Tunnel.m

//
//  Tunnel.m
//  MongoHub
//
//  Created by Syd on 10-12-15.
//  Copyright 2010 ThePeppersStudio.COM. All rights reserved.
//

#import "Tunnel.h"
#import <Security/Security.h>
#import "NSString+Extras.h"

#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/sysctl.h>

typedef struct kinfo_proc kinfo_proc;

static int GetBSDProcessList(kinfo_proc **procList, size_t *procCount)
// Returns a list of all BSD processes on the system.  This routine
// allocates the list and puts it in *procList and a count of the
// number of entries in *procCount.  You are responsible for freeing
// this list (use "free" from System framework).
// On success, the function returns 0.
// On error, the function returns a BSD errno value.
{
    int                 err;
    kinfo_proc *        result;
    bool                done;
    static const int    name[] = { CTL_KERN, KERN_PROC, KERN_PROC_ALL, 0 };
    // Declaring name as const requires us to cast it when passing it to
    // sysctl because the prototype doesn't include the const modifier.
    size_t              length;
	
    assert( procList != NULL);
    assert(*procList == NULL);
    assert(procCount != NULL);
	
    *procCount = 0;
	
    // We start by calling sysctl with result == NULL and length == 0.
    // That will succeed, and set length to the appropriate length.
    // We then allocate a buffer of that size and call sysctl again
    // with that buffer.  If that succeeds, we're done.  If that fails
    // with ENOMEM, we have to throw away our buffer and loop.  Note
    // that the loop causes use to call sysctl with NULL again; this
    // is necessary because the ENOMEM failure case sets length to
    // the amount of data returned, not the amount of data that
    // could have been returned.
	
    result = NULL;
    done = false;
    do {
        assert(result == NULL);
		
        // Call sysctl with a NULL buffer.
		
        length = 0;
        err = sysctl( (int *) name, (sizeof(name) / sizeof(*name)) - 1,
					 NULL, &length,
					 NULL, 0);
        if (err == -1) {
            err = errno;
        }
		
        // Allocate an appropriately sized buffer based on the results
        // from the previous call.
		
        if (err == 0) {
            result = malloc(length);
            if (result == NULL) {
                err = ENOMEM;
            }
        }
		
        // Call sysctl again with the new buffer.  If we get an ENOMEM
        // error, toss away our buffer and start again.
		
        if (err == 0) {
            err = sysctl( (int *) name, (sizeof(name) / sizeof(*name)) - 1,
						 result, &length,
						 NULL, 0);
            if (err == -1) {
                err = errno;
            }
            if (err == 0) {
                done = true;
            } else if (err == ENOMEM) {
                assert(result != NULL);
                free(result);
                result = NULL;
                err = 0;
            }
        }
    } while (err == 0 && ! done);
	
    // Clean up and establish post conditions.
	
    if (err != 0 && result != NULL) {
        free(result);
        result = NULL;
    }
    *procList = result;
    if (err == 0) {
        *procCount = length / sizeof(kinfo_proc);
    }
	
    assert( (err == 0) == (*procList != NULL) );
	
    return err;
}


static int GetFirstChildPID(int pid)
/*" Returns the parent process id 
 for the given process id (pid). "*/
{
	int pidFound = -1;
	
	kinfo_proc* plist = nil;
	size_t len = 0;
	GetBSDProcessList(&plist,&len);
	
	if(plist != nil){	
		for(int i = 0;i<len;i++){
			if(plist[i].kp_eproc.e_ppid == pid){
				pidFound = plist[i].kp_proc.p_pid;
				break;
			}
		}
		
		free(plist);
	}
	
	return pidFound;
}

@implementation Tunnel

- (id) init {
	if(self = [super init]){
        uid = [NSString UUIDString];
        
        lock = [NSLock new];
        portForwardings = [NSMutableArray array];
        isRunning = NO;
	}
	
	return (self);
}

@synthesize uid;
@synthesize name;
@synthesize host;
@synthesize port;
@synthesize user;
@synthesize password;
@synthesize aliveInterval;
@synthesize aliveCountMax;
@synthesize tcpKeepAlive;
@synthesize compression;
@synthesize additionalArgs;
@synthesize portForwardings;

