gonzui

    1: /*      $OpenBSD: fdopen.c,v 1.6 2008/04/21 12:28:35 otto Exp $ */
    2: /*-
    3:  * Copyright (c) 1990, 1993
    4:  *      The Regents of the University of California.  All rights reserved.
    5:  *
    6:  * This code is derived from software contributed to Berkeley by
    7:  * Chris Torek.
    8:  *
    9:  * Redistribution and use in source and binary forms, with or without
   10:  * modification, are permitted provided that the following conditions
   11:  * are met:
   12:  * 1. Redistributions of source code must retain the above copyright
   13:  *    notice, this list of conditions and the following disclaimer.
   14:  * 2. Redistributions in binary form must reproduce the above copyright
   15:  *    notice, this list of conditions and the following disclaimer in the
   16:  *    documentation and/or other materials provided with the distribution.
   17:  * 3. Neither the name of the University nor the names of its contributors
   18:  *    may be used to endorse or promote products derived from this software
   19:  *    without specific prior written permission.
   20:  *
   21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31:  * SUCH DAMAGE.
   32:  */
   33: 
   34: #include <sys/types.h>
   35: #include <fcntl.h>
   36: #include <limits.h>
   37: #include <unistd.h>
   38: #include <stdio.h>
   39: #include <errno.h>
   40: #include "local.h"
   41: 
   42: FILE *
   43: fdopen_eno(int fd, const char *mode, int *eno)
   44: {
   45:         FILE *fp;
   46:         int flags, oflags, fdflags, tmp, f;
   47: 
   48:         /* _file is only a short */
   49:         if (fd > SHRT_MAX) {
   50:                 /*errno*/f = EMFILE;
   51:                 goto e1;
   52:         }
   53: 
   54:         if ((flags = __sflags(mode, &oflags)) == 0)
   55:                 { f = EINVAL; goto e1; }
   56: 
   57:         /* Make sure the mode the user wants is a subset of the actual mode. */
   58:         if ((fdflags = __libc_fcntl(fd, F_GETFL, 0)) < 0)
   59:                 { f = fdflags & 0xffff; goto e1; }
   60:         tmp = fdflags & O_ACCMODE;
   61:         if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE))) {
   62:                 /*errno*/f = EINVAL;
   63:                 goto e1;
   64:         }
   65: 
   66:         if ((fp = __sfp()) == NULL)
   67:                 { f = EMFILE; goto e1; }
   68:         fp->_flags = flags;
   69:         /*
   70:          * If opened for appending, but underlying descriptor does not have
   71:          * O_APPEND bit set, assert __SAPP so that __swrite() will lseek to
   72:          * end before each write.
   73:          */
   74:         if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
   75:                 fp->_flags |= __SAPP;
   76:         fp->_file = fd;
   77:         fp->_cookie = fp;
   78:         fp->_read = __sread;
   79:         fp->_write = __swrite;
   80:         fp->_seek = __sseek;
   81:         fp->_close = __sclose;
   82:         return (fp); e1: if (eno) *eno = f; return NULL;
   83: }
   84: FILE *fdopen(int fd, const char *mode){ return fdopen_eno(fd, mode, NULL); }