NetBSD/sys/netisdn/i4b_iframe.c
martin 5171d409a5 First step to cleanup the hardware driver <-> upper layers interface.
This now provides slightly more functionality than the FreeBSD layer1-newbus
interface. It was meant to be a simple change to one header and a few
c files, but the change rippled all through various stuff.

To prevent a change to the kernel<->userland interface right now the kernel
is now lying about card types to userland (but who cares). This will be fixed
when the userland interface changes, after layer 3 <-> layer 4 has been
fixed.

Functional changes:

Provide a clean interface for hardware drivers to attach to the upper
layers. This will need another small change in the B-channel handling
when a similar change to the layer 3 <-> layer 4 interface happens.

Avoid passing indices into global arrays of pointers around, instead pass
the pointers itself. Don't code hardware driver types by predefined magic
numbers (think LKM). Prepare for detachable drivers (think pcmcia).

While there remove some sets of function pointers always pointing to the
same function (meant to be the configurable set of D channel protocol
handlers). It is unlikely another supported D-channel protocol will fit into
that (maximal layer interface) abstraction. When we get support for another
protocol, we will need to come up with a workable interface. Besides, the
old implementation was, uhm, strange.
2001-03-24 12:40:29 +00:00

291 lines
7.1 KiB
C

/*
* Copyright (c) 1997, 2000 Hellmuth Michaelis. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*---------------------------------------------------------------------------
*
* i4b_iframe.c - i frame handling routines
* ------------------------------------------
*
* $Id: i4b_iframe.c,v 1.3 2001/03/24 12:40:31 martin Exp $
*
* $FreeBSD$
*
* last edit-date: [Fri Jan 5 11:33:47 2001]
*
*---------------------------------------------------------------------------*/
#ifdef __FreeBSD__
#include "i4bq921.h"
#else
#define NI4BQ921 1
#endif
#if NI4BQ921 > 0
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/if.h>
#if defined(__NetBSD__) && __NetBSD_Version__ >= 104230000
#include <sys/callout.h>
#endif
#ifdef __FreeBSD__
#include <machine/i4b_debug.h>
#include <machine/i4b_ioctl.h>
#include <machine/i4b_trace.h>
#else
#include <netisdn/i4b_debug.h>
#include <netisdn/i4b_ioctl.h>
#include <netisdn/i4b_trace.h>
#endif
#include <netisdn/i4b_global.h>
#include <netisdn/i4b_l1l2.h>
#include <netisdn/i4b_isdnq931.h>
#include <netisdn/i4b_mbuf.h>
#include <netisdn/i4b_l2.h>
#include <netisdn/i4b_l2fsm.h>
/*---------------------------------------------------------------------------*
* process i frame
* implements the routine "I COMMAND" Q.921 03/93 pp 68 and pp 77
*---------------------------------------------------------------------------*/
void
i4b_rxd_i_frame(l2_softc_t *l2sc, struct mbuf *m)
{
u_char *ptr = m->m_data;
int nr;
int ns;
int p;
int s;
if(!((l2sc->tei_valid == TEI_VALID) &&
(l2sc->tei == GETTEI(*(ptr+OFF_TEI)))))
{
i4b_Dfreembuf(m);
return;
}
if((l2sc->Q921_state != ST_MULTIFR) && (l2sc->Q921_state != ST_TIMREC))
{
i4b_Dfreembuf(m);
NDBGL2(L2_I_ERR, "ERROR, state != (MF || TR)!");
return;
}
s = splnet();
l2sc->stat.rx_i++; /* update frame count */
nr = GETINR(*(ptr + OFF_INR));
ns = GETINS(*(ptr + OFF_INS));
p = GETIP(*(ptr + OFF_INR));
i4b_rxd_ack(l2sc, nr); /* last packet ack */
if(l2sc->own_busy) /* own receiver busy ? */
{
i4b_Dfreembuf(m); /* yes, discard information */
