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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 | |
738 | = shash_find_data(ctx->macros, ctx->lexer->token.s); | |
739 | if (!addr_set) { | |
740 | expr_syntax_error(ctx, "expecting address set name."); | |
741 | return false; | |
742 | } | |
743 | ||
744 | if (!assign_constant_set_type(ctx, cs, EXPR_C_INTEGER)) { | |
745 | return false; | |
746 | } | |
747 | ||
748 | size_t n_values = cs->n_values + addr_set->n_values; | |
749 | if (n_values >= *allocated_values) { | |
750 | cs->values = xrealloc(cs->values, n_values * sizeof *cs->values); | |
751 | *allocated_values = n_values; | |
752 | } | |
753 | for (size_t i = 0; i < addr_set->n_values; i++) { | |
754 | cs->values[cs->n_values++] = addr_set->values[i]; | |
755 | } | |
756 | ||
757 | return true; | |
758 | } | |
759 | ||
e0840f11 BP |
760 | static bool |
761 | parse_constant(struct expr_context *ctx, struct expr_constant_set *cs, | |
762 | size_t *allocated_values) | |
763 | { | |
764 | if (cs->n_values >= *allocated_values) { | |
765 | cs->values = x2nrealloc(cs->values, allocated_values, | |
766 | sizeof *cs->values); | |
767 | } | |
768 | ||
769 | if (ctx->lexer->token.type == LEX_T_STRING) { | |
770 | if (!assign_constant_set_type(ctx, cs, EXPR_C_STRING)) { | |
771 | return false; | |
772 | } | |
773 | cs->values[cs->n_values++].string = xstrdup(ctx->lexer->token.s); | |
774 | lexer_get(ctx->lexer); | |
775 | return true; | |
776 | } else if (ctx->lexer->token.type == LEX_T_INTEGER || | |
777 | ctx->lexer->token.type == LEX_T_MASKED_INTEGER) { | |
778 | if (!assign_constant_set_type(ctx, cs, EXPR_C_INTEGER)) { | |
779 | return false; | |
780 | } | |
781 | ||
782 | union expr_constant *c = &cs->values[cs->n_values++]; | |
783 | c->value = ctx->lexer->token.value; | |
784 | c->format = ctx->lexer->token.format; | |
785 | c->masked = ctx->lexer->token.type == LEX_T_MASKED_INTEGER; | |
786 | if (c->masked) { | |
787 | c->mask = ctx->lexer->token.mask; | |
788 | } | |
789 | lexer_get(ctx->lexer); | |
790 | return true; | |
2c5cbb15 RB |
791 | } else if (ctx->lexer->token.type == LEX_T_MACRO) { |
792 | if (!parse_macros(ctx, cs, allocated_values)) { | |
793 | return false; | |
794 | } | |
795 | lexer_get(ctx->lexer); | |
796 | return true; | |
e0840f11 BP |
797 | } else { |
798 | expr_syntax_error(ctx, "expecting constant."); | |
799 | return false; | |
800 | } | |
801 | } | |
802 | ||
803 | /* Parses a single or {}-enclosed set of integer or string constants into 'cs', | |
804 | * which the caller need not have initialized. Returns true on success, in | |
805 | * which case the caller owns 'cs', false on failure, in which case 'cs' is | |
806 | * indeterminate. */ | |
807 | static bool | |
808 | parse_constant_set(struct expr_context *ctx, struct expr_constant_set *cs) | |
809 | { | |
810 | size_t allocated_values = 0; | |
811 | bool ok; | |
812 | ||
813 | memset(cs, 0, sizeof *cs); | |
814 | if (lexer_match(ctx->lexer, LEX_T_LCURLY)) { | |
815 | ok = true; | |
816 | cs->in_curlies = true; | |
817 | do { | |
818 | if (!parse_constant(ctx, cs, &allocated_values)) { | |
819 | ok = false; | |
820 | break; | |
821 | } | |
822 | lexer_match(ctx->lexer, LEX_T_COMMA); | |
823 | } while (!lexer_match(ctx->lexer, LEX_T_RCURLY)); | |
824 | } else { | |
825 | ok = parse_constant(ctx, cs, &allocated_values); | |
826 | } | |
827 | if (!ok) { | |
828 | expr_constant_set_destroy(cs); | |
829 | } | |
830 | return ok; | |
831 | } | |
832 | ||
42814145 | 833 | void |
e0840f11 BP |
834 | expr_constant_set_destroy(struct expr_constant_set *cs) |
835 | { | |
836 | if (cs) { | |
837 | if (cs->type == EXPR_C_STRING) { | |
838 | for (size_t i = 0; i < cs->n_values; i++) { | |
839 | free(cs->values[i].string); | |
840 | } | |
841 | } | |
842 | free(cs->values); | |
843 | } | |
844 | } | |
845 | ||
2c5cbb15 RB |
846 | /* Adds a macro named 'name' to 'macros', replacing any existing macro with the |
847 | * given name. */ | |
848 | void | |
849 | expr_macros_add(struct shash *macros, const char *name, | |
850 | const char *const *values, size_t n_values) | |
851 | { | |
852 | /* Replace any existing entry for this name. */ | |
853 | expr_macros_remove(macros, name); | |
854 | ||
855 | struct expr_constant_set *cs = xzalloc(sizeof *cs); | |
856 | cs->type = EXPR_C_INTEGER; | |
857 | cs->in_curlies = true; | |
858 | cs->n_values = 0; | |
859 | cs->values = xmalloc(n_values * sizeof *cs->values); | |
860 | for (size_t i = 0; i < n_values; i++) { | |
861 | /* Use the lexer to convert each macro into the proper | |
862 | * integer format. */ | |
863 | struct lexer lex; | |
864 | lexer_init(&lex, values[i]); | |
865 | lexer_get(&lex); | |
866 | if (lex.token.type != LEX_T_INTEGER | |
867 | && lex.token.type != LEX_T_MASKED_INTEGER) { | |
868 | VLOG_WARN("Invalid address set entry: '%s', token type: %d", | |
869 | values[i], lex.token.type); | |
870 | } else { | |
871 | union expr_constant *c = &cs->values[cs->n_values++]; | |
872 | c->value = lex.token.value; | |
873 | c->format = lex.token.format; | |
874 | c->masked = lex.token.type == LEX_T_MASKED_INTEGER; | |
875 | if (c->masked) { | |
876 | c->mask = lex.token.mask; | |
877 | } | |
878 | } | |
879 | lexer_destroy(&lex); | |
880 | } | |
881 | ||
882 | shash_add(macros, name, cs); | |
883 | } | |
884 | ||
885 | void | |
886 | expr_macros_remove(struct shash *macros, const char *name) | |
887 | { | |
888 | struct expr_constant_set *cs = shash_find_and_delete(macros, name); | |
889 | if (cs) { | |
890 | expr_constant_set_destroy(cs); | |
891 | free(cs); | |
892 | } | |
893 | } | |
894 | ||
895 | /* Destroy all contents of 'macros'. */ | |
896 | void | |
897 | expr_macros_destroy(struct shash *macros) | |
898 | { | |
899 | struct shash_node *node, *next; | |
900 | ||
901 | SHASH_FOR_EACH_SAFE (node, next, macros) { | |
902 | struct expr_constant_set *cs = node->data; | |
903 | ||
904 | shash_delete(macros, node); | |
905 | expr_constant_set_destroy(cs); | |
906 | } | |
907 | } | |
908 | ||
e0840f11 BP |
909 | static struct expr * |
910 | expr_parse_primary(struct expr_context *ctx, bool *atomic) | |
911 | { | |
912 | *atomic = false; | |
913 | if (lexer_match(ctx->lexer, LEX_T_LPAREN)) { | |
914 | struct expr *e = expr_parse__(ctx); | |
915 | if (!lexer_match(ctx->lexer, LEX_T_RPAREN)) { | |
916 | expr_destroy(e); | |
917 | expr_syntax_error(ctx, "expecting `)'."); | |
918 | return NULL; | |
919 | } | |
920 | *atomic = true; | |
921 | return e; | |
922 | } | |
923 | ||
924 | if (ctx->lexer->token.type == LEX_T_ID) { | |
925 | struct expr_field f; | |
926 | enum expr_relop r; | |
927 | struct expr_constant_set c; | |
928 | ||
929 | if (!parse_field(ctx, &f)) { | |
930 | return NULL; | |
931 | } | |
932 | ||
933 | if (!expr_relop_from_token(ctx->lexer->token.type, &r)) { | |
76da94b5 BP |
934 | if (!f.n_bits || ctx->lexer->token.type == LEX_T_EQUALS) { |
935 | expr_syntax_error(ctx, "expecting relational operator."); | |
936 | return NULL; | |
937 | } else if (f.n_bits > 1 && !ctx->not) { | |
e0840f11 | 938 | expr_error(ctx, "Explicit `!= 0' is required for inequality " |
76da94b5 | 939 | "test of multibit field against 0."); |
e0840f11 BP |
940 | return NULL; |
941 | } | |
942 | ||
943 | *atomic = true; | |
944 | ||
945 | union expr_constant *cst = xzalloc(sizeof *cst); | |
946 | cst->format = LEX_F_HEXADECIMAL; | |
947 | cst->masked = false; | |
948 | ||
949 | c.type = EXPR_C_INTEGER; | |
950 | c.values = cst; | |
951 | c.n_values = 1; | |
952 | c.in_curlies = false; | |
953 | return make_cmp(ctx, &f, EXPR_R_NE, &c); | |
954 | } else if (parse_relop(ctx, &r) && parse_constant_set(ctx, &c)) { | |
955 | return make_cmp(ctx, &f, r, &c); | |
956 | } else { | |
957 | return NULL; | |
958 | } | |
959 | } else { | |
960 | struct expr_constant_set c1; | |
961 | if (!parse_constant_set(ctx, &c1)) { | |
962 | return NULL; | |
963 | } | |
964 | ||
965 | if (!expr_relop_from_token(ctx->lexer->token.type, NULL) | |
966 | && c1.n_values == 1 | |
967 | && c1.type == EXPR_C_INTEGER | |
968 | && c1.values[0].format == LEX_F_DECIMAL | |
969 | && !c1.values[0].masked | |
970 | && !c1.in_curlies) { | |
971 | uint64_t x = ntohll(c1.values[0].value.integer); | |
972 | if (x <= 1) { | |
973 | *atomic = true; | |
974 | expr_constant_set_destroy(&c1); | |
975 | return expr_create_boolean(x); | |
976 | } | |
977 | } | |
978 | ||
979 | enum expr_relop r1; | |
980 | struct expr_field f; | |
981 | if (!parse_relop(ctx, &r1) || !parse_field(ctx, &f)) { | |
982 | expr_constant_set_destroy(&c1); | |
983 | return NULL; | |
984 | } | |
985 | ||
986 | if (!expr_relop_from_token(ctx->lexer->token.type, NULL)) { | |
987 | return make_cmp(ctx, &f, expr_relop_turn(r1), &c1); | |
988 | } | |
989 | ||
990 | enum expr_relop r2; | |
991 | struct expr_constant_set c2; | |
992 | if (!parse_relop(ctx, &r2) || !parse_constant_set(ctx, &c2)) { | |
993 | expr_constant_set_destroy(&c1); | |
994 | return NULL; | |
995 | } else { | |
996 | /* Reject "1 == field == 2", "1 < field > 2", and so on. */ | |
997 | if (!(((r1 == EXPR_R_LT || r1 == EXPR_R_LE) && | |
998 | (r2 == EXPR_R_LT || r2 == EXPR_R_LE)) || | |
999 | ((r1 == EXPR_R_GT || r1 == EXPR_R_GE) && | |
1000 | (r2 == EXPR_R_GT || r2 == EXPR_R_GE)))) { | |
1001 | expr_error(ctx, "Range expressions must have the form " | |
1002 | "`x < field < y' or `x > field > y', with each " | |
1003 | "`<' optionally replaced by `<=' or `>' by `>=')."); | |
1004 | expr_constant_set_destroy(&c1); | |
1005 | expr_constant_set_destroy(&c2); | |
1006 | return NULL; | |
1007 | } | |
1008 | ||
1009 | struct expr *e1 = make_cmp(ctx, &f, expr_relop_turn(r1), &c1); | |
1010 | struct expr *e2 = make_cmp(ctx, &f, r2, &c2); | |
1011 | if (ctx->error) { | |
1012 | expr_destroy(e1); | |
1013 | expr_destroy(e2); | |
1014 | return NULL; | |
1015 | } | |
1016 | return expr_combine(EXPR_T_AND, e1, e2); | |
1017 | } | |
1018 | } | |
1019 | } | |
1020 | ||
1021 | static struct expr * | |
1022 | expr_parse_not(struct expr_context *ctx) | |
1023 | { | |
1024 | bool atomic; | |
1025 | ||
1026 | if (lexer_match(ctx->lexer, LEX_T_LOG_NOT)) { | |
1027 | ctx->not = !ctx->not; | |
1028 | struct expr *expr = expr_parse_primary(ctx, &atomic); | |
1029 | ctx->not = !ctx->not; | |
1030 | ||
1031 | if (expr) { | |
1032 | if (!atomic) { | |
1033 | expr_error(ctx, "Missing parentheses around operand of !."); | |
1034 | expr_destroy(expr); | |
1035 | return NULL; | |
1036 | } | |
1037 | expr_not(expr); | |
