Showcase version commit

Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "bffh"
+name = "diflouroborane"
 version = "0.1.0"
 authors = ["Gregor Reitzenstein <me@dequbed.space>"]
 edition = "2018"

src/access.rs

@@ -5,37 +5,50 @@ use slog::Logger;
 
 use casbin::prelude::*;
 
-use super::config::Config;
-
 use futures_signals::signal::Mutable;
 
 use crate::api::api;
+use crate::config::Config;
 use crate::auth::Authentication;
 use crate::error::Result;
 
+use std::rc::Rc;
+use async_std::sync::{Arc, RwLock};
+
+use std::ops::Deref;
+
+pub struct PermissionsProvider {
+    log: Logger,
+    pdb: Enforcer,
+}
+
+impl PermissionsProvider {
+    pub fn new(log: Logger, pdb: Enforcer) -> Self {
+        Self { log, pdb }
+    }
+
+    pub fn enforce(&self, actor: &str, object: &str, action: &str) -> Result<bool> {
+        let b = self.pdb.enforce(vec![actor, object, action])?;
+        Ok(b)
+    }
+}
+
 #[derive(Clone)]
 pub struct Permissions {
-    log: Logger,
-    pdb: Mutable<Enforcer>,
-    auth: Authentication,
+    inner: Arc<RwLock<PermissionsProvider>>,
+    auth: Rc<Authentication>,
 }
 
 impl Permissions {
-    pub fn new(log: Logger, pdb: Mutable<Enforcer>, auth: Authentication) -> Self {
-        Self { log, pdb, auth }
+    pub fn new(inner: Arc<RwLock<PermissionsProvider>>, auth: Rc<Authentication>) -> Self {
+        Self { inner, auth }
     }
 
-    pub fn enforce(&self, object: &str, action: &str) -> bool {
-        if let Some(actor) = self.auth.get_authzid() {
-            trace!(self.log, "Checking permission {} for {} on {}", action, actor, object);
-            let r = self.pdb.lock_ref().enforce(vec![&actor,object,action]).unwrap();
-            if !r {
-                info!(self.log, "Failed permission {} for {} on {}", action, actor, object);
-            }
-            return r;
+    pub async fn enforce(&self, object: &str, action: &str) -> Result<bool> {
+        if let Some(actor) = self.auth.state.read().await.deref() {
+            self.inner.read().await.enforce(&actor, object, action)
         } else {
-            info!(self.log, "Attempted anonymous access: {} on {}", action, object);
-            false
+            Ok(false)
         }
     }
 }
@@ -45,11 +58,11 @@ impl api::permissions::Server for Permissions {
 }
 
 /// This line documents init
-pub async fn init(config: &Config) -> std::result::Result<Enforcer, Box<dyn std::error::Error>> {
+pub async fn init(log: Logger, config: &Config) -> std::result::Result<PermissionsProvider, Box<dyn std::error::Error>> {
     let model = Model::from_file(config.access.model.clone()).await?;
     let adapter = Box::new(FileAdapter::new(config.access.policy.clone()));
 
     let e = Enforcer::new(model, adapter).await?;
 
-    return Ok(e);
+    return Ok(PermissionsProvider::new(log, e));
 }

src/api.rs

@@ -7,13 +7,20 @@ pub mod api {
 use std::default::Default;
 use async_std::net::TcpStream;
 
+use futures::task::Spawn;
+use futures::FutureExt;
 use futures_signals::signal::Mutable;
 use casbin::Enforcer;
 use casbin::MgmtApi;
 
-use crate::machine::Machines;
-use crate::auth::Authentication;
-use crate::access::Permissions;
+use slog::Logger;
+
+use std::rc::Rc;
+use async_std::sync::{Arc, RwLock};
+
+use crate::machine::{MachinesProvider, Machines};
+use crate::auth::{AuthenticationProvider, Authentication};
+use crate::access::{PermissionsProvider, Permissions};
 
 use capnp::{Error};
 use capnp::capability::Promise;
@@ -21,35 +28,76 @@ use capnp_rpc::RpcSystem;
 use capnp_rpc::twoparty::VatNetwork;
 use capnp_rpc::rpc_twoparty_capnp::Side;
 
