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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 | /* | |
234c91c5 | 17 | * Copyright (c) 2016, 2017 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> | |
103 | #include <util/sscanf.h> | |
104 | ||
105 | #ifndef KM_NORMALPRI | |
106 | #define KM_NORMALPRI 0 | |
107 | #endif | |
108 | ||
234c91c5 CW |
109 | #define ZCP_NVLIST_MAX_DEPTH 20 |
110 | ||
d99a0153 CW |
111 | uint64_t zfs_lua_check_instrlimit_interval = 100; |
112 | uint64_t zfs_lua_max_instrlimit = ZCP_MAX_INSTRLIMIT; | |
113 | uint64_t zfs_lua_max_memlimit = ZCP_MAX_MEMLIMIT; | |
114 | ||
234c91c5 CW |
115 | /* |
116 | * Forward declarations for mutually recursive functions | |
117 | */ | |
d99a0153 CW |
118 | static int zcp_nvpair_value_to_lua(lua_State *, nvpair_t *, char *, int); |
119 | static int zcp_lua_to_nvlist_impl(lua_State *, int, nvlist_t *, const char *, | |
120 | int); | |
121 | ||
122 | typedef struct zcp_alloc_arg { | |
123 | boolean_t aa_must_succeed; | |
124 | int64_t aa_alloc_remaining; | |
125 | int64_t aa_alloc_limit; | |
126 | } zcp_alloc_arg_t; | |
127 | ||
128 | typedef struct zcp_eval_arg { | |
129 | lua_State *ea_state; | |
130 | zcp_alloc_arg_t *ea_allocargs; | |
131 | cred_t *ea_cred; | |
132 | nvlist_t *ea_outnvl; | |
133 | int ea_result; | |
134 | uint64_t ea_instrlimit; | |
135 | } zcp_eval_arg_t; | |
136 | ||
d99a0153 CW |
137 | /* |
138 | * The outer-most error callback handler for use with lua_pcall(). On | |
139 | * error Lua will call this callback with a single argument that | |
140 | * represents the error value. In most cases this will be a string | |
141 | * containing an error message, but channel programs can use Lua's | |
142 | * error() function to return arbitrary objects as errors. This callback | |
143 | * returns (on the Lua stack) the original error object along with a traceback. | |
144 | * | |
145 | * Fatal Lua errors can occur while resources are held, so we also call any | |
146 | * registered cleanup function here. | |
147 | */ | |
148 | static int | |
149 | zcp_error_handler(lua_State *state) | |
150 | { | |
151 | const char *msg; | |
152 | ||
153 | zcp_cleanup(state); | |
154 | ||
155 | VERIFY3U(1, ==, lua_gettop(state)); | |
156 | msg = lua_tostring(state, 1); | |
157 | luaL_traceback(state, state, msg, 1); | |
158 | return (1); | |
159 | } | |
160 | ||
161 | int | |
162 | zcp_argerror(lua_State *state, int narg, const char *msg, ...) | |
163 | { | |
164 | va_list alist; | |
165 | ||
166 | va_start(alist, msg); | |
167 | const char *buf = lua_pushvfstring(state, msg, alist); | |
168 | va_end(alist); | |
169 | ||
170 | return (luaL_argerror(state, narg, buf)); | |
171 | } | |
172 | ||
173 | /* | |
174 | * Install a new cleanup function, which will be invoked with the given | |
175 | * opaque argument if a fatal error causes the Lua interpreter to longjump out | |
176 | * of a function call. | |
177 | * | |
178 | * If an error occurs, the cleanup function will be invoked exactly once and | |
179 | * then unreigstered. | |
5b72a38d SD |
180 | * |
181 | * Returns the registered cleanup handler so the caller can deregister it | |
182 | * if no error occurs. | |
d99a0153 | 183 | */ |
5b72a38d | 184 | zcp_cleanup_handler_t * |
d99a0153 CW |
185 | zcp_register_cleanup(lua_State *state, zcp_cleanup_t cleanfunc, void *cleanarg) |
186 | { | |
187 | zcp_run_info_t *ri = zcp_run_info(state); | |
d99a0153 | 188 | |
5b72a38d SD |
189 | zcp_cleanup_handler_t *zch = kmem_alloc(sizeof (*zch), KM_SLEEP); |
190 | zch->zch_cleanup_func = cleanfunc; | |
191 | zch->zch_cleanup_arg = cleanarg; | |
192 | list_insert_head(&ri->zri_cleanup_handlers, zch); | |
193 | ||
194 | return (zch); | |
d99a0153 CW |
195 | } |
196 | ||
197 | void | |
5b72a38d | 198 | zcp_deregister_cleanup(lua_State *state, zcp_cleanup_handler_t *zch) |
d99a0153 CW |
199 | { |
200 | zcp_run_info_t *ri = zcp_run_info(state); | |
5b72a38d SD |
201 | list_remove(&ri->zri_cleanup_handlers, zch); |
202 | kmem_free(zch, sizeof (*zch)); | |
d99a0153 CW |
203 | } |
204 | ||
205 | /* | |
5b72a38d SD |
206 | * Execute the currently registered cleanup handlers then free them and |
207 | * destroy the handler list. | |
d99a0153 CW |
208 | */ |
209 | void | |
210 | zcp_cleanup(lua_State *state) | |
211 | { | |
212 | zcp_run_info_t *ri = zcp_run_info(state); | |
213 | ||
5b72a38d SD |
214 | for (zcp_cleanup_handler_t *zch = |
215 | list_remove_head(&ri->zri_cleanup_handlers); zch != NULL; | |
216 | zch = list_remove_head(&ri->zri_cleanup_handlers)) { | |
217 | zch->zch_cleanup_func(zch->zch_cleanup_arg); | |
218 | kmem_free(zch, sizeof (*zch)); | |
d99a0153 CW |
219 | } |
220 | } | |
221 | ||
d99a0153 CW |
222 | /* |
223 | * Convert the lua table at the given index on the Lua stack to an nvlist | |
224 | * and return it. | |
225 | * | |
226 | * If the table can not be converted for any reason, NULL is returned and | |
227 | * an error message is pushed onto the Lua stack. | |
228 | */ | |
229 | static nvlist_t * | |
230 | zcp_table_to_nvlist(lua_State *state, int index, int depth) | |
231 | { | |
232 | nvlist_t *nvl; | |
233 | /* | |
234 | * Converting a Lua table to an nvlist with key uniqueness checking is | |
235 | * O(n^2) in the number of keys in the nvlist, which can take a long | |
236 | * time when we return a large table from a channel program. | |
237 | * Furthermore, Lua's table interface *almost* guarantees unique keys | |
238 | * on its own (details below). Therefore, we don't use fnvlist_alloc() | |
239 | * here to avoid the built-in uniqueness checking. | |
240 | * | |
241 | * The *almost* is because it's possible to have key collisions between | |
242 | * e.g. the string "1" and the number 1, or the string "true" and the | |
243 | * boolean true, so we explicitly check that when we're looking at a | |
244 | * key which is an integer / boolean or a string that can be parsed as | |
245 | * one of those types. In the worst case this could still devolve into | |
246 | * O(n^2), so we only start doing these checks on boolean/integer keys | |
247 | * once we've seen a string key which fits this weird usage pattern. | |
248 | * | |
249 | * Ultimately, we still want callers to know that the keys in this | |
