From b6ce961a42f08be13f7fc7a561be530ad58434e5 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Wed, 16 Dec 2020 22:10:59 +0100 Subject: [PATCH] OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_LOOKUP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add the VirtioFsFuseLookup() function, for sending the FUSE_LOOKUP command to the Virtio Filesystem device. Cc: Ard Biesheuvel Cc: Jordan Justen Cc: Philippe Mathieu-Daudé Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097 Signed-off-by: Laszlo Ersek Message-Id: <20201216211125.19496-23-lersek@redhat.com> Acked-by: Ard Biesheuvel --- OvmfPkg/Include/IndustryStandard/VirtioFs.h | 6 + OvmfPkg/VirtioFsDxe/FuseLookup.c | 148 ++++++++++++++++++++ OvmfPkg/VirtioFsDxe/VirtioFsDxe.h | 9 ++ OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf | 1 + 4 files changed, 164 insertions(+) create mode 100644 OvmfPkg/VirtioFsDxe/FuseLookup.c diff --git a/OvmfPkg/Include/IndustryStandard/VirtioFs.h b/OvmfPkg/Include/IndustryStandard/VirtioFs.h index 5d1d990a2d..8a07b3d2eb 100644 --- a/OvmfPkg/Include/IndustryStandard/VirtioFs.h +++ b/OvmfPkg/Include/IndustryStandard/VirtioFs.h @@ -81,6 +81,11 @@ typedef struct { // #define VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID 1 +// +// Distinguished errno values. +// +#define VIRTIO_FS_FUSE_ERRNO_ENOENT (-2) + // // File mode bitmasks. // @@ -107,6 +112,7 @@ typedef struct { // FUSE operation codes. // typedef enum { + VirtioFsFuseOpLookup = 1, VirtioFsFuseOpForget = 2, VirtioFsFuseOpMkDir = 9, VirtioFsFuseOpOpen = 14, diff --git a/OvmfPkg/VirtioFsDxe/FuseLookup.c b/OvmfPkg/VirtioFsDxe/FuseLookup.c new file mode 100644 index 0000000000..5c9a825e17 --- /dev/null +++ b/OvmfPkg/VirtioFsDxe/FuseLookup.c @@ -0,0 +1,148 @@ +/** @file + FUSE_LOOKUP wrapper for the Virtio Filesystem device. + + Copyright (C) 2020, Red Hat, Inc. + + SPDX-License-Identifier: BSD-2-Clause-Patent +**/ + +#include // AsciiStrSize() + +#include "VirtioFsDxe.h" + +/** + Send a FUSE_LOOKUP request to the Virtio Filesystem device, for resolving a + filename to an inode. + + The function returns EFI_NOT_FOUND exclusively if the Virtio Filesystem + device explicitly responds with ENOENT -- "No such file or directory". + + The function may only be called after VirtioFsFuseInitSession() returns + successfully and before VirtioFsUninit() is called. + + @param[in,out] VirtioFs The Virtio Filesystem device to send the FUSE_LOOKUP + request to. On output, the FUSE request counter + "VirtioFs->RequestId" will have been incremented. + + @param[in] DirNodeId The inode number of the directory in which Name + should be resolved to an inode. + + @param[in] Name The single-component filename to resolve in the + directory identified by DirNodeId. + + @param[out] NodeId The inode number which Name has been resolved to. + + @param[out] FuseAttr The VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE object + describing the properties of the resolved inode. + + @retval EFI_SUCCESS Filename to inode resolution successful. + + @retval EFI_NOT_FOUND The Virtio Filesystem device explicitly reported + ENOENT -- "No such file or directory". + + @return The "errno" value mapped to an EFI_STATUS code, if the + Virtio Filesystem device explicitly reported an error + different from ENOENT. If said mapping resulted in + EFI_NOT_FOUND, it is remapped to EFI_DEVICE_ERROR. + + @return Error codes propagated from