/* ar-skbuff.c: socket buffer destruction handling
   *
   * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */

  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #include <linux/module.h>
  #include <linux/net.h>
  #include <linux/skbuff.h>
  #include <net/sock.h>
  #include <net/af_rxrpc.h>
  #include "ar-internal.h"

  #define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)

  /*

   * Note the allocation or reception of a socket buffer.

   */

  void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)

  {
  	const void *here = __builtin_return_address(0);

  	int n = atomic_inc_return(select_skb_count(op));

  	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);

  }
  
  /*
   * Note the re-emergence of a socket buffer from a queue or buffer.
   */

  void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)

  {
  	const void *here = __builtin_return_address(0);
  	if (skb) {

  		int n = atomic_read(select_skb_count(op));

  		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);

  	}
  }
  
  /*
   * Note the addition of a ref on a socket buffer.
   */

  void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)

  {
  	const void *here = __builtin_return_address(0);

  	int n = atomic_inc_return(select_skb_count(op));

  	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);

  	skb_get(skb);
  }
  
  /*
   * Note the destruction of a socket buffer.
   */

  void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)

  {
  	const void *here = __builtin_return_address(0);
  	if (skb) {
  		int n;
  		CHECK_SLAB_OKAY(&skb->users);

  		n = atomic_dec_return(select_skb_count(op));

  		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);

  		kfree_skb(skb);
  	}
  }
  
  /*

   * Note the injected loss of a socket buffer.
   */
  void rxrpc_lose_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  {
  	const void *here = __builtin_return_address(0);
  	if (skb) {
  		int n;
  		CHECK_SLAB_OKAY(&skb->users);

  		n = atomic_dec_return(select_skb_count(op));

  		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);

  		kfree_skb(skb);

  	}
  }
  
  /*

   * Clear a queue of socket buffers.
   */
  void rxrpc_purge_queue(struct sk_buff_head *list)
  {
  	const void *here = __builtin_return_address(0);
  	struct sk_buff *skb;
  	while ((skb = skb_dequeue((list))) != NULL) {

  		int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
  		trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,

  				refcount_read(&skb->users), n, here);

  		kfree_skb(skb);
  	}
  }