xref: /freebsd/contrib/libucl/src/ucl_schema.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*
2  * Copyright (c) 2014, Vsevolod Stakhov
3  *
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *	 * Redistributions of source code must retain the above copyright
9  *	   notice, this list of conditions and the following disclaimer.
10  *	 * Redistributions in binary form must reproduce the above copyright
11  *	   notice, this list of conditions and the following disclaimer in the
12  *	   documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY AUTHOR ''AS IS'' AND ANY
15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "ucl.h"
27 #include "ucl_internal.h"
28 #include "tree.h"
29 #include "utlist.h"
30 #ifdef HAVE_STDARG_H
31 #include <stdarg.h>
32 #endif
33 #ifdef HAVE_STDIO_H
34 #include <stdio.h>
35 #endif
36 #ifdef HAVE_REGEX_H
37 #include <regex.h>
38 #endif
39 #ifdef HAVE_MATH_H
40 #include <math.h>
41 #endif
42 
43 static bool ucl_schema_validate (const ucl_object_t *schema,
44 		const ucl_object_t *obj, bool try_array,
45 		struct ucl_schema_error *err,
46 		const ucl_object_t *root,
47 		ucl_object_t *ext_ref);
48 
49 /*
50  * Create validation error
51  */
52 static void
53 ucl_schema_create_error (struct ucl_schema_error *err,
54 		enum ucl_schema_error_code code, const ucl_object_t *obj,
55 		const char *fmt, ...)
56 {
57 	va_list va;
58 
59 	if (err != NULL) {
60 		err->code = code;
61 		err->obj = obj;
62 		va_start (va, fmt);
63 		vsnprintf (err->msg, sizeof (err->msg), fmt, va);
64 		va_end (va);
65 	}
66 }
67 
68 /*
69  * Check whether we have a pattern specified
70  */
71 static const ucl_object_t *
72 ucl_schema_test_pattern (const ucl_object_t *obj, const char *pattern, bool recursive)
73 {
74 	const ucl_object_t *res = NULL;
75 #ifdef HAVE_REGEX_H
76 	regex_t reg;
77 	const ucl_object_t *elt;
78 	ucl_object_iter_t iter = NULL;
79 
80 	if (regcomp (&reg, pattern, REG_EXTENDED | REG_NOSUB) == 0) {
81 		if (recursive) {
82 			while ((elt = ucl_object_iterate (obj, &iter, true)) != NULL) {
83 				if (regexec (&reg, ucl_object_key (elt), 0, NULL, 0) == 0) {
84 					res = elt;
85 					break;
86 				}
87 			}
88 		} else {
89 			if (regexec (&reg, ucl_object_key (obj), 0, NULL, 0) == 0)
90 				res = obj;
91 		}
92 		regfree (&reg);
93 	}
94 #endif
95 	return res;
96 }
97 
98 /*
99  * Check dependencies for an object
100  */
101 static bool
102 ucl_schema_validate_dependencies (const ucl_object_t *deps,
103 		const ucl_object_t *obj, struct ucl_schema_error *err,
104 		const ucl_object_t *root,
105 		ucl_object_t *ext_ref)
106 {
107 	const ucl_object_t *elt, *cur, *cur_dep;
108 	ucl_object_iter_t iter = NULL, piter;
109 	bool ret = true;
110 
111 	while (ret && (cur = ucl_object_iterate (deps, &iter, true)) != NULL) {
112 		elt = ucl_object_lookup (obj, ucl_object_key (cur));
113 		if (elt != NULL) {
114 			/* Need to check dependencies */
115 			if (cur->type == UCL_ARRAY) {
116 				piter = NULL;
117 				while (ret && (cur_dep = ucl_object_iterate (cur, &piter, true)) != NULL) {
118 					if (ucl_object_lookup (obj, ucl_object_tostring (cur_dep)) == NULL) {
119 						ucl_schema_create_error (err, UCL_SCHEMA_MISSING_DEPENDENCY, elt,
120 								"dependency %s is missing for key %s",
121 								ucl_object_tostring (cur_dep), ucl_object_key (cur));
122 						ret = false;
123 						break;
124 					}
125 				}
126 			}
127 			else if (cur->type == UCL_OBJECT) {
128 				ret = ucl_schema_validate (cur, obj, true, err, root, ext_ref);
129 			}
130 		}
131 	}
132 
133 	return ret;
134 }
135 
136 /*
137  * Validate object
138  */
139 static bool
140 ucl_schema_validate_object (const ucl_object_t *schema,
141 		const ucl_object_t *obj, struct ucl_schema_error *err,
142 		const ucl_object_t *root,
143 		ucl_object_t *ext_ref)
144 {
145 	const ucl_object_t *elt, *prop, *found, *additional_schema = NULL,
146 			*required = NULL, *pat, *pelt;
147 	ucl_object_iter_t iter = NULL, piter = NULL;
