MdePkg/UefiDevicePathLib: Add DevPathFromTextDns and DevPathToTextDns libraries

V3:
* Fix the bug in DevPathFromTextDns()

V2:
* Add no IP instance case check.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>

MdePkg/Library/UefiDevicePathLib/DevicePathFromText.c

@@ -2724,6 +2724,98 @@ DevPathFromTextBluetoothLE (
   return (EFI_DEVICE_PATH_PROTOCOL *) BluetoothLeDp;
 }
 
+/**
+  Converts a text device path node to DNS device path structure.
+
+  @param TextDeviceNode  The input Text device path node.
+
+  @return A pointer to the newly-created DNS device path structure.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+DevPathFromTextDns (
+  IN CHAR16 *TextDeviceNode
+  )
+{
+  CHAR16            *DeviceNodeStr;
+  CHAR16            *DeviceNodeStrPtr;
+  UINT32            DnsServerIpCount;
+  UINT16            DnsDeviceNodeLength;
+  DNS_DEVICE_PATH   *DnsDeviceNode;
+  UINT32            DnsServerIpIndex;
+  CHAR16            *DnsServerIp;
+
+
+  //
+  // Count the DNS server address number.
+  //
+  DeviceNodeStr = UefiDevicePathLibStrDuplicate (TextDeviceNode);
+  if (DeviceNodeStr == NULL) {
+    return NULL;
+  }
+
+  DeviceNodeStrPtr = DeviceNodeStr;
+  
+  DnsServerIpCount = 0;
+  while (DeviceNodeStrPtr != NULL && *DeviceNodeStrPtr != L'\0') {
+    GetNextParamStr (&DeviceNodeStrPtr);
+    DnsServerIpCount ++; 
+  }
+
+  FreePool (DeviceNodeStr);
+  DeviceNodeStr = NULL;
+
+  //
+  // One or more instances of the DNS server address in EFI_IP_ADDRESS, 
+  // otherwise, NULL will be returned.
+  //
+  if (DnsServerIpCount == 0) {
+    return NULL;
+  }
+
+  //
+  // Create the DNS DeviceNode.
+  //
+  DnsDeviceNodeLength = (UINT16) (sizeof (EFI_DEVICE_PATH_PROTOCOL) + sizeof (UINT8) + DnsServerIpCount * sizeof (EFI_IP_ADDRESS));
+  DnsDeviceNode       = (DNS_DEVICE_PATH *) CreateDeviceNode (
+                                              MESSAGING_DEVICE_PATH,
+                                              MSG_DNS_DP,
+                                              DnsDeviceNodeLength
+                                              );
+  if (DnsDeviceNode == NULL) {
+    return NULL;
+  }
+
+  //
+  // Confirm the DNS server address is IPv4 or IPv6 type.
+  //
+  DeviceNodeStrPtr = TextDeviceNode;
+  while (!IS_NULL (*DeviceNodeStrPtr)) {
+    if (*DeviceNodeStrPtr == L'.') {
+      DnsDeviceNode->IsIPv6 = 0x00;
+      break;
+    }
+
+    if (*DeviceNodeStrPtr == L':') {
+      DnsDeviceNode->IsIPv6 = 0x01;
+      break;
+    }
+
+    DeviceNodeStrPtr++;
+  }
+
+  for (DnsServerIpIndex = 0; DnsServerIpIndex < DnsServerIpCount; DnsServerIpIndex++) {
+    DnsServerIp = GetNextParamStr (&TextDeviceNode);
+    if (DnsDeviceNode->IsIPv6 == 0x00) {
+      StrToIpv4Address (DnsServerIp,  NULL, &(DnsDeviceNode->DnsServerIp[DnsServerIpIndex].v4), NULL);
+    } else {
+      StrToIpv6Address (DnsServerIp, NULL, &(DnsDeviceNode->DnsServerIp[DnsServerIpIndex].v6), NULL);
+    }
+  }
+  
+  return (EFI_DEVICE_PATH_PROTOCOL *) DnsDeviceNode;
+}
+
 /**
   Converts a text device path node to URI device path structure.
 
