xref: /freebsd/contrib/tcpdump/missing/snprintf.c (revision 1c05a6ea6b849ff95e539c31adea887c644a6a01)
1 /*
2  * Copyright (c) 1995-1999 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
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  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifdef HAVE_CONFIG_H
35 #include <config.h>
36 #endif
37 
38 #include <stdio.h>
39 #include <stdarg.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <ctype.h>
43 #include <sys/types.h>
44 
45 #include "netdissect.h"
46 
47 enum format_flags {
48     minus_flag     =  1,
49     plus_flag      =  2,
50     space_flag     =  4,
51     alternate_flag =  8,
52     zero_flag      = 16
53 };
54 
55 /*
56  * Common state
57  */
58 
59 struct state {
60   unsigned char *str;
61   unsigned char *s;
62   unsigned char *theend;
63   size_t sz;
64   size_t max_sz;
65   int (*append_char)(struct state *, unsigned char);
66   int (*reserve)(struct state *, size_t);
67   /* XXX - methods */
68 };
69 
70 #ifndef HAVE_VSNPRINTF
71 static int
72 sn_reserve (struct state *state, size_t n)
73 {
74   return state->s + n > state->theend;
75 }
76 
77 static int
78 sn_append_char (struct state *state, unsigned char c)
79 {
80   if (sn_reserve (state, 1)) {
81     return 1;
82   } else {
83     *state->s++ = c;
84     return 0;
85   }
86 }
87 #endif
88 
89 #if 0
90 static int
91 as_reserve (struct state *state, size_t n)
92 {
93   if (state->s + n > state->theend) {
94     int off = state->s - state->str;
95     unsigned char *tmp;
96 
97     if (state->max_sz && state->sz >= state->max_sz)
98       return 1;
99 
100     state->sz = max(state->sz * 2, state->sz + n);
101     if (state->max_sz)
102       state->sz = min(state->sz, state->max_sz);
103     tmp = realloc (state->str, state->sz);
104     if (tmp == NULL)
105       return 1;
106     state->str = tmp;
107     state->s = state->str + off;
108     state->theend = state->str + state->sz - 1;
109   }
110   return 0;
111 }
112 
113 static int
114 as_append_char (struct state *state, unsigned char c)
115 {
116   if(as_reserve (state, 1))
117     return 1;
118   else {
119     *state->s++ = c;
120     return 0;
121   }
122 }
123 #endif
124 
125 static int
126 append_number(struct state *state,
127 	      unsigned long num, unsigned base, char *rep,
128 	      int width, int prec, int flags, int minusp)
129 {
130   int len = 0;
131   int i;
132 
133   /* given precision, ignore zero flag */
134   if(prec != -1)
135     flags &= ~zero_flag;
136   else
137     prec = 1;
138   /* zero value with zero precision -> "" */
139   if(prec == 0 && num == 0)
140     return 0;
141   do{
142     if((*state->append_char)(state, rep[num % base]))
143       return 1;
144     len++;
145     num /= base;
146   }while(num);
147   prec -= len;
148   /* pad with prec zeros */
149   while(prec-- > 0){
150     if((*state->append_char)(state, '0'))
151       return 1;
152     len++;
153   }
154   /* add length of alternate prefix (added later) to len */
155   if(flags & alternate_flag && (base == 16 || base == 8))
156     len += base / 8;
157   /* pad with zeros */
158   if(flags & zero_flag){
159     width -= len;
160     if(minusp || (flags & space_flag) || (flags & plus_flag))
161       width--;
162     while(width-- > 0){
163       if((*state->append_char)(state, '0'))
164 	return 1;
165       len++;
166     }
167   }
168   /* add alternate prefix */
169   if(flags & alternate_flag && (base == 16 || base == 8)){
