lib/libc/stdio/stdio.c

   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  * @(#)stdio.c  8.1 (Berkeley) 6/4/93
  33  * $FreeBSD: src/lib/libc/stdio/stdio.c,v 1.28 2008/05/05 16:14:02 jhb Exp $
  34  * $DragonFly: src/lib/libc/stdio/stdio.c,v 1.7 2005/11/20 11:07:30 swildner Exp $
  35  */
  36
  37 #include "namespace.h"
  38 #include <errno.h>
  39 #include <fcntl.h>
  40 #include <limits.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <unistd.h>
  44 #include "un-namespace.h"
  45 #include "local.h"
  46 #include "priv_stdio.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->pub._fileno, buf, (size_t)n));
  57 }
  58
  59 int
  60 __swrite(void *cookie, const char *buf, int n)
  61 {
  62         FILE *fp = cookie;
  63
  64         return (_write(fp->pub._fileno, 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->pub._fileno, (off_t)offset, whence));
  73 }
  74
  75 int
  76 __sclose(void *cookie)
  77 {
  78
  79         return (_close(((FILE *)cookie)->pub._fileno));
  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->pub._flags & __SOFF) {
  93                         if (fp->_offset <= OFF_MAX - ret)
  94                                 fp->_offset += ret;
  95                         else
  96                                 fp->pub._flags &= ~__SOFF;
  97                 }
  98         } else if (ret < 0)
  99                 fp->pub._flags &= ~__SOFF;
 100         return (ret);
 101 }
 102
 103 int
 104 _swrite(FILE *fp, const char *buf, int n)
 105 {
 106         int ret;
 107         int serrno;
 108
 109         if (fp->pub._flags & __SAPP) {
 110                 serrno = errno;
 111                 if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
 112                     (fp->pub._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->pub._flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
 120                     fp->_offset <= OFF_MAX - ret)
 121                         fp->_offset += ret;
 122                 else
 123                         fp->pub._flags &= ~__SOFF;
 124
 125         } else if (ret < 0)
 126                 fp->pub._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->pub._p = fp->_bf._base;
 153                                 fp->pub._r = 0;
 154                                 fp->pub._flags &= ~__SEOF;
 155                         }
 156                         fp->pub._flags |= __SERR;
 157                         errno = EINVAL;
 158                 } else if (errret == ESPIPE)
 159                         fp->pub._flags &= ~__SAPP;
 160                 fp->pub._flags &= ~__SOFF;
 161                 ret = -1;
 162         } else if (fp->pub._flags & __SOPT) {
 163                 fp->pub._flags |= __SOFF;
 164                 fp->_offset = ret;
 165         }
 166         return (ret);
 167 }