[PATCH net-next 1/2] br_netfilter: add struct netns_brnf

From: Christian Brauner
Date: Wed Nov 07 2018 - 08:49:38 EST


This adds struct netns_brnf in preparation for per-network-namespace
br_netfilter settings. The individual br_netfilter sysctl options are moved
into a central place in struct net. The struct is only included when
the CONFIG_BRIDGE_NETFILTER kconfig option is enabled in the kernel.

Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Reviewed-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
---
include/net/net_namespace.h | 3 ++
include/net/netns/netfilter.h | 16 ++++++++
net/bridge/br_netfilter_hooks.c | 68 ++++++++++++++++-----------------
3 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 99d4148e0f90..bea0474cd3ea 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -125,6 +125,9 @@ struct net {
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct netns_ct ct;
#endif
+#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
+ struct netns_brnf brnf;
+#endif
#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
struct netns_nftables nft;
#endif
diff --git a/include/net/netns/netfilter.h b/include/net/netns/netfilter.h
index ca043342c0eb..eedbd1ac940e 100644
--- a/include/net/netns/netfilter.h
+++ b/include/net/netns/netfilter.h
@@ -35,4 +35,20 @@ struct netns_nf {
bool defrag_ipv6;
#endif
};
+
+struct netns_brnf {
+#ifdef CONFIG_SYSCTL
+ struct ctl_table_header *ctl_hdr;
+#endif
+
+ /* default value is 1 */
+ int call_iptables;
+ int call_ip6tables;
+ int call_arptables;
+
+ /* default value is 0 */
+ int filter_vlan_tagged;
+ int filter_pppoe_tagged;
+ int pass_vlan_indev;
+};
#endif
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index b1b5e8516724..656a084f4825 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -53,23 +53,6 @@ struct brnf_net {
bool enabled;
};

-#ifdef CONFIG_SYSCTL
-static struct ctl_table_header *brnf_sysctl_header;
-static int brnf_call_iptables __read_mostly = 1;
-static int brnf_call_ip6tables __read_mostly = 1;
-static int brnf_call_arptables __read_mostly = 1;
-static int brnf_filter_vlan_tagged __read_mostly;
-static int brnf_filter_pppoe_tagged __read_mostly;
-static int brnf_pass_vlan_indev __read_mostly;
-#else
-#define brnf_call_iptables 1
-#define brnf_call_ip6tables 1
-#define brnf_call_arptables 1
-#define brnf_filter_vlan_tagged 0
-#define brnf_filter_pppoe_tagged 0
-#define brnf_pass_vlan_indev 0
-#endif
-
#define IS_IP(skb) \
(!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP))

@@ -91,15 +74,15 @@ static inline __be16 vlan_proto(const struct sk_buff *skb)

#define IS_VLAN_IP(skb) \
(vlan_proto(skb) == htons(ETH_P_IP) && \
- brnf_filter_vlan_tagged)
+ init_net.brnf.filter_vlan_tagged)

#define IS_VLAN_IPV6(skb) \
(vlan_proto(skb) == htons(ETH_P_IPV6) && \
- brnf_filter_vlan_tagged)
+ init_net.brnf.filter_vlan_tagged)

#define IS_VLAN_ARP(skb) \
(vlan_proto(skb) == htons(ETH_P_ARP) && \
- brnf_filter_vlan_tagged)
+ init_net.brnf.filter_vlan_tagged)

static inline __be16 pppoe_proto(const struct sk_buff *skb)
{
@@ -110,12 +93,12 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb)
#define IS_PPPOE_IP(skb) \
(skb->protocol == htons(ETH_P_PPP_SES) && \
pppoe_proto(skb) == htons(PPP_IP) && \
- brnf_filter_pppoe_tagged)
+ init_net.brnf.filter_pppoe_tagged)

#define IS_PPPOE_IPV6(skb) \
(skb->protocol == htons(ETH_P_PPP_SES) && \
pppoe_proto(skb) == htons(PPP_IPV6) && \
- brnf_filter_pppoe_tagged)
+ init_net.brnf.filter_pppoe_tagged)

