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freebsd-dev/sys/miscfs/devfs/devfs_vnops.c
Peter Wemm 7a204420d3 Don't silently accept attempts to change flags where they are not 
supported.
1998-06-10 06:34:57 +00:00

1569 lines
39 KiB
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/*
* Copyright 1997,1998 Julian Elischer. All rights reserved.
* julian@freebsd.org
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``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 HOLDER 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.
*
* $Id: devfs_vnops.c,v 1.55 1998/05/07 04:58:32 msmith Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h>/* definitions of spec functions we use */
#include <sys/dirent.h>
#include <miscfs/devfs/devfsdefs.h>
/*
* Insert description here
*/
/*
* Convert a component of a pathname into a pointer to a locked node.
* This is a very central and rather complicated routine.
* If the file system is not maintained in a strict tree hierarchy,
* this can result in a deadlock situation (see comments in code below).
*
* The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
* whether the name is to be looked up, created, renamed, or deleted.
* When CREATE, RENAME, or DELETE is specified, information usable in
* creating, renaming, or deleting a directory entry may be calculated.
* If flag has LOCKPARENT or'ed into it and the target of the pathname
* exists, lookup returns both the target and its parent directory locked.
* When creating or renaming and LOCKPARENT is specified, the target may
* not be ".". When deleting and LOCKPARENT is specified, the target may
* be "."., but the caller must check to ensure it does an vrele and DNUNLOCK
* instead of two DNUNLOCKs.
*
* Overall outline of devfs_lookup:
*
* check accessibility of directory
* null terminate the component (lookup leaves the whole string alone)
* look for name in cache, if found, then if at end of path
* and deleting or creating, drop it, else return name
* search for name in directory, to found or notfound
* notfound:
* if creating, return locked directory,
* else return error
* found:
* if at end of path and deleting, return information to allow delete
* if at end of path and rewriting (RENAME and LOCKPARENT), lock target
* node and return info to allow rewrite
* if not at end, add name to cache; if at end and neither creating
* nor deleting, add name to cache
* On return to lookup, remove the null termination we put in at the start.
*
* NOTE: (LOOKUP | LOCKPARENT) currently returns the parent node unlocked.
*/
static int
devfs_lookup(struct vop_lookup_args *ap)
/*struct vop_lookup_args {
struct vnode * a_dvp; directory vnode ptr
struct vnode ** a_vpp; where to put the result
struct componentname * a_cnp; the name we want
};*/
{
struct componentname *cnp = ap->a_cnp;
struct vnode *dir_vnode = ap->a_dvp;
struct vnode **result_vnode = ap->a_vpp;
dn_p dir_node; /* the directory we are searching */
dn_p new_node; /* the node we are searching for */
devnm_p new_nodename;
int flags = cnp->cn_flags;
int op = cnp->cn_nameiop; /* LOOKUP, CREATE, RENAME, or DELETE */
int lockparent = flags & LOCKPARENT;
int wantparent = flags & (LOCKPARENT|WANTPARENT);
int error = 0;
struct proc *p = cnp->cn_proc;
char heldchar; /* the char at the end of the name componet */
*result_vnode = NULL; /* safe not sorry */ /*XXX*/
DBPRINT(("lookup\n"));
if (dir_vnode->v_usecount == 0)
printf("dir had no refs ");
if (devfs_vntodn(dir_vnode,&dir_node))
{
printf("vnode has changed?\n");
vprint("=",dir_vnode);
return(EINVAL);
}
/*
* Check accessiblity of directory.
*/
if (dir_node->type != DEV_DIR) /* XXX or symlink? */
{
return (ENOTDIR);
}
if (error = VOP_ACCESS(dir_vnode, VEXEC, cnp->cn_cred, p))
{
return (error);
}
/*
* We now have a segment name to search for, and a directory to search.
*
*/
/***********************************************************************\
* SEARCH FOR NAME *
* while making sure the component is null terminated for the strcmp *
\***********************************************************************/
heldchar = cnp->cn_nameptr[cnp->cn_namelen];
cnp->cn_nameptr[cnp->cn_namelen] = '\0';
new_nodename = dev_findname(dir_node,cnp->cn_nameptr);
cnp->cn_nameptr[cnp->cn_namelen] = heldchar;
if(!new_nodename) {
/*******************************************************\
* Failed to find it.. (That may be good) *
\*******************************************************/
new_node = NULL; /* to be safe */
/*
* If creating, and at end of pathname
* then can consider
* allowing file to be created.
*/
if (!(flags & ISLASTCN) || !(op == CREATE || op == RENAME)) {
return ENOENT;
}
/*
* Access for write is interpreted as allowing
* creation of files in the directory.
