Replace all casts of NULL to something with NULL.
[dragonfly.git] / sys / kern / subr_scanf.c
1 /*-
2  * Copyright (c) 1990, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by the University of
19  *      California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * $FreeBSD: src/sys/kern/subr_scanf.c,v 1.13 1999/11/24 01:03:01 archie Exp $
37  * $DragonFly: src/sys/kern/subr_scanf.c,v 1.4 2006/12/13 21:58:50 dillon Exp $
38  * From: Id: vfscanf.c,v 1.13 1998/09/25 12:20:27 obrien Exp 
39  * From: static char sccsid[] = "@(#)strtol.c   8.1 (Berkeley) 6/4/93";
40  * From: static char sccsid[] = "@(#)strtoul.c  8.1 (Berkeley) 6/4/93";
41  */
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/ctype.h>
46 #include <machine/limits.h>
47
48 /*
49  * Note that stdarg.h and the ANSI style va_start macro is used for both
50  * ANSI and traditional C compilers.
51  */
52 #include <machine/stdarg.h>
53
54 #define BUF             32      /* Maximum length of numeric string. */
55
56 /*
57  * Flags used during conversion.
58  */
59 #define LONG            0x01    /* l: long or double */
60 #define SHORT           0x04    /* h: short */
61 #define SUPPRESS        0x08    /* suppress assignment */
62 #define POINTER         0x10    /* weird %p pointer (`fake hex') */
63 #define NOSKIP          0x20    /* do not skip blanks */
64 #define QUAD            0x400
65
66 /*
67  * The following are used in numeric conversions only:
68  * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
69  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
70  */
71 #define SIGNOK          0x40    /* +/- is (still) legal */
72 #define NDIGITS         0x80    /* no digits detected */
73
74 #define DPTOK           0x100   /* (float) decimal point is still legal */
75 #define EXPOK           0x200   /* (float) exponent (e+3, etc) still legal */
76
77 #define PFXOK           0x100   /* 0x prefix is (still) legal */
78 #define NZDIGITS        0x200   /* no zero digits detected */
79
80 /*
81  * Conversion types.
82  */
83 #define CT_CHAR         0       /* %c conversion */
84 #define CT_CCL          1       /* %[...] conversion */
85 #define CT_STRING       2       /* %s conversion */
86 #define CT_INT          3       /* integer, i.e., strtoq or strtouq */
87 typedef u_quad_t (*ccfntype)(const char *, char **, int);
88
89 static const u_char *__sccl(char *, const u_char *);
90
91 int
92 ksscanf(const char *ibuf, const char *fmt, ...)
93 {
94         __va_list ap;
95         int ret;
96         
97         __va_start(ap, fmt);
98         ret = kvsscanf(ibuf, fmt, ap);
99         __va_end(ap);
100         return(ret);
101 }
102
103 int
104 kvsscanf(const char *inp, char const *fmt0, __va_list ap)
105 {
106         int inr;
107         const u_char *fmt = (const u_char *)fmt0;
108         int c;                  /* character from format, or conversion */
109         size_t width;           /* field width, or 0 */
110         char *p;                /* points into all kinds of strings */
111         int n;                  /* handy integer */
112         int flags;              /* flags as defined above */
113         char *p0;               /* saves original value of p when necessary */
114         int nassigned;          /* number of fields assigned */
115         int nconversions;       /* number of conversions */
116         int nread;              /* number of characters consumed from fp */
117         int base;               /* base argument to strtoq/strtouq */
118         ccfntype ccfn;          /* conversion function (strtoq/strtouq) */
119         char ccltab[256];       /* character class table for %[...] */
120         char buf[BUF];          /* buffer for numeric conversions */
121
122         /* `basefix' is used to avoid `if' tests in the integer scanner */
123         static short basefix[17] =
124                 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
125
126         inr = strlen(inp);
127         
128         nassigned = 0;
129         nconversions = 0;
130         nread = 0;
131         base = 0;               /* XXX just to keep gcc happy */
132         ccfn = NULL;            /* XXX just to keep gcc happy */
133         for (;;) {
134                 c = *fmt++;
135                 if (c == 0)
136                         return (nassigned);
137                 if (isspace(c)) {
138                         while (inr > 0 && isspace(*inp))
139                                 nread++, inr--, inp++;
140                         continue;
141                 }
142                 if (c != '%')
143                         goto literal;
144                 width = 0;
145                 flags = 0;
146                 /*
147                  * switch on the format.  continue if done;
148                  * break once format type is derived.
