d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
67dafe43c1
freebsd-skq/sys/kern/uipc_usrreq.c
Robert Watson 8c96f9c193 Move unlock of global UNIX domain socket lock slightly lower in 
unp_connect(): it is expected to return with the lock held, and two
possible error paths otherwise returned with it unlocked.

The fix committed here is slightly different from the patch in the
PR, but along an alternative line suggested in the PR.

PR:		119778
MFC after:	3 days
Submitted by:	James Juran <james dot juran at baesystems dot com>
2008-01-18 19:16:03 +00:00

2217 lines
54 KiB
C
Raw Blame History

/*-
* Copyright (c) 1982, 1986, 1989, 1991, 1993
* The Regents of the University of California.
* Copyright (c) 2004-2007 Robert N. M. Watson
* 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
*/
/*
* UNIX Domain (Local) Sockets
*
* This is an implementation of UNIX (local) domain sockets. Each socket has
* an associated struct unpcb (UNIX protocol control block). Stream sockets
* may be connected to 0 or 1 other socket. Datagram sockets may be
* connected to 0, 1, or many other sockets. Sockets may be created and
* connected in pairs (socketpair(2)), or bound/connected to using the file
* system name space. For most purposes, only the receive socket buffer is
* used, as sending on one socket delivers directly to the receive socket
* buffer of a second socket.
*
* The implementation is substantially complicated by the fact that
* "ancillary data", such as file descriptors or credentials, may be passed
* across UNIX domain sockets. The potential for passing UNIX domain sockets
* over other UNIX domain sockets requires the implementation of a simple
* garbage collector to find and tear down cycles of disconnected sockets.
*
* TODO:
* SEQPACKET, RDM
* rethink name space problems
* need a proper out-of-band
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#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/eventhandler.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.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/taskqueue.h>
#include <sys/un.h>
#include <sys/unpcb.h>
#include <sys/vnode.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#include <security/mac/mac_framework.h>
#include <vm/uma.h>
static uma_zone_t unp_zone;
static unp_gen_t unp_gencnt;
static u_int unp_count; /* Count of local sockets. */
static ino_t unp_ino; /* Prototype for fake inode numbers. */
static int unp_rights; /* File descriptors in flight. */
static struct unp_head unp_shead; /* List of local stream sockets. */
static struct unp_head unp_dhead; /* List of local datagram sockets. */
static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
/*
* Garbage collection of cyclic file descriptor/socket references occurs
* asynchronously in a taskqueue context in order to avoid recursion and
* reentrance in the UNIX domain socket, file descriptor, and socket layer
* code. See unp_gc() for a full description.
*/
static struct task unp_gc_task;
/*
* 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;
SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM");
SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
&unpst_sendspace, 0, "");
SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
&unpst_recvspace, 0, "");
SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
&unpdg_sendspace, 0, "");
SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
&unpdg_recvspace, 0, "");
SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
/*-
* Locking and synchronization:
*
* The global UNIX domain socket rwlock (unp_global_rwlock) protects all
* global variables, including the linked lists tracking the set of allocated
* UNIX domain sockets. The global rwlock also serves to prevent deadlock
* when more than one PCB lock is acquired at a time (i.e., during
* connect()). Finally, the global rwlock protects uncounted references from
* vnodes to sockets bound to those vnodes: to safely dereference the
* v_socket pointer, the global rwlock must be held while a full reference is
* acquired.
*
* UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
* allocated in pru_attach() and freed in pru_detach(). The validity of that
* pointer is an invariant, so no lock is required to dereference the so_pcb
* pointer if a valid socket reference is held by the caller. In practice,
* this is always true during operations performed on a socket. Each unpcb
* has a back-pointer to its socket, unp_socket, which will be stable under
* the same circumstances.
*
* This pointer may only be safely dereferenced as long as a valid reference
* to the unpcb is held. Typically, this reference will be from the socket,
* or from another unpcb when the referring unpcb's lock is held (in order
* that the reference not be invalidated during use). For example, to follow
* unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
* as unp_socket remains valid as long as the reference to unp_conn is valid.
*
* Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual
* atomic reads without the lock may be performed "lockless", but more
* complex reads and read-modify-writes require the mutex to be held. No
* lock order is defined between unpcb locks -- multiple unpcb locks may be
* acquired at the same time only when holding the global UNIX domain socket
* rwlock exclusively, which prevents deadlocks.
*
* Blocking with UNIX domain sockets is a tricky issue: unlike most network
* protocols, bind() is a non-atomic operation, and connect() requires
* potential sleeping in the protocol, due to potentially waiting on local or
* distributed file systems. We try to separate "lookup" operations, which
* may sleep, and the IPC operations themselves, which typically can occur
* with relative atomicity as locks can be held over the entire operation.
*
* Another tricky issue is simultaneous multi-threaded or multi-process
* access to a single UNIX domain socket. These are handled by the flags
* UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
* binding, both of which involve dropping UNIX domain socket locks in order
* to perform namei() and other file system operations.
