I have the following problem. I use Embarcadero Rad Studio 10.1 Berlin Firemonkey. I want to connect to a POP3 server within an IPv6 network where IPv4 is not enabled and I get the socket error # 11004 error. My code is:
int port = 110;
pop3->Host = ...
pop3->Username = ...
pop3->Password = ..
pop3->AuthType = patUserPass;
pop3->IOHandler = iOHandlerStack;
iOHandlerStack->IPVersion = TIdIPVersion::Id_IPv6;
pop3->UseTLS = utNoTLSSupport;
pop3->Port = port;
iOHandlerStack->Port = port;
try
{
pop3->ConnectTimeout = 5000;
pop3->Connect();
int msgc = pop3->CheckMessages();
pop3->Disconnect();
ShowMessage("OK: " + IntToStr(msgc));
}
catch (Exception &exc)
{
ShowMessage(exc.Message);
}
If I use the application within an IPv4 network then after connecting the IPVersion property is set to Id_IPv4 automatically and there is no problem.
Interesting thing is that the following code works within IPv6 network:
IdTCPClient->IPVersion = TIdIPVersion::Id_IPv6;
IdTCPClient->Host = ...
IdTCPClient->Port = 80;
IdTCPClient->Connect();
IdTCPClient->Disconnect();
ShowMessage("OK");
Any suggestion?
You need to set the pop3->IPVersion property (which is inherited from TIdTCPClient) instead of the iOHandlerStack->IPVersion property directly.
Connect() overrides the IOHandler's IPVersion property value with the higher layer TIdTCPClient::IPVersion property value.
So, if you are leaving pop3->IPVersion to its default value of Id_IPv4, that would explain why you can't connect using IPv6. And why your TIdTCPClient example works.
Also, you don't need to set the iOHandlerStack->Port property manually, Connect() handles that as well.
Related
I am unable to use a Type Provider on a localhost for an Android Emulator.
This doesn't work for me when using F#'s Type Provider because the TypeProvider establishes a connection at design-time.
The Type Provider is happy when I use localhost
[<Literal>]
let JsonPath = "http://localhost:48213/api/cars"
type Repository = JsonProvider<JsonPath>
However, I receive a connection refused when attempting to use the localhost path. Details about this error can be found here.
As a result, I believe the resolution is to use an alternative IP address:
10.0.2.2
The Type Provider is NOT happy when I use 10.0.2.2
Replacing "localhost" with "10.0.2.2" on the IP address results in a compilation error stemming from the TypeProvider not establishing a connection to the updated IP address.
The following code will not compile when I attempt to use "10.0.2.2" as the alternative IP (AKA: workaround) which is the required IP for the emulator to work:
[<Literal>] (* "10.0.2.2" is the workaround IP for local host *)
let JsonPath = "http://10.0.2.2:48213/api/cars"
type Repository = JsonProvider<JsonPath>
type Car = { Make:string ; Model:string }
let getCars() =
Repository.Load JsonPath
|> Array.toSeq
|> Seq.map(fun x -> { Make=x.Make ; Model=x.Model })
In conclusion, how can I access a file via a WebAPI service run locally, and still keep the Type Provider happy when executing the Type Provider on an Emulator?
The static parameter you provide when you create the JsonProvider is purely for design time, in order for it to generate you the types. When you call Repositor.Load this will be the uri you use for runtime. They should be treated separately, like this:
[<Literal>]
let DevelopmentJsonPath = "http://localhost:48213/api/cars"
type Repository = JsonProvider<DevelopmentJsonPath>
type Car = { Make:string ; Model:string }
let runtimeUri = "http://production.mycompany.com/api/cars"
let getCars() =
Repository.Load runtimeUri
|> Array.toSeq
|> Seq.map(fun x -> { Make=x.Make ; Model=x.Model })
I am trying to create a Processing application connected with an Arduino.
Due to the fact that I want the connection between the two to be established automatically, meaning that I do not specify the name of the port, but I'm using Serial.list() to get the names of the ports available and then with a for loop I will check which one is printing the correct string.
The problem is that when I access firstly the /dev/cu.* then all the /dev/tty.* ports are busy and vice versa. This is quite strange and I do not want this to happen.
