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139233cbd6
freebsd/sys/kern/uipc_usrreq.c
Robert Watson a34b704666 Merge next step in socket buffer locking: 
- sowakeup() now asserts the socket buffer lock on entry.  Move
  the call to KNOTE higher in sowakeup() so that it is made with
  the socket buffer lock held for consistency with other calls.
  Release the socket buffer lock prior to calling into pgsigio(),
  so_upcall(), or aio_swake().  Locking for this event management
  will need revisiting in the future, but this model avoids lock
  order reversals when upcalls into other subsystems result in
  socket/socket buffer operations.  Assert that the socket buffer
  lock is not held at the end of the function.

- Wrapper macros for sowakeup(), sorwakeup() and sowwakeup(), now
  have _locked versions which assert the socket buffer lock on
  entry.  If a wakeup is required by sb_notify(), invoke
  sowakeup(); otherwise, unconditionally release the socket buffer
  lock.  This results in the socket buffer lock being released
  whether a wakeup is required or not.

- Break out socantsendmore() into socantsendmore_locked() that
  asserts the socket buffer lock.  socantsendmore()
  unconditionally locks the socket buffer before calling
  socantsendmore_locked().  Note that both functions return with
  the socket buffer unlocked as socantsendmore_locked() calls
  sowwakeup_locked() which has the same properties.  Assert that
  the socket buffer is unlocked on return.

- Break out socantrcvmore() into socantrcvmore_locked() that
  asserts the socket buffer lock.  socantrcvmore() unconditionally
  locks the socket buffer before calling socantrcvmore_locked().
  Note that both functions return with the socket buffer unlocked
  as socantrcvmore_locked() calls sorwakeup_locked() which has
  similar properties.  Assert that the socket buffer is unlocked
  on return.

- Break out sbrelease() into a sbrelease_locked() that asserts the
  socket buffer lock.  sbrelease() unconditionally locks the
  socket buffer before calling sbrelease_locked().
  sbrelease_locked() now invokes sbflush_locked() instead of
  sbflush().

- Assert the socket buffer lock in socket buffer sanity check
  functions sblastrecordchk(), sblastmbufchk().

- Assert the socket buffer lock in SBLINKRECORD().

- Break out various sbappend() functions into sbappend_locked()
  (and variations on that name) that assert the socket buffer
  lock.  The !_locked() variations unconditionally lock the socket
  buffer before calling their _locked counterparts.  Internally,
  make sure to call _locked() support routines, etc, if already
  holding the socket buffer lock.

- Break out sbinsertoob() into sbinsertoob_locked() that asserts
  the socket buffer lock.  sbinsertoob() unconditionally locks the
  socket buffer before calling sbinsertoob_locked().

- Break out sbflush() into sbflush_locked() that asserts the
  socket buffer lock.  sbflush() unconditionally locks the socket
  buffer before calling sbflush_locked().  Update panic strings
  for new function names.

- Break out sbdrop() into sbdrop_locked() that asserts the socket
  buffer lock.  sbdrop() unconditionally locks the socket buffer
  before calling sbdrop_locked().

- Break out sbdroprecord() into sbdroprecord_locked() that asserts
  the socket buffer lock.  sbdroprecord() unconditionally locks
  the socket buffer before calling sbdroprecord_locked().

- sofree() now calls socantsendmore_locked() and re-acquires the
  socket buffer lock on return.  It also now calls
  sbrelease_locked().

- sorflush() now calls socantrcvmore_locked() and re-acquires the
  socket buffer lock on return.  Clean up/mess up other behavior
  in sorflush() relating to the temporary stack copy of the socket
  buffer used with dom_dispose by more properly initializing the
  temporary copy, and selectively bzeroing/copying more carefully
  to prevent WITNESS from getting confused by improperly
  initialized mutexes.  Annotate why that's necessary, or at
  least, needed.

- soisconnected() now calls sbdrop_locked() before unlocking the
  socket buffer to avoid locking overhead.

Some parts of this change were:

Submitted by:	sam
Sponsored by:	FreeBSD Foundation
Obtained from:	BSD/OS
2004-06-21 00:20:43 +00:00

