xref: /freebsd/lib/libc/stdio/stdio.c (revision 77c1fcec914bae1232762ca0b0462abd6957ff26)
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 <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "namespace.h"
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <limits.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include "un-namespace.h"
49 #include "local.h"
50 
51 /*
52  * Small standard I/O/seek/close functions.
53  */
54 int
55 __sread(void *cookie, char *buf, int n)
56 {
57 	FILE *fp = cookie;
58 
59 	return(_read(fp->_file, buf, (size_t)n));
60 }
61 
62 int
63 __swrite(void *cookie, char const *buf, int n)
64 {
65 	FILE *fp = cookie;
66 
67 	return (_write(fp->_file, buf, (size_t)n));
68 }
69 
70 fpos_t
71 __sseek(void *cookie, fpos_t offset, int whence)
72 {
73 	FILE *fp = cookie;
74 
75 	return (lseek(fp->_file, (off_t)offset, whence));
76 }
77 
78 int
79 __sclose(void *cookie)
80 {
81 
82 	return (_close(((FILE *)cookie)->_file));
83 }
84 
85 /*
86  * Higher level wrappers.
87  */
88 int
89 _sread(FILE *fp, char *buf, int n)
90 {
91 	int ret;
92 
93 	ret = (*fp->_read)(fp->_cookie, buf, n);
94 	if (ret > 0) {
95 		if (fp->_flags & __SOFF) {
96 			if (fp->_offset <= OFF_MAX - ret)
97 				fp->_offset += ret;
98 			else
99 				fp->_flags &= ~__SOFF;
100 		}
101 	} else if (ret < 0)
102 		fp->_flags &= ~__SOFF;
103 	return (ret);
104 }
105 
106 int
107 _swrite(FILE *fp, char const *buf, int n)
108 {
109 	int ret;
110 	int serrno;
111 
112 	if (fp->_flags & __SAPP) {
113 		serrno = errno;
114 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
115 		    (fp->_flags & __SOPT))
116 			return (-1);
117 		errno = serrno;
118 	}
119 	ret = (*fp->_write)(fp->_cookie, buf, n);
120 	/* __SOFF removed even on success in case O_APPEND mode is set. */
121 	if (ret >= 0) {
122 		if ((fp->_flags & __SOFF) && !(fp->_flags2 & __S2OAP) &&
123 		    fp->_offset <= OFF_MAX - ret)
124 			fp->_offset += ret;
125 		else
126 			fp->_flags &= ~__SOFF;
127 
128 	} else if (ret < 0)
129 		fp->_flags &= ~__SOFF;
130 	return (ret);
131 }
132 
133 fpos_t
134 _sseek(FILE *fp, fpos_t offset, int whence)
135 {
136 	fpos_t ret;
137 	int serrno, errret;
138 
139 	serrno = errno;
140 	errno = 0;
141 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
142 	errret = errno;
143 	if (errno == 0)
144 		errno = serrno;
145 	/*
146 	 * Disallow negative seeks per POSIX.
147 	 * It is needed here to help upper level caller
148 	 * in the cases it can't detect.
149 	 */
150 	if (ret < 0) {
151 		if (errret == 0) {
152 			if (offset != 0 || whence != SEEK_CUR) {
153 				if (HASUB(fp))
154 					FREEUB(fp);
155 				fp->_p = fp->_bf._base;
156 				fp->_r = 0;
157 				fp->_flags &= ~__SEOF;
158 			}
159 			fp->_flags |= __SERR;
160 			errno = EINVAL;
161 		} else if (errret == ESPIPE)
162 			fp->_flags &= ~__SAPP;
163 		fp->_flags &= ~__SOFF;
164 		ret = -1;
165 	} else if (fp->_flags & __SOPT) {
166 		fp->_flags |= __SOFF;
167 		fp->_offset = ret;
168 	}
169 	return (ret);
170 }
171 
172 void
173 __stdio_cancel_cleanup(void * arg)
174 {
175 
176 	if (arg != NULL)
177 		_funlockfile((FILE *)arg);
178 }
179