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 pfd.fd = fd; 60 pfd.events = f == read ? POLLIN : POLLOUT; 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 || errno == EWOULDBLOCK) { 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 #ifndef BROKEN_READV_COMPARISON 113 pfd.fd = fd; 114 pfd.events = f == readv ? POLLIN : POLLOUT; 115 #endif 116 for (; iovcnt > 0 && iov[0].iov_len > 0;) { 117 res = (f) (fd, iov, iovcnt); 118 switch (res) { 119 case -1: 120 if (errno == EINTR) 121 continue; 122 if (errno == EAGAIN || errno == EWOULDBLOCK) { 123 #ifndef BROKEN_READV_COMPARISON 124 (void)poll(&pfd, 1, -1); 125 #endif 126 continue; 127 } 128 return 0; 129 case 0: 130 errno = EPIPE; 131 return pos; 132 default: 133 rem = (size_t)res; 134 pos += rem; 135 /* skip completed iov entries */ 136 while (iovcnt > 0 && rem >= iov[0].iov_len) { 137 rem -= iov[0].iov_len; 138 iov++; 139 iovcnt--; 140 } 141 /* This shouldn't happen... */ 142 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { 143 errno = EFAULT; 144 return 0; 145 } 146 if (iovcnt == 0) 147 break; 148 /* update pointer in partially complete iov */ 149 iov[0].iov_base = ((char *)iov[0].iov_base) + rem; 150 iov[0].iov_len -= rem; 151 } 152 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) { 153 errno = EINTR; 154 return pos; 155 } 156 } 157 return pos; 158 } 159 160 size_t 161 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, 162 const struct iovec *_iov, int iovcnt) 163 { 164 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL); 165 } 166
