1/* ar-skbuff.c: socket buffer destruction handling
 2 *
 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 4 * Written by David Howells (dhowells@redhat.com)
 5 *
 6 * This program is free software; you can redistribute it and/or
 7 * modify it under the terms of the GNU General Public License
 8 * as published by the Free Software Foundation; either version
 9 * 2 of the License, or (at your option) any later version.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/module.h>
15#include <linux/net.h>
16#include <linux/skbuff.h>
17#include <net/sock.h>
18#include <net/af_rxrpc.h>
19#include "ar-internal.h"
20
21#define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
22
23/*
24 * Note the allocation or reception of a socket buffer.
25 */
26void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
27{
28	const void *here = __builtin_return_address(0);
29	int n = atomic_inc_return(select_skb_count(op));
30	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
31}
32
33/*
34 * Note the re-emergence of a socket buffer from a queue or buffer.
35 */
36void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
37{
38	const void *here = __builtin_return_address(0);
39	if (skb) {
40		int n = atomic_read(select_skb_count(op));
41		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
42	}
43}
44
45/*
46 * Note the addition of a ref on a socket buffer.
47 */
48void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
49{
50	const void *here = __builtin_return_address(0);
51	int n = atomic_inc_return(select_skb_count(op));
52	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
53	skb_get(skb);
54}
55
56/*
57 * Note the destruction of a socket buffer.
58 */
59void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
60{
61	const void *here = __builtin_return_address(0);
62	if (skb) {
63		int n;
64		CHECK_SLAB_OKAY(&skb->users);
65		n = atomic_dec_return(select_skb_count(op));
66		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
67		kfree_skb(skb);
68	}
69}
70
71/*
72 * Note the injected loss of a socket buffer.
73 */
74void rxrpc_lose_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
75{
76	const void *here = __builtin_return_address(0);
77	if (skb) {
78		int n;
79		CHECK_SLAB_OKAY(&skb->users);
80		n = atomic_dec_return(select_skb_count(op));
81		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
82		kfree_skb(skb);
83	}
84}
85
86/*
87 * Clear a queue of socket buffers.
88 */
89void rxrpc_purge_queue(struct sk_buff_head *list)
90{
91	const void *here = __builtin_return_address(0);
92	struct sk_buff *skb;
93	while ((skb = skb_dequeue((list))) != NULL) {
94		int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
95		trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,
96				refcount_read(&skb->users), n, here);
97		kfree_skb(skb);
98	}
99}