.NET Library for Client/Server application? - c#

I have a plan to write a small "Network manager" for my company using C#. It like a chat application. Please see example bellow:
Ex: Client(C) is manager, Server(S)
C: send string "is_process_running x.exe" (check x.exe is running on server pc)
S: check and send to C: "x.exe is running\nPath: 'C:\\windows\system32\x.exe'"
C: "kill_process_with_warning x.exe"
S: Show a message "Administrator detected you 're running a program that disallowed on computer. It will be kill in 10 seconds" and S kill process x.exe. Reply to C: "process killed!"
C: "disconnect"
...
...
...
I finding library for that. Please tell me something you know about that.
Thanks !

Use a TcpClient and TcpListener.

Is there any reason you wouldn't use WCF?
It may be an overkill for what you described here, but such apps are bound to grow in order to add funcionality.
It does have a great lot of abilities, but here's a quickstart guide.

Related

Remote monitor directory via FileSystemWatcher [duplicate]

Suppose some Windows service uses code that wants mapped network drives and no UNC paths. How can I make the drive mapping available to the service's session when the service is started? Logging in as the service user and creating a persistent mapping will not establish the mapping in the context of the actual service.
Use this at your own risk. (I have tested it on XP and Server 2008 x64 R2)
For this hack you will need SysinternalsSuite by Mark Russinovich:
Step one:
Open an elevated cmd.exe prompt (Run as administrator)
Step two:
Elevate again to root using PSExec.exe:
Navigate to the folder containing SysinternalsSuite and execute the following command
psexec -i -s cmd.exe
you are now inside of a prompt that is nt authority\system and you can prove this by typing whoami. The -i is needed because drive mappings need to interact with the user
Step Three:
Create the persistent mapped drive as the SYSTEM account with the following command
net use z: \\servername\sharedfolder /persistent:yes
It's that easy!
WARNING: You can only remove this mapping the same way you created it, from the SYSTEM account. If you need to remove it, follow steps 1 and 2 but change the command on step 3 to net use z: /delete.
NOTE: The newly created mapped drive will now appear for ALL users of this system but they will see it displayed as "Disconnected Network Drive (Z:)". Do not let the name fool you. It may claim to be disconnected but it will work for everyone. That's how you can tell this hack is not supported by M$.
I found a solution that is similar to the one with psexec but works without additional tools and survives a reboot.
Just add a sheduled task, insert "system" in the "run as" field and point the task to a batch file with the simple command
net use z: \servername\sharedfolder /persistent:yes
Then select "run at system startup" (or similar, I do not have an English version) and you are done.
You'll either need to modify the service, or wrap it inside a helper process: apart from session/drive access issues, persistent drive mappings are only restored on an interactive logon, which services typically don't perform.
The helper process approach can be pretty simple: just create a new service that maps the drive and starts the 'real' service. The only things that are not entirely trivial about this are:
The helper service will need to pass on all appropriate SCM commands (start/stop, etc.) to the real service. If the real service accepts custom SCM commands, remember to pass those on as well (I don't expect a service that considers UNC paths exotic to use such commands, though...)
Things may get a bit tricky credential-wise. If the real service runs under a normal user account, you can run the helper service under that account as well, and all should be OK as long as the account has appropriate access to the network share. If the real service will only work when run as LOCALSYSTEM or somesuch, things get more interesting, as it either won't be able to 'see' the network drive at all, or require some credential juggling to get things to work.
A better way would be to use a symbolic link using mklink.exe. You can just create a link in the file system that any app can use. See http://en.wikipedia.org/wiki/NTFS_symbolic_link.
There is a good answer here:
https://superuser.com/a/651015/299678
I.e. You can use a symbolic link, e.g.
mklink /D C:\myLink \\127.0.0.1\c$
You could us the 'net use' command:
var p = System.Diagnostics.Process.Start("net.exe", "use K: \\\\Server\\path");
var isCompleted = p.WaitForExit(5000);
If that does not work in a service, try the Winapi and PInvoke WNetAddConnection2
Edit: Obviously I misunderstood you - you can not change the sourcecode of the service, right? In that case I would follow the suggestion by mdb, but with a little twist: Create your own service (lets call it mapping service) that maps the drive and add this mapping service to the dependencies for the first (the actual working) service. That way the working service will not start before the mapping service has started (and mapped the drive).
ForcePush,
NOTE: The newly created mapped drive will now appear for ALL users of this system but they will see it displayed as "Disconnected Network Drive (Z:)". Do not let the name fool you. It may claim to be disconnected but it will work for everyone. That's how you can tell this hack is not supported by M$...
