embassy/embassy-usb-ncm/src/lib.rs
Dario Nieuwenhuis a8703b7598 Run rustfmt.
2022-06-12 22:22:31 +02:00

484 lines
15 KiB
Rust

#![no_std]
// This mod MUST go first, so that the others see its macros.
pub(crate) mod fmt;
use core::intrinsics::copy_nonoverlapping;
use core::mem::{size_of, MaybeUninit};
use embassy_usb::control::{self, ControlHandler, InResponse, OutResponse, Request};
use embassy_usb::driver::{Driver, Endpoint, EndpointError, EndpointIn, EndpointOut};
use embassy_usb::types::*;
use embassy_usb::Builder;
/// This should be used as `device_class` when building the `UsbDevice`.
pub const USB_CLASS_CDC: u8 = 0x02;
const USB_CLASS_CDC_DATA: u8 = 0x0a;
const CDC_SUBCLASS_NCM: u8 = 0x0d;
const CDC_PROTOCOL_NONE: u8 = 0x00;
const CDC_PROTOCOL_NTB: u8 = 0x01;
const CS_INTERFACE: u8 = 0x24;
const CDC_TYPE_HEADER: u8 = 0x00;
const CDC_TYPE_UNION: u8 = 0x06;
const CDC_TYPE_ETHERNET: u8 = 0x0F;
const CDC_TYPE_NCM: u8 = 0x1A;
const REQ_SEND_ENCAPSULATED_COMMAND: u8 = 0x00;
//const REQ_GET_ENCAPSULATED_COMMAND: u8 = 0x01;
//const REQ_SET_ETHERNET_MULTICAST_FILTERS: u8 = 0x40;
//const REQ_SET_ETHERNET_POWER_MANAGEMENT_PATTERN_FILTER: u8 = 0x41;
//const REQ_GET_ETHERNET_POWER_MANAGEMENT_PATTERN_FILTER: u8 = 0x42;
//const REQ_SET_ETHERNET_PACKET_FILTER: u8 = 0x43;
//const REQ_GET_ETHERNET_STATISTIC: u8 = 0x44;
const REQ_GET_NTB_PARAMETERS: u8 = 0x80;
//const REQ_GET_NET_ADDRESS: u8 = 0x81;
//const REQ_SET_NET_ADDRESS: u8 = 0x82;
//const REQ_GET_NTB_FORMAT: u8 = 0x83;
//const REQ_SET_NTB_FORMAT: u8 = 0x84;
//const REQ_GET_NTB_INPUT_SIZE: u8 = 0x85;
const REQ_SET_NTB_INPUT_SIZE: u8 = 0x86;
//const REQ_GET_MAX_DATAGRAM_SIZE: u8 = 0x87;
//const REQ_SET_MAX_DATAGRAM_SIZE: u8 = 0x88;
//const REQ_GET_CRC_MODE: u8 = 0x89;
//const REQ_SET_CRC_MODE: u8 = 0x8A;
//const NOTIF_MAX_PACKET_SIZE: u16 = 8;
//const NOTIF_POLL_INTERVAL: u8 = 20;
const NTB_MAX_SIZE: usize = 2048;
const SIG_NTH: u32 = 0x484d434e;
const SIG_NDP_NO_FCS: u32 = 0x304d434e;
const SIG_NDP_WITH_FCS: u32 = 0x314d434e;
const ALTERNATE_SETTING_DISABLED: u8 = 0x00;
const ALTERNATE_SETTING_ENABLED: u8 = 0x01;
/// Simple NTB header (NTH+NDP all in one) for sending packets
#[repr(packed)]
#[allow(unused)]
struct NtbOutHeader {
// NTH
nth_sig: u32,
nth_len: u16,
nth_seq: u16,
nth_total_len: u16,
nth_first_index: u16,
// NDP
ndp_sig: u32,
ndp_len: u16,
ndp_next_index: u16,
ndp_datagram_index: u16,
ndp_datagram_len: u16,
ndp_term1: u16,
ndp_term2: u16,
}
#[repr(packed)]
#[allow(unused)]
struct NtbParameters {
length: u16,
formats_supported: u16,
in_params: NtbParametersDir,
out_params: NtbParametersDir,
}
#[repr(packed)]
#[allow(unused)]
struct NtbParametersDir {
max_size: u32,
divisor: u16,
payload_remainder: u16,
out_alignment: u16,
max_datagram_count: u16,
}
fn byteify<T>(buf: &mut [u8], data: T) -> &[u8] {
let len = size_of::<T>();
