1 /*-
2 * Copyright (c) 2018 Conrad Meyer <[email protected]>
3 * All rights reserved.
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.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * Portions derived from https://github.com/keplerproject/luafilesystem under
27 * the terms of the MIT license:
28 *
29 * Copyright (c) 2003-2014 Kepler Project.
30 *
31 * Permission is hereby granted, free of charge, to any person
32 * obtaining a copy of this software and associated documentation
33 * files (the "Software"), to deal in the Software without
34 * restriction, including without limitation the rights to use, copy,
35 * modify, merge, publish, distribute, sublicense, and/or sell copies
36 * of the Software, and to permit persons to whom the Software is
37 * furnished to do so, subject to the following conditions:
38 *
39 * The above copyright notice and this permission notice shall be
40 * included in all copies or substantial portions of the Software.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
43 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
44 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
45 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
46 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
47 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
48 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
49 * SOFTWARE.
50 */
51
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54
55 #ifndef _STANDALONE
56 #include <sys/stat.h>
57 #include <dirent.h>
58 #include <errno.h>
59 #include <unistd.h>
60 #include <stdio.h>
61 #include <string.h>
62 #endif
63
64 #include <lua.h>
65 #include "lauxlib.h"
66 #include "lfs.h"
67
68 #ifdef _STANDALONE
69 #include "lstd.h"
70 #include "lutils.h"
71 #include "bootstrap.h"
72 #endif
73
74 #ifndef nitems
75 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
76 #endif
77
78 /*
79 * The goal is to emulate a subset of the upstream Lua FileSystem library, as
80 * faithfully as possible in the boot environment. Only APIs that seem useful
81 * need to emulated.
82 *
83 * Example usage:
84 *
85 * for file in lfs.dir("/boot") do
86 * print("\t"..file)
87 * end
88 *
89 * Prints:
90 * .
91 * ..
92 * (etc.)
93 *
94 * The other available API is lfs.attributes(), which functions somewhat like
95 * stat(2) and returns a table of values. Example code:
96 *
97 * attrs, errormsg, errorcode = lfs.attributes("/boot")
98 * if attrs == nil then
99 * print(errormsg)
100 * return errorcode
101 * end
102 *
103 * for k, v in pairs(attrs) do
104 * print(k .. ":\t" .. v)
105 * end
106 * return 0
107 *
108 * Prints (on success):
109 * gid: 0
110 * change: 140737488342640
111 * mode: directory
112 * rdev: 0
113 * ino: 4199275
114 * dev: 140737488342544
115 * modification: 140737488342576
116 * size: 512
117 * access: 140737488342560
118 * permissions: 755
119 * nlink: 58283552
120 * uid: 1001
121 */
122
123 #define DIR_METATABLE "directory iterator metatable"
124
125 static int
lua_dir_iter_pushtype(lua_State * L __unused,const struct dirent * ent __unused)126 lua_dir_iter_pushtype(lua_State *L __unused, const struct dirent *ent __unused)
127 {
128
129 /*
130 * This is a non-standard extension to luafilesystem for loader's
131 * benefit. The extra stat() calls to determine the entry type can
132 * be quite expensive on some systems, so this speeds up enumeration of
133 * /boot greatly by providing the type up front.
134 *
135 * This extension is compatible enough with luafilesystem, in that we're
136 * just using an extra return value for the iterator.
