Proper IPv6 and dual stack networking

This means that rigctl & rigctld  now work with default arguments on a
modern Windows  machine with dual  stack and localhost being  [::1] as
the first interface returned by getaddrinfo().

Try all the interfaces return by DNS lookups to establish a connection
or listening  port. Handle  Windows network  errors correctly  so that
meaningful messages are printed.

The rigctl program now accepts  IPv6 numeric addresses in the portname
field like [<addr>}:<port> for example  the IPv6 loopback on port 4531
would be [::1]:4531.

src/network.c

@@ -73,6 +73,36 @@
 static int wsstarted;
 #endif
 
+static void handle_error (enum rig_debug_level_e lvl, const char *msg)
+{
+	int e;
+#ifdef __MINGW32__
+	LPVOID lpMsgBuf;
+
+	lpMsgBuf = (LPVOID)"Unknown error";
+	e = WSAGetLastError();
+	if (FormatMessage(
+			FORMAT_MESSAGE_ALLOCATE_BUFFER |
+			FORMAT_MESSAGE_FROM_SYSTEM |
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL, e,
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+				// Default language
+			(LPTSTR)&lpMsgBuf, 0, NULL))
+		{
+			rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, lpMsgBuf);
+			LocalFree(lpMsgBuf);
+		}
+	else
+		{
+			rig_debug (lvl, "%s: Network error %d\n", msg, e);
+		}
+#else
+	e = errno;
+	rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, strerror (e));
+#endif
+}
+
 /**
  * \brief Open network port using rig.state data
  *
@@ -87,9 +117,9 @@ int network_open(hamlib_port_t *rp, int default_port)
 {
 	int fd;				/* File descriptor for the port */
 	int status;
-	struct addrinfo hints, *res;
+	struct addrinfo hints, *res, *saved_res;
-	char *portstr;
+	char *hoststr, *portstr, *bracketstr1, *bracketstr2;
-	char hostname[FILPATHLEN] = "127.0.0.1";
+	char hostname[FILPATHLEN];
 	char defaultportstr[8];
 
 #ifdef __MINGW32__
@@ -110,48 +140,90 @@ int network_open(hamlib_port_t *rp, int default_port)
 	else
 		hints.ai_socktype = SOCK_STREAM;
 
-	if (rp->pathname[0] == ':') {
+	hoststr = NULL;								/* default of all local interfaces */
-		portstr = rp->pathname+1;
+	if (rp->pathname && rp->pathname[0] == ':')
-	} else {
+		{
-		strncpy(hostname, rp->pathname, FILPATHLEN-1);
+			portstr = rp->pathname + 1;
-
+		}
-		/* search last ':', because IPv6 may have some */
+	else
-		portstr = strrchr(hostname, ':');
+		{
-		if (portstr) {
+			if (strlen (rp->pathname))
-			*portstr++ = '\0';
+				{
-		} else {
+					strncpy(hostname, rp->pathname, FILPATHLEN-1);
-			sprintf(defaultportstr, "%d", default_port);
+					hoststr = hostname;
-			portstr = defaultportstr;
+					/* look for IPv6 numeric form [<addr>] */
+					bracketstr1 = strchr(hoststr, '[');
+					bracketstr2 = strrchr(hoststr, ']');
+					if (bracketstr1 && bracketstr2 && bracketstr2 > bracketstr1)
+						{
+							hoststr = bracketstr1 + 1;
+							*bracketstr2 = '\0';
+							portstr = bracketstr2 + 1; /* possible port after ]: */
+						}
+					else
+						{
+							bracketstr2 = NULL;
+							portstr = hoststr; /* possible port after : */
+						}
+					/* search last ':' */
+					portstr = strrchr(portstr, ':');
+					if (portstr)
+						{
+							*portstr++ = '\0';
+						}
+					else
+						{
+							sprintf(defaultportstr, "%d", default_port);
+							portstr = defaultportstr;
+						}
+				}
 		}
-	}
 
-	status=getaddrinfo(hostname, portstr, &hints, &res);
+	status=getaddrinfo(hoststr, portstr, &hints, &res);
 	if (status != 0) {
 		rig_debug(RIG_DEBUG_ERR, "Cannot get host \"%s\": %s\n",
 					rp->pathname, gai_strerror(errno));
 		return -RIG_ECONF;
 	}
+	saved_res = res;
 
 	/* we don't want a signal when connection get broken */
 #ifdef SIGPIPE
 	signal(SIGPIPE, SIG_IGN);
 #endif
 
-	fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+	do
-	if (fd < 0)
+		{
-		return -RIG_EIO;
+			fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+			if (fd < 0)
+				{
+					handle_error (RIG_DEBUG_ERR, "socket");
+					freeaddrinfo (saved_res);
+					return -RIG_EIO;
+				}
 
