open an owned file in AFC (#44)

* ability to open an owned file

Signed-off-by: Abdullah Al-Banna <abdu.albanna@proton.me>

* get the inner afc of an owned file without closing the file

Signed-off-by: Abdullah Al-Banna <abdu.albanna@proton.me>

---------

Signed-off-by: Abdullah Al-Banna <abdu.albanna@proton.me>

idevice/src/services/afc/file.rs

@@ -4,21 +4,31 @@ use std::{io::SeekFrom, marker::PhantomPinned, pin::Pin};
 
 use tokio::io::{AsyncRead, AsyncSeek, AsyncWrite};
 
-use super::inner_file::InnerFileDescriptor;
-use crate::IdeviceError;
+use crate::{
+    IdeviceError,
+    afc::{
+        AfcClient,
+        inner_file::{InnerFileDescriptor, OwnedInnerFileDescriptor},
+    },
+};
 
 #[derive(Debug)]
 pub struct FileDescriptor<'a> {
     inner: Pin<Box<InnerFileDescriptor<'a>>>,
 }
 
+#[derive(Debug)]
+pub struct OwnedFileDescriptor {
+    inner: Pin<Box<OwnedInnerFileDescriptor>>,
+}
+
 impl<'a> FileDescriptor<'a> {
     /// create a new FileDescriptor from a raw fd
     ///
     /// # Safety
     /// make sure the fd is an opened file, and that you got it from a previous
     /// FileDescriptor via `as_raw_fd()` method
-    pub unsafe fn new(client: &'a mut super::AfcClient, fd: u64, path: String) -> Self {
+    pub unsafe fn new(client: &'a mut AfcClient, fd: u64, path: String) -> Self {
         Self {
             inner: Box::pin(InnerFileDescriptor {
                 client,
@@ -30,20 +40,54 @@ impl<'a> FileDescriptor<'a> {
         }
     }
 
-    pub fn as_raw_fd(&self) -> u64 {
-        self.inner.fd
-    }
-}
-impl FileDescriptor<'_> {
-    /// Returns the current cursor position for the file
-    pub async fn seek_tell(&mut self) -> Result<u64, IdeviceError> {
-        self.inner.as_mut().seek_tell().await
-    }
-
     /// Closes the file descriptor
     pub async fn close(self) -> Result<(), IdeviceError> {
         self.inner.close().await
     }
+}
+
+impl OwnedFileDescriptor {
+    /// create a new OwnedFileDescriptor from a raw fd
+    ///
+    /// # Safety
+    /// make sure the fd is an opened file, and that you got it from a previous
+    /// OwnedFileDescriptor via `as_raw_fd()` method
+    pub unsafe fn new(client: AfcClient, fd: u64, path: String) -> Self {
+        Self {
+            inner: Box::pin(OwnedInnerFileDescriptor {
+                client,
+                fd,
+                path,
+                pending_fut: None,
+                _m: PhantomPinned,
+            }),
+        }
+    }
+
+    /// Closes the file descriptor
+    pub async fn close(self) -> Result<AfcClient, IdeviceError> {
+        self.inner.close().await
+    }
+
+    /// gets the owned afc
+    ///
+    /// # Safety
+    /// this get's the afc out without closing, if you want to get the afc and close the file, use
+    /// `.close()`
+    pub unsafe fn get_inner_afc(self) -> AfcClient {
+        self.inner.get_inner_afc()
+    }
+}
+
+crate::impl_to_structs!(FileDescriptor<'_>, OwnedFileDescriptor;  {
+    pub fn as_raw_fd(&self) -> u64 {
+        self.inner.fd
+    }
+
+    /// Returns the current cursor position for the file
+    pub async fn seek_tell(&mut self) -> Result<u64, IdeviceError> {
+        self.inner.as_mut().seek_tell().await
+    }
 
     /// Reads the entire contents of the file
     ///
@@ -60,9 +104,9 @@ impl FileDescriptor<'_> {
     pub async fn write_entire(&mut self, bytes: &[u8]) -> Result<(), IdeviceError> {
         self.inner.as_mut().write(bytes).await
     }
-}
+});
 
-impl AsyncRead for FileDescriptor<'_> {
+crate::impl_trait_to_structs!(AsyncRead for FileDescriptor<'_>, OwnedFileDescriptor; {
     fn poll_read(
         mut self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
@@ -71,9 +115,9 @@ impl AsyncRead for FileDescriptor<'_> {
         let inner = self.inner.as_mut();
         inner.poll_read(cx, buf)
     }
-}
+});
 
-impl AsyncWrite for FileDescriptor<'_> {
+crate::impl_trait_to_structs!(AsyncWrite for FileDescriptor<'_>, OwnedFileDescriptor; {
     fn poll_write(
         mut self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
@@ -98,9 +142,9 @@ impl AsyncWrite for FileDescriptor<'_> {
         let inner = self.inner.as_mut();
         inner.poll_shutdown(cx)
     }
-}
+});
 
-impl AsyncSeek for FileDescriptor<'_> {
+crate::impl_trait_to_structs!(AsyncSeek for FileDescriptor<'_>, OwnedFileDescriptor; {
     fn start_seek(mut self: Pin<&mut Self>, position: SeekFrom) -> std::io::Result<()> {
         let this = self.inner.as_mut();
         this.start_seek(position)
@@ -113,4 +157,4 @@ impl AsyncSeek for FileDescriptor<'_> {
         let this = self.inner.as_mut();
         this.poll_complete(cx)
     }
-}
+});

idevice/src/services/afc/inner_file.rs

@@ -5,11 +5,13 @@ use std::{io::SeekFrom, pin::Pin};
 use futures::{FutureExt, future::BoxFuture};
 use tokio::io::{AsyncRead, AsyncSeek, AsyncWrite};
 
-use crate::IdeviceError;
-
-use super::{
-    opcode::AfcOpcode,
-    packet::{AfcPacket, AfcPacketHeader},
+use crate::{
+    IdeviceError,
+    afc::{
+        AfcClient, MAGIC,
+        opcode::AfcOpcode,
+        packet::{AfcPacket, AfcPacketHeader},
+    },
 };
 
 /// Maximum transfer size for file operations (1MB)
@@ -32,19 +34,31 @@ pub(crate) enum PendingResult {
     Bytes(Vec<u8>),
 }
 
+type OwnedBoxFuture = Pin<Box<dyn Future<Output = Result<PendingResult, IdeviceError>> + Send>>;
+
 /// Handle for an open file on the device.
 /// Call close before dropping
 pub(crate) struct InnerFileDescriptor<'a> {
-    pub(crate) client: &'a mut super::AfcClient,
+    pub(crate) client: &'a mut AfcClient,
     pub(crate) fd: u64,
     pub(crate) path: String,
 
     pub(crate) pending_fut: Option<BoxFuture<'a, Result<PendingResult, IdeviceError>>>,
-
     pub(crate) _m: std::marker::PhantomPinned,
 }
 
-impl InnerFileDescriptor<'_> {
+/// Handle for an owned open file on the device.
+/// Call close before dropping
+pub(crate) struct OwnedInnerFileDescriptor {
+    pub(crate) client: AfcClient,
+    pub(crate) fd: u64,
+    pub(crate) path: String,
+
+    pub(crate) pending_fut: Option<OwnedBoxFuture>,
+    pub(crate) _m: std::marker::PhantomPinned,
+}
+
+crate::impl_to_structs!(InnerFileDescriptor<'_>, OwnedInnerFileDescriptor; {
     /// Generic helper to send an AFC packet and read the response
     pub async fn send_packet(
         self: Pin<&mut Self>,
@@ -57,7 +71,7 @@ impl InnerFileDescriptor<'_> {
 
         let header_len = header_payload.len() as u64 + AfcPacketHeader::LEN;
         let header = AfcPacketHeader {
-            magic: super::MAGIC,
+            magic: MAGIC,
             entire_len: header_len + payload.len() as u64,
             header_payload_len: header_len,
             packet_num: this.client.package_number,
@@ -115,15 +129,6 @@ impl InnerFileDescriptor<'_> {
         self.as_mut().seek_tell().await
     }
 
-    /// Closes the file descriptor
-    pub async fn close(mut self: Pin<Box<Self>>) -> Result<(), IdeviceError> {
-        let header_payload = self.fd.to_le_bytes().to_vec();
-
-        self.as_mut()
-            .send_packet(AfcOpcode::FileClose, header_payload, Vec::new())
-            .await?;
-        Ok(())
-    }
 
     /// Reads n size of contents from the file
     ///
@@ -188,7 +193,7 @@ impl InnerFileDescriptor<'_> {
 
     fn store_pending_read(mut self: Pin<&mut Self>, buf_rem: usize) {
         unsafe {
-            let this = self.as_mut().get_unchecked_mut() as *mut InnerFileDescriptor;
+            let this = self.as_mut().get_unchecked_mut() as *mut Self;
 
             let fut = Some(
                 // SAFETY: we already know that self is pinned
@@ -204,7 +209,7 @@ impl InnerFileDescriptor<'_> {
 
     fn store_pending_seek(mut self: Pin<&mut Self>, position: std::io::SeekFrom) {
         unsafe {
-            let this = self.as_mut().get_unchecked_mut() as *mut InnerFileDescriptor;
+            let this = self.as_mut().get_unchecked_mut() as *mut Self;
 
             let fut = Some(
                 Pin::new_unchecked(&mut *this)
@@ -221,7 +226,7 @@ impl InnerFileDescriptor<'_> {
         unsafe {
             let this = self.as_mut().get_unchecked_mut();
 
