Use innerpacket's destip as source ip while doing Tx Port mirroring

When Transmit port mirroring is enabled, packet received on Fabric
interface is right now mirrored using the source IP of the inner packet.
This results in RPF failure on Analyzer VM's compute node because the
compute node which is doing the port mirroring is using other compute
node's VM IP.

As a fix, if mirroring is Tax mirroring, rather using inner packets
source ip, dest ip is used, so that Analyzer VM's RPF will not have any
issues

Change-Id: I5beaa0dd0cc3c886a1e77f244c8003595ed348e2
closes-bug: #1550312

dp-core/vr_mirror.c

@@ -368,7 +368,7 @@ int
 vr_mirror(struct vrouter *router, uint8_t mirror_id,
           struct vr_packet *pkt, struct vr_forwarding_md *fmd)
 {
-    bool reset;
+    bool reset = true;
     unsigned int captured_len, clone_len = VR_MIRROR_PKT_HEAD_SPACE,
                  mirror_md_len = 0;
     unsigned char default_mme[2] = {0xff, 0x0};
@@ -417,35 +417,37 @@ vr_mirror(struct vrouter *router, uint8_t mirror_id,
      * header. If not get the processed headers by resetting the packet
      * and mirror it
      */
-    reset = true;
-    if (pkt->vp_if && pkt->vp_if->vif_type == VIF_TYPE_PHYSICAL) {
+    if (pkt->vp_if && (pkt->vp_if->vif_type == VIF_TYPE_PHYSICAL)) {
         pkt_nh = pkt->vp_nh;
         if (pkt_nh && (pkt_nh->nh_flags & NH_FLAG_VALID) &&
                     (pkt_nh->nh_type == NH_ENCAP)) {
 
             reset = false;
-            if (pkt_nh->nh_family == AF_INET)
-                clone_len += pkt_nh->nh_encap_len;
-
-            if (vr_pcow(pkt, clone_len))
-                goto fail;
-
-
-            if (pkt_nh->nh_family == AF_INET) {
-                if (!pkt_nh->nh_dev->vif_set_rewrite(pkt_nh->nh_dev, pkt, fmd,
-                    pkt_nh->nh_data, pkt_nh->nh_encap_len))
-                goto fail;
+            if (fmd->fmd_flow_index >= 0) {
+                if (pkt_nh->nh_family == AF_INET)
+                    clone_len += pkt_nh->nh_encap_len;
+
+                if (vr_pcow(pkt, clone_len))
+                    goto fail;
+                clone_len = 0;
+
+                if (pkt_nh->nh_family == AF_INET) {
+                    if (!pkt_nh->nh_dev->vif_set_rewrite(pkt_nh->nh_dev, pkt, fmd,
+                                    pkt_nh->nh_data, pkt_nh->nh_encap_len))
+                        goto fail;
+                }
             }
         }
     }
 
-    if (reset) {
+    if (reset)
         vr_preset(pkt);
+
+    if (clone_len) {
         if (vr_pcow(pkt, clone_len))
             goto fail;
     }
 
-
     pkt->vp_flags |= VP_FLAG_FROM_DP;
     /* Set the GSO and partial checksum flag */
     pkt->vp_flags |= (VP_FLAG_FLOW_SET | VP_FLAG_GSO | VP_FLAG_CSUM_PARTIAL);

dp-core/vr_nexthop.c

@@ -407,6 +407,7 @@ nh_udp_tunnel_helper(struct vr_packet *pkt, unsigned short sport,
 static bool
 nh_udp_tunnel6_helper(struct vr_packet *pkt, struct vr_nexthop *nh)
 {
+    unsigned int v4_ip;
     uint8_t *sip = NULL;
     uint8_t sip6[VR_IP6_ADDRESS_LEN];
 
@@ -417,10 +418,19 @@ nh_udp_tunnel6_helper(struct vr_packet *pkt, struct vr_nexthop *nh)
     if (nh->nh_flags & NH_FLAG_TUNNEL_SIP_COPY) {
         if (pkt->vp_type == VP_TYPE_IP6) {
             ip6 = (struct vr_ip6 *)pkt_network_header(pkt);
+
+            if (pkt->vp_if->vif_type == VIF_TYPE_PHYSICAL)
+                sip = ip6->ip6_dst;
             sip = ip6->ip6_src;
+
         } else if (pkt->vp_type == VP_TYPE_IP) {
             ip = (struct vr_ip *)pkt_network_header(pkt);
-            vr_inet6_generate_ip6(sip6, ip->ip_saddr);
+
+            v4_ip = ip->ip_saddr;
+            if (pkt->vp_if->vif_type == VIF_TYPE_PHYSICAL)
+                v4_ip = ip->ip_daddr;
+
+            vr_inet6_generate_ip6(sip6, v4_ip);
             sip = sip6;
         }
     }
@@ -1302,6 +1312,14 @@ nh_generate_sip(struct vr_nexthop *nh, struct vr_packet *pkt)
 
     iph = (struct vr_ip *)pkt_network_header(pkt);
     if (pkt->vp_type == VP_TYPE_IP) {
+
+        /*
+         * If the packet is from fabric, it must be destined to a VM on
+         * this compute, so lets use dest ip
+         */
+        if (pkt->vp_if->vif_type == VIF_TYPE_PHYSICAL)
+            return iph->ip_daddr;
+
         return iph->ip_saddr;
     }