README.md

@@ -38,14 +38,13 @@ https://github.com/m1ngsama/TNT/releases
 ```sh
 tnt              # default port 2222
 tnt -p 3333      # custom port
-tnt -d /var/lib/tnt
 PORT=3333 tnt    # via env var
 ```
 
 ### Connecting
 
 ```sh
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 localhost
 ```
 
 **Anonymous access by default**: Users can connect with ANY username/password (or empty password). No SSH keys required. Perfect for public chat servers.
@@ -93,12 +92,6 @@ TNT_BIND_ADDR=127.0.0.1 tnt
 
 # Bind to specific IP
 TNT_BIND_ADDR=192.168.1.100 tnt
-
-# Store host key and logs in an explicit state directory
-TNT_STATE_DIR=/var/lib/tnt tnt
-
-# Show the public SSH endpoint in startup logs
-TNT_PUBLIC_HOST=chat.m1ng.space tnt
 ```
 
 **Rate limiting:**
@@ -106,13 +99,10 @@ TNT_PUBLIC_HOST=chat.m1ng.space tnt
 # Max total connections (default 64)
 TNT_MAX_CONNECTIONS=100 tnt
 
-# Max concurrent sessions per IP (default 5)
+# Max connections per IP (default 5)
 TNT_MAX_CONN_PER_IP=10 tnt
 
-# Max new connection attempts per IP in 60 seconds (default 10)
+# Disable rate limiting (testing only)
-TNT_MAX_CONN_RATE_PER_IP=30 tnt
-
-# Disable connection-rate and auth-failure blocking (testing only)
 TNT_RATE_LIMIT=0 tnt
 ```
 
@@ -127,24 +117,11 @@ TNT_SSH_LOG_LEVEL=3 tnt
 TNT_ACCESS_TOKEN="strong-password-123" \
 TNT_BIND_ADDR=0.0.0.0 \
 TNT_MAX_CONNECTIONS=200 \
-TNT_MAX_CONN_PER_IP=30 \
+TNT_MAX_CONN_PER_IP=3 \
-TNT_MAX_CONN_RATE_PER_IP=60 \
 TNT_SSH_LOG_LEVEL=1 \
 tnt -p 2222
 ```
 
-### SSH Exec Interface
-
-TNT also exposes a small non-interactive SSH surface for scripts:
-
-```sh
-ssh -p 2222 chat.m1ng.space health
-ssh -p 2222 chat.m1ng.space stats --json
-ssh -p 2222 chat.m1ng.space users
-ssh -p 2222 chat.m1ng.space "tail -n 20"
-ssh -p 2222 operator@chat.m1ng.space post "service notice"
-```
-
 ## Development
 
 ### Building
@@ -167,7 +144,6 @@ cd tests
 ./test_basic.sh              # basic functionality
 ./test_security_features.sh  # security features
 ./test_anonymous_access.sh   # anonymous access
-./test_connection_limits.sh  # per-IP concurrency and rate limits
 ./test_stress.sh             # stress test
 ```
 
@@ -226,19 +202,6 @@ sudo cp tnt.service /etc/systemd/system/
 sudo systemctl daemon-reload
 sudo systemctl enable tnt
 sudo systemctl start tnt
-
-# Optional: override defaults without editing the unit
-sudo tee /etc/default/tnt >/dev/null <<'EOF'
-PORT=2222
-TNT_BIND_ADDR=0.0.0.0
-TNT_STATE_DIR=/var/lib/tnt
-TNT_MAX_CONNECTIONS=200
-TNT_MAX_CONN_PER_IP=30
-TNT_MAX_CONN_RATE_PER_IP=60
-TNT_RATE_LIMIT=1
-TNT_SSH_LOG_LEVEL=0
-TNT_PUBLIC_HOST=chat.m1ng.space
-EOF
 ```
 
 ### Docker
@@ -265,7 +228,6 @@ tnt.service     - systemd service unit
 
 - [Development Guide](https://github.com/m1ngsama/TNT/wiki/Development-Guide) - Complete development manual
 - [Quick Setup](docs/EASY_SETUP.md) - 5-minute deployment guide
-- [Roadmap](docs/ROADMAP.md) - Long-term Unix/GNU direction and next stages
 - [Security Reference](docs/SECURITY_QUICKREF.md) - Security config quick reference
 - [Contributing](docs/CONTRIBUTING.md) - How to contribute
 - [Changelog](docs/CHANGELOG.md) - Version history

docs/ANONYMOUS_ACCESS_SUMMARY.md

@@ -47,7 +47,7 @@
 **用户体验：**
 ```bash
 # 用户连接（零配置）
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 your.server.ip
 # 输入任意内容或直接按回车
 # 开始聊天！
 ```
@@ -143,7 +143,7 @@ ssh -p 2222 chat.m1ng.space
 tnt
 
 # 用户端（任何人）
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 server.ip
 # 输入任何内容作为密码或直接回车
 # 选择显示名称（可留空）
 # 开始聊天！
@@ -164,12 +164,9 @@ TNT_ACCESS_TOKEN="secret" tnt
 # 限制连接数
 TNT_MAX_CONNECTIONS=100 tnt
 
-# Limit concurrent sessions per IP
+# 限制每IP连接数
 TNT_MAX_CONN_PER_IP=10 tnt
 
-# Limit new connections per IP per 60 seconds
-TNT_MAX_CONN_RATE_PER_IP=30 tnt
-
 # 只允许本地访问
 TNT_BIND_ADDR=127.0.0.1 tnt
 ```

docs/CHANGELOG.md

@@ -1,24 +1,5 @@
 # Changelog
 
-## 2026-03-10 - SSH Runtime & Unix Interface Update
-
-### Fixed
-- moved SSH handshake/auth/channel setup out of the main accept loop
-- replaced synchronous room-wide fan-out with room update sequencing and per-client refresh
-- switched idle session handling to `ssh_channel_poll_timeout()` plus blocking reads so quiet sessions are not dropped incorrectly
-- made `-d/--state-dir` create the runtime state directory automatically
-
-### Added
-- SSH exec commands: `help`, `health`, `users`, `stats --json`, `tail`, `post`
-- PTY window-change handling for terminal resize
-- `TNT_MAX_CONN_RATE_PER_IP` for per-IP connection-rate control
-- `tests/test_exec_mode.sh`
-- `tests/test_connection_limits.sh`
-
-### Changed
-- `TNT_MAX_CONN_PER_IP` now means concurrent sessions per IP
-- stress tests now disable rate-based blocking so they exercise concurrency instead of self-throttling
-
 ## 2026-01-22 - Security Audit Fixes
 
 Comprehensive security hardening addressing 23 identified vulnerabilities across 6 categories.

docs/DEPLOYMENT.md

@@ -33,6 +33,8 @@ sudo mv tnt-darwin-arm64 /usr/local/bin/tnt
 1. Create user and directory:
 ```bash
 sudo useradd -r -s /bin/false tnt
+sudo mkdir -p /var/lib/tnt
+sudo chown tnt:tnt /var/lib/tnt
 ```
 
 2. Install service file:
@@ -43,24 +45,7 @@ sudo systemctl enable tnt
 sudo systemctl start tnt
 ```
 
-3. Optional runtime overrides:
+3. Check status:
-```bash
-sudo tee /etc/default/tnt >/dev/null <<'EOF'
-PORT=2222
-TNT_BIND_ADDR=0.0.0.0
-TNT_STATE_DIR=/var/lib/tnt
-TNT_MAX_CONNECTIONS=200
-TNT_MAX_CONN_PER_IP=30
-TNT_MAX_CONN_RATE_PER_IP=60
-TNT_RATE_LIMIT=1
-TNT_SSH_LOG_LEVEL=0
-TNT_PUBLIC_HOST=chat.m1ng.space
-EOF
-
-sudo systemctl restart tnt
-```
-
-4. Check status:
 ```bash
 sudo systemctl status tnt
 sudo journalctl -u tnt -f
@@ -79,16 +64,6 @@ Environment="PORT=3333"
 sudo systemctl restart tnt
 ```
 
-The service uses `StateDirectory=tnt`, so systemd creates `/var/lib/tnt` automatically.
-Use `TNT_STATE_DIR` or `tnt -d DIR` when running outside systemd to avoid depending on the current working directory.
-
-Recommended interpretation:
-
-- `TNT_MAX_CONNECTIONS`: global connection ceiling
-- `TNT_MAX_CONN_PER_IP`: concurrent sessions allowed from one IP
-- `TNT_MAX_CONN_RATE_PER_IP`: new connection attempts allowed per IP per 60 seconds
-- `TNT_RATE_LIMIT=0`: disables rate-based blocking and auth-failure IP blocking, but not the explicit capacity limits
-
 ## Firewall
 
