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NetBSD/sys/miscfs/kernfs/kernfs_vnops.c

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/* $NetBSD: kernfs_vnops.c,v 1.157 2017/04/11 14:25:01 riastradh Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95
*/
/*
* Kernel parameter filesystem (/kern)
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kernfs_vnops.c,v 1.157 2017/04/11 14:25:01 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/vmmeter.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/buf.h>
#include <sys/dirent.h>
#include <sys/msgbuf.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/kernfs/kernfs.h>
#include <miscfs/specfs/specdev.h>
#include <uvm/uvm_extern.h>
#define KSTRING 256 /* Largest I/O available via this filesystem */
#define UIO_MX 32
#define READ_MODE (S_IRUSR|S_IRGRP|S_IROTH)
#define WRITE_MODE (S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)
#define UREAD_MODE (S_IRUSR)
#define DIR_MODE (S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
#define UDIR_MODE (S_IRUSR|S_IXUSR)
#define N(s) sizeof(s)-1, s
const struct kern_target kern_targets[] = {
/* NOTE: The name must be less than UIO_MX-16 chars in length */
/* name data tag type ro/rw */
{ DT_DIR, N("."), 0, KFSkern, VDIR, DIR_MODE },
{ DT_DIR, N(".."), 0, KFSroot, VDIR, DIR_MODE },
{ DT_REG, N("boottime"), &boottime.tv_sec, KFSint, VREG, READ_MODE },
/* XXXUNCONST */
{ DT_REG, N("copyright"), __UNCONST(copyright),
KFSstring, VREG, READ_MODE },
{ DT_REG, N("hostname"), 0, KFShostname, VREG, WRITE_MODE },
{ DT_REG, N("hz"), &hz, KFSint, VREG, READ_MODE },
{ DT_REG, N("loadavg"), 0, KFSavenrun, VREG, READ_MODE },
{ DT_REG, N("msgbuf"), 0, KFSmsgbuf, VREG, READ_MODE },
{ DT_REG, N("pagesize"), &uvmexp.pagesize, KFSint, VREG, READ_MODE },
{ DT_REG, N("physmem"), &physmem, KFSint, VREG, READ_MODE },
#if 0
{ DT_DIR, N("root"), 0, KFSnull, VDIR, DIR_MODE },
#endif
{ DT_BLK, N("rootdev"), &rootdev, KFSdevice, VBLK, READ_MODE },
{ DT_CHR, N("rrootdev"), &rrootdev, KFSdevice, VCHR, READ_MODE },
{ DT_REG, N("time"), 0, KFStime, VREG, READ_MODE },
/* XXXUNCONST */
{ DT_REG, N("version"), __UNCONST(version),
KFSstring, VREG, READ_MODE },
};
const struct kern_target subdir_targets[] = {
/* NOTE: The name must be less than UIO_MX-16 chars in length */
/* name data tag type ro/rw */
{ DT_DIR, N("."), 0, KFSsubdir, VDIR, DIR_MODE },
{ DT_DIR, N(".."), 0, KFSkern, VDIR, DIR_MODE },
};
#undef N
SIMPLEQ_HEAD(,dyn_kern_target) dyn_kern_targets =
SIMPLEQ_HEAD_INITIALIZER(dyn_kern_targets);
int nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]);
const int static_nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]);
int nkern_dirs = 2;
int kernfs_try_fileop(kfstype, kfsfileop, void *, int);
int kernfs_try_xread(kfstype, const struct kernfs_node *, char **,
size_t, int);
int kernfs_try_xwrite(kfstype, const struct kernfs_node *, char *,
size_t, int);
static int kernfs_default_xread(void *v);
static int kernfs_default_xwrite(void *v);
static int kernfs_default_fileop_getattr(void *);
/* must include all fileop's */
