libvncclient: add ipv6 support

[jes: pulled the "host" declarations into the conditionally compiled
blocks where that variable is used. Also fixed non-IPv6 connections.]
Signed-off-by: Vic Lee <llyzs@163.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

configure.ac

@@ -697,6 +697,15 @@ if test "x$with_gnutls" != "xno"; then
 	fi
 fi
 
+# IPv6
+AH_TEMPLATE(IPv6, [Enable IPv6 support])
+AC_ARG_WITH(ipv6,
+[  --without-ipv6          disable IPv6 support],,)
+if test "x$with_ipv6" != "xno"; then
+	AC_CHECK_FUNC(getaddrinfo, AC_DEFINE(IPv6,1),
+		AC_CHECK_LIB(socket, getaddrinfo, AC_DEFINE(IPv6,1)))
+fi
+
 # Checks for header files.
 AC_HEADER_STDC
 AC_CHECK_HEADERS([arpa/inet.h fcntl.h netdb.h netinet/in.h stdlib.h string.h sys/socket.h sys/time.h sys/timeb.h syslog.h unistd.h])

libvncclient/rfbproto.c

@@ -363,8 +363,6 @@ IsUnixSocket(const char *name)
 rfbBool
 ConnectToRFBServer(rfbClient* client,const char *hostname, int port)
 {
-  unsigned int host;
-
   if (client->serverPort==-1) {
     /* serverHost is a file recorded by vncrec. */
     const char* magic="vncLog0.0";
@@ -399,12 +397,20 @@ ConnectToRFBServer(rfbClient* client,const char *hostname, int port)
   else
 #endif
   {
-    /* serverHost is a hostname */
-    if (!StringToIPAddr(hostname, &host)) {
-      rfbClientLog("Couldn't convert '%s' to host address\n", hostname);
-      return FALSE;
+#ifdef LIBVNCSERVER_IPv6
+    client->sock = ConnectClientToTcpAddr6(hostname, port);
+    if (client->sock == -1)
+#endif
+    {
+      unsigned int host;
+
+      /* serverHost is a hostname */
+      if (!StringToIPAddr(hostname, &host)) {
+        rfbClientLog("Couldn't convert '%s' to host address\n", hostname);
+        return FALSE;
+      }
+      client->sock = ConnectClientToTcpAddr(host, port);
     }
-    client->sock = ConnectClientToTcpAddr(host, port);
   }
 
   if (client->sock < 0) {
@@ -421,17 +427,23 @@ ConnectToRFBServer(rfbClient* client,const char *hostname, int port)
 
 rfbBool ConnectToRFBRepeater(rfbClient* client,const char *repeaterHost, int repeaterPort, const char *destHost, int destPort)
 {
-  unsigned int host;
   rfbProtocolVersionMsg pv;
   int major,minor;
   char tmphost[250];
 
-  if (!StringToIPAddr(repeaterHost, &host)) {
-    rfbClientLog("Couldn't convert '%s' to host address\n", repeaterHost);
-    return FALSE;
-  }
+#ifdef LIBVNCSERVER_IPv6
+  client->sock = ConnectClientToTcpAddr6(repeaterHost, repeaterPort);
+  if (client->sock == -1)
+#endif
+  {
+    unsigned int host;
+    if (!StringToIPAddr(repeaterHost, &host)) {
+      rfbClientLog("Couldn't convert '%s' to host address\n", repeaterHost);
+      return FALSE;
+    }
 
-  client->sock = ConnectClientToTcpAddr(host, repeaterPort);
+    client->sock = ConnectClientToTcpAddr(host, repeaterPort);
+  }
 
   if (client->sock < 0) {
     rfbClientLog("Unable to connect to VNC repeater\n");

libvncclient/sockets.c

@@ -336,6 +336,68 @@ ConnectClientToTcpAddr(unsigned int host, int port)
   return sock;
 }
 
+int
+ConnectClientToTcpAddr6(const char *hostname, int port)
+{
+#ifdef LIBVNCSERVER_IPv6
+  int sock;
+  int n;
+  struct addrinfo hints, *res, *ressave;
+  char port_s[10];
+  int one = 1;
+
+  if (!initSockets())
+	  return -1;
+
+  snprintf(port_s, 10, "%d", port);
+  memset(&hints, 0, sizeof(struct addrinfo));
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_socktype = SOCK_STREAM;
+  if ((n = getaddrinfo(hostname, port_s, &hints, &res)))
+  {
+    rfbClientErr("ConnectClientToTcpAddr6: getaddrinfo (%s)\n", gai_strerror(n));
+    return -1;
+  }
+
+  ressave = res;
+  sock = -1;
+  while (res)
+  {
+    sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+    if (sock >= 0)
+    {
+      if (connect(sock, res->ai_addr, res->ai_addrlen) == 0)
+        break;
+      close(sock);
+      sock = -1;
+    }
+    res = res->ai_next;
+  }
+  freeaddrinfo(ressave);
+
+  if (sock == -1)
+  {
+    rfbClientErr("ConnectClientToTcpAddr6: connect\n");
+    return -1;
+  }
+
+  if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
+		 (char *)&one, sizeof(one)) < 0) {
+    rfbClientErr("ConnectToTcpAddr: setsockopt\n");
+    close(sock);
+    return -1;
+  }
+
+  return sock;
+
+#else
+
+  rfbClientErr("ConnectClientToTcpAddr6: IPv6 disabled\n");
+  return -1;
+
+#endif
+}
+
 int
 ConnectClientToUnixSock(const char *sockFile)
 {

rfb/rfbclient.h

@@ -384,6 +384,7 @@ extern rfbBool WriteToRFBServer(rfbClient* client, char *buf, int n);
 extern int FindFreeTcpPort(void);
 extern int ListenAtTcpPort(int port);
 extern int ConnectClientToTcpAddr(unsigned int host, int port);
+extern int ConnectClientToTcpAddr6(const char *hostname, int port);
 extern int ConnectClientToUnixSock(const char *sockFile);
 extern int AcceptTcpConnection(int listenSock);
 extern rfbBool SetNonBlocking(int sock);