check protocol

src/handle.zig

@@ -3,27 +3,80 @@ const log = std.log;
 const net = std.net;
 const ArrayList = std.ArrayList;
 
-pub fn handleClient(allocator: std.mem.Allocator, server: *net.Server) !void {
+pub const Protocol = enum {
-    var full_message = ArrayList(u8).init(allocator);
+    HTTP,
-    defer full_message.deinit();
+    SSH,
+    // DNS,
+    // FTP,
+    // SMTP,
+    // IMAP,
+    // POP3,
+    Unknown,
+};
+
+const ProtocolMap = struct {
+    prefix: []const u8,
+    protocol: Protocol,
+};
+
+const ProtocolMappings = [_]ProtocolMap{
+    .{ .prefix = "HTTP/1.1", .protocol = .HTTP },
+    .{ .prefix = "GET", .protocol = Protocol.HTTP },
+    .{ .prefix = "HEAD", .protocol = Protocol.HTTP },
+    .{ .prefix = "POST", .protocol = Protocol.HTTP },
+    .{ .prefix = "PUT", .protocol = Protocol.HTTP },
+    .{ .prefix = "DELETE", .protocol = Protocol.HTTP },
+    .{ .prefix = "CONNECT", .protocol = Protocol.HTTP },
+    .{ .prefix = "OPTIONS", .protocol = Protocol.HTTP },
+    .{ .prefix = "TRACE", .protocol = Protocol.HTTP },
+    .{ .prefix = "PATCH", .protocol = Protocol.HTTP },
+    .{ .prefix = "SSH-", .protocol = Protocol.SSH },
+};
+
+/// ### check protocol
+///
+/// ### author
+/// * Shawn Jones
+fn detectApplicationLayerProtocol(data: []u8) Protocol {
+    for (ProtocolMappings) |mapping| {
+        if (std.mem.startsWith(u8, data, mapping.prefix)) {
+            return mapping.protocol;
+        }
+    }
+    return Protocol.Unknown;
+}
+
+pub fn handleClient(_: std.mem.Allocator, server: *net.Server) !void {
+    // var full_message = ArrayList(u8).init(allocator);
+    // defer full_message.deinit();
 
     while (true) {
+        const client = try server.accept();
+        // log.info("has a client connected: {any}", .{client});
+        defer client.stream.close();
         // [TODO 1] check protocol
+
+        var prefix: [10]u8 = undefined;
+        _ = try client.stream.read(&prefix);
+        log.info("prefix is {s}\n", .{prefix});
+        log.info("{?}\n", .{@TypeOf(prefix)});
+        const protocol: Protocol = detectApplicationLayerProtocol(&prefix);
+        log.info("the client using protocol is {?}\n", .{protocol});
+        if (protocol == Protocol.Unknown) {
+            log.err("Unsupport protocol!", .{});
+            continue;
+        }
         // [TODO 2] forward data
         // accept from client
-        const client = try server.accept();
+        // var message: [4]u8 = undefined;
-        log.info("has a client connected: {any}", .{client});
+        // var total_len: usize = 0;
-        defer client.stream.close();
+        // r: while (true) {
-
+        //     const bytesRead = try client.stream.readAll(&message);
-        var message: [4]u8 = undefined;
+        //     if (bytesRead == 0) break :r;
-        var total_len: usize = 0;
+        //     total_len += bytesRead;
-        r: while (true) {
+        //     std.debug.print("Received: {s}\n", .{message[0..bytesRead]});
-            const bytesRead = try client.stream.readAll(&message);
+        //     try full_message.appendSlice(message[0..bytesRead]);
-            if (bytesRead == 0) break :r;
+        // }
-            total_len += bytesRead;
+        // log.info("Full Message: {s}\n", .{full_message.items});
-            std.debug.print("Received: {s}\n", .{message[0..bytesRead]});
-            try full_message.appendSlice(message[0..bytesRead]);
-        }
-        log.info("Full Message: {s}\n", .{full_message.items});
     }
 }