如何從NSData中提取IP地址和端口號

Question

- (void)readData{ 
    int      err; 
    int      sock; 
    struct sockaddr_storage addr; 
    socklen_t    addrLen; 
    uint8_t     buffer[65536]; 
    ssize_t     bytesRead; 

    sock = CFSocketGetNative(self->_cfSocket); 

    addrLen = sizeof(addr); 
    bytesRead = recvfrom(sock, buffer, sizeof(buffer), 0, (struct sockaddr *) &addr, &addrLen); 
    if (bytesRead < 0) { 
     err = errno; 
    } else if (bytesRead == 0) { 
     err = EPIPE; 
    } else { 
     NSData * dataObj; 
     NSData * addrObj; 

     err = 0; 

     dataObj = [NSData dataWithBytes:buffer length:bytesRead]; 
     addrObj = [NSData dataWithBytes:&addr length:addrLen ]; 

     // Tell the delegate about the data. 
     NSLog(@"receive data"); 

     if ((self.delegate != nil) && [self.delegate respondsToSelector:@selector(socket:didReceiveData:fromAddress:)]) { 
      [self.delegate socket:self didReceiveData:dataObj fromAddress:addrObj]; 
     } 
    } 

    if (err != 0) { 
     NSLog(@"Did Receive Error"); 
    } 
} 

addrObj是NSData，如何從addrObj中提取IP地址和端口號？

Answer 1

我認爲你不需要使用NSData對象來提取地址。我使用下面的代碼來提取IP地址和端口從我讀：

- (void)readData 
{ 
    int      sock = CFSocketGetNative(self.cfSocket); 
    struct sockaddr_storage address; 
    socklen_t    len = sizeof(address); 
    uint8_t     buffer[65536]; 
    ssize_t     bytesRead = recvfrom(sock, buffer, sizeof(buffer), 0, 
             (struct sockaddr *) &address, &len); 
    int      error = (bytesRead < 0) ? errno : 0; 

    NSLog(@"%zi bytes read from %s:%d...", bytesRead, 
      inet_ntoa(((struct sockaddr_in*)&address)->sin_addr), 
      ((struct sockaddr_in*)&address)->sin_port); 
    ... 
} 

輸出示例：

 
2011-05-04 10:41:57.051,-[myClass readData],5 bytes read from 10.112.15.81:37259... 
2011-05-04 10:41:57.052,-[myClass readData] read: 
"Hello"