From 7a56952307a0d1ff673900e68a73a0a961b5197c Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Sun, 2 Jun 2019 22:37:21 +0200 Subject: lapd_core: Perform N200 retransmissions, not N200-1 During testing with BTS_Tests_LAPDm.TC_t200_n200() it was discovered that the existing LAPD[m] implementation always gave up at N200-1 retransmissions, rather than N200 retransmissions. The first transmission doesn't count, and hence we must have N200 actual re-transmissions. The Error message is then described as "T200 expired N200+1 times", i.e. we start T200 one more time after the last re-transmission and only give up if it expires again (i.e. no ACK received) Change-Id: Ic33854ee61311f73b7db55eeef10280349151097 Related: OS4037 --- src/gsm/lapd_core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/gsm/lapd_core.c b/src/gsm/lapd_core.c index a2ff2301..19dff4f0 100644 --- a/src/gsm/lapd_core.c +++ b/src/gsm/lapd_core.c @@ -564,7 +564,7 @@ static void lapd_t200_cb(void *data) switch (dl->state) { case LAPD_STATE_SABM_SENT: /* 5.4.1.3 */ - if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) { + if (dl->retrans_ctr >= dl->n200_est_rel + 1) { /* flush tx and send buffers */ lapd_dl_flush_tx(dl); lapd_dl_flush_send(dl); @@ -589,7 +589,7 @@ static void lapd_t200_cb(void *data) break; case LAPD_STATE_DISC_SENT: /* 5.4.4.3 */ - if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) { + if (dl->retrans_ctr >= dl->n200_est_rel + 1) { /* send MDL ERROR INIDCATION to L3 */ mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx); /* send RELEASE INDICATION to L3 */ @@ -618,7 +618,7 @@ static void lapd_t200_cb(void *data) /* fall through */ case LAPD_STATE_TIMER_RECOV: dl->retrans_ctr++; - if (dl->retrans_ctr < dl->n200) { + if (dl->retrans_ctr <= dl->n200) { uint8_t vs = sub_mod(dl->v_send, 1, dl->v_range); uint8_t h = do_mod(vs, dl->range_hist); /* retransmit I frame (V_s-1) with P=1, if any */ @@ -671,7 +671,7 @@ static void lapd_t200_cb(void *data) /* reestablish */ if (!dl->reestablish) break; - LOGP(DLLAPD, LOGL_NOTICE, "N200 reached, performing " + LOGP(DLLAPD, LOGL_NOTICE, "N200+1 reached, performing " "reestablishment. (dl=%p)\n", dl); lapd_reestablish(dl); } -- cgit v1.2.3