xsk: Improve xdp_do_redirect() error codes

The error codes returned by xdp_do_redirect() when redirecting a frame to an AF_XDP socket has not been very useful. A driver could not distinguish between different errors. Prior this change the following codes where used: Socket not bound or incorrect queue/netdev: EINVAL XDP frame/AF_XDP buffer size mismatch: ENOSPC Could not allocate buffer (copy mode): ENOSPC AF_XDP Rx buffer full: ENOSPC After this change: Socket not bound or incorrect queue/netdev: EINVAL XDP frame/AF_XDP buffer size mismatch: ENOSPC Could not allocate buffer (copy mode): ENOMEM AF_XDP Rx buffer full: ENOBUFS An AF_XDP zero-copy driver can now potentially determine if the failure was due to a full Rx buffer, and if so stop processing more frames, yielding to the userland AF_XDP application. Signed-off-by: Björn Töpel <[email protected]> Signed-off-by: Maciej Fijalkowski <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Jesper Dangaard Brouer <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
majek · Apr 15, 2022 · c6c1f11 · c6c1f11
1 parent 241d50e
commit c6c1f11
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
@@ -184,7 +184,7 @@ static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 	xsk_xdp = xsk_buff_alloc(xs->pool);
 	if (!xsk_xdp) {
 		xs->rx_dropped++;
-		return -ENOSPC;
+		return -ENOMEM;
 	}
 
 	xsk_copy_xdp(xsk_xdp, xdp, len);

diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
@@ -382,7 +382,7 @@ static inline int xskq_prod_reserve_desc(struct xsk_queue *q,
 	u32 idx;
 
 	if (xskq_prod_is_full(q))
-		return -ENOSPC;
+		return -ENOBUFS;
 
 	/* A, matches D */
 	idx = q->cached_prod++ & q->ring_mask;