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e0840f11 | 1 | /* |
f1c16a85 | 2 | * Copyright (c) 2015, 2016 Nicira, Inc. |
e0840f11 BP |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
5 | * you may not use this file except in compliance with the License. | |
6 | * You may obtain a copy of the License at: | |
7 | * | |
8 | * http://www.apache.org/licenses/LICENSE-2.0 | |
9 | * | |
10 | * Unless required by applicable law or agreed to in writing, software | |
11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
13 | * See the License for the specific language governing permissions and | |
14 | * limitations under the License. | |
15 | */ | |
16 | ||
17 | #include <config.h> | |
f4248336 | 18 | #include "byte-order.h" |
ee89ea7b | 19 | #include "openvswitch/json.h" |
b4970837 | 20 | #include "logical-fields.h" |
b598f214 | 21 | #include "openvswitch/dynamic-string.h" |
e29747e4 | 22 | #include "openvswitch/match.h" |
b598f214 BW |
23 | #include "openvswitch/ofp-actions.h" |
24 | #include "openvswitch/vlog.h" | |
ee89ea7b | 25 | #include "openvswitch/shash.h" |
8b2ed684 AR |
26 | #include "ovn/expr.h" |
27 | #include "ovn/lex.h" | |
f386a8a7 | 28 | #include "simap.h" |
9d4aecca | 29 | #include "sset.h" |
ee89ea7b | 30 | #include "util.h" |
e0840f11 BP |
31 | |
32 | VLOG_DEFINE_THIS_MODULE(expr); | |
33 | \f | |
34 | /* Returns the name of measurement level 'level'. */ | |
35 | const char * | |
36 | expr_level_to_string(enum expr_level level) | |
37 | { | |
38 | switch (level) { | |
39 | case EXPR_L_NOMINAL: return "nominal"; | |
40 | case EXPR_L_BOOLEAN: return "Boolean"; | |
41 | case EXPR_L_ORDINAL: return "ordinal"; | |
42 | default: OVS_NOT_REACHED(); | |
43 | } | |
44 | } | |
45 | \f | |
46 | /* Relational operators. */ | |
47 | ||
48 | /* Returns a string form of relational operator 'relop'. */ | |
49 | const char * | |
50 | expr_relop_to_string(enum expr_relop relop) | |
51 | { | |
52 | switch (relop) { | |
53 | case EXPR_R_EQ: return "=="; | |
54 | case EXPR_R_NE: return "!="; | |
55 | case EXPR_R_LT: return "<"; | |
56 | case EXPR_R_LE: return "<="; | |
57 | case EXPR_R_GT: return ">"; | |
58 | case EXPR_R_GE: return ">="; | |
59 | default: OVS_NOT_REACHED(); | |
60 | } | |
61 | } | |
62 | ||
63 | bool | |
64 | expr_relop_from_token(enum lex_type type, enum expr_relop *relop) | |
65 | { | |
66 | enum expr_relop r; | |
67 | ||
68 | switch ((int) type) { | |
69 | case LEX_T_EQ: r = EXPR_R_EQ; break; | |
70 | case LEX_T_NE: r = EXPR_R_NE; break; | |
71 | case LEX_T_LT: r = EXPR_R_LT; break; | |
72 | case LEX_T_LE: r = EXPR_R_LE; break; | |
73 | case LEX_T_GT: r = EXPR_R_GT; break; | |
74 | case LEX_T_GE: r = EXPR_R_GE; break; | |
75 | default: return false; | |
76 | } | |
77 | ||
78 | if (relop) { | |
79 | *relop = r; | |
80 | } | |
81 | return true; | |
82 | } | |
83 | ||
84 | /* Returns the relational operator that 'relop' becomes if you turn the | |
85 | * relation's operands around, e.g. EXPR_R_EQ does not change because "a == b" | |
86 | * and "b == a" are equivalent, but EXPR_R_LE becomes EXPR_R_GE because "a <= | |
87 | * b" is equivalent to "b >= a". */ | |
88 | static enum expr_relop | |
89 | expr_relop_turn(enum expr_relop relop) | |
90 | { | |
91 | switch (relop) { | |
92 | case EXPR_R_EQ: return EXPR_R_EQ; | |
93 | case EXPR_R_NE: return EXPR_R_NE; | |
94 | case EXPR_R_LT: return EXPR_R_GT; | |
95 | case EXPR_R_LE: return EXPR_R_GE; | |
96 | case EXPR_R_GT: return EXPR_R_LT; | |
97 | case EXPR_R_GE: return EXPR_R_LE; | |
98 | default: OVS_NOT_REACHED(); | |
99 | } | |
100 | } | |
101 | ||
102 | /* Returns the relational operator that is the opposite of 'relop'. */ | |
103 | static enum expr_relop | |
104 | expr_relop_invert(enum expr_relop relop) | |
105 | { | |
106 | switch (relop) { | |
107 | case EXPR_R_EQ: return EXPR_R_NE; | |
108 | case EXPR_R_NE: return EXPR_R_EQ; | |
109 | case EXPR_R_LT: return EXPR_R_GE; | |
110 | case EXPR_R_LE: return EXPR_R_GT; | |
111 | case EXPR_R_GT: return EXPR_R_LE; | |
112 | case EXPR_R_GE: return EXPR_R_LT; | |
113 | default: OVS_NOT_REACHED(); | |
114 | } | |
115 | } | |
116 | \f | |
117 | /* Constructing and manipulating expressions. */ | |
118 | ||
119 | /* Creates and returns a logical AND or OR expression (according to 'type', | |
120 | * which must be EXPR_T_AND or EXPR_T_OR) that initially has no | |
121 | * sub-expressions. (To satisfy the invariants for expressions, the caller | |
122 | * must add at least two sub-expressions whose types are different from | |
123 | * 'type'.) */ | |
124 | struct expr * | |
125 | expr_create_andor(enum expr_type type) | |
126 | { | |
127 | struct expr *e = xmalloc(sizeof *e); | |
128 | e->type = type; | |
417e7e66 | 129 | ovs_list_init(&e->andor); |
e0840f11 BP |
130 | return e; |
131 | } | |
132 | ||
133 | /* Returns a logical AND or OR expression (according to 'type', which must be | |
134 | * EXPR_T_AND or EXPR_T_OR) whose sub-expressions are 'a' and 'b', with some | |
135 | * flexibility: | |
136 | * | |
137 | * - If 'a' or 'b' is NULL, just returns the other one (which means that if | |
138 | * that other one is not of the given 'type', then the returned | |
139 | * expression is not either). | |
140 | * | |
141 | * - If 'a' or 'b', or both, have type 'type', then they are combined into | |
142 | * a single node that satisfies the invariants for expressions. */ | |
143 | struct expr * | |
144 | expr_combine(enum expr_type type, struct expr *a, struct expr *b) | |
145 | { | |
146 | if (!a) { | |
147 | return b; | |
148 | } else if (!b) { | |
149 | return a; | |
150 | } else if (a->type == type) { | |
151 | if (b->type == type) { | |
417e7e66 | 152 | ovs_list_splice(&a->andor, b->andor.next, &b->andor); |
e0840f11 BP |
153 | free(b); |
154 | } else { | |
417e7e66 | 155 | ovs_list_push_back(&a->andor, &b->node); |
e0840f11 BP |
156 | } |
157 | return a; | |
158 | } else if (b->type == type) { | |
417e7e66 | 159 | ovs_list_push_front(&b->andor, &a->node); |
e0840f11 BP |
160 | return b; |
161 | } else { | |
162 | struct expr *e = expr_create_andor(type); | |
417e7e66 BW |
163 | ovs_list_push_back(&e->andor, &a->node); |
164 | ovs_list_push_back(&e->andor, &b->node); | |
e0840f11 BP |
165 | return e; |
166 | } | |
167 | } | |
168 | ||
169 | static void | |
170 | expr_insert_andor(struct expr *andor, struct expr *before, struct expr *new) | |
171 | { | |
172 | if (new->type == andor->type) { | |
173 | if (andor->type == EXPR_T_AND) { | |
174 | /* Conjunction junction, what's your function? */ | |
175 | } | |
417e7e66 | 176 | ovs_list_splice(&before->node, new->andor.next, &new->andor); |
e0840f11 BP |
177 | free(new); |
178 | } else { | |
417e7e66 | 179 | ovs_list_insert(&before->node, &new->node); |
e0840f11 BP |
180 | } |
181 | } | |
182 | ||
183 | /* Returns an EXPR_T_BOOLEAN expression with value 'b'. */ | |
184 | struct expr * | |
185 | expr_create_boolean(bool b) | |
186 | { | |
187 | struct expr *e = xmalloc(sizeof *e); | |
188 | e->type = EXPR_T_BOOLEAN; | |
189 | e->boolean = b; | |
190 | return e; | |
191 | } | |
192 | ||
193 | static void | |
194 | expr_not(struct expr *expr) | |
195 | { | |
196 | struct expr *sub; | |
197 | ||
198 | switch (expr->type) { | |
199 | case EXPR_T_CMP: | |
200 | expr->cmp.relop = expr_relop_invert(expr->cmp.relop); | |
201 | break; | |
202 | ||
203 | case EXPR_T_AND: | |
204 | case EXPR_T_OR: | |
205 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
206 | expr_not(sub); | |
207 | } | |
208 | expr->type = expr->type == EXPR_T_AND ? EXPR_T_OR : EXPR_T_AND; | |
209 | break; | |
210 | ||
211 | case EXPR_T_BOOLEAN: | |
212 | expr->boolean = !expr->boolean; | |
213 | break; | |
214 | default: | |
215 | OVS_NOT_REACHED(); | |
216 | } | |
217 | } | |
218 | ||
219 | static struct expr * | |
220 | expr_fix_andor(struct expr *expr, bool short_circuit) | |
221 | { | |
222 | struct expr *sub, *next; | |
223 | ||
224 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
225 | if (sub->type == EXPR_T_BOOLEAN) { | |
226 | if (sub->boolean == short_circuit) { | |
227 | expr_destroy(expr); | |
228 | return expr_create_boolean(short_circuit); | |
229 | } else { | |
417e7e66 | 230 | ovs_list_remove(&sub->node); |
e0840f11 BP |
231 | expr_destroy(sub); |
232 | } | |
233 | } | |
234 | } | |
235 | ||
417e7e66 BW |
236 | if (ovs_list_is_short(&expr->andor)) { |
237 | if (ovs_list_is_empty(&expr->andor)) { | |
e0840f11 BP |
238 | free(expr); |
239 | return expr_create_boolean(!short_circuit); | |
240 | } else { | |
417e7e66 | 241 | sub = expr_from_node(ovs_list_front(&expr->andor)); |
e0840f11 BP |
242 | free(expr); |
243 | return sub; | |
244 | } | |
245 | } else { | |
246 | return expr; | |
247 | } | |
248 | } | |
249 | ||
fd477c6e BP |
250 | /* Returns 'expr' modified so that top-level oddities are fixed up: |
251 | * | |
252 | * - Eliminates any EXPR_T_BOOLEAN operands at the top level. | |
253 | * | |
254 | * - Replaces one-operand EXPR_T_AND or EXPR_T_OR by its subexpression. */ | |
e0840f11 BP |
255 | static struct expr * |
256 | expr_fix(struct expr *expr) | |
257 | { | |
258 | switch (expr->type) { | |
259 | case EXPR_T_CMP: | |
260 | return expr; | |
261 | ||
262 | case EXPR_T_AND: | |
263 | return expr_fix_andor(expr, false); | |
264 | ||
265 | case EXPR_T_OR: | |
266 | return expr_fix_andor(expr, true); | |
267 | ||
268 | case EXPR_T_BOOLEAN: | |
269 | return expr; | |
270 | ||
271 | default: | |
272 | OVS_NOT_REACHED(); | |
273 | } | |
274 | } | |
275 | \f | |
276 | /* Formatting. */ | |
277 | ||
278 | static void | |
279 | find_bitwise_range(const union mf_subvalue *sv, int width, | |
280 | int *startp, int *n_bitsp) | |
281 | { | |
282 | unsigned int start = bitwise_scan(sv, sizeof *sv, true, 0, width); | |
283 | if (start < width) { | |
284 | unsigned int end = bitwise_scan(sv, sizeof *sv, false, start, width); | |
285 | if (end >= width | |
286 | || bitwise_scan(sv, sizeof *sv, true, end, width) >= width) { | |
287 | *startp = start; | |
288 | *n_bitsp = end - start; | |
289 | return; | |
290 | } | |
291 | } | |
292 | *startp = *n_bitsp = 0; | |
293 | } | |
294 | ||
e0840f11 BP |
295 | static void |
296 | expr_format_cmp(const struct expr *e, struct ds *s) | |
297 | { | |
298 | /* The common case is numerical comparisons. | |
299 | * Handle string comparisons as a special case. */ | |
300 | if (!e->cmp.symbol->width) { | |
301 | ds_put_format(s, "%s %s ", e->cmp.symbol->name, | |
302 | expr_relop_to_string(e->cmp.relop)); | |
3b626771 | 303 | json_string_escape(e->cmp.string, s); |
e0840f11 BP |
304 | return; |
305 | } | |
306 | ||
307 | int ofs, n; | |
308 | find_bitwise_range(&e->cmp.mask, e->cmp.symbol->width, &ofs, &n); | |
309 | if (n == 1 && (e->cmp.relop == EXPR_R_EQ || e->cmp.relop == EXPR_R_NE)) { | |
310 | bool positive; | |
311 | ||
312 | positive = bitwise_get_bit(&e->cmp.value, sizeof e->cmp.value, ofs); | |
313 | positive ^= e->cmp.relop == EXPR_R_NE; | |
314 | if (!positive) { | |
315 | ds_put_char(s, '!'); | |
316 | } | |
317 | ds_put_cstr(s, e->cmp.symbol->name); | |
318 | if (e->cmp.symbol->width > 1) { | |
319 | ds_put_format(s, "[%d]", ofs); | |
320 | } | |
321 | return; | |
322 | } | |
323 | ||
324 | ds_put_cstr(s, e->cmp.symbol->name); | |
325 | if (n > 0 && n < e->cmp.symbol->width) { | |
326 | if (n > 1) { | |
327 | ds_put_format(s, "[%d..%d]", ofs, ofs + n - 1); | |
328 | } else { | |
329 | ds_put_format(s, "[%d]", ofs); | |
330 | } | |
331 | } | |
332 | ||
333 | ds_put_format(s, " %s ", expr_relop_to_string(e->cmp.relop)); | |
334 | ||
335 | if (n) { | |
336 | union mf_subvalue value; | |
337 | ||
338 | memset(&value, 0, sizeof value); | |
339 | bitwise_copy(&e->cmp.value, sizeof e->cmp.value, ofs, | |
340 | &value, sizeof value, 0, | |
341 | n); | |
342 | mf_format_subvalue(&value, s); | |
343 | } else { | |
344 | mf_format_subvalue(&e->cmp.value, s); | |
345 | ds_put_char(s, '/'); | |
346 | mf_format_subvalue(&e->cmp.mask, s); | |
347 | } | |
348 | } | |
349 | ||
350 | static void | |
351 | expr_format_andor(const struct expr *e, const char *op, struct ds *s) | |
352 | { | |
353 | struct expr *sub; | |
354 | int i = 0; | |
355 | ||
356 | LIST_FOR_EACH (sub, node, &e->andor) { | |
357 | if (i++) { | |
358 | ds_put_format(s, " %s ", op); | |
359 | } | |
360 | ||
361 | if (sub->type == EXPR_T_AND || sub->type == EXPR_T_OR) { | |
362 | ds_put_char(s, '('); | |
363 | expr_format(sub, s); | |
364 | ds_put_char(s, ')'); | |
365 | } else { | |
366 | expr_format(sub, s); | |
367 | } | |
368 | } | |
369 | } | |
370 | ||
371 | /* Appends a string form of 'e' to 's'. The string form is acceptable for | |
372 | * parsing back into an equivalent expression. */ | |
373 | void | |
374 | expr_format(const struct expr *e, struct ds *s) | |
375 | { | |
376 | switch (e->type) { | |
377 | case EXPR_T_CMP: | |
378 | expr_format_cmp(e, s); | |
379 | break; | |
380 | ||
381 | case EXPR_T_AND: | |
382 | expr_format_andor(e, "&&", s); | |
383 | break; | |
384 | ||
385 | case EXPR_T_OR: | |
386 | expr_format_andor(e, "||", s); | |
387 | break; | |
388 | ||
389 | case EXPR_T_BOOLEAN: | |
390 | ds_put_char(s, e->boolean ? '1' : '0'); | |
391 | break; | |
392 | } | |
393 | } | |
394 | ||
395 | /* Prints a string form of 'e' on stdout, followed by a new-line. */ | |
396 | void | |
397 | expr_print(const struct expr *e) | |
398 | { | |
399 | struct ds output; | |
400 | ||
401 | ds_init(&output); | |
402 | expr_format(e, &output); | |
403 | puts(ds_cstr(&output)); | |
404 | ds_destroy(&output); | |
405 | } | |
406 | \f | |
407 | /* Parsing. */ | |
408 | ||
e0840f11 BP |
