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freebsd-dev/sys/netnatm/natm.c
Robert Watson 81158452be 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

762 lines
18 KiB
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Raw Blame History

/* $NetBSD: natm.c,v 1.5 1996/11/09 03:26:26 chuck Exp $ */
/*
*
* Copyright (c) 1996 Charles D. Cranor and Washington University.
* 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 Charles D. Cranor and
* Washington University.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* natm.c: native mode ATM access (both aal0 and aal5).
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_atm.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netnatm/natm.h>
static const u_long natm5_sendspace = 16*1024;
static const u_long natm5_recvspace = 16*1024;
static const u_long natm0_sendspace = 16*1024;
static const u_long natm0_recvspace = 16*1024;
/*
* user requests
*/
#ifdef FREEBSD_USRREQS
/*
* FreeBSD new usrreqs supersedes pr_usrreq.
*/
static int natm_usr_attach(struct socket *, int, d_thread_t *);
static int natm_usr_detach(struct socket *);
static int natm_usr_connect(struct socket *, struct sockaddr *, d_thread_t *);
static int natm_usr_disconnect(struct socket *);
static int natm_usr_shutdown(struct socket *);
static int natm_usr_send(struct socket *, int, struct mbuf *,
struct sockaddr *, struct mbuf *, d_thread_t *);
static int natm_usr_peeraddr(struct socket *, struct sockaddr **);
static int natm_usr_control(struct socket *, u_long, caddr_t,
struct ifnet *, d_thread_t *);
static int natm_usr_abort(struct socket *);
static int natm_usr_bind(struct socket *, struct sockaddr *, d_thread_t *);
static int natm_usr_sockaddr(struct socket *, struct sockaddr **);
static int
natm_usr_attach(struct socket *so, int proto, d_thread_t *p)
{
struct natmpcb *npcb;
int error = 0;
int s = SPLSOFTNET();
npcb = (struct natmpcb *)so->so_pcb;
if (npcb) {
error = EISCONN;
goto out;
}
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
if (proto == PROTO_NATMAAL5)
error = soreserve(so, natm5_sendspace, natm5_recvspace);
else
error = soreserve(so, natm0_sendspace, natm0_recvspace);
if (error)
goto out;
}
so->so_pcb = (caddr_t) (npcb = npcb_alloc(M_WAITOK));
npcb->npcb_socket = so;
out:
splx(s);
return (error);
}
static int
natm_usr_detach(struct socket *so)
{
struct natmpcb *npcb;
int error = 0;
int s = SPLSOFTNET();
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
/*
* we turn on 'drain' *before* we sofree.
*/
npcb_free(npcb, NPCB_DESTROY); /* drain */
ACCEPT_LOCK();
SOCK_LOCK(so);
so->so_pcb = NULL;
sotryfree(so);
out:
splx(s);
return (error);
}
static int
natm_usr_connect(struct socket *so, struct sockaddr *nam, d_thread_t *p)
{
struct natmpcb *npcb;
struct sockaddr_natm *snatm;
struct atmio_openvcc op;
struct ifnet *ifp;
int error = 0;
int s2, s = SPLSOFTNET();
int proto = so->so_proto->pr_protocol;
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
/*
* validate nam and npcb
*/
snatm = (struct sockaddr_natm *)nam;
if (snatm->snatm_len != sizeof(*snatm) ||
(npcb->npcb_flags & NPCB_FREE) == 0) {
error = EINVAL;
goto out;
}
if (snatm->snatm_family != AF_NATM) {
error = EAFNOSUPPORT;
goto out;
}
snatm->snatm_if[IFNAMSIZ - 1] = '\0'; /* XXX ensure null termination
since ifunit() uses strcmp */
/*
* convert interface string to ifp, validate.