1038 | } | |
1039 | return expr; | |
1040 | } else { | |
1041 | return expr_parse_primary(ctx, &atomic); | |
1042 | } | |
1043 | } | |
1044 | ||
1045 | struct expr * | |
1046 | expr_parse__(struct expr_context *ctx) | |
1047 | { | |
1048 | struct expr *e = expr_parse_not(ctx); | |
1049 | if (!e) { | |
1050 | return NULL; | |
1051 | } | |
1052 | ||
1053 | enum lex_type lex_type = ctx->lexer->token.type; | |
1054 | if (lex_type == LEX_T_LOG_AND || lex_type == LEX_T_LOG_OR) { | |
1055 | enum expr_type expr_type | |
1056 | = lex_type == LEX_T_LOG_AND ? EXPR_T_AND : EXPR_T_OR; | |
1057 | ||
1058 | lexer_get(ctx->lexer); | |
1059 | do { | |
1060 | struct expr *e2 = expr_parse_not(ctx); | |
1061 | if (!e2) { | |
1062 | expr_destroy(e); | |
1063 | return NULL; | |
1064 | } | |
1065 | e = expr_combine(expr_type, e, e2); | |
1066 | } while (lexer_match(ctx->lexer, lex_type)); | |
1067 | if (ctx->lexer->token.type == LEX_T_LOG_AND | |
1068 | || ctx->lexer->token.type == LEX_T_LOG_OR) { | |
1069 | expr_destroy(e); | |
1070 | expr_error(ctx, | |
1071 | "&& and || must be parenthesized when used together."); | |
1072 | return NULL; | |
1073 | } | |
1074 | } | |
1075 | return e; | |
1076 | } | |
1077 | ||
1078 | /* Parses an expression using the symbols in 'symtab' from 'lexer'. If | |
1079 | * successful, returns the new expression and sets '*errorp' to NULL. On | |
1080 | * failure, returns NULL and sets '*errorp' to an explanatory error message. | |
1081 | * The caller must eventually free the returned expression (with | |
1082 | * expr_destroy()) or error (with free()). */ | |
1083 | struct expr * | |
2c5cbb15 RB |
1084 | expr_parse(struct lexer *lexer, const struct shash *symtab, |
1085 | const struct shash *macros, char **errorp) | |
e0840f11 | 1086 | { |
2c5cbb15 RB |
1087 | struct expr_context ctx = { .lexer = lexer, |
1088 | .symtab = symtab, | |
1089 | .macros = macros }; | |
e0840f11 BP |
1090 | struct expr *e = expr_parse__(&ctx); |
1091 | *errorp = ctx.error; | |
1092 | ovs_assert((ctx.error != NULL) != (e != NULL)); | |
1093 | return e; | |
1094 | } | |
1095 | ||
1096 | /* Like expr_parse(), but the expression is taken from 's'. */ | |
1097 | struct expr * | |
2c5cbb15 RB |
1098 | expr_parse_string(const char *s, const struct shash *symtab, |
1099 | const struct shash *macros, char **errorp) | |
e0840f11 BP |
1100 | { |
1101 | struct lexer lexer; | |
1102 | struct expr *expr; | |
1103 | ||
1104 | lexer_init(&lexer, s); | |
1105 | lexer_get(&lexer); | |
2c5cbb15 | 1106 | expr = expr_parse(&lexer, symtab, macros, errorp); |
8b34ccda | 1107 | if (!*errorp && lexer.token.type != LEX_T_END) { |
e0840f11 BP |
1108 | *errorp = xstrdup("Extra tokens at end of input."); |
1109 | expr_destroy(expr); | |
1110 | expr = NULL; | |
1111 | } | |
1112 | lexer_destroy(&lexer); | |
1113 | ||
1114 | return expr; | |
1115 | } | |
1116 | \f | |
1117 | static struct expr_symbol * | |
1118 | add_symbol(struct shash *symtab, const char *name, int width, | |
1119 | const char *prereqs, enum expr_level level, | |
1120 | bool must_crossproduct) | |
1121 | { | |
1122 | struct expr_symbol *symbol = xzalloc(sizeof *symbol); | |
1123 | symbol->name = xstrdup(name); | |
1124 | symbol->prereqs = prereqs && prereqs[0] ? xstrdup(prereqs) : NULL; | |
1125 | symbol->width = width; | |
1126 | symbol->level = level; | |
1127 | symbol->must_crossproduct = must_crossproduct; | |
1128 | shash_add_assert(symtab, symbol->name, symbol); | |
1129 | return symbol; | |
1130 | } | |
1131 | ||
1132 | /* Adds field 'id' to symbol table 'symtab' under the given 'name'. Whenever | |
1133 | * 'name' is referenced, expression annotation (see expr_annotate()) will | |
1134 | * ensure that 'prereqs' are also true. If 'must_crossproduct' is true, then | |
1135 | * conversion to flows will never attempt to use the field as a conjunctive | |
1136 | * match dimension (see "Crossproducting" in the large comment on struct | |
1137 | * expr_symbol in expr.h for an example). | |
1138 | * | |
1139 | * A given field 'id' must only be used for a single symbol in a symbol table. | |
1140 | * Use subfields to duplicate or subset a field (you can even make a subfield | |
1141 | * include all the bits of the "parent" field if you like). */ | |
1142 | struct expr_symbol * | |
1143 | expr_symtab_add_field(struct shash *symtab, const char *name, | |
1144 | enum mf_field_id id, const char *prereqs, | |
1145 | bool must_crossproduct) | |
1146 | { | |
1147 | const struct mf_field *field = mf_from_id(id); | |
1148 | struct expr_symbol *symbol; | |
1149 | ||
1150 | symbol = add_symbol(symtab, name, field->n_bits, prereqs, | |
1151 | (field->maskable == MFM_FULLY | |
1152 | ? EXPR_L_ORDINAL | |
1153 | : EXPR_L_NOMINAL), | |
1154 | must_crossproduct); | |
1155 | symbol->field = field; | |
1156 | return symbol; | |
1157 | } | |
1158 | ||
1159 | static bool | |
1160 | parse_field_from_string(const char *s, const struct shash *symtab, | |
1161 | struct expr_field *field, char **errorp) | |
1162 | { | |
1163 | struct lexer lexer; | |
1164 | lexer_init(&lexer, s); | |
1165 | lexer_get(&lexer); | |
1166 | ||
1998e474 | 1167 | struct expr_context ctx = { .lexer = &lexer, .symtab = symtab }; |
e0840f11 BP |
1168 | bool ok = parse_field(&ctx, field); |
1169 | if (!ok) { | |
1170 | *errorp = ctx.error; | |
1171 | } else if (lexer.token.type != LEX_T_END) { | |
1172 | *errorp = xstrdup("Extra tokens at end of input."); | |
1173 | ok = false; | |
1174 | } | |
1175 | ||
1176 | lexer_destroy(&lexer); | |
1177 | ||
1178 | return ok; | |
1179 | } | |
1180 | ||
1181 | /* Adds 'name' as a subfield of a larger field in 'symtab'. Whenever | |
1182 | * 'name' is referenced, expression annotation (see expr_annotate()) will | |
1183 | * ensure that 'prereqs' are also true. | |
1184 | * | |
1185 | * 'subfield' must describe the subfield as a string, e.g. "vlan.tci[0..11]" | |
1186 | * for the low 12 bits of a larger field named "vlan.tci". */ | |
1187 | struct expr_symbol * | |
1188 | expr_symtab_add_subfield(struct shash *symtab, const char *name, | |
1189 | const char *prereqs, const char *subfield) | |
1190 | { | |
1191 | struct expr_symbol *symbol; | |
1192 | struct expr_field f; | |
1193 | char *error; | |
1194 | ||
1195 | if (!parse_field_from_string(subfield, symtab, &f, &error)) { | |
1196 | VLOG_WARN("%s: error parsing %s subfield (%s)", subfield, name, error); | |
1197 | free(error); | |
1198 | return NULL; | |
1199 | } | |
1200 | ||
1201 | enum expr_level level = f.symbol->level; | |
1202 | if (level != EXPR_L_ORDINAL) { | |
1203 | VLOG_WARN("can't define %s as subfield of %s field %s", | |
1204 | name, expr_level_to_string(level), f.symbol->name); | |
1205 | } | |
1206 | ||
1207 | symbol = add_symbol(symtab, name, f.n_bits, prereqs, level, false); | |
1208 | symbol->expansion = xstrdup(subfield); | |
1209 | return symbol; | |
1210 | } | |
1211 | ||
1212 | /* Adds a string-valued symbol named 'name' to 'symtab' with the specified | |
1213 | * 'prereqs'. */ | |
1214 | struct expr_symbol * | |
1215 | expr_symtab_add_string(struct shash *symtab, const char *name, | |
f386a8a7 | 1216 | enum mf_field_id id, const char *prereqs) |
e0840f11 | 1217 | { |
f386a8a7 BP |
1218 | const struct mf_field *field = mf_from_id(id); |
1219 | struct expr_symbol *symbol; | |
1220 | ||
1221 | symbol = add_symbol(symtab, name, 0, prereqs, EXPR_L_NOMINAL, false); | |
1222 | symbol->field = field; | |
1223 | return symbol; | |
e0840f11 BP |
1224 | } |
1225 | ||
1226 | static enum expr_level | |
1227 | expr_get_level(const struct expr *expr) | |
1228 | { | |
1229 | const struct expr *sub; | |
1230 | enum expr_level level = EXPR_L_ORDINAL; | |
1231 | ||
1232 | switch (expr->type) { | |
1233 | case EXPR_T_CMP: | |
1234 | return (expr->cmp.symbol->level == EXPR_L_NOMINAL | |
1235 | ? EXPR_L_NOMINAL | |
1236 | : EXPR_L_BOOLEAN); | |
1237 | ||
1238 | case EXPR_T_AND: | |
1239 | case EXPR_T_OR: | |
1240 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1241 | enum expr_level sub_level = expr_get_level(sub); | |
1242 | level = MIN(level, sub_level); | |
1243 | } | |
1244 | return level; | |
1245 | ||
1246 | case EXPR_T_BOOLEAN: | |
1247 | return EXPR_L_BOOLEAN; | |
1248 | ||
1249 | default: | |
1250 | OVS_NOT_REACHED(); | |
1251 | } | |
1252 | } | |
1253 | ||
1254 | static enum expr_level | |
1255 | expr_parse_level(const char *s, const struct shash *symtab, char **errorp) | |
1256 | { | |
2c5cbb15 | 1257 | struct expr *expr = expr_parse_string(s, symtab, NULL, errorp); |
e0840f11 BP |
1258 | enum expr_level level = expr ? expr_get_level(expr) : EXPR_L_NOMINAL; |
1259 | expr_destroy(expr); | |
1260 | return level; | |
1261 | } | |
1262 | ||
1263 | /* Adds a predicate symbol, whose value is the given Boolean 'expression', | |
44283953 | 1264 | * named 'name' to 'symtab'. For example, "ip4 && ip4.proto == 6" might be an |
e0840f11 BP |
1265 | * appropriate predicate named "tcp4". */ |
1266 | struct expr_symbol * | |
1267 | expr_symtab_add_predicate(struct shash *symtab, const char *name, | |
1268 | const char *expansion) | |
1269 | { | |
1270 | struct expr_symbol *symbol; | |
1271 | enum expr_level level; | |
1272 | char *error; | |
1273 | ||
1274 | level = expr_parse_level(expansion, symtab, &error); | |
1275 | if (error) { | |
1276 | VLOG_WARN("%s: error parsing %s expansion (%s)", | |
1277 | expansion, name, error); | |
1278 | free(error); | |
1279 | return NULL; | |
1280 | } | |
1281 | ||
1282 | symbol = add_symbol(symtab, name, 1, NULL, level, false); | |
1283 | symbol->expansion = xstrdup(expansion); | |
1284 | return symbol; | |
1285 | } | |
1286 | ||
1287 | /* Destroys 'symtab' and all of its symbols. */ | |
1288 | void | |
1289 | expr_symtab_destroy(struct shash *symtab) | |
1290 | { | |
1291 | struct shash_node *node, *next; | |
1292 | ||
1293 | SHASH_FOR_EACH_SAFE (node, next, symtab) { | |
1294 | struct expr_symbol *symbol = node->data; | |
1295 | ||
1296 | shash_delete(symtab, node); | |
1297 | free(symbol->name); | |
1298 | free(symbol->prereqs); | |
1299 | free(symbol->expansion); | |
1300 | free(symbol); | |
1301 | } | |
1302 | } | |
1303 | \f | |
1304 | /* Cloning. */ | |
1305 | ||
1306 | static struct expr * | |
1307 | expr_clone_cmp(struct expr *expr) | |
1308 | { | |
1309 | struct expr *new = xmemdup(expr, sizeof *expr); | |
1310 | if (!new->cmp.symbol->width) { | |
1311 | new->cmp.string = xstrdup(new->cmp.string); | |
1312 | } | |
1313 | return new; | |
1314 | } | |
1315 | ||
