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openvpn/mroute.c
David Sommerseth b7bbe47a7f Only warn about non-tackled IPv6 packets once
When using OpenVPN 2.2 on clients and server with Windows based
clients, it will try to push IPv6 packets through the tunnel.  This
causes the server log to be filled up with log entries like this:

 Wed Jun 29 22:12:51 2011 username/1.2.3.4:56990 Need IPv6 code in mroute_extract_addr_from_packet

This patch modifies this message to state that IPv6 packets are not
tackled in tun mode, and prints it only once.

Trac: 147
Signed-off-by: David Sommerseth <davids@redhat.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
2011-12-13 21:16:25 +01:00

435 lines
10 KiB
C

/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "syshead.h"
#if P2MP_SERVER
#include "mroute.h"
#include "proto.h"
#include "error.h"
#include "socket.h"
#include "memdbg.h"
void
mroute_addr_init (struct mroute_addr *addr)
{
CLEAR (*addr);
}
/*
* Ethernet multicast addresses.
*/
static inline bool
is_mac_mcast_addr (const uint8_t *mac)
{
return (bool) mac[0] & 1;
}
static inline bool
is_mac_mcast_maddr (const struct mroute_addr *addr)
{
return (addr->type & MR_ADDR_MASK) == MR_ADDR_ETHER && is_mac_mcast_addr (addr->addr);
}
/*
* Don't learn certain addresses.
*/
bool
mroute_learnable_address (const struct mroute_addr *addr)
{
int i;
bool not_all_zeros = false;
bool not_all_ones = false;
for (i = 0; i < addr->len; ++i)
{
int b = addr->addr[i];
if (b != 0x00)
not_all_zeros = true;
if (b != 0xFF)
not_all_ones = true;
}
return not_all_zeros && not_all_ones && !is_mac_mcast_maddr (addr);
}
static inline void
mroute_get_in_addr_t (struct mroute_addr *ma, const in_addr_t src, unsigned int mask)
{
if (ma)
{
ma->type = MR_ADDR_IPV4 | mask;
ma->netbits = 0;
ma->len = 4;
*(in_addr_t*)ma->addr = src;
}
}
static inline bool
mroute_is_mcast (const in_addr_t addr)
{
return ((addr & htonl(IP_MCAST_SUBNET_MASK)) == htonl(IP_MCAST_NETWORK));
}
#ifdef ENABLE_PF
static unsigned int
mroute_extract_addr_arp (struct mroute_addr *src,
struct mroute_addr *dest,
const struct buffer *buf)
{
unsigned int ret = 0;
if (BLEN (buf) >= (int) sizeof (struct openvpn_arp))
{
const struct openvpn_arp *arp = (const struct openvpn_arp *) BPTR (buf);
if (arp->mac_addr_type == htons(0x0001)
&& arp->proto_addr_type == htons(0x0800)
&& arp->mac_addr_size == 0x06
&& arp->proto_addr_size == 0x04)
{
mroute_get_in_addr_t (src, arp->ip_src, MR_ARP);
mroute_get_in_addr_t (dest, arp->ip_dest, MR_ARP);
/* multicast packet? */
if (mroute_is_mcast (arp->ip_dest))
ret |= MROUTE_EXTRACT_MCAST;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
}
return ret;
}
#endif
unsigned int
mroute_extract_addr_ipv4 (struct mroute_addr *src,
struct mroute_addr *dest,
const struct buffer *buf)
{
unsigned int ret = 0;
static bool ipv6warned = false;
if (BLEN (buf) >= 1)
{
switch (OPENVPN_IPH_GET_VER (*BPTR(buf)))
{
case 4:
if (BLEN (buf) >= (int) sizeof (struct openvpn_iphdr))
{
const struct openvpn_iphdr *ip = (const struct openvpn_iphdr *) BPTR (buf);
