/* $OpenBSD: hd_output.c,v 1.2 1996/03/04 07:36:24 niklas Exp $ */ /* $NetBSD: hd_output.c,v 1.6 1996/02/13 22:04:29 christos 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. 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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 #if __STDC__ hd_output(struct mbuf *m0, ...) #else hd_output(m0, va_alist) struct mbuf *m0; va_dcl #endif { register struct hdcb *hdp; register 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) 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. */ void 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[(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 #if __STDC__ hd_ifoutput(struct mbuf *m, ...) #else hd_ifoutput(m, va_alist) struct mbuf *m; va_dcl #endif { register struct hdcb *hdp; register 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%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); 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) 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[(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); } }