diff options
Diffstat (limited to 'erts/emulator')
-rw-r--r-- | erts/emulator/nifs/win32/win_prim_file.c | 157 |
1 files changed, 103 insertions, 54 deletions
diff --git a/erts/emulator/nifs/win32/win_prim_file.c b/erts/emulator/nifs/win32/win_prim_file.c index f7fae3c637..602a282dd1 100644 --- a/erts/emulator/nifs/win32/win_prim_file.c +++ b/erts/emulator/nifs/win32/win_prim_file.c @@ -33,16 +33,32 @@ #define FILE_SHARE_FLAGS (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE) -#define LP_PREFIX L"\\\\?\\" -#define LP_PREFIX_SIZE (sizeof(LP_PREFIX) - sizeof(WCHAR)) +/* Long paths can either be in the file (?) or the device (.) namespace. UNC + * paths are always in the file namespace. */ +#define LP_FILE_PREFIX L"\\\\?\\" +#define LP_DEV_PREFIX L"\\\\.\\" +#define LP_UNC_PREFIX (LP_FILE_PREFIX L"UNC\\") + +#define LP_PREFIX_SIZE (sizeof(LP_FILE_PREFIX) - sizeof(WCHAR)) #define LP_PREFIX_LENGTH (LP_PREFIX_SIZE / sizeof(WCHAR)) +#define LP_UNC_PREFIX_SIZE (sizeof(LP_UNC_PREFIX) - sizeof(WCHAR)) +#define LP_UNC_PREFIX_LENGTH (LP_UNC_PREFIX_SIZE / sizeof(WCHAR)) + +#define IS_LONG_PATH(length, data) \ + ((length) >= LP_PREFIX_LENGTH && \ + (!sys_memcmp((data), LP_FILE_PREFIX, LP_PREFIX_SIZE) || \ + !sys_memcmp((data), LP_DEV_PREFIX, LP_PREFIX_SIZE))) + +#define IS_LONG_UNC_PATH(length, data) \ + ((length) >= LP_UNC_PREFIX_LENGTH && \ + !sys_memcmp((data), LP_UNC_PREFIX, LP_UNC_PREFIX_SIZE)) + #define PATH_LENGTH(path) (path->size / sizeof(WCHAR) - 1) #define ASSERT_PATH_FORMAT(path) \ do { \ - ASSERT(PATH_LENGTH(path) >= 4 && \ - !memcmp(path->data, LP_PREFIX, LP_PREFIX_SIZE)); \ + ASSERT(IS_LONG_PATH(PATH_LENGTH(path), (path)->data)); \ ASSERT(PATH_LENGTH(path) == wcslen((WCHAR*)path->data)); \ } while(0) @@ -106,7 +122,7 @@ static posix_errno_t get_full_path(ErlNifEnv *env, WCHAR *input, efile_path_t *r return ENOENT; } - maximum_length += LP_PREFIX_LENGTH; + maximum_length += MAX(LP_PREFIX_LENGTH, LP_UNC_PREFIX_LENGTH); if(!enif_alloc_binary(maximum_length * sizeof(WCHAR), result)) { return ENOMEM; @@ -115,18 +131,28 @@ static posix_errno_t get_full_path(ErlNifEnv *env, WCHAR *input, efile_path_t *r actual_length = GetFullPathNameW(input, maximum_length, (WCHAR*)result->data, NULL); if(actual_length < maximum_length) { - int has_long_path_prefix; + int is_long_path, maybe_unc_path; WCHAR *path_start; - /* Make sure we have a long-path prefix; GetFullPathNameW only adds one - * if the path is relative. */ - has_long_path_prefix = actual_length >= LP_PREFIX_LENGTH && - !sys_memcmp(result->data, LP_PREFIX, LP_PREFIX_SIZE); - - if(!has_long_path_prefix) { + /* The APIs we use have varying path length limits and sometimes + * behave differently when given a long-path prefix, so it's simplest + * to always use long paths. */ + + is_long_path = IS_LONG_PATH(actual_length, result->data); + maybe_unc_path = !sys_memcmp(result->data, L"\\\\", sizeof(WCHAR) * 2); + + if(maybe_unc_path && !is_long_path) { + /* \\localhost\c$\gurka -> \\?\UNC\localhost\c$\gurka */ + sys_memmove(result->data + LP_UNC_PREFIX_SIZE, + &((WCHAR*)result->data)[2], + (actual_length - 1) * sizeof(WCHAR)); + sys_memcpy(result->data, LP_UNC_PREFIX, LP_UNC_PREFIX_SIZE); + actual_length += LP_UNC_PREFIX_LENGTH; + } else if(!is_long_path) { + /* C:\gurka -> \\?\C:\gurka */ sys_memmove(result->data + LP_PREFIX_SIZE, result->data, (actual_length + 1) * sizeof(WCHAR)); - sys_memcpy(result->data, LP_PREFIX, LP_PREFIX_SIZE); + sys_memcpy(result->data, LP_FILE_PREFIX, LP_PREFIX_SIZE); actual_length += LP_PREFIX_LENGTH; } @@ -200,13 +226,19 @@ static int normalize_path_result(ErlNifBinary *path) { ASSERT(length < path->size / sizeof(WCHAR)); /* Get rid of the long-path prefix, if present. */ - if(length >= LP_PREFIX_LENGTH) { - if(!sys_memcmp(path_start, LP_PREFIX, LP_PREFIX_SIZE)) { - length -= LP_PREFIX_LENGTH; - sys_memmove(path_start, &path_start[LP_PREFIX_LENGTH], - length * sizeof(WCHAR)); - } + if(IS_LONG_UNC_PATH(length, path_start)) { + /* The first two characters (\\) are the same for both long and short + * UNC paths. */ + sys_memmove(&path_start[2], &path_start[LP_UNC_PREFIX_LENGTH], + (length - LP_UNC_PREFIX_LENGTH) * sizeof(WCHAR)); + + length -= LP_UNC_PREFIX_LENGTH - 2; + } else if(IS_LONG_PATH(length, path_start)) { + length -= LP_PREFIX_LENGTH; + + sys_memmove(path_start, &path_start[LP_PREFIX_LENGTH], + length * sizeof(WCHAR)); } path_end = &path_start[length]; @@ -318,49 +350,55 @@ static int has_same_mount_point(const efile_path_t *path_a, const efile_path_t * /* Mirrors the PathIsRootW function of the shell API, but doesn't choke on * paths longer than MAX_PATH. */ static int is_path_root(const efile_path_t *path) { - const WCHAR *path_start, *path_end; + const WCHAR *path_start, *path_end, *path_iterator; int length; ASSERT_PATH_FORMAT(path); - path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; - length = PATH_LENGTH(path) - LP_PREFIX_LENGTH; + if(!IS_LONG_UNC_PATH(PATH_LENGTH(path), path->data)) { + path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + length = PATH_LENGTH(path) - LP_PREFIX_LENGTH; - path_end = &path_start[length]; - - if(length == 1) { /* A single \ refers to the root of the current working directory. */ - return IS_SLASH(path_start[0]); - } else if(length == 3 && iswalpha(path_start[0]) && path_start[1] == L':') { - /* Drive letter. */ - return IS_SLASH(path_start[2]); - } else if(length >= 4) { - /* Check whether we're a UNC root, eg. \\server, \\server\share */ - const WCHAR *path_iterator; + if(length == 1) { + return IS_SLASH(path_start[0]); + } - if(!IS_SLASH(path_start[0]) || !IS_SLASH(path_start[1])) { - return 0; + /* Drive letter. */ + if(length == 3 && iswalpha(path_start[0]) && path_start[1] == L':') { + return IS_SLASH(path_start[2]); } - path_iterator = path_start + 2; + return 0; + } - /* Slide to the slash between the server and share names, if present. */ - while(path_iterator < path_end && !IS_SLASH(*path_iterator)) { - path_iterator++; - } + /* Check whether we're a UNC root, eg. \\server, \\server\share */ - /* Slide past the end of the string, stopping at the first slash we - * encounter. */ - do { - path_iterator++; - } while(path_iterator < path_end && !IS_SLASH(*path_iterator)); + path_start = (WCHAR*)path->data + LP_UNC_PREFIX_LENGTH; + length = PATH_LENGTH(path) - LP_UNC_PREFIX_LENGTH; - /* If we're past the end of the string and it didnt't end with a slash, - * then we're a root path. */ - return path_iterator >= path_end && !IS_SLASH(path_start[length - 1]); + path_end = &path_start[length]; + path_iterator = path_start; + + /* Server name must be at least one character. */ + if(length <= 1) { + return 0; } - return 0; + /* Slide to the slash between the server and share names, if present. */ + while(path_iterator < path_end && !IS_SLASH(*path_iterator)) { + path_iterator++; + } + + /* Slide past the end of the string, stopping at the first slash we + * encounter. */ + do { + path_iterator++; + } while(path_iterator < path_end && !IS_SLASH(*path_iterator)); + + /* If we're past the end of the string and it didnt't end with a slash, + * then we're a root path. */ + return path_iterator >= path_end && !IS_SLASH(path_start[length - 1]); } posix_errno_t efile_open(const efile_path_t *path, enum efile_modes_t modes, @@ -687,7 +725,7 @@ static int is_name_surrogate(const efile_path_t *path) { if(handle != INVALID_HANDLE_VALUE) { REPARSE_GUID_DATA_BUFFER reparse_buffer; - LPDWORD unused_length; + DWORD unused_length; BOOL success; success = DeviceIoControl(handle, @@ -1248,11 +1286,22 @@ posix_errno_t efile_set_cwd(const efile_path_t *path) { /* We have to use _wchdir since that's the only function that updates the * per-drive working directory, but it naively assumes that all paths - * starting with \\ are UNC paths, so we have to skip the \\?\-prefix. */ - path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + * starting with \\ are UNC paths, so we have to skip the long-path prefix. + * + * _wchdir doesn't handle long-prefixed UNC paths either so we hand those + * to SetCurrentDirectoryW instead. The per-drive working directory is + * irrelevant for such paths anyway. */ - if(_wchdir(path_start)) { - return windows_to_posix_errno(GetLastError()); + if(!IS_LONG_UNC_PATH(PATH_LENGTH(path), path->data)) { + path_start = (WCHAR*)path->data + LP_PREFIX_LENGTH; + + if(_wchdir(path_start)) { + return windows_to_posix_errno(GetLastError()); + } + } else { + if(!SetCurrentDirectoryW((WCHAR*)path->data)) { + return windows_to_posix_errno(GetLastError()); + } } return 0; @@ -1333,7 +1382,7 @@ posix_errno_t efile_altname(ErlNifEnv *env, const efile_path_t *path, ERL_NIF_TE int name_length; /* Reject path wildcards. */ - if(wcspbrk(&((const WCHAR*)path->data)[4], L"?*")) { + if(wcspbrk(&((const WCHAR*)path->data)[LP_PREFIX_LENGTH], L"?*")) { return ENOENT; } |