STM32F4-Base/test/host/lftpd/lftpd_test.c

/*
 * 模块名称：FTP 控制通道协议层（lftpd）主机侧单元测试
 * 模块功能：在 PC 上离线验证 Drivers/BSP/NET/lftpd/lftpd.c 的控制通道状态机与 17 条
 *           命令处理器：认证前置白名单、超长命令名拒绝（不越界写命令缓冲）、未知命令
 *           502、QUIT 收尾时释放数据监听、大小写不敏感、PASV/EPSV 的 227/229 响应
 *           编码、数据 accept 失败时不残留半开监听、STOR 失败要**删掉半成品**、
 *           写开关关闭时 DELE/STOR 一律 550、CWD 的目录判定与截断安全、FEAT 多行
 *           响应的首尾行格式。
 *
 * 被测对象：真实源文件 ../../../../Drivers/BSP/NET/lftpd/lftpd.c（#include 纳入，
 *           因此命令表 commands[]、24 个 static cmd_* 与 handle_control_channel 都
 *           可在同一 TU 内直接驱动）。假的是它下面三层：inet 适配（脚本化命令行
 *           队列 + 响应记录）、io 层（极简内存视图：stat/open/read/write/opendir/
 *           readdir/unlink + 可注入失败）、认证与配置（ftp_auth_check/ftp_cfg_get
 *           可注入结果，认证本身有 test/host/ftp_auth 的 10 条专测，不重复）。
 *
 * 为什么要主机侧单测（而不是只靠台架）：
 *   1. **半成品文件**是 FTP 最贵的坑：STOR 传到一半对端断了，如果不 unlink，Flash 上
 *      就永久留一个残缺文件（现场表现为"升级包传坏了再也传不上去"）。真机上要卡准
 *      "传一半掐线"的时机，主机侧把 io 层的写失败注进去就行。
 *   2. 数据通道是**单连接 socket**：LIST/RETR/STOR 每条命令用完必须把监听关掉并复位
 *      data_socket=-1，否则下一条命令拿着上一个号继续 accept，表现是偶发连不上且
 *      与上一会话时序相关。这类"忘了复位"只有把 accept 失败也注进来才测得干净。
 *   3. 命令名缓冲是 command_tmp[4+1]，而判断用 if (index >= 5) 先拦——这条边界
 *      （恰好 5 个字符的命令名必须被拒）就是防 memcpy 越界，改一行就没了。
 *   4. 写开关（[ftp] write_en=0）是现场防误删的闸门，DELE/STOR 必须在**碰文件之前**
 *      就拒绝，且此时不该去 accept 数据通道。
 *
 * 覆盖点：TC-LFTPD-001 认证白名单；002 超长命令名；003 未知命令 502；004 QUIT 退出；
 *   005 欢迎未送达就收工；006 退出时释放数据监听；007 大小写不敏感；008 无参数命令；
 *   010 未开被动模式的数据命令 425；011/012/013 PASV/EPSV 响应；014 数据 accept 失败
 *   不留残口；015/016 LIST 成功与目录打不开；017/018 RETR 成功与打不开；
 *   019/020 STOR 删半成品与写开关；021 DELE 写开关；022/023 CWD；024 SIZE；025 PWD；
 *   026 SYST；027 FEAT 多行；028/029 口令失败与锁定；030 TYPE/NOOP。
 *
 * 通过：全部 TC PASS（main 返回 0）。
 * 入口：int main(void)，返回 0=PASS / 1=FAIL（由 run 脚本判读）。
 *
 * 创建日期：2026-10-23
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lftpd.h"
#include "lftpd_auth.h"
#include "ftp_cfg.h"
#include "ff.h"

#include "lftpd.c"
/* 命令行 trim 用**真实实现**（16 行、零依赖；lftpd_string.c 的契约由
   test/host/lftpd_io 的 TC-LFTSTR-* 专测，这里只是满足链接、顺带让参数解析走真码）。 */
#include "lftpd_string.c"

static int s_total;
static int s_passed;
static int s_failed;

#define CHECK(cond, name) do { \
    s_total++; \
    if (cond) { s_passed++; printf("  PASS %s\n", name); } \
    else { s_failed++; printf("  FAIL %s (line %d)\n", name, __LINE__); } \
} while (0)

