<p>Harald Welte has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/14347">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">lapd_core: Perform N200 retransmissions, not N200-1<br><br>During testing with BTS_Tests_LAPDm.TC_t200_n200() it was discovered<br>that the existing LAPD[m] implementation always gave up at N200-1<br>retransmissions, rather than N200 retransmissions.<br><br>The first transmission doesn't count, and hence we must have N200<br>actual re-transmissions.  The Error message is then described as<br>"T200 expired N200+1 times", i.e. we start T200 one more time after<br>the last re-transmission and only give up if it expires again (i.e.<br>no ACK received)<br><br>Change-Id: Ic33854ee61311f73b7db55eeef10280349151097<br>Related: OS4037<br>---<br>M src/gsm/lapd_core.c<br>1 file changed, 4 insertions(+), 4 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/47/14347/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/gsm/lapd_core.c b/src/gsm/lapd_core.c</span><br><span>index a2ff230..19dff4f 100644</span><br><span>--- a/src/gsm/lapd_core.c</span><br><span>+++ b/src/gsm/lapd_core.c</span><br><span>@@ -564,7 +564,7 @@</span><br><span>       switch (dl->state) {</span><br><span>      case LAPD_STATE_SABM_SENT:</span><br><span>           /* 5.4.1.3 */</span><br><span style="color: hsl(0, 100%, 40%);">-           if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) {</span><br><span style="color: hsl(120, 100%, 40%);">+           if (dl->retrans_ctr >= dl->n200_est_rel + 1) {</span><br><span>                      /* flush tx and send buffers */</span><br><span>                      lapd_dl_flush_tx(dl);</span><br><span>                        lapd_dl_flush_send(dl);</span><br><span>@@ -589,7 +589,7 @@</span><br><span>                break;</span><br><span>       case LAPD_STATE_DISC_SENT:</span><br><span>           /* 5.4.4.3 */</span><br><span style="color: hsl(0, 100%, 40%);">-           if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) {</span><br><span style="color: hsl(120, 100%, 40%);">+           if (dl->retrans_ctr >= dl->n200_est_rel + 1) {</span><br><span>                      /* send MDL ERROR INIDCATION to L3 */</span><br><span>                        mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);</span><br><span>                         /* send RELEASE INDICATION to L3 */</span><br><span>@@ -618,7 +618,7 @@</span><br><span>            /* fall through */</span><br><span>   case LAPD_STATE_TIMER_RECOV:</span><br><span>                 dl->retrans_ctr++;</span><br><span style="color: hsl(0, 100%, 40%);">-           if (dl->retrans_ctr < dl->n200) {</span><br><span style="color: hsl(120, 100%, 40%);">+            if (dl->retrans_ctr <= dl->n200) {</span><br><span>                  uint8_t vs = sub_mod(dl->v_send, 1, dl->v_range);</span><br><span>                      uint8_t h = do_mod(vs, dl->range_hist);</span><br><span>                   /* retransmit I frame (V_s-1) with P=1, if any */</span><br><span>@@ -671,7 +671,7 @@</span><br><span>                      /* reestablish */</span><br><span>                    if (!dl->reestablish)</span><br><span>                             break;</span><br><span style="color: hsl(0, 100%, 40%);">-                  LOGP(DLLAPD, LOGL_NOTICE, "N200 reached, performing "</span><br><span style="color: hsl(120, 100%, 40%);">+                       LOGP(DLLAPD, LOGL_NOTICE, "N200+1 reached, performing "</span><br><span>                            "reestablishment. (dl=%p)\n", dl);</span><br><span>                         lapd_reestablish(dl);</span><br><span>                }</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/14347">change 14347</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/libosmocore/+/14347"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: Ic33854ee61311f73b7db55eeef10280349151097 </div>
<div style="display:none"> Gerrit-Change-Number: 14347 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Harald Welte <laforge@gnumonks.org> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>