/* Test HNB */

/* (C) 2015 by Daniel Willmann <dwillmann@sysmocom.de>
 * (C) 2015 by Sysmocom s.f.m.c. GmbH
 * 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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <errno.h>
#include <signal.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/sctp.h>
#include <arpa/inet.h>

#include <osmocom/core/application.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/write_queue.h>
#include <osmocom/netif/stream.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/gsm/gsm48.h>

#include <osmocom/vty/telnet_interface.h>
#include <osmocom/vty/logging.h>
#include <osmocom/vty/command.h>

#include <osmocom/crypt/auth.h>

#include "hnb-test.h"
#include "hnb-test-layers.h"
#include "hnbap_common.h"
#include "hnbap_ies_defs.h"
#include "rua_msg_factory.h"
#include "asn1helpers.h"
#include <osmocom/ranap/iu_helpers.h>
#include "test_common.h"

#include <osmocom/ranap/ranap_msg_factory.h>

#include <osmocom/rua/RUA_RUA-PDU.h>

#include <osmocom/gsm/protocol/gsm_04_08.h>

#include <osmocom/ranap/RANAP_ProcedureCode.h>
#include <osmocom/ranap/RANAP_Criticality.h>
#include <osmocom/ranap/RANAP_DirectTransfer.h>

static void *tall_hnb_ctx;

struct hnb_test g_hnb_test = {
	.gw_addr = "127.0.0.1",
	.gw_port = IUH_DEFAULT_SCTP_PORT,
};

struct msgb *rua_new_udt(struct msgb *inmsg);

static int hnb_test_ue_de_register_tx(struct hnb_test *hnb_test)
{
	struct msgb *msg;
	int rc, imsi_len;
	uint32_t ctx_id;

	UEDe_Register_t dereg;
	UEDe_RegisterIEs_t dereg_ies;
	memset(&dereg_ies, 0, sizeof(dereg_ies));

	asn1_u24_to_bitstring(&dereg_ies.context_ID, &ctx_id, hnb_test->ctx_id);
	dereg_ies.cause.present = Cause_PR_radioNetwork;
	dereg_ies.cause.choice.radioNetwork = CauseRadioNetwork_connection_with_UE_lost;

	memset(&dereg, 0, sizeof(dereg));
	rc = hnbap_encode_uede_registeries(&dereg, &dereg_ies);

	msg = hnbap_generate_initiating_message(ProcedureCode_id_UEDe_Register,
						Criticality_ignore,
						&asn_DEF_UEDe_Register,
						&dereg);

	ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_UEDe_Register, &dereg);

	msgb_sctp_ppid(msg) = IUH_PPI_HNBAP;

	return osmo_wqueue_enqueue(&hnb_test->wqueue, msg);
}

static int hnb_test_ue_register_tx(struct hnb_test *hnb_test, const char *imsi_str)
{
	struct msgb *msg;
	int rc, imsi_len;

	char imsi_buf[16];

	UERegisterRequest_t request_out;
	UERegisterRequestIEs_t request;
	memset(&request, 0, sizeof(request));

	request.uE_Identity.present = UE_Identity_PR_iMSI;

	imsi_len = ranap_imsi_encode(imsi_buf, sizeof(imsi_buf), imsi_str);
	OCTET_STRING_fromBuf(&request.uE_Identity.choice.iMSI, imsi_buf, imsi_len);

	request.registration_Cause = Registration_Cause_normal;
	request.uE_Capabilities.access_stratum_release_indicator = Access_stratum_release_indicator_rel_6;
	request.uE_Capabilities.csg_capability = CSG_Capability_not_csg_capable;

	memset(&request_out, 0, sizeof(request_out));
	rc = hnbap_encode_ueregisterrequesties(&request_out, &request);

	msg = hnbap_generate_initiating_message(ProcedureCode_id_UERegister,
						Criticality_reject,
						&asn_DEF_UERegisterRequest,
						&request_out);

	ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_UERegisterRequest, &request_out);

	msgb_sctp_ppid(msg) = IUH_PPI_HNBAP;

	return osmo_wqueue_enqueue(&hnb_test->wqueue, msg);
}

static int hnb_test_rx_hnb_register_acc(struct hnb_test *hnb, ANY_t *in)
{
	int rc;
	HNBRegisterAcceptIEs_t accept;

	rc = hnbap_decode_hnbregisteraccepties(&accept, in);
	if (rc < 0) {
	}

	hnb->rnc_id = accept.rnc_id;
	printf("HNB Register accept with RNC ID %u\n", hnb->rnc_id);

	hnbap_free_hnbregisteraccepties(&accept);
	return 0;
}

static int hnb_test_rx_ue_register_acc(struct hnb_test *hnb, ANY_t *in)
{
	int rc;
	uint32_t ctx_id;
	UERegisterAcceptIEs_t accept;
	char imsi[16];

	rc = hnbap_decode_ueregisteraccepties(&accept, in);
	if (rc < 0) {
		return rc;
	}

	if (accept.uE_Identity.present != UE_Identity_PR_iMSI) {
		printf("Wrong type in UE register accept\n");
		return -1;
	}

	ctx_id = asn1bitstr_to_u24(&accept.context_ID);

	ranap_bcd_decode(imsi, sizeof(imsi), accept.uE_Identity.choice.iMSI.buf,
			accept.uE_Identity.choice.iMSI.size);
	printf("UE Register accept for IMSI %s, context %u\n", imsi, ctx_id);

	hnb->ctx_id = ctx_id;
	hnbap_free_ueregisteraccepties(&accept);

	return 0;
}

static struct msgb *gen_nas_id_resp()
{
	uint8_t id_resp[] = {
		GSM48_PDISC_MM,
		GSM48_MT_MM_ID_RESP,
		/* IMEISV */
		0x09, /* len */
		0x03, /* first digit (0000) + even (0) + id IMEISV (011) */
		0x31, 0x91, 0x06, 0x00, 0x28, 0x47, 0x11, /* digits */
		0xf2, /* filler (1111) + last digit (0010) */
	};

	return ranap_new_msg_dt(0, id_resp, sizeof(id_resp));
}

static struct msgb *gen_nas_tmsi_realloc_compl()
{
	uint8_t id_resp[] = {
		GSM48_PDISC_MM,
		GSM48_MT_MM_TMSI_REALL_COMPL,
	};

	return ranap_new_msg_dt(0, id_resp, sizeof(id_resp));
}

static struct msgb *gen_nas_auth_resp(uint8_t *sres)
{
	uint8_t id_resp[] = {
		GSM48_PDISC_MM,
		0x80 | GSM48_MT_MM_AUTH_RESP, /* simulate sequence nr 2 */
		0x61, 0xb5, 0x69, 0xf5 /* hardcoded SRES */
	};

	memcpy(id_resp + 2, sres, 4);

	return ranap_new_msg_dt(0, id_resp, sizeof(id_resp));
}

static int hnb_test_tx_dt(struct hnb_test *hnb, struct msgb *txm)
{
	struct hnbtest_chan *chan;
	struct msgb *rua;

	chan = hnb->cs.chan;
	if (!chan) {
		printf("hnb_test_nas_tx_tmsi_realloc_compl(): No CS channel established yet.\n");
		return -1;
	}

	rua = rua_new_dt(chan->is_ps, chan->conn_id, txm);
	osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);
	return 0;
}

static struct tlv_parsed *parse_mm(struct gsm48_hdr *gh, int len)
{
	static struct tlv_parsed tp;
	int parse_res;

	len -= (const char *)&gh->data[0] - (const char *)gh;

