Use FAIL as the default dest if unable to parse

The dest can be specified as a 4 char ASCII string, or as an IPv4 address.

build.zig

@@ -15,6 +15,12 @@ pub fn build(b: *std.Build) void {
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
 
+    const lib_mod = b.createModule(.{
+        .root_source_file = b.path("src/root.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
     // We will also create a module for our other entry point, 'main.zig'.
     const exe_mod = b.createModule(.{
         // `root_source_file` is the Zig "entry point" of the module. If a module
@@ -26,9 +32,19 @@ pub fn build(b: *std.Build) void {
         .optimize = optimize,
     });
 
-    exe_mod.addImport("network", b.dependency("network", .{}).module("network"));
+    lib_mod.addImport("network", b.dependency("network", .{}).module("network"));
+
+    exe_mod.addImport("zaprus", lib_mod);
     exe_mod.addImport("clap", b.dependency("clap", .{}).module("clap"));
 
+    const lib = b.addLibrary(.{
+        .linkage = .static,
+        .name = "zaprus",
+        .root_module = lib_mod,
+    });
+
+    b.installArtifact(lib);
+
     // This creates another `std.Build.Step.Compile`, but this one builds an executable
     // rather than a static library.
     const exe = b.addExecutable(.{

src/Client.zig

@@ -39,10 +39,10 @@ fn broadcastSaprusMessage(msg: SaprusMessage, udp_port: u16, allocator: Allocato
     _ = try sock.sendTo(dest_addr, msg_bytes);
 }
 
-pub fn sendRelay(payload: []const u8, allocator: Allocator) !void {
+pub fn sendRelay(payload: []const u8, dest: [4]u8, allocator: Allocator) !void {
     const msg = SaprusMessage{
         .relay = .{
-            .header = .{ .dest = .{ 70, 70, 70, 70 } },
+            .header = .{ .dest = dest },
             .payload = payload,
         },
     };
@@ -112,7 +112,7 @@ pub fn connect(payload: []const u8, allocator: Allocator) !?SaprusMessage {
     return initial_conn_res;
 }
 
-pub const SaprusMessage = @import("./saprus_message.zig").SaprusMessage;
+const SaprusMessage = @import("message.zig").Message;
 
 const std = @import("std");
 const Random = std.Random;

src/main.zig

@@ -23,6 +23,7 @@ pub fn main() !void {
     const params = comptime clap.parseParamsComptime(
         \\-h, --help           Display this help and exit.
         \\-r, --relay <str>    A relay message to send.
+        \\-d, --dest <str>     An IPv4 or <= 4 ASCII byte string.
         \\-c, --connect <str>  A connection message to send.
         \\
     );
@@ -41,19 +42,24 @@ pub fn main() !void {
     };
     defer res.deinit();
 
-    try Saprus.init();
-    defer Saprus.deinit();
+    try SaprusClient.init();
+    defer SaprusClient.deinit();
 
     if (res.args.help != 0) {
         return clap.help(std.io.getStdErr().writer(), clap.Help, &params, .{});
     }
 
     if (res.args.relay) |r| {
-        try Saprus.sendRelay(if (r.len > 0) r else "Hello darkness my old friend", gpa);
+        const dest = parseDest(res.args.dest) catch .{ 70, 70, 70, 70 };
+        try SaprusClient.sendRelay(
+            if (r.len > 0) r else "Hello darkness my old friend",
+            dest,
+            gpa,
+        );
         // std.debug.print("Sent: {s}\n", .{r});
         return;
     } else if (res.args.connect) |c| {
-        const conn_res: ?SaprusMessage = Saprus.connect(if (c.len > 0) c else "Hello darkness my old friend", gpa) catch |err| switch (err) {
+        const conn_res: ?SaprusMessage = SaprusClient.connect(if (c.len > 0) c else "Hello darkness my old friend", gpa) catch |err| switch (err) {
             error.WouldBlock => null,
             else => return err,
         };
@@ -69,12 +75,27 @@ pub fn main() !void {
     return clap.help(std.io.getStdErr().writer(), clap.Help, &params, .{});
 }
 
