Merge pull request #33 from m1ngsama/feat/consolidated-features-manpage-deploy

Consolidated: bug fixes, features, manpage, deploy prep

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
@@ -71,10 +74,14 @@ check:
 	@command -v clang-tidy >/dev/null 2>&1 && clang-tidy src/*.c -- -Iinclude $(INCLUDES) || echo "clang-tidy not installed"
 
 # Test
-test: all
+test: all unit-test
-	@echo "Running tests..."
+	@echo "Running integration tests..."
 	@cd tests && ./test_basic.sh
 
+unit-test:
+	@echo "Running unit tests..."
+	@$(MAKE) -C tests/unit run
+
 # Show build info
 info:
 	@echo "Compiler: $(CC)"

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/message.c

@@ -1,7 +1,7 @@
 #ifndef _DEFAULT_SOURCE
 #define _DEFAULT_SOURCE  /* for timegm() on glibc */
 #endif
-#ifdef __APPLE__
+#if defined(__APPLE__) && !defined(_DARWIN_C_SOURCE)
 #define _DARWIN_C_SOURCE /* for timegm() on macOS */
 #endif
 #include "message.h"
@@ -61,7 +61,7 @@ int message_load(message_t **messages, int max_messages) {
     }
 
     long file_size = ftell(fp);
-    if (file_size == 0) {
+    if (file_size <= 0) {
         fclose(fp);
         *messages = msg_array;
         return 0;

src/ssh_server.c

@@ -108,16 +108,17 @@ static void buffer_append_bytes(char *buffer, size_t buf_size, size_t *pos,
     buffer[*pos] = '\0';
 }
 
-/* Constant-time string comparison to prevent timing side-channel attacks */
+/* Constant-time string comparison to prevent timing side-channel attacks.
+ * Always iterates over the full length of the secret (b) to avoid leaking
+ * its length.  When the input (a) is shorter, compares against zero bytes;
+ * the length mismatch is folded into the result separately. */
 static bool constant_time_strcmp(const char *a, const char *b) {
     size_t len_a = strlen(a);
     size_t len_b = strlen(b);
-    /* Use len_b (the secret) for iteration to avoid leaking its length
-     * through early termination.  The XOR of lengths catches mismatches. */
     volatile unsigned char result = (unsigned char)(len_a ^ len_b);
-    size_t len = (len_a < len_b) ? len_a : len_b;
+    for (size_t i = 0; i < len_b; i++) {
-    for (size_t i = 0; i < len; i++) {
+        unsigned char ca = (i < len_a) ? (unsigned char)a[i] : 0;
-        result |= (unsigned char)((unsigned char)a[i] ^ (unsigned char)b[i]);
+        result |= ca ^ (unsigned char)b[i];
     }
     return result == 0;
 }
@@ -194,8 +195,10 @@ static ip_rate_limit_t* get_rate_limit_entry(const char *ip) {
                 oldest_idx = i;
             }
         }
-        fprintf(stderr, "Warning: rate-limit table full, evicting active IP %s\n",
+        fprintf(stderr, "Warning: rate-limit table full, evicting active IP %s "
-                g_rate_limits[oldest_idx].ip);
+                "(%d active connections lost)\n",
+                g_rate_limits[oldest_idx].ip,
+                g_rate_limits[oldest_idx].active_connections);
     }
 
     /* Reset and reuse */
@@ -487,7 +490,9 @@ int client_send(client_t *client, const char *data, size_t len) {
     }
 
