feat: consolidated improvements, manpage, and deployment prep

Bug fixes:
- Fix data race on client->width/height (now _Atomic int)
- Persist join/leave system messages via message_save()
- Make room_add_message static to enforce lock contract
- Fix execute_command mutating command_input directly
- Increase help_copy buffer from 4096 to 8192 for CJK safety

New features:
- Add :msg/:w whisper command for private messaging
- Add command history with UP/DOWN arrows in command mode
- Add Ctrl+D/U/F/B page scrolling in normal mode
- Add :q/:quit/:exit Vim-style disconnect

Unix community:
- Add tnt.1 manpage (roff format) with full documentation
- Add manpage install/uninstall to Makefile

Makefile

@@ -45,9 +45,12 @@ clean:
 install: $(TARGET)
 	install -d $(DESTDIR)/usr/local/bin
 	install -m 755 $(TARGET) $(DESTDIR)/usr/local/bin/
+	install -d $(DESTDIR)/usr/local/share/man/man1
+	install -m 644 tnt.1 $(DESTDIR)/usr/local/share/man/man1/
 
 uninstall:
 	rm -f $(DESTDIR)/usr/local/bin/$(TARGET)
+	rm -f $(DESTDIR)/usr/local/share/man/man1/tnt.1
 
 # Development targets
 debug: CFLAGS += -g -DDEBUG

include/chat_room.h

@@ -36,9 +36,6 @@ void room_remove_client(chat_room_t *room, struct client *client);
 /* Broadcast message to all clients */
 void room_broadcast(chat_room_t *room, const message_t *msg);
 
-/* Add message to room history */
-void room_add_message(chat_room_t *room, const message_t *msg);
-
 /* Get message by index (thread-safe value copy) */
 bool room_get_message(chat_room_t *room, int index, message_t *out);
 

include/ssh_server.h

@@ -13,14 +13,17 @@ typedef struct client {
     ssh_channel channel;             /* SSH channel */
     char username[MAX_USERNAME_LEN];
     char client_ip[INET6_ADDRSTRLEN];
-    int width;
+    _Atomic int width;
-    int height;
+    _Atomic int height;
     client_mode_t mode;
     help_lang_t help_lang;
     int scroll_pos;
     int help_scroll_pos;
     bool show_help;
     char command_input[256];
+    char command_history[16][256];
+    int command_history_count;
+    int command_history_pos;
     char command_output[2048];
     char exec_command[MAX_EXEC_COMMAND_LEN];
     char ssh_login[MAX_USERNAME_LEN];

src/chat_room.c

@@ -87,23 +87,9 @@ void room_remove_client(chat_room_t *room, struct client *client) {
     pthread_rwlock_unlock(&room->lock);
 }
 
-/* Broadcast message to all clients */
+/* Add message to room history (caller must hold write lock) */
-void room_broadcast(chat_room_t *room, const message_t *msg) {
+static void room_add_message(chat_room_t *room, const message_t *msg) {
-    pthread_rwlock_wrlock(&room->lock);
-
-    /* Add to history */
-    room_add_message(room, msg);
-    room->update_seq++;
-
-    pthread_rwlock_unlock(&room->lock);
-}
-
-/* Add message to room history */
-void room_add_message(chat_room_t *room, const message_t *msg) {
-    /* Caller should hold write lock */
-
     if (room->message_count >= MAX_MESSAGES) {
-        /* Shift messages to make room */
         memmove(&room->messages[0], &room->messages[1],
                 (MAX_MESSAGES - 1) * sizeof(message_t));
         room->message_count = MAX_MESSAGES - 1;
@@ -112,6 +98,16 @@ void room_add_message(chat_room_t *room, const message_t *msg) {
     room->messages[room->message_count++] = *msg;
 }
 
