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linux_file64.c revision 1.18
      1 /*	$NetBSD: linux_file64.c,v 1.18 2002/05/20 06:45:11 jdolecek Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1995, 1998, 2000 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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Linux 64bit filesystem calls. Used on 32bit archs, not used on 64bit ones.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: linux_file64.c,v 1.18 2002/05/20 06:45:11 jdolecek Exp $");
     45 
     46 #include <sys/param.h>
     47 #include <sys/systm.h>
     48 #include <sys/namei.h>
     49 #include <sys/proc.h>
     50 #include <sys/dirent.h>
     51 #include <sys/file.h>
     52 #include <sys/stat.h>
     53 #include <sys/filedesc.h>
     54 #include <sys/ioctl.h>
     55 #include <sys/kernel.h>
     56 #include <sys/mount.h>
     57 #include <sys/malloc.h>
     58 #include <sys/vnode.h>
     59 #include <sys/tty.h>
     60 #include <sys/conf.h>
     61 
     62 #include <sys/syscallargs.h>
     63 
     64 #include <compat/linux/common/linux_types.h>
     65 #include <compat/linux/common/linux_signal.h>
     66 #include <compat/linux/common/linux_fcntl.h>
     67 #include <compat/linux/common/linux_util.h>
     68 #include <compat/linux/common/linux_machdep.h>
     69 #include <compat/linux/common/linux_dirent.h>
     70 
     71 #include <compat/linux/linux_syscallargs.h>
     72 
     73 #ifndef alpha
     74 
     75 static void bsd_to_linux_stat __P((struct stat *, struct linux_stat64 *));
     76 static int linux_do_stat64 __P((struct proc *, void *, register_t *, int));
     77 
     78 /*
     79  * Convert a NetBSD stat structure to a Linux stat structure.
     80  * Only the order of the fields and the padding in the structure
     81  * is different. linux_fakedev is a machine-dependent function
     82  * which optionally converts device driver major/minor numbers
     83  * (XXX horrible, but what can you do against code that compares
     84  * things against constant major device numbers? sigh)
     85  */
     86 static void
     87 bsd_to_linux_stat(bsp, lsp)
     88 	struct stat *bsp;
     89 	struct linux_stat64 *lsp;
     90 {
     91 	lsp->lst_dev     = linux_fakedev(bsp->st_dev, 0);
     92 	lsp->lst_ino     = bsp->st_ino;
     93 	lsp->lst_mode    = (linux_mode_t)bsp->st_mode;
     94 	if (bsp->st_nlink >= (1 << 15))
     95 		lsp->lst_nlink = (1 << 15) - 1;
     96 	else
     97 		lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
     98 	lsp->lst_uid     = bsp->st_uid;
     99 	lsp->lst_gid     = bsp->st_gid;
    100 	lsp->lst_rdev    = linux_fakedev(bsp->st_rdev, 1);
    101 	lsp->lst_size    = bsp->st_size;
    102 	lsp->lst_blksize = bsp->st_blksize;
    103 	lsp->lst_blocks  = bsp->st_blocks;
    104 	lsp->lst_atime   = bsp->st_atime;
    105 	lsp->lst_mtime   = bsp->st_mtime;
    106 	lsp->lst_ctime   = bsp->st_ctime;
    107 #if LINUX_STAT64_HAS_BROKEN_ST_INO
    108 	lsp->__lst_ino   = (linux_ino_t) bsp->st_ino;
    109 #endif
    110 }
    111 
    112 /*
    113  * The stat functions below are plain sailing. stat and lstat are handled
    114  * by one function to avoid code duplication.
