[nft PATCH 2/2] cache: Fix for doubled output after reset command

[Phil Sutter <phil@nwl.cc>]

Reset command causes a dump of the objects to reset and adds those to
cache. Yet it ignored if the object in question was already there and up
to now CMD_RESET was flagged as NFT_CACHE_FULL.

Tackle this from two angles: First, reduce cache requirements of reset
command to the necessary bits which is table cache. This alone would
suffice if there wasn't interactive mode (and other libnftables users):
A cache containing the objects to reset might be in place already, so
add dumped objects to cache only if they don't exist already.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 src/cache.c                                    |  4 +++-
 src/rule.c                                     |  3 ++-
 tests/shell/testcases/sets/0024named_objects_0 | 12 +++++++++++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/cache.c b/src/cache.c
index 0c28a28d3b554..05f0d68edf03a 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -138,8 +138,10 @@ unsigned int cache_evaluate(struct nft_ctx *nft, struct list_head *cmds)
 		case CMD_GET:
 			flags = evaluate_cache_get(cmd, flags);
 			break;
-		case CMD_LIST:
 		case CMD_RESET:
+			flags |= NFT_CACHE_TABLE;
+			break;
+		case CMD_LIST:
 		case CMD_EXPORT:
 		case CMD_MONITOR:
 			flags |= NFT_CACHE_FULL;
diff --git a/src/rule.c b/src/rule.c
index 57f1fc838399d..883b070720259 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -2582,7 +2582,8 @@ static int do_command_reset(struct netlink_ctx *ctx, struct cmd *cmd)
 	ret = netlink_reset_objs(ctx, cmd, type, dump);
 	list_for_each_entry_safe(obj, next, &ctx->list, list) {
 		table = table_lookup(&obj->handle, &ctx->nft->cache);
-		list_move(&obj->list, &table->objs);
+		if (!obj_lookup(table, obj->handle.obj.name, obj->type))
+			list_move(&obj->list, &table->objs);
 	}
 	if (ret < 0)
 		return ret;
diff --git a/tests/shell/testcases/sets/0024named_objects_0 b/tests/shell/testcases/sets/0024named_objects_0
index 3bd16f2fd028b..21200c3cca3cd 100755
--- a/tests/shell/testcases/sets/0024named_objects_0
+++ b/tests/shell/testcases/sets/0024named_objects_0
@@ -35,4 +35,14 @@ table inet x {
 set -e
 $NFT -f - <<< "$RULESET"
 
-$NFT reset counter inet x user321
+EXPECTED="table inet x {
+	counter user321 {
+		packets 12 bytes 1433
+	}
+}"
+
+GET="$($NFT reset counter inet x user321)"
+if [ "$EXPECTED" != "$GET" ] ; then
+	$DIFF -u <(echo "$EXPECTED") <(echo "$GET")
+	exit 1
+fi
-- 
2.24.1