Theodore Ts'o | b0cacab | 2004-11-30 19:00:19 -0500 | [diff] [blame] | 1 | /* Provide relocatable packages. |
| 2 | Copyright (C) 2003 Free Software Foundation, Inc. |
| 3 | Written by Bruno Haible <bruno@clisp.org>, 2003. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify it |
| 6 | under the terms of the GNU Library General Public License as published |
| 7 | by the Free Software Foundation; either version 2, or (at your option) |
| 8 | 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 GNU |
| 13 | Library General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Library General Public |
| 16 | License along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
| 18 | USA. */ |
| 19 | |
| 20 | |
| 21 | /* Tell glibc's <stdio.h> to provide a prototype for getline(). |
| 22 | This must come before <config.h> because <config.h> may include |
| 23 | <features.h>, and once <features.h> has been included, it's too late. */ |
| 24 | #ifndef _GNU_SOURCE |
| 25 | # define _GNU_SOURCE 1 |
| 26 | #endif |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | # include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | /* Specification. */ |
| 33 | #include "relocatable.h" |
| 34 | |
| 35 | #if ENABLE_RELOCATABLE |
| 36 | |
| 37 | #include <stddef.h> |
| 38 | #include <stdio.h> |
| 39 | #include <stdlib.h> |
| 40 | #include <string.h> |
| 41 | |
| 42 | #ifdef NO_XMALLOC |
| 43 | # define xmalloc malloc |
| 44 | #else |
| 45 | # include "xalloc.h" |
| 46 | #endif |
| 47 | |
| 48 | #if defined _WIN32 || defined __WIN32__ |
| 49 | # define WIN32_LEAN_AND_MEAN |
| 50 | # include <windows.h> |
| 51 | #endif |
| 52 | |
| 53 | #if DEPENDS_ON_LIBCHARSET |
| 54 | # include <libcharset.h> |
| 55 | #endif |
| 56 | #if DEPENDS_ON_LIBICONV && HAVE_ICONV |
| 57 | # include <iconv.h> |
| 58 | #endif |
| 59 | #if DEPENDS_ON_LIBINTL && ENABLE_NLS |
| 60 | # include <libintl.h> |
| 61 | #endif |
| 62 | |
| 63 | /* Faked cheap 'bool'. */ |
| 64 | #undef bool |
| 65 | #undef false |
| 66 | #undef true |
| 67 | #define bool int |
| 68 | #define false 0 |
| 69 | #define true 1 |
| 70 | |
| 71 | /* Pathname support. |
| 72 | ISSLASH(C) tests whether C is a directory separator character. |
| 73 | IS_PATH_WITH_DIR(P) tests whether P contains a directory specification. |
| 74 | */ |
| 75 | #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__ |
| 76 | /* Win32, OS/2, DOS */ |
| 77 | # define ISSLASH(C) ((C) == '/' || (C) == '\\') |
| 78 | # define HAS_DEVICE(P) \ |
| 79 | ((((P)[0] >= 'A' && (P)[0] <= 'Z') || ((P)[0] >= 'a' && (P)[0] <= 'z')) \ |
| 80 | && (P)[1] == ':') |
| 81 | # define IS_PATH_WITH_DIR(P) \ |
| 82 | (strchr (P, '/') != NULL || strchr (P, '\\') != NULL || HAS_DEVICE (P)) |
| 83 | # define FILESYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0) |
| 84 | #else |
| 85 | /* Unix */ |
| 86 | # define ISSLASH(C) ((C) == '/') |
| 87 | # define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL) |
| 88 | # define FILESYSTEM_PREFIX_LEN(P) 0 |
| 89 | #endif |
| 90 | |
| 91 | /* Original installation prefix. */ |
| 92 | static char *orig_prefix; |
| 93 | static size_t orig_prefix_len; |
| 94 | /* Current installation prefix. */ |
| 95 | static char *curr_prefix; |