1316 | static struct expr * | |
1317 | expr_clone_andor(struct expr *expr) | |
1318 | { | |
1319 | struct expr *new = expr_create_andor(expr->type); | |
1320 | struct expr *sub; | |
1321 | ||
1322 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1323 | struct expr *new_sub = expr_clone(sub); | |
417e7e66 | 1324 | ovs_list_push_back(&new->andor, &new_sub->node); |
e0840f11 BP |
1325 | } |
1326 | return new; | |
1327 | } | |
1328 | ||
1329 | /* Returns a clone of 'expr'. This is a "deep copy": neither the returned | |
1330 | * expression nor any of its substructure will be shared with 'expr'. */ | |
1331 | struct expr * | |
1332 | expr_clone(struct expr *expr) | |
1333 | { | |
1334 | switch (expr->type) { | |
1335 | case EXPR_T_CMP: | |
1336 | return expr_clone_cmp(expr); | |
1337 | ||
1338 | case EXPR_T_AND: | |
1339 | case EXPR_T_OR: | |
1340 | return expr_clone_andor(expr); | |
1341 | ||
1342 | case EXPR_T_BOOLEAN: | |
1343 | return expr_create_boolean(expr->boolean); | |
1344 | } | |
1345 | OVS_NOT_REACHED(); | |
1346 | } | |
1347 | \f | |
1348 | /* Destroys 'expr' and all of the sub-expressions it references. */ | |
1349 | void | |
1350 | expr_destroy(struct expr *expr) | |
1351 | { | |
1352 | if (!expr) { | |
1353 | return; | |
1354 | } | |
1355 | ||
1356 | struct expr *sub, *next; | |
1357 | ||
1358 | switch (expr->type) { | |
1359 | case EXPR_T_CMP: | |
1360 | if (!expr->cmp.symbol->width) { | |
1361 | free(expr->cmp.string); | |
1362 | } | |
1363 | break; | |
1364 | ||
1365 | case EXPR_T_AND: | |
1366 | case EXPR_T_OR: | |
1367 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1368 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1369 | expr_destroy(sub); |
1370 | } | |
1371 | break; | |
1372 | ||
1373 | case EXPR_T_BOOLEAN: | |
1374 | break; | |
1375 | } | |
1376 | free(expr); | |
1377 | } | |
1378 | \f | |
1379 | /* Annotation. */ | |
1380 | ||
1381 | /* An element in a linked list of symbols. | |
1382 | * | |
1383 | * Used to detect when a symbol is being expanded recursively, to allow | |
1384 | * flagging an error. */ | |
1385 | struct annotation_nesting { | |
1386 | struct ovs_list node; | |
1387 | const struct expr_symbol *symbol; | |
1388 | }; | |
1389 | ||
1390 | struct expr *expr_annotate__(struct expr *, const struct shash *symtab, | |
1391 | struct ovs_list *nesting, char **errorp); | |
1392 | ||
1393 | static struct expr * | |
1394 | parse_and_annotate(const char *s, const struct shash *symtab, | |
1395 | struct ovs_list *nesting, char **errorp) | |
1396 | { | |
1397 | char *error; | |
1398 | struct expr *expr; | |
1399 | ||
2c5cbb15 | 1400 | expr = expr_parse_string(s, symtab, NULL, &error); |
e0840f11 BP |
1401 | if (expr) { |
1402 | expr = expr_annotate__(expr, symtab, nesting, &error); | |
1403 | } | |
3b7cb7e1 BP |
1404 | if (expr) { |
1405 | *errorp = NULL; | |
1406 | } else { | |
e0840f11 BP |
1407 | *errorp = xasprintf("Error parsing expression `%s' encountered as " |
1408 | "prerequisite or predicate of initial expression: " | |
1409 | "%s", s, error); | |
1410 | free(error); | |
1411 | } | |
1412 | return expr; | |
1413 | } | |
1414 | ||
1415 | static struct expr * | |
1416 | expr_annotate_cmp(struct expr *expr, const struct shash *symtab, | |
1417 | struct ovs_list *nesting, char **errorp) | |
1418 | { | |
1419 | const struct expr_symbol *symbol = expr->cmp.symbol; | |
1420 | const struct annotation_nesting *iter; | |
1421 | LIST_FOR_EACH (iter, node, nesting) { | |
1422 | if (iter->symbol == symbol) { | |
1423 | *errorp = xasprintf("Recursive expansion of symbol `%s'.", | |
1424 | symbol->name); | |
1425 | expr_destroy(expr); | |
1426 | return NULL; | |
1427 | } | |
1428 | } | |
1429 | ||
1430 | struct annotation_nesting an; | |
1431 | an.symbol = symbol; | |
417e7e66 | 1432 | ovs_list_push_back(nesting, &an.node); |
e0840f11 BP |
1433 | |
1434 | struct expr *prereqs = NULL; | |
1435 | if (symbol->prereqs) { | |
1436 | prereqs = parse_and_annotate(symbol->prereqs, symtab, nesting, errorp); | |
1437 | if (!prereqs) { | |
1438 | goto error; | |
1439 | } | |
1440 | } | |
1441 | ||
1442 | if (symbol->expansion) { | |
1443 | if (symbol->level == EXPR_L_ORDINAL) { | |
1444 | struct expr_field field; | |
1445 | ||
1446 | if (!parse_field_from_string(symbol->expansion, symtab, | |
1447 | &field, errorp)) { | |
1448 | goto error; | |
1449 | } | |
1450 | ||
1451 | expr->cmp.symbol = field.symbol; | |
1452 | mf_subvalue_shift(&expr->cmp.value, field.ofs); | |
1453 | mf_subvalue_shift(&expr->cmp.mask, field.ofs); | |
1454 | } else { | |
1455 | struct expr *expansion; | |
1456 | ||
1457 | expansion = parse_and_annotate(symbol->expansion, symtab, | |
1458 | nesting, errorp); | |
1459 | if (!expansion) { | |
1460 | goto error; | |
1461 | } | |
1462 | ||
1463 | bool positive = (expr->cmp.value.integer & htonll(1)) != 0; | |
1464 | positive ^= expr->cmp.relop == EXPR_R_NE; | |
1465 | if (!positive) { | |
1466 | expr_not(expansion); | |
1467 | } | |
1468 | ||
1469 | expr_destroy(expr); | |
1470 | expr = expansion; | |
1471 | } | |
1472 | } | |
1473 | ||
417e7e66 | 1474 | ovs_list_remove(&an.node); |
e0840f11 BP |
1475 | return prereqs ? expr_combine(EXPR_T_AND, expr, prereqs) : expr; |
1476 | ||
1477 | error: | |
1478 | expr_destroy(expr); | |
1479 | expr_destroy(prereqs); | |
417e7e66 | 1480 | ovs_list_remove(&an.node); |
e0840f11 BP |
1481 | return NULL; |
1482 | } | |
1483 | ||
1484 | struct expr * | |
1485 | expr_annotate__(struct expr *expr, const struct shash *symtab, | |
1486 | struct ovs_list *nesting, char **errorp) | |
1487 | { | |
1488 | switch (expr->type) { | |
1489 | case EXPR_T_CMP: | |
1490 | return expr_annotate_cmp(expr, symtab, nesting, errorp); | |
1491 | ||
1492 | case EXPR_T_AND: | |
1493 | case EXPR_T_OR: { | |
1494 | struct expr *sub, *next; | |
1495 | ||
1496 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1497 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1498 | struct expr *new_sub = expr_annotate__(sub, symtab, |
1499 | nesting, errorp); | |
1500 | if (!new_sub) { | |
1501 | expr_destroy(expr); | |
1502 | return NULL; | |
1503 | } | |
1504 | expr_insert_andor(expr, next, new_sub); | |
1505 | } | |
1506 | *errorp = NULL; | |
1507 | return expr; | |
1508 | } | |
1509 | ||
1510 | case EXPR_T_BOOLEAN: | |
1511 | *errorp = NULL; | |
1512 | return expr; | |
1513 | ||
1514 | default: | |
1515 | OVS_NOT_REACHED(); | |
1516 | } | |
1517 | } | |
1518 | ||
1519 | /* "Annotates" 'expr', which does the following: | |
1520 | * | |
1521 | * - Applies prerequisites, by locating each comparison operator whose | |
1522 | * field has a prerequisite and adding a logical AND against those | |
1523 | * prerequisites. | |
1524 | * | |
1525 | * - Expands references to subfield symbols, by replacing them by | |
1526 | * references to their underlying field symbols (suitably shifted). | |
1527 | * | |
1528 | * - Expands references to predicate symbols, by replacing them by the | |
1529 | * expressions that they expand to. | |
1530 | * | |
1385d7b7 JP |
1531 | * In each case, annotation occurs recursively as necessary. |
1532 | * | |
1533 | * On failure, returns NULL and sets '*errorp' to an explanatory error | |
1534 | * message, which the caller must free. */ | |
e0840f11 BP |
1535 | struct expr * |
1536 | expr_annotate(struct expr *expr, const struct shash *symtab, char **errorp) | |
1537 | { | |
1538 | struct ovs_list nesting = OVS_LIST_INITIALIZER(&nesting); | |
1539 | return expr_annotate__(expr, symtab, &nesting, errorp); | |
1540 | } | |
1541 | \f | |
1542 | static struct expr * | |
1543 | expr_simplify_ne(struct expr *expr) | |
1544 | { | |
1545 | struct expr *new = NULL; | |
1546 | const union mf_subvalue *value = &expr->cmp.value; | |
1547 | const union mf_subvalue *mask = &expr->cmp.mask; | |
1548 | int w = expr->cmp.symbol->width; | |
1549 | int i; | |
1550 | ||
1551 | for (i = 0; (i = bitwise_scan(mask, sizeof *mask, true, i, w)) < w; i++) { | |
1552 | struct expr *e; | |
1553 | ||
1554 | e = xzalloc(sizeof *e); | |
1555 | e->type = EXPR_T_CMP; | |
1556 | e->cmp.symbol = expr->cmp.symbol; | |
1557 | e->cmp.relop = EXPR_R_EQ; | |
1558 | bitwise_put_bit(&e->cmp.value, sizeof e->cmp.value, i, | |
1559 | !bitwise_get_bit(value, sizeof *value, i)); | |
1560 | bitwise_put1(&e->cmp.mask, sizeof e->cmp.mask, i); | |
1561 | ||
1562 | new = expr_combine(EXPR_T_OR, new, e); | |
1563 | } | |
1564 | ovs_assert(new); | |
1565 | ||
1566 | expr_destroy(expr); | |
1567 | ||
1568 | return new; | |
1569 | } | |
1570 | ||
1571 | static struct expr * | |
1572 | expr_simplify_relational(struct expr *expr) | |
1573 | { | |
1574 | const union mf_subvalue *value = &expr->cmp.value; | |
1575 | int start, n_bits, end; | |
1576 | ||
1577 | find_bitwise_range(&expr->cmp.mask, expr->cmp.symbol->width, | |
1578 | &start, &n_bits); | |
1579 | ovs_assert(n_bits > 0); | |
1580 | end = start + n_bits; | |
1581 | ||
1582 | struct expr *new; | |
1583 | if (expr->cmp.relop == EXPR_R_LE || expr->cmp.relop == EXPR_R_GE) { | |
1584 | new = xmemdup(expr, sizeof *expr); | |
1585 | new->cmp.relop = EXPR_R_EQ; | |
1586 | } else { | |
1587 | new = NULL; | |
1588 | } | |
1589 | ||
1590 | bool b = expr->cmp.relop == EXPR_R_LT || expr->cmp.relop == EXPR_R_LE; | |
1591 | for (int z = bitwise_scan(value, sizeof *value, b, start, end); | |
1592 | z < end; | |
1593 | z = bitwise_scan(value, sizeof *value, b, z + 1, end)) { | |
1594 | struct expr *e; | |
1595 | ||
1596 | e = xmemdup(expr, sizeof *expr); | |
1597 | e->cmp.relop = EXPR_R_EQ; | |
1598 | bitwise_toggle_bit(&e->cmp.value, sizeof e->cmp.value, z); | |
1599 | bitwise_zero(&e->cmp.value, sizeof e->cmp.value, start, z - start); | |
1600 | bitwise_zero(&e->cmp.mask, sizeof e->cmp.mask, start, z - start); | |
1601 | new = expr_combine(EXPR_T_OR, new, e); | |
1602 | } | |
1603 | expr_destroy(expr); | |
1604 | return new ? new : expr_create_boolean(false); | |
1605 | } | |
1606 | ||
1607 | /* Takes ownership of 'expr' and returns an equivalent expression whose | |
1608 | * EXPR_T_CMP nodes use only tests for equality (EXPR_R_EQ). */ | |
1609 | struct expr * | |
1610 | expr_simplify(struct expr *expr) | |
1611 | { | |
1612 | struct expr *sub, *next; | |
1613 | ||
1614 | switch (expr->type) { | |
1615 | case EXPR_T_CMP: | |
1616 | return (expr->cmp.relop == EXPR_R_EQ || !expr->cmp.symbol->width ? expr | |
1617 | : expr->cmp.relop == EXPR_R_NE ? expr_simplify_ne(expr) | |
1618 | : expr_simplify_relational(expr)); | |
1619 | ||
