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
replace_u32(u32 * address,u32 mask,u32 new)14 static int replace_u32(u32 *address, u32 mask, u32 new)
15 {
16 u32 old, tmp;
17
18 do {
19 old = *address;
20 tmp = (old & mask) ^ new;
21 if (old == tmp)
22 return 0;
23 } while (cmpxchg(address, old, tmp) != old);
24
25 return 1;
26 }
27
nf_connlabels_replace(struct nf_conn * ct,const u32 * data,const u32 * mask,unsigned int words32)28 int nf_connlabels_replace(struct nf_conn *ct,
29 const u32 *data,
30 const u32 *mask, unsigned int words32)
31 {
32 struct nf_conn_labels *labels;
33 unsigned int size, i;
34 int changed = 0;
35 u32 *dst;
36
37 labels = nf_ct_labels_find(ct);
38 if (!labels)
39 return -ENOSPC;
40
41 size = sizeof(labels->bits);
42 if (size < (words32 * sizeof(u32)))
43 words32 = size / sizeof(u32);
44
45 dst = (u32 *) labels->bits;
46 for (i = 0; i < words32; i++)
47 changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
48
49 size /= sizeof(u32);
50 for (i = words32; i < size; i++) /* pad */
51 replace_u32(&dst[i], 0, 0);
52
53 if (changed)
54 nf_conntrack_event_cache(IPCT_LABEL, ct);
55 return 0;
56 }
57 EXPORT_SYMBOL_GPL(nf_connlabels_replace);
58
nf_connlabels_get(struct net * net,unsigned int bits)59 int nf_connlabels_get(struct net *net, unsigned int bits)
60 {
61 int v;
62
63 if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long))
64 return -ERANGE;
65
66 BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
67
68 v = atomic_inc_return_relaxed(&net->ct.labels_used);
69 WARN_ON_ONCE(v <= 0);
70
71 return 0;
72 }
73 EXPORT_SYMBOL_GPL(nf_connlabels_get);
74
nf_connlabels_put(struct net * net)75 void nf_connlabels_put(struct net *net)
76 {
77 int v = atomic_dec_return_relaxed(&net->ct.labels_used);
78
79 WARN_ON_ONCE(v < 0);
80 }
81 EXPORT_SYMBOL_GPL(nf_connlabels_put);
82