std: sys: net: uefi: Implement read_vectored

library/std/src/sys/net/connection/uefi/mod.rs

@@ -69,12 +69,11 @@ impl TcpStream {
     }
 
     pub fn read_vectored(&self, buf: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        // FIXME: UEFI does support vectored read, so implement that.
-        crate::io::default_read_vectored(|b| self.read(b), buf)
+        self.inner.read_vectored(buf, self.read_timeout()?)
     }
 
     pub fn is_read_vectored(&self) -> bool {
-        false
+        true
     }
 
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {

library/std/src/sys/net/connection/uefi/tcp.rs

@@ -1,5 +1,5 @@
 use super::tcp4;
-use crate::io::{self, IoSlice};
+use crate::io::{self, IoSlice, IoSliceMut};
 use crate::net::SocketAddr;
 use crate::ptr::NonNull;
 use crate::sys::{helpers, unsupported};
@@ -44,6 +44,16 @@ impl Tcp {
         }
     }
 
+    pub(crate) fn read_vectored(
+        &self,
+        buf: &mut [IoSliceMut<'_>],
+        timeout: Option<Duration>,
+    ) -> io::Result<usize> {
+        match self {
+            Self::V4(client) => client.read_vectored(buf, timeout),
+        }
+    }
+
     pub(crate) fn ttl(&self) -> io::Result<u32> {
         match self {
             Self::V4(client) => client.get_mode_data().map(|x| x.time_to_live.into()),

library/std/src/sys/net/connection/uefi/tcp4.rs

@@ -1,7 +1,7 @@
 use r_efi::efi::{self, Status};
 use r_efi::protocols::tcp4;
 
-use crate::io::{self, IoSlice};
+use crate::io::{self, IoSlice, IoSliceMut};
 use crate::net::SocketAddrV4;
 use crate::ptr::NonNull;
 use crate::sync::atomic::{AtomicBool, Ordering};
@@ -193,30 +193,74 @@ impl Tcp4 {
     }
 
     pub(crate) fn read(&self, buf: &mut [u8], timeout: Option<Duration>) -> io::Result<usize> {
-        let evt = unsafe { self.create_evt() }?;
-        let completion_token =
-            tcp4::CompletionToken { event: evt.as_ptr(), status: Status::SUCCESS };
         let data_len = u32::try_from(buf.len()).unwrap_or(u32::MAX);
 
         let fragment = tcp4::FragmentData {
             fragment_length: data_len,
             fragment_buffer: buf.as_mut_ptr().cast::<crate::ffi::c_void>(),
         };
-        let mut tx_data = tcp4::ReceiveData {
+        let mut rx_data = tcp4::ReceiveData {
             urgent_flag: r_efi::efi::Boolean::FALSE,
             data_length: data_len,
             fragment_count: 1,
             fragment_table: [fragment],
         };
 
-        let protocol = self.protocol.as_ptr();
-        let mut token = tcp4::IoToken {
-            completion_token,
-            packet: tcp4::IoTokenPacket {
-                rx_data: (&raw mut tx_data).cast::<tcp4::ReceiveData<0>>(),
-            },
+        self.read_inner((&raw mut rx_data).cast(), timeout).map(|_| data_len as usize)
+    }
+
+    pub(crate) fn read_vectored(
+        &self,
+        buf: &[IoSliceMut<'_>],
+        timeout: Option<Duration>,
+    ) -> io::Result<usize> {
+        let mut data_length = 0u32;
+        let mut fragment_count = 0u32;
+
+        // Calculate how many IoSlice in buf can be transmitted.
+        for i in buf {
+            // IoSlice length is always <= u32::MAX in UEFI.
+            match data_length.checked_add(u32::try_from(i.len()).expect("value is stored as a u32"))
+            {
+                Some(x) => data_length = x,
+                None => break,
+            }
+            fragment_count += 1;
+        }
+
+        let rx_data_size = size_of::<tcp4::ReceiveData<0>>()
+            + size_of::<tcp4::FragmentData>() * (fragment_count as usize);
+        let mut rx_data = helpers::UefiBox::<tcp4::ReceiveData>::new(rx_data_size)?;
+        rx_data.write(tcp4::ReceiveData {
+            urgent_flag: r_efi::efi::Boolean::FALSE,
+            data_length,
+            fragment_count,
+            fragment_table: [],
+        });
+        unsafe {
+            // SAFETY: IoSlice and FragmentData are guaranteed to have same layout.
+            crate::ptr::copy_nonoverlapping(
+                buf.as_ptr().cast(),
+                (*rx_data.as_mut_ptr()).fragment_table.as_mut_ptr(),
+                fragment_count as usize,
+            );
         };
 
+        self.read_inner(rx_data.as_mut_ptr(), timeout).map(|_| data_length as usize)
+    }
+
+    pub(crate) fn read_inner(
+        &self,
+        rx_data: *mut tcp4::ReceiveData,
+        timeout: Option<Duration>,
+    ) -> io::Result<()> {
+        let evt = unsafe { self.create_evt() }?;
+        let completion_token =
+            tcp4::CompletionToken { event: evt.as_ptr(), status: Status::SUCCESS };
+
+        let protocol = self.protocol.as_ptr();
+        let mut token = tcp4::IoToken { completion_token, packet: tcp4::IoTokenPacket { rx_data } };
+
         let r = unsafe { ((*protocol).receive)(protocol, &mut token) };
         if r.is_error() {
             return Err(io::Error::from_raw_os_error(r.as_usize()));
@@ -227,7 +271,7 @@ impl Tcp4 {
         if completion_token.status.is_error() {
             Err(io::Error::from_raw_os_error(completion_token.status.as_usize()))
         } else {
-            Ok(data_len as usize)
+            Ok(())
         }
     }