libosmocc: Add support for individual session config (per endpoint)

12 files changed, 85 insertions, 72 deletions

diff --git a/src/libmobile/call.c b/src/libmobile/call.c
index f7db1f8..5aefa7b 100644
--- a/src/libmobile/call.c
+++ b/src/libmobile/call.c
@@ -419,7 +419,7 @@ static void indicate_setup(process_t *process, const char *callerid, const char
 	/* bearer capability */
 	osmo_cc_add_ie_bearer(msg, OSMO_CC_CODING_ITU_T, OSMO_CC_CAPABILITY_AUDIO, OSMO_CC_MODE_CIRCUIT);
 	/* sdp offer */
-	process->session = osmo_cc_helper_audio_offer(process, codecs, down_audio, msg, 1);
+	process->session = osmo_cc_helper_audio_offer(&ep->session_config, process, codecs, down_audio, msg, 1);
 
 	PDEBUG(DCALL, DEBUG_INFO, "Indicate OSMO-CC setup towards fixed network\n");
 	osmo_cc_ll_msg(ep, process->callref, msg);
@@ -705,7 +705,7 @@ void ll_msg_cb(osmo_cc_endpoint_t __attribute__((unused)) *ep, uint32_t callref,
 		const char *sdp;
 
 		/* sdp accept */
-		sdp = osmo_cc_helper_audio_accept(process, codecs, down_audio, msg, &process->session, &process->codec, 0);
+		sdp = osmo_cc_helper_audio_accept(&ep->session_config, process, codecs, down_audio, msg, &process->session, &process->codec, 0);
 		if (!sdp) {
 			disconnect_process(callref, 47);
 			break;
diff --git a/src/libmobile/console.c b/src/libmobile/console.c
index df3323a..a1198a9 100644
--- a/src/libmobile/console.c
+++ b/src/libmobile/console.c
@@ -176,7 +176,7 @@ static void request_setup(int callref, const char *dialing)
 	/* bearer capability */
 	osmo_cc_add_ie_bearer(msg, OSMO_CC_CODING_ITU_T, OSMO_CC_CAPABILITY_AUDIO, OSMO_CC_MODE_CIRCUIT);
 	/* sdp offer */
-	console.session = osmo_cc_helper_audio_offer(NULL, codecs, up_audio, msg, 1);
+	console.session = osmo_cc_helper_audio_offer(&ep->session_config, NULL, codecs, up_audio, msg, 1);
 
 	osmo_cc_ul_msg(ep, callref, msg);
 }
@@ -261,7 +261,7 @@ void console_msg(osmo_cc_call_t *call, osmo_cc_msg_t *msg)
 		}
 		console.callref = call->callref;
 		/* sdp accept */
-		sdp = osmo_cc_helper_audio_accept(NULL, codecs, up_audio, msg, &console.session, &console.codec, 0);
+		sdp = osmo_cc_helper_audio_accept(&ep->session_config, NULL, codecs, up_audio, msg, &console.session, &console.codec, 0);
 		if (!sdp) {
 			PDEBUG(DCC, DEBUG_NOTICE, "Cannot accept codec, rejecting.\n");
 			request_disconnect_release_reject(console.callref, CAUSE_RESOURCE_UNAVAIL, OSMO_CC_MSG_REJ_REQ);
diff --git a/src/libosmocc/endpoint.c b/src/libosmocc/endpoint.c
index 481926d..1a7e3a3 100644
--- a/src/libosmocc/endpoint.c
+++ b/src/libosmocc/endpoint.c
@@ -1155,7 +1155,7 @@ static int osmo_cc_set_address(osmo_cc_endpoint_t *ep, const char *text)
 			PDEBUG(DCC, DEBUG_ERROR, "Given local address '%s' is invalid.\n", *host_p);
 			return -EINVAL;
 		}
-		osmo_cc_set_local_peer(osmo_cc_session_nettype_inet, addrtype, *host_p);
+		osmo_cc_set_local_peer(&ep->session_config, osmo_cc_session_nettype_inet, addrtype, *host_p);
 		return 0;
 	}
 