*/
if (error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p))
{
DBPRINT(("MKACCESS "));
return (error);
}
/*
* We return with the directory locked, so that
* the parameters we set up above will still be
* valid if we actually decide to add a new entry.
* We return ni_vp == NULL to indicate that the entry
* does not currently exist; we leave a pointer to
* the (locked) directory vnode in namei_data->ni_dvp.
* The pathname buffer is saved so that the name
* can be obtained later.
*
* NB - if the directory is unlocked, then this
* information cannot be used.
*/
cnp->cn_flags |= SAVENAME; /*XXX why? */
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (EJUSTRETURN);
}
/***************************************************************\
* Found it.. this is not always a good thing.. *
\***************************************************************/
new_node = new_nodename->dnp;
new_node->last_lookup = new_nodename; /* for unlink */
/*
* If deleting, and at end of pathname, return
* parameters which can be used to remove file.
* If the wantparent flag isn't set, we return only
* the directory (in namei_data->ni_dvp), otherwise we go
* on and lock the node, being careful with ".".
*/
if (op == DELETE && (flags & ISLASTCN)) {
/*
* Write access to directory required to delete files.
*/
if (error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p))
return (error);
/*
* we are trying to delete '.'. What does this mean? XXX
*/
if (dir_node == new_node) {
VREF(dir_vnode);
*result_vnode = dir_vnode;
return (0);
}
/*
* If directory is "sticky", then user must own
* the directory, or the file in it, else she
* may not delete it (unless she's root). This
* implements append-only directories.
*/
devfs_dntovn(new_node,result_vnode);
#ifdef NOTYET
if ((dir_node->mode & ISVTX) &&
cnp->cn_cred->cr_uid != 0 &&
cnp->cn_cred->cr_uid != dir_node->uid &&
cnp->cn_cred->cr_uid != new_node->uid) {
VOP_UNLOCK(*result_vnode, 0, p);
return (EPERM);
}
#endif
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (0);
}
/*
* If rewriting (RENAME), return the vnode and the
* information required to rewrite the present directory
* Must get node of directory entry to verify it's a
* regular file, or empty directory.
*/
if (op == RENAME && wantparent && (flags & ISLASTCN)) {
/*
* Are we allowed to change the holding directory?
*/
if (error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p))
return (error);
/*
* Careful about locking second node.
* This can only occur if the target is ".".
*/
if (dir_node == new_node)
return (EISDIR);
devfs_dntovn(new_node,result_vnode);
/* hmm save the 'from' name (we need to delete it) */
cnp->cn_flags |= SAVENAME;
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (0);
}
/*
* Step through the translation in the name. We do not unlock the
* directory because we may need it again if a symbolic link
* is relative to the current directory. Instead we save it
* unlocked as "saved_dir_node" XXX. We must get the target
* node before unlocking
* the directory to insure that the node will not be removed
* before we get it. We prevent deadlock by always fetching
* nodes from the root, moving down the directory tree. Thus
* when following backward pointers ".." we must unlock the
* parent directory before getting the requested directory.
* There is a potential race condition here if both the current
* and parent directories are removed before the lock for the
* node associated with ".." returns. We hope that this occurs
* infrequently since we cannot avoid this race condition without
* implementing a sophisticated deadlock detection algorithm.
* Note also that this simple deadlock detection scheme will not
* work if the file system has any hard links other than ".."
* that point backwards in the directory structure.
*/
if (flags & ISDOTDOT) {
VOP_UNLOCK(dir_vnode, 0, p); /* race to get the node */
devfs_dntovn(new_node,result_vnode);
if (lockparent && (flags & ISLASTCN))
vn_lock(dir_vnode, LK_EXCLUSIVE | LK_RETRY, p);
} else if (dir_node == new_node) {
VREF(dir_vnode); /* we want ourself, ie "." */
*result_vnode = dir_vnode;
} else {
devfs_dntovn(new_node,result_vnode);
if (!lockparent || (flags & ISLASTCN))
VOP_UNLOCK(dir_vnode, 0, p);
}
DBPRINT(("GOT\n"));
return (0);
}
/*
* Create a regular file.
* We must also free the pathname buffer pointed at
* by ndp->ni_pnbuf, always on error, or only if the
* SAVESTART bit in ni_nameiop is clear on success.
* <still true in 4.4?>
*
* Always error... no such thing in this FS
*/
#ifdef notyet
static int
devfs_create(struct vop_mknod_args *ap)
/*struct vop_mknod_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */
{
DBPRINT(("create\n"));
return EINVAL;
}
static int
devfs_mknod( struct vop_mknod_args *ap)
/*struct vop_mknod_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */
{
int error;
DBPRINT(("mknod\n"));
switch (ap->a_vap->va_type) {
case VDIR:
#ifdef VNSLEAZE
return devfs_mkdir(ap);
/*XXX check for WILLRELE settings (different)*/
#else
error = VOP_MKDIR(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap);
#endif
break;
/*
* devfs_create() sets ndp->ni_vp.
