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 (before :, which is needed to avoid printing errors) 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. Now that we change the parsing mode between close_open_files() and conf(), we need to reset optind to 0, not to 1, whenever we call getopt_long() again in conf(), so that the internal initialisation of getopt_long() evaluating GNU extensions is re-triggered. 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(a)redhat.com> --- v2: Reset optind to 0 before any further call to getopt_long() in conf() conf.c | 6 +++--- util.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/conf.c b/conf.c index ed097bd..ba82696 100644 --- a/conf.c +++ b/conf.c @@ -1261,7 +1261,7 @@ void conf(struct ctx *c, int argc, char **argv) c->tcp.fwd_in.mode = c->tcp.fwd_out.mode = FWD_UNSET; c->udp.fwd_in.mode = c->udp.fwd_out.mode = FWD_UNSET; - optind = 1; + optind = 0; do { name = getopt_long(argc, argv, optstring, options, NULL); @@ -1648,7 +1648,7 @@ void conf(struct ctx *c, int argc, char **argv) * settings) */ udp_portmap_clear(); - optind = 1; + optind = 0; do { name = getopt_long(argc, argv, optstring, options, NULL); @@ -1720,7 +1720,7 @@ void conf(struct ctx *c, int argc, char **argv) nl_sock_init(c, true); /* ...and outbound port options now that namespaces are set up. */ - optind = 1; + optind = 0; do { name = getopt_long(argc, argv, optstring, options, NULL); 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; -- 2.43.0