xref: /freebsd/contrib/tcpdump/missing/snprintf.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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 #if 0
71 static int
72 as_reserve (struct state *state, size_t n)
73 {
74   if (state->s + n > state->theend) {
75     int off = state->s - state->str;
76     unsigned char *tmp;
77 
78     if (state->max_sz && state->sz >= state->max_sz)
79       return 1;
80 
81     state->sz = max(state->sz * 2, state->sz + n);
82     if (state->max_sz)
83       state->sz = min(state->sz, state->max_sz);
84     tmp = realloc (state->str, state->sz);
85     if (tmp == NULL)
86       return 1;
87     state->str = tmp;
88     state->s = state->str + off;
89     state->theend = state->str + state->sz - 1;
90   }
91   return 0;
92 }
93 
94 static int
95 as_append_char (struct state *state, unsigned char c)
96 {
97   if(as_reserve (state, 1))
98     return 1;
99   else {
100     *state->s++ = c;
101     return 0;
102   }
103 }
104 #endif
105 
106 static int
107 append_number(struct state *state,
108 	      unsigned long num, unsigned base, char *rep,
109 	      int width, int prec, int flags, int minusp)
110 {
111   int len = 0;
112   int i;
113 
114   /* given precision, ignore zero flag */
115   if(prec != -1)
116     flags &= ~zero_flag;
117   else
118     prec = 1;
119   /* zero value with zero precision -> "" */
120   if(prec == 0 && num == 0)
121     return 0;
122   do{
123     if((*state->append_char)(state, rep[num % base]))
124       return 1;
125     len++;
126     num /= base;
127   }while(num);
128   prec -= len;
129   /* pad with prec zeros */
130   while(prec-- > 0){
131     if((*state->append_char)(state, '0'))
132       return 1;
133     len++;
134   }
135   /* add length of alternate prefix (added later) to len */
136   if(flags & alternate_flag && (base == 16 || base == 8))
137     len += base / 8;
138   /* pad with zeros */
139   if(flags & zero_flag){
140     width -= len;
141     if(minusp || (flags & space_flag) || (flags & plus_flag))
142       width--;
143     while(width-- > 0){
144       if((*state->append_char)(state, '0'))
145 	return 1;
146       len++;
147     }
148   }
149   /* add alternate prefix */
150   if(flags & alternate_flag && (base == 16 || base == 8)){
151     if(base == 16)
152       if((*state->append_char)(state, rep[10] + 23)) /* XXX */
153 	return 1;
154     if((*state->append_char)(state, '0'))
155       return 1;
156   }
157   /* add sign */
158   if(minusp){
159     if((*state->append_char)(state, '-'))
160       return 1;
161     len++;
162   } else if(flags & plus_flag) {
163     if((*state->append_char)(state, '+'))
164       return 1;
165     len++;
166   } else if(flags & space_flag) {
167     if((*state->append_char)(state, ' '))
168       return 1;
169     len++;
170   }
171   if(flags & minus_flag)
172     /* swap before padding with spaces */
173     for(i = 0; i < len / 2; i++){
174       char c = state->s[-i-1];
175       state->s[-i-1] = state->s[-len+i];
176       state->s[-len+i] = c;
177     }
178   width -= len;
179   while(width-- > 0){
180     if((*state->append_char)(state,  ' '))
181       return 1;
182     len++;
183   }
184   if(!(flags & minus_flag))
185     /* swap after padding with spaces */
186     for(i = 0; i < len / 2; i++){
187       char c = state->s[-i-1];
188       state->s[-i-1] = state->s[-len+i];
189       state->s[-len+i] = c;
190     }
191 
192   return 0;
193 }
194 
195 static int
196 append_string (struct state *state,
197 	       unsigned char *arg,
198 	       int width,
199 	       int prec,
200 	       int flags)
201 {
202   if(prec != -1)
203     width -= prec;
204   else
205     width -= strlen((char *)arg);
206   if(!(flags & minus_flag))
207     while(width-- > 0)
208       if((*state->append_char) (state, ' '))
209 	return 1;
210   if (prec != -1) {
211     while (*arg && prec--)
212       if ((*state->append_char) (state, *arg++))
213 	return 1;
214   } else {
215     while (*arg)
216       if ((*state->append_char) (state, *arg++))
217 	return 1;
218   }
219   if(flags & minus_flag)
220     while(width-- > 0)
221       if((*state->append_char) (state, ' '))
222 	return 1;
223   return 0;
224 }
225 
226 static int
227 append_char(struct state *state,
228 	    unsigned char arg,
229 	    int width,
230 	    int flags)
231 {
232   while(!(flags & minus_flag) && --width > 0)
233     if((*state->append_char) (state, ' '))
234       return 1;
235 
236   if((*state->append_char) (state, arg))
237     return 1;
238   while((flags & minus_flag) && --width > 0)
239     if((*state->append_char) (state, ' '))
240       return 1;
241 
242   return 0;
243 }
244 
245 /*
246  * This can't be made into a function...
