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net: bridge: remove _deliver functions and consolidate forward code
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Before this patch we had two flavors of most forwarding functions -
_forward and _deliver, the difference being that the latter are used
when the packets are locally originated. Instead of all this function
pointer passing and code duplication, we can just pass a boolean noting
that the packet was locally originated and use that to perform the
necessary checks in __br_forward. This gives a minor performance
improvement but more importantly consolidates the forwarding paths.
Also add a kernel doc comment to explain the exported br_forward()'s
arguments.

Signed-off-by: Nikolay Aleksandrov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
Nikolay Aleksandrov authored and davem330 committed Jul 17, 2016
1 parent b35c5f6 commit 37b090e
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Showing 5 changed files with 94 additions and 153 deletions.
22 changes: 11 additions & 11 deletions net/bridge/br_device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,11 +61,11 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
goto out;

if (is_broadcast_ether_addr(dest))
br_flood_deliver(br, skb, false);
else if (is_multicast_ether_addr(dest)) {
if (is_broadcast_ether_addr(dest)) {
br_flood(br, skb, false, false, true);
} else if (is_multicast_ether_addr(dest)) {
if (unlikely(netpoll_tx_running(dev))) {
br_flood_deliver(br, skb, false);
br_flood(br, skb, false, false, true);
goto out;
}
if (br_multicast_rcv(br, NULL, skb, vid)) {
Expand All @@ -76,14 +76,14 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
mdst = br_mdb_get(br, skb, vid);
if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
br_multicast_querier_exists(br, eth_hdr(skb)))
br_multicast_deliver(mdst, skb);
br_multicast_flood(mdst, skb, false, true);
else
br_flood_deliver(br, skb, false);
} else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
br_deliver(dst->dst, skb);
else
br_flood_deliver(br, skb, true);

br_flood(br, skb, false, false, true);
} else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) {
br_forward(dst->dst, skb, false, true);
} else {
br_flood(br, skb, true, false, true);
}
out:
rcu_read_unlock();
return NETDEV_TX_OK;
Expand Down
184 changes: 65 additions & 119 deletions net/bridge/br_forward.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -21,11 +21,6 @@
#include <linux/netfilter_bridge.h>
#include "br_private.h"

static int deliver_clone(const struct net_bridge_port *prev,
struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb));

/* 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)
Expand Down Expand Up @@ -75,106 +70,92 @@ int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
}
EXPORT_SYMBOL_GPL(br_forward_finish);

static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
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;

vg = nbp_vlan_group_rcu(to);
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;

indev = skb->dev;
skb->dev = to->dev;

if (unlikely(netpoll_tx_running(to->br->dev))) {
if (!is_skb_forwardable(skb->dev, skb))
if (!local_orig) {
if (skb_warn_if_lro(skb)) {
kfree_skb(skb);
else {
skb_push(skb, ETH_HLEN);
br_netpoll_send_skb(to, skb);
return;
}
return;
br_hook = NF_BR_FORWARD;
skb_forward_csum(skb);
net = dev_net(indev);
} else {
if (unlikely(netpoll_tx_running(to->br->dev))) {
if (!is_skb_forwardable(skb->dev, skb)) {
kfree_skb(skb);
} else {
skb_push(skb, ETH_HLEN);
br_netpoll_send_skb(to, skb);
}
return;
}
br_hook = NF_BR_LOCAL_OUT;
net = dev_net(skb->dev);
indev = NULL;
}

NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
dev_net(skb->dev), NULL, skb,NULL, skb->dev,
NF_HOOK(NFPROTO_BRIDGE, br_hook,
net, NULL, skb, indev, skb->dev,
br_forward_finish);
}

static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
static int deliver_clone(const struct net_bridge_port *prev,
struct sk_buff *skb, bool local_orig)
{
struct net_bridge_vlan_group *vg;
struct net_device *indev;

if (skb_warn_if_lro(skb)) {
kfree_skb(skb);
return;
}

vg = nbp_vlan_group_rcu(to);
skb = br_handle_vlan(to->br, vg, skb);
if (!skb)
return;

indev = skb->dev;
skb->dev = to->dev;
skb_forward_csum(skb);

NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD,
dev_net(indev), NULL, skb, indev, skb->dev,
br_forward_finish);
}
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;

/* called with rcu_read_lock */
void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
{
if (to && should_deliver(to, skb)) {
__br_deliver(to, skb);
return;
skb = skb_clone(skb, GFP_ATOMIC);
if (!skb) {
dev->stats.tx_dropped++;
return -ENOMEM;
}

kfree_skb(skb);
__br_forward(prev, skb, local_orig);
return 0;
}
EXPORT_SYMBOL_GPL(br_deliver);

