add simplistic IuUP FSM and strip/add IuUP headers

This should really be using the FSM in libosmocore/laforge/iu_up: take the best
of both sides and integate in the libosmocore FSM implementation, then use it
here.
- in libosmocore, the FSM definition is nicer.
- here, we have correct header checksums.

Introduce using msgb to receive, pass and send RTP packets.

Add/strip IuUP from RTP data (for which msgb is particularly useful).

The payload type on an IuUP conn is maintained as negotiated in the IuUP
Initialization. For the pure RTP side, an SDP "AMR" ptmap attribute is looked
up, so that payload type numbers are translated between IuUP <-> RTP.

Change-Id: Ibc70e0aa00476926dd1f4ea8139c34f31f9cdfa3

configure.ac

@@ -195,6 +195,7 @@ AC_OUTPUT(
     tests/atlocal
     tests/mgcp_client/Makefile
     tests/mgcp/Makefile
+    tests/iuup/Makefile
     doc/Makefile
     doc/examples/Makefile
     doc/manuals/Makefile

include/osmocom/mgcp/Makefile.am

@@ -7,4 +7,6 @@ noinst_HEADERS = \
 	mgcp_sdp.h \
 	mgcp_codec.h \
 	debug.h \
+	iuup_cn_node.h \
+	iuup_protocol.h \
 	$(NULL)

include/osmocom/mgcp/debug.h

@@ -29,6 +29,7 @@
 /* Debug Areas of the code */
 enum {
 	DRTP,
+	DIUUP,
 	Debug_LastEntry,
 };
 

include/osmocom/mgcp/iuup_cn_node.h

@@ -0,0 +1,47 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+/* IuUP CN node, minimal implementation */
+
+/*                                            _____IuUP_CN_____
+ *                                            |               |
+ * UE <--> RNC --PDU-> osmo_iuup_cn_rx_pdu() -+->           ---+-> rx_payload()
+ *          |                                 |               |
+ *          |  <-PDU-- tx_msg() <-------------+--           <-+--- osmo_iuup_cn_tx_payload()
+ *                                            |               |
+ *                                            -----------------
+ */
+
+#pragma once
+
+struct msgb;
+
+typedef int (*osmo_iuup_data_cb_t)(struct msgb *msg, void *node_priv);
+
+struct osmo_iuup_cn_cfg {
+	void *node_priv;
+
+	/* When the IuUP peer sent a voice packet, the clean RTP without the IuUP header is fed to this
+	 * callback. */
+	osmo_iuup_data_cb_t rx_payload;
+
+	/* IuUP handler requests that a PDU shall be sent to the IuUP peer (e.g. the RNC).
+	 * It is guaranteed that the msgb->dst pointer is preserved or copied from the msgb that
+	 * originated the request. */
+	osmo_iuup_data_cb_t tx_msg;
+};
+
+struct osmo_iuup_cn {
+	struct osmo_iuup_cn_cfg cfg;
+	char *name;
+	uint8_t next_frame_nr;
+	int rtp_payload_type;
+};
+
+bool osmo_iuup_cn_is_iuup_init(struct msgb *msg);
+
+struct osmo_iuup_cn *osmo_iuup_cn_init(void *ctx, struct osmo_iuup_cn_cfg *cfg,
+				       const char *name_fmt, ...);
+void osmo_iuup_cn_free(struct osmo_iuup_cn *cn);
+
+int osmo_iuup_cn_tx_payload(struct osmo_iuup_cn *cn, struct msgb *payload);
+
+int osmo_iuup_cn_rx_pdu(struct osmo_iuup_cn *cn, struct msgb *pdu);

include/osmocom/mgcp/iuup_protocol.h

@@ -0,0 +1,117 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+/* IuUP protocol handling, minimal implementation */
+
+#pragma once
+
+#include <osmocom/core/endian.h>
+#include <osmocom/core/msgb.h>
+
+#define OSMO_IUUP_HEADROOM 32
+
+enum osmo_iuup_pdu_type {
+	OSMO_IUUP_PDU_DATA_WITH_CRC = 0,
+	OSMO_IUUP_PDU_CONTROL_PROCEDURE = 14,
+};
+
+enum osmo_iuup_acknack {
+	OSMO_IUUP_ACKNACK_PROCEDURE = 0,
+	OSMO_IUUP_ACKNACK_ACK = 1,
+	OSMO_IUUP_ACKNACK_NACK = 2,
+};
+
+enum osmo_iuup_procedure {
+	OSMO_IUUP_PROC_INITIALIZATION = 0,
+	OSMO_IUUP_PROC_RATE_CONTROL = 1,
+	OSMO_IUUP_PROC_TIME_ALIGNMENT = 2,
+	OSMO_IUUP_PROC_ERROR_EVENT = 3,
+};
+
+enum osmo_iuup_frame_good {
+	OSMO_IUUP_FRAME_GOOD = 0,
+	OSMO_IUUP_FRAME_BAD = 1,
+	OSMO_IUUP_FRAME_BAD_DUE_TO_RADIO = 2,
+};
+
+struct osmo_iuup_hdr_ctrl {
+#if OSMO_IS_BIG_ENDIAN
+	uint8_t pdu_type:4,
+		ack_nack:2,
+		frame_nr:2;
+	uint8_t mode_version:4,
+		procedure:4;
+	uint8_t header_crc:6,
+		payload_crc_hi:2;
+	uint8_t payload_crc_lo;
+	uint8_t payload[0];
+#elif OSMO_IS_LITTLE_ENDIAN
+	uint8_t frame_nr:2,
+		ack_nack:2,
+		pdu_type:4;
+	uint8_t procedure:4,
+		mode_version:4;
+	uint8_t payload_crc_hi:2,
+		header_crc:6;
+	uint8_t payload_crc_lo;
+	uint8_t payload[0];
+#endif
+} __attribute__((packed));
+
+union osmo_iuup_hdr_ctrl_payload {
+	struct {
+#if OSMO_IS_BIG_ENDIAN
+	uint8_t spare:3,
+		iptis_present:1,
+		subflows:3,
+		chain:1;
+#elif OSMO_IS_LITTLE_ENDIAN
+	uint8_t spare:3,
+		iptis_present:1,
+		subflows:3,
+		chain:1;
+#endif
+	} initialization;
+
+	struct {
+#if OSMO_IS_BIG_ENDIAN
+	uint8_t error_distance:2,
+		error_cause:6;
+#elif OSMO_IS_LITTLE_ENDIAN
+	uint8_t error_cause:6,
+		error_distance:2;
+#endif
+	} error_event;
+};
+
+extern const struct value_string osmo_iuup_error_cause_names[];
+static inline const char *osmo_iuup_error_cause_name(uint8_t val)
+{ return get_value_string(osmo_iuup_error_cause_names, val); }
+
+struct osmo_iuup_hdr_data {
+#if OSMO_IS_BIG_ENDIAN
+	uint8_t pdu_type:4,
+		frame_nr:4;
+	uint8_t frame_good:2,
+		rfci:6;
+	uint8_t header_crc:6,
+		payload_crc_hi:2;
+	uint8_t payload_crc_lo;
+#elif OSMO_IS_LITTLE_ENDIAN
+	uint8_t frame_nr:4,
+		pdu_type:4;
+	uint8_t rfci:6,
+		frame_good:2;
+	uint8_t payload_crc_hi:2,
+		header_crc:6;
+	uint8_t payload_crc_lo;
+#endif
+	uint8_t payload[0];
+} __attribute__((packed));
+
+int osmo_iuup_classify(bool log_errors,
+		       const char *log_label,
+		       struct msgb *pdu,
+		       struct osmo_iuup_hdr_ctrl **is_ctrl,
+		       struct osmo_iuup_hdr_data **is_data);
+bool osmo_iuup_is_init(struct msgb *pdu);
+void osmo_iuup_make_init_ack(struct msgb *ack);
+void osmo_iuup_set_checksums(uint8_t *iuup_header_and_payload, unsigned int header_and_payload_len);

include/osmocom/mgcp/mgcp_codec.h

@@ -5,3 +5,5 @@ void mgcp_codec_reset_all(struct mgcp_conn_rtp *conn);
 int mgcp_codec_add(struct mgcp_conn_rtp *conn, int payload_type, const char *audio_name, const struct mgcp_codec_param *param);
 int mgcp_codec_decide(struct mgcp_conn_rtp *conn);
 int mgcp_codec_pt_translate(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst, int payload_type);
+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);

include/osmocom/mgcp/mgcp_endp.h

@@ -23,15 +23,27 @@
 
 #pragma once
 
+#include <osmocom/core/msgb.h>
+
 struct sockaddr_in;
 struct mgcp_conn;
+struct mgcp_conn_rtp;
 struct mgcp_endpoint;
 
-/* Callback type for RTP dispatcher functions
-   (e.g mgcp_dispatch_rtp_bridge_cb, see below) */
-typedef int (*mgcp_dispatch_rtp_cb) (int proto, struct sockaddr_in *addr,
-				     char *buf, unsigned int buf_size,
-				     struct mgcp_conn *conn);
+struct osmo_rtp_msg_ctx {
+	int proto;
+	struct mgcp_conn_rtp *conn_src;
+	struct sockaddr_in *from_addr;
+};
+
+#define OSMO_RTP_MSG_CTX(MSGB) (*(struct osmo_rtp_msg_ctx**)&((MSGB)->dst))
+
+#define LOG_ENDP(endp, level, fmt, args...) \
+	LOGP(DRTP, level, "%x@ " fmt, ENDPOINT_NUMBER(endp), ## args)
+
+/* Callback type for RTP dispatcher functions (e.g mgcp_dispatch_rtp_bridge_cb, see below).
+ * The OSMO_RTP_MSG_CTX() should be set appropriately on the msg. */
+typedef int (*mgcp_dispatch_rtp_cb) (struct msgb *msg);
 
 /* Callback type for endpoint specific cleanup actions. This function
  * is automatically executed when a connection is freed (see mgcp_conn_free()

include/osmocom/mgcp/mgcp_internal.h

@@ -37,6 +37,13 @@
 #define CONN_ID_BTS "0"
 #define CONN_ID_NET "1"
 
+#define LOG_CONN(conn, level, fmt, args...) \
+	LOGP(DRTP, level, "(%d@ I:%s) " fmt, \
+	     ENDPOINT_NUMBER((conn)->endp), (conn)->id, ## args)
+
+#define LOG_CONN_RTP(conn_rtp, level, fmt, args...) \
+	LOG_CONN(conn_rtp->conn, level, fmt, ## args)
+
 enum mgcp_trunk_type {
 	MGCP_TRUNK_VIRTUAL,
 	MGCP_TRUNK_E1,
@@ -204,6 +211,8 @@ struct mgcp_conn_rtp {
 	} osmux;
 
 	struct rate_ctr_group *rate_ctr_group;
+
+	struct osmo_iuup_cn *iuup;
 };
 
 /*! Connection type, specifies which member of the union "u" in mgcp_conn
@@ -266,11 +275,10 @@ struct mgcp_parse_data {
 };
 
 int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
-	      char *buf, int rc, struct mgcp_conn_rtp *conn_src,
+	      struct msgb *msg, struct mgcp_conn_rtp *conn_src,
 	      struct mgcp_conn_rtp *conn_dst);
 int mgcp_send_dummy(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn);
-int mgcp_dispatch_rtp_bridge_cb(int proto, struct sockaddr_in *addr, char *buf,
-				unsigned int buf_size, struct mgcp_conn *conn);
+int mgcp_dispatch_rtp_bridge_cb(struct msgb *msg);
 void mgcp_cleanup_rtp_bridge_cb(struct mgcp_endpoint *endp, struct mgcp_conn *conn);
 int mgcp_bind_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port,
 			   struct mgcp_conn_rtp *conn);
@@ -350,3 +358,8 @@ LOGP(cat, level, "endpoint:0x%x " fmt, \
 LOGPENDP((conn)->endp, cat, level, "CI:%s " fmt, \
          (conn)->id, \
          ## args)
+
+void mgcp_patch_and_count(struct mgcp_endpoint *endp,
+			  struct mgcp_rtp_state *state,
+			  struct mgcp_rtp_end *rtp_end,
+			  struct sockaddr_in *addr, struct msgb *msg);

src/libosmo-mgcp-client/mgcp_client.c

@@ -337,48 +337,34 @@ static int mgcp_parse_audio_ptime_rtpmap(struct mgcp_response *r, const char *li
 {
 	unsigned int pt;
 	char codec_resp[64];
-	unsigned int codec;
+	enum mgcp_codecs codec;
 
+#define A_PTIME "a=ptime:"
+#define A_RTPMAP "a=rtpmap:"
 
-	if (strstr(line, "ptime")) {
-		if (sscanf(line, "a=ptime:%u", &r->ptime) != 1)
-			goto response_parse_failure_ptime;
-	} else if (strstr(line, "rtpmap")) {
-		if (sscanf(line, "a=rtpmap:%d %63s", &pt, codec_resp) == 2) {
-			/* The MGW may assign an own payload type in the
-			 * response if the choosen codec falls into the IANA
-			 * assigned dynamic payload type range (96-127).
-			 * Normally the MGW should obey the 3gpp payload type
-			 * assignments, which are fixed, so we likely wont see
-			 * anything unexpected here. In order to be sure that
-			 * we will now check the codec string and if the result
-			 * does not match to what is IANA / 3gpp assigned, we
-			 * will create an entry in the ptmap table so we can
-			 * lookup later what has been assigned. */
-			codec = map_str_to_codec(codec_resp);
-			if (codec != pt) {
-				if (r->ptmap_len < ARRAY_SIZE(r->ptmap)) {
-					r->ptmap[r->ptmap_len].pt = pt;
-					r->ptmap[r->ptmap_len].codec = codec;
-					r->ptmap_len++;
-				} else
-					goto response_parse_failure_rtpmap;
-			}
-
-		} else
-			goto response_parse_failure_rtpmap;
+	if (osmo_str_startswith(line, A_PTIME)) {
+		if (sscanf(line, A_PTIME "%u", &r->ptime) != 1) {
+			LOGP(DLMGCP, LOGL_ERROR,
+			     "Failed to parse SDP parameter, invalid ptime (%s)\n", line);
+			return -EINVAL;
+		}
+	} else if (osmo_str_startswith(line, A_RTPMAP)) {
+		if (sscanf(line, A_RTPMAP "%d %63s", &pt, codec_resp) != 2) {
+			LOGP(DLMGCP, LOGL_ERROR,
+			     "Failed to parse SDP parameter, invalid rtpmap: %s\n", osmo_quote_str(line, -1));
+			return -EINVAL;
+		}
+		if (r->ptmap_len >= ARRAY_SIZE(r->ptmap)) {
+			LOGP(DLMGCP, LOGL_ERROR, "No more space in ptmap array (len=%u)\n", r->ptmap_len);
+			return -ENOSPC;
+		}
+		codec = map_str_to_codec(codec_resp);
+		r->ptmap[r->ptmap_len].pt = pt;
+		r->ptmap[r->ptmap_len].codec = codec;
+		r->ptmap_len++;
 	}
 
 	return 0;
-
-response_parse_failure_ptime:
-	LOGP(DLMGCP, LOGL_ERROR,
-	     "Failed to parse SDP parameter, invalid ptime (%s)\n", line);
-	return -EINVAL;
-response_parse_failure_rtpmap:
-	LOGP(DLMGCP, LOGL_ERROR,
-	     "Failed to parse SDP parameter, invalid rtpmap (%s)\n", line);
-	return -EINVAL;
 }
 
