/*
* Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* 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; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/in.h>
#include <ipxe/iobuf.h>
#include <ipxe/tcpip.h>
#include <ipxe/ipv6.h>
#include <ipxe/icmpv6.h>
#include <ipxe/neighbour.h>
#include <ipxe/ndp.h>
/** @file
*
* IPv6 neighbour discovery protocol
*
*/
/**
* Transmit NDP neighbour solicitation/advertisement packet
*
* @v netdev Network device
* @v sin6_src Source socket address
* @v sin6_dest Destination socket address
* @v target Neighbour target address
* @v icmp_type ICMPv6 type
* @v flags NDP flags
* @v option_type NDP option type
* @ret rc Return status code
*/
static int ndp_tx_neighbour ( struct net_device *netdev,
struct sockaddr_in6 *sin6_src,
struct sockaddr_in6 *sin6_dest,
const struct in6_addr *target,
unsigned int icmp_type,
unsigned int flags,
unsigned int option_type ) {
struct sockaddr_tcpip *st_src =
( ( struct sockaddr_tcpip * ) sin6_src );
struct sockaddr_tcpip *st_dest =
( ( struct sockaddr_tcpip * ) sin6_dest );
struct ll_protocol *ll_protocol = netdev->ll_protocol;
struct io_buffer *iobuf;
struct ndp_header *ndp;
size_t option_len;
size_t len;
int rc;
/* Allocate and populate buffer */
option_len = ( ( sizeof ( ndp->option[0] ) + ll_protocol->ll_addr_len +
NDP_OPTION_BLKSZ - 1 ) &
~( NDP_OPTION_BLKSZ - 1 ) );
len = ( sizeof ( *ndp ) + option_len );
iobuf = alloc_iob ( MAX_LL_NET_HEADER_LEN + len );
if ( ! iobuf )
return -ENOMEM;
iob_reserve ( iobuf, MAX_LL_NET_HEADER_LEN );
ndp = iob_put ( iobuf, len );
memset ( ndp, 0, len );
ndp->icmp.type = icmp_type;
ndp->flags = flags;
memcpy ( &ndp->target, target, sizeof ( ndp->target ) );
ndp->option[0].type = option_type;
ndp->option[0].blocks = ( option_len / NDP_OPTION_BLKSZ );
memcpy ( ndp->option[0].value, netdev->ll_addr,
ll_protocol->ll_addr_len );
ndp->icmp.chksum = tcpip_chksum ( ndp, len );
/* Transmit packet */
if ( ( rc = tcpip_tx ( iobuf, &icmpv6_protocol, st_src, st_dest,
netdev, &ndp->icmp.chksum ) ) != 0 ) {
DBGC ( netdev, "NDP could not transmit packet: %s\n",
strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Transmit NDP neighbour discovery request
*
* @v netdev Network device
* @v net_protocol Network-layer protocol
* @v net_dest Destination network-layer address
* @v net_source Source network-layer address
* @ret rc Return status code
*/
static int ndp_tx_request ( struct net_device *netdev,
struct net_protocol *net_protocol __unused,
const void *net_dest, const void *net_source ) {
struct sockaddr_in6 sin6_src;
struct sockaddr_in6 sin6_dest;
/* Construct source address */
memset ( &sin6_src, 0, sizeof ( sin6_src ) );
sin6_src.sin6_family = AF_INET6;
memcpy ( &sin6_src.sin6_addr, net_source,
sizeof ( sin6_src.sin6_addr ) );
sin6_src.sin6_scope_id = htons ( netdev->index );
/* Construct multicast destination address */
memset ( &sin6_dest, 0, sizeof ( sin6_dest ) );
sin6_dest.sin6_family = AF_INET6;
sin6_dest.sin6_scope_id = htons ( netdev->index );
ipv6_solicited_node ( &sin6_dest.sin6_addr, net_dest );
/* Transmit neighbour discovery packet */
return ndp_tx_neighbour ( netdev, &sin6_src, &sin6_dest, net_dest,
ICMPV6_NDP_NEIGHBOUR_SOLICITATION, 0,
NDP_OPT_LL_SOURCE );
}
/** NDP neighbour discovery protocol */
struct neighbour_discovery ndp_discovery = {
.name = "NDP",
.tx_request = ndp_tx_request,
};
/**
* Process NDP neighbour solicitation source link-layer address option
*
* @v netdev Network device
* @v sin6_src Source socket address
* @v ndp NDP packet
* @v ll_addr Source link-layer address
* @v ll_addr_len Source link-layer address length
* @ret rc Return status code
*/
static int ndp_rx_neighbour_solicitation ( struct net_device *netdev,
struct sockaddr_in6 *sin6_src,
struct ndp_header *ndp __unused,
const void *ll_addr,
size_t ll_addr_len ) {
struct ll_protocol *ll_protocol = netdev->ll_protocol;
int rc;
/* Silently ignore neighbour solicitations for addresses we do
* not own.
