lib/libc/stdio/vdprintf.c

   1 /*      $NetBSD: vdprintf.c,v 1.2 2011/07/17 20:54:34 joerg Exp $       */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #if defined(LIBC_SCCS) && !defined(lint)
  37 __RCSID("$NetBSD: vdprintf.c,v 1.2 2011/07/17 20:54:34 joerg Exp $");
  38 #endif /* LIBC_SCCS and not lint */
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42
  43 #include <assert.h>
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <unistd.h>
  47 #include <stdio.h>
  48 #include <limits.h>
  49
  50 #include "reentrant.h"
  51 #include "local.h"
  52
  53 #ifdef __weak_alias
  54 __weak_alias(vdprintf,_vdprintf)
  55 #endif
  56
  57 int
  58 vdprintf(int fd, const char * __restrict fmt, va_list ap)
  59 {
  60         FILE f;
  61         struct __sfileext fext;
  62         unsigned char buf[BUFSIZ];
  63         int ret, fdflags, tmp;
  64
  65         _DIAGASSERT(fd != -1);
  66
  67         /*
  68          * File descriptors are a full int, but _file is only a short.
  69          * If we get a valid file descriptor that is greater or equal to
  70          * USHRT_MAX, then the fd will get sign-extended into an
  71          * invalid file descriptor.  Handle this case by failing the
  72          * open. (We treat the short as unsigned, and special-case -1).
  73          */
  74         if (fd >= USHRT_MAX) {
  75                 errno = EMFILE;
  76                 return EOF;
  77         }
  78
  79         if ((fdflags = fcntl(fd, F_GETFL, 0)) == -1)
  80                 return EOF;
  81
  82         tmp = fdflags & O_ACCMODE;
  83         if (tmp != O_RDWR && tmp != O_WRONLY) {
  84                 errno = EINVAL;
  85                 return EOF;
  86         }
  87
  88         if (fdflags & O_NONBLOCK) {
  89                 struct stat st;
  90                 if (fstat(fd, &st) == -1)
  91                         return -1;
  92                 if (!S_ISREG(st.st_mode)) {
  93                         errno = EFTYPE;
  94                         return EOF;
  95                 }
  96         }
  97
  98         _FILEEXT_SETUP(&f, &fext);
  99         __sfpinit(&f);
 100         f._p = buf;
 101         f._w = sizeof(buf);
 102         f._flags = __SWR;
 103         f._file = fd;
 104         f._bf._base = buf;
 105         f._bf._size = sizeof(buf);
 106         f._cookie = &f;
 107         f._read = NULL;
 108         f._write = __swrite;
 109         f._seek = NULL;
 110         f._close = NULL;
 111
 112         if ((ret = vfprintf(&f, fmt, ap)) < 0)
 113                 return ret;
 114
 115         return fflush(&f) ? EOF : ret;
 116 }