@@ -1175,7 +1175,7 @@ static void osmo_cc_help_rtp(void)
 	printf("interfaces, between machines, local machine's IP must be given.\n\n");
 }
 
-static int osmo_cc_set_rtp(const char *text)
+static int osmo_cc_set_rtp(osmo_cc_endpoint_t *ep, const char *text)
 {
 	int peer = 0, ports = 0;
 
@@ -1204,7 +1204,7 @@ static int osmo_cc_set_rtp(const char *text)
 			PDEBUG(DCC, DEBUG_ERROR, "Given RTP address '%s' is invalid.\n", text);
 			return -EINVAL;
 		}
-		osmo_cc_set_local_peer(osmo_cc_session_nettype_inet, addrtype, text);
+		osmo_cc_set_local_peer(&ep->session_config, osmo_cc_session_nettype_inet, addrtype, text);
 		return 0;
 	}
 
@@ -1236,7 +1236,7 @@ static int osmo_cc_set_rtp(const char *text)
 			from = from * 10 + *text - '0';
 		}
 
-		osmo_cc_set_rtp_ports(from, to);
+		osmo_cc_set_rtp_ports(&ep->session_config, from, to);
 		return 0;
 	}
 
@@ -1279,6 +1279,9 @@ int osmo_cc_new(osmo_cc_endpoint_t *ep, const char *version, const char *name, u
 	ep->serving_location = serving_location;
 	ep->priv = priv;
 
+	osmo_cc_set_local_peer(&ep->session_config, osmo_cc_session_nettype_inet, osmo_cc_session_addrtype_ipv4, "127.0.0.1");
+	osmo_cc_set_rtp_ports(&ep->session_config, 16384, 32767);
+
 	/* apply args */
 	for (i = 0; i < argc; i++) {
 		if (!strncasecmp(argv[i], "local", 5)) {
@@ -1294,7 +1297,7 @@ int osmo_cc_new(osmo_cc_endpoint_t *ep, const char *version, const char *name, u
 			}
 		} else
 		if (!strncasecmp(argv[i], "rtp", 3)) {
-			rc = osmo_cc_set_rtp(argv[i]);
+			rc = osmo_cc_set_rtp(ep, argv[i]);
 			if (rc < 0) {
 				return rc;
 			}
diff --git a/src/libosmocc/endpoint.h b/src/libosmocc/endpoint.h
index 7c16dca..4425532 100644
--- a/src/libosmocc/endpoint.h
+++ b/src/libosmocc/endpoint.h
@@ -45,6 +45,8 @@ typedef int16_t osmo_cc_sample_t;
 #define OSMO_CC_SAMPLE_MIN -32768 /* lowest level */
 #define OSMO_CC_SAMPLE_MAX 32767 /* highest level */
 
+#include "session.h"
+
 struct osmo_cc_call;
 
 typedef struct osmo_cc_screen_list {
@@ -84,6 +86,7 @@ typedef struct osmo_cc_endpoint {
 	osmo_cc_screen_list_t	*screen_called_out;
 	int			remote_auto;	/* automatic remote address */
 	struct timer		attach_timer;	/* timer to retry attachment */
+	osmo_cc_session_config_t session_config; /* SDP/RTP default configuration */
 } osmo_cc_endpoint_t;
 
 extern osmo_cc_endpoint_t *osmo_cc_endpoint_list;
@@ -121,7 +124,6 @@ enum osmo_cc_session_addrtype osmo_cc_address_type(const char *address);
 const char *osmo_cc_host_of_address(const char *address);
 const char *osmo_cc_port_of_address(const char *address);
 
-#include "session.h"
 #include "rtp.h"
 #include "sdp.h"
 #include "screen.h"
diff --git a/src/libosmocc/helper.c b/src/libosmocc/helper.c
index 6317ed3..807542e 100644
--- a/src/libosmocc/helper.c
+++ b/src/libosmocc/helper.c
@@ -29,14 +29,14 @@
 #include "endpoint.h"
 #include "helper.h"
 
-osmo_cc_session_t *osmo_cc_helper_audio_offer(void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, int debug)
+osmo_cc_session_t *osmo_cc_helper_audio_offer(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, int debug)
 {
 	osmo_cc_session_t *session;
 	osmo_cc_session_media_t *media;
 	const char *sdp;
 	int i;
 
