In the vhost-user paths, the buffers provided by the virtio queue
include the virtio net header (VNET_HLEN) prepended to the Ethernet
frame. The minimum size checks using ETH_ZLEN must therefore account
for this additional header length, otherwise we underestimate the
minimum buffer size needed.
Use ETH_ZLEN + VNET_HLEN instead of bare ETH_ZLEN in vu_collect()
calls and the corresponding ASSERT() checks.
Fixes: 0cb8f9003654 ("tcp, udp: Pad batched frames for vhost-user modes to 60 bytes (802.3 minimum)")
Signed-off-by: Laurent Vivier
---
tcp_vu.c | 8 ++++----
udp_vu.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/tcp_vu.c b/tcp_vu.c
index f7bda4943e43..2d593d534d68 100644
--- a/tcp_vu.c
+++ b/tcp_vu.c
@@ -90,12 +90,12 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags)
vu_set_element(&flags_elem[0], NULL, &flags_iov[0]);
elem_cnt = vu_collect(vdev, vq, &flags_elem[0], 1,
- MAX(hdrlen + sizeof(*opts), ETH_ZLEN), NULL);
+ MAX(hdrlen + sizeof(*opts), ETH_ZLEN + VNET_HLEN), NULL);
if (elem_cnt != 1)
return -1;
ASSERT(flags_elem[0].in_sg[0].iov_len >=
- MAX(hdrlen + sizeof(*opts), ETH_ZLEN));
+ MAX(hdrlen + sizeof(*opts), ETH_ZLEN + VNET_HLEN));
vu_set_vnethdr(vdev, flags_elem[0].in_sg[0].iov_base, 1);
@@ -208,7 +208,7 @@ static ssize_t tcp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq,
cnt = vu_collect(vdev, vq, &elem[elem_cnt],
VIRTQUEUE_MAX_SIZE - elem_cnt,
- MAX(MIN(mss, fillsize) + hdrlen, ETH_ZLEN),
+ MAX(MIN(mss, fillsize) + hdrlen, ETH_ZLEN + VNET_HLEN),
&frame_size);
if (cnt == 0)
break;
@@ -302,7 +302,7 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn,
/* we guess the first iovec provided by the guest can embed
* all the headers needed by L2 frame, including any padding
*/
- ASSERT(iov[0].iov_len >= MAX(hdrlen, ETH_ZLEN));
+ ASSERT(iov[0].iov_len >= MAX(hdrlen, ETH_ZLEN + VNET_HLEN));
eh = vu_eth(base);
diff --git a/udp_vu.c b/udp_vu.c
index 4f1eac48d162..d190fef82d49 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -97,7 +97,7 @@ static int udp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq, int s,
return -1;
/* reserve space for the headers */
- ASSERT(iov_vu[0].iov_len >= MAX(hdrlen, ETH_ZLEN));
+ ASSERT(iov_vu[0].iov_len >= MAX(hdrlen, ETH_ZLEN + VNET_HLEN));
iov_vu[0].iov_base = (char *)iov_vu[0].iov_base + hdrlen;
iov_vu[0].iov_len -= hdrlen;
--
2.52.0