1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * From: Id: vfscanf.c,v 1.13 1998/09/25 12:20:27 obrien Exp
35 */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/ctype.h>
40 #include <sys/limits.h>
41 #include <sys/stddef.h>
42
43 /*
44 * Note that stdarg.h and the ANSI style va_start macro is used for both
45 * ANSI and traditional C compilers.
46 */
47 #include <machine/stdarg.h>
48
49 #define BUF 32 /* Maximum length of numeric string. */
50
51 /*
52 * Flags used during conversion.
53 */
54 #define LONG 0x01 /* l: long or double */
55 #define SHORT 0x04 /* h: short */
56 #define SUPPRESS 0x08 /* suppress assignment */
57 #define POINTER 0x10 /* weird %p pointer (`fake hex') */
58 #define NOSKIP 0x20 /* do not skip blanks */
59 #define QUAD 0x400
60 #define INTMAXT 0x800 /* j: intmax_t */
61 #define PTRDIFFT 0x1000 /* t: ptrdiff_t */
62 #define SIZET 0x2000 /* z: size_t */
63 #define SHORTSHORT 0x4000 /** hh: char */
64
65 /*
66 * The following are used in numeric conversions only:
67 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
68 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
69 */
70 #define SIGNOK 0x40 /* +/- is (still) legal */
71 #define NDIGITS 0x80 /* no digits detected */
72
73 #define DPTOK 0x100 /* (float) decimal point is still legal */
74 #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */
75
76 #define PFXOK 0x100 /* 0x prefix is (still) legal */
77 #define NZDIGITS 0x200 /* no zero digits detected */
78
79 /*
80 * Conversion types.
81 */
82 #define CT_CHAR 0 /* %c conversion */
83 #define CT_CCL 1 /* %[...] conversion */
84 #define CT_STRING 2 /* %s conversion */
85 #define CT_INT 3 /* integer, i.e., strtoq or strtouq */
86 typedef u_quad_t (*ccfntype)(const char *, char **, int);
87
88 static const u_char *__sccl(char *, const u_char *);
89
90 int
sscanf(const char * ibuf,const char * fmt,...)91 sscanf(const char *ibuf, const char *fmt, ...)
92 {
93 va_list ap;
94 int ret;
95
96 va_start(ap, fmt);
97 ret = vsscanf(ibuf, fmt, ap);
98 va_end(ap);
99 return(ret);
100 }
101
102 int
vsscanf(const char * inp,char const * fmt0,va_list ap)103 vsscanf(const char *inp, char const *fmt0, va_list ap)
104 {
105 int inr;
106 const u_char *fmt = (const u_char *)fmt0;
107 int c; /* character from format, or conversion */
108 size_t width; /* field width, or 0 */
109 char *p; /* points into all kinds of strings */
110 int n; /* handy integer */
111 int flags; /* flags as defined above */
112 char *p0; /* saves original value of p when necessary */
113 int nassigned; /* number of fields assigned */
114 int nconversions; /* number of conversions */
115 int nread; /* number of characters consumed from fp */
116 int base; /* base argument to strtoq/strtouq */
117 ccfntype ccfn; /* conversion function (strtoq/strtouq) */
118 char ccltab[256]; /* character class table for %[...] */
119 char buf[BUF]; /* buffer for numeric conversions */
120
121 /* `basefix' is used to avoid `if' tests in the integer scanner */
122 static short basefix[17] =
123 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
124
125 inr = strlen(inp);
126
127 nassigned = 0;
128 nconversions = 0;
129 nread = 0;
130 base = 0; /* XXX just to keep gcc happy */
131 ccfn = NULL; /* XXX just to keep gcc happy */
132 for (;;) {
133 c = *fmt++;
134 if (c == 0)
135 return (nassigned);
136 if (isspace(c)) {
137 while (inr > 0 && isspace(*inp))
138 nread++, inr--, inp++;
139 continue;
140 }
141 if (c != '%')
142 goto literal;
143 width = 0;
144 flags = 0;
145 /*
146 * switch on the format. continue if done;
147 * break once format type is derived.
