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 "includes.h" 30 31 #include <sys/uio.h> 32 33 #include <errno.h> 34 #ifdef HAVE_POLL_H 35 #include <poll.h> 36 #else 37 # ifdef HAVE_SYS_POLL_H 38 # include <sys/poll.h> 39 # endif 40 #endif 41 #include <string.h> 42 #include <unistd.h> 43 #include <limits.h> 44 45 #include "atomicio.h" 46 47 /* 48 * ensure all of data on socket comes through. f==read || f==vwrite 49 */ 50 size_t 51 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 52 int (*cb)(void *, size_t), void *cb_arg) 53 { 54 char *s = _s; 55 size_t pos = 0; 56 ssize_t res; 57 struct pollfd pfd; 58 59 pfd.fd = fd; 60 #ifndef BROKEN_READ_COMPARISON 61 pfd.events = f == read ? POLLIN : POLLOUT; 62 #else 63 pfd.events = POLLIN|POLLOUT; 64 #endif 65 while (n > pos) { 66 res = (f) (fd, s + pos, n - pos); 67 switch (res) { 68 case -1: 69 if (errno == EINTR) { 70 /* possible SIGALARM, update callback */ 71 if (cb != NULL && cb(cb_arg, 0) == -1) { 72 errno = EINTR; 73 return pos; 74 } 75 continue; 76 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 77 (void)poll(&pfd, 1, -1); 78 continue; 79 } 80 return 0; 81 case 0: 82 errno = EPIPE; 83 return pos; 84 default: 85 pos += (size_t)res; 86 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 87 errno = EINTR; 88 return pos; 89 } 90 } 91 } 92 return pos; 93 } 94 95 size_t 96 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 97 { 98 return atomicio6(f, fd, _s, n, NULL, NULL); 99 } 100 101 /* 102 * ensure all of data on socket comes through. f==readv || f==writev 103 */ 104 size_t 105 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 106 const struct iovec *_iov, int iovcnt, 107 int (*cb)(void *, size_t), void *cb_arg) 108 { 109 size_t pos = 0, rem; 110 ssize_t res; 111 struct iovec iov_array[IOV_MAX], *iov = iov_array; 112 struct pollfd pfd; 113 114 if (iovcnt < 0 || iovcnt > IOV_MAX) { 115 errno = EINVAL; 116 return 0; 117 } 118 /* Make a copy of the iov array because we may modify it below */ 119 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); 120 121 pfd.fd = fd; 122 #ifndef BROKEN_READV_COMPARISON 123 pfd.events = f == readv ? POLLIN : POLLOUT; 124 #else 125 pfd.events = POLLIN|POLLOUT; 126 #endif 127 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 128 res = (f) (fd, iov, iovcnt); 129 switch (res) { 130 case -1: 131 if (errno == EINTR) { 132 /* possible SIGALARM, update callback */ 133 if (cb != NULL && cb(cb_arg, 0) == -1) { 134 errno = EINTR; 135 return pos; 136 } 137 continue; 138 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 139 (void)poll(&pfd, 1, -1); 140 continue; 141 } 142 return 0; 143 case 0: 144 errno = EPIPE; 145 return pos; 146 default: 147 rem = (size_t)res; 148 pos += rem; 149 /* skip completed iov entries */ 150 while (iovcnt > 0 && rem >= iov[0].iov_len) { 151 rem -= iov[0].iov_len; 152 iov++; 153 iovcnt--; 154 } 155 /* This shouldn't happen... */ 156 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 157 errno = EFAULT; 158 return 0; 159 } 160 if (iovcnt == 0) 161 break; 162 /* update pointer in partially complete iov */ 163 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 164 iov[0].iov_len -= rem; 165 } 166 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 167 errno = EINTR; 168 return pos; 169 } 170 } 171 return pos; 172 } 173 174 size_t 175 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 176 const struct iovec *_iov, int iovcnt) 177 { 178 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 179 } 180