1683 lines
39 KiB
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/*
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/domain.h>
#include <sys/fcntl.h>
#include <sys/malloc.h> /* XXX must be before <sys/file.h> */
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mac.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/resourcevar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/vnode.h>
#include <vm/uma.h>
static uma_zone_t unp_zone;
static unp_gen_t unp_gencnt;
static u_int unp_count;
static struct unp_head unp_shead, unp_dhead;
/*
* Unix communications domain.
*
* TODO:
* SEQPACKET, RDM
* rethink name space problems
* need a proper out-of-band
* lock pushdown
*/
static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
static ino_t unp_ino; /* prototype for fake inode numbers */
static struct mtx unp_mtx;
#define UNP_LOCK_INIT() \
mtx_init(&unp_mtx, "unp", NULL, MTX_DEF)
#define UNP_LOCK() mtx_lock(&unp_mtx)
#define UNP_UNLOCK() mtx_unlock(&unp_mtx)
#define UNP_LOCK_ASSERT() mtx_assert(&unp_mtx, MA_OWNED)
static int unp_attach(struct socket *);
static void unp_detach(struct unpcb *);
static int unp_bind(struct unpcb *,struct sockaddr *, struct thread *);
static int unp_connect(struct socket *,struct sockaddr *, struct thread *);
static int unp_connect2(struct socket *so, struct socket *so2);
static void unp_disconnect(struct unpcb *);
static void unp_shutdown(struct unpcb *);
static void unp_drop(struct unpcb *, int);
static void unp_gc(void);
static void unp_scan(struct mbuf *, void (*)(struct file *));
static void unp_mark(struct file *);
static void unp_discard(struct file *);
static void unp_freerights(struct file **, int);
static int unp_internalize(struct mbuf **, struct thread *);
static int unp_listen(struct unpcb *, struct thread *);
static int
uipc_abort(struct socket *so)
{
struct unpcb *unp = sotounpcb(so);
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
unp_drop(unp, ECONNABORTED);
unp_detach(unp); /* NB: unlocks */
SOCK_LOCK(so);
sotryfree(so);
return (0);
}
static int
uipc_accept(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp = sotounpcb(so);
const struct sockaddr *sa;
if (unp == NULL)
return (EINVAL);
/*
* Pass back name of connected socket,
* if it was bound and we are still connected
* (our peer may have closed already!).
*/
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_LOCK();
if (unp->unp_conn != NULL && unp->unp_conn->unp_addr != NULL)
sa = (struct sockaddr *) unp->unp_conn->unp_addr;
else
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
UNP_UNLOCK();
return (0);
}
static int
uipc_attach(struct socket *so, int proto, struct thread *td)
{
struct unpcb *unp = sotounpcb(so);
if (unp != NULL)
return (EISCONN);
return (unp_attach(so));
}
static int
uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct unpcb *unp = sotounpcb(so);
if (unp == NULL)
return (EINVAL);
return (unp_bind(unp, nam, td));
}
static int
uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct unpcb *unp = sotounpcb(so);
int error;
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
error = unp_connect(so, nam, curthread);
UNP_UNLOCK();
return (error);
}
int
uipc_connect2(struct socket *so1, struct socket *so2)
{
struct unpcb *unp = sotounpcb(so1);
int error;
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
error = unp_connect2(so1, so2);
UNP_UNLOCK();
return (error);
}
/* control is EOPNOTSUPP */
static int
uipc_detach(struct socket *so)
{
struct unpcb *unp = sotounpcb(so);
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
unp_detach(unp); /* NB: unlocks unp */
return (0);
}
static int
uipc_disconnect(struct socket *so)
{
struct unpcb *unp = sotounpcb(so);
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
unp_disconnect(unp);
UNP_UNLOCK();
return (0);
}
static int
uipc_listen(struct socket *so, struct thread *td)
{
struct unpcb *unp = sotounpcb(so);
int error;
if (unp == NULL || unp->unp_vnode == NULL)
return (EINVAL);
UNP_LOCK();
error = unp_listen(unp, td);
UNP_UNLOCK();
return (error);
}
static int
uipc_peeraddr(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp = sotounpcb(so);
const struct sockaddr *sa;
if (unp == NULL)
return (EINVAL);
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_LOCK();
if (unp->unp_conn != NULL && unp->unp_conn->unp_addr!= NULL)
sa = (struct sockaddr *) unp->unp_conn->unp_addr;
else {
/*
* XXX: It seems that this test always fails even when
* connection is established. So, this else clause is
* added as workaround to return PF_LOCAL sockaddr.
*/
sa = &sun_noname;
}
bcopy(sa, *nam, sa->sa_len);
UNP_UNLOCK();
return (0);
}
static int
uipc_rcvd(struct socket *so, int flags)
{
struct unpcb *unp = sotounpcb(so);
struct socket *so2;
u_long newhiwat;
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
switch (so->so_type) {
case SOCK_DGRAM:
panic("uipc_rcvd DGRAM?");
/*NOTREACHED*/
case SOCK_STREAM:
if (unp->unp_conn == NULL)
break;
so2 = unp->unp_conn->unp_socket;
SOCKBUF_LOCK(&so2->so_snd);