| 96 | static size_t curr_prefix_len; |
| 97 | /* These prefixes do not end in a slash. Anything that will be concatenated |
| 98 | to them must start with a slash. */ |
| 99 | |
| 100 | /* Sets the original and the current installation prefix of this module. |
| 101 | Relocation simply replaces a pathname starting with the original prefix |
| 102 | by the corresponding pathname with the current prefix instead. Both |
| 103 | prefixes should be directory names without trailing slash (i.e. use "" |
| 104 | instead of "/"). */ |
| 105 | static void |
| 106 | set_this_relocation_prefix (const char *orig_prefix_arg, |
| 107 | const char *curr_prefix_arg) |
| 108 | { |
| 109 | if (orig_prefix_arg != NULL && curr_prefix_arg != NULL |
| 110 | /* Optimization: if orig_prefix and curr_prefix are equal, the |
| 111 | relocation is a nop. */ |
| 112 | && strcmp (orig_prefix_arg, curr_prefix_arg) != 0) |
| 113 | { |
| 114 | /* Duplicate the argument strings. */ |
| 115 | char *memory; |
| 116 | |
| 117 | orig_prefix_len = strlen (orig_prefix_arg); |
| 118 | curr_prefix_len = strlen (curr_prefix_arg); |
| 119 | memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1); |
| 120 | #ifdef NO_XMALLOC |
| 121 | if (memory != NULL) |
| 122 | #endif |
| 123 | { |
| 124 | memcpy (memory, orig_prefix_arg, orig_prefix_len + 1); |
| 125 | orig_prefix = memory; |
| 126 | memory += orig_prefix_len + 1; |
| 127 | memcpy (memory, curr_prefix_arg, curr_prefix_len + 1); |
| 128 | curr_prefix = memory; |
| 129 | return; |
| 130 | } |
| 131 | } |
| 132 | orig_prefix = NULL; |
| 133 | curr_prefix = NULL; |
| 134 | /* Don't worry about wasted memory here - this function is usually only |
| 135 | called once. */ |
| 136 | } |
| 137 | |
| 138 | /* Sets the original and the current installation prefix of the package. |
| 139 | Relocation simply replaces a pathname starting with the original prefix |
| 140 | by the corresponding pathname with the current prefix instead. Both |
| 141 | prefixes should be directory names without trailing slash (i.e. use "" |
| 142 | instead of "/"). */ |
| 143 | void |
| 144 | set_relocation_prefix (const char *orig_prefix_arg, const char *curr_prefix_arg) |
| 145 | { |
| 146 | set_this_relocation_prefix (orig_prefix_arg, curr_prefix_arg); |
| 147 | |
| 148 | /* Now notify all dependent libraries. */ |
| 149 | #if DEPENDS_ON_LIBCHARSET |
| 150 | libcharset_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg); |
| 151 | #endif |
| 152 | #if DEPENDS_ON_LIBICONV && HAVE_ICONV && _LIBICONV_VERSION >= 0x0109 |
| 153 | libiconv_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg); |
| 154 | #endif |
| 155 | #if DEPENDS_ON_LIBINTL && ENABLE_NLS && defined libintl_set_relocation_prefix |
| 156 | libintl_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg); |
| 157 | #endif |
| 158 | } |
| 159 | |
| 160 | #if !defined IN_LIBRARY || (defined PIC && defined INSTALLDIR) |
| 161 | |
| 162 | /* Convenience function: |
| 163 | Computes the current installation prefix, based on the original |
| 164 | installation prefix, the original installation directory of a particular |
| 165 | file, and the current pathname of this file. Returns NULL upon failure. */ |
