1 /* Relocating wrapper program.
2    Copyright (C) 2003, 2005-2007 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         -> xreadlink
23            -> areadlink
24               -> readlink
25         -> canonicalize-lgpl
26            -> malloca
27     -> relocatable
28     -> setenv
29        -> malloca
30     -> strerror
31     -> c-ctype
32 
33    Macros that need to be set while compiling this file:
34      - ENABLE_RELOCATABLE 1
35      - INSTALLPREFIX the base installation directory
36      - INSTALLDIR the directory into which this program is installed
37      - LIBPATHVAR the platform dependent runtime library path variable
38      - LIBDIRS a comma-terminated list of strings representing the list of
39        directories that contain the libraries at installation time
40 
41    We don't want to internationalize this wrapper because then it would
42    depend on libintl and therefore need relocation itself.  So use only
43    libc functions, no gettext(), no error(), no xmalloc(), no xsetenv().
44  */
45 
46 #include <config.h>
47 
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <errno.h>
53 
54 #include "progname.h"
55 #include "relocatable.h"
56 #include "setenv.h"
57 #include "c-ctype.h"
58 
59 /* Return a copy of the filename, with an extra ".bin" at the end.
60    More generally, it replaces "${EXEEXT}" at the end with ".bin${EXEEXT}".  */
61 static char *
add_dotbin(const char * filename)62 add_dotbin (const char *filename)
63 {
64   size_t filename_len = strlen (filename);
65   char *result = (char *) malloc (filename_len + 4 + 1);
66 
67   if (result != NULL)
68     {
69       if (sizeof (EXEEXT) > sizeof (""))
70 	{
71 	  /* EXEEXT handling.  */
72 	  const size_t exeext_len = sizeof (EXEEXT) - sizeof ("");
73 	  static const char exeext[] = EXEEXT;
74 	  if (filename_len > exeext_len)
75 	    {
76 	      /* Compare using an inlined copy of c_strncasecmp(), because
77 		 the filenames may have undergone a case conversion since
78 		 they were packaged.  In other words, EXEEXT may be ".exe"
79 		 on one system and ".EXE" on another.  */
80 	      const char *s1 = filename + filename_len - exeext_len;
81 	      const char *s2 = exeext;
82 	      for (; *s1 != '\0'; s1++, s2++)
83 		{
84 		  unsigned char c1 = *s1;
85 		  unsigned char c2 = *s2;
86 		  if (c_tolower (c1) != c_tolower (c2))
87 		    goto simple_append;
88 		}
89 	      /* Insert ".bin" before EXEEXT or its equivalent.  */
90 	      memcpy (result, filename, filename_len - exeext_len);
91 	      memcpy (result + filename_len - exeext_len, ".bin", 4);
92 	      memcpy (result + filename_len - exeext_len + 4,
93 		      filename + filename_len - exeext_len,
94 		      exeext_len + 1);
95 	      return result;
96 	    }
97 	}
98      simple_append:
99       /* Simply append ".bin".  */
100       memcpy (result, filename, filename_len);
101       memcpy (result + filename_len, ".bin", 4 + 1);
102       return result;
103     }
104   else
105     {
106       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
107       exit (1);
108     }
109 }
110 
111 /* List of directories that contain the libraries.  */
112 static const char *libdirs[] = { LIBDIRS NULL };
113 /* Verify that at least one directory is given.  */
114 typedef int verify1[2 * (sizeof (libdirs) / sizeof (libdirs[0]) > 1) - 1];
115 
116 /* Relocate the list of directories that contain the libraries.  */
117 static void
relocate_libdirs()118 relocate_libdirs ()
119 {
120   size_t i;
121 
122   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
123     libdirs[i] = relocate (libdirs[i]);
124 }
125 
126 /* Activate the list of directories in the LIBPATHVAR.  */
127 static void
activate_libdirs()128 activate_libdirs ()
129 {
130   const char *old_value;
131   size_t total;
132   size_t i;
133   char *value;
134   char *p;
135 
136   old_value = getenv (LIBPATHVAR);
137   if (old_value == NULL)
138     old_value = "";
139 
140   total = 0;
141   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
142     total += strlen (libdirs[i]) + 1;
143   total += strlen (old_value) + 1;
144 
145   value = (char *) malloc (total);
146   if (value == NULL)
147     {
148       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
149       exit (1);
150     }
151   p = value;
152   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
153     {
154       size_t len = strlen (libdirs[i]);
155       memcpy (p, libdirs[i], len);
156       p += len;
157       *p++ = ':';
158     }
159   if (old_value[0] != '\0')
160     strcpy (p, old_value);
161   else
162     p[-1] = '\0';
163 
164   if (setenv (LIBPATHVAR, value, 1) < 0)
165     {
166       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
167       exit (1);
168     }
169 }
170 
171 int
main(int argc,char * argv[])172 main (int argc, char *argv[])
173 {
174   char *full_program_name;
175 
176   /* Set the program name and perform preparations for
177      get_full_program_name() and relocate().  */
178   set_program_name_and_installdir (argv[0], INSTALLPREFIX, INSTALLDIR);
179 
180   /* Get the full program path.  (Important if accessed through a symlink.)  */
181   full_program_name = get_full_program_name ();
182   if (full_program_name == NULL)
183     full_program_name = argv[0];
184 
185   /* Invoke the real program, with suffix ".bin".  */
186   argv[0] = add_dotbin (full_program_name);
187   relocate_libdirs ();
188   activate_libdirs ();
189   execv (argv[0], argv);
190   fprintf (stderr, "%s: could not execute %s: %s\n",
191 	   program_name, argv[0], strerror (errno));
192   exit (127);
193 }
194