Factor out termios and the line discipline into their own crates

Cargo.lock

@@ -68,6 +68,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "either"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
+
 [[package]]
 name = "embedded-io"
 version = "0.4.0"
@@ -113,12 +119,28 @@ dependencies = [
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
 
+[[package]]
+name = "line_discipline"
+version = "0.1.0"
+dependencies = [
+ "itertools",
+]
+
 [[package]]
 name = "lock_api"
 version = "0.4.12"
@@ -193,6 +215,7 @@ dependencies = [
  "dev_driver_rpc",
  "devfs_rpc",
  "file_rpc",
+ "line_discipline",
  "parking_lot",
  "slab",
  "syslog_rpc",

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 dev_driver_rpc = { version = "0.1.0", path = "../dev_driver_rpc" }
 devfs_rpc = { version = "0.1.0", path = "../devfs/devfs_rpc" }
 file_rpc = { version = "0.1.0", path = "../file_rpc" }
+line_discipline = { version = "0.1.0", path = "../line_discipline" }
 parking_lot = "0.12.3"
 slab = "0.4.9"
 syslog_rpc = { version = "0.1.0", path = "../syslog/syslog_rpc" }

src/main.rs

@@ -1,23 +1,20 @@
-mod termios;
-
 use std::{
-    borrow::Cow, collections::HashMap, io::empty, os::mikros::{ipc, syscalls}, path::{Path, PathBuf}, sync::{
-        atomic::{AtomicBool, AtomicUsize, Ordering},
-        Arc,
-    }
+    borrow::Cow,
+    collections::HashMap,
+    os::mikros::{ipc, syscalls},
+    path::{Path, PathBuf},
+    sync::Arc,
 };
 
 use file_rpc::PollEvents;
+use line_discipline::LineDiscipline;
 use parking_lot::{Mutex, RwLock};
 use slab::Slab;
-use termios::Termios;
 
 struct Pty {
     input_buffer: Mutex<Vec<u8>>,
     output_buffer: Mutex<Vec<u8>>,
-    termios: Termios,
-    output_paused: AtomicBool,
-    column: AtomicUsize,
+    line_discipline: Mutex<LineDiscipline>,
 }
 
 impl Pty {
@@ -25,169 +22,48 @@ impl Pty {
         Pty {
             input_buffer: Mutex::new(Vec::new()),
             output_buffer: Mutex::new(Vec::new()),
-            termios: Termios::default(),
-            output_paused: AtomicBool::new(false),
-            column: AtomicUsize::new(0),
+            line_discipline: Mutex::new(LineDiscipline::new()),
         }
     }
 
-    fn read_master(&self, len: usize) -> Result<Vec<u8>, ()> {
-        if self.output_paused.load(Ordering::Relaxed) {
-            return Ok(vec![]);
+    fn read_master(&self, len: usize) -> Vec<u8> {
+        if self.line_discipline.lock().output_paused() {
+            return Vec::new();
         }
         let mut output_buffer = self.output_buffer.lock();
+        output_buffer.extend_from_slice(&self.line_discipline.lock().get_terminal_output());
         let buf_len = output_buffer.len();
         let rem_buf = output_buffer.split_off(usize::min(buf_len, len));
-        let buf = std::mem::replace(&mut *output_buffer, rem_buf);
-        Ok(buf)
+        std::mem::replace(&mut *output_buffer, rem_buf)
     }
 