 /* Parse a line like "c=IN IP4 10.11.12.13" */

src/libosmo-mgcp/Makefile.am

@@ -40,4 +40,6 @@ libosmo_mgcp_a_SOURCES = \
 	mgcp_conn.c \
 	mgcp_stat.c \
 	mgcp_endp.c \
+	iuup_protocol.c \
+	iuup_cn_node.c \
 	$(NULL)

src/libosmo-mgcp/iuup_cn_node.c

@@ -0,0 +1,211 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+/* IuUP Core Network side protocol handling, minimal implementation */
+
+/*
+ * (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Neels Hofmeyr <neels@hofmeyr.de>
+ *
+ * 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 <talloc.h>
+#include <errno.h>
+#include <string.h>
+#include <arpa/inet.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+
+#include <osmocom/netif/rtp.h>
+
+#include <osmocom/mgcp/iuup_cn_node.h>
+#include <osmocom/mgcp/iuup_protocol.h>
+
+#include <osmocom/mgcp/debug.h>
+
+#define LOG_IUUP_CN(cn, level, fmt, args...) \
+		LOGP(DIUUP, level, "(%s) " fmt, (cn)->name, ## args)
+
+struct osmo_iuup_cn *osmo_iuup_cn_init(void *ctx, struct osmo_iuup_cn_cfg *cfg,
+				       const char *name_fmt, ...)
+{
+	va_list ap;
+	struct osmo_iuup_cn *cn = talloc_zero(ctx, struct osmo_iuup_cn);
+	OSMO_ASSERT(cn);
+
+	cn->cfg = *cfg;
+
+	if (!name_fmt)
+		name_fmt = "-";
+
+	va_start(ap, name_fmt);
+	cn->name = talloc_vasprintf(cn, name_fmt, ap);
+	va_end(ap);
+
+	LOGP(DIUUP, LOGL_INFO, "(%s) Initializing IuUP node\n", cn->name);
+
+	if (!osmo_identifier_valid(cn->name)) {
+		LOGP(DIUUP, LOGL_ERROR, "Attempting to set illegal id for IuUP CN instance: %s\n",
+		     osmo_quote_str(cn->name, -1));
+		talloc_free(cn);
+		return NULL;
+	}
+
+	return cn;
+}
+
+void osmo_iuup_cn_free(struct osmo_iuup_cn *cn)
+{
+	talloc_free(cn);
+}
+
+static int rx_data(struct osmo_iuup_cn *cn, struct msgb *pdu,
+		   struct osmo_iuup_hdr_data *hdr)
+{
+	/* Remove the IuUP bit from the middle of the buffer by writing the RTP header forward. */
+	/* And append AMR 12.2k header "0xf03c". - AD HOC fix */
+	unsigned int pre_hdr_len = ((uint8_t*)hdr) - pdu->data;
+	memmove(pdu->data + sizeof(*hdr) - 2, pdu->data, pre_hdr_len);
+	((uint8_t*)hdr)[2] = 0xf0;
+	((uint8_t*)hdr)[3] = 0x3c;
+	msgb_pull(pdu, sizeof(*hdr) - 2);
+
+	LOGP(DIUUP, LOGL_DEBUG, "(%s) IuUP stripping IuUP header from RTP data\n", cn->name);
+	cn->cfg.rx_payload(pdu, cn->cfg.node_priv);
+
+	return 0;
+}
+
+static int tx_init_ack(struct osmo_iuup_cn *cn, struct msgb *src_pdu)
+{
+	/* Send Initialization Ack PDU back to the sender */
+	int rc;
+	struct msgb *ack = msgb_alloc(4096, "IuUP Initialization Ack");
+	OSMO_ASSERT(ack);
+	ack->dst = src_pdu->dst;
+
+	/* Just copy the RTP header that was sent... TODO: tweak some RTP values?? */
+	memcpy(msgb_put(ack, sizeof(struct rtp_hdr)), src_pdu->data, sizeof(struct rtp_hdr));
+
+	osmo_iuup_make_init_ack(ack);
+
+	LOGP(DIUUP, LOGL_DEBUG, "(%s) Sending Initialization ACK %p\n", cn->name, cn->cfg.node_priv);
+	rc = cn->cfg.tx_msg(ack, cn->cfg.node_priv);
+	msgb_free(ack);
+	return rc;
+}
+
+static int rx_control(struct osmo_iuup_cn *cn, struct msgb *pdu,
+		      struct osmo_iuup_hdr_ctrl *hdr)
+{
+	switch (hdr->procedure) {
+	case OSMO_IUUP_PROC_INITIALIZATION:
+		switch (hdr->ack_nack) {
+		case OSMO_IUUP_ACKNACK_PROCEDURE:
+			LOGP(DIUUP, LOGL_INFO, "(%s) Rx IuUP Initialization, sending ACK\n", cn->name);
+			cn->rtp_payload_type = ((struct rtp_hdr*)pdu->data)->payload_type;
+			return tx_init_ack(cn, pdu);
+
+		default:
+			LOGP(DIUUP, LOGL_DEBUG, "(%s) Rx IuUP Initialization, unhandled ack_nack = %d\n",
+			     cn->name, hdr->ack_nack);
+			break;
+		}
+		/* Continue to log "unexpected procedure" below. */
+		break;
+
+	case OSMO_IUUP_PROC_ERROR_EVENT:
+		{
+			union osmo_iuup_hdr_ctrl_payload *p = (void*)hdr->payload;
+			LOGP(DIUUP, LOGL_ERROR,
+			     "(%s) Rx IuUP Error Event: distance=%u, cause=%u=\"%s\"\n",
+			     cn->name, p->error_event.error_distance, p->error_event.error_cause,
+			     osmo_iuup_error_cause_name(p->error_event.error_cause));
+			return 0;
+		}
+
+	default:
+		break;
+	}
+	LOG_IUUP_CN(cn, LOGL_ERROR,
+		    "Rx control PDU with unexpected procedure: 0x%x acknack=0x%x\n",
+		    hdr->procedure, hdr->ack_nack);
+	return -EINVAL;
+}
+
+/* Feed a received PDU to the IuUP CN node. This function takes ownership of the msgb, it must not be
+ * freed by the caller. */
+int osmo_iuup_cn_rx_pdu(struct osmo_iuup_cn *cn, struct msgb *pdu)
+{
+	struct osmo_iuup_hdr_ctrl *is_ctrl;
+	struct osmo_iuup_hdr_data *is_data;
+	int rc;
+
+	rc = osmo_iuup_classify(true, cn->name, pdu, &is_ctrl, &is_data);
+	if (rc)
+		return rc;
+
+	if (is_ctrl)
+		return rx_control(cn, pdu, is_ctrl);
+	if (is_data)
+		return rx_data(cn, pdu, is_data);
+	return rc;
+}
+
+static uint8_t next_frame_nr(struct osmo_iuup_cn *cn)
+{
+	uint8_t frame_nr = cn->next_frame_nr;
+	cn->next_frame_nr = (frame_nr + 1) & 0x0f;
+	return frame_nr;
+}
+
+/* Send this RTP packet to the IuUP peer: add IuUP header and call the tx_msg() to transmit the resulting
+ * message to the IuUP peer.
+ * Returns 0 on success, negative on error. */
+int osmo_iuup_cn_tx_payload(struct osmo_iuup_cn *cn, struct msgb *pdu)
+{
+	struct rtp_hdr *rtp_was, *rtp;
+	struct osmo_iuup_hdr_data *iuup_hdr;
+
+	/* Splice an IuUP header in between RTP header and payload data */
+	rtp_was = (void*)pdu->data;
+
+	/* copy the RTP header part backwards by the size needed for the IuUP header */
+	/* also strips 2 bytes from the front of RTP payload - AMR header - AD HOC fix */
+	rtp = (void*)msgb_push(pdu, sizeof(*iuup_hdr) - 2);
+	memmove(rtp, rtp_was, sizeof(*rtp));
+
+	/* The IuUP side negotiated a payload type number to use during Initialization. The RTP packet going to the IuUP
+	 * peer should reflect this payload_type. This should already have happened in mgcp_patch_pt(), but can't hurt
+	 * to patch over it again. */
+	rtp->payload_type = cn->rtp_payload_type;
+
+	iuup_hdr = (void*)rtp->data;
+
+	*iuup_hdr = (struct osmo_iuup_hdr_data){
+		.pdu_type = OSMO_IUUP_PDU_DATA_WITH_CRC,
+		.frame_nr = next_frame_nr(cn),
+		.frame_good = OSMO_IUUP_FRAME_GOOD,
+	};
+
+	osmo_iuup_set_checksums((uint8_t*)iuup_hdr, pdu->tail - (uint8_t*)iuup_hdr);
+	LOGP(DIUUP, LOGL_DEBUG, "(%s) IuUP inserting IuUP header in RTP data (frame nr %u)\n",
+	     cn->name, iuup_hdr->frame_nr);
+
+	return cn->cfg.tx_msg(pdu, cn->cfg.node_priv);
+}

