From 3b33c1abf8bf3fb60c1125382de1da57d823d785 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Mon, 7 Jun 2010 11:13:03 -0300 Subject: [PATCH 3/6] virtio-net: truncating packet RH-Author: Michael S. Tsirkin Message-id: <20100607111303.GA6264@redhat.com> Patchwork-id: 9738 O-Subject: [RHEL6.0 PATCHv3] virtio-net: truncating packet Bugzilla: 591494 RH-Acked-by: Amit Shah RH-Acked-by: Juan Quintela RH-Acked-by: Jes Sorensen virtio net attempts to peek into virtio queue to determine that we have enough space for the complete packet to fit. However, it fails to account for space consumed by virtio net header when it does this, under stress this results in a failure with the message 'truncating packet'. redhat bz 591494. Signed-off-by: Michael S. Tsirkin Upstream status: posted Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=591494 Brew build: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=2497427 v2 was posted mistakenly, is was identical to v1. v3 really tweaks whitespace as suggested by Amit. Sorry about the noise. --- hw/virtio-net.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) Signed-off-by: Eduardo Habkost --- hw/virtio-net.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index 67eebcf..4b677b9 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -532,16 +532,17 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_ if (!virtio_net_can_receive(&n->nic->nc)) return -1; - if (!virtio_net_has_buffers(n, size)) + /* hdr_len refers to the header we supply to the guest */ + hdr_len = n->mergeable_rx_bufs ? + sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); + + + if (!virtio_net_has_buffers(n, size + hdr_len)) return 0; if (!receive_filter(n, buf, size)) return size; - /* hdr_len refers to the header we supply to the guest */ - hdr_len = n->mergeable_rx_bufs ? - sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr); - offset = i = 0; while (offset < size) { @@ -555,7 +556,9 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_ virtqueue_pop(n->rx_vq, &elem) == 0) { if (i == 0) return -1; - fprintf(stderr, "virtio-net truncating packet\n"); + fprintf(stderr, "virtio-net truncating packet: " + "offset %zd, size %zd, hdr_len %zd\n", + offset, size, hdr_len); exit(1); } -- 1.7.0.3