ip_output.c revision fe0336dab2332556574fab2b79ab4210a7989127
2362N/A/* $Id$ */
639N/A/** @file
639N/A * NAT - IP output.
639N/A */
639N/A
2362N/A/*
639N/A * Copyright (C) 2006-2010 Oracle Corporation
2362N/A *
639N/A * This file is part of VirtualBox Open Source Edition (OSE), as
639N/A * available from http://www.virtualbox.org. This file is free software;
639N/A * you can redistribute it and/or modify it under the terms of the GNU
639N/A * General Public License (GPL) as published by the Free Software
639N/A * Foundation, in version 2 as it comes in the "COPYING" file of the
639N/A * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
639N/A * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
639N/A */
639N/A
639N/A/*
639N/A * This code is based on:
2362N/A *
2362N/A * Copyright (c) 1982, 1986, 1988, 1990, 1993
2362N/A * The Regents of the University of California. All rights reserved.
639N/A *
639N/A * Redistribution and use in source and binary forms, with or without
639N/A * modification, are permitted provided that the following conditions
639N/A * are met:
639N/A * 1. Redistributions of source code must retain the above copyright
639N/A * notice, this list of conditions and the following disclaimer.
639N/A * 2. Redistributions in binary form must reproduce the above copyright
639N/A * notice, this list of conditions and the following disclaimer in the
639N/A * documentation and/or other materials provided with the distribution.
639N/A * 3. All advertising materials mentioning features or use of this software
639N/A * must display the following acknowledgement:
639N/A * This product includes software developed by the University of
639N/A * California, Berkeley and its contributors.
639N/A * 4. Neither the name of the University nor the names of its contributors
639N/A * may be used to endorse or promote products derived from this software
639N/A * without specific prior written permission.
639N/A *
639N/A * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
639N/A * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
639N/A * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
639N/A * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
639N/A * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
639N/A * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
639N/A * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
639N/A * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
639N/A * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
639N/A * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
639N/A * SUCH DAMAGE.
639N/A *
639N/A * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
639N/A * ip_output.c,v 1.9 1994/11/16 10:17:10 jkh Exp
639N/A */
639N/A
639N/A/*
639N/A * Changes and additions relating to SLiRP are
639N/A * Copyright (c) 1995 Danny Gasparovski.
639N/A *
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include <slirp.h>
#include "alias.h"
static const uint8_t broadcast_ethaddr[6] =
{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};
static int rt_lookup_in_cache(PNATState pData, uint32_t dst, uint8_t *ether)
{
int rc;
if (dst == INADDR_BROADCAST)
{
memcpy(ether, broadcast_ethaddr, ETH_ALEN);
return VINF_SUCCESS;
}
rc = slirp_arp_lookup_ether_by_ip(pData, dst, ether);
if (RT_SUCCESS(rc))
return rc;
rc = bootp_cache_lookup_ether_by_ip(pData, dst, ether);
if (RT_SUCCESS(rc))
return rc;
/*
* no chance to send this packet, sorry, we will request ether address via ARP
*/
slirp_arp_who_has(pData, dst);
return VERR_NOT_FOUND;
}
/*
* IP output. The packet in mbuf chain m contains a skeletal IP
* header (with len, off, ttl, proto, tos, src, dst).
* The mbuf chain containing the packet will be freed.
* The mbuf opt, if present, will not be freed.
*/
int
ip_output(PNATState pData, struct socket *so, struct mbuf *m0)
{
return ip_output0(pData, so, m0, 0);
}
int
ip_output0(PNATState pData, struct socket *so, struct mbuf *m0, int urg)
{
register struct ip *ip;
register struct mbuf *m = m0;
register int hlen = sizeof(struct ip );
int len, off, error = 0;
extern uint8_t zerro_ethaddr[ETH_ALEN];
struct ethhdr *eh = NULL;
uint8_t eth_dst[ETH_ALEN];
int rc = 1;
STAM_PROFILE_START(&pData->StatIP_output, a);
DEBUG_CALL("ip_output");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("m0 = %lx", (long)m0);
M_ASSERTPKTHDR(m);
Assert(m->m_pkthdr.header);
#if 0 /* We do no options */
if (opt)
{
m = ip_insertoptions(m, opt, &len);
hlen = len;
}
#endif
ip = mtod(m, struct ip *);
/*
* Fill in IP header.
*/
ip->ip_v = IPVERSION;
ip->ip_off &= IP_DF;
ip->ip_id = RT_H2N_U16(ip_currid++);
ip->ip_hl = hlen >> 2;
ipstat.ips_localout++;
/* Current TCP/IP stack hasn't routing information at
* all so we need to calculate destination ethernet address
*/
rc = rt_lookup_in_cache(pData, ip->ip_dst.s_addr, eth_dst);
if (RT_FAILURE(rc))
goto exit_drop_package;
eh = (struct ethhdr *)(m->m_data - ETH_HLEN);
/*
* If small enough for interface, can just send directly.
