1 /* $NetBSD: relocatable.c,v 1.1.1.1 2016/01/14 00:11:28 christos Exp $ */
2
3 /* Provide relocatable packages.
4 Copyright (C) 2003 Free Software Foundation, Inc.
5 Written by Bruno Haible <bruno@clisp.org>, 2003.
6
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU Library General Public License as published
9 by the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
16
17 You should have received a copy of the GNU Library General Public
18 License along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20 USA. */
21
22
23 /* Tell glibc's <stdio.h> to provide a prototype for getline().
24 This must come before <config.h> because <config.h> may include
25 <features.h>, and once <features.h> has been included, it's too late. */
26 #ifndef _GNU_SOURCE
27 # define _GNU_SOURCE 1
28 #endif
29
30 #ifdef HAVE_CONFIG_H
31 # include "config.h"
32 #endif
33
34 /* Specification. */
35 #include "relocatable.h"
36
37 #if ENABLE_RELOCATABLE
38
39 #include <stddef.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43
44 #ifdef NO_XMALLOC
45 # define xmalloc malloc
46 #else
47 # include "xalloc.h"
48 #endif
49
50 #if defined _WIN32 || defined __WIN32__
51 # define WIN32_LEAN_AND_MEAN
52 # include <windows.h>
53 #endif
54
55 #if DEPENDS_ON_LIBCHARSET
56 # include <libcharset.h>
57 #endif
58 #if DEPENDS_ON_LIBICONV && HAVE_ICONV
59 # include <iconv.h>
60 #endif
61 #if DEPENDS_ON_LIBINTL && ENABLE_NLS
62 # include <libintl.h>
63 #endif
64
65 /* Faked cheap 'bool'. */
66 #undef bool
67 #undef false
68 #undef true
69 #define bool int
70 #define false 0
71 #define true 1
72
73 /* Pathname support.
74 ISSLASH(C) tests whether C is a directory separator character.
75 IS_PATH_WITH_DIR(P) tests whether P contains a directory specification.
76 */
77 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
78 /* Win32, OS/2, DOS */
79 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
80 # define HAS_DEVICE(P) \
81 ((((P)[0] >= 'A' && (P)[0] <= 'Z') || ((P)[0] >= 'a' && (P)[0] <= 'z')) \
82 && (P)[1] == ':')
83 # define IS_PATH_WITH_DIR(P) \
84 (strchr (P, '/') != NULL || strchr (P, '\\') != NULL || HAS_DEVICE (P))
85 # define FILESYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0)
86 #else
87 /* Unix */
88 # define ISSLASH(C) ((C) == '/')
89 # define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL)
90 # define FILESYSTEM_PREFIX_LEN(P) 0
91 #endif
92
93 /* Original installation prefix. */
94 static char *orig_prefix;
95 static size_t orig_prefix_len;
96 /* Current installation prefix. */
97 static char *curr_prefix;
98 static size_t curr_prefix_len;
99 /* These prefixes do not end in a slash. Anything that will be concatenated
100 to them must start with a slash. */
101
102 /* Sets the original and the current installation prefix of this module.
103 Relocation simply replaces a pathname starting with the original prefix
104 by the corresponding pathname with the current prefix instead. Both
105 prefixes should be directory names without trailing slash (i.e. use ""
106 instead of "/"). */
107 static void
set_this_relocation_prefix(const char * orig_prefix_arg,const char * curr_prefix_arg)108 set_this_relocation_prefix (const char *orig_prefix_arg,
109 const char *curr_prefix_arg)
110 {
111 if (orig_prefix_arg != NULL && curr_prefix_arg != NULL
112 /* Optimization: if orig_prefix and curr_prefix are equal, the
113 relocation is a nop. */
114 && strcmp (orig_prefix_arg, curr_prefix_arg) != 0)
115 {
116 /* Duplicate the argument strings. */
117 char *memory;
118
119 orig_prefix_len = strlen (orig_prefix_arg);
120 curr_prefix_len = strlen (curr_prefix_arg);
121 memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1);
122 #ifdef NO_XMALLOC
123 if (memory != NULL)
124 #endif
125 {
126 memcpy (memory, orig_prefix_arg, orig_prefix_len + 1);
127 orig_prefix = memory;
128 memory += orig_prefix_len + 1;
129 memcpy (memory, curr_prefix_arg, curr_prefix_len + 1);
130 curr_prefix = memory;
131 return;
132 }
133 }
134 orig_prefix = NULL;
135 curr_prefix = NULL;
136 /* Don't worry about wasted memory here - this function is usually only
137 called once. */
138 }
139
140 /* Sets the original and the current installation prefix of the package.
