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/* $OpenBSD: hd_output.c,v 1.7 2004/01/03 14:08:53 espie Exp $ */
/* $NetBSD: hd_output.c,v 1.7 1996/05/07 02:36:06 thorpej Exp $ */
/*
* Copyright (c) University of British Columbia, 1984
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Laboratory for Computation Vision and the Computer Science Department
* of the University of British Columbia.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)hd_output.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <netccitt/hdlc.h>
#include <netccitt/hd_var.h>
#include <netccitt/x25.h>
#include <netccitt/pk_extern.h>
#include <sys/stdarg.h>
/*
* HDLC OUTPUT INTERFACE
*
* This routine is called when the X.25 packet layer output routine
* has a information frame (iframe) to write. It is also called
* by the input and control routines of the HDLC layer.
*/
int
hd_output(struct mbuf *m0, ...)
{
struct hdcb *hdp;
struct mbuf *m = m0;
int len;
va_list ap;
va_start(ap, m0);
hdp = va_arg(ap, struct hdcb *);
va_end(ap);
if (m == NULL)
panic("hd_output");
if ((m->m_flags & M_PKTHDR) == 0)
panic("hd_output 2");
if (hdp->hd_state != ABM) {
m_freem(m);
return 0;
}
/*
* Make room for the hdlc header either by prepending
* another mbuf, or by adjusting the offset and length
* of the first mbuf in the mbuf chain.
*/
M_PREPEND(m, HDHEADERLN, M_DONTWAIT);
if (m == NULL)
return 0;
for (len = 0; m; m = m->m_next)
len += m->m_len;
m = m0;
m->m_pkthdr.len = len;
hd_append(&hdp->hd_txq, m);
hd_start(hdp);
return 0;
}
void
hd_start(hdp)
struct hdcb *hdp;
{
struct mbuf *m;
/*
* The iframe is only transmitted if all these conditions are FALSE.
* The iframe remains queued (hdp->hd_txq) however and will be
* transmitted as soon as these conditions are cleared.
*/
while (!(hdp->hd_condition & (TIMER_RECOVERY_CONDITION |
REMOTE_RNR_CONDITION | REJ_CONDITION))) {
if (hdp->hd_vs ==
(hdp->hd_lastrxnr + hdp->hd_xcp->xc_lwsize) % MODULUS) {
/*
* We have now exceeded the maximum number of
* outstanding iframes. Therefore, we must wait
* until at least one is acknowledged if this
* condition is not turned off before we are
* requested to write another iframe.
*/
hdp->hd_window_condition++;
break;
}
/* hd_remove top iframe from transmit queue. */
if ((m = hd_remove(&hdp->hd_txq)) == NULL)
break;
hd_send_iframe(hdp, m, POLLOFF);
}
}
/*
* This procedure is passed a buffer descriptor for an iframe. It builds the
* rest of the control part of the frame and then writes it out. It also
* starts the acknowledgement timer and keeps the iframe in the Retransmit
* queue (Retxq) just in case we have to do this again.
*
* Note: This routine is also called from hd_input.c when retransmission of old
* frames is required.
*/
void
hd_send_iframe(hdp, buf, poll_bit)
struct hdcb *hdp;
struct mbuf *buf;
int poll_bit;
{
struct Hdlc_iframe *iframe;
struct mbuf *m;
KILL_TIMER(hdp);
if (buf == 0) {
printf("hd_send_iframe: zero arg\n");
#ifdef HDLCDEBUG
hd_status(hdp);
hd_dumptrace(hdp);
#endif
hdp->hd_vs = (hdp->hd_vs + 7) % MODULUS;
return;
}
iframe = mtod(buf, struct Hdlc_iframe *);
iframe->hdlc_0 = 0;
iframe->nr = hdp->hd_vr;
iframe->pf = poll_bit;
iframe->ns = hdp->hd_vs;
iframe->address = ADDRESS_B;
hdp->hd_lasttxnr = hdp->hd_vr;
hdp->hd_rrtimer = 0;
if (hdp->hd_vs == hdp->hd_retxqi) {
/* Check for retransmissions. */
/* Put iframe only once in the Retransmission queue. */
hdp->hd_retxq[(u_char) hdp->hd_retxqi] = buf;
hdp->hd_retxqi = (hdp->hd_retxqi + 1) % MODULUS;
hdp->hd_iframes_out++;
}
hdp->hd_vs = (hdp->hd_vs + 1) % MODULUS;
hd_trace(hdp, TX, (struct Hdlc_frame *) iframe);
/* Write buffer on device. */
m = hdp->hd_dontcopy ? buf : m_copy(buf, 0, (int) M_COPYALL);
if (m == 0) {
printf("hdlc: out of mbufs\n");
return;
}
(*hdp->hd_output) (m, hdp);
SET_TIMER(hdp);
}
int
hd_ifoutput(struct mbuf *m, ...)
{
struct hdcb *hdp;
struct ifnet *ifp;
int s = splimp();
va_list ap;
va_start(ap, m);
hdp = va_arg(ap, struct hdcb *);
va_end(ap);
ifp = hdp->hd_ifp;
/*
* Queue message on interface, and start output if interface
* not yet active.
*/
if (IF_QFULL(&ifp->if_snd)) {
IF_DROP(&ifp->if_snd);
/*
* printf("%s: HDLC says OK to send but queue full, may
* hang\n", ifp->if_xname);
*/
m_freem(m);
} else {
IF_ENQUEUE(&ifp->if_snd, m);
if ((ifp->if_flags & IFF_OACTIVE) == 0)
(*ifp->if_start) (ifp);
}
splx(s);
return 0;
}
/*
* This routine gets control when the timer expires because we have not
* received an acknowledgement for a iframe.
*/
void
hd_resend_iframe(hdp)
struct hdcb *hdp;
{
if (hdp->hd_retxcnt++ < hd_n2) {
if (!(hdp->hd_condition & TIMER_RECOVERY_CONDITION)) {
hdp->hd_xx = hdp->hd_vs;
hdp->hd_condition |= TIMER_RECOVERY_CONDITION;
}
hdp->hd_vs = hdp->hd_lastrxnr;
hd_send_iframe(hdp, hdp->hd_retxq[(u_char)hdp->hd_vs], POLLON);
} else {
/*
* At this point we have not received a RR even after N2
* retries - attempt to reset link.
*/
hd_initvars(hdp);
hd_writeinternal(hdp, SABM, POLLOFF);
hdp->hd_state = WAIT_UA;
SET_TIMER(hdp);
hd_message(hdp, "Timer recovery failed: link down");
(void) pk_ctlinput(PRC_LINKDOWN,
(struct sockaddr *)hdp->hd_pkp, NULL);
}
}
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