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vfs_syscalls_43.c revision 1.20
      1 /*	$NetBSD: vfs_syscalls_43.c,v 1.20 2001/11/13 02:08:05 lukem 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. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Berkeley and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)vfs_syscalls.c	8.28 (Berkeley) 12/10/94
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: vfs_syscalls_43.c,v 1.20 2001/11/13 02:08:05 lukem Exp $");
     45 
     46 #if defined(_KERNEL_OPT)
     47 #include "fs_union.h"
     48 #endif
     49 
     50 #include <sys/param.h>
     51 #include <sys/systm.h>
     52 #include <sys/filedesc.h>
     53 #include <sys/kernel.h>
     54 #include <sys/proc.h>
     55 #include <sys/file.h>
     56 #include <sys/vnode.h>
     57 #include <sys/namei.h>
     58 #include <sys/dirent.h>
     59 #include <sys/socket.h>
     60 #include <sys/socketvar.h>
     61 #include <sys/stat.h>
     62 #include <sys/ioctl.h>
     63 #include <sys/fcntl.h>
     64 #include <sys/malloc.h>
     65 #include <sys/syslog.h>
     66 #include <sys/unistd.h>
     67 #include <sys/resourcevar.h>
     68 
     69 #include <sys/mount.h>
     70 #include <sys/syscallargs.h>
     71 
     72 static void cvtstat __P((struct stat *, struct stat43 *));
     73 
     74 /*
     75  * Convert from an old to a new stat structure.
     76  */
     77 static void
     78 cvtstat(st, ost)
     79 	struct stat *st;
     80 	struct stat43 *ost;
     81 {
     82 
     83 	ost->st_dev = st->st_dev;
     84 	ost->st_ino = st->st_ino;
     85 	ost->st_mode = st->st_mode & 0xffff;
     86 	ost->st_nlink = st->st_nlink;
     87 	ost->st_uid = st->st_uid;
     88 	ost->st_gid = st->st_gid;
     89 	ost->st_rdev = st->st_rdev;
     90 	if (st->st_size < (quad_t)1 << 32)
     91 		ost->st_size = st->st_size;
     92 	else
     93 		ost->st_size = -2;
     94 	ost->st_atime = st->st_atime;
     95 	ost->st_mtime = st->st_mtime;
     96 	ost->st_ctime = st->st_ctime;
     97 	ost->st_blksize = st->st_blksize;
     98 	ost->st_blocks = st->st_blocks;
     99 	ost->st_flags = st->st_flags;
    100 	ost->st_gen = st->st_gen;
    101 }
    102 
    103 /*
    104  * Get file status; this version follows links.
    105  */
    106 /* ARGSUSED */
    107 int
    108 compat_43_sys_stat(p, v, retval)
    109 	struct proc *p;
    110 	void *v;
    111 	register_t *retval;
    112 {
    113 	struct compat_43_sys_stat_args /* {
    114 		syscallarg(char *) path;
    115 		syscallarg(struct stat43 *) ub;
    116 	} */ *uap = v;
    117 	struct stat sb;
    118 	struct stat43 osb;
    119 	int error;
    120 	struct nameidata nd;
    121 
    122 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
    123 	    SCARG(uap, path), p);
    124 	if ((error = namei(&nd)) != 0)
    125 		return (error);
    126 	error = vn_stat(nd.ni_vp, &sb, p);
    127 	vput(nd.ni_vp);
    128 	if (error)
    129 		return (error);
    130 	cvtstat(&sb, &osb);
    131 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    132 	return (error);
    133 }
    134 
    135 /*
    136  * Get file status; this version does not follow links.
    137  */
    138 /* ARGSUSED */
    139 int
    140 compat_43_sys_lstat(p, v, retval)
    141 	struct proc *p;
    142 	void *v;
    143 	register_t *retval;
    144 {
    145 	struct compat_43_sys_lstat_args /* {
    146 		syscallarg(char *) path;
    147 		syscallarg(struct ostat *) ub;
    148 	} */ *uap = v;
    149 	struct vnode *vp, *dvp;
    150 	struct stat sb, sb1;
    151 	struct stat43 osb;
    152 	int error;
    153 	struct nameidata nd;
    154 	int ndflags;
    155 
    156 	ndflags = NOFOLLOW | LOCKLEAF | LOCKPARENT;
    157 again:
    158 	NDINIT(&nd, LOOKUP, ndflags, UIO_USERSPACE, SCARG(uap, path), p);
    159 	if ((error = namei(&nd))) {
    160 		if (error == EISDIR && (ndflags & LOCKPARENT) != 0) {
    161 			/*
    162 			 * Should only happen on '/'. Retry without LOCKPARENT;
    163 			 * this is safe since the vnode won't be a VLNK.
