xref: /netbsd-src/sys/compat/common/vfs_syscalls_12.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: vfs_syscalls_12.c,v 1.37 2019/01/27 02:08:39 pgoyette Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	From: @(#)vfs_syscalls.c	8.28 (Berkeley) 12/10/94
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: vfs_syscalls_12.c,v 1.37 2019/01/27 02:08:39 pgoyette Exp $");
41 
42 #if defined(_KERNEL_OPT)
43 #include "opt_compat_netbsd.h"
44 #endif
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/namei.h>
49 #include <sys/filedesc.h>
50 #include <sys/kernel.h>
51 #include <sys/file.h>
52 #include <sys/stat.h>
53 #include <sys/socketvar.h>
54 #include <sys/vnode.h>
55 #include <sys/proc.h>
56 #include <sys/uio.h>
57 #include <sys/dirent.h>
58 #include <sys/vfs_syscalls.h>
59 
60 #include <sys/syscall.h>
61 #include <sys/syscallvar.h>
62 #include <sys/syscallargs.h>
63 
64 #include <compat/sys/stat.h>
65 #include <compat/sys/dirent.h>
66 
67 #include <compat/common/compat_mod.h>
68 
69 static const struct syscall_package vfs_syscalls_12_syscalls[] = {
70 	{ SYS_compat_12_fstat12, 0, (sy_call_t *)compat_12_sys_fstat },
71 	{ SYS_compat_12_getdirentries, 0,
72 	    (sy_call_t *)compat_12_sys_getdirentries },
73 	{ SYS_compat_12_lstat12, 0, (sy_call_t *)compat_12_sys_lstat },
74 	{ SYS_compat_12_stat12, 0, (sy_call_t *)compat_12_sys_stat },
75 	{ 0, 0, NULL }
76 };
77 
78 /*
79  * Convert from a new to an old stat structure.
80  */
81 void
82 compat_12_stat_conv(const struct stat *st, struct stat12 *ost)
83 {
84 
85 	ost->st_dev = st->st_dev;
86 	ost->st_ino = st->st_ino;
87 	ost->st_mode = st->st_mode & 0xffff;
88 	if (st->st_nlink >= (1 << 15))
89 		ost->st_nlink = (1 << 15) - 1;
90 	else
91 		ost->st_nlink = st->st_nlink;
92 	ost->st_uid = st->st_uid;
93 	ost->st_gid = st->st_gid;
94 	ost->st_rdev = st->st_rdev;
95 	timespec_to_timespec50(&st->st_atimespec, &ost->st_atimespec);
96 	timespec_to_timespec50(&st->st_mtimespec, &ost->st_mtimespec);
97 	timespec_to_timespec50(&st->st_ctimespec, &ost->st_ctimespec);
98 	ost->st_size = st->st_size;
99 	ost->st_blocks = st->st_blocks;
100 	ost->st_blksize = st->st_blksize;
101 	ost->st_flags = st->st_flags;
102 	ost->st_gen = st->st_gen;
103 }
104 
105 /*
106  * Read a block of directory entries in a file system independent format.
107  */
108 int
109 compat_12_sys_getdirentries(struct lwp *l,
110     const struct compat_12_sys_getdirentries_args *uap, register_t *retval)
111 {
112 	/* {
113 		syscallarg(int) fd;
114 		syscallarg(char *) buf;
115 		syscallarg(u_int) count;
116 		syscallarg(long *) basep;
117 	} */
118 	struct dirent *bdp;
119 	struct vnode *vp;
120 	char *inp, *tbuf;		/* Current-format */
121 	int len, reclen;		/* Current-format */
122 	char *outp;			/* Dirent12-format */
123 	int resid, old_reclen = 0;	/* Dirent12-format */
124 	struct file *fp;
125 	struct uio auio;
126 	struct iovec aiov;
127 	struct dirent12 idb;
128 	off_t off;		/* true file offset */
129 	int buflen, error, eofflag, nbytes;
130 	struct vattr va;
131 	off_t *cookiebuf = NULL, *cookie;
132 	int ncookies;
133 	long loff;
134 
135 	/* fd_getvnode() will use the descriptor for us */
136 	if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0)
137 		return (error);
138 
139 	if ((fp->f_flag & FREAD) == 0) {
140 		error = EBADF;
141 		goto out1;
142 	}
143 
144 	vp = (struct vnode *)fp->f_vnode;
145 	if (vp->v_type != VDIR) {
146 		error = ENOTDIR;
147 		goto out1;
148 	}
149 
150 	vn_lock(vp, LK_SHARED | LK_RETRY);
151 	error = VOP_GETATTR(vp, &va, l->l_cred);
152 	VOP_UNLOCK(vp);
153 	if (error)
154 		goto out1;
155 
156 	loff = fp->f_offset;
157 	nbytes = SCARG(uap, count);
158 	buflen = uimin(MAXBSIZE, nbytes);
159 	if (buflen < va.va_blocksize)
160 		buflen = va.va_blocksize;
161 	tbuf = malloc(buflen, M_TEMP, M_WAITOK);
162 
163 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
164 	off = fp->f_offset;
165 again:
166 	aiov.iov_base = tbuf;
167 	aiov.iov_len = buflen;
168 	auio.uio_iov = &aiov;
169 	auio.uio_iovcnt = 1;
170 	auio.uio_rw = UIO_READ;
171 	auio.uio_resid = buflen;
172 	auio.uio_offset = off;
173 	UIO_SETUP_SYSSPACE(&auio);
174 	/*
175          * First we read into the malloc'ed buffer, then
176          * we massage it into user space, one record at a time.
