singrdk/base/Libraries/System.Net/Dns.cs

337 lines
13 KiB
C#

////////////////////////////////////////////////////////////////////////////////
//
// Microsoft Research Singularity
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// Notes:
// Ported from the Coriolis code base, with extensive changes to use
// the channel interface to our NetStack instead of native calls.
//
namespace System.Net
{
using System.Collections;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.Net.IP;
using NetStack.Contracts;
using NetStack.Channels.Public;
using Microsoft.SingSharp;
using Microsoft.Singularity;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Directory;
public sealed class Dns {
// This is the slot we use to store the per-thread channel to the NetStack
private static LocalDataStoreSlot DnsSlot = null;
private static LocalDataStoreSlot IPSlot = null;
private static object DnsSlotLock = new object(); // Used for initialization
private static object IPSlotLock = new object(); // ditto
//
// Constructor is private to prevent instantiation
//
private Dns() {
// Shouldn't ever be called
}
// All threads share a LocalDataStoreSlot object that identifies a thread-local
// data "slot" that each thread can use. This object must be created in a thread-
// safe way the first time it becomes necessary. See Thread.AllocateDataSlot().
internal static LocalDataStoreSlot SafeSlotFetchOrInitialize(ref LocalDataStoreSlot slot,
object slotLock)
{
// This initialization sequence is meant to be thread-safe
if (slot == null) {
lock (slotLock) {
if (slot == null) {
slot = Thread.AllocateDataSlot();
}
}
}
return slot;
}
// Must be balanced with a call to ReleaseDnsConnection()!
internal static DNSContract.Imp! GetDnsConnection()
{
LocalDataStoreSlot slot = SafeSlotFetchOrInitialize(ref DnsSlot, DnsSlotLock);
if (Thread.GetData(slot) == null) {
// We haven't created a channel for this thread yet. Create one.
DNSContract.Imp! dnsImp;
DNSContract.Exp! dnsExp;
DirectoryServiceContract.Imp epNS = DirectoryService.NewClientEndpoint();
DNSContract.NewChannel(out dnsImp, out dnsExp);
try {
epNS.SendBind(Bitter.FromString2(DNSContract.ModuleName), dnsExp);
switch receive {
case epNS.NakBind(ServiceContract.Exp:Start rejectedEP, error) :
if (rejectedEP != null) {
delete rejectedEP;
}
delete dnsImp;
// Do nothing; we will return null below.
break;
case epNS.AckBind() :
// Success; put our remaining end of the channel
// into thread-local storage.
dnsImp.RecvReady();
TRef<DNSContract.Imp:ReadyState> dnsConnHolder = new TRef<DNSContract.Imp:ReadyState>(dnsImp);
Thread.SetData(slot, dnsConnHolder);
break;
}
}
finally {
delete epNS;
}
}
// By now there should definitely be a channel in our thread-local storage.
TRef<DNSContract.Imp:ReadyState>! connHolder = (TRef<DNSContract.Imp:ReadyState>!)Thread.GetData(slot);
return connHolder.Acquire();
}
internal static void ReleaseDnsConnection([Claims] DNSContract.Imp:ReadyState! connection)
{
// Put the channel back into thread-local storage.
TRef<DNSContract.Imp:ReadyState>! dnsConnHolder = (TRef<DNSContract.Imp:ReadyState>!)Thread.GetData(DnsSlot);
dnsConnHolder.Release(connection);
}
// Must be balanced with a call to ReleaseIPConnection()!
internal static IPContract.Imp! GetIPConnection()
{
LocalDataStoreSlot slot = SafeSlotFetchOrInitialize(ref IPSlot, IPSlotLock);
if (Thread.GetData(slot) == null) {
IPContract.Imp! ipImp;
IPContract.Exp! ipExp;
DirectoryServiceContract.Imp epNS = DirectoryService.NewClientEndpoint();
IPContract.NewChannel(out ipImp, out ipExp);
try {
epNS.SendBind(Bitter.FromString2(IPContract.ModuleName), ipExp);
switch receive {
case epNS.NakBind(ServiceContract.Exp:Start rejectedEP, error) :
// Do nothing; we will return null below.
delete ipImp;
if (rejectedEP != null) {
delete rejectedEP;
}
break;
case epNS.AckBind() :
// Success; put our remaining end of the channel
// into thread-local storage.
ipImp.RecvReady();
TRef<IPContract.Imp:ReadyState> ipConnHolder = new TRef<IPContract.Imp:ReadyState>(ipImp);
Thread.SetData(slot, ipConnHolder);
break;
}
}
finally {
delete epNS;
}
}
TRef<IPContract.Imp:ReadyState>! connHolder = (TRef<IPContract.Imp:ReadyState>!)Thread.GetData(slot);
return connHolder.Acquire();
}
internal static void ReleaseIPConnection([Claims] IPContract.Imp:ReadyState! connection)
{
// Put the channel back into thread-local storage.
