Restore SVP_R_ROUTE_REQ, and all that goes with it.
Interpret sl3a_uport == 0 in SVP_R_VL3_ACK to indicate the VL3 IP is a next-hop router.

*** 72,83 ****
          svp_vl2_ack_t   sqd_vl2a;
          svp_vl3_req_t   sdq_vl3r;
          svp_vl3_ack_t   sdq_vl3a;
          svp_log_req_t   sdq_logr;
          svp_lrm_ack_t   sdq_lrma;
!         svp_rvl3_req_t  sqd_rvl3r;
!         svp_rvl3_ack_t  sqd_rvl3a;
  } svp_query_data_t;
  
  typedef void (*svp_query_f)(svp_query_t *, void *);
  
  typedef enum svp_query_state {
--- 72,83 ----
          svp_vl2_ack_t   sqd_vl2a;
          svp_vl3_req_t   sdq_vl3r;
          svp_vl3_ack_t   sdq_vl3a;
          svp_log_req_t   sdq_logr;
          svp_lrm_ack_t   sdq_lrma;
!         svp_route_req_t sqd_rr;
!         svp_route_ack_t sqd_ra;
  } svp_query_data_t;
  
  typedef void (*svp_query_f)(svp_query_t *, void *);
  
  typedef enum svp_query_state {
*** 245,264 ****
  typedef void (*svp_vl2_invalidation_f)(svp_t *, const uint8_t *);
  typedef void (*svp_vl3_inject_f)(svp_t *, const uint16_t,
      const struct in6_addr *, const uint8_t *, const uint8_t *);
  typedef void (*svp_shootdown_f)(svp_t *, const uint8_t *,
      const struct in6_addr *, const uint16_t uport);
! /* XXX KEBE SAYS FILL ME IN! */
! typedef void (*svp_rvl3_lookup_f)(svp_t *, svp_status_t, void *);
  
  typedef struct svp_cb {
          svp_vl2_lookup_f        scb_vl2_lookup;
          svp_vl3_lookup_f        scb_vl3_lookup;
          svp_vl2_invalidation_f  scb_vl2_invalidate;
          svp_vl3_inject_f        scb_vl3_inject;
          svp_shootdown_f         scb_shootdown;
!         svp_rvl3_lookup_f       scb_rvl3_lookup;
  } svp_cb_t;
  
  /*
   * Core implementation structure.
   */
--- 245,265 ----
  typedef void (*svp_vl2_invalidation_f)(svp_t *, const uint8_t *);
  typedef void (*svp_vl3_inject_f)(svp_t *, const uint16_t,
      const struct in6_addr *, const uint8_t *, const uint8_t *);
  typedef void (*svp_shootdown_f)(svp_t *, const uint8_t *,
      const struct in6_addr *, const uint16_t uport);
! typedef void (*svp_route_lookup_f)(svp_t *, svp_status_t, uint32_t, uint32_t,
!     uint16_t, uint8_t *, uint8_t *, uint16_t, uint8_t *, uint8_t, uint8_t,
!     void *);
  
  typedef struct svp_cb {
          svp_vl2_lookup_f        scb_vl2_lookup;
          svp_vl3_lookup_f        scb_vl3_lookup;
          svp_vl2_invalidation_f  scb_vl2_invalidate;
          svp_vl3_inject_f        scb_vl3_inject;
          svp_shootdown_f         scb_shootdown;
!         svp_route_lookup_f      scb_route_lookup;
  } svp_cb_t;
  
  /*
   * Core implementation structure.
   */
*** 274,284 ****
          uint16_t                svp_port;       /* svp_lock */
          uint16_t                svp_uport;      /* svp_lock */
          uint32_t                svp_dcid;       /* svp_lock (but write-once?) */
          boolean_t               svp_huip;       /* svp_lock */
          struct in6_addr         svp_uip;        /* svp_lock */
!         struct ether_addr       svp_router_mac; /* svp_lock (but write-once?) */
  };
  
  extern bunyan_logger_t *svp_bunyan;
  
  extern int svp_remote_find(char *, uint16_t, struct in6_addr *,
--- 275,286 ----
          uint16_t                svp_port;       /* svp_lock */
          uint16_t                svp_uport;      /* svp_lock */
          uint32_t                svp_dcid;       /* svp_lock (but write-once?) */
          boolean_t               svp_huip;       /* svp_lock */
          struct in6_addr         svp_uip;        /* svp_lock */
!         /* NOTE: lower-3 bytes are 0s. */
!         uint8_t         svp_router_oui[6];      /* svp_lock (but write-once?) */
  };
  
  extern bunyan_logger_t *svp_bunyan;
  
  extern int svp_remote_find(char *, uint16_t, struct in6_addr *,
*** 288,299 ****
  extern void svp_remote_release(svp_remote_t *);
  extern void svp_remote_vl3_lookup(svp_t *, svp_query_t *,
      const struct sockaddr *, void *);
  extern void svp_remote_vl2_lookup(svp_t *, svp_query_t *, const uint8_t *,
      void *);
! extern void svp_remote_rvl3_lookup(svp_t *, svp_query_t *,
!     const struct in6_addr *, const struct in6_addr *, uint32_t, uint32_t,
      uint16_t, void *);
  
  
  /*
   * Init functions
--- 290,301 ----
  extern void svp_remote_release(svp_remote_t *);
  extern void svp_remote_vl3_lookup(svp_t *, svp_query_t *,
      const struct sockaddr *, void *);
  extern void svp_remote_vl2_lookup(svp_t *, svp_query_t *, const uint8_t *,
      void *);
! extern void svp_remote_route_lookup(svp_t *, svp_query_t *,
!     const struct in6_addr *, const struct in6_addr *, uint32_t,
      uint16_t, void *);
  
  
  /*
   * Init functions