1*86d7f5d3SJohn Marino /* Return the canonical absolute name of a given file.
2*86d7f5d3SJohn Marino Copyright (C) 1996-2005 Free Software Foundation, Inc.
3*86d7f5d3SJohn Marino
4*86d7f5d3SJohn Marino This program is free software; you can redistribute it and/or modify
5*86d7f5d3SJohn Marino it under the terms of the GNU General Public License as published by
6*86d7f5d3SJohn Marino the Free Software Foundation; either version 2, or (at your option)
7*86d7f5d3SJohn Marino any later version.
8*86d7f5d3SJohn Marino
9*86d7f5d3SJohn Marino This program is distributed in the hope that it will be useful,
10*86d7f5d3SJohn Marino but WITHOUT ANY WARRANTY; without even the implied warranty of
11*86d7f5d3SJohn Marino MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12*86d7f5d3SJohn Marino GNU General Public License for more details.
13*86d7f5d3SJohn Marino
14*86d7f5d3SJohn Marino You should have received a copy of the GNU General Public License
15*86d7f5d3SJohn Marino along with this program; see the file COPYING.
16*86d7f5d3SJohn Marino If not, write to the Free Software Foundation,
17*86d7f5d3SJohn Marino 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18*86d7f5d3SJohn Marino
19*86d7f5d3SJohn Marino #ifdef HAVE_CONFIG_H
20*86d7f5d3SJohn Marino # include <config.h>
21*86d7f5d3SJohn Marino #endif
22*86d7f5d3SJohn Marino
23*86d7f5d3SJohn Marino #include "canonicalize.h"
24*86d7f5d3SJohn Marino
25*86d7f5d3SJohn Marino #ifdef STDC_HEADERS
26*86d7f5d3SJohn Marino # include <stdlib.h>
27*86d7f5d3SJohn Marino #else
28*86d7f5d3SJohn Marino void free ();
29*86d7f5d3SJohn Marino #endif
30*86d7f5d3SJohn Marino
31*86d7f5d3SJohn Marino #if defined STDC_HEADERS || defined HAVE_STRING_H
32*86d7f5d3SJohn Marino # include <string.h>
33*86d7f5d3SJohn Marino #else
34*86d7f5d3SJohn Marino # include <strings.h>
35*86d7f5d3SJohn Marino #endif
36*86d7f5d3SJohn Marino
37*86d7f5d3SJohn Marino #if HAVE_SYS_PARAM_H
38*86d7f5d3SJohn Marino # include <sys/param.h>
39*86d7f5d3SJohn Marino #endif
40*86d7f5d3SJohn Marino
41*86d7f5d3SJohn Marino #include <sys/stat.h>
42*86d7f5d3SJohn Marino
43*86d7f5d3SJohn Marino #if HAVE_UNISTD_H
44*86d7f5d3SJohn Marino # include <unistd.h>
45*86d7f5d3SJohn Marino #endif
46*86d7f5d3SJohn Marino
47*86d7f5d3SJohn Marino #include <errno.h>
48*86d7f5d3SJohn Marino #include <stddef.h>
49*86d7f5d3SJohn Marino
50*86d7f5d3SJohn Marino #include "cycle-check.h"
51*86d7f5d3SJohn Marino #include "filenamecat.h"
52*86d7f5d3SJohn Marino #include "stat-macros.h"
53*86d7f5d3SJohn Marino #include "xalloc.h"
54*86d7f5d3SJohn Marino #include "xgetcwd.h"
55*86d7f5d3SJohn Marino
56*86d7f5d3SJohn Marino #ifndef __set_errno
57*86d7f5d3SJohn Marino # define __set_errno(Val) errno = (Val)
58*86d7f5d3SJohn Marino #endif
59*86d7f5d3SJohn Marino
60*86d7f5d3SJohn Marino #include "pathmax.h"
61*86d7f5d3SJohn Marino #include "xreadlink.h"
62*86d7f5d3SJohn Marino
63*86d7f5d3SJohn Marino #if !HAVE_CANONICALIZE_FILE_NAME
64*86d7f5d3SJohn Marino /* Return the canonical absolute name of file NAME. A canonical name
65*86d7f5d3SJohn Marino does not contain any `.', `..' components nor any repeated file name
66*86d7f5d3SJohn Marino separators ('/') or symlinks. All components must exist.
