xref: /freebsd/usr.bin/hexdump/display.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #include <sys/param.h>
39 #include <sys/capsicum.h>
40 #include <sys/conf.h>
41 #include <sys/ioctl.h>
42 #include <sys/stat.h>
43 
44 #include <capsicum_helpers.h>
45 #include <ctype.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "hexdump.h"
53 
54 enum _vflag vflag = FIRST;
55 
56 static off_t address;			/* address/offset in stream */
57 static off_t eaddress;			/* end address */
58 
59 static void print(PR *, u_char *);
60 static void noseek(void);
61 
62 void
63 display(void)
64 {
65 	FS *fs;
66 	FU *fu;
67 	PR *pr;
68 	int cnt;
69 	u_char *bp;
70 	off_t saveaddress;
71 	u_char savech, *savebp;
72 
73 	savech = 0;
74 	while ((bp = get()))
75 	    for (fs = fshead, savebp = bp, saveaddress = address; fs;
76 		fs = fs->nextfs, bp = savebp, address = saveaddress)
77 		    for (fu = fs->nextfu; fu; fu = fu->nextfu) {
78 			if (fu->flags&F_IGNORE)
79 				break;
80 			for (cnt = fu->reps; cnt; --cnt)
81 			    for (pr = fu->nextpr; pr; address += pr->bcnt,
82 				bp += pr->bcnt, pr = pr->nextpr) {
83 				    if (eaddress && address >= eaddress &&
84 					!(pr->flags & (F_TEXT|F_BPAD)))
85 					    bpad(pr);
86 				    if (cnt == 1 && pr->nospace) {
87 					savech = *pr->nospace;
88 					*pr->nospace = '\0';
89 				    }
90 				    print(pr, bp);
91 				    if (cnt == 1 && pr->nospace)
92 					*pr->nospace = savech;
93 			    }
94 		    }
95 	if (endfu) {
96 		/*
97 		 * If eaddress not set, error or file size was multiple of
98 		 * blocksize, and no partial block ever found.
99 		 */
100 		if (!eaddress) {
101 			if (!address)
102 				return;
103 			eaddress = address;
104 		}
105 		for (pr = endfu->nextpr; pr; pr = pr->nextpr)
106 			switch(pr->flags) {
107 			case F_ADDRESS:
108 				(void)printf(pr->fmt, (quad_t)eaddress);
109 				break;
110 			case F_TEXT:
111 				(void)printf("%s", pr->fmt);
112 				break;
113 			}
114 	}
115 }
116 
117 static void
118 print(PR *pr, u_char *bp)
119 {
120 	long double ldbl;
121 	   double f8;
122 	    float f4;
123 	  int16_t s2;
124 	  int32_t s4;
125 	  int64_t s8;
126 	u_int16_t u2;
127 	u_int32_t u4;
128 	u_int64_t u8;
129 
130 	switch(pr->flags) {
131 	case F_ADDRESS:
132 		(void)printf(pr->fmt, (quad_t)address);
133 		break;
134 	case F_BPAD:
135 		(void)printf(pr->fmt, "");
136 		break;
137 	case F_C:
138 		conv_c(pr, bp, eaddress ? eaddress - address :
139 		    blocksize - address % blocksize);
140 		break;
141 	case F_CHAR:
142 		(void)printf(pr->fmt, *bp);
143 		break;
144 	case F_DBL:
145 		switch(pr->bcnt) {
146 		case 4:
147 			bcopy(bp, &f4, sizeof(f4));
148 			(void)printf(pr->fmt, f4);
149 			break;
150 		case 8:
151 			bcopy(bp, &f8, sizeof(f8));
152 			(void)printf(pr->fmt, f8);
153 			break;
154 		default:
155 			if (pr->bcnt == sizeof(long double)) {
156 				bcopy(bp, &ldbl, sizeof(ldbl));
157 				(void)printf(pr->fmt, ldbl);
158 			}
159 			break;
160 		}
161 		break;
162 	case F_INT:
163 		switch(pr->bcnt) {
164 		case 1:
165 			(void)printf(pr->fmt, (quad_t)(signed char)*bp);
166 			break;
167 		case 2:
168 			bcopy(bp, &s2, sizeof(s2));
169 			(void)printf(pr->fmt, (quad_t)s2);
170 			break;
171 		case 4:
172 			bcopy(bp, &s4, sizeof(s4));
173 			(void)printf(pr->fmt, (quad_t)s4);
174 			break;
175 		case 8:
176 			bcopy(bp, &s8, sizeof(s8));
177 			(void)printf(pr->fmt, s8);
178 			break;
179 		}
180 		break;
181 	case F_P:
182 		(void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
183 		break;
184 	case F_STR:
185 		(void)printf(pr->fmt, (char *)bp);
186 		break;
187 	case F_TEXT:
188 		(void)printf("%s", pr->fmt);
189 		break;
190 	case F_U:
191 		conv_u(pr, bp);
192 		break;
193 	case F_UINT:
194 		switch(pr->bcnt) {
195 		case 1:
196 			(void)printf(pr->fmt, (u_quad_t)*bp);
197 			break;
198 		case 2:
199 			bcopy(bp, &u2, sizeof(u2));
200 			(void)printf(pr->fmt, (u_quad_t)u2);
201 			break;
202 		case 4:
203 			bcopy(bp, &u4, sizeof(u4));
204 			(void)printf(pr->fmt, (u_quad_t)u4);
205 			break;
206 		case 8:
207 			bcopy(bp, &u8, sizeof(u8));
208 			(void)printf(pr->fmt, u8);
209 			break;
210 		}
211 		break;
212 	}
213 }
214 
215 void
216 bpad(PR *pr)
217 {
218 	static char const *spec = " -0+#";
219 	char *p1, *p2;
220 
221 	/*
222 	 * Remove all conversion flags; '-' is the only one valid
223 	 * with %s, and it's not useful here.
