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d99a0153 CW |
1 | /* |
2 | * CDDL HEADER START | |
3 | * | |
4 | * This file and its contents are supplied under the terms of the | |
5 | * Common Development and Distribution License ("CDDL"), version 1.0. | |
6 | * You may only use this file in accordance with the terms of version | |
7 | * 1.0 of the CDDL. | |
8 | * | |
9 | * A full copy of the text of the CDDL should have accompanied this | |
10 | * source. A copy of the CDDL is also available via the Internet at | |
11 | * http://www.illumos.org/license/CDDL. | |
12 | * | |
13 | * CDDL HEADER END | |
14 | */ | |
15 | ||
16 | /* | |
917f475f | 17 | * Copyright (c) 2016, 2018 by Delphix. All rights reserved. |
d99a0153 CW |
18 | */ |
19 | ||
20 | /* | |
21 | * ZFS Channel Programs (ZCP) | |
22 | * | |
23 | * The ZCP interface allows various ZFS commands and operations ZFS | |
24 | * administrative operations (e.g. creating and destroying snapshots, typically | |
25 | * performed via an ioctl to /dev/zfs by the zfs(8) command and | |
26 | * libzfs/libzfs_core) to be run * programmatically as a Lua script. A ZCP | |
27 | * script is run as a dsl_sync_task and fully executed during one transaction | |
28 | * group sync. This ensures that no other changes can be written concurrently | |
29 | * with a running Lua script. Combining multiple calls to the exposed ZFS | |
30 | * functions into one script gives a number of benefits: | |
31 | * | |
32 | * 1. Atomicity. For some compound or iterative operations, it's useful to be | |
33 | * able to guarantee that the state of a pool has not changed between calls to | |
34 | * ZFS. | |
35 | * | |
36 | * 2. Performance. If a large number of changes need to be made (e.g. deleting | |
37 | * many filesystems), there can be a significant performance penalty as a | |
38 | * result of the need to wait for a transaction group sync to pass for every | |
39 | * single operation. When expressed as a single ZCP script, all these changes | |
40 | * can be performed at once in one txg sync. | |
41 | * | |
42 | * A modified version of the Lua 5.2 interpreter is used to run channel program | |
43 | * scripts. The Lua 5.2 manual can be found at: | |
44 | * | |
45 | * http://www.lua.org/manual/5.2/ | |
46 | * | |
47 | * If being run by a user (via an ioctl syscall), executing a ZCP script | |
48 | * requires root privileges in the global zone. | |
49 | * | |
50 | * Scripts are passed to zcp_eval() as a string, then run in a synctask by | |
51 | * zcp_eval_sync(). Arguments can be passed into the Lua script as an nvlist, | |
52 | * which will be converted to a Lua table. Similarly, values returned from | |
53 | * a ZCP script will be converted to an nvlist. See zcp_lua_to_nvlist_impl() | |
54 | * for details on exact allowed types and conversion. | |
55 | * | |
56 | * ZFS functionality is exposed to a ZCP script as a library of function calls. | |
57 | * These calls are sorted into submodules, such as zfs.list and zfs.sync, for | |
58 | * iterators and synctasks, respectively. Each of these submodules resides in | |
59 | * its own source file, with a zcp_*_info structure describing each library | |
60 | * call in the submodule. | |
61 | * | |
62 | * Error handling in ZCP scripts is handled by a number of different methods | |
63 | * based on severity: | |
64 | * | |
65 | * 1. Memory and time limits are in place to prevent a channel program from | |
66 | * consuming excessive system or running forever. If one of these limits is | |
67 | * hit, the channel program will be stopped immediately and return from | |
68 | * zcp_eval() with an error code. No attempt will be made to roll back or undo | |
69 | * any changes made by the channel program before the error occured. | |
70 | * Consumers invoking zcp_eval() from elsewhere in the kernel may pass a time | |
71 | * limit of 0, disabling the time limit. | |
72 | * | |
73 | * 2. Internal Lua errors can occur as a result of a syntax error, calling a | |
74 | * library function with incorrect arguments, invoking the error() function, | |
75 | * failing an assert(), or other runtime errors. In these cases the channel | |
76 | * program will stop executing and return from zcp_eval() with an error code. | |
77 | * In place of a return value, an error message will also be returned in the | |
78 | * 'result' nvlist containing information about the error. No attempt will be | |
79 | * made to roll back or undo any changes made by the channel program before the | |
80 | * error occured. | |
81 | * | |
82 | * 3. If an error occurs inside a ZFS library call which returns an error code, | |
83 | * the error is returned to the Lua script to be handled as desired. | |
84 | * | |
85 | * In the first two cases, Lua's error-throwing mechanism is used, which | |
86 | * longjumps out of the script execution with luaL_error() and returns with the | |
87 | * error. | |
88 | * | |
89 | * See zfs-program(8) for more information on high level usage. | |
90 | */ | |
91 | ||
92 | #include <sys/lua/lua.h> | |
93 | #include <sys/lua/lualib.h> | |
94 | #include <sys/lua/lauxlib.h> | |
95 | ||
96 | #include <sys/dsl_prop.h> | |
97 | #include <sys/dsl_synctask.h> | |
98 | #include <sys/dsl_dataset.h> | |
99 | #include <sys/zcp.h> | |
100 | #include <sys/zcp_iter.h> | |
101 | #include <sys/zcp_prop.h> | |
102 | #include <sys/zcp_global.h> | |
d99a0153 CW |
103 | |
104 | #ifndef KM_NORMALPRI | |
105 | #define KM_NORMALPRI 0 | |
106 | #endif | |
107 | ||
234c91c5 CW |
108 | #define ZCP_NVLIST_MAX_DEPTH 20 |
109 | ||
d99a0153 | 110 | uint64_t zfs_lua_check_instrlimit_interval = 100; |
917f475f JG |
111 | unsigned long zfs_lua_max_instrlimit = ZCP_MAX_INSTRLIMIT; |
112 | unsigned long zfs_lua_max_memlimit = ZCP_MAX_MEMLIMIT; | |
d99a0153 | 113 | |
234c91c5 CW |
114 | /* |
115 | * Forward declarations for mutually recursive functions | |
116 | */ | |
d99a0153 CW |
117 | static int zcp_nvpair_value_to_lua(lua_State *, nvpair_t *, char *, int); |
118 | static int zcp_lua_to_nvlist_impl(lua_State *, int, nvlist_t *, const char *, | |
119 | int); | |
120 | ||
121 | typedef struct zcp_alloc_arg { | |
122 | boolean_t aa_must_succeed; | |
123 | int64_t aa_alloc_remaining; | |
124 | int64_t aa_alloc_limit; | |
125 | } zcp_alloc_arg_t; | |
126 | ||
127 | typedef struct zcp_eval_arg { | |
128 | lua_State *ea_state; | |
129 | zcp_alloc_arg_t *ea_allocargs; | |
130 | cred_t *ea_cred; | |
131 | nvlist_t *ea_outnvl; | |
132 | int ea_result; | |
133 | uint64_t ea_instrlimit; | |
134 | } zcp_eval_arg_t; | |
135 | ||
d99a0153 CW |
136 | /* |
137 | * The outer-most error callback handler for use with lua_pcall(). On | |
138 | * error Lua will call this callback with a single argument that | |
139 | * represents the error value. In most cases this will be a string | |
140 | * containing an error message, but channel programs can use Lua's | |
