1/* $NetBSD: linux_file64.c,v 1.55 2013/12/27 14:17:11 njoly Exp $ */
2
3/*-
4 * Copyright (c) 1995, 1998, 2000, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Frank van der Linden and Eric Haszlakiewicz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Linux 64bit filesystem calls. Used on 32bit archs, not used on 64bit ones.
34 */
35
36#include <sys/cdefs.h>
37__KERNEL_RCSID(0, "$NetBSD: linux_file64.c,v 1.55 2013/12/27 14:17:11 njoly Exp $");
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/namei.h>
42#include <sys/proc.h>
43#include <sys/dirent.h>
44#include <sys/file.h>
45#include <sys/stat.h>
46#include <sys/filedesc.h>
47#include <sys/ioctl.h>
48#include <sys/kernel.h>
49#include <sys/mount.h>
50#include <sys/malloc.h>
51#include <sys/namei.h>
52#include <sys/vfs_syscalls.h>
53#include <sys/vnode.h>
54#include <sys/tty.h>
55#include <sys/conf.h>
56
57#include <sys/syscallargs.h>
58
59#include <compat/linux/common/linux_types.h>
60#include <compat/linux/common/linux_signal.h>
61#include <compat/linux/common/linux_fcntl.h>
62#include <compat/linux/common/linux_util.h>
63#include <compat/linux/common/linux_machdep.h>
64#include <compat/linux/common/linux_dirent.h>
65#include <compat/linux/common/linux_ipc.h>
66#include <compat/linux/common/linux_sem.h>
67
68#include <compat/linux/linux_syscallargs.h>
69
70static void bsd_to_linux_stat(struct stat *, struct linux_stat64 *);
71
72/*
73 * Convert a NetBSD stat structure to a Linux stat structure.
74 * Only the order of the fields and the padding in the structure
75 * is different. linux_fakedev is a machine-dependent function
76 * which optionally converts device driver major/minor numbers
77 * (XXX horrible, but what can you do against code that compares
78 * things against constant major device numbers? sigh)
79 */
80static void
81bsd_to_linux_stat(struct stat *bsp, struct linux_stat64 *lsp)
82{
83 lsp->lst_dev = linux_fakedev(bsp->st_dev, 0);
84 lsp->lst_ino = bsp->st_ino;
85 lsp->lst_mode = (linux_mode_t)bsp->st_mode;
86 if (bsp->st_nlink >= (1 << 15))
87 lsp->lst_nlink = (1 << 15) - 1;
88 else
89 lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
90 lsp->lst_uid = bsp->st_uid;
91 lsp->lst_gid = bsp->st_gid;
92 lsp->lst_rdev = linux_fakedev(bsp->st_rdev, 1);
93 lsp->lst_size = bsp->st_size;
94 lsp->lst_blksize = bsp->st_blksize;
95 lsp->lst_blocks = bsp->st_blocks;
96 lsp->lst_atime = bsp->st_atime;
97 lsp->lst_mtime = bsp->st_mtime;
98 lsp->lst_ctime = bsp->st_ctime;
99# ifdef LINUX_STAT64_HAS_NSEC
100 lsp->lst_atime_nsec = bsp->st_atimensec;
101 lsp->lst_mtime_nsec = bsp->st_mtimensec;
102 lsp->lst_ctime_nsec = bsp->st_ctimensec;
103# endif
104# if LINUX_STAT64_HAS_BROKEN_ST_INO
105 lsp->__lst_ino = (linux_ino_t) bsp->st_ino;
106# endif
107}
108
109/*
110 * The stat functions below are plain sailing. stat and lstat are handled
111 * by one function to avoid code duplication.
