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+/*-
+ * Copyright (c) 2017 Netflix, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer
+ * in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Routines to format EFI_DEVICE_PATHs from the UEFI standard. Much of
+ * this file is taken from EDK2 and rototilled.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <efivar.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/endian.h>
+
+#include "efi-osdep.h"
+
+#include "uefi-dplib.h"
+
+/* XXX maybe I sould include the entire DevicePathUtiltiies.c and ifdef out what we don't use */
+
+/*
+ * Taken from MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c
+ * hash a11928f3310518ab1c6fd34e8d0fdbb72de9602c 2017-Mar-01
+ */
+
+/** @file
+ Device Path services. The thing to remember is device paths are built out of
+ nodes. The device path is terminated by an end node that is length
+ sizeof(EFI_DEVICE_PATH_PROTOCOL). That would be why there is sizeof(EFI_DEVICE_PATH_PROTOCOL)
+ all over this file.
+
+ The only place where multi-instance device paths are supported is in
+ environment varibles. Multi-instance device paths should never be placed
+ on a Handle.
+
+ Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+//
+// Template for an end-of-device path node.
+//
+static CONST EFI_DEVICE_PATH_PROTOCOL mUefiDevicePathLibEndDevicePath = {
+ END_DEVICE_PATH_TYPE,
+ END_ENTIRE_DEVICE_PATH_SUBTYPE,
+ {
+ END_DEVICE_PATH_LENGTH,
+ 0
+ }
+};
+
+
+/**
+ Returns the size of a device path in bytes.
+
+ This function returns the size, in bytes, of the device path data structure
+ specified by DevicePath including the end of device path node.
+ If DevicePath is NULL or invalid, then 0 is returned.
+
+ @param DevicePath A pointer to a device path data structure.
+
+ @retval 0 If DevicePath is NULL or invalid.
+ @retval Others The size of a device path in bytes.
+
+**/
+UINTN
+EFIAPI
+GetDevicePathSize (
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
+ )
+{
+ CONST EFI_DEVICE_PATH_PROTOCOL *Start;
+
+ if (DevicePath == NULL) {
+ return 0;
+ }
+
+ if (!IsDevicePathValid (DevicePath, 0)) {
+ return 0;
+ }
+
+ //
+ // Search for the end of the device path structure
+ //
+ Start = DevicePath;
+ while (!IsDevicePathEnd (DevicePath)) {
+ DevicePath = NextDevicePathNode (DevicePath);
+ }
+
+ //
+ // Compute the size and add back in the size of the end device path structure
+ //
+ return ((UINTN) DevicePath - (UINTN) Start) + DevicePathNodeLength (DevicePath);
+}
+
+/**
+ Determine whether a given device path is valid.
+ If DevicePath is NULL, then ASSERT().
+
+ @param DevicePath A pointer to a device path data structure.
+ @param MaxSize The maximum size of the device path data structure.
+
+ @retval TRUE DevicePath is valid.
+ @retval FALSE The length of any node node in the DevicePath is less
+ than sizeof (EFI_DEVICE_PATH_PROTOCOL).
+ @retval FALSE If MaxSize is not zero, the size of the DevicePath
+ exceeds MaxSize.
+ @retval FALSE If PcdMaximumDevicePathNodeCount is not zero, the node
+ count of the DevicePath exceeds PcdMaximumDevicePathNodeCount.
+**/
+BOOLEAN
+EFIAPI
+IsDevicePathValid (
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath,
+ IN UINTN MaxSize
+ )
+{
+ UINTN Count;
+ UINTN Size;
+ UINTN NodeLength;
+
+ ASSERT (DevicePath != NULL);
+
+ if (MaxSize == 0) {
+ MaxSize = MAX_UINTN;
+ }
+
+ //
+ // Validate the input size big enough to touch the first node.
+ //
+ if (MaxSize < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
+ return FALSE;
+ }
+
+ for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
+ NodeLength = DevicePathNodeLength (DevicePath);
+ if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
+ return FALSE;
+ }
+
+ if (NodeLength > MAX_UINTN - Size) {
+ return FALSE;
+ }
+ Size += NodeLength;
+
+ //
+ // Validate next node before touch it.
+ //
+ if (Size > MaxSize - END_DEVICE_PATH_LENGTH ) {
+ return FALSE;
+ }
+
+ if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {
+ Count++;
+ if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) {
+ return FALSE;
+ }
+ }
+ }
+
+ //
+ // Only return TRUE when the End Device Path node is valid.
+ //
+ return (BOOLEAN) (DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH);
+}
+
+/**
+ Returns the Type field of a device path node.
