channel: send files over channels

lib/kernel-util/src/runtime/executor.rs

@@ -1,10 +1,17 @@
 use core::task::{Context, Poll};
 
 use alloc::{boxed::Box, format, sync::Arc};
-use futures_util::{task::waker_ref, Future};
+use futures_util::{
+    task::{waker_ref, ArcWake, WakerRef},
+    Future,
+};
 use yggdrasil_abi::error::Error;
 
-use crate::thread::Thread;
+use crate::{
+    api::__cpu_index,
+    cpu_index,
+    thread::{CurrentThread, Thread},
+};
 
 use super::{
     task::{Task, Termination},
@@ -48,6 +55,7 @@ pub fn run_to_completion<'a, T, F: Future<Output = T> + Send + 'a>(future: F) ->
 
     loop {
         let thread = Thread::current();
+
         let waker = waker_ref(&thread);
         let context = &mut Context::from_waker(&waker);
 

lib/vfs/src/channel.rs

@@ -15,18 +15,29 @@ use kernel_util::{
     block,
     sync::{mutex::Mutex, IrqSafeSpinlock, LockMethod},
 };
-use yggdrasil_abi::{error::Error, io::MessageDestination};
+use yggdrasil_abi::{
+    error::Error,
+    io::{MessageDestination, ReceivedMessageMetadata},
+};
 
-use crate::FileReadiness;
+use crate::{FileReadiness, FileRef};
 
 pub struct Channel {
     last_id: AtomicU32,
     subscriptions: Mutex<BTreeMap<u32, Arc<Subscription>>>,
 }
 
+/// Describes message payload
+pub enum MessagePayload {
+    /// Payload contains a file
+    File(FileRef),
+    /// Payload contains byte data
+    Data(Box<[u8]>),
+}
+
 pub struct Message {
-    source: u32,
-    data: Box<[u8]>,
+    pub source: u32,
+    pub payload: MessagePayload,
 }
 
 pub struct Subscription {
@@ -54,27 +65,22 @@ impl ChannelDescriptor {
         Self { tx, rx, id }
     }
 
-    pub fn receive_message(&self, buf: &mut [u8]) -> Result<(u32, usize), Error> {
+    pub fn receive_message(&self) -> Result<Arc<Message>, Error> {
         let Some(rx) = self.rx.as_ref() else {
             return Err(Error::InvalidOperation);
         };
 
-        let message = rx.receive_message_inner()?;
-        let len = message.data.len();
-
-        if buf.len() < len {
-            return Err(Error::MissingData);
+        rx.receive_message_inner()
     }
 
-        buf[..len].copy_from_slice(&message.data);
-
-        Ok((message.source, len))
-    }
-
-    pub fn send_message(&self, msg: &[u8], dst: MessageDestination) -> Result<(), Error> {
+    pub fn send_message(
+        &self,
+        payload: MessagePayload,
+        dst: MessageDestination,
+    ) -> Result<(), Error> {
         let message = Arc::new(Message {
             source: self.id,
-            data: Box::from(msg),
+            payload,
         });
 
         let lock = self.tx.subscriptions.lock()?;

lib/vfs/src/file/mod.rs

@@ -37,7 +37,7 @@ mod pipe;
 mod regular;
 
 /// Per-file optional instance data created when a regular file is opened
-pub type InstanceData = Box<dyn Any + Send + Sync>;
+pub type InstanceData = Arc<dyn Any + Send + Sync>;
 
 /// Describes the starting position of the directory
 pub enum DirectoryOpenPosition {
@@ -159,6 +159,14 @@ impl File {
         })))
     }
 
+    /// Clones an open file for sending it to another process
+    pub fn send(&self) -> Result<Arc<Self>, Error> {
+        match self {
+            Self::Regular(file) => Ok(Arc::new(Self::Regular(file.clone()))),
+            _ => Err(Error::InvalidOperation),
+        }
+    }
+
     /// Reads entries from the directory
     pub fn read_dir(&self, entries: &mut [MaybeUninit<DirectoryEntry>]) -> Result<usize, Error> {
         match self {

lib/vfs/src/file/regular.rs

@@ -4,6 +4,7 @@ use yggdrasil_abi::{error::Error, io::SeekFrom};
 use super::InstanceData;
 use crate::node::NodeRef;
 
+#[derive(Clone)]
 pub struct RegularFile {
     pub(super) node: NodeRef,
     pub(super) read: bool,

lib/vfs/src/lib.rs

@@ -19,6 +19,7 @@ pub(crate) mod path;
 pub(crate) mod poll;
 pub(crate) mod traits;
 