409 | /* Context maintained during expr_parse(). */ |
410 | struct expr_context { | |
411 | struct lexer *lexer; /* Lexer for pulling more tokens. */ | |
412 | const struct shash *symtab; /* Symbol table. */ | |
2c5cbb15 | 413 | const struct shash *macros; /* Table of macros. */ |
e0840f11 BP |
414 | char *error; /* Error, if any, otherwise NULL. */ |
415 | bool not; /* True inside odd number of NOT operators. */ | |
416 | }; | |
417 | ||
418 | struct expr *expr_parse__(struct expr_context *); | |
419 | static void expr_not(struct expr *); | |
e0840f11 BP |
420 | static bool parse_field(struct expr_context *, struct expr_field *); |
421 | ||
422 | static bool | |
423 | expr_error_handle_common(struct expr_context *ctx) | |
424 | { | |
425 | if (ctx->error) { | |
426 | /* Already have an error, suppress this one since the cascade seems | |
427 | * unlikely to be useful. */ | |
428 | return true; | |
429 | } else if (ctx->lexer->token.type == LEX_T_ERROR) { | |
430 | /* The lexer signaled an error. Nothing at the expression level | |
431 | * accepts an error token, so we'll inevitably end up here with some | |
432 | * meaningless parse error. Report the lexical error instead. */ | |
433 | ctx->error = xstrdup(ctx->lexer->token.s); | |
434 | return true; | |
435 | } else { | |
436 | return false; | |
437 | } | |
438 | } | |
439 | ||
440 | static void OVS_PRINTF_FORMAT(2, 3) | |
441 | expr_error(struct expr_context *ctx, const char *message, ...) | |
442 | { | |
443 | if (expr_error_handle_common(ctx)) { | |
444 | return; | |
445 | } | |
446 | ||
447 | va_list args; | |
448 | va_start(args, message); | |
449 | ctx->error = xvasprintf(message, args); | |
450 | va_end(args); | |
451 | } | |
452 | ||
453 | static void OVS_PRINTF_FORMAT(2, 3) | |
454 | expr_syntax_error(struct expr_context *ctx, const char *message, ...) | |
455 | { | |
456 | if (expr_error_handle_common(ctx)) { | |
457 | return; | |
458 | } | |
459 | ||
460 | struct ds s; | |
461 | ||
462 | ds_init(&s); | |
463 | ds_put_cstr(&s, "Syntax error "); | |
464 | if (ctx->lexer->token.type == LEX_T_END) { | |
465 | ds_put_cstr(&s, "at end of input "); | |
466 | } else if (ctx->lexer->start) { | |
467 | ds_put_format(&s, "at `%.*s' ", | |
468 | (int) (ctx->lexer->input - ctx->lexer->start), | |
469 | ctx->lexer->start); | |
470 | } | |
471 | ||
472 | va_list args; | |
473 | va_start(args, message); | |
474 | ds_put_format_valist(&s, message, args); | |
475 | va_end(args); | |
476 | ||
477 | ctx->error = ds_steal_cstr(&s); | |
478 | } | |
479 | ||
480 | static struct expr * | |
481 | make_cmp__(const struct expr_field *f, enum expr_relop r, | |
482 | const union expr_constant *c) | |
483 | { | |
484 | struct expr *e = xzalloc(sizeof *e); | |
485 | e->type = EXPR_T_CMP; | |
486 | e->cmp.symbol = f->symbol; | |
487 | e->cmp.relop = r; | |
488 | if (f->symbol->width) { | |
489 | bitwise_copy(&c->value, sizeof c->value, 0, | |
490 | &e->cmp.value, sizeof e->cmp.value, f->ofs, | |
491 | f->n_bits); | |
492 | if (c->masked) { | |
493 | bitwise_copy(&c->mask, sizeof c->mask, 0, | |
494 | &e->cmp.mask, sizeof e->cmp.mask, f->ofs, | |
495 | f->n_bits); | |
496 | } else { | |
497 | bitwise_one(&e->cmp.mask, sizeof e->cmp.mask, f->ofs, | |
498 | f->n_bits); | |
499 | } | |
500 | } else { | |
501 | e->cmp.string = xstrdup(c->string); | |
502 | } | |
503 | return e; | |
504 | } | |
505 | ||
506 | /* Returns the minimum reasonable width for integer constant 'c'. */ | |
507 | static int | |
508 | expr_constant_width(const union expr_constant *c) | |
509 | { | |
510 | if (c->masked) { | |
511 | return mf_subvalue_width(&c->mask); | |
512 | } | |
513 | ||
514 | switch (c->format) { | |
515 | case LEX_F_DECIMAL: | |
516 | case LEX_F_HEXADECIMAL: | |
517 | return mf_subvalue_width(&c->value); | |
518 | ||
519 | case LEX_F_IPV4: | |
520 | return 32; | |
521 | ||
522 | case LEX_F_IPV6: | |
523 | return 128; | |
524 | ||
525 | case LEX_F_ETHERNET: | |
526 | return 48; | |
527 | ||
528 | default: | |
529 | OVS_NOT_REACHED(); | |
530 | } | |
531 | } | |
532 | ||
3b7cb7e1 BP |
533 | static bool |
534 | type_check(struct expr_context *ctx, const struct expr_field *f, | |
535 | struct expr_constant_set *cs) | |
536 | { | |
537 | if (cs->type != (f->symbol->width ? EXPR_C_INTEGER : EXPR_C_STRING)) { | |
538 | expr_error(ctx, "%s field %s is not compatible with %s constant.", | |
539 | f->symbol->width ? "Integer" : "String", | |
540 | f->symbol->name, | |
541 | cs->type == EXPR_C_INTEGER ? "integer" : "string"); | |
542 | return false; | |
543 | } | |
544 | ||
545 | if (f->symbol->width) { | |
546 | for (size_t i = 0; i < cs->n_values; i++) { | |
547 | int w = expr_constant_width(&cs->values[i]); | |
548 | if (w > f->symbol->width) { | |
549 | expr_error(ctx, "%d-bit constant is not compatible with " | |
550 | "%d-bit field %s.", | |
551 | w, f->symbol->width, f->symbol->name); | |
552 | return false; | |
553 | } | |
554 | } | |
555 | } | |
556 | ||
557 | return true; | |
558 | } | |
559 | ||
e0840f11 BP |
560 | static struct expr * |
561 | make_cmp(struct expr_context *ctx, | |
562 | const struct expr_field *f, enum expr_relop r, | |
563 | struct expr_constant_set *cs) | |
564 | { | |
565 | struct expr *e = NULL; | |
566 | ||
3b7cb7e1 | 567 | if (!type_check(ctx, f, cs)) { |
e0840f11 BP |
568 | goto exit; |
569 | } | |
570 | ||
571 | if (r != EXPR_R_EQ && r != EXPR_R_NE) { | |
572 | if (cs->in_curlies) { | |
573 | expr_error(ctx, "Only == and != operators may be used " | |
574 | "with value sets."); | |
575 | goto exit; | |
576 | } | |
577 | if (f->symbol->level == EXPR_L_NOMINAL || | |
578 | f->symbol->level == EXPR_L_BOOLEAN) { | |
579 | expr_error(ctx, "Only == and != operators may be used " | |
580 | "with %s field %s.", | |
581 | expr_level_to_string(f->symbol->level), | |
582 | f->symbol->name); | |
583 | goto exit; | |
584 | } | |
585 | if (cs->values[0].masked) { | |
586 | expr_error(ctx, "Only == and != operators may be used with " | |
587 | "masked constants. Consider using subfields instead " | |
588 | "(e.g. eth.src[0..15] > 0x1111 in place of " | |
589 | "eth.src > 00:00:00:00:11:11/00:00:00:00:ff:ff)."); | |
590 | goto exit; | |
591 | } | |
592 | } | |
593 | ||
594 | if (f->symbol->level == EXPR_L_NOMINAL) { | |
595 | if (f->symbol->expansion) { | |
fd477c6e | 596 | ovs_assert(f->symbol->width > 0); |
e0840f11 BP |
597 | for (size_t i = 0; i < cs->n_values; i++) { |
598 | const union mf_subvalue *value = &cs->values[i].value; | |
599 | bool positive = (value->integer & htonll(1)) != 0; | |
600 | positive ^= r == EXPR_R_NE; | |
601 | positive ^= ctx->not; | |
602 | if (!positive) { | |
603 | const char *name = f->symbol->name; | |
604 | expr_error(ctx, "Nominal predicate %s may only be tested " | |
605 | "positively, e.g. `%s' or `%s == 1' but not " | |
606 | "`!%s' or `%s == 0'.", | |
607 | name, name, name, name, name); | |
608 | goto exit; | |
609 | } | |
610 | } | |
611 | } else if (r != (ctx->not ? EXPR_R_NE : EXPR_R_EQ)) { | |
612 | expr_error(ctx, "Nominal field %s may only be tested for " | |
613 | "equality (taking enclosing `!' operators into " | |
614 | "account).", f->symbol->name); | |
615 | goto exit; | |
616 | } | |
617 | } | |
618 | ||
e0840f11 BP |
619 | e = make_cmp__(f, r, &cs->values[0]); |
620 | for (size_t i = 1; i < cs->n_values; i++) { | |
621 | e = expr_combine(r == EXPR_R_EQ ? EXPR_T_OR : EXPR_T_AND, | |
622 | e, make_cmp__(f, r, &cs->values[i])); | |
623 | } | |
624 | exit: | |
625 | expr_constant_set_destroy(cs); | |
626 | return e; | |
627 | } | |
628 | ||
629 | static bool | |
630 | expr_get_int(struct expr_context *ctx, int *value) | |
631 | { | |
558ec83d BP |
632 | bool ok = lexer_get_int(ctx->lexer, value); |
633 | if (!ok) { | |
e0840f11 | 634 | expr_syntax_error(ctx, "expecting small integer."); |
e0840f11 | 635 | } |
558ec83d | 636 | return ok; |
e0840f11 BP |
637 | } |
638 | ||
639 | static bool | |
640 | parse_field(struct expr_context *ctx, struct expr_field *f) | |
641 | { | |
642 | const struct expr_symbol *symbol; | |
643 | ||
644 | if (ctx->lexer->token.type != LEX_T_ID) { | |
645 | expr_syntax_error(ctx, "expecting field name."); | |
646 | return false; | |
647 | } | |
648 | ||
649 | symbol = shash_find_data(ctx->symtab, ctx->lexer->token.s); | |
650 | if (!symbol) { | |
651 | expr_syntax_error(ctx, "expecting field name."); | |
652 | return false; | |
653 | } | |
654 | lexer_get(ctx->lexer); | |
655 | ||
656 | f->symbol = symbol; | |
657 | if (lexer_match(ctx->lexer, LEX_T_LSQUARE)) { | |
658 | int low, high; | |
659 | ||
660 | if (!symbol->width) { | |
661 | expr_error(ctx, "Cannot select subfield of string field %s.", | |
662 | symbol->name); | |
663 | return false; | |
664 | } | |
665 | ||
666 | if (!expr_get_int(ctx, &low)) { | |
667 | return false; | |
668 | } | |
669 | if (lexer_match(ctx->lexer, LEX_T_ELLIPSIS)) { | |
670 | if (!expr_get_int(ctx, &high)) { | |
671 | return false; | |
672 | } | |
673 | } else { | |
674 | high = low; | |
675 | } | |
676 | ||
677 | if (!lexer_match(ctx->lexer, LEX_T_RSQUARE)) { | |
678 | expr_syntax_error(ctx, "expecting `]'."); | |
679 | return false; | |
680 | } | |
681 | ||
682 | if (low > high) { | |
683 | expr_error(ctx, "Invalid bit range %d to %d.", low, high); | |
684 | return false; | |
685 | } else if (high >= symbol->width) { | |
686 | expr_error(ctx, "Cannot select bits %d to %d of %d-bit field %s.", | |
687 | low, high, symbol->width, symbol->name); | |
688 | return false; | |
689 | } else if (symbol->level == EXPR_L_NOMINAL | |
690 | && (low != 0 || high != symbol->width - 1)) { | |
691 | expr_error(ctx, "Cannot select subfield of nominal field %s.", | |
692 | symbol->name); | |
693 | return false; | |
694 | } | |
695 | ||
696 | f->ofs = low; | |
697 | f->n_bits = high - low + 1; | |
698 | } else { | |
699 | f->ofs = 0; | |
700 | f->n_bits = symbol->width; | |
701 | } | |
702 | ||
703 | return true; | |
704 | } | |
705 | ||
706 | static bool | |
707 | parse_relop(struct expr_context *ctx, enum expr_relop *relop) | |
708 | { | |
709 | if (expr_relop_from_token(ctx->lexer->token.type, relop)) { | |
710 | lexer_get(ctx->lexer); | |
711 | return true; | |
712 | } else { | |
713 | expr_syntax_error(ctx, "expecting relational operator."); | |
714 | return false; | |
715 | } | |
716 | } | |
717 | ||
718 | static bool | |
719 | assign_constant_set_type(struct expr_context *ctx, | |
720 | struct expr_constant_set *cs, | |
721 | enum expr_constant_type type) | |
722 | { | |
723 | if (!cs->n_values || cs->type == type) { | |
724 | cs->type = type; | |
725 | return true; | |
726 | } else { | |
727 | expr_syntax_error(ctx, "expecting %s.", | |
728 | cs->type == EXPR_C_INTEGER ? "integer" : "string"); | |
729 | return false; | |
730 | } | |
731 | } | |
732 | ||
2c5cbb15 RB |
733 | static bool |
734 | parse_macros(struct expr_context *ctx, struct expr_constant_set *cs, | |
735 | size_t *allocated_values) | |
736 | { | |
737 | struct expr_constant_set *addr_set | |
ab5a5bd9 BP |
738 | = (ctx->macros |
739 | ? shash_find_data(ctx->macros, ctx->lexer->token.s) | |
740 | : NULL); | |
2c5cbb15 RB |
741 | if (!addr_set) { |
742 | expr_syntax_error(ctx, "expecting address set name."); | |
743 | return false; | |
744 | } | |
745 | ||
746 | if (!assign_constant_set_type(ctx, cs, EXPR_C_INTEGER)) { | |
747 | return false; | |
748 | } | |
749 | ||
750 | size_t n_values = cs->n_values + addr_set->n_values; | |
751 | if (n_values >= *allocated_values) { | |
752 | cs->values = xrealloc(cs->values, n_values * sizeof *cs->values); | |
753 | *allocated_values = n_values; | |
754 | } | |
755 | for (size_t i = 0; i < addr_set->n_values; i++) { | |
756 | cs->values[cs->n_values++] = addr_set->values[i]; | |
757 | } | |
758 | ||
759 | return true; | |
760 | } | |
761 | ||
e0840f11 BP |
762 | static bool |
763 | parse_constant(struct expr_context *ctx, struct expr_constant_set *cs, | |
764 | size_t *allocated_values) | |
765 | { | |
766 | if (cs->n_values >= *allocated_values) { | |
767 | cs->values = x2nrealloc(cs->values, allocated_values, | |
768 | sizeof *cs->values); | |
769 | } | |
770 | ||
771 | if (ctx->lexer->token.type == LEX_T_STRING) { | |
772 | if (!assign_constant_set_type(ctx, cs, EXPR_C_STRING)) { | |
773 | return false; | |
774 | } | |
775 | cs->values[cs->n_values++].string = xstrdup(ctx->lexer->token.s); | |
776 | lexer_get(ctx->lexer); | |
777 | return true; | |
778 | } else if (ctx->lexer->token.type == LEX_T_INTEGER || | |
779 | ctx->lexer->token.type == LEX_T_MASKED_INTEGER) { | |
780 | if (!assign_constant_set_type(ctx, cs, EXPR_C_INTEGER)) { | |
781 | return false; | |
782 | } | |
783 | ||
784 | union expr_constant *c = &cs->values[cs->n_values++]; | |
785 | c->value = ctx->lexer->token.value; | |
786 | c->format = ctx->lexer->token.format; | |
787 | c->masked = ctx->lexer->token.type == LEX_T_MASKED_INTEGER; | |
788 | if (c->masked) { | |
789 | c->mask = ctx->lexer->token.mask; | |
790 | } | |
791 | lexer_get(ctx->lexer); | |
792 | return true; | |
2c5cbb15 RB |
793 | } else if (ctx->lexer->token.type == LEX_T_MACRO) { |
794 | if (!parse_macros(ctx, cs, allocated_values)) { | |
795 | return false; | |
796 | } | |
797 | lexer_get(ctx->lexer); | |
798 | return true; | |
e0840f11 BP |
799 | } else { |
800 | expr_syntax_error(ctx, "expecting constant."); | |
801 | return false; | |
802 | } | |
803 | } | |
804 | ||
805 | /* Parses a single or {}-enclosed set of integer or string constants into 'cs', | |
806 | * which the caller need not have initialized. Returns true on success, in | |
