Re: How to use concatenation ipv4_addr . inet_proto . inet_service

[Florian Westphal]

Vladimir Khailenko <vkhaile...@funio.com> wrote:

[ CC netfilter-devel ]

> We can create a set with "ipv4_addr . inet_proto . inet_service":
> set allow_dns_ntp {
>   type ipv4_addr . inet_proto . inet_service
>   elements = { 1.2.3.4 . tcp . domain,
>                1.2.3.4 . udp . domain,
>                5.6.7.8 . udp . ntp }
> }
> 
> But how the we can use them?
> "iifname $nic_wan ip daddr . protocol . dport @allow_dns_ntp ct state new 
> counter accept" - Does not work
> "iifname $nic_wan ip daddr . ip protocol . tcp dport @allow_dns_ntp ct state 
> new counter accept" - this works, but does not have any sense…

Yes, that doesn't work.  This could work, with a small patch:

add rule inet filter input iifname lo  ip daddr . ip protocol . @th,16,16 
@allow_dns_ntp ct state new counter accept

diff --git a/src/payload.c b/src/payload.c
--- a/src/payload.c
+++ b/src/payload.c
@@ -175,6 +175,11 @@ void payload_init_raw(struct expr *expr, enum proto_bases 
base,
        expr->payload.offset    = offset;
        expr->len               = len;
        expr->dtype             = &integer_type;
+
+       if (len == 16 && base == PROTO_BASE_TRANSPORT_HDR) {
+               if (offset == 0 || offset == 16)
+                       expr->dtype = &inet_service_type;
+       }
 }