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linux_file64.c revision 1.27
      1 /*	$NetBSD: linux_file64.c,v 1.27 2005/05/03 16:26:28 manu 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 1.27 2005/05/03 16:26:28 manu 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/sa.h>
     63 #include <sys/syscallargs.h>
     64 
     65 #include <compat/linux/common/linux_types.h>
     66 #include <compat/linux/common/linux_signal.h>
     67 #include <compat/linux/common/linux_fcntl.h>
     68 #include <compat/linux/common/linux_util.h>
     69 #include <compat/linux/common/linux_machdep.h>
     70 #include <compat/linux/common/linux_dirent.h>
     71 
     72 #include <compat/linux/linux_syscallargs.h>
     73 
     74 #ifndef alpha
     75 
     76 static void bsd_to_linux_stat __P((struct stat *, struct linux_stat64 *));
     77 static int linux_do_stat64 __P((struct lwp *, void *, register_t *, int));
     78 
     79 /*
     80  * Convert a NetBSD stat structure to a Linux stat structure.
     81  * Only the order of the fields and the padding in the structure
     82  * is different. linux_fakedev is a machine-dependent function
     83  * which optionally converts device driver major/minor numbers
     84  * (XXX horrible, but what can you do against code that compares
     85  * things against constant major device numbers? sigh)
     86  */
     87 static void
     88 bsd_to_linux_stat(bsp, lsp)
     89 	struct stat *bsp;
     90 	struct linux_stat64 *lsp;
     91 {
     92 	lsp->lst_dev     = linux_fakedev(bsp->st_dev, 0);
     93 	lsp->lst_ino     = bsp->st_ino;
     94 	lsp->lst_mode    = (linux_mode_t)bsp->st_mode;
     95 	if (bsp->st_nlink >= (1 << 15))
     96 		lsp->lst_nlink = (1 << 15) - 1;
     97 	else
     98 		lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
     99 	lsp->lst_uid     = bsp->st_uid;
    100 	lsp->lst_gid     = bsp->st_gid;
    101 	lsp->lst_rdev    = linux_fakedev(bsp->st_rdev, 1);
    102 	lsp->lst_size    = bsp->st_size;
    103 	lsp->lst_blksize = bsp->st_blksize;
    104 	lsp->lst_blocks  = bsp->st_blocks;
    105 	lsp->lst_atime   = bsp->st_atime;
    106 	lsp->lst_mtime   = bsp->st_mtime;
    107 	lsp->lst_ctime   = bsp->st_ctime;
    108 #ifdef LINUX_STAT64_HAS_NSEC
    109 	lsp->lst_atime_nsec   = bsp->st_atimensec;
    110 	lsp->lst_mtime_nsec   = bsp->st_mtimensec;
    111 	lsp->lst_ctime_nsec   = bsp->st_ctimensec;
    112 #endif
    113 #if LINUX_STAT64_HAS_BROKEN_ST_INO
    114 	lsp->__lst_ino   = (linux_ino_t) bsp->st_ino;
    115 #endif
    116 }
    117 
    118 /*
    119  * The stat functions below are plain sailing. stat and lstat are handled
    120  * by one function to avoid code duplication.
