[PATCH v4 bpf-next 09/22] xsk: discard zero length descriptors in Tx path

[Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>]

From: Tirthendu Sarkar <tirthendu.sarkar@xxxxxxxxx>

Descriptors with zero length are not supported by many NICs. To preserve
uniform behavior discard any zero length desc as invvalid desc.

Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@xxxxxxxxx>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
---
 net/xdp/xsk_queue.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 2d2af9fc2744..ab0d13d6d90e 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -140,6 +140,9 @@ static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
 {
 	u64 offset = desc->addr & (pool->chunk_size - 1);
 
+	if (!desc->len)
+		return false;
+
 	if (offset + desc->len > pool->chunk_size)
 		return false;
 
@@ -156,6 +159,9 @@ static inline bool xp_unaligned_validate_desc(struct xsk_buff_pool *pool,
 {
 	u64 addr = xp_unaligned_add_offset_to_addr(desc->addr);
 
+	if (!desc->len)
+		return false;
+
 	if (desc->len > pool->chunk_size)
 		return false;
 
-- 
2.34.1