sm: Introduce APIs to enc/dec QoS Profile

Ported from  open5gs.git/lib/gtp/v1/types.{c,h} 5764f7267d16a8ea6aeedc6c227552575915def5,
for which I was the author too.
The ARP extra byte field at the start of the IE val which is introduced in the
GTP variant is dropped when porting to SM, since it's not present there
(and offsets/sizes are adjusted).

The QoS code is moved is moved into a common/ directory where a new
libosmo-gprs-common.la private static library is created.
This is done in order to be able to resuse the QoS dec/enc code in
several libraries since it's actually planned to use it in SNDCP and SM
layers.
The most natural place to add the APIs is SM, and that's where the
public API to accees the enc/dec is provided, since the user app will
have to use them in the SM SAP.
However, the SNDCP will also have to decode the QoS recived by SM
through the SNSM SAP, and we don't really want libosmo-gprs-sndcp depend
on libosmo-gprs-sm. This way libosmo-gprs-sndcp will be able to use the
private APIs directly in a follow-up commit.

Change-Id: I6c0676e55bb1f0f424f41d8d04d4f5e5bf376f4f

10 files changed, 475 insertions, 4 deletions

diff --git a/configure.ac b/configure.ac
index 52b9d14..91fb36a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -90,6 +90,7 @@ AC_CONFIG_FILES([libosmo-csn1.pc
 		 include/osmocom/gprs/sndcp/Makefile
 		 include/osmocom/gprs/sm/Makefile
 		 src/Makefile
+		 src/common/Makefile
 		 src/csn1/Makefile
 		 src/gmm/Makefile
 		 src/llc/Makefile
diff --git a/include/osmocom/gprs/sm/Makefile.am b/include/osmocom/gprs/sm/Makefile.am
index 46a30cb..f6bede4 100644
--- a/include/osmocom/gprs/sm/Makefile.am
+++ b/include/osmocom/gprs/sm/Makefile.am
@@ -8,6 +8,7 @@ noinst_HEADERS = \
 sm_HEADERS = \
 	sm.h \
 	sm_prim.h \
+	sm_qos.h \
 	$(NULL)
 
 smdir = $(includedir)/osmocom/gprs/sm
diff --git a/include/osmocom/gprs/sm/sm.h b/include/osmocom/gprs/sm/sm.h
index 37f86bc..089faa1 100644
--- a/include/osmocom/gprs/sm/sm.h
+++ b/include/osmocom/gprs/sm/sm.h
@@ -5,6 +5,8 @@
 #include <stdint.h>
 #include <stddef.h>
 
+#include <osmocom/gprs/sm/sm_qos.h>
+
 /* 3GPP TS 24.008 10.5.6.1 */
 #define OSMO_GPRS_SM_APN_MAXLEN	100
 
@@ -14,9 +16,6 @@
 /* 3GPP TS 24.008 10.5.6.3 Protocol configuration options */
 #define OSMO_GPRS_SM_PCO_MAXLEN 253
 
-/* 3GPP TS 24.008 10.5.6.5 Quality of service */
-#define OSMO_GPRS_SM_QOS_MAXLEN 22
-
 /* 3GPP TS 24.008 10.5.6.21 NBIFOM container (T=1,L=1,V=255 => 257) */
 #define OSMO_GPRS_SM_MBIFORM_MAXLEN 255
 
