Started custom errors

Started adding custom errors. Still need to figure out how to chain errors.

src/errors.rs

@@ -0,0 +1,36 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub struct RegistrationError {
+    pub details: String
+}
+
+impl RegistrationError {
+    pub fn new(msg: &str) -> RegistrationError {
+        RegistrationError{details: msg.to_string()}
+    }
+}
+
+impl fmt::Display for RegistrationError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.details)
+    }
+}
+
+#[derive(Debug)]
+pub struct SerialError {
+    pub details: String
+}
+
+impl SerialError {
+    pub fn new(msg: &str) -> SerialError {
+        SerialError{details: msg.to_string()}
+    }
+}
+
+impl fmt::Display for SerialError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.details)
+    }
+}
+

src/main.rs

@@ -1,59 +1,9 @@
-use std::error::Error;
+mod errors;
+mod register;
 
-use rustbus::{RpcConn, MessageBuilder, client_conn::Timeout, params::Container};
-use rustbus::params::{Param, Base};
-
-fn main() -> Result<(), Box<dyn Error>> {
-    println!("Serial: {:?}", get_serial_number()?);
-    Ok(())
-}
-
-fn get_serial_number() -> Result<String, Box<dyn Error>> {
-    let mut rpc_con = match RpcConn::system_conn(Timeout::Infinite) {
-        Ok(rpc_con) => rpc_con,
-        Err(e) => panic!(e),
-    };
-
-
-    let mut sig = MessageBuilder::new()
-        .call("Get".into())
-        .on("/xyz/openbmc_project/inventory/system".into())
-        .with_interface("org.freedesktop.DBus.Properties".into())
-        .at("xyz.openbmc_project.Inventory.Manager".into())
-        .build();
-
-    // Additional params to retrieve the AssetTag properties.
-    sig.body.push_param2(
-        String::from("xyz.openbmc_project.Inventory.Decorator.AssetTag").as_str(),
-        String::from("AssetTag").as_str())
-        .expect("Unable to push_param2");
-    let serial = match rpc_con.send_message(&mut sig, Timeout::Infinite){
-        Ok(serial) => serial,
-        Err(e) => panic!(e),
-    };
-    let resp = match rpc_con.wait_response(serial, Timeout::Infinite){
-        Ok(resp) => resp,
-        Err(e) => panic!(e),
+fn main() {
+    match register::register_bmc() {
+        Ok(()) => println!("Registered!"),
+        Err(e) => println!("Unable to register: {:?}", e),
     };
-
-    let message = match resp.unmarshall_all(){
-        Ok(message) => message,
-        Err(e) => panic!(e),
-    };
-
-    let first_param = &message.params[0];
-
-
-    // This is super ugly, need to figure out how to improve
-    if let Param::Container(v) = first_param {
-        if let Container::Variant(x) = v {
-            if let Param::Base(y) = &x.value {
-                if let Base::String(z) = &y {
-                    return Ok(z.to_string());
-                }
-            }
-        }
-    }
-
-    panic!("Unable to parse serial");
 }

src/register.rs

@@ -0,0 +1,76 @@
+use rustbus::{RpcConn, MessageBuilder, client_conn::Timeout, params::Container};
+use rustbus::params::{Param, Base};
+
+use crate::errors::{RegistrationError, SerialError};
+
+pub fn register_bmc() -> Result<(), RegistrationError> {
+    let mut conn = match openconn() {
+        Ok(conn) => conn,
+        Err(_) => return Err(RegistrationError::new("Unable to open connection.")),
+    };
+
+    let serial = match get_serial_number(&mut conn) {
+        Ok(serial) => serial,
+        Err(_) => return Err(RegistrationError::new("Unable to read serial number.")),
+    };
+    println!("{:?}", serial);
+
+    Ok(())
+
+}
+
+fn openconn() -> Result<RpcConn, rustbus::client_conn::Error> {
+    match RpcConn::system_conn(Timeout::Infinite) {
+        Ok(rpc_conn) => return Ok(rpc_conn),
+        Err(e) => return Err(e),
+    };
+}
+
+fn get_serial_number(rpc_conn: &mut RpcConn) -> Result<String, SerialError> {
+
+
+    let mut sig = MessageBuilder::new()
+        .call("Get".into())
+        .on("/xyz/openbmc_project/inventory/system".into())
+        .with_interface("org.freedesktop.DBus.Properties".into())
+        .at("xyz.openbmc_project.Inventory.Manager".into())
+        .build();
+
+    // Additional params to retrieve the AssetTag properties.
+    match sig.body.push_param2(
+        String::from("xyz.openbmc_project.Inventory.Decorator.AssetTag").as_str(),
+        String::from("AssetTag").as_str()) {
+            Ok(()) => {},
+            Err(_) => return Err(SerialError::new("Unable to push params.")),
+    };
+
+    let serial = match rpc_conn.send_message(&mut sig, Timeout::Infinite){
+        Ok(serial) => serial,
+        Err(_) => return Err(SerialError::new("Unable to send message to bus.")),
+    };
+    let resp = match rpc_conn.wait_response(serial, Timeout::Infinite){
+        Ok(resp) => resp,
+        Err(_) => return Err(SerialError::new("Never got a response from bus.")),
+    };
+
+    let message = match resp.unmarshall_all(){
+        Ok(message) => message,
+        Err(_) => return Err(SerialError::new("Unable to unmarshall message")),
+    };
+
+    let first_param = &message.params[0];
+
+
+    // This is super ugly, need to figure out how to improve
+    if let Param::Container(v) = first_param {
+        if let Container::Variant(x) = v {
+            if let Param::Base(y) = &x.value {
+                if let Base::String(z) = &y {
+                    return Ok(z.to_string());
+                }
+            }
+        }
+    }
+
+    Err(SerialError::new("Unable to parse serial"))
+}