source: mainline/uspace/srv/net/inetsrv/ndp.c@ b8b1adb1

/*
 * Copyright (c) 2013 Antonin Steinhauser
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */

/** @addtogroup ethip
 * @{
 */
/**
 * @file
 * @brief
 */

#include <errno.h>
#include <mem.h>
#include <malloc.h>
#include <io/log.h>
#include <net/socket_codes.h>
#include "ntrans.h"
#include "addrobj.h"
#include "pdu.h"
#include "inet_link.h"
#include "ndp.h"

/** Time to wait for NDP reply in microseconds */
#define NDP_REQUEST_TIMEOUT  (3 * 1000 * 1000)

static addr128_t solicited_node_ip =
    {0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01, 0xff, 0, 0, 0};

/** Compute solicited node IPv6 multicast address from target IPv6 address
 *
 * @param ip_addr      Target IPv6 address
 * @param ip_solicited Solicited IPv6 address to be assigned
 *
 */
static void ndp_solicited_node_ip(addr128_t ip_addr,
    addr128_t ip_solicited)
{
        memcpy(ip_solicited, solicited_node_ip, 13);
        memcpy(ip_solicited + 13, ip_addr + 13, 3);
}

static int ndp_send_packet(inet_link_t *link, ndp_packet_t *packet)
{
        inet_dgram_t dgram;
        ndp_pdu_encode(packet, &dgram);
        
        inet_link_send_dgram6(link, packet->target_hw_addr, &dgram,
            IP_PROTO_ICMPV6, INET6_HOP_LIMIT_MAX, 0);
        
        free(dgram.data);
        
        return EOK;
}

static int ndp_router_advertisement(inet_dgram_t *dgram, inet_addr_t *router)
{
        // FIXME TODO
        return ENOTSUP;
}

int ndp_received(inet_dgram_t *dgram)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "ndp_received()");
        
        ndp_packet_t packet;
        int rc = ndp_pdu_decode(dgram, &packet);
        if (rc != EOK)
                return rc;
        
        inet_addr_t sender;
        inet_addr_set6(packet.sender_proto_addr, &sender);
        
        inet_addr_t target;
        inet_addr_set6(packet.target_proto_addr, &target);
        
        inet_addrobj_t *laddr;
        
        log_msg(LOG_DEFAULT, LVL_DEBUG, "NDP PDU decoded; opcode: %d",
            packet.opcode);
        
        switch (packet.opcode) {
        case ICMPV6_NEIGHBOUR_SOLICITATION:
                laddr = inet_addrobj_find(&target, iaf_addr);
                if (laddr != NULL) {
                        rc = ntrans_add(packet.sender_proto_addr,
                            packet.sender_hw_addr);
                        if (rc != EOK)
                                return rc;
                        
                        ndp_packet_t reply;
                        
                        reply.opcode = ICMPV6_NEIGHBOUR_ADVERTISEMENT;
                        addr48(laddr->ilink->mac, reply.sender_hw_addr);
                        addr128(packet.target_proto_addr, reply.sender_proto_addr);
                        addr48(packet.sender_hw_addr, reply.target_hw_addr);
                        addr128(packet.sender_proto_addr, reply.target_proto_addr);
                        
                        ndp_send_packet(laddr->ilink, &reply);
                }
                
                break;
        case ICMPV6_NEIGHBOUR_ADVERTISEMENT:
                laddr = inet_addrobj_find(&dgram->dest, iaf_addr);
                if (laddr != NULL)
                        return ntrans_add(packet.sender_proto_addr,
                            packet.sender_hw_addr);
                
                break;
        case ICMPV6_ROUTER_ADVERTISEMENT:
                return ndp_router_advertisement(dgram, &sender);
        default:
                return ENOTSUP;
        }
        
        return EOK;
}

/** Translate IPv6 to MAC address
 *
 * @param src  Source IPv6 address
 * @param dest Destination IPv6 address
 * @param mac  Target MAC address to be assigned
 * @param link Network interface
 *
 * @return EOK on success
 * @return ENOENT when NDP translation failed
 *
 */
int ndp_translate(addr128_t src_addr, addr128_t ip_addr, addr48_t mac_addr,
    inet_link_t *ilink)
{
        if (!ilink->mac_valid) {
                /* The link does not support NDP */
                memset(mac_addr, 0, 6);
                return EOK;
        }
        
        int rc = ntrans_lookup(ip_addr, mac_addr);
        if (rc == EOK)
                return EOK;
        
        ndp_packet_t packet;
        
        packet.opcode = ICMPV6_NEIGHBOUR_SOLICITATION;
        addr48(ilink->mac, packet.sender_hw_addr);
        addr128(src_addr, packet.sender_proto_addr);
        addr128(ip_addr, packet.solicited_ip);
        addr48_solicited_node(ip_addr, packet.target_hw_addr);
        ndp_solicited_node_ip(ip_addr, packet.target_proto_addr);
        
        rc = ndp_send_packet(ilink, &packet);
        if (rc != EOK)
                return rc;
        
        (void) ntrans_wait_timeout(NDP_REQUEST_TIMEOUT);
        
        return ntrans_lookup(ip_addr, mac_addr);
}