1 /*
2 * Copyright (C) 2002-2008 by Darren Reed.
3 *
4 * See the IPFILTER.LICENCE file for details on licencing.
5 *
6 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
7 * Use is subject to license terms.
8 */
9
10 #include <ctype.h>
11 #include "ipf.h"
12 #ifdef IPFILTER_SCAN
13 # include "netinet/ip_scan.h"
14 #endif
15 #include <sys/ioctl.h>
16 #include <syslog.h>
17 #ifdef TEST_LEXER
18 # define NO_YACC
19 union {
20 int num;
21 char *str;
22 struct in_addr ipa;
23 i6addr_t ip6;
24 } yylval;
25 #endif
26 #include "lexer.h"
27 #include "y.tab.h"
28
29 FILE *yyin;
30
31 #define ishex(c) (ISDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || \
32 ((c) >= 'A' && (c) <= 'F'))
33 #define TOOLONG -3
34
35 extern int string_start;
36 extern int string_end;
37 extern char *string_val;
38 extern int pos;
39 extern int yydebug;
40
41 char *yystr = NULL;
42 int yytext[YYBUFSIZ+1];
43 char yychars[YYBUFSIZ+1];
44 int yylineNum = 1;
45 int yypos = 0;
46 int yylast = -1;
47 int yyexpectaddr = 0;
48 int yybreakondot = 0;
49 int yyvarnext = 0;
50 int yytokentype = 0;
51 wordtab_t *yywordtab = NULL;
52 int yysavedepth = 0;
53 wordtab_t *yysavewords[30];
54
55
56 static wordtab_t *yyfindkey __P((char *));
57 static int yygetc __P((int));
58 static void yyunputc __P((int));
59 static int yyswallow __P((int));
60 static char *yytexttostr __P((int, int));
61 static void yystrtotext __P((char *));
62 static char *yytexttochar __P((void));
63
64 static int yygetc(docont)
65 int docont;
66 {
67 int c;
68
69 if (yypos < yylast) {
70 c = yytext[yypos++];
71 if (c == '\n')
72 yylineNum++;
73 return c;
74 }
75
76 if (yypos == YYBUFSIZ)
77 return TOOLONG;
78
79 if (pos >= string_start && pos <= string_end) {
80 c = string_val[pos - string_start];
81 yypos++;
82 } else {
83 c = fgetc(yyin);
84 if (docont && (c == '\\')) {
85 c = fgetc(yyin);
86 if (c == '\n') {
87 yylineNum++;
88 c = fgetc(yyin);
89 }
90 }
91 }
92 if (c == '\n')
93 yylineNum++;
94 yytext[yypos++] = c;
95 yylast = yypos;
96 yytext[yypos] = '\0';
97
98 return c;
99 }
100
101
102 static void yyunputc(c)
103 int c;
104 {
105 if (c == '\n')
106 yylineNum--;
107 yytext[--yypos] = c;
108 }
109
110
111 static int yyswallow(last)
112 int last;
113 {
114 int c;
115
116 while (((c = yygetc(0)) > '\0') && (c != last))
117 ;
118
119 if (c != EOF)
120 yyunputc(c);
121 if (c == last)
122 return 0;
123 return -1;
124 }
125
126
127 static char *yytexttochar()
128 {
129 int i;
130
131 for (i = 0; i < yypos; i++)
132 yychars[i] = (char)(yytext[i] & 0xff);
133 yychars[i] = '\0';
134 return yychars;
135 }
136
137
138 static void yystrtotext(str)
139 char *str;
140 {
141 int len;
142 char *s;
143
144 len = strlen(str);
145 if (len > YYBUFSIZ)
146 len = YYBUFSIZ;
147
148 for (s = str; *s != '\0' && len > 0; s++, len--)
149 yytext[yylast++] = *s;
150 yytext[yylast] = '\0';
151 }
152
153