	OSMO_ASSERT(gsm48_hdr_pdisc(gh) == GSM48_PDISC_MM);

	parse_res = tlv_parse(&tp, &gsm48_mm_att_tlvdef, &gh->data[0], len, 0, 0);
	if (parse_res <= 0) {
		uint8_t msg_type = gsm48_hdr_msg_type(gh);
		printf("Error parsing MM message 0x%hhx: %d\n", msg_type, parse_res);
		return NULL;
	}

	return &tp;
}

int hnb_test_nas_rx_lu_accept(struct gsm48_hdr *gh, int len, int *sent_tmsi)
{
	printf(" :D Location Update Accept :D\n");
	struct gsm48_loc_area_id *lai;

	lai = (struct gsm48_loc_area_id *)&gh->data[0];

	uint16_t mcc, mnc, lac;
	gsm48_decode_lai(lai, &mcc, &mnc, &lac);
	printf("LU: mcc %hd  mnc %hd  lac %hd\n",
	       mcc, mnc, lac);

	struct tlv_parsed tp;
	int parse_res;

	len -= (const char *)&gh->data[0] - (const char *)gh;
	parse_res = tlv_parse(&tp, &gsm48_mm_att_tlvdef, &gh->data[0], len, 0, 0);
	if (parse_res <= 0) {
		printf("Error parsing Location Update Accept message: %d\n", parse_res);
		return -1;
	}

	if (TLVP_PRESENT(&tp, GSM48_IE_MOBILE_ID)) {
		uint8_t type = TLVP_VAL(&tp, GSM48_IE_NAME_SHORT)[0] & 0x0f;
		if (type == GSM_MI_TYPE_TMSI)
			*sent_tmsi = 1;
		else *sent_tmsi = 0;
	}
	return 0;
}

void hnb_test_nas_rx_mm_info(struct gsm48_hdr *gh, int len)
{
	printf(" :) MM Info :)\n");
	struct tlv_parsed *tp = parse_mm(gh, len);
	if (!tp)
		return;

	if (TLVP_PRESENT(tp, GSM48_IE_NAME_SHORT)) {
		char name[128] = {0};
		gsm_7bit_decode_n(name, 127,
				  TLVP_VAL(tp, GSM48_IE_NAME_SHORT)+1,
				  (TLVP_LEN(tp, GSM48_IE_NAME_SHORT)-1)*8/7);
		printf("Info: Short Network Name: %s\n", name);
	}

	if (TLVP_PRESENT(tp, GSM48_IE_NAME_LONG)) {
		char name[128] = {0};
		gsm_7bit_decode_n(name, 127,
				  TLVP_VAL(tp, GSM48_IE_NAME_LONG)+1,
				  (TLVP_LEN(tp, GSM48_IE_NAME_LONG)-1)*8/7);
		printf("Info: Long Network Name: %s\n", name);
	}
}

static int hnb_test_nas_rx_auth_req(struct hnb_test *hnb, struct gsm48_hdr *gh,
				    int len)
{
	struct gsm48_auth_req *ar;
	int parse_res;

	len -= (const char *)&gh->data[0] - (const char *)gh;

	if (len < sizeof(*ar)) {
		printf("GSM48 Auth Req does not fit.\n");
		return;
	}

	printf(" :) Authentication Request :)\n");

	ar = (struct gsm48_auth_req*) &gh->data[0];
	int seq = ar->key_seq;

	/* Generate SRES from *HARDCODED* Ki for Iuh testing */
	struct osmo_auth_vector vec;
	/* Ki 000102030405060708090a0b0c0d0e0f */
	struct osmo_sub_auth_data auth = {
		.type	= OSMO_AUTH_TYPE_GSM,
		.algo	= OSMO_AUTH_ALG_COMP128v1,
		.u.gsm.ki = {
			0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
			0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d,
			0x0e, 0x0f
		},
	};

	memset(&vec, 0, sizeof(vec));
	osmo_auth_gen_vec(&vec, &auth, ar->rand);

	printf("seq %d rand %s",
	       seq, osmo_hexdump(ar->rand, sizeof(ar->rand)));
	printf(" --> sres %s\n",
	       osmo_hexdump(vec.sres, 4));

	return hnb_test_tx_dt(hnb, gen_nas_auth_resp(vec.sres));
}

static int hnb_test_nas_rx_mm(struct hnb_test *hnb, struct gsm48_hdr *gh, int len)
{
	struct hnbtest_chan *chan;

	chan = hnb->cs.chan;
	if (!chan) {
		printf("hnb_test_nas_rx_mm(): No CS channel established yet.\n");
		return -1;
	}

