1: /* Provide relocatable packages.
2: Copyright (C) 2003-2006, 2008-2011 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: #define _GL_USE_STDLIB_ALLOC 1
29: #include <config.h>
30:
31: /* Specification. */
32: #include "relocatable.h"
33:
34: #if ENABLE_RELOCATABLE
35:
36: #include <stddef.h>
37: #include <stdio.h>
38: #include <stdlib.h>
39: #include <string.h>
40:
41: #ifdef NO_XMALLOC
42: # define xmalloc malloc
43: #else
44: # include "xalloc.h"
45: #endif
46:
47: #if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
48: # define WIN32_LEAN_AND_MEAN
49: # include <windows.h>
50: #endif
51:
52: #if DEPENDS_ON_LIBCHARSET
53: # include <libcharset.h>
54: #endif
55: #if DEPENDS_ON_LIBICONV && HAVE_ICONV
56: # include <iconv.h>
57: #endif
58: #if DEPENDS_ON_LIBINTL && ENABLE_NLS
59: # include <libintl.h>
60: #endif
61:
62: /* Faked cheap 'bool'. */
63: #undef bool
64: #undef false
65: #undef true
66: #define bool int
67: #define false 0
68: #define true 1
69:
70: /* Pathname support.
71: ISSLASH(C) tests whether C is a directory separator character.
72: IS_PATH_WITH_DIR(P) tests whether P contains a directory specification.
73: */
74: #if ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __EMX__ || defined __DJGPP__
75: /* Win32, OS/2, DOS */
76: # define ISSLASH(C) ((C) == '/' || (C) == '\\')
77: # define HAS_DEVICE(P) \
78: ((((P)[0] >= 'A' && (P)[0] <= 'Z') || ((P)[0] >= 'a' && (P)[0] <= 'z')) \
79: && (P)[1] == ':')
80: # define IS_PATH_WITH_DIR(P) \
81: (strchr (P, '/') != NULL || strchr (P, '\\') != NULL || HAS_DEVICE (P))
82: # define FILE_SYSTEM_PREFIX_LEN(P) (HAS_DEVICE (P) ? 2 : 0)
83: #else
84: /* Unix */
85: # define ISSLASH(C) ((C) == '/')
86: # define IS_PATH_WITH_DIR(P) (strchr (P, '/') != NULL)
87: # define FILE_SYSTEM_PREFIX_LEN(P) 0
88: #endif
89:
90: /* Original installation prefix. */
91: static char *orig_prefix;
92: static size_t orig_prefix_len;
93: /* Current installation prefix. */
94: static char *curr_prefix;
95: static size_t curr_prefix_len;
96: /* These prefixes do not end in a slash. Anything that will be concatenated
97: to them must start with a slash. */
98:
99: /* Sets the original and the current installation prefix of this module.
100: Relocation simply replaces a pathname starting with the original prefix
101: by the corresponding pathname with the current prefix instead. Both
102: prefixes should be directory names without trailing slash (i.e. use ""
103: instead of "/"). */
104: static void
105: set_this_relocation_prefix (const char *orig_prefix_arg,
106: const char *curr_prefix_arg)
107: {
108: if (orig_prefix_arg != NULL && curr_prefix_arg != NULL
109: /* Optimization: if orig_prefix and curr_prefix are equal, the
110: relocation is a nop. */
111: && strcmp (orig_prefix_arg, curr_prefix_arg) != 0)
112: {
113: /* Duplicate the argument strings. */
114: char *memory;
115:
116: orig_prefix_len = strlen (orig_prefix_arg);
117: curr_prefix_len = strlen (curr_prefix_arg);
118: memory = (char *) xmalloc (orig_prefix_len + 1 + curr_prefix_len + 1);
119: #ifdef NO_XMALLOC
120: if (memory != NULL)
121: #endif
122: {
123: memcpy (memory, orig_prefix_arg, orig_prefix_len + 1);
124: orig_prefix = memory;
125: memory += orig_prefix_len + 1;
126: memcpy (memory, curr_prefix_arg, curr_prefix_len + 1);
127: curr_prefix = memory;
128: return;
129: }
130: }
131: orig_prefix = NULL;
132: curr_prefix = NULL;
133: /* Don't worry about wasted memory here - this function is usually only
134: called once. */
135: }
136:
137: /* Sets the original and the current installation prefix of the package.
