From c9f61ec72f196ed94d05835f1635c697eb0c73a8 Mon Sep 17 00:00:00 2001
From: Alex Zenla <alex@mycelium.engineering>
Date: Mon, 8 Jan 2024 23:23:26 -0800
Subject: [PATCH] introduce xencl for high-level interaction with xen

---
 Cargo.toml                |  3 +-
 xencl/Cargo.toml          | 15 +++++++++
 xencl/examples/simple.rs  |  9 ++++++
 xencl/src/lib.rs          | 68 +++++++++++++++++++++++++++++++++++++++
 xenstore/examples/list.rs |  2 +-
 xenstore/src/client.rs    | 13 ++++++--
 6 files changed, 105 insertions(+), 5 deletions(-)
 create mode 100644 xencl/Cargo.toml
 create mode 100644 xencl/examples/simple.rs
 create mode 100644 xencl/src/lib.rs

diff --git a/Cargo.toml b/Cargo.toml
index a846165..c9dac42 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 members = [
     "xenstore",
     "xenevtchn",
-    "xencall"
+    "xencall",
+    "xencl"
 ]
 resolver = "2"
diff --git a/xencl/Cargo.toml b/xencl/Cargo.toml
new file mode 100644
index 0000000..c058cf2
--- /dev/null
+++ b/xencl/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "xencl"
+version = "0.0.1"
+edition = "2021"
+resolver = "2"
+
+[dependencies.xenstore]
+path = "../xenstore"
+
+[lib]
+path = "src/lib.rs"
+
+[[example]]
+name = "xencl-simple"
+path = "examples/simple.rs"
diff --git a/xencl/examples/simple.rs b/xencl/examples/simple.rs
new file mode 100644
index 0000000..ba18160
--- /dev/null
+++ b/xencl/examples/simple.rs
@@ -0,0 +1,9 @@
+use std::collections::HashMap;
+use xencl::{XenClient, XenClientError};
+
+fn main() -> Result<(), XenClientError> {
+    let mut client = XenClient::open()?;
+    let entries: HashMap<String, String> = HashMap::new();
+    client.create(2, entries)?;
+    Ok(())
+}
diff --git a/xencl/src/lib.rs b/xencl/src/lib.rs
new file mode 100644
index 0000000..838e3d9
--- /dev/null
+++ b/xencl/src/lib.rs
@@ -0,0 +1,68 @@
+use std::collections::HashMap;
+use std::error::Error;
+use std::fmt::{Display, Formatter};
+use xenstore::bus::XsdBusError;
+use xenstore::client::{XsdClient, XsdInterface};
+
+pub struct XenClient {
+    store: XsdClient,
+}
+
+#[derive(Debug)]
+pub struct XenClientError {
+    message: String,
+}
+
+impl XenClientError {
+    pub fn new(msg: &str) -> XenClientError {
+        XenClientError {
+            message: msg.to_string(),
+        }
+    }
+}
+
+impl Display for XenClientError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl Error for XenClientError {
+    fn description(&self) -> &str {
+        &self.message
+    }
+}
+
+impl From<std::io::Error> for XenClientError {
+    fn from(value: std::io::Error) -> Self {
+        XenClientError::new(value.to_string().as_str())
+    }
+}
+
+impl From<XsdBusError> for XenClientError {
+    fn from(value: XsdBusError) -> Self {
+        XenClientError::new(value.to_string().as_str())
+    }
+}
+
+impl XenClient {
+    pub fn open() -> Result<XenClient, XenClientError> {
+        let store = XsdClient::open()?;
+        Ok(XenClient { store })
+    }
+
+    pub fn create(
+        &mut self,
+        domid: u32,
+        entries: HashMap<String, String>,
+    ) -> Result<(), XenClientError> {
+        let domain = self.store.get_domain_path(domid)?;
+        let mut tx = self.store.transaction()?;
+        for (key, value) in entries {
+            let path = format!("{}/{}", domain, key);
+            tx.write(path.as_str(), value.into_bytes())?;
+        }
+        tx.commit()?;
+        Ok(())
+    }
+}
diff --git a/xenstore/examples/list.rs b/xenstore/examples/list.rs
index 9843427..9827d03 100644
--- a/xenstore/examples/list.rs
+++ b/xenstore/examples/list.rs
@@ -29,7 +29,7 @@ fn list_recursive(client: &mut XsdClient, level: usize, path: &str) -> Result<()
 }
 
 fn main() -> Result<(), XsdBusError> {
-    let mut client = XsdClient::new()?;
+    let mut client = XsdClient::open()?;
     list_recursive(&mut client, 0, "/")?;
     Ok(())
 }
diff --git a/xenstore/src/client.rs b/xenstore/src/client.rs
index f31577b..6a4dd28 100644
--- a/xenstore/src/client.rs
+++ b/xenstore/src/client.rs
@@ -1,7 +1,7 @@
 use crate::bus::{XsdBusError, XsdSocket};
 use crate::sys::{
-    XSD_DIRECTORY, XSD_MKDIR, XSD_READ, XSD_RM, XSD_TRANSACTION_END, XSD_TRANSACTION_START,
-    XSD_WRITE,
+    XSD_DIRECTORY, XSD_GET_DOMAIN_PATH, XSD_MKDIR, XSD_READ, XSD_RM, XSD_TRANSACTION_END,
+    XSD_TRANSACTION_START, XSD_WRITE,
 };
 use std::ffi::CString;
 
@@ -18,7 +18,7 @@ pub trait XsdInterface {
 }
 
 impl XsdClient {
-    pub fn new() -> Result<XsdClient, XsdBusError> {
+    pub fn open() -> Result<XsdClient, XsdBusError> {
         let socket = XsdSocket::dial()?;
         Ok(XsdClient { socket })
     }
@@ -55,6 +55,13 @@ impl XsdClient {
         let tx = response.parse_string()?.parse::<u32>()?;
         Ok(XsdTransaction { client: self, tx })
     }
+
+    pub fn get_domain_path(&mut self, domid: u32) -> Result<String, XsdBusError> {
+        let response =
+            self.socket
+                .send_single(0, XSD_GET_DOMAIN_PATH, domid.to_string().as_str())?;
+        response.parse_string()
+    }
 }
 
 pub struct XsdTransaction<'a> {