1 /* Copyright (C) 1992-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <hurd.h>
19 #include <hurd/lookup.h>
20 #include <string.h>
21 #include <fcntl.h>
22
23
24 /* Translate the error from dir_lookup into the error the user sees. */
25 static inline error_t
lookup_error(error_t error)26 lookup_error (error_t error)
27 {
28 switch (error)
29 {
30 case EOPNOTSUPP:
31 case MIG_BAD_ID:
32 /* These indicate that the server does not understand dir_lookup
33 at all. If it were a directory, it would, by definition. */
34 return ENOTDIR;
35 default:
36 return error;
37 }
38 }
39
40 error_t
__hurd_file_name_lookup(error_t (* use_init_port)(int which,error_t (* operate)(file_t)),file_t (* get_dtable_port)(int fd),error_t (* lookup)(file_t dir,const char * name,int flags,mode_t mode,retry_type * do_retry,string_t retry_name,mach_port_t * result),const char * file_name,int flags,mode_t mode,file_t * result)41 __hurd_file_name_lookup (error_t (*use_init_port)
42 (int which, error_t (*operate) (file_t)),
43 file_t (*get_dtable_port) (int fd),
44 error_t (*lookup)
45 (file_t dir, const char *name, int flags, mode_t mode,
46 retry_type *do_retry, string_t retry_name,
47 mach_port_t *result),
48 const char *file_name, int flags, mode_t mode,
49 file_t *result)
50 {
51 error_t err;
52 enum retry_type doretry;
53 char retryname[1024]; /* XXX string_t LOSES! */
54 int startport;
55
56 error_t lookup_op (mach_port_t startdir)
57 {
58 return lookup_error ((*lookup) (startdir, file_name, flags, mode,
59 &doretry, retryname, result));
60 }
61
62 if (! lookup)
63 lookup = __dir_lookup;
64
65 if (file_name[0] == '\0')
66 return ENOENT;
67
68 startport = (file_name[0] == '/') ? INIT_PORT_CRDIR : INIT_PORT_CWDIR;
69 while (file_name[0] == '/')
70 file_name++;
71
72 if (flags & O_NOFOLLOW) /* See lookup-retry.c about O_NOFOLLOW. */
73 flags |= O_NOTRANS;
74
75 if (flags & O_DIRECTORY && (flags & O_NOFOLLOW) == 0)
76 {
77 /* The caller wants to require that the file we look up is a directory.
78 We can do this without an extra RPC by appending a trailing slash
79 to the file name we look up. */
80 size_t len = strlen (file_name);
81 if (len == 0)
82 file_name = "/";
83 else if (file_name[len - 1] != '/')
84 {
85 char *n = alloca (len + 2);
86 memcpy (n, file_name, len);
87 n[len] = '/';
88 n[len + 1] = '\0';
89 file_name = n;
90 }
91 }
92
93 err = (*use_init_port) (startport, &lookup_op);
94 if (! err)
95 err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port,
96 lookup, doretry, retryname,
97 flags, mode, result);
98
99 return err;
100 }
weak_alias(__hurd_file_name_lookup,hurd_file_name_lookup)101 weak_alias (__hurd_file_name_lookup, hurd_file_name_lookup)
102
103 error_t
104 __hurd_file_name_split (error_t (*use_init_port)
105 (int which, error_t (*operate) (file_t)),
106 file_t (*get_dtable_port) (int fd),
107 error_t (*lookup)
108 (file_t dir, const char *name, int flags, mode_t mode,
109 retry_type *do_retry, string_t retry_name,
110 mach_port_t *result),
111 const char *file_name,
112 file_t *dir, char **name)
113 {
114 error_t addref (file_t crdir)
115 {
116 *dir = crdir;
117 return __mach_port_mod_refs (__mach_task_self (),
118 crdir, MACH_PORT_RIGHT_SEND, +1);
119 }
120
121 const char *lastslash = strrchr (file_name, '/');
122
123 if (lastslash != NULL)
124 {
125 if (lastslash == file_name)
126 {
127 /* "/foobar" => crdir + "foobar". */
128 *name = (char *) file_name + 1;
129 return (*use_init_port) (INIT_PORT_CRDIR, &addref);
130 }
131 else
132 {
133 /* "/dir1/dir2/.../file". */
134 char dirname[lastslash - file_name + 1];
135 memcpy (dirname, file_name, lastslash - file_name);
136 dirname[lastslash - file_name] = '\0';
137 *name = (char *) lastslash + 1;
138 return
139 __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
140 dirname, 0, 0, dir);
141 }
142 }
143 else if (file_name[0] == '\0')
144 return ENOENT;
145 else
146 {
147 /* "foobar" => cwdir + "foobar". */
148 *name = (char *) file_name;
149 return (*use_init_port) (INIT_PORT_CWDIR, &addref);
