[PATCH] util: Don't stop on unrelated values when looking for --fd in close_open_files()

[Stefano Brivio <sbrivio@redhat.com>]

Seen with krun: we get a file descriptor via --fd, but we close it and
happily use the same number for TCP files.

The issue is that if we also get other options before --fd, with
arguments, getopt_long() stops parsing them because it sees them as
non-option values.

Use the - modifier at the beginning of optstring, instead of +, which
means we'll continue parsing after finding unrelated option values,
but getopt_long() won't reorder them anyway: they'll be passed with
option value '1', which we can ignore.

By the way, we also need to add : after F in the optstring, so that
we're able to parse the option when given as short name as well.

Link: https://github.com/slp/krun/issues/17#issuecomment-2294943828
Fixes: baccfb95ce0e ("conf: Stop parsing options at first non-option argument")
Fixes: 09603cab28f9 ("passt, util: Close any open file that the parent might have leaked")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/util.c b/util.c
index 0b41404..3fce3c2 100644
--- a/util.c
+++ b/util.c
@@ -710,7 +710,7 @@ void close_open_files(int argc, char **argv)
 	int name, rc;
 
 	do {
-		name = getopt_long(argc, argv, "+:F", optfd, NULL);
+		name = getopt_long(argc, argv, "-:F:", optfd, NULL);
 
 		if (name == 'F') {
 			errno = 0;
-- 
@@ -710,7 +710,7 @@ void close_open_files(int argc, char **argv)
 	int name, rc;
 
 	do {
-		name = getopt_long(argc, argv, "+:F", optfd, NULL);
+		name = getopt_long(argc, argv, "-:F:", optfd, NULL);
 
 		if (name == 'F') {
 			errno = 0;
-- 
2.43.0