Some operators prefer IPv6 path selection to use a standard 5-tuple
hash rather than just an L3 hash with the flow the label. To that end
add support to IPv6 for multipath hash policy similar to bf4e0a3db97eb
("net: ipv4: add support for ECMP hash policy choice"). The default
is still L3 which covers source and destination addresses along with
flow label and IPv6 protocol.
Signed-off-by: David Ahern <dsah...@gmail.com>
---
Documentation/networking/ip-sysctl.txt | 7 ++++
include/net/ip6_route.h | 3 +-
include/net/netevent.h | 1 +
include/net/netns/ipv6.h | 1 +
net/ipv6/icmp.c | 2 +-
net/ipv6/route.c | 64 ++++++++++++++++++++++++++--------
net/ipv6/sysctl_net_ipv6.c | 26 ++++++++++++++
7 files changed, 87 insertions(+), 17 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.txt
b/Documentation/networking/ip-sysctl.txt
index a553d4e4a0fb..783675a730e5 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1363,6 +1363,13 @@ flowlabel_reflect - BOOLEAN
FALSE: disabled
Default: FALSE
+fib_multipath_hash_policy - INTEGER
+ Controls which hash policy to use for multipath routes.
+ Default: 0 (Layer 3)
+ Possible values:
+ 0 - Layer 3 (source and destination addresses plus flow label)
+ 1 - Layer 4 (standard 5-tuple)
+
anycast_src_echo_reply - BOOLEAN
Controls the use of anycast addresses as source addresses for ICMPv6
echo reply
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 27d23a65f3cd..f13657a62e5c 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -127,7 +127,8 @@ static inline int ip6_route_get_saddr(struct net *net,
struct rt6_info *rt,
struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
const struct in6_addr *saddr, int oif, int flags);
-u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb);
+u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
+ const struct sk_buff *skb);
struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
diff --git a/include/net/netevent.h b/include/net/netevent.h
index baee605a94ab..d9918261701c 100644
--- a/include/net/netevent.h
+++ b/include/net/netevent.h
@@ -27,6 +27,7 @@ enum netevent_notif_type {
NETEVENT_REDIRECT, /* arg is struct netevent_redirect ptr */
NETEVENT_DELAY_PROBE_TIME_UPDATE, /* arg is struct neigh_parms ptr */
NETEVENT_IPV4_MPATH_HASH_UPDATE, /* arg is struct net ptr */
+ NETEVENT_IPV6_MPATH_HASH_UPDATE, /* arg is struct net ptr */
};
int register_netevent_notifier(struct notifier_block *nb);
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 987cc4569cb8..6b0de3b71bbf 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -28,6 +28,7 @@ struct netns_sysctl_ipv6 {
int ip6_rt_gc_elasticity;
int ip6_rt_mtu_expires;
int ip6_rt_min_advmss;
+ int multipath_hash_policy;
int flowlabel_consistency;
int auto_flowlabels;
int icmpv6_time;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 4fa4f1b150a4..f53c14390d9f 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -522,7 +522,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8
code, __u32 info,
fl6.fl6_icmp_type = type;
fl6.fl6_icmp_code = code;
fl6.flowi6_uid = sock_net_uid(net, NULL);
- fl6.mp_hash = rt6_multipath_hash(&fl6, skb);
+ fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb);
security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
sk = icmpv6_xmit_lock(net);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ab0de69ec67d..5c4481e4f3e1 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -450,7 +450,8 @@ static bool rt6_check_expired(const struct rt6_info *rt)
return false;
}
-static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
+static struct rt6_info *rt6_multipath_select(const struct net *net,
+ struct rt6_info *match,
struct flowi6 *fl6, int oif,
int strict)
{
@@ -460,7 +461,7 @@ static struct rt6_info *rt6_multipath_select(struct
rt6_info *match,
* case it will always be non-zero. Otherwise now is the time to do it.