+fn parseDest(in: ?[]const u8) [4]u8 {
+    if (in) |dest| {
+        if (dest.len <= 4) {
+            var res: [4]u8 = @splat(0);
+            @memcpy(res[0..dest.len], dest);
+            return res;
+        }
+
+        const addr = std.net.Ip4Address.parse(dest, 0) catch return "FAIL".*;
+        return @bitCast(addr.sa.addr);
+    }
+    return "zap".*;
+}
+
 const builtin = @import("builtin");
 const std = @import("std");
 const DebugAllocator = std.heap.DebugAllocator(.{});
 const ArrayList = std.ArrayList;
 
-const Saprus = @import("./saprus.zig");
-const SaprusMessage = Saprus.SaprusMessage;
+const zaprus = @import("zaprus");
+const SaprusClient = zaprus.Client;
+const SaprusMessage = zaprus.Message;
 
 const clap = @import("clap");

src/message.zig

@@ -1,9 +1,9 @@
 const base64Enc = std.base64.Base64Encoder.init(std.base64.standard_alphabet_chars, '=');
 const base64Dec = std.base64.Base64Decoder.init(std.base64.standard_alphabet_chars, '=');
 
-/// Type tag for SaprusMessage union.
+/// Type tag for Message union.
 /// This is the first value in the actual packet sent over the network.
-pub const SaprusPacketType = enum(u16) {
+pub const PacketType = enum(u16) {
     relay = 0x003C,
     file_transfer = 0x8888,
     connection = 0x00E9,
@@ -12,7 +12,7 @@ pub const SaprusPacketType = enum(u16) {
 
 /// Reserved option values.
 /// Currently unused.
-pub const SaprusConnectionOptions = packed struct(u8) {
+pub const ConnectionOptions = packed struct(u8) {
     opt1: bool = false,
     opt2: bool = false,
     opt3: bool = false,
@@ -23,13 +23,13 @@ pub const SaprusConnectionOptions = packed struct(u8) {
     opt8: bool = false,
 };
 
-pub const SaprusError = error{
+pub const Error = error{
     NotImplementedSaprusType,
     UnknownSaprusType,
 };
 
 /// All Saprus messages
-pub const SaprusMessage = union(SaprusPacketType) {
+pub const Message = union(PacketType) {
     pub const Relay = struct {
         pub const Header = packed struct {
             dest: @Vector(4, u8),
@@ -44,7 +44,7 @@ pub const SaprusMessage = union(SaprusPacketType) {
             seq_num: u32 = 0,
             msg_id: u32 = 0,
             reserved: u8 = 0,
-            options: SaprusConnectionOptions = .{},
+            options: ConnectionOptions = .{},
         };
         header: Header,
         payload: []const u8,
@@ -53,8 +53,8 @@ pub const SaprusMessage = union(SaprusPacketType) {
     file_transfer: void, // unimplemented
     connection: Connection,
 
-    /// Should be called for any SaprusMessage that was declared using a function that you pass an allocator to.
-    pub fn deinit(self: SaprusMessage, allocator: Allocator) void {
+    /// Should be called for any Message that was declared using a function that you pass an allocator to.
+    pub fn deinit(self: Message, allocator: Allocator) void {
         switch (self) {
             .relay => |r| allocator.free(r.payload),
             .connection => |c| allocator.free(c.payload),
@@ -96,7 +96,7 @@ pub const SaprusMessage = union(SaprusPacketType) {
     }
 
     /// Caller is responsible for freeing the returned bytes.
-    pub fn toBytes(self: SaprusMessage, allocator: Allocator) ![]u8 {
+    pub fn toBytes(self: Message, allocator: Allocator) ![]u8 {
         // Create a growable list of bytes to store the output in.
         var buf = std.ArrayList(u8).init(allocator);
         errdefer buf.deinit();
@@ -108,7 +108,7 @@ pub const SaprusMessage = union(SaprusPacketType) {
         switch (self) {
             .relay => |r| try toBytesAux(r.header, r.payload, &buf, allocator),
             .connection => |c| try toBytesAux(c.header, c.payload, &buf, allocator),
-            .file_transfer => return SaprusError.NotImplementedSaprusType,
+            .file_transfer => return Error.NotImplementedSaprusType,
         }
 
