Implement IP tracking and user limit checks

Added IP tracking and cleanup functionality for users.

src/proxy/client.rs

@@ -11,6 +11,7 @@ use tracing::{debug, warn};
 use crate::config::ProxyConfig;
 use crate::crypto::SecureRandom;
 use crate::error::{HandshakeResult, ProxyError, Result};
+use crate::ip_tracker::UserIpTracker;
 use crate::protocol::constants::*;
 use crate::protocol::tls;
 use crate::stats::{ReplayChecker, Stats};
@@ -35,6 +36,7 @@ pub struct RunningClientHandler {
     buffer_pool: Arc<BufferPool>,
     rng: Arc<SecureRandom>,
     me_pool: Option<Arc<MePool>>,
+    ip_tracker: Arc<UserIpTracker>,
 }
 
 impl ClientHandler {
@@ -48,6 +50,7 @@ impl ClientHandler {
         buffer_pool: Arc<BufferPool>,
         rng: Arc<SecureRandom>,
         me_pool: Option<Arc<MePool>>,
+        ip_tracker: Arc<UserIpTracker>,
     ) -> RunningClientHandler {
         RunningClientHandler {
             stream,
@@ -59,6 +62,7 @@ impl ClientHandler {
             buffer_pool,
             rng,
             me_pool,
+            ip_tracker,
         }
     }
 }
@@ -203,6 +207,8 @@ impl RunningClientHandler {
             self.rng,
             self.me_pool,
             local_addr,
+            peer,
+            self.ip_tracker,
         )
         .await
     }
@@ -261,6 +267,8 @@ impl RunningClientHandler {
             self.rng,
             self.me_pool,
             local_addr,
+            peer,
+            self.ip_tracker,
         )
         .await
     }
@@ -280,6 +288,8 @@ impl RunningClientHandler {
         rng: Arc<SecureRandom>,
         me_pool: Option<Arc<MePool>>,
         local_addr: SocketAddr,
+        peer_addr: SocketAddr,
+        ip_tracker: Arc<UserIpTracker>,
     ) -> Result<()>
     where
         R: AsyncRead + Unpin + Send + 'static,
@@ -287,11 +297,36 @@ impl RunningClientHandler {
     {
         let user = &success.user;
 
-        if let Err(e) = Self::check_user_limits_static(user, &config, &stats) {
+        if let Err(e) = Self::check_user_limits_static(user, &config, &stats, peer_addr, &ip_tracker).await {
             warn!(user = %user, error = %e, "User limit exceeded");
             return Err(e);
         }
 
+        // IP Cleanup Guard: автоматически удаляет IP при выходе из scope
+        struct IpCleanupGuard {
+            tracker: Arc<UserIpTracker>,
+            user: String,
+            ip: std::net::IpAddr,
+        }
+        
+        impl Drop for IpCleanupGuard {
+            fn drop(&mut self) {
+                let tracker = self.tracker.clone();
+                let user = self.user.clone();
+                let ip = self.ip;
+                tokio::spawn(async move {
+                    tracker.remove_ip(&user, ip).await;
+                    debug!(user = %user, ip = %ip, "IP cleaned up on disconnect");
+                });
+            }
+        }
+        
+        let _cleanup = IpCleanupGuard {
+            tracker: ip_tracker,
+            user: user.clone(),
+            ip: peer_addr.ip(),
+        };
+
         // Decide: middle proxy or direct
         if config.general.use_middle_proxy {
             if let Some(ref pool) = me_pool {
@@ -324,7 +359,13 @@ impl RunningClientHandler {
         .await
     }
 
-    fn check_user_limits_static(user: &str, config: &ProxyConfig, stats: &Stats) -> Result<()> {
+    async fn check_user_limits_static(
+        user: &str, 
+        config: &ProxyConfig, 
+        stats: &Stats,
+        peer_addr: SocketAddr,
+        ip_tracker: &UserIpTracker,
+    ) -> Result<()> {
         if let Some(expiration) = config.access.user_expirations.get(user) {
             if chrono::Utc::now() > *expiration {
                 return Err(ProxyError::UserExpired {
@@ -333,6 +374,19 @@ impl RunningClientHandler {
             }
         }
 
+        // IP limit check
+        if let Err(reason) = ip_tracker.check_and_add(user, peer_addr.ip()).await {
+            warn!(
+                user = %user, 
+                ip = %peer_addr.ip(),
+                reason = %reason,
+                "IP limit exceeded"
+            );
+            return Err(ProxyError::ConnectionLimitExceeded {
+                user: user.to_string(),
+            });
+        }
+
         if let Some(limit) = config.access.user_max_tcp_conns.get(user) {
             if stats.get_user_curr_connects(user) >= *limit as u64 {
                 return Err(ProxyError::ConnectionLimitExceeded {