+/* Broadcast message to all clients */
+void room_broadcast(chat_room_t *room, const message_t *msg) {
+    pthread_rwlock_wrlock(&room->lock);
+
+    room_add_message(room, msg);
+    room->update_seq++;
+
+    pthread_rwlock_unlock(&room->lock);
+}
+
 /* Get message by index (thread-safe value copy) */
 bool room_get_message(chat_room_t *room, int index, message_t *out) {
     if (!room || !out) return false;

src/ssh_server.c

@@ -1083,7 +1083,10 @@ static int execute_exec_command(client_t *client) {
 
 /* Execute a command */
 static void execute_command(client_t *client) {
-    char *cmd = client->command_input;
+    char cmd_buf[256];
+    strncpy(cmd_buf, client->command_input, sizeof(cmd_buf) - 1);
+    cmd_buf[sizeof(cmd_buf) - 1] = '\0';
+    char *cmd = cmd_buf;
     char output[2048] = {0};
     size_t pos = 0;
 
@@ -1098,6 +1101,21 @@ static void execute_command(client_t *client) {
         }
     }
 
+    /* Save to command history */
+    if (cmd[0] != '\0') {
+        int max_hist = 16;
+        if (client->command_history_count >= max_hist) {
+            memmove(&client->command_history[0], &client->command_history[1],
+                    (max_hist - 1) * sizeof(client->command_history[0]));
+            client->command_history_count = max_hist - 1;
+        }
+        strncpy(client->command_history[client->command_history_count],
+                cmd, sizeof(client->command_history[0]) - 1);
+        client->command_history[client->command_history_count][sizeof(client->command_history[0]) - 1] = '\0';
+        client->command_history_count++;
+        client->command_history_pos = client->command_history_count;
+    }
+
     if (strcmp(cmd, "list") == 0 || strcmp(cmd, "users") == 0 ||
         strcmp(cmd, "who") == 0) {
         buffer_appendf(output, sizeof(output), &pos,
@@ -1129,11 +1147,59 @@ static void execute_command(client_t *client) {
                        "========================================\n"
                        "        Available Commands\n"
                        "========================================\n"
-                       "list, users, who - Show online users\n"
+                       "list, users, who    - Show online users\n"
-                       "help, commands   - Show this help\n"
+                       "msg/w <user> <text> - Whisper to user\n"
-                       "clear, cls       - Clear command output\n"
+                       "help, commands      - Show this help\n"
+                       "clear, cls          - Clear command output\n"
+                       "q, quit, exit       - Disconnect\n"
+                       "Up/Down arrows      - Command history\n"
                        "========================================\n");
 
+    } else if (strncmp(cmd, "msg ", 4) == 0 || strncmp(cmd, "w ", 2) == 0) {
+        char *rest = (cmd[0] == 'w') ? cmd + 2 : cmd + 4;
+        while (*rest == ' ') rest++;
+        char target_name[MAX_USERNAME_LEN] = {0};
+        int ti = 0;
+        while (*rest && *rest != ' ' && ti < MAX_USERNAME_LEN - 1) {
+            target_name[ti++] = *rest++;
+        }
+        while (*rest == ' ') rest++;
+
+        if (target_name[0] == '\0' || rest[0] == '\0') {
+            buffer_appendf(output, sizeof(output), &pos,
+                           "Usage: msg <username> <message>\n"
+                           "       w <username> <message>\n");
+        } else {
+            bool found = false;
+            pthread_rwlock_rdlock(&g_room->lock);
+            for (int i = 0; i < g_room->client_count; i++) {
+                if (strcmp(g_room->clients[i]->username, target_name) == 0) {
+                    char whisper[MAX_MESSAGE_LEN];
+                    snprintf(whisper, sizeof(whisper),
+                             "\r\n\033[35m[whisper from %s]: %s\033[0m\r\n",
+                             client->username, rest);
+                    client_send(g_room->clients[i], whisper, strlen(whisper));
+                    g_room->clients[i]->redraw_pending = true;
+                    found = true;
+                    break;
+                }
+            }
+            pthread_rwlock_unlock(&g_room->lock);
+
+            if (found) {
+                buffer_appendf(output, sizeof(output), &pos,
+                               "Whisper sent to %s\n", target_name);
+            } else {
+                buffer_appendf(output, sizeof(output), &pos,
+                               "User '%s' not found\n", target_name);
+            }
+        }
+
+    } else if (strcmp(cmd, "q") == 0 || strcmp(cmd, "quit") == 0 ||
+               strcmp(cmd, "exit") == 0) {
+        client->connected = false;
+        return;
+
     } else if (strcmp(cmd, "clear") == 0 || strcmp(cmd, "cls") == 0) {
         buffer_appendf(output, sizeof(output), &pos, "Command output cleared\n");
 