const struct kernfs_fileop kernfs_default_fileops[] = {
{ .kf_fileop = KERNFS_XREAD },
{ .kf_fileop = KERNFS_XWRITE },
{ .kf_fileop = KERNFS_FILEOP_OPEN },
{ .kf_fileop = KERNFS_FILEOP_GETATTR,
.kf_vop = kernfs_default_fileop_getattr },
{ .kf_fileop = KERNFS_FILEOP_IOCTL },
{ .kf_fileop = KERNFS_FILEOP_CLOSE },
{ .kf_fileop = KERNFS_FILEOP_READ,
.kf_vop = kernfs_default_xread },
{ .kf_fileop = KERNFS_FILEOP_WRITE,
.kf_vop = kernfs_default_xwrite },
};
int kernfs_lookup(void *);
#define kernfs_create genfs_eopnotsupp
#define kernfs_mknod genfs_eopnotsupp
int kernfs_open(void *);
int kernfs_close(void *);
int kernfs_access(void *);
int kernfs_getattr(void *);
int kernfs_setattr(void *);
int kernfs_read(void *);
int kernfs_write(void *);
#define kernfs_fcntl genfs_fcntl
int kernfs_ioctl(void *);
#define kernfs_poll genfs_poll
#define kernfs_revoke genfs_revoke
#define kernfs_fsync genfs_nullop
#define kernfs_seek genfs_nullop
#define kernfs_remove genfs_eopnotsupp
int kernfs_link(void *);
#define kernfs_rename genfs_eopnotsupp
#define kernfs_mkdir genfs_eopnotsupp
#define kernfs_rmdir genfs_eopnotsupp
int kernfs_symlink(void *);
int kernfs_readdir(void *);
#define kernfs_readlink genfs_eopnotsupp
#define kernfs_abortop genfs_abortop
int kernfs_inactive(void *);
int kernfs_reclaim(void *);
#define kernfs_lock genfs_lock
#define kernfs_unlock genfs_unlock
#define kernfs_bmap genfs_badop
#define kernfs_strategy genfs_badop
int kernfs_print(void *);
#define kernfs_islocked genfs_islocked
int kernfs_pathconf(void *);
#define kernfs_advlock genfs_einval
#define kernfs_bwrite genfs_eopnotsupp
#define kernfs_putpages genfs_putpages
static int kernfs_xread(struct kernfs_node *, int, char **,
size_t, size_t *);
static int kernfs_xwrite(const struct kernfs_node *, char *, size_t);
int (**kernfs_vnodeop_p)(void *);
const struct vnodeopv_entry_desc kernfs_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, kernfs_lookup }, /* lookup */
{ &vop_create_desc, kernfs_create }, /* create */
{ &vop_mknod_desc, kernfs_mknod }, /* mknod */
{ &vop_open_desc, kernfs_open }, /* open */
{ &vop_close_desc, kernfs_close }, /* close */
{ &vop_access_desc, kernfs_access }, /* access */
{ &vop_getattr_desc, kernfs_getattr }, /* getattr */
{ &vop_setattr_desc, kernfs_setattr }, /* setattr */
{ &vop_read_desc, kernfs_read }, /* read */
{ &vop_write_desc, kernfs_write }, /* write */
{ &vop_fallocate_desc, genfs_eopnotsupp }, /* fallocate */
{ &vop_fdiscard_desc, genfs_eopnotsupp }, /* fdiscard */
{ &vop_fcntl_desc, kernfs_fcntl }, /* fcntl */
{ &vop_ioctl_desc, kernfs_ioctl }, /* ioctl */
{ &vop_poll_desc, kernfs_poll }, /* poll */
{ &vop_revoke_desc, kernfs_revoke }, /* revoke */
{ &vop_fsync_desc, kernfs_fsync }, /* fsync */
{ &vop_seek_desc, kernfs_seek }, /* seek */
{ &vop_remove_desc, kernfs_remove }, /* remove */
{ &vop_link_desc, kernfs_link }, /* link */
{ &vop_rename_desc, kernfs_rename }, /* rename */
{ &vop_mkdir_desc, kernfs_mkdir }, /* mkdir */
{ &vop_rmdir_desc, kernfs_rmdir }, /* rmdir */
