diff options
| author | Pau Espin Pedrol <pespin@sysmocom.de> | 2023-05-31 19:36:41 +0200 |
|---|---|---|
| committer | Pau Espin Pedrol <pespin@sysmocom.de> | 2023-05-31 20:49:56 +0200 |
| commit | f09056de4648fdf942dd564f70387de5be244964 (patch) | |
| tree | 6721f4aadaeb19e86c25513cfad204a8385a9cda | |
| parent | 33cb3d61756834d404b68f537e208d760b3473a8 (diff) | |
Error trying to obtain FN from RFN if curr_fn not known
This may happen if a RACH.ind is received before any DATA.ind has been
received.
With usual osmo-bts-trx or osmo-bts-sysmo, this shouldn't happen
nowadays, but it is still a problem with osmo-bts-virtual, where lower
layers don't submit NOPE.ind in the absence of data, and hence it won't
sent DATA.ind to osmo-pcu all the time.
This change helps in showcasing confusing scenarios where the RFN
generated in the Imm Ass was wrong.
Change-Id: I29b7ba828fe890f90e35686bbb04d4abfe56b955
| -rw-r--r-- | src/bts.cpp | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/bts.cpp b/src/bts.cpp index 8d6f1566..6cac93f5 100644 --- a/src/bts.cpp +++ b/src/bts.cpp @@ -740,20 +740,27 @@ int bts_rcv_imm_ass_cnf(struct gprs_rlcmac_bts *bts, const uint8_t *data, uint32 /* Determine the full frame number from a relative frame number */ uint32_t bts_rfn_to_fn(const struct gprs_rlcmac_bts *bts, uint32_t rfn) { - uint32_t m_cur_rfn; + uint32_t m_cur_fn, m_cur_rfn; uint32_t fn_rounded; /* Ensure that all following calculations are performed with the * relative frame number */ OSMO_ASSERT(rfn < RFN_MODULUS); + m_cur_fn = bts_current_frame_number(bts); + if (m_cur_fn == FN_UNSET) { + LOGP(DRLCMAC, LOGL_ERROR, "Unable to calculate full FN from RFN %u: Current FN not known!\n", + rfn); + return rfn; + } + /* Compute an internal relative frame number from the full internal frame number */ - m_cur_rfn = fn2rfn(bts->cur_fn); + m_cur_rfn = fn2rfn(m_cur_fn); /* Compute a "rounded" version of the internal frame number, which * exactly fits in the RFN_MODULUS raster */ - fn_rounded = GSM_TDMA_FN_SUB(bts->cur_fn, m_cur_rfn); + fn_rounded = GSM_TDMA_FN_SUB(m_cur_fn, m_cur_rfn); /* If the delta between the internal and the external relative frame * number exceeds a certain limit, we need to assume that the incoming @@ -762,7 +769,7 @@ uint32_t bts_rfn_to_fn(const struct gprs_rlcmac_bts *bts, uint32_t rfn) if (GSM_TDMA_FN_DIFF(rfn, m_cur_rfn) > RFN_THRESHOLD) { LOGP(DRLCMAC, LOGL_DEBUG, "Race condition between rfn (%u) and m_cur_fn (%u) detected: rfn belongs to the previous modulus %u cycle, wrapping...\n", - rfn, bts->cur_fn, RFN_MODULUS); + rfn, m_cur_fn, RFN_MODULUS); if (fn_rounded < RFN_MODULUS) { LOGP(DRLCMAC, LOGL_DEBUG, "Cornercase detected: wrapping crosses %u border\n", |