netfilter: nft_ct: labels get support

This also adds NF_CT_LABELS_MAX_SIZE so it can be re-used
as BUILD_BUG_ON in nft_ct.

At this time, nft doesn't yet support writing to the label area;
when this changes the label->words handling needs to be moved
out of xt_connlabel.c into nf_conntrack_labels.c.

Also removes a useless run-time check: words cannot grow beyond
4 (32 bit) or 2 (64bit) since xt_connlabel enforces a maximum of
128 labels.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2014-02-18 15:25:32 +01:00 committed by Pablo Neira Ayuso
parent 2ba436fc02
commit d2bf2f34cc
4 changed files with 30 additions and 4 deletions

View file

@ -7,6 +7,8 @@
#include <uapi/linux/netfilter/xt_connlabel.h>
#define NF_CT_LABELS_MAX_SIZE ((XT_CONNLABEL_MAXBIT + 1) / BITS_PER_BYTE)
struct nf_conn_labels {
u8 words;
unsigned long bits[];
@ -29,7 +31,7 @@ static inline struct nf_conn_labels *nf_ct_labels_ext_add(struct nf_conn *ct)
u8 words;
words = ACCESS_ONCE(net->ct.label_words);
if (words == 0 || WARN_ON_ONCE(words > 8))
if (words == 0)
return NULL;
cl_ext = nf_ct_ext_add_length(ct, NF_CT_EXT_LABELS,

View file

@ -601,6 +601,7 @@ enum nft_ct_keys {
NFT_CT_PROTOCOL,
NFT_CT_PROTO_SRC,
NFT_CT_PROTO_DST,
NFT_CT_LABELS,
};
/**

View file

@ -966,7 +966,6 @@ ctnetlink_parse_help(const struct nlattr *attr, char **helper_name,
return 0;
}
#define __CTA_LABELS_MAX_LENGTH ((XT_CONNLABEL_MAXBIT + 1) / BITS_PER_BYTE)
static const struct nla_policy ct_nla_policy[CTA_MAX+1] = {
[CTA_TUPLE_ORIG] = { .type = NLA_NESTED },
[CTA_TUPLE_REPLY] = { .type = NLA_NESTED },
@ -984,9 +983,9 @@ static const struct nla_policy ct_nla_policy[CTA_MAX+1] = {
[CTA_ZONE] = { .type = NLA_U16 },
[CTA_MARK_MASK] = { .type = NLA_U32 },
[CTA_LABELS] = { .type = NLA_BINARY,
.len = __CTA_LABELS_MAX_LENGTH },
.len = NF_CT_LABELS_MAX_SIZE },
[CTA_LABELS_MASK] = { .type = NLA_BINARY,
.len = __CTA_LABELS_MAX_LENGTH },
.len = NF_CT_LABELS_MAX_SIZE },
};
static int

View file

@ -19,6 +19,7 @@
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_labels.h>
struct nft_ct {
enum nft_ct_keys key:8;
@ -97,6 +98,26 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
goto err;
strncpy((char *)dest->data, helper->name, sizeof(dest->data));
return;
#ifdef CONFIG_NF_CONNTRACK_LABELS
case NFT_CT_LABELS: {
struct nf_conn_labels *labels = nf_ct_labels_find(ct);
unsigned int size;
if (!labels) {
memset(dest->data, 0, sizeof(dest->data));
return;
}
BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE > sizeof(dest->data));
size = labels->words * sizeof(long);
memcpy(dest->data, labels->bits, size);
if (size < sizeof(dest->data))
memset(((char *) dest->data) + size, 0,
sizeof(dest->data) - size);
return;
}
#endif
}
tuple = &ct->tuplehash[priv->dir].tuple;
@ -220,6 +241,9 @@ static int nft_ct_init_validate_get(const struct nft_expr *expr,
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
case NFT_CT_SECMARK:
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
case NFT_CT_LABELS:
#endif
case NFT_CT_EXPIRATION:
case NFT_CT_HELPER: