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/ctype.h>
12 #include <linux/export.h>
13 #include <linux/jhash.h>
14 #include <linux/spinlock.h>
15 #include <linux/types.h>
16 #include <linux/slab.h>
17
18 #include <net/netfilter/nf_conntrack_ecache.h>
19 #include <net/netfilter/nf_conntrack_labels.h>
20
label_bits(const struct nf_conn_labels * l)21 static unsigned int label_bits(const struct nf_conn_labels *l)
22 {
23 unsigned int longs = l->words;
24 return longs * BITS_PER_LONG;
25 }
26
nf_connlabel_match(const struct nf_conn * ct,u16 bit)27 bool nf_connlabel_match(const struct nf_conn *ct, u16 bit)
28 {
29 struct nf_conn_labels *labels = nf_ct_labels_find(ct);
30
31 if (!labels)
32 return false;
33
34 return bit < label_bits(labels) && test_bit(bit, labels->bits);
35 }
36 EXPORT_SYMBOL_GPL(nf_connlabel_match);
37
nf_connlabel_set(struct nf_conn * ct,u16 bit)38 int nf_connlabel_set(struct nf_conn *ct, u16 bit)
39 {
40 struct nf_conn_labels *labels = nf_ct_labels_find(ct);
41
42 if (!labels || bit >= label_bits(labels))
43 return -ENOSPC;
44
45 if (test_bit(bit, labels->bits))
46 return 0;
47
48 if (!test_and_set_bit(bit, labels->bits))
49 nf_conntrack_event_cache(IPCT_LABEL, ct);
50
51 return 0;
52 }
53 EXPORT_SYMBOL_GPL(nf_connlabel_set);
54
55 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
replace_u32(u32 * address,u32 mask,u32 new)56 static void replace_u32(u32 *address, u32 mask, u32 new)
57 {
58 u32 old, tmp;
59
60 do {
61 old = *address;
62 tmp = (old & mask) ^ new;
63 } while (cmpxchg(address, old, tmp) != old);
64 }
65
nf_connlabels_replace(struct nf_conn * ct,const u32 * data,const u32 * mask,unsigned int words32)66 int nf_connlabels_replace(struct nf_conn *ct,
67 const u32 *data,
68 const u32 *mask, unsigned int words32)
69 {
70 struct nf_conn_labels *labels;
71 unsigned int size, i;
72 u32 *dst;
73
74 labels = nf_ct_labels_find(ct);
75 if (!labels)
76 return -ENOSPC;
77
78 size = labels->words * sizeof(long);
79 if (size < (words32 * sizeof(u32)))
80 words32 = size / sizeof(u32);
81
82 dst = (u32 *) labels->bits;
83 if (words32) {
84 for (i = 0; i < words32; i++)
85 replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
86 }
87
88 size /= sizeof(u32);
89 for (i = words32; i < size; i++) /* pad */
90 replace_u32(&dst[i], 0, 0);
91
92 nf_conntrack_event_cache(IPCT_LABEL, ct);
93 return 0;
94 }
95 EXPORT_SYMBOL_GPL(nf_connlabels_replace);
96 #endif
97
98 static struct nf_ct_ext_type labels_extend __read_mostly = {
99 .len = sizeof(struct nf_conn_labels),
100 .align = __alignof__(struct nf_conn_labels),
101 .id = NF_CT_EXT_LABELS,
102 };
103
nf_conntrack_labels_init(void)104 int nf_conntrack_labels_init(void)
105 {
106 return nf_ct_extend_register(&labels_extend);
107 }
108
nf_conntrack_labels_fini(void)109 void nf_conntrack_labels_fini(void)
110 {
111 nf_ct_extend_unregister(&labels_extend);
112 }
113