src: integrate stateful expressions into sets and maps

The following example shows how to populate a set from the packet path
using the destination IP address, for each entry there is a counter. The
entry expires after the 1 hour timeout if no packets matching this entry
are seen.

 table ip x {
        set xyz {
                type ipv4_addr
                size 65535
                flags dynamic,timeout
                timeout 1h
        }

        chain y {
                type filter hook output priority filter; policy accept;
                update @xyz { ip daddr counter } counter
        }
 }

Similar example, that creates a mapping better IP address and mark,
where the mark is assigned using an incremental sequence generator from
0 to 1 inclusive.

 table ip x {
        map xyz {
                type ipv4_addr : mark
                size 65535
                flags dynamic,timeout
                timeout 1h
        }

        chain y {
                type filter hook input priority filter; policy accept;
                update @xyz { ip saddr counter : numgen inc mod 2 }
        }
 }

Supported stateful statements are: limit, quota, counter and connlimit.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/statement.h b/include/statement.h
index 6c583a91..48ba6673 100644
--- a/include/statement.h
+++ b/include/statement.h
@@ -184,6 +184,7 @@ uint32_t fwd_stmt_type(const char *type);
 struct set_stmt {
 	struct expr		*set;
 	struct expr		*key;
+	struct stmt		*stmt;
 	enum nft_dynset_ops	op;
 };
 
@@ -195,6 +196,7 @@ struct map_stmt {
 	struct expr		*set;
 	struct expr		*key;
 	struct expr		*data;
+	struct stmt		*stmt;
 	enum nft_dynset_ops	op;
 };