It all depends on the share permissions. If you have Everyone in the share permissions, this mapped drive will be accessible by other users. But if you have only some particular user whose credentials you used in your batch script and this batch script was added to the Startup scripts, only System account will have access to that share not even Administrator.
So if you use, for example, a scheduled ntbackuo job, System account must be used in 'Run as'.
If your service's 'Log on as: Local System account' it should work.
What I did, I didn't map any drive letter in my startup script, just used net use \\\server\share ... and used UNC path in my scheduled jobs. Added a logon script (or just add a batch file to the startup folder) with the mapping to the same share with some drive letter: net use Z: \\\... with the same credentials. Now the logged user can see and access that mapped drive. There are 2 connections to the same share. In this case the user doesn't see that annoying "Disconnected network drive ...". But if you really need access to that share by the drive letter not just UNC, map that share with the different drive letters, e.g. Y for System and Z for users.
Found a way to grant Windows Service access to Network Drive.
Take Windows Server 2012 with NFS Disk for example:
Step 1: Write a Batch File to Mount.
Write a batch file, ex: C:\mount_nfs.bat
echo %time% >> c:\mount_nfs_log.txt
net use Z: \\{your ip}\{netdisk folder}\ >> C:\mount_nfs_log.txt 2>&1
Step 2: Mount Disk as NT AUTHORITY/SYSTEM.
Open "Task Scheduler", create a new task:
Run as "SYSTEM", at "System Startup".
Create action: Run "C:\mount_nfs.bat".
After these two simple steps, my Windows ActiveMQ Service run under "Local System" priviledge, perform perfectly without login.
The reason why you are able to access the drive in when you normally run the executable from command prompt is that when u are executing it as normal exe you are running that application in the User account from which you have logged on . And that user has the privileges to access the network. But , when you install the executable as a service , by default if you see in the task manage it runs under 'SYSTEM' account . And you might be knowing that the 'SYSTEM' doesn't have rights to access network resources.
There can be two solutions to this problem.
To map the drive as persistent as already pointed above.
There is one more approach that can be followed. If you open the service manager by typing in the 'services.msc'you can go to your service and in the properties of your service there is a logOn tab where you can specify the account as any other account than 'System' you can either start service from your own logged on user account or through 'Network Service'. When you do this .. the service can access any network component and drive even if they are not persistent also.
To achieve this programmatically you can look into 'CreateService' function at
http://msdn.microsoft.com/en-us/library/ms682450(v=vs.85).aspx and can set the parameter 'lpServiceStartName ' to 'NT AUTHORITY\NetworkService'. This will start your service under 'Network Service' account and then you are done.
You can also try by making the service as interactive by specifying SERVICE_INTERACTIVE_PROCESS in the servicetype parameter flag of your CreateService() function but this will be limited only till XP as Vista and 7 donot support this feature.
Hope the solutions help you.. Let me know if this worked for you .
I find a very simple method: using command "New-SmbGlobalMapping" of powershell, which will mount drive globally:
$User = "usernmae"
$PWord = ConvertTo-SecureString -String "password" -AsPlainText -Force
$creds = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $User, $PWord
New-SmbGlobalMapping -RemotePath \\192.168.88.11\shares -Credential $creds -LocalPath S:
You wan't to either change the user that the Service runs under from "System" or find a sneaky way to run your mapping as System.
The funny thing is that this is possible by using the "at" command, simply schedule your drive mapping one minute into the future and it will be run under the System account making the drive visible to your service.
I can't comment yet (working on reputation) but created an account just to answer #Tech Jerk #spankmaster79 (nice name lol) and #NMC issues they reported in reply to the "I found a solution that is similar to the one with psexec but works without additional tools and survives a reboot." post #Larry had made.
The solution to this is to just browse to that folder from within the logged in account, ie:
\\servername\share
and let it prompt to login, and enter the same credentials you used for the UNC in psexec. After that it starts working. In my case, I think this is because the server with the service isn't a member of the same domain as the server I'm mapping to. I'm thinking if the UNC and the scheduled task both refer to the IP instead of hostname
\\123.456.789.012\share
it may avoid the problem altogether.
If I ever get enough rep points on here i'll add this as a reply instead.
Instead of relying on a persistent drive, you could set the script to map/unmap the drive each time you use it:
net use Q: \\share.domain.com\share
forfiles /p Q:\myfolder /s /m *.txt /d -0 /c "cmd /c del #path"
net use Q: /delete
This works for me.