 ```bash

docs/EASY_SETUP.md

@@ -25,7 +25,7 @@ tnt              # 监听 2222 端口
 用户只需要一个SSH客户端即可，无需任何配置：
 
 ```bash
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 your.server.ip
 ```
 
 **重要提示**：
@@ -125,7 +125,7 @@ That's it! Your server is now running.
 Users only need an SSH client, no configuration required:
 
 ```bash
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 your.server.ip
 ```
 
 **Important**:
@@ -181,12 +181,9 @@ PORT=3333 tnt
 # Limit max connections
 TNT_MAX_CONNECTIONS=100 tnt
 
-# Limit concurrent sessions per IP
+# Limit connections per IP
 TNT_MAX_CONN_PER_IP=10 tnt
 
-# Limit new connections per IP per 60 seconds
-TNT_MAX_CONN_RATE_PER_IP=30 tnt
-
 # Bind to localhost only
 TNT_BIND_ADDR=127.0.0.1 tnt
 
@@ -216,7 +213,7 @@ TNT_ACCESS_TOKEN="your_secret_password" tnt
 tnt
 
 # 用户连接（从任何机器）
-ssh -p 2222 chat.m1ng.space
+ssh -p 2222 chat.example.com
 # 输入任意密码或直接回车
 # 输入显示名称或留空
 # 开始聊天！

docs/IMPLEMENTATION_SUMMARY.txt

@@ -59,10 +59,10 @@ Branch 4: fix/resource-management (Medium Priority)
 Branch 5: fix/auth-protection (Critical Priority)
 --------------------------------------------------
 ✅ Add optional access token (TNT_ACCESS_TOKEN)
-✅ IP-based connection-rate limiting (10 new conn/IP/60s)
+✅ IP-based rate limiting (10 conn/IP/60s)
 ✅ Auth failure tracking (5 failures → 5 min block)
-✅ Connection counting (total, per-IP active sessions, per-IP recent attempts)
+✅ Connection counting (total and per-IP)
-✅ Configurable limits (TNT_MAX_CONNECTIONS, TNT_MAX_CONN_PER_IP, TNT_MAX_CONN_RATE_PER_IP)
+✅ Configurable limits (TNT_MAX_CONNECTIONS, TNT_MAX_CONN_PER_IP)
 ✅ Rate limit toggle (TNT_RATE_LIMIT)
 
 Branch 6: fix/concurrency-safety (High Priority)
@@ -84,8 +84,7 @@ TNT_BIND_ADDR         - Configurable bind address (default: 0.0.0.0)
 TNT_SSH_LOG_LEVEL     - SSH logging verbosity 0-4 (default: 1)
 TNT_RATE_LIMIT        - Enable/disable rate limiting (default: 1)
 TNT_MAX_CONNECTIONS   - Global connection limit (default: 64)
-TNT_MAX_CONN_PER_IP   - Concurrent sessions allowed per IP (default: 5)
+TNT_MAX_CONN_PER_IP   - Per-IP connection limit (default: 5)
-TNT_MAX_CONN_RATE_PER_IP - New connections allowed per IP per 60s (default: 10)
 
 Security Enhancements:
 ---------------------

docs/ROADMAP.md

@@ -1,99 +0,0 @@
-# Roadmap
-
-TNT is moving toward a durable Unix-style utility: a small, predictable tool with a stable interface, explicit configuration, scriptable output, and operationally simple deployment.
-
-This roadmap is intentionally strict. Each stage should leave the project easier to reason about, easier to automate, and safer to operate.
-
-## Design Principles
-
-- Keep the default path simple: install, run, connect.
-- Treat non-interactive interfaces as first-class, not as an afterthought to the TUI.
-- Prefer explicit flags, stable exit codes, and machine-readable output over implicit behavior.
-- Keep daemon concerns separate from control-plane concerns.
-- Make failure modes observable and testable.
-- Preserve the Vim-style interactive experience without coupling it to core server semantics.
-
-## Stage 1: Interface Contract
-
-Goal: make TNT predictable for operators, scripts, and package maintainers.
-
-- split the current surface into `tntd` (daemon) and `tntctl` (control client)
-- keep SSH exec support, but treat it as a transport for stable commands rather than the primary API shape
-- define stable subcommands and exit codes for:
-  - `health`
-  - `stats`
-  - `users`
-  - `tail`
-  - `post`
-- support text and JSON output modes where machine use is likely
-- normalize command parsing, help text, and error reporting
-- add `--bind`, `--port`, `--state-dir`, `--public-host`, `--max-clients`, and related long options consistently
-- add a man page for `tntd` and `tntctl`
-
-## Stage 2: Runtime Model
-
-Goal: make long-running operation boring and reliable.
-
-- move client state to a clearer ownership model with one release path
-- finish replacing ad hoc cross-thread UI mutation with per-client event delivery
-- add bounded outbound queues so slow clients cannot stall other users
-- separate accept, session bootstrap, interactive I/O, and persistence concerns more cleanly
-- make room/client capacity fully runtime-configurable with no hidden compile-time ceiling
-- document hard guarantees and soft limits
-
-## Stage 3: Data and Persistence
-
-Goal: make stored history durable, inspectable, and recoverable.
-
-- formalize the message log format and version it
-- keep timestamps in a timezone-safe format throughout write and replay
-- validate persisted UTF-8 and record structure before replay
-- add log rotation and compaction tooling
-- provide an offline inspection/export command
-- define recovery behavior for truncated or partially corrupted logs
-
-## Stage 4: Interactive UX
-
-Goal: keep the interface efficient for terminal users without sacrificing simplicity.
-
-- keep the current modal editing model, but make its behavior precise and documented
-- support resize, cursor movement, command history, and predictable paste behavior
-- add useful chat commands with clear semantics:
-  - `/nick`
-  - `/me`
-  - `/last N`
-  - `/search`
-  - `/mute-joins`
-- improve discoverability of NORMAL and COMMAND mode actions
-- make status lines and help output concise enough for small terminals
-
-## Stage 5: Operations and Security
-
-Goal: make public deployment manageable.
-
-- provide clear distinction between concurrent session limits and connection-rate limits
-- add admin-only controls for read-only mode, mute, and ban
-- expose a minimal health and stats surface suitable for monitoring
-- support systemd-friendly readiness and watchdog behavior
-- document recommended production defaults for public, private, and localhost-only deployments
-- tighten CI around authentication, limits, and restart behavior
-
-## Stage 6: Release Quality
-
-Goal: make regressions harder to introduce.
-
-- expand CI coverage across Linux and macOS for build and smoke tests
-- add sanitizer jobs and targeted fuzzing for UTF-8, log parsing, and command parsing
-- add soak tests for long-lived sessions and slow-client behavior
-- keep deployment and test docs aligned with actual runtime behavior
-- require every user-visible interface change to update docs and tests in the same change set
-
-## Immediate Next Tasks
-
-These are the next changes that should happen before new feature work expands the surface area.
-
-1. Introduce `tntctl` and move stable command handling behind it.
-2. Define exit codes and JSON schemas for `health`, `stats`, `users`, `tail`, and `post`.
-3. Add per-client outbound queues and finish untangling client-state ownership.
-4. Remove the remaining hidden runtime limits and make them explicit configuration.
-5. Add a long-running soak test that exercises idle sessions, reconnects, and slow consumers.