{ &vop_symlink_desc, kernfs_symlink }, /* symlink */
{ &vop_readdir_desc, kernfs_readdir }, /* readdir */
{ &vop_readlink_desc, kernfs_readlink }, /* readlink */
{ &vop_abortop_desc, kernfs_abortop }, /* abortop */
{ &vop_inactive_desc, kernfs_inactive }, /* inactive */
{ &vop_reclaim_desc, kernfs_reclaim }, /* reclaim */
{ &vop_lock_desc, kernfs_lock }, /* lock */
{ &vop_unlock_desc, kernfs_unlock }, /* unlock */
{ &vop_bmap_desc, kernfs_bmap }, /* bmap */
{ &vop_strategy_desc, kernfs_strategy }, /* strategy */
{ &vop_print_desc, kernfs_print }, /* print */
{ &vop_islocked_desc, kernfs_islocked }, /* islocked */
{ &vop_pathconf_desc, kernfs_pathconf }, /* pathconf */
{ &vop_advlock_desc, kernfs_advlock }, /* advlock */
{ &vop_bwrite_desc, kernfs_bwrite }, /* bwrite */
{ &vop_putpages_desc, kernfs_putpages }, /* putpages */
{ NULL, NULL }
};
const struct vnodeopv_desc kernfs_vnodeop_opv_desc =
{ &kernfs_vnodeop_p, kernfs_vnodeop_entries };
static inline int
kernfs_fileop_compare(struct kernfs_fileop *a, struct kernfs_fileop *b)
{
if (a->kf_type < b->kf_type)
return -1;
if (a->kf_type > b->kf_type)
return 1;
if (a->kf_fileop < b->kf_fileop)
return -1;
if (a->kf_fileop > b->kf_fileop)
return 1;
return (0);
}
SPLAY_HEAD(kfsfileoptree, kernfs_fileop) kfsfileoptree =
SPLAY_INITIALIZER(kfsfileoptree);
SPLAY_PROTOTYPE(kfsfileoptree, kernfs_fileop, kf_node, kernfs_fileop_compare);
SPLAY_GENERATE(kfsfileoptree, kernfs_fileop, kf_node, kernfs_fileop_compare);
kfstype
kernfs_alloctype(int nkf, const struct kernfs_fileop *kf)
{
static u_char nextfreetype = KFSlasttype;
struct kernfs_fileop *dkf, *fkf, skf;
int i;
/* XXX need to keep track of dkf's memory if we support
deallocating types */
dkf = malloc(sizeof(kernfs_default_fileops), M_TEMP, M_WAITOK);
memcpy(dkf, kernfs_default_fileops, sizeof(kernfs_default_fileops));
for (i = 0; i < sizeof(kernfs_default_fileops) /
sizeof(kernfs_default_fileops[0]); i++) {
dkf[i].kf_type = nextfreetype;
SPLAY_INSERT(kfsfileoptree, &kfsfileoptree, &dkf[i]);
}
for (i = 0; i < nkf; i++) {
skf.kf_type = nextfreetype;
skf.kf_fileop = kf[i].kf_fileop;
if ((fkf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf)))
fkf->kf_vop = kf[i].kf_vop;
}
return nextfreetype++;
}
int
kernfs_try_fileop(kfstype type, kfsfileop fileop, void *v, int error)
{
struct kernfs_fileop *kf, skf;
skf.kf_type = type;
skf.kf_fileop = fileop;
if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf)))
if (kf->kf_vop)
return kf->kf_vop(v);
return error;
}
int
kernfs_try_xread(kfstype type, const struct kernfs_node *kfs, char **bfp,
size_t len, int error)
{
struct kernfs_fileop *kf, skf;
skf.kf_type = type;
skf.kf_fileop = KERNFS_XREAD;
if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf)))
if (kf->kf_xread)
return kf->kf_xread(kfs, bfp, len);
return error;
}
int
kernfs_try_xwrite(kfstype type, const struct kernfs_node *kfs, char *bf,
size_t len, int error)
{
struct kernfs_fileop *kf, skf;
skf.kf_type = type;
skf.kf_fileop = KERNFS_XWRITE;
if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf)))
if (kf->kf_xwrite)