diff --git a/include/osmocom/gprs/sm/sm_qos.h b/include/osmocom/gprs/sm/sm_qos.h
new file mode 100644
index 0000000..a1ffe63
--- /dev/null
+++ b/include/osmocom/gprs/sm/sm_qos.h
@@ -0,0 +1,96 @@
+/* GPRS QoS definitions from 3GPP TS 24.008 sec 10.5.6.5 */
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <osmocom/core/endian.h>
+
+/* 3GPP TS 24.008 10.5.6.5 Quality of service */
+#define OSMO_GPRS_SM_QOS_MAXLEN 22
+
+/* TS 24.008 10.5.6.5 Quality of service */
+struct osmo_gprs_sm_qos_profile_data_extended_bit_rate {
+	uint8_t max_bit_rate_uplink;
+	uint8_t guaranteed_bit_rate_uplink;
+	uint8_t max_bit_rate_downlink;
+	uint8_t guaranteed_bit_rate_downlink;
+} __attribute__ ((packed));
+
+struct osmo_gprs_sm_qos_profile_data {
+#if OSMO_IS_LITTLE_ENDIAN
+	uint8_t reliability_class:3,
+		delay_class:2,
+		spare1:3;
+	uint8_t precedence_class:3,
+		spare2:1,
+		peak_throughput:4;
+	uint8_t mean_throughput:5,
+		spare3:3;
+	uint8_t delivery_erroneous_sdu:3,
+		delivery_order:2,
+		traffic_class:3;
+	uint8_t max_sdu_size;
+	uint8_t max_bit_rate_uplink;
+	uint8_t max_bit_rate_downlink;
+	uint8_t sdu_error_ratio:4,
+		residual_ber:4;
+	uint8_t traffic_handling_priority:2,
+		transfer_delay:6;
+	uint8_t guaranteed_bit_rate_uplink;
+	uint8_t guaranteed_bit_rate_downlink;
+	uint8_t source_statistics_descriptor:4,
+		signalling_indication:1,
+		spare4:3;
+	struct osmo_gprs_sm_qos_profile_data_extended_bit_rate extended;
+	struct osmo_gprs_sm_qos_profile_data_extended_bit_rate extended2;
+#elif OSMO_IS_BIG_ENDIAN
+/* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */
+	uint8_t spare1:3, delay_class:2, reliability_class:3;
+	uint8_t peak_throughput:4, spare2:1, precedence_class:3;
+	uint8_t spare3:3, mean_throughput:5;
+	uint8_t traffic_class:3, delivery_order:2, delivery_erroneous_sdu:3;
+	uint8_t max_sdu_size;
+	uint8_t max_bit_rate_uplink;
+	uint8_t max_bit_rate_downlink;
+	uint8_t residual_ber:4, sdu_error_ratio:4;
+	uint8_t transfer_delay:6, traffic_handling_priority:2;
+	uint8_t guaranteed_bit_rate_uplink;
+	uint8_t guaranteed_bit_rate_downlink;
+	uint8_t spare4:3, signalling_indication:1, source_statistics_descriptor:4;
+	struct osmo_gprs_sm_qos_profile_data_extended_bit_rate extended;
+	struct osmo_gprs_sm_qos_profile_data_extended_bit_rate extended2;
+#endif
+} __attribute__ ((packed));
+
+struct osmo_gprs_sm_qos_profile {
+	struct osmo_gprs_sm_qos_profile_data data;
+} __attribute__ ((packed));
+struct osmo_gprs_sm_qos_profile_decoded {
+	struct osmo_gprs_sm_qos_profile qos_profile;
+	/* Filled in by the decoder function: */
+	bool data_octet6_to_13_present; /* from traffic_class to guaranteed_bit_rate_downlink */
+	bool data_octet14_present; /* byte containing signalling_indication */
+	bool bit_rate_downlink_extended_present;
+	bool bit_rate_uplink_extended_present;
+	bool bit_rate_downlink_extended2_present;
+	bool bit_rate_uplink_extended2_present;
+	uint16_t dec_transfer_delay;
+	uint32_t dec_mbr_kbps_dl; /* decoded MBR in kbps */
+	uint32_t dec_mbr_kbps_ul; /* decoded MBR in kbps */
+	uint32_t dec_gbr_kbps_dl; /* decoded GBR in kbps */
+	uint32_t dec_gbr_kbps_ul; /* decoded GBR in kbps */
+} __attribute__ ((packed));
+
+#define OSMO_GPRS_SM_QOS_TRAFFIC_CLASS_SUBSCRIBED 0
+#define OSMO_GPRS_SM_QOS_TRAFFIC_CLASS_CONVERSATIONAL 1
+#define OSMO_GPRS_SM_QOS_TRAFFIC_CLASS_STREAMING 2
+#define OSMO_GPRS_SM_QOS_TRAFFIC_CLASS_INTERACTIVE 3
+#define OSMO_GPRS_SM_QOS_TRAFFIC_CLASS_BACKGROUND 4
+
+#define OSMO_GPRS_SM_QOS_SRC_STATS_DESC_UNKNOWN 0
+#define OSMO_GPRS_SM_QOS_SRC_STATS_DESC_SPEECH 1
+
+int16_t osmo_gprs_sm_qos_parse_qos_profile(
+	struct osmo_gprs_sm_qos_profile_decoded *decoded, const uint8_t *data, size_t data_len);
+int16_t osmo_gprs_sm_qos_build_qos_profile(const struct osmo_gprs_sm_qos_profile_decoded *decoded, void *data, int data_len);