148 	bool ret = true, allow_additional = true;
149 	int64_t minmax;
150 
151 	while (ret && (elt = ucl_object_iterate (schema, &iter, true)) != NULL) {
152 		if (elt->type == UCL_OBJECT &&
153 				strcmp (ucl_object_key (elt), "properties") == 0) {
154 			piter = NULL;
155 			while (ret && (prop = ucl_object_iterate (elt, &piter, true)) != NULL) {
156 				found = ucl_object_lookup (obj, ucl_object_key (prop));
157 				if (found) {
158 					ret = ucl_schema_validate (prop, found, true, err, root,
159 							ext_ref);
160 				}
161 			}
162 		}
163 		else if (strcmp (ucl_object_key (elt), "additionalProperties") == 0) {
164 			if (elt->type == UCL_BOOLEAN) {
165 				if (!ucl_object_toboolean (elt)) {
166 					/* Deny additional fields completely */
167 					allow_additional = false;
168 				}
169 			}
170 			else if (elt->type == UCL_OBJECT) {
171 				/* Define validator for additional fields */
172 				additional_schema = elt;
173 			}
174 			else {
175 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
176 						"additionalProperties attribute is invalid in schema");
177 				ret = false;
178 				break;
179 			}
180 		}
181 		else if (strcmp (ucl_object_key (elt), "required") == 0) {
182 			if (elt->type == UCL_ARRAY) {
183 				required = elt;
184 			}
185 			else {
186 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
187 						"required attribute is invalid in schema");
188 				ret = false;
189 				break;
190 			}
191 		}
192 		else if (strcmp (ucl_object_key (elt), "minProperties") == 0
193 				&& ucl_object_toint_safe (elt, &minmax)) {
194 			if (obj->len < minmax) {
195 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
196 						"object has not enough properties: %u, minimum is: %u",
197 						obj->len, (unsigned)minmax);
198 				ret = false;
199 				break;
200 			}
201 		}
202 		else if (strcmp (ucl_object_key (elt), "maxProperties") == 0
203 				&& ucl_object_toint_safe (elt, &minmax)) {
204 			if (obj->len > minmax) {
205 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
206 						"object has too many properties: %u, maximum is: %u",
207 						obj->len, (unsigned)minmax);
208 				ret = false;
209 				break;
210 			}
211 		}
212 		else if (strcmp (ucl_object_key (elt), "patternProperties") == 0) {
213 			const ucl_object_t *vobj;
214 			ucl_object_iter_t viter;
215 			piter = NULL;
216 			while (ret && (prop = ucl_object_iterate (elt, &piter, true)) != NULL) {
217 				viter = NULL;
218 				while (ret && (vobj = ucl_object_iterate (obj, &viter, true)) != NULL) {
219 					found = ucl_schema_test_pattern (vobj, ucl_object_key (prop), false);
220 					if (found) {
221 						ret = ucl_schema_validate (prop, found, true, err, root,
222 								ext_ref);
223 					}
224 				}
225 			}
226 		}
227 		else if (elt->type == UCL_OBJECT &&
228 				strcmp (ucl_object_key (elt), "dependencies") == 0) {
229 			ret = ucl_schema_validate_dependencies (elt, obj, err, root,
230 					ext_ref);
231 		}
232 	}
233 
234 	if (ret) {
235 		/* Additional properties */
236 		if (!allow_additional || additional_schema != NULL) {
237 			/* Check if we have exactly the same properties in schema and object */
238 			iter = NULL;
239 			prop = ucl_object_lookup (schema, "properties");
240 			while ((elt = ucl_object_iterate (obj, &iter, true)) != NULL) {
241 				found = ucl_object_lookup (prop, ucl_object_key (elt));
242 				if (found == NULL) {
243 					/* Try patternProperties */
244 					piter = NULL;
245 					pat = ucl_object_lookup (schema, "patternProperties");
246 					while ((pelt = ucl_object_iterate (pat, &piter, true)) != NULL) {
247 						found = ucl_schema_test_pattern (obj, ucl_object_key (pelt), true);
248 						if (found != NULL) {
249 							break;
250 						}
251 					}
252 				}
253 				if (found == NULL) {
254 					if (!allow_additional) {
255 						ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
256 								"object has non-allowed property %s",
257 								ucl_object_key (elt));
258 						ret = false;
259 						break;
