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10b1662b BP |
1 | /* |
2 | * Copyright (c) 2015 Nicira, Inc. | |
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> | |
18 | #include "lex.h" | |
19 | #include <ctype.h> | |
20 | #include <errno.h> | |
21 | #include <stdarg.h> | |
22 | #include "dynamic-string.h" | |
23 | #include "json.h" | |
24 | #include "util.h" | |
363b5330 BP |
25 | \f |
26 | /* Returns a string that represents 'format'. */ | |
27 | const char * | |
28 | lex_format_to_string(enum lex_format format) | |
29 | { | |
30 | switch (format) { | |
31 | case LEX_F_DECIMAL: | |
32 | return "decimal"; | |
33 | case LEX_F_HEXADECIMAL: | |
34 | return "hexadecimal"; | |
35 | case LEX_F_IPV4: | |
36 | return "IPv4"; | |
37 | case LEX_F_IPV6: | |
38 | return "IPv6"; | |
39 | case LEX_F_ETHERNET: | |
40 | return "Ethernet"; | |
41 | default: | |
42 | abort(); | |
43 | } | |
44 | } | |
45 | \f | |
10b1662b BP |
46 | /* Initializes 'token'. */ |
47 | void | |
48 | lex_token_init(struct lex_token *token) | |
49 | { | |
50 | token->type = LEX_T_END; | |
51 | token->s = NULL; | |
52 | } | |
53 | ||
54 | /* Frees memory owned by 'token'. */ | |
55 | void | |
56 | lex_token_destroy(struct lex_token *token) | |
57 | { | |
58 | free(token->s); | |
59 | } | |
60 | ||
61 | /* Exchanges 'a' and 'b'. */ | |
62 | void | |
63 | lex_token_swap(struct lex_token *a, struct lex_token *b) | |
64 | { | |
65 | struct lex_token tmp = *a; | |
66 | *a = *b; | |
67 | *b = tmp; | |
68 | } | |
69 | \f | |
70 | /* lex_token_format(). */ | |
71 | ||
72 | static size_t | |
73 | lex_token_n_zeros(enum lex_format format) | |
74 | { | |
75 | switch (format) { | |
76 | case LEX_F_DECIMAL: return offsetof(union mf_subvalue, integer); | |
77 | case LEX_F_HEXADECIMAL: return 0; | |
78 | case LEX_F_IPV4: return offsetof(union mf_subvalue, ipv4); | |
79 | case LEX_F_IPV6: return offsetof(union mf_subvalue, ipv6); | |
80 | case LEX_F_ETHERNET: return offsetof(union mf_subvalue, mac); | |
81 | default: OVS_NOT_REACHED(); | |
82 | } | |
83 | } | |
84 | ||
85 | /* Returns the effective format for 'token', that is, the format in which it | |
86 | * should actually be printed. This is ordinarily the same as 'token->format', | |
87 | * but it's always possible that someone sets up a token with a format that | |
88 | * won't work for a value, e.g. 'token->value' is wider than 32 bits but the | |
89 | * format is LEX_F_IPV4. (The lexer itself won't do that; this is an attempt | |
90 | * to avoid confusion in the future.) */ | |
91 | static enum lex_format | |
92 | lex_token_get_format(const struct lex_token *token) | |
93 | { | |
94 | size_t n_zeros = lex_token_n_zeros(token->format); | |
95 | return (is_all_zeros(&token->value, n_zeros) | |
96 | && (token->type != LEX_T_MASKED_INTEGER | |
97 | || is_all_zeros(&token->mask, n_zeros)) | |
98 | ? token->format | |
99 | : LEX_F_HEXADECIMAL); | |
100 | } | |
101 | ||
102 | static void | |
103 | lex_token_format_value(const union mf_subvalue *value, | |
104 | enum lex_format format, struct ds *s) | |
105 | { | |
106 | switch (format) { | |
107 | case LEX_F_DECIMAL: | |
108 | ds_put_format(s, "%"PRIu64, ntohll(value->integer)); | |
109 | break; | |
110 | ||
111 | case LEX_F_HEXADECIMAL: | |
112 | mf_format_subvalue(value, s); | |
113 | break; | |
114 | ||
115 | case LEX_F_IPV4: | |
116 | ds_put_format(s, IP_FMT, IP_ARGS(value->ipv4)); | |
