freebsd-dev/sys/fs/portalfs/portal_vnops.c
Dag-Erling Smørgrav 0fc93d0b00 Trace attempts to open a portal device.
Ceterum censeo portalfs esse delendam.
2011-10-18 07:31:49 +00:00

587 lines
13 KiB
C

/*-
* 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.
* 4. 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.
*
* @(#)portal_vnops.c 8.14 (Berkeley) 5/21/95
*
* $FreeBSD$
*/
/*
* Portal Filesystem
*/
#include "opt_capsicum.h"
#include <sys/param.h>
#include <sys/capability.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/syscallsubr.h>
#include <sys/systm.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/vnode.h>
#include <fs/portalfs/portal.h>
#include <net/vnet.h>
static int portal_fileid = PORTAL_ROOTFILEID+1;
static void portal_closefd(struct thread *td, int fd);
static int portal_connect(struct socket *so, struct socket *so2);
static vop_getattr_t portal_getattr;
static vop_lookup_t portal_lookup;
static vop_open_t portal_open;
static vop_readdir_t portal_readdir;
static vop_reclaim_t portal_reclaim;
static vop_setattr_t portal_setattr;
static void
portal_closefd(td, fd)
struct thread *td;
int fd;
{
int error;
error = kern_close(td, fd);
/*
* We should never get an error, and there isn't anything
* we could do if we got one, so just print a message.
*/
if (error)
printf("portal_closefd: error = %d\n", error);
}
/*
* vp is the current namei directory
* cnp is the name to locate in that directory...
*/
static int
portal_lookup(ap)
struct vop_lookup_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap;
{
struct componentname *cnp = ap->a_cnp;
struct vnode **vpp = ap->a_vpp;
struct vnode *dvp = ap->a_dvp;
char *pname = cnp->cn_nameptr;
struct portalnode *pt;
int error;
struct vnode *fvp = 0;
char *path;
int size;
*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);
}
KASSERT((cnp->cn_flags & ISDOTDOT) == 0,
("portal_lookup: Can not handle dotdot lookups."));
/*
* Do the MALLOC before the getnewvnode since doing so afterward
* might cause a bogus v_data pointer to get dereferenced
* elsewhere if MALLOC should block.
*/
pt = malloc(sizeof(struct portalnode),
M_TEMP, M_WAITOK);
error = getnewvnode("portal", dvp->v_mount, &portal_vnodeops, &fvp);
if (error) {
free(pt, M_TEMP);
goto bad;
}
fvp->v_type = VREG;
fvp->v_data = pt;
/*
* Save all of the remaining pathname and
* advance the namei next pointer to the end
* of the string.
*/
for (size = 0, path = pname; *path; path++)
size++;
cnp->cn_consume = size - cnp->cn_namelen;
pt->pt_arg = malloc(size+1, M_TEMP, M_WAITOK);
pt->pt_size = size+1;
bcopy(pname, pt->pt_arg, pt->pt_size);
pt->pt_fileid = portal_fileid++;
*vpp = fvp;
vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY);
error = insmntque(fvp, dvp->v_mount);
if (error != 0) {
*vpp = NULLVP;
return (error);
}
return (0);
bad:;
if (fvp)
vrele(fvp);
return (error);
}
static int
portal_connect(so, so2)
struct socket *so;
struct socket *so2;
{
/* from unp_connect, bypassing the namei stuff... */
struct socket *so3;
struct unpcb *unp2;
struct unpcb *unp3;
if (so2 == 0)
return (ECONNREFUSED);
if (so->so_type != so2->so_type)
return (EPROTOTYPE);
if ((so2->so_options & SO_ACCEPTCONN) == 0)
return (ECONNREFUSED);
CURVNET_SET(so2->so_vnet);
if ((so3 = sonewconn(so2, 0)) == 0) {
CURVNET_RESTORE();
return (ECONNREFUSED);
}
CURVNET_RESTORE();
unp2 = sotounpcb(so2);
unp3 = sotounpcb(so3);
if (unp2->unp_addr)
unp3->unp_addr = (struct sockaddr_un *)
sodupsockaddr((struct sockaddr *)unp2->unp_addr,
M_NOWAIT);
so2 = so3;
return (soconnect2(so, so2));
}
static int
portal_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct thread *a_td;
} */ *ap;
{
struct socket *so = 0;
struct portalnode *pt;
struct thread *td = ap->a_td;
struct vnode *vp = ap->a_vp;
struct uio auio;
struct iovec aiov[2];
int res;
struct mbuf *cm = 0;
struct cmsghdr *cmsg;
int newfds;
int *ip;
int fd;
int error;
int len;
struct portalmount *fmp;
struct file *fp;
struct portal_cred pcred;
#ifdef CAPABILITY_MODE
/*
* This may require access to a global namespace (e.g. an IP address);
* disallow it entirely, as we do open(2).
