如何在得到SOCKADDR_STORAGE，后 从中获取 IP 地址

Question

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！！！

Answer 1

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            
);

Answer 2

LPFN_GETACCEPTEXSOCKADDRS lpfnGetAcceptExSockaddrs=NULL;// Load the GetAcceptExSockaddrs functionlpfnGetAcceptExSockaddrs(
         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！！！

Answer 3

// 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);
}

Answer 4

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.