Squashed commit of the following:

The MLD implementation did not follow the RFC correctly when it is the Querier.  The Querier should use a general query and get query messages from all members of all groups.  This would be driven by a single timer per sub-nset since all groups are queried at once. Instead, the design used a Multicast Address Specific Query with one timer per group and ignores groups that we are not members of.

    Similary, the MLDv1 compatibility timer should be a single, separate timer, not a per-group timer.

    net/mld: Group may be NULL when sending a general query

net/mld/mld.h

@@ -123,35 +123,45 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* Group flags */
+/* Global flags */
 
 #define MLD_QUERIER              (1 << 0)  /* Querier */
+#define MLD_V1COMPAT             (1 << 1)  /* MLDv1 compatibility mode */
+#define MLD_GENPEND              (1 << 2)  /* General query pending */
+
+#define SET_MLD_QUERIER(f)       do { (f) |= MLD_QUERIER; } while (0)
+#define SET_MLD_V1COMPAT(f)      do { (f) |= MLD_V1COMPAT; } while (0)
+#define SET_MLD_GENPEND(f)       do { (f) |= MLD_GENPEND; } while (0)
+
+#define CLR_MLD_QUERIER(f)       do { (f) &= ~MLD_QUERIER; } while (0)
+#define CLR_MLD_V1COMPAT(f)      do { (f) &= ~MLD_V1COMPAT; } while (0)
+#define CLR_MLD_GENPEND(f)       do { (f) &= ~MLD_GENPEND; } while (0)
+
+#define IS_MLD_QUERIER(f)        (((f) & MLD_QUERIER) != 0)
+#define IS_MLD_V1COMPAT(f)       (((f) & MLD_V1COMPAT) != 0)
+#define IS_MLD_GENPEND(f)        (((f) & MLD_GENPEND) != 0)
+
+/* Group flags */
+
 #define MLD_STARTUP              (1 << 1)  /* Startup unsolicited Reports */
-#define MLD_V1COMPAT             (1 << 2)  /* Version 1 compatibility mode */
 #define MLD_LASTREPORT           (1 << 3)  /* We were the last to report */
 #define MLD_SCHEDMSG             (1 << 4)  /* Outgoing message scheduled */
 #define MLD_WAITMSG              (1 << 5)  /* Block until message sent */
 #define MLD_RPTPEND              (1 << 6)  /* Report pending */
 
-#define SET_MLD_QUERIER(f)       do { (f) |= MLD_QUERIER; } while (0)
 #define SET_MLD_STARTUP(f)       do { (f) |= MLD_STARTUP; } while (0)
-#define SET_MLD_V1COMPAT(f)      do { (f) |= MLD_V1COMPAT; } while (0)
 #define SET_MLD_LASTREPORT(f)    do { (f) |= MLD_LASTREPORT; } while (0)
 #define SET_MLD_SCHEDMSG(f)      do { (f) |= MLD_SCHEDMSG; } while (0)
 #define SET_MLD_WAITMSG(f)       do { (f) |= MLD_WAITMSG; } while (0)
 #define SET_MLD_RPTPEND(f)       do { (f) |= MLD_RPTPEND; } while (0)
 
-#define CLR_MLD_QUERIER(f)       do { (f) &= ~MLD_QUERIER; } while (0)
 #define CLR_MLD_STARTUP(f)       do { (f) &= ~MLD_STARTUP; } while (0)
-#define CLR_MLD_V1COMPAT(f)      do { (f) &= ~MLD_V1COMPAT; } while (0)
 #define CLR_MLD_LASTREPORT(f)    do { (f) &= ~MLD_LASTREPORT; } while (0)
 #define CLR_MLD_SCHEDMSG(f)      do { (f) &= ~MLD_SCHEDMSG; } while (0)
 #define CLR_MLD_WAITMSG(f)       do { (f) &= ~MLD_WAITMSG; } while (0)
 #define CLR_MLD_RPTPEND(f)       do { (f) &= ~MLD_RPTPEND; } while (0)
 
