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.

*** 243,254 ****
                  libvarpd_panic("missing callback scb_vl3_lookup");
          if (svp->svp_cb.scb_vl2_invalidate == NULL)
                  libvarpd_panic("missing callback scb_vl2_invalidate");
          if (svp->svp_cb.scb_vl3_inject == NULL)
                  libvarpd_panic("missing callback scb_vl3_inject");
!         if (svp->svp_cb.scb_rvl3_lookup == NULL)
!                 libvarpd_panic("missing callback scb_rvl3_lookup");
  
          check.svp_vid = svp->svp_vid;
          if (avl_find(&srp->sr_tree, &check, &where) != NULL)
                  libvarpd_panic("found duplicate entry with vid %ld",
                      svp->svp_vid);
--- 243,254 ----
                  libvarpd_panic("missing callback scb_vl3_lookup");
          if (svp->svp_cb.scb_vl2_invalidate == NULL)
                  libvarpd_panic("missing callback scb_vl2_invalidate");
          if (svp->svp_cb.scb_vl3_inject == NULL)
                  libvarpd_panic("missing callback scb_vl3_inject");
!         if (svp->svp_cb.scb_route_lookup == NULL)
!                 libvarpd_panic("missing callback scb_route_lookup");
  
          check.svp_vid = svp->svp_vid;
          if (avl_find(&srp->sr_tree, &check, &where) != NULL)
                  libvarpd_panic("found duplicate entry with vid %ld",
                      svp->svp_vid);
*** 352,403 ****
                  svp->svp_cb.scb_vl2_lookup(svp, SVP_S_FATAL, NULL, NULL, arg);
          mutex_exit(&srp->sr_lock);
  }
  
  static void
! svp_remote_rvl3_lookup_cb(svp_query_t *sqp, void *arg)
  {
          svp_t *svp = sqp->sq_svp;
!         svp_rvl3_ack_t *rvl3a = (svp_rvl3_ack_t *)sqp->sq_wdata;
  
          if (sqp->sq_status == SVP_S_OK) {
!                 svp->svp_cb.scb_rvl3_lookup(svp, sqp->sq_status,
!                     /* XXX KEBE SAYS MORE HERE */ arg);
          } else {
          }
  }
  
  void
! svp_remote_rvl3_lookup(svp_t *svp, svp_query_t *sqp, const struct in6_addr *src,
!     const struct in6_addr *dst, uint32_t type, uint32_t vnetid, uint16_t vlan,
!     void *arg)
  {
          svp_remote_t *srp;
!         svp_rvl3_req_t *rvl3r = &sqp->sq_rdun.sqd_rvl3r;
  
          srp = svp->svp_remote;
!         sqp->sq_func = svp_remote_rvl3_lookup_cb;
          sqp->sq_arg = arg;
          sqp->sq_svp = svp;
          sqp->sq_state = SVP_QUERY_INIT;
          sqp->sq_header.svp_ver = htons(SVP_CURRENT_VERSION);
!         sqp->sq_header.svp_op = htons(SVP_R_REMOTE_VL3_REQ);
!         sqp->sq_header.svp_size = htonl(sizeof (svp_vl2_req_t));
          sqp->sq_header.svp_id = id_alloc(svp_idspace);
          if (sqp->sq_header.svp_id == (id_t)-1)
                  libvarpd_panic("failed to allcoate from svp_idspace: %d",
                      errno);
          sqp->sq_header.svp_crc32 = htonl(0);
!         sqp->sq_rdata = rvl3r;
  
!         bcopy(src, rvl3r->srl3r_srcip, sizeof (struct in6_addr));
!         bcopy(dst, rvl3r->srl3r_dstip, sizeof (struct in6_addr));
          /* Caller should've checked both are the same type... */
!         rvl3r->srl3r_type = type;
!         rvl3r->srl3r_vnetid = vnetid;
!         rvl3r->srl3r_vlan = vlan;
!         rvl3r->srl3r_pad = 0;
  
          mutex_enter(&srp->sr_lock);
          if (!svp_remote_conn_queue(srp, sqp)) {
                  sqp->sq_status = SVP_S_FATAL;
                  sqp->sq_func(sqp, arg);
--- 352,406 ----
                  svp->svp_cb.scb_vl2_lookup(svp, SVP_S_FATAL, NULL, NULL, arg);
          mutex_exit(&srp->sr_lock);
  }
  
  static void
! svp_remote_route_lookup_cb(svp_query_t *sqp, void *arg)
  {
          svp_t *svp = sqp->sq_svp;
!         svp_route_ack_t *sra = (svp_route_ack_t *)sqp->sq_wdata;
  
          if (sqp->sq_status == SVP_S_OK) {
!                 svp->svp_cb.scb_route_lookup(svp, sqp->sq_status,
!                     sra->sra_dcid, sra->sra_vnetid, sra->sra_vlan,
!                     sra->sra_srcmac, sra->sra_dstmac, sra->sra_port,
!                     sra->sra_ip, sra->sra_src_pfx, sra->sra_dst_pfx, arg);
          } else {
+                 svp->svp_cb.scb_route_lookup(svp, sqp->sq_status,
+                     0, 0, 0, NULL, NULL, 0, NULL, 0, 0, arg);
          }
  }
  
  void
! svp_remote_route_lookup(svp_t *svp, svp_query_t *sqp,
!     const struct in6_addr *src, const struct in6_addr *dst, uint32_t vnetid,
!     uint16_t vlan, void *arg)
  {
          svp_remote_t *srp;
!         svp_route_req_t *srr = &sqp->sq_rdun.sqd_rr;
  
          srp = svp->svp_remote;
!         sqp->sq_func = svp_remote_route_lookup_cb;
          sqp->sq_arg = arg;
          sqp->sq_svp = svp;
          sqp->sq_state = SVP_QUERY_INIT;
          sqp->sq_header.svp_ver = htons(SVP_CURRENT_VERSION);
!         sqp->sq_header.svp_op = htons(SVP_R_ROUTE_REQ);
!         sqp->sq_header.svp_size = htonl(sizeof (svp_route_req_t));
          sqp->sq_header.svp_id = id_alloc(svp_idspace);
          if (sqp->sq_header.svp_id == (id_t)-1)
                  libvarpd_panic("failed to allcoate from svp_idspace: %d",
                      errno);
          sqp->sq_header.svp_crc32 = htonl(0);
!         sqp->sq_rdata = srr;
  
!         bcopy(src, srr->srr_srcip, sizeof (struct in6_addr));
!         bcopy(dst, srr->srr_dstip, sizeof (struct in6_addr));
          /* Caller should've checked both are the same type... */
!         srr->srr_vnetid = vnetid;
!         srr->srr_vlan = vlan;
!         srr->srr_pad = 0;
  
          mutex_enter(&srp->sr_lock);
          if (!svp_remote_conn_queue(srp, sqp)) {
                  sqp->sq_status = SVP_S_FATAL;
                  sqp->sq_func(sqp, arg);