xref: /linux/net/rxrpc/skbuff.c (revision 320fefa9e2edc67011e235ea1d50f0d00ddfe004)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* ar-skbuff.c: socket buffer destruction handling
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  */
22 void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
23 {
24 	const void *here = __builtin_return_address(0);
25 	int n = atomic_inc_return(select_skb_count(skb));
26 	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
27 }
28 
29 /*
30  * Note the re-emergence of a socket buffer from a queue or buffer.
31  */
32 void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
33 {
34 	const void *here = __builtin_return_address(0);
35 	if (skb) {
36 		int n = atomic_read(select_skb_count(skb));
37 		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
38 	}
39 }
40 
41 /*
42  * Note the addition of a ref on a socket buffer.
43  */
44 void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
45 {
46 	const void *here = __builtin_return_address(0);
47 	int n = atomic_inc_return(select_skb_count(skb));
48 	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
49 	skb_get(skb);
50 }
51 
52 /*
53  * Note the dropping of a ref on a socket buffer by the core.
54  */
55 void rxrpc_eaten_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
56 {
57 	const void *here = __builtin_return_address(0);
58 	int n = atomic_inc_return(&rxrpc_n_rx_skbs);
59 	trace_rxrpc_skb(skb, op, 0, n, here);
60 }
61 
62 /*
63  * Note the destruction of a socket buffer.
64  */
65 void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
66 {
67 	const void *here = __builtin_return_address(0);
68 	if (skb) {
69 		int n;
70 		n = atomic_dec_return(select_skb_count(skb));
71 		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
72 		kfree_skb(skb);
73 	}
74 }
75 
76 /*
77  * Clear a queue of socket buffers.
78  */
79 void rxrpc_purge_queue(struct sk_buff_head *list)
80 {
81 	const void *here = __builtin_return_address(0);
82 	struct sk_buff *skb;
83 	while ((skb = skb_dequeue((list))) != NULL) {
84 		int n = atomic_dec_return(select_skb_count(skb));
85 		trace_rxrpc_skb(skb, rxrpc_skb_purged,
86 				refcount_read(&skb->users), n, here);
87 		kfree_skb(skb);
88 	}
89 }
90