    164 			 */
    165 			ndflags &= ~LOCKPARENT;
    166 			goto again;
    167 		}
    168 		return (error);
    169 	}
    170 	/*
    171 	 * For symbolic links, always return the attributes of its
    172 	 * containing directory, except for mode, size, and links.
    173 	 */
    174 	vp = nd.ni_vp;
    175 	dvp = nd.ni_dvp;
    176 	if (vp->v_type != VLNK) {
    177 		if ((ndflags & LOCKPARENT) != 0) {
    178 			if (dvp == vp)
    179 				vrele(dvp);
    180 			else
    181 				vput(dvp);
    182 		}
    183 		error = vn_stat(vp, &sb, p);
    184 		vput(vp);
    185 		if (error)
    186 			return (error);
    187 	} else {
    188 		error = vn_stat(dvp, &sb, p);
    189 		vput(dvp);
    190 		if (error) {
    191 			vput(vp);
    192 			return (error);
    193 		}
    194 		error = vn_stat(vp, &sb1, p);
    195 		vput(vp);
    196 		if (error)
    197 			return (error);
    198 		sb.st_mode &= ~S_IFDIR;
    199 		sb.st_mode |= S_IFLNK;
    200 		sb.st_nlink = sb1.st_nlink;
    201 		sb.st_size = sb1.st_size;
    202 		sb.st_blocks = sb1.st_blocks;
    203 	}
    204 	cvtstat(&sb, &osb);
    205 	error = copyout((caddr_t)&osb, (caddr_t)SCARG(uap, ub), sizeof (osb));
    206 	return (error);
    207 }
    208 
    209 /*
    210  * Return status information about a file descriptor.
    211  */
    212 /* ARGSUSED */
    213 int
    214 compat_43_sys_fstat(p, v, retval)
    215 	struct proc *p;
    216 	void *v;
    217 	register_t *retval;
    218 {
    219 	struct compat_43_sys_fstat_args /* {
    220 		syscallarg(int) fd;
    221 		syscallarg(struct stat43 *) sb;
    222 	} */ *uap = v;
    223 	int fd = SCARG(uap, fd);
    224 	struct filedesc *fdp = p->p_fd;
    225 	struct file *fp;
    226 	struct stat ub;
    227 	struct stat43 oub;
    228 	int error;
    229 
    230 	if ((fp = fd_getfile(fdp, fd)) == NULL)
    231 		return (EBADF);
    232 
    233 	FILE_USE(fp);
    234 	error = (*fp->f_ops->fo_stat)(fp, &ub, p);
    235 	FILE_UNUSE(fp, p);
    236 
    237 	if (error == 0) {
    238 		cvtstat(&ub, &oub);
    239 		error = copyout((caddr_t)&oub, (caddr_t)SCARG(uap, sb),
    240 		    sizeof (oub));
    241 	}
    242 
    243 
    244 	return (error);
    245 }
    246 
    247 
    248 /*
    249  * Truncate a file given a file descriptor.
    250  */
    251 /* ARGSUSED */
    252 int
    253 compat_43_sys_ftruncate(p, v, retval)
    254 	struct proc *p;
    255 	void *v;
    256 	register_t *retval;
    257 {
    258 	struct compat_43_sys_ftruncate_args /* {
    259 		syscallarg(int) fd;
    260 		syscallarg(long) length;
    261 	} */ *uap = v;
    262 	struct sys_ftruncate_args /* {
    263 		syscallarg(int) fd;
    264 		syscallarg(int) pad;
    265 		syscallarg(off_t) length;
    266 	} */ nuap;
    267 
    268 	SCARG(&nuap, fd) = SCARG(uap, fd);
    269 	SCARG(&nuap, length) = SCARG(uap, length);
    270 	return (sys_ftruncate(p, &nuap, retval));
    271 }
    272 
    273 /*
    274  * Truncate a file given its path name.
    275  */
    276 /* ARGSUSED */
    277 int
    278 compat_43_sys_truncate(p, v, retval)
    279 	struct proc *p;
    280 	void *v;
    281 	register_t *retval;
    282 {
    283 	struct compat_43_sys_truncate_args /* {
    284 		syscallarg(char *) path;
    285 		syscallarg(long) length;
    286 	} */ *uap = v;
    287 	struct sys_truncate_args /* {
    288 		syscallarg(char *) path;
    289 		syscallarg(int) pad;
    290 		syscallarg(off_t) length;
    291 	} */ nuap;
    292 
    293 	SCARG(&nuap, path) = SCARG(uap, path);
    294 	SCARG(&nuap, length) = SCARG(uap, length);
    295 	return (sys_truncate(p, &nuap, retval));
    296 }
    297 
    298 
    299 /*
    300  * Reposition read/write file offset.