*/
if (IN_CAPABILITY_MODE(td)) {
#ifdef KTRACE
if (KTRPOINT(td, KTR_CAPFAIL))
ktrcapfail(CAPFAIL_SYSCALL, 0, 0);
#endif
return (ECAPMODE);
}
#endif
/*
* Nothing to do when opening the root node.
*/
if (vp->v_vflag & VV_ROOT)
return (0);
/*
* Can't be opened unless the caller is set up
* to deal with the side effects. Check for this
* by testing whether td_dupfd has been set.
*/
if (td->td_dupfd >= 0)
return (ENODEV);
pt = VTOPORTAL(vp);
fmp = VFSTOPORTAL(vp->v_mount);
/*
* Create a new socket.
*/
error = socreate(AF_UNIX, &so, SOCK_STREAM, 0, ap->a_cred,
ap->a_td);
if (error)
goto bad;
/*
* Reserve some buffer space
*/
res = pt->pt_size + sizeof(pcred) + 512; /* XXX */
error = soreserve(so, res, res);
if (error)
goto bad;
/*
* Kick off connection
*/
error = portal_connect(so, fmp->pm_server->f_data);
if (error)
goto bad;
/*
* Wait for connection to complete
*/
/*
* XXX: Since the mount point is holding a reference on the
* underlying server socket, it is not easy to find out whether
* the server process is still running. To handle this problem
* we loop waiting for the new socket to be connected (something
* which will only happen if the server is still running) or for
* the reference count on the server socket to drop to 1, which
* will happen if the server dies. Sleep for 5 second intervals
* and keep polling the reference count. XXX.
*/
SOCK_LOCK(so);
while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
if (fmp->pm_server->f_count == 1) {
SOCK_UNLOCK(so);
error = ECONNREFUSED;
goto bad;
}
(void) msleep((caddr_t) &so->so_timeo, SOCK_MTX(so), PSOCK,
"portalcon", 5 * hz);
}
SOCK_UNLOCK(so);
if (so->so_error) {
error = so->so_error;
goto bad;
}
/*
* Set miscellaneous flags
*/
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_timeo = 0;
so->so_rcv.sb_flags |= SB_NOINTR;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_timeo = 0;
so->so_snd.sb_flags |= SB_NOINTR;
SOCKBUF_UNLOCK(&so->so_snd);
pcred.pcr_flag = ap->a_mode;
pcred.pcr_uid = ap->a_cred->cr_uid;
pcred.pcr_ngroups = MIN(ap->a_cred->cr_ngroups, XU_NGROUPS);
bcopy(ap->a_cred->cr_groups, pcred.pcr_groups,
pcred.pcr_ngroups * sizeof(gid_t));
aiov[0].iov_base = (caddr_t) &pcred;
aiov[0].iov_len = sizeof(pcred);
aiov[1].iov_base = pt->pt_arg;
aiov[1].iov_len = pt->pt_size;
auio.uio_iov = aiov;
auio.uio_iovcnt = 2;
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_td = td;
auio.uio_offset = 0;
auio.uio_resid = aiov[0].iov_len + aiov[1].iov_len;
error = sosend(so, (struct sockaddr *) 0, &auio,
(struct mbuf *) 0, (struct mbuf *) 0, 0 , td);
if (error)
goto bad;
len = auio.uio_resid = sizeof(int);
do {
struct mbuf *m = 0;
int flags = MSG_WAITALL;
error = soreceive(so, (struct sockaddr **) 0, &auio,
&m, &cm, &flags);
if (error)
goto bad;
/*
* Grab an error code from the mbuf.
