| /* |
| * (C) 2009-2015 by Holger Hans Peter Freyther <zecke@selfish.org> |
| * (C) 2009-2014 by On-Waves |
| * 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 <http://www.gnu.org/licenses/>. |
| * |
| */ |
| #include <osmocom/mgcp/mgcp.h> |
| #include <osmocom/mgcp/osmux.h> |
| #include <osmocom/mgcp/mgcp_conn.h> |
| #include <osmocom/mgcp/mgcp_protocol.h> |
| #include <osmocom/mgcp/mgcp_endp.h> |
| #include <osmocom/mgcp/mgcp_trunk.h> |
| #include <osmocom/mgcp/mgcp_codec.h> |
| #include <errno.h> |
| |
| /* Helper function to dump codec information of a specified codec to a printable |
| * string, used by dump_codec_summary() */ |
| static char *dump_codec(struct mgcp_rtp_codec *codec) |
| { |
| static char str[256]; |
| char *pt_str; |
| |
| if (codec->payload_type > 76) |
| pt_str = "DYNAMIC"; |
| else if (codec->payload_type > 72) |
| pt_str = "RESERVED <!>"; |
| else if (codec->payload_type != PTYPE_UNDEFINED) |
| pt_str = codec->subtype_name; |
| else |
| pt_str = "INVALID <!>"; |
| |
| snprintf(str, sizeof(str), "(pt:%i=%s, audio:%s subt=%s, rate=%u, ch=%i, t=%u/%u)", codec->payload_type, pt_str, |
| codec->audio_name, codec->subtype_name, codec->rate, codec->channels, codec->frame_duration_num, |
| codec->frame_duration_den); |
| return str; |
| } |
| |
| /*! Dump a summary of all negotiated codecs to debug log |
| * \param[in] conn related rtp-connection. */ |
| void mgcp_codec_summary(struct mgcp_conn_rtp *conn) |
| { |
| struct mgcp_rtp_end *rtp; |
| unsigned int i; |
| struct mgcp_rtp_codec *codec; |
| struct mgcp_endpoint *endp; |
| |
| rtp = &conn->end; |
| endp = conn->conn->endp; |
| |
| if (rtp->codecs_assigned == 0) { |
| LOGPENDP(endp, DLMGCP, LOGL_ERROR, "conn:%s no codecs available\n", |
| mgcp_conn_dump(conn->conn)); |
| return; |
| } |
| |
| /* Store parsed codec information */ |
| for (i = 0; i < rtp->codecs_assigned; i++) { |
| codec = &rtp->codecs[i]; |
| |
| LOGPENDP(endp, DLMGCP, LOGL_DEBUG, "conn:%s codecs[%u]:%s", |
| mgcp_conn_dump(conn->conn), i, dump_codec(codec)); |
| |
| if (codec == rtp->codec) |
| LOGPC(DLMGCP, LOGL_DEBUG, " [selected]"); |
| |
| LOGPC(DLMGCP, LOGL_DEBUG, "\n"); |
| } |
| } |
| |
| /* Initalize or reset codec information with default data. */ |
| static void codec_init(struct mgcp_rtp_codec *codec) |
| { |
| *codec = (struct mgcp_rtp_codec){ |
| .payload_type = -1, |
| .frame_duration_num = DEFAULT_RTP_AUDIO_FRAME_DUR_NUM, |
| .frame_duration_den = DEFAULT_RTP_AUDIO_FRAME_DUR_DEN, |
| .rate = DEFAULT_RTP_AUDIO_DEFAULT_RATE, |
| .channels = DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS, |
| .subtype_name = "", |
| .audio_name = "", |
| }; |
| } |
| |
| static void codec_free(struct mgcp_rtp_codec *codec) |
| { |
| *codec = (struct mgcp_rtp_codec){}; |
| } |
| |
| /*! Initalize or reset codec information with default data. |
| * \param[out] conn related rtp-connection. */ |
| void mgcp_codec_reset_all(struct mgcp_conn_rtp *conn) |
| { |
| int i; |
| for (i = 0; i < conn->end.codecs_assigned; i++) |
| codec_free(&conn->end.codecs[i]); |
| conn->end.codecs_assigned = 0; |
| conn->end.codec = NULL; |
| } |
| |
| /*! Add codec configuration depending on payload type and/or codec name. This |
| * function uses the input parameters to extrapolate the full codec information. |
| * \param[out] codec configuration (caller provided memory). |
| * \param[out] conn related rtp-connection. |
| * \param[in] payload_type codec type id (e.g. 3 for GSM, -1 when undefined). |
| * \param[in] audio_name audio codec name, in uppercase (e.g. "GSM/8000/1"). |
| * \param[in] param optional codec parameters (set to NULL when unused). |
| * \returns 0 on success, -EINVAL on failure. */ |
| int mgcp_codec_add(struct mgcp_conn_rtp *conn, int payload_type, const char *audio_name, const struct mgcp_codec_param *param) |
| { |
| int rate; |
| int channels; |
| struct mgcp_rtp_codec *codec; |
| unsigned int pt_offset = conn->end.codecs_assigned; |
| |
| /* The amount of codecs we can store is limited, make sure we do not |
| * overrun this limit. */ |
| if (conn->end.codecs_assigned >= MGCP_MAX_CODECS) |
| return -EINVAL; |
| |
| /* First unused entry */ |