/* ===================== 桩：日志计数 =====================
 * lftpd_log_info/error/peer/debug 是真实 private/lftpd_log.h 里的**宏**，展开成
 * DBG_*；本模块只桩最底下的 dbg_log.h（计数）。这样真实分级逻辑一起被编译验证：
 * peer 级归 INFO、debug 级在 MCU 上被整条摘掉。 */

int g_lg_info_count;
int g_lg_error_count;
int g_lg_debug_count;

/* ===================== 桩：假堆（返回给 vPortFree 的路径缓冲） ===================== */

static uint8_t g_pool[2048];
static size_t  g_pool_used;
static int     g_free_calls;

void *pvPortMalloc(size_t xWantedSize)
{
    void *p;

    g_pool_used = (g_pool_used + 7u) & ~(size_t)7u;
    if ((g_pool_used + xWantedSize) > sizeof(g_pool)) {
        return NULL;
    }
    p = &g_pool[g_pool_used];
    g_pool_used += xWantedSize;
    return p;
}

void vPortFree(void *pv)
{
    if (pv != NULL) {
        g_free_calls++;
    }
}

/* ===================== 假 inet 层：脚本化命令行 + 响应记录 ===================== */

typedef struct {
    const char *lines[16];
    int         line_ret[16];
    int         line_n;
    int         line_i;
    char        replies[32][256];
    int         reply_n;
    int         string_rc;       /* write_string 返回（0=成功） */
    int         listen_rc;
    int         port;
    int         accept_to_rc;    /* 数据通道 accept 结果 */
    int         data_write_rc;   /* 数据写返回（<0 模拟对端断） */
    int         rx_left;         /* 数据通道还剩多少字节可读 */
    int         close_calls;
    int         listen_calls;
    int         accept_calls;
    int         delay_calls;
} lftp_net_t;

static lftp_net_t g_n;

int lftpd_inet_read_line(int socket, char *buffer, size_t buffer_len)
{
    (void)socket;
    if (g_n.line_i >= g_n.line_n) {
        return -1;                    /* 脚本喂完 = 对端关闭 */
    }
    (void)strncpy(buffer, g_n.lines[g_n.line_i], buffer_len - 1u);
    buffer[buffer_len - 1u] = '\0';
    return g_n.line_ret[g_n.line_i++];
}

int lftpd_inet_write_string(int socket, const char *message)
{
    (void)socket;
    if (g_n.reply_n < (int)(sizeof(g_n.replies) / sizeof(g_n.replies[0]))) {
        (void)strncpy(g_n.replies[g_n.reply_n], message, sizeof(g_n.replies[0]) - 1u);
        g_n.replies[g_n.reply_n][sizeof(g_n.replies[0]) - 1u] = '\0';
        g_n.reply_n++;
    }
    return g_n.string_rc;
}

int lftpd_inet_write(int socket, const void *buf, int len)
{
    (void)socket;
    (void)buf;
    return (g_n.data_write_rc != 0) ? g_n.data_write_rc : len;
}

int lftpd_inet_read(int socket, void *buf, int len)
{
    int n;

    (void)socket;
    (void)buf;
    if (g_n.rx_left <= 0) {
        return 0;                        /* 对端结束数据 */
    }
    n = (g_n.rx_left > len) ? len : g_n.rx_left;
    g_n.rx_left -= n;
    return n;
}

int lftpd_inet_listen(int port)
{
    (void)port;
    g_n.listen_calls++;
    return g_n.listen_rc;
}

int lftpd_inet_get_socket_port(int socket)
{
    (void)socket;
    return g_n.port;
}

int lftpd_inet_accept(int socket)
{
    (void)socket;
    return -1;
}

int lftpd_inet_accept_timeout(int socket, int timeout_ms)
{
    (void)socket;
    (void)timeout_ms;
    g_n.accept_calls++;
    return g_n.accept_to_rc;
}

int lftpd_inet_close(int socket)
{
    (void)socket;
    g_n.close_calls++;
    return 0;
}

