mld6igmp_vif.cc

MLDv2 support igmpv3 lite

    bool check_src_linklocal_unicast = false;
    bool allow_src_zero_address = false;
    bool check_dst_multicast = false;
    bool check_group_interfacelocal_multicast = false;
    bool decode_extra_fields = false;
    
    //
    // Message length check.
    //
    if (BUFFER_DATA_SIZE(buffer) < mld6igmp_constant_minlen()) {
	error_msg = c_format("RX packet from %s to %s on vif %s: "
			     "too short data field (%u octets)",
			     cstring(src), cstring(dst),
			     name().c_str(),
			     XORP_UINT_CAST(BUFFER_DATA_SIZE(buffer)));
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
    
    //
    // Checksum verification.
    //
    cksum = inet_checksum(BUFFER_DATA_HEAD(buffer), BUFFER_DATA_SIZE(buffer));
#ifdef HAVE_IPV6
    // Add the checksum for the IPv6 pseudo-header
    if (proto_is_mld6()) {
	uint16_t cksum2;
	size_t ph_len = BUFFER_DATA_SIZE(buffer);
	cksum2 = calculate_ipv6_pseudo_header_checksum(src, dst, ph_len,
						       IPPROTO_ICMPV6);
	cksum = inet_checksum_add(cksum, cksum2);
    }
#endif // HAVE_IPV6
    if (cksum) {
	error_msg = c_format("RX packet from %s to %s on vif %s: "
			     "checksum error",
			     cstring(src), cstring(dst),
			     name().c_str());
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
    
    //
    // Protocol version check.
    //
    // XXX: MLD and IGMP messages do not have an explicit field for protocol
    // version. Protocol version check is performed later, per (some) message
    // type.
    //
    
    //
    // Get the message type and the max. resp. time (in case of IGMP).
    //
    // Note that in case of IGMP the max. resp. time is the `igmp_code' field
    // in `struct igmp'.
    //
    if (proto_is_igmp()) {
	BUFFER_GET_OCTET(message_type, buffer);
	BUFFER_GET_OCTET(max_resp_code, buffer);
	BUFFER_GET_SKIP(2, buffer);		// The checksum
    }
    if (proto_is_mld6()) {
	BUFFER_GET_OCTET(message_type, buffer);
	BUFFER_GET_SKIP(1, buffer);		// The `Code' field: unused
	BUFFER_GET_SKIP(2, buffer);		// The `Checksum' field
    }

    XLOG_TRACE(mld6igmp_node().is_log_trace(),
	       "RX %s from %s to %s on vif %s",
	       proto_message_type2ascii(message_type),
	       cstring(src), cstring(dst),
	       name().c_str());

    //
    // Ignore messages that are not recognized by older protocol version.
    //
    // XXX: Unrecognized message types MUST be silently ignored.
    //
    if (proto_is_igmp()) {
	switch (message_type) {
	case IGMP_MEMBERSHIP_QUERY:
	    // Recognized by IGMPv1, IGMPv2, IGMPv3
	    break;
	case IGMP_V1_MEMBERSHIP_REPORT:
	    // Recognized by IGMPv1, IGMPv2, IGMPv3
	    break;
	case IGMP_V2_MEMBERSHIP_REPORT:
	    // Recognized by IGMPv2, IGMPv3
	    if (is_igmpv1_mode())
		return (XORP_ERROR);
	    break;
	case IGMP_V2_LEAVE_GROUP:
	    // Recognized by IGMPv2, IGMPv3
	    if (is_igmpv1_mode())
		return (XORP_ERROR);
	    break;
	case IGMP_V3_MEMBERSHIP_REPORT:
	    // Recognized by IGMPv3
	    if (is_igmpv1_mode() || is_igmpv2_mode())
		return (XORP_ERROR);
	    break;
	case IGMP_DVMRP:
	case IGMP_MTRACE:
	    break;
	default:
	    // Unrecognized message
	    return (XORP_ERROR);
	}
    }
    if (proto_is_mld6()) {
	switch (message_type) {
	case MLD_LISTENER_QUERY:
	    // Recognized by MLDv1, MLDv2
	    break;
	case MLD_LISTENER_REPORT:
	    // Recognized by MLDv1, MLDv2
	    break;
	case MLD_LISTENER_DONE:
	    // Recognized by MLDv1, MLDv2
	    break;
	case MLDV2_LISTENER_REPORT:
	    // Recognized by MLDv2
	    if (is_mldv1_mode())
		return (XORP_ERROR);
	    break;
	case MLD_MTRACE:
	    break;
	default:
	    // Unrecognized message
	    return (XORP_ERROR);
	}
    }

