1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 * Copyright (c) 2015, Joyent, Inc. All rights reserved.
26 * Copyright 2017 Nexenta Systems, Inc. All rights reserved.
27 */
28
29 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
30 /* All Rights Reserved */
31
32 /*
33 * Portions of this source code were derived from Berkeley 4.3 BSD
34 * under license from the Regents of the University of California.
35 */
36
37 #include <sys/param.h>
38 #include <sys/types.h>
39 #include <sys/inttypes.h>
40 #include <sys/sysmacros.h>
41 #include <sys/cred.h>
42 #include <sys/user.h>
43 #include <sys/systm.h>
44 #include <sys/errno.h>
45 #include <sys/vnode.h>
46 #include <sys/file.h>
47 #include <sys/proc.h>
48 #include <sys/uio.h>
49 #include <sys/debug.h>
50
51 #include <libfksmbfs.h>
52
53 #define set_errno(e) (-(e))
54
55 ssize_t
56 fake_pread(vnode_t *vp, void *cbuf, size_t count, off_t offset)
57 {
58 struct uio auio;
59 struct iovec aiov;
60 int fflag, ioflag, rwflag;
61 ssize_t bcount;
62 int error = 0;
63 u_offset_t fileoff = (u_offset_t)(ulong_t)offset;
64 const u_offset_t maxoff = MAXOFF32_T;
65
66 if ((bcount = (ssize_t)count) < 0)
67 return (set_errno(EINVAL));
68 fflag = FREAD;
69
70 rwflag = 0;
71
72 if (vp->v_type == VREG) {
73
74 if (bcount == 0)
75 goto out;
76
77 /*
78 * Return EINVAL if an invalid offset comes to pread.
79 * Negative offset from user will cause this error.
80 */
81
82 if (fileoff > maxoff) {
83 error = EINVAL;
84 goto out;
85 }
86 /*
87 * Limit offset such that we don't read or write
88 * a file beyond the maximum offset representable in
89 * an off_t structure.
90 */
91 if (fileoff + bcount > maxoff)
92 bcount = (ssize_t)((offset_t)maxoff - fileoff);
93 } else if (vp->v_type == VFIFO) {
94 error = ESPIPE;
95 goto out;
96 }
97
98 aiov.iov_base = cbuf;
99 aiov.iov_len = bcount;
100 (void) VOP_RWLOCK(vp, rwflag, NULL);
101 auio.uio_loffset = fileoff;
102 auio.uio_iov = &aiov;
103 auio.uio_iovcnt = 1;
104 auio.uio_resid = bcount;
105 auio.uio_segflg = UIO_USERSPACE;
106 auio.uio_llimit = MAXOFFSET_T;
107 auio.uio_fmode = fflag;
108 auio.uio_extflg = UIO_COPY_CACHED;
109
110 ioflag = auio.uio_fmode & (FAPPEND|FSYNC|FDSYNC|FRSYNC);
111
112 /* If read sync is not asked for, filter sync flags */
113 if ((ioflag & FRSYNC) == 0)
114 ioflag &= ~(FSYNC|FDSYNC);
115 error = VOP_READ(vp, &auio, ioflag, CRED(), NULL);
116 bcount -= auio.uio_resid;
117 VOP_RWUNLOCK(vp, rwflag, NULL);
118
119 if (error == EINTR && bcount != 0)
120 error = 0;
121 out:
122 if (error)
123 return (set_errno(error));
124 return (bcount);
125 }
126
127 ssize_t
128 fake_pwrite(vnode_t *vp, void *cbuf, size_t count, off_t offset)
129 {
130 struct uio auio;
131 struct iovec aiov;
132 int fflag, ioflag, rwflag;
133 ssize_t bcount;
134 int error = 0;
135 u_offset_t fileoff = (u_offset_t)(ulong_t)offset;
136 const u_offset_t maxoff = MAXOFF32_T;
137
138 if ((bcount = (ssize_t)count) < 0)
139 return (set_errno(EINVAL));
140 fflag = FREAD | FWRITE;
141
142 rwflag = 1;
143
144 if (vp->v_type == VREG) {
145
146 if (bcount == 0)
147 goto out;
148
149 /*
150 * return EINVAL for offsets that cannot be
151 * represented in an off_t.
152 */
153 if (fileoff > maxoff) {
154 error = EINVAL;
155 goto out;
156 }
157 /*
158 * Don't allow pwrite to cause file sizes to exceed
159 * maxoff.
160 */
161 if (fileoff == maxoff) {
162 error = EFBIG;
163 goto out;
164 }
165 if (fileoff + count > maxoff)
166 bcount = (ssize_t)((u_offset_t)maxoff - fileoff);
167 } else if (vp->v_type == VFIFO) {
168 error = ESPIPE;
169 goto out;
170 }
171
172 aiov.iov_base = cbuf;
173 aiov.iov_len = bcount;
174 (void) VOP_RWLOCK(vp, rwflag, NULL);
175 auio.uio_loffset = fileoff;
176 auio.uio_iov = &aiov;
177 auio.uio_iovcnt = 1;
178 auio.uio_resid = bcount;
179 auio.uio_segflg = UIO_USERSPACE;
180 auio.uio_llimit = MAXOFFSET_T;
181 auio.uio_fmode = fflag;
182 auio.uio_extflg = UIO_COPY_CACHED;
183
184 /*
185 * The SUSv4 POSIX specification states:
186 * The pwrite() function shall be equivalent to write(), except
187 * that it writes into a given position and does not change
188 * the file offset (regardless of whether O_APPEND is set).
189 * To make this be true, we omit the FAPPEND flag from ioflag.
190 */
191 ioflag = auio.uio_fmode & (FSYNC|FDSYNC|FRSYNC);
192
193 error = VOP_WRITE(vp, &auio, ioflag, CRED(), NULL);
194 bcount -= auio.uio_resid;
195 VOP_RWUNLOCK(vp, rwflag, NULL);
196
197 if (error == EINTR && bcount != 0)
198 error = 0;
199 out:
200 if (error)
201 return (set_errno(error));
202 return (bcount);
203 }