*/
if (m) {
m = m_pullup(m, sizeof(int)); /* Needed? */
if (m) {
error = *(mtod(m, int *));
m_freem(m);
} else {
error = EINVAL;
}
} else {
if (cm == 0) {
error = ECONNRESET; /* XXX */
#ifdef notdef
break;
#endif
}
}
} while (cm == 0 && auio.uio_resid == len && !error);
if (cm == 0)
goto bad;
if (auio.uio_resid) {
error = 0;
#ifdef notdef
error = EMSGSIZE;
goto bad;
#endif
}
/*
* XXX: Break apart the control message, and retrieve the
* received file descriptor. Note that more than one descriptor
* may have been received, or that the rights chain may have more
* than a single mbuf in it. What to do?
*/
cmsg = mtod(cm, struct cmsghdr *);
newfds = (cmsg->cmsg_len - sizeof(*cmsg)) / sizeof (int);
if (newfds == 0) {
error = ECONNREFUSED;
goto bad;
}
/*
* At this point the rights message consists of a control message
* header, followed by a data region containing a vector of
* integer file descriptors. The fds were allocated by the action
* of receiving the control message.
*/
ip = (int *) (cmsg + 1);
fd = *ip++;
if (newfds > 1) {
/*
* Close extra fds.
*/
int i;
printf("portal_open: %d extra fds\n", newfds - 1);
for (i = 1; i < newfds; i++) {
portal_closefd(td, *ip);
ip++;
}
}
/*
* Check that the mode the file is being opened for is a subset
* of the mode of the existing descriptor.
*/
if ((error = fget(td, fd, 0, &fp)) != 0)
goto bad;
if (((ap->a_mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
fdrop(fp, td);
portal_closefd(td, fd);
error = EACCES;
goto bad;
}
fdrop(fp, td);
/*
* Save the dup fd in the proc structure then return the
* special error code (ENXIO) which causes magic things to
* happen in vn_open. The whole concept is, well, hmmm.
*/
td->td_dupfd = fd;
error = ENXIO;
bad:;
/*
* And discard the control message.
*/
if (cm) {
m_freem(cm);
}
if (so) {
soshutdown(so, 2);
soclose(so);
}
return (error);
}
static int
portal_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_size = DEV_BSIZE;
vap->va_blocksize = DEV_BSIZE;
nanotime(&vap->va_atime);
vap->va_mtime = vap->va_atime;
vap->va_ctime = vap->va_mtime;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_rdev = NODEV;
/* vap->va_qbytes = 0; */
vap->va_bytes = 0;
vap->va_filerev = 0;
/* vap->va_qsize = 0; */
if (vp->v_vflag & VV_ROOT) {
vap->va_type = VDIR;
vap->va_mode = S_IRUSR|S_IWUSR|S_IXUSR|
S_IRGRP|S_IWGRP|S_IXGRP|
S_IROTH|S_IWOTH|S_IXOTH;
vap->va_nlink = 2;
vap->va_fileid = 2;
} else {
vap->va_type = VREG;
vap->va_mode = S_IRUSR|S_IWUSR|
S_IRGRP|S_IWGRP|
S_IROTH|S_IWOTH;
vap->va_nlink = 1;
vap->va_fileid = VTOPORTAL(vp)->pt_fileid;
}
return (0);
}
static int
portal_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
} */ *ap;
{
/*
* Can't mess with the root vnode
*/
if (ap->a_vp->v_vflag & VV_ROOT)
return (EACCES);
if (ap->a_vap->va_flags != VNOVAL)
return (EOPNOTSUPP);
return (0);
}
/*
* Fake readdir, just return empty directory.
* It is hard to deal with '.' and '..' so don't bother.
*/
static int
portal_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
u_long *a_cookies;
int a_ncookies;
} */ *ap;
{
/*
* We don't allow exporting portal mounts, and currently local
* requests do not need cookies.
*/
if (ap->a_ncookies)
panic("portal_readdir: not hungry");
return (0);
}
static int
portal_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct portalnode *pt = VTOPORTAL(ap->a_vp);
if (pt->pt_arg) {
free((caddr_t) pt->pt_arg, M_TEMP);
pt->pt_arg = 0;
}
free(ap->a_vp->v_data, M_TEMP);
ap->a_vp->v_data = 0;
return (0);
}
struct vop_vector portal_vnodeops = {
.vop_default = &default_vnodeops,
.vop_access = VOP_NULL,
.vop_getattr = portal_getattr,
.vop_lookup = portal_lookup,
.vop_open = portal_open,
.vop_pathconf = vop_stdpathconf,
.vop_readdir = portal_readdir,
.vop_reclaim = portal_reclaim,
.vop_setattr = portal_setattr,
};