docs/SECURITY_QUICKREF.md

@@ -26,8 +26,7 @@ Connect: `sshpass -p "YourSecretPassword" ssh -p 2222 localhost`
 | `TNT_SSH_LOG_LEVEL` | `1` | SSH logging (0-4) | `TNT_SSH_LOG_LEVEL=3` |
 | `TNT_RATE_LIMIT` | `1` | Rate limiting on/off | `TNT_RATE_LIMIT=0` |
 | `TNT_MAX_CONNECTIONS` | `64` | Total connection limit | `TNT_MAX_CONNECTIONS=100` |
-| `TNT_MAX_CONN_PER_IP` | `5` | Concurrent sessions per IP | `TNT_MAX_CONN_PER_IP=3` |
+| `TNT_MAX_CONN_PER_IP` | `5` | Per-IP limit | `TNT_MAX_CONN_PER_IP=3` |
-| `TNT_MAX_CONN_RATE_PER_IP` | `10` | New connections per IP per 60s | `TNT_MAX_CONN_RATE_PER_IP=20` |
 
 ---
 
@@ -76,8 +75,7 @@ TNT_MAX_CONN_PER_IP=2 \
 ## Rate Limiting
 
 ### Defaults
-- **Concurrent Sessions:** 5 per IP
+- **Connection Rate:** 10 connections per IP per 60 seconds
-- **Connection Rate:** 10 new connections per IP per 60 seconds
 - **Auth Failures:** 5 failures → 5 minute IP block
 - **Window:** 60 second rolling window
 
@@ -112,12 +110,6 @@ TNT_MAX_CONN_PER_IP=3 ./tnt
 ```
 Each IP can have max 3 concurrent connections.
 
-### Per-IP Rate Limit
-```bash
-TNT_MAX_CONN_RATE_PER_IP=20 ./tnt
-```
-Each IP can open at most 20 new connections per 60 seconds before being temporarily blocked.
-
 ### Combined Example
 ```bash
 TNT_MAX_CONNECTIONS=100 TNT_MAX_CONN_PER_IP=10 ./tnt

docs/TEST_RESULTS.md

@@ -75,8 +75,8 @@
 | **Crypto** | RSA Key Size | 4096-bit (upgraded from 2048) | ✅ |
 | **Crypto** | Key Permissions | Atomic generation with 0600 perms | ✅ |
 | **Auth** | Access Token | Optional password protection | ✅ |
-| **Auth** | Rate Limiting | Per-IP connection-rate throttling | ✅ |
+| **Auth** | Rate Limiting | IP-based connection throttling | ✅ |
-| **Auth** | Connection Limits | Global and per-IP concurrent session limits | ✅ |
+| **Auth** | Connection Limits | Global and per-IP limits | ✅ |
 | **Input** | Username Validation | Shell metacharacter rejection | ✅ |
 | **Input** | Log Sanitization | Pipe/newline replacement | ✅ |
 | **Input** | UTF-8 Validation | Overlong encoding prevention | ✅ |
@@ -114,10 +114,9 @@ TNT_BIND_ADDR=127.0.0.1 ./tnt
 
 ### Strict Limits
 ```bash
-TNT_MAX_CONNECTIONS=10 TNT_MAX_CONN_PER_IP=2 TNT_MAX_CONN_RATE_PER_IP=10 ./tnt
+TNT_MAX_CONNECTIONS=10 TNT_MAX_CONN_PER_IP=2 ./tnt
 # Max 10 total connections
-# Max 2 concurrent sessions per IP address
+# Max 2 connections per IP address
-# Max 10 new connections per IP per 60 seconds
 ```
 
 ### Disabled Rate Limiting (Testing)
@@ -156,7 +155,7 @@ gcc -fsanitize=thread -g -O1 -c src/chat_room.c
 
 ## Known Limitations
 
-1. **Exec Surface Is Minimal:** The SSH exec interface is intentionally small and currently focused on operational commands
+1. **Interactive Only:** Server requires PTY sessions (no command execution via SSH)
 2. **libssh Deprecations:** Uses deprecated PTY width/height functions (4 warnings)
 3. **UTF-8 Unit Test:** Skipped in automated tests (requires manual compilation)
 
@@ -166,7 +165,7 @@ gcc -fsanitize=thread -g -O1 -c src/chat_room.c
 
 ✅ **All 23 security vulnerabilities fixed and verified**
 
-✅ **100% security-suite pass rate** (12/12 tests)
+✅ **100% test pass rate** (10/10 tests)
 
 ✅ **Backward compatible** - server remains open by default
 

include/chat_room.h

@@ -15,7 +15,6 @@ typedef struct {
     int client_capacity;
     message_t *messages;
     int message_count;
-    uint64_t update_seq;
 } chat_room_t;
 
 /* Global chat room instance */
@@ -48,7 +47,4 @@ int room_get_message_count(chat_room_t *room);
 /* Get online client count */
 int room_get_client_count(chat_room_t *room);
 
-/* Get room update sequence */
-uint64_t room_get_update_seq(chat_room_t *room);
-
 #endif /* CHAT_ROOM_H */

include/common.h

@@ -7,7 +7,6 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <time.h>
-#include <limits.h>
 #include <pthread.h>
 
 /* Project Metadata */
@@ -18,11 +17,9 @@
 #define MAX_MESSAGES 100
 #define MAX_USERNAME_LEN 64
 #define MAX_MESSAGE_LEN 1024
-#define MAX_EXEC_COMMAND_LEN 1024
 #define MAX_CLIENTS 64
 #define LOG_FILE "messages.log"
 #define HOST_KEY_FILE "host_key"
-#define TNT_DEFAULT_STATE_DIR "."
 
 /* ANSI color codes */
 #define ANSI_RESET "\033[0m"
@@ -46,9 +43,4 @@ typedef enum {
     LANG_ZH
 } help_lang_t;
 
-/* Runtime helpers */
-const char* tnt_state_dir(void);
-int tnt_ensure_state_dir(void);
-int tnt_state_path(char *buffer, size_t buf_size, const char *filename);
-
 #endif /* COMMON_H */

include/ssh_server.h

@@ -3,7 +3,6 @@
 
 #include "common.h"
 #include "chat_room.h"
-#include <arpa/inet.h>
 #include <libssh/libssh.h>
 #include <libssh/server.h>
 
@@ -13,7 +12,6 @@ typedef struct client {
     ssh_session session;             /* SSH session */
     ssh_channel channel;             /* SSH channel */
     char username[MAX_USERNAME_LEN];
-    char client_ip[INET6_ADDRSTRLEN];
     int width;
     int height;
     client_mode_t mode;
@@ -23,15 +21,11 @@ typedef struct client {
     bool show_help;
     char command_input[256];
     char command_output[2048];
-    char exec_command[MAX_EXEC_COMMAND_LEN];
+    char exec_command[256];
-    char ssh_login[MAX_USERNAME_LEN];
-    bool redraw_pending;
     pthread_t thread;
     bool connected;
     int ref_count;                   /* Reference count for safe cleanup */
     pthread_mutex_t ref_lock;        /* Lock for ref_count */
-    pthread_mutex_t io_lock;         /* Serialize SSH channel writes */
-    struct ssh_channel_callbacks_struct *channel_cb;
 } client_t;
 
 /* Initialize SSH server */
@@ -49,8 +43,4 @@ int client_send(client_t *client, const char *data, size_t len);
 /* Send formatted string to client */
 int client_printf(client_t *client, const char *fmt, ...);
 
-/* Reference counting helpers */
-void client_addref(client_t *client);
-void client_release(client_t *client);
-
 #endif /* SSH_SERVER_H */

include/utf8.h

@@ -30,7 +30,4 @@ void utf8_remove_last_word(char *str);
 /* Validate a UTF-8 byte sequence */
 bool utf8_is_valid_sequence(const char *bytes, int len);
 