807 | * which case the caller owns 'cs', false on failure, in which case 'cs' is | |
808 | * indeterminate. */ | |
809 | static bool | |
810 | parse_constant_set(struct expr_context *ctx, struct expr_constant_set *cs) | |
811 | { | |
812 | size_t allocated_values = 0; | |
813 | bool ok; | |
814 | ||
815 | memset(cs, 0, sizeof *cs); | |
816 | if (lexer_match(ctx->lexer, LEX_T_LCURLY)) { | |
817 | ok = true; | |
818 | cs->in_curlies = true; | |
819 | do { | |
820 | if (!parse_constant(ctx, cs, &allocated_values)) { | |
821 | ok = false; | |
822 | break; | |
823 | } | |
824 | lexer_match(ctx->lexer, LEX_T_COMMA); | |
825 | } while (!lexer_match(ctx->lexer, LEX_T_RCURLY)); | |
826 | } else { | |
827 | ok = parse_constant(ctx, cs, &allocated_values); | |
828 | } | |
829 | if (!ok) { | |
830 | expr_constant_set_destroy(cs); | |
831 | } | |
832 | return ok; | |
833 | } | |
834 | ||
42814145 | 835 | void |
e0840f11 BP |
836 | expr_constant_set_destroy(struct expr_constant_set *cs) |
837 | { | |
838 | if (cs) { | |
839 | if (cs->type == EXPR_C_STRING) { | |
840 | for (size_t i = 0; i < cs->n_values; i++) { | |
841 | free(cs->values[i].string); | |
842 | } | |
843 | } | |
844 | free(cs->values); | |
845 | } | |
846 | } | |
847 | ||
2c5cbb15 RB |
848 | /* Adds a macro named 'name' to 'macros', replacing any existing macro with the |
849 | * given name. */ | |
850 | void | |
851 | expr_macros_add(struct shash *macros, const char *name, | |
852 | const char *const *values, size_t n_values) | |
853 | { | |
854 | /* Replace any existing entry for this name. */ | |
855 | expr_macros_remove(macros, name); | |
856 | ||
857 | struct expr_constant_set *cs = xzalloc(sizeof *cs); | |
858 | cs->type = EXPR_C_INTEGER; | |
859 | cs->in_curlies = true; | |
860 | cs->n_values = 0; | |
861 | cs->values = xmalloc(n_values * sizeof *cs->values); | |
862 | for (size_t i = 0; i < n_values; i++) { | |
863 | /* Use the lexer to convert each macro into the proper | |
864 | * integer format. */ | |
865 | struct lexer lex; | |
866 | lexer_init(&lex, values[i]); | |
867 | lexer_get(&lex); | |
868 | if (lex.token.type != LEX_T_INTEGER | |
869 | && lex.token.type != LEX_T_MASKED_INTEGER) { | |
870 | VLOG_WARN("Invalid address set entry: '%s', token type: %d", | |
871 | values[i], lex.token.type); | |
872 | } else { | |
873 | union expr_constant *c = &cs->values[cs->n_values++]; | |
874 | c->value = lex.token.value; | |
875 | c->format = lex.token.format; | |
876 | c->masked = lex.token.type == LEX_T_MASKED_INTEGER; | |
877 | if (c->masked) { | |
878 | c->mask = lex.token.mask; | |
879 | } | |
880 | } | |
881 | lexer_destroy(&lex); | |
882 | } | |
883 | ||
884 | shash_add(macros, name, cs); | |
885 | } | |
886 | ||
887 | void | |
888 | expr_macros_remove(struct shash *macros, const char *name) | |
889 | { | |
890 | struct expr_constant_set *cs = shash_find_and_delete(macros, name); | |
891 | if (cs) { | |
892 | expr_constant_set_destroy(cs); | |
893 | free(cs); | |
894 | } | |
895 | } | |
896 | ||
897 | /* Destroy all contents of 'macros'. */ | |
898 | void | |
899 | expr_macros_destroy(struct shash *macros) | |
900 | { | |
901 | struct shash_node *node, *next; | |
902 | ||
903 | SHASH_FOR_EACH_SAFE (node, next, macros) { | |
904 | struct expr_constant_set *cs = node->data; | |
905 | ||
906 | shash_delete(macros, node); | |
907 | expr_constant_set_destroy(cs); | |
908 | } | |
909 | } | |
910 | ||
e0840f11 BP |
911 | static struct expr * |
912 | expr_parse_primary(struct expr_context *ctx, bool *atomic) | |
913 | { | |
914 | *atomic = false; | |
915 | if (lexer_match(ctx->lexer, LEX_T_LPAREN)) { | |
916 | struct expr *e = expr_parse__(ctx); | |
917 | if (!lexer_match(ctx->lexer, LEX_T_RPAREN)) { | |
918 | expr_destroy(e); | |
919 | expr_syntax_error(ctx, "expecting `)'."); | |
920 | return NULL; | |
921 | } | |
922 | *atomic = true; | |
923 | return e; | |
924 | } | |
925 | ||
926 | if (ctx->lexer->token.type == LEX_T_ID) { | |
927 | struct expr_field f; | |
928 | enum expr_relop r; | |
929 | struct expr_constant_set c; | |
930 | ||
931 | if (!parse_field(ctx, &f)) { | |
932 | return NULL; | |
933 | } | |
934 | ||
935 | if (!expr_relop_from_token(ctx->lexer->token.type, &r)) { | |
76da94b5 BP |
936 | if (!f.n_bits || ctx->lexer->token.type == LEX_T_EQUALS) { |
937 | expr_syntax_error(ctx, "expecting relational operator."); | |
938 | return NULL; | |
939 | } else if (f.n_bits > 1 && !ctx->not) { | |
e0840f11 | 940 | expr_error(ctx, "Explicit `!= 0' is required for inequality " |
76da94b5 | 941 | "test of multibit field against 0."); |
e0840f11 BP |
942 | return NULL; |
943 | } | |
944 | ||
945 | *atomic = true; | |
946 | ||
947 | union expr_constant *cst = xzalloc(sizeof *cst); | |
948 | cst->format = LEX_F_HEXADECIMAL; | |
949 | cst->masked = false; | |
950 | ||
951 | c.type = EXPR_C_INTEGER; | |
952 | c.values = cst; | |
953 | c.n_values = 1; | |
954 | c.in_curlies = false; | |
955 | return make_cmp(ctx, &f, EXPR_R_NE, &c); | |
956 | } else if (parse_relop(ctx, &r) && parse_constant_set(ctx, &c)) { | |
957 | return make_cmp(ctx, &f, r, &c); | |
958 | } else { | |
959 | return NULL; | |
960 | } | |
961 | } else { | |
962 | struct expr_constant_set c1; | |
963 | if (!parse_constant_set(ctx, &c1)) { | |
964 | return NULL; | |
965 | } | |
966 | ||
967 | if (!expr_relop_from_token(ctx->lexer->token.type, NULL) | |
968 | && c1.n_values == 1 | |
969 | && c1.type == EXPR_C_INTEGER | |
970 | && c1.values[0].format == LEX_F_DECIMAL | |
971 | && !c1.values[0].masked | |
972 | && !c1.in_curlies) { | |
973 | uint64_t x = ntohll(c1.values[0].value.integer); | |
974 | if (x <= 1) { | |
975 | *atomic = true; | |
976 | expr_constant_set_destroy(&c1); | |
977 | return expr_create_boolean(x); | |
978 | } | |
979 | } | |
980 | ||
981 | enum expr_relop r1; | |
982 | struct expr_field f; | |
983 | if (!parse_relop(ctx, &r1) || !parse_field(ctx, &f)) { | |
984 | expr_constant_set_destroy(&c1); | |
985 | return NULL; | |
986 | } | |
987 | ||
988 | if (!expr_relop_from_token(ctx->lexer->token.type, NULL)) { | |
989 | return make_cmp(ctx, &f, expr_relop_turn(r1), &c1); | |
990 | } | |
991 | ||
992 | enum expr_relop r2; | |
993 | struct expr_constant_set c2; | |
994 | if (!parse_relop(ctx, &r2) || !parse_constant_set(ctx, &c2)) { | |
995 | expr_constant_set_destroy(&c1); | |
996 | return NULL; | |
997 | } else { | |
998 | /* Reject "1 == field == 2", "1 < field > 2", and so on. */ | |
999 | if (!(((r1 == EXPR_R_LT || r1 == EXPR_R_LE) && | |
1000 | (r2 == EXPR_R_LT || r2 == EXPR_R_LE)) || | |
1001 | ((r1 == EXPR_R_GT || r1 == EXPR_R_GE) && | |
1002 | (r2 == EXPR_R_GT || r2 == EXPR_R_GE)))) { | |
1003 | expr_error(ctx, "Range expressions must have the form " | |
1004 | "`x < field < y' or `x > field > y', with each " | |
1005 | "`<' optionally replaced by `<=' or `>' by `>=')."); | |
1006 | expr_constant_set_destroy(&c1); | |
1007 | expr_constant_set_destroy(&c2); | |
1008 | return NULL; | |
1009 | } | |
1010 | ||
1011 | struct expr *e1 = make_cmp(ctx, &f, expr_relop_turn(r1), &c1); | |
1012 | struct expr *e2 = make_cmp(ctx, &f, r2, &c2); | |
1013 | if (ctx->error) { | |
1014 | expr_destroy(e1); | |
1015 | expr_destroy(e2); | |
1016 | return NULL; | |
1017 | } | |
1018 | return expr_combine(EXPR_T_AND, e1, e2); | |
1019 | } | |
1020 | } | |
1021 | } | |
1022 | ||
1023 | static struct expr * | |
1024 | expr_parse_not(struct expr_context *ctx) | |
1025 | { | |
1026 | bool atomic; | |
1027 | ||
1028 | if (lexer_match(ctx->lexer, LEX_T_LOG_NOT)) { | |
1029 | ctx->not = !ctx->not; | |
1030 | struct expr *expr = expr_parse_primary(ctx, &atomic); | |
1031 | ctx->not = !ctx->not; | |
1032 | ||
1033 | if (expr) { | |
1034 | if (!atomic) { | |
1035 | expr_error(ctx, "Missing parentheses around operand of !."); | |
1036 | expr_destroy(expr); | |
1037 | return NULL; | |
1038 | } | |
1039 | expr_not(expr); | |
1040 | } | |
1041 | return expr; | |
1042 | } else { | |
1043 | return expr_parse_primary(ctx, &atomic); | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | struct expr * | |
1048 | expr_parse__(struct expr_context *ctx) | |
1049 | { | |
1050 | struct expr *e = expr_parse_not(ctx); | |
1051 | if (!e) { | |
1052 | return NULL; | |
1053 | } | |
1054 | ||
1055 | enum lex_type lex_type = ctx->lexer->token.type; | |
1056 | if (lex_type == LEX_T_LOG_AND || lex_type == LEX_T_LOG_OR) { | |
1057 | enum expr_type expr_type | |
1058 | = lex_type == LEX_T_LOG_AND ? EXPR_T_AND : EXPR_T_OR; | |
1059 | ||
1060 | lexer_get(ctx->lexer); | |
1061 | do { | |
1062 | struct expr *e2 = expr_parse_not(ctx); | |
1063 | if (!e2) { | |
1064 | expr_destroy(e); | |
1065 | return NULL; | |
1066 | } | |
1067 | e = expr_combine(expr_type, e, e2); | |
1068 | } while (lexer_match(ctx->lexer, lex_type)); | |
1069 | if (ctx->lexer->token.type == LEX_T_LOG_AND | |
1070 | || ctx->lexer->token.type == LEX_T_LOG_OR) { | |
1071 | expr_destroy(e); | |
1072 | expr_error(ctx, | |
1073 | "&& and || must be parenthesized when used together."); | |
1074 | return NULL; | |
1075 | } | |
1076 | } | |
1077 | return e; | |
1078 | } | |
1079 | ||
1080 | /* Parses an expression using the symbols in 'symtab' from 'lexer'. If | |
1081 | * successful, returns the new expression and sets '*errorp' to NULL. On | |
1082 | * failure, returns NULL and sets '*errorp' to an explanatory error message. | |
1083 | * The caller must eventually free the returned expression (with | |
1084 | * expr_destroy()) or error (with free()). */ | |
1085 | struct expr * | |
2c5cbb15 RB |
1086 | expr_parse(struct lexer *lexer, const struct shash *symtab, |
1087 | const struct shash *macros, char **errorp) | |
e0840f11 | 1088 | { |
2c5cbb15 RB |
1089 | struct expr_context ctx = { .lexer = lexer, |
1090 | .symtab = symtab, | |
1091 | .macros = macros }; | |
e0840f11 BP |
1092 | struct expr *e = expr_parse__(&ctx); |
1093 | *errorp = ctx.error; | |
1094 | ovs_assert((ctx.error != NULL) != (e != NULL)); | |
1095 | return e; | |
1096 | } | |
1097 | ||
1098 | /* Like expr_parse(), but the expression is taken from 's'. */ | |
1099 | struct expr * | |
2c5cbb15 RB |
1100 | expr_parse_string(const char *s, const struct shash *symtab, |
1101 | const struct shash *macros, char **errorp) | |
e0840f11 BP |
1102 | { |
1103 | struct lexer lexer; | |
1104 | struct expr *expr; | |
1105 | ||
1106 | lexer_init(&lexer, s); | |
1107 | lexer_get(&lexer); | |
2c5cbb15 | 1108 | expr = expr_parse(&lexer, symtab, macros, errorp); |
8b34ccda | 1109 | if (!*errorp && lexer.token.type != LEX_T_END) { |
e0840f11 BP |
1110 | *errorp = xstrdup("Extra tokens at end of input."); |
1111 | expr_destroy(expr); | |
1112 | expr = NULL; | |
1113 | } | |
1114 | lexer_destroy(&lexer); | |
1115 | ||
1116 | return expr; | |
1117 | } | |
1118 | \f | |
1119 | static struct expr_symbol * | |
1120 | add_symbol(struct shash *symtab, const char *name, int width, | |
1121 | const char *prereqs, enum expr_level level, | |
1122 | bool must_crossproduct) | |
1123 | { | |
1124 | struct expr_symbol *symbol = xzalloc(sizeof *symbol); | |
1125 | symbol->name = xstrdup(name); | |
1126 | symbol->prereqs = prereqs && prereqs[0] ? xstrdup(prereqs) : NULL; | |
1127 | symbol->width = width; | |
1128 | symbol->level = level; | |
1129 | symbol->must_crossproduct = must_crossproduct; | |
1130 | shash_add_assert(symtab, symbol->name, symbol); | |
1131 | return symbol; | |
1132 | } | |
1133 | ||
1134 | /* Adds field 'id' to symbol table 'symtab' under the given 'name'. Whenever | |
1135 | * 'name' is referenced, expression annotation (see expr_annotate()) will | |
1136 | * ensure that 'prereqs' are also true. If 'must_crossproduct' is true, then | |
1137 | * conversion to flows will never attempt to use the field as a conjunctive | |
1138 | * match dimension (see "Crossproducting" in the large comment on struct | |
1139 | * expr_symbol in expr.h for an example). | |
1140 | * | |
1141 | * A given field 'id' must only be used for a single symbol in a symbol table. | |
1142 | * Use subfields to duplicate or subset a field (you can even make a subfield | |
1143 | * include all the bits of the "parent" field if you like). */ | |
1144 | struct expr_symbol * | |
1145 | expr_symtab_add_field(struct shash *symtab, const char *name, | |
1146 | enum mf_field_id id, const char *prereqs, | |
1147 | bool must_crossproduct) | |
1148 | { | |
1149 | const struct mf_field *field = mf_from_id(id); | |
1150 | struct expr_symbol *symbol; | |
1151 | ||
1152 | symbol = add_symbol(symtab, name, field->n_bits, prereqs, | |
1153 | (field->maskable == MFM_FULLY | |
1154 | ? EXPR_L_ORDINAL | |
1155 | : EXPR_L_NOMINAL), | |
1156 | must_crossproduct); | |
1157 | symbol->field = field; | |
1158 | return symbol; | |
1159 | } | |
1160 | ||
1161 | static bool | |
1162 | parse_field_from_string(const char *s, const struct shash *symtab, | |
1163 | struct expr_field *field, char **errorp) | |
1164 | { | |
1165 | struct lexer lexer; | |
1166 | lexer_init(&lexer, s); | |
1167 | lexer_get(&lexer); | |
1168 | ||
1998e474 | 1169 | struct expr_context ctx = { .lexer = &lexer, .symtab = symtab }; |
e0840f11 BP |
1170 | bool ok = parse_field(&ctx, field); |
1171 | if (!ok) { | |
1172 | *errorp = ctx.error; | |
1173 | } else if (lexer.token.type != LEX_T_END) { | |
1174 | *errorp = xstrdup("Extra tokens at end of input."); | |
1175 | ok = false; | |
1176 | } | |
1177 | ||
1178 | lexer_destroy(&lexer); | |
1179 | ||
1180 | return ok; | |
1181 | } | |
1182 | ||
1183 | /* Adds 'name' as a subfield of a larger field in 'symtab'. Whenever | |
1184 | * 'name' is referenced, expression annotation (see expr_annotate()) will | |
