xref: /freebsd/contrib/netcat/atomicio.c (revision 7a997a696beee31dccebe2d1252d6795e63cbadd)
17a997a69SXin LI /* $OpenBSD: atomicio.c,v 1.8 2006/02/11 19:31:18 otto Exp $ */
27a997a69SXin LI 
38c384020SXin LI /*
47a997a69SXin LI  * Copyright (c) 2005 Anil Madhavapeddy.  All rights served.
58c384020SXin LI  * Copyright (c) 1995,1999 Theo de Raadt.  All rights reserved.
68c384020SXin LI  * All rights reserved.
78c384020SXin LI  *
88c384020SXin LI  * Redistribution and use in source and binary forms, with or without
98c384020SXin LI  * modification, are permitted provided that the following conditions
108c384020SXin LI  * are met:
118c384020SXin LI  * 1. Redistributions of source code must retain the above copyright
128c384020SXin LI  *    notice, this list of conditions and the following disclaimer.
138c384020SXin LI  * 2. Redistributions in binary form must reproduce the above copyright
148c384020SXin LI  *    notice, this list of conditions and the following disclaimer in the
158c384020SXin LI  *    documentation and/or other materials provided with the distribution.
168c384020SXin LI  *
178c384020SXin LI  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
188c384020SXin LI  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
198c384020SXin LI  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
208c384020SXin LI  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
218c384020SXin LI  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
228c384020SXin LI  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
238c384020SXin LI  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
248c384020SXin LI  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
258c384020SXin LI  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
268c384020SXin LI  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
278c384020SXin LI  */
288c384020SXin LI 
298c384020SXin LI #include <sys/types.h>
308c384020SXin LI #include <sys/uio.h>
318c384020SXin LI #include <errno.h>
328c384020SXin LI #include <unistd.h>
337a997a69SXin LI #include "atomicio.h"
348c384020SXin LI 
358c384020SXin LI /*
367a997a69SXin LI  * ensure all of data on socket comes through. f==read || f==vwrite
378c384020SXin LI  */
387a997a69SXin LI size_t
397a997a69SXin LI atomicio(f, fd, _s, n)
407a997a69SXin LI 	ssize_t (*f) (int, void *, size_t);
417a997a69SXin LI 	int fd;
427a997a69SXin LI 	void *_s;
437a997a69SXin LI 	size_t n;
448c384020SXin LI {
458c384020SXin LI 	char *s = _s;
467a997a69SXin LI 	size_t pos = 0;
477a997a69SXin LI 	ssize_t res;
488c384020SXin LI 
498c384020SXin LI 	while (n > pos) {
508c384020SXin LI 		res = (f) (fd, s + pos, n - pos);
518c384020SXin LI 		switch (res) {
528c384020SXin LI 		case -1:
538c384020SXin LI 			if (errno == EINTR || errno == EAGAIN)
548c384020SXin LI 				continue;
557a997a69SXin LI 			return 0;
568c384020SXin LI 		case 0:
577a997a69SXin LI 			errno = EPIPE;
587a997a69SXin LI 			return pos;
598c384020SXin LI 		default:
607a997a69SXin LI 			pos += (size_t)res;
618c384020SXin LI 		}
628c384020SXin LI 	}
637a997a69SXin LI 	return pos;
648c384020SXin LI }
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