-#define IS_MLD_QUERIER(f)        (((f) & MLD_QUERIER) != 0)
 #define IS_MLD_STARTUP(f)        (((f) & MLD_STARTUP) != 0)
-#define IS_MLD_V1COMPAT(f)       (((f) & MLD_V1COMPAT) != 0)
 #define IS_MLD_LASTREPORT(f)     (((f) & MLD_LASTREPORT) != 0)
 #define IS_MLD_SCHEDMSG(f)       (((f) & MLD_SCHEDMSG) != 0)
 #define IS_MLD_WAITMSG(f)        (((f) & MLD_WAITMSG) != 0)
@@ -201,10 +211,6 @@ enum mld_msgtype_e
 
 /* This structure represents one group member.  There is a list of groups
  * for each device interface structure.
- *
- * There will be a group for the all systems group address but this
- * will not run the state machine as it is used to kick off reports
- * from all the other groups
  */
 
 typedef FAR struct wdog_s *WDOG_ID;
@@ -214,7 +220,6 @@ struct mld_group_s
   net_ipv6addr_t      grpaddr; /* Group IPv6 address */
   struct work_s       work;    /* For deferred timeout operations */
   WDOG_ID             polldog; /* Timer used for periodic or delayed events */
-  WDOG_ID             v1dog;   /* MLDv1 compatibility mode timer */
   sem_t               sem;     /* Used to wait for message transmission */
 #ifdef CONFIG_NET_MLD_ROUTER
   uint16_t            members; /* Number of members currently reporting (excludes us) */
@@ -287,7 +292,7 @@ int mld_query(FAR struct net_driver_s *dev,
  * Name: mld_report_v1
  *
  * Description:
- *  Called from icmpv6_input() when a Version 1 Multicast Listener Report is
+ *  Called from icmpv6_input() when a MLDv1 Multicast Listener Report is
  *   received.
  *
  ****************************************************************************/
@@ -363,6 +368,18 @@ FAR struct mld_group_s *mld_grpallocfind(FAR struct net_driver_s *dev,
 void mld_grpfree(FAR struct net_driver_s *dev,
                  FAR struct mld_group_s *group);
 
+/****************************************************************************
+ * Name:  mld_new_pollcycle
+ *
+ * Description:
+ *   Update accumulated membership at the beginning of each new poll cycle
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NET_MLD_ROUTER
+void mld_new_pollcycle(FAR struct net_driver_s *dev);
+#endif
+
 /****************************************************************************
  * Name: mld_schedmsg
  *
@@ -431,7 +448,7 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
  *
  ****************************************************************************/
 
-uint8_t mld_report_msgtype(FAR struct mld_group_s *group);
+uint8_t mld_report_msgtype(FAR struct net_driver_s *dev);
 
 /****************************************************************************
  * Name:  mld_joingroup
@@ -474,14 +491,14 @@ int mld_joingroup(FAR const struct ipv6_mreq *mrec);
 int mld_leavegroup(FAR const struct ipv6_mreq *mrec);
 
 /****************************************************************************
- * Name:  mld_start_polltimer
+ * Name:  mld_start_gentimer
  *
  * Description:
- *   Start the MLD poll timer.
+ *   Start/Re-start the general query timer.
  *
  ****************************************************************************/
 
-void mld_start_polltimer(FAR struct mld_group_s *group, clock_t ticks);
+void mld_start_gentimer(FAR struct net_driver_s *dev, clock_t ticks);
 
 /****************************************************************************
  * Name:  mld_start_v1timer
@@ -491,7 +508,17 @@ void mld_start_polltimer(FAR struct mld_group_s *group, clock_t ticks);
  *
  ****************************************************************************/
 
-void mld_start_v1timer(FAR struct mld_group_s *group, clock_t ticks);
+void mld_start_v1timer(FAR struct net_driver_s *dev, clock_t ticks);
+
+/****************************************************************************
+ * Name:  mld_start_polltimer
+ *
+ * Description:
+ *   Start the MLD poll timer.
+ *
+ ****************************************************************************/
+
+void mld_start_polltimer(FAR struct mld_group_s *group, clock_t ticks);
 
 /****************************************************************************
  * Name:  mld_addmcastmac

net/mld/mld_group.c

@@ -109,31 +109,28 @@ FAR struct mld_group_s *mld_grpalloc(FAR struct net_driver_s *dev,
           goto errout_with_sem;
         }
 