*/
static struct rwlock unp_global_rwlock;
#define UNP_GLOBAL_LOCK_INIT() rw_init(&unp_global_rwlock, \
"unp_global_rwlock")
#define UNP_GLOBAL_LOCK_ASSERT() rw_assert(&unp_global_rwlock, \
RA_LOCKED)
#define UNP_GLOBAL_UNLOCK_ASSERT() rw_assert(&unp_global_rwlock, \
RA_UNLOCKED)
#define UNP_GLOBAL_WLOCK() rw_wlock(&unp_global_rwlock)
#define UNP_GLOBAL_WUNLOCK() rw_wunlock(&unp_global_rwlock)
#define UNP_GLOBAL_WLOCK_ASSERT() rw_assert(&unp_global_rwlock, \
RA_WLOCKED)
#define UNP_GLOBAL_WOWNED() rw_wowned(&unp_global_rwlock)
#define UNP_GLOBAL_RLOCK() rw_rlock(&unp_global_rwlock)
#define UNP_GLOBAL_RUNLOCK() rw_runlock(&unp_global_rwlock)
#define UNP_GLOBAL_RLOCK_ASSERT() rw_assert(&unp_global_rwlock, \
RA_RLOCKED)
#define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \
"unp_mtx", "unp_mtx", \
MTX_DUPOK|MTX_DEF|MTX_RECURSE)
#define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx)
#define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx)
#define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx)
#define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED)
static int unp_connect(struct socket *, struct sockaddr *,
struct thread *);
static int unp_connect2(struct socket *so, struct socket *so2, int);
static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
static void unp_shutdown(struct unpcb *);
static void unp_drop(struct unpcb *, int);
static void unp_gc(__unused void *, int);
static void unp_scan(struct mbuf *, void (*)(struct file *));
static void unp_discard(struct file *);
static void unp_freerights(struct file **, int);
static int unp_internalize(struct mbuf **, struct thread *);
static void unp_internalize_fp(struct file *);
static void unp_externalize_fp(struct file *);
static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *);
/*
* Definitions of protocols supported in the LOCAL domain.
*/
static struct domain localdomain;
static struct protosw localsw[] = {
{
.pr_type = SOCK_STREAM,
.pr_domain = &localdomain,
.pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
.pr_ctloutput = &uipc_ctloutput,
.pr_usrreqs = &uipc_usrreqs
},
{
.pr_type = SOCK_DGRAM,
.pr_domain = &localdomain,
.pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS,
.pr_usrreqs = &uipc_usrreqs
},
};
static struct domain localdomain = {
.dom_family = AF_LOCAL,
.dom_name = "local",
.dom_init = unp_init,
.dom_externalize = unp_externalize,
.dom_dispose = unp_dispose,
.dom_protosw = localsw,
.dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])]
};
DOMAIN_SET(local);
static void
uipc_abort(struct socket *so)
{
struct unpcb *unp, *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (unp2 != NULL) {
UNP_PCB_LOCK(unp2);
unp_drop(unp2, ECONNABORTED);
UNP_PCB_UNLOCK(unp2);
}
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
}
static int
uipc_accept(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp, *unp2;
const struct sockaddr *sa;
/*
* Pass back name of connected socket, if it was bound and we are
* still connected (our peer may have closed already!).
*/
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_GLOBAL_RLOCK();
unp2 = unp->unp_conn;
if (unp2 != NULL && unp2->unp_addr != NULL) {
UNP_PCB_LOCK(unp2);
sa = (struct sockaddr *) unp2->unp_addr;
bcopy(sa, *nam, sa->sa_len);
UNP_PCB_UNLOCK(unp2);
} else {
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
}
UNP_GLOBAL_RUNLOCK();
return (0);
}
static int
uipc_attach(struct socket *so, int proto, struct thread *td)
{
u_long sendspace, recvspace;
struct unpcb *unp;
int error, locked;
KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
switch (so->so_type) {
case SOCK_STREAM:
sendspace = unpst_sendspace;
recvspace = unpst_recvspace;
break;
case SOCK_DGRAM:
sendspace = unpdg_sendspace;
recvspace = unpdg_recvspace;
break;
default:
panic("uipc_attach");
}
error = soreserve(so, sendspace, recvspace);
if (error)
return (error);
}
unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
if (unp == NULL)
return (ENOBUFS);
LIST_INIT(&unp->unp_refs);
UNP_PCB_LOCK_INIT(unp);
unp->unp_socket = so;
so->so_pcb = unp;
unp->unp_refcount = 1;
/*
* uipc_attach() may be called indirectly from within the UNIX domain
* socket code via sonewconn() in unp_connect(). Since rwlocks can
* not be recursed, we do the closest thing.
*/
locked = 0;
if (!UNP_GLOBAL_WOWNED()) {
UNP_GLOBAL_WLOCK();
locked = 1;
}
unp->unp_gencnt = ++unp_gencnt;
unp_count++;
LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead,
unp, unp_link);
if (locked)
UNP_GLOBAL_WUNLOCK();
return (0);
}
static int
uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct sockaddr_un *soun = (struct sockaddr_un *)nam;
struct vattr vattr;
int error, namelen, vfslocked;
struct nameidata nd;
struct unpcb *unp;
struct vnode *vp;
struct mount *mp;
char *buf;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
if (namelen <= 0)
return (EINVAL);
/*
* We don't allow simultaneous bind() calls on a single UNIX domain
* socket, so flag in-progress operations, and return an error if an
* operation is already in progress.
*
* Historically, we have not allowed a socket to be rebound, so this
* also returns an error. Not allowing re-binding simplifies the
* implementation and avoids a great many possible failure modes.