unsafe { copy_nonoverlapping(&data as *const _ as *const u8, buf.as_mut_ptr(), len) }
&buf[..len]
}
pub struct State<'a> {
comm_control: MaybeUninit<CommControl<'a>>,
data_control: MaybeUninit<DataControl>,
shared: ControlShared,
}
impl<'a> State<'a> {
pub fn new() -> Self {
Self {
comm_control: MaybeUninit::uninit(),
data_control: MaybeUninit::uninit(),
shared: Default::default(),
}
}
}
/// Shared data between Control and CdcAcmClass
struct ControlShared {
mac_addr: [u8; 6],
}
impl Default for ControlShared {
fn default() -> Self {
ControlShared { mac_addr: [0; 6] }
}
}
struct CommControl<'a> {
mac_addr_string: StringIndex,
shared: &'a ControlShared,
mac_addr_str: [u8; 12],
}
impl<'d> ControlHandler for CommControl<'d> {
fn control_out(&mut self, req: control::Request, _data: &[u8]) -> OutResponse {
match req.request {
REQ_SEND_ENCAPSULATED_COMMAND => {
// We don't actually support encapsulated commands but pretend we do for standards
// compatibility.
OutResponse::Accepted
}
REQ_SET_NTB_INPUT_SIZE => {
// TODO
OutResponse::Accepted
}
_ => OutResponse::Rejected,
}
}
fn control_in<'a>(&'a mut self, req: Request, buf: &'a mut [u8]) -> InResponse<'a> {
match req.request {
REQ_GET_NTB_PARAMETERS => {
let res = NtbParameters {
length: size_of::<NtbParameters>() as _,
formats_supported: 1, // only 16bit,
in_params: NtbParametersDir {
max_size: NTB_MAX_SIZE as _,
divisor: 4,
payload_remainder: 0,
out_alignment: 4,
max_datagram_count: 0, // not used
},
out_params: NtbParametersDir {
max_size: NTB_MAX_SIZE as _,
divisor: 4,
payload_remainder: 0,
out_alignment: 4,
max_datagram_count: 1, // We only decode 1 packet per NTB
},
};
InResponse::Accepted(byteify(buf, res))
}
_ => InResponse::Rejected,
}
}
fn get_string(&mut self, index: StringIndex, _lang_id: u16) -> Option<&str> {
if index == self.mac_addr_string {
let mac_addr = self.shared.mac_addr;
let s = &mut self.mac_addr_str;
for i in 0..12 {
let n = (mac_addr[i / 2] >> ((1 - i % 2) * 4)) & 0xF;
s[i] = match n {
0x0..=0x9 => b'0' + n,
0xA..=0xF => b'A' + n - 0xA,
_ => unreachable!(),
}
}
Some(unsafe { core::str::from_utf8_unchecked(s) })
} else {
warn!("unknown string index requested");
None
}
}
}
struct DataControl {}
impl ControlHandler for DataControl {
fn set_alternate_setting(&mut self, alternate_setting: u8) {
match alternate_setting {
ALTERNATE_SETTING_ENABLED => info!("ncm: interface enabled"),
ALTERNATE_SETTING_DISABLED => info!("ncm: interface disabled"),
_ => unreachable!(),
}
}
}
pub struct CdcNcmClass<'d, D: Driver<'d>> {
_comm_if: InterfaceNumber,
comm_ep: D::EndpointIn,
data_if: InterfaceNumber,
read_ep: D::EndpointOut,
write_ep: D::EndpointIn,
_control: &'d ControlShared,
}
impl<'d, D: Driver<'d>> CdcNcmClass<'d, D> {
pub fn new(
builder: &mut Builder<'d, D>,
state: &'d mut State<'d>,
mac_address: [u8; 6],
max_packet_size: u16,
) -> Self {
