From b7bd1809e0784435791657502bc0d8280ad6f7ea Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 30 Sep 2015 22:53:44 +0100 Subject: [PATCH] netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c The original intention was to avoid dependencies between nfnetlink_queue and conntrack without ifdef pollution. However, we can achieve this by moving the conntrack dependent code into ctnetlink and keep some glue code to access the nfq_ct indirection from nfqueue. After this patch, the nfq_ct indirection is always compiled in the netfilter core to avoid polluting nfqueue with ifdefs. Thus, if nf_conntrack is not compiled this results in only 8-bytes of memory waste in x86_64. This patch also adds ctnetlink_nfqueue_seqadj() to avoid that the nf_conn structure layout if exposed to nf_queue, which creates another dependency with nf_conntrack at compilation time. Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter.h | 12 ++- include/net/netfilter/nfnetlink_queue.h | 51 ----------- net/netfilter/Makefile | 1 - net/netfilter/core.c | 9 +- net/netfilter/nf_conntrack_netlink.c | 52 ++++++++++- net/netfilter/nfnetlink_queue_core.c | 52 ++++++++--- net/netfilter/nfnetlink_queue_ct.c | 113 ------------------------ 7 files changed, 103 insertions(+), 187 deletions(-) delete mode 100644 include/net/netfilter/nfnetlink_queue.h delete mode 100644 net/netfilter/nfnetlink_queue_ct.c diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 165ab2d14734..3e5e8f2b65f6 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -369,14 +369,21 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family) extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu; void nf_ct_attach(struct sk_buff *, const struct sk_buff *); extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu; +#else +static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} +#endif struct nf_conn; enum ip_conntrack_info; struct nlattr; struct nfq_ct_hook { + struct nf_conn *(*get_ct)(struct sk_buff *skb, + enum ip_conntrack_info *ctinfo); size_t (*build_size)(const struct nf_conn *ct); - int (*build)(struct sk_buff *skb, struct nf_conn *ct); + int (*build)(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + u_int16_t ct_attr, u_int16_t ct_info_attr); int (*parse)(const struct nlattr *attr, struct nf_conn *ct); int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct, u32 portid, u32 report); @@ -384,9 +391,6 @@ struct nfq_ct_hook { enum ip_conntrack_info ctinfo, s32 off); }; extern struct nfq_ct_hook __rcu *nfq_ct_hook; -#else -static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} -#endif /** * nf_skb_duplicated - TEE target has sent a packet diff --git a/include/net/netfilter/nfnetlink_queue.h b/include/net/netfilter/nfnetlink_queue.h deleted file mode 100644 index aff88ba91391..000000000000 --- a/include/net/netfilter/nfnetlink_queue.h +++ /dev/null @@ -1,51 +0,0 @@ -#ifndef _NET_NFNL_QUEUE_H_ -#define _NET_NFNL_QUEUE_H_ - -#include - -struct nf_conn; - -#ifdef CONFIG_NETFILTER_NETLINK_QUEUE_CT -struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size, - enum ip_conntrack_info *ctinfo); -struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb, - const struct nlattr *attr, - enum ip_conntrack_info *ctinfo); -int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo); -void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo, int diff); -int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr, - u32 portid, u32 report); -#else -inline struct nf_conn * -nfqnl_ct_get(struct sk_buff *entskb, size_t *size, enum ip_conntrack_info *ctinfo) -{ - return NULL; -} - -inline struct nf_conn *nfqnl_ct_parse(const struct sk_buff *skb, - const struct nlattr *attr, - enum ip_conntrack_info *ctinfo) -{ - return NULL; -} - -inline int -nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info ctinfo) -{ - return 0; -} - -inline void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo, int diff) -{ -} - -inline int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr, - u32 portid, u32 report) -{ - return 0; -} -#endif /* NF_CONNTRACK */ -#endif diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 70d026d46fe7..4d68e72d59ab 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -11,7 +11,6 @@ obj-$(CONFIG_NETFILTER) = netfilter.o obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o