    115  */
    116 int
    117 linux_sys_fstat64(p, v, retval)
    118 	struct proc *p;
    119 	void *v;
    120 	register_t *retval;
    121 {
    122 	struct linux_sys_fstat64_args /* {
    123 		syscallarg(int) fd;
    124 		syscallarg(struct linux_stat64 *) sp;
    125 	} */ *uap = v;
    126 	struct sys___fstat13_args fsa;
    127 	struct linux_stat64 tmplst;
    128 	struct stat *st,tmpst;
    129 	caddr_t sg;
    130 	int error;
    131 
    132 	sg = stackgap_init(p, 0);
    133 
    134 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    135 
    136 	SCARG(&fsa, fd) = SCARG(uap, fd);
    137 	SCARG(&fsa, sb) = st;
    138 
    139 	if ((error = sys___fstat13(p, &fsa, retval)))
    140 		return error;
    141 
    142 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    143 		return error;
    144 
    145 	bsd_to_linux_stat(&tmpst, &tmplst);
    146 
    147 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    148 		return error;
    149 
    150 	return 0;
    151 }
    152 
    153 static int
    154 linux_do_stat64(p, v, retval, dolstat)
    155 	struct proc *p;
    156 	void *v;
    157 	register_t *retval;
    158 	int dolstat;
    159 {
    160 	struct sys___stat13_args sa;
    161 	struct linux_stat64 tmplst;
    162 	struct stat *st, tmpst;
    163 	caddr_t sg;
    164 	int error;
    165 	struct linux_sys_stat64_args *uap = v;
    166 
    167 	sg = stackgap_init(p, 0);
    168 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    169 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    170 
    171 	SCARG(&sa, ub) = st;
    172 	SCARG(&sa, path) = SCARG(uap, path);
    173 
    174 	if ((error = (dolstat ? sys___lstat13(p, &sa, retval) :
    175 				sys___stat13(p, &sa, retval))))
    176 		return error;
    177 
    178 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    179 		return error;
    180 
    181 	bsd_to_linux_stat(&tmpst, &tmplst);
    182 
    183 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    184 		return error;
    185 
    186 	return 0;
    187 }
    188 
    189 int
    190 linux_sys_stat64(p, v, retval)
    191 	struct proc *p;
    192 	void *v;
    193 	register_t *retval;
    194 {
    195 	struct linux_sys_stat64_args /* {
    196 		syscallarg(const char *) path;
    197 		syscallarg(struct linux_stat64 *) sp;
    198 	} */ *uap = v;
    199 
    200 	return linux_do_stat64(p, uap, retval, 0);
    201 }
    202 
    203 int
    204 linux_sys_lstat64(p, v, retval)
    205 	struct proc *p;
    206 	void *v;
    207 	register_t *retval;
    208 {
    209 	struct linux_sys_lstat64_args /* {
    210 		syscallarg(const char *) path;
    211 		syscallarg(struct linux_stat64 *) sp;
    212 	} */ *uap = v;
    213 
    214 	return linux_do_stat64(p, uap, retval, 1);
    215 }
    216 
    217 int
    218 linux_sys_truncate64(p, v, retval)
    219 	struct proc *p;
    220 	void *v;
    221 	register_t *retval;
    222 {
    223 	struct linux_sys_truncate64_args /* {
    224 		syscallarg(const char *) path;
    225 		syscallarg(off_t) length;
    226 	} */ *uap = v;
    227 	caddr_t sg = stackgap_init(p, 0);
    228 
    229 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    230 
    231 	return sys_truncate(p, uap, retval);
    232 }
    233 
    234 #if !defined(__m68k__)
    235 static void bsd_to_linux_flock64 __P((struct linux_flock64 *,
    236     const struct flock *));
    237 static void linux_to_bsd_flock64 __P((struct flock *,
    238     const struct linux_flock64 *));
    239 
    240 static void
    241 bsd_to_linux_flock64(lfp, bfp)
    242 	struct linux_flock64 *lfp;
    243 	const struct flock *bfp;
    244 {
    245 
    246 	lfp->l_start = bfp->l_start;
