1/* $NetBSD: atomicio.c,v 1.9 2019/04/20 17:16:40 christos Exp $ */ 2/* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 dtucker Exp $ */ 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 "includes.h" 31__RCSID("$NetBSD: atomicio.c,v 1.9 2019/04/20 17:16:40 christos Exp $"); 32#include <sys/param.h> 33#include <sys/uio.h> 34 35#include <errno.h> 36#include <poll.h> 37#include <string.h> 38#include <unistd.h> 39#include <limits.h> 40 41#include "atomicio.h" 42 43/* 44 * ensure all of data on socket comes through. f==read || f==vwrite 45 */ 46size_t 47atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 48 int (*cb)(void *, size_t), void *cb_arg) 49{ 50 char *s = _s; 51 size_t pos = 0; 52 ssize_t res; 53 struct pollfd pfd; 54 55 pfd.fd = fd; 56 /* 57 * check for vwrite instead of read to avoid read being renamed 58 * by SSP issues 59 */ 60 pfd.events = f == vwrite ? POLLOUT : POLLIN; 61 while (n > pos) { 62 res = (f) (fd, s + pos, n - pos); 63 switch (res) { 64 case -1: 65 if (errno == EINTR) { 66 /* possible SIGALARM, update callback */ 67 if (cb != NULL && cb(cb_arg, 0) == -1) { 68 errno = EINTR; 69 return pos; 70 } 71 continue; 72 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 73 (void)poll(&pfd, 1, -1); 74 continue; 75 } 76 return 0; 77 case 0: 78 errno = EPIPE; 79 return pos; 80 default: 81 pos += (size_t)res; 82 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 83 errno = EINTR; 84 return pos; 85 } 86 } 87 } 88 return pos; 89} 90 91size_t 92atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 93{ 94 return atomicio6(f, fd, _s, n, NULL, NULL); 95} 96 97/* 98 * ensure all of data on socket comes through. f==readv || f==writev 99 */ 100size_t 101atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 102 const struct iovec *_iov, int iovcnt, 103 int (*cb)(void *, size_t), void *cb_arg) 104{ 105 size_t pos = 0, rem; 106 ssize_t res; 107 struct iovec iov_array[IOV_MAX], *iov = iov_array; 108 struct pollfd pfd; 109 110 if (iovcnt < 0 || iovcnt > IOV_MAX) { 111 errno = EINVAL; 112 return 0; 113 } 114 /* Make a copy of the iov array because we may modify it below */ 115 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); 116 117 pfd.fd = fd; 118 pfd.events = f == readv ? POLLIN : POLLOUT; 119 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 120 res = (f) (fd, iov, iovcnt); 121 switch (res) { 122 case -1: 123 if (errno == EINTR) { 124 /* possible SIGALARM, update callback */ 125 if (cb != NULL && cb(cb_arg, 0) == -1) { 126 errno = EINTR; 127 return pos; 128 } 129 continue; 130 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 131 (void)poll(&pfd, 1, -1); 132 continue; 133 } 134 return 0; 135 case 0: 136 errno = EPIPE; 137 return pos; 138 default: 139 rem = (size_t)res; 140 pos += rem; 141 /* skip completed iov entries */ 142 while (iovcnt > 0 && rem >= iov[0].iov_len) { 143 rem -= iov[0].iov_len; 144 iov++; 145 iovcnt--; 146 } 147 /* This shouldn't happen... */ 148 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 149 errno = EFAULT; 150 return 0; 151 } 152 if (iovcnt == 0) 153 break; 154 /* update pointer in partially complete iov */ 155 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 156 iov[0].iov_len -= rem; 157 } 158 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 159 errno = EINTR; 160 return pos; 161 } 162 } 163 return pos; 164} 165 166size_t 167atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 168 const struct iovec *_iov, int iovcnt) 169{ 170 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 171} 172