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vfs_syscalls_12.c revision 1.32
      1 /*	$NetBSD: vfs_syscalls_12.c,v 1.32 2017/01/13 20:58:59 christos 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 1.32 2017/01/13 20:58:59 christos Exp $");
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/namei.h>
     45 #include <sys/filedesc.h>
     46 #include <sys/kernel.h>
     47 #include <sys/file.h>
     48 #include <sys/stat.h>
     49 #include <sys/socketvar.h>
     50 #include <sys/vnode.h>
     51 #include <sys/proc.h>
     52 #include <sys/uio.h>
     53 #include <sys/dirent.h>
     54 #include <sys/vfs_syscalls.h>
     55 
     56 #include <sys/syscallargs.h>
     57 
     58 #include <compat/sys/stat.h>
     59 #include <compat/sys/dirent.h>
     60 
     61 /*
     62  * Convert from a new to an old stat structure.
     63  */
     64 void
     65 compat_12_stat_conv(const struct stat *st, struct stat12 *ost)
     66 {
     67 
     68 	ost->st_dev = st->st_dev;
     69 	ost->st_ino = st->st_ino;
     70 	ost->st_mode = st->st_mode & 0xffff;
     71 	if (st->st_nlink >= (1 << 15))
     72 		ost->st_nlink = (1 << 15) - 1;
     73 	else
     74 		ost->st_nlink = st->st_nlink;
     75 	ost->st_uid = st->st_uid;
     76 	ost->st_gid = st->st_gid;
     77 	ost->st_rdev = st->st_rdev;
     78 	timespec_to_timespec50(&st->st_atimespec, &ost->st_atimespec);
     79 	timespec_to_timespec50(&st->st_mtimespec, &ost->st_mtimespec);
     80 	timespec_to_timespec50(&st->st_ctimespec, &ost->st_ctimespec);
     81 	ost->st_size = st->st_size;
     82 	ost->st_blocks = st->st_blocks;
     83 	ost->st_blksize = st->st_blksize;
     84 	ost->st_flags = st->st_flags;
     85 	ost->st_gen = st->st_gen;
     86 }
     87 
     88 /*
     89  * Read a block of directory entries in a file system independent format.
     90  */
     91 int
     92 compat_12_sys_getdirentries(struct lwp *l, const struct compat_12_sys_getdirentries_args *uap, register_t *retval)
     93 {
     94 	/* {
     95 		syscallarg(int) fd;
     96 		syscallarg(char *) buf;
     97 		syscallarg(u_int) count;
     98 		syscallarg(long *) basep;
     99 	} */
    100 	struct dirent *bdp;
    101 	struct vnode *vp;
    102 	char *inp, *tbuf;		/* Current-format */
    103 	int len, reclen;		/* Current-format */
    104 	char *outp;			/* Dirent12-format */
    105 	int resid, old_reclen = 0;	/* Dirent12-format */
    106 	struct file *fp;
    107 	struct uio auio;
    108 	struct iovec aiov;
    109 	struct dirent12 idb;
    110 	off_t off;		/* true file offset */
    111 	int buflen, error, eofflag, nbytes;
    112 	struct vattr va;
    113 	off_t *cookiebuf = NULL, *cookie;
    114 	int ncookies;
    115 	long loff;
    116 
    117 	/* fd_getvnode() will use the descriptor for us */
    118 	if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0)
    119 		return (error);
    120 
    121 	if ((fp->f_flag & FREAD) == 0) {
    122 		error = EBADF;
    123 		goto out1;
    124 	}
    125 
    126 	vp = (struct vnode *)fp->f_vnode;
    127 	if (vp->v_type != VDIR) {
    128 		error = ENOTDIR;
    129 		goto out1;
    130 	}
    131 
    132 	vn_lock(vp, LK_SHARED | LK_RETRY);
    133 	error = VOP_GETATTR(vp, &va, l->l_cred);
    134 	VOP_UNLOCK(vp);
    135 	if (error)
    136 		goto out1;
    137 
    138 	loff = fp->f_offset;
    139 	nbytes = SCARG(uap, count);
    140 	buflen = min(MAXBSIZE, nbytes);
    141 	if (buflen < va.va_blocksize)
    142 		buflen = va.va_blocksize;
    143 	tbuf = malloc(buflen, M_TEMP, M_WAITOK);
    144 
    145 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    146 	off = fp->f_offset;
    147 again:
    148 	aiov.iov_base = tbuf;
    149 	aiov.iov_len = buflen;
    150 	auio.uio_iov = &aiov;
    151 	auio.uio_iovcnt = 1;
    152 	auio.uio_rw = UIO_READ;
    153 	auio.uio_resid = buflen;
    154 	auio.uio_offset = off;
    155 	UIO_SETUP_SYSSPACE(&auio);
    156 	/*
    157          * First we read into the malloc'ed buffer, then
    158          * we massage it into user space, one record at a time.