-/* Validate an entire NUL-terminated UTF-8 string */
-bool utf8_is_valid_string(const char *str);
-
 #endif /* UTF8_H */

src/chat_room.c

@@ -1,23 +1,11 @@
 #include "chat_room.h"
+#include "ssh_server.h"
+#include "tui.h"
+#include <unistd.h>
 
 /* Global chat room instance */
 chat_room_t *g_room = NULL;
 
-static int room_capacity_from_env(void) {
-    const char *env = getenv("TNT_MAX_CONNECTIONS");
-
-    if (!env || env[0] == '\0') {
-        return MAX_CLIENTS;
-    }
-
-    int capacity = atoi(env);
-    if (capacity < 1 || capacity > 1024) {
-        return MAX_CLIENTS;
-    }
-
-    return capacity;
-}
-
 /* Initialize chat room */
 chat_room_t* room_create(void) {
     chat_room_t *room = calloc(1, sizeof(chat_room_t));
@@ -25,8 +13,8 @@ chat_room_t* room_create(void) {
 
     pthread_rwlock_init(&room->lock, NULL);
 
-    room->client_capacity = room_capacity_from_env();
+    room->client_capacity = MAX_CLIENTS;
-    room->clients = calloc(room->client_capacity, sizeof(struct client *));
+    room->clients = calloc(room->client_capacity, sizeof(client_t*));
     if (!room->clients) {
         free(room);
         return NULL;
@@ -54,7 +42,7 @@ void room_destroy(chat_room_t *room) {
 }
 
 /* Add client to room */
-int room_add_client(chat_room_t *room, struct client *client) {
+int room_add_client(chat_room_t *room, client_t *client) {
     pthread_rwlock_wrlock(&room->lock);
 
     if (room->client_count >= room->client_capacity) {
@@ -69,7 +57,7 @@ int room_add_client(chat_room_t *room, struct client *client) {
 }
 
 /* Remove client from room */
-void room_remove_client(chat_room_t *room, struct client *client) {
+void room_remove_client(chat_room_t *room, client_t *client) {
     pthread_rwlock_wrlock(&room->lock);
 
     for (int i = 0; i < room->client_count; i++) {
@@ -92,9 +80,69 @@ void room_broadcast(chat_room_t *room, const message_t *msg) {
 
     /* Add to history */
     room_add_message(room, msg);
-    room->update_seq++;
+
+    /* Get copy of client list and increment ref counts */
+    int count = room->client_count;
+    if (count == 0) {
+        pthread_rwlock_unlock(&room->lock);
+        return;
+    }
+    client_t **clients_copy = calloc(count, sizeof(client_t*));
+    if (!clients_copy) {
+        pthread_rwlock_unlock(&room->lock);
+        return;
+    }
+    memcpy(clients_copy, room->clients, count * sizeof(client_t*));
+
+    /* Increment reference count for each client */
+    for (int i = 0; i < count; i++) {
+        pthread_mutex_lock(&clients_copy[i]->ref_lock);
+        clients_copy[i]->ref_count++;
+        pthread_mutex_unlock(&clients_copy[i]->ref_lock);
+    }
 
     pthread_rwlock_unlock(&room->lock);
+
+    /* Render to each client (outside of lock) */
+    for (int i = 0; i < count; i++) {
+        client_t *client = clients_copy[i];
+
+        /* Check client state before rendering (while holding ref) */
+        bool should_render = false;
+        pthread_mutex_lock(&client->ref_lock);
+        if (client->ref_count > 0) {
+            should_render = client->connected &&
+                          !client->show_help &&
+                          client->command_output[0] == '\0';
+        }
+        pthread_mutex_unlock(&client->ref_lock);
+
+        if (should_render) {
+            tui_render_screen(client);
+        }
+
+        /* Decrement reference count and free if needed */
+        pthread_mutex_lock(&client->ref_lock);
+        client->ref_count--;
+        int ref = client->ref_count;
+        pthread_mutex_unlock(&client->ref_lock);
+
+        if (ref == 0) {
+            /* Safe to free now */
+            if (client->channel) {
+                ssh_channel_close(client->channel);
+                ssh_channel_free(client->channel);
+            }
+            if (client->session) {
+                ssh_disconnect(client->session);
+                ssh_free(client->session);
+            }
+            pthread_mutex_destroy(&client->ref_lock);
+            free(client);
+        }
+    }
+
+    free(clients_copy);
 }
 
 /* Add message to room history */
@@ -139,13 +187,3 @@ int room_get_client_count(chat_room_t *room) {
     pthread_rwlock_unlock(&room->lock);
     return count;
 }
-
-uint64_t room_get_update_seq(chat_room_t *room) {
-    uint64_t seq;
-
-    pthread_rwlock_rdlock(&room->lock);
-    seq = room->update_seq;
-    pthread_rwlock_unlock(&room->lock);
-
-    return seq;
-}

src/common.c

@@ -1,86 +0,0 @@
-#include "common.h"
-#include <errno.h>
-#include <sys/stat.h>
-
-#ifndef PATH_MAX
-#define PATH_MAX 4096
-#endif
-
-const char* tnt_state_dir(void) {
-    const char *dir = getenv("TNT_STATE_DIR");
-
-    if (!dir || dir[0] == '\0') {
-        return TNT_DEFAULT_STATE_DIR;
-    }
-
-    return dir;
-}
-
-int tnt_ensure_state_dir(void) {
-    const char *dir = tnt_state_dir();
-    char path[PATH_MAX];
-    struct stat st;
-    size_t len;
-
-    if (!dir || dir[0] == '\0') {
-        return -1;
-    }
-
-    if (strcmp(dir, ".") == 0 || strcmp(dir, "/") == 0) {
-        return 0;
-    }
-
-    if (snprintf(path, sizeof(path), "%s", dir) >= (int)sizeof(path)) {
-        return -1;
-    }
-
-    len = strlen(path);
-    while (len > 1 && path[len - 1] == '/') {
-        path[len - 1] = '\0';
-        len--;
-    }
-
-    for (char *p = path + 1; *p; p++) {
-        if (*p != '/') {
-            continue;
-        }
-        *p = '\0';
-        if (mkdir(path, 0700) < 0 && errno != EEXIST) {
-            return -1;
-        }
-        *p = '/';
-    }
-
-    if (mkdir(path, 0700) < 0 && errno != EEXIST) {
-        return -1;
-    }
-
-    if (stat(path, &st) != 0 || !S_ISDIR(st.st_mode)) {
-        return -1;
-    }
-
-    return 0;
-}
-
-int tnt_state_path(char *buffer, size_t buf_size, const char *filename) {
-    const char *dir;
-    int written;
-
-    if (!buffer || buf_size == 0 || !filename || filename[0] == '\0') {
-        return -1;
-    }
-
-    dir = tnt_state_dir();
-
-    if (strcmp(dir, "/") == 0) {
-        written = snprintf(buffer, buf_size, "/%s", filename);
-    } else {
-        written = snprintf(buffer, buf_size, "%s/%s", dir, filename);
-    }
-
-    if (written < 0 || (size_t)written >= buf_size) {
-        return -1;
-    }
-
-    return 0;
-}

src/main.c

@@ -11,54 +11,40 @@
 static void signal_handler(int sig) {
     (void)sig;
     static const char msg[] = "\nShutting down...\n";
-    ssize_t ignored = write(STDERR_FILENO, msg, sizeof(msg) - 1);
+    (void)write(STDERR_FILENO, msg, sizeof(msg) - 1);
-    (void)ignored;
     _exit(0);
 }
 
 int main(int argc, char **argv) {
     int port = DEFAULT_PORT;
 
