/* (C) 2014 by sysmocom s.f.m.c. GmbH
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define STI_BIT_MASK 16
static int check_fom(struct abis_om_hdr *omh, size_t len)
{
if (omh->length != len) {
LOGP(DL1C, LOGL_ERROR, "Incorrect OM hdr length value %d %zu\n",
omh->length, len);
return -1;
}
if (len < sizeof(struct abis_om_fom_hdr)) {
LOGP(DL1C, LOGL_ERROR, "FOM header insufficient space %zu %zu\n",
len, sizeof(struct abis_om_fom_hdr));
return -1;
}
return 0;
}
static int check_manuf(struct msgb *msg, struct abis_om_hdr *omh, size_t msg_size)
{
int type;
size_t size;
if (msg_size < 1) {
LOGP(DL1C, LOGL_ERROR, "No ManId Length Indicator %zu\n",
msg_size);
return -1;
}
if (omh->data[0] >= msg_size - 1) {
LOGP(DL1C, LOGL_ERROR,
"Insufficient message space for this ManId Length %d %zu\n",
omh->data[0], msg_size - 1);
return -1;
}
if (omh->data[0] == sizeof(abis_nm_ipa_magic) &&
strncmp(abis_nm_ipa_magic, (const char *)omh->data + 1,
sizeof(abis_nm_ipa_magic)) == 0) {
type = OML_MSG_TYPE_IPA;
size = sizeof(abis_nm_ipa_magic) + 1;
} else if (omh->data[0] == sizeof(abis_nm_osmo_magic) &&
strncmp(abis_nm_osmo_magic, (const char *) omh->data + 1,
sizeof(abis_nm_osmo_magic)) == 0) {
type = OML_MSG_TYPE_OSMO;
size = sizeof(abis_nm_osmo_magic) + 1;
} else {
LOGP(DL1C, LOGL_ERROR, "Manuf Label Unknown\n");
return -1;
}
/* we have verified that the vendor string fits */
msg->l3h = omh->data + size;
if (check_fom(omh, msgb_l3len(msg)) != 0)
return -1;
return type;
}
/* check that DTX is in the middle of silence */
static inline bool dtx_is_update(const struct gsm_lchan *lchan)
{
if (!dtx_dl_amr_enabled(lchan))
return false;
if (lchan->tch.dtx.dl_amr_fsm->state == ST_SID_U ||
lchan->tch.dtx.dl_amr_fsm->state == ST_U_NOINH)
return true;
return false;
}
/* check that DTX is in the beginning of silence for AMR HR */
bool dtx_is_first_p1(const struct gsm_lchan *lchan)
{
if (!dtx_dl_amr_enabled(lchan))
return false;
if ((lchan->type == GSM_LCHAN_TCH_H &&
lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F1))
return true;
return false;
}
/* update lchan SID status */
void lchan_set_marker(bool t, struct gsm_lchan *lchan)
{
if (t)
lchan->tch.dtx.ul_sid = true;
else if (lchan->tch.dtx.ul_sid) {
lchan->tch.dtx.ul_sid = false;
lchan->rtp_tx_marker = true;
}
}
/*! \brief Store the last SID frame in lchan context
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] l1_payload buffer with SID data
* \param[in] length length of l1_payload
* \param[in] fn Frame Number for which we check scheduling
* \param[in] update 0 if SID_FIRST, 1 if SID_UPDATE, -1 if not AMR SID
*/
void dtx_cache_payload(struct gsm_lchan *lchan, const uint8_t *l1_payload,
size_t length, uint32_t fn, int update)
{
size_t amr = (update < 0) ? 0 : 2,
copy_len = OSMO_MIN(length,
ARRAY_SIZE(lchan->tch.dtx.cache) - amr);
lchan->tch.dtx.len = copy_len + amr;
/* SID FIRST is special because it's both sent and cached: */
if (update == 0) {
lchan->tch.dtx.is_update = false; /* Mark SID FIRST explicitly */
/* for non-AMR case - always update FN for incoming SID FIRST */
if (!amr || !dtx_is_update(lchan))
lchan->tch.dtx.fn = fn;
/* for AMR case - do not update FN if SID FIRST arrives in a
middle of silence: this should not be happening according to
the spec */
}
memcpy(lchan->tch.dtx.cache + amr, l1_payload, copy_len);
}
/*! \brief Check current state of DTX DL AMR FSM and dispatch necessary events
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] rtp_pl buffer with RTP data
* \param[in] rtp_pl_len length of rtp_pl