1185 | * ensure that 'prereqs' are also true. | |
1186 | * | |
1187 | * 'subfield' must describe the subfield as a string, e.g. "vlan.tci[0..11]" | |
1188 | * for the low 12 bits of a larger field named "vlan.tci". */ | |
1189 | struct expr_symbol * | |
1190 | expr_symtab_add_subfield(struct shash *symtab, const char *name, | |
1191 | const char *prereqs, const char *subfield) | |
1192 | { | |
1193 | struct expr_symbol *symbol; | |
1194 | struct expr_field f; | |
1195 | char *error; | |
1196 | ||
1197 | if (!parse_field_from_string(subfield, symtab, &f, &error)) { | |
1198 | VLOG_WARN("%s: error parsing %s subfield (%s)", subfield, name, error); | |
1199 | free(error); | |
1200 | return NULL; | |
1201 | } | |
1202 | ||
1203 | enum expr_level level = f.symbol->level; | |
1204 | if (level != EXPR_L_ORDINAL) { | |
1205 | VLOG_WARN("can't define %s as subfield of %s field %s", | |
1206 | name, expr_level_to_string(level), f.symbol->name); | |
1207 | } | |
1208 | ||
1209 | symbol = add_symbol(symtab, name, f.n_bits, prereqs, level, false); | |
1210 | symbol->expansion = xstrdup(subfield); | |
1211 | return symbol; | |
1212 | } | |
1213 | ||
1214 | /* Adds a string-valued symbol named 'name' to 'symtab' with the specified | |
1215 | * 'prereqs'. */ | |
1216 | struct expr_symbol * | |
1217 | expr_symtab_add_string(struct shash *symtab, const char *name, | |
f386a8a7 | 1218 | enum mf_field_id id, const char *prereqs) |
e0840f11 | 1219 | { |
f386a8a7 BP |
1220 | const struct mf_field *field = mf_from_id(id); |
1221 | struct expr_symbol *symbol; | |
1222 | ||
1223 | symbol = add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, false); | |
1224 | symbol->field = field; | |
1225 | return symbol; | |
e0840f11 BP |
1226 | } |
1227 | ||
1228 | static enum expr_level | |
1229 | expr_get_level(const struct expr *expr) | |
1230 | { | |
1231 | const struct expr *sub; | |
1232 | enum expr_level level = EXPR_L_ORDINAL; | |
1233 | ||
1234 | switch (expr->type) { | |
1235 | case EXPR_T_CMP: | |
1236 | return (expr->cmp.symbol->level == EXPR_L_NOMINAL | |
1237 | ? EXPR_L_NOMINAL | |
1238 | : EXPR_L_BOOLEAN); | |
1239 | ||
1240 | case EXPR_T_AND: | |
1241 | case EXPR_T_OR: | |
1242 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1243 | enum expr_level sub_level = expr_get_level(sub); | |
1244 | level = MIN(level, sub_level); | |
1245 | } | |
1246 | return level; | |
1247 | ||
1248 | case EXPR_T_BOOLEAN: | |
1249 | return EXPR_L_BOOLEAN; | |
1250 | ||
1251 | default: | |
1252 | OVS_NOT_REACHED(); | |
1253 | } | |
1254 | } | |
1255 | ||
1256 | static enum expr_level | |
1257 | expr_parse_level(const char *s, const struct shash *symtab, char **errorp) | |
1258 | { | |
2c5cbb15 | 1259 | struct expr *expr = expr_parse_string(s, symtab, NULL, errorp); |
e0840f11 BP |
1260 | enum expr_level level = expr ? expr_get_level(expr) : EXPR_L_NOMINAL; |
1261 | expr_destroy(expr); | |
1262 | return level; | |
1263 | } | |
1264 | ||
1265 | /* Adds a predicate symbol, whose value is the given Boolean 'expression', | |
44283953 | 1266 | * named 'name' to 'symtab'. For example, "ip4 && ip4.proto == 6" might be an |
e0840f11 BP |
1267 | * appropriate predicate named "tcp4". */ |
1268 | struct expr_symbol * | |
1269 | expr_symtab_add_predicate(struct shash *symtab, const char *name, | |
1270 | const char *expansion) | |
1271 | { | |
1272 | struct expr_symbol *symbol; | |
1273 | enum expr_level level; | |
1274 | char *error; | |
1275 | ||
1276 | level = expr_parse_level(expansion, symtab, &error); | |
1277 | if (error) { | |
1278 | VLOG_WARN("%s: error parsing %s expansion (%s)", | |
1279 | expansion, name, error); | |
1280 | free(error); | |
1281 | return NULL; | |
1282 | } | |
1283 | ||
1284 | symbol = add_symbol(symtab, name, 1, NULL, level, false); | |
1285 | symbol->expansion = xstrdup(expansion); | |
1286 | return symbol; | |
1287 | } | |
1288 | ||
1289 | /* Destroys 'symtab' and all of its symbols. */ | |
1290 | void | |
1291 | expr_symtab_destroy(struct shash *symtab) | |
1292 | { | |
1293 | struct shash_node *node, *next; | |
1294 | ||
1295 | SHASH_FOR_EACH_SAFE (node, next, symtab) { | |
1296 | struct expr_symbol *symbol = node->data; | |
1297 | ||
1298 | shash_delete(symtab, node); | |
1299 | free(symbol->name); | |
1300 | free(symbol->prereqs); | |
1301 | free(symbol->expansion); | |
1302 | free(symbol); | |
1303 | } | |
1304 | } | |
1305 | \f | |
1306 | /* Cloning. */ | |
1307 | ||
1308 | static struct expr * | |
1309 | expr_clone_cmp(struct expr *expr) | |
1310 | { | |
1311 | struct expr *new = xmemdup(expr, sizeof *expr); | |
1312 | if (!new->cmp.symbol->width) { | |
1313 | new->cmp.string = xstrdup(new->cmp.string); | |
1314 | } | |
1315 | return new; | |
1316 | } | |
1317 | ||
1318 | static struct expr * | |
1319 | expr_clone_andor(struct expr *expr) | |
1320 | { | |
1321 | struct expr *new = expr_create_andor(expr->type); | |
1322 | struct expr *sub; | |
1323 | ||
1324 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1325 | struct expr *new_sub = expr_clone(sub); | |
417e7e66 | 1326 | ovs_list_push_back(&new->andor, &new_sub->node); |
e0840f11 BP |
1327 | } |
1328 | return new; | |
1329 | } | |
1330 | ||
1331 | /* Returns a clone of 'expr'. This is a "deep copy": neither the returned | |
1332 | * expression nor any of its substructure will be shared with 'expr'. */ | |
1333 | struct expr * | |
1334 | expr_clone(struct expr *expr) | |
1335 | { | |
1336 | switch (expr->type) { | |
1337 | case EXPR_T_CMP: | |
1338 | return expr_clone_cmp(expr); | |
1339 | ||
1340 | case EXPR_T_AND: | |
1341 | case EXPR_T_OR: | |
1342 | return expr_clone_andor(expr); | |
1343 | ||
1344 | case EXPR_T_BOOLEAN: | |
1345 | return expr_create_boolean(expr->boolean); | |
1346 | } | |
1347 | OVS_NOT_REACHED(); | |
1348 | } | |
1349 | \f | |
1350 | /* Destroys 'expr' and all of the sub-expressions it references. */ | |
1351 | void | |
1352 | expr_destroy(struct expr *expr) | |
1353 | { | |
1354 | if (!expr) { | |
1355 | return; | |
1356 | } | |
1357 | ||
1358 | struct expr *sub, *next; | |
1359 | ||
1360 | switch (expr->type) { | |
1361 | case EXPR_T_CMP: | |
1362 | if (!expr->cmp.symbol->width) { | |
1363 | free(expr->cmp.string); | |
1364 | } | |
1365 | break; | |
1366 | ||
1367 | case EXPR_T_AND: | |
1368 | case EXPR_T_OR: | |
1369 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1370 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1371 | expr_destroy(sub); |
1372 | } | |
1373 | break; | |
1374 | ||
1375 | case EXPR_T_BOOLEAN: | |
1376 | break; | |
1377 | } | |
1378 | free(expr); | |
1379 | } | |
1380 | \f | |
1381 | /* Annotation. */ | |
1382 | ||
1383 | /* An element in a linked list of symbols. | |
1384 | * | |
1385 | * Used to detect when a symbol is being expanded recursively, to allow | |
1386 | * flagging an error. */ | |
1387 | struct annotation_nesting { | |
1388 | struct ovs_list node; | |
1389 | const struct expr_symbol *symbol; | |
1390 | }; | |
1391 | ||
1392 | struct expr *expr_annotate__(struct expr *, const struct shash *symtab, | |
1393 | struct ovs_list *nesting, char **errorp); | |
1394 | ||
1395 | static struct expr * | |
1396 | parse_and_annotate(const char *s, const struct shash *symtab, | |
1397 | struct ovs_list *nesting, char **errorp) | |
1398 | { | |
1399 | char *error; | |
1400 | struct expr *expr; | |
1401 | ||
2c5cbb15 | 1402 | expr = expr_parse_string(s, symtab, NULL, &error); |
e0840f11 BP |
1403 | if (expr) { |
1404 | expr = expr_annotate__(expr, symtab, nesting, &error); | |
1405 | } | |
3b7cb7e1 BP |
1406 | if (expr) { |
1407 | *errorp = NULL; | |
1408 | } else { | |
e0840f11 BP |
1409 | *errorp = xasprintf("Error parsing expression `%s' encountered as " |
1410 | "prerequisite or predicate of initial expression: " | |
1411 | "%s", s, error); | |
1412 | free(error); | |
1413 | } | |
1414 | return expr; | |
1415 | } | |
1416 | ||
1417 | static struct expr * | |
1418 | expr_annotate_cmp(struct expr *expr, const struct shash *symtab, | |
1419 | struct ovs_list *nesting, char **errorp) | |
1420 | { | |
1421 | const struct expr_symbol *symbol = expr->cmp.symbol; | |
1422 | const struct annotation_nesting *iter; | |
1423 | LIST_FOR_EACH (iter, node, nesting) { | |
1424 | if (iter->symbol == symbol) { | |
1425 | *errorp = xasprintf("Recursive expansion of symbol `%s'.", | |
1426 | symbol->name); | |
1427 | expr_destroy(expr); | |
1428 | return NULL; | |
1429 | } | |
1430 | } | |
1431 | ||
1432 | struct annotation_nesting an; | |
1433 | an.symbol = symbol; | |
417e7e66 | 1434 | ovs_list_push_back(nesting, &an.node); |
e0840f11 BP |
1435 | |
1436 | struct expr *prereqs = NULL; | |
1437 | if (symbol->prereqs) { | |
1438 | prereqs = parse_and_annotate(symbol->prereqs, symtab, nesting, errorp); | |
1439 | if (!prereqs) { | |
1440 | goto error; | |
1441 | } | |
1442 | } | |
1443 | ||
1444 | if (symbol->expansion) { | |
1445 | if (symbol->level == EXPR_L_ORDINAL) { | |
1446 | struct expr_field field; | |
1447 | ||
1448 | if (!parse_field_from_string(symbol->expansion, symtab, | |
1449 | &field, errorp)) { | |
1450 | goto error; | |
1451 | } | |
1452 | ||
1453 | expr->cmp.symbol = field.symbol; | |
1454 | mf_subvalue_shift(&expr->cmp.value, field.ofs); | |
1455 | mf_subvalue_shift(&expr->cmp.mask, field.ofs); | |
1456 | } else { | |
1457 | struct expr *expansion; | |
1458 | ||
1459 | expansion = parse_and_annotate(symbol->expansion, symtab, | |
1460 | nesting, errorp); | |
1461 | if (!expansion) { | |
1462 | goto error; | |
1463 | } | |
1464 | ||
1465 | bool positive = (expr->cmp.value.integer & htonll(1)) != 0; | |
1466 | positive ^= expr->cmp.relop == EXPR_R_NE; | |
1467 | if (!positive) { | |
1468 | expr_not(expansion); | |
1469 | } | |
1470 | ||
1471 | expr_destroy(expr); | |
1472 | expr = expansion; | |
1473 | } | |
1474 | } | |
1475 | ||
46baac6d | 1476 | *errorp = NULL; |
417e7e66 | 1477 | ovs_list_remove(&an.node); |
e0840f11 BP |
1478 | return prereqs ? expr_combine(EXPR_T_AND, expr, prereqs) : expr; |
1479 | ||
1480 | error: | |
1481 | expr_destroy(expr); | |
1482 | expr_destroy(prereqs); | |
417e7e66 | 1483 | ovs_list_remove(&an.node); |
e0840f11 BP |
1484 | return NULL; |
1485 | } | |
1486 | ||
1487 | struct expr * | |
1488 | expr_annotate__(struct expr *expr, const struct shash *symtab, | |
1489 | struct ovs_list *nesting, char **errorp) | |
1490 | { | |
1491 | switch (expr->type) { | |
1492 | case EXPR_T_CMP: | |
1493 | return expr_annotate_cmp(expr, symtab, nesting, errorp); | |
1494 | ||
1495 | case EXPR_T_AND: | |
1496 | case EXPR_T_OR: { | |
1497 | struct expr *sub, *next; | |
1498 | ||
1499 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1500 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1501 | struct expr *new_sub = expr_annotate__(sub, symtab, |
1502 | nesting, errorp); | |
1503 | if (!new_sub) { | |
1504 | expr_destroy(expr); | |
1505 | return NULL; | |
1506 | } | |
1507 | expr_insert_andor(expr, next, new_sub); | |
1508 | } | |
1509 | *errorp = NULL; | |
1510 | return expr; | |
1511 | } | |
1512 | ||
1513 | case EXPR_T_BOOLEAN: | |
1514 | *errorp = NULL; | |
1515 | return expr; | |
1516 | ||
1517 | default: | |
1518 | OVS_NOT_REACHED(); | |
1519 | } | |
1520 | } | |
1521 | ||
1522 | /* "Annotates" 'expr', which does the following: | |
1523 | * | |
1524 | * - Applies prerequisites, by locating each comparison operator whose | |
1525 | * field has a prerequisite and adding a logical AND against those | |
1526 | * prerequisites. | |
1527 | * | |
1528 | * - Expands references to subfield symbols, by replacing them by | |
1529 | * references to their underlying field symbols (suitably shifted). | |
1530 | * | |
1531 | * - Expands references to predicate symbols, by replacing them by the | |
1532 | * expressions that they expand to. | |
1533 | * | |
1385d7b7 JP |
1534 | * In each case, annotation occurs recursively as necessary. |
1535 | * | |
46baac6d BP |
1536 | * If successful, returns the annotated expression and sets '*errorp' to NULL. |
1537 | * On failure, returns NULL and sets '*errorp' to an explanatory error message, | |
1538 | * which the caller must free. In either case, the caller transfers ownership | |
1539 | * of 'expr' and receives ownership of the returned expression, if any. */ | |
e0840f11 BP |
1540 | struct expr * |
1541 | expr_annotate(struct expr *expr, const struct shash *symtab, char **errorp) | |
1542 | { | |
1543 | struct ovs_list nesting = OVS_LIST_INITIALIZER(&nesting); | |
1544 | return expr_annotate__(expr, symtab, &nesting, errorp); | |
1545 | } | |
1546 | \f | |
1547 | static struct expr * | |
1548 | expr_simplify_ne(struct expr *expr) | |
1549 | { | |
1550 | struct expr *new = NULL; | |
1551 | const union mf_subvalue *value = &expr->cmp.value; | |
1552 | const union mf_subvalue *mask = &expr->cmp.mask; | |
1553 | int w = expr->cmp.symbol->width; | |
1554 | int i; | |
1555 | ||
1556 | for (i = 0; (i = bitwise_scan(mask, sizeof *mask, true, i, w)) < w; i++) { | |
1557 | struct expr *e; | |
1558 | ||
1559 | e = xzalloc(sizeof *e); | |
1560 | e->type = EXPR_T_CMP; | |
1561 | e->cmp.symbol = expr->cmp.symbol; | |
1562 | e->cmp.relop = EXPR_R_EQ; | |
1563 | bitwise_put_bit(&e->cmp.value, sizeof e->cmp.value, i, | |
1564 | !bitwise_get_bit(value, sizeof *value, i)); | |
1565 | bitwise_put1(&e->cmp.mask, sizeof e->cmp.mask, i); | |
1566 | ||
1567 | new = expr_combine(EXPR_T_OR, new, e); | |
1568 | } | |
1569 | ovs_assert(new); | |
1570 | ||
1571 | expr_destroy(expr); | |
1572 | ||
1573 | return new; | |
1574 | } | |
1575 | ||
1576 | static struct expr * | |
