Automatic disconnect protection for SSH terminals

A simple solution for a simple problem

I got tired a long time ago of losing what I was currently working on in SSH sessions when they were lost due to disconnects from network connectivity issues. To combat this I have been using screen when running sessions that I can absolutely not lose, but the problem still persists in other sessions or when I forgot to run it. The easy solution to this was to add screen to one of my bash init scripts (~/.bashrc [or ~/.bash_profile]) as follows:

if [ $TERM == "xterm" ]; then screen -R pts-0.`hostname` && exit; fi

This automatically makes the screen command run on bash user initialization unless already in screen (to prevent recursion). From there, 3 things can happen depending on how many detached screen sessions are currently available:

1. 0: A new session is created
2. 1: The session is attached
3. 2+: The sessions are listed and the user can attach to a specific session by running “screen -r ” followed by its process ID (listed before the “.pts-0”)

Edit on 2010-12-30 @ 3:50am: I changed != "screen" to == "xterm" because otherwise scp and some other non-term programs were failing. You may have to use something other than “xterm” for your systems.

Edit on 2010-1-24 @ 2:00pm: I added the exit; so the terminal automatically exits when the screen session closes.

iGoogle Security Problems

For a company that stresses security...

I’ve recently been having problems using the Google Reader widget in iGoogle. Normally, when I clicked on an RSS Title, a “bubble” popped up with the post’s content. However recently when clicking on the titles, the original post’s source opened up in a new tab. I confirmed the settings for the widget were correct, so I tried to remember the last change I made in Firefox that could have triggered this problem, as it seems the problem was not widespread, and only occurred to a few other people with no solution found. I realized a little bit back that I had installed the HTTPS Everywhere Firefox plugin. As described on the EFF’s site “HTTPS Everywhere is a Firefox extension ... [that] encrypts your communications with a number of major websites”.

Once I disabled the plugin and found the problem went away, I started digging through Google’s JavaScript code with FireBug. It turns out the start of the problem was that the widgets in iGoogle are run in their own IFrames (which is a very secure way of doing a widget system like this). However, the Google Reader contents was being pulled in through HTTPS secure channels (as it should thanks to HTTPS Everywhere), while the iGoogle page itself was pulled in through a normal HTTP channel! Separate windows/frames/tabs cannot interact with each other through JavaScript if they are not part of the same domain and protocol (HTTP/HTTPS) to prevent Cross-site scripting hacks.

I was wondering why HTTPS Everywhere was not running iGoogle through an HTTPS channel, so I tried it myself and found out Google automatically redirects HTTPS iGoogle requests to non secure HTTP channels! So much for having a proper security model in place...

So I did a lot more digging and modifying of Google’s code to see if I couldn’t find out exactly where the problem was occurring and if it couldn’t be fixed with a hack. It seems the code to handle the RSS Title clicking is injected during the “onload” event of the widget’s IFrame. I believe this was the code that was hitting the security privilege error to make things not work. I attempted to hijack the Google Reader widget’s onload function and add special privileges using “netscape.security.PrivilegeManager.enablePrivilege”, but it didn’t seem to help the problem. I think with some more prodding I could have gotten it working, but I didn’t want to waste any more time than I already had on the problem.

The code that would normally be loaded into the widget’s IFrame window hooks the “onclick” event of all RSS Title links to both perform the bubble action and cancel the normal “click” action. Since the normal click action for the anchor links was not being canceled, the browser action of following the link occurred. In this case, the links also had a “target” set to open a new window/tab.

There is however a “fix” for this problem, though I don’t find it ideal. If you edit the “extensions\https-everywhere@eff.org\chrome\content\rules\GoogleServices.xml” file in your Firefox profile directory (most likely at “C:\Users\USERNAME\AppData\Roaming\Mozilla\Firefox\Profiles\PROFILENAME\” if running Windows 7), you can comment out or delete the following rule so Google Reader is no longer run through secure HTTPS channels:

<rule from="^http://(www\.)?google\.com/reader/" 
to="https://www.google.com/reader/"/>

That being said, I’ve been having a plethora of problems with Facebook and HTTPS Everywhere too :-\ (which it actually mentions might happen in its options dialog). You’d think the largest sites on the Internet could figure out how to get their security right, but either they don’t care (the more likely option), or they don’t want the encryption overhead. Alas.

