isdnl3.c

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/* $Id: isdnl3.c,v 2.22.2.3 2004/01/13 14:31:25 keil Exp $
 *
 * Author       Karsten Keil
 *              based on the teles driver from Jan den Ouden
 * Copyright    by Karsten Keil      <[email protected]>
 *
 * 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 <linux/slab.h>
#include "hisax.h"
#include "isdnl3.h"

const char *l3_revision = "$Revision: 2.22.2.3 $";

static struct Fsm l3fsm;

enum {
    ST_L3_LC_REL,
    ST_L3_LC_ESTAB_WAIT,
    ST_L3_LC_REL_DELAY,
    ST_L3_LC_REL_WAIT,
    ST_L3_LC_ESTAB,
};

#define L3_STATE_COUNT (ST_L3_LC_ESTAB + 1)

static char *strL3State[] =
{
    "ST_L3_LC_REL",
    "ST_L3_LC_ESTAB_WAIT",
    "ST_L3_LC_REL_DELAY",
    "ST_L3_LC_REL_WAIT",
    "ST_L3_LC_ESTAB",
};

enum {
    EV_ESTABLISH_REQ,
    EV_ESTABLISH_IND,
    EV_ESTABLISH_CNF,
    EV_RELEASE_REQ,
    EV_RELEASE_CNF,
    EV_RELEASE_IND,
    EV_TIMEOUT,
};

#define L3_EVENT_COUNT (EV_TIMEOUT + 1)

static char *strL3Event[] =
{
    "EV_ESTABLISH_REQ",
    "EV_ESTABLISH_IND",
    "EV_ESTABLISH_CNF",
    "EV_RELEASE_REQ",
    "EV_RELEASE_CNF",
    "EV_RELEASE_IND",
    "EV_TIMEOUT",
};

static __printf(2, 3) void
    l3m_debug(struct FsmInst *fi, char *fmt, ...)
{
    va_list args;
    struct PStack *st = fi->userdata;

    va_start(args, fmt);
    VHiSax_putstatus(st->l1.hardware, st->l3.debug_id, fmt, args);
    va_end(args);
}

u_char *
findie(u_char *p, int size, u_char ie, int wanted_set)
{
    int l, codeset, maincodeset;
    u_char *pend = p + size;

    /* skip protocol discriminator, callref and message type */
    p++;
    l = (*p++) & 0xf;
    p += l;
    p++;
    codeset = 0;
    maincodeset = 0;
    /* while there are bytes left... */
    while (p < pend) {
        if ((*p & 0xf0) == 0x90) {
            codeset = *p & 0x07;
            if (!(*p & 0x08))
                maincodeset = codeset;
        }
        if (*p & 0x80)
            p++;
        else {
            if (codeset == wanted_set) {
                if (*p == ie)
                { /* improved length check (Werner Cornelius) */
                    if ((pend - p) < 2)
                        return (NULL);
                    if (*(p + 1) > (pend - (p + 2)))
                        return (NULL);
                    return (p);
                }

                if (*p > ie)
                    return (NULL);
            }
            p++;
            l = *p++;
            p += l;
            codeset = maincodeset;
        }
    }
    return (NULL);
}

int
getcallref(u_char *p)
{
    int l, cr = 0;

    p++;            /* prot discr */
    if (*p & 0xfe)      /* wrong callref BRI only 1 octet*/
        return (-2);
    l = 0xf & *p++;     /* callref length */
    if (!l)         /* dummy CallRef */
        return (-1);
    cr = *p++;
    return (cr);
}

static int OrigCallRef = 0;

int
newcallref(void)
{
    if (OrigCallRef == 127)
        OrigCallRef = 1;
    else
        OrigCallRef++;
    return (OrigCallRef);
}

void
newl3state(struct l3_process *pc, int state)
{
    if (pc->debug & L3_DEB_STATE)
        l3_debug(pc->st, "newstate cr %d %d --> %d",
             pc->callref & 0x7F,
             pc->state, state);
    pc->state = state;
}

static void
L3ExpireTimer(struct L3Timer *t)
{
    t->pc->st->lli.l4l3(t->pc->st, t->event, t->pc);
}

void
L3InitTimer(struct l3_process *pc, struct L3Timer *t)
{
    t->pc = pc;
    t->tl.function = (void *) L3ExpireTimer;
    t->tl.data = (long) t;
    init_timer(&t->tl);
}

