1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2016 Jakub Klama <jceel@FreeBSD.org>. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 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 AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/types.h> 35 #include <sys/uio.h> 36 37 #include <stdlib.h> 38 #include <string.h> 39 #include "iov.h" 40 41 void 42 seek_iov(struct iovec *iov1, size_t niov1, struct iovec *iov2, size_t *niov2, 43 size_t seek) 44 { 45 size_t remainder = 0; 46 size_t left = seek; 47 size_t i, j; 48 49 for (i = 0; i < niov1; i++) { 50 size_t toseek = MIN(left, iov1[i].iov_len); 51 left -= toseek; 52 53 if (toseek == iov1[i].iov_len) 54 continue; 55 56 if (left == 0) { 57 remainder = toseek; 58 break; 59 } 60 } 61 62 for (j = i; j < niov1; j++) { 63 iov2[j - i].iov_base = (char *)iov1[j].iov_base + remainder; 64 iov2[j - i].iov_len = iov1[j].iov_len - remainder; 65 remainder = 0; 66 } 67 68 *niov2 = j - i; 69 } 70 71 size_t 72 count_iov(struct iovec *iov, size_t niov) 73 { 74 size_t i, total = 0; 75 76 for (i = 0; i < niov; i++) 77 total += iov[i].iov_len; 78 79 return (total); 80 } 81 82 size_t 83 truncate_iov(struct iovec *iov, size_t niov, size_t length) 84 { 85 size_t i, done = 0; 86 87 for (i = 0; i < niov; i++) { 88 size_t toseek = MIN(length - done, iov[i].iov_len); 89 done += toseek; 90 91 if (toseek < iov[i].iov_len) { 92 iov[i].iov_len = toseek; 93 return (i + 1); 94 } 95 } 96 97 return (niov); 98 } 99 100 ssize_t 101 iov_to_buf(struct iovec *iov, size_t niov, void **buf) 102 { 103 size_t i, ptr = 0, total = 0; 104 105 for (i = 0; i < niov; i++) { 106 total += iov[i].iov_len; 107 *buf = realloc(*buf, total); 108 if (*buf == NULL) 109 return (-1); 110 111 memcpy(*buf + ptr, iov[i].iov_base, iov[i].iov_len); 112 ptr += iov[i].iov_len; 113 } 114 115 return (total); 116 } 117 118 ssize_t 119 buf_to_iov(void *buf, size_t buflen, struct iovec *iov, size_t niov, 120 size_t seek) 121 { 122 struct iovec *diov; 123 size_t ndiov, i; 124 uintptr_t off = 0; 125 126 if (seek > 0) { 127 diov = malloc(sizeof(struct iovec) * niov); 128 seek_iov(iov, niov, diov, &ndiov, seek); 129 } else { 130 diov = iov; 131 ndiov = niov; 132 } 133 134 for (i = 0; i < ndiov; i++) { 135 memcpy(diov[i].iov_base, buf + off, diov[i].iov_len); 136 off += diov[i].iov_len; 137 } 138 139 return ((ssize_t)off); 140 } 141 142