-    /* Environment provides defaults; command-line flags override it. */
-    const char *port_env = getenv("PORT");
-    if (port_env) {
-        port = atoi(port_env);
-    }
-
     /* Parse command line arguments */
     for (int i = 1; i < argc; i++) {
         if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
             port = atoi(argv[i + 1]);
             i++;
-        } else if ((strcmp(argv[i], "-d") == 0 ||
-                    strcmp(argv[i], "--state-dir") == 0) && i + 1 < argc) {
-            if (setenv("TNT_STATE_DIR", argv[i + 1], 1) != 0) {
-                perror("setenv TNT_STATE_DIR");
-                return 1;
-            }
-            i++;
         } else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0) {
             printf("TNT - Terminal Network Talk\n");
             printf("Usage: %s [options]\n", argv[0]);
             printf("Options:\n");
             printf("  -p PORT    Listen on PORT (default: %d)\n", DEFAULT_PORT);
-            printf("  -d DIR     Store host key and logs in DIR\n");
             printf("  -h         Show this help\n");
             return 0;
         }
     }
 
+    /* Check environment variable for port */
+    const char *port_env = getenv("PORT");
+    if (port_env) {
+        port = atoi(port_env);
+    }
+
     /* Setup signal handlers */
     signal(SIGINT, signal_handler);
     signal(SIGTERM, signal_handler);
     signal(SIGPIPE, SIG_IGN);
 
     /* Initialize subsystems */
-    if (tnt_ensure_state_dir() < 0) {
-        fprintf(stderr, "Failed to create state directory: %s\n", tnt_state_dir());
-        return 1;
-    }
-
     message_init();
 
     /* Create chat room */

src/message.c

@@ -3,50 +3,6 @@
 #include <unistd.h>
 #include <fcntl.h>
 
-static pthread_mutex_t g_message_file_lock = PTHREAD_MUTEX_INITIALIZER;
-
-static time_t parse_rfc3339_utc(const char *timestamp_str) {
-    struct tm tm = {0};
-    char *result;
-    char *old_tz = NULL;
-    time_t parsed;
-
-    if (!timestamp_str) {
-        return (time_t)-1;
-    }
-
-    result = strptime(timestamp_str, "%Y-%m-%dT%H:%M:%SZ", &tm);
-    if (!result || *result != '\0') {
-        return (time_t)-1;
-    }
-
-    const char *tz = getenv("TZ");
-    if (tz) {
-        old_tz = strdup(tz);
-        if (!old_tz) {
-            return (time_t)-1;
-        }
-    }
-
-    if (setenv("TZ", "UTC0", 1) != 0) {
-        free(old_tz);
-        return (time_t)-1;
-    }
-    tzset();
-
-    parsed = mktime(&tm);
-
-    if (old_tz) {
-        setenv("TZ", old_tz, 1);
-        free(old_tz);
-    } else {
-        unsetenv("TZ");
-    }
-    tzset();
-
-    return parsed;
-}
-
 /* Initialize message subsystem */
 void message_init(void) {
     /* Nothing to initialize for now */
@@ -54,20 +10,13 @@ void message_init(void) {
 
 /* Load messages from log file - Optimized for large files */
 int message_load(message_t **messages, int max_messages) {
-    char log_path[PATH_MAX];
-
     /* Always allocate the message array */
     message_t *msg_array = calloc(max_messages, sizeof(message_t));
     if (!msg_array) {
         return 0;
     }
 
-    if (tnt_state_path(log_path, sizeof(log_path), LOG_FILE) < 0) {
+    FILE *fp = fopen(LOG_FILE, "r");
-        *messages = msg_array;
-        return 0;
-    }
-
-    FILE *fp = fopen(log_path, "r");
     if (!fp) {
         /* File doesn't exist yet, no messages */
         *messages = msg_array;
@@ -168,17 +117,15 @@ read_messages:;
             continue;
         }
 
-        if (!utf8_is_valid_string(username) || !utf8_is_valid_string(content)) {
+        /* Parse ISO 8601 timestamp */
-            continue;
+        struct tm tm = {0};
-        }
+        char *result = strptime(timestamp_str, "%Y-%m-%dT%H:%M:%S", &tm);
-
+        if (!result) {
-        /* Parse strict UTC RFC3339 timestamp */
-        time_t msg_time = parse_rfc3339_utc(timestamp_str);
-        if (msg_time == (time_t)-1) {
             continue;
         }
 
         /* Validate timestamp is reasonable (not in far future or past) */
+        time_t msg_time = mktime(&tm);
         time_t now = time(NULL);
         if (msg_time > now + 86400 || msg_time < now - 31536000 * 10) {
             continue;
@@ -199,18 +146,8 @@ read_messages:;
 
 /* Save a message to log file */
 int message_save(const message_t *msg) {
-    char log_path[PATH_MAX];
+    FILE *fp = fopen(LOG_FILE, "a");
-    int rc = 0;
-
-    if (tnt_state_path(log_path, sizeof(log_path), LOG_FILE) < 0) {
-        return -1;
-    }
-
-    pthread_mutex_lock(&g_message_file_lock);
-
-    FILE *fp = fopen(log_path, "a");
     if (!fp) {
-        pthread_mutex_unlock(&g_message_file_lock);
         return -1;
     }
 
@@ -243,14 +180,10 @@ int message_save(const message_t *msg) {
     }
 
     /* Write to file: timestamp|username|content */
-    if (fprintf(fp, "%s|%s|%s\n", timestamp, safe_username, safe_content) < 0 ||
+    fprintf(fp, "%s|%s|%s\n", timestamp, safe_username, safe_content);
-        fflush(fp) != 0) {
-        rc = -1;
-    }
 
     fclose(fp);
-    pthread_mutex_unlock(&g_message_file_lock);
+    return 0;
-    return rc;
 }
 
 /* Format a message for display */

src/tui.c

@@ -5,46 +5,6 @@
 #include <stdarg.h>
 #include <unistd.h>
 
-static void buffer_append_bytes(char *buffer, size_t buf_size, size_t *pos,
-                                const char *data, size_t len) {
-    size_t available;
-    size_t to_copy;
-
-    if (!buffer || !pos || !data || len == 0 || buf_size == 0 || *pos >= buf_size - 1) {
-        return;
-    }
-
-    available = (buf_size - 1) - *pos;
-    to_copy = (len < available) ? len : available;
-    memcpy(buffer + *pos, data, to_copy);
-    *pos += to_copy;
-    buffer[*pos] = '\0';
-}
-
-static void buffer_appendf(char *buffer, size_t buf_size, size_t *pos,
-                           const char *fmt, ...) {
-    va_list args;
-    int written;
-
-    if (!buffer || !pos || !fmt || buf_size == 0 || *pos >= buf_size - 1) {
-        return;
-    }
-
-    va_start(args, fmt);
-    written = vsnprintf(buffer + *pos, buf_size - *pos, fmt, args);
-    va_end(args);
-
-    if (written < 0) {
-        return;
-    }
-
-    if ((size_t)written >= buf_size - *pos) {
-        *pos = buf_size - 1;
-    } else {
-        *pos += (size_t)written;
-    }
-}
-
 /* Clear the screen */
 void tui_clear_screen(client_t *client) {
     if (!client || !client->connected) return;
@@ -61,8 +21,7 @@ void tui_render_screen(client_t *client) {
     const size_t buf_size = 65536;
     char *buffer = malloc(buf_size);
     if (!buffer) return;
-    size_t pos = 0;
+    int pos = 0;
-    buffer[0] = '\0';
 
     /* Acquire all data in one lock to prevent TOCTOU */
     pthread_rwlock_rdlock(&g_room->lock);
@@ -107,7 +66,7 @@ void tui_render_screen(client_t *client) {
     /* Now render using snapshot (no lock held) */
 
     /* Move to top (Home) - Do NOT clear screen to prevent flicker */
-    buffer_appendf(buffer, buf_size, &pos, ANSI_HOME);
+    pos += snprintf(buffer + pos, buf_size - pos, ANSI_HOME);
 
