428
+ − 1 /*
+ − 2 * realpath.c -- canonicalize pathname by removing symlinks
+ − 3 * Copyright (C) 1993 Rick Sladkey <jrs@world.std.com>
2526
+ − 4 * Copyright (C) 2001, 2002, 2004 Ben Wing.
428
+ − 5 *
+ − 6
+ − 7 This file is part of XEmacs.
+ − 8
+ − 9 XEmacs is free software; you can redistribute it and/or modify it
+ − 10 under the terms of the GNU General Public License as published by the
+ − 11 Free Software Foundation; either version 2, or (at your option) any
+ − 12 later version.
+ − 13
+ − 14 XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ − 15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ − 16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ − 17 for more details.
+ − 18
+ − 19 You should have received a copy of the GNU General Public License
+ − 20 along with XEmacs; see the file COPYING. If not, write to
+ − 21 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ − 22 Boston, MA 02111-1307, USA. */
+ − 23
+ − 24 /* Synched up with: Not in FSF. */
+ − 25
771
+ − 26 /* This file has been Mule-ized, June 2001 by Ben Wing.
+ − 27
+ − 28 Everything in this file now works in terms of internal, not external,
+ − 29 data. This is the only way to be safe, and it makes the code cleaner. */
+ − 30
428
+ − 31 #include <config.h>
446
+ − 32 #include "lisp.h"
442
+ − 33
2526
+ − 34 #include "profile.h"
+ − 35
558
+ − 36 #include "sysfile.h"
1116
+ − 37 #include "sysdir.h"
428
+ − 38
771
+ − 39 #define MAX_READLINKS 32
+ − 40
1116
+ − 41 #ifdef WIN32_ANY
446
+ − 42 #include "syswindows.h"
+ − 43 #ifndef ELOOP
+ − 44 #define ELOOP 10062 /* = WSAELOOP in winsock.h */
+ − 45 #endif
1116
+ − 46 #endif
+ − 47
2526
+ − 48 Lisp_Object QSin_qxe_realpath;
+ − 49
446
+ − 50 /* Length of start of absolute filename. */
+ − 51 static int
1116
+ − 52 abs_start (const Ibyte *name)
446
+ − 53 {
1116
+ − 54 #ifdef WIN32_ANY
446
+ − 55 if (isalpha (*name) && IS_DEVICE_SEP (name[1])
+ − 56 && IS_DIRECTORY_SEP (name[2]))
+ − 57 return 3;
+ − 58 else if (IS_DIRECTORY_SEP (*name))
+ − 59 return IS_DIRECTORY_SEP (name[1]) ? 2 : 1;
+ − 60 else
+ − 61 return 0;
1116
+ − 62 #else /* not WIN32_ANY */
+ − 63 return IS_DIRECTORY_SEP (*name) ? 1 : 0;
+ − 64 #endif
446
+ − 65 }
1116
+ − 66
2526
+ − 67 /* Find real name of a file by resolving symbolic links and/or shortcuts
+ − 68 under Windows (.LNK links), if such support is enabled.
+ − 69
+ − 70 If no link found, and LINKS_ONLY is false, look up the correct case in
+ − 71 the file system of the last component.
1116
+ − 72
+ − 73 Under Windows, UNC servers and shares are lower-cased. Directories must
+ − 74 be given without trailing '/'. One day, this could read Win2K's reparse
2526
+ − 75 points.
+ − 76
+ − 77 Returns length of characters copied info BUF.
+ − 78 DOES NOT ZERO TERMINATE!!!!!