247  */
248 
249 #define PARSE_INT_FORMAT(res, arg, unsig) \
250 if (long_flag) \
251      res = (unsig long)va_arg(arg, unsig long); \
252 else if (short_flag) \
253      res = (unsig short)va_arg(arg, unsig int); \
254 else \
255      res = (unsig int)va_arg(arg, unsig int)
256 
257 /*
258  * zyxprintf - return 0 or -1
259  */
260 
261 static int
262 xyzprintf (struct state *state, const char *char_format, va_list ap)
263 {
264   const unsigned char *format = (const unsigned char *)char_format;
265   unsigned char c;
266 
267   while((c = *format++)) {
268     if (c == '%') {
269       int flags      = 0;
270       int width      = 0;
271       int prec       = -1;
272       int long_flag  = 0;
273       int short_flag = 0;
274 
275       /* flags */
276       while((c = *format++)){
277 	if(c == '-')
278 	  flags |= minus_flag;
279 	else if(c == '+')
280 	  flags |= plus_flag;
281 	else if(c == ' ')
282 	  flags |= space_flag;
283 	else if(c == '#')
284 	  flags |= alternate_flag;
285 	else if(c == '0')
286 	  flags |= zero_flag;
287 	else
288 	  break;
289       }
290 
291       if((flags & space_flag) && (flags & plus_flag))
292 	flags ^= space_flag;
293 
294       if((flags & minus_flag) && (flags & zero_flag))
295 	flags ^= zero_flag;
296 
297       /* width */
298       if (isdigit(c))
299 	do {
300 	  width = width * 10 + c - '0';
301 	  c = *format++;
302 	} while(isdigit(c));
303       else if(c == '*') {
304 	width = va_arg(ap, int);
305 	c = *format++;
306       }
307 
308       /* precision */
309       if (c == '.') {
310 	prec = 0;
311 	c = *format++;
312 	if (isdigit(c))
313 	  do {
314 	    prec = prec * 10 + c - '0';
315 	    c = *format++;
316 	  } while(isdigit(c));
317 	else if (c == '*') {
318 	  prec = va_arg(ap, int);
319 	  c = *format++;
320 	}
321       }
322 
323       /* size */
324 
325       if (c == 'h') {
326 	short_flag = 1;
327 	c = *format++;
328       } else if (c == 'l') {
329 	long_flag = 1;
330 	c = *format++;
331       }
332 
333       switch (c) {
334       case 'c' :
335 	if(append_char(state, va_arg(ap, int), width, flags))
336 	  return -1;
337 	break;
338       case 's' :
339 	if (append_string(state,
340 			  va_arg(ap, unsigned char*),
341 			  width,
342 			  prec,
343 			  flags))
344 	  return -1;
345 	break;
346       case 'd' :
347       case 'i' : {
348 	long arg;
349 	unsigned long num;
350 	int minusp = 0;
351 
352 	PARSE_INT_FORMAT(arg, ap, signed);
353 
354 	if (arg < 0) {
355 	  minusp = 1;
356 	  num = -arg;
357 	} else
358 	  num = arg;
359 
360 	if (append_number (state, num, 10, "0123456789",
361 			   width, prec, flags, minusp))
362 	  return -1;
363 	break;
364       }
365       case 'u' : {
366 	unsigned long arg;
367 
368 	PARSE_INT_FORMAT(arg, ap, unsigned);
369 
370 	if (append_number (state, arg, 10, "0123456789",
371 			   width, prec, flags, 0))
372 	  return -1;
373 	break;
374       }
375       case 'o' : {
376 	unsigned long arg;