* \param[in] fn Frame Number for which we check scheduling
* \param[in] l1_payload buffer where CMR and CMI prefix should be added
* \param[in] marker RTP Marker bit
* \param[out] len Length of expected L1 payload
* \param[out] ft_out Frame Type to be populated after decoding
* \returns 0 in case of success; negative on error
*/
int dtx_dl_amr_fsm_step(struct gsm_lchan *lchan, const uint8_t *rtp_pl,
size_t rtp_pl_len, uint32_t fn, uint8_t *l1_payload,
bool marker, uint8_t *len, uint8_t *ft_out)
{
uint8_t cmr;
enum osmo_amr_type ft;
enum osmo_amr_quality bfi;
int8_t sti, cmi;
int rc;
if (dtx_dl_amr_enabled(lchan)) {
if (lchan->type == GSM_LCHAN_TCH_H && !rtp_pl) {
/* we're called by gen_empty_tch_msg() to handle states
specific to AMR HR DTX */
switch (lchan->tch.dtx.dl_amr_fsm->state) {
case ST_SID_F2:
*len = 3; /* SID-FIRST P1 -> P2 completion */
memcpy(l1_payload, lchan->tch.dtx.cache, 2);
rc = 0;
dtx_dispatch(lchan, E_COMPL);
break;
case ST_SID_U:
rc = -EBADMSG;
dtx_dispatch(lchan, E_SID_U);
break;
default:
rc = -EBADMSG;
}
return rc;
}
}
if (!rtp_pl_len)
return -EBADMSG;
rc = osmo_amr_rtp_dec(rtp_pl, rtp_pl_len, &cmr, &cmi, &ft, &bfi, &sti);
if (rc < 0) {
LOGPLCHAN(lchan, DRTP, LOGL_ERROR, "failed to decode AMR RTP (length %zu, "
"%p)\n", rtp_pl_len, rtp_pl);
return rc;
}
/* only needed for old sysmo firmware: */
*ft_out = ft;
/* CMI in downlink tells the L1 encoder which encoding function
* it will use, so we have to use the frame type */
if (osmo_amr_is_speech(ft))
cmi = ft;
/* populate L1 payload with CMR/CMI - might be ignored by caller: */
amr_set_mode_pref(l1_payload, &lchan->tch.amr_mr, cmi, cmr);
/* populate DTX cache with CMR/CMI - overwrite cache which will be
either updated or invalidated by caller anyway: */
amr_set_mode_pref(lchan->tch.dtx.cache, &lchan->tch.amr_mr, cmi, cmr);
*len = 3 + rtp_pl_len;
/* DTX DL is not enabled, move along */
if (!lchan->ts->trx->bts->dtxd)
return 0;
if (osmo_amr_is_speech(ft)) {
/* AMR HR - SID-FIRST_P1 Inhibition */
if (marker && lchan->tch.dtx.dl_amr_fsm->state == ST_VOICE)
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_INHIB, (void *)lchan);
/* AMR HR - SID-UPDATE Inhibition */
if (marker && lchan->type == GSM_LCHAN_TCH_H &&
lchan->tch.dtx.dl_amr_fsm->state == ST_SID_U)
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_INHIB, (void *)lchan);
/* AMR FR & HR - generic */
if (marker && (lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F1 ||
lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F2 ||
lchan->tch.dtx.dl_amr_fsm->state == ST_U_NOINH))
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_ONSET, (void *)lchan);
if (lchan->tch.dtx.dl_amr_fsm->state != ST_VOICE)
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_VOICE, (void *)lchan);
return 0;
}
if (ft == AMR_SID) {
if (lchan->tch.dtx.dl_amr_fsm->state == ST_VOICE) {
/* SID FIRST/UPDATE scheduling logic relies on SID FIRST
being sent first hence we have to force caching of SID
as FIRST regardless of actually decoded type */
dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, false);
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
sti ? E_SID_U : E_SID_F,
(void *)lchan);
} else if (lchan->tch.dtx.dl_amr_fsm->state != ST_FACCH)
dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, sti);
if (lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F2)
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_COMPL, (void *)lchan);
return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
sti ? E_SID_U : E_SID_F,
(void *)lchan);
}
if (ft != AMR_NO_DATA) {