+use std::ops::Deref;
+
 use api::diflouroborane;
 
-pub fn init() {
+#[derive(Clone)]
+pub struct API<S> {
+    auth: Arc<RwLock<AuthenticationProvider>>,
+    perm: Arc<RwLock<PermissionsProvider>>,
+    mach: Arc<RwLock<MachinesProvider>>,
+
+    spawner: S,
+}
+impl<S: Spawn> API<S> {
+    pub fn new(auth: AuthenticationProvider, 
+       perm: PermissionsProvider,
+       mach: MachinesProvider,
+       spawner: S)
+        -> Self
+    {
+        let auth = Arc::new(RwLock::new(auth));
+        let perm = Arc::new(RwLock::new(perm));
+        let mach = Arc::new(RwLock::new(mach));
+
+        Self { auth, perm, mach, spawner }
+    }
+
+    pub fn into_connection(self) -> Bootstrap {
+        let auth = Rc::new(Authentication::new(self.auth));
+        let perm = Rc::new(Permissions::new(self.perm, auth.clone()));
+        let mach = Machines::new(self.mach, perm.clone());
+        Bootstrap {
+            auth: auth,
+            perm: perm,
+            mach: mach,
+        }
+    }
 }
 
-pub async fn process_socket(auth: Authentication, perm: Permissions, mach: Machines, socket: TcpStream) 
-    -> Result<(), Error> 
-{
-    let api = Api { auth, perm, mach };
-    let a = api::diflouroborane::ToClient::new(api).into_client::<capnp_rpc::Server>();
+pub async fn handle_connection<S: Spawn>(api: API<S>, log: Logger, socket: TcpStream) -> Result<(), Error> {
+    info!(log, "A new connection");
+    let client = api.into_connection();
+    let a = api::diflouroborane::ToClient::new(client).into_client::<capnp_rpc::Server>();
+
     let netw = VatNetwork::new(socket.clone(), socket, Side::Server, Default::default());
-    let rpc = RpcSystem::new(Box::new(netw), Some(a.clone().client));
-    rpc.await
+
+    let rpc = RpcSystem::new(Box::new(netw), Some(a.clone().client)).map(|_| ());
+
+    rpc.await;
+    
+    Ok(())
 }
 
-struct Api {
-    auth: Authentication,
-    perm: Permissions,
+/// Bootstrap capability of the Diflouroborane API
+///
+/// This is the starting point for any client connecting
+#[derive(Clone)]
+pub struct Bootstrap {
+    auth: Rc<Authentication>,
+    perm: Rc<Permissions>,
     mach: Machines,
 }
 
-impl diflouroborane::Server for Api {
+impl diflouroborane::Server for Bootstrap {
     fn authentication(&mut self,
         _params: diflouroborane::AuthenticationParams,
         mut results: diflouroborane::AuthenticationResults)
         -> Promise<(), Error>
     {
         let mut b = results.get();
-        let auth = api::authentication::ToClient::new(self.auth.clone()).into_client::<capnp_rpc::Server>();
+        let auth = api::authentication::ToClient::new(self.auth.deref().clone()).into_client::<capnp_rpc::Server>();
         b.set_auth(auth);
         Promise::ok(())
     }
@@ -59,9 +107,9 @@ impl diflouroborane::Server for Api {
         mut results: diflouroborane::PermissionsResults) 
         -> Promise<(), Error>
     {
-        let mut b = results.get();
-        let perm = api::permissions::ToClient::new(self.perm.clone()).into_client::<capnp_rpc::Server>();
-        b.set_perm(perm);
+        //let mut b = results.get();
+        //let perm = api::permissions::ToClient::new(self.perm).into_client::<capnp_rpc::Server>();
+        //b.set_perm(perm);
         Promise::ok(())
     }
 

src/auth.rs

@@ -11,6 +11,9 @@ use std::fs::File;
 use std::io::{Read, Write};
 use std::ops::Deref;
 
