1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /* Socket buffer accounting
3   *
4   * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5   * Written by David Howells (dhowells@redhat.com)
6   */
7  
8  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9  
10  #include <linux/module.h>
11  #include <linux/net.h>
12  #include <linux/skbuff.h>
13  #include <net/sock.h>
14  #include <net/af_rxrpc.h>
15  #include "ar-internal.h"
16  
17  #define select_skb_count(skb) (&rxrpc_n_rx_skbs)
18  
19  /*
20   * Note the allocation or reception of a socket buffer.
21   */
rxrpc_new_skb(struct sk_buff * skb,enum rxrpc_skb_trace why)22  void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
23  {
24  	int n = atomic_inc_return(select_skb_count(skb));
25  	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
26  }
27  
28  /*
29   * Note the re-emergence of a socket buffer from a queue or buffer.
30   */
rxrpc_see_skb(struct sk_buff * skb,enum rxrpc_skb_trace why)31  void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
32  {
33  	if (skb) {
34  		int n = atomic_read(select_skb_count(skb));
35  		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
36  	}
37  }
38  
39  /*
40   * Note the addition of a ref on a socket buffer.
41   */
rxrpc_get_skb(struct sk_buff * skb,enum rxrpc_skb_trace why)42  void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
43  {
44  	int n = atomic_inc_return(select_skb_count(skb));
45  	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
46  	skb_get(skb);
47  }
48  
49  /*
50   * Note the dropping of a ref on a socket buffer by the core.
51   */
rxrpc_eaten_skb(struct sk_buff * skb,enum rxrpc_skb_trace why)52  void rxrpc_eaten_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
53  {
54  	int n = atomic_inc_return(&rxrpc_n_rx_skbs);
55  	trace_rxrpc_skb(skb, 0, n, why);
56  }
57  
58  /*
59   * Note the destruction of a socket buffer.
60   */
rxrpc_free_skb(struct sk_buff * skb,enum rxrpc_skb_trace why)61  void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
62  {
63  	if (skb) {
64  		int n = atomic_dec_return(select_skb_count(skb));
65  		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
66  		consume_skb(skb);
67  	}
68  }
69  
70  /*
71   * Clear a queue of socket buffers.
72   */
rxrpc_purge_queue(struct sk_buff_head * list)73  void rxrpc_purge_queue(struct sk_buff_head *list)
74  {
75  	struct sk_buff *skb;
76  
77  	while ((skb = skb_dequeue((list))) != NULL) {
78  		int n = atomic_dec_return(select_skb_count(skb));
79  		trace_rxrpc_skb(skb, refcount_read(&skb->users), n,
80  				rxrpc_skb_put_purge);
81  		consume_skb(skb);
82  	}
83  }
84