[Qemu-devel] [RFC PATCH V3 2/3] filter-rewriter: track connection and parse packet

[Zhang Chen]

We use colo-base.h to track connection and parse packet

Signed-off-by: Zhang Chen <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Signed-off-by: Wen Congyang <address@hidden>
---
 net/filter-rewriter.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
index c4f2739..7f0da2c 100644
--- a/net/filter-rewriter.c
+++ b/net/filter-rewriter.c
@@ -48,6 +48,20 @@ typedef struct RewriterState {
     uint32_t hashtable_size;
 } RewriterState;
 
+/*
+ * Return 1 on success, if return 0 means the pkt
+ * is not TCP packet
+ */
+static int is_tcp_packet(Packet *pkt)
+{
+    if (!parse_packet_early(pkt) &&
+        pkt->ip->ip_p == IPPROTO_TCP) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
 static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
                                          NetClientState *sender,
                                          unsigned flags,
@@ -55,11 +69,47 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
                                          int iovcnt,
                                          NetPacketSent *sent_cb)
 {
+    RewriterState *s = FILTER_COLO_REWRITER(nf);
+    Connection *conn;
+    ConnectionKey key = {{ 0 } };
+    Packet *pkt;
+    ssize_t size = iov_size(iov, iovcnt);
+    char *buf = g_malloc0(size);
+
+    iov_to_buf(iov, iovcnt, 0, buf, size);
+    pkt = packet_new(buf, size);
+
     /*
      * if we get tcp packet
      * we will rewrite it to make secondary guest's
      * connection established successfully
      */
+    if (is_tcp_packet(pkt)) {
+        if (sender == nf->netdev) {
+            fill_connection_key(pkt, &key, SECONDARY);
+        } else {
+            fill_connection_key(pkt, &key, PRIMARY);
+        }
+
+        conn = connection_get(s->connection_track_table,
+                              &key,
+                              &s->hashtable_size);
+        if (!conn->processing) {
+            g_queue_push_tail(&s->conn_list, conn);
+            conn->processing = true;
+        }
+
+        if (sender == nf->netdev) {
+            /* NET_FILTER_DIRECTION_TX */
+            /* handle_primary_tcp_pkt */
+        } else {
+            /* NET_FILTER_DIRECTION_RX */
+            /* handle_secondary_tcp_pkt */
+        }
+    }
+
+    packet_destroy(pkt, NULL);
+    pkt = NULL;
     return 0;
 }
 
-- 
2.7.4