SSH C# & Cisco devices configuration download

I'm trying to write some software in C# VS which is going to be used to connect through SSH to network devices ( Cisco Switches / Routers ) and download their configuration periodically. I've already tried SharpSSH, SSH.NET. The former is outdated and bugged, the latter just spams exceptions. What I did manage to do is use plink through the Process class to log into the device. Using redirected IO I even managed to print out the configuration. Unfortunately it doesn't print out in full. After a couple of lines a control line stops the output and waits for input
R1#show running-config
Building configuration...
Current configuration : 890 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$Or0j$2.HDFSXaC9jh/KGxhyl6I1
!
no aaa new-model
memory-size iomem 5
ip cef
!
!
!
!
no ip domain lookup
--More--
Like so. It seems like it's a console issue since I turned the feature to output without waiting on on the device. Sending anything at that moment i just like sending a command to the device so I can't actually ask for MORE output ( or at least I haven't found a way ). This may be either the console output issue ( asking whether to output more ) or the StreamWriter going full. My question is: is it possible to turn waiting OFF in a console application? If no - what would you suggest I do? Any ideas are welcome.
kravvcu
Of course you can turn off " --More--". This command will help you (on routers and switches):
R1#terminal length 0
and this one (on Cisco ASA)
terminal pager 0
Use a lightweight TFTP library and use that instead of console downloads?
http://www.codeproject.com/Articles/19314/A-simple-TFTP-client-using-C
If you are set on the console version, just process start a plink connection and read your config off of the process i/o.
http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

Access Remote MSMQ Count

My machine is in Domain D1 and there are public MSMQs in a remote server in domain D2. I am connected through vpn to D2, i.e I can RDP the machine in D2 and access the MSMQ.
What I want is to access (Know the message count) of the MSMQ without RDPing the system. So I build an application for this. I used Impersonation to impersonate the user of D2(i.e used credentials of D2)but the problem is I am not able to access the "Public" MSMQ ( used Messagequeue.GetPublicQueue() ) and exceptions are thrown with message "A workgroup installation computer does not support the operation." but when I used MessageQueue.GetPrivateQueue() it returned a collection of private queue.
I tried using MSMQManager for messageCount
Path = #"Direct:OS:machine\publicqueue";
FormatName=null;
new MSMQManager.inIt(machineName, path , FormatName);
This also throws an exception either the queue is not present or not open. but I can check that queue is working fine.
Are you comfortable doing a tiny bit of programming? If not, are you comfortable using PowerShell?
Either way - I would check out this post as it seems to contain the answers you are looking for.
Good luck, hope this helps
Your problem might be that you are working remotely.
The method GetPublicQueuesByMachine() is indeed not available over remote access.
You can see this in a feature matrix in the MSDN documentation: MessageQueue.GetPublicQueuesByMachine:
The following table shows whether this method is available in various Workgroup modes.
Workgroup mode Available
-------------- ---------
Local computer No
Local computer and direct format name No
Remote computer No
Remote computer and direct format name No
Also check the access privileges of your queues.
If I am wrong in the previous suggestion, it might be as simple as experimenting with the access rights for specific users in the network.
MSDN article Public and private queues states:
Default security access for public queues gives everyone permission to
send messages to a public queue. Specific permissions must be
granted for read access.
As for the actual message counting, John Opincar wrote a nice article about counting messages here: Counting Messages in an MSMQ MessageQueue from C#

Accessing the Ubuntu terminal from Mono

Background
I'm writing an web application so I can control an Ubuntu Server from a web site.
One idea I had was to run the 'screen' application from mono and redirect my input and output from there.
Running 'screen' from mono:
ProcessStartInfo info = new ProcessStartInfo("screen", "-m");
info.UseShellExecute = false;
info.RedirectStandardOutput = true;
info.RedirectStandardInput = true;
var p = new Process();
p.StartInfo = info;
p.Start();
var output = p.StandardOutput;
var input = p.StandardInput;
but running 'screen' with the RedirectStandardInput gives out the error:
Must be connected to a terminal
I've tried many different arguments and none seems to work with 'Redirecting Standard Input'
Other ideas for controlling a server will be greatly appreciated
I think this is the typical question in which you're asking how to implement your solution to a problem, instead of asking how to solve your problem. I don't think you should do hacky things like making a web app that tunnels the user actions to the server via a terminal.
I think you can bypass all that and, without writing a single line of code, take advantage of what the platform (Gtk+ in this case) already provides you:
You could run gnome-terminal in the server with the Broadway GDK backend. This way the gnome-terminal app will not run in the server, but open a web server on the port you specify. Later, you can use any WebSockets-enabled browser to control it.
This is the easiest and less hacky solution compared to the other ones offered so far. If you still are excited about using Mono for web development you still can, and you could embed this access in an iFrame or something.
(PS: If you don't want to depend on GTK being installed in the server; you could just use WebSockets in your client part of the webpage to be able to send events from the server to the client, and the library SSHNET to send the user's input directly through the wire.)
screen will need a terminal of some sort. It's also gigantically overkill.
You may wish to investigate the pty program from the Advanced Programming in the Unix Environment book (pty/ in the sources) to provide a pseudo-terminal that you can drive programmatically. (You'd probably run the pty program as-provided and write your driver in Mono if you're so inclined.) (The pty program will make far more sense if studied in conjunction with the book.)
The benefit to using the pty program, or functionality similar to it, is that you'd properly handle programs such as passwd that open("/dev/tty") to prompt the user for a password. If you simply redirect standard IO streams via pipe() and dup2() system calls, you won't have a controlling terminal for the programs that need one. (This is still a lot of useful programs but not enough to be a remote administration tool.)
There may be a Mono interface to the pty(7) system; if so, it may be more natural to use it than to use the C API, but the C API is what does the actual work, so it may be easier to just write directly in the native language.
A different approach to solve the same problem is shellinabox. Also interesting is this page from the anyterm website that compares different products that implement this kind of functionality.
Using shellinabox is very simple:
# ./shellinaboxd -s /:LOGIN
(this is the example given on their website) will start a webserver (on in your case the Ubuntu server). When you point your browser to http://yourserver:4200 you'll see a login screen, just like you would see when opening a session with ssh/putty/telnet/... but in your browser.
You could provide the required remote access functionality to the server's shell by just including an iframe that points to that service in your application's webpage.

