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#include <osmocom/gsm/protocol/gsm_08_08.h>
#include <osmocom/msc/cc_sdp.h>
#include <osmocom/msc/codec_sdp_cc_t9n.h>
#include <osmocom/msc/debug.h>
/* Add all known payload types encountered in GSM networks */
static void sdp_add_all_mobile_codecs(struct sdp_audio_codecs *ac)
{
/* In order of preference. TODO: make configurable */
static const enum gsm48_bcap_speech_ver mobile_codecs[] = {
GSM48_BCAP_SV_AMR_F /*!< 4 GSM FR V3 (FR AMR) */,
GSM48_BCAP_SV_AMR_H /*!< 5 GSM HR V3 (HR_AMR) */,
GSM48_BCAP_SV_EFR /*!< 2 GSM FR V2 (GSM EFR) */,
GSM48_BCAP_SV_FR /*!< 0 GSM FR V1 (GSM FR) */,
GSM48_BCAP_SV_HR /*!< 1 GSM HR V1 (GSM HR) */,
};
int i;
for (i = 0; i < ARRAY_SIZE(mobile_codecs); i++)
sdp_audio_codecs_add_speech_ver(ac, mobile_codecs[i]);
}
/* Add all known AMR payload types encountered in UTRAN networks */
static void sdp_add_all_utran_codecs(struct sdp_audio_codecs *ac)
{
/* In order of preference. TODO: make configurable */
static const enum gsm48_bcap_speech_ver utran_codecs[] = {
GSM48_BCAP_SV_AMR_F /*!< 4 GSM FR V3 (FR AMR) */,
GSM48_BCAP_SV_AMR_H /*!< 5 GSM HR V3 (HR_AMR) */,
GSM48_BCAP_SV_AMR_OH /*!< 11 GSM HR V6 (OHR AMR) */,
GSM48_BCAP_SV_AMR_FW /*!< 8 GSM FR V5 (FR AMR-WB) */,
GSM48_BCAP_SV_AMR_OFW /*!< 6 GSM FR V4 (OFR AMR-WB) */,
GSM48_BCAP_SV_AMR_OHW /*!< 7 GSM HR V4 (OHR AMR-WB) */,
};
int i;
for (i = 0; i < ARRAY_SIZE(utran_codecs); i++)
sdp_audio_codecs_add_speech_ver(ac, utran_codecs[i]);
}
static void cc_sdp_set_ran(struct cc_sdp *cc_sdp, enum osmo_rat_type ran_type)
{
cc_sdp->ran = (struct sdp_audio_codecs){};
switch (ran_type) {
default:
case OSMO_RAT_GERAN_A:
sdp_add_all_mobile_codecs(&cc_sdp->ran);
break;
case OSMO_RAT_UTRAN_IU:
sdp_add_all_utran_codecs(&cc_sdp->ran);
break;
}
}
void cc_sdp_init(struct cc_sdp *cc_sdp,
enum osmo_rat_type ran_type,
const struct gsm_mncc_bearer_cap *ms_bearer_cap,
const struct gsm0808_speech_codec_list *codec_list_bss_supported)
{
*cc_sdp = (struct cc_sdp){};
cc_sdp_set_ran(cc_sdp, ran_type);
if (ms_bearer_cap)
sdp_audio_codecs_from_bearer_cap(&cc_sdp->ms, ms_bearer_cap);
if (codec_list_bss_supported)
cc_sdp_set_cell(cc_sdp, codec_list_bss_supported);
}
void cc_sdp_set_cell(struct cc_sdp *cc_sdp,
const struct gsm0808_speech_codec_list *codec_list_bss_supported)
{
cc_sdp->cell = (struct sdp_audio_codecs){};
if (codec_list_bss_supported)
sdp_audio_codecs_from_speech_codec_list(&cc_sdp->cell, codec_list_bss_supported);
}
/* Render intersections of all known audio codec constraints to reach a resulting choice of favorite audio codec, plus
* possible set of alternative audio codecs, in cc_sdp->result. (The result.rtp address remains unchanged.) */
int cc_sdp_filter(struct cc_sdp *cc_sdp)
{
struct sdp_audio_codecs *r = &cc_sdp->result.audio_codecs;
struct sdp_audio_codec *a = &cc_sdp->assignment;
*r = cc_sdp->ran;
if (cc_sdp->ms.count)
sdp_audio_codecs_intersection(r, &cc_sdp->ms, false);
if (cc_sdp->cell.count)
sdp_audio_codecs_intersection(r, &cc_sdp->cell, false);
if (cc_sdp->remote.audio_codecs.count)
sdp_audio_codecs_intersection(r, &cc_sdp->remote.audio_codecs, true);
#if ALLOW_REASSIGNMENT
/* If osmo-msc were able to trigger a re-assignment after the remote side has picked a codec mismatching the
* initial Assignment, then this code here would make sense: keep the other codecs as available to choose from,
* but put the currently assigned codec in the first position. */
if (a->subtype_name[0]) {
/* Assignment has completed, the chosen codec should be the first of the resulting SDP.