if(p == 1) /* P bit == 1 ? */
{
i4b_tx_rnr_response(l2sc, p); /* yes, tx RNR */
l2sc->ack_pend = 0; /* clear ACK pending */
}
}
else /* own receiver ready */
{
if(ns == l2sc->vr) /* expected sequence number ? */
{
M128INC(l2sc->vr); /* yes, update */
l2sc->rej_excpt = 0; /* clr reject exception */
m_adj(m, I_HDR_LEN); /* strip i frame header */
l2sc->iframe_sent = 0; /* reset i acked already */
i4b_dl_data_ind(l2sc->bri, m); /* pass data up */
if(!l2sc->iframe_sent)
{
i4b_tx_rr_response(l2sc, p); /* yes, tx RR */
l2sc->ack_pend = 0; /* clr ACK pending */
}
}
else /* ERROR, sequence number NOT expected */
{
i4b_Dfreembuf(m); /* discard information */
if(l2sc->rej_excpt == 1) /* already exception ? */
{
if(p == 1) /* immediate response ? */
{
i4b_tx_rr_response(l2sc, p); /* yes, tx RR */
l2sc->ack_pend = 0; /* clr ack pend */
}
}
else /* not in exception cond */
{
l2sc->rej_excpt = 1; /* set exception */
i4b_tx_rej_response(l2sc, p); /* tx REJ */
l2sc->ack_pend = 0; /* clr ack pending */
}
}
}
/* sequence number ranges as expected ? */
if(i4b_l2_nr_ok(nr, l2sc->va, l2sc->vs))
{
if(l2sc->Q921_state == ST_TIMREC)
{
l2sc->va = nr;
splx(s);
return;
}
if(l2sc->peer_busy) /* yes, other side busy ? */
{
l2sc->va = nr; /* yes, update ack count */
}
else /* other side ready */
{
if(nr == l2sc->vs) /* count expected ? */
{
l2sc->va = nr; /* update ack */
i4b_T200_stop(l2sc);
i4b_T203_restart(l2sc);
}
else
{
if(nr != l2sc->va)
{
l2sc->va = nr;
i4b_T200_restart(l2sc);
}
}
}
}
else
{
i4b_nr_error_recovery(l2sc); /* sequence error */
l2sc->Q921_state = ST_AW_EST;
}
splx(s);
}
/*---------------------------------------------------------------------------*
* internal I FRAME QUEUED UP routine (Q.921 03/93 p 61)
*---------------------------------------------------------------------------*/
void
i4b_i_frame_queued_up(l2_softc_t *l2sc)
{
struct mbuf *m;
u_char *ptr;
int s;
s = splnet();
if((l2sc->peer_busy) || (l2sc->vs == ((l2sc->va + MAX_K_VALUE) & 127)))
{
if(l2sc->peer_busy)
{
NDBGL2(L2_I_MSG, "regen IFQUP, cause: peer busy!");
}
if(l2sc->vs == ((l2sc->va + MAX_K_VALUE) & 127))
{
NDBGL2(L2_I_MSG, "regen IFQUP, cause: vs=va+k!");
}
/*
* XXX see: Q.921, page 36, 5.6.1 ".. may retransmit an I
* frame ...", shall we retransmit the last i frame ?
*/
if(!(IF_QEMPTY(&l2sc->i_queue)))
{
NDBGL2(L2_I_MSG, "re-scheduling IFQU call!");
START_TIMER(l2sc->IFQU_callout, i4b_i_frame_queued_up, l2sc, IFQU_DLY);
}
splx(s);
return;
}
IF_DEQUEUE(&l2sc->i_queue, m); /* fetch next frame to tx */
if(!m)
{
NDBGL2(L2_I_ERR, "ERROR, mbuf NULL after IF_DEQUEUE");
splx(s);
return;
}
ptr = m->m_data;
PUTSAPI(SAPI_CCP, CR_CMD_TO_NT, *(ptr + OFF_SAPI));
PUTTEI(l2sc->tei, *(ptr + OFF_TEI));
*(ptr + OFF_INS) = (l2sc->vs << 1) & 0xfe; /* bit 0 = 0 */
*(ptr + OFF_INR) = (l2sc->vr << 1) & 0xfe; /* P bit = 0 */
l2sc->stat.tx_i++; /* update frame counter */
l2sc->driver->ph_data_req(l2sc->l1_token, m, MBUF_DONTFREE); /* free'd when ack'd ! */
l2sc->iframe_sent = 1; /* in case we ack an I frame with another I frame */
if(l2sc->ua_num != UA_EMPTY) /* failsafe */
{
NDBGL2(L2_I_ERR, "ERROR, l2sc->ua_num: %d != UA_EMPTY", l2sc->ua_num);
i4b_print_l2var(l2sc);
i4b_Dfreembuf(l2sc->ua_frame);
}
l2sc->ua_frame = m; /* save unacked frame */
l2sc->ua_num = l2sc->vs; /* save frame number */
M128INC(l2sc->vs);
l2sc->ack_pend = 0;
splx(s);
if(l2sc->T200 == TIMER_IDLE)
{
i4b_T203_stop(l2sc);
i4b_T200_start(l2sc);
}
}
#endif /* NI4BQ921 > 0 */