| codec = &conn->end.codecs[conn->end.codecs_assigned]; |
| |
| /* Initalize the codec struct with some default data to begin with */ |
| codec_init(codec); |
| |
| if (payload_type != PTYPE_UNDEFINED) { |
| /* Make sure we do not get any reserved or undefined type numbers */ |
| /* See also: https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml */ |
| if ((payload_type == 1 || payload_type == 2 || payload_type == 19) |
| || (payload_type >= 72 && payload_type <= 76) |
| || (payload_type >= 127)) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot add codec, payload type number %d is reserved\n", |
| payload_type); |
| goto error; |
| } |
| |
| codec->payload_type = payload_type; |
| } |
| |
| /* When no audio name is given, we are forced to use the payload |
| * type to generate the audio name. This is only possible for |
| * non dynamic payload types, which are statically defined */ |
| if (!audio_name) { |
| switch (payload_type) { |
| case 0: |
| strcpy(codec->audio_name, "PCMU/8000/1"); |
| break; |
| case 3: |
| strcpy(codec->audio_name, "GSM/8000/1"); |
| break; |
| case 8: |
| strcpy(codec->audio_name, "PCMA/8000/1"); |
| break; |
| case 18: |
| strcpy(codec->audio_name, "G729/8000/1"); |
| break; |
| default: |
| /* The given payload type is not known to us, or it |
| * it is a dynamic payload type for which we do not |
| * know the audio name. We must give up here */ |
| LOGP(DLMGCP, LOGL_ERROR, "No audio codec name given, and payload type %d unknown\n", |
| payload_type); |
| goto error; |
| } |
| } else { |
| OSMO_STRLCPY_ARRAY(codec->audio_name, audio_name); |
| } |
| |
| /* Now we extract the codec subtype name, rate and channels. The latter |
| * two are optional. If they are not present we use the safe defaults |
| * above. */ |
| if (strlen(codec->audio_name) >= sizeof(codec->subtype_name)) { |
| LOGP(DLMGCP, LOGL_ERROR, "Audio codec too long: %s\n", osmo_quote_str(codec->audio_name, -1)); |
| goto error; |
| } |
| channels = DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS; |
| rate = DEFAULT_RTP_AUDIO_DEFAULT_RATE; |
| if (sscanf(codec->audio_name, "%63[^/]/%d/%d", codec->subtype_name, &rate, &channels) < 1) { |
| LOGP(DLMGCP, LOGL_ERROR, "Invalid audio codec: %s\n", osmo_quote_str(codec->audio_name, -1)); |
| goto error; |
| } |
| |
| /* Note: We only accept configurations with one audio channel! */ |
| if (channels != 1) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot handle audio codec with more than one channel: %s\n", |
| osmo_quote_str(codec->audio_name, -1)); |
| goto error; |
| } |
| |
| codec->rate = rate; |
| codec->channels = channels; |
| codec->payload_type = payload_type; |
| |
| if (!strcmp(codec->subtype_name, "G729")) { |
| codec->frame_duration_num = 10; |
| codec->frame_duration_den = 1000; |
| } else { |
| codec->frame_duration_num = DEFAULT_RTP_AUDIO_FRAME_DUR_NUM; |
| codec->frame_duration_den = DEFAULT_RTP_AUDIO_FRAME_DUR_DEN; |
| } |
| |
| /* Derive the payload type if it is unknown */ |
| if (codec->payload_type == PTYPE_UNDEFINED) { |
| /* TODO: This is semi dead code, see OS#4150 */ |
| |
| /* For the known codecs from the static range we restore |
| * the IANA or 3GPP assigned payload type number */ |
| if (codec->rate == 8000 && codec->channels == 1) { |
| /* See also: https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml */ |
| if (!strcmp(codec->subtype_name, "GSM")) |
| codec->payload_type = 3; |
| else if (!strcmp(codec->subtype_name, "PCMA")) |
| codec->payload_type = 8; |
| else if (!strcmp(codec->subtype_name, "PCMU")) |
| codec->payload_type = 0; |
| else if (!strcmp(codec->subtype_name, "G729")) |
| codec->payload_type = 18; |
| |
| /* See also: 3GPP TS 48.103, chapter 5.4.2.2 RTP Payload |
| * Note: These are not fixed payload types as the IANA |
| * defined once, they still remain dymanic payload |
| * types, but with a payload type number preference. */ |
| else if (!strcmp(codec->subtype_name, "GSM-EFR")) |
| codec->payload_type = 110; |
| else if (!strcmp(codec->subtype_name, "GSM-HR-08")) |
| codec->payload_type = 111; |
| else if (!strcmp(codec->subtype_name, "AMR")) |
| codec->payload_type = 112; |
| else if (!strcmp(codec->subtype_name, "AMR-WB")) |
