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

-----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 <redacted>
---
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