[nhg]: Add support for weight in nexthop group member. (#1752)

* Add support for weight in nexthop group member.
1. In fpmsyncd, parse weight field in nlmsg, set APP_DB if weight is set.
2. In routeorch, collect weight and pass weight attribute to next hop group memeber object.

Signed-off-by: Zhenghui Cai <zcai@juniper.net>

fpmsyncd/routesync.cpp

@@ -700,6 +700,7 @@ void RouteSync::onRouteMsg(int nlmsg_type, struct nl_object *obj, char *vrf)
     /* Get nexthop lists */
     string nexthops = getNextHopGw(route_obj);
     string ifnames = getNextHopIf(route_obj);
+    string weights = getNextHopWt(route_obj);
 
     vector<string> alsv = tokenize(ifnames, ',');
     for (auto alias : alsv)
@@ -722,6 +723,11 @@ void RouteSync::onRouteMsg(int nlmsg_type, struct nl_object *obj, char *vrf)
 
     fvVector.push_back(nh);
     fvVector.push_back(idx);
+    if (!weights.empty())
+    {
+        FieldValueTuple wt("weight", weights);
+        fvVector.push_back(wt);
+    }
 
     if (!warmRestartInProgress)
     {
@@ -962,3 +968,36 @@ string RouteSync::getNextHopIf(struct rtnl_route *route_obj)
 
     return result;
 }
+
+/*
+ * Get next hop weights
+ * @arg route_obj     route object
+ *
+ * Return concatenation of interface names: wt0 + "," + wt1 + .... + "," + wtN
+ */
+string RouteSync::getNextHopWt(struct rtnl_route *route_obj)
+{
+    string result = "";
+
+    for (int i = 0; i < rtnl_route_get_nnexthops(route_obj); i++)
+    {
+        struct rtnl_nexthop *nexthop = rtnl_route_nexthop_n(route_obj, i);
+        /* Get the weight of next hop */
+        uint8_t weight = rtnl_route_nh_get_weight(nexthop);
+        if (weight)
+        {
+            result += to_string(weight + 1);
+        }
+        else
+        {
+            return "";
+        }
+
+        if (i + 1 < rtnl_route_get_nnexthops(route_obj))
+        {
+            result += string(",");
+        }
+    }
+
+    return result;
+}

fpmsyncd/routesync.h

@@ -75,6 +75,9 @@ class RouteSync : public NetMsg
 
     /* Get next hop interfaces */
     string getNextHopIf(struct rtnl_route *route_obj);
+
+    /* Get next hop weights*/
+    string getNextHopWt(struct rtnl_route *route_obj);
 };
 
 }

orchagent/nexthopgroupkey.h

@@ -31,6 +31,21 @@ class NextHopGroupKey
         }
     }
 
+    NextHopGroupKey(const std::string &nexthops, const std::string &weights)
+    {
+        std::vector<std::string> nhv = tokenize(nexthops, NHG_DELIMITER);
+        std::vector<std::string> wtv = tokenize(weights, NHG_DELIMITER);
+        for (uint32_t i = 0; i < nhv.size(); i++)
+        {
+            NextHopKey nh(nhv[i]);
+            if (i < wtv.size())
+            {
+                nh.weight = (uint32_t)std::stoi(wtv[i]);
+            }
+            m_nexthops.insert(nh);
+        }
+    }
+
     inline const std::set<NextHopKey> &getNextHops() const
     {
         return m_nexthops;

orchagent/nexthopkey.h

@@ -15,10 +15,12 @@ struct NextHopKey
     string              alias;          // incoming interface alias
     uint32_t            vni;            // Encap VNI overlay nexthop
     MacAddress          mac_address;    // Overlay Nexthop MAC.
+    uint32_t            weight;         // NH weight for NHGs
 
-    NextHopKey() = default;
-    NextHopKey(const std::string &ipstr, const std::string &alias) : ip_address(ipstr), alias(alias), vni(0), mac_address() {}
-    NextHopKey(const IpAddress &ip, const std::string &alias) : ip_address(ip), alias(alias), vni(0), mac_address() {}
+
+    NextHopKey() : weight(0) {}
+    NextHopKey(const std::string &ipstr, const std::string &alias) : ip_address(ipstr), alias(alias), vni(0), mac_address(), weight(0) {}
+    NextHopKey(const IpAddress &ip, const std::string &alias) : ip_address(ip), alias(alias), vni(0), mac_address(), weight(0) {}
     NextHopKey(const std::string &str)
     {
         if (str.find(NHG_DELIMITER) != string::npos)

orchagent/routeorch.cpp

@@ -325,6 +325,13 @@ bool RouteOrch::validnexthopinNextHopGroup(const NextHopKey &nexthop, uint32_t&
         nhgm_attr.value.oid = m_neighOrch->getNextHopId(nexthop);
         nhgm_attrs.push_back(nhgm_attr);
 
