sabp: Generate C/H files for SABP; create libosmo-sabp

This uses the (modified) Osmocom asn1c on the (modified) SABP ASN.1
syntax to generate C code + header files for SABP parsing/encoding.

It also adds some helper code for message encoding and decoding as well
as a new libosmo-sabp shared library which can be used by programs to
implement SABP related functionality.

Change-Id: Ib9580d1af96354398da4c9f97b28a0e23d56e275
diff --git a/src/sabp_common.c b/src/sabp_common.c
new file mode 100644
index 0000000..cdb0e32
--- /dev/null
+++ b/src/sabp_common.c
@@ -0,0 +1,215 @@
+/* common SABP code */
+
+/* (C) 2015 by Harald Welte <laforge@gnumonks.org>
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdint.h>
+
+#include <osmocom/core/msgb.h>
+
+#include <osmocom/sabp/sabp_common.h>
+#include <asn1c/asn1helpers.h>
+
+extern int asn1_xer_print;
+int _sabp_DSABP = 0;
+#define DSABP _sabp_DSABP
+
+const struct value_string sabp_presence_vals[] = {
+	{ SABP_SABP_PDU_PR_initiatingMessage,	"Initiating" },
+	{ SABP_SABP_PDU_PR_successfulOutcome,	"Successful Outcome" },
+	{ SABP_SABP_PDU_PR_unsuccessfulOutcome,	"Unsuccessful Outcome" },
+	{ 0, NULL }
+};
+
+const struct value_string sabp_procedure_code_vals[] = {
+	{ SABP_ProcedureCode_id_Write_Replace, "Write-Replace" },
+	{ SABP_ProcedureCode_id_Kill, "Kill" },
+	{ SABP_ProcedureCode_id_Load_Status_Enquiry, "Load-Status-Enquiry" },
+	{ SABP_ProcedureCode_id_Message_Status_Query, "Message-Status-Query" },
+	{ SABP_ProcedureCode_id_Restart_Indication, "Restart-Indication" },
+	{ SABP_ProcedureCode_id_Reset, "Reset" },
+	{ SABP_ProcedureCode_id_Failure_Indication, "Failure-Indication" },
+	{ SABP_ProcedureCode_id_Error_Indication, "Error-Indication" },
+	{ 0, NULL }
+};
+
+const struct value_string sabp_cause_vals[] = {
+	{ SABP_Cause_parameter_not_recognised, "Parameter not recognized" },
+	{ SABP_Cause_parameter_value_invalid, "Parameter value invalid" },
+	{ SABP_Cause_valid_CN_message_not_identified, "Valid CN message not identified" },
+	{ SABP_Cause_service_area_identity_not_valid, "Service Area Identity not valid" },
+	{ SABP_Cause_unrecognised_message, "Unrecognised message" },
+	{ SABP_Cause_missing_mandatory_element, "Missing mandatory element" },
+	{ SABP_Cause_rNC_capacity_exceeded, "RNC capacity exceeded" },
+	{ SABP_Cause_rNC_memory_exceeded, "RNC memory exceeded" },
+	{ SABP_Cause_service_area_broadcast_not_supported, "Service Area Broadcast not supported" },
+	{ SABP_Cause_service_area_broadcast_not_operational, "Service Area Broadcast not operational" },
+	{ SABP_Cause_message_reference_already_used, "Message Reference already used" },
+	{ SABP_Cause_unspecifed_error, "Unspecified Error" },
+	{ SABP_Cause_transfer_syntax_error, "Transfer Syntax Error" },
+	{ SABP_Cause_semantic_error, "Semantic Error" },
+	{ SABP_Cause_message_not_compatible_with_receiver_state,
+						"Message not compatible with receiver state" },
+	{ SABP_Cause_abstract_syntax_error_reject, "Abstract Syntax Error - Reject" },
+	{ SABP_Cause_abstract_syntax_error_ignore_and_notify,
+						"Abstract Syntax Error - Ignore and Notify" },
+	{ SABP_Cause_abstract_syntax_error_falsely_constructed_message,
+						"Abstract Syntax Error - Falsely constructed message" },
+	{ 0, NULL }
+};
+
+static struct msgb *sabp_msgb_alloc(void)
+{
+	return msgb_alloc_headroom(1024+512, 512, "SABP Tx");
+}
+
