From 7492fe42c280b57d9579db4f3a2a34366874f743 Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Mon, 27 Nov 2017 23:04:22 +0100
Subject: [PATCH] pcpserver.c: send ANNOUNCE when IP changed

see #254
---
 miniupnpd/miniupnpd.c |  6 ++++-
 miniupnpd/pcpserver.c | 56 ++++++++++++++++++++++++++++++++++++++++++-
 miniupnpd/pcpserver.h |  6 ++++-
 3 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/miniupnpd/miniupnpd.c b/miniupnpd/miniupnpd.c
index 1c5275d..55a3d31 100644
--- a/miniupnpd/miniupnpd.c
+++ b/miniupnpd/miniupnpd.c
@@ -2064,7 +2064,11 @@ main(int argc, char * * argv)
 #ifdef ENABLE_PCP
 			if(GETFLAG(ENABLENATPMPMASK))
 			{
-				PCPPublicAddressChanged();
+#ifdef ENABLE_IPV6
+				PCPPublicAddressChanged(snatpmp, addr_count, spcp_v6);
+#else /* IPv4 only */
+				PCPPublicAddressChanged(snatpmp, addr_count);
+#endif
 			}
 #endif
 			should_send_public_address_change_notif = 0;
diff --git a/miniupnpd/pcpserver.c b/miniupnpd/pcpserver.c
index 8faccb2..0c34bca 100644
--- a/miniupnpd/pcpserver.c
+++ b/miniupnpd/pcpserver.c
@@ -1636,11 +1636,65 @@ int OpenAndConfPCPv6Socket(void)
 }
 #endif /*ENABLE_IPV6*/
 
-void PCPPublicAddressChanged(void)
+#ifdef ENABLE_IPV6
+static void PCPSendUnsolicitedAnnounce(int * sockets, int n_sockets, int socket6)
+#else /* IPv4 only */
+static void PCPSendUnsolicitedAnnounce(int * sockets, int n_sockets)
+#endif
+{
+	int i;
+	unsigned char buff[PCP_MIN_LEN];
+	pcp_info_t info;
+	ssize_t len;
+	struct sockaddr_in addr;
+#ifdef ENABLE_IPV6
+	struct sockaddr_in6 addr6;
+#endif /* ENABLE_IPV6 */
+	/* this is an Unsolicited ANNOUNCE response */
+
+	info.version = this_server_info.server_version;
+	info.opcode = PCP_OPCODE_ANNOUNCE;
+	info.result_code = PCP_SUCCESS;
+	info.lifetime = 0;
+	createPCPResponse(buff, &info);
+	/* Multicast PCP restart announcements are sent to
+	 * 224.0.0.1:5350 and/or [ff02::1]:5350 */
+	memset(&addr, 0, sizeof(struct sockaddr_in));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = inet_addr("224.0.0.1");
+	addr.sin_port = htons(5350);
+	for(i = 0; i < n_sockets; i++) {
+		len = sendto_or_schedule(sockets[i], buff, PCP_MIN_LEN, 0, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
+		if( len < 0 ) {
+			syslog(LOG_ERR, "PCPSendUnsolicitedAnnounce() sendto(): %m");
+		}
+	}
+#ifdef ENABLE_IPV6
+	memset(&addr6, 0, sizeof(struct sockaddr_in6));
+	addr6.sin6_family = AF_INET6;
+	inet_pton(AF_INET6, "FF02::1", &(addr6.sin6_addr));
+	addr6.sin6_port = htons(5350);
+	len = sendto_or_schedule(socket6, buff, PCP_MIN_LEN, 0, (struct sockaddr *)&addr6, sizeof(struct sockaddr_in6));
+	if( len < 0 ) {
+		syslog(LOG_ERR, "PCPSendUnsolicitedAnnounce() IPv6 sendto(): %m");
+	}
+#endif /* ENABLE_IPV6 */
+}
+
+#ifdef ENABLE_IPV6
+void PCPPublicAddressChanged(int * sockets, int n_sockets, int socket6)
+#else /* IPv4 only */
+void PCPPublicAddressChanged(int * sockets, int n_sockets)
+#endif
 {
 	/* according to RFC 6887  8.5 :
 	 *   if the external IP address(es) of the NAT (controlled by
 	 *   the PCP server) changes, the Epoch time MUST be reset. */
 	epoch_origin = time(NULL);
+#ifdef ENABLE_IPV6
+	PCPSendUnsolicitedAnnounce(sockets, n_sockets, socket6);
+#else /* IPv4 Only */
+	PCPSendUnsolicitedAnnounce(sockets, n_sockets);
+#endif
 }
 #endif /*ENABLE_PCP*/
diff --git a/miniupnpd/pcpserver.h b/miniupnpd/pcpserver.h
index 7974c22..3357e4f 100644
--- a/miniupnpd/pcpserver.h
+++ b/miniupnpd/pcpserver.h
@@ -56,6 +56,10 @@ int OpenAndConfPCPv6Socket(void);
 /*
  * To be called when Public IP address changed (IPv4)
  */
-void PCPPublicAddressChanged(void);
+#ifdef ENABLE_IPV6
+void PCPPublicAddressChanged(int * sockets, int n_sockets, int socket6);
+#else /* IPV4 Only */
+void PCPPublicAddressChanged(int * sockets, int n_sockets);
+#endif
 
 #endif /* PCPSERVER_H_INCLUDED */