emulation on host: fix binding from a particular interface (#7372)

allows to effectively use virtual interfaces (ifconfig eth0:1) with a different IP address

Author: d-a-v

tests/host/common/Arduino.h

@@ -20,7 +20,7 @@
 #ifndef Arduino_h
 #define Arduino_h
 
-#define MOCK "mock: "
+#define MOCK "(mock) "
 
 #ifdef __cplusplus
 extern "C" {

tests/host/common/MockWiFiServerSocket.cpp

@@ -101,7 +101,7 @@ void WiFiServer::begin ()
 
     	server.sin_family = AF_INET;
 	server.sin_port = htons(mockport);
-	server.sin_addr.s_addr = htonl(INADDR_ANY);
+	server.sin_addr.s_addr = htonl(global_source_address);
 	if (bind(sock, (struct sockaddr*)&server, sizeof(server)) == -1)
 	{
 		perror(MOCK "bind()");

tests/host/common/UdpContextSocket.cpp

@@ -76,9 +76,8 @@ bool mockUDPListen (int sock, uint32_t dstaddr, uint16_t port, uint32_t mcast)
 
 	// Filling server information
 	servaddr.sin_family = AF_INET;
-	//servaddr.sin_addr.s_addr = global_ipv4_netfmt?: dstaddr;
 	(void) dstaddr;
-	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
+	servaddr.sin_addr.s_addr = htonl(global_source_address);
 	servaddr.sin_port = htons(mockport);
 
 	// Bind the socket with the server address
@@ -97,8 +96,7 @@ bool mockUDPListen (int sock, uint32_t dstaddr, uint16_t port, uint32_t mcast)
 
 		struct ip_mreq mreq;
 		mreq.imr_multiaddr.s_addr = mcast;
-		//mreq.imr_interface.s_addr = global_ipv4_netfmt?: htonl(INADDR_ANY);
-		mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+		mreq.imr_interface.s_addr = htonl(global_source_address);
 		if (global_ipv4_netfmt)
 		{
 #if __APPLE__

tests/host/common/mock.h

@@ -112,6 +112,7 @@ extern const char* host_interface; // cmdline parameter
 extern bool serial_timestamp;
 extern int mock_port_shifter;
 extern bool blocking_uart;
+extern uint32_t global_source_address; // 0 = INADDR_ANY by default
 
 #define NO_GLOBAL_BINDING 0xffffffff
 extern uint32_t global_ipv4_netfmt; // selected interface addresse to bind to

tests/host/common/user_interface.cpp

@@ -117,41 +117,54 @@ void wifi_fpm_set_sleep_type (sleep_type_t type)
 uint32_t global_ipv4_netfmt = 0; // global binding
 
 netif netif0;
+uint32_t global_source_address = INADDR_ANY;
 
 bool wifi_get_ip_info (uint8 if_index, struct ip_info *info)
 {
+    // emulate wifi_get_ip_info()
+    // ignore if_index
+    // use global option -i (host_interface) to select bound interface/address
+
 	struct ifaddrs * ifAddrStruct = NULL, * ifa = NULL;
 	uint32_t ipv4 = lwip_htonl(0x7f000001);
 	uint32_t mask = lwip_htonl(0xff000000);
+	global_source_address = INADDR_ANY; // =0
 
 	if (getifaddrs(&ifAddrStruct) != 0)
 	{
 		perror("getifaddrs");
 		exit(EXIT_FAILURE);
 	}
+	if (host_interface)
+	    mockverbose("host: looking for interface '%s':\n", host_interface);
+	else
+	    mockverbose("host: looking the first for non-local IPv4 interface:\n");
 	for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next)
 	{
+        mockverbose("host: interface: %s", ifa->ifa_name);
 		if (   ifa->ifa_addr
 		    && ifa->ifa_addr->sa_family == AF_INET // ip_info is IPv4 only
 		   )
 		{
-			if (lwip_ntohl(*(uint32_t*)&((struct sockaddr_in*) ifa->ifa_netmask)->sin_addr) != 0xff000000)
+		    auto test_ipv4 = lwip_ntohl(*(uint32_t*)&((struct sockaddr_in*)ifa->ifa_addr)->sin_addr);
+            mockverbose(" IPV4 (0x%08lx)", test_ipv4);
+			if ((test_ipv4 & 0xff000000) == 0x7f000000)
+			    // 127./8
+			    mockverbose(" (local, ignored)");
+			else
 			{
-				if (ipv4 == lwip_htonl(0x7f000001))
-				{
-					// take the first by default
-					ipv4 = *(uint32_t*)&((struct sockaddr_in*)ifa->ifa_addr)->sin_addr;
-					mask = *(uint32_t*)&((struct sockaddr_in*)ifa->ifa_netmask)->sin_addr;
-				}
-				if (host_interface && strcmp(ifa->ifa_name, host_interface) == 0)
+				if (!host_interface || (host_interface && strcmp(ifa->ifa_name, host_interface) == 0))
 				{
-					// .. or the one specified by user on cmdline
+					// use the first non-local interface, or, if specified, the one selected by user on cmdline
 					ipv4 = *(uint32_t*)&((struct sockaddr_in*)ifa->ifa_addr)->sin_addr;
 					mask = *(uint32_t*)&((struct sockaddr_in*)ifa->ifa_netmask)->sin_addr;
+				    mockverbose(" (selected)\n");
+				    global_source_address = ntohl(ipv4);
 					break;
 				}
 			}
 		}
+		mockverbose("\n");
 	}
 	if (ifAddrStruct != NULL)
 		freeifaddrs(ifAddrStruct);