-            let this = this as *mut InnerFileDescriptor;
+            let this = this as *mut Self;
 
             // move the entire buffer into the future so we don't have to store it somewhere
             let pined_this = Pin::new_unchecked(&mut *this);
@@ -232,7 +237,7 @@ impl InnerFileDescriptor<'_> {
             (&mut *this).pending_fut = Some(fut);
         }
     }
-}
+});
 
 impl<'a> InnerFileDescriptor<'a> {
     fn get_or_init_read_fut(
@@ -268,9 +273,63 @@ impl<'a> InnerFileDescriptor<'a> {
             self.as_mut().get_unchecked_mut().pending_fut.take();
         }
     }
+
+    /// Closes the file descriptor
+    pub async fn close(mut self: Pin<Box<Self>>) -> Result<(), IdeviceError> {
+        let header_payload = self.fd.to_le_bytes().to_vec();
+
+        self.as_mut()
+            .send_packet(AfcOpcode::FileClose, header_payload, Vec::new())
+            .await?;
+        Ok(())
+    }
 }
 
-impl AsyncRead for InnerFileDescriptor<'_> {
+impl OwnedInnerFileDescriptor {
+    fn get_or_init_read_fut(mut self: Pin<&mut Self>, buf_rem: usize) -> &mut OwnedBoxFuture {
+        if self.as_ref().pending_fut.is_none() {
+            self.as_mut().store_pending_read(buf_rem);
+        }
+
+        unsafe { self.get_unchecked_mut().pending_fut.as_mut().unwrap() }
+    }
+
+    fn get_or_init_write_fut(mut self: Pin<&mut Self>, buf: &'_ [u8]) -> &mut OwnedBoxFuture {
+        if self.as_ref().pending_fut.is_none() {
+            self.as_mut().store_pending_write(buf);
+        }
+
+        unsafe { self.get_unchecked_mut().pending_fut.as_mut().unwrap() }
+    }
+
+    fn get_seek_fut(self: Pin<&mut Self>) -> Option<&mut OwnedBoxFuture> {
+        unsafe { self.get_unchecked_mut().pending_fut.as_mut() }
+    }
+
+    fn remove_pending_fut(mut self: Pin<&mut Self>) {
+        unsafe {
+            self.as_mut().get_unchecked_mut().pending_fut.take();
+        }
+    }
+
+    /// Closes the file descriptor
+    pub async fn close(mut self: Pin<Box<Self>>) -> Result<AfcClient, IdeviceError> {
+        let header_payload = self.fd.to_le_bytes().to_vec();
+
+        self.as_mut()
+            .send_packet(AfcOpcode::FileClose, header_payload, Vec::new())
+            .await?;
+
+        // we don't need it to be pinned anymore
+        Ok(unsafe { Pin::into_inner_unchecked(self) }.client)
+    }
+
+    pub fn get_inner_afc(self: Pin<Box<Self>>) -> AfcClient {
+        unsafe { Pin::into_inner_unchecked(self).client }
+    }
+}
+
+crate::impl_trait_to_structs!(AsyncRead for InnerFileDescriptor<'_>, OwnedInnerFileDescriptor; {
     fn poll_read(
         mut self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
@@ -293,9 +352,9 @@ impl AsyncRead for InnerFileDescriptor<'_> {
 
         std::task::Poll::Ready(Ok(()))
     }
-}
+});
 
-impl AsyncWrite for InnerFileDescriptor<'_> {
+crate::impl_trait_to_structs!(AsyncWrite for InnerFileDescriptor<'_>, OwnedInnerFileDescriptor; {
     fn poll_write(
         mut self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
@@ -329,9 +388,10 @@ impl AsyncWrite for InnerFileDescriptor<'_> {
     ) -> std::task::Poll<Result<(), std::io::Error>> {
         std::task::Poll::Ready(Ok(()))
     }
-}
 
-impl AsyncSeek for InnerFileDescriptor<'_> {
+});
+
+crate::impl_trait_to_structs!(AsyncSeek for InnerFileDescriptor<'_>, OwnedInnerFileDescriptor; {
     fn start_seek(self: Pin<&mut Self>, position: SeekFrom) -> std::io::Result<()> {
         self.store_pending_seek(position);
 