260 					}
261 					else if (additional_schema != NULL) {
262 						if (!ucl_schema_validate (additional_schema, elt,
263 								true, err, root, ext_ref)) {
264 							ret = false;
265 							break;
266 						}
267 					}
268 				}
269 			}
270 		}
271 		/* Required properties */
272 		if (required != NULL) {
273 			iter = NULL;
274 			while ((elt = ucl_object_iterate (required, &iter, true)) != NULL) {
275 				if (ucl_object_lookup (obj, ucl_object_tostring (elt)) == NULL) {
276 					ucl_schema_create_error (err, UCL_SCHEMA_MISSING_PROPERTY, obj,
277 							"object has missing property %s",
278 							ucl_object_tostring (elt));
279 					ret = false;
280 					break;
281 				}
282 			}
283 		}
284 	}
285 
286 
287 	return ret;
288 }
289 
290 static bool
291 ucl_schema_validate_number (const ucl_object_t *schema,
292 		const ucl_object_t *obj, struct ucl_schema_error *err)
293 {
294 	const ucl_object_t *elt, *test;
295 	ucl_object_iter_t iter = NULL;
296 	bool ret = true, exclusive = false;
297 	double constraint, val;
298 	const double alpha = 1e-16;
299 
300 	while (ret && (elt = ucl_object_iterate (schema, &iter, true)) != NULL) {
301 		if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
302 				strcmp (ucl_object_key (elt), "multipleOf") == 0) {
303 			constraint = ucl_object_todouble (elt);
304 			if (constraint <= 0) {
305 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
306 						"multipleOf must be greater than zero");
307 				ret = false;
308 				break;
309 			}
310 			val = ucl_object_todouble (obj);
311 			if (fabs (remainder (val, constraint)) > alpha) {
312 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
313 						"number %.4f is not multiple of %.4f, remainder is %.7f",
314 						val, constraint);
315 				ret = false;
316 				break;
317 			}
318 		}
319 		else if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
320 			strcmp (ucl_object_key (elt), "maximum") == 0) {
321 			constraint = ucl_object_todouble (elt);
322 			test = ucl_object_lookup (schema, "exclusiveMaximum");
323 			if (test && test->type == UCL_BOOLEAN) {
324 				exclusive = ucl_object_toboolean (test);
325 			}
326 			val = ucl_object_todouble (obj);
327 			if (val > constraint || (exclusive && val >= constraint)) {
328 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
329 						"number is too big: %.3f, maximum is: %.3f",
330 						val, constraint);
331 				ret = false;
332 				break;
333 			}
334 		}
335 		else if ((elt->type == UCL_FLOAT || elt->type == UCL_INT) &&
336 				strcmp (ucl_object_key (elt), "minimum") == 0) {
337 			constraint = ucl_object_todouble (elt);
338 			test = ucl_object_lookup (schema, "exclusiveMinimum");
339 			if (test && test->type == UCL_BOOLEAN) {
340 				exclusive = ucl_object_toboolean (test);
341 			}
342 			val = ucl_object_todouble (obj);
343 			if (val < constraint || (exclusive && val <= constraint)) {
344 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
345 						"number is too small: %.3f, minimum is: %.3f",
346 						val, constraint);
347 				ret = false;
348 				break;
349 			}
350 		}
351 	}
352 
353 	return ret;
354 }
355 
356 static bool
357 ucl_schema_validate_string (const ucl_object_t *schema,
358 		const ucl_object_t *obj, struct ucl_schema_error *err)
359 {
360 	const ucl_object_t *elt;
361 	ucl_object_iter_t iter = NULL;
362 	bool ret = true;
363 	int64_t constraint;
364 #ifdef HAVE_REGEX_H
365 	regex_t re;
366 #endif
367 
368 	while (ret && (elt = ucl_object_iterate (schema, &iter, true)) != NULL) {
369 		if (elt->type == UCL_INT &&
370 			strcmp (ucl_object_key (elt), "maxLength") == 0) {
371 			constraint = ucl_object_toint (elt);
372 			if (obj->len > constraint) {
373 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
374 						"string is too big: %.3f, maximum is: %.3f",
375 						obj->len, constraint);
376 				ret = false;
377 				break;
378 			}
379 		}
380 		else if (elt->type == UCL_INT &&
381 				strcmp (ucl_object_key (elt), "minLength") == 0) {
