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Diffstat (limited to '')
| -rw-r--r-- | lib/stat.c | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/lib/stat.c b/lib/stat.c new file mode 100644 index 0000000..9d3965d --- /dev/null +++ b/lib/stat.c @@ -0,0 +1,440 @@ +/* Work around platform bugs in stat. + Copyright (C) 2009-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Eric Blake and Bruno Haible. */ + +/* If the user's config.h happens to include <sys/stat.h>, let it include only + the system's <sys/stat.h> here, so that orig_stat doesn't recurse to + rpl_stat. */ +#define __need_system_sys_stat_h +#include <config.h> + +/* Get the original definition of stat. It might be defined as a macro. */ +#include <sys/types.h> +#include <sys/stat.h> +#undef __need_system_sys_stat_h + +#if defined _WIN32 && ! defined __CYGWIN__ +# define WINDOWS_NATIVE +#endif + +#if !defined WINDOWS_NATIVE + +static int +orig_stat (const char *filename, struct stat *buf) +{ + return stat (filename, buf); +} + +#endif + +/* Specification. */ +#ifdef __osf__ +/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc + eliminates this include because of the preliminary #include <sys/stat.h> + above. */ +# include "sys/stat.h" +#else +# include <sys/stat.h> +#endif + +#include "stat-time.h" + +#include <errno.h> +#include <limits.h> +#include <stdbool.h> +#include <string.h> +#include "filename.h" +#include "malloca.h" +#include "verify.h" + +#ifdef WINDOWS_NATIVE +# define WIN32_LEAN_AND_MEAN +# include <windows.h> +# include "stat-w32.h" +/* Don't assume that UNICODE is not defined. */ +# undef WIN32_FIND_DATA +# define WIN32_FIND_DATA WIN32_FIND_DATAA +# undef CreateFile +# define CreateFile CreateFileA +# undef FindFirstFile +# define FindFirstFile FindFirstFileA +#endif + +#ifdef WINDOWS_NATIVE +/* Return TRUE if the given file name denotes an UNC root. */ +static BOOL +is_unc_root (const char *rname) +{ + /* Test whether it has the syntax '\\server\share'. */ + if (ISSLASH (rname[0]) && ISSLASH (rname[1])) + { + /* It starts with two slashes. Find the next slash. */ + const char *p = rname + 2; + const char *q = p; + while (*q != '\0' && !ISSLASH (*q)) + q++; + if (q > p && *q != '\0') + { + /* Found the next slash at q. */ + q++; + const char *r = q; + while (*r != '\0' && !ISSLASH (*r)) + r++; + if (r > q && *r == '\0') + return TRUE; + } + } + return FALSE; +} +#endif + +/* Store information about NAME into ST. Work around bugs with + trailing slashes. Mingw has other bugs (such as st_ino always + being 0 on success) which this wrapper does not work around. But + at least this implementation provides the ability to emulate fchdir + correctly. */ + +int +rpl_stat (char const *name, struct stat *buf) +{ +#ifdef WINDOWS_NATIVE + /* Fill the fields ourselves, because the original stat function returns + values for st_atime, st_mtime, st_ctime that depend on the current time + zone. See + <https://lists.gnu.org/r/bug-gnulib/2017-04/msg00134.html> */ + /* XXX Should we convert to wchar_t* and prepend '\\?\', in order to work + around length limitations + <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file> ? */ + + /* POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13> + specifies: "More than two leading <slash> characters shall be treated as + a single <slash> character." */ + if (ISSLASH (name[0]) && ISSLASH (name[1]) && ISSLASH (name[2])) + { + name += 2; + while (ISSLASH (name[1])) + name++; + } + + size_t len = strlen (name); + size_t drive_prefix_len = (HAS_DEVICE (name) ? 