138: Relocation simply replaces a pathname starting with the original prefix
139: by the corresponding pathname with the current prefix instead. Both
140: prefixes should be directory names without trailing slash (i.e. use ""
141: instead of "/"). */
142: void
143: set_relocation_prefix (const char *orig_prefix_arg, const char *curr_prefix_arg)
144: {
145: set_this_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
146:
147: /* Now notify all dependent libraries. */
148: #if DEPENDS_ON_LIBCHARSET
149: libcharset_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
150: #endif
151: #if DEPENDS_ON_LIBICONV && HAVE_ICONV && _LIBICONV_VERSION >= 0x0109
152: libiconv_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
153: #endif
154: #if DEPENDS_ON_LIBINTL && ENABLE_NLS && defined libintl_set_relocation_prefix
155: libintl_set_relocation_prefix (orig_prefix_arg, curr_prefix_arg);
156: #endif
157: }
158:
159: #if !defined IN_LIBRARY || (defined PIC && defined INSTALLDIR)
160:
161: /* Convenience function:
162: Computes the current installation prefix, based on the original
163: installation prefix, the original installation directory of a particular
164: file, and the current pathname of this file.
165: Returns it, freshly allocated. Returns NULL upon failure. */
166: #ifdef IN_LIBRARY
167: #define compute_curr_prefix local_compute_curr_prefix
168: static
169: #endif
170: char *
171: compute_curr_prefix (const char *orig_installprefix,
172: const char *orig_installdir,
173: const char *curr_pathname)
174: {
175: char *curr_installdir;
176: const char *rel_installdir;
177:
178: if (curr_pathname == NULL)
179: return NULL;
180:
181: /* Determine the relative installation directory, relative to the prefix.
182: This is simply the difference between orig_installprefix and
183: orig_installdir. */
184: if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix))
185: != 0)
186: /* Shouldn't happen - nothing should be installed outside $(prefix). */
187: return NULL;
188: rel_installdir = orig_installdir + strlen (orig_installprefix);
189:
190: /* Determine the current installation directory. */
191: {
192: const char *p_base = curr_pathname + FILE_SYSTEM_PREFIX_LEN (curr_pathname);
193: const char *p = curr_pathname + strlen (curr_pathname);
194: char *q;
195:
196: while (p > p_base)
197: {
198: p--;
199: if (ISSLASH (*p))
200: break;
201: }
202:
203: q = (char *) xmalloc (p - curr_pathname + 1);
204: #ifdef NO_XMALLOC
205: if (q == NULL)
206: return NULL;
207: #endif
208: memcpy (q, curr_pathname, p - curr_pathname);
209: q[p - curr_pathname] = '\0';
210: curr_installdir = q;
211: }
212:
213: /* Compute the current installation prefix by removing the trailing
214: rel_installdir from it. */
215: {
216: const char *rp = rel_installdir + strlen (rel_installdir);
217: const char *cp = curr_installdir + strlen (curr_installdir);
218: const char *cp_base =
219: curr_installdir + FILE_SYSTEM_PREFIX_LEN (curr_installdir);
220:
221: while (rp > rel_installdir && cp > cp_base)
222: {
223: bool same = false;
224: const char *rpi = rp;
225: const char *cpi = cp;
226:
227: while (rpi > rel_installdir && cpi > cp_base)
228: {
229: rpi--;
230: cpi--;
231: if (ISSLASH (*rpi) || ISSLASH (*cpi))
232: {
233: if (ISSLASH (*rpi) && ISSLASH (*cpi))
234: same = true;
235: break;
236: }
237: /* Do case-insensitive comparison if the file system is always or
238: often case-insensitive. It's better to accept the comparison
239: if the difference is only in case, rather than to fail. */
240: #if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
241: /* Win32, Cygwin, OS/2, DOS - case insignificant file system */
242: if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi)
