Created
February 15, 2016 00:56
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#![allow(dead_code)] | |
use std::result; | |
use std::net::Ipv4Addr; | |
use std::fmt; | |
const BGP_MARKER: [u8; 16] = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,]; | |
#[derive(Debug)] | |
struct AutNum(u32); | |
impl fmt::Display for AutNum { | |
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
write!(f, "AS{}", self.0) | |
} | |
} | |
#[derive(Debug)] | |
struct Open<'a> { | |
inner: &'a[u8], | |
} | |
#[derive(Debug)] | |
struct OpenParams<'a> { | |
inner: &'a [u8], | |
} | |
#[derive(Debug)] | |
enum OpenParam<'a> { | |
Capability(Capability<'a>), | |
Unknown(u8) | |
} | |
#[derive(Debug)] | |
struct Capability<'a> { | |
inner: &'a [u8], | |
} | |
struct Afi(u16); | |
impl fmt::Debug for Afi { | |
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
match self.0 { | |
1 => write!(f, "ipv4"), | |
2 => write!(f, "ipv6"), | |
n => write!(f, "unknown({})", n), | |
} | |
} | |
} | |
struct Safi(u8); | |
impl fmt::Debug for Safi { | |
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
match self.0 { | |
1 => write!(f, "unicast"), | |
2 => write!(f, "multicast"), | |
n => write!(f, "unknown({})", n), | |
} | |
} | |
} | |
struct AddPathDirection(u8); | |
impl fmt::Debug for AddPathDirection { | |
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
match self.0 { | |
1 => write!(f, "receive"), | |
2 => write!(f, "send"), | |
3 => write!(f, "both"), | |
n => write!(f, "unknown({})", n), | |
} | |
} | |
} | |
#[derive(Debug)] | |
enum CapabilityType { | |
Reserved, | |
MultiProtocol(Afi, Safi), | |
RouteRefresh, | |
Orf, | |
MultipleRoutes, | |
ExtendedNextHopEncoding, | |
GracefulRestart, | |
FourByteASN, | |
DynamicCapability, | |
MultiSession, | |
AddPath(Afi, Safi, AddPathDirection), | |
EnhancedRouteRefresh, | |
Private(u8), | |
Other(u8), | |
} | |
impl<'a> Capability<'a> { | |
fn capability_type(&self) -> CapabilityType { | |
match self.inner[0] { | |
0 => CapabilityType::Reserved, | |
1 => CapabilityType::MultiProtocol(Afi((self.inner[2] as u16) << 8 | (self.inner[3] as u16)), Safi(self.inner[5])), | |
2 => CapabilityType::RouteRefresh, | |
3 => CapabilityType::Orf, | |
4 => CapabilityType::MultipleRoutes, | |
5 => CapabilityType::ExtendedNextHopEncoding, | |
64 => CapabilityType::GracefulRestart, | |
65 => CapabilityType::FourByteASN, | |
67 => CapabilityType::DynamicCapability, | |
68 => CapabilityType::MultiSession, | |
69 => CapabilityType::AddPath(Afi((self.inner[2] as u16) << 8 | (self.inner[3] as u16)), Safi(self.inner[4]), AddPathDirection(self.inner[5])), | |
70 => CapabilityType::EnhancedRouteRefresh, | |
n @ 128...255 => CapabilityType::Private(n), | |
n => CapabilityType::Other(n), | |
} | |
} | |
} | |
#[derive(Debug)] | |
enum BgpError { | |
BadLength, | |
Invalid | |
} | |
impl<'a> Iterator for OpenParams<'a> { | |
type Item = OpenParam<'a>; | |
fn next(&mut self) -> Option<OpenParam<'a>> { | |
if self.inner.len() == 0 { | |