return kf->kf_xwrite(kfs, bf, len);
return error;
}
int
kernfs_addentry(kernfs_parentdir_t *pkt, kernfs_entry_t *dkt)
{
struct kernfs_subdir *ks, *parent;
if (pkt == NULL) {
SIMPLEQ_INSERT_TAIL(&dyn_kern_targets, dkt, dkt_queue);
nkern_targets++;
if (dkt->dkt_kt.kt_vtype == VDIR)
nkern_dirs++;
} else {
parent = (struct kernfs_subdir *)pkt->kt_data;
SIMPLEQ_INSERT_TAIL(&parent->ks_entries, dkt, dkt_queue);
parent->ks_nentries++;
if (dkt->dkt_kt.kt_vtype == VDIR)
parent->ks_dirs++;
}
if (dkt->dkt_kt.kt_vtype == VDIR && dkt->dkt_kt.kt_data == NULL) {
ks = malloc(sizeof(struct kernfs_subdir),
M_TEMP, M_WAITOK);
SIMPLEQ_INIT(&ks->ks_entries);
ks->ks_nentries = 2; /* . and .. */
ks->ks_dirs = 2;
ks->ks_parent = pkt ? pkt : &kern_targets[0];
dkt->dkt_kt.kt_data = ks;
}
return 0;
}
static int
kernfs_xread(struct kernfs_node *kfs, int off, char **bufp, size_t len, size_t *wrlen)
{
const struct kern_target *kt;
int err;
kt = kfs->kfs_kt;
switch (kfs->kfs_type) {
case KFStime: {
struct timeval tv;
microtime(&tv);
snprintf(*bufp, len, "%lld %ld\n", (long long)tv.tv_sec,
(long)tv.tv_usec);
break;
}
case KFSint: {
int *ip = kt->kt_data;
snprintf(*bufp, len, "%d\n", *ip);
break;
}
case KFSstring: {
char *cp = kt->kt_data;
*bufp = cp;
break;
}
case KFSmsgbuf: {
long n;
/*
* deal with cases where the message buffer has
* become corrupted.
*/
if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) {
msgbufenabled = 0;
return (ENXIO);
}
/*
* Note that reads of /kern/msgbuf won't necessarily yield
* consistent results, if the message buffer is modified
* while the read is in progress. The worst that can happen
* is that incorrect data will be read. There's no way
* that this can crash the system unless the values in the
* message buffer header are corrupted, but that'll cause
* the system to die anyway.
*/
if (off >= msgbufp->msg_bufs) {
*wrlen = 0;
return (0);
}
n = msgbufp->msg_bufx + off;
if (n >= msgbufp->msg_bufs)
n -= msgbufp->msg_bufs;
len = min(msgbufp->msg_bufs - n, msgbufp->msg_bufs - off);
*bufp = msgbufp->msg_bufc + n;
*wrlen = len;
return (0);
}
case KFShostname: {
char *cp = hostname;
size_t xlen = hostnamelen;
if (xlen >= (len - 2))
return (EINVAL);
memcpy(*bufp, cp, xlen);
(*bufp)[xlen] = '\n';
(*bufp)[xlen+1] = '\0';
break;
}
case KFSavenrun:
averunnable.fscale = FSCALE;
snprintf(*bufp, len, "%d %d %d %ld\n",
averunnable.ldavg[0], averunnable.ldavg[1],
averunnable.ldavg[2], averunnable.fscale);
break;
default:
err = kernfs_try_xread(kfs->kfs_type, kfs, bufp, len,
EOPNOTSUPP);
if (err)
return err;
}
len = strlen(*bufp);
if (len <= off)
*wrlen = 0;
else {
*bufp += off;
*wrlen = len - off;
}
return (0);
}
static int
kernfs_xwrite(const struct kernfs_node *kfs, char *bf, size_t len)
{
switch (kfs->kfs_type) {
case KFShostname:
if (bf[len-1] == '\n')
--len;
memcpy(hostname, bf, len);
hostname[len] = '\0';
hostnamelen = (size_t) len;
return (0);
default:
return kernfs_try_xwrite(kfs->kfs_type, kfs, bf, len, EIO);
}
}
/*
* vp is the current namei directory
* ndp is the name to locate in that directory...
