release/src/router/libiconv/srclib/relocwrapper.c

   1 /* Relocating wrapper program.
   2    Copyright (C) 2003, 2005-2007, 2009-2011 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
   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
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Dependencies:
  19    relocwrapper
  20     -> progname
  21     -> progreloc
  22         -> areadlink
  23            -> careadlinkat
  24              -> allocator
  25              -> readlink
  26         -> canonicalize-lgpl
  27            -> malloca
  28            -> readlink
  29     -> relocatable
  30     -> setenv
  31        -> malloca
  32     -> c-ctype
  33
  34    Macros that need to be set while compiling this file:
  35      - ENABLE_RELOCATABLE 1
  36      - INSTALLPREFIX the base installation directory
  37      - INSTALLDIR the directory into which this program is installed
  38      - LIBPATHVAR the platform dependent runtime library path variable
  39      - LIBDIRS a comma-terminated list of strings representing the list of
  40        directories that contain the libraries at installation time
  41
  42    We don't want to internationalize this wrapper because then it would
  43    depend on libintl and therefore need relocation itself.  So use only
  44    libc functions, no gettext(), no error(), no xmalloc(), no xsetenv().
  45  */
  46
  47 #define _GL_USE_STDLIB_ALLOC 1
  48 #include <config.h>
  49
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54 #include <errno.h>
  55
  56 #include "progname.h"
  57 #include "relocatable.h"
  58 #include "c-ctype.h"
  59 #include "verify.h"
  60
  61 /* Use the system functions, not the gnulib overrides in this file.  */
  62 #undef fprintf
  63
  64 /* Return a copy of the filename, with an extra ".bin" at the end.
  65    More generally, it replaces "${EXEEXT}" at the end with ".bin${EXEEXT}".  */
  66 static char *
  67 add_dotbin (const char *filename)
  68 {
  69   size_t filename_len = strlen (filename);
  70   char *result = (char *) malloc (filename_len + 4 + 1);
  71
  72   if (result != NULL)
  73     {
  74       if (sizeof (EXEEXT) > sizeof (""))
  75         {
  76           /* EXEEXT handling.  */
  77           const size_t exeext_len = sizeof (EXEEXT) - sizeof ("");
  78           static const char exeext[] = EXEEXT;
  79           if (filename_len > exeext_len)
  80             {
  81               /* Compare using an inlined copy of c_strncasecmp(), because
  82                  the filenames may have undergone a case conversion since
  83                  they were packaged.  In other words, EXEEXT may be ".exe"
  84                  on one system and ".EXE" on another.  */
  85               const char *s1 = filename + filename_len - exeext_len;
  86               const char *s2 = exeext;
  87               for (; *s1 != '\0'; s1++, s2++)
  88                 {
  89                   unsigned char c1 = *s1;
  90                   unsigned char c2 = *s2;
  91                   if (c_tolower (c1) != c_tolower (c2))
  92                     goto simple_append;
  93                 }
  94               /* Insert ".bin" before EXEEXT or its equivalent.  */
  95               memcpy (result, filename, filename_len - exeext_len);
  96               memcpy (result + filename_len - exeext_len, ".bin", 4);
  97               memcpy (result + filename_len - exeext_len + 4,
  98                       filename + filename_len - exeext_len,
  99                       exeext_len + 1);
 100               return result;
 101             }
 102         }
 103      simple_append:
 104       /* Simply append ".bin".  */
 105       memcpy (result, filename, filename_len);
 106       memcpy (result + filename_len, ".bin", 4 + 1);
 107       return result;
 108     }
 109   else
 110     {
 111       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
 112       exit (1);
 113     }
 114 }
 115
 116 /* List of directories that contain the libraries.  */
 117 static const char *libdirs[] = { LIBDIRS NULL };
 118 /* Verify that at least one directory is given.  */
 119 verify (sizeof (libdirs) / sizeof (libdirs[0]) > 1);
 120
 121 /* Relocate the list of directories that contain the libraries.  */
 122 static void
 123 relocate_libdirs ()
 124 {
 125   size_t i;
 126
 127   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
 128     libdirs[i] = relocate (libdirs[i]);
 129 }
 130
 131 /* Activate the list of directories in the LIBPATHVAR.  */
 132 static void
 133 activate_libdirs ()
 134 {
 135   const char *old_value;
 136   size_t total;
 137   size_t i;
 138   char *value;
 139   char *p;
 140
 141   old_value = getenv (LIBPATHVAR);
 142   if (old_value == NULL)
 143     old_value = "";
 144
 145   total = 0;
 146   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
 147     total += strlen (libdirs[i]) + 1;
 148   total += strlen (old_value) + 1;
 149
 150   value = (char *) malloc (total);
 151   if (value == NULL)
 152     {
 153       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
 154       exit (1);
 155     }
 156   p = value;
 157   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
 158     {
 159       size_t len = strlen (libdirs[i]);
 160       memcpy (p, libdirs[i], len);
 161       p += len;
 162       *p++ = ':';
 163     }
 164   if (old_value[0] != '\0')
 165     strcpy (p, old_value);
 166   else
 167     p[-1] = '\0';
 168
 169   if (setenv (LIBPATHVAR, value, 1) < 0)
 170     {
 171       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
 172       exit (1);
 173     }
 174 }
 175
 176 int
 177 main (int argc, char *argv[])
 178 {
 179   char *full_program_name;
 180
 181   /* Set the program name and perform preparations for
 182      get_full_program_name() and relocate().  */
 183   set_program_name_and_installdir (argv[0], INSTALLPREFIX, INSTALLDIR);
 184
 185   /* Get the full program path.  (Important if accessed through a symlink.)  */
 186   full_program_name = get_full_program_name ();
 187   if (full_program_name == NULL)
 188     full_program_name = argv[0];
 189
 190   /* Invoke the real program, with suffix ".bin".  */
 191   argv[0] = add_dotbin (full_program_name);
 192   relocate_libdirs ();
 193   activate_libdirs ();
 194   execv (argv[0], argv);
 195   fprintf (stderr, "%s: could not execute %s: %s\n",
 196            program_name, argv[0], strerror (errno));
 197   exit (127);
 198 }