*** 22,32 ****
  /*
   * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
   */
  /*
   * Copyright 2014, OmniTI Computer Consulting, Inc. All rights reserved.
-  * Copyright 2015 Joyent, Inc.
   */
  
  #include <sys/types.h>
  #include <sys/param.h>
  #include <sys/signal.h>
--- 22,31 ----
*** 2290,2302 ****
          error = 0;
          sp = so->so_sockparams;
          fbfunc = sp->sp_smod_info->smod_proto_fallback_func;
  
          /*
!          * Cannot fallback if the socket has active filters or a krecv callback.
           */
!         if (so->so_filter_active > 0 || so->so_krecv_cb != NULL)
                  return (EINVAL);
  
          switch (so->so_family) {
          case AF_INET:
                  devpath = sp->sp_smod_info->smod_fallback_devpath_v4;
--- 2289,2301 ----
          error = 0;
          sp = so->so_sockparams;
          fbfunc = sp->sp_smod_info->smod_proto_fallback_func;
  
          /*
!          * Cannot fallback if the socket has active filters
           */
!         if (so->so_filter_active > 0)
                  return (EINVAL);
  
          switch (so->so_family) {
          case AF_INET:
                  devpath = sp->sp_smod_info->smod_fallback_devpath_v4;
*** 2469,2521 ****
                  freemsg(arg.soqa_exdata_mp);
          if (arg.soqa_urgmark_mp != NULL)
                  freemsg(arg.soqa_urgmark_mp);
  
          return (error);
- }
- 
- int
- so_krecv_set(sonode_t *so, so_krecv_f cb, void *arg)
- {
-         int ret;
- 
-         if (cb == NULL && arg != NULL)
-                 return (EINVAL);
- 
-         SO_BLOCK_FALLBACK(so, so_krecv_set(so, cb, arg));
- 
-         mutex_enter(&so->so_lock);
-         if (so->so_state & SS_FALLBACK_COMP) {
-                 mutex_exit(&so->so_lock);
-                 SO_UNBLOCK_FALLBACK(so);
-                 return (ENOTSUP);
-         }
- 
-         ret = so_lock_read(so, 0);
-         VERIFY(ret == 0);
-         /*
-          * Other consumers may actually care about getting extant data delivered
-          * to them, when they come along, they should figure out the best API
-          * for that.
-          */
-         so_rcv_flush(so);
- 
-         so->so_krecv_cb = cb;
-         so->so_krecv_arg = arg;
- 
-         so_unlock_read(so);
-         mutex_exit(&so->so_lock);
-         SO_UNBLOCK_FALLBACK(so);
- 
-         return (0);
- }
- 
- void
- so_krecv_unblock(sonode_t *so)
- {
-         mutex_enter(&so->so_lock);
-         VERIFY(so->so_krecv_cb != NULL);
- 
-         so->so_rcv_queued = 0;
-         (void) so_check_flow_control(so);
-         mutex_exit(&so->so_lock);
  }
--- 2468,2473 ----