src/libosmo-mgcp/iuup_protocol.c

@@ -0,0 +1,286 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+/* IuUP Core Network side protocol, minimal implementation */
+
+/*
+ * (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Neels Hofmeyr <neels@hofmeyr.de>
+ *
+ * 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 <errno.h>
+#include <osmocom/mgcp/iuup_protocol.h>
+#include <osmocom/mgcp/debug.h>
+#include <osmocom/netif/rtp.h>
+
+/* Calculating two bytes of CRC is ok to do by a loop */
+static uint8_t header_crc6(const uint8_t *hdr)
+{
+    int bit;
+    /* Polynomial: D^6 + D^5 + D^3 + D^2 + D^1 + 1
+     * that's 1101111 or 0x6f;
+     * align its lowest bit with a uint16_t's highest bit: */
+    uint32_t polynomial = 0x6f << 15; // 00110111 10000000 00000000
+    uint32_t remainder = ( ((uint32_t)hdr[0]) << 8 | hdr[1] ) << 6;
+
+    for (bit = 15; bit >= 0; bit--)
+    {
+        if (remainder & (0x40 << bit))
+            remainder ^= polynomial;
+        polynomial >>= 1;
+    }
+
+    return remainder;
+}
+
+/*
+ * Charles Michael Heard's CRC-10 code, from
+ *
+ *      http://web.archive.org/web/20061005231950/http://cell-relay.indiana.edu/cell-relay/publications/software/CRC/crc10.html
+ *
+ * with the CRC table initialized with values computed by
+ * his "gen_byte_crc10_table()" routine, rather than by calling that
+ * routine at run time, and with various data type cleanups.
+ */
+static const uint16_t byte_crc10_table[256] = {
+	0x0000, 0x0233, 0x0255, 0x0066, 0x0299, 0x00aa, 0x00cc, 0x02ff,
+	0x0301, 0x0132, 0x0154, 0x0367, 0x0198, 0x03ab, 0x03cd, 0x01fe,
+	0x0031, 0x0202, 0x0264, 0x0057, 0x02a8, 0x009b, 0x00fd, 0x02ce,
+	0x0330, 0x0103, 0x0165, 0x0356, 0x01a9, 0x039a, 0x03fc, 0x01cf,
+	0x0062, 0x0251, 0x0237, 0x0004, 0x02fb, 0x00c8, 0x00ae, 0x029d,
+	0x0363, 0x0150, 0x0136, 0x0305, 0x01fa, 0x03c9, 0x03af, 0x019c,
+	0x0053, 0x0260, 0x0206, 0x0035, 0x02ca, 0x00f9, 0x009f, 0x02ac,
+	0x0352, 0x0161, 0x0107, 0x0334, 0x01cb, 0x03f8, 0x039e, 0x01ad,
+	0x00c4, 0x02f7, 0x0291, 0x00a2, 0x025d, 0x006e, 0x0008, 0x023b,
+	0x03c5, 0x01f6, 0x0190, 0x03a3, 0x015c, 0x036f, 0x0309, 0x013a,
+	0x00f5, 0x02c6, 0x02a0, 0x0093, 0x026c, 0x005f, 0x0039, 0x020a,
+	0x03f4, 0x01c7, 0x01a1, 0x0392, 0x016d, 0x035e, 0x0338, 0x010b,
+	0x00a6, 0x0295, 0x02f3, 0x00c0, 0x023f, 0x000c, 0x006a, 0x0259,
+	0x03a7, 0x0194, 0x01f2, 0x03c1, 0x013e, 0x030d, 0x036b, 0x0158,
+	0x0097, 0x02a4, 0x02c2, 0x00f1, 0x020e, 0x003d, 0x005b, 0x0268,
+	0x0396, 0x01a5, 0x01c3, 0x03f0, 0x010f, 0x033c, 0x035a, 0x0169,
+	0x0188, 0x03bb, 0x03dd, 0x01ee, 0x0311, 0x0122, 0x0144, 0x0377,
+	0x0289, 0x00ba, 0x00dc, 0x02ef, 0x0010, 0x0223, 0x0245, 0x0076,
+	0x01b9, 0x038a, 0x03ec, 0x01df, 0x0320, 0x0113, 0x0175, 0x0346,
+	0x02b8, 0x008b, 0x00ed, 0x02de, 0x0021, 0x0212, 0x0274, 0x0047,
+	0x01ea, 0x03d9, 0x03bf, 0x018c, 0x0373, 0x0140, 0x0126, 0x0315,
+	0x02eb, 0x00d8, 0x00be, 0x028d, 0x0072, 0x0241, 0x0227, 0x0014,
+	0x01db, 0x03e8, 0x038e, 0x01bd, 0x0342, 0x0171, 0x0117, 0x0324,
+	0x02da, 0x00e9, 0x008f, 0x02bc, 0x0043, 0x0270, 0x0216, 0x0025,
+	0x014c, 0x037f, 0x0319, 0x012a, 0x03d5, 0x01e6, 0x0180, 0x03b3,
+	0x024d, 0x007e, 0x0018, 0x022b, 0x00d4, 0x02e7, 0x0281, 0x00b2,
+	0x017d, 0x034e, 0x0328, 0x011b, 0x03e4, 0x01d7, 0x01b1, 0x0382,
+	0x027c, 0x004f, 0x0029, 0x021a, 0x00e5, 0x02d6, 0x02b0, 0x0083,
+	0x012e, 0x031d, 0x037b, 0x0148, 0x03b7, 0x0184, 0x01e2, 0x03d1,
+	0x022f, 0x001c, 0x007a, 0x0249, 0x00b6, 0x0285, 0x02e3, 0x00d0,
+	0x011f, 0x032c, 0x034a, 0x0179, 0x0386, 0x01b5, 0x01d3, 0x03e0,
+	0x021e, 0x002d, 0x004b, 0x0278, 0x0087, 0x02b4, 0x02d2, 0x00e1
+};
+
+static uint16_t crc10(uint16_t crc10_accum, const uint8_t *payload, unsigned int payload_len)
+{
+	int i;
+
+	for (i = 0; i < payload_len; i++) {
+		crc10_accum = ((crc10_accum << 8) & 0x300)
+			^ byte_crc10_table[(crc10_accum >> 2) & 0xff]
+			^ payload[i];
+	}
+	return crc10_accum;
+}
+
+/* When a payload of a multiple of bytes has run through, we need to still feed 10 bits of zeros into the
+ * CRC10 to get the payload's checksum result that we can send to a peer. That can't be done with above
+ * table, because it acts as if full 16 bits are fed. This stops after 10 bits. */
+static uint16_t crc10_remainder(uint16_t crc10_accum)
+{
+    int bit;
+    /* Polynomial: D^10 + D^9 + D^5 + D^4 + D^1 + 1
+     * that's 11000110011 or 0x633;
+     * align its lowest bit with a 10bit value's highest bit: */
+    uint32_t polynomial = 0x633 << 9; // 1100 01100110 00000000
+    uint32_t remainder = ((uint32_t)crc10_accum) << 10;
+
+    /* Run on 10 bits */
+    for (bit = 9; bit >= 0; bit--)
+    {
+        if (remainder & ((1 << 10) << bit))
+            remainder ^= polynomial;
+        polynomial >>= 1;
+    }
+
+    return remainder & 0x3ff;
+}
+
+static uint16_t payload_crc10(const uint8_t *payload, unsigned int payload_len)
+{
+	uint16_t crc10_accum = crc10(0, payload, payload_len);
+	return crc10_remainder(crc10_accum);
+}
+
+/* Given an IuUP PDU data block, write the correct header and payload CRC checksums at the right places.
+ */
+void osmo_iuup_set_checksums(uint8_t *iuup_header_and_payload, unsigned int header_and_payload_len)
+{
+	/* For both data and ctrl, the checksums and payload are at the same offset */
+	struct osmo_iuup_hdr_data *hdr = (void*)iuup_header_and_payload;
+	uint16_t crc;
+	unsigned int payload_len;
+
+	hdr->header_crc = header_crc6(iuup_header_and_payload);
+
+	payload_len = iuup_header_and_payload + header_and_payload_len - hdr->payload;
+	crc = payload_crc10(hdr->payload, payload_len);
+	hdr->payload_crc_hi = (crc >> 8) & 0x3;
+	hdr->payload_crc_lo = crc & 0xff;
+
+}
+
+/* Validate minimum message sizes, IuUP PDU type, header- and payload checksums. If it is a Control
+ * Procedure PDU, return the header position in is_ctrl, if it is a Data PDU, return the header position
+ * in is_data. If log_errors is true, log on DIUUP with the given log label for context. Return NULL in
+ * both is_ctrl and is_data, and return a negative error code if the PDU could not be identified as a
+ * valid RTP PDU containing an IuUP part. */
+int osmo_iuup_classify(bool log_errors,
+		       const char *log_label,
+		       struct msgb *pdu,
+		       struct osmo_iuup_hdr_ctrl **is_ctrl,
+		       struct osmo_iuup_hdr_data **is_data)
+{
+	struct rtp_hdr *rtp = (void*)pdu->data;
+	struct osmo_iuup_hdr_ctrl *hdr = (void*)rtp->data;
+	unsigned int payload_len;
+	uint16_t crc_calculated;
+	uint16_t crc_from_peer;
+
+#define ERR(fmt, args...) do { \
+			if (log_errors) \
+				LOGP(DIUUP, LOGL_ERROR, "(%s) " fmt, log_label? : "-", ## args); \
+			return -EINVAL; \
+		} while (0)
+
+	if (is_ctrl)
+		*is_ctrl = NULL;
+	if (is_data)
+		*is_data = NULL;
+
+	/* We need at least a header of 4 bytes. The osmo_iuup_hdr_ctrl already includes a byte of
+	 * payload, so use osmo_iuup_hdr_data to check the minimum here. */
+	if (pdu->len < (sizeof(*rtp) + sizeof(struct osmo_iuup_hdr_data)))
+		ERR("IuUP PDU too short: %u\n", pdu->len);
+
+	/* Let's not validate checksums if the header type isn't sane */
+	switch (hdr->pdu_type) {
+	case OSMO_IUUP_PDU_DATA_WITH_CRC:
+		/* If the caller isn't interested in data PDUs, cut short here. */
+		if (!is_data)
+			return 0;
+		break;
+	case OSMO_IUUP_PDU_CONTROL_PROCEDURE:
+		/* If the caller isn't interested in control PDUs, cut short here. */
+		if (!is_ctrl)
+			return 0;
+		if (pdu->len < (sizeof(*rtp) + sizeof(struct osmo_iuup_hdr_ctrl)))
+			ERR("IuUP control PDU too short: %u\n", pdu->len);
+		break;
+	default:
+		ERR("IuUP with invalid type: %u\n", hdr->pdu_type);
+	}
+
+	/* For both data and ctrl, the checksums and payload are at the same offset */
+
+	crc_calculated = header_crc6((uint8_t*)hdr);
+	if (crc_calculated != hdr->header_crc)
+		ERR("IuUP PDU with invalid header CRC (peer sent 0x%x, calculated 0x%x)\n",
+		    hdr->header_crc, crc_calculated);
+
+	payload_len = pdu->tail - hdr->payload;
+	crc_calculated = payload_crc10(hdr->payload, payload_len);
+	crc_from_peer = (((uint16_t)hdr->payload_crc_hi) << 8) | hdr->payload_crc_lo;
+	if (crc_from_peer != crc_calculated)
+		ERR("IuUP PDU with invalid payload CRC (peer sent 0x%x, calculated 0x%x)\n",
+		    crc_from_peer, crc_calculated);
+
+	switch (hdr->pdu_type) {
+	case OSMO_IUUP_PDU_DATA_WITH_CRC:
+		if (is_data)
+			*is_data = (void*)hdr;
+		return 0;
+	case OSMO_IUUP_PDU_CONTROL_PROCEDURE:
+		if (is_ctrl)
+			*is_ctrl = hdr;
+		return 0;
+	default:
+		ERR("IuUP with invalid type: %u\n", hdr->pdu_type);
+	}
+#undef ERR
+}
+
+/* Return true if this RTP packet contains an IuUP Initialization header (detect IuUP peer). */
+bool osmo_iuup_is_init(struct msgb *pdu)
+{
+ 	struct osmo_iuup_hdr_ctrl *is_ctrl;
+	osmo_iuup_classify(false, NULL, pdu, &is_ctrl, NULL);
+	return is_ctrl
+		&& is_ctrl->procedure == OSMO_IUUP_PROC_INITIALIZATION
+		&& is_ctrl->ack_nack == OSMO_IUUP_ACKNACK_PROCEDURE;
+}
+
+/* Append an IuUP Initialization ACK message */
+void osmo_iuup_make_init_ack(struct msgb *ack)
+{
+	/* Send Initialization Ack PDU back to the sender */
+ 	struct osmo_iuup_hdr_ctrl *hdr;
+	OSMO_ASSERT(ack);
+
+	hdr = (void*)msgb_put(ack, sizeof(*hdr));
+
+	*hdr = (struct osmo_iuup_hdr_ctrl){
+		.pdu_type = OSMO_IUUP_PDU_CONTROL_PROCEDURE,
+		.ack_nack = OSMO_IUUP_ACKNACK_ACK,
+		.procedure = OSMO_IUUP_PROC_INITIALIZATION,
+	};
+
+	osmo_iuup_set_checksums((uint8_t*)hdr, sizeof(*hdr));
+}
+
+const struct value_string osmo_iuup_error_cause_names[] = {
+	{ 0, "CRC error of frame header" },
+	{ 1, "CRC error of frame payload" },
+	{ 2, "Unexpected frame number" },
+	{ 3, "Frame loss" },
+	{ 4, "PDU type unknown" },
+	{ 5, "Unknown procedure" },
+	{ 6, "Unknown reserved value" },
+	{ 7, "Unknown field" },
+	{ 8, "Frame too short" },
+	{ 9, "Missing fields" },
+	{ 16, "Unexpected PDU type" },
+	{ 17, "spare" },
+	{ 18, "Unexpected procedure" },
+	{ 19, "Unexpected RFCI" },
+	{ 20, "Unexpected value" },
+	{ 42, "Initialisation failure" },
+	{ 43, "Initialisation failure (network error, timer expiry)" },
+	{ 44, "Initialisation failure (Iu UP function error, repeated NACK)" },
+	{ 45, "Rate control failure" },
+	{ 46, "Error event failure" },
+	{ 47, "Time Alignment not supported" },
+	{ 48, "Requested Time Alignment not possible" },
+	{ 49, "Iu UP Mode version not supported" },
+	{}
+};

src/libosmo-mgcp/mgcp_codec.c

@@ -76,36 +76,61 @@ void mgcp_codec_summary(struct mgcp_conn_rtp *conn)
 }
 
 /* Initalize or reset codec information with default data. */
-void codec_init(struct mgcp_rtp_codec *codec)
+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,
+	};
+}
+
+static void codec_free(struct mgcp_rtp_codec *codec)
 {
 	if (codec->subtype_name)
 		talloc_free(codec->subtype_name);
 	if (codec->audio_name)
 		talloc_free(codec->audio_name);
-	memset(codec, 0, sizeof(*codec));
-	codec->payload_type = -1;
-	codec->frame_duration_num = DEFAULT_RTP_AUDIO_FRAME_DUR_NUM;
-	codec->frame_duration_den = DEFAULT_RTP_AUDIO_FRAME_DUR_DEN;
-	codec->rate = DEFAULT_RTP_AUDIO_DEFAULT_RATE;
-	codec->channels = DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS;
+	*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)
 {
-	memset(conn->end.codecs, 0, sizeof(conn->end.codecs));
+	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;
 }
 
-/* Set members of struct mgcp_rtp_codec, extrapolate in missing information. Param audio_name is expected in uppercase. */
-static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type, const char *audio_name,
-		     unsigned int pt_offset, const struct mgcp_codec_param *param)
+/*! 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;
 	char audio_codec[64];
+	struct mgcp_rtp_codec *codec;
+	unsigned int pt_offset = conn->end.codecs_assigned;
+	void *ctx = conn->conn;
+
+	/* 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);
@@ -113,12 +138,13 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 	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)
-			goto error;
-		if (payload_type >= 72 && payload_type <= 76)
-			goto error;
-		if (payload_type >= 127)
+		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;
 	}
@@ -144,6 +170,8 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 			/* 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;
 		}
 	}
@@ -151,16 +179,23 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 	/* 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(audio_name) > sizeof(audio_codec))
+	if (strlen(audio_name) > sizeof(audio_codec)) {
+		LOGP(DLMGCP, LOGL_ERROR, "Audio codec too long: %s\n", osmo_quote_str(audio_name, -1));
 		goto error;
+	}
 	channels = DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS;
 	rate = DEFAULT_RTP_AUDIO_DEFAULT_RATE;
-	if (sscanf(audio_name, "%63[^/]/%d/%d", audio_codec, &rate, &channels) < 1)
+	if (sscanf(audio_name, "%63[^/]/%d/%d", audio_codec, &rate, &channels) < 1) {
+		LOGP(DLMGCP, LOGL_ERROR, "Invalid audio codec: %s\n", osmo_quote_str(audio_name, -1));
 		goto error;
+	}
 
 	/* Note: We only accept configurations with one audio channel! */
-	if (channels != 1)
+	if (channels != 1) {
+		LOGP(DLMGCP, LOGL_ERROR, "Cannot handle audio codec with more than one channel: %s\n",
+		     osmo_quote_str(audio_name, -1));
 		goto error;
+	}
 
 	codec->rate = rate;
 	codec->channels = channels;
@@ -178,6 +213,7 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 
 	/* 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 */
@@ -213,9 +249,14 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 		 * 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)
+			if (codec->payload_type > 109) {
+				LOGP(DLMGCP, LOGL_ERROR, "Ran out of payload type numbers to assign dynamically\n");
 				goto error;
+			}
 		}
 	}
 
@@ -226,41 +267,14 @@ static int codec_set(void *ctx, struct mgcp_rtp_codec *codec, int payload_type,
 	} else
 		codec->param_present = false;
 
+	conn->end.codecs_assigned++;
 	return 0;
 error:
 	/* Make sure we leave a clean codec entry on error. */
-	codec_init(codec);
-	memset(codec, 0, sizeof(*codec));
+	codec_free(codec);
 	return -EINVAL;
 }
 