/* largest possible L2 header, see br_nf_dev_queue_xmit() */
#define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)
@@ -430,7 +413,7 @@ static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct
struct net_device *vlan, *br;

br = bridge_parent(dev);
- if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
+ if (init_net.brnf.pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
return br;

vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
@@ -487,7 +470,7 @@ static unsigned int br_nf_pre_routing(void *priv,
br = p->br;

if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) {
- if (!brnf_call_ip6tables &&
+ if (!init_net.brnf.call_ip6tables &&
!br_opt_get(br, BROPT_NF_CALL_IP6TABLES))
return NF_ACCEPT;

@@ -495,7 +478,8 @@ static unsigned int br_nf_pre_routing(void *priv,
return br_nf_pre_routing_ipv6(priv, skb, state);
}

- if (!brnf_call_iptables && !br_opt_get(br, BROPT_NF_CALL_IPTABLES))
+ if (!init_net.brnf.call_iptables &&
+ !br_opt_get(br, BROPT_NF_CALL_IPTABLES))
return NF_ACCEPT;

if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb))
@@ -637,7 +621,8 @@ static unsigned int br_nf_forward_arp(void *priv,
return NF_ACCEPT;
br = p->br;

- if (!brnf_call_arptables && !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
+ if (!init_net.brnf.call_arptables &&
+ !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
return NF_ACCEPT;

if (!IS_ARP(skb)) {
@@ -1032,42 +1017,42 @@ int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
static struct ctl_table brnf_table[] = {
{
.procname = "bridge-nf-call-arptables",
- .data = &brnf_call_arptables,
+ .data = &init_net.brnf.call_arptables,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
},
{
.procname = "bridge-nf-call-iptables",
- .data = &brnf_call_iptables,
+ .data = &init_net.brnf.call_iptables,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
},
{
.procname = "bridge-nf-call-ip6tables",
- .data = &brnf_call_ip6tables,
+ .data = &init_net.brnf.call_ip6tables,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
},
{
.procname = "bridge-nf-filter-vlan-tagged",
- .data = &brnf_filter_vlan_tagged,
+ .data = &init_net.brnf.filter_vlan_tagged,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
},
{
.procname = "bridge-nf-filter-pppoe-tagged",
- .data = &brnf_filter_pppoe_tagged,
+ .data = &init_net.brnf.filter_pppoe_tagged,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
},
{
.procname = "bridge-nf-pass-vlan-input-dev",
- .data = &brnf_pass_vlan_indev,
+ .data = &init_net.brnf.pass_vlan_indev,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = brnf_sysctl_call_tables,
@@ -1076,6 +1061,16 @@ static struct ctl_table brnf_table[] = {
};
#endif

+static inline void br_netfilter_sysctl_default(struct netns_brnf *brnf)
+{
+ brnf->call_iptables = 1;
+ brnf->call_ip6tables = 1;
+ brnf->call_arptables = 1;
+ brnf->filter_vlan_tagged = 0;
+ brnf->filter_pppoe_tagged = 0;
+ brnf->pass_vlan_indev = 0;
+}
+
static int __init br_netfilter_init(void)
{
int ret;
@@ -1090,9 +1085,12 @@ static int __init br_netfilter_init(void)
return ret;
}

+ /* Always set default values. Even if CONFIG_SYSCTL is not set. */
+ br_netfilter_sysctl_default(&init_net.brnf);
+
#ifdef CONFIG_SYSCTL
- brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table);
- if (brnf_sysctl_header == NULL) {
+ init_net.brnf.ctl_hdr = register_net_sysctl(&init_net, "net/bridge", brnf_table);
+ if (!init_net.brnf.ctl_hdr) {
printk(KERN_WARNING
"br_netfilter: can't register to sysctl.\n");
unregister_netdevice_notifier(&brnf_notifier);
@@ -1111,7 +1109,7 @@ static void __exit br_netfilter_fini(void)
unregister_netdevice_notifier(&brnf_notifier);
unregister_pernet_subsys(&brnf_net_ops);
#ifdef CONFIG_SYSCTL
- unregister_net_sysctl_table(brnf_sysctl_header);
+ unregister_net_sysctl_table(init_net.brnf.ctl_hdr);
#endif
}

--
2.19.1