*/
case VREG:
#ifdef VNSLEAZE
return devfs_create(ap);
/*XXX check for WILLRELE settings (different)*/
#else
error = VOP_CREATE(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap);
#endif
break;
default:
return EINVAL;
break;
}
return error;
}
#endif /* notyet */
static int
devfs_access(struct vop_access_args *ap)
/*struct vop_access_args {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */
{
/*
* mode is filled with a combination of VREAD, VWRITE,
* and/or VEXEC bits turned on. In an octal number these
* are the Y in 0Y00.
*/
struct vnode *vp = ap->a_vp;
int mode = ap->a_mode;
struct ucred *cred = ap->a_cred;
dn_p file_node;
int error;
gid_t *gp;
int i;
DBPRINT(("access\n"));
if (error = devfs_vntodn(vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
/*
* if we are not running as a process, we are in the
* kernel and we DO have permission
*/
if (ap->a_p == NULL)
return 0;
/*
* Access check is based on only one of owner, group, public.
* If not owner, then check group. If not a member of the
* group, then check public access.
*/
if (cred->cr_uid != file_node->uid)
{
/* failing that.. try groups */
mode >>= 3;
gp = cred->cr_groups;
for (i = 0; i < cred->cr_ngroups; i++, gp++)
{
if (file_node->gid == *gp)
{
goto found;
}
}
/* failing that.. try general access */
mode >>= 3;
found:
;
}
if ((file_node->mode & mode) == mode)
return (0);
/*
* Root gets to do anything.
* but only use suser prives as a last resort
* (Use of super powers is recorded in ap->a_p->p_acflag)
*/
if( suser(cred, &ap->a_p->p_acflag) == 0) /* XXX what if no proc? */
return 0;
return (EACCES);
}
static int
devfs_getattr(struct vop_getattr_args *ap)
/*struct vop_getattr_args {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
dn_p file_node;
int error;
DBPRINT(("getattr\n"));
if (error = devfs_vntodn(vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
vap->va_rdev = 0;/* default value only */
vap->va_mode = file_node->mode;
switch (file_node->type)
{
case DEV_DIR:
vap->va_rdev = (dev_t)file_node->dvm;
vap->va_mode |= (S_IFDIR);
break;
case DEV_CDEV:
vap->va_rdev = file_node->by.Cdev.dev;
vap->va_mode |= (S_IFCHR);
break;
case DEV_BDEV:
vap->va_rdev = file_node->by.Bdev.dev;
vap->va_mode |= (S_IFBLK);
break;
case DEV_SLNK:
break;
}
vap->va_type = vp->v_type;
vap->va_nlink = file_node->links;
vap->va_uid = file_node->uid;
vap->va_gid = file_node->gid;
vap->va_fsid = (long)file_node->dvm;
vap->va_fileid = (long)file_node;
vap->va_size = file_node->len; /* now a u_quad_t */
vap->va_blocksize = 512;
/*
* XXX If the node times are in Jan 1, 1970, then
* update them to the boot time.
* When we made the node, the date/time was not yet known.
*/
if(file_node->ctime.tv_sec < (24 * 3600))
{
TIMEVAL_TO_TIMESPEC(&boottime,&(file_node->ctime));
TIMEVAL_TO_TIMESPEC(&boottime,&(file_node->mtime));
TIMEVAL_TO_TIMESPEC(&boottime,&(file_node->atime));
}
vap->va_ctime = file_node->ctime;
vap->va_mtime = file_node->mtime;
vap->va_atime = file_node->atime;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_bytes = file_node->len; /* u_quad_t */
vap->va_filerev = 0; /* XXX */ /* u_quad_t */
vap->va_vaflags = 0; /* XXX */
return 0;
}
static int
devfs_setattr(struct vop_setattr_args *ap)
/*struct vop_setattr_args {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
struct ucred *cred = ap->a_cred;
struct proc *p = ap->a_p;
int error = 0;
gid_t *gp;
int i;
dn_p file_node;
if (vap->va_flags != VNOVAL) /* XXX needs to be implemented */
return (EOPNOTSUPP);
if (error = devfs_vntodn(vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
DBPRINT(("setattr\n"));
if ((vap->va_type != VNON) ||
(vap->va_nlink != VNOVAL) ||
(vap->va_fsid != VNOVAL) ||
(vap->va_fileid != VNOVAL) ||
(vap->va_blocksize != VNOVAL) ||
(vap->va_rdev != VNOVAL) ||
(vap->va_bytes != VNOVAL) ||
(vap->va_gen != VNOVAL ))
{
return EINVAL;
}
/*
* Anyone can touch the files in such a way that the times are set
* to NOW (e.g. run 'touch') if they have write permissions
* however only the owner or root can set "un-natural times.
