Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle
wrote:
I'm trying to find my own ip address using std.socket with
little success. How would i go about doing this? (It should be
a AddressFamily.INET socket)
On Windows, you can use the Win32`GetAdaptersInfo`[1] function to
get a list of IPv4 adapters and addresses. If you need IPv6
addresses or other more modern features, there is the
`GetAdaptersAddresses`[2] function, however it doesn't seem the
necessary Windows headers (IPTypes.h / ifdef.h) have been ported
to D for this yet.
[1]
https://learn.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-getadaptersinfo
[2]
https://learn.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-getadaptersaddresses
As I attempt to post this, I now see this thread is... 10 years
old. Oh well, still relevant I think.
```d
import std.string;
pragma(lib, `mingw/iphlpapi.lib`); // included with dmd
struct Adapter {
string name;
string desc;
struct IPMask {
string ip;
string mask;
}
IPMask[] addresses;
}
Adapter[] getAdapters() {
import core.sys.windows.windows;
//import core.sys.windows.nspapi;
import core.sys.windows.iptypes;
import core.sys.windows.iphlpapi;
void[] buf;
uint size = 0;
auto ret = GetAdaptersInfo(null, );
assert(ret == ERROR_BUFFER_OVERFLOW && size > 0, "Expected
GetAdaptersInfo to return ERROR_BUFFER_OVERFLOW to query size of
buffer");
buf.length = size;
ret = GetAdaptersInfo(cast(IP_ADAPTER_INFO*) buf.ptr, );
assert(!ret, "GetAdaptersInfo error");
auto adpt = cast(IP_ADAPTER_INFO*) buf.ptr;
Adapter[] adapters;
while (adpt) {
scope(success) adpt = adpt.Next;
Adapter adapter;
adapter.name = adpt.AdapterName.fromStringz.idup;
adapter.desc = adpt.Description.fromStringz.idup;
IP_ADDR_STRING addr = adpt.IpAddressList;
auto paddr =
while (paddr) {
scope(success) paddr = addr.Next;
adapter.addresses ~=
Adapter.IPMask(paddr.IpAddress.String.fromStringz.idup,
paddr.IpMask.String.fromStringz.idup);
}
adapters ~= adapter;
}
return adapters;
}
void main() {
import std.stdio;
auto adapters = getAdapters();
adapters.writeln;
}
```
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle wrote: I'm trying to find my own ip address using std.socket with little success. How would i go about doing this? (It should be a AddressFamily.INET socket) Sadly, the standard library doesn't seem to offer network interface enumeration. However, if you don't mind delving into platform-specific C APIs that are exposed by Phobos but not mentioned in the docs ([issue 5872](https://issues.dlang.org/show_bug.cgi?id=5872)), it can be done. The code I found here was enough to get me started: https://github.com/Kripth/my-ip/blob/356e02f0/src/myip/private_.d The key to a linux implementation was `getifaddrs()`, which can be found in core.sys.linux.ifaddrs.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 22:31:53 UTC, Dicebot wrote:
On Tuesday, 4 February 2014 at 20:19:14 UTC, TheFlyingFiddle
wrote:
I'm setting up a simple local network enabling me to connect
phones to the computer through the local wi-fi. The simplest
way i could think of to make this work without relying on an
external server was to simply broadcast the ip and port to all
machines in the network.(Btw by server i mean my / my project
groups windows boxes).
So well the problem is that i need a way for the phones to
find running servers on the LAN.
I think it is close to impossible to do in portable way. Most
reliable approach is to get list of all configured network
interfaces via posix functions (or via `system` call as least
resort), filter out "lo" and broadcast message for every such
interface. I think you can also filter only wireless interfaces
that way relatively easily too.
Apologies that I am bumping a post that is 9 years old, but I
recently had to do this and thought this may help beginners. In a
way it's a hack as suggested from the second post, that you can
connect to a known ip address (e.g. google) from a socket and
then see the endpoints with the local and remote addresses.
```
import std.stdio;
import std.socket;
void GetIP(){
// A bit of a hack, but we'll create a connection from
google to
// our current ip.
