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authorMattes D <github@xoft.cz>2015-01-24 09:27:55 +0100
committerMattes D <github@xoft.cz>2015-01-24 09:27:55 +0100
commitf91de20ca14725a41ea082b61a98477427c78528 (patch)
tree7925214f6faec943d0bdffc3c2706eed8fe744e9 /src/OSSupport/HostnameLookup.cpp
parentMerge pull request #1712 from UltraCoderRU/fix_coverity (diff)
parentcNetwork: Added self pointers to keep objects alive for callbacks. (diff)
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Diffstat (limited to '')
-rw-r--r--src/OSSupport/HostnameLookup.cpp124
1 files changed, 124 insertions, 0 deletions
diff --git a/src/OSSupport/HostnameLookup.cpp b/src/OSSupport/HostnameLookup.cpp
new file mode 100644
index 000000000..3a2997ffd
--- /dev/null
+++ b/src/OSSupport/HostnameLookup.cpp
@@ -0,0 +1,124 @@
+
+// HostnameLookup.cpp
+
+// Implements the cHostnameLookup class representing an in-progress hostname-to-IP lookup
+
+#include "Globals.h"
+#include "HostnameLookup.h"
+#include <event2/dns.h>
+#include "NetworkSingleton.h"
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cHostnameLookup:
+
+cHostnameLookup::cHostnameLookup(cNetwork::cResolveNameCallbacksPtr a_Callbacks):
+ m_Callbacks(a_Callbacks)
+{
+}
+
+
+
+
+
+void cHostnameLookup::Lookup(const AString & a_Hostname)
+{
+ // Store the hostname for the callback:
+ m_Hostname = a_Hostname;
+
+ // Start the lookup:
+ // Note that we don't have to store the LibEvent lookup handle, LibEvent will free it on its own.
+ evutil_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 = EVUTIL_AI_CANONNAME;
+ evdns_getaddrinfo(cNetworkSingleton::Get().GetDNSBase(), a_Hostname.c_str(), nullptr, &hints, Callback, this);
+}
+
+
+
+
+
+void cHostnameLookup::Callback(int a_ErrCode, evutil_addrinfo * a_Addr, void * a_Self)
+{
+ // Get the Self class:
+ cHostnameLookup * Self = reinterpret_cast<cHostnameLookup *>(a_Self);
+ ASSERT(Self != nullptr);
+
+ // If an error has occurred, notify the error callback:
+ if (a_ErrCode != 0)
+ {
+ Self->m_Callbacks->OnError(a_ErrCode, evutil_socket_error_to_string(a_ErrCode));
+ cNetworkSingleton::Get().RemoveHostnameLookup(Self);
+ return;
+ }
+
+ // Call the success handler for each entry received:
+ bool HasResolved = false;
+ evutil_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);
+ 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);
+ 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)
+ }
+ }
+ Self->m_Callbacks->OnNameResolved(Self->m_Hostname, IP);
+ HasResolved = true;
+ } // for (a_Addr)
+
+ // If only unsupported families were reported, call the Error handler:
+ if (!HasResolved)
+ {
+ Self->m_Callbacks->OnError(DNS_ERR_NODATA, "The name does not resolve to any known address.");
+ }
+ else
+ {
+ Self->m_Callbacks->OnFinished();
+ }
+ evutil_freeaddrinfo(OrigAddr);
+ cNetworkSingleton::Get().RemoveHostnameLookup(Self);
+}
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cNetwork API:
+
+bool cNetwork::HostnameToIP(
+ const AString & a_Hostname,
+ cNetwork::cResolveNameCallbacksPtr a_Callbacks
+)
+{
+ auto Lookup = std::make_shared<cHostnameLookup>(a_Callbacks);
+ cNetworkSingleton::Get().AddHostnameLookup(Lookup);
+ Lookup->Lookup(a_Hostname);
+ return true;
+}
+
+
+
+