1620 | case EXPR_T_AND: | |
1621 | case EXPR_T_OR: | |
1622 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1623 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1624 | expr_insert_andor(expr, next, expr_simplify(sub)); |
1625 | } | |
1626 | return expr_fix(expr); | |
1627 | ||
1628 | case EXPR_T_BOOLEAN: | |
1629 | return expr; | |
1630 | } | |
1631 | OVS_NOT_REACHED(); | |
1632 | } | |
1633 | \f | |
1634 | static const struct expr_symbol * | |
1635 | expr_is_cmp(const struct expr *expr) | |
1636 | { | |
1637 | switch (expr->type) { | |
1638 | case EXPR_T_CMP: | |
1639 | return expr->cmp.symbol; | |
1640 | ||
1641 | case EXPR_T_AND: | |
1642 | case EXPR_T_OR: { | |
1643 | const struct expr_symbol *prev = NULL; | |
1644 | struct expr *sub; | |
1645 | ||
1646 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1647 | const struct expr_symbol *symbol = expr_is_cmp(sub); | |
1648 | if (!symbol || (prev && symbol != prev)) { | |
1649 | return NULL; | |
1650 | } | |
1651 | prev = symbol; | |
1652 | } | |
1653 | return prev; | |
1654 | } | |
1655 | ||
1656 | case EXPR_T_BOOLEAN: | |
1657 | return NULL; | |
1658 | ||
1659 | default: | |
1660 | OVS_NOT_REACHED(); | |
1661 | } | |
1662 | } | |
1663 | ||
1664 | struct expr_sort { | |
1665 | struct expr *expr; | |
1666 | const struct expr_symbol *relop; | |
1667 | enum expr_type type; | |
1668 | }; | |
1669 | ||
1670 | static int | |
1671 | compare_expr_sort(const void *a_, const void *b_) | |
1672 | { | |
1673 | const struct expr_sort *a = a_; | |
1674 | const struct expr_sort *b = b_; | |
1675 | ||
1676 | if (a->type != b->type) { | |
1677 | return a->type < b->type ? -1 : 1; | |
1678 | } else if (a->relop) { | |
1679 | int cmp = strcmp(a->relop->name, b->relop->name); | |
1680 | if (cmp) { | |
1681 | return cmp; | |
1682 | } | |
1683 | ||
1684 | enum expr_type a_type = a->expr->type; | |
1685 | enum expr_type b_type = a->expr->type; | |
1686 | return a_type < b_type ? -1 : a_type > b_type; | |
1687 | } else if (a->type == EXPR_T_AND || a->type == EXPR_T_OR) { | |
417e7e66 BW |
1688 | size_t a_len = ovs_list_size(&a->expr->andor); |
1689 | size_t b_len = ovs_list_size(&b->expr->andor); | |
e0840f11 BP |
1690 | return a_len < b_len ? -1 : a_len > b_len; |
1691 | } else { | |
1692 | return 0; | |
1693 | } | |
1694 | } | |
1695 | ||
1696 | static struct expr *crush_cmps(struct expr *, const struct expr_symbol *); | |
1697 | ||
9d4aecca BP |
1698 | static bool |
1699 | disjunction_matches_string(const struct expr *or, const char *s) | |
1700 | { | |
1701 | const struct expr *sub; | |
1702 | ||
1703 | LIST_FOR_EACH (sub, node, &or->andor) { | |
1704 | if (!strcmp(sub->cmp.string, s)) { | |
1705 | return true; | |
1706 | } | |
1707 | } | |
1708 | ||
1709 | return false; | |
1710 | } | |
1711 | ||
1712 | /* Implementation of crush_cmps() for expr->type == EXPR_T_AND and a | |
1713 | * string-typed 'symbol'. */ | |
e0840f11 | 1714 | static struct expr * |
9d4aecca BP |
1715 | crush_and_string(struct expr *expr, const struct expr_symbol *symbol) |
1716 | { | |
417e7e66 | 1717 | ovs_assert(!ovs_list_is_short(&expr->andor)); |
9d4aecca BP |
1718 | |
1719 | struct expr *singleton = NULL; | |
1720 | ||
1721 | /* First crush each subexpression into either a single EXPR_T_CMP or an | |
1722 | * EXPR_T_OR with EXPR_T_CMP subexpressions. */ | |
1723 | struct expr *sub, *next = NULL; | |
1724 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1725 | ovs_list_remove(&sub->node); |
9d4aecca BP |
1726 | struct expr *new = crush_cmps(sub, symbol); |
1727 | switch (new->type) { | |
1728 | case EXPR_T_CMP: | |
1729 | if (!singleton) { | |
417e7e66 | 1730 | ovs_list_insert(&next->node, &new->node); |
9d4aecca BP |
1731 | singleton = new; |
1732 | } else { | |
1733 | bool match = !strcmp(new->cmp.string, singleton->cmp.string); | |
1734 | expr_destroy(new); | |
1735 | if (!match) { | |
1736 | expr_destroy(expr); | |
1737 | return expr_create_boolean(false); | |
1738 | } | |
1739 | } | |
1740 | break; | |
1741 | case EXPR_T_AND: | |
1742 | OVS_NOT_REACHED(); | |
1743 | case EXPR_T_OR: | |
417e7e66 | 1744 | ovs_list_insert(&next->node, &new->node); |
9d4aecca BP |
1745 | break; |
1746 | case EXPR_T_BOOLEAN: | |
1747 | if (!new->boolean) { | |
1748 | expr_destroy(expr); | |
1749 | return new; | |
1750 | } | |
1751 | free(new); | |
1752 | break; | |
1753 | } | |
1754 | } | |
1755 | ||
1756 | /* If we have a singleton, then the result is either the singleton itself | |
1757 | * (if the ORs allow the singleton) or false. */ | |
1758 | if (singleton) { | |
1759 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
1760 | if (sub->type == EXPR_T_OR | |
1761 | && !disjunction_matches_string(sub, singleton->cmp.string)) { | |
1762 | expr_destroy(expr); | |
1763 | return expr_create_boolean(false); | |
1764 | } | |
1765 | } | |
417e7e66 | 1766 | ovs_list_remove(&singleton->node); |
9d4aecca BP |
1767 | expr_destroy(expr); |
1768 | return singleton; | |
1769 | } | |
1770 | ||
1771 | /* Otherwise the result is the intersection of all of the ORs. */ | |
1772 | struct sset result = SSET_INITIALIZER(&result); | |
1773 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
1774 | struct sset strings = SSET_INITIALIZER(&strings); | |
1775 | const struct expr *s; | |
1776 | LIST_FOR_EACH (s, node, &sub->andor) { | |
1777 | sset_add(&strings, s->cmp.string); | |
1778 | } | |
1779 | if (sset_is_empty(&result)) { | |
1780 | sset_swap(&result, &strings); | |
1781 | } else { | |
1782 | sset_intersect(&result, &strings); | |
1783 | } | |
1784 | sset_destroy(&strings); | |
1785 | ||
1786 | if (sset_is_empty(&result)) { | |
1787 | expr_destroy(expr); | |
1788 | sset_destroy(&result); | |
1789 | return expr_create_boolean(false); | |
1790 | } | |
1791 | } | |
1792 | ||
1793 | expr_destroy(expr); | |
1794 | expr = expr_create_andor(EXPR_T_OR); | |
1795 | ||
1796 | const char *string; | |
1797 | SSET_FOR_EACH (string, &result) { | |
1798 | sub = xmalloc(sizeof *sub); | |
1799 | sub->type = EXPR_T_CMP; | |
1800 | sub->cmp.symbol = symbol; | |
1801 | sub->cmp.string = xstrdup(string); | |
417e7e66 | 1802 | ovs_list_push_back(&expr->andor, &sub->node); |
9d4aecca | 1803 | } |
1cad4a75 | 1804 | sset_destroy(&result); |
9d4aecca BP |
1805 | return expr_fix(expr); |
1806 | } | |
1807 | ||
1808 | /* Implementation of crush_cmps() for expr->type == EXPR_T_AND and a | |
1809 | * numeric-typed 'symbol'. */ | |
1810 | static struct expr * | |
1811 | crush_and_numeric(struct expr *expr, const struct expr_symbol *symbol) | |
e0840f11 | 1812 | { |
417e7e66 | 1813 | ovs_assert(!ovs_list_is_short(&expr->andor)); |
e0840f11 BP |
1814 | |
1815 | union mf_subvalue value, mask; | |
1816 | memset(&value, 0, sizeof value); | |
1817 | memset(&mask, 0, sizeof mask); | |
1818 | ||
1819 | struct expr *sub, *next = NULL; | |
1820 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
417e7e66 | 1821 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1822 | struct expr *new = crush_cmps(sub, symbol); |
1823 | switch (new->type) { | |
1824 | case EXPR_T_CMP: | |
1825 | if (!mf_subvalue_intersect(&value, &mask, | |
1826 | &new->cmp.value, &new->cmp.mask, | |
1827 | &value, &mask)) { | |
1828 | expr_destroy(new); | |
1829 | expr_destroy(expr); | |
1830 | return expr_create_boolean(false); | |
1831 | } | |
1832 | expr_destroy(new); | |
1833 | break; | |
1834 | case EXPR_T_AND: | |
1835 | OVS_NOT_REACHED(); | |
1836 | case EXPR_T_OR: | |
417e7e66 | 1837 | ovs_list_insert(&next->node, &new->node); |
e0840f11 BP |
1838 | break; |
1839 | case EXPR_T_BOOLEAN: | |
1840 | if (!new->boolean) { | |
1841 | expr_destroy(expr); | |
1842 | return new; | |
1843 | } | |
45c4387b | 1844 | expr_destroy(new); |
e0840f11 BP |
1845 | break; |
1846 | } | |
1847 | } | |
417e7e66 | 1848 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
1849 | if (is_all_zeros(&mask, sizeof mask)) { |
1850 | expr_destroy(expr); | |
1851 | return expr_create_boolean(true); | |
1852 | } else { | |
1853 | struct expr *cmp; | |
1854 | cmp = xmalloc(sizeof *cmp); | |
1855 | cmp->type = EXPR_T_CMP; | |
1856 | cmp->cmp.symbol = symbol; | |
1857 | cmp->cmp.relop = EXPR_R_EQ; | |
1858 | cmp->cmp.value = value; | |
1859 | cmp->cmp.mask = mask; | |
1860 | expr_destroy(expr); | |
1861 | return cmp; | |
1862 | } | |
417e7e66 | 1863 | } else if (ovs_list_is_short(&expr->andor)) { |
e0840f11 BP |
1864 | /* Transform "a && (b || c || d)" into "ab || ac || ad" where "ab" is |
1865 | * computed as "a && b", etc. */ | |
417e7e66 | 1866 | struct expr *disjuncts = expr_from_node(ovs_list_pop_front(&expr->andor)); |
e0840f11 BP |
1867 | struct expr *or; |
1868 | ||
1869 | or = xmalloc(sizeof *or); | |
1870 | or->type = EXPR_T_OR; | |
417e7e66 | 1871 | ovs_list_init(&or->andor); |
e0840f11 BP |
1872 | |
1873 | ovs_assert(disjuncts->type == EXPR_T_OR); | |
1874 | LIST_FOR_EACH_SAFE (sub, next, node, &disjuncts->andor) { | |
1875 | ovs_assert(sub->type == EXPR_T_CMP); | |
417e7e66 | 1876 | ovs_list_remove(&sub->node); |
e0840f11 BP |
1877 | if (mf_subvalue_intersect(&value, &mask, |
1878 | &sub->cmp.value, &sub->cmp.mask, | |
1879 | &sub->cmp.value, &sub->cmp.mask)) { | |
417e7e66 | 1880 | ovs_list_push_back(&or->andor, &sub->node); |
e0840f11 | 1881 | } else { |
45c4387b | 1882 | expr_destroy(sub); |
e0840f11 BP |
1883 | } |
1884 | } | |
1885 | free(disjuncts); | |
1886 | free(expr); | |
417e7e66 | 1887 | if (ovs_list_is_empty(&or->andor)) { |
e0840f11 BP |
1888 | free(or); |
1889 | return expr_create_boolean(false); | |
417e7e66 BW |
1890 | } else if (ovs_list_is_short(&or->andor)) { |
1891 | struct expr *cmp = expr_from_node(ovs_list_pop_front(&or->andor)); | |
e0840f11 BP |
1892 | free(or); |
1893 | return cmp; | |
1894 | } else { | |
1895 | return or; | |
1896 | } | |
1897 | } else { | |
1898 | /* Transform "x && (a0 || a1) && (b0 || b1) && ..." into | |
1899 | * "(xa0b0 || xa0b1 || xa1b0 || xa1b1) && ...". */ | |
417e7e66 BW |
1900 | struct expr *as = expr_from_node(ovs_list_pop_front(&expr->andor)); |
1901 | struct expr *bs = expr_from_node(ovs_list_pop_front(&expr->andor)); | |
e0840f11 BP |
1902 | struct expr *new = NULL; |
1903 | struct expr *or; | |
1904 | ||
1905 | or = xmalloc(sizeof *or); | |
1906 | or->type = EXPR_T_OR; | |
417e7e66 | 1907 | ovs_list_init(&or->andor); |
e0840f11 BP |
1908 | |
1909 | struct expr *a; | |
1910 | LIST_FOR_EACH (a, node, &as->andor) { | |
1911 | union mf_subvalue a_value, a_mask; | |
1912 | ||
1913 | ovs_assert(a->type == EXPR_T_CMP); | |