@@ -3397,6 +3489,7 @@ GLOBAL_REMOVE_IF_UNREFERENCED DEVICE_PATH_FROM_TEXT_TABLE mUefiDevicePathLibDevP
   {L"Unit",                    DevPathFromTextUnit                    },
   {L"iSCSI",                   DevPathFromTextiSCSI                   },
   {L"Vlan",                    DevPathFromTextVlan                    },
+  {L"Dns",                     DevPathFromTextDns                     },
   {L"Uri",                     DevPathFromTextUri                     },
   {L"Bluetooth",               DevPathFromTextBluetooth               },
   {L"Wi-Fi",                   DevPathFromTextWiFi                    },

MdePkg/Library/UefiDevicePathLib/DevicePathToText.c

@@ -1696,6 +1696,51 @@ DevPathToTextBluetoothLE (
     );
 }
 
+/**
+  Converts a DNS device path structure to its string representative.
+
+  @param Str             The string representative of input device.
+  @param DevPath         The input device path structure.
+  @param DisplayOnly     If DisplayOnly is TRUE, then the shorter text representation
+                         of the display node is used, where applicable. If DisplayOnly
+                         is FALSE, then the longer text representation of the display node
+                         is used.
+  @param AllowShortcuts  If AllowShortcuts is TRUE, then the shortcut forms of text
+                         representation for a device node can be used, where applicable.
+
+**/
+VOID
+DevPathToTextDns (
+  IN OUT POOL_PRINT  *Str,
+  IN VOID            *DevPath,
+  IN BOOLEAN         DisplayOnly,
+  IN BOOLEAN         AllowShortcuts
+  )
+{
+  DNS_DEVICE_PATH  *DnsDevPath;
+  UINT32           DnsServerIpCount;
+  UINT32           DnsServerIpIndex;
+
+  DnsDevPath     = DevPath;
+  DnsServerIpCount = (UINT32) (DevicePathNodeLength(DnsDevPath) - sizeof (EFI_DEVICE_PATH_PROTOCOL) - sizeof (DnsDevPath->IsIPv6)) / sizeof (EFI_IP_ADDRESS);
+
+  UefiDevicePathLibCatPrint (Str, L"Dns(");
+  
+  for (DnsServerIpIndex = 0; DnsServerIpIndex < DnsServerIpCount; DnsServerIpIndex++) {
+    if (DnsDevPath->IsIPv6 == 0x00) {
+      CatIPv4Address (Str, &(DnsDevPath->DnsServerIp[DnsServerIpIndex].v4));
+    } else {
+      CatIPv6Address (Str, &(DnsDevPath->DnsServerIp[DnsServerIpIndex].v6));
+    }
+
+    if (DnsServerIpIndex < DnsServerIpCount - 1) {
+      UefiDevicePathLibCatPrint (Str, L",");
+    }
+  }
+
+  UefiDevicePathLibCatPrint (Str, L")");
+}
+
 /**
   Converts a URI device path structure to its string representative.
 
@@ -2225,6 +2270,7 @@ GLOBAL_REMOVE_IF_UNREFERENCED const DEVICE_PATH_TO_TEXT_TABLE mUefiDevicePathLib
   {MESSAGING_DEVICE_PATH, MSG_VENDOR_DP,                    DevPathToTextVendor         },
   {MESSAGING_DEVICE_PATH, MSG_ISCSI_DP,                     DevPathToTextiSCSI          },
   {MESSAGING_DEVICE_PATH, MSG_VLAN_DP,                      DevPathToTextVlan           },
+  {MESSAGING_DEVICE_PATH, MSG_DNS_DP,                       DevPathToTextDns            },
   {MESSAGING_DEVICE_PATH, MSG_URI_DP,                       DevPathToTextUri            },
   {MESSAGING_DEVICE_PATH, MSG_BLUETOOTH_DP,                 DevPathToTextBluetooth      },
   {MESSAGING_DEVICE_PATH, MSG_WIFI_DP,                      DevPathToTextWiFi           },