250 | * nvlist are unique, so before we return this we set the nvlist's | |
251 | * flags to reflect that. | |
252 | */ | |
253 | VERIFY0(nvlist_alloc(&nvl, 0, KM_SLEEP)); | |
254 | ||
255 | /* | |
256 | * Push an empty stack slot where lua_next() will store each | |
257 | * table key. | |
258 | */ | |
259 | lua_pushnil(state); | |
260 | boolean_t saw_str_could_collide = B_FALSE; | |
261 | while (lua_next(state, index) != 0) { | |
262 | /* | |
263 | * The next key-value pair from the table at index is | |
264 | * now on the stack, with the key at stack slot -2 and | |
265 | * the value at slot -1. | |
266 | */ | |
267 | int err = 0; | |
268 | char buf[32]; | |
269 | const char *key = NULL; | |
270 | boolean_t key_could_collide = B_FALSE; | |
271 | ||
272 | switch (lua_type(state, -2)) { | |
273 | case LUA_TSTRING: | |
274 | key = lua_tostring(state, -2); | |
275 | ||
276 | /* check if this could collide with a number or bool */ | |
277 | long long tmp; | |
278 | int parselen; | |
279 | if ((sscanf(key, "%lld%n", &tmp, &parselen) > 0 && | |
280 | parselen == strlen(key)) || | |
281 | strcmp(key, "true") == 0 || | |
282 | strcmp(key, "false") == 0) { | |
283 | key_could_collide = B_TRUE; | |
284 | saw_str_could_collide = B_TRUE; | |
285 | } | |
286 | break; | |
287 | case LUA_TBOOLEAN: | |
288 | key = (lua_toboolean(state, -2) == B_TRUE ? | |
289 | "true" : "false"); | |
290 | if (saw_str_could_collide) { | |
291 | key_could_collide = B_TRUE; | |
292 | } | |
293 | break; | |
294 | case LUA_TNUMBER: | |
295 | VERIFY3U(sizeof (buf), >, | |
296 | snprintf(buf, sizeof (buf), "%lld", | |
297 | (longlong_t)lua_tonumber(state, -2))); | |
298 | key = buf; | |
299 | if (saw_str_could_collide) { | |
300 | key_could_collide = B_TRUE; | |
301 | } | |
302 | break; | |
303 | default: | |
304 | fnvlist_free(nvl); | |
305 | (void) lua_pushfstring(state, "Invalid key " | |
306 | "type '%s' in table", | |
307 | lua_typename(state, lua_type(state, -2))); | |
308 | return (NULL); | |
309 | } | |
310 | /* | |
311 | * Check for type-mismatched key collisions, and throw an error. | |
312 | */ | |
313 | if (key_could_collide && nvlist_exists(nvl, key)) { | |
314 | fnvlist_free(nvl); | |
315 | (void) lua_pushfstring(state, "Collision of " | |
316 | "key '%s' in table", key); | |
317 | return (NULL); | |
318 | } | |
319 | /* | |
320 | * Recursively convert the table value and insert into | |
321 | * the new nvlist with the parsed key. To prevent | |
322 | * stack overflow on circular or heavily nested tables, | |
323 | * we track the current nvlist depth. | |
324 | */ | |
325 | if (depth >= ZCP_NVLIST_MAX_DEPTH) { | |
326 | fnvlist_free(nvl); | |
327 | (void) lua_pushfstring(state, "Maximum table " | |
328 | "depth (%d) exceeded for table", | |
329 | ZCP_NVLIST_MAX_DEPTH); | |
330 | return (NULL); | |
331 | } | |
332 | err = zcp_lua_to_nvlist_impl(state, -1, nvl, key, | |
333 | depth + 1); | |
334 | if (err != 0) { | |
335 | fnvlist_free(nvl); | |
336 | /* | |
337 | * Error message has been pushed to the lua | |
338 | * stack by the recursive call. | |
339 | */ | |
340 | return (NULL); | |
341 | } | |
342 | /* | |
343 | * Pop the value pushed by lua_next(). | |
344 | */ | |
345 | lua_pop(state, 1); | |
346 | } | |
347 | ||
348 | /* | |
349 | * Mark the nvlist as having unique keys. This is a little ugly, but we | |
350 | * ensured above that there are no duplicate keys in the nvlist. | |
351 | */ | |
352 | nvl->nvl_nvflag |= NV_UNIQUE_NAME; | |
353 | ||
354 | return (nvl); | |
355 | } | |
356 | ||
357 | /* | |
358 | * Convert a value from the given index into the lua stack to an nvpair, adding | |
359 | * it to an nvlist with the given key. | |
360 | * | |
361 | * Values are converted as follows: | |
362 | * | |
363 | * string -> string | |
364 | * number -> int64 | |
365 | * boolean -> boolean | |
366 | * nil -> boolean (no value) | |
367 | * | |
368 | * Lua tables are converted to nvlists and then inserted. The table's keys | |
369 | * are converted to strings then used as keys in the nvlist to store each table | |
370 | * element. Keys are converted as follows: | |
371 | * | |
372 | * string -> no change | |
373 | * number -> "%lld" | |
374 | * boolean -> "true" | "false" | |
375 | * nil -> error | |
376 | * | |
377 | * In the case of a key collision, an error is thrown. | |
378 | * | |
379 | * If an error is encountered, a nonzero error code is returned, and an error | |
380 | * string will be pushed onto the Lua stack. | |
381 | */ | |
382 | static int | |
383 | zcp_lua_to_nvlist_impl(lua_State *state, int index, nvlist_t *nvl, | |
384 | const char *key, int depth) | |
385 | { | |
386 | /* | |
387 | * Verify that we have enough remaining space in the lua stack to parse | |
388 | * a key-value pair and push an error. | |
389 | */ | |
390 | if (!lua_checkstack(state, 3)) { | |
391 | (void) lua_pushstring(state, "Lua stack overflow"); | |
392 | return (1); | |
393 | } | |
394 | ||
395 | index = lua_absindex(state, index); | |
396 | ||
397 | switch (lua_type(state, index)) { | |
398 | case LUA_TNIL: | |
399 | fnvlist_add_boolean(nvl, key); | |
400 | break; | |
401 | case LUA_TBOOLEAN: | |
402 | fnvlist_add_boolean_value(nvl, key, | |
403 | lua_toboolean(state, index)); | |
404 | break; | |
405 | case LUA_TNUMBER: | |
406 | fnvlist_add_int64(nvl, key, lua_tonumber(state, index)); | |
407 | break; | |
408 | case LUA_TSTRING: | |
409 | fnvlist_add_string(nvl, key, lua_tostring(state, index)); | |
410 | break; | |
411 | case LUA_TTABLE: { | |
412 | nvlist_t *value_nvl = zcp_table_to_nvlist(state, index, depth); | |
413 | if (value_nvl == NULL) | |
414 | return (EINVAL); | |
415 | ||
416 | fnvlist_add_nvlist(nvl, key, value_nvl); | |
417 | fnvlist_free(value_nvl); | |
418 | break; | |
419 | } | |
420 | default: | |
421 | (void) lua_pushfstring(state, | |
422 | "Invalid value type '%s' for key '%s'", | |
423 | lua_typename(state, lua_type(state, index)), key); | |
424 | return (EINVAL); | |
425 | } | |
426 | ||
427 | return (0); | |
428 | } | |
429 | ||
430 | /* | |
431 | * Convert a lua value to an nvpair, adding it to an nvlist with the given key. | |
432 | */ | |
433 | void | |
