Annotation of embedaddon/libiconv/srclib/canonicalize-lgpl.c, revision 1.1.1.3
1.1 misho 1: /* Return the canonical absolute name of a given file.
1.1.1.3 ! misho 2: Copyright (C) 1996-2019 Free Software Foundation, Inc.
1.1 misho 3: This file is part of the GNU C Library.
4:
5: This program is free software: you can redistribute it and/or modify
6: it under the terms of the GNU General Public License as published by
7: the Free Software Foundation; either version 3 of the License, or
8: (at your option) any later version.
9:
10: This program is distributed in the hope that it will be useful,
11: but WITHOUT ANY WARRANTY; without even the implied warranty of
12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13: GNU General Public License for more details.
14:
15: You should have received a copy of the GNU General Public License
1.1.1.3 ! misho 16: along with this program. If not, see <https://www.gnu.org/licenses/>. */
1.1 misho 17:
1.1.1.2 misho 18: #ifndef _LIBC
1.1.1.3 ! misho 19: /* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc
! 20: optimizes away the name == NULL test below. */
! 21: # define _GL_ARG_NONNULL(params)
! 22:
1.1.1.2 misho 23: # define _GL_USE_STDLIB_ALLOC 1
24: # include <config.h>
25: #endif
1.1 misho 26:
1.1.1.2 misho 27: #if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC
1.1 misho 28:
29: /* Specification. */
30: #include <stdlib.h>
31:
1.1.1.2 misho 32: #include <alloca.h>
33: #include <string.h>
34: #include <unistd.h>
1.1 misho 35: #include <limits.h>
36: #if HAVE_SYS_PARAM_H || defined _LIBC
37: # include <sys/param.h>
38: #endif
39: #include <sys/stat.h>
40: #include <errno.h>
1.1.1.2 misho 41: #include <stddef.h>
1.1 misho 42:
43: #ifdef _LIBC
44: # include <shlib-compat.h>
45: #else
46: # define SHLIB_COMPAT(lib, introduced, obsoleted) 0
1.1.1.2 misho 47: # define versioned_symbol(lib, local, symbol, version) extern int dummy
1.1 misho 48: # define compat_symbol(lib, local, symbol, version)
49: # define weak_alias(local, symbol)
50: # define __canonicalize_file_name canonicalize_file_name
1.1.1.2 misho 51: # define __realpath realpath
1.1 misho 52: # include "pathmax.h"
53: # include "malloca.h"
1.1.1.3 ! misho 54: # include "dosname.h"
1.1 misho 55: # if HAVE_GETCWD
1.1.1.2 misho 56: # if IN_RELOCWRAPPER
57: /* When building the relocatable program wrapper, use the system's getcwd
58: function, not the gnulib override, otherwise we would get a link error.
59: */
60: # undef getcwd
61: # endif
1.1.1.3 ! misho 62: # if defined VMS && !defined getcwd
! 63: /* We want the directory in Unix syntax, not in VMS syntax.
