It just xor hashes over IPv4/IPv6 addresses and ports of transport.
The only assumption it makes is that skb_network_header() is set
correctly.
With bug fixes from Eric Dumazet.
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
net/core/dev.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 52 insertions(+), 0 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 7ca9564..467bfb3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -121,6 +121,9 @@
#include <linux/ctype.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
#include "net-sysfs.h"
@@ -1665,6 +1668,53 @@ out_kfree_skb:
* --BLG
*/
+static u16 simple_tx_hash(struct net_device *dev, struct sk_buff *skb)
+{
+ u32 *addr, *ports, hash, ihl;
+ u8 ip_proto;
+ int alen;
+
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ ip_proto = ip_hdr(skb)->protocol;
+ addr = &ip_hdr(skb)->saddr;
+ ihl = ip_hdr(skb)->ihl;
+ alen = 2;
+ break;
+ case __constant_htons(ETH_P_IPV6):
+ ip_proto = ipv6_hdr(skb)->nexthdr;
+ addr = &ipv6_hdr(skb)->saddr.s6_addr32[0];
+ ihl = (40 >> 2);
+ alen = 8;
+ break;
+ default:
+ return 0;
+ }
+
+ ports = (u32 *) (skb_network_header(skb) + (ihl * 4));
+
+ hash = 0;
+ while (alen--)
+ hash ^= *addr++;
+
+ switch (ip_proto) {
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
+ case IPPROTO_DCCP:
+ case IPPROTO_ESP:
+ case IPPROTO_AH:
+ case IPPROTO_SCTP:
+ case IPPROTO_UDPLITE:
+ hash ^= *ports;
+ break;
+
+ default:
+ break;
+ }
+
+ return hash % dev->real_num_tx_queues;
+}
+
static struct netdev_queue *dev_pick_tx(struct net_device *dev,
struct sk_buff *skb)
{
@@ -1672,6 +1722,8 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev,
if (dev->select_queue)
queue_index = dev->select_queue(dev, skb);
+ else if (dev->real_num_tx_queues > 1)
+ queue_index = simple_tx_hash(dev, skb);
skb_set_queue_mapping(skb, queue_index);
return netdev_get_tx_queue(dev, queue_index);
--
1.5.6.2.255.gbed62
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