+static struct msgb *_sabp_gen_msg(SABP_SABP_PDU_t *pdu)
+{
+	struct msgb *msg = sabp_msgb_alloc();
+	asn_enc_rval_t rval;
+
+	if (!msg)
+		return NULL;
+
+	rval = aper_encode_to_buffer(&asn_DEF_SABP_SABP_PDU, pdu,
+				       msg->data, msgb_tailroom(msg));
+	if (rval.encoded < 0) {
+		LOGP(DSABP, LOGL_ERROR, "Error encoding type: %s\n",
+				rval.failed_type->name);
+
+	}
+
+	msgb_put(msg, rval.encoded/8);
+
+	return msg;
+}
+
+struct msgb *sabp_generate_initiating_message(e_SABP_ProcedureCode procedureCode,
+					  SABP_Criticality_t criticality,
+					  asn_TYPE_descriptor_t *td, void *sptr)
+{
+	SABP_SABP_PDU_t pdu;
+	struct msgb *msg;
+	int rc;
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	pdu.present = SABP_SABP_PDU_PR_initiatingMessage;
+	pdu.choice.initiatingMessage.procedureCode = procedureCode;
+	pdu.choice.initiatingMessage.criticality = criticality;
+	rc = ANY_fromType_aper(&pdu.choice.initiatingMessage.value, td, sptr);
+	if (rc < 0) {
+		LOGP(DSABP, LOGL_ERROR, "Error in ANY_fromType_aper\n");
+		return NULL;
+	}
+
+	msg = _sabp_gen_msg(&pdu);
+	ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_SABP_SABP_PDU, &pdu);
+
+	return msg;
+}
+
+struct msgb *sabp_generate_successful_outcome(
+					   e_SABP_ProcedureCode procedureCode,
+					   SABP_Criticality_t criticality,
+					   asn_TYPE_descriptor_t * td,
+					   void *sptr)
+{
+	SABP_SABP_PDU_t pdu;
+	struct msgb *msg;
+	int rc;
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	pdu.present = SABP_SABP_PDU_PR_successfulOutcome;
+	pdu.choice.successfulOutcome.procedureCode = procedureCode;
+	pdu.choice.successfulOutcome.criticality = criticality;
+	rc = ANY_fromType_aper(&pdu.choice.successfulOutcome.value, td, sptr);
+	if (rc < 0) {
+		LOGP(DSABP, LOGL_ERROR, "Error in ANY_fromType_aper\n");
+		return NULL;
+	}
+
+	msg = _sabp_gen_msg(&pdu);
+	ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_SABP_SABP_PDU, &pdu);
+
+	return msg;
+}
+
+struct msgb *sabp_generate_unsuccessful_outcome(
+					e_SABP_ProcedureCode procedureCode,
+					SABP_Criticality_t criticality,
+					asn_TYPE_descriptor_t * td,
+					void *sptr)
+{
+	SABP_SABP_PDU_t pdu;
+	struct msgb *msg;
+	int rc;
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	pdu.present = SABP_SABP_PDU_PR_unsuccessfulOutcome;
+	pdu.choice.unsuccessfulOutcome.procedureCode = procedureCode;
+	pdu.choice.unsuccessfulOutcome.criticality = criticality;
+	rc = ANY_fromType_aper(&pdu.choice.unsuccessfulOutcome.value, td, sptr);
+	if (rc < 0) {
+		LOGP(DSABP, LOGL_ERROR, "Error in ANY_fromType_aper\n");
+		return NULL;
+	}
+
+	msg = _sabp_gen_msg(&pdu);
+	ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_SABP_SABP_PDU, &pdu);
+
+	return msg;
+}
+
+SABP_IE_t *sabp_new_ie(SABP_ProtocolIE_ID_t id,
+			SABP_Criticality_t criticality,
+			asn_TYPE_descriptor_t * type, void *sptr)
+{
+	SABP_IE_t *buff;
+	int rc;
+
+	if ((buff = CALLOC(1, sizeof(*buff))) == NULL) {
+		// Possible error on malloc
+		return NULL;
+	}
+
+	buff->id = id;
+	buff->criticality = criticality;
+
+	rc = ANY_fromType_aper(&buff->value, type, sptr);
+	if (rc < 0) {
+		LOGP(DSABP, LOGL_ERROR, "Error in ANY_fromType_aper\n");
+		FREEMEM(buff);
+		return NULL;
+	}
+
+	if (asn1_xer_print)
+		if (xer_fprint(stdout, &asn_DEF_SABP_IE, buff) < 0) {
+			FREEMEM(buff);
+			return NULL;
+		}
+
+	return buff;
+}
+
+void sabp_set_log_area(int log_area)
+{
+	_sabp_DSABP = log_area;
+}