- (void)setDelegate:(id)val {
    delegate = val;
}

- (id)delegate {
    return delegate;
}


-(void) start {
	[lock lock];
	
	isRunning = YES;
	
	task = [NSTask new];
	pipe = [NSPipe pipe];
	
	[task setLaunchPath: [[NSBundle bundleForClass:[self class]] pathForResource: @"SSHCommand" ofType: @"sh"] ];
	[task setArguments: [self prepareSSHCommandArgs] ];
	[task setStandardOutput: pipe];
	//The magic line that keeps your log where it belongs
	[task setStandardInput:[NSPipe pipe]];
	
	[task launch];
    /*NSData *output = [[pipe fileHandleForReading] readDataToEndOfFile];
    NSString *string = [[[NSString alloc] initWithData: output encoding: NSUTF8StringEncoding] autorelease];
    
    NSLog(@"\n%@\n", string);*/
	pipeData = @"";
	retStatus = @"";
	startDate = [NSDate date];
	NSLog(@"%@", startDate);
	if ( [delegate respondsToSelector:@selector(tunnelStatusChanged:status:)] ) {
		[delegate tunnelStatusChanged: self status: @"START"];
	}
	
	[lock unlock];
}

-(void) stop {
	[lock lock];
	
	isRunning = NO;
    
	if ( [task isRunning] ){
		int chpid = GetFirstChildPID([task processIdentifier]);
		if(chpid != -1)
			kill(chpid,  SIGTERM);
		[task terminate];
		task = nil;
	}
	if ( [delegate respondsToSelector:@selector(tunnelStatusChanged:status:)] ) {
		[delegate tunnelStatusChanged: self status: @"STOP"];
	}
	
	[lock unlock];
}

-(BOOL) running {
	BOOL ret = NO;
	
	[lock lock];
	ret = isRunning;
	[lock unlock];
	
	return ret;
}

-(void) readStatus {
	[lock lock];
	if(isRunning && [retStatus isEqualToString: @""]){
		NSString *pipeStr = [[NSString alloc] initWithData: [[pipe fileHandleForReading] availableData] encoding: NSASCIIStringEncoding];
		pipeData = [pipeData stringByAppendingString:  pipeStr];
        [pipeStr release];
		NSRange r = [pipeData rangeOfString: @"CONNECTED"];
		if( r.location != NSNotFound ){
			retStatus = @"CONNECTED";
			
			if ( [delegate respondsToSelector:@selector(tunnelStatusChanged: status:)] ) {
				[delegate tunnelStatusChanged: self status: retStatus];
			}
			[lock unlock];
			return;
		}
		
		r = [pipeData rangeOfString: @"CONNECTION_ERROR"];
		if( r.location != NSNotFound ){
			retStatus = @"CONNECTION_ERROR";
			
			if ( [delegate respondsToSelector:@selector(tunnelStatusChanged: status:)] ) {
				[delegate tunnelStatusChanged: self status: retStatus];
			}
			[lock unlock];
			return;
		}
		
		r = [pipeData rangeOfString: @"CONNECTION_REFUSED"];
		if( r.location != NSNotFound ){
			retStatus = @"CONNECTION_REFUSED";
			
			if ( [delegate respondsToSelector:@selector(tunnelStatusChanged: status:)] ) {
				[delegate tunnelStatusChanged: self status: retStatus];
			}
			[lock unlock];
			return;
		}
		
		r = [pipeData rangeOfString: @"WRONG_PASSWORD"];
		if( r.location != NSNotFound ){
			retStatus = @"WRONG_PASSWORD";
			
			if ( [delegate respondsToSelector:@selector(tunnelStatusChanged: status:)] ) {
				[delegate tunnelStatusChanged: self status: retStatus];
			}
			[lock unlock];
			return;
		}
		//NSLog(@"%@", startDate);
		/*if( [[NSDate date] timeIntervalSinceDate: startDate] > 30 ){
			retStatus = @"TIME_OUT";
			
			if ( [delegate respondsToSelector:@selector(tunnelStatusChanged: status:)] ) {
				[delegate tunnelStatusChanged: self status: retStatus];
			}
			