Visual Studio IDE Tab Order

Microsoft fails at usability

I’ve been really annoyed for a while by the unintuitive IDE tab ordering in Visual Studio 2005+. When you type [shift+]alt+tab, you don’t get the next/previous tab in the list as would be the OBVIOUS way to do it (which probably all other IDEs do this right). No, it switches between tabs in an arbitrary hidden order related to the last acces order of the tabs.

Searching the internet for a solution to this was pretty fruitless, so I tried to tackle the problem myself. I dug through all the possible structures I could find in the Visual Studio IDE macro explorer, and was unfortunately unable to find where the tab order was kept in a window pane (if it is even accessible to the user). I thought I had the solution at one point, but realized it also just switches tabs in the order they were originally opened :-(. This is the VB macro code I came up with to do at least that, which uses “DTE.ActiveWindow.Document.Collection” for the tab-open order.

	 Public Sub TabDirection(ByVal Direction As Integer)
		  'Find the index of the current tab
		  Dim i As Integer
		  Dim Index As Integer
		  Dim Count As Integer
		  Count = DTE.ActiveWindow.Document.Collection.Count
		  For i = 1 To Count
				If DTE.ActiveWindow.Document.Collection.Item(i).ActiveWindow.Equals(DTE.ActiveWindow) Then Index = i
		  Next i

		  'Determine the new index
		  Index = Index + Direction
		  If Index > Count Then Index = 1
		  If Index = 0 Then Index = Count

		  DTE.ActiveWindow.Document.Collection.Item(Index).Activate() 'Activate the next tab in the proper direction
	 End Sub

	 Public Sub TabForward()
		  TabDirection(1)
	 End Sub

	 Public Sub TabBackward()
		  TabDirection(-1)
	 End Sub

Live Streaming SHOUTcast through Flash

The one time I decide to look online before trying it out myself

A client of mine wanted their website to have an applet that played streaming music from a SHOUTcast server. The easy solution would have been to just embed a Windows Media Player applet into the page, but that would only work for IE.

I thoroughly searched the web and was unable to find a Flash applet (or other solution) that already did this (and actually worked). Most of the information I was finding was people having problems getting this kind of thing working in Flash with no answer provided. After giving up on finding a resolution online, I decided to load up Flash and see what I could find from some tinkering.

Quite frankly, I’m shocked people were having so many problems with this. I started an ActionScript 2.0 project and put in the following code, and it worked right away in Flash CS3 (v9.0) with no problem:

var URL="http://example.shoutcast.castledragmire.com:1234/" //The URL to the SHOUTcast server
var MySound:Sound=new Sound(this);
MySound.loadSound(URL,true);

Unfortunately, once I exported the Flash applet and loaded it up in my browsers, it was no longer working. After a few minutes of poking around, I had a hunch that the SHOUTcast host might be sending different data depending on the [Browser’s] User Agent. I changed Firefox’s User Agent to “Flash” through a Firefox add-on (User Agent Switcher), and it worked :-D.

Once again, unfortunately, this was not a viable solution because I couldn’t have every user who visited the client’s web page change their browser User Agent string :-). The quickest solution at this point to the problem was to just create a passthrough script that grabbed the live stream on their server and passed it to the client. The following is the PHP script I used for this:

$streamname='example.shoutcast.castledragmire.com';
$port      ='1234';
$path      ='/';

header('Content-type: audio/mpeg');
$sock=fsockopen($streamname,$port);
fputs($sock, "GET $path HTTP/1.0\r\n");
fputs($sock, "Host: $streamname\r\n");
fputs($sock, "User-Agent: WinampMPEG/2.8\r\n");
fputs($sock, "Accept: */*\r\n");
fputs($sock, "Connection: close\r\n\r\n");
fpassthru($sock);
fclose($sock);

The final two steps to get this working were:

1. Setting the Flash Applet’s URL variable to the PHP file
2. Turning off PHP output buffering for the file. This can only be done through Apache or the php.ini depending on the server setup. This is very important, as if it’s on, the data will never get sent to the user.