*/
if ( ! ipv6_has_addr ( netdev, &ndp->target ) )
return 0;
/* Sanity check */
if ( ll_addr_len < ll_protocol->ll_addr_len ) {
DBGC ( netdev, "NDP neighbour solicitation link-layer address "
"too short at %zd bytes (min %d bytes)\n",
ll_addr_len, ll_protocol->ll_addr_len );
return -EINVAL;
}
/* Create or update neighbour cache entry */
if ( ( rc = neighbour_define ( netdev, &ipv6_protocol,
&sin6_src->sin6_addr,
ll_addr ) ) != 0 ) {
DBGC ( netdev, "NDP could not define %s => %s: %s\n",
inet6_ntoa ( &sin6_src->sin6_addr ),
ll_protocol->ntoa ( ll_addr ), strerror ( rc ) );
return rc;
}
/* Send neighbour advertisement */
if ( ( rc = ndp_tx_neighbour ( netdev, NULL, sin6_src, &ndp->target,
ICMPV6_NDP_NEIGHBOUR_ADVERTISEMENT,
( NDP_SOLICITED | NDP_OVERRIDE ),
NDP_OPT_LL_TARGET ) ) != 0 ) {
return rc;
}
return 0;
}
/**
* Process NDP neighbour advertisement target link-layer address option
*
* @v netdev Network device
* @v sin6_src Source socket address
* @v ndp NDP packet
* @v ll_addr Target link-layer address
* @v ll_addr_len Target link-layer address length
* @ret rc Return status code
*/
static int
ndp_rx_neighbour_advertisement ( struct net_device *netdev,
struct sockaddr_in6 *sin6_src __unused,
struct ndp_header *ndp, const void *ll_addr,
size_t ll_addr_len ) {
struct ll_protocol *ll_protocol = netdev->ll_protocol;
int rc;
/* Sanity check */
if ( ll_addr_len < ll_protocol->ll_addr_len ) {
DBGC ( netdev, "NDP neighbour advertisement link-layer address "
"too short at %zd bytes (min %d bytes)\n",
ll_addr_len, ll_protocol->ll_addr_len );
return -EINVAL;
}
/* Update neighbour cache entry, if any */
if ( ( rc = neighbour_update ( netdev, &ipv6_protocol, &ndp->target,
ll_addr ) ) != 0 ) {
DBGC ( netdev, "NDP could not update %s => %s: %s\n",
inet6_ntoa ( &ndp->target ),
ll_protocol->ntoa ( ll_addr ), strerror ( rc ) );
return rc;
}
return 0;
}
/** An NDP option handler */
struct ndp_option_handler {
/** ICMPv6 type */
uint8_t icmp_type;
/** Option type */
uint8_t option_type;
/**
* Handle received option
*
* @v netdev Network device
* @v sin6_src Source socket address
* @v ndp NDP packet
* @v value Option value
* @v len Option length
* @ret rc Return status code
*/
int ( * rx ) ( struct net_device *netdev, struct sockaddr_in6 *sin6_src,
struct ndp_header *ndp, const void *value, size_t len );
};
/** NDP option handlers */
static struct ndp_option_handler ndp_option_handlers[] = {
{
.icmp_type = ICMPV6_NDP_NEIGHBOUR_SOLICITATION,
.option_type = NDP_OPT_LL_SOURCE,
.rx = ndp_rx_neighbour_solicitation,
},
{
.icmp_type = ICMPV6_NDP_NEIGHBOUR_ADVERTISEMENT,