diff --git a/src/Makefile.am b/src/Makefile.am
index 69ce5a0..90d901f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,4 +1,5 @@
 SUBDIRS = \
+	common \
 	csn1 \
 	llc \
 	rlcmac \
diff --git a/src/common/Makefile.am b/src/common/Makefile.am
new file mode 100644
index 0000000..ae7c2bd
--- /dev/null
+++ b/src/common/Makefile.am
@@ -0,0 +1,22 @@
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	$(NULL)
+
+AM_CFLAGS = \
+	-Wall \
+	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(NULL)
+
+noinst_LTLIBRARIES = \
+	libosmo-gprs-common.la \
+	$(NULL)
+
+libosmo_gprs_common_la_SOURCES = \
+	qos.c \
+	$(NULL)
+
+noinst_HEADERS = \
+	qos.h \
+	$(NULL)
diff --git a/src/common/qos.c b/src/common/qos.c
new file mode 100644
index 0000000..3de532f
--- /dev/null
+++ b/src/common/qos.c
@@ -0,0 +1,303 @@
+/* GPRS QoS definitions from 3GPP TS 24.008 sec 10.5.6.5 */
+/*
+ * (C) 2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * 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/core/utils.h>
+#include <osmocom/core/logging.h>
+#include "qos.h"
+
+#define GPRS_QOS_FALLTHROUGH __attribute__ ((fallthrough))
+
+static uint32_t dec_mbr_kbps(uint8_t mbr_byte, const uint8_t *extended_mbr_byte, const uint8_t *extended2_mbr_byte)
+{
+	uint8_t mbr, embr1, embr2;
+	mbr = mbr_byte;
+	embr1 = extended_mbr_byte ? *extended_mbr_byte : 0;
+	embr2 = extended2_mbr_byte ? *extended2_mbr_byte : 0;
+
+	if (mbr == 0)
+		return 0;
+	if (mbr == 0xff)
+		return UINT32_MAX;
+	if (mbr == 0xfe) { /* Check extended field */
+		if (extended_mbr_byte == NULL || embr1 == 0)
+			return 8640;
+		if (embr1 == 0xfa) { /* Check extended2 field */
+			if (extended2_mbr_byte == NULL || embr2 == 0)
+				return 256 * 1000;
+			if (embr2 == 0xf6)
+				return 10 * 1000 * 1000; /* TODO: check "extended quality of service" IE */
+			if (embr2 >= 0xa2 && embr2 <= 0xf6)
+				return (1500 + (embr2 - (0xa2 - 1)) * 100) * 1000;
+			if (embr2 >= 0x3e && embr2 <= 0xa1)
+				return (500 + (embr2 - (0x3e - 1)) * 10) * 1000;
+			return (256 + embr2 * 4) * 1000;
+		}
+		if (embr1 >= 0xbb && embr1 <= 0xfa)
+			return (128 + (embr1 - (0xbb - 1)) * 2) * 1000;
+		if (embr1 >= 0x4b && embr1 <= 0xba)
+			return (16 + (embr1 - (0x4b - 1)) * 1) * 1000;
+		return 8600 + embr1 * 100;
+	}
+	if (mbr & 0x80) {
+		mbr &= ~0x80;
+		return 576 + mbr_byte * 64;
+	}
+	if (mbr & 0x40) {
+		mbr &= ~0x40;
+		return 64 + mbr * 8;
+	}
+	return mbr;
+}
+
+static uint16_t dec_transfer_delay_ms(uint8_t transfer_delay_byte)
+{
+	transfer_delay_byte &= 0x3f; /* 6 bits */
+	if (transfer_delay_byte <= 0x0f)
+		return transfer_delay_byte;
+	if (transfer_delay_byte <= 0x1f)
+		return 200 + (transfer_delay_byte - 0x10) * 50;
+	return 1000 + (transfer_delay_byte - 0x20) * 100;
+}
+
+/* TS 29.060 7.7.34 Quality of Service (QoS) Profile */
+/* TS 24.008 10.5.6.5 Quality of service */
+int16_t gprs_qos_parse_qos_profile(
+	struct osmo_gprs_sm_qos_profile_decoded *decoded, const uint8_t *data, size_t data_len)
+{
+	struct osmo_gprs_sm_qos_profile *source = (struct osmo_gprs_sm_qos_profile *)data;
+
+	OSMO_ASSERT(decoded);
+	OSMO_ASSERT(data);
+
+	memset(decoded, 0, sizeof(struct osmo_gprs_sm_qos_profile_decoded));
+	switch (data_len) {
+	case 20: /* octet 3 + octet 3-22 */
+		decoded->bit_rate_uplink_extended2_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 18: /* octet 3 + octet 3-20 */
+		decoded->bit_rate_downlink_extended2_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 16: /* octet 3 + octet 3-18 */
+		decoded->bit_rate_uplink_extended_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 14: /* octet 3 + octet 3-16 */
+		decoded->bit_rate_downlink_extended_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 12: /* octet 3-14 */