117 | break; | |
118 | ||
119 | case LEX_F_IPV6: | |
120 | print_ipv6_addr(s, &value->ipv6); | |
121 | break; | |
122 | ||
123 | case LEX_F_ETHERNET: | |
124 | ds_put_format(s, ETH_ADDR_FMT, ETH_ADDR_ARGS(value->mac)); | |
125 | break; | |
126 | ||
127 | default: | |
128 | OVS_NOT_REACHED(); | |
129 | } | |
130 | ||
131 | } | |
132 | ||
133 | static void | |
134 | lex_token_format_masked_integer(const struct lex_token *token, struct ds *s) | |
135 | { | |
136 | enum lex_format format = lex_token_get_format(token); | |
137 | ||
138 | lex_token_format_value(&token->value, format, s); | |
139 | ds_put_char(s, '/'); | |
140 | ||
141 | const union mf_subvalue *mask = &token->mask; | |
142 | if (format == LEX_F_IPV4 && ip_is_cidr(mask->ipv4)) { | |
143 | ds_put_format(s, "%d", ip_count_cidr_bits(mask->ipv4)); | |
144 | } else if (token->format == LEX_F_IPV6 && ipv6_is_cidr(&mask->ipv6)) { | |
145 | ds_put_format(s, "%d", ipv6_count_cidr_bits(&mask->ipv6)); | |
146 | } else { | |
147 | lex_token_format_value(&token->mask, format, s); | |
148 | } | |
149 | } | |
150 | ||
10b1662b BP |
151 | /* Appends a string representation of 'token' to 's', in a format that can be |
152 | * losslessly parsed back by the lexer. (LEX_T_END and LEX_T_ERROR can't be | |
153 | * parsed back.) */ | |
154 | void | |
3d611299 | 155 | lex_token_format(const struct lex_token *token, struct ds *s) |
10b1662b BP |
156 | { |
157 | switch (token->type) { | |
158 | case LEX_T_END: | |
159 | ds_put_cstr(s, "$"); | |
160 | break; | |
161 | ||
162 | case LEX_T_ID: | |
163 | ds_put_cstr(s, token->s); | |
164 | break; | |
165 | ||
166 | case LEX_T_ERROR: | |
167 | ds_put_cstr(s, "error("); | |
3b626771 | 168 | json_string_escape(token->s, s); |
10b1662b BP |
169 | ds_put_char(s, ')'); |
170 | break; | |
171 | ||
172 | case LEX_T_STRING: | |
3b626771 | 173 | json_string_escape(token->s, s); |
10b1662b BP |
174 | break; |
175 | ||
176 | case LEX_T_INTEGER: | |
177 | lex_token_format_value(&token->value, lex_token_get_format(token), s); | |
178 | break; | |
179 | ||
180 | case LEX_T_MASKED_INTEGER: | |
181 | lex_token_format_masked_integer(token, s); | |
182 | break; | |
183 | ||
184 | case LEX_T_LPAREN: | |
185 | ds_put_cstr(s, "("); | |
186 | break; | |
187 | case LEX_T_RPAREN: | |
188 | ds_put_cstr(s, ")"); | |
189 | break; | |
190 | case LEX_T_LCURLY: | |
191 | ds_put_cstr(s, "{"); | |
192 | break; | |
193 | case LEX_T_RCURLY: | |
194 | ds_put_cstr(s, "}"); | |
195 | break; | |
196 | case LEX_T_LSQUARE: | |
197 | ds_put_cstr(s, "["); | |
198 | break; | |
199 | case LEX_T_RSQUARE: | |
200 | ds_put_cstr(s, "]"); | |
201 | break; | |
202 | case LEX_T_EQ: | |
203 | ds_put_cstr(s, "=="); | |
204 | break; | |
205 | case LEX_T_NE: | |
206 | ds_put_cstr(s, "!="); | |
207 | break; | |
208 | case LEX_T_LT: | |
209 | ds_put_cstr(s, "<"); | |
210 | break; | |
211 | case LEX_T_LE: | |
212 | ds_put_cstr(s, "<="); | |
213 | break; | |
214 | case LEX_T_GT: | |
215 | ds_put_cstr(s, ">"); | |
216 | break; | |
217 | case LEX_T_GE: | |
218 | ds_put_cstr(s, ">="); | |
219 | break; | |
220 | case LEX_T_LOG_NOT: | |
221 | ds_put_cstr(s, "!"); | |
222 | break; | |
223 | case LEX_T_LOG_AND: | |
224 | ds_put_cstr(s, "&&"); | |
225 | break; | |
226 | case LEX_T_LOG_OR: | |
227 | ds_put_cstr(s, "||"); | |
228 | break; | |
229 | case LEX_T_ELLIPSIS: | |
230 | ds_put_cstr(s, ".."); | |
