From 7943de01ed323edbbe39529dad60faf282ee11f4 Mon Sep 17 00:00:00 2001
From: Thomas SAZERAT <namulabre@gmail.com>
Date: Fri, 15 Mar 2024 00:42:27 +0100
Subject: [PATCH] added two new fonctionalities: The possibility to blacklist
 ip address with port, and the possibility to forward a message from an ip to
 another.

---
 config.json   |  4 +--
 src/config.rs | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/main.rs   | 24 +++++++++++----
 3 files changed, 103 insertions(+), 7 deletions(-)
 create mode 100644 src/config.rs

diff --git a/config.json b/config.json
index 6cdeef7..8b463d1 100644
--- a/config.json
+++ b/config.json
@@ -1,13 +1,13 @@
 {
   "forwarding": [
     {
-      "from": "127.0.0.1:12345",
+      "from": "127.0.0.1:58545",
       "to": "127.0.0.1:12346",
       "doReverse": true
     }
   ],
   "blacklist": [
     "127.0.0.1:11111",
-    "127.0.0.1:58109"
+    "127.0.0.1:55527"
   ]
 }
\ No newline at end of file
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..0857f22
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,82 @@
+use std::fs::File;
+use std::io::Read;
+
+use serde::Deserialize;
+use serde_json::Value;
+
+#[derive(Deserialize, Debug)]
+pub struct Forwarding {
+    from: String,
+    to: String,
+    #[serde(rename = "doReverse")]
+    do_reverse: bool
+}
+
+impl Forwarding {
+    pub fn new(from: String, to: String, do_reverse: bool) -> Forwarding {
+        return Forwarding{
+            from,
+            to,
+            do_reverse
+        }
+    }
+}
+
+#[derive(Deserialize)]
+pub struct Config {
+    blacklist: Vec<String>,
+    forwarding: Vec<Forwarding>
+}
+
+impl Config {
+    pub fn new(blacklist: Vec<String>, forwarding: Vec<Forwarding>) -> Config {
+        return Config {
+            blacklist,
+            forwarding
+        }
+    }
+
+    pub fn from_json(file_name: String) -> Config {
+        let mut file = File::open(file_name).unwrap();
+        let mut buf = String::new();
+        file.read_to_string(&mut buf).expect("Error reading config file content.");
+        let json: Value = serde_json::from_str(&buf).expect("Error parsing config file");
+        let object_data = json.as_object().unwrap();
+        let blacklist = object_data.get("blacklist").unwrap().as_array().unwrap();
+        let forwarding = object_data.get("forwarding").unwrap().as_array().unwrap();
+        let str_blacklist = Self::convert_to_vec_string(blacklist);
+        let mut vec_forwarding = Vec::new();
+        for json_forwarding in forwarding {
+            let object_forwarding = json_forwarding.as_object().unwrap();
+            let from = object_forwarding.get("from").unwrap().as_str().unwrap();
+            let to = object_forwarding.get("to").unwrap().as_str().unwrap();
+            let do_reverse = object_forwarding.get("doReverse").unwrap().as_bool().unwrap();
+            let forwarding_struct = Forwarding::new(from.to_string(), to.to_string(), do_reverse);
+            vec_forwarding.push(forwarding_struct);
+        }
+        Config::new(str_blacklist, vec_forwarding)
+    }
+
+    fn convert_to_vec_string(vec: &Vec<Value>) -> Vec<String> {
+        let mut str_vec = Vec::new();
+        for value in vec {
+            str_vec.push(value.as_str().unwrap().to_string());
+        }
+        str_vec
+    }
+
+    pub fn addr_is_blacklisted(&self, addr: String) -> bool {
+        self.blacklist.contains(&addr)
+    }
+
+    pub fn is_forwarded(&self, addr: String) -> Option<String> {
+        for elem_forwarding in &self.forwarding {
+            if elem_forwarding.from == addr {
+                return Some(elem_forwarding.to.clone())
+            } else if elem_forwarding.do_reverse && elem_forwarding.to == addr {
+                return Some(elem_forwarding.from.clone())
+            }
+        }
+        None
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 22c757b..4c0039d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,9 +1,13 @@
+mod config;
+
 use std::io::stdin;
 use std::net::UdpSocket;
+use crate::config::Config;
 
 fn main() {
+    let config = Config::from_json("config.json".to_string());
     let server_address: String = get_server_address();
-    listen(&server_address);
+    listen(&server_address, &config);
 }
 
 fn get_server_address() -> String {
@@ -13,7 +17,8 @@ fn get_server_address() -> String {
     return server_address.trim().to_string();
 }
 
-fn listen(server_address: &str) {
+fn listen(server_address: &str, config: &Config) {
+    let serv_config = config;
     println!("listening on {}", server_address);
     let socket: UdpSocket = UdpSocket::bind(server_address).expect("Error while binding the socket.");
 
@@ -21,8 +26,17 @@ fn listen(server_address: &str) {
         let mut message: String = String::new();
         let mut buf: [u8; 1024] = [0; 1024];
         let (num_bytes, src_addr) = socket.recv_from(&mut buf).expect("Error while receiving message");
-        message.push_str(std::str::from_utf8(&buf[..num_bytes]).expect("Invalid UTF-8 data"));
-
-        println!("{}:{}", src_addr.to_string(), message);
+        if !serv_config.addr_is_blacklisted(src_addr.to_string()) {
+            message.push_str(std::str::from_utf8(&buf[..num_bytes]).expect("Invalid UTF-8 data"));
+            match serv_config.is_forwarded(src_addr.to_string()) {
+                Some(v) => {
+                    socket.send_to(message.as_bytes(), v).expect("Error forwarding message to another ip.");
+                },
+                None => {
+                    //Nothing to do :)
+                }
+            }
+            println!("{} say: {}", src_addr.to_string(), message);
+        }
     }
 }