+ − 79 */
1116
+ − 80
+ − 81 static int
2526
+ − 82 readlink_or_correct_case (const Ibyte *name, Ibyte *buf, Bytecount size,
3042
+ − 83 #ifndef WIN32_ANY
3044
+ − 84 Boolint UNUSED (links_only)
3042
+ − 85 #else
3044
+ − 86 Boolint links_only
3042
+ − 87 #endif
3044
+ − 88 )
1116
+ − 89 {
+ − 90 #ifndef WIN32_ANY
2526
+ − 91 return qxe_readlink (name, buf, (size_t) size);
1116
+ − 92 #else
+ − 93 # ifdef CYGWIN
+ − 94 Ibyte *tmp;
2526
+ − 95 int n = qxe_readlink (name, buf, (size_t) size);
1116
+ − 96 if (n >= 0 || errno != EINVAL)
+ − 97 return n;
+ − 98
+ − 99 /* The file may exist, but isn't a symlink. Try to find the
+ − 100 right name. */
2367
+ − 101 tmp =
+ − 102 alloca_ibytes (cygwin_posix_to_win32_path_list_buf_size ((char *) name));
1116
+ − 103 cygwin_posix_to_win32_path_list ((char *) name, (char *) tmp);
+ − 104 name = tmp;
2526
+ − 105 # else
+ − 106 if (mswindows_shortcuts_are_symlinks)
+ − 107 {
+ − 108 Ibyte *tmp = mswindows_read_link (name);
+ − 109
+ − 110 if (tmp != NULL)
+ − 111 {
+ − 112 /* Fucking fixed buffers. */
+ − 113 Bytecount len = qxestrlen (tmp);
+ − 114 if (len > size)
+ − 115 {
+ − 116 errno = ENAMETOOLONG;
+ − 117 return -1;
+ − 118 }
+ − 119 memcpy (buf, tmp, len);
+ − 120 xfree (tmp, Ibyte *);
+ − 121 return len;
+ − 122 }
+ − 123 }
1116
+ − 124 # endif
+ − 125
2526
+ − 126 if (links_only)
+ − 127 {
+ − 128 errno = EINVAL;
+ − 129 return -1;
+ − 130 }
+ − 131
1116
+ − 132 {
+ − 133 int len = 0;
+ − 134 int err = 0;
+ − 135 const Ibyte *lastname;
+ − 136 int count = 0;
1204
+ − 137 const Ibyte *nn;
1116
+ − 138 DECLARE_EISTRING (result);
+ − 139
+ − 140 assert (*name);
+ − 141
+ − 142 /* Sort of check we have a valid filename. */
+ − 143 if (qxestrpbrk (name, "*?|<>\""))
+ − 144 {
+ − 145 errno = ENOENT;
+ − 146 return -1;
+ − 147 }
2421
+ − 148 else if (qxestrlen (name) >= PATH_MAX_INTERNAL)
1116
+ − 149 {
+ − 150 errno = ENAMETOOLONG;
+ − 151 return -1;
+ − 152 }
+ − 153
+ − 154 /* Find start of filename */
+ − 155 lastname = name + qxestrlen (name);
+ − 156 while (lastname > name && !IS_DIRECTORY_SEP (lastname[-1]))
+ − 157 --lastname;
+ − 158
+ − 159 /* Count slashes in unc path */
+ − 160 if (abs_start (name) == 2)
1204
+ − 161 for (nn = name; *nn; nn++)
+ − 162 if (IS_DIRECTORY_SEP (*nn))
1116
+ − 163 count++;
+ − 164
+ − 165 if (count >= 2 && count < 4)
+ − 166 {
+ − 167 eicpy_rawz (result, lastname);
+ − 168 eilwr (result);
+ − 169 }
+ − 170 else
+ − 171 {
+ − 172 WIN32_FIND_DATAW find_data;
+ − 173 Extbyte *nameext;
+ − 174 HANDLE dir_handle;
+ − 175
+ − 176 C_STRING_TO_TSTR (name, nameext);
+ − 177 dir_handle = qxeFindFirstFile (nameext, &find_data);
+ − 178 if (dir_handle == INVALID_HANDLE_VALUE)
+ − 179 {
+ − 180 errno = ENOENT;
+ − 181 return -1;
+ − 182 }
+ − 183 eicpy_ext (result, (Extbyte *) find_data.cFileName, Qmswindows_tstr);
+ − 184 FindClose (dir_handle);
+ − 185 }
+ − 186
2526
+ − 187 if ((len = eilen (result)) <= size)
1116
+ − 188 {
+ − 189 DECLARE_EISTRING (eilastname);
+ − 190
+ − 191 eicpy_rawz (eilastname, lastname);
+ − 192 if (eicmp_ei (eilastname, result) == 0)
2526
+ − 193 /* Signal that the name is already OK. */
+ − 194 err = EINVAL;
1116
+ − 195 else
2526
+ − 196 memcpy (buf, eidata (result), len);
1116
+ − 197 }
+ − 198 else
+ − 199 err = ENAMETOOLONG;
+ − 200
+ − 201 errno = err;
+ − 202 return err ? -1 : len;
+ − 203 }
+ − 204 #endif /* WIN32_ANY */
+ − 205 }
446
+ − 206
771
+ − 207 /* Mule Note: This function works with and returns
2526
+ − 208 internally-formatted strings.
