/* * 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 1.25 2000/08/24 11:48:57 hm Exp $ * * $FreeBSD: src/sys/i4b/layer2/i4b_iframe.c,v 1.6.2.1 2001/08/10 14:08:41 obrien Exp $ * $DragonFly: src/sys/net/i4b/layer2/i4b_iframe.c,v 1.2 2003/06/17 04:28:40 dillon Exp $ * * last edit-date: [Thu Aug 24 12:49:18 2000] * *---------------------------------------------------------------------------*/ #ifdef __FreeBSD__ #include "i4bq921.h" #else #define NI4BQ921 1 #endif #if NI4BQ921 > 0 #include #include #include #include #include #include #if defined(__NetBSD__) && __NetBSD_Version__ >= 104230000 #include #endif #ifdef __FreeBSD__ #include #include #else #include #include #include #endif #include #include #include #include #include #include /*---------------------------------------------------------------------------* * process i frame * implements the routine "I COMMAND" Q.921 03/93 pp 68 and pp 77 *---------------------------------------------------------------------------*/ void i4b_rxd_i_frame(int unit, struct mbuf *m) { l2_softc_t *l2sc = &l2_softc[unit]; u_char *ptr = m->m_data; int nr; int ns; int p; CRIT_VAR; 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; } CRIT_BEG; 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 */ DL_Data_Ind(l2sc->unit, 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; CRIT_END; 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; } CRIT_END; } /*---------------------------------------------------------------------------* * 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; CRIT_VAR; CRIT_BEG; 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); } CRIT_END; return; } IF_DEQUEUE(&l2sc->i_queue, m); /* fetch next frame to tx */ if(!m) { NDBGL2(L2_I_ERR, "ERROR, mbuf NULL after IF_DEQUEUE"); CRIT_END; 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 */ PH_Data_Req(l2sc->unit, 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; CRIT_END; if(l2sc->T200 == TIMER_IDLE) { i4b_T203_stop(l2sc); i4b_T200_start(l2sc); } } #endif /* NI4BQ921 > 0 */