-/*! 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 rc;
-
-	/* 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;
-
-	rc = codec_set(conn->conn, &conn->end.codecs[conn->end.codecs_assigned], payload_type, audio_name,
-		       conn->end.codecs_assigned, param);
-	if (rc != 0)
-		return -EINVAL;
-
-	conn->end.codecs_assigned++;
-
-	return 0;
-}
-
 /* 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)
@@ -350,6 +364,25 @@ int mgcp_codec_decide(struct mgcp_conn_rtp *conn)
 	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
+ */
+static bool 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)
@@ -362,10 +395,12 @@ static bool codecs_same(struct mgcp_rtp_codec *codec_a, struct mgcp_rtp_codec *c
 		return false;
 	if (codec_a->frame_duration_den != codec_b->frame_duration_den)
 		return false;
-	if (strcmp(codec_a->audio_name, codec_b->audio_name))
-		return false;
 	if (strcmp(codec_a->subtype_name, codec_b->subtype_name))
 		return false;
+	if (!strcmp(codec_a->subtype_name, "AMR")) {
+		if (amr_is_octet_aligned(codec_a) != amr_is_octet_aligned(codec_b))
+			return false;
+	}
 
 	return true;
 }
@@ -416,3 +451,19 @@ int mgcp_codec_pt_translate(struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp
 
 	return codec_dst->payload_type;
 }
+
+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;
+}

src/libosmo-mgcp/mgcp_conn.c

@@ -129,6 +129,7 @@ static void mgcp_rtp_conn_cleanup(struct mgcp_conn_rtp *conn_rtp)
 		conn_osmux_disable(conn_rtp);
 	mgcp_free_rtp_port(&conn_rtp->end);
 	rate_ctr_group_free(conn_rtp->rate_ctr_group);
+	mgcp_codec_reset_all(conn_rtp);
 }
 
 void mgcp_conn_watchdog_cb(void *data)

src/libosmo-mgcp/mgcp_network.c

@@ -45,6 +45,8 @@
 #include <osmocom/mgcp/mgcp_codec.h>
 #include <osmocom/mgcp/debug.h>
 #include <osmocom/codec/codec.h>
+#include <osmocom/mgcp/iuup_cn_node.h>
+#include <osmocom/mgcp/iuup_protocol.h>
 
 
 #define RTP_SEQ_MOD		(1 << 16)
@@ -52,11 +54,13 @@
 #define RTP_MAX_MISORDER	100
 #define RTP_BUF_SIZE		4096
 
-enum {
+enum rtp_proto {
 	MGCP_PROTO_RTP,
 	MGCP_PROTO_RTCP,
 };
 
+static int rx_rtp(struct msgb *msg);
+
 /*! Determine the local rtp bind IP-address.
  *  \param[out] addr caller provided memory to store the resulting IP-Address
  *  \param[in] endp mgcp endpoint, that holds a copy of the VTY parameters
@@ -469,19 +473,43 @@ void mgcp_rtp_annex_count(struct mgcp_endpoint *endp,
  * Patch the payload type of an RTP packet so that it uses the payload type
  * that is valid for the destination connection (conn_dst) */
 static int mgcp_patch_pt(struct mgcp_conn_rtp *conn_src,
-			 struct mgcp_conn_rtp *conn_dst, char *data, int len)
+			 struct mgcp_conn_rtp *conn_dst, struct msgb *msg)
 {
 	struct rtp_hdr *rtp_hdr;
 	uint8_t pt_in;
 	int pt_out;
 
-	OSMO_ASSERT(len >= sizeof(struct rtp_hdr));
-	rtp_hdr = (struct rtp_hdr *)data;
-
-	pt_in = rtp_hdr->payload_type;
-	pt_out = mgcp_codec_pt_translate(conn_src, conn_dst, pt_in);
-	if (pt_out < 0)
+	if (msg->len < sizeof(struct rtp_hdr)) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTP packet too short (%u < %zu)\n",
+			     msg->len, sizeof(struct rtp_hdr));
 		return -EINVAL;
+	}
+
+	rtp_hdr = (struct rtp_hdr *)msg->data;
+
+	if (conn_src->iuup) {
+		/* The source is an IuUP payload. We have received a dynamic payload type number on the IuUP side, and
+		 * towards the pure RTP side it should go out as "AMR/8000". Make sure that the payload type number in
+		 * the RTP packet matches the a=rtpmap:N payload type number configured for AMR. */
+		const struct mgcp_rtp_codec *amr_codec = mgcp_codec_pt_find_by_subtype_name(conn_dst, "AMR", 0);
+
+		if (!amr_codec) {
+			/* There is no AMR codec configured on the outgoing conn. */
+			return -EINVAL;
+		}
+
+		pt_out = amr_codec->payload_type;
+	} else if (conn_dst->iuup) {
+		/* The destination is an IuUP payload. Use whatever payload number was negotiated during IuUP
+		 * Initialization. */
+		pt_out = conn_dst->iuup->rtp_payload_type;
+	} else {
+		/* Both sides are normal RTP payloads. Consult the rtpmap settings received by SDP. */
+		pt_in = rtp_hdr->payload_type;
+		pt_out = mgcp_codec_pt_translate(conn_src, conn_dst, pt_in);
+		if (pt_out < 0)
+			return -EINVAL;
+	}
 
 	rtp_hdr->payload_type = (uint8_t) pt_out;
 	return 0;
@@ -496,7 +524,7 @@ static int mgcp_patch_pt(struct mgcp_conn_rtp *conn_src,
 void mgcp_patch_and_count(struct mgcp_endpoint *endp,
 			  struct mgcp_rtp_state *state,
 			  struct mgcp_rtp_end *rtp_end,
-			  struct sockaddr_in *addr, char *data, int len)
+			  struct sockaddr_in *addr, struct msgb *msg)
 {
 	uint32_t arrival_time;
 	int32_t transit;
@@ -504,11 +532,12 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp,
 	uint32_t timestamp, ssrc;
 	struct rtp_hdr *rtp_hdr;
 	int payload = rtp_end->codec->payload_type;
+	unsigned int len = msg->len;
 
 	if (len < sizeof(*rtp_hdr))
 		return;
 
-	rtp_hdr = (struct rtp_hdr *)data;
+	rtp_hdr = (struct rtp_hdr *)msg->data;
 	seq = ntohs(rtp_hdr->sequence);
 	timestamp = ntohl(rtp_hdr->timestamp);
 	arrival_time = get_current_ts(rtp_end->codec->rate);
@@ -641,7 +670,7 @@ void mgcp_patch_and_count(struct mgcp_endpoint *endp,
  * the receiving end expects GSM-HR data to be formated after RFC 5993, this
  * function is used to convert between RFC 5993 and TS 101318, which we normally
  * use. */
-static void rfc5993_hr_convert(struct mgcp_endpoint *endp, char *data, int *len)
+static int rfc5993_hr_convert(struct mgcp_endpoint *endp, char *data, int *len)
 {
 	/* NOTE: *data has an overall length of RTP_BUF_SIZE, so there is
 	 * plenty of space available to store the slightly larger, converted
@@ -649,7 +678,12 @@ static void rfc5993_hr_convert(struct mgcp_endpoint *endp, char *data, int *len)
 
 	struct rtp_hdr *rtp_hdr;
 
-	OSMO_ASSERT(*len >= sizeof(struct rtp_hdr));
+	if (*len < sizeof(struct rtp_hdr)) {
+		LOGPENDP(endp, DRTP, LOGL_ERROR, "AMR RTP packet too short (%d < %zu)\n",
+			 *len, sizeof(struct rtp_hdr));
+		return -EINVAL;
+	}
+
 	rtp_hdr = (struct rtp_hdr *)data;
 
 	if (*len == GSM_HR_BYTES + sizeof(struct rtp_hdr)) {
@@ -667,7 +701,9 @@ static void rfc5993_hr_convert(struct mgcp_endpoint *endp, char *data, int *len)
 		 * packet. This is not supported yet. */
 		LOGPENDP(endp, DRTP, LOGL_ERROR,
 			 "cannot figure out how to convert RTP packet\n");
+		return -ENOTSUP;
 	}
+	return 0;
 }
 
 /* For AMR RTP two framing modes are defined RFC3267. There is a bandwith
@@ -685,7 +721,11 @@ static int amr_oa_bwe_convert(struct mgcp_endpoint *endp, char *data, int *len,
 	unsigned int payload_len;
 	int rc;
 
-	OSMO_ASSERT(*len >= sizeof(struct rtp_hdr));
+	if (*len < sizeof(struct rtp_hdr)) {
+		LOGPENDP(endp, DRTP, LOGL_ERROR, "AMR RTP packet too short (%d < %zu)\n", *len, sizeof(struct rtp_hdr));
+		return -EINVAL;
+	}
+
 	rtp_hdr = (struct rtp_hdr *)data;
 
 	payload_len = *len - sizeof(struct rtp_hdr);
@@ -736,30 +776,33 @@ static bool amr_oa_bwe_convert_indicated(struct mgcp_rtp_codec *codec)
 
 
 /* Check if a given RTP with AMR payload for octet-aligned mode */
-static bool amr_oa_check(char *data, int len)
+static int amr_oa_check(char *data, int len)
 {
 	struct rtp_hdr *rtp_hdr;
 	unsigned int payload_len;
 
-	OSMO_ASSERT(len >= sizeof(struct rtp_hdr));
+	if (len < sizeof(struct rtp_hdr))
+		return -EINVAL;
+
 	rtp_hdr = (struct rtp_hdr *)data;
 
 	payload_len = len - sizeof(struct rtp_hdr);
+	if (payload_len < sizeof(struct amr_hdr))
+		return -EINVAL;
 
-	return osmo_amr_is_oa(rtp_hdr->data, payload_len);
+	return osmo_amr_is_oa(rtp_hdr->data, payload_len) ? 1 : 0;
 }
 
 /* Forward data to a debug tap. This is debug function that is intended for
  * debugging the voice traffic with tools like gstreamer */
-static void forward_data(int fd, struct mgcp_rtp_tap *tap, const char *buf,
-			 int len)
+static void forward_data(int fd, struct mgcp_rtp_tap *tap, struct msgb *msg)
 {
 	int rc;
 
 	if (!tap->enabled)
 		return;
 
-	rc = sendto(fd, buf, len, 0, (struct sockaddr *)&tap->forward,
+	rc = sendto(fd, msg->data, msg->len, 0, (struct sockaddr *)&tap->forward,
 		    sizeof(tap->forward));
 
 	if (rc < 0)
@@ -777,7 +820,7 @@ static void forward_data(int fd, struct mgcp_rtp_tap *tap, const char *buf,
  *  \param[in] conn_dst associated destination connection
  *  \returns 0 on success, -1 on ERROR */
 int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
-	      char *buf, int len, struct mgcp_conn_rtp *conn_src,
+	      struct msgb *msg, struct mgcp_conn_rtp *conn_src,
 	      struct mgcp_conn_rtp *conn_dst)
 {
 	/*! When no destination connection is available (e.g. when only one
@@ -789,6 +832,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 	struct mgcp_rtp_state *rtp_state;
 	char *dest_name;
 	int rc;
+	int len;
 
 	OSMO_ASSERT(conn_src);
 	OSMO_ASSERT(conn_dst);
@@ -812,7 +856,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 	 * should not occur if transcoding is consequently avoided. Until
 	 * we have transcoding support in osmo-mgw we can not resolve this. */
 	if (is_rtp) {
-		rc = mgcp_patch_pt(conn_src, conn_dst, buf, len);
+		rc = mgcp_patch_pt(conn_src, conn_dst, msg);
 		if (rc < 0) {
 			LOGPENDP(endp, DRTP, LOGL_DEBUG,
 				 "can not patch PT because no suitable egress codec was found.\n");
@@ -837,27 +881,37 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 	} else if (is_rtp) {
 		int cont;
 		int nbytes = 0;
-		int buflen = len;
+		int buflen = msg->len;
 		do {
 			/* Run transcoder */
 			cont = endp->cfg->rtp_processing_cb(endp, rtp_end,
-							    buf, &buflen,
+							    (char*)msg->data, &buflen,
 							    RTP_BUF_SIZE);
 			if (cont < 0)
 				break;
 
 			if (addr)
 				mgcp_patch_and_count(endp, rtp_state, rtp_end,
-						     addr, buf, buflen);
+						     addr, msg);
 
 			if (amr_oa_bwe_convert_indicated(conn_dst->end.codec)) {
-				amr_oa_bwe_convert(endp, buf, &buflen,
-						   conn_dst->end.codec->param.amr_octet_aligned);
+				rc = amr_oa_bwe_convert(endp, (char*)msg->data, &buflen,
+							conn_dst->end.codec->param.amr_octet_aligned);
+				if (rc < 0) {
+					LOGPENDP(endp, DRTP, LOGL_ERROR,
+						 "Error in AMR octet-aligned <-> bandwidth-efficient mode conversion\n");
+					break;
+				}
 			}
 			else if (rtp_end->rfc5993_hr_convert
 			    && strcmp(conn_src->end.codec->subtype_name,
-				      "GSM-HR-08") == 0)
-				rfc5993_hr_convert(endp, buf, &buflen);
+				      "GSM-HR-08") == 0) {
+				rc = rfc5993_hr_convert(endp, (char*)msg->data, &buflen);
+				if (rc < 0) {
+					LOGPENDP(endp, DRTP, LOGL_ERROR, "Error while converting to GSM-HR-08\n");
+					break;
+				}
+			}
 
 			LOGPENDP(endp, DRTP, LOGL_DEBUG,
 				 "process/send to %s %s "
@@ -868,8 +922,9 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 
 			/* Forward a copy of the RTP data to a debug ip/port */
 			forward_data(rtp_end->rtp.fd, &conn_src->tap_out,
-				     buf, buflen);
+				     msg);
 
+#if 0
 			/* FIXME: HACK HACK HACK. See OS#2459.
 			 * The ip.access nano3G needs the first RTP payload's first two bytes to read hex
 			 * 'e400', or it will reject the RAB assignment. It seems to not harm other femto
@@ -877,7 +932,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 			 */
 			if (!rtp_state->patched_first_rtp_payload
 			    && conn_src->conn->mode == MGCP_CONN_LOOPBACK) {
-				uint8_t *data = (uint8_t *) & buf[12];
+				uint8_t *data = msg->data + 12;
 				if (data[0] == 0xe0) {
 					data[0] = 0xe4;
 					data[1] = 0x00;
@@ -887,10 +942,13 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 						 " to fake an IuUP Initialization Ack\n");
 				}
 			}
+#endif
 