-    fn write_master(&self, data: &[u8]) -> Result<(), ()> {
-        if !self.termios.cflags.cread {
-            return Ok(());
-        }
-        for &(mut ch) in data {
-            if self.termios.iflags.istrip {
-                ch &= 0x7F;
-            }
-            if ch == b'\r' && self.termios.iflags.igncr {
-                continue;
-            } else if ch == b'\r' && self.termios.iflags.icrnl {
-                ch = b'\n';
-            } else if ch == b'\n' && self.termios.iflags.inlcr {
-                ch = b'\r';
-            }
-            if ch as char == self.termios.verase && self.termios.lflags.icanon {
-                let buf_last = self.input_buffer.lock().last().copied();
-                if let Some(erased_ch) = buf_last {
-                    let erased_ch = erased_ch as char;
-                    if erased_ch != '\n' {
-                        self.input_buffer.lock().pop();
-                        self.erase_char(erased_ch);
-                    }
-                }
-            } else if ch as char == self.termios.vkill && self.termios.lflags.icanon {
-                let buf_last = self.input_buffer.lock().last().copied();
-                if let Some(erased_ch) = buf_last {
-                    let erased_ch = erased_ch as char;
-                    if erased_ch != '\n' {
-                        self.input_buffer.lock().pop();
-                        self.erase_char(erased_ch);
-                    }
-                }
-            } else if ch as char == self.termios.vstop && self.termios.iflags.ixon {
-                self.output_paused.store(true, Ordering::Relaxed);
-            } else if (ch as char == self.termios.vstart && self.termios.iflags.ixon)
-                || (self.termios.iflags.ixany && self.output_paused.load(Ordering::Relaxed))
-            {
-                self.output_paused.store(false, Ordering::Relaxed);
-            } else {
-                self.input_buffer.lock().push(ch);
-                if self.termios.lflags.echo || (ch == b'\n' && self.termios.lflags.echonl) {
-                    let mut output_buffer = self.output_buffer.lock();
-                    if Self::is_nonprinting_control(ch as char) {
-                        output_buffer.push(b'^');
-                        output_buffer.push(ch + b'@');
-                        self.column.fetch_add(2, Ordering::Relaxed);
-                    } else if ch == b'\t' {
-                        let curr_col = self.column.load(Ordering::Relaxed);
-                        let num_cols = 8 - (curr_col % 8);
-                        for _ in 0..num_cols {
-                            output_buffer.push(b' ');
-                        }
-                        self.column.fetch_add(num_cols, Ordering::Relaxed);
-                    } else {
-                        output_buffer.push(ch);
-                        self.column.fetch_add(1, Ordering::Relaxed);
-                    }
-                }
-            }
-        }
-        Ok(())
+    fn write_master(&self, data: &[u8]) {
+        self.line_discipline.lock().process_terminal_input(data);
     }
 
-    fn read_slave(&self, len: usize) -> Result<Vec<u8>, ()> {
+    fn read_slave(&self, len: usize) -> Vec<u8> {
         while !self.input_buffer.lock().contains(&b'\n') {
             ipc::process_messages();
+            let mut input_buffer = self.input_buffer.lock();
+            input_buffer.extend_from_slice(&self.line_discipline.lock().get_program_input());
         }
         let mut input_buffer = self.input_buffer.lock();
+        input_buffer.extend_from_slice(&self.line_discipline.lock().get_program_input());
         let Some(line_end) = input_buffer.iter().position(|&x| x == b'\n') else {
-            return Ok(vec![]);
+            return Vec::new();
         };
         let rem_buf = input_buffer.split_off(usize::min(len, line_end + 1));
-        let buf = std::mem::replace(&mut *input_buffer, rem_buf);
-        Ok(buf)
+        std::mem::replace(&mut *input_buffer, rem_buf)
     }
 
-    fn write_slave(&self, data: &[u8]) -> Result<(), ()> {
-        let mut output_buffer = self.output_buffer.lock();
-        for &byte in data {
-            if self.termios.oflags.opost {
-                if byte == b'\n' && self.termios.oflags.onlcr {
-                    if self.column.load(Ordering::Relaxed) != 0 {
-                        output_buffer.push(b'\r');
-                    }
-                    output_buffer.push(b'\n');
-                    self.column.store(0, Ordering::Relaxed);
-                } else if byte == b'\r' && self.termios.oflags.ocrnl {
-                    output_buffer.push(b'\n');
-                    if self.termios.oflags.onlret {
-                        self.column.store(0, Ordering::Relaxed);
-                    }
-                } else {
-                    output_buffer.push(byte);
-                }
-            } else if (byte == b'\n' && self.termios.oflags.onlret) || byte == b'\r' {
-                self.column.store(0, Ordering::Relaxed);
-            }
-        }
-        Ok(())
-    }
-
-    fn is_nonprinting_control(ch: char) -> bool {
-        ch.is_ascii_control() && ch != '\r' && ch != '\n' && ch != '\t'
-    }
-
-    fn erase_char(&self, ch: char) {
-        if !self.termios.lflags.echoe {
-            return;
-        }
-        let mut output_buffer = self.output_buffer.lock();
-        if Self::is_nonprinting_control(ch) {
-            output_buffer.push(8);
-            output_buffer.push(8);
-            self.column.fetch_sub(2, Ordering::Relaxed);
-        } else if ch == '\t' {
-            let curr_col = self.column.load(Ordering::Relaxed);
-            let mut before_tab_cols = 0;
-            let mut after_tab = false;
-            let input_buffer = self.input_buffer.lock();
-            for &byte in input_buffer.iter().rev() {
-                if Self::is_nonprinting_control(byte as char) {
-                    before_tab_cols += 2;
-                } else if byte == b'\t' {
-                    after_tab = true;
-                    break;
-                } else {
-                    before_tab_cols += 1;
-                }
-            }
-            let num_cols = if after_tab {
-                8 - before_tab_cols
-            } else {
-                curr_col - before_tab_cols
-            };
-            for _ in 0..num_cols {
-                output_buffer.push(8);
-            }
-            self.column.fetch_sub(num_cols, Ordering::Relaxed);
-        } else {
-            output_buffer.push(8);
-            self.column.fetch_sub(1, Ordering::Relaxed);
-        }
+    fn write_slave(&self, data: &[u8]) {
+        self.line_discipline.lock().process_program_output(data);
     }
 
