Re: libssh and python twisted conch ssh

[Johannes Krude <johannes@xxxxxxxx>]

hi,

On Tue, Jan 22, 2013 at 10:57:22AM +0100, Aris Adamantiadis wrote:
> I took a look at your pcap (next time please just attach it :)).
> It seems like twisted sends the key exchange packet right away before
> listening for the client's banner.
> As the packet is already buffered, the packet parsing is never triggered
> because it's waiting for socket input first.
The following fixes this behavior by repeatedly calling the data handler as
long as it takes data (https://git.aachen.ccc.de/~johannes/libssh/).

johannes


diff --git a/src/socket.c b/src/socket.c
index 6eab0aa..8569054 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -283,12 +283,15 @@ int ssh_socket_pollcallback(struct ssh_poll_handle_struct *p, socket_t fd, int r
                 return -1;
             }
 			if(s->callbacks && s->callbacks->data){
-				r= s->callbacks->data(buffer_get_rest(s->in_buffer),
-						buffer_get_rest_len(s->in_buffer),
-						s->callbacks->userdata);
-				buffer_pass_bytes(s->in_buffer,r);
-				/* p may have been freed, so don't use it
-				* anymore in this function */
+				r= 1;
+				while (r > 0) {
+					r= s->callbacks->data(buffer_get_rest(s->in_buffer),
+							buffer_get_rest_len(s->in_buffer),
+							s->callbacks->userdata);
+					buffer_pass_bytes(s->in_buffer,r);
+					/* p may have been freed, so don't use it
+					* anymore in this function */
+				}
 				p = NULL;
 			}
 		}