SOCKBUF_LOCK(&so->so_rcv);
/*
* Adjust backpressure on sender
* and wakeup any waiting to write.
*/
so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt;
unp->unp_mbcnt = so->so_rcv.sb_mbcnt;
newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc -
so->so_rcv.sb_cc;
(void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
newhiwat, RLIM_INFINITY);
unp->unp_cc = so->so_rcv.sb_cc;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_UNLOCK(&so2->so_snd);
sowwakeup(so2);
break;
default:
panic("uipc_rcvd unknown socktype");
}
UNP_UNLOCK();
return (0);
}
/* pru_rcvoob is EOPNOTSUPP */
static int
uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
struct mbuf *control, struct thread *td)
{
int error = 0;
struct unpcb *unp = sotounpcb(so);
struct socket *so2;
u_long newhiwat;
if (unp == NULL) {
error = EINVAL;
goto release;
}
if (flags & PRUS_OOB) {
error = EOPNOTSUPP;
goto release;
}
if (control != NULL && (error = unp_internalize(&control, td)))
goto release;
UNP_LOCK();
switch (so->so_type) {
case SOCK_DGRAM:
{
const struct sockaddr *from;
if (nam != NULL) {
if (unp->unp_conn != NULL) {
error = EISCONN;
break;
}
error = unp_connect(so, nam, td);
if (error)
break;
} else {
if (unp->unp_conn == NULL) {
error = ENOTCONN;
break;
}
}
so2 = unp->unp_conn->unp_socket;
if (unp->unp_addr != NULL)
from = (struct sockaddr *)unp->unp_addr;
else
from = &sun_noname;
SOCKBUF_LOCK(&so2->so_rcv);
if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
SOCKBUF_UNLOCK(&so2->so_rcv);
sorwakeup(so2);
m = NULL;
control = NULL;
} else {
SOCKBUF_UNLOCK(&so2->so_rcv);
error = ENOBUFS;
}
if (nam != NULL)
unp_disconnect(unp);
break;
}
case SOCK_STREAM:
/* Connect if not connected yet. */
/*
* Note: A better implementation would complain
* if not equal to the peer's address.
*/
if ((so->so_state & SS_ISCONNECTED) == 0) {
if (nam != NULL) {
error = unp_connect(so, nam, td);
if (error)
break; /* XXX */
} else {
error = ENOTCONN;
break;
}
}
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
error = EPIPE;
break;
}
if (unp->unp_conn == NULL)
panic("uipc_send connected but no connection?");
so2 = unp->unp_conn->unp_socket;
SOCKBUF_LOCK(&so2->so_rcv);
/*
* Send to paired receive port, and then reduce
* send buffer hiwater marks to maintain backpressure.
* Wake up readers.
*/
if (control != NULL) {
if (sbappendcontrol_locked(&so2->so_rcv, m, control))
control = NULL;
} else {
sbappend_locked(&so2->so_rcv, m);
}
so->so_snd.sb_mbmax -=
so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt;
unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt;
newhiwat = so->so_snd.sb_hiwat -
(so2->so_rcv.sb_cc - unp->unp_conn->unp_cc);
(void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
newhiwat, RLIM_INFINITY);
unp->unp_conn->unp_cc = so2->so_rcv.sb_cc;
SOCKBUF_UNLOCK(&so2->so_rcv);
sorwakeup(so2);
m = NULL;
break;
default:
panic("uipc_send unknown socktype");
}
/*
* SEND_EOF is equivalent to a SEND followed by
* a SHUTDOWN.
*/
if (flags & PRUS_EOF) {
socantsendmore(so);
unp_shutdown(unp);
}
UNP_UNLOCK();
if (control != NULL && error != 0)
unp_dispose(control);
release:
if (control != NULL)
m_freem(control);
if (m != NULL)
m_freem(m);
return (error);
}
static int
uipc_sense(struct socket *so, struct stat *sb)
{
struct unpcb *unp = sotounpcb(so);
struct socket *so2;
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
sb->st_blksize = so->so_snd.sb_hiwat;
if (so->so_type == SOCK_STREAM && unp->unp_conn != NULL) {
so2 = unp->unp_conn->unp_socket;
sb->st_blksize += so2->so_rcv.sb_cc;
}
sb->st_dev = NODEV;
if (unp->unp_ino == 0)
unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
sb->st_ino = unp->unp_ino;
UNP_UNLOCK();
return (0);
}
static int
uipc_shutdown(struct socket *so)
{
struct unpcb *unp = sotounpcb(so);
if (unp == NULL)
return (EINVAL);
UNP_LOCK();
socantsendmore(so);
unp_shutdown(unp);
UNP_UNLOCK();
return (0);
}
static int
uipc_sockaddr(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp = sotounpcb(so);
const struct sockaddr *sa;
if (unp == NULL)
return (EINVAL);
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_LOCK();
if (unp->unp_addr != NULL)
sa = (struct sockaddr *) unp->unp_addr;
else
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
UNP_UNLOCK();
return (0);
}
struct pr_usrreqs uipc_usrreqs = {
uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect,
uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect,
uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp,
uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr,
sosend, soreceive, sopoll, pru_sosetlabel_null
};
int
uipc_ctloutput(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
struct unpcb *unp = sotounpcb(so);
struct xucred xu;
int error;
switch (sopt->sopt_dir) {
case SOPT_GET:
switch (sopt->sopt_name) {
case LOCAL_PEERCRED:
error = 0;
UNP_LOCK();
if (unp->unp_flags & UNP_HAVEPC)
xu = unp->unp_peercred;
else {
if (so->so_type == SOCK_STREAM)
error = ENOTCONN;
else
error = EINVAL;
}
