xref: /freebsd/libexec/rtld-elf/rtld_printf.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1986, 1988, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * $FreeBSD$
38  */
39 
40 #include <sys/param.h>
41 #include <inttypes.h>
42 #include <stdarg.h>
43 #include <stddef.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include "rtld_printf.h"
47 #include "rtld_libc.h"
48 
49 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
50 
51 #define	PRINT_METHOD_SNPRINTF	1
52 #define	PRINT_METHOD_WRITE	2
53 
54 struct snprintf_arg {
55 	int	method;
56 	char	*str;
57 	char	*buf;
58 	size_t	remain;
59 	size_t	buf_total;
60 	int	fd;
61 };
62 
63 static void
64 printf_out(struct snprintf_arg *info)
65 {
66 
67 	if (info->remain == info->buf_total)
68 		return;
69 	write(info->fd, info->buf, info->buf_total - info->remain);
70 	info->str = info->buf;
71 	info->remain = info->buf_total;
72 }
73 
74 static void
75 snprintf_func(int ch, struct snprintf_arg *const info)
76 {
77 
78 	switch (info->method) {
79 	case PRINT_METHOD_SNPRINTF:
80 		if (info->remain >= 2) {
81 			*info->str++ = ch;
82 			info->remain--;
83 		}
84 		break;
85 	case PRINT_METHOD_WRITE:
86 		if (info->remain > 0) {
87 			*info->str++ = ch;
88 			info->remain--;
89 		} else
90 			printf_out(info);
91 		break;
92 	}
93 }
94 
95 static char const hex2ascii_lower[] = "0123456789abcdefghijklmnopqrstuvwxyz";
96 static char const hex2ascii_upper[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
97 #define	hex2ascii(hex)	(hex2ascii_lower[hex])
98 #define	hex2ascii_upper(hex)	(hex2ascii_upper[hex])
99 
100 static __inline int
101 imax(int a, int b)
102 {
103 
104 	return (a > b ? a : b);
105 }
106 
107 static char *
108 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
109 {
110 	char *p, c;
111 
112 	p = nbuf;
113 	*p = '\0';
114 	do {
115 		c = upper ? hex2ascii_upper(num % base) :
116 		    hex2ascii(num % base);
117 		*++p = c;
118 	} while (num /= base);
119 	if (lenp)
120 		*lenp = p - nbuf;
121 	return (p);
122 }
123 
124 static int
125 kvprintf(char const *fmt, struct snprintf_arg *arg, int radix, va_list ap)
126 {
127 #define PCHAR(c) snprintf_func((c), arg)
128 	char nbuf[MAXNBUF];
129 	const char *p, *percent, *q;
130 	u_char *up;
131 	int ch, n;
132 	uintmax_t num;
133 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
134 	int cflag, hflag, jflag, tflag, zflag;
135 	int dwidth, upper;
136 	char padc;
137 	int stop = 0, retval = 0;
138 
139 	num = 0;
140 
141 	if (fmt == NULL)
142 		fmt = "(fmt null)\n";
143 
144 	if (radix < 2 || radix > 36)
145 		radix = 10;
146 
147 	for (;;) {
148 		padc = ' ';
149 		width = 0;
150 		while ((ch = (u_char)*fmt++) != '%' || stop) {
151 			if (ch == '\0')
152 				return (retval);
153 			PCHAR(ch);
154 		}
155 		percent = fmt - 1;
156 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
157 		sign = 0; dot = 0; dwidth = 0; upper = 0;
158 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
159 reswitch:	switch (ch = (u_char)*fmt++) {
160 		case '.':
161 			dot = 1;
162 			goto reswitch;
163 		case '#':
164 			sharpflag = 1;
165 			goto reswitch;
166 		case '+':
167 			sign = 1;
168 			goto reswitch;
169 		case '-':
170 			ladjust = 1;
171 			goto reswitch;
172 		case '%':
173 			PCHAR(ch);
174 			break;
175 		case '*':
176 			if (!dot) {
177 				width = va_arg(ap, int);
178 				if (width < 0) {
179 					ladjust = !ladjust;
180 					width = -width;
181 				}
182 			} else {
183 				dwidth = va_arg(ap, int);
184 			}
185 			goto reswitch;
186 		case '0':
187 			if (!dot) {