*/
UNP_PCB_LOCK(unp);
if (unp->unp_vnode != NULL) {
UNP_PCB_UNLOCK(unp);
return (EINVAL);
}
if (unp->unp_flags & UNP_BINDING) {
UNP_PCB_UNLOCK(unp);
return (EALREADY);
}
unp->unp_flags |= UNP_BINDING;
UNP_PCB_UNLOCK(unp);
buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
strlcpy(buf, soun->sun_path, namelen + 1);
restart:
vfslocked = 0;
NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME,
UIO_SYSSPACE, buf, td);
/* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
error = namei(&nd);
if (error)
goto error;
vp = nd.ni_vp;
vfslocked = NDHASGIANT(&nd);
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 error;
}
error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
if (error)
goto error;
VFS_UNLOCK_GIANT(vfslocked);
goto restart;
}
VATTR_NULL(&vattr);
vattr.va_type = VSOCK;
vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
#ifdef MAC
error = mac_vnode_check_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) {
vn_finished_write(mp);
goto error;
}
vp = nd.ni_vp;
ASSERT_VOP_ELOCKED(vp, "uipc_bind");
soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
vp->v_socket = unp->unp_socket;
unp->unp_vnode = vp;
unp->unp_addr = soun;
unp->unp_flags &= ~UNP_BINDING;
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
VFS_UNLOCK_GIANT(vfslocked);
free(buf, M_TEMP);
return (0);
error:
VFS_UNLOCK_GIANT(vfslocked);
UNP_PCB_LOCK(unp);
unp->unp_flags &= ~UNP_BINDING;
UNP_PCB_UNLOCK(unp);
free(buf, M_TEMP);
return (error);
}
static int
uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error;
KASSERT(td == curthread, ("uipc_connect: td != curthread"));
UNP_GLOBAL_WLOCK();
error = unp_connect(so, nam, td);
UNP_GLOBAL_WUNLOCK();
return (error);
}
static void
uipc_close(struct socket *so)
{
struct unpcb *unp, *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (unp2 != NULL) {
UNP_PCB_LOCK(unp2);
unp_disconnect(unp, unp2);
UNP_PCB_UNLOCK(unp2);
}
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
}
int
uipc_connect2(struct socket *so1, struct socket *so2)
{
struct unpcb *unp, *unp2;
int error;
UNP_GLOBAL_WLOCK();
unp = so1->so_pcb;
KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
UNP_PCB_LOCK(unp);
unp2 = so2->so_pcb;
KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
UNP_PCB_LOCK(unp2);
error = unp_connect2(so1, so2, PRU_CONNECT2);
UNP_PCB_UNLOCK(unp2);
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
return (error);
}
/* control is EOPNOTSUPP */
static void
uipc_detach(struct socket *so)
{
struct unpcb *unp, *unp2;
struct sockaddr_un *saved_unp_addr;
struct vnode *vp;
int freeunp, local_unp_rights;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
LIST_REMOVE(unp, unp_link);
unp->unp_gencnt = ++unp_gencnt;
--unp_count;
/*
* XXXRW: Should assert vp->v_socket == so.
*/
if ((vp = unp->unp_vnode) != NULL) {
unp->unp_vnode->v_socket = NULL;
unp->unp_vnode = NULL;
}
unp2 = unp->unp_conn;
if (unp2 != NULL) {
UNP_PCB_LOCK(unp2);
unp_disconnect(unp, unp2);
UNP_PCB_UNLOCK(unp2);
}
/*
* We hold the global lock, so it's OK to acquire multiple pcb locks
* at a time.
*/
while (!LIST_EMPTY(&unp->unp_refs)) {
struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
UNP_PCB_LOCK(ref);
unp_drop(ref, ECONNRESET);
UNP_PCB_UNLOCK(ref);
}
local_unp_rights = unp_rights;
UNP_GLOBAL_WUNLOCK();
unp->unp_socket->so_pcb = NULL;
saved_unp_addr = unp->unp_addr;
unp->unp_addr = NULL;
unp->unp_refcount--;
freeunp = (unp->unp_refcount == 0);
if (saved_unp_addr != NULL)
FREE(saved_unp_addr, M_SONAME);
if (freeunp) {
UNP_PCB_LOCK_DESTROY(unp);
uma_zfree(unp_zone, unp);
} else
UNP_PCB_UNLOCK(unp);
if (vp) {
int vfslocked;
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vrele(vp);
VFS_UNLOCK_GIANT(vfslocked);
}
if (local_unp_rights)
taskqueue_enqueue(taskqueue_thread, &unp_gc_task);
}
static int
uipc_disconnect(struct socket *so)
{
struct unpcb *unp, *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (unp2 != NULL) {
UNP_PCB_LOCK(unp2);
unp_disconnect(unp, unp2);
UNP_PCB_UNLOCK(unp2);
}
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
return (0);
}
static int
uipc_listen(struct socket *so, int backlog, struct thread *td)
{
struct unpcb *unp;
int error;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
UNP_PCB_LOCK(unp);
if (unp->unp_vnode == NULL) {
UNP_PCB_UNLOCK(unp);
return (EINVAL);
}
SOCK_LOCK(so);
error = solisten_proto_check(so);
if (error == 0) {
cru2x(td->td_ucred, &unp->unp_peercred);
unp->unp_flags |= UNP_HAVEPCCACHED;
solisten_proto(so, backlog);
}
SOCK_UNLOCK(so);
UNP_PCB_UNLOCK(unp);
return (error);
}
static int
uipc_peeraddr(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp, *unp2;
const struct sockaddr *sa;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_PCB_LOCK(unp);
/*
* 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.
*/
unp2 = unp->unp_conn;
if (unp2 != NULL) {
UNP_PCB_LOCK(unp2);
if (unp2->unp_addr != NULL)
sa = (struct sockaddr *) unp->unp_conn->unp_addr;
else
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
UNP_PCB_UNLOCK(unp2);
} else {
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
}
UNP_PCB_UNLOCK(unp);
return (0);
}
static int
uipc_rcvd(struct socket *so, int flags)
{
struct unpcb *unp, *unp2;
struct socket *so2;
u_int mbcnt, sbcc;
u_long newhiwat;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
if (so->so_type == SOCK_DGRAM)
panic("uipc_rcvd DGRAM?");
if (so->so_type != SOCK_STREAM)
panic("uipc_rcvd unknown socktype");
/*
* Adjust backpressure on sender and wakeup any waiting to write.
