1 /* $NetBSD: atomicio.c,v 1.6 2015/04/03 23:58:19 christos Exp $ */ 2 /* $OpenBSD: atomicio.c,v 1.27 2015/01/16 06:40:12 deraadt Exp $ */ 3 /* 4 * Copyright (c) 2006 Damien Miller. All rights reserved. 5 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved. 6 * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include "includes.h" 31 __RCSID("$NetBSD: atomicio.c,v 1.6 2015/04/03 23:58:19 christos Exp $"); 32 #include <sys/param.h> 33 #include <sys/uio.h> 34 35 #include <errno.h> 36 #include <poll.h> 37 #include <string.h> 38 #include <unistd.h> 39 #include <limits.h> 40 41 #include "atomicio.h" 42 43 /* 44 * ensure all of data on socket comes through. f==read || f==vwrite 45 */ 46 size_t 47 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n, 48 int (*cb)(void *, size_t), void *cb_arg) 49 { 50 char *s = _s; 51 size_t pos = 0; 52 ssize_t res; 53 struct pollfd pfd; 54 55 pfd.fd = fd; 56 /* 57 * check for vwrite instead of read to avoid read being renamed 58 * by SSP issues 59 */ 60 pfd.events = f == vwrite ? POLLOUT : POLLIN; 61 while (n > pos) { 62 res = (f) (fd, s + pos, n - pos); 63 switch (res) { 64 case -1: 65 if (errno == EINTR) 66 continue; 67 if (errno == EAGAIN) { 68 (void)poll(&pfd, 1, -1); 69 continue; 70 } 71 return 0; 72 case 0: 73 errno = EPIPE; 74 return pos; 75 default: 76 pos += (size_t)res; 77 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 78 errno = EINTR; 79 return pos; 80 } 81 } 82 } 83 return pos; 84 } 85 86 size_t 87 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 88 { 89 return atomicio6(f, fd, _s, n, NULL, NULL); 90 } 91 92 /* 93 * ensure all of data on socket comes through. f==readv || f==writev 94 */ 95 size_t 96 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 97 const struct iovec *_iov, int iovcnt, 98 int (*cb)(void *, size_t), void *cb_arg) 99 { 100 size_t pos = 0, rem; 101 ssize_t res; 102 struct iovec iov_array[IOV_MAX], *iov = iov_array; 103 struct pollfd pfd; 104 105 if (iovcnt > IOV_MAX) { 106 errno = EINVAL; 107 return 0; 108 } 109 /* Make a copy of the iov array because we may modify it below */ 110 memcpy(iov, _iov, iovcnt * sizeof(*_iov)); 111 112 pfd.fd = fd; 113 pfd.events = f == readv ? POLLIN : POLLOUT; 114 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 115 res = (f) (fd, iov, iovcnt); 116 switch (res) { 117 case -1: 118 if (errno == EINTR) 119 continue; 120 if (errno == EAGAIN) { 121 (void)poll(&pfd, 1, -1); 122 continue; 123 } 124 return 0; 125 case 0: 126 errno = EPIPE; 127 return pos; 128 default: 129 rem = (size_t)res; 130 pos += rem; 131 /* skip completed iov entries */ 132 while (iovcnt > 0 && rem >= iov[0].iov_len) { 133 rem -= iov[0].iov_len; 134 iov++; 135 iovcnt--; 136 } 137 /* This shouldn't happen... */ 138 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 139 errno = EFAULT; 140 return 0; 141 } 142 if (iovcnt == 0) 143 break; 144 /* update pointer in partially complete iov */ 145 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 146 iov[0].iov_len -= rem; 147 } 148 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 149 errno = EINTR; 150 return pos; 151 } 152 } 153 return pos; 154 } 155 156 size_t 157 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 158 const struct iovec *_iov, int iovcnt) 159 { 160 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 161 } 162