netlink: clarify attribute length check documentation

The documentation for how the length of attributes
is checked is wrong ("Exact length" isn't true, the
policy checks are for "minimum length") and a bit
misleading. Make it more complete and explain what
really happens.

Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Johannes Berg 2011-11-03 00:10:05 +00:00 committed by David S. Miller
parent c30bc94758
commit 4b6cc7284d
1 changed files with 9 additions and 2 deletions

View File

@ -192,8 +192,15 @@ enum {
* NLA_NUL_STRING Maximum length of string (excluding NUL)
* NLA_FLAG Unused
* NLA_BINARY Maximum length of attribute payload
* NLA_NESTED_COMPAT Exact length of structure payload
* All other Exact length of attribute payload
* NLA_NESTED Don't use `len' field -- length verification is
* done by checking len of nested header (or empty)
* NLA_NESTED_COMPAT Minimum length of structure payload
* NLA_U8, NLA_U16,
* NLA_U32, NLA_U64,
* NLA_MSECS Leaving the length field zero will verify the
* given type fits, using it verifies minimum length
* just like "All other"
* All other Minimum length of attribute payload
*
* Example:
* static const struct nla_policy my_policy[ATTR_MAX+1] = {