249 lines
7.0 KiB
C
249 lines
7.0 KiB
C
/*
|
|
* 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. 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.
|
|
*
|
|
* from: @(#)hd_output.c 8.1 (Berkeley) 6/10/93
|
|
* $Id: hd_output.c,v 1.4 1994/05/13 06:04:19 mycroft Exp $
|
|
*/
|
|
|
|
#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>
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
hd_output (hdp, m0)
|
|
register struct hdcb *hdp;
|
|
struct mbuf *m0;
|
|
{
|
|
struct x25config *xcp;
|
|
register struct mbuf *m = m0;
|
|
int len;
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
}
|
|
|
|
hd_start (hdp)
|
|
register struct hdcb *hdp;
|
|
{
|
|
register 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.
|
|
*/
|
|
|
|
hd_send_iframe (hdp, buf, poll_bit)
|
|
register struct hdcb *hdp;
|
|
register struct mbuf *buf;
|
|
int poll_bit;
|
|
{
|
|
register 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[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)(hdp, m);
|
|
SET_TIMER (hdp);
|
|
}
|
|
|
|
hd_ifoutput(hdp, m)
|
|
register struct mbuf *m;
|
|
register struct hdcb *hdp;
|
|
{
|
|
/*
|
|
* Queue message on interface, and start output if interface
|
|
* not yet active.
|
|
*/
|
|
register struct ifnet *ifp = hdp->hd_ifp;
|
|
int s = splimp();
|
|
|
|
if (IF_QFULL(&ifp->if_snd)) {
|
|
IF_DROP(&ifp->if_snd);
|
|
/* printf("%s%d: HDLC says OK to send but queue full, may hang\n",
|
|
ifp->if_name, ifp->if_unit);*/
|
|
m_freem(m);
|
|
} else {
|
|
IF_ENQUEUE(&ifp->if_snd, m);
|
|
if ((ifp->if_flags & IFF_OACTIVE) == 0)
|
|
(*ifp->if_start)(ifp);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
|
|
/*
|
|
* This routine gets control when the timer expires because we have not
|
|
* received an acknowledgement for a iframe.
|
|
*/
|
|
|
|
hd_resend_iframe (hdp)
|
|
register 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[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, hdp->hd_pkp);
|
|
}
|
|
}
|