From a9977eca9145b9f061ceb1d1604f59efba1b2949 Mon Sep 17 00:00:00 2001 From: Jo-Philipp Wich Date: Tue, 12 Apr 2011 20:03:59 +0000 Subject: [PATCH] firewall: allow local redirection of ports Allow a redirect like: config redirect option src 'wan' option dest 'lan' option src_dport '22001' option dest_port '22' option proto 'tcp' note the absence of the "dest_ip" field, meaning to terminate the connection on the firewall itself. This patch makes three changes: (1) moves the conntrack module into the conntrack package (but not any of the conntrack_* helpers). (2) fixes a bug where the wrong table is used when the "dest_ip" field is absent. (3) accepts incoming connections on the destination port on the input_ZONE table, but only for DNATted connections. In the above example, ssh -p 22 root@myrouter would fail from the outside, but: ssh -p 22001 root@myrouter would succeed. This is handy if: (1) you want to avoid ssh probes on your router, or (2) you want to redirect incoming connections on port 22 to some machine inside your firewall, but still want to allow firewall access from outside. Signed-off-by: Philip Prindeville SVN-Revision: 26617 --- include/netfilter.mk | 4 ++-- package/firewall/files/lib/core_redirect.sh | 5 ++--- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/include/netfilter.mk b/include/netfilter.mk index fe468fca31..9da455a07a 100644 --- a/include/netfilter.mk +++ b/include/netfilter.mk @@ -60,6 +60,8 @@ $(eval $(call nf_add,IPT_CONNTRACK,CONFIG_NETFILTER_XT_MATCH_STATE, $(P_XT)xt_st $(eval $(call nf_add,IPT_CONNTRACK,CONFIG_IP_NF_RAW, $(P_V4)iptable_raw)) $(eval $(call nf_add,IPT_CONNTRACK,CONFIG_IP_NF_TARGET_NOTRACK, $(P_V4)ipt_NOTRACK)) $(eval $(call nf_add,IPT_CONNTRACK,CONFIG_NETFILTER_XT_TARGET_NOTRACK, $(P_XT)xt_NOTRACK)) +$(eval $(call nf_add,IPT_CONNTRACK,CONFIG_IP_NF_MATCH_CONNTRACK, $(P_V4)ipt_conntrack)) +$(eval $(call nf_add,IPT_CONNTRACK,CONFIG_NETFILTER_XT_MATCH_CONNTRACK, $(P_XT)xt_conntrack)) # conntrack-extra @@ -68,8 +70,6 @@ $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_IP_NF_MATCH_CONNBYTES, $(P_V4)ip $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_NETFILTER_XT_MATCH_CONNBYTES, $(P_XT)xt_connbytes)) $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_IP_NF_MATCH_CONNMARK, $(P_V4)ipt_connmark)) $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_NETFILTER_XT_MATCH_CONNMARK, $(P_XT)xt_connmark)) -$(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_IP_NF_MATCH_CONNTRACK, $(P_V4)ipt_conntrack)) -$(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_NETFILTER_XT_MATCH_CONNTRACK, $(P_XT)xt_conntrack)) $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_IP_NF_MATCH_HELPER, $(P_V4)ipt_helper)) $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_NETFILTER_XT_MATCH_HELPER, $(P_XT)xt_helper)) $(eval $(call nf_add,IPT_CONNTRACK_EXTRA,CONFIG_IP_NF_MATCH_RECENT, $(P_V4)ipt_recent)) diff --git a/package/firewall/files/lib/core_redirect.sh b/package/firewall/files/lib/core_redirect.sh index 87941a2a17..64c619e434 100644 --- a/package/firewall/files/lib/core_redirect.sh +++ b/package/firewall/files/lib/core_redirect.sh @@ -34,7 +34,7 @@ fw_load_redirect() { return 0 } - fwdchain="zone_${redirect_src}_forward" + fwdchain="zone_${redirect_src}${redirect_dest_ip:+_forward}" natopt="--to-destination" natchain="zone_${redirect_src}_prerouting" @@ -100,9 +100,8 @@ fw_load_redirect() { $natopt $nataddr${natports:+:$natports} \ } - [ -n "$destaddr" ] && \ fw add $mode f ${fwdchain:-forward} ACCEPT ^ { $redirect_src_ip $redirect_dest_ip } { \ - $srcaddr $destaddr \ + $srcaddr ${destaddr:--m conntrack --ctstate DNAT} \ ${redirect_proto:+-p $redirect_proto} \ ${srcports:+--sport $srcports} \ ${destports:+--dport $destports} \ -- 2.30.2