feat(network): add DNS servers configuration

[M0dEx]

Added DNS configuration for Linux, FreeBSD and MacOS (Windows TBD).

Bumped MSRV to 1.80 due to std::sync::LazyLock.

Closes #76.

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 12 lines in your changes missing coverage. Please review.

Project coverage is 81.65%. Comparing base (b4ac966) to head (c7b1f3d).
Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
src/utils/command.rs	0.00%	10 Missing ⚠️
src/client.rs	88.88%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #83      +/-   ##
==========================================
+ Coverage   79.71%   81.65%   +1.93%     
==========================================
  Files          18       16       -2     
  Lines         991      943      -48     
==========================================
- Hits          790      770      -20     
+ Misses        201      173      -28     

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[bonianchen]

Do DNS server need to be IP address all the time ?
I mean ... how about some DNS server, such as "ns1.dnsowl.com" ?

I'm a rust lang beginner. Here's how I workaround such case:

[Within src/client.rs]

use rsdns;

async fn resolve_address(lookup_addr: &str, dns_server_addr: &str) -> Result<SocketAddr> {
    if dns_server_addr.len() == 0 {
        lookup_addr.to_socket_addrs()?.next().ok_or_else(|| {
            anyhow!(
                "Connection string '{}' is invalid",
                lookup_addr
            )
        })
    } else {
        let dns_server = dns_server_addr.to_socket_addrs()?.next().unwrap();
        let dns_server_config = rsdns::clients::ClientConfig::with_nameserver(dns_server);
        print!("Query {:?} from DNS {:?}\n", lookup_addr, dns_server_config);
        let mut dns_server_query = rsdns::clients::tokio::Client::new(dns_server_config).await?;

        let mut lookup_addr_itor = lookup_addr.split(':');
        let rrset = dns_server_query.query_rrset::<rsdns::records::data::A>(
            lookup_addr_itor.next().unwrap(), rsdns::records::Class::IN).await?;
        let lookup_ip = rrset.rdata.into_iter().next().unwrap().address;
        print!("Query {:?} get {:?}\n", lookup_addr, lookup_ip);
        let lookup_port_no = lookup_addr_itor.next().unwrap()
            .parse::<u16>().unwrap();
        Ok(SocketAddr::new(std::net::IpAddr::V4(lookup_ip), lookup_port_no ))
    }
}

[M0dEx]

Do DNS server need to be IP address all the time ? I mean ... how about some DNS server, such as "ns1.dnsowl.com" ?

I'm a rust lang beginner. Here's how I workaround such case:

[Within src/client.rs]

use rsdns;

async fn resolve_address(lookup_addr: &str, dns_server_addr: &str) -> Result<SocketAddr> {
    if dns_server_addr.len() == 0 {
        lookup_addr.to_socket_addrs()?.next().ok_or_else(|| {
            anyhow!(
                "Connection string '{}' is invalid",
                lookup_addr
            )
        })
    } else {
        let dns_server = dns_server_addr.to_socket_addrs()?.next().unwrap();
        let dns_server_config = rsdns::clients::ClientConfig::with_nameserver(dns_server);
        print!("Query {:?} from DNS {:?}\n", lookup_addr, dns_server_config);
        let mut dns_server_query = rsdns::clients::tokio::Client::new(dns_server_config).await?;

        let mut lookup_addr_itor = lookup_addr.split(':');
        let rrset = dns_server_query.query_rrset::<rsdns::records::data::A>(
            lookup_addr_itor.next().unwrap(), rsdns::records::Class::IN).await?;
        let lookup_ip = rrset.rdata.into_iter().next().unwrap().address;
        print!("Query {:?} get {:?}\n", lookup_addr, lookup_ip);
        let lookup_port_no = lookup_addr_itor.next().unwrap()
            .parse::<u16>().unwrap();
        Ok(SocketAddr::new(std::net::IpAddr::V4(lookup_ip), lookup_port_no ))
    }
}

I think there are some possible privacy concerns when specifying DNS servers using an FQDN.

So, for now, I feel Quincy should only support specifying DNS servers by their IP address, similar to WireGuard.