xref: /linux/net/rxrpc/skbuff.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
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(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &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(op));
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(op));
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(op));
48 	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
49 	skb_get(skb);
50 }
51 
52 /*
53  * Note the destruction of a socket buffer.
54  */
55 void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
56 {
57 	const void *here = __builtin_return_address(0);
58 	if (skb) {
59 		int n;
60 		CHECK_SLAB_OKAY(&skb->users);
61 		n = atomic_dec_return(select_skb_count(op));
62 		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n, here);
63 		kfree_skb(skb);
64 	}
65 }
66 
67 /*
68  * Clear a queue of socket buffers.
69  */
70 void rxrpc_purge_queue(struct sk_buff_head *list)
71 {
72 	const void *here = __builtin_return_address(0);
73 	struct sk_buff *skb;
74 	while ((skb = skb_dequeue((list))) != NULL) {
75 		int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
76 		trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,
77 				refcount_read(&skb->users), n, here);
78 		kfree_skb(skb);
79 	}
80 }
81