2 : 0); + + /* Remove trailing slashes (except the very first one, at position + drive_prefix_len), but remember their presence. */ + size_t rlen; + bool check_dir = false; + + rlen = len; + while (rlen > drive_prefix_len && ISSLASH (name[rlen-1])) + { + check_dir = true; + if (rlen == drive_prefix_len + 1) + break; + rlen--; + } + + /* Handle '' and 'C:'. */ + if (!check_dir && rlen == drive_prefix_len) + { + errno = ENOENT; + return -1; + } + + /* Handle '\\'. */ + if (rlen == 1 && ISSLASH (name[0]) && len >= 2) + { + errno = ENOENT; + return -1; + } + + const char *rname; + char *malloca_rname; + if (rlen == len) + { + rname = name; + malloca_rname = NULL; + } + else + { + malloca_rname = malloca (rlen + 1); + if (malloca_rname == NULL) + { + errno = ENOMEM; + return -1; + } + memcpy (malloca_rname, name, rlen); + malloca_rname[rlen] = '\0'; + rname = malloca_rname; + } + + /* There are two ways to get at the requested information: + - by scanning the parent directory and examining the relevant + directory entry, + - by opening the file directly. + The first approach fails for root directories (e.g. 'C:\') and + UNC root directories (e.g. '\\server\share'). + The second approach fails for some system files (e.g. 'C:\pagefile.sys' + and 'C:\hiberfil.sys'): ERROR_SHARING_VIOLATION. + The second approach gives more information (in particular, correct + st_dev, st_ino, st_nlink fields). + So we use the second approach and, as a fallback except for root and + UNC root directories, also the first approach. */ + { + int ret; + + { + /* Approach based on the file. */ + + /* Open a handle to the file. + CreateFile + <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea> + <https://docs.microsoft.com/en-us/windows/desktop/FileIO/creating-and-opening-files> */ + HANDLE h = + CreateFile (rname, + FILE_READ_ATTRIBUTES, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, + NULL, + OPEN_EXISTING, + /* FILE_FLAG_POSIX_SEMANTICS (treat file names that differ only + in case as different) makes sense only when applied to *all* + filesystem operations. */ + FILE_FLAG_BACKUP_SEMANTICS /* | FILE_FLAG_POSIX_SEMANTICS */, + NULL); + if (h != INVALID_HANDLE_VALUE) + { + ret = _gl_fstat_by_handle (h, rname, buf); + CloseHandle (h); + goto done; + } + } + + /* Test for root and UNC root directories. */ + if ((rlen == drive_prefix_len + 1 && ISSLASH (rname[drive_prefix_len])) + || is_unc_root (rname)) + goto failed; + + /* Fallback. */ + { + /* Approach based on the directory entry. */ + + if (strchr (rname, '?') != NULL || strchr (rname, '*') != NULL) + { + /* Other Windows API functions would fail with error + ERROR_INVALID_NAME. */ + if (malloca_rname != NULL) + freea (malloca_rname); + errno = ENOENT; + return -1; + } + + /* Get the details about the directory entry. This can be done through + FindFirstFile + <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfilea> + <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> + or through + FindFirstFileEx with argument FindExInfoBasic + <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfileexa> + <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ne-minwinbase-findex_info_levels> + <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> */ + WIN32_FIND_DATA info; + HANDLE h = FindFirstFile (rname, &info); + if (h == INVALID_HANDLE_VALUE) + goto failed; + + /* Test for error conditions before starting to fill *buf. */ + if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0) + { + FindClose (h); + if (malloca_rname != NULL) + freea (malloca_rname); + errno = EOVERFLOW; + return -1; + } + +# if _GL_WINDOWS_STAT_INODES + buf->st_dev = 0; +# if _GL_WINDOWS_STAT_INODES == 2 + buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0; +# else /* _GL_WINDOWS_STAT_INODES == 1 */ + buf->st_ino = 0; +# endif +# else + /* st_ino is not wide enough for identifying a file on a device. + Without st_ino, st_dev is pointless. */ + buf->st_dev = 0; + buf->st_ino = 0; +# endif + + /* st_mode. */ + unsigned int mode = + /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ? */ + ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG) + | S_IREAD_UGO + | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO); + if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) + { + /* Determine whether the file is executable by looking at the file + name suffix. */ + if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0) + { + const char *last_dot = NULL; + const char *p; + for (p = info.cFileName; *p != '\0'; p++) + if (*p == '.') + last_dot = p; + if (last_dot != NULL) + { + const char *suffix = last_dot + 1; + if (_stricmp (suffix, "exe") == 0 + || _stricmp (suffix, "bat") == 0 + || _stricmp (suffix, "cmd") == 0 + || _stricmp (suffix, "com") == 0) + mode |= S_IEXEC_UGO; + } + } + } + buf->st_mode = mode; + + /* st_nlink. Ignore hard links here. */ + buf->st_nlink = 1; + + /* There's no easy way to map the Windows SID concept to an integer. */ + buf->st_uid = 0; + buf->st_gid = 0; + + /* st_rdev is irrelevant for normal files and directories. */ + buf->st_rdev = 0; + + /* st_size. */ + if (sizeof (buf->st_size) <= 4) + /* Range check already done above. */ + buf->st_size = info.nFileSizeLow; + else + buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow; + + /* st_atime, st_mtime, st_ctime. */ +# if _GL_WINDOWS_STAT_TIMESPEC + buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime); + buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime); + buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime); +# else + buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime); + buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime); + buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime); +# endif + + FindClose (h); + + ret = 0; + } + + done: + if (ret >= 0 && check_dir && !S_ISDIR (buf->st_mode)) + { + errno = ENOTDIR; + ret = -1; + } + if (malloca_rname != NULL) + { + int saved_errno = errno; + freea (malloca_rname); + errno = saved_errno; + } + return ret; + } + + failed: + { + DWORD error = GetLastError (); + #if 0 + fprintf (stderr, "rpl_stat error 0x%x\n", (unsigned int) error); + #endif + + if (malloca_rname != NULL) + freea (malloca_rname); + + switch (error) + { + /* Some of these errors probably cannot happen with the specific flags + that we pass to CreateFile. But who knows... */ + case ERROR_FILE_NOT_FOUND: /* The last component of rname does not exist. */ + case ERROR_PATH_NOT_FOUND: /* Some directory component in rname does not exist. */ + case ERROR_BAD_PATHNAME: /* rname is such as '\\server'. */ + case ERROR_BAD_NET_NAME: /* rname is such as '\\server\nonexistentshare'. */ + case ERROR_INVALID_NAME: /* rname contains wildcards, misplaced colon, etc. */ + case ERROR_DIRECTORY: + errno = ENOENT; + break; + + case ERROR_ACCESS_DENIED: /* rname is such as 'C:\System Volume Information\foo'. */ + case ERROR_SHARING_VIOLATION: /* rname is such as 'C:\pagefile.sys' (second approach only). */ + /* XXX map to EACCES or EPERM? */ + errno = EACCES; + break; + + case ERROR_OUTOFMEMORY: + errno = ENOMEM; + break; + + case ERROR_WRITE_PROTECT: + errno = EROFS; + break; + + case ERROR_WRITE_FAULT: + case ERROR_READ_FAULT: + case ERROR_GEN_FAILURE: + errno = EIO; + break; + + case ERROR_BUFFER_OVERFLOW: + case ERROR_FILENAME_EXCED_RANGE: + errno = ENAMETOOLONG; + break; + + case ERROR_DELETE_PENDING: /* XXX map to EACCES or EPERM? */ + errno = EPERM; + break; + + default: + errno = EINVAL; + break; + } + + return -1; + } +#else + int result = orig_stat (name, buf); + if (result == 0) + { +# if REPLACE_FUNC_STAT_FILE + /* Solaris 9 mistakenly succeeds when given a non-directory with a + trailing slash. */ + if (!S_ISDIR (buf->st_mode)) + { + size_t len = strlen (name); + if (ISSLASH (name[len - 1])) + { + errno = ENOTDIR; + return -1; + } + } +# endif /* REPLACE_FUNC_STAT_FILE */ + result = stat_time_normalize (result, buf); + } + return result; +#endif +} |