154 static char *yytexttostr(offset, max)
155 int offset, max;
156 {
157 char *str;
158 int i;
159
160 if ((yytext[offset] == '\'' || yytext[offset] == '"') &&
161 (yytext[offset] == yytext[offset + max - 1])) {
162 offset++;
163 max--;
164 }
165
166 if (max > yylast)
167 max = yylast;
168 str = malloc(max + 1);
169 if (str != NULL) {
170 for (i = offset; i < max; i++)
171 str[i - offset] = (char)(yytext[i] & 0xff);
172 str[i - offset] = '\0';
173 }
174 return str;
175 }
176
177
178 int yylex()
179 {
180 int c, n, isbuilding, rval, lnext, nokey = 0;
181 char *name;
182
183 isbuilding = 0;
184 lnext = 0;
185 rval = 0;
186
187 if (yystr != NULL) {
188 free(yystr);
189 yystr = NULL;
190 }
191
192 nextchar:
193 c = yygetc(0);
194 if (yydebug > 1)
195 printf("yygetc = (%x) %c [%*.*s]\n", c, c, yypos, yypos,
196 yytexttochar());
197
198 switch (c)
199 {
200 case '\n' :
201 lnext = 0;
202 nokey = 0;
203 /* FALLTHROUGH */
204 case '\t' :
205 case '\r' :
206 case ' ' :
207 if (isbuilding == 1) {
208 yyunputc(c);
209 goto done;
210 }
211 if (yylast > yypos) {
212 bcopy(yytext + yypos, yytext,
213 sizeof(yytext[0]) * (yylast - yypos + 1));
214 }
215 yylast -= yypos;
216 yypos = 0;
217 lnext = 0;
218 nokey = 0;
219 goto nextchar;
220
221 case '\\' :
222 if (lnext == 0) {
223 lnext = 1;
224 if (yylast == yypos) {
225 yylast--;
226 yypos--;
227 } else
228 yypos--;
229 if (yypos == 0)
230 nokey = 1;
231 goto nextchar;
232 }
233 break;
234 }
235
236 if (lnext == 1) {
237 lnext = 0;
238 if ((isbuilding == 0) && !ISALNUM(c)) {
239 return c;
240 }
241 goto nextchar;
242 }
243
244 switch (c)
245 {
246 case '#' :
247 if (isbuilding == 1) {
248 yyunputc(c);
249 goto done;
250 }
251 yyswallow('\n');
252 rval = YY_COMMENT;
253 goto done;
254
255 case '$' :
256 if (isbuilding == 1) {
257 yyunputc(c);
258 goto done;
259 }
260 n = yygetc(0);
261 if (n == '{') {
262 if (yyswallow('}') == -1) {
263 rval = -2;
264 goto done;
265 }
266 (void) yygetc(0);
267 } else {
268 if (!ISALPHA(n)) {
269 yyunputc(n);
270 break;
271 }
272 do {
273 n = yygetc(1);
274 } while (ISALPHA(n) || ISDIGIT(n) || n == '_');
275 yyunputc(n);
276 }
277
278 name = yytexttostr(1, yypos); /* skip $ */
279
280 if (name != NULL) {
281 string_val = get_variable(name, NULL, yylineNum);
282 free(name);
283 if (string_val != NULL) {
284 name = yytexttostr(yypos, yylast);
285 if (name != NULL) {
286 yypos = 0;
287 yylast = 0;
288 yystrtotext(string_val);
289 yystrtotext(name);
290 free(string_val);
291 free(name);
292 goto nextchar;
293 }
294 free(string_val);
295 }
296 }
297 break;
298
299 case '\'':
300 case '"' :
301 if (isbuilding == 1) {
302 goto done;
303 }
304 do {
305 n = yygetc(1);
306 if (n == EOF || n == TOOLONG) {
307 rval = -2;
308 goto done;
309 }
310 if (n == '\n') {
311 yyunputc(' ');
312 yypos++;
313 }
314 } while (n != c);
315 rval = YY_STR;
316 goto done;
317 /* NOTREACHED */
318
319 case EOF :