1577 | expr_simplify_relational(struct expr *expr) | |
1578 | { | |
1579 | const union mf_subvalue *value = &expr->cmp.value; | |
1580 | int start, n_bits, end; | |
1581 | ||
1582 | find_bitwise_range(&expr->cmp.mask, expr->cmp.symbol->width, | |
1583 | &start, &n_bits); | |
1584 | ovs_assert(n_bits > 0); | |
1585 | end = start + n_bits; | |
1586 | ||
1587 | struct expr *new; | |
1588 | if (expr->cmp.relop == EXPR_R_LE || expr->cmp.relop == EXPR_R_GE) { | |
1589 | new = xmemdup(expr, sizeof *expr); | |
1590 | new->cmp.relop = EXPR_R_EQ; | |
1591 | } else { | |
1592 | new = NULL; | |
1593 | } | |
1594 | ||
1595 | bool b = expr->cmp.relop == EXPR_R_LT || expr->cmp.relop == EXPR_R_LE; | |
1596 | for (int z = bitwise_scan(value, sizeof *value, b, start, end); | |
1597 | z < end; | |
1598 | z = bitwise_scan(value, sizeof *value, b, z + 1, end)) { | |
1599 | struct expr *e; | |
1600 | ||
1601 | e = xmemdup(expr, sizeof *expr); | |
1602 | e->cmp.relop = EXPR_R_EQ; | |
1603 | bitwise_toggle_bit(&e->cmp.value, sizeof e->cmp.value, z); | |
1604 | bitwise_zero(&e->cmp.value, sizeof e->cmp.value, start, z - start); | |
1605 | bitwise_zero(&e->cmp.mask, sizeof e->cmp.mask, start, z - start); | |
1606 | new = expr_combine(EXPR_T_OR, new, e); | |
1607 | } | |
1608 | expr_destroy(expr); | |
1609 | return new ? new : expr_create_boolean(false); | |
1610 | } | |
1611 | ||
1612 | /* Takes ownership of 'expr' and returns an equivalent expression whose | |
1613 | * EXPR_T_CMP nodes use only tests for equality (EXPR_R_EQ). */ | |
1614 | struct expr * | |
1615 | expr_simplify(struct expr *expr) | |
1616 | { | |
1617 | struct expr *sub, *next; | |
1618 | ||
1619 | switch (expr->type) { | |
1620 | case EXPR_T_CMP: | |
1621 | return (expr->cmp.relop == EXPR_R_EQ || !expr->cmp.symbol->width ? expr | |
1622 | : expr->cmp.relop == EXPR_R_NE ? expr_simplify_ne(expr) | |
1623 | : expr_simplify_relational(expr)); | |
1624 | ||
1625 | case EXPR_T_AND: | |
1626 | case EXPR_T_OR: | |
1627 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1628 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1629 | expr_insert_andor(expr, next, expr_simplify(sub)); |
1630 | } | |
1631 | return expr_fix(expr); | |
1632 | ||
1633 | case EXPR_T_BOOLEAN: | |
1634 | return expr; | |
1635 | } | |
1636 | OVS_NOT_REACHED(); | |
1637 | } | |
1638 | \f | |
1639 | static const struct expr_symbol * | |
1640 | expr_is_cmp(const struct expr *expr) | |
1641 | { | |
1642 | switch (expr->type) { | |
1643 | case EXPR_T_CMP: | |
1644 | return expr->cmp.symbol; | |
1645 | ||
1646 | case EXPR_T_AND: | |
1647 | case EXPR_T_OR: { | |
1648 | const struct expr_symbol *prev = NULL; | |
1649 | struct expr *sub; | |
1650 | ||
1651 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1652 | const struct expr_symbol *symbol = expr_is_cmp(sub); | |
1653 | if (!symbol || (prev && symbol != prev)) { | |
1654 | return NULL; | |
1655 | } | |
1656 | prev = symbol; | |
1657 | } | |
1658 | return prev; | |
1659 | } | |
1660 | ||
1661 | case EXPR_T_BOOLEAN: | |
1662 | return NULL; | |
1663 | ||
1664 | default: | |
1665 | OVS_NOT_REACHED(); | |
1666 | } | |
1667 | } | |
1668 | ||
1669 | struct expr_sort { | |
1670 | struct expr *expr; | |
1671 | const struct expr_symbol *relop; | |
1672 | enum expr_type type; | |
1673 | }; | |
1674 | ||
1675 | static int | |
1676 | compare_expr_sort(const void *a_, const void *b_) | |
1677 | { | |
1678 | const struct expr_sort *a = a_; | |
1679 | const struct expr_sort *b = b_; | |
1680 | ||
1681 | if (a->type != b->type) { | |
1682 | return a->type < b->type ? -1 : 1; | |
1683 | } else if (a->relop) { | |
1684 | int cmp = strcmp(a->relop->name, b->relop->name); | |
1685 | if (cmp) { | |
1686 | return cmp; | |
1687 | } | |
1688 | ||
1689 | enum expr_type a_type = a->expr->type; | |
1690 | enum expr_type b_type = a->expr->type; | |
1691 | return a_type < b_type ? -1 : a_type > b_type; | |
1692 | } else if (a->type == EXPR_T_AND || a->type == EXPR_T_OR) { | |
417e7e66 BW |
1693 | size_t a_len = ovs_list_size(&a->expr->andor); |
1694 | size_t b_len = ovs_list_size(&b->expr->andor); | |
e0840f11 BP |
1695 | return a_len < b_len ? -1 : a_len > b_len; |
1696 | } else { | |
1697 | return 0; | |
1698 | } | |
1699 | } | |
1700 | ||
1701 | static struct expr *crush_cmps(struct expr *, const struct expr_symbol *); | |
1702 | ||
9d4aecca BP |
1703 | static bool |
1704 | disjunction_matches_string(const struct expr *or, const char *s) | |
1705 | { | |
1706 | const struct expr *sub; | |
1707 | ||
1708 | LIST_FOR_EACH (sub, node, &or->andor) { | |
1709 | if (!strcmp(sub->cmp.string, s)) { | |
1710 | return true; | |
1711 | } | |
1712 | } | |
1713 | ||
1714 | return false; | |
1715 | } | |
1716 | ||
1717 | /* Implementation of crush_cmps() for expr->type == EXPR_T_AND and a | |
1718 | * string-typed 'symbol'. */ | |
e0840f11 | 1719 | static struct expr * |
9d4aecca BP |
1720 | crush_and_string(struct expr *expr, const struct expr_symbol *symbol) |
1721 | { | |
417e7e66 | 1722 | ovs_assert(!ovs_list_is_short(&expr->andor)); |
9d4aecca BP |
1723 | |
1724 | struct expr *singleton = NULL; | |
1725 | ||
1726 | /* First crush each subexpression into either a single EXPR_T_CMP or an | |
1727 | * EXPR_T_OR with EXPR_T_CMP subexpressions. */ | |
1728 | struct expr *sub, *next = NULL; | |
1729 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1730 | ovs_list_remove(&sub->node); |
9d4aecca BP |
1731 | struct expr *new = crush_cmps(sub, symbol); |
1732 | switch (new->type) { | |
1733 | case EXPR_T_CMP: | |
1734 | if (!singleton) { | |
417e7e66 | 1735 | ovs_list_insert(&next->node, &new->node); |
9d4aecca BP |
1736 | singleton = new; |
1737 | } else { | |
1738 | bool match = !strcmp(new->cmp.string, singleton->cmp.string); | |
1739 | expr_destroy(new); | |
1740 | if (!match) { | |
1741 | expr_destroy(expr); | |
1742 | return expr_create_boolean(false); | |
1743 | } | |
1744 | } | |
1745 | break; | |
1746 | case EXPR_T_AND: | |
1747 | OVS_NOT_REACHED(); | |
1748 | case EXPR_T_OR: | |
417e7e66 | 1749 | ovs_list_insert(&next->node, &new->node); |
9d4aecca BP |
1750 | break; |
1751 | case EXPR_T_BOOLEAN: | |
1752 | if (!new->boolean) { | |
1753 | expr_destroy(expr); | |
1754 | return new; | |
1755 | } | |
1756 | free(new); | |
1757 | break; | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | /* If we have a singleton, then the result is either the singleton itself | |
1762 | * (if the ORs allow the singleton) or false. */ | |
1763 | if (singleton) { | |
1764 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1765 | if (sub->type == EXPR_T_OR | |
1766 | && !disjunction_matches_string(sub, singleton->cmp.string)) { | |
1767 | expr_destroy(expr); | |
1768 | return expr_create_boolean(false); | |
1769 | } | |
1770 | } | |
417e7e66 | 1771 | ovs_list_remove(&singleton->node); |
9d4aecca BP |
1772 | expr_destroy(expr); |
1773 | return singleton; | |
1774 | } | |
1775 | ||
1776 | /* Otherwise the result is the intersection of all of the ORs. */ | |
1777 | struct sset result = SSET_INITIALIZER(&result); | |
1778 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
1779 | struct sset strings = SSET_INITIALIZER(&strings); | |
1780 | const struct expr *s; | |
1781 | LIST_FOR_EACH (s, node, &sub->andor) { | |
1782 | sset_add(&strings, s->cmp.string); | |
1783 | } | |
1784 | if (sset_is_empty(&result)) { | |
1785 | sset_swap(&result, &strings); | |
1786 | } else { | |
1787 | sset_intersect(&result, &strings); | |
1788 | } | |
1789 | sset_destroy(&strings); | |
1790 | ||
1791 | if (sset_is_empty(&result)) { | |
1792 | expr_destroy(expr); | |
1793 | sset_destroy(&result); | |
1794 | return expr_create_boolean(false); | |
1795 | } | |
1796 | } | |
1797 | ||
1798 | expr_destroy(expr); | |
1799 | expr = expr_create_andor(EXPR_T_OR); | |
1800 | ||
1801 | const char *string; | |
1802 | SSET_FOR_EACH (string, &result) { | |
1803 | sub = xmalloc(sizeof *sub); | |
1804 | sub->type = EXPR_T_CMP; | |
1805 | sub->cmp.symbol = symbol; | |
1806 | sub->cmp.string = xstrdup(string); | |
417e7e66 | 1807 | ovs_list_push_back(&expr->andor, &sub->node); |
9d4aecca | 1808 | } |
1cad4a75 | 1809 | sset_destroy(&result); |
9d4aecca BP |
1810 | return expr_fix(expr); |
1811 | } | |
1812 | ||
1813 | /* Implementation of crush_cmps() for expr->type == EXPR_T_AND and a | |
1814 | * numeric-typed 'symbol'. */ | |
1815 | static struct expr * | |
1816 | crush_and_numeric(struct expr *expr, const struct expr_symbol *symbol) | |
e0840f11 | 1817 | { |
417e7e66 | 1818 | ovs_assert(!ovs_list_is_short(&expr->andor)); |
e0840f11 BP |
1819 | |
1820 | union mf_subvalue value, mask; | |
1821 | memset(&value, 0, sizeof value); | |
1822 | memset(&mask, 0, sizeof mask); | |
1823 | ||
1824 | struct expr *sub, *next = NULL; | |
1825 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1826 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1827 | struct expr *new = crush_cmps(sub, symbol); |
1828 | switch (new->type) { | |
1829 | case EXPR_T_CMP: | |
1830 | if (!mf_subvalue_intersect(&value, &mask, | |
1831 | &new->cmp.value, &new->cmp.mask, | |
1832 | &value, &mask)) { | |
1833 | expr_destroy(new); | |
1834 | expr_destroy(expr); | |
1835 | return expr_create_boolean(false); | |
1836 | } | |
1837 | expr_destroy(new); | |
1838 | break; | |
1839 | case EXPR_T_AND: | |
1840 | OVS_NOT_REACHED(); | |
1841 | case EXPR_T_OR: | |
417e7e66 | 1842 | ovs_list_insert(&next->node, &new->node); |
e0840f11 BP |
1843 | break; |
1844 | case EXPR_T_BOOLEAN: | |
1845 | if (!new->boolean) { | |
1846 | expr_destroy(expr); | |
1847 | return new; | |
1848 | } | |
45c4387b | 1849 | expr_destroy(new); |
e0840f11 BP |
1850 | break; |
1851 | } | |
1852 | } | |
417e7e66 | 1853 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
1854 | if (is_all_zeros(&mask, sizeof mask)) { |
1855 | expr_destroy(expr); | |
1856 | return expr_create_boolean(true); | |
1857 | } else { | |
1858 | struct expr *cmp; | |
1859 | cmp = xmalloc(sizeof *cmp); | |
1860 | cmp->type = EXPR_T_CMP; | |
1861 | cmp->cmp.symbol = symbol; | |
1862 | cmp->cmp.relop = EXPR_R_EQ; | |
1863 | cmp->cmp.value = value; | |
1864 | cmp->cmp.mask = mask; | |
1865 | expr_destroy(expr); | |
1866 | return cmp; | |
1867 | } | |
417e7e66 | 1868 | } else if (ovs_list_is_short(&expr->andor)) { |
e0840f11 BP |
1869 | /* Transform "a && (b || c || d)" into "ab || ac || ad" where "ab" is |
1870 | * computed as "a && b", etc. */ | |
417e7e66 | 1871 | struct expr *disjuncts = expr_from_node(ovs_list_pop_front(&expr->andor)); |
e0840f11 BP |
1872 | struct expr *or; |
1873 | ||
1874 | or = xmalloc(sizeof *or); | |
1875 | or->type = EXPR_T_OR; | |
417e7e66 | 1876 | ovs_list_init(&or->andor); |
e0840f11 BP |
1877 | |
1878 | ovs_assert(disjuncts->type == EXPR_T_OR); | |
1879 | LIST_FOR_EACH_SAFE (sub, next, node, &disjuncts->andor) { | |
1880 | ovs_assert(sub->type == EXPR_T_CMP); | |
417e7e66 | 1881 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1882 | if (mf_subvalue_intersect(&value, &mask, |
1883 | &sub->cmp.value, &sub->cmp.mask, | |
1884 | &sub->cmp.value, &sub->cmp.mask)) { | |
417e7e66 | 1885 | ovs_list_push_back(&or->andor, &sub->node); |
e0840f11 | 1886 | } else { |
45c4387b | 1887 | expr_destroy(sub); |
e0840f11 BP |
1888 | } |
1889 | } | |
1890 | free(disjuncts); | |
1891 | free(expr); | |
417e7e66 | 1892 | if (ovs_list_is_empty(&or->andor)) { |
e0840f11 BP |
1893 | free(or); |
1894 | return expr_create_boolean(false); | |
417e7e66 BW |
1895 | } else if (ovs_list_is_short(&or->andor)) { |
1896 | struct expr *cmp = expr_from_node(ovs_list_pop_front(&or->andor)); | |
e0840f11 BP |
1897 | free(or); |
1898 | return cmp; | |
1899 | } else { | |
1900 | return or; | |
1901 | } | |
1902 | } else { | |
1903 | /* Transform "x && (a0 || a1) && (b0 || b1) && ..." into | |
1904 | * "(xa0b0 || xa0b1 || xa1b0 || xa1b1) && ...". */ | |
417e7e66 BW |
1905 | struct expr *as = expr_from_node(ovs_list_pop_front(&expr->andor)); |
1906 | struct expr *bs = expr_from_node(ovs_list_pop_front(&expr->andor)); | |
e0840f11 BP |
1907 | struct expr *new = NULL; |
1908 | struct expr *or; | |
1909 | ||
1910 | or = xmalloc(sizeof *or); | |
1911 | or->type = EXPR_T_OR; | |
417e7e66 | 1912 | ovs_list_init(&or->andor); |
e0840f11 BP |
1913 | |
1914 | struct expr *a; | |
1915 | LIST_FOR_EACH (a, node, &as->andor) { | |
1916 | union mf_subvalue a_value, a_mask; | |
1917 | ||
1918 | ovs_assert(a->type == EXPR_T_CMP); | |
1919 | if (!mf_subvalue_intersect(&value, &mask, | |
1920 | &a->cmp.value, &a->cmp.mask, | |
1921 | &a_value, &a_mask)) { | |
1922 | continue; | |
1923 | } | |
1924 | ||
1925 | struct expr *b; | |
1926 | LIST_FOR_EACH (b, node, &bs->andor) { | |
1927 | ovs_assert(b->type == EXPR_T_CMP); | |
1928 | if (!new) { | |
1929 | new = xmalloc(sizeof *new); | |
1930 | new->type = EXPR_T_CMP; | |
1931 | new->cmp.symbol = symbol; | |
1932 | new->cmp.relop = EXPR_R_EQ; | |
1933 | } | |
1934 | if (mf_subvalue_intersect(&a_value, &a_mask, | |
1935 | &b->cmp.value, &b->cmp.mask, | |
1936 | &new->cmp.value, &new->cmp.mask)) { | |
417e7e66 | 1937 | ovs_list_push_back(&or->andor, &new->node); |
e0840f11 BP |
1938 | new = NULL; |
1939 | } | |
1940 | } | |
1941 | } | |
1942 | expr_destroy(as); | |
1943 | expr_destroy(bs); | |
1944 | free(new); | |
1945 | ||
417e7e66 | 1946 | if (ovs_list_is_empty(&or->andor)) { |
e0840f11 BP |
1947 | expr_destroy(expr); |
1948 | free(or); | |
1949 | return expr_create_boolean(false); | |
417e7e66 BW |
1950 | } else if (ovs_list_is_short(&or->andor)) { |
1951 | struct expr *cmp = expr_from_node(ovs_list_pop_front(&or->andor)); | |