*/
ifp = ifunit(snatm->snatm_if);
if (ifp == NULL || (ifp->if_flags & IFF_RUNNING) == 0) {
error = ENXIO;
goto out;
}
if (ifp->if_output != atm_output) {
error = EAFNOSUPPORT;
goto out;
}
/*
* register us with the NATM PCB layer
*/
if (npcb_add(npcb, ifp, snatm->snatm_vci, snatm->snatm_vpi) != npcb) {
error = EADDRINUSE;
goto out;
}
/*
* open the channel
*/
bzero(&op, sizeof(op));
op.rxhand = npcb;
op.param.flags = ATMIO_FLAG_PVC;
op.param.vpi = npcb->npcb_vpi;
op.param.vci = npcb->npcb_vci;
op.param.rmtu = op.param.tmtu = ifp->if_mtu;
op.param.aal = (proto == PROTO_NATMAAL5) ? ATMIO_AAL_5 : ATMIO_AAL_0;
op.param.traffic = ATMIO_TRAFFIC_UBR;
s2 = splimp();
if (ifp->if_ioctl == NULL ||
ifp->if_ioctl(ifp, SIOCATMOPENVCC, (caddr_t)&op) != 0) {
splx(s2);
npcb_free(npcb, NPCB_REMOVE);
error = EIO;
goto out;
}
splx(s2);
soisconnected(so);
out:
splx(s);
return (error);
}
static int
natm_usr_disconnect(struct socket *so)
{
struct natmpcb *npcb;
struct atmio_closevcc cl;
struct ifnet *ifp;
int error = 0;
int s2, s = SPLSOFTNET();
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
if ((npcb->npcb_flags & NPCB_CONNECTED) == 0) {
printf("natm: disconnected check\n");
error = EIO;
goto out;
}
ifp = npcb->npcb_ifp;
/*
* disable rx
*/
cl.vpi = npcb->npcb_vpi;
cl.vci = npcb->npcb_vci;
s2 = splimp();
if (ifp->if_ioctl != NULL)
ifp->if_ioctl(ifp, SIOCATMCLOSEVCC, (caddr_t)&cl);
splx(s2);
npcb_free(npcb, NPCB_REMOVE);
soisdisconnected(so);
out:
splx(s);
return (error);
}
static int
natm_usr_shutdown(struct socket *so)
{
socantsendmore(so);
return (0);
}
static int
natm_usr_send(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *nam, struct mbuf *control, d_thread_t *p)
{
struct natmpcb *npcb;
struct atm_pseudohdr *aph;
int error = 0;
int s = SPLSOFTNET();
int proto = so->so_proto->pr_protocol;
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
if (control && control->m_len) {
m_freem(control);
m_freem(m);
error = EINVAL;
goto out;
}
/*
* send the data. we must put an atm_pseudohdr on first
*/
M_PREPEND(m, sizeof(*aph), M_TRYWAIT);
if (m == NULL) {
error = ENOBUFS;
goto out;
}
aph = mtod(m, struct atm_pseudohdr *);
ATM_PH_VPI(aph) = npcb->npcb_vpi;
ATM_PH_SETVCI(aph, npcb->npcb_vci);
ATM_PH_FLAGS(aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
error = atm_output(npcb->npcb_ifp, m, NULL, NULL);
out:
splx(s);
return (error);
}
static int
natm_usr_peeraddr(struct socket *so, struct sockaddr **nam)
{
struct natmpcb *npcb;
struct sockaddr_natm *snatm, ssnatm;
int error = 0;
int s = SPLSOFTNET();
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
snatm = &ssnatm;
bzero(snatm, sizeof(*snatm));
snatm->snatm_len = sizeof(*snatm);
snatm->snatm_family = AF_NATM;
strlcpy(snatm->snatm_if, npcb->npcb_ifp->if_xname,
sizeof(snatm->snatm_if));
snatm->snatm_vci = npcb->npcb_vci;
snatm->snatm_vpi = npcb->npcb_vpi;
*nam = sodupsockaddr((struct sockaddr *)snatm, M_NOWAIT);
out:
splx(s);
return (error);
}
static int
natm_usr_control(struct socket *so, u_long cmd, caddr_t arg,
struct ifnet *ifp, d_thread_t *p)
{
struct natmpcb *npcb;
int error = 0;
int s = SPLSOFTNET();
npcb = (struct natmpcb *)so->so_pcb;
if (npcb == NULL) {
error = EINVAL;
goto out;
}
splx(s);
if (ifp == NULL || ifp->if_ioctl == NULL) {
error = EOPNOTSUPP;
goto out;
}
return ((*ifp->if_ioctl)(ifp, cmd, arg));
out:
splx(s);
return (error);
}
static int
natm_usr_abort(struct socket *so)
{
return (natm_usr_shutdown(so));
}
static int
natm_usr_bind(struct socket *so, struct sockaddr *nam, d_thread_t *p)
{
return (EOPNOTSUPP);
}
static int
natm_usr_sockaddr(struct socket *so, struct sockaddr **nam)
{
return (EOPNOTSUPP);
}
/* xxx - should be const */
struct pr_usrreqs natm_usrreqs = {
natm_usr_abort, pru_accept_notsupp, natm_usr_attach, natm_usr_bind,
natm_usr_connect, pru_connect2_notsupp, natm_usr_control,
natm_usr_detach, natm_usr_disconnect, pru_listen_notsupp,
natm_usr_peeraddr, pru_rcvd_notsupp, pru_rcvoob_notsupp,
natm_usr_send, pru_sense_null, natm_usr_shutdown,
natm_usr_sockaddr, sosend, soreceive, sopoll, pru_sosetlabel_null
};
#else /* !FREEBSD_USRREQS */
#if defined(__NetBSD__) || defined(__OpenBSD__)
int natm_usrreq(so, req, m, nam, control, p)
#elif defined(__FreeBSD__)
int natm_usrreq(so, req, m, nam, control)
#endif
struct socket *so;
int req;
struct mbuf *m, *nam, *control;
#if defined(__NetBSD__) || defined(__OpenBSD__)
struct proc *p;
#endif
{
int error = 0, s, s2;
struct natmpcb *npcb;
struct sockaddr_natm *snatm;
struct atm_pseudoioctl api;
struct atm_pseudohdr *aph;
struct atm_rawioctl ario;
struct ifnet *ifp;
int proto = so->so_proto->pr_protocol;
s = SPLSOFTNET();
npcb = (struct natmpcb *) so->so_pcb;
if (npcb == NULL && req != PRU_ATTACH) {
error = EINVAL;
goto done;
}
switch (req) {
case PRU_ATTACH: /* attach protocol to up */
if (npcb) {
error = EISCONN;
break;
}
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
if (proto == PROTO_NATMAAL5)
error = soreserve(so, natm5_sendspace, natm5_recvspace);
else
error = soreserve(so, natm0_sendspace, natm0_recvspace);
if (error)
break;
}
so->so_pcb = (caddr_t) (npcb = npcb_alloc(M_WAITOK));
npcb->npcb_socket = so;
break;
case PRU_DETACH: /* detach protocol from up */
/*
* we turn on 'drain' *before* we sofree.