UNP_UNLOCK();
if (error == 0)
error = sooptcopyout(sopt, &xu, sizeof(xu));
break;
default:
error = EOPNOTSUPP;
break;
}
break;
case SOPT_SET:
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
/*
* Both send and receive buffers are allocated PIPSIZ bytes of buffering
* for stream sockets, although the total for sender and receiver is
* actually only PIPSIZ.
* Datagram sockets really use the sendspace as the maximum datagram size,
* and don't really want to reserve the sendspace. Their recvspace should
* be large enough for at least one max-size datagram plus address.
*/
#ifndef PIPSIZ
#define PIPSIZ 8192
#endif
static u_long unpst_sendspace = PIPSIZ;
static u_long unpst_recvspace = PIPSIZ;
static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
static u_long unpdg_recvspace = 4*1024;
static int unp_rights; /* file descriptors in flight */
SYSCTL_DECL(_net_local_stream);
SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
&unpst_sendspace, 0, "");
SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
&unpst_recvspace, 0, "");
SYSCTL_DECL(_net_local_dgram);
SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
&unpdg_sendspace, 0, "");
SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
&unpdg_recvspace, 0, "");
SYSCTL_DECL(_net_local);
SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
static int
unp_attach(so)
struct socket *so;
{
register struct unpcb *unp;
int error;
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
switch (so->so_type) {
case SOCK_STREAM:
error = soreserve(so, unpst_sendspace, unpst_recvspace);
break;
case SOCK_DGRAM:
error = soreserve(so, unpdg_sendspace, unpdg_recvspace);
break;
default:
panic("unp_attach");
}
if (error)
return (error);
}
unp = uma_zalloc(unp_zone, M_WAITOK);
if (unp == NULL)
return (ENOBUFS);
bzero(unp, sizeof *unp);
LIST_INIT(&unp->unp_refs);
unp->unp_socket = so;
UNP_LOCK();
unp->unp_gencnt = ++unp_gencnt;
unp_count++;
LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
: &unp_shead, unp, unp_link);
UNP_UNLOCK();
so->so_pcb = unp;
return (0);
}
static void
unp_detach(unp)
register struct unpcb *unp;
{
struct vnode *vp;
UNP_LOCK_ASSERT();
LIST_REMOVE(unp, unp_link);
unp->unp_gencnt = ++unp_gencnt;
--unp_count;
if ((vp = unp->unp_vnode) != NULL) {
/*
* XXXRW: should v_socket be frobbed only while holding
* Giant?
*/
unp->unp_vnode->v_socket = NULL;
unp->unp_vnode = NULL;
}
if (unp->unp_conn != NULL)
unp_disconnect(unp);
while (!LIST_EMPTY(&unp->unp_refs)) {
struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
unp_drop(ref, ECONNRESET);
}
soisdisconnected(unp->unp_socket);
unp->unp_socket->so_pcb = NULL;
if (unp_rights) {
/*
* Normally the receive buffer is flushed later,
* in sofree, but if our receive buffer holds references
* to descriptors that are now garbage, we will dispose
* of those descriptor references after the garbage collector
* gets them (resulting in a "panic: closef: count < 0").
*/
sorflush(unp->unp_socket);
unp_gc();
}
if (unp->unp_addr != NULL)
FREE(unp->unp_addr, M_SONAME);
UNP_UNLOCK();
uma_zfree(unp_zone, unp);
if (vp) {
mtx_lock(&Giant);
vrele(vp);
mtx_unlock(&Giant);
}
}
static int
unp_bind(unp, nam, td)
struct unpcb *unp;
struct sockaddr *nam;
struct thread *td;
{
struct sockaddr_un *soun = (struct sockaddr_un *)nam;
struct vnode *vp;
struct mount *mp;
struct vattr vattr;
int error, namelen;
struct nameidata nd;
char *buf;
/*
* XXXRW: This test-and-set of unp_vnode is non-atomic; the
* unlocked read here is fine, but the value of unp_vnode needs
* to be tested again after we do all the lookups to see if the
* pcb is still unbound?
*/
if (unp->unp_vnode != NULL)
return (EINVAL);
namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
if (namelen <= 0)
return (EINVAL);
buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
strlcpy(buf, soun->sun_path, namelen + 1);
mtx_lock(&Giant);
restart:
mtx_assert(&Giant, MA_OWNED);
NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME, UIO_SYSSPACE,
buf, td);
/* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
error = namei(&nd);
if (error)
goto done;
vp = nd.ni_vp;
if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
NDFREE(&nd, NDF_ONLY_PNBUF);
if (nd.ni_dvp == vp)
vrele(nd.ni_dvp);
else
vput(nd.ni_dvp);
if (vp != NULL) {
vrele(vp);
error = EADDRINUSE;
goto done;
}
error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
if (error)
goto done;
goto restart;
}
VATTR_NULL(&vattr);
vattr.va_type = VSOCK;
vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
#ifdef MAC
error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
&vattr);
#endif
if (error == 0) {
VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE);
error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
vput(nd.ni_dvp);
if (error)
goto done;
vp = nd.ni_vp;
ASSERT_VOP_LOCKED(vp, "unp_bind");
soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
UNP_LOCK();
vp->v_socket = unp->unp_socket;
unp->unp_vnode = vp;
unp->unp_addr = soun;
UNP_UNLOCK();