*
* The unp lock is acquired to maintain the validity of the unp_conn
* pointer; no lock on unp2 is required as unp2->unp_socket will be
* static as long as we don't permit unp2 to disconnect from unp,
* which is prevented by the lock on unp. We cache values from
* so_rcv to avoid holding the so_rcv lock over the entire
* transaction on the remote so_snd.
*/
SOCKBUF_LOCK(&so->so_rcv);
mbcnt = so->so_rcv.sb_mbcnt;
sbcc = so->so_rcv.sb_cc;
SOCKBUF_UNLOCK(&so->so_rcv);
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (unp2 == NULL) {
UNP_PCB_UNLOCK(unp);
return (0);
}
so2 = unp2->unp_socket;
SOCKBUF_LOCK(&so2->so_snd);
so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt;
newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc;
(void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
newhiwat, RLIM_INFINITY);
sowwakeup_locked(so2);
unp->unp_mbcnt = mbcnt;
unp->unp_cc = sbcc;
UNP_PCB_UNLOCK(unp);
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)
{
struct unpcb *unp, *unp2;
struct socket *so2;
u_int mbcnt, sbcc;
u_long newhiwat;
int error = 0;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
if (flags & PRUS_OOB) {
error = EOPNOTSUPP;
goto release;
}
if (control != NULL && (error = unp_internalize(&control, td)))
goto release;
if ((nam != NULL) || (flags & PRUS_EOF))
UNP_GLOBAL_WLOCK();
else
UNP_GLOBAL_RLOCK();
switch (so->so_type) {
case SOCK_DGRAM:
{
const struct sockaddr *from;
unp2 = unp->unp_conn;
if (nam != NULL) {
UNP_GLOBAL_WLOCK_ASSERT();
if (unp2 != NULL) {
error = EISCONN;
break;
}
error = unp_connect(so, nam, td);
if (error)
break;
unp2 = unp->unp_conn;
}
/*
* Because connect() and send() are non-atomic in a sendto()
* with a target address, it's possible that the socket will
* have disconnected before the send() can run. In that case
* return the slightly counter-intuitive but otherwise
* correct error that the socket is not connected.
*/
if (unp2 == NULL) {
error = ENOTCONN;
break;
}
/* Lockless read. */
if (unp2->unp_flags & UNP_WANTCRED)
control = unp_addsockcred(td, control);
UNP_PCB_LOCK(unp);
if (unp->unp_addr != NULL)
from = (struct sockaddr *)unp->unp_addr;
else
from = &sun_noname;
so2 = unp2->unp_socket;
SOCKBUF_LOCK(&so2->so_rcv);
if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
sorwakeup_locked(so2);
m = NULL;
control = NULL;
} else {
SOCKBUF_UNLOCK(&so2->so_rcv);
error = ENOBUFS;
}
if (nam != NULL) {
UNP_GLOBAL_WLOCK_ASSERT();
UNP_PCB_LOCK(unp2);
unp_disconnect(unp, unp2);
UNP_PCB_UNLOCK(unp2);
}
UNP_PCB_UNLOCK(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) {
UNP_GLOBAL_WLOCK_ASSERT();
error = unp_connect(so, nam, td);
if (error)
break; /* XXX */
} else {
error = ENOTCONN;
break;
}
}
/* Lockless read. */
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
error = EPIPE;
break;
}
/*
* Because connect() and send() are non-atomic in a sendto()
* with a target address, it's possible that the socket will
* have disconnected before the send() can run. In that case
* return the slightly counter-intuitive but otherwise
* correct error that the socket is not connected.
*
* Locking here must be done carefully: the global lock
* prevents interconnections between unpcbs from changing, so
* we can traverse from unp to unp2 without acquiring unp's
* lock. Socket buffer locks follow unpcb locks, so we can
* acquire both remote and lock socket buffer locks.
*/
unp2 = unp->unp_conn;
if (unp2 == NULL) {
error = ENOTCONN;
break;
}
so2 = unp2->unp_socket;
UNP_PCB_LOCK(unp2);
SOCKBUF_LOCK(&so2->so_rcv);
if (unp2->unp_flags & UNP_WANTCRED) {
/*
* Credentials are passed only once on SOCK_STREAM.
*/
unp2->unp_flags &= ~UNP_WANTCRED;
control = unp_addsockcred(td, control);
}
/*
* 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);
mbcnt = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt;
unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt;
sbcc = so2->so_rcv.sb_cc;
sorwakeup_locked(so2);
SOCKBUF_LOCK(&so->so_snd);
newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc);
(void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
newhiwat, RLIM_INFINITY);
so->so_snd.sb_mbmax -= mbcnt;
SOCKBUF_UNLOCK(&so->so_snd);
unp2->unp_cc = sbcc;
UNP_PCB_UNLOCK(unp2);
m = NULL;
break;
default:
panic("uipc_send unknown socktype");
}
/*
* SEND_EOF is equivalent to a SEND followed by a SHUTDOWN.
