freebsd-skq/sys/netipx/ipx_input.c
Robert Watson 59dd72d040 Remove NETISR_MPSAFE, which allows specific netisr handlers to be directly
dispatched without Giant, and add NETISR_FORCEQUEUE, which allows specific
netisr handlers to always be dispatched via a queue (deferred).  Mark the
usb and if_ppp netisr handlers as NETISR_FORCEQUEUE, and explicitly
acquire Giant in those handlers.

Previously, any netisr handler not marked NETISR_MPSAFE would necessarily
run deferred and with Giant acquired.  This change removes Giant
scaffolding from the netisr infrastructure, but NETISR_FORCEQUEUE allows
non-MPSAFE handlers to continue to force deferred dispatch so as to avoid
lock order reversals between their acqusition of Giant and any calling
context.

It is likely we will be able to remove NETISR_FORCEQUEUE once
IFF_NEEDSGIANT is removed, as non-MPSAFE usb and if_ppp drivers will no
longer be supported.

Reviewed by:	bz
MFC after:	1 month
X-MFC note:	We can't remove NETISR_MPSAFE from stable/7 for KPI reasons,
		but the rest can go back.
2008-07-04 00:21:38 +00:00

503 lines
13 KiB
C

/*-
* Copyright (c) 1984, 1985, 1986, 1987, 1993
* The Regents of the University of California.
* Copyright (c) 2004-2005 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.
*
* Copyright (c) 1995, Mike Mitchell
* 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_input.c
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/random.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <netipx/ipx.h>
#include <netipx/spx.h>
#include <netipx/ipx_if.h>
#include <netipx/ipx_pcb.h>
#include <netipx/ipx_var.h>
int ipxcksum = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
&ipxcksum, 0, "");
static int ipxprintfs = 0; /* printing forwarding information */
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
&ipxprintfs, 0, "");
static int ipxforwarding = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
&ipxforwarding, 0, "");
static int ipxnetbios = 0;
SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
&ipxnetbios, 0, "");
const union ipx_net ipx_zeronet;
const union ipx_host ipx_zerohost;
const union ipx_net ipx_broadnet = { .s_net[0] = 0xffff,
.s_net[1] = 0xffff };
const union ipx_host ipx_broadhost = { .s_host[0] = 0xffff,
.s_host[1] = 0xffff,
.s_host[2] = 0xffff };
struct ipxstat ipxstat;
struct sockaddr_ipx ipx_netmask, ipx_hostmask;
/*
* IPX protocol control block (pcb) lists.
*/
struct mtx ipxpcb_list_mtx;
struct ipxpcbhead ipxpcb_list;
struct ipxpcbhead ipxrawpcb_list;
static int ipxqmaxlen = IFQ_MAXLEN;
static struct ifqueue ipxintrq;
long ipx_pexseq; /* Locked with ipxpcb_list_mtx. */
static int ipx_do_route(struct ipx_addr *src, struct route *ro);
static void ipx_undo_route(struct route *ro);
static void ipx_forward(struct mbuf *m);
static void ipxintr(struct mbuf *m);
/*
* IPX initialization.
*/
void
ipx_init(void)
{
read_random(&ipx_pexseq, sizeof ipx_pexseq);
LIST_INIT(&ipxpcb_list);
LIST_INIT(&ipxrawpcb_list);
IPX_LIST_LOCK_INIT();
ipx_netmask.sipx_len = 6;
ipx_netmask.sipx_addr.x_net = ipx_broadnet;
ipx_hostmask.sipx_len = 12;
ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
ipxintrq.ifq_maxlen = ipxqmaxlen;
mtx_init(&ipxintrq.ifq_mtx, "ipx_inq", NULL, MTX_DEF);
netisr_register(NETISR_IPX, ipxintr, &ipxintrq, 0);
}
/*
* IPX input routine. Pass to next level.
*/
static void
ipxintr(struct mbuf *m)
{
struct ipx *ipx;
struct ipxpcb *ipxp;
struct ipx_ifaddr *ia;
int len;
/*
* If no IPX addresses have been set yet but the interfaces
* are receiving, can't do anything with incoming packets yet.
*/
if (ipx_ifaddr == NULL) {
m_freem(m);
return;
}
ipxstat.ipxs_total++;
if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
(m = m_pullup(m, sizeof(struct ipx))) == NULL) {
ipxstat.ipxs_toosmall++;
return;
}
/*
* Give any raw listeners a crack at the packet
*/
IPX_LIST_LOCK();
LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
if (m1 != NULL) {
IPX_LOCK(ipxp);
ipx_input(m1, ipxp);
IPX_UNLOCK(ipxp);
}
}
IPX_LIST_UNLOCK();
ipx = mtod(m, struct ipx *);
len = ntohs(ipx->ipx_len);
/*
* Check that the amount of data in the buffers
* is as at least much as the IPX header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < len) {
ipxstat.ipxs_tooshort++;
m_freem(m);
return;
}
if (m->m_pkthdr.len > len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = len;
m->m_pkthdr.len = len;
} else
m_adj(m, len - m->m_pkthdr.len);
}
if (ipxcksum && ipx->ipx_sum != 0xffff) {
if (ipx->ipx_sum != ipx_cksum(m, len)) {
ipxstat.ipxs_badsum++;
m_freem(m);
return;
}
}
/*
* Propagated (Netbios) packets (type 20) has to be handled
* different. :-(
*/
if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
if (ipxnetbios) {
ipx_output_type20(m);
return;
} else {
m_freem(m);
return;
}
}
/*
* Is this a directed broadcast?
*/
if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
(!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
(!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
