Currently tap_send_frames() expects the frames it is given to include the
vnet_len field, even in pasta mode which doesn't use it (although it need
not be initialized in that case). To match, tap_iov_base() and
tap_iov_len() construct the frame in that way.
This will inconvenience future changes, so alter things to set the buffers
to include just the frame needed by the tap backend type.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
tap.c | 5 ++---
tap.h | 6 ++++--
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/tap.c b/tap.c
index d0dd72c..5ec6b70 100644
--- a/tap.c
+++ b/tap.c
@@ -317,8 +317,7 @@ static void tap_send_frames_pasta(struct ctx *c,
size_t i;
for (i = 0; i < n; i++) {
- if (write(c->fd_tap, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0) {
+ if (write(c->fd_tap, (char *)iov->iov_base, iov->iov_len) < 0) {
debug("tap write: %s", strerror(errno));
if (errno != EAGAIN && errno != EWOULDBLOCK)
tap_handler(c, c->fd_tap, EPOLLERR, NULL);
@@ -383,7 +382,7 @@ void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t
n)
else
tap_send_frames_pasta(c, iov, n);
- pcap_multiple(iov, n, sizeof(uint32_t));
+ pcap_multiple(iov, n, c->mode == MODE_PASST ? sizeof(uint32_t) : 0);
}
/**
diff --git a/tap.h b/tap.h
index 8fe460a..40cf480 100644
--- a/tap.h
+++ b/tap.h
@@ -20,8 +20,10 @@ struct tap_hdr {
static inline size_t tap_hdr_len_(const struct ctx *c)
{
- (void)c;
- return sizeof(struct tap_hdr);
+ if (c->mode == MODE_PASST)
+ return sizeof(struct tap_hdr);
+ else
+ return sizeof(struct ethhdr);
}
/**
--
2.38.1