     /* Title bar */
     const char *mode_str = (client->mode == MODE_INSERT) ? "INSERT" :
@@ -123,44 +82,48 @@ void tui_render_screen(client_t *client) {
     int padding = client->width - title_width;
     if (padding < 0) padding = 0;
 
-    buffer_appendf(buffer, buf_size, &pos, ANSI_REVERSE "%s", title);
+    pos += snprintf(buffer + pos, buf_size - pos, ANSI_REVERSE "%s", title);
-    for (int i = 0; i < padding; i++) {
+    for (int i = 0; i < padding && pos < (int)buf_size - 4; i++) {
-        buffer_append_bytes(buffer, buf_size, &pos, " ", 1);
+        buffer[pos++] = ' ';
     }
-    buffer_appendf(buffer, buf_size, &pos, ANSI_RESET "\033[K\r\n");
+    pos += snprintf(buffer + pos, buf_size - pos, ANSI_RESET "\033[K\r\n");
 
     /* Render messages from snapshot */
     if (msg_snapshot) {
         for (int i = 0; i < snapshot_count; i++) {
             char msg_line[1024];
             message_format(&msg_snapshot[i], msg_line, sizeof(msg_line), client->width);
-            buffer_appendf(buffer, buf_size, &pos, "%s\033[K\r\n", msg_line);
+            pos += snprintf(buffer + pos, buf_size - pos, "%s\033[K\r\n", msg_line);
         }
         free(msg_snapshot);
     }
 
     /* Fill empty lines and clear them */
     for (int i = snapshot_count; i < msg_height; i++) {
-        buffer_appendf(buffer, buf_size, &pos, "\033[K\r\n");
+        pos += snprintf(buffer + pos, buf_size - pos, "\033[K\r\n");
     }
 
     /* Separator - use box drawing character */
-    for (int i = 0; i < client->width; i++) {
+    for (int i = 0; i < client->width && pos < (int)buf_size - 10; i++) {
-        buffer_append_bytes(buffer, buf_size, &pos, "─", strlen("─"));
+        const char *line_char = "─";  /* U+2500 box drawing, 3 bytes */
+        int len = strlen(line_char);
+        memcpy(buffer + pos, line_char, len);
+        pos += len;
     }
-    buffer_appendf(buffer, buf_size, &pos, "\033[K\r\n");
+    pos += snprintf(buffer + pos, buf_size - pos, "\033[K\r\n");
 
     /* Status/Input line */
     if (client->mode == MODE_INSERT) {
-        buffer_appendf(buffer, buf_size, &pos, "> \033[K");
+        pos += snprintf(buffer + pos, buf_size - pos, "> \033[K");
     } else if (client->mode == MODE_NORMAL) {
         int total = msg_count;
         int scroll_pos = client->scroll_pos + 1;
         if (total == 0) scroll_pos = 0;
-        buffer_appendf(buffer, buf_size, &pos,
+        pos += snprintf(buffer + pos, buf_size - pos,
                        "-- NORMAL -- (%d/%d)\033[K", scroll_pos, total);
     } else if (client->mode == MODE_COMMAND) {
-        buffer_appendf(buffer, buf_size, &pos, ":%s\033[K", client->command_input);
+        pos += snprintf(buffer + pos, buf_size - pos,
+                       ":%s\033[K", client->command_input);
     }
 
     client_send(client, buffer, pos);
@@ -207,11 +170,10 @@ void tui_render_command_output(client_t *client) {
     if (!client || !client->connected) return;
 
     char buffer[4096];
-    size_t pos = 0;
+    int pos = 0;
-    buffer[0] = '\0';
 
     /* Clear screen */
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_CLEAR ANSI_HOME);
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_CLEAR ANSI_HOME);
 
     /* Title */
     const char *title = " COMMAND OUTPUT ";
@@ -219,11 +181,11 @@ void tui_render_command_output(client_t *client) {
     int padding = client->width - title_width;
     if (padding < 0) padding = 0;
 
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_REVERSE "%s", title);
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_REVERSE "%s", title);
     for (int i = 0; i < padding; i++) {
-        buffer_append_bytes(buffer, sizeof(buffer), &pos, " ", 1);
+        buffer[pos++] = ' ';
     }
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_RESET "\r\n");
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_RESET "\r\n");
 
     /* Command output - use a copy to avoid strtok corruption */
     char output_copy[2048];
@@ -243,7 +205,7 @@ void tui_render_command_output(client_t *client) {
             utf8_truncate(truncated, client->width);
         }
 
-        buffer_appendf(buffer, sizeof(buffer), &pos, "%s\r\n", truncated);
+        pos += snprintf(buffer + pos, sizeof(buffer) - pos, "%s\r\n", truncated);
         line = strtok(NULL, "\n");
         line_count++;
     }
@@ -353,11 +315,10 @@ void tui_render_help(client_t *client) {
     if (!client || !client->connected) return;
 
     char buffer[8192];
-    size_t pos = 0;
+    int pos = 0;
-    buffer[0] = '\0';
 
     /* Clear screen */
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_CLEAR ANSI_HOME);
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_CLEAR ANSI_HOME);
 
     /* Title */
     const char *title = " HELP ";
@@ -365,11 +326,11 @@ void tui_render_help(client_t *client) {
     int padding = client->width - title_width;
     if (padding < 0) padding = 0;
 
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_REVERSE "%s", title);
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_REVERSE "%s", title);
     for (int i = 0; i < padding; i++) {
-        buffer_append_bytes(buffer, sizeof(buffer), &pos, " ", 1);
+        buffer[pos++] = ' ';
     }
-    buffer_appendf(buffer, sizeof(buffer), &pos, ANSI_RESET "\r\n");
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos, ANSI_RESET "\r\n");
 
     /* Help content */
     const char *help_text = tui_get_help_text(client->help_lang);
@@ -387,27 +348,27 @@ void tui_render_help(client_t *client) {
     }
 
     int content_height = client->height - 2;
-    if (content_height < 1) content_height = 1;
-    int max_scroll = line_count - content_height + 1;
-    if (max_scroll < 0) max_scroll = 0;
     int start = client->help_scroll_pos;
-    if (start > max_scroll) start = max_scroll;
     int end = start + content_height - 1;
     if (end > line_count) end = line_count;
 
     for (int i = start; i < end && (i - start) < content_height - 1; i++) {
-        buffer_appendf(buffer, sizeof(buffer), &pos, "%s\r\n", lines[i]);
+        pos += snprintf(buffer + pos, sizeof(buffer) - pos, "%s\r\n", lines[i]);
     }
 
     /* Fill remaining lines */
     for (int i = end - start; i < content_height - 1; i++) {
-        buffer_append_bytes(buffer, sizeof(buffer), &pos, "\r\n", 2);
+        buffer[pos++] = '\r';
+        buffer[pos++] = '\n';
     }
 
     /* Status line */
-    buffer_appendf(buffer, sizeof(buffer), &pos,
+    int max_scroll = line_count - content_height + 1;
+    if (max_scroll < 0) max_scroll = 0;
+
+    pos += snprintf(buffer + pos, sizeof(buffer) - pos,
                    "-- HELP -- (%d/%d) j/k:scroll g/G:top/bottom e/z:lang q:close",
-                   start + 1, max_scroll + 1);
+                   client->help_scroll_pos + 1, max_scroll + 1);
 
     client_send(client, buffer, pos);
 }

src/utf8.c

@@ -15,17 +15,6 @@ uint32_t utf8_decode(const char *str, int *bytes_read) {
     uint32_t codepoint = 0;
     int len = utf8_byte_length(s[0]);
 
