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 "xmalloc.h"
46 #endif
47
48 #if DEPENDS_ON_LIBCHARSET
49 # include <libcharset.h>
50 #endif
51 #if DEPENDS_ON_LIBICONV && HAVE_ICONV
52 # include <iconv.h>
53 #endif
54 #if DEPENDS_ON_LIBINTL && ENABLE_NLS
55 # include <libintl.h>
56 #endif
57
58 /* Faked cheap 'bool'. */
59 #undef bool
60 #undef false
61 #undef true
62 #define bool int
63 #define false 0
64 #define true 1
65
66 /* Pathname support.
67 ISSLASH(C) tests whether C is a directory separator character.
68 IS_PATH_WITH_DIR(P) tests whether P contains a directory specification.
69 */
70 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
71 /* Win32, OS/2, DOS */
72 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
73 # define HAS_DEVICE(P) \
74 ((((P)[0] >= 'A' && (P)[0] <= 'Z') || ((P)[0] >= 'a' && (P)[0] <= 'z')) \
75 && (P)[1] == ':')
76 # define IS_PATH_WITH_DIR(P) \
77 (strchr (P, '/') != NULL || strchr (P, '\\') != NULL || HAS_DEVICE (P))
78 # define FILESYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0)
79 #else
80 /* Unix */
81 # define ISSLASH(C) ((C) == '/')
82 # define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL)
83 # define FILESYSTEM_PREFIX_LEN(P) 0
84 #endif
85
86 /* Original installation prefix. */
87 static char *orig_prefix;
88 static size_t orig_prefix_len;
89 /* Current installation prefix. */
90 static char *curr_prefix;
91 static size_t curr_prefix_len;
92 /* These prefixes do not end in a slash. Anything that will be concatenated
93 to them must start with a slash. */
94
95 /* Sets the original and the current installation prefix of this module.
96 Relocation simply replaces a pathname starting with the original prefix
97 by the corresponding pathname with the current prefix instead. Both
98 prefixes should be directory names without trailing slash (i.e. use ""
99 instead of "/"). */
100 static void
101 set_this_relocation_prefix (const char *orig_prefix_arg,
102 const char *curr_prefix_arg)
103 {
104 if (orig_prefix_arg != NULL && curr_prefix_arg != NULL
105 /* Optimization: if orig_prefix and curr_prefix are equal, the
106 relocation is a nop. */
107 && strcmp (orig_prefix_arg, curr_prefix_arg) != 0)
108 {
109 /* Duplicate the argument strings. */
110 char *memory;
111
112 orig_prefix_len = strlen (orig_prefix_arg);
113 curr_prefix_len = strlen (curr_prefix_arg);
114 memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1);
115 #ifdef NO_XMALLOC
116 if (memory != NULL)
117 #endif
118 {
119 memcpy (memory, orig_prefix_arg, orig_prefix_len + 1);
120 orig_prefix = memory;
121 memory += orig_prefix_len + 1;
122 memcpy (memory, curr_prefix_arg, curr_prefix_len + 1);
123 curr_prefix = memory;
124 return;
125 }
126 }
127 orig_prefix = NULL;
128 curr_prefix = NULL;
129 /* Don't worry about wasted memory here - this function is usually only
130 called once. */
131 }
132
133 /* Sets the original and the current installation prefix of the package.
134 Relocation simply replaces a pathname starting with the original prefix
135 by the corresponding pathname with the current prefix instead. Both
136 prefixes should be directory names without trailing slash (i.e. use ""
137 instead of "/"). */
138 void
139 set_relocation_prefix (const char *orig_prefix_arg, const char *curr_prefix_arg)
140 {
141 set_this_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
142
143 /* Now notify all dependent libraries. */
144 #if DEPENDS_ON_LIBCHARSET
145 libcharset_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
146 #endif
147 #if DEPENDS_ON_LIBICONV && HAVE_ICONV && _LIBICONV_VERSION >= 0x0109
148 libiconv_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
149 #endif
150 #if DEPENDS_ON_LIBINTL && ENABLE_NLS && defined libintl_set_relocation_prefix
151 libintl_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
152 #endif
153 }
154
155 /* Convenience function:
156 Computes the current installation prefix, based on the original
157 installation prefix, the original installation directory of a particular
158 file, and the current pathname of this file. Returns NULL upon failure. */
159 #ifdef IN_LIBRARY
160 #define compute_curr_prefix local_compute_curr_prefix
161 static
162 #endif
163 const char *
164 compute_curr_prefix (const char *orig_installprefix,
165 const char *orig_installdir,
166 const char *curr_pathname)
167 {
168 const char *curr_installdir;
169 const char *rel_installdir;
170
171 if (curr_pathname == NULL)
172 return NULL;
173
174 /* Determine the relative installation directory, relative to the prefix.