* They also don't need write permissions.
*/
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
#if 0 /*
* This next test is pointless under devfs for now..
* as there is only one devfs hiding under potentially many
* mountpoints and actual device node are really 'mounted' under
* a FAKE mountpoint inside the kernel only, no matter where it
* APPEARS they are mounted to the outside world..
* A readonly devfs doesn't exist anyway.
*/
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
#endif
if (((vap->va_vaflags & VA_UTIMES_NULL) == 0) &&
(cred->cr_uid != file_node->uid) &&
suser(cred, &p->p_acflag))
return (EPERM);
if(VOP_ACCESS(vp, VWRITE, cred, p))
return (EACCES);
file_node->atime = vap->va_atime;
file_node->mtime = vap->va_mtime;
nanotime(&file_node->ctime);
return (0);
}
/*
* Change the permissions.. must be root or owner to do this.
*/
if (vap->va_mode != (u_short)VNOVAL) {
if ((cred->cr_uid != file_node->uid)
&& suser(cred, &p->p_acflag))
return (EPERM);
/* set drwxwxrwx stuff */
file_node->mode &= ~07777;
file_node->mode |= vap->va_mode & 07777;
}
/*
* Change the owner.. must be root to do this.
*/
if (vap->va_uid != (uid_t)VNOVAL) {
if (suser(cred, &p->p_acflag))
return (EPERM);
file_node->uid = vap->va_uid;
}
/*
* Change the group.. must be root or owner to do this.
* If we are the owner, we must be in the target group too.
* don't use suser() unless you have to as it reports
* whether you needed suser powers or not.
*/
if (vap->va_gid != (gid_t)VNOVAL) {
if (cred->cr_uid == file_node->uid){
gp = cred->cr_groups;
for (i = 0; i < cred->cr_ngroups; i++, gp++) {
if (vap->va_gid == *gp)
goto cando;
}
}
/*
* we can't do it with normal privs,
* do we have an ace up our sleeve?
*/
if( suser(cred, &p->p_acflag))
return (EPERM);
cando:
file_node->gid = vap->va_gid;
}
#if 0
/*
* Copied from somewhere else
* but only kept as a marker and reminder of the fact that
* flags should be handled some day
*/
if (vap->va_flags != VNOVAL) {
if (error = suser(cred, &p->p_acflag))
return error;
if (cred->cr_uid == 0)
;
else {
}
}
#endif
return error;
}
static int
devfs_read(struct vop_read_args *ap)
/*struct vop_read_args {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */
{
int error = 0;
dn_p file_node;
DBPRINT(("read\n"));
if (error = devfs_vntodn(ap->a_vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
switch (ap->a_vp->v_type) {
case VREG:
return(EINVAL);
case VDIR:
return VOP_READDIR(ap->a_vp,ap->a_uio,ap->a_cred,
NULL,NULL,NULL);
case VCHR:
case VBLK:
error = VOCALL(spec_vnodeop_p, VOFFSET(vop_read), ap);
getnanotime(&(file_node->atime));
return(error);
default:
panic("devfs_read(): bad file type");
break;
}
}
/*
* Write data to a file or directory.
*/
static int
devfs_write(struct vop_write_args *ap)
/*struct vop_write_args {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */
{
dn_p file_node;
int error;
DBPRINT(("write\n"));
if (error = devfs_vntodn(ap->a_vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
switch (ap->a_vp->v_type) {
case VREG:
return(EINVAL);
case VDIR:
return(EISDIR);
case VCHR:
case VBLK:
error = VOCALL(spec_vnodeop_p, VOFFSET(vop_write), ap);
getnanotime(&(file_node->mtime));
return(error);
default:
panic("devfs_write(): bad file type");
break;
}
}
/* presently not called from devices anyhow */
#ifdef notyet
static int
devfs_ioctl(struct vop_ioctl_args *ap)
/*struct vop_ioctl_args {
struct vnode *a_vp;
int a_command;
caddr_t a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */
{
DBPRINT(("ioctl\n"));
return ENOTTY;
}
static int
devfs_select(struct vop_select_args *ap)
/*struct vop_select_args {
struct vnode *a_vp;
int a_which;
int a_fflags;
struct ucred *a_cred;
struct proc *a_p;
} */
{
DBPRINT(("select\n"));
return 1; /* filesystems never block? */
}
#endif /* notyet */
static int
devfs_remove(struct vop_remove_args *ap)
/*struct vop_remove_args {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */
{
struct vnode *vp = ap->a_vp;
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
dn_p tp, tdp;
devnm_p tnp;
int doingdirectory = 0;
int error = 0;
uid_t ouruid = cnp->cn_cred->cr_uid;
DBPRINT(("remove\n"));
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if (error = devfs_vntodn(dvp, &tdp)) {
abortit:
VOP_ABORTOP(dvp, cnp);
return (error);
}
if (error = devfs_vntodn(vp, &tp)) goto abortit;
/*
* Assuming we are atomic, dev_lookup left this for us
*/
tnp = tp->last_lookup;
/*
* Check we are doing legal things WRT the new flags
*/
if ((tp->flags & (IMMUTABLE | APPEND))
|| (tdp->flags & APPEND) /*XXX eh?*/ ) {
error = EPERM;
goto abortit;
}
/*
* Make sure that we don't try do something stupid
*/
if ((tp->type) == DEV_DIR) {
/*
* Avoid ".", "..", and aliases of "." for obvious reasons.