434 | zcp_lua_to_nvlist(lua_State *state, int index, nvlist_t *nvl, const char *key) | |
435 | { | |
436 | /* | |
437 | * On error, zcp_lua_to_nvlist_impl pushes an error string onto the Lua | |
438 | * stack before returning with a nonzero error code. If an error is | |
439 | * returned, throw a fatal lua error with the given string. | |
440 | */ | |
441 | if (zcp_lua_to_nvlist_impl(state, index, nvl, key, 0) != 0) | |
442 | (void) lua_error(state); | |
443 | } | |
444 | ||
445 | int | |
446 | zcp_lua_to_nvlist_helper(lua_State *state) | |
447 | { | |
448 | nvlist_t *nv = (nvlist_t *)lua_touserdata(state, 2); | |
449 | const char *key = (const char *)lua_touserdata(state, 1); | |
450 | zcp_lua_to_nvlist(state, 3, nv, key); | |
451 | return (0); | |
452 | } | |
453 | ||
454 | void | |
455 | zcp_convert_return_values(lua_State *state, nvlist_t *nvl, | |
456 | const char *key, zcp_eval_arg_t *evalargs) | |
457 | { | |
458 | int err; | |
459 | lua_pushcfunction(state, zcp_lua_to_nvlist_helper); | |
460 | lua_pushlightuserdata(state, (char *)key); | |
461 | lua_pushlightuserdata(state, nvl); | |
462 | lua_pushvalue(state, 1); | |
463 | lua_remove(state, 1); | |
464 | err = lua_pcall(state, 3, 0, 0); /* zcp_lua_to_nvlist_helper */ | |
465 | if (err != 0) { | |
466 | zcp_lua_to_nvlist(state, 1, nvl, ZCP_RET_ERROR); | |
467 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
468 | } | |
469 | } | |
470 | ||
471 | /* | |
472 | * Push a Lua table representing nvl onto the stack. If it can't be | |
473 | * converted, return EINVAL, fill in errbuf, and push nothing. errbuf may | |
474 | * be specified as NULL, in which case no error string will be output. | |
475 | * | |
476 | * Most nvlists are converted as simple key->value Lua tables, but we make | |
477 | * an exception for the case where all nvlist entries are BOOLEANs (a string | |
478 | * key without a value). In Lua, a table key pointing to a value of Nil | |
479 | * (no value) is equivalent to the key not existing, so a BOOLEAN nvlist | |
480 | * entry can't be directly converted to a Lua table entry. Nvlists of entirely | |
481 | * BOOLEAN entries are frequently used to pass around lists of datasets, so for | |
482 | * convenience we check for this case, and convert it to a simple Lua array of | |
483 | * strings. | |
484 | */ | |
485 | int | |
486 | zcp_nvlist_to_lua(lua_State *state, nvlist_t *nvl, | |
487 | char *errbuf, int errbuf_len) | |
488 | { | |
489 | nvpair_t *pair; | |
490 | lua_newtable(state); | |
491 | boolean_t has_values = B_FALSE; | |
492 | /* | |
493 | * If the list doesn't have any values, just convert it to a string | |
494 | * array. | |
495 | */ | |
496 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
497 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
498 | if (nvpair_type(pair) != DATA_TYPE_BOOLEAN) { | |
499 | has_values = B_TRUE; | |
500 | break; | |
501 | } | |
502 | } | |
503 | if (!has_values) { | |
504 | int i = 1; | |
505 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
506 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
507 | (void) lua_pushinteger(state, i); | |
508 | (void) lua_pushstring(state, nvpair_name(pair)); | |
509 | (void) lua_settable(state, -3); | |
510 | i++; | |
511 | } | |
512 | } else { | |
513 | for (pair = nvlist_next_nvpair(nvl, NULL); | |
514 | pair != NULL; pair = nvlist_next_nvpair(nvl, pair)) { | |
515 | int err = zcp_nvpair_value_to_lua(state, pair, | |
516 | errbuf, errbuf_len); | |
517 | if (err != 0) { | |
518 | lua_pop(state, 1); | |
519 | return (err); | |
520 | } | |
521 | (void) lua_setfield(state, -2, nvpair_name(pair)); | |
522 | } | |
523 | } | |
524 | return (0); | |
525 | } | |
526 | ||
527 | /* | |
528 | * Push a Lua object representing the value of "pair" onto the stack. | |
529 | * | |
530 | * Only understands boolean_value, string, int64, nvlist, | |
531 | * string_array, and int64_array type values. For other | |
532 | * types, returns EINVAL, fills in errbuf, and pushes nothing. | |
533 | */ | |
534 | static int | |
535 | zcp_nvpair_value_to_lua(lua_State *state, nvpair_t *pair, | |
536 | char *errbuf, int errbuf_len) | |
537 | { | |
538 | int err = 0; | |
539 | ||
540 | if (pair == NULL) { | |
541 | lua_pushnil(state); | |
542 | return (0); | |
543 | } | |
544 | ||
545 | switch (nvpair_type(pair)) { | |
546 | case DATA_TYPE_BOOLEAN_VALUE: | |
547 | (void) lua_pushboolean(state, | |
548 | fnvpair_value_boolean_value(pair)); | |
549 | break; | |
550 | case DATA_TYPE_STRING: | |
551 | (void) lua_pushstring(state, fnvpair_value_string(pair)); | |
552 | break; | |
553 | case DATA_TYPE_INT64: | |
554 | (void) lua_pushinteger(state, fnvpair_value_int64(pair)); | |
555 | break; | |
556 | case DATA_TYPE_NVLIST: | |
557 | err = zcp_nvlist_to_lua(state, | |
558 | fnvpair_value_nvlist(pair), errbuf, errbuf_len); | |
559 | break; | |
560 | case DATA_TYPE_STRING_ARRAY: { | |
561 | char **strarr; | |
562 | uint_t nelem; | |
563 | (void) nvpair_value_string_array(pair, &strarr, &nelem); | |
564 | lua_newtable(state); | |
565 | for (int i = 0; i < nelem; i++) { | |
566 | (void) lua_pushinteger(state, i + 1); | |
567 | (void) lua_pushstring(state, strarr[i]); | |
568 | (void) lua_settable(state, -3); | |
569 | } | |
570 | break; | |
571 | } | |
572 | case DATA_TYPE_UINT64_ARRAY: { | |
573 | uint64_t *intarr; | |
574 | uint_t nelem; | |
575 | (void) nvpair_value_uint64_array(pair, &intarr, &nelem); | |
576 | lua_newtable(state); | |
577 | for (int i = 0; i < nelem; i++) { | |
578 | (void) lua_pushinteger(state, i + 1); | |
579 | (void) lua_pushinteger(state, intarr[i]); | |
580 | (void) lua_settable(state, -3); | |
581 | } | |
582 | break; | |
583 | } | |
584 | case DATA_TYPE_INT64_ARRAY: { | |
585 | int64_t *intarr; | |
586 | uint_t nelem; | |
587 | (void) nvpair_value_int64_array(pair, &intarr, &nelem); | |
588 | lua_newtable(state); | |
589 | for (int i = 0; i < nelem; i++) { | |
590 | (void) lua_pushinteger(state, i + 1); | |
591 | (void) lua_pushinteger(state, intarr[i]); | |
592 | (void) lua_settable(state, -3); | |
593 | } | |
594 | break; | |
595 | } | |
596 | default: { | |
597 | if (errbuf != NULL) { | |
598 | (void) snprintf(errbuf, errbuf_len, | |