137 */
138 #ifdef _STANDALONE
139 lua_pushinteger(L, ent->d_type);
140 return 1;
141 #else
142 return 0;
143 #endif
144 }
145
146 static int
lua_dir_iter_next(lua_State * L)147 lua_dir_iter_next(lua_State *L)
148 {
149 struct dirent *entry;
150 DIR *dp, **dpp;
151
152 dpp = (DIR **)luaL_checkudata(L, 1, DIR_METATABLE);
153 dp = *dpp;
154 luaL_argcheck(L, dp != NULL, 1, "closed directory");
155
156 #ifdef _STANDALONE
157 entry = readdirfd(dp->fd);
158 #else
159 entry = readdir(dp);
160 #endif
161 if (entry == NULL) {
162 closedir(dp);
163 *dpp = NULL;
164 return 0;
165 }
166
167 lua_pushstring(L, entry->d_name);
168 return 1 + lua_dir_iter_pushtype(L, entry);
169 }
170
171 static int
lua_dir_iter_close(lua_State * L)172 lua_dir_iter_close(lua_State *L)
173 {
174 DIR *dp, **dpp;
175
176 dpp = (DIR **)lua_touserdata(L, 1);
177 dp = *dpp;
178 if (dp == NULL)
179 return 0;
180
181 closedir(dp);
182 *dpp = NULL;
183 return 0;
184 }
185
186 static int
lua_dir(lua_State * L)187 lua_dir(lua_State *L)
188 {
189 const char *path;
190 DIR *dp;
191
192 if (lua_gettop(L) != 1) {
193 lua_pushnil(L);
194 return 1;
195 }
196
197 path = luaL_checkstring(L, 1);
198 dp = opendir(path);
199 if (dp == NULL) {
200 lua_pushnil(L);
201 return 1;
202 }
203
204 lua_pushcfunction(L, lua_dir_iter_next);
205 *(DIR **)lua_newuserdata(L, sizeof(DIR **)) = dp;
206 luaL_getmetatable(L, DIR_METATABLE);
207 lua_setmetatable(L, -2);
208 return 2;
209 }
210
211 static void
register_metatable(lua_State * L)212 register_metatable(lua_State *L)
213 {
214 /*
215 * Create so-called metatable for iterator object returned by
216 * lfs.dir().
217 */
218 luaL_newmetatable(L, DIR_METATABLE);
219
220 lua_newtable(L);
221 lua_pushcfunction(L, lua_dir_iter_next);
222 lua_setfield(L, -2, "next");
223 lua_pushcfunction(L, lua_dir_iter_close);
224 lua_setfield(L, -2, "close");
225
226 /* Magically associate anonymous method table with metatable. */
227 lua_setfield(L, -2, "__index");
228 /* Implement magic destructor method */
229 lua_pushcfunction(L, lua_dir_iter_close);
230 lua_setfield(L, -2, "__gc");
231
232 lua_pop(L, 1);
233 }
234
235 #define PUSH_INTEGER(lname, stname) \
236 static void \
237 push_st_ ## lname (lua_State *L, struct stat *sb) \
238 { \
239 lua_pushinteger(L, (lua_Integer)sb->st_ ## stname); \
240 }
PUSH_INTEGER(dev,dev)241 PUSH_INTEGER(dev, dev)
242 PUSH_INTEGER(ino, ino)
243 PUSH_INTEGER(nlink, nlink)
244 PUSH_INTEGER(uid, uid)
245 PUSH_INTEGER(gid, gid)
246 PUSH_INTEGER(rdev, rdev)
247 PUSH_INTEGER(access, atime)
248 PUSH_INTEGER(modification, mtime)
249 PUSH_INTEGER(change, ctime)
250 PUSH_INTEGER(size, size)
251 #undef PUSH_INTEGER
252
253 static void
254 push_st_mode(lua_State *L, struct stat *sb)
255 {
256 const char *mode_s;
257 mode_t mode;
258
259 mode = (sb->st_mode & S_IFMT);
260 if (S_ISREG(mode))
261 mode_s = "file";
262 else if (S_ISDIR(mode))
263 mode_s = "directory";
264 else if (S_ISLNK(mode))
265 mode_s = "link";
266 else if (S_ISSOCK(mode))
267 mode_s = "socket";
268 else if (S_ISFIFO(mode))
269 mode_s = "fifo";
270 else if (S_ISCHR(mode))
271 mode_s = "char device";
272 else if (S_ISBLK(mode))
273 mode_s = "block device";
274 else
275 mode_s = "other";
276
277 lua_pushstring(L, mode_s);
278 }
279
280 static void
push_st_permissions(lua_State * L,struct stat * sb)281 push_st_permissions(lua_State *L, struct stat *sb)
282 {
283 char buf[20];
284
285 /*
286 * XXX
287 * Could actually format as "-rwxrwxrwx" -- do we care?
