src: Add command "replace" for rules

Modify the parser and add necessary functions to provide the command "nft
replace rule <ruleid_spec> <new_rule>"

Example of use:

	# nft list ruleset -a
	table ip filter {
		chain output {
			ip daddr 8.8.8.7 counter packets 0 bytes 0 # handle 3
		}
	}
	# nft replace rule filter output handle 3 ip daddr 8.8.8.8 counter
	# nft list ruleset -a
	table ip filter {
		chain output {
			ip daddr 8.8.8.8 counter packets 0 bytes 0 # handle 3
		}
	}

Signed-off-by: Carlos Falgueras García <carlosfg@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/mnl.c b/src/mnl.c
index e4253e53..52875f4a 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -301,6 +301,22 @@ int mnl_nft_rule_batch_add(struct nftnl_rule *nlr, unsigned int flags,
 	return 0;
 }
 
+int mnl_nft_rule_batch_replace(struct nftnl_rule *nlr, unsigned int flags,
+			       uint32_t seqnum)
+{
+	struct nlmsghdr *nlh;
+
+	nlh = nftnl_rule_nlmsg_build_hdr(nftnl_batch_buffer(batch),
+			NFT_MSG_NEWRULE,
+			nftnl_rule_get_u32(nlr, NFTNL_RULE_FAMILY),
+			NLM_F_REPLACE | flags, seqnum);
+
+	nftnl_rule_nlmsg_build_payload(nlh, nlr);
+	mnl_nft_batch_continue();
+
+	return 0;
+}
+
 int mnl_nft_rule_batch_del(struct nftnl_rule *nlr, unsigned int flags,
 			   uint32_t seqnum)
 {