Merge a366bdbf02 into bfaff4fdb0

Fix Virtual DHCP Server: Correct IP reassignment

developer_tools/vpnserver-jsonrpc-clients/README.html

@@ -30,6 +30,7 @@
 <ul>
 <li>Older versions of SoftEther VPN before June 2019 don't support JSON-RPC APIs.</li>
 <li>If you want to completely disable the JSON-RPC on your VPN Server, set the <code>DisableJsonRpcWebApi</code> variable to <code>true</code> on the <code>vpn_server.config</code>.</li>
+<li>You may also restrict access to JSON-RPC API to a specific subnet, e.g. your internal network, by setting the <code>JsonRpcWebApiAllowedSubnet</code> variable to, for example, <code>192.168.0.0/16</code>.</li>
 </ul>
 <h3 id="json-rpc-specification">JSON-RPC specification</h3>
 <p>You must use HTTPS 1.1 <code>POST</code> method to call each of JSON-RPC APIs.<br />

developer_tools/vpnserver-jsonrpc-clients/README.md

@@ -25,6 +25,7 @@ https://<vpn_server_hostname>:<port>/api/
 
   - Older versions of SoftEther VPN before June 2019 don't support JSON-RPC APIs.
   - If you want to completely disable the JSON-RPC on your VPN Server, set the `DisableJsonRpcWebApi` variable to `true` on the `vpn_server.config`.
+  - You may also restrict access to JSON-RPC API to a specific subnet, e.g. your internal network, by setting the `JsonRpcWebApiAllowedSubnet` variable to, for example, `192.168.0.0/16`.
 
 
 ### JSON-RPC specification

developer_tools/vpnserver-jsonrpc-codegen/Templates/doc.txt

@@ -25,6 +25,7 @@ https://<vpn_server_hostname>:<port>/api/
 
   - Older versions of SoftEther VPN before June 2019 don't support JSON-RPC APIs.
   - If you want to completely disable the JSON-RPC on your VPN Server, set the `DisableJsonRpcWebApi` variable to `true` on the `vpn_server.config`.
+  - You may also restrict access to JSON-RPC API to a specific subnet, e.g. your internal network, by setting the `JsonRpcWebApiAllowedSubnet` variable to, for example, `192.168.0.0/16`.
 
 
 ### JSON-RPC specification

src/Cedar/Protocol.c

@@ -5740,6 +5740,7 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 	UINT num = 0, max = 19;
 	SERVER *server;
 	char *vpn_http_target = HTTP_VPN_TARGET2;
+	bool disableJsonRpcWebApi;
 	// Validate arguments
 	if (c == NULL)
 	{
@@ -5750,6 +5751,15 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 
 	s = c->FirstSock;
 
+	disableJsonRpcWebApi = server->DisableJsonRpcWebApi;
+	if (!disableJsonRpcWebApi && !IsZeroIP(&server->JsonRpcWebApiAllowedSubnetAddr)
+				&& !IsZeroIP(&server->JsonRpcWebApiAllowedSubnetMask)) {
+		// restrict JSON-RPC Web API to specified subnet only
+		if (!IsInSameNetwork(&s->RemoteIP, &server->JsonRpcWebApiAllowedSubnetAddr, &server->JsonRpcWebApiAllowedSubnetMask)) {
+			disableJsonRpcWebApi = true;
+		}
+	}
+
 	while (true)
 	{
 		bool not_found_error = false;
@@ -5782,7 +5792,7 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 			// Receive the data since it's POST
 			data_size = GetContentLength(h);
 
-			if (server->DisableJsonRpcWebApi == false)
+			if (disableJsonRpcWebApi == false)
 			{
 				if (StrCmpi(h->Target, "/api") == 0 || StrCmpi(h->Target, "/api/") == 0)
 				{
@@ -5868,7 +5878,7 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 		}
 		else if (StrCmpi(h->Method, "OPTIONS") == 0)
 		{
-			if (server->DisableJsonRpcWebApi == false)
+			if (disableJsonRpcWebApi == false)
 			{
 				if (StrCmpi(h->Target, "/api") == 0 || StrCmpi(h->Target, "/api/") == 0 || StartWith(h->Target, "/admin"))
 				{
@@ -5939,7 +5949,7 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 					BUF *b = NULL;
 					*error_detail_str = "HTTP_ROOT";
 
