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comparison src/realpath.c @ 446:1ccc32a20af4 r21-2-38

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Import from CVS: tag r21-2-38
author cvs
date Mon, 13 Aug 2007 11:37:21 +0200
parents abe6d1db359e
children 0784d089fdc9
comparison
equal deleted inserted replaced
445:34f3776fcf0e 446:1ccc32a20af4
21 Boston, MA 02111-1307, USA. */ 21 Boston, MA 02111-1307, USA. */
22 22
23 /* Synched up with: Not in FSF. */ 23 /* Synched up with: Not in FSF. */
24 24
25 #include <config.h> 25 #include <config.h>
26 26 #include "lisp.h"
27 #include <sys/types.h>
28 #include <stdio.h>
29 #include <string.h>
30 #include <errno.h> 27 #include <errno.h>
31 #include <limits.h>
32 28
33 #ifdef HAVE_UNISTD_H 29 #ifdef HAVE_UNISTD_H
34 #include <unistd.h> 30 #include <unistd.h>
35 #endif 31 #endif
36 32
37 #if defined (HAVE_SYS_PARAM_H) 33 #if defined (HAVE_SYS_PARAM_H) && !defined (WIN32_NATIVE)
38 #include <sys/param.h> 34 #include <sys/param.h>
39 #endif 35 #endif
40 36
41 #ifdef WIN32_NATIVE 37 #ifdef WIN32_NATIVE
42 #include <direct.h> 38 #include <direct.h>
43 #endif 39 #endif
44 40
45 #include <sys/stat.h> /* for S_IFLNK */ 41 #include <sys/stat.h> /* for S_IFLNK */
42
43 /* First char after start of absolute filename. */
44 #define ABS_START(name) (name + ABS_LENGTH (name))
45
46 #if defined (WIN32_NATIVE)
47 /* Length of start of absolute filename. */
48 # define ABS_LENGTH(name) (win32_abs_start (name))
49 static int win32_abs_start (const char * name);
50 /* System dependent version of readlink. */
51 # define system_readlink win32_readlink
52 #else
53 # ifdef CYGWIN
54 # define ABS_LENGTH(name) (IS_DIRECTORY_SEP (*name) ? \
55 (IS_DIRECTORY_SEP (name[1]) ? 2 : 1) : 0)
56 # define system_readlink cygwin_readlink
57 # else
58 # define ABS_LENGTH(name) (IS_DIRECTORY_SEP (*name) ? 1 : 0)
59 # define system_readlink readlink
60 # endif /* CYGWIN */
61 #endif /* WIN32_NATIVE */
62
63 #if defined (WIN32_NATIVE) || defined (CYGWIN)
64 #include "syswindows.h"
65 /* Emulate readlink on win32 - finds real name (i.e. correct case) of
66 a file. UNC servers and shares are lower-cased. Directories must be
67 given without trailing '/'. One day, this could read Win2K's
68 reparse points. */
69 static int
70 win32_readlink (const char * name, char * buf, int size)
71 {
72 WIN32_FIND_DATA find_data;
73 HANDLE dir_handle = NULL;
74 int len = 0;
75 int err = 0;
76 const char* lastname;
77 int count = 0;
78 const char* tmp;
79 char* res = NULL;
80
81 assert (*name);
82
83 /* Sort of check we have a valid filename. */
84 if (strpbrk (name, "*?|<>\"") || strlen (name) >= MAX_PATH)
85 {
86 errno = EIO;
87 return -1;
88 }
89
90 /* Find start of filename */
91 lastname = name + strlen (name);
92 while (lastname > name && !IS_DIRECTORY_SEP (lastname[-1]))
93 --lastname;
94
95 /* Count slashes in unc path */
96 if (ABS_LENGTH (name) == 2)
97 for (tmp = name; *tmp; tmp++)
98 if (IS_DIRECTORY_SEP (*tmp))
99 count++;
100
101 if (count >= 2 && count < 4)
102 {
103 /* UNC server or share name: just copy lowercased name. */
104 res = find_data.cFileName;
105 for (tmp = lastname; *tmp; tmp++)
106 *res++ = tolower (*tmp);
107 *res = '\0';
108 }
109 else
110 dir_handle = FindFirstFile (name, &find_data);
111
112 if (res || dir_handle != INVALID_HANDLE_VALUE)
113 {
114 if ((len = strlen (find_data.cFileName)) < size)