     fn curr_slave_poll(&self) -> PollEvents {
+        self.input_buffer
+            .lock()
+            .extend_from_slice(&self.line_discipline.lock().get_program_input());
         let mut events = PollEvents::POLLOUT;
         if self.input_buffer.lock().contains(&b'\n') {
             events |= PollEvents::POLLIN;
@@ -196,6 +72,9 @@ impl Pty {
     }
 
     fn curr_master_poll(&self) -> PollEvents {
+        self.output_buffer
+            .lock()
+            .extend_from_slice(&self.line_discipline.lock().get_terminal_output());
         let mut events = PollEvents::POLLOUT;
         if !self.output_buffer.lock().is_empty() {
             events |= PollEvents::POLLIN;
@@ -239,11 +118,11 @@ impl file_rpc::Server for Serv {
         if fd as usize >= usize::MAX / 2 {
             let ptys = self.ptys.read();
             let pty = &ptys[fd as usize - usize::MAX / 2];
-            pty.read_slave(len).map(|x| x.into())
+            Ok(pty.read_slave(len).into())
         } else {
             let ptys = self.ptys.read();
             let pty = &ptys[fd as usize];
-            pty.read_master(len).map(|x| x.into())
+            Ok(pty.read_master(len).into())
         }
     }
 
@@ -251,11 +130,13 @@ impl file_rpc::Server for Serv {
         if fd as usize >= usize::MAX / 2 {
             let ptys = self.ptys.read();
             let pty = &ptys[fd as usize - usize::MAX / 2];
-            pty.write_slave(data)
+            pty.write_slave(data);
+            Ok(())
         } else {
             let ptys = self.ptys.read();
             let pty = &ptys[fd as usize];
-            pty.write_master(data)
+            pty.write_master(data);
+            Ok(())
         }
     }
 
@@ -282,7 +163,7 @@ impl file_rpc::Server for Serv {
         let pty_no = if fd as usize >= usize::MAX / 2 {
             fd as usize - usize::MAX / 2
         } else {
-           fd as usize
+            fd as usize
         };
         let slave = fd as usize >= usize::MAX / 2;
         loop {
@@ -290,9 +171,9 @@ impl file_rpc::Server for Serv {
                 return None;
             }
             let curr_poll = if slave {
-                 self.ptys.read()[pty_no].curr_slave_poll()
+                self.ptys.read()[pty_no].curr_slave_poll()
             } else {
-                 self.ptys.read()[pty_no].curr_master_poll()
+                self.ptys.read()[pty_no].curr_master_poll()
             };
             if !((curr_poll & req_events).is_empty()) {
                 self.polls.lock().remove(poll_id);