e0840f11 | 1952 | free(or); |
417e7e66 | 1953 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
1954 | expr_destroy(expr); |
1955 | return crush_cmps(cmp, symbol); | |
1956 | } else { | |
1957 | return crush_cmps(expr_combine(EXPR_T_AND, cmp, expr), symbol); | |
1958 | } | |
417e7e66 | 1959 | } else if (!ovs_list_is_empty(&expr->andor)) { |
e0840f11 | 1960 | struct expr *e = expr_combine(EXPR_T_AND, or, expr); |
417e7e66 | 1961 | ovs_assert(!ovs_list_is_short(&e->andor)); |
e0840f11 BP |
1962 | return crush_cmps(e, symbol); |
1963 | } else { | |
1964 | expr_destroy(expr); | |
1965 | return crush_cmps(or, symbol); | |
1966 | } | |
1967 | } | |
1968 | } | |
1969 | ||
1970 | static int | |
9d4aecca BP |
1971 | compare_cmps_3way(const struct expr *a, const struct expr *b) |
1972 | { | |
1973 | ovs_assert(a->cmp.symbol == b->cmp.symbol); | |
1974 | if (!a->cmp.symbol->width) { | |
1975 | return strcmp(a->cmp.string, b->cmp.string); | |
1976 | } else { | |
1977 | int d = memcmp(&a->cmp.value, &b->cmp.value, sizeof a->cmp.value); | |
1978 | if (!d) { | |
1979 | d = memcmp(&a->cmp.mask, &b->cmp.mask, sizeof a->cmp.mask); | |
1980 | } | |
1981 | return d; | |
1982 | } | |
1983 | } | |
1984 | ||
1985 | static int | |
1986 | compare_cmps_cb(const void *a_, const void *b_) | |
e0840f11 BP |
1987 | { |
1988 | const struct expr *const *ap = a_; | |
1989 | const struct expr *const *bp = b_; | |
1990 | const struct expr *a = *ap; | |
1991 | const struct expr *b = *bp; | |
9d4aecca | 1992 | return compare_cmps_3way(a, b); |
e0840f11 BP |
1993 | } |
1994 | ||
fd477c6e | 1995 | /* Implementation of crush_cmps() for expr->type == EXPR_T_OR. */ |
e0840f11 BP |
1996 | static struct expr * |
1997 | crush_or(struct expr *expr, const struct expr_symbol *symbol) | |
1998 | { | |
1999 | struct expr *sub, *next = NULL; | |
2000 | ||
2001 | /* First, crush all the subexpressions. That might eliminate the | |
fd477c6e BP |
2002 | * OR-expression entirely; if so, return the result. Otherwise, 'expr' |
2003 | * is now a disjunction of cmps over the same symbol. */ | |
e0840f11 | 2004 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { |
417e7e66 | 2005 | ovs_list_remove(&sub->node); |
e0840f11 BP |
2006 | expr_insert_andor(expr, next, crush_cmps(sub, symbol)); |
2007 | } | |
2008 | expr = expr_fix(expr); | |
2009 | if (expr->type != EXPR_T_OR) { | |
2010 | return expr; | |
2011 | } | |
2012 | ||
fd477c6e | 2013 | /* Sort subexpressions by value and mask, to bring together duplicates. */ |
417e7e66 | 2014 | size_t n = ovs_list_size(&expr->andor); |
e0840f11 BP |
2015 | struct expr **subs = xmalloc(n * sizeof *subs); |
2016 | ||
2017 | size_t i = 0; | |
2018 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2019 | subs[i++] = sub; | |
2020 | } | |
2021 | ovs_assert(i == n); | |
2022 | ||
9d4aecca | 2023 | qsort(subs, n, sizeof *subs, compare_cmps_cb); |
e0840f11 | 2024 | |
9d4aecca | 2025 | /* Eliminate duplicates. */ |
417e7e66 BW |
2026 | ovs_list_init(&expr->andor); |
2027 | ovs_list_push_back(&expr->andor, &subs[0]->node); | |
e0840f11 | 2028 | for (i = 1; i < n; i++) { |
417e7e66 | 2029 | struct expr *a = expr_from_node(ovs_list_back(&expr->andor)); |
e0840f11 | 2030 | struct expr *b = subs[i]; |
9d4aecca | 2031 | if (compare_cmps_3way(a, b)) { |
417e7e66 | 2032 | ovs_list_push_back(&expr->andor, &b->node); |
e0840f11 | 2033 | } else { |
45c4387b | 2034 | expr_destroy(b); |
e0840f11 BP |
2035 | } |
2036 | } | |
2037 | free(subs); | |
2038 | return expr_fix(expr); | |
2039 | } | |
2040 | ||
fd477c6e BP |
2041 | /* Takes ownership of 'expr', which must be a cmp in the sense determined by |
2042 | * 'expr_is_cmp(expr)', where 'symbol' is the symbol returned by that function. | |
2043 | * Returns an equivalent expression owned by the caller that is a single | |
2044 | * EXPR_T_CMP or a disjunction of them or a EXPR_T_BOOLEAN. */ | |
e0840f11 BP |
2045 | static struct expr * |
2046 | crush_cmps(struct expr *expr, const struct expr_symbol *symbol) | |
2047 | { | |
2048 | switch (expr->type) { | |
2049 | case EXPR_T_OR: | |
2050 | return crush_or(expr, symbol); | |
2051 | ||
2052 | case EXPR_T_AND: | |
9d4aecca BP |
2053 | return (symbol->width |
2054 | ? crush_and_numeric(expr, symbol) | |
2055 | : crush_and_string(expr, symbol)); | |
e0840f11 BP |
2056 | |
2057 | case EXPR_T_CMP: | |
2058 | return expr; | |
2059 | ||
2060 | case EXPR_T_BOOLEAN: | |
2061 | return expr; | |
2062 | ||
2063 | default: | |
2064 | OVS_NOT_REACHED(); | |
2065 | } | |
2066 | } | |
2067 | ||
2068 | static struct expr * | |
2069 | expr_sort(struct expr *expr) | |
2070 | { | |
417e7e66 | 2071 | size_t n = ovs_list_size(&expr->andor); |
e0840f11 BP |
2072 | struct expr_sort *subs = xmalloc(n * sizeof *subs); |
2073 | struct expr *sub; | |
2074 | size_t i; | |
2075 | ||
2076 | i = 0; | |
2077 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2078 | subs[i].expr = sub; | |
2079 | subs[i].relop = expr_is_cmp(sub); | |
2080 | subs[i].type = subs[i].relop ? EXPR_T_CMP : sub->type; | |
2081 | i++; | |
2082 | } | |
2083 | ovs_assert(i == n); | |
2084 | ||
2085 | qsort(subs, n, sizeof *subs, compare_expr_sort); | |
2086 | ||
417e7e66 | 2087 | ovs_list_init(&expr->andor); |
e0840f11 BP |
2088 | for (int i = 0; i < n; ) { |
2089 | if (subs[i].relop) { | |
2090 | int j; | |
2091 | for (j = i + 1; j < n; j++) { | |
2092 | if (subs[i].relop != subs[j].relop) { | |
2093 | break; | |
2094 | } | |
2095 | } | |
2096 | ||
2097 | struct expr *crushed; | |
2098 | if (j == i + 1) { | |
2099 | crushed = crush_cmps(subs[i].expr, subs[i].relop); | |
2100 | } else { | |
2101 | struct expr *combined = subs[i].expr; | |
2102 | for (int k = i + 1; k < j; k++) { | |
2103 | combined = expr_combine(EXPR_T_AND, combined, | |
2104 | subs[k].expr); | |
2105 | } | |
417e7e66 | 2106 | ovs_assert(!ovs_list_is_short(&combined->andor)); |
e0840f11 BP |
2107 | crushed = crush_cmps(combined, subs[i].relop); |
2108 | } | |
2109 | if (crushed->type == EXPR_T_BOOLEAN) { | |
2110 | if (!crushed->boolean) { | |
2111 | for (int k = j; k < n; k++) { | |
2112 | expr_destroy(subs[k].expr); | |
2113 | } | |
2114 | expr_destroy(expr); | |
2115 | expr = crushed; | |
2116 | break; | |
2117 | } else { | |
2118 | free(crushed); | |
2119 | } | |
2120 | } else { | |
2121 | expr = expr_combine(EXPR_T_AND, expr, crushed); | |
2122 | } | |
2123 | i = j; | |
2124 | } else { | |
2125 | expr = expr_combine(EXPR_T_AND, expr, subs[i++].expr); | |
2126 | } | |
2127 | } | |
2128 | free(subs); | |
2129 | ||
2130 | return expr; | |
2131 | } | |
2132 | ||
2133 | static struct expr *expr_normalize_or(struct expr *expr); | |
2134 | ||
2135 | /* Returns 'expr', which is an AND, reduced to OR(AND(clause)) where | |
2136 | * a clause is a cmp or a disjunction of cmps on a single field. */ | |
2137 | static struct expr * | |
2138 | expr_normalize_and(struct expr *expr) | |
2139 | { | |
2140 | ovs_assert(expr->type == EXPR_T_AND); | |
2141 | ||
2142 | expr = expr_sort(expr); | |
2143 | if (expr->type != EXPR_T_AND) { | |
2144 | ovs_assert(expr->type == EXPR_T_BOOLEAN); | |
2145 | return expr; | |
2146 | } | |
2147 | ||
2148 | struct expr *a, *b; | |
2149 | LIST_FOR_EACH_SAFE (a, b, node, &expr->andor) { | |
2150 | if (&b->node == &expr->andor | |
9d4aecca BP |
2151 | || a->type != EXPR_T_CMP || b->type != EXPR_T_CMP |
2152 | || a->cmp.symbol != b->cmp.symbol) { | |
e0840f11 | 2153 | continue; |
9d4aecca BP |
2154 | } else if (a->cmp.symbol->width |
2155 | ? mf_subvalue_intersect(&a->cmp.value, &a->cmp.mask, | |
2156 | &b->cmp.value, &b->cmp.mask, | |
2157 | &b->cmp.value, &b->cmp.mask) | |
2158 | : !strcmp(a->cmp.string, b->cmp.string)) { | |
417e7e66 | 2159 | ovs_list_remove(&a->node); |
e0840f11 BP |
2160 | expr_destroy(a); |
2161 | } else { | |
2162 | expr_destroy(expr); | |
2163 | return expr_create_boolean(false); | |
2164 | } | |
2165 | } | |
417e7e66 BW |
2166 | if (ovs_list_is_short(&expr->andor)) { |
2167 | struct expr *sub = expr_from_node(ovs_list_front(&expr->andor)); | |
e0840f11 BP |
2168 | free(expr); |
2169 | return sub; | |
2170 | } | |
2171 | ||
2172 | struct expr *sub; | |
2173 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2174 | if (sub->type == EXPR_T_CMP) { | |
2175 | continue; | |
2176 | } | |
2177 | ||
2178 | ovs_assert(sub->type == EXPR_T_OR); | |
2179 | const struct expr_symbol *symbol = expr_is_cmp(sub); | |
2180 | if (!symbol || symbol->must_crossproduct) { | |
2181 | struct expr *or = expr_create_andor(EXPR_T_OR); | |
2182 | struct expr *k; | |
2183 | ||
2184 | LIST_FOR_EACH (k, node, &sub->andor) { | |
2185 | struct expr *and = expr_create_andor(EXPR_T_AND); | |
2186 | struct expr *m; | |
2187 | ||
2188 | LIST_FOR_EACH (m, node, &expr->andor) { | |
2189 | struct expr *term = m == sub ? k : m; | |
2190 | if (term->type == EXPR_T_AND) { | |
2191 | struct expr *p; | |
2192 | ||
2193 | LIST_FOR_EACH (p, node, &term->andor) { | |
2194 | struct expr *new = expr_clone(p); | |
417e7e66 | 2195 | ovs_list_push_back(&and->andor, &new->node); |
e0840f11 BP |
2196 | } |
2197 | } else { | |
2198 | struct expr *new = expr_clone(term); | |
417e7e66 | 2199 | ovs_list_push_back(&and->andor, &new->node); |
e0840f11 BP |
2200 | } |
2201 | } | |
417e7e66 | 2202 | ovs_list_push_back(&or->andor, &and->node); |
e0840f11 BP |
2203 | } |
2204 | expr_destroy(expr); | |
2205 | return expr_normalize_or(or); | |
2206 | } | |
2207 | } | |
2208 | return expr; | |
2209 | } | |
2210 | ||
2211 | static struct expr * | |
2212 | expr_normalize_or(struct expr *expr) | |
2213 | { | |
2214 | struct expr *sub, *next; | |
2215 | ||
2216 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
2217 | if (sub->type == EXPR_T_AND) { | |
417e7e66 | 2218 | ovs_list_remove(&sub->node); |
e0840f11 BP |
2219 | |
2220 | struct expr *new = expr_normalize_and(sub); | |
2221 | if (new->type == EXPR_T_BOOLEAN) { | |
2222 | if (new->boolean) { | |
2223 | expr_destroy(expr); | |
2224 | return new; | |
2225 | } | |
2226 | free(new); | |
2227 | } else { | |
2228 | expr_insert_andor(expr, next, new); | |
2229 | } | |
2230 | } else { | |
2231 | ovs_assert(sub->type == EXPR_T_CMP); | |
2232 | } | |
2233 | } | |
417e7e66 | 2234 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
2235 | free(expr); |
2236 | return expr_create_boolean(false); | |
2237 | } | |
417e7e66 BW |
2238 | if (ovs_list_is_short(&expr->andor)) { |
2239 | struct expr *sub = expr_from_node(ovs_list_pop_front(&expr->andor)); | |
e0840f11 BP |
2240 | free(expr); |
2241 | return sub; | |
2242 | } | |
2243 | ||
2244 | return expr; | |
2245 | } | |
2246 | ||
2247 | /* Takes ownership of 'expr', which is either a constant "true" or "false" or | |
2248 | * an expression in terms of only relationals, AND, and OR. Returns either a | |
2249 | * constant "true" or "false" or 'expr' reduced to OR(AND(clause)) where a | |
2250 | * clause is a cmp or a disjunction of cmps on a single field. This form is | |
2251 | * significant because it is a form that can be directly converted to OpenFlow | |
2252 | * flows with the Open vSwitch "conjunctive match" extension. | |
2253 | * | |
2254 | * 'expr' must already have been simplified, with expr_simplify(). */ | |
2255 | struct expr * | |
2256 | expr_normalize(struct expr *expr) | |
2257 | { | |
2258 | switch (expr->type) { | |
2259 | case EXPR_T_CMP: | |
2260 | return expr; | |
2261 | ||
2262 | case EXPR_T_AND: | |
2263 | return expr_normalize_and(expr); | |
2264 | ||
2265 | case EXPR_T_OR: | |
2266 | return expr_normalize_or(expr); | |
2267 | ||
2268 | case EXPR_T_BOOLEAN: | |
2269 | return expr; | |
2270 | } | |
2271 | OVS_NOT_REACHED(); | |
2272 | } | |
2273 | \f | |
2274 | /* Creates, initializes, and returns a new 'struct expr_match'. If 'm' is | |
2275 | * nonnull then it is copied into the new expr_match, otherwise the new | |
2276 | * expr_match's 'match' member is initialized to a catch-all match for the | |
2277 | * caller to refine in-place. | |
2278 | * | |
2279 | * If 'conj_id' is nonzero, adds one conjunction based on 'conj_id', 'clause', | |
2280 | * and 'n_clauses' to the returned 'struct expr_match', otherwise the | |
2281 | * expr_match will not have any conjunctions. | |
2282 | * | |
2283 | * The caller should use expr_match_add() to add the expr_match to a hash table | |
2284 | * after it is finalized. */ | |
2285 | static struct expr_match * | |
2286 | expr_match_new(const struct match *m, uint8_t clause, uint8_t n_clauses, | |
2287 | uint32_t conj_id) | |
2288 | { | |
2289 | struct expr_match *match = xmalloc(sizeof *match); | |
2290 | if (m) { | |
2291 | match->match = *m; | |
2292 | } else { | |
2293 | match_init_catchall(&match->match); | |
2294 | } | |
2295 | if (conj_id) { | |
2296 | match->conjunctions = xmalloc(sizeof *match->conjunctions); | |
2297 | match->conjunctions[0].id = conj_id; | |
2298 | match->conjunctions[0].clause = clause; | |
2299 | match->conjunctions[0].n_clauses = n_clauses; | |
2300 | match->n = 1; | |
2301 | match->allocated = 1; | |
2302 | } else { | |
2303 | match->conjunctions = NULL; | |
2304 | match->n = 0; | |
2305 | match->allocated = 0; | |
2306 | } | |
2307 | return match; | |
2308 | } | |
2309 | ||
2310 | /* Adds 'match' to hash table 'matches', which becomes the new owner of | |
2311 | * 'match'. | |
2312 | * | |
2313 | * This might actually destroy 'match' because it gets merged together with | |
2314 | * some existing conjunction.*/ | |
2315 | static void | |
2316 | expr_match_add(struct hmap *matches, struct expr_match *match) | |
2317 | { | |
2318 | uint32_t hash = match_hash(&match->match, 0); | |
2319 | struct expr_match *m; | |
