Implement IuCS (large refactoring and addition)

osmo-nitb becomes osmo-msc
add DIUCS debug log constant
add iucs.[hc]
add msc vty, remove nitb vty
add libiudummy, to avoid linking Iu deps in tests
Use new msc_tx_dtap() instead of gsm0808_submit_dtap()
libmgcp: add mgcpgw client API
bridge calls via mgcpgw

mgcp: hack RAB success from nano3G: patch first RTP payload
The ip.access nano3G needs the first RTP payload's first two bytes to read hex
'e400', or it will reject the RAB assignment. Add flag
patched_first_rtp_payload to mgcp_rtp_state to detect the first RTP payload on
a stream, and overwrite its first bytes with e400. This should probably be
configurable, but seems to not harm other femto cells (as long as we patch only
the first RTP payload in each stream). Only do this when sending to the BTS
side.

Change-Id: I5b5b6a9678b458affa86800afb1ec726e66eed88

2 files changed, 113 insertions, 12 deletions

diff --git a/src/libiu/iu.c b/src/libiu/iu.c
index 932b21718..5d56a4a37 100644
--- a/src/libiu/iu.c
+++ b/src/libiu/iu.c
@@ -80,7 +80,15 @@ struct iu_rnc {
 
 void *talloc_iu_ctx;
 
-int asn1_xer_print = 1;
+/* Implement the extern asn_debug from libasn1c to indicate whether to print
+ * asn.1 debug messages (see libasn1c). */
+int asn_debug = 0;
+
+/* Implement the extern asn1_xer_print to indicate whether the ASN.1 binary
+ * code decoded and encoded during Iu communication should be logged to stderr
+ * (see asn.1 generated code in osmo-iuh). */
+int asn1_xer_print = 0;
+
 void *talloc_asn1_ctx;
 
 iu_recv_cb_t global_iu_recv_cb = NULL;
@@ -241,6 +249,25 @@ int iu_tx_sec_mode_cmd(struct ue_conn_ctx *uectx, struct gsm_auth_tuple *tp,
 	return 0;
 }
 
+int iu_tx_common_id(struct ue_conn_ctx *uectx, const char *imsi)
+{
+	struct msgb *msg;
+	struct osmo_scu_prim *prim;
+
+	LOGP(DRANAP, LOGL_INFO, "Transmitting RANAP CommonID (SUA link %p conn_id %u)\n",
+	     uectx->link, uectx->conn_id);
+
+	msg = ranap_new_msg_common_id(imsi);
+	msg->l2h = msg->data;
+	prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
+	prim->u.data.conn_id = uectx->conn_id;
+	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
+			OSMO_SCU_PRIM_N_DATA,
+			PRIM_OP_REQUEST, msg);
+	osmo_sua_user_link_down(uectx->link, &prim->oph);
+	return 0;
+}
+
 static int iu_grnc_id_parse(struct iu_grnc_id *dst,
 			    struct RANAP_GlobalRNC_ID *src)
 {
@@ -375,20 +402,35 @@ int iu_tx(struct msgb *msg_nas, uint8_t sapi)
 	return 0;
 }
 
-static int ranap_handle_co_iu_rel_req(struct ue_conn_ctx *ctx, RANAP_Iu_ReleaseRequestIEs_t *ies)
+/* Send Iu Release for the given UE connection.
+ * If cause is NULL, the standard "No remaining RAB" cause is sent, otherwise
+ * the provided cause. */
+int iu_tx_release(struct ue_conn_ctx *ctx, const struct RANAP_Cause *cause)
 {
 	struct msgb *msg;
 	struct osmo_scu_prim *prim;
+	static const struct RANAP_Cause default_cause = {
+		.present = RANAP_Cause_PR_radioNetwork,
+		.choice.radioNetwork = RANAP_CauseRadioNetwork_no_remaining_rab,
+	};
 
-	LOGP(DRANAP, LOGL_INFO, "Received Iu Release Request, Sending Release Command\n");
-	msg = ranap_new_msg_iu_rel_cmd(&ies->cause);
+	if (!cause)
+		cause = &default_cause;
+
+	msg = ranap_new_msg_iu_rel_cmd(cause);
 	msg->l2h = msg->data;
 	prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim));
 	prim->u.data.conn_id = ctx->conn_id;
 	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
 			OSMO_SCU_PRIM_N_DATA,
 			PRIM_OP_REQUEST, msg);
-	osmo_sua_user_link_down(ctx->link, &prim->oph);
+	return osmo_sua_user_link_down(ctx->link, &prim->oph);
+}
+
+static int ranap_handle_co_iu_rel_req(struct ue_conn_ctx *ctx, RANAP_Iu_ReleaseRequestIEs_t *ies)
+{
+	LOGP(DRANAP, LOGL_INFO, "Received Iu Release Request, Sending Release Command\n");
+	iu_tx_release(ctx, &ies->cause);
 	return 0;
 }
 