1914 | if (!mf_subvalue_intersect(&value, &mask, | |
1915 | &a->cmp.value, &a->cmp.mask, | |
1916 | &a_value, &a_mask)) { | |
1917 | continue; | |
1918 | } | |
1919 | ||
1920 | struct expr *b; | |
1921 | LIST_FOR_EACH (b, node, &bs->andor) { | |
1922 | ovs_assert(b->type == EXPR_T_CMP); | |
1923 | if (!new) { | |
1924 | new = xmalloc(sizeof *new); | |
1925 | new->type = EXPR_T_CMP; | |
1926 | new->cmp.symbol = symbol; | |
1927 | new->cmp.relop = EXPR_R_EQ; | |
1928 | } | |
1929 | if (mf_subvalue_intersect(&a_value, &a_mask, | |
1930 | &b->cmp.value, &b->cmp.mask, | |
1931 | &new->cmp.value, &new->cmp.mask)) { | |
417e7e66 | 1932 | ovs_list_push_back(&or->andor, &new->node); |
e0840f11 BP |
1933 | new = NULL; |
1934 | } | |
1935 | } | |
1936 | } | |
1937 | expr_destroy(as); | |
1938 | expr_destroy(bs); | |
1939 | free(new); | |
1940 | ||
417e7e66 | 1941 | if (ovs_list_is_empty(&or->andor)) { |
e0840f11 BP |
1942 | expr_destroy(expr); |
1943 | free(or); | |
1944 | return expr_create_boolean(false); | |
417e7e66 BW |
1945 | } else if (ovs_list_is_short(&or->andor)) { |
1946 | struct expr *cmp = expr_from_node(ovs_list_pop_front(&or->andor)); | |
e0840f11 | 1947 | free(or); |
417e7e66 | 1948 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
1949 | expr_destroy(expr); |
1950 | return crush_cmps(cmp, symbol); | |
1951 | } else { | |
1952 | return crush_cmps(expr_combine(EXPR_T_AND, cmp, expr), symbol); | |
1953 | } | |
417e7e66 | 1954 | } else if (!ovs_list_is_empty(&expr->andor)) { |
e0840f11 | 1955 | struct expr *e = expr_combine(EXPR_T_AND, or, expr); |
417e7e66 | 1956 | ovs_assert(!ovs_list_is_short(&e->andor)); |
e0840f11 BP |
1957 | return crush_cmps(e, symbol); |
1958 | } else { | |
1959 | expr_destroy(expr); | |
1960 | return crush_cmps(or, symbol); | |
1961 | } | |
1962 | } | |
1963 | } | |
1964 | ||
1965 | static int | |
9d4aecca BP |
1966 | compare_cmps_3way(const struct expr *a, const struct expr *b) |
1967 | { | |
1968 | ovs_assert(a->cmp.symbol == b->cmp.symbol); | |
1969 | if (!a->cmp.symbol->width) { | |
1970 | return strcmp(a->cmp.string, b->cmp.string); | |
1971 | } else { | |
1972 | int d = memcmp(&a->cmp.value, &b->cmp.value, sizeof a->cmp.value); | |
1973 | if (!d) { | |
1974 | d = memcmp(&a->cmp.mask, &b->cmp.mask, sizeof a->cmp.mask); | |
1975 | } | |
1976 | return d; | |
1977 | } | |
1978 | } | |
1979 | ||
1980 | static int | |
1981 | compare_cmps_cb(const void *a_, const void *b_) | |
e0840f11 BP |
1982 | { |
1983 | const struct expr *const *ap = a_; | |
1984 | const struct expr *const *bp = b_; | |
1985 | const struct expr *a = *ap; | |
1986 | const struct expr *b = *bp; | |
9d4aecca | 1987 | return compare_cmps_3way(a, b); |
e0840f11 BP |
1988 | } |
1989 | ||
fd477c6e | 1990 | /* Implementation of crush_cmps() for expr->type == EXPR_T_OR. */ |
e0840f11 BP |
1991 | static struct expr * |
1992 | crush_or(struct expr *expr, const struct expr_symbol *symbol) | |
1993 | { | |
1994 | struct expr *sub, *next = NULL; | |
1995 | ||
1996 | /* First, crush all the subexpressions. That might eliminate the | |
fd477c6e BP |
1997 | * OR-expression entirely; if so, return the result. Otherwise, 'expr' |
1998 | * is now a disjunction of cmps over the same symbol. */ | |
e0840f11 | 1999 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { |
417e7e66 | 2000 | ovs_list_remove(&sub->node); |
e0840f11 BP |
2001 | expr_insert_andor(expr, next, crush_cmps(sub, symbol)); |
2002 | } | |
2003 | expr = expr_fix(expr); | |
2004 | if (expr->type != EXPR_T_OR) { | |
2005 | return expr; | |
2006 | } | |
2007 | ||
fd477c6e | 2008 | /* Sort subexpressions by value and mask, to bring together duplicates. */ |
417e7e66 | 2009 | size_t n = ovs_list_size(&expr->andor); |
e0840f11 BP |
2010 | struct expr **subs = xmalloc(n * sizeof *subs); |
2011 | ||
2012 | size_t i = 0; | |
2013 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2014 | subs[i++] = sub; | |
2015 | } | |
2016 | ovs_assert(i == n); | |
2017 | ||
9d4aecca | 2018 | qsort(subs, n, sizeof *subs, compare_cmps_cb); |
e0840f11 | 2019 | |
9d4aecca | 2020 | /* Eliminate duplicates. */ |
417e7e66 BW |
2021 | ovs_list_init(&expr->andor); |
2022 | ovs_list_push_back(&expr->andor, &subs[0]->node); | |
e0840f11 | 2023 | for (i = 1; i < n; i++) { |
417e7e66 | 2024 | struct expr *a = expr_from_node(ovs_list_back(&expr->andor)); |
e0840f11 | 2025 | struct expr *b = subs[i]; |
9d4aecca | 2026 | if (compare_cmps_3way(a, b)) { |
417e7e66 | 2027 | ovs_list_push_back(&expr->andor, &b->node); |
e0840f11 | 2028 | } else { |
45c4387b | 2029 | expr_destroy(b); |
e0840f11 BP |
2030 | } |
2031 | } | |
2032 | free(subs); | |
2033 | return expr_fix(expr); | |
2034 | } | |
2035 | ||
fd477c6e BP |
2036 | /* Takes ownership of 'expr', which must be a cmp in the sense determined by |
2037 | * 'expr_is_cmp(expr)', where 'symbol' is the symbol returned by that function. | |
2038 | * Returns an equivalent expression owned by the caller that is a single | |
2039 | * EXPR_T_CMP or a disjunction of them or a EXPR_T_BOOLEAN. */ | |
e0840f11 BP |
2040 | static struct expr * |
2041 | crush_cmps(struct expr *expr, const struct expr_symbol *symbol) | |
2042 | { | |
2043 | switch (expr->type) { | |
2044 | case EXPR_T_OR: | |
2045 | return crush_or(expr, symbol); | |
2046 | ||
2047 | case EXPR_T_AND: | |
9d4aecca BP |
2048 | return (symbol->width |
2049 | ? crush_and_numeric(expr, symbol) | |
2050 | : crush_and_string(expr, symbol)); | |
e0840f11 BP |
2051 | |
2052 | case EXPR_T_CMP: | |
2053 | return expr; | |
2054 | ||
2055 | case EXPR_T_BOOLEAN: | |
2056 | return expr; | |
2057 | ||
2058 | default: | |
2059 | OVS_NOT_REACHED(); | |
2060 | } | |
2061 | } | |
2062 | ||
2063 | static struct expr * | |
2064 | expr_sort(struct expr *expr) | |
2065 | { | |
417e7e66 | 2066 | size_t n = ovs_list_size(&expr->andor); |
e0840f11 BP |
2067 | struct expr_sort *subs = xmalloc(n * sizeof *subs); |
2068 | struct expr *sub; | |
2069 | size_t i; | |
2070 | ||
2071 | i = 0; | |
2072 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2073 | subs[i].expr = sub; | |
2074 | subs[i].relop = expr_is_cmp(sub); | |
2075 | subs[i].type = subs[i].relop ? EXPR_T_CMP : sub->type; | |
2076 | i++; | |
2077 | } | |
2078 | ovs_assert(i == n); | |
2079 | ||
2080 | qsort(subs, n, sizeof *subs, compare_expr_sort); | |
2081 | ||
417e7e66 | 2082 | ovs_list_init(&expr->andor); |
e0840f11 BP |
2083 | for (int i = 0; i < n; ) { |
2084 | if (subs[i].relop) { | |
2085 | int j; | |
2086 | for (j = i + 1; j < n; j++) { | |
2087 | if (subs[i].relop != subs[j].relop) { | |
2088 | break; | |
2089 | } | |
2090 | } | |
2091 | ||
2092 | struct expr *crushed; | |
2093 | if (j == i + 1) { | |
2094 | crushed = crush_cmps(subs[i].expr, subs[i].relop); | |
2095 | } else { | |
2096 | struct expr *combined = subs[i].expr; | |
2097 | for (int k = i + 1; k < j; k++) { | |
2098 | combined = expr_combine(EXPR_T_AND, combined, | |
2099 | subs[k].expr); | |
2100 | } | |
417e7e66 | 2101 | ovs_assert(!ovs_list_is_short(&combined->andor)); |
e0840f11 BP |
2102 | crushed = crush_cmps(combined, subs[i].relop); |
2103 | } | |
2104 | if (crushed->type == EXPR_T_BOOLEAN) { | |
2105 | if (!crushed->boolean) { | |
2106 | for (int k = j; k < n; k++) { | |
2107 | expr_destroy(subs[k].expr); | |
2108 | } | |
2109 | expr_destroy(expr); | |
2110 | expr = crushed; | |
2111 | break; | |
2112 | } else { | |
2113 | free(crushed); | |
2114 | } | |
2115 | } else { | |
2116 | expr = expr_combine(EXPR_T_AND, expr, crushed); | |
2117 | } | |
2118 | i = j; | |
2119 | } else { | |
2120 | expr = expr_combine(EXPR_T_AND, expr, subs[i++].expr); | |
2121 | } | |
2122 | } | |
2123 | free(subs); | |
2124 | ||
2125 | return expr; | |
2126 | } | |
2127 | ||
2128 | static struct expr *expr_normalize_or(struct expr *expr); | |
2129 | ||
2130 | /* Returns 'expr', which is an AND, reduced to OR(AND(clause)) where | |
2131 | * a clause is a cmp or a disjunction of cmps on a single field. */ | |
2132 | static struct expr * | |
2133 | expr_normalize_and(struct expr *expr) | |
2134 | { | |
2135 | ovs_assert(expr->type == EXPR_T_AND); | |
2136 | ||
2137 | expr = expr_sort(expr); | |
2138 | if (expr->type != EXPR_T_AND) { | |
2139 | ovs_assert(expr->type == EXPR_T_BOOLEAN); | |
2140 | return expr; | |
2141 | } | |
2142 | ||
2143 | struct expr *a, *b; | |
2144 | LIST_FOR_EACH_SAFE (a, b, node, &expr->andor) { | |
2145 | if (&b->node == &expr->andor | |
9d4aecca BP |
2146 | || a->type != EXPR_T_CMP || b->type != EXPR_T_CMP |
2147 | || a->cmp.symbol != b->cmp.symbol) { | |
e0840f11 | 2148 | continue; |
9d4aecca BP |
2149 | } else if (a->cmp.symbol->width |
2150 | ? mf_subvalue_intersect(&a->cmp.value, &a->cmp.mask, | |
2151 | &b->cmp.value, &b->cmp.mask, | |
2152 | &b->cmp.value, &b->cmp.mask) | |
2153 | : !strcmp(a->cmp.string, b->cmp.string)) { | |
417e7e66 | 2154 | ovs_list_remove(&a->node); |
e0840f11 BP |
2155 | expr_destroy(a); |
2156 | } else { | |
2157 | expr_destroy(expr); | |
2158 | return expr_create_boolean(false); | |
2159 | } | |
2160 | } | |
417e7e66 BW |
2161 | if (ovs_list_is_short(&expr->andor)) { |
2162 | struct expr *sub = expr_from_node(ovs_list_front(&expr->andor)); | |
e0840f11 BP |
2163 | free(expr); |
2164 | return sub; | |
2165 | } | |
2166 | ||
2167 | struct expr *sub; | |
2168 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2169 | if (sub->type == EXPR_T_CMP) { | |
2170 | continue; | |
2171 | } | |
2172 | ||
2173 | ovs_assert(sub->type == EXPR_T_OR); | |
2174 | const struct expr_symbol *symbol = expr_is_cmp(sub); | |
2175 | if (!symbol || symbol->must_crossproduct) { | |
2176 | struct expr *or = expr_create_andor(EXPR_T_OR); | |
2177 | struct expr *k; | |
2178 | ||
2179 | LIST_FOR_EACH (k, node, &sub->andor) { | |
2180 | struct expr *and = expr_create_andor(EXPR_T_AND); | |
2181 | struct expr *m; | |
2182 | ||
2183 | LIST_FOR_EACH (m, node, &expr->andor) { | |
2184 | struct expr *term = m == sub ? k : m; | |
2185 | if (term->type == EXPR_T_AND) { | |
2186 | struct expr *p; | |
2187 | ||
2188 | LIST_FOR_EACH (p, node, &term->andor) { | |
2189 | struct expr *new = expr_clone(p); | |
417e7e66 | 2190 | ovs_list_push_back(&and->andor, &new->node); |
e0840f11 BP |
2191 | } |
2192 | } else { | |
2193 | struct expr *new = expr_clone(term); | |
417e7e66 | 2194 | ovs_list_push_back(&and->andor, &new->node); |
e0840f11 BP |
2195 | } |
2196 | } | |
417e7e66 | 2197 | ovs_list_push_back(&or->andor, &and->node); |
e0840f11 BP |
2198 | } |
2199 | expr_destroy(expr); | |
