xref: /netbsd-src/external/mpl/bind/dist/lib/isc/stdio.c (revision bcda20f65a8566e103791ec395f7f499ef322704)
1 /*	$NetBSD: stdio.c,v 1.3 2025/01/26 16:25:38 christos Exp $	*/
2 
3 /*
4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5  *
6  * SPDX-License-Identifier: MPL-2.0
7  *
8  * This Source Code Form is subject to the terms of the Mozilla Public
9  * License, v. 2.0. If a copy of the MPL was not distributed with this
10  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11  *
12  * See the COPYRIGHT file distributed with this work for additional
13  * information regarding copyright ownership.
14  */
15 
16 #include <errno.h>
17 #include <sys/stat.h>
18 #include <unistd.h>
19 
20 #include <isc/stdio.h>
21 #include <isc/util.h>
22 
23 #include "errno2result.h"
24 
25 isc_result_t
26 isc_stdio_open(const char *filename, const char *mode, FILE **fp) {
27 	FILE *f;
28 
29 	f = fopen(filename, mode);
30 	if (f == NULL) {
31 		return isc__errno2result(errno);
32 	}
33 	*fp = f;
34 	return ISC_R_SUCCESS;
35 }
36 
37 isc_result_t
38 isc_stdio_close(FILE *f) {
39 	int r;
40 
41 	r = fclose(f);
42 	if (r == 0) {
43 		return ISC_R_SUCCESS;
44 	} else {
45 		return isc__errno2result(errno);
46 	}
47 }
48 
49 isc_result_t
50 isc_stdio_seek(FILE *f, off_t offset, int whence) {
51 	int r;
52 
53 	r = fseeko(f, offset, whence);
54 	if (r == 0) {
55 		return ISC_R_SUCCESS;
56 	} else {
57 		return isc__errno2result(errno);
58 	}
59 }
60 
61 isc_result_t
62 isc_stdio_tell(FILE *f, off_t *offsetp) {
63 	off_t r;
64 
65 	REQUIRE(offsetp != NULL);
66 
67 	r = ftello(f);
68 	if (r >= 0) {
69 		*offsetp = r;
70 		return ISC_R_SUCCESS;
71 	} else {
72 		return isc__errno2result(errno);
73 	}
74 }
75 
76 isc_result_t
77 isc_stdio_read(void *ptr, size_t size, size_t nmemb, FILE *f, size_t *nret) {
78 	isc_result_t result = ISC_R_SUCCESS;
79 	size_t r;
80 
81 	clearerr(f);
82 	r = fread(ptr, size, nmemb, f);
83 	if (r != nmemb) {
84 		if (feof(f)) {
85 			result = ISC_R_EOF;
86 		} else {
87 			result = isc__errno2result(errno);
88 		}
89 	}
90 	SET_IF_NOT_NULL(nret, r);
91 	return result;
92 }
93 
94 isc_result_t
95 isc_stdio_write(const void *ptr, size_t size, size_t nmemb, FILE *f,
96 		size_t *nret) {
97 	isc_result_t result = ISC_R_SUCCESS;
98 	size_t r;
99 
100 	clearerr(f);
101 	r = fwrite(ptr, size, nmemb, f);
102 	if (r != nmemb) {
103 		result = isc__errno2result(errno);
104 	}
105 	SET_IF_NOT_NULL(nret, r);
106 	return result;
107 }
108 
109 isc_result_t
110 isc_stdio_flush(FILE *f) {
111 	int r;
112 
113 	r = fflush(f);
114 	if (r == 0) {
115 		return ISC_R_SUCCESS;
116 	} else {
117 		return isc__errno2result(errno);
118 	}
119 }
120 
121 /*
122  * OpenBSD has deprecated ENOTSUP in favor of EOPNOTSUPP.
123  */
124 #if defined(EOPNOTSUPP) && !defined(ENOTSUP)
125 #define ENOTSUP EOPNOTSUPP
126 #endif /* if defined(EOPNOTSUPP) && !defined(ENOTSUP) */
127 
128 isc_result_t
129 isc_stdio_sync(FILE *f) {
130 	struct stat buf;
131 	int r;
132 
133 	if (fstat(fileno(f), &buf) != 0) {
134 		return isc__errno2result(errno);
135 	}
136 
137 	/*
138 	 * Only call fsync() on regular files.
139 	 */
140 	if ((buf.st_mode & S_IFMT) != S_IFREG) {
141 		return ISC_R_SUCCESS;
142 	}
143 
144 	r = fsync(fileno(f));
145 	if (r == 0) {
146 		return ISC_R_SUCCESS;
147 	} else {
148 		return isc__errno2result(errno);
149 	}
150 }
151