177          */
178 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
179 	    &ncookies);
180 	if (error)
181 		goto out;
182 
183 	inp = tbuf;
184 	outp = SCARG(uap, buf);
185 	resid = nbytes;
186 	if ((len = buflen - auio.uio_resid) == 0)
187 		goto eof;
188 
189 	for (cookie = cookiebuf; len > 0; len -= reclen) {
190 		bdp = (struct dirent *)inp;
191 		reclen = bdp->d_reclen;
192 		if (reclen & 3) {
193 			error = EIO;
194 			goto out;
195 		}
196 		if (bdp->d_fileno == 0) {
197 			inp += reclen;	/* it is a hole; squish it out */
198 			if (cookie)
199 				off = *cookie++;
200 			else
201 				off += reclen;
202 			continue;
203 		}
204 		if (bdp->d_namlen >= sizeof(idb.d_name))
205 			idb.d_namlen = sizeof(idb.d_name) - 1;
206 		else
207 			idb.d_namlen = bdp->d_namlen;
208 		old_reclen = _DIRENT_RECLEN(&idb, bdp->d_namlen);
209 		if (reclen > len || resid < old_reclen) {
210 			/* entry too big for buffer, so just stop */
211 			outp++;
212 			break;
213 		}
214 		/*
215 		 * Massage in place to make a Dirent12-shaped dirent (otherwise
216 		 * we have to worry about touching user memory outside of
217 		 * the copyout() call).
218 		 */
219 		idb.d_fileno = (uint32_t)bdp->d_fileno;
220 		idb.d_reclen = (uint16_t)old_reclen;
221 		idb.d_type = (uint8_t)bdp->d_type;
222 		(void)memcpy(idb.d_name, bdp->d_name, idb.d_namlen);
223 		memset(idb.d_name + idb.d_namlen, 0,
224 		    idb.d_reclen - _DIRENT_NAMEOFF(&idb) - idb.d_namlen);
225 		if ((error = copyout(&idb, outp, old_reclen)))
226 			goto out;
227 		/* advance past this real entry */
228 		inp += reclen;
229 		if (cookie)
230 			off = *cookie++; /* each entry points to itself */
231 		else
232 			off += reclen;
233 		/* advance output past Dirent12-shaped entry */
234 		outp += old_reclen;
235 		resid -= old_reclen;
236 	}
237 
238 	/* if we squished out the whole block, try again */
239 	if (outp == SCARG(uap, buf)) {
240 		if (cookiebuf)
241 			free(cookiebuf, M_TEMP);
242 		cookiebuf = NULL;
243 		goto again;
244 	}
245 	fp->f_offset = off;	/* update the vnode offset */
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 	if (error)
257 		return error;
258 	return copyout(&loff, SCARG(uap, basep), sizeof(long));
259 }
260 
261 /*
262  * Get file status; this version follows links.
263  */
264 /* ARGSUSED */
265 int
266 compat_12_sys_stat(struct lwp *l, const struct compat_12_sys_stat_args *uap,
267     register_t *retval)
268 {
269 	/* {
270 		syscallarg(const char *) path;
271 		syscallarg(struct stat12 *) ub;
272 	} */
273 	struct stat sb;
274 	struct stat12 osb;
275 	int error;
276 
277 	error = do_sys_stat(SCARG(uap, path), FOLLOW, &sb);
278 	if (error)
279 		return (error);
280 	compat_12_stat_conv(&sb, &osb);
281 	error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
282 	return (error);
283 }
284 
285 
286 /*
287  * Get file status; this version does not follow links.
288  */
289 /* ARGSUSED */
290 int
291 compat_12_sys_lstat(struct lwp *l, const struct compat_12_sys_lstat_args *uap,
292     register_t *retval)
293 {
294 	/* {
295 		syscallarg(const char *) path;
296 		syscallarg(struct stat12 *) ub;
297 	} */
298 	struct stat sb;
299 	struct stat12 osb;
300 	int error;
301 
302 	error = do_sys_stat(SCARG(uap, path), NOFOLLOW, &sb);
303 	if (error)
304 		return (error);
305 	compat_12_stat_conv(&sb, &osb);
306 	error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
307 	return (error);
308 }
309 
310 /*
311  * Return status information about a file descriptor.
312  */
313 /* ARGSUSED */
314 int
315 compat_12_sys_fstat(struct lwp *l, const struct compat_12_sys_fstat_args *uap,
316     register_t *retval)
317 {
318 	/* {
319 		syscallarg(int) fd;
320 		syscallarg(struct stat12 *) sb;
321 	} */
322 	struct stat ub;
323 	struct stat12 oub;
324 	int error;
325 
326 	error = do_sys_fstat(SCARG(uap, fd), &ub);
327 	if (error == 0) {
328 		compat_12_stat_conv(&ub, &oub);
329 		error = copyout(&oub, SCARG(uap, sb), sizeof (oub));
330 	}
331 	return (error);
332 }
333 
334 int
335 vfs_syscalls_12_init(void)
336 {
337 
338 	return syscall_establish(NULL, vfs_syscalls_12_syscalls);
339 }
340 
341 int
342 vfs_syscalls_12_fini(void)
343 {
344 
345 	return syscall_disestablish(NULL, vfs_syscalls_12_syscalls);
346 }
347