@@ -356,7 +416,7 @@ impl AsyncSeek for InnerFileDescriptor<'_> {
             _ => unreachable!("a non seek future was stored, this shouldn't happen"),
         }
     }
-}
+});
 
 impl std::fmt::Debug for InnerFileDescriptor<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -368,18 +428,31 @@ impl std::fmt::Debug for InnerFileDescriptor<'_> {
     }
 }
 
+impl std::fmt::Debug for OwnedInnerFileDescriptor {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("OwnedInnerFileDescriptor")
+            .field("client", &self.client)
+            .field("fd", &self.fd)
+            .field("path", &self.path)
+            .finish()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;
 
     use tokio::io::{AsyncReadExt, AsyncSeekExt, AsyncWriteExt};
 
-    use crate::usbmuxd::{UsbmuxdAddr, UsbmuxdConnection};
+    use crate::{
+        IdeviceService as _,
+        afc::opcode::AfcFopenMode,
+        usbmuxd::{UsbmuxdAddr, UsbmuxdConnection},
+    };
 
-    use super::super::*;
     use super::*;
 
-    async fn make_client() -> super::super::AfcClient {
+    async fn make_client() -> AfcClient {
         let mut u = UsbmuxdConnection::default()
             .await
             .expect("failed to connect to usbmuxd");

idevice/src/services/afc/inner_file_impl_macro.rs

@@ -0,0 +1,23 @@
+#[macro_export]
+macro_rules! impl_to_structs {
+    (
+        $( $name:ident $(<$li:lifetime>)? ),+;
+        $body:tt
+    ) => {
+        $(
+            impl $name $(<$li>)? $body
+        )+
+    };
+}
+
+#[macro_export]
+macro_rules! impl_trait_to_structs {
+    (
+        $trit:ident for $( $name:ident $(<$li:lifetime>)? ),+;
+        $body:tt
+    ) => {
+        $(
+            impl $trit for $name $(<$li>)? $body
+        )+
+    };
+}

idevice/src/services/afc/mod.rs

@@ -6,16 +6,20 @@
 use std::collections::HashMap;
 
 use errors::AfcError;
-use file::FileDescriptor;
 use opcode::{AfcFopenMode, AfcOpcode};
 use packet::{AfcPacket, AfcPacketHeader};
 use tracing::warn;
 
-use crate::{Idevice, IdeviceError, IdeviceService, obf};
+use crate::{
+    Idevice, IdeviceError, IdeviceService,
+    afc::file::{FileDescriptor, OwnedFileDescriptor},
+    obf,
+};
 
 pub mod errors;
 pub mod file;
 mod inner_file;
+mod inner_file_impl_macro;
 pub mod opcode;
 pub mod packet;
 
@@ -415,6 +419,51 @@ impl AfcClient {
         Ok(unsafe { FileDescriptor::new(self, fd, path) })
     }
 
+    /// Opens an owned file on the device
+    ///
+    /// # Arguments
+    /// * `path` - Path to the file to open
+    /// * `mode` - Opening mode (read, write, etc.)
+    ///
+    /// # Returns
+    /// A `OwnedFileDescriptor` struct for the opened file
+    pub async fn open_owned(
+        mut self,
+        path: impl Into<String>,
+        mode: AfcFopenMode,
+    ) -> Result<OwnedFileDescriptor, IdeviceError> {
+        let path = path.into();
+        let mut header_payload = (mode as u64).to_le_bytes().to_vec();
+        header_payload.extend(path.as_bytes());
+        let header_len = header_payload.len() as u64 + AfcPacketHeader::LEN;
+
+        let header = AfcPacketHeader {
+            magic: MAGIC,
+            entire_len: header_len, // it's the same since the payload is empty for this
+            header_payload_len: header_len,
+            packet_num: self.package_number,
+            operation: AfcOpcode::FileOpen,
+        };
+        self.package_number += 1;
+
+        let packet = AfcPacket {
+            header,
+            header_payload,
+            payload: Vec::new(),
+        };
+
+        self.send(packet).await?;
+        let res = self.read().await?;
+        if res.header_payload.len() < 8 {
+            warn!("Header payload fd is less than 8 bytes");
+            return Err(IdeviceError::UnexpectedResponse);
+        }
+        let fd = u64::from_le_bytes(res.header_payload[..8].try_into().unwrap());
+
+        // we know it's a valid fd
+        Ok(unsafe { OwnedFileDescriptor::new(self, fd, path) })
+    }
+
     /// Creates a hard or symbolic link
     ///
     /// # Arguments