/*
 * This C module is the main for proto-smsc-sendmt, a command line utility
 * that constructs an MT-forwardSM.req GSUP message and shoots it over to
 * proto-smsc-daemon for feeding to OsmoHLR.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <ctype.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

#include <osmocom/core/msgb.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/socket.h>

#include <osmocom/gsm/gsup.h>

extern void parse_smsc_addr_arg(const char *arg);
extern void encode_smsc_addr(struct osmo_gsup_message *gmsg);
extern int grok_imsi_user_arg(const char *arg, char *dest);
extern void read_pdu_from_stdin(void);

extern uint8_t tpdu_buf[];
extern unsigned tpdu_len;

static const uint8_t sm_rp_mr = 0xFF;

int main(int argc, char **argv)
{
	struct osmo_gsup_message gmsg;
	struct msgb *msgb;
	int rc, sock;

	if (argc != 4) {
		fprintf(stderr, "usage: %s smsc-addr imsi socket-path\n",
			argv[0]);
		exit(1);
	}
	parse_smsc_addr_arg(argv[1]);
	memset(&gmsg, 0, sizeof(gmsg));
	rc = grok_imsi_user_arg(argv[2], gmsg.imsi);
	if (rc < 0) {
		fprintf(stderr, "error: invalid IMSI argument\n");
		exit(1);
	}
	read_pdu_from_stdin();

	/* fill out the rest of GSUP msg */
	gmsg.message_type = OSMO_GSUP_MSGT_MT_FORWARD_SM_REQUEST;
	gmsg.message_class = OSMO_GSUP_MESSAGE_CLASS_SMS;
	gmsg.sm_rp_mr = &sm_rp_mr;
	gmsg.sm_rp_da_type = OSMO_GSUP_SMS_SM_RP_ODA_NULL;
	gmsg.sm_rp_oa_type = OSMO_GSUP_SMS_SM_RP_ODA_SMSC_ADDR;
	encode_smsc_addr(&gmsg);
	gmsg.sm_rp_ui = tpdu_buf;
	gmsg.sm_rp_ui_len = tpdu_len;

	/* pack it into an msgb */
	msgb = msgb_alloc_headroom(4000, 64, "sendmt");
	if (!msgb) {
		fprintf(stderr, "error: unable to allocate msgb\n");
		exit(1);
	}
	rc = osmo_gsup_encode(msgb, &gmsg);
	if (rc < 0) {
		fprintf(stderr, "error: osmo_gsup_encode() failed\n");
		exit(1);
	}

	/* send it off via UNIX socket */
	sock = osmo_sock_unix_init(SOCK_DGRAM, 0, argv[3], OSMO_SOCK_F_CONNECT);
	if (sock < 0) {
		fprintf(stderr, "error connecting to %s\n", argv[3]);
		exit(1);
	}
	rc = send(sock, msgb->data, msgb->len, 0);
	if (rc < 0) {
		perror("sending dgram on socket");
		exit(1);
	}
	exit(0);
}