1 /*
2 * test/set flag bits stored in conntrack extension area.
3 *
4 * (C) 2013 Astaro GmbH & Co KG
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/export.h>
12 #include <linux/types.h>
13
14 #include <net/netfilter/nf_conntrack_ecache.h>
15 #include <net/netfilter/nf_conntrack_labels.h>
16
label_bits(const struct nf_conn_labels * l)17 static unsigned int label_bits(const struct nf_conn_labels *l)
18 {
19 unsigned int longs = l->words;
20 return longs * BITS_PER_LONG;
21 }
22
nf_connlabel_match(const struct nf_conn * ct,u16 bit)23 bool nf_connlabel_match(const struct nf_conn *ct, u16 bit)
24 {
25 struct nf_conn_labels *labels = nf_ct_labels_find(ct);
26
27 if (!labels)
28 return false;
29
30 return bit < label_bits(labels) && test_bit(bit, labels->bits);
31 }
32 EXPORT_SYMBOL_GPL(nf_connlabel_match);
33
nf_connlabel_set(struct nf_conn * ct,u16 bit)34 int nf_connlabel_set(struct nf_conn *ct, u16 bit)
35 {
36 struct nf_conn_labels *labels = nf_ct_labels_find(ct);
37
38 if (!labels || bit >= label_bits(labels))
39 return -ENOSPC;
40
41 if (test_bit(bit, labels->bits))
42 return 0;
43
44 if (!test_and_set_bit(bit, labels->bits))
45 nf_conntrack_event_cache(IPCT_LABEL, ct);
46
47 return 0;
48 }
49 EXPORT_SYMBOL_GPL(nf_connlabel_set);
50
51 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
replace_u32(u32 * address,u32 mask,u32 new)52 static void replace_u32(u32 *address, u32 mask, u32 new)
53 {
54 u32 old, tmp;
55
56 do {
57 old = *address;
58 tmp = (old & mask) ^ new;
59 } while (cmpxchg(address, old, tmp) != old);
60 }
61
nf_connlabels_replace(struct nf_conn * ct,const u32 * data,const u32 * mask,unsigned int words32)62 int nf_connlabels_replace(struct nf_conn *ct,
63 const u32 *data,
64 const u32 *mask, unsigned int words32)
65 {
66 struct nf_conn_labels *labels;
67 unsigned int size, i;
68 u32 *dst;
69
70 labels = nf_ct_labels_find(ct);
71 if (!labels)
72 return -ENOSPC;
73
74 size = labels->words * sizeof(long);
75 if (size < (words32 * sizeof(u32)))
76 words32 = size / sizeof(u32);
77
78 dst = (u32 *) labels->bits;
79 if (words32) {
80 for (i = 0; i < words32; i++)
81 replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
82 }
83
84 size /= sizeof(u32);
85 for (i = words32; i < size; i++) /* pad */
86 replace_u32(&dst[i], 0, 0);
87
88 nf_conntrack_event_cache(IPCT_LABEL, ct);
89 return 0;
90 }
91 EXPORT_SYMBOL_GPL(nf_connlabels_replace);
92 #endif
93
94 static struct nf_ct_ext_type labels_extend __read_mostly = {
95 .len = sizeof(struct nf_conn_labels),
96 .align = __alignof__(struct nf_conn_labels),
97 .id = NF_CT_EXT_LABELS,
98 };
99
nf_conntrack_labels_init(void)100 int nf_conntrack_labels_init(void)
101 {
102 return nf_ct_extend_register(&labels_extend);
103 }
104
nf_conntrack_labels_fini(void)105 void nf_conntrack_labels_fini(void)
106 {
107 nf_ct_extend_unregister(&labels_extend);
108 }
109