149                  */
150 again:          c = *fmt++;
151                 switch (c) {
152                 case '%':
153 literal:
154                         if (inr <= 0)
155                                 goto input_failure;
156                         if (*inp != c)
157                                 goto match_failure;
158                         inr--, inp++;
159                         nread++;
160                         continue;
161
162                 case '*':
163                         flags |= SUPPRESS;
164                         goto again;
165                 case 'l':
166                         flags |= LONG;
167                         goto again;
168                 case 'q':
169                         flags |= QUAD;
170                         goto again;
171                 case 'h':
172                         flags |= SHORT;
173                         goto again;
174
175                 case '0': case '1': case '2': case '3': case '4':
176                 case '5': case '6': case '7': case '8': case '9':
177                         width = width * 10 + c - '0';
178                         goto again;
179
180                 /*
181                  * Conversions.
182                  *
183                  */
184                 case 'd':
185                         c = CT_INT;
186                         ccfn = (ccfntype)strtoq;
187                         base = 10;
188                         break;
189
190                 case 'i':
191                         c = CT_INT;
192                         ccfn = (ccfntype)strtoq;
193                         base = 0;
194                         break;
195
196                 case 'o':
197                         c = CT_INT;
198                         ccfn = strtouq;
199                         base = 8;
200                         break;
201
202                 case 'u':
203                         c = CT_INT;
204                         ccfn = strtouq;
205                         base = 10;
206                         break;
207
208                 case 'x':
209                         flags |= PFXOK; /* enable 0x prefixing */
210                         c = CT_INT;
211                         ccfn = strtouq;
212                         base = 16;
213                         break;
214
215                 case 's':
216                         c = CT_STRING;
217                         break;
218
219                 case '[':
220                         fmt = __sccl(ccltab, fmt);
221                         flags |= NOSKIP;
222                         c = CT_CCL;
223                         break;
224
225                 case 'c':
226                         flags |= NOSKIP;
227                         c = CT_CHAR;
228                         break;
229
230                 case 'p':       /* pointer format is like hex */
231                         flags |= POINTER | PFXOK;
232                         c = CT_INT;
233                         ccfn = strtouq;
234                         base = 16;
235                         break;
236
237                 case 'n':
238                         nconversions++;
239                         if (flags & SUPPRESS)   /* ??? */
240                                 continue;
241                         if (flags & SHORT)
242                                 *__va_arg(ap, short *) = nread;
243                         else if (flags & LONG)
244                                 *__va_arg(ap, long *) = nread;
245                         else if (flags & QUAD)
246                                 *__va_arg(ap, quad_t *) = nread;
247                         else
248                                 *__va_arg(ap, int *) = nread;
249                         continue;
250                 }
251
252                 /*
253                  * We have a conversion that requires input.
254                  */
255                 if (inr <= 0)
256                         goto input_failure;
257
258                 /*
259                  * Consume leading white space, except for formats
260                  * that suppress this.
261                  */
262                 if ((flags & NOSKIP) == 0) {
263                         while (isspace(*inp)) {
264                                 nread++;
265                                 if (--inr > 0)
266                                         inp++;
267                                 else 
268                                         goto input_failure;
269                         }
270                         /*
271                          * Note that there is at least one character in
272                          * the buffer, so conversions that do not set NOSKIP
273                          * can no longer result in an input failure.
274                          */
275                 }
276
277                 /*
278                  * Do the conversion.
279                  */
280                 switch (c) {
281
282                 case CT_CHAR:
283                         /* scan arbitrary characters (sets NOSKIP) */
284                         if (width == 0)
285                                 width = 1;
286                         if (flags & SUPPRESS) {
287                                 size_t sum = 0;
288                                 for (;;) {
289                                         if ((n = inr) < width) {
290                                                 sum += n;
291                                                 width -= n;
292                                                 inp += n;
293                                                 if (sum == 0)
294                                                         goto input_failure;
295                                                 break;
296                                         } else {
297                                                 sum += width;
298                                                 inr -= width;
299                                                 inp += width;
300                                                 break;
301                                         }
302                                 }
303                                 nread += sum;
304                         } else {
305                                 bcopy(inp, __va_arg(ap, char *), width);
306                                 inr -= width;
307                                 inp += width;
308                                 nread += width;
309                                 nassigned++;
310                         }
311                         nconversions++;
312                         break;
313
314                 case CT_CCL:
315                         /* scan a (nonempty) character class (sets NOSKIP) */
316                         if (width == 0)
317                                 width = (size_t)~0;     /* `infinity' */
318                         /* take only those things in the class */
319                         if (flags & SUPPRESS) {
320                                 n = 0;
321                                 while (ccltab[(unsigned char)*inp]) {
322                                         n++, inr--, inp++;
323                                         if (--width == 0)
324                                                 break;
325                                         if (inr <= 0) {
326                                                 if (n == 0)
327                                                         goto input_failure;
328                                                 break;
329                                         }
330                                 }
331                                 if (n == 0)
332                                         goto match_failure;
333                         } else {
