adff6c6560
nf_connlabel_set() takes the bit number that we would like to set. nf_connlabels_get() however took the number of bits that we want to support. So e.g. nf_connlabels_get(32) support bits 0 to 31, but not 32. This changes nf_connlabels_get() to take the highest bit that we want to set. Callers then don't have to cope with a potential integer wrap when using nf_connlabels_get(bit + 1) anymore. Current callers are fine, this change is only to make folloup nft ct label set support simpler. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
127 lines
2.8 KiB
C
127 lines
2.8 KiB
C
/*
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* test/set flag bits stored in conntrack extension area.
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*
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* (C) 2013 Astaro GmbH & Co KG
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/export.h>
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#include <linux/types.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_conntrack_labels.h>
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static spinlock_t nf_connlabels_lock;
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int nf_connlabel_set(struct nf_conn *ct, u16 bit)
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{
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struct nf_conn_labels *labels = nf_ct_labels_find(ct);
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if (!labels || BIT_WORD(bit) >= labels->words)
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return -ENOSPC;
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if (test_bit(bit, labels->bits))
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return 0;
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if (!test_and_set_bit(bit, labels->bits))
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nf_conntrack_event_cache(IPCT_LABEL, ct);
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return 0;
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}
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EXPORT_SYMBOL_GPL(nf_connlabel_set);
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static int replace_u32(u32 *address, u32 mask, u32 new)
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{
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u32 old, tmp;
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do {
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old = *address;
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tmp = (old & mask) ^ new;
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if (old == tmp)
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return 0;
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} while (cmpxchg(address, old, tmp) != old);
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return 1;
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}
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int nf_connlabels_replace(struct nf_conn *ct,
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const u32 *data,
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const u32 *mask, unsigned int words32)
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{
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struct nf_conn_labels *labels;
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unsigned int size, i;
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int changed = 0;
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u32 *dst;
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labels = nf_ct_labels_find(ct);
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if (!labels)
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return -ENOSPC;
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size = labels->words * sizeof(long);
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if (size < (words32 * sizeof(u32)))
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words32 = size / sizeof(u32);
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dst = (u32 *) labels->bits;
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for (i = 0; i < words32; i++)
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changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
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size /= sizeof(u32);
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for (i = words32; i < size; i++) /* pad */
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replace_u32(&dst[i], 0, 0);
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if (changed)
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nf_conntrack_event_cache(IPCT_LABEL, ct);
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return 0;
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}
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EXPORT_SYMBOL_GPL(nf_connlabels_replace);
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int nf_connlabels_get(struct net *net, unsigned int bits)
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{
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size_t words;
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words = BIT_WORD(bits) + 1;
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if (words > NF_CT_LABELS_MAX_SIZE / sizeof(long))
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return -ERANGE;
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spin_lock(&nf_connlabels_lock);
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net->ct.labels_used++;
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if (words > net->ct.label_words)
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net->ct.label_words = words;
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spin_unlock(&nf_connlabels_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(nf_connlabels_get);
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void nf_connlabels_put(struct net *net)
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{
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spin_lock(&nf_connlabels_lock);
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net->ct.labels_used--;
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if (net->ct.labels_used == 0)
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net->ct.label_words = 0;
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spin_unlock(&nf_connlabels_lock);
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}
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EXPORT_SYMBOL_GPL(nf_connlabels_put);
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static struct nf_ct_ext_type labels_extend __read_mostly = {
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.len = sizeof(struct nf_conn_labels),
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.align = __alignof__(struct nf_conn_labels),
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.id = NF_CT_EXT_LABELS,
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};
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int nf_conntrack_labels_init(void)
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{
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BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
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spin_lock_init(&nf_connlabels_lock);
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return nf_ct_extend_register(&labels_extend);
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}
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void nf_conntrack_labels_fini(void)
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{
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nf_ct_extend_unregister(&labels_extend);
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}
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