mroute_get_in_addr_t (src, ip->saddr, 0);
mroute_get_in_addr_t (dest, ip->daddr, 0);
/* multicast packet? */
if (mroute_is_mcast (ip->daddr))
ret |= MROUTE_EXTRACT_MCAST;
/* IGMP message? */
if (ip->protocol == OPENVPN_IPPROTO_IGMP)
ret |= MROUTE_EXTRACT_IGMP;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
break;
case 6:
{
if( !ipv6warned ) {
msg (M_WARN, "IPv6 in tun mode is not supported in OpenVPN 2.2");
ipv6warned = true;
}
break;
}
}
}
return ret;
}
unsigned int
mroute_extract_addr_ether (struct mroute_addr *src,
struct mroute_addr *dest,
struct mroute_addr *esrc,
struct mroute_addr *edest,
const struct buffer *buf)
{
unsigned int ret = 0;
if (BLEN (buf) >= (int) sizeof (struct openvpn_ethhdr))
{
const struct openvpn_ethhdr *eth = (const struct openvpn_ethhdr *) BPTR (buf);
if (src)
{
src->type = MR_ADDR_ETHER;
src->netbits = 0;
src->len = 6;
memcpy (src->addr, eth->source, 6);
}
if (dest)
{
dest->type = MR_ADDR_ETHER;
dest->netbits = 0;
dest->len = 6;
memcpy (dest->addr, eth->dest, 6);
/* ethernet broadcast/multicast packet? */
if (is_mac_mcast_addr (eth->dest))
ret |= MROUTE_EXTRACT_BCAST;
}
ret |= MROUTE_EXTRACT_SUCCEEDED;
#ifdef ENABLE_PF
if (esrc || edest)
{
struct buffer b = *buf;
if (buf_advance (&b, sizeof (struct openvpn_ethhdr)))
{
switch (ntohs (eth->proto))
{
case OPENVPN_ETH_P_IPV4:
ret |= (mroute_extract_addr_ipv4 (esrc, edest, &b) << MROUTE_SEC_SHIFT);
break;
case OPENVPN_ETH_P_ARP:
ret |= (mroute_extract_addr_arp (esrc, edest, &b) << MROUTE_SEC_SHIFT);
break;
}
}
}
#endif
}
return ret;
}
/*
* Translate a struct openvpn_sockaddr (osaddr)
* to a struct mroute_addr (addr).
*/
bool mroute_extract_openvpn_sockaddr (struct mroute_addr *addr,
const struct openvpn_sockaddr *osaddr,
bool use_port)
{
if (osaddr->sa.sin_family == AF_INET)
{
if (use_port)
{
addr->type = MR_ADDR_IPV4 | MR_WITH_PORT;
addr->netbits = 0;
addr->len = 6;
memcpy (addr->addr, &osaddr->sa.sin_addr.s_addr, 4);
memcpy (addr->addr + 4, &osaddr->sa.sin_port, 2);
}
else
{
addr->type = MR_ADDR_IPV4;
addr->netbits = 0;
addr->len = 4;
memcpy (addr->addr, &osaddr->sa.sin_addr.s_addr, 4);
}
return true;
}
return false;
}
/*
* Zero off the host bits in an address, leaving
* only the network bits, using the netbits member of
* struct mroute_addr as the controlling parameter.
*/
void
mroute_addr_mask_host_bits (struct mroute_addr *ma)
{
in_addr_t addr = ntohl(*(in_addr_t*)ma->addr);
ASSERT ((ma->type & MR_ADDR_MASK) == MR_ADDR_IPV4);
addr &= netbits_to_netmask (ma->netbits);
*(in_addr_t*)ma->addr = htonl (addr);
}
/*
* The mroute_addr hash function takes into account the
* address type, number of bits in the network address,
* and the actual address.
*/
uint32_t
mroute_addr_hash_function (const void *key, uint32_t iv)
{
return hash_func (mroute_addr_hash_ptr ((const struct mroute_addr *) key),
mroute_addr_hash_len ((const struct mroute_addr *) key),
iv);
}
bool
mroute_addr_compare_function (const void *key1, const void *key2)
{
return mroute_addr_equal ((const struct mroute_addr *) key1,