2200 | return expr_normalize_or(or); | |
2201 | } | |
2202 | } | |
2203 | return expr; | |
2204 | } | |
2205 | ||
2206 | static struct expr * | |
2207 | expr_normalize_or(struct expr *expr) | |
2208 | { | |
2209 | struct expr *sub, *next; | |
2210 | ||
2211 | LIST_FOR_EACH_SAFE (sub, next, node, &expr->andor) { | |
2212 | if (sub->type == EXPR_T_AND) { | |
417e7e66 | 2213 | ovs_list_remove(&sub->node); |
e0840f11 BP |
2214 | |
2215 | struct expr *new = expr_normalize_and(sub); | |
2216 | if (new->type == EXPR_T_BOOLEAN) { | |
2217 | if (new->boolean) { | |
2218 | expr_destroy(expr); | |
2219 | return new; | |
2220 | } | |
2221 | free(new); | |
2222 | } else { | |
2223 | expr_insert_andor(expr, next, new); | |
2224 | } | |
2225 | } else { | |
2226 | ovs_assert(sub->type == EXPR_T_CMP); | |
2227 | } | |
2228 | } | |
417e7e66 | 2229 | if (ovs_list_is_empty(&expr->andor)) { |
e0840f11 BP |
2230 | free(expr); |
2231 | return expr_create_boolean(false); | |
2232 | } | |
417e7e66 BW |
2233 | if (ovs_list_is_short(&expr->andor)) { |
2234 | struct expr *sub = expr_from_node(ovs_list_pop_front(&expr->andor)); | |
e0840f11 BP |
2235 | free(expr); |
2236 | return sub; | |
2237 | } | |
2238 | ||
2239 | return expr; | |
2240 | } | |
2241 | ||
2242 | /* Takes ownership of 'expr', which is either a constant "true" or "false" or | |
2243 | * an expression in terms of only relationals, AND, and OR. Returns either a | |
2244 | * constant "true" or "false" or 'expr' reduced to OR(AND(clause)) where a | |
2245 | * clause is a cmp or a disjunction of cmps on a single field. This form is | |
2246 | * significant because it is a form that can be directly converted to OpenFlow | |
2247 | * flows with the Open vSwitch "conjunctive match" extension. | |
2248 | * | |
2249 | * 'expr' must already have been simplified, with expr_simplify(). */ | |
2250 | struct expr * | |
2251 | expr_normalize(struct expr *expr) | |
2252 | { | |
2253 | switch (expr->type) { | |
2254 | case EXPR_T_CMP: | |
2255 | return expr; | |
2256 | ||
2257 | case EXPR_T_AND: | |
2258 | return expr_normalize_and(expr); | |
2259 | ||
2260 | case EXPR_T_OR: | |
2261 | return expr_normalize_or(expr); | |
2262 | ||
2263 | case EXPR_T_BOOLEAN: | |
2264 | return expr; | |
2265 | } | |
2266 | OVS_NOT_REACHED(); | |
2267 | } | |
2268 | \f | |
2269 | /* Creates, initializes, and returns a new 'struct expr_match'. If 'm' is | |
2270 | * nonnull then it is copied into the new expr_match, otherwise the new | |
2271 | * expr_match's 'match' member is initialized to a catch-all match for the | |
2272 | * caller to refine in-place. | |
2273 | * | |
2274 | * If 'conj_id' is nonzero, adds one conjunction based on 'conj_id', 'clause', | |
2275 | * and 'n_clauses' to the returned 'struct expr_match', otherwise the | |
2276 | * expr_match will not have any conjunctions. | |
2277 | * | |
2278 | * The caller should use expr_match_add() to add the expr_match to a hash table | |
2279 | * after it is finalized. */ | |
2280 | static struct expr_match * | |
2281 | expr_match_new(const struct match *m, uint8_t clause, uint8_t n_clauses, | |
2282 | uint32_t conj_id) | |
2283 | { | |
2284 | struct expr_match *match = xmalloc(sizeof *match); | |
2285 | if (m) { | |
2286 | match->match = *m; | |
2287 | } else { | |
2288 | match_init_catchall(&match->match); | |
2289 | } | |
2290 | if (conj_id) { | |
2291 | match->conjunctions = xmalloc(sizeof *match->conjunctions); | |
2292 | match->conjunctions[0].id = conj_id; | |
2293 | match->conjunctions[0].clause = clause; | |
2294 | match->conjunctions[0].n_clauses = n_clauses; | |
2295 | match->n = 1; | |
2296 | match->allocated = 1; | |
2297 | } else { | |
2298 | match->conjunctions = NULL; | |
2299 | match->n = 0; | |
2300 | match->allocated = 0; | |
2301 | } | |
2302 | return match; | |
2303 | } | |
2304 | ||
2305 | /* Adds 'match' to hash table 'matches', which becomes the new owner of | |
2306 | * 'match'. | |
2307 | * | |
2308 | * This might actually destroy 'match' because it gets merged together with | |
2309 | * some existing conjunction.*/ | |
2310 | static void | |
2311 | expr_match_add(struct hmap *matches, struct expr_match *match) | |
2312 | { | |
2313 | uint32_t hash = match_hash(&match->match, 0); | |
2314 | struct expr_match *m; | |
2315 | ||
2316 | HMAP_FOR_EACH_WITH_HASH (m, hmap_node, hash, matches) { | |
2317 | if (match_equal(&m->match, &match->match)) { | |
2318 | if (!m->n || !match->n) { | |
2319 | free(m->conjunctions); | |
2320 | m->conjunctions = NULL; | |
2321 | m->n = 0; | |
2322 | m->allocated = 0; | |
2323 | } else { | |
2324 | ovs_assert(match->n == 1); | |
2325 | if (m->n >= m->allocated) { | |
2326 | m->conjunctions = x2nrealloc(m->conjunctions, | |
2327 | &m->allocated, | |
2328 | sizeof *m->conjunctions); | |
2329 | } | |
2330 | m->conjunctions[m->n++] = match->conjunctions[0]; | |
2331 | } | |
2332 | free(match->conjunctions); | |
2333 | free(match); | |
2334 | return; | |
2335 | } | |
2336 | } | |
2337 | ||
2338 | hmap_insert(matches, &match->hmap_node, hash); | |
2339 | } | |
2340 | ||
f386a8a7 | 2341 | static bool |
f1c16a85 BP |
2342 | constrain_match(const struct expr *expr, |
2343 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2344 | unsigned int *portp), | |
2345 | const void *aux, struct match *m) | |
e0840f11 BP |
2346 | { |
2347 | ovs_assert(expr->type == EXPR_T_CMP); | |
f386a8a7 BP |
2348 | if (expr->cmp.symbol->width) { |
2349 | mf_mask_subfield(expr->cmp.symbol->field, &expr->cmp.value, | |
2350 | &expr->cmp.mask, m); | |
2351 | } else { | |
f1c16a85 BP |
2352 | unsigned int port; |
2353 | if (!lookup_port(aux, expr->cmp.string, &port)) { | |
f386a8a7 BP |
2354 | return false; |
2355 | } | |
2356 | ||
2357 | struct mf_subfield sf; | |
2358 | sf.field = expr->cmp.symbol->field; | |
2359 | sf.ofs = 0; | |
2360 | sf.n_bits = expr->cmp.symbol->field->n_bits; | |
2361 | ||
2362 | union mf_subvalue x; | |
2363 | memset(&x, 0, sizeof x); | |
f1c16a85 | 2364 | x.integer = htonll(port); |
f386a8a7 BP |
2365 | |
2366 | mf_write_subfield(&sf, &x, m); | |
2367 | } | |
2368 | return true; | |
e0840f11 BP |
2369 | } |
2370 | ||
f386a8a7 | 2371 | static bool |
f1c16a85 BP |
2372 | add_disjunction(const struct expr *or, |
2373 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2374 | unsigned int *portp), | |
2375 | const void *aux, | |
f386a8a7 BP |
2376 | struct match *m, uint8_t clause, uint8_t n_clauses, |
2377 | uint32_t conj_id, struct hmap *matches) | |
e0840f11 BP |
2378 | { |
2379 | struct expr *sub; | |
f386a8a7 | 2380 | int n = 0; |
e0840f11 BP |
2381 | |
2382 | ovs_assert(or->type == EXPR_T_OR); | |
2383 | LIST_FOR_EACH (sub, node, &or->andor) { | |
2384 | struct expr_match *match = expr_match_new(m, clause, n_clauses, | |
2385 | conj_id); | |
f1c16a85 | 2386 | if (constrain_match(sub, lookup_port, aux, &match->match)) { |
f386a8a7 BP |
2387 | expr_match_add(matches, match); |
2388 | n++; | |
2389 | } else { | |
2390 | free(match->conjunctions); | |
2391 | free(match); | |
2392 | } | |
e0840f11 | 2393 | } |
f386a8a7 BP |
2394 | |
2395 | /* If n == 1, then this didn't really need to be a disjunction. Oh well, | |
2396 | * that shouldn't happen much. */ | |
2397 | return n > 0; | |
e0840f11 BP |
2398 | } |
2399 | ||
2400 | static void | |
f1c16a85 BP |
2401 | add_conjunction(const struct expr *and, |
2402 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2403 | unsigned int *portp), | |
2404 | const void *aux, uint32_t *n_conjsp, struct hmap *matches) | |
e0840f11 BP |
2405 | { |
2406 | struct match match; | |
2407 | int n_clauses = 0; | |
2408 | struct expr *sub; | |
2409 | ||
2410 | match_init_catchall(&match); | |
2411 | ||
2412 | ovs_assert(and->type == EXPR_T_AND); | |
2413 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2414 | switch (sub->type) { | |
2415 | case EXPR_T_CMP: | |
f1c16a85 | 2416 | if (!constrain_match(sub, lookup_port, aux, &match)) { |
f386a8a7 BP |
2417 | return; |
2418 | } | |
e0840f11 BP |
2419 | break; |
2420 | case EXPR_T_OR: | |
2421 | n_clauses++; | |
2422 | break; | |
2423 | case EXPR_T_AND: | |
2424 | case EXPR_T_BOOLEAN: | |
2425 | OVS_NOT_REACHED(); | |
2426 | } | |
2427 | } | |
2428 | ||
2429 | if (!n_clauses) { | |
2430 | expr_match_add(matches, expr_match_new(&match, 0, 0, 0)); | |
2431 | } else if (n_clauses == 1) { | |
2432 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2433 | if (sub->type == EXPR_T_OR) { | |
f1c16a85 BP |
2434 | add_disjunction(sub, lookup_port, aux, &match, 0, 0, 0, |
2435 | matches); | |
e0840f11 BP |
2436 | } |
2437 | } | |
2438 | } else { | |
2439 | int clause = 0; | |
2440 | (*n_conjsp)++; | |
2441 | LIST_FOR_EACH (sub, node, &and->andor) { | |
2442 | if (sub->type == EXPR_T_OR) { | |
f1c16a85 | 2443 | if (!add_disjunction(sub, lookup_port, aux, &match, clause++, |
f386a8a7 BP |
2444 | n_clauses, *n_conjsp, matches)) { |
2445 | /* This clause can't ever match, so we might as well skip | |
2446 | * adding the other clauses--the overall disjunctive flow | |
2447 | * can't ever match. Ideally we would also back out all of | |
2448 | * the clauses we already added, but that seems like a lot | |
2449 | * of trouble for a case that might never occur in | |
2450 | * practice. */ | |
2451 | return; | |
2452 | } | |
e0840f11 BP |
2453 | } |
2454 | } | |
40e07b2a BP |
2455 | |
2456 | /* Add the flow that matches on conj_id. */ | |
2457 | match_set_conj_id(&match, *n_conjsp); | |
2458 | expr_match_add(matches, expr_match_new(&match, 0, 0, 0)); | |
e0840f11 BP |
2459 | } |
2460 | } | |
2461 | ||
2462 | static void | |
f1c16a85 BP |
2463 | add_cmp_flow(const struct expr *cmp, |
2464 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2465 | unsigned int *portp), | |
2466 | const void *aux, struct hmap *matches) | |
e0840f11 BP |
2467 | { |
2468 | struct expr_match *m = expr_match_new(NULL, 0, 0, 0); | |
f1c16a85 | 2469 | if (constrain_match(cmp, lookup_port, aux, &m->match)) { |
f386a8a7 BP |
2470 | expr_match_add(matches, m); |
2471 | } else { | |
2472 | free(m); | |
2473 | } | |
e0840f11 BP |
2474 | } |
2475 | ||
2476 | /* Converts 'expr', which must be in the form returned by expr_normalize(), to | |
2477 | * a collection of Open vSwitch flows in 'matches', which this function | |
f386a8a7 BP |
2478 | * initializes to an hmap of "struct expr_match" structures. Returns the |
2479 | * number of conjunctive match IDs consumed by 'matches', which uses | |
2480 | * conjunctive match IDs beginning with 0; the caller must offset or remap them | |