*/
if ( (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.')
|| (cnp->cn_flags&ISDOTDOT) ) {
error = EINVAL;
goto abortit;
}
doingdirectory++;
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(tdp->mtime));
/*
* own the parent directory, or the destination of the rename,
* otherwise the destination may not be changed (except by
* root). This implements append-only directories.
* XXX shoudn't this be in generic code?
*/
if ((tdp->mode & S_ISTXT)
&& ouruid != 0
&& ouruid != tdp->uid
&& ouruid != tp->uid ) {
error = EPERM;
goto abortit;
}
/*
* Target must be empty if a directory and have no links
* to it. Also, ensure source and target are compatible
* (both directories, or both not directories).
*/
if (( doingdirectory) && (tp->links > 2)) {
printf("nlink = %d\n",tp->links); /*XXX*/
error = ENOTEMPTY;
goto abortit;
}
dev_free_name(tnp);
tp = NULL;
return (error);
}
/*
*/
static int
devfs_link(struct vop_link_args *ap)
/*struct vop_link_args {
struct vnode *a_tdvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */
{
struct vnode *vp = ap->a_vp;
struct vnode *tdvp = ap->a_tdvp;
struct componentname *cnp = ap->a_cnp;
dn_p fp, tdp;
devnm_p tnp;
int error = 0;
DBPRINT(("link\n"));
/*
* First catch an arbitrary restriction for this FS
*/
if(cnp->cn_namelen > DEVMAXNAMESIZE) {
error = ENAMETOOLONG;
goto abortit;
}
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if ( error = devfs_vntodn(tdvp,&tdp)) goto abortit;
if ( error = devfs_vntodn(vp,&fp)) goto abortit;
/*
* trying to move it out of devfs? (v_tag == VT_DEVFS)
*/
if ( (vp->v_tag != VT_DEVFS)
|| (vp->v_tag != tdvp->v_tag) ) {
error = EXDEV;
abortit:
VOP_ABORTOP(tdvp, cnp);
goto out;
}
/*
* Check we are doing legal things WRT the new flags
*/
if (fp->flags & (IMMUTABLE | APPEND)) {
error = EPERM;
goto abortit;
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(tdp->atime));
error = dev_add_name(cnp->cn_nameptr,
tdp,
NULL,
fp,
&tnp);
out:
return (error);
}
/*
* Rename system call. Seems overly complicated to me...
* rename("foo", "bar");
* is essentially
* unlink("bar");
* link("foo", "bar");
* unlink("foo");
* but ``atomically''.
*
* When the target exists, both the directory
* and target vnodes are locked.
* the source and source-parent vnodes are referenced
*
*
* Basic algorithm is:
*
* 1) Bump link count on source while we're linking it to the
* target. This also ensure the inode won't be deleted out
* from underneath us while we work (it may be truncated by
* a concurrent `trunc' or `open' for creation).
* 2) Link source to destination. If destination already exists,
* delete it first.
* 3) Unlink source reference to node if still around. If a
* directory was moved and the parent of the destination
* is different from the source, patch the ".." entry in the
* directory.
