xref: /freebsd/lib/libc/stdio/stdio.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "namespace.h"
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <limits.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include "un-namespace.h"
47 #include "local.h"
48 
49 /*
50  * Small standard I/O/seek/close functions.
51  */
52 int
53 __sread(cookie, buf, n)
54 	void *cookie;
55 	char *buf;
56 	int n;
57 {
58 	FILE *fp = cookie;
59 
60 	return(_read(fp->_file, buf, (size_t)n));
61 }
62 
63 int
64 __swrite(cookie, buf, n)
65 	void *cookie;
66 	char const *buf;
67 	int n;
68 {
69 	FILE *fp = cookie;
70 
71 	return (_write(fp->_file, buf, (size_t)n));
72 }
73 
74 fpos_t
75 __sseek(cookie, offset, whence)
76 	void *cookie;
77 	fpos_t offset;
78 	int whence;
79 {
80 	FILE *fp = cookie;
81 
82 	return (lseek(fp->_file, (off_t)offset, whence));
83 }
84 
85 int
86 __sclose(cookie)
87 	void *cookie;
88 {
89 
90 	return (_close(((FILE *)cookie)->_file));
91 }
92 
93 /*
94  * Higher level wrappers.
95  */
96 int
97 _sread(fp, buf, n)
98 	FILE *fp;
99 	char *buf;
100 	int n;
101 {
102 	int ret;
103 
104 	ret = (*fp->_read)(fp->_cookie, buf, n);
105 	if (ret > 0) {
106 		if (fp->_flags & __SOFF) {
107 			if (fp->_offset <= OFF_MAX - ret)
108 				fp->_offset += ret;
109 			else
110 				fp->_flags &= ~__SOFF;
111 		}
112 	} else if (ret < 0)
113 		fp->_flags &= ~__SOFF;
114 	return (ret);
115 }
116 
117 int
118 _swrite(fp, buf, n)
119 	FILE *fp;
120 	char const *buf;
121 	int n;
122 {
123 	int ret;
124 	int serrno;
125 
126 	if (fp->_flags & __SAPP) {
127 		serrno = errno;
128 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
129 		    (fp->_flags & __SOPT))
130 			return (-1);
131 		errno = serrno;
132 	}
133 	ret = (*fp->_write)(fp->_cookie, buf, n);
134 	/* __SOFF removed even on success in case O_APPEND mode is set. */
135 	if (ret >= 0) {
136 		if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
137 		    fp->_offset <= OFF_MAX - ret)
138 			fp->_offset += ret;
139 		else
140 			fp->_flags &= ~__SOFF;
141 
142 	} else if (ret < 0)
143 		fp->_flags &= ~__SOFF;
144 	return (ret);
145 }
146 
147 fpos_t
148 _sseek(fp, offset, whence)
149 	FILE *fp;
150 	fpos_t offset;
151 	int whence;
152 {
153 	fpos_t ret;
154 	int serrno, errret;
155 
156 	serrno = errno;
157 	errno = 0;
158 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
159 	errret = errno;
160 	if (errno == 0)
161 		errno = serrno;
162 	/*
163 	 * Disallow negative seeks per POSIX.
164 	 * It is needed here to help upper level caller
165 	 * in the cases it can't detect.
166 	 */
167 	if (ret < 0) {
168 		if (errret == 0) {
169 			if (offset != 0 || whence != SEEK_CUR) {
170 				if (HASUB(fp))
171 					FREEUB(fp);
172 				fp->_p = fp->_bf._base;
173 				fp->_r = 0;
174 				fp->_flags &= ~__SEOF;
175 			}
176 			fp->_flags |= __SERR;
177 			errno = EINVAL;
178 		} else if (errret == ESPIPE)
179 			fp->_flags &= ~__SAPP;
180 		fp->_flags &= ~__SOFF;
181 		ret = -1;
182 	} else if (fp->_flags & __SOPT) {
183 		fp->_flags |= __SOFF;
184 		fp->_offset = ret;
185 	}
186 	return (ret);
187 }
188