243: != (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi))
244: break;
245: #else
246: if (*rpi != *cpi)
247: break;
248: #endif
249: }
250: if (!same)
251: break;
252: /* The last pathname component was the same. opi and cpi now point
253: to the slash before it. */
254: rp = rpi;
255: cp = cpi;
256: }
257:
258: if (rp > rel_installdir)
259: {
260: /* Unexpected: The curr_installdir does not end with rel_installdir. */
261: free (curr_installdir);
262: return NULL;
263: }
264:
265: {
266: size_t curr_prefix_len = cp - curr_installdir;
267: char *curr_prefix;
268:
269: curr_prefix = (char *) xmalloc (curr_prefix_len + 1);
270: #ifdef NO_XMALLOC
271: if (curr_prefix == NULL)
272: {
273: free (curr_installdir);
274: return NULL;
275: }
276: #endif
277: memcpy (curr_prefix, curr_installdir, curr_prefix_len);
278: curr_prefix[curr_prefix_len] = '\0';
279:
280: free (curr_installdir);
281:
282: return curr_prefix;
283: }
284: }
285: }
286:
287: #endif /* !IN_LIBRARY || PIC */
288:
289: #if defined PIC && defined INSTALLDIR
290:
291: /* Full pathname of shared library, or NULL. */
292: static char *shared_library_fullname;
293:
294: #if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
295: /* Native Win32 only.
296: On Cygwin, it is better to use the Cygwin provided /proc interface, than
297: to use native Win32 API and cygwin_conv_to_posix_path, because it supports
298: longer file names
299: (see <http://cygwin.com/ml/cygwin/2011-01/msg00410.html>). */
300:
301: /* Determine the full pathname of the shared library when it is loaded. */
302:
303: BOOL WINAPI
304: DllMain (HINSTANCE module_handle, DWORD event, LPVOID reserved)
305: {
306: (void) reserved;
307:
308: if (event == DLL_PROCESS_ATTACH)
309: {
310: /* The DLL is being loaded into an application's address range. */
311: static char location[MAX_PATH];
312:
313: if (!GetModuleFileName (module_handle, location, sizeof (location)))
314: /* Shouldn't happen. */
315: return FALSE;
316:
317: if (!IS_PATH_WITH_DIR (location))
318: /* Shouldn't happen. */
319: return FALSE;
320:
321: shared_library_fullname = strdup (location);
322: }
323:
324: return TRUE;
325: }
326:
327: #else /* Unix */
328:
329: static void
330: find_shared_library_fullname ()
331: {
332: #if (defined __linux__ && (__GLIBC__ >= 2 || defined __UCLIBC__)) || defined __CYGWIN__
333: /* Linux has /proc/self/maps. glibc 2 and uClibc have the getline()
334: function.
335: Cygwin >= 1.5 has /proc/self/maps and the getline() function too. */
336: FILE *fp;
337:
338: /* Open the current process' maps file. It describes one VMA per line. */
339: fp = fopen ("/proc/self/maps", "r");
340: if (fp)
341: {
342: unsigned long address = (unsigned long) &find_shared_library_fullname;
343: for (;;)
344: {
345: unsigned long start, end;
346: int c;
347:
348: if (fscanf (fp, "%lx-%lx", &start, &end) != 2)
349: break;
350: if (address >= start && address <= end - 1)
351: {
352: /* Found it. Now see if this line contains a filename. */
353: while (c = getc (fp), c != EOF && c != '\n' && c != '/')
354: continue;
355: if (c == '/')
356: {
357: size_t size;
358: int len;
359:
360: ungetc (c, fp);
361: shared_library_fullname = NULL; size = 0;
362: len = getline (&shared_library_fullname, &size, fp);
363: if (len >= 0)
364: {
365: /* Success: filled shared_library_fullname. */
366: if (len > 0 && shared_library_fullname[len - 1] == '\n')
367: shared_library_fullname[len - 1] = '\0';
368: }
369: }
370: break;
371: }
372: while (c = getc (fp), c != EOF && c != '\n')
373: continue;
374: }
375: fclose (fp);
376: }
377: #endif
378: }
379:
380: #endif /* WIN32 / Unix */
381:
382: /* Return the full pathname of the current shared library.