			return;
		}*/
	}
	[lock unlock];
}

-(BOOL) checkProcess {
	BOOL ret = NO;
	[lock lock];
	ret = isRunning;
	if( ret )
		ret = GetFirstChildPID( [task processIdentifier] ) != -1;	
	[lock unlock];
	
	return ret;
}

-(NSArray*) prepareSSHCommandArgs {
	
	NSString* pfs = @"";
	for(NSString* pf in portForwardings){
		NSArray* pfa = [pf componentsSeparatedByString: @":"];
		pfs = [NSString stringWithFormat: @"%@ -%@ %@:%@:%@:%@", pfs, [pfa objectAtIndex: 0], [pfa objectAtIndex: 2], [pfa objectAtIndex: 1], [pfa objectAtIndex: 3], [pfa objectAtIndex: 4] ];
	}
	
	NSString* cmd = [NSString stringWithFormat: @"ssh -N -o ConnectTimeout=28 %@%@%@%@%@%@-p %d %@@%@",
					 [additionalArgs length] > 0 ? [NSString stringWithFormat: @"%@ ", additionalArgs] : @"",
					 [pfs length] > 0 ? [NSString stringWithFormat: @"%@ ",pfs] : @"",
					 aliveInterval > 0 ? [NSString stringWithFormat: @"-o ServerAliveInterval=%d ",aliveInterval] : @"",
					 aliveCountMax > 0 ? [NSString stringWithFormat: @"-o ServerAliveCountMax=%d ",aliveCountMax] : @"",
					 tcpKeepAlive == YES ? @"-o TCPKeepAlive=yes " : @"",
					 compression == YES ? @"-C " : @"",
					 port,user,host];
	NSLog(@"cmd: %@", cmd);
	return [NSArray arrayWithObjects: cmd, password, nil];
}

-(void) tunnelLoaded {
	
	if(uid == nil || [uid length] == 0){
		CFUUIDRef uidref = CFUUIDCreate(nil);
		uid = (NSString*)CFUUIDCreateString(nil, uidref);
		CFRelease(uidref);
	}
	
	if([self keychainItemExists]){
		password = [self keychainGetPassword];
	}else{
		password = @"";
	}
}

-(void) tunnelSaved{
	if([self keychainItemExists]){
		[self keychainModifyItem];
	}else{
		[self keychainAddItem];
	}
}

-(void) tunnelRemoved {
	if([self keychainItemExists])
		[self keychainDeleteItem];
}

-(BOOL) keychainItemExists {
	
	SecKeychainSearchRef search;
	SecKeychainAttributeList list;
	SecKeychainAttribute attributes[3];
	
	NSString* keychainItemName = [NSString stringWithFormat: @"SSHTunnel <%@>", uid];
	NSString* keychainItemKind = @"application password";
	
	attributes[0].tag = kSecAccountItemAttr;
    attributes[0].data = (void *)[uid UTF8String];
    attributes[0].length = [uid length];
    
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[1].data = (void *)[keychainItemKind UTF8String];
    attributes[1].length = [keychainItemKind length];
	
	attributes[2].tag = kSecLabelItemAttr;
    attributes[2].data = (void *)[keychainItemName UTF8String];
    attributes[2].length = [keychainItemName length];	
	
	list.count = 3;
	list.attr = attributes;
	
	OSErr result = SecKeychainSearchCreateFromAttributes(NULL, kSecGenericPasswordItemClass, &list, &search);
	
    if (result != noErr) {
        NSLog (@"Error status %d from SecKeychainSearchCreateFromAttributes\n", result);
		return FALSE;
    }
	
	uint itemsFound = 0;
	SecKeychainItemRef item;
	
	while (SecKeychainSearchCopyNext (search, &item) == noErr) {
        CFRelease (item);
        itemsFound++;
    }
	
	CFRelease (search);
	return itemsFound > 0;	
}

-(BOOL) keychainAddItem {
	
	SecKeychainItemRef item;
	SecKeychainAttributeList list;
	SecKeychainAttribute attributes[3];
	
