OvmfPkg/VirtioFsDxe: add helper for determining file mode bits update

Add the VirtioFsGetFuseModeUpdate() function, for determining whether an
EFI_FILE_PROTOCOL.SetInfo() invocation requests an update to the file mode
bits.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-48-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

diff --git a/OvmfPkg/Include/IndustryStandard/VirtioFs.h b/OvmfPkg/Include/IndustryStandard/VirtioFs.h
index 15fb28f95a28f0c5ce917205b708b7e9f66c97d8..dee437ec0d3987ac486d5951548a4b3d00c458d4 100644 (file)
--- a/OvmfPkg/Include/IndustryStandard/VirtioFs.h
+++ b/OvmfPkg/Include/IndustryStandard/VirtioFs.h
@@ -95,12 +95,15 @@ typedef struct {
 #define VIRTIO_FS_FUSE_MODE_PERM_RWXU 0000700u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_RUSR 0000400u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_WUSR 0000200u\r
+#define VIRTIO_FS_FUSE_MODE_PERM_XUSR 0000100u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_RWXG 0000070u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_RGRP 0000040u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_WGRP 0000020u\r
+#define VIRTIO_FS_FUSE_MODE_PERM_XGRP 0000010u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_RWXO 0000007u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_ROTH 0000004u\r
 #define VIRTIO_FS_FUSE_MODE_PERM_WOTH 0000002u\r
+#define VIRTIO_FS_FUSE_MODE_PERM_XOTH 0000001u\r
 \r
 //\r
 // Flags for VirtioFsFuseOpSetAttr, in the VIRTIO_FS_FUSE_SETATTR_REQUEST.Valid\r

diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index c56c60640ad64ac702eade55363f331e91b5c327..443bbdc616ac039bead49dd1847b5608cff3222e 100644 (file)
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -2319,3 +2319,98 @@ VirtioFsGetFuseTimeUpdates (
 \r
   return EFI_SUCCESS;\r
 }\r
+\r
+/**\r
+  Given an EFI_FILE_INFO object received in an EFI_FILE_PROTOCOL.SetInfo()\r
+  call, determine whether updating the file mode bits of the file is necessary,\r
+  relative to an EFI_FILE_INFO object describing the current state of the file.\r
+\r
+  @param[in] Info     The EFI_FILE_INFO describing the current state of the\r
+                      file. The caller is responsible for populating Info on\r
+                      input with VirtioFsFuseAttrToEfiFileInfo(), from the\r
+                      current FUSE attributes of the file. The Info->Size and\r
+                      Info->FileName members are ignored.\r
+\r
+  @param[in] NewInfo  The EFI_FILE_INFO object received in the\r
+                      EFI_FILE_PROTOCOL.SetInfo() call.\r
+\r
+  @param[out] Update  Set to TRUE on output if the file mode bits need to be\r
+                      updated. Set to FALSE otherwise.\r
+\r
+  @param[out] Mode    If Update is set to TRUE, then Mode provides the file\r
+                      mode bits to set. Otherwise, Mode is not written to.\r
+\r
+  @retval EFI_SUCCESS        Output parameters have been set successfully.\r
+\r
+  @retval EFI_ACCESS_DENIED  NewInfo requests toggling an unknown bit in the\r
+                             Attribute bitmask.\r
+\r
+  @retval EFI_ACCESS_DENIED  NewInfo requests toggling EFI_FILE_DIRECTORY in\r
+                             the Attribute bitmask.\r
+**/\r
+EFI_STATUS\r
+VirtioFsGetFuseModeUpdate (\r
+  IN     EFI_FILE_INFO *Info,\r
+  IN     EFI_FILE_INFO *NewInfo,\r
+     OUT BOOLEAN       *Update,\r
+     OUT UINT32        *Mode\r
+     )\r
+{\r
+  UINT64  Toggle;\r
+  BOOLEAN IsDirectory;\r
+  BOOLEAN IsWriteable;\r
+  BOOLEAN WillBeWriteable;\r
+\r
+  Toggle = Info->Attribute ^ NewInfo->Attribute;\r
+  if ((Toggle & ~EFI_FILE_VALID_ATTR) != 0) {\r
+    //\r
+    // Unknown attribute requested.\r
+    //\r
+    return EFI_ACCESS_DENIED;\r
+  }\r
+  if ((Toggle & EFI_FILE_DIRECTORY) != 0) {\r
+    //\r
+    // EFI_FILE_DIRECTORY cannot be toggled.\r
+    //\r
+    return EFI_ACCESS_DENIED;\r
+  }\r
+\r
+  IsDirectory     = (BOOLEAN)((Info->Attribute    & EFI_FILE_DIRECTORY) != 0);\r
+  IsWriteable     = (BOOLEAN)((Info->Attribute    & EFI_FILE_READ_ONLY) == 0);\r
+  WillBeWriteable = (BOOLEAN)((NewInfo->Attribute & EFI_FILE_READ_ONLY) == 0);\r
+\r
+  if (IsWriteable == WillBeWriteable) {\r
+    *Update = FALSE;\r
+    return EFI_SUCCESS;\r
+  }\r
+\r
+  if (IsDirectory) {\r
+    if (WillBeWriteable) {\r
+      *Mode = (VIRTIO_FS_FUSE_MODE_PERM_RWXU |\r
+               VIRTIO_FS_FUSE_MODE_PERM_RWXG |\r
+               VIRTIO_FS_FUSE_MODE_PERM_RWXO);\r
+    } else {\r
+      *Mode = (VIRTIO_FS_FUSE_MODE_PERM_RUSR |\r
+               VIRTIO_FS_FUSE_MODE_PERM_XUSR |\r
+               VIRTIO_FS_FUSE_MODE_PERM_RGRP |\r
+               VIRTIO_FS_FUSE_MODE_PERM_XGRP |\r
+               VIRTIO_FS_FUSE_MODE_PERM_ROTH |\r
+               VIRTIO_FS_FUSE_MODE_PERM_XOTH);\r
+    }\r
+  } else {\r
+    if (WillBeWriteable) {\r
+      *Mode = (VIRTIO_FS_FUSE_MODE_PERM_RUSR |\r
+               VIRTIO_FS_FUSE_MODE_PERM_WUSR |\r
+               VIRTIO_FS_FUSE_MODE_PERM_RGRP |\r
+               VIRTIO_FS_FUSE_MODE_PERM_WGRP |\r
+               VIRTIO_FS_FUSE_MODE_PERM_ROTH |\r
+               VIRTIO_FS_FUSE_MODE_PERM_WOTH);\r
+    } else {\r
+      *Mode = (VIRTIO_FS_FUSE_MODE_PERM_RUSR |\r
+               VIRTIO_FS_FUSE_MODE_PERM_RGRP |\r
+               VIRTIO_FS_FUSE_MODE_PERM_ROTH);\r
+    }\r
+  }\r
+  *Update = TRUE;\r
+  return EFI_SUCCESS;\r
+}\r

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index 4331cabbd40e7e8c754aa6c5a70633d3deca4ca2..3c3eb1ac93385332d6fabc97b024096a6935d2fe 100644 (file)
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -300,6 +300,14 @@ VirtioFsGetFuseTimeUpdates (
      OUT UINT64        *Mtime\r
   );\r
 \r
+EFI_STATUS\r
+VirtioFsGetFuseModeUpdate (\r
+  IN     EFI_FILE_INFO *Info,\r
+  IN     EFI_FILE_INFO *NewInfo,\r
+     OUT BOOLEAN       *Update,\r
+     OUT UINT32        *Mode\r
+     );\r
+\r
 //\r
 // Wrapper functions for FUSE commands (primitives).\r
 //\r