383: Return NULL if unknown.
384: Guaranteed to work only on Linux, Cygwin and Woe32. */
385: static char *
386: get_shared_library_fullname ()
387: {
388: #if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
389: static bool tried_find_shared_library_fullname;
390: if (!tried_find_shared_library_fullname)
391: {
392: find_shared_library_fullname ();
393: tried_find_shared_library_fullname = true;
394: }
395: #endif
396: return shared_library_fullname;
397: }
398:
399: #endif /* PIC */
400:
401: /* Returns the pathname, relocated according to the current installation
402: directory.
403: The returned string is either PATHNAME unmodified or a freshly allocated
404: string that you can free with free() after casting it to 'char *'. */
405: const char *
406: relocate (const char *pathname)
407: {
408: #if defined PIC && defined INSTALLDIR
409: static int initialized;
410:
411: /* Initialization code for a shared library. */
412: if (!initialized)
413: {
414: /* At this point, orig_prefix and curr_prefix likely have already been
415: set through the main program's set_program_name_and_installdir
416: function. This is sufficient in the case that the library has
417: initially been installed in the same orig_prefix. But we can do
418: better, to also cover the cases that 1. it has been installed
419: in a different prefix before being moved to orig_prefix and (later)
420: to curr_prefix, 2. unlike the program, it has not moved away from
421: orig_prefix. */
422: const char *orig_installprefix = INSTALLPREFIX;
423: const char *orig_installdir = INSTALLDIR;
424: char *curr_prefix_better;
425:
426: curr_prefix_better =
427: compute_curr_prefix (orig_installprefix, orig_installdir,
428: get_shared_library_fullname ());
429:
430: set_relocation_prefix (orig_installprefix,
431: curr_prefix_better != NULL
432: ? curr_prefix_better
433: : curr_prefix);
434:
435: if (curr_prefix_better != NULL)
436: free (curr_prefix_better);
437:
438: initialized = 1;
439: }
440: #endif
441:
442: /* Note: It is not necessary to perform case insensitive comparison here,
443: even for DOS-like file systems, because the pathname argument was
444: typically created from the same Makefile variable as orig_prefix came
445: from. */
446: if (orig_prefix != NULL && curr_prefix != NULL
447: && strncmp (pathname, orig_prefix, orig_prefix_len) == 0)
448: {
449: if (pathname[orig_prefix_len] == '\0')
450: {
451: /* pathname equals orig_prefix. */
452: char *result = (char *) xmalloc (strlen (curr_prefix) + 1);
453:
454: #ifdef NO_XMALLOC
455: if (result != NULL)
456: #endif
457: {
458: strcpy (result, curr_prefix);
459: return result;
460: }
461: }
462: else if (ISSLASH (pathname[orig_prefix_len]))
463: {
464: /* pathname starts with orig_prefix. */
465: const char *pathname_tail = &pathname[orig_prefix_len];
466: char *result =
467: (char *) xmalloc (curr_prefix_len + strlen (pathname_tail) + 1);
468:
469: #ifdef NO_XMALLOC
470: if (result != NULL)
471: #endif
472: {
473: memcpy (result, curr_prefix, curr_prefix_len);
474: strcpy (result + curr_prefix_len, pathname_tail);
475: return result;
476: }
477: }
478: }
479: /* Nothing to relocate. */
480: return pathname;
481: }
482:
483: #endif
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