67*86d7f5d3SJohn Marino The result is malloc'd. */
68*86d7f5d3SJohn Marino
69*86d7f5d3SJohn Marino char *
canonicalize_file_name(const char * name)70*86d7f5d3SJohn Marino canonicalize_file_name (const char *name)
71*86d7f5d3SJohn Marino {
72*86d7f5d3SJohn Marino # if HAVE_RESOLVEPATH
73*86d7f5d3SJohn Marino
74*86d7f5d3SJohn Marino char *resolved, *extra_buf = NULL;
75*86d7f5d3SJohn Marino size_t resolved_size;
76*86d7f5d3SJohn Marino ssize_t resolved_len;
77*86d7f5d3SJohn Marino
78*86d7f5d3SJohn Marino if (name == NULL)
79*86d7f5d3SJohn Marino {
80*86d7f5d3SJohn Marino __set_errno (EINVAL);
81*86d7f5d3SJohn Marino return NULL;
82*86d7f5d3SJohn Marino }
83*86d7f5d3SJohn Marino
84*86d7f5d3SJohn Marino if (name[0] == '\0')
85*86d7f5d3SJohn Marino {
86*86d7f5d3SJohn Marino __set_errno (ENOENT);
87*86d7f5d3SJohn Marino return NULL;
88*86d7f5d3SJohn Marino }
89*86d7f5d3SJohn Marino
90*86d7f5d3SJohn Marino /* All known hosts with resolvepath (e.g. Solaris 7) don't turn
91*86d7f5d3SJohn Marino relative names into absolute ones, so prepend the working
92*86d7f5d3SJohn Marino directory if the file name is not absolute. */
93*86d7f5d3SJohn Marino if (name[0] != '/')
94*86d7f5d3SJohn Marino {
95*86d7f5d3SJohn Marino char *wd;
96*86d7f5d3SJohn Marino
97*86d7f5d3SJohn Marino if (!(wd = xgetcwd ()))
98*86d7f5d3SJohn Marino return NULL;
99*86d7f5d3SJohn Marino
100*86d7f5d3SJohn Marino extra_buf = file_name_concat (wd, name, NULL);
101*86d7f5d3SJohn Marino name = extra_buf;
102*86d7f5d3SJohn Marino free (wd);
103*86d7f5d3SJohn Marino }
104*86d7f5d3SJohn Marino
105*86d7f5d3SJohn Marino resolved_size = strlen (name);
106*86d7f5d3SJohn Marino while (1)
107*86d7f5d3SJohn Marino {
108*86d7f5d3SJohn Marino resolved_size = 2 * resolved_size + 1;
109*86d7f5d3SJohn Marino resolved = xmalloc (resolved_size);
110*86d7f5d3SJohn Marino resolved_len = resolvepath (name, resolved, resolved_size);
111*86d7f5d3SJohn Marino if (resolved_len < 0)
112*86d7f5d3SJohn Marino {
113*86d7f5d3SJohn Marino free (resolved);
114*86d7f5d3SJohn Marino free (extra_buf);
115*86d7f5d3SJohn Marino return NULL;
116*86d7f5d3SJohn Marino }
117*86d7f5d3SJohn Marino if (resolved_len < resolved_size)
118*86d7f5d3SJohn Marino break;
119*86d7f5d3SJohn Marino free (resolved);
120*86d7f5d3SJohn Marino }
121*86d7f5d3SJohn Marino
122*86d7f5d3SJohn Marino free (extra_buf);
123*86d7f5d3SJohn Marino
124*86d7f5d3SJohn Marino /* NUL-terminate the resulting name. */
125*86d7f5d3SJohn Marino resolved[resolved_len] = '\0';
126*86d7f5d3SJohn Marino
127*86d7f5d3SJohn Marino return resolved;
128*86d7f5d3SJohn Marino
129*86d7f5d3SJohn Marino # else
130*86d7f5d3SJohn Marino
131*86d7f5d3SJohn Marino return canonicalize_filename_mode (name, CAN_EXISTING);
132*86d7f5d3SJohn Marino
133*86d7f5d3SJohn Marino # endif /* !HAVE_RESOLVEPATH */
134*86d7f5d3SJohn Marino }
135*86d7f5d3SJohn Marino #endif /* !HAVE_CANONICALIZE_FILE_NAME */
136*86d7f5d3SJohn Marino
137*86d7f5d3SJohn Marino /* Return the canonical absolute name of file NAME. A canonical name