    121  */
    122 int
    123 linux_sys_fstat64(l, v, retval)
    124 	struct lwp *l;
    125 	void *v;
    126 	register_t *retval;
    127 {
    128 	struct linux_sys_fstat64_args /* {
    129 		syscallarg(int) fd;
    130 		syscallarg(struct linux_stat64 *) sp;
    131 	} */ *uap = v;
    132 	struct proc *p = l->l_proc;
    133 	struct sys___fstat13_args fsa;
    134 	struct linux_stat64 tmplst;
    135 	struct stat *st,tmpst;
    136 	caddr_t sg;
    137 	int error;
    138 
    139 	sg = stackgap_init(p, 0);
    140 
    141 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    142 
    143 	SCARG(&fsa, fd) = SCARG(uap, fd);
    144 	SCARG(&fsa, sb) = st;
    145 
    146 	if ((error = sys___fstat13(l, &fsa, retval)))
    147 		return error;
    148 
    149 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    150 		return error;
    151 
    152 	bsd_to_linux_stat(&tmpst, &tmplst);
    153 
    154 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    155 		return error;
    156 
    157 	return 0;
    158 }
    159 
    160 static int
    161 linux_do_stat64(l, v, retval, dolstat)
    162 	struct lwp *l;
    163 	void *v;
    164 	register_t *retval;
    165 	int dolstat;
    166 {
    167 	struct proc *p = l->l_proc;
    168 	struct sys___stat13_args sa;
    169 	struct linux_stat64 tmplst;
    170 	struct stat *st, tmpst;
    171 	caddr_t sg;
    172 	int error;
    173 	struct linux_sys_stat64_args *uap = v;
    174 
    175 	sg = stackgap_init(p, 0);
    176 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    177 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    178 
    179 	SCARG(&sa, ub) = st;
    180 	SCARG(&sa, path) = SCARG(uap, path);
    181 
    182 	if ((error = (dolstat ? sys___lstat13(l, &sa, retval) :
    183 				sys___stat13(l, &sa, retval))))
    184 		return error;
    185 
    186 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    187 		return error;
    188 
    189 	bsd_to_linux_stat(&tmpst, &tmplst);
    190 
    191 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    192 		return error;
    193 
    194 	return 0;
    195 }
    196 
    197 int
    198 linux_sys_stat64(l, v, retval)
    199 	struct lwp *l;
    200 	void *v;
    201 	register_t *retval;
    202 {
    203 	struct linux_sys_stat64_args /* {
    204 		syscallarg(const char *) path;
    205 		syscallarg(struct linux_stat64 *) sp;
    206 	} */ *uap = v;
    207 
    208 	return linux_do_stat64(l, uap, retval, 0);
    209 }
    210 
    211 int
    212 linux_sys_lstat64(l, v, retval)
    213 	struct lwp *l;
    214 	void *v;
    215 	register_t *retval;
    216 {
    217 	struct linux_sys_lstat64_args /* {
    218 		syscallarg(const char *) path;
    219 		syscallarg(struct linux_stat64 *) sp;
    220 	} */ *uap = v;
    221 
    222 	return linux_do_stat64(l, uap, retval, 1);
    223 }
    224 
    225 int
    226 linux_sys_truncate64(l, v, retval)
    227 	struct lwp *l;
    228 	void *v;
    229 	register_t *retval;
    230 {
    231 	struct linux_sys_truncate64_args /* {
    232 		syscallarg(const char *) path;
    233 		syscallarg(off_t) length;
    234 	} */ *uap = v;
    235 	struct sys_truncate_args ta;
    236 	struct proc *p = l->l_proc;
    237 	caddr_t sg = stackgap_init(p, 0);
    238 
    239 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    240 
    241 	/* Linux doesn't have the 'pad' pseudo-parameter */
    242 	SCARG(&ta, path) = SCARG(uap, path);
    243 	SCARG(&ta, pad) = 0;
    244 	SCARG(&ta, length) = SCARG(uap, length);
    245 
    246 	return sys_truncate(l, &ta, retval);
    247 }
    248 
    249 int
    250 linux_sys_ftruncate64(l, v, retval)
    251 	struct lwp *l;
    252 	void *v;
    253 	register_t *retval;
    254 {
    255 	struct linux_sys_ftruncate64_args /* {
    256 		syscallarg(unsigned int) fd;
    257 		syscallarg(off_t) length;
    258 	} */ *uap = v;
    259 	struct sys_ftruncate_args ta;
    260 
    261 	/* Linux doesn't have the 'pad' pseudo-parameter */
    262 	SCARG(&ta, fd) = SCARG(uap, fd);
    263 	SCARG(&ta, pad) = 0;
    264 	SCARG(&ta, length) = SCARG(uap, length);
    265 
    266 	return sys_ftruncate(l, &ta, retval);
    267 }
    268 
