]>
Commit | Line | Data |
---|---|---|
7dea820a | 1 | /* $OpenBSD: realpath.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */ |
443172c4 | 2 | /* |
1a9ecc62 | 3 | * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru> |
443172c4 | 4 | * |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
1a9ecc62 | 13 | * 3. The names of the authors may not be used to endorse or promote |
14 | * products derived from this software without specific prior written | |
15 | * permission. | |
443172c4 | 16 | * |
1a9ecc62 | 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
443172c4 | 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
1a9ecc62 | 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
443172c4 | 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 | ||
f6d4fb87 | 30 | /* OPENBSD ORIGINAL: lib/libc/stdlib/realpath.c */ |
31 | ||
443172c4 | 32 | #include "includes.h" |
33 | ||
34 | #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) | |
35 | ||
443172c4 | 36 | #include <sys/param.h> |
37 | #include <sys/stat.h> | |
38 | ||
39 | #include <errno.h> | |
443172c4 | 40 | #include <stdlib.h> |
41 | #include <string.h> | |
42 | #include <unistd.h> | |
43 | ||
c2207f11 | 44 | /* |
1a9ecc62 | 45 | * char *realpath(const char *path, char resolved[PATH_MAX]); |
443172c4 | 46 | * |
47 | * Find the real name of path, by removing all ".", ".." and symlink | |
48 | * components. Returns (resolved) on success, or (NULL) on failure, | |
49 | * in which case the path which caused trouble is left in (resolved). | |
50 | */ | |
51 | char * | |
1a9ecc62 | 52 | realpath(const char *path, char resolved[PATH_MAX]) |
443172c4 | 53 | { |
54 | struct stat sb; | |
1a9ecc62 | 55 | char *p, *q, *s; |
56 | size_t left_len, resolved_len; | |
57 | unsigned symlinks; | |
58 | int serrno, slen; | |
59 | char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; | |
60 | ||
61 | serrno = errno; | |
62 | symlinks = 0; | |
63 | if (path[0] == '/') { | |
64 | resolved[0] = '/'; | |
667abcc6 | 65 | resolved[1] = '\0'; |
1a9ecc62 | 66 | if (path[1] == '\0') |
67 | return (resolved); | |
68 | resolved_len = 1; | |
69 | left_len = strlcpy(left, path + 1, sizeof(left)); | |
70 | } else { | |
71 | if (getcwd(resolved, PATH_MAX) == NULL) { | |
72 | strlcpy(resolved, ".", PATH_MAX); | |
73 | return (NULL); | |
74 | } | |
75 | resolved_len = strlen(resolved); | |
76 | left_len = strlcpy(left, path, sizeof(left)); | |
667abcc6 | 77 | } |
1a9ecc62 | 78 | if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) { |
79 | errno = ENAMETOOLONG; | |
443172c4 | 80 | return (NULL); |
81 | } | |
443172c4 | 82 | |
83 | /* | |
1a9ecc62 | 84 | * Iterate over path components in `left'. |
443172c4 | 85 | */ |
1a9ecc62 | 86 | while (left_len != 0) { |
87 | /* | |
88 | * Extract the next path component and adjust `left' | |
89 | * and its length. | |
90 | */ | |
91 | p = strchr(left, '/'); | |
92 | s = p ? p : left + left_len; | |
93 | if (s - left >= sizeof(next_token)) { | |
94 | errno = ENAMETOOLONG; | |
95 | return (NULL); | |
443172c4 | 96 | } |
1a9ecc62 | 97 | memcpy(next_token, left, s - left); |
98 | next_token[s - left] = '\0'; | |
99 | left_len -= s - left; | |
100 | if (p != NULL) | |
101 | memmove(left, s + 1, left_len + 1); | |