| codec->payload_type = 113; |
| } |
| |
| /* If we could not determine a payload type we assume that |
| * we are dealing with a codec from the dynamic range. We |
| * choose a fixed identifier from 96-109. (Note: normally, |
| * the dynamic payload type rante is from 96-127, but from |
| * 110 onwards 3gpp defines prefered codec types, which are |
| * also fixed, see above) */ |
| if (codec->payload_type < 0) { |
| /* FIXME: pt_offset is completely unrelated and useless here, any of those numbers may already |
| * have been added to the codecs. Instead, there should be an iterator checking for an actually |
| * unused dynamic payload type number. */ |
| codec->payload_type = 96 + pt_offset; |
| if (codec->payload_type > 109) { |
| LOGP(DLMGCP, LOGL_ERROR, "Ran out of payload type numbers to assign dynamically\n"); |
| goto error; |
| } |
| } |
| } |
| |
| /* Copy over optional codec parameters */ |
| if (param) { |
| codec->param = *param; |
| codec->param_present = true; |
| } else |
| codec->param_present = false; |
| |
| conn->end.codecs_assigned++; |
| return 0; |
| error: |
| /* Make sure we leave a clean codec entry on error. */ |
| codec_free(codec); |
| return -EINVAL; |
| } |
| |
| /* Check if the given codec is applicable on the specified endpoint |
| * Helper function for mgcp_codec_decide() */ |
| static bool is_codec_compatible(const struct mgcp_endpoint *endp, const struct mgcp_rtp_codec *codec) |
| { |
| /* A codec name must be set, if not, this might mean that the codec |
| * (payload type) that was assigned is unknown to us so we must stop |
| * here. */ |
| if (!strlen(codec->subtype_name)) |
| return false; |
| |
| /* FIXME: implement meaningful checks to make sure that the given codec |
| * is compatible with the given endpoint */ |
| |
| return true; |
| } |
| |
| /*! Decide for one suitable codec |
| * \param[in] conn related rtp-connection. |
| * \returns 0 on success, -EINVAL on failure. */ |
| int mgcp_codec_decide(struct mgcp_conn_rtp *conn) |
| { |
| struct mgcp_rtp_end *rtp; |
| unsigned int i; |
| struct mgcp_endpoint *endp; |
| bool codec_assigned = false; |
| |
| endp = conn->conn->endp; |
| rtp = &conn->end; |
| |
| /* This function works on the results the SDP/LCO parser has extracted |
| * from the MGCP message. The goal is to select a suitable codec for |
| * the given connection. When transcoding is available, the first codec |
| * from the codec list is taken without further checking. When |
| * transcoding is not available, then the choice must be made more |
| * carefully. Each codec in the list is checked until one is found that |
| * is rated compatible. The rating is done by the helper function |
| * is_codec_compatible(), which does the actual checking. */ |
| for (i = 0; i < rtp->codecs_assigned; i++) { |
| /* When no transcoding is available, avoid codecs that would |
| * require transcoding. */ |
| if (endp->trunk->no_audio_transcoding && !is_codec_compatible(endp, &rtp->codecs[i])) { |
| LOGP(DLMGCP, LOGL_NOTICE, "transcoding not available, skipping codec: %d/%s\n", |
| rtp->codecs[i].payload_type, rtp->codecs[i].subtype_name); |
| continue; |
| } |
| |
| rtp->codec = &rtp->codecs[i]; |
| codec_assigned = true; |
| break; |
| } |
| |
| /* FIXME: To the reviewes: This is problematic. I do not get why we |
| * need to reset the packet_duration_ms depending on the codec |
| * selection. I thought it were all 20ms? Is this to address some |
| * cornercase. (This piece of code was in the code path before, |
| * together with the note: "TODO/XXX: Store this per codec and derive |
| * it on use" */ |
| if (codec_assigned) { |
| if (rtp->maximum_packet_time >= 0 |
| && rtp->maximum_packet_time * rtp->codec->frame_duration_den > |
| rtp->codec->frame_duration_num * 1500) |
| rtp->packet_duration_ms = 0; |
| |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /* Return true if octet-aligned is set in the given codec. Default to octet-aligned=0, i.e. bandwidth-efficient mode. |
| * See RFC4867 "RTP Payload Format for AMR and AMR-WB" sections "8.1. AMR Media Type Registration" and "8.2. AMR-WB |
| * Media Type Registration": |
| * |
