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-rw-r--r--sys/netccitt/hd_output.c247
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diff --git a/sys/netccitt/hd_output.c b/sys/netccitt/hd_output.c
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+/*
+ * 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.
+ *
+ * @(#)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>
+
+/*
+ * 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);
+ }
+}