[ovs-dev] [PATCH 1/4] odp-util: Correctly generate wildcards when formating nested attributes.

[Jesse Gross]

On Wed, May 27, 2015 at 3:03 PM, Andy Zhou <azhou at nicira.com> wrote:
> On Wed, May 27, 2015 at 10:48 AM, Jesse Gross <jesse at nicira.com> wrote:
>> When formatting netlink attributes if no mask is present a wildcarded
>> attribute is synthesized for the purposes of later processing. In
>> the case of nested attributes this must be done recursively, filling
>> in the correct attributes at each level rather than just generating
>> a set of zeros of the correct size. This is done already but it
>> always uses the attribute type for the top level keys - this corresponds
>> to nested ENCAP attributes. However, we have several levels of potentially
>> nested attributes for tunnels that each have their own types.
>>
>> This uses an approach similar to the kernel where we have sets of
>> tables for the type of each attribute linked together by pointers.
>> This allows the mask generation function to automatically traverse
>> the nested attributes and always get the right types.
>>
>> Signed-off-by: Jesse Gross <jesse at nicira.com>
>> ---
>>  lib/odp-util.c | 151 ++++++++++++++++++++++++++++++++-------------------------
>>  1 file changed, 86 insertions(+), 65 deletions(-)
>>
>> diff --git a/lib/odp-util.c b/lib/odp-util.c
>> index 4845d28..09a1ff2 100644
>> --- a/lib/odp-util.c
>> +++ b/lib/odp-util.c
>> @@ -1208,45 +1208,73 @@ odp_actions_from_string(const char *s, const struct simap *port_names,
>>      return 0;
>>  }
>>
>> +
>> +struct attr_len_tbl {
>> +    int len;
>> +    const struct attr_len_tbl *next;
>> +    int next_max;
>> +};
>> +#define ATTR_LEN_VARIABLE -2
>> +#define ATTR_LEN_NESTED   -3
>> +
>
> Might be nice to also '#define ATTR_LEN_INVALID -1' for completeness.
> Although it is expected to be used in
> tables, but only a possible return value from function calls,
>
> There are still a few places '-2' are hard coded, including some
> comments. It might be nice to change them those as well.

Thanks, I think these are both good suggestions for consistency so I
made those changes.