FreeCalypso > hg > freecalypso-tools
view target-utils/libcommon/hexarg.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 | e7502631a0f9 |
children |
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/* * Many commands take hex arguments. This module contains the parse_hexarg() * function, which is a wrapper around strtoul that performs some additional * checks. */ #include <sys/types.h> #include <ctype.h> #include <stdlib.h> parse_hexarg(arg, maxdigits, valp) char *arg; int maxdigits; u_long *valp; { char *cp = arg, *bp; int len; if (cp[0] == '0' && (cp[1] == 'x' || cp[1] == 'X')) cp += 2; for (bp = cp; *cp; cp++) if (!isxdigit(*cp)) return(-1); len = cp - bp; if (len < 1 || len > maxdigits) return(-1); *valp = strtoul(arg, 0, 16); return(0); }