[WIP] Improve Windows support

Get gateway information using IP Helper API

src/interface.rs

@@ -19,6 +19,9 @@ impl MacAddr {
     pub fn address(&self) -> String {
         format!("{:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x}", self.0,self.1,self.2,self.3,self.4,self.5)
     }
+    pub fn zero() -> MacAddr {
+        MacAddr(0,0,0,0,0,0)
+    }
 }
 
 impl std::fmt::Display for MacAddr {
@@ -33,6 +36,7 @@ impl std::fmt::Display for MacAddr {
 pub struct Interface {
     pub index: u32,
     pub name: String,
+    pub description: Option<String>,
     pub mac_addr: Option<MacAddr>,
     pub ipv4: Vec<Ipv4Addr>,
     pub ipv6: Vec<Ipv6Addr>,
@@ -70,6 +74,7 @@ pub fn get_default_interface() -> Result<Interface, String> {
                     let interface: Interface = Interface{
                         index: iface.index,
                         name: iface.name,
+                        description: None,
                         mac_addr: mac_addr,
                         ipv4: ipv4_vec,
                         ipv6: ipv6_vec,

src/os/windows.rs

@@ -1,14 +1,64 @@
-use windows::Win32::NetworkManagement::IpHelper::{GetAdaptersInfo, IP_ADAPTER_INFO, IP_ADDR_STRING};
+use windows::Win32::Foundation::{ERROR_BUFFER_OVERFLOW, NO_ERROR};
+use windows::Win32::NetworkManagement::IpHelper::{GetAdaptersInfo, IP_ADAPTER_INFO, IP_ADDR_STRING, SendARP};
 use std::convert::TryInto;
 use std::mem;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+use std::ffi::CStr;
+use core::ffi::c_void;
 
-pub const ERROR_BUFFER_OVERFLOW: u32 = 111;
-pub const NO_ERROR: u32 = 0;
+use crate::interface::{Interface, MacAddr};
+use crate::gateway::Gateway;
 
