netfilter: bridge: port sysctls to use brnf_net

This ports the sysctls to use struct brnf_net.

With this patch we make it possible to namespace the br_netfilter module in
the following patch.

Signed-off-by: Christian Brauner <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

include/net/netfilter/br_netfilter.h

···
 	return port ? &port->br->fake_rtable : NULL;
 }
 
-struct net_device *setup_pre_routing(struct sk_buff *skb);
+struct net_device *setup_pre_routing(struct sk_buff *skb,
+				     const struct net *net);
 
 #if IS_ENABLED(CONFIG_IPV6)
 int br_validate_ipv6(struct net *net, struct sk_buff *skb);

net/bridge/br_netfilter_hooks.c

···
 
 static unsigned int brnf_net_id __read_mostly;
 
-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
+
+struct brnf_net {
+	bool enabled;
+
+	/* 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;
+};
 
 #define IS_IP(skb) \
 	(!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
···
 		return 0;
 }
 
-#define IS_VLAN_IP(skb) \
-	(vlan_proto(skb) == htons(ETH_P_IP) && \
-	 brnf_filter_vlan_tagged)
+static inline bool is_vlan_ip(const struct sk_buff *skb, const struct net *net)
+{
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
 
-#define IS_VLAN_IPV6(skb) \
-	(vlan_proto(skb) == htons(ETH_P_IPV6) && \
-	 brnf_filter_vlan_tagged)
+	return vlan_proto(skb) == htons(ETH_P_IP) && brnet->filter_vlan_tagged;
+}
 
-#define IS_VLAN_ARP(skb) \
-	(vlan_proto(skb) == htons(ETH_P_ARP) &&	\
-	 brnf_filter_vlan_tagged)
+static inline bool is_vlan_ipv6(const struct sk_buff *skb,
+				const struct net *net)
+{
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
+
+	return vlan_proto(skb) == htons(ETH_P_IPV6) &&
+	       brnet->filter_vlan_tagged;
+}
+
+static inline bool is_vlan_arp(const struct sk_buff *skb, const struct net *net)
+{
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
+
+	return vlan_proto(skb) == htons(ETH_P_ARP) && brnet->filter_vlan_tagged;
+}
 
 static inline __be16 pppoe_proto(const struct sk_buff *skb)
 {
···
 			    sizeof(struct pppoe_hdr)));
 }
 
-#define IS_PPPOE_IP(skb) \
-	(skb->protocol == htons(ETH_P_PPP_SES) && \
-	 pppoe_proto(skb) == htons(PPP_IP) && \
-	 brnf_filter_pppoe_tagged)
+static inline bool is_pppoe_ip(const struct sk_buff *skb, const struct net *net)
+{
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
 
-#define IS_PPPOE_IPV6(skb) \
-	(skb->protocol == htons(ETH_P_PPP_SES) && \
-	 pppoe_proto(skb) == htons(PPP_IPV6) && \
-	 brnf_filter_pppoe_tagged)
+	return skb->protocol == htons(ETH_P_PPP_SES) &&
+	       pppoe_proto(skb) == htons(PPP_IP) && brnet->filter_pppoe_tagged;
+}
+
+static inline bool is_pppoe_ipv6(const struct sk_buff *skb,
+				 const struct net *net)
+{
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
+
+	return skb->protocol == htons(ETH_P_PPP_SES) &&
+	       pppoe_proto(skb) == htons(PPP_IPV6) &&
+	       brnet->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)
···
 	return 0;
 }
 
-static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev)
+static struct net_device *brnf_get_logical_dev(struct sk_buff *skb,
+					       const struct net_device *dev,
+					       const struct net *net)
 {
 	struct net_device *vlan, *br;
+	struct brnf_net *brnet = net_generic(net, brnf_net_id);
 
 	br = bridge_parent(dev);
-	if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
+
+	if (brnet->pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
 		return br;
 
 	vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
···
 }
 
 /* Some common code for IPv4/IPv6 */
-struct net_device *setup_pre_routing(struct sk_buff *skb)
+struct net_device *setup_pre_routing(struct sk_buff *skb, const struct net *net)
 {
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 
···
 
 	nf_bridge->in_prerouting = 1;
 	nf_bridge->physindev = skb->dev;
-	skb->dev = brnf_get_logical_dev(skb, skb->dev);
+	skb->dev = brnf_get_logical_dev(skb, skb->dev, net);
 
 	if (skb->protocol == htons(ETH_P_8021Q))
 		nf_bridge->orig_proto = BRNF_PROTO_8021Q;
···
 	struct net_bridge_port *p;
 	struct net_bridge *br;
 	__u32 len = nf_bridge_encap_header_len(skb);
+	struct brnf_net *brnet;
 
 	if (unlikely(!pskb_may_pull(skb, len)))
 		return NF_DROP;
···
 		return NF_DROP;
 	br = p->br;
 
-	if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) {
-		if (!brnf_call_ip6tables &&
+	brnet = net_generic(state->net, brnf_net_id);
+	if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
+	    is_pppoe_ipv6(skb, state->net)) {
+		if (!brnet->call_ip6tables &&
 		    !br_opt_get(br, BROPT_NF_CALL_IP6TABLES))
 			return NF_ACCEPT;
 
