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
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
seek_iov(const struct iovec * iov1,int niov1,struct iovec * iov2,int * niov2,size_t seek)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
count_iov(const struct iovec * iov,int niov)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
truncate_iov(struct iovec * iov,int * niov,size_t length)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
iov_to_buf(const struct iovec * iov,int niov,void ** buf)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
buf_to_iov(const void * buf,size_t buflen,const struct iovec * iov,int niov,size_t seek)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 #ifndef __FreeBSD__
128 diov = NULL;
129 #endif
130
131 if (seek > 0) {
132 int ndiov;
133
134 diov = malloc(sizeof(struct iovec) * niov);
135 seek_iov(iov, niov, diov, &ndiov, seek);
136 iov = diov;
137 niov = ndiov;
138 }
139
140 for (i = 0; i < niov && off < buflen; i++) {
141 len = MIN(iov[i].iov_len, buflen - off);
142 memcpy(iov[i].iov_base, (const uint8_t *)buf + off, len);
143 off += len;
144 }
145
146 if (seek > 0)
147 free(diov);
148
149 return ((ssize_t)off);
150 }
151
152