    247 	lfp->l_len = bfp->l_len;
    248 	lfp->l_pid = bfp->l_pid;
    249 	lfp->l_whence = bfp->l_whence;
    250 	switch (bfp->l_type) {
    251 	case F_RDLCK:
    252 		lfp->l_type = LINUX_F_RDLCK;
    253 		break;
    254 	case F_UNLCK:
    255 		lfp->l_type = LINUX_F_UNLCK;
    256 		break;
    257 	case F_WRLCK:
    258 		lfp->l_type = LINUX_F_WRLCK;
    259 		break;
    260 	}
    261 }
    262 
    263 static void
    264 linux_to_bsd_flock64(bfp, lfp)
    265 	struct flock *bfp;
    266 	const struct linux_flock64 *lfp;
    267 {
    268 
    269 	bfp->l_start = lfp->l_start;
    270 	bfp->l_len = lfp->l_len;
    271 	bfp->l_pid = lfp->l_pid;
    272 	bfp->l_whence = lfp->l_whence;
    273 	switch (lfp->l_type) {
    274 	case LINUX_F_RDLCK:
    275 		bfp->l_type = F_RDLCK;
    276 		break;
    277 	case LINUX_F_UNLCK:
    278 		bfp->l_type = F_UNLCK;
    279 		break;
    280 	case LINUX_F_WRLCK:
    281 		bfp->l_type = F_WRLCK;
    282 		break;
    283 	}
    284 }
    285 
    286 int
    287 linux_sys_fcntl64(p, v, retval)
    288 	struct proc *p;
    289 	void *v;
    290 	register_t *retval;
    291 {
    292 	struct linux_sys_fcntl64_args /* {
    293 		syscallarg(int) fd;
    294 		syscallarg(int) cmd;
    295 		syscallarg(void *) arg;
    296 	} */ *uap = v;
    297 	struct sys_fcntl_args fca;
    298 	struct linux_flock64 lfl;
    299 	struct flock bfl, *bfp;
    300 	int error;
    301 	caddr_t sg;
    302 	void *arg = SCARG(uap, arg);
    303 	int cmd = SCARG(uap, cmd);
    304 	int fd = SCARG(uap, fd);
    305 
    306 	switch (cmd) {
    307 	case LINUX_F_GETLK64:
    308 		sg = stackgap_init(p, 0);
    309 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    310 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    311 			return error;
    312 		linux_to_bsd_flock64(&bfl, &lfl);
    313 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    314 			return error;
    315 		SCARG(&fca, fd) = fd;
    316 		SCARG(&fca, cmd) = F_GETLK;
    317 		SCARG(&fca, arg) = bfp;
    318 		if ((error = sys_fcntl(p, &fca, retval)) != 0)
    319 			return error;
    320 		if ((error = copyin(bfp, &bfl, sizeof bfl)) != 0)
    321 			return error;
    322 		bsd_to_linux_flock64(&lfl, &bfl);
    323 		return copyout(&lfl, arg, sizeof lfl);
    324 	case LINUX_F_SETLK64:
    325 	case LINUX_F_SETLKW64:
    326 		cmd = (cmd == LINUX_F_SETLK64 ? F_SETLK : F_SETLKW);
    327 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    328 			return error;
    329 		linux_to_bsd_flock64(&bfl, &lfl);
    330 		sg = stackgap_init(p, 0);
    331 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    332 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    333 			return error;
    334 		SCARG(&fca, fd) = fd;
    335 		SCARG(&fca, cmd) = cmd;
    336 		SCARG(&fca, arg) = bfp;
    337 		return sys_fcntl(p, &fca, retval);
    338 	default:
    339 		return linux_sys_fcntl(p, v, retval);
    340 	}
    341 }
    342 #endif /* !m68k */
    343 
    344 #endif /* !alpha */
    345 
    346 /*
    347  * Linux 'readdir' call. This code is mostly taken from the
    348  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    349  * an attempt has been made to keep it a little cleaner.
    350  *
    351  * The d_off field contains the offset of the next valid entry,
    352  * unless the older Linux getdents(2), which used to have it set
    353  * to the offset of the entry itself. This function also doesn't
    354  * need to deal with the old count == 1 glibc problem.
    355  *
    356  * Read in BSD-style entries, convert them, and copy them out.
    357  *
    358  * Note that this doesn't handle union-mounted filesystems.
