xref: /freebsd/libexec/rtld-elf/rtld_printf.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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 
38 #include <sys/param.h>
39 #include <inttypes.h>
40 #include <stdarg.h>
41 #include <stddef.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include "rtld_printf.h"
45 #include "rtld_libc.h"
46 
47 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
48 
49 #define	PRINT_METHOD_SNPRINTF	1
50 #define	PRINT_METHOD_WRITE	2
51 
52 struct snprintf_arg {
53 	int	method;
54 	char	*str;
55 	char	*buf;
56 	size_t	remain;
57 	size_t	buf_total;
58 	int	fd;
59 };
60 
61 static void
62 printf_out(struct snprintf_arg *info)
63 {
64 
65 	if (info->remain == info->buf_total)
66 		return;
67 	write(info->fd, info->buf, info->buf_total - info->remain);
68 	info->str = info->buf;
69 	info->remain = info->buf_total;
70 }
71 
72 static void
73 snprintf_func(int ch, struct snprintf_arg *const info)
74 {
75 
76 	switch (info->method) {
77 	case PRINT_METHOD_SNPRINTF:
78 		if (info->remain >= 2) {
79 			*info->str++ = ch;
80 			info->remain--;
81 		}
82 		break;
83 	case PRINT_METHOD_WRITE:
84 		if (info->remain == 0)
85 			printf_out(info);
86 		*info->str++ = ch;
87 		info->remain--;
88 		break;
89 	}
90 }
91 
92 static char const hex2ascii_lower[] = "0123456789abcdefghijklmnopqrstuvwxyz";
93 static char const hex2ascii_upper[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
94 #define	hex2ascii(hex)	(hex2ascii_lower[hex])
95 #define	hex2ascii_upper(hex)	(hex2ascii_upper[hex])
96 
97 static __inline int
98 imax(int a, int b)
99 {
100 
101 	return (a > b ? a : b);
102 }
103 
104 static char *
105 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
106 {
107 	char *p, c;
108 
109 	p = nbuf;
110 	*p = '\0';
111 	do {
112 		c = upper ? hex2ascii_upper(num % base) :
113 		    hex2ascii(num % base);
114 		*++p = c;
115 	} while (num /= base);
116 	if (lenp)
117 		*lenp = p - nbuf;
118 	return (p);
119 }
120 
121 static int
122 kvprintf(char const *fmt, struct snprintf_arg *arg, int radix, va_list ap)
123 {
124 #define PCHAR(c) snprintf_func((c), arg)
125 	char nbuf[MAXNBUF];
126 	const char *p, *percent, *q;
127 	u_char *up;
128 	int ch, n;
129 	uintmax_t num;
130 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
131 	int cflag, hflag, jflag, tflag, zflag;
132 	int dwidth, upper;
133 	char padc;
134 	int stop = 0, retval = 0;
135 
136 	num = 0;
137 
138 	if (fmt == NULL)
139 		fmt = "(fmt null)\n";
140 
141 	if (radix < 2 || radix > 36)
142 		radix = 10;
143 
144 	for (;;) {
145 		padc = ' ';
146 		width = 0;
147 		while ((ch = (u_char)*fmt++) != '%' || stop) {
148 			if (ch == '\0')
149 				return (retval);
150 			PCHAR(ch);
151 		}
152 		percent = fmt - 1;
153 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
154 		sign = 0; dot = 0; dwidth = 0; upper = 0;
155 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
156 reswitch:	switch (ch = (u_char)*fmt++) {
157 		case '.':
158 			dot = 1;
159 			goto reswitch;
160 		case '#':
161 			sharpflag = 1;
162 			goto reswitch;
163 		case '+':
164 			sign = 1;
165 			goto reswitch;
166 		case '-':
167 			ladjust = 1;
168 			goto reswitch;
169 		case '%':
170 			PCHAR(ch);
171 			break;
172 		case '*':
173 			if (!dot) {
174 				width = va_arg(ap, int);
175 				if (width < 0) {
176 					ladjust = !ladjust;
177 					width = -width;
178 				}
179 			} else {
180 				dwidth = va_arg(ap, int);
181 			}
182 			goto reswitch;
183 		case '0':
184 			if (!dot) {
185 				padc = '0';
186 				goto reswitch;
187 			}
188 			/* FALLTHROUGH */
189 		case '1': case '2': case '3': case '4':
