| Message ID | 20201006181555.103140-1-johannes@sipsolutions.net |
|---|---|
| Headers | show |
| Series | netlink: export policy on validation failures | expand |
On Tue, 6 Oct 2020 20:15:53 +0200 Johannes Berg wrote: > Export the policy used for attribute validation when it fails, > so e.g. for an out-of-range attribute userspace immediately gets > the valid ranges back. > > v2 incorporates the suggestion from Jakub to have a function to > estimate the size (netlink_policy_dump_attr_size_estimate()) and > check that it does the right thing on the *normal* policy dumps, > not (just) when calling it from the error scenario. > > > Tested using nl80211/iw in a few scenarios, seems to work fine > and return the policy back, e.g. > > kernel reports: integer out of range > policy: 04 00 0b 00 0c 00 04 00 01 00 00 00 00 00 00 00 > ^ padding > ^ minimum allowed value > policy: 04 00 0b 00 0c 00 05 00 ff ff ff ff 00 00 00 00 > ^ padding > ^ maximum allowed value > policy: 08 00 01 00 04 00 00 00 > ^ type 4 == U32 > > for an out-of-range case. Too minor nits, with those addressed: Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Export the policy used for attribute validation when it fails, so e.g. for an out-of-range attribute userspace immediately gets the valid ranges back. v2 incorporates the suggestion from Jakub to have a function to estimate the size (netlink_policy_dump_attr_size_estimate()) and check that it does the right thing on the *normal* policy dumps, not (just) when calling it from the error scenario. Tested using nl80211/iw in a few scenarios, seems to work fine and return the policy back, e.g. kernel reports: integer out of range policy: 04 00 0b 00 0c 00 04 00 01 00 00 00 00 00 00 00 ^ padding ^ minimum allowed value policy: 04 00 0b 00 0c 00 05 00 ff ff ff ff 00 00 00 00 ^ padding ^ maximum allowed value policy: 08 00 01 00 04 00 00 00 ^ type 4 == U32 for an out-of-range case. johannes