// Use a well known port (i.e. google) to do this
auto r = getAddress("8.8.8.8",53); // NOTE: This is
effetively getAddressInfo
writeln(r);
// Create a socket
auto sockfd = new Socket(AddressFamily.INET,
SocketType.STREAM);
// Connect to the google server
import std.conv;
const char[] address = r[0].toAddrString().dup;
ushort port = to!ushort(r[0].toPortString());
sockfd.connect(new InternetAddress(address,port));
// Obtain local sockets name and address
writeln(sockfd.hostName);
writeln("Our ip address: ",sockfd.localAddress);
writeln("the remote address: ",sockfd.remoteAddress);
// Close our socket
sockfd.close();
}
```
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle wrote: I'm trying to find my own ip address using std.socket with little success. How would i go about doing this? (It should be a AddressFamily.INET socket) You can have lot of different local IP addresses on a single machine so question can't be answered properly. However you may use in `Socket.hostName` and resolve it via DNS to find IP machine itself currently consuders as its main pulbic IP.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle wrote: I'm trying to find my own ip address using std.socket with little success. How would i go about doing this? (It should be a AddressFamily.INET socket) Create a connection to another LAN machine with a known address (e.g. gateway or router), then use Socket's localAddress property to get your IP. You cannot really do that before establishing a connection, as Dicebot already mentioned.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:21:54 UTC, Stanislav Blinov wrote: Create a connection to another LAN machine with a known address (e.g. gateway or router), then use Socket's localAddress property to get your IP. Worth noting that this solution is not reliable in general either because your server can possibly have complicated routing configurations that will make, for example, LAN destination packets go via different network interface than WAN destination ones. It is probably better to tell what high-level problem you are trying to solve to find most useful compromise.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:13:07 UTC, Dicebot wrote: On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle wrote: I'm trying to find my own ip address using std.socket with little success. How would i go about doing this? (It should be a AddressFamily.INET socket) You can have lot of different local IP addresses on a single machine so question can't be answered properly. However you may use in `Socket.hostName` and resolve it via DNS to find IP machine itself currently consuders as its main pulbic IP. This works great thanks. I just need any (working) local IP address so getting more then one is not an issue for me.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:21:54 UTC, Stanislav Blinov wrote: On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle wrote: I'm trying to find my own ip address using std.socket with little success. How would i go about doing this? (It should be a AddressFamily.INET socket) Create a connection to another LAN machine with a known address (e.g. gateway or router), then use Socket's localAddress property to get your IP. You cannot really do that before establishing a connection, as Dicebot already mentioned. Problem is that i don't know in what local network the server will be running, so this is unfortunatly not an option for me.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:31:27 UTC, TheFlyingFiddle wrote: Problem is that i don't know in what local network the server will be running, so this is unfortunatly not an option for me. But if that's the case, the hostname solution may as well just give you your loopback address. :)
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 15:48:50 UTC, Vladimir Panteleev
wrote:
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle
wrote:
I'm trying to find my own ip address using std.socket with
little success. How would i go about doing this? (It should be
a AddressFamily.INET socket)
This program will print all of your computer's IP addresses:
import std.socket;
import std.stdio;
void main()
{
foreach (addr; getAddress(Socket.hostName))
writeln(addr.toAddrString());
}
This includes IPv6 addresses. You can filter the address family
by checking addr's addressFamily property.
I am a bit lost in anything networking related, so I ran this on
my machine just for fun and it printed:
127.0.0.1
127.0.0.1
127.0.0.1
which based on my understanding is the local loopback address (I
am not completely, 100% ignorant).
However if I run /sbin/ifconfig I get:
enp7s0Link encap:Ethernet HWaddr 50:E5:49:9B:29:49
inet addr:10.1.101.52 Bcast:10.1.101.255
Mask:255.255.255.0
inet6 addr: fe80::52e5:49ff:fe9b:2949/64 Scope:Link
loLink encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
This computer is on a network with dynamically assigned IP
address (DHCP).
So shouldn't the 10.1.101.52 address have been reported?