+use async_std::sync::{Arc, RwLock};
+use capnp::capability::Promise;
+
 use futures_signals::signal::Mutable;
 use casbin::{Enforcer, Model, FileAdapter};
 
@@ -133,24 +136,16 @@ impl AuthenticationProvider {
 
 #[derive(Clone)]
 pub struct Authentication {
-    state: Mutable<Option<String>>,
-    provider: Mutable<AuthenticationProvider>,
+    pub state: Arc<RwLock<Option<String>>>,
+    provider: Arc<RwLock<AuthenticationProvider>>,
 }
 impl Authentication {
-    pub fn new(provider: Mutable<AuthenticationProvider>) -> Self {
+    pub fn new(provider: Arc<RwLock<AuthenticationProvider>>) -> Self {
         Self {
-            state: Mutable::new(None),
+            state: Arc::new(RwLock::new(None)),
             provider: provider,
         }
     }
-
-    pub fn get_authzid(&self) -> Option<String> {
-        self.state.lock_ref().clone()
-    }
-
-    pub fn mechs(&self) -> Vec<&'static str> {
-        self.provider.lock_ref().mechs()
-    }
 }
 
 
@@ -162,15 +157,19 @@ impl api::authentication::Server for Authentication {
         mut results: api::authentication::AvailableMechanismsResults)
         -> ::capnp::capability::Promise<(), ::capnp::Error>
     {
-        let m = self.mechs();
-        let mut b = results.get()
-            .init_mechanisms(m.len() as u32);
-        for (i, mech) in m.iter().enumerate() {
-            let mut bldr = b.reborrow();
-            bldr.set(i as u32, mech);
-        }
+        let p = self.provider.clone();
+        let f = async move {
+            let m = p.read().await.mechs();
+            let mut b = results.get()
+                .init_mechanisms(m.len() as u32);
+            for (i, mech) in m.iter().enumerate() {
+                let mut bldr = b.reborrow();
+                bldr.set(i as u32, mech);
+            }
+            Ok(())
+        };
 
-        ::capnp::capability::Promise::ok(())
+        ::capnp::capability::Promise::from_future(f)
     }
 
     fn initialize_authentication(&mut self,
@@ -178,42 +177,47 @@ impl api::authentication::Server for Authentication {
         mut results: api::authentication::InitializeAuthenticationResults)
         -> ::capnp::capability::Promise<(), ::capnp::Error>
     {
-        let params = pry!(params.get());
-        let mechanism = pry!(params.get_mechanism());
-        match mechanism {
-            "PLAIN" => {
-                use api::authentication::maybe_data::Which;
+        let prov = self.provider.clone();
+        let stat = self.state.clone();
 
-                let data = pry!(params.get_initial_data());
-                if let Ok(Which::Some(data)) = data.which() {
-                    let data = pry!(data);
-                    if let Ok((b, name)) = self.provider.lock_ref().plain.step(data) {
+        Promise::from_future(async move {
+            let params = params.get()?;
+            let mechanism = params.get_mechanism()?;
 
