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sysmobts: Re-order the bit-endianness of every HR codec parameter 

The so-called "RTP mode" of the DSP contains a bug on all firmware
versions < 5.3.3 which causes the bit-order within each of the
non-aligned codec parameters to be wrong.  Introduce a function
originally written by Sylvain Munaut during 32C3 in
http://git.osmocom.org/openbsc/commit/?h=sylvain/32c3_codec&id=5b4a16bbe93a7b1ace65cc23d6cce56ecf4f1275
to bring the bits into [the correct] order.

This has never been seen in a "pure sysmoBTS" setup, as all BTSs would
use the same (wrong) bit-ordering and thus interoperate.  This patch now
checks for an affected DSP firmware version and then jumbles (old DSP
firmware version) or does nothing (new DSP firmware version).

Change-Id: Ia0eee4f514fb8fd81c052bb44a4facba898d6afb
Closes: SYS#2452
This commit is contained in:
Harald Welte 2017-05-28 16:00:36 +02:00
parent cb5a969a45
commit a8bf666a09
3 changed files with 57 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/osmo-bts-sysmo/l1_if.c
View File

@ -1460,6 +1460,9 @@ static int info_compl_cb(struct gsm_bts_trx *trx, struct msgb *resp,
LOGP(DL1C, LOGL_FATAL, "BTS band %s not supported by hw\n",
gsm_band_name(trx->bts->band));
if (l1if_dsp_ver(fl1h) < L1_VER_SHIFT(5,3,3))
fl1h->rtp_hr_jumble_needed = true;
/* Request the activation */
l1if_activate_rf(fl1h, 1);

1
src/osmo-bts-sysmo/l1_if.h
View File

@ -74,6 +74,7 @@ struct femtol1_hdl {
} hw_info;
int fixup_needed;
bool rtp_hr_jumble_needed;
struct calib_send_state st;

59
src/osmo-bts-sysmo/tch.c
View File

@ -157,6 +157,43 @@ static int rtppayload_to_l1_efr(uint8_t *l1_payload, const uint8_t *rtp_payload,
#warning No EFR support in L1
#endif /* L1_HAS_EFR */
#ifdef USE_L1_RTP_MODE
/* change the bit-order of each unaligned field inside the HR codec
* payload from little-endian bit-ordering to bit-endian and vice-versa.
* This is required on all sysmoBTS DSP versions < 5.3.3 in order to
* be compliant with ETSI TS 101 318 Chapter 5.2 */
static void hr_jumble(uint8_t *dst, const uint8_t *src)
{
/* Table 2 / Section 5.2.1 of ETSI TS 101 381 */
const int p_unvoiced[] =
{ 5, 11, 9, 8, 1, 2, 7, 7, 5, 7, 7, 5, 7, 7, 5, 7, 7, 5 };
/* Table 3 / Section 5.2.1 of ETSI TS 101 381 */
const int p_voiced[] =
{ 5, 11, 9, 8, 1, 2, 8, 9, 5, 4, 9, 5, 4, 9, 5, 4, 9, 5 };
int base, i, j, l, si, di;
const int *p;
memset(dst, 0x00, GSM_HR_BYTES);
p = (src[4] & 0x30) ? p_voiced : p_unvoiced;
base = 0;
for (i = 0; i < 18; i++) {
l = p[i];
for (j = 0; j < l; j++) {
si = base + j;
di = base + l - j - 1;
if (src[si >> 3] & (1 << (7 - (si & 7))))
dst[di >> 3] |= (1 << (7 - (di & 7)));
}
base += l;
}
}
#endif /* USE_L1_RTP_MODE */
static struct msgb *l1_to_rtppayload_hr(uint8_t *l1_payload, uint8_t payload_len,
struct gsm_lchan *lchan)
{
@ -174,9 +211,14 @@ static struct msgb *l1_to_rtppayload_hr(uint8_t *l1_payload, uint8_t payload_len
}
cur = msgb_put(msg, GSM_HR_BYTES);
#ifdef USE_L1_RTP_MODE
struct femtol1_hdl *fl1h = trx_femtol1_hdl(lchan->ts->trx);
if (fl1h->rtp_hr_jumble_needed)
hr_jumble(cur, l1_payload);
else
memcpy(cur, l1_payload, GSM_HR_BYTES);
#else /* USE_L1_RTP_MODE */
memcpy(cur, l1_payload, GSM_HR_BYTES);
#ifndef USE_L1_RTP_MODE
/* reverse the bit-order of each payload byte */
osmo_revbytebits_buf(cur, GSM_HR_BYTES);
#endif /* USE_L1_RTP_MODE */
@ -193,7 +235,7 @@ static struct msgb *l1_to_rtppayload_hr(uint8_t *l1_payload, uint8_t payload_len
* \returns number of \a l1_payload bytes filled
*/
static int rtppayload_to_l1_hr(uint8_t *l1_payload, const uint8_t *rtp_payload,
unsigned int payload_len)
unsigned int payload_len, struct gsm_lchan *lchan)
{
if (payload_len != GSM_HR_BYTES) {
@ -202,9 +244,14 @@ static int rtppayload_to_l1_hr(uint8_t *l1_payload, const uint8_t *rtp_payload,
return 0;
}
#ifdef USE_L1_RTP_MODE
struct femtol1_hdl *fl1h = trx_femtol1_hdl(lchan->ts->trx);
if (fl1h->rtp_hr_jumble_needed)
hr_jumble(l1_payload, rtp_payload);
else
memcpy(l1_payload, rtp_payload, GSM_HR_BYTES);
#else /* USE_L1_RTP_MODE */
memcpy(l1_payload, rtp_payload, GSM_HR_BYTES);
#ifndef USE_L1_RTP_MODE
/* reverse the bit-order of each payload byte */
osmo_revbytebits_buf(l1_payload, GSM_HR_BYTES);
#endif /* USE_L1_RTP_MODE */
@ -345,7 +392,7 @@ int l1if_tch_encode(struct gsm_lchan *lchan, uint8_t *data, uint8_t *len,
} else{
*payload_type = GsmL1_TchPlType_Hr;
rc = rtppayload_to_l1_hr(l1_payload,
rtp_pl, rtp_pl_len);
rtp_pl, rtp_pl_len, lchan);
if (rc && lchan->ts->trx->bts->dtxd)
is_sid = osmo_hr_check_sid(rtp_pl, rtp_pl_len);
}