112 */
113int
114linux_sys_fstat64(struct lwp *l, const struct linux_sys_fstat64_args *uap, register_t *retval)
115{
116 /* {
117 syscallarg(int) fd;
118 syscallarg(struct linux_stat64 *) sp;
119 } */
120 struct linux_stat64 tmplst;
121 struct stat tmpst;
122 int error;
123
124 error = do_sys_fstat(SCARG(uap, fd), &tmpst);
125 if (error != 0)
126 return error;
127
128 bsd_to_linux_stat(&tmpst, &tmplst);
129
130 return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
131}
132
133static int
134linux_do_stat64(struct lwp *l, const struct linux_sys_stat64_args *uap, register_t *retval, int flags)
135{
136 struct linux_stat64 tmplst;
137 struct stat tmpst;
138 int error;
139
140 error = do_sys_stat(SCARG(uap, path), flags, &tmpst);
141 if (error != 0)
142 return error;
143
144 bsd_to_linux_stat(&tmpst, &tmplst);
145
146 return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
147}
148
149int
150linux_sys_stat64(struct lwp *l, const struct linux_sys_stat64_args *uap, register_t *retval)
151{
152 /* {
153 syscallarg(const char *) path;
154 syscallarg(struct linux_stat64 *) sp;
155 } */
156
157 return linux_do_stat64(l, uap, retval, FOLLOW);
158}
159
160int
161linux_sys_lstat64(struct lwp *l, const struct linux_sys_lstat64_args *uap, register_t *retval)
162{
163 /* {
164 syscallarg(const char *) path;
165 syscallarg(struct linux_stat64 *) sp;
166 } */
167
168 return linux_do_stat64(l, (const void *)uap, retval, NOFOLLOW);
169}
170
171int
172linux_sys_fstatat64(struct lwp *l, const struct linux_sys_fstatat64_args *uap, register_t *retval)
173{
174 /* {
175 syscallarg(int) fd;
176 syscallarg(const char *) path;
177 syscallarg(struct linux_stat64 *) sp;
178 syscallarg(int) flag;
179 } */
180 struct linux_stat64 tmplst;
181 struct stat tmpst;
182 int error, nd_flag;
183
184 if (SCARG(uap, flag) & LINUX_AT_SYMLINK_NOFOLLOW)
185 nd_flag = NOFOLLOW;
186 else
187 nd_flag = FOLLOW;
188
189 error = do_sys_statat(l, SCARG(uap, fd), SCARG(uap, path), nd_flag, &tmpst);
190 if (error != 0)
191 return error;
192
193 bsd_to_linux_stat(&tmpst, &tmplst);
194
195 return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
196}
197
198#ifndef __alpha__
199int
200linux_sys_truncate64(struct lwp *l, const struct linux_sys_truncate64_args *uap, register_t *retval)
201{
202 /* {
203 syscallarg(const char *) path;
204 syscallarg(off_t) length;
205 } */
206 struct sys_truncate_args ta;
207
208 /* Linux doesn't have the 'pad' pseudo-parameter */
209 SCARG(&ta, path) = SCARG(uap, path);
210 SCARG(&ta, PAD) = 0;
211 SCARG(&ta, length) = SCARG(uap, length);
212
213 return sys_truncate(l, &ta, retval);
214}
215
216int
217linux_sys_ftruncate64(struct lwp *l, const struct linux_sys_ftruncate64_args *uap, register_t *retval)
218{
219 /* {
220 syscallarg(unsigned int) fd;
221 syscallarg(off_t) length;
222 } */
223 struct sys_ftruncate_args ta;
224
225 /* Linux doesn't have the 'pad' pseudo-parameter */
226 SCARG(&ta, fd) = SCARG(uap, fd);
227 SCARG(&ta, PAD) = 0;
228 SCARG(&ta, length) = SCARG(uap, length);
229
230 return sys_ftruncate(l, &ta, retval);
231}
232#endif /* __alpha__ */
233
234/*
235 * Linux 'readdir' call. This code is mostly taken from the
236 * SunOS getdents call (see compat/sunos/sunos_misc.c), though
237 * an attempt has been made to keep it a little cleaner.
238 *
239 * The d_off field contains the offset of the next valid entry,
240 * unless the older Linux getdents(2), which used to have it set
241 * to the offset of the entry itself. This function also doesn't
242 * need to deal with the old count == 1 glibc problem.
243 *
244 * Read in BSD-style entries, convert them, and copy them out.
245 *
246 * Note that this doesn't handle union-mounted filesystems.