+		decoded->data_octet14_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 11: /* octet 3-13 */
+		decoded->data_octet6_to_13_present = true;
+		GPRS_QOS_FALLTHROUGH;
+	case 3: /* octet 3 + octet 4 + octet 5 */
+		break;
+	default:
+		LOGP(DLGLOBAL, LOGL_ERROR, "Qos Profile wrong length %zu\n", data_len);
+		return -1;
+	}
+	memcpy(&decoded->qos_profile, source, data_len);
+
+	/* Calculate resulting MBRs in kbps: */
+	if (decoded->data_octet6_to_13_present) {
+		decoded->dec_transfer_delay = dec_transfer_delay_ms(source->data.transfer_delay);
+		decoded->dec_mbr_kbps_dl = dec_mbr_kbps(source->data.max_bit_rate_downlink,
+							decoded->bit_rate_downlink_extended_present ?
+								&source->data.extended.max_bit_rate_downlink : NULL,
+							decoded->bit_rate_downlink_extended2_present ?
+								&source->data.extended2.max_bit_rate_downlink : NULL);
+		decoded->dec_mbr_kbps_ul = dec_mbr_kbps(source->data.max_bit_rate_uplink,
+							decoded->bit_rate_uplink_extended_present ?
+								&source->data.extended.max_bit_rate_uplink : NULL,
+							decoded->bit_rate_uplink_extended2_present ?
+								&source->data.extended2.max_bit_rate_uplink : NULL);
+	  /* GBR is encoded the same way as MBR: */
+	  decoded->dec_gbr_kbps_dl = dec_mbr_kbps(source->data.guaranteed_bit_rate_downlink,
+						  decoded->bit_rate_downlink_extended_present ?
+							&source->data.extended.guaranteed_bit_rate_downlink : NULL,
+						  decoded->bit_rate_downlink_extended2_present ?
+							&source->data.extended2.guaranteed_bit_rate_downlink : NULL);
+	  decoded->dec_gbr_kbps_ul = dec_mbr_kbps(source->data.guaranteed_bit_rate_uplink,
+						  decoded->bit_rate_uplink_extended_present ?
+							&source->data.extended.guaranteed_bit_rate_uplink : NULL,
+						  decoded->bit_rate_uplink_extended2_present ?
+							&source->data.extended2.guaranteed_bit_rate_uplink : NULL);
+	}
+
+	return data_len;
+}
+
+static uint8_t enc_transfer_delay_ms(uint16_t transfer_delay_ms)
+{
+	if (transfer_delay_ms >= 4000)
+		return 0x3e;
+	if (transfer_delay_ms >= 1000) {
+		transfer_delay_ms -= 1000;
+		return 0x20 + (transfer_delay_ms / 100);
+	}
+	if (transfer_delay_ms >= 200) {
+		transfer_delay_ms -= 200;
+		return 0x10 + (transfer_delay_ms / 50);
+	}
+	if (transfer_delay_ms > 150)
+		transfer_delay_ms = 150;
+	if (transfer_delay_ms >= 10)
+		return transfer_delay_ms / 10;
+	return 1; /* 0 is "Reserved" Network->MS */
+}
+
+#define CHECK_EXT1 0xfe
+#define CHECK_EXT2 0xfa
+static uint32_t enc_mbr_kbps(uint32_t mbr_kbps, uint8_t *mbr_byte, uint8_t *extended_mbr_byte, uint8_t *extended2_mbr_byte)
+{
+	/* up to EXT2 byte: */
+	if (mbr_kbps > 10*1000*1000) {
+		*extended2_mbr_byte = 0xf6; /* TODO: need to set the real value somewhere else */
+		goto ret_check_ext2;
+	}
+	if (mbr_kbps >= 1600*1000) {
+		mbr_kbps -= 1500*1000;
+		*extended2_mbr_byte = 0xa1 + mbr_kbps/(100*1000);
+		goto ret_check_ext2;
+	}
+	if (mbr_kbps >= 510*1000) {
+		mbr_kbps -= 500*1000;
+		*extended2_mbr_byte = 0x2d + mbr_kbps/(10*1000);
+		goto ret_check_ext2;
+	}
+	if (mbr_kbps >= 260*1000) {
+		mbr_kbps -= 256*1000;
+		*extended2_mbr_byte = 0x00 + mbr_kbps/(4*1000);
+		goto ret_check_ext2;
+	}
+
+	/* up to EXT1 byte: */
+	if (mbr_kbps >= 130*1000) {
+		mbr_kbps -= 128*1000;
+		*extended_mbr_byte = 0xba +  mbr_kbps/(2*1000);
+		goto ret_check_ext1;
+	}
+	if (mbr_kbps >= 17*1000) {
+		mbr_kbps -= 16*1000;
+		*extended_mbr_byte = 0x4a +  mbr_kbps/(1*1000);
+		goto ret_check_ext1;
+	}
+	if (mbr_kbps >= 8700) {
+		mbr_kbps -= 8600;
+		*extended_mbr_byte = 0x00 +  mbr_kbps/(100);
+		goto ret_check_ext1;
+	}
+
+	/* Only MBR byte: */
+	if (mbr_kbps >= 576) {
+		mbr_kbps -= 576;
+		*mbr_byte = 0x80 +  mbr_kbps/(64);
+		goto ret_mbr;
+	}
+	if (mbr_kbps >= 64) {
+		mbr_kbps -= 64;
+		*mbr_byte = 0x40 + mbr_kbps/(8);
