[PATCH net 12/12] net: shaper: reject QUEUE scope handle with missing id

[Jakub Kicinski]

net_shaper_parse_handle() does not enforce that the user provides
the handle ID. For NODE the ID defaults to UNSPEC for all other
cases it defaults to 0.

For NETDEV 0 is the only option. For QUEUE defaulting to 0 makes
less intuitive sense. Specifically because the behavior should
(IMHO) be the same for all cases where there may be more than
one ID (QUEUE and NODE).

We should either document this as intentional or reject.
I picked the latter with no strong conviction.

Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation")
Signed-off-by: Jakub Kicinski <k...@kernel.org>
---
 net/shaper/shaper.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c
index 2adf8b0e1105..daaefc02237b 100644
--- a/net/shaper/shaper.c
+++ b/net/shaper/shaper.c
@@ -491,10 +491,15 @@ static int net_shaper_parse_handle(const struct nlattr 
*attr,
         * shaper (any other value).
         */
        id_attr = tb[NET_SHAPER_A_HANDLE_ID];
-       if (id_attr)
+       if (id_attr) {
                id = nla_get_u32(id_attr);
-       else if (handle->scope == NET_SHAPER_SCOPE_NODE)
+       } else if (handle->scope == NET_SHAPER_SCOPE_NODE) {
                id = NET_SHAPER_ID_UNSPEC;
+       } else if (handle->scope == NET_SHAPER_SCOPE_QUEUE) {
+               NL_SET_ERR_ATTR_MISS(info->extack, attr,
+                                    NET_SHAPER_A_HANDLE_ID);
+               return -EINVAL;
+       }
 
        handle->id = id;
        return 0;
-- 
2.54.0