-                        // If login was successful, also set the current authzid
-                        if b {
-                            self.state.lock_mut().replace(name.to_string());
+            match mechanism {
+                "PLAIN" => {
+                    use api::authentication::maybe_data::Which;
+
+                    let data = params.get_initial_data()?;
+                    if let Ok(Which::Some(data)) = data.which() {
+                        let data = data?;
+                        if let Ok((b, name)) = prov.read().await.plain.step(data) {
+                            // If login was successful set the authzid
+                            if b {
+                                stat.write().await.replace(name.to_string());
+                            }
+
+                            let outcome = Outcome::value(b);
+                            results
+                                .get()
+                                .init_response()
+                                .set_outcome(api::authentication::outcome::ToClient::new(outcome)
+                                    .into_client::<::capnp_rpc::Server>());
                         }
-
-                        let outcome = Outcome::value(b);
-                        results
-                            .get()
-                            .init_response()
-                            .set_outcome(api::authentication::outcome::ToClient::new(outcome)
-                                .into_client::<::capnp_rpc::Server>());
+                        Ok(())
+                    } else {
+                        Err(::capnp::Error::unimplemented(
+                            "SASL PLAIN requires initial data set".to_string()))
                     }
-                    ::capnp::capability::Promise::ok(())
-                } else {
-                    return
-                        ::capnp::capability::Promise::err(::capnp::Error::unimplemented(
-                        "SASL PLAIN requires initial data set".to_string()));
+                },
+                m => {
+                    Err(::capnp::Error::unimplemented(
+                            format!("SASL Mechanism {} is not implemented", m)
+                    ))
                 }
-            },
-            m => {
-                return
-                    ::capnp::capability::Promise::err(::capnp::Error::unimplemented(
-                    format!("SASL Mechanism {} is not implemented", m)));
+
             }
-        }
+        })
     }
 
     fn get_authzid(&mut self,
@@ -221,12 +225,18 @@ impl api::authentication::Server for Authentication {
         mut results: api::authentication::GetAuthzidResults)
         -> ::capnp::capability::Promise<(), ::capnp::Error>
     {
-        if let Some(zid) = self.state.lock_ref().deref() {
-            results.get().set_authzid(zid);
-        } else {
-            results.get().set_authzid("");
-        }
-        ::capnp::capability::Promise::ok(())
+        let state = self.state.clone();
+        let f = async move {
+            if let Some(zid) = state.read().await.deref() {
+                results.get().set_authzid(&zid);
+            } else {
+                results.get().set_authzid("");
+            }
+
+            Ok(())
+        };
+
+        Promise::from_future(f)
     }
 }
 

src/config.rs

@@ -1,25 +1,28 @@
 use std::str::FromStr;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use serde::{Serialize, Deserialize};
+use std::io::Read;
+use std::fs::File;
 
 use crate::error::Result;
 
-pub fn read() -> Result<Config> {
-    Ok(Config {
-        machinedb: PathBuf::from_str("/tmp/machines.db").unwrap(),
-        access: Access {
-            model: PathBuf::from_str("/tmp/model.conf").unwrap(),
-            policy: PathBuf::from_str("/tmp/policy.csv").unwrap(),
-        },
-        passdb: PathBuf::from_str("/tmp/passwd.db").unwrap(),
-    })
+use std::default::Default;
+
+pub fn read(path: &Path) -> Result<Config> {
+    let mut fp = File::open(path)?;
+    let mut contents = String::new();
+    fp.read_to_string(&mut contents)?;
+
+    let config = toml::from_str(&contents)?;
+    Ok(config)
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Config {
-    pub(crate) access: Access,
     pub machinedb: PathBuf,
     pub passdb: PathBuf,
+    pub(crate) access: Access,
+    pub listen: Box<[Listen]>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -27,3 +30,33 @@ pub struct Access {
     pub(crate) model: PathBuf,
     pub(crate) policy: PathBuf
 }
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Listen {
+    pub address: String,
+    pub port: Option<u16>,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Config {
+            machinedb: PathBuf::from_str("/tmp/machines.db").unwrap(),
+            access: Access {
+                model: PathBuf::from_str("/tmp/model.conf").unwrap(),
+                policy: PathBuf::from_str("/tmp/policy.csv").unwrap(),
+            },
+            passdb: PathBuf::from_str("/tmp/passwd.db").unwrap(),
+            listen: Box::new([Listen {
+                    address: "127.0.0.1".to_string(),
+                    port: Some(DEFAULT_PORT)
+                },
+                Listen {
+                    address: "::1".to_string(),
+                    port: Some(DEFAULT_PORT)
+            }]),
+        }
+    }
+}
+
+// The default port in the non-assignable i.e. free-use area
+pub const DEFAULT_PORT: u16 = 59661;

src/error.rs

@@ -9,6 +9,7 @@ pub enum Error {
     TomlSer(toml::ser::Error),
     SASL(SASLError),
     IO(io::Error),
+    Boxed(Box<dyn std::error::Error>),
 }
 
 impl From<SASLError> for Error {
@@ -35,4 +36,10 @@ impl From<toml::ser::Error> for Error {
     }
 }
 