    301  */
    302 int
    303 compat_43_sys_lseek(p, v, retval)
    304 	struct proc *p;
    305 	void *v;
    306 	register_t *retval;
    307 {
    308 	struct compat_43_sys_lseek_args /* {
    309 		syscallarg(int) fd;
    310 		syscallarg(long) offset;
    311 		syscallarg(int) whence;
    312 	} */ *uap = v;
    313 	struct sys_lseek_args /* {
    314 		syscallarg(int) fd;
    315 		syscallarg(int) pad;
    316 		syscallarg(off_t) offset;
    317 		syscallarg(int) whence;
    318 	} */ nuap;
    319 	off_t qret;
    320 	int error;
    321 
    322 	SCARG(&nuap, fd) = SCARG(uap, fd);
    323 	SCARG(&nuap, offset) = SCARG(uap, offset);
    324 	SCARG(&nuap, whence) = SCARG(uap, whence);
    325 	error = sys_lseek(p, &nuap, (register_t *)&qret);
    326 	*(long *)retval = qret;
    327 	return (error);
    328 }
    329 
    330 
    331 /*
    332  * Create a file.
    333  */
    334 int
    335 compat_43_sys_creat(p, v, retval)
    336 	struct proc *p;
    337 	void *v;
    338 	register_t *retval;
    339 {
    340 	struct compat_43_sys_creat_args /* {
    341 		syscallarg(char *) path;
    342 		syscallarg(int) mode;
    343 	} */ *uap = v;
    344 	struct sys_open_args /* {
    345 		syscallarg(char *) path;
    346 		syscallarg(int) flags;
    347 		syscallarg(int) mode;
    348 	} */ nuap;
    349 
    350 	SCARG(&nuap, path) = SCARG(uap, path);
    351 	SCARG(&nuap, mode) = SCARG(uap, mode);
    352 	SCARG(&nuap, flags) = O_WRONLY | O_CREAT | O_TRUNC;
    353 	return (sys_open(p, &nuap, retval));
    354 }
    355 
    356 /*ARGSUSED*/
    357 int
    358 compat_43_sys_quota(p, v, retval)
    359 	struct proc *p;
    360 	void *v;
    361 	register_t *retval;
    362 {
    363 
    364 	return (ENOSYS);
    365 }
    366 
    367 
    368 /*
    369  * Read a block of directory entries in a file system independent format.
    370  */
    371 int
    372 compat_43_sys_getdirentries(p, v, retval)
    373 	struct proc *p;
    374 	void *v;
    375 	register_t *retval;
    376 {
    377 	struct compat_43_sys_getdirentries_args /* {
    378 		syscallarg(int) fd;
    379 		syscallarg(char *) buf;
    380 		syscallarg(u_int) count;
    381 		syscallarg(long *) basep;
    382 	} */ *uap = v;
    383 	struct vnode *vp;
    384 	struct file *fp;
    385 	struct uio auio, kuio;
    386 	struct iovec aiov, kiov;
    387 	struct dirent *dp, *edp;
    388 	caddr_t dirbuf;
    389 	int error, eofflag, readcnt;
    390 	long loff;
    391 
    392 	/* getvnode() will use the descriptor for us */
    393 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    394 		return (error);
    395 	if ((fp->f_flag & FREAD) == 0) {
    396 		error = EBADF;
    397 		goto out;
    398 	}
    399 	vp = (struct vnode *)fp->f_data;
    400 unionread:
    401 	if (vp->v_type != VDIR) {
    402 		error = EINVAL;
    403 		goto out;
    404 	}
    405 	aiov.iov_base = SCARG(uap, buf);
    406 	aiov.iov_len = SCARG(uap, count);
    407 	auio.uio_iov = &aiov;
    408 	auio.uio_iovcnt = 1;
    409 	auio.uio_rw = UIO_READ;
    410 	auio.uio_segflg = UIO_USERSPACE;
    411 	auio.uio_procp = p;
    412 	auio.uio_resid = SCARG(uap, count);
    413 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    414 	loff = auio.uio_offset = fp->f_offset;
    415 #	if (BYTE_ORDER != LITTLE_ENDIAN)
    416 		if (vp->v_mount->mnt_maxsymlinklen <= 0) {
    417 			error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag,
    418 			    (off_t **)0, (int *)0);
    419 			fp->f_offset = auio.uio_offset;
    420 		} else
    421 #	endif
    422 	{
    423 		kuio = auio;
    424 		kuio.uio_iov = &kiov;
    425 		kuio.uio_segflg = UIO_SYSSPACE;
    426 		kiov.iov_len = SCARG(uap, count);
    427 		MALLOC(dirbuf, caddr_t, SCARG(uap, count), M_TEMP, M_WAITOK);
    428 		kiov.iov_base = dirbuf;
    429 		error = VOP_READDIR(vp, &kuio, fp->f_cred, &eofflag,
    430 			    (off_t **)0, (int *)0);
    431 		fp->f_offset = kuio.uio_offset;
    432 		if (error == 0) {
    433 			readcnt = SCARG(uap, count) - kuio.uio_resid;
    434 			edp = (struct dirent *)&dirbuf[readcnt];
    435 			for (dp = (struct dirent *)dirbuf; dp < edp; ) {
    436 #				if (BYTE_ORDER == LITTLE_ENDIAN)
    437 					/*
    438 					 * The expected low byte of
    439 					 * dp->d_namlen is our dp->d_type.