void
L3DelTimer(struct L3Timer *t)
{
    del_timer(&t->tl);
}

int
L3AddTimer(struct L3Timer *t,
       int millisec, int event)
{
    if (timer_pending(&t->tl)) {
        printk(KERN_WARNING "L3AddTimer: timer already active!\n");
        return -1;
    }
    init_timer(&t->tl);
    t->event = event;
    t->tl.expires = jiffies + (millisec * HZ) / 1000;
    add_timer(&t->tl);
    return 0;
}

void
StopAllL3Timer(struct l3_process *pc)
{
    L3DelTimer(&pc->timer);
}

struct sk_buff *
l3_alloc_skb(int len)
{
    struct sk_buff *skb;

    if (!(skb = alloc_skb(len + MAX_HEADER_LEN, GFP_ATOMIC))) {
        printk(KERN_WARNING "HiSax: No skb for D-channel\n");
        return (NULL);
    }
    skb_reserve(skb, MAX_HEADER_LEN);
    return (skb);
}

static void
no_l3_proto(struct PStack *st, int pr, void *arg)
{
    struct sk_buff *skb = arg;

    HiSax_putstatus(st->l1.hardware, "L3", "no D protocol");
    if (skb) {
        dev_kfree_skb(skb);
    }
}

static int
no_l3_proto_spec(struct PStack *st, isdn_ctrl *ic)
{
    printk(KERN_WARNING "HiSax: no specific protocol handler for proto %lu\n", ic->arg & 0xFF);
    return (-1);
}

struct l3_process
*getl3proc(struct PStack *st, int cr)
{
    struct l3_process *p = st->l3.proc;

    while (p)
        if (p->callref == cr)
            return (p);
        else
            p = p->next;
    return (NULL);
}

struct l3_process
*new_l3_process(struct PStack *st, int cr)
{
    struct l3_process *p, *np;

    if (!(p = kmalloc(sizeof(struct l3_process), GFP_ATOMIC))) {
        printk(KERN_ERR "HiSax can't get memory for cr %d\n", cr);
        return (NULL);
    }
    if (!st->l3.proc)
        st->l3.proc = p;
    else {
        np = st->l3.proc;
        while (np->next)
            np = np->next;
        np->next = p;
    }
    p->next = NULL;
    p->debug = st->l3.debug;
    p->callref = cr;
    p->state = 0;
    p->chan = NULL;
    p->st = st;
    p->N303 = st->l3.N303;
    L3InitTimer(p, &p->timer);
    return (p);
};

void
release_l3_process(struct l3_process *p)
{
    struct l3_process *np, *pp = NULL;

    if (!p)
        return;
    np = p->st->l3.proc;
    while (np) {
        if (np == p) {
            StopAllL3Timer(p);
            if (pp)
                pp->next = np->next;
            else if (!(p->st->l3.proc = np->next) &&
                 !test_bit(FLG_PTP, &p->st->l2.flag)) {
                if (p->debug)
                    l3_debug(p->st, "release_l3_process: last process");
                if (skb_queue_empty(&p->st->l3.squeue)) {
                    if (p->debug)
                        l3_debug(p->st, "release_l3_process: release link");
                    if (p->st->protocol != ISDN_PTYPE_NI1)
                        FsmEvent(&p->st->l3.l3m, EV_RELEASE_REQ, NULL);
                    else
                        FsmEvent(&p->st->l3.l3m, EV_RELEASE_IND, NULL);
                } else {
                    if (p->debug)
                        l3_debug(p->st, "release_l3_process: not release link");
                }
            }
            kfree(p);
            return;
        }
        pp = np;
        np = np->next;
    }
    printk(KERN_ERR "HiSax internal L3 error CR(%d) not in list\n", p->callref);
    l3_debug(p->st, "HiSax internal L3 error CR(%d) not in list", p->callref);
};

static void
l3ml3p(struct PStack *st, int pr)
{
    struct l3_process *p = st->l3.proc;
    struct l3_process *np;

    while (p) {
        /* p might be kfreed under us, so we need to save where we want to go on */
        np = p->next;
        st->l3.l3ml3(st, pr, p);
        p = np;
    }
}

void
setstack_l3dc(struct PStack *st, struct Channel *chanp)
{
    char tmp[64];

    st->l3.proc   = NULL;
    st->l3.global = NULL;
    skb_queue_head_init(&st->l3.squeue);
    st->l3.l3m.fsm = &l3fsm;
    st->l3.l3m.state = ST_L3_LC_REL;
    st->l3.l3m.debug = 1;
    st->l3.l3m.userdata = st;
    st->l3.l3m.userint = 0;
    st->l3.l3m.printdebug = l3m_debug;
    FsmInitTimer(&st->l3.l3m, &st->l3.l3m_timer);
    strcpy(st->l3.debug_id, "L3DC ");
    st->lli.l4l3_proto = no_l3_proto_spec;

