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