Connecting to a network drive programmatically and caching credentials

I'm finally set up to be able to work from home via VPN (using Shrew as a client), and I only have one annoyance. We use some batch files to upload config files to a network drive. Works fine from work, and from my team lead's laptop, but both of those machines are on the domain. My home system is not, and won't be, so when I run the batch file, I get a ton of "invalid drive" errors because I'm not a domain user.
The solution I've found so far is to make a batch file with the following:
explorer \\MACHINE1
explorer \\MACHINE2
explorer \\MACHINE3
Then manually login to each machine using my domain credentials as they pop up. Unfortunately, there are around 10 machines I may need to use, and it's a pain to keep entering the password if I missed one that a batch file requires.
I'm looking into using the answer to this question to make a little C# app that'll take the login info once and login programmatically. Will the authentication be shared automatically with Explorer, or is there anything special I need to do? If it does work, how long are the credentials cached?
Is there an app that does something like this automatically?
Unfortunately, domain authentication via the VPN isn't an option, according to our admin.
EDIT: If there's a way to pass login info to Explorer via the command line, that would be even easier using Ruby and highline.
EDIT: In case anyone else has the same problem, here's the solution I wound up using. It requires Ruby and the Highline gem.
require "highline/import"
domain = ask("Domain: ")
username = ask("Username: ")
password = ask("Password: ") { |q| q.echo = false }
machines = [
'\\MACHINE1\SHARE',
'\\MACHINE2\SHARE',
'\\MACHINE3\SHARE',
'\\MACHINE4\SHARE',
'\\MACHINE5\SHARE'
]
drives = ('f'..'z').to_a[-machines.length..-1]
drives.each{|d| system("net use #{d}: /delete >nul 2>nul"); }
machines.zip(drives).each{|machine, drive| system("net use #{drive}: #{machine} #{password} /user:#{domain}\\#{username} >nul 2>nul")}
It'll figure out how many mapped drives I need, then start mapping them to the requested shares. In this case, it maps them from V: to Z:, and assumes I don't have anything shared with those drive letters.
If you already have an Explorer window open to one of the shares, it may give an error, so before I ran the Ruby script, I ran:
net use * /delete
That cleared up the "multiple connections to a share not permitted" error, and allowed me to connect with no problems.
You could create a batch file that uses "NET USE" to connect to your shares. You'd need to use a drive letter for each share, but it'd be super simple to implement.
Your batch file would look like this:
net use h: \\MACHINE1 <password> /user:<domain>\<user>
net use i: \\MACHINE2 <password> /user:<domain>\<user>
net use j: \\MACHINE3 <password> /user:<domain>\<user>
UPDATE
Whether the connection remains or not depends upon what you specified for the /persistent switch. If you specified yes, then it will attempt to reconnect upon your next logon. If you specified no then it won't. The worrying this is the documentation says that it defaults to the value that you used last!
If you specified no, the connection will remain until you next reboot. If you drop your VPN connection the drive would be unavailable (but if you reconnect to the VPN the drive should be available as long as you haven't removed it).
I don't know of a way to use it without mapping to a drive letter, the documentation would lead you to believe that it isn't possible.
I understand your problem, that you're just trying to give explorer the correct credentials so it stops nagging you with login boxes. Using mapped drives though not perfect will at least alleviate your pain.
to pass credential by command line to the explorer you should take a look into the command net use
Use API WNetAddConnection2() via P/Invoke.

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