mirror of https://github.com/dswd/vpncloud.git
54 lines
1.8 KiB
Rust
54 lines
1.8 KiB
Rust
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use std::net::SocketAddr;
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use std::collections::{hash_map, HashMap};
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struct RoutingEntry {
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address: SocketAddr,
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bytes: Vec<u8>,
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prefix_len: u8
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}
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pub struct RoutingTable(HashMap<Vec<u8>, Vec<RoutingEntry>>);
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impl RoutingTable {
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pub fn new() -> Self {
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RoutingTable(HashMap::new())
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}
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pub fn add(&mut self, bytes: Vec<u8>, prefix_len: u8, address: SocketAddr) {
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let group_len = (prefix_len as usize / 16) * 2;
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let group_bytes: Vec<u8> = bytes[..group_len].iter().map(|b| *b).collect();
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let routing_entry = RoutingEntry{address: address, bytes: bytes, prefix_len: prefix_len};
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match self.0.entry(group_bytes) {
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hash_map::Entry::Occupied(mut entry) => entry.get_mut().push(routing_entry),
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hash_map::Entry::Vacant(entry) => { entry.insert(vec![routing_entry]); () }
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}
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}
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pub fn lookup(&self, bytes: Vec<u8>) -> Option<SocketAddr> {
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let mut len = bytes.len()/2 * 2;
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for i in 0..len/2 {
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if let Some(group) = self.0.get(&bytes[0..len-2*i]) {
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for entry in group {
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if entry.bytes.len() != bytes.len() {
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continue;
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}
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let mut match_len = 0;
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for i in 0..bytes.len() {
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let b = bytes[i] ^ entry.bytes[i];
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if b == 0 {
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match_len += 8;
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} else {
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match_len += b.leading_zeros();
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break;
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}
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}
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if match_len as u8 >= entry.prefix_len {
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return Some(entry.address);
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}
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}
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}
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}
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None
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}
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}
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