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Diffstat (limited to 'lib/libefivar/uefi-dputil.c')
| -rw-r--r-- | lib/libefivar/uefi-dputil.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/lib/libefivar/uefi-dputil.c b/lib/libefivar/uefi-dputil.c new file mode 100644 index 000000000000..6e8f3aeca2ce --- /dev/null +++ b/lib/libefivar/uefi-dputil.c @@ -0,0 +1,632 @@ +/*- + * Copyright (c) 2017 Netflix, Inc. + * + * 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. + * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <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 should 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 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; +} |