ipv4: Support multipath hashing on inner IP pkts for GRE tunnel (363887a2) · Commits · 戴 / test

Multipath hash policy value of 0 isn't distributing since the outer IP dest and src aren't varied eventhough the inner ones are. Since the flow is on the inner ones in the case of tunneled traffic, hashing on them is desired. This is done mainly for IP over GRE, hence only tested for that. But anything else supported by flow dissection should work. v2: Use skb_flow_dissect_flow_keys() directly so that other tunneling can be supported through flow dissection (per Nikolay Aleksandrov). v3: Remove accidental inclusion of ports in the hash keys and clarify the documentation (Nikolay Alexandrov). Signed-off-by:

Stephen Suryaputra <ssuryaextr@gmail.com> Signed-off-by:

Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

Documentation/networking/ip-sysctl.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -80,6 +80,7 @@ fib_multipath_hash_policy - INTEGER
		Possible values:
		0 - Layer 3
		1 - Layer 4
		2 - Layer 3 or inner Layer 3 if present

		fib_sync_mem - UNSIGNED INTEGER
		Amount of dirty memory from fib entries that can be backlogged before

net/ipv4/route.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -1930,6 +1930,23 @@ int fib_multipath_hash(const struct net net, const struct flowi4 fl4,
		hash_keys.basic.ip_proto = fl4->flowi4_proto;
		}
		break;
		case 2:
		memset(&hash_keys, 0, sizeof(hash_keys));
		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
		/* skb is currently provided only when forwarding */
		if (skb) {
		struct flow_keys keys;

		skb_flow_dissect_flow_keys(skb, &keys, 0);

		hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
		hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
		} else {
		/* Same as case 0 */
		hash_keys.addrs.v4addrs.src = fl4->saddr;
		hash_keys.addrs.v4addrs.dst = fl4->daddr;
		}
		break;
		}
		mhash = flow_hash_from_keys(&hash_keys);

net/ipv4/sysctl_net_ipv4.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1008,7 +1008,7 @@ static struct ctl_table ipv4_net_table[] = {
		.mode = 0644,
		.proc_handler = proc_fib_multipath_hash_policy,
		.extra1 = &zero,
		.extra2 = &one,
		.extra2 = &two,
		},
		#endif
		{

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