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 16:02:33 UTC, Craig Dillabaugh wrote: However if I run /sbin/ifconfig I get: enp7s0Link encap:Ethernet HWaddr 50:E5:49:9B:29:49 inet addr:10.1.101.52 Bcast:10.1.101.255 Mask:255.255.255.0 inet6 addr: fe80::52e5:49ff:fe9b:2949/64 Scope:Link loLink encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host This computer is on a network with dynamically assigned IP address (DHCP). So shouldn't the 10.1.101.52 address have been reported? It results in all addresses you hostname resolvs to. On all desktop linux machines /etc/hosts is configured to resolve hostname to localhost by default. On servers it usually resolves to externally accessible one.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:02:26 UTC, TheFlyingFiddle
wrote:
I'm trying to find my own ip address using std.socket with
little success. How would i go about doing this? (It should be
a AddressFamily.INET socket)
This program will print all of your computer's IP addresses:
import std.socket;
import std.stdio;
void main()
{
foreach (addr; getAddress(Socket.hostName))
writeln(addr.toAddrString());
}
This includes IPv6 addresses. You can filter the address family
by checking addr's addressFamily property.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 16:13:33 UTC, Dicebot wrote: It results in all addresses you hostname resolvs to. On all desktop linux machines /etc/hosts is configured to resolve hostname to localhost by default. On servers it usually resolves to externally accessible one. Update: I have just checked and this is actually distro-specific right now. My Arch box does not have that /etc/hosts entry and resolves host name to whatever first configured network interface has. Ubuntu does have explicit host name entry in /etc/hosts which resolves to localhost.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 16:02:33 UTC, Craig Dillabaugh wrote: This computer is on a network with dynamically assigned IP address (DHCP). So shouldn't the 10.1.101.52 address have been reported? Nope. In out-of-the-box simple network setups (i.e. home network in the form PC/laptop - router - internet) the address resolution won't go further than your hosts file, which in turn will always give you back the loopback address (more specifically, the address that is specified for the hostname in aforementioned file). That's why both I and Dicebot mentioned there isn't any real way to query your local addresses without any live connection: only when a socket has a connection within a particular network can you tell your own IP address in that network. The address itself would depend on the network setup, your local routing configuration, etc. Your machine can have several network adaptors (ethernet boards, Wi-Fi, etc.), each configured with (numerous) routing setups, plus the routers they're connected to have their own routing setups... This can go on and on.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 16:13:33 UTC, Dicebot wrote: On Tuesday, 4 February 2014 at 16:02:33 UTC, Craig Dillabaugh wrote: However if I run /sbin/ifconfig I get: enp7s0Link encap:Ethernet HWaddr 50:E5:49:9B:29:49 inet addr:10.1.101.52 Bcast:10.1.101.255 Mask:255.255.255.0 inet6 addr: fe80::52e5:49ff:fe9b:2949/64 Scope:Link loLink encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host This computer is on a network with dynamically assigned IP address (DHCP). So shouldn't the 10.1.101.52 address have been reported? It results in all addresses you hostname resolvs to. On all desktop linux machines /etc/hosts is configured to resolve hostname to localhost by default. On servers it usually resolves to externally accessible one. Thanks.
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 13:24:59 UTC, Dicebot wrote: On Tuesday, 4 February 2014 at 13:21:54 UTC, Stanislav Blinov wrote: Worth noting that this solution is not reliable in general either because your server can possibly have complicated routing configurations that will make, for example, LAN destination packets go via different network interface than WAN destination ones. It is probably better to tell what high-level problem you are trying to solve to find most useful compromise. I'm setting up a simple local network enabling me to connect phones to the computer through the local wi-fi. The simplest way i could think of to make this work without relying on an external server was to simply broadcast the ip and port to all machines in the network.(Btw by server i mean my / my project groups windows boxes). So well the problem is that i need a way for the phones to find running servers on the LAN.
Re: How can i find my LAN IP Address using std.socket?
Am Tue, 04 Feb 2014 16:19:08 + schrieb Stanislav Blinov stanislav.bli...@gmail.com: On Tuesday, 4 February 2014 at 16:02:33 UTC, Craig Dillabaugh wrote: This computer is on a network with dynamically assigned IP address (DHCP). So shouldn't the 10.1.101.52 address have been reported? Nope. In out-of-the-box simple network setups (i.e. home network in the form PC/laptop - router - internet) the address resolution won't go further than your hosts file, which in turn will always give you back the loopback address (more specifically, the address that is specified for the hostname in aforementioned file). That's why both I and Dicebot mentioned there isn't any real way to query your local addresses without any live connection: only when a socket has a connection within a particular network can you tell your own IP address in that network. The address itself would depend on the network setup, your local routing configuration, etc. Your machine can have several network adaptors (ethernet boards, Wi-Fi, etc.), each configured with (numerous) routing setups, plus the routers they're connected to have their own routing setups... This can go on and on. As a last resort there are always OS specific APIs to iterate network interfaces. For example, for linux: http://man7.org/linux/man-pages/man3/getifaddrs.3.html (Of course this doesn't tell you at all whether a local IP-address is actually routable. And you probably have to figure out if you got a link local / ULA IPv6 or a global one)
Re: How can i find my LAN IP Address using std.socket?
On Tuesday, 4 February 2014 at 20:19:14 UTC, TheFlyingFiddle wrote: I'm setting up a simple local network enabling me to connect phones to the computer through the local wi-fi. The simplest way i could think of to make this work without relying on an external server was to simply broadcast the ip and port to all machines in the network.(Btw by server i mean my / my project groups windows boxes). So well the problem is that i need a way for the phones to find running servers on the LAN. I think it is close to impossible to do in portable way. Most reliable approach is to get list of all configured network interfaces via posix functions (or via `system` call as least resort), filter out lo and broadcast message for every such interface. I think you can also filter only wireless interfaces that way relatively easily too.