141 | * error() function to return arbitrary objects as errors. This callback | |
142 | * returns (on the Lua stack) the original error object along with a traceback. | |
143 | * | |
144 | * Fatal Lua errors can occur while resources are held, so we also call any | |
145 | * registered cleanup function here. | |
146 | */ | |
147 | static int | |
148 | zcp_error_handler(lua_State *state) | |
149 | { | |
150 | const char *msg; | |
151 | ||
152 | zcp_cleanup(state); | |
153 | ||
154 | VERIFY3U(1, ==, lua_gettop(state)); | |
155 | msg = lua_tostring(state, 1); | |
156 | luaL_traceback(state, state, msg, 1); | |
157 | return (1); | |
158 | } | |
159 | ||
160 | int | |
161 | zcp_argerror(lua_State *state, int narg, const char *msg, ...) | |
162 | { | |
163 | va_list alist; | |
164 | ||
165 | va_start(alist, msg); | |
166 | const char *buf = lua_pushvfstring(state, msg, alist); | |
167 | va_end(alist); | |
168 | ||
169 | return (luaL_argerror(state, narg, buf)); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Install a new cleanup function, which will be invoked with the given | |
174 | * opaque argument if a fatal error causes the Lua interpreter to longjump out | |
175 | * of a function call. | |
176 | * | |
177 | * If an error occurs, the cleanup function will be invoked exactly once and | |
178 | * then unreigstered. | |
5b72a38d SD |
179 | * |
180 | * Returns the registered cleanup handler so the caller can deregister it | |
181 | * if no error occurs. | |
d99a0153 | 182 | */ |
5b72a38d | 183 | zcp_cleanup_handler_t * |
d99a0153 CW |
184 | zcp_register_cleanup(lua_State *state, zcp_cleanup_t cleanfunc, void *cleanarg) |
185 | { | |
186 | zcp_run_info_t *ri = zcp_run_info(state); | |
d99a0153 | 187 | |
5b72a38d SD |
188 | zcp_cleanup_handler_t *zch = kmem_alloc(sizeof (*zch), KM_SLEEP); |
189 | zch->zch_cleanup_func = cleanfunc; | |
190 | zch->zch_cleanup_arg = cleanarg; | |
191 | list_insert_head(&ri->zri_cleanup_handlers, zch); | |
192 | ||
193 | return (zch); | |
d99a0153 CW |
194 | } |
195 | ||
196 | void | |
5b72a38d | 197 | zcp_deregister_cleanup(lua_State *state, zcp_cleanup_handler_t *zch) |
d99a0153 CW |
198 | { |
199 | zcp_run_info_t *ri = zcp_run_info(state); | |
5b72a38d SD |
200 | list_remove(&ri->zri_cleanup_handlers, zch); |
201 | kmem_free(zch, sizeof (*zch)); | |
d99a0153 CW |
202 | } |
203 | ||
204 | /* | |
5b72a38d SD |
205 | * Execute the currently registered cleanup handlers then free them and |
206 | * destroy the handler list. | |
d99a0153 CW |
207 | */ |
208 | void | |
209 | zcp_cleanup(lua_State *state) | |
210 | { | |
211 | zcp_run_info_t *ri = zcp_run_info(state); | |
212 | ||
5b72a38d SD |
213 | for (zcp_cleanup_handler_t *zch = |
214 | list_remove_head(&ri->zri_cleanup_handlers); zch != NULL; | |
215 | zch = list_remove_head(&ri->zri_cleanup_handlers)) { | |
216 | zch->zch_cleanup_func(zch->zch_cleanup_arg); | |
217 | kmem_free(zch, sizeof (*zch)); | |
d99a0153 CW |
218 | } |
219 | } | |
220 | ||
d99a0153 CW |
221 | /* |
222 | * Convert the lua table at the given index on the Lua stack to an nvlist | |
223 | * and return it. | |
224 | * | |
225 | * If the table can not be converted for any reason, NULL is returned and | |
226 | * an error message is pushed onto the Lua stack. | |
227 | */ | |
228 | static nvlist_t * | |
229 | zcp_table_to_nvlist(lua_State *state, int index, int depth) | |
230 | { | |
231 | nvlist_t *nvl; | |
232 | /* | |
233 | * Converting a Lua table to an nvlist with key uniqueness checking is | |
234 | * O(n^2) in the number of keys in the nvlist, which can take a long | |
235 | * time when we return a large table from a channel program. | |
236 | * Furthermore, Lua's table interface *almost* guarantees unique keys | |
237 | * on its own (details below). Therefore, we don't use fnvlist_alloc() | |
238 | * here to avoid the built-in uniqueness checking. | |
239 | * | |
240 | * The *almost* is because it's possible to have key collisions between | |
241 | * e.g. the string "1" and the number 1, or the string "true" and the | |
242 | * boolean true, so we explicitly check that when we're looking at a | |
243 | * key which is an integer / boolean or a string that can be parsed as | |
244 | * one of those types. In the worst case this could still devolve into | |
245 | * O(n^2), so we only start doing these checks on boolean/integer keys | |
246 | * once we've seen a string key which fits this weird usage pattern. | |
247 | * | |
248 | * Ultimately, we still want callers to know that the keys in this | |
249 | * nvlist are unique, so before we return this we set the nvlist's | |
250 | * flags to reflect that. | |
251 | */ | |
252 | VERIFY0(nvlist_alloc(&nvl, 0, KM_SLEEP)); | |
253 | ||
254 | /* | |
255 | * Push an empty stack slot where lua_next() will store each | |
256 | * table key. | |
257 | */ | |
258 | lua_pushnil(state); | |
259 | boolean_t saw_str_could_collide = B_FALSE; | |
260 | while (lua_next(state, index) != 0) { | |
261 | /* | |
262 | * The next key-value pair from the table at index is | |
263 | * now on the stack, with the key at stack slot -2 and | |
264 | * the value at slot -1. | |
265 | */ | |
266 | int err = 0; | |
267 | char buf[32]; | |
268 | const char *key = NULL; | |
269 | boolean_t key_could_collide = B_FALSE; | |
270 | ||
271 | switch (lua_type(state, -2)) { | |
272 | case LUA_TSTRING: | |
273 | key = lua_tostring(state, -2); | |
274 | ||
275 | /* check if this could collide with a number or bool */ | |
276 | long long tmp; | |
277 | int parselen; | |
278 | if ((sscanf(key, "%lld%n", &tmp, &parselen) > 0 && | |
279 | parselen == strlen(key)) || | |
280 | strcmp(key, "true") == 0 || | |
281 | strcmp(key, "false") == 0) { | |
282 | key_could_collide = B_TRUE; | |
283 | saw_str_could_collide = B_TRUE; | |
284 | } | |
285 | break; | |
286 | case LUA_TBOOLEAN: | |
287 | key = (lua_toboolean(state, -2) == B_TRUE ? | |
288 | "true" : "false"); | |
289 | if (saw_str_could_collide) { | |
290 | key_could_collide = B_TRUE; | |
291 | } | |
292 | break; | |
293 | case LUA_TNUMBER: | |
294 | VERIFY3U(sizeof (buf), >, | |
295 | snprintf(buf, sizeof (buf), "%lld", | |
296 | (longlong_t)lua_tonumber(state, -2))); | |
297 | key = buf; | |
298 | if (saw_str_could_collide) { | |
299 | key_could_collide = B_TRUE; | |
300 | } | |
301 | break; | |
302 | default: | |
303 | fnvlist_free(nvl); | |
304 | (void) lua_pushfstring(state, "Invalid key " | |
305 | "type '%s' in table", | |
306 | lua_typename(state, lua_type(state, -2))); | |
307 | return (NULL); | |
308 | } | |
309 | /* | |
310 | * Check for type-mismatched key collisions, and throw an error. | |
311 | */ | |
312 | if (key_could_collide && nvlist_exists(nvl, key)) { | |
313 | fnvlist_free(nvl); | |
314 | (void) lua_pushfstring(state, "Collision of " | |
315 | "key '%s' in table", key); | |
316 | return (NULL); | |
317 | } | |
318 | /* | |
319 | * Recursively convert the table value and insert into | |