@@ -1253,62 +1319,111 @@ static bool handle_key(client_t *client, unsigned char key, char *input) {
             }
             break;
 
-        case MODE_NORMAL:
+        case MODE_NORMAL: {
+            int nm_msg_count = room_get_message_count(g_room);
+            int nm_msg_height = client->height - 3;
+            if (nm_msg_height < 1) nm_msg_height = 1;
+            int nm_max_scroll = nm_msg_count - nm_msg_height;
+            if (nm_max_scroll < 0) nm_max_scroll = 0;
+
             if (key == 'i') {
                 client->mode = MODE_INSERT;
                 tui_render_screen(client);
-                return true;  /* Key consumed */
+                return true;
             } else if (key == ':') {
                 client->mode = MODE_COMMAND;
                 client->command_input[0] = '\0';
                 tui_render_screen(client);
-                return true;  /* Key consumed - prevents double colon */
+                return true;
             } else if (key == 'j') {
-                /* Get message count atomically to prevent TOCTOU */
+                if (client->scroll_pos < nm_max_scroll) {
-                int max_scroll = room_get_message_count(g_room);
-                int msg_height = client->height - 3;
-                if (msg_height < 1) msg_height = 1;
-                max_scroll = max_scroll - msg_height;
-                if (max_scroll < 0) max_scroll = 0;
-
-                if (client->scroll_pos < max_scroll) {
                     client->scroll_pos++;
                     tui_render_screen(client);
                 }
-                return true;  /* Key consumed */
+                return true;
             } else if (key == 'k' && client->scroll_pos > 0) {
                 client->scroll_pos--;
                 tui_render_screen(client);
-                return true;  /* Key consumed */
+                return true;
+            } else if (key == 4) {  /* Ctrl+D: half page down */
+                int half = nm_msg_height / 2;
+                if (half < 1) half = 1;
+                client->scroll_pos += half;
+                if (client->scroll_pos > nm_max_scroll) client->scroll_pos = nm_max_scroll;
+                tui_render_screen(client);
+                return true;
+            } else if (key == 21) {  /* Ctrl+U: half page up */
+                int half = nm_msg_height / 2;
+                if (half < 1) half = 1;
+                client->scroll_pos -= half;
+                if (client->scroll_pos < 0) client->scroll_pos = 0;
+                tui_render_screen(client);
+                return true;
+            } else if (key == 6) {  /* Ctrl+F: full page down */
+                client->scroll_pos += nm_msg_height;
+                if (client->scroll_pos > nm_max_scroll) client->scroll_pos = nm_max_scroll;
+                tui_render_screen(client);
+                return true;
+            } else if (key == 2) {  /* Ctrl+B: full page up */
+                client->scroll_pos -= nm_msg_height;
+                if (client->scroll_pos < 0) client->scroll_pos = 0;
+                tui_render_screen(client);
+                return true;
             } else if (key == 'g') {
                 client->scroll_pos = 0;
                 tui_render_screen(client);
-                return true;  /* Key consumed */
+                return true;
             } else if (key == 'G') {
-                /* Get message count atomically to prevent TOCTOU */
+                client->scroll_pos = nm_max_scroll;
-                int max_scroll = room_get_message_count(g_room);
-                int msg_height = client->height - 3;
-                if (msg_height < 1) msg_height = 1;
-                max_scroll = max_scroll - msg_height;
-                if (max_scroll < 0) max_scroll = 0;
-
-                client->scroll_pos = max_scroll;
                 tui_render_screen(client);
-                return true;  /* Key consumed */
+                return true;
             } else if (key == '?') {
                 client->show_help = true;
                 client->help_scroll_pos = 0;
                 tui_render_help(client);
-                return true;  /* Key consumed */
+                return true;
             }
             break;
+        }
 