288 */
289 snprintf(buf, sizeof(buf), "%o", sb->st_mode & ~S_IFMT);
290 lua_pushstring(L, buf);
291 }
292
293 #define PUSH_ENTRY(n) { #n, push_st_ ## n }
294 struct stat_members {
295 const char *name;
296 void (*push)(lua_State *, struct stat *);
297 } members[] = {
298 PUSH_ENTRY(mode),
299 PUSH_ENTRY(dev),
300 PUSH_ENTRY(ino),
301 PUSH_ENTRY(nlink),
302 PUSH_ENTRY(uid),
303 PUSH_ENTRY(gid),
304 PUSH_ENTRY(rdev),
305 PUSH_ENTRY(access),
306 PUSH_ENTRY(modification),
307 PUSH_ENTRY(change),
308 PUSH_ENTRY(size),
309 PUSH_ENTRY(permissions),
310 };
311 #undef PUSH_ENTRY
312
313 static int
lua_attributes(lua_State * L)314 lua_attributes(lua_State *L)
315 {
316 struct stat sb;
317 const char *path, *member;
318 size_t i;
319 int rc;
320
321 path = luaL_checkstring(L, 1);
322 if (path == NULL) {
323 lua_pushnil(L);
324 lua_pushfstring(L, "cannot convert first argument to string");
325 lua_pushinteger(L, EINVAL);
326 return 3;
327 }
328
329 rc = stat(path, &sb);
330 if (rc != 0) {
331 lua_pushnil(L);
332 lua_pushfstring(L,
333 "cannot obtain information from file '%s': %s", path,
334 strerror(errno));
335 lua_pushinteger(L, errno);
336 return 3;
337 }
338
339 if (lua_isstring(L, 2)) {
340 member = lua_tostring(L, 2);
341 for (i = 0; i < nitems(members); i++) {
342 if (strcmp(members[i].name, member) != 0)
343 continue;
344
345 members[i].push(L, &sb);
346 return 1;
347 }
348 return luaL_error(L, "invalid attribute name '%s'", member);
349 }
350
351 /* Create or reuse existing table */
352 lua_settop(L, 2);
353 if (!lua_istable(L, 2))
354 lua_newtable(L);
355
356 /* Export all stat data to caller */
357 for (i = 0; i < nitems(members); i++) {
358 lua_pushstring(L, members[i].name);
359 members[i].push(L, &sb);
360 lua_rawset(L, -3);
361 }
362 return 1;
363 }
364
365 #ifndef _STANDALONE
366 #define lfs_mkdir_impl(path) (mkdir((path), \
367 S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | \
368 S_IROTH | S_IXOTH))
369
370 static int
lua_mkdir(lua_State * L)371 lua_mkdir(lua_State *L)
372 {
373 const char *path;
374 int error, serrno;
375
376 path = luaL_checkstring(L, 1);
377 if (path == NULL) {
378 lua_pushnil(L);
379 lua_pushfstring(L, "cannot convert first argument to string");
380 lua_pushinteger(L, EINVAL);
381 return 3;
382 }
383
384 error = lfs_mkdir_impl(path);
385 if (error == -1) {
386 /* Save it; unclear what other libc functions may be invoked */
387 serrno = errno;
388 lua_pushnil(L);
389 lua_pushfstring(L, strerror(serrno));
390 lua_pushinteger(L, serrno);
391 return 3;
392 }
393
394 lua_pushboolean(L, 1);
395 return 1;
396 }
397
398 static int
lua_rmdir(lua_State * L)399 lua_rmdir(lua_State *L)
400 {
401 const char *path;
402 int error, serrno;
403
404 path = luaL_checkstring(L, 1);
405 if (path == NULL) {
406 lua_pushnil(L);
407 lua_pushfstring(L, "cannot convert first argument to string");
408 lua_pushinteger(L, EINVAL);
409 return 3;
410 }
411
412 error = rmdir(path);
413 if (error == -1) {
414 /* Save it; unclear what other libc functions may be invoked */
415 serrno = errno;
416 lua_pushnil(L);
417 lua_pushfstring(L, strerror(serrno));
418 lua_pushinteger(L, serrno);
419 return 3;
420 }
421
422 lua_pushboolean(L, 1);
423 return 1;
424 }
425 #endif
426
427 #define REG_SIMPLE(n) { #n, lua_ ## n }
428 static const struct luaL_Reg fslib[] = {
429 REG_SIMPLE(attributes),
430 REG_SIMPLE(dir),
431 #ifndef _STANDALONE
432 REG_SIMPLE(mkdir),
433 REG_SIMPLE(rmdir),
434 #endif
435 { NULL, NULL },
436 };
437 #undef REG_SIMPLE
438
439 int
luaopen_lfs(lua_State * L)440 luaopen_lfs(lua_State *L)
441 {
442 register_metatable(L);
443 luaL_newlib(L, fslib);
444 #ifdef _STANDALONE
445 /* Non-standard extension for loader, used with lfs.dir(). */
446 lua_pushinteger(L, DT_DIR);
447 lua_setfield(L, -2, "DT_DIR");
448 #endif
449 return 1;
450 }
451