LOGPLCHAN(lchan, DRTP, LOGL_ERROR, "unsupported AMR FT 0x%02x\n", ft);
return -ENOTSUP;
}
if (marker)
osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm, E_VOICE,
(void *)lchan);
*len = 0;
return 0;
}
/* STI is located in payload byte 6, cache contains 2 byte prefix (CMR/CMI)
* STI set = SID UPDATE, STI unset = SID FIRST
*/
static inline void dtx_sti_set(struct gsm_lchan *lchan)
{
lchan->tch.dtx.cache[6 + 2] |= STI_BIT_MASK;
}
static inline void dtx_sti_unset(struct gsm_lchan *lchan)
{
lchan->tch.dtx.cache[6 + 2] &= ~STI_BIT_MASK;
}
/*! \brief Check if enough time has passed since last SID (if any) to repeat it
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] fn Frame Number for which we check scheduling
* \returns true if transmission can be omitted, false otherwise
*/
static inline bool dtx_amr_sid_optional(struct gsm_lchan *lchan, uint32_t fn)
{
if (!dtx_dl_amr_enabled(lchan))
return true;
/* Compute approx. time delta x26 based on Fn duration */
uint32_t dx26 = 120 * (fn - lchan->tch.dtx.fn);
/* We're resuming after FACCH interruption */
if (lchan->tch.dtx.dl_amr_fsm->state == ST_FACCH) {
/* force STI bit to 0 so cache is treated as SID FIRST */
dtx_sti_unset(lchan);
lchan->tch.dtx.is_update = false;
/* check that this FN has not been used for FACCH message
already: we rely here on the order of RTS arrival from L1 - we
expect that PH-DATA.req ALWAYS comes before PH-TCH.req for the
same FN */
if (lchan->type == GSM_LCHAN_TCH_H) {
if (lchan->tch.dtx.fn != LCHAN_FN_DUMMY &&
lchan->tch.dtx.fn != LCHAN_FN_WAIT) {
/* FACCH interruption is over */
dtx_dispatch(lchan, E_COMPL);
return false;
} else if (lchan->tch.dtx.fn == LCHAN_FN_DUMMY) {
lchan->tch.dtx.fn = LCHAN_FN_WAIT;
} else
lchan->tch.dtx.fn = fn;
} else if (lchan->type == GSM_LCHAN_TCH_F) {
if (lchan->tch.dtx.fn != LCHAN_FN_DUMMY) {
/* FACCH interruption is over */
dtx_dispatch(lchan, E_COMPL);
return false;
} else
lchan->tch.dtx.fn = fn;
}
/* this FN was already used for FACCH or ONSET message so we just
prepare things for next one */
return true;
}
if (lchan->tch.dtx.dl_amr_fsm->state == ST_VOICE)
return true;
/* according to 3GPP TS 26.093 A.5.1.1:
(*26) to avoid float math, add 1 FN tolerance (-120) */
if (lchan->tch.dtx.is_update) { /* SID UPDATE: every 8th RTP frame */
if (dx26 < GSM_RTP_FRAME_DURATION_MS * 8 * 26 - 120)
return true;
return false;
}
/* 3rd frame after SID FIRST should be SID UPDATE */
if (dx26 < GSM_RTP_FRAME_DURATION_MS * 3 * 26 - 120)
return true;
return false;
}
static inline bool fn_chk(const uint8_t *t, uint32_t fn, uint8_t len)
{
uint8_t i;
for (i = 0; i < len; i++)
if (fn % 104 == t[i])
return false;
return true;
}
/*! \brief Check if TX scheduling is optional for a given FN in case of DTX
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] fn Frame Number for which we check scheduling
* \returns true if transmission can be omitted, false otherwise
*/
static inline bool dtx_sched_optional(struct gsm_lchan *lchan, uint32_t fn)
{
/* According to 3GPP TS 45.008 ยง 8.3: */
static const uint8_t f[] = { 52, 53, 54, 55, 56, 57, 58, 59 },
h0[] = { 0, 2, 4, 6, 52, 54, 56, 58 },
h1[] = { 14, 16, 18, 20, 66, 68, 70, 72 };
switch (lchan->tch_mode) {
case GSM48_CMODE_SPEECH_V1:
if (lchan->type == GSM_LCHAN_TCH_F)
return fn_chk(f, fn, ARRAY_SIZE(f));
else
return fn_chk(lchan->nr ? h1 : h0, fn,
lchan->nr ? ARRAY_SIZE(h1) :
ARRAY_SIZE(h0));
case GSM48_CMODE_SPEECH_EFR:
return fn_chk(f, fn, ARRAY_SIZE(f));
default:
return false;
}
}
/*! \brief Check if DTX DL AMR is enabled for a given lchan (it have proper type,
* FSM is allocated etc.)
