From d2bf2f34cc1a8304a5dab0d42e7a2ae58ede94cd Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 18 Feb 2014 15:25:32 +0100 Subject: [PATCH] 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 Acked-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_labels.h | 4 +++- include/uapi/linux/netfilter/nf_tables.h | 1 + net/netfilter/nf_conntrack_netlink.c | 5 ++--- net/netfilter/nft_ct.c | 24 ++++++++++++++++++++++++ 4 files changed, 30 insertions(+), 4 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_labels.h b/include/net/netfilter/nf_conntrack_labels.h index c985695283b3..dec6336bf850 100644 --- a/include/net/netfilter/nf_conntrack_labels.h +++ b/include/net/netfilter/nf_conntrack_labels.h @@ -7,6 +7,8 @@ #include +#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, diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 83c985a6170b..c84c452c62a7 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -601,6 +601,7 @@ enum nft_ct_keys { NFT_CT_PROTOCOL, NFT_CT_PROTO_SRC, NFT_CT_PROTO_DST, + NFT_CT_LABELS, }; /** diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index bb322d0beb48..47e9369997ef 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -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 diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c index 46e275403838..e59b08f9ccbd 100644 --- a/net/netfilter/nft_ct.c +++ b/net/netfilter/nft_ct.c @@ -19,6 +19,7 @@ #include #include #include +#include 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; @@ -221,6 +242,9 @@ static int nft_ct_init_validate_get(const struct nft_expr *expr, #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: if (tb[NFTA_CT_DIRECTION] != NULL) -- 2.11.0