···
 		return br_nf_pre_routing_ipv6(priv, skb, state);
 	}
 
-	if (!brnf_call_iptables && !br_opt_get(br, BROPT_NF_CALL_IPTABLES))
+	if (!brnet->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))
+	if (!IS_IP(skb) && !is_vlan_ip(skb, state->net) &&
+	    !is_pppoe_ip(skb, state->net))
 		return NF_ACCEPT;
 
 	nf_bridge_pull_encap_header_rcsum(skb);
···
 
 	if (!nf_bridge_alloc(skb))
 		return NF_DROP;
-	if (!setup_pre_routing(skb))
+	if (!setup_pre_routing(skb, state->net))
 		return NF_DROP;
 
 	nf_bridge = nf_bridge_info_get(skb);
···
 	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 	struct net_device *in;
 
-	if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
+	if (!IS_ARP(skb) && !is_vlan_arp(skb, net)) {
 
 		if (skb->protocol == htons(ETH_P_IP))
 			nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
···
 	if (!parent)
 		return NF_DROP;
 
-	if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
+	if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
+	    is_pppoe_ip(skb, state->net))
 		pf = NFPROTO_IPV4;
-	else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
+	else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
+		 is_pppoe_ipv6(skb, state->net))
 		pf = NFPROTO_IPV6;
 	else
 		return NF_ACCEPT;
···
 		skb->protocol = htons(ETH_P_IPV6);
 
 	NF_HOOK(pf, NF_INET_FORWARD, state->net, NULL, skb,
-		brnf_get_logical_dev(skb, state->in),
+		brnf_get_logical_dev(skb, state->in, state->net),
 		parent,	br_nf_forward_finish);
 
 	return NF_STOLEN;
···
 	struct net_bridge_port *p;
 	struct net_bridge *br;
 	struct net_device **d = (struct net_device **)(skb->cb);
+	struct brnf_net *brnet;
 
 	p = br_port_get_rcu(state->out);
 	if (p == NULL)
 		return NF_ACCEPT;
 	br = p->br;
 
-	if (!brnf_call_arptables && !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
+	brnet = net_generic(state->net, brnf_net_id);
+	if (!brnet->call_arptables && !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
 		return NF_ACCEPT;
 
 	if (!IS_ARP(skb)) {
-		if (!IS_VLAN_ARP(skb))
+		if (!is_vlan_arp(skb, state->net))
 			return NF_ACCEPT;
 		nf_bridge_pull_encap_header(skb);
 	}
 
 	if (arp_hdr(skb)->ar_pln != 4) {
-		if (IS_VLAN_ARP(skb))
+		if (is_vlan_arp(skb, state->net))
 			nf_bridge_push_encap_header(skb);
 		return NF_ACCEPT;
 	}
···
 	if (!realoutdev)
 		return NF_DROP;
 
-	if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
+	if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
+	    is_pppoe_ip(skb, state->net))
 		pf = NFPROTO_IPV4;
-	else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
+	else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
+		 is_pppoe_ipv6(skb, state->net))
 		pf = NFPROTO_IPV6;
 	else
 		return NF_ACCEPT;
···
 static struct ctl_table brnf_table[] = {
 	{
 		.procname	= "bridge-nf-call-arptables",
-		.data		= &brnf_call_arptables,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= brnf_sysctl_call_tables,
 	},
 	{
 		.procname	= "bridge-nf-call-iptables",
-		.data		= &brnf_call_iptables,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= brnf_sysctl_call_tables,
 	},
 	{
 		.procname	= "bridge-nf-call-ip6tables",
-		.data		= &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,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= brnf_sysctl_call_tables,
 	},
 	{
 		.procname	= "bridge-nf-filter-pppoe-tagged",
-		.data		= &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,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= brnf_sysctl_call_tables,
 	},
 	{ }
 };
+
+static inline void br_netfilter_sysctl_default(struct brnf_net *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;
+}
+
 #endif
 
 static int __init br_netfilter_init(void)
 {
 	int ret;
+	struct brnf_net *brnet;
 
 	ret = register_pernet_subsys(&brnf_net_ops);
 	if (ret < 0)
···
 	}
 
 #ifdef CONFIG_SYSCTL
+	brnet = net_generic(&init_net, brnf_net_id);
+	brnf_table[0].data = &brnet->call_arptables;
+	brnf_table[1].data = &brnet->call_iptables;
+	brnf_table[2].data = &brnet->call_ip6tables;
+	brnf_table[3].data = &brnet->filter_vlan_tagged;
+	brnf_table[4].data = &brnet->filter_pppoe_tagged;
+	brnf_table[5].data = &brnet->pass_vlan_indev;
+
+	br_netfilter_sysctl_default(brnet);
+
 	brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table);
 	if (brnf_sysctl_header == NULL) {
 		printk(KERN_WARNING

net/bridge/br_netfilter_ipv6.c

···
 	nf_bridge = nf_bridge_alloc(skb);
 	if (!nf_bridge)
 		return NF_DROP;
-	if (!setup_pre_routing(skb))
+	if (!setup_pre_routing(skb, state->net))
 		return NF_DROP;
 
 	nf_bridge = nf_bridge_info_get(skb);