xref: /freebsd/usr.bin/hexdump/display.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)display.c	8.1 (Berkeley) 6/6/93";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/capsicum.h>
42 #include <sys/conf.h>
43 #include <sys/ioctl.h>
44 #include <sys/stat.h>
45 
46 #include <capsicum_helpers.h>
47 #include <ctype.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include "hexdump.h"
55 
56 enum _vflag vflag = FIRST;
57 
58 static off_t address;			/* address/offset in stream */
59 static off_t eaddress;			/* end address */
60 
61 static void print(PR *, u_char *);
62 static void noseek(void);
63 
64 void
65 display(void)
66 {
67 	FS *fs;
68 	FU *fu;
69 	PR *pr;
70 	int cnt;
71 	u_char *bp;
72 	off_t saveaddress;
73 	u_char savech, *savebp;
74 
75 	savech = 0;
76 	while ((bp = get()))
77 	    for (fs = fshead, savebp = bp, saveaddress = address; fs;
78 		fs = fs->nextfs, bp = savebp, address = saveaddress)
79 		    for (fu = fs->nextfu; fu; fu = fu->nextfu) {
80 			if (fu->flags&F_IGNORE)
81 				break;
82 			for (cnt = fu->reps; cnt; --cnt)
83 			    for (pr = fu->nextpr; pr; address += pr->bcnt,
84 				bp += pr->bcnt, pr = pr->nextpr) {
85 				    if (eaddress && address >= eaddress &&
86 					!(pr->flags & (F_TEXT|F_BPAD)))
87 					    bpad(pr);
88 				    if (cnt == 1 && pr->nospace) {
89 					savech = *pr->nospace;
90 					*pr->nospace = '\0';
91 				    }
92 				    print(pr, bp);
93 				    if (cnt == 1 && pr->nospace)
94 					*pr->nospace = savech;
95 			    }
96 		    }
97 	if (endfu) {
98 		/*
99 		 * If eaddress not set, error or file size was multiple of
100 		 * blocksize, and no partial block ever found.
101 		 */
102 		if (!eaddress) {
103 			if (!address)
104 				return;
105 			eaddress = address;
106 		}
107 		for (pr = endfu->nextpr; pr; pr = pr->nextpr)
108 			switch(pr->flags) {
109 			case F_ADDRESS:
110 				(void)printf(pr->fmt, (quad_t)eaddress);
111 				break;
112 			case F_TEXT:
113 				(void)printf("%s", pr->fmt);
114 				break;
115 			}
116 	}
117 }
118 
119 static void
120 print(PR *pr, u_char *bp)
121 {
122 	long double ldbl;
123 	   double f8;
124 	    float f4;
125 	  int16_t s2;
126 	   int8_t s8;
127 	  int32_t s4;
128 	u_int16_t u2;
129 	u_int32_t u4;
130 	u_int64_t u8;
131 
132 	switch(pr->flags) {
133 	case F_ADDRESS:
134 		(void)printf(pr->fmt, (quad_t)address);
135 		break;
136 	case F_BPAD:
137 		(void)printf(pr->fmt, "");
138 		break;
139 	case F_C:
140 		conv_c(pr, bp, eaddress ? eaddress - address :
141 		    blocksize - address % blocksize);
142 		break;
143 	case F_CHAR:
144 		(void)printf(pr->fmt, *bp);
145 		break;
146 	case F_DBL:
147 		switch(pr->bcnt) {
148 		case 4:
149 			bcopy(bp, &f4, sizeof(f4));
150 			(void)printf(pr->fmt, f4);
151 			break;
152 		case 8:
153 			bcopy(bp, &f8, sizeof(f8));
154 			(void)printf(pr->fmt, f8);
155 			break;
156 		default:
157 			if (pr->bcnt == sizeof(long double)) {
158 				bcopy(bp, &ldbl, sizeof(ldbl));
159 				(void)printf(pr->fmt, ldbl);
160 			}
161 			break;
162 		}
163 		break;
164 	case F_INT:
165 		switch(pr->bcnt) {
166 		case 1:
167 			(void)printf(pr->fmt, (quad_t)(signed char)*bp);
168 			break;
169 		case 2:
170 			bcopy(bp, &s2, sizeof(s2));
