diff options
author | Florian Westphal <fw@strlen.de> | 2013-01-11 10:30:46 +0400 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-01-18 03:28:17 +0400 |
commit | 9b21f6a90924dfe8e5e686c314ddb441fb06501e (patch) | |
tree | 015decd07bc0bc7dfd53e8e2a417a138964a2b20 /net/netfilter/nf_conntrack_netlink.c | |
parent | 0ceabd83875b72a29f33db4ab703d6ba40ea4c58 (diff) | |
download | linux-9b21f6a90924dfe8e5e686c314ddb441fb06501e.tar.xz |
netfilter: ctnetlink: allow userspace to modify labels
Add the ability to set/clear labels assigned to a conntrack
via ctnetlink.
To allow userspace to only alter specific bits, Pablo suggested to add
a new CTA_LABELS_MASK attribute:
The new set of active labels is then determined via
active = (active & ~mask) ^ changeset
i.e., the mask selects those bits in the existing set that should be
changed.
This follows the same method already used by MARK and CONNMARK targets.
Omitting CTA_LABELS_MASK is the same as setting all bits in CTA_LABELS_MASK
to 1: The existing set is replaced by the one from userspace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_conntrack_netlink.c')
-rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 5f5386382f13..2334cc5d2b16 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -961,6 +961,7 @@ 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 }, @@ -977,6 +978,10 @@ static const struct nla_policy ct_nla_policy[CTA_MAX+1] = { [CTA_NAT_SEQ_ADJ_REPLY] = { .type = NLA_NESTED }, [CTA_ZONE] = { .type = NLA_U16 }, [CTA_MARK_MASK] = { .type = NLA_U32 }, + [CTA_LABELS] = { .type = NLA_BINARY, + .len = __CTA_LABELS_MAX_LENGTH }, + [CTA_LABELS_MASK] = { .type = NLA_BINARY, + .len = __CTA_LABELS_MAX_LENGTH }, }; static int @@ -1505,6 +1510,31 @@ ctnetlink_change_nat_seq_adj(struct nf_conn *ct, #endif static int +ctnetlink_attach_labels(struct nf_conn *ct, const struct nlattr * const cda[]) +{ +#ifdef CONFIG_NF_CONNTRACK_LABELS + size_t len = nla_len(cda[CTA_LABELS]); + const void *mask = cda[CTA_LABELS_MASK]; + + if (len & (sizeof(u32)-1)) /* must be multiple of u32 */ + return -EINVAL; + + if (mask) { + if (nla_len(cda[CTA_LABELS_MASK]) == 0 || + nla_len(cda[CTA_LABELS_MASK]) != len) + return -EINVAL; + mask = nla_data(cda[CTA_LABELS_MASK]); + } + + len /= sizeof(u32); + + return nf_connlabels_replace(ct, nla_data(cda[CTA_LABELS]), mask, len); +#else + return -EOPNOTSUPP; +#endif +} + +static int ctnetlink_change_conntrack(struct nf_conn *ct, const struct nlattr * const cda[]) { @@ -1550,6 +1580,11 @@ ctnetlink_change_conntrack(struct nf_conn *ct, return err; } #endif + if (cda[CTA_LABELS]) { + err = ctnetlink_attach_labels(ct, cda); + if (err < 0) + return err; + } return 0; } @@ -1758,6 +1793,10 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb, else events = IPCT_NEW; + if (cda[CTA_LABELS] && + ctnetlink_attach_labels(ct, cda) == 0) + events |= (1 << IPCT_LABEL); + nf_conntrack_eventmask_report((1 << IPCT_REPLY) | (1 << IPCT_ASSURED) | (1 << IPCT_HELPER) | @@ -2055,6 +2094,11 @@ ctnetlink_nfqueue_parse_ct(const struct nlattr *cda[], struct nf_conn *ct) if (err < 0) return err; } + if (cda[CTA_LABELS]) { + err = ctnetlink_attach_labels(ct, cda); + if (err < 0) + return err; + } #if defined(CONFIG_NF_CONNTRACK_MARK) if (cda[CTA_MARK]) ct->mark = ntohl(nla_get_be32(cda[CTA_MARK])); |