382 			constraint = ucl_object_toint (elt);
383 			if (obj->len < constraint) {
384 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
385 						"string is too short: %.3f, minimum is: %.3f",
386 						obj->len, constraint);
387 				ret = false;
388 				break;
389 			}
390 		}
391 #ifdef HAVE_REGEX_H
392 		else if (elt->type == UCL_STRING &&
393 				strcmp (ucl_object_key (elt), "pattern") == 0) {
394 			if (regcomp (&re, ucl_object_tostring (elt),
395 					REG_EXTENDED | REG_NOSUB) != 0) {
396 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
397 						"cannot compile pattern %s", ucl_object_tostring (elt));
398 				ret = false;
399 				break;
400 			}
401 			if (regexec (&re, ucl_object_tostring (obj), 0, NULL, 0) != 0) {
402 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
403 						"string doesn't match regexp %s",
404 						ucl_object_tostring (elt));
405 				ret = false;
406 			}
407 			regfree (&re);
408 		}
409 #endif
410 	}
411 
412 	return ret;
413 }
414 
415 struct ucl_compare_node {
416 	const ucl_object_t *obj;
417 	TREE_ENTRY(ucl_compare_node) link;
418 	struct ucl_compare_node *next;
419 };
420 
421 typedef TREE_HEAD(_tree, ucl_compare_node) ucl_compare_tree_t;
422 
423 TREE_DEFINE(ucl_compare_node, link)
424 
425 static int
426 ucl_schema_elt_compare (struct ucl_compare_node *n1, struct ucl_compare_node *n2)
427 {
428 	const ucl_object_t *o1 = n1->obj, *o2 = n2->obj;
429 
430 	return ucl_object_compare (o1, o2);
431 }
432 
433 static bool
434 ucl_schema_array_is_unique (const ucl_object_t *obj, struct ucl_schema_error *err)
435 {
436 	ucl_compare_tree_t tree = TREE_INITIALIZER (ucl_schema_elt_compare);
437 	ucl_object_iter_t iter = NULL;
438 	const ucl_object_t *elt;
439 	struct ucl_compare_node *node, test, *nodes = NULL, *tmp;
440 	bool ret = true;
441 
442 	while ((elt = ucl_object_iterate (obj, &iter, true)) != NULL) {
443 		test.obj = elt;
444 		node = TREE_FIND (&tree, ucl_compare_node, link, &test);
445 		if (node != NULL) {
446 			ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, elt,
447 					"duplicate values detected while uniqueItems is true");
448 			ret = false;
449 			break;
450 		}
451 		node = calloc (1, sizeof (*node));
452 		if (node == NULL) {
453 			ucl_schema_create_error (err, UCL_SCHEMA_UNKNOWN, elt,
454 					"cannot allocate tree node");
455 			ret = false;
456 			break;
457 		}
458 		node->obj = elt;
459 		TREE_INSERT (&tree, ucl_compare_node, link, node);
460 		LL_PREPEND (nodes, node);
461 	}
462 
463 	LL_FOREACH_SAFE (nodes, node, tmp) {
464 		free (node);
465 	}
466 
467 	return ret;
468 }
469 
470 static bool
471 ucl_schema_validate_array (const ucl_object_t *schema,
472 		const ucl_object_t *obj, struct ucl_schema_error *err,
473 		const ucl_object_t *root,
474 		ucl_object_t *ext_ref)
475 {
476 	const ucl_object_t *elt, *it, *found, *additional_schema = NULL,
477 			*first_unvalidated = NULL;
478 	ucl_object_iter_t iter = NULL, piter = NULL;
479 	bool ret = true, allow_additional = true, need_unique = false;
480 	int64_t minmax;
481 	unsigned int idx = 0;
482 
483 	while (ret && (elt = ucl_object_iterate (schema, &iter, true)) != NULL) {
484 		if (strcmp (ucl_object_key (elt), "items") == 0) {
485 			if (elt->type == UCL_ARRAY) {
486 				found = ucl_array_head (obj);
487 				while (ret && (it = ucl_object_iterate (elt, &piter, true)) != NULL) {
488 					if (found) {
489 						ret = ucl_schema_validate (it, found, false, err,
490 								root, ext_ref);
491 						found = ucl_array_find_index (obj, ++idx);
492 					}
493 				}
494 				if (found != NULL) {
495 					/* The first element that is not validated */
496 					first_unvalidated = found;
497 				}
498 			}
499 			else if (elt->type == UCL_OBJECT) {
500 				/* Validate all items using the specified schema */
501 				while (ret && (it = ucl_object_iterate (obj, &piter, true)) != NULL) {
502 					ret = ucl_schema_validate (elt, it, false, err, root,
503 							ext_ref);
504 				}
505 			}