599 | "Unhandled nvpair type %d for key '%s'", | |
600 | nvpair_type(pair), nvpair_name(pair)); | |
601 | } | |
602 | return (EINVAL); | |
603 | } | |
604 | } | |
605 | return (err); | |
606 | } | |
607 | ||
608 | int | |
609 | zcp_dataset_hold_error(lua_State *state, dsl_pool_t *dp, const char *dsname, | |
610 | int error) | |
611 | { | |
612 | if (error == ENOENT) { | |
613 | (void) zcp_argerror(state, 1, "no such dataset '%s'", dsname); | |
614 | return (0); /* not reached; zcp_argerror will longjmp */ | |
615 | } else if (error == EXDEV) { | |
616 | (void) zcp_argerror(state, 1, | |
617 | "dataset '%s' is not in the target pool '%s'", | |
618 | dsname, spa_name(dp->dp_spa)); | |
619 | return (0); /* not reached; zcp_argerror will longjmp */ | |
620 | } else if (error == EIO) { | |
621 | (void) luaL_error(state, | |
622 | "I/O error while accessing dataset '%s'", dsname); | |
623 | return (0); /* not reached; luaL_error will longjmp */ | |
624 | } else if (error != 0) { | |
625 | (void) luaL_error(state, | |
626 | "unexpected error %d while accessing dataset '%s'", | |
627 | error, dsname); | |
628 | return (0); /* not reached; luaL_error will longjmp */ | |
629 | } | |
630 | return (0); | |
631 | } | |
632 | ||
633 | /* | |
634 | * Note: will longjmp (via lua_error()) on error. | |
635 | * Assumes that the dsname is argument #1 (for error reporting purposes). | |
636 | */ | |
637 | dsl_dataset_t * | |
638 | zcp_dataset_hold(lua_State *state, dsl_pool_t *dp, const char *dsname, | |
639 | void *tag) | |
640 | { | |
641 | dsl_dataset_t *ds; | |
642 | int error = dsl_dataset_hold(dp, dsname, tag, &ds); | |
643 | (void) zcp_dataset_hold_error(state, dp, dsname, error); | |
644 | return (ds); | |
645 | } | |
646 | ||
647 | static int zcp_debug(lua_State *); | |
648 | static zcp_lib_info_t zcp_debug_info = { | |
649 | .name = "debug", | |
650 | .func = zcp_debug, | |
651 | .pargs = { | |
652 | { .za_name = "debug string", .za_lua_type = LUA_TSTRING}, | |
653 | {NULL, 0} | |
654 | }, | |
655 | .kwargs = { | |
656 | {NULL, 0} | |
657 | } | |
658 | }; | |
659 | ||
660 | static int | |
661 | zcp_debug(lua_State *state) | |
662 | { | |
663 | const char *dbgstring; | |
664 | zcp_run_info_t *ri = zcp_run_info(state); | |
665 | zcp_lib_info_t *libinfo = &zcp_debug_info; | |
666 | ||
667 | zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs); | |
668 | ||
669 | dbgstring = lua_tostring(state, 1); | |
670 | ||
671 | zfs_dbgmsg("txg %lld ZCP: %s", ri->zri_tx->tx_txg, dbgstring); | |
672 | ||
673 | return (0); | |
674 | } | |
675 | ||
676 | static int zcp_exists(lua_State *); | |
677 | static zcp_lib_info_t zcp_exists_info = { | |
678 | .name = "exists", | |
679 | .func = zcp_exists, | |
680 | .pargs = { | |
681 | { .za_name = "dataset", .za_lua_type = LUA_TSTRING}, | |
682 | {NULL, 0} | |
683 | }, | |
684 | .kwargs = { | |
685 | {NULL, 0} | |
686 | } | |
687 | }; | |
688 | ||
689 | static int | |
690 | zcp_exists(lua_State *state) | |
691 | { | |
692 | zcp_run_info_t *ri = zcp_run_info(state); | |
693 | dsl_pool_t *dp = ri->zri_pool; | |
694 | zcp_lib_info_t *libinfo = &zcp_exists_info; | |
695 | ||
696 | zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs); | |
697 | ||
698 | const char *dsname = lua_tostring(state, 1); | |
699 | ||
700 | dsl_dataset_t *ds; | |
701 | int error = dsl_dataset_hold(dp, dsname, FTAG, &ds); | |
702 | if (error == 0) { | |
703 | dsl_dataset_rele(ds, FTAG); | |
704 | lua_pushboolean(state, B_TRUE); | |
705 | } else if (error == ENOENT) { | |
706 | lua_pushboolean(state, B_FALSE); | |
707 | } else if (error == EXDEV) { | |
708 | return (luaL_error(state, "dataset '%s' is not in the " | |
709 | "target pool", dsname)); | |
710 | } else if (error == EIO) { | |
711 | return (luaL_error(state, "I/O error opening dataset '%s'", | |
712 | dsname)); | |
713 | } else if (error != 0) { | |
714 | return (luaL_error(state, "unexpected error %d", error)); | |
715 | } | |
716 | ||
475eca49 | 717 | return (1); |
d99a0153 CW |
718 | } |
719 | ||
720 | /* | |
721 | * Allocate/realloc/free a buffer for the lua interpreter. | |
722 | * | |
723 | * When nsize is 0, behaves as free() and returns NULL. | |
724 | * | |
725 | * If ptr is NULL, behaves as malloc() and returns an allocated buffer of size | |
726 | * at least nsize. | |
727 | * | |
728 | * Otherwise, behaves as realloc(), changing the allocation from osize to nsize. | |
729 | * Shrinking the buffer size never fails. | |
730 | * | |
731 | * The original allocated buffer size is stored as a uint64 at the beginning of | |
732 | * the buffer to avoid actually reallocating when shrinking a buffer, since lua | |
733 | * requires that this operation never fail. | |
734 | */ | |
735 | static void * | |
736 | zcp_lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize) | |
737 | { | |
738 | zcp_alloc_arg_t *allocargs = ud; | |
739 | int flags = (allocargs->aa_must_succeed) ? | |
740 | KM_SLEEP : (KM_NOSLEEP | KM_NORMALPRI); | |
741 | ||
742 | if (nsize == 0) { | |
743 | if (ptr != NULL) { | |
744 | int64_t *allocbuf = (int64_t *)ptr - 1; | |
745 | int64_t allocsize = *allocbuf; | |
746 | ASSERT3S(allocsize, >, 0); | |
747 | ASSERT3S(allocargs->aa_alloc_remaining + allocsize, <=, | |
748 | allocargs->aa_alloc_limit); | |
749 | allocargs->aa_alloc_remaining += allocsize; | |
750 | vmem_free(allocbuf, allocsize); | |
751 | } | |
752 | return (NULL); | |
753 | } else if (ptr == NULL) { | |
754 | int64_t *allocbuf; | |
755 | int64_t allocsize = nsize + sizeof (int64_t); | |
756 | ||
757 | if (!allocargs->aa_must_succeed && | |
758 | (allocsize <= 0 || | |
759 | allocsize > allocargs->aa_alloc_remaining)) { | |
760 | return (NULL); | |
761 | } | |
762 | ||
763 | allocbuf = vmem_alloc(allocsize, flags); | |
764 | if (allocbuf == NULL) { | |
765 | return (NULL); | |
766 | } | |
767 | allocargs->aa_alloc_remaining -= allocsize; | |
768 | ||
769 | *allocbuf = allocsize; | |
770 | return (allocbuf + 1); | |
771 | } else if (nsize <= osize) { | |
772 | /* | |
773 | * If shrinking the buffer, lua requires that the reallocation | |
774 | * never fail. | |
775 | */ | |
776 | return (ptr); | |
777 | } else { | |
778 | ASSERT3U(nsize, >, osize); | |
779 | ||
