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 #if 0 39 static char sccsid[] = "@(#)stdio.c 8.1 (Berkeley) 6/4/93"; 40 #endif 41 static const char rcsid[] = 42 "$FreeBSD$"; 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <limits.h> 49 #include <stdio.h> 50 #include <unistd.h> 51 #include "un-namespace.h" 52 #include "local.h" 53 54 /* 55 * Small standard I/O/seek/close functions. 56 * These maintain the `known seek offset' for seek optimisation. 57 */ 58 int 59 __sread(cookie, buf, n) 60 void *cookie; 61 char *buf; 62 int n; 63 { 64 register FILE *fp = cookie; 65 register int ret; 66 67 ret = _read(fp->_file, buf, (size_t)n); 68 /* if the read succeeded, update the current offset */ 69 if (ret >= 0) { 70 if (fp->_flags & __SOFF) { 71 if (fp->_offset > OFF_MAX - ret) { 72 errno = EOVERFLOW; 73 ret = -1; 74 } else { 75 fp->_offset += ret; 76 return (ret); 77 } 78 } else 79 return (ret); 80 } 81 fp->_flags &= ~__SOFF; 82 return (ret); 83 } 84 85 int 86 __swrite(cookie, buf, n) 87 void *cookie; 88 char const *buf; 89 int n; 90 { 91 register FILE *fp = cookie; 92 93 if (fp->_flags & __SAPP) 94 (void) lseek(fp->_file, (off_t)0, SEEK_END); 95 fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */ 96 return (_write(fp->_file, buf, (size_t)n)); 97 } 98 99 fpos_t 100 __sseek(cookie, offset, whence) 101 void *cookie; 102 fpos_t offset; 103 int whence; 104 { 105 register FILE *fp = cookie; 106 register off_t ret; 107 int serrno, errret; 108 109 serrno = errno; 110 errno = 0; 111 ret = lseek(fp->_file, (off_t)offset, whence); 112 errret = errno; 113 if (errno == 0) 114 errno = serrno; 115 /* 116 * Disallow negative seeks per POSIX. 117 * It is needed here to help upper level caller 118 * (fseek) in the cases it can't detect. 119 */ 120 if (ret < 0) { 121 if (errret == 0) { 122 fp->_flags |= __SERR; 123 errno = EINVAL; 124 } 125 fp->_flags &= ~__SOFF; 126 ret = -1; 127 } else { 128 fp->_flags |= __SOFF; 129 fp->_offset = ret; 130 } 131 return (ret); 132 } 133 134 int 135 __sclose(cookie) 136 void *cookie; 137 { 138 139 return (_close(((FILE *)cookie)->_file)); 140 } 141