-    if (len < 1 || len > 4) {
-        len = 1;
-    }
-
-    for (int i = 1; i < len; i++) {
-        if (s[i] == '\0') {
-            *bytes_read = 1;
-            return s[0];
-        }
-    }
-
     *bytes_read = len;
 
     switch (len) {
@@ -218,32 +207,3 @@ bool utf8_is_valid_sequence(const char *bytes, int len) {
 
     return true;
 }
-
-bool utf8_is_valid_string(const char *str) {
-    const unsigned char *p = (const unsigned char *)str;
-
-    if (!str) {
-        return false;
-    }
-
-    while (*p != '\0') {
-        int len = utf8_byte_length(*p);
-        if (len < 1 || len > 4) {
-            return false;
-        }
-
-        for (int i = 1; i < len; i++) {
-            if (p[i] == '\0') {
-                return false;
-            }
-        }
-
-        if (!utf8_is_valid_sequence((const char *)p, len)) {
-            return false;
-        }
-
-        p += len;
-    }
-
-    return true;
-}

tests/test_connection_limits.sh

@@ -1,135 +0,0 @@
-#!/bin/sh
-# Connection limit regression tests for TNT
-
-PORT=${PORT:-2222}
-BIN="../tnt"
-PASS=0
-FAIL=0
-STATE_DIR=$(mktemp -d "${TMPDIR:-/tmp}/tnt-limit-test.XXXXXX")
-SERVER_PID=""
-WATCHER_PID=""
-
-cleanup() {
-    if [ -n "$WATCHER_PID" ]; then
-        kill "$WATCHER_PID" 2>/dev/null || true
-        wait "$WATCHER_PID" 2>/dev/null || true
-    fi
-    if [ -n "$SERVER_PID" ]; then
-        kill "$SERVER_PID" 2>/dev/null || true
-        wait "$SERVER_PID" 2>/dev/null || true
-    fi
-    rm -rf "$STATE_DIR"
-}
-
-trap cleanup EXIT
-
-if [ ! -f "$BIN" ]; then
-    echo "Error: Binary $BIN not found. Run make first."
-    exit 1
-fi
-
-SSH_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o BatchMode=yes -p $PORT"
-
-wait_for_health() {
-    for _ in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15; do
-        if [ -n "$SERVER_PID" ] && ! kill -0 "$SERVER_PID" 2>/dev/null; then
-            return 1
-        fi
-        OUT=$(ssh $SSH_OPTS localhost health 2>/dev/null || true)
-        [ "$OUT" = "ok" ] && return 0
-        sleep 1
-    done
-    return 1
-}
-
-echo "=== TNT Connection Limit Tests ==="
-
-TNT_RATE_LIMIT=0 TNT_MAX_CONN_PER_IP=1 "$BIN" -p "$PORT" -d "$STATE_DIR" \
-    >"$STATE_DIR/concurrent.log" 2>&1 &
-SERVER_PID=$!
-
-if wait_for_health; then
-    echo "✓ server started for concurrent limit test"
-    PASS=$((PASS + 1))
-else
-    echo "✗ server failed to start for concurrent limit test"
-    exit 1
-fi
-
-WATCHER_READY="$STATE_DIR/watcher.ready"
-cat >"$STATE_DIR/watcher.expect" <<EOF
-set timeout 10
-spawn ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p $PORT watcher@localhost
-expect "请输入用户名"
-send "watcher\r"
-exec touch "$WATCHER_READY"
-sleep 8
-send "\003"
-expect eof
-EOF
-
-expect "$STATE_DIR/watcher.expect" >"$STATE_DIR/watcher.log" 2>&1 &
-WATCHER_PID=$!
-
-for _ in 1 2 3 4 5 6 7 8 9 10; do
-    [ -f "$WATCHER_READY" ] && break
-    sleep 1
-done
-
-if [ ! -f "$WATCHER_READY" ]; then
-    echo "✗ watcher session did not become ready"
-    sed -n '1,120p' "$STATE_DIR/watcher.log"
-    exit 1
-fi
-
-if ssh $SSH_OPTS localhost health >/dev/null 2>&1; then
-    echo "✗ concurrent per-IP limit was not enforced"
-    FAIL=$((FAIL + 1))
-else
-    echo "✓ concurrent per-IP limit rejects a second session"
-    PASS=$((PASS + 1))
-fi
-
-wait "$WATCHER_PID" 2>/dev/null || true
-WATCHER_PID=""
-kill "$SERVER_PID" 2>/dev/null || true
-wait "$SERVER_PID" 2>/dev/null || true
-SERVER_PID=""
-
-RATE_PORT=$((PORT + 1))
-SSH_RATE_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o BatchMode=yes -p $RATE_PORT"
-
-TNT_MAX_CONN_PER_IP=10 TNT_MAX_CONN_RATE_PER_IP=2 "$BIN" -p "$RATE_PORT" -d "$STATE_DIR" \
-    >"$STATE_DIR/rate.log" 2>&1 &
-SERVER_PID=$!
-
-sleep 2
-if kill -0 "$SERVER_PID" 2>/dev/null; then
-    echo "✓ server started for rate limit test"
-    PASS=$((PASS + 1))
-else
-    echo "✗ server failed to start for rate limit test"
-    sed -n '1,120p' "$STATE_DIR/rate.log"
-    exit 1
-fi
-
-R1=$(ssh $SSH_RATE_OPTS localhost health 2>/dev/null || true)
-R2=$(ssh $SSH_RATE_OPTS localhost health 2>/dev/null || true)
-if ssh $SSH_RATE_OPTS localhost health >/dev/null 2>&1; then
-    echo "✗ per-IP connection-rate limit was not enforced"
-    FAIL=$((FAIL + 1))
-else
-    if [ "$R1" = "ok" ] && [ "$R2" = "ok" ]; then
-        echo "✓ per-IP connection-rate limit blocks after the configured burst"
-        PASS=$((PASS + 1))
-    else
-        echo "✗ per-IP connection-rate limit setup failed unexpectedly"
-        FAIL=$((FAIL + 1))
-    fi
-fi
-
-echo ""
-echo "PASSED: $PASS"
-echo "FAILED: $FAIL"
-[ "$FAIL" -eq 0 ] && echo "All tests passed" || echo "Some tests failed"
-exit "$FAIL"