(const struct mroute_addr *) key2);
}
const char *
mroute_addr_print (const struct mroute_addr *ma,
struct gc_arena *gc)
{
return mroute_addr_print_ex (ma, MAPF_IA_EMPTY_IF_UNDEF, gc);
}
const char *
mroute_addr_print_ex (const struct mroute_addr *ma,
const unsigned int flags,
struct gc_arena *gc)
{
struct buffer out = alloc_buf_gc (64, gc);
if (ma)
{
struct mroute_addr maddr = *ma;
switch (maddr.type & MR_ADDR_MASK)
{
case MR_ADDR_ETHER:
buf_printf (&out, "%s", format_hex_ex (ma->addr, 6, 0, 1, ":", gc));
break;
case MR_ADDR_IPV4:
{
struct buffer buf;
in_addr_t addr;
int port;
bool status;
buf_set_read (&buf, maddr.addr, maddr.len);
addr = buf_read_u32 (&buf, &status);
if (status)
{
if ((flags & MAPF_SHOW_ARP) && (maddr.type & MR_ARP))
buf_printf (&out, "ARP/");
buf_printf (&out, "%s", print_in_addr_t (addr, (flags & MAPF_IA_EMPTY_IF_UNDEF) ? IA_EMPTY_IF_UNDEF : 0, gc));
if (maddr.type & MR_WITH_NETBITS)
{
if (flags & MAPF_SUBNET)
{
const in_addr_t netmask = netbits_to_netmask (maddr.netbits);
buf_printf (&out, "/%s", print_in_addr_t (netmask, 0, gc));
}
else
buf_printf (&out, "/%d", maddr.netbits);
}
}
if (maddr.type & MR_WITH_PORT)
{
port = buf_read_u16 (&buf);
if (port >= 0)
buf_printf (&out, ":%d", port);
}
}
break;
case MR_ADDR_IPV6:
buf_printf (&out, "IPV6");
break;
default:
buf_printf (&out, "UNKNOWN");
break;
}
return BSTR (&out);
}
else
return "[NULL]";
}
/*
* mroute_helper's main job is keeping track of
* currently used CIDR netlengths, so we don't
* have to cycle through all 33.
*/
struct mroute_helper *
mroute_helper_init (int ageable_ttl_secs)
{
struct mroute_helper *mh;
ALLOC_OBJ_CLEAR (mh, struct mroute_helper);
mh->ageable_ttl_secs = ageable_ttl_secs;
return mh;
}
static void
mroute_helper_regenerate (struct mroute_helper *mh)
{
int i, j = 0;
for (i = MR_HELPER_NET_LEN - 1; i >= 0; --i)
{
if (mh->net_len_refcount[i] > 0)
mh->net_len[j++] = (uint8_t) i;
}
mh->n_net_len = j;
#ifdef ENABLE_DEBUG
if (check_debug_level (D_MULTI_DEBUG))
{
struct gc_arena gc = gc_new ();
struct buffer out = alloc_buf_gc (256, &gc);
buf_printf (&out, "MROUTE CIDR netlen:");
for (i = 0; i < mh->n_net_len; ++i)
{
buf_printf (&out, " /%d", mh->net_len[i]);
}
dmsg (D_MULTI_DEBUG, "%s", BSTR (&out));
gc_free (&gc);
}
#endif
}
void
mroute_helper_add_iroute (struct mroute_helper *mh, const struct iroute *ir)
{
if (ir->netbits >= 0)
{
ASSERT (ir->netbits < MR_HELPER_NET_LEN);
++mh->cache_generation;
++mh->net_len_refcount[ir->netbits];
if (mh->net_len_refcount[ir->netbits] == 1)
mroute_helper_regenerate (mh);
}
}
void
mroute_helper_del_iroute (struct mroute_helper *mh, const struct iroute *ir)
{
if (ir->netbits >= 0)
{
ASSERT (ir->netbits < MR_HELPER_NET_LEN);
++mh->cache_generation;
--mh->net_len_refcount[ir->netbits];
ASSERT (mh->net_len_refcount[ir->netbits] >= 0);
if (!mh->net_len_refcount[ir->netbits])
mroute_helper_regenerate (mh);
}
}
void
mroute_helper_free (struct mroute_helper *mh)
{
free (mh);
}
#else
static void dummy(void) {}
#endif /* P2MP_SERVER */