| * octet-align: Permissible values are 0 and 1. If 1, octet-aligned |
| * operation SHALL be used. If 0 or if not present, |
| * bandwidth-efficient operation is employed. |
| * |
| * https://tools.ietf.org/html/rfc4867 |
| */ |
| bool mgcp_codec_amr_is_octet_aligned(const struct mgcp_rtp_codec *codec) |
| { |
| if (!codec->param_present) |
| return false; |
| if (!codec->param.amr_octet_aligned_present) |
| return false; |
| return codec->param.amr_octet_aligned; |
| } |
| |
| /* Compare two codecs, all parameters must match up, except for the payload type |
| * number. */ |
| static bool codecs_same(struct mgcp_rtp_codec *codec_a, struct mgcp_rtp_codec *codec_b) |
| { |
| if (codec_a->rate != codec_b->rate) |
| return false; |
| if (codec_a->channels != codec_b->channels) |
| return false; |
| if (codec_a->frame_duration_num != codec_b->frame_duration_num) |
| return false; |
| if (codec_a->frame_duration_den != codec_b->frame_duration_den) |
| return false; |
| if (strcmp(codec_a->subtype_name, codec_b->subtype_name)) |
| return false; |
| |
| /* Note: AMR allows to set the RTP payload format to octet-aligned or bandwith-efficient (octet-aligned=0) |
| * via SDP. This difference concerns payload format only, but not the actual codec. It is not a difference |
| * within the meaning of this function. */ |
| |
| return true; |
| } |
| |
| /*! Translate a given payload type number that belongs to the packet of a |
| * source connection to the equivalent payload type number that matches the |
| * configuration of a destination connection. |
| * \param[in] conn_src related source rtp-connection. |
| * \param[in] conn_dst related destination rtp-connection. |
| * \param[in] payload_type number from the source packet or source connection. |
| * \returns translated payload type number on success, -EINVAL on failure. */ |
| int mgcp_codec_pt_translate(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst, int payload_type) |
| { |
| struct mgcp_rtp_end *rtp_src; |
| struct mgcp_rtp_end *rtp_dst; |
| struct mgcp_rtp_codec *codec_src = NULL; |
| struct mgcp_rtp_codec *codec_dst = NULL; |
| unsigned int i; |
| unsigned int codecs_assigned; |
| |
| rtp_src = &conn_src->end; |
| rtp_dst = &conn_dst->end; |
| |
| /* Find the codec information that is used on the source side */ |
| codecs_assigned = rtp_src->codecs_assigned; |
| OSMO_ASSERT(codecs_assigned <= MGCP_MAX_CODECS); |
| for (i = 0; i < codecs_assigned; i++) { |
| if (payload_type == rtp_src->codecs[i].payload_type) { |
| codec_src = &rtp_src->codecs[i]; |
| break; |
| } |
| } |
| if (!codec_src) |
| return -EINVAL; |
| |
| /* Use the codec information from the source and try to find the |
| * equivalent of it on the destination side */ |
| codecs_assigned = rtp_dst->codecs_assigned; |
| OSMO_ASSERT(codecs_assigned <= MGCP_MAX_CODECS); |
| for (i = 0; i < codecs_assigned; i++) { |
| if (codecs_same(codec_src, &rtp_dst->codecs[i])) { |
| codec_dst = &rtp_dst->codecs[i]; |
| break; |
| } |
| } |
| if (!codec_dst) |
| return -EINVAL; |
| |
| return codec_dst->payload_type; |
| } |
| |
| /* Find the payload type number configured for a specific codec by SDP. |
| * For example, IuUP gets assigned a payload type number, and the endpoint needs to translate that to the number |
| * assigned to "AMR" on the other conn (by a=rtpmap:N). |
| * \param conn The side of an endpoint to get the payload type number for (to translate the payload type number to). |
| * \param subtype_name SDP codec name without parameters (e.g. "AMR"). |
| * \param match_nr Index for the match found, first being match_nr == 0. Iterate all matches by calling multiple times |
| * with incrementing match_nr. |
| * \return codec definition for that conn matching the subtype_name, or NULL if no such match_nr is found. |
| */ |
| const struct mgcp_rtp_codec *mgcp_codec_pt_find_by_subtype_name(struct mgcp_conn_rtp *conn, |
| const char *subtype_name, unsigned int match_nr) |
| { |
| int i; |
| for (i = 0; i < conn->end.codecs_assigned; i++) { |
| if (!strcmp(conn->end.codecs[i].subtype_name, subtype_name)) { |
| if (match_nr) { |
| match_nr--; |
| continue; |
| } |
| return &conn->end.codecs[i]; |
| } |
| } |
| return NULL; |
| } |