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| author | Jakub Kicinski <kuba@kernel.org> | 2022-08-24 17:18:30 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-08-29 12:47:15 +0100 |
| commit | 9c5d03d362519f36cd551aec596388f895c93d2d (patch) | |
| tree | 5669b75a062436435dc9d4354c668d0f61b7146c /include/net/genetlink.h | |
| parent | 53a406803ca5b0b1f91beffacad4321fae4fa2a7 (diff) | |
| download | lwn-9c5d03d362519f36cd551aec596388f895c93d2d.tar.gz lwn-9c5d03d362519f36cd551aec596388f895c93d2d.zip | |
genetlink: start to validate reserved header bytes
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.
One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.
To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/genetlink.h')
| -rw-r--r-- | include/net/genetlink.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h index 56a50e1c51b9..a4827b5e1e07 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -39,6 +39,8 @@ struct genl_info; * undo operations done by pre_doit, for example release locks * @mcgrps: multicast groups used by this family * @n_mcgrps: number of multicast groups + * @resv_start_op: first operation for which reserved fields of the header + * can be validated, new families should leave this field at zero * @mcgrp_offset: starting number of multicast group IDs in this family * (private) * @ops: the operations supported by this family @@ -58,6 +60,7 @@ struct genl_family { u8 n_ops; u8 n_small_ops; u8 n_mcgrps; + u8 resv_start_op; const struct nla_policy *policy; int (*pre_doit)(const struct genl_ops *ops, struct sk_buff *skb, |