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//! IngressManager
//!
//! All communicated date is run through here, parsed, then executed.
use crate::ingress::buffer::{Buffer, Type};
use crate::system::syscall::Syscall;
use crate::system::System;
use core::str::FromStr;
use heapless::consts::*;
use heapless::spsc::Queue;
use simple_hex::hex_byte_to_byte;
use log::info;
#[derive(Copy, Clone, PartialEq, Debug)]
enum State {
/// Waiting for a STX byte, or just received an ETX, or entered an invalid state
Wait,
/// Init state, just after receiving and STX
Init,
/// Write into an internal buffer for parsing
Payload,
/// Parse the application checksum
ApplicationChecksum,
/// Store the application in ram
ApplicationStore,
/// Notification Source - what generated the push notification
NotificationSource,
/// Notification title
NotificationTitle,
/// Notification body
NotificationBody,
}
const STX: u8 = 2;
const ETX: u8 = 3;
const PAYLOAD: u8 = 31; // Unit Separator
pub struct IngressManager {
rb: Queue<u8, U512>,
state: State,
hex_chars: [u8; 2],
hex_idx: usize,
nsi: [usize; 3],
nsi_idx: usize,
buffer: Buffer,
}
impl IngressManager {
/// Constructs a new IngressManager
pub fn new() -> Self {
IngressManager {
rb: Queue::new(),
state: State::Init,
hex_chars: [0u8; 2],
hex_idx: 0,
nsi: [0usize; 3], // notification section pointers
nsi_idx: 0,
buffer: Buffer::default(),
}
}
/// Write data into the internal ring buffer
/// raw bytes being the core type allows the ingress manager to
/// be abstracted over the communication medium,
/// in theory if we setup usb serial, we could have two ingress managers
/// working in harmony
pub fn write(&mut self, data: &[u8]) {
for byte in data {
match self.rb.enqueue(*byte) {
Ok(_) => {}
Err(e) => panic!("Ring buffer overflow by {:?} bytes", e),
}
}
}
/// Processs the internal ringbuffer's bytes and execute if the payload is complete
pub fn process(&mut self, system: &mut impl System) {
let buffer = &mut self.buffer; // lifetime gynmastics, move the field out of self
if !self.rb.is_empty() {
while let Some(byte) = self.rb.dequeue() {
match byte {
STX => {
if self.state != State::Wait {
warn!("Partial buffer detected: {:?}", buffer);
}
/* Start of packet */
self.hex_idx = 0;
self.nsi_idx = 0;
buffer.clear();
self.state = State::Init; // activate processing
}
ETX => {
/* End of packet */
/* Finalize messge then reset state machine ready for next msg*/
self.state = State::Wait;
match buffer.btype {
Type::Unknown => {
// if the type cannot be determined abort, and wait until next STX
}
Type::Application => {
system.am().verify().unwrap_or_else(|e| {
error!("Failed to verify application: {:?}", e)
});
}
Type::Notification => {
info!(
"Adding notification from: {:?}, with section indexes {:?}",
buffer, self.nsi
);
self.nsi[2] = self.nsi_idx;
let nscopy = self.nsi;
system.nm().add(buffer, &nscopy).unwrap_or_else(|e| {
error!("Failed to add notification: {:?}", e)
});
}
Type::Syscall => {
info!("Parsing syscall from: {:?}", buffer);
match Syscall::from_str(buffer.as_str()) {
Ok(syscall) => syscall.execute(system),
Err(e) => error!("Failed to parse syscall {:?}", e),
}
}
}
}
PAYLOAD => {
match buffer.btype {
Type::Unknown => {
warn!("Dropping buffer of unknown type {:?}", buffer.btype);
self.state = State::Wait
}
Type::Application => {
if self.state == State::ApplicationChecksum {
// We've parsed the checksum, now we write the data into ram
self.state = State::ApplicationStore;
} else {
self.state = State::ApplicationChecksum;
// reset before we load the new application
system.am().kill().unwrap_or_else(|e| {
warn!("Failed to kill running app: {:?}", e)
});
}
}
Type::Notification => {
if self.state == State::NotificationSource {
// we've parsed the app source
self.nsi[0] = self.nsi_idx;
self.state = State::NotificationTitle;
} else if self.state == State::NotificationTitle {
// weve parsed the title
self.nsi[1] = self.nsi_idx;
self.state = State::NotificationBody;
} else {
self.state = State::NotificationSource; // new parse
}
}
_ => self.state = State::Payload,
}
}
_ => {
/* Run through byte state machine */
match self.state {
State::Init => {
buffer.determine_type(byte);
info!("New buffer of type {:?}", buffer.btype);
if let Type::Unknown = buffer.btype {
error!("Buffer type is unknown. Going back to wait state.");
self.state = State::Wait
}
}
State::Payload => {
buffer.write(byte);
}
State::ApplicationChecksum | State::ApplicationStore => {
self.hex_chars[self.hex_idx] = byte;
self.hex_idx += 1;
if self.hex_idx > 1 {
self.hex_idx = 0;
match self.state {
State::ApplicationChecksum => {
match hex_byte_to_byte(
self.hex_chars[0],
self.hex_chars[1],
) {
Ok(byte) => {
system
.am()
.write_checksum_byte(byte)
.unwrap_or_else(|e| {
error!(
"Failed to write checksum: {:?}",
e
)
});
}
Err(err) => {
error!(
"Failed to parse hex bytes to byte {:?}",
err
);
self.state = State::Wait; // abort
}
}
}
State::ApplicationStore => {
match hex_byte_to_byte(
self.hex_chars[0],
self.hex_chars[1],
) {
Ok(byte) => {
system
.am()
.write_ram_byte(byte)
.unwrap_or_else(|e| {
error!(
"Failed to write to ram: {:?}",
e
)
});
}
Err(err) => {
error!(
"Failed to parse hex bytes to byte {:?}",
err
);
self.state = State::Wait; // abort
}
}
}
_ => unreachable!(),
}
}
}
State::NotificationBody
| State::NotificationTitle
| State::NotificationSource => {
self.nsi_idx += 1;
buffer.write(byte);
}
State::Wait => {
// do nothing, useless bytes
}
}
}
}
}
}
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn ingress_syscall() {
let mut imgr = IngressManager::new();
let mut data = vec![STX, b'S', PAYLOAD];
for byte in "T00:00:00".bytes() {
data.push(byte);
}
data.push(ETX);
imgr.write(&data);
todo!("dummy system for tests");
// imgr.process();
// assert_eq!(imgr.state, State::Wait);
}
}