780 | uint64_t *luabuf = zcp_lua_alloc(ud, NULL, 0, nsize); | |
781 | if (luabuf == NULL) { | |
782 | return (NULL); | |
783 | } | |
784 | (void) memcpy(luabuf, ptr, osize); | |
785 | VERIFY3P(zcp_lua_alloc(ud, ptr, osize, 0), ==, NULL); | |
786 | return (luabuf); | |
787 | } | |
788 | } | |
789 | ||
790 | /* ARGSUSED */ | |
791 | static void | |
792 | zcp_lua_counthook(lua_State *state, lua_Debug *ar) | |
793 | { | |
794 | /* | |
795 | * If we're called, check how many instructions the channel program has | |
796 | * executed so far, and compare against the limit. | |
797 | */ | |
798 | lua_getfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
799 | zcp_run_info_t *ri = lua_touserdata(state, -1); | |
800 | ||
801 | ri->zri_curinstrs += zfs_lua_check_instrlimit_interval; | |
802 | if (ri->zri_maxinstrs != 0 && ri->zri_curinstrs > ri->zri_maxinstrs) { | |
803 | ri->zri_timed_out = B_TRUE; | |
804 | (void) lua_pushstring(state, | |
805 | "Channel program timed out."); | |
806 | (void) lua_error(state); | |
807 | } | |
808 | } | |
809 | ||
810 | static int | |
811 | zcp_panic_cb(lua_State *state) | |
812 | { | |
813 | panic("unprotected error in call to Lua API (%s)\n", | |
814 | lua_tostring(state, -1)); | |
815 | return (0); | |
816 | } | |
817 | ||
818 | static void | |
5b72a38d | 819 | zcp_eval_impl(dmu_tx_t *tx, boolean_t sync, zcp_eval_arg_t *evalargs) |
d99a0153 CW |
820 | { |
821 | int err; | |
822 | zcp_run_info_t ri; | |
d99a0153 CW |
823 | lua_State *state = evalargs->ea_state; |
824 | ||
d99a0153 CW |
825 | VERIFY3U(3, ==, lua_gettop(state)); |
826 | ||
827 | /* | |
828 | * Store the zcp_run_info_t struct for this run in the Lua registry. | |
829 | * Registry entries are not directly accessible by the Lua scripts but | |
830 | * can be accessed by our callbacks. | |
831 | */ | |
832 | ri.zri_space_used = 0; | |
833 | ri.zri_pool = dmu_tx_pool(tx); | |
834 | ri.zri_cred = evalargs->ea_cred; | |
835 | ri.zri_tx = tx; | |
836 | ri.zri_timed_out = B_FALSE; | |
5b72a38d SD |
837 | ri.zri_sync = sync; |
838 | list_create(&ri.zri_cleanup_handlers, sizeof (zcp_cleanup_handler_t), | |
839 | offsetof(zcp_cleanup_handler_t, zch_node)); | |
d99a0153 CW |
840 | ri.zri_curinstrs = 0; |
841 | ri.zri_maxinstrs = evalargs->ea_instrlimit; | |
842 | ||
843 | lua_pushlightuserdata(state, &ri); | |
844 | lua_setfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
845 | VERIFY3U(3, ==, lua_gettop(state)); | |
846 | ||
847 | /* | |
848 | * Tell the Lua interpreter to call our handler every count | |
849 | * instructions. Channel programs that execute too many instructions | |
850 | * should die with ETIME. | |
851 | */ | |
852 | (void) lua_sethook(state, zcp_lua_counthook, LUA_MASKCOUNT, | |
853 | zfs_lua_check_instrlimit_interval); | |
854 | ||
855 | /* | |
856 | * Tell the Lua memory allocator to stop using KM_SLEEP before handing | |
857 | * off control to the channel program. Channel programs that use too | |
858 | * much memory should die with ENOSPC. | |
859 | */ | |
860 | evalargs->ea_allocargs->aa_must_succeed = B_FALSE; | |
861 | ||
862 | /* | |
863 | * Call the Lua function that open-context passed us. This pops the | |
864 | * function and its input from the stack and pushes any return | |
865 | * or error values. | |
866 | */ | |
867 | err = lua_pcall(state, 1, LUA_MULTRET, 1); | |
868 | ||
869 | /* | |
870 | * Let Lua use KM_SLEEP while we interpret the return values. | |
871 | */ | |
872 | evalargs->ea_allocargs->aa_must_succeed = B_TRUE; | |
873 | ||
874 | /* | |
875 | * Remove the error handler callback from the stack. At this point, | |
5b72a38d SD |
876 | * there shouldn't be any cleanup handler registered in the handler |
877 | * list (zri_cleanup_handlers), regardless of whether it ran or not. | |
d99a0153 | 878 | */ |
5b72a38d | 879 | list_destroy(&ri.zri_cleanup_handlers); |
d99a0153 CW |
880 | lua_remove(state, 1); |
881 | ||
882 | switch (err) { | |
883 | case LUA_OK: { | |
884 | /* | |
885 | * Lua supports returning multiple values in a single return | |
886 | * statement. Return values will have been pushed onto the | |
887 | * stack: | |
888 | * 1: Return value 1 | |
889 | * 2: Return value 2 | |
890 | * 3: etc... | |
891 | * To simplify the process of retrieving a return value from a | |
892 | * channel program, we disallow returning more than one value | |
893 | * to ZFS from the Lua script, yielding a singleton return | |
894 | * nvlist of the form { "return": Return value 1 }. | |
895 | */ | |
896 | int return_count = lua_gettop(state); | |
897 | ||
898 | if (return_count == 1) { | |
899 | evalargs->ea_result = 0; | |
900 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
901 | ZCP_RET_RETURN, evalargs); | |
902 | } else if (return_count > 1) { | |
903 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
904 | (void) lua_pushfstring(state, "Multiple return " | |
905 | "values not supported"); | |
906 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
907 | ZCP_RET_ERROR, evalargs); | |
908 | } | |
909 | break; | |
910 | } | |
911 | case LUA_ERRRUN: | |
912 | case LUA_ERRGCMM: { | |
913 | /* | |
914 | * The channel program encountered a fatal error within the | |
915 | * script, such as failing an assertion, or calling a function | |
916 | * with incompatible arguments. The error value and the | |
917 | * traceback generated by zcp_error_handler() should be on the | |
918 | * stack. | |
919 | */ | |
920 | VERIFY3U(1, ==, lua_gettop(state)); | |
921 | if (ri.zri_timed_out) { | |
922 | evalargs->ea_result = SET_ERROR(ETIME); | |
923 | } else { | |
924 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
925 | } | |
926 | ||
927 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
928 | ZCP_RET_ERROR, evalargs); | |
929 | ||
930 | if (evalargs->ea_result == ETIME && | |
931 | evalargs->ea_outnvl != NULL) { | |
932 | (void) nvlist_add_uint64(evalargs->ea_outnvl, | |
933 | ZCP_ARG_INSTRLIMIT, ri.zri_curinstrs); | |
934 | } | |
935 | break; | |
936 | } | |
937 | case LUA_ERRERR: { | |
938 | /* | |
939 | * The channel program encountered a fatal error within the | |
940 | * script, and we encountered another error while trying to | |
