Revert "implement (bidirectional) mss clamping"

This reverts commit dc8b17410cec050ea62f65056b455644e5253126.

4 files changed, 3 insertions, 83 deletions

diff --git a/Cargo.lock b/Cargo.lock
index e27dea2..4f78eb2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -27,12 +27,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7de8ce5e0f9f8d88245311066a578d72b7af3e7088f32783804676302df237e4"
 
 [[package]]
-name = "arrayvec"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8da52d66c7071e2e3fa2a1e5c6d088fec47b593032b254f5e980de8ea54454d6"
-
-[[package]]
 name = "atty"
 version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -244,15 +238,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "etherparse"
-version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "827292ea592108849932ad8e30218f8b1f21c0dfd0696698a18b5d0aed62d990"
-dependencies = [
- "arrayvec",
-]
-
-[[package]]
 name = "filetime"
 version = "0.2.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -940,10 +925,9 @@ dependencies = [
 
 [[package]]
 name = "rsdsl_pppoe"
-version = "0.1.2"
+version = "0.1.1"
 dependencies = [
  "byteorder",
- "etherparse",
  "md5",
  "pppoe",
  "rand",
diff --git a/Cargo.toml b/Cargo.toml
index 341d8e4..0d3ade2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rsdsl_pppoe"
-version = "0.1.2"
+version = "0.1.1"
 authors = ["HimbeerserverDE <himbeerserverde@gmail.com>"]
 license = "MIT"
 edition = "2021"
@@ -9,7 +9,6 @@ edition = "2021"
 
 [dependencies]
 byteorder = "1.4.3"
-etherparse = "0.13.0"
 md5 = "0.7.0"
 pppoe = { git = "https://github.com/rsdsl/pppoe-rs.git", version = "0.1.0", features = ["socket"] }
 rand = "0.8.5"
diff --git a/src/error.rs b/src/error.rs
index d35730b..1411f3a 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -65,12 +65,6 @@ pub enum Error {
     Pppoe(pppoe::error::Error),
     #[error("pppoe parse error: {0:?}")]
     PppoeParse(pppoe::error::ParseError),
-    #[error("etherparse read error: {0}")]
-    EtherParseRead(#[from] etherparse::ReadError),
-    #[error("etherparse tcp option write error: {0}")]
-    EtherParseTcpOptionWrite(#[from] etherparse::TcpOptionWriteError),
-    #[error("etherparse value error: {0}")]
-    EtherParseValue(#[from] etherparse::ValueError),
     #[error("rsdsl_netlinkd error")]
     RsdslNetlinkd(#[from] rsdsl_netlinkd::error::Error),
     #[error("serde_json error")]
diff --git a/src/main.rs b/src/main.rs
index 1be7d5f..5a7f047 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,14 +8,11 @@ use std::sync::{Arc, Mutex};
 use std::thread;
 
 use byteorder::{ByteOrder, NetworkEndian as NE};
-use etherparse::{Ipv4Header, TcpHeader, TcpOptionElement};
 use pppoe::packet::IPV4;
 use rsdsl_ip_config::IpConfig;
 use rsdsl_netlinkd::link;
 use tun_tap::{Iface, Mode};
 
-const IPPROTO_TCP: u8 = 0x06;
-
 fn prepend<T>(v: Vec<T>, s: &[T]) -> Vec<T>
 where
     T: Clone,
@@ -25,50 +22,6 @@ where
     tmp
 }
 
-fn clamp_mss_if_needed(buf: &mut [u8]) -> Result<()> {
-    let ipv4_header = Ipv4Header::from_slice(&buf[4..])?.0;
-
-    if ipv4_header.protocol == IPPROTO_TCP {
-        let ipv4_header_bytes = ipv4_header.ihl() as usize * 4;
-
-        let mut tcp_header = TcpHeader::from_slice(&buf[4 + ipv4_header_bytes..])?.0;
-
-        if tcp_header.syn {
-            let tcp_header_bytes = tcp_header.header_len() as usize;
-
-            let mut opts = Vec::new();
-            for opt in tcp_header.options_iterator() {
-                match opt {
-                    Ok(mut opt) => {
-                        if let TcpOptionElement::MaximumSegmentSize(_) = opt {
-                            opt = TcpOptionElement::MaximumSegmentSize(1492);
-                        }
-
-                        opts.push(opt);
-                    }
-                    Err(e) => println!("[pppoe] ignore invalid tcp opt: {}", e),
-                }
-            }
-
-            tcp_header.set_options(&opts)?;
-            tcp_header.checksum = tcp_header.calc_checksum_ipv4(
-                &ipv4_header,
-                &buf[4 + ipv4_header_bytes + tcp_header_bytes..],
-            )?;
-
-            let tcp_header_bytes = tcp_header.header_len() as usize;
-
-            let mut hdr = Vec::new();
-            tcp_header.write(&mut hdr)?;
-
-            buf[4 + ipv4_header_bytes..4 + ipv4_header_bytes + tcp_header_bytes]
-                .copy_from_slice(&hdr);
-        }
-    }
-
-    Ok(())
-}
-
 fn tun2ppp(tx: mpsc::Sender<Option<Vec<u8>>>, tun: Arc<Iface>) -> Result<()> {
     loop {
         let mut buf = [0; 4 + 1492];
@@ -79,7 +32,7 @@ fn tun2ppp(tx: mpsc::Sender<Option<Vec<u8>>>, tun: Arc<Iface>) -> Result<()> {
                 continue;
             }
         };
-        let buf = &mut buf[..n];
+        let buf = &buf[..n];
 
         let ether_type = NE::read_u16(&buf[2..4]);
         if ether_type != IPV4 {
@@ -90,11 +43,6 @@ fn tun2ppp(tx: mpsc::Sender<Option<Vec<u8>>>, tun: Arc<Iface>) -> Result<()> {
             continue;
         }
 
-        match clamp_mss_if_needed(buf) {
-            Ok(_) => {}
-            Err(e) => println!("[pppoe] ignore outbound mss clamping error: {}", e),
-        }
-
         tx.send(Some(buf[4..].to_vec()))?;
     }
 }
@@ -106,11 +54,6 @@ fn ppp2tun(rx: Arc<Mutex<mpsc::Receiver<Vec<u8>>>>, tun: Arc<Iface>) -> Result<(
     NE::write_u16(&mut packet_info[2..4], IPV4);
 
     while let Ok(mut buf) = rx.recv() {
-        match clamp_mss_if_needed(&mut buf) {
-            Ok(_) => {}
-            Err(e) => println!("[pppoe] ignore inbound mss clamping error: {}", e),
-        }
-
         buf = prepend(buf, &packet_info);
 
         let n = match tun.send(&buf) {