231 | break; | |
232 | case LEX_T_COMMA: | |
233 | ds_put_cstr(s, ","); | |
234 | break; | |
235 | case LEX_T_SEMICOLON: | |
236 | ds_put_cstr(s, ";"); | |
237 | break; | |
238 | case LEX_T_EQUALS: | |
239 | ds_put_cstr(s, "="); | |
240 | break; | |
a20c96c6 BP |
241 | case LEX_T_EXCHANGE: |
242 | ds_put_cstr(s, "<->"); | |
243 | break; | |
56091efe BP |
244 | case LEX_T_DECREMENT: |
245 | ds_put_cstr(s, "--"); | |
246 | break; | |
10b1662b BP |
247 | default: |
248 | OVS_NOT_REACHED(); | |
249 | } | |
250 | ||
251 | } | |
252 | \f | |
253 | /* lex_token_parse(). */ | |
254 | ||
255 | static void OVS_PRINTF_FORMAT(2, 3) | |
256 | lex_error(struct lex_token *token, const char *message, ...) | |
257 | { | |
258 | ovs_assert(!token->s); | |
259 | token->type = LEX_T_ERROR; | |
260 | ||
261 | va_list args; | |
262 | va_start(args, message); | |
263 | token->s = xvasprintf(message, args); | |
264 | va_end(args); | |
265 | } | |
266 | ||
267 | static void | |
268 | lex_parse_hex_integer(const char *start, size_t len, struct lex_token *token) | |
269 | { | |
270 | const char *in = start + (len - 1); | |
271 | uint8_t *out = token->value.u8 + (sizeof token->value.u8 - 1); | |
272 | ||
273 | for (int i = 0; i < len; i++) { | |
274 | int hexit = hexit_value(in[-i]); | |
275 | if (hexit < 0) { | |
276 | lex_error(token, "Invalid syntax in hexadecimal constant."); | |
277 | return; | |
278 | } | |
279 | if (hexit && i / 2 >= sizeof token->value.u8) { | |
280 | lex_error(token, "Hexadecimal constant requires more than " | |
281 | "%"PRIuSIZE" bits.", 8 * sizeof token->value.u8); | |
282 | return; | |
283 | } | |
284 | out[-(i / 2)] |= i % 2 ? hexit << 4 : hexit; | |
285 | } | |
286 | token->format = LEX_F_HEXADECIMAL; | |
287 | } | |
288 | ||
289 | static const char * | |
290 | lex_parse_integer__(const char *p, struct lex_token *token) | |
291 | { | |
292 | lex_token_init(token); | |
293 | token->type = LEX_T_INTEGER; | |
294 | memset(&token->value, 0, sizeof token->value); | |
295 | const char *start = p; | |
296 | const char *end = start; | |
297 | while (isalnum((unsigned char) *end) || *end == ':' | |
298 | || (*end == '.' && end[1] != '.')) { | |
299 | end++; | |
300 | } | |
301 | size_t len = end - start; | |
302 | ||
303 | int n; | |
74ff3298 | 304 | struct eth_addr mac; |
10b1662b BP |
305 | |
306 | if (!len) { | |
307 | lex_error(token, "Integer constant expected."); | |
308 | } else if (len == 17 | |
309 | && ovs_scan(start, ETH_ADDR_SCAN_FMT"%n", | |
310 | ETH_ADDR_SCAN_ARGS(mac), &n) | |
311 | && n == len) { | |
74ff3298 | 312 | token->value.mac = mac; |
10b1662b BP |
313 | token->format = LEX_F_ETHERNET; |
314 | } else if (start + strspn(start, "0123456789") == end) { | |
315 | if (p[0] == '0' && len > 1) { | |
316 | lex_error(token, "Decimal constants must not have leading zeros."); | |
317 | } else { | |
318 | unsigned long long int integer; | |
319 | char *tail; | |
320 | ||
321 | errno = 0; | |
322 | integer = strtoull(p, &tail, 10); | |
323 | if (tail != end || errno == ERANGE) { | |
324 | lex_error(token, "Decimal constants must be less than 2**64."); | |
325 | } else { | |
326 | token->value.integer = htonll(integer); | |
327 | token->format = LEX_F_DECIMAL; | |
328 | } | |
329 | } | |
330 | } else if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) { | |
331 | if (len > 2) { | |
332 | lex_parse_hex_integer(start + 2, len - 2, token); | |