141 Relocation simply replaces a pathname starting with the original prefix
142 by the corresponding pathname with the current prefix instead. Both
143 prefixes should be directory names without trailing slash (i.e. use ""
144 instead of "/"). */
145 void
set_relocation_prefix(const char * orig_prefix_arg,const char * curr_prefix_arg)146 set_relocation_prefix (const char *orig_prefix_arg, const char *curr_prefix_arg)
147 {
148 set_this_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
149
150 /* Now notify all dependent libraries. */
151 #if DEPENDS_ON_LIBCHARSET
152 libcharset_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
153 #endif
154 #if DEPENDS_ON_LIBICONV && HAVE_ICONV && _LIBICONV_VERSION >= 0x0109
155 libiconv_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
156 #endif
157 #if DEPENDS_ON_LIBINTL && ENABLE_NLS && defined libintl_set_relocation_prefix
158 libintl_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
159 #endif
160 }
161
162 #if !defined IN_LIBRARY || (defined PIC && defined INSTALLDIR)
163
164 /* Convenience function:
165 Computes the current installation prefix, based on the original
166 installation prefix, the original installation directory of a particular
167 file, and the current pathname of this file. Returns NULL upon failure. */
168 #ifdef IN_LIBRARY
169 #define compute_curr_prefix local_compute_curr_prefix
170 static
171 #endif
172 const char *
compute_curr_prefix(const char * orig_installprefix,const char * orig_installdir,const char * curr_pathname)173 compute_curr_prefix (const char *orig_installprefix,
174 const char *orig_installdir,
175 const char *curr_pathname)
176 {
177 const char *curr_installdir;
178 const char *rel_installdir;
179
180 if (curr_pathname == NULL)
181 return NULL;
182
183 /* Determine the relative installation directory, relative to the prefix.
184 This is simply the difference between orig_installprefix and
185 orig_installdir. */
186 if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix))
187 != 0)
188 /* Shouldn't happen - nothing should be installed outside $(prefix). */
189 return NULL;
190 rel_installdir = orig_installdir + strlen (orig_installprefix);
191
192 /* Determine the current installation directory. */
193 {
194 const char *p_base = curr_pathname + FILESYSTEM_PREFIX_LEN (curr_pathname);
195 const char *p = curr_pathname + strlen (curr_pathname);
196 char *q;
197
198 while (p > p_base)
199 {
200 p--;
201 if (ISSLASH (*p))
202 break;
203 }
204
205 q = (char *) xmalloc (p - curr_pathname + 1);
206 #ifdef NO_XMALLOC
207 if (q == NULL)
208 return NULL;
209 #endif
210 memcpy (q, curr_pathname, p - curr_pathname);
211 q[p - curr_pathname] = '\0';
212 curr_installdir = q;
213 }
214
215 /* Compute the current installation prefix by removing the trailing
216 rel_installdir from it. */
217 {
218 const char *rp = rel_installdir + strlen (rel_installdir);
219 const char *cp = curr_installdir + strlen (curr_installdir);
220 const char *cp_base =
221 curr_installdir + FILESYSTEM_PREFIX_LEN (curr_installdir);
222
223 while (rp > rel_installdir && cp > cp_base)
224 {
225 bool same = false;
226 const char *rpi = rp;
227 const char *cpi = cp;
228
229 while (rpi > rel_installdir && cpi > cp_base)
230 {
231 rpi--;
232 cpi--;
233 if (ISSLASH (*rpi) || ISSLASH (*cpi))
234 {
235 if (ISSLASH (*rpi) && ISSLASH (*cpi))
236 same = true;
237 break;
238 }
239 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
240 /* Win32, OS/2, DOS - case insignificant filesystem */
241 if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi)
242 != (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi))
243 break;
244 #else
245 if (*rpi != *cpi)
246 break;
247 #endif
248 }
249 if (!same)
250 break;
251 /* The last pathname component was the same. opi and cpi now point
252 to the slash before it. */
253 rp = rpi;
254 cp = cpi;
255 }
256
257 if (rp > rel_installdir)
258 /* Unexpected: The curr_installdir does not end with rel_installdir. */
259 return NULL;
260
261 {
262 size_t curr_prefix_len = cp - curr_installdir;
263 char *curr_prefix;
264
265 curr_prefix = (char *) xmalloc (curr_prefix_len + 1);
266 #ifdef NO_XMALLOC
267 if (curr_prefix == NULL)
268 return NULL;
269 #endif
270 memcpy (curr_prefix, curr_installdir, curr_prefix_len);
271 curr_prefix[curr_prefix_len] = '\0';
272
273 return curr_prefix;
274 }
275 }
276 }
277
278 #endif /* !IN_LIBRARY || PIC */
279
280 #if defined PIC && defined INSTALLDIR
281
282 /* Full pathname of shared library, or NULL. */
283 static char *shared_library_fullname;
284
285 #if defined _WIN32 || defined __WIN32__
286
287 /* Determine the full pathname of the shared library when it is loaded. */
288
289 BOOL WINAPI