377 
378 	PARSE_INT_FORMAT(arg, ap, unsigned);
379 
380 	if (append_number (state, arg, 010, "01234567",
381 			   width, prec, flags, 0))
382 	  return -1;
383 	break;
384       }
385       case 'x' : {
386 	unsigned long arg;
387 
388 	PARSE_INT_FORMAT(arg, ap, unsigned);
389 
390 	if (append_number (state, arg, 0x10, "0123456789abcdef",
391 			   width, prec, flags, 0))
392 	  return -1;
393 	break;
394       }
395       case 'X' :{
396 	unsigned long arg;
397 
398 	PARSE_INT_FORMAT(arg, ap, unsigned);
399 
400 	if (append_number (state, arg, 0x10, "0123456789ABCDEF",
401 			   width, prec, flags, 0))
402 	  return -1;
403 	break;
404       }
405       case 'p' : {
406 	unsigned long arg = (unsigned long)va_arg(ap, void*);
407 
408 	if (append_number (state, arg, 0x10, "0123456789ABCDEF",
409 			   width, prec, flags, 0))
410 	  return -1;
411 	break;
412       }
413       case 'n' : {
414 	int *arg = va_arg(ap, int *);
415 	*arg = state->s - state->str;
416 	break;
417       }
418       case '\0' :
419 	  --format;
420 	  /* FALLTHROUGH */
421       case '%' :
422 	if ((*state->append_char)(state, c))
423 	  return -1;
424 	break;
425       default :
426 	if (   (*state->append_char)(state, '%')
427 	    || (*state->append_char)(state, c))
428 	  return -1;
429 	break;
430       }
431     } else
432       if ((*state->append_char) (state, c))
433 	return -1;
434   }
435   return 0;
436 }
437 
438 #if 0
439 #ifndef HAVE_ASPRINTF
440 int
441 asprintf (char **ret, const char *format, ...)
442 {
443   va_list args;
444   int val;
445 
446   va_start(args, format);
447   val = vasprintf (ret, format, args);
448 
449 #ifdef PARANOIA
450   {
451     int ret2;
452     char *tmp;
453     tmp = malloc (val + 1);
454     if (tmp == NULL)
455       abort ();
456 
457     ret2 = vsprintf (tmp, format, args);
458     if (val != ret2 || strcmp(*ret, tmp))
459       abort ();
460     free (tmp);
461   }
462 #endif
463 
464   va_end(args);
465   return val;
466 }
467 #endif
468 
469 #ifndef HAVE_VASNPRINTF
470 int
471 nd_vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
472 {
473   int st;
474   size_t len;
475   struct state state;
476 
477   state.max_sz = max_sz;
478   state.sz     = 1;
479   state.str    = malloc(state.sz);
480   if (state.str == NULL) {
481     *ret = NULL;
482     return -1;
483   }
484   state.s = state.str;
485   state.theend = state.s + state.sz - 1;
486   state.append_char = as_append_char;
487   state.reserve     = as_reserve;
488 
489   st = xyzprintf (&state, format, args);
490   if (st) {
491     free (state.str);
492     *ret = NULL;
493     return -1;
494   } else {
495     char *tmp;
496 
497     *state.s = '\0';
498     len = state.s - state.str;
499     tmp = realloc (state.str, len+1);
500     if (tmp == NULL) {
501       free (state.str);
502       *ret = NULL;
503       return -1;
504     }
505     *ret = tmp;
506     return len;
507   }
508 }
509 #endif
510 #endif
511