+ − 209
+ − 210 if LINKS_ONLY is true, don't do case canonicalization under
+ − 211 Windows. */
440
+ − 212
867
+ − 213 Ibyte *
2526
+ − 214 qxe_realpath (const Ibyte *path, Ibyte *resolved_path, Boolint links_only)
428
+ − 215 {
2421
+ − 216 Ibyte copy_path[PATH_MAX_INTERNAL];
867
+ − 217 Ibyte *new_path = resolved_path;
+ − 218 Ibyte *max_path;
2526
+ − 219 Ibyte *retval = NULL;
1116
+ − 220 #if defined (HAVE_READLINK) || defined (WIN32_ANY)
428
+ − 221 int readlinks = 0;
2421
+ − 222 Ibyte link_path[PATH_MAX_INTERNAL];
428
+ − 223 int n;
1116
+ − 224 int abslen = abs_start (path);
428
+ − 225 #endif
+ − 226
2526
+ − 227 PROFILE_DECLARE ();
+ − 228
+ − 229 PROFILE_RECORD_ENTERING_SECTION (QSin_qxe_realpath);
+ − 230
1760
+ − 231 restart:
+ − 232
428
+ − 233 /* Make a copy of the source path since we may need to modify it. */
771
+ − 234 qxestrcpy (copy_path, path);
428
+ − 235 path = copy_path;
2421
+ − 236 max_path = copy_path + PATH_MAX_INTERNAL - 2;
446
+ − 237
819
+ − 238 if (0)
+ − 239 ;
1116
+ − 240 #ifdef WIN32_ANY
446
+ − 241 /* Check for c:/... or //server/... */
988
+ − 242 else if (abslen == 3 || abslen == 2)
428
+ − 243 {
462
+ − 244 /* Make sure drive letter is lowercased. */
1116
+ − 245 if (abslen == 3)
+ − 246 {
+ − 247 *new_path = tolower (*path);
+ − 248 new_path++;
+ − 249 path++;
+ − 250 abslen--;
+ − 251 }
988
+ − 252 /* Coerce directory chars. */
1116
+ − 253 while (abslen-- > 0)
+ − 254 {
+ − 255 if (IS_DIRECTORY_SEP (*path))
+ − 256 *new_path++ = DIRECTORY_SEP;
+ − 257 else
+ − 258 *new_path++ = *path;
+ − 259 path++;
+ − 260 }
428
+ − 261 }
819
+ − 262 #endif
+ − 263 #ifdef WIN32_NATIVE
446
+ − 264 /* No drive letter, but a beginning slash? Prepend drive letter. */
+ − 265 else if (abslen == 1)
428
+ − 266 {
2421
+ − 267 get_initial_directory (new_path, PATH_MAX_INTERNAL - 1);
428
+ − 268 new_path += 3;
+ − 269 path++;
+ − 270 }
446
+ − 271 /* Just a path name, prepend the current directory */
1116
+ − 272 else
428
+ − 273 {
2421
+ − 274 get_initial_directory (new_path, PATH_MAX_INTERNAL - 1);
771
+ − 275 new_path += qxestrlen (new_path);
446
+ − 276 if (!IS_DIRECTORY_SEP (new_path[-1]))
+ − 277 *new_path++ = DIRECTORY_SEP;
428
+ − 278 }
+ − 279 #else
771
+ − 280 /* If it's a relative pathname use get_initial_directory for starters. */
819
+ − 281 else if (abslen == 0)
428
+ − 282 {
2421
+ − 283 get_initial_directory (new_path, PATH_MAX_INTERNAL - 1);
771
+ − 284 new_path += qxestrlen (new_path);
446
+ − 285 if (!IS_DIRECTORY_SEP (new_path[-1]))
+ − 286 *new_path++ = DIRECTORY_SEP;
428
+ − 287 }
+ − 288 else
+ − 289 {
446
+ − 290 /* Copy first directory sep. May have two on cygwin. */
771
+ − 291 qxestrncpy (new_path, path, abslen);
446
+ − 292 new_path += abslen;
+ − 293 path += abslen;
428
+ − 294 }
+ − 295 #endif
+ − 296 /* Expand each slash-separated pathname component. */
+ − 297 while (*path != '\0')
+ − 298 {
+ − 299 /* Ignore stray "/". */
446
+ − 300 if (IS_DIRECTORY_SEP (*path))
428
+ − 301 {
+ − 302 path++;
+ − 303 continue;
+ − 304 }
+ − 305
+ − 306 if (*path == '.')
