MdeModulePkg: Update IP4 stack to support point-to-point link with 31-bit mask.

[mirror_edk2.git] / MdeModulePkg / Universal / Network / Ip4Dxe / Ip4Common.c

diff --git a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Common.c b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Common.c
index 004a8bc7034d0488d5ab5d43e7bfe8796ca1f303..b582ccf13f66836768ed6e7e57865ef6af269e3e 100644 (file)
--- a/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Common.c
+++ b/MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Common.c
@@ -1,6 +1,6 @@
 /** @file\r
 \r
-Copyright (c) 2005 - 2014, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2005 - 2017, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials\r
 are licensed and made available under the terms and conditions of the BSD License\r
 which accompanies this distribution.  The full text of the license may be found at\r
@@ -267,3 +267,46 @@ Ip4NtohHead (
 \r
   return Head;\r
 }\r
+\r
+\r
+/**\r
+  Validate that Ip/Netmask pair is OK to be used as station\r
+  address. Only continuous netmasks are supported. and check\r
+  that StationAddress is a unicast address on the newtwork.\r
+\r
+  @param[in]  Ip                 The IP address to validate.\r
+  @param[in]  Netmask            The netmaks of the IP.\r
+\r
+  @retval TRUE                   The Ip/Netmask pair is valid.\r
+  @retval FALSE                  The Ip/Netmask pair is invalid.\r
+\r
+**/\r
+BOOLEAN\r
+Ip4StationAddressValid (\r
+  IN IP4_ADDR               Ip,\r
+  IN IP4_ADDR               Netmask\r
+  )\r
+{\r
+  //\r
+  // Only support the station address with 0.0.0.0/0 to enable DHCP client.\r
+  //\r
+  if (Netmask == IP4_ALLZERO_ADDRESS) {\r
+    return (BOOLEAN) (Ip == IP4_ALLZERO_ADDRESS);\r
+  }\r
+\r
+  //\r
+  // Only support the continuous net masks\r
+  //\r
+  if (NetGetMaskLength (Netmask) == (IP4_MASK_MAX + 1)) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Station address can't be class D or class E address\r
+  //\r
+  if (NetGetIpClass (Ip) > IP4_ADDR_CLASSC) {\r
+    return FALSE;\r
+  }\r
+\r
+  return NetIp4IsUnicast (Ip, Netmask);\r
+}\r