*/
if (!fl6->mp_hash)
- fl6->mp_hash = rt6_multipath_hash(fl6, NULL);
+ fl6->mp_hash = rt6_multipath_hash(net, fl6, NULL);
if (fl6->mp_hash <= atomic_read(&match->rt6i_nh_upper_bound))
return match;
@@ -929,7 +930,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net
*net,
rt = rt6_device_match(net, rt, &fl6->saddr,
fl6->flowi6_oif, flags);
if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
- rt = rt6_multipath_select(rt, fl6,
+ rt = rt6_multipath_select(net, rt, fl6,
fl6->flowi6_oif, flags);
}
if (rt == net->ipv6.ip6_null_entry) {
@@ -1669,7 +1670,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct
fib6_table *table,
redo_rt6_select:
rt = rt6_select(net, fn, oif, strict);
if (rt->rt6i_nsiblings)
- rt = rt6_multipath_select(rt, fl6, oif, strict);
+ rt = rt6_multipath_select(net, rt, fl6, oif, strict);
if (rt == net->ipv6.ip6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
@@ -1819,20 +1820,53 @@ static void ip6_multipath_l3_keys(const struct sk_buff
*skb,
}
/* if skb is set it will be used and fl6 can be NULL */
-u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb)
+u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
+ const struct sk_buff *skb)
{
struct flow_keys hash_keys;
u32 mhash;
- memset(&hash_keys, 0, sizeof(hash_keys));
- hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
- if (skb) {
- ip6_multipath_l3_keys(skb, &hash_keys);
- } else {
- hash_keys.addrs.v6addrs.src = fl6->saddr;
- hash_keys.addrs.v6addrs.dst = fl6->daddr;
- hash_keys.tags.flow_label = (__force u32)fl6->flowlabel;
- hash_keys.basic.ip_proto = fl6->flowi6_proto;
+ switch (net->ipv6.sysctl.multipath_hash_policy) {
+ case 0:
+ memset(&hash_keys, 0, sizeof(hash_keys));
+ hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+ if (skb) {
+ ip6_multipath_l3_keys(skb, &hash_keys);
+ } else {
+ hash_keys.addrs.v6addrs.src = fl6->saddr;
+ hash_keys.addrs.v6addrs.dst = fl6->daddr;
+ hash_keys.tags.flow_label = (__force u32)fl6->flowlabel;
+ hash_keys.basic.ip_proto = fl6->flowi6_proto;
+ }
+ break;
+ case 1:
+ if (skb) {
+ unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
+ struct flow_keys keys;
+
+ /* short-circuit if we already have L4 hash present */
+ if (skb->l4_hash)
+ return skb_get_hash_raw(skb) >> 1;
+
+ memset(&hash_keys, 0, sizeof(hash_keys));
+
+ skb_flow_dissect_flow_keys(skb, &keys, flag);
+
+ hash_keys.control.addr_type =
FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+ hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
+ hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
+ hash_keys.ports.src = keys.ports.src;
+ hash_keys.ports.dst = keys.ports.dst;
+ hash_keys.basic.ip_proto = keys.basic.ip_proto;
+ } else {
+ memset(&hash_keys, 0, sizeof(hash_keys));
+ hash_keys.control.addr_type =
FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+ hash_keys.addrs.v6addrs.src = fl6->saddr;
+ hash_keys.addrs.v6addrs.dst = fl6->daddr;
+ hash_keys.ports.src = fl6->fl6_sport;
+ hash_keys.ports.dst = fl6->fl6_dport;
+ hash_keys.basic.ip_proto = fl6->flowi6_proto;
+ }
}
mhash = flow_hash_from_keys(&hash_keys);
@@ -1858,7 +1892,7 @@ void ip6_route_input(struct sk_buff *skb)
if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
- fl6.mp_hash = rt6_multipath_hash(&fl6, skb);
+ fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb);
skb_dst_drop(skb);
skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
}
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index 262f791f1b9b..6125accc993a 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -16,14 +16,31 @@
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/inet_frag.h>
+#include <net/netevent.h>
#ifdef CONFIG_NETLABEL
#include <net/calipso.h>
#endif
+static int zero;
static int one = 1;
static int auto_flowlabels_min;
static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX;
+static int proc_rt6_multipath_hash_policy(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ struct net *net;
+ int ret;
+
+ net = container_of(table->data, struct net,
+ ipv6.sysctl.multipath_hash_policy);
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (write && ret == 0)
+ call_netevent_notifiers(NETEVENT_IPV6_MPATH_HASH_UPDATE, net);
+
+ return ret;
+}
static struct ctl_table ipv6_table_template[] = {
{
@@ -126,6 +143,15 @@ static struct ctl_table ipv6_table_template[] = {
.mode = 0644,
.proc_handler = proc_dointvec
},
+ {
+ .procname = "fib_multipath_hash_policy",
+ .data = &init_net.ipv6.sysctl.multipath_hash_policy,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_rt6_multipath_hash_policy,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
{ }
};
--
2.11.0