506 			else {
507 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
508 						"items attribute is invalid in schema");
509 				ret = false;
510 				break;
511 			}
512 		}
513 		else if (strcmp (ucl_object_key (elt), "additionalItems") == 0) {
514 			if (elt->type == UCL_BOOLEAN) {
515 				if (!ucl_object_toboolean (elt)) {
516 					/* Deny additional fields completely */
517 					allow_additional = false;
518 				}
519 			}
520 			else if (elt->type == UCL_OBJECT) {
521 				/* Define validator for additional fields */
522 				additional_schema = elt;
523 			}
524 			else {
525 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, elt,
526 						"additionalItems attribute is invalid in schema");
527 				ret = false;
528 				break;
529 			}
530 		}
531 		else if (elt->type == UCL_BOOLEAN &&
532 				strcmp (ucl_object_key (elt), "uniqueItems") == 0) {
533 			need_unique = ucl_object_toboolean (elt);
534 		}
535 		else if (strcmp (ucl_object_key (elt), "minItems") == 0
536 				&& ucl_object_toint_safe (elt, &minmax)) {
537 			if (obj->len < minmax) {
538 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
539 						"array has not enough items: %u, minimum is: %u",
540 						obj->len, (unsigned)minmax);
541 				ret = false;
542 				break;
543 			}
544 		}
545 		else if (strcmp (ucl_object_key (elt), "maxItems") == 0
546 				&& ucl_object_toint_safe (elt, &minmax)) {
547 			if (obj->len > minmax) {
548 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
549 						"array has too many items: %u, maximum is: %u",
550 						obj->len, (unsigned)minmax);
551 				ret = false;
552 				break;
553 			}
554 		}
555 	}
556 
557 	if (ret) {
558 		/* Additional properties */
559 		if (!allow_additional || additional_schema != NULL) {
560 			if (first_unvalidated != NULL) {
561 				if (!allow_additional) {
562 					ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
563 							"array has undefined item");
564 					ret = false;
565 				}
566 				else if (additional_schema != NULL) {
567 					elt = ucl_array_find_index (obj, idx);
568 					while (elt) {
569 						if (!ucl_schema_validate (additional_schema, elt, false,
570 								err, root, ext_ref)) {
571 							ret = false;
572 							break;
573 						}
574 						elt = ucl_array_find_index (obj, idx ++);
575 					}
576 				}
577 			}
578 		}
579 		/* Required properties */
580 		if (ret && need_unique) {
581 			ret = ucl_schema_array_is_unique (obj, err);
582 		}
583 	}
584 
585 	return ret;
586 }
587 
588 /*
589  * Returns whether this object is allowed for this type
590  */
591 static bool
592 ucl_schema_type_is_allowed (const ucl_object_t *type, const ucl_object_t *obj,
593 		struct ucl_schema_error *err)
594 {
595 	ucl_object_iter_t iter = NULL;
596 	const ucl_object_t *elt;
597 	const char *type_str;
598 	ucl_type_t t;
599 
600 	if (type == NULL) {
601 		/* Any type is allowed */
602 		return true;
603 	}
604 
605 	if (type->type == UCL_ARRAY) {
606 		/* One of allowed types */
607 		while ((elt = ucl_object_iterate (type, &iter, true)) != NULL) {
608 			if (ucl_schema_type_is_allowed (elt, obj, err)) {
609 				return true;
610 			}
611 		}
612 	}
613 	else if (type->type == UCL_STRING) {
614 		type_str = ucl_object_tostring (type);
615 		if (!ucl_object_string_to_type (type_str, &t)) {
616 			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, type,
617 					"Type attribute is invalid in schema");
618 			return false;
619 		}
620 		if (obj->type != t) {
621 			/* Some types are actually compatible */
622 			if (obj->type == UCL_TIME && t == UCL_FLOAT) {
623 				return true;
624 			}
625 			else if (obj->type == UCL_INT && t == UCL_FLOAT) {
626 				return true;
627 			}
628 			else {
629 				ucl_schema_create_error (err, UCL_SCHEMA_TYPE_MISMATCH, obj,
630 						"Invalid type of %s, expected %s",
631 						ucl_object_type_to_string (obj->type),
632 						ucl_object_type_to_string (t));
633 			}
634 		}
635 		else {
636 			/* Types are equal */
637 			return true;