188 				padc = '0';
189 				goto reswitch;
190 			}
191 			/* FALLTHROUGH */
192 		case '1': case '2': case '3': case '4':
193 		case '5': case '6': case '7': case '8': case '9':
194 				for (n = 0;; ++fmt) {
195 					n = n * 10 + ch - '0';
196 					ch = *fmt;
197 					if (ch < '0' || ch > '9')
198 						break;
199 				}
200 			if (dot)
201 				dwidth = n;
202 			else
203 				width = n;
204 			goto reswitch;
205 		case 'b':
206 			num = (u_int)va_arg(ap, int);
207 			p = va_arg(ap, char *);
208 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
209 				PCHAR(*q--);
210 
211 			if (num == 0)
212 				break;
213 
214 			for (tmp = 0; *p;) {
215 				n = *p++;
216 				if (num & (1 << (n - 1))) {
217 					PCHAR(tmp ? ',' : '<');
218 					for (; (n = *p) > ' '; ++p)
219 						PCHAR(n);
220 					tmp = 1;
221 				} else
222 					for (; *p > ' '; ++p)
223 						continue;
224 			}
225 			if (tmp)
226 				PCHAR('>');
227 			break;
228 		case 'c':
229 			PCHAR(va_arg(ap, int));
230 			break;
231 		case 'D':
232 			up = va_arg(ap, u_char *);
233 			p = va_arg(ap, char *);
234 			if (!width)
235 				width = 16;
236 			while(width--) {
237 				PCHAR(hex2ascii(*up >> 4));
238 				PCHAR(hex2ascii(*up & 0x0f));
239 				up++;
240 				if (width)
241 					for (q=p;*q;q++)
242 						PCHAR(*q);
243 			}
244 			break;
245 		case 'd':
246 		case 'i':
247 			base = 10;
248 			sign = 1;
249 			goto handle_sign;
250 		case 'h':
251 			if (hflag) {
252 				hflag = 0;
253 				cflag = 1;
254 			} else
255 				hflag = 1;
256 			goto reswitch;
257 		case 'j':
258 			jflag = 1;
259 			goto reswitch;
260 		case 'l':
261 			if (lflag) {
262 				lflag = 0;
263 				qflag = 1;
264 			} else
265 				lflag = 1;
266 			goto reswitch;
267 		case 'n':
268 			if (jflag)
269 				*(va_arg(ap, intmax_t *)) = retval;
270 			else if (qflag)
271 				*(va_arg(ap, quad_t *)) = retval;
272 			else if (lflag)
273 				*(va_arg(ap, long *)) = retval;
274 			else if (zflag)
275 				*(va_arg(ap, size_t *)) = retval;
276 			else if (hflag)
277 				*(va_arg(ap, short *)) = retval;
278 			else if (cflag)
279 				*(va_arg(ap, char *)) = retval;
280 			else
281 				*(va_arg(ap, int *)) = retval;
282 			break;
283 		case 'o':
284 			base = 8;
285 			goto handle_nosign;
286 		case 'p':
287 			base = 16;
288 			sharpflag = (width == 0);
289 			sign = 0;
290 			num = (uintptr_t)va_arg(ap, void *);
291 			goto number;
292 		case 'q':
293 			qflag = 1;
294 			goto reswitch;
295 		case 'r':
296 			base = radix;
297 			if (sign)
298 				goto handle_sign;
299 			goto handle_nosign;
300 		case 's':
301 			p = va_arg(ap, char *);
302 			if (p == NULL)
303 				p = "(null)";
304 			if (!dot)
305 				n = strlen (p);
306 			else
307 				for (n = 0; n < dwidth && p[n]; n++)
308 					continue;
309 
310 			width -= n;
311 
312 			if (!ladjust && width > 0)
313 				while (width--)
314 					PCHAR(padc);
315 			while (n--)
316 				PCHAR(*p++);
317 			if (ladjust && width > 0)
318 				while (width--)
319 					PCHAR(padc);
320 			break;
321 		case 't':
322 			tflag = 1;
323 			goto reswitch;
324 		case 'u':
325 			base = 10;
326 			goto handle_nosign;
327 		case 'X':
328 			upper = 1;
329 			/* FALLTHROUGH */
330 		case 'x':
331 			base = 16;
332 			goto handle_nosign;
333 		case 'y':
334 			base = 16;
335 			sign = 1;
336 			goto handle_sign;
337 		case 'z':
338 			zflag = 1;
339 			goto reswitch;
340 handle_nosign:
341 			sign = 0;
342 			if (jflag)
343 				num = va_arg(ap, uintmax_t);
344 			else if (qflag)
345 				num = va_arg(ap, u_quad_t);
346 			else if (tflag)
347 				num = va_arg(ap, ptrdiff_t);