	OSMO_ASSERT(!chan->is_ps);

	uint8_t msg_type = gsm48_hdr_msg_type(gh);
	int sent_tmsi;

	switch (msg_type) {
	case GSM48_MT_MM_ID_REQ:
		return hnb_test_tx_dt(hnb, gen_nas_id_resp());

	case GSM48_MT_MM_LOC_UPD_ACCEPT:
		if (hnb_test_nas_rx_lu_accept(gh, len, &sent_tmsi))
			return -1;
		if (sent_tmsi)
			return hnb_test_tx_dt(hnb, gen_nas_tmsi_realloc_compl());
		else
			return 0;

	case GSM48_MT_MM_LOC_UPD_REJECT:
		printf("Received Location Update Reject\n");
		return 0;

	case GSM48_MT_MM_INFO:
		hnb_test_nas_rx_mm_info(gh, len);
		return 0;

	case GSM48_MT_MM_AUTH_REQ:
		return hnb_test_nas_rx_auth_req(hnb, gh, len);

	default:
		printf("04.08 message type not handled by hnb-test: 0x%x\n",
		       msg_type);
		return 0;
	}

}

void hnb_test_nas_rx_dtap(struct hnb_test *hnb, void *data, int len)
{
	int rc;
	printf("got %d bytes: %s\n", len, osmo_hexdump(data, len));

	// nas_pdu == '05 08 12' ==> IMEI Identity request
	//            '05 04 0d' ==> LU reject

	struct gsm48_hdr *gh = data;
	if (len < sizeof(*gh)) {
		printf("hnb_test_nas_rx_dtap(): NAS PDU is too short: %d. Ignoring.\n",
		       len);
		return;
	}
	uint8_t pdisc = gsm48_hdr_pdisc(gh);

	switch (pdisc) {
	case GSM48_PDISC_MM:
		rc = hnb_test_nas_rx_mm(hnb, gh, len);
		if (rc != 0)
			printf("Error receiving MM message: %d\n", rc);
		return;
	default:
		printf("04.08 discriminator not handled by hnb-test: %d\n",
		       pdisc);
		return;
	}
}

int hnb_test_hnbap_rx(struct hnb_test *hnb, struct msgb *msg)
{
	HNBAP_PDU_t _pdu, *pdu = &_pdu;
	asn_dec_rval_t dec_ret;
	int rc;

	memset(pdu, 0, sizeof(*pdu));
	dec_ret = aper_decode(NULL, &asn_DEF_HNBAP_PDU, (void **) &pdu,
			      msg->data, msgb_length(msg), 0, 0);
	if (dec_ret.code != RC_OK) {
		LOGP(DMAIN, LOGL_ERROR, "Error in ASN.1 decode\n");
		return rc;
	}

	if (pdu->present != HNBAP_PDU_PR_successfulOutcome) {
		printf("Unexpected HNBAP message received\n");
	}

	switch (pdu->choice.successfulOutcome.procedureCode) {
	case ProcedureCode_id_HNBRegister:
		/* Get HNB id and send UE Register request */
		rc = hnb_test_rx_hnb_register_acc(hnb, &pdu->choice.successfulOutcome.value);
		break;
	case ProcedureCode_id_UERegister:
		rc = hnb_test_rx_ue_register_acc(hnb, &pdu->choice.successfulOutcome.value);
		break;
	default:
		break;
	}

	return rc;
}

extern void direct_transfer_nas_pdu_print(ANY_t *in);

int hnb_test_rua_rx(struct hnb_test *hnb, struct msgb *msg)
{
	RUA_RUA_PDU_t _pdu, *pdu = &_pdu;
	asn_dec_rval_t dec_ret;
	int rc;

	memset(pdu, 0, sizeof(*pdu));
	dec_ret = aper_decode(NULL, &asn_DEF_RUA_RUA_PDU, (void **) &pdu,
			      msg->data, msgb_length(msg), 0, 0);
	if (dec_ret.code != RC_OK) {
		LOGP(DMAIN, LOGL_ERROR, "Error in ASN.1 decode\n");
		return rc;
	}