*/
if ((u_int16_t)ip->ip_len <= if_mtu)
{
ip->ip_len = RT_H2N_U16((u_int16_t)ip->ip_len);
ip->ip_off = RT_H2N_U16((u_int16_t)ip->ip_off);
ip->ip_sum = 0;
ip->ip_sum = cksum(m, hlen);
{
struct m_tag *t;
STAM_PROFILE_START(&pData->StatALIAS_output, b);
if ((t = m_tag_find(m, PACKET_TAG_ALIAS, NULL)) != 0)
rc = LibAliasOut((struct libalias *)&t[1], mtod(m, char *),
m_length(m, NULL));
else
rc = LibAliasOut(pData->proxy_alias, mtod(m, char *),
m_length(m, NULL));
if (rc == PKT_ALIAS_IGNORED)
{
Log(("NAT: packet was droppped\n"));
goto exit_drop_package;
}
STAM_PROFILE_STOP(&pData->StatALIAS_output, b);
}
memcpy(eh->h_source, eth_dst, ETH_ALEN);
if_encap(pData, ETH_P_IP, m, urg? ETH_ENCAP_URG : 0);
goto done;
}
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
if (ip->ip_off & IP_DF)
{
error = -1;
ipstat.ips_cantfrag++;
goto exit_drop_package;
}
len = (if_mtu - hlen) &~ 7; /* ip databytes per packet */
if (len < 8)
{
error = -1;
goto exit_drop_package;
}
{
int mhlen, firstlen = len;
struct mbuf **mnext = &m->m_nextpkt;
char *buf; /* intermediate buffer we'll use for copy from orriginal packet */
{
struct m_tag *t;
char *tmpbuf = NULL;
int tmplen = 0;
int rcLa;
HTONS(ip->ip_len);
HTONS(ip->ip_off);
ip->ip_sum = 0;
ip->ip_sum = cksum(m, hlen);
if (m->m_next != NULL)
{
/*we've receives packet in fragments*/
tmplen = m_length(m, NULL);
tmpbuf = RTMemAlloc(tmplen);
Assert(tmpbuf);
m_copydata(m, 0, tmplen, tmpbuf);
}
else
{
tmpbuf = mtod(m, char *);
tmplen = m_length(m, NULL);
}
if ((t = m_tag_find(m, PACKET_TAG_ALIAS, NULL)) != 0)
rcLa = LibAliasOut((struct libalias *)&t[1], tmpbuf, tmplen);
else
rcLa = LibAliasOut(pData->proxy_alias, tmpbuf, tmplen);
if (m->m_next != NULL)
{
if (rcLa != PKT_ALIAS_IGNORED)
{
struct ip *tmpip = (struct ip *)tmpbuf;
m_copyback(pData, m, 0, RT_N2H_U16(tmpip->ip_len) + (tmpip->ip_hl << 2), tmpbuf);
}
if (tmpbuf != NULL)
RTMemFree(tmpbuf);
}
if (rcLa == PKT_ALIAS_IGNORED)
{
Log(("NAT: packet was droppped\n"));
goto exit_drop_package;
}
NTOHS(ip->ip_len);
NTOHS(ip->ip_off);
Log2(("NAT: LibAlias return %d\n", rcLa));
}
/*
* Loop through length of segment after first fragment,
* make new header and copy data of each part and link onto chain.
*/
m0 = m;
mhlen = sizeof (struct ip);
for (off = hlen + len; off < (u_int16_t)ip->ip_len; off += len)
{
register struct ip *mhip;
m = m_getcl(pData, M_NOWAIT, MT_HEADER, M_PKTHDR);
if (m == 0)
{
error = -1;
ipstat.ips_odropped++;
goto sendorfree;
}
m->m_data += if_maxlinkhdr;
mhip = mtod(m, struct ip *);
*mhip = *ip;
m->m_len += ip->ip_hl << 2;
m->m_pkthdr.header = mtod(m, void *);
/* we've calculated eth_dst for first packet */
#if 0 /* No options */
if (hlen > sizeof (struct ip))
{
mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
mhip->ip_hl = mhlen >> 2;
}
#endif
mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF);
if (ip->ip_off & IP_MF)
mhip->ip_off |= IP_MF;
if (off + len >= (u_int16_t)ip->ip_len)
len = (u_int16_t)ip->ip_len - off;
else
mhip->ip_off |= IP_MF;
mhip->ip_len = RT_H2N_U16((u_int16_t)(len + mhlen));
buf = RTMemAlloc(len);
m_copydata(m0, off, len, buf); /* copy to buffer */
m->m_data += mhlen;
m_copyback(pData, m, 0, len, buf); /* copy from buffer */
m->m_data -= mhlen;
m->m_len += mhlen;
RTMemFree(buf);
m->m_len += RT_N2H_U16(mhip->ip_len);
mhip->ip_off = RT_H2N_U16((u_int16_t)mhip->ip_off);
mhip->ip_sum = 0;
mhip->ip_sum = cksum(m, mhlen);
*mnext = m;
mnext = &m->m_nextpkt;
ipstat.ips_ofragments++;
}
/*
* Update first fragment by trimming what's been copied out
* and updating header, then send each fragment (in order).
*/
m = m0;
m_adj(m, hlen + firstlen - (u_int16_t)ip->ip_len);
ip->ip_len = RT_H2N_U16((u_int16_t)m->m_len);
ip->ip_off = RT_H2N_U16((u_int16_t)(ip->ip_off | IP_MF));
ip->ip_sum = 0;
ip->ip_sum = cksum(m, hlen);
sendorfree:
for (m = m0; m; m = m0)
{
m0 = m->m_nextpkt;
m->m_nextpkt = 0;
if (error == 0)
{
m->m_data -= ETH_HLEN;
eh = mtod(m, struct ethhdr *);
m->m_data += ETH_HLEN;
memcpy(eh->h_source, eth_dst, ETH_ALEN);
if_encap(pData, ETH_P_IP, m, 0);
}
else
{
m_freem(pData, m);
}
}
if (error == 0)
ipstat.ips_fragmented++;
}
done:
STAM_PROFILE_STOP(&pData->StatIP_output, a);
return error;
exit_drop_package:
m_freem(pData, m0);
STAM_PROFILE_STOP(&pData->StatIP_output, a);
return error;
}