320 | * the new nvlist with the parsed key. To prevent | |
321 | * stack overflow on circular or heavily nested tables, | |
322 | * we track the current nvlist depth. | |
323 | */ | |
324 | if (depth >= ZCP_NVLIST_MAX_DEPTH) { | |
325 | fnvlist_free(nvl); | |
326 | (void) lua_pushfstring(state, "Maximum table " | |
327 | "depth (%d) exceeded for table", | |
328 | ZCP_NVLIST_MAX_DEPTH); | |
329 | return (NULL); | |
330 | } | |
331 | err = zcp_lua_to_nvlist_impl(state, -1, nvl, key, | |
332 | depth + 1); | |
333 | if (err != 0) { | |
334 | fnvlist_free(nvl); | |
335 | /* | |
336 | * Error message has been pushed to the lua | |
337 | * stack by the recursive call. | |
338 | */ | |
339 | return (NULL); | |
340 | } | |
341 | /* | |
342 | * Pop the value pushed by lua_next(). | |
343 | */ | |
344 | lua_pop(state, 1); | |
345 | } | |
346 | ||
347 | /* | |
348 | * Mark the nvlist as having unique keys. This is a little ugly, but we | |
349 | * ensured above that there are no duplicate keys in the nvlist. | |
350 | */ | |
351 | nvl->nvl_nvflag |= NV_UNIQUE_NAME; | |
352 | ||
353 | return (nvl); | |
354 | } | |
355 | ||
356 | /* | |
357 | * Convert a value from the given index into the lua stack to an nvpair, adding | |
358 | * it to an nvlist with the given key. | |
359 | * | |
360 | * Values are converted as follows: | |
361 | * | |
362 | * string -> string | |
363 | * number -> int64 | |
364 | * boolean -> boolean | |
365 | * nil -> boolean (no value) | |
366 | * | |
367 | * Lua tables are converted to nvlists and then inserted. The table's keys | |
368 | * are converted to strings then used as keys in the nvlist to store each table | |
369 | * element. Keys are converted as follows: | |
370 | * | |
371 | * string -> no change | |
372 | * number -> "%lld" | |
373 | * boolean -> "true" | "false" | |
374 | * nil -> error | |
375 | * | |
376 | * In the case of a key collision, an error is thrown. | |
377 | * | |
378 | * If an error is encountered, a nonzero error code is returned, and an error | |
379 | * string will be pushed onto the Lua stack. | |
380 | */ | |
381 | static int | |
382 | zcp_lua_to_nvlist_impl(lua_State *state, int index, nvlist_t *nvl, | |
383 | const char *key, int depth) | |
384 | { | |
385 | /* | |
386 | * Verify that we have enough remaining space in the lua stack to parse | |
387 | * a key-value pair and push an error. | |
388 | */ | |
389 | if (!lua_checkstack(state, 3)) { | |
390 | (void) lua_pushstring(state, "Lua stack overflow"); | |
391 | return (1); | |
392 | } | |
393 | ||
394 | index = lua_absindex(state, index); | |
395 | ||
396 | switch (lua_type(state, index)) { | |
397 | case LUA_TNIL: | |
398 | fnvlist_add_boolean(nvl, key); | |
399 | break; | |
400 | case LUA_TBOOLEAN: | |
401 | fnvlist_add_boolean_value(nvl, key, | |
402 | lua_toboolean(state, index)); | |
403 | break; | |
404 | case LUA_TNUMBER: | |
405 | fnvlist_add_int64(nvl, key, lua_tonumber(state, index)); | |
406 | break; | |
407 | case LUA_TSTRING: | |
408 | fnvlist_add_string(nvl, key, lua_tostring(state, index)); | |
409 | break; | |
410 | case LUA_TTABLE: { | |
411 | nvlist_t *value_nvl = zcp_table_to_nvlist(state, index, depth); | |
412 | if (value_nvl == NULL) | |
413 | return (EINVAL); | |
414 | ||
415 | fnvlist_add_nvlist(nvl, key, value_nvl); | |
416 | fnvlist_free(value_nvl); | |
417 | break; | |
418 | } | |
419 | default: | |
420 | (void) lua_pushfstring(state, | |
421 | "Invalid value type '%s' for key '%s'", | |
422 | lua_typename(state, lua_type(state, index)), key); | |
423 | return (EINVAL); | |
424 | } | |
425 | ||
426 | return (0); | |
427 | } | |
428 | ||
429 | /* | |
430 | * Convert a lua value to an nvpair, adding it to an nvlist with the given key. | |
431 | */ | |
432 | void | |
433 | zcp_lua_to_nvlist(lua_State *state, int index, nvlist_t *nvl, const char *key) | |
434 | { | |
435 | /* | |
436 | * On error, zcp_lua_to_nvlist_impl pushes an error string onto the Lua | |
437 | * stack before returning with a nonzero error code. If an error is | |
438 | * returned, throw a fatal lua error with the given string. | |
439 | */ | |
440 | if (zcp_lua_to_nvlist_impl(state, index, nvl, key, 0) != 0) | |
441 | (void) lua_error(state); | |
442 | } | |
443 | ||
444 | int | |
445 | zcp_lua_to_nvlist_helper(lua_State *state) | |
446 | { | |
447 | nvlist_t *nv = (nvlist_t *)lua_touserdata(state, 2); | |
448 | const char *key = (const char *)lua_touserdata(state, 1); | |
449 | zcp_lua_to_nvlist(state, 3, nv, key); | |
450 | return (0); | |
451 | } | |
452 | ||
453 | void | |
454 | zcp_convert_return_values(lua_State *state, nvlist_t *nvl, | |
455 | const char *key, zcp_eval_arg_t *evalargs) | |
456 | { | |
457 | int err; | |
458 | lua_pushcfunction(state, zcp_lua_to_nvlist_helper); | |
459 | lua_pushlightuserdata(state, (char *)key); | |
460 | lua_pushlightuserdata(state, nvl); | |
461 | lua_pushvalue(state, 1); | |
462 | lua_remove(state, 1); | |
463 | err = lua_pcall(state, 3, 0, 0); /* zcp_lua_to_nvlist_helper */ | |
464 | if (err != 0) { | |
465 | zcp_lua_to_nvlist(state, 1, nvl, ZCP_RET_ERROR); | |
466 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
467 | } | |
468 | } | |
469 | ||
470 | /* | |
471 | * Push a Lua table representing nvl onto the stack. If it can't be | |
472 | * converted, return EINVAL, fill in errbuf, and push nothing. errbuf may | |
473 | * be specified as NULL, in which case no error string will be output. | |
474 | * | |
475 | * Most nvlists are converted as simple key->value Lua tables, but we make | |
476 | * an exception for the case where all nvlist entries are BOOLEANs (a string | |
477 | * key without a value). In Lua, a table key pointing to a value of Nil | |
478 | * (no value) is equivalent to the key not existing, so a BOOLEAN nvlist | |
479 | * entry can't be directly converted to a Lua table entry. Nvlists of entirely | |
480 | * BOOLEAN entries are frequently used to pass around lists of datasets, so for | |
481 | * convenience we check for this case, and convert it to a simple Lua array of | |
482 | * strings. | |
483 | */ | |
484 | int | |
485 | zcp_nvlist_to_lua(lua_State *state, nvlist_t *nvl, | |
486 | char *errbuf, int errbuf_len) | |
487 | { | |
488 | nvpair_t *pair; | |
489 | lua_newtable(state); | |
490 | boolean_t has_values = B_FALSE; | |
491 | /* | |
492 | * If the list doesn't have any values, just convert it to a string | |
493 | * array. | |
494 | */ | |
495 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
496 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
497 | if (nvpair_type(pair) != DATA_TYPE_BOOLEAN) { | |
498 | has_values = B_TRUE; | |
499 | break; | |
500 | } | |
501 | } | |
502 | if (!has_values) { | |
503 | int i = 1; | |
504 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
505 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
506 | (void) lua_pushinteger(state, i); | |
507 | (void) lua_pushstring(state, nvpair_name(pair)); | |