| 166 | #ifdef IN_LIBRARY |
| 167 | #define compute_curr_prefix local_compute_curr_prefix |
| 168 | static |
| 169 | #endif |
| 170 | const char * |
| 171 | compute_curr_prefix (const char *orig_installprefix, |
| 172 | const char *orig_installdir, |
| 173 | const char *curr_pathname) |
| 174 | { |
| 175 | const char *curr_installdir; |
| 176 | const char *rel_installdir; |
| 177 | |
| 178 | if (curr_pathname == NULL) |
| 179 | return NULL; |
| 180 | |
| 181 | /* Determine the relative installation directory, relative to the prefix. |
| 182 | This is simply the difference between orig_installprefix and |
| 183 | orig_installdir. */ |
| 184 | if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix)) |
| 185 | != 0) |
| 186 | /* Shouldn't happen - nothing should be installed outside $(prefix). */ |
| 187 | return NULL; |
| 188 | rel_installdir = orig_installdir + strlen (orig_installprefix); |
| 189 | |
| 190 | /* Determine the current installation directory. */ |
| 191 | { |
| 192 | const char *p_base = curr_pathname + FILESYSTEM_PREFIX_LEN (curr_pathname); |
| 193 | const char *p = curr_pathname + strlen (curr_pathname); |
| 194 | char *q; |
| 195 | |
| 196 | while (p > p_base) |
| 197 | { |
| 198 | p--; |
| 199 | if (ISSLASH (*p)) |
| 200 | break; |
| 201 | } |
| 202 | |
| 203 | q = (char *) xmalloc (p - curr_pathname + 1); |
| 204 | #ifdef NO_XMALLOC |
| 205 | if (q == NULL) |
| 206 | return NULL; |
| 207 | #endif |
| 208 | memcpy (q, curr_pathname, p - curr_pathname); |
| 209 | q[p - curr_pathname] = '\0'; |
| 210 | curr_installdir = q; |
| 211 | } |
| 212 | |
| 213 | /* Compute the current installation prefix by removing the trailing |
| 214 | rel_installdir from it. */ |
| 215 | { |
| 216 | const char *rp = rel_installdir + strlen (rel_installdir); |
| 217 | const char *cp = curr_installdir + strlen (curr_installdir); |
| 218 | const char *cp_base = |
| 219 | curr_installdir + FILESYSTEM_PREFIX_LEN (curr_installdir); |
| 220 | |
| 221 | while (rp > rel_installdir && cp > cp_base) |
| 222 | { |
| 223 | bool same = false; |
| 224 | const char *rpi = rp; |
| 225 | const char *cpi = cp; |
| 226 | |
| 227 | while (rpi > rel_installdir && cpi > cp_base) |
| 228 | { |
| 229 | rpi--; |
| 230 | cpi--; |
| 231 | if (ISSLASH (*rpi) || ISSLASH (*cpi)) |
| 232 | { |
| 233 | if (ISSLASH (*rpi) && ISSLASH (*cpi)) |
| 234 | same = true; |
| 235 | break; |
| 236 | } |
| 237 | #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__ |
| 238 | /* Win32, OS/2, DOS - case insignificant filesystem */ |
| 239 | if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi) |
| 240 | != (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi)) |
| 241 | break; |
| 242 | #else |
| 243 | if (*rpi != *cpi) |
| 244 | break; |
| 245 | #endif |
| 246 | } |
| 247 | if (!same) |
| 248 | break; |
| 249 | /* The last pathname component was the same. opi and cpi now point |
| 250 | to the slash before it. */ |
| 251 | rp = rpi; |
| 252 | cp = cpi; |
| 253 | } |
| 254 | |
| 255 | if (rp > rel_installdir) |
| 256 | /* Unexpected: The curr_installdir does not end with rel_installdir. */ |
| 257 | return NULL; |
| 258 | |
| 259 | { |
| 260 | size_t curr_prefix_len = cp - curr_installdir; |
