payload: explicit network ctx assignment for icmp/icmp6 in special families

In the inet, bridge and netdev families, we can add rules like these:

% nft add rule inet t c ip protocol icmp icmp type echo-request
% nft add rule inet t c ip6 nexthdr icmpv6 icmpv6 type echo-request

However, when we print the ruleset:

% nft list ruleset
table inet t {
	chain c {
		icmpv6 type echo-request
		icmp type echo-request
	}
}

These rules we obtain can't be added again:

% nft add rule inet t c icmp type echo-request
<cmdline>:1:19-27: Error: conflicting protocols specified: inet-service vs. icmp
add rule inet t c icmp type echo-request
                  ^^^^^^^^^

% nft add rule inet t c icmpv6 type echo-request
<cmdline>:1:19-29: Error: conflicting protocols specified: inet-service vs. icmpv6
add rule inet t c icmpv6 type echo-request
                  ^^^^^^^^^^^

Since I wouldn't expect an IP packet carrying ICMPv6, or IPv6 packet
carrying ICMP, if the link layer is inet, the network layer protocol context
can be safely update to 'ip' or 'ip6'.

Moreover, nft currently generates a 'meta nfproto ipvX' depedency when
using icmp or icmp6 in the inet family, and similar in netdev and bridge
families.

While at it, a bit of code factorization is introduced.

Fixes: https://bugzilla.netfilter.org/show_bug.cgi?id=1073
Signed-off-by: Arturo Borrero Gonzalez <arturo@debian.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

0 files changed, 0 insertions, 0 deletions