* Make sure this is actually listed in the result SDP and move to first place. */
struct sdp_audio_codec *select = sdp_audio_codec_by_descr(r, a);
if (!select) {
/* Not present. Add. */
if (sdp_audio_codec_by_payload_type(r, a->payload_type, false)) {
/* Oh crunch, that payload type number is already in use.
* Find an unused one. */
for (a->payload_type = 96; a->payload_type <= 127; a->payload_type++) {
if (!sdp_audio_codec_by_payload_type(r, a->payload_type, false))
break;
}
if (a->payload_type > 127)
return -ENOSPC;
}
select = sdp_audio_codec_add_copy(r, a);
}
sdp_audio_codecs_select(r, select);
}
#else
/* Currently, osmo-msc does not trigger re-assignment if the remote side has picked a codec that the local side
* would also support, but the local side has already assigned a mismatching codec before. Mismatching codecs
* means call failure. So, currently, if locally, Assignment has already happened, it makes sense to send only
* the assigned codec as available choice to the remote side. */
if (a->subtype_name[0]) {
/* Assignment has completed, the chosen codec should be the the only possible one. */
struct sdp_audio_codecs assigned_codec = {};
sdp_audio_codec_add_copy(&assigned_codec, a);
sdp_audio_codecs_intersection(r, &assigned_codec, false);
}
#endif
return 0;
}
int cc_sdp_name_buf(char *buf, size_t buflen, const struct cc_sdp *cc_sdp)
{
struct osmo_strbuf sb = { .buf = buf, .len = buflen };
OSMO_STRBUF_PRINTF(sb, "RAN={");
OSMO_STRBUF_APPEND(sb, sdp_audio_codecs_name_buf, &cc_sdp->ran);
OSMO_STRBUF_PRINTF(sb, "}");
if (cc_sdp->cell.count) {
OSMO_STRBUF_PRINTF(sb, " cell={");
OSMO_STRBUF_APPEND(sb, sdp_audio_codecs_name_buf, &cc_sdp->cell);
OSMO_STRBUF_PRINTF(sb, "}");
}
if (cc_sdp->ms.count) {
OSMO_STRBUF_PRINTF(sb, " MS={");
OSMO_STRBUF_APPEND(sb, sdp_audio_codecs_name_buf, &cc_sdp->ms);
OSMO_STRBUF_PRINTF(sb, "}");
}
if (cc_sdp->remote.audio_codecs.count
|| osmo_sockaddr_str_is_nonzero(&cc_sdp->remote.rtp)) {
OSMO_STRBUF_PRINTF(sb, " remote=");
OSMO_STRBUF_APPEND(sb, sdp_msg_name_buf, &cc_sdp->remote);
}
if (cc_sdp->assignment.subtype_name[0]) {
OSMO_STRBUF_PRINTF(sb, " assigned=");
OSMO_STRBUF_APPEND(sb, sdp_audio_codec_name_buf, &cc_sdp->assignment);
}
OSMO_STRBUF_PRINTF(sb, " result=");
OSMO_STRBUF_APPEND(sb, sdp_msg_name_buf, &cc_sdp->result);
return sb.chars_needed;
}
char *cc_sdp_name_c(void *ctx, const struct cc_sdp *cc_sdp)
{
OSMO_NAME_C_IMPL(ctx, 128, "cc_sdp_name_c-ERROR", cc_sdp_name_buf, cc_sdp)
}
const char *cc_sdp_name(const struct cc_sdp *cc_sdp)
{
return cc_sdp_name_c(OTC_SELECT, cc_sdp);
}
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