+ − 307 {
+ − 308 /* Ignore ".". */
446
+ − 309 if (path[1] == '\0' || IS_DIRECTORY_SEP (path[1]))
428
+ − 310 {
+ − 311 path++;
+ − 312 continue;
+ − 313 }
+ − 314
442
+ − 315 /* Handle ".." */
+ − 316 if (path[1] == '.' &&
446
+ − 317 (path[2] == '\0' || IS_DIRECTORY_SEP (path[2])))
428
+ − 318 {
442
+ − 319 path += 2;
428
+ − 320
442
+ − 321 /* Ignore ".." at root. */
1116
+ − 322 if (new_path == resolved_path + abs_start (resolved_path))
442
+ − 323 continue;
428
+ − 324
442
+ − 325 /* Handle ".." by backing up. */
446
+ − 326 --new_path;
+ − 327 while (!IS_DIRECTORY_SEP (new_path[-1]))
+ − 328 --new_path;
442
+ − 329 continue;
428
+ − 330 }
+ − 331 }
+ − 332
+ − 333 /* Safely copy the next pathname component. */
446
+ − 334 while (*path != '\0' && !IS_DIRECTORY_SEP (*path))
428
+ − 335 {
+ − 336 if (path > max_path)
+ − 337 {
+ − 338 errno = ENAMETOOLONG;
2526
+ − 339 goto done;
428
+ − 340 }
+ − 341 *new_path++ = *path++;
+ − 342 }
+ − 343
1116
+ − 344 #if defined (HAVE_READLINK) || defined (WIN32_ANY)
771
+ − 345 /* See if latest pathname component is a symlink or needs case
+ − 346 correction. */
428
+ − 347 *new_path = '\0';
2526
+ − 348 n = readlink_or_correct_case (resolved_path, link_path,
+ − 349 PATH_MAX_INTERNAL - 1, links_only);
428
+ − 350
+ − 351 if (n < 0)
+ − 352 {
771
+ − 353 /* EINVAL means the file exists but isn't a symlink or doesn't
+ − 354 need case correction. */
1116
+ − 355 #ifdef WIN32_ANY
462
+ − 356 if (errno != EINVAL && errno != ENOENT)
+ − 357 #else
+ − 358 if (errno != EINVAL)
+ − 359 #endif
2526
+ − 360 goto done;
428
+ − 361 }
+ − 362 else
+ − 363 {
+ − 364 /* Protect against infinite loops. */
+ − 365 if (readlinks++ > MAX_READLINKS)
+ − 366 {
+ − 367 errno = ELOOP;
2526
+ − 368 goto done;
428
+ − 369 }
+ − 370
+ − 371 /* Note: readlink doesn't add the null byte. */
+ − 372 link_path[n] = '\0';
446
+ − 373
1760
+ − 374 abslen = abs_start (link_path);
+ − 375 if (abslen > 0)
+ − 376 {
+ − 377 /* Start over for an absolute symlink. */
+ − 378 new_path = resolved_path;
+ − 379 qxestrcat (link_path, path);
+ − 380 path = link_path;
+ − 381 goto restart;
+ − 382 }
+ − 383
+ − 384 /* Otherwise back up over this component. */
+ − 385 for (--new_path; !IS_DIRECTORY_SEP (*new_path); --new_path)
+ − 386 assert (new_path > resolved_path);
428
+ − 387
+ − 388 /* Safe sex check. */
2421
+ − 389 if (qxestrlen (path) + n >= PATH_MAX_INTERNAL)
428
+ − 390 {
+ − 391 errno = ENAMETOOLONG;
2526
+ − 392 goto done;
428
+ − 393 }
+ − 394
+ − 395 /* Insert symlink contents into path. */
771
+ − 396 qxestrcat (link_path, path);
+ − 397 qxestrcpy (copy_path, link_path);
428
+ − 398 path = copy_path;
+ − 399 }
1116
+ − 400 #endif /* HAVE_READLINK || WIN32_ANY */
446
+ − 401 *new_path++ = DIRECTORY_SEP;
428
+ − 402 }
+ − 403
+ − 404 /* Delete trailing slash but don't whomp a lone slash. */
1116
+ − 405 if (new_path != resolved_path + abs_start (resolved_path) &&
771
+ − 406 IS_DIRECTORY_SEP (new_path[-1]))
428
+ − 407 new_path--;
+ − 408
+ − 409 /* Make sure it's null terminated. */
+ − 410 *new_path = '\0';
446
+ − 411
2526
+ − 412 retval = resolved_path;
+ − 413 done:
+ − 414 PROFILE_RECORD_EXITING_SECTION (QSin_qxe_realpath);
+ − 415 return retval;
428
+ − 416 }
2526
+ − 417
+ − 418 void
+ − 419 vars_of_realpath (void)
+ − 420 {
+ − 421 QSin_qxe_realpath =
+ − 422 build_msg_string ("(in qxe_realpath)");
+ − 423 staticpro (&QSin_qxe_realpath);
+ − 424 }
