fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/27755 )

Change subject: rsl: parse_multirate_config(): check if AMR codec is used ......................................................................

rsl: parse_multirate_config(): check if AMR codec is used

3GPP TS 48.058 defines the MultiRate configuration IE as optional, and states that it's "included if the Channel Mode indicates that a multi-rate codec is used". If I understand this correctly, it may be omitted even if a multi-rate codec is requested. Otherwise it would have been defined as a conditional IE.

For now let's print a warnig if this IE was expected, but missing. We may need to apply some hard-coded defaults in this case.

If this IE is present, but the Channel Mode indicates a codec other than AMR, let's send NACK with cause=RSL_ERR_OPT_IE_ERROR, assuming that the CHAN ACT/MODIFY message is malformed.

Change-Id: I6ddc0b46a268ed56ac727cda57d0d68b2746fd59 Related: SYS#5917, OS#4984 --- M src/common/rsl.c 1 file changed, 15 insertions(+), 1 deletion(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/55/27755/1

diff --git a/src/common/rsl.c b/src/common/rsl.c index 2da954d..961e065 100644 --- a/src/common/rsl.c +++ b/src/common/rsl.c @@ -1623,8 +1623,22 @@ { int rc;

- if (!TLVP_PRESENT(tp, RSL_IE_MR_CONFIG)) + if (!TLVP_PRESENT(tp, RSL_IE_MR_CONFIG)) { + /* Included if the Channel Mode indicates that a multi-rate codec is used */ + if (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) { + LOGPLCHAN(lchan, DRSL, LOGL_NOTICE, "Missing MultiRate conf IE " + "(TCH mode is %s)\n", gsm48_chan_mode_name(lchan->tch_mode)); + /* TODO: init lchan->tch.amr_mr with some default values */ + } return 0; + } + + /* Included if the Channel Mode indicates that a multi-rate codec is used */ + if (lchan->tch_mode != GSM48_CMODE_SPEECH_AMR) { + LOGPLCHAN(lchan, DRSL, LOGL_ERROR, "Unexpected MultiRate conf IE " + "(TCH mode is %s)\n", gsm48_chan_mode_name(lchan->tch_mode)); + return -RSL_ERR_OPT_IE_ERROR; + }

rc = amr_parse_mr_conf(&lchan->tch.amr_mr, TLVP_VAL(tp, RSL_IE_MR_CONFIG),