*/
static int
devfs_rename(struct vop_rename_args *ap)
/*struct vop_rename_args {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */
{
struct vnode *tvp = ap->a_tvp;
struct vnode *tdvp = ap->a_tdvp;
struct vnode *fvp = ap->a_fvp;
struct vnode *fdvp = ap->a_fdvp;
struct componentname *tcnp = ap->a_tcnp;
struct componentname *fcnp = ap->a_fcnp;
struct proc *p = fcnp->cn_proc;
dn_p fp, fdp, tp, tdp;
devnm_p fnp,tnp;
int doingdirectory = 0;
int error = 0;
/*
* First catch an arbitrary restriction for this FS
*/
if(tcnp->cn_namelen > DEVMAXNAMESIZE) {
error = ENAMETOOLONG;
goto abortit;
}
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if ( error = devfs_vntodn(tdvp,&tdp)) goto abortit;
if ( error = devfs_vntodn(fdvp,&fdp)) goto abortit;
if ( error = devfs_vntodn(fvp,&fp)) goto abortit;
fnp = fp->last_lookup;
if (tvp) {
if ( error = devfs_vntodn(tvp,&tp)) goto abortit;
tnp = tp->last_lookup;
} else {
tp = NULL;
tnp = NULL;
}
/*
* trying to move it out of devfs? (v_tag == VT_DEVFS)
* if we move a dir across mnt points. we need to fix all
* the mountpoint pointers! XXX
* so for now keep dirs within the same mount
*/
if ( (fvp->v_tag != VT_DEVFS)
|| (fvp->v_tag != tdvp->v_tag)
|| (tvp && (fvp->v_tag != tvp->v_tag))
|| ((fp->type == DEV_DIR) && (fp->dvm != tdp->dvm ))) {
error = EXDEV;
abortit:
VOP_ABORTOP(tdvp, tcnp);
if (tdvp == tvp) /* eh? */
vrele(tdvp);
else
vput(tdvp);
if (tvp)
vput(tvp);
VOP_ABORTOP(fdvp, fcnp); /* XXX, why not in NFS? */
vrele(fdvp);
vrele(fvp);
return (error);
}
/*
* Check we are doing legal things WRT the new flags
*/
if ((tp && (tp->flags & (IMMUTABLE | APPEND)))
|| (fp->flags & (IMMUTABLE | APPEND))
|| (fdp->flags & APPEND)) {
error = EPERM;
goto abortit;
}
/*
* Make sure that we don't try do something stupid
*/
if ((fp->type) == DEV_DIR) {
/*
* Avoid ".", "..", and aliases of "." for obvious reasons.
*/
if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.')
|| (fcnp->cn_flags&ISDOTDOT)
|| (tcnp->cn_namelen == 1 && tcnp->cn_nameptr[0] == '.')
|| (tcnp->cn_flags&ISDOTDOT)
|| (tdp == fp )) {
error = EINVAL;
goto abortit;
}
doingdirectory++;
}
/*
* If ".." must be changed (ie the directory gets a new
* parent) then the source directory must not be in the
* directory heirarchy above the target, as this would
* orphan everything below the source directory. Also
* the user must have write permission in the source so
* as to be able to change "..".
*/
if (doingdirectory && (tdp != fdp)) {
dn_p tmp,ntmp;
error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
tmp = tdp;
do {
if(tmp == fp) {
/* XXX unlock stuff here probably */
error = EINVAL;
goto out;
}
ntmp = tmp;
} while ((tmp = tmp->by.Dir.parent) != ntmp);
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(fp->atime));
/*
* Check if just deleting a link name.
*/
if (fvp == tvp) {
if (fvp->v_type == VDIR) {
error = EINVAL;
goto abortit;
}
/* Release destination completely. */
VOP_ABORTOP(tdvp, tcnp);
vput(tdvp);
vput(tvp);
/* Delete source. */
VOP_ABORTOP(fdvp, fcnp); /*XXX*/
vrele(fdvp);
vrele(fvp);
dev_free_name(fnp);
return 0;
}
/*
* 1) Bump link count while we're moving stuff
* around. If we crash somewhere before
* completing our work, too bad :)
*/
fp->links++;
/*
* If the target exists zap it (unless it's a non-empty directory)
* We could do that as well but won't
*/
if (tp) {
int ouruid = tcnp->cn_cred->cr_uid;
/*
* If the parent directory is "sticky", then the user must
* own the parent directory, or the destination of the rename,
* otherwise the destination may not be changed (except by
* root). This implements append-only directories.
* XXX shoudn't this be in generic code?
*/
if ((tdp->mode & S_ISTXT)
&& ouruid != 0
&& ouruid != tdp->uid
&& ouruid != tp->uid ) {
error = EPERM;
goto bad;
}
/*
* Target must be empty if a directory and have no links
* to it. Also, ensure source and target are compatible
* (both directories, or both not directories).