-      group->v1dog = wd_create();
-      DEBUGASSERT(group->v1dog != NULL);
-      if (group->v1dog == NULL)
-        {
-          goto errout_with_polldog;
-        }
-
       /* Save the interface index */
 
       group->ifindex = dev->d_ifindex;
 
-      /* All routers start up as a Querier on each of their attached links. */
+#ifndef CONFIG_CONFIG_NET_MLD_ROUTER
+      /* Start the query timer if we are the Querier and this is the first
+       * group member of the group.
+       */
 
-      SET_MLD_QUERIER(group->flags);
+      if (dev->d_mld.grplist.head == NULL)
+        {
+          mld_start_gentimer(dev, MSEC2TICK(MLD_QUERY_MSEC));
+        }
+#endif
 
       /* Add the group structure to the list in the device structure */
 
-      sq_addfirst((FAR sq_entry_t *)group, &dev->d_mld_grplist);
+      sq_addfirst((FAR sq_entry_t *)group, &dev->d_mld.grplist);
     }
 
   return group;
 
-errout_with_polldog:
-  wd_delete(group->polldog);
-
 errout_with_sem:
   (void)nxsem_destroy(&group->sem);
   kmm_free(group);
@@ -160,7 +157,7 @@ FAR struct mld_group_s *mld_grpfind(FAR struct net_driver_s *dev,
           addr[0], addr[1], addr[2], addr[3], addr[4], addr[5], addr[6],
           addr[7]);
 
-  for (group = (FAR struct mld_group_s *)dev->d_mld_grplist.head;
+  for (group = (FAR struct mld_group_s *)dev->d_mld.grplist.head;
        group;
        group = group->next)
     {
@@ -222,11 +219,10 @@ void mld_grpfree(FAR struct net_driver_s *dev, FAR struct mld_group_s *group)
   /* Cancel the timers */
 
   wd_cancel(group->polldog);
-  wd_cancel(group->v1dog);
 
   /* Remove the group structure from the group list in the device structure */
 
-  sq_rem((FAR sq_entry_t *)group, &dev->d_mld_grplist);
+  sq_rem((FAR sq_entry_t *)group, &dev->d_mld.grplist);
 
   /* Destroy the wait semaphore */
 
@@ -235,12 +231,53 @@ void mld_grpfree(FAR struct net_driver_s *dev, FAR struct mld_group_s *group)
   /* Destroy the timers */
 
   wd_delete(group->polldog);
-  wd_delete(group->v1dog);
 
   /* Then release the group structure resources. */
 
   mldinfo("Call sched_kfree()\n");
   kmm_free(group);
+
+#ifndef CONFIG_CONFIG_NET_MLD_ROUTER
+  /* If there are no longer any groups, then stop the general query and v1
+   * compatibility timers.
+   */
+
+  if (dev->d_mld.grplist.head == NULL)
+    {
+      wd_cancel(dev->d_mld.gendog);
+      wd_cancel(dev->d_mld.v1dog);
+    }
+#endif
 }
 
+/****************************************************************************
+ * Name:  mld_new_pollcycle
+ *
+ * Description:
+ *   Update accumulated membership at the beginning of each new poll cycle
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NET_MLD_ROUTER
+void mld_new_pollcycle(FAR struct net_driver_s *dev)
+{
+  FAR struct mld_group_s *member;
+
+  /* Update member ship in every group  */
+
+   for (member = (FAR struct mld_group_s *)dev->d_mld.grplist.head;
+        member;
+        member = member->next)
+     {
+       /* Save the number of members that reported in the previous query
+        * cycle; reset the number of members that have reported in the new
+        * query cycle.
+        */
+
+       member->lstmbrs = member->members;
+       member->members = 0;
+     }
+}
+#endif
+
 #endif /* CONFIG_NET_MLD */

