atomicio.c revision 58582 
1/*
2 * Copyright (c) 1999 Theo de Raadt
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27RCSID("$Id: atomicio.c,v 1.3 2000/03/16 20:56:13 markus Exp $");
28
29#include "xmalloc.h"
30#include "ssh.h"
31
32/*
33 * ensure all of data on socket comes through. f==read || f==write
34 */
35ssize_t
36atomicio(f, fd, _s, n)
37	ssize_t (*f) ();
38	int fd;
39	void *_s;
40	size_t n;
41{
42	char *s = _s;
43	ssize_t res, pos = 0;
44
45	while (n > pos) {
46		res = (f) (fd, s + pos, n - pos);
47		switch (res) {
48		case -1:
49			if (errno == EINTR || errno == EAGAIN)
50				continue;
51		case 0:
52			return (res);
53		default:
54			pos += res;
55		}
56	}
57	return (pos);
58}
59