VOP_UNLOCK(vp, 0, td);
vn_finished_write(mp);
done:
mtx_unlock(&Giant);
free(buf, M_TEMP);
return (error);
}
static int
unp_connect(so, nam, td)
struct socket *so;
struct sockaddr *nam;
struct thread *td;
{
register struct sockaddr_un *soun = (struct sockaddr_un *)nam;
register struct vnode *vp;
register struct socket *so2, *so3;
struct unpcb *unp = sotounpcb(so);
struct unpcb *unp2, *unp3;
int error, len;
struct nameidata nd;
char buf[SOCK_MAXADDRLEN];
struct sockaddr *sa;
UNP_LOCK_ASSERT();
len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
if (len <= 0)
return (EINVAL);
strlcpy(buf, soun->sun_path, len + 1);
UNP_UNLOCK();
sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
mtx_lock(&Giant);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, td);
error = namei(&nd);
if (error)
vp = NULL;
else
vp = nd.ni_vp;
ASSERT_VOP_LOCKED(vp, "unp_connect");
NDFREE(&nd, NDF_ONLY_PNBUF);
if (error)
goto bad;
if (vp->v_type != VSOCK) {
error = ENOTSOCK;
goto bad;
}
error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
if (error)
goto bad;
so2 = vp->v_socket;
if (so2 == NULL) {
error = ECONNREFUSED;
goto bad;
}
if (so->so_type != so2->so_type) {
error = EPROTOTYPE;
goto bad;
}
mtx_unlock(&Giant);
UNP_LOCK();
if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
if (so2->so_options & SO_ACCEPTCONN) {
/*
* NB: drop locks here so unp_attach is entered
* w/o locks; this avoids a recursive lock
* of the head and holding sleep locks across
* a (potentially) blocking malloc.
*/
UNP_UNLOCK();
so3 = sonewconn(so2, 0);
UNP_LOCK();
} else
so3 = NULL;
if (so3 == NULL) {
error = ECONNREFUSED;
goto bad2;
}
unp = sotounpcb(so);
unp2 = sotounpcb(so2);
unp3 = sotounpcb(so3);
if (unp2->unp_addr != NULL) {
bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
unp3->unp_addr = (struct sockaddr_un *) sa;
sa = NULL;
}
/*
* unp_peercred management:
*
* The connecter's (client's) credentials are copied
* from its process structure at the time of connect()
* (which is now).
*/
cru2x(td->td_ucred, &unp3->unp_peercred);
unp3->unp_flags |= UNP_HAVEPC;
/*
* The receiver's (server's) credentials are copied
* from the unp_peercred member of socket on which the
* former called listen(); unp_listen() cached that
* process's credentials at that time so we can use
* them now.
*/
KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
("unp_connect: listener without cached peercred"));
memcpy(&unp->unp_peercred, &unp2->unp_peercred,
sizeof(unp->unp_peercred));
unp->unp_flags |= UNP_HAVEPC;
#ifdef MAC
SOCK_LOCK(so);
mac_set_socket_peer_from_socket(so, so3);
mac_set_socket_peer_from_socket(so3, so);
SOCK_UNLOCK(so);
#endif
so2 = so3;
}
error = unp_connect2(so, so2);
bad2:
UNP_UNLOCK();
mtx_lock(&Giant);
bad:
mtx_assert(&Giant, MA_OWNED);
if (vp != NULL)
vput(vp);
mtx_unlock(&Giant);
free(sa, M_SONAME);
UNP_LOCK();
return (error);
}
static int
unp_connect2(so, so2)
register struct socket *so;
register struct socket *so2;
{
register struct unpcb *unp = sotounpcb(so);
register struct unpcb *unp2;
UNP_LOCK_ASSERT();
if (so2->so_type != so->so_type)
return (EPROTOTYPE);
unp2 = sotounpcb(so2);
unp->unp_conn = unp2;
switch (so->so_type) {
case SOCK_DGRAM:
LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
soisconnected(so);
break;
case SOCK_STREAM:
unp2->unp_conn = unp;
soisconnected(so);
soisconnected(so2);
break;
default:
panic("unp_connect2");
}
return (0);
}
static void
unp_disconnect(unp)
struct unpcb *unp;
{
register struct unpcb *unp2 = unp->unp_conn;
struct socket *so;
UNP_LOCK_ASSERT();
if (unp2 == NULL)
return;
unp->unp_conn = NULL;
switch (unp->unp_socket->so_type) {
case SOCK_DGRAM:
LIST_REMOVE(unp, unp_reflink);
so = unp->unp_socket;
SOCK_LOCK(so);
so->so_state &= ~SS_ISCONNECTED;
SOCK_UNLOCK(so);
break;
case SOCK_STREAM:
soisdisconnected(unp->unp_socket);
unp2->unp_conn = NULL;
soisdisconnected(unp2->unp_socket);
break;
}
}
#ifdef notdef
void
unp_abort(unp)
struct unpcb *unp;
{
unp_detach(unp);
}
#endif
/*
* unp_pcblist() assumes that UNIX domain socket memory is never reclaimed
* by the zone (UMA_ZONE_NOFREE), and as such potentially stale pointers
* are safe to reference. It first scans the list of struct unpcb's to
* generate a pointer list, then it rescans its list one entry at a time to
* externalize and copyout. It checks the generation number to see if a
* struct unpcb has been reused, and will skip it if so.
*/
static int
unp_pcblist(SYSCTL_HANDLER_ARGS)
{
int error, i, n;
struct unpcb *unp, **unp_list;
unp_gen_t gencnt;
struct xunpgen *xug;
struct unp_head *head;
struct xunpcb *xu;
head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
/*
* The process of preparing the PCB list is too time-consuming and
* resource-intensive to repeat twice on every request.
*/
if (req->oldptr == NULL) {
n = unp_count;
req->oldidx = 2 * (sizeof *xug)
+ (n + n/8) * sizeof(struct xunpcb);
return (0);
}
if (req->newptr != NULL)
return (EPERM);
/*
* OK, now we're committed to doing something.
*/
xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
UNP_LOCK();
gencnt = unp_gencnt;
n = unp_count;
UNP_UNLOCK();
xug->xug_len = sizeof *xug;
xug->xug_count = n;
xug->xug_gen = gencnt;
xug->xug_sogen = so_gencnt;
error = SYSCTL_OUT(req, xug, sizeof *xug);
if (error) {
free(xug, M_TEMP);
return (error);
}
unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
UNP_LOCK();
for (unp = LIST_FIRST(head), i = 0; unp && i < n;
unp = LIST_NEXT(unp, unp_link)) {
if (unp->unp_gencnt <= gencnt) {
if (cr_cansee(req->td->td_ucred,
unp->unp_socket->so_cred))
continue;
unp_list[i++] = unp;
}
}
UNP_UNLOCK();
n = i; /* in case we lost some during malloc */
error = 0;
xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK);
for (i = 0; i < n; i++) {
unp = unp_list[i];
if (unp->unp_gencnt <= gencnt) {
xu->xu_len = sizeof *xu;
xu->xu_unpp = unp;
/*
* XXX - need more locking here to protect against
* connect/disconnect races for SMP.
*/
if (unp->unp_addr != NULL)
bcopy(unp->unp_addr, &xu->xu_addr,
unp->unp_addr->sun_len);
if (unp->unp_conn != NULL &&
unp->unp_conn->unp_addr != NULL)
bcopy(unp->unp_conn->unp_addr,
&xu->xu_caddr,
unp->unp_conn->unp_addr->sun_len);
bcopy(unp, &xu->xu_unp, sizeof *unp);
sotoxsocket(unp->unp_socket, &xu->xu_socket);
error = SYSCTL_OUT(req, xu, sizeof *xu);
}
}
free(xu, M_TEMP);
if (!error) {
/*
* Give the user an updated idea of our state.
* If the generation differs from what we told
* her before, she knows that something happened
* while we were processing this request, and it
* might be necessary to retry.
*/
xug->xug_gen = unp_gencnt;
xug->xug_sogen = so_gencnt;
xug->xug_count = unp_count;
error = SYSCTL_OUT(req, xug, sizeof *xug);
}
free(unp_list, M_TEMP);
free(xug, M_TEMP);
return (error);
}
SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
(caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
"List of active local datagram sockets");
SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
(caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
"List of active local stream sockets");
static void
unp_shutdown(unp)
struct unpcb *unp;
{
struct socket *so;
UNP_LOCK_ASSERT();
if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
(so = unp->unp_conn->unp_socket))
socantrcvmore(so);
}
static void
unp_drop(unp, errno)
struct unpcb *unp;
int errno;
{
struct socket *so = unp->unp_socket;
UNP_LOCK_ASSERT();
so->so_error = errno;
unp_disconnect(unp);
}
#ifdef notdef
void
unp_drain()
{
}
#endif
static void
unp_freerights(rp, fdcount)
struct file **rp;
int fdcount;
{
int i;
struct file *fp;
for (i = 0; i < fdcount; i++) {
fp = *rp;
/*
* zero the pointer before calling
* unp_discard since it may end up
* in unp_gc()..
*/
*rp++ = 0;
unp_discard(fp);
}
}
int
unp_externalize(control, controlp)
struct mbuf *control, **controlp;
{
struct thread *td = curthread; /* XXX */
struct cmsghdr *cm = mtod(control, struct cmsghdr *);
int i;
int *fdp;
struct file **rp;
struct file *fp;
void *data;
socklen_t clen = control->m_len, datalen;
int error, newfds;
int f;
u_int newlen;
error = 0;
if (controlp != NULL) /* controlp == NULL => free control messages */
*controlp = NULL;
while (cm != NULL) {
if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
error = EINVAL;
break;
}
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
if (cm->cmsg_level == SOL_SOCKET
&& cm->cmsg_type == SCM_RIGHTS) {
newfds = datalen / sizeof(struct file *);
rp = data;
/* If we're not outputting the descriptors free them. */
if (error || controlp == NULL) {
unp_freerights(rp, newfds);
goto next;
}
FILEDESC_LOCK(td->td_proc->p_fd);
/* if the new FD's will not fit free them. */
if (!fdavail(td, newfds)) {
FILEDESC_UNLOCK(td->td_proc->p_fd);
error = EMSGSIZE;
unp_freerights(rp, newfds);
goto next;
}
/*
* now change each pointer to an fd in the global
* table to an integer that is the index to the
* local fd table entry that we set up to point
* to the global one we are transferring.
*/
newlen = newfds * sizeof(int);
*controlp = sbcreatecontrol(NULL, newlen,
SCM_RIGHTS, SOL_SOCKET);
if (*controlp == NULL) {
FILEDESC_UNLOCK(td->td_proc->p_fd);
error = E2BIG;
unp_freerights(rp, newfds);
goto next;
}
fdp = (int *)
CMSG_DATA(mtod(*controlp, struct cmsghdr *));
for (i = 0; i < newfds; i++) {
if (fdalloc(td, 0, &f))
panic("unp_externalize fdalloc failed");
fp = *rp++;
td->td_proc->p_fd->fd_ofiles[f] = fp;
FILE_LOCK(fp);
fp->f_msgcount--;
FILE_UNLOCK(fp);
unp_rights--;
*fdp++ = f;
}
FILEDESC_UNLOCK(td->td_proc->p_fd);
} else { /* We can just copy anything else across */
if (error || controlp == NULL)
goto next;
*controlp = sbcreatecontrol(NULL, datalen,
cm->cmsg_type, cm->cmsg_level);
if (*controlp == NULL) {
error = ENOBUFS;
goto next;
}
bcopy(data,
CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
datalen);
}
controlp = &(*controlp)->m_next;
next:
if (CMSG_SPACE(datalen) < clen) {
clen -= CMSG_SPACE(datalen);
cm = (struct cmsghdr *)
((caddr_t)cm + CMSG_SPACE(datalen));
} else {
clen = 0;
cm = NULL;
}
}
