Re: [dpdk-dev] [PATCH v2] lpm: fix extended flag check when adding a "depth small" entry

["Liang, Cunming" <cunming.liang@intel.com>]

> -----Original Message-----
> From: Tao, Zhe
> Sent: Thursday, July 30, 2015 11:19 AM
> To: dev@dpdk.org
> Cc: Tao, Zhe; Liang, Cunming; Richardson, Bruce
> Subject: [dpdk-dev][PATCH v2] lpm: fix extended flag check when adding a
> "depth small" entry
> 
> When adding a "depth small" entry, if its extended flag is not set and
> its depth is smaller than the one in the tbl24, nothing should be done
> otherwise will operate on the wrong memory area.
> 
> Signed-off-by: Zhe Tao <zhe.tao@intel.com>
> ---
> PATCH v2: Edit to keep line size below 80 characters
> 
> PATCH v1: Fix extended flag check when adding a "depth small" entry
> 
>  lib/librte_lpm/rte_lpm.c | 54 +++++++++++++++++++++++++++-------------------
> --
>  1 file changed, 30 insertions(+), 24 deletions(-)
> 
> diff --git a/lib/librte_lpm/rte_lpm.c b/lib/librte_lpm/rte_lpm.c
> index de05307..163ba3c 100644
> --- a/lib/librte_lpm/rte_lpm.c
> +++ b/lib/librte_lpm/rte_lpm.c
> @@ -442,35 +442,41 @@ add_depth_small(struct rte_lpm *lpm, uint32_t ip,
> uint8_t depth,
>  			};
> 
>  			/* Setting tbl24 entry in one go to avoid race
> -			 * conditions */
> +			 * conditions
> +			 */
>  			lpm->tbl24[i] = new_tbl24_entry;
> 
>  			continue;
>  		}
> 
> -		/* If tbl24 entry is valid and extended calculate the index
> -		 * into tbl8. */
> -		tbl8_index = lpm->tbl24[i].tbl8_gindex *
> -				RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
> -		tbl8_group_end = tbl8_index +
> RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
> -
> -		for (j = tbl8_index; j < tbl8_group_end; j++) {
> -			if (!lpm->tbl8[j].valid ||
> -					lpm->tbl8[j].depth <= depth) {
> -				struct rte_lpm_tbl8_entry new_tbl8_entry = {
> -					.valid = VALID,
> -					.valid_group = VALID,
> -					.depth = depth,
> -					.next_hop = next_hop,
> -				};
> -
> -				/*
> -				 * Setting tbl8 entry in one go to avoid race
> -				 * conditions
> -				 */
> -				lpm->tbl8[j] = new_tbl8_entry;
> -
> -				continue;
> +		if (lpm->tbl24[i].ext_entry == 1) {
> +			/* If tbl24 entry is valid and extended calculate the
> +			 *  index into tbl8.
> +			 */
> +			tbl8_index = lpm->tbl24[i].tbl8_gindex *
> +					RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
> +			tbl8_group_end = tbl8_index +
> +					RTE_LPM_TBL8_GROUP_NUM_ENTRIES;
> +
> +			for (j = tbl8_index; j < tbl8_group_end; j++) {
> +				if (!lpm->tbl8[j].valid ||
> +						lpm->tbl8[j].depth <= depth) {
> +					struct rte_lpm_tbl8_entry
> +						new_tbl8_entry = {
> +						.valid = VALID,
> +						.valid_group = VALID,
> +						.depth = depth,
> +						.next_hop = next_hop,
> +					};
> +
> +					/*
> +					 * Setting tbl8 entry in one go to avoid
> +					 * race conditions
> +					 */
> +					lpm->tbl8[j] = new_tbl8_entry;
> +
> +					continue;
> +				}
>  			}
>  		}
>  	}
> --
> 1.9.3

Acked-by: Cunming Liang <cunming.liang@intel.com>