUPPORT;
        l2 = create_l2(crq->ch, crq->protocol, 0, 0, 0);
        if (!l2)
                return -ENOMEM;
        crq->ch = &l2->ch;
        crq->protocol = ISDN_P_B_HDLC;
        return 0;
}

static struct Bprotocol X75SLP = {
        .Bprotocols = (1 << (ISDN_P_B_X75SLP & ISDN_P_B_MASK)),
        .name = "X75SLP",
        .create = x75create
};

int
Isdnl2_Init(u_int *deb)
{
        int res;
        debug = deb;
        mISDN_register_Bprotocol(&X75SLP);
        l2fsm.state_count = L2_STATE_COUNT;
        l2fsm.event_count = L2_EVENT_COUNT;
        l2fsm.strEvent = strL2Event;
        l2fsm.strState = strL2State;
        res = mISDN_FsmNew(&l2fsm, L2FnList, ARRAY_SIZE(L2FnList));
        if (res)
                goto error;
        res = TEIInit(deb);
        if (res)
                goto error_fsm;
        return 0;

error_fsm:
        mISDN_FsmFree(&l2fsm);
error:
        mISDN_unregister_Bprotocol(&X75SLP);
        return res;
}

void
Isdnl2_cleanup(void)
{
        mISDN_unregister_Bprotocol(&X75SLP);
        TEIFree();
        mISDN_FsmFree(&l2fsm);
}