150 }
151 }
weak_alias(__hurd_file_name_split,hurd_file_name_split)152 weak_alias (__hurd_file_name_split, hurd_file_name_split)
153
154 /* This is the same as hurd_file_name_split, except that it ignores
155 trailing slashes (so *NAME is never ""). */
156 error_t
157 __hurd_directory_name_split (error_t (*use_init_port)
158 (int which, error_t (*operate) (file_t)),
159 file_t (*get_dtable_port) (int fd),
160 error_t (*lookup)
161 (file_t dir, const char *name, int flags, mode_t mode,
162 retry_type *do_retry, string_t retry_name,
163 mach_port_t *result),
164 const char *file_name,
165 file_t *dir, char **name)
166 {
167 error_t addref (file_t crdir)
168 {
169 *dir = crdir;
170 return __mach_port_mod_refs (__mach_task_self (),
171 crdir, MACH_PORT_RIGHT_SEND, +1);
172 }
173
174 const char *lastslash = strrchr (file_name, '/');
175
176 if (lastslash != NULL && lastslash[1] == '\0')
177 {
178 /* Trailing slash doesn't count. Look back further. */
179
180 /* Back up over all trailing slashes. */
181 while (lastslash > file_name && *lastslash == '/')
182 --lastslash;
183
184 /* Find the last one earlier in the string, before the trailing ones. */
185 lastslash = __memrchr (file_name, '/', lastslash - file_name);
186 }
187
188 if (lastslash != NULL)
189 {
190 if (lastslash == file_name)
191 {
192 /* "/foobar" => crdir + "foobar". */
193 *name = (char *) file_name + 1;
194 return (*use_init_port) (INIT_PORT_CRDIR, &addref);
195 }
196 else
197 {
198 /* "/dir1/dir2/.../file". */
199 char dirname[lastslash - file_name + 1];
200 memcpy (dirname, file_name, lastslash - file_name);
201 dirname[lastslash - file_name] = '\0';
202 *name = (char *) lastslash + 1;
203 return
204 __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup,
205 dirname, 0, 0, dir);
206 }
207 }
208 else if (file_name[0] == '\0')
209 return ENOENT;
210 else
211 {
212 /* "foobar" => cwdir + "foobar". */
213 *name = (char *) file_name;
214 return (*use_init_port) (INIT_PORT_CWDIR, &addref);
215 }
216 }
weak_alias(__hurd_directory_name_split,hurd_directory_name_split)217 weak_alias (__hurd_directory_name_split, hurd_directory_name_split)
218
219
220 file_t
221 __file_name_lookup (const char *file_name, int flags, mode_t mode)
222 {
223 error_t err;
224 file_t result;
225
226 err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0,
227 file_name, flags, mode & ~_hurd_umask,
228 &result);
229
230 return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
231 }
weak_alias(__file_name_lookup,file_name_lookup)232 weak_alias (__file_name_lookup, file_name_lookup)
233
234
235 file_t
236 __file_name_split (const char *file_name, char **name)
237 {
238 error_t err;
239 file_t result;
240
241 err = __hurd_file_name_split (&_hurd_ports_use, &__getdport, 0,
242 file_name, &result, name);
243
244 return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
245 }
weak_alias(__file_name_split,file_name_split)246 weak_alias (__file_name_split, file_name_split)
247
248 file_t
249 __directory_name_split (const char *directory_name, char **name)
250 {
251 error_t err;
252 file_t result;
253
254 err = __hurd_directory_name_split (&_hurd_ports_use, &__getdport, 0,
255 directory_name, &result, name);
256
257 return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
258 }
weak_alias(__directory_name_split,directory_name_split)259 weak_alias (__directory_name_split, directory_name_split)
260
261
262 file_t
263 __file_name_lookup_under (file_t startdir,
264 const char *file_name, int flags, mode_t mode)
265 {
266 error_t err;
267 file_t result;
268
269 error_t use_init_port (int which, error_t (*operate) (mach_port_t))
270 {
271 return (which == INIT_PORT_CWDIR ? (*operate) (startdir)
272 : _hurd_ports_use (which, operate));
273 }
274
275 err = __hurd_file_name_lookup (&use_init_port, &__getdport, 0,
276 file_name, flags, mode & ~_hurd_umask,
277 &result);
278
279 return err ? (__hurd_fail (err), MACH_PORT_NULL) : result;
280 }
281 weak_alias (__file_name_lookup_under, file_name_lookup_under)
282