*/
npcb_free(npcb, NPCB_DESTROY); /* drain */
ACCEPT_LOCK();
SOCK_LOCK(so);
so->so_pcb = NULL;
sotryfree(so);
break;
case PRU_CONNECT: /* establish connection to peer */
/*
* validate nam and npcb
*/
if (nam->m_len != sizeof(*snatm)) {
error = EINVAL;
break;
}
snatm = mtod(nam, struct sockaddr_natm *);
if (snatm->snatm_len != sizeof(*snatm) ||
(npcb->npcb_flags & NPCB_FREE) == 0) {
error = EINVAL;
break;
}
if (snatm->snatm_family != AF_NATM) {
error = EAFNOSUPPORT;
break;
}
snatm->snatm_if[IFNAMSIZ-1] = '\0'; /* XXX ensure null termination
since ifunit() uses strcmp */
/*
* convert interface string to ifp, validate.
*/
ifp = ifunit(snatm->snatm_if);
if (ifp == NULL || (ifp->if_flags & IFF_RUNNING) == 0) {
error = ENXIO;
break;
}
if (ifp->if_output != atm_output) {
error = EAFNOSUPPORT;
break;
}
/*
* register us with the NATM PCB layer
*/
if (npcb_add(npcb, ifp, snatm->snatm_vci, snatm->snatm_vpi) != npcb) {
error = EADDRINUSE;
break;
}
/*
* enable rx
*/
ATM_PH_FLAGS(&api.aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
api.rxhand = npcb;
s2 = splimp();
if (ifp->if_ioctl == NULL ||
ifp->if_ioctl(ifp, SIOCATMENA, (caddr_t) &api) != 0) {
splx(s2);
npcb_free(npcb, NPCB_REMOVE);
error = EIO;
break;
}
splx(s2);
soisconnected(so);
break;
case PRU_DISCONNECT: /* disconnect from peer */
if ((npcb->npcb_flags & NPCB_CONNECTED) == 0) {
printf("natm: disconnected check\n");
error = EIO;
break;
}
ifp = npcb->npcb_ifp;
/*
* disable rx
*/
ATM_PH_FLAGS(&api.aph) = ATM_PH_AAL5;
ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
api.rxhand = npcb;
s2 = splimp();
if (ifp->if_ioctl != NULL)
ifp->if_ioctl(ifp, SIOCATMDIS, (caddr_t) &api);
splx(s2);
npcb_free(npcb, NPCB_REMOVE);
soisdisconnected(so);
break;
case PRU_SHUTDOWN: /* won't send any more data */
socantsendmore(so);
break;
case PRU_SEND: /* send this data */
if (control && control->m_len) {
m_freem(control);
m_freem(m);
error = EINVAL;
break;
}
/*
* send the data. we must put an atm_pseudohdr on first
*/
M_PREPEND(m, sizeof(*aph), M_TRYWAIT);
if (m == NULL) {
error = ENOBUFS;
break;
}
aph = mtod(m, struct atm_pseudohdr *);
ATM_PH_VPI(aph) = npcb->npcb_vpi;
ATM_PH_SETVCI(aph, npcb->npcb_vci);
ATM_PH_FLAGS(aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
error = atm_output(npcb->npcb_ifp, m, NULL, NULL);
break;
case PRU_SENSE: /* return status into m */
/* return zero? */
break;
case PRU_PEERADDR: /* fetch peer's address */
snatm = mtod(nam, struct sockaddr_natm *);
bzero(snatm, sizeof(*snatm));
nam->m_len = snatm->snatm_len = sizeof(*snatm);
snatm->snatm_family = AF_NATM;
#if defined(__NetBSD__) || defined(__OpenBSD__)
bcopy(npcb->npcb_ifp->if_xname, snatm->snatm_if, sizeof(snatm->snatm_if));
#elif defined(__FreeBSD__)
snprintf(snatm->snatm_if, sizeof(snatm->snatm_if),
"%s%d", npcb->npcb_ifp->if_name, npcb->npcb_ifp->if_unit);
#endif
snatm->snatm_vci = npcb->npcb_vci;
snatm->snatm_vpi = npcb->npcb_vpi;
break;
case PRU_CONTROL: /* control operations on protocol */
/*
* raw atm ioctl. comes in as a SIOCRAWATM. we convert it to
* SIOCXRAWATM and pass it to the driver.
*/
if ((u_long)m == SIOCRAWATM) {
if (npcb->npcb_ifp == NULL) {
error = ENOTCONN;
break;
}
ario.npcb = npcb;
ario.rawvalue = *((int *)nam);
error = npcb->npcb_ifp->if_ioctl(npcb->npcb_ifp,
SIOCXRAWATM, (caddr_t) &ario);
if (!error) {
if (ario.rawvalue)
npcb->npcb_flags |= NPCB_RAW;
else
npcb->npcb_flags &= ~(NPCB_RAW);
}
break;
}
error = EOPNOTSUPP;
break;
case PRU_BIND: /* bind socket to address */
case PRU_LISTEN: /* listen for connection */
case PRU_ACCEPT: /* accept connection from peer */
case PRU_CONNECT2: /* connect two sockets */
case PRU_ABORT: /* abort (fast DISCONNECT, DETATCH) */
/* (only happens if LISTEN socket) */
case PRU_RCVD: /* have taken data; more room now */
case PRU_FASTTIMO: /* 200ms timeout */
case PRU_SLOWTIMO: /* 500ms timeout */
case PRU_RCVOOB: /* retrieve out of band data */
case PRU_SENDOOB: /* send out of band data */
case PRU_PROTORCV: /* receive from below */
case PRU_PROTOSEND: /* send to below */
case PRU_SOCKADDR: /* fetch socket's address */
#ifdef DIAGNOSTIC
printf("natm: PRU #%d unsupported\n", req);
#endif
error = EOPNOTSUPP;
break;
default: panic("natm usrreq");
}
done:
splx(s);
return(error);
}
#endif /* !FREEBSD_USRREQS */
/*
* natmintr: splsoftnet interrupt
*
* note: we expect a socket pointer in rcvif rather than an interface
* pointer. we can get the interface pointer from the so's PCB if
* we really need it.
*/
void
natmintr(struct mbuf *m)
{
int s;
struct socket *so;
struct natmpcb *npcb;
GIANT_REQUIRED;
#ifdef DIAGNOSTIC
M_ASSERTPKTHDR(m);
#endif
npcb = (struct natmpcb *)m->m_pkthdr.rcvif; /* XXX: overloaded */
so = npcb->npcb_socket;
s = splimp(); /* could have atm devs @ different levels */
npcb->npcb_inq--;
splx(s);
if (npcb->npcb_flags & NPCB_DRAIN) {
m_freem(m);
if (npcb->npcb_inq == 0)
FREE(npcb, M_PCB); /* done! */
return;
}
if (npcb->npcb_flags & NPCB_FREE) {
m_freem(m); /* drop */
return;
}
#ifdef NEED_TO_RESTORE_IFP
m->m_pkthdr.rcvif = npcb->npcb_ifp;
#else
#ifdef DIAGNOSTIC
m->m_pkthdr.rcvif = NULL; /* null it out to be safe */
#endif
#endif
if (sbspace(&so->so_rcv) > m->m_pkthdr.len) {
#ifdef NATM_STAT
natm_sookcnt++;
natm_sookbytes += m->m_pkthdr.len;
#endif
sbappendrecord(&so->so_rcv, m);
sorwakeup(so);
} else {
#ifdef NATM_STAT
natm_sodropcnt++;
natm_sodropbytes += m->m_pkthdr.len;
#endif
m_freem(m);
}
}
/*
* natm0_sysctl: not used, but here in case we want to add something
* later...
*/
int
natm0_sysctl(SYSCTL_HANDLER_ARGS)
{
/* All sysctl names at this level are terminal. */
return (ENOENT);
}
/*
* natm5_sysctl: not used, but here in case we want to add something
* later...
*/
int
natm5_sysctl(SYSCTL_HANDLER_ARGS)
{
/* All sysctl names at this level are terminal. */
return (ENOENT);
}
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