+
+ Returns the Type field of the device path node specified by Node.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @return The Type field of the device path node specified by Node.
+
+**/
+UINT8
+EFIAPI
+DevicePathType (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return ((const EFI_DEVICE_PATH_PROTOCOL *)(Node))->Type;
+}
+
+
+/**
+ Returns the SubType field of a device path node.
+
+ Returns the SubType field of the device path node specified by Node.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @return The SubType field of the device path node specified by Node.
+
+**/
+UINT8
+EFIAPI
+DevicePathSubType (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return ((const EFI_DEVICE_PATH_PROTOCOL *)(Node))->SubType;
+}
+
+/**
+ Returns the 16-bit Length field of a device path node.
+
+ Returns the 16-bit Length field of the device path node specified by Node.
+ Node is not required to be aligned on a 16-bit boundary, so it is recommended
+ that a function such as ReadUnaligned16() be used to extract the contents of
+ the Length field.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @return The 16-bit Length field of the device path node specified by Node.
+
+**/
+UINTN
+EFIAPI
+DevicePathNodeLength (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return ((const EFI_DEVICE_PATH_PROTOCOL *)Node)->Length[0] |
+ (((const EFI_DEVICE_PATH_PROTOCOL *)Node)->Length[1] << 8);
+}
+
+/**
+ Returns a pointer to the next node in a device path.
+
+ Returns a pointer to the device path node that follows the device path node
+ specified by Node.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @return a pointer to the device path node that follows the device path node
+ specified by Node.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+EFIAPI
+NextDevicePathNode (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return ((EFI_DEVICE_PATH_PROTOCOL *)(__DECONST(UINT8 *, Node) + DevicePathNodeLength(Node)));
+}
+
+/**
+ Determines if a device path node is an end node of a device path.
+ This includes nodes that are the end of a device path instance and nodes that
+ are the end of an entire device path.
+
+ Determines if the device path node specified by Node is an end node of a device path.
+ This includes nodes that are the end of a device path instance and nodes that are the
+ end of an entire device path. If Node represents an end node of a device path,
+ then TRUE is returned. Otherwise, FALSE is returned.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @retval TRUE The device path node specified by Node is an end node of a
+ device path.
+ @retval FALSE The device path node specified by Node is not an end node of
+ a device path.
+
+**/
+BOOLEAN
+EFIAPI
+IsDevicePathEndType (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return (BOOLEAN) (DevicePathType (Node) == END_DEVICE_PATH_TYPE);
+}
+
+/**
+ Determines if a device path node is an end node of an entire device path.
+
+ Determines if a device path node specified by Node is an end node of an entire
+ device path. If Node represents the end of an entire device path, then TRUE is
+ returned. Otherwise, FALSE is returned.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+ @retval TRUE The device path node specified by Node is the end of an entire
+ device path.
+ @retval FALSE The device path node specified by Node is not the end of an
+ entire device path.
+
+**/
+BOOLEAN
+EFIAPI
+IsDevicePathEnd (
+ IN CONST VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ return (BOOLEAN) (IsDevicePathEndType (Node) && DevicePathSubType(Node) == END_ENTIRE_DEVICE_PATH_SUBTYPE);
+}
+
+/**
+ Fills in all the fields of a device path node that is the end of an entire device path.
+
+ Fills in all the fields of a device path node specified by Node so Node represents
+ the end of an entire device path. The Type field of Node is set to
+ END_DEVICE_PATH_TYPE, the SubType field of Node is set to
+ END_ENTIRE_DEVICE_PATH_SUBTYPE, and the Length field of Node is set to
+ END_DEVICE_PATH_LENGTH. Node is not required to be aligned on a 16-bit boundary,
+ so it is recommended that a function such as WriteUnaligned16() be used to set
+ the contents of the Length field.
+
+ If Node is NULL, then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+
+**/
+VOID
+EFIAPI
+SetDevicePathEndNode (
+ OUT VOID *Node
+ )
+{
+ ASSERT (Node != NULL);
+ memcpy (Node, &mUefiDevicePathLibEndDevicePath, sizeof (mUefiDevicePathLibEndDevicePath));
+}
+
+/**
+ Sets the length, in bytes, of a device path node.
+
+ Sets the length of the device path node specified by Node to the value specified
+ by NodeLength. NodeLength is returned. Node is not required to be aligned on
+ a 16-bit boundary, so it is recommended that a function such as WriteUnaligned16()
+ be used to set the contents of the Length field.
+
+ If Node is NULL, then ASSERT().
