xref: /freebsd/usr.bin/hexdump/display.c (revision 97cb52fa9aefd90fad38790fded50905aeeb9b9e)
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/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 
61 void
62 display(void)
63 {
64 	FS *fs;
65 	FU *fu;
66 	PR *pr;
67 	int cnt;
68 	u_char *bp;
69 	off_t saveaddress;
70 	u_char savech, *savebp;
71 
72 	savech = 0;
73 	while ((bp = get()))
74 	    for (fs = fshead, savebp = bp, saveaddress = address; fs;
75 		fs = fs->nextfs, bp = savebp, address = saveaddress)
76 		    for (fu = fs->nextfu; fu; fu = fu->nextfu) {
77 			if (fu->flags&F_IGNORE)
78 				break;
79 			for (cnt = fu->reps; cnt; --cnt)
80 			    for (pr = fu->nextpr; pr; address += pr->bcnt,
81 				bp += pr->bcnt, pr = pr->nextpr) {
82 				    if (eaddress && address >= eaddress &&
83 					!(pr->flags & (F_TEXT|F_BPAD)))
84 					    bpad(pr);
85 				    if (cnt == 1 && pr->nospace) {
86 					savech = *pr->nospace;
87 					*pr->nospace = '\0';
88 				    }
89 				    print(pr, bp);
90 				    if (cnt == 1 && pr->nospace)
91 					*pr->nospace = savech;
92 			    }
93 		    }
94 	if (endfu) {
95 		/*
96 		 * If eaddress not set, error or file size was multiple of
97 		 * blocksize, and no partial block ever found.
98 		 */
99 		if (!eaddress) {
100 			if (!address)
101 				return;
102 			eaddress = address;
103 		}
104 		for (pr = endfu->nextpr; pr; pr = pr->nextpr)
105 			switch(pr->flags) {
106 			case F_ADDRESS:
107 				(void)printf(pr->fmt, (quad_t)eaddress);
108 				break;
109 			case F_TEXT:
110 				(void)printf("%s", pr->fmt);
111 				break;
112 			}
113 	}
114 }
115 
116 static void
117 print(PR *pr, u_char *bp)
118 {
119 	long double ldbl;
120 	   double f8;
121 	    float f4;
122 	  int16_t s2;
123 	   int8_t s8;
124 	  int32_t s4;
125 	u_int16_t u2;
126 	u_int32_t u4;
127 	u_int64_t u8;
128 
129 	switch(pr->flags) {
130 	case F_ADDRESS:
131 		(void)printf(pr->fmt, (quad_t)address);
132 		break;
133 	case F_BPAD:
134 		(void)printf(pr->fmt, "");
135 		break;
136 	case F_C:
137 		conv_c(pr, bp, eaddress ? eaddress - address :
138 		    blocksize - address % blocksize);
139 		break;
140 	case F_CHAR:
141 		(void)printf(pr->fmt, *bp);
142 		break;
143 	case F_DBL:
144 		switch(pr->bcnt) {
145 		case 4:
146 			bcopy(bp, &f4, sizeof(f4));
147 			(void)printf(pr->fmt, f4);
148 			break;
149 		case 8:
150 			bcopy(bp, &f8, sizeof(f8));
151 			(void)printf(pr->fmt, f8);
152 			break;
153 		default:
154 			if (pr->bcnt == sizeof(long double)) {
155 				bcopy(bp, &ldbl, sizeof(ldbl));
156 				(void)printf(pr->fmt, ldbl);
157 			}
158 			break;
159 		}
160 		break;
161 	case F_INT:
162 		switch(pr->bcnt) {
163 		case 1:
164 			(void)printf(pr->fmt, (quad_t)(signed char)*bp);
165 			break;
166 		case 2:
167 			bcopy(bp, &s2, sizeof(s2));
168 			(void)printf(pr->fmt, (quad_t)s2);
169 			break;
170 		case 4:
171 			bcopy(bp, &s4, sizeof(s4));
172 			(void)printf(pr->fmt, (quad_t)s4);
173 			break;
174 		case 8:
175 			bcopy(bp, &s8, sizeof(s8));
176 			(void)printf(pr->fmt, s8);
177 			break;
178 		}
179 		break;
180 	case F_P:
181 		(void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
182 		break;
183 	case F_STR:
184 		(void)printf(pr->fmt, (char *)bp);
185 		break;
186 	case F_TEXT:
187 		(void)printf("%s", pr->fmt);
188 		break;
189 	case F_U:
190 		conv_u(pr, bp);
191 		break;
192 	case F_UINT:
193 		switch(pr->bcnt) {
194 		case 1:
195 			(void)printf(pr->fmt, (u_quad_t)*bp);
196 			break;
197 		case 2:
198 			bcopy(bp, &u2, sizeof(u2));
199 			(void)printf(pr->fmt, (u_quad_t)u2);
200 			break;
201 		case 4:
202 			bcopy(bp, &u4, sizeof(u4));
203 			(void)printf(pr->fmt, (u_quad_t)u4);
204 			break;
205 		case 8:
206 			bcopy(bp, &u8, sizeof(u8));
207 			(void)printf(pr->fmt, u8);
208 			break;
209 		}
210 		break;
211 	}
212 }
213 
214 void
215 bpad(PR *pr)
216 {
217 	static char const *spec = " -0+#";
218 	char *p1, *p2;
219 
220 	/*
221 	 * Remove all conversion flags; '-' is the only one valid
222 	 * with %s, and it's not useful here.