170     if(base == 16)
171       if((*state->append_char)(state, rep[10] + 23)) /* XXX */
172 	return 1;
173     if((*state->append_char)(state, '0'))
174       return 1;
175   }
176   /* add sign */
177   if(minusp){
178     if((*state->append_char)(state, '-'))
179       return 1;
180     len++;
181   } else if(flags & plus_flag) {
182     if((*state->append_char)(state, '+'))
183       return 1;
184     len++;
185   } else if(flags & space_flag) {
186     if((*state->append_char)(state, ' '))
187       return 1;
188     len++;
189   }
190   if(flags & minus_flag)
191     /* swap before padding with spaces */
192     for(i = 0; i < len / 2; i++){
193       char c = state->s[-i-1];
194       state->s[-i-1] = state->s[-len+i];
195       state->s[-len+i] = c;
196     }
197   width -= len;
198   while(width-- > 0){
199     if((*state->append_char)(state,  ' '))
200       return 1;
201     len++;
202   }
203   if(!(flags & minus_flag))
204     /* swap after padding with spaces */
205     for(i = 0; i < len / 2; i++){
206       char c = state->s[-i-1];
207       state->s[-i-1] = state->s[-len+i];
208       state->s[-len+i] = c;
209     }
210 
211   return 0;
212 }
213 
214 static int
215 append_string (struct state *state,
216 	       unsigned char *arg,
217 	       int width,
218 	       int prec,
219 	       int flags)
220 {
221   if(prec != -1)
222     width -= prec;
223   else
224     width -= strlen((char *)arg);
225   if(!(flags & minus_flag))
226     while(width-- > 0)
227       if((*state->append_char) (state, ' '))
228 	return 1;
229   if (prec != -1) {
230     while (*arg && prec--)
231       if ((*state->append_char) (state, *arg++))
232 	return 1;
233   } else {
234     while (*arg)
235       if ((*state->append_char) (state, *arg++))
236 	return 1;
237   }
238   if(flags & minus_flag)
239     while(width-- > 0)
240       if((*state->append_char) (state, ' '))
241 	return 1;
242   return 0;
243 }
244 
245 static int
246 append_char(struct state *state,
247 	    unsigned char arg,
248 	    int width,
249 	    int flags)
250 {
251   while(!(flags & minus_flag) && --width > 0)
252     if((*state->append_char) (state, ' '))
253       return 1;
254 
255   if((*state->append_char) (state, arg))
256     return 1;
257   while((flags & minus_flag) && --width > 0)
258     if((*state->append_char) (state, ' '))
259       return 1;
260 
261   return 0;
262 }
263 
264 /*
265  * This can't be made into a function...
266  */
267 
268 #define PARSE_INT_FORMAT(res, arg, unsig) \
269 if (long_flag) \
270      res = (unsig long)va_arg(arg, unsig long); \
271 else if (short_flag) \
272      res = (unsig short)va_arg(arg, unsig int); \
273 else \
274      res = (unsig int)va_arg(arg, unsig int)
275 
276 /*
277  * zyxprintf - return 0 or -1
278  */
279 
280 static int
281 xyzprintf (struct state *state, const char *char_format, va_list ap)
282 {
283   const unsigned char *format = (const unsigned char *)char_format;
284   unsigned char c;
285 
286   while((c = *format++)) {
287     if (c == '%') {
288       int flags      = 0;
289       int width      = 0;
290       int prec       = -1;
291       int long_flag  = 0;
292       int short_flag = 0;
293 
294       /* flags */
295       while((c = *format++)){
296 	if(c == '-')
297 	  flags |= minus_flag;
298 	else if(c == '+')
299 	  flags |= plus_flag;
300 	else if(c == ' ')
301 	  flags |= space_flag;
302 	else if(c == '#')
303 	  flags |= alternate_flag;