	switch (pdu->present) {
	case RUA_RUA_PDU_PR_successfulOutcome:
		printf("RUA_RUA_PDU_PR_successfulOutcome\n");
		break;
	case RUA_RUA_PDU_PR_initiatingMessage:
		printf("RUA_RUA_PDU_PR_initiatingMessage\n");
		break;
	case RUA_RUA_PDU_PR_NOTHING:
		printf("RUA_RUA_PDU_PR_NOTHING\n");
		break;
	case RUA_RUA_PDU_PR_unsuccessfulOutcome:
		printf("RUA_RUA_PDU_PR_unsuccessfulOutcome\n");
		break;
	default:
		printf("Unexpected RUA message received\n");
		break;
	}

	switch (pdu->choice.successfulOutcome.procedureCode) {
	case RUA_ProcedureCode_id_ConnectionlessTransfer:
		printf("RUA rx Connectionless Transfer\n");
		break;
	case RUA_ProcedureCode_id_Connect:
		printf("RUA rx Connect\n");
		break;
	case RUA_ProcedureCode_id_DirectTransfer:
		printf("RUA rx DirectTransfer\n");
		hnb_test_rua_dt_handle(hnb, &pdu->choice.successfulOutcome.value);
		break;
	case RUA_ProcedureCode_id_Disconnect:
		printf("RUA rx Disconnect\n");
		break;
	case RUA_ProcedureCode_id_ErrorIndication:
		printf("RUA rx ErrorIndication\n");
		break;
	case RUA_ProcedureCode_id_privateMessage:
		printf("RUA rx privateMessage\n");
		break;
	default:
		printf("RUA rx unknown message\n");
		break;
	}

	return rc;
}

static int hnb_read_cb(struct osmo_fd *fd)
{
	struct hnb_test *hnb_test = fd->data;
	struct sctp_sndrcvinfo sinfo;
	struct msgb *msg = msgb_alloc(IUH_MSGB_SIZE, "Iuh rx");
	int flags = 0;
	int rc;

	if (!msg)
		return -ENOMEM;

	rc = sctp_recvmsg(fd->fd, msgb_data(msg), msgb_tailroom(msg),
			  NULL, NULL, &sinfo, &flags);
	if (rc < 0) {
		LOGP(DMAIN, LOGL_ERROR, "Error during sctp_recvmsg()\n");
		/* FIXME: clean up after disappeared HNB */
		close(fd->fd);
		osmo_fd_unregister(fd);
		return rc;
	} else if (rc == 0) {
		LOGP(DMAIN, LOGL_INFO, "Connection to HNB closed\n");
		close(fd->fd);
		osmo_fd_unregister(fd);
		fd->fd = -1;

		return -1;
	} else {
		msgb_put(msg, rc);
	}

	if (flags & MSG_NOTIFICATION) {
		LOGP(DMAIN, LOGL_DEBUG, "Ignoring SCTP notification\n");
		msgb_free(msg);
		return 0;
	}

	sinfo.sinfo_ppid = ntohl(sinfo.sinfo_ppid);

	switch (sinfo.sinfo_ppid) {
	case IUH_PPI_HNBAP:
		printf("HNBAP message received\n");
		rc = hnb_test_hnbap_rx(hnb_test, msg);
		break;
	case IUH_PPI_RUA:
		printf("RUA message received\n");
		rc = hnb_test_rua_rx(hnb_test, msg);
		break;
	case IUH_PPI_SABP:
	case IUH_PPI_RNA:
	case IUH_PPI_PUA:
		LOGP(DMAIN, LOGL_ERROR, "Unimplemented SCTP PPID=%u received\n",
		     sinfo.sinfo_ppid);
		rc = 0;
		break;
	default:
		LOGP(DMAIN, LOGL_ERROR, "Unknown SCTP PPID=%u received\n",
		     sinfo.sinfo_ppid);
		rc = 0;
		break;
	}

	msgb_free(msg);
	return rc;
}

static int hnb_write_cb(struct osmo_fd *fd, struct msgb *msg)
{
	struct hnb_test *ctx = fd->data;
	struct sctp_sndrcvinfo sinfo = {
		.sinfo_ppid = htonl(msgb_sctp_ppid(msg)),
		.sinfo_stream = 0,
	};
	int rc;

