Igmpproxy currently doesn't support configurable query interval.
Add configuration option 'queryinterval' to set custom query interval
and also add configuration option 'reportforwarding' to enable/disable
forwarding IGMP membership reports upstream.

Reviewed on https://chromium-review.googlesource.com/2205180

---
diff -Naur --show-c-function a/src/config.c b/src/config.c
--- a/src/config.c	2020-05-15 23:37:48.036277661 -0700
+++ b/src/config.c	2020-05-15 23:33:38.045136599 -0700
@@ -87,6 +87,9 @@ static void initCommonConfig(void) {
     // aimwang: default value
     commonConfig.defaultInterfaceState = IF_STATE_DISABLED;
     commonConfig.rescanVif = 0;
+
+    // Default values for reportForwarding.
+    commonConfig.reportForwarding = 0;
 }
 
 /**
@@ -170,6 +173,26 @@ int loadConfig(char *configFile) {
 
             // Read next token...
             token = nextConfigToken();
+            continue;
+        }
+        else if(strcmp("queryinterval", token)==0) {
+            // Got a queryinterval token...
+            token = nextConfigToken();
+            my_log(LOG_DEBUG, 0, "Config: Got queryinterval token : %s", token);
+            commonConfig.queryInterval = atoi( token );
+            commonConfig.startupQueryInterval = (commonConfig.queryInterval / 4);
+
+            // Read next token...
+            token = nextConfigToken();
+            continue;
+        }
+        else if(strcmp("reportforwarding", token)==0) {
+            // Got a reportforwarding token...
+            my_log(LOG_DEBUG, 0, "Config: Need to forward membership reports.");
+            commonConfig.reportForwarding = 1;
+
+            // Read next token...
+            token = nextConfigToken();
             continue;
         } else {
             // Unparsable token... Exit...
diff -Naur --show-c-function a/src/igmpproxy.h b/src/igmpproxy.h
--- a/src/igmpproxy.h	2020-05-15 23:38:08.544207561 -0700
+++ b/src/igmpproxy.h	2020-05-15 23:29:40.149962872 -0700
@@ -177,6 +177,8 @@ struct Config {
     // Set if not detect new interface for down stream.
     unsigned short	defaultInterfaceState;	// 0: disable, 2: downstream
     //~ aimwang added done
+    // Set if need to forward membership reports
+    unsigned short      reportForwarding;
 };
 
 // Holds the indeces of the upstream IF...
diff -Naur --show-c-function a/src/rttable.c b/src/rttable.c
--- a/src/rttable.c	2020-05-15 23:38:27.012144473 -0700
+++ b/src/rttable.c	2020-05-15 23:36:32.340536868 -0700
@@ -391,8 +391,10 @@ int insertRoute(uint32_t group, int ifx)
         // Send Join request upstream
         sendJoinLeaveUpstream(croute, 1);
     } else {
+      if(conf->reportForwarding) {
         // Send Report upstream
         sendReportUpstream(group);
+      }
     }
 
     logRouteTable("Insert Route");