2320 | ||
2321 | HMAP_FOR_EACH_WITH_HASH (m, hmap_node, hash, matches) { | |
2322 | if (match_equal(&m->match, &match->match)) { | |
2323 | if (!m->n || !match->n) { | |
2324 | free(m->conjunctions); | |
2325 | m->conjunctions = NULL; | |
2326 | m->n = 0; | |
2327 | m->allocated = 0; | |
2328 | } else { | |
2329 | ovs_assert(match->n == 1); | |
2330 | if (m->n >= m->allocated) { | |
2331 | m->conjunctions = x2nrealloc(m->conjunctions, | |
2332 | &m->allocated, | |
2333 | sizeof *m->conjunctions); | |
2334 | } | |
2335 | m->conjunctions[m->n++] = match->conjunctions[0]; | |
2336 | } | |
2337 | free(match->conjunctions); | |
2338 | free(match); | |
2339 | return; | |
2340 | } | |
2341 | } | |
2342 | ||
2343 | hmap_insert(matches, &match->hmap_node, hash); | |
2344 | } | |
2345 | ||
f386a8a7 | 2346 | static bool |
f1c16a85 BP |
2347 | constrain_match(const struct expr *expr, |
2348 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2349 | unsigned int *portp), | |
2350 | const void *aux, struct match *m) | |
e0840f11 BP |
2351 | { |
2352 | ovs_assert(expr->type == EXPR_T_CMP); | |
f386a8a7 BP |
2353 | if (expr->cmp.symbol->width) { |
2354 | mf_mask_subfield(expr->cmp.symbol->field, &expr->cmp.value, | |
2355 | &expr->cmp.mask, m); | |
2356 | } else { | |
f1c16a85 BP |
2357 | unsigned int port; |
2358 | if (!lookup_port(aux, expr->cmp.string, &port)) { | |
f386a8a7 BP |
2359 | return false; |
2360 | } | |
2361 | ||
2362 | struct mf_subfield sf; | |
2363 | sf.field = expr->cmp.symbol->field; | |
2364 | sf.ofs = 0; | |
2365 | sf.n_bits = expr->cmp.symbol->field->n_bits; | |
2366 | ||
2367 | union mf_subvalue x; | |
2368 | memset(&x, 0, sizeof x); | |
f1c16a85 | 2369 | x.integer = htonll(port); |
f386a8a7 BP |
2370 | |
2371 | mf_write_subfield(&sf, &x, m); | |
2372 | } | |
2373 | return true; | |
e0840f11 BP |
2374 | } |
2375 | ||
f386a8a7 | 2376 | static bool |
f1c16a85 BP |
2377 | add_disjunction(const struct expr *or, |
2378 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2379 | unsigned int *portp), | |
2380 | const void *aux, | |
f386a8a7 BP |
2381 | struct match *m, uint8_t clause, uint8_t n_clauses, |
2382 | uint32_t conj_id, struct hmap *matches) | |
e0840f11 BP |
2383 | { |
2384 | struct expr *sub; | |
f386a8a7 | 2385 | int n = 0; |
e0840f11 BP |
2386 | |
2387 | ovs_assert(or->type == EXPR_T_OR); | |
2388 | LIST_FOR_EACH (sub, node, &or->andor) { | |
2389 | struct expr_match *match = expr_match_new(m, clause, n_clauses, | |
2390 | conj_id); | |
f1c16a85 | 2391 | if (constrain_match(sub, lookup_port, aux, &match->match)) { |
f386a8a7 BP |
2392 | expr_match_add(matches, match); |
2393 | n++; | |
2394 | } else { | |
2395 | free(match->conjunctions); | |
2396 | free(match); | |
2397 | } | |
e0840f11 | 2398 | } |
f386a8a7 BP |
2399 | |
2400 | /* If n == 1, then this didn't really need to be a disjunction. Oh well, | |
2401 | * that shouldn't happen much. */ | |
2402 | return n > 0; | |
e0840f11 BP |
2403 | } |
2404 | ||
2405 | static void | |
f1c16a85 BP |
2406 | add_conjunction(const struct expr *and, |
2407 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2408 | unsigned int *portp), | |
2409 | const void *aux, uint32_t *n_conjsp, struct hmap *matches) | |
e0840f11 BP |
2410 | { |
2411 | struct match match; | |
2412 | int n_clauses = 0; | |
2413 | struct expr *sub; | |
2414 | ||
2415 | match_init_catchall(&match); | |
2416 | ||
2417 | ovs_assert(and->type == EXPR_T_AND); | |
2418 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2419 | switch (sub->type) { | |
2420 | case EXPR_T_CMP: | |
f1c16a85 | 2421 | if (!constrain_match(sub, lookup_port, aux, &match)) { |
f386a8a7 BP |
2422 | return; |
2423 | } | |
e0840f11 BP |
2424 | break; |
2425 | case EXPR_T_OR: | |
2426 | n_clauses++; | |
2427 | break; | |
2428 | case EXPR_T_AND: | |
2429 | case EXPR_T_BOOLEAN: | |
2430 | OVS_NOT_REACHED(); | |
2431 | } | |
2432 | } | |
2433 | ||
2434 | if (!n_clauses) { | |
2435 | expr_match_add(matches, expr_match_new(&match, 0, 0, 0)); | |
2436 | } else if (n_clauses == 1) { | |
2437 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2438 | if (sub->type == EXPR_T_OR) { | |
f1c16a85 BP |
2439 | add_disjunction(sub, lookup_port, aux, &match, 0, 0, 0, |
2440 | matches); | |
e0840f11 BP |
2441 | } |
2442 | } | |
2443 | } else { | |
2444 | int clause = 0; | |
2445 | (*n_conjsp)++; | |
2446 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2447 | if (sub->type == EXPR_T_OR) { | |
f1c16a85 | 2448 | if (!add_disjunction(sub, lookup_port, aux, &match, clause++, |
f386a8a7 BP |
2449 | n_clauses, *n_conjsp, matches)) { |
2450 | /* This clause can't ever match, so we might as well skip | |
2451 | * adding the other clauses--the overall disjunctive flow | |
2452 | * can't ever match. Ideally we would also back out all of | |
2453 | * the clauses we already added, but that seems like a lot | |
2454 | * of trouble for a case that might never occur in | |
2455 | * practice. */ | |
2456 | return; | |
2457 | } | |
e0840f11 BP |
2458 | } |
2459 | } | |
40e07b2a BP |
2460 | |
2461 | /* Add the flow that matches on conj_id. */ | |
2462 | match_set_conj_id(&match, *n_conjsp); | |
2463 | expr_match_add(matches, expr_match_new(&match, 0, 0, 0)); | |
e0840f11 BP |
2464 | } |
2465 | } | |
2466 | ||
2467 | static void | |
f1c16a85 BP |
2468 | add_cmp_flow(const struct expr *cmp, |
2469 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2470 | unsigned int *portp), | |
2471 | const void *aux, struct hmap *matches) | |
e0840f11 BP |
2472 | { |
2473 | struct expr_match *m = expr_match_new(NULL, 0, 0, 0); | |
f1c16a85 | 2474 | if (constrain_match(cmp, lookup_port, aux, &m->match)) { |
f386a8a7 BP |
2475 | expr_match_add(matches, m); |
2476 | } else { | |
2477 | free(m); | |
2478 | } | |
e0840f11 BP |
2479 | } |
2480 | ||
2481 | /* Converts 'expr', which must be in the form returned by expr_normalize(), to | |
2482 | * a collection of Open vSwitch flows in 'matches', which this function | |
f386a8a7 BP |
2483 | * initializes to an hmap of "struct expr_match" structures. Returns the |
2484 | * number of conjunctive match IDs consumed by 'matches', which uses | |
2485 | * conjunctive match IDs beginning with 0; the caller must offset or remap them | |
2486 | * into the desired range as necessary. | |
2487 | * | |
40e07b2a BP |
2488 | * The matches inserted into 'matches' will be of three distinct kinds: |
2489 | * | |
2490 | * - Ordinary flows. The caller should add these OpenFlow flows with | |
2491 | * its desired actions. | |
2492 | * | |
2493 | * - Conjunctive flows, distinguished by 'n > 0' in the expr_match | |
2494 | * structure. The caller should add these OpenFlow flows with the | |
2495 | * conjunction(id, k/n) actions as specified in the 'conjunctions' array, | |
2496 | * remapping the ids. | |
2497 | * | |
2498 | * - conj_id flows, distinguished by matching on the "conj_id" field. The | |
2499 | * caller should remap the conj_id and add the OpenFlow flow with its | |
2500 | * desired actions. | |
2501 | * | |
f1c16a85 BP |
2502 | * 'lookup_port' must be a function to map from a port name to a port number. |
2503 | * When successful, 'lookup_port' stores the port number into '*portp' and | |
2504 | * returns true; when there is no port by the given name, it returns false. | |
2505 | * 'aux' is passed to 'lookup_port' as auxiliary data. Any comparisons against | |
2506 | * string fields in 'expr' are translated into integers through this function. | |
2507 | * A comparison against a string that is not in 'ports' acts like a Boolean | |
2508 | * "false"; that is, it will always fail to match. For a simple expression, | |
2509 | * this means that the overall expression always fails to match, but an | |
2510 | * expression with a disjunction on the string field might still match on other | |
2511 | * port names. | |
f386a8a7 BP |
2512 | * |
2513 | * (This treatment of string fields might be too simplistic in general, but it | |
2514 | * seems reasonable for now when string fields are used only for ports.) */ | |
e0840f11 | 2515 | uint32_t |
f1c16a85 BP |
2516 | expr_to_matches(const struct expr *expr, |
2517 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2518 | unsigned int *portp), | |
2519 | const void *aux, struct hmap *matches) | |
e0840f11 BP |
2520 | { |
2521 | uint32_t n_conjs = 0; | |
2522 | ||
2523 | hmap_init(matches); | |
2524 | switch (expr->type) { | |
2525 | case EXPR_T_CMP: | |
f1c16a85 | 2526 | add_cmp_flow(expr, lookup_port, aux, matches); |
e0840f11 BP |
2527 | break; |
2528 | ||
2529 | case EXPR_T_AND: | |
f1c16a85 | 2530 | add_conjunction(expr, lookup_port, aux, &n_conjs, matches); |
e0840f11 BP |
2531 | break; |
2532 | ||
2533 | case EXPR_T_OR: | |
2534 | if (expr_is_cmp(expr)) { | |
2535 | struct expr *sub; | |
2536 | ||
2537 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
f1c16a85 | 2538 | add_cmp_flow(sub, lookup_port, aux, matches); |
e0840f11 BP |
2539 | } |
2540 | } else { | |
2541 | struct expr *sub; | |
2542 | ||
2543 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2544 | if (sub->type == EXPR_T_AND) { | |
f1c16a85 | 2545 | add_conjunction(sub, lookup_port, aux, &n_conjs, matches); |
e0840f11 | 2546 | } else { |
f1c16a85 | 2547 | add_cmp_flow(sub, lookup_port, aux, matches); |
e0840f11 BP |
2548 | } |
2549 | } | |
2550 | } | |
2551 | break; | |
2552 | ||
2553 | case EXPR_T_BOOLEAN: | |
2554 | if (expr->boolean) { | |
2555 | struct expr_match *m = expr_match_new(NULL, 0, 0, 0); | |
2556 | expr_match_add(matches, m); | |
2557 | } else { | |
2558 | /* No match. */ | |
2559 | } | |
2560 | break; | |
2561 | } | |
2562 | return n_conjs; | |
2563 | } | |
f386a8a7 BP |
2564 | |
2565 | /* Destroys all of the 'struct expr_match'es in 'matches', as well as the | |
2566 | * 'matches' hmap itself. */ | |
2567 | void | |
2568 | expr_matches_destroy(struct hmap *matches) | |
2569 | { | |
4ec3d7c7 | 2570 | struct expr_match *m; |
f386a8a7 | 2571 | |
4ec3d7c7 | 2572 | HMAP_FOR_EACH_POP (m, hmap_node, matches) { |
f386a8a7 BP |
2573 | free(m->conjunctions); |
2574 | free(m); | |
2575 | } | |
2576 | hmap_destroy(matches); | |
2577 | } | |
2578 | ||
2579 | /* Prints a representation of the 'struct expr_match'es in 'matches' to | |
2580 | * 'stream'. */ | |
2581 | void | |
2582 | expr_matches_print(const struct hmap *matches, FILE *stream) | |
2583 | { | |
2584 | if (hmap_is_empty(matches)) { | |
2585 | fputs("(no flows)\n", stream); | |
2586 | return; | |
2587 | } | |
2588 | ||
2589 | const struct expr_match *m; | |
2590 | HMAP_FOR_EACH (m, hmap_node, matches) { | |
2591 | char *s = match_to_string(&m->match, OFP_DEFAULT_PRIORITY); | |
2592 | fputs(s, stream); | |
2593 | free(s); | |
2594 | ||
2595 | if (m->n) { | |
2596 | for (int i = 0; i < m->n; i++) { | |
2597 | const struct cls_conjunction *c = &m->conjunctions[i]; | |
2598 | fprintf(stream, "%c conjunction(%"PRIu32", %d/%d)", | |
2599 | i == 0 ? ':' : ',', c->id, c->clause, c->n_clauses); | |
2600 | } | |
2601 | } | |
2602 | putc('\n', stream); | |
2603 | } | |
2604 | } | |
e0840f11 BP |
2605 | \f |
2606 | /* Returns true if 'expr' honors the invariants for expressions (see the large | |
2607 | * comment above "struct expr" in expr.h), false otherwise. */ | |
2608 | bool | |
2609 | expr_honors_invariants(const struct expr *expr) | |
2610 | { | |
2611 | const struct expr *sub; | |
2612 | ||
2613 | switch (expr->type) { | |
2614 | case EXPR_T_CMP: | |
2615 | if (expr->cmp.symbol->width) { | |
2616 | for (int i = 0; i < ARRAY_SIZE(expr->cmp.value.be64); i++) { | |
2617 | if (expr->cmp.value.be64[i] & ~expr->cmp.mask.be64[i]) { | |
2618 | return false; | |
2619 | } | |
2620 | } | |
2621 | } | |
2622 | return true; | |
2623 | ||
2624 | case EXPR_T_AND: | |
2625 | case EXPR_T_OR: | |
417e7e66 | 2626 | if (ovs_list_is_short(&expr->andor)) { |
e0840f11 BP |
2627 | return false; |
2628 | } | |
2629 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2630 | if (sub->type == expr->type || !expr_honors_invariants(sub)) { | |
2631 | return false; | |
2632 | } | |
2633 | } | |
2634 | return true; | |
2635 | ||
2636 | case EXPR_T_BOOLEAN: | |
2637 | return true; | |
2638 | ||
2639 | default: | |
2640 | OVS_NOT_REACHED(); | |
2641 | } | |
2642 | } | |
2643 | ||
2644 | static bool | |
2645 | expr_is_normalized_and(const struct expr *expr) | |
2646 | { | |
2647 | /* XXX should also check that no symbol is repeated. */ | |
2648 | const struct expr *sub; | |
2649 | ||
2650 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2651 | if (!expr_is_cmp(sub)) { | |
2652 | return false; | |
2653 | } | |
2654 | } | |
2655 | return true; | |
2656 | } | |
2657 | ||
2658 | /* Returns true if 'expr' is in the form returned by expr_normalize(), false | |
2659 | * otherwise. */ | |
2660 | bool | |
2661 | expr_is_normalized(const struct expr *expr) | |
2662 | { | |
2663 | switch (expr->type) { | |
2664 | case EXPR_T_CMP: | |
2665 | return true; | |
2666 | ||
2667 | case EXPR_T_AND: | |
2668 | return expr_is_normalized_and(expr); | |
2669 | ||
2670 | case EXPR_T_OR: | |
2671 | if (!expr_is_cmp(expr)) { | |
2672 | const struct expr *sub; | |
2673 | ||
2674 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2675 | if (!expr_is_cmp(sub) && !expr_is_normalized_and(sub)) { | |
2676 | return false; | |
2677 | } | |
2678 | } | |
2679 | } | |
2680 | return true; | |
2681 | ||
2682 | case EXPR_T_BOOLEAN: | |
2683 | return true; | |
2684 | ||
2685 | default: | |
2686 | OVS_NOT_REACHED(); | |
2687 | } | |
2688 | } | |
3b7cb7e1 BP |
2689 | \f |
2690 | /* Action parsing helper. */ | |
2691 | ||