-			len = mgcp_udp_send(rtp_end->rtp.fd,
-					    &rtp_end->addr,
-					    rtp_end->rtp_port, buf, buflen);
+			if (conn_dst->iuup)
+				len = osmo_iuup_cn_tx_payload(conn_dst->iuup, msg);
+			else
+				len = mgcp_udp_send(rtp_end->rtp.fd, &rtp_end->addr, rtp_end->rtp_port,
+						    (char*)msg->data, msg->len);
 
 			if (len <= 0)
 				return len;
@@ -911,7 +969,7 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 
 		len = mgcp_udp_send(rtp_end->rtcp.fd,
 				    &rtp_end->addr,
-				    rtp_end->rtcp_port, buf, len);
+				    rtp_end->rtcp_port, (char*)msg->data, msg->len);
 
 		rate_ctr_inc(&conn_dst->rate_ctr_group->ctr[RTP_PACKETS_TX_CTR]);
 		rate_ctr_add(&conn_dst->rate_ctr_group->ctr[RTP_OCTETS_TX_CTR], len);
@@ -922,45 +980,6 @@ int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
 	return 0;
 }
 
-/* Helper function for mgcp_recv(),
-   Receive one RTP Packet + Originating address from file descriptor */
-static int receive_from(struct mgcp_endpoint *endp, int fd,
-			struct sockaddr_in *addr, char *buf, int bufsize)
-{
-	int rc;
-	socklen_t slen = sizeof(*addr);
-	struct sockaddr_in addr_sink;
-	char buf_sink[RTP_BUF_SIZE];
-	bool tossed = false;
-
-	if (!addr)
-		addr = &addr_sink;
-	if (!buf) {
-		tossed = true;
-		buf = buf_sink;
-		bufsize = sizeof(buf_sink);
-	}
-
-	rc = recvfrom(fd, buf, bufsize, 0, (struct sockaddr *)addr, &slen);
-
-	LOGPENDP(endp, DRTP, LOGL_DEBUG,
-	     "receiving %u bytes length packet from %s:%u ...\n",
-	     rc, inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
-
-	if (rc < 0) {
-		LOGPENDP(endp, DRTP, LOGL_ERROR,
-			 "failed to receive packet, errno: %d/%s\n",
-			 errno, strerror(errno));
-		return -1;
-	}
-
-	if (tossed) {
-		LOGPENDP(endp, DRTP, LOGL_ERROR, "packet tossed\n");
-	}
-
-	return rc;
-}
-
 /* Check if the origin (addr) matches the address/port data of the RTP
  * connections. */
 static int check_rtp_origin(struct mgcp_conn_rtp *conn,
@@ -1053,7 +1072,7 @@ static int check_rtp_destin(struct mgcp_conn_rtp *conn)
 
 /* Do some basic checks to make sure that the RTCP packets we are going to
  * process are not complete garbage */
-static int check_rtcp(char *buf, unsigned int buf_size)
+static int check_rtcp(struct mgcp_conn_rtp *conn_src, struct msgb *msg)
 {
 	struct rtcp_hdr *hdr;
 	unsigned int len;
@@ -1061,33 +1080,45 @@ static int check_rtcp(char *buf, unsigned int buf_size)
 
 	/* RTPC packets that are just a header without data do not make
 	 * any sense. */
-	if (buf_size < sizeof(struct rtcp_hdr))
+	if (msg->len < sizeof(struct rtcp_hdr)) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTCP packet too short (%u < %zu)\n",
+			     msg->len, sizeof(struct rtcp_hdr));
 		return -EINVAL;
+	}
 
 	/* Make sure that the length of the received packet does not exceed
 	 * the available buffer size */
-	hdr = (struct rtcp_hdr *)buf;
+	hdr = (struct rtcp_hdr *)msg->data;
 	len = (osmo_ntohs(hdr->length) + 1) * 4;
-	if (len > buf_size)
+	if (len > msg->len) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTCP header length exceeds packet size (%u > %u)\n",
+			     len, msg->len);
 		return -EINVAL;
+	}
 
 	/* Make sure we accept only packets that have a proper packet type set
 	 * See also: http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml */
 	type = hdr->type;
-	if ((type < 192 || type > 195) && (type < 200 || type > 213))
+	if ((type < 192 || type > 195) && (type < 200 || type > 213)) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTCP header: invalid type: %u\n", type);
 		return -EINVAL;
+	}
 
 	return 0;
 }
 
 /* Do some basic checks to make sure that the RTP packets we are going to
  * process are not complete garbage */
-static int check_rtp(char *buf, unsigned int buf_size)
+static int check_rtp(struct mgcp_conn_rtp *conn_src, struct msgb *msg)
 {
-	/* RTP packets that are just a header without data do not make
-	 * any sense. */
-	if (buf_size < sizeof(struct rtp_hdr))
-		return -EINVAL;
+	size_t min_size = sizeof(struct rtp_hdr);
+	if (conn_src->iuup)
+		min_size += sizeof(struct osmo_iuup_hdr_data);
+	if (msg->len < min_size) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "RTP packet too short (%u < %zu)\n",
+			     msg->len, min_size);
+		return -1;
+	}
 
 	/* FIXME: Add more checks, the reason why we do not check more than
 	 * the length is because we currently handle IUUP packets as RTP
@@ -1098,86 +1129,14 @@ static int check_rtp(char *buf, unsigned int buf_size)
 	return 0;
 }
 
-/* Receive RTP data from a specified source connection and dispatch it to a
- * destination connection. */
-static int mgcp_recv(int *proto, struct sockaddr_in *addr, char *buf,
-		     unsigned int buf_size, struct osmo_fd *fd)
-{
-	struct mgcp_endpoint *endp;
-	struct mgcp_conn_rtp *conn;
-	struct mgcp_trunk_config *tcfg;
-	int rc;
-
-	conn = (struct mgcp_conn_rtp*) fd->data;
-	endp = conn->conn->endp;
-	tcfg = endp->tcfg;
-
-	LOGPCONN(conn->conn, DRTP, LOGL_DEBUG, "receiving RTP/RTCP packet...\n");
-
-	rc = receive_from(endp, fd->fd, addr, buf, buf_size);
-	if (rc <= 0)
-		return -1;
-
-	/* FIXME: The way how we detect the protocol looks odd. We should look
-	 * into the packet header. Also we should introduce a packet type
-	 * MGCP_PROTO_IUUP because currently we handle IUUP packets like RTP
-	 * packets which is problematic. */
-	*proto = fd == &conn->end.rtp ? MGCP_PROTO_RTP : MGCP_PROTO_RTCP;
-
-	if (*proto == MGCP_PROTO_RTP) {
-		if (check_rtp(buf, rc) < 0) {
-			LOGPCONN(conn->conn, DRTP, LOGL_ERROR,
-				 "invalid RTP packet received -- packet tossed\n");
-			return -1;
-		}
-	} else if (*proto == MGCP_PROTO_RTCP) {
-		if (check_rtcp(buf, rc) < 0) {
-			LOGPCONN(conn->conn, DRTP, LOGL_ERROR,
-				 "invalid RTCP packet received -- packet tossed\n");
-			return -1;
-		}
-	}
-
-	LOGPCONN(conn->conn, DRTP, LOGL_DEBUG, "");
-	LOGPC(DRTP, LOGL_DEBUG, "receiving from %s %s %d\n",
-	      conn->conn->name, inet_ntoa(addr->sin_addr),
-	      ntohs(addr->sin_port));
-	LOGPENDP(endp, DRTP, LOGL_DEBUG, "conn:%s\n", mgcp_conn_dump(conn->conn));
-
-	/* Check if the origin of the RTP packet seems plausible */
-	if (tcfg->rtp_accept_all == 0) {
-		if (check_rtp_origin(conn, addr) != 0)
-			return -1;
-	}
-
-	/* Filter out dummy message */
-	if (rc == 1 && buf[0] == MGCP_DUMMY_LOAD) {
-		LOGPCONN(conn->conn, DRTP, LOGL_NOTICE,
-			 "dummy message received\n");
-		LOGPCONN(conn->conn, DRTP, LOGL_ERROR,
-			 "packet tossed\n");
-		return 0;
-	}
-
-	/* Increment RX statistics */
-	rate_ctr_inc(&conn->rate_ctr_group->ctr[RTP_PACKETS_RX_CTR]);
-	rate_ctr_add(&conn->rate_ctr_group->ctr[RTP_OCTETS_RX_CTR], rc);
-
-	/* Forward a copy of the RTP data to a debug ip/port */
-	forward_data(fd->fd, &conn->tap_in, buf, rc);
-
-	return rc;
-}
-
 /* Send RTP data. Possible options are standard RTP packet
  * transmission or trsmission via an osmux connection */
-static int mgcp_send_rtp(int proto, struct sockaddr_in *addr, char *buf,
-			 unsigned int buf_size,
-			 struct mgcp_conn_rtp *conn_src,
-			 struct mgcp_conn_rtp *conn_dst)
+static int mgcp_send_rtp(struct mgcp_conn_rtp *conn_dst, struct msgb *msg)
 {
-	struct mgcp_endpoint *endp;
-	endp = conn_src->conn->endp;
+	enum rtp_proto proto = OSMO_RTP_MSG_CTX(msg)->proto;
+	struct mgcp_conn_rtp *conn_src = OSMO_RTP_MSG_CTX(msg)->conn_src;
+	struct sockaddr_in *from_addr = OSMO_RTP_MSG_CTX(msg)->from_addr;
+	struct mgcp_endpoint *endp = conn_src->conn->endp;
 
 	LOGPENDP(endp, DRTP, LOGL_DEBUG, "destin conn:%s\n",
 		 mgcp_conn_dump(conn_dst->conn));
@@ -1196,13 +1155,13 @@ static int mgcp_send_rtp(int proto, struct sockaddr_in *addr, char *buf,
 			 "endpoint type is MGCP_RTP_DEFAULT, "
 			 "using mgcp_send() to forward data directly\n");
 		return mgcp_send(endp, proto == MGCP_PROTO_RTP,
-				 addr, buf, buf_size, conn_src, conn_dst);
+				 from_addr, msg, conn_src, conn_dst);
 	case MGCP_OSMUX_BSC_NAT:
 	case MGCP_OSMUX_BSC:
 		LOGPENDP(endp, DRTP, LOGL_DEBUG,
 			 "endpoint type is MGCP_OSMUX_BSC_NAT, "
 			 "using osmux_xfrm_to_osmux() to forward data through OSMUX\n");
-		return osmux_xfrm_to_osmux(buf, buf_size, conn_dst);
+		return osmux_xfrm_to_osmux((char*)msg->data, msg->len, conn_dst);
 	}
 
 	/* If the data has not been handled/forwarded until here, it will
@@ -1220,10 +1179,12 @@ static int mgcp_send_rtp(int proto, struct sockaddr_in *addr, char *buf,
  *  \param[in] buf_size size data length of buf
  *  \param[in] conn originating connection
  *  \returns 0 on success, -1 on ERROR */
-int mgcp_dispatch_rtp_bridge_cb(int proto, struct sockaddr_in *addr, char *buf,
-				unsigned int buf_size, struct mgcp_conn *conn)
+int mgcp_dispatch_rtp_bridge_cb(struct msgb *msg)
 {
+	struct mgcp_conn_rtp *conn_src = OSMO_RTP_MSG_CTX(msg)->conn_src;
+	struct mgcp_conn *conn = conn_src->conn;
 	struct mgcp_conn *conn_dst;
+	struct sockaddr_in *from_addr = OSMO_RTP_MSG_CTX(msg)->from_addr;
 
 	/*! NOTE: This callback function implements the endpoint specific
 	 *  dispatch bahviour of an rtp bridge/proxy endpoint. It is assumed
@@ -1242,11 +1203,10 @@ int mgcp_dispatch_rtp_bridge_cb(int proto, struct sockaddr_in *addr, char *buf,
 		 * address data from the UDP packet header to patch the
 		 * outgoing address in connection on the fly */
 		if (conn->u.rtp.end.rtp_port == 0) {
-			conn->u.rtp.end.addr = addr->sin_addr;
-			conn->u.rtp.end.rtp_port = addr->sin_port;
+			conn->u.rtp.end.addr = from_addr->sin_addr;
+			conn->u.rtp.end.rtp_port = from_addr->sin_port;
 		}
-		return mgcp_send_rtp(proto, addr, buf,
-				     buf_size, &conn->u.rtp, &conn->u.rtp);
+		return mgcp_send_rtp(conn_src, msg);
 	}
 
 	/* Find a destination connection. */
@@ -1278,9 +1238,7 @@ int mgcp_dispatch_rtp_bridge_cb(int proto, struct sockaddr_in *addr, char *buf,
 	}
 
 	/* Dispatch RTP packet to destination RTP connection */
-	return mgcp_send_rtp(proto, addr, buf,
-			     buf_size, &conn->u.rtp, &conn_dst->u.rtp);
-
+	return mgcp_send_rtp(&conn_dst->u.rtp, msg);
 }
 
 /*! cleanup an endpoint when a connection on an RTP bridge endpoint is removed.
@@ -1302,6 +1260,76 @@ void mgcp_cleanup_rtp_bridge_cb(struct mgcp_endpoint *endp, struct mgcp_conn *co
 	}
 }
 