304 	else if(c == '0')
305 	  flags |= zero_flag;
306 	else
307 	  break;
308       }
309 
310       if((flags & space_flag) && (flags & plus_flag))
311 	flags ^= space_flag;
312 
313       if((flags & minus_flag) && (flags & zero_flag))
314 	flags ^= zero_flag;
315 
316       /* width */
317       if (isdigit(c))
318 	do {
319 	  width = width * 10 + c - '0';
320 	  c = *format++;
321 	} while(isdigit(c));
322       else if(c == '*') {
323 	width = va_arg(ap, int);
324 	c = *format++;
325       }
326 
327       /* precision */
328       if (c == '.') {
329 	prec = 0;
330 	c = *format++;
331 	if (isdigit(c))
332 	  do {
333 	    prec = prec * 10 + c - '0';
334 	    c = *format++;
335 	  } while(isdigit(c));
336 	else if (c == '*') {
337 	  prec = va_arg(ap, int);
338 	  c = *format++;
339 	}
340       }
341 
342       /* size */
343 
344       if (c == 'h') {
345 	short_flag = 1;
346 	c = *format++;
347       } else if (c == 'l') {
348 	long_flag = 1;
349 	c = *format++;
350       }
351 
352       switch (c) {
353       case 'c' :
354 	if(append_char(state, va_arg(ap, int), width, flags))
355 	  return -1;
356 	break;
357       case 's' :
358 	if (append_string(state,
359 			  va_arg(ap, unsigned char*),
360 			  width,
361 			  prec,
362 			  flags))
363 	  return -1;
364 	break;
365       case 'd' :
366       case 'i' : {
367 	long arg;
368 	unsigned long num;
369 	int minusp = 0;
370 
371 	PARSE_INT_FORMAT(arg, ap, signed);
372 
373 	if (arg < 0) {
374 	  minusp = 1;
375 	  num = -arg;
376 	} else
377 	  num = arg;
378 
379 	if (append_number (state, num, 10, "0123456789",
380 			   width, prec, flags, minusp))
381 	  return -1;
382 	break;
383       }
384       case 'u' : {
385 	unsigned long arg;
386 
387 	PARSE_INT_FORMAT(arg, ap, unsigned);
388 
389 	if (append_number (state, arg, 10, "0123456789",
390 			   width, prec, flags, 0))
391 	  return -1;
392 	break;
393       }
394       case 'o' : {
395 	unsigned long arg;
396 
397 	PARSE_INT_FORMAT(arg, ap, unsigned);
398 
399 	if (append_number (state, arg, 010, "01234567",
400 			   width, prec, flags, 0))
401 	  return -1;
402 	break;
403       }
404       case 'x' : {
405 	unsigned long arg;
406 
407 	PARSE_INT_FORMAT(arg, ap, unsigned);
408 
409 	if (append_number (state, arg, 0x10, "0123456789abcdef",
410 			   width, prec, flags, 0))
411 	  return -1;
412 	break;
413       }
414       case 'X' :{
415 	unsigned long arg;
416 
417 	PARSE_INT_FORMAT(arg, ap, unsigned);
418 
419 	if (append_number (state, arg, 0x10, "0123456789ABCDEF",
420 			   width, prec, flags, 0))
421 	  return -1;
422 	break;
423       }
424       case 'p' : {
425 	unsigned long arg = (unsigned long)va_arg(ap, void*);
426 
427 	if (append_number (state, arg, 0x10, "0123456789ABCDEF",
428 			   width, prec, flags, 0))
429 	  return -1;
430 	break;
431       }
432       case 'n' : {
433 	int *arg = va_arg(ap, int*);
434 	*arg = state->s - state->str;
435 	break;
436       }
437       case '\0' :
438 	  --format;
439 	  /* FALLTHROUGH */
440       case '%' :
441 	if ((*state->append_char)(state, c))
442 	  return -1;
443 	break;
444       default :
445 	if (   (*state->append_char)(state, '%')
446 	    || (*state->append_char)(state, c))
447 	  return -1;
448 	break;
449       }
450     } else
451       if ((*state->append_char) (state, c))
452 	return -1;
453   }
454   return 0;
455 }
456 
457 #ifndef HAVE_SNPRINTF
458 int
459 snprintf (char *str, size_t sz, const char *format, ...)