The only problem with this method is that it taxes the server that is passing the data through, especially since it uses PHP... This kind of thing could very easily be done in C though (as a matter of fact, I will be writing a post on something very close to that very soon).

Focus Follows Mouse

Active Window Tracking in Windows

A friend of mine who mainly works in Linux is always frustrated when he has to deal with working in Windows and doesn’t have FFM (Focus Follows Mouse). FFM means focusing a window when the mouse cursor moves over it (rollover), preferably without raising the window’s z-order position. I told him I’d throw together a program that did this, but my original approach was problematic.

My original approach was to use LowLevelMouseProc (WinAPI:SetWindowsHookEx), which is the same basic approach as my HalfKey project. Whenever a non-focused window (WinAPI:GetActiveWindow) is moused over (WinAPI:WindowFromPoint), it would activate it (gain the focus) (WinAPI:SetWindowLong/WinAPI:SetForegroundWindow). Unfortunately, as I found out, Windows is specifically designed to make an activated window go to the top of the z-order, and there is no way around this. The only solution I could find was recording the original position of the activated window (WinAPI:GetParent) and restoring it after the operation. This was however less than optimal :-(.

After some additional research on the topic, I found out the FFM functionality is actually built into Windows through a little known “System Parameter” (WinAPI:SystemParametersInfo). Microsoft calls it “Active Window Tracking”. Below is the code to the FocusFollowsMouse.exe (command line executable) to activate this system feature (the executable can be run without the command line and it will use the default options).

FocusFollowsMouse program information:
Turns on active window tracking in Windows
Parameters:

• -h The help screen (cancels further actions)
• -i installs new settings permanently
• -d disables active window tracking
• -r raise the window when focusing

//Toggles active window tracking, with options
#include <windows.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
	BOOL SendUpdate=SPIF_SENDCHANGE; //How to send the update to the system. Default is to only send to the system, but not make the change permanent
	BOOL TurnOn=TRUE; //By default we are turning on the option
	BOOL RaiseWindow=FALSE; //Whether to raise the window that is gaining the focus
	int i;

	//Read in options
	for(i=1;i<argc;i++)
	{
		if(argv[i][0]!='-') //Parameters must start with a -
			continue;
		switch(argv[i][1]) //Execute a valid action on the first character. Characters after it are ignored
		{
			case 'h': //Help  screen
				printf("%s", "Turns on active window tracking in Windows\n"
					"-h this help screen (cancels further actions)\n"
					"-i installs new settings permanently\n"
					"-d disables active window tracking\n"
					"-r raise the window when focusing\n");
					return 0; //Cancel further actions
			case 'i': //Install permanently
				SendUpdate|=SPIF_UPDATEINIFILE; //Writes the new system-wide parameter setting to the user profile.
				break;
			case 'd': //Turn off76
				TurnOn=FALSE;
				break;
			case 'r': //Raise the window
				RaiseWindow=TRUE;
				break;
		}
	}

	//Execute the system parameters change
	SystemParametersInfo(SPI_SETACTIVEWINDOWTRACKING, 0, (PVOID)TurnOn, SendUpdate);
	SystemParametersInfo(SPI_SETACTIVEWNDTRKZORDER, 0, (PVOID)RaiseWindow, SendUpdate);

	return 0;
}

Telnet Workaround

I hate not having root ^_^;

I recently had to do some work on a system where I was not allowed SSH/telnet access. Trying to do work strictly across ftp can take hours, especially when you have thousands of files to transfer, so I came up with a quick solution in PHP for simple command line access.

<form method=post action="exec.php">
	<table style="height:100%;width:100%">
		<tr><td height="10%">
			<textarea name=MyAction style="height:100%;width:100%"><?=(isset($_REQUEST['MyAction']) ? $_REQUEST['MyAction'] : '')?></textarea>
		</td></tr><tr><td height="90%">
			<textarea name=Output style="height:100%;width:100%"><?
if(isset($_REQUEST['MyAction']))
{
	$MyAction=preg_split("/\\r?\\n/", $_REQUEST['MyAction']);
	foreach($MyAction as $Action)
	{
		exec($Action, $MyOutput);
		print htmlentities(implode("\n", $MyOutput), ENT_QUOTES, 'ISO8859-1')."\n-----------------------\n";
	}
}
			?></textarea>
		</td></tr><tr><td height=1>
			<input type=submit>
		</td></tr>
	</table>
</form>

This code allows you to enter commands on separate lines in the top box, and after the form is submitted, the output of each command is entered into the bottom box separated by dashed lines.

