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 "includes.h" 30 31 #include <sys/param.h> 32 #include <sys/uio.h> 33 34 #include <errno.h> 35 #include <string.h> 36 37 #include "atomicio.h" 38 39 /* 40 * ensure all of data on socket comes through. f==read || f==vwrite 41 */ 42 size_t 43 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 44 { 45 char *s = _s; 46 size_t pos = 0; 47 ssize_t res; 48 49 while (n > pos) { 50 res = (f) (fd, s + pos, n - pos); 51 switch (res) { 52 case -1: 53 #ifdef EWOULDBLOCK 54 if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) 55 #else 56 if (errno == EINTR || errno == EAGAIN) 57 #endif 58 continue; 59 return 0; 60 case 0: 61 errno = EPIPE; 62 return pos; 63 default: 64 pos += (size_t)res; 65 } 66 } 67 return (pos); 68 } 69 70 /* 71 * ensure all of data on socket comes through. f==readv || f==writev 72 */ 73 size_t 74 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 75 const struct iovec *_iov, int iovcnt) 76 { 77 size_t pos = 0, rem; 78 ssize_t res; 79 struct iovec iov_array[IOV_MAX], *iov = iov_array; 80 81 if (iovcnt > IOV_MAX) { 82 errno = EINVAL; 83 return 0; 84 } 85 /* Make a copy of the iov array because we may modify it below */ 86 memcpy(iov, _iov, iovcnt * sizeof(*_iov)); 87 88 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 89 res = (f) (fd, iov, iovcnt); 90 switch (res) { 91 case -1: 92 if (errno == EINTR || errno == EAGAIN) 93 continue; 94 return 0; 95 case 0: 96 errno = EPIPE; 97 return pos; 98 default: 99 rem = (size_t)res; 100 pos += rem; 101 /* skip completed iov entries */ 102 while (iovcnt > 0 && rem >= iov[0].iov_len) { 103 rem -= iov[0].iov_len; 104 iov++; 105 iovcnt--; 106 } 107 /* This shouldn't happen... */ 108 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 109 errno = EFAULT; 110 return 0; 111 } 112 if (iovcnt == 0) 113 break; 114 /* update pointer in partially complete iov */ 115 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 116 iov[0].iov_len -= rem; 117 } 118 } 119 return pos; 120 } 121