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
17static 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
23bool 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}
32EXPORT_SYMBOL_GPL(nf_connlabel_match);
33
34int 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}
49EXPORT_SYMBOL_GPL(nf_connlabel_set);
50
51#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
52static 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
62int 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}
91EXPORT_SYMBOL_GPL(nf_connlabels_replace);
92#endif
93
94static 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
100int nf_conntrack_labels_init(void)
101{
102	return nf_ct_extend_register(&labels_extend);
103}
104
105void nf_conntrack_labels_fini(void)
106{
107	nf_ct_extend_unregister(&labels_extend);
108}
109