release/src/router/libiconv/lib/relocatable.c

   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  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