/* ===================== 假 io 层：极简内存视图 ===================== */

typedef struct {
    int      stat_rc;
    int      is_dir;
    uint32_t size;
    int      open_read_rc;
    int      open_write_rc;
    int      write_short;              /* >0：写返回这个短值 -> 触发半成品清理 */
    int      read_left;
    int      opendir_rc;
    const char *names[4];
    uint32_t sizes[4];
    int      dirs[4];
    int      readdir_i;
    int      readdir_n;
    int      unlink_calls;
    char     last_path[128];
} lftp_io_t;

static lftp_io_t g_io;

char *lftpd_io_canonicalize_path(const char *base, const char *name)
{
    char *p = (char *)pvPortMalloc(128);

    if (p == NULL) {
        return NULL;
    }
    (void)snprintf(p, 128, "%s/%s", (base != NULL) ? base : "",
                   (name != NULL) ? name : "");
    (void)strncpy(g_io.last_path, p, sizeof(g_io.last_path) - 1u);
    return p;
}

int lftpd_io_stat(const char *path, uint32_t *p_size, int *p_is_dir)
{
    (void)path;
    if (p_size != NULL) { *p_size = g_io.size; }
    if (p_is_dir != NULL) { *p_is_dir = g_io.is_dir; }
    return g_io.stat_rc;
}

int lftpd_io_open_read(const char *path) { (void)path; return g_io.open_read_rc; }
int lftpd_io_open_write(const char *path) { (void)path; return g_io.open_write_rc; }
int lftpd_io_read(int handle, void *buf, int len)
{
    int n;

    (void)handle;
    (void)buf;
    if (g_io.read_left <= 0) {
        return 0;
    }
    n = (g_io.read_left > len) ? len : g_io.read_left;
    g_io.read_left -= n;
    return n;
}
int lftpd_io_write(int handle, const void *buf, int len)
{
    (void)handle;
    (void)buf;
    return (g_io.write_short > 0) ? g_io.write_short : len;
}
void lftpd_io_close(int handle) { (void)handle; }
int lftpd_io_unlink(const char *path) { (void)path; g_io.unlink_calls++; return 0; }
void *lftpd_io_opendir(const char *path)
{
    (void)path;
    return (g_io.opendir_rc != 0) ? NULL : (void *)&g_io;
}
int lftpd_io_readdir(void *dp, char *name, int name_max, uint32_t *p_size, int *p_is_dir)
{
    int i = g_io.readdir_i;

    (void)dp;
    if (i >= g_io.readdir_n) {
        return -1;
    }
    g_io.readdir_i++;
    (void)strncpy(name, g_io.names[i], (size_t)name_max - 1);
    name[name_max - 1] = '\0';
    *p_size = g_io.sizes[i];
    *p_is_dir = g_io.dirs[i];
    return 0;
}
void lftpd_io_closedir(void *dp) { (void)dp; }

/* ===================== 假配置与假认证 ===================== */

static ftp_cfg_t    g_cfg;
static int          g_cfg_present = 1;
static int          g_default_pwd;
static ftp_auth_result_t g_auth_res;
static int          g_auth_calls;

const ftp_cfg_t *ftp_cfg_get(void) { return (g_cfg_present != 0) ? &g_cfg : NULL; }
int ftp_cfg_is_default_pwd(void) { return g_default_pwd; }

ftp_auth_result_t ftp_auth_check(const ftp_auth_creds_t *p_creds, uint8_t user_ok,
                                 const char *p_pwd, ftp_auth_state_t *p_state,
                                 uint32_t now_ms)
{
    (void)p_creds;
    (void)user_ok;
    (void)p_pwd;
    (void)p_state;
    (void)now_ms;
    g_auth_calls++;
    return g_auth_res;
}

int ftp_auth_user_match(const char *p_cfg_user, const char *p_given)
{
    if ((p_cfg_user == NULL) || (p_given == NULL)) {
        return 0;
    }
    return (strcmp(p_cfg_user, p_given) == 0) ? 1 : 0;
}

