pso_packet proc_macro for misc things

Cargo.toml

@@ -5,3 +5,4 @@ authors = ["Jake Probst <jake.probst@gmail.com>"]
 edition = "2018"
 
 [dependencies]
+psopacket = { path = "psopacket" }

psopacket/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "psopacket"
+version = "1.0.0"
+authors = ["Jake Probst <jake.probst@gmail.com>"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = {version = "0.15", features=["full", "extra-traits", "parsing"]}
+quote = "0.6"

psopacket/src/lib.rs

@@ -0,0 +1,255 @@
+#![recursion_limit="128"]
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use syn::{parse_macro_input, ItemStruct};
+use quote::quote;
+
+#[proc_macro_attribute]
+pub fn pso_packet(attr: TokenStream, item: TokenStream) -> TokenStream {
+    let arg = parse_macro_input!(attr as syn::LitInt);
+    let pkt_cmd = arg.value() as u16;
+    
+    let parsed = parse_macro_input!(item as ItemStruct);
+
+    let mut has_flag: bool = false;
+    let mut from_bytes = Vec::new();
+    let mut as_bytes = Vec::new();
+    let mut dbg_write_vars = Vec::new();
+    let mut partialeq = Vec::new();
+    
+    for (i, f) in parsed.fields.iter().enumerate() {
+        if let Some(ident) = &f.ident {
+            let ident_str = ident.to_string();
+
+            match &f.ty {
+                syn::Type::Array(arr) => {
+                    let array_length = if let syn::Expr::Lit(lit) = &arr.len {
+                        if let syn::Lit::Int(int) = &lit.lit {
+                            int.value() as usize
+                        }
+                        else {
+                            return syn::Error::new(arr.bracket_token.span, "unknown array size").to_compile_error().into();
+                        }
+                    } else {
+                        return syn::Error::new(arr.bracket_token.span, "unknown array size").to_compile_error().into();
+                    };
+                    match *arr.elem {
+                        syn::Type::Path(ref path) => {
+                            dbg_write_vars.push(quote! {
+                                write!(f, "    {}: {:?}\n", #ident_str, self.#ident.iter()).unwrap();
+                            });
+                            as_bytes.push(quote! {
+                                for f in self.#ident.iter() {
+                                    buf.extend_from_slice(&f.to_le_bytes())
+                                }
+                            });
+                            let ty = path.path.segments[0].ident.to_string();
+                            match ty.as_str() {
+                                "u8" => {
+                                    from_bytes.push(quote! {
+                                        #ident: {
+                                            let mut b: [u8; #array_length] = [0; #array_length];
+                                            if let Ok(len) = cur.read(&mut b) {
+                                                if len != #array_length {
+                                                    return Err(PacketParseError::NotEnoughBytes);
+                                                }
+                                            }
+                                            else {
+                                                return Err(PacketParseError::NotEnoughBytes);
+                                            };
+                                            b
+                                        },
+                                    });
+                                },
+                                _ => {
+                                    return syn::Error::new(path.path.segments[0].ident.span(), "type not supported")
+                                        .to_compile_error().into();
+                                }
+                            }
+                            partialeq.push(quote! {
+                                if self.#ident[..] != other.#ident[..] {
+                                    return false;
+                                }
+                            });
+                        }
+                        _ => {
+                            panic!("why");
+                        }
+                    }
+                },
+                syn::Type::Path(path) => {
+                    dbg_write_vars.push(quote! {
+                        write!(f, "    {}: {:?}\n", #ident_str, self.#ident).unwrap();
+                    });
+                    as_bytes.push(quote! {
+                        buf.extend_from_slice(&self.#ident.to_le_bytes());
+                    });
+                    let ty = path.path.segments[0].ident.to_string();
+                    match ty.as_str() {
+                        "u8" => {
+                            from_bytes.push(quote! {
+                                #ident: {
+                                    let mut b: [u8; 1] = [0; 1];
+                                    if let Ok(len) = cur.read(&mut b) {
+                                        if len != 1 {
+                                            return Err(PacketParseError::NotEnoughBytes);
+                                        }
+                                    }
+                                    else {
+                                        return Err(PacketParseError::NotEnoughBytes);
+                                    };
+                                    b[0]
+                                },
+                            });
+                        },
+                        "u16" => {
+                            from_bytes.push(quote! {
+                                #ident: {
+                                    let mut b: [u8; 2] = [0; 2];
+                                    if let Ok(len) = cur.read(&mut b) {
+                                        if len != 2 {
+                                            return Err(PacketParseError::NotEnoughBytes);
+                                        }
+                                    }
+                                    else {
+                                        return Err(PacketParseError::NotEnoughBytes);
+                                    };
+                                    u16::from_le_bytes(b)
+                                },
+                            });
+                        },
+                        "u32" => {
+                            if ident_str == "flag" {
+                                if i != 0 {
+                                    return syn::Error::new(ident.span(), "flag must be first member of struct").to_compile_error().into();
+                                }
+                                has_flag = true;
+                                continue;
+                            }
+                            from_bytes.push(quote! {
+                                #ident: {
+                                    let mut b: [u8; 4] = [0; 4];
+                                    if let Ok(len) = cur.read(&mut b) {
+                                        if len != 4 {
+                                            return Err(PacketParseError::NotEnoughBytes);
+                                        }
+                                    }
+                                    else {
+                                        return Err(PacketParseError::NotEnoughBytes);
+                                    };
+                                    u32::from_le_bytes(b)
+                                },
+                            });
+                        },
+                        _ => {
+                            return syn::Error::new(path.path.segments[0].ident.span(), "type not supported")
+                                .to_compile_error().into();
+                        }
+                    }
+                    partialeq.push(quote! {
+                        if self.#ident != other.#ident {
+                            return false;
+                        }
+                    });
+                }
+                _ => {
+                }
+            }
+        }
+    }
+
+    let this_struct = parsed.ident.clone();
+    let this_struct_str = this_struct.to_string();
+
+    let flag_write = if has_flag {
+        quote! {
+            buf.extend_from_slice(&u32::to_le_bytes(self.flag));
+        }
+    }
+    else {
+        quote! {
+            buf.extend_from_slice(&u32::to_le_bytes(0));
+        }
+    };
+
+    let psopacket = quote! {
+        impl PSOPacket for #this_struct {
+            fn from_bytes(data: &Vec<u8>) -> Result<#this_struct, PacketParseError> {
+                // TODO: assert cmd is correct
+                let mut cur = std::io::Cursor::new(data);
+                cur.seek(SeekFrom::Start(2));
+                let mut b: [u8; 2] = [0; 2];
+                cur.read(&mut b);
+                let cmd = u16::from_le_bytes(b);
+
+                if cmd != #pkt_cmd {
+                    return Err(PacketParseError::WrongPacketCommand);
+                }
+                
+                if #has_flag {
+                    cur.seek(SeekFrom::Start(4));
+                }
+                else {
+                    cur.seek(SeekFrom::Start(8));
+                }
+                Ok(#this_struct {
+                    #(#from_bytes)*
+                })
+            }
+            fn as_bytes(&self) -> Vec<u8> {
+                let mut buf: Vec<u8> = Vec::new();
+                #flag_write
+                #(#as_bytes)*
+
+                let pkt_len = buf.len() as u16;
+                let mut prebuf: Vec<u8> = Vec::new();
+
+                prebuf.extend_from_slice(&u16::to_le_bytes(pkt_len));
+                prebuf.extend_from_slice(&u16::to_le_bytes(#pkt_cmd));
+                prebuf.append(&mut buf);
+
+                prebuf
+            }
+        }
+    };
+    
+    
+    let psopacket_debug = quote! {
+        impl std::fmt::Debug for #this_struct {
+            fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                write!(f, "packet {} {{\n", #this_struct_str).unwrap();
+                #(#dbg_write_vars)*
+                write!(f, "}}")
+            }
+        }
+    };
+
+
+    let psopacket_partialeq = quote! {
+        impl std::cmp::PartialEq for #this_struct {
+            fn eq(&self, other: &Self) -> bool {
+                #(#partialeq)*
+                true
+            }
+        }
+    };
+
+    let q = quote! {
+        #parsed
+        #psopacket
+        #psopacket_debug
+        #psopacket_partialeq
+    };
+
+    //println!("[[[{}]]]", q.to_string());
+    
+    q.into()
+}
+
+
+#[proc_macro_attribute]
+pub fn game_command(attr: TokenStream, item: TokenStream) -> TokenStream {
+    item
+}

