1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * test/set flag bits stored in conntrack extension area.
4 *
5 * (C) 2013 Astaro GmbH & Co KG
6 */
7
8 #include <linux/export.h>
9 #include <linux/types.h>
10
11 #include <net/netfilter/nf_conntrack_ecache.h>
12 #include <net/netfilter/nf_conntrack_labels.h>
13
14 static DEFINE_SPINLOCK(nf_connlabels_lock);
15
replace_u32(u32 * address,u32 mask,u32 new)16 static int replace_u32(u32 *address, u32 mask, u32 new)
17 {
18 u32 old, tmp;
19
20 do {
21 old = *address;
22 tmp = (old & mask) ^ new;
23 if (old == tmp)
24 return 0;
25 } while (cmpxchg(address, old, tmp) != old);
26
27 return 1;
28 }
29
nf_connlabels_replace(struct nf_conn * ct,const u32 * data,const u32 * mask,unsigned int words32)30 int nf_connlabels_replace(struct nf_conn *ct,
31 const u32 *data,
32 const u32 *mask, unsigned int words32)
33 {
34 struct nf_conn_labels *labels;
35 unsigned int size, i;
36 int changed = 0;
37 u32 *dst;
38
39 labels = nf_ct_labels_find(ct);
40 if (!labels)
41 return -ENOSPC;
42
43 size = sizeof(labels->bits);
44 if (size < (words32 * sizeof(u32)))
45 words32 = size / sizeof(u32);
46
47 dst = (u32 *) labels->bits;
48 for (i = 0; i < words32; i++)
49 changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
50
51 size /= sizeof(u32);
52 for (i = words32; i < size; i++) /* pad */
53 replace_u32(&dst[i], 0, 0);
54
55 if (changed)
56 nf_conntrack_event_cache(IPCT_LABEL, ct);
57 return 0;
58 }
59 EXPORT_SYMBOL_GPL(nf_connlabels_replace);
60
nf_connlabels_get(struct net * net,unsigned int bits)61 int nf_connlabels_get(struct net *net, unsigned int bits)
62 {
63 if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long))
64 return -ERANGE;
65
66 spin_lock(&nf_connlabels_lock);
67 net->ct.labels_used++;
68 spin_unlock(&nf_connlabels_lock);
69
70 return 0;
71 }
72 EXPORT_SYMBOL_GPL(nf_connlabels_get);
73
nf_connlabels_put(struct net * net)74 void nf_connlabels_put(struct net *net)
75 {
76 spin_lock(&nf_connlabels_lock);
77 net->ct.labels_used--;
78 spin_unlock(&nf_connlabels_lock);
79 }
80 EXPORT_SYMBOL_GPL(nf_connlabels_put);
81
82 static const struct nf_ct_ext_type labels_extend = {
83 .len = sizeof(struct nf_conn_labels),
84 .align = __alignof__(struct nf_conn_labels),
85 .id = NF_CT_EXT_LABELS,
86 };
87
nf_conntrack_labels_init(void)88 int nf_conntrack_labels_init(void)
89 {
90 BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
91
92 return nf_ct_extend_register(&labels_extend);
93 }
94
nf_conntrack_labels_fini(void)95 void nf_conntrack_labels_fini(void)
96 {
97 nf_ct_extend_unregister(&labels_extend);
98 }
99