(!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
/*
* If it is a broadcast to the net where it was
* received from, treat it as ours.
*/
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
ipx_neteq(ia->ia_addr.sipx_addr,
ipx->ipx_dna))
goto ours;
/*
* Look to see if I need to eat this packet.
* Algorithm is to forward all young packets
* and prematurely age any packets which will
* by physically broadcasted.
* Any very old packets eaten without forwarding
* would die anyway.
*
* Suggestion of Bill Nesheim, Cornell U.
*/
if (ipx->ipx_tc < IPX_MAXHOPS) {
ipx_forward(m);
return;
}
}
/*
* Is this our packet? If not, forward.
*/
} else {
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
(ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
break;
if (ia == NULL) {
ipx_forward(m);
return;
}
}
ours:
/*
* Locate pcb for datagram.
*/
IPX_LIST_LOCK();
ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
/*
* Switch out to protocol's input routine.
*/
if (ipxp != NULL) {
ipxstat.ipxs_delivered++;
if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
switch (ipx->ipx_pt) {
case IPXPROTO_SPX:
IPX_LOCK(ipxp);
/* Will release both locks. */
spx_input(m, ipxp);
return;
}
IPX_LOCK(ipxp);
ipx_input(m, ipxp);
IPX_UNLOCK(ipxp);
} else
m_freem(m);
IPX_LIST_UNLOCK();
}
void
ipx_ctlinput(cmd, arg_as_sa, dummy)
int cmd;
struct sockaddr *arg_as_sa; /* XXX should be swapped with dummy */
void *dummy;
{
/* Currently, nothing. */
}
/*
* Forward a packet. If some error occurs drop the packet. IPX don't
* have a way to return errors to the sender.
*/
static struct route ipx_droute;
static struct route ipx_sroute;
static void
ipx_forward(struct mbuf *m)
{
struct ipx *ipx = mtod(m, struct ipx *);
int error;
int agedelta = 1;
int flags = IPX_FORWARDING;
int ok_there = 0;
int ok_back = 0;
if (ipxforwarding == 0) {
/* can't tell difference between net and host */
ipxstat.ipxs_cantforward++;
m_freem(m);
goto cleanup;
}
ipx->ipx_tc++;
if (ipx->ipx_tc > IPX_MAXHOPS) {
ipxstat.ipxs_cantforward++;
m_freem(m);
goto cleanup;
}
if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
/*
* Here we think about forwarding broadcast packets,
* so we try to insure that it doesn't go back out
* on the interface it came in on. Also, if we
* are going to physically broadcast this, let us
* age the packet so we can eat it safely the second time around.
*/
if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
struct ifnet *ifp;
if (ia != NULL) {
/* I'm gonna hafta eat this packet */
agedelta += IPX_MAXHOPS - ipx->ipx_tc;
ipx->ipx_tc = IPX_MAXHOPS;
}
if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
/* error = ENETUNREACH; He'll never get it! */
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
if (ipx_droute.ro_rt &&
(ifp = ipx_droute.ro_rt->rt_ifp) &&
ipx_sroute.ro_rt &&
(ifp != ipx_sroute.ro_rt->rt_ifp)) {
flags |= IPX_ALLOWBROADCAST;
} else {
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
}
/*
* We don't need to recompute checksum because ipx_tc field
* is ignored by checksum calculation routine, however
* it may be desirable to reset checksum if ipxcksum == 0
*/
#if 0
if (!ipxcksum)
ipx->ipx_sum = 0xffff;
#endif
error = ipx_outputfl(m, &ipx_droute, flags);
if (error == 0) {
ipxstat.ipxs_forward++;
if (ipxprintfs) {
printf("forward: ");
ipx_printhost(&ipx->ipx_sna);
printf(" to ");
ipx_printhost(&ipx->ipx_dna);
printf(" hops %d\n", ipx->ipx_tc);
}
}
cleanup:
if (ok_there)
ipx_undo_route(&ipx_droute);
if (ok_back)
ipx_undo_route(&ipx_sroute);
}
static int
ipx_do_route(struct ipx_addr *src, struct route *ro)
{
struct sockaddr_ipx *dst;
bzero((caddr_t)ro, sizeof(*ro));
dst = (struct sockaddr_ipx *)&ro->ro_dst;
dst->sipx_len = sizeof(*dst);
dst->sipx_family = AF_IPX;
dst->sipx_addr = *src;
dst->sipx_addr.x_port = 0;
rtalloc_ign(ro, 0);
if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
return (0);
}
ro->ro_rt->rt_use++;
return (1);
}
static void
ipx_undo_route(struct route *ro)
{
if (ro->ro_rt != NULL) {
RTFREE(ro->ro_rt);
}
}
/*
* XXXRW: This code should be run in its own netisr dispatch to avoid a call
* back into the socket code from the IPX output path.
*/
void
ipx_watch_output(struct mbuf *m, struct ifnet *ifp)
{
struct ipxpcb *ipxp;
struct ifaddr *ifa;
struct ipx_ifaddr *ia;
/*
* Give any raw listeners a crack at the packet
*/
IPX_LIST_LOCK();
LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
if (m0 != NULL) {
struct ipx *ipx;
M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
if (m0 == NULL)
continue;
ipx = mtod(m0, struct ipx *);
ipx->ipx_sna.x_net = ipx_zeronet;
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ifp == ia->ia_ifp)
break;
if (ia == NULL)
ipx->ipx_sna.x_host = ipx_zerohost;
else
ipx->ipx_sna.x_host =
ia->ia_addr.sipx_addr.x_host;
if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_IPX) {
ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
break;
}
}
ipx->ipx_len = ntohl(m0->m_pkthdr.len);
IPX_LOCK(ipxp);
ipx_input(m0, ipxp);
IPX_UNLOCK(ipxp);
}
}
IPX_LIST_UNLOCK();
}