    159          */
    160 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    161 	    &ncookies);
    162 	if (error)
    163 		goto out;
    164 
    165 	inp = tbuf;
    166 	outp = SCARG(uap, buf);
    167 	resid = nbytes;
    168 	if ((len = buflen - auio.uio_resid) == 0)
    169 		goto eof;
    170 
    171 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    172 		bdp = (struct dirent *)inp;
    173 		reclen = bdp->d_reclen;
    174 		if (reclen & 3)
    175 			panic(__func__);
    176 		if (bdp->d_fileno == 0) {
    177 			inp += reclen;	/* it is a hole; squish it out */
    178 			if (cookie)
    179 				off = *cookie++;
    180 			else
    181 				off += reclen;
    182 			continue;
    183 		}
    184 		old_reclen = _DIRENT_RECLEN(&idb, bdp->d_namlen);
    185 		if (reclen > len || resid < old_reclen) {
    186 			/* entry too big for buffer, so just stop */
    187 			outp++;
    188 			break;
    189 		}
    190 		/*
    191 		 * Massage in place to make a Dirent12-shaped dirent (otherwise
    192 		 * we have to worry about touching user memory outside of
    193 		 * the copyout() call).
    194 		 */
    195 		idb.d_fileno = (uint32_t)bdp->d_fileno;
    196 		idb.d_reclen = (uint16_t)old_reclen;
    197 		idb.d_type = (uint8_t)bdp->d_type;
    198 		idb.d_namlen = (uint8_t)bdp->d_namlen;
    199 		memcpy(idb.d_name, bdp->d_name, MIN(sizeof(idb.d_name),
    200 		    idb.d_namlen));
    201 		if ((error = copyout(&idb, outp, old_reclen)))
    202 			goto out;
    203 		/* advance past this real entry */
    204 		inp += reclen;
    205 		if (cookie)
    206 			off = *cookie++; /* each entry points to itself */
    207 		else
    208 			off += reclen;
    209 		/* advance output past Dirent12-shaped entry */
    210 		outp += old_reclen;
    211 		resid -= old_reclen;
    212 	}
    213 
    214 	/* if we squished out the whole block, try again */
    215 	if (outp == SCARG(uap, buf)) {
    216 		if (cookiebuf)
    217 			free(cookiebuf, M_TEMP);
    218 		cookiebuf = NULL;
    219 		goto again;
    220 	}
    221 	fp->f_offset = off;	/* update the vnode offset */
    222 
    223 eof:
    224 	*retval = nbytes - resid;
    225 out:
    226 	VOP_UNLOCK(vp);
    227 	if (cookiebuf)
    228 		free(cookiebuf, M_TEMP);
    229 	free(tbuf, M_TEMP);
    230 out1:
    231 	fd_putfile(SCARG(uap, fd));
    232 	if (error)
    233 		return error;
    234 	return copyout(&loff, SCARG(uap, basep), sizeof(long));
    235 }
    236 
    237 /*
    238  * Get file status; this version follows links.
    239  */
    240 /* ARGSUSED */
    241 int
    242 compat_12_sys_stat(struct lwp *l, const struct compat_12_sys_stat_args *uap, register_t *retval)
    243 {
    244 	/* {
    245 		syscallarg(const char *) path;
    246 		syscallarg(struct stat12 *) ub;
    247 	} */
    248 	struct stat sb;
    249 	struct stat12 osb;
    250 	int error;
    251 
    252 	error = do_sys_stat(SCARG(uap, path), FOLLOW, &sb);
    253 	if (error)
    254 		return (error);
    255 	compat_12_stat_conv(&sb, &osb);
    256 	error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
    257 	return (error);
    258 }
    259 
    260 
    261 /*
    262  * Get file status; this version does not follow links.
    263  */
    264 /* ARGSUSED */
    265 int
    266 compat_12_sys_lstat(struct lwp *l, const struct compat_12_sys_lstat_args *uap, register_t *retval)
    267 {
    268 	/* {
    269 		syscallarg(const char *) path;
    270 		syscallarg(struct stat12 *) ub;
    271 	} */
    272 	struct stat sb;
    273 	struct stat12 osb;
    274 	int error;
    275 
    276 	error = do_sys_stat(SCARG(uap, path), NOFOLLOW, &sb);
    277 	if (error)
    278 		return (error);
    279 	compat_12_stat_conv(&sb, &osb);
    280 	error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
    281 	return (error);
    282 }
    283 
    284 /*
    285  * Return status information about a file descriptor.
    286  */
    287 /* ARGSUSED */
    288 int
    289 compat_12_sys_fstat(struct lwp *l, const struct compat_12_sys_fstat_args *uap, register_t *retval)
    290 {
    291 	/* {
    292 		syscallarg(int) fd;
    293 		syscallarg(struct stat12 *) sb;
    294 	} */
    295 	struct stat ub;
    296 	struct stat12 oub;
    297 	int error;
    298 
    299 	error = do_sys_fstat(SCARG(uap, fd), &ub);
    300 	if (error == 0) {
    301 		compat_12_stat_conv(&ub, &oub);
    302 		error = copyout(&oub, SCARG(uap, sb), sizeof (oub));
    303 	}
    304 	return (error);
    305 }
    306