#ifdef CONFIG_HISAX_EURO
    if (st->protocol == ISDN_PTYPE_EURO) {
        setstack_dss1(st);
    } else
#endif
#ifdef CONFIG_HISAX_NI1
        if (st->protocol == ISDN_PTYPE_NI1) {
            setstack_ni1(st);
        } else
#endif
#ifdef CONFIG_HISAX_1TR6
            if (st->protocol == ISDN_PTYPE_1TR6) {
                setstack_1tr6(st);
            } else
#endif
                if (st->protocol == ISDN_PTYPE_LEASED) {
                    st->lli.l4l3 = no_l3_proto;
                    st->l2.l2l3 = no_l3_proto;
                    st->l3.l3ml3 = no_l3_proto;
                    printk(KERN_INFO "HiSax: Leased line mode\n");
                } else {
                    st->lli.l4l3 = no_l3_proto;
                    st->l2.l2l3 = no_l3_proto;
                    st->l3.l3ml3 = no_l3_proto;
                    sprintf(tmp, "protocol %s not supported",
                        (st->protocol == ISDN_PTYPE_1TR6) ? "1tr6" :
                        (st->protocol == ISDN_PTYPE_EURO) ? "euro" :
                        (st->protocol == ISDN_PTYPE_NI1) ? "ni1" :
                        "unknown");
                    printk(KERN_WARNING "HiSax: %s\n", tmp);
                    st->protocol = -1;
                }
}

static void
isdnl3_trans(struct PStack *st, int pr, void *arg) {
    st->l3.l3l2(st, pr, arg);
}

void
releasestack_isdnl3(struct PStack *st)
{
    while (st->l3.proc)
        release_l3_process(st->l3.proc);
    if (st->l3.global) {
        StopAllL3Timer(st->l3.global);
        kfree(st->l3.global);
        st->l3.global = NULL;
    }
    FsmDelTimer(&st->l3.l3m_timer, 54);
    skb_queue_purge(&st->l3.squeue);
}

void
setstack_l3bc(struct PStack *st, struct Channel *chanp)
{

    st->l3.proc   = NULL;
    st->l3.global = NULL;
    skb_queue_head_init(&st->l3.squeue);
    st->l3.l3m.fsm = &l3fsm;
    st->l3.l3m.state = ST_L3_LC_REL;
    st->l3.l3m.debug = 1;
    st->l3.l3m.userdata = st;
    st->l3.l3m.userint = 0;
    st->l3.l3m.printdebug = l3m_debug;
    strcpy(st->l3.debug_id, "L3BC ");
    st->lli.l4l3 = isdnl3_trans;
}

#define DREL_TIMER_VALUE 40000

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

    FsmChangeState(fi, ST_L3_LC_ESTAB_WAIT);
    st->l3.l3l2(st, DL_ESTABLISH | REQUEST, NULL);
}

static void
lc_connect(struct FsmInst *fi, int event, void *arg)
{
    struct PStack *st = fi->userdata;
    struct sk_buff *skb = arg;
    int dequeued = 0;

    FsmChangeState(fi, ST_L3_LC_ESTAB);
    while ((skb = skb_dequeue(&st->l3.squeue))) {
        st->l3.l3l2(st, DL_DATA | REQUEST, skb);
        dequeued++;
    }
    if ((!st->l3.proc) &&  dequeued) {
        if (st->l3.debug)
            l3_debug(st, "lc_connect: release link");
        FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
    } else
        l3ml3p(st, DL_ESTABLISH | INDICATION);
}

static void
lc_connected(struct FsmInst *fi, int event, void *arg)
{
    struct PStack *st = fi->userdata;
    struct sk_buff *skb = arg;
    int dequeued = 0;

    FsmDelTimer(&st->l3.l3m_timer, 51);
    FsmChangeState(fi, ST_L3_LC_ESTAB);
    while ((skb = skb_dequeue(&st->l3.squeue))) {
        st->l3.l3l2(st, DL_DATA | REQUEST, skb);
        dequeued++;
    }
    if ((!st->l3.proc) &&  dequeued) {
        if (st->l3.debug)
            l3_debug(st, "lc_connected: release link");
        FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
    } else
        l3ml3p(st, DL_ESTABLISH | CONFIRM);
}

