1 | /* $NetBSD: linux32_dirent.c,v 1.13 2011/10/14 09:23:29 hannken Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2006 Emmanuel Dreyfus, all rights reserved. |
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 | * 1. Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * 2. Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
14 | * 3. All advertising materials mentioning features or use of this software |
15 | * must display the following acknowledgement: |
16 | * This product includes software developed by Emmanuel Dreyfus |
17 | * 4. The name of the author may not be used to endorse or promote |
18 | * products derived from this software without specific prior written |
19 | * permission. |
20 | * |
21 | * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' |
22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
23 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
24 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS |
25 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
31 | * POSSIBILITY OF SUCH DAMAGE. |
32 | */ |
33 | |
34 | #include <sys/cdefs.h> |
35 | |
36 | __KERNEL_RCSID(0, "$NetBSD: linux32_dirent.c,v 1.13 2011/10/14 09:23:29 hannken Exp $" ); |
37 | |
38 | #include <sys/types.h> |
39 | #include <sys/param.h> |
40 | #include <sys/fstypes.h> |
41 | #include <sys/signal.h> |
42 | #include <sys/dirent.h> |
43 | #include <sys/kernel.h> |
44 | #include <sys/fcntl.h> |
45 | #include <sys/file.h> |
46 | #include <sys/filedesc.h> |
47 | #include <sys/malloc.h> |
48 | #include <sys/select.h> |
49 | #include <sys/proc.h> |
50 | #include <sys/ucred.h> |
51 | #include <sys/vnode.h> |
52 | #include <sys/swap.h> |
53 | |
54 | #include <machine/types.h> |
55 | |
56 | #include <sys/syscallargs.h> |
57 | |
58 | #include <compat/netbsd32/netbsd32.h> |
59 | #include <compat/netbsd32/netbsd32_conv.h> |
60 | #include <compat/netbsd32/netbsd32_syscallargs.h> |
61 | |
62 | #include <compat/linux/common/linux_types.h> |
63 | #include <compat/linux/common/linux_signal.h> |
64 | #include <compat/linux/common/linux_machdep.h> |
65 | #include <compat/linux/common/linux_misc.h> |
66 | #include <compat/linux/common/linux_oldolduname.h> |
67 | #include <compat/linux/common/linux_dirent.h> |
68 | #include <compat/linux/common/linux_ipc.h> |
69 | #include <compat/linux/common/linux_sem.h> |
70 | #include <compat/linux/linux_syscallargs.h> |
71 | |
72 | #include <compat/linux32/common/linux32_types.h> |
73 | #include <compat/linux32/common/linux32_signal.h> |
74 | #include <compat/linux32/common/linux32_machdep.h> |
75 | #include <compat/linux32/common/linux32_sysctl.h> |
76 | #include <compat/linux32/common/linux32_socketcall.h> |
77 | #include <compat/linux32/linux32_syscallargs.h> |
78 | |
79 | /* |
80 | * Linux 'readdir' call. This code is mostly taken from the |
81 | * SunOS getdents call (see compat/sunos/sunos_misc.c), though |
82 | * an attempt has been made to keep it a little cleaner (failing |
83 | * miserably, because of the cruft needed if count 1 is passed). |
84 | * |
85 | * The d_off field should contain the offset of the next valid entry, |
86 | * but in Linux it has the offset of the entry itself. We emulate |