! 64: The gnulib override of 'getcwd' takes 2 arguments; the original VMS
! 65: 'getcwd' takes 3 arguments. */
1.1 misho 66: # define __getcwd(buf, max) getcwd (buf, max, 0)
67: # else
68: # define __getcwd getcwd
69: # endif
70: # else
71: # define __getcwd(buf, max) getwd (buf)
72: # endif
73: # define __readlink readlink
1.1.1.2 misho 74: # define __set_errno(e) errno = (e)
75: # ifndef MAXSYMLINKS
76: # ifdef SYMLOOP_MAX
77: # define MAXSYMLINKS SYMLOOP_MAX
78: # else
79: # define MAXSYMLINKS 20
80: # endif
1.1 misho 81: # endif
82: #endif
83:
1.1.1.2 misho 84: #ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
85: # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
86: #endif
87:
1.1.1.3 ! misho 88: /* Define this independently so that stdint.h is not a prerequisite. */
! 89: #ifndef SIZE_MAX
! 90: # define SIZE_MAX ((size_t) -1)
! 91: #endif
! 92:
1.1.1.2 misho 93: #if !FUNC_REALPATH_WORKS || defined _LIBC
1.1.1.3 ! misho 94:
! 95: static void
! 96: alloc_failed (void)
! 97: {
! 98: #if defined _WIN32 && ! defined __CYGWIN__
! 99: /* Avoid errno problem without using the malloc or realloc modules; see:
! 100: https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html */
! 101: errno = ENOMEM;
! 102: #endif
! 103: }
! 104:
1.1 misho 105: /* Return the canonical absolute name of file NAME. A canonical name
1.1.1.3 ! misho 106: does not contain any ".", ".." components nor any repeated path
1.1 misho 107: separators ('/') or symlinks. All path components must exist. If
108: RESOLVED is null, the result is malloc'd; otherwise, if the
1.1.1.3 ! misho 109: canonical name is PATH_MAX chars or more, returns null with 'errno'
1.1 misho 110: set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
111: returns the name in RESOLVED. If the name cannot be resolved and
112: RESOLVED is non-NULL, it contains the path of the first component
113: that cannot be resolved. If the path can be resolved, RESOLVED
114: holds the same value as the value returned. */
115:
116: char *
117: __realpath (const char *name, char *resolved)
118: {
119: char *rpath, *dest, *extra_buf = NULL;
120: const char *start, *end, *rpath_limit;
121: long int path_max;
122: int num_links = 0;
1.1.1.3 ! misho 123: size_t prefix_len;
1.1 misho 124:
125: if (name == NULL)
126: {
127: /* As per Single Unix Specification V2 we must return an error if
1.1.1.2 misho 128: either parameter is a null pointer. We extend this to allow
129: the RESOLVED parameter to be NULL in case the we are expected to
130: allocate the room for the return value. */
1.1 misho 131: __set_errno (EINVAL);
132: return NULL;
133: }
134:
135: if (name[0] == '\0')
136: {
137: /* As per Single Unix Specification V2 we must return an error if
1.1.1.2 misho 138: the name argument points to an empty string. */
1.1 misho 139: __set_errno (ENOENT);
140: return NULL;
141: }
142:
143: #ifdef PATH_MAX
144: path_max = PATH_MAX;
145: #else
146: path_max = pathconf (name, _PC_PATH_MAX);
147: if (path_max <= 0)
1.1.1.2 misho 148: path_max = 8192;
1.1 misho 149: #endif
150:
151: if (resolved == NULL)
152: {
153: rpath = malloc (path_max);
154: if (rpath == NULL)
1.1.1.2 misho 155: {
1.1.1.3 ! misho 156: alloc_failed ();
1.1.1.2 misho 157: return NULL;
158: }
1.1 misho 159: }
160: else
161: rpath = resolved;
162: rpath_limit = rpath + path_max;
163:
1.1.1.3 ! misho 164: /* This is always zero for Posix hosts, but can be 2 for MS-Windows
! 165: and MS-DOS X:/foo/bar file names. */
! 166: prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
! 167:
! 168: if (!IS_ABSOLUTE_FILE_NAME (name))
1.1 misho 169: {
170: if (!__getcwd (rpath, path_max))
1.1.1.2 misho 171: {
172: rpath[0] = '\0';
173: goto error;
174: }
1.1 misho 175: dest = strchr (rpath, '\0');
1.1.1.3 ! misho 176: start = name;
! 177: prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath);
1.1 misho 178: }
179: else
180: {
1.1.1.3 ! misho 181: dest = rpath;
! 182: if (prefix_len)
! 183: {
! 184: memcpy (rpath, name, prefix_len);
! 185: dest += prefix_len;
! 186: }
! 187: *dest++ = '/';
! 188: if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
! 189: {
! 190: if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
! 191: *dest++ = '/';
! 192: *dest = '\0';
! 193: }
! 194: start = name + prefix_len;
1.1 misho 195: }
196:
1.1.1.3 ! misho 197: for (end = start; *start; start = end)
1.1 misho 198: {
199: #ifdef _LIBC
200: struct stat64 st;
201: #else
202: struct stat st;
203: #endif
204:
205: /* Skip sequence of multiple path-separators. */
1.1.1.3 ! misho 206: while (ISSLASH (*start))
1.1.1.2 misho 207: ++start;
1.1 misho 208:
209: /* Find end of path component. */
1.1.1.3 ! misho 210: for (end = start; *end && !ISSLASH (*end); ++end)
1.1.1.2 misho 211: /* Nothing. */;
1.1 misho 212:
213: if (end - start == 0)
1.1.1.2 misho 214: break;
1.1 misho 215: else if (end - start == 1 && start[0] == '.')
