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. 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 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)fdopen.c 8.1 (Berkeley) 6/4/93"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "namespace.h" 40 #include <sys/types.h> 41 #include <fcntl.h> 42 #include <unistd.h> 43 #include <stdio.h> 44 #include <errno.h> 45 #include <limits.h> 46 #include "un-namespace.h" 47 #include "local.h" 48 49 FILE * 50 fdopen(int fd, const char *mode) 51 { 52 FILE *fp; 53 int flags, oflags, fdflags, tmp; 54 55 /* 56 * File descriptors are a full int, but _file is only a short. 57 * If we get a valid file descriptor that is greater than 58 * SHRT_MAX, then the fd will get sign-extended into an 59 * invalid file descriptor. Handle this case by failing the 60 * open. 61 */ 62 if (fd > SHRT_MAX) { 63 errno = EMFILE; 64 return (NULL); 65 } 66 67 if ((flags = __sflags(mode, &oflags)) == 0) 68 return (NULL); 69 70 /* Make sure the mode the user wants is a subset of the actual mode. */ 71 if ((fdflags = _fcntl(fd, F_GETFL, 0)) < 0) 72 return (NULL); 73 tmp = fdflags & O_ACCMODE; 74 if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE))) { 75 errno = EINVAL; 76 return (NULL); 77 } 78 79 if ((fp = __sfp()) == NULL) 80 return (NULL); 81 82 if ((oflags & O_CLOEXEC) && _fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) { 83 fp->_flags = 0; 84 return (NULL); 85 } 86 87 fp->_flags = flags; 88 /* 89 * If opened for appending, but underlying descriptor does not have 90 * O_APPEND bit set, assert __SAPP so that __swrite() caller 91 * will _sseek() to the end before write. 92 */ 93 if ((oflags & O_APPEND) && !(fdflags & O_APPEND)) 94 fp->_flags |= __SAPP; 95 fp->_file = fd; 96 fp->_cookie = fp; 97 fp->_read = __sread; 98 fp->_write = __swrite; 99 fp->_seek = __sseek; 100 fp->_close = __sclose; 101 return (fp); 102 } 103