333 | } else { | |
334 | lex_error(token, "Hex digits expected following 0%c.", p[1]); | |
335 | } | |
336 | } else if (len < INET6_ADDRSTRLEN) { | |
337 | char copy[INET6_ADDRSTRLEN]; | |
338 | memcpy(copy, p, len); | |
339 | copy[len] = '\0'; | |
340 | ||
341 | struct in_addr ipv4; | |
342 | struct in6_addr ipv6; | |
343 | if (inet_pton(AF_INET, copy, &ipv4) == 1) { | |
344 | token->value.ipv4 = ipv4.s_addr; | |
345 | token->format = LEX_F_IPV4; | |
346 | } else if (inet_pton(AF_INET6, copy, &ipv6) == 1) { | |
347 | token->value.ipv6 = ipv6; | |
348 | token->format = LEX_F_IPV6; | |
349 | } else { | |
350 | lex_error(token, "Invalid numeric constant."); | |
351 | } | |
352 | } else { | |
353 | lex_error(token, "Invalid numeric constant."); | |
354 | } | |
355 | ||
356 | ovs_assert(token->type == LEX_T_INTEGER || token->type == LEX_T_ERROR); | |
357 | return end; | |
358 | } | |
359 | ||
360 | static const char * | |
361 | lex_parse_mask(const char *p, struct lex_token *token) | |
362 | { | |
363 | struct lex_token mask; | |
364 | ||
365 | /* Parse just past the '/' as a second integer. Handle errors. */ | |
366 | p = lex_parse_integer__(p + 1, &mask); | |
367 | if (mask.type == LEX_T_ERROR) { | |
368 | lex_token_swap(&mask, token); | |
369 | lex_token_destroy(&mask); | |
370 | return p; | |
371 | } | |
372 | ovs_assert(mask.type == LEX_T_INTEGER); | |
373 | ||
374 | /* Now convert the value and mask into a masked integer token. | |
375 | * We have a few special cases. */ | |
376 | token->type = LEX_T_MASKED_INTEGER; | |
377 | memset(&token->mask, 0, sizeof token->mask); | |
378 | uint32_t prefix_bits = ntohll(mask.value.integer); | |
379 | if (token->format == mask.format) { | |
380 | /* Same format value and mask is always OK. */ | |
381 | token->mask = mask.value; | |
382 | } else if (token->format == LEX_F_IPV4 | |
383 | && mask.format == LEX_F_DECIMAL | |
384 | && prefix_bits <= 32) { | |
385 | /* IPv4 address with decimal mask is a CIDR prefix. */ | |
386 | token->mask.integer = htonll(ntohl(be32_prefix_mask(prefix_bits))); | |
387 | } else if (token->format == LEX_F_IPV6 | |
388 | && mask.format == LEX_F_DECIMAL | |
389 | && prefix_bits <= 128) { | |
390 | /* IPv6 address with decimal mask is a CIDR prefix. */ | |
391 | token->mask.ipv6 = ipv6_create_mask(prefix_bits); | |
392 | } else if (token->format == LEX_F_DECIMAL | |
393 | && mask.format == LEX_F_HEXADECIMAL | |
394 | && token->value.integer == 0) { | |
395 | /* Special case for e.g. 0/0x1234. */ | |
396 | token->format = LEX_F_HEXADECIMAL; | |
397 | token->mask = mask.value; | |
398 | } else { | |
399 | lex_error(token, "Value and mask have incompatible formats."); | |
400 | return p; | |
401 | } | |
402 | ||
403 | /* Check invariant that a 1-bit in the value corresponds to a 1-bit in the | |
404 | * mask. */ | |
405 | for (int i = 0; i < ARRAY_SIZE(token->mask.be32); i++) { | |
406 | ovs_be32 v = token->value.be32[i]; | |
407 | ovs_be32 m = token->mask.be32[i]; | |
408 | ||
409 | if (v & ~m) { | |
410 | lex_error(token, "Value contains unmasked 1-bits."); | |
411 | break; | |
412 | } | |
413 | } | |
414 | ||
415 | /* Done! */ | |
416 | lex_token_destroy(&mask); | |
417 | return p; | |
418 | } | |
419 | ||
420 | static const char * | |
421 | lex_parse_integer(const char *p, struct lex_token *token) | |
422 | { | |
423 | p = lex_parse_integer__(p, token); | |
