The numgen extension generates numbers in little-endian.
This can be very tricky when trying to combine it with IP addresses, which use big endian.
This change adds a new byteorder operation to convert data type endianness.
Before this patch:
$ sudo nft -d netlink add rule nat snat_chain snat to numgen inc mod 7 offset 0x0a000001
ip nat snat_chain
[ numgen reg 1 = inc mod 7 offset
167772161 ]
[ nat snat ip addr_min reg 1 ]
After this patch:
$ sudo nft -d netlink add rule nat snat_chain snat to numgen inc mod 7 offset 0x0a000001
ip nat snat_chain
[ numgen reg 1 = inc mod 7 offset
167772161 ]
[ byteorder reg 1 = hton(reg 1, 4, 4) ]
[ nat snat ip addr_min reg 1 ]
Regression tests have been modified to include these new cases.
Signed-off-by: Jorge Ortiz Escribano <jorge.ortiz.escribano@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
return byteorder_conversion(ctx, expr, byteorder);
case EXPR_PREFIX:
return stmt_prefix_conversion(ctx, expr, byteorder);
+ case EXPR_NUMGEN:
+ if (dtype->type == TYPE_IPADDR)
+ return byteorder_conversion(ctx, expr, byteorder);
+ break;
default:
break;
}
ct mark set numgen inc mod 2 offset 100;ok
dnat to numgen inc mod 2 map { 0 : 192.168.10.100, 1 : 192.168.20.200 };ok
dnat to numgen inc mod 10 map { 0-5 : 192.168.10.100, 6-9 : 192.168.20.200};ok
+dnat to numgen inc mod 7 offset 167772161;ok
+dnat to numgen inc mod 255 offset 167772161;ok
}
]
+# dnat to numgen inc mod 7 offset 167772161
+[
+ {
+ "dnat": {
+ "addr": {
+ "numgen": {
+ "mod": 7,
+ "mode": "inc",
+ "offset": 167772161
+ }
+ }
+ }
+ }
+]
+
+# dnat to numgen inc mod 255 offset 167772161
+[
+ {
+ "dnat": {
+ "addr": {
+ "numgen": {
+ "mod": 255,
+ "mode": "inc",
+ "offset": 167772161
+ }
+ }
+ }
+ }
+]
+
}
]
+# dnat to numgen inc mod 7 offset 167772161
+[
+ {
+ "dnat": {
+ "addr": {
+ "numgen": {
+ "mod": 7,
+ "mode": "inc",
+ "offset": 167772161
+ }
+ }
+ }
+ }
+]
+
+# dnat to numgen inc mod 255 offset 167772161
+[
+ {
+ "dnat": {
+ "addr": {
+ "numgen": {
+ "mod": 255,
+ "mode": "inc",
+ "offset": 167772161
+ }
+ }
+ }
+ }
+]
+
[ numgen reg 1 = inc mod 2 offset 100 ]
[ ct set mark with reg 1 ]
+# dnat to numgen inc mod 7 offset 167772161
+ip test-ip4 pre
+ [ numgen reg 1 = inc mod 7 offset 167772161 ]
+ [ byteorder reg 1 = hton(reg 1, 4, 4) ]
+ [ nat dnat ip addr_min reg 1 ]
+
+# dnat to numgen inc mod 255 offset 167772161
+ip test-ip4 pre
+ [ numgen reg 1 = inc mod 255 offset 167772161 ]
+ [ byteorder reg 1 = hton(reg 1, 4, 4) ]
+ [ nat dnat ip addr_min reg 1 ]