1.1.1.2 misho 216: /* nothing */;
1.1 misho 217: else if (end - start == 2 && start[0] == '.' && start[1] == '.')
1.1.1.2 misho 218: {
219: /* Back up to previous component, ignore if at root already. */
1.1.1.3 ! misho 220: if (dest > rpath + prefix_len + 1)
! 221: for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
! 222: continue;
! 223: if (DOUBLE_SLASH_IS_DISTINCT_ROOT
! 224: && dest == rpath + 1 && !prefix_len
! 225: && ISSLASH (*dest) && !ISSLASH (dest[1]))
1.1.1.2 misho 226: dest++;
227: }
1.1 misho 228: else
1.1.1.2 misho 229: {
230: size_t new_size;
1.1 misho 231:
1.1.1.3 ! misho 232: if (!ISSLASH (dest[-1]))
1.1.1.2 misho 233: *dest++ = '/';
1.1 misho 234:
1.1.1.2 misho 235: if (dest + (end - start) >= rpath_limit)
236: {
237: ptrdiff_t dest_offset = dest - rpath;
238: char *new_rpath;
239:
240: if (resolved)
241: {
242: __set_errno (ENAMETOOLONG);
1.1.1.3 ! misho 243: if (dest > rpath + prefix_len + 1)
1.1.1.2 misho 244: dest--;
245: *dest = '\0';
246: goto error;
247: }
248: new_size = rpath_limit - rpath;
249: if (end - start + 1 > path_max)
250: new_size += end - start + 1;
251: else
252: new_size += path_max;
253: new_rpath = (char *) realloc (rpath, new_size);
254: if (new_rpath == NULL)
255: {
1.1.1.3 ! misho 256: alloc_failed ();
1.1.1.2 misho 257: goto error;
258: }
259: rpath = new_rpath;
260: rpath_limit = rpath + new_size;
1.1 misho 261:
1.1.1.2 misho 262: dest = rpath + dest_offset;
263: }
1.1 misho 264:
265: #ifdef _LIBC
1.1.1.2 misho 266: dest = __mempcpy (dest, start, end - start);
1.1 misho 267: #else
1.1.1.2 misho 268: memcpy (dest, start, end - start);
269: dest += end - start;
1.1 misho 270: #endif
1.1.1.2 misho 271: *dest = '\0';
1.1 misho 272:
1.1.1.3 ! misho 273: /* FIXME: if lstat fails with errno == EOVERFLOW,
! 274: the entry exists. */
1.1 misho 275: #ifdef _LIBC
1.1.1.2 misho 276: if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
1.1 misho 277: #else
1.1.1.2 misho 278: if (lstat (rpath, &st) < 0)
1.1 misho 279: #endif
1.1.1.2 misho 280: goto error;
1.1 misho 281:
1.1.1.2 misho 282: if (S_ISLNK (st.st_mode))
283: {
284: char *buf;
285: size_t len;
1.1.1.3 ! misho 286: ssize_t n;
1.1.1.2 misho 287:
288: if (++num_links > MAXSYMLINKS)
289: {
290: __set_errno (ELOOP);
291: goto error;
292: }
293:
294: buf = malloca (path_max);
295: if (!buf)
296: {
1.1.1.3 ! misho 297: __set_errno (ENOMEM);
1.1.1.2 misho 298: goto error;
299: }
300:
301: n = __readlink (rpath, buf, path_max - 1);
302: if (n < 0)
303: {
304: int saved_errno = errno;
305: freea (buf);
1.1.1.3 ! misho 306: __set_errno (saved_errno);
1.1.1.2 misho 307: goto error;
308: }
309: buf[n] = '\0';
310:
311: if (!extra_buf)
312: {
313: extra_buf = malloca (path_max);
314: if (!extra_buf)
315: {
316: freea (buf);
1.1.1.3 ! misho 317: __set_errno (ENOMEM);
1.1.1.2 misho 318: goto error;
319: }
320: }
321:
322: len = strlen (end);
1.1.1.3 ! misho 323: /* Check that n + len + 1 doesn't overflow and is <= path_max. */
! 324: if (n >= SIZE_MAX - len || n + len >= path_max)
