From f9be16e61bfdcbc7c786de6befefbf42aefca4ff Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Sat, 23 Nov 2019 22:55:57 +0100
Subject: [PATCH] Reset per-client domain blocking cache at receipt of SIGUSR2.
 This is a convenient alternative to sending SIGHUP (which also clears the
 entire DNS cache).

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 src/dnsmasq/dnsmasq.c   |  2 ++
 src/dnsmasq_interface.c | 20 ++++++++++++++++++++
 src/dnsmasq_interface.h |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/src/dnsmasq/dnsmasq.c b/src/dnsmasq/dnsmasq.c
index f01167e1..2cb2ddc0 100644
--- a/src/dnsmasq/dnsmasq.c
+++ b/src/dnsmasq/dnsmasq.c
@@ -1412,6 +1412,8 @@ static void async_event(int pipe, time_t now)
 	   we leave them logging to the old file. */
 	if (daemon->log_file != NULL)
 	  log_reopen(daemon->log_file);
+
+	FTL_reset_per_client_domain_data();
 	break;
 
       case EVENT_NEWADDR:
diff --git a/src/dnsmasq_interface.c b/src/dnsmasq_interface.c
index fd6f85f9..37b672b0 100644
--- a/src/dnsmasq_interface.c
+++ b/src/dnsmasq_interface.c
@@ -1556,3 +1556,23 @@ static void prepare_blocking_metadata(void)
 	// Free IPv6addr
 	clearSetupVarsArray();
 }
+
+void FTL_reset_per_client_domain_data(void)
+{
+	logg("Received SIGUSR2, resetting domain blocking data");
+
+	for(int domainID = 0; domainID < counters->domains; domainID++)
+	{
+		domainsData *domain = getDomain(domainID, true);
+		if(domain == NULL)
+			continue;
+
+		for(int clientID = 0; clientID < counters->clients; clientID++)
+		{
+			// Reset all blocking yes/no fields for all domains and clients
+			// This forces a reprocessing of all available filters for any
+			// given domain and client the next time they are seen
+			domain->clientstatus->set(domain->clientstatus, clientID, UNKNOWN_BLOCKED);
+		}
+	}
+}
diff --git a/src/dnsmasq_interface.h b/src/dnsmasq_interface.h
index 2c969541..40822080 100644
--- a/src/dnsmasq_interface.h
+++ b/src/dnsmasq_interface.h
@@ -49,4 +49,6 @@ void _FTL_get_blocking_metadata(struct all_addr **addrp, unsigned int *flags, co
 void FTL_dnsmasq_reload(void);
 void FTL_fork_and_bind_sockets(struct passwd *ent_pw);
 
+void FTL_reset_per_client_domain_data(void);
+
 #endif // DNSMASQ_INTERFACE_H