syntax = "proto3";
option go_package = "github.com/coder/coder/v2/vpn";
option csharp_namespace = "Coder.Desktop.Vpn.Proto";

import "google/protobuf/timestamp.proto";
import "google/protobuf/duration.proto";

package vpn;

// The CoderVPN protocol operates over a bidirectional stream between a "manager" and a "tunnel."
// The manager is part of the Coder Desktop application and written in OS native code. It handles
// configuring the VPN and displaying status to the end user.  The tunnel is written in Go and
// handles operating the actual tunnel, including reading and writing packets, & communicating with
// the Coder server control plane.


// RPC allows a very simple unary request/response RPC mechanism.  The requester generates a unique
// msg_id which it sets on the request, the responder sets response_to that msg_id on the response
// message
message RPC {
	uint64 msg_id = 1;
	uint64 response_to = 2;
}

// ManagerMessage is a message from the manager (to the tunnel).
message ManagerMessage {
	RPC rpc = 1;
	oneof msg {
		GetPeerUpdate get_peer_update = 2;
		NetworkSettingsResponse network_settings = 3;
		StartRequest start = 4;
		StopRequest stop = 5;
	}
}

// TunnelMessage is a message from the tunnel (to the manager).
message TunnelMessage {
	RPC rpc = 1;
	oneof msg {
		Log log = 2;
		PeerUpdate peer_update = 3;
		NetworkSettingsRequest network_settings = 4;
		StartResponse start = 5;
		StopResponse stop = 6;
	}
}

// ClientMessage is a message from the client (to the service). Windows only.
message ClientMessage {
	RPC rpc = 1;
	oneof msg {
		StartRequest start = 2;
		StopRequest stop = 3;
		StatusRequest status = 4;
	}
}

// ServiceMessage is a message from the service (to the client). Windows only.
message ServiceMessage {
	RPC rpc = 1;
	oneof msg {
		StartResponse start = 2;
		StopResponse stop = 3;
		Status status = 4;                // either in reply to a StatusRequest or broadcasted
		StartProgress start_progress = 5; // broadcasted during startup (used exclusively by Windows)
	}
}

// Log is a log message generated by the tunnel.  The manager should log it to the system log. It is
// one-way tunnel -> manager with no response.
message Log {
	enum Level {
		// these are designed to match slog levels
		DEBUG = 0;
		INFO = 1;
		WARN = 2;
		ERROR = 3;
		CRITICAL = 4;
		FATAL = 5;
	}
	Level level = 1;

	string message = 2;
	repeated string logger_names = 3;

	message Field {
		string name = 1;
		string value = 2;
	}
	repeated Field fields = 4;
}

// GetPeerUpdate asks for a PeerUpdate with a full set of data.
message GetPeerUpdate {}

// PeerUpdate is an update about workspaces and agents connected via the tunnel. It is generated in
// response to GetPeerUpdate (which dumps the full set). It is also generated on any changes (not in
// response to any request).
message PeerUpdate {
	repeated Workspace upserted_workspaces = 1;
	repeated Agent upserted_agents = 2;
	repeated Workspace deleted_workspaces = 3;
	repeated Agent deleted_agents = 4;
}

message Workspace {
	bytes id = 1; // UUID
	string name = 2;

	enum Status {
		UNKNOWN = 0;
		PENDING = 1;
		STARTING = 2;
		RUNNING = 3;
		STOPPING = 4;
		STOPPED = 5;
		FAILED = 6;
		CANCELING = 7;
		CANCELED = 8;
		DELETING = 9;
		DELETED = 10;
	}
	Status status = 3;
}

message Agent {
	bytes id = 1; // UUID
	string name = 2;
	bytes workspace_id = 3; // UUID
	repeated string fqdn = 4;
	repeated string ip_addrs = 5;
	// last_handshake is the primary indicator of whether we are connected to a peer. Zero value or
	// anything longer than 5 minutes ago means there is a problem.
	google.protobuf.Timestamp last_handshake = 6;
	// If unset, a successful ping has not yet been made.
	optional LastPing last_ping = 7;
}

message LastPing {
	// latency is the RTT of the ping to the agent.
	google.protobuf.Duration latency = 1;
	// did_p2p indicates whether the ping was sent P2P, or over DERP.
	bool did_p2p = 2;
	// preferred_derp is the human readable name of the preferred DERP region,
	// or the region used for the last ping, if it was sent over DERP.
	string preferred_derp = 3;
	// preferred_derp_latency is the last known latency to the preferred DERP
	// region. Unset if the region does not appear in the DERP map.
	optional google.protobuf.Duration preferred_derp_latency = 4;
}