-// Get network interface information using the IP Helper API
-// TODO: Make more rusty way...
+pub const EXCEPTION_INTERFACE_INDEX: u32 = 0;
+
+// Convert C string to Rust string without trailing null bytes
+fn bytes_to_string(bytes: &[u8]) -> String {
+    let result: String = match CStr::from_bytes_with_nul(bytes) {
+        Ok(cstr) => {
+            match cstr.to_str() {
+                Ok(rstr) => rstr.to_string(),
+                Err(_) => cstr.to_string_lossy().replace("\u{0}", "").to_string(),
+            }  
+        },
+        Err(_) => {
+            String::from_utf8_lossy(bytes).replace("\u{0}", "").to_string()
+        }
+    };
+    result
+}
+
+#[cfg(target_endian = "little")]
+fn htonl(val : u32) -> u32 {
+    let o3 = (val >> 24) as u8;
+    let o2 = (val >> 16) as u8;
+    let o1 = (val >> 8)  as u8;
+    let o0 =  val        as u8;
+    (o0 as u32) << 24 | (o1 as u32) << 16 | (o2 as u32) << 8 | (o3 as u32)
+}
+
+#[cfg(target_endian = "big")]
+fn htonl(val : u32) -> u32 {
+    val
+}
+
+fn get_mac_through_arp(src_ip: Ipv4Addr, dst_ip: Ipv4Addr) -> MacAddr {
+    let src_ip_int: u32 = htonl(u32::from(src_ip));
+    let dst_ip_int: u32 = htonl(u32::from(dst_ip));
+    let mut out_buf_len : u32 = 6;
+    let mut target_mac_addr: [u8; 6] =  [0; 6];
+    let res = unsafe { SendARP(dst_ip_int, src_ip_int, target_mac_addr.as_mut_ptr() as *mut c_void, &mut out_buf_len) };
+    if res == NO_ERROR {
+        MacAddr::new(target_mac_addr)
+    }else{
+        MacAddr::zero()
+    }
+}
+
+// Get network interfaces using the IP Helper API
+// TODO: Make more rusty ...
 // Reference: https://docs.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-getadaptersinfo
-pub fn get_interfaces() {
+pub fn get_interfaces() -> Vec<Interface> {
+    let mut interfaces: Vec<Interface> = vec![];
     let mut out_buf_len : u32 = mem::size_of::<IP_ADAPTER_INFO>().try_into().unwrap();
     let mut raw_adaptor_mem: Vec<u8> = Vec::with_capacity(out_buf_len  as usize);
     let mut p_adaptor: *mut IP_ADAPTER_INFO;
@@ -21,49 +71,118 @@ pub fn get_interfaces() {
 		}
 	}
     if res != NO_ERROR {
-        //TODO
-		println!("failed to get adapters info");
-        // for test
-		std::process::exit(1);
+        return interfaces;
 	}
     //Enumerate all adapters
 	p_adaptor = unsafe { mem::transmute(&raw_adaptor_mem) };
     while p_adaptor as u64 != 0 {
         unsafe {
-			let adapter = *p_adaptor;
-            let adapter_name = String::from_utf8_lossy(&adapter.AdapterName);
-            let adapter_desc = String::from_utf8_lossy(&adapter.Description);
-            let mac_addr = adapter.Address.to_vec();
-            println!("{} {} {} {} {:?}", adapter.Index, adapter.ComboIndex, adapter_name, adapter_desc, mac_addr);
+			let adapter: IP_ADAPTER_INFO = *p_adaptor;
+            if adapter.Index == EXCEPTION_INTERFACE_INDEX{
+                p_adaptor = (*p_adaptor).Next;
+                continue;
+            }
+            let adapter_name: String = bytes_to_string(&adapter.AdapterName);
+            let adapter_desc: String = bytes_to_string(&adapter.Description);
+            let mac_addr:[u8; 6] = adapter.Address[..6].try_into().unwrap_or([0, 0, 0, 0, 0, 0]);
             //Enumerate all IPs
+            let mut ipv4_vec: Vec<Ipv4Addr> = vec![];
+            let mut ipv6_vec: Vec<Ipv6Addr> = vec![];
             let mut p_ip_addr: *mut IP_ADDR_STRING;
             p_ip_addr = mem::transmute(&(*p_adaptor).IpAddressList);
             while p_ip_addr as u64 != 0 {
-                let ip_addr_string = *p_ip_addr;
-                let ip_addr = String::from_utf8_lossy(&ip_addr_string.IpAddress.String);
-                println!("{}", ip_addr);
+                let ip_addr_string: IP_ADDR_STRING = *p_ip_addr;
+                let ip_addr: String = bytes_to_string(&ip_addr_string.IpAddress.String);
+                match ip_addr.parse::<IpAddr>() {
+                    Ok(ip_addr) => {
+                        match ip_addr {
+                            IpAddr::V4(ipv4_addr) => {
+                                ipv4_vec.push(ipv4_addr);
+                            },
+                            IpAddr::V6(ipv6_addr) => {
+                                ipv6_vec.push(ipv6_addr);
+                            }
+                        }
+                    },
+                    Err(_) => {},
+                }
                 p_ip_addr = (*p_ip_addr).Next;
             }
             //Enumerate all gateways
+            let mut gateway_ips: Vec<IpAddr> = vec![];
             let mut p_gateway_addr: *mut IP_ADDR_STRING;
             p_gateway_addr = mem::transmute(&(*p_adaptor).GatewayList);
             while p_gateway_addr as u64 != 0 {
-                let gateway_addr_string = *p_gateway_addr;
-                let gateway_addr = String::from_utf8_lossy(&gateway_addr_string.IpAddress.String);
-                println!("{}", gateway_addr);
+                let gateway_addr_string: IP_ADDR_STRING = *p_gateway_addr;
+                let gateway_addr: String = bytes_to_string(&gateway_addr_string.IpAddress.String);
+                match gateway_addr.parse::<IpAddr>() {
+                    Ok(ip_addr) => {
+                        gateway_ips.push(ip_addr);
+                    },
+                    Err(_) => {},
+                }
                 p_gateway_addr = (*p_gateway_addr).Next;
             }
-            //TODO
+            let default_gateway: Option<Gateway> = match gateway_ips.get(0) {
+                Some(gateway_ip) => {
+                    let gateway_ip: IpAddr = *gateway_ip;
+                    let default_gateway: Option<Gateway> = if gateway_ip != IpAddr::V4(Ipv4Addr::UNSPECIFIED) {
+                        match gateway_ip {
+                            IpAddr::V4(dst_ip) => {
+                                if let Some(src_ip) = ipv4_vec.get(0) {
+                                    let mac_addr = get_mac_through_arp(*src_ip, dst_ip);
+                                    let gateway = Gateway {
+                                        mac_addr: mac_addr,
+                                        ip_addr: IpAddr::V4(dst_ip),
+                                    };
+                                    Some(gateway)
+                                }else{
+                                    None
+                                }
+                            },
+                            IpAddr::V6(_dst_ip) => {
+                                None
+                            },
+                        }
+                    }else{
+                        None
+                    };
+                    default_gateway
+                },
+                None => None,
+            };
+            let interface: Interface = Interface{
+                index: adapter.Index,
+                name: adapter_name,
+                description: Some(adapter_desc),
+                mac_addr: Some(MacAddr::new(mac_addr)),
+                ipv4: ipv4_vec,
+                ipv6: ipv6_vec,
+                gateway: default_gateway,
+            };
+            interfaces.push(interface);
 		}
         unsafe { p_adaptor = (*p_adaptor).Next; }
     }
+    return interfaces;
 }
 
 #[cfg(test)]
 mod tests {
-    use crate::os::windows;
+    use std::net::Ipv4Addr;
+    use super::*;
+    #[test]
+    fn test_nw_interfaces() {
+        let interfaces = get_interfaces();
+        for interface in interfaces {
+            println!("{:?}", interface);
+        }
+    }
     #[test]
-    fn list_nw_interfaces() {
-        windows::get_interfaces();
+    fn test_arp() {
+        let src_ip: Ipv4Addr = Ipv4Addr::new(192, 168, 1, 2);
+        let dst_ip: Ipv4Addr = Ipv4Addr::new(192, 168, 1, 1);
+        let mac_addr = get_mac_through_arp(src_ip, dst_ip);
+        println!("{}", mac_addr);
     }
 }