508 | (void) lua_settable(state, -3); | |
509 | i++; | |
510 | } | |
511 | } else { | |
512 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
513 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
514 | int err = zcp_nvpair_value_to_lua(state, pair, | |
515 | errbuf, errbuf_len); | |
516 | if (err != 0) { | |
517 | lua_pop(state, 1); | |
518 | return (err); | |
519 | } | |
520 | (void) lua_setfield(state, -2, nvpair_name(pair)); | |
521 | } | |
522 | } | |
523 | return (0); | |
524 | } | |
525 | ||
526 | /* | |
527 | * Push a Lua object representing the value of "pair" onto the stack. | |
528 | * | |
529 | * Only understands boolean_value, string, int64, nvlist, | |
530 | * string_array, and int64_array type values. For other | |
531 | * types, returns EINVAL, fills in errbuf, and pushes nothing. | |
532 | */ | |
533 | static int | |
534 | zcp_nvpair_value_to_lua(lua_State *state, nvpair_t *pair, | |
535 | char *errbuf, int errbuf_len) | |
536 | { | |
537 | int err = 0; | |
538 | ||
539 | if (pair == NULL) { | |
540 | lua_pushnil(state); | |
541 | return (0); | |
542 | } | |
543 | ||
544 | switch (nvpair_type(pair)) { | |
545 | case DATA_TYPE_BOOLEAN_VALUE: | |
546 | (void) lua_pushboolean(state, | |
547 | fnvpair_value_boolean_value(pair)); | |
548 | break; | |
549 | case DATA_TYPE_STRING: | |
550 | (void) lua_pushstring(state, fnvpair_value_string(pair)); | |
551 | break; | |
552 | case DATA_TYPE_INT64: | |
553 | (void) lua_pushinteger(state, fnvpair_value_int64(pair)); | |
554 | break; | |
555 | case DATA_TYPE_NVLIST: | |
556 | err = zcp_nvlist_to_lua(state, | |
557 | fnvpair_value_nvlist(pair), errbuf, errbuf_len); | |
558 | break; | |
559 | case DATA_TYPE_STRING_ARRAY: { | |
560 | char **strarr; | |
561 | uint_t nelem; | |
562 | (void) nvpair_value_string_array(pair, &strarr, &nelem); | |
563 | lua_newtable(state); | |
564 | for (int i = 0; i < nelem; i++) { | |
565 | (void) lua_pushinteger(state, i + 1); | |
566 | (void) lua_pushstring(state, strarr[i]); | |
567 | (void) lua_settable(state, -3); | |
568 | } | |
569 | break; | |
570 | } | |
571 | case DATA_TYPE_UINT64_ARRAY: { | |
572 | uint64_t *intarr; | |
573 | uint_t nelem; | |
574 | (void) nvpair_value_uint64_array(pair, &intarr, &nelem); | |
575 | lua_newtable(state); | |
576 | for (int i = 0; i < nelem; i++) { | |
577 | (void) lua_pushinteger(state, i + 1); | |
578 | (void) lua_pushinteger(state, intarr[i]); | |
579 | (void) lua_settable(state, -3); | |
580 | } | |
581 | break; | |
582 | } | |
583 | case DATA_TYPE_INT64_ARRAY: { | |
584 | int64_t *intarr; | |
585 | uint_t nelem; | |
586 | (void) nvpair_value_int64_array(pair, &intarr, &nelem); | |
587 | lua_newtable(state); | |
588 | for (int i = 0; i < nelem; i++) { | |
589 | (void) lua_pushinteger(state, i + 1); | |
590 | (void) lua_pushinteger(state, intarr[i]); | |
591 | (void) lua_settable(state, -3); | |
592 | } | |
593 | break; | |
594 | } | |
595 | default: { | |
596 | if (errbuf != NULL) { | |
597 | (void) snprintf(errbuf, errbuf_len, | |
598 | "Unhandled nvpair type %d for key '%s'", | |
599 | nvpair_type(pair), nvpair_name(pair)); | |
600 | } | |
601 | return (EINVAL); | |
602 | } | |
603 | } | |
604 | return (err); | |
605 | } | |
606 | ||
607 | int | |
608 | zcp_dataset_hold_error(lua_State *state, dsl_pool_t *dp, const char *dsname, | |
609 | int error) | |
610 | { | |
611 | if (error == ENOENT) { | |
612 | (void) zcp_argerror(state, 1, "no such dataset '%s'", dsname); | |
613 | return (0); /* not reached; zcp_argerror will longjmp */ | |
614 | } else if (error == EXDEV) { | |
615 | (void) zcp_argerror(state, 1, | |
616 | "dataset '%s' is not in the target pool '%s'", | |
617 | dsname, spa_name(dp->dp_spa)); | |
618 | return (0); /* not reached; zcp_argerror will longjmp */ | |
619 | } else if (error == EIO) { | |
620 | (void) luaL_error(state, | |
621 | "I/O error while accessing dataset '%s'", dsname); | |
622 | return (0); /* not reached; luaL_error will longjmp */ | |
623 | } else if (error != 0) { | |
624 | (void) luaL_error(state, | |
625 | "unexpected error %d while accessing dataset '%s'", | |
626 | error, dsname); | |
627 | return (0); /* not reached; luaL_error will longjmp */ | |
628 | } | |
629 | return (0); | |
630 | } | |
631 | ||
632 | /* | |
633 | * Note: will longjmp (via lua_error()) on error. | |
634 | * Assumes that the dsname is argument #1 (for error reporting purposes). | |
635 | */ | |
636 | dsl_dataset_t * | |
637 | zcp_dataset_hold(lua_State *state, dsl_pool_t *dp, const char *dsname, | |
638 | void *tag) | |
639 | { | |
640 | dsl_dataset_t *ds; | |
641 | int error = dsl_dataset_hold(dp, dsname, tag, &ds); | |
642 | (void) zcp_dataset_hold_error(state, dp, dsname, error); | |
643 | return (ds); | |
644 | } | |
645 | ||
646 | static int zcp_debug(lua_State *); | |
647 | static zcp_lib_info_t zcp_debug_info = { | |
648 | .name = "debug", | |
649 | .func = zcp_debug, | |
650 | .pargs = { | |
651 | { .za_name = "debug string", .za_lua_type = LUA_TSTRING}, | |
652 | {NULL, 0} | |
653 | }, | |
654 | .kwargs = { | |
655 | {NULL, 0} | |
656 | } | |
657 | }; | |
658 | ||
659 | static int | |
660 | zcp_debug(lua_State *state) | |
661 | { | |
662 | const char *dbgstring; | |
663 | zcp_run_info_t *ri = zcp_run_info(state); | |
664 | zcp_lib_info_t *libinfo = &zcp_debug_info; | |
665 | ||
666 | zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs); | |
667 | ||
668 | dbgstring = lua_tostring(state, 1); | |
669 | ||
670 | zfs_dbgmsg("txg %lld ZCP: %s", ri->zri_tx->tx_txg, dbgstring); | |
671 | ||
672 | return (0); | |
673 | } | |
674 | ||
675 | static int zcp_exists(lua_State *); | |
676 | static zcp_lib_info_t zcp_exists_info = { | |
677 | .name = "exists", | |
678 | .func = zcp_exists, | |
679 | .pargs = { | |
680 | { .za_name = "dataset", .za_lua_type = LUA_TSTRING}, | |
681 | {NULL, 0} | |
682 | }, | |
683 | .kwargs = { | |
684 | {NULL, 0} | |
685 | } | |
686 | }; | |
687 | ||
688 | static int | |
689 | zcp_exists(lua_State *state) | |
690 | { | |
691 | zcp_run_info_t *ri = zcp_run_info(state); | |
692 | dsl_pool_t *dp = ri->zri_pool; | |
693 | zcp_lib_info_t *libinfo = &zcp_exists_info; | |
694 | ||
695 | zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs); | |
696 | ||
697 | const char *dsname = lua_tostring(state, 1); | |
698 | ||
699 | dsl_dataset_t *ds; | |
700 | int error = dsl_dataset_hold(dp, dsname, FTAG, &ds); | |
701 | if (error == 0) { | |
702 | dsl_dataset_rele(ds, FTAG); | |
703 | lua_pushboolean(state, B_TRUE); | |
704 | } else if (error == ENOENT) { | |
705 | lua_pushboolean(state, B_FALSE); | |
706 | } else if (error == EXDEV) { | |
707 | return (luaL_error(state, "dataset '%s' is not in the " | |
708 | "target pool", dsname)); | |
709 | } else if (error == EIO) { | |
710 | return (luaL_error(state, "I/O error opening dataset '%s'", | |
711 | dsname)); | |
712 | } else if (error != 0) { | |
