expr: counter: Do not print unset values in json

It changes the parse and the snprint functions to omit unset values.

Signed-off-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/expr/counter.c b/src/expr/counter.c
index 6f6a7ee9d16f224b79cf949b957332d07a5fd018..5ab9a5a04fe4be9c0afce8235583cc991e3b2da4 100644 (file)
--- a/src/expr/counter.c
+++ b/src/expr/counter.c
@@ -125,15 +125,13 @@ nft_rule_expr_counter_json_parse(struct nft_rule_expr *e, json_t *root,
 #ifdef JSON_PARSING
        uint64_t uval64;
 
-       if (nft_jansson_parse_val(root, "pkts", NFT_TYPE_U64, &uval64, err) < 0)
-               return -1;
-
-       nft_rule_expr_set_u64(e, NFT_EXPR_CTR_PACKETS, uval64);
-
-       if (nft_jansson_parse_val(root, "bytes", NFT_TYPE_U64, &uval64, err) < 0)
-               return -1;
+       if (nft_jansson_parse_val(root, "pkts", NFT_TYPE_U64, &uval64,
+                                 err) == 0)
+               nft_rule_expr_set_u64(e, NFT_EXPR_CTR_PACKETS, uval64);
 
-       nft_rule_expr_set_u64(e, NFT_EXPR_CTR_BYTES, uval64);
+       if (nft_jansson_parse_val(root, "bytes", NFT_TYPE_U64, &uval64,
+                                 err) == 0)
+               nft_rule_expr_set_u64(e, NFT_EXPR_CTR_BYTES, uval64);
 
        return 0;
 #else
@@ -166,10 +164,23 @@ nft_rule_expr_counter_xml_parse(struct nft_rule_expr *e, mxml_node_t *tree,
 static int nft_rule_expr_counter_snprintf_json(char *buf, size_t len,
                                               struct nft_rule_expr *e)
 {
+       int ret, size = len, offset = 0;
        struct nft_expr_counter *ctr = nft_expr_data(e);
 
-       return snprintf(buf, len, "\"pkts\":%"PRIu64",\"bytes\":%"PRIu64"",
-                       ctr->pkts, ctr->bytes);
+       if (e->flags & (1 << NFT_EXPR_CTR_PACKETS)) {
+               ret = snprintf(buf, len,"\"pkts\":%"PRIu64",", ctr->pkts);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+       if (e->flags & (1 << NFT_EXPR_CTR_BYTES)) {
+               ret = snprintf(buf + offset, len, "\"bytes\":%"PRIu64",", ctr->bytes);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       /* Remove the last comma characther */
+       if (offset > 0)
+               offset--;
+
+       return offset;
 }
 
 static int nft_rule_expr_counter_snprintf_xml(char *buf, size_t len,