dns和udp解析测试

beiha***

建议用 1.1.1.1 而不是用阿里云的 223.5.5.5


因为1.1.1.1的回应  对于测试来说 是比较友好的

很多时候 你发给阿里云的 也许连回应都收不到

尤其是一些比较奇怪的包 不合法的包等等

rust可以用simple-dns这个crate包用于测试dns协议的解析和封装

1. use std::net::UdpSocket;
   
2. 
   
3. use simple_dns::*;
   
4. use simple_dns::rdata::*;
   
5. 
   
6. 
   
7. fn main() {
   
8. 
   
9.     let mut packet = Packet::new_query(1);
   
10. 
    
11.     let question = Question::new(Name::new_unchecked("_srv._udp.local"), TYPE::TXT.into(), CLASS::IN.into(), false);
    
12.     packet.questions.push(question);
    
13. 
    
14.     let resource = ResourceRecord::new(Name::new_unchecked("_srv._udp.local"), CLASS::IN, 10, RData::A(A { address: 10 }));
    
15.     packet.additional_records.push(resource);
    
16. 
    
17.     // Write the packet in the provided buffer;
    
18.     let mut bytes = [0u8; 200];
    
19.     assert!(packet.write_to(&mut &mut bytes[..]).is_ok());
    
20. 
    
21.     let socket = UdpSocket::bind("0.0.0.0:0").expect("couldn't bind to address");
    
22.    
    
23.    
    
24.     match socket.connect("1.1.1.1:53") {
    
25.         Ok(r) => println!("{:?}",r),
    
26.         Err(e) => println!("{:?}",e),
    
27.     }
    
28. 
    
29.     socket.send(&bytes).expect("couldn't send message");
    
30. 
    
31.     let mut buf = [0; 1024];
    
32.     match socket.recv(&mut buf) {
    
33.         Ok(received) => println!("received {received} bytes {:?}", &buf[..received]),
    
34.         Err(e) => println!("recv function failed: {e:?}"),
    
35.     }
    
36.    
    
37.    
    
38. }
    

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simple-dns = "0.7.0"

beiha***

1. packet.set_flags(PacketFlag::RECURSION_DESIRED);

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注意把 递归 设置上  不然除非大热门域名  容易出现空的回复