1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993, 1994
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#include <sys/types.h>
33
34#include <capsicum_helpers.h>
35#include <err.h>
36#include <stdlib.h>
37#include <stdio.h>
38
39#include "extern.h"
40
41void
42c_special(int fd1, const char *file1, off_t skip1,
43    int fd2, const char *file2, off_t skip2, off_t limit)
44{
45	int ch1, ch2;
46	off_t byte, line;
47	FILE *fp1, *fp2;
48	int dfound;
49
50	if (caph_limit_stream(fd1, CAPH_READ) < 0)
51		err(ERR_EXIT, "caph_limit_stream(%s)", file1);
52	if (caph_limit_stream(fd2, CAPH_READ) < 0)
53		err(ERR_EXIT, "caph_limit_stream(%s)", file2);
54	if (caph_enter() < 0)
55		err(ERR_EXIT, "unable to enter capability mode");
56
57	if ((fp1 = fdopen(fd1, "r")) == NULL)
58		err(ERR_EXIT, "%s", file1);
59	(void)setvbuf(fp1, NULL, _IOFBF, 65536);
60	if ((fp2 = fdopen(fd2, "r")) == NULL)
61		err(ERR_EXIT, "%s", file2);
62	(void)setvbuf(fp2, NULL, _IOFBF, 65536);
63
64	dfound = 0;
65	while (skip1--)
66		if (getc(fp1) == EOF)
67			goto eof;
68	while (skip2--)
69		if (getc(fp2) == EOF)
70			goto eof;
71
72	for (byte = line = 1; limit == 0 || byte <= limit; ++byte) {
73#ifdef SIGINFO
74		if (info) {
75			(void)fprintf(stderr, "%s %s char %zu line %zu\n",
76			    file1, file2, (size_t)byte, (size_t)line);
77			info = 0;
78		}
79#endif
80		ch1 = getc(fp1);
81		ch2 = getc(fp2);
82		if (ch1 == EOF || ch2 == EOF)
83			break;
84		if (ch1 != ch2) {
85			if (xflag) {
86				dfound = 1;
87				(void)printf("%08llx %02x %02x\n",
88				    (long long)byte - 1, ch1, ch2);
89			} else if (lflag) {
90				dfound = 1;
91				if (bflag)
92					(void)printf("%6lld %3o %c %3o %c\n",
93					    (long long)byte, ch1, ch1, ch2,
94					    ch2);
95				else
96					(void)printf("%6lld %3o %3o\n",
97					    (long long)byte, ch1, ch2);
98			} else {
99				diffmsg(file1, file2, byte, line, ch1, ch2);
100				/* NOTREACHED */
101			}
102		}
103		if (ch1 == '\n')
104			++line;
105	}
106
107eof:	if (ferror(fp1))
108		err(ERR_EXIT, "%s", file1);
109	if (ferror(fp2))
110		err(ERR_EXIT, "%s", file2);
111	if (feof(fp1)) {
112		if (!feof(fp2))
113			eofmsg(file1);
114	} else
115		if (feof(fp2))
116			eofmsg(file2);
117	fclose(fp2);
118	fclose(fp1);
119	if (dfound)
120		exit(DIFF_EXIT);
121}
122