state.shared.mac_addr = mac_address;
let mut func = builder.function(USB_CLASS_CDC, CDC_SUBCLASS_NCM, CDC_PROTOCOL_NONE);
// Control interface
let mut iface = func.interface();
let mac_addr_string = iface.string();
iface.handler(state.comm_control.write(CommControl {
mac_addr_string,
shared: &state.shared,
mac_addr_str: [0; 12],
}));
let comm_if = iface.interface_number();
let mut alt = iface.alt_setting(USB_CLASS_CDC, CDC_SUBCLASS_NCM, CDC_PROTOCOL_NONE);
alt.descriptor(
CS_INTERFACE,
&[
CDC_TYPE_HEADER, // bDescriptorSubtype
0x10,
0x01, // bcdCDC (1.10)
],
);
alt.descriptor(
CS_INTERFACE,
&[
CDC_TYPE_UNION, // bDescriptorSubtype
comm_if.into(), // bControlInterface
u8::from(comm_if) + 1, // bSubordinateInterface
],
);
alt.descriptor(
CS_INTERFACE,
&[
CDC_TYPE_ETHERNET, // bDescriptorSubtype
mac_addr_string.into(), // iMACAddress
0, // bmEthernetStatistics
0, // |
0, // |
0, // |
0xea, // wMaxSegmentSize = 1514
0x05, // |
0, // wNumberMCFilters
0, // |
0, // bNumberPowerFilters
],
);
alt.descriptor(
CS_INTERFACE,
&[
CDC_TYPE_NCM, // bDescriptorSubtype
0x00, // bcdNCMVersion
0x01, // |
0, // bmNetworkCapabilities
],
);
let comm_ep = alt.endpoint_interrupt_in(8, 255);
// Data interface
let mut iface = func.interface();
iface.handler(state.data_control.write(DataControl {}));
let data_if = iface.interface_number();
let _alt = iface.alt_setting(USB_CLASS_CDC_DATA, 0x00, CDC_PROTOCOL_NTB);
let mut alt = iface.alt_setting(USB_CLASS_CDC_DATA, 0x00, CDC_PROTOCOL_NTB);
let read_ep = alt.endpoint_bulk_out(max_packet_size);
let write_ep = alt.endpoint_bulk_in(max_packet_size);
CdcNcmClass {
_comm_if: comm_if,
comm_ep,
data_if,
read_ep,
write_ep,
_control: &state.shared,
}
}
pub fn split(self) -> (Sender<'d, D>, Receiver<'d, D>) {
(
Sender {
write_ep: self.write_ep,
seq: 0,
},
Receiver {
data_if: self.data_if,
comm_ep: self.comm_ep,
read_ep: self.read_ep,
},
)
}
}
pub struct Sender<'d, D: Driver<'d>> {
write_ep: D::EndpointIn,
seq: u16,
}
impl<'d, D: Driver<'d>> Sender<'d, D> {
pub async fn write_packet(&mut self, data: &[u8]) -> Result<(), EndpointError> {
let seq = self.seq;
self.seq = self.seq.wrapping_add(1);
const MAX_PACKET_SIZE: usize = 64; // TODO unhardcode
const OUT_HEADER_LEN: usize = 28;
let header = NtbOutHeader {
nth_sig: SIG_NTH,
nth_len: 0x0c,
nth_seq: seq,
nth_total_len: (data.len() + OUT_HEADER_LEN) as u16,
nth_first_index: 0x0c,
ndp_sig: SIG_NDP_NO_FCS,
ndp_len: 0x10,
ndp_next_index: 0x00,
ndp_datagram_index: OUT_HEADER_LEN as u16,
ndp_datagram_len: data.len() as u16,
ndp_term1: 0x00,
ndp_term2: 0x00,
};
// Build first packet on a buffer, send next packets straight from `data`.
let mut buf = [0; MAX_PACKET_SIZE];
let n = byteify(&mut buf, header);
assert_eq!(n.len(), OUT_HEADER_LEN);
if OUT_HEADER_LEN + data.len() < MAX_PACKET_SIZE {
// First packet is not full, just send it.