424 | if (token->type == LEX_T_INTEGER && *p == '/') { | |
425 | p = lex_parse_mask(p, token); | |
426 | } | |
427 | return p; | |
428 | } | |
429 | ||
430 | static const char * | |
431 | lex_parse_string(const char *p, struct lex_token *token) | |
432 | { | |
433 | const char *start = ++p; | |
434 | for (;;) { | |
435 | switch (*p) { | |
436 | case '\0': | |
437 | lex_error(token, "Input ends inside quoted string."); | |
438 | return p; | |
439 | ||
440 | case '"': | |
441 | token->type = (json_string_unescape(start, p - start, &token->s) | |
442 | ? LEX_T_STRING : LEX_T_ERROR); | |
443 | return p + 1; | |
444 | ||
445 | case '\\': | |
446 | p++; | |
447 | if (*p) { | |
448 | p++; | |
449 | } | |
450 | break; | |
451 | ||
452 | default: | |
453 | p++; | |
454 | break; | |
455 | } | |
456 | } | |
457 | } | |
458 | ||
459 | static bool | |
460 | lex_is_id1(unsigned char c) | |
461 | { | |
462 | return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') | |
463 | || c == '_' || c == '.'); | |
464 | } | |
465 | ||
466 | static bool | |
467 | lex_is_idn(unsigned char c) | |
468 | { | |
469 | return lex_is_id1(c) || (c >= '0' && c <= '9'); | |
470 | } | |
471 | ||
472 | static const char * | |
473 | lex_parse_id(const char *p, struct lex_token *token) | |
474 | { | |
475 | const char *start = p; | |
476 | ||
477 | do { | |
478 | p++; | |
479 | } while (lex_is_idn(*p)); | |
480 | ||
481 | token->type = LEX_T_ID; | |
482 | token->s = xmemdup0(start, p - start); | |
483 | return p; | |
484 | } | |
485 | ||
486 | /* Initializes 'token' and parses the first token from the beginning of | |
487 | * null-terminated string 'p' into 'token'. Stores a pointer to the start of | |
488 | * the token (after skipping white space and comments, if any) into '*startp'. | |
489 | * Returns the character position at which to begin parsing the next token. */ | |
490 | const char * | |
491 | lex_token_parse(struct lex_token *token, const char *p, const char **startp) | |
492 | { | |
493 | lex_token_init(token); | |
494 | ||
495 | next: | |
496 | *startp = p; | |
497 | switch (*p) { | |
498 | case '\0': | |
499 | token->type = LEX_T_END; | |
500 | return p; | |
501 | ||
502 | case ' ': case '\t': case '\n': case '\r': | |
503 | p++; | |
504 | goto next; | |
505 | ||
506 | case '/': | |
507 | p++; | |
508 | if (*p == '/') { | |
509 | do { | |
510 | p++; | |
511 | } while (*p != '\0' && *p != '\n'); | |
512 | goto next; | |
513 | } else if (*p == '*') { | |
514 | p++; | |
515 | for (;;) { | |
516 | if (*p == '*' && p[1] == '/') { | |
517 | p += 2; | |
518 | goto next; | |
519 | } else if (*p == '\0' || *p == '\n') { | |
520 | lex_error(token, "`/*' without matching `*/'."); | |
521 | return p; | |
522 | } else { | |
523 | p++; | |
524 | } | |
525 | } | |
526 | goto next; | |
527 | } else { | |
528 | lex_error(token, | |
529 | "`/' is only valid as part of `//' or `/*'."); | |
530 | } | |
531 | break; | |
532 | ||
533 | case '(': | |
534 | token->type = LEX_T_LPAREN; | |
535 | p++; | |
536 | break; | |
537 | ||
538 | case ')': | |
539 | token->type = LEX_T_RPAREN; | |
540 | p++; | |
541 | break; | |
542 | ||
543 | case '{': | |
544 | token->type = LEX_T_LCURLY; | |
545 | p++; | |
546 | break; | |
547 | ||
548 | case '}': | |
549 | token->type = LEX_T_RCURLY; | |
550 | p++; | |
551 | break; | |
552 | ||
553 | case '[': | |
554 | token->type = LEX_T_LSQUARE; | |