713 | return (luaL_error(state, "unexpected error %d", error)); | |
714 | } | |
715 | ||
475eca49 | 716 | return (1); |
d99a0153 CW |
717 | } |
718 | ||
719 | /* | |
720 | * Allocate/realloc/free a buffer for the lua interpreter. | |
721 | * | |
722 | * When nsize is 0, behaves as free() and returns NULL. | |
723 | * | |
724 | * If ptr is NULL, behaves as malloc() and returns an allocated buffer of size | |
725 | * at least nsize. | |
726 | * | |
727 | * Otherwise, behaves as realloc(), changing the allocation from osize to nsize. | |
728 | * Shrinking the buffer size never fails. | |
729 | * | |
730 | * The original allocated buffer size is stored as a uint64 at the beginning of | |
731 | * the buffer to avoid actually reallocating when shrinking a buffer, since lua | |
732 | * requires that this operation never fail. | |
733 | */ | |
734 | static void * | |
735 | zcp_lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize) | |
736 | { | |
737 | zcp_alloc_arg_t *allocargs = ud; | |
738 | int flags = (allocargs->aa_must_succeed) ? | |
739 | KM_SLEEP : (KM_NOSLEEP | KM_NORMALPRI); | |
740 | ||
741 | if (nsize == 0) { | |
742 | if (ptr != NULL) { | |
743 | int64_t *allocbuf = (int64_t *)ptr - 1; | |
744 | int64_t allocsize = *allocbuf; | |
745 | ASSERT3S(allocsize, >, 0); | |
746 | ASSERT3S(allocargs->aa_alloc_remaining + allocsize, <=, | |
747 | allocargs->aa_alloc_limit); | |
748 | allocargs->aa_alloc_remaining += allocsize; | |
749 | vmem_free(allocbuf, allocsize); | |
750 | } | |
751 | return (NULL); | |
752 | } else if (ptr == NULL) { | |
753 | int64_t *allocbuf; | |
754 | int64_t allocsize = nsize + sizeof (int64_t); | |
755 | ||
756 | if (!allocargs->aa_must_succeed && | |
757 | (allocsize <= 0 || | |
758 | allocsize > allocargs->aa_alloc_remaining)) { | |
759 | return (NULL); | |
760 | } | |
761 | ||
762 | allocbuf = vmem_alloc(allocsize, flags); | |
763 | if (allocbuf == NULL) { | |
764 | return (NULL); | |
765 | } | |
766 | allocargs->aa_alloc_remaining -= allocsize; | |
767 | ||
768 | *allocbuf = allocsize; | |
769 | return (allocbuf + 1); | |
770 | } else if (nsize <= osize) { | |
771 | /* | |
772 | * If shrinking the buffer, lua requires that the reallocation | |
773 | * never fail. | |
774 | */ | |
775 | return (ptr); | |
776 | } else { | |
777 | ASSERT3U(nsize, >, osize); | |
778 | ||
779 | uint64_t *luabuf = zcp_lua_alloc(ud, NULL, 0, nsize); | |
780 | if (luabuf == NULL) { | |
781 | return (NULL); | |
782 | } | |
783 | (void) memcpy(luabuf, ptr, osize); | |
784 | VERIFY3P(zcp_lua_alloc(ud, ptr, osize, 0), ==, NULL); | |
785 | return (luabuf); | |
786 | } | |
787 | } | |
788 | ||
789 | /* ARGSUSED */ | |
790 | static void | |
791 | zcp_lua_counthook(lua_State *state, lua_Debug *ar) | |
792 | { | |
793 | /* | |
794 | * If we're called, check how many instructions the channel program has | |
795 | * executed so far, and compare against the limit. | |
796 | */ | |
797 | lua_getfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
798 | zcp_run_info_t *ri = lua_touserdata(state, -1); | |
799 | ||
800 | ri->zri_curinstrs += zfs_lua_check_instrlimit_interval; | |
801 | if (ri->zri_maxinstrs != 0 && ri->zri_curinstrs > ri->zri_maxinstrs) { | |
802 | ri->zri_timed_out = B_TRUE; | |
803 | (void) lua_pushstring(state, | |
804 | "Channel program timed out."); | |
805 | (void) lua_error(state); | |
806 | } | |
807 | } | |
808 | ||
809 | static int | |
810 | zcp_panic_cb(lua_State *state) | |
811 | { | |
812 | panic("unprotected error in call to Lua API (%s)\n", | |
813 | lua_tostring(state, -1)); | |
814 | return (0); | |
815 | } | |
816 | ||
817 | static void | |
5b72a38d | 818 | zcp_eval_impl(dmu_tx_t *tx, boolean_t sync, zcp_eval_arg_t *evalargs) |
d99a0153 CW |
819 | { |
820 | int err; | |
821 | zcp_run_info_t ri; | |
d99a0153 CW |
822 | lua_State *state = evalargs->ea_state; |
823 | ||
d99a0153 CW |
824 | VERIFY3U(3, ==, lua_gettop(state)); |
825 | ||
826 | /* | |
827 | * Store the zcp_run_info_t struct for this run in the Lua registry. | |
828 | * Registry entries are not directly accessible by the Lua scripts but | |
829 | * can be accessed by our callbacks. | |
830 | */ | |
831 | ri.zri_space_used = 0; | |
832 | ri.zri_pool = dmu_tx_pool(tx); | |
833 | ri.zri_cred = evalargs->ea_cred; | |
834 | ri.zri_tx = tx; | |
835 | ri.zri_timed_out = B_FALSE; | |
5b72a38d SD |
836 | ri.zri_sync = sync; |
837 | list_create(&ri.zri_cleanup_handlers, sizeof (zcp_cleanup_handler_t), | |
838 | offsetof(zcp_cleanup_handler_t, zch_node)); | |
d99a0153 CW |
839 | ri.zri_curinstrs = 0; |
840 | ri.zri_maxinstrs = evalargs->ea_instrlimit; | |
841 | ||
842 | lua_pushlightuserdata(state, &ri); | |
843 | lua_setfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
844 | VERIFY3U(3, ==, lua_gettop(state)); | |
845 | ||
846 | /* | |
847 | * Tell the Lua interpreter to call our handler every count | |
848 | * instructions. Channel programs that execute too many instructions | |
849 | * should die with ETIME. | |
850 | */ | |
851 | (void) lua_sethook(state, zcp_lua_counthook, LUA_MASKCOUNT, | |
852 | zfs_lua_check_instrlimit_interval); | |
853 | ||
854 | /* | |
855 | * Tell the Lua memory allocator to stop using KM_SLEEP before handing | |
856 | * off control to the channel program. Channel programs that use too | |
857 | * much memory should die with ENOSPC. | |
858 | */ | |
859 | evalargs->ea_allocargs->aa_must_succeed = B_FALSE; | |
860 | ||
861 | /* | |
862 | * Call the Lua function that open-context passed us. This pops the | |
863 | * function and its input from the stack and pushes any return | |
864 | * or error values. | |
865 | */ | |
866 | err = lua_pcall(state, 1, LUA_MULTRET, 1); | |
867 | ||
868 | /* | |
869 | * Let Lua use KM_SLEEP while we interpret the return values. | |
870 | */ | |
871 | evalargs->ea_allocargs->aa_must_succeed = B_TRUE; | |
872 | ||
873 | /* | |
874 | * Remove the error handler callback from the stack. At this point, | |
5b72a38d SD |
875 | * there shouldn't be any cleanup handler registered in the handler |
876 | * list (zri_cleanup_handlers), regardless of whether it ran or not. | |
d99a0153 | 877 | */ |
5b72a38d | 878 | list_destroy(&ri.zri_cleanup_handlers); |
d99a0153 CW |
879 | lua_remove(state, 1); |
880 | ||
881 | switch (err) { | |
882 | case LUA_OK: { | |
883 | /* | |
884 | * Lua supports returning multiple values in a single return | |
885 | * statement. Return values will have been pushed onto the | |
886 | * stack: | |
887 | * 1: Return value 1 | |
888 | * 2: Return value 2 | |
889 | * 3: etc... | |
890 | * To simplify the process of retrieving a return value from a | |
891 | * channel program, we disallow returning more than one value | |
892 | * to ZFS from the Lua script, yielding a singleton return | |
893 | * nvlist of the form { "return": Return value 1 }. | |
894 | */ | |
895 | int return_count = lua_gettop(state); | |
896 | ||
897 | if (return_count == 1) { | |