tests/test_exec_mode.sh

@@ -1,167 +0,0 @@
-#!/bin/sh
-# Exec-mode regression tests for TNT
-
-PORT=${PORT:-2222}
-PASS=0
-FAIL=0
-BIN="../tnt"
-STATE_DIR=$(mktemp -d "${TMPDIR:-/tmp}/tnt-exec-test.XXXXXX")
-INTERACTIVE_PID=""
-
-cleanup() {
-    if [ -n "${INTERACTIVE_PID}" ]; then
-        kill "${INTERACTIVE_PID}" 2>/dev/null || true
-        wait "${INTERACTIVE_PID}" 2>/dev/null || true
-    fi
-    kill "${SERVER_PID}" 2>/dev/null || true
-    wait "${SERVER_PID}" 2>/dev/null || true
-    rm -rf "${STATE_DIR}"
-}
-
-trap cleanup EXIT
-
-if [ ! -f "$BIN" ]; then
-    echo "Error: Binary $BIN not found. Run make first."
-    exit 1
-fi
-
-SSH_OPTS="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o BatchMode=yes -p $PORT"
-
-echo "=== TNT Exec Mode Tests ==="
-
-TNT_RATE_LIMIT=0 $BIN -p "$PORT" -d "$STATE_DIR" >"${STATE_DIR}/server.log" 2>&1 &
-SERVER_PID=$!
-
-HEALTH_OUTPUT=""
-for _ in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15; do
-    if ! kill -0 "$SERVER_PID" 2>/dev/null; then
-        echo "✗ Server failed to start"
-        exit 1
-    fi
-    HEALTH_OUTPUT=$(ssh $SSH_OPTS localhost health 2>/dev/null || true)
-    [ "$HEALTH_OUTPUT" = "ok" ] && break
-    sleep 1
-done
-
-if [ "$HEALTH_OUTPUT" = "ok" ]; then
-    echo "✓ health returns ok"
-    PASS=$((PASS + 1))
-else
-    echo "✗ health failed: $HEALTH_OUTPUT"
-    FAIL=$((FAIL + 1))
-fi
-
-STATS_OUTPUT=$(ssh $SSH_OPTS localhost stats 2>/dev/null || true)
-printf '%s\n' "$STATS_OUTPUT" | grep -q '^status ok$' &&
-printf '%s\n' "$STATS_OUTPUT" | grep -q '^online_users 0$'
-if [ $? -eq 0 ]; then
-    echo "✓ stats returns key/value output"
-    PASS=$((PASS + 1))
-else
-    echo "✗ stats output unexpected"
-    printf '%s\n' "$STATS_OUTPUT"
-    FAIL=$((FAIL + 1))
-fi
-
-STATS_JSON=$(ssh $SSH_OPTS localhost stats --json 2>/dev/null || true)
-printf '%s\n' "$STATS_JSON" | grep -q '"status":"ok"' &&
-printf '%s\n' "$STATS_JSON" | grep -q '"online_users":0'
-if [ $? -eq 0 ]; then
-    echo "✓ stats --json returns JSON"
-    PASS=$((PASS + 1))
-else
-    echo "✗ stats --json output unexpected"
-    printf '%s\n' "$STATS_JSON"
-    FAIL=$((FAIL + 1))
-fi
-
-POST_OUTPUT=$(ssh $SSH_OPTS execposter@localhost post "hello from exec" 2>/dev/null || true)
-if [ "$POST_OUTPUT" = "posted" ]; then
-    echo "✓ post publishes a message"
-    PASS=$((PASS + 1))
-else
-    echo "✗ post failed: $POST_OUTPUT"
-    FAIL=$((FAIL + 1))
-fi
-
-TAIL_OUTPUT=$(ssh $SSH_OPTS localhost "tail -n 1" 2>/dev/null || true)
-printf '%s\n' "$TAIL_OUTPUT" | grep -q 'execposter' &&
-printf '%s\n' "$TAIL_OUTPUT" | grep -q 'hello from exec'
-if [ $? -eq 0 ]; then
-    echo "✓ tail returns recent messages"
-    PASS=$((PASS + 1))
-else
-    echo "✗ tail output unexpected"
-    printf '%s\n' "$TAIL_OUTPUT"
-    FAIL=$((FAIL + 1))
-fi
-
-EXPECT_SCRIPT="${STATE_DIR}/watcher.expect"
-WATCHER_READY="${STATE_DIR}/watcher.ready"
-cat >"$EXPECT_SCRIPT" <<EOF
-set timeout 10
-spawn ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p $PORT watcher@localhost
-expect "请输入用户名"
-send "watcher\r"
-exec touch "$WATCHER_READY"
-sleep 8
-send "\003"
-expect eof
-EOF
-
-expect "$EXPECT_SCRIPT" >"${STATE_DIR}/expect.log" 2>&1 &
-INTERACTIVE_PID=$!
-
-for _ in 1 2 3 4 5 6 7 8 9 10; do
-    [ -f "$WATCHER_READY" ] && break
-    sleep 1
-done
-
-USERS_OUTPUT=""
-for _ in 1 2 3 4 5; do
-    USERS_OUTPUT=$(ssh $SSH_OPTS localhost users 2>/dev/null || true)
-    printf '%s\n' "$USERS_OUTPUT" | grep -q '^watcher$' && break
-    sleep 1
-done
-
-printf '%s\n' "$USERS_OUTPUT" | grep -q '^watcher$'
-if [ $? -eq 0 ]; then
-    echo "✓ users lists active interactive clients"
-    PASS=$((PASS + 1))
-else
-    echo "✗ users output unexpected"
-    printf '%s\n' "$USERS_OUTPUT"
-    [ -f "$WATCHER_READY" ] || echo "watcher readiness marker was not created"
-    [ -f "${STATE_DIR}/expect.log" ] && sed -n '1,120p' "${STATE_DIR}/expect.log"
-    sed -n '1,120p' "${STATE_DIR}/server.log"
-    FAIL=$((FAIL + 1))
-fi
-
-USERS_JSON=""
-for _ in 1 2 3 4 5; do
-    USERS_JSON=$(ssh $SSH_OPTS localhost users --json 2>/dev/null || true)
-    printf '%s\n' "$USERS_JSON" | grep -q '"watcher"' && break
-    sleep 1
-done
-
-printf '%s\n' "$USERS_JSON" | grep -q '"watcher"'
-if [ $? -eq 0 ]; then
-    echo "✓ users --json returns JSON array"
-    PASS=$((PASS + 1))
-else
-    echo "✗ users --json output unexpected"
-    printf '%s\n' "$USERS_JSON"
-    [ -f "$WATCHER_READY" ] || echo "watcher readiness marker was not created"
-    [ -f "${STATE_DIR}/expect.log" ] && sed -n '1,120p' "${STATE_DIR}/expect.log"
-    sed -n '1,120p' "${STATE_DIR}/server.log"
-    FAIL=$((FAIL + 1))
-fi
-
-wait "${INTERACTIVE_PID}" 2>/dev/null || true
-INTERACTIVE_PID=""
-
-echo ""
-echo "PASSED: $PASS"
-echo "FAILED: $FAIL"
-[ "$FAIL" -eq 0 ] && echo "All tests passed" || echo "Some tests failed"
-exit "$FAIL"

tests/test_security_features.sh

@@ -97,10 +97,6 @@ TNT_ACCESS_TOKEN="test123" $TIMEOUT_CMD 3 $BIN 2>&1 | grep -q "TNT chat server"
 TNT_MAX_CONNECTIONS=10 $TIMEOUT_CMD 3 $BIN 2>&1 | grep -q "TNT chat server" && \
     pass "TNT_MAX_CONNECTIONS configuration accepted" || fail "TNT_MAX_CONNECTIONS not working"
 
-# Test per-IP connection rate configuration
-TNT_MAX_CONN_RATE_PER_IP=20 $TIMEOUT_CMD 3 $BIN 2>&1 | grep -q "TNT chat server" && \
-    pass "TNT_MAX_CONN_RATE_PER_IP configuration accepted" || fail "TNT_MAX_CONN_RATE_PER_IP not working"
-
 # Test rate limit toggle
 TNT_RATE_LIMIT=0 $TIMEOUT_CMD 3 $BIN 2>&1 | grep -q "TNT chat server" && \
     pass "TNT_RATE_LIMIT configuration accepted" || fail "TNT_RATE_LIMIT not working"

tests/test_stress.sh

@@ -19,7 +19,7 @@ if command -v gtimeout >/dev/null 2>&1; then
 fi
 
 echo "Starting TNT server on port $PORT..."
-TNT_RATE_LIMIT=0 TNT_MAX_CONN_PER_IP=$CLIENTS $BIN -p $PORT &
+$BIN -p $PORT &
 SERVER_PID=$!
 sleep 2
 
@@ -47,7 +47,7 @@ kill $SERVER_PID 2>/dev/null
 wait
 
 echo "Stress test complete"
-if kill -0 $SERVER_PID 2>/dev/null; then
+if ps aux | grep tnt | grep -v grep > /dev/null; then
     echo "WARNING: tnt process still running"
 else
     echo "Server shutdown confirmed."

tnt.service

@@ -7,9 +7,8 @@ After=network.target
 Type=simple
 User=tnt
 Group=tnt
+WorkingDirectory=/var/lib/tnt
 ExecStart=/usr/local/bin/tnt
-StateDirectory=tnt
-StateDirectoryMode=0700
 
 # Automatic restart on failure for long-term stability
 Restart=always
@@ -40,8 +39,6 @@ TimeoutStopSec=30
 
 # Environment (can be customized via systemctl edit)
 Environment="PORT=2222"
-Environment="TNT_STATE_DIR=/var/lib/tnt"
-EnvironmentFile=-/etc/default/tnt
 
 [Install]
 WantedBy=multi-user.target