*/
int
kernfs_lookup(void *v)
{
struct vop_lookup_v2_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap = v;
struct componentname *cnp = ap->a_cnp;
struct vnode **vpp = ap->a_vpp;
struct vnode *dvp = ap->a_dvp;
const char *pname = cnp->cn_nameptr;
const struct kernfs_node *kfs;
const struct kern_target *kt;
const struct dyn_kern_target *dkt;
const struct kernfs_subdir *ks;
int error, i;
*vpp = NULLVP;
if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
return (EROFS);
if (cnp->cn_namelen == 1 && *pname == '.') {
*vpp = dvp;
vref(dvp);
return (0);
}
kfs = VTOKERN(dvp);
switch (kfs->kfs_type) {
case KFSkern:
/*
* Shouldn't get here with .. in the root node.
*/
if (cnp->cn_flags & ISDOTDOT)
return (EIO);
for (i = 0; i < static_nkern_targets; i++) {
kt = &kern_targets[i];
if (cnp->cn_namelen == kt->kt_namlen &&
memcmp(kt->kt_name, pname, cnp->cn_namelen) == 0)
goto found;
}
SIMPLEQ_FOREACH(dkt, &dyn_kern_targets, dkt_queue) {
if (cnp->cn_namelen == dkt->dkt_kt.kt_namlen &&
memcmp(dkt->dkt_kt.kt_name, pname, cnp->cn_namelen) == 0) {
kt = &dkt->dkt_kt;
goto found;
}
}
break;
found:
error = vcache_get(dvp->v_mount, &kt, sizeof(kt), vpp);
return error;
case KFSsubdir:
ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data;
if (cnp->cn_flags & ISDOTDOT) {
kt = ks->ks_parent;
goto found;
}
SIMPLEQ_FOREACH(dkt, &ks->ks_entries, dkt_queue) {
if (cnp->cn_namelen == dkt->dkt_kt.kt_namlen &&
memcmp(dkt->dkt_kt.kt_name, pname, cnp->cn_namelen) == 0) {
kt = &dkt->dkt_kt;
goto found;
}
}
break;
default:
return (ENOTDIR);
}
return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS);
}
int
kernfs_open(void *v)
{
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_OPEN, v, 0);
}
int
kernfs_close(void *v)
{
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_CLOSE, v, 0);
}
int
kernfs_access(void *v)
{
struct vop_access_args /* {
struct vnode *a_vp;
int a_mode;
kauth_cred_t a_cred;
} */ *ap = v;
struct vattr va;
int error;
if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred)) != 0)
return (error);
return kauth_authorize_vnode(ap->a_cred,
KAUTH_ACCESS_ACTION(ap->a_mode, ap->a_vp->v_type, va.va_mode),
ap->a_vp, NULL, genfs_can_access(va.va_type, va.va_mode,
va.va_uid, va.va_gid, ap->a_mode, ap->a_cred));
}
static int
kernfs_default_fileop_getattr(void *v)
{
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
kauth_cred_t a_cred;
} */ *ap = v;
struct vattr *vap = ap->a_vap;
vap->va_nlink = 1;
vap->va_bytes = vap->va_size = 0;
return 0;
}
int
kernfs_getattr(void *v)
{
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
struct kernfs_subdir *ks;
struct vattr *vap = ap->a_vap;
int error = 0;
char strbuf[KSTRING], *bf;
size_t nread, total;
vattr_null(vap);
vap->va_type = ap->a_vp->v_type;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_mode = kfs->kfs_mode;
vap->va_fileid = kfs->kfs_fileno;
vap->va_flags = 0;
vap->va_size = 0;
vap->va_blocksize = DEV_BSIZE;
/* Make all times be current TOD, except for the "boottime" node. */
if (kfs->kfs_kt->kt_namlen == 8 &&