/* ===================== 假 net 与 OS ===================== */

static uint32_t g_tick;
static int      g_sockname_rc;      /* net_getsockname 的返回码（PASV 分支注入失败用） */

uint32_t xTaskGetTickCount(void) { return g_tick; }

/* lftpd_task_wd_beat 的真实定义在 lftpd_inet.c 里（__weak，供 lftpd.c 覆盖），本模块
   不拖那一层进来，故在此给计数假件——正好把"传输循环每轮喂狗"变成可断言的事。 */
static int g_wd_beats;
void lftpd_task_wd_beat(void) { g_wd_beats++; }
void vTaskDelay(TickType_t t)
{
    (void)t;
    g_n.delay_calls++;
    if (g_n.delay_calls > 200) {
        printf("  ABORT loop runaway (>200 rounds)\n");
        fflush(stdout);
        exit(2);
    }
}

int net_getsockname(int sockfd, struct net_sockaddr *addr, int *addrlen)
{
    struct net_sockaddr_in *a = (struct net_sockaddr_in *)addr;

    (void)sockfd;
    (void)addrlen;
    a->sin_addr.s_addr = 0x011FA8C0u;      /* 192.168.31.1 的宿主序表示（假件自定） */
    a->sin_port = net_htons(21u);
    return g_sockname_rc;
}
int net_getpeername(int sockfd, struct net_sockaddr *addr, int *addrlen)
{
    (void)sockfd;
    (void)addr;
    (void)addrlen;
    return 0;
}
uint16_t net_htons(uint16_t v) { return (uint16_t)((v >> 8) | (v << 8)); }
uint16_t net_ntohs(uint16_t v) { return net_htons(v); }
uint32_t net_htonl(uint32_t v)
{
    return ((v & 0xFFu) << 24) | (((v >> 8) & 0xFFu) << 16) |
           (((v >> 16) & 0xFFu) << 8) | ((v >> 24) & 0xFFu);
}
char *net_inet_ntoa(uint32_t in, char *p_buf)
{
    (void)snprintf(p_buf, 16, "%u.%u.%u.%u", (unsigned)(in & 0xFFu),
                   (unsigned)((in >> 8) & 0xFFu), (unsigned)((in >> 16) & 0xFFu),
                   (unsigned)((in >> 24) & 0xFFu));
    return p_buf;
}

/* ===================== 复位与驱动 ===================== */

static lftpd_client_t g_cli;

static void reset_all(void)
{
    (void)memset(&g_n, 0, sizeof(g_n));
    (void)memset(&g_io, 0, sizeof(g_io));
    g_n.string_rc = 0;
    g_n.listen_rc = 20;
    g_n.port = 5000;
    g_n.accept_to_rc = 21;             /* 默认数据通道能连上 */
    g_n.data_write_rc = 0;
    g_io.stat_rc = 0;
    g_io.is_dir = 1;
    g_io.size = 7u;
    g_io.open_read_rc = 0;
    g_io.open_write_rc = 0;
    g_io.read_left = 0;
    g_io.readdir_n = 0;
    g_cfg_present = 1;
    (void)memset(&g_cfg, 0, sizeof(g_cfg));
    (void)strcpy(g_cfg.user, "admin");
    g_cfg.write_en = 1u;
    g_auth_res = FTP_AUTH_OK;
    g_default_pwd = 0;
    g_tick = 0u;
    g_wd_beats = 0;
    g_free_calls = 0;
    g_pool_used = 0u;
    g_lg_info_count = 0;
    g_lg_error_count = 0;
    g_lg_debug_count = 0;
    g_sockname_rc = 0;
    (void)memset(&g_cli, 0, sizeof(g_cli));
    (void)strcpy(g_cli.directory, "/");
    g_cli.socket = 10;
    g_cli.data_socket = -1;
    /* 不写死字段名：认证状态的结构由 lftpd_auth.h 定义，本模块只把它当黑盒清零
       （口令/锁定逻辑有 test/host/ftp_auth 的 10 条专测，这里不重复验）。 */
    (void)memset(&s_auth_state, 0, sizeof(s_auth_state));
}

static void feed(const char *l0, const char *l1, const char *l2, const char *l3)
{
    int n = 0;

    g_n.lines[n] = l0; g_n.line_ret[n++] = 0;
    if (l1 != NULL) { g_n.lines[n] = l1; g_n.line_ret[n++] = 0; }
    if (l2 != NULL) { g_n.lines[n] = l2; g_n.line_ret[n++] = 0; }
    if (l3 != NULL) { g_n.lines[n] = l3; g_n.line_ret[n++] = 0; }
    g_n.line_n = n;
}

static const char *rep(int k) { return (k < g_n.reply_n) ? g_n.replies[k] : ""; }
static int rep_has(const char *prefix)
{
    int i;
    int c = 0;

    for (i = 0; i < g_n.reply_n; i++) {
        if (strncmp(g_n.replies[i], prefix, strlen(prefix)) == 0) {
            c++;
        }
    }
    return c;
}