*/
if (flags & PRUS_EOF) {
UNP_PCB_LOCK(unp);
socantsendmore(so);
unp_shutdown(unp);
UNP_PCB_UNLOCK(unp);
}
if ((nam != NULL) || (flags & PRUS_EOF))
UNP_GLOBAL_WUNLOCK();
else
UNP_GLOBAL_RUNLOCK();
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, *unp2;
struct socket *so2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
sb->st_blksize = so->so_snd.sb_hiwat;
UNP_GLOBAL_RLOCK();
UNP_PCB_LOCK(unp);
unp2 = unp->unp_conn;
if (so->so_type == SOCK_STREAM && unp2 != NULL) {
so2 = unp2->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_PCB_UNLOCK(unp);
UNP_GLOBAL_RUNLOCK();
return (0);
}
static int
uipc_shutdown(struct socket *so)
{
struct unpcb *unp;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
socantsendmore(so);
unp_shutdown(unp);
UNP_PCB_UNLOCK(unp);
UNP_GLOBAL_WUNLOCK();
return (0);
}
static int
uipc_sockaddr(struct socket *so, struct sockaddr **nam)
{
struct unpcb *unp;
const struct sockaddr *sa;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
UNP_PCB_LOCK(unp);
if (unp->unp_addr != NULL)
sa = (struct sockaddr *) unp->unp_addr;
else
sa = &sun_noname;
bcopy(sa, *nam, sa->sa_len);
UNP_PCB_UNLOCK(unp);
return (0);
}
struct pr_usrreqs uipc_usrreqs = {
.pru_abort = uipc_abort,
.pru_accept = uipc_accept,
.pru_attach = uipc_attach,
.pru_bind = uipc_bind,
.pru_connect = uipc_connect,
.pru_connect2 = uipc_connect2,
.pru_detach = uipc_detach,
.pru_disconnect = uipc_disconnect,
.pru_listen = uipc_listen,
.pru_peeraddr = uipc_peeraddr,
.pru_rcvd = uipc_rcvd,
.pru_send = uipc_send,
.pru_sense = uipc_sense,
.pru_shutdown = uipc_shutdown,
.pru_sockaddr = uipc_sockaddr,
.pru_close = uipc_close,
};
int
uipc_ctloutput(struct socket *so, struct sockopt *sopt)
{
struct unpcb *unp;
struct xucred xu;
int error, optval;
if (sopt->sopt_level != 0)
return (EINVAL);
unp = sotounpcb(so);
KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
error = 0;
switch (sopt->sopt_dir) {
case SOPT_GET:
switch (sopt->sopt_name) {
case LOCAL_PEERCRED:
UNP_PCB_LOCK(unp);
if (unp->unp_flags & UNP_HAVEPC)
xu = unp->unp_peercred;
else {
if (so->so_type == SOCK_STREAM)
error = ENOTCONN;
else
error = EINVAL;
}
UNP_PCB_UNLOCK(unp);
if (error == 0)
error = sooptcopyout(sopt, &xu, sizeof(xu));
break;
case LOCAL_CREDS:
/* Unlocked read. */
optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
case LOCAL_CONNWAIT:
/* Unlocked read. */
optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
error = sooptcopyout(sopt, &optval, sizeof(optval));
break;
default:
error = EOPNOTSUPP;
break;
}
break;
case SOPT_SET:
switch (sopt->sopt_name) {
case LOCAL_CREDS:
case LOCAL_CONNWAIT:
error = sooptcopyin(sopt, &optval, sizeof(optval),
sizeof(optval));
if (error)
break;
#define OPTSET(bit) do { \
UNP_PCB_LOCK(unp); \
if (optval) \
unp->unp_flags |= bit; \
else \
unp->unp_flags &= ~bit; \
UNP_PCB_UNLOCK(unp); \
} while (0)
switch (sopt->sopt_name) {
case LOCAL_CREDS:
OPTSET(UNP_WANTCRED);
break;
case LOCAL_CONNWAIT:
OPTSET(UNP_CONNWAIT);
break;
default:
break;
}
break;
#undef OPTSET
default:
error = ENOPROTOOPT;
break;
}
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
struct sockaddr_un *soun = (struct sockaddr_un *)nam;
struct vnode *vp;
struct socket *so2, *so3;
struct unpcb *unp, *unp2, *unp3;
int error, len, vfslocked;
struct nameidata nd;
char buf[SOCK_MAXADDRLEN];
struct sockaddr *sa;
UNP_GLOBAL_WLOCK_ASSERT();
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
if (len <= 0)
return (EINVAL);
strlcpy(buf, soun->sun_path, len + 1);
UNP_PCB_LOCK(unp);
if (unp->unp_flags & UNP_CONNECTING) {
UNP_PCB_UNLOCK(unp);
return (EALREADY);
}
UNP_GLOBAL_WUNLOCK();
unp->unp_flags |= UNP_CONNECTING;
UNP_PCB_UNLOCK(unp);
sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf,
td);
error = namei(&nd);
if (error)
vp = NULL;
else
vp = nd.ni_vp;
ASSERT_VOP_LOCKED(vp, "unp_connect");
vfslocked = NDHASGIANT(&nd);
NDFREE(&nd, NDF_ONLY_PNBUF);
if (error)
goto bad;
if (vp->v_type != VSOCK) {
error = ENOTSOCK;
goto bad;
}
#ifdef MAC
error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
if (error)
goto bad;
#endif
error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
if (error)
goto bad;
VFS_UNLOCK_GIANT(vfslocked);
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
/*
* Lock global lock for two reasons: make sure v_socket is stable,
* and to protect simultaneous locking of multiple pcbs.
*/
UNP_GLOBAL_WLOCK();
so2 = vp->v_socket;
if (so2 == NULL) {
error = ECONNREFUSED;
goto bad2;
}
if (so->so_type != so2->so_type) {
error = EPROTOTYPE;
goto bad2;
}
if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
if (so2->so_options & SO_ACCEPTCONN) {
/*
* We can't drop the global lock here or 'so2' may
* become invalid. As a result, we need to handle
* possibly lock recursion in uipc_attach.