-	session = osmo_cc_new_session(priv, NULL, NULL, NULL, 0, 0, NULL, NULL, debug);
+	session = osmo_cc_new_session(conf, priv, NULL, NULL, NULL, 0, 0, NULL, NULL, debug);
 	if (!session)
 		return NULL;
 
@@ -52,7 +52,7 @@ osmo_cc_session_t *osmo_cc_helper_audio_offer(void *priv, struct osmo_cc_helper_
 	return session;
 }
 
-const char *osmo_cc_helper_audio_accept(void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec)
+const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec)
 {
 	char offer_sdp[65536];
 	const char *accept_sdp;
@@ -77,7 +77,7 @@ const char *osmo_cc_helper_audio_accept(void *priv, struct osmo_cc_helper_audio_
 		return NULL;
 	}
 
-	*session_p = osmo_cc_session_receive_offer(priv, offer_sdp);
+	*session_p = osmo_cc_session_receive_offer(conf, priv, offer_sdp);
 	if (!*session_p) {
 		PDEBUG(DCC, DEBUG_ERROR, "Failed to parse SDP.\n");
 		return NULL;
diff --git a/src/libosmocc/helper.h b/src/libosmocc/helper.h
index e3acf0e..c12a50a 100644
--- a/src/libosmocc/helper.h
+++ b/src/libosmocc/helper.h
@@ -7,7 +7,7 @@ struct osmo_cc_helper_audio_codecs {
 	void (*decoder)(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len);
 };
 
-osmo_cc_session_t *osmo_cc_helper_audio_offer(void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, int debug);
-const char *osmo_cc_helper_audio_accept(void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec);
+osmo_cc_session_t *osmo_cc_helper_audio_offer(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, int debug);
+const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec);
 int osmo_cc_helper_audio_negotiate(osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p);
 
diff --git a/src/libosmocc/rtp.c b/src/libosmocc/rtp.c
index a6de25a..afaf22d 100644
--- a/src/libosmocc/rtp.c
+++ b/src/libosmocc/rtp.c
@@ -32,15 +32,11 @@
 
 #define RTP_VERSION 2
 
-static uint16_t rtp_port_next = 16384;
-static uint16_t rtp_port_from = 16384;
-static uint16_t rtp_port_to = 32767;
-
-void osmo_cc_set_rtp_ports(uint16_t from, uint16_t to)
+void osmo_cc_set_rtp_ports(osmo_cc_session_config_t *conf, uint16_t from, uint16_t to)
 {
-	rtp_port_next = from;
-	rtp_port_from = from;
-	rtp_port_to = to;
+	conf->rtp_port_next = from;
+	conf->rtp_port_from = from;
+	conf->rtp_port_to = to;
 }
 
 struct rtp_hdr {
@@ -165,6 +161,7 @@ static void rtp_send(int sock, uint8_t *payload, int payload_len, uint8_t pt, ui
  */
 int osmo_cc_rtp_open(osmo_cc_session_media_t *media)
 {
+	osmo_cc_session_config_t *conf = media->session->config;
 	int domain = 0; // make GCC happy
 	uint16_t start_port;
 	struct sockaddr_storage sa;
@@ -204,9 +201,9 @@ int osmo_cc_rtp_open(osmo_cc_session_media_t *media)
 	}
 
 	/* rtp_port_from/rtp_port_to may be changed at run time, so rtp_port_next can become out of range. */
-	if (rtp_port_next < rtp_port_from || rtp_port_next > rtp_port_to)
-		rtp_port_next = rtp_port_from;
-	start_port = rtp_port_next;
+	if (conf->rtp_port_next < conf->rtp_port_from || conf->rtp_port_next > conf->rtp_port_to)
+		conf->rtp_port_next = conf->rtp_port_from;
+	start_port = conf->rtp_port_next;
 	while (1) {
 		/* open sockets */
 		rc = socket(domain, SOCK_DGRAM, IPPROTO_UDP);
@@ -223,24 +220,24 @@ socket_error:
 		media->rtcp_socket = rc;
 
