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Message-Id: <1445081590-2924-3-git-send-email-pablo@netfilter.org>
Date: Sat, 17 Oct 2015 13:32:37 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 02/35] 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 <pablo@...filter.org>
---
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 165ab2d..3e5e8f2 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 aff88ba..0000000
--- a/include/net/netfilter/nfnetlink_queue.h
+++ /dev/null
@@ -1,51 +0,0 @@
-#ifndef _NET_NFNL_QUEUE_H_
-#define _NET_NFNL_QUEUE_H_
-
-#include <linux/netfilter/nf_conntrack_common.h>
-
-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 70d026d..4d68e72 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 2e90733..1412e36 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 94a6654..eb67bf8 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;
@@ -2236,6 +2247,31 @@ nla_put_failure:
}
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)
{
int err;
@@ -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 41583e3..b1f1c74 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -28,12 +28,12 @@
#include <linux/netfilter_bridge.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_queue.h>
+#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/list.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/netfilter/nf_queue.h>
#include <net/netns/generic.h>
-#include <net/netfilter/nfnetlink_queue.h>
#include <linux/atomic.h>
@@ -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 96cac50..0000000
--- a/net/netfilter/nfnetlink_queue_ct.c
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * (C) 2012 by Pablo Neira Ayuso <pablo@...filter.org>
- *
- * 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 <linux/skbuff.h>
-#include <linux/netfilter.h>
-#include <linux/netfilter/nfnetlink.h>
-#include <linux/netfilter/nfnetlink_queue.h>
-#include <net/netfilter/nf_conntrack.h>
-#include <net/netfilter/nfnetlink_queue.h>
-
-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);
-}
--
2.1.4
--
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