net/mld/mld_initialize.c

@@ -38,9 +38,11 @@
 
 #include <nuttx/config.h>
 
+#include <string.h>
 #include <assert.h>
 #include <debug.h>
 
+#include <nuttx/wdog.h>
 #include <nuttx/net/netdev.h>
 #include <nuttx/net/ip.h>
 #include <nuttx/net/mld.h>
@@ -77,7 +79,18 @@ void mld_initialize(void)
 void mld_devinit(struct net_driver_s *dev)
 {
   mldinfo("MLD initializing dev %p\n", dev);
-  DEBUGASSERT(dev->d_mld_grplist.head == NULL);
+
+  /* Initialize the MLD state in the device structure */
+
+  memset(&dev->d_mld, 0, sizeof(struct mld_netdev_s));
+
+  dev->d_mld.gendog = wd_create();
+  dev->d_mld.v1dog  = wd_create();
+  DEBUGASSERT(dev->d_mld.gendog != NULL && dev->d_mld.v1dog != NULL);
+
+  /* All routers start up as a Querier on each of their attached links. */
+
+  SET_MLD_QUERIER(dev->d_mld.flags);
 
   /* Add the all nodes address to the group */
 
@@ -88,4 +101,10 @@ void mld_devinit(struct net_driver_s *dev)
   mld_addmcastmac(dev, g_ipv6_allnodes);
   mld_addmcastmac(dev, g_ipv6_allrouters);
   mld_addmcastmac(dev, g_ipv6_allmldv2routers);
+
+#ifdef CONFIG_CONFIG_NET_MLD_ROUTER
+  /* Start the general query timer. */
+
+  mld_start_gentimer(dev, MSEC2TICK(MLD_QUERY_MSEC));
+#endif
 }

net/mld/mld_leave.c

@@ -193,7 +193,6 @@ int mld_leavegroup(FAR const struct ipv6_mreq *mrec)
                */
 
               wd_cancel(group->polldog);
-              wd_cancel(group->v1dog);
               CLR_MLD_SCHEDMSG(group->flags);
               CLR_MLD_WAITMSG(group->flags);
 

net/mld/mld_poll.c

@@ -78,9 +78,28 @@ void mld_poll(FAR struct net_driver_s *dev)
   dev->d_len     = 0;
   dev->d_sndlen  = 0;
 
+  /* Check if a general query is pending */
+
+  if (IS_MLD_GENPEND(dev->d_mld.flags))
+    {
+      /* Clear the pending flag */
+
+      CLR_MLD_GENPEND(dev->d_mld.flags);
+
+      /* Are we still the querier? */
+
+      if (IS_MLD_QUERIER(dev->d_mld.flags))
+        {
+          /* Yes, send the general query and return */
+
+          mld_send(dev, NULL, MLD_SEND_GENQUERY);
+          return;
+        }
+    }
+
   /* Check each member of the group */
 
-  for (group = (FAR struct mld_group_s *)dev->d_mld_grplist.head;
+  for (group = (FAR struct mld_group_s *)dev->d_mld.grplist.head;
        group;
        group = group->next)
     {
@@ -120,7 +139,7 @@ void mld_poll(FAR struct net_driver_s *dev)
         {
           /* Yes.. create the MLD message in the driver buffer */
 
-          mld_send(dev, group, mld_report_msgtype(group));
+          mld_send(dev, group, mld_report_msgtype(dev));
 
           /* Indicate that the report is no longer pending */
 

net/mld/mld_query.c

@@ -65,7 +65,7 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: mld_setup_v1compat
+ * Name: mld_check_v1compat
  *
  * Description:
  *   If this is for MLDv1 query, then select MLDv1 compatibility mode and
@@ -74,21 +74,11 @@
  *
  ****************************************************************************/
 
-static void mld_setup_v1compat(FAR struct mld_group_s *group,
-                               FAR const struct mld_mcast_listen_query_s *query,
-                               bool mldv1)
+static inline void mld_check_v1compat(FAR struct net_driver_s *dev,
+                                      bool mldv1)
 {
-  unsigned int respmsec;
-
   if (mldv1)
     {
-#if 0 /* REVISIT */
-      /* Get the QQI from the query.  Since this is MLDv1, we know that
-       * the value is not encoded.
-       */
-
-      respmsec = MSEC_PER_SEC * MLD_QQI_VALUE(query->qqic);
-#else
       /* REVISIT:  I am confused.  Per RFC 3810:
        * "The Older Version Querier Present Timeout is the time-out for
        *  transitioning a host back to MLDv2 Host Compatibility Mode.  When
@@ -103,34 +93,20 @@ static void mld_setup_v1compat(FAR struct mld_group_s *group,
        * field.  That is an MLDv2 extension.
        */
 