-	status = connect(fd, res->ai_addr, res->ai_addrlen);
+			if ((status = connect(fd, res->ai_addr, res->ai_addrlen)) == 0)
-	freeaddrinfo(res);
+				{
-	if (status < 0) {
+					break;
-		rig_debug(RIG_DEBUG_ERR, "Cannot open NET device \"%s\": %s\n",
+				}
-					rp->pathname, strerror(errno));
+			handle_error (RIG_DEBUG_WARN, "connect (trying next interface)");
-		close(fd);
+
+#ifdef __MINGW32__
+			closesocket (fd);
+#else
+			close (fd);
+#endif
+		} while ((res = res->ai_next) != NULL);
+
+	freeaddrinfo (saved_res);
+
+	if (NULL == res) {
+		rig_debug (RIG_DEBUG_ERR, "Failed to connect to %s\n"
+							 , rp->pathname ? rp->pathname : "localhost:4532");
 		return -RIG_EIO;
 	}
 
 	rp->fd = fd;
-
 	return RIG_OK;
 }
 

tests/rigctld.c

@@ -102,7 +102,7 @@ static struct option long_options[] =
 struct handle_data {
 	RIG *rig;
 	int sock;
-	struct sockaddr_in cli_addr;
+	struct sockaddr_storage cli_addr;
 	socklen_t clilen;
 };
 
@@ -120,6 +120,36 @@ const char *src_addr = NULL; /* INADDR_ANY */
 
 #define MAXCONFLEN 128
 
+static void handle_error (enum rig_debug_level_e lvl, const char *msg)
+{
+	int e;
+#ifdef __MINGW32__
+	LPVOID lpMsgBuf;
+
+	lpMsgBuf = (LPVOID)"Unknown error";
+	e = WSAGetLastError();
+	if (FormatMessage(
+			FORMAT_MESSAGE_ALLOCATE_BUFFER |
+			FORMAT_MESSAGE_FROM_SYSTEM |
+			FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL, e,
+			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+				// Default language
+			(LPTSTR)&lpMsgBuf, 0, NULL))
+		{
+			rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, lpMsgBuf);
+			LocalFree(lpMsgBuf);
+		}
+	else
+		{
+			rig_debug (lvl, "%s: Network error %d\n", msg, e);
+		}
+#else
+	e = errno;
+	rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, strerror (e));
+#endif
+}
+
 int main (int argc, char *argv[])
 {
 	RIG *my_rig;		/* handle to rig (instance) */
@@ -137,9 +167,12 @@ int main (int argc, char *argv[])
 	char *civaddr = NULL;	/* NULL means no need to set conf */
 	char conf_parms[MAXCONFLEN] = "";
 
-	struct addrinfo hints, *result;
+	int sockopt;
+	struct addrinfo hints, *result, *saved_result;
 	int sock_listen;
 	int reuseaddr = 1;
+	char host[NI_MAXHOST];
+	char serv[NI_MAXSERV];
 
 	while(1) {
 		int c;
@@ -283,13 +316,13 @@ int main (int argc, char *argv[])
 		}
 	}
 
-	rig_set_debug(verbose);
+  rig_set_debug(verbose);
 
 	rig_debug(RIG_DEBUG_VERBOSE, "rigctld, %s\n", hamlib_version);
 	rig_debug(RIG_DEBUG_VERBOSE, "Report bugs to "
 			"<hamlib-developer@lists.sourceforge.net>\n\n");
 
-  	my_rig = rig_init(my_model);
+	my_rig = rig_init(my_model);
 
 	if (!my_rig) {
 		fprintf(stderr, "Unknown rig num %d, or initialization error.\n",
@@ -370,7 +403,7 @@ int main (int argc, char *argv[])
 		exit(1);
 	}
 
-	int sockopt = SO_SYNCHRONOUS_NONALERT;
+	sockopt = SO_SYNCHRONOUS_NONALERT;
 	setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *)&sockopt, sizeof(sockopt));
 #endif
 
@@ -388,28 +421,56 @@ int main (int argc, char *argv[])
 	    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(retcode));
 	    exit(2);
 	}
+  saved_result = result;
 
-	sock_listen = socket(result->ai_family, result->ai_socktype,
+	do
-			result->ai_protocol);
+		{
-	if (sock_listen < 0) {
+			sock_listen = socket(result->ai_family, result->ai_socktype,
-		perror("ERROR opening socket");
+													 result->ai_protocol);
-		exit(2);
+			if (sock_listen < 0) {
-	}
+				handle_error (RIG_DEBUG_ERR, "socket");
+				freeaddrinfo(saved_result);		/* No longer needed */
+				exit(2);
+			}
 
