freebsd-src/contrib/netcat/atomicio.c

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/*
* 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 <sys/types.h>
#include <sys/uio.h>
#include <errno.h>
#include <unistd.h>
ssize_t atomicio(ssize_t (*f)(int, void *, size_t), int fd, void *_s, size_t n);
/*
* ensure all of data on socket comes through. f==read || f==write
*/
ssize_t
atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
{
char *s = _s;
ssize_t res, pos = 0;
while (n > pos) {
res = (f) (fd, s + pos, n - pos);
switch (res) {
case -1:
if (errno == EINTR || errno == EAGAIN)
continue;
case 0:
return (res);
default:
pos += res;
}
}
return (pos);
}