return None; | |
} | |
let param_type = self.inner[0]; | |
let param_len = self.inner[1] as usize; | |
let param_value = &self.inner[2..param_len+2]; | |
self.inner = &self.inner[param_len+2..]; | |
match param_type { | |
2 => Some(OpenParam::Capability(Capability{ inner: param_value })), | |
n => Some(OpenParam::Unknown(n)), | |
} | |
} | |
} | |
type Result<T> = result::Result<T,BgpError>; | |
impl<'a> Open<'a> { | |
fn new(raw: &'a [u8]) -> Result<Open> { | |
if raw.len() < 10 { | |
return Err(BgpError::BadLength); | |
} else { | |
Ok(Open { inner: raw }) | |
} | |
} | |
fn version(&self) -> u8 { | |
self.inner[0] | |
} | |
fn aut_num(&self) -> AutNum { | |
AutNum((self.inner[1] as u32) << 8 | self.inner[2] as u32) | |
} | |
fn hold_time(&self) -> u16 { | |
(self.inner[3] as u16) << 8 | self.inner[4] as u16 | |
} | |
fn ident(&self) -> Ipv4Addr { | |
Ipv4Addr::from((self.inner[5] as u32) << 24 | |
| (self.inner[6] as u32) << 16 | |
| (self.inner[7] as u32) << 8 | |
| (self.inner[8] as u32)) | |
} | |
fn params(&self) -> OpenParams { | |
OpenParams{ inner: &self.inner[10..] } | |
} | |
} | |
#[derive(Debug)] | |
enum Message<'a> { | |
Open(Open<'a>), | |
Update, | |
Notification, | |
KeepAlive, | |
Refresh, | |
} | |
impl<'a> Message<'a> { | |
fn from_bytes(raw: &'a [u8]) -> Result<Message> { | |
if raw.len() < 19 || raw.len() > 4096 { | |
return Err(BgpError::BadLength); | |
} | |
let (marker, message) = raw.split_at(16); | |
if marker != BGP_MARKER { | |
return Err(BgpError::Invalid); | |
} | |
let (length, msg_type) = message[..3].split_at(2); | |
let length = (length[0] as u16) << 8 | (length[1] as u16); | |
if length as usize != raw.len() { | |
return Err(BgpError::Invalid); | |
} | |
match msg_type[0] { | |
1 => Ok(Message::Open(try!(Open::new(&message[3..])))), | |
2 => Ok(Message::Update), | |
3 => Ok(Message::Notification), | |
4 => Ok(Message::KeepAlive), | |
5 => Ok(Message::Refresh), | |
_ => Err(BgpError::Invalid), | |
} | |
} | |
} | |
fn main () { | |
let bytes = &[0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, | |
0x00, 0x41, 0x01, 0x04, 0xfc, 0x00, 0x00, 0xb4, 0x0a, 0x00, 0x00, 0x06, 0x24, 0x02, 0x06, 0x01, | |
0x04, 0x00, 0x01, 0x00, 0x01, 0x02, 0x02, 0x80, 0x00, 0x02, 0x02, 0x02, 0x00, 0x02, 0x02, 0x46, | |
0x00, 0x02, 0x06, 0x45, 0x04, 0x00, 0x01, 0x01, 0x03, 0x02, 0x06, 0x41, 0x04, 0x00, 0x00, 0xfc, 0x00]; | |
let msg = Message::from_bytes(bytes); | |
match msg { | |
Ok(Message::Open(open)) => { | |
println!("version: {}", open.version()); | |
println!("aut_num: {}", open.aut_num()); | |
println!("hold_time: {}", open.hold_time()); | |
println!("ident: {}", open.ident()); | |
println!("params:"); | |
//println!("{:#?}", open.params().collect::<Vec<OpenParam>>()); | |
for param in open.params() { | |
match param { | |
OpenParam::Capability(cap) => println!("\t{:?}", cap.capability_type()), | |
_ => println!("\t{:?}", param), | |
} | |
} | |
} | |
_ => (), | |
} | |
} |
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