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mirror of https://git.FreeBSD.org/src.git synced 2024-12-04 09:09:56 +00:00
freebsd/crypto/openssh/atomicio.c
Dag-Erling Smørgrav d4af9e693f Upgrade to OpenSSH 5.1p1.
I have worked hard to reduce diffs against the vendor branch.  One
notable change in that respect is that we no longer prefer DSA over
RSA - the reasons for doing so went away years ago.  This may cause
some surprises, as ssh will warn about unknown host keys even for
hosts whose keys haven't changed.

MFC after:	6 weeks
2008-08-01 02:48:36 +00:00

143 lines
3.7 KiB
C

/* $OpenBSD: atomicio.c,v 1.25 2007/06/25 12:02:27 dtucker 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>
#ifdef HAVE_POLL_H
#include <poll.h>
#else
# ifdef HAVE_SYS_POLL_H
# include <sys/poll.h>
# endif
#endif
#include <string.h>
#include <unistd.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;
struct pollfd pfd;
pfd.fd = fd;
pfd.events = f == read ? POLLIN : POLLOUT;
while (n > pos) {
res = (f) (fd, s + pos, n - pos);
switch (res) {
case -1:
if (errno == EINTR)
continue;
if (errno == EAGAIN || errno == EWOULDBLOCK) {
(void)poll(&pfd, 1, -1);
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;
struct pollfd pfd;
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));
#ifndef BROKEN_READV_COMPARISON
pfd.fd = fd;
pfd.events = f == readv ? POLLIN : POLLOUT;
#endif
for (; iovcnt > 0 && iov[0].iov_len > 0;) {
res = (f) (fd, iov, iovcnt);
switch (res) {
case -1:
if (errno == EINTR)
continue;
if (errno == EAGAIN || errno == EWOULDBLOCK) {
#ifndef BROKEN_READV_COMPARISON
(void)poll(&pfd, 1, -1);
#endif
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;
}