555 | p++; | |
556 | break; | |
557 | ||
558 | case ']': | |
559 | token->type = LEX_T_RSQUARE; | |
560 | p++; | |
561 | break; | |
562 | ||
563 | case '=': | |
564 | p++; | |
565 | if (*p == '=') { | |
566 | token->type = LEX_T_EQ; | |
567 | p++; | |
568 | } else { | |
569 | token->type = LEX_T_EQUALS; | |
570 | } | |
571 | break; | |
572 | ||
573 | case '!': | |
574 | p++; | |
575 | if (*p == '=') { | |
576 | token->type = LEX_T_NE; | |
577 | p++; | |
578 | } else { | |
579 | token->type = LEX_T_LOG_NOT; | |
580 | } | |
581 | break; | |
582 | ||
583 | case '&': | |
584 | p++; | |
585 | if (*p == '&') { | |
586 | token->type = LEX_T_LOG_AND; | |
587 | p++; | |
588 | } else { | |
589 | lex_error(token, "`&' is only valid as part of `&&'."); | |
590 | } | |
591 | break; | |
592 | ||
593 | case '|': | |
594 | p++; | |
595 | if (*p == '|') { | |
596 | token->type = LEX_T_LOG_OR; | |
597 | p++; | |
598 | } else { | |
599 | lex_error(token, "`|' is only valid as part of `||'."); | |
600 | } | |
601 | break; | |
602 | ||
603 | case '<': | |
604 | p++; | |
605 | if (*p == '=') { | |
606 | token->type = LEX_T_LE; | |
607 | p++; | |
a20c96c6 BP |
608 | } else if (*p == '-' && p[1] == '>') { |
609 | token->type = LEX_T_EXCHANGE; | |
610 | p += 2; | |
10b1662b BP |
611 | } else { |
612 | token->type = LEX_T_LT; | |
613 | } | |
614 | break; | |
615 | ||
616 | case '>': | |
617 | p++; | |
618 | if (*p == '=') { | |
619 | token->type = LEX_T_GE; | |
620 | p++; | |
621 | } else { | |
622 | token->type = LEX_T_GT; | |
623 | } | |
624 | break; | |
625 | ||
626 | case '.': | |
627 | p++; | |
628 | if (*p == '.') { | |
629 | token->type = LEX_T_ELLIPSIS; | |
630 | p++; | |
631 | } else { | |
632 | lex_error(token, "`.' is only valid as part of `..' or a number."); | |
633 | } | |
634 | break; | |
635 | ||
636 | case ',': | |
637 | p++; | |
638 | token->type = LEX_T_COMMA; | |
639 | break; | |
640 | ||
641 | case ';': | |
642 | p++; | |
643 | token->type = LEX_T_SEMICOLON; | |
644 | break; | |
645 | ||
56091efe BP |
646 | case '-': |
647 | p++; | |
648 | if (*p == '-') { | |
649 | token->type = LEX_T_DECREMENT; | |
650 | p++; | |
651 | } else { | |
652 | lex_error(token, "`-' is only valid as part of `--'."); | |
653 | } | |
654 | break; | |
655 | ||
10b1662b BP |
656 | case '0': case '1': case '2': case '3': case '4': |
657 | case '5': case '6': case '7': case '8': case '9': | |
658 | case ':': | |
659 | p = lex_parse_integer(p, token); | |
660 | break; | |
661 | ||
662 | case '"': | |
663 | p = lex_parse_string(p, token); | |
664 | break; | |
665 | ||
666 | case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': | |
667 | case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': | |
668 | /* We need to distinguish an Ethernet address or IPv6 address from an | |
669 | * identifier. Fortunately, Ethernet addresses and IPv6 addresses that | |
670 | * are ambiguous based on the first character, always start with hex | |
671 | * digits followed by a colon, but identifiers never do. */ | |
672 | p = (p[strspn(p, "0123456789abcdefABCDEF")] == ':' | |
673 | ? lex_parse_integer(p, token) | |
674 | : lex_parse_id(p, token)); | |
675 | break; | |
676 | ||
677 | default: | |
678 | if (lex_is_id1(*p)) { | |
679 | p = lex_parse_id(p, token); | |
680 | } else { | |
681 | if (isprint((unsigned char) *p)) { | |
682 | lex_error(token, "Invalid character `%c' in input.", *p); | |
