[orchagent] Add value validation for RouteOrch, NhgOrch and Srv6Orch (#3596)

Add null checks for variable assignments in RouteOrch, NhgOrch and Srv6Orch. The assignments will only proceed if the string is not empty.

What I did
Add value validity checks to the assignment part of SET_COMMAND in the doTask methods for RouteOrch, NhgOrch and Srv6Orch, ensuring that the values assigned to fields are not empty.

Why I did it
For the value obtained by orchagent, assigning an empty value without validation may cause an issue.
So add a validity check before assigning the value.

Author: GaladrielZhao

orchagent/nhgorch.cpp

@@ -70,29 +70,28 @@ void NhgOrch::doTask(Consumer& consumer)
             /* Get group's next hop IPs and aliases */
             for (auto i : kfvFieldsValues(t))
             {
-                if (fvField(i) == "nexthop")
+                if (fvField(i) == "nexthop" && fvValue(i) != "")
                     ips = fvValue(i);
 
-                if (fvField(i) == "ifname")
+                if (fvField(i) == "ifname" && fvValue(i) != "")
                     aliases = fvValue(i);
 
-                if (fvField(i) == "weight")
+                if (fvField(i) == "weight" && fvValue(i) != "")
                     weights = fvValue(i);
 
-                if (fvField(i) == "mpls_nh")
+                if (fvField(i) == "mpls_nh" && fvValue(i) != "")
                     mpls_nhs = fvValue(i);
 
-                if (fvField(i) == "seg_src")
+                if (fvField(i) == "seg_src" && fvValue(i) != "")
                 {
                     srv6_source = fvValue(i);
                     srv6_nh = true;
                 }
 
-                if (fvField(i) == "nexthop_group")
+                if (fvField(i) == "nexthop_group" && fvValue(i) != "")
                 {
                     nhgs = fvValue(i);
-                    if (!nhgs.empty())
-                        is_recursive = true;
+                    is_recursive = true;
                 }
             }
             /* A NHG should not have both regular(ip/alias) and recursive fields */

orchagent/routeorch.cpp

@@ -742,58 +742,58 @@ void RouteOrch::doTask(Consumer& consumer)
 
                 for (auto i : kfvFieldsValues(t))
                 {
-                    if (fvField(i) == "nexthop")
+                    if (fvField(i) == "nexthop" && fvValue(i) != "")
                         ips = fvValue(i);
 
-                    if (fvField(i) == "ifname")
+                    if (fvField(i) == "ifname" && fvValue(i) != "")
                         aliases = fvValue(i);
 
-                    if (fvField(i) == "mpls_nh")
+                    if (fvField(i) == "mpls_nh" && fvValue(i) != "")
                         mpls_nhs = fvValue(i);
 
-                    if (fvField(i) == "vni_label") {
+                    if (fvField(i) == "vni_label" && fvValue(i) != "") {
                         vni_labels = fvValue(i);
                         overlay_nh = true;
                     }
 
-                    if (fvField(i) == "router_mac")
+                    if (fvField(i) == "router_mac" && fvValue(i) != "")
                         remote_macs = fvValue(i);
 
                     if (fvField(i) == "blackhole")
                         blackhole = fvValue(i) == "true";
 
-                    if (fvField(i) == "weight")
+                    if (fvField(i) == "weight" && fvValue(i) != "")
                         weights = fvValue(i);
 
-                    if (fvField(i) == "nexthop_group")
+                    if (fvField(i) == "nexthop_group" && fvValue(i) != "")
                         nhg_index = fvValue(i);
 
-                    if (fvField(i) == "segment") {
+                    if (fvField(i) == "segment" && fvValue(i) != "") {
                         srv6_segments = fvValue(i);
                         srv6_seg = true;
                         srv6_nh = true;
                     }
 
-                    if (fvField(i) == "seg_src") {
+                    if (fvField(i) == "seg_src" && fvValue(i) != "") {
                         srv6_source = fvValue(i);
                         srv6_nh = true;
                     }
 
-                    if (fvField(i) == "protocol")
+                    if (fvField(i) == "protocol" && fvValue(i) != "")
                     {
                         ctx.protocol = fvValue(i);
                     }
 
                     if (fvField(i) == "fallback_to_default_route")
                         fallback_to_default_route = fvValue(i) == "true";
 
-                    if (fvField(i) == "vpn_sid") {
+                    if (fvField(i) == "vpn_sid" && fvValue(i) != "") {
                         srv6_vpn_sids = fvValue(i);
                         srv6_nh = true;
                         srv6_vpn = true;
                     }
 
-                    if (fvField(i) == "pic_context_id")
+                    if (fvField(i) == "pic_context_id" && fvValue(i) != "")
                     {
                         context_index = fvValue(i);
                         srv6_vpn = true;

orchagent/srv6orch.cpp

@@ -2032,11 +2032,11 @@ task_process_status Srv6Orch::doTaskPicContextTable(const KeyOpFieldsValuesTuple
         pci.ref_count = 0;
         for (auto i : kfvFieldsValues(tuple))
         {
-            if (fvField(i) == "nexthop")
+            if (fvField(i) == "nexthop" && fvValue(i) != "")
             {
                 pci.nexthops = tokenize(fvValue(i), ',');
             }
-            else if (fvField(i) == "vpn_sid")
+            else if (fvField(i) == "vpn_sid" && fvValue(i) != "")
             {
                 pci.sids = tokenize(fvValue(i), ',');
             }