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

    FsmChangeState(fi, ST_L3_LC_REL_DELAY);
    FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
}

static void
lc_start_delay_check(struct FsmInst *fi, int event, void *arg)
/* 20/09/00 - GE timer not user for NI-1 as layer 2 should stay up */
{
    struct PStack *st = fi->userdata;

    FsmChangeState(fi, ST_L3_LC_REL_DELAY);
    /* 19/09/00 - GE timer not user for NI-1 */
    if (st->protocol != ISDN_PTYPE_NI1)
        FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
}

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

    if (test_bit(FLG_L2BLOCK, &st->l2.flag)) {
        if (st->l3.debug)
            l3_debug(st, "lc_release_req: l2 blocked");
        /* restart release timer */
        FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 51);
    } else {
        FsmChangeState(fi, ST_L3_LC_REL_WAIT);
        st->l3.l3l2(st, DL_RELEASE | REQUEST, NULL);
    }
}

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

    FsmDelTimer(&st->l3.l3m_timer, 52);
    FsmChangeState(fi, ST_L3_LC_REL);
    skb_queue_purge(&st->l3.squeue);
    l3ml3p(st, DL_RELEASE | INDICATION);
}

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

    FsmChangeState(fi, ST_L3_LC_REL);
    skb_queue_purge(&st->l3.squeue);
    l3ml3p(st, DL_RELEASE | CONFIRM);
}


/* *INDENT-OFF* */
static struct FsmNode L3FnList[] __initdata =
{
    {ST_L3_LC_REL,      EV_ESTABLISH_REQ,   lc_activate},
    {ST_L3_LC_REL,      EV_ESTABLISH_IND,   lc_connect},
    {ST_L3_LC_REL,      EV_ESTABLISH_CNF,   lc_connect},
    {ST_L3_LC_ESTAB_WAIT,   EV_ESTABLISH_CNF,   lc_connected},
    {ST_L3_LC_ESTAB_WAIT,   EV_RELEASE_REQ,     lc_start_delay},
    {ST_L3_LC_ESTAB_WAIT,   EV_RELEASE_IND,     lc_release_ind},
    {ST_L3_LC_ESTAB,    EV_RELEASE_IND,     lc_release_ind},
    {ST_L3_LC_ESTAB,    EV_RELEASE_REQ,     lc_start_delay_check},
    {ST_L3_LC_REL_DELAY,    EV_RELEASE_IND,         lc_release_ind},
    {ST_L3_LC_REL_DELAY,    EV_ESTABLISH_REQ,       lc_connected},
    {ST_L3_LC_REL_DELAY,    EV_TIMEOUT,             lc_release_req},
    {ST_L3_LC_REL_WAIT, EV_RELEASE_CNF,     lc_release_cnf},
    {ST_L3_LC_REL_WAIT, EV_ESTABLISH_REQ,   lc_activate},
};
/* *INDENT-ON* */

void
l3_msg(struct PStack *st, int pr, void *arg)
{
    switch (pr) {
    case (DL_DATA | REQUEST):
        if (st->l3.l3m.state == ST_L3_LC_ESTAB) {
            st->l3.l3l2(st, pr, arg);
        } else {
            struct sk_buff *skb = arg;

            skb_queue_tail(&st->l3.squeue, skb);
            FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
        }
        break;
    case (DL_ESTABLISH | REQUEST):
        FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
        break;
    case (DL_ESTABLISH | CONFIRM):
        FsmEvent(&st->l3.l3m, EV_ESTABLISH_CNF, NULL);
        break;
    case (DL_ESTABLISH | INDICATION):
        FsmEvent(&st->l3.l3m, EV_ESTABLISH_IND, NULL);
        break;
    case (DL_RELEASE | INDICATION):
        FsmEvent(&st->l3.l3m, EV_RELEASE_IND, NULL);
        break;
    case (DL_RELEASE | CONFIRM):
        FsmEvent(&st->l3.l3m, EV_RELEASE_CNF, NULL);
        break;
    case (DL_RELEASE | REQUEST):
        FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
        break;
    }
}

int __init
Isdnl3New(void)
{
    l3fsm.state_count = L3_STATE_COUNT;
    l3fsm.event_count = L3_EVENT_COUNT;
    l3fsm.strEvent = strL3Event;
    l3fsm.strState = strL3State;
    return FsmNew(&l3fsm, L3FnList, ARRAY_SIZE(L3FnList));
}

void
Isdnl3Free(void)
{
    FsmFree(&l3fsm);
}