You should be able to use one(/dev/tty.*) or the other(/dev/cu.*), but not both at the same time as they might point to the same resource in different ways.
I recommend listing the ports, checking the port prefix (agains let's say /dev/tty.*, but not /dev/cu.*), initialising the Serial port, then exiting the loop that traverses the listed serial ports:
import processing.serial.*;
Serial arduino;
final int BAUD_RATE = 9600;
void setup(){
String[] ports = Serial.list();
for(int i = 0 ; i < ports.length; i++){//go through each port
if(ports[i].contains("tty.usbmodem")){//find one that looks like an Arduino on OSX
try{
arduino = new Serial(this,ports[i],BAUD_RATE);//initialize the connection
i = ports.length;//exit the loop, break; should also work
println("Arduino connection succesfully initialized");
}catch(Exception e){
System.err.println("Error opening Serial port!\nPlease check USB connection and ensure the port is not already open in another application.");
e.printStackTrace();
}
}
}
if(arduino == null) System.err.println("Serial connection to Arduino failed!");
}
I've installed Observium and it's working great, except for one thing: no ports are showing up.
I've added 3 devices with snmpd installed (Debian 7), all the graphs are displayed (cpu, mem) except for the network traffic ones, and on the front page, it shows:
Ports 0 0 up 0 down 0 ignored 0 disabled
I've also installed the agent on one device, it didn't change anything.
The config used is here (all the private informations are noted xx):
$config['db_host'] = 'localhost';
$config['db_user'] = 'xx';
$config['db_pass'] = 'xx';
$config['db_name'] = 'xx';
// Base directory
$config['install_dir'] = "/opt/observium";
// Default community list to use when adding/discovering
$config['snmp']['community'] = array("xx");
// Authentication Model
$config['auth_mechanism'] = "mysql"; // default, other options: ldap, http-auth, please see documentation for config he$
// Enable alerter (not available in CE)
#$config['poller-wrapper']['alerter'] = TRUE;
// Set up a default alerter (email to a single address)
$config['alerts']['alerter']['default']['descr'] = "Observium - Alert";
$config['alerts']['alerter']['default']['type'] = "email";
$config['alerts']['alerter']['default']['contact'] = "xx#xx.com";
$config['alerts']['alerter']['default']['enable'] = TRUE;
$config['poller_modules']['unix-agent'] = 1;
$config['collectd_dir'] = '/var/lib/collectd/rrd';
$config['int_customers'] = 1; # Enable Customer Port Parsing
$config['int_transit'] = 1; # Enable Transit Types
$config['int_peering'] = 1; # Enable Peering Types
$config['int_core'] = 1; # Enable Core Port Types
$config['int_l2tp'] = 0; # Enable L2TP Port Types
$config['show_locations'] = 1; # Enable Locations on menu
$config['show_locations_dropdown'] = 1; # Enable Locations dropdown on menu
$config['show_services'] = 0; # Enable Services on menu (Disabled by default as this option is deprecated)
$config['ports_page_default'] = "details/"; ## eg "details/" "graphs/bits/"
$config['show_overview_tab'] = true;
$config['overview_show_sysDescr'] = true;
$config['frontpage']['device_status']['ports'] = true;
$config['device_traffic_iftype'] = array('/loopback/','/tunnel/','/virtual/','/mpls/');
$config['device_traffic_descr'] = array('/loopback/','/vlan/','/tunnel/','/:\d+/');
// End config.php
Is the configuration the problem ? Is it only from Professional editions ?
Thank you for your help, I'm new to Observium and I really find it awesome (excepted this one little problem...)
Problem solved !
Easy fix on my MySQL Observium database:
ALTER TABLE `ports` CHANGE `port_label_short` `port_label_short` VARCHAR( 255 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ;
Explanation:
I've ran ./discovery.php -d -m ports -h 4 (4 being my host id), and it showed a lot of errors when running queries:
ERROR[Error in query: (1364) Field 'port_label_short' doesn't have a default value]
This error was the key, as I only needed to set a default value on this column.
We're having trouble connecting to a remote Firebird server using the .NET provider FbConnectionStringBuilder class. We can connect to a local database file in either embedded or server mode however when it comes to establishing a connection to a remote server we can't establish the connection.
