1 /* $OpenBSD: atomicio.c,v 1.9 2007/09/07 14:50:44 tobias Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Damien Miller. All rights reserved. 5 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved. 6 * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/param.h> 31 32 #include <errno.h> 33 #include <poll.h> 34 #include <unistd.h> 35 36 #include "atomicio.h" 37 38 /* 39 * ensure all of data on socket comes through. f==read || f==vwrite 40 */ 41 size_t 42 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 43 { 44 char *s = _s; 45 size_t pos = 0; 46 ssize_t res; 47 struct pollfd pfd; 48 49 pfd.fd = fd; 50 pfd.events = f == read ? POLLIN : POLLOUT; 51 while (n > pos) { 52 res = (f) (fd, s + pos, n - pos); 53 switch (res) { 54 case -1: 55 if (errno == EINTR) 56 continue; 57 if (errno == EAGAIN) { 58 (void) poll(&pfd, 1, -1); 59 continue; 60 } 61 return (0); 62 case 0: 63 errno = EPIPE; 64 return (pos); 65 default: 66 pos += (size_t)res; 67 } 68 } 69 return (pos); 70 } 71