+impl From<Box<dyn std::error::Error>> for Error {
+    fn from(e: Box<dyn std::error::Error>) -> Error {
+        Error::Boxed(e)
+    }
+}
+
 pub type Result<T> = std::result::Result<T, Error>;

src/log.rs

@@ -1,8 +1,9 @@
 use slog::{Drain, Logger};
 use slog_async;
 use slog_term::{TermDecorator, FullFormat};
+use crate::config::Config;
 
-pub fn init() -> Logger {
+pub fn init(_config: &Config) -> Logger {
     let decorator = TermDecorator::new().build();
     let drain = FullFormat::new(decorator).build().fuse();
     let drain = slog_async::Async::new(drain).build().fuse();

src/machine.rs

@@ -15,6 +15,9 @@ use crate::config::Config;
 use crate::api::api;
 use crate::access::Permissions;
 
+use std::rc::Rc;
+use async_std::sync::{Arc, RwLock};
+
 use capnp::capability::Promise;
 use capnp::Error;
 use capnp_rpc::Server;
@@ -32,16 +35,64 @@ pub enum Status {
     Blocked,
 }
 
-#[derive(Clone)]
-pub struct Machines {
+pub struct MachinesProvider {
     log: Logger,
-    mdb: Mutable<MachineDB>,
-    perm: Permissions
+    mdb: MachineDB,
 }
 
+impl MachinesProvider {
+    pub fn new(log: Logger, mdb: MachineDB) -> Self {
+        Self { log, mdb }
+    }
+
+    pub fn use_(&mut self, uuid: &Uuid) -> std::result::Result<(), capnp::Error> {
+        if let Some(m) = self.mdb.get_mut(uuid) {
+            match m.status {
+                Status::Free => {
+                    trace!(self.log, "Granted use on machine {}", uuid);
+
+                    m.status = Status::Occupied;
+
+                    Ok(())
+                },
+                Status::Occupied => {
+                    info!(self.log, "Attempted use on an occupied machine {}", uuid);
+                    Err(Error::failed("Machine is occupied".to_string()))
+                },
+                Status::Blocked => {
+                    info!(self.log, "Attempted use on a blocked machine {}", uuid);
+                    Err(Error::failed("Machine is blocked".to_string()))
+                }
+            }
+        } else {
+            info!(self.log, "Attempted use on invalid machine {}", uuid);
+            Err(Error::failed("No such machine".to_string()))
+        }
+    }
+
+    pub fn give_back(&mut self, uuid: &Uuid) -> std::result::Result<(), capnp::Error> {
+        if let Some(m) = self.mdb.get_mut(uuid) {
+            m.status = Status::Free;
+        } else {
+            warn!(self.log, "A giveback was issued for a unknown machine {}", uuid);
+        }
+
+        Ok(())
+    }
+
+    pub fn get_perm_req(&self, uuid: &Uuid) -> Option<String> {
+        self.mdb.get(uuid).map(|m| m.perm.clone())
+    }
+}
+
+#[derive(Clone)]
+pub struct Machines {
+    inner: Arc<RwLock<MachinesProvider>>,
+    perm: Rc<Permissions>,
+}
 impl Machines {
-    pub fn new(log: Logger, mdb: Mutable<MachineDB>, perm: Permissions) -> Self {
-        Self { log, mdb, perm }
+    pub fn new(inner: Arc<RwLock<MachinesProvider>>, perm: Rc<Permissions>) -> Self {
+        Self { inner, perm }
     }
 }
 impl api::machines::Server for Machines {
@@ -52,79 +103,95 @@ impl api::machines::Server for Machines {
     {
         let params = pry!(params.get());
         let uuid_s = pry!(params.get_uuid());
-
         let uuid = uuid_from_api(uuid_s);
 