1.1.1.2 misho 325: {
326: freea (buf);
327: __set_errno (ENAMETOOLONG);
328: goto error;
329: }
330:
331: /* Careful here, end may be a pointer into extra_buf... */
332: memmove (&extra_buf[n], end, len + 1);
333: name = end = memcpy (extra_buf, buf, n);
334:
1.1.1.3 ! misho 335: if (IS_ABSOLUTE_FILE_NAME (buf))
1.1.1.2 misho 336: {
1.1.1.3 ! misho 337: size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
! 338:
! 339: if (pfxlen)
! 340: memcpy (rpath, buf, pfxlen);
! 341: dest = rpath + pfxlen;
! 342: *dest++ = '/'; /* It's an absolute symlink */
! 343: if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
! 344: {
! 345: if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
! 346: *dest++ = '/';
! 347: *dest = '\0';
! 348: }
! 349: /* Install the new prefix to be in effect hereafter. */
! 350: prefix_len = pfxlen;
1.1.1.2 misho 351: }
352: else
353: {
354: /* Back up to previous component, ignore if at root
355: already: */
1.1.1.3 ! misho 356: if (dest > rpath + prefix_len + 1)
! 357: for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
! 358: continue;
1.1.1.2 misho 359: if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
1.1.1.3 ! misho 360: && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
1.1.1.2 misho 361: dest++;
362: }
363: }
364: else if (!S_ISDIR (st.st_mode) && *end != '\0')
365: {
366: __set_errno (ENOTDIR);
367: goto error;
368: }
369: }
1.1 misho 370: }
1.1.1.3 ! misho 371: if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1]))
1.1 misho 372: --dest;
1.1.1.3 ! misho 373: if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len
! 374: && ISSLASH (*dest) && !ISSLASH (dest[1]))
1.1.1.2 misho 375: dest++;
1.1 misho 376: *dest = '\0';
377:
378: if (extra_buf)
379: freea (extra_buf);
380:
1.1.1.2 misho 381: return rpath;
1.1 misho 382:
383: error:
384: {
385: int saved_errno = errno;
386: if (extra_buf)
387: freea (extra_buf);
1.1.1.2 misho 388: if (resolved == NULL)
1.1 misho 389: free (rpath);
1.1.1.3 ! misho 390: __set_errno (saved_errno);
1.1 misho 391: }
392: return NULL;
393: }
394: versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
1.1.1.2 misho 395: #endif /* !FUNC_REALPATH_WORKS || defined _LIBC */
1.1 misho 396:
397:
398: #if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
399: char *
1.1.1.2 misho 400: attribute_compat_text_section
1.1 misho 401: __old_realpath (const char *name, char *resolved)
402: {
403: if (resolved == NULL)
404: {
405: __set_errno (EINVAL);
406: return NULL;
407: }
408:
409: return __realpath (name, resolved);
410: }
411: compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
412: #endif
413:
414:
415: char *
416: __canonicalize_file_name (const char *name)
417: {
418: return __realpath (name, NULL);
419: }
420: weak_alias (__canonicalize_file_name, canonicalize_file_name)
421:
422: #else
423:
424: /* This declaration is solely to ensure that after preprocessing
425: this file is never empty. */
426: typedef int dummy;
427:
428: #endif
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