1 /*	$OpenBSD: uthread_fcntl.c,v 1.7 2003/02/04 22:14:27 marc Exp $	*/
2 /*
3  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by John Birrell.
17  * 4. Neither the name of the author nor the names of any co-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 JOHN BIRRELL 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 AUTHOR 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  * $FreeBSD: uthread_fcntl.c,v 1.8 1999/08/28 00:03:31 peter Exp $
34  */
35 #include <stdarg.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #ifdef _THREAD_SAFE
39 #include <pthread.h>
40 #include "pthread_private.h"
41 
42 int
fcntl(int fd,int cmd,...)43 fcntl(int fd, int cmd,...)
44 {
45 	int             flags = 0;
46 	int		nonblock;
47 	int             oldfd;
48 	int             ret;
49 	va_list         ap;
50 
51 	/* This is a cancellation point: */
52 	_thread_enter_cancellation_point();
53 
54 	/* Lock the file descriptor: */
55 	if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) {
56 		/* Initialise the variable argument list: */
57 		va_start(ap, cmd);
58 
59 		/* Process according to file control command type: */
60 		switch (cmd) {
61 		/* Duplicate a file descriptor: */
62 		case F_DUPFD:
63 			/*
64 			 * Get the file descriptor that the caller wants to
65 			 * use:
66 			 */
67 			oldfd = va_arg(ap, int);
68 
69 			/* Initialise the file descriptor table entry: */
70 			if ((ret = _thread_sys_fcntl(fd, cmd, oldfd)) < 0) {
71 			}
72 			/* Initialise the file descriptor table entry: */
73 			else if (_thread_fd_table_dup(fd, ret) != 0) {
74 				/* Quietly close the file: */
75 				_thread_sys_close(ret);
76 
77 				/* Reset the file descriptor: */
78 				ret = -1;
79 			}
80 			break;
81 		case F_SETFD:
82 			flags = va_arg(ap, int);
83 			ret = _thread_sys_fcntl(fd, cmd, flags);
84 			break;
85 		case F_GETFD:
86 			ret = _thread_sys_fcntl(fd, cmd, 0);
87 			break;
88 		case F_GETFL:
89 			ret = _thread_fd_table[fd]->flags;
90 			break;
91 		case F_SETFL:
92 			/*
93 			 * Get the file descriptor flags passed by the
94 			 * caller:
95 			 */
96 			flags = va_arg(ap, int);
97 
98 			/*
99 			 * Check if the user wants a non-blocking file
100 			 * descriptor:
101 			 */
102 			nonblock = flags & O_NONBLOCK;
103 
104 			/* Set the file descriptor flags: */
105 			if ((ret = _thread_sys_fcntl(fd, cmd, flags | O_NONBLOCK)) != 0) {
106 
107 			/* Get the flags so that we behave like the kernel: */
108 			} else if ((flags = _thread_sys_fcntl(fd,
109 			    F_GETFL, 0)) == -1) {
110 				/* Error getting flags: */
111 				ret = -1;
112 
113 			/*
114 			 * Check if the file descriptor is non-blocking
115 			 * with respect to the user:
116 			 */
117 			} else if (nonblock)
118 				/* A non-blocking descriptor: */
119 				_thread_fd_table[fd]->flags = flags | O_NONBLOCK;
120 			else
121 				/* Save the flags: */
122 				_thread_fd_table[fd]->flags = flags & ~O_NONBLOCK;
123 			break;
124 		default:
125 			/* Might want to make va_arg use a union */
126 			ret = _thread_sys_fcntl(fd, cmd, va_arg(ap, void *));
127 			break;
128 		}
129 
130 		/* Free variable arguments: */
131 		va_end(ap);
132 
133 		/* Unlock the file descriptor: */
134 		_FD_UNLOCK(fd, FD_RDWR);
135 	}
136 
137 	/* No longer in a cancellation point: */
138 	_thread_leave_cancellation_point();
139 
140 	/* Return the completion status: */
141 	return (ret);
142 }
143 #endif
144