898 | evalargs->ea_result = 0; | |
899 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
900 | ZCP_RET_RETURN, evalargs); | |
901 | } else if (return_count > 1) { | |
902 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
903 | (void) lua_pushfstring(state, "Multiple return " | |
904 | "values not supported"); | |
905 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
906 | ZCP_RET_ERROR, evalargs); | |
907 | } | |
908 | break; | |
909 | } | |
910 | case LUA_ERRRUN: | |
911 | case LUA_ERRGCMM: { | |
912 | /* | |
913 | * The channel program encountered a fatal error within the | |
914 | * script, such as failing an assertion, or calling a function | |
915 | * with incompatible arguments. The error value and the | |
916 | * traceback generated by zcp_error_handler() should be on the | |
917 | * stack. | |
918 | */ | |
919 | VERIFY3U(1, ==, lua_gettop(state)); | |
920 | if (ri.zri_timed_out) { | |
921 | evalargs->ea_result = SET_ERROR(ETIME); | |
922 | } else { | |
923 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
924 | } | |
925 | ||
926 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
927 | ZCP_RET_ERROR, evalargs); | |
928 | ||
929 | if (evalargs->ea_result == ETIME && | |
930 | evalargs->ea_outnvl != NULL) { | |
931 | (void) nvlist_add_uint64(evalargs->ea_outnvl, | |
932 | ZCP_ARG_INSTRLIMIT, ri.zri_curinstrs); | |
933 | } | |
934 | break; | |
935 | } | |
936 | case LUA_ERRERR: { | |
937 | /* | |
938 | * The channel program encountered a fatal error within the | |
939 | * script, and we encountered another error while trying to | |
940 | * compute the traceback in zcp_error_handler(). We can only | |
941 | * return the error message. | |
942 | */ | |
943 | VERIFY3U(1, ==, lua_gettop(state)); | |
944 | if (ri.zri_timed_out) { | |
945 | evalargs->ea_result = SET_ERROR(ETIME); | |
946 | } else { | |
947 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
948 | } | |
949 | ||
950 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
951 | ZCP_RET_ERROR, evalargs); | |
952 | break; | |
953 | } | |
954 | case LUA_ERRMEM: | |
955 | /* | |
956 | * Lua ran out of memory while running the channel program. | |
957 | * There's not much we can do. | |
958 | */ | |
959 | evalargs->ea_result = SET_ERROR(ENOSPC); | |
960 | break; | |
961 | default: | |
962 | VERIFY0(err); | |
963 | } | |
964 | } | |
965 | ||
5b72a38d SD |
966 | static void |
967 | zcp_pool_error(zcp_eval_arg_t *evalargs, const char *poolname) | |
968 | { | |
969 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
970 | (void) lua_pushfstring(evalargs->ea_state, "Could not open pool: %s", | |
971 | poolname); | |
972 | zcp_convert_return_values(evalargs->ea_state, evalargs->ea_outnvl, | |
973 | ZCP_RET_ERROR, evalargs); | |
974 | ||
975 | } | |
976 | ||
977 | static void | |
978 | zcp_eval_sync(void *arg, dmu_tx_t *tx) | |
979 | { | |
980 | zcp_eval_arg_t *evalargs = arg; | |
981 | ||
982 | /* | |
983 | * Open context should have setup the stack to contain: | |
984 | * 1: Error handler callback | |
985 | * 2: Script to run (converted to a Lua function) | |
986 | * 3: nvlist input to function (converted to Lua table or nil) | |
987 | */ | |
988 | VERIFY3U(3, ==, lua_gettop(evalargs->ea_state)); | |
989 | ||
990 | zcp_eval_impl(tx, B_TRUE, evalargs); | |
991 | } | |
992 | ||
993 | static void | |
994 | zcp_eval_open(zcp_eval_arg_t *evalargs, const char *poolname) | |
995 | { | |
996 | ||
997 | int error; | |
998 | dsl_pool_t *dp; | |
999 | dmu_tx_t *tx; | |
1000 | ||
1001 | /* | |
1002 | * See comment from the same assertion in zcp_eval_sync(). | |
1003 | */ | |
1004 | VERIFY3U(3, ==, lua_gettop(evalargs->ea_state)); | |
1005 | ||
1006 | error = dsl_pool_hold(poolname, FTAG, &dp); | |
1007 | if (error != 0) { | |
1008 | zcp_pool_error(evalargs, poolname); | |
1009 | return; | |
1010 | } | |
1011 | ||
1012 | /* | |
1013 | * As we are running in open-context, we have no transaction associated | |
1014 | * with the channel program. At the same time, functions from the | |
1015 | * zfs.check submodule need to be associated with a transaction as | |
1016 | * they are basically dry-runs of their counterparts in the zfs.sync | |
1017 | * submodule. These functions should be able to run in open-context. | |
1018 | * Therefore we create a new transaction that we later abort once | |
1019 | * the channel program has been evaluated. | |
1020 | */ | |
1021 | tx = dmu_tx_create_dd(dp->dp_mos_dir); | |
1022 | ||
1023 | zcp_eval_impl(tx, B_FALSE, evalargs); | |
1024 | ||
1025 | dmu_tx_abort(tx); | |
1026 | ||
1027 | dsl_pool_rele(dp, FTAG); | |
1028 | } | |
1029 | ||
d99a0153 | 1030 | int |
5b72a38d SD |
1031 | zcp_eval(const char *poolname, const char *program, boolean_t sync, |
1032 | uint64_t instrlimit, uint64_t memlimit, nvpair_t *nvarg, nvlist_t *outnvl) | |
d99a0153 CW |
1033 | { |
1034 | int err; | |
1035 | lua_State *state; | |
1036 | zcp_eval_arg_t evalargs; | |
1037 | ||
1038 | if (instrlimit > zfs_lua_max_instrlimit) | |
1039 | return (SET_ERROR(EINVAL)); | |
1040 | if (memlimit == 0 || memlimit > zfs_lua_max_memlimit) | |
1041 | return (SET_ERROR(EINVAL)); | |
1042 | ||
1043 | zcp_alloc_arg_t allocargs = { | |
1044 | .aa_must_succeed = B_TRUE, | |
1045 | .aa_alloc_remaining = (int64_t)memlimit, | |
1046 | .aa_alloc_limit = (int64_t)memlimit, | |
1047 | }; | |
1048 | ||
1049 | /* | |
1050 | * Creates a Lua state with a memory allocator that uses KM_SLEEP. | |
1051 | * This should never fail. | |
1052 | */ | |
1053 | state = lua_newstate(zcp_lua_alloc, &allocargs); | |
1054 | VERIFY(state != NULL); | |
1055 | (void) lua_atpanic(state, zcp_panic_cb); | |
1056 | ||
1057 | /* | |
1058 | * Load core Lua libraries we want access to. | |
1059 | */ | |
1060 | VERIFY3U(1, ==, luaopen_base(state)); | |
1061 | lua_pop(state, 1); | |
1062 | VERIFY3U(1, ==, luaopen_coroutine(state)); | |
1063 | lua_setglobal(state, LUA_COLIBNAME); | |
1064 | VERIFY0(lua_gettop(state)); | |
1065 | VERIFY3U(1, ==, luaopen_string(state)); | |
1066 | lua_setglobal(state, LUA_STRLIBNAME); | |
1067 | VERIFY0(lua_gettop(state)); | |
1068 | VERIFY3U(1, ==, luaopen_table(state)); | |
1069 | lua_setglobal(state, LUA_TABLIBNAME); | |
1070 | VERIFY0(lua_gettop(state)); | |
1071 | ||
1072 | /* | |
1073 | * Load globally visible variables such as errno aliases. | |
1074 | */ | |
1075 | zcp_load_globals(state); | |
1076 | VERIFY0(lua_gettop(state)); | |
1077 | ||
1078 | /* | |
1079 | * Load ZFS-specific modules. | |
1080 | */ | |
1081 | lua_newtable(state); | |
1082 | VERIFY3U(1, ==, zcp_load_list_lib(state)); | |
1083 | lua_setfield(state, -2, "list"); | |
1084 | VERIFY3U(1, ==, zcp_load_synctask_lib(state, B_FALSE)); | |
1085 | lua_setfield(state, -2, "check"); | |
1086 | VERIFY3U(1, ==, zcp_load_synctask_lib(state, B_TRUE)); | |
1087 | lua_setfield(state, -2, "sync"); | |
1088 | VERIFY3U(1, ==, zcp_load_get_lib(state)); | |
