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freebsd-skq/sys/netipx/ipx_pcb.c
rwatson 4b81ce6dd2 Push acquisition of the accept mutex out of sofree() into the caller 
(sorele()/sotryfree()):

- This permits the caller to acquire the accept mutex before the socket
  mutex, avoiding sofree() having to drop the socket mutex and re-order,
  which could lead to races permitting more than one thread to enter
  sofree() after a socket is ready to be free'd.

- This also covers clearing of the so_pcb weak socket reference from
  the protocol to the socket, preventing races in clearing and
  evaluation of the reference such that sofree() might be called more
  than once on the same socket.

This appears to close a race I was able to easily trigger by repeatedly
opening and resetting TCP connections to a host, in which the
tcp_close() code called as a result of the RST raced with the close()
of the accepted socket in the user process resulting in simultaneous
attempts to de-allocate the same socket.  The new locking increases
the overhead for operations that may potentially free the socket, so we
will want to revise the synchronization strategy here as we normalize
the reference counting model for sockets.  The use of the accept mutex
in freeing of sockets that are not listen sockets is primarily
motivated by the potential need to remove the socket from the
incomplete connection queue on its parent (listen) socket, so cleaning
up the reference model here may allow us to substantially weaken the
synchronization requirements.

RELENG_5_3 candidate.

MFC after:	3 days
Reviewed by:	dwhite
Discussed with:	gnn, dwhite, green
Reported by:	Marc UBM Bocklet <ubm at u-boot-man dot de>
Reported by:	Vlad <marchenko at gmail dot com>
2004-10-18 22:19:43 +00:00