+pub use channel::MessagePayload;
 pub use device::CharDevice;
 pub use file::{DirectoryOpenPosition, File, FileRef, FileSet, InstanceData};
 pub use ioctx::{Action, IoContext};

lib/vfs/src/node/impls.rs

@@ -141,7 +141,7 @@ where
             return Err(Error::ReadOnly);
         }
         let t = (self.read)()?;
-        Ok((0, Some(Box::new(t.as_instance_data()))))
+        Ok((0, Some(Arc::new(t.as_instance_data()))))
     }
 
     fn read(
@@ -240,10 +240,10 @@ where
         if opts.contains(OpenOptions::READ | OpenOptions::WRITE) {
             Err(Error::InvalidOperation)
         } else if opts.contains(OpenOptions::WRITE) {
-            Ok((0, Some(Box::new(FnNodeData::write()))))
+            Ok((0, Some(Arc::new(FnNodeData::write()))))
         } else if opts.contains(OpenOptions::READ) {
             let t = (self.read)()?;
-            Ok((0, Some(Box::new(FnNodeData::read(t)))))
+            Ok((0, Some(Arc::new(FnNodeData::read(t)))))
         } else {
             Err(Error::InvalidOperation)
         }

src/arch/mod.rs

@@ -35,7 +35,10 @@ use kernel_util::{
     sync::IrqGuard,
 };
 
-use crate::{mem::phys::PhysicalMemoryRegion, task::sched::CpuQueue};
+use crate::{
+    mem::phys::PhysicalMemoryRegion,
+    task::{sched::CpuQueue, Cpu},
+};
 
 cfg_if! {
     if #[cfg(target_arch = "aarch64")] {
@@ -278,8 +281,7 @@ fn __release_irq_guard(mask: bool) {
 
 #[no_mangle]
 fn __cpu_index() -> usize {
-    todo!()
-    // Cpu::local_id() as _
+    Cpu::local().id() as _
 }
 
 #[no_mangle]

src/syscall/mod.rs

@@ -5,15 +5,15 @@ use abi::{
     error::Error,
     io::{
         DeviceRequest, DirectoryEntry, FileAttr, FileMode, MessageDestination, OpenOptions,
-        PollControl, RawFd, SeekFrom,
+        PollControl, RawFd, ReceivedMessageMetadata, SeekFrom, SentMessage,
     },
     mem::MappingSource,
     process::{ExitCode, MutexOperation, Signal, SpawnOption, SpawnOptions, ThreadSpawnOptions},
     syscall::SyscallFunction,
 };
-use alloc::sync::Arc;
+use alloc::{boxed::Box, sync::Arc};
 use kernel_util::{block, mem::table::EntryLevelExt, runtime, sync::IrqSafeSpinlockGuard};
-use vfs::{File, IoContext, NodeRef, Read, Seek, Write};
+use vfs::{File, IoContext, MessagePayload, NodeRef, Read, Seek, Write};
 use yggdrasil_abi::{error::SyscallResult, io::MountOptions};
 
 use crate::{
@@ -372,31 +372,63 @@ fn syscall_handler(func: SyscallFunction, args: &[u64]) -> Result<usize, Error>
         }
         SyscallFunction::SendMessage => {
             let fd = RawFd::from(args[0] as u32);
-            let buf = arg_buffer_ref(args[1] as usize, args[2] as usize)?;
-            let destination = MessageDestination::from(args[3]);
+            let message = arg_user_ref::<SentMessage>(args[1] as usize)?;
+            let destination = MessageDestination::from(args[2]);
 
             run_with_io(process, |io| {
                 let file = io.files.file(fd)?;
                 let channel = file.as_message_channel()?;
 
-                channel.send_message(buf, destination)?;
+                match message {
+                    &SentMessage::File(fd) => {
+                        let sent_file = io.files.file(fd)?;
+
+                        channel
+                            .send_message(MessagePayload::File(sent_file.clone()), destination)?;
+                    }
+                    &SentMessage::Data(data) => {
+                        channel.send_message(MessagePayload::Data(Box::from(data)), destination)?;
+                    }
+                }
 
                 Ok(0)
             })
         }
         SyscallFunction::ReceiveMessage => {
             let fd = RawFd::from(args[0] as u32);
-            let buf = arg_buffer_mut(args[1] as usize, args[2] as usize)?;
-            let from = arg_user_mut::<MaybeUninit<u32>>(args[3] as usize)?;
+            let metadata = arg_user_mut::<MaybeUninit<ReceivedMessageMetadata>>(args[1] as usize)?;
+            let buf = arg_buffer_mut(args[2] as usize, args[3] as usize)?;
+            let from = arg_user_mut::<MaybeUninit<u32>>(args[4] as usize)?;
 
-            run_with_io(process, |io| {
+            run_with_io(process, |mut io| {
                 let file = io.files.file(fd)?;
                 let channel = file.as_message_channel()?;
 
-                let (id, len) = channel.receive_message(buf)?;
-                from.write(id);
+                let message = channel.receive_message()?;
+
+                from.write(message.source);
+
+                match &message.payload {
+                    MessagePayload::Data(data) => {
+                        // TODO allow truncated messages?
+                        let len = data.len();
+                        if buf.len() < len {
+                            return Err(Error::MissingData);
+                        }
+
+                        metadata.write(ReceivedMessageMetadata::Data(len));
+                        buf[..len].copy_from_slice(&data);
 
                         Ok(len)
+                    }
+                    MessagePayload::File(file) => {
+                        let fd = io.files.place_file(file.clone(), true)?;
+
+                        metadata.write(ReceivedMessageMetadata::File(fd));
+
+                        Ok(0)
+                    }
+                }
             })
         }
         // Process management