m_freem(control);
return (error);
}
void
unp_init(void)
{
unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
if (unp_zone == NULL)
panic("unp_init");
uma_zone_set_max(unp_zone, nmbclusters);
LIST_INIT(&unp_dhead);
LIST_INIT(&unp_shead);
UNP_LOCK_INIT();
}
static int
unp_internalize(controlp, td)
struct mbuf **controlp;
struct thread *td;
{
struct mbuf *control = *controlp;
struct proc *p = td->td_proc;
struct filedesc *fdescp = p->p_fd;
struct cmsghdr *cm = mtod(control, struct cmsghdr *);
struct cmsgcred *cmcred;
struct file **rp;
struct file *fp;
struct timeval *tv;
int i, fd, *fdp;
void *data;
socklen_t clen = control->m_len, datalen;
int error, oldfds;
u_int newlen;
error = 0;
*controlp = NULL;
while (cm != NULL) {
if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
|| cm->cmsg_len > clen) {
error = EINVAL;
goto out;
}
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
switch (cm->cmsg_type) {
/*
* Fill in credential information.
*/
case SCM_CREDS:
*controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
SCM_CREDS, SOL_SOCKET);
if (*controlp == NULL) {
error = ENOBUFS;
goto out;
}
cmcred = (struct cmsgcred *)
CMSG_DATA(mtod(*controlp, struct cmsghdr *));
cmcred->cmcred_pid = p->p_pid;
cmcred->cmcred_uid = td->td_ucred->cr_ruid;
cmcred->cmcred_gid = td->td_ucred->cr_rgid;
cmcred->cmcred_euid = td->td_ucred->cr_uid;
cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
CMGROUP_MAX);
for (i = 0; i < cmcred->cmcred_ngroups; i++)
cmcred->cmcred_groups[i] =
td->td_ucred->cr_groups[i];
break;
case SCM_RIGHTS:
oldfds = datalen / sizeof (int);
/*
* check that all the FDs passed in refer to legal files
* If not, reject the entire operation.
*/
fdp = data;
FILEDESC_LOCK(fdescp);
for (i = 0; i < oldfds; i++) {
fd = *fdp++;
if ((unsigned)fd >= fdescp->fd_nfiles ||
fdescp->fd_ofiles[fd] == NULL) {
FILEDESC_UNLOCK(fdescp);
error = EBADF;
goto out;
}
fp = fdescp->fd_ofiles[fd];
if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
FILEDESC_UNLOCK(fdescp);
error = EOPNOTSUPP;
goto out;
}
}
/*
* Now replace the integer FDs with pointers to
* the associated global file table entry..
*/
newlen = oldfds * sizeof(struct file *);
*controlp = sbcreatecontrol(NULL, newlen,
SCM_RIGHTS, SOL_SOCKET);
if (*controlp == NULL) {
FILEDESC_UNLOCK(fdescp);
error = E2BIG;
goto out;
}
fdp = data;
rp = (struct file **)
CMSG_DATA(mtod(*controlp, struct cmsghdr *));
for (i = 0; i < oldfds; i++) {
fp = fdescp->fd_ofiles[*fdp++];
*rp++ = fp;
FILE_LOCK(fp);
fp->f_count++;
fp->f_msgcount++;
FILE_UNLOCK(fp);
unp_rights++;
}
FILEDESC_UNLOCK(fdescp);
break;
case SCM_TIMESTAMP:
*controlp = sbcreatecontrol(NULL, sizeof(*tv),
SCM_TIMESTAMP, SOL_SOCKET);
if (*controlp == NULL) {
error = ENOBUFS;
goto out;
}
tv = (struct timeval *)
CMSG_DATA(mtod(*controlp, struct cmsghdr *));
microtime(tv);
break;
default:
error = EINVAL;
goto out;
}
controlp = &(*controlp)->m_next;
if (CMSG_SPACE(datalen) < clen) {
clen -= CMSG_SPACE(datalen);
cm = (struct cmsghdr *)
((caddr_t)cm + CMSG_SPACE(datalen));
} else {
clen = 0;
cm = NULL;
}
}
out:
m_freem(control);
return (error);
}
static int unp_defer, unp_gcing;
static void
unp_gc()
{
register struct file *fp, *nextfp;
register struct socket *so;
struct file **extra_ref, **fpp;
int nunref, i;
UNP_LOCK_ASSERT();
if (unp_gcing)
return;
unp_gcing = 1;
unp_defer = 0;
/*
* before going through all this, set all FDs to
* be NOT defered and NOT externally accessible
*/
/*
* XXXRW: Acquiring a sleep lock while holding UNP
* mutex cannot be a good thing.
*/
sx_slock(&filelist_lock);
LIST_FOREACH(fp, &filehead, f_list)
fp->f_gcflag &= ~(FMARK|FDEFER);
do {
LIST_FOREACH(fp, &filehead, f_list) {
FILE_LOCK(fp);
/*
* If the file is not open, skip it
*/
if (fp->f_count == 0) {
FILE_UNLOCK(fp);
continue;
}
/*
* If we already marked it as 'defer' in a
* previous pass, then try process it this time
* and un-mark it
*/
if (fp->f_gcflag & FDEFER) {
fp->f_gcflag &= ~FDEFER;
unp_defer--;
} else {
/*
* if it's not defered, then check if it's
* already marked.. if so skip it
*/
if (fp->f_gcflag & FMARK) {
FILE_UNLOCK(fp);
continue;
}
/*
* If all references are from messages
* in transit, then skip it. it's not
* externally accessible.
*/
if (fp->f_count == fp->f_msgcount) {
FILE_UNLOCK(fp);
continue;
}
/*
* If it got this far then it must be
* externally accessible.
*/
fp->f_gcflag |= FMARK;
}
/*
* either it was defered, or it is externally
* accessible and not already marked so.
* Now check if it is possibly one of OUR sockets.
*/
if (fp->f_type != DTYPE_SOCKET ||
(so = fp->f_data) == NULL) {
FILE_UNLOCK(fp);
continue;
}
FILE_UNLOCK(fp);
if (so->so_proto->pr_domain != &localdomain ||
(so->so_proto->pr_flags&PR_RIGHTS) == 0)
continue;
#ifdef notdef
if (so->so_rcv.sb_flags & SB_LOCK) {
/*
* This is problematical; it's not clear
* we need to wait for the sockbuf to be
* unlocked (on a uniprocessor, at least),
* and it's also not clear what to do
* if sbwait returns an error due to receipt