409 lines
11 KiB
C
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/*
* Copyright (c) 1995, Mike Mitchell
* Copyright (c) 1984, 1985, 1986, 1987, 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)ipx_pcb.c
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <net/if.h>
#include <net/route.h>
#include <netipx/ipx.h>
#include <netipx/ipx_if.h>
#include <netipx/ipx_pcb.h>
#include <netipx/ipx_var.h>
static struct ipx_addr zeroipx_addr;
int
ipx_pcballoc(so, head, td)
struct socket *so;
struct ipxpcb *head;
struct thread *td;
{
register struct ipxpcb *ipxp;
MALLOC(ipxp, struct ipxpcb *, sizeof *ipxp, M_PCB, M_NOWAIT | M_ZERO);
if (ipxp == NULL)
return (ENOBUFS);
ipxp->ipxp_socket = so;
if (ipxcksum)
ipxp->ipxp_flags |= IPXP_CHECKSUM;
insque(ipxp, head);
so->so_pcb = (caddr_t)ipxp;
return (0);
}
int
ipx_pcbbind(ipxp, nam, td)
register struct ipxpcb *ipxp;
struct sockaddr *nam;
struct thread *td;
{
register struct sockaddr_ipx *sipx;
u_short lport = 0;
if (ipxp->ipxp_lport || !ipx_nullhost(ipxp->ipxp_laddr))
return (EINVAL);
if (nam == NULL)
goto noname;
sipx = (struct sockaddr_ipx *)nam;
if (!ipx_nullhost(sipx->sipx_addr)) {
int tport = sipx->sipx_port;
sipx->sipx_port = 0; /* yech... */
if (ifa_ifwithaddr((struct sockaddr *)sipx) == 0)
return (EADDRNOTAVAIL);
sipx->sipx_port = tport;
}
lport = sipx->sipx_port;
if (lport) {
u_short aport = ntohs(lport);
int error;
if (aport < IPXPORT_RESERVED &&
td != NULL && (error = suser(td)) != 0)
return (error);
if (ipx_pcblookup(&zeroipx_addr, lport, 0))
return (EADDRINUSE);
}
ipxp->ipxp_laddr = sipx->sipx_addr;
noname:
if (lport == 0)
do {
ipxpcb.ipxp_lport++;
if ((ipxpcb.ipxp_lport < IPXPORT_RESERVED) ||
(ipxpcb.ipxp_lport >= IPXPORT_WELLKNOWN))
ipxpcb.ipxp_lport = IPXPORT_RESERVED;
lport = htons(ipxpcb.ipxp_lport);
} while (ipx_pcblookup(&zeroipx_addr, lport, 0));
ipxp->ipxp_lport = lport;
return (0);
}
/*
* Connect from a socket to a specified address.
* Both address and port must be specified in argument sipx.
* If don't have a local address for this socket yet,
* then pick one.
*/
int
ipx_pcbconnect(ipxp, nam, td)
struct ipxpcb *ipxp;
struct sockaddr *nam;
struct thread *td;
{
struct ipx_ifaddr *ia;
register struct sockaddr_ipx *sipx = (struct sockaddr_ipx *)nam;
register struct ipx_addr *dst;
register struct route *ro;
struct ifnet *ifp;
ia = NULL;
if (sipx->sipx_family != AF_IPX)
return (EAFNOSUPPORT);
if (sipx->sipx_port == 0 || ipx_nullhost(sipx->sipx_addr))
return (EADDRNOTAVAIL);
/*
* If we haven't bound which network number to use as ours,
* we will use the number of the outgoing interface.
* This depends on having done a routing lookup, which
* we will probably have to do anyway, so we might
* as well do it now. On the other hand if we are
* sending to multiple destinations we may have already
* done the lookup, so see if we can use the route
* from before. In any case, we only
* chose a port number once, even if sending to multiple
* destinations.
*/
ro = &ipxp->ipxp_route;
dst = &satoipx_addr(ro->ro_dst);
if (ipxp->ipxp_socket->so_options & SO_DONTROUTE)
goto flush;
if (!ipx_neteq(ipxp->ipxp_lastdst, sipx->sipx_addr))
goto flush;
if (!ipx_hosteq(ipxp->ipxp_lastdst, sipx->sipx_addr)) {
if (ro->ro_rt != NULL && !(ro->ro_rt->rt_flags & RTF_HOST)) {
/* can patch route to avoid rtalloc */
*dst = sipx->sipx_addr;
} else {
flush:
if (ro->ro_rt != NULL)
RTFREE(ro->ro_rt);
ro->ro_rt = NULL;
}
}/* else cached route is ok; do nothing */
ipxp->ipxp_lastdst = sipx->sipx_addr;
if ((ipxp->ipxp_socket->so_options & SO_DONTROUTE) == 0 && /*XXX*/
(ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL)) {
/* No route yet, so try to acquire one */
ro->ro_dst.sa_family = AF_IPX;
ro->ro_dst.sa_len = sizeof(ro->ro_dst);
*dst = sipx->sipx_addr;
dst->x_port = 0;
rtalloc(ro);
}
if (ipx_neteqnn(ipxp->ipxp_laddr.x_net, ipx_zeronet)) {
/*
* If route is known or can be allocated now,
* our src addr is taken from the i/f, else punt.
*/
/*
* If we found a route, use the address
* corresponding to the outgoing interface
*/
if (ro->ro_rt != NULL && (ifp = ro->ro_rt->rt_ifp) != NULL)
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ia->ia_ifp == ifp)
break;
if (ia == NULL) {
u_short fport = sipx->sipx_addr.x_port;
sipx->sipx_addr.x_port = 0;
ia = (struct ipx_ifaddr *)
ifa_ifwithdstaddr((struct sockaddr *)sipx);