* \param[in] lchan Logical channel on which we check scheduling
* \returns true if DTX DL AMR is enabled, false otherwise
*/
bool dtx_dl_amr_enabled(const struct gsm_lchan *lchan)
{
if (lchan->ts->trx->bts->dtxd &&
lchan->tch.dtx.dl_amr_fsm &&
lchan->tch_mode == GSM48_CMODE_SPEECH_AMR)
return true;
return false;
}
/*! \brief Check if DTX DL AMR FSM state is recursive: requires secondary
* response to a single RTS request from L1.
* \param[in] lchan Logical channel on which we check scheduling
* \returns true if DTX DL AMR FSM state is recursive, false otherwise
*/
bool dtx_recursion(const struct gsm_lchan *lchan)
{
if (!dtx_dl_amr_enabled(lchan))
return false;
if (lchan->tch.dtx.dl_amr_fsm->state == ST_U_INH_V ||
lchan->tch.dtx.dl_amr_fsm->state == ST_U_INH_F ||
lchan->tch.dtx.dl_amr_fsm->state == ST_U_INH_V_REC ||
lchan->tch.dtx.dl_amr_fsm->state == ST_U_INH_F_REC ||
lchan->tch.dtx.dl_amr_fsm->state == ST_F1_INH_V ||
lchan->tch.dtx.dl_amr_fsm->state == ST_F1_INH_F ||
lchan->tch.dtx.dl_amr_fsm->state == ST_F1_INH_V_REC ||
lchan->tch.dtx.dl_amr_fsm->state == ST_F1_INH_F_REC ||
lchan->tch.dtx.dl_amr_fsm->state == ST_ONSET_F ||
lchan->tch.dtx.dl_amr_fsm->state == ST_ONSET_V ||
lchan->tch.dtx.dl_amr_fsm->state == ST_ONSET_F_REC ||
lchan->tch.dtx.dl_amr_fsm->state == ST_ONSET_V_REC)
return true;
return false;
}
/*! \brief Send signal to FSM: with proper check if DIX is enabled for this lchan
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] e DTX DL AMR FSM Event
*/
void dtx_dispatch(struct gsm_lchan *lchan, enum dtx_dl_amr_fsm_events e)
{
if (dtx_dl_amr_enabled(lchan))
osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm, e,
(void *)lchan);
}
/*! \brief Send internal signal to FSM: check that DTX is enabled for this chan,
* check that current FSM and lchan states are permitting such signal.
* Note: this should be the only way to dispatch E_COMPL to FSM from
* BTS code.
