Merge pull request 'basic headers-parsing logic' (#1) from headers-parsing into main

Reviewed-on: https://codeberg.org/NamelessTeam/nsc/pulls/1

3 files changed, 98 insertions, 10 deletions

diff --git a/src/main.rs b/src/main.rs
index 958e39d..464146a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,12 +1,13 @@
 mod config;
 mod geoparsers;
-mod sniffing;
+pub mod sniffing;
 mod startup;
 
 use startup::init;
 
 use std::io::Read;
 
-fn main() {
-    init();
+fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>
+>{
+    init()
 }
diff --git a/src/sniffing/headers.rs b/src/sniffing/headers.rs
index 7ed1a88..c90a849 100644
--- a/src/sniffing/headers.rs
+++ b/src/sniffing/headers.rs
@@ -1,9 +1,92 @@
+use tun::Error;
+
 // Here we will recieve bytes and try to get their destanation & apply Rules for them.
 use crate::config::Config;
 
-struct PacketInfo;
+#[derive(Debug)]
+pub enum Protocol {
+    TCP,
+    UDP,
+    Unsupported(u8)
+}
+type Ipv4 = [u8; 4];
+type Ipv6 = [u8; 16];
+type Port = u16;
+#[derive(Debug)]
+pub enum PacketInfo {
+    // <https://www.geeksforgeeks.org/computer-networks/what-is-ipv4/>
+    V4 {
+        src_ip: Ipv4,
+        src_port: Port,
+        dst_ip: Ipv4,
+        dst_port: Port,
+        protocol: Protocol
+    },
+    // <https://www.geeksforgeeks.org/computer-networks/internet-protocol-version-6-ipv6-header/>
+    V6 {
+        src_ip: Ipv6,
+        src_port: Port,
+        dst_ip: Ipv6,
+        dst_port: Port,
+        protocol: Protocol
+    }
+}
+
+impl PacketInfo {
+    pub fn protocol(&self) -> &Protocol {
+        match self {
+            PacketInfo::V4 { protocol, .. } => protocol,
+            PacketInfo::V6 { protocol, .. } => protocol,
+        }
+    }
+}
 pub fn sniff_raw_packets(packet: &[u8]) -> Result<PacketInfo, Box<dyn std::error::Error + Send + Sync + 'static>> {
-    todo!()
+    let ver = packet[0] >> 4;
+    dbg!(ver);
+    match ver {
+        4 => {
+            let v4 = PacketInfo::V4{
+                src_ip: <[u8; 4]>::try_from(&packet[12..16])?,
+                src_port: u16::from_be_bytes([packet[20], packet[21]]),
+                dst_ip: <[u8; 4]>::try_from(&packet[16..20])?,
+                dst_port: u16::from_be_bytes([packet[22], packet[23]]),
+                protocol: match packet[9] {
+                    6 => Protocol::TCP,
+                    17 => Protocol::UDP,
+                    p => Protocol::Unsupported(p)
+                }
+            };
+        if !matches!(v4.protocol(), Protocol::Unsupported(_)) {
+            println!("{v4:?}");
+        } else {
+            println!("oppsie unsupported");
+            }
+            Ok(v4)
+        },
+        6 => {
+    println!("im in 6!");
+            let v6 = PacketInfo::V6{
+                src_ip: <[u8; 16]>::try_from(&packet[8..24])?,
+                src_port: u16::from_be_bytes([packet[40], packet[41]]),
+                dst_ip: <[u8; 16]>::try_from(&packet[24..40])?,
+                dst_port: u16::from_be_bytes([packet[42], packet[43]]),
+                protocol: match packet[6] {
+                    6 => Protocol::TCP,
+                    4 => Protocol::UDP,
+                    p => Protocol::Unsupported(p)
+                }
+            };
+        if !matches!(v6.protocol(), Protocol::Unsupported(_)) {
+            println!("{v6:?}");
+        } else {
+            println!("oppsie unsupported");
+            }
+            Ok(v6)
+        },
+        ver => {
+            Err(format!("unsuppiorted ver: {ver}").into())
+        }
+    }
 }
 
 pub fn apply_rules(config: Config, pinfo: PacketInfo) {
diff --git a/src/startup.rs b/src/startup.rs
index b9e0191..10a8441 100644
--- a/src/startup.rs
+++ b/src/startup.rs
@@ -1,7 +1,7 @@
 // Here we iniitialize systems crucial for nsc
 use std::io::Read;
-use sniffing::headers::sniff_raw_packets;
-
+use crate::sniffing::headers::sniff_raw_packets;
+use crate::sniffing::headers::Protocol;
 pub fn init() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
     let mut config = tun::Configuration::default();
     config
@@ -21,8 +21,12 @@ pub fn init() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>>
 
     loop {
         let amount = dev.read(&mut buf)?;
-        sniff_raw_packets(&buf[0..amount]);
-        dbg!("{:?}", &buf[0..amount]);
-
+        // dbg!(sniff_raw_packets(&buf[0..amount])?);
+        let govno = sniff_raw_packets(&buf[0..amount])?;
+        if !matches!(govno.protocol(), Protocol::Unsupported(_)) {
+            // println!("1")
+            // println!("{:?}", govno)
+        }
+        // dbg!("{:?}", &buf[0..amount]);
     }
 }