148 */
149 again: c = *fmt++;
150 switch (c) {
151 case '%':
152 literal:
153 if (inr <= 0)
154 goto input_failure;
155 if (*inp != c)
156 goto match_failure;
157 inr--, inp++;
158 nread++;
159 continue;
160
161 case '*':
162 flags |= SUPPRESS;
163 goto again;
164 case 'j':
165 flags |= INTMAXT;
166 goto again;
167 case 'l':
168 if (flags & LONG){
169 flags &= ~LONG;
170 flags |= QUAD;
171 } else {
172 flags |= LONG;
173 }
174 goto again;
175 case 'q':
176 flags |= QUAD;
177 goto again;
178 case 't':
179 flags |= PTRDIFFT;
180 goto again;
181 case 'z':
182 flags |= SIZET;
183 goto again;
184 case 'h':
185 if (flags & SHORT){
186 flags &= ~SHORT;
187 flags |= SHORTSHORT;
188 } else {
189 flags |= SHORT;
190 }
191 goto again;
192
193 case '0': case '1': case '2': case '3': case '4':
194 case '5': case '6': case '7': case '8': case '9':
195 width = width * 10 + c - '0';
196 goto again;
197
198 /*
199 * Conversions.
200 *
201 */
202 case 'd':
203 c = CT_INT;
204 ccfn = (ccfntype)strtoq;
205 base = 10;
206 break;
207
208 case 'i':
209 c = CT_INT;
210 ccfn = (ccfntype)strtoq;
211 base = 0;
212 break;
213
214 case 'o':
215 c = CT_INT;
216 ccfn = strtouq;
217 base = 8;
218 break;
219
220 case 'u':
221 c = CT_INT;
222 ccfn = strtouq;
223 base = 10;
224 break;
225
226 case 'x':
227 flags |= PFXOK; /* enable 0x prefixing */
228 c = CT_INT;
229 ccfn = strtouq;
230 base = 16;
231 break;
232
233 case 's':
234 c = CT_STRING;
235 break;
236
237 case '[':
238 fmt = __sccl(ccltab, fmt);
239 flags |= NOSKIP;
240 c = CT_CCL;
241 break;
242
243 case 'c':
244 flags |= NOSKIP;
245 c = CT_CHAR;
246 break;
247
248 case 'p': /* pointer format is like hex */
249 flags |= POINTER | PFXOK;
250 c = CT_INT;
251 ccfn = strtouq;
252 base = 16;
253 break;
254
255 case 'n':
256 nconversions++;
257 if (flags & SUPPRESS) /* ??? */
258 continue;
259 if (flags & SHORTSHORT)
260 *va_arg(ap, char *) = nread;
261 else if (flags & SHORT)
262 *va_arg(ap, short *) = nread;
263 else if (flags & LONG)
264 *va_arg(ap, long *) = nread;
265 else if (flags & QUAD)
266 *va_arg(ap, quad_t *) = nread;
267 else if (flags & INTMAXT)
268 *va_arg(ap, intmax_t *) = nread;
269 else if (flags & SIZET)
270 *va_arg(ap, size_t *) = nread;
271 else if (flags & PTRDIFFT)
272 *va_arg(ap, ptrdiff_t *) = nread;
273 else
274 *va_arg(ap, int *) = nread;
275 continue;
276 }
277
278 /*
279 * We have a conversion that requires input.
280 */
281 if (inr <= 0)
282 goto input_failure;
283
284 /*
285 * Consume leading white space, except for formats
286 * that suppress this.
287 */
288 if ((flags & NOSKIP) == 0) {
289 while (isspace(*inp)) {
290 nread++;
291 if (--inr > 0)
292 inp++;
293 else
294 goto input_failure;
295 }
296 /*
297 * Note that there is at least one character in
298 * the buffer, so conversions that do not set NOSKIP
299 * can no longer result in an input failure.
300 */
301 }
302
303 /*
304 * Do the conversion.