115 {
116 if (strcmp (lastname, find_data.cFileName) == 0)
117 /* Signal that the name is already OK. */
118 err = EINVAL;
119 else
120 memcpy (buf, find_data.cFileName, len + 1);
121 }
122 else
123 err = ENAMETOOLONG;
124 if (!res) FindClose (dir_handle);
125 }
126 else
127 err = ENOENT;
128
129 errno = err;
130 return err ? -1 : len;
131 }
132 #endif /* WIN32_NATIVE || CYGWIN */
133
134 #ifdef CYGWIN
135 /* Call readlink and try to find out the correct case for the file. */
136 static int
137 cygwin_readlink (const char * name, char * buf, int size)
138 {
139 int n = readlink (name, buf, size);
140 if (n < 0)
141 {
142 /* The file may exist, but isn't a symlink. Try to find the
143 right name. */
144 char* tmp = alloca (cygwin_posix_to_win32_path_list_buf_size (name));
145 cygwin_posix_to_win32_path_list (name, tmp);
146 n = win32_readlink (tmp, buf, size);
147 }
148 return n;
149 }
150 #endif /* CYGWIN */
151
152 #ifdef WIN32_NATIVE
153 #ifndef ELOOP
154 #define ELOOP 10062 /* = WSAELOOP in winsock.h */
155 #endif
156 /* Length of start of absolute filename. */
157 static int
158 win32_abs_start (const char * name)
159 {
160 if (isalpha (*name) && IS_DEVICE_SEP (name[1])
161 && IS_DIRECTORY_SEP (name[2]))
162 return 3;
163 else if (IS_DIRECTORY_SEP (*name))
164 return IS_DIRECTORY_SEP (name[1]) ? 2 : 1;
165 else
166 return 0;
167 }
168 #endif /* WIN32_NATIVE */
46 169
47 #if !defined (HAVE_GETCWD) && defined (HAVE_GETWD) 170 #if !defined (HAVE_GETCWD) && defined (HAVE_GETWD)
48 #undef getcwd 171 #undef getcwd
49 #define getcwd(buffer, len) getwd (buffer) 172 #define getcwd(buffer, len) getwd (buffer)
50 #endif 173 #endif
66 xrealpath (const char *path, char resolved_path []) 189 xrealpath (const char *path, char resolved_path [])
67 { 190 {
68 char copy_path[PATH_MAX]; 191 char copy_path[PATH_MAX];
69 char *new_path = resolved_path; 192 char *new_path = resolved_path;
70 char *max_path; 193 char *max_path;
71 #ifdef S_IFLNK 194 #if defined (S_IFLNK) || defined (WIN32_NATIVE)
72 int readlinks = 0; 195 int readlinks = 0;
73 char link_path[PATH_MAX]; 196 char link_path[PATH_MAX];
74 int n; 197 int n;
198 int abslen = ABS_LENGTH (path);
75 #endif 199 #endif
76 200
77 /* Make a copy of the source path since we may need to modify it. */ 201 /* Make a copy of the source path since we may need to modify it. */
78 strcpy (copy_path, path); 202 strcpy (copy_path, path);
79 path = copy_path; 203 path = copy_path;
80 max_path = copy_path + PATH_MAX - 2; 204 max_path = copy_path + PATH_MAX - 2;
205
81 #ifdef WIN32_NATIVE 206 #ifdef WIN32_NATIVE
82 /* 207 /* Check for c:/... or //server/... */
83 ** In NT we have two different cases: (1) the path name begins 208 if (abslen == 2 || abslen == 3)
84 ** with a drive letter, e.g., "C:"; and (2) the path name begins 209 {
85 ** with just a slash, which roots to the current drive. In the 210 strncpy (new_path, path, abslen);
86 ** first case we are going to leave things alone, in the second 211 new_path += abslen;
87 ** case we will prepend the drive letter to the given path. 212 path += abslen;
88 ** Note: So far in testing, I'm only seeing case #1, even though 213 }
89 ** I've tried to get the other cases to happen. 214 /* No drive letter, but a beginning slash? Prepend drive letter. */
90 ** August Hill, 31 Aug 1997. 215 else if (abslen == 1)
91 **
92 ** Check for a driver letter...C:/...