/* called with rcu_read_lock */
void br_forward(const struct net_bridge_port *to, struct sk_buff *skb,
bool local_rcv)
/**
* 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 (to && should_deliver(to, skb)) {
if (local_rcv)
deliver_clone(to, skb, __br_forward);
deliver_clone(to, skb, local_orig);
else
__br_forward(to, skb);
__br_forward(to, skb, local_orig);
return;
}

if (!local_rcv)
kfree_skb(skb);
}

static int deliver_clone(const struct net_bridge_port *prev,
struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb))
{
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;

skb = skb_clone(skb, GFP_ATOMIC);
if (!skb) {
dev->stats.tx_dropped++;
return -ENOMEM;
}

__packet_hook(prev, skb);
return 0;
}
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,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb))
struct sk_buff *skb, bool local_orig)
{
int err;

Expand All @@ -184,26 +165,22 @@ static struct net_bridge_port *maybe_deliver(
if (!prev)
goto out;

err = deliver_clone(prev, skb, __packet_hook);
err = deliver_clone(prev, skb, local_orig);
if (err)
return ERR_PTR(err);

out:
return p;
}

/* called under bridge lock */
static void br_flood(struct net_bridge *br, struct sk_buff *skb,
void (*__packet_hook)(const struct net_bridge_port *p,
struct sk_buff *skb),
bool local_rcv, bool unicast)
/* called under rcu_read_lock */
void br_flood(struct net_bridge *br, struct sk_buff *skb,
bool unicast, bool local_rcv, bool local_orig)
{
u8 igmp_type = br_multicast_igmp_type(skb);
struct net_bridge_port *prev;
struct net_bridge_port *prev = NULL;
struct net_bridge_port *p;

prev = NULL;

list_for_each_entry_rcu(p, &br->port_list, list) {
/* Do not flood unicast traffic to ports that turn it off */
if (unicast && !(p->flags & BR_FLOOD))
Expand All @@ -216,7 +193,7 @@ static void br_flood(struct net_bridge *br, struct sk_buff *skb,
BR_INPUT_SKB_CB(skb)->proxyarp_replied)
continue;

prev = maybe_deliver(prev, p, skb, __packet_hook);
prev = maybe_deliver(prev, p, skb, local_orig);
if (IS_ERR(prev))
goto out;
if (prev == p)
Expand All @@ -228,38 +205,21 @@ static void br_flood(struct net_bridge *br, struct sk_buff *skb,
goto out;

if (local_rcv)
deliver_clone(prev, skb, __packet_hook);
deliver_clone(prev, skb, local_orig);
else
__packet_hook(prev, skb);
__br_forward(prev, skb, local_orig);
return;

out:
if (!local_rcv)
kfree_skb(skb);
}


/* called with rcu_read_lock */
void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
{
br_flood(br, skb, __br_deliver, false, unicast);
}

/* called under bridge lock */
void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
bool local_rcv, bool unicast)
{
br_flood(br, skb, __br_forward, local_rcv, unicast);
}

#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
/* called with rcu_read_lock */
static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb,
void (*__packet_hook)(
const struct net_bridge_port *p,
struct sk_buff *skb),
bool local_rcv)
void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb,
bool local_rcv, bool local_orig)
{
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
u8 igmp_type = br_multicast_igmp_type(skb);
Expand All @@ -280,7 +240,7 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
port = (unsigned long)lport > (unsigned long)rport ?
lport : rport;

prev = maybe_deliver(prev, port, skb, __packet_hook);
prev = maybe_deliver(prev, port, skb, local_orig);
if (IS_ERR(prev))
goto out;
if (prev == port)
Expand All @@ -297,27 +257,13 @@ static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
goto out;

if (local_rcv)
deliver_clone(prev, skb, __packet_hook);
deliver_clone(prev, skb, local_orig);
else
__packet_hook(prev, skb);
__br_forward(prev, skb, local_orig);
return;

out:
if (!local_rcv)
kfree_skb(skb);
}

/* called with rcu_read_lock */
void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb)
{
br_multicast_flood(mdst, skb, __br_deliver, false);
}

/* called with rcu_read_lock */
void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
struct sk_buff *skb, bool local_rcv)
{
br_multicast_flood(mdst, skb, __br_forward, local_rcv);
}
#endif
6 changes: 3 additions & 3 deletions net/bridge/br_input.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -189,12 +189,12 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb

if (dst) {
dst->used = jiffies;
br_forward(dst->dst, skb, local_rcv);
br_forward(dst->dst, skb, local_rcv, false);
} else {
if (!mcast_hit)
br_flood_forward(br, skb, local_rcv, unicast);
br_flood(br, skb, unicast, local_rcv, false);
else
br_multicast_forward(mdst, skb, local_rcv);
br_multicast_flood(mdst, skb, local_rcv, false);
}

if (local_rcv)
Expand Down
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