*/
if (( doingdirectory) && (tp->links > 2)) {
printf("nlink = %d\n",tp->links); /*XXX*/
error = ENOTEMPTY;
goto bad;
}
dev_free_name(tnp);
tp = NULL;
}
dev_add_name(tcnp->cn_nameptr,tdp,fnp->as.front.realthing,fp,&tnp);
fnp->dnp = NULL;
fp->links--; /* one less link to it.. */
dev_free_name(fnp);
fp->links--; /* we added one earlier*/
if (tdp)
vput(tdvp);
if (tp)
vput(fvp);
vrele(ap->a_fvp);
return (error);
bad:
if (tp)
vput(tvp);
vput(tdvp);
out:
if (vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY, p) == 0) {
fp->links--; /* we added one earlier*/
vput(fvp);
} else
vrele(fvp);
return (error);
}
#ifdef notyet
static int
devfs_mkdir(struct vop_mkdir_args *ap)
/*struct vop_mkdir_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */
{
DBPRINT(("mkdir\n"));
vput(ap->a_dvp);
return EINVAL;
}
static int
devfs_rmdir(struct vop_rmdir_args *ap)
/*struct vop_rmdir_args {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */
{
DBPRINT(("rmdir\n"));
return (0);
}
#endif
static int
devfs_symlink(struct vop_symlink_args *ap)
/*struct vop_symlink_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */
{
struct vnode *vp;
int error;
dn_p dnp;
union typeinfo by;
devnm_p nm_p;
DBPRINT(("symlink\n"));
if(error = devfs_vntodn(ap->a_dvp, &dnp)) {
return (error);
}
by.Slnk.name = ap->a_target;
by.Slnk.namelen = strlen(ap->a_target);
dev_add_entry(ap->a_cnp->cn_nameptr, dnp, DEV_SLNK, &by,
NULL, NULL, &nm_p);
if(error = devfs_dntovn(nm_p->dnp, &vp)) {
return (error);
}
VOP_SETATTR(vp, ap->a_vap, ap->a_cnp->cn_cred, ap->a_cnp->cn_proc);
*ap->a_vpp = NULL;
vput(vp);
return 0;
}
/*
* Vnode op for readdir
*/
static int
devfs_readdir(struct vop_readdir_args *ap)
/*struct vop_readdir_args {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *eofflag;
int *ncookies;
u_int **cookies;
} */
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct dirent dirent;
dn_p dir_node;
devnm_p name_node;
char *name;
int error = 0;
int reclen;
int nodenumber;
int startpos,pos;
DBPRINT(("readdir\n"));
/* set up refs to dir */
if (error = devfs_vntodn(vp,&dir_node))
return error;
if(dir_node->type != DEV_DIR)
return(ENOTDIR);
pos = 0;
startpos = uio->uio_offset;
name_node = dir_node->by.Dir.dirlist;
nodenumber = 0;
getnanotime(&(dir_node->atime));
while ((name_node || (nodenumber < 2)) && (uio->uio_resid > 0))
{
switch(nodenumber)
{
case 0:
dirent.d_fileno = (unsigned long int)dir_node;
name = ".";
dirent.d_namlen = 1;
dirent.d_type = DT_DIR;
break;
case 1:
if(dir_node->by.Dir.parent)
dirent.d_fileno
= (unsigned long int)dir_node->by.Dir.parent;
else
dirent.d_fileno = (unsigned long int)dir_node;
name = "..";
dirent.d_namlen = 2;
dirent.d_type = DT_DIR;
break;
default:
dirent.d_fileno =
(unsigned long int)name_node->dnp;
dirent.d_namlen = strlen(name_node->name);
name = name_node->name;
switch(name_node->dnp->type) {
case DEV_BDEV:
dirent.d_type = DT_BLK;
break;
case DEV_CDEV:
dirent.d_type = DT_CHR;
break;
case DEV_DDEV:
dirent.d_type = DT_SOCK; /*XXX*/
break;
case DEV_DIR:
dirent.d_type = DT_DIR;
break;
case DEV_SLNK:
dirent.d_type = DT_LNK;
break;
default:
dirent.d_type = DT_UNKNOWN;
}
}
reclen = dirent.d_reclen = GENERIC_DIRSIZ(&dirent);
if(pos >= startpos) /* made it to the offset yet? */
{
if (uio->uio_resid < reclen) /* will it fit? */
break;
strcpy( dirent.d_name,name);
if (error = uiomove ((caddr_t)&dirent,
dirent.d_reclen, uio))
break;
}
pos += reclen;
if((nodenumber >1) && name_node)
name_node = name_node->next;
nodenumber++;
}
uio->uio_offset = pos;
return (error);
}
/*
*/
static int
devfs_readlink(struct vop_readlink_args *ap)
/*struct vop_readlink_args {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
} */
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
dn_p lnk_node;
int error = 0;
DBPRINT(("readlink\n"));
/* set up refs to dir */
if (error = devfs_vntodn(vp,&lnk_node))
return error;
if(lnk_node->type != DEV_SLNK)
return(EINVAL);
if (error = VOP_ACCESS(vp, VREAD, ap->a_cred, NULL)) { /* XXX */
return error;
}
error = uiomove(lnk_node->by.Slnk.name, lnk_node->by.Slnk.namelen, uio);
return error;
}
#ifdef notyet
static int
devfs_abortop(struct vop_abortop_args *ap)
