On Sun, Mar 15, 2020 at 12:21:02PM +0200, 0xef967...@gmail.com wrote:
> On Sun, Mar 15, 2020 at 09:30:22AM +0100, Martijn van Duren wrote:
> > > --- lib/libc/stdlib/getopt_long.c~
> > > +++ lib/libc/stdlib/getopt_long.c
> > > @@ -418,15 +418,8 @@
> > > }
> > >
> > > if ((optchar = (int)*place++) == (int)':' ||
> > > - (optchar == (int)'-' && *place != '\0') ||
> > > - (oli = strchr(options, optchar)) == NULL) {
> > > - /*
> > > - * If the user specified "-" and '-' isn't listed in
> > > - * options, return -1 (non-option) as per POSIX.
> > > - * Otherwise, it is an unknown option character (or ':').
> > > - */
> > > - if (optchar == (int)'-' && *place == '\0')
> > > - return (-1);
> > > + ((oli = strchr(options, optchar)) == NULL ||
> > > + (optchar == (int)'-' && oli == options))) {
> > > if (!*place)
> > > ++optind;
> > > if (PRINT_ERROR)
A "side-effect" of my patch is that it prevents the only case where
OpenBSD's getopt(3) was clinging to the stale state after having
finished parsing the arguments and returned -1.
The patch restore the older behaviour where you could just set
"optind = 1" in order to parse another list of arguments (instead of
the unportable "optreset = 1" or "optind = 0"), without exposing you
to crashes and possible exploits.
That used to work in the old getopt(3) from *BSD, and in the (original?)
SysV version, but was broken in the glibc version of getopt(3) and,
in a corner case, in the getopt_long implementation from OpenBSD.
You could test it with the getopt-test-relocate.c program at the end
of this message.
More info at https://stackoverflow.com/questions/60483737, and a glibc
patch at https://sourceware.org/bugzilla/show_bug.cgi?id=25658
OPTS=q ./getopt-test-relocate-unpatched -q-
{./getopt-test-relocate-unpatched} <q> | {-q-}
getopt-test-relocate-unpatched: unknown option -- :
getopt-test-relocate-unpatched: unknown option -- O
getopt-test-relocate-unpatched: unknown option -- P
getopt-test-relocate-unpatched: unknown option -- T
getopt-test-relocate-unpatched: unknown option -- S
getopt-test-relocate-unpatched: unknown option -- =
{./getopt-test-relocate-unpatched} #U: #UO #UP #UT #US #U= <q> |
=====================================================================
getopt-test-relocate.c
=====================================================================
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
static int showargs(int ac, char **av, char *os){
char *s; int c, i;
if(ac < 1) return 1;
printf("{%s}", av[0]);
while((c = getopt(ac, av, os)) != -1)
switch(c){
case '?':
printf(" #U%c", optopt); break;
case ':':
printf(" #A%c", optopt); break;
case '\1':
printf(" <\\1>={%s}", optarg); break;
default:
if((s = strrchr(os, c)) && s[1] == ':')
printf(" <%c>={%s}", c, optarg);
else
printf(" <%c>", c);
}
printf(" |");
for(i = optind; i < ac; i++) printf(" {%s}", av[i]);
printf("\n");
return 0;
}
static void relocate_args(int ac, char **av){
int i;
for(i = 1; i < ac; i++){
char *o = av[i]; size_t l = strlen(o);
if(!(av[i] = strdup(o))) abort();
memset(o, ':', l + 1);
}
}
int main(int ac, char **av){
char *os;
if(!(os = getenv("OPTS"))) os = "";
showargs(ac, av, os);
relocate_args(ac, av);
optind = 1;
return showargs(ac, av, os);
}
