xref: /freebsd/lib/libc/stdio/stdio.c (revision 4c9a0adad18263ec8725d9bfc5f560c6ad1da8bd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
38 #include "namespace.h"
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 #include "un-namespace.h"
46 #include "local.h"
47 
48 /*
49  * Small standard I/O/seek/close functions.
50  */
51 int
52 __sread(void *cookie, char *buf, int n)
53 {
54 	FILE *fp = cookie;
55 
56 	return(_read(fp->_file, buf, (size_t)n));
57 }
58 
59 int
60 __swrite(void *cookie, char const *buf, int n)
61 {
62 	FILE *fp = cookie;
63 
64 	return (_write(fp->_file, buf, (size_t)n));
65 }
66 
67 fpos_t
68 __sseek(void *cookie, fpos_t offset, int whence)
69 {
70 	FILE *fp = cookie;
71 
72 	return (lseek(fp->_file, (off_t)offset, whence));
73 }
74 
75 int
76 __sclose(void *cookie)
77 {
78 
79 	return (_close(((FILE *)cookie)->_file));
80 }
81 
82 /*
83  * Higher level wrappers.
84  */
85 int
86 _sread(FILE *fp, char *buf, int n)
87 {
88 	int ret;
89 
90 	ret = (*fp->_read)(fp->_cookie, buf, n);
91 	if (ret > 0) {
92 		if (fp->_flags & __SOFF) {
93 			if (fp->_offset <= OFF_MAX - ret)
94 				fp->_offset += ret;
95 			else
96 				fp->_flags &= ~__SOFF;
97 		}
98 	} else if (ret < 0)
99 		fp->_flags &= ~__SOFF;
100 	return (ret);
101 }
102 
103 int
104 _swrite(FILE *fp, char const *buf, int n)
105 {
106 	int ret;
107 	int serrno;
108 
109 	if (fp->_flags & __SAPP) {
110 		serrno = errno;
111 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
112 		    (fp->_flags & __SOPT))
113 			return (-1);
114 		errno = serrno;
115 	}
116 	ret = (*fp->_write)(fp->_cookie, buf, n);
117 	/* __SOFF removed even on success in case O_APPEND mode is set. */
118 	if (ret >= 0) {
119 		if ((fp->_flags & __SOFF) && !(fp->_flags2 & __S2OAP) &&
120 		    fp->_offset <= OFF_MAX - ret)
121 			fp->_offset += ret;
122 		else
123 			fp->_flags &= ~__SOFF;
124 
125 	} else if (ret < 0)
126 		fp->_flags &= ~__SOFF;
127 	return (ret);
128 }
129 
130 fpos_t
131 _sseek(FILE *fp, fpos_t offset, int whence)
132 {
133 	fpos_t ret;
134 	int serrno, errret;
135 
136 	serrno = errno;
137 	errno = 0;
138 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
139 	errret = errno;
140 	if (errno == 0)
141 		errno = serrno;
142 	/*
143 	 * Disallow negative seeks per POSIX.
144 	 * It is needed here to help upper level caller
145 	 * in the cases it can't detect.
146 	 */
147 	if (ret < 0) {
148 		if (errret == 0) {
149 			if (offset != 0 || whence != SEEK_CUR) {
150 				if (HASUB(fp))
151 					FREEUB(fp);
152 				fp->_p = fp->_bf._base;
153 				fp->_r = 0;
154 				fp->_flags &= ~__SEOF;
155 			}
156 			fp->_flags |= __SERR;
157 			errno = EINVAL;
158 		} else if (errret == ESPIPE)
159 			fp->_flags &= ~__SAPP;
160 		fp->_flags &= ~__SOFF;
161 		ret = -1;
162 	} else if (fp->_flags & __SOPT) {
163 		fp->_flags |= __SOFF;
164 		fp->_offset = ret;
165 	}
166 	return (ret);
167 }
168 
169 void
170 __stdio_cancel_cleanup(void * arg)
171 {
172 
173 	if (arg != NULL)
174 		_funlockfile((FILE *)arg);
175 }
176