190 		case '5': case '6': case '7': case '8': case '9':
191 				for (n = 0;; ++fmt) {
192 					n = n * 10 + ch - '0';
193 					ch = *fmt;
194 					if (ch < '0' || ch > '9')
195 						break;
196 				}
197 			if (dot)
198 				dwidth = n;
199 			else
200 				width = n;
201 			goto reswitch;
202 		case 'b':
203 			num = (u_int)va_arg(ap, int);
204 			p = va_arg(ap, char *);
205 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
206 				PCHAR(*q--);
207 
208 			if (num == 0)
209 				break;
210 
211 			for (tmp = 0; *p;) {
212 				n = *p++;
213 				if (num & (1 << (n - 1))) {
214 					PCHAR(tmp ? ',' : '<');
215 					for (; (n = *p) > ' '; ++p)
216 						PCHAR(n);
217 					tmp = 1;
218 				} else
219 					for (; *p > ' '; ++p)
220 						continue;
221 			}
222 			if (tmp)
223 				PCHAR('>');
224 			break;
225 		case 'c':
226 			PCHAR(va_arg(ap, int));
227 			break;
228 		case 'D':
229 			up = va_arg(ap, u_char *);
230 			p = va_arg(ap, char *);
231 			if (!width)
232 				width = 16;
233 			while(width--) {
234 				PCHAR(hex2ascii(*up >> 4));
235 				PCHAR(hex2ascii(*up & 0x0f));
236 				up++;
237 				if (width)
238 					for (q=p;*q;q++)
239 						PCHAR(*q);
240 			}
241 			break;
242 		case 'd':
243 		case 'i':
244 			base = 10;
245 			sign = 1;
246 			goto handle_sign;
247 		case 'h':
248 			if (hflag) {
249 				hflag = 0;
250 				cflag = 1;
251 			} else
252 				hflag = 1;
253 			goto reswitch;
254 		case 'j':
255 			jflag = 1;
256 			goto reswitch;
257 		case 'l':
258 			if (lflag) {
259 				lflag = 0;
260 				qflag = 1;
261 			} else
262 				lflag = 1;
263 			goto reswitch;
264 		case 'n':
265 			if (jflag)
266 				*(va_arg(ap, intmax_t *)) = retval;
267 			else if (qflag)
268 				*(va_arg(ap, quad_t *)) = retval;
269 			else if (lflag)
270 				*(va_arg(ap, long *)) = retval;
271 			else if (zflag)
272 				*(va_arg(ap, size_t *)) = retval;
273 			else if (hflag)
274 				*(va_arg(ap, short *)) = retval;
275 			else if (cflag)
276 				*(va_arg(ap, char *)) = retval;
277 			else
278 				*(va_arg(ap, int *)) = retval;
279 			break;
280 		case 'o':
281 			base = 8;
282 			goto handle_nosign;
283 		case 'p':
284 			base = 16;
285 			sharpflag = (width == 0);
286 			sign = 0;
287 			num = (uintptr_t)va_arg(ap, void *);
288 			goto number;
289 		case 'q':
290 			qflag = 1;
291 			goto reswitch;
292 		case 'r':
293 			base = radix;
294 			if (sign)
295 				goto handle_sign;
296 			goto handle_nosign;
297 		case 's':
298 			p = va_arg(ap, char *);
299 			if (p == NULL)
300 				p = "(null)";
301 			if (!dot)
302 				n = strlen (p);
303 			else
304 				for (n = 0; n < dwidth && p[n]; n++)
305 					continue;
306 
307 			width -= n;
308 
309 			if (!ladjust && width > 0)
310 				while (width--)
311 					PCHAR(padc);
312 			while (n--)
313 				PCHAR(*p++);
314 			if (ladjust && width > 0)
315 				while (width--)
316 					PCHAR(padc);
317 			break;
318 		case 't':
319 			tflag = 1;
320 			goto reswitch;
321 		case 'u':
322 			base = 10;
323 			goto handle_nosign;
324 		case 'X':
325 			upper = 1;
326 			/* FALLTHROUGH */
327 		case 'x':
328 			base = 16;
329 			goto handle_nosign;
330 		case 'y':
331 			base = 16;
332 			sign = 1;
333 			goto handle_sign;
334 		case 'z':
335 			zflag = 1;
336 			goto reswitch;
337 handle_nosign:
338 			sign = 0;
339 			if (jflag)
340 				num = va_arg(ap, uintmax_t);
341 			else if (qflag)
342 				num = va_arg(ap, u_quad_t);
343 			else if (tflag)
344 				num = va_arg(ap, ptrdiff_t);
345 			else if (lflag)
346 				num = va_arg(ap, u_long);
347 			else if (zflag)
348 				num = va_arg(ap, size_t);
349 			else if (hflag)