2481 | * into the desired range as necessary. | |
2482 | * | |
40e07b2a BP |
2483 | * The matches inserted into 'matches' will be of three distinct kinds: |
2484 | * | |
2485 | * - Ordinary flows. The caller should add these OpenFlow flows with | |
2486 | * its desired actions. | |
2487 | * | |
2488 | * - Conjunctive flows, distinguished by 'n > 0' in the expr_match | |
2489 | * structure. The caller should add these OpenFlow flows with the | |
2490 | * conjunction(id, k/n) actions as specified in the 'conjunctions' array, | |
2491 | * remapping the ids. | |
2492 | * | |
2493 | * - conj_id flows, distinguished by matching on the "conj_id" field. The | |
2494 | * caller should remap the conj_id and add the OpenFlow flow with its | |
2495 | * desired actions. | |
2496 | * | |
f1c16a85 BP |
2497 | * 'lookup_port' must be a function to map from a port name to a port number. |
2498 | * When successful, 'lookup_port' stores the port number into '*portp' and | |
2499 | * returns true; when there is no port by the given name, it returns false. | |
2500 | * 'aux' is passed to 'lookup_port' as auxiliary data. Any comparisons against | |
2501 | * string fields in 'expr' are translated into integers through this function. | |
2502 | * A comparison against a string that is not in 'ports' acts like a Boolean | |
2503 | * "false"; that is, it will always fail to match. For a simple expression, | |
2504 | * this means that the overall expression always fails to match, but an | |
2505 | * expression with a disjunction on the string field might still match on other | |
2506 | * port names. | |
f386a8a7 BP |
2507 | * |
2508 | * (This treatment of string fields might be too simplistic in general, but it | |
2509 | * seems reasonable for now when string fields are used only for ports.) */ | |
e0840f11 | 2510 | uint32_t |
f1c16a85 BP |
2511 | expr_to_matches(const struct expr *expr, |
2512 | bool (*lookup_port)(const void *aux, const char *port_name, | |
2513 | unsigned int *portp), | |
2514 | const void *aux, struct hmap *matches) | |
e0840f11 BP |
2515 | { |
2516 | uint32_t n_conjs = 0; | |
2517 | ||
2518 | hmap_init(matches); | |
2519 | switch (expr->type) { | |
2520 | case EXPR_T_CMP: | |
f1c16a85 | 2521 | add_cmp_flow(expr, lookup_port, aux, matches); |
e0840f11 BP |
2522 | break; |
2523 | ||
2524 | case EXPR_T_AND: | |
f1c16a85 | 2525 | add_conjunction(expr, lookup_port, aux, &n_conjs, matches); |
e0840f11 BP |
2526 | break; |
2527 | ||
2528 | case EXPR_T_OR: | |
2529 | if (expr_is_cmp(expr)) { | |
2530 | struct expr *sub; | |
2531 | ||
2532 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
f1c16a85 | 2533 | add_cmp_flow(sub, lookup_port, aux, matches); |
e0840f11 BP |
2534 | } |
2535 | } else { | |
2536 | struct expr *sub; | |
2537 | ||
2538 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2539 | if (sub->type == EXPR_T_AND) { | |
f1c16a85 | 2540 | add_conjunction(sub, lookup_port, aux, &n_conjs, matches); |
e0840f11 | 2541 | } else { |
f1c16a85 | 2542 | add_cmp_flow(sub, lookup_port, aux, matches); |
e0840f11 BP |
2543 | } |
2544 | } | |
2545 | } | |
2546 | break; | |
2547 | ||
2548 | case EXPR_T_BOOLEAN: | |
2549 | if (expr->boolean) { | |
2550 | struct expr_match *m = expr_match_new(NULL, 0, 0, 0); | |
2551 | expr_match_add(matches, m); | |
2552 | } else { | |
2553 | /* No match. */ | |
2554 | } | |
2555 | break; | |
2556 | } | |
2557 | return n_conjs; | |
2558 | } | |
f386a8a7 BP |
2559 | |
2560 | /* Destroys all of the 'struct expr_match'es in 'matches', as well as the | |
2561 | * 'matches' hmap itself. */ | |
2562 | void | |
2563 | expr_matches_destroy(struct hmap *matches) | |
2564 | { | |
4ec3d7c7 | 2565 | struct expr_match *m; |
f386a8a7 | 2566 | |
4ec3d7c7 | 2567 | HMAP_FOR_EACH_POP (m, hmap_node, matches) { |
f386a8a7 BP |
2568 | free(m->conjunctions); |
2569 | free(m); | |
2570 | } | |
2571 | hmap_destroy(matches); | |
2572 | } | |
2573 | ||
2574 | /* Prints a representation of the 'struct expr_match'es in 'matches' to | |
2575 | * 'stream'. */ | |
2576 | void | |
2577 | expr_matches_print(const struct hmap *matches, FILE *stream) | |
2578 | { | |
2579 | if (hmap_is_empty(matches)) { | |
2580 | fputs("(no flows)\n", stream); | |
2581 | return; | |
2582 | } | |
2583 | ||
2584 | const struct expr_match *m; | |
2585 | HMAP_FOR_EACH (m, hmap_node, matches) { | |
2586 | char *s = match_to_string(&m->match, OFP_DEFAULT_PRIORITY); | |
2587 | fputs(s, stream); | |
2588 | free(s); | |
2589 | ||
2590 | if (m->n) { | |
2591 | for (int i = 0; i < m->n; i++) { | |
2592 | const struct cls_conjunction *c = &m->conjunctions[i]; | |
2593 | fprintf(stream, "%c conjunction(%"PRIu32", %d/%d)", | |
2594 | i == 0 ? ':' : ',', c->id, c->clause, c->n_clauses); | |
2595 | } | |
2596 | } | |
2597 | putc('\n', stream); | |
2598 | } | |
2599 | } | |
e0840f11 BP |
2600 | \f |
2601 | /* Returns true if 'expr' honors the invariants for expressions (see the large | |
2602 | * comment above "struct expr" in expr.h), false otherwise. */ | |
2603 | bool | |
2604 | expr_honors_invariants(const struct expr *expr) | |
2605 | { | |
2606 | const struct expr *sub; | |
2607 | ||
2608 | switch (expr->type) { | |
2609 | case EXPR_T_CMP: | |
2610 | if (expr->cmp.symbol->width) { | |
2611 | for (int i = 0; i < ARRAY_SIZE(expr->cmp.value.be64); i++) { | |
2612 | if (expr->cmp.value.be64[i] & ~expr->cmp.mask.be64[i]) { | |
2613 | return false; | |
2614 | } | |
2615 | } | |
2616 | } | |
2617 | return true; | |
2618 | ||
2619 | case EXPR_T_AND: | |
2620 | case EXPR_T_OR: | |
417e7e66 | 2621 | if (ovs_list_is_short(&expr->andor)) { |
e0840f11 BP |
2622 | return false; |
2623 | } | |
2624 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2625 | if (sub->type == expr->type || !expr_honors_invariants(sub)) { | |
2626 | return false; | |
2627 | } | |
2628 | } | |
2629 | return true; | |
2630 | ||
2631 | case EXPR_T_BOOLEAN: | |
2632 | return true; | |
2633 | ||
2634 | default: | |
2635 | OVS_NOT_REACHED(); | |
2636 | } | |
2637 | } | |
2638 | ||
2639 | static bool | |
2640 | expr_is_normalized_and(const struct expr *expr) | |
2641 | { | |
2642 | /* XXX should also check that no symbol is repeated. */ | |
2643 | const struct expr *sub; | |
2644 | ||
2645 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2646 | if (!expr_is_cmp(sub)) { | |
2647 | return false; | |
2648 | } | |
2649 | } | |
2650 | return true; | |
2651 | } | |
2652 | ||
2653 | /* Returns true if 'expr' is in the form returned by expr_normalize(), false | |
2654 | * otherwise. */ | |
2655 | bool | |
2656 | expr_is_normalized(const struct expr *expr) | |
2657 | { | |
2658 | switch (expr->type) { | |
2659 | case EXPR_T_CMP: | |
2660 | return true; | |
2661 | ||
2662 | case EXPR_T_AND: | |
2663 | return expr_is_normalized_and(expr); | |
2664 | ||
2665 | case EXPR_T_OR: | |
2666 | if (!expr_is_cmp(expr)) { | |
2667 | const struct expr *sub; | |
2668 | ||
2669 | LIST_FOR_EACH (sub, node, &expr->andor) { | |
2670 | if (!expr_is_cmp(sub) && !expr_is_normalized_and(sub)) { | |
2671 | return false; | |
2672 | } | |
2673 | } | |
2674 | } | |
2675 | return true; | |
2676 | ||
2677 | case EXPR_T_BOOLEAN: | |
2678 | return true; | |
2679 | ||
2680 | default: | |
2681 | OVS_NOT_REACHED(); | |
2682 | } | |
2683 | } | |
3b7cb7e1 BP |
2684 | \f |
2685 | /* Action parsing helper. */ | |
2686 | ||
a20c96c6 BP |
2687 | /* Expands 'f' repeatedly as long as it has an expansion, that is, as long as |
2688 | * it is a subfield or a predicate. Adds any prerequisites for 'f' to | |
2689 | * '*prereqs'. | |
2690 | * | |
2691 | * If 'rw', verifies that 'f' is a read/write field. | |
2692 | * | |
a20c96c6 BP |
2693 | * Returns true if successful, false if an error was encountered (in which case |
2694 | * 'ctx->error' reports the particular error). */ | |
5ee054fb | 2695 | static bool |
ce57ea75 | 2696 | expand_symbol(struct expr_context *ctx, bool rw, |
a20c96c6 | 2697 | struct expr_field *f, struct expr **prereqsp) |
3b7cb7e1 | 2698 | { |
a20c96c6 BP |
2699 | const struct expr_symbol *orig_symbol = f->symbol; |
2700 | ||
5ee054fb | 2701 | if (f->symbol->expansion && f->symbol->level != EXPR_L_ORDINAL) { |
ce57ea75 BP |
2702 | expr_error(ctx, "Predicate symbol %s used where lvalue required.", |
2703 | f->symbol->name); | |
5ee054fb | 2704 | return false; |
3b7cb7e1 BP |
2705 | } |
2706 | ||
3b7cb7e1 BP |
2707 | for (;;) { |
2708 | /* Accumulate prerequisites. */ | |
5ee054fb | 2709 | if (f->symbol->prereqs) { |
3b7cb7e1 BP |
2710 | struct ovs_list nesting = OVS_LIST_INITIALIZER(&nesting); |
2711 | char *error; | |
2712 | struct expr *e; | |
5ee054fb | 2713 | e = parse_and_annotate(f->symbol->prereqs, ctx->symtab, &nesting, |
3b7cb7e1 BP |
2714 | &error); |
2715 | if (error) { | |
2716 | expr_error(ctx, "%s", error); | |
2717 | free(error); | |
5ee054fb | 2718 | return false; |
3b7cb7e1 | 2719 | } |
5ee054fb | 2720 | *prereqsp = expr_combine(EXPR_T_AND, *prereqsp, e); |
3b7cb7e1 BP |
2721 | } |
2722 | ||
2723 | /* If there's no expansion, we're done. */ | |
5ee054fb | 2724 | if (!f->symbol->expansion) { |
3b7cb7e1 BP |
2725 | break; |
2726 | } | |
2727 | ||
2728 | /* Expand. */ | |
2729 | struct expr_field expansion; | |
2730 | char *error; | |
5ee054fb | 2731 | if (!parse_field_from_string(f->symbol->expansion, ctx->symtab, |
3b7cb7e1 BP |
2732 | &expansion, &error)) { |
2733 | expr_error(ctx, "%s", error); | |
2734 | free(error); | |
5ee054fb | 2735 | return false; |
3b7cb7e1 | 2736 | } |
5ee054fb BP |
2737 | f->symbol = expansion.symbol; |
2738 | f->ofs += expansion.ofs; | |
3b7cb7e1 BP |
2739 | } |
2740 | ||
a20c96c6 BP |
2741 | if (rw && !f->symbol->field->writable) { |
2742 | expr_error(ctx, "Field %s is not modifiable.", orig_symbol->name); | |
2743 | return false; | |
2744 | } | |
2745 | ||
5ee054fb BP |
2746 | return true; |
2747 | } | |
2748 | ||
a20c96c6 BP |
2749 | static void |
2750 | mf_subfield_from_expr_field(const struct expr_field *f, struct mf_subfield *sf) | |
2751 | { | |
2752 | sf->field = f->symbol->field; | |
2753 | sf->ofs = f->ofs; | |
2754 | sf->n_bits = f->n_bits ? f->n_bits : f->symbol->field->n_bits; | |
2755 | } | |
2756 | ||
2757 | static void | |
2758 | init_stack_action(const struct expr_field *f, struct ofpact_stack *stack) | |
2759 | { | |
2760 | mf_subfield_from_expr_field(f, &stack->subfield); | |
2761 | } | |
2762 | ||
8fb72d29 BP |
2763 | static char * OVS_WARN_UNUSED_RESULT |
2764 | parse_assignment(struct lexer *lexer, struct expr_field *dst, | |
