1 /*        $NetBSD: xprintf.c,v 1.23 2021/03/06 20:09:39 christos Exp $           */
2 
3 /*
4  * Copyright 1996 Matt Thomas <matt@3am-software.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __RCSID("$NetBSD: xprintf.c,v 1.23 2021/03/06 20:09:39 christos Exp $");
33 #endif /* not lint */
34 
35 #include <string.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include <errno.h>
39 #include <stdarg.h>
40 
41 #include "rtldenv.h"
42 
43 #ifdef RTLD_LOADER
44 #define   SZ_LONG             0x01
45 #define   SZ_UNSIGNED         0x02
46 #define SZ_SIZE_T   0x04
47 
48 /*
49  * Non-mallocing printf, for use by malloc and rtld itself.
50  * This avoids putting in most of stdio.
51  *
52  * deals with formats %x, %p, %s, and %d.
53  */
54 size_t
xvsnprintf(char * buf,size_t buflen,const char * fmt,va_list ap)55 xvsnprintf(char *buf, size_t buflen, const char *fmt, va_list ap)
56 {
57           char *bp = buf;
58           char *const ep = buf + buflen - 4;
59           int size, prec;
60 
61           while (*fmt != '\0' && bp < ep) {
62                     switch (*fmt) {
63                     case '\\':{
64                               if (fmt[1] != '\0')
65                                         *bp++ = *++fmt;
66                               continue;
67                     }
68                     case '%':{
69                               size = 0;
70                               prec = -1;
71           rflag:              switch (fmt[1]) {
72                               case '*':
73                                         prec = va_arg(ap, int);
74                                         /* FALLTHROUGH */
75                               case '.':
76                               case '#':
77                                         fmt++;
78                                         goto rflag;
79                               case 'l':
80                               case 'j':
81                                         size |= SZ_LONG;
82                                         fmt++;
83                                         goto rflag;
84                               case 'z':
85                                         size |= SZ_SIZE_T;
86                                         fmt++;
87                                         goto rflag;
88                               case 'u':
89                                         size |= SZ_UNSIGNED;
90                                         /* FALLTHROUGH */
91                               case 'd':{
92                                         long sval;
93                                         unsigned long uval;
94                                         char digits[sizeof(int) * 3], *dp = digits;
95 #define   SARG() \
96 (size & SZ_LONG ? va_arg(ap, long) : \
97 ((size & SZ_SIZE_T ? (long)va_arg(ap, size_t) : \
98 va_arg(ap, int))))
99 #define   UARG() \
100 (size & SZ_LONG ? va_arg(ap, unsigned long) : \
101 ((size & SZ_SIZE_T ? va_arg(ap, size_t) : \
102 va_arg(ap, unsigned int))))
103 
104                                         if (fmt[1] == 'd') {
105                                                   if (size & SZ_UNSIGNED)
106                                                             sval = UARG();
107                                                   else
108                                                             sval = SARG();
109                                                   if (sval < 0) {
110                                                             if ((sval << 1) == 0) {
111                                                                       /*
112                                                                        * We can't flip the
113                                                                        * sign of this since
114                                                                        * it can't be
115                                                                        * represented as a
116                                                                        * positive number in
117                                                                        * two complement,
118                                                                        * handle the first
119                                                                        * digit. After that,
120                                                                        * it can be flipped
121                                                                        * since it is now not
122                                                                        * 2^(n-1).