*/
so3 = sonewconn(so2, 0);
} else
so3 = NULL;
if (so3 == NULL) {
error = ECONNREFUSED;
goto bad2;
}
unp = sotounpcb(so);
unp2 = sotounpcb(so2);
unp3 = sotounpcb(so3);
UNP_PCB_LOCK(unp);
UNP_PCB_LOCK(unp2);
UNP_PCB_LOCK(unp3);
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(); uipc_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;
if (unp2->unp_flags & UNP_WANTCRED)
unp3->unp_flags |= UNP_WANTCRED;
UNP_PCB_UNLOCK(unp3);
UNP_PCB_UNLOCK(unp2);
UNP_PCB_UNLOCK(unp);
#ifdef MAC
SOCK_LOCK(so);
mac_socketpeer_set_from_socket(so, so3);
mac_socketpeer_set_from_socket(so3, so);
SOCK_UNLOCK(so);
#endif
so2 = so3;
}
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
unp2 = sotounpcb(so2);
KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
UNP_PCB_LOCK(unp);
UNP_PCB_LOCK(unp2);
error = unp_connect2(so, so2, PRU_CONNECT);
UNP_PCB_UNLOCK(unp2);
UNP_PCB_UNLOCK(unp);
bad2:
UNP_GLOBAL_WUNLOCK();
if (vfslocked)
/*
* Giant has been previously acquired. This means filesystem
* isn't MPSAFE. Do it once again.
*/
mtx_lock(&Giant);
bad:
if (vp != NULL)
vput(vp);
VFS_UNLOCK_GIANT(vfslocked);
free(sa, M_SONAME);
UNP_GLOBAL_WLOCK();
UNP_PCB_LOCK(unp);
unp->unp_flags &= ~UNP_CONNECTING;
UNP_PCB_UNLOCK(unp);
return (error);
}
static int
unp_connect2(struct socket *so, struct socket *so2, int req)
{
struct unpcb *unp;
struct unpcb *unp2;
unp = sotounpcb(so);
KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
unp2 = sotounpcb(so2);
KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
UNP_GLOBAL_WLOCK_ASSERT();
UNP_PCB_LOCK_ASSERT(unp);
UNP_PCB_LOCK_ASSERT(unp2);
if (so2->so_type != so->so_type)
return (EPROTOTYPE);
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;
if (req == PRU_CONNECT &&
((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
soisconnecting(so);
else
soisconnected(so);
soisconnected(so2);
break;
default:
panic("unp_connect2");
}
return (0);
}
static void
unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
{
struct socket *so;
KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
UNP_GLOBAL_WLOCK_ASSERT();
UNP_PCB_LOCK_ASSERT(unp);
UNP_PCB_LOCK_ASSERT(unp2);
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;
}
}
/*
* unp_pcblist() walks the global list of struct unpcb's to generate a
* pointer list, bumping the refcount on each unpcb. It then copies them out
* sequentially, validating the generation number on each to see if it has
* been detached. All of this is necessary because copyout() may sleep on
* disk I/O.
*/
static int
unp_pcblist(SYSCTL_HANDLER_ARGS)
{
int error, i, n;
int freeunp;
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_GLOBAL_RLOCK();
gencnt = unp_gencnt;
n = unp_count;
UNP_GLOBAL_RUNLOCK();
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_GLOBAL_RLOCK();
for (unp = LIST_FIRST(head), i = 0; unp && i < n;
unp = LIST_NEXT(unp, unp_link)) {
UNP_PCB_LOCK(unp);
if (unp->unp_gencnt <= gencnt) {
if (cr_cansee(req->td->td_ucred,
unp->unp_socket->so_cred)) {
UNP_PCB_UNLOCK(unp);
continue;
}
unp_list[i++] = unp;
unp->unp_refcount++;
}
UNP_PCB_UNLOCK(unp);
}
UNP_GLOBAL_RUNLOCK();
n = i; /* In case we lost some during malloc. */
error = 0;
xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
for (i = 0; i < n; i++) {
unp = unp_list[i];
UNP_PCB_LOCK(unp);
unp->unp_refcount--;
if (unp->unp_refcount != 0 && 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);
UNP_PCB_UNLOCK(unp);
error = SYSCTL_OUT(req, xu, sizeof *xu);
} else {
freeunp = (unp->unp_refcount == 0);
UNP_PCB_UNLOCK(unp);
if (freeunp) {
UNP_PCB_LOCK_DESTROY(unp);
uma_zfree(unp_zone, unp);
}
}
}
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(struct unpcb *unp)
{
struct unpcb *unp2;
struct socket *so;
UNP_GLOBAL_WLOCK_ASSERT();
UNP_PCB_LOCK_ASSERT(unp);
unp2 = unp->unp_conn;
if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) {
so = unp2->unp_socket;
if (so != NULL)
socantrcvmore(so);
}
}
static void
unp_drop(struct unpcb *unp, int errno)
{
struct socket *so = unp->unp_socket;
struct unpcb *unp2;
UNP_GLOBAL_WLOCK_ASSERT();
UNP_PCB_LOCK_ASSERT(unp);
so->so_error = errno;
unp2 = unp->unp_conn;
if (unp2 == NULL)
return;
UNP_PCB_LOCK(unp2);
unp_disconnect(unp, unp2);
UNP_PCB_UNLOCK(unp2);
}
static void
unp_freerights(struct file **rp, int fdcount)
{
int i;
struct file *fp;
for (i = 0; i < fdcount; i++) {
/*
* Zero the pointer before calling unp_discard since it may
* end up in unp_gc()..