/* ===================== 控制通道闸门 ===================== */

static void tc_gates(void)
{
    printf("-- TC-LFTPD-001..008 control channel gates --\n");
    reset_all();
    feed("RETR a.txt", "LIST", "PWD", NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("220 ") == 1) && (rep_has("530 ") == 3) &&
          (g_n.accept_calls == 0),
          "TC-LFTPD-001 before login only USER/PASS/QUIT/FEAT/SYST/NOOP pass, everything else gets 530");

    reset_all();
    feed("ABCDEFG", "NOOP", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("500 ") == 1) && (rep_has("200 ") == 1),
          "TC-LFTPD-002 a command name of 5 characters or more is rejected first (command_tmp has only 5 slots, this keeps memcpy in bounds)");

    reset_all();
    g_cli.auth_logged_in = 1;              /* 否则会被认证白名单先以 530 拦掉，测不到分派 */
    feed("FOO bar", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("502 ") == 1) && (rep_has("530 ") == 0),
          "TC-LFTPD-003 an unknown command answers 502 instead of dropping the connection");

    reset_all();
    feed("QUIT", "NOOP", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("221 ") == 1) && (rep_has("200 ") == 0) && (g_n.line_i == 1),
          "TC-LFTPD-004 after QUIT no further command is read (the session ends here)");

    reset_all();
    g_n.string_rc = -1;                      /* 220 都送不出去 */
    feed("NOOP", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((g_n.line_i == 0) && (g_lg_info_count >= 1),
          "TC-LFTPD-005 if the welcome never got through (peer already gone) finish straight away instead of spinning on reads; that trace really is INFO");

    reset_all();
    g_cli.data_socket = 33;                  /* 被动模式已开但客户端直接跑了 */
    feed("QUIT", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((g_n.close_calls == 1) && (g_cli.data_socket == -1),
          "TC-LFTPD-006 on exit the still-open data listener must be released (a single-socket chip must not be left with a dangling socket)");

    reset_all();
    g_cli.auth_logged_in = 1;
    feed("noop", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK(rep_has("200 ") == 1, "TC-LFTPD-007 command names are case insensitive");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.opendir_rc = 0;
    g_io.readdir_n = 0;
    g_n.listen_rc = 20;
    feed("LIST", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("425 ") == 1) && (g_n.accept_calls == 0),
          "TC-LFTPD-010 a data command without passive mode set first gets 425 and never reaches accept");
}

/* ===================== 被动模式与数据通道 ===================== */

static void tc_passive(void)
{
    printf("-- TC-LFTPD-011..016 passive & data --\n");
    reset_all();
    g_cli.auth_logged_in = 1;
    /* 直调处理器：走 handle_control_channel 的话，会话退出时 cleanup 一定把被动监听
       关掉（那正是 TC-LFTPD-006 要验的行为），这里要看的是 PASV 自己留下的状态。 */
    (void)cmd_pasv(&g_cli, NULL);
    CHECK((strcmp(rep(0), "227 Entering Passive Mode (192,168,31,1,19,136).\r\n") == 0) &&
          (g_cli.data_socket == 20) && (g_n.listen_calls == 1),
          "TC-LFTPD-011 the 227 tuple: ip through htonl then high byte to low byte (dotted order), port high/low, and the passive listen handle is recorded");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_sockname_rc = -1;                       /* 问不到本机地址 */
    feed("PASV", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("425 ") == 1) && (g_n.close_calls == 1) &&
          (g_cli.data_socket == -1),
          "TC-LFTPD-012 when the local ip is unavailable the listener just created must be closed (no half-passive mode left behind)");