-					if (server->DisableJsonRpcWebApi == false)
+					if (disableJsonRpcWebApi == false)
 					{
 						b = ReadDump("|wwwroot/index.html");
 					}
@@ -6019,7 +6029,7 @@ bool ServerDownloadSignature(CONNECTION *c, char **error_detail_str)
 
 					if (b == false)
 					{
-						if (server->DisableJsonRpcWebApi == false)
+						if (disableJsonRpcWebApi == false)
 						{
 							if (StartWith(h->Target, "/api?") || StartWith(h->Target, "/api/") || StrCmpi(h->Target, "/api") == 0)
 							{

src/Cedar/Server.c

@@ -30,6 +30,7 @@
 #include "Mayaqua/Internat.h"
 #include "Mayaqua/Memory.h"
 #include "Mayaqua/Microsoft.h"
+#include "Mayaqua/Network.h"
 #include "Mayaqua/Object.h"
 #include "Mayaqua/OS.h"
 #include "Mayaqua/Pack.h"
@@ -6032,6 +6033,15 @@ void SiLoadServerCfg(SERVER *s, FOLDER *f)
 		// Disable JSON-RPC Web API
 		s->DisableJsonRpcWebApi = CfgGetBool(f, "DisableJsonRpcWebApi");
 
+		char tmpaddr[MAX_PATH];
+		if (CfgGetStr(f, "JsonRpcWebApiAllowedSubnet", tmpaddr, sizeof(tmpaddr))) {
+			IP _subnet, _mask;
+			if (ParseIpAndMask46(tmpaddr, &_subnet, &_mask)) {
+				s->JsonRpcWebApiAllowedSubnetAddr = _subnet;
+				s->JsonRpcWebApiAllowedSubnetMask = _mask;
+			}
+		}
+
 		// Bits of Diffie-Hellman parameters
 		c->DhParamBits = CfgGetInt(f, "DhParamBits");
 		if (c->DhParamBits == 0)
@@ -6365,6 +6375,11 @@ void SiWriteServerCfg(FOLDER *f, SERVER *s)
 
 		// Disable JSON-RPC Web API
 		CfgAddBool(f, "DisableJsonRpcWebApi", s->DisableJsonRpcWebApi);
+
+		char tmpaddr[MAX_PATH];
+		IPAndMaskToStr(tmpaddr, sizeof(tmpaddr),
+			&s->JsonRpcWebApiAllowedSubnetAddr, &s->JsonRpcWebApiAllowedSubnetMask);
+		CfgAddStr(f, "JsonRpcWebApiAllowedSubnet", tmpaddr);
 	}
 	Unlock(c->lock);
 }

src/Cedar/Server.h

@@ -276,6 +276,9 @@ struct SERVER
 	IP ListenIP;						// Listen IP
 	bool StrictSyslogDatetimeFormat;	// Make syslog datetime format strict RFC3164
 	bool DisableJsonRpcWebApi;					// Disable JSON-RPC Web API
+
+	IP JsonRpcWebApiAllowedSubnetAddr;  // If set, allow access to JSON-RPC Web API from
+	IP JsonRpcWebApiAllowedSubnetMask;  //   this subnet only
 };
 
 

