如何在得到SOCKADDR_STORAGE，后 从中获取 IP 地址

[lx_neteasy]

SOCKADDR_STORAGE addr；

len2 = recvfrom(sock,(char *)packetbuffer,(int)len,0,(LPSOCKADDR)&addr,&fromlen);
后该 怎么得到它的地址呐？大虾帮忙！！！

[自由的风]

SOCKADDR_STORAGE??????????????????????????????????

这是什么类型，我把MSDN查了个遍，也没有看到这种东西
int recvfrom(
SOCKET s,
char FAR* buf,
int len,
int flags,
struct sockaddr FAR *from,
int FAR *fromlen
);

[joy]

LPFN_GETACCEPTEXSOCKADDRS lpfnGetAcceptExSockaddrs=NULL;

// Load the GetAcceptExSockaddrs function

lpfnGetAcceptExSockaddrs(
buf,
buflen - ((sizeof(SOCKADDR_IN) + 16) * 2),
sizeof(SOCKADDR_IN) + 16,
sizeof(SOCKADDR_IN) + 16,
&lpLocalSockaddr,
&LocalSockaddrLen,
&lpRemoteSockaddr,
&RemoteSockaddrLen
);

后, 怎么得到lpLocalSockaddr, or lpRemoteSockaddr的地址呐？大虾帮忙！！！

[kingzai]

// Function: ServerThread
//
// Description:
// This routine services a single server socket. For TCP this means accept
// a client connection and then recv and send in a loop. When the client
// closes the connection, wait for another client, etc. For UDP, we simply
// sit in a loop and recv a datagram and echo it back to its source. For any
// error, this routine exits.
//
DWORD WINAPI ServerThread(LPVOID lpParam)
{
SOCKET s, // Server socket
sc = INVALID_SOCKET; // Client socket (TCP)
SOCKADDR_STORAGE from;
char Buffer[DEFAULT_BUFFER_LEN],
servstr[NI_MAXSERV],
hoststr[NI_MAXHOST];
int socket_type,
retval,
fromlen,
bytecount;

// Retrieve the socket handle
s = (SOCKET) lpParam;

// Get the socket type back
fromlen = sizeof(socket_type);
retval = getsockopt(s, SOL_SOCKET, SO_TYPE, (char *)&socket_type, &fromlen);
if (retval == INVALID_SOCKET)
{
fprintf(stderr, "getsockopt(SO_TYPE) failed: %d\n", WSAGetLastError());
goto cleanup;
}

while (1)
{
fromlen = sizeof(from);

if (socket_type == SOCK_STREAM)
{
if (sc != INVALID_SOCKET)
{
//
// If we have a client connection recv and send until done
//
bytecount = recv(sc, Buffer, DEFAULT_BUFFER_LEN, 0);
if (bytecount == SOCKET_ERROR)
{
fprintf(stderr, "recv failed: %d\n", WSAGetLastError());
goto cleanup;
}
else if (bytecount == 0)
{
// Client connection was closed
retval = shutdown(sc, SD_SEND);
if (retval == SOCKET_ERROR)
{
fprintf(stderr, "shutdown failed: %d\n", WSAGetLastError());
goto cleanup;
}

closesocket(sc);
sc = INVALID_SOCKET;
}
else
{
printf("read %d bytes\n", bytecount);

//
// Now echo the data back
//

bytecount = send(sc, Buffer, bytecount, 0);
if (bytecount == SOCKET_ERROR)
{
fprintf(stderr, "send failed: %d\n", WSAGetLastError());
goto cleanup;
}

printf("wrote %d bytes\n", bytecount);
}
}
else
{
//
// No client connection so wait for one
//
sc = accept(s, (SOCKADDR *)&from, &fromlen);
if (sc == INVALID_SOCKET)
{
fprintf(stderr, "accept failed: %d\n", WSAGetLastError());
goto cleanup;
}

// Display the client's address
retval = getnameinfo(
(SOCKADDR *)&from,
fromlen,
hoststr,
NI_MAXHOST,
servstr,
NI_MAXSERV,
NI_NUMERICHOST | NI_NUMERICSERV
);
if (retval != 0)
{
fprintf(stderr, "getnameinfo failed: %d\n", retval);
goto cleanup;
}

printf("Accepted connection from host %s and port %s\n",
hoststr, servstr);
}
}
else
{
//
// Receive and send data
//
bytecount = recvfrom(s, Buffer, DEFAULT_BUFFER_LEN, 0, (SOCKADDR *)&from, &fromlen);
if (bytecount == SOCKET_ERROR)
{
//
// We may get WSAECONNRESET errors in response to ICMP port unreachable
// messages so we'll just ignore those
//
if (WSAGetLastError() != WSAECONNRESET)
{
fprintf(stderr, "recvfrom failed; %d\n", WSAGetLastError());
goto cleanup;
}
else
{
continue;
}
}

//
// Display the source of the datagram
//
retval = getnameinfo(
(SOCKADDR *)&from,
fromlen,
hoststr,
NI_MAXHOST,
servstr,
NI_MAXSERV,
NI_NUMERICHOST | NI_NUMERICSERV
);
if (retval != 0)
{
fprintf(stderr, "getnameinfo failed: %d\n", retval);
goto cleanup;
}

printf("read %d bytes from host %s and port %s\n",
bytecount, hoststr, servstr);

//
// Echo the datagram back
//
bytecount = sendto(s, Buffer, bytecount, 0, (SOCKADDR *)&from, fromlen);
if (bytecount == SOCKET_ERROR)
{
fprintf(stderr, "sendto failed: %d\n", WSAGetLastError());
goto cleanup;
}

printf("sent %d bytes to host %s and port %s\n",
bytecount, hoststr, servstr);
}

}

cleanup:

// Close the client connection if present
if (sc != INVALID_SOCKET)
{
closesocket(sc);
sc = INVALID_SOCKET;
}

ExitThread(0);
}

[kingzai]

getnameinfo function

[xuzheng318]

msdn：
Application developers use only the ss_family member of the SOCKADDR_STORAGE. The remaining three members ensure the SOCKADDR_STORAGE is padded appropriately to achieve 64-bit alignment. Such alignment enables protocol-specific socket address data structures to access fields within a SOCKADDR_STORAGE structure without alignment problems. With its padding, the SOCKADDR_STORAGE structure is 128 bytes in length.

The first field of the SOCKADDR_STORAGE structure is isomorphic with the sockaddr structure to enable simplified transition from sockaddr to SOCKADDR_STORAGE.

For more information about platform-independent SOCKADDR_STORAGE implementation recommendations, refer to RFC 2553, available at www.ietf.org.