gsm0808: Add utils for Speech Codec List and Speech Codec

The planned support for true A over IP requires the encoding and
decoding of a so called "Speech Codec Element" element.

This commt adds parsing functionality and tests for the element
mentioned above, however, it is not yet actively used.

Change-Id: I0e1e2edf47adaa45b22d4b0bcae3640dba7ca200

2 files changed, 41 insertions, 0 deletions

diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index 5fc1c880..b5ddbdb7 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -21,6 +21,8 @@
 
 #include <sys/socket.h>
 
+#include <osmocom/gsm/protocol/gsm_08_08.h>
+
 /* Encode AoIP transport address element */
 uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg,
 				    const struct sockaddr_storage *ss);
@@ -28,3 +30,20 @@ uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg,
 /* Decode AoIP transport address element */
 int gsm0808_dec_aoip_trasp_addr(struct sockaddr_storage *ss,
 				const uint8_t *elem, uint8_t len);
+
+/* Encode Speech Codec element */
+uint8_t gsm0808_enc_speech_codec(struct msgb *msg,
+				 const struct gsm0808_speech_codec *sc);
+
+/* Decode Speech Codec element */
+int gsm0808_dec_speech_codec(struct gsm0808_speech_codec *sc,
+			     const uint8_t *elem, uint8_t len);
+
+/* Encode Speech Codec list */
+uint8_t gsm0808_enc_speech_codec_list(struct msgb *msg,
+				      const struct gsm0808_speech_codec_list
+				      *scl);
+
+/* Decode Speech Codec list */
+int gsm0808_dec_speech_codec_list(struct gsm0808_speech_codec_list *scl,
+				  const uint8_t *elem, uint8_t len);
diff --git a/include/osmocom/gsm/protocol/gsm_08_08.h b/include/osmocom/gsm/protocol/gsm_08_08.h
index 6fb4e9e8..3e5514dc 100644
--- a/include/osmocom/gsm/protocol/gsm_08_08.h
+++ b/include/osmocom/gsm/protocol/gsm_08_08.h
@@ -3,6 +3,9 @@
 #pragma once
 
 #include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <osmocom/core/linuxlist.h>
 
 /*
  * this is from GSM 03.03 CGI but is copied in GSM 08.08
@@ -416,3 +419,22 @@ enum gsm0808_paging_info {
 	GSM0808_PAGINF_FOR_SMS		= 0x01,
 	GSM0808_PAGINF_FOR_USSD		= 0x02,
 };
+
+/* 3GPP TS 48.008 3.2.2.104 Speech Codec */
+struct gsm0808_speech_codec {
+	bool fi;
+	bool pi;
+	bool pt;
+	bool tf;
+	uint8_t type;
+	uint16_t cfg;
+	bool type_extended;
+	bool cfg_present;
+};
+
+/* 3GPP TS 48.008 3.2.2.103 Speech Codec List */
+#define SPEECH_CODEC_MAXLEN 255
+struct gsm0808_speech_codec_list {
+	struct gsm0808_speech_codec codec[SPEECH_CODEC_MAXLEN];
+	uint8_t len;
+};