+		goto ret_mbr;
+	}
+	if (mbr_kbps > 0) {
+		*mbr_byte = mbr_kbps;
+		goto ret_mbr;
+	}
+	/* if (mbr_kpbs == 0) */
+	*mbr_byte = 0xff;
+	goto ret_mbr;
+
+ret_check_ext2:
+	*extended_mbr_byte = CHECK_EXT2;
+	*mbr_byte = CHECK_EXT1;
+	return 2;
+ret_check_ext1:
+	*extended2_mbr_byte = 0;
+	*mbr_byte = CHECK_EXT1;
+	return 1;
+ret_mbr:
+	*extended2_mbr_byte = 0;
+	*extended_mbr_byte = 0;
+	return 0;
+}
+
+int16_t gprs_qos_build_qos_profile(const struct osmo_gprs_sm_qos_profile_decoded *decoded, void *data, int data_len)
+{
+	struct osmo_gprs_sm_qos_profile *target;
+	int mbr_extended_dl, mbr_extended_ul;
+	int gbr_extended_dl, gbr_extended_ul;
+	int extended_dl, extended_ul;
+	unsigned int enc_len = 0;
+
+	OSMO_ASSERT(decoded);
+	OSMO_ASSERT(data);
+	OSMO_ASSERT((size_t)data_len >= sizeof(struct osmo_gprs_sm_qos_profile));
+
+	target = (struct osmo_gprs_sm_qos_profile *)data;
+
+	/* First, copy the encoded buffer as it is: */
+	memcpy(target, &decoded->qos_profile, sizeof(struct osmo_gprs_sm_qos_profile));
+
+	/* Avoid setting Traffic Handling to 0=Reserved even if ignored based on
+	 * Interactive/Background Traffic Class: */
+	if (target->data.traffic_handling_priority == 0)
+		target->data.traffic_handling_priority = 1;
+
+	/* Then, encode in the target position the decoded-provided fields: */
+	if (decoded->data_octet6_to_13_present)
+		target->data.transfer_delay = enc_transfer_delay_ms(decoded->dec_transfer_delay);
+
+	mbr_extended_dl = enc_mbr_kbps(decoded->dec_mbr_kbps_dl,
+				       &target->data.max_bit_rate_downlink,
+				       &target->data.extended.max_bit_rate_downlink,
+				       &target->data.extended2.max_bit_rate_downlink);
+	mbr_extended_ul = enc_mbr_kbps(decoded->dec_mbr_kbps_ul,
+				       &target->data.max_bit_rate_uplink,
+				       &target->data.extended.max_bit_rate_uplink,
+				       &target->data.extended2.max_bit_rate_uplink);
+	/* GBR is encoded the same way as MBR: */
+	gbr_extended_dl = enc_mbr_kbps(decoded->dec_gbr_kbps_dl,
+				       &target->data.guaranteed_bit_rate_downlink,
+				       &target->data.extended.guaranteed_bit_rate_downlink,
+				       &target->data.extended2.guaranteed_bit_rate_downlink);
+	gbr_extended_ul = enc_mbr_kbps(decoded->dec_gbr_kbps_ul,
+				       &target->data.guaranteed_bit_rate_uplink,
+				       &target->data.extended.guaranteed_bit_rate_uplink,
+				       &target->data.extended2.guaranteed_bit_rate_uplink);
+	extended_dl = OSMO_MAX(mbr_extended_dl, gbr_extended_dl);
+	extended_ul = OSMO_MAX(mbr_extended_ul, gbr_extended_ul);
+
+	/* Finally, set len based on the required octets to encode the fields: */
+	if (extended_ul == 2)
+		enc_len = 20;
+	else if (extended_dl == 2)
+		enc_len = 18;
+	else if (extended_ul == 1)
+		enc_len = 16;
+	else if (extended_dl == 1)
+		enc_len = 14;
+	else if (decoded->data_octet14_present)
+		enc_len = 12;
+	else if (decoded->data_octet6_to_13_present)
+		enc_len = 11;
+	else
+		enc_len = 5;
+	return enc_len;
+}
diff --git a/src/common/qos.h b/src/common/qos.h
new file mode 100644
index 0000000..3ddbacc
--- /dev/null
+++ b/src/common/qos.h
@@ -0,0 +1,12 @@
+/* GPRS QoS definitions from 3GPP TS 24.008 sec 10.5.6.5 */
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#include <osmocom/gprs/sm/sm_qos.h>
+
+int16_t gprs_qos_parse_qos_profile(
+	struct osmo_gprs_sm_qos_profile_decoded *decoded, const uint8_t *data, size_t data_len);
+int16_t gprs_qos_build_qos_profile(const struct osmo_gprs_sm_qos_profile_decoded *decoded, void *data, int data_len);
diff --git a/src/sm/Makefile.am b/src/sm/Makefile.am
index ecd8ba3..83b19de 100644
--- a/src/sm/Makefile.am
+++ b/src/sm/Makefile.am
@@ -23,6 +23,7 @@ libosmo_gprs_sm_la_SOURCES = \
 	sm_ms_fsm.c \
 	sm_pdu.c \
 	sm_prim.c \
+	sm_qos.c \
 	misc.c \
 	$(NULL)
 