| 261 | char *curr_prefix; |
| 262 | |
| 263 | curr_prefix = (char *) xmalloc (curr_prefix_len + 1); |
| 264 | #ifdef NO_XMALLOC |
| 265 | if (curr_prefix == NULL) |
| 266 | return NULL; |
| 267 | #endif |
| 268 | memcpy (curr_prefix, curr_installdir, curr_prefix_len); |
| 269 | curr_prefix[curr_prefix_len] = '\0'; |
| 270 | |
| 271 | return curr_prefix; |
| 272 | } |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | #endif /* !IN_LIBRARY || PIC */ |
| 277 | |
| 278 | #if defined PIC && defined INSTALLDIR |
| 279 | |
| 280 | /* Full pathname of shared library, or NULL. */ |
| 281 | static char *shared_library_fullname; |
| 282 | |
| 283 | #if defined _WIN32 || defined __WIN32__ |
| 284 | |
| 285 | /* Determine the full pathname of the shared library when it is loaded. */ |
| 286 | |
| 287 | BOOL WINAPI |
| 288 | DllMain (HINSTANCE module_handle, DWORD event, LPVOID reserved) |
| 289 | { |
| 290 | (void) reserved; |
| 291 | |
| 292 | if (event == DLL_PROCESS_ATTACH) |
| 293 | { |
| 294 | /* The DLL is being loaded into an application's address range. */ |
| 295 | static char location[MAX_PATH]; |
| 296 | |
| 297 | if (!GetModuleFileName (module_handle, location, sizeof (location))) |
| 298 | /* Shouldn't happen. */ |
| 299 | return FALSE; |
| 300 | |
| 301 | if (!IS_PATH_WITH_DIR (location)) |
| 302 | /* Shouldn't happen. */ |
| 303 | return FALSE; |
| 304 | |
| 305 | shared_library_fullname = strdup (location); |
| 306 | } |
| 307 | |
| 308 | return TRUE; |
| 309 | } |
| 310 | |
| 311 | #else /* Unix */ |
| 312 | |
| 313 | static void |
| 314 | find_shared_library_fullname () |
| 315 | { |
| 316 | #if defined __linux__ && __GLIBC__ >= 2 |
| 317 | /* Linux has /proc/self/maps. glibc 2 has the getline() function. */ |
| 318 | FILE *fp; |
| 319 | |
| 320 | /* Open the current process' maps file. It describes one VMA per line. */ |
| 321 | fp = fopen ("/proc/self/maps", "r"); |
| 322 | if (fp) |
| 323 | { |
| 324 | unsigned long address = (unsigned long) &find_shared_library_fullname; |
| 325 | for (;;) |
| 326 | { |
| 327 | unsigned long start, end; |
| 328 | int c; |
| 329 | |
| 330 | if (fscanf (fp, "%lx-%lx", &start, &end) != 2) |
| 331 | break; |
| 332 | if (address >= start && address <= end - 1) |
| 333 | { |
| 334 | /* Found it. Now see if this line contains a filename. */ |
| 335 | while (c = getc (fp), c != EOF && c != '\n' && c != '/') |
| 336 | continue; |
| 337 | if (c == '/') |
| 338 | { |
| 339 | size_t size; |
| 340 | int len; |
| 341 | |
| 342 | ungetc (c, fp); |
| 343 | shared_library_fullname = NULL; size = 0; |
| 344 | len = getline (&shared_library_fullname, &size, fp); |
| 345 | if (len >= 0) |
| 346 | { |
| 347 | /* Success: filled shared_library_fullname. */ |
| 348 | if (len > 0 && shared_library_fullname[len - 1] == '\n') |
| 349 | shared_library_fullname[len - 1] = '\0'; |
| 350 | } |
| 351 | } |
| 352 | break; |
| 353 | } |
| 354 | while (c = getc (fp), c != EOF && c != '\n') |
| 355 | continue; |
| 356 | } |
| 357 | fclose (fp); |
| 358 | } |
| 359 | #endif |
| 360 | } |
| 361 | |
| 362 | #endif /* WIN32 / Unix */ |
| 363 | |
| 364 | /* Return the full pathname of the current shared library. |
