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 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(const struct iovec *iov1, int niov1, struct iovec *iov2, int *niov2, 43 size_t seek) 44 { 45 size_t remainder = 0; 46 size_t left = seek; 47 int 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(const struct iovec *iov, int niov) 73 { 74 size_t total = 0; 75 int i; 76 77 for (i = 0; i < niov; i++) 78 total += iov[i].iov_len; 79 80 return (total); 81 } 82 83 void 84 truncate_iov(struct iovec *iov, int *niov, size_t length) 85 { 86 size_t done = 0; 87 int i; 88 89 for (i = 0; i < *niov; i++) { 90 size_t toseek = MIN(length - done, iov[i].iov_len); 91 done += toseek; 92 93 if (toseek <= iov[i].iov_len) { 94 iov[i].iov_len = toseek; 95 *niov = i + 1; 96 return; 97 } 98 } 99 } 100 101 ssize_t 102 iov_to_buf(const struct iovec *iov, int niov, void **buf) 103 { 104 size_t ptr, total; 105 int i; 106 107 total = count_iov(iov, niov); 108 *buf = realloc(*buf, total); 109 if (*buf == NULL) 110 return (-1); 111 112 for (i = 0, ptr = 0; i < niov; i++) { 113 memcpy((uint8_t *)*buf + ptr, iov[i].iov_base, iov[i].iov_len); 114 ptr += iov[i].iov_len; 115 } 116 117 return (total); 118 } 119 120 ssize_t 121 buf_to_iov(const void *buf, size_t buflen, const struct iovec *iov, int niov, 122 size_t seek) 123 { 124 struct iovec *diov; 125 size_t off = 0, len; 126 int i; 127 128 #ifndef __FreeBSD__ 129 diov = NULL; 130 #endif 131 132 if (seek > 0) { 133 int ndiov; 134 135 diov = malloc(sizeof(struct iovec) * niov); 136 seek_iov(iov, niov, diov, &ndiov, seek); 137 iov = diov; 138 niov = ndiov; 139 } 140 141 for (i = 0; i < niov && off < buflen; i++) { 142 len = MIN(iov[i].iov_len, buflen - off); 143 memcpy(iov[i].iov_base, (const uint8_t *)buf + off, len); 144 off += len; 145 } 146 147 if (seek > 0) 148 free(diov); 149 150 return ((ssize_t)off); 151 } 152 153