     while (total < len) {
-        int sent = ssh_channel_write(client->channel, data + total, len - total);
+        size_t remaining = len - total;
+        uint32_t chunk = (remaining > 32768) ? 32768 : (uint32_t)remaining;
+        int sent = ssh_channel_write(client->channel, data + total, chunk);
         if (sent <= 0) {
             pthread_mutex_unlock(&client->io_lock);
             return -1;
@@ -584,9 +589,18 @@ static int read_username(client_t *client) {
             break;
         } else if (b == 127 || b == 8) {  /* Backspace */
             if (pos > 0) {
+                /* Compute width of the last character before removing it */
+                int old_pos = pos;
+                int ci = pos - 1;
+                while (ci > 0 && (username[ci] & 0xC0) == 0x80) ci--;
+                int bytes_read;
+                uint32_t cp = utf8_decode(username + ci, &bytes_read);
+                int w = utf8_char_width(cp);
                 utf8_remove_last_char(username);
                 pos = strlen(username);
-                client_printf(client, "\b \b");
+                (void)old_pos;
+                for (int j = 0; j < w; j++)
+                    client_printf(client, "\b \b");
             }
         } else if (b < 32) {
             /* Ignore control characters */
@@ -1069,7 +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;
 
@@ -1084,6 +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,
@@ -1115,11 +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");
 
@@ -1239,62 +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 */
@@ -1339,6 +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') {
@@ -1367,6 +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);
@@ -1478,6 +1610,22 @@ void* client_handle_session(void *arg) {
                         client->command_input[len + 1] = '\0';
                         tui_render_screen(client);
                     }
+                } else if (b >= 128) {  /* UTF-8 multi-byte */
+                    int char_len = utf8_byte_length(b);
+                    if (char_len <= 0 || char_len > 4) continue;
+                    buf[0] = b;
+                    if (char_len > 1) {
+                        int read_bytes = ssh_channel_read_timeout(
+                            client->channel, &buf[1], char_len - 1, 0, 5000);
+                        if (read_bytes != char_len - 1) continue;
+                    }
+                    if (!utf8_is_valid_sequence(buf, char_len)) continue;
+                    size_t len = strlen(client->command_input);
+                    if (len + (size_t)char_len < sizeof(client->command_input) - 1) {
+                        memcpy(client->command_input + len, buf, char_len);
+                        client->command_input[len + char_len] = '\0';
+                        tui_render_screen(client);
+                    }
                 }
             }
         }
@@ -1496,6 +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);
@@ -1768,9 +1917,11 @@ static int client_channel_window_change(ssh_session session, ssh_channel channel
         return SSH_ERROR;
     }
 
-    client->width = width;
+    int w = width;
-    client->height = height;
+    int h = height;
-    sanitize_terminal_size(&client->width, &client->height);
+    sanitize_terminal_size(&w, &h);
+    client->width = w;
+    client->height = h;
     client->redraw_pending = true;
     return SSH_OK;
 }
@@ -1911,7 +2062,7 @@ static void *bootstrap_client_session(void *arg) {
             break;
         }
 
-        if (time(NULL) - start_time > 30) {
+        if (time(NULL) - start_time > 10) {
             timed_out = true;
         }
     }
@@ -1942,9 +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);
@@ -1969,10 +2122,12 @@ static void *bootstrap_client_session(void *arg) {
     client_addref(client);
 
     if (install_client_channel_callbacks(client) < 0) {
-        client_release(client);  /* drop the callback ref */
+        /* Nullify session/channel ownership so client_release won't
-        pthread_mutex_destroy(&client->io_lock);
+         * double-free what cleanup_failed_session is about to free. */
-        pthread_mutex_destroy(&client->ref_lock);
+        client->session = NULL;
-        free(client);
+        client->channel = NULL;
+        client_release(client);  /* drop the callback ref (2 → 1) */
+        client_release(client);  /* drop the main ref (1 → 0, frees client) */
         cleanup_failed_session(session, ctx);
         return NULL;
     }

src/tui.c

@@ -188,7 +188,7 @@ void tui_render_input(client_t *client, const char *input) {
     int input_width = utf8_string_width(input);
 
     /* Truncate from start if too long */
-    char display[1024];
+    char display[MAX_MESSAGE_LEN];
     strncpy(display, input, sizeof(display) - 1);
     display[sizeof(display) - 1] = '\0';
 
@@ -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/Makefile

@@ -1,13 +1,21 @@
 # Unit Tests Makefile
 CC = gcc
-CFLAGS = -Wall -Wextra -std=c11 -I../../include
+CFLAGS = -Wall -Wextra -std=c11 -D_XOPEN_SOURCE=700 -I../../include
 LDFLAGS = -pthread
 
