From f9a1d72ce7a002463df1fa28f2fd146b77abd923 Mon Sep 17 00:00:00 2001
From: sl077 <sl077@gmx.de>
Date: Sun, 9 May 2021 13:55:31 +0200
Subject: [PATCH] Fix IPv6 Neighbor Discovery for PPP based protocols

---
 src/Cedar/Hub.c     |  2 +-
 src/Cedar/IPC.c     | 18 +++++-------------
 src/Mayaqua/TcpIp.c | 22 +++++++++++++++++++---
 src/Mayaqua/TcpIp.h |  2 +-
 4 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/Cedar/Hub.c b/src/Cedar/Hub.c
index 605405b4..38c6350f 100644
--- a/src/Cedar/Hub.c
+++ b/src/Cedar/Hub.c
@@ -1633,7 +1633,7 @@ void HubWatchDogThread(THREAD *t, void *param)
 								{
 									buf = BuildICMPv6NeighborSoliciation(&hub->HubIpV6,
 										&ip6addr,
-										hub->HubMacAddr, ++hub->HubIP6Id);
+										hub->HubMacAddr, ++hub->HubIP6Id, false);
 
 									if (buf != NULL)
 									{
diff --git a/src/Cedar/IPC.c b/src/Cedar/IPC.c
index ec3e7cc1..ecf76603 100644
--- a/src/Cedar/IPC.c
+++ b/src/Cedar/IPC.c
@@ -2109,13 +2109,12 @@ void IPCIPv6AssociateOnNDTEx(IPC *ipc, IP *ip, UCHAR *mac_address, bool isNeighb
 
 	addrType = GetIPAddrType6(ip);
 
-	if (addrType != IPV6_ADDR_LOCAL_UNICAST &&
-	        addrType != IPV6_ADDR_GLOBAL_UNICAST)
+	if (!(addrType & IPV6_ADDR_UNICAST))
 	{
 		return;
 	}
 
-	if (addrType == IPV6_ADDR_GLOBAL_UNICAST)
+	if (addrType & IPV6_ADDR_GLOBAL_UNICAST)
 	{
 		if (!IPCIPv6CheckUnicastFromRouterPrefix(ipc, ip, NULL))
 		{
@@ -2617,23 +2616,16 @@ void IPCIPv6SendUnicast(IPC *ipc, void *data, UINT size, IP *next_ip)
 			// Generate the MAC address from the multicast address
 			BUF *neighborSolicit;
 			UCHAR destMacAddress[6];
-			IPV6_ADDR solicitAddress;
 
 			char tmp[MAX_SIZE];
 			UCHAR *copy;
 			BLOCK *blk;
 
-			Zero(&solicitAddress, sizeof(IPV6_ADDR));
-			Copy(&solicitAddress.Value[13], &header->DestAddress.Value[13], 3);
-			solicitAddress.Value[0] = 0xFF;
-			solicitAddress.Value[1] = 0x02;
-			solicitAddress.Value[11] = 0x01;
-			solicitAddress.Value[12] = 0xFF;
-
-			neighborSolicit = BuildICMPv6NeighborSoliciation(&header->SrcAddress, &solicitAddress, ipc->MacAddress, 0);
+			neighborSolicit = BuildICMPv6NeighborSoliciation(&header->SrcAddress, &header->DestAddress, ipc->MacAddress, 0, true);
 			destMacAddress[0] = 0x33;
 			destMacAddress[1] = 0x33;
-			Copy(&destMacAddress[2], &solicitAddress.Value[12], sizeof(UINT));
+			destMacAddress[2] = 0xFF;
+			Copy(&destMacAddress[3], &header->DestAddress.Value[13], 3);
 			IPCIPv6SendWithDestMacAddr(ipc, neighborSolicit->Buf, neighborSolicit->Size, destMacAddress);
 
 			FreeBuf(neighborSolicit);
diff --git a/src/Mayaqua/TcpIp.c b/src/Mayaqua/TcpIp.c
index 82173803..c98f3f69 100644
--- a/src/Mayaqua/TcpIp.c
+++ b/src/Mayaqua/TcpIp.c
@@ -845,7 +845,7 @@ BUF *BuildICMPv6(IPV6_ADDR *src_ip, IPV6_ADDR *dest_ip, UCHAR hop_limit, UCHAR t
 }
 
 // Build an ICMPv6 Neighbor Solicitation packet
-BUF *BuildICMPv6NeighborSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCHAR *my_mac_address, UINT id)
+BUF *BuildICMPv6NeighborSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCHAR *my_mac_address, UINT id, bool use_multicast)
 {
 	ICMPV6_OPTION_LIST opt;
 	ICMPV6_OPTION_LINK_LAYER link;
@@ -875,8 +875,24 @@ BUF *BuildICMPv6NeighborSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCH
 	WriteBuf(b2, &header, sizeof(header));
 	WriteBufBuf(b2, b);
 
-	ret = BuildICMPv6(src_ip, target_ip, 255,
-	                  ICMPV6_TYPE_NEIGHBOR_SOLICIATION, 0, b2->Buf, b2->Size, id);
+	if (use_multicast)
+	{
+		IPV6_ADDR solicitAddress;
+		Zero(&solicitAddress, sizeof(IPV6_ADDR));
+		solicitAddress.Value[0] = 0xFF;
+		solicitAddress.Value[1] = 0x02;
+		solicitAddress.Value[11] = 0x01;
+		solicitAddress.Value[12] = 0xFF;
+		Copy(&solicitAddress.Value[13], &target_ip->Value[13], 3);
+
+		ret = BuildICMPv6(src_ip, &solicitAddress, 255,
+	                          ICMPV6_TYPE_NEIGHBOR_SOLICIATION, 0, b2->Buf, b2->Size, id);
+	}
+	else
+	{
+		ret = BuildICMPv6(src_ip, target_ip, 255,
+	                          ICMPV6_TYPE_NEIGHBOR_SOLICIATION, 0, b2->Buf, b2->Size, id);
+	}
 
 	FreeBuf(b);
 	FreeBuf(b2);
diff --git a/src/Mayaqua/TcpIp.h b/src/Mayaqua/TcpIp.h
index 4d35c5ef..aa5c42a8 100644
--- a/src/Mayaqua/TcpIp.h
+++ b/src/Mayaqua/TcpIp.h
@@ -792,7 +792,7 @@ BUF *BuildIPv6(IPV6_ADDR *dest_ip, IPV6_ADDR *src_ip, UINT id, UCHAR protocol, U
 BUF *BuildIPv6PacketHeader(IPV6_HEADER_PACKET_INFO *info, UINT *bytes_before_payload);
 UCHAR IPv6GetNextHeaderFromQueue(QUEUE *q);
 void BuildAndAddIPv6PacketOptionHeader(BUF *b, IPV6_OPTION_HEADER *opt, UCHAR next_header, UINT size);
-BUF *BuildICMPv6NeighborSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCHAR *my_mac_address, UINT id);
+BUF *BuildICMPv6NeighborSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCHAR *my_mac_address, UINT id, bool use_multicast);
 BUF *BuildICMPv6RouterSoliciation(IPV6_ADDR *src_ip, IPV6_ADDR *target_ip, UCHAR *my_mac_address, UINT id);
 BUF *BuildICMPv6(IPV6_ADDR *src_ip, IPV6_ADDR *dest_ip, UCHAR hop_limit, UCHAR type, UCHAR code, void *data, UINT size, UINT id);