    //
    // Assign various flags what needs to be checked, based on the
    // message type:
    //  - check_router_alert_option
    //  - check_src_linklocal_unicast
    //  - allow_src_zero_address
    //  - check_dst_multicast
    //  - check_group_interfacelocal_multicast
    //  - decode_extra_fields
    //
    if (proto_is_igmp()) {
	switch (message_type) {
	case IGMP_MEMBERSHIP_QUERY:
	case IGMP_V1_MEMBERSHIP_REPORT:
	case IGMP_V2_MEMBERSHIP_REPORT:
	case IGMP_V2_LEAVE_GROUP:
	case IGMP_V3_MEMBERSHIP_REPORT:
	    if (_ip_router_alert_option_check.get())
		check_router_alert_option = true;
	    check_src_linklocal_unicast = false;	// Not needed for IPv4
	    if (is_igmpv3_mode()) {
		if ((message_type == IGMP_V1_MEMBERSHIP_REPORT)
		    || (message_type == IGMP_V2_MEMBERSHIP_REPORT)
		    || (message_type == IGMP_V3_MEMBERSHIP_REPORT)) {
		    allow_src_zero_address = true;	// True only for IGMPv3
		}
	    }
	    check_dst_multicast = true;
	    if (is_igmpv3_mode())
		check_dst_multicast = false;		// XXX: disable
	    check_group_interfacelocal_multicast = false;// Not needed for IPv4
	    decode_extra_fields = true;
	    if (message_type == IGMP_V3_MEMBERSHIP_REPORT)
		decode_extra_fields = false;
	    break;
	case IGMP_DVMRP:
	case IGMP_MTRACE:
	    // TODO: Assign the flags as appropriate
	    break;
	default:
	    break;
	}
    }

    if (proto_is_mld6()) {
	switch (message_type) {
	case MLD_LISTENER_QUERY:
	case MLD_LISTENER_REPORT:
	case MLD_LISTENER_DONE:
	case MLDV2_LISTENER_REPORT:
	    check_router_alert_option = true;
	    check_src_linklocal_unicast = true;
	    allow_src_zero_address = false;		// Always false for MLD
	    check_dst_multicast = true;
	    if (is_mldv2_mode())
		check_dst_multicast = false;		// XXX: disable
	    check_group_interfacelocal_multicast = true;
	    decode_extra_fields = true;
	    if (message_type == MLDV2_LISTENER_REPORT)
		decode_extra_fields = false;
	    break;
	case MLD_MTRACE:
	    // TODO: Assign the flags as appropriate
	    break;
	default:
	    break;
	}
    }

    //
    // Decode the extra fields: the max. resp. time (in case of MLD),
    // and the group address.
    //
    if (decode_extra_fields) {
	if (proto_is_igmp()) {
	    BUFFER_GET_IPVX(family(), group_address, buffer);
	}
	if (proto_is_mld6()) {
	    BUFFER_GET_HOST_16(max_resp_code, buffer);
	    BUFFER_GET_SKIP(2, buffer);		// The `Reserved' field
	    BUFFER_GET_IPVX(family(), group_address, buffer);
	}
    }

    //
    // IP Router Alert option check.
    //
    if (check_router_alert_option && (! ip_router_alert)) {
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "missing IP Router Alert option",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str());
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
    //
    // TODO: check the TTL, TOS and ip_internet_control flag if we are
    // running in secure mode.
    //
    UNUSED(ip_ttl);
    UNUSED(ip_tos);
    UNUSED(ip_internet_control);
#if 0
    if (ip_ttl != MINTTL) {
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "ip_ttl = %d instead of %d",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str(),
			     ip_ttl, MINTTL);
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
#endif // 0
    
    //
    // Source address check.
    //
    if (! src.is_unicast()) {
	//
	// Source address must always be unicast.
	// The kernel should have checked that, but just in case...
	//
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "source must be unicast",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str());
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
    if (src.af() != family()) {
	// Invalid source address family
	XLOG_WARNING("RX %s from %s to %s on vif %s: "
		     "invalid source address family "
		     "(received %d expected %d)",
		     proto_message_type2ascii(message_type),
		     cstring(src), cstring(dst),
		     name().c_str(),
		     src.af(), family());
    }
    // Source address must be directly connected
    if (! mld6igmp_node().is_directly_connected(*this, src)) {
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "source must be directly connected",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str());
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }
    if (check_src_linklocal_unicast) {
	if (src.is_linklocal_unicast()
	    || (allow_src_zero_address && src.is_zero())) {
	    // The source address is link-local or (allowed) zero address
	} else {
	    // The source address is not link-local
	    error_msg = c_format("RX %s from %s to %s on vif %s: "
				 "source is not a link-local address",
				 proto_message_type2ascii(message_type),
				 cstring(src), cstring(dst),
				 name().c_str());
	    XLOG_WARNING("%s", error_msg.c_str());
	    return (XORP_ERROR);
	}
    }

