1 /* Relocating wrapper program.
2    Copyright (C) 2003, 2005-2007, 2009-2019 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 <https://www.gnu.org/licenses/>.  */
17 
18 /* Dependencies:
19    relocwrapper
20     -> progname
21     -> progreloc
22        -> areadlink
23           -> careadlinkat
24              -> allocator
25           -> readlink
26              -> stat
27                 -> dosname
28                 -> pathmax
29                 -> verify
30        -> canonicalize-lgpl
31           -> malloca
32           -> lstat
33           -> readlink
34     -> relocatable
35     -> setenv
36        -> malloca
37     -> fprintf-posix [ignore, cut dependency tree here]
38     -> strerror [ignore, cut dependency tree here]
39     -> c-ctype
40 
41    Macros that need to be set while compiling this file:
42      - ENABLE_RELOCATABLE 1
43      - INSTALLPREFIX the base installation directory
44      - INSTALLDIR the directory into which this program is installed
45      - LIBPATHVAR the platform dependent runtime library path variable
46      - LIBDIRS a comma-terminated list of strings representing the list of
47        directories that contain the libraries at installation time
48 
49    We don't want to internationalize this wrapper because then it would
50    depend on libintl and therefore need relocation itself.  So use only
51    libc functions, no gettext(), no error(), no xmalloc(), no xsetenv().
52  */
53 
54 #define _GL_USE_STDLIB_ALLOC 1
55 #include <config.h>
56 
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <errno.h>
62 
63 #include "progname.h"
64 #include "relocatable.h"
65 #include "c-ctype.h"
66 #include "verify.h"
67 
68 /* Use the system functions, not the gnulib overrides in this file.  */
69 #undef fprintf
70 #undef strerror
71 
72 /* Return a copy of the filename, with an extra ".bin" at the end.
73    More generally, it replaces "${EXEEXT}" at the end with ".bin${EXEEXT}".  */
74 static char *
add_dotbin(const char * filename)75 add_dotbin (const char *filename)
76 {
77   size_t filename_len = strlen (filename);
78   char *result = (char *) malloc (filename_len + 4 + 1);
79 
80   if (result != NULL)
81     {
82       if (sizeof (EXEEXT) > sizeof (""))
83         {
84           /* EXEEXT handling.  */
85           const size_t exeext_len = sizeof (EXEEXT) - sizeof ("");
86           static const char exeext[] = EXEEXT;
87           if (filename_len > exeext_len)
88             {
89               /* Compare using an inlined copy of c_strncasecmp(), because
90                  the filenames may have undergone a case conversion since
91                  they were packaged.  In other words, EXEEXT may be ".exe"
92                  on one system and ".EXE" on another.  */
93               const char *s1 = filename + filename_len - exeext_len;
94               const char *s2 = exeext;
95               for (; *s1 != '\0'; s1++, s2++)
96                 {
97                   unsigned char c1 = *s1;
98                   unsigned char c2 = *s2;
99                   if (c_tolower (c1) != c_tolower (c2))
100                     goto simple_append;
101                 }
102               /* Insert ".bin" before EXEEXT or its equivalent.  */
103               memcpy (result, filename, filename_len - exeext_len);
104               memcpy (result + filename_len - exeext_len, ".bin", 4);
105               memcpy (result + filename_len - exeext_len + 4,
106                       filename + filename_len - exeext_len,
107                       exeext_len + 1);
108               return result;
109             }
110         }
111      simple_append:
112       /* Simply append ".bin".  */
113       memcpy (result, filename, filename_len);
114       memcpy (result + filename_len, ".bin", 4 + 1);
115       return result;
116     }
117   else
118     {
119       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
120       exit (1);
121     }
122 }
123 
124 /* List of directories that contain the libraries.  */
125 static const char *libdirs[] = { LIBDIRS NULL };
126 /* Verify that at least one directory is given.  */
127 verify (sizeof (libdirs) / sizeof (libdirs[0]) > 1);
128 
129 /* Relocate the list of directories that contain the libraries.  */
130 static void
relocate_libdirs()131 relocate_libdirs ()
132 {
133   size_t i;
134 
135   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
136     libdirs[i] = relocate (libdirs[i]);
137 }
138 
139 /* Activate the list of directories in the LIBPATHVAR.  */
140 static void
activate_libdirs()141 activate_libdirs ()
142 {
143   const char *old_value;
144   size_t total;
145   size_t i;
146   char *value;
147   char *p;
148 
149   old_value = getenv (LIBPATHVAR);
150   if (old_value == NULL)
151     old_value = "";
152 
153   total = 0;
154   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
155     total += strlen (libdirs[i]) + 1;
156   total += strlen (old_value) + 1;
157 
158   value = (char *) malloc (total);
159   if (value == NULL)
160     {
161       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
162       exit (1);
163     }
164   p = value;
165   for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
166     {
167       size_t len = strlen (libdirs[i]);
168       memcpy (p, libdirs[i], len);
169       p += len;
170       *p++ = ':';
171     }
172   if (old_value[0] != '\0')
173     strcpy (p, old_value);
174   else
175     p[-1] = '\0';
176 
177   if (setenv (LIBPATHVAR, value, 1) < 0)
178     {
179       fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
180       exit (1);
181     }
182 }
183 
184 int
main(int argc,char * argv[])185 main (int argc, char *argv[])
186 {
187   char *full_program_name;
188 
189   /* Set the program name and perform preparations for
190      get_full_program_name() and relocate().  */
191   set_program_name_and_installdir (argv[0], INSTALLPREFIX, INSTALLDIR);
192 
193   /* Get the full program path.  (Important if accessed through a symlink.)  */
194   full_program_name = get_full_program_name ();
195   if (full_program_name == NULL)
196     full_program_name = argv[0];
197 
198   /* Invoke the real program, with suffix ".bin".  */
199   argv[0] = add_dotbin (full_program_name);
200   relocate_libdirs ();
201   activate_libdirs ();
202   execv (argv[0], argv);
203   fprintf (stderr, "%s: could not execute %s: %s\n",
204            program_name, argv[0], strerror (errno));
205   exit (127);
206 }
207