[PATCH net] net: don't dump Tx and uninitialized NAPIs

[Jakub Kicinski <kuba@kernel.org>]

We use NAPI ID as the key for continuing dumps. We also depend
on the NAPIs being sorted by ID within the driver list. Tx NAPIs
(which don't have an ID assigned) break this expectation, it's
not currently possible to dump them reliably. Since Tx NAPIs
are relatively rare, and can't be used in doit (GET or SET)
hide them from the dump API as well.

Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: jdamato@fastly.com
CC: almasrymina@google.com
CC: sridhar.samudrala@intel.com
CC: amritha.nambiar@intel.com
---
 net/core/netdev-genl.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 2d3ae0cd3ad2..319521f37f72 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -176,8 +176,7 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 	if (!hdr)
 		return -EMSGSIZE;
 
-	if (napi->napi_id >= MIN_NAPI_ID &&
-	    nla_put_u32(rsp, NETDEV_A_NAPI_ID, napi->napi_id))
+	if (nla_put_u32(rsp, NETDEV_A_NAPI_ID, napi->napi_id))
 		goto nla_put_failure;
 
 	if (nla_put_u32(rsp, NETDEV_A_NAPI_IFINDEX, napi->dev->ifindex))
@@ -268,6 +267,8 @@ netdev_nl_napi_dump_one(struct net_device *netdev, struct sk_buff *rsp,
 		return err;
 
 	list_for_each_entry(napi, &netdev->napi_list, dev_list) {
+		if (napi->napi_id < MIN_NAPI_ID)
+			continue;
 		if (ctx->napi_id && napi->napi_id >= ctx->napi_id)
 			continue;
 
-- 
2.47.1