-	if (setsockopt(sock_listen, SOL_SOCKET, SO_REUSEADDR,
+      if (setsockopt(sock_listen, SOL_SOCKET, SO_REUSEADDR,
-				(char *)&reuseaddr, sizeof(reuseaddr)) < 0) {
+										 (char *)&reuseaddr, sizeof(reuseaddr)) < 0) {
-		rig_debug(RIG_DEBUG_ERR, "setsockopt: %s\n", strerror(errno));
+				handle_error (RIG_DEBUG_ERR, "setsockopt");
-		exit (1);
+				freeaddrinfo(saved_result);		/* No longer needed */
-	}
+				exit (1);
-	if (bind(sock_listen, result->ai_addr, result->ai_addrlen) < 0) {
+			}
-		rig_debug(RIG_DEBUG_ERR, "binding: %s\n", strerror(errno));
-		exit (1);
-	}
 
-	freeaddrinfo(result);           /* No longer needed */
+#ifdef __MINGW32__
+			/* allow IPv4 mapped to IPv6 clients, MS default this to 1! */
+			sockopt = 0;
+      if (setsockopt(sock_listen, IPPROTO_IPV6, IPV6_V6ONLY,
+										 (char *)&sockopt, sizeof(sockopt)) < 0) {
+				handle_error (RIG_DEBUG_ERR, "setsockopt");
+				freeaddrinfo(saved_result);		/* No longer needed */
+				exit (1);
+			}
+#endif
+
+      if (0 == bind(sock_listen, result->ai_addr, result->ai_addrlen)) {
+				break;
+			}
+			handle_error (RIG_DEBUG_WARN, "binding failed (trying next interface)");
+#ifdef __MINGW32__
+			closesocket (sock_listen);
+#else
+			close (sock_listen);
+#endif
+		} while ((result = result->ai_next) != NULL);
+
+	freeaddrinfo(saved_result);		/* No longer needed */
+  if (NULL == result)
+		{
+			rig_debug(RIG_DEBUG_ERR, "bind error - no available interface\n");
+			exit (1);
+		}
 
 	if (listen(sock_listen, 4) < 0) {
-		rig_debug(RIG_DEBUG_ERR, "listening: %s\n", strerror(errno));
+		handle_error (RIG_DEBUG_ERR, "listening");
 		exit (1);
 	}
 
@@ -430,17 +491,20 @@ int main (int argc, char *argv[])
 		}
 
 		arg->rig = my_rig;
-		arg->clilen = sizeof(arg->cli_addr);
+		arg->clilen = sizeof (arg->cli_addr);
-		arg->sock = accept(sock_listen, (struct sockaddr *)&arg->cli_addr,
+		arg->sock = accept(sock_listen, (struct sockaddr *)&arg->cli_addr, &arg->clilen);
-				&arg->clilen);
 		if (arg->sock < 0) {
-			rig_debug(RIG_DEBUG_ERR, "accept: %s\n", strerror(errno));
+			handle_error (RIG_DEBUG_ERR, "accept");
 			break;
 		}
 
-		rig_debug(RIG_DEBUG_VERBOSE, "Connection opened from %s:%d\n",
+		if ((retcode = getnameinfo ((struct sockaddr const *)&arg->cli_addr, arg->clilen, host, sizeof (host)
-				inet_ntoa(arg->cli_addr.sin_addr),
+																, serv, sizeof (serv), NI_NOFQDN)) < 0)
-				ntohs(arg->cli_addr.sin_port));
+			{
+				rig_debug (RIG_DEBUG_WARN, "Peer lookup error: %s", gai_strerror (retcode));
+			}
+		rig_debug(RIG_DEBUG_VERBOSE, "Connection opened from %s:%s\n",
+							host, serv);
 
 #ifdef HAVE_PTHREAD
 		pthread_attr_init(&attr);
@@ -477,6 +541,8 @@ void * handle_socket(void *arg)
 	FILE *fsockin;
 	FILE *fsockout;
 	int retcode;
+	char host[NI_MAXHOST];
+	char serv[NI_MAXSERV];
 
 #ifdef __MINGW32__
 	int sock_osfhandle = _open_osfhandle(handle_data_arg->sock, _O_RDONLY);
@@ -513,9 +579,14 @@ void * handle_socket(void *arg)
 	}
 	while (retcode == 0 || retcode == 2);
 
-	rig_debug(RIG_DEBUG_VERBOSE, "Connection closed from %s:%d\n",
+	if ((retcode = getnameinfo ((struct sockaddr const *)&handle_data_arg->cli_addr
-				inet_ntoa(handle_data_arg->cli_addr.sin_addr),
+															, handle_data_arg->clilen, host, sizeof (host)
-				ntohs(handle_data_arg->cli_addr.sin_port));
+															, serv, sizeof (serv), NI_NOFQDN)) < 0)
+		{
+			rig_debug (RIG_DEBUG_WARN, "Peer lookup error: %s", gai_strerror (retcode));
+		}
+	rig_debug(RIG_DEBUG_VERBOSE, "Connection closed from %s:%s\n",
+						host, serv);
 
 	fclose(fsockin);
 	fclose(fsockout);