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cuberite-2a/src/OSSupport/HostnameLookup.cpp
2017-06-16 14:06:27 +02:00

137 lines
3.2 KiB
C++

// HostnameLookup.cpp
// Implements the cHostnameLookup class representing an in-progress hostname-to-IP lookup
#include "Globals.h"
#include "HostnameLookup.h"
#include "NetworkSingleton.h"
#include "GetAddressInfoError.h"
////////////////////////////////////////////////////////////////////////////////
// cHostnameLookup:
cHostnameLookup::cHostnameLookup(const AString & a_Hostname, cNetwork::cResolveNameCallbacksPtr a_Callbacks):
m_Callbacks(a_Callbacks),
m_Hostname(a_Hostname)
{
}
void cHostnameLookup::Lookup(const AString & a_Hostname, cNetwork::cResolveNameCallbacksPtr a_Callbacks)
{
// Cannot use std::make_shared here, constructor is not accessible
cHostnameLookupPtr Lookup{ new cHostnameLookup(a_Hostname, std::move(a_Callbacks)) };
// Note the Lookup object is owned solely by this lambda which is destroyed after it runs
cNetworkSingleton::Get().GetLookupThread().ScheduleLookup([=]()
{
// Start the lookup:
addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_protocol = IPPROTO_TCP;
hints.ai_socktype = SOCK_STREAM;
hints.ai_family = AF_UNSPEC;
hints.ai_flags = AI_CANONNAME;
addrinfo * Result;
int ErrCode = getaddrinfo(Lookup->m_Hostname.c_str(), nullptr, &hints, &Result);
Lookup->Callback(ErrCode, Result);
});
}
void cHostnameLookup::Callback(int a_ErrCode, addrinfo * a_Addr)
{
// If an error has occurred, notify the error callback:
if (a_ErrCode != 0)
{
m_Callbacks->OnError(a_ErrCode, ErrorString(a_ErrCode));
return;
}
// Call the success handler for each entry received:
bool HasResolved = false;
addrinfo * OrigAddr = a_Addr;
for (;a_Addr != nullptr; a_Addr = a_Addr->ai_next)
{
char IP[128];
switch (a_Addr->ai_family)
{
case AF_INET: // IPv4
{
sockaddr_in * sin = reinterpret_cast<sockaddr_in *>(a_Addr->ai_addr);
if (!m_Callbacks->OnNameResolvedV4(m_Hostname, sin))
{
// Callback indicated that the IP shouldn't be serialized to a string, just continue with the next address:
HasResolved = true;
continue;
}
evutil_inet_ntop(AF_INET, &(sin->sin_addr), IP, sizeof(IP));
break;
}
case AF_INET6: // IPv6
{
sockaddr_in6 * sin = reinterpret_cast<sockaddr_in6 *>(a_Addr->ai_addr);
if (!m_Callbacks->OnNameResolvedV6(m_Hostname, sin))
{
// Callback indicated that the IP shouldn't be serialized to a string, just continue with the next address:
HasResolved = true;
continue;
}
evutil_inet_ntop(AF_INET6, &(sin->sin6_addr), IP, sizeof(IP));
break;
}
default:
{
// Unknown address family, handle as if this entry wasn't received
continue; // for (a_Addr)
}
}
m_Callbacks->OnNameResolved(m_Hostname, IP);
HasResolved = true;
} // for (a_Addr)
// If only unsupported families were reported, call the Error handler:
if (!HasResolved)
{
m_Callbacks->OnError(EAI_NONAME, ErrorString(EAI_NONAME));
}
else
{
m_Callbacks->OnFinished();
}
freeaddrinfo(OrigAddr);
}
////////////////////////////////////////////////////////////////////////////////
// cNetwork API:
bool cNetwork::HostnameToIP(
const AString & a_Hostname,
cNetwork::cResolveNameCallbacksPtr a_Callbacks
)
{
cHostnameLookup::Lookup(a_Hostname, std::move(a_Callbacks));
return true;
}