138*86d7f5d3SJohn Marino does not contain any `.', `..' components nor any repeated file name
139*86d7f5d3SJohn Marino separators ('/') or symlinks. Whether components must exist
140*86d7f5d3SJohn Marino or not depends on canonicalize mode. The result is malloc'd. */
141*86d7f5d3SJohn Marino
142*86d7f5d3SJohn Marino char *
canonicalize_filename_mode(const char * name,canonicalize_mode_t can_mode)143*86d7f5d3SJohn Marino canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode)
144*86d7f5d3SJohn Marino {
145*86d7f5d3SJohn Marino char *rname, *dest, *extra_buf = NULL;
146*86d7f5d3SJohn Marino char const *start;
147*86d7f5d3SJohn Marino char const *end;
148*86d7f5d3SJohn Marino char const *rname_limit;
149*86d7f5d3SJohn Marino size_t extra_len = 0;
150*86d7f5d3SJohn Marino struct cycle_check_state cycle_state;
151*86d7f5d3SJohn Marino
152*86d7f5d3SJohn Marino if (name == NULL)
153*86d7f5d3SJohn Marino {
154*86d7f5d3SJohn Marino __set_errno (EINVAL);
155*86d7f5d3SJohn Marino return NULL;
156*86d7f5d3SJohn Marino }
157*86d7f5d3SJohn Marino
158*86d7f5d3SJohn Marino if (name[0] == '\0')
159*86d7f5d3SJohn Marino {
160*86d7f5d3SJohn Marino __set_errno (ENOENT);
161*86d7f5d3SJohn Marino return NULL;
162*86d7f5d3SJohn Marino }
163*86d7f5d3SJohn Marino
164*86d7f5d3SJohn Marino if (name[0] != '/')
165*86d7f5d3SJohn Marino {
166*86d7f5d3SJohn Marino rname = xgetcwd ();
167*86d7f5d3SJohn Marino if (!rname)
168*86d7f5d3SJohn Marino return NULL;
169*86d7f5d3SJohn Marino dest = strchr (rname, '\0');
170*86d7f5d3SJohn Marino if (dest - rname < PATH_MAX)
171*86d7f5d3SJohn Marino {
172*86d7f5d3SJohn Marino char *p = xrealloc (rname, PATH_MAX);
173*86d7f5d3SJohn Marino dest = p + (dest - rname);
174*86d7f5d3SJohn Marino rname = p;
175*86d7f5d3SJohn Marino rname_limit = rname + PATH_MAX;
176*86d7f5d3SJohn Marino }
177*86d7f5d3SJohn Marino else
178*86d7f5d3SJohn Marino {
179*86d7f5d3SJohn Marino rname_limit = dest;
180*86d7f5d3SJohn Marino }
181*86d7f5d3SJohn Marino }
182*86d7f5d3SJohn Marino else
183*86d7f5d3SJohn Marino {
184*86d7f5d3SJohn Marino rname = xmalloc (PATH_MAX);
185*86d7f5d3SJohn Marino rname_limit = rname + PATH_MAX;
186*86d7f5d3SJohn Marino rname[0] = '/';
187*86d7f5d3SJohn Marino dest = rname + 1;
188*86d7f5d3SJohn Marino }
189*86d7f5d3SJohn Marino
190*86d7f5d3SJohn Marino cycle_check_init (&cycle_state);
191*86d7f5d3SJohn Marino for (start = end = name; *start; start = end)
192*86d7f5d3SJohn Marino {
193*86d7f5d3SJohn Marino /* Skip sequence of multiple file name separators. */
194*86d7f5d3SJohn Marino while (*start == '/')
195*86d7f5d3SJohn Marino ++start;
196*86d7f5d3SJohn Marino
197*86d7f5d3SJohn Marino /* Find end of component. */
198*86d7f5d3SJohn Marino for (end = start; *end && *end != '/'; ++end)
199*86d7f5d3SJohn Marino /* Nothing. */;
200*86d7f5d3SJohn Marino
201*86d7f5d3SJohn Marino if (end - start == 0)
202*86d7f5d3SJohn Marino break;
203*86d7f5d3SJohn Marino else if (end - start == 1 && start[0] == '.')