a20c96c6 BP |
2692 | /* Expands 'f' repeatedly as long as it has an expansion, that is, as long as |
2693 | * it is a subfield or a predicate. Adds any prerequisites for 'f' to | |
2694 | * '*prereqs'. | |
2695 | * | |
2696 | * If 'rw', verifies that 'f' is a read/write field. | |
2697 | * | |
a20c96c6 BP |
2698 | * Returns true if successful, false if an error was encountered (in which case |
2699 | * 'ctx->error' reports the particular error). */ | |
5ee054fb | 2700 | static bool |
ce57ea75 | 2701 | expand_symbol(struct expr_context *ctx, bool rw, |
a20c96c6 | 2702 | struct expr_field *f, struct expr **prereqsp) |
3b7cb7e1 | 2703 | { |
a20c96c6 BP |
2704 | const struct expr_symbol *orig_symbol = f->symbol; |
2705 | ||
5ee054fb | 2706 | if (f->symbol->expansion && f->symbol->level != EXPR_L_ORDINAL) { |
ce57ea75 BP |
2707 | expr_error(ctx, "Predicate symbol %s used where lvalue required.", |
2708 | f->symbol->name); | |
5ee054fb | 2709 | return false; |
3b7cb7e1 BP |
2710 | } |
2711 | ||
3b7cb7e1 BP |
2712 | for (;;) { |
2713 | /* Accumulate prerequisites. */ | |
5ee054fb | 2714 | if (f->symbol->prereqs) { |
3b7cb7e1 BP |
2715 | struct ovs_list nesting = OVS_LIST_INITIALIZER(&nesting); |
2716 | char *error; | |
2717 | struct expr *e; | |
5ee054fb | 2718 | e = parse_and_annotate(f->symbol->prereqs, ctx->symtab, &nesting, |
3b7cb7e1 BP |
2719 | &error); |
2720 | if (error) { | |
2721 | expr_error(ctx, "%s", error); | |
2722 | free(error); | |
5ee054fb | 2723 | return false; |
3b7cb7e1 | 2724 | } |
5ee054fb | 2725 | *prereqsp = expr_combine(EXPR_T_AND, *prereqsp, e); |
3b7cb7e1 BP |
2726 | } |
2727 | ||
2728 | /* If there's no expansion, we're done. */ | |
5ee054fb | 2729 | if (!f->symbol->expansion) { |
3b7cb7e1 BP |
2730 | break; |
2731 | } | |
2732 | ||
2733 | /* Expand. */ | |
2734 | struct expr_field expansion; | |
2735 | char *error; | |
5ee054fb | 2736 | if (!parse_field_from_string(f->symbol->expansion, ctx->symtab, |
3b7cb7e1 BP |
2737 | &expansion, &error)) { |
2738 | expr_error(ctx, "%s", error); | |
2739 | free(error); | |
5ee054fb | 2740 | return false; |
3b7cb7e1 | 2741 | } |
5ee054fb BP |
2742 | f->symbol = expansion.symbol; |
2743 | f->ofs += expansion.ofs; | |
3b7cb7e1 BP |
2744 | } |
2745 | ||
a20c96c6 BP |
2746 | if (rw && !f->symbol->field->writable) { |
2747 | expr_error(ctx, "Field %s is not modifiable.", orig_symbol->name); | |
2748 | return false; | |
2749 | } | |
2750 | ||
5ee054fb BP |
2751 | return true; |
2752 | } | |
2753 | ||
a20c96c6 BP |
2754 | static void |
2755 | mf_subfield_from_expr_field(const struct expr_field *f, struct mf_subfield *sf) | |
2756 | { | |
2757 | sf->field = f->symbol->field; | |
2758 | sf->ofs = f->ofs; | |
2759 | sf->n_bits = f->n_bits ? f->n_bits : f->symbol->field->n_bits; | |
2760 | } | |
2761 | ||
2762 | static void | |
2763 | init_stack_action(const struct expr_field *f, struct ofpact_stack *stack) | |
2764 | { | |
2765 | mf_subfield_from_expr_field(f, &stack->subfield); | |
2766 | } | |
2767 | ||
8fb72d29 BP |
2768 | static char * OVS_WARN_UNUSED_RESULT |
2769 | parse_assignment(struct lexer *lexer, struct expr_field *dst, | |
2770 | const struct shash *symtab, bool exchange, | |
f1c16a85 BP |
2771 | bool (*lookup_port)(const void *aux, const char *port_name, |
2772 | unsigned int *portp), | |
8fb72d29 BP |
2773 | const void *aux, struct ofpbuf *ofpacts, |
2774 | struct expr **prereqsp) | |
5ee054fb | 2775 | { |
8fb72d29 | 2776 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
5ee054fb BP |
2777 | struct expr *prereqs = NULL; |
2778 | ||
2779 | /* Parse destination and do basic checking. */ | |
8fb72d29 BP |
2780 | const struct expr_symbol *orig_dst = dst->symbol; |
2781 | if (!expand_symbol(&ctx, true, dst, &prereqs)) { | |
5ee054fb | 2782 | goto exit; |
3b7cb7e1 BP |
2783 | } |
2784 | ||
8fb72d29 | 2785 | if (exchange || ctx.lexer->token.type == LEX_T_ID) { |
5ee054fb | 2786 | struct expr_field src; |
8fb72d29 | 2787 | if (!parse_field(&ctx, &src)) { |
5ee054fb BP |
2788 | goto exit; |
2789 | } | |
2790 | const struct expr_symbol *orig_src = src.symbol; | |
8fb72d29 | 2791 | if (!expand_symbol(&ctx, exchange, &src, &prereqs)) { |
5ee054fb BP |
2792 | goto exit; |
2793 | } | |
2794 | ||
8fb72d29 | 2795 | if ((dst->symbol->width != 0) != (src.symbol->width != 0)) { |
a20c96c6 | 2796 | if (exchange) { |
8fb72d29 | 2797 | expr_error(&ctx, |
a20c96c6 BP |
2798 | "Can't exchange %s field (%s) with %s field (%s).", |
2799 | orig_dst->width ? "integer" : "string", | |
2800 | orig_dst->name, | |
2801 | orig_src->width ? "integer" : "string", | |
2802 | orig_src->name); | |
2803 | } else { | |
8fb72d29 BP |
2804 | expr_error(&ctx, |
2805 | "Can't assign %s field (%s) to %s field (%s).", | |
a20c96c6 BP |
2806 | orig_src->width ? "integer" : "string", |
2807 | orig_src->name, | |
2808 | orig_dst->width ? "integer" : "string", | |
2809 | orig_dst->name); | |
2810 | } | |
5ee054fb BP |
2811 | goto exit; |
2812 | } | |
2813 | ||
8fb72d29 | 2814 | if (dst->n_bits != src.n_bits) { |
a20c96c6 | 2815 | if (exchange) { |
8fb72d29 | 2816 | expr_error(&ctx, |
a20c96c6 | 2817 | "Can't exchange %d-bit field with %d-bit field.", |
8fb72d29 | 2818 | dst->n_bits, src.n_bits); |
a20c96c6 | 2819 | } else { |
8fb72d29 | 2820 | expr_error(&ctx, |
a20c96c6 | 2821 | "Can't assign %d-bit value to %d-bit destination.", |
8fb72d29 | 2822 | src.n_bits, dst->n_bits); |
a20c96c6 | 2823 | } |
5ee054fb | 2824 | goto exit; |
8fb72d29 BP |
2825 | } else if (!dst->n_bits && |
2826 | dst->symbol->field->n_bits != src.symbol->field->n_bits) { | |
2827 | expr_error(&ctx, "String fields %s and %s are incompatible for " | |
a20c96c6 BP |
2828 | "%s.", orig_dst->name, orig_src->name, |
2829 | exchange ? "exchange" : "assignment"); | |
5ee054fb | 2830 | goto exit; |
3b7cb7e1 BP |
2831 | } |
2832 | ||
a20c96c6 BP |
2833 | if (exchange) { |
2834 | init_stack_action(&src, ofpact_put_STACK_PUSH(ofpacts)); | |
8fb72d29 | 2835 | init_stack_action(dst, ofpact_put_STACK_PUSH(ofpacts)); |
a20c96c6 | 2836 | init_stack_action(&src, ofpact_put_STACK_POP(ofpacts)); |
8fb72d29 | 2837 | init_stack_action(dst, ofpact_put_STACK_POP(ofpacts)); |
a20c96c6 BP |
2838 | } else { |
2839 | struct ofpact_reg_move *move = ofpact_put_REG_MOVE(ofpacts); | |
2840 | mf_subfield_from_expr_field(&src, &move->src); | |
8fb72d29 | 2841 | mf_subfield_from_expr_field(dst, &move->dst); |
a20c96c6 | 2842 | } |
3b7cb7e1 | 2843 | } else { |
5ee054fb | 2844 | struct expr_constant_set cs; |
8fb72d29 | 2845 | if (!parse_constant_set(&ctx, &cs)) { |
5ee054fb BP |
2846 | goto exit; |
2847 | } | |
2848 | ||
8fb72d29 | 2849 | if (!type_check(&ctx, dst, &cs)) { |
5ee054fb BP |
2850 | goto exit_destroy_cs; |
2851 | } | |
2852 | if (cs.in_curlies) { | |
8fb72d29 | 2853 | expr_error(&ctx, "Assignments require a single value."); |
5ee054fb BP |
2854 | goto exit_destroy_cs; |
2855 | } | |
2856 | ||
2857 | union expr_constant *c = cs.values; | |
2858 | struct ofpact_set_field *sf = ofpact_put_SET_FIELD(ofpacts); | |
8fb72d29 BP |
2859 | sf->field = dst->symbol->field; |
2860 | if (dst->symbol->width) { | |
2861 | mf_subvalue_shift(&c->value, dst->ofs); | |
5ee054fb BP |
2862 | if (!c->masked) { |
2863 | memset(&c->mask, 0, sizeof c->mask); | |
8fb72d29 | 2864 | bitwise_one(&c->mask, sizeof c->mask, dst->ofs, dst->n_bits); |
5ee054fb | 2865 | } else { |
8fb72d29 | 2866 | mf_subvalue_shift(&c->mask, dst->ofs); |
5ee054fb BP |
2867 | } |
2868 | ||
2869 | memcpy(&sf->value, | |
2870 | &c->value.u8[sizeof c->value - sf->field->n_bytes], | |
2871 | sf->field->n_bytes); | |
2872 | memcpy(&sf->mask, | |
2873 | &c->mask.u8[sizeof c->mask - sf->field->n_bytes], | |
2874 | sf->field->n_bytes); | |
2875 | } else { | |
f1c16a85 BP |
2876 | uint32_t port; |
2877 | if (!lookup_port(aux, c->string, &port)) { | |
2878 | port = 0; | |
2879 | } | |
5ee054fb BP |
2880 | bitwise_put(port, &sf->value, |
2881 | sf->field->n_bytes, 0, sf->field->n_bits); | |
b4970837 | 2882 | bitwise_one(&sf->mask, sf->field->n_bytes, 0, sf->field->n_bits); |
5ee054fb BP |
2883 | } |
2884 | ||
2885 | exit_destroy_cs: | |
2886 | expr_constant_set_destroy(&cs); | |
3b7cb7e1 BP |
2887 | } |
2888 | ||
3b7cb7e1 | 2889 | exit: |
8fb72d29 BP |
2890 | if (ctx.error) { |
2891 | expr_destroy(prereqs); | |
2892 | prereqs = NULL; | |
2893 | } | |
2894 | *prereqsp = prereqs; | |
2895 | return ctx.error; | |
3b7cb7e1 BP |
2896 | } |
2897 | ||
2898 | /* A helper for actions_parse(), to parse an OVN assignment action in the form | |
8fb72d29 BP |
2899 | * "field = value" or "field = field2" into 'ofpacts'. The caller must have |
2900 | * already parsed and skipped the left-hand side "field =" and pass in the | |
2901 | * field as 'dst'. Other parameters and return value match those for | |
2902 | * actions_parse(). */ | |
2903 | char * OVS_WARN_UNUSED_RESULT | |
2904 | expr_parse_assignment(struct lexer *lexer, struct expr_field *dst, | |
2905 | const struct shash *symtab, | |
f1c16a85 BP |
2906 | bool (*lookup_port)(const void *aux, |
2907 | const char *port_name, | |
2908 | unsigned int *portp), | |
2909 | const void *aux, | |
3b7cb7e1 | 2910 | struct ofpbuf *ofpacts, struct expr **prereqsp) |
8fb72d29 BP |
2911 | { |
2912 | return parse_assignment(lexer, dst, symtab, false, lookup_port, aux, | |
2913 | ofpacts, prereqsp); | |
2914 | } | |
2915 | ||
2916 | /* A helper for actions_parse(), to parse an OVN exchange action in the form | |
2917 | * "field1 <-> field2" into 'ofpacts'. The caller must have already parsed and | |
2918 | * skipped the left-hand side "field1 <->" and pass in 'field1'. Other | |
2919 | * parameters and return value match those for actions_parse(). */ | |
2920 | char * OVS_WARN_UNUSED_RESULT | |
2921 | expr_parse_exchange(struct lexer *lexer, struct expr_field *field, | |
2922 | const struct shash *symtab, | |
2923 | bool (*lookup_port)(const void *aux, | |
2924 | const char *port_name, | |
2925 | unsigned int *portp), | |
2926 | const void *aux, | |
2927 | struct ofpbuf *ofpacts, struct expr **prereqsp) | |
2928 | { | |
2929 | return parse_assignment(lexer, field, symtab, true, lookup_port, aux, | |
2930 | ofpacts, prereqsp); | |
2931 | } | |
2932 | ||
2933 | /* Parses a field or subfield from 'lexer' into 'field', obtaining field names | |
2934 | * from 'symtab'. Returns NULL if successful, otherwise an error message owned | |
2935 | * by the caller. */ | |
2936 | char * OVS_WARN_UNUSED_RESULT | |
2937 | expr_parse_field(struct lexer *lexer, const struct shash *symtab, | |
2938 | struct expr_field *field) | |
3b7cb7e1 | 2939 | { |
1998e474 | 2940 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
8fb72d29 BP |
2941 | if (!parse_field(&ctx, field)) { |
2942 | memset(field, 0, sizeof *field); | |
3b7cb7e1 | 2943 | } |
3b7cb7e1 BP |
2944 | return ctx.error; |
2945 | } | |
0bac7164 | 2946 | |
8fb72d29 BP |
2947 | /* Takes 'field', which was presumably parsed by expr_parse_field(), and |
2948 | * converts it into mf_subfield 'sf' and a set of prerequisites in '*prereqsp'. | |
2949 | * | |
2950 | * 'n_bits' specifies the number of bits that the field must have, and 0 | |
2951 | * indicates a string field; reports an error if 'field' has a different type | |
2952 | * or width. If 'rw' is true, it is an error if 'field' is read-only. Uses | |
2953 | * 'symtab 'for expanding references and 'lexer' for error reporting. | |
2954 | * | |
2955 | * Returns NULL if successful, otherwise an error message owned by the | |
2956 | * caller. */ | |
2957 | char * OVS_WARN_UNUSED_RESULT | |
2958 | expr_expand_field(struct lexer *lexer, const struct shash *symtab, | |
2959 | const struct expr_field *orig_field, int n_bits, bool rw, | |
2960 | struct mf_subfield *sf, struct expr **prereqsp) | |
0bac7164 | 2961 | { |
1998e474 | 2962 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
0bac7164 | 2963 | struct expr *prereqs = NULL; |
0bac7164 | 2964 | |
8fb72d29 | 2965 | struct expr_field field = *orig_field; |
0bac7164 BP |
2966 | if (!expand_symbol(&ctx, rw, &field, &prereqs)) { |
2967 | goto exit; | |
2968 | } | |
8fb72d29 | 2969 | ovs_assert(field.n_bits == orig_field->n_bits); |
0bac7164 BP |
2970 | |
2971 | if (n_bits != field.n_bits) { | |
2972 | if (n_bits && field.n_bits) { | |
2973 | expr_error(&ctx, "Cannot use %d-bit field %s[%d..%d] " | |
2974 | "where %d-bit field is required.", | |
8fb72d29 BP |
2975 | orig_field->n_bits, orig_field->symbol->name, |
2976 | orig_field->ofs, | |
2977 | orig_field->ofs + orig_field->n_bits - 1, n_bits); | |
0bac7164 BP |
2978 | } else if (n_bits) { |
2979 | expr_error(&ctx, "Cannot use string field %s where numeric " | |
2980 | "field is required.", | |
8fb72d29 | 2981 | orig_field->symbol->name); |
0bac7164 BP |
2982 | } else { |
2983 | expr_error(&ctx, "Cannot use numeric field %s where string " | |
2984 | "field is required.", | |
8fb72d29 | 2985 | orig_field->symbol->name); |
0bac7164 BP |
2986 | } |
2987 | } | |
2988 | ||
2989 | exit: | |
2990 | if (!ctx.error) { | |
2991 | mf_subfield_from_expr_field(&field, sf); | |
2992 | *prereqsp = prereqs; | |
2993 | } else { | |
2994 | memset(sf, 0, sizeof *sf); | |
2995 | expr_destroy(prereqs); | |
2996 | *prereqsp = NULL; | |
2997 | } | |
2998 | return ctx.error; | |
2999 | } | |
42814145 NS |
3000 | |
3001 | char * OVS_WARN_UNUSED_RESULT | |
3002 | expr_parse_constant_set(struct lexer *lexer, const struct shash *symtab, | |
3003 | struct expr_constant_set *cs) | |
3004 | { | |
3005 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; | |
3006 | parse_constant_set(&ctx, cs); | |
3007 | return ctx.error; | |
3008 | } |