    //
    // Destination address check.
    //
    if (dst.af() != family()) {
	// Invalid destination address family
	XLOG_WARNING("RX %s from %s to %s on vif %s: "
		     "invalid destination address family "
		     "(received %d expected %d)",
		     proto_message_type2ascii(message_type),
		     cstring(src), cstring(dst),
		     name().c_str(),
		     dst.af(), family());
    }
    if (check_dst_multicast && (! dst.is_multicast())) {
	// The destination address is not multicast
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "destination must be multicast. "
			     "Packet ignored.",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str());
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }

    //
    // Inner multicast address scope check.
    //
    if (check_group_interfacelocal_multicast
	&& group_address.is_interfacelocal_multicast()) {
	error_msg = c_format("RX %s from %s to %s on vif %s: "
			     "invalid interface-local scope of inner "
			     "multicast address: %s",
			     proto_message_type2ascii(message_type),
			     cstring(src), cstring(dst),
			     name().c_str(),
			     cstring(group_address));
	XLOG_WARNING("%s", error_msg.c_str());
	return (XORP_ERROR);
    }

    //
    // Origin router neighbor check.
    //
    // XXX: in IGMP and MLD we don't need such check
    
    //
    // Process each message, based on its type.
    //
    if (proto_is_igmp()) {
	switch (message_type) {
	case IGMP_MEMBERSHIP_QUERY:
	    mld6igmp_membership_query_recv(src, dst,
					   message_type, max_resp_code,
					   group_address, buffer);
	    break;
	case IGMP_V1_MEMBERSHIP_REPORT:
	case IGMP_V2_MEMBERSHIP_REPORT:
	    mld6igmp_membership_report_recv(src, dst,
					    message_type, max_resp_code,
					    group_address, buffer);
	    break;
	case IGMP_V2_LEAVE_GROUP:
	    mld6igmp_leave_group_recv(src, dst,
				      message_type, max_resp_code,
				      group_address, buffer);
	    break;
	case IGMP_V3_MEMBERSHIP_REPORT:
	    mld6igmp_ssm_membership_report_recv(src, dst, message_type,
						buffer);
	    break;
	case IGMP_DVMRP:
	{
	    //
	    // XXX: We care only about the DVMRP messages that are used
	    // by mrinfo.
	    //
	    // XXX: the older purpose of the 'igmp_code' field
	    uint16_t igmp_code = max_resp_code;
	    switch (igmp_code) {
	    case DVMRP_ASK_NEIGHBORS:
		// Some old DVMRP messages from mrinfo(?).
		// TODO: not implemented yet.
		// TODO: do we really need this message implemented?
		break;
	    case DVMRP_ASK_NEIGHBORS2:
		// Used for mrinfo support.
		// XXX: not implemented yet.
		break;
	    case DVMRP_INFO_REQUEST:
		// Information request (TODO: used by mrinfo?)
		// TODO: not implemented yet.
		break;
	    default:
		// XXX: We don't care about the rest of the DVMRP_* messages
		break;
	    }
	}
	case IGMP_MTRACE:
	    // TODO: is this the new message sent by 'mtrace'?
	    // TODO: not implemented yet.
	    break;
	default:
	    // XXX: Unrecognized message types MUST be silently ignored.
	    break;
	}
    }

    if (proto_is_mld6()) {
	switch (message_type) {
	case MLD_LISTENER_QUERY:
	    mld6igmp_membership_query_recv(src, dst,
					   message_type, max_resp_code,
					   group_address, buffer);
	    break;
	case MLD_LISTENER_REPORT:
	    mld6igmp_membership_report_recv(src, dst,
					    message_type, max_resp_code,
					    group_address, buffer);
	    break;
	case MLD_LISTENER_DONE:
	    mld6igmp_leave_group_recv(src, dst,
				      message_type, max_resp_code,
				      group_address, buffer);
	    break;
	case MLDV2_LISTENER_REPORT:
	    mld6igmp_ssm_membership_report_recv(src, dst, message_type,
						buffer);
	    break;
	case MLD_MTRACE:
	    // TODO: is this the new message sent by 'mtrace'?
	    // TODO: not implemented yet.
	    break;
	default:
	    // XXX: Unrecognized message types MUST be silently ignored.
	    break;
	}
    }

    return (XORP_OK);

 rcvlen_error:
    XLOG_UNREACHABLE();
    error_msg = c_format("RX packet from %s to %s on vif %s: "
			 "some fields are too short",
			 cstring(src), cstring(dst),
			 name().c_str());
    XLOG_WARNING("%s", error_msg.c_str());
    return (XORP_ERROR);
}

/**
 * Mld6igmpVif::update_primary_address:
 * @error_msg: The error message (if error).
 * 
 * Update the primary address.
 * 
 * The primary address should be a link-local unicast address, and
 * is used for transmitting the multicast control packets on the LAN.
 * 
 * Return value: %XORP_OK on success, otherwise %XORP_ERROR.
 **/
int
Mld6igmpVif::update_primary_address(string& error_msg)
{
    bool i_was_querier = false;
    IPvX primary_a(IPvX::ZERO(family()));
    IPvX domain_wide_a(IPvX::ZERO(family()));