xref: /freebsd/crypto/openssh/atomicio.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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"
27 RCSID("$Id: atomicio.c,v 1.2 2000/02/01 22:32:53 d 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  */
35 ssize_t
36 atomicio(f, fd, s, n)
37 	ssize_t (*f) ();
38 	int fd;
39 	void *s;
40 	size_t n;
41 {
42 	ssize_t res, pos = 0;
43 
44 	while (n > pos) {
45 		res = (f) (fd, s + pos, n - pos);
46 		switch (res) {
47 		case -1:
48 			if (errno == EINTR || errno == EAGAIN)
49 				continue;
50 		case 0:
51 			return (res);
52 		default:
53 			pos += res;
54 		}
55 	}
56 	return (pos);
57 }
58