Note that between each command the environment is reset, so commands like "cd" which change the current directory are not useable :-(. You must also change the line 'action="exec.php"' to reflect the name you give the file.

A more suitable solution would be possible through AJAX and a program that redirected console output from a persistent session, but this was just meant as quick fix :-).

Winamp Problems

Adding features also potentially adds bugs

I’ve been getting tired of Winamp (v5.112 specifically) randomly crashing for no specific reason on my new home music server. I tried upgrading to the latest version, but it also crashes. The best solution at this point was to just downgrade to an old version, like v2.8, which I have been using for more years than I can remember on most all of my machines.

Old versions of Winamp have a pretty low footprint and are great at what they are supposed to do: playing music. It’s gotten bloated nowadays though, which often happens when great software has hit its peak and has nowhere to go. This is one reason to just keep using versions of software that you are used to and have no problems with; like using XP instead of Windows Vista, or some older versions of Microsoft Office, pre-2003. Newer does not always mean better!

Legacy Geocities Login Problems

Big corporations refusing to acknowledge that they have problems, let alone fix them

I have a friend that has a legacy Geocities (the MySpace of the 1990s for free web hosting) account (one from who knows how long before GeoCities was bought by Yahoo). The control panel (at geocities.yahoo.com/gcp) won’t allow logging in to his legacy account because it gets stuck in an infinite redirect loop, redirecting right back to itself.

My guess is that the problem has to do with cookies (on Geocities’ servers’ side, not the client’s!), but I didn’t get that far, as I found a roundabout solution to his problem. After logging in, the user can go to http://geocities.yahoo.com/filemanager or http://geocities.yahoo.com/v/fm.html to manage their files. While the rest of the control panel is still not accessible, this was enough of a solution for him.

Reports are that Yahoo refuses to respond about this problem with their servers.

Microsoft IIS Bug

Bad Programming: Only using file extensions as an indicator

According to a Microsoft KB article titled “Virtual directory names with executable extensions are not used correctly”, using a virtual folder ending in an executable extension (like .com, .exe, .dll, or .sh) under the web server for IIS [Microsoft’s Internet information services server suite] makes the contents inside the folder unviewable. This behavior itself is kind of silly, as you’d assume a web server would always check to see if something was a file or folder first.

Unfortunately, this doesn’t apply to just virtual folders, but all folders under an IIS web server, as I found out a few years ago when I backed up a site that I knew would be taken down very soon (ironically, because the company [SysInternals] was being taken over by Microsoft) and mirrored it on my Home Server, which runs IIS.

The solution I used was to add a character (in my case an underscore “_”) to the end of all the directory names ending in “.com” and then doing a global regular expression replace through all files in the mirror to replace any occurrences of these directories.

Search For: “(DOMAIN1|DOMAIN2|DOMAIN3)([\\/])”
Replace With: “$1_/$2”

I still plan on getting up some site mirrors of places that no longer exist and such for the miscellaneous section one of these days...

Windows Hosts File

When DNS decides to be finicky

Another of my favorite XP hacks is modifying domain addresses through XP’s Hosts file. You can remap where a domain points on your local computer by adding an IP address followed by a domain in the “c:\windows\system32\drivers\etc\hosts” file.

Domain names are locally controlled, looked up, and cached on your computer at the OS level, so there are simple hacks like this for other OSs too.

I often utilize this solution as a server admin who controls a lot of domains (Over 100, and I control most of them at the registrar level too ^_^). The domain system itself across the web is incredibly fastidious and prone to problems if not perfectly configured, so this hack is a wonderful time saver and diagnostic tool until things resolve and work properly.