	NSString* keychainItemName = [NSString stringWithFormat: @"SSHTunnel <%@>", uid];
	NSString* keychainItemKind = @"application password";
	
	attributes[0].tag = kSecAccountItemAttr;
    attributes[0].data = (void *)[uid UTF8String];
    attributes[0].length = [uid length];
    
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[1].data = (void *)[keychainItemKind UTF8String];
    attributes[1].length = [keychainItemKind length];
	
	attributes[2].tag = kSecLabelItemAttr;
    attributes[2].data = (void *)[keychainItemName UTF8String];
    attributes[2].length = [keychainItemName length];	
	
	list.count = 3;
	list.attr = attributes;
	
	OSStatus status = SecKeychainItemCreateFromContent(kSecGenericPasswordItemClass, &list, [password length], [password UTF8String], NULL,NULL,&item);
    if (status != 0) {
        NSLog(@"Error creating new item: %d for %@\n", (int)status, keychainItemName);
    }
	
	return !status;	
}

-(BOOL) keychainModifyItem {
	
	SecKeychainItemRef item;
	SecKeychainSearchRef search;
    OSStatus status;
	OSErr result;
	SecKeychainAttributeList list;
	SecKeychainAttribute attributes[3];
	
	NSString* keychainItemName = [NSString stringWithFormat: @"SSHTunnel <%@>", uid];
	NSString* keychainItemKind = @"application password";
	
	attributes[0].tag = kSecAccountItemAttr;
    attributes[0].data = (void *)[uid UTF8String];
    attributes[0].length = [uid length];
    
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[1].data = (void *)[keychainItemKind UTF8String];
    attributes[1].length = [keychainItemKind length];
	
	attributes[2].tag = kSecLabelItemAttr;
    attributes[2].data = (void *)[keychainItemName UTF8String];
    attributes[2].length = [keychainItemName length];
	
	list.count = 3;
	list.attr = attributes;
	
	result = SecKeychainSearchCreateFromAttributes(NULL, kSecGenericPasswordItemClass, &list, &search);
    NSLog(@"%@", result);
	SecKeychainSearchCopyNext (search, &item);
    status = SecKeychainItemModifyContent(item, &list, [password length], [password UTF8String]);
	
    if (status != 0) {
        NSLog(@"Error modifying item: %d", (int)status);
    }
	
	CFRelease (item);
	CFRelease(search);
	
	return !status;	
}

-(BOOL) keychainDeleteItem {
	
	SecKeychainItemRef item;
	SecKeychainSearchRef search;
    OSStatus status = 0;
	OSErr result;
	SecKeychainAttributeList list;
	SecKeychainAttribute attributes[3];
	uint itemsFound = 0;
	
	NSString* keychainItemName = [NSString stringWithFormat: @"SSHTunnel <%@>", uid];
	NSString* keychainItemKind = @"application password";
	
	attributes[0].tag = kSecAccountItemAttr;
    attributes[0].data = (void *)[uid UTF8String];
    attributes[0].length = [uid length];
    
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[1].data = (void *)[keychainItemKind UTF8String];
    attributes[1].length = [keychainItemKind length];
	
	attributes[2].tag = kSecLabelItemAttr;
    attributes[2].data = (void *)[keychainItemName UTF8String];
    attributes[2].length = [keychainItemName length];	
	
	list.count = 3;
	list.attr = attributes;
	
	result = SecKeychainSearchCreateFromAttributes(NULL, kSecGenericPasswordItemClass, &list, &search);
    NSLog(@"%@", result);
	while (SecKeychainSearchCopyNext (search, &item) == noErr) {
        itemsFound++;
    }
	if (itemsFound) {
		status = SecKeychainItemDelete(item);
	}
	
    if (status != 0) {
        NSLog(@"Error deleting item: %d\n", (int)status);
    }
	CFRelease (item);
	CFRelease (search);
	
	return !status;	
}

-(NSString*) keychainGetPassword {
	
	SecKeychainItemRef item;
	SecKeychainSearchRef search;
    OSErr result;
	SecKeychainAttributeList list;
	SecKeychainAttribute attributes[3];
	