348 			else if (lflag)
349 				num = va_arg(ap, u_long);
350 			else if (zflag)
351 				num = va_arg(ap, size_t);
352 			else if (hflag)
353 				num = (u_short)va_arg(ap, int);
354 			else if (cflag)
355 				num = (u_char)va_arg(ap, int);
356 			else
357 				num = va_arg(ap, u_int);
358 			goto number;
359 handle_sign:
360 			if (jflag)
361 				num = va_arg(ap, intmax_t);
362 			else if (qflag)
363 				num = va_arg(ap, quad_t);
364 			else if (tflag)
365 				num = va_arg(ap, ptrdiff_t);
366 			else if (lflag)
367 				num = va_arg(ap, long);
368 			else if (zflag)
369 				num = va_arg(ap, ssize_t);
370 			else if (hflag)
371 				num = (short)va_arg(ap, int);
372 			else if (cflag)
373 				num = (char)va_arg(ap, int);
374 			else
375 				num = va_arg(ap, int);
376 number:
377 			if (sign && (intmax_t)num < 0) {
378 				neg = 1;
379 				num = -(intmax_t)num;
380 			}
381 			p = ksprintn(nbuf, num, base, &n, upper);
382 			tmp = 0;
383 			if (sharpflag && num != 0) {
384 				if (base == 8)
385 					tmp++;
386 				else if (base == 16)
387 					tmp += 2;
388 			}
389 			if (neg)
390 				tmp++;
391 
392 			if (!ladjust && padc == '0')
393 				dwidth = width - tmp;
394 			width -= tmp + imax(dwidth, n);
395 			dwidth -= n;
396 			if (!ladjust)
397 				while (width-- > 0)
398 					PCHAR(' ');
399 			if (neg)
400 				PCHAR('-');
401 			if (sharpflag && num != 0) {
402 				if (base == 8) {
403 					PCHAR('0');
404 				} else if (base == 16) {
405 					PCHAR('0');
406 					PCHAR('x');
407 				}
408 			}
409 			while (dwidth-- > 0)
410 				PCHAR('0');
411 
412 			while (*p)
413 				PCHAR(*p--);
414 
415 			if (ladjust)
416 				while (width-- > 0)
417 					PCHAR(' ');
418 
419 			break;
420 		default:
421 			while (percent < fmt)
422 				PCHAR(*percent++);
423 			/*
424 			 * Since we ignore an formatting argument it is no
425 			 * longer safe to obey the remaining formatting
426 			 * arguments as the arguments will no longer match
427 			 * the format specs.
428 			 */
429 			stop = 1;
430 			break;
431 		}
432 	}
433 #undef PCHAR
434 }
435 
436 int
437 rtld_snprintf(char *buf, size_t bufsize, const char *fmt, ...)
438 {
439 	va_list ap;
440 	int retval;
441 
442 	va_start(ap, fmt);
443 	retval = rtld_vsnprintf(buf, bufsize, fmt, ap);
444 	va_end(ap);
445 	return (retval);
446 }
447 
448 int
449 rtld_vsnprintf(char *buf, size_t bufsize, const char *fmt, va_list ap)
450 {
451 	struct snprintf_arg info;
452 	int retval;
453 
454 	info.method = PRINT_METHOD_SNPRINTF;
455 	info.buf = info.str = buf;
456 	info.buf_total = info.remain = bufsize;
457 	info.fd = -1;
458 	retval = kvprintf(fmt, &info, 10, ap);
459 	if (info.remain >= 1)
460 		*info.str++ = '\0';
461 	return (retval);
462 }
463 
464 int
465 rtld_vfdprintf(int fd, const char *fmt, va_list ap)
466 {
467 	char buf[512];
468 	struct snprintf_arg info;
469 	int retval;
470 
471 	info.method = PRINT_METHOD_WRITE;
472 	info.buf = info.str = buf;
473 	info.buf_total = info.remain = sizeof(buf);
474 	info.fd = fd;
475 	retval = kvprintf(fmt, &info, 10, ap);
476 	printf_out(&info);
477 	return (retval);
478 }
479 
480 int
481 rtld_fdprintf(int fd, const char *fmt, ...)
482 {
483 	va_list ap;
484 	int retval;
485 
486 	va_start(ap, fmt);
487 	retval = rtld_vfdprintf(fd, fmt, ap);
488 	va_end(ap);
489 	return (retval);
490 }
491 
492 void
493 rtld_fdputstr(int fd, const char *str)
494 {
495 
496 	write(fd, str, strlen(str));
497 }
498 
499 void
500 rtld_fdputchar(int fd, int c)
501 {
502 	char c1;
503 
504 	c1 = c;
505 	write(fd, &c1, 1);
506 }
507