src/lib.rs

@@ -1,7 +1,16 @@
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
-    }
+mod patch;
+
+#[derive(Debug, PartialEq)]
+pub enum PacketParseError {
+    NotEnoughBytes,
+    WrongPacketCommand,
 }
+
+
+pub trait PSOPacket {
+    fn from_bytes(data: &Vec<u8>) -> Result<Self, PacketParseError> where Self: Sized;
+    fn as_bytes(&self) -> Vec<u8>;
+}
+
+
+

src/patch/mod.rs

@@ -0,0 +1,2 @@
+
+mod packet;

src/patch/packet.rs

@@ -0,0 +1,58 @@
+use psopacket::pso_packet;
+use crate::{PSOPacket, PacketParseError};
+
+use std::io::{Read, Seek, SeekFrom};
+
+
+#[pso_packet(0x02)]
+struct PatchWelcome {
+    copyright: [u8; 44],
+    padding: [u8; 20],
+    server_key: u32,
+    client_key: u32,
+}
+
+impl PatchWelcome {
+    fn new(server_key: u32, client_key: u32) -> PatchWelcome {
+        PatchWelcome {
+            copyright: b"Patch Server. Copyright SonicTeam, LTD. 2001".clone(),
+            padding: [0; 20],
+            server_key: server_key,
+            client_key: client_key,
+        }
+    }
+}
+
+enum PatchPackets {
+    PatchWelcome(PatchWelcome)
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn patch_welcome() {
+        use super::PSOPacket;
+
+        let pkt = super::PatchWelcome::new(123, 456);
+
+        assert!(pkt.as_bytes() == vec![0x4C, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x61, 0x74, 0x63, 0x68, 0x20, 0x53, 0x65,
+                                       0x72, 0x76, 0x65, 0x72, 0x2E, 0x20, 0x43, 0x6F, 0x70, 0x79, 0x72, 0x69, 0x67, 0x68, 0x74, 0x20,
+                                       0x53, 0x6F, 0x6E, 0x69, 0x63, 0x54, 0x65, 0x61, 0x6D, 0x2C, 0x20, 0x4C, 0x54, 0x44, 0x2E, 0x20,
+                                       0x32, 0x30, 0x30, 0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                                       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7B, 0x00, 0x00, 0x00, 0xC8, 0x01, 0x00, 0x00,
+        ]);
+
+
+        let mut bytes = pkt.as_bytes();
+        bytes.splice(32..41, b"Elsewhere".iter().cloned());
+
+        let new_pkt = super::PatchWelcome::from_bytes(&bytes);
+
+        assert!(new_pkt == Ok(super::PatchWelcome {
+            copyright: b"Patch Server. Copyright Elsewhere, LTD. 2001".clone(),
+            padding: [0; 20],
+            server_key: 123,
+            client_key: 456,
+        }))
+    }
+}