87 | * that bug here. |
88 | * |
89 | * Read in BSD-style entries, convert them, and copy them out. |
90 | * |
91 | * Note that this doesn't handle union-mounted filesystems. |
92 | */ |
93 | |
94 | int |
95 | linux32_sys_getdents(struct lwp *l, const struct linux32_sys_getdents_args *uap, register_t *retval) |
96 | { |
97 | /* { |
98 | syscallarg(int) fd; |
99 | syscallarg(linux32_direntp_t) dent; |
100 | syscallarg(unsigned int) count; |
101 | } */ |
102 | struct dirent *bdp; |
103 | struct vnode *vp; |
104 | char *inp, *tbuf; /* BSD-format */ |
105 | int len, reclen; /* BSD-format */ |
106 | char *outp; /* Linux-format */ |
107 | int resid, linux32_reclen = 0; /* Linux-format */ |
108 | struct file *fp; |
109 | struct uio auio; |
110 | struct iovec aiov; |
111 | struct linux32_dirent idb; |
112 | off_t off; /* true file offset */ |
113 | int buflen, error, eofflag, nbytes, oldcall; |
114 | struct vattr va; |
115 | off_t *cookiebuf = NULL, *cookie; |
116 | int ncookies; |
117 | |
118 | /* fd_getvnode() will use the descriptor for us */ |
119 | if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0) |
120 | return (error); |
121 | |
122 | if ((fp->f_flag & FREAD) == 0) { |
123 | error = EBADF; |
124 | goto out1; |
125 | } |
126 | |
127 | vp = (struct vnode *)fp->f_data; |
128 | if (vp->v_type != VDIR) { |
129 | error = ENOTDIR; |
130 | goto out1; |
131 | } |
132 | |
133 | vn_lock(vp, LK_SHARED | LK_RETRY); |
134 | error = VOP_GETATTR(vp, &va, l->l_cred); |
135 | VOP_UNLOCK(vp); |
136 | if (error) |
137 | goto out1; |
138 | |
139 | nbytes = SCARG(uap, count); |
140 | if (nbytes == 1) { /* emulating old, broken behaviour */ |
141 | nbytes = sizeof (idb); |
142 | buflen = max(va.va_blocksize, nbytes); |
143 | oldcall = 1; |
144 | } else { |
145 | buflen = min(MAXBSIZE, nbytes); |
146 | if (buflen < va.va_blocksize) |
147 | buflen = va.va_blocksize; |
148 | oldcall = 0; |
149 | } |
150 | tbuf = malloc(buflen, M_TEMP, M_WAITOK); |
151 | |
152 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
153 | off = fp->f_offset; |
154 | again: |
155 | aiov.iov_base = tbuf; |
156 | aiov.iov_len = buflen; |
157 | auio.uio_iov = &aiov; |
158 | auio.uio_iovcnt = 1; |
159 | auio.uio_rw = UIO_READ; |
160 | auio.uio_resid = buflen; |
161 | auio.uio_offset = off; |
162 | UIO_SETUP_SYSSPACE(&auio); |
163 | /* |
164 | * First we read into the malloc'ed buffer, then |
165 | * we massage it into user space, one record at a time. |
166 | */ |
167 | error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf, |
168 | &ncookies); |
169 | if (error) |
170 | goto out; |
171 | |
172 | inp = tbuf; |
173 | outp = (void *)SCARG_P32(uap, dent); |
174 | resid = nbytes; |
175 | if ((len = buflen - auio.uio_resid) == 0) |
176 | goto eof; |
177 | |
178 | for (cookie = cookiebuf; len > 0; len -= reclen) { |
179 | bdp = (struct dirent *)inp; |
180 | reclen = bdp->d_reclen; |
181 | if (reclen & 3) |
182 | panic("linux32_readdir" ); |
183 | if (bdp->d_fileno == 0) { |
184 | inp += reclen; /* it is a hole; squish it out */ |
185 | if (cookie) |
186 | off = *cookie++; |
187 | else |
188 | off += reclen; |
189 | continue; |
190 | } |
191 | linux32_reclen = LINUX_RECLEN(&idb, bdp->d_namlen); |
