From a65325e15844f880132a69b447e4aec983cb30ab Mon Sep 17 00:00:00 2001
From: Alejandro Soto <alejandro@34project.org>
Date: Thu, 6 Jan 2022 03:42:56 -0600
Subject: Implement Symlink

---
 examples/passthrough.rs | 11 +++++++++++
 src/ops/entry.rs        | 27 +++++++++++++++++++++++++++
 src/ops/mod.rs          |  2 +-
 src/ops/traits.rs       |  9 ++++++++-
 src/session.rs          |  3 +++
 5 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/examples/passthrough.rs b/examples/passthrough.rs
index 32f50ca..7115fb1 100644
--- a/examples/passthrough.rs
+++ b/examples/passthrough.rs
@@ -161,6 +161,16 @@ impl Passthrough {
         reply.ok()
     }
 
+    async fn symlink<'o>(&mut self, (request, reply): Op<'o, ops::Symlink>) -> Done<'o> {
+        let (reply, inode) = reply.and_then(self.known(request.ino()))?;
+        let path = inode.path.join(request.name());
+
+        let (reply, ()) = reply.and_then(fs::symlink(request.target(), &path).await)?;
+        let (reply, metadata) = reply.and_then(fs::symlink_metadata(&path).await)?;
+
+        reply.known(New(&mut self.known, Inode::new(path, metadata)), Ttl::MAX)
+    }
+
     async fn open<'o>(&mut self, (request, reply): Op<'o, ops::Open>) -> Done<'o> {
         let (reply, inode) = reply.and_then(self.known(request.ino()))?;
         let options = {
@@ -368,6 +378,7 @@ async fn main_loop(session: Start, mut fs: Passthrough) -> FuseResult<()> {
                 Mkdir(mkdir) => fs.mkdir(mkdir.op()?).await,
                 Unlink(unlink) => fs.unlink(unlink.op()?).await,
                 Rmdir(rmdir) => fs.rmdir(rmdir.op()?).await,
+                Symlink(symlink) => fs.symlink(symlink.op()?).await,
                 //TODO: Link
                 Open(open) => fs.open(open.op()?).await,
                 Read(read) => fs.read(read.op()?).await,
diff --git a/src/ops/entry.rs b/src/ops/entry.rs
index 74072ef..435188a 100644
--- a/src/ops/entry.rs
+++ b/src/ops/entry.rs
@@ -16,12 +16,17 @@ pub enum Getattr {}
 pub enum Mkdir {}
 pub enum Unlink {}
 pub enum Rmdir {}
+pub enum Symlink {}
 pub enum Link {}
 
 pub trait RequestForget<'o>: Operation<'o> {
     fn forget_list<'a>(request: &'a Request<'o, Self>) -> ForgetList<'a>;
 }
 
+pub trait RequestTarget<'o>: Operation<'o> {
+    fn target<'a>(request: &'a Request<'o, Self>) -> &'a OsStr;
+}
+
 pub trait RequestLink<'o>: Operation<'o> {
     fn source_ino(request: &Request<'o, Self>) -> Ino;
 }
@@ -40,6 +45,7 @@ impl Sealed for Getattr {}
 impl Sealed for Mkdir {}
 impl Sealed for Unlink {}
 impl Sealed for Rmdir {}
+impl Sealed for Symlink {}
 impl Sealed for Link {}
 
 impl<'o> Operation<'o> for Forget {
@@ -72,6 +78,11 @@ impl<'o> Operation<'o> for Rmdir {
     type ReplyState = ();
 }
 
