Feed nft-generated ruleset to iptables-nft.
At this time, this will NOT pass. because dissector can handle
meta l4proto tcp ip saddr 1.2.3.4
but not
ip saddr 1.2.3.4 meta l4proto tcp
In the latter case, iptables-nft picks up the immediate value (6) as the ip
address, because the first one (1.2.3.4) gets moved as PAYLOAD_PREV due to
missing 'removal' of the CTX_PAYLOAD flag.
This is error prone, so lets rewrite the dissector to track each
register separately and auto-clear state on writes.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Phil Sutter <phil@nwl.cc>
--- /dev/null
+*filter
+:INPUT ACCEPT [0:0]
+:FORWARD ACCEPT [0:0]
+:OUTPUT ACCEPT [0:0]
+-A INPUT -s 1.2.3.4/32 -p tcp -m tcp --dport 23 -j ACCEPT
+-A INPUT -s 1.2.3.0/24 -d 0.0.0.0/32 -p udp -m udp --dport 67:69 -j DROP
+-A INPUT -s 1.0.0.0/8 -d 0.0.0.0/32 -p tcp -m tcp --sport 1024:65535 --dport 443 --tcp-flags SYN,ACK SYN -j ACCEPT
+-A INPUT -p tcp -m tcp --dport 443 ! --tcp-flags SYN NONE -m comment --comment "checks if SYN bit is set"
+-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m comment --comment "same as iptables --syn"
+-A INPUT -p tcp -m tcp --tcp-flags SYN SYN
+-A INPUT -p tcp -m tcp ! --tcp-flags SYN,ACK SYN,ACK
+-A INPUT -d 0.0.0.0/1 -m ttl --ttl-eq 1 -j DROP
+-A INPUT -d 0.0.0.0/2 -m ttl --ttl-gt 2 -j ACCEPT
+-A INPUT -d 0.0.0.0/3 -m ttl --ttl-lt 254 -j ACCEPT
+-A INPUT -d 0.0.0.0/4 -m ttl ! --ttl-eq 255 -j DROP
+-A INPUT -d 8.0.0.0/5 -p icmp -j ACCEPT
+-A INPUT -d 8.0.0.0/6 -p icmp -j ACCEPT
+-A INPUT -d 10.0.0.0/7 -p icmp -j ACCEPT
+-A INPUT -m pkttype --pkt-type broadcast -j ACCEPT
+-A INPUT -m pkttype ! --pkt-type unicast -j DROP
+-A INPUT -p tcp
+-A INPUT -d 0.0.0.0/1 -p udp
+-A FORWARD -m limit --limit 10/day
+-A FORWARD -p udp -m udp --dport 42
+-A FORWARD -i lo -o lo+ -j NFLOG --nflog-prefix "should use NFLOG" --nflog-group 1 --nflog-size 123 --nflog-threshold 42
+COMMIT
set -e
-nft -f - <<EOF
-table ip filter {
- chain FORWARD {
- type filter hook forward priority filter;
- limit rate 10/day counter
- udp dport 42 counter
- }
-}
-EOF
-
-EXPECT="*filter
-:INPUT ACCEPT [0:0]
-:FORWARD ACCEPT [0:0]
-:OUTPUT ACCEPT [0:0]
--A FORWARD -m limit --limit 10/day
--A FORWARD -p udp -m udp --dport 42
-COMMIT"
-
-diff -u -Z <(echo -e "$EXPECT") <($XT_MULTI iptables-save | grep -v '^#')
+unshare -n bash -c "nft -f $(dirname $0)/0010-nft-native.txt;
+ diff -u -Z $(dirname $0)/0010-iptables-nft-save.txt <($XT_MULTI iptables-save | grep -v '^#')"
--- /dev/null
+table ip filter {
+ chain INPUT {
+ type filter hook input priority filter; policy accept;
+
+ ip saddr 1.2.3.4 tcp dport 23 accept
+ ip saddr 1.2.3.0/24 ip daddr 0.0.0.0 udp dport 67-69 drop
+
+ ip saddr 1.0.0.0/8 ip daddr 0.0.0.0 tcp sport 1024-65535 tcp dport 443 tcp flags syn / syn,ack accept
+ tcp dport 443 tcp flags syn comment "checks if SYN bit is set"
+ tcp flags syn / syn,rst,ack,fin comment "same as iptables --syn"
+ tcp flags & syn == syn
+ tcp flags & (syn | ack) != (syn | ack )
+
+ ip daddr 0.0.0.0/1 ip ttl 1 drop
+ ip daddr 0.0.0.0/2 ip ttl > 2 accept
+ ip daddr 0.0.0.0/3 ip ttl < 254 accept
+ ip daddr 0.0.0.0/4 ip ttl != 255 drop
+
+ ip daddr 8.0.0.0/5 icmp type 1 accept
+ ip daddr 8.0.0.0/6 icmp type 2 icmp code port-unreachable accept
+ ip daddr 10.0.0.0/7 icmp type echo-request accept
+
+ meta pkttype broadcast accept
+ meta pkttype != host drop
+
+ ip saddr 0.0.0.0/0 ip protocol tcp
+ ip daddr 0.0.0.0/1 ip protocol udp
+ }
+
+ chain FORWARD {
+ type filter hook forward priority filter;
+ limit rate 10/day counter
+ udp dport 42 counter
+
+ # FIXME: can't dissect plain syslog
+ # meta iif "lo" log prefix "just doing a log" level alert flags tcp sequence,options
+
+ # iif, not iifname, and wildcard
+ meta iif "lo" oifname "lo*" log group 1 prefix "should use NFLOG" queue-threshold 42 snaplen 123
+ }
+}