1 /* $OpenBSD: atomicio.c,v 1.23 2006/08/03 03:34:41 deraadt 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 <sys/param.h> 30 #include <sys/uio.h> 31 32 #include <errno.h> 33 #include <string.h> 34 35 #include "atomicio.h" 36 37 /* 38 * ensure all of data on socket comes through. f==read || f==vwrite 39 */ 40 size_t 41 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 42 { 43 char *s = _s; 44 size_t pos = 0; 45 ssize_t res; 46 47 while (n > pos) { 48 res = (f) (fd, s + pos, n - pos); 49 switch (res) { 50 case -1: 51 if (errno == EINTR || errno == EAGAIN) 52 continue; 53 return 0; 54 case 0: 55 errno = EPIPE; 56 return pos; 57 default: 58 pos += (size_t)res; 59 } 60 } 61 return (pos); 62 } 63 64 /* 65 * ensure all of data on socket comes through. f==readv || f==writev 66 */ 67 size_t 68 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 69 const struct iovec *_iov, int iovcnt) 70 { 71 size_t pos = 0, rem; 72 ssize_t res; 73 struct iovec iov_array[IOV_MAX], *iov = iov_array; 74 75 if (iovcnt > IOV_MAX) { 76 errno = EINVAL; 77 return 0; 78 } 79 /* Make a copy of the iov array because we may modify it below */ 80 memcpy(iov, _iov, iovcnt * sizeof(*_iov)); 81 82 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 83 res = (f) (fd, iov, iovcnt); 84 switch (res) { 85 case -1: 86 if (errno == EINTR || errno == EAGAIN) 87 continue; 88 return 0; 89 case 0: 90 errno = EPIPE; 91 return pos; 92 default: 93 rem = (size_t)res; 94 pos += rem; 95 /* skip completed iov entries */ 96 while (iovcnt > 0 && rem >= iov[0].iov_len) { 97 rem -= iov[0].iov_len; 98 iov++; 99 iovcnt--; 100 } 101 /* This shouldn't happen... */ 102 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 103 errno = EFAULT; 104 return 0; 105 } 106 if (iovcnt == 0) 107 break; 108 /* update pointer in partially complete iov */ 109 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 110 iov[0].iov_len -= rem; 111 } 112 } 113 return pos; 114 } 115