941 | * compute the traceback in zcp_error_handler(). We can only | |
942 | * return the error message. | |
943 | */ | |
944 | VERIFY3U(1, ==, lua_gettop(state)); | |
945 | if (ri.zri_timed_out) { | |
946 | evalargs->ea_result = SET_ERROR(ETIME); | |
947 | } else { | |
948 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
949 | } | |
950 | ||
951 | zcp_convert_return_values(state, evalargs->ea_outnvl, | |
952 | ZCP_RET_ERROR, evalargs); | |
953 | break; | |
954 | } | |
955 | case LUA_ERRMEM: | |
956 | /* | |
957 | * Lua ran out of memory while running the channel program. | |
958 | * There's not much we can do. | |
959 | */ | |
960 | evalargs->ea_result = SET_ERROR(ENOSPC); | |
961 | break; | |
962 | default: | |
963 | VERIFY0(err); | |
964 | } | |
965 | } | |
966 | ||
5b72a38d SD |
967 | static void |
968 | zcp_pool_error(zcp_eval_arg_t *evalargs, const char *poolname) | |
969 | { | |
970 | evalargs->ea_result = SET_ERROR(ECHRNG); | |
971 | (void) lua_pushfstring(evalargs->ea_state, "Could not open pool: %s", | |
972 | poolname); | |
973 | zcp_convert_return_values(evalargs->ea_state, evalargs->ea_outnvl, | |
974 | ZCP_RET_ERROR, evalargs); | |
975 | ||
976 | } | |
977 | ||
978 | static void | |
979 | zcp_eval_sync(void *arg, dmu_tx_t *tx) | |
980 | { | |
981 | zcp_eval_arg_t *evalargs = arg; | |
982 | ||
983 | /* | |
984 | * Open context should have setup the stack to contain: | |
985 | * 1: Error handler callback | |
986 | * 2: Script to run (converted to a Lua function) | |
987 | * 3: nvlist input to function (converted to Lua table or nil) | |
988 | */ | |
989 | VERIFY3U(3, ==, lua_gettop(evalargs->ea_state)); | |
990 | ||
991 | zcp_eval_impl(tx, B_TRUE, evalargs); | |
992 | } | |
993 | ||
994 | static void | |
995 | zcp_eval_open(zcp_eval_arg_t *evalargs, const char *poolname) | |
996 | { | |
997 | ||
998 | int error; | |
999 | dsl_pool_t *dp; | |
1000 | dmu_tx_t *tx; | |
1001 | ||
1002 | /* | |
1003 | * See comment from the same assertion in zcp_eval_sync(). | |
1004 | */ | |
1005 | VERIFY3U(3, ==, lua_gettop(evalargs->ea_state)); | |
1006 | ||
1007 | error = dsl_pool_hold(poolname, FTAG, &dp); | |
1008 | if (error != 0) { | |
1009 | zcp_pool_error(evalargs, poolname); | |
1010 | return; | |
1011 | } | |
1012 | ||
1013 | /* | |
1014 | * As we are running in open-context, we have no transaction associated | |
1015 | * with the channel program. At the same time, functions from the | |
1016 | * zfs.check submodule need to be associated with a transaction as | |
1017 | * they are basically dry-runs of their counterparts in the zfs.sync | |
1018 | * submodule. These functions should be able to run in open-context. | |
1019 | * Therefore we create a new transaction that we later abort once | |
1020 | * the channel program has been evaluated. | |
1021 | */ | |
1022 | tx = dmu_tx_create_dd(dp->dp_mos_dir); | |
1023 | ||
1024 | zcp_eval_impl(tx, B_FALSE, evalargs); | |
1025 | ||
1026 | dmu_tx_abort(tx); | |
1027 | ||
1028 | dsl_pool_rele(dp, FTAG); | |
1029 | } | |
1030 | ||
d99a0153 | 1031 | int |
5b72a38d SD |
1032 | zcp_eval(const char *poolname, const char *program, boolean_t sync, |
1033 | uint64_t instrlimit, uint64_t memlimit, nvpair_t *nvarg, nvlist_t *outnvl) | |
d99a0153 CW |
1034 | { |
1035 | int err; | |
1036 | lua_State *state; | |
1037 | zcp_eval_arg_t evalargs; | |
1038 | ||
1039 | if (instrlimit > zfs_lua_max_instrlimit) | |
1040 | return (SET_ERROR(EINVAL)); | |
1041 | if (memlimit == 0 || memlimit > zfs_lua_max_memlimit) | |
1042 | return (SET_ERROR(EINVAL)); | |
1043 | ||
1044 | zcp_alloc_arg_t allocargs = { | |
1045 | .aa_must_succeed = B_TRUE, | |
1046 | .aa_alloc_remaining = (int64_t)memlimit, | |
1047 | .aa_alloc_limit = (int64_t)memlimit, | |
1048 | }; | |
1049 | ||
1050 | /* | |
1051 | * Creates a Lua state with a memory allocator that uses KM_SLEEP. | |
1052 | * This should never fail. | |
1053 | */ | |
1054 | state = lua_newstate(zcp_lua_alloc, &allocargs); | |
1055 | VERIFY(state != NULL); | |
1056 | (void) lua_atpanic(state, zcp_panic_cb); | |
1057 | ||
1058 | /* | |
1059 | * Load core Lua libraries we want access to. | |
1060 | */ | |
1061 | VERIFY3U(1, ==, luaopen_base(state)); | |
1062 | lua_pop(state, 1); | |
1063 | VERIFY3U(1, ==, luaopen_coroutine(state)); | |
1064 | lua_setglobal(state, LUA_COLIBNAME); | |
1065 | VERIFY0(lua_gettop(state)); | |
1066 | VERIFY3U(1, ==, luaopen_string(state)); | |
1067 | lua_setglobal(state, LUA_STRLIBNAME); | |
1068 | VERIFY0(lua_gettop(state)); | |
1069 | VERIFY3U(1, ==, luaopen_table(state)); | |
1070 | lua_setglobal(state, LUA_TABLIBNAME); | |
1071 | VERIFY0(lua_gettop(state)); | |
1072 | ||
1073 | /* | |
1074 | * Load globally visible variables such as errno aliases. | |
1075 | */ | |
1076 | zcp_load_globals(state); | |
1077 | VERIFY0(lua_gettop(state)); | |
1078 | ||
1079 | /* | |
1080 | * Load ZFS-specific modules. | |
1081 | */ | |
1082 | lua_newtable(state); | |
1083 | VERIFY3U(1, ==, zcp_load_list_lib(state)); | |
1084 | lua_setfield(state, -2, "list"); | |
1085 | VERIFY3U(1, ==, zcp_load_synctask_lib(state, B_FALSE)); | |
1086 | lua_setfield(state, -2, "check"); | |
1087 | VERIFY3U(1, ==, zcp_load_synctask_lib(state, B_TRUE)); | |
1088 | lua_setfield(state, -2, "sync"); | |
1089 | VERIFY3U(1, ==, zcp_load_get_lib(state)); | |
1090 | lua_pushcclosure(state, zcp_debug_info.func, 0); | |
1091 | lua_setfield(state, -2, zcp_debug_info.name); | |
1092 | lua_pushcclosure(state, zcp_exists_info.func, 0); | |
1093 | lua_setfield(state, -2, zcp_exists_info.name); | |
1094 | lua_setglobal(state, "zfs"); | |
1095 | VERIFY0(lua_gettop(state)); | |
1096 | ||
1097 | /* | |
1098 | * Push the error-callback that calculates Lua stack traces on | |
1099 | * unexpected failures. | |
1100 | */ | |
1101 | lua_pushcfunction(state, zcp_error_handler); | |
1102 | VERIFY3U(1, ==, lua_gettop(state)); | |
1103 | ||
1104 | /* | |
1105 | * Load the actual script as a function onto the stack as text ("t"). | |
1106 | * The only valid error condition is a syntax error in the script. | |
1107 | * ERRMEM should not be possible because our allocator is using | |
1108 | * KM_SLEEP. ERRGCMM should not be possible because we have not added | |
