From 89d1c88bcf652d9afdf68b6a82be245040604f8f Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Sun, 18 Mar 2012 03:23:58 -0400
Subject: [PATCH] More robust option parsing and redo wrapper

---
 scripts/mosh                | 11 +++++------
 src/frontend/mosh-server.cc |  3 +++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/scripts/mosh b/scripts/mosh
index d6ceac0..9a8ad08 100755
--- a/scripts/mosh
+++ b/scripts/mosh
@@ -170,14 +170,13 @@ if ( $pid == 0 ) { # child
   open STDERR, ">&", $pty_slave->fileno() or die;
   close $pty_slave;
 
-  my $s;
+  my @server = ( $server, 'new', '-s' );
+
   if ( defined $port_request ) {
-    $s = q{sh -c 'MOSH_PORT=$1; shift; MOSH_IP=`set -- $SSH_CONNECTION; echo $3`; exec "$@" $MOSH_IP $MOSH_PORT' -- } . $port_request . ' ' . $server;
-  } else {
-    # retain compatibility with older server when no port requested
-    $s = q{sh -c 'exec "$@" "`set -- $SSH_CONNECTION; echo $3`"' -- } . $server;
+    push @server, ( '-p', $port_request );
   }
-  exec 'ssh', '-S', 'none', '-o', "ProxyCommand=$0 --fake-proxy -- %h %p", '-t', $userhost, '--', $s;
+
+  exec 'ssh', '-S', 'none', '-o', "ProxyCommand=$0 --fake-proxy -- %h %p", '-t', $userhost, '--', @server;
   die "Cannot exec ssh: $!\n";
 } else { # server
   my ( $ip, $port, $key );
diff --git a/src/frontend/mosh-server.cc b/src/frontend/mosh-server.cc
index f4b8898..0320c4d 100644
--- a/src/frontend/mosh-server.cc
+++ b/src/frontend/mosh-server.cc
@@ -80,6 +80,7 @@ string get_SSH_IP( void )
   char *SSH_writable = strdup( SSH_CONNECTION );
   fatal_assert( SSH_writable );
   strtok( SSH_writable, " " );
+  strtok( NULL, " " );
   const char *local_interface_IP = strtok( NULL, " " );
   fatal_assert( local_interface_IP );
   return string( local_interface_IP );
@@ -139,12 +140,14 @@ int main( int argc, char *argv[] )
   /* Sanity-check arguments */
   if ( desired_ip
        && ( strspn( desired_ip, "0123456789." ) != strlen( desired_ip ) ) ) {
+    fprintf( stderr, "%s: Bad IP address (%s)\n", argv[ 0 ], desired_ip );
     print_usage( argv[ 0 ] );
     exit( 1 );
   }
 
   if ( desired_port
        && ( strspn( desired_ip, "0123456789" ) != strlen( desired_ip ) ) ) {
+    fprintf( stderr, "%s: Bad UDP port (%s)\n", argv[ 0 ], desired_port );
     print_usage( argv[ 0 ] );
     exit( 1 );
   }