Added basic spam protection.

source/app.d

@@ -41,19 +41,43 @@ void main() {
 }
 
 void handleVisitorLog(ref HttpRequestContext ctx) {
-	infoF!"Got visitor log from %s"(ctx.request.remoteAddress);
 	JSONValue logBody = ctx.request.readBodyAsJson();
 	string name = logBody.object["name"].str;
+	if (name.length > 32) {
+		ctx.response.setStatus(HttpStatus.BAD_REQUEST);
+		ctx.response.writeBodyString("Name is too long.");
+		return;
+	}
 	string message = logBody.object["message"].str;
-	string remoteAddress = "UNKNOWN";
+	if (message.length > 255) {
-	if (ctx.request.remoteAddress !is null) {
+		ctx.response.setStatus(HttpStatus.BAD_REQUEST);
-		remoteAddress = ctx.request.remoteAddress.toString();
+		ctx.response.writeBodyString("Message is too long.");
+		return;
+	}
+	if (!ctx.request.hasHeader("X-Forwarded-For")) {
+		ctx.response.setStatus(HttpStatus.FORBIDDEN);
+		ctx.response.writeBodyString("Missing remote IP");
+		return;
+	}
+	string remoteAddress = ctx.request.getHeader("X-Forwarded-For");
+	LogEntry[] recentLogsByThisAddress = getRecentLogEntriesByRemoteAddress(remoteAddress);
+	SysTime now = Clock.currTime();
+	if (recentLogsByThisAddress.length > 0 && now - recentLogsByThisAddress[0].createdAt < minutes(1)) {
+		ctx.response.setStatus(HttpStatus.TOO_MANY_REQUESTS);
+		return;
 	}
 	insertLogEntry(remoteAddress, name, message);
 }
 
 void handleLogbookRequest(ref HttpRequestContext ctx) {
-	LogEntry[] entries = getRecentLogEntries();
+	uint limit = ctx.request.getParamAs!uint("limit", 5);
+	if (limit > 100) {
+		ctx.response.setStatus(HttpStatus.BAD_REQUEST);
+		ctx.response.writeBodyString("Limit is too large.");
+		return;
+	}
+	uint offset = ctx.request.getParamAs!uint("offset", 0);
+	LogEntry[] entries = getRecentLogEntries(limit, offset);
 	JSONValue entriesJson = JSONValue(JSONValue[].init);
 	foreach (LogEntry entry; entries) {
 		entriesJson.array ~= entry.toJson();
@@ -79,6 +103,19 @@ struct LogEntry {
 		obj["message"] = JSONValue(message);
 		return obj;
 	}
+
+	static LogEntry fromDbRow(ref Row row) {
+		LogEntry entry;
+		entry.id = row.peek!ulong(0);
+		string createdAtStr = row.peek!string(1);
+		string isoCreatedAt = createdAtStr[0 .. 4] ~ createdAtStr[5 .. 7] ~ createdAtStr[8 .. 10] ~ 'T' ~
+			createdAtStr[11 .. 13] ~ createdAtStr[14 .. 16] ~ createdAtStr[17 .. $];
+		entry.createdAt = SysTime.fromISOString(isoCreatedAt);
+		entry.remoteAddress = row.peek!string(2);
+		entry.name = row.peek!string(3);
+		entry.message = row.peek!string(4);
+		return entry;
+	}
 }
 
 void initDb() {
@@ -111,21 +148,32 @@ SQL");
 	infoF!"Added log entry for %s @ %s"(name, remoteAddress);
 }
 
-LogEntry[] getRecentLogEntries() {
+LogEntry[] findAllByQuery(string query) {
+	import std.array : Appender, appender;
 	Database db = Database("logbook.sqlite");
-	ResultRange results = db.execute("SELECT * FROM log_entry ORDER BY created_at DESC LIMIT 5");
+	ResultRange results = db.execute(query);
-	LogEntry[] entries;
+	Appender!(LogEntry[]) app = appender!(LogEntry[])();
 	foreach (Row row; results) {
-		LogEntry entry;
+		app ~= LogEntry.fromDbRow(row);
-		entry.id = row.peek!ulong(0);
-		string createdAtStr = row.peek!string(1);
-		string isoCreatedAt = createdAtStr[0 .. 4] ~ createdAtStr[5 .. 7] ~ createdAtStr[8 .. 10] ~ 'T' ~
-			createdAtStr[11 .. 13] ~ createdAtStr[14 .. 16] ~ createdAtStr[17 .. $];
-		entry.createdAt = SysTime.fromISOString(isoCreatedAt);
-		entry.remoteAddress = row.peek!string(2);
-		entry.name = row.peek!string(3);
-		entry.message = row.peek!string(4);
-		entries ~= entry;
 	}
-	return entries;
+	return app.data();
+}
+
+LogEntry[] getRecentLogEntries(uint limit, uint offset) {
+	import std.format;
+	string query = format!"SELECT * FROM log_entry ORDER BY created_at DESC LIMIT %d OFFSET %d"(limit, offset);
+	return findAllByQuery(query);
+}
+
+LogEntry[] getRecentLogEntriesByRemoteAddress(string remoteAddress) {
+	import std.array : Appender, appender;
+	Database db = Database("logbook.sqlite");
+	Statement stmt = db.prepare("SELECT * FROM log_entry WHERE remote_address = :addr ORDER BY created_at DESC LIMIT 10");
+	stmt.bind(0, remoteAddress);
+	ResultRange results = stmt.execute();
+	Appender!(LogEntry[]) app = appender!(LogEntry[])();
+	foreach (Row row; results) {
+		app ~= LogEntry.fromDbRow(row);
+	}
+	return app.data();
 }