1109 | * any objects with __gc metamethods to the interpreter that could | |
1110 | * fail. | |
1111 | */ | |
1112 | err = luaL_loadbufferx(state, program, strlen(program), | |
1113 | "channel program", "t"); | |
1114 | if (err == LUA_ERRSYNTAX) { | |
1115 | fnvlist_add_string(outnvl, ZCP_RET_ERROR, | |
1116 | lua_tostring(state, -1)); | |
1117 | lua_close(state); | |
1118 | return (SET_ERROR(EINVAL)); | |
1119 | } | |
1120 | VERIFY0(err); | |
1121 | VERIFY3U(2, ==, lua_gettop(state)); | |
1122 | ||
1123 | /* | |
1124 | * Convert the input nvlist to a Lua object and put it on top of the | |
1125 | * stack. | |
1126 | */ | |
1127 | char errmsg[128]; | |
1128 | err = zcp_nvpair_value_to_lua(state, nvarg, | |
1129 | errmsg, sizeof (errmsg)); | |
1130 | if (err != 0) { | |
1131 | fnvlist_add_string(outnvl, ZCP_RET_ERROR, errmsg); | |
1132 | lua_close(state); | |
1133 | return (SET_ERROR(EINVAL)); | |
1134 | } | |
1135 | VERIFY3U(3, ==, lua_gettop(state)); | |
1136 | ||
1137 | evalargs.ea_state = state; | |
1138 | evalargs.ea_allocargs = &allocargs; | |
1139 | evalargs.ea_instrlimit = instrlimit; | |
1140 | evalargs.ea_cred = CRED(); | |
1141 | evalargs.ea_outnvl = outnvl; | |
1142 | evalargs.ea_result = 0; | |
1143 | ||
5b72a38d SD |
1144 | if (sync) { |
1145 | err = dsl_sync_task(poolname, NULL, | |
1146 | zcp_eval_sync, &evalargs, 0, ZFS_SPACE_CHECK_NONE); | |
1147 | if (err != 0) | |
1148 | zcp_pool_error(&evalargs, poolname); | |
1149 | } else { | |
1150 | zcp_eval_open(&evalargs, poolname); | |
1151 | } | |
d99a0153 CW |
1152 | lua_close(state); |
1153 | ||
1154 | return (evalargs.ea_result); | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Retrieve metadata about the currently running channel program. | |
1159 | */ | |
1160 | zcp_run_info_t * | |
1161 | zcp_run_info(lua_State *state) | |
1162 | { | |
1163 | zcp_run_info_t *ri; | |
1164 | ||
1165 | lua_getfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY); | |
1166 | ri = lua_touserdata(state, -1); | |
1167 | lua_pop(state, 1); | |
1168 | return (ri); | |
1169 | } | |
1170 | ||
1171 | /* | |
1172 | * Argument Parsing | |
1173 | * ================ | |
1174 | * | |
1175 | * The Lua language allows methods to be called with any number | |
1176 | * of arguments of any type. When calling back into ZFS we need to sanitize | |
1177 | * arguments from channel programs to make sure unexpected arguments or | |
1178 | * arguments of the wrong type result in clear error messages. To do this | |
1179 | * in a uniform way all callbacks from channel programs should use the | |
1180 | * zcp_parse_args() function to interpret inputs. | |
1181 | * | |
1182 | * Positional vs Keyword Arguments | |
1183 | * =============================== | |
1184 | * | |
1185 | * Every callback function takes a fixed set of required positional arguments | |
1186 | * and optional keyword arguments. For example, the destroy function takes | |
1187 | * a single positional string argument (the name of the dataset to destroy) | |
1188 | * and an optional "defer" keyword boolean argument. When calling lua functions | |
1189 | * with parentheses, only positional arguments can be used: | |
1190 | * | |
1191 | * zfs.sync.snapshot("rpool@snap") | |
1192 | * | |
1193 | * To use keyword arguments functions should be called with a single argument | |
1194 | * that is a lua table containing mappings of integer -> positional arguments | |
1195 | * and string -> keyword arguments: | |
1196 | * | |
1197 | * zfs.sync.snapshot({1="rpool@snap", defer=true}) | |
1198 | * | |
1199 | * The lua language allows curly braces to be used in place of parenthesis as | |
1200 | * syntactic sugar for this calling convention: | |
1201 | * | |
1202 | * zfs.sync.snapshot{"rpool@snap", defer=true} | |
1203 | */ | |
1204 | ||
1205 | /* | |
1206 | * Throw an error and print the given arguments. If there are too many | |
1207 | * arguments to fit in the output buffer, only the error format string is | |
1208 | * output. | |
1209 | */ | |
1210 | static void | |
1211 | zcp_args_error(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1212 | const zcp_arg_t *kwargs, const char *fmt, ...) | |
1213 | { | |
1214 | int i; | |
1215 | char errmsg[512]; | |
1216 | size_t len = sizeof (errmsg); | |
1217 | size_t msglen = 0; | |
1218 | va_list argp; | |
1219 | ||
1220 | va_start(argp, fmt); | |
1221 | VERIFY3U(len, >, vsnprintf(errmsg, len, fmt, argp)); | |
1222 | va_end(argp); | |
1223 | ||
1224 | /* | |
1225 | * Calculate the total length of the final string, including extra | |
1226 | * formatting characters. If the argument dump would be too large, | |
1227 | * only print the error string. | |
1228 | */ | |
1229 | msglen = strlen(errmsg); | |
1230 | msglen += strlen(fname) + 4; /* : + {} + null terminator */ | |
1231 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1232 | msglen += strlen(pargs[i].za_name); | |
1233 | msglen += strlen(lua_typename(state, pargs[i].za_lua_type)); | |
1234 | if (pargs[i + 1].za_name != NULL || kwargs[0].za_name != NULL) | |
1235 | msglen += 5; /* < + ( + )> + , */ | |
1236 | else | |
1237 | msglen += 4; /* < + ( + )> */ | |
1238 | } | |
1239 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1240 | msglen += strlen(kwargs[i].za_name); | |
1241 | msglen += strlen(lua_typename(state, kwargs[i].za_lua_type)); | |
1242 | if (kwargs[i + 1].za_name != NULL) | |
1243 | msglen += 4; /* =( + ) + , */ | |
1244 | else | |
1245 | msglen += 3; /* =( + ) */ | |
1246 | } | |
1247 | ||
1248 | if (msglen >= len) | |
1249 | (void) luaL_error(state, errmsg); | |
1250 | ||
1251 | VERIFY3U(len, >, strlcat(errmsg, ": ", len)); | |
1252 | VERIFY3U(len, >, strlcat(errmsg, fname, len)); | |
1253 | VERIFY3U(len, >, strlcat(errmsg, "{", len)); | |
1254 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1255 | VERIFY3U(len, >, strlcat(errmsg, "<", len)); | |
1256 | VERIFY3U(len, >, strlcat(errmsg, pargs[i].za_name, len)); | |
1257 | VERIFY3U(len, >, strlcat(errmsg, "(", len)); | |
1258 | VERIFY3U(len, >, strlcat(errmsg, | |
1259 | lua_typename(state, pargs[i].za_lua_type), len)); | |
1260 | VERIFY3U(len, >, strlcat(errmsg, ")>", len)); | |
1261 | if (pargs[i + 1].za_name != NULL || kwargs[0].za_name != NULL) { | |
