Re: [PATCH 1/3] libnl: add netfilter support

[Philip Craig <philipc@snapgear.com>]

Thomas Graf wrote:
> * Philip Craig <philipc@snapgear.com> 2007-09-03 15:11
>> Index: libnl/lib/attr.c
>> ===================================================================
>> --- libnl.orig/lib/attr.c	2007-09-03 14:24:29.000000000 +1000
>> +++ libnl/lib/attr.c	2007-09-03 14:24:45.000000000 +1000
>> @@ -261,7 +261,8 @@ int nla_parse(struct nlattr *tb[], int m
>>  	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
>>  
>>  	nla_for_each_attr(nla, head, len, rem) {
>> -		uint16_t type = nla->nla_type;
>> +		/* Ignore NFNL_NFA_NEST bit, hope nothing else uses it */
>> +		uint16_t type = nla->nla_type & 0x7fff;
> 
> I wonder if it is useful to make this behaviour conditional so that
> the netfilter subsystem could enable this for backwards compatibility
> while other subsystems won't be affected.
> 
> It will offend a few people but it's still pre 1.0 and we can break
> the API. I'd rather get this right now than having to life with
> side effects for a long time.

Yes it would be nice to only do it for subsystems that need it.
The only place I can see in the existing arguments for nla_parse()
is to overload the meaning of the unused policy[0]. The other options
are to change nla_parse() or add nla_parse_masked(). Any preference?