1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2017 Nexenta Systems, Inc. All rights reserved.
14 */
15
16 #include <sys/types.h>
17 #include <sys/sysmacros.h>
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/uio.h>
21 #include <sys/errno.h>
22
23 /*
24 * Move "n" bytes at byte address "p"; "rw" indicates the direction
25 * of the move, and the I/O parameters are provided in "uio", which is
26 * update to reflect the data which was moved. Returns 0 on success or
27 * a non-zero errno on failure.
28 */
29 int
uiomove(void * p,size_t n,enum uio_rw rw,struct uio * uio)30 uiomove(void *p, size_t n, enum uio_rw rw, struct uio *uio)
31 {
32 struct iovec *iov;
33 ulong_t cnt;
34
35 while (n && uio->uio_resid) {
36 iov = uio->uio_iov;
37 cnt = MIN(iov->iov_len, n);
38 if (cnt == 0L) {
39 uio->uio_iov++;
40 uio->uio_iovcnt--;
41 continue;
42 }
43 switch (uio->uio_segflg) {
44
45 case UIO_USERISPACE:
46 return (EINVAL);
47
48 case UIO_USERSPACE:
49 case UIO_SYSSPACE:
50 if (rw == UIO_READ)
51 bcopy(p, iov->iov_base, cnt);
52 else
53 bcopy(iov->iov_base, p, cnt);
54 break;
55 }
56 iov->iov_base += cnt;
57 iov->iov_len -= cnt;
58 uio->uio_resid -= cnt;
59 uio->uio_loffset += cnt;
60 p = (caddr_t)p + cnt;
61 n -= cnt;
62 }
63 return (0);
64 }
65
66 /*
67 * Drop the next n chars out of *uiop.
68 */
69 void
uioskip(uio_t * uiop,size_t n)70 uioskip(uio_t *uiop, size_t n)
71 {
72 if (n > uiop->uio_resid)
73 return;
74 while (n != 0) {
75 iovec_t *iovp = uiop->uio_iov;
76 size_t niovb = MIN(iovp->iov_len, n);
77
78 if (niovb == 0) {
79 uiop->uio_iov++;
80 uiop->uio_iovcnt--;
81 continue;
82 }
83 iovp->iov_base += niovb;
84 uiop->uio_loffset += niovb;
85 iovp->iov_len -= niovb;
86 uiop->uio_resid -= niovb;
87 n -= niovb;
88 }
89 }
90