forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
343 lines
7.8 KiB
343 lines
7.8 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Forwarding decision |
|
* Linux ethernet bridge |
|
* |
|
* Authors: |
|
* Lennert Buytenhek <[email protected]> |
|
*/ |
|
|
|
#include <linux/err.h> |
|
#include <linux/slab.h> |
|
#include <linux/kernel.h> |
|
#include <linux/netdevice.h> |
|
#include <linux/netpoll.h> |
|
#include <linux/skbuff.h> |
|
#include <linux/if_vlan.h> |
|
#include <linux/netfilter_bridge.h> |
|
#include "br_private.h" |
|
|
|
/* Don't forward packets to originating port or forwarding disabled */ |
|
static inline int should_deliver(const struct net_bridge_port *p, |
|
const struct sk_buff *skb) |
|
{ |
|
struct net_bridge_vlan_group *vg; |
|
|
|
vg = nbp_vlan_group_rcu(p); |
|
return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
|
p->state == BR_STATE_FORWARDING && br_allowed_egress(vg, skb) && |
|
nbp_switchdev_allowed_egress(p, skb) && |
|
!br_skb_isolated(p, skb); |
|
} |
|
|
|
int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) |
|
{ |
|
skb_push(skb, ETH_HLEN); |
|
if (!is_skb_forwardable(skb->dev, skb)) |
|
goto drop; |
|
|
|
br_drop_fake_rtable(skb); |
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL && |
|
eth_type_vlan(skb->protocol)) { |
|
int depth; |
|
|
|
if (!__vlan_get_protocol(skb, skb->protocol, &depth)) |
|
goto drop; |
|
|
|
skb_set_network_header(skb, depth); |
|
} |
|
|
|
br_switchdev_frame_set_offload_fwd_mark(skb); |
|
|
|
dev_queue_xmit(skb); |
|
|
|
return 0; |
|
|
|
drop: |
|
kfree_skb(skb); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
|
|
|
int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
|
{ |
|
skb->tstamp = 0; |
|
return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, |
|
net, sk, skb, NULL, skb->dev, |
|
br_dev_queue_push_xmit); |
|
|
|
} |
|
EXPORT_SYMBOL_GPL(br_forward_finish); |
|
|
|
static void __br_forward(const struct net_bridge_port *to, |
|
struct sk_buff *skb, bool local_orig) |
|
{ |
|
struct net_bridge_vlan_group *vg; |
|
struct net_device *indev; |
|
struct net *net; |
|
int br_hook; |
|
|
|
/* Mark the skb for forwarding offload early so that br_handle_vlan() |
|
* can know whether to pop the VLAN header on egress or keep it. |
|
*/ |
|
nbp_switchdev_frame_mark_tx_fwd_offload(to, skb); |
|
|
|
vg = nbp_vlan_group_rcu(to); |
|
skb = br_handle_vlan(to->br, to, vg, skb); |
|
if (!skb) |
|
return; |
|
|
|
indev = skb->dev; |
|
skb->dev = to->dev; |
|
if (!local_orig) { |
|
if (skb_warn_if_lro(skb)) { |
|
kfree_skb(skb); |
|
return; |
|
} |
|
br_hook = NF_BR_FORWARD; |
|
skb_forward_csum(skb); |
|
net = dev_net(indev); |
|
} else { |
|
if (unlikely(netpoll_tx_running(to->br->dev))) { |
|
skb_push(skb, ETH_HLEN); |
|
if (!is_skb_forwardable(skb->dev, skb)) |
|
kfree_skb(skb); |
|
else |
|
br_netpoll_send_skb(to, skb); |
|
return; |
|
} |
|
br_hook = NF_BR_LOCAL_OUT; |
|
net = dev_net(skb->dev); |
|
indev = NULL; |
|
} |
|
|
|
NF_HOOK(NFPROTO_BRIDGE, br_hook, |
|
net, NULL, skb, indev, skb->dev, |
|
br_forward_finish); |
|
} |
|
|
|
static int deliver_clone(const struct net_bridge_port *prev, |
|
struct sk_buff *skb, bool local_orig) |
|
{ |
|
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
|
|
|
skb = skb_clone(skb, GFP_ATOMIC); |
|
if (!skb) { |
|
dev->stats.tx_dropped++; |
|
return -ENOMEM; |
|
} |
|
|
|
__br_forward(prev, skb, local_orig); |
|
return 0; |
|
} |
|
|
|
/** |
|
* br_forward - forward a packet to a specific port |
|
* @to: destination port |
|
* @skb: packet being forwarded |
|
* @local_rcv: packet will be received locally after forwarding |
|
* @local_orig: packet is locally originated |
|
* |
|
* Should be called with rcu_read_lock. |
|
*/ |
|
void br_forward(const struct net_bridge_port *to, |
|
struct sk_buff *skb, bool local_rcv, bool local_orig) |
|
{ |
|
if (unlikely(!to)) |
|
goto out; |
|
|
|
/* redirect to backup link if the destination port is down */ |
|
if (rcu_access_pointer(to->backup_port) && !netif_carrier_ok(to->dev)) { |
|
struct net_bridge_port *backup_port; |
|
|
|
backup_port = rcu_dereference(to->backup_port); |
|
if (unlikely(!backup_port)) |
|
goto out; |
|
to = backup_port; |
|
} |
|
|
|
if (should_deliver(to, skb)) { |
|
if (local_rcv) |
|
deliver_clone(to, skb, local_orig); |
|
else |
|
__br_forward(to, skb, local_orig); |
|
return; |
|
} |
|
|
|
out: |
|
if (!local_rcv) |
|
kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL_GPL(br_forward); |
|
|
|
static struct net_bridge_port *maybe_deliver( |
|
struct net_bridge_port *prev, struct net_bridge_port *p, |
|
struct sk_buff *skb, bool local_orig) |
|
{ |
|
u8 igmp_type = br_multicast_igmp_type(skb); |
|
int err; |
|
|
|
if (!should_deliver(p, skb)) |
|
return prev; |
|
|
|
nbp_switchdev_frame_mark_tx_fwd_to_hwdom(p, skb); |
|
|
|
if (!prev) |
|
goto out; |
|
|
|
err = deliver_clone(prev, skb, local_orig); |
|
if (err) |
|
return ERR_PTR(err); |
|
out: |
|
br_multicast_count(p->br, p, skb, igmp_type, BR_MCAST_DIR_TX); |
|
|
|
return p; |
|
} |
|
|
|
/* called under rcu_read_lock */ |
|
void br_flood(struct net_bridge *br, struct sk_buff *skb, |
|
enum br_pkt_type pkt_type, bool local_rcv, bool local_orig) |
|
{ |
|
struct net_bridge_port *prev = NULL; |
|
struct net_bridge_port *p; |
|
|
|
list_for_each_entry_rcu(p, &br->port_list, list) { |
|
/* Do not flood unicast traffic to ports that turn it off, nor |
|
* other traffic if flood off, except for traffic we originate |
|
*/ |
|
switch (pkt_type) { |
|
case BR_PKT_UNICAST: |
|
if (!(p->flags & BR_FLOOD)) |
|
continue; |
|
break; |
|
case BR_PKT_MULTICAST: |
|
if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev) |
|
continue; |
|
break; |
|
case BR_PKT_BROADCAST: |
|
if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev) |
|
continue; |
|
break; |
|
} |
|
|
|
/* Do not flood to ports that enable proxy ARP */ |
|
if (p->flags & BR_PROXYARP) |
|
continue; |
|
if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) && |
|
BR_INPUT_SKB_CB(skb)->proxyarp_replied) |
|
continue; |
|
|
|
prev = maybe_deliver(prev, p, skb, local_orig); |
|
if (IS_ERR(prev)) |
|
goto out; |
|
} |
|
|
|
if (!prev) |
|
goto out; |
|
|
|
if (local_rcv) |
|
deliver_clone(prev, skb, local_orig); |
|
else |
|
__br_forward(prev, skb, local_orig); |
|
return; |
|
|
|
out: |
|
if (!local_rcv) |
|
kfree_skb(skb); |
|
} |
|
|
|
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING |
|
static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb, |
|
const unsigned char *addr, bool local_orig) |
|
{ |
|
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
|
const unsigned char *src = eth_hdr(skb)->h_source; |
|
|
|
if (!should_deliver(p, skb)) |
|
return; |
|
|
|
/* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */ |
|
if (skb->dev == p->dev && ether_addr_equal(src, addr)) |
|
return; |
|
|
|
skb = skb_copy(skb, GFP_ATOMIC); |
|
if (!skb) { |
|
dev->stats.tx_dropped++; |
|
return; |
|
} |
|
|
|
if (!is_broadcast_ether_addr(addr)) |
|
memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN); |
|
|
|
__br_forward(p, skb, local_orig); |
|
} |
|
|
|
/* called with rcu_read_lock */ |
|
void br_multicast_flood(struct net_bridge_mdb_entry *mdst, |
|
struct sk_buff *skb, |
|
struct net_bridge_mcast *brmctx, |
|
bool local_rcv, bool local_orig) |
|
{ |
|
struct net_bridge_port *prev = NULL; |
|
struct net_bridge_port_group *p; |
|
bool allow_mode_include = true; |
|
struct hlist_node *rp; |
|
|
|
rp = br_multicast_get_first_rport_node(brmctx, skb); |
|
|
|
if (mdst) { |
|
p = rcu_dereference(mdst->ports); |
|
if (br_multicast_should_handle_mode(brmctx, mdst->addr.proto) && |
|
br_multicast_is_star_g(&mdst->addr)) |
|
allow_mode_include = false; |
|
} else { |
|
p = NULL; |
|
} |
|
|
|
while (p || rp) { |
|
struct net_bridge_port *port, *lport, *rport; |
|
|
|
lport = p ? p->key.port : NULL; |
|
rport = br_multicast_rport_from_node_skb(rp, skb); |
|
|
|
if ((unsigned long)lport > (unsigned long)rport) { |
|
port = lport; |
|
|
|
if (port->flags & BR_MULTICAST_TO_UNICAST) { |
|
maybe_deliver_addr(lport, skb, p->eth_addr, |
|
local_orig); |
|
goto delivered; |
|
} |
|
if ((!allow_mode_include && |
|
p->filter_mode == MCAST_INCLUDE) || |
|
(p->flags & MDB_PG_FLAGS_BLOCKED)) |
|
goto delivered; |
|
} else { |
|
port = rport; |
|
} |
|
|
|
prev = maybe_deliver(prev, port, skb, local_orig); |
|
if (IS_ERR(prev)) |
|
goto out; |
|
delivered: |
|
if ((unsigned long)lport >= (unsigned long)port) |
|
p = rcu_dereference(p->next); |
|
if ((unsigned long)rport >= (unsigned long)port) |
|
rp = rcu_dereference(hlist_next_rcu(rp)); |
|
} |
|
|
|
if (!prev) |
|
goto out; |
|
|
|
if (local_rcv) |
|
deliver_clone(prev, skb, local_orig); |
|
else |
|
__br_forward(prev, skb, local_orig); |
|
return; |
|
|
|
out: |
|
if (!local_rcv) |
|
kfree_skb(skb); |
|
} |
|
#endif
|
|
|