Modified libslirp backend file to cover different libslirp library versions (#929)

Authored-by: Xiaodong Li <[email protected]>

Author: ChaiTowKway

source/portable/NetworkInterface/libslirp/MBuffNetifBackendLibslirp.c

@@ -197,8 +197,12 @@ void vMBuffNetifBackendInit( MessageBufferHandle_t * pxSendMsgBuffer,
 
     #if SLIRP_CHECK_VERSION( 4U, 7U, 0U )
         xSlirpConfig.version = 4U;
-    #else
+    #elif SLIRP_CHECK_VERSION( 4U, 3U, 0U )
         xSlirpConfig.version = 3U;
+    #elif SLIRP_CHECK_VERSION( 4U, 2U, 0U )
+        xSlirpConfig.version = 2U;
+    #else
+        xSlirpConfig.version = 1U;
     #endif
 
     xSlirpConfig.restricted = false;
@@ -227,7 +231,10 @@ void vMBuffNetifBackendInit( MessageBufferHandle_t * pxSendMsgBuffer,
 
     xSlirpConfig.disable_host_loopback = false;
     xSlirpConfig.enable_emu = false;
-    xSlirpConfig.disable_dns = false;
+
+    #if SLIRP_CHECK_VERSION( 4U, 3U, 0U )
+        xSlirpConfig.disable_dns = false;
+    #endif
 
     #if SLIRP_CHECK_VERSION( 4U, 7U, 0U )
         xSlirpConfig.disable_dhcp = false;