	printf("Sending: %s\n", osmo_hexdump(msgb_data(msg), msgb_length(msg)));
	rc = sctp_send(fd->fd, msgb_data(msg), msgb_length(msg),
			&sinfo, 0);
	/* we don't need to msgb_free(), write_queue does this for us */
	return rc;
}

static void hnb_send_register_req(struct hnb_test *hnb_test)
{
	HNBRegisterRequest_t request_out;
	struct msgb *msg;
	int rc;
	uint16_t lac, sac;
	uint8_t rac;
	uint32_t cid;
	uint8_t plmn[] = {0x09, 0xf1, 0x99};
	char identity[50] = "ATestHNB@";

	HNBRegisterRequestIEs_t request;
	memset(&request, 0, sizeof(request));

	lac = 0xc0fe;
	sac = 0xabab;
	rac = 0x42;
	cid = 0xadceaab;

	asn1_u16_to_str(&request.lac, &lac, lac);
	asn1_u16_to_str(&request.sac, &sac, sac);
	asn1_u8_to_str(&request.rac, &rac, rac);
	asn1_u28_to_bitstring(&request.cellIdentity, &cid, cid);

	request.hnB_Identity.hNB_Identity_Info.buf = identity;
	request.hnB_Identity.hNB_Identity_Info.size = strlen(identity);

	request.plmNidentity.buf = plmn;
	request.plmNidentity.size = 3;


	memset(&request_out, 0, sizeof(request_out));
	rc = hnbap_encode_hnbregisterrequesties(&request_out, &request);
	if (rc < 0) {
		printf("Could not encode HNB register request IEs\n");
	}

	msg = hnbap_generate_initiating_message(ProcedureCode_id_HNBRegister,
						Criticality_reject,
						&asn_DEF_HNBRegisterRequest,
						&request_out);


	msgb_sctp_ppid(msg) = IUH_PPI_HNBAP;

	osmo_wqueue_enqueue(&hnb_test->wqueue, msg);
}

static void hnb_send_deregister_req(struct hnb_test *hnb_test)
{
	struct msgb *msg;
	int rc;

	HNBDe_RegisterIEs_t request;
	memset(&request, 0, sizeof(request));

	request.cause.present = Cause_PR_misc;
	request.cause.choice.misc = CauseMisc_o_and_m_intervention;

	HNBDe_Register_t request_out;
	memset(&request_out, 0, sizeof(request_out));
	rc = hnbap_encode_hnbde_registeries(&request_out, &request);
	if (rc < 0) {
		printf("Could not encode HNB deregister request IEs\n");
	}

	msg = hnbap_generate_initiating_message(ProcedureCode_id_HNBDe_Register,
						Criticality_reject,
						&asn_DEF_HNBDe_Register,
						&request_out);

	msgb_sctp_ppid(msg) = IUH_PPI_HNBAP;

	osmo_wqueue_enqueue(&hnb_test->wqueue, msg);
}


static const struct log_info_cat log_cat[] = {
	[DMAIN] = {
		.name = "DMAIN", .loglevel = LOGL_INFO, .enabled = 1,
		.color = "",
		.description = "Main program",
	},
	[DHNBAP] = {
		.name = "DHNBAP", .loglevel = LOGL_DEBUG, .enabled = 1,
		.color = "",
		.description = "Home Node B Application Part",
	},
};

static const struct log_info hnb_test_log_info = {
	.cat = log_cat,
	.num_cat = ARRAY_SIZE(log_cat),
};

static struct vty_app_info vty_info = {
	.name		= "OsmoHNB-Test",
	.version	= "0",
};

static int sctp_sock_init(int fd)
{
	struct sctp_event_subscribe event;
	int rc;

	/* subscribe for all events */
	memset((uint8_t *)&event, 1, sizeof(event));
	rc = setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS,
			&event, sizeof(event));

	return rc;
}

#define HNBAP_STR	"HNBAP related commands\n"
#define HNB_STR		"HomeNodeB commands\n"
#define UE_STR		"User Equipment commands\n"
#define RANAP_STR	"RANAP related commands\n"
#define CSPS_STR	"Circuit Switched\n" "Packet Switched\n"