-        let db = self.mdb.lock_ref();
+        // We need to copy the Arc here because we don't have access to it from within the closure
+        // witout moving it out of self.
+        let i = self.inner.clone();
+        let p = self.perm.clone();
 
-        if let Some(m) = db.get(&uuid) {
-            let manager = MachineManager::new(uuid, self.mdb.clone());
+        let f = async move {
+            // We only need a read lock at first there's no reason to aquire a write lock.
+            let i_lock = i.read().await;
 
-            if self.perm.enforce(&m.perm, "manage") {
-                let mut b = results.get();
-                let mngr = api::machines::manage::ToClient::new(manager).into_client::<Server>();
-                b.set_manage(mngr);
-                trace!(self.log, "Granted manage on machine {}", uuid);
-                Promise::ok(())
-            } else {
-                Promise::err(Error::failed("Permission denied".to_string()))
+            if let Some(ps) = i_lock.get_perm_req(&uuid) {
+                // drop the lock as soon as possible to prevent locking as much as possible
+                drop(i_lock);
+                if let Ok(true) = p.enforce(&ps, "manage").await {
+                    // We're here and have not returned an error yet - that means we're free to
+                    // send a successful manage back.
+                    let mut b = results.get();
+
+                    // Magic incantation to get a capability to send
+                    // Also since we move i in here we at this point *must* have dropped
+                    // all locks we may still have on it.
+                    b.set_manage(api::machines::give_back::ToClient::new(
+                            MachineManager::new(i, uuid)).into_client::<Server>());
+                }
             }
-        } else {
-            info!(self.log, "Attempted manage on invalid machine {}", uuid);
-            Promise::err(Error::failed("No such machine".to_string()))
-        }
+            Ok(())
+        };
+
+        Promise::from_future(f)
     }
 
     fn use_(&mut self,
         params: api::machines::UseParams,
         mut results: api::machines::UseResults)
-        -> Promise<(), Error>
+        -> Promise<(), capnp::Error>
     {
         let params = pry!(params.get());
         let uuid_s = pry!(params.get_uuid());
         let uuid = uuid_from_api(uuid_s);
 
-        let mdb = self.mdb.lock_ref();
-        if let Some(m) = mdb.get(&uuid) {
-            match m.status {
-                Status::Free => {
-                    trace!(self.log, "Granted use on machine {}", uuid);
+        // We need to copy the Arc here because we don't have access to it from within the closure
+        // witout moving it out of self.
+        let i = self.inner.clone();
+        let p = self.perm.clone();
 
+        let f = async move {
+            // We only need a read lock at first there's no reason to aquire a write lock.
+            let i_lock = i.read().await;
+
+            if let Some(ps) = i_lock.get_perm_req(&uuid) {
+                // drop the lock as soon as possible to prevent locking as much as possible
+                drop(i_lock);
+                if let Ok(true) = p.enforce(&ps, "write").await {
+                    {
+                        // If use_() returns an error that is our error. If it doesn't that means we can use
+                        // the machine
+                        // Using a subscope to again make the time the lock is valid as short as
+                        // possible. Less locking == more good
+                        let mut i_lock = i.write().await;
+                        i_lock.use_(&uuid)?;
+                    }
+
+                    // We're here and have not returned an error yet - that means we're free to
+                    // send a successful use back.
                     let mut b = results.get();
 
-                    let gb = api::machines::give_back::ToClient::new(
-                            GiveBack::new(self.log.new(o!()), uuid, self.mdb.clone())
-                        ).into_client::<Server>();
-
-                    b.set_giveback(gb);
-
-                    Promise::ok(())
-                },
-                Status::Occupied => {
-                    info!(self.log, "Attempted use on an occupied machine {}", uuid);
-                    Promise::err(Error::failed("Machine is occupied".to_string()))
-                },
-                Status::Blocked => {
-                    info!(self.log, "Attempted use on a blocked machine {}", uuid);
-                    Promise::err(Error::failed("Machine is blocked".to_string()))
+                    // Magic incantation to get a capability to send
+                    // Also since we move i in here we at this point *must* have dropped
+                    // all locks we may still have on it.
+                    b.set_giveback(api::machines::give_back::ToClient::new(
+                            GiveBack::new(i, uuid)).into_client::<Server>());
                 }
             }
-        } else {
-            info!(self.log, "Attempted use on invalid machine {}", uuid);
-            Promise::err(Error::failed("No such machine".to_string()))
-        }
+            Ok(())
+        };
+
+        Promise::from_future(f)
     }
 }
 
+#[derive(Clone)]
 pub struct GiveBack {
-    log: Logger,
-    mdb: Mutable<MachineDB>,
+    mdb: Arc<RwLock<MachinesProvider>>,
     uuid: Uuid,
 }
 impl GiveBack {
-    pub fn new(log: Logger, uuid: Uuid, mdb: Mutable<MachineDB>) -> Self {
-        trace!(log, "Giveback initialized for {}", uuid);
-        Self { log, mdb, uuid }
+    pub fn new(mdb: Arc<RwLock<MachinesProvider>>, uuid: Uuid) -> Self {
+        Self { mdb, uuid }
     }
 }
 
@@ -134,19 +201,16 @@ impl api::machines::give_back::Server for GiveBack {
         _results: api::machines::give_back::GivebackResults)
         -> Promise<(), Error>
     {
-        trace!(log, "Returning {}...", uuid);
-        let mut mdb = self.mdb.lock_mut();
-        if let Some(m) = mdb.get_mut(&self.uuid) {
-            m.status = Status::Free;
-        } else {
-            warn!(self.log, "A giveback was issued for a unknown machine {}", self.uuid);
-        }
+        let mdb = self.mdb.clone();
+        let uuid = self.uuid.clone();
+        let f = async move {
+            mdb.write().await.give_back(&uuid)
+        };
 
-        Promise::ok(())
+        Promise::from_future(f)
     }
 }
 
-// FIXME: Test this exhaustively!
 fn uuid_from_api(uuid: api::u_u_i_d::Reader) -> Uuid {
     let uuid0 = uuid.get_uuid0() as u128;
     let uuid1 = uuid.get_uuid1() as u128;
@@ -163,12 +227,12 @@ fn api_from_uuid(uuid: Uuid, mut wr: api::u_u_i_d::Builder) {
 
 #[derive(Clone)]
 pub struct MachineManager {
-    mdb: Mutable<MachineDB>,
+    mdb: Arc<RwLock<MachinesProvider>>,
     uuid: Uuid,
 }
 
 impl MachineManager {
-    pub fn new(uuid: Uuid, mdb: Mutable<MachineDB>) -> Self {
+    pub fn new(uuid: Uuid, mdb: Arc<RwLock<MachineDB>>) -> Self {
         Self { mdb, uuid }
     }
 }
@@ -222,16 +286,18 @@ impl Machine {
 
 pub type MachineDB = HashMap<Uuid, Machine>;
 
-pub fn init(config: &Config) -> Result<MachineDB> {
-    if config.machinedb.is_file() {
+pub async fn init(log: Logger, config: &Config) -> Result<MachinesProvider> {
+    let mdb = if config.machinedb.is_file() {
         let mut fp = File::open(&config.machinedb)?;
         let mut content = String::new();
         fp.read_to_string(&mut content)?;
         let map = toml::from_str(&content)?;
-        return Ok(map);
+        map
     } else {
-        return Ok(HashMap::new());
-    }
+        HashMap::new()
+    };
+
+    Ok(MachinesProvider::new(log, mdb))
 }
 
