/*
 * This library module implements the function for converting UTF-8 input
 * to UCS-2 in outgoing SMS composition.
 */

#include <sys/types.h>

utf8_to_ucs2(inbuf, outbuf, outmax, outlenp)
	u_char *inbuf;
	u_short *outbuf;
	unsigned outmax, *outlenp;
{
	u_char *ip = inbuf;
	u_short *op = outbuf;
	unsigned outcnt = 0, c, n, uni;

	while (c = *ip++) {
		if (c < 0x80) {
			uni = c;
			goto gotuni;
		}
		if (c < 0xC0 || c > 0xEF)
			return(-1);
		uni = c & 0x1F;
		if (c >= 0xE0)
			n = 2;
		else
			n = 1;
		for (; n; n--) {
			c = *ip++;
			if (c < 0x80 || c > 0xBF)
				return(-1);
			uni <<= 6;
			uni |= c & 0x3F;
		}
gotuni:		if (outcnt >= outmax)
			return(-2);
		*op++ = uni;
		outcnt++;
	}
	*outlenp = outcnt;
	return(0);
}