We assign properties of the FbConnectionStringBuilder class with the following code (server mode). I have omitted the code which assigns properties for embedded mode.
var cs = new FbConnectionStringBuilder
{
Database = databaseSessionInfo.PathAbsoluteToDatabase,
Charset = "UTF8",
Dialect = 3,
};
cs.DataSource = databaseSessionInfo.Hostname;
cs.Port = databaseSessionInfo.Port;
cs.ServerType = (FbServerType)databaseSessionInfo.Mode;
cs.Pooling = true;
cs.ConnectionLifeTime = 30;
if (databaseSessionInfo.UseCustomUserAccount)
{
cs.UserID = databaseSessionInfo.Username;
cs.Password = databaseSessionInfo.Password;
}
else
{
cs.UserID = Constants.DB_DefaultUsername;
cs.Password = Constants.DB_DefaultPassword;
}
Pretty straightforward. Our software contains a connection configuration screen whereby a user can supply different connection properties. These properties get assigned to the FbConnectionStringBuilder class using the code above.
The connection builder class outputs a connection string in the following format:
initial catalog="P:\Source\database.fdb";character set=UTF8;dialect=3;data source=localhost;port number=3050;server type=Default;pooling=True;connection lifetime=30;user id=USER;password=example
However literature on Firebird connection strings as indicated on this page (Firebird Connection Strings) talk of a different structure. I can only assume the FbConnectionStringBuilder class builds a Firebird connection string satisfying the requirements of Firebird.
Does the FbConnectionStringBuilder class append the hostname to the connection string correctly?
The Firebird server is running on the server. I assume there is no need to install it on the client?
What libraries need to be installed with the client to support a remote server connection?
Are we doing this right?
Any advice is appreciated.
Answering your questions:
1) Yes it will.
2) Correct, the client library will connect over the network.
3) If you use the ADO library, just FirebirdSql.Data.FirebirdClient.dll
4) Maybe, I dont know if this will help but this is how I connect.
FbConnectionStringBuilder ret = new FbConnectionStringBuilder();
ret.DataSource = Host;
ret.Port = Port;
ret.Database = Database;
ret.UserID = User;
ret.Password = Password;
ret.Charset = CharacterSet;
FbConnection ret = new FbConnection(connectionString);
Interestingly, what is the absolute path you are providing to the StringBuilder ? Is it the server absolute path, or some kind of network mapped drive?
Also, I assume you've reviewed firewall settings and allowing port 3050 inbound.
I'm using Xamarin.mac. I need to get the fully qualified domain name of the local computer. On Windows this code works:
public string GetFQDN()
{
string domainName = System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().DomainName;
string hostName = Dns.GetHostName();
string fqdn = "";
if (!hostName.Contains(domainName))
fqdn = hostName + "." + domainName;
else
fqdn = hostName;
return fqdn;
}
On a mac this code causes this error: System.NotSupportedException: This platform is not supported.
So, what is the equivalent in Xamarin.mac? Or just in Mono?
Just getting the computer name would be a good start.
To do this, you can pretty much do the same you'd do in C on a UNIX system, which is to retrieve the hostname with gethostname() and then use a DNS lookup to find the canonical network name for the host. Luckily, System.Net has ready-made calls for this. The following code should work on both OS X and Linux (in fact, on Linux it is more or less what hostname --fqdn does):
using System;
using System.Net;
class Program {
static void Main() {
// Step 1: Get the host name
var hostname = Dns.GetHostName();
// Step 2: Perform a DNS lookup.
// Note that the lookup is not guaranteed to succeed, especially
// if the system is misconfigured. On the other hand, if that
// happens, you probably can't connect to the host by name, anyway.
var hostinfo = Dns.GetHostEntry(hostname);
// Step 3: Retrieve the canonical name.
var fqdn = hostinfo.HostName;
Console.WriteLine("FQDN: {0}", fqdn);
}
}
Note that with a misconfigured DNS, the DNS lookup may fail, or you may get the rather useless "localhost.localdomain".
If you wish to emulate your original approach, you can use the following code to retrieve the domainname:
var domainname = new StringBuilder(256);
Mono.Unix.Native.Syscall.getdomainname(domainname,
(ulong) domainname.Capacity - 1);
You will need to add the Mono.Posix assembly to your build for this.