683 | } else { | |
684 | lex_error(token, "Invalid byte 0x%d in input.", *p); | |
685 | } | |
686 | p++; | |
687 | } | |
688 | break; | |
689 | } | |
690 | ||
691 | return p; | |
692 | } | |
693 | \f | |
694 | /* Initializes 'lexer' for parsing 'input'. | |
695 | * | |
696 | * While the lexer is in use, 'input' must remain available, but the caller | |
697 | * otherwise retains ownership of 'input'. | |
698 | * | |
699 | * The caller must call lexer_get() to obtain the first token. */ | |
700 | void | |
701 | lexer_init(struct lexer *lexer, const char *input) | |
702 | { | |
703 | lexer->input = input; | |
704 | lexer->start = NULL; | |
705 | lex_token_init(&lexer->token); | |
706 | } | |
707 | ||
708 | /* Frees storage associated with 'lexer'. */ | |
709 | void | |
710 | lexer_destroy(struct lexer *lexer) | |
711 | { | |
712 | lex_token_destroy(&lexer->token); | |
713 | } | |
714 | ||
715 | /* Obtains the next token from 'lexer' into 'lexer->token', and returns the | |
716 | * token's type. The caller may examine 'lexer->token' directly to obtain full | |
717 | * information about the token. */ | |
718 | enum lex_type | |
719 | lexer_get(struct lexer *lexer) | |
720 | { | |
721 | lex_token_destroy(&lexer->token); | |
722 | lexer->input = lex_token_parse(&lexer->token, lexer->input, &lexer->start); | |
723 | return lexer->token.type; | |
724 | } | |
725 | ||
27912fdb BP |
726 | /* Returns the type of the next token that will be fetched by lexer_get(), |
727 | * without advancing 'lexer->token' to that token. */ | |
728 | enum lex_type | |
729 | lexer_lookahead(const struct lexer *lexer) | |
730 | { | |
731 | struct lex_token next; | |
732 | enum lex_type type; | |
733 | const char *start; | |
734 | ||
735 | lex_token_parse(&next, lexer->input, &start); | |
736 | type = next.type; | |
737 | lex_token_destroy(&next); | |
738 | return type; | |
739 | } | |
740 | ||
10b1662b BP |
741 | /* If 'lexer''s current token has the given 'type', advances 'lexer' to the |
742 | * next token and returns true. Otherwise returns false. */ | |
743 | bool | |
744 | lexer_match(struct lexer *lexer, enum lex_type type) | |
745 | { | |
746 | if (lexer->token.type == type) { | |
747 | lexer_get(lexer); | |
748 | return true; | |
749 | } else { | |
750 | return false; | |
751 | } | |
752 | } | |
27912fdb BP |
753 | |
754 | /* If 'lexer''s current token is the identifier given in 'id', advances 'lexer' | |
755 | * to the next token and returns true. Otherwise returns false. */ | |
756 | bool | |
757 | lexer_match_id(struct lexer *lexer, const char *id) | |
758 | { | |
759 | if (lexer->token.type == LEX_T_ID && !strcmp(lexer->token.s, id)) { | |
760 | lexer_get(lexer); | |
761 | return true; | |
762 | } else { | |
763 | return false; | |
764 | } | |
765 | } | |
558ec83d BP |
766 | |
767 | bool | |
768 | lexer_is_int(const struct lexer *lexer) | |
769 | { | |
770 | return (lexer->token.type == LEX_T_INTEGER | |
771 | && lexer->token.format == LEX_F_DECIMAL | |
772 | && ntohll(lexer->token.value.integer) <= INT_MAX); | |
773 | } | |
774 | ||
775 | bool | |
776 | lexer_get_int(struct lexer *lexer, int *value) | |
777 | { | |
778 | if (lexer_is_int(lexer)) { | |
779 | *value = ntohll(lexer->token.value.integer); | |
780 | lexer_get(lexer); | |
781 | return true; | |
782 | } else { | |
783 | *value = 0; | |
784 | return false; | |
785 | } | |
786 | } |