예제 #1
0
/*
 * handle unicast arp requests and neighbor refreshes. In many cases,
 * we wouldn't like the unicast arp requests from gateway (such as MX)
 * to reach the VMs and change the gateway mac to ip(6) binding, since
 * for vms the gateway is always agent. We would like such requests
 * to go only if the mode is l2
 */
int
vif_plug_mac_request(struct vr_interface *vif, struct vr_packet *pkt,
        struct vr_forwarding_md *fmd)
{
    int handled = 1;
    int nheader;

    struct vr_arp *sarp;

    if (pkt->vp_flags & VP_FLAG_MULTICAST)
        goto unhandled;

    nheader = pkt_network_header(pkt) - pkt_data(pkt);
    if (nheader < 0 || (pkt->vp_data + nheader > pkt->vp_end))
        goto unhandled;

    if (pkt->vp_type == VP_TYPE_ARP) {
        if (pkt->vp_len < (nheader + sizeof(*sarp)))
            goto unhandled;

        sarp = (struct vr_arp *)(pkt_data(pkt) + nheader);
        if (ntohs(sarp->arp_op) != VR_ARP_OP_REQUEST)
            goto unhandled;

        pkt_pull(pkt, nheader);

        handled = vr_arp_input(pkt, fmd);
        if (!handled) {
            pkt_push(pkt, nheader);
        }
        return handled;
    } else if (pkt->vp_type == VP_TYPE_IP6) {
        if (pkt->vp_len < (nheader + sizeof(struct vr_ip6) +
                    sizeof(struct vr_icmp) + VR_IP6_ADDRESS_LEN +
                    sizeof(struct vr_neighbor_option) + VR_ETHER_ALEN))
            goto unhandled;

        pkt_pull(pkt, nheader);

        handled = vr_neighbor_input(pkt, fmd);
        if (!handled) {
            pkt_push(pkt, nheader);
        }
        return handled;
    }

unhandled:
    return !handled;
}
예제 #2
0
unsigned int
vr_bridge_input(struct vrouter *router, struct vr_packet *pkt,
                struct vr_forwarding_md *fmd)
{
    int reason, handled;
    l4_pkt_type_t l4_type = L4_TYPE_UNKNOWN;
    unsigned short pull_len, overlay_len = VROUTER_OVERLAY_LEN;

    int8_t *dmac;
    struct vr_bridge_entry *be;
    struct vr_nexthop *nh = NULL;
    struct vr_vrf_stats *stats;

    dmac = (int8_t *) pkt_data(pkt);

    if (pkt->vp_if->vif_flags & VIF_FLAG_MAC_LEARN) {
        if (vr_bridge_learn(router, pkt, fmd)) {
            return 0;
        }
    }

    pull_len = 0;
    if ((pkt->vp_type == VP_TYPE_IP) || (pkt->vp_type == VP_TYPE_IP6) ||
            (pkt->vp_type == VP_TYPE_ARP)) {
        pull_len = pkt_get_network_header_off(pkt) - pkt_head_space(pkt);
        if (pull_len && !pkt_pull(pkt, pull_len)) {
            vr_pfree(pkt, VP_DROP_PULL);
            return 0;
        }
    }

    if ((pkt->vp_type == VP_TYPE_IP) || (pkt->vp_type == VP_TYPE_IP6)) {
        if (fmd->fmd_dscp < 0) {
            if (pkt->vp_type == VP_TYPE_IP) {
                fmd->fmd_dscp =
                    vr_inet_get_tos((struct vr_ip *)pkt_network_header(pkt));
            } else if (pkt->vp_type == VP_TYPE_IP6) {
                fmd->fmd_dscp =
                    vr_inet6_get_tos((struct vr_ip6 *)pkt_network_header(pkt));
            }
        }
    } else {
        if (fmd->fmd_dotonep < 0) {
            fmd->fmd_dotonep = vr_vlan_get_tos(pkt_data(pkt));
        }
    }

