ip_input.c revision 2e77ff8c095da5ee3bde45932b06d6eff0abb267
/*
* Copyright (c) 1982, 1986, 1988, 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
* 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.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
* ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
*/
/*
* Changes and additions relating to SLiRP are
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include <slirp.h>
#include "ip_icmp.h"
/*
* IP initialization: fill in IP protocol switch table.
* All protocols not implemented in kernel go to raw IP protocol handler.
*/
void
{
#ifndef VBOX_WITH_BSD_REASS
#else /* !VBOX_WITH_BSD_REASS */
int i = 0;
for (i = 0; i < IPREASS_NHASH; ++i)
TAILQ_INIT(&ipq[i]);
maxfragsperpacket = 16;
nipq = 0;
#endif /* VBOX_WITH_BSD_REASS */
}
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
{
int hlen;
DEBUG_CALL("ip_input");
DEBUG_ARG("m = %lx", (long)m);
return;
}
goto bad;
}
goto bad;
}
/* keep ip header intact for ICMP reply
* ip->ip_sum = cksum(m, hlen);
* if (ip->ip_sum) {
*/
ipstat.ips_badsum++;
goto bad;
}
/*
* Convert fields to host representation.
*/
ipstat.ips_badlen++;
goto bad;
}
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
goto bad;
}
/* Should drop packet if mbuf too long? hmmm... */
/* check ip_ttl for a correct ICMP reply */
goto bad;
}
#ifdef VBOX_WITH_SLIRP_ICMP
#endif
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
/* We do no IP options */
/* if (hlen > sizeof (struct ip) && ip_dooptions(m))
* goto next;
*/
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*
* XXX This should fail, don't fragment yet
*/
#ifndef VBOX_WITH_BSD_REASS
/*
* Look for queue of fragments
* of this datagram.
*/
goto found;
fp = 0;
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
else
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (ip == 0)
return;
} else
if (fp)
} else
#else /* !VBOX_WITH_BSD_REASS */
if (m == NULL)
return;
}
else
#endif /* VBOX_WITH_BSD_REASS */
/*
* Switch out to protocol's input routine.
*/
case IPPROTO_TCP:
break;
case IPPROTO_UDP:
break;
case IPPROTO_ICMP:
break;
default:
}
return;
bad:
return;
}
#ifndef VBOX_WITH_BSD_REASS
/*
* Take incoming datagram fragment and try to
* reassemble it into whole datagram. If a chain for
* reassembly of this datagram already exists, then it
* is given as fp; otherwise have to make a chain.
*/
struct ip *
{
register struct ipasfrag *q;
int i, next;
DEBUG_CALL("ip_reass");
DEBUG_ARG("m = %lx", (long)m);
/*
* Presence of header sizes in mbufs
* would confuse code below.
* Fragment m_data is concatenated.
*/
/*
* If first fragment to arrive, create a reassembly queue.
*/
if (fp == 0) {
struct mbuf *t;
goto insert;
}
/*
* Find a segment which begins after this one does.
*/
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.
*/
if (i > 0) {
goto dropfrag;
}
}
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
if (i < q->ip_len) {
q->ip_len -= i;
q->ip_off += i;
break;
}
}
/*
* Stick new segment in its place;
* check for complete reassembly.
*/
next = 0;
return (0);
}
return (0);
/*
* Reassembly is complete; concatenate fragments.
*/
struct mbuf *t;
}
/*
* Create header for new ip packet by
* modifying header of first packet;
* dequeue and discard fragment reassembly header.
* Make header visible.
*/
/*
* If the fragments concatenated to an mbuf that's
* bigger than the total size of the fragment, then and
* m_ext buffer was alloced. But fp->ipq_next points to
* the old buffer (in the mbuf), so we must point ip
* into the new buffer.
*/
int delta;
}
/* DEBUG_ARG("ip = %lx", (long)ip);
* ip=(struct ipasfrag *)m->m_data; */
return (0);
}
/*
* Free a fragment reassembly header and all
* associated datagrams.
*/
void
{
register struct ipasfrag *q, *p;
q = p) {
}
}
#else /* !VBOX_WITH_BSD_REASS */
struct mbuf *
/* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
if (maxnipq == 0
|| maxfragsperpacket == 0) {
return (NULL);
}
/*
* Look for queue of fragments
* of this datagram.
*/
goto found;
/*
* Attempt to trim the number of allocated fragment queues if it
* exceeds the administrative limit.
*/
/*
* drop something from the tail of the current queue
* before proceeding further
*/
if (q == NULL) { /* gak */
for (i = 0; i < IPREASS_NHASH; i++) {
if (r) {
break;
}
}
} else {
}
}
/*
* Adjust ip_len to not reflect header,
* convert offset of this to bytes.
*/
/*
* Make sure that fragments have a data length
* that's a non-zero multiple of 8 bytes.
*/
goto dropfrag;
}
} else
/*
* Attempt reassembly; if it succeeds, proceed.
* ip_reass() will return a different mbuf.
*/
/* Previous ip_reass() started here. */
/*
* Presence of header sizes in mbufs
* would confuse code below.
*/
/*
* If first fragment to arrive, create a reassembly queue.
*/
goto dropfrag;
nipq++;
goto done;
} else {
fp->ipq_nfrags++;
}
/*
* Find a segment which begins after this one does.
