1 /* $OpenBSD: atomicio.c,v 1.27 2015/01/16 06:40:12 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 #ifdef HAVE_POLL_H 36 #include <poll.h> 37 #else 38 # ifdef HAVE_SYS_POLL_H 39 # include <sys/poll.h> 40 # endif 41 #endif 42 #include <string.h> 43 #include <unistd.h> 44 #include <limits.h> 45 46 #include "atomicio.h" 47 48 /* 49 * ensure all of data on socket comes through. f==read || f==vwrite 50 */ 51 size_t 52 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 53 int (*cb)(void *, size_t), void *cb_arg) 54 { 55 char *s = _s; 56 size_t pos = 0; 57 ssize_t res; 58 struct pollfd pfd; 59 60 #ifndef BROKEN_READ_COMPARISON 61 pfd.fd = fd; 62 pfd.events = f == read ? POLLIN : POLLOUT; 63 #endif 64 while (n > pos) { 65 res = (f) (fd, s + pos, n - pos); 66 switch (res) { 67 case -1: 68 if (errno == EINTR) 69 continue; 70 if (errno == EAGAIN || errno == EWOULDBLOCK) { 71 #ifndef BROKEN_READ_COMPARISON 72 (void)poll(&pfd, 1, -1); 73 #endif 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 91 size_t 92 atomicio(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 */ 100 size_t 101 atomiciov6(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 > 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, iovcnt * sizeof(*_iov)); 116 117 #ifndef BROKEN_READV_COMPARISON 118 pfd.fd = fd; 119 pfd.events = f == readv ? POLLIN : POLLOUT; 120 #endif 121 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 122 res = (f) (fd, iov, iovcnt); 123 switch (res) { 124 case -1: 125 if (errno == EINTR) 126 continue; 127 if (errno == EAGAIN || errno == EWOULDBLOCK) { 128 #ifndef BROKEN_READV_COMPARISON 129 (void)poll(&pfd, 1, -1); 130 #endif 131 continue; 132 } 133 return 0; 134 case 0: 135 errno = EPIPE; 136 return pos; 137 default: 138 rem = (size_t)res; 139 pos += rem; 140 /* skip completed iov entries */ 141 while (iovcnt > 0 && rem >= iov[0].iov_len) { 142 rem -= iov[0].iov_len; 143 iov++; 144 iovcnt--; 145 } 146 /* This shouldn't happen... */ 147 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 148 errno = EFAULT; 149 return 0; 150 } 151 if (iovcnt == 0) 152 break; 153 /* update pointer in partially complete iov */ 154 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 155 iov[0].iov_len -= rem; 156 } 157 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 158 errno = EINTR; 159 return pos; 160 } 161 } 162 return pos; 163 } 164 165 size_t 166 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 167 const struct iovec *_iov, int iovcnt) 168 { 169 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 170 } 171