1/* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 dtucker 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/uio.h> 30 31#include <errno.h> 32#include <poll.h> 33#include <string.h> 34#include <unistd.h> 35#include <limits.h> 36 37#include "atomicio.h" 38 39/* 40 * ensure all of data on socket comes through. f==read || f==vwrite 41 */ 42size_t 43atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 44 int (*cb)(void *, size_t), void *cb_arg) 45{ 46 char *s = _s; 47 size_t pos = 0; 48 ssize_t res; 49 struct pollfd pfd; 50 51 pfd.fd = fd; 52 pfd.events = f == read ? POLLIN : POLLOUT; 53 while (n > pos) { 54 res = (f) (fd, s + pos, n - pos); 55 switch (res) { 56 case -1: 57 if (errno == EINTR) { 58 /* possible SIGALARM, update callback */ 59 if (cb != NULL && cb(cb_arg, 0) == -1) { 60 errno = EINTR; 61 return pos; 62 } 63 continue; 64 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 65 (void)poll(&pfd, 1, -1); 66 continue; 67 } 68 return 0; 69 case 0: 70 errno = EPIPE; 71 return pos; 72 default: 73 pos += (size_t)res; 74 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 75 errno = EINTR; 76 return pos; 77 } 78 } 79 } 80 return pos; 81} 82 83size_t 84atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 85{ 86 return atomicio6(f, fd, _s, n, NULL, NULL); 87} 88 89/* 90 * ensure all of data on socket comes through. f==readv || f==writev 91 */ 92size_t 93atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 94 const struct iovec *_iov, int iovcnt, 95 int (*cb)(void *, size_t), void *cb_arg) 96{ 97 size_t pos = 0, rem; 98 ssize_t res; 99 struct iovec iov_array[IOV_MAX], *iov = iov_array; 100 struct pollfd pfd; 101 102 if (iovcnt < 0 || iovcnt > IOV_MAX) { 103 errno = EINVAL; 104 return 0; 105 } 106 /* Make a copy of the iov array because we may modify it below */ 107 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); 108 109 pfd.fd = fd; 110 pfd.events = f == readv ? POLLIN : POLLOUT; 111 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 112 res = (f) (fd, iov, iovcnt); 113 switch (res) { 114 case -1: 115 if (errno == EINTR) { 116 /* possible SIGALARM, update callback */ 117 if (cb != NULL && cb(cb_arg, 0) == -1) { 118 errno = EINTR; 119 return pos; 120 } 121 continue; 122 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 123 (void)poll(&pfd, 1, -1); 124 continue; 125 } 126 return 0; 127 case 0: 128 errno = EPIPE; 129 return pos; 130 default: 131 rem = (size_t)res; 132 pos += rem; 133 /* skip completed iov entries */ 134 while (iovcnt > 0 && rem >= iov[0].iov_len) { 135 rem -= iov[0].iov_len; 136 iov++; 137 iovcnt--; 138 } 139 /* This shouldn't happen... */ 140 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 141 errno = EFAULT; 142 return 0; 143 } 144 if (iovcnt == 0) 145 break; 146 /* update pointer in partially complete iov */ 147 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 148 iov[0].iov_len -= rem; 149 } 150 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 151 errno = EINTR; 152 return pos; 153 } 154 } 155 return pos; 156} 157 158size_t 159atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 160 const struct iovec *_iov, int iovcnt) 161{ 162 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 163} 164