VirtioFsSgListsValidate(), + VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(), + VirtioFsFuseCheckResponse(). EFI_NOT_FOUND is remapped + to EFI_DEVICE_ERROR. +**/ +EFI_STATUS +VirtioFsFuseLookup ( + IN OUT VIRTIO_FS *VirtioFs, + IN UINT64 DirNodeId, + IN CHAR8 *Name, + OUT UINT64 *NodeId, + OUT VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE *FuseAttr + ) +{ + VIRTIO_FS_FUSE_REQUEST CommonReq; + VIRTIO_FS_IO_VECTOR ReqIoVec[2]; + VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList; + VIRTIO_FS_FUSE_RESPONSE CommonResp; + VIRTIO_FS_FUSE_NODE_RESPONSE NodeResp; + VIRTIO_FS_IO_VECTOR RespIoVec[3]; + VIRTIO_FS_SCATTER_GATHER_LIST RespSgList; + EFI_STATUS Status; + + // + // Set up the scatter-gather lists. + // + ReqIoVec[0].Buffer = &CommonReq; + ReqIoVec[0].Size = sizeof CommonReq; + ReqIoVec[1].Buffer = Name; + ReqIoVec[1].Size = AsciiStrSize (Name); + ReqSgList.IoVec = ReqIoVec; + ReqSgList.NumVec = ARRAY_SIZE (ReqIoVec); + + RespIoVec[0].Buffer = &CommonResp; + RespIoVec[0].Size = sizeof CommonResp; + RespIoVec[1].Buffer = &NodeResp; + RespIoVec[1].Size = sizeof NodeResp; + RespIoVec[2].Buffer = FuseAttr; + RespIoVec[2].Size = sizeof *FuseAttr; + RespSgList.IoVec = RespIoVec; + RespSgList.NumVec = ARRAY_SIZE (RespIoVec); + + // + // Validate the scatter-gather lists; calculate the total transfer sizes. + // + Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList); + if (EFI_ERROR (Status)) { + goto Fail; + } + + // + // Populate the common request header. + // + Status = VirtioFsFuseNewRequest (VirtioFs, &CommonReq, ReqSgList.TotalSize, + VirtioFsFuseOpLookup, DirNodeId); + if (EFI_ERROR (Status)) { + goto Fail; + } + + // + // Submit the request. + // + Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList); + if (EFI_ERROR (Status)) { + goto Fail; + } + + // + // Verify the response (all response buffers are fixed size). + // + Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL); + if (EFI_ERROR (Status)) { + if (Status == EFI_DEVICE_ERROR) { + DEBUG (( + ((CommonResp.Error == VIRTIO_FS_FUSE_ERRNO_ENOENT) ? + DEBUG_VERBOSE : + DEBUG_ERROR), + "%a: Label=\"%s\" DirNodeId=%Lu Name=\"%a\" Errno=%d\n", + __FUNCTION__, + VirtioFs->Label, + DirNodeId, + Name, + CommonResp.Error + )); + if (CommonResp.Error == VIRTIO_FS_FUSE_ERRNO_ENOENT) { + return EFI_NOT_FOUND; + } + Status = VirtioFsErrnoToEfiStatus (CommonResp.Error); + } + goto Fail; + } + + // + // Output the NodeId to which Name has been resolved to. + // + *NodeId = NodeResp.NodeId; + return EFI_SUCCESS; + +Fail: + return (Status == EFI_NOT_FOUND) ? EFI_DEVICE_ERROR : Status; +} diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h index 6cc5257bab..b2e4adce09 100644 --- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h +++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h @@ -236,6 +236,15 @@ VirtioFsFuseAttrToEfiFileInfo ( // Wrapper functions for FUSE commands (primitives). // +EFI_STATUS +VirtioFsFuseLookup ( + IN OUT VIRTIO_FS *VirtioFs, + IN UINT64 DirNodeId, + IN CHAR8 *Name, + OUT UINT64 *NodeId, + OUT VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE *FuseAttr + ); + EFI_STATUS VirtioFsFuseForget ( IN OUT VIRTIO_FS *VirtioFs, diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf index 7d72721884..3552ece6b9 100644 --- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf +++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf @@ -87,6 +87,7 @@ FuseForget.c FuseFsync.c FuseInit.c + FuseLookup.c FuseMkDir.c FuseOpen.c FuseOpenDir.c