@@ -35,7 +36,8 @@ libosmo_gprs_sm_la_LDFLAGS = \
 libosmo_gprs_sm_la_LIBADD = \
 	$(top_builddir)/src/gmm/libosmo-gprs-gmm.la \
 	$(top_builddir)/src/sndcp/libosmo-gprs-sndcp.la \
-	$(LIBOSMOCORE_LIBS) \
+	$(top_builddir)/src/common/libosmo-gprs-common.la \
 	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOCORE_LIBS) \
 	-lm \
 	$(NULL)
diff --git a/src/sm/sm_qos.c b/src/sm/sm_qos.c
new file mode 100644
index 0000000..504c2a2
--- /dev/null
+++ b/src/sm/sm_qos.c
@@ -0,0 +1,34 @@
+/* GPRS QoS definitions from 3GPP TS 24.008 sec 10.5.6.5 */
+/*
+ * (C) 2023 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * 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/gprs/sm/sm_qos.h>
+#include "../common/qos.h"
+
+int16_t osmo_gprs_sm_qos_parse_qos_profile(
+	struct osmo_gprs_sm_qos_profile_decoded *decoded, const uint8_t *data, size_t data_len)
+{
+	return gprs_qos_parse_qos_profile(decoded, data, data_len);
+}
+
+int16_t osmo_gprs_sm_qos_build_qos_profile(const struct osmo_gprs_sm_qos_profile_decoded *decoded, void *data, int data_len)
+{
+	return gprs_qos_build_qos_profile(decoded, data, data_len);
+}