1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2016 Jakub Klama <jceel@FreeBSD.org>. 5 * Copyright (c) 2018 Alexander Motin <mav@FreeBSD.org> 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 * in this position and unchanged. 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 AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 #include <sys/param.h> 33 #include <sys/types.h> 34 #include <sys/uio.h> 35 36 #include <stdlib.h> 37 #include <string.h> 38 #include "iov.h" 39 40 void 41 seek_iov(const struct iovec *iov1, int niov1, struct iovec *iov2, int *niov2, 42 size_t seek) 43 { 44 size_t remainder = 0; 45 size_t left = seek; 46 int i, j; 47 48 for (i = 0; i < niov1; i++) { 49 size_t toseek = MIN(left, iov1[i].iov_len); 50 left -= toseek; 51 52 if (toseek == iov1[i].iov_len) 53 continue; 54 55 if (left == 0) { 56 remainder = toseek; 57 break; 58 } 59 } 60 61 for (j = i; j < niov1; j++) { 62 iov2[j - i].iov_base = (char *)iov1[j].iov_base + remainder; 63 iov2[j - i].iov_len = iov1[j].iov_len - remainder; 64 remainder = 0; 65 } 66 67 *niov2 = j - i; 68 } 69 70 size_t 71 count_iov(const struct iovec *iov, int niov) 72 { 73 size_t total = 0; 74 int i; 75 76 for (i = 0; i < niov; i++) 77 total += iov[i].iov_len; 78 79 return (total); 80 } 81 82 void 83 truncate_iov(struct iovec *iov, int *niov, size_t length) 84 { 85 size_t done = 0; 86 int i; 87 88 for (i = 0; i < *niov; i++) { 89 size_t toseek = MIN(length - done, iov[i].iov_len); 90 done += toseek; 91 92 if (toseek <= iov[i].iov_len) { 93 iov[i].iov_len = toseek; 94 *niov = i + 1; 95 return; 96 } 97 } 98 } 99 100 ssize_t 101 iov_to_buf(const struct iovec *iov, int niov, void **buf) 102 { 103 size_t ptr, total; 104 int i; 105 106 total = count_iov(iov, niov); 107 *buf = realloc(*buf, total); 108 if (*buf == NULL) 109 return (-1); 110 111 for (i = 0, ptr = 0; i < niov; i++) { 112 memcpy((uint8_t *)*buf + ptr, iov[i].iov_base, iov[i].iov_len); 113 ptr += iov[i].iov_len; 114 } 115 116 return (total); 117 } 118 119 ssize_t 120 buf_to_iov(const void *buf, size_t buflen, const struct iovec *iov, int niov, 121 size_t seek) 122 { 123 struct iovec *diov; 124 size_t off = 0, len; 125 int i; 126 127 if (seek > 0) { 128 int ndiov; 129 130 diov = malloc(sizeof(struct iovec) * niov); 131 seek_iov(iov, niov, diov, &ndiov, seek); 132 iov = diov; 133 niov = ndiov; 134 } 135 136 for (i = 0; i < niov && off < buflen; i++) { 137 len = MIN(iov[i].iov_len, buflen - off); 138 memcpy(iov[i].iov_base, (const uint8_t *)buf + off, len); 139 off += len; 140 } 141 142 if (seek > 0) 143 free(diov); 144 145 return ((ssize_t)off); 146 } 147 148