204*86d7f5d3SJohn Marino /* nothing */;
205*86d7f5d3SJohn Marino else if (end - start == 2 && start[0] == '.' && start[1] == '.')
206*86d7f5d3SJohn Marino {
207*86d7f5d3SJohn Marino /* Back up to previous component, ignore if at root already. */
208*86d7f5d3SJohn Marino if (dest > rname + 1)
209*86d7f5d3SJohn Marino while ((--dest)[-1] != '/');
210*86d7f5d3SJohn Marino }
211*86d7f5d3SJohn Marino else
212*86d7f5d3SJohn Marino {
213*86d7f5d3SJohn Marino struct stat st;
214*86d7f5d3SJohn Marino
215*86d7f5d3SJohn Marino if (dest[-1] != '/')
216*86d7f5d3SJohn Marino *dest++ = '/';
217*86d7f5d3SJohn Marino
218*86d7f5d3SJohn Marino if (dest + (end - start) >= rname_limit)
219*86d7f5d3SJohn Marino {
220*86d7f5d3SJohn Marino ptrdiff_t dest_offset = dest - rname;
221*86d7f5d3SJohn Marino size_t new_size = rname_limit - rname;
222*86d7f5d3SJohn Marino
223*86d7f5d3SJohn Marino if (end - start + 1 > PATH_MAX)
224*86d7f5d3SJohn Marino new_size += end - start + 1;
225*86d7f5d3SJohn Marino else
226*86d7f5d3SJohn Marino new_size += PATH_MAX;
227*86d7f5d3SJohn Marino rname = xrealloc (rname, new_size);
228*86d7f5d3SJohn Marino rname_limit = rname + new_size;
229*86d7f5d3SJohn Marino
230*86d7f5d3SJohn Marino dest = rname + dest_offset;
231*86d7f5d3SJohn Marino }
232*86d7f5d3SJohn Marino
233*86d7f5d3SJohn Marino dest = memcpy (dest, start, end - start);
234*86d7f5d3SJohn Marino dest += end - start;
235*86d7f5d3SJohn Marino *dest = '\0';
236*86d7f5d3SJohn Marino
237*86d7f5d3SJohn Marino if (lstat (rname, &st) != 0)
238*86d7f5d3SJohn Marino {
239*86d7f5d3SJohn Marino if (can_mode == CAN_EXISTING)
240*86d7f5d3SJohn Marino goto error;
241*86d7f5d3SJohn Marino if (can_mode == CAN_ALL_BUT_LAST && *end)
242*86d7f5d3SJohn Marino goto error;
243*86d7f5d3SJohn Marino st.st_mode = 0;
244*86d7f5d3SJohn Marino }
245*86d7f5d3SJohn Marino
246*86d7f5d3SJohn Marino if (S_ISLNK (st.st_mode))
247*86d7f5d3SJohn Marino {
248*86d7f5d3SJohn Marino char *buf;
249*86d7f5d3SJohn Marino size_t n, len;
250*86d7f5d3SJohn Marino
251*86d7f5d3SJohn Marino if (cycle_check (&cycle_state, &st))
252*86d7f5d3SJohn Marino {
253*86d7f5d3SJohn Marino __set_errno (ELOOP);
254*86d7f5d3SJohn Marino if (can_mode == CAN_MISSING)
255*86d7f5d3SJohn Marino continue;
256*86d7f5d3SJohn Marino else
257*86d7f5d3SJohn Marino goto error;
258*86d7f5d3SJohn Marino }
259*86d7f5d3SJohn Marino
260*86d7f5d3SJohn Marino buf = xreadlink (rname, st.st_size);
