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  */
  23 void 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  */
  34 void 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  */
  47 void 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  */
  59 void 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  */
  69 void 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  */
  85 void 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 }