+ If NodeLength >= SIZE_64KB, then ASSERT().
+ If NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL), then ASSERT().
+
+ @param Node A pointer to a device path node data structure.
+ @param Length The length, in bytes, of the device path node.
+
+ @return Length
+
+**/
+UINT16
+EFIAPI
+SetDevicePathNodeLength (
+ IN OUT VOID *Node,
+ IN UINTN Length
+ )
+{
+ ASSERT (Node != NULL);
+ ASSERT ((Length >= sizeof (EFI_DEVICE_PATH_PROTOCOL)) && (Length < SIZE_64KB));
+// return WriteUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));
+ le16enc(&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0], (UINT16)(Length));
+ return Length;
+}
+
+/**
+ Creates a device node.
+
+ This function creates a new device node in a newly allocated buffer of size
+ NodeLength and initializes the device path node header with NodeType and NodeSubType.
+ The new device path node is returned.
+ If NodeLength is smaller than a device path header, then NULL is returned.
+ If there is not enough memory to allocate space for the new device path, then
+ NULL is returned.
+ The memory is allocated from EFI boot services memory. It is the responsibility
+ of the caller to free the memory allocated.
+
+ @param NodeType The device node type for the new device node.
+ @param NodeSubType The device node sub-type for the new device node.
+ @param NodeLength The length of the new device node.
+
+ @return The new device path.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+EFIAPI
+CreateDeviceNode (
+ IN UINT8 NodeType,
+ IN UINT8 NodeSubType,
+ IN UINT16 NodeLength
+ )
+{
+ EFI_DEVICE_PATH_PROTOCOL *DevicePath;
+
+ if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
+ //
+ // NodeLength is less than the size of the header.
+ //
+ return NULL;
+ }
+
+ DevicePath = AllocateZeroPool (NodeLength);
+ if (DevicePath != NULL) {
+ DevicePath->Type = NodeType;
+ DevicePath->SubType = NodeSubType;
+ SetDevicePathNodeLength (DevicePath, NodeLength);
+ }
+
+ return DevicePath;
+}
+
+/**
+ Creates a new copy of an existing device path.
+
+ This function allocates space for a new copy of the device path specified by DevicePath.
+ If DevicePath is NULL, then NULL is returned. If the memory is successfully
+ allocated, then the contents of DevicePath are copied to the newly allocated
+ buffer, and a pointer to that buffer is returned. Otherwise, NULL is returned.
+ The memory for the new device path is allocated from EFI boot services memory.
+ It is the responsibility of the caller to free the memory allocated.
+
+ @param DevicePath A pointer to a device path data structure.
+
+ @retval NULL DevicePath is NULL or invalid.
+ @retval Others A pointer to the duplicated device path.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+EFIAPI
+DuplicateDevicePath (
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath
+ )
+{
+ UINTN Size;
+
+ //
+ // Compute the size
+ //
+ Size = GetDevicePathSize (DevicePath);
+ if (Size == 0) {
+ return NULL;
+ }
+
+ //
+ // Allocate space for duplicate device path
+ //
+
+ return AllocateCopyPool (Size, DevicePath);
+}
+
+/**
+ Creates a new device path by appending a second device path to a first device path.
+
+ This function creates a new device path by appending a copy of SecondDevicePath
+ to a copy of FirstDevicePath in a newly allocated buffer. Only the end-of-device-path
+ device node from SecondDevicePath is retained. The newly created device path is
+ returned. If FirstDevicePath is NULL, then it is ignored, and a duplicate of
+ SecondDevicePath is returned. If SecondDevicePath is NULL, then it is ignored,
+ and a duplicate of FirstDevicePath is returned. If both FirstDevicePath and
+ SecondDevicePath are NULL, then a copy of an end-of-device-path is returned.
+
+ If there is not enough memory for the newly allocated buffer, then NULL is returned.
+ The memory for the new device path is allocated from EFI boot services memory.
+ It is the responsibility of the caller to free the memory allocated.
+
+ @param FirstDevicePath A pointer to a device path data structure.
+ @param SecondDevicePath A pointer to a device path data structure.
+
+ @retval NULL If there is not enough memory for the newly allocated buffer.
+ @retval NULL If FirstDevicePath or SecondDevicePath is invalid.
+ @retval Others A pointer to the new device path if success.
+ Or a copy an end-of-device-path if both FirstDevicePath and SecondDevicePath are NULL.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+EFIAPI
+AppendDevicePath (
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *FirstDevicePath, OPTIONAL
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *SecondDevicePath OPTIONAL
+ )
+{
+ UINTN Size;
+ UINTN Size1;
+ UINTN Size2;
+ EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
+ EFI_DEVICE_PATH_PROTOCOL *DevicePath2;
+
+ //
+ // If there's only 1 path, just duplicate it.