305 */
306 switch (c) {
307 case CT_CHAR:
308 /* scan arbitrary characters (sets NOSKIP) */
309 if (width == 0)
310 width = 1;
311 if (flags & SUPPRESS) {
312 size_t sum = 0;
313 for (;;) {
314 if ((n = inr) < width) {
315 sum += n;
316 width -= n;
317 inp += n;
318 if (sum == 0)
319 goto input_failure;
320 break;
321 } else {
322 sum += width;
323 inr -= width;
324 inp += width;
325 break;
326 }
327 }
328 nread += sum;
329 } else {
330 bcopy(inp, va_arg(ap, char *), width);
331 inr -= width;
332 inp += width;
333 nread += width;
334 nassigned++;
335 }
336 nconversions++;
337 break;
338
339 case CT_CCL:
340 /* scan a (nonempty) character class (sets NOSKIP) */
341 if (width == 0)
342 width = (size_t)~0; /* `infinity' */
343 /* take only those things in the class */
344 if (flags & SUPPRESS) {
345 n = 0;
346 while (ccltab[(unsigned char)*inp]) {
347 n++, inr--, inp++;
348 if (--width == 0)
349 break;
350 if (inr <= 0) {
351 if (n == 0)
352 goto input_failure;
353 break;
354 }
355 }
356 if (n == 0)
357 goto match_failure;
358 } else {
359 p0 = p = va_arg(ap, char *);
360 while (ccltab[(unsigned char)*inp]) {
361 inr--;
362 *p++ = *inp++;
363 if (--width == 0)
364 break;
365 if (inr <= 0) {
366 if (p == p0)
367 goto input_failure;
368 break;
369 }
370 }
371 n = p - p0;
372 if (n == 0)
373 goto match_failure;
374 *p = 0;
375 nassigned++;
376 }
377 nread += n;
378 nconversions++;
379 break;
380
381 case CT_STRING:
382 /* like CCL, but zero-length string OK, & no NOSKIP */
383 if (width == 0)
384 width = (size_t)~0;
385 if (flags & SUPPRESS) {
386 n = 0;
387 while (!isspace(*inp)) {
388 n++, inr--, inp++;
389 if (--width == 0)
390 break;
391 if (inr <= 0)
392 break;
393 }
394 nread += n;
395 } else {
396 p0 = p = va_arg(ap, char *);
397 while (!isspace(*inp)) {
398 inr--;
399 *p++ = *inp++;
400 if (--width == 0)
401 break;
402 if (inr <= 0)
403 break;
404 }
405 *p = 0;
406 nread += p - p0;
407 nassigned++;
408 }
409 nconversions++;
410 continue;
411
412 case CT_INT:
413 /* scan an integer as if by strtoq/strtouq */
414 #ifdef hardway
415 if (width == 0 || width > sizeof(buf) - 1)
416 width = sizeof(buf) - 1;
417 #else
418 /* size_t is unsigned, hence this optimisation */
419 if (--width > sizeof(buf) - 2)
420 width = sizeof(buf) - 2;
421 width++;
422 #endif
423 flags |= SIGNOK | NDIGITS | NZDIGITS;
424 for (p = buf; width; width--) {
425 c = *inp;
426 /*
427 * Switch on the character; `goto ok'
428 * if we accept it as a part of number.
429 */
430 switch (c) {
431 /*
432 * The digit 0 is always legal, but is
433 * special. For %i conversions, if no
434 * digits (zero or nonzero) have been
435 * scanned (only signs), we will have
436 * base==0. In that case, we should set
437 * it to 8 and enable 0x prefixing.
438 * Also, if we have not scanned zero digits
439 * before this, do not turn off prefixing
440 * (someone else will turn it off if we
441 * have scanned any nonzero digits).
442 */
443 case '0':
444 if (base == 0) {
445 base = 8;
446 flags |= PFXOK;
447 }
448 if (flags & NZDIGITS)
449 flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
450 else
451 flags &= ~(SIGNOK|PFXOK|NDIGITS);
452 goto ok;
453
454 /* 1 through 7 always legal */
455 case '1': case '2': case '3':
456 case '4': case '5': case '6': case '7':
457 base = basefix[base];
458 flags &= ~(SIGNOK | PFXOK | NDIGITS);
459 goto ok;
460
461 /* digits 8 and 9 ok iff decimal or hex */
462 case '8': case '9':
463 base = basefix[base];
464 if (base <= 8)
465 break; /* not legal here */
466 flags &= ~(SIGNOK | PFXOK | NDIGITS);
467 goto ok;
468
469 /* letters ok iff hex */
470 case 'A': case 'B': case 'C':
471 case 'D': case 'E': case 'F':
472 case 'a': case 'b': case 'c':
473 case 'd': case 'e': case 'f':
474 /* no need to fix base here */
475 if (base <= 10)
476 break; /* not legal here */
477 flags &= ~(SIGNOK | PFXOK | NDIGITS);
478 goto ok;
479
480 /* sign ok only as first character */
481 case '+': case '-':
482 if (flags & SIGNOK) {
483 flags &= ~SIGNOK;
484 goto ok;
485 }
486 break;
487
488 /* x ok iff flag still set & 2nd char */
489 case 'x': case 'X':
490 if (flags & PFXOK && p == buf + 1) {
491 base = 16; /* if %i */
492 flags &= ~PFXOK;
493 goto ok;
494 }
495 break;
496 }
497
498 /*
499 * If we got here, c is not a legal character
500 * for a number. Stop accumulating digits.
501 */
502 break;
503 ok:
504 /*
505 * c is legal: store it and look at the next.