+static bool is_dummy_msg(enum rtp_proto proto, struct msgb *msg)
+{
+	return msg->len == 1 && msg->data[0] == MGCP_DUMMY_LOAD;
+}
+
+struct pdu_ctx {
+	struct sockaddr_in *from_addr;
+	struct mgcp_conn_rtp *conn_src;
+};
+
+/* IuUP CN node has stripped an IuUP header and forwards RTP data to distribute to the peers. */
+int iuup_rx_payload(struct msgb *msg, void *node_priv)
+{
+	struct mgcp_conn_rtp *conn_src = OSMO_RTP_MSG_CTX(msg)->conn_src;
+	LOG_CONN_RTP(conn_src, LOGL_DEBUG, "iuup_rx_payload(%u bytes)\n", msg->len);
+	return rx_rtp(msg);
+}
+
+/* IuUP CN node has composed a message that contains an IuUP header and asks us to send to the IuUP peer.
+ */
+int iuup_tx_msg(struct msgb *msg, void *node_priv)
+{
+	const struct in_addr zero_addr = {};
+	struct mgcp_conn_rtp *conn_src = OSMO_RTP_MSG_CTX(msg)->conn_src;
+	struct mgcp_conn_rtp *conn_dst = node_priv;
+	struct sockaddr_in *from_addr = OSMO_RTP_MSG_CTX(msg)->from_addr;
+	struct mgcp_rtp_end *rtp_end = &conn_dst->end;
+	struct in_addr to_addr = rtp_end->addr;
+	uint16_t to_port = rtp_end->rtp_port;
+
+	if (conn_src == conn_dst
+	    && !memcmp(&zero_addr, &to_addr, sizeof(zero_addr)) && !to_port) {
+		LOG_CONN_RTP(conn_dst, LOGL_DEBUG, "iuup_tx_msg(): direct IuUP reply\n");
+		/* IuUP wants to send a message back to the same peer that sent an RTP package, but there
+		 * is no address configured for that peer yet. It is probably an IuUP Initialization ACK
+		 * reply. Use the sender address to send the reply.
+		 *
+		 * During 3G RAB Assignment, a 3G cell might first probe the MGW and expect an IuUP
+		 * Initialization ACK before it replies to the MSC with a successful RAB Assignment; only
+		 * after that reply does MSC officially know which RTP address+port the 3G cell wants to
+		 * use and can tell this MGW about it, so this "loopback" is, for some 3G cells, the only
+		 * chance we have to get a successful RAB Assignment done (particularly the nano3G does
+		 * this). */
+		to_addr = from_addr->sin_addr;
+		to_port = from_addr->sin_port;
+	}
+
+	LOG_CONN_RTP(conn_dst, LOGL_DEBUG, "iuup_tx_msg(%u bytes) to %s:%u\n", msg->len,
+		     inet_ntoa(to_addr), ntohs(to_port));
+
+	return mgcp_udp_send(rtp_end->rtp.fd, &to_addr, to_port, (char*)msg->data, msg->len);
+}
+
+static void iuup_init(struct mgcp_conn_rtp *conn_src)
+{
+	struct osmo_iuup_cn_cfg cfg = {
+		.node_priv = conn_src,
+		.rx_payload = iuup_rx_payload,
+		.tx_msg = iuup_tx_msg,
+	};
+
+	if (conn_src->iuup) {
+		LOG_CONN_RTP(conn_src, LOGL_NOTICE, "Rx IuUP init, but already initialized. Ignoring.\n");
+		return;
+	}
+
+	conn_src->iuup = osmo_iuup_cn_init(conn_src->conn, &cfg, "endp_%d_conn_%s",
+					   ENDPOINT_NUMBER(conn_src->conn->endp), conn_src->conn->id);
+}
+
 /* Handle incoming RTP data from NET */
 static int rtp_data_net(struct osmo_fd *fd, unsigned int what)
 {
@@ -1315,23 +1343,88 @@ static int rtp_data_net(struct osmo_fd *fd, unsigned int what)
 	struct mgcp_conn_rtp *conn_src;
 	struct mgcp_endpoint *endp;
 	struct sockaddr_in addr;
-
-	char buf[RTP_BUF_SIZE];
-	int proto;
-	int len;
+	socklen_t slen = sizeof(addr);
+	int ret;
+	enum rtp_proto proto;
+	struct osmo_rtp_msg_ctx mc;
+	struct msgb *msg = msgb_alloc_headroom(RTP_BUF_SIZE + OSMO_IUUP_HEADROOM,
+					       OSMO_IUUP_HEADROOM, "RTP-rx");
+	int rc;
 
 	conn_src = (struct mgcp_conn_rtp *)fd->data;
 	OSMO_ASSERT(conn_src);
 	endp = conn_src->conn->endp;
 	OSMO_ASSERT(endp);
 
-	LOGPENDP(endp, DRTP, LOGL_DEBUG, "source conn:%s\n",
-		 mgcp_conn_dump(conn_src->conn));
+	proto = (fd == &conn_src->end.rtp)? MGCP_PROTO_RTP : MGCP_PROTO_RTCP;
 
-	/* Receive packet */
-	len = mgcp_recv(&proto, &addr, buf, sizeof(buf), fd);
-	if (len < 0)
-		return -1;
+	ret = recvfrom(fd->fd, msg->data, msg->data_len, 0, (struct sockaddr *)&addr, &slen);
+
+	if (ret <= 0) {
+		LOG_CONN_RTP(conn_src, LOGL_ERROR, "recvfrom error: %s\n", strerror(errno));
+		rc = -1;
+		goto out;
+	}
+
+	msgb_put(msg, ret);
+
+	LOG_CONN_RTP(conn_src, LOGL_DEBUG, "%s: rx %u bytes from %s:%u\n",
+		     proto == MGCP_PROTO_RTP ? "RTP" : "RTPC",
+		     msg->len, inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
+
+	if ((proto == MGCP_PROTO_RTP && check_rtp(conn_src, msg))
+	    || (proto == MGCP_PROTO_RTCP && check_rtcp(conn_src, msg))) {
+		/* Logging happened in the two check_ functions */
+		rc = -1;
+		goto out;
+	}
+
+	if (is_dummy_msg(proto, msg)) {
+		LOG_CONN_RTP(conn_src, LOGL_DEBUG, "rx dummy packet (dropped)\n");
+		rc = 0;
+		goto out;
+	}
+
+	mc = (struct osmo_rtp_msg_ctx){
+		.proto = proto,
+		.conn_src = conn_src,
+		.from_addr = &addr,
+	};
+	OSMO_RTP_MSG_CTX(msg) = &mc;
+	LOG_CONN_RTP(conn_src, LOGL_DEBUG, "msg ctx: %d %p %s\n",
+		     OSMO_RTP_MSG_CTX(msg)->proto,
+		     OSMO_RTP_MSG_CTX(msg)->conn_src,
+		     osmo_hexdump((void*)OSMO_RTP_MSG_CTX(msg)->from_addr, sizeof(struct sockaddr_in)));
+
+	/* Increment RX statistics */
+	rate_ctr_inc(&conn_src->rate_ctr_group->ctr[RTP_PACKETS_RX_CTR]);
+	rate_ctr_add(&conn_src->rate_ctr_group->ctr[RTP_OCTETS_RX_CTR], msg->len);
+	/* FIXME: count RTP and RTCP separately, also count IuUP payload-less separately */
+
+	/* Forward a copy of the RTP data to a debug ip/port */
+	forward_data(fd->fd, &conn_src->tap_in, msg);
+
+	if (proto == MGCP_PROTO_RTP && osmo_iuup_is_init(msg))
+		iuup_init(conn_src);
+
+	if (conn_src->iuup && proto == MGCP_PROTO_RTP)
+		rc = osmo_iuup_cn_rx_pdu(conn_src->iuup, msg);
+	else
+		rc = rx_rtp(msg);
+
+out:
+	msgb_free(msg);
+	return rc;
+}
+
+static int rx_rtp(struct msgb *msg)
+{
+	struct mgcp_conn_rtp *conn_src = OSMO_RTP_MSG_CTX(msg)->conn_src;
+	struct sockaddr_in *from_addr = OSMO_RTP_MSG_CTX(msg)->from_addr;
+	struct mgcp_conn *conn = conn_src->conn;
+	struct mgcp_trunk_config *tcfg = conn->endp->tcfg;
+
+	LOG_CONN_RTP(conn_src, LOGL_DEBUG, "rx_rtp(%u bytes)\n", msg->len);
 
 	mgcp_conn_watchdog_kick(conn_src->conn);
 
@@ -1340,14 +1433,20 @@ static int rtp_data_net(struct osmo_fd *fd, unsigned int what)
 	 * define, then we check if the incoming payload matches that
 	 * expectation. */
 	if (amr_oa_bwe_convert_indicated(conn_src->end.codec)) {
-		if (amr_oa_check(buf, len) != conn_src->end.codec->param.amr_octet_aligned)
+		int oa = amr_oa_check((char*)msg->data, msg->len);
+		if (oa < 0)
+			return -1;
+		if (((bool)oa) != conn_src->end.codec->param.amr_octet_aligned)
 			return -1;
 	}
 
+	/* Check if the origin of the RTP packet seems plausible */
+	if (!tcfg->rtp_accept_all && check_rtp_origin(conn_src, from_addr))
+		return -1;
+
 	/* Execute endpoint specific implementation that handles the
 	 * dispatching of the RTP data */
-	return endp->type->dispatch_rtp_cb(proto, &addr, buf, len,
-					   conn_src->conn);
+	return conn->endp->type->dispatch_rtp_cb(msg);
 }
 
 /*! set IP Type of Service parameter.

src/libosmo-mgcp/mgcp_osmux.c

@@ -234,13 +234,8 @@ static void scheduled_from_osmux_tx_rtp_cb(struct msgb *msg, void *data)
 {
 	struct mgcp_conn_rtp *conn = data;
 	struct mgcp_endpoint *endp = conn->conn->endp;
-	struct sockaddr_in addr = {
-		.sin_addr = conn->end.addr,
-		.sin_port = conn->end.rtp_port,
-	}; /* FIXME: not set/used in cb */
 
-
-	endp->type->dispatch_rtp_cb(MGCP_PROTO_RTP, &addr, (char *)msg->data, msg->len, conn->conn);
+	endp->type->dispatch_rtp_cb(msg);
 	msgb_free(msg);
 }
 

src/osmo-mgw/mgw_main.c

@@ -244,6 +244,12 @@ static const struct log_info_cat log_categories[] = {
 		  .color = "\033[1;30m",
 		  .enabled = 1,.loglevel = LOGL_NOTICE,
 		  },
+	[DIUUP] = {
+		  .name = "DIUUP",
+		  .description = "IuUP within RTP stream handling",
+		  .color = "\033[1;31m",
+		  .enabled = 1,.loglevel = LOGL_NOTICE,
+		  },
 };
 
 const struct log_info log_info = {

tests/Makefile.am

@@ -1,6 +1,7 @@
 SUBDIRS = \
 	mgcp_client \
 	mgcp \
+	iuup \
 	$(NULL)
 
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.

tests/iuup/Makefile.am

@@ -0,0 +1,45 @@
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	-I$(top_srcdir) \
+	$(NULL)
+
+AM_CFLAGS = \
+	-Wall \
+	-ggdb3 \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOVTY_CFLAGS) \
+	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMONETIF_CFLAGS) \
+	$(COVERAGE_CFLAGS) \
+	$(NULL)
+
+AM_LDFLAGS = \
+	$(COVERAGE_LDFLAGS) \
+	$(NULL)
+
+EXTRA_DIST = \
+	iuup_test.ok \
+	iuup_test.err \
+	$(NULL)
+
+noinst_PROGRAMS = \
+	iuup_test \
+	$(NULL)
+
+iuup_test_SOURCES = \
+	iuup_test.c \
+	$(NULL)
+
+iuup_test_LDADD = \
+	$(top_builddir)/src/libosmo-mgcp/libosmo-mgcp.a \
+	$(LIBOSMOCORE_LIBS) \
+	$(LIBOSMOVTY_LIBS) \
+	$(LIBOSMOGSM_LIBS) \
+	$(LIBRARY_DL) \
+	$(LIBOSMONETIF_LIBS) \
+	-lm  \
+	$(NULL)
+
+update_exp:
+	$(builddir)/iuup_test >$(srcdir)/iuup_test.ok 2>$(srcdir)/iuup_test.err