102 | if (resolved[resolved_len - 1] != '/') { | |
103 | if (resolved_len + 1 >= PATH_MAX) { | |
104 | errno = ENAMETOOLONG; | |
105 | return (NULL); | |
443172c4 | 106 | } |
1a9ecc62 | 107 | resolved[resolved_len++] = '/'; |
108 | resolved[resolved_len] = '\0'; | |
443172c4 | 109 | } |
1a9ecc62 | 110 | if (next_token[0] == '\0') |
111 | continue; | |
112 | else if (strcmp(next_token, ".") == 0) | |
113 | continue; | |
114 | else if (strcmp(next_token, "..") == 0) { | |
115 | /* | |
116 | * Strip the last path component except when we have | |
117 | * single "/" | |
118 | */ | |
119 | if (resolved_len > 1) { | |
120 | resolved[resolved_len - 1] = '\0'; | |
121 | q = strrchr(resolved, '/') + 1; | |
122 | *q = '\0'; | |
123 | resolved_len = q - resolved; | |
124 | } | |
125 | continue; | |
443172c4 | 126 | } |
443172c4 | 127 | |
1a9ecc62 | 128 | /* |
129 | * Append the next path component and lstat() it. If | |
130 | * lstat() fails we still can return successfully if | |
131 | * there are no more path components left. | |
132 | */ | |
133 | resolved_len = strlcat(resolved, next_token, PATH_MAX); | |
134 | if (resolved_len >= PATH_MAX) { | |
667abcc6 | 135 | errno = ENAMETOOLONG; |
1a9ecc62 | 136 | return (NULL); |
667abcc6 | 137 | } |
1a9ecc62 | 138 | if (lstat(resolved, &sb) != 0) { |
139 | if (errno == ENOENT && p == NULL) { | |
140 | errno = serrno; | |
141 | return (resolved); | |
667abcc6 | 142 | } |
1a9ecc62 | 143 | return (NULL); |
667abcc6 | 144 | } |
1a9ecc62 | 145 | if (S_ISLNK(sb.st_mode)) { |
146 | if (symlinks++ > MAXSYMLINKS) { | |
147 | errno = ELOOP; | |
148 | return (NULL); | |
149 | } | |
150 | slen = readlink(resolved, symlink, sizeof(symlink) - 1); | |
151 | if (slen < 0) | |
152 | return (NULL); | |
153 | symlink[slen] = '\0'; | |
154 | if (symlink[0] == '/') { | |
155 | resolved[1] = 0; | |
156 | resolved_len = 1; | |
157 | } else if (resolved_len > 1) { | |
158 | /* Strip the last path component. */ | |
159 | resolved[resolved_len - 1] = '\0'; | |
160 | q = strrchr(resolved, '/') + 1; | |
161 | *q = '\0'; | |
162 | resolved_len = q - resolved; | |
163 | } | |
443172c4 | 164 | |
1a9ecc62 | 165 | /* |
166 | * If there are any path components left, then | |
167 | * append them to symlink. The result is placed | |
168 | * in `left'. | |
169 | */ | |
170 | if (p != NULL) { | |
171 | if (symlink[slen - 1] != '/') { | |
172 | if (slen + 1 >= sizeof(symlink)) { | |
173 | errno = ENAMETOOLONG; | |
174 | return (NULL); | |
175 | } | |
176 | symlink[slen] = '/'; | |
177 | symlink[slen + 1] = 0; | |
178 | } | |
179 | left_len = strlcat(symlink, left, sizeof(left)); | |
180 | if (left_len >= sizeof(left)) { | |
181 | errno = ENAMETOOLONG; | |
182 | return (NULL); | |
183 | } | |
184 | } | |
185 | left_len = strlcpy(left, symlink, sizeof(left)); | |
186 | } | |
443172c4 | 187 | } |
667abcc6 | 188 | |
1a9ecc62 | 189 | /* |
190 | * Remove trailing slash except when the resolved pathname | |
191 | * is a single "/". | |
192 | */ | |
193 | if (resolved_len > 1 && resolved[resolved_len - 1] == '/') | |
194 | resolved[resolved_len - 1] = '\0'; | |
443172c4 | 195 | return (resolved); |
443172c4 | 196 | } |
197 | #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */ |