feat: add log-server (ring buffer) and permission-manager (grant/revoke/check) system servers

crates/servers/log-server/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "log-server"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+types = { workspace = true }
+server-framework = { workspace = true }

crates/servers/log-server/src/lib.rs

@@ -0,0 +1,8 @@
+#![no_std]
+
+pub mod protocol;
+pub mod server;
+
+#[cfg(test)]
+#[path = "tests/mod.rs"]
+mod tests;

crates/servers/log-server/src/protocol.rs

@@ -0,0 +1,99 @@
+use server_framework::{Decode, Encode};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum LogLevel {
+    Error,
+    Warn,
+    Info,
+    Debug,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum LogRequest {
+    Write { level: LogLevel, tag: u16, payload: usize },
+    GetCount,
+    GetEntry { index: usize },
+}
+
+#[derive(Debug, PartialEq)]
+pub enum LogResponse {
+    Ok,
+    Count(usize),
+    Entry { level: LogLevel, tag: u16, payload: usize },
+    NotFound,
+}
+
+fn encode_level(level: LogLevel) -> usize {
+    match level {
+        LogLevel::Error => 0,
+        LogLevel::Warn => 1,
+        LogLevel::Info => 2,
+        LogLevel::Debug => 3,
+    }
+}
+
+fn decode_level(v: usize) -> Option<LogLevel> {
+    match v {
+        0 => Some(LogLevel::Error),
+        1 => Some(LogLevel::Warn),
+        2 => Some(LogLevel::Info),
+        3 => Some(LogLevel::Debug),
+        _ => None,
+    }
+}
+
+impl Encode for LogRequest {
+    fn encode(&self) -> [usize; 4] {
+        match self {
+            LogRequest::Write { level, tag, payload } => {
+                [0, encode_level(*level) | ((*tag as usize) << 8), *payload, 0]
+            }
+            LogRequest::GetCount => [1, 0, 0, 0],
+            LogRequest::GetEntry { index } => [2, *index, 0, 0],
+        }
+    }
+}
+
+impl Decode for LogRequest {
+    fn decode(words: [usize; 4]) -> Option<Self> {
+        match words[0] {
+            0 => {
+                let level = decode_level(words[1] & 0xFF)?;
+                let tag = ((words[1] >> 8) & 0xFFFF) as u16;
+                Some(LogRequest::Write { level, tag, payload: words[2] })
+            }
+            1 => Some(LogRequest::GetCount),
+            2 => Some(LogRequest::GetEntry { index: words[1] }),
+            _ => None,
+        }
+    }
+}
+
+impl Encode for LogResponse {
+    fn encode(&self) -> [usize; 4] {
+        match self {
+            LogResponse::Ok => [0, 0, 0, 0],
+            LogResponse::Count(n) => [1, *n, 0, 0],
+            LogResponse::Entry { level, tag, payload } => {
+                [2, encode_level(*level) | ((*tag as usize) << 8), *payload, 0]
+            }
+            LogResponse::NotFound => [3, 0, 0, 0],
+        }
+    }
+}
+
+impl Decode for LogResponse {
+    fn decode(words: [usize; 4]) -> Option<Self> {
+        match words[0] {
+            0 => Some(LogResponse::Ok),
+            1 => Some(LogResponse::Count(words[1])),
+            2 => {
+                let level = decode_level(words[1] & 0xFF)?;
+                let tag = ((words[1] >> 8) & 0xFFFF) as u16;
+                Some(LogResponse::Entry { level, tag, payload: words[2] })
+            }
+            3 => Some(LogResponse::NotFound),
+            _ => None,
+        }
+    }
+}

crates/servers/log-server/src/server.rs

@@ -0,0 +1,68 @@
+use server_framework::Server;
+
+use crate::protocol::{LogLevel, LogRequest, LogResponse};
+
+const MAX_ENTRIES: usize = 128;
+
+struct LogEntry {
+    level: LogLevel,
+    tag: u16,
+    payload: usize,
+}
+
+pub struct LogServer {
+    entries: [Option<LogEntry>; MAX_ENTRIES],
+    count: usize,
+    write_pos: usize,
+}
+
+impl LogServer {
+    pub fn new() -> Self {
+        Self {
+            entries: [const { None }; MAX_ENTRIES],
+            count: 0,
+            write_pos: 0,
+        }
+    }
+
+    pub fn count(&self) -> usize {
+        self.count
+    }
+}
+
+impl Server for LogServer {
+    type Request = LogRequest;
+    type Response = LogResponse;
+
+    fn handle(&mut self, request: LogRequest) -> LogResponse {
+        match request {
+            LogRequest::Write { level, tag, payload } => {
+                self.entries[self.write_pos] = Some(LogEntry { level, tag, payload });
+                self.write_pos = (self.write_pos + 1) % MAX_ENTRIES;
+                if self.count < MAX_ENTRIES {
+                    self.count += 1;
+                }
+                LogResponse::Ok
+            }
+            LogRequest::GetCount => LogResponse::Count(self.count),
+            LogRequest::GetEntry { index } => {
+                if index >= self.count {
+                    return LogResponse::NotFound;
+                }
+                let actual = if self.count < MAX_ENTRIES {
+                    index
+                } else {
+                    (self.write_pos + index) % MAX_ENTRIES
+                };
+                match &self.entries[actual] {
+                    Some(entry) => LogResponse::Entry {
+                        level: entry.level,
+                        tag: entry.tag,
+                        payload: entry.payload,
+                    },
+                    None => LogResponse::NotFound,
+                }
+            }
+        }
+    }
+}

crates/servers/log-server/src/tests/mod.rs

@@ -0,0 +1,2 @@
+mod protocol;
+mod server;

crates/servers/log-server/src/tests/protocol.rs

@@ -0,0 +1,39 @@
+use crate::protocol::*;
+use server_framework::{Decode, Encode};
+
+#[test]
+fn write_request_roundtrip() {
+    let req = LogRequest::Write { level: LogLevel::Error, tag: 42, payload: 0xDEAD };
+    assert_eq!(LogRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn get_count_roundtrip() {
+    let req = LogRequest::GetCount;
+    assert_eq!(LogRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn get_entry_roundtrip() {
+    let req = LogRequest::GetEntry { index: 7 };
+    assert_eq!(LogRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn entry_response_roundtrip() {
+    let resp = LogResponse::Entry { level: LogLevel::Warn, tag: 10, payload: 123 };
+    assert_eq!(LogResponse::decode(resp.encode()), Some(resp));
+}
+
+#[test]
+fn all_levels_roundtrip() {
+    for level in [LogLevel::Error, LogLevel::Warn, LogLevel::Info, LogLevel::Debug] {
+        let req = LogRequest::Write { level, tag: 0, payload: 0 };
+        assert_eq!(LogRequest::decode(req.encode()), Some(req));
+    }
+}
+
+#[test]
+fn invalid_request_returns_none() {
+    assert!(LogRequest::decode([99, 0, 0, 0]).is_none());
+}

crates/servers/log-server/src/tests/server.rs

@@ -0,0 +1,43 @@
+use crate::protocol::*;
+use crate::server::LogServer;
+use server_framework::Server;
+
+#[test]
+fn empty_server_has_zero_count() {
+    let mut server = LogServer::new();
+    let resp = server.handle(LogRequest::GetCount);
+    assert_eq!(resp, LogResponse::Count(0));
+}
+
+#[test]
+fn write_increments_count() {
+    let mut server = LogServer::new();
+    server.handle(LogRequest::Write { level: LogLevel::Info, tag: 0, payload: 1 });
+    server.handle(LogRequest::Write { level: LogLevel::Info, tag: 0, payload: 2 });
+    let resp = server.handle(LogRequest::GetCount);
+    assert_eq!(resp, LogResponse::Count(2));
+}
+
+#[test]
+fn get_entry_returns_written_data() {
+    let mut server = LogServer::new();
+    server.handle(LogRequest::Write { level: LogLevel::Error, tag: 5, payload: 0xBEEF });
+    let resp = server.handle(LogRequest::GetEntry { index: 0 });
+    assert_eq!(resp, LogResponse::Entry { level: LogLevel::Error, tag: 5, payload: 0xBEEF });
+}
+
+#[test]
+fn get_entry_out_of_range_returns_not_found() {
+    let mut server = LogServer::new();
+    let resp = server.handle(LogRequest::GetEntry { index: 0 });
+    assert_eq!(resp, LogResponse::NotFound);
+}
+
+#[test]
+fn ring_buffer_wraps() {
+    let mut server = LogServer::new();
+    for i in 0..200 {
+        server.handle(LogRequest::Write { level: LogLevel::Debug, tag: 0, payload: i });
+    }
+    assert_eq!(server.count(), 128);
+}

crates/servers/permission-manager/Cargo.toml

@@ -4,3 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+types = { workspace = true }
+server-framework = { workspace = true }

crates/servers/permission-manager/src/lib.rs

@@ -1,14 +1,8 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
+#![no_std]
+
+pub mod protocol;
+pub mod server;
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+#[path = "tests/mod.rs"]
+mod tests;

crates/servers/permission-manager/src/protocol.rs

@@ -0,0 +1,127 @@
+use server_framework::{Decode, Encode};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CapabilityKind {
+    Display,
+    Input,
+    AudioPlayback,
+    AudioCapture,
+    Camera,
+    Storage,
+    Network,
+    Gps,
+    Bluetooth,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum PermissionRequest {
+    RequestCapability { process: u16, kind: CapabilityKind },
+    RevokeCapability { process: u16, kind: CapabilityKind },
+    CheckCapability { process: u16, kind: CapabilityKind },
+    ListGranted { process: u16 },
+}
+
+#[derive(Debug, PartialEq)]
+pub enum PermissionResponse {
+    Granted,
+    Denied,
+    Revoked,
+    HasCapability(bool),
+    GrantedList(u16),
+}
+
+fn encode_kind(kind: CapabilityKind) -> usize {
+    match kind {
+        CapabilityKind::Display => 0,
+        CapabilityKind::Input => 1,
+        CapabilityKind::AudioPlayback => 2,
+        CapabilityKind::AudioCapture => 3,
+        CapabilityKind::Camera => 4,
+        CapabilityKind::Storage => 5,
+        CapabilityKind::Network => 6,
+        CapabilityKind::Gps => 7,
+        CapabilityKind::Bluetooth => 8,
+    }
+}
+
+fn decode_kind(v: usize) -> Option<CapabilityKind> {
+    match v {
+        0 => Some(CapabilityKind::Display),
+        1 => Some(CapabilityKind::Input),
+        2 => Some(CapabilityKind::AudioPlayback),
+        3 => Some(CapabilityKind::AudioCapture),
+        4 => Some(CapabilityKind::Camera),
+        5 => Some(CapabilityKind::Storage),
+        6 => Some(CapabilityKind::Network),
+        7 => Some(CapabilityKind::Gps),
+        8 => Some(CapabilityKind::Bluetooth),
+        _ => None,
+    }
+}
+
+impl Encode for PermissionRequest {
+    fn encode(&self) -> [usize; 4] {
+        match self {
+            PermissionRequest::RequestCapability { process, kind } => {
+                [0, *process as usize, encode_kind(*kind), 0]
+            }
+            PermissionRequest::RevokeCapability { process, kind } => {
+                [1, *process as usize, encode_kind(*kind), 0]
+            }
+            PermissionRequest::CheckCapability { process, kind } => {
+                [2, *process as usize, encode_kind(*kind), 0]
+            }
+            PermissionRequest::ListGranted { process } => {
+                [3, *process as usize, 0, 0]
+            }
+        }
+    }
+}
+
+impl Decode for PermissionRequest {
+    fn decode(words: [usize; 4]) -> Option<Self> {
+        match words[0] {
+            0 => Some(PermissionRequest::RequestCapability {
+                process: words[1] as u16,
+                kind: decode_kind(words[2])?,
+            }),
+            1 => Some(PermissionRequest::RevokeCapability {
+                process: words[1] as u16,
+                kind: decode_kind(words[2])?,
+            }),
+            2 => Some(PermissionRequest::CheckCapability {
+                process: words[1] as u16,
+                kind: decode_kind(words[2])?,
+            }),
+            3 => Some(PermissionRequest::ListGranted {
+                process: words[1] as u16,
+            }),
+            _ => None,
+        }
+    }
+}
+
+impl Encode for PermissionResponse {
+    fn encode(&self) -> [usize; 4] {
+        match self {
+            PermissionResponse::Granted => [0, 0, 0, 0],
+            PermissionResponse::Denied => [1, 0, 0, 0],
+            PermissionResponse::Revoked => [2, 0, 0, 0],
+            PermissionResponse::HasCapability(has) => [3, *has as usize, 0, 0],
+            PermissionResponse::GrantedList(bits) => [4, *bits as usize, 0, 0],
+        }
+    }
+}
+
+impl Decode for PermissionResponse {
+    fn decode(words: [usize; 4]) -> Option<Self> {
+        match words[0] {
+            0 => Some(PermissionResponse::Granted),
+            1 => Some(PermissionResponse::Denied),
+            2 => Some(PermissionResponse::Revoked),
+            3 => Some(PermissionResponse::HasCapability(words[1] != 0)),
+            4 => Some(PermissionResponse::GrantedList(words[1] as u16)),
+            _ => None,
+        }
+    }
+}