93 */
94 if (*(path + 1) == ':')
95 {
96 strncpy(new_path, path, 3);
97 new_path += 3;
98 path += 3;
99 }
100
101 /*
102 ** No drive letter, but a beginning slash? Prepend the drive
103 ** letter...
104 */
105 else if (*path == '/')
106 { 216 {
107 getcwd (new_path, PATH_MAX - 1); 217 getcwd (new_path, PATH_MAX - 1);
108 new_path += 3; 218 new_path += 3;
109 path++; 219 path++;
110 } 220 }
111 221 /* Just a path name, prepend the current directory */
112 /*
113 ** Just a path name, prepend the current directory
114 */
115 else 222 else
116 { 223 {
117 getcwd (new_path, PATH_MAX - 1); 224 getcwd (new_path, PATH_MAX - 1);
118 new_path += strlen(new_path); 225 new_path += strlen (new_path);
119 if (new_path[-1] != '/') 226 if (!IS_DIRECTORY_SEP (new_path[-1]))
120 *new_path++ = '/'; 227 *new_path++ = DIRECTORY_SEP;
121 } 228 }
122
123 #else 229 #else
124 /* If it's a relative pathname use getcwd for starters. */ 230 /* If it's a relative pathname use getcwd for starters. */
125 if (*path != '/') 231 if (abslen == 0)
126 { 232 {
127 getcwd (new_path, PATH_MAX - 1); 233 getcwd (new_path, PATH_MAX - 1);
128 new_path += strlen(new_path); 234 new_path += strlen (new_path);
129 if (new_path[-1] != '/') 235 if (!IS_DIRECTORY_SEP (new_path[-1]))
130 *new_path++ = '/'; 236 *new_path++ = DIRECTORY_SEP;
131 } 237 }
132 else 238 else
133 { 239 {
134 *new_path++ = '/'; 240 /* Copy first directory sep. May have two on cygwin. */
135 path++; 241 strncpy (new_path, path, abslen);
242 new_path += abslen;
243 path += abslen;
136 } 244 }
137 #endif 245 #endif
138 /* Expand each slash-separated pathname component. */ 246 /* Expand each slash-separated pathname component. */
139 while (*path != '\0') 247 while (*path != '\0')
140 { 248 {
141 /* Ignore stray "/". */ 249 /* Ignore stray "/". */
142 if (*path == '/') 250 if (IS_DIRECTORY_SEP (*path))
143 { 251 {
144 path++; 252 path++;
145 continue; 253 continue;
146 } 254 }
147 255
148 if (*path == '.') 256 if (*path == '.')