* of a signal. If sbwait does return
* an error, we'll go into an infinite
* loop. Delete all of this for now.
*/
(void) sbwait(&so->so_rcv);
goto restart;
}
#endif
/*
* So, Ok, it's one of our sockets and it IS externally
* accessible (or was defered). Now we look
* to see if we hold any file descriptors in its
* message buffers. Follow those links and mark them
* as accessible too.
*/
unp_scan(so->so_rcv.sb_mb, unp_mark);
}
} while (unp_defer);
sx_sunlock(&filelist_lock);
/*
* We grab an extra reference to each of the file table entries
* that are not otherwise accessible and then free the rights
* that are stored in messages on them.
*
* The bug in the orginal code is a little tricky, so I'll describe
* what's wrong with it here.
*
* It is incorrect to simply unp_discard each entry for f_msgcount
* times -- consider the case of sockets A and B that contain
* references to each other. On a last close of some other socket,
* we trigger a gc since the number of outstanding rights (unp_rights)
* is non-zero. If during the sweep phase the gc code un_discards,
* we end up doing a (full) closef on the descriptor. A closef on A
* results in the following chain. Closef calls soo_close, which
* calls soclose. Soclose calls first (through the switch
* uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
* returns because the previous instance had set unp_gcing, and
* we return all the way back to soclose, which marks the socket
* with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
* to free up the rights that are queued in messages on the socket A,
* i.e., the reference on B. The sorflush calls via the dom_dispose
* switch unp_dispose, which unp_scans with unp_discard. This second
* instance of unp_discard just calls closef on B.
*
* Well, a similar chain occurs on B, resulting in a sorflush on B,
* which results in another closef on A. Unfortunately, A is already
* being closed, and the descriptor has already been marked with
* SS_NOFDREF, and soclose panics at this point.
*
* Here, we first take an extra reference to each inaccessible
* descriptor. Then, we call sorflush ourself, since we know
* it is a Unix domain socket anyhow. After we destroy all the
* rights carried in messages, we do a last closef to get rid
* of our extra reference. This is the last close, and the
* unp_detach etc will shut down the socket.
*
* 91/09/19, bsy@cs.cmu.edu
*/
extra_ref = malloc(nfiles * sizeof(struct file *), M_TEMP, M_WAITOK);
sx_slock(&filelist_lock);
for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref;
fp != NULL; fp = nextfp) {
nextfp = LIST_NEXT(fp, f_list);
FILE_LOCK(fp);
/*
* If it's not open, skip it
*/
if (fp->f_count == 0) {
FILE_UNLOCK(fp);
continue;
}
/*
* If all refs are from msgs, and it's not marked accessible
* then it must be referenced from some unreachable cycle
* of (shut-down) FDs, so include it in our
* list of FDs to remove
*/
if (fp->f_count == fp->f_msgcount && !(fp->f_gcflag & FMARK)) {
*fpp++ = fp;
nunref++;
fp->f_count++;
}
FILE_UNLOCK(fp);
}
sx_sunlock(&filelist_lock);
/*
* for each FD on our hit list, do the following two things
*/
for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
struct file *tfp = *fpp;
FILE_LOCK(tfp);
if (tfp->f_type == DTYPE_SOCKET &&
tfp->f_data != NULL) {
FILE_UNLOCK(tfp);
sorflush(tfp->f_data);
} else {
FILE_UNLOCK(tfp);
}
}
for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp)
closef(*fpp, (struct thread *) NULL);
free(extra_ref, M_TEMP);
unp_gcing = 0;
}
void
unp_dispose(m)
struct mbuf *m;
{
if (m)
unp_scan(m, unp_discard);
}
static int
unp_listen(unp, td)
struct unpcb *unp;
struct thread *td;
{
UNP_LOCK_ASSERT();
/*
* XXXRW: Why populate the local peer cred with our own credential?
*/
cru2x(td->td_ucred, &unp->unp_peercred);
unp->unp_flags |= UNP_HAVEPCCACHED;
return (0);
}
static void
unp_scan(m0, op)
register struct mbuf *m0;
void (*op)(struct file *);
{
struct mbuf *m;
struct file **rp;
struct cmsghdr *cm;
void *data;
int i;
socklen_t clen, datalen;
int qfds;
while (m0 != NULL) {
for (m = m0; m; m = m->m_next) {
if (m->m_type != MT_CONTROL)
continue;
cm = mtod(m, struct cmsghdr *);
clen = m->m_len;
while (cm != NULL) {
if (sizeof(*cm) > clen || cm->cmsg_len > clen)
break;
data = CMSG_DATA(cm);
datalen = (caddr_t)cm + cm->cmsg_len
- (caddr_t)data;
if (cm->cmsg_level == SOL_SOCKET &&
cm->cmsg_type == SCM_RIGHTS) {
qfds = datalen / sizeof (struct file *);
rp = data;
for (i = 0; i < qfds; i++)
(*op)(*rp++);
}
if (CMSG_SPACE(datalen) < clen) {
clen -= CMSG_SPACE(datalen);
cm = (struct cmsghdr *)
((caddr_t)cm + CMSG_SPACE(datalen));
} else {
clen = 0;
cm = NULL;
}
}
}
m0 = m0->m_act;
}
}
static void
unp_mark(fp)
struct file *fp;
{
if (fp->f_gcflag & FMARK)
return;
unp_defer++;
fp->f_gcflag |= (FMARK|FDEFER);
}
static void
unp_discard(fp)
struct file *fp;
{
FILE_LOCK(fp);
fp->f_msgcount--;
unp_rights--;
FILE_UNLOCK(fp);
(void) closef(fp, (struct thread *)NULL);
}
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