obj-$(CONFIG_NETFILTER_NETLINK_ACCT) += nfnetlink_acct.o nfnetlink_queue-y := nfnetlink_queue_core.o -nfnetlink_queue-$(CONFIG_NETFILTER_NETLINK_QUEUE_CT) += nfnetlink_queue_ct.o obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o obj-$(CONFIG_NETFILTER_NETLINK_LOG) += nfnetlink_log.o diff --git a/net/netfilter/core.c b/net/netfilter/core.c index 2e907335ee81..1412e3684c1c 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -348,6 +348,12 @@ int skb_make_writable(struct sk_buff *skb, unsigned int writable_len) } EXPORT_SYMBOL(skb_make_writable); +/* This needs to be compiled in any case to avoid dependencies between the + * nfnetlink_queue code and nf_conntrack. + */ +struct nfq_ct_hook __rcu *nfq_ct_hook __read_mostly; +EXPORT_SYMBOL_GPL(nfq_ct_hook); + #if IS_ENABLED(CONFIG_NF_CONNTRACK) /* This does not belong here, but locally generated errors need it if connection tracking in use: without this, connection may not be in hash table, and hence @@ -385,9 +391,6 @@ void nf_conntrack_destroy(struct nf_conntrack *nfct) } EXPORT_SYMBOL(nf_conntrack_destroy); -struct nfq_ct_hook __rcu *nfq_ct_hook __read_mostly; -EXPORT_SYMBOL_GPL(nfq_ct_hook); - /* Built-in default zone used e.g. by modules. */ const struct nf_conntrack_zone nf_ct_zone_dflt = { .id = NF_CT_DEFAULT_ZONE_ID, diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 94a66541e0b7..eb67bf8dd174 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -2162,8 +2162,19 @@ ctnetlink_nfqueue_build_size(const struct nf_conn *ct) ; } -static int -ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct) +static struct nf_conn *ctnetlink_nfqueue_get_ct(struct sk_buff *skb, + enum ip_conntrack_info *ctinfo) +{ + struct nf_conn *ct; + + ct = nf_ct_get(skb, ctinfo); + if (ct && nf_ct_is_untracked(ct)) + ct = NULL; + + return ct; +} + +static int __ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct) { const struct nf_conntrack_zone *zone; struct nlattr *nest_parms; @@ -2235,6 +2246,31 @@ nla_put_failure: return -ENOSPC; } +static int +ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + u_int16_t ct_attr, u_int16_t ct_info_attr) +{ + struct nlattr *nest_parms; + + nest_parms = nla_nest_start(skb, ct_attr | NLA_F_NESTED); + if (!nest_parms) + goto nla_put_failure; + + if (__ctnetlink_nfqueue_build(skb, ct) < 0) + goto nla_put_failure; + + nla_nest_end(skb, nest_parms); + + if (nla_put_be32(skb, ct_info_attr, htonl(ctinfo))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -ENOSPC; +} + static int ctnetlink_nfqueue_parse_ct(const struct nlattr *cda[], struct nf_conn *ct) { @@ -2350,12 +2386,22 @@ ctnetlink_nfqueue_attach_expect(const struct nlattr *attr, struct nf_conn *ct, return 0; } +static void ctnetlink_nfqueue_seqadj(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo, int diff) +{ + if (!(ct->status & IPS_NAT_MASK)) + return; + + nf_ct_tcp_seqadj_set(skb, ct, ctinfo, diff); +} + static struct nfq_ct_hook ctnetlink_nfqueue_hook = { + .get_ct = ctnetlink_nfqueue_get_ct, .build_size = ctnetlink_nfqueue_build_size, .build = ctnetlink_nfqueue_build, .parse = ctnetlink_nfqueue_parse, .attach_expect = ctnetlink_nfqueue_attach_expect, - .seq_adjust = nf_ct_tcp_seqadj_set, + .seq_adjust = ctnetlink_nfqueue_seqadj, }; #endif /* CONFIG_NETFILTER_NETLINK_QUEUE_CT */ diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index 41583e30051b..b1f1c747d518 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -28,12 +28,12 @@ #include #include #include +#include #include #include #include #include #include -#include #include @@ -313,6 +313,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, struct net_device *outdev; struct nf_conn *ct = NULL; enum ip_conntrack_info uninitialized_var(ctinfo); + struct nfq_ct_hook *nfq_ct; bool csum_verify; char *secdata = NULL; u32 seclen = 0; @@ -364,8 +365,14 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, break; } - if (queue->flags & NFQA_CFG_F_CONNTRACK) - ct = nfqnl_ct_get(entskb, &size, &ctinfo); + if (queue->flags & NFQA_CFG_F_CONNTRACK) { + nfq_ct = rcu_dereference(nfq_ct_hook); + if (nfq_ct != NULL) { + ct = nfq_ct->get_ct(entskb, &ctinfo); + if (ct != NULL) + size += nfq_ct->build_size(ct); + } + } if (queue->flags & NFQA_CFG_F_UID_GID) { size += (nla_total_size(sizeof(u_int32_t)) /* uid */ @@ -508,7 +515,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) goto