evaluate: place byteorder conversion after numgen for IP address datatypes

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>

4 files changed, 73 insertions, 0 deletions

diff --git a/tests/py/ip/numgen.t b/tests/py/ip/numgen.t
index 29a6a105..2a881460 100644
--- a/tests/py/ip/numgen.t
+++ b/tests/py/ip/numgen.t
@@ -5,3 +5,5 @@ ct mark set numgen inc mod 2;ok
 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
diff --git a/tests/py/ip/numgen.t.json b/tests/py/ip/numgen.t.json
index 9902c2cf..6cf66041 100644
--- a/tests/py/ip/numgen.t.json
+++ b/tests/py/ip/numgen.t.json
@@ -97,3 +97,33 @@
     }
 ]
 
+# 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
+                }
+            }
+        }
+    }
+]
+
diff --git a/tests/py/ip/numgen.t.json.output b/tests/py/ip/numgen.t.json.output
index b54121ca..06ad1ecc 100644
--- a/tests/py/ip/numgen.t.json.output
+++ b/tests/py/ip/numgen.t.json.output
@@ -80,3 +80,33 @@
     }
 ]
 
+# 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
+                }
+            }
+        }
+    }
+]
+
diff --git a/tests/py/ip/numgen.t.payload b/tests/py/ip/numgen.t.payload
index 3349c68b..b4eadf85 100644
--- a/tests/py/ip/numgen.t.payload
+++ b/tests/py/ip/numgen.t.payload
@@ -27,3 +27,14 @@ ip test-ip4 pre
   [ 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 ]