320 yylineNum = 1;
321 yypos = 0;
322 yylast = -1;
323 yyexpectaddr = 0;
324 yybreakondot = 0;
325 yyvarnext = 0;
326 yytokentype = 0;
327 return 0;
328 }
329
330 if (strchr("=,/;{}()@", c) != NULL) {
331 if (isbuilding == 1) {
332 yyunputc(c);
333 goto done;
334 }
335 rval = c;
336 goto done;
337 } else if (c == '.') {
338 if (isbuilding == 0) {
339 rval = c;
340 goto done;
341 }
342 if (yybreakondot != 0) {
343 yyunputc(c);
344 goto done;
345 }
346 }
347
348 switch (c)
349 {
350 case '-' :
351 if (yyexpectaddr)
352 break;
353 if (isbuilding == 1)
354 break;
355 n = yygetc(0);
356 if (n == '>') {
357 isbuilding = 1;
358 goto done;
359 }
360 yyunputc(n);
361 rval = '-';
362 goto done;
363
364 case '!' :
365 if (isbuilding == 1) {
366 yyunputc(c);
367 goto done;
368 }
369 n = yygetc(0);
370 if (n == '=') {
371 rval = YY_CMP_NE;
372 goto done;
373 }
374 yyunputc(n);
375 rval = '!';
376 goto done;
377
378 case '<' :
379 if (yyexpectaddr)
380 break;
381 if (isbuilding == 1) {
382 yyunputc(c);
383 goto done;
384 }
385 n = yygetc(0);
386 if (n == '=') {
387 rval = YY_CMP_LE;
388 goto done;
389 }
390 if (n == '>') {
391 rval = YY_RANGE_OUT;
392 goto done;
393 }
394 yyunputc(n);
395 rval = YY_CMP_LT;
396 goto done;
397
398 case '>' :
399 if (yyexpectaddr)
400 break;
401 if (isbuilding == 1) {
402 yyunputc(c);
403 goto done;
404 }
405 n = yygetc(0);
406 if (n == '=') {
407 rval = YY_CMP_GE;
408 goto done;
409 }
410 if (n == '<') {
411 rval = YY_RANGE_IN;
412 goto done;
413 }
414 yyunputc(n);
415 rval = YY_CMP_GT;
416 goto done;
417 }
418
419 /*
420 * Now for the reason this is here...IPv6 address parsing.
421 * The longest string we can expect is of this form:
422 * 0000:0000:0000:0000:0000:0000:000.000.000.000
423 * not:
424 * 0000:0000:0000:0000:0000:0000:0000:0000
425 */
426 #ifdef USE_INET6
427 if (isbuilding == 0 && (ishex(c) || c == ':')) {
428 char ipv6buf[45 + 1], *s, oc;
429 int start;
430
431 start = yypos;
432 s = ipv6buf;
433 oc = c;
434
435 /*
436 * Perhaps we should implement stricter controls on what we
437 * swallow up here, but surely it would just be duplicating
438 * the code in inet_pton() anyway.
439 */
440 do {
441 *s++ = c;
442 c = yygetc(1);
443 } while ((ishex(c) || c == ':' || c == '.') &&
444 (s - ipv6buf < 46));
445 yyunputc(c);
446 *s = '\0';
447
448 if (inet_pton(AF_INET6, ipv6buf, &yylval.ip6) == 1) {
449 rval = YY_IPV6;
450 yyexpectaddr = 0;
451 goto done;
452 }
453 yypos = start;
454 c = oc;
455 }
456 #endif
457
458 if (c == ':') {
459 if (isbuilding == 1) {
460 yyunputc(c);
461 goto done;
462 }
463 rval = ':';
464 goto done;
465 }
466
467 if (isbuilding == 0 && c == '0') {
468 n = yygetc(0);
469 if (n == 'x') {
470 do {
471 n = yygetc(1);
472 } while (ishex(n));
473 yyunputc(n);
474 rval = YY_HEX;
475 goto done;
476 }
477 yyunputc(n);
478 }
479
480 /*
481 * No negative numbers with leading - sign..