    440 					 * The high MBZ byte of dp->d_namlen
    441 					 * is our dp->d_namlen.
    442 					 */
    443 					dp->d_type = dp->d_namlen;
    444 					dp->d_namlen = 0;
    445 #				else
    446 					/*
    447 					 * The dp->d_type is the high byte
    448 					 * of the expected dp->d_namlen,
    449 					 * so must be zero'ed.
    450 					 */
    451 					dp->d_type = 0;
    452 #				endif
    453 				if (dp->d_reclen > 0) {
    454 					dp = (struct dirent *)
    455 					    ((char *)dp + dp->d_reclen);
    456 				} else {
    457 					error = EIO;
    458 					break;
    459 				}
    460 			}
    461 			if (dp >= edp)
    462 				error = uiomove(dirbuf, readcnt, &auio);
    463 		}
    464 		FREE(dirbuf, M_TEMP);
    465 	}
    466 	VOP_UNLOCK(vp, 0);
    467 	if (error)
    468 		goto out;
    469 
    470 #ifdef UNION
    471 {
    472 	extern int (**union_vnodeop_p) __P((void *));
    473 	extern struct vnode *union_dircache __P((struct vnode *));
    474 
    475 	if ((SCARG(uap, count) == auio.uio_resid) &&
    476 	    (vp->v_op == union_vnodeop_p)) {
    477 		struct vnode *lvp;
    478 
    479 		lvp = union_dircache(vp);
    480 		if (lvp != NULLVP) {
    481 			struct vattr va;
    482 
    483 			/*
    484 			 * If the directory is opaque,
    485 			 * then don't show lower entries
    486 			 */
    487 			error = VOP_GETATTR(vp, &va, fp->f_cred, p);
    488 			if (va.va_flags & OPAQUE) {
    489 				vput(lvp);
    490 				lvp = NULL;
    491 			}
    492 		}
    493 
    494 		if (lvp != NULLVP) {
    495 			error = VOP_OPEN(lvp, FREAD, fp->f_cred, p);
    496 			VOP_UNLOCK(lvp, 0);
    497 
    498 			if (error) {
    499 				vrele(lvp);
    500 				goto out;
    501 			}
    502 			fp->f_data = (caddr_t) lvp;
    503 			fp->f_offset = 0;
    504 			error = vn_close(vp, FREAD, fp->f_cred, p);
    505 			if (error)
    506 				goto out;
    507 			vp = lvp;
    508 			goto unionread;
    509 		}
    510 	}
    511 }
    512 #endif /* UNION */
    513 
    514 	if ((SCARG(uap, count) == auio.uio_resid) &&
    515 	    (vp->v_flag & VROOT) &&
    516 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
    517 		struct vnode *tvp = vp;
    518 		vp = vp->v_mount->mnt_vnodecovered;
    519 		VREF(vp);
    520 		fp->f_data = (caddr_t) vp;
    521 		fp->f_offset = 0;
    522 		vrele(tvp);
    523 		goto unionread;
    524 	}
    525 	error = copyout((caddr_t)&loff, (caddr_t)SCARG(uap, basep),
    526 	    sizeof(long));
    527 	*retval = SCARG(uap, count) - auio.uio_resid;
    528  out:
    529 	FILE_UNUSE(fp, p);
    530 	return (error);
    531 }
    532