// NetworkSettingsRequest is based on
// https://developer.apple.com/documentation/networkextension/nepackettunnelnetworksettings for
// macOS.  It is a request/response message with response NetworkSettingsResponse
message NetworkSettingsRequest {
	uint32 tunnel_overhead_bytes = 1;
	uint32 mtu = 2;

	message DNSSettings {
		repeated string servers = 1;
		repeated string search_domains = 2;
		// domain_name is the primary domain name of the tunnel
		string domain_name = 3;
		repeated string match_domains = 4;
		// match_domains_no_search specifies if the domains in the matchDomains list should not be
		// appended to the resolver’s list of search domains.
		bool match_domains_no_search = 5;
	}
	DNSSettings dns_settings = 3;

	string tunnel_remote_address = 4;

	message IPv4Settings {
		repeated string addrs = 1;
		repeated string subnet_masks = 2;
		// router is the next-hop router in dotted-decimal format
		string router = 3;

		message IPv4Route {
			string destination = 1;
			string mask = 2;
			// router is the next-hop router in dotted-decimal format
			string router = 3;
		}
		repeated IPv4Route included_routes = 4;
		repeated IPv4Route excluded_routes = 5;
	}
	IPv4Settings ipv4_settings = 5;

	message IPv6Settings {
		repeated string addrs = 1;
		repeated uint32 prefix_lengths = 2;

		message IPv6Route {
			string destination = 1;
			uint32 prefix_length = 2;
			// router is the address of the next-hop
			string router = 3;
		}
		repeated IPv6Route included_routes = 3;
		repeated IPv6Route excluded_routes = 4;
	}
	IPv6Settings ipv6_settings = 6;
}

// NetworkSettingsResponse is the response from the manager to the tunnel for a
// NetworkSettingsRequest
message NetworkSettingsResponse {
	bool success = 1;
	string error_message = 2;
}

// StartRequest is a request from the manager to start the tunnel.  The tunnel replies with a
// StartResponse.
message StartRequest {
	int32 tunnel_file_descriptor = 1;
	string coder_url = 2;
	string api_token = 3;
	// Additional HTTP headers added to all requests
	message Header {
		string name = 1;
		string value = 2;
	}
	repeated Header headers = 4;
	// Device ID from Coder Desktop
	string device_id = 5;
	// Device OS from Coder Desktop
	string device_os = 6;
	// Coder Desktop version
	string coder_desktop_version = 7;
}

message StartResponse {
	bool success = 1;
	string error_message = 2;
}

// StartProgress is sent from the manager to the client to indicate the
// download/startup progress of the tunnel. This will be sent during the
// processing of a StartRequest before the StartResponse is sent.
//
// Note: this is currently a broadcasted message to all clients due to the
//       inability to easily send messages to a specific client in the Speaker
//       implementation. If clients are not expecting these messages, they
//       should ignore them.
enum StartProgressStage {
	Initializing = 0;
	Downloading = 1;
	Finalizing = 2;
}
message StartProgressDownloadProgress {
	uint64 bytes_written = 1;
	optional uint64 bytes_total = 2; // unknown in some situations
}
message StartProgress {
	StartProgressStage stage = 1;
	optional StartProgressDownloadProgress download_progress = 2; // only set when stage == Downloading
}

// StopRequest is a request from the manager to stop the tunnel. The tunnel replies with a
// StopResponse.
message StopRequest {}

// StopResponse is a response to stopping the tunnel. After sending this response, the tunnel closes
// its side of the bidirectional stream for writing.
message StopResponse {
	bool success = 1;
	string error_message = 2;
}

// StatusRequest is a request to get the status of the tunnel. The manager
// replies with a Status.
message StatusRequest {}

// Status is sent in response to a StatusRequest or broadcasted to all clients
// when the status changes.
message Status {
	enum Lifecycle {
		UNKNOWN = 0;
		STARTING = 1;
		STARTED = 2;
		STOPPING = 3;
		STOPPED = 4;
	}
	Lifecycle lifecycle = 1;
	string error_message = 2;

	// This will be a FULL update with all workspaces and agents, so clients
	// should replace their current peer state. Only the Upserted fields will
	// be populated.
	PeerUpdate peer_update = 3;
}