+# Detect macOS for _DARWIN_C_SOURCE (needed for timegm)
+UNAME_S := $(shell uname -s)
+ifeq ($(UNAME_S),Darwin)
+CFLAGS += -D_DARWIN_C_SOURCE
+endif
+
 # Source files
 UTF8_SRC = ../../src/utf8.c
 MESSAGE_SRC = ../../src/message.c
+COMMON_SRC = ../../src/common.c
+CHAT_ROOM_SRC = ../../src/chat_room.c
 
-TESTS = test_utf8 test_message
+TESTS = test_utf8 test_message test_chat_room
 
 .PHONY: all clean run
 
@@ -16,7 +24,10 @@ all: $(TESTS)
 test_utf8: test_utf8.c $(UTF8_SRC)
 	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 
-test_message: test_message.c $(MESSAGE_SRC) $(UTF8_SRC)
+test_message: test_message.c $(MESSAGE_SRC) $(UTF8_SRC) $(COMMON_SRC)
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+test_chat_room: test_chat_room.c $(CHAT_ROOM_SRC) $(MESSAGE_SRC) $(UTF8_SRC) $(COMMON_SRC)
 	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 
 run: all
@@ -25,6 +36,9 @@ run: all
 	@echo ""
 	@echo "=== Running Message Tests ==="
 	./test_message
+	@echo ""
+	@echo "=== Running Chat Room Tests ==="
+	./test_chat_room
 
