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freebsd-dev/sys/netatalk/ddp_input.c
Robert Watson 2642bf60f7 Use queue(9) instead of hand-crafted link lists for the global netatalk 
address list.  Generally follow the style and convention of similar parts
in netinet.

MFC after:	6 weeks
2009-06-24 21:36:09 +00:00

441 lines
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/*-
* Copyright (c) 2004-2009 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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) 1990, 1994 Regents of The University of Michigan.
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation, and that the name of The University
* of Michigan not be used in advertising or publicity pertaining to
* distribution of the software without specific, written prior
* permission. This software is supplied as is without expressed or
* implied warranties of any kind.
*
* This product includes software developed by the University of
* California, Berkeley and its contributors.
*
* Research Systems Unix Group
* The University of Michigan
* c/o Wesley Craig
* 535 W. William Street
* Ann Arbor, Michigan
* +1-313-764-2278
* netatalk@umich.edu
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <net/if.h>
#include <net/route.h>
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/ddp.h>
#include <netatalk/ddp_var.h>
#include <netatalk/ddp_pcb.h>
#include <netatalk/at_extern.h>
#include <security/mac/mac_framework.h>
static volatile int ddp_forward = 1;
static volatile int ddp_firewall = 0;
static struct ddpstat ddpstat;
static struct route forwro;
static void ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int);
/*
* Could probably merge these two code segments a little better...
*/
void
at2intr(struct mbuf *m)
{
/*
* Phase 2 packet handling .
*/
ddp_input(m, m->m_pkthdr.rcvif, NULL, 2);
}
void
at1intr(struct mbuf *m)
{
struct elaphdr *elhp, elh;
/*
* Phase 1 packet handling
*/
if (m->m_len < SZ_ELAPHDR && ((m = m_pullup(m, SZ_ELAPHDR)) ==
NULL)) {
ddpstat.ddps_tooshort++;
return;
}
/*
* This seems a little dubious, but I don't know phase 1 so leave it.
*/
elhp = mtod(m, struct elaphdr *);
m_adj(m, SZ_ELAPHDR);
if (elhp->el_type != ELAP_DDPEXTEND) {
bcopy((caddr_t)elhp, (caddr_t)&elh, SZ_ELAPHDR);
ddp_input(m, m->m_pkthdr.rcvif, &elh, 1);
} else
ddp_input(m, m->m_pkthdr.rcvif, NULL, 1);
}
static void
ddp_input(struct mbuf *m, struct ifnet *ifp, struct elaphdr *elh, int phase)
{
struct sockaddr_at from, to;
struct ddpshdr *dsh, ddps;
struct at_ifaddr *aa;
struct ddpehdr *deh = NULL, ddpe;
struct ddpcb *ddp;
int dlen, mlen;
u_short cksum = 0;
bzero((caddr_t)&from, sizeof(struct sockaddr_at));
bzero((caddr_t)&to, sizeof(struct sockaddr_at));
if (elh != NULL) {
/*
* Extract the information in the short header. Network
* information is defaulted to ATADDR_ANYNET and node
* information comes from the elh info. We must be phase 1.
*/
ddpstat.ddps_short++;
if (m->m_len < sizeof(struct ddpshdr) &&
((m = m_pullup(m, sizeof(struct ddpshdr))) == NULL)) {
ddpstat.ddps_tooshort++;
return;
}
dsh = mtod(m, struct ddpshdr *);
bcopy((caddr_t)dsh, (caddr_t)&ddps, sizeof(struct ddpshdr));
ddps.dsh_bytes = ntohl(ddps.dsh_bytes);
dlen = ddps.dsh_len;
to.sat_addr.s_net = ATADDR_ANYNET;
to.sat_addr.s_node = elh->el_dnode;
to.sat_port = ddps.dsh_dport;
from.sat_addr.s_net = ATADDR_ANYNET;
from.sat_addr.s_node = elh->el_snode;
from.sat_port = ddps.dsh_sport;
/*
* Make sure that we point to the phase1 ifaddr info and that
* it's valid for this packet.
*/
AT_IFADDR_RLOCK();
TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
if ((aa->aa_ifp == ifp)
&& ((aa->aa_flags & AFA_PHASE2) == 0)
&& ((to.sat_addr.s_node ==
AA_SAT(aa)->sat_addr.s_node) ||
(to.sat_addr.s_node == ATADDR_BCAST)))
break;
}
/*
* maybe we got a broadcast not meant for us.. ditch it.