         // Collect the growable list as a slice and return it.
@@ -116,12 +116,12 @@ pub const SaprusMessage = union(SaprusPacketType) {
     }
 
     fn fromBytesAux(
-        comptime packet: SaprusPacketType,
+        comptime packet: PacketType,
         len: u16,
         r: std.io.FixedBufferStream([]const u8).Reader,
         allocator: Allocator,
-    ) !SaprusMessage {
-        const Header = @field(@FieldType(SaprusMessage, @tagName(packet)), "Header");
+    ) !Message {
+        const Header = @field(@FieldType(Message, @tagName(packet)), "Header");
 
         // Read the header for the current message type.
         var header_bytes: [@sizeOf(Header)]u8 = undefined;
@@ -138,20 +138,20 @@ pub const SaprusMessage = union(SaprusPacketType) {
         const payload = try allocator.alloc(u8, try base64Dec.calcSizeForSlice(payload_buf));
         try base64Dec.decode(payload, payload_buf);
 
-        // Return the type of SaprusMessage specified by the `packet` argument.
-        return @unionInit(SaprusMessage, @tagName(packet), .{
+        // Return the type of Message specified by the `packet` argument.
+        return @unionInit(Message, @tagName(packet), .{
             .header = header,
             .payload = payload,
         });
     }
 
     /// Caller is responsible for calling .deinit on the returned value.
-    pub fn fromBytes(bytes: []const u8, allocator: Allocator) !SaprusMessage {
+    pub fn fromBytes(bytes: []const u8, allocator: Allocator) !Message {
         var s = std.io.fixedBufferStream(bytes);
         const r = s.reader();
 
         // Read packet type
-        const packet_type = @as(SaprusPacketType, @enumFromInt(try r.readInt(u16, .big)));
+        const packet_type = @as(PacketType, @enumFromInt(try r.readInt(u16, .big)));
 
         // Read the length of the header + base64 encoded payload.
         const len = try r.readInt(u16, .big);
@@ -159,8 +159,8 @@ pub const SaprusMessage = union(SaprusPacketType) {
         switch (packet_type) {
             .relay => return fromBytesAux(.relay, len, r, allocator),
             .connection => return fromBytesAux(.connection, len, r, allocator),
-            .file_transfer => return SaprusError.NotImplementedSaprusType,
-            else => return SaprusError.UnknownSaprusType,
+            .file_transfer => return Error.NotImplementedSaprusType,
+            else => return Error.UnknownSaprusType,
         }
     }
 };
@@ -173,7 +173,7 @@ const nativeToBig = std.mem.nativeToBig;
 
 test "Round trip Relay toBytes and fromBytes" {
     const gpa = std.testing.allocator;
-    const msg = SaprusMessage{
+    const msg = Message{
         .relay = .{
             .header = .{ .dest = .{ 255, 255, 255, 255 } },
             .payload = "Hello darkness my old friend",
@@ -183,7 +183,7 @@ test "Round trip Relay toBytes and fromBytes" {
     const to_bytes = try msg.toBytes(gpa);
     defer gpa.free(to_bytes);
 
-    const from_bytes = try SaprusMessage.fromBytes(to_bytes, gpa);
+    const from_bytes = try Message.fromBytes(to_bytes, gpa);
     defer from_bytes.deinit(gpa);
 
     try std.testing.expectEqualDeep(msg, from_bytes);
@@ -191,7 +191,7 @@ test "Round trip Relay toBytes and fromBytes" {
 
 test "Round trip Connection toBytes and fromBytes" {
     const gpa = std.testing.allocator;
-    const msg = SaprusMessage{
+    const msg = Message{
         .connection = .{
             .header = .{
                 .src_port = 0,
@@ -204,7 +204,7 @@ test "Round trip Connection toBytes and fromBytes" {
     const to_bytes = try msg.toBytes(gpa);
     defer gpa.free(to_bytes);
 
-    const from_bytes = try SaprusMessage.fromBytes(to_bytes, gpa);
+    const from_bytes = try Message.fromBytes(to_bytes, gpa);
     defer from_bytes.deinit(gpa);
 
     try std.testing.expectEqualDeep(msg, from_bytes);

src/root.zig

@@ -0,0 +1,2 @@
+pub const Client = @import("Client.zig");
+pub usingnamespace @import("message.zig");