[openssh.git] / atomicio.c

/* $OpenBSD: atomicio.c,v 1.23 2006/08/03 03:34:41 deraadt Exp $ */
/*
 * Copyright (c) 2006 Damien Miller. All rights reserved.
 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
 * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

#include <sys/param.h>
#include <sys/uio.h>

#include <errno.h>
#include <string.h>

#include "atomicio.h"

/*
 * ensure all of data on socket comes through. f==read || f==vwrite
 */
size_t
atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
{
	char *s = _s;
	size_t pos = 0;
	ssize_t res;

	while (n > pos) {
		res = (f) (fd, s + pos, n - pos);
		switch (res) {
		case -1:
#ifdef EWOULDBLOCK
			if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
#else
			if (errno == EINTR || errno == EAGAIN)
#endif
				continue;
			return 0;
		case 0:
			errno = EPIPE;
			return pos;
		default:
			pos += (size_t)res;
		}
	}
	return (pos);
}

/*
 * ensure all of data on socket comes through. f==readv || f==writev
 */
size_t
atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
    const struct iovec *_iov, int iovcnt)
{
	size_t pos = 0, rem;
	ssize_t res;
	struct iovec iov_array[IOV_MAX], *iov = iov_array;

	if (iovcnt > IOV_MAX) {
		errno = EINVAL;
		return 0;
	}
	/* Make a copy of the iov array because we may modify it below */
	memcpy(iov, _iov, iovcnt * sizeof(*_iov));

	for (; iovcnt > 0 && iov[0].iov_len > 0;) {
		res = (f) (fd, iov, iovcnt);
		switch (res) {
		case -1:
			if (errno == EINTR || errno == EAGAIN)
				continue;
			return 0;
		case 0:
			errno = EPIPE;
			return pos;
		default:
			rem = (size_t)res;
			pos += rem;
			/* skip completed iov entries */
			while (iovcnt > 0 && rem >= iov[0].iov_len) {
				rem -= iov[0].iov_len;
				iov++;
				iovcnt--;
			}
			/* This shouldn't happen... */
			if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
				errno = EFAULT;
				return 0;
			}
			if (iovcnt == 0)
				break;
			/* update pointer in partially complete iov */
			iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
			iov[0].iov_len -= rem;
		}
	}
	return pos;
}
Commit	Line	Data
31652869	1	/* $OpenBSD: atomicio.c,v 1.23 2006/08/03 03:34:41 deraadt Exp $ */
521b3913	2	/*
68d86b37	3	* Copyright (c) 2006 Damien Miller. All rights reserved.
05624c18	4	* Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
f3c7c613	5	* Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
521b3913	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	27	*/
	28
	29	#include "includes.h"
521b3913	30
536c14e8	31	#include <sys/param.h>
31652869	32	#include <sys/uio.h>
536c14e8	33
028094f4	34	#include <errno.h>
00146caa	35	#include <string.h>
028094f4	36
42f11eb2	37	#include "atomicio.h"
521b3913	38
521b3913	39	/*
4899ccef	40	* ensure all of data on socket comes through. f==read \|\| f==vwrite
521b3913	41	*/
05624c18	42	size_t
433a97dd	43	atomicio(ssize_t (f) (int, void , size_t), int fd, void *_s, size_t n)
521b3913	44	{
610cd5c6	45	char *s = _s;
05624c18	46	size_t pos = 0;
05624c18	47	ssize_t res;
521b3913	48
521b3913	49	while (n > pos) {
35484284	50	res = (f) (fd, s + pos, n - pos);
521b3913	51	switch (res) {
521b3913	52	case -1:
b28e4a3b	53	#ifdef EWOULDBLOCK
	54	if (errno == EINTR \|\| errno == EAGAIN \|\| errno == EWOULDBLOCK)
	55	#else
521b3913	56	if (errno == EINTR \|\| errno == EAGAIN)
b28e4a3b	57	#endif
521b3913	58	continue;
05624c18	59	return 0;
521b3913	60	case 0:
05624c18	61	errno = EPIPE;
05624c18	62	return pos;
521b3913	63	default:
cfb9181c	64	pos += (size_t)res;
521b3913	65	}
	66	}
	67	return (pos);
	68	}
68d86b37	69
	70	/*
	71	* ensure all of data on socket comes through. f==readv \|\| f==writev
	72	*/
	73	size_t
	74	atomiciov(ssize_t (f) (int, const struct iovec , int), int fd,
	75	const struct iovec *_iov, int iovcnt)
	76	{
	77	size_t pos = 0, rem;
	78	ssize_t res;
	79	struct iovec iov_array[IOV_MAX], *iov = iov_array;
	80
	81	if (iovcnt > IOV_MAX) {
	82	errno = EINVAL;
	83	return 0;
	84	}
	85	/* Make a copy of the iov array because we may modify it below */
	86	memcpy(iov, _iov, iovcnt * sizeof(*_iov));
	87
	88	for (; iovcnt > 0 && iov[0].iov_len > 0;) {
	89	res = (f) (fd, iov, iovcnt);
	90	switch (res) {
	91	case -1:
	92	if (errno == EINTR \|\| errno == EAGAIN)
	93	continue;
	94	return 0;
	95	case 0:
	96	errno = EPIPE;
	97	return pos;
	98	default:
	99	rem = (size_t)res;
	100	pos += rem;
	101	/* skip completed iov entries */
	102	while (iovcnt > 0 && rem >= iov[0].iov_len) {
	103	rem -= iov[0].iov_len;
	104	iov++;
	105	iovcnt--;
	106	}
	107	/* This shouldn't happen... */
7bccebd0	108	if (rem > 0 && (iovcnt <= 0 \|\| rem > iov[0].iov_len)) {
68d86b37	109	errno = EFAULT;
	110	return 0;
	111	}
	112	if (iovcnt == 0)
	113	break;
	114	/* update pointer in partially complete iov */
	115	iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
	116	iov[0].iov_len -= rem;
	117	}
	118	}
	119	return pos;
	120	}