Support input from files and stdin

src/main.rs

@@ -1,7 +1,8 @@
 use clap::Parser;
 use std::{
     fs::File,
-    path::PathBuf,
+    io,
+    path::{Path, PathBuf},
     sync::mpsc::{channel, Sender},
     thread,
 };
@@ -23,7 +24,7 @@ struct KissPkt {
     data: Vec<u8>,
 }
 
-fn tnc_loop(tx: Sender<KissPkt>, mut stream: TcpStream) -> Result<()> {
+fn tnc_loop<T: Read>(tx: Sender<KissPkt>, mut stream: T) -> Result<()> {
     let mut buffer = [0_u8; 4096];
     let mut frame = vec![];
     let mut escaped = false;
@@ -33,6 +34,9 @@ fn tnc_loop(tx: Sender<KissPkt>, mut stream: TcpStream) -> Result<()> {
     let mut orig_len = 0;
     loop {
         let n = stream.read(&mut buffer)?;
+        if n == 0 {
+            return Ok(());
+        }
         for byte in buffer[..n].iter() {
             orig_len += 1;
             if escaped {
@@ -66,23 +70,20 @@ fn tnc_loop(tx: Sender<KissPkt>, mut stream: TcpStream) -> Result<()> {
             }
         }
     }
-    //Ok(())
 }
-const DEFAULT_ADDR: &str = "127.0.0.1:8001";
 #[derive(Parser)]
 #[command(author, version, about, long_about = None)]
 struct Arg {
     #[arg(short, long, default_value_t = false)]
     verbose: bool,
-    #[arg(short, long)]
-    file: Option<PathBuf>,
-    address: Option<String>,
+    #[arg(short, long, value_name = "FILE")]
+    output: Option<PathBuf>,
+    input: String,
 }
 
 fn main() -> Result<()> {
     let arg = Arg::parse();
-    let address = arg.address.unwrap_or(DEFAULT_ADDR.to_string());
-    let mut file = arg.file.map(|path| {
+    let mut file = arg.output.map(|path| {
         //TODO automatically add file extension
         let file_out = File::create(path).expect("Error opening file for writing");
         let header = PcapHeader {
@@ -91,15 +92,23 @@ fn main() -> Result<()> {
         };
         PcapWriter::with_header(file_out, header).expect("Error writing file")
     });
-    //println!("file: {:?}", arg.file);
-    //println!("address: {}", address);
 
     let (tx, rx) = channel();
-    let stream = TcpStream::connect(address)?;
-
-    let q = tx.clone();
-    let strm = stream.try_clone()?;
-    thread::spawn(move || tnc_loop(q, strm).unwrap());
+    match arg.input.as_str() {
+        "-" => {
+            let file = io::BufReader::new(io::stdin());
+            thread::spawn(move || tnc_loop(tx, file).unwrap());
+        }
+        s if Path::new(s).exists() => {
+            let file = io::BufReader::new(File::open(s)?);
+            thread::spawn(move || tnc_loop(tx, file).unwrap());
+        }
+        addr => {
+            let stream = TcpStream::connect(addr)?;
+            let strm = stream.try_clone()?;
+            thread::spawn(move || tnc_loop(tx, strm).unwrap());
+        }
+    }
 
     while let Ok(pkt) = rx.recv() {
         //let time = SystemTime::now();