223 	 */
224 	pr->flags = F_BPAD;
225 	pr->cchar[0] = 's';
226 	pr->cchar[1] = '\0';
227 	for (p1 = pr->fmt; *p1 != '%'; ++p1);
228 	for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
229 	while ((*p2++ = *p1++));
230 }
231 
232 static char **_argv;
233 
234 u_char *
235 get(void)
236 {
237 	static int ateof = 1;
238 	static u_char *curp, *savp;
239 	int n;
240 	int need, nread;
241 	int valid_save = 0;
242 	u_char *tmpp;
243 
244 	if (!curp) {
245 		if ((curp = calloc(1, blocksize)) == NULL)
246 			err(1, NULL);
247 		if ((savp = calloc(1, blocksize)) == NULL)
248 			err(1, NULL);
249 	} else {
250 		tmpp = curp;
251 		curp = savp;
252 		savp = tmpp;
253 		address += blocksize;
254 		valid_save = 1;
255 	}
256 	for (need = blocksize, nread = 0;;) {
257 		/*
258 		 * if read the right number of bytes, or at EOF for one file,
259 		 * and no other files are available, zero-pad the rest of the
260 		 * block and set the end flag.
261 		 */
262 		if (!length || (ateof && !next((char **)NULL))) {
263 			if (odmode && address < skip)
264 				errx(1, "cannot skip past end of input");
265 			if (need == blocksize)
266 				return((u_char *)NULL);
267 			/*
268 			 * XXX bcmp() is not quite right in the presence
269 			 * of multibyte characters.
270 			 */
271 			if (vflag != ALL &&
272 			    valid_save &&
273 			    bcmp(curp, savp, nread) == 0) {
274 				if (vflag != DUP)
275 					(void)printf("*\n");
276 				return((u_char *)NULL);
277 			}
278 			bzero((char *)curp + nread, need);
279 			eaddress = address + nread;
280 			return(curp);
281 		}
282 		n = fread((char *)curp + nread, sizeof(u_char),
283 		    length == -1 ? need : MIN(length, need), stdin);
284 		if (!n) {
285 			if (ferror(stdin))
286 				warn("%s", _argv[-1]);
287 			ateof = 1;
288 			continue;
289 		}
290 		ateof = 0;
291 		if (length != -1)
292 			length -= n;
293 		if (!(need -= n)) {
294 			/*
295 			 * XXX bcmp() is not quite right in the presence
296 			 * of multibyte characters.
297 			 */
298 			if (vflag == ALL || vflag == FIRST ||
299 			    valid_save == 0 ||
300 			    bcmp(curp, savp, blocksize) != 0) {
301 				if (vflag == DUP || vflag == FIRST)
302 					vflag = WAIT;
303 				return(curp);
304 			}
305 			if (vflag == WAIT)
306 				(void)printf("*\n");
307 			vflag = DUP;
308 			address += blocksize;
309 			need = blocksize;
310 			nread = 0;
311 		}
312 		else
313 			nread += n;
314 	}
315 }
316 
317 size_t
318 peek(u_char *buf, size_t nbytes)
319 {
320 	size_t n, nread;
321 	int c;
322 
323 	if (length != -1 && nbytes > (unsigned int)length)
324 		nbytes = length;
325 	nread = 0;
326 	while (nread < nbytes && (c = getchar()) != EOF) {
327 		*buf++ = c;
328 		nread++;
329 	}
330 	n = nread;
331 	while (n-- > 0) {
332 		c = *--buf;
333 		ungetc(c, stdin);
334 	}
335 	return (nread);
336 }
337 
338 int
339 next(char **argv)
340 {
341 	static int done;
342 	int statok;
343 
344 	if (argv) {
345 		_argv = argv;
346 		return(1);
347 	}
348 	for (;;) {
349 		if (*_argv) {
350 			done = 1;
351 			if (!(freopen(*_argv, "r", stdin))) {
352 				warn("%s", *_argv);
353 				exitval = 1;
354 				++_argv;
355 				continue;
356 			}
357 			statok = 1;
358 		} else {
359 			if (done++)
360 				return(0);
361 			statok = 0;
362 		}
363 
364 		if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
365 			err(1, "unable to restrict %s",
366 			    statok ? *_argv : "stdin");
367 
368 		/*
369 		 * We've opened our last input file; enter capsicum sandbox.
370 		 */
371 		if (statok == 0 || *(_argv + 1) == NULL) {
372 			if (cap_enter() < 0 && errno != ENOSYS)
373 				err(1, "unable to enter capability mode");
374 		}
375 
376 		if (skip)
377 			doskip(statok ? *_argv : "stdin", statok);
378 		if (*_argv)
379 			++_argv;
380 		if (!skip)
381 			return(1);
382 	}
383 	/* NOTREACHED */
384 }
385 
386 void
387 doskip(const char *fname, int statok)
388 {
389 	int cnt;
390 	struct stat sb;
391 
392 	if (statok) {
393 		if (fstat(fileno(stdin), &sb))
394 			err(1, "%s", fname);
395 		if (S_ISREG(sb.st_mode) && skip > sb.st_size) {
396 			address += sb.st_size;
397 			skip -= sb.st_size;
398 			return;
399 		}
400 	}
401 	if (statok && S_ISREG(sb.st_mode)) {
402 		if (fseeko(stdin, skip, SEEK_SET))
403 			err(1, "%s", fname);
404 		address += skip;
405 		skip = 0;
406 	} else {
407 		for (cnt = 0; cnt < skip; ++cnt)
408 			if (getchar() == EOF)
409 				break;
410 		address += cnt;
411 		skip -= cnt;
412 	}
413 }
414