    269 #if !defined(__m68k__) && !defined(__amd64__)
    270 static void bsd_to_linux_flock64 __P((struct linux_flock64 *,
    271     const struct flock *));
    272 static void linux_to_bsd_flock64 __P((struct flock *,
    273     const struct linux_flock64 *));
    274 
    275 static void
    276 bsd_to_linux_flock64(lfp, bfp)
    277 	struct linux_flock64 *lfp;
    278 	const struct flock *bfp;
    279 {
    280 
    281 	lfp->l_start = bfp->l_start;
    282 	lfp->l_len = bfp->l_len;
    283 	lfp->l_pid = bfp->l_pid;
    284 	lfp->l_whence = bfp->l_whence;
    285 	switch (bfp->l_type) {
    286 	case F_RDLCK:
    287 		lfp->l_type = LINUX_F_RDLCK;
    288 		break;
    289 	case F_UNLCK:
    290 		lfp->l_type = LINUX_F_UNLCK;
    291 		break;
    292 	case F_WRLCK:
    293 		lfp->l_type = LINUX_F_WRLCK;
    294 		break;
    295 	}
    296 }
    297 
    298 static void
    299 linux_to_bsd_flock64(bfp, lfp)
    300 	struct flock *bfp;
    301 	const struct linux_flock64 *lfp;
    302 {
    303 
    304 	bfp->l_start = lfp->l_start;
    305 	bfp->l_len = lfp->l_len;
    306 	bfp->l_pid = lfp->l_pid;
    307 	bfp->l_whence = lfp->l_whence;
    308 	switch (lfp->l_type) {
    309 	case LINUX_F_RDLCK:
    310 		bfp->l_type = F_RDLCK;
    311 		break;
    312 	case LINUX_F_UNLCK:
    313 		bfp->l_type = F_UNLCK;
    314 		break;
    315 	case LINUX_F_WRLCK:
    316 		bfp->l_type = F_WRLCK;
    317 		break;
    318 	}
    319 }
    320 
    321 int
    322 linux_sys_fcntl64(l, v, retval)
    323 	struct lwp *l;
    324 	void *v;
    325 	register_t *retval;
    326 {
    327 	struct linux_sys_fcntl64_args /* {
    328 		syscallarg(int) fd;
    329 		syscallarg(int) cmd;
    330 		syscallarg(void *) arg;
    331 	} */ *uap = v;
    332 	struct proc *p = l->l_proc;
    333 	struct sys_fcntl_args fca;
    334 	struct linux_flock64 lfl;
    335 	struct flock bfl, *bfp;
    336 	int error;
    337 	caddr_t sg;
    338 	void *arg = SCARG(uap, arg);
    339 	int cmd = SCARG(uap, cmd);
    340 	int fd = SCARG(uap, fd);
    341 
    342 	switch (cmd) {
    343 	case LINUX_F_GETLK64:
    344 		sg = stackgap_init(p, 0);
    345 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    346 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    347 			return error;
    348 		linux_to_bsd_flock64(&bfl, &lfl);
    349 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    350 			return error;
    351 		SCARG(&fca, fd) = fd;
    352 		SCARG(&fca, cmd) = F_GETLK;
    353 		SCARG(&fca, arg) = bfp;
    354 		if ((error = sys_fcntl(l, &fca, retval)) != 0)
    355 			return error;
    356 		if ((error = copyin(bfp, &bfl, sizeof bfl)) != 0)
    357 			return error;
    358 		bsd_to_linux_flock64(&lfl, &bfl);
    359 		return copyout(&lfl, arg, sizeof lfl);
    360 	case LINUX_F_SETLK64:
    361 	case LINUX_F_SETLKW64:
    362 		cmd = (cmd == LINUX_F_SETLK64 ? F_SETLK : F_SETLKW);
    363 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    364 			return error;
    365 		linux_to_bsd_flock64(&bfl, &lfl);
    366 		sg = stackgap_init(p, 0);
    367 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    368 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    369 			return error;
    370 		SCARG(&fca, fd) = fd;
    371 		SCARG(&fca, cmd) = cmd;
    372 		SCARG(&fca, arg) = bfp;
    373 		return sys_fcntl(l, &fca, retval);
    374 	default:
    375 		return linux_sys_fcntl(l, v, retval);
    376 	}
    377 }
    378 #endif /* !m68k && !amd64 */
    379 
    380 #endif /* !alpha */
    381 
    382 /*
    383  * Linux 'readdir' call. This code is mostly taken from the
    384  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    385  * an attempt has been made to keep it a little cleaner.
    386  *
    387  * The d_off field contains the offset of the next valid entry,
    388  * unless the older Linux getdents(2), which used to have it set
    389  * to the offset of the entry itself. This function also doesn't
    390  * need to deal with the old count == 1 glibc problem.
    391  *
    392  * Read in BSD-style entries, convert them, and copy them out.
    393  *
    394  * Note that this doesn't handle union-mounted filesystems.