-      respmsec = MLD_QUERY_MSEC;
-#endif
-
       /* Select MLDv1 compatibility mode (might already be selected) */
 
-      SET_MLD_V1COMPAT(group->flags);
+      SET_MLD_V1COMPAT(dev->d_mld.flags);
 
-      /* Whenever a host changes its compatibility mode, it cancels all its
-       * pending responses and retransmission timers.
+      /* REVISIT: Whenever a host changes its compatibility mode, it cancels
+       * all its pending responses and retransmission timers.  Logic Missing.
        */
 
-      wd_cancel(group->polldog);
-
-      /* REVISIT:  We cannot cancel a pending message if there is a waiter.
-       * Some additional logic would be required to avoid a hang.
-       */
-
-      if (!IS_MLD_WAITMSG(group->flags))
-        {
-          CLR_MLD_SCHEDMSG(group->flags);
-        }
-
       /* And start the MLDv1 compatibility timer.  If the timer is already
        * running, this will reset the timer.
        */
 
-      mld_start_v1timer(group,
-                        MSEC2TICK(MLD_V1PRESENT_MSEC((clock_t)respmsec)));
+      mld_start_v1timer(dev,
+                        MSEC2TICK(MLD_V1PRESENT_MSEC((clock_t)MLD_QUERY_MSEC)));
     }
 }
 
@@ -197,21 +173,19 @@ static bool mld_cmpaddr(FAR struct net_driver_s *dev,
  * Name: mld_check_querier
  *
  * Description:
- *   Check if we are still the querier for this group (assuming that we are
- *   currently the querier).  This compares the IPv6 Source Address of the
- *   query against and the IPv6 address of the link.  Ff the source address
- *   is numerically less than the link address, when we are no longer the
- *   querier.
+ *   Check if we are still the querier (assuming that we are currently the
+ *   querier).  This compares the IPv6 Source Address of the query against
+ *   the IPv6 address of the link.  If the source address is numerically
+ *   less than the link address, when we are no longer the querier.
  *
  ****************************************************************************/
 
 static void mld_check_querier(FAR struct net_driver_s *dev,
-                              FAR struct ipv6_hdr_s *ipv6,
-                              FAR struct mld_group_s *group)
+                              FAR struct ipv6_hdr_s *ipv6)
 {
   /* Check if this member is a Querier */
 
-  if (IS_MLD_QUERIER(group->flags))
+  if (IS_MLD_QUERIER(dev->d_mld.flags))
     {
       /* This is a querier, check if the IPv6 source address is numerically
        * less than the IPv6 address assigned to this link.
@@ -221,21 +195,17 @@ static void mld_check_querier(FAR struct net_driver_s *dev,
         {
           /* Switch to non-Querier mode */
 
-           CLR_MLD_QUERIER(group->flags);
+          CLR_MLD_QUERIER(dev->d_mld.flags);
         }
     }
 
-  /* Check if the member is a Non-Querier AND that we are past the start up
-   * phase (where the timer is used for a different purpose)?
-   */
+  /* Check if the member is a Non-Querier. */
 
-  if (!IS_MLD_QUERIER(group->flags) && !IS_MLD_STARTUP(group->flags))
+  if (!IS_MLD_QUERIER(dev->d_mld.flags))
     {
-      /* Yes.. cancel the poll timer and [re-]start the 'Other Querier
-       * Present' Timeout.
-       */
+      /* Yes.. [re-]start the 'Other Querier Present' Timeout. */
 
-      mld_start_polltimer(group, MSEC2TICK(MLD_OQUERY_MSEC));
+      mld_start_gentimer(dev, MSEC2TICK(MLD_OQUERY_MSEC));
     }
 }
 
@@ -307,6 +277,13 @@ int mld_query(FAR struct net_driver_s *dev,
       return -EINVAL;
     }
 
+  /* Warn if we received a MLDv2 query in MLDv1 compatibility mode. */
+
+  if (!mldv1 && IS_MLD_V1COMPAT(dev->d_mld.flags))
+    {
+      mldwarn("WARNING: MLDv2 query received in MLDv1 compatibility mode\n");
+    }
+
   /* There are three variants of the Query message (RFC 3810):
    *
    * 1. A "General Query" is sent by the Querier to learn which
@@ -352,64 +329,37 @@ int mld_query(FAR struct net_driver_s *dev,
       mldinfo("General multicast query\n");
       MLD_STATINCR(g_netstats.mld.gm_query_received);
 