nla_put_failure; - if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0) + if (ct && nfq_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) goto nla_put_failure; if (cap_len > data_len && @@ -1001,6 +1008,28 @@ nfqnl_recv_verdict_batch(struct sock *ctnl, struct sk_buff *skb, return 0; } +static struct nf_conn *nfqnl_ct_parse(struct nfq_ct_hook *nfq_ct, + const struct nlmsghdr *nlh, + const struct nlattr * const nfqa[], + struct nf_queue_entry *entry, + enum ip_conntrack_info *ctinfo) +{ + struct nf_conn *ct; + + ct = nfq_ct->get_ct(entry->skb, ctinfo); + if (ct == NULL) + return NULL; + + if (nfq_ct->parse(nfqa[NFQA_CT], ct) < 0) + return NULL; + + if (nfqa[NFQA_EXP]) + nfq_ct->attach_expect(nfqa[NFQA_EXP], ct, + NETLINK_CB(entry->skb).portid, + nlmsg_report(nlh)); + return ct; +} + static int nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, const struct nlmsghdr *nlh, @@ -1014,6 +1043,7 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, unsigned int verdict; struct nf_queue_entry *entry; enum ip_conntrack_info uninitialized_var(ctinfo); + struct nfq_ct_hook *nfq_ct; struct nf_conn *ct = NULL; struct net *net = sock_net(ctnl); @@ -1037,12 +1067,10 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, return -ENOENT; if (nfqa[NFQA_CT]) { - ct = nfqnl_ct_parse(entry->skb, nfqa[NFQA_CT], &ctinfo); - if (ct && nfqa[NFQA_EXP]) { - nfqnl_attach_expect(ct, nfqa[NFQA_EXP], - NETLINK_CB(skb).portid, - nlmsg_report(nlh)); - } + /* rcu lock already held from nfnl->call_rcu. */ + nfq_ct = rcu_dereference(nfq_ct_hook); + if (nfq_ct != NULL) + ct = nfqnl_ct_parse(nfq_ct, nlh, nfqa, entry, &ctinfo); } if (nfqa[NFQA_PAYLOAD]) { @@ -1053,8 +1081,8 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, payload_len, entry, diff) < 0) verdict = NF_DROP; - if (ct) - nfqnl_ct_seq_adjust(entry->skb, ct, ctinfo, diff); + if (ct && diff) + nfq_ct->seq_adjust(entry->skb, ct, ctinfo, diff); } if (nfqa[NFQA_MARK]) diff --git a/net/netfilter/nfnetlink_queue_ct.c b/net/netfilter/nfnetlink_queue_ct.c deleted file mode 100644 index 96cac50e0d12..000000000000 --- a/net/netfilter/nfnetlink_queue_ct.c +++ /dev/null @@ -1,113 +0,0 @@ -/* - * (C) 2012 by Pablo Neira Ayuso - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - */ - -#include -#include -#include -#include -#include -#include - -struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size, - enum ip_conntrack_info *ctinfo) -{ - struct nfq_ct_hook *nfq_ct; - struct nf_conn *ct; - - /* rcu_read_lock()ed by __nf_queue already. */ - nfq_ct = rcu_dereference(nfq_ct_hook); - if (nfq_ct == NULL) - return NULL; - - ct = nf_ct_get(entskb, ctinfo); - if (ct) { - if (!nf_ct_is_untracked(ct)) - *size += nfq_ct->build_size(ct); - else - ct = NULL; - } - return ct; -} - -struct nf_conn * -nfqnl_ct_parse(const struct sk_buff *skb, const struct nlattr *attr, - enum ip_conntrack_info *ctinfo) -{ - struct nfq_ct_hook *nfq_ct; - struct nf_conn *ct; - - /* rcu_read_lock()ed by __nf_queue already. */ - nfq_ct = rcu_dereference(nfq_ct_hook); - if (nfq_ct == NULL) - return NULL; - - ct = nf_ct_get(skb, ctinfo); - if (ct && !nf_ct_is_untracked(ct)) - nfq_ct->parse(attr, ct); - - return ct; -} - -int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo) -{ - struct nfq_ct_hook *nfq_ct; - struct nlattr *nest_parms; - u_int32_t tmp; - - nfq_ct = rcu_dereference(nfq_ct_hook); - if (nfq_ct == NULL) - return 0; - - nest_parms = nla_nest_start(skb, NFQA_CT | NLA_F_NESTED); - if (!nest_parms) - goto nla_put_failure; - - if (nfq_ct->build(skb, ct) < 0) - goto nla_put_failure; - - nla_nest_end(skb, nest_parms); - - tmp = ctinfo; - if (nla_put_be32(skb, NFQA_CT_INFO, htonl(tmp))) - goto nla_put_failure; - - return 0; - -nla_put_failure: - return -1; -} - -void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct, - enum ip_conntrack_info ctinfo, int diff) -{ - struct nfq_ct_hook *nfq_ct; - - nfq_ct = rcu_dereference(nfq_ct_hook); - if (nfq_ct == NULL) - return; - - if ((ct->status & IPS_NAT_MASK) && diff) - nfq_ct->seq_adjust(skb, ct, ctinfo, diff); -} - -int nfqnl_attach_expect(struct nf_conn *ct, const struct nlattr *attr, - u32 portid, u32 report) -{ - struct nfq_ct_hook *nfq_ct; - - if (nf_ct_is_untracked(ct)) - return 0; - - nfq_ct = rcu_dereference(nfq_ct_hook); - if (nfq_ct == NULL) - return -EOPNOTSUPP; - - return nfq_ct->attach_expect(attr, ct, portid, report); -} -- 2.20.1