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/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 pfd.fd = fd; 61 #ifndef BROKEN_READ_COMPARISON 62 pfd.events = f == read ? POLLIN : POLLOUT; 63 #else 64 pfd.events = POLLIN|POLLOUT; 65 #endif 66 while (n > pos) { 67 res = (f) (fd, s + pos, n - pos); 68 switch (res) { 69 case -1: 70 if (errno == EINTR) { 71 /* possible SIGALARM, update callback */ 72 if (cb != NULL && cb(cb_arg, 0) == -1) { 73 errno = EINTR; 74 return pos; 75 } 76 continue; 77 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 78 (void)poll(&pfd, 1, -1); 79 continue; 80 } 81 return 0; 82 case 0: 83 errno = EPIPE; 84 return pos; 85 default: 86 pos += (size_t)res; 87 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 88 errno = EINTR; 89 return pos; 90 } 91 } 92 } 93 return pos; 94 } 95 96 size_t 97 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 98 { 99 return atomicio6(f, fd, _s, n, NULL, NULL); 100 } 101 102 /* 103 * ensure all of data on socket comes through. f==readv || f==writev 104 */ 105 size_t 106 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 107 const struct iovec *_iov, int iovcnt, 108 int (*cb)(void *, size_t), void *cb_arg) 109 { 110 size_t pos = 0, rem; 111 ssize_t res; 112 struct iovec iov_array[IOV_MAX], *iov = iov_array; 113 struct pollfd pfd; 114 115 if (iovcnt < 0 || iovcnt > IOV_MAX) { 116 errno = EINVAL; 117 return 0; 118 } 119 /* Make a copy of the iov array because we may modify it below */ 120 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); 121 122 pfd.fd = fd; 123 #ifndef BROKEN_READV_COMPARISON 124 pfd.events = f == readv ? POLLIN : POLLOUT; 125 #else 126 pfd.events = POLLIN|POLLOUT; 127 #endif 128 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 129 res = (f) (fd, iov, iovcnt); 130 switch (res) { 131 case -1: 132 if (errno == EINTR) { 133 /* possible SIGALARM, update callback */ 134 if (cb != NULL && cb(cb_arg, 0) == -1) { 135 errno = EINTR; 136 return pos; 137 } 138 continue; 139 } else if (errno == EAGAIN || errno == EWOULDBLOCK) { 140 (void)poll(&pfd, 1, -1); 141 continue; 142 } 143 return 0; 144 case 0: 145 errno = EPIPE; 146 return pos; 147 default: 148 rem = (size_t)res; 149 pos += rem; 150 /* skip completed iov entries */ 151 while (iovcnt > 0 && rem >= iov[0].iov_len) { 152 rem -= iov[0].iov_len; 153 iov++; 154 iovcnt--; 155 } 156 /* This shouldn't happen... */ 157 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 158 errno = EFAULT; 159 return 0; 160 } 161 if (iovcnt == 0) 162 break; 163 /* update pointer in partially complete iov */ 164 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 165 iov[0].iov_len -= rem; 166 } 167 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 168 errno = EINTR; 169 return pos; 170 } 171 } 172 return pos; 173 } 174 175 size_t 176 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 177 const struct iovec *_iov, int iovcnt) 178 { 179 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 180 } 181