-      /* Two passes through the member list.  On the first, just check if we
-       * are still the querier for the qroup.
-       */
+      /* Check if we are still the querier for this sub-net */
 
-      for (member = (FAR struct mld_group_s *)dev->d_mld_grplist.head;
-           member;
-           member = member->next)
-        {
-          /* Skip over the all systems group entry */
-
-          if (!net_ipv6addr_cmp(member->grpaddr, g_ipv6_allnodes))
-            {
-              /* Check if we are still the querier for this group */
-
-               mld_check_querier(dev, ipv6, member);
-
-              /* Warn if we received a MLDv2 query in MLDv1 compatibility
-               * mode.
-               */
-
-              if (!mldv1 && IS_MLD_V1COMPAT(member->flags))
-                {
-                  mldinfo("WARNING: MLDv2 query received in MLDv1 "
-                          "compatibility mode\n");
-                }
+      mld_check_querier(dev, ipv6);
 
 #ifdef CONFIG_NET_MLD_ROUTER
-              /* Save the number of members that reported in the previous
-               * query cycle; reset the number of members that have
-               * reported in the new query cycle.
-               */
-
-              member->lstmbrs = member->members;
-              member->members = 0;
-#endif
-            }
-        }
-
-      /* On the second time through, we send the Report in response to the
-       * query.  This has to be done twice because because there is only
-       * a single packet buffer that is used for both incoming and outgoing
-       * packets.  When the report is sent, it will clobber the incoming
-       * query.  Any attempt to send an additional Report would also clobber
-       * a preceding report
+      /* Update accumulated membership at the beginning of each new poll
+       * cycle
        */
 
-      for (member = (FAR struct mld_group_s *)dev->d_mld_grplist.head;
-           member;
+      mld_new_pollcycle(dev)
+#endif
+
+      /* Check MLDv1 compatibility mode */
+
+      mld_check_v1compat(dev, mldv1);
+
+      /* Send the Report in response to the query.  This has to be done
+       * multiple times because because there is only a single packet buffer
+       * that is used for both incoming and outgoing packets.  When the
+       * report is sent, it will clobber the incoming* query.  Any attempt
+       * to send an additional Report would also clobber a preceding report
+       */
+
+      for (member = (FAR struct mld_group_s *)dev->d_mld.grplist.head;
+           member != NULL;
            member = member->next)
         {
           /* Skip over the all systems group entry */
 
           if (!net_ipv6addr_cmp(member->grpaddr, g_ipv6_allnodes))
             {
-              /* Check MLDv1 compatibility mode */
-
-              mld_setup_v1compat(member, query, mldv1);
-
               /* Have we already sent a report from this loop? */
 
               if (rptsent)
@@ -424,7 +374,7 @@ int mld_query(FAR struct net_driver_s *dev,
                 {
                   /* No.. Send one report now. */
 
-                  mld_send(dev, member, mld_report_msgtype(member));
+                  mld_send(dev, member, mld_report_msgtype(dev));
                   rptsent = true;
                   CLR_MLD_RPTPEND(member->flags);
                 }
@@ -458,7 +408,7 @@ int mld_query(FAR struct net_driver_s *dev,
 
   /* Check if we are still the querier for this group */
 
-  mld_check_querier(dev, ipv6, group);
+  mld_check_querier(dev, ipv6);
 
 #ifdef CONFIG_NET_MLD_ROUTER
   /* Save the number of members that reported in the previous query cycle;
@@ -471,7 +421,7 @@ int mld_query(FAR struct net_driver_s *dev,
 
   /* Warn if we received a MLDv2 query in MLDv1 compatibility mode. */
 
-  if (!mldv1 && IS_MLD_V1COMPAT(group->flags))
+  if (!mldv1 && IS_MLD_V1COMPAT(dev->d_mld.flags))
     {
       mldinfo("WARNING: MLDv2 query received in MLDv1 compatibility mode\n");
     }
@@ -496,11 +446,12 @@ int mld_query(FAR struct net_driver_s *dev,
 