 		/* bind sockets */
-		*sport = htons(rtp_port_next);
+		*sport = htons(conf->rtp_port_next);
 		rc = bind(media->rtp_socket, (struct sockaddr *)&sa, slen);
 		if (rc < 0) {
 bind_error:
 			osmo_cc_rtp_close(media);
-			rtp_port_next = (rtp_port_next + 2 > rtp_port_to) ? rtp_port_from : rtp_port_next + 2;
-			if (rtp_port_next == start_port) {
+			conf->rtp_port_next = (conf->rtp_port_next + 2 > conf->rtp_port_to) ? conf->rtp_port_from : conf->rtp_port_next + 2;
+			if (conf->rtp_port_next == start_port) {
 				PDEBUG(DCC, DEBUG_ERROR, "Cannot bind socket (errno=%d(%s))\n", errno, strerror(errno));
 				return -EIO;
 			}
 			continue;
 		}
-		*sport = htons(rtp_port_next + 1);
+		*sport = htons(conf->rtp_port_next + 1);
 		rc = bind(media->rtcp_socket, (struct sockaddr *)&sa, slen);
 		if (rc < 0)
 			goto bind_error;
-		media->description.port_local = rtp_port_next;
-		rtp_port_next = (rtp_port_next + 2 > rtp_port_to) ? rtp_port_from : rtp_port_next + 2;
+		media->description.port_local = conf->rtp_port_next;
+		conf->rtp_port_next = (conf->rtp_port_next + 2 > conf->rtp_port_to) ? conf->rtp_port_from : conf->rtp_port_next + 2;
 		/* set nonblocking io */
 		flags = fcntl(media->rtp_socket, F_GETFL);
 		flags |= O_NONBLOCK;
diff --git a/src/libosmocc/rtp.h b/src/libosmocc/rtp.h
index 47d748c..e309f56 100644
--- a/src/libosmocc/rtp.h
+++ b/src/libosmocc/rtp.h
@@ -1,5 +1,5 @@
 
-void osmo_cc_set_rtp_ports(uint16_t from, uint16_t to);
+void osmo_cc_set_rtp_ports(osmo_cc_session_config_t *conf, uint16_t from, uint16_t to);
 int osmo_cc_rtp_open(osmo_cc_session_media_t *media);
 int osmo_cc_rtp_connect(osmo_cc_session_media_t *media);
 void osmo_cc_rtp_send(osmo_cc_session_codec_t *codec, uint8_t *data, int len, int inc_sequence, int inc_timestamp);
diff --git a/src/libosmocc/sdp.c b/src/libosmocc/sdp.c
index 0f8bca9..8e44117 100644
--- a/src/libosmocc/sdp.c
+++ b/src/libosmocc/sdp.c
@@ -244,7 +244,7 @@ int osmo_cc_payload_type_by_attrs(uint8_t *fmt, const char *name, uint32_t *rate
  *
  * sdp = given SDP text
  * return: SDP session description structure */
-struct osmo_cc_session *osmo_cc_session_parsesdp(void *priv, const char *_sdp)
+struct osmo_cc_session *osmo_cc_session_parsesdp(osmo_cc_session_config_t *conf, void *priv, const char *_sdp)
 {
 	char buffer[strlen(_sdp) + 1], *sdp = buffer;
 	char *line, *p, *word, *next_word;
@@ -260,7 +260,7 @@ struct osmo_cc_session *osmo_cc_session_parsesdp(void *priv, const char *_sdp)
 	memset(&ccd, 0, sizeof(ccd));
 
 	/* create SDP session description */
-	session = osmo_cc_new_session(priv, NULL, NULL, NULL, osmo_cc_session_nettype_inet, osmo_cc_session_addrtype_ipv4, "127.0.0.1", NULL, 0); // values will be replaced by local definitions during negotiation
+	session = osmo_cc_new_session(conf, priv, NULL, NULL, NULL, osmo_cc_session_nettype_inet, osmo_cc_session_addrtype_ipv4, "127.0.0.1", NULL, 0); // values will be replaced by local definitions during negotiation
 
