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443172c4 | 1 | /* |
2 | * Copyright (c) 1994 | |
3 | * The Regents of the University of California. All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Jan-Simon Pendry. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
27 | * SUCH DAMAGE. | |
28 | */ | |
29 | ||
30 | #include "includes.h" | |
31 | ||
32 | #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) | |
33 | ||
34 | #if defined(LIBC_SCCS) && !defined(lint) | |
35 | static char *rcsid = "$OpenBSD: realpath..c,v 1.4 1998/05/18 09:55:19 deraadt Exp $"; | |
36 | #endif /* LIBC_SCCS and not lint */ | |
37 | ||
38 | #include <sys/param.h> | |
39 | #include <sys/stat.h> | |
40 | ||
41 | #include <errno.h> | |
42 | #include <fcntl.h> | |
43 | #include <stdlib.h> | |
44 | #include <string.h> | |
45 | #include <unistd.h> | |
46 | ||
47 | /* | |
48 | * S_ISLNK compatibility | |
49 | */ | |
50 | #ifndef S_ISLNK | |
51 | #define S_ISLNK(m) ((m & 0170000) == 0120000) | |
52 | #endif | |
53 | ||
c2207f11 | 54 | /* |
55 | * MAXSYMLINKS | |
56 | */ | |
57 | #ifndef MAXSYMLINKS | |
58 | #define MAXSYMLINKS 5 | |
59 | #endif | |
60 | ||
443172c4 | 61 | /* |
62 | * char *realpath(const char *path, char resolved_path[MAXPATHLEN]); | |
63 | * | |
64 | * Find the real name of path, by removing all ".", ".." and symlink | |
65 | * components. Returns (resolved) on success, or (NULL) on failure, | |
66 | * in which case the path which caused trouble is left in (resolved). | |
67 | */ | |
68 | char * | |
69 | realpath(const char *path, char *resolved) | |
70 | { | |
71 | struct stat sb; | |
72 | int fd, n, rootd, serrno = 0; | |
73 | char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN]; | |
74 | int symlinks = 0; | |
75 | ||
76 | /* Save the starting point. */ | |
77 | getcwd(start,MAXPATHLEN); | |
78 | if ((fd = open(".", O_RDONLY)) < 0) { | |
79 | (void)strcpy(resolved, "."); | |
80 | return (NULL); | |
81 | } | |
82 | close(fd); | |
83 | ||
84 | /* | |
85 | * Find the dirname and basename from the path to be resolved. | |
86 | * Change directory to the dirname component. | |
87 | * lstat the basename part. | |
88 | * if it is a symlink, read in the value and loop. | |
89 | * if it is a directory, then change to that directory. | |
90 | * get the current directory name and append the basename. | |
91 | */ | |
92 | (void)strncpy(resolved, path, MAXPATHLEN - 1); | |
93 | resolved[MAXPATHLEN - 1] = '\0'; | |
94 | loop: | |
95 | q = strrchr(resolved, '/'); | |
96 | if (q != NULL) { | |
97 | p = q + 1; | |
98 | if (q == resolved) | |
99 | q = "/"; | |
100 | else { | |
101 | do { | |
102 | --q; | |
103 | } while (q > resolved && *q == '/'); | |
104 | q[1] = '\0'; | |
105 | q = resolved; | |
106 | } | |
107 | if (chdir(q) < 0) | |
108 | goto err1; | |
109 | } else | |
110 | p = resolved; | |
111 | ||
112 | /* Deal with the last component. */ | |
113 | if (lstat(p, &sb) == 0) { | |
114 | if (S_ISLNK(sb.st_mode)) { | |
115 | if (++symlinks > MAXSYMLINKS) { | |
116 | serrno = ELOOP; | |
117 | goto err1; | |
118 | } | |
119 | n = readlink(p, resolved, MAXPATHLEN-1); | |
120 | if (n < 0) | |
121 | goto err1; | |
122 | resolved[n] = '\0'; | |
123 | goto loop; | |
124 | } | |
125 | if (S_ISDIR(sb.st_mode)) { | |
126 | if (chdir(p) < 0) | |
127 | goto err1; | |
128 | p = ""; | |
129 | } | |
130 | } | |
131 | ||
132 | /* | |
133 | * Save the last component name and get the full pathname of | |
134 | * the current directory. | |
135 | */ | |
136 | (void)strcpy(wbuf, p); | |
137 | if (getcwd(resolved, MAXPATHLEN) == 0) | |
138 | goto err1; | |
139 | ||
140 | /* | |
141 | * Join the two strings together, ensuring that the right thing | |
142 | * happens if the last component is empty, or the dirname is root. | |
143 | */ | |
144 | if (resolved[0] == '/' && resolved[1] == '\0') | |
145 | rootd = 1; | |
146 | else | |
147 | rootd = 0; | |
148 | ||
149 | if (*wbuf) { | |
150 | if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) { | |
151 | serrno = ENAMETOOLONG; | |
152 | goto err1; | |
153 | } | |
154 | if (rootd == 0) | |
155 | (void)strcat(resolved, "/"); | |
156 | (void)strcat(resolved, wbuf); | |
157 | } | |
158 | ||
159 | /* Go back to where we came from. */ | |
160 | if (chdir(start) < 0) { | |
161 | serrno = errno; | |
162 | goto err2; | |
163 | } | |
164 | return (resolved); | |
165 | ||
166 | err1: chdir(start); | |
167 | err2: errno = serrno; | |
168 | return (NULL); | |
169 | } | |
170 | #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */ |