From 38964ddc78c230ce3f4a1f9d44feeea55bd12635 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sat, 28 Dec 2013 13:30:17 -0600 Subject: [PATCH] win32_create_file(): Handle access problems --- src/win32_apply.c | 60 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 51 insertions(+), 9 deletions(-) diff --git a/src/win32_apply.c b/src/win32_apply.c index c8f65ef0..312bd876 100644 --- a/src/win32_apply.c +++ b/src/win32_apply.c @@ -81,21 +81,63 @@ win32_start_extract(const wchar_t *path, struct apply_ctx *ctx) return 0; } +/* Create a normal file, overwriting one already present. */ static int win32_create_file(const wchar_t *path, struct apply_ctx *ctx, u64 *cookie_ret) { HANDLE h; - - h = CreateFile(path, 0, 0, NULL, CREATE_ALWAYS, - FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS, NULL); - if (h == INVALID_HANDLE_VALUE) - goto error; + unsigned retry_count = 0; + DWORD dwFlagsAndAttributes = FILE_FLAG_BACKUP_SEMANTICS; + +retry: + /* WRITE_OWNER and WRITE_DAC privileges are required for some reason, + * even through we're creating a new file. */ + h = CreateFile(path, WRITE_OWNER | WRITE_DAC, 0, NULL, + CREATE_ALWAYS, dwFlagsAndAttributes, NULL); + if (h == INVALID_HANDLE_VALUE) { + /* File couldn't be created. */ + DWORD err = GetLastError(); + if (err == ERROR_ACCESS_DENIED && retry_count == 0) { + + /* Access denied error for the first time. Try + * adjusting file attributes. */ + + /* Get attributes of the existing file. */ + DWORD attribs = GetFileAttributes(path); + if (attribs != INVALID_FILE_ATTRIBUTES && + (attribs & (FILE_ATTRIBUTE_HIDDEN | + FILE_ATTRIBUTE_SYSTEM | + FILE_ATTRIBUTE_READONLY))) + { + /* If the existing file has + * FILE_ATTRIBUTE_HIDDEN and/or + * FILE_ATTRIBUTE_SYSTEM, they must be set in + * the call to CreateFile(). This is true even + * when FILE_ATTRIBUTE_NORMAL was not specified, + * contrary to the MS "documentation". */ + dwFlagsAndAttributes |= (attribs & + (FILE_ATTRIBUTE_HIDDEN | + FILE_ATTRIBUTE_SYSTEM)); + /* If the existing file has + * FILE_ATTRIBUTE_READONLY, it must be cleared + * before attempting to create a new file over + * it. This is true even when the process has + * the SE_RESTORE_NAME privilege and requested + * the FILE_FLAG_BACKUP_SEMANTICS flag to + * CreateFile(). */ + if (attribs & FILE_ATTRIBUTE_READONLY) { + SetFileAttributes(path, + attribs & ~FILE_ATTRIBUTE_READONLY); + } + retry_count++; + goto retry; + } + } + set_errno_from_win32_error(err); + return WIMLIB_ERR_OPEN; + } CloseHandle(h); return 0; - -error: - set_errno_from_GetLastError(); - return WIMLIB_ERR_OPEN; } static int -- 2.43.0