src/Cedar/Virtual.c

@@ -9349,62 +9349,35 @@ UINT ServeDhcpDiscoverEx(VH *v, UCHAR *mac, UINT request_ip, bool is_static_ip)
 		// check whether it is a request from the same MAC address
 		if (Cmp(mac, d->MacAddress, 6) == 0)
 		{
-			// Examine whether the specified IP address is within the range of assignment
+			// Examine whether the specified IP address is within the range of static assignment
 			if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
 				Endian32(request_ip) > Endian32(v->DhcpIpEnd))
 			{
-				// Accept if within the range
+				// Accept if within the range of static assignment
 				ret = request_ip;
 			}
 		}
 		else {
-			// Duplicated IPV4 address found. The DHCP server replies to DHCPREQUEST with DHCP NAK.
+			// Duplicated IPV4 address found. The specified IP address is not available for use
 			char ipstr[MAX_HOST_NAME_LEN + 1] = { 0 };
 			char macstr[128] = { 0 };
 			IPToStr32(ipstr, sizeof(ipstr), request_ip);
-			BinToStr(macstr, sizeof(macstr), d->MacAddress, 6);
-			Debug("Virtual DHC Server: Duplicated IP address detected. Static IP: %s, Used by MAC:%s\n", ipstr, macstr);
-			return ret;
+			MacToStr(macstr, sizeof(macstr), d->MacAddress);
+			Debug("Virtual DHC Server: Duplicated IP address detected. Static IP: %s, with the MAC: %s\n", ipstr, macstr);
 		}
 	}
 	else
 	{
-		// Examine whether the specified IP address is within the range of assignment
+		// Examine whether the specified IP address is within the range of static assignment
 		if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
 			Endian32(request_ip) > Endian32(v->DhcpIpEnd))
 		{
-			// Accept if within the range
+			// Accept if within the range of static assignment
 			ret = request_ip;
 		}
 		else
 		{
-			// Propose an IP in the range since it's a Discover although It is out of range
-		}
-	}
-	if (ret == 0)
-	{
-		// If there is any entry with the same MAC address
-		// that are already registered, use it with priority
-		DHCP_LEASE *d = SearchDhcpLeaseByMac(v, mac);
-
-		if (d != NULL)
-		{
-			// Examine whether the found IP address is in the allocation region
-			if (Endian32(v->DhcpIpStart) > Endian32(d->IpAddress) ||
-				Endian32(d->IpAddress) > Endian32(v->DhcpIpEnd))
-			{
-				// Use the IP address if it's found within the range
-				ret = d->IpAddress;
-			}
-		}
-	}
-	if (ret == 0)
-	{
-		// For static IP, the requested IP address must NOT be within the range of the DHCP pool
-		if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
-			Endian32(request_ip) > Endian32(v->DhcpIpEnd))
-		{
-			ret = request_ip;
+			// The specified IP address is not available for use
 		}
 	}
 
@@ -9595,6 +9568,11 @@ void VirtualDhcpServer(VH *v, PKT *p)
 			{
 				ip = ServeDhcpRequestEx(v, p->MacAddressSrc, opt->RequestedIp, ip_static);
 			}
+			// If the IP address in user's note is changed, then reply to DHCP_REQUEST with DHCP_NAK
+			if (p->L3.IPv4Header->SrcIP && ip != p->L3.IPv4Header->SrcIP)
+			{
+				ip = 0;
+			}
 		}
 
 		if (ip != 0 || opt->Opcode == DHCP_INFORM)
@@ -9607,6 +9585,14 @@ void VirtualDhcpServer(VH *v, PKT *p)
 				char client_mac[MAX_SIZE];
 				char client_ip[MAX_SIZE];
 
+				// If there is any entry with the same MAC address, then remove it
+				d = SearchDhcpLeaseByMac(v, p->MacAddressSrc);
+				if (d != NULL)
+				{
+					FreeDhcpLease(d);
+					Delete(v->DhcpLeaseList, d);
+				}
+
 				// Remove old records with the same IP address
 				d = SearchDhcpLeaseByIp(v, ip);
 				if (d != NULL)
@@ -9765,7 +9751,7 @@ void VirtualDhcpServer(VH *v, PKT *p)
 		}
 		else
 		{
-			// Reply of DHCP_REQUEST must be either DHCP_ACK or DHCP_NAK.
+			// Reply of DHCP_REQUEST must be either DHCP_ACK or DHCP_NAK
 			if (opt->Opcode == DHCP_REQUEST)
 			{
 				// There is no IP address that can be provided

src/Mayaqua/Network.c

@@ -6993,6 +6993,18 @@ void IPToStr6Inner(char *str, IP *ip)
 	}
 }
 
+// Format IP and subnet mask as "<ip>/<masksize>"
+void IPAndMaskToStr(char *str, UINT size, IP *ip, IP *subnet)
+{
+	int iplen;
+	UINT masksize;
+
+	IPToStr(str, size, ip);
+	iplen = StrLen(str);
+	masksize = SubnetMaskToInt(subnet);
+	Format(str + iplen, size - iplen, "/%d", masksize);
+}
+
 // Convert the string to an IP address
 bool StrToIP6(IP *ip, char *str)
 {
@@ -12288,6 +12300,11 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 			ret = SSL_peek(ssl, &c, sizeof(c));
 		}
 		Unlock(sock->ssl_lock);
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+		// 2021/09/10: After OpenSSL 3.x.x, both 0 and negative values might mean retryable.
+		// See: https://github.com/openssl/openssl/blob/435981cbadad2c58c35bacd30ca5d8b4c9bea72f/doc/man3/SSL_read.pod
+		// > Old documentation indicated a difference between 0 and -1, and that -1 was retryable.
+		// > You should instead call SSL_get_error() to find out if it's retryable.
 		if (ret == 0)
 		{
 			// The communication have been disconnected
@@ -12295,7 +12312,8 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 			Debug("%s %u SecureRecv() Disconnect\n", __FILE__, __LINE__);
 			return 0;
 		}
-		if (ret < 0)
+#endif
+		if (ret <= 0)
 		{
 			// An error has occurred
 			e = SSL_get_error(ssl, ret);
@@ -12310,7 +12328,9 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 #endif
 					)
 				{
-					Debug("%s %u SSL Fatal Error on ASYNC socket !!!\n", __FILE__, __LINE__);
+					UINT ssl_err_no = ERR_get_error();
+
+					Debug("%s %u SSL_ERROR_SSL on ASYNC socket !!! ssl_err_no = %u: '%s'\n", __FILE__, __LINE__, ssl_err_no, ERR_error_string(ssl_err_no, NULL));
 					Disconnect(sock);
 					return 0;
 				}
@@ -12357,7 +12377,11 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 		}
 #endif	// OS_UNIX
 
