src: add comment support for set declarations

Allow users to add a comment when declaring a named set.

Adds set output handling the comment in both nftables and json
format.

$ nft add table ip x
$ nft add set ip x s {type ipv4_addr\; comment "some_addrs"\; elements = {1.1.1.1, 1.2.3.4}}

$ nft list ruleset
table ip x {
	set s {
		type ipv4_addr;
		comment "some_addrs"
		elements = { 1.1.1.1, 1.2.3.4 }
	}
}

$ nft --json list ruleset
{
    "nftables": [
        {
            "metainfo": {
                "json_schema_version": 1,
                "release_name": "Capital Idea #2",
                "version": "0.9.6"
            }
        },
        {
            "table": {
                "family": "ip",
                "handle": 4857,
                "name": "x"
            }
        },
        {
            "set": {
                "comment": "some_addrs",
                "elem": [
                    "1.1.1.1",
                    "1.2.3.4"
                ],
                "family": "ip",
                "handle": 1,
                "name": "s",
                "table": "x",
                "type": "ipv4_addr"
            }
        }
    ]
}

Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/rule.h b/include/rule.h
index 60eadfa3..caca63d0 100644
--- a/include/rule.h
+++ b/include/rule.h
@@ -309,6 +309,7 @@ void rule_stmt_insert_at(struct rule *rule, struct stmt *nstmt,
  * @rg_cache:	cached range element (left)
  * @policy:	set mechanism policy
  * @automerge:	merge adjacents and overlapping elements, if possible
+ * @comment:	comment
  * @desc.size:		count of set elements
  * @desc.field_len:	length of single concatenated fields, bytes
  * @desc.field_count:	count of concatenated fields
@@ -331,6 +332,7 @@ struct set {
 	bool			root;
 	bool			automerge;
 	bool			key_typeof_valid;
+	const char		*comment;
 	struct {
 		uint32_t	size;
 		uint8_t		field_len[NFT_REG32_COUNT];