DEFUN(hnb_register, hnb_register_cmd,
	"hnbap hnb register", HNBAP_STR HNB_STR "Send HNB-REGISTER REQUEST")
{
	hnb_send_register_req(&g_hnb_test);

	return CMD_SUCCESS;
}

DEFUN(hnb_deregister, hnb_deregister_cmd,
	"hnbap hnb deregister", HNBAP_STR HNB_STR "Send HNB-DEREGISTER REQUEST")
{
	hnb_send_deregister_req(&g_hnb_test);

	return CMD_SUCCESS;
}

DEFUN(ue_register, ue_register_cmd,
	"hnbap ue register IMSI", HNBAP_STR UE_STR "Send UE-REGISTER REQUEST")
{
	hnb_test_ue_register_tx(&g_hnb_test, argv[0]);

	return CMD_SUCCESS;
}

DEFUN(asn_dbg, asn_dbg_cmd,
	"asn-debug (1|0)", "Enable or disabel libasn1c debugging")
{
	asn_debug = atoi(argv[0]);

	return CMD_SUCCESS;
}

DEFUN(ranap_reset, ranap_reset_cmd,
	"ranap reset (cs|ps)", RANAP_STR "Send RANAP RESET\n" CSPS_STR)
{
	int is_ps = 0;
	struct msgb *msg, *rua;

	RANAP_Cause_t cause = {
		.present = RANAP_Cause_PR_transmissionNetwork,
		.choice.transmissionNetwork = RANAP_CauseTransmissionNetwork_signalling_transport_resource_failure,
	};

	if (!strcmp(argv[0], "ps"))
		is_ps = 1;

	msg = ranap_new_msg_reset(is_ps, &cause);
	rua = rua_new_udt(msg);
	//msgb_free(msg);
	osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

	return CMD_SUCCESS;
}


enum my_vty_nodes {
	CHAN_NODE = _LAST_OSMOVTY_NODE,
};

static struct cmd_node chan_node = {
	CHAN_NODE,
	"%s(chan)> ",
	1,
};


static struct msgb *gen_initue_lu(int is_ps, uint32_t conn_id, const char *imsi)
{
	uint8_t lu[] = { GSM48_PDISC_MM, GSM48_MT_MM_LOC_UPD_REQUEST,
		         0x70, 0x62, 0xf2, 0x30, 0xff, 0xf3, 0x57,
		/*	 len, IMSI/type, IMSI-------------------------------- */
			 0x08, 0x29, 0x26, 0x24, 0x10, 0x32, 0x54, 0x76, 0x98,
			 0x33, 0x03, 0x57, 0x18 , 0xb2 };
	uint8_t plmn_id[] = { 0x09, 0x01, 0x99 };
	RANAP_GlobalRNC_ID_t rnc_id = {
		.rNC_ID = 23,
		.pLMNidentity.buf = plmn_id,
		.pLMNidentity.size = sizeof(plmn_id),
	};

	/* FIXME: patch imsi */
	/* Note: the Mobile Identitiy IE's IMSI data has the identity type and
	 * an even/odd indicator bit encoded in the first octet. So the first
	 * octet looks like this:
	 *
	 *   8  7  6  5 | 4        | 3 2 1
	 *   IMSI-digit | even/odd | type
	 *
	 * followed by the remaining IMSI digits.
	 * If digit count is even (bit 4 == 0), that first high-nibble is 0xf.
	 * (derived from Iu pcap Location Update Request msg and TS 25.413)
	 *
	 * TODO I'm only 90% sure about this
	 */

	return ranap_new_msg_initial_ue(conn_id, is_ps, &rnc_id, lu, sizeof(lu));
}

DEFUN(chan, chan_cmd,
	"channel (cs|ps) lu imsi IMSI",
	"Open a new Signalling Connection\n"
	"To Circuit-Switched CN\n"
	"To Packet-Switched CN\n"
	"Performing a Location Update\n"
	)
{
	struct hnbtest_chan *chan;
	struct msgb *msg, *rua;
	static uint16_t conn_id = 42;

