src: make hash seed attribute optional

The hash expression requires a seed attribute to call the jhash
operation, eg.

 # nft add rule x y meta mark set jhash ip saddr . ip daddr mod 2 \
	seed 0xdeadbeef

With this patch the seed attribute is optional and it's generated by a
random function from userspace, eg.

 # nft add rule x y meta mark set jhash ip saddr . ip daddr mod 2

The kernel will take care of generate a random seed.

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

diff --git a/src/parser_bison.y b/src/parser_bison.y
index 17f23c5bf6b57b2216d9409d211f166739a7d2d6..82fec99c92404f165be41b48da21757ace258b91 100644 (file)
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -2585,6 +2585,11 @@ hash_expr                :       JHASH   expr    MOD     NUM     SEED    NUM
                                $$ = hash_expr_alloc(&@$, $4, $6);
                                $$->hash.expr = $2;
                        }
+                       |       JHASH   expr    MOD     NUM
+                       {
+                               $$ = hash_expr_alloc(&@$, $4, 0);
+                               $$->hash.expr = $2;
+                       }
                        ;
 
 rt_expr                        :       RT      rt_key

diff --git a/tests/py/ip/hash.t b/tests/py/ip/hash.t
index 6dfa965b59153ff880e9d94d790a08469fff3744..306ebfd084999f43d5b05529f15d706d805be875 100644 (file)
--- a/tests/py/ip/hash.t
+++ b/tests/py/ip/hash.t
@@ -2,4 +2,5 @@
 *ip;test-ip4;pre
 
 ct mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef;ok
+ct mark set jhash ip saddr . ip daddr mod 2;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 d9a22eba501cb488c903f4e19e3fb77a5216ae62..1188a1b1d1aa7ea0ad3cbc5d7d0dd0a9a2d8b637 100644 (file)
--- a/tests/py/ip/hash.t.payload
+++ b/tests/py/ip/hash.t.payload
@@ -5,6 +5,13 @@ ip test-ip4 pre
   [ hash reg 1 = jhash(reg 2, 8, 0xdeadbeef) % mod 2 ]
   [ ct set mark with reg 1 ]
 
+# ct mark set jhash ip saddr . ip daddr mod 2
+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 ]
+  [ 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