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List: openvswitch-dev
Subject: [ovs-dev] Hashing: Add truly symmetric L3+L4 fields option for multipath and bundle hashing
From: jvb127 () gmail ! com (Jeroen van Bemmel)
Date: 2015-06-28 18:43:20
Message-ID: CAOpSVYrGCC4ud1oxKY+8TPeL3y9jph-jgUkMJ5W9UN7BrBpzEw () mail ! gmail ! com
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The symmetric_l4 function implements a hash over various fields
including L2 fields such as ethernet source and destination MAC.
Inspite of its name, there are situations in which this hash does not
yield symmetric results ( e.g. when using VRRP, where the router
receives packets on a virtual MAC but responds from its physical MAC )
This patch adds a new 'symmetric_l3l4' function which is mostly an
intelligent copy&paste of existing code. It includes only L3 and L4
fields, including UDP and SCTP ports
I updated the documentation references that I could find, and tried
copying some of the symmetric_l3 test cases. However, 'make check'
wasn't working for me even without these patches, so I left out those
changes
Signed-off-by:Jeroen van Bemmel <jvb127 at gmail.com>
Suggested-by: Benn Pfaff <blp at nicira.com>
diff --git a/include/openflow/nicira-ext.h b/include/openflow/nicira-ext.h
index 22325aa..225708b 100644
--- a/include/openflow/nicira-ext.h
+++ b/include/openflow/nicira-ext.h
@@ -109,7 +109,17 @@ enum nx_hash_fields {
* - NXM_OF_IP_SRC / NXM_OF_IP_DST
* - NXM_OF_TCP_SRC / NXM_OF_TCP_DST
*/
- NX_HASH_FIELDS_SYMMETRIC_L4
+ NX_HASH_FIELDS_SYMMETRIC_L4,
+
+ /* L3+L4 only, including UDP ports:
+ *
+ * - NXM_OF_IP_PROTO
+ * - NXM_OF_IP_SRC / NXM_OF_IP_DST
+ * - NXM_OF_TCP_SRC / NXM_OF_TCP_DST
+ * - NXM_OF_UDP_SRC / NXM_OF_UDP_DST
+ * - NXM_OF_SCTP_SRC / NXM_OF_SCTP_DST
+ */
+ NX_HASH_FIELDS_SYMMETRIC_L3L4
};
/* This command enables or disables an Open vSwitch extension that allows a
diff --git a/lib/bundle.c b/lib/bundle.c
index ee8079c..2d820b8 100644
--- a/lib/bundle.c
+++ b/lib/bundle.c
@@ -186,6 +186,8 @@ bundle_parse__(const char *s, char **save_ptr,
bundle->fields = NX_HASH_FIELDS_ETH_SRC;
} else if (!strcasecmp(fields, "symmetric_l4")) {
bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L4;
+ } else if (!strcasecmp(fields, "symmetric_l3l4")) {
+ bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L3L4;
} else {
return xasprintf("%s: unknown fields `%s'", s, fields);
}
diff --git a/lib/flow.c b/lib/flow.c
index 6bfe738..1edcb53 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -1347,6 +1347,47 @@ flow_hash_symmetric_l4(const struct flow *flow,
uint32_t basis)
return jhash_bytes(&fields, sizeof fields, basis);
}
+/* Hashes 'flow' based on its L3 through L4 protocol information. */
+uint32_t
+flow_hash_symmetric_l3l4(const struct flow *flow, uint32_t basis)
+{
+ struct {
+ union {
+ ovs_be32 ipv4_addr;
+ struct in6_addr ipv6_addr;
+ };
+ ovs_be16 tp_port;
+ uint8_t ip_proto;
+ } fields;
+
+ int i;
+
+ memset(&fields, 0, sizeof fields);
+
+ /* UDP source and destination port are also taken into account */
+ if ( flow->dl_type == htons(ETH_TYPE_IP)) {
+ fields.ipv4_addr = flow->nw_src ^ flow->nw_dst;
+ fields.ip_proto = flow->nw_proto;
+ if (fields.ip_proto == IPPROTO_TCP || fields.ip_proto ==
IPPROTO_UDP || fields.ip_proto == IPPROTO_SCTP) {
+ fields.tp_port = flow->tp_src ^ flow->tp_dst;
+ }
+ } else if ( flow->dl_type == htons(ETH_TYPE_IPV6)) {
+ const uint8_t *a = &flow->ipv6_src.s6_addr[0];
+ const uint8_t *b = &flow->ipv6_dst.s6_addr[0];
+ uint8_t *ipv6_addr = &fields.ipv6_addr.s6_addr[0];
+
+ for (i=0; i<16; i++) {
+ ipv6_addr[i] = a[i] ^ b[i];
+ }
+ fields.ip_proto = flow->nw_proto;
+ if (fields.ip_proto == IPPROTO_TCP || fields.ip_proto ==
IPPROTO_UDP || fields.ip_proto == IPPROTO_SCTP) {
+ fields.tp_port = flow->tp_src ^ flow->tp_dst;
+ }
+ }
+ // Would be nice to use murmur hashing here...
