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

[Bruce Richardson]

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