!memcmp(kfs->kfs_kt->kt_name, "boottime", 8)) {
vap->va_ctime = boottime;
} else {
getnanotime(&vap->va_ctime);
}
vap->va_atime = vap->va_mtime = vap->va_ctime;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_rdev = 0;
vap->va_bytes = 0;
switch (kfs->kfs_type) {
case KFSkern:
vap->va_nlink = nkern_dirs;
vap->va_bytes = vap->va_size = DEV_BSIZE;
break;
case KFSdevice:
vap->va_nlink = 1;
vap->va_rdev = ap->a_vp->v_rdev;
break;
case KFSroot:
vap->va_nlink = 1;
vap->va_bytes = vap->va_size = DEV_BSIZE;
break;
case KFSsubdir:
ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data;
vap->va_nlink = ks->ks_dirs;
vap->va_bytes = vap->va_size = DEV_BSIZE;
break;
case KFSnull:
case KFStime:
case KFSint:
case KFSstring:
case KFShostname:
case KFSavenrun:
case KFSmsgbuf:
vap->va_nlink = 1;
total = 0;
do {
bf = strbuf;
error = kernfs_xread(kfs, total, &bf,
sizeof(strbuf), &nread);
total += nread;
} while (error == 0 && nread != 0);
vap->va_bytes = vap->va_size = total;
break;
default:
error = kernfs_try_fileop(kfs->kfs_type,
KERNFS_FILEOP_GETATTR, v, EINVAL);
break;
}
return (error);
}
/*ARGSUSED*/
int
kernfs_setattr(void *v)
{
/*
* Silently ignore attribute changes.
* This allows for open with truncate to have no
* effect until some data is written. I want to
* do it this way because all writes are atomic.
*/
return (0);
}
int
kernfs_default_xread(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct uio *uio = ap->a_uio;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
char strbuf[KSTRING], *bf;
int off;
size_t len;
int error;
if (ap->a_vp->v_type == VDIR)
return EISDIR;
off = (int)uio->uio_offset;
/* Don't allow negative offsets */
if (off < 0)
return EINVAL;
bf = strbuf;
if ((error = kernfs_xread(kfs, off, &bf, sizeof(strbuf), &len)) == 0)
error = uiomove(bf, len, uio);
return (error);
}
int
kernfs_read(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
if (kfs->kfs_type < KFSlasttype) {
/* use default function */
return kernfs_default_xread(v);
}
return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_READ, v,
EOPNOTSUPP);
}
static int
kernfs_default_xwrite(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
struct uio *uio = ap->a_uio;
int error;
size_t xlen;
char strbuf[KSTRING];
if (uio->uio_offset != 0)
return (EINVAL);
xlen = min(uio->uio_resid, KSTRING-1);
if ((error = uiomove(strbuf, xlen, uio)) != 0)
return (error);
if (uio->uio_resid != 0)
return (EIO);
strbuf[xlen] = '\0';
xlen = strlen(strbuf);
return (kernfs_xwrite(kfs, strbuf, xlen));
}
int
kernfs_write(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
if (kfs->kfs_type < KFSlasttype) {
/* use default function */
return kernfs_default_xwrite(v);
}
return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_WRITE, v,
EOPNOTSUPP);
}
int
kernfs_ioctl(void *v)
{
struct vop_ioctl_args /* {
const struct vnodeop_desc *a_desc;
struct vnode *a_vp;
u_long a_command;
void *a_data;
int a_fflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_IOCTL, v,
EPASSTHROUGH);
}
static int
kernfs_setdirentfileno_kt(struct dirent *d, const struct kern_target *kt,