*/
if (aa == NULL) {
AT_IFADDR_RUNLOCK();
m_freem(m);
return;
}
} else {
/*
* There was no 'elh' passed on. This could still be either
* phase1 or phase2. We have a long header, but we may be
* running on a phase 1 net. Extract out all the info
* regarding this packet's src & dst.
*/
ddpstat.ddps_long++;
if (m->m_len < sizeof(struct ddpehdr) &&
((m = m_pullup(m, sizeof(struct ddpehdr))) == NULL)) {
AT_IFADDR_RUNLOCK();
ddpstat.ddps_tooshort++;
return;
}
deh = mtod(m, struct ddpehdr *);
bcopy((caddr_t)deh, (caddr_t)&ddpe, sizeof(struct ddpehdr));
ddpe.deh_bytes = ntohl(ddpe.deh_bytes);
dlen = ddpe.deh_len;
if ((cksum = ddpe.deh_sum) == 0)
ddpstat.ddps_nosum++;
from.sat_addr.s_net = ddpe.deh_snet;
from.sat_addr.s_node = ddpe.deh_snode;
from.sat_port = ddpe.deh_sport;
to.sat_addr.s_net = ddpe.deh_dnet;
to.sat_addr.s_node = ddpe.deh_dnode;
to.sat_port = ddpe.deh_dport;
AT_IFADDR_RLOCK();
if (to.sat_addr.s_net == ATADDR_ANYNET) {
/*
* The TO address doesn't specify a net, so by
* definition it's for this net. Try find ifaddr
* info with the right phase, the right interface,
* and either to our node, a broadcast, or looped
* back (though that SHOULD be covered in the other
* cases).
*
* XXX If we have multiple interfaces, then the first
* with this node number will match (which may NOT be
* what we want, but it's probably safe in 99.999% of
* cases.
*/
TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
if (phase == 1 && (aa->aa_flags &
AFA_PHASE2))
continue;
if (phase == 2 && (aa->aa_flags &
AFA_PHASE2) == 0)
continue;
if ((aa->aa_ifp == ifp) &&
((to.sat_addr.s_node ==
AA_SAT(aa)->sat_addr.s_node) ||
(to.sat_addr.s_node == ATADDR_BCAST) ||
(ifp->if_flags & IFF_LOOPBACK)))
break;
}
} else {
/*
* A destination network was given. We just try to
* find which ifaddr info matches it.
*/
TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
/*
* This is a kludge. Accept packets that are
* for any router on a local netrange.
*/
if (to.sat_addr.s_net == aa->aa_firstnet &&
to.sat_addr.s_node == 0)
break;
/*
* Don't use ifaddr info for which we are
* totally outside the netrange, and it's not
* a startup packet. Startup packets are
* always implicitly allowed on to the next
* test.
*/
if (((ntohs(to.sat_addr.s_net) <
ntohs(aa->aa_firstnet)) ||
(ntohs(to.sat_addr.s_net) >
ntohs(aa->aa_lastnet))) &&
((ntohs(to.sat_addr.s_net) < 0xff00) ||
(ntohs(to.sat_addr.s_net) > 0xfffe)))
continue;
/*
* Don't record a match either if we just
* don't have a match in the node address.
* This can have if the interface is in
* promiscuous mode for example.
*/
if ((to.sat_addr.s_node !=
AA_SAT(aa)->sat_addr.s_node) &&
(to.sat_addr.s_node != ATADDR_BCAST))
continue;
break;
}
}
}
if (aa != NULL)
ifa_ref(&aa->aa_ifa);
AT_IFADDR_RUNLOCK();
/*
* Adjust the length, removing any padding that may have been added
* at a link layer. We do this before we attempt to forward a
* packet, possibly on a different media.
*/
mlen = m->m_pkthdr.len;
if (mlen < dlen) {
ddpstat.ddps_toosmall++;
goto out;
}
if (mlen > dlen)
m_adj(m, dlen - mlen);
/*
* If it isn't for a net on any of our interfaces, or it IS for a net
* on a different interface than it came in on, (and it is not looped
* back) then consider if we should forward it. As we are not really
* a router this is a bit cheeky, but it may be useful some day.
