Merge pull request #3 from gaoxingliang/fixcisco

fix #1: some cisco devices is not supported
gaoxingliang · Oct 30, 2018 · 9a6319c · 9a6319c
2 parents 20c85a8 + d1f7481
commit 9a6319c
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Showing 3 changed files with 12 additions and 5 deletions.
diff --git a/pom.xml b/pom.xml
@@ -4,7 +4,7 @@
   <groupId>com.jcraft</groupId>
   <artifactId>jsch</artifactId>
   <packaging>jar</packaging>
-  <version>0.1.54</version>
+  <version>1.1.54</version>
   <name>JSch</name>
   <url>http://www.jcraft.com/jsch/</url>
   <description>JSch is a pure Java implementation of SSH2</description>

diff --git a/src/main/java/com/jcraft/jsch/Channel.java b/src/main/java/com/jcraft/jsch/Channel.java
@@ -251,10 +251,11 @@ private synchronized void init() throws java.io.IOException {
                 packet = new Packet(buffer);
 
                 byte[] _buf = buffer.buffer;
-                if (_buf.length - (14 + 0) - Session.buffer_margin <= 0) {
+                int margin = Session.buffer_margin_cisco;
+                if (_buf.length - (14 + 0) - margin <= 0) {
                     buffer = null;
                     packet = null;
-                    throw new IOException("failed to initialize the channel.");
+                    throw new IOException(String.format("failed to initialize the channel (remote maximum packet size %d, margin %d) ", rmpsize, margin));
                 }
 
             }
@@ -279,8 +280,8 @@ public void write(byte[] buf, int s, int l) throws java.io.IOException {
                 int _bufl = _buf.length;
                 while (l > 0) {
                     int _l = l;
-                    if (l > _bufl - (14 + dataLen) - Session.buffer_margin) {
-                        _l = _bufl - (14 + dataLen) - Session.buffer_margin;
+                    if (l > _bufl - (14 + dataLen) - Session.buffer_margin_cisco) {
+                        _l = _bufl - (14 + dataLen) - Session.buffer_margin_cisco;
                     }
 
                     if (_l <= 0) {

diff --git a/src/main/java/com/jcraft/jsch/Session.java b/src/main/java/com/jcraft/jsch/Session.java
@@ -129,6 +129,12 @@ public class Session implements Runnable {
             64 + // maximum mac length
             32;  // margin for deflater; deflater may inflate data
 
+    // in some cisco devices, the buffer is not so large
+    static final int buffer_margin_cisco = 32 + // maximum padding length
+            20 + // maximum mac length
+            32;  // margin for deflater; deflater may inflate data
+
+
     private java.util.Hashtable config = null;
 
     private Proxy proxy = null;