1/*      $OpenBSD: criov.c,v 1.20 2015/03/14 03:38:46 jsg Exp $	*/
2
3/*
4 * Copyright (c) 1999 Theo de Raadt
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *   notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *   notice, this list of conditions and the following disclaimer in the
14 *   documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/param.h>
29#include <sys/systm.h>
30#include <sys/errno.h>
31#include <sys/kernel.h>
32#include <sys/mbuf.h>
33
34void
35cuio_copydata(struct uio *uio, int off, int len, caddr_t cp)
36{
37	struct iovec *iov = uio->uio_iov;
38	int iol = uio->uio_iovcnt;
39	unsigned count;
40
41	if (off < 0)
42		panic("cuio_copydata: off %d < 0", off);
43	if (len < 0)
44		panic("cuio_copydata: len %d < 0", len);
45	while (off > 0) {
46		if (iol == 0)
47			panic("iov_copydata: empty in skip");
48		if (off < iov->iov_len)
49			break;
50		off -= iov->iov_len;
51		iol--;
52		iov++;
53	}
54	while (len > 0) {
55		if (iol == 0)
56			panic("cuio_copydata: empty");
57		count = min(iov->iov_len - off, len);
58		bcopy(((caddr_t)iov->iov_base) + off, cp, count);
59		len -= count;
60		cp += count;
61		off = 0;
62		iol--;
63		iov++;
64	}
65}
66
67void
68cuio_copyback(struct uio *uio, int off, int len, const void *_cp)
69{
70	struct iovec *iov = uio->uio_iov;
71	int iol = uio->uio_iovcnt;
72	unsigned count;
73	caddr_t cp = (caddr_t)_cp;
74
75	if (off < 0)
76		panic("cuio_copyback: off %d < 0", off);
77	if (len < 0)
78		panic("cuio_copyback: len %d < 0", len);
79	while (off > 0) {
80		if (iol == 0)
81			panic("cuio_copyback: empty in skip");
82		if (off < iov->iov_len)
83			break;
84		off -= iov->iov_len;
85		iol--;
86		iov++;
87	}
88	while (len > 0) {
89		if (iol == 0)
90			panic("uio_copyback: empty");
91		count = min(iov->iov_len - off, len);
92		bcopy(cp, ((caddr_t)iov->iov_base) + off, count);
93		len -= count;
94		cp += count;
95		off = 0;
96		iol--;
97		iov++;
98	}
99}
100
101int
102cuio_getptr(struct uio *uio, int loc, int *off)
103{
104	int ind, len;
105
106	ind = 0;
107	while (loc >= 0 && ind < uio->uio_iovcnt) {
108		len = uio->uio_iov[ind].iov_len;
109		if (len > loc) {
110			*off = loc;
111			return (ind);
112		}
113		loc -= len;
114		ind++;
115	}
116
117	if (ind > 0 && loc == 0) {
118		ind--;
119		*off = uio->uio_iov[ind].iov_len;
120		return (ind);
121	}
122
123	return (-1);
124}
125
126int
127cuio_apply(struct uio *uio, int off, int len,
128    int (*f)(caddr_t, caddr_t, unsigned int), caddr_t fstate)
129{
130	int rval, ind, uiolen;
131	unsigned int count;
132
133	if (len < 0)
134		panic("cuio_apply: len %d < 0", len);
135	if (off < 0)
136		panic("cuio_apply: off %d < 0", off);
137
138	ind = 0;
139	while (off > 0) {
140		if (ind >= uio->uio_iovcnt)
141			panic("cuio_apply: ind %d >= uio_iovcnt %d for off",
142			    ind, uio->uio_iovcnt);
143		uiolen = uio->uio_iov[ind].iov_len;
144		if (off < uiolen)
145			break;
146		off -= uiolen;
147		ind++;
148	}
149	while (len > 0) {
150		if (ind >= uio->uio_iovcnt)
151			panic("cuio_apply: ind %d >= uio_iovcnt %d for len",
152			    ind, uio->uio_iovcnt);
153		count = min(uio->uio_iov[ind].iov_len - off, len);
154
155		rval = f(fstate, (char *)uio->uio_iov[ind].iov_base + off,
156		    count);
157		if (rval)
158			return (rval);
159
160		len -= count;
161		off = 0;
162		ind++;
163	}
164
165	return (0);
166}
167