506 */
507 *p++ = c;
508 if (--inr > 0)
509 inp++;
510 else
511 break; /* end of input */
512 }
513 /*
514 * If we had only a sign, it is no good; push
515 * back the sign. If the number ends in `x',
516 * it was [sign] '0' 'x', so push back the x
517 * and treat it as [sign] '0'.
518 */
519 if (flags & NDIGITS) {
520 if (p > buf) {
521 inp--;
522 inr++;
523 }
524 goto match_failure;
525 }
526 c = ((u_char *)p)[-1];
527 if (c == 'x' || c == 'X') {
528 --p;
529 inp--;
530 inr++;
531 }
532 if ((flags & SUPPRESS) == 0) {
533 u_quad_t res;
534
535 *p = 0;
536 res = (*ccfn)(buf, (char **)NULL, base);
537 if (flags & POINTER)
538 *va_arg(ap, void **) =
539 (void *)(uintptr_t)res;
540 else if (flags & SHORTSHORT)
541 *va_arg(ap, char *) = res;
542 else if (flags & SHORT)
543 *va_arg(ap, short *) = res;
544 else if (flags & LONG)
545 *va_arg(ap, long *) = res;
546 else if (flags & QUAD)
547 *va_arg(ap, quad_t *) = res;
548 else if (flags & INTMAXT)
549 *va_arg(ap, intmax_t *) = res;
550 else if (flags & PTRDIFFT)
551 *va_arg(ap, ptrdiff_t *) = res;
552 else if (flags & SIZET)
553 *va_arg(ap, size_t *) = res;
554 else
555 *va_arg(ap, int *) = res;
556 nassigned++;
557 }
558 nread += p - buf;
559 nconversions++;
560 break;
561 }
562 }
563 input_failure:
564 return (nconversions != 0 ? nassigned : -1);
565 match_failure:
566 return (nassigned);
567 }
568
569 /*
570 * Fill in the given table from the scanset at the given format
571 * (just after `['). Return a pointer to the character past the
572 * closing `]'. The table has a 1 wherever characters should be
573 * considered part of the scanset.
574 */
575 static const u_char *
__sccl(char * tab,const u_char * fmt)576 __sccl(char *tab, const u_char *fmt)
577 {
578 int c, n, v;
579
580 /* first `clear' the whole table */
581 c = *fmt++; /* first char hat => negated scanset */
582 if (c == '^') {
583 v = 1; /* default => accept */
584 c = *fmt++; /* get new first char */
585 } else
586 v = 0; /* default => reject */
587
588 /* XXX: Will not work if sizeof(tab*) > sizeof(char) */
589 for (n = 0; n < 256; n++)
590 tab[n] = v; /* memset(tab, v, 256) */
591
592 if (c == 0)
593 return (fmt - 1);/* format ended before closing ] */
594
595 /*
596 * Now set the entries corresponding to the actual scanset
597 * to the opposite of the above.
598 *
599 * The first character may be ']' (or '-') without being special;
600 * the last character may be '-'.
601 */
602 v = 1 - v;
603 for (;;) {
604 tab[c] = v; /* take character c */
605 doswitch:
606 n = *fmt++; /* and examine the next */
607 switch (n) {
608 case 0: /* format ended too soon */
609 return (fmt - 1);
610
611 case '-':
612 /*
613 * A scanset of the form
614 * [01+-]
615 * is defined as `the digit 0, the digit 1,
616 * the character +, the character -', but
617 * the effect of a scanset such as
618 * [a-zA-Z0-9]
619 * is implementation defined. The V7 Unix
620 * scanf treats `a-z' as `the letters a through
621 * z', but treats `a-a' as `the letter a, the
622 * character -, and the letter a'.
623 *
624 * For compatibility, the `-' is not considered
625 * to define a range if the character following
626 * it is either a close bracket (required by ANSI)
627 * or is not numerically greater than the character
628 * we just stored in the table (c).
629 */
630 n = *fmt;
631 if (n == ']' || n < c) {
632 c = '-';
633 break; /* resume the for(;;) */
634 }
635 fmt++;
636 /* fill in the range */
637 do {
638 tab[++c] = v;
639 } while (c < n);
640 c = n;
641 /*
642 * Alas, the V7 Unix scanf also treats formats
643 * such as [a-c-e] as `the letters a through e'.
644 * This too is permitted by the standard....
645 */
646 goto doswitch;
647 break;
648
649 case ']': /* end of scanset */
650 return (fmt);
651
652 default: /* just another character */
653 c = n;
654 break;
655 }
656 }
657 /* NOTREACHED */
658 }
659