 	/* check every line of SDP and parse its data */
 	while(*sdp) {
diff --git a/src/libosmocc/sdp.h b/src/libosmocc/sdp.h
index 4aa6f60..c9bc721 100644
--- a/src/libosmocc/sdp.h
+++ b/src/libosmocc/sdp.h
@@ -1,6 +1,6 @@
 
 char *osmo_cc_session_gensdp(struct osmo_cc_session *session);
-struct osmo_cc_session *osmo_cc_session_parsesdp(void *priv, const char *_sdp);
+struct osmo_cc_session *osmo_cc_session_parsesdp(osmo_cc_session_config_t *conf, void *priv, const char *_sdp);
 int osmo_cc_payload_type_by_attrs(uint8_t *fmt, const char *name, uint32_t *rate, int *channels);
 void osmo_cc_debug_sdp(const char *sdp);
 
diff --git a/src/libosmocc/session.c b/src/libosmocc/session.c
index 1438ae2..50a4a92 100644
--- a/src/libosmocc/session.c
+++ b/src/libosmocc/session.c
@@ -31,18 +31,14 @@
 
 #define NTP_OFFSET      2208988800
 
-enum osmo_cc_session_nettype default_nettype = osmo_cc_session_nettype_inet;
-enum osmo_cc_session_addrtype default_addrtype = osmo_cc_session_addrtype_ipv4;
-const char *default_unicast_address = "127.0.0.1";
-
-void osmo_cc_set_local_peer(enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address)
+void osmo_cc_set_local_peer(osmo_cc_session_config_t *conf, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address)
 {
-	default_nettype = nettype;
-	default_addrtype = addrtype;
-	default_unicast_address = options_strdup(address);
+	conf->default_nettype = nettype;
+	conf->default_addrtype = addrtype;
+	conf->default_unicast_address = options_strdup(address);
 }
 
-osmo_cc_session_t *osmo_cc_new_session(void *priv, const char *username, const char *sess_id, const char *sess_version, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *unicast_address, const char *session_name, int debug)
+osmo_cc_session_t *osmo_cc_new_session(osmo_cc_session_config_t *conf, void *priv, const char *username, const char *sess_id, const char *sess_version, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *unicast_address, const char *session_name, int debug)
 {
 	osmo_cc_session_t *session;
 
@@ -53,6 +49,7 @@ osmo_cc_session_t *osmo_cc_new_session(void *priv, const char *username, const c
 		PDEBUG(DCC, DEBUG_ERROR, "No mem!\n");
 		abort();
 	}
+	session->config = conf;
 	session->priv = priv;
 	if (username) {
 		int i;
@@ -87,17 +84,17 @@ osmo_cc_session_t *osmo_cc_new_session(void *priv, const char *username, const c
 	if (nettype)
 		session->origin_local.nettype = strdup(osmo_cc_session_nettype2string(nettype));
 	else
-		session->origin_local.nettype = strdup(osmo_cc_session_nettype2string(default_nettype));
+		session->origin_local.nettype = strdup(osmo_cc_session_nettype2string(conf->default_nettype));
 	if (debug) PDEBUG(DCC, DEBUG_DEBUG, " -> network type = %s\n", session->origin_local.nettype);
 	if (addrtype)
 		session->origin_local.addrtype = strdup(osmo_cc_session_addrtype2string(addrtype));
 	else
-		session->origin_local.addrtype = strdup(osmo_cc_session_addrtype2string(default_addrtype));
+		session->origin_local.addrtype = strdup(osmo_cc_session_addrtype2string(conf->default_addrtype));
 	if (debug) PDEBUG(DCC, DEBUG_DEBUG, " -> address type = %s\n", session->origin_local.addrtype);
 	if (unicast_address)
 		session->origin_local.unicast_address = strdup(unicast_address);
 	else
-		session->origin_local.unicast_address = strdup(default_unicast_address);
+		session->origin_local.unicast_address = strdup(conf->default_unicast_address);
 	if (debug) PDEBUG(DCC, DEBUG_DEBUG, " -> unicast address = %s\n", session->origin_local.unicast_address);
 	if (session_name)
 		session->name = strdup(session_name);
@@ -132,6 +129,7 @@ void osmo_cc_free_session(osmo_cc_session_t *session)
 