sipx->sipx_addr.x_port = fport;
if (ia == NULL)
ia = ipx_iaonnetof(&sipx->sipx_addr);
if (ia == NULL)
ia = ipx_ifaddr;
if (ia == NULL)
return (EADDRNOTAVAIL);
}
ipxp->ipxp_laddr.x_net = satoipx_addr(ia->ia_addr).x_net;
}
if (ipx_nullhost(ipxp->ipxp_laddr)) {
/*
* If route is known or can be allocated now,
* our src addr is taken from the i/f, else punt.
*/
/*
* If we found a route, use the address
* corresponding to the outgoing interface
*/
if (ro->ro_rt != NULL && (ifp = ro->ro_rt->rt_ifp) != NULL)
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ia->ia_ifp == ifp)
break;
if (ia == NULL) {
u_short fport = sipx->sipx_addr.x_port;
sipx->sipx_addr.x_port = 0;
ia = (struct ipx_ifaddr *)
ifa_ifwithdstaddr((struct sockaddr *)sipx);
sipx->sipx_addr.x_port = fport;
if (ia == NULL)
ia = ipx_iaonnetof(&sipx->sipx_addr);
if (ia == NULL)
ia = ipx_ifaddr;
if (ia == NULL)
return (EADDRNOTAVAIL);
}
ipxp->ipxp_laddr.x_host = satoipx_addr(ia->ia_addr).x_host;
}
if (ipx_pcblookup(&sipx->sipx_addr, ipxp->ipxp_lport, 0))
return (EADDRINUSE);
if (ipxp->ipxp_lport == 0)
ipx_pcbbind(ipxp, (struct sockaddr *)NULL, td);
/* XXX just leave it zero if we can't find a route */
ipxp->ipxp_faddr = sipx->sipx_addr;
/* Includes ipxp->ipxp_fport = sipx->sipx_port; */
return (0);
}
void
ipx_pcbdisconnect(ipxp)
struct ipxpcb *ipxp;
{
ipxp->ipxp_faddr = zeroipx_addr;
if (ipxp->ipxp_socket->so_state & SS_NOFDREF)
ipx_pcbdetach(ipxp);
}
void
ipx_pcbdetach(ipxp)
struct ipxpcb *ipxp;
{
struct socket *so = ipxp->ipxp_socket;
ACCEPT_LOCK();
SOCK_LOCK(so);
so->so_pcb = 0;
sotryfree(so);
if (ipxp->ipxp_route.ro_rt != NULL)
rtfree(ipxp->ipxp_route.ro_rt);
remque(ipxp);
FREE(ipxp, M_PCB);
}
void
ipx_setsockaddr(ipxp, nam)
register struct ipxpcb *ipxp;
struct sockaddr **nam;
{
struct sockaddr_ipx *sipx, ssipx;
sipx = &ssipx;
bzero((caddr_t)sipx, sizeof(*sipx));
sipx->sipx_len = sizeof(*sipx);
sipx->sipx_family = AF_IPX;
sipx->sipx_addr = ipxp->ipxp_laddr;
*nam = sodupsockaddr((struct sockaddr *)sipx, M_NOWAIT);
}
void
ipx_setpeeraddr(ipxp, nam)
register struct ipxpcb *ipxp;
struct sockaddr **nam;
{
struct sockaddr_ipx *sipx, ssipx;
sipx = &ssipx;
bzero((caddr_t)sipx, sizeof(*sipx));
sipx->sipx_len = sizeof(*sipx);
sipx->sipx_family = AF_IPX;
sipx->sipx_addr = ipxp->ipxp_faddr;
*nam = sodupsockaddr((struct sockaddr *)sipx, M_NOWAIT);
}
/*
* Pass some notification to all connections of a protocol
* associated with address dst. Call the
* protocol specific routine to handle each connection.
* Also pass an extra paramter via the ipxpcb. (which may in fact
* be a parameter list!)
*/
void
ipx_pcbnotify(dst, errno, notify, param)
register struct ipx_addr *dst;
int errno;
void (*notify)(struct ipxpcb *);
long param;
{
register struct ipxpcb *ipxp, *oinp;
int s = splimp();
for (ipxp = (&ipxpcb)->ipxp_next; ipxp != (&ipxpcb);) {
if (!ipx_hosteq(*dst,ipxp->ipxp_faddr)) {
next:
ipxp = ipxp->ipxp_next;
continue;
}
if (ipxp->ipxp_socket == 0)
goto next;
if (errno)
ipxp->ipxp_socket->so_error = errno;
oinp = ipxp;
ipxp = ipxp->ipxp_next;
oinp->ipxp_notify_param = param;
(*notify)(oinp);
}
splx(s);
}
#ifdef notdef
/*
* After a routing change, flush old routing
* and allocate a (hopefully) better one.
*/
ipx_rtchange(ipxp)
struct ipxpcb *ipxp;
{
if (ipxp->ipxp_route.ro_rt != NULL) {
rtfree(ipxp->ipxp_route.ro_rt);
ipxp->ipxp_route.ro_rt = NULL;
/*
* A new route can be allocated the next time
* output is attempted.
*/
}
/* SHOULD NOTIFY HIGHER-LEVEL PROTOCOLS */
}
#endif
struct ipxpcb *
ipx_pcblookup(faddr, lport, wildp)
struct ipx_addr *faddr;
u_short lport;
int wildp;
{
register struct ipxpcb *ipxp, *match = 0;
int matchwild = 3, wildcard;
u_short fport;
fport = faddr->x_port;
for (ipxp = (&ipxpcb)->ipxp_next; ipxp != (&ipxpcb); ipxp = ipxp->ipxp_next) {
if (ipxp->ipxp_lport != lport)
continue;
wildcard = 0;
if (ipx_nullhost(ipxp->ipxp_faddr)) {
if (!ipx_nullhost(*faddr))
wildcard++;
} else {
if (ipx_nullhost(*faddr))
wildcard++;
else {
if (!ipx_hosteq(ipxp->ipxp_faddr, *faddr))
continue;
if (ipxp->ipxp_fport != fport) {
if (ipxp->ipxp_fport != 0)
continue;
else
wildcard++;
}
}
}
if (wildcard && wildp == 0)
continue;
if (wildcard < matchwild) {
match = ipxp;
matchwild = wildcard;
if (wildcard == 0)
break;
}
}
return (match);
}
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