1 /* $OpenBSD: atomicio.c,v 1.26 2010/09/22 22:58:51 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 "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 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 #ifndef BROKEN_READ_COMPARISON 60 pfd.fd = fd; 61 pfd.events = f == read ? POLLIN : POLLOUT; 62 #endif 63 while (n > pos) { 64 res = (f) (fd, s + pos, n - pos); 65 switch (res) { 66 case -1: 67 if (errno == EINTR) 68 continue; 69 if (errno == EAGAIN || errno == EWOULDBLOCK) { 70 #ifndef BROKEN_READ_COMPARISON 71 (void)poll(&pfd, 1, -1); 72 #endif 73 continue; 74 } 75 return 0; 76 case 0: 77 errno = EPIPE; 78 return pos; 79 default: 80 pos += (size_t)res; 81 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 82 errno = EINTR; 83 return pos; 84 } 85 } 86 } 87 return pos; 88 } 89 90 size_t 91 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) 92 { 93 return atomicio6(f, fd, _s, n, NULL, NULL); 94 } 95 96 /* 97 * ensure all of data on socket comes through. f==readv || f==writev 98 */ 99 size_t 100 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd, 101 const struct iovec *_iov, int iovcnt, 102 int (*cb)(void *, size_t), void *cb_arg) 103 { 104 size_t pos = 0, rem; 105 ssize_t res; 106 struct iovec iov_array[IOV_MAX], *iov = iov_array; 107 struct pollfd pfd; 108 109 if (iovcnt > IOV_MAX) { 110 errno = EINVAL; 111 return 0; 112 } 113 /* Make a copy of the iov array because we may modify it below */ 114 memcpy(iov, _iov, iovcnt * sizeof(*_iov)); 115 116 #ifndef BROKEN_READV_COMPARISON 117 pfd.fd = fd; 118 pfd.events = f == readv ? POLLIN : POLLOUT; 119 #endif 120 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 121 res = (f) (fd, iov, iovcnt); 122 switch (res) { 123 case -1: 124 if (errno == EINTR) 125 continue; 126 if (errno == EAGAIN || errno == EWOULDBLOCK) { 127 #ifndef BROKEN_READV_COMPARISON 128 (void)poll(&pfd, 1, -1); 129 #endif 130 continue; 131 } 132 return 0; 133 case 0: 134 errno = EPIPE; 135 return pos; 136 default: 137 rem = (size_t)res; 138 pos += rem; 139 /* skip completed iov entries */ 140 while (iovcnt > 0 && rem >= iov[0].iov_len) { 141 rem -= iov[0].iov_len; 142 iov++; 143 iovcnt--; 144 } 145 /* This shouldn't happen... */ 146 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 147 errno = EFAULT; 148 return 0; 149 } 150 if (iovcnt == 0) 151 break; 152 /* update pointer in partially complete iov */ 153 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 154 iov[0].iov_len -= rem; 155 } 156 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 157 errno = EINTR; 158 return pos; 159 } 160 } 161 return pos; 162 } 163 164 size_t 165 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 166 const struct iovec *_iov, int iovcnt) 167 { 168 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 169 } 170