/*struct vop_abortop_args {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */
{
DBPRINT(("abortop\n"));
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
zfree(namei_zone, ap->a_cnp->cn_pnbuf);
return 0;
}
#endif /* notyet */
static int
devfs_inactive(struct vop_inactive_args *ap)
/*struct vop_inactive_args {
struct vnode *a_vp;
} */
{
DBPRINT(("inactive\n"));
return 0;
}
#ifdef notyet
static int
devfs_lock(struct vop_lock_args *ap)
{
DBPRINT(("lock\n"));
return 0;
}
static int
devfs_unlock( struct vop_unlock_args *ap)
{
DBPRINT(("unlock\n"));
return 0;
}
static int
devfs_islocked(struct vop_islocked_args *ap)
/*struct vop_islocked_args {
struct vnode *a_vp;
} */
{
DBPRINT(("islocked\n"));
return 0;
}
static int
devfs_bmap(struct vop_bmap_args *ap)
/*struct vop_bmap_args {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
} */
{
DBPRINT(("bmap\n"));
return 0;
}
static int
devfs_advlock(struct vop_advlock_args *ap)
/*struct vop_advlock_args {
struct vnode *a_vp;
caddr_t a_id;
int a_op;
struct flock *a_fl;
int a_flags;
} */
{
DBPRINT(("advlock\n"));
return EINVAL; /* we don't do locking yet */
}
#endif /* notyet */
static int
devfs_reclaim(struct vop_reclaim_args *ap)
/*struct vop_reclaim_args {
struct vnode *a_vp;
} */
{
dn_p file_node = NULL;
int error;
DBPRINT(("reclaim\n"));
if (error = devfs_vntodn(ap->a_vp,&file_node))
{
printf("devfs_vntodn returned %d ",error);
return error;
}
ap->a_vp->v_data = NULL;
if (file_node) {
file_node->vn = 0;
file_node->vn_id = 0;
}
return(0);
}
/*
* Print out the contents of a /devfs vnode.
*/
static int
devfs_print(struct vop_print_args *ap)
/*struct vop_print_args {
struct vnode *a_vp;
} */
{
printf("tag VT_DEVFS, devfs vnode\n");
return (0);
}
/**************************************************************************\
* pseudo ops *
\**************************************************************************/
/*
* /devfs vnode unsupported operation
*/
static int
devfs_enotsupp(void *junk)
{
return (EOPNOTSUPP);
}
/*
* /devfs "should never get here" operation
*/
static int
devfs_badop(void *junk)
{
panic("devfs: bad op");
/* NOTREACHED */
}
/*proto*/
void
devfs_dropvnode(dn_p dnp)
{
struct vnode *vn_p;
#ifdef PARANOID
if(!dnp)
{
printf("devfs: dn count dropped too early\n");
}
#endif
vn_p = dnp->vn;
/*
* check if we have a vnode.......
*/
if((vn_p) && ( dnp->vn_id == vn_p->v_id) && (dnp == (dn_p)vn_p->v_data))
{
VOP_REVOKE(vn_p, REVOKEALL);
}
dnp->vn = NULL; /* be pedantic about this */
}
/* These are the operations used by directories etc in a devfs */
vop_t **devfs_vnodeop_p;
static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_bmap_desc, (vop_t *) devfs_badop },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_inactive_desc, (vop_t *) devfs_inactive },
{ &vop_link_desc, (vop_t *) devfs_link },
{ &vop_lookup_desc, (vop_t *) devfs_lookup },
{ &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
{ &vop_print_desc, (vop_t *) devfs_print },
{ &vop_read_desc, (vop_t *) devfs_read },
{ &vop_readdir_desc, (vop_t *) devfs_readdir },
{ &vop_readlink_desc, (vop_t *) devfs_readlink },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_remove_desc, (vop_t *) devfs_remove },
{ &vop_rename_desc, (vop_t *) devfs_rename },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ &vop_symlink_desc, (vop_t *) devfs_symlink },
{ &vop_write_desc, (vop_t *) devfs_write },
{ NULL, NULL }
};
static struct vnodeopv_desc devfs_vnodeop_opv_desc =
{ &devfs_vnodeop_p, devfs_vnodeop_entries };
VNODEOP_SET(devfs_vnodeop_opv_desc);
vop_t **dev_spec_vnodeop_p;
static struct vnodeopv_entry_desc dev_spec_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) spec_vnoperate },
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_read_desc, (vop_t *) devfs_read },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ &vop_symlink_desc, (vop_t *) devfs_symlink },
{ &vop_write_desc, (vop_t *) devfs_write },
{ NULL, NULL }
};
static struct vnodeopv_desc dev_spec_vnodeop_opv_desc =
{ &dev_spec_vnodeop_p, dev_spec_vnodeop_entries };
VNODEOP_SET(dev_spec_vnodeop_opv_desc);
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