net/rxrpc/skbuff.c

   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  */
  26 void 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  */
  36 void 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  */
  48 void 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  */
  59 void 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  */
  74 void 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  */
  89 void 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 }