638 		}
639 	}
640 
641 	return false;
642 }
643 
644 /*
645  * Check if object is equal to one of elements of enum
646  */
647 static bool
648 ucl_schema_validate_enum (const ucl_object_t *en, const ucl_object_t *obj,
649 		struct ucl_schema_error *err)
650 {
651 	ucl_object_iter_t iter = NULL;
652 	const ucl_object_t *elt;
653 	bool ret = false;
654 
655 	while ((elt = ucl_object_iterate (en, &iter, true)) != NULL) {
656 		if (ucl_object_compare (elt, obj) == 0) {
657 			ret = true;
658 			break;
659 		}
660 	}
661 
662 	if (!ret) {
663 		ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
664 				"object is not one of enumerated patterns");
665 	}
666 
667 	return ret;
668 }
669 
670 
671 /*
672  * Check a single ref component
673  */
674 static const ucl_object_t *
675 ucl_schema_resolve_ref_component (const ucl_object_t *cur,
676 		const char *refc, int len,
677 		struct ucl_schema_error *err)
678 {
679 	const ucl_object_t *res = NULL;
680 	char *err_str;
681 	int num, i;
682 
683 	if (cur->type == UCL_OBJECT) {
684 		/* Find a key inside an object */
685 		res = ucl_object_lookup_len (cur, refc, len);
686 		if (res == NULL) {
687 			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
688 					"reference %s is invalid, missing path component", refc);
689 			return NULL;
690 		}
691 	}
692 	else if (cur->type == UCL_ARRAY) {
693 		/* We must figure out a number inside array */
694 		num = strtoul (refc, &err_str, 10);
695 		if (err_str != NULL && *err_str != '/' && *err_str != '\0') {
696 			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
697 					"reference %s is invalid, invalid item number", refc);
698 			return NULL;
699 		}
700 		res = ucl_array_head (cur);
701 		i = 0;
702 		while (res != NULL) {
703 			if (i == num) {
704 				break;
705 			}
706 			res = res->next;
707 		}
708 		if (res == NULL) {
709 			ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, cur,
710 					"reference %s is invalid, item number %d does not exist",
711 					refc, num);
712 			return NULL;
713 		}
714 	}
715 	else {
716 		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
717 				"reference %s is invalid, contains primitive object in the path",
718 				refc);
719 		return NULL;
720 	}
721 
722 	return res;
723 }
724 /*
725  * Find reference schema
726  */
727 static const ucl_object_t *
728 ucl_schema_resolve_ref (const ucl_object_t *root, const char *ref,
729 		struct ucl_schema_error *err, ucl_object_t *ext_ref,
730 		ucl_object_t const ** nroot)
731 {
732 	UT_string *url_err = NULL;
733 	struct ucl_parser *parser;
734 	const ucl_object_t *res = NULL, *ext_obj = NULL;
735 	ucl_object_t *url_obj;
736 	const char *p, *c, *hash_ptr = NULL;
737 	char *url_copy = NULL;
738 	unsigned char *url_buf;
739 	size_t url_buflen;
740 
741 	if (ref[0] != '#') {
742 		hash_ptr = strrchr (ref, '#');
743 
744 		if (hash_ptr) {
745 			url_copy = malloc (hash_ptr - ref + 1);
746 
747 			if (url_copy == NULL) {
748 				ucl_schema_create_error (err, UCL_SCHEMA_INTERNAL_ERROR, root,
749 						"cannot allocate memory");
750 				return NULL;
751 			}
752 
753 			ucl_strlcpy (url_copy, ref, hash_ptr - ref + 1);
754 			p = url_copy;
755 		}
756 		else {
757 			/* Full URL */
758 			p = ref;
759 		}
760 
761 		ext_obj = ucl_object_lookup (ext_ref, p);
762 
763 		if (ext_obj == NULL) {
764 			if (ucl_strnstr (p, "://", strlen (p)) != NULL) {
765 				if (!ucl_fetch_url (p, &url_buf, &url_buflen, &url_err, true)) {
766 
767 					ucl_schema_create_error (err,
768 							UCL_SCHEMA_INVALID_SCHEMA,
769 							root,
770 							"cannot fetch reference %s: %s",
771 							p,
772 							url_err != NULL ? utstring_body (url_err)
773 											: "unknown");
774 					free (url_copy);
775 
776 					return NULL;
777 				}
778 			}
779 			else {
780 				if (!ucl_fetch_file (p, &url_buf, &url_buflen, &url_err,
781 						true)) {
782 					ucl_schema_create_error (err,
783 							UCL_SCHEMA_INVALID_SCHEMA,
784 							root,
785 							"cannot fetch reference %s: %s",