*/
if ((aa == NULL) || ((to.sat_addr.s_node == ATADDR_BCAST) &&
(aa->aa_ifp != ifp) && ((ifp->if_flags & IFF_LOOPBACK) == 0))) {
/*
* If we've explicitly disabled it, don't route anything.
*/
if (ddp_forward == 0)
goto out;
/*
* If the cached forwarding route is still valid, use it.
*
* XXXRW: Access to the cached route may not be properly
* synchronized for parallel input handling.
*/
if (forwro.ro_rt &&
(satosat(&forwro.ro_dst)->sat_addr.s_net !=
to.sat_addr.s_net ||
satosat(&forwro.ro_dst)->sat_addr.s_node !=
to.sat_addr.s_node)) {
RTFREE(forwro.ro_rt);
forwro.ro_rt = NULL;
}
/*
* If we don't have a cached one (any more) or it's useless,
* then get a new route.
*
* XXX this could cause a 'route leak'. Check this!
*/
if (forwro.ro_rt == NULL || forwro.ro_rt->rt_ifp == NULL) {
forwro.ro_dst.sa_len = sizeof(struct sockaddr_at);
forwro.ro_dst.sa_family = AF_APPLETALK;
satosat(&forwro.ro_dst)->sat_addr.s_net =
to.sat_addr.s_net;
satosat(&forwro.ro_dst)->sat_addr.s_node =
to.sat_addr.s_node;
rtalloc(&forwro);
}
/*
* If it's not going to get there on this hop, and it's
* already done too many hops, then throw it away.
*/
if ((to.sat_addr.s_net !=
satosat(&forwro.ro_dst)->sat_addr.s_net) &&
(ddpe.deh_hops == DDP_MAXHOPS))
goto out;
/*
* A ddp router might use the same interface to forward the
* packet, which this would not effect. Don't allow packets
* to cross from one interface to another however.
*/
if (ddp_firewall && ((forwro.ro_rt == NULL) ||
(forwro.ro_rt->rt_ifp != ifp)))
goto out;
/*
* Adjust the header. If it was a short header then it would
* have not gotten here, so we can assume there is room to
* drop the header in.
*
* XXX what about promiscuous mode, etc...
*/
ddpe.deh_hops++;
ddpe.deh_bytes = htonl(ddpe.deh_bytes);
/* XXX deh? */
bcopy((caddr_t)&ddpe, (caddr_t)deh, sizeof(u_short));
if (ddp_route(m, &forwro))
ddpstat.ddps_cantforward++;
else
ddpstat.ddps_forward++;
if (aa != NULL)
ifa_free(&aa->aa_ifa);
return;
}
/*
* It was for us, and we have an ifaddr to use with it.
*/
from.sat_len = sizeof(struct sockaddr_at);
from.sat_family = AF_APPLETALK;
/*
* We are no longer interested in the link layer so cut it off.
*/
if (elh == NULL) {
if (ddp_cksum && cksum && cksum !=
at_cksum(m, sizeof(int))) {
ddpstat.ddps_badsum++;
goto out;
}
m_adj(m, sizeof(struct ddpehdr));
} else
m_adj(m, sizeof(struct ddpshdr));
/*
* Search for ddp protocol control blocks that match these addresses.
*/
DDP_LIST_SLOCK();
if ((ddp = ddp_search(&from, &to, aa)) == NULL)
goto out_unlock;
#ifdef MAC
if (mac_socket_check_deliver(ddp->ddp_socket, m) != 0)
goto out_unlock;
#endif
/*
* If we found one, deliver the packet to the socket
*/
SOCKBUF_LOCK(&ddp->ddp_socket->so_rcv);
if (sbappendaddr_locked(&ddp->ddp_socket->so_rcv,
(struct sockaddr *)&from, m, NULL) == 0) {
SOCKBUF_UNLOCK(&ddp->ddp_socket->so_rcv);
/*
* If the socket is full (or similar error) dump the packet.
*/
ddpstat.ddps_nosockspace++;
goto out_unlock;
}
/*
* And wake up whatever might be waiting for it
*/
sorwakeup_locked(ddp->ddp_socket);
m = NULL;
out_unlock:
DDP_LIST_SUNLOCK();
out:
if (aa != NULL)
ifa_free(&aa->aa_ifa);
if (m != NULL)
m_freem(m);
}
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