.option_type = NDP_OPT_LL_TARGET,
.rx = ndp_rx_neighbour_advertisement,
},
};
/**
* Process received NDP option
*
* @v netdev Network device
* @v sin6_src Source socket address
* @v ndp NDP packet
* @v type Option type
* @v value Option value
* @v len Option length
* @ret rc Return status code
*/
static int ndp_rx_option ( struct net_device *netdev,
struct sockaddr_in6 *sin6_src,
struct ndp_header *ndp, unsigned int type,
const void *value, size_t len ) {
struct ndp_option_handler *handler;
unsigned int i;
/* Locate a suitable option handler, if any */
for ( i = 0 ; i < ( sizeof ( ndp_option_handlers ) /
sizeof ( ndp_option_handlers[0] ) ) ; i++ ) {
handler = &ndp_option_handlers[i];
if ( ( handler->icmp_type == ndp->icmp.type ) &&
( handler->option_type == type ) ) {
return handler->rx ( netdev, sin6_src, ndp,
value, len );
}
}
/* Silently ignore unknown options as per RFC 4861 */
return 0;
}
/**
* Process received NDP packet
*
* @v iobuf I/O buffer
* @v netdev Network device
* @v sin6_src Source socket address
* @v sin6_dest Destination socket address
* @ret rc Return status code
*/
static int ndp_rx ( struct io_buffer *iobuf,
struct net_device *netdev,
struct sockaddr_in6 *sin6_src,
struct sockaddr_in6 *sin6_dest __unused ) {
struct ndp_header *ndp = iobuf->data;
struct ndp_option *option;
size_t remaining;
size_t option_len;
size_t option_value_len;
int rc;
/* Sanity check */
if ( iob_len ( iobuf ) < sizeof ( *ndp ) ) {
DBGC ( netdev, "NDP packet too short at %zd bytes (min %zd "
"bytes)\n", iob_len ( iobuf ), sizeof ( *ndp ) );
rc = -EINVAL;
goto done;
}
/* Search for option */
option = ndp->option;
remaining = ( iob_len ( iobuf ) - offsetof ( typeof ( *ndp ), option ));
while ( remaining ) {
/* Sanity check */
if ( ( remaining < sizeof ( *option ) ) ||
( option->blocks == 0 ) ||
( remaining < ( option->blocks * NDP_OPTION_BLKSZ ) ) ) {
DBGC ( netdev, "NDP bad option length:\n" );
DBGC_HDA ( netdev, 0, option, remaining );
rc = -EINVAL;
goto done;
}
option_len = ( option->blocks * NDP_OPTION_BLKSZ );
option_value_len = ( option_len - sizeof ( *option ) );
/* Handle option */
if ( ( rc = ndp_rx_option ( netdev, sin6_src, ndp,
option->type, option->value,
option_value_len ) ) != 0 ) {
goto done;
}
/* Move to next option */
option = ( ( ( void * ) option ) + option_len );
remaining -= option_len;
}
/* Success */
rc = 0;
done:
free_iob ( iobuf );
return rc;
}
/** NDP ICMPv6 handlers */
struct icmpv6_handler ndp_handlers[] __icmpv6_handler = {
{
.type = ICMPV6_NDP_NEIGHBOUR_SOLICITATION,
.rx = ndp_rx,
},
{
.type = ICMPV6_NDP_NEIGHBOUR_ADVERTISEMENT,
.rx = ndp_rx,
},
};