         case MODE_COMMAND:
-            if (key == 27) {  /* ESC */
+            if (key == 27) {  /* ESC - check for arrow key sequences */
+                char seq[2];
+                int n = ssh_channel_read_timeout(client->channel, seq, 1, 0, 50);
+                if (n == 1 && seq[0] == '[') {
+                    n = ssh_channel_read_timeout(client->channel, &seq[1], 1, 0, 50);
+                    if (n == 1) {
+                        if (seq[1] == 'A') {  /* Up arrow */
+                            if (client->command_history_count > 0 &&
+                                client->command_history_pos > 0) {
+                                client->command_history_pos--;
+                                strncpy(client->command_input,
+                                        client->command_history[client->command_history_pos],
+                                        sizeof(client->command_input) - 1);
+                                client->command_input[sizeof(client->command_input) - 1] = '\0';
+                                tui_render_screen(client);
+                            }
+                            return true;
+                        } else if (seq[1] == 'B') {  /* Down arrow */
+                            if (client->command_history_pos < client->command_history_count - 1) {
+                                client->command_history_pos++;
+                                strncpy(client->command_input,
+                                        client->command_history[client->command_history_pos],
+                                        sizeof(client->command_input) - 1);
+                                client->command_input[sizeof(client->command_input) - 1] = '\0';
+                            } else {
+                                client->command_history_pos = client->command_history_count;
+                                client->command_input[0] = '\0';
+                            }
+                            tui_render_screen(client);
+                            return true;
+                        }
+                    }
+                }
                 client->mode = MODE_NORMAL;
                 client->command_input[0] = '\0';
                 tui_render_screen(client);
-                return true;  /* Key consumed */
+                return true;
             } else if (key == '\r' || key == '\n') {
                 execute_command(client);
                 return true;  /* Key consumed */
@@ -1353,6 +1468,8 @@ void* client_handle_session(void *arg) {
     client->mode = MODE_INSERT;
     client->help_lang = LANG_ZH;
     client->connected = true;
+    client->command_history_count = 0;
+    client->command_history_pos = 0;
 
     /* Check for exec command */
     if (client->exec_command[0] != '\0') {
@@ -1381,6 +1498,7 @@ void* client_handle_session(void *arg) {
     join_msg.username[MAX_USERNAME_LEN - 1] = '\0';
     snprintf(join_msg.content, MAX_MESSAGE_LEN, "%s 加入了聊天室", client->username);
     room_broadcast(g_room, &join_msg);
+    message_save(&join_msg);
 
     /* Render initial screen */
     tui_render_screen(client);
@@ -1526,6 +1644,7 @@ cleanup:
         client->connected = false;
         room_remove_client(g_room, client);
         room_broadcast(g_room, &leave_msg);
+        message_save(&leave_msg);
     }
 
     release_ip_connection(client->client_ip);
@@ -1798,11 +1917,11 @@ static int client_channel_window_change(ssh_session session, ssh_channel channel
         return SSH_ERROR;
     }
 
-    pthread_mutex_lock(&client->io_lock);
+    int w = width;
-    client->width = width;
+    int h = height;
-    client->height = height;
+    sanitize_terminal_size(&w, &h);
-    sanitize_terminal_size(&client->width, &client->height);
+    client->width = w;
-    pthread_mutex_unlock(&client->io_lock);
+    client->height = h;
     client->redraw_pending = true;
     return SSH_OK;
 }
@@ -1974,9 +2093,11 @@ static void *bootstrap_client_session(void *arg) {
 
     client->session = session;
     client->channel = channel;
-    client->width = ctx->pty_width;
+    int init_w = ctx->pty_width;
-    client->height = ctx->pty_height;
+    int init_h = ctx->pty_height;
-    sanitize_terminal_size(&client->width, &client->height);
+    sanitize_terminal_size(&init_w, &init_h);
+    client->width = init_w;
+    client->height = init_h;
     client->ref_count = 1;
     pthread_mutex_init(&client->ref_lock, NULL);
     pthread_mutex_init(&client->io_lock, NULL);