 osmo_cc_session_media_t *osmo_cc_add_media(osmo_cc_session_t *session, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address, enum osmo_cc_session_media_type type, uint16_t port, enum osmo_cc_session_media_proto proto, int send, int receive, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), int debug)
 {
+	osmo_cc_session_config_t *conf = session->config;
 	osmo_cc_session_media_t *media, **mediap;
 
 	media = calloc(1, sizeof(*media));
@@ -143,15 +141,15 @@ osmo_cc_session_media_t *osmo_cc_add_media(osmo_cc_session_t *session, enum osmo
 	if (nettype)
 		media->connection_data_local.nettype = nettype;
 	else
-		media->connection_data_local.nettype = default_nettype;
+		media->connection_data_local.nettype = conf->default_nettype;
 	if (addrtype)
 		media->connection_data_local.addrtype = addrtype;
 	else
-		media->connection_data_local.addrtype = default_addrtype;
+		media->connection_data_local.addrtype = conf->default_addrtype;
 	if (address)
 		media->connection_data_local.address = strdup(address);
 	else
-		media->connection_data_local.address = strdup(default_unicast_address);
+		media->connection_data_local.address = strdup(conf->default_unicast_address);
 	media->description.type = type;
 	media->description.port_local = port;
 	media->description.proto = proto;
@@ -355,7 +353,7 @@ const char *osmo_cc_session_send_offer(osmo_cc_session_t *session)
 	return sdp;
 }
 
-osmo_cc_session_t *osmo_cc_session_receive_offer(void *priv, const char *sdp)
+osmo_cc_session_t *osmo_cc_session_receive_offer(osmo_cc_session_config_t *conf, void *priv, const char *sdp)
 {
 	osmo_cc_session_t *session;
 	int rc;
@@ -363,7 +361,7 @@ osmo_cc_session_t *osmo_cc_session_receive_offer(void *priv, const char *sdp)
 	PDEBUG(DCC, DEBUG_DEBUG, "Parsing session offer.\n");
 
 	osmo_cc_debug_sdp(sdp);
-	session = osmo_cc_session_parsesdp(priv, sdp);
+	session = osmo_cc_session_parsesdp(conf, priv, sdp);
 	if (!session)
 		return NULL;
 
@@ -378,20 +376,22 @@ osmo_cc_session_t *osmo_cc_session_receive_offer(void *priv, const char *sdp)
 
 void osmo_cc_session_accept_media(osmo_cc_session_media_t *media, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address, int send, int receive, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len))
 {
+	osmo_cc_session_config_t *conf = media->session->config;
+
 	media->accepted = 1;
 	if (nettype)
 		media->connection_data_local.nettype = nettype;
 	else
-		media->connection_data_local.nettype = default_nettype;
+		media->connection_data_local.nettype = conf->default_nettype;
 	if (addrtype)
 		media->connection_data_local.addrtype = addrtype;
 	else
-		media->connection_data_local.addrtype = default_addrtype;
+		media->connection_data_local.addrtype = conf->default_addrtype;
 	free((char *)media->connection_data_local.address);
 	if (address)
 		media->connection_data_local.address = strdup(address);
 	else
-		media->connection_data_local.address = strdup(default_unicast_address);
+		media->connection_data_local.address = strdup(conf->default_unicast_address);
 	media->send = send;
 	media->receive = receive;
 	media->receiver = receiver;
@@ -552,7 +552,7 @@ int osmo_cc_session_receive_answer(osmo_cc_session_t *session, const char *sdp)
 	PDEBUG(DCC, DEBUG_DEBUG, "Parsing session answer.\n");
 
 	osmo_cc_debug_sdp(sdp);
-	session_remote = osmo_cc_session_parsesdp(NULL, sdp);
+	session_remote = osmo_cc_session_parsesdp(session->config, NULL, sdp);
 	if (!session_remote)
 		return -EINVAL;
 
