netfilter: bridge: optionally set indev to vlan

if net.bridge.bridge-nf-filter-vlan-tagged sysctl is enabled, bridge
netfilter removes the vlan header temporarily and then feeds the packet
to ip(6)tables.

When the new "bridge-nf-pass-vlan-input-device" sysctl is on
(default off), then bridge netfilter will also set the
in-interface to the vlan interface; if such an interface exists.

This is needed to make iptables REDIRECT target work with
"vlan-on-top-of-bridge" setups and to allow use of "iptables -i" to
match the vlan device name.

Also update Documentation with current brnf default settings.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2012-05-08 19:36:44 +02:00
parent ac3a546ac8
commit 4981682cc1
2 changed files with 35 additions and 4 deletions

View File

@ -1301,13 +1301,22 @@ bridge-nf-call-ip6tables - BOOLEAN
bridge-nf-filter-vlan-tagged - BOOLEAN bridge-nf-filter-vlan-tagged - BOOLEAN
1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables. 1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables.
0 : disable this. 0 : disable this.
Default: 1 Default: 0
bridge-nf-filter-pppoe-tagged - BOOLEAN bridge-nf-filter-pppoe-tagged - BOOLEAN
1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables. 1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables.
0 : disable this. 0 : disable this.
Default: 1 Default: 0
bridge-nf-pass-vlan-input-dev - BOOLEAN
1: if bridge-nf-filter-vlan-tagged is enabled, try to find a vlan
interface on the bridge and set the netfilter input device to the vlan.
This allows use of e.g. "iptables -i br0.1" and makes the REDIRECT
target work with vlan-on-top-of-bridge interfaces. When no matching
vlan interface is found, or this switch is off, the input device is
set to the bridge interface.
0: disable bridge netfilter vlan interface lookup.
Default: 0
proc/sys/net/sctp/* Variables: proc/sys/net/sctp/* Variables:

View File

@ -54,12 +54,14 @@ static int brnf_call_ip6tables __read_mostly = 1;
static int brnf_call_arptables __read_mostly = 1; static int brnf_call_arptables __read_mostly = 1;
static int brnf_filter_vlan_tagged __read_mostly = 0; static int brnf_filter_vlan_tagged __read_mostly = 0;
static int brnf_filter_pppoe_tagged __read_mostly = 0; static int brnf_filter_pppoe_tagged __read_mostly = 0;
static int brnf_pass_vlan_indev __read_mostly = 0;
#else #else
#define brnf_call_iptables 1 #define brnf_call_iptables 1
#define brnf_call_ip6tables 1 #define brnf_call_ip6tables 1
#define brnf_call_arptables 1 #define brnf_call_arptables 1
#define brnf_filter_vlan_tagged 0 #define brnf_filter_vlan_tagged 0
#define brnf_filter_pppoe_tagged 0 #define brnf_filter_pppoe_tagged 0
#define brnf_pass_vlan_indev 0
#endif #endif
#define IS_IP(skb) \ #define IS_IP(skb) \
@ -503,6 +505,19 @@ bridged_dnat:
return 0; return 0;
} }
static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev)
{
struct net_device *vlan, *br;
br = bridge_parent(dev);
if (brnf_pass_vlan_indev == 0 || !vlan_tx_tag_present(skb))
return br;
vlan = __vlan_find_dev_deep(br, vlan_tx_tag_get(skb) & VLAN_VID_MASK);
return vlan ? vlan : br;
}
/* Some common code for IPv4/IPv6 */ /* Some common code for IPv4/IPv6 */
static struct net_device *setup_pre_routing(struct sk_buff *skb) static struct net_device *setup_pre_routing(struct sk_buff *skb)
{ {
@ -515,7 +530,7 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb)
nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING; nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->physindev = skb->dev; nf_bridge->physindev = skb->dev;
skb->dev = bridge_parent(skb->dev); skb->dev = brnf_get_logical_dev(skb, skb->dev);
if (skb->protocol == htons(ETH_P_8021Q)) if (skb->protocol == htons(ETH_P_8021Q))
nf_bridge->mask |= BRNF_8021Q; nf_bridge->mask |= BRNF_8021Q;
else if (skb->protocol == htons(ETH_P_PPP_SES)) else if (skb->protocol == htons(ETH_P_PPP_SES))
@ -774,7 +789,7 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb,
else else
skb->protocol = htons(ETH_P_IPV6); skb->protocol = htons(ETH_P_IPV6);
NF_HOOK(pf, NF_INET_FORWARD, skb, bridge_parent(in), parent, NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent,
br_nf_forward_finish); br_nf_forward_finish);
return NF_STOLEN; return NF_STOLEN;
@ -1002,6 +1017,13 @@ static ctl_table brnf_table[] = {
.mode = 0644, .mode = 0644,
.proc_handler = brnf_sysctl_call_tables, .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,
},
{ } { }
}; };
#endif #endif