192 | if (reclen > len || resid < linux32_reclen) { |
193 | /* entry too big for buffer, so just stop */ |
194 | outp++; |
195 | break; |
196 | } |
197 | /* |
198 | * Massage in place to make a Linux-shaped dirent (otherwise |
199 | * we have to worry about touching user memory outside of |
200 | * the copyout() call). |
201 | */ |
202 | idb.d_ino = bdp->d_fileno; |
203 | /* |
204 | * The old readdir() call misuses the offset and reclen fields. |
205 | */ |
206 | if (oldcall) { |
207 | idb.d_off = (linux32_off_t)linux32_reclen; |
208 | idb.d_reclen = (u_short)bdp->d_namlen; |
209 | } else { |
210 | if (sizeof (idb.d_off) <= 4 && (off >> 32) != 0) { |
211 | compat_offseterr(vp, "linux32_getdents" ); |
212 | error = EINVAL; |
213 | goto out; |
214 | } |
215 | idb.d_off = (linux32_off_t)off; |
216 | idb.d_reclen = (u_short)linux32_reclen; |
217 | } |
218 | strcpy(idb.d_name, bdp->d_name); |
219 | idb.d_name[strlen(idb.d_name) + 1] = bdp->d_type; |
220 | if ((error = copyout((void *)&idb, outp, linux32_reclen))) |
221 | goto out; |
222 | /* advance past this real entry */ |
223 | inp += reclen; |
224 | if (cookie) |
225 | off = *cookie++; /* each entry points to itself */ |
226 | else |
227 | off += reclen; |
228 | /* advance output past Linux-shaped entry */ |
229 | outp += linux32_reclen; |
230 | resid -= linux32_reclen; |
231 | if (oldcall) |
232 | break; |
233 | } |
234 | |
235 | /* if we squished out the whole block, try again */ |
236 | if (outp == (void *)SCARG_P32(uap, dent)) { |
237 | if (cookiebuf) |
238 | free(cookiebuf, M_TEMP); |
239 | cookiebuf = NULL; |
240 | goto again; |
241 | } |
242 | fp->f_offset = off; /* update the vnode offset */ |
243 | |
244 | if (oldcall) |
245 | nbytes = resid + linux32_reclen; |
246 | |
247 | eof: |
248 | *retval = nbytes - resid; |
249 | out: |
250 | VOP_UNLOCK(vp); |
251 | if (cookiebuf) |
252 | free(cookiebuf, M_TEMP); |
253 | free(tbuf, M_TEMP); |
254 | out1: |
255 | fd_putfile(SCARG(uap, fd)); |
256 | return error; |
257 | } |
258 | |
259 | int |
260 | linux32_sys_getdents64(struct lwp *l, const struct linux32_sys_getdents64_args *uap, register_t *retval) |
261 | { |
262 | /* { |
263 | syscallarg(int) fd; |
264 | syscallarg(linux32_dirent64p_t) dent; |
265 | syscallarg(unsigned int) count; |
266 | } */ |
267 | struct linux_sys_getdents64_args ua; |
268 | |
269 | NETBSD32TO64_UAP(fd); |
270 | NETBSD32TOP_UAP(dent, struct linux_dirent64); |
271 | NETBSD32TO64_UAP(count); |
272 | |
273 | return linux_sys_getdents64(l, &ua, retval); |
274 | } |
275 | |
276 | int |
277 | linux32_sys_readdir(struct lwp *l, const struct linux32_sys_readdir_args *uap, register_t *retval) |
278 | { |
279 | /* { |
280 | syscallarg(int) fd; |
281 | syscallarg(struct linux32_direntp_t) dent; |
282 | syscallarg(unsigned int) count; |
283 | } */ |
284 | int error; |
285 | struct linux32_sys_getdents_args da; |
286 | |
287 | SCARG(&da, fd) = SCARG(uap, fd); |
288 | SCARG(&da, dent) = SCARG(uap, dent); |
289 | SCARG(&da, count) = 1; |
290 | |
291 | error = linux32_sys_getdents(l, &da, retval); |
292 | if (error == 0 && *retval > 1) |
293 | *retval = 1; |
294 | |
295 | return error; |
296 | } |
297 | |