1089 | lua_pushcclosure(state, zcp_debug_info.func, 0); | |
1090 | lua_setfield(state, -2, zcp_debug_info.name); | |
1091 | lua_pushcclosure(state, zcp_exists_info.func, 0); | |
1092 | lua_setfield(state, -2, zcp_exists_info.name); | |
1093 | lua_setglobal(state, "zfs"); | |
1094 | VERIFY0(lua_gettop(state)); | |
1095 | ||
1096 | /* | |
1097 | * Push the error-callback that calculates Lua stack traces on | |
1098 | * unexpected failures. | |
1099 | */ | |
1100 | lua_pushcfunction(state, zcp_error_handler); | |
1101 | VERIFY3U(1, ==, lua_gettop(state)); | |
1102 | ||
1103 | /* | |
1104 | * Load the actual script as a function onto the stack as text ("t"). | |
1105 | * The only valid error condition is a syntax error in the script. | |
1106 | * ERRMEM should not be possible because our allocator is using | |
1107 | * KM_SLEEP. ERRGCMM should not be possible because we have not added | |
1108 | * any objects with __gc metamethods to the interpreter that could | |
1109 | * fail. | |
1110 | */ | |
1111 | err = luaL_loadbufferx(state, program, strlen(program), | |
1112 | "channel program", "t"); | |
1113 | if (err == LUA_ERRSYNTAX) { | |
1114 | fnvlist_add_string(outnvl, ZCP_RET_ERROR, | |
1115 | lua_tostring(state, -1)); | |
1116 | lua_close(state); | |
1117 | return (SET_ERROR(EINVAL)); | |
1118 | } | |
1119 | VERIFY0(err); | |
1120 | VERIFY3U(2, ==, lua_gettop(state)); | |
1121 | ||
1122 | /* | |
1123 | * Convert the input nvlist to a Lua object and put it on top of the | |
1124 | * stack. | |
1125 | */ | |
1126 | char errmsg[128]; | |
1127 | err = zcp_nvpair_value_to_lua(state, nvarg, | |
1128 | errmsg, sizeof (errmsg)); | |
1129 | if (err != 0) { | |
1130 | fnvlist_add_string(outnvl, ZCP_RET_ERROR, errmsg); | |
1131 | lua_close(state); | |
1132 | return (SET_ERROR(EINVAL)); | |
1133 | } | |
1134 | VERIFY3U(3, ==, lua_gettop(state)); | |
1135 | ||
1136 | evalargs.ea_state = state; | |
1137 | evalargs.ea_allocargs = &allocargs; | |
1138 | evalargs.ea_instrlimit = instrlimit; | |
1139 | evalargs.ea_cred = CRED(); | |
1140 | evalargs.ea_outnvl = outnvl; | |
1141 | evalargs.ea_result = 0; | |
1142 | ||
5b72a38d SD |
1143 | if (sync) { |
1144 | err = dsl_sync_task(poolname, NULL, | |
1145 | zcp_eval_sync, &evalargs, 0, ZFS_SPACE_CHECK_NONE); | |
1146 | if (err != 0) | |
1147 | zcp_pool_error(&evalargs, poolname); | |
1148 | } else { | |
1149 | zcp_eval_open(&evalargs, poolname); | |
1150 | } | |
d99a0153 CW |
1151 | lua_close(state); |
1152 | ||
1153 | return (evalargs.ea_result); | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * Retrieve metadata about the currently running channel program. | |
1158 | */ | |
1159 | zcp_run_info_t * | |
1160 | zcp_run_info(lua_State *state) | |
1161 | { | |
1162 | zcp_run_info_t *ri; | |
1163 | ||
1164 | lua_getfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
1165 | ri = lua_touserdata(state, -1); | |
1166 | lua_pop(state, 1); | |
1167 | return (ri); | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | * Argument Parsing | |
1172 | * ================ | |
1173 | * | |
1174 | * The Lua language allows methods to be called with any number | |
1175 | * of arguments of any type. When calling back into ZFS we need to sanitize | |
1176 | * arguments from channel programs to make sure unexpected arguments or | |
1177 | * arguments of the wrong type result in clear error messages. To do this | |
1178 | * in a uniform way all callbacks from channel programs should use the | |
1179 | * zcp_parse_args() function to interpret inputs. | |
1180 | * | |
1181 | * Positional vs Keyword Arguments | |
1182 | * =============================== | |
1183 | * | |
1184 | * Every callback function takes a fixed set of required positional arguments | |
1185 | * and optional keyword arguments. For example, the destroy function takes | |
1186 | * a single positional string argument (the name of the dataset to destroy) | |
1187 | * and an optional "defer" keyword boolean argument. When calling lua functions | |
1188 | * with parentheses, only positional arguments can be used: | |
1189 | * | |
1190 | * zfs.sync.snapshot("rpool@snap") | |
1191 | * | |
1192 | * To use keyword arguments functions should be called with a single argument | |
1193 | * that is a lua table containing mappings of integer -> positional arguments | |
1194 | * and string -> keyword arguments: | |
1195 | * | |
1196 | * zfs.sync.snapshot({1="rpool@snap", defer=true}) | |
1197 | * | |
1198 | * The lua language allows curly braces to be used in place of parenthesis as | |
1199 | * syntactic sugar for this calling convention: | |
1200 | * | |
1201 | * zfs.sync.snapshot{"rpool@snap", defer=true} | |
1202 | */ | |
1203 | ||
1204 | /* | |
1205 | * Throw an error and print the given arguments. If there are too many | |
1206 | * arguments to fit in the output buffer, only the error format string is | |
1207 | * output. | |
1208 | */ | |
1209 | static void | |
1210 | zcp_args_error(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1211 | const zcp_arg_t *kwargs, const char *fmt, ...) | |
1212 | { | |
1213 | int i; | |
1214 | char errmsg[512]; | |
1215 | size_t len = sizeof (errmsg); | |
1216 | size_t msglen = 0; | |
1217 | va_list argp; | |
1218 | ||
1219 | va_start(argp, fmt); | |
1220 | VERIFY3U(len, >, vsnprintf(errmsg, len, fmt, argp)); | |
1221 | va_end(argp); | |
1222 | ||
1223 | /* | |
1224 | * Calculate the total length of the final string, including extra | |
1225 | * formatting characters. If the argument dump would be too large, | |
1226 | * only print the error string. | |
1227 | */ | |
1228 | msglen = strlen(errmsg); | |
1229 | msglen += strlen(fname) + 4; /* : + {} + null terminator */ | |
1230 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1231 | msglen += strlen(pargs[i].za_name); | |
1232 | msglen += strlen(lua_typename(state, pargs[i].za_lua_type)); | |
1233 | if (pargs[i + 1].za_name != NULL || kwargs[0].za_name != NULL) | |
1234 | msglen += 5; /* < + ( + )> + , */ | |
1235 | else | |
1236 | msglen += 4; /* < + ( + )> */ | |
1237 | } | |
1238 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1239 | msglen += strlen(kwargs[i].za_name); | |
1240 | msglen += strlen(lua_typename(state, kwargs[i].za_lua_type)); | |
1241 | if (kwargs[i + 1].za_name != NULL) | |
1242 | msglen += 4; /* =( + ) + , */ | |
1243 | else | |
1244 | msglen += 3; /* =( + ) */ | |
1245 | } | |
1246 | ||
1247 | if (msglen >= len) | |
1248 | (void) luaL_error(state, errmsg); | |
1249 | ||
1250 | VERIFY3U(len, >, strlcat(errmsg, ": ", len)); | |
1251 | VERIFY3U(len, >, strlcat(errmsg, fname, len)); | |
1252 | VERIFY3U(len, >, strlcat(errmsg, "{", len)); | |
1253 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1254 | VERIFY3U(len, >, strlcat(errmsg, "<", len)); | |
1255 | VERIFY3U(len, >, strlcat(errmsg, pargs[i].za_name, len)); | |
1256 | VERIFY3U(len, >, strlcat(errmsg, "(", len)); | |
1257 | VERIFY3U(len, >, strlcat(errmsg, | |