TRef<IPContract.Imp:ReadyState>! ipConnHolder = (TRef<IPContract.Imp:ReadyState>!)Thread.GetData(IPSlot);
ipConnHolder.Release(connection);
}
public static IPHostEntry GetHostByName(string hostName) {
if (hostName == null) {
throw new ArgumentNullException("hostName");
}
return InternalGetHostByName(hostName);
}
internal static IPHostEntry InternalGetHostByName(string hostName) {
return InternalResolve(hostName);
} // GetHostByName
public static IPAddress[] GetLocalHostAddresses() {
IPAddress[] retval;
IPContract.Imp ipConn = GetIPConnection();
try {
char[][]! in ExHeap ifList;
ArrayList addresses = new ArrayList();
ipConn.SendGetInterfaces();
ipConn.RecvInterfaceList(out ifList);
try {
for (int i = 0; i < ifList.Length; ++i) {
expose(ifList[i]) {
ipConn.SendGetInterfaceState((!)ifList[i]);
ifList[i] = null;
switch receive {
case ipConn.InterfaceNotFound() :
throw new SocketException(SocketErrors.SocketError);
break;
case ipConn.InterfaceState(InterfaceInfo ifInfo) :
{
// Copy out all of this interface's addresses
InterfaceIPInfo[] in ExHeap ipConfigs = ifInfo.ipConfigs;
if (ipConfigs != null) {
for (int j = 0; j < ipConfigs.Length; ++j) {
addresses.Add(new IPAddress(ipConfigs[j].address));
}
}
ifInfo.Dispose();
}
break;
}
}
}
}
finally {
delete ifList; // This should hold only NULLs by now
}
return (IPAddress[])addresses.ToArray(typeof(IPAddress));
}
finally {
ReleaseIPConnection(ipConn);
}
} // GetLocalHostAddresses
public static IPHostEntry GetHostByAddress(string address) {
if (address == null) {
throw new ArgumentNullException("address");
}
IPHostEntry ipHostEntry = InternalGetHostByAddress(IPAddress.Parse(address));
return ipHostEntry;
} // GetHostByAddress
public static IPHostEntry GetHostByAddress(IPAddress address) {
if (address == null) {
throw new ArgumentNullException("address");
}
IPHostEntry ipHostEntry = InternalGetHostByAddress(address);
return ipHostEntry;
} // GetHostByAddress
internal static IPHostEntry InternalGetHostByAddress(IPAddress! address)
{
// We only support IPv4 addresses under Singularity!
if (address.AddressFamily != AddressFamily.InterNetwork) {
//
// Protocol not supported
//
throw new SocketException(SocketErrors.WSAEPROTONOSUPPORT);
}
// Turn the address into a string and resolve it
return InternalResolve(address.ToString());
return null;
} // InternalGetHostByAddress
// host can be either a host's textual name, or the string of an address
internal static IPHostEntry! InternalResolve(string host)
{
DNSContract.Imp dnsConn = GetDnsConnection();
try {
string[] aliases;
IPv4[] addrs;
if (DNSImpConnection.Resolve(dnsConn, host, out aliases, out addrs)) {
assert aliases != null;
assert addrs != null;
return DNSInfoToIPHostEntry(aliases, addrs); }
else {
throw new SocketException(SocketErrors.WSAHOST_NOT_FOUND);
}
}
finally {
ReleaseDnsConnection(dnsConn);
}
} // InternalResolve
internal static IPHostEntry! DNSInfoToIPHostEntry(string[]! aliases, IPv4[]! addrs)
{
IPHostEntry retval = new IPHostEntry();
IPAddress[] addressList = new IPAddress[addrs.Length];
for (int i = 0; i < addrs.Length; ++i) {
addressList[i] = new IPAddress(addrs[i]);
}
string[] resultAliases = new string[aliases.Length - 1];
for (int i = 1; i < aliases.Length; ++i) {
resultAliases[i] = aliases[i];
}
retval.Aliases = resultAliases;
retval.AddressList = addressList;
retval.HostName = aliases[0];
return retval;
}
public static string GetHostName() {
IPContract.Imp ipConn = GetIPConnection();
try {
char[]! in ExHeap hostName;
ipConn.SendGetHostName();
ipConn.RecvHostName(out hostName);
string strHostName = Bitter.ToString(hostName);
delete hostName;
return strHostName;
}
finally {
ReleaseIPConnection(ipConn);
}
}
public static IPAddress[] ResolveToAddresses(string hostName) {
IPHostEntry entry = Resolve(hostName);
return entry.AddressList;
}
//
// Note that in the case of multiple IP addresses, the address returned is
// chosen arbitrarily.
//
public static IPHostEntry! Resolve(string hostName) {
if (hostName == null) {
throw new ArgumentNullException("hostName");
}
return InternalResolve(hostName);
}
}
}