crates/servers/permission-manager/src/server.rs

@@ -0,0 +1,82 @@
+use server_framework::Server;
+
+use crate::protocol::{CapabilityKind, PermissionRequest, PermissionResponse};
+
+const MAX_PROCESSES: usize = 64;
+const NUM_KINDS: usize = 9;
+
+pub struct PermissionManager {
+    grants: [[bool; NUM_KINDS]; MAX_PROCESSES],
+}
+
+impl PermissionManager {
+    pub fn new() -> Self {
+        Self {
+            grants: [[false; NUM_KINDS]; MAX_PROCESSES],
+        }
+    }
+
+    fn kind_index(kind: CapabilityKind) -> usize {
+        match kind {
+            CapabilityKind::Display => 0,
+            CapabilityKind::Input => 1,
+            CapabilityKind::AudioPlayback => 2,
+            CapabilityKind::AudioCapture => 3,
+            CapabilityKind::Camera => 4,
+            CapabilityKind::Storage => 5,
+            CapabilityKind::Network => 6,
+            CapabilityKind::Gps => 7,
+            CapabilityKind::Bluetooth => 8,
+        }
+    }
+
+    fn granted_bits(&self, process: u16) -> u16 {
+        let idx = process as usize;
+        if idx >= MAX_PROCESSES {
+            return 0;
+        }
+        let mut bits = 0u16;
+        for i in 0..NUM_KINDS {
+            if self.grants[idx][i] {
+                bits |= 1 << i;
+            }
+        }
+        bits
+    }
+}
+
+impl Server for PermissionManager {
+    type Request = PermissionRequest;
+    type Response = PermissionResponse;
+
+    fn handle(&mut self, request: PermissionRequest) -> PermissionResponse {
+        match request {
+            PermissionRequest::RequestCapability { process, kind } => {
+                let idx = process as usize;
+                if idx >= MAX_PROCESSES {
+                    return PermissionResponse::Denied;
+                }
+                self.grants[idx][Self::kind_index(kind)] = true;
+                PermissionResponse::Granted
+            }
+            PermissionRequest::RevokeCapability { process, kind } => {
+                let idx = process as usize;
+                if idx >= MAX_PROCESSES {
+                    return PermissionResponse::Denied;
+                }
+                self.grants[idx][Self::kind_index(kind)] = false;
+                PermissionResponse::Revoked
+            }
+            PermissionRequest::CheckCapability { process, kind } => {
+                let idx = process as usize;
+                if idx >= MAX_PROCESSES {
+                    return PermissionResponse::HasCapability(false);
+                }
+                PermissionResponse::HasCapability(self.grants[idx][Self::kind_index(kind)])
+            }
+            PermissionRequest::ListGranted { process } => {
+                PermissionResponse::GrantedList(self.granted_bits(process))
+            }
+        }
+    }
+}

crates/servers/permission-manager/src/tests/mod.rs

@@ -0,0 +1,2 @@
+mod protocol;
+mod server;

crates/servers/permission-manager/src/tests/protocol.rs

@@ -0,0 +1,59 @@
+use crate::protocol::*;
+use server_framework::{Decode, Encode};
+
+#[test]
+fn request_capability_roundtrip() {
+    let req = PermissionRequest::RequestCapability { process: 5, kind: CapabilityKind::Camera };
+    assert_eq!(PermissionRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn revoke_capability_roundtrip() {
+    let req = PermissionRequest::RevokeCapability { process: 3, kind: CapabilityKind::Network };
+    assert_eq!(PermissionRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn check_capability_roundtrip() {
+    let req = PermissionRequest::CheckCapability { process: 1, kind: CapabilityKind::Storage };
+    assert_eq!(PermissionRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn list_granted_roundtrip() {
+    let req = PermissionRequest::ListGranted { process: 7 };
+    assert_eq!(PermissionRequest::decode(req.encode()), Some(req));
+}
+
+#[test]
+fn all_kinds_roundtrip() {
+    let kinds = [
+        CapabilityKind::Display, CapabilityKind::Input, CapabilityKind::AudioPlayback,
+        CapabilityKind::AudioCapture, CapabilityKind::Camera, CapabilityKind::Storage,
+        CapabilityKind::Network, CapabilityKind::Gps, CapabilityKind::Bluetooth,
+    ];
+    for kind in kinds {
+        let req = PermissionRequest::RequestCapability { process: 0, kind };
+        assert_eq!(PermissionRequest::decode(req.encode()), Some(req));
+    }
+}
+
+#[test]
+fn response_roundtrips() {
+    let responses = [
+        PermissionResponse::Granted,
+        PermissionResponse::Denied,
+        PermissionResponse::Revoked,
+        PermissionResponse::HasCapability(true),
+        PermissionResponse::HasCapability(false),
+        PermissionResponse::GrantedList(0b101),
+    ];
+    for resp in responses {
+        assert_eq!(PermissionResponse::decode(resp.encode()), Some(resp));
+    }
+}
+
+#[test]
+fn invalid_request_returns_none() {
+    assert!(PermissionRequest::decode([99, 0, 0, 0]).is_none());
+}

crates/servers/permission-manager/src/tests/server.rs

@@ -0,0 +1,85 @@
+use crate::protocol::*;
+use crate::server::PermissionManager;
+use server_framework::Server;
+
+#[test]
+fn new_manager_has_no_grants() {
+    let mut mgr = PermissionManager::new();
+    let resp = mgr.handle(PermissionRequest::CheckCapability {
+        process: 0,
+        kind: CapabilityKind::Camera,
+    });
+    assert_eq!(resp, PermissionResponse::HasCapability(false));
+}
+
+#[test]
+fn grant_then_check() {
+    let mut mgr = PermissionManager::new();
+    mgr.handle(PermissionRequest::RequestCapability {
+        process: 1,
+        kind: CapabilityKind::Network,
+    });
+    let resp = mgr.handle(PermissionRequest::CheckCapability {
+        process: 1,
+        kind: CapabilityKind::Network,
+    });
+    assert_eq!(resp, PermissionResponse::HasCapability(true));
+}
+
+#[test]
+fn grant_does_not_affect_other_process() {
+    let mut mgr = PermissionManager::new();
+    mgr.handle(PermissionRequest::RequestCapability {
+        process: 1,
+        kind: CapabilityKind::Camera,
+    });
+    let resp = mgr.handle(PermissionRequest::CheckCapability {
+        process: 2,
+        kind: CapabilityKind::Camera,
+    });
+    assert_eq!(resp, PermissionResponse::HasCapability(false));
+}
+
+#[test]
+fn revoke_removes_grant() {
+    let mut mgr = PermissionManager::new();
+    mgr.handle(PermissionRequest::RequestCapability {
+        process: 0,
+        kind: CapabilityKind::Storage,
+    });
+    mgr.handle(PermissionRequest::RevokeCapability {
+        process: 0,
+        kind: CapabilityKind::Storage,
+    });
+    let resp = mgr.handle(PermissionRequest::CheckCapability {
+        process: 0,
+        kind: CapabilityKind::Storage,
+    });
+    assert_eq!(resp, PermissionResponse::HasCapability(false));
+}
+
+#[test]
+fn list_granted_returns_bitfield() {
+    let mut mgr = PermissionManager::new();
+    mgr.handle(PermissionRequest::RequestCapability {
+        process: 0,
+        kind: CapabilityKind::Display,
+    });
+    mgr.handle(PermissionRequest::RequestCapability {
+        process: 0,
+        kind: CapabilityKind::Network,
+    });
+    let resp = mgr.handle(PermissionRequest::ListGranted { process: 0 });
+    // Display=bit 0, Network=bit 6 → 0b1000001 = 65
+    assert_eq!(resp, PermissionResponse::GrantedList(0b1000001));
+}
+
+#[test]
+fn out_of_range_process_denied() {
+    let mut mgr = PermissionManager::new();
+    let resp = mgr.handle(PermissionRequest::RequestCapability {
+        process: 999,
+        kind: CapabilityKind::Camera,
+    });
+    assert_eq!(resp, PermissionResponse::Denied);
+}