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Commit	Line	Data
	1	/* $OpenBSD: atomicio.c,v 1.25 2007/06/25 12:02:27 dtucker Exp $ */
	2	/*
	3	* Copyright (c) 2006 Damien Miller. All rights reserved.
	4	* Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
	5	* Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
	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"
	30
	31	#include <sys/param.h>
	32	#include <sys/uio.h>
	33
	34	#include <errno.h>
	35	#include <poll.h>
	36	#include <string.h>
	37	#include <unistd.h>
	38
	39	#include "atomicio.h"
	40
	41	/*
	42	* ensure all of data on socket comes through. f==read \|\| f==vwrite
	43	*/
	44	size_t
	45	atomicio(ssize_t (f) (int, void , size_t), int fd, void *_s, size_t n)
	46	{
	47	char *s = _s;
	48	size_t pos = 0;
	49	ssize_t res;
	50	struct pollfd pfd;
	51
	52	pfd.fd = fd;
	53	pfd.events = f == read ? POLLIN : POLLOUT;
	54	while (n > pos) {
	55	res = (f) (fd, s + pos, n - pos);
	56	switch (res) {
	57	case -1:
	58	#ifdef EWOULDBLOCK
	59	if (errno == EINTR \|\| errno == EWOULDBLOCK)
	60	#else
	61	if (errno == EINTR)
	62	#endif
	63	continue;
	64	if (errno == EAGAIN) {
	65	(void)poll(&pfd, 1, -1);
	66	continue;
	67	}
	68	return 0;
	69	case 0:
	70	errno = EPIPE;
	71	return pos;
	72	default:
	73	pos += (size_t)res;
	74	}
	75	}
	76	return (pos);
	77	}
	78
	79	/*
	80	* ensure all of data on socket comes through. f==readv \|\| f==writev
	81	*/
	82	size_t
	83	atomiciov(ssize_t (f) (int, const struct iovec , int), int fd,
	84	const struct iovec *_iov, int iovcnt)
	85	{
	86	size_t pos = 0, rem;
	87	ssize_t res;
	88	struct iovec iov_array[IOV_MAX], *iov = iov_array;
	89	struct pollfd pfd;
	90
	91	if (iovcnt > IOV_MAX) {
	92	errno = EINVAL;
	93	return 0;
	94	}
	95	/* Make a copy of the iov array because we may modify it below */
	96	memcpy(iov, _iov, iovcnt * sizeof(*_iov));
	97
	98	pfd.fd = fd;
	99	pfd.events = f == readv ? POLLIN : POLLOUT;
	100	for (; iovcnt > 0 && iov[0].iov_len > 0;) {
	101	res = (f) (fd, iov, iovcnt);
	102	switch (res) {
	103	case -1:
	104	#ifdef EWOULDBLOCK
	105	if (errno == EINTR \|\| errno == EWOULDBLOCK)
	106	#else
	107	if (errno == EINTR)
	108	#endif
	109	continue;
	110	if (errno == EAGAIN) {
	111	(void)poll(&pfd, 1, -1);
	112	continue;
	113	}
	114	return 0;
	115	case 0:
	116	errno = EPIPE;
	117	return pos;
	118	default:
	119	rem = (size_t)res;
	120	pos += rem;
	121	/* skip completed iov entries */
	122	while (iovcnt > 0 && rem >= iov[0].iov_len) {
	123	rem -= iov[0].iov_len;
	124	iov++;
	125	iovcnt--;
	126	}
	127	/* This shouldn't happen... */
	128	if (rem > 0 && (iovcnt <= 0 \|\| rem > iov[0].iov_len)) {
	129	errno = EFAULT;
	130	return 0;
	131	}
	132	if (iovcnt == 0)
	133	break;
	134	/* update pointer in partially complete iov */
	135	iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
	136	iov[0].iov_len -= rem;
	137	}
	138	}
	139	return pos;
	140	}