src: add offset attribute for hash expression

Add support to add an offset to the hash generator, eg.

 ct mark set hash ip saddr mod 10 offset 100

This will generate marks with series between 100-109.

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 16 insertions, 0 deletions

diff --git a/tests/py/ip/hash.t b/tests/py/ip/hash.t
index 306ebfd0..0d01a11d 100644
--- a/tests/py/ip/hash.t
+++ b/tests/py/ip/hash.t
@@ -3,4 +3,6 @@
 
 ct mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef;ok
 ct mark set jhash ip saddr . ip daddr mod 2;ok
+ct mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef offset 100;ok
+ct mark set jhash ip saddr . ip daddr mod 2 offset 100;ok
 dnat to jhash ip saddr mod 2 seed 0xdeadbeef map { 0 : 192.168.20.100, 1 : 192.168.30.100 };ok
diff --git a/tests/py/ip/hash.t.payload b/tests/py/ip/hash.t.payload
index 1188a1b1..c410a8c6 100644
--- a/tests/py/ip/hash.t.payload
+++ b/tests/py/ip/hash.t.payload
@@ -12,6 +12,20 @@ ip test-ip4 pre
   [ hash reg 1 = jhash(reg 2, 8, 0x0) % mod 2 ]
   [ ct set mark with reg 1 ]
 
+# ct mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef offset 100
+ip test-ip4 pre
+  [ payload load 4b @ network header + 12 => reg 2 ]
+  [ payload load 4b @ network header + 16 => reg 13 ]
+  [ hash reg 1 = jhash(reg 2, 8, 0xdeadbeef) % mod 2 offset 100 ]
+  [ ct set mark with reg 1 ]
+
+# ct mark set jhash ip saddr . ip daddr mod 2 offset 100
+ip test-ip4 pre
+  [ payload load 4b @ network header + 12 => reg 2 ]
+  [ payload load 4b @ network header + 16 => reg 13 ]
+  [ hash reg 1 = jhash(reg 2, 8, 0x0) % mod 2 offset 100 ]
+  [ ct set mark with reg 1 ]
+
 # dnat to jhash ip saddr mod 2 seed 0xdeadbeef map { 0 : 192.168.20.100, 1 : 192.168.30.100 }
 __map%d test-ip4 b
 __map%d test-ip4 0