src/termios.rs

@@ -1,212 +0,0 @@
-#[allow(unused)]
-pub struct Iflags {
-    pub brkint: bool,
-    pub icrnl: bool,
-    pub ignbrk: bool,
-    pub igncr: bool,
-    pub ignpar: bool,
-    pub inlcr: bool,
-    pub inpck: bool,
-    pub istrip: bool,
-    pub ixany: bool,
-    pub ixoff: bool,
-    pub ixon: bool,
-    pub parmark: bool,
-}
-
-impl Default for Iflags {
-    fn default() -> Self {
-        Self {
-            brkint: false,
-            icrnl: true,
-            ignbrk: false,
-            igncr: false,
-            ignpar: true,
-            inlcr: false,
-            inpck: true,
-            istrip: false,
-            ixany: false,
-            ixoff: false,
-            ixon: true,
-            parmark: false,
-        }
-    }
-}
-
-#[allow(unused)]
-pub struct Oflags {
-    pub opost: bool,
-    pub onlcr: bool,
-    pub ocrnl: bool,
-    pub onocr: bool,
-    pub onlret: bool,
-    pub ofdel: bool,
-    pub nldly: NlDelay,
-    pub crdly: CrDelay,
-    pub tabdly: TabDelay,
-    pub bsdly: BsDelay,
-    pub vtdly: VtDelay,
-    pub ffdly: FfDelay,
-}
-
-impl Default for Oflags {
-    fn default() -> Self {
-        Self {
-            opost: true,
-            onlcr: true,
-            ocrnl: false,
-            onocr: false,
-            onlret: false,
-            ofdel: false,
-            nldly: NlDelay::Nl0,
-            crdly: CrDelay::Cr0,
-            tabdly: TabDelay::Tab0,
-            bsdly: BsDelay::Bs0,
-            vtdly: VtDelay::Vt0,
-            ffdly: FfDelay::Ff0,
-        }
-    }
-}
-
-#[allow(unused)]
-pub enum NlDelay {
-    Nl0,
-    Nl1,
-}
-
-#[allow(unused)]
-pub enum CrDelay {
-    Cr0,
-    Cr1,
-    Cr2,
-    Cr3,
-}
-
-#[allow(unused)]
-pub enum TabDelay {
-    Tab0,
-    Tab1,
-    Tab2,
-    Tab3,
-}
-
-#[allow(unused)]
-pub enum BsDelay {
-    Bs0,
-    Bs1,
-}
-
-#[allow(unused)]
-pub enum VtDelay {
-    Vt0,
-    Vt1,
-}
-
-#[allow(unused)]
-pub enum FfDelay {
-    Ff0,
-    Ff1,
-}
-
-#[allow(unused)]
-pub struct Cflags {
-    pub csize: CharSize,
-    pub cstopb: bool,
-    pub cread: bool,
-    pub parenb: bool,
-    pub parodd: bool,
-    pub hupcl: bool,
-    pub clocal: bool,
-}
-
-impl Default for Cflags {
-    fn default() -> Self {
-        Self {
-            csize: CharSize::Cs8,
-            cstopb: false,
-            cread: true,
-            parenb: false,
-            parodd: false,
-            hupcl: true,
-            clocal: false,
-        }
-    }
-}
-
-#[allow(unused)]
-pub enum CharSize {
-    Cs5,
-    Cs6,
-    Cs7,
-    Cs8,
-}
-
-#[allow(unused)]
-pub struct Lflags {
-    pub echo: bool,
-    pub echoe: bool,
-    pub echok: bool,
-    pub echonl: bool,
-    pub icanon: bool,
-    pub iexten: bool,
-    pub isig: bool,
-    pub noflsh: bool,
-    pub tostop: bool,
-}
-
-impl Default for Lflags {
-    fn default() -> Self {
-        Self {
-            echo: true,
-            echoe: true,
-            echok: true,
-            echonl: false,
-            icanon: true,
-            iexten: true,
-            isig: true,
-            noflsh: false,
-            tostop: false,
-        }
-    }
-}
-
-#[allow(unused)]
-pub struct Termios {
-    pub iflags: Iflags,
-    pub oflags: Oflags,
-    pub cflags: Cflags,
-    pub lflags: Lflags,
-    pub veof: char,
-    pub veol: char,
-    pub verase: char,
-    pub vintr: char,
-    pub vkill: char,
-    pub vmin: u32,
-    pub vquit: char,
-    pub vstart: char,
-    pub vstop: char,
-    pub vsusp: char,
-    pub vtime: u32,
-}
-
-impl Default for Termios {
-    fn default() -> Self {
-        Self {
-            iflags: Iflags::default(),
-            oflags: Oflags::default(),
-            cflags: Cflags::default(),
-            lflags: Lflags::default(),
-            veof: '\u{4}', //ctrl-D (EOT)
-            veol: '\n',
-            verase: '\u{8}', //ctrl-H (BS)
-            vintr: '\u{3}',  //ctrl-C (ETX)
-            vkill: '\u{15}', //ctrl-U (NAK)
-            vmin: 0,
-            vquit: '\u{1C}',  //ctrl-\
-            vstart: '\u{11}', // ctrl-S (XONN)
-            vstop: '\u{13}',  // ctrl-Q (XOFF)
-            vsusp: '\u{1A}',  // ctrl-Z (SUB)
-            vtime: 0,
-        }
-    }
-}