tests/iuup/iuup_test.c

@@ -0,0 +1,156 @@
+#include <stdint.h>
+#include <string.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/application.h>
+#include <osmocom/core/logging.h>
+
+#include <osmocom/mgcp/iuup_cn_node.h>
+#include <osmocom/mgcp/iuup_protocol.h>
+
+void *ctx = NULL;
+
+static const char *dump(struct msgb *msg)
+{
+	return osmo_hexdump_nospc(msg->data, msg->len);
+}
+
+struct msgb *msgb_from_hex(const char *label, const char *hex)
+{
+	struct msgb *msg = msgb_alloc_headroom(4096 + OSMO_IUUP_HEADROOM,
+					       OSMO_IUUP_HEADROOM, label);
+	unsigned char *rc;
+	msg->l2h = msg->data;
+	rc = msgb_put(msg, osmo_hexparse(hex, msg->data, msgb_tailroom(msg)));
+	OSMO_ASSERT(rc == msg->l2h);
+	return msg;
+}
+
+const char *expect_rx_payload = NULL;
+int rx_payload(struct msgb *msg, void *node_priv)
+{
+	printf("rx_payload() invoked by iuup_cn!\n");
+	printf("        [IuUP] -RTP->\n");
+	printf("%s\n", dump(msg));
+	printf("node_priv=%p\n", node_priv);
+	if (!expect_rx_payload) {
+		printf("ERROR: did not expect rx_payload()\n");
+		exit(-1);
+	} else if (strcmp(expect_rx_payload, dump(msg))) {
+		printf("ERROR: mismatches expected msg %s\n", expect_rx_payload);
+		exit(-1);
+	} else
+		printf("ok: matches expected msg\n");
+	expect_rx_payload = NULL;
+	return 0;
+}
+
+const char *expect_tx_msg = NULL;
+int tx_msg(struct msgb *msg, void *node_priv)
+{
+	printf("tx_msg() invoked by iuup_cn!\n");
+	printf(" <-PDU- [IuUP]\n");
+	printf("%s\n", dump(msg));
+	printf("node_priv=%p\n", node_priv);
+	if (!expect_tx_msg) {
+		printf("ERROR: did not expect tx_msg()\n");
+		exit(-1);
+	} else if (strcmp(expect_tx_msg, dump(msg))) {
+		printf("ERROR: mismatches expected msg %s\n", expect_tx_msg);
+		exit(-1);
+	} else
+		printf("ok: matches expected msg\n");
+	expect_tx_msg = NULL;
+	return 0;
+}
+
+static int rx_pdu(struct osmo_iuup_cn *cn, struct msgb *msg)
+{
+	int rc;
+	printf(" -PDU-> [IuUP]\n");
+	printf("%s\n", dump(msg));
+	rc = osmo_iuup_cn_rx_pdu(cn, msg);
+	printf("rc=%d\n", rc);
+	return rc;
+}
+
+static int tx_payload(struct osmo_iuup_cn *cn, struct msgb *msg)
+{
+	int rc;
+	printf("        [IuUP] <-RTP-\n");
+	printf("%s\n", dump(msg));
+	rc = osmo_iuup_cn_tx_payload(cn, msg);
+	printf("rc=%d\n", rc);
+	return rc;
+}
+
+void test_cn_session()
+{
+	void *node_priv = (void*)0x2342;
+
+	struct osmo_iuup_cn_cfg cfg = {
+		.node_priv = node_priv,
+		.rx_payload = rx_payload,
+		.tx_msg = tx_msg,
+	};
+
+	struct osmo_iuup_cn *cn = osmo_iuup_cn_init(ctx, &cfg, __func__);
+	OSMO_ASSERT(cn);
+
+	printf("\nSend IuUP Initialization. Expecting direct tx_msg() of the Initialization Ack\n");
+	expect_tx_msg = "8060dc5219495e3f00010111" /* RTP header */
+			"e4002400"; /* IuUP Init Ack */
+	rx_pdu(cn,
+	       msgb_from_hex("IuUP-Init",
+			     "8060dc5219495e3f00010111" /* <- RTP header */
+			     "e000df99" /* <- IuUP header */
+			     "160051673c01270000820000001710000100" /* IuUP params */));
+
+#define RTP_HEADER "8060944c6256042c00010102"
+#define IUUP_HEADER "0100e2b3"
+#define RTP_PAYLOAD "6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0"
+	printf("\nReceive payload encapsulated in IuUP. Expecting rx_payload() of just RTP packet\n");
+	printf("i.e. should strip away " IUUP_HEADER "\n");
+	expect_rx_payload = RTP_HEADER "f03c" RTP_PAYLOAD;
+	rx_pdu(cn,
+	       msgb_from_hex("IuUP-Data",
+			     RTP_HEADER IUUP_HEADER RTP_PAYLOAD));
+
+	printf("\nTransmit RTP. Expecting tx_msg() with inserted IuUP header\n");
+	expect_tx_msg = RTP_HEADER "000002b3" RTP_PAYLOAD;
+	tx_payload(cn,
+		   msgb_from_hex("RTP data", RTP_HEADER "f03c" RTP_PAYLOAD));
+
+	printf("\nMore RTP, each time the Frame Nr advances, causing a new header CRC.\n");
+	expect_tx_msg = RTP_HEADER "0100e2b3" RTP_PAYLOAD;
+	tx_payload(cn,
+		   msgb_from_hex("RTP data", RTP_HEADER "f03c" RTP_PAYLOAD));
+	expect_tx_msg = RTP_HEADER "02007eb3" RTP_PAYLOAD;
+	tx_payload(cn,
+		   msgb_from_hex("RTP data", RTP_HEADER "f03c" RTP_PAYLOAD));
+	expect_tx_msg = RTP_HEADER "03009eb3" RTP_PAYLOAD;
+	tx_payload(cn,
+		   msgb_from_hex("RTP data", RTP_HEADER "f03c" RTP_PAYLOAD));
+
+	printf("All done.\n");
+}
+
+static const struct log_info_cat log_categories[] = {
+};
+
+const struct log_info log_info = {
+	.cat = log_categories,
+	.num_cat = ARRAY_SIZE(log_categories),
+};
+
+int main(void)
+{
+	ctx = talloc_named_const(NULL, 0, __FILE__);
+	void *msgb_ctx = msgb_talloc_ctx_init(ctx, 0);
+	osmo_init_logging2(ctx, &log_info);
+
+	test_cn_session();
+
+	talloc_free(msgb_ctx);
+	return 0;
+}

tests/iuup/iuup_test.ok

@@ -0,0 +1,58 @@
+
+Send IuUP Initialization. Expecting direct tx_msg() of the Initialization Ack
+ -PDU-> [IuUP]
+8060dc5219495e3f00010111e000df99160051673c01270000820000001710000100
+tx_msg() invoked by iuup_cn!
+ <-PDU- [IuUP]
+8060dc5219495e3f00010111e4002400
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+
+Receive payload encapsulated in IuUP. Expecting rx_payload() of just RTP packet
+i.e. should strip away 0100e2b3
+ -PDU-> [IuUP]
+8060944c6256042c000101020100e2b36cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+rx_payload() invoked by iuup_cn!
+        [IuUP] -RTP->
+8060944c6256042c00010102f03c6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+
+Transmit RTP. Expecting tx_msg() with inserted IuUP header
+        [IuUP] <-RTP-
+8060944c6256042c00010102f03c6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+tx_msg() invoked by iuup_cn!
+ <-PDU- [IuUP]
+8060944c6256042c00010102000002b36cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+
+More RTP, each time the Frame Nr advances, causing a new header CRC.
+        [IuUP] <-RTP-
+8060944c6256042c00010102f03c6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+tx_msg() invoked by iuup_cn!
+ <-PDU- [IuUP]
+8060944c6256042c000101020100e2b36cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+        [IuUP] <-RTP-
+8060944c6256042c00010102f03c6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+tx_msg() invoked by iuup_cn!
+ <-PDU- [IuUP]
+8060944c6256042c0001010202007eb36cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+        [IuUP] <-RTP-
+8060944c6256042c00010102f03c6cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+tx_msg() invoked by iuup_cn!
+ <-PDU- [IuUP]
+8060944c6256042c0001010203009eb36cfb23bc46d18180c3e5ffe040045600005a7d35b625b80005fff03214ced0
+node_priv=0x2342
+ok: matches expected msg
+rc=0
+All done.

tests/mgcp/mgcp_test.c

@@ -28,6 +28,7 @@
 #include <osmocom/mgcp/mgcp_endp.h>
 #include <osmocom/mgcp/mgcp_sdp.h>
 #include <osmocom/mgcp/mgcp_codec.h>
+#include <osmocom/mgcp/mgcp_internal.h>
 
 #include <osmocom/core/application.h>
 #include <osmocom/core/talloc.h>
@@ -1237,7 +1238,7 @@ struct rtp_packet_info test_rtp_packets1[] = {
 void mgcp_patch_and_count(struct mgcp_endpoint *endp,
 			  struct mgcp_rtp_state *state,
 			  struct mgcp_rtp_end *rtp_end,
-			  struct sockaddr_in *addr, char *data, int len);
+			  struct sockaddr_in *addr, struct msgb *msg);
 
 static void test_packet_error_detection(int patch_ssrc, int patch_ts)
 {
@@ -1249,7 +1250,6 @@ static void test_packet_error_detection(int patch_ssrc, int patch_ts)
 	struct mgcp_rtp_state state;
 	struct mgcp_rtp_end *rtp;
 	struct sockaddr_in addr = { 0 };
-	char buffer[4096];
 	uint32_t last_ssrc = 0;
 	uint32_t last_timestamp = 0;
 	uint32_t last_seqno = 0;
@@ -1297,16 +1297,17 @@ static void test_packet_error_detection(int patch_ssrc, int patch_ts)
 
 	for (i = 0; i < ARRAY_SIZE(test_rtp_packets1); ++i) {
 		struct rtp_packet_info *info = test_rtp_packets1 + i;
+		struct msgb *msg = msgb_alloc(4096, __func__);
 
 		force_monotonic_time_us = round(1000000.0 * info->txtime);
 
-		OSMO_ASSERT(info->len <= sizeof(buffer));
+		OSMO_ASSERT(info->len <= msgb_tailroom(msg));
 		OSMO_ASSERT(info->len >= 0);
-		memmove(buffer, info->data, info->len);
+		msg->l3h = msgb_put(msg, info->len);
+		memcpy((char*)msgb_l3(msg), info->data, info->len);
 		mgcp_rtp_end_config(&endp, 1, rtp);
 
-		mgcp_patch_and_count(&endp, &state, rtp, &addr,
-				     buffer, info->len);
+		mgcp_patch_and_count(&endp, &state, rtp, &addr, msg);
 
 		if (state.out_stream.ssrc != last_ssrc) {
 			printf("Output SSRC changed to %08x\n",
@@ -1333,6 +1334,8 @@ static void test_packet_error_detection(int patch_ssrc, int patch_ts)
 		last_out_ts_err_cnt = state.out_stream.err_ts_ctr->current;
 		last_timestamp = state.out_stream.last_timestamp;
 		last_seqno = state.out_stream.last_seq;
+
+		msgb_free(msg);
 	}
 
 	force_monotonic_time_us = -1;
@@ -1711,98 +1714,335 @@ static void test_check_local_cx_options(void *ctx)
 	OSMO_ASSERT(check_local_cx_options(ctx, ",,,") == -1);
 }
 
-static void test_mgcp_codec_pt_translate_pars(struct mgcp_rtp_codec *c)
-{
-	c->rate = 8000;
-	c->channels = 1;
-	c->frame_duration_num = 23;
-	c->frame_duration_den = 42;
-}
+static const struct mgcp_codec_param amr_param_octet_aligned_true = {
+	.amr_octet_aligned_present = true,
+	.amr_octet_aligned = true,
+};
+
+static const struct mgcp_codec_param amr_param_octet_aligned_false = {
+	.amr_octet_aligned_present = true,
+	.amr_octet_aligned = false,
+};
+
+static const struct mgcp_codec_param amr_param_octet_aligned_unset = {
+	.amr_octet_aligned_present = false,
+};
+
+struct testcase_mgcp_codec_pt_translate_codec {
+	int payload_type;
+	const char *audio_name;
+	const struct mgcp_codec_param *param;
+	int expect_rc;
+};
+
+struct testcase_mgcp_codec_pt_translate_expect {
+	bool end;
+	int payload_type_map[2];
+};
+
+struct testcase_mgcp_codec_pt_translate {
+	const char *descr;
+	/* two conns on an endpoint, each with N configured codecs */
+	struct testcase_mgcp_codec_pt_translate_codec codecs[2][10];
+	struct testcase_mgcp_codec_pt_translate_expect expect[32];
+};
+
+static const struct testcase_mgcp_codec_pt_translate test_mgcp_codec_pt_translate_cases[] = {
+	{
+		.descr = "same order, but differing payload type numbers",
+		.codecs = {
+			{
+				{ 112, "AMR/8000/1", &amr_param_octet_aligned_true, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 111, "GSM-HR-08/8000/1", NULL, },
+			},
+			{
+				{ 96, "AMR/8000/1", &amr_param_octet_aligned_true, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 97, "GSM-HR-08/8000/1", NULL, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, 96}, },
+			{ .payload_type_map = {0, 0}, },
+			{ .payload_type_map = {111, 97} },
+			{ .payload_type_map = {123, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "different order and different payload type numbers",
+		.codecs = {
+			{
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 111, "GSM-HR-08/8000/1", NULL, },
+				{ 112, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+			{
+				{ 97, "GSM-HR-08/8000/1", NULL, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 96, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, 96}, },
+			{ .payload_type_map = {0, 0}, },
+			{ .payload_type_map = {111, 97} },
+			{ .payload_type_map = {123, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "both sides have the same payload_type numbers assigned to differing codecs",
+		.codecs = {
+			{
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 96, "GSM-HR-08/8000/1", NULL, },
+				{ 97, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+			{
+				{ 97, "GSM-HR-08/8000/1", NULL, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 96, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {96, 97}, },
+			{ .payload_type_map = {97, 96}, },
+			{ .payload_type_map = {0, 0}, },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "conn0 has no codecs",
+		.codecs = {
+			{
+				/* no codecs */
+			},
+			{
+				{ 96, "AMR/8000/1", &amr_param_octet_aligned_true, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 97, "GSM-HR-08/8000/1", NULL, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, -EINVAL}, },
+			{ .payload_type_map = {0, -EINVAL}, },
+			{ .payload_type_map = {111, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "conn1 has no codecs",
+		.codecs = {
+			{
+				{ 112, "AMR/8000/1", &amr_param_octet_aligned_true, },
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 111, "GSM-HR-08/8000/1", NULL, },
+			},
+			{
+				/* no codecs */
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, -EINVAL}, },
+			{ .payload_type_map = {0, -EINVAL}, },
+			{ .payload_type_map = {111, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "test AMR with differing octet-aligned settings",
+		.codecs = {
+			{
+				{ 111, "AMR/8000", &amr_param_octet_aligned_true, },
+				{ 112, "AMR/8000", &amr_param_octet_aligned_false, },
+			},
+			{
+				{ 122, "AMR/8000", &amr_param_octet_aligned_false, },
+				{ 121, "AMR/8000", &amr_param_octet_aligned_true, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {111, 121}, },
+			{ .payload_type_map = {112, 122} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "test AMR with missing octet-aligned settings (defaults to 0)",
+		.codecs = {
+			{
+				{ 111, "AMR/8000", &amr_param_octet_aligned_true, },
+				{ 112, "AMR/8000", &amr_param_octet_aligned_false, },
+			},
+			{
+				{ 122, "AMR/8000", &amr_param_octet_aligned_unset, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {111, -EINVAL}, },
+			{ .payload_type_map = {112, 122} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "test AMR with NULL param (defaults to 0)",
+		.codecs = {
+			{
+				{ 111, "AMR/8000", &amr_param_octet_aligned_true, },
+				{ 112, "AMR/8000", &amr_param_octet_aligned_false, },
+			},
+			{
+				{ 122, "AMR/8000", NULL, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {111, -EINVAL}, },
+			{ .payload_type_map = {112, 122} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "match FOO/8000/1 and FOO/8000 as identical, single channel is implicit",
+		.codecs = {
+			{
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 111, "GSM-HR-08/8000/1", NULL, },
+				{ 112, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+			{
+				{ 97, "GSM-HR-08/8000", NULL, },
+				{ 0, "PCMU/8000", NULL, },
+				{ 96, "AMR/8000", &amr_param_octet_aligned_true, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, 96}, },
+			{ .payload_type_map = {0, 0}, },
+			{ .payload_type_map = {111, 97} },
+			{ .payload_type_map = {123, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "match FOO/8000/1 and FOO as identical, 8k and single channel are implicit",
+		.codecs = {
+			{
+				{ 0, "PCMU/8000/1", NULL, },
+				{ 111, "GSM-HR-08/8000/1", NULL, },
+				{ 112, "AMR/8000/1", &amr_param_octet_aligned_true, },
+			},
+			{
+				{ 97, "GSM-HR-08", NULL, },
+				{ 0, "PCMU", NULL, },
+				{ 96, "AMR", &amr_param_octet_aligned_true, },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {112, 96}, },
+			{ .payload_type_map = {0, 0}, },
+			{ .payload_type_map = {111, 97} },
+			{ .payload_type_map = {123, -EINVAL} },
+			{ .end = true },
+		},
+	},
+	{
+		.descr = "test whether channel number matching is waterproof",
+		.codecs = {
+			{
+				{ 111, "GSM-HR-08/8000", },
+				{ 112, "GSM-HR-08/8000/2", .expect_rc = -22},
+				{ 113, "GSM-HR-08/8000/3", .expect_rc = -22},
+			},
+			{
+				{ 122, "GSM-HR-08/8000/2", .expect_rc = -22},
+				{ 121, "GSM-HR-08/8000/1", },
+			},
+		},
+		.expect = {
+			{ .payload_type_map = {111, 121}, },
+			{ .payload_type_map = {112, -EINVAL} },
+			{ .payload_type_map = {113, -EINVAL} },
+			{ .end = true },
+		},
+	},
+};
 
 static void test_mgcp_codec_pt_translate(void)
 {
-	struct mgcp_conn_rtp conn_src;
-	struct mgcp_conn_rtp conn_dst;
-	int pt_dst;
+	int i;
+	bool ok = true;
+	printf("\nTesting mgcp_codec_pt_translate()\n");
 