Computers are Evil

Setting up new computers can be quite the hassle

The new home server for the new entertainment center I recently set up has made itself out to be quite a nuisance. I am unsure as to whether I will keep using it or not, but fortunately, I have not yet taken down my old home server, as I wanted to do some break in testing on the new one first.

Setting up new computers is almost always a pain in the ass, what with installing and configuring all the software from scratch (which always includes a format and new OS), and making sure all the hardware works properly and finding drivers for it (sometimes when you don’t even have the proper information on what that hardware is). But sometimes, computers can go above and beyond the normal setup nuances and annoyances and be downright evil. I have long proclaimed to people that computers have personalities and minds of their own and they decide when and where they want to be accommodating or uncooperative. Besides all the normal computer setup problems (including not knowing what the hardware was and having to figure that out), this one also had a few more doozies.

The first big problem started with the fact that I wanted to use this computer for video output, and it does not have an AGP slot. As I contemplated in the previous post on this topic, I went ahead and bought a PCI Geforce 5200 for $27.79 including shipping. The card did not fit properly in the new case, so I had to unscrew a few things, which were fortunately designed for just that reason. Then the big problem came up in that video outputted from the s-video port on the card showed up on the TV at a 50% over zoom, so I couldn’t see half the screen. I couldn’t test the monitor output port either because it is DVI, and I have no DVI monitors, alas. After 2 or 3 hours of tinkering with it and throwing everything plus the kitchen sink at the problem, including trying a different s-video cable, I finally stumbled on the solution and got it working, yay. That is... until after I rebooted and it wasn’t working again x.x;. Another 20 or so more minutes of tinkering got it fixed again, and I was able to quickly hone down on a procedure to fix the problem on the next reboot, optimizing it with each successive reboot over the next few days. The procedure is as follows: (The TV over s-video starts as the primary monitor, and I have a second monitor connected to the VGA port to the onboard graphics card)

• Open “Display Properties” [Right click Desktop > Properties] > Settings
• Attach second monitor so I can see what I’m doing
• Open NVidia Control Panel
• Rotate screen to 90 degrees. It only wants to rotate the screen at 1024x768, which is too high a resolution for the TV, so it kicks the resolution down to 640x480 while rotating
• Keep setting the screen to no rotation (0 degrees) until the scaling is correct [usually twice]. The NVidia control panel doesn’t want to allow going back to normal rotation now due to the 1024x768 required resolution thing, and will keep the setting set as 90 degrees, so the process can easily be repeated until it works.
• Now that the screen is at the correct scale (at 640x480), all that’s left is to get the rotation back to normal. To do this, immediately after accepting the rotation process in the NVidia Control Panel, it has to be closed out (alt+f4) so that it saves the rotation setting at 0 degrees but doesn’t try to set it back after all the resolution changes.
• Raise the resolution back to 800x600
• Detach secondary monitor now that it is no longer needed

The screen still unfortunately has about 100-200 “pixels” (monitors don’t have pixels, technically) on the top and bottom of the screen that are unused, but eh, NBD. At least this graphics card lets me properly pan and scan (zoom/scale and move) the s-video output around unlike my Geforce4 Ti 4600! The next problem with the video card is that some video outputted from it is just too slow. Though most content is watchable, the choppiness makes it unbearable. The problem with this might just be that the PCI bus doesn’t have the required throughput, which is why most video cards are used over AGP (or nowadays PCI express).

There are even two more final problems with it, one a possible deal killer, the other rather insignificant. The unimportant problem is that XP refuses to install updates. I believe this to be a problem with SP3. The final problem is that the computer seems to randomly compltely freeze up every now and then for no particular reason, requiring a reboot. This has happened 2 or 3 times so far, so I’m waiting to see how often it happens, if anymore. I know it’s not overheating as I currently have the case open; and I see no blown capacitors... hmmmm...

<frustration>Computers!</frustration>

Video Game Nostalgia

And Metal Gear Solid Problems

So a comic [Gunnerkrigg Court] that I enjoy and read daily [updates MWF] recently referenced Metal Gear Solid, which finally made me decide to play through the series.