src/tui.c

@@ -386,7 +386,7 @@ void tui_render_help(client_t *client) {
 
     /* Help content */
     const char *help_text = tui_get_help_text(client->help_lang);
-    char help_copy[4096];
+    char help_copy[8192];
     strncpy(help_copy, help_text, sizeof(help_copy) - 1);
     help_copy[sizeof(help_copy) - 1] = '\0';
 

tests/unit/test_chat_room.c

@@ -45,7 +45,7 @@ TEST(room_add_message_single) {
     chat_room_t *room = room_create();
     message_t msg = make_msg("alice", "hello");
 
-    room_add_message(room, &msg);
+    room_broadcast(room, &msg);
     assert(room->message_count == 1);
     assert(strcmp(room->messages[0].username, "alice") == 0);
     assert(strcmp(room->messages[0].content, "hello") == 0);
@@ -60,7 +60,7 @@ TEST(room_add_message_overflow) {
         char content[32];
         snprintf(content, sizeof(content), "msg %d", i);
         message_t msg = make_msg("user", content);
-        room_add_message(room, &msg);
+        room_broadcast(room, &msg);
     }
 
     assert(room->message_count == MAX_MESSAGES);
@@ -94,7 +94,7 @@ TEST(room_broadcast_increments_seq) {
 TEST(room_get_message_valid) {
     chat_room_t *room = room_create();
     message_t msg = make_msg("carol", "test");
-    room_add_message(room, &msg);
+    room_broadcast(room, &msg);
 
     message_t out;
     assert(room_get_message(room, 0, &out) == true);