@@ -413,6 +455,7 @@ static int ranap_handle_co_rab_ass_resp(struct ue_conn_ctx *ctx, RANAP_RAB_Assig
 
 		ranap_free_rab_setupormodifieditemies(&setup_ies);
 	}
+	/* FIXME: handle RAB Ass failure? */
 
 	return rc;
 }
diff --git a/src/libiu/iu_vty.c b/src/libiu/iu_vty.c
index 91eed96be..73ad126ba 100644
--- a/src/libiu/iu_vty.c
+++ b/src/libiu/iu_vty.c
@@ -18,33 +18,91 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 
+#include <osmocom/core/logging.h>
 #include <osmocom/vty/command.h>
 #include <osmocom/vty/logging.h>
 
-/* Pointer to the actual asn_debug value as passed from main scopes. */
-static int *g_asn_debug_p = NULL;
+#include <openbsc/iu.h>
+
+static enum nsap_addr_enc *g_rab_assign_addr_enc = NULL;
 
 DEFUN(logging_asn_debug,
       logging_asn_debug_cmd,
       "logging asn1-debug (1|0)",
       LOGGING_STR
+      "Log ASN.1 debug messages to stderr\n"
+      "Log ASN.1 debug messages to stderr\n"
+      "Do not log ASN.1 debug messages to stderr\n")
+{
+	asn_debug = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(logging_asn_xer_print,
+      logging_asn_xer_print_cmd,
+      "logging asn1-xer-print (1|0)",
+      LOGGING_STR
       "Log human readable representations of all ASN.1 messages to stderr\n"
       "Log decoded ASN.1 messages to stderr\n"
       "Do not log decoded ASN.1 messages to stderr\n")
 {
-	if (!g_asn_debug_p) {
-		vty_out(vty, "%%ASN.1 debugging not available%s", VTY_NEWLINE);
+	asn1_xer_print = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_iu_rab_assign_addr_enc, cfg_iu_rab_assign_addr_enc_cmd,
+      "iu rab-assign-addr-enc (x213|v4raw)",
+      "Iu interface protocol options\n"
+      "Choose RAB Assignment's Transport Layer Address encoding\n"
+      "ITU-T X.213 compliant address encoding (default)\n"
+      "32bit length raw IPv4 address (for ip.access nano3G)\n")
+{
+	if (!g_rab_assign_addr_enc) {
+		vty_out(vty, "%%RAB Assignment Transport Layer Address"
+			" encoding not available%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (strcmp(argv[0], "v4raw") == 0)
+		*g_rab_assign_addr_enc = NSAP_ADDR_ENC_V4RAW;
+	else
+		*g_rab_assign_addr_enc = NSAP_ADDR_ENC_X213;
+	return CMD_SUCCESS;
+}
+
+int iu_vty_config_write(struct vty *vty, const char *indent)
+{
+	if (!g_rab_assign_addr_enc) {
+		vty_out(vty, "%%RAB Assignment Transport Layer Address"
+			" encoding not available%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	switch (*g_rab_assign_addr_enc) {
+	case NSAP_ADDR_ENC_V4RAW:
+		vty_out(vty, "%siu rab-assign-addr-enc v4raw%s", indent,
+			VTY_NEWLINE);
+		break;
+	case NSAP_ADDR_ENC_X213:
+		/* default value, no need to write anything */
+		break;
+	default:
+		LOGP(0, LOGL_ERROR, "Invalid value for"
+		     " net.iu.rab_assign_addr_enc: %d\n",
+		     *g_rab_assign_addr_enc);
 		return CMD_WARNING;
 	}
 
-	*g_asn_debug_p = atoi(argv[0]);
 	return CMD_SUCCESS;
 }
 
-void iu_vty_init(int *asn_debug_p)
+void iu_vty_init(int iu_parent_node, enum nsap_addr_enc *rab_assign_addr_enc)
 {
-	g_asn_debug_p = asn_debug_p;
+	g_rab_assign_addr_enc = rab_assign_addr_enc;
 
 	install_element(CFG_LOG_NODE, &logging_asn_debug_cmd);
+	install_element(CFG_LOG_NODE, &logging_asn_xer_print_cmd);
+	install_element(iu_parent_node, &cfg_iu_rab_assign_addr_enc_cmd);
 }