1 /* Relocating wrapper program.
2 Copyright (C) 2003, 2005-2007, 2009-2023 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 -> stat
23 -> filename
24 -> pathmax
25 -> verify
26 -> areadlink
27 -> careadlinkat
28 -> allocator
29 -> readlink
30 -> stat
31 -> canonicalize-lgpl
32 -> c-bool
33 -> libc-config
34 -> errno
35 -> fcntl-h
36 -> sys_stat
37 -> unistd
38 -> eloop-threshold
39 -> filename
40 -> idx
41 -> intprops
42 -> scratch_buffer
43 -> malloc-posix
44 -> realloc-posix
45 -> free-posix
46 -> pathmax
47 -> mempcpy
48 -> rawmemchr
49 -> readlink
50 -> stat
51 -> double-slash-root
52 -> relocatable
53 -> setenv
54 -> malloca
55 -> fprintf-posix [ignore, cut dependency tree here]
56 -> strerror [ignore, cut dependency tree here]
57 -> c-ctype
58
59 Macros that need to be set while compiling this file:
60 - ENABLE_RELOCATABLE 1
61 - INSTALLPREFIX the base installation directory
62 - INSTALLDIR the directory into which this program is installed
63 - LIBPATHVAR the platform dependent runtime library path variable
64 - LIBDIRS a comma-terminated list of strings representing the list of
65 directories that contain the libraries at installation time
66
67 We don't want to internationalize this wrapper because then it would
68 depend on libintl and therefore need relocation itself. So use only
69 libc functions, no gettext(), no error(), no xmalloc(), no xsetenv().
70 */
71
72 #define _GL_USE_STDLIB_ALLOC 1
73 #include <config.h>
74
75 #include <stdio.h>
76 #include <stdlib.h>
77 #include <string.h>
78 #include <unistd.h>
79 #include <errno.h>
80
81 #include "progname.h"
82 #include "relocatable.h"
83 #include "c-ctype.h"
84
85 /* Use the system functions, not the gnulib overrides in this file. */
86 #undef fprintf
87 #undef strerror
88
89 /* Return a copy of the filename, with an extra ".bin" at the end.
90 More generally, it replaces "${EXEEXT}" at the end with ".bin${EXEEXT}". */
91 static char *
92 add_dotbin (const char *filename)
93 {
94 size_t filename_len = strlen (filename);
95 char *result = (char *) malloc (filename_len + 4 + 1);
96
97 if (result != NULL)
98 {
99 if (sizeof (EXEEXT) > sizeof (""))
100 {
101 /* EXEEXT handling. */
102 const size_t exeext_len = sizeof (EXEEXT) - sizeof ("");
103 static const char exeext[] = EXEEXT;
104 if (filename_len > exeext_len)
105 {
106 /* Compare using an inlined copy of c_strncasecmp(), because
107 the filenames may have undergone a case conversion since
108 they were packaged. In other words, EXEEXT may be ".exe"
109 on one system and ".EXE" on another. */
110 const char *s1 = filename + filename_len - exeext_len;
111 const char *s2 = exeext;
112 for (; *s1 != '\0'; s1++, s2++)
113 {
114 unsigned char c1 = *s1;
115 unsigned char c2 = *s2;
116 if (c_tolower (c1) != c_tolower (c2))
117 goto simple_append;
118 }
119 /* Insert ".bin" before EXEEXT or its equivalent. */
120 memcpy (result, filename, filename_len - exeext_len);
121 memcpy (result + filename_len - exeext_len, ".bin", 4);
122 memcpy (result + filename_len - exeext_len + 4,
123 filename + filename_len - exeext_len,
124 exeext_len + 1);
125 return result;
126 }
127 }
128 simple_append:
129 /* Simply append ".bin". */
130 memcpy (result, filename, filename_len);
131 memcpy (result + filename_len, ".bin", 4 + 1);
132 return result;
133 }
134 else
135 {
136 fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
137 exit (1);
138 }
139 }
140
141 /* List of directories that contain the libraries. */
142 static const char *libdirs[] = { LIBDIRS NULL };
143 /* Verify that at least one directory is given. */
144 static_assert (sizeof (libdirs) / sizeof (libdirs[0]) > 1);
145
146 /* Relocate the list of directories that contain the libraries. */
147 static void
148 relocate_libdirs ()
149 {
150 size_t i;
151
152 for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
153 libdirs[i] = relocate (libdirs[i]);
154 }
155
156 /* Activate the list of directories in the LIBPATHVAR. */
157 static void
158 activate_libdirs ()
159 {
160 const char *old_value;
161 size_t total;
162 size_t i;
163 char *value;
164 char *p;
165
166 old_value = getenv (LIBPATHVAR);
167 if (old_value == NULL)
168 old_value = "";
169
170 total = 0;
171 for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
172 total += strlen (libdirs[i]) + 1;
173 total += strlen (old_value) + 1;
174
175 value = (char *) malloc (total);
176 if (value == NULL)
177 {
178 fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
179 exit (1);
180 }
181 p = value;
182 for (i = 0; i < sizeof (libdirs) / sizeof (libdirs[0]) - 1; i++)
183 {
184 size_t len = strlen (libdirs[i]);
185 memcpy (p, libdirs[i], len);
186 p += len;
187 *p++ = ':';
188 }
189 if (old_value[0] != '\0')
190 strcpy (p, old_value);
191 else
192 p[-1] = '\0';
193
194 if (setenv (LIBPATHVAR, value, 1) < 0)
195 {
196 fprintf (stderr, "%s: %s\n", program_name, "memory exhausted");
197 exit (1);
198 }
199 }
200
201 int
202 main (int argc, char *argv[])
203 {
204 char *full_program_name;
205
206 /* Set the program name and perform preparations for
207 get_full_program_name() and relocate(). */
208 set_program_name_and_installdir (argv[0], INSTALLPREFIX, INSTALLDIR);
209
210 /* Get the full program path. (Important if accessed through a symlink.) */
211 full_program_name = get_full_program_name ();
212 if (full_program_name == NULL)
213 full_program_name = argv[0];
214
215 /* Invoke the real program, with suffix ".bin". */
216 argv[0] = add_dotbin (full_program_name);
217 relocate_libdirs ();
218 activate_libdirs ();
219 execv (argv[0], argv);
220 fprintf (stderr, "%s: could not execute %s: %s\n",
221 program_name, argv[0], strerror (errno));
222 exit (127);
223 }