networking - 创建PNET数据链接 channel 时出现Rust错误 “PermissionDenied: Operation Not Permitted”

Question

pnet's main doc page上的“以太网回显服务器”示例中使用的示例数据链路 channel 创建代码包括以下代码段:

// Create a new channel, dealing with layer 2 packets
    let (mut tx, mut rx) = match datalink::channel(&interface, Default::default()) {
        Ok(Ethernet(tx, rx)) => (tx, rx),
        Ok(_) => panic!("Unhandled channel type"),
        Err(e) => panic!("An error occurred when creating the datalink channel: {}", e)
    };

这在我的CentOS7上不起作用，抛出错误: thread 'main' panicked at 'An error occurred when creating the datalink channel: Os { code: 1, kind: PermissionDenied, message: "Operation not permitted" }', src/bin/main.rs:83:27使用上面的内容或更简单地重新创建:

use pnet::datalink;
fn main() {
    for i in datalink::interfaces() {
        println!("{}", i.name);
        match datalink::channel(&i, Default::default()) {
            Ok(_) => println!("OK"),
            Err(_) => println!("ERR")
        }
    }
}

Answer 1

pnet试图打开需要root权限或CAP_NET_RAW功能的raw socket。这会导致“操作不允许”错误。以root身份运行可解决此问题。