350 				num = (u_short)va_arg(ap, int);
351 			else if (cflag)
352 				num = (u_char)va_arg(ap, int);
353 			else
354 				num = va_arg(ap, u_int);
355 			goto number;
356 handle_sign:
357 			if (jflag)
358 				num = va_arg(ap, intmax_t);
359 			else if (qflag)
360 				num = va_arg(ap, quad_t);
361 			else if (tflag)
362 				num = va_arg(ap, ptrdiff_t);
363 			else if (lflag)
364 				num = va_arg(ap, long);
365 			else if (zflag)
366 				num = va_arg(ap, ssize_t);
367 			else if (hflag)
368 				num = (short)va_arg(ap, int);
369 			else if (cflag)
370 				num = (char)va_arg(ap, int);
371 			else
372 				num = va_arg(ap, int);
373 number:
374 			if (sign && (intmax_t)num < 0) {
375 				neg = 1;
376 				num = -(intmax_t)num;
377 			}
378 			p = ksprintn(nbuf, num, base, &n, upper);
379 			tmp = 0;
380 			if (sharpflag && num != 0) {
381 				if (base == 8)
382 					tmp++;
383 				else if (base == 16)
384 					tmp += 2;
385 			}
386 			if (neg)
387 				tmp++;
388 
389 			if (!ladjust && padc == '0')
390 				dwidth = width - tmp;
391 			width -= tmp + imax(dwidth, n);
392 			dwidth -= n;
393 			if (!ladjust)
394 				while (width-- > 0)
395 					PCHAR(' ');
396 			if (neg)
397 				PCHAR('-');
398 			if (sharpflag && num != 0) {
399 				if (base == 8) {
400 					PCHAR('0');
401 				} else if (base == 16) {
402 					PCHAR('0');
403 					PCHAR('x');
404 				}
405 			}
406 			while (dwidth-- > 0)
407 				PCHAR('0');
408 
409 			while (*p)
410 				PCHAR(*p--);
411 
412 			if (ladjust)
413 				while (width-- > 0)
414 					PCHAR(' ');
415 
416 			break;
417 		default:
418 			while (percent < fmt)
419 				PCHAR(*percent++);
420 			/*
421 			 * Since we ignore an formatting argument it is no
422 			 * longer safe to obey the remaining formatting
423 			 * arguments as the arguments will no longer match
424 			 * the format specs.
425 			 */
426 			stop = 1;
427 			break;
428 		}
429 	}
430 #undef PCHAR
431 }
432 
433 int
434 rtld_snprintf(char *buf, size_t bufsize, const char *fmt, ...)
435 {
436 	va_list ap;
437 	int retval;
438 
439 	va_start(ap, fmt);
440 	retval = rtld_vsnprintf(buf, bufsize, fmt, ap);
441 	va_end(ap);
442 	return (retval);
443 }
444 
445 int
446 rtld_vsnprintf(char *buf, size_t bufsize, const char *fmt, va_list ap)
447 {
448 	struct snprintf_arg info;
449 	int retval;
450 
451 	info.method = PRINT_METHOD_SNPRINTF;
452 	info.buf = info.str = buf;
453 	info.buf_total = info.remain = bufsize;
454 	info.fd = -1;
455 	retval = kvprintf(fmt, &info, 10, ap);
456 	if (info.remain >= 1)
457 		*info.str++ = '\0';
458 	return (retval);
459 }
460 
461 int
462 rtld_vfdprintf(int fd, const char *fmt, va_list ap)
463 {
464 	char buf[512];
465 	struct snprintf_arg info;
466 	int retval;
467 
468 	info.method = PRINT_METHOD_WRITE;
469 	info.buf = info.str = buf;
470 	info.buf_total = info.remain = sizeof(buf);
471 	info.fd = fd;
472 	retval = kvprintf(fmt, &info, 10, ap);
473 	printf_out(&info);
474 	return (retval);
475 }
476 
477 int
478 rtld_fdprintf(int fd, const char *fmt, ...)
479 {
480 	va_list ap;
481 	int retval;
482 
483 	va_start(ap, fmt);
484 	retval = rtld_vfdprintf(fd, fmt, ap);
485 	va_end(ap);
486 	return (retval);
487 }
488 
489 int
490 rtld_fdprintfx(int fd, const char *fmt, ...)
491 {
492 	va_list ap;
493 	int retval;
494 
495 	va_start(ap, fmt);
496 	retval = rtld_vfdprintf(fd, fmt, ap);
497 	va_end(ap);
498 	return (retval);
499 }
500 
501 void
502 rtld_fdputstr(int fd, const char *str)
503 {
504 
505 	write(fd, str, strlen(str));
506 }
507 
508 void
509 rtld_fdputchar(int fd, int c)
510 {
511 	char c1;
512 
513 	c1 = c;
514 	write(fd, &c1, 1);
515 }
516