+impl<'o> Operation<'o> for Symlink {
+    type RequestBody = (&'o CStr, &'o CStr); // name(), target()
+    type ReplyState = ();
+}
+
 impl<'o> Operation<'o> for Link {
     type RequestBody = (&'o proto::LinkIn, &'o CStr);
     type ReplyState = ();
@@ -161,6 +172,22 @@ impl<'o> RequestName<'o> for Rmdir {
 
 impl<'o> ReplyOk<'o> for Rmdir {}
 
+impl<'o> RequestName<'o> for Symlink {
+    fn name<'a>(request: &'a Request<'o, Self>) -> &'a OsStr {
+        let (name, _target) = request.body;
+        c_to_os(name)
+    }
+}
+
+impl<'o> RequestTarget<'o> for Symlink {
+    fn target<'a>(request: &'a Request<'o, Self>) -> &'a OsStr {
+        let (_name, target) = request.body;
+        c_to_os(target)
+    }
+}
+
+impl<'o> ReplyKnown<'o> for Symlink {}
+
 impl<'o> RequestName<'o> for Link {
     fn name<'a>(request: &'a Request<'o, Self>) -> &'a OsStr {
         let (_header, name) = request.body;
diff --git a/src/ops/mod.rs b/src/ops/mod.rs
index 2970ef8..bc486b1 100644
--- a/src/ops/mod.rs
+++ b/src/ops/mod.rs
@@ -12,7 +12,7 @@ use bytemuck::{bytes_of, Pod};
 pub mod traits;
 
 pub use dir::{BufferedReaddir, Lookup, Readdir};
-pub use entry::{Forget, Getattr, Link, Mkdir, Rmdir, Unlink};
+pub use entry::{Forget, Getattr, Link, Mkdir, Rmdir, Symlink, Unlink};
 pub use global::{Init, Statfs};
 pub use open::{Access, Open, Opendir, Release, Releasedir};
 pub use rw::{Flush, Read, Readlink, Write};
diff --git a/src/ops/traits.rs b/src/ops/traits.rs
index 6a4b1ce..52aaed3 100644
--- a/src/ops/traits.rs
+++ b/src/ops/traits.rs
@@ -5,7 +5,7 @@ use crate::{
 
 pub use super::{
     dir::{ReplyEntries, ReplyFound},
-    entry::{ReplyStat, RequestForget, RequestLink},
+    entry::{ReplyStat, RequestForget, RequestLink, RequestTarget},
     global::ReplyFsInfo,
     open::{ReplyOpen, ReplyPermissionDenied},
     rw::ReplyAll,
@@ -146,6 +146,13 @@ impl<'o, O: Operation<'o>> Request<'o, O> {
         O::forget_list(self)
     }
 
+    pub fn target(&self) -> &OsStr
+    where
+        O: RequestTarget<'o>,
+    {
+        O::target(self)
+    }
+
     pub fn source_ino(&self) -> Ino
     where
         O: RequestLink<'o>,
diff --git a/src/session.rs b/src/session.rs
index 5f6336f..696d97a 100644
--- a/src/session.rs
+++ b/src/session.rs
@@ -62,6 +62,7 @@ pub enum Dispatch<'o> {
     Mkdir(Incoming<'o, ops::Mkdir>),
     Unlink(Incoming<'o, ops::Unlink>),
     Rmdir(Incoming<'o, ops::Rmdir>),
+    Symlink(Incoming<'o, ops::Symlink>),
     Link(Incoming<'o, ops::Link>),
     Open(Incoming<'o, ops::Open>),
     Read(Incoming<'o, ops::Read>),
@@ -259,6 +260,7 @@ impl<'o> Dispatch<'o> {
             Mkdir(incoming) => incoming.common,
             Unlink(incoming) => incoming.common,
             Rmdir(incoming) => incoming.common,
+            Symlink(incoming) => incoming.common,
             Link(incoming) => incoming.common,
             Open(incoming) => incoming.common,
             Read(incoming) => incoming.common,
@@ -343,6 +345,7 @@ impl Endpoint<'_> {
                 Mkdir => dispatch!(Mkdir),
                 Unlink => dispatch!(Unlink),
                 Rmdir => dispatch!(Rmdir),
+                Symlink => dispatch!(Symlink),
                 Link => dispatch!(Link),
                 Open => dispatch!(Open),
                 Read => dispatch!(Read),
-- 
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