From 6e857353e3ce7231fc852c6187df0c6dd81767ba Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Sat, 1 Oct 2022 00:36:50 +0200 Subject: [PATCH] extensions: TCPOPTSTRIP: Do not print empty options No point in printing anything if none of the bits are set. Fixes: aef4c1e727563 ("libxt_TCPOPTSTRIP") Signed-off-by: Phil Sutter (cherry picked from commit dba32a76aacf84181a9bd3ba1e301e59ab49d370) --- extensions/libxt_TCPOPTSTRIP.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/extensions/libxt_TCPOPTSTRIP.c b/extensions/libxt_TCPOPTSTRIP.c index 6ea3489224602..ff873f98b3aaa 100644 --- a/extensions/libxt_TCPOPTSTRIP.c +++ b/extensions/libxt_TCPOPTSTRIP.c @@ -142,6 +142,13 @@ tcpoptstrip_print_list(const struct xt_tcpoptstrip_target_info *info, } } +static bool tcpoptstrip_empty(const struct xt_tcpoptstrip_target_info *info) +{ + static const struct xt_tcpoptstrip_target_info empty = {}; + + return memcmp(info, &empty, sizeof(empty)) == 0; +} + static void tcpoptstrip_tg_print(const void *ip, const struct xt_entry_target *target, int numeric) @@ -149,6 +156,9 @@ tcpoptstrip_tg_print(const void *ip, const struct xt_entry_target *target, const struct xt_tcpoptstrip_target_info *info = (const void *)target->data; + if (tcpoptstrip_empty(info)) + return; + printf(" TCPOPTSTRIP options "); tcpoptstrip_print_list(info, numeric); } @@ -159,6 +169,9 @@ tcpoptstrip_tg_save(const void *ip, const struct xt_entry_target *target) const struct xt_tcpoptstrip_target_info *info = (const void *)target->data; + if (tcpoptstrip_empty(info)) + return; + printf(" --strip-options "); tcpoptstrip_print_list(info, true); } -- 2.40.0