xref: /freebsd/lib/libc/stdio/stdio.c (revision 035e325c81b75ea3b5c878c55cc133672b6ac06d)
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  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include "namespace.h"
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <limits.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 #include "un-namespace.h"
51 #include "local.h"
52 
53 /*
54  * Small standard I/O/seek/close functions.
55  */
56 int
57 __sread(cookie, buf, n)
58 	void *cookie;
59 	char *buf;
60 	int n;
61 {
62 	FILE *fp = cookie;
63 
64 	return(_read(fp->_file, buf, (size_t)n));
65 }
66 
67 int
68 __swrite(cookie, buf, n)
69 	void *cookie;
70 	char const *buf;
71 	int n;
72 {
73 	FILE *fp = cookie;
74 
75 	return (_write(fp->_file, buf, (size_t)n));
76 }
77 
78 fpos_t
79 __sseek(cookie, offset, whence)
80 	void *cookie;
81 	fpos_t offset;
82 	int whence;
83 {
84 	FILE *fp = cookie;
85 
86 	return (lseek(fp->_file, (off_t)offset, whence));
87 }
88 
89 int
90 __sclose(cookie)
91 	void *cookie;
92 {
93 
94 	return (_close(((FILE *)cookie)->_file));
95 }
96 
97 /*
98  * Higher level wrappers.
99  */
100 int
101 _sread(fp, buf, n)
102 	FILE *fp;
103 	char *buf;
104 	int n;
105 {
106 	int ret;
107 
108 	ret = (*fp->_read)(fp->_cookie, buf, n);
109 	if (ret > 0) {
110 		if (fp->_flags & __SOFF) {
111 			if (fp->_offset <= OFF_MAX - ret)
112 				fp->_offset += ret;
113 			else
114 				fp->_flags &= ~__SOFF;
115 		}
116 	} else if (ret < 0)
117 		fp->_flags &= ~__SOFF;
118 	return (ret);
119 }
120 
121 int
122 _swrite(fp, buf, n)
123 	FILE *fp;
124 	char const *buf;
125 	int n;
126 {
127 	int ret;
128 	int serrno;
129 
130 	if (fp->_flags & __SAPP) {
131 		serrno = errno;
132 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
133 		    (fp->_flags & __SOPT))
134 			return (-1);
135 		errno = serrno;
136 	}
137 	ret = (*fp->_write)(fp->_cookie, buf, n);
138 	/* __SOFF removed even on success in case O_APPEND mode is set. */
139 	if (ret >= 0) {
140 		if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
141 		    fp->_offset <= OFF_MAX - ret)
142 			fp->_offset += ret;
143 		else
144 			fp->_flags &= ~__SOFF;
145 
146 	} else if (ret < 0)
147 		fp->_flags &= ~__SOFF;
148 	return (ret);
149 }
150 
151 fpos_t
152 _sseek(fp, offset, whence)
153 	FILE *fp;
154 	fpos_t offset;
155 	int whence;
156 {
157 	fpos_t ret;
158 	int serrno, errret;
159 
160 	serrno = errno;
161 	errno = 0;
162 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
163 	errret = errno;
164 	if (errno == 0)
165 		errno = serrno;
166 	/*
167 	 * Disallow negative seeks per POSIX.
168 	 * It is needed here to help upper level caller
169 	 * in the cases it can't detect.
170 	 */
171 	if (ret < 0) {
172 		if (errret == 0) {
173 			if (offset != 0 || whence != SEEK_CUR) {
174 				if (HASUB(fp))
175 					FREEUB(fp);
176 				fp->_p = fp->_bf._base;
177 				fp->_r = 0;
178 				fp->_flags &= ~__SEOF;
179 			}
180 			fp->_flags |= __SERR;
181 			errno = EINVAL;
182 		} else if (errret == ESPIPE)
183 			fp->_flags &= ~__SAPP;
184 		fp->_flags &= ~__SOFF;
185 		ret = -1;
186 	} else if (fp->_flags & __SOPT) {
187 		fp->_flags |= __SOFF;
188 		fp->_offset = ret;
189 	}
190 	return (ret);
191 }
192