247 */
248int
249linux_sys_getdents64(struct lwp *l, const struct linux_sys_getdents64_args *uap, register_t *retval)
250{
251 /* {
252 syscallarg(int) fd;
253 syscallarg(struct linux_dirent64 *) dent;
254 syscallarg(unsigned int) count;
255 } */
256 struct dirent *bdp;
257 struct vnode *vp;
258 char *inp, *tbuf; /* BSD-format */
259 int len, reclen; /* BSD-format */
260 char *outp; /* Linux-format */
261 int resid, linux_reclen = 0; /* Linux-format */
262 file_t *fp;
263 struct uio auio;
264 struct iovec aiov;
265 struct linux_dirent64 idb;
266 off_t off; /* true file offset */
267 int buflen, error, eofflag, nbytes;
268 struct vattr va;
269 off_t *cookiebuf = NULL, *cookie;
270 int ncookies;
271
272 /* fd_getvnode() will use the descriptor for us */
273 if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0)
274 return (error);
275
276 if ((fp->f_flag & FREAD) == 0) {
277 error = EBADF;
278 goto out1;
279 }
280
281 vp = (struct vnode *)fp->f_data;
282 if (vp->v_type != VDIR) {
283 error = ENOTDIR;
284 goto out1;
285 }
286
287 vn_lock(vp, LK_SHARED | LK_RETRY);
288 error = VOP_GETATTR(vp, &va, l->l_cred);
289 VOP_UNLOCK(vp);
290 if (error)
291 goto out1;
292
293 nbytes = SCARG(uap, count);
294 buflen = min(MAXBSIZE, nbytes);
295 if (buflen < va.va_blocksize)
296 buflen = va.va_blocksize;
297 tbuf = malloc(buflen, M_TEMP, M_WAITOK);
298
299 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
300 off = fp->f_offset;
301again:
302 aiov.iov_base = tbuf;
303 aiov.iov_len = buflen;
304 auio.uio_iov = &aiov;
305 auio.uio_iovcnt = 1;
306 auio.uio_rw = UIO_READ;
307 auio.uio_resid = buflen;
308 auio.uio_offset = off;
309 UIO_SETUP_SYSSPACE(&auio);
310 /*
311 * First we read into the malloc'ed buffer, then
312 * we massage it into user space, one record at a time.
313 */
314 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
315 &ncookies);
316 if (error)
317 goto out;
318
319 inp = tbuf;
320 outp = (void *)SCARG(uap, dent);
321 resid = nbytes;
322 if ((len = buflen - auio.uio_resid) == 0)
323 goto eof;
324
325 for (cookie = cookiebuf; len > 0; len -= reclen) {
326 bdp = (struct dirent *)inp;
327 reclen = bdp->d_reclen;
328 if (reclen & 3)
329 panic("linux_readdir");
330 if (bdp->d_fileno == 0) {
331 inp += reclen; /* it is a hole; squish it out */
332 if (cookie)
333 off = *cookie++;
334 else
335 off += reclen;
336 continue;
337 }
338 linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
339 if (reclen > len || resid < linux_reclen) {
340 /* entry too big for buffer, so just stop */
341 outp++;
342 break;
343 }
344 if (cookie)
345 off = *cookie++; /* each entry points to next */
346 else
347 off += reclen;
348 /*
349 * Massage in place to make a Linux-shaped dirent (otherwise
350 * we have to worry about touching user memory outside of
351 * the copyout() call).
352 */
353 idb.d_ino = bdp->d_fileno;
354 idb.d_type = bdp->d_type;
355 idb.d_off = off;
356 idb.d_reclen = (u_short)linux_reclen;
357 strcpy(idb.d_name, bdp->d_name);
358 if ((error = copyout((void *)&idb, outp, linux_reclen)))
359 goto out;
360 /* advance past this real entry */
361 inp += reclen;
362 /* advance output past Linux-shaped entry */
363 outp += linux_reclen;
364 resid -= linux_reclen;
365 }
366
367 /* if we squished out the whole block, try again */
368 if (outp == (void *)SCARG(uap, dent)) {
369 if (cookiebuf)
370 free(cookiebuf, M_TEMP);
371 cookiebuf = NULL;
372 goto again;
373 }
374 fp->f_offset = off; /* update the vnode offset */
375
376eof:
377 *retval = nbytes - resid;
378out:
379 VOP_UNLOCK(vp);
380 if (cookiebuf)
381 free(cookiebuf, M_TEMP);
382 free(tbuf, M_TEMP);
383out1:
384 fd_putfile(SCARG(uap, fd));
385 return error;
386}
387