LXR linux/net/rxrpc/skbuff.c

   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 is_tx_skb(skb) (rxrpc_skb(skb)->rx_flags & RXRPC_SKB_TX_BUFFER)
  18#define select_skb_count(skb) (is_tx_skb(skb) ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
  19
  20/*
  21 * Note the allocation or reception of a socket buffer.
  22 */
  23void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  24{
  25        const void *here = __builtin_return_address(0);
  26        int n = atomic_inc_return(select_skb_count(skb));
  27        trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
  28                        rxrpc_skb(skb)->rx_flags, here);
  29}
  30
  31/*
  32 * Note the re-emergence of a socket buffer from a queue or buffer.
  33 */
  34void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  35{
  36        const void *here = __builtin_return_address(0);
  37        if (skb) {
  38                int n = atomic_read(select_skb_count(skb));
  39                trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
  40                                rxrpc_skb(skb)->rx_flags, here);
  41        }
  42}
  43
  44/*
  45 * Note the addition of a ref on a socket buffer.
  46 */
  47void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  48{
  49        const void *here = __builtin_return_address(0);
  50        int n = atomic_inc_return(select_skb_count(skb));
  51        trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
  52                        rxrpc_skb(skb)->rx_flags, here);
  53        skb_get(skb);
  54}
  55
  56/*
  57 * Note the dropping of a ref on a socket buffer by the core.
  58 */
  59void rxrpc_eaten_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  60{
  61        const void *here = __builtin_return_address(0);
  62        int n = atomic_inc_return(&rxrpc_n_rx_skbs);
  63        trace_rxrpc_skb(skb, op, 0, n, 0, here);
  64}
  65
  66/*
  67 * Note the destruction of a socket buffer.
  68 */
  69void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
  70{
  71        const void *here = __builtin_return_address(0);
  72        if (skb) {
  73                int n;
  74                CHECK_SLAB_OKAY(&skb->users);
  75                n = atomic_dec_return(select_skb_count(skb));
  76                trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
  77                                rxrpc_skb(skb)->rx_flags, here);
  78                kfree_skb(skb);
  79        }
  80}
  81
  82/*
  83 * Clear a queue of socket buffers.
  84 */
  85void rxrpc_purge_queue(struct sk_buff_head *list)
  86{
  87        const void *here = __builtin_return_address(0);
  88        struct sk_buff *skb;
  89        while ((skb = skb_dequeue((list))) != NULL) {
  90                int n = atomic_dec_return(select_skb_count(skb));
  91                trace_rxrpc_skb(skb, rxrpc_skb_purged,
  92                                refcount_read(&skb->users), n,
  93                                rxrpc_skb(skb)->rx_flags, here);
  94                kfree_skb(skb);
  95        }
  96}
  97