1262 | VERIFY3U(len, >, strlcat(errmsg, ", ", len)); | |
1263 | } | |
1264 | } | |
1265 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1266 | VERIFY3U(len, >, strlcat(errmsg, kwargs[i].za_name, len)); | |
1267 | VERIFY3U(len, >, strlcat(errmsg, "=(", len)); | |
1268 | VERIFY3U(len, >, strlcat(errmsg, | |
1269 | lua_typename(state, kwargs[i].za_lua_type), len)); | |
1270 | VERIFY3U(len, >, strlcat(errmsg, ")", len)); | |
1271 | if (kwargs[i + 1].za_name != NULL) { | |
1272 | VERIFY3U(len, >, strlcat(errmsg, ", ", len)); | |
1273 | } | |
1274 | } | |
1275 | VERIFY3U(len, >, strlcat(errmsg, "}", len)); | |
1276 | ||
1277 | (void) luaL_error(state, errmsg); | |
1278 | panic("unreachable code"); | |
1279 | } | |
1280 | ||
1281 | static void | |
1282 | zcp_parse_table_args(lua_State *state, const char *fname, | |
1283 | const zcp_arg_t *pargs, const zcp_arg_t *kwargs) | |
1284 | { | |
1285 | int i; | |
1286 | int type; | |
1287 | ||
1288 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1289 | /* | |
1290 | * Check the table for this positional argument, leaving it | |
1291 | * on the top of the stack once we finish validating it. | |
1292 | */ | |
1293 | lua_pushinteger(state, i + 1); | |
1294 | lua_gettable(state, 1); | |
1295 | ||
1296 | type = lua_type(state, -1); | |
1297 | if (type == LUA_TNIL) { | |
1298 | zcp_args_error(state, fname, pargs, kwargs, | |
1299 | "too few arguments"); | |
1300 | panic("unreachable code"); | |
1301 | } else if (type != pargs[i].za_lua_type) { | |
1302 | zcp_args_error(state, fname, pargs, kwargs, | |
1303 | "arg %d wrong type (is '%s', expected '%s')", | |
1304 | i + 1, lua_typename(state, type), | |
1305 | lua_typename(state, pargs[i].za_lua_type)); | |
1306 | panic("unreachable code"); | |
1307 | } | |
1308 | ||
1309 | /* | |
1310 | * Remove the positional argument from the table. | |
1311 | */ | |
1312 | lua_pushinteger(state, i + 1); | |
1313 | lua_pushnil(state); | |
1314 | lua_settable(state, 1); | |
1315 | } | |
1316 | ||
1317 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1318 | /* | |
1319 | * Check the table for this keyword argument, which may be | |
1320 | * nil if it was omitted. Leave the value on the top of | |
1321 | * the stack after validating it. | |
1322 | */ | |
1323 | lua_getfield(state, 1, kwargs[i].za_name); | |
1324 | ||
1325 | type = lua_type(state, -1); | |
1326 | if (type != LUA_TNIL && type != kwargs[i].za_lua_type) { | |
1327 | zcp_args_error(state, fname, pargs, kwargs, | |
1328 | "kwarg '%s' wrong type (is '%s', expected '%s')", | |
1329 | kwargs[i].za_name, lua_typename(state, type), | |
1330 | lua_typename(state, kwargs[i].za_lua_type)); | |
1331 | panic("unreachable code"); | |
1332 | } | |
1333 | ||
1334 | /* | |
1335 | * Remove the keyword argument from the table. | |
1336 | */ | |
1337 | lua_pushnil(state); | |
1338 | lua_setfield(state, 1, kwargs[i].za_name); | |
1339 | } | |
1340 | ||
1341 | /* | |
1342 | * Any entries remaining in the table are invalid inputs, print | |
1343 | * an error message based on what the entry is. | |
1344 | */ | |
1345 | lua_pushnil(state); | |
1346 | if (lua_next(state, 1)) { | |
1347 | if (lua_isnumber(state, -2) && lua_tointeger(state, -2) > 0) { | |
1348 | zcp_args_error(state, fname, pargs, kwargs, | |
1349 | "too many positional arguments"); | |
1350 | } else if (lua_isstring(state, -2)) { | |
1351 | zcp_args_error(state, fname, pargs, kwargs, | |
1352 | "invalid kwarg '%s'", lua_tostring(state, -2)); | |
1353 | } else { | |
1354 | zcp_args_error(state, fname, pargs, kwargs, | |
1355 | "kwarg keys must be strings"); | |
1356 | } | |
1357 | panic("unreachable code"); | |
1358 | } | |
1359 | ||
1360 | lua_remove(state, 1); | |
1361 | } | |
1362 | ||
1363 | static void | |
1364 | zcp_parse_pos_args(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1365 | const zcp_arg_t *kwargs) | |
1366 | { | |
1367 | int i; | |
1368 | int type; | |
1369 | ||
1370 | for (i = 0; pargs[i].za_name != NULL; i++) { | |
1371 | type = lua_type(state, i + 1); | |
1372 | if (type == LUA_TNONE) { | |
1373 | zcp_args_error(state, fname, pargs, kwargs, | |
1374 | "too few arguments"); | |
1375 | panic("unreachable code"); | |
1376 | } else if (type != pargs[i].za_lua_type) { | |
1377 | zcp_args_error(state, fname, pargs, kwargs, | |
1378 | "arg %d wrong type (is '%s', expected '%s')", | |
1379 | i + 1, lua_typename(state, type), | |
1380 | lua_typename(state, pargs[i].za_lua_type)); | |
1381 | panic("unreachable code"); | |
1382 | } | |
1383 | } | |
1384 | if (lua_gettop(state) != i) { | |
1385 | zcp_args_error(state, fname, pargs, kwargs, | |
1386 | "too many positional arguments"); | |
1387 | panic("unreachable code"); | |
1388 | } | |
1389 | ||
1390 | for (i = 0; kwargs[i].za_name != NULL; i++) { | |
1391 | lua_pushnil(state); | |
1392 | } | |
1393 | } | |
1394 | ||
1395 | /* | |
1396 | * Checks the current Lua stack against an expected set of positional and | |
1397 | * keyword arguments. If the stack does not match the expected arguments | |
1398 | * aborts the current channel program with a useful error message, otherwise | |
1399 | * it re-arranges the stack so that it contains the positional arguments | |
1400 | * followed by the keyword argument values in declaration order. Any missing | |
1401 | * keyword argument will be represented by a nil value on the stack. | |
1402 | * | |
1403 | * If the stack contains exactly one argument of type LUA_TTABLE the curly | |
1404 | * braces calling convention is assumed, otherwise the stack is parsed for | |
1405 | * positional arguments only. | |
1406 | * | |
1407 | * This function should be used by every function callback. It should be called | |
1408 | * before the callback manipulates the Lua stack as it assumes the stack | |
1409 | * represents the function arguments. | |
1410 | */ | |
1411 | void | |
1412 | zcp_parse_args(lua_State *state, const char *fname, const zcp_arg_t *pargs, | |
1413 | const zcp_arg_t *kwargs) | |
1414 | { | |
1415 | if (lua_gettop(state) == 1 && lua_istable(state, 1)) { | |
1416 | zcp_parse_table_args(state, fname, pargs, kwargs); | |
1417 | } else { | |
1418 | zcp_parse_pos_args(state, fname, pargs, kwargs); | |
1419 | } | |
1420 | } |