// No need to send ZLP because it's short for sure.
buf[OUT_HEADER_LEN..][..data.len()].copy_from_slice(data);
self.write_ep.write(&buf[..OUT_HEADER_LEN + data.len()]).await?;
} else {
let (d1, d2) = data.split_at(MAX_PACKET_SIZE - OUT_HEADER_LEN);
buf[OUT_HEADER_LEN..].copy_from_slice(d1);
self.write_ep.write(&buf).await?;
for chunk in d2.chunks(MAX_PACKET_SIZE) {
self.write_ep.write(&chunk).await?;
}
// Send ZLP if needed.
if d2.len() % MAX_PACKET_SIZE == 0 {
self.write_ep.write(&[]).await?;
}
}
Ok(())
}
}
pub struct Receiver<'d, D: Driver<'d>> {
data_if: InterfaceNumber,
comm_ep: D::EndpointIn,
read_ep: D::EndpointOut,
}
impl<'d, D: Driver<'d>> Receiver<'d, D> {
/// Reads a single packet from the OUT endpoint.
pub async fn read_packet(&mut self, buf: &mut [u8]) -> Result<usize, EndpointError> {
// Retry loop
loop {
// read NTB
let mut ntb = [0u8; NTB_MAX_SIZE];
let mut pos = 0;
loop {
let n = self.read_ep.read(&mut ntb[pos..]).await?;
pos += n;
if n < self.read_ep.info().max_packet_size as usize || pos == NTB_MAX_SIZE {
break;
}
}
let ntb = &ntb[..pos];
// Process NTB header (NTH)
let nth = match ntb.get(..12) {
Some(x) => x,
None => {
warn!("Received too short NTB");
continue;
}
};
let sig = u32::from_le_bytes(nth[0..4].try_into().unwrap());
if sig != SIG_NTH {
warn!("Received bad NTH sig.");
continue;
}
let ndp_idx = u16::from_le_bytes(nth[10..12].try_into().unwrap()) as usize;
// Process NTB Datagram Pointer (NDP)
let ndp = match ntb.get(ndp_idx..ndp_idx + 12) {
Some(x) => x,
None => {
warn!("NTH has an NDP pointer out of range.");
continue;
}
};
let sig = u32::from_le_bytes(ndp[0..4].try_into().unwrap());
if sig != SIG_NDP_NO_FCS && sig != SIG_NDP_WITH_FCS {
warn!("Received bad NDP sig.");
continue;
}
let datagram_index = u16::from_le_bytes(ndp[8..10].try_into().unwrap()) as usize;
let datagram_len = u16::from_le_bytes(ndp[10..12].try_into().unwrap()) as usize;
if datagram_index == 0 || datagram_len == 0 {
// empty, ignore. This is allowed by the spec, so don't warn.
continue;
}
// Process actual datagram, finally.
let datagram = match ntb.get(datagram_index..datagram_index + datagram_len) {
Some(x) => x,
None => {
warn!("NDP has a datagram pointer out of range.");
continue;
}
};
buf[..datagram_len].copy_from_slice(datagram);
return Ok(datagram_len);
}
}
/// Waits for the USB host to enable this interface
pub async fn wait_connection(&mut self) -> Result<(), EndpointError> {
loop {
self.read_ep.wait_enabled().await;
self.comm_ep.wait_enabled().await;
let buf = [
0xA1, //bmRequestType
0x00, //bNotificationType = NETWORK_CONNECTION
0x01, // wValue = connected
0x00,
self.data_if.into(), // wIndex = interface
0x00,
0x00, // wLength
0x00,
];
match self.comm_ep.write(&buf).await {
Ok(()) => break, // Done!
Err(EndpointError::Disabled) => {} // Got disabled again, wait again.
Err(e) => return Err(e),
}
}
Ok(())
}
}