    reset_all();
    g_cli.auth_logged_in = 1;
    feed("EPSV", NULL, NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK(strcmp(rep(1), "229 Entering Extended Passive Mode (|||5000|).\r\n") == 0,
          "TC-LFTPD-013 EPSV reports only the port (an IPv6 client reuses the control connection address)");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_n.listen_rc = 20;
    g_n.accept_to_rc = -1;                    /* 对端一直不开数据通道 */
    feed("PASV", "LIST", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("150 ") == 1) && (rep_has("425 ") == 1) &&
          (g_cli.data_socket == -1) && (g_n.close_calls == 1),
          "TC-LFTPD-014 a failed data accept reports 425 and closes and resets the listener instead of leaving it to the next command");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.readdir_n = 2;
    g_io.names[0] = "a.txt"; g_io.sizes[0] = 7u; g_io.dirs[0] = 0;
    g_io.names[1] = "sub";   g_io.sizes[1] = 0u; g_io.dirs[1] = 1;
    feed("PASV", "LIST", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("226 ") == 1) && (g_n.data_write_rc == 0),
          "TC-LFTPD-015 LIST success: 150 first, the directory goes out on the data socket, then 226 closes it");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.opendir_rc = 1;                      /* 目录打不开 */
    feed("PASV", "LIST", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK(rep_has("550 ") == 1, "TC-LFTPD-016 when the directory cannot be opened LIST answers 550 (not 226)");
}

/* ===================== 传输与写开关 ===================== */

static void tc_transfer(void)
{
    printf("-- TC-LFTPD-017..021 transfer & write gate --\n");
    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.read_left = 5;
    feed("PASV", "RETR a.txt", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("226 ") == 1) && (g_lg_info_count >= 1) && (g_wd_beats >= 1),
          "TC-LFTPD-017 RETR success: 226 at the end, a DOWNLOAD record is kept and the transfer loop feeds the watchdog");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.open_read_rc = -1;
    feed("PASV", "RETR gone.txt", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("450 ") == 1) && (g_lg_error_count >= 1),
          "TC-LFTPD-018 a file that cannot be opened answers 450 (a transfer failure and an invalid command must be reported apart)");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_n.rx_left = 900;
    g_io.write_short = 100;                   /* 写到一半失败 */
    feed("PASV", "STOR up.bin", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((g_io.unlink_calls == 1) && (rep_has("450 ") == 1),
          "TC-LFTPD-019 a STOR failing halfway must delete the partial file (otherwise a broken file stays on flash forever)");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_cfg.write_en = 0u;
    g_n.listen_rc = 20;
    feed("PASV", "STOR up.bin", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("550 ") == 1) && (g_n.accept_calls == 0) &&
          (g_io.open_write_rc == 0) && (g_io.unlink_calls == 0),
          "TC-LFTPD-020 with writes disabled STOR is refused before the file is touched and no data channel is opened");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_cfg.write_en = 0u;
    (void)cmd_dele(&g_cli, "a.txt");
    CHECK(rep_has("550 ") == 1, "TC-LFTPD-021 the write switch blocks DELE as well");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.is_dir = 1;
    (void)cmd_dele(&g_cli, "sub");
    CHECK((rep_has("550 ") == 1) && (g_io.unlink_calls == 0),
          "TC-LFTPD-022 DELE must not delete directories (this implementation only deletes files)");

    reset_all();
    g_cli.auth_logged_in = 1;
    g_io.is_dir = 0;
    (void)cmd_dele(&g_cli, "a.txt");
    CHECK((g_io.unlink_calls == 1) && (rep_has("250 ") == 1),
          "TC-LFTPD-022b deleting a regular file goes through unlink and answers 250");
}

/* ===================== 目录与元信息 ===================== */

static void tc_meta(void)
{
    printf("-- TC-LFTPD-023..030 cwd / size / pwd / feat --\n");
    reset_all();
    (void)cmd_cwd(&g_cli, "");
    CHECK((rep_has("550 ") == 1) && (strcmp(g_cli.directory, "/") == 0),
          "TC-LFTPD-023 CWD with an empty argument is refused and the current directory stays");

    reset_all();
    g_io.is_dir = 0;
    (void)cmd_cwd(&g_cli, "a.txt");
    CHECK(rep_has("550 ") == 1, "TC-LFTPD-023b CWD onto a regular file is refused (is_dir must really be a directory)");

    reset_all();
    g_io.is_dir = 1;
    (void)cmd_cwd(&g_cli, "logs");
    CHECK((rep_has("250 ") == 1) && (strcmp(g_cli.directory, "//logs") == 0) &&
          (g_free_calls == 1),
          "TC-LFTPD-024 a successful CWD updates the current directory and frees the path buffer (no heap leak)");