786 							p,
787 							url_err != NULL ? utstring_body (url_err)
788 											: "unknown");
789 					free (url_copy);
790 
791 					return NULL;
792 				}
793 			}
794 
795 			parser = ucl_parser_new (0);
796 
797 			if (!ucl_parser_add_chunk (parser, url_buf, url_buflen)) {
798 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, root,
799 						"cannot fetch reference %s: %s", p,
800 						ucl_parser_get_error (parser));
801 				ucl_parser_free (parser);
802 				free (url_copy);
803 
804 				return NULL;
805 			}
806 
807 			url_obj = ucl_parser_get_object (parser);
808 			ext_obj = url_obj;
809 			ucl_object_insert_key (ext_ref, url_obj, p, 0, true);
810 			free (url_buf);
811 		}
812 
813 		free (url_copy);
814 
815 		if (hash_ptr) {
816 			p = hash_ptr + 1;
817 		}
818 		else {
819 			p = "";
820 		}
821 	}
822 	else {
823 		p = ref + 1;
824 	}
825 
826 	res = ext_obj != NULL ? ext_obj : root;
827 	*nroot = res;
828 
829 	if (*p == '/') {
830 		p++;
831 	}
832 	else if (*p == '\0') {
833 		return res;
834 	}
835 
836 	c = p;
837 
838 	while (*p != '\0') {
839 		if (*p == '/') {
840 			if (p - c == 0) {
841 				ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
842 						"reference %s is invalid, empty path component", ref);
843 				return NULL;
844 			}
845 			/* Now we have some url part, so we need to figure out where we are */
846 			res = ucl_schema_resolve_ref_component (res, c, p - c, err);
847 			if (res == NULL) {
848 				return NULL;
849 			}
850 			c = p + 1;
851 		}
852 		p ++;
853 	}
854 
855 	if (p - c != 0) {
856 		res = ucl_schema_resolve_ref_component (res, c, p - c, err);
857 	}
858 
859 	if (res == NULL || res->type != UCL_OBJECT) {
860 		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, res,
861 				"reference %s is invalid, cannot find specified object",
862 				ref);
863 		return NULL;
864 	}
865 
866 	return res;
867 }
868 
869 static bool
870 ucl_schema_validate_values (const ucl_object_t *schema, const ucl_object_t *obj,
871 		struct ucl_schema_error *err)
872 {
873 	const ucl_object_t *elt, *cur;
874 	int64_t constraint, i;
875 
876 	elt = ucl_object_lookup (schema, "maxValues");
877 	if (elt != NULL && elt->type == UCL_INT) {
878 		constraint = ucl_object_toint (elt);
879 		cur = obj;
880 		i = 0;
881 		while (cur) {
882 			if (i > constraint) {
883 				ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
884 					"object has more values than defined: %ld",
885 					(long int)constraint);
886 				return false;
887 			}
888 			i ++;
889 			cur = cur->next;
890 		}
891 	}
892 	elt = ucl_object_lookup (schema, "minValues");
893 	if (elt != NULL && elt->type == UCL_INT) {
894 		constraint = ucl_object_toint (elt);
895 		cur = obj;
896 		i = 0;
897 		while (cur) {
898 			if (i >= constraint) {
899 				break;
900 			}
901 			i ++;
902 			cur = cur->next;
903 		}
904 		if (i < constraint) {
905 			ucl_schema_create_error (err, UCL_SCHEMA_CONSTRAINT, obj,
906 					"object has less values than defined: %ld",
907 					(long int)constraint);
908 			return false;
909 		}
910 	}
911 
912 	return true;
913 }
914 
915 static bool
916 ucl_schema_validate (const ucl_object_t *schema,
917 		const ucl_object_t *obj, bool try_array,
918 		struct ucl_schema_error *err,
919 		const ucl_object_t *root,
920 		ucl_object_t *external_refs)
921 {
922 	const ucl_object_t *elt, *cur, *ref_root;
923 	ucl_object_iter_t iter = NULL;
924 	bool ret;
925 
926 	if (schema->type != UCL_OBJECT) {
927 		ucl_schema_create_error (err, UCL_SCHEMA_INVALID_SCHEMA, schema,
928 				"schema is %s instead of object",
929 				ucl_object_type_to_string (schema->type));
930 		return false;
931 	}
932 
933 	if (try_array) {
934 		/*
935 		 * Special case for multiple values
936 		 */
937 		if (!ucl_schema_validate_values (schema, obj, err)) {
938 			return false;
939 		}
940 		LL_FOREACH (obj, cur) {
941 			if (!ucl_schema_validate (schema, cur, false, err, root, external_refs)) {
942 				return false;
943 			}
