From 71dc6a3e9053d22ab6b0fe7a6e6960653813fcd0 Mon Sep 17 00:00:00 2001 From: Simon Rettberg Date: Fri, 15 May 2020 15:28:04 +0200 Subject: Check if remote host actually repies with RFB handshake --- src/main/java/de/bwlehrpool/bwlp_guac/AvailableClient.java | 11 ++++++++--- src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java | 6 ++++++ 2 files changed, 14 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/main/java/de/bwlehrpool/bwlp_guac/AvailableClient.java b/src/main/java/de/bwlehrpool/bwlp_guac/AvailableClient.java index 8798813..c60db10 100644 --- a/src/main/java/de/bwlehrpool/bwlp_guac/AvailableClient.java +++ b/src/main/java/de/bwlehrpool/bwlp_guac/AvailableClient.java @@ -161,18 +161,23 @@ public class AvailableClient implements Cloneable { if (now < this.lastConnectionCheck) { this.lastConnectionCheck = 0; } - if (now - this.lastConnectionCheck < 1000) + if (now - this.lastConnectionCheck < 2000) return this.connectionOk; for (;;) { try (VncConnection vnc = new VncConnection(this.clientip, 5900)) { - LOGGER.debug("VNC Version for " + this.clientip + " is " + vnc.handshake()); + String version = vnc.handshake(); + if (version == null) { + LOGGER.info("Host " + this.clientip + " doesn't speak RFB protocol"); + break; + } + LOGGER.debug("VNC Version for " + this.clientip + " is " + version); if (vnc.tryLogin(this.password)) { LOGGER.info("Connection to " + this + " is OK"); this.lastConnectionCheck = now; return this.connectionOk = true; } } catch (IOException e) { - LOGGER.info("Connection error VNC @ " + this, e); + LOGGER.info("Connection error VNC @ " + this); if (retries-- > 0) { try { Thread.sleep(1000); diff --git a/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java b/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java index 8bd4bd0..06a7013 100644 --- a/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java +++ b/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java @@ -36,9 +36,15 @@ public class VncConnection implements Closeable { in = new DataInputStream(sock.getInputStream()); } + /** + * @return Version string on success, null if not RFB + * @throws IOException + */ public String handshake() throws IOException { byte[] buffer = new byte[12]; in.readFully(buffer); + if (buffer[0] != 'R' || buffer[1] != 'F' || buffer[2] != 'B') + return null; out.write("RFB 003.008\n".getBytes()); out.flush(); return new String(buffer).substring(4, 11); -- cgit v1.2.3-55-g7522