1 /* $OpenBSD: atomicio.c,v 1.28 2016/07/27 23:18:12 djm 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 <sys/uio.h> 30 31 #include <errno.h> 32 #include <poll.h> 33 #include <string.h> 34 #include <unistd.h> 35 #include <limits.h> 36 37 #include "atomicio.h" 38 39 /* 40 * ensure all of data on socket comes through. f==read || f==vwrite 41 */ 42 size_t 43 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 44 int (*cb)(void *, size_t), void *cb_arg) 45 { 46 char *s = _s; 47 size_t pos = 0; 48 ssize_t res; 49 struct pollfd pfd; 50 51 pfd.fd = fd; 52 pfd.events = f == read ? POLLIN : POLLOUT; 53 while (n > pos) { 54 res = (f) (fd, s + pos, n - pos); 55 switch (res) { 56 case -1: 57 if (errno == EINTR) 58 continue; 59 if (errno == EAGAIN) { 60 (void)poll(&pfd, 1, -1); 61 continue; 62 } 63 return 0; 64 case 0: 65 errno = EPIPE; 66 return pos; 67 default: 68 pos += (size_t)res; 69 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 70 errno = EINTR; 71 return pos; 72 } 73 } 74 } 75 return pos; 76 } 77 78 size_t 79 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 80 { 81 return atomicio6(f, fd, _s, n, NULL, NULL); 82 } 83 84 /* 85 * ensure all of data on socket comes through. f==readv || f==writev 86 */ 87 size_t 88 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 89 const struct iovec *_iov, int iovcnt, 90 int (*cb)(void *, size_t), void *cb_arg) 91 { 92 size_t pos = 0, rem; 93 ssize_t res; 94 struct iovec iov_array[IOV_MAX], *iov = iov_array; 95 struct pollfd pfd; 96 97 if (iovcnt < 0 || iovcnt > IOV_MAX) { 98 errno = EINVAL; 99 return 0; 100 } 101 /* Make a copy of the iov array because we may modify it below */ 102 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov)); 103 104 pfd.fd = fd; 105 pfd.events = f == readv ? POLLIN : POLLOUT; 106 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 107 res = (f) (fd, iov, iovcnt); 108 switch (res) { 109 case -1: 110 if (errno == EINTR) 111 continue; 112 if (errno == EAGAIN) { 113 (void)poll(&pfd, 1, -1); 114 continue; 115 } 116 return 0; 117 case 0: 118 errno = EPIPE; 119 return pos; 120 default: 121 rem = (size_t)res; 122 pos += rem; 123 /* skip completed iov entries */ 124 while (iovcnt > 0 && rem >= iov[0].iov_len) { 125 rem -= iov[0].iov_len; 126 iov++; 127 iovcnt--; 128 } 129 /* This shouldn't happen... */ 130 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 131 errno = EFAULT; 132 return 0; 133 } 134 if (iovcnt == 0) 135 break; 136 /* update pointer in partially complete iov */ 137 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 138 iov[0].iov_len -= rem; 139 } 140 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 141 errno = EINTR; 142 return pos; 143 } 144 } 145 return pos; 146 } 147 148 size_t 149 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 150 const struct iovec *_iov, int iovcnt) 151 { 152 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 153 } 154