944 		}
945 		return true;
946 	}
947 
948 	elt = ucl_object_lookup (schema, "enum");
949 	if (elt != NULL && elt->type == UCL_ARRAY) {
950 		if (!ucl_schema_validate_enum (elt, obj, err)) {
951 			return false;
952 		}
953 	}
954 
955 	elt = ucl_object_lookup (schema, "allOf");
956 	if (elt != NULL && elt->type == UCL_ARRAY) {
957 		iter = NULL;
958 		while ((cur = ucl_object_iterate (elt, &iter, true)) != NULL) {
959 			ret = ucl_schema_validate (cur, obj, true, err, root, external_refs);
960 			if (!ret) {
961 				return false;
962 			}
963 		}
964 	}
965 
966 	elt = ucl_object_lookup (schema, "anyOf");
967 	if (elt != NULL && elt->type == UCL_ARRAY) {
968 		iter = NULL;
969 		while ((cur = ucl_object_iterate (elt, &iter, true)) != NULL) {
970 			ret = ucl_schema_validate (cur, obj, true, err, root, external_refs);
971 			if (ret) {
972 				break;
973 			}
974 		}
975 		if (!ret) {
976 			return false;
977 		}
978 		else {
979 			/* Reset error */
980 			err->code = UCL_SCHEMA_OK;
981 		}
982 	}
983 
984 	elt = ucl_object_lookup (schema, "oneOf");
985 	if (elt != NULL && elt->type == UCL_ARRAY) {
986 		iter = NULL;
987 		ret = false;
988 		while ((cur = ucl_object_iterate (elt, &iter, true)) != NULL) {
989 			if (!ret) {
990 				ret = ucl_schema_validate (cur, obj, true, err, root, external_refs);
991 			}
992 			else if (ucl_schema_validate (cur, obj, true, err, root, external_refs)) {
993 				ret = false;
994 				break;
995 			}
996 		}
997 		if (!ret) {
998 			return false;
999 		}
1000 	}
1001 
1002 	elt = ucl_object_lookup (schema, "not");
1003 	if (elt != NULL && elt->type == UCL_OBJECT) {
1004 		if (ucl_schema_validate (elt, obj, true, err, root, external_refs)) {
1005 			return false;
1006 		}
1007 		else {
1008 			/* Reset error */
1009 			err->code = UCL_SCHEMA_OK;
1010 		}
1011 	}
1012 
1013 	elt = ucl_object_lookup (schema, "$ref");
1014 	if (elt != NULL) {
1015 		ref_root = root;
1016 		cur = ucl_schema_resolve_ref (root, ucl_object_tostring (elt),
1017 				err, external_refs, &ref_root);
1018 
1019 		if (cur == NULL) {
1020 			return false;
1021 		}
1022 		if (!ucl_schema_validate (cur, obj, try_array, err, ref_root,
1023 				external_refs)) {
1024 			return false;
1025 		}
1026 	}
1027 
1028 	elt = ucl_object_lookup (schema, "type");
1029 	if (!ucl_schema_type_is_allowed (elt, obj, err)) {
1030 		return false;
1031 	}
1032 
1033 	switch (obj->type) {
1034 	case UCL_OBJECT:
1035 		return ucl_schema_validate_object (schema, obj, err, root, external_refs);
1036 		break;
1037 	case UCL_ARRAY:
1038 		return ucl_schema_validate_array (schema, obj, err, root, external_refs);
1039 		break;
1040 	case UCL_INT:
1041 	case UCL_FLOAT:
1042 		return ucl_schema_validate_number (schema, obj, err);
1043 		break;
1044 	case UCL_STRING:
1045 		return ucl_schema_validate_string (schema, obj, err);
1046 		break;
1047 	default:
1048 		break;
1049 	}
1050 
1051 	return true;
1052 }
1053 
1054 bool
1055 ucl_object_validate (const ucl_object_t *schema,
1056 		const ucl_object_t *obj, struct ucl_schema_error *err)
1057 {
1058 	return ucl_object_validate_root_ext (schema, obj, schema, NULL, err);
1059 }
1060 
1061 bool
1062 ucl_object_validate_root (const ucl_object_t *schema,
1063 		const ucl_object_t *obj,
1064 		const ucl_object_t *root,
1065 		struct ucl_schema_error *err)
1066 {
1067 	return ucl_object_validate_root_ext (schema, obj, root, NULL, err);
1068 }
1069 
1070 bool
1071 ucl_object_validate_root_ext (const ucl_object_t *schema,
1072 		const ucl_object_t *obj,
1073 		const ucl_object_t *root,
1074 		ucl_object_t *ext_refs,
1075 		struct ucl_schema_error *err)
1076 {
1077 	bool ret, need_unref = false;
1078 
1079 	if (ext_refs == NULL) {
1080 		ext_refs = ucl_object_typed_new (UCL_OBJECT);
1081 		need_unref = true;
1082 	}
1083 
1084 	ret = ucl_schema_validate (schema, obj, true, err, root, ext_refs);
1085 
1086 	if (need_unref) {
1087 		ucl_object_unref (ext_refs);
1088 	}
1089 
1090 	return ret;
1091 }
1092