	NSString* keychainItemName = [NSString stringWithFormat: @"SSHTunnel <%@>", uid];
	NSString* keychainItemKind = @"application password";
	
	attributes[0].tag = kSecAccountItemAttr;
    attributes[0].data = (void *)[uid UTF8String];
    attributes[0].length = [uid length];
    
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[1].data = (void *)[keychainItemKind UTF8String];
    attributes[1].length = [keychainItemKind length];
	
	attributes[2].tag = kSecLabelItemAttr;
    attributes[2].data = (void *)[keychainItemName UTF8String];
    attributes[2].length = [keychainItemName length];
	
	
	list.count = 3;
	list.attr = attributes;
	
	result = SecKeychainSearchCreateFromAttributes(NULL, kSecGenericPasswordItemClass, &list, &search);
	
    if (result != noErr) {
        NSLog (@"status %d from SecKeychainSearchCreateFromAttributes\n", result);
    }
	
	NSString *pass = @"";
    if (SecKeychainSearchCopyNext (search, &item) == noErr) {
		pass = [self keychainGetPasswordFromItemRef:item];
		if(!pass) {
			pass = @"";
		}
		CFRelease (item);
		CFRelease (search);
	}
	
	return pass;	
}

-(NSString*) keychainGetPasswordFromItemRef: (SecKeychainItemRef)item {
	
	NSString* retPass = nil;
	
	UInt32 length;
    char *pass;
    SecKeychainAttribute attributes[8];
    SecKeychainAttributeList list;
    OSStatus status;
	
    attributes[0].tag = kSecAccountItemAttr;
    attributes[1].tag = kSecDescriptionItemAttr;
    attributes[2].tag = kSecLabelItemAttr;
    attributes[3].tag = kSecModDateItemAttr;
	
    list.count = 4;
    list.attr = attributes;
	
    status = SecKeychainItemCopyContent (item, NULL, &list, &length, (void **)&pass);
	
	if (status == noErr) {
        if (pass != NULL) {
			
            // copy the password into a buffer so we can attach a
            // trailing zero byte in order to be able to print
            // it out with printf
            char passwordBuffer[1024];
			
            if (length > 1023) {
                length = 1023; // save room for trailing \0
            }
            strncpy (passwordBuffer, pass, length);
			
            passwordBuffer[length] = '\0';
			
			retPass = [NSString stringWithUTF8String:passwordBuffer];
        }
		
        SecKeychainItemFreeContent (&list, pass);
		
		return retPass;		
    } else {
        printf("Error getting password = %d\n", (int)status);
		return @"";
    }	
}

- (void)encodeWithCoder:(NSCoder *)coder {
	
	[coder encodeObject: uid forKey: @"uid"];
	[coder encodeObject: name forKey: @"name"];
	[coder encodeObject: host forKey: @"host"];
	[coder encodeInt: port forKey: @"port"];
	[coder encodeObject: user forKey: @"user"];
	[coder encodeInt: aliveInterval forKey: @"aliveInterval"];
	[coder encodeInt: aliveCountMax forKey: @"aliveCountMax"];
	[coder encodeBool: tcpKeepAlive forKey: @"tcpKeepAlive"];
	[coder encodeBool: compression forKey: @"compression"];
	[coder encodeObject: additionalArgs forKey: @"additionalArgs"];
	[coder encodeObject: portForwardings forKey: @"portForwardings"];
	
	[self tunnelSaved];
}

- (id)initWithCoder:(NSCoder *)coder {
	
	uid = [coder decodeObjectForKey: @"uid"];
	name = [coder decodeObjectForKey: @"name"];
	host = [coder decodeObjectForKey: @"host"];
	port = [coder decodeIntForKey: @"port"];
	user = [coder decodeObjectForKey: @"user"];
	aliveInterval = [coder decodeIntForKey: @"aliveInterval"];
	aliveCountMax = [coder decodeIntForKey: @"aliveCountMax"];
	tcpKeepAlive = [coder decodeBoolForKey: @"tcpKeepAlive"];
	compression = [coder decodeBoolForKey: @"compression"];
	additionalArgs = [coder decodeObjectForKey: @"additionalArgs"];
	portForwardings = [coder decodeObjectForKey: @"portForwardings"];
	
	[self tunnelLoaded];
	
	return (self);
}

@end