 clean:
 	rm -f $(TESTS) *.o test_messages.log

tests/unit/test_chat_room.c

@@ -0,0 +1,208 @@
+/* Unit tests for chat_room functions */
+
+/* Minimal client_t stub — only pointer identity matters for add/remove.
+ * We define `struct client` before including chat_room.h so the forward
+ * declaration resolves without pulling in ssh_server.h / libssh. */
+#include "../../include/common.h"
+
+struct client {
+    char username[MAX_USERNAME_LEN];
+    int dummy;
+};
+typedef struct client client_t;
+
+#include "../../include/chat_room.h"
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#define TEST(name) static void test_##name()
+#define RUN_TEST(name) do { \
+    printf("Running %s... ", #name); \
+    test_##name(); \
+    printf("✓\n"); \
+    tests_passed++; \
+} while(0)
+
+static int tests_passed = 0;
+
+static message_t make_msg(const char *user, const char *content) {
+    message_t m = { .timestamp = time(NULL) };
+    strncpy(m.username, user, MAX_USERNAME_LEN - 1);
+    strncpy(m.content, content, MAX_MESSAGE_LEN - 1);
+    return m;
+}
+
+TEST(room_create_destroy) {
+    chat_room_t *room = room_create();
+    assert(room != NULL);
+    assert(room->client_count == 0);
+    assert(room->client_capacity > 0);
+    room_destroy(room);
+}
+
+TEST(room_add_message_single) {
+    chat_room_t *room = room_create();
+    message_t msg = make_msg("alice", "hello");
+
+    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);
+
+    room_destroy(room);
+}
+
+TEST(room_add_message_overflow) {
+    chat_room_t *room = room_create();
+
+    for (int i = 0; i < MAX_MESSAGES + 10; i++) {
+        char content[32];
+        snprintf(content, sizeof(content), "msg %d", i);
+        message_t msg = make_msg("user", content);
+        room_broadcast(room, &msg);
+    }
+
+    assert(room->message_count == MAX_MESSAGES);
+
+    char expected[32];
+    snprintf(expected, sizeof(expected), "msg %d", 10);
+    assert(strcmp(room->messages[0].content, expected) == 0);
+
+    snprintf(expected, sizeof(expected), "msg %d", MAX_MESSAGES + 9);
+    assert(strcmp(room->messages[MAX_MESSAGES - 1].content, expected) == 0);
+
+    room_destroy(room);
+}
+
+TEST(room_broadcast_increments_seq) {
+    chat_room_t *room = room_create();
+    g_room = room;
+
+    uint64_t seq1 = room_get_update_seq(room);
+    message_t msg = make_msg("bob", "hi");
+    room_broadcast(room, &msg);
+    uint64_t seq2 = room_get_update_seq(room);
+
+    assert(seq2 > seq1);
+    assert(room_get_message_count(room) == 1);
+
+    g_room = NULL;
+    room_destroy(room);
+}
+
+TEST(room_get_message_valid) {
+    chat_room_t *room = room_create();
+    message_t msg = make_msg("carol", "test");
+    room_broadcast(room, &msg);
+
+    message_t out;
+    assert(room_get_message(room, 0, &out) == true);
+    assert(strcmp(out.username, "carol") == 0);
+    assert(strcmp(out.content, "test") == 0);
+
+    room_destroy(room);
+}
+
+TEST(room_get_message_invalid_index) {
+    chat_room_t *room = room_create();
+
+    message_t out;
+    assert(room_get_message(room, 0, &out) == false);
+    assert(room_get_message(room, -1, &out) == false);
+    assert(room_get_message(room, 999, &out) == false);
+
+    room_destroy(room);
+}
+
+TEST(room_get_message_null_args) {
+    chat_room_t *room = room_create();
+    message_t out;
+
+    assert(room_get_message(NULL, 0, &out) == false);
+    assert(room_get_message(room, 0, NULL) == false);
+
+    room_destroy(room);
+}
+
+TEST(room_client_count) {
+    chat_room_t *room = room_create();
+    assert(room_get_client_count(room) == 0);
+
+    client_t c1 = {0};
+    client_t c2 = {0};
+    assert(room_add_client(room, &c1) == 0);
+    assert(room_get_client_count(room) == 1);
+    assert(room_add_client(room, &c2) == 0);
+    assert(room_get_client_count(room) == 2);
+
+    room_remove_client(room, &c1);
+    assert(room_get_client_count(room) == 1);
+
+    room_remove_client(room, &c2);
+    assert(room_get_client_count(room) == 0);
+
+    room_destroy(room);
+}
+
+TEST(room_remove_nonexistent_client) {
+    chat_room_t *room = room_create();
+    client_t c1 = {0};
+    client_t c2 = {0};
+
+    room_add_client(room, &c1);
+    room_remove_client(room, &c2);
+    assert(room_get_client_count(room) == 1);
+
+    room_destroy(room);
+}
+
+TEST(room_add_client_full) {
+    chat_room_t *room = room_create();
+    client_t clients[MAX_CLIENTS + 1];
+    memset(clients, 0, sizeof(clients));
+
+    for (int i = 0; i < room->client_capacity; i++) {
+        assert(room_add_client(room, &clients[i]) == 0);
+    }
+
+    assert(room_add_client(room, &clients[room->client_capacity]) == -1);
+    assert(room_get_client_count(room) == room->client_capacity);
+
+    room_destroy(room);
+}
+
+TEST(room_message_count_threadsafe) {
+    chat_room_t *room = room_create();
+
+    assert(room_get_message_count(room) == 0);
+
+    message_t msg = make_msg("dave", "msg");
+    room_broadcast(room, &msg);
+    assert(room_get_message_count(room) == 1);
+
+    room_broadcast(room, &msg);
+    room_broadcast(room, &msg);
+    assert(room_get_message_count(room) == 3);
+
+    room_destroy(room);
+}
+
+int main(void) {
+    printf("=== Chat Room Unit Tests ===\n");
+
+    RUN_TEST(room_create_destroy);
+    RUN_TEST(room_add_message_single);
+    RUN_TEST(room_add_message_overflow);
+    RUN_TEST(room_broadcast_increments_seq);
+    RUN_TEST(room_get_message_valid);
+    RUN_TEST(room_get_message_invalid_index);
+    RUN_TEST(room_get_message_null_args);
+    RUN_TEST(room_client_count);
+    RUN_TEST(room_remove_nonexistent_client);
+    RUN_TEST(room_add_client_full);
+    RUN_TEST(room_message_count_threadsafe);
+
+    printf("\nAll %d tests passed!\n", tests_passed);
+    return 0;
+}

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)