[dpdk-dev] [PATCH] librte_lpm: use field access instead of type conversion.

[<xuelin.shi@freescale.com>]

From: Xuelin Shi <xuelin.shi@freescale.com>

struct tbl_entry{
        uint8_t next_hop;
        uint8_t valid :1;
        uint8_t valid_group :1;
        uint8_t depth :6
}
uint16_t tbl = (uint16_t)tbl_entry;
next_hop = (uint8_t)tbl;

next_hop cannot get the correct value of the field
if the cpu arch is BIG_ENDIAN.

change it to field access.

Signed-off-by: Xuelin Shi <xuelin.shi@freescale.com>
---
 lib/librte_lpm/rte_lpm.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/librte_lpm/rte_lpm.h b/lib/librte_lpm/rte_lpm.h
index 586300b..1af150c 100644
--- a/lib/librte_lpm/rte_lpm.h
+++ b/lib/librte_lpm/rte_lpm.h
@@ -273,6 +273,7 @@ rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
 {
 	unsigned tbl24_index = (ip >> 8);
 	uint16_t tbl_entry;
+	struct rte_lpm_tbl8_entry *entry;
 
 	/* DEBUG: Check user input arguments. */
 	RTE_LPM_RETURN_IF_TRUE(((lpm == NULL) || (next_hop == NULL)), -EINVAL);
@@ -290,8 +291,10 @@ rte_lpm_lookup(struct rte_lpm *lpm, uint32_t ip, uint8_t *next_hop)
 		tbl_entry = *(const uint16_t *)&lpm->tbl8[tbl8_index];
 	}
 
-	*next_hop = (uint8_t)tbl_entry;
-	return (tbl_entry & RTE_LPM_LOOKUP_SUCCESS) ? 0 : -ENOENT;
+	entry = (struct rte_lpm_tbl8_entry *)&tbl_entry;
+	*next_hop = entry->next_hop;
+
+	return (entry->valid) ? 0 : -ENOENT;
 }
 
 /**
-- 
1.9.1