171 			(void)printf(pr->fmt, (quad_t)s2);
172 			break;
173 		case 4:
174 			bcopy(bp, &s4, sizeof(s4));
175 			(void)printf(pr->fmt, (quad_t)s4);
176 			break;
177 		case 8:
178 			bcopy(bp, &s8, sizeof(s8));
179 			(void)printf(pr->fmt, s8);
180 			break;
181 		}
182 		break;
183 	case F_P:
184 		(void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
185 		break;
186 	case F_STR:
187 		(void)printf(pr->fmt, (char *)bp);
188 		break;
189 	case F_TEXT:
190 		(void)printf("%s", pr->fmt);
191 		break;
192 	case F_U:
193 		conv_u(pr, bp);
194 		break;
195 	case F_UINT:
196 		switch(pr->bcnt) {
197 		case 1:
198 			(void)printf(pr->fmt, (u_quad_t)*bp);
199 			break;
200 		case 2:
201 			bcopy(bp, &u2, sizeof(u2));
202 			(void)printf(pr->fmt, (u_quad_t)u2);
203 			break;
204 		case 4:
205 			bcopy(bp, &u4, sizeof(u4));
206 			(void)printf(pr->fmt, (u_quad_t)u4);
207 			break;
208 		case 8:
209 			bcopy(bp, &u8, sizeof(u8));
210 			(void)printf(pr->fmt, u8);
211 			break;
212 		}
213 		break;
214 	}
215 }
216 
217 void
218 bpad(PR *pr)
219 {
220 	static char const *spec = " -0+#";
221 	char *p1, *p2;
222 
223 	/*
224 	 * Remove all conversion flags; '-' is the only one valid
225 	 * with %s, and it's not useful here.
226 	 */
227 	pr->flags = F_BPAD;
228 	pr->cchar[0] = 's';
229 	pr->cchar[1] = '\0';
230 	for (p1 = pr->fmt; *p1 != '%'; ++p1);
231 	for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
232 	while ((*p2++ = *p1++));
233 }
234 
235 static char **_argv;
236 
237 u_char *
238 get(void)
239 {
240 	static int ateof = 1;
241 	static u_char *curp, *savp;
242 	int n;
243 	int need, nread;
244 	int valid_save = 0;
245 	u_char *tmpp;
246 
247 	if (!curp) {
248 		if ((curp = calloc(1, blocksize)) == NULL)
249 			err(1, NULL);
250 		if ((savp = calloc(1, blocksize)) == NULL)
251 			err(1, NULL);
252 	} else {
253 		tmpp = curp;
254 		curp = savp;
255 		savp = tmpp;
256 		address += blocksize;
257 		valid_save = 1;
258 	}
259 	for (need = blocksize, nread = 0;;) {
260 		/*
261 		 * if read the right number of bytes, or at EOF for one file,
262 		 * and no other files are available, zero-pad the rest of the
263 		 * block and set the end flag.
264 		 */
265 		if (!length || (ateof && !next((char **)NULL))) {
266 			if (odmode && address < skip)
267 				errx(1, "cannot skip past end of input");
268 			if (need == blocksize)
269 				return((u_char *)NULL);
270 			/*
271 			 * XXX bcmp() is not quite right in the presence
272 			 * of multibyte characters.
273 			 */
274 			if (vflag != ALL &&
275 			    valid_save &&
276 			    bcmp(curp, savp, nread) == 0) {
277 				if (vflag != DUP)
278 					(void)printf("*\n");
279 				return((u_char *)NULL);
280 			}
281 			bzero((char *)curp + nread, need);
282 			eaddress = address + nread;
283 			return(curp);
284 		}
285 		n = fread((char *)curp + nread, sizeof(u_char),
286 		    length == -1 ? need : MIN(length, need), stdin);
287 		if (!n) {
288 			if (ferror(stdin))
289 				warn("%s", _argv[-1]);
290 			ateof = 1;
291 			continue;
292 		}
293 		ateof = 0;
294 		if (length != -1)
295 			length -= n;
296 		if (!(need -= n)) {
297 			/*
298 			 * XXX bcmp() is not quite right in the presence
299 			 * of multibyte characters.