175 This is simply the difference between orig_installprefix and
176 orig_installdir. */
177 if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix))
178 != 0)
179 /* Shouldn't happen - nothing should be installed outside $(prefix). */
180 return NULL;
181 rel_installdir = orig_installdir + strlen (orig_installprefix);
182
183 /* Determine the current installation directory. */
184 {
185 const char *p_base = curr_pathname + FILESYSTEM_PREFIX_LEN (curr_pathname);
186 const char *p = curr_pathname + strlen (curr_pathname);
187 char *q;
188
189 while (p > p_base)
190 {
191 p--;
192 if (ISSLASH (*p))
193 break;
194 }
195
196 q = (char *) xmalloc (p - curr_pathname + 1);
197 #ifdef NO_XMALLOC
198 if (q == NULL)
199 return NULL;
200 #endif
201 memcpy (q, curr_pathname, p - curr_pathname);
202 q[p - curr_pathname] = '\0';
203 curr_installdir = q;
204 }
205
206 /* Compute the current installation prefix by removing the trailing
207 rel_installdir from it. */
208 {
209 const char *rp = rel_installdir + strlen (rel_installdir);
210 const char *cp = curr_installdir + strlen (curr_installdir);
211 const char *cp_base =
212 curr_installdir + FILESYSTEM_PREFIX_LEN (curr_installdir);
213
214 while (rp > rel_installdir && cp > cp_base)
215 {
216 bool same = false;
217 const char *rpi = rp;
218 const char *cpi = cp;
219
220 while (rpi > rel_installdir && cpi > cp_base)
221 {
222 rpi--;
223 cpi--;
224 if (ISSLASH (*rpi) || ISSLASH (*cpi))
225 {
226 if (ISSLASH (*rpi) && ISSLASH (*cpi))
227 same = true;
228 break;
229 }
230 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
231 /* Win32, OS/2, DOS - case insignificant filesystem */
232 if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi)
233 != (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi))
234 break;
235 #else
236 if (*rpi != *cpi)
237 break;
238 #endif
239 }
240 if (!same)
241 break;
242 /* The last pathname component was the same. opi and cpi now point
243 to the slash before it. */
244 rp = rpi;
245 cp = cpi;
246 }
247
248 if (rp > rel_installdir)
249 /* Unexpected: The curr_installdir does not end with rel_installdir. */
250 return NULL;
251
252 {
253 size_t curr_prefix_len = cp - curr_installdir;
254 char *curr_prefix;
255
256 curr_prefix = (char *) xmalloc (curr_prefix_len + 1);
257 #ifdef NO_XMALLOC
258 if (curr_prefix == NULL)
259 return NULL;
260 #endif
261 memcpy (curr_prefix, curr_installdir, curr_prefix_len);
262 curr_prefix[curr_prefix_len] = '\0';
263
264 return curr_prefix;
265 }
266 }
267 }
268
269 #if defined PIC && defined INSTALLDIR
270
271 /* Full pathname of shared library, or NULL. */
272 static char *shared_library_fullname;
273
274 #if defined _WIN32 || defined __WIN32__
275
276 /* Determine the full pathname of the shared library when it is loaded. */
277
278 BOOL WINAPI
279 DllMain (HINSTANCE module_handle, DWORD event, LPVOID reserved)
280 {
281 (void) reserved;
282
283 if (event == DLL_PROCESS_ATTACH)
284 {
285 /* The DLL is being loaded into an application's address range. */
286 static char location[MAX_PATH];
287
288 if (!GetModuleFileName (module_handle, location, sizeof (location)))
289 /* Shouldn't happen. */
290 return FALSE;
291
292 if (!IS_PATH_WITH_DIR (location))
293 /* Shouldn't happen. */
294 return FALSE;
295
296 shared_library_fullname = strdup (location);
297 }
298
299 return TRUE;
300 }
301
302 #else /* Unix */
303
304 static void
305 find_shared_library_fullname ()
306 {
307 #ifdef __linux__
308 FILE *fp;
309
310 /* Open the current process' maps file. It describes one VMA per line. */
311 fp = fopen ("/proc/self/maps", "r");
312 if (fp)
313 {
314 unsigned long address = (unsigned long) &find_shared_library_fullname;
