tcp_fill_headers() computed the TCP payload length from iov_tail_size(),
but with vhost-user multibuffer frames, the iov_tail will be larger than
the actual data. Pass the data length explicitly so that IP total
length, pseudo-header, and checksum computations use the correct value.
Signed-off-by: Laurent Vivier
Reviewed-by: David Gibson
---
tcp.c | 4 ++--
tcp_buf.c | 3 ++-
tcp_internal.h | 2 +-
tcp_vu.c | 9 +++++----
4 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/tcp.c b/tcp.c
index 5b2a732cf26d..45bcc19375fe 100644
--- a/tcp.c
+++ b/tcp.c
@@ -945,6 +945,7 @@ static void tcp_fill_header(struct tcphdr *th,
* @ip6h: Pointer to IPv6 header, or NULL
* @th: Pointer to TCP header
* @payload: TCP payload
+ * @dlen: TCP payload length
* @ip4_check: IPv4 checksum, if already known
* @seq: Sequence number for this segment
* @no_tcp_csum: Do not set TCP checksum
@@ -955,11 +956,10 @@ size_t tcp_fill_headers(const struct ctx *c, struct tcp_tap_conn *conn,
struct ethhdr *eh,
struct iphdr *ip4h, struct ipv6hdr *ip6h,
struct tcphdr *th, struct iov_tail *payload,
- const uint16_t *ip4_check, uint32_t seq,
+ size_t dlen, const uint16_t *ip4_check, uint32_t seq,
bool no_tcp_csum)
{
const struct flowside *tapside = TAPFLOW(conn);
- size_t dlen = iov_tail_size(payload);
size_t l4len = dlen + sizeof(*th);
uint8_t *omac = conn->f.tap_omac;
size_t l3len = l4len;
diff --git a/tcp_buf.c b/tcp_buf.c
index 41965b107567..27151854033c 100644
--- a/tcp_buf.c
+++ b/tcp_buf.c
@@ -190,7 +190,8 @@ static void tcp_l2_buf_fill_headers(const struct ctx *c,
else
ip6h = iov[TCP_IOV_IP].iov_base;
- l2len = tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &tail, check, seq,
+ l2len = tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &tail,
+ iov_tail_size(&tail), check, seq,
no_tcp_csum);
tap_hdr_update(taph, l2len);
}
diff --git a/tcp_internal.h b/tcp_internal.h
index d9408852571f..a0fa19f4ed11 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -187,7 +187,7 @@ size_t tcp_fill_headers(const struct ctx *c, struct tcp_tap_conn *conn,
struct ethhdr *eh,
struct iphdr *ip4h, struct ipv6hdr *ip6h,
struct tcphdr *th, struct iov_tail *payload,
- const uint16_t *ip4_check, uint32_t seq,
+ size_t dlen, const uint16_t *ip4_check, uint32_t seq,
bool no_tcp_csum);
int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
diff --git a/tcp_vu.c b/tcp_vu.c
index 4eba7b8a5190..8c1894dca7fe 100644
--- a/tcp_vu.c
+++ b/tcp_vu.c
@@ -136,7 +136,7 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags)
seq--;
tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &payload,
- NULL, seq, !*c->pcap);
+ optlen, NULL, seq, !*c->pcap);
vu_pad(&flags_elem[0].in_sg[0], l2len);
@@ -280,12 +280,13 @@ static ssize_t tcp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq,
* @conn: Connection pointer
* @iov: Pointer to the array of IO vectors
* @iov_cnt: Number of entries in @iov
+ * @dlen: Data length
* @check: Checksum, if already known
* @no_tcp_csum: Do not set TCP checksum
* @push: Set PSH flag, last segment in a batch
*/
static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn,
- struct iovec *iov, size_t iov_cnt,
+ struct iovec *iov, size_t iov_cnt, size_t dlen,
const uint16_t **check, bool no_tcp_csum, bool push)
{
const struct flowside *toside = TAPFLOW(conn);
@@ -329,7 +330,7 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn,
th->ack = 1;
th->psh = push;
- tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &payload,
+ tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &payload, dlen,
*check, conn->seq_to_tap, no_tcp_csum);
if (ip4h)
*check = &ip4h->check;
@@ -457,7 +458,7 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn)
check = NULL;
previous_dlen = dlen;
- tcp_vu_prepare(c, conn, iov, buf_cnt, &check, !*c->pcap, push);
+ tcp_vu_prepare(c, conn, iov, buf_cnt, dlen, &check, !*c->pcap, push);
/* Pad first/single buffer only, it's at least ETH_ZLEN long */
l2len = dlen + hdrlen - VNET_HLEN;
--
2.53.0