*
* XXXRW: This is less true than it used to be.
*/
fp = *rp;
*rp++ = NULL;
unp_discard(fp);
}
}
int
unp_externalize(struct mbuf *control, struct mbuf **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;
UNP_GLOBAL_UNLOCK_ASSERT();
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_XLOCK(td->td_proc->p_fd);
/* if the new FD's will not fit free them. */
if (!fdavail(td, newfds)) {
FILEDESC_XUNLOCK(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_XUNLOCK(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;
unp_externalize_fp(fp);
*fdp++ = f;
}
FILEDESC_XUNLOCK(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);
}
static void
unp_zone_change(void *tag)
{
uma_zone_set_max(unp_zone, maxsockets);
}
void
unp_init(void)
{
unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, 0);
if (unp_zone == NULL)
panic("unp_init");
uma_zone_set_max(unp_zone, maxsockets);
EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
NULL, EVENTHANDLER_PRI_ANY);
LIST_INIT(&unp_dhead);
LIST_INIT(&unp_shead);
TASK_INIT(&unp_gc_task, 0, unp_gc, NULL);
UNP_GLOBAL_LOCK_INIT();
}
static int
unp_internalize(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;
UNP_GLOBAL_UNLOCK_ASSERT();
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_SLOCK(fdescp);
for (i = 0; i < oldfds; i++) {
fd = *fdp++;
if ((unsigned)fd >= fdescp->fd_nfiles ||
fdescp->fd_ofiles[fd] == NULL) {
FILEDESC_SUNLOCK(fdescp);
error = EBADF;
goto out;
}
fp = fdescp->fd_ofiles[fd];
if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
FILEDESC_SUNLOCK(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_SUNLOCK(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;
unp_internalize_fp(fp);
}
FILEDESC_SUNLOCK(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 struct mbuf *
unp_addsockcred(struct thread *td, struct mbuf *control)
{
struct mbuf *m, *n, *n_prev;
struct sockcred *sc;
const struct cmsghdr *cm;
int ngroups;
int i;
ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
if (m == NULL)
return (control);
sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
sc->sc_uid = td->td_ucred->cr_ruid;
sc->sc_euid = td->td_ucred->cr_uid;
sc->sc_gid = td->td_ucred->cr_rgid;
sc->sc_egid = td->td_ucred->cr_gid;
sc->sc_ngroups = ngroups;
for (i = 0; i < sc->sc_ngroups; i++)
sc->sc_groups[i] = td->td_ucred->cr_groups[i];
/*
* Unlink SCM_CREDS control messages (struct cmsgcred), since just
* created SCM_CREDS control message (struct sockcred) has another
* format.
*/
if (control != NULL)
for (n = control, n_prev = NULL; n != NULL;) {
cm = mtod(n, struct cmsghdr *);
if (cm->cmsg_level == SOL_SOCKET &&
cm->cmsg_type == SCM_CREDS) {
if (n_prev == NULL)
control = n->m_next;
else
n_prev->m_next = n->m_next;
n = m_free(n);
} else {
n_prev = n;
n = n->m_next;
}
}
/* Prepend it to the head. */
m->m_next = control;
return (m);
}
static struct unpcb *
fptounp(struct file *fp)
{
struct socket *so;
if (fp->f_type != DTYPE_SOCKET)
return (NULL);
if ((so = fp->f_data) == NULL)
return (NULL);
if (so->so_proto->pr_domain != &localdomain)
return (NULL);
return sotounpcb(so);
}
static void
unp_discard(struct file *fp)
{
unp_externalize_fp(fp);
(void) closef(fp, (struct thread *)NULL);
}
static void
unp_internalize_fp(struct file *fp)
{
struct unpcb *unp;
UNP_GLOBAL_WLOCK();
if ((unp = fptounp(fp)) != NULL) {
unp->unp_file = fp;
unp->unp_msgcount++;
}
fhold(fp);
unp_rights++;
UNP_GLOBAL_WUNLOCK();
}
static void
unp_externalize_fp(struct file *fp)
{
struct unpcb *unp;
UNP_GLOBAL_WLOCK();
if ((unp = fptounp(fp)) != NULL)
unp->unp_msgcount--;
unp_rights--;
UNP_GLOBAL_WUNLOCK();
}
/*
* unp_defer indicates whether additional work has been defered for a future
* pass through unp_gc(). It is thread local and does not require explicit
* synchronization.
*/
static int unp_marked;
static int unp_unreachable;
static void
unp_accessable(struct file *fp)
{
struct unpcb *unp;
if ((unp = fptounp(fp)) == NULL)
return;
if (unp->unp_gcflag & UNPGC_REF)
return;
unp->unp_gcflag &= ~UNPGC_DEAD;
unp->unp_gcflag |= UNPGC_REF;
unp_marked++;
}
static void
unp_gc_process(struct unpcb *unp)
{
struct socket *soa;
struct socket *so;
struct file *fp;
/* Already processed. */
if (unp->unp_gcflag & UNPGC_SCANNED)
return;
fp = unp->unp_file;
/*
* Check for a socket potentially in a cycle. It must be in a
* queue as indicated by msgcount, and this must equal the file
* reference count. Note that when msgcount is 0 the file is NULL.
*/
if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
unp->unp_gcflag |= UNPGC_DEAD;
unp_unreachable++;
return;
}
/*
* Mark all sockets we reference with RIGHTS.
