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 #include <lua.h>
56 #include "lauxlib.h"
57 #include "lfs.h"
58 #include "lstd.h"
59 #include "lutils.h"
60 #include "bootstrap.h"
61
62 #ifndef nitems
63 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
64 #endif
65
66 /*
67 * The goal is to emulate a subset of the upstream Lua FileSystem library, as
68 * faithfully as possible in the boot environment. Only APIs that seem useful
69 * need to emulated.
70 *
71 * Example usage:
72 *
73 * for file in lfs.dir("/boot") do
74 * print("\t"..file)
75 * end
76 *
77 * Prints:
78 * .
79 * ..
80 * (etc.)
81 *
82 * The other available API is lfs.attributes(), which functions somewhat like
83 * stat(2) and returns a table of values. Example code:
84 *
85 * attrs, errormsg, errorcode = lfs.attributes("/boot")
86 * if attrs == nil then
87 * print(errormsg)
88 * return errorcode
89 * end
90 *
91 * for k, v in pairs(attrs) do
92 * print(k .. ":\t" .. v)
93 * end
94 * return 0
95 *
96 * Prints (on success):
97 * gid: 0
98 * change: 140737488342640
99 * mode: directory
100 * rdev: 0
101 * ino: 4199275
102 * dev: 140737488342544
103 * modification: 140737488342576
104 * size: 512
105 * access: 140737488342560
106 * permissions: 755
107 * nlink: 58283552
108 * uid: 1001
109 */
110
111 #define DIR_METATABLE "directory iterator metatable"
112
113 static int
lua_dir_iter_next(lua_State * L)114 lua_dir_iter_next(lua_State *L)
115 {
116 struct dirent *entry;
117 DIR *dp, **dpp;
118
119 dpp = (DIR **)luaL_checkudata(L, 1, DIR_METATABLE);
120 dp = *dpp;
121 luaL_argcheck(L, dp != NULL, 1, "closed directory");
122
123 entry = readdirfd(dp->fd);
124 if (entry == NULL) {
125 closedir(dp);
126 *dpp = NULL;
127 return 0;
128 }
129
130 lua_pushstring(L, entry->d_name);
131 return 1;
132 }
133
134 static int
lua_dir_iter_close(lua_State * L)135 lua_dir_iter_close(lua_State *L)
136 {
137 DIR *dp, **dpp;
138
139 dpp = (DIR **)lua_touserdata(L, 1);
140 dp = *dpp;
141 if (dp == NULL)
142 return 0;
143
144 closedir(dp);
145 *dpp = NULL;
146 return 0;
147 }
148
149 static int
lua_dir(lua_State * L)150 lua_dir(lua_State *L)
151 {
152 const char *path;
153 DIR *dp;
154
155 if (lua_gettop(L) != 1) {
156 lua_pushnil(L);
157 return 1;
158 }
159
160 path = luaL_checkstring(L, 1);
161 dp = opendir(path);
162 if (dp == NULL) {
163 lua_pushnil(L);
164 return 1;
165 }
166
167 lua_pushcfunction(L, lua_dir_iter_next);
168 *(DIR **)lua_newuserdata(L, sizeof(DIR **)) = dp;
169 luaL_getmetatable(L, DIR_METATABLE);
170 lua_setmetatable(L, -2);
171 return 2;
172 }
173
174 static void
register_metatable(lua_State * L)175 register_metatable(lua_State *L)
176 {
177 /*
178 * Create so-called metatable for iterator object returned by
179 * lfs.dir().