For reference, whenever I bring up games from here on out, it’s usually to talk about encountered problems, which I will usually provide fixes for, or technical aspects of the game. I’m not qualified, or funny enough, to want to review games; and that is not the purpose of my postings here.

The first thing I wanted to mention is a fix for a graphical problem. As the game is rather “old” (released in 2000 for Windows), it can be incompatible with modern systems. One of the options it uses in hardware mode is 8-bit textures, which is no longer supported, though for the life of me I can’t see why a hack could be made in the video card drivers for this problem. Because of this, the game only allows you to run in software mode. After a lot of digging and searching, in which every place said the same thing (it’s not fixable), I finally found a hacked executable [Metal Gear Solid v1.0 [ENGLISH] No-CD/WinXP+Vista+GeForce+ATi Fixed EXE] made by a kind sole to fix the problem.

Another problem which really frustrated me was a “puzzle” in the game referring to looking for information on the “back of the CD case”. I had just received an “optical disk” in the game, however, it appeared to be a floppy disk and no matter what I did I couldn’t find the required information with the item. I figured it must have been a bug and finally gave in and looked it up online. It turns out they meant the actual CD case the game came in had a number [radio frequency] written on the back of it - “140.15”. I can only assume they did this as a means of “copy protection” to frustrate anyone who didn’t actually buy the game. Unfortunately, I acquired the game without a CD case so I was frustrated by this myself.

This kind of system reminded me of the very old days of gaming in which some games asked you to input a certain word from a certain paragraph on a certain page of the manual to enter the game, or asked questions with answers found in the manual. One of the games I had that did the former was Teenage Mutant Ninja Turtles [1989] for DOS. I have fond memories of playing this and a (monochrome? [green and black :-) ] IIRC?) version of Muppet Adventure: Chaos at the Carnival [1989] (Dear Thor! heh) [also a DOS game] as they were, IIRC, two of my first video games, though I got many others around that time. Both games had later released NES ports too.

My real favorite childhood games however, which are still both cult classics, were Doom, which got me into the design aspect of making games, and most importantly, ZZT, which is what really got me started on programming in 1991 at the age of 5. I still have the original floppy disks for ZZT too :-). ZZT was more scripting than programming though, and I didn’t start real programming until I got into QBasic in 1993. I might release some of my creations for these games one of these days for nostalgic sake ^_^;. I also remember thoroughly enjoying Star Trek: 25th Anniversary for DOS in 1992 :-). I was a nerd even as a kid! ^_^; This game also had copy protection I had forgotten about. As Wikipedia tells:

The game had a copy-protection system in that the player was forced to consult the game’s manual in order to find out which star system they were supposed to warp to on the navigation map. Warping to the wrong system would send them into either the Klingon or Romulan neutral zones, and initiate an extremely difficult battle that often ends with the destruction of the Enterprise.

[Edit 8/16/2008 @ 10:05pm] Pictures of some of this stuff can be found in tomorrow’s post, “Ancient Software”.

Multiple Windows XP Sessions

Making XP act like Windows Server

All of the Windows lines of OSs from XP through Windows Server 2003 (or 2005 or 2007?) are, to my knowledge and IMO, basically the exact same thing, with just some minor tweaks and extra software for the more expensive versions. My version of XP Professional even comes with IIS (Internet Information Services - Microsoft’s web/ftp/mail server suite). One of my favorite XP hacks adds on a desperately needed functionality found only in Windows Server editions, which is allowing multiple user sessions on a machine at once. This basically means allowing multiple people to log onto a machine at the same time through Remote Desktop (Microsoft’s internal Windows VNC client). I find the most useful function by far of this is the “Remote Control” feature, which allows a second logged in user to see exactly what is on the screen of another session, and if permissions are given, to take control of it. This is perfect for those people whom you often have to trouble shoot computer problems for, eliminating the need for a trip to their location or 3rd party software to view their computer.

This hack requires a few registry modifications, a group policy modification, and a DLL replacement. The DLL replacement was provided by Microsoft in early versions of XP SP2 when they were tinkering with allowing this feature in XP. I found the information for all this here a number of years ago and it has provided itself invaluable since. Unfortunately, this does not work on XP Home edition, just XP Professional. I tried adapting it once and wasted a lot of time :-\. The following is the text from where I got this hack.