    /* Do the bridge lookup for the packets not meant for "me" */
    if (!fmd->fmd_to_me) {
        /*
         * If DHCP packet coming from VM, Trap it to Agent before doing the bridge
         * lookup itself
         */
        if (vif_is_virtual(pkt->vp_if)) {
            if (pkt->vp_type == VP_TYPE_IP)
                l4_type = vr_ip_well_known_packet(pkt);
            else if (pkt->vp_type == VP_TYPE_IP6)
                l4_type = vr_ip6_well_known_packet(pkt);

            if (l4_type == L4_TYPE_DHCP_REQUEST) {
                if (pkt->vp_if->vif_flags & VIF_FLAG_DHCP_ENABLED) {
                    vr_trap(pkt, fmd->fmd_dvrf,  AGENT_TRAP_L3_PROTOCOLS, NULL);
                    return 0;
                }
            }

            /*
             * Handle the unicast ARP, coming from VM, not
             * destined to us. Broadcast ARP requests would be handled
             * in L2 multicast nexthop. Multicast ARP on fabric
             * interface also would be handled in L2 multicast nexthop.
             * Unicast ARP packets on fabric interface would be handled
             * in plug routines of interface.
             */
            if (!IS_MAC_BMCAST(dmac)) {
                handled = 0;
                if (pkt->vp_type == VP_TYPE_ARP) {
                    handled = vr_arp_input(pkt, fmd, dmac);
                } else if (l4_type == L4_TYPE_NEIGHBOUR_SOLICITATION) {
                    handled = vr_neighbor_input(pkt, fmd, dmac);
                }

                if (handled)
                    return 0;
            }
        }

        be = bridge_lookup(dmac, fmd);
        if (be)
            nh = be->be_nh;

        if (!nh || nh->nh_type == NH_DISCARD) {

            /* If Flooding of unknown unicast not allowed, drop the packet */
            if (!vr_unknown_uc_flood(pkt->vp_if, pkt->vp_nh) ||
                                 IS_MAC_BMCAST(dmac)) {
                vr_pfree(pkt, VP_DROP_L2_NO_ROUTE);
                return 0;
            }

            be = bridge_lookup(vr_bcast_mac, fmd);
            nh = be->be_nh;
            if (!nh) {
                vr_pfree(pkt, VP_DROP_L2_NO_ROUTE);
                return 0;
            }
            stats = vr_inet_vrf_stats(fmd->fmd_dvrf, pkt->vp_cpu);
            if (stats)
                stats->vrf_uuc_floods++;

            /* Treat this unknown unicast packet as multicast */
            pkt->vp_flags |= VP_FLAG_MULTICAST;
        }

        if (be)
            __sync_fetch_and_add(&be->be_packets, 1);

        if (nh->nh_type != NH_L2_RCV)
            overlay_len = VROUTER_L2_OVERLAY_LEN;
    }


    /* Adjust MSS for V4 and V6 packets */
    if ((pkt->vp_type == VP_TYPE_IP) || (pkt->vp_type == VP_TYPE_IP6)) {

        if (vif_is_virtual(pkt->vp_if) &&
                vr_from_vm_mss_adj && vr_pkt_from_vm_tcp_mss_adj) {

            if ((reason = vr_pkt_from_vm_tcp_mss_adj(pkt, overlay_len))) {
                vr_pfree(pkt, reason);
                return 0;
            }
        }

        if (fmd->fmd_to_me) {
            handled = vr_l3_input(pkt, fmd);
            if (!handled) {
                vr_pfree(pkt, VP_DROP_NOWHERE_TO_GO);
            }
            return 0;
        }
    }

    if (pull_len && !pkt_push(pkt, pull_len)) {
        vr_pfree(pkt, VP_DROP_PUSH);
        return 0;
    }

    nh_output(pkt, nh, fmd);
    return 0;
}