    reset_all();
    (void)cmd_cwd(&g_cli, "/");
    CHECK((rep_has("250 ") == 1) && (g_io.stat_rc == 0),
          "TC-LFTPD-024b going back to the root skips stat and succeeds directly (the root always exists)");

    reset_all();
    g_io.is_dir = 0;
    g_io.size = 12345u;
    (void)cmd_size(&g_cli, "up.bin");
    CHECK(strcmp(rep(0), "213 12345\r\n") == 0, "TC-LFTPD-025 SIZE reports the byte count");

    reset_all();
    g_io.stat_rc = -1;
    (void)cmd_size(&g_cli, "nope");
    CHECK(rep_has("550 ") == 1, "TC-LFTPD-025b when the file is missing SIZE answers 550");

    reset_all();
    (void)strcpy(g_cli.directory, "/logs");
    (void)cmd_pwd(&g_cli, NULL);
    CHECK(strcmp(rep(0), "257 \"/logs\"\r\n") == 0,
          "TC-LFTPD-026 PWD wraps the directory in double quotes (required by RFC 959)");

    reset_all();
    (void)cmd_syst(&g_cli, NULL);
    CHECK(strcmp(rep(0), "215 UNIX Type: L8\r\n") == 0,
          "TC-LFTPD-027 SYST always reports UNIX Type: L8 (clients pick their mode from it)");

    reset_all();
    (void)cmd_feat(&g_cli, NULL);
    CHECK((strncmp(rep(0), "211-", 4) == 0) && (strcmp(rep(1), "EPSV\r\n") == 0) &&
          (strcmp(rep(2), "PASV\r\n") == 0) && (strncmp(rep(5), "211 ", 4) == 0) &&
          (g_n.reply_n == 6),
          "TC-LFTPD-028 FEAT multiline: first line 211-, four capability lines without a status code, last line 211 ends it");

    reset_all();
    (void)cmd_type(&g_cli, "I");
    (void)cmd_noop(&g_cli, NULL);
    CHECK(rep_has("200 ") == 2, "TC-LFTPD-030 both TYPE and NOOP answer 200");
}

/* ===================== 登录序列 ===================== */

static void tc_login(void)
{
    printf("-- TC-LFTPD-031..033 login --\n");
    reset_all();
    feed("USER admin", "PASS good", "RETR a.txt", NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("331 ") == 1) && (rep_has("230 ") == 1) &&
          (g_cli.auth_logged_in == 1u) && (strcmp(g_cli.auth_user, "admin") == 0),
          "TC-LFTPD-031 USER records the user name and the match bit; a passing PASS switches to logged in");

    reset_all();
    g_auth_res = FTP_AUTH_FAIL;
    feed("USER admin", "PASS bad", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("530 ") == 1) && (g_cli.auth_logged_in == 0u) &&
          (g_lg_info_count >= 1),
          "TC-LFTPD-032 a wrong password gives 530 and USER must be repeated (auth_user_ok was cleared)");

    reset_all();
    g_auth_res = FTP_AUTH_LOCKED;
    g_cfg_present = 1;
    feed("USER admin", "PASS bad", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK(rep_has("530 ") == 1,
          "TC-LFTPD-033 while locked out after repeated failures it also answers only 530 (no distinguishing hint for an attacker)");

    reset_all();
    g_cfg_present = 0;                       /* 配置读不到 */
    feed("USER admin", "PASS x", NULL, NULL);
    (void)handle_control_channel(&g_cli);
    CHECK((rep_has("331 ") == 1) && (rep_has("530 ") == 1) &&
          (g_cli.auth_user_ok == 0u),
          "TC-LFTPD-034 with missing configuration USER cannot match and PASS answers 530 straight away (fail-closed)");
}

int main(void)
{
    printf("=== LFTPD Protocol Tests ===\n");

    tc_gates();
    tc_passive();
    tc_transfer();
    tc_meta();
    tc_login();

    printf("\n=== LFTPD Protocol Tests: %d/%d PASSED (failed=%d) ===\n",
           s_passed, s_total, s_failed);
    return (s_failed == 0) ? 0 : 1;
}