| 365 | Return NULL if unknown. |
| 366 | Guaranteed to work only on Linux and Woe32. */ |
| 367 | static char * |
| 368 | get_shared_library_fullname () |
| 369 | { |
| 370 | #if !(defined _WIN32 || defined __WIN32__) |
| 371 | static bool tried_find_shared_library_fullname; |
| 372 | if (!tried_find_shared_library_fullname) |
| 373 | { |
| 374 | find_shared_library_fullname (); |
| 375 | tried_find_shared_library_fullname = true; |
| 376 | } |
| 377 | #endif |
| 378 | return shared_library_fullname; |
| 379 | } |
| 380 | |
| 381 | #endif /* PIC */ |
| 382 | |
| 383 | /* Returns the pathname, relocated according to the current installation |
| 384 | directory. */ |
| 385 | const char * |
| 386 | relocate (const char *pathname) |
| 387 | { |
| 388 | #if defined PIC && defined INSTALLDIR |
| 389 | static int initialized; |
| 390 | |
| 391 | /* Initialization code for a shared library. */ |
| 392 | if (!initialized) |
| 393 | { |
| 394 | /* At this point, orig_prefix and curr_prefix likely have already been |
| 395 | set through the main program's set_program_name_and_installdir |
| 396 | function. This is sufficient in the case that the library has |
| 397 | initially been installed in the same orig_prefix. But we can do |
| 398 | better, to also cover the cases that 1. it has been installed |
| 399 | in a different prefix before being moved to orig_prefix and (later) |
| 400 | to curr_prefix, 2. unlike the program, it has not moved away from |
| 401 | orig_prefix. */ |
| 402 | const char *orig_installprefix = INSTALLPREFIX; |
| 403 | const char *orig_installdir = INSTALLDIR; |
| 404 | const char *curr_prefix_better; |
| 405 | |
| 406 | curr_prefix_better = |
| 407 | compute_curr_prefix (orig_installprefix, orig_installdir, |
| 408 | get_shared_library_fullname ()); |
| 409 | if (curr_prefix_better == NULL) |
| 410 | curr_prefix_better = curr_prefix; |
| 411 | |
| 412 | set_relocation_prefix (orig_installprefix, curr_prefix_better); |
| 413 | |
| 414 | initialized = 1; |
| 415 | } |
| 416 | #endif |
| 417 | |
| 418 | /* Note: It is not necessary to perform case insensitive comparison here, |
| 419 | even for DOS-like filesystems, because the pathname argument was |
| 420 | typically created from the same Makefile variable as orig_prefix came |
| 421 | from. */ |
| 422 | if (orig_prefix != NULL && curr_prefix != NULL |
| 423 | && strncmp (pathname, orig_prefix, orig_prefix_len) == 0) |
| 424 | { |
| 425 | if (pathname[orig_prefix_len] == '\0') |
| 426 | /* pathname equals orig_prefix. */ |
| 427 | return curr_prefix; |
| 428 | if (ISSLASH (pathname[orig_prefix_len])) |
| 429 | { |
| 430 | /* pathname starts with orig_prefix. */ |
| 431 | const char *pathname_tail = &pathname[orig_prefix_len]; |
| 432 | char *result = |
| 433 | (char *) xmalloc (curr_prefix_len + strlen (pathname_tail) + 1); |
| 434 | |
| 435 | #ifdef NO_XMALLOC |
| 436 | if (result != NULL) |
| 437 | #endif |
| 438 | { |
| 439 | memcpy (result, curr_prefix, curr_prefix_len); |
| 440 | strcpy (result + curr_prefix_len, pathname_tail); |
| 441 | return result; |
| 442 | } |
| 443 | } |
| 444 | } |
| 445 | /* Nothing to relocate. */ |
| 446 | return pathname; |
| 447 | } |
| 448 | |
| 449 | #endif |