1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 "namespace.h" 36 #include <sys/types.h> 37 #include <fcntl.h> 38 #include <unistd.h> 39 #include <stdio.h> 40 #include <errno.h> 41 #include <limits.h> 42 #include "un-namespace.h" 43 #include "local.h" 44 45 FILE * 46 fdopen(int fd, const char *mode) 47 { 48 FILE *fp; 49 int flags, oflags, fdflags, tmp; 50 51 /* 52 * File descriptors are a full int, but _file is only a short. 53 * If we get a valid file descriptor that is greater than 54 * SHRT_MAX, then the fd will get sign-extended into an 55 * invalid file descriptor. Handle this case by failing the 56 * open. 57 */ 58 if (fd > SHRT_MAX) { 59 errno = EMFILE; 60 return (NULL); 61 } 62 63 if ((flags = __sflags(mode, &oflags)) == 0) 64 return (NULL); 65 66 /* Make sure the mode the user wants is a subset of the actual mode. */ 67 if ((fdflags = _fcntl(fd, F_GETFL, 0)) < 0) 68 return (NULL); 69 /* Work around incorrect O_ACCMODE. */ 70 tmp = fdflags & (O_ACCMODE | O_EXEC); 71 if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE))) { 72 errno = EINVAL; 73 return (NULL); 74 } 75 76 if ((fp = __sfp()) == NULL) 77 return (NULL); 78 79 if ((oflags & O_CLOEXEC) && _fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) { 80 fp->_flags = 0; 81 return (NULL); 82 } 83 84 fp->_flags = flags; 85 /* 86 * If opened for appending, but underlying descriptor does not have 87 * O_APPEND bit set, assert __SAPP so that __swrite() caller 88 * will _sseek() to the end before write. 89 */ 90 if (fdflags & O_APPEND) 91 fp->_flags2 |= __S2OAP; 92 else if (oflags & O_APPEND) 93 fp->_flags |= __SAPP; 94 fp->_file = fd; 95 fp->_cookie = fp; 96 fp->_read = __sread; 97 fp->_write = __swrite; 98 fp->_seek = __sseek; 99 fp->_close = __sclose; 100 return (fp); 101 } 102