+        if (nexthop.weight)
+        {
+            nhgm_attr.id = SAI_NEXT_HOP_GROUP_MEMBER_ATTR_WEIGHT;
+            nhgm_attr.value.s32 = nexthop.weight;
+            nhgm_attrs.push_back(nhgm_attr);
+        }
+
         status = sai_next_hop_group_api->create_next_hop_group_member(&nexthop_id, gSwitchId,
                                                                       (uint32_t)nhgm_attrs.size(),
                                                                       nhgm_attrs.data());
@@ -513,6 +520,7 @@ void RouteOrch::doTask(Consumer& consumer)
                 string aliases;
                 string vni_labels;
                 string remote_macs;
+                string weights;
                 bool& excp_intfs_flag = ctx.excp_intfs_flag;
                 bool overlay_nh = false;
                 bool blackhole = false;
@@ -535,6 +543,9 @@ void RouteOrch::doTask(Consumer& consumer)
 
                     if (fvField(i) == "blackhole")
                         blackhole = fvValue(i) == "true";
+
+                    if (fvField(i) == "weight")
+                        weights = fvValue(i);
                 }
 
                 vector<string>& ipv = ctx.ipv;
@@ -624,7 +635,7 @@ void RouteOrch::doTask(Consumer& consumer)
                         nhg_str += NHG_DELIMITER + ipv[i] + NH_DELIMITER + alsv[i];
                     }
 
-                    nhg = NextHopGroupKey(nhg_str);
+                    nhg = NextHopGroupKey(nhg_str, weights);
 
                 }
                 else
@@ -1102,6 +1113,7 @@ bool RouteOrch::addNextHopGroup(const NextHopGroupKey &nexthops)
     for (size_t i = 0; i < npid_count; i++)
     {
         auto nhid = next_hop_ids[i];
+        auto weight = nhopgroup_members_set[nhid].weight;
 
         // Create a next hop group member
         vector<sai_attribute_t> nhgm_attrs;
@@ -1115,6 +1127,13 @@ bool RouteOrch::addNextHopGroup(const NextHopGroupKey &nexthops)
         nhgm_attr.value.oid = nhid;
         nhgm_attrs.push_back(nhgm_attr);
 
+        if (weight)
+        {
+            nhgm_attr.id = SAI_NEXT_HOP_GROUP_MEMBER_ATTR_WEIGHT;
+            nhgm_attr.value.s32 = weight;
+            nhgm_attrs.push_back(nhgm_attr);
+        }
+
         gNextHopGroupMemberBulker.create_entry(&nhgm_ids[i],
                                                  (uint32_t)nhgm_attrs.size(),
                                                  nhgm_attrs.data());

tests/test_nhg.py

@@ -44,7 +44,9 @@ def test_route_nhg(self, dvs, dvs_route, testlog):
 
         dvs_route.check_asicdb_deleted_route_entries([rtprefix])
 
-        fvs = swsscommon.FieldValuePairs([("nexthop","10.0.0.1,10.0.0.3,10.0.0.5"), ("ifname", "Ethernet0,Ethernet4,Ethernet8")])
+        fvs = swsscommon.FieldValuePairs([("nexthop","10.0.0.1,10.0.0.3,10.0.0.5"),
+                                          ("ifname", "Ethernet0,Ethernet4,Ethernet8"),
+                                          ("weight", "10,30,50")])
         ps.set(rtprefix, fvs)
 
         # check if route was propagated to ASIC DB
@@ -68,6 +70,16 @@ def test_route_nhg(self, dvs, dvs_route, testlog):
 
             assert fvs["SAI_NEXT_HOP_GROUP_MEMBER_ATTR_NEXT_HOP_GROUP_ID"] == nhgid
 
+            # verify weight attributes in asic db
+            nhid = fvs["SAI_NEXT_HOP_GROUP_MEMBER_ATTR_NEXT_HOP_ID"]
+            weight = fvs["SAI_NEXT_HOP_GROUP_MEMBER_ATTR_WEIGHT"]
+
+            fvs = asic_db.get_entry("ASIC_STATE:SAI_OBJECT_TYPE_NEXT_HOP", nhid)
+            nhip = fvs["SAI_NEXT_HOP_ATTR_IP"].split('.')
+            expected_weight = int(nhip[3]) * 10
+
+            assert int(weight) == expected_weight
+
         # bring links down one-by-one
         for i in [0, 1, 2]:
             dvs.servers[i].runcmd("ip link set down dev eth0") == 0