* \param[in] lchan Logical channel on which we check scheduling
*/
void dtx_int_signal(struct gsm_lchan *lchan)
{
if (!dtx_dl_amr_enabled(lchan))
return;
if (dtx_is_first_p1(lchan) || dtx_recursion(lchan))
dtx_dispatch(lchan, E_COMPL);
}
/*! \brief Repeat last SID if possible in case of DTX
* \param[in] lchan Logical channel on which we check scheduling
* \param[in] dst Buffer to copy last SID into
* \returns Number of bytes copied + 1 (to accommodate for extra byte with
* payload type), 0 if there's nothing to copy
*/
uint8_t repeat_last_sid(struct gsm_lchan *lchan, uint8_t *dst, uint32_t fn)
{
if (lchan->tch_mode != GSM48_CMODE_SPEECH_AMR) {
if (dtx_sched_optional(lchan, fn))
return 0;
} else
if (dtx_amr_sid_optional(lchan, fn))
return 0;
if (lchan->tch.dtx.len) {
if (dtx_dl_amr_enabled(lchan)) {
if ((lchan->type == GSM_LCHAN_TCH_H &&
lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F2) ||
(lchan->type == GSM_LCHAN_TCH_F &&
lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F1)) {
/* advance FSM in case we've just sent SID FIRST
to restore silence after FACCH interruption */
osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_SID_U, (void *)lchan);
dtx_sti_unset(lchan);
} else if (dtx_is_update(lchan)) {
/* enforce SID UPDATE for next repetition: it
might have been altered by FACCH handling */
dtx_sti_set(lchan);
if (lchan->type == GSM_LCHAN_TCH_H &&
lchan->tch.dtx.dl_amr_fsm->state ==
ST_U_NOINH)
osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
E_COMPL,
(void *)lchan);
lchan->tch.dtx.is_update = true;
}
}
memcpy(dst, lchan->tch.dtx.cache, lchan->tch.dtx.len);
lchan->tch.dtx.fn = fn;
return lchan->tch.dtx.len + 1;
}
LOGPLCHAN(lchan, DL1C, LOGL_DEBUG, "Have to send %s frame on TCH but SID buffer "
"is empty - sent nothing\n",
get_value_string(gsm48_chan_mode_names, lchan->tch_mode));
return 0;
}
/**
* Return 0 in case the IPA structure is okay and in this
* case the l2h will be set to the beginning of the data.
*/
int msg_verify_ipa_structure(struct msgb *msg)
{
struct ipaccess_head *hh;
if (msgb_l1len(msg) < sizeof(struct ipaccess_head)) {
LOGP(DL1C, LOGL_ERROR,
"Ipa header insufficient space %d %zu\n",
msgb_l1len(msg), sizeof(struct ipaccess_head));
return -1;
}
hh = (struct ipaccess_head *) msg->l1h;
if (ntohs(hh->len) != msgb_l1len(msg) - sizeof(struct ipaccess_head)) {
LOGP(DL1C, LOGL_ERROR,
"Incorrect ipa header msg size %d %zu\n",
ntohs(hh->len), msgb_l1len(msg) - sizeof(struct ipaccess_head));
return -1;
}
if (hh->proto == IPAC_PROTO_OSMO) {
struct ipaccess_head_ext *hh_ext = (struct ipaccess_head_ext *) hh->data;
if (ntohs(hh->len) < sizeof(*hh_ext)) {
LOGP(DL1C, LOGL_ERROR, "IPA length shorter than OSMO header\n");
return -1;
}
msg->l2h = hh_ext->data;
} else
msg->l2h = hh->data;
return 0;
}
/**
* \brief Verify the structure of the OML message and set l3h
*
* This function verifies that the data in \param in msg is a proper
* OML message. This code assumes that msg->l2h points to the
* beginning of the OML message. In the successful case the msg->l3h
* will be set and will point to the FOM header. The value is undefined
* in all other cases.
*
* \param msg The message to analyze starting from msg->l2h.
* \return In case the structure is correct a positive number will be
* returned and msg->l3h will point to the FOM. The number is a
* classification of the vendor type of the message.
*/
int msg_verify_oml_structure(struct msgb *msg)
{
struct abis_om_hdr *omh;
if (msgb_l2len(msg) < sizeof(*omh)) {
LOGP(DL1C, LOGL_ERROR, "Om header insufficient space %d %zu\n",
msgb_l2len(msg), sizeof(*omh));
return -1;
}
omh = (struct abis_om_hdr *) msg->l2h;
if (omh->mdisc != ABIS_OM_MDISC_FOM &&
omh->mdisc != ABIS_OM_MDISC_MANUF) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om mdisc value %x\n",
omh->mdisc);
return -1;
}
if (omh->placement != ABIS_OM_PLACEMENT_ONLY) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om placement value %x %x\n",
omh->placement, ABIS_OM_PLACEMENT_ONLY);
return -1;
}
if (omh->sequence != 0) {
LOGP(DL1C, LOGL_ERROR, "Incorrect om sequence value %d\n",
omh->sequence);
return -1;
}
if (omh->mdisc == ABIS_OM_MDISC_MANUF)
return check_manuf(msg, omh, msgb_l2len(msg) - sizeof(*omh));
msg->l3h = omh->data;
if (check_fom(omh, msgb_l3len(msg)) != 0)
return -1;
return OML_MSG_TYPE_ETSI;
}