xref: /freebsd/crypto/openssh/atomicio.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
1 /*
2  * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
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("$OpenBSD: atomicio.c,v 1.10 2001/05/08 22:48:07 markus Exp $");
28 
29 #include "atomicio.h"
30 
31 /*
32  * ensure all of data on socket comes through. f==read || f==write
33  */
34 ssize_t
35 atomicio(f, fd, _s, n)
36 	ssize_t (*f) ();
37 	int fd;
38 	void *_s;
39 	size_t n;
40 {
41 	char *s = _s;
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 #ifdef EWOULDBLOCK
49 			if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
50 #else
51 			if (errno == EINTR || errno == EAGAIN)
52 #endif
53 				continue;
54 		case 0:
55 			return (res);
56 		default:
57 			pos += res;
58 		}
59 	}
60 	return (pos);
61 }
62