*/
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us, otherwise
* stick new segment in the proper place.
*
* If some of the data is dropped from the the preceding
* segment, then it's checksum is invalidated.
*/
if (p) {
if (i > 0) {
goto dropfrag;
m_adj(m, i);
}
p->m_nextpkt = m;
} else {
}
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
q = nq) {
m_adj(q, i);
break;
}
fp->ipq_nfrags--;
}
/*
* Check for complete reassembly and perform frag per packet
* limiting.
*
* Frag limiting is performed here so that the nth frag has
* a chance to complete the packet before we drop the packet.
* As a result, n+1 frags are actually allowed per packet, but
* only n will ever be stored. (n = maxfragsperpacket.)
*
*/
next = 0;
}
goto done;
}
}
/* Make sure the last packet didn't have the IP_MF flag */
}
goto done;
}
/*
* Reassembly is complete. Make sure the packet is a sane size.
*/
goto done;
}
/*
* Concatenate fragments.
*/
m = q;
#if 0
t = m->m_next;
#endif
}
/*
* Create header for new ip packet by modifying header of first
* packet; dequeue and discard fragment reassembly header.
* Make header visible.
*/
#if 0
#else
#endif
nipq--;
/* some debugging cruft by sklower, below, will go away soon */
#if 0
m_fixhdr(m);
#endif
return (m);
fp->ipq_nfrags--;
done:
return (NULL);
}
void
struct mbuf *q;
}
nipq--;
}
#endif /* VBOX_WITH_BSD_REASS */
#ifndef VBOX_WITH_BSD_REASS
/*
* Put an ip fragment on a reassembly chain.
* Like insque, but pointers in middle of structure.
*/
void
{
DEBUG_CALL("ip_enq");
}
/*
* To ip_enq as remque is to insque.
*/
void
{
}
#endif /* !VBOX_WITH_BSD_REASS */
/*
* IP timer processing;
* if a timer expires on a reassembly
* queue, discard it.
*/
void
{
#ifndef VBOX_WITH_BSD_REASS
DEBUG_CALL("ip_slowtimo");
if (fp == 0)
return;
}
}
#else /* !VBOX_WITH_BSD_REASS */
/* XXX: the fragment expiration is the same but requier
* additional loop see (see ip_input.c in FreeBSD tree)
*/
int i;
DEBUG_CALL("ip_slowtimo");
for (i = 0; i < IPREASS_NHASH; i++) {
}
}
}
/*
* If we are over the maximum number of fragments
* (due to the limit being lowered), drain off
* enough to get down to the new limit.
*/
for (i = 0; i < IPREASS_NHASH; i++) {
}
}
}
#endif /* VBOX_WITH_BSD_REASS */
}
/*
* Do option processing on a datagram,
* possibly discarding it if bad options are encountered,
* or forwarding it if source-routed.
* 0 if the packet should be processed further.
*/
#ifdef notdef
int
ip_dooptions(m)
struct mbuf *m;
{
register struct ip_timestamp *ipt;
/* int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; */
break;
optlen = 1;
else {
goto bad;
}
}
switch (opt) {
default:
break;
/*
* Source routing with record.
* Find interface with current destination address.
* If none on this machine then drop if strictly routed,
* or do nothing if loosely routed.
* Record interface address and bring up next address
* component. If strictly routed make sure next
* address is on directly accessible net.
*/
case IPOPT_LSRR:
case IPOPT_SSRR:
goto bad;
}
if (ia == 0) {
if (opt == IPOPT_SSRR) {
type = ICMP_UNREACH;
goto bad;
}
/*
* Loose routing, and not at next destination
* yet; nothing to do except forward.
*/
break;
}
/*
* End of source route. Should be for us.
*/
break;
}
/*
* locate outgoing interface
*/
if (opt == IPOPT_SSRR) {
} else
if (ia == 0) {
type = ICMP_UNREACH;
goto bad;
}
/*
* Let ip_intr's mcast routing check handle mcast pkts
*/
break;
case IPOPT_RR:
goto bad;
}
/*
* If no space remains, ignore.
*/
break;
/*
* locate outgoing interface; if we're the destination,
* use the incoming interface (should be same).
*/
type = ICMP_UNREACH;
goto bad;
}
break;
case IPOPT_TS:
goto bad;
goto bad;
break;
}
case IPOPT_TS_TSONLY:
break;
case IPOPT_TS_TSANDADDR:
goto bad;
if (ia == 0)
continue;
break;
case IPOPT_TS_PRESPEC:
goto bad;
sizeof(struct in_addr));
continue;
break;
default:
goto bad;
}
sizeof(n_time));
}
}
if (forward) {
ip_forward(m, 1);
return (1);
}
}
}
return (0);
bad:
/* ip->ip_len -= ip->ip_hl << 2; XXX icmp_error adds in hdr length */
/* Not yet */
return (1);
}
#endif /* notdef */
/*
* Strip out IP options, at higher
* level protocol in the kernel.
* Second argument is buffer to which options
* will be moved, and return value is their length.
* (XXX) should be deleted; last arg currently ignored.
*/
void
ip_stripoptions(m, mopt)
register struct mbuf *m;
{
register int i;
int olen;
}