[dpdk-dev] [PATCH] lib/lpm:fix two issues in the delete_depth_small()

[Nikita Kozlov]

On 10/28/2015 03:40 PM, Bruce Richardson wrote:
> On Wed, Oct 28, 2015 at 11:44:15AM +0800, Jijiang Liu wrote:
>> Fix two issues in the delete_depth_small() function.
>>  
>> 1> The control is not strict in this function.
>>  
>> In the following structure,
>> struct rte_lpm_tbl24_entry {
>>         union {
>>                 uint8_t next_hop;
>>                 uint8_t tbl8_gindex;
>>         };
>>      uint8_t ext_entry :1;
>> }
>>  
>> When ext_entry = 0, use next_hop.only to process rte_lpm_tbl24_entry.
>>  
>> When ext_entry = 1, use tbl8_gindex to process the rte_lpm_tbl8_entry.
>>  
>> When using LPM24 + 8 algorithm, it will use ext_entry to decide to process rte_lpm_tbl24_entry structure or rte_lpm_tbl8_entry structure. 
>> If a route is deleted, the prefix of previous route is used to override the deleted route. when (lpm->tbl24[i].ext_entry == 0 && lpm->tbl24[i].depth > depth) 
>> it should be ignored, but due to the incorrect logic, the next_hop is used as tbl8_gindex and will process the rte_lpm_tbl8_entry.
>>  
>> 2> Initialization of rte_lpm_tbl8_entry is incorrect in this function 
>>  
>> In this function, use new rte_lpm_tbl8_entry we call A to replace the old rte_lpm_tbl8_entry. But the valid_group do not set VALID, so it will be INVALID.
>> Then when adding a new route which depth is > 24,the tbl8_alloc() function will search the rte_lpm_tbl8_entrys to find INVALID valid_group, 
>> and it will return the A to the add_depth_big function, so A's data is overridden.
>>
>> Signed-off-by: NaNa <nana.nn at alibaba-inc.com>
>>
> Hi NaNa, Jijiang,
>
> since this patch contains two separate fixes, it would be better split into
> two separate patches, one for each fix. Also, please add a "Fixes" line to
> the commit log.
>
> Are there still plans for a unit test to demonstrate the bug(s) and make it easy
> for us to verify the fix?
>
> Regards,
> /Bruce
Hello,

It's the same fix as the one sent here (which contained some tests,
maybe we can use them ?)
http://dpdk.org/ml/archives/dev/2015-October/025871.html .
For what is worth, we are using those fix at my company and they are
fixing the described bug.

-- 
Nikita