view target-utils/libcommon/hexstrings.c @ 965:2969032bdfac

fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing The only 100% safe way to pass a NULL pointer as a function argument in K&R C is to cast 0 to a pointer type; failing to do so may cause mysterious bugs (invalid stack frames or garbage in argument registers) on 64-bit machines. This issue has already been fixed in most of FC host tools, but I just found some missed spots: passing of NULL UDH to PDU encoding functions in fcup-smsend[mult] in the case of single (not concatenated) SMS.
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 01 Sep 2023 07:33:51 +0000
parents 0da2cf5a999c
children
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/*
 * The decode_hex_digits() function contained in this module
 * will be used by the XRAM and flash loading commands
 * which take SREC-like long hex string arguments.
 */

#include <ctype.h>
#include "types.h"

decode_hex_digits(str, ndigits, valp)
	char *str;
	int ndigits;
	u32 *valp;
{
	u32 accum;
	int i, c;

	accum = 0;
	for (i = 0; i < ndigits; i++) {
		c = *str++;
		if (!isxdigit(c))
			return(-1);
		accum <<= 4;
		if (isdigit(c))
			accum += c - '0';
		else if (islower(c))
			accum += c - 'a' + 10;
		else
			accum += c - 'A' + 10;
	}
	*valp = accum;
	return(0);
}