334                                 p0 = p = __va_arg(ap, char *);
335                                 while (ccltab[(unsigned char)*inp]) {
336                                         inr--;
337                                         *p++ = *inp++;
338                                         if (--width == 0)
339                                                 break;
340                                         if (inr <= 0) {
341                                                 if (p == p0)
342                                                         goto input_failure;
343                                                 break;
344                                         }
345                                 }
346                                 n = p - p0;
347                                 if (n == 0)
348                                         goto match_failure;
349                                 *p = 0;
350                                 nassigned++;
351                         }
352                         nread += n;
353                         nconversions++;
354                         break;
355
356                 case CT_STRING:
357                         /* like CCL, but zero-length string OK, & no NOSKIP */
358                         if (width == 0)
359                                 width = (size_t)~0;
360                         if (flags & SUPPRESS) {
361                                 n = 0;
362                                 while (!isspace(*inp)) {
363                                         n++, inr--, inp++;
364                                         if (--width == 0)
365                                                 break;
366                                         if (inr <= 0)
367                                                 break;
368                                 }
369                                 nread += n;
370                         } else {
371                                 p0 = p = __va_arg(ap, char *);
372                                 while (!isspace(*inp)) {
373                                         inr--;
374                                         *p++ = *inp++;
375                                         if (--width == 0)
376                                                 break;
377                                         if (inr <= 0)
378                                                 break;
379                                 }
380                                 *p = 0;
381                                 nread += p - p0;
382                                 nassigned++;
383                         }
384                         nconversions++;
385                         continue;
386
387                 case CT_INT:
388                         /* scan an integer as if by strtoq/strtouq */
389 #ifdef hardway
390                         if (width == 0 || width > sizeof(buf) - 1)
391                                 width = sizeof(buf) - 1;
392 #else
393                         /* size_t is unsigned, hence this optimisation */
394                         if (--width > sizeof(buf) - 2)
395                                 width = sizeof(buf) - 2;
396                         width++;
397 #endif
398                         flags |= SIGNOK | NDIGITS | NZDIGITS;
399                         for (p = buf; width; width--) {
400                                 c = *inp;
401                                 /*
402                                  * Switch on the character; `goto ok'
403                                  * if we accept it as a part of number.
404                                  */
405                                 switch (c) {
406
407                                 /*
408                                  * The digit 0 is always legal, but is
409                                  * special.  For %i conversions, if no
410                                  * digits (zero or nonzero) have been
411                                  * scanned (only signs), we will have
412                                  * base==0.  In that case, we should set
413                                  * it to 8 and enable 0x prefixing.
414                                  * Also, if we have not scanned zero digits
415                                  * before this, do not turn off prefixing
416                                  * (someone else will turn it off if we
417                                  * have scanned any nonzero digits).
418                                  */
419                                 case '0':
420                                         if (base == 0) {
421                                                 base = 8;
422                                                 flags |= PFXOK;
423                                         }
424                                         if (flags & NZDIGITS)
425                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
426                                         else
427                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
428                                         goto ok;
429
430                                 /* 1 through 7 always legal */
431                                 case '1': case '2': case '3':
432                                 case '4': case '5': case '6': case '7':
433                                         base = basefix[base];
434                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
435                                         goto ok;
436
437                                 /* digits 8 and 9 ok iff decimal or hex */
438                                 case '8': case '9':
439                                         base = basefix[base];
440                                         if (base <= 8)
441                                                 break;  /* not legal here */
442                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
443                                         goto ok;
444
445                                 /* letters ok iff hex */
446                                 case 'A': case 'B': case 'C':
447                                 case 'D': case 'E': case 'F':
448                                 case 'a': case 'b': case 'c':
449                                 case 'd': case 'e': case 'f':
450                                         /* no need to fix base here */
451                                         if (base <= 10)
452                                                 break;  /* not legal here */
453                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
454                                         goto ok;
455
456                                 /* sign ok only as first character */
457                                 case '+': case '-':
458                                         if (flags & SIGNOK) {
459                                                 flags &= ~SIGNOK;
460                                                 goto ok;
461                                         }
462                                         break;
463
464                                 /* x ok iff flag still set & 2nd char */
465                                 case 'x': case 'X':
466                                         if (flags & PFXOK && p == buf + 1) {
467                                                 base = 16;      /* if %i */
468                                                 flags &= ~PFXOK;
469                                                 goto ok;
470                                         }
471                                         break;
472                                 }
473
474                                 /*
475                                  * If we got here, c is not a legal character
476                                  * for a number.  Stop accumulating digits.