224 	 */
225 	pr->flags = F_BPAD;
226 	pr->cchar[0] = 's';
227 	pr->cchar[1] = '\0';
228 	for (p1 = pr->fmt; *p1 != '%'; ++p1);
229 	for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
230 	while ((*p2++ = *p1++));
231 }
232 
233 static char **_argv;
234 
235 u_char *
236 get(void)
237 {
238 	static int ateof = 1;
239 	static u_char *curp, *savp;
240 	int n;
241 	int need, nread;
242 	int valid_save = 0;
243 	u_char *tmpp;
244 
245 	if (!curp) {
246 		if ((curp = calloc(1, blocksize)) == NULL)
247 			err(1, NULL);
248 		if ((savp = calloc(1, blocksize)) == NULL)
249 			err(1, NULL);
250 	} else {
251 		tmpp = curp;
252 		curp = savp;
253 		savp = tmpp;
254 		address += blocksize;
255 		valid_save = 1;
256 	}
257 	for (need = blocksize, nread = 0;;) {
258 		/*
259 		 * if read the right number of bytes, or at EOF for one file,
260 		 * and no other files are available, zero-pad the rest of the
261 		 * block and set the end flag.
262 		 */
263 		if (!length || (ateof && !next((char **)NULL))) {
264 			if (odmode && skip > 0)
265 				errx(1, "cannot skip past end of input");
266 			if (need == blocksize)
267 				return((u_char *)NULL);
268 			/*
269 			 * XXX bcmp() is not quite right in the presence
270 			 * of multibyte characters.
271 			 */
272 			if (need == 0 && vflag != ALL &&
273 			    valid_save &&
274 			    bcmp(curp, savp, nread) == 0) {
275 				if (vflag != DUP) {
276 					(void)printf("*\n");
277 					(void)fflush(stdout);
278 				}
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 				(void)fflush(stdout);
311 			}
312 			vflag = DUP;
313 			address += blocksize;
314 			need = blocksize;
315 			nread = 0;
316 		}
317 		else
318 			nread += n;
319 	}
320 }
321 
322 size_t
323 peek(u_char *buf, size_t nbytes)
324 {
325 	size_t n, nread;
326 	int c;
327 
328 	if (length != -1 && nbytes > (unsigned int)length)
329 		nbytes = length;
330 	nread = 0;
331 	while (nread < nbytes && (c = getchar()) != EOF) {
332 		*buf++ = c;
333 		nread++;
334 	}
335 	n = nread;
336 	while (n-- > 0) {
337 		c = *--buf;
338 		ungetc(c, stdin);
339 	}
340 	return (nread);
341 }
342 
343 int
344 next(char **argv)
345 {
346 	static int done;
347 	int statok;
348 
349 	if (argv) {
350 		_argv = argv;
351 		return(1);
352 	}
353 	for (;;) {
354 		if (*_argv) {
355 			done = 1;
356 			if (!(freopen(*_argv, "r", stdin))) {
357 				warn("%s", *_argv);
358 				exitval = 1;
359 				++_argv;
360 				continue;
361 			}
362 			statok = 1;
363 		} else {
364 			if (done++)
365 				return(0);
366 			statok = 0;
367 		}
368 
369 		if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
370 			err(1, "unable to restrict %s",
371 			    statok ? *_argv : "stdin");
372 
373 		/*
374 		 * We've opened our last input file; enter capsicum sandbox.
375 		 */
376 		if (statok == 0 || *(_argv + 1) == NULL) {
377 			if (caph_enter() < 0)
378 				err(1, "unable to enter capability mode");
379 		}
380 
381 		if (skip)
382 			doskip(statok ? *_argv : "stdin", statok);
383 		if (*_argv)
384 			++_argv;
385 		if (!skip)
386 			return(1);
387 	}
388 	/* NOTREACHED */
389 }
390 
391 void
392 doskip(const char *fname, int statok)
393 {
394 	int type;
395 	struct stat sb;
396 
397 	if (statok) {
398 		if (fstat(fileno(stdin), &sb))
399 			err(1, "%s", fname);
400 		if (S_ISREG(sb.st_mode) && skip > sb.st_size) {
401 			address += sb.st_size;
402 			skip -= sb.st_size;
403 			return;
404 		}
405 	}
406 	if (!statok || S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode)) {
407 		noseek();
408 		return;
409 	}
410 	if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
411 		if (ioctl(fileno(stdin), FIODTYPE, &type))
412 			err(1, "%s", fname);
413 		/*
414 		 * Most tape drives don't support seeking,
415 		 * yet fseek() would succeed.
416 		 */
417 		if (type & D_TAPE) {
418 			noseek();
419 			return;
420 		}
421 	}
422 	if (fseeko(stdin, skip, SEEK_SET)) {
423 		noseek();
424 		return;
425 	}
426 	address += skip;
427 	skip = 0;
428 }
429 
430 static void
431 noseek(void)
432 {
433 	int count;
434 	for (count = 0; count < skip; ++count)
435 		if (getchar() == EOF)
436 			break;
437 	address += count;
438 	skip -= count;
439 }
440