    395  */
    396 int
    397 linux_sys_getdents64(l, v, retval)
    398 	struct lwp *l;
    399 	void *v;
    400 	register_t *retval;
    401 {
    402 	struct linux_sys_getdents_args /* {
    403 		syscallarg(int) fd;
    404 		syscallarg(struct linux_dirent64 *) dent;
    405 		syscallarg(unsigned int) count;
    406 	} */ *uap = v;
    407 	struct proc *p = l->l_proc;
    408 	struct dirent *bdp;
    409 	struct vnode *vp;
    410 	caddr_t	inp, buf;		/* BSD-format */
    411 	int len, reclen;		/* BSD-format */
    412 	caddr_t outp;			/* Linux-format */
    413 	int resid, linux_reclen = 0;	/* Linux-format */
    414 	struct file *fp;
    415 	struct uio auio;
    416 	struct iovec aiov;
    417 	struct linux_dirent64 idb;
    418 	off_t off;		/* true file offset */
    419 	int buflen, error, eofflag, nbytes;
    420 	struct vattr va;
    421 	off_t *cookiebuf = NULL, *cookie;
    422 	int ncookies;
    423 
    424 	/* getvnode() will use the descriptor for us */
    425 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    426 		return (error);
    427 
    428 	if ((fp->f_flag & FREAD) == 0) {
    429 		error = EBADF;
    430 		goto out1;
    431 	}
    432 
    433 	vp = (struct vnode *)fp->f_data;
    434 	if (vp->v_type != VDIR) {
    435 		error = EINVAL;
    436 		goto out1;
    437 	}
    438 
    439 	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
    440 		goto out1;
    441 
    442 	nbytes = SCARG(uap, count);
    443 	buflen = min(MAXBSIZE, nbytes);
    444 	if (buflen < va.va_blocksize)
    445 		buflen = va.va_blocksize;
    446 	buf = malloc(buflen, M_TEMP, M_WAITOK);
    447 
    448 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    449 	off = fp->f_offset;
    450 again:
    451 	aiov.iov_base = buf;
    452 	aiov.iov_len = buflen;
    453 	auio.uio_iov = &aiov;
    454 	auio.uio_iovcnt = 1;
    455 	auio.uio_rw = UIO_READ;
    456 	auio.uio_segflg = UIO_SYSSPACE;
    457 	auio.uio_procp = NULL;
    458 	auio.uio_resid = buflen;
    459 	auio.uio_offset = off;
    460 	/*
    461          * First we read into the malloc'ed buffer, then
    462          * we massage it into user space, one record at a time.
    463          */
    464 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    465 	    &ncookies);
    466 	if (error)
    467 		goto out;
    468 
    469 	inp = buf;
    470 	outp = (caddr_t)SCARG(uap, dent);
    471 	resid = nbytes;
    472 	if ((len = buflen - auio.uio_resid) == 0)
    473 		goto eof;
    474 
    475 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    476 		bdp = (struct dirent *)inp;
    477 		reclen = bdp->d_reclen;
    478 		if (reclen & 3)
    479 			panic("linux_readdir");
    480 		if (bdp->d_fileno == 0) {
    481 			inp += reclen;	/* it is a hole; squish it out */
    482 			if (cookie)
    483 				off = *cookie++;
    484 			else
    485 				off += reclen;
    486 			continue;
    487 		}
    488 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    489 		if (reclen > len || resid < linux_reclen) {
    490 			/* entry too big for buffer, so just stop */
    491 			outp++;
    492 			break;
    493 		}
    494 		if (cookie)
    495 			off = *cookie++;	/* each entry points to next */
    496 		else
    497 			off += reclen;
    498 		/*
    499 		 * Massage in place to make a Linux-shaped dirent (otherwise
    500 		 * we have to worry about touching user memory outside of
    501 		 * the copyout() call).
    502 		 */
    503 		idb.d_ino = bdp->d_fileno;
    504 		idb.d_type = bdp->d_type;
    505 		idb.d_off = off;
    506 		idb.d_reclen = (u_short)linux_reclen;
    507 		strcpy(idb.d_name, bdp->d_name);
    508 		if ((error = copyout((caddr_t)&idb, outp, linux_reclen)))
    509 			goto out;
    510 		/* advance past this real entry */
    511 		inp += reclen;
    512 		/* advance output past Linux-shaped entry */
    513 		outp += linux_reclen;
    514 		resid -= linux_reclen;
    515 	}
    516 
    517 	/* if we squished out the whole block, try again */
    518 	if (outp == (caddr_t)SCARG(uap, dent))
    519 		goto again;
    520 	fp->f_offset = off;	/* update the vnode offset */
    521 
    522 eof:
    523 	*retval = nbytes - resid;
    524 out:
    525 	VOP_UNLOCK(vp, 0);
    526 	if (cookiebuf)
    527 		free(cookiebuf, M_TEMP);
    528 	free(buf, M_TEMP);
    529 out1:
    530 	FILE_UNUSE(fp, p);
    531 	return error;
    532 }
    533