123                                                                        */
124                                                                       *dp++ = '0'-(sval % 10);
125                                                                       sval /= 10;
126                                                             }
127                                                             *bp++ = '-';
128                                                             uval = -sval;
129                                                   } else {
130                                                             uval = sval;
131                                                   }
132                                         } else {
133                                                   if (size & SZ_UNSIGNED)
134                                                             uval = UARG();
135                                                   else
136                                                             uval = SARG();
137                                         }
138                                         do {
139                                                   *dp++ = '0' + (uval % 10);
140                                                   uval /= 10;
141                                         } while (uval != 0);
142                                         do {
143                                                   *bp++ = *--dp;
144                                         } while (dp != digits && bp < ep);
145                                         fmt += 2;
146                                         break;
147                               }
148                               case 'x':
149                               case 'p':{
150                                         unsigned long val = va_arg(ap, unsigned long);
151                                         unsigned long mask = ~(~0UL >> 4);
152                                         int bits = sizeof(val) * 8 - 4;
153                                         const char hexdigits[] = "0123456789abcdef";
154                                         if (fmt[1] == 'p') {
155                                                   *bp++ = '0';
156                                                   *bp++ = 'x';
157                                         }
158                                         /* handle the border case */
159                                         if (val == 0) {
160                                                   *bp++ = '0';
161                                                   fmt += 2;
162                                                   break;
163                                         }
164                                         /* suppress 0s */
165                                         while ((val & mask) == 0)
166                                                   bits -= 4, mask >>= 4;
167 
168                                         /* emit the hex digits */
169                                         while (bits >= 0 && bp < ep) {
170                                                   *bp++ = hexdigits[(val & mask) >> bits];
171                                                   bits -= 4, mask >>= 4;
172                                         }
173                                         fmt += 2;
174                                         break;
175                               }
176                               case 's':{
177                                         const char *str = va_arg(ap, const char *);
178                                         int len;
179 
180                                         if (str == NULL)
181                                                   str = "(null)";
182 
183                                         if (prec < 0)
184                                                   len = strlen(str);
185                                         else
186                                                   len = prec;
187                                         if (ep - bp < len)
188                                                   len = ep - bp;
189                                         memcpy(bp, str, len);
190                                         bp += len;
191                                         fmt += 2;
192                                         break;
193                               }
194                               case 'c':{
195                                         int c = va_arg(ap, int);
196                                         *bp++ = (char)c;
197                                         fmt += 2;
198                                         break;
199                               }
200                               default:
201                                         *bp++ = *fmt;
202                                         break;
203                               }
204                               break;
205                     }
206                     default:
207                               *bp++ = *fmt++;
208                               break;
209                     }
210           }
211 
212           *bp = '\0';
213           return bp - buf;
214 }
215 
216 void
xvprintf(const char * fmt,va_list ap)217 xvprintf(const char *fmt, va_list ap)
218 {
219           char buf[256];
220 
221           (void) write(2, buf, xvsnprintf(buf, sizeof(buf), fmt, ap));
222 }
223 
224 void
xprintf(const char * fmt,...)225 xprintf(const char *fmt, ...)
226 {
227           va_list ap;
228 
229           va_start(ap, fmt);
230 
231           xvprintf(fmt, ap);
232 
233           va_end(ap);
234 }
235 
236 void
xsnprintf(char * buf,size_t buflen,const char * fmt,...)237 xsnprintf(char *buf, size_t buflen, const char *fmt, ...)
238 {
239           va_list ap;
240 
241           va_start(ap, fmt);
242 
243           xvsnprintf(buf, buflen, fmt, ap);
244 
245           va_end(ap);
246 }
247 
248 #include "errlist_concat.h"
249 
250 const char *
xstrerror(int error)251 xstrerror(int error)
252 {
253 
254           if (error >= concat_nerr || error < 0) {
255                     static char buf[128];
256                     xsnprintf(buf, sizeof(buf), "Unknown error: %d", error);
257                     return buf;
258           }
259           return concat_errlist + concat_offset[error];
260 }
261 
262 void
xerrx(int eval,const char * fmt,...)263 xerrx(int eval, const char *fmt, ...)
264 {
265           va_list ap;
266 
267           va_start(ap, fmt);
268           xvprintf(fmt, ap);
269           va_end(ap);
270           (void) write(2, "\n", 1);
271 
272           exit(eval);
273 }
274 
275 void
xerr(int eval,const char * fmt,...)276 xerr(int eval, const char *fmt, ...)
277 {
278           int saved_errno = errno;
279           va_list ap;
280 
281           va_start(ap, fmt);
282           xvprintf(fmt, ap);
283           va_end(ap);
284 
285           xprintf(": %s\n", xstrerror(saved_errno));
286           exit(eval);
287 }
288 
289 void
xwarn(const char * fmt,...)290 xwarn(const char *fmt, ...)
291 {
292           int saved_errno = errno;
293           va_list ap;
294 
295           va_start(ap, fmt);
296           xvprintf(fmt, ap);
297           va_end(ap);
298 
299           xprintf(": %s\n", xstrerror(saved_errno));
300           errno = saved_errno;
301 }
302 
303 void
xwarnx(const char * fmt,...)304 xwarnx(const char *fmt, ...)
305 {
306           va_list ap;
307 
308           va_start(ap, fmt);
309           xvprintf(fmt, ap);
310           va_end(ap);
311           (void) write(2, "\n", 1);
312 }
313 
314 #ifdef DEBUG
315 void
xassert(const char * file,int line,const char * failedexpr)316 xassert(const char *file, int line, const char *failedexpr)
317 {
318 
319           xprintf("assertion \"%s\" failed: file \"%s\", line %d\n",
320                     failedexpr, file, line);
321           abort();
322           /* NOTREACHED */
323 }
324 #endif
325 #endif
326