Merge pull request #185 from MirnaMuhammad98/nfc-driver-interface

Add NFC driver interface

Cargo.toml

@@ -28,6 +28,7 @@ ram_storage = []
 verbose = ["debug_ctap", "libtock_drivers/verbose_usb"]
 with_ctap1 = ["crypto/with_ctap1"]
 with_ctap2_1 = []
+with_nfc = ["libtock_drivers/with_nfc"]
 
 [dev-dependencies]
 elf2tab = "0.6.0"

deploy.py

@@ -846,6 +846,13 @@ if __name__ == "__main__":
       help=("Compiles the OpenSK application with backward compatible "
             "support for CTAP2.1 protocol."),
   )
+  main_parser.add_argument(
+      "--nfc",
+      action="append_const",
+      const="with_nfc",
+      dest="features",
+      help=("Compiles the OpenSK application with support for nfc."),
+  )
   main_parser.add_argument(
       "--regen-keys",
       action="store_true",

third_party/libtock-drivers/Cargo.toml

@@ -14,3 +14,4 @@ libtock_core = { path = "../../third_party/libtock-rs/core" }
 [features]
 debug_ctap = []
 verbose_usb = ["debug_ctap"]
+with_nfc=[]

third_party/libtock-drivers/src/lib.rs

@@ -3,6 +3,8 @@
 pub mod buttons;
 pub mod console;
 pub mod led;
+#[cfg(feature = "with_nfc")]
+pub mod nfc;
 pub mod result;
 pub mod rng;
 pub mod timer;

third_party/libtock-drivers/src/nfc.rs

@@ -0,0 +1,103 @@
+use crate::result::TockResult;
+use crate::util;
+use core::cell::Cell;
+use core::mem;
+use libtock_core::{callback, syscalls};
+
+const DRIVER_NUMBER: usize = 0x30003;
+
+mod command_nr {
+    pub const CHECK: usize = 0;
+    pub const TRANSMIT: usize = 1;
+    pub const RECEIVE: usize = 2;
+    pub const EMULATE: usize = 3;
+    pub const CONFIGURE: usize = 4;
+}
+
+mod subscribe_nr {
+    pub const TRANSMIT: usize = 1;
+    pub const RECEIVE: usize = 2;
+}
+
+mod allow_nr {
+    pub const TRANSMIT: usize = 1;
+    pub const RECEIVE: usize = 2;
+}
+
+#[allow(dead_code)]
+#[derive(Clone, Copy)]
+pub struct RecvOp {
+    pub result_code: usize,
+    pub recv_amount: usize,
+}
+
+pub struct NfcTag {}
+
+impl NfcTag {
+    /// Check the existence of an NFC driver.
+    pub fn setup() -> bool {
+        syscalls::command(DRIVER_NUMBER, command_nr::CHECK, 0, 0).is_ok()
+    }
+
+    pub fn enable_emulation() -> bool {
+        NfcTag::emulate(true)
+    }
+
+    pub fn disable_emulation() -> bool {
+        NfcTag::emulate(false)
+    }
+
+    fn emulate(enabled: bool) -> bool {
+        syscalls::command(DRIVER_NUMBER, command_nr::EMULATE, enabled as usize, 0).is_ok()
+    }
+
+    /// Configure the tag type command.
+    pub fn configure(tag_type: u8) -> bool {
+        syscalls::command(DRIVER_NUMBER, command_nr::CONFIGURE, tag_type as usize, 0).is_ok()
+    }
+
+    /// 1. Share with the driver a buffer.
+    /// 2. Subscribe to having a successful receive callback.
+    /// 3. Issue the request for reception.
+    pub fn receive(buf: &mut [u8; 256]) -> TockResult<RecvOp> {
+        let result = syscalls::allow(DRIVER_NUMBER, allow_nr::RECEIVE, buf)?;
+        // set callback with 2 arguments, to receive ReturnCode and RX Amount
+        let recv_data = Cell::new(None);
+        let mut callback = |result, amount| {
+            recv_data.set(Some(RecvOp {
+                result_code: result,
+                recv_amount: amount,
+            }))
+        };
+        let subscription = syscalls::subscribe::<callback::Identity2Consumer, _>(
+            DRIVER_NUMBER,
+            subscribe_nr::RECEIVE,
+            &mut callback,
+        )?;
+        syscalls::command(DRIVER_NUMBER, command_nr::RECEIVE, 0, 0)?;
+        util::yieldk_for(|| recv_data.get().is_some());
+        mem::drop(subscription);
+        mem::drop(result);
+        Ok(recv_data.get().unwrap())
+    }
+
+    /// 1. Share with the driver a buffer containing the app's reply.
+    /// 2. Subscribe to having a successful transmission callback.
+    /// 3. Issue the request for transmitting.
+    pub fn transmit(buf: &mut [u8], amount: usize) -> TockResult<usize> {
+        let result = syscalls::allow(DRIVER_NUMBER, allow_nr::TRANSMIT, buf)?;
+        // set callback with 1 argument, to receive ReturnCode
+        let result_code = Cell::new(None);
+        let mut callback = |result| result_code.set(Some(result));
+        let subscription = syscalls::subscribe::<callback::Identity1Consumer, _>(
+            DRIVER_NUMBER,
+            subscribe_nr::TRANSMIT,
+            &mut callback,
+        )?;
+        syscalls::command(DRIVER_NUMBER, command_nr::TRANSMIT, amount, 0)?;
+        util::yieldk_for(|| result_code.get().is_some());
+        mem::drop(subscription);
+        mem::drop(result);
+        Ok(result_code.get().unwrap())
+    }
+}