       /* Check MLDv1 compatibility mode */
 
-      mld_setup_v1compat(group, query, mldv1);
+      mld_check_v1compat(dev, mldv1);
 
       /* Send the report */
 
-      mld_send(dev, group,  mld_report_msgtype(group));
+      mld_send(dev, group,  mld_report_msgtype(dev));
+      CLR_MLD_RPTPEND(group->flags);
     }
 
   /* Not sent to all systems.  Check for Unicast General Query */
@@ -512,11 +463,12 @@ int mld_query(FAR struct net_driver_s *dev,
 
       /* Check MLDv1 compatibility mode */
 
-      mld_setup_v1compat(group, query, mldv1);
+      mld_check_v1compat(dev, mldv1);
 
       /* Send the report */
 
-      mld_send(dev, group,  mld_report_msgtype(group));
+      mld_send(dev, group,  mld_report_msgtype(dev));
+      CLR_MLD_RPTPEND(group->flags);
     }
   else
     {

net/mld/mld_report.c

@@ -157,7 +157,7 @@ int mld_report(FAR struct net_driver_s *dev, FAR const net_ipv6addr_t grpaddr)
 int mld_report_v1(FAR struct net_driver_s *dev,
                   FAR const struct mld_mcast_listen_report_v1_s *report)
 {
-  mldinfo("Version 1 Multicast Listener Report\n");
+  mldinfo("MLDv1 Multicast Listener Report\n");
   DEBUGASSERT(dev != NULL && report != NULL);
 
   MLD_STATINCR(g_netstats.mld.v1report_received);

net/mld/mld_send.c

@@ -120,6 +120,11 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
   FAR const uint16_t *destipaddr;
   unsigned int mldsize;
 
+  /* Only a general query message can have a NULL group */
+
+  DEBUGASSERT(dev != NULL);
+  DEBUGASSERT(msgtype == MLD_SEND_GENQUERY || group != NULL);
+
   /* Select IPv6 */
 
   IFF_SET_IPv6(dev->d_flags);
@@ -131,7 +136,8 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
       case MLD_SEND_GENQUERY:           /* Send General Query */
       case MLD_SEND_MASQUERY:           /* Send Multicast Address Specific (MAS) Query */
         {
-          mldinfo("Send General Query, flags=%02x\n", group->flags);
+          mldinfo("Send General/MAS Query, flags=%02x\n",
+                  group != NULL ? group->flags : dev->d_mld.flags);
           mldsize = SIZEOF_MLD_MCAST_LISTEN_QUERY_S(0);
         }
         break;
@@ -290,7 +296,7 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
 
           /* Fields unique to the extended MLDv2 query */
 
-          if (!IS_MLD_V1COMPAT(group->flags))
+          if (!IS_MLD_V1COMPAT(dev->d_mld.flags))
             {
               query->flags  = MLD_ROBUSTNESS;
               query->qqic   = MLD_QRESP_SEC;
@@ -307,13 +313,21 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
           /* Save the number of members that reported in the previous query
            * cycle;  reset the number of members that have reported in the
            * new query cycle.
-           *
-           * REVISIT: This would have to be done for all groups, not just
-           * this one.
            */
 
-          group->lstmbrs = group->members;
-          group->members = 0;
+          if (msgtype == MLD_SEND_GENQUERY)
+            {
+              /* Update accumulated membership for all groups. */
+
+              mld_new_pollcycle(dev)
+            }
+          else
+            {
+              /* Updated accumulated membership only for this group */
+
+              group->lstmbrs = group->members;
+              group->members = 0;
+            }
 #endif
         }
         break;
@@ -404,9 +418,9 @@ void mld_send(FAR struct net_driver_s *dev, FAR struct mld_group_s *group,
  *
  ****************************************************************************/
 
-uint8_t mld_report_msgtype(FAR struct mld_group_s *group)
+uint8_t mld_report_msgtype(FAR struct net_driver_s *dev)
 {
-  if (IS_MLD_V1COMPAT(group->flags))
+  if (IS_MLD_V1COMPAT(dev->d_mld.flags))
     {
       return MLD_SEND_V1REPORT;
     }