struct vop_readdir_args *ap)
{
struct kernfs_node *kfs;
struct vnode *vp;
int error;
if ((error = vcache_get(ap->a_vp->v_mount, &kt, sizeof(kt), &vp)) != 0)
return error;
kfs = VTOKERN(vp);
d->d_fileno = kfs->kfs_fileno;
vrele(vp);
return 0;
}
static int
kernfs_setdirentfileno(struct dirent *d, off_t entry,
struct kernfs_node *thisdir_kfs, const struct kern_target *parent_kt,
const struct kern_target *kt, struct vop_readdir_args *ap)
{
const struct kern_target *ikt;
int error;
switch (entry) {
case 0:
d->d_fileno = thisdir_kfs->kfs_fileno;
return 0;
case 1:
ikt = parent_kt;
break;
default:
ikt = kt;
break;
}
if (ikt != thisdir_kfs->kfs_kt) {
if ((error = kernfs_setdirentfileno_kt(d, ikt, ap)) != 0)
return error;
} else
d->d_fileno = thisdir_kfs->kfs_fileno;
return 0;
}
int
kernfs_readdir(void *v)
{
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
kauth_cred_t a_cred;
int *a_eofflag;
off_t **a_cookies;
int a_*ncookies;
} */ *ap = v;
struct uio *uio = ap->a_uio;
struct dirent d;
struct kernfs_node *kfs = VTOKERN(ap->a_vp);
const struct kern_target *kt;
const struct dyn_kern_target *dkt = NULL;
const struct kernfs_subdir *ks;
off_t i, j;
int error;
off_t *cookies = NULL;
int ncookies = 0, n;
if (uio->uio_resid < UIO_MX)
return (EINVAL);
if (uio->uio_offset < 0)
return (EINVAL);
error = 0;
i = uio->uio_offset;
memset(&d, 0, sizeof(d));
d.d_reclen = UIO_MX;
ncookies = uio->uio_resid / UIO_MX;
switch (kfs->kfs_type) {
case KFSkern:
if (i >= nkern_targets)
return (0);
if (ap->a_ncookies) {
ncookies = min(ncookies, (nkern_targets - i));
cookies = malloc(ncookies * sizeof(off_t), M_TEMP,
M_WAITOK);
*ap->a_cookies = cookies;
}
n = 0;
for (; i < nkern_targets && uio->uio_resid >= UIO_MX; i++) {
if (i < static_nkern_targets)
kt = &kern_targets[i];
else {
if (dkt == NULL) {
dkt = SIMPLEQ_FIRST(&dyn_kern_targets);
for (j = static_nkern_targets; j < i &&
dkt != NULL; j++)
dkt = SIMPLEQ_NEXT(dkt, dkt_queue);
if (j != i)
break;
} else {
dkt = SIMPLEQ_NEXT(dkt, dkt_queue);
}
if (dkt == NULL)
break;
kt = &dkt->dkt_kt;
}
if (kt->kt_tag == KFSdevice) {
dev_t *dp = kt->kt_data;
struct vnode *fvp;
if (*dp == NODEV ||
!vfinddev(*dp, kt->kt_vtype, &fvp))
continue;
vrele(fvp);
}
if (kt->kt_tag == KFSmsgbuf) {
if (!msgbufenabled
|| msgbufp->msg_magic != MSG_MAGIC) {
continue;
}
}
d.d_namlen = kt->kt_namlen;
if ((error = kernfs_setdirentfileno(&d, i, kfs,
&kern_targets[0], kt, ap)) != 0)
break;
memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1);
d.d_type = kt->kt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
n++;
}
ncookies = n;
break;
case KFSroot:
if (i >= 2)
return 0;
if (ap->a_ncookies) {
ncookies = min(ncookies, (2 - i));
cookies = malloc(ncookies * sizeof(off_t), M_TEMP,
M_WAITOK);
*ap->a_cookies = cookies;
}
n = 0;
for (; i < 2 && uio->uio_resid >= UIO_MX; i++) {
kt = &kern_targets[i];
d.d_namlen = kt->kt_namlen;
d.d_fileno = KERNFS_FILENO(kt, kt->kt_tag, 0);
memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1);
