lib: Move l4 flow hash to the flow library.

This commit moves hash_symmetric_l4() to the flow library so that
it may be used in future patches.

3 files changed, 39 insertions, 37 deletions

diff --git a/lib/flow.c b/lib/flow.c
index 87ca0f282..6842d3b5a 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -461,3 +461,40 @@ flow_wildcards_set_reg_mask(struct flow_wildcards *wc, int idx, uint32_t mask)
 {
     wc->reg_masks[idx] = mask;
 }
+
+/* Hashes 'flow' based on its L2 through L4 protocol information. */
+uint32_t
+flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis)
+{
+    struct {
+        ovs_be32 ip_addr;
+        ovs_be16 eth_type;
+        ovs_be16 vlan_tci;
+        ovs_be16 tp_addr;
+        uint8_t eth_addr[ETH_ADDR_LEN];
+        uint8_t ip_proto;
+    } fields;
+
+    int i;
+
+    memset(&fields, 0, sizeof fields);
+    for (i = 0; i < ETH_ADDR_LEN; i++) {
+        fields.eth_addr[i] = flow->dl_src[i] ^ flow->dl_dst[i];
+    }
+    fields.vlan_tci = flow->vlan_tci & htons(VLAN_VID_MASK);
+    fields.eth_type = flow->dl_type;
+    if (fields.eth_type == htons(ETH_TYPE_IP)) {
+        fields.ip_addr = flow->nw_src ^ flow->nw_dst;
+        fields.ip_proto = flow->nw_proto;
+        if (fields.ip_proto == IP_TYPE_TCP || fields.ip_proto == IP_TYPE_UDP) {
+            fields.tp_addr = flow->tp_src ^ flow->tp_dst;
+        } else {
+            fields.tp_addr = htons(0);
+        }
+    } else {
+        fields.ip_addr = htonl(0);
+        fields.ip_proto = 0;
+        fields.tp_addr = htons(0);
+    }
+    return hash_bytes(&fields, sizeof fields, basis);
+}
diff --git a/lib/flow.h b/lib/flow.h
index 54f28d583..2dd0c4aec 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -150,5 +150,6 @@ bool flow_wildcards_has_extra(const struct flow_wildcards *,
 uint32_t flow_wildcards_hash(const struct flow_wildcards *);
 bool flow_wildcards_equal(const struct flow_wildcards *,
                           const struct flow_wildcards *);
+uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
 
 #endif /* flow.h */
diff --git a/lib/multipath.c b/lib/multipath.c
index 83df6805d..19e7b3610 100644
--- a/lib/multipath.c
+++ b/lib/multipath.c
@@ -87,42 +87,6 @@ multipath_execute(const struct nx_action_multipath *mp, struct flow *flow)
 }
 
 static uint32_t
-hash_symmetric_l4(const struct flow *flow, uint16_t basis)
-{
-    struct {
-        ovs_be32 ip_addr;
-        ovs_be16 eth_type;
-        ovs_be16 vlan_tci;
-        ovs_be16 tp_addr;
-        uint8_t eth_addr[ETH_ADDR_LEN];
-        uint8_t ip_proto;
-    } fields;
-
-    int i;
-
-    memset(&fields, 0, sizeof fields);
-    for (i = 0; i < ETH_ADDR_LEN; i++) {
-        fields.eth_addr[i] = flow->dl_src[i] ^ flow->dl_dst[i];
-    }
-    fields.vlan_tci = flow->vlan_tci & htons(VLAN_VID_MASK);
-    fields.eth_type = flow->dl_type;
-    if (fields.eth_type == htons(ETH_TYPE_IP)) {
-        fields.ip_addr = flow->nw_src ^ flow->nw_dst;
-        fields.ip_proto = flow->nw_proto;
-        if (fields.ip_proto == IP_TYPE_TCP || fields.ip_proto == IP_TYPE_UDP) {
-            fields.tp_addr = flow->tp_src ^ flow->tp_dst;
-        } else {
-            fields.tp_addr = htons(0);
-        }
-    } else {
-        fields.ip_addr = htonl(0);
-        fields.ip_proto = 0;
-        fields.tp_addr = htons(0);
-    }
-    return hash_bytes(&fields, sizeof fields, basis);
-}
-
-static uint32_t
 multipath_hash(const struct flow *flow, enum nx_mp_fields fields,
                uint16_t basis)
 {
@@ -131,7 +95,7 @@ multipath_hash(const struct flow *flow, enum nx_mp_fields fields,
         return hash_bytes(flow->dl_src, sizeof flow->dl_src, basis);
 
     case NX_MP_FIELDS_SYMMETRIC_L4:
-        return hash_symmetric_l4(flow, basis);
+        return flow_hash_symmetric_l4(flow, basis);
     }
 
     NOT_REACHED();