Concurrent Remote Desktop Sessions in Windows XP SP2

I mentioned before that Windows XP does not allow concurrent sessions for its Remote Desktop feature. What this means is that if a user is logged on at the local console, a remote user has to kick him off (and ironically, this can be done even without his permission) before starting work on the box. This is irritating and removes much of the productivity that Remote Desktop brings to Windows. Read on to learn how to remove that limitation in Windows XP SP2

A much touted feature in SP2 (Service Pack 2) since then removed was the ability to do just this, have a user logged on locally while another connects to the terminal remotely. Microsoft however removed the feature in the final build. The reason probably is that the EULA (End User License Agreement) allows only a single user to use a computer at a time. This is (IMHO) a silly reason to curtail Remote Desktop’s functionality, so we’ll have a workaround.

Microsoft did try out the feature in earlier builds of Service Pack 2 and it is this that we’re going to exploit here. We’re going to replace termsrv.dll (The Terminal Server) with one from an earlier build (2055).

To get Concurrent Sessions in Remote Desktop working, follow the steps below exactly:

1. Download the termsrv.zip file and extract it somewhere.
2. Reboot into Safe Mode. This is necessary to remove Windows File Protection. [Dakusan: I use unlocker for this, which I install on all my machines as it always proves itself useful, and then usually have to do a “shutdown -a” from command line when XP notices the DLL changed.]
3. Copy the termsrv.dll in the zip to %windir%\System32 and %windir%\ServicePackFiles\i386. If the second folder doesn’t exist, don’t copy it there. Delete termsrv.dll from the dllcache folder: %windir%\system32\dllcache
4. Merge the contents of Concurrent Sessions SP2.reg file into the registry. [Dakusan: Just run the .reg file and tell XP to allow the action.]
5. Make sure Fast User Switching is turned on. Go Control Panel -> User Accounts -> Change the way users log on or off and turn on Fast User Switching.
6. Open up the Group Policy Editor: Start Menu > Run > ‘gpedit.msc’. Navigate to Computer Configuration > Administrative Templates > Windows Components > Terminal Services. Enable ‘Limit Number of Connections’ and set the number of connections to 3 (or more). This enables you to have more than one person remotely logged on.
7. Now reboot back into normal Windows and try out whether Concurrent Sessions in Remote Desktop works. It should!

If anything goes wrong, the termsrv_sp2.dll is the original file you replaced. Just rename it to termsrv.dll, reboot into safe mode and copy it back.

The termsrv.dl_ file is provided in the zip is for you slipstreamers out there. Just replace that file with the corresponding file in the Windows installation disks.

I have included an old copy of the above web page, from when I first started distributing this, with the information in the hack’s zip file I provide.

If you want to Remote Control another session, I think the user needs to be part of the “Administrators” group, and don’t forget to add any users that you want to be able to remotely log on to the “Remote Desktop Users” group.

This is all actually part of an “Enhanced Windows XP Install” document I made years ago that I never ended up releasing because I hadn’t finished cleaning it up. :-\ One of these days I’ll get it up here. Some of the information pertaining to this hack from that document is as follows:

• Any computer techy out there that has tried to troubleshoot over the phone knows how much of a problem/pain in the anatomy it is, and for this reason, I install this hack which makes it painless to automatically connect to a users computer through remote desktop, which can then be remotely viewed or controlled via their displayed console session.
• I often use this hack myself when I am running computers without keyboards/mice, like my entertainment computer. For a permanent solution for something like this though, I recommend a KM (Keyboard/Mouse) solution like synergy, which allows manipulating one computer via a keyboard and mouse on another.
• Your user account password must also not be blank. Blank passwords often cause problems with remote services.
• The security risk for this is a port is opened for someone to connect to like telnet or SSH on Unix, which is a minimal risk unless someone has your username+password.
• You have to have a second username to log into, which can be done under Control Panel > User Accounts, or Control panel > Administrative Tools > Computer Management > System Tools > Local users and Groups.
• If you want the second user to be able to log in remotely, make sure to add them under Control Panel > System > Remote > Select Remote users, and also check “allow users to connect remotely to this computer”.
• You also need to know the IP address of the user’s computer you want to connect to, and unfortunately, they are not always static. If you run into this, you may want to use a DDNS service like mine.
• You may also run into the unfortunate circumstance of NAT/Firewalled networks, which is beyond the scope of this document. Long story short, you need to open up port 3389 in the firewall and forward it through the router/NAT (this is the port for both remote desktop and remote assistance).
• You may also want to change the port number to something else so a port scanner will not pick it up. To connect to a different port, on the client computer, in remote desktop, you connect to COMPUTERIP:PORT like www.mycomputer.com:5050.
  • Registry Key: HKLM\System\CurrentControlSet\Control\TerminalServer\WinStations\RDP-Tcp\PortNumber - Set as your new port number
  • This requires a reboot to work.
  • Make sure you don’t provide a port that’s already used on the computer, and you probably shouldn’t make it a standard port either [21 [ftp], 25 [smtp], 80 [http], etc])
• You can also log into their current console session by going to the task manager (ctrl+shift+esc in full screen, or right click taskbar and go to “task manager”) > Users > Right click username > Remote control
  • This will ask the user at the computer if they want to accept this. To have it NOT ask them, do the following:
    • Start > Run > gpedit.msc [enter] > computer configuration > administrative templates > windows components > terminal services
    • Double click the option “Sets rules for remote control of terminal services user sessions”
    • Enable it, and for the “Options” setting, set “Full control without users permission”
• If the ability for you to access a client’s computer without their immediate permission or knowledge is too “dangerous” for their taste, you may suggest/use Remote Assistance, which is more troublesome, but much more “secure” sounding.

Windows 98 for VMWare

I recently had to install Windows 98 through VMWare for some quick tests, and there were a few minor problems after the install that needed to be resolved. I thought I’d share them here if anyone ever needed them.

• First, VMWare Tools needs to be installed to get video and some other drivers working.
• Second, Windows 98 was really before the time when network cards were used to connect to the internet, as broadband technology was rare and modems were the commonplace solution, so it doesn’t make this process easy. To connect through your VMWARE bridge or NAT to the Internet (to use IE - FireFox [newer versions of?] doesn’t work on Windows 98), the following must be done through the MSN Connection Wizard (this is mostly from memory).
  • Open "Connect to the internet" from the desktop
  • Click Next
  • Select Modem Manually [next]
  • Select any of the normal modems in the list on the right, like a generic 56,000 modem [OK]
  • Click Next
  • Click lan/manual
  • Connect using my local area network (LAN) [next]
  • Click Next
  • "No" to email [next]
  • Click Finish
• Lastly, the default sound driver does not work, so you need to do the following [Information found here by googling]
  • Install the Create Lab’s drivers for the PCI sound card
  • Add the following lines to your VMWare config (vmx) file
    • pciSound.DAC1InterruptsPerSec = 0
    • pciSound.DAC2InterruptsPerSec = 0
  • Optionally, for a better midi waveset, download Creative Lab’s 8mb GM/GS Waveset [version 5] and select it for use in the device’s properties by:
    • Right click my computer
    • Select properties
    • Select the Device Manager tab
    • Find the area for sound and go to “SB PCI(WDM)”
    • Go to the second tab
    • Change the Midi Synthesizer Waveset to the downloaded eapci8m.ecw

Video driver woes

TV output issues

So I’ve recently switched over to an old Geforce4 Ti 4600 for TV output on my home server/TV station. Unfortunately, my TV needs output resizing (underscan) due to being dropped a long ways back during transport from a Halo game, and the CRT output is misaligned.

If I recall, old Nvidia drivers allowed output resizing, but the latest available ones (which are rather old themselves, as NVidia stops supporting old cards with newer driver sets that have more options) that work for my card only allow repositioning of the output signal, so part of the screen is cut off.

The final solution was to tell VLC media player to output videos at 400:318 aspect ratio when in full screen to force a smaller width that I could then reposition to properly fit the screen. A rather inelegant solution, but it works. One of these days I’ll get myself a new TV :-).