    359  */
    360 int
    361 linux_sys_getdents64(p, v, retval)
    362 	struct proc *p;
    363 	void *v;
    364 	register_t *retval;
    365 {
    366 	struct linux_sys_getdents_args /* {
    367 		syscallarg(int) fd;
    368 		syscallarg(struct linux_dirent64 *) dent;
    369 		syscallarg(unsigned int) count;
    370 	} */ *uap = v;
    371 	struct dirent *bdp;
    372 	struct vnode *vp;
    373 	caddr_t	inp, buf;		/* BSD-format */
    374 	int len, reclen;		/* BSD-format */
    375 	caddr_t outp;			/* Linux-format */
    376 	int resid, linux_reclen = 0;	/* Linux-format */
    377 	struct file *fp;
    378 	struct uio auio;
    379 	struct iovec aiov;
    380 	struct linux_dirent64 idb;
    381 	off_t off;		/* true file offset */
    382 	int buflen, error, eofflag, nbytes;
    383 	struct vattr va;
    384 	off_t *cookiebuf = NULL, *cookie;
    385 	int ncookies;
    386 
    387 	/* getvnode() will use the descriptor for us */
    388 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    389 		return (error);
    390 
    391 	if ((fp->f_flag & FREAD) == 0) {
    392 		error = EBADF;
    393 		goto out1;
    394 	}
    395 
    396 	vp = (struct vnode *)fp->f_data;
    397 	if (vp->v_type != VDIR) {
    398 		error = EINVAL;
    399 		goto out1;
    400 	}
    401 
    402 	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
    403 		goto out1;
    404 
    405 	nbytes = SCARG(uap, count);
    406 	buflen = min(MAXBSIZE, nbytes);
    407 	if (buflen < va.va_blocksize)
    408 		buflen = va.va_blocksize;
    409 	buf = malloc(buflen, M_TEMP, M_WAITOK);
    410 
    411 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    412 	off = fp->f_offset;
    413 again:
    414 	aiov.iov_base = buf;
    415 	aiov.iov_len = buflen;
    416 	auio.uio_iov = &aiov;
    417 	auio.uio_iovcnt = 1;
    418 	auio.uio_rw = UIO_READ;
    419 	auio.uio_segflg = UIO_SYSSPACE;
    420 	auio.uio_procp = p;
    421 	auio.uio_resid = buflen;
    422 	auio.uio_offset = off;
    423 	/*
    424          * First we read into the malloc'ed buffer, then
    425          * we massage it into user space, one record at a time.
    426          */
    427 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    428 	    &ncookies);
    429 	if (error)
    430 		goto out;
    431 
    432 	inp = buf;
    433 	outp = (caddr_t)SCARG(uap, dent);
    434 	resid = nbytes;
    435 	if ((len = buflen - auio.uio_resid) == 0)
    436 		goto eof;
    437 
    438 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    439 		bdp = (struct dirent *)inp;
    440 		reclen = bdp->d_reclen;
    441 		if (reclen & 3)
    442 			panic("linux_readdir");
    443 		if (bdp->d_fileno == 0) {
    444 			inp += reclen;	/* it is a hole; squish it out */
    445 			off = *cookie++;
    446 			continue;
    447 		}
    448 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    449 		if (reclen > len || resid < linux_reclen) {
    450 			/* entry too big for buffer, so just stop */
    451 			outp++;
    452 			break;
    453 		}
    454 		off = *cookie++;	/* each entry points to next */
    455 		/*
    456 		 * Massage in place to make a Linux-shaped dirent (otherwise
    457 		 * we have to worry about touching user memory outside of
    458 		 * the copyout() call).
    459 		 */
    460 		idb.d_ino = bdp->d_fileno;
    461 		idb.d_type = bdp->d_type;
    462 		idb.d_off = off;
    463 		idb.d_reclen = (u_short)linux_reclen;
    464 		strcpy(idb.d_name, bdp->d_name);
    465 		if ((error = copyout((caddr_t)&idb, outp, linux_reclen)))
    466 			goto out;
    467 		/* advance past this real entry */
    468 		inp += reclen;
    469 		/* advance output past Linux-shaped entry */
    470 		outp += linux_reclen;
    471 		resid -= linux_reclen;
    472 	}
    473 
    474 	/* if we squished out the whole block, try again */
    475 	if (outp == (caddr_t)SCARG(uap, dent))
    476 		goto again;
    477 	fp->f_offset = off;	/* update the vnode offset */
    478 
    479 eof:
    480 	*retval = nbytes - resid;
    481 out:
    482 	VOP_UNLOCK(vp, 0);
    483 	if (cookiebuf)
    484 		free(cookiebuf, M_TEMP);
    485 	free(buf, M_TEMP);
    486 out1:
    487 	FILE_UNUSE(fp, p);
    488 	return error;
    489 }
    490