 pub fn save(config: &Config, mdb: &MachineDB) -> Result<()> {

src/main.rs

@@ -26,7 +26,7 @@ use futures::prelude::*;
 use futures::executor::{LocalPool, ThreadPool};
 use futures::compat::Stream01CompatExt;
 use futures::join;
-use futures::task::SpawnExt;
+use futures::task::{SpawnExt, LocalSpawn};
 
 use capnp_rpc::twoparty::{VatNetwork, VatId};
 use capnp_rpc::rpc_twoparty_capnp::Side;
@@ -43,6 +43,8 @@ use std::sync::Arc;
 
 use error::Error;
 
+use api::API;
+
 // Returning a `Result` from `main` allows us to use the `?` shorthand.
 // In the case of an Err it will be printed using `fmt::Debug`
 fn main() -> Result<(), Error> {
@@ -106,7 +108,7 @@ fn main() -> Result<(), Error> {
     // Start loading the machine database, authentication system and permission system
     // All of those get a custom logger so the source of a log message can be better traced and
     // filtered
-    let machinedb_f = machine::init(log.new(o!("system" => "machinedb")), &config);
+    let machinedb_f = machine::init(log.new(o!("system" => "machines")), &config);
     let permission_f = access::init(log.new(o!("system" => "permissions")), &config);
     let authentication_f = auth::init(log.new(o!("system" => "authentication")), config.clone());
 
@@ -132,14 +134,14 @@ fn main() -> Result<(), Error> {
             }
         }).collect();
 
-    let (mdb, pdb, auth) = exec.run_until(async {
+    let (mach, pdb, auth) = exec.run_until(async {
         // Rull all futures to completion in parallel.
         // This will block until all three are done starting up.
         join!(machinedb_f, permission_f, authentication_f)
     });
 
     // Error out if any of the subsystems failed to start.
-    let mdb = mdb?;
+    let mach = mach?;
     let pdb = pdb.unwrap();
     let auth = auth?;
 
@@ -157,6 +159,12 @@ fn main() -> Result<(), Error> {
             info!(stop_log.new(o!("system" => "threadpool")), "Stopping Thread <{}>", i)
         })
         .create()?;
+    let local_spawn = exec.spawner();
+
+
+    // The API has access to all subsystems it needs and the Threadpool as capability to spawn new
+    // tasks for CPU-intensive work
+    let api = API::new(auth, pdb, mach, pool);
 
     // Closure inefficiencies. Lucky cloning an Arc is pretty cheap.
     let inner_log = log.clone();
@@ -167,9 +175,6 @@ fn main() -> Result<(), Error> {
         let listeners = listeners_s.await;
         let incoming = stream::select_all(listeners.iter().map(|l| l.incoming()));
 
-        // Spawner is a handle to the shared ThreadPool forwarded into each connection
-        let spawner = pool.clone();
-
         // For each incoming connection start a new task to handle it and throw it on the thread
         // pool
         let handle_sockets = incoming.map(|socket| {
@@ -191,7 +196,7 @@ fn main() -> Result<(), Error> {
 
                     // We handle the error using map_err, `let _` is used to quiet the compiler
                     // warning
-                    let f = api::handle_connection(log.clone(), socket, spawner.clone())
+                    let f = api::handle_connection(api.clone(), log.clone(), socket)
                         .map_err(move |e| {
                             error!(log, "Error occured during protocol handling: {}", e);
                         })
@@ -199,7 +204,8 @@ fn main() -> Result<(), Error> {
                         .map(|_| ());
 
                     // In this case only the error is relevant since the Value is always ()
-                    if let Err(e) = pool.spawn(f) {
+                    // The future is Boxed to make it the `LocalFutureObj` that LocalSpawn expects
+                    if let Err(e) = local_spawn.spawn_local_obj(Box::new(f).into()) {
                         error!(elog, "Failed to spawn connection handler: {}", e);
                         // Failing to spawn a handler means we are most likely overloaded
                         return LoopResult::Overloaded;