tnt.1

@@ -0,0 +1,210 @@
+.\" tnt(1) - Terminal Network Talk
+.TH TNT 1 "April 2026" "TNT 1.0.0" "User Commands"
+.SH NAME
+tnt \- anonymous SSH chat server with Vim\-style TUI
+.SH SYNOPSIS
+.B tnt
+.RB [ \-p
+.IR port ]
+.RB [ \-d
+.IR dir ]
+.RB [ \-h ]
+.SH DESCRIPTION
+.B tnt
+is a multi\-user anonymous chat server accessed over SSH.
+It provides a Vim\-style terminal user interface with INSERT, NORMAL, and
+COMMAND modes.
+Users connect with any standard SSH client; no account or registration is needed.
+.PP
+Messages are persisted to a log file and restored on server restart.
+The server supports CJK and emoji input, rate limiting, access tokens, and
+a non\-interactive exec interface for scripting.
+.SH OPTIONS
+.TP
+.BI \-p " port"
+Listen on
+.I port
+instead of the default 2222.
+Overrides the
+.B PORT
+environment variable.
+.TP
+.BI \-d " dir"
+Store the host key and message log in
+.IR dir .
+Overrides the
+.B TNT_STATE_DIR
+environment variable.
+Defaults to the current working directory.
+.TP
+.B \-h
+Print a short usage summary and exit.
+.SH CONNECTING
+.PP
+.nf
+ssh any\-username@hostname \-p 2222
+.fi
+.PP
+If an access token is configured, supply it as the SSH password.
+The username entered in the SSH handshake is ignored; a chat\-room
+nickname is chosen interactively after login.
+.SH MODES
+.TP
+.B INSERT
+Type and send messages.
+Press
+.B Enter
+to send,
+.B ESC
+to switch to NORMAL mode.
+.TP
+.B NORMAL
+Scroll through chat history with Vim keybindings.
+Press
+.B i
+to return to INSERT,
+.B :
+to enter COMMAND mode,
+.B ?
+to open the help screen.
+.TP
+.B COMMAND
+Execute commands prefixed with
+.BR : .
+.SH KEYBINDINGS
+.SS INSERT mode
+.TS
+l l.
+Enter	Send message
+ESC	Switch to NORMAL
+Ctrl+W	Delete last word
+Ctrl+U	Clear input line
+Ctrl+C	Switch to NORMAL
+.TE
+.SS NORMAL mode
+.TS
+l l.
+j/k	Scroll down/up one line
+Ctrl+D/Ctrl+U	Scroll half page down/up
+Ctrl+F/Ctrl+B	Scroll full page down/up
+g/G	Jump to top/bottom
+i	Switch to INSERT
+:	Enter COMMAND mode
+?	Open help screen
+Ctrl+C	Disconnect
+.TE
+.SS COMMAND mode
+.TS
+l l.
+:list	Show online users
+:msg \fIuser text\fR	Send private whisper
+:w \fIuser text\fR	Short alias for :msg
+:help	Show available commands
+:clear	Clear command output
+:q, :quit, :exit	Disconnect
+Up/Down	Browse command history
+ESC	Cancel and return to NORMAL
+.TE
+.SH EXEC INTERFACE
+Commands can be run non\-interactively for scripting:
+.PP
+.nf
+ssh host \-p 2222 help
+ssh host \-p 2222 users \-\-json
+ssh host \-p 2222 stats \-\-json
+ssh host \-p 2222 tail 20
+ssh host \-p 2222 post "Hello from a script"
+ssh host \-p 2222 health
+.fi
+.PP
+Exit codes follow
+.BR sysexits (3)
+conventions.
+.SH ENVIRONMENT
+.TP
+.B PORT
+Default listening port (default: 2222).
+.TP
+.B TNT_STATE_DIR
+Directory for host key and message log (default: current directory).
+.TP
+.B TNT_ACCESS_TOKEN
+If set, clients must supply this string as their SSH password.
+Compared in constant time.
+.TP
+.B TNT_MAX_CONNECTIONS
+Global connection limit (default: 64, max: 1024).
+.TP
+.B TNT_MAX_CONN_PER_IP
+Max concurrent sessions from one IP (default: 5).
+.TP
+.B TNT_MAX_CONN_RATE_PER_IP
+Max new connections per IP per 60\-second window (default: 10).
+.TP
+.B TNT_RATE_LIMIT
+Set to 0 to disable rate\-based blocking and auth\-failure IP blocking.
+Explicit capacity limits still apply (default: 1).
+.SH FILES
+.TP
+.I messages.log
+Chat history in RFC\ 3339 pipe\-delimited format
+.RI ( timestamp | username | content ).
+Stored in the state directory.
+.TP
+.I host_key
+RSA 4096\-bit host key, auto\-generated on first run.
+Stored in the state directory with mode 0600.
+.SH SYSTEMD
+A unit file
+.I tnt.service
+is provided.
+Typical setup:
+.PP
+.nf
+sudo useradd \-r \-s /bin/false tnt
+sudo cp tnt.service /etc/systemd/system/
+sudo systemctl daemon\-reload
+sudo systemctl enable \-\-now tnt
+.fi
+.PP
+Runtime overrides can be placed in
+.IR /etc/default/tnt .
+.SH SECURITY
+.IP \(bu 2
+Reference\-counted client lifecycle prevents use\-after\-free.
+.IP \(bu 2
+Per\-IP rate limiting with auth\-failure blocking (5 failures = 5\-minute ban).
+.IP \(bu 2
+Access\-token comparison uses constant\-time algorithm.
+.IP \(bu 2
+Host key created with restrictive permissions (0600).
+.IP \(bu 2
+systemd hardening: NoNewPrivileges, PrivateTmp, ProtectSystem=strict.
+.SH EXAMPLES
+Start on port 3000 with state in /var/lib/tnt:
+.PP
+.nf
+tnt \-p 3000 \-d /var/lib/tnt
+.fi
+.PP
+Start with an access token:
+.PP
+.nf
+TNT_ACCESS_TOKEN=s3cret tnt
+.fi
+.PP
+Connect from another machine:
+.PP
+.nf
+ssh user@chat.example.com \-p 2222
+.fi
+.SH AUTHORS
+m1ngsama <contact@m1ng.space>
+.SH BUGS
+Report bugs at
+.UR https://github.com/m1ngsama/TNT/issues
+.UE .
+.SH SEE ALSO
+.BR ssh (1),
+.BR sshd (8),
+.BR systemctl (1)