482 */
483 if (isbuilding == 0 && ISDIGIT(c)) {
484 do {
485 n = yygetc(1);
486 } while (ISDIGIT(n));
487 yyunputc(n);
488 rval = YY_NUMBER;
489 goto done;
490 }
491
492 isbuilding = 1;
493 goto nextchar;
494
495 done:
496 yystr = yytexttostr(0, yypos);
497
498 if (yydebug)
499 printf("isbuilding %d yyvarnext %d nokey %d\n",
500 isbuilding, yyvarnext, nokey);
501 if (isbuilding == 1) {
502 wordtab_t *w;
503
504 w = NULL;
505 isbuilding = 0;
506
507 if ((yyvarnext == 0) && (nokey == 0)) {
508 w = yyfindkey(yystr);
509 if (w == NULL && yywordtab != NULL) {
510 yyresetdict();
511 w = yyfindkey(yystr);
512 }
513 } else
514 yyvarnext = 0;
515 if (w != NULL)
516 rval = w->w_value;
517 else
518 rval = YY_STR;
519 }
520
521 if (rval == YY_STR && yysavedepth > 0)
522 yyresetdict();
523
524 yytokentype = rval;
525
526 if (yydebug)
527 printf("lexed(%s) [%d,%d,%d] => %d @%d\n", yystr, string_start,
528 string_end, pos, rval, yysavedepth);
529
530 switch (rval)
531 {
532 case YY_NUMBER :
533 sscanf(yystr, "%u", &yylval.num);
534 break;
535
536 case YY_HEX :
537 sscanf(yystr, "0x%x", (u_int *)&yylval.num);
538 break;
539
540 case YY_STR :
541 yylval.str = strdup(yystr);
542 break;
543
544 default :
545 break;
546 }
547
548 if (yylast > 0) {
549 bcopy(yytext + yypos, yytext,
550 sizeof(yytext[0]) * (yylast - yypos + 1));
551 yylast -= yypos;
552 yypos = 0;
553 }
554
555 return rval;
556 }
557
558
559 static wordtab_t *yyfindkey(key)
560 char *key;
561 {
562 wordtab_t *w;
563
564 if (yywordtab == NULL)
565 return NULL;
566
567 for (w = yywordtab; w->w_word != 0; w++)
568 if (strcasecmp(key, w->w_word) == 0)
569 return w;
570 return NULL;
571 }
572
573
574 char *yykeytostr(num)
575 int num;
576 {
577 wordtab_t *w;
578
579 if (yywordtab == NULL)
580 return "<unknown>";
581
582 for (w = yywordtab; w->w_word; w++)
583 if (w->w_value == num)
584 return w->w_word;
585 return "<unknown>";
586 }
587
588
589 wordtab_t *yysettab(words)
590 wordtab_t *words;
591 {
592 wordtab_t *save;
593
594 save = yywordtab;
595 yywordtab = words;
596 return save;
597 }
598
599
600 void yyerror(msg)
601 char *msg;
602 {
603 char *txt, letter[2];
604 int freetxt = 0;
605
606 if (yytokentype < 256) {
607 letter[0] = yytokentype;
608 letter[1] = '\0';
609 txt = letter;
610 } else if (yytokentype == YY_STR || yytokentype == YY_HEX ||
611 yytokentype == YY_NUMBER) {
612 if (yystr == NULL) {
613 txt = yytexttostr(yypos, YYBUFSIZ);
614 if (txt == NULL) {
615 fprintf(stderr, "sorry, out of memory,"
616 " bailing out\n");
617 exit(1);
618 }
619 freetxt = 1;
620 } else
621 txt = yystr;
622 } else {
623 txt = yykeytostr(yytokentype);
624 if (txt == NULL) {
625 fprintf(stderr, "sorry, out of memory,"
626 " bailing out\n");
627 exit(1);
628 }
629 }
630 fprintf(stderr, "%s error at \"%s\", line %d\n", msg, txt, yylineNum);
631 if (freetxt == 1)
632 free(txt);
633 exit(1);
634 }
635
636
637 void yysetdict(newdict)
638 wordtab_t *newdict;
639 {
640 if (yysavedepth == sizeof(yysavewords)/sizeof(yysavewords[0])) {
641 fprintf(stderr, "%d: at maximum dictionary depth\n",
642 yylineNum);
643 return;
644 }
645
646 yysavewords[yysavedepth++] = yysettab(newdict);
647 if (yydebug)
648 printf("yysavedepth++ => %d\n", yysavedepth);
649 }
650
651 void yyresetdict()
652 {
653 if (yydebug)
654 printf("yyresetdict(%d)\n", yysavedepth);
655 if (yysavedepth > 0) {
656 yysettab(yysavewords[--yysavedepth]);
657 if (yydebug)
658 printf("yysavedepth-- => %d\n", yysavedepth);
659 }
660 }
661
662
663
664 #ifdef TEST_LEXER
665 int main(argc, argv)
666 int argc;
667 char *argv[];
668 {
669 int n;
670
671 yyin = stdin;
672
673 while ((n = yylex()) != 0)
674 printf("%d.n = %d [%s] %d %d\n",
675 yylineNum, n, yystr, yypos, yylast);
676 }
677 #endif