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Amit Shahe4d56392010-04-27 18:04:05 +05301/*
2 * Helpers for getting linearized buffers from iov / filling buffers into iovs
3 *
4 * Copyright IBM, Corp. 2007, 2008
5 * Copyright (C) 2010 Red Hat, Inc.
6 *
7 * Author(s):
8 * Anthony Liguori <aliguori@us.ibm.com>
9 * Amit Shah <amit.shah@redhat.com>
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2. See
12 * the COPYING file in the top-level directory.
13 */
14
15#include "iov.h"
16
Hannes Reinecke348e7b82011-07-11 15:02:23 +020017size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt,
18 const void *buf, size_t iov_off, size_t size)
Amit Shahe4d56392010-04-27 18:04:05 +053019{
Hannes Reinecke348e7b82011-07-11 15:02:23 +020020 size_t iovec_off, buf_off;
Amit Shahe4d56392010-04-27 18:04:05 +053021 unsigned int i;
22
Hannes Reinecke348e7b82011-07-11 15:02:23 +020023 iovec_off = 0;
Amit Shahfa6111f2010-04-27 18:04:06 +053024 buf_off = 0;
Hannes Reinecke348e7b82011-07-11 15:02:23 +020025 for (i = 0; i < iov_cnt && size; i++) {
26 if (iov_off < (iovec_off + iov[i].iov_len)) {
27 size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off, size);
Amit Shahfa6111f2010-04-27 18:04:06 +053028
Hannes Reinecke348e7b82011-07-11 15:02:23 +020029 memcpy(iov[i].iov_base + (iov_off - iovec_off), buf + buf_off, len);
Amit Shahfa6111f2010-04-27 18:04:06 +053030
31 buf_off += len;
Hannes Reinecke348e7b82011-07-11 15:02:23 +020032 iov_off += len;
Amit Shahfa6111f2010-04-27 18:04:06 +053033 size -= len;
34 }
Hannes Reinecke348e7b82011-07-11 15:02:23 +020035 iovec_off += iov[i].iov_len;
Amit Shahfa6111f2010-04-27 18:04:06 +053036 }
37 return buf_off;
38}
39
Hannes Reinecke348e7b82011-07-11 15:02:23 +020040size_t iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
41 void *buf, size_t iov_off, size_t size)
42{
43 uint8_t *ptr;
44 size_t iovec_off, buf_off;
45 unsigned int i;
46
47 ptr = buf;
48 iovec_off = 0;
49 buf_off = 0;
50 for (i = 0; i < iov_cnt && size; i++) {
51 if (iov_off < (iovec_off + iov[i].iov_len)) {
52 size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
53
54 memcpy(ptr + buf_off, iov[i].iov_base + (iov_off - iovec_off), len);
55
56 buf_off += len;
57 iov_off += len;
58 size -= len;
59 }
60 iovec_off += iov[i].iov_len;
61 }
62 return buf_off;
63}
64
Gerd Hoffmann8d150282011-07-13 15:16:08 +020065size_t iov_clear(const struct iovec *iov, const unsigned int iov_cnt,
66 size_t iov_off, size_t size)
67{
68 size_t iovec_off, buf_off;
69 unsigned int i;
70
71 iovec_off = 0;
72 buf_off = 0;
73 for (i = 0; i < iov_cnt && size; i++) {
74 if (iov_off < (iovec_off + iov[i].iov_len)) {
75 size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
76
77 memset(iov[i].iov_base + (iov_off - iovec_off), 0, len);
78
79 buf_off += len;
80 iov_off += len;
81 size -= len;
82 }
83 iovec_off += iov[i].iov_len;
84 }
85 return buf_off;
86}
87
Hannes Reinecke348e7b82011-07-11 15:02:23 +020088size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt)
Amit Shahfa6111f2010-04-27 18:04:06 +053089{
90 size_t len;
91 unsigned int i;
92
93 len = 0;
Hannes Reinecke348e7b82011-07-11 15:02:23 +020094 for (i = 0; i < iov_cnt; i++) {
Amit Shahfa6111f2010-04-27 18:04:06 +053095 len += iov[i].iov_len;
96 }
97 return len;
98}
Gerd Hoffmann3a1dca92011-07-12 13:35:10 +020099
100void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,
101 FILE *fp, const char *prefix, size_t limit)
102{
103 unsigned int i, v, b;
104 uint8_t *c;
105
106 c = iov[0].iov_base;
107 for (i = 0, v = 0, b = 0; b < limit; i++, b++) {
108 if (i == iov[v].iov_len) {
109 i = 0; v++;
110 if (v == iov_cnt) {
111 break;
112 }
113 c = iov[v].iov_base;
114 }
115 if ((b % 16) == 0) {
116 fprintf(fp, "%s: %04x:", prefix, b);
117 }
118 if ((b % 4) == 0) {
119 fprintf(fp, " ");
120 }
121 fprintf(fp, " %02x", c[i]);
122 if ((b % 16) == 15) {
123 fprintf(fp, "\n");
124 }
125 }
126 if ((b % 16) != 0) {
127 fprintf(fp, "\n");
128 }
129}