+ //
+ if (FirstDevicePath == NULL) {
+ return DuplicateDevicePath ((SecondDevicePath != NULL) ? SecondDevicePath : &mUefiDevicePathLibEndDevicePath);
+ }
+
+ if (SecondDevicePath == NULL) {
+ return DuplicateDevicePath (FirstDevicePath);
+ }
+
+ if (!IsDevicePathValid (FirstDevicePath, 0) || !IsDevicePathValid (SecondDevicePath, 0)) {
+ return NULL;
+ }
+
+ //
+ // Allocate space for the combined device path. It only has one end node of
+ // length EFI_DEVICE_PATH_PROTOCOL.
+ //
+ Size1 = GetDevicePathSize (FirstDevicePath);
+ Size2 = GetDevicePathSize (SecondDevicePath);
+ Size = Size1 + Size2 - END_DEVICE_PATH_LENGTH;
+
+ NewDevicePath = AllocatePool (Size);
+
+ if (NewDevicePath != NULL) {
+ NewDevicePath = CopyMem (NewDevicePath, FirstDevicePath, Size1);
+ //
+ // Over write FirstDevicePath EndNode and do the copy
+ //
+ DevicePath2 = (EFI_DEVICE_PATH_PROTOCOL *) ((CHAR8 *) NewDevicePath +
+ (Size1 - END_DEVICE_PATH_LENGTH));
+ CopyMem (DevicePath2, SecondDevicePath, Size2);
+ }
+
+ return NewDevicePath;
+}
+
+/**
+ Creates a new path by appending the device node to the device path.
+
+ This function creates a new device path by appending a copy of the device node
+ specified by DevicePathNode to a copy of the device path specified by DevicePath
+ in an allocated buffer. The end-of-device-path device node is moved after the
+ end of the appended device node.
+ If DevicePathNode is NULL then a copy of DevicePath is returned.
+ If DevicePath is NULL then a copy of DevicePathNode, followed by an end-of-device
+ path device node is returned.
+ If both DevicePathNode and DevicePath are NULL then a copy of an end-of-device-path
+ device node is returned.
+ If there is not enough memory to allocate space for the new device path, then
+ NULL is returned.
+ The memory is allocated from EFI boot services memory. It is the responsibility
+ of the caller to free the memory allocated.
+
+ @param DevicePath A pointer to a device path data structure.
+ @param DevicePathNode A pointer to a single device path node.
+
+ @retval NULL If there is not enough memory for the new device path.
+ @retval Others A pointer to the new device path if success.
+ A copy of DevicePathNode followed by an end-of-device-path node
+ if both FirstDevicePath and SecondDevicePath are NULL.
+ A copy of an end-of-device-path node if both FirstDevicePath
+ and SecondDevicePath are NULL.
+
+**/
+EFI_DEVICE_PATH_PROTOCOL *
+EFIAPI
+AppendDevicePathNode (
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePath, OPTIONAL
+ IN CONST EFI_DEVICE_PATH_PROTOCOL *DevicePathNode OPTIONAL
+ )
+{
+ EFI_DEVICE_PATH_PROTOCOL *TempDevicePath;
+ EFI_DEVICE_PATH_PROTOCOL *NextNode;
+ EFI_DEVICE_PATH_PROTOCOL *NewDevicePath;
+ UINTN NodeLength;
+
+ if (DevicePathNode == NULL) {
+ return DuplicateDevicePath ((DevicePath != NULL) ? DevicePath : &mUefiDevicePathLibEndDevicePath);
+ }
+ //
+ // Build a Node that has a terminator on it
+ //
+ NodeLength = DevicePathNodeLength (DevicePathNode);
+
+ TempDevicePath = AllocatePool (NodeLength + END_DEVICE_PATH_LENGTH);
+ if (TempDevicePath == NULL) {
+ return NULL;
+ }
+ TempDevicePath = CopyMem (TempDevicePath, DevicePathNode, NodeLength);
+ //
+ // Add and end device path node to convert Node to device path
+ //
+ NextNode = NextDevicePathNode (TempDevicePath);
+ SetDevicePathEndNode (NextNode);
+ //
+ // Append device paths
+ //
+ NewDevicePath = AppendDevicePath (DevicePath, TempDevicePath);
+
+ FreePool (TempDevicePath);
+
+ return NewDevicePath;
+}