	chan = talloc_zero(tall_hnb_ctx, struct hnbtest_chan);
	if (!strcmp(argv[0], "ps"))
		chan->is_ps = 1;
	chan->imsi = talloc_strdup(chan, argv[1]);
	chan->conn_id = conn_id;
	conn_id++;

	msg = gen_initue_lu(chan->is_ps, chan->conn_id, chan->imsi);
	rua = rua_new_conn(chan->is_ps, chan->conn_id, msg);

	osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

	vty->index = chan;
	vty->node = CHAN_NODE;

	if (!chan->is_ps)
		g_hnb_test.cs.chan = chan;


	return CMD_SUCCESS;
}

static void hnbtest_vty_init(void)
{
	install_element_ve(&asn_dbg_cmd);
	install_element_ve(&hnb_register_cmd);
	install_element_ve(&hnb_deregister_cmd);
	install_element_ve(&ue_register_cmd);
	install_element_ve(&ranap_reset_cmd);
	install_element_ve(&chan_cmd);

	install_node(&chan_node, NULL);
	vty_install_default(CHAN_NODE);
}

static void handle_options(int argc, char **argv)
{
	while (1) {
		int idx = 0, c;
		static const struct option long_options[] = {
			{ "ues", 1, 0, 'u' },
			{ "gw-addr", 1, 0, 'g' },
			{ 0, 0, 0, 0 },
		};

		c = getopt_long(argc, argv, "u:g:", long_options, &idx);

		if (c == -1)
			break;

		switch (c) {
		case 'u':
			g_hnb_test.ues = atoi(optarg);
			break;
		case 'g':
			g_hnb_test.gw_addr = optarg;
			break;
		}
	}
}

int main(int argc, char **argv)
{
	int rc;

	test_common_init();

	tall_hnb_ctx = talloc_named_const(NULL, 0, "hnb_context");

	vty_init(&vty_info);
	hnbtest_vty_init();

	printf("VTY at %s %d\n", vty_get_bind_addr(), 2324);
	rc = telnet_init_dynif(NULL, NULL, vty_get_bind_addr(), 2324);
	if (rc < 0) {
		perror("Error binding VTY port");
		exit(1);
	}

	handle_options(argc, argv);

	osmo_wqueue_init(&g_hnb_test.wqueue, 16);
	g_hnb_test.wqueue.bfd.data = &g_hnb_test;
	g_hnb_test.wqueue.read_cb = hnb_read_cb;
	g_hnb_test.wqueue.write_cb = hnb_write_cb;

	rc = osmo_sock_init_ofd(&g_hnb_test.wqueue.bfd, AF_INET, SOCK_STREAM,
			   IPPROTO_SCTP, g_hnb_test.gw_addr,
			   g_hnb_test.gw_port, OSMO_SOCK_F_CONNECT);
	if (rc < 0) {
		perror("Error connecting to Iuh port");
		exit(1);
	}
	sctp_sock_init(g_hnb_test.wqueue.bfd.fd);

#if 0
	/* some hard-coded message generation.  Doesn't make sense from
	 * a protocol point of view but enables to look at the encoded
	 * results in wireshark for manual verification */
	{
		struct msgb *msg, *rua;
		const uint8_t nas[] = { 0, 1, 2, 3 };
		const uint8_t ik[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };

		msg = ranap_new_msg_dt(0, nas, sizeof(nas));
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

		msg = ranap_new_msg_sec_mod_cmd(ik, ik);
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

		msg = ranap_new_msg_iu_rel_cmd()
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

		msg = ranap_new_msg_paging_cmd("901990123456789", NULL, 0, 0);
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

		msg = ranap_new_msg_rab_assign_voice(1, 0x01020304, 0x1020);
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);

		msg = ranap_new_msg_rab_assign_data(2, 0x01020304, 0x11223344);
		rua = rua_new_udt(msg);
		osmo_wqueue_enqueue(&g_hnb_test.wqueue, rua);
	}
#endif

	while (1) {
		rc = osmo_select_main(0);
		if (rc < 0)
			exit(3);
	}

	/* not reached */
	exit(0);
}