Crate dns_lookup

dns_lookup

A small wrapper for libc to perform simple DNS lookups.

Two main functions are provided.

lookup_host

Given a hostname, return an Iterator the IP Addresses associated with it.

use dns_lookup::lookup_host;

  let hostname = "localhost";
  let ips: Vec<std::net::IpAddr> = lookup_host(hostname).unwrap();
  assert!(ips.contains(&"127.0.0.1".parse().unwrap()));

lookup_addr

Given an IP Address, return the reverse DNS entry (hostname) for the given IP Address.

use dns_lookup::lookup_addr;

  let ip: std::net::IpAddr = "127.0.0.1".parse().unwrap();
  let hostname = lookup_addr(&ip).unwrap();
  assert_eq!(hostname, "localhost");

getaddrinfo

use dns_lookup::{getaddrinfo, AddrInfoHints};

  let hostname = "localhost";
  let service = "ssh";
  let hints = AddrInfoHints {
    socktype: dns_lookup::SockType::Stream,
    .. AddrInfoHints::default()
  };
  let sockets =
    getaddrinfo(Some(hostname), Some(service), Some(hints))
      .unwrap().collect::<std::io::Result<Vec<_>>>().unwrap();

  for socket in sockets {
    // Try connecting to socket
    let _ = socket;
  }

getnameinfo

use dns_lookup::getnameinfo;
  use std::net::{IpAddr, SocketAddr};

  let ip: IpAddr = "127.0.0.1".parse().unwrap();
  let port = 22;
  let socket: SocketAddr = (ip, port).into();

  let (name, service) = match getnameinfo(&socket, 0) {
    Ok((n, s)) => (n, s),
    Err(e) => panic!("Failed to lookup socket {:?}", e),
  };

  println!("{:?} {:?}", name, service);
  let _ = (name, service);

Structs

AddrInfo	Struct that stores socket information, as returned by getaddrinfo.
AddrInfoHints	A struct used as the hints argument to getaddrinfo.
AddrInfoIter	An iterator of AddrInfo structs, wrapping a linked-list returned by getaddrinfo.

Enums

AddrFamily	Socket Address Family
ProtoFamily	Socket Protocol Family
SockType	Socket Type

Functions

getaddrinfo	Retrieve socket information for a host, service, or both. Acts as a thin wrapper around the libc getaddrinfo.
getnameinfo	Retrieve the name for a given IP and Service. Acts as a thin wrapper around the libc getnameinfo.
lookup_addr	Lookup the hostname of a given IP Address via DNS.
lookup_host	Lookup the address for a given hostname via DNS.