149 { 257 {
150 /* Ignore ".". */ 258 /* Ignore ".". */
151 if (path[1] == '\0' || path[1] == '/') 259 if (path[1] == '\0' || IS_DIRECTORY_SEP (path[1]))
152 { 260 {
153 path++; 261 path++;
154 continue; 262 continue;
155 } 263 }
156 264
157 /* Handle ".." */ 265 /* Handle ".." */
158 if (path[1] == '.' && 266 if (path[1] == '.' &&
159 (path[2] == '\0' || path[2] == '/')) 267 (path[2] == '\0' || IS_DIRECTORY_SEP (path[2])))
160 { 268 {
161 path += 2; 269 path += 2;
162 270
163 /* Ignore ".." at root. */ 271 /* Ignore ".." at root. */
164 if (new_path == resolved_path + 1) 272 if (new_path == ABS_START (resolved_path))
165 continue; 273 continue;
166 274
167 /* Handle ".." by backing up. */ 275 /* Handle ".." by backing up. */
168 while ((--new_path)[-1] != '/') 276 --new_path;
169 ; 277 while (!IS_DIRECTORY_SEP (new_path[-1]))
278 --new_path;
170 continue; 279 continue;
171 } 280 }
172 } 281 }
173 282
174 /* Safely copy the next pathname component. */ 283 /* Safely copy the next pathname component. */
175 while (*path != '\0' && *path != '/') 284 while (*path != '\0' && !IS_DIRECTORY_SEP (*path))
176 { 285 {
177 if (path > max_path) 286 if (path > max_path)
178 { 287 {
179 errno = ENAMETOOLONG; 288 errno = ENAMETOOLONG;
180 return NULL; 289 return NULL;
181 } 290 }
182 *new_path++ = *path++; 291 *new_path++ = *path++;
183 } 292 }
184 293
185 #ifdef S_IFLNK 294 #if defined (S_IFLNK) || defined (WIN32_NATIVE)
186 /* See if latest pathname component is a symlink. */ 295 /* See if latest pathname component is a symlink. */
187 *new_path = '\0'; 296 *new_path = '\0';
188 n = readlink (resolved_path, link_path, PATH_MAX - 1); 297 n = system_readlink (resolved_path, link_path, PATH_MAX - 1);
189 298
190 if (n < 0) 299 if (n < 0)
191 { 300 {
192 /* EINVAL means the file exists but isn't a symlink. */ 301 /* EINVAL means the file exists but isn't a symlink. */
193 if (errno != EINVAL) 302 if (errno != EINVAL)
202 return NULL; 311 return NULL;
203 } 312 }
204 313
205 /* Note: readlink doesn't add the null byte. */ 314 /* Note: readlink doesn't add the null byte. */
206 link_path[n] = '\0'; 315 link_path[n] = '\0';
207 316
208 if (*link_path == '/') 317 if (ABS_LENGTH (link_path) > 0)
209 /* Start over for an absolute symlink. */ 318 /* Start over for an absolute symlink. */
210 new_path = resolved_path; 319 new_path = resolved_path + ABS_LENGTH (link_path) - 1;
211 else 320 else
212 /* Otherwise back up over this component. */ 321 /* Otherwise back up over this component. */
213 while (*(--new_path) != '/') 322 for (--new_path; !IS_DIRECTORY_SEP (*new_path); --new_path)
214 ; 323 assert (new_path > resolved_path);
215 324
216 /* Safe sex check. */ 325 /* Safe sex check. */
217 if (strlen(path) + n >= PATH_MAX) 326 if (strlen(path) + n >= PATH_MAX)
218 { 327 {
219 errno = ENAMETOOLONG; 328 errno = ENAMETOOLONG;
223 /* Insert symlink contents into path. */ 332 /* Insert symlink contents into path. */
224 strcat(link_path, path); 333 strcat(link_path, path);
225 strcpy(copy_path, link_path); 334 strcpy(copy_path, link_path);
226 path = copy_path; 335 path = copy_path;
227 } 336 }
228 #endif /* S_IFLNK */ 337 #endif /* S_IFLNK || WIN32_NATIVE */
229 *new_path++ = '/'; 338 *new_path++ = DIRECTORY_SEP;
230 } 339 }
231 340
232 /* Delete trailing slash but don't whomp a lone slash. */ 341 /* Delete trailing slash but don't whomp a lone slash. */
233 if (new_path != resolved_path + 1 && new_path[-1] == '/') 342 if (new_path != ABS_START (resolved_path) && IS_DIRECTORY_SEP (new_path[-1]))
234 new_path--; 343 new_path--;
235 344
236 /* Make sure it's null terminated. */ 345 /* Make sure it's null terminated. */
237 *new_path = '\0'; 346 *new_path = '\0';
347
348 #ifdef WIN32_NATIVE
349 if (ABS_LENGTH (resolved_path) == 3)
350 /* Lowercase drive letter. */
351 *resolved_path = tolower (*resolved_path);
352 #endif
238 return resolved_path; 353 return resolved_path;
239 } 354 }