1/*
2 * Copyright (c) 2006 Damien Miller. All rights reserved.
3 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
4 * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "includes.h"
29RCSID("$OpenBSD: atomicio.c,v 1.10 2001/05/08 22:48:07 markus Exp $");
30
31#pragma ident	"%Z%%M%	%I%	%E% SMI"
32
33#include "atomicio.h"
34
35/*
36 * ensure all of data on socket comes through. f==read || f==write
37 */
38ssize_t
39atomicio(f, fd, _s, n)
40	ssize_t (*f) ();
41	int fd;
42	void *_s;
43	size_t n;
44{
45	char *s = _s;
46	ssize_t res, pos = 0;
47
48	while (n > pos) {
49		res = (f) (fd, s + pos, n - pos);
50		switch (res) {
51		case -1:
52#ifdef EWOULDBLOCK
53			if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
54#else
55			if (errno == EINTR || errno == EAGAIN)
56#endif
57				continue;
58			/* FALLTHROUGH */
59		case 0:
60			return (res);
61		default:
62			pos += res;
63		}
64	}
65	return (pos);
66}
67
68/*
69 * ensure all of data on socket comes through. f==readv || f==writev
70 */
71size_t
72atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
73    const struct iovec *_iov, int iovcnt)
74{
75	size_t pos = 0, rem;
76	ssize_t res;
77	struct iovec iov_array[IOV_MAX], *iov = iov_array;
78
79	if (iovcnt > IOV_MAX) {
80		errno = EINVAL;
81		return 0;
82	}
83	/* Make a copy of the iov array because we may modify it below */
84	memcpy(iov, _iov, iovcnt * sizeof(*_iov));
85
86	for (; iovcnt > 0 && iov[0].iov_len > 0;) {
87		res = (f) (fd, iov, iovcnt);
88		switch (res) {
89		case -1:
90			if (errno == EINTR || errno == EAGAIN)
91				continue;
92			return 0;
93		case 0:
94			errno = EPIPE;
95			return pos;
96		default:
97			rem = (size_t)res;
98			pos += rem;
99			/* skip completed iov entries */
100			while (iovcnt > 0 && rem >= iov[0].iov_len) {
101				rem -= iov[0].iov_len;
102				iov++;
103				iovcnt--;
104			}
105			/* This shouldn't happen... */
106			if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
107				errno = EFAULT;
108				return 0;
109			}
110			if (iovcnt == 0)
111				break;
112			/* update pointer in partially complete iov */
113			iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
114			iov[0].iov_len -= rem;
115		}
116	}
117	return pos;
118}
119