Objective-C

Get an SSH Tunnel's Current State (Diagnostics)

Demonstrates the Chilkat SshTunnel.GetCurrentState method, which returns an XML snapshot describing the tunnel manager, SSH channels, and current tunnel clients. It takes no arguments and is intended for diagnostics and monitoring.

Background: Because the tunnel forwards traffic on a background thread, there is no natural place in your code to observe what it is doing at a given moment. GetCurrentState provides that visibility — byte counts, active channels, and connected clients — as structured XML suited to logging or a monitoring dashboard. It is a read-only snapshot and does not affect the tunnel.

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Objective-C

#import <CkoSshTunnel.h>
#import <NSString.h>

BOOL success = NO;

//  Demonstrates the SshTunnel.GetCurrentState method, which returns an XML snapshot describing the
//  tunnel manager, SSH channels, and current tunnel clients.  It takes no arguments and is
//  intended for diagnostics and monitoring.

CkoSshTunnel *tunnel = [[CkoSshTunnel alloc] init];

//  The tunnel forwards accepted local connections to this destination through the SSH server.
tunnel.DestHostname = @"db.internal.example.com";
tunnel.DestPort = [NSNumber numberWithInt:5432];

//  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
//  does not authenticate yet.
int sshPort = 22;
success = [tunnel Connect: @"ssh.example.com" port: [NSNumber numberWithInt: sshPort]];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
NSString *password = @"mySshPassword";

success = [tunnel AuthenticatePw: @"mySshLogin" password: password];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

//  Begin accepting so there is live tunnel state to inspect.
int listenPort = 1080;
success = [tunnel BeginAccepting: [NSNumber numberWithInt: listenPort]];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

//  Get a diagnostic snapshot of the tunnel's current state as XML.
NSString *stateXml = [tunnel GetCurrentState];
if (tunnel.LastMethodSuccess == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}

NSLog(@"%@",stateXml);

BOOL waitForThreadExit = YES;
success = [tunnel CloseTunnel: waitForThreadExit];
if (success == NO) {
    NSLog(@"%@",tunnel.LastErrorText);
    return;
}