Signed-off-by: Wei Xu <w...@redhat.com>
---
hw/net/virtio-net.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 124 insertions(+), 1 deletion(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 7a6cd4c..d005a56 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -41,6 +41,10 @@
#define VIRTIO_HEADER 12 /* Virtio net header size */
#define IP_OFFSET (VIRTIO_HEADER + sizeof(struct eth_header))
+#define TCP_WINDOW 65535
+
+/* ip4 max payload, 16 bits in the header */
+#define MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header))
#define MAX_VIRTIO_IP_PAYLOAD (65535 + IP_OFFSET)
@@ -1670,11 +1674,130 @@ out:
return 0;
}
+static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain, NetRscSeg *seg,
+ const uint8_t *buf, struct tcp_header *n_tcp,
+ struct tcp_header *o_tcp)
+{
+ uint32_t nack, oack;
+ uint16_t nwin, owin;
+
+ nack = htonl(n_tcp->th_ack);
+ nwin = htons(n_tcp->th_win);
+ oack = htonl(o_tcp->th_ack);
+ owin = htons(o_tcp->th_win);
+
+ if ((nack - oack) >= TCP_WINDOW) {
+ return RSC_FINAL;
+ } else if (nack == oack) {
+ /* duplicated ack or window probe */
+ if (nwin == owin) {
+ /* duplicated ack, add dup ack count due to whql test up to 1 */
+
+ if (seg->dup_ack_count == 0) {
+ seg->dup_ack_count++;
+ return RSC_COALESCE;
+ } else {
+ /* Spec says should send it directly */
+ return RSC_FINAL;
+ }
+ } else {
+ /* Coalesce window update */
+ o_tcp->th_win = n_tcp->th_win;
+ return RSC_COALESCE;
+ }
+ } else {
+ /* pure ack, update ack */
+ o_tcp->th_ack = n_tcp->th_ack;
+ return RSC_COALESCE;
+ }
+}
+
+static int32_t virtio_net_rsc_coalesce_tcp(NetRscChain *chain, NetRscSeg *seg,
+ const uint8_t *buf, struct tcp_header *n_tcp, uint16_t
n_tcp_len,
+ uint16_t n_data, struct tcp_header *o_tcp, uint16_t o_tcp_len,
+ uint16_t o_data, uint16_t *p_ip_len, uint16_t max_data)
+{
+ void *data;
+ uint16_t o_ip_len;
+ uint32_t nseq, oseq;
+
+ o_ip_len = htons(*p_ip_len);
+ nseq = htonl(n_tcp->th_seq);
+ oseq = htonl(o_tcp->th_seq);
+
+ /* Ignore packet with more/larger tcp options */
+ if (n_tcp_len > o_tcp_len) {
+ return RSC_FINAL;
+ }
+
+ /* out of order or retransmitted. */
+ if ((nseq - oseq) > TCP_WINDOW) {
+ return RSC_FINAL;
+ }
+
+ data = ((uint8_t *)n_tcp) + n_tcp_len;
+ if (nseq == oseq) {
+ if ((0 == o_data) && n_data) {
+ /* From no payload to payload, normal case, not a dup ack or etc */
+ goto coalesce;
+ } else {
+ return virtio_net_rsc_handle_ack(chain, seg, buf, n_tcp, o_tcp);
+ }
+ } else if ((nseq - oseq) != o_data) {
+ /* Not a consistent packet, out of order */
+ return RSC_FINAL;
+ } else {
+coalesce:
+ if ((o_ip_len + n_data) > max_data) {
+ return RSC_FINAL;
+ }
+
+ /* Here comes the right data, the payload lengh in v4/v6 is different,
+ so use the field value to update */
+ *p_ip_len = htons(o_ip_len + n_data); /* Update new data len */
+ o_tcp->th_offset_flags = n_tcp->th_offset_flags; /* Bring 'PUSH' big */
+ o_tcp->th_ack = n_tcp->th_ack;
+ o_tcp->th_win = n_tcp->th_win;
+
+ memmove(seg->buf + seg->size, data, n_data);
+ seg->size += n_data;
+ return RSC_COALESCE;
+ }
+}
static int32_t virtio_net_rsc_try_coalesce4(NetRscChain *chain,
NetRscSeg *seg, const uint8_t *buf, size_t size)
{
- return RSC_FINAL;
+ uint16_t o_ip_len, n_ip_len; /* len in ip header field */
+ uint16_t n_ip_hdrlen, o_ip_hdrlen; /* ipv4 header len */
+ uint16_t n_tcp_len, o_tcp_len; /* tcp header len */
+ uint16_t o_data, n_data; /* payload without virtio/eth/ip/tcp */
+ struct ip_header *n_ip, *o_ip;
+ struct tcp_header *n_tcp, *o_tcp;
+
+ n_ip = (struct ip_header *)(buf + IP_OFFSET);
+ n_ip_hdrlen = ((0xF & n_ip->ip_ver_len) << 2);
+ n_ip_len = htons(n_ip->ip_len);
+ n_tcp = (struct tcp_header *)(((uint8_t *)n_ip) + n_ip_hdrlen);
+ n_tcp_len = (htons(n_tcp->th_offset_flags) & 0xF000) >> 10;
+ n_data = n_ip_len - n_ip_hdrlen - n_tcp_len;
+
+ o_ip = (struct ip_header *)(seg->buf + IP_OFFSET);
+ o_ip_hdrlen = ((0xF & o_ip->ip_ver_len) << 2);
+ o_ip_len = htons(o_ip->ip_len);
+ o_tcp = (struct tcp_header *)(((uint8_t *)o_ip) + o_ip_hdrlen);
+ o_tcp_len = (htons(o_tcp->th_offset_flags) & 0xF000) >> 10;
+ o_data = o_ip_len - o_ip_hdrlen - o_tcp_len;
+
+ if ((n_ip->ip_src ^ o_ip->ip_src) || (n_ip->ip_dst ^ o_ip->ip_dst)
+ || (n_tcp->th_sport ^ o_tcp->th_sport)
+ || (n_tcp->th_dport ^ o_tcp->th_dport)) {
+ return RSC_NO_MATCH;
+ }
+
+ return virtio_net_rsc_coalesce_tcp(chain, seg, buf,
+ n_tcp, n_tcp_len, n_data, o_tcp, o_tcp_len,
+ o_data, &o_ip->ip_len, MAX_IP4_PAYLOAD);
}
static size_t virtio_net_rsc_callback(NetRscChain *chain, NetClientState *nc,
--
2.4.0