477                                  */
478                                 break;
479                 ok:
480                                 /*
481                                  * c is legal: store it and look at the next.
482                                  */
483                                 *p++ = c;
484                                 if (--inr > 0)
485                                         inp++;
486                                 else 
487                                         break;          /* end of input */
488                         }
489                         /*
490                          * If we had only a sign, it is no good; push
491                          * back the sign.  If the number ends in `x',
492                          * it was [sign] '0' 'x', so push back the x
493                          * and treat it as [sign] '0'.
494                          */
495                         if (flags & NDIGITS) {
496                                 if (p > buf) {
497                                         inp--;
498                                         inr++;
499                                 }
500                                 goto match_failure;
501                         }
502                         c = ((u_char *)p)[-1];
503                         if (c == 'x' || c == 'X') {
504                                 --p;
505                                 inp--;
506                                 inr++;
507                         }
508                         if ((flags & SUPPRESS) == 0) {
509                                 u_quad_t res;
510
511                                 *p = 0;
512                                 res = (*ccfn)(buf, NULL, base);
513                                 if (flags & POINTER)
514                                         *__va_arg(ap, void **) =
515                                                 (void *)(uintptr_t)res;
516                                 else if (flags & SHORT)
517                                         *__va_arg(ap, short *) = res;
518                                 else if (flags & LONG)
519                                         *__va_arg(ap, long *) = res;
520                                 else if (flags & QUAD)
521                                         *__va_arg(ap, quad_t *) = res;
522                                 else
523                                         *__va_arg(ap, int *) = res;
524                                 nassigned++;
525                         }
526                         nread += p - buf;
527                         nconversions++;
528                         break;
529
530                 }
531         }
532 input_failure:
533         return (nconversions != 0 ? nassigned : -1);
534 match_failure:
535         return (nassigned);
536 }
537
538 /*
539  * Fill in the given table from the scanset at the given format
540  * (just after `[').  Return a pointer to the character past the
541  * closing `]'.  The table has a 1 wherever characters should be
542  * considered part of the scanset.
543  */
544 static const u_char *
545 __sccl(char *tab, const u_char *fmt)
546 {
547         int c, n, v;
548
549         /* first `clear' the whole table */
550         c = *fmt++;             /* first char hat => negated scanset */
551         if (c == '^') {
552                 v = 1;          /* default => accept */
553                 c = *fmt++;     /* get new first char */
554         } else
555                 v = 0;          /* default => reject */
556
557         /* XXX: Will not work if sizeof(tab*) > sizeof(char) */
558         for (n = 0; n < 256; n++)
559                      tab[n] = v;        /* memset(tab, v, 256) */
560
561         if (c == 0)
562                 return (fmt - 1);/* format ended before closing ] */
563
564         /*
565          * Now set the entries corresponding to the actual scanset
566          * to the opposite of the above.
567          *
568          * The first character may be ']' (or '-') without being special;
569          * the last character may be '-'.
570          */
571         v = 1 - v;
572         for (;;) {
573                 tab[c] = v;             /* take character c */
574 doswitch:
575                 n = *fmt++;             /* and examine the next */
576                 switch (n) {
577
578                 case 0:                 /* format ended too soon */
579                         return (fmt - 1);
580
581                 case '-':
582                         /*
583                          * A scanset of the form
584                          *      [01+-]
585                          * is defined as `the digit 0, the digit 1,
586                          * the character +, the character -', but
587                          * the effect of a scanset such as
588                          *      [a-zA-Z0-9]
589                          * is implementation defined.  The V7 Unix
590                          * scanf treats `a-z' as `the letters a through
591                          * z', but treats `a-a' as `the letter a, the
592                          * character -, and the letter a'.
593                          *
594                          * For compatibility, the `-' is not considerd
595                          * to define a range if the character following
596                          * it is either a close bracket (required by ANSI)
597                          * or is not numerically greater than the character
598                          * we just stored in the table (c).
599                          */
600                         n = *fmt;
601                         if (n == ']' || n < c) {
602                                 c = '-';
603                                 break;  /* resume the for(;;) */
604                         }
605                         fmt++;
606                         /* fill in the range */
607                         do {
608                             tab[++c] = v;
609                         } while (c < n);
610                         c = n;
611                         /*
612                          * Alas, the V7 Unix scanf also treats formats
613                          * such as [a-c-e] as `the letters a through e'.
614                          * This too is permitted by the standard....
615                          */
616                         goto doswitch;
617                         break;
618
619                 case ']':               /* end of scanset */
620                         return (fmt);
621
622                 default:                /* just another character */
623                         c = n;
624                         break;
625                 }
626         }
627         /* NOTREACHED */
628 }
629