1258 | lua_typename(state, pargs[i].za_lua_type), len)); | |
1259 | VERIFY3U(len, >, strlcat(errmsg, ")>", len)); | |
1260 | if (pargs[i + 1].za_name != NULL || kwargs[0].za_name != NULL) { | |
1261 | VERIFY3U(len, >, strlcat(errmsg, ", ", len)); | |
1262 | } | |
1263 | } | |
1264 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1265 | VERIFY3U(len, >, strlcat(errmsg, kwargs[i].za_name, len)); | |
1266 | VERIFY3U(len, >, strlcat(errmsg, "=(", len)); | |
1267 | VERIFY3U(len, >, strlcat(errmsg, | |
1268 | lua_typename(state, kwargs[i].za_lua_type), len)); | |
1269 | VERIFY3U(len, >, strlcat(errmsg, ")", len)); | |
1270 | if (kwargs[i + 1].za_name != NULL) { | |
1271 | VERIFY3U(len, >, strlcat(errmsg, ", ", len)); | |
1272 | } | |
1273 | } | |
1274 | VERIFY3U(len, >, strlcat(errmsg, "}", len)); | |
1275 | ||
1276 | (void) luaL_error(state, errmsg); | |
1277 | panic("unreachable code"); | |
1278 | } | |
1279 | ||
1280 | static void | |
1281 | zcp_parse_table_args(lua_State *state, const char *fname, | |
1282 | const zcp_arg_t *pargs, const zcp_arg_t *kwargs) | |
1283 | { | |
1284 | int i; | |
1285 | int type; | |
1286 | ||
1287 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1288 | /* | |
1289 | * Check the table for this positional argument, leaving it | |
1290 | * on the top of the stack once we finish validating it. | |
1291 | */ | |
1292 | lua_pushinteger(state, i + 1); | |
1293 | lua_gettable(state, 1); | |
1294 | ||
1295 | type = lua_type(state, -1); | |
1296 | if (type == LUA_TNIL) { | |
1297 | zcp_args_error(state, fname, pargs, kwargs, | |
1298 | "too few arguments"); | |
1299 | panic("unreachable code"); | |
1300 | } else if (type != pargs[i].za_lua_type) { | |
1301 | zcp_args_error(state, fname, pargs, kwargs, | |
1302 | "arg %d wrong type (is '%s', expected '%s')", | |
1303 | i + 1, lua_typename(state, type), | |
1304 | lua_typename(state, pargs[i].za_lua_type)); | |
1305 | panic("unreachable code"); | |
1306 | } | |
1307 | ||
1308 | /* | |
1309 | * Remove the positional argument from the table. | |
1310 | */ | |
1311 | lua_pushinteger(state, i + 1); | |
1312 | lua_pushnil(state); | |
1313 | lua_settable(state, 1); | |
1314 | } | |
1315 | ||
1316 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1317 | /* | |
1318 | * Check the table for this keyword argument, which may be | |
1319 | * nil if it was omitted. Leave the value on the top of | |
1320 | * the stack after validating it. | |
1321 | */ | |
1322 | lua_getfield(state, 1, kwargs[i].za_name); | |
1323 | ||
1324 | type = lua_type(state, -1); | |
1325 | if (type != LUA_TNIL && type != kwargs[i].za_lua_type) { | |
1326 | zcp_args_error(state, fname, pargs, kwargs, | |
1327 | "kwarg '%s' wrong type (is '%s', expected '%s')", | |
1328 | kwargs[i].za_name, lua_typename(state, type), | |
1329 | lua_typename(state, kwargs[i].za_lua_type)); | |
1330 | panic("unreachable code"); | |
1331 | } | |
1332 | ||
1333 | /* | |
1334 | * Remove the keyword argument from the table. | |
1335 | */ | |
1336 | lua_pushnil(state); | |
1337 | lua_setfield(state, 1, kwargs[i].za_name); | |
1338 | } | |
1339 | ||
1340 | /* | |
1341 | * Any entries remaining in the table are invalid inputs, print | |
1342 | * an error message based on what the entry is. | |
1343 | */ | |
1344 | lua_pushnil(state); | |
1345 | if (lua_next(state, 1)) { | |
1346 | if (lua_isnumber(state, -2) && lua_tointeger(state, -2) > 0) { | |
1347 | zcp_args_error(state, fname, pargs, kwargs, | |
1348 | "too many positional arguments"); | |
1349 | } else if (lua_isstring(state, -2)) { | |
1350 | zcp_args_error(state, fname, pargs, kwargs, | |
1351 | "invalid kwarg '%s'", lua_tostring(state, -2)); | |
1352 | } else { | |
1353 | zcp_args_error(state, fname, pargs, kwargs, | |
1354 | "kwarg keys must be strings"); | |
1355 | } | |
1356 | panic("unreachable code"); | |
1357 | } | |
1358 | ||
1359 | lua_remove(state, 1); | |
1360 | } | |
1361 | ||
1362 | static void | |
1363 | zcp_parse_pos_args(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1364 | const zcp_arg_t *kwargs) | |
1365 | { | |
1366 | int i; | |
1367 | int type; | |
1368 | ||
1369 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1370 | type = lua_type(state, i + 1); | |
1371 | if (type == LUA_TNONE) { | |
1372 | zcp_args_error(state, fname, pargs, kwargs, | |
1373 | "too few arguments"); | |
1374 | panic("unreachable code"); | |
1375 | } else if (type != pargs[i].za_lua_type) { | |
1376 | zcp_args_error(state, fname, pargs, kwargs, | |
1377 | "arg %d wrong type (is '%s', expected '%s')", | |
1378 | i + 1, lua_typename(state, type), | |
1379 | lua_typename(state, pargs[i].za_lua_type)); | |
1380 | panic("unreachable code"); | |
1381 | } | |
1382 | } | |
1383 | if (lua_gettop(state) != i) { | |
1384 | zcp_args_error(state, fname, pargs, kwargs, | |
1385 | "too many positional arguments"); | |
1386 | panic("unreachable code"); | |
1387 | } | |
1388 | ||
1389 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1390 | lua_pushnil(state); | |
1391 | } | |
1392 | } | |
1393 | ||
1394 | /* | |
1395 | * Checks the current Lua stack against an expected set of positional and | |
1396 | * keyword arguments. If the stack does not match the expected arguments | |
1397 | * aborts the current channel program with a useful error message, otherwise | |
1398 | * it re-arranges the stack so that it contains the positional arguments | |
1399 | * followed by the keyword argument values in declaration order. Any missing | |
1400 | * keyword argument will be represented by a nil value on the stack. | |
1401 | * | |
1402 | * If the stack contains exactly one argument of type LUA_TTABLE the curly | |
1403 | * braces calling convention is assumed, otherwise the stack is parsed for | |
1404 | * positional arguments only. | |
1405 | * | |
1406 | * This function should be used by every function callback. It should be called | |
1407 | * before the callback manipulates the Lua stack as it assumes the stack | |
1408 | * represents the function arguments. | |
1409 | */ | |
1410 | void | |
1411 | zcp_parse_args(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1412 | const zcp_arg_t *kwargs) | |
1413 | { | |
1414 | if (lua_gettop(state) == 1 && lua_istable(state, 1)) { | |
1415 | zcp_parse_table_args(state, fname, pargs, kwargs); | |
1416 | } else { | |
1417 | zcp_parse_pos_args(state, fname, pargs, kwargs); | |
1418 | } | |
1419 | } | |
917f475f JG |
1420 | |
1421 | #if defined(_KERNEL) | |
1422 | /* BEGIN CSTYLED */ | |
1423 | module_param(zfs_lua_max_instrlimit, ulong, 0644); | |
1424 | MODULE_PARM_DESC(zfs_lua_max_instrlimit, | |
1425 | "Max instruction limit that can be specified for a channel program"); | |
1426 | ||
1427 | module_param(zfs_lua_max_memlimit, ulong, 0644); | |
1428 | MODULE_PARM_DESC(zfs_lua_max_memlimit, | |
1429 | "Max memory limit that can be specified for a channel program"); | |
1430 | /* END CSTYLED */ | |
1431 | #endif |