2765 | const struct shash *symtab, bool exchange, | |
f1c16a85 BP |
2766 | bool (*lookup_port)(const void *aux, const char *port_name, |
2767 | unsigned int *portp), | |
8fb72d29 BP |
2768 | const void *aux, struct ofpbuf *ofpacts, |
2769 | struct expr **prereqsp) | |
5ee054fb | 2770 | { |
8fb72d29 | 2771 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
5ee054fb BP |
2772 | struct expr *prereqs = NULL; |
2773 | ||
2774 | /* Parse destination and do basic checking. */ | |
8fb72d29 BP |
2775 | const struct expr_symbol *orig_dst = dst->symbol; |
2776 | if (!expand_symbol(&ctx, true, dst, &prereqs)) { | |
5ee054fb | 2777 | goto exit; |
3b7cb7e1 BP |
2778 | } |
2779 | ||
8fb72d29 | 2780 | if (exchange || ctx.lexer->token.type == LEX_T_ID) { |
5ee054fb | 2781 | struct expr_field src; |
8fb72d29 | 2782 | if (!parse_field(&ctx, &src)) { |
5ee054fb BP |
2783 | goto exit; |
2784 | } | |
2785 | const struct expr_symbol *orig_src = src.symbol; | |
8fb72d29 | 2786 | if (!expand_symbol(&ctx, exchange, &src, &prereqs)) { |
5ee054fb BP |
2787 | goto exit; |
2788 | } | |
2789 | ||
8fb72d29 | 2790 | if ((dst->symbol->width != 0) != (src.symbol->width != 0)) { |
a20c96c6 | 2791 | if (exchange) { |
8fb72d29 | 2792 | expr_error(&ctx, |
a20c96c6 BP |
2793 | "Can't exchange %s field (%s) with %s field (%s).", |
2794 | orig_dst->width ? "integer" : "string", | |
2795 | orig_dst->name, | |
2796 | orig_src->width ? "integer" : "string", | |
2797 | orig_src->name); | |
2798 | } else { | |
8fb72d29 BP |
2799 | expr_error(&ctx, |
2800 | "Can't assign %s field (%s) to %s field (%s).", | |
a20c96c6 BP |
2801 | orig_src->width ? "integer" : "string", |
2802 | orig_src->name, | |
2803 | orig_dst->width ? "integer" : "string", | |
2804 | orig_dst->name); | |
2805 | } | |
5ee054fb BP |
2806 | goto exit; |
2807 | } | |
2808 | ||
8fb72d29 | 2809 | if (dst->n_bits != src.n_bits) { |
a20c96c6 | 2810 | if (exchange) { |
8fb72d29 | 2811 | expr_error(&ctx, |
a20c96c6 | 2812 | "Can't exchange %d-bit field with %d-bit field.", |
8fb72d29 | 2813 | dst->n_bits, src.n_bits); |
a20c96c6 | 2814 | } else { |
8fb72d29 | 2815 | expr_error(&ctx, |
a20c96c6 | 2816 | "Can't assign %d-bit value to %d-bit destination.", |
8fb72d29 | 2817 | src.n_bits, dst->n_bits); |
a20c96c6 | 2818 | } |
5ee054fb | 2819 | goto exit; |
8fb72d29 BP |
2820 | } else if (!dst->n_bits && |
2821 | dst->symbol->field->n_bits != src.symbol->field->n_bits) { | |
2822 | expr_error(&ctx, "String fields %s and %s are incompatible for " | |
a20c96c6 BP |
2823 | "%s.", orig_dst->name, orig_src->name, |
2824 | exchange ? "exchange" : "assignment"); | |
5ee054fb | 2825 | goto exit; |
3b7cb7e1 BP |
2826 | } |
2827 | ||
a20c96c6 BP |
2828 | if (exchange) { |
2829 | init_stack_action(&src, ofpact_put_STACK_PUSH(ofpacts)); | |
8fb72d29 | 2830 | init_stack_action(dst, ofpact_put_STACK_PUSH(ofpacts)); |
a20c96c6 | 2831 | init_stack_action(&src, ofpact_put_STACK_POP(ofpacts)); |
8fb72d29 | 2832 | init_stack_action(dst, ofpact_put_STACK_POP(ofpacts)); |
a20c96c6 BP |
2833 | } else { |
2834 | struct ofpact_reg_move *move = ofpact_put_REG_MOVE(ofpacts); | |
2835 | mf_subfield_from_expr_field(&src, &move->src); | |
8fb72d29 | 2836 | mf_subfield_from_expr_field(dst, &move->dst); |
a20c96c6 | 2837 | } |
3b7cb7e1 | 2838 | } else { |
5ee054fb | 2839 | struct expr_constant_set cs; |
8fb72d29 | 2840 | if (!parse_constant_set(&ctx, &cs)) { |
5ee054fb BP |
2841 | goto exit; |
2842 | } | |
2843 | ||
8fb72d29 | 2844 | if (!type_check(&ctx, dst, &cs)) { |
5ee054fb BP |
2845 | goto exit_destroy_cs; |
2846 | } | |
2847 | if (cs.in_curlies) { | |
8fb72d29 | 2848 | expr_error(&ctx, "Assignments require a single value."); |
5ee054fb BP |
2849 | goto exit_destroy_cs; |
2850 | } | |
2851 | ||
2852 | union expr_constant *c = cs.values; | |
2853 | struct ofpact_set_field *sf = ofpact_put_SET_FIELD(ofpacts); | |
8fb72d29 BP |
2854 | sf->field = dst->symbol->field; |
2855 | if (dst->symbol->width) { | |
2856 | mf_subvalue_shift(&c->value, dst->ofs); | |
5ee054fb BP |
2857 | if (!c->masked) { |
2858 | memset(&c->mask, 0, sizeof c->mask); | |
8fb72d29 | 2859 | bitwise_one(&c->mask, sizeof c->mask, dst->ofs, dst->n_bits); |
5ee054fb | 2860 | } else { |
8fb72d29 | 2861 | mf_subvalue_shift(&c->mask, dst->ofs); |
5ee054fb BP |
2862 | } |
2863 | ||
2864 | memcpy(&sf->value, | |
2865 | &c->value.u8[sizeof c->value - sf->field->n_bytes], | |
2866 | sf->field->n_bytes); | |
2867 | memcpy(&sf->mask, | |
2868 | &c->mask.u8[sizeof c->mask - sf->field->n_bytes], | |
2869 | sf->field->n_bytes); | |
2870 | } else { | |
f1c16a85 BP |
2871 | uint32_t port; |
2872 | if (!lookup_port(aux, c->string, &port)) { | |
2873 | port = 0; | |
2874 | } | |
5ee054fb BP |
2875 | bitwise_put(port, &sf->value, |
2876 | sf->field->n_bytes, 0, sf->field->n_bits); | |
b4970837 | 2877 | bitwise_one(&sf->mask, sf->field->n_bytes, 0, sf->field->n_bits); |
5ee054fb BP |
2878 | } |
2879 | ||
2880 | exit_destroy_cs: | |
2881 | expr_constant_set_destroy(&cs); | |
3b7cb7e1 BP |
2882 | } |
2883 | ||
3b7cb7e1 | 2884 | exit: |
8fb72d29 BP |
2885 | if (ctx.error) { |
2886 | expr_destroy(prereqs); | |
2887 | prereqs = NULL; | |
2888 | } | |
2889 | *prereqsp = prereqs; | |
2890 | return ctx.error; | |
3b7cb7e1 BP |
2891 | } |
2892 | ||
2893 | /* A helper for actions_parse(), to parse an OVN assignment action in the form | |
8fb72d29 BP |
2894 | * "field = value" or "field = field2" into 'ofpacts'. The caller must have |
2895 | * already parsed and skipped the left-hand side "field =" and pass in the | |
2896 | * field as 'dst'. Other parameters and return value match those for | |
2897 | * actions_parse(). */ | |
2898 | char * OVS_WARN_UNUSED_RESULT | |
2899 | expr_parse_assignment(struct lexer *lexer, struct expr_field *dst, | |
2900 | const struct shash *symtab, | |
f1c16a85 BP |
2901 | bool (*lookup_port)(const void *aux, |
2902 | const char *port_name, | |
2903 | unsigned int *portp), | |
2904 | const void *aux, | |
3b7cb7e1 | 2905 | struct ofpbuf *ofpacts, struct expr **prereqsp) |
8fb72d29 BP |
2906 | { |
2907 | return parse_assignment(lexer, dst, symtab, false, lookup_port, aux, | |
2908 | ofpacts, prereqsp); | |
2909 | } | |
2910 | ||
2911 | /* A helper for actions_parse(), to parse an OVN exchange action in the form | |
2912 | * "field1 <-> field2" into 'ofpacts'. The caller must have already parsed and | |
2913 | * skipped the left-hand side "field1 <->" and pass in 'field1'. Other | |
2914 | * parameters and return value match those for actions_parse(). */ | |
2915 | char * OVS_WARN_UNUSED_RESULT | |
2916 | expr_parse_exchange(struct lexer *lexer, struct expr_field *field, | |
2917 | const struct shash *symtab, | |
2918 | bool (*lookup_port)(const void *aux, | |
2919 | const char *port_name, | |
2920 | unsigned int *portp), | |
2921 | const void *aux, | |
2922 | struct ofpbuf *ofpacts, struct expr **prereqsp) | |
2923 | { | |
2924 | return parse_assignment(lexer, field, symtab, true, lookup_port, aux, | |
2925 | ofpacts, prereqsp); | |
2926 | } | |
2927 | ||
2928 | /* Parses a field or subfield from 'lexer' into 'field', obtaining field names | |
2929 | * from 'symtab'. Returns NULL if successful, otherwise an error message owned | |
2930 | * by the caller. */ | |
2931 | char * OVS_WARN_UNUSED_RESULT | |
2932 | expr_parse_field(struct lexer *lexer, const struct shash *symtab, | |
2933 | struct expr_field *field) | |
3b7cb7e1 | 2934 | { |
1998e474 | 2935 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
8fb72d29 BP |
2936 | if (!parse_field(&ctx, field)) { |
2937 | memset(field, 0, sizeof *field); | |
3b7cb7e1 | 2938 | } |
3b7cb7e1 BP |
2939 | return ctx.error; |
2940 | } | |
0bac7164 | 2941 | |
8fb72d29 BP |
2942 | /* Takes 'field', which was presumably parsed by expr_parse_field(), and |
2943 | * converts it into mf_subfield 'sf' and a set of prerequisites in '*prereqsp'. | |
2944 | * | |
2945 | * 'n_bits' specifies the number of bits that the field must have, and 0 | |
2946 | * indicates a string field; reports an error if 'field' has a different type | |
2947 | * or width. If 'rw' is true, it is an error if 'field' is read-only. Uses | |
2948 | * 'symtab 'for expanding references and 'lexer' for error reporting. | |
2949 | * | |
2950 | * Returns NULL if successful, otherwise an error message owned by the | |
2951 | * caller. */ | |
2952 | char * OVS_WARN_UNUSED_RESULT | |
2953 | expr_expand_field(struct lexer *lexer, const struct shash *symtab, | |
2954 | const struct expr_field *orig_field, int n_bits, bool rw, | |
2955 | struct mf_subfield *sf, struct expr **prereqsp) | |
0bac7164 | 2956 | { |
1998e474 | 2957 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; |
0bac7164 | 2958 | struct expr *prereqs = NULL; |
0bac7164 | 2959 | |
8fb72d29 | 2960 | struct expr_field field = *orig_field; |
0bac7164 BP |
2961 | if (!expand_symbol(&ctx, rw, &field, &prereqs)) { |
2962 | goto exit; | |
2963 | } | |
8fb72d29 | 2964 | ovs_assert(field.n_bits == orig_field->n_bits); |
0bac7164 BP |
2965 | |
2966 | if (n_bits != field.n_bits) { | |
2967 | if (n_bits && field.n_bits) { | |
2968 | expr_error(&ctx, "Cannot use %d-bit field %s[%d..%d] " | |
2969 | "where %d-bit field is required.", | |
8fb72d29 BP |
2970 | orig_field->n_bits, orig_field->symbol->name, |
2971 | orig_field->ofs, | |
2972 | orig_field->ofs + orig_field->n_bits - 1, n_bits); | |
0bac7164 BP |
2973 | } else if (n_bits) { |
2974 | expr_error(&ctx, "Cannot use string field %s where numeric " | |
2975 | "field is required.", | |
8fb72d29 | 2976 | orig_field->symbol->name); |
0bac7164 BP |
2977 | } else { |
2978 | expr_error(&ctx, "Cannot use numeric field %s where string " | |
2979 | "field is required.", | |
8fb72d29 | 2980 | orig_field->symbol->name); |
0bac7164 BP |
2981 | } |
2982 | } | |
2983 | ||
2984 | exit: | |
2985 | if (!ctx.error) { | |
2986 | mf_subfield_from_expr_field(&field, sf); | |
2987 | *prereqsp = prereqs; | |
2988 | } else { | |
2989 | memset(sf, 0, sizeof *sf); | |
2990 | expr_destroy(prereqs); | |
2991 | *prereqsp = NULL; | |
2992 | } | |
2993 | return ctx.error; | |
2994 | } | |
42814145 NS |
2995 | |
2996 | char * OVS_WARN_UNUSED_RESULT | |
2997 | expr_parse_constant_set(struct lexer *lexer, const struct shash *symtab, | |
2998 | struct expr_constant_set *cs) | |
2999 | { | |
3000 | struct expr_context ctx = { .lexer = lexer, .symtab = symtab }; | |
3001 | parse_constant_set(&ctx, cs); | |
3002 | return ctx.error; | |
3003 | } |