*/
so = unp->unp_socket;
SOCKBUF_LOCK(&so->so_rcv);
unp_scan(so->so_rcv.sb_mb, unp_accessable);
SOCKBUF_UNLOCK(&so->so_rcv);
/*
* Mark all sockets in our accept queue.
*/
ACCEPT_LOCK();
TAILQ_FOREACH(soa, &so->so_comp, so_list) {
SOCKBUF_LOCK(&soa->so_rcv);
unp_scan(soa->so_rcv.sb_mb, unp_accessable);
SOCKBUF_UNLOCK(&soa->so_rcv);
}
ACCEPT_UNLOCK();
unp->unp_gcflag |= UNPGC_SCANNED;
}
static int unp_recycled;
SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, "");
static int unp_taskcount;
SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, "");
static void
unp_gc(__unused void *arg, int pending)
{
struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL };
struct unp_head **head;
struct file **unref;
struct unpcb *unp;
int i;
unp_taskcount++;
UNP_GLOBAL_RLOCK();
/*
* First clear all gc flags from previous runs.
*/
for (head = heads; *head != NULL; head++)
LIST_FOREACH(unp, *head, unp_link)
unp->unp_gcflag = 0;
/*
* Scan marking all reachable sockets with UNPGC_REF. Once a socket
* is reachable all of the sockets it references are reachable.
* Stop the scan once we do a complete loop without discovering
* a new reachable socket.
*/
do {
unp_unreachable = 0;
unp_marked = 0;
for (head = heads; *head != NULL; head++)
LIST_FOREACH(unp, *head, unp_link)
unp_gc_process(unp);
} while (unp_marked);
UNP_GLOBAL_RUNLOCK();
if (unp_unreachable == 0)
return;
/*
* Allocate space for a local list of dead unpcbs.
*/
unref = malloc(unp_unreachable * sizeof(struct file *),
M_TEMP, M_WAITOK);
/*
* Iterate looking for sockets which have been specifically marked
* as as unreachable and store them locally.
*/
UNP_GLOBAL_RLOCK();
for (i = 0, head = heads; *head != NULL; head++)
LIST_FOREACH(unp, *head, unp_link)
if (unp->unp_gcflag & UNPGC_DEAD) {
unref[i++] = unp->unp_file;
fhold(unp->unp_file);
KASSERT(unp->unp_file != NULL,
("unp_gc: Invalid unpcb."));
KASSERT(i <= unp_unreachable,
("unp_gc: incorrect unreachable count."));
}
UNP_GLOBAL_RUNLOCK();
/*
* Now flush all sockets, free'ing rights. This will free the
* struct files associated with these sockets but leave each socket
* with one remaining ref.
*/
for (i = 0; i < unp_unreachable; i++)
sorflush(unref[i]->f_data);
/*
* And finally release the sockets so they can be reclaimed.
*/
for (i = 0; i < unp_unreachable; i++)
fdrop(unref[i], NULL);
unp_recycled += unp_unreachable;
free(unref, M_TEMP);
}
void
unp_dispose(struct mbuf *m)
{
if (m)
unp_scan(m, unp_discard);
}
static void
unp_scan(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;
}
}
#ifdef DDB
static void
db_print_indent(int indent)
{
int i;
for (i = 0; i < indent; i++)
db_printf(" ");
}
static void
db_print_unpflags(int unp_flags)
{
int comma;
comma = 0;
if (unp_flags & UNP_HAVEPC) {
db_printf("%sUNP_HAVEPC", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_HAVEPCCACHED) {
db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_WANTCRED) {
db_printf("%sUNP_WANTCRED", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_CONNWAIT) {
db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_CONNECTING) {
db_printf("%sUNP_CONNECTING", comma ? ", " : "");
comma = 1;
}
if (unp_flags & UNP_BINDING) {
db_printf("%sUNP_BINDING", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_xucred(int indent, struct xucred *xu)
{
int comma, i;
db_print_indent(indent);
db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n",
xu->cr_version, xu->cr_uid, xu->cr_ngroups);
db_print_indent(indent);
db_printf("cr_groups: ");
comma = 0;
for (i = 0; i < xu->cr_ngroups; i++) {
db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
comma = 1;
}
db_printf("\n");
}
static void
db_print_unprefs(int indent, struct unp_head *uh)
{
struct unpcb *unp;
int counter;
counter = 0;
LIST_FOREACH(unp, uh, unp_reflink) {
if (counter % 4 == 0)
db_print_indent(indent);
db_printf("%p ", unp);
if (counter % 4 == 3)
db_printf("\n");
counter++;
}
if (counter != 0 && counter % 4 != 0)
db_printf("\n");
}
DB_SHOW_COMMAND(unpcb, db_show_unpcb)
{
struct unpcb *unp;
if (!have_addr) {
db_printf("usage: show unpcb <addr>\n");
return;
}
unp = (struct unpcb *)addr;
db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket,
unp->unp_vnode);
db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino,
unp->unp_conn);
db_printf("unp_refs:\n");
db_print_unprefs(2, &unp->unp_refs);
/* XXXRW: Would be nice to print the full address, if any. */
db_printf("unp_addr: %p\n", unp->unp_addr);
db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n",
unp->unp_cc, unp->unp_mbcnt,
(unsigned long long)unp->unp_gencnt);
db_printf("unp_flags: %x (", unp->unp_flags);
db_print_unpflags(unp->unp_flags);
db_printf(")\n");
db_printf("unp_peercred:\n");
db_print_xucred(2, &unp->unp_peercred);
db_printf("unp_refcount: %u\n", unp->unp_refcount);
}
#endif
Reference in New Issue View Git Blame Copy Permalink