From 6009904eb4dfe91e3d0b5cb96c4095232a303835 Mon Sep 17 00:00:00 2001 From: Jo-Philipp Wich Date: Mon, 8 Aug 2016 15:52:28 +0200 Subject: [PATCH] zones: restrict default ACCEPT rules to NEW ctstate Restrict the per-zone default accept rules to only accept streams with conntrack state NEW when drop_invalid is disabled. This commit hardens the firewall in order to allow disabling drop_invalid by default since ctstate INVALID also matches desired traffic like IPv6 neighbour discovery messages. Signed-off-by: Jo-Philipp Wich --- zones.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/zones.c b/zones.c index 66c70a5..3682435 100644 --- a/zones.c +++ b/zones.c @@ -348,6 +348,10 @@ print_interface_rule(struct fw3_ipt_handle *handle, struct fw3_state *state, r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL); fw3_ipt_rule_target(r, jump_target(t)); fw3_ipt_rule_extra(r, zone->extra_src); + + if (t == FW3_FLAG_ACCEPT && !state->defaults.drop_invalid) + fw3_ipt_rule_extra(r, "-m conntrack --ctstate NEW"); + fw3_ipt_rule_replace(r, "zone_%s_src_%s", zone->name, fw3_flag_names[t]); } @@ -357,6 +361,10 @@ print_interface_rule(struct fw3_ipt_handle *handle, struct fw3_state *state, r = fw3_ipt_rule_create(handle, NULL, NULL, dev, NULL, sub); fw3_ipt_rule_target(r, jump_target(t)); fw3_ipt_rule_extra(r, zone->extra_dest); + + if (t == FW3_FLAG_ACCEPT && !state->defaults.drop_invalid) + fw3_ipt_rule_extra(r, "-m conntrack --ctstate NEW"); + fw3_ipt_rule_replace(r, "zone_%s_dest_%s", zone->name, fw3_flag_names[t]); } -- 2.11.0