261*86d7f5d3SJohn Marino if (!buf)
262*86d7f5d3SJohn Marino {
263*86d7f5d3SJohn Marino if (can_mode == CAN_MISSING)
264*86d7f5d3SJohn Marino continue;
265*86d7f5d3SJohn Marino else
266*86d7f5d3SJohn Marino goto error;
267*86d7f5d3SJohn Marino }
268*86d7f5d3SJohn Marino
269*86d7f5d3SJohn Marino n = strlen (buf);
270*86d7f5d3SJohn Marino len = strlen (end);
271*86d7f5d3SJohn Marino
272*86d7f5d3SJohn Marino if (!extra_len)
273*86d7f5d3SJohn Marino {
274*86d7f5d3SJohn Marino extra_len =
275*86d7f5d3SJohn Marino ((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX;
276*86d7f5d3SJohn Marino extra_buf = xmalloc (extra_len);
277*86d7f5d3SJohn Marino }
278*86d7f5d3SJohn Marino else if ((n + len + 1) > extra_len)
279*86d7f5d3SJohn Marino {
280*86d7f5d3SJohn Marino extra_len = n + len + 1;
281*86d7f5d3SJohn Marino extra_buf = xrealloc (extra_buf, extra_len);
282*86d7f5d3SJohn Marino }
283*86d7f5d3SJohn Marino
284*86d7f5d3SJohn Marino /* Careful here, end may be a pointer into extra_buf... */
285*86d7f5d3SJohn Marino memmove (&extra_buf[n], end, len + 1);
286*86d7f5d3SJohn Marino name = end = memcpy (extra_buf, buf, n);
287*86d7f5d3SJohn Marino
288*86d7f5d3SJohn Marino if (buf[0] == '/')
289*86d7f5d3SJohn Marino dest = rname + 1; /* It's an absolute symlink */
290*86d7f5d3SJohn Marino else
291*86d7f5d3SJohn Marino /* Back up to previous component, ignore if at root already: */
292*86d7f5d3SJohn Marino if (dest > rname + 1)
293*86d7f5d3SJohn Marino while ((--dest)[-1] != '/');
294*86d7f5d3SJohn Marino
295*86d7f5d3SJohn Marino free (buf);
296*86d7f5d3SJohn Marino }
297*86d7f5d3SJohn Marino else
298*86d7f5d3SJohn Marino {
299*86d7f5d3SJohn Marino if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING))
300*86d7f5d3SJohn Marino {
301*86d7f5d3SJohn Marino errno = ENOTDIR;
302*86d7f5d3SJohn Marino goto error;
303*86d7f5d3SJohn Marino }
304*86d7f5d3SJohn Marino }
305*86d7f5d3SJohn Marino }
306*86d7f5d3SJohn Marino }
307*86d7f5d3SJohn Marino if (dest > rname + 1 && dest[-1] == '/')
308*86d7f5d3SJohn Marino --dest;
309*86d7f5d3SJohn Marino *dest = '\0';
310*86d7f5d3SJohn Marino
311*86d7f5d3SJohn Marino free (extra_buf);
312*86d7f5d3SJohn Marino return rname;
313*86d7f5d3SJohn Marino
314*86d7f5d3SJohn Marino error:
315*86d7f5d3SJohn Marino free (extra_buf);
316*86d7f5d3SJohn Marino free (rname);
317*86d7f5d3SJohn Marino return NULL;
318*86d7f5d3SJohn Marino }
319