From patchwork Fri Jan 11 16:30:46 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 211377 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id DF5F92C0324 for ; Sat, 12 Jan 2013 03:29:07 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754373Ab3AKQ3G (ORCPT ); Fri, 11 Jan 2013 11:29:06 -0500 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:50601 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753818Ab3AKQ3F (ORCPT ); Fri, 11 Jan 2013 11:29:05 -0500 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.72) (envelope-from ) id 1TthTc-0005Lj-3N; Fri, 11 Jan 2013 17:29:04 +0100 From: Florian Westphal To: netfilter-devel Cc: Florian Westphal Subject: [PATCH 3/3] netfilter: ctnetlink: allow userspace to modify labels Date: Fri, 11 Jan 2013 17:30:46 +0100 Message-Id: <1357921846-29650-4-git-send-email-fw@strlen.de> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1357921846-29650-1-git-send-email-fw@strlen.de> References: <1357921846-29650-1-git-send-email-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org 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 --- include/net/netfilter/nf_conntrack_labels.h | 3 + include/uapi/linux/netfilter/nfnetlink_conntrack.h | 1 + net/netfilter/nf_conntrack_labels.c | 43 +++++++++++++++++++ net/netfilter/nf_conntrack_netlink.c | 44 ++++++++++++++++++++ 4 files changed, 91 insertions(+), 0 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_labels.h b/include/net/netfilter/nf_conntrack_labels.h index b94fe31..a3ce5d0 100644 --- a/include/net/netfilter/nf_conntrack_labels.h +++ b/include/net/netfilter/nf_conntrack_labels.h @@ -46,6 +46,9 @@ static inline struct nf_conn_labels *nf_ct_labels_ext_add(struct nf_conn *ct) bool nf_connlabel_match(const struct nf_conn *ct, u16 bit); int nf_connlabel_set(struct nf_conn *ct, u16 bit); +int nf_connlabels_replace(struct nf_conn *ct, + const u32 *data, const u32 *mask, unsigned int words); + #ifdef CONFIG_NF_CONNTRACK_LABELS int nf_conntrack_labels_init(struct net *net); void nf_conntrack_labels_fini(struct net *net); diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h index 9e71e0c..08fabc6 100644 --- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h +++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h @@ -50,6 +50,7 @@ enum ctattr_type { CTA_TIMESTAMP, CTA_MARK_MASK, CTA_LABELS, + CTA_LABELS_MASK, __CTA_MAX }; #define CTA_MAX (__CTA_MAX - 1) diff --git a/net/netfilter/nf_conntrack_labels.c b/net/netfilter/nf_conntrack_labels.c index 2a82236..c99bd11 100644 --- a/net/netfilter/nf_conntrack_labels.c +++ b/net/netfilter/nf_conntrack_labels.c @@ -52,6 +52,49 @@ int nf_connlabel_set(struct nf_conn *ct, u16 bit) } EXPORT_SYMBOL_GPL(nf_connlabel_set); +#if IS_ENABLED(CONFIG_NF_CT_NETLINK) +static void replace_u32(u32 *address, u32 mask, u32 new) +{ + u32 old, tmp; + + do { + old = *address; + tmp = (old & mask) ^ new; + } while (cmpxchg(address, old, tmp) != old); +} + +int nf_connlabels_replace(struct nf_conn *ct, + const u32 *data, + const u32 *mask, unsigned int words32) +{ + struct nf_conn_labels *labels; + unsigned int size, i; + u32 *dst; + + labels = nf_ct_labels_find(ct); + if (!labels) + return -ENOSPC; + + size = labels->words * sizeof(long); + if (size < (words32 * sizeof(u32))) + words32 = size / sizeof(u32); + + dst = (u32 *) labels->bits; + if (words32) { + for (i = 0; i < words32; i++) + replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]); + } + + size /= sizeof(u32); + for (i = words32; i < size; i++) /* pad */ + replace_u32(&dst[i], 0, 0); + + nf_conntrack_event_cache(IPCT_LABEL, ct); + return 0; +} +EXPORT_SYMBOL_GPL(nf_connlabels_replace); +#endif + static struct nf_ct_ext_type labels_extend __read_mostly = { .len = sizeof(struct nf_conn_labels), .align = __alignof__(struct nf_conn_labels), diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 005ab7e..c957fe2 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]));