-	/* Setup a realistic set of codec configurations on both
-	 * ends. AMR and HR will use different payload types. PCMU
-	 * must use 0 on both ends since this is not a dynamic payload
-	 * type */
-	test_mgcp_codec_pt_translate_pars(&conn_src.end.codecs[0]);
-	test_mgcp_codec_pt_translate_pars(&conn_dst.end.codecs[0]);
-	test_mgcp_codec_pt_translate_pars(&conn_src.end.codecs[1]);
-	test_mgcp_codec_pt_translate_pars(&conn_dst.end.codecs[1]);
-	test_mgcp_codec_pt_translate_pars(&conn_src.end.codecs[2]);
-	test_mgcp_codec_pt_translate_pars(&conn_dst.end.codecs[2]);
-	conn_src.end.codecs[0].payload_type = 112;
-	conn_dst.end.codecs[0].payload_type = 96;
-	conn_src.end.codecs[1].payload_type = 0;
-	conn_dst.end.codecs[1].payload_type = 0;
-	conn_src.end.codecs[2].payload_type = 111;
-	conn_dst.end.codecs[2].payload_type = 97;
-	conn_src.end.codecs[0].audio_name = "AMR/8000/1";
-	conn_dst.end.codecs[0].audio_name = "AMR/8000/1";
-	conn_src.end.codecs[1].audio_name = "PCMU/8000/1";
-	conn_dst.end.codecs[1].audio_name = "PCMU/8000/1";
-	conn_src.end.codecs[2].audio_name = "GSM-HR-08/8000/1";
-	conn_dst.end.codecs[2].audio_name = "GSM-HR-08/8000/1";
-	conn_src.end.codecs[0].subtype_name = "AMR";
-	conn_dst.end.codecs[0].subtype_name = "AMR";
-	conn_src.end.codecs[1].subtype_name = "PCMU";
-	conn_dst.end.codecs[1].subtype_name = "PCMU";
-	conn_src.end.codecs[2].subtype_name = "GSM-HR-08";
-	conn_dst.end.codecs[2].subtype_name = "GSM-HR-08";
-	conn_src.end.codecs_assigned = 3;
-	conn_dst.end.codecs_assigned = 3;
+	for (i = 0; i < ARRAY_SIZE(test_mgcp_codec_pt_translate_cases); i++) {
+		const struct testcase_mgcp_codec_pt_translate *t = &test_mgcp_codec_pt_translate_cases[i];
+		struct mgcp_conn_rtp conn[2] = {};
+		int rc;
+		int conn_i;
+		int c;
 
-	/* We expect the function to find the PT we must use when we send the
-	 * packet out to the destination. All we know is the context for both
-	 * connections and the payload type from the source packet */
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[0].payload_type);
-	OSMO_ASSERT(pt_dst == conn_dst.end.codecs[0].payload_type);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[1].payload_type);
-	OSMO_ASSERT(pt_dst == conn_dst.end.codecs[1].payload_type);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[2].payload_type);
-	OSMO_ASSERT(pt_dst == conn_dst.end.codecs[2].payload_type);
+		printf("#%d: %s\n", i, t->descr);
 
-	/* Try some constellations that must fail */
-	pt_dst = mgcp_codec_pt_translate(&conn_src, &conn_dst, 123);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	conn_src.end.codecs_assigned = 0;
-	conn_dst.end.codecs_assigned = 3;
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[0].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[1].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[2].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	conn_src.end.codecs_assigned = 3;
-	conn_dst.end.codecs_assigned = 0;
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[0].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[1].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
-	pt_dst =
-	    mgcp_codec_pt_translate(&conn_src, &conn_dst,
-				    conn_src.end.codecs[2].payload_type);
-	OSMO_ASSERT(pt_dst == -EINVAL);
+		for (conn_i = 0; conn_i < 2; conn_i++) {
+			printf(" - add codecs on conn%d:\n", conn_i);
+			for (c = 0; c < ARRAY_SIZE(t->codecs[conn_i]); c++) {
+				const struct testcase_mgcp_codec_pt_translate_codec *codec = &t->codecs[conn_i][c];
+				if (!codec->audio_name)
+					break;
+
+				rc = mgcp_codec_add(&conn[conn_i], codec->payload_type, codec->audio_name, codec->param);
+
+				printf("   %2d: %3d %s%s  -> rc=%d\n", c, codec->payload_type, codec->audio_name,
+				       codec->param ?
+					       (codec->param->amr_octet_aligned_present?
+							(codec->param->amr_octet_aligned ?
+								" octet-aligned=1" : " octet-aligned=0")
+							: " octet-aligned=unset")
+						: "",
+						rc);
+				if (rc != codec->expect_rc) {
+					printf("     ERROR: expected rc=%d\n", codec->expect_rc);
+					ok = false;
+				}
+			}
+			if (!c)
+				printf("    (none)\n");
+		}
+
+		for (c = 0; c < ARRAY_SIZE(t->expect); c++) {
+			const struct testcase_mgcp_codec_pt_translate_expect *expect = &t->expect[c];
+			int result;
+
+			if (expect->end)
+				break;
+
+			result = mgcp_codec_pt_translate(&conn[0], &conn[1], expect->payload_type_map[0]);
+			printf(" - mgcp_codec_pt_translate(conn0, conn1, %d) -> %d\n",
+			       expect->payload_type_map[0], result);
+			if (result != expect->payload_type_map[1]) {
+				printf("     ERROR: expected -> %d\n", expect->payload_type_map[1]);
+				ok = false;
+			}
+
+			/* If the expected result is an error, don't do reverse map test */
+			if (expect->payload_type_map[1] < 0)
+				continue;
+
+			result = mgcp_codec_pt_translate(&conn[1], &conn[0], expect->payload_type_map[1]);
+			printf(" - mgcp_codec_pt_translate(conn1, conn0, %d) -> %d\n",
+			       expect->payload_type_map[1], result);
+			if (result != expect->payload_type_map[0]) {
+				printf("     ERROR: expected -> %d\n", expect->payload_type_map[0]);
+				ok = false;
+			}
+		}
+
+		for (conn_i = 0; conn_i < 2; conn_i++)
+			mgcp_codec_reset_all(&conn[conn_i]);
+	}
+
+	OSMO_ASSERT(ok);
 }
 
 void test_conn_id_matching()

tests/mgcp/mgcp_test.ok

@@ -1218,6 +1218,148 @@ p:10, a:PCMU -> p:10, a:PCMU
 Testing get_lco_identifier()
 p:10, a:PCMU -> p:10, a:PCMU
 p:10, a:PCMU -> p:10, a:PCMU
+'XXXX, p:10, a:PCMU' -> 'p:10, a:PCMU'
+'XXXX,p:10,a:PCMU' -> 'p:10,a:PCMU'
+'10,a:PCMU' -> 'a:PCMU'
+'10, a:PCMU' -> 'a:PCMU'
+'10,a: PCMU' -> 'a: PCMU'
+'10 ,a: PCMU' -> 'a: PCMU'
+', a:PCMU' -> 'a:PCMU'
+' a:PCMU' -> 'a:PCMU'
+'' -> '(null)'
+p10, aPCMU -> (null)
+'10,a :PCMU' -> '(null)'
+
+Testing mgcp_codec_pt_translate()
+#0: same order, but differing payload type numbers
+ - add codecs on conn0:
+    0: 112 AMR/8000/1 octet-aligned=1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2: 111 GSM-HR-08/8000/1  -> rc=0
+ - add codecs on conn1:
+    0:  96 AMR/8000/1 octet-aligned=1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2:  97 GSM-HR-08/8000/1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
+ - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
+ - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
+ - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
+ - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+#1: different order and different payload type numbers
+ - add codecs on conn0:
+    0:   0 PCMU/8000/1  -> rc=0
+    1: 111 GSM-HR-08/8000/1  -> rc=0
+    2: 112 AMR/8000/1 octet-aligned=1  -> rc=0
+ - add codecs on conn1:
+    0:  97 GSM-HR-08/8000/1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2:  96 AMR/8000/1 octet-aligned=1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
+ - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
+ - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
+ - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
+ - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+#2: both sides have the same payload_type numbers assigned to differing codecs
+ - add codecs on conn0:
+    0:   0 PCMU/8000/1  -> rc=0
+    1:  96 GSM-HR-08/8000/1  -> rc=0
+    2:  97 AMR/8000/1 octet-aligned=1  -> rc=0
+ - add codecs on conn1:
+    0:  97 GSM-HR-08/8000/1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2:  96 AMR/8000/1 octet-aligned=1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 96) -> 97
+ - mgcp_codec_pt_translate(conn1, conn0, 97) -> 96
+ - mgcp_codec_pt_translate(conn0, conn1, 97) -> 96
+ - mgcp_codec_pt_translate(conn1, conn0, 96) -> 97
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
+ - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
+#3: conn0 has no codecs
+ - add codecs on conn0:
+    (none)
+ - add codecs on conn1:
+    0:  96 AMR/8000/1 octet-aligned=1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2:  97 GSM-HR-08/8000/1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+#4: conn1 has no codecs
+ - add codecs on conn0:
+    0: 112 AMR/8000/1 octet-aligned=1  -> rc=0
+    1:   0 PCMU/8000/1  -> rc=0
+    2: 111 GSM-HR-08/8000/1  -> rc=0
+ - add codecs on conn1:
+    (none)
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+#5: test AMR with differing octet-aligned settings
+ - add codecs on conn0:
+    0: 111 AMR/8000 octet-aligned=1  -> rc=0
+    1: 112 AMR/8000 octet-aligned=0  -> rc=0
+ - add codecs on conn1:
+    0: 122 AMR/8000 octet-aligned=0  -> rc=0
+    1: 121 AMR/8000 octet-aligned=1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> 121
+ - mgcp_codec_pt_translate(conn1, conn0, 121) -> 111
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
+ - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
+#6: test AMR with missing octet-aligned settings (defaults to 0)
+ - add codecs on conn0:
+    0: 111 AMR/8000 octet-aligned=1  -> rc=0
+    1: 112 AMR/8000 octet-aligned=0  -> rc=0
+ - add codecs on conn1:
+    0: 122 AMR/8000 octet-aligned=unset  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
+ - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
+#7: test AMR with NULL param (defaults to 0)
+ - add codecs on conn0:
+    0: 111 AMR/8000 octet-aligned=1  -> rc=0
+    1: 112 AMR/8000 octet-aligned=0  -> rc=0
+ - add codecs on conn1:
+    0: 122 AMR/8000  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> -22
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 122
+ - mgcp_codec_pt_translate(conn1, conn0, 122) -> 112
+#8: match FOO/8000/1 and FOO/8000 as identical, single channel is implicit
+ - add codecs on conn0:
+    0:   0 PCMU/8000/1  -> rc=0
+    1: 111 GSM-HR-08/8000/1  -> rc=0
+    2: 112 AMR/8000/1 octet-aligned=1  -> rc=0
+ - add codecs on conn1:
+    0:  97 GSM-HR-08/8000  -> rc=0
+    1:   0 PCMU/8000  -> rc=0
+    2:  96 AMR/8000 octet-aligned=1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
+ - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
+ - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
+ - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
+ - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+#9: match FOO/8000/1 and FOO as identical, 8k and single channel are implicit
+ - add codecs on conn0:
+    0:   0 PCMU/8000/1  -> rc=0
+    1: 111 GSM-HR-08/8000/1  -> rc=0
+    2: 112 AMR/8000/1 octet-aligned=1  -> rc=0
+ - add codecs on conn1:
+    0:  97 GSM-HR-08  -> rc=0
+    1:   0 PCMU  -> rc=0
+    2:  96 AMR octet-aligned=1  -> rc=0
+ - mgcp_codec_pt_translate(conn0, conn1, 112) -> 96
+ - mgcp_codec_pt_translate(conn1, conn0, 96) -> 112
+ - mgcp_codec_pt_translate(conn0, conn1, 0) -> 0
+ - mgcp_codec_pt_translate(conn1, conn0, 0) -> 0
+ - mgcp_codec_pt_translate(conn0, conn1, 111) -> 97
+ - mgcp_codec_pt_translate(conn1, conn0, 97) -> 111
+ - mgcp_codec_pt_translate(conn0, conn1, 123) -> -22
+#10: test whether channel number matching is waterproof
  - add codecs on conn0:
     0: 111 GSM-HR-08/8000  -> rc=0
     1: 112 GSM-HR-08/8000/2  -> rc=-22

tests/testsuite.at

@@ -13,3 +13,10 @@ AT_KEYWORDS([mgcp])
 cat $abs_srcdir/mgcp/mgcp_test.ok > expout
 AT_CHECK([$abs_top_builddir/tests/mgcp/mgcp_test], [], [expout], [ignore])
 AT_CLEANUP
+
+AT_SETUP([iuup])
+AT_KEYWORDS([iuup])
+cat $abs_srcdir/iuup/iuup_test.ok > expout
+cat $abs_srcdir/iuup/iuup_test.err > experr
+AT_CHECK([$abs_top_builddir/tests/iuup/iuup_test], [], [expout], [experr])
+AT_CLEANUP