From: Wei Xu <w...@redhat.com>
All the 'SYN' packets will be bypassed, and flag with 'FIN/RST' set
will signal all the cached packets in the same connection to be purged,
this is to avoid out of data on the line.
Signed-off-by: Wei Xu <w...@redhat.com>
---
hw/net/virtio-net.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 1ca3dd5..042b538 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -41,6 +41,12 @@
#define VIRTIO_HEADER 12 /* Virtio net header size */
#define IP_OFFSET (VIRTIO_HEADER + sizeof(struct eth_header))
+
+#define IP4_ADDR_OFFSET (IP_OFFSET + 12) /* ipv4 address start */
+#define TCP4_OFFSET (IP_OFFSET + sizeof(struct ip_header)) /* tcp4 header */
+#define TCP4_PORT_OFFSET TCP4_OFFSET /* tcp4 port offset */
+#define IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */
+#define TCP_PORT_SIZE 4 /* sport + dport */
#define TCP_WINDOW 65535
/* ip4 max payload, 16 bits in the header */
@@ -1850,6 +1856,27 @@ static int32_t virtio_net_rsc_try_coalesce4(NetRscChain
*chain,
o_data, &o_ip->ip_len, MAX_IP4_PAYLOAD);
}
+
+/* Pakcets with 'SYN' should bypass, other flag should be sent after drain
+ * to prevent out of order */
+static int virtio_net_rsc_parse_tcp_ctrl(uint8_t *ip, uint16_t offset)
+{
+ uint16_t tcp_flag;
+ struct tcp_header *tcp;
+
+ tcp = (struct tcp_header *)(ip + offset);
+ tcp_flag = htons(tcp->th_offset_flags) & 0x3F;
+ if (tcp_flag & TH_SYN) {
+ return RSC_BYPASS;
+ }
+
+ if (tcp_flag & (TH_FIN | TH_URG | TH_RST)) {
+ return RSC_FINAL;
+ }
+
+ return 0;
+}
+
static size_t virtio_net_rsc_callback(NetRscChain *chain, NetClientState *nc,
const uint8_t *buf, size_t size, VirtioNetCoalesce *coalesce)
{
@@ -1895,12 +1922,51 @@ static size_t virtio_net_rsc_callback(NetRscChain
*chain, NetClientState *nc,
return virtio_net_rsc_cache_buf(chain, nc, buf, size);
}
+/* Drain a connection data, this is to avoid out of order segments */
+static size_t virtio_net_rsc_drain_one(NetRscChain *chain, NetClientState *nc,
+ const uint8_t *buf, size_t size, uint16_t ip_start,
+ uint16_t ip_size, uint16_t tcp_port, uint16_t port_size)
+{
+ NetRscSeg *seg, *nseg;
+
+ QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
+ if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size)
+ || memcmp(buf + tcp_port, seg->buf + tcp_port, port_size)) {
+ continue;
+ }
+ if ((chain->proto == ETH_P_IP) && seg->is_coalesced) {
+ virtio_net_rsc_ipv4_checksum(seg);
+ }
+
+ virtio_net_do_receive(seg->nc, seg->buf, seg->size);
+
+ QTAILQ_REMOVE(&chain->buffers, seg, next);
+ g_free(seg->buf);
+ g_free(seg);
+ break;
+ }
+
+ return virtio_net_do_receive(nc, buf, size);
+}
static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc,
const uint8_t *buf, size_t size)
{
+ int32_t ret;
+ struct ip_header *ip;
NetRscChain *chain;
chain = (NetRscChain *)opq;
+ ip = (struct ip_header *)(buf + IP_OFFSET);
+
+ ret = virtio_net_rsc_parse_tcp_ctrl((uint8_t *)ip,
+ (0xF & ip->ip_ver_len) << 2);
+ if (RSC_BYPASS == ret) {
+ return virtio_net_do_receive(nc, buf, size);
+ } else if (RSC_FINAL == ret) {
+ return virtio_net_rsc_drain_one(chain, nc, buf, size, IP4_ADDR_OFFSET,
+ IP4_ADDR_SIZE, TCP4_PORT_OFFSET,
TCP_PORT_SIZE);
+ }
+
return virtio_net_rsc_callback(chain, nc, buf, size,
virtio_net_rsc_try_coalesce4);
}
--
2.4.0