diff --git a/src/libosmocc/session.h b/src/libosmocc/session.h
index cab8fea..c0717c0 100644
--- a/src/libosmocc/session.h
+++ b/src/libosmocc/session.h
@@ -1,3 +1,24 @@
+/* configuration */
+
+enum osmo_cc_session_nettype {
+	osmo_cc_session_nettype_unknown = 0,
+	osmo_cc_session_nettype_inet,
+};
+
+enum osmo_cc_session_addrtype {
+	osmo_cc_session_addrtype_unknown = 0,
+	osmo_cc_session_addrtype_ipv4,
+	osmo_cc_session_addrtype_ipv6,
+};
+
+typedef struct osmo_cc_session_config {
+	enum osmo_cc_session_nettype default_nettype;
+	enum osmo_cc_session_addrtype default_addrtype;
+	const char *default_unicast_address;
+	uint16_t rtp_port_next;
+	uint16_t rtp_port_from;
+	uint16_t rtp_port_to;
+} osmo_cc_session_config_t;
 
 /* session description, global part: */
 
@@ -12,6 +33,7 @@ typedef struct osmo_cc_session_origin {
 
 /* session instance */
 typedef struct osmo_cc_session {
+	osmo_cc_session_config_t *config;
 	void *priv;
 	osmo_cc_session_origin_t origin_local, origin_remote;
 	const char *name;
@@ -20,17 +42,6 @@ typedef struct osmo_cc_session {
 
 /* connection description: */
 
-enum osmo_cc_session_nettype {
-	osmo_cc_session_nettype_unknown = 0,
-	osmo_cc_session_nettype_inet,
-};
-
-enum osmo_cc_session_addrtype {
-	osmo_cc_session_addrtype_unknown = 0,
-	osmo_cc_session_addrtype_ipv4,
-	osmo_cc_session_addrtype_ipv6,
-};
-
 typedef struct osmo_cc_session_connection_data {
 	enum osmo_cc_session_nettype nettype;
 	const char *nettype_name;
@@ -96,8 +107,8 @@ typedef struct osmo_cc_session_codec {
 #define osmo_cc_session_for_each_codec(head, c) \
 	for (c = (head); c; c = c->next)
 
-void osmo_cc_set_local_peer(enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address);
-osmo_cc_session_t *osmo_cc_new_session(void *priv, const char *username, const char *sess_id, const char *sess_version, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *unicast_address, const char *session_name, int debug);
+void osmo_cc_set_local_peer(osmo_cc_session_config_t *conf, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address);
+osmo_cc_session_t *osmo_cc_new_session(osmo_cc_session_config_t *conf, void *priv, const char *username, const char *sess_id, const char *sess_version, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *unicast_address, const char *session_name, int debug);
 void osmo_cc_free_session(osmo_cc_session_t *session);
 osmo_cc_session_media_t *osmo_cc_add_media(osmo_cc_session_t *session, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address, enum osmo_cc_session_media_type type, uint16_t port, enum osmo_cc_session_media_proto proto, int send, int receive, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len), int debug);
 void osmo_cc_free_media(osmo_cc_session_media_t *media);
@@ -105,7 +116,7 @@ osmo_cc_session_codec_t *osmo_cc_add_codec(osmo_cc_session_media_t *media, const
 void osmo_cc_free_codec(osmo_cc_session_codec_t *codec);
 int osmo_cc_session_check(struct osmo_cc_session *session, int remote);
 const char *osmo_cc_session_send_offer(osmo_cc_session_t *session);
-osmo_cc_session_t *osmo_cc_session_receive_offer(void *priv, const char *sdp);
+osmo_cc_session_t *osmo_cc_session_receive_offer(osmo_cc_session_config_t *conf, void *priv, const char *sdp);
 void osmo_cc_session_accept_media(osmo_cc_session_media_t *media, enum osmo_cc_session_nettype nettype, enum osmo_cc_session_addrtype addrtype, const char *address, int send, int receive, void (*receiver)(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint8_t *data, int len));
 void osmo_cc_session_accept_codec(osmo_cc_session_codec_t *codec, void (*encoder)(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len), void (*decoder)(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len));
 const char *osmo_cc_session_send_answer(osmo_cc_session_t *session);