d.d_type = kt->kt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
n++;
}
ncookies = n;
break;
case KFSsubdir:
ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data;
if (i >= ks->ks_nentries)
return (0);
if (ap->a_ncookies) {
ncookies = min(ncookies, (ks->ks_nentries - i));
cookies = malloc(ncookies * sizeof(off_t), M_TEMP,
M_WAITOK);
*ap->a_cookies = cookies;
}
dkt = SIMPLEQ_FIRST(&ks->ks_entries);
for (j = 0; j < i && dkt != NULL; j++)
dkt = SIMPLEQ_NEXT(dkt, dkt_queue);
n = 0;
for (; i < ks->ks_nentries && uio->uio_resid >= UIO_MX; i++) {
if (i < 2)
kt = &subdir_targets[i];
else {
/* check if ks_nentries lied to us */
if (dkt == NULL)
break;
kt = &dkt->dkt_kt;
dkt = SIMPLEQ_NEXT(dkt, dkt_queue);
}
if (kt->kt_tag == KFSdevice) {
dev_t *dp = kt->kt_data;
struct vnode *fvp;
if (*dp == NODEV ||
!vfinddev(*dp, kt->kt_vtype, &fvp))
continue;
vrele(fvp);
}
d.d_namlen = kt->kt_namlen;
if ((error = kernfs_setdirentfileno(&d, i, kfs,
ks->ks_parent, kt, ap)) != 0)
break;
memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1);
d.d_type = kt->kt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
n++;
}
ncookies = n;
break;
default:
error = ENOTDIR;
break;
}
if (ap->a_ncookies) {
if (error) {
if (cookies)
free(*ap->a_cookies, M_TEMP);
*ap->a_ncookies = 0;
*ap->a_cookies = NULL;
} else
*ap->a_ncookies = ncookies;
}
uio->uio_offset = i;
return (error);
}
int
kernfs_inactive(void *v)
{
struct vop_inactive_v2_args /* {
struct vnode *a_vp;
bool *a_recycle;
} */ *ap = v;
*ap->a_recycle = false;
return (0);
}
int
kernfs_reclaim(void *v)
{
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct kernfs_node *kfs = VTOKERN(vp);
vp->v_data = NULL;
mutex_enter(&kfs_lock);
TAILQ_REMOVE(&VFSTOKERNFS(vp->v_mount)->nodelist, kfs, kfs_list);
mutex_exit(&kfs_lock);
kmem_free(kfs, sizeof(struct kernfs_node));
return 0;
}
/*
* Return POSIX pathconf information applicable to special devices.
*/
int
kernfs_pathconf(void *v)
{
struct vop_pathconf_args /* {
struct vnode *a_vp;
int a_name;
register_t *a_retval;
} */ *ap = v;
switch (ap->a_name) {
case _PC_LINK_MAX:
*ap->a_retval = LINK_MAX;
return (0);
case _PC_MAX_CANON:
*ap->a_retval = MAX_CANON;
return (0);
case _PC_MAX_INPUT:
*ap->a_retval = MAX_INPUT;
return (0);
case _PC_PIPE_BUF:
*ap->a_retval = PIPE_BUF;
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
case _PC_VDISABLE:
*ap->a_retval = _POSIX_VDISABLE;
return (0);
case _PC_SYNC_IO:
*ap->a_retval = 1;
return (0);
default:
return (EINVAL);
}
/* NOTREACHED */
}
/*
* Print out the contents of a /dev/fd vnode.
*/
/* ARGSUSED */
int
kernfs_print(void *v)
{
printf("tag VT_KERNFS, kernfs vnode\n");
return (0);
}
int
kernfs_link(void *v)
{
struct vop_link_v2_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap = v;
VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
return (EROFS);
}
int
kernfs_symlink(void *v)
{
struct vop_symlink_v3_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */ *ap = v;
VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
return (EROFS);
}
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