-		if (ret < 0)
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+		if (ret < 0) // OpenSSL version < 3.0.0
+#else
+		if (ret <= 0) // OpenSSL version >= 3.0.0
+#endif
 		{
 			e = SSL_get_error(ssl, ret);
 		}
@@ -12380,6 +12404,12 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 
 		return (UINT)ret;
 	}
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+	// 2021/09/10: After OpenSSL 3.x.x, both 0 and negative values might mean retryable.
+	// See: https://github.com/openssl/openssl/blob/435981cbadad2c58c35bacd30ca5d8b4c9bea72f/doc/man3/SSL_read.pod
+	// > Old documentation indicated a difference between 0 and -1, and that -1 was retryable.
+	// > You should instead call SSL_get_error() to find out if it's retryable.
 	if (ret == 0)
 	{
 		// Disconnect the communication
@@ -12387,6 +12417,8 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 		//Debug("%s %u SecureRecv() Disconnect\n", __FILE__, __LINE__);
 		return 0;
 	}
+#endif
+
 	if (sock->AsyncMode)
 	{
 		if (e == SSL_ERROR_WANT_READ || e == SSL_ERROR_WANT_WRITE || e == SSL_ERROR_SSL)
@@ -12400,7 +12432,9 @@ UINT SecureRecv(SOCK *sock, void *data, UINT size)
 #endif
 				)
 			{
-				Debug("%s %u SSL Fatal Error on ASYNC socket !!!\n", __FILE__, __LINE__);
+				UINT ssl_err_no = ERR_get_error();
+
+				Debug("%s %u SSL_ERROR_SSL on ASYNC socket !!! ssl_err_no = %u: '%s'\n", __FILE__, __LINE__, ssl_err_no, ERR_error_string(ssl_err_no, NULL));
 				Disconnect(sock);
 				return 0;
 			}
@@ -12438,7 +12472,11 @@ UINT SecureSend(SOCK *sock, void *data, UINT size)
 		}
 
 		ret = SSL_write(ssl, data, size);
-		if (ret < 0)
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+		if (ret < 0) // OpenSSL version < 3.0.0
+#else
+		if (ret <= 0) // OpenSSL version >= 3.0.0
+#endif
 		{
 			e = SSL_get_error(ssl, ret);
 		}
@@ -12460,6 +12498,8 @@ UINT SecureSend(SOCK *sock, void *data, UINT size)
 		sock->WriteBlocked = false;
 		return (UINT)ret;
 	}
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
 	if (ret == 0)
 	{
 		// Disconnect
@@ -12467,6 +12507,7 @@ UINT SecureSend(SOCK *sock, void *data, UINT size)
 		Disconnect(sock);
 		return 0;
 	}
+#endif
 
 	if (sock->AsyncMode)
 	{

src/Mayaqua/Network.h

@@ -1289,6 +1289,7 @@ void IPToStr6(char *str, UINT size, IP *ip);
 void IP6AddrToStr(char *str, UINT size, IPV6_ADDR *addr);
 void IPToStr6Array(char *str, UINT size, UCHAR *bytes);
 void IPToStr6Inner(char *str, IP *ip);
+void IPAndMaskToStr(char *str, UINT size, IP *ip, IP *subnet);
 void IntToSubnetMask6(IP *ip, UINT i);
 void IPAnd6(IP *dst, IP *a, IP *b);
 void GetAllRouterMulticastAddress6(IP *ip);