DllMain(HINSTANCE module_handle,DWORD event,LPVOID reserved)290 DllMain (HINSTANCE module_handle, DWORD event, LPVOID reserved)
291 {
292 (void) reserved;
293
294 if (event == DLL_PROCESS_ATTACH)
295 {
296 /* The DLL is being loaded into an application's address range. */
297 static char location[MAX_PATH];
298
299 if (!GetModuleFileName (module_handle, location, sizeof (location)))
300 /* Shouldn't happen. */
301 return FALSE;
302
303 if (!IS_PATH_WITH_DIR (location))
304 /* Shouldn't happen. */
305 return FALSE;
306
307 shared_library_fullname = strdup (location);
308 }
309
310 return TRUE;
311 }
312
313 #else /* Unix */
314
315 static void
find_shared_library_fullname()316 find_shared_library_fullname ()
317 {
318 #if defined __linux__ && __GLIBC__ >= 2
319 /* Linux has /proc/self/maps. glibc 2 has the getline() function. */
320 FILE *fp;
321
322 /* Open the current process' maps file. It describes one VMA per line. */
323 fp = fopen ("/proc/self/maps", "r");
324 if (fp)
325 {
326 unsigned long address = (unsigned long) &find_shared_library_fullname;
327 for (;;)
328 {
329 unsigned long start, end;
330 int c;
331
332 if (fscanf (fp, "%lx-%lx", &start, &end) != 2)
333 break;
334 if (address >= start && address <= end - 1)
335 {
336 /* Found it. Now see if this line contains a filename. */
337 while (c = getc (fp), c != EOF && c != '\n' && c != '/')
338 continue;
339 if (c == '/')
340 {
341 size_t size;
342 int len;
343
344 ungetc (c, fp);
345 shared_library_fullname = NULL; size = 0;
346 len = getline (&shared_library_fullname, &size, fp);
347 if (len >= 0)
348 {
349 /* Success: filled shared_library_fullname. */
350 if (len > 0 && shared_library_fullname[len - 1] == '\n')
351 shared_library_fullname[len - 1] = '\0';
352 }
353 }
354 break;
355 }
356 while (c = getc (fp), c != EOF && c != '\n')
357 continue;
358 }
359 fclose (fp);
360 }
361 #endif
362 }
363
364 #endif /* WIN32 / Unix */
365
366 /* Return the full pathname of the current shared library.
367 Return NULL if unknown.
368 Guaranteed to work only on Linux and Woe32. */
369 static char *
get_shared_library_fullname()370 get_shared_library_fullname ()
371 {
372 #if !(defined _WIN32 || defined __WIN32__)
373 static bool tried_find_shared_library_fullname;
374 if (!tried_find_shared_library_fullname)
375 {
376 find_shared_library_fullname ();
377 tried_find_shared_library_fullname = true;
378 }
379 #endif
380 return shared_library_fullname;
381 }
382
383 #endif /* PIC */
384
385 /* Returns the pathname, relocated according to the current installation
386 directory. */
387 const char *
relocate(const char * pathname)388 relocate (const char *pathname)
389 {
390 #if defined PIC && defined INSTALLDIR
391 static int initialized;
392
393 /* Initialization code for a shared library. */
394 if (!initialized)
395 {
396 /* At this point, orig_prefix and curr_prefix likely have already been
397 set through the main program's set_program_name_and_installdir
398 function. This is sufficient in the case that the library has
399 initially been installed in the same orig_prefix. But we can do
400 better, to also cover the cases that 1. it has been installed
401 in a different prefix before being moved to orig_prefix and (later)
402 to curr_prefix, 2. unlike the program, it has not moved away from
403 orig_prefix. */
404 const char *orig_installprefix = INSTALLPREFIX;
405 const char *orig_installdir = INSTALLDIR;
406 const char *curr_prefix_better;
407
408 curr_prefix_better =
409 compute_curr_prefix (orig_installprefix, orig_installdir,
410 get_shared_library_fullname ());
411 if (curr_prefix_better == NULL)
412 curr_prefix_better = curr_prefix;
413
414 set_relocation_prefix (orig_installprefix, curr_prefix_better);
415
416 initialized = 1;
417 }
418 #endif
419
420 /* Note: It is not necessary to perform case insensitive comparison here,
421 even for DOS-like filesystems, because the pathname argument was
422 typically created from the same Makefile variable as orig_prefix came
423 from. */
424 if (orig_prefix != NULL && curr_prefix != NULL
425 && strncmp (pathname, orig_prefix, orig_prefix_len) == 0)
426 {
427 if (pathname[orig_prefix_len] == '\0')
428 /* pathname equals orig_prefix. */
429 return curr_prefix;
430 if (ISSLASH (pathname[orig_prefix_len]))
431 {
432 /* pathname starts with orig_prefix. */
433 const char *pathname_tail = &pathname[orig_prefix_len];
434 char *result =
435 (char *) xmalloc (curr_prefix_len + strlen (pathname_tail) + 1);
436
437 #ifdef NO_XMALLOC
438 if (result != NULL)
439 #endif
440 {
441 memcpy (result, curr_prefix, curr_prefix_len);
442 strcpy (result + curr_prefix_len, pathname_tail);
443 return result;
444 }
445 }
446 }
447 /* Nothing to relocate. */
448 return pathname;
449 }
450
451 #endif
452