SDT0601: Missing StringPacket Attribute

Property	Value
Rule ID	SDT0601
Title	Missing StringPacket Attribute
Category	Network
Severity	Error

Cause

A string parameter is being passed through a Remote Procedure Call (RPC), but it is not decorated with the [StringPacket] attribute, or the attribute specifies a maxLength of 0 or less.

Because strings are dynamically sized, the network layer requires a strict maximum byte size to safely pre-allocate buffers and prevent buffer overflow attacks or excessive bandwidth usage.

Rule Description

All string parameters in RPC methods must explicitly declare their maximum allowed length.

How to Fix Violations

To fix a violation of this rule, decorate the string parameter with the [StringPacket] attribute and provide a positive integer for the maximum size.

Violation:

[RPC(PacketBroadcast.Client)]
public void RPC_SendChatMessage(string message) 
{
    // ...
}

Fix:

[RPC(PacketBroadcast.Client)]
public void RPC_SendChatMessage([StringPacket(maxLength: 256)] string message) 
{
    // ...
}

When to Suppress Warnings