Eric Lee / smarc-fsl-linux-kernel

Blame view

net/netfilter/nf_conntrack_labels.c 2.25 KB
edit raw normal view history
81f7e3824   Eric Lee   Initial Release, ... 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
 
  /*
   * test/set flag bits stored in conntrack extension area.
   *
   * (C) 2013 Astaro GmbH & Co KG
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/export.h>
  #include <linux/types.h>
  
  #include <net/netfilter/nf_conntrack_ecache.h>
  #include <net/netfilter/nf_conntrack_labels.h>
  
  static spinlock_t nf_connlabels_lock;
  
  static int replace_u32(u32 *address, u32 mask, u32 new)
  {
  	u32 old, tmp;
  
  	do {
  		old = *address;
  		tmp = (old & mask) ^ new;
  		if (old == tmp)
  			return 0;
  	} while (cmpxchg(address, old, tmp) != old);
  
  	return 1;
  }
  
  int nf_connlabels_replace(struct nf_conn *ct,
  			  const u32 *data,
  			  const u32 *mask, unsigned int words32)
  {
  	struct nf_conn_labels *labels;
  	unsigned int size, i;
  	int changed = 0;
  	u32 *dst;
  
  	labels = nf_ct_labels_find(ct);
  	if (!labels)
  		return -ENOSPC;
  
  	size = sizeof(labels->bits);
  	if (size < (words32 * sizeof(u32)))
  		words32 = size / sizeof(u32);
  
  	dst = (u32 *) labels->bits;
  	for (i = 0; i < words32; i++)
  		changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
  
  	size /= sizeof(u32);
  	for (i = words32; i < size; i++) /* pad */
  		replace_u32(&dst[i], 0, 0);
  
  	if (changed)
  		nf_conntrack_event_cache(IPCT_LABEL, ct);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(nf_connlabels_replace);
  
  int nf_connlabels_get(struct net *net, unsigned int bits)
  {
  	if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long))
  		return -ERANGE;
  
  	spin_lock(&nf_connlabels_lock);
  	net->ct.labels_used++;
  	spin_unlock(&nf_connlabels_lock);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(nf_connlabels_get);
  
  void nf_connlabels_put(struct net *net)
  {
  	spin_lock(&nf_connlabels_lock);
  	net->ct.labels_used--;
  	spin_unlock(&nf_connlabels_lock);
  }
  EXPORT_SYMBOL_GPL(nf_connlabels_put);
  
  static const struct nf_ct_ext_type labels_extend = {
  	.len    = sizeof(struct nf_conn_labels),
  	.align  = __alignof__(struct nf_conn_labels),
  	.id     = NF_CT_EXT_LABELS,
  };
  
  int nf_conntrack_labels_init(void)
  {
  	BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
  
  	spin_lock_init(&nf_connlabels_lock);
  	return nf_ct_extend_register(&labels_extend);
  }
  
  void nf_conntrack_labels_fini(void)
  {
  	nf_ct_extend_unregister(&labels_extend);
  }