+ return jhash_bytes(&fields, sizeof fields, basis);
+}
+
/* Initialize a flow with random fields that matter for nx_hash_fields. */
void
flow_random_hash_fields(struct flow *flow)
@@ -1414,6 +1455,23 @@ flow_mask_hash_fields(const struct flow *flow,
struct flow_wildcards *wc,
wc->masks.vlan_tci |= htons(VLAN_VID_MASK | VLAN_CFI);
break;
+ case NX_HASH_FIELDS_SYMMETRIC_L3L4:
+ if (flow->dl_type == htons(ETH_TYPE_IP)) {
+ memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
+ memset(&wc->masks.nw_dst, 0xff, sizeof wc->masks.nw_dst);
+ } else if (flow->dl_type == htons(ETH_TYPE_IPV6)) {
+ memset(&wc->masks.ipv6_src, 0xff, sizeof wc->masks.ipv6_src);
+ memset(&wc->masks.ipv6_dst, 0xff, sizeof wc->masks.ipv6_dst);
+ }
+ if (is_ip_any(flow)) {
+ memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
+ if (( flow->nw_proto == IPPROTO_TCP )||(
flow->nw_proto == IPPROTO_UDP )||( flow->nw_proto == IPPROTO_SCTP )) {
+ memset(&wc->masks.tp_src, 0xff, sizeof wc->masks.tp_src);
+ memset(&wc->masks.tp_dst, 0xff, sizeof wc->masks.tp_dst);
+ }
+ }
+ break;
+
default:
OVS_NOT_REACHED();
}
@@ -1431,6 +1489,9 @@ flow_hash_fields(const struct flow *flow, enum
nx_hash_fields fields,
case NX_HASH_FIELDS_SYMMETRIC_L4:
return flow_hash_symmetric_l4(flow, basis);
+
+ case NX_HASH_FIELDS_SYMMETRIC_L3L4:
+ return flow_hash_symmetric_l3l4(flow, basis);
}
OVS_NOT_REACHED();
@@ -1443,6 +1504,7 @@ flow_hash_fields_to_str(enum nx_hash_fields fields)
switch (fields) {
case NX_HASH_FIELDS_ETH_SRC: return "eth_src";
case NX_HASH_FIELDS_SYMMETRIC_L4: return "symmetric_l4";
+ case NX_HASH_FIELDS_SYMMETRIC_L3L4: return "symmetric_l3l4";
default: return "<unknown>";
}
}
@@ -1452,7 +1514,8 @@ bool
flow_hash_fields_valid(enum nx_hash_fields fields)
{
return fields == NX_HASH_FIELDS_ETH_SRC
- || fields == NX_HASH_FIELDS_SYMMETRIC_L4;
+ || fields == NX_HASH_FIELDS_SYMMETRIC_L4
+ || fields == NX_HASH_FIELDS_SYMMETRIC_L3L4;
}
/* Returns a hash value for the bits of 'flow' that are active based on
diff --git a/lib/flow.h b/lib/flow.h
index 384a031..856dfd0 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -341,6 +341,7 @@ bool flow_wildcards_equal(const struct flow_wildcards *,
const struct flow_wildcards *);
uint32_t flow_hash_5tuple(const struct flow *flow, uint32_t basis);
uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
+uint32_t flow_hash_symmetric_l3l4(const struct flow *flow, uint32_t basis);
/* Initialize a flow with random fields that matter for nx_hash_fields. */
void flow_random_hash_fields(struct flow *);
diff --git a/lib/multipath.c b/lib/multipath.c
index 355ef4b..8eefb41 100644
--- a/lib/multipath.c
+++ b/lib/multipath.c
@@ -162,6 +162,8 @@ multipath_parse__(struct ofpact_multipath *mp,
const char *s_, char *s)
mp->fields = NX_HASH_FIELDS_ETH_SRC;
} else if (!strcasecmp(fields, "symmetric_l4")) {
mp->fields = NX_HASH_FIELDS_SYMMETRIC_L4;
+ } else if (!strcasecmp(fields, "symmetric_l3l4")) {
+ mp->fields = NX_HASH_FIELDS_SYMMETRIC_L3L4;
} else {
return xasprintf("%s: unknown fields `%s'", s_, fields);
}
diff --git a/utilities/ovs-ofctl.8.in b/utilities/ovs-ofctl.8.in
index 395d851..d484f26 100644
--- a/utilities/ovs-ofctl.8.in
+++ b/utilities/ovs-ofctl.8.in
@@ -1607,8 +1607,8 @@ numbered 0 through \fIn_links\fR minus 1, and
stores the link into
\fIdst\fB[\fIstart\fB..\fIend\fB]\fR, which must be an NXM field as
described above.
.IP
-Currently, \fIfields\fR must be either \fBeth_src\fR or
-\fBsymmetric_l4\fR and \fIalgorithm\fR must be one of \fBmodulo_n\fR,
+Currently, \fIfields\fR must be either \fBeth_src\fR, \fBsymmetric_l4\fR or
+\fBsymmetric_l3l4\fR and \fIalgorithm\fR must be one of \fBmodulo_n\fR,
\fBhash_threshold\fR, \fBhrw\fR, and \fBiter_hash\fR. Only
the \fBiter_hash\fR algorithm uses \fIarg\fR.
.IP
@@ -1621,7 +1621,7 @@ slaves represented as \fIslave_type\fR.
Currently the only supported
\fIslave_type\fR is \fBofport\fR. Thus, each \fIs1\fR through \fIsN\fR should
be an OpenFlow port number. Outputs to the selected slave.
.IP
-Currently, \fIfields\fR must be either \fBeth_src\fR or \fBsymmetric_l4\fR and
+Currently, \fIfields\fR must be either \fBeth_src\fR,
\fBsymmetric_l4\fR or \fBsymmetric_l3l4\fR and
\fIalgorithm\fR must be one of \fBhrw\fR and \fBactive_backup\fR.
.IP
Example: \fBbundle(eth_src,0,hrw,ofport,slaves:4,8)\fR uses an Ethernet source
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