315 for (;;)
316 {
317 unsigned long start, end;
318 int c;
319
320 if (fscanf (fp, "%lx-%lx", &start, &end) != 2)
321 break;
322 if (address >= start && address <= end - 1)
323 {
324 /* Found it. Now see if this line contains a filename. */
325 while (c = getc (fp), c != EOF && c != '\n' && c != '/')
326 continue;
327 if (c == '/')
328 {
329 size_t size;
330 int len;
331
332 ungetc (c, fp);
333 shared_library_fullname = NULL; size = 0;
334 len = getline (&shared_library_fullname, &size, fp);
335 if (len >= 0)
336 {
337 /* Success: filled shared_library_fullname. */
338 if (len > 0 && shared_library_fullname[len - 1] == '\n')
339 shared_library_fullname[len - 1] = '\0';
340 }
341 }
342 break;
343 }
344 while (c = getc (fp), c != EOF && c != '\n')
345 continue;
346 }
347 fclose (fp);
348 }
349 #endif
350 }
351
352 #endif /* WIN32 / Unix */
353
354 /* Return the full pathname of the current shared library.
355 Return NULL if unknown.
356 Guaranteed to work only on Linux and Woe32. */
357 static char *
358 get_shared_library_fullname ()
359 {
360 #if !(defined _WIN32 || defined __WIN32__)
361 static bool tried_find_shared_library_fullname;
362 if (!tried_find_shared_library_fullname)
363 {
364 find_shared_library_fullname ();
365 tried_find_shared_library_fullname = true;
366 }
367 #endif
368 return shared_library_fullname;
369 }
370
371 #endif /* PIC */
372
373 /* Returns the pathname, relocated according to the current installation
374 directory. */
375 const char *
376 relocate (const char *pathname)
377 {
378 #if defined PIC && defined INSTALLDIR
379 static int initialized;
380
381 /* Initialization code for a shared library. */
382 if (!initialized)
383 {
384 /* At this point, orig_prefix and curr_prefix likely have already been
385 set through the main program's set_program_name_and_installdir
386 function. This is sufficient in the case that the library has
387 initially been installed in the same orig_prefix. But we can do
388 better, to also cover the cases that 1. it has been installed
389 in a different prefix before being moved to orig_prefix and (later)
390 to curr_prefix, 2. unlike the program, it has not moved away from
391 orig_prefix. */
392 const char *orig_installprefix = INSTALLPREFIX;
393 const char *orig_installdir = INSTALLDIR;
394 const char *curr_prefix_better;
395
396 curr_prefix_better =
397 compute_curr_prefix (orig_installprefix, orig_installdir,
398 get_shared_library_fullname ());
399 if (curr_prefix_better == NULL)
400 curr_prefix_better = curr_prefix;
401
402 set_relocation_prefix (orig_installprefix, curr_prefix_better);
403
404 initialized = 1;
405 }
406 #endif
407
408 /* Note: It is not necessary to perform case insensitive comparison here,
409 even for DOS-like filesystems, because the pathname argument was
410 typically created from the same Makefile variable as orig_prefix came
411 from. */
412 if (orig_prefix != NULL && curr_prefix != NULL
413 && strncmp (pathname, orig_prefix, orig_prefix_len) == 0)
414 {
415 if (pathname[orig_prefix_len] == '\0')
416 /* pathname equals orig_prefix. */
417 return curr_prefix;
418 if (ISSLASH (pathname[orig_prefix_len]))
419 {
420 /* pathname starts with orig_prefix. */
421 const char *pathname_tail = &pathname[orig_prefix_len];
422 char *result =
423 (char *) xmalloc (curr_prefix_len + strlen (pathname_tail) + 1);
424
425 #ifdef NO_XMALLOC
426 if (result != NULL)
427 #endif
428 {
429 memcpy (result, curr_prefix, curr_prefix_len);
430 strcpy (result + curr_prefix_len, pathname_tail);
431 return result;
432 }
433 }
434 }
435 /* Nothing to relocate. */
436 return pathname;
437 }
438
439 #endif