1 files changed, 110 insertions, 2 deletions

diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
index 9bf80d3955..89abe72d4e 100644
--- a/net/filter-rewriter.c
+++ b/net/filter-rewriter.c
@@ -10,6 +10,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "trace.h"
 #include "net/colo.h"
 #include "net/filter.h"
 #include "net/net.h"
@@ -58,6 +59,93 @@ static int is_tcp_packet(Packet *pkt)
     }
 }
 
+/* handle tcp packet from primary guest */
+static int handle_primary_tcp_pkt(NetFilterState *nf,
+                                  Connection *conn,
+                                  Packet *pkt)
+{
+    struct tcphdr *tcp_pkt;
+
+    tcp_pkt = (struct tcphdr *)pkt->transport_header;
+    if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) {
+        char *sdebug, *ddebug;
+        sdebug = strdup(inet_ntoa(pkt->ip->ip_src));
+        ddebug = strdup(inet_ntoa(pkt->ip->ip_dst));
+        trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug,
+                    ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack),
+                    tcp_pkt->th_flags);
+        trace_colo_filter_rewriter_conn_offset(conn->offset);
+        g_free(sdebug);
+        g_free(ddebug);
+    }
+
+    if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) {
+        /*
+         * we use this flag update offset func
+         * run once in independent tcp connection
+         */
+        conn->syn_flag = 1;
+    }
+
+    if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) {
+        if (conn->syn_flag) {
+            /*
+             * offset = secondary_seq - primary seq
+             * ack packet sent by guest from primary node,
+             * so we use th_ack - 1 get primary_seq
+             */
+            conn->offset -= (ntohl(tcp_pkt->th_ack) - 1);
+            conn->syn_flag = 0;
+        }
+        /* handle packets to the secondary from the primary */
+        tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset);
+
+        net_checksum_calculate((uint8_t *)pkt->data, pkt->size);
+    }
+
+    return 0;
+}
+
+/* handle tcp packet from secondary guest */
+static int handle_secondary_tcp_pkt(NetFilterState *nf,
+                                    Connection *conn,
+                                    Packet *pkt)
+{
+    struct tcphdr *tcp_pkt;
+
+    tcp_pkt = (struct tcphdr *)pkt->transport_header;
+
+    if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) {
+        char *sdebug, *ddebug;
+        sdebug = strdup(inet_ntoa(pkt->ip->ip_src));
+        ddebug = strdup(inet_ntoa(pkt->ip->ip_dst));
+        trace_colo_filter_rewriter_pkt_info(__func__, sdebug, ddebug,
+                    ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack),
+                    tcp_pkt->th_flags);
+        trace_colo_filter_rewriter_conn_offset(conn->offset);
+        g_free(sdebug);
+        g_free(ddebug);
+    }
+
+    if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == (TH_ACK | TH_SYN))) {
+        /*
+         * save offset = secondary_seq and then
+         * in handle_primary_tcp_pkt make offset
+         * = secondary_seq - primary_seq
+         */
+        conn->offset = ntohl(tcp_pkt->th_seq);
+    }
+
+    if ((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK) {
+        /* handle packets to the primary from the secondary*/
+        tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset);
+
+        net_checksum_calculate((uint8_t *)pkt->data, pkt->size);
+    }
+
+    return 0;
+}
+
 static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
                                          NetClientState *sender,
                                          unsigned flags,
@@ -97,10 +185,30 @@ static ssize_t colo_rewriter_receive_iov(NetFilterState *nf,
 
         if (sender == nf->netdev) {
             /* NET_FILTER_DIRECTION_TX */
-            /* handle_primary_tcp_pkt */
+            if (!handle_primary_tcp_pkt(nf, conn, pkt)) {
+                qemu_net_queue_send(s->incoming_queue, sender, 0,
+                (const uint8_t *)pkt->data, pkt->size, NULL);
+                packet_destroy(pkt, NULL);
+                pkt = NULL;
+                /*
+                 * We block the packet here,after rewrite pkt
+                 * and will send it
+                 */
+                return 1;
+            }
         } else {
             /* NET_FILTER_DIRECTION_RX */
-            /* handle_secondary_tcp_pkt */
+            if (!handle_secondary_tcp_pkt(nf, conn, pkt)) {
+                qemu_net_queue_send(s->incoming_queue, sender, 0,
+                (const uint8_t *)pkt->data, pkt->size, NULL);
+                packet_destroy(pkt, NULL);
+                pkt = NULL;
+                /*
+                 * We block the packet here,after rewrite pkt
+                 * and will send it
+                 */
+                return 1;
+            }
         }
     }