300 			 */
301 			if (vflag == ALL || vflag == FIRST ||
302 			    valid_save == 0 ||
303 			    bcmp(curp, savp, blocksize) != 0) {
304 				if (vflag == DUP || vflag == FIRST)
305 					vflag = WAIT;
306 				return(curp);
307 			}
308 			if (vflag == WAIT)
309 				(void)printf("*\n");
310 			vflag = DUP;
311 			address += blocksize;
312 			need = blocksize;
313 			nread = 0;
314 		}
315 		else
316 			nread += n;
317 	}
318 }
319 
320 size_t
321 peek(u_char *buf, size_t nbytes)
322 {
323 	size_t n, nread;
324 	int c;
325 
326 	if (length != -1 && nbytes > (unsigned int)length)
327 		nbytes = length;
328 	nread = 0;
329 	while (nread < nbytes && (c = getchar()) != EOF) {
330 		*buf++ = c;
331 		nread++;
332 	}
333 	n = nread;
334 	while (n-- > 0) {
335 		c = *--buf;
336 		ungetc(c, stdin);
337 	}
338 	return (nread);
339 }
340 
341 int
342 next(char **argv)
343 {
344 	static int done;
345 	int statok;
346 
347 	if (argv) {
348 		_argv = argv;
349 		return(1);
350 	}
351 	for (;;) {
352 		if (*_argv) {
353 			done = 1;
354 			if (!(freopen(*_argv, "r", stdin))) {
355 				warn("%s", *_argv);
356 				exitval = 1;
357 				++_argv;
358 				continue;
359 			}
360 			statok = 1;
361 		} else {
362 			if (done++)
363 				return(0);
364 			statok = 0;
365 		}
366 
367 		if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
368 			err(1, "unable to restrict %s",
369 			    statok ? *_argv : "stdin");
370 
371 		/*
372 		 * We've opened our last input file; enter capsicum sandbox.
373 		 */
374 		if (statok == 0 || *(_argv + 1) == NULL) {
375 			if (cap_enter() < 0 && errno != ENOSYS)
376 				err(1, "unable to enter capability mode");
377 		}
378 
379 		if (skip)
380 			doskip(statok ? *_argv : "stdin", statok);
381 		if (*_argv)
382 			++_argv;
383 		if (!skip)
384 			return(1);
385 	}
386 	/* NOTREACHED */
387 }
388 
389 void
390 doskip(const char *fname, int statok)
391 {
392 	int type;
393 	struct stat sb;
394 
395 	if (statok) {
396 		if (fstat(fileno(stdin), &sb))
397 			err(1, "%s", fname);
398 		if (S_ISREG(sb.st_mode) && skip > sb.st_size) {
399 			address += sb.st_size;
400 			skip -= sb.st_size;
401 			return;
402 		}
403 	}
404 	if (!statok || S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode)) {
405 		noseek();
406 		return;
407 	}
408 	if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
409 		if (ioctl(fileno(stdin), FIODTYPE, &type))
410 			err(1, "%s", fname);
411 		/*
412 		 * Most tape drives don't support seeking,
413 		 * yet fseek() would succeed.
414 		 */
415 		if (type & D_TAPE) {
416 			noseek();
417 			return;
418 		}
419 	}
420 	if (fseeko(stdin, skip, SEEK_SET)) {
421 		noseek();
422 		return;
423 	}
424 	address += skip;
425 	skip = 0;
426 }
427 
428 static void
429 noseek(void)
430 {
431 	int count;
432 	for (count = 0; count < skip; ++count)
433 		if (getchar() == EOF)
434 			break;
435 	address += count;
436 	skip -= count;
437 }
438