460 {
461   va_list args;
462   int ret;
463 
464   va_start(args, format);
465   ret = vsnprintf (str, sz, format, args);
466 
467 #ifdef PARANOIA
468   {
469     int ret2;
470     char *tmp;
471 
472     tmp = malloc (sz);
473     if (tmp == NULL)
474       abort ();
475 
476     ret2 = vsprintf (tmp, format, args);
477     if (ret != ret2 || strcmp(str, tmp))
478       abort ();
479     free (tmp);
480   }
481 #endif
482 
483   va_end(args);
484   return ret;
485 }
486 #endif
487 
488 #if 0
489 #ifndef HAVE_ASPRINTF
490 int
491 asprintf (char **ret, const char *format, ...)
492 {
493   va_list args;
494   int val;
495 
496   va_start(args, format);
497   val = vasprintf (ret, format, args);
498 
499 #ifdef PARANOIA
500   {
501     int ret2;
502     char *tmp;
503     tmp = malloc (val + 1);
504     if (tmp == NULL)
505       abort ();
506 
507     ret2 = vsprintf (tmp, format, args);
508     if (val != ret2 || strcmp(*ret, tmp))
509       abort ();
510     free (tmp);
511   }
512 #endif
513 
514   va_end(args);
515   return val;
516 }
517 #endif
518 
519 #ifndef HAVE_ASNPRINTF
520 int
521 asnprintf (char **ret, size_t max_sz, const char *format, ...)
522 {
523   va_list args;
524   int val;
525 
526   va_start(args, format);
527   val = vasnprintf (ret, max_sz, format, args);
528 
529 #ifdef PARANOIA
530   {
531     int ret2;
532     char *tmp;
533     tmp = malloc (val + 1);
534     if (tmp == NULL)
535       abort ();
536 
537     ret2 = vsprintf (tmp, format, args);
538     if (val != ret2 || strcmp(*ret, tmp))
539       abort ();
540     free (tmp);
541   }
542 #endif
543 
544   va_end(args);
545   return val;
546 }
547 #endif
548 
549 #ifndef HAVE_VASPRINTF
550 int
551 vasprintf (char **ret, const char *format, va_list args)
552 {
553   return vasnprintf (ret, 0, format, args);
554 }
555 #endif
556 
557 
558 #ifndef HAVE_VASNPRINTF
559 int
560 vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
561 {
562   int st;
563   size_t len;
564   struct state state;
565 
566   state.max_sz = max_sz;
567   state.sz     = 1;
568   state.str    = malloc(state.sz);
569   if (state.str == NULL) {
570     *ret = NULL;
571     return -1;
572   }
573   state.s = state.str;
574   state.theend = state.s + state.sz - 1;
575   state.append_char = as_append_char;
576   state.reserve     = as_reserve;
577 
578   st = xyzprintf (&state, format, args);
579   if (st) {
580     free (state.str);
581     *ret = NULL;
582     return -1;
583   } else {
584     char *tmp;
585 
586     *state.s = '\0';
587     len = state.s - state.str;
588     tmp = realloc (state.str, len+1);
589     if (tmp == NULL) {
590       free (state.str);
591       *ret = NULL;
592       return -1;
593     }
594     *ret = tmp;
595     return len;
596   }
597 }
598 #endif
599 #endif
600 
601 #ifndef HAVE_VSNPRINTF
602 int
603 vsnprintf (char *str, size_t sz, const char *format, va_list args)
604 {
605   struct state state;
606   int ret;
607   unsigned char *ustr = (unsigned char *)str;
608 
609   state.max_sz = 0;
610   state.sz     = sz;
611   state.str    = ustr;
612   state.s      = ustr;
613   state.theend = ustr + sz - 1;
614   state.append_char = sn_append_char;
615   state.reserve     = sn_reserve;
616 
617   ret = xyzprintf (&state, format, args);
618   *state.s = '\0';
619   if (ret)
620     return sz;
621   else
622     return state.s - state.str;
623 }
624 #endif
625 
626