180 */
181 luaL_newmetatable(L, DIR_METATABLE);
182
183 lua_newtable(L);
184 lua_pushcfunction(L, lua_dir_iter_next);
185 lua_setfield(L, -2, "next");
186 lua_pushcfunction(L, lua_dir_iter_close);
187 lua_setfield(L, -2, "close");
188
189 /* Magically associate anonymous method table with metatable. */
190 lua_setfield(L, -2, "__index");
191 /* Implement magic destructor method */
192 lua_pushcfunction(L, lua_dir_iter_close);
193 lua_setfield(L, -2, "__gc");
194
195 lua_pop(L, 1);
196 }
197
198 #define PUSH_INTEGER(lname, stname) \
199 static void \
200 push_st_ ## lname (lua_State *L, struct stat *sb) \
201 { \
202 lua_pushinteger(L, (lua_Integer)sb->st_ ## stname); \
203 }
PUSH_INTEGER(dev,dev)204 PUSH_INTEGER(dev, dev)
205 PUSH_INTEGER(ino, ino)
206 PUSH_INTEGER(nlink, nlink)
207 PUSH_INTEGER(uid, uid)
208 PUSH_INTEGER(gid, gid)
209 PUSH_INTEGER(rdev, rdev)
210 PUSH_INTEGER(access, atime)
211 PUSH_INTEGER(modification, mtime)
212 PUSH_INTEGER(change, ctime)
213 PUSH_INTEGER(size, size)
214 #undef PUSH_INTEGER
215
216 static void
217 push_st_mode(lua_State *L, struct stat *sb)
218 {
219 const char *mode_s;
220 mode_t mode;
221
222 mode = (sb->st_mode & S_IFMT);
223 if (S_ISREG(mode))
224 mode_s = "file";
225 else if (S_ISDIR(mode))
226 mode_s = "directory";
227 else if (S_ISLNK(mode))
228 mode_s = "link";
229 else if (S_ISSOCK(mode))
230 mode_s = "socket";
231 else if (S_ISFIFO(mode))
232 mode_s = "fifo";
233 else if (S_ISCHR(mode))
234 mode_s = "char device";
235 else if (S_ISBLK(mode))
236 mode_s = "block device";
237 else
238 mode_s = "other";
239
240 lua_pushstring(L, mode_s);
241 }
242
243 static void
push_st_permissions(lua_State * L,struct stat * sb)244 push_st_permissions(lua_State *L, struct stat *sb)
245 {
246 char buf[20];
247
248 /*
249 * XXX
250 * Could actually format as "-rwxrwxrwx" -- do we care?
251 */
252 snprintf(buf, sizeof(buf), "%o", sb->st_mode & ~S_IFMT);
253 lua_pushstring(L, buf);
254 }
255
256 #define PUSH_ENTRY(n) { #n, push_st_ ## n }
257 struct stat_members {
258 const char *name;
259 void (*push)(lua_State *, struct stat *);
260 } members[] = {
261 PUSH_ENTRY(mode),
262 PUSH_ENTRY(dev),
263 PUSH_ENTRY(ino),
264 PUSH_ENTRY(nlink),
265 PUSH_ENTRY(uid),
266 PUSH_ENTRY(gid),
267 PUSH_ENTRY(rdev),
268 PUSH_ENTRY(access),
269 PUSH_ENTRY(modification),
270 PUSH_ENTRY(change),
271 PUSH_ENTRY(size),
272 PUSH_ENTRY(permissions),
273 };
274 #undef PUSH_ENTRY
275
276 static int
lua_attributes(lua_State * L)277 lua_attributes(lua_State *L)
278 {
279 struct stat sb;
280 const char *path, *member;
281 size_t i;
282 int rc;
283
284 path = luaL_checkstring(L, 1);
285 if (path == NULL) {
286 lua_pushnil(L);
287 lua_pushfstring(L, "cannot convert first argument to string");
288 lua_pushinteger(L, EINVAL);
289 return 3;
290 }
291
292 rc = stat(path, &sb);
293 if (rc != 0) {
294 lua_pushnil(L);
295 lua_pushfstring(L,
296 "cannot obtain information from file '%s': %s", path,
297 strerror(errno));
298 lua_pushinteger(L, errno);
299 return 3;
300 }
301
302 if (lua_isstring(L, 2)) {
303 member = lua_tostring(L, 2);
304 for (i = 0; i < nitems(members); i++) {
305 if (strcmp(members[i].name, member) != 0)
306 continue;
307
308 members[i].push(L, &sb);
309 return 1;
310 }
311 return luaL_error(L, "invalid attribute name '%s'", member);
312 }
313
314 /* Create or reuse existing table */
315 lua_settop(L, 2);
316 if (!lua_istable(L, 2))
317 lua_newtable(L);
318
319 /* Export all stat data to caller */
320 for (i = 0; i < nitems(members); i++) {
321 lua_pushstring(L, members[i].name);
322 members[i].push(L, &sb);
323 lua_rawset(L, -3);
324 }
325 return 1;
326 }
327
328 #define REG_SIMPLE(n) { #n, lua_ ## n }
329 static const struct luaL_Reg fslib[] = {
330 REG_SIMPLE(attributes),
331 REG_SIMPLE(dir),
332 { NULL, NULL },
333 };
334 #undef REG_SIMPLE
335
336 int
luaopen_lfs(lua_State * L)337 luaopen_lfs(lua_State *L)
338 {
339 register_metatable(L);
340 luaL_newlib(L, fslib);
341 return 1;
342 }
343