/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <nfc_int.h>
#include <rw_int.h>
#include <dlfcn.h>
#include <unistd.h>

#include "../includes/common.h"
#include "../includes/memutils.h"

#define T3T_MSG_FELICALITE_MC_OFFSET 0x01

char enable_selective_overload = ENABLE_NONE;
char *vulnPtr = nullptr;

bool testInProgress = false;
struct sigaction new_action, old_action;
void sigsegv_handler(int signum, siginfo_t *info, void* context) {
    if (testInProgress && info->si_signo == SIGSEGV) {
        const size_t page_size = getpagesize();
        const size_t page_mask = (~(page_size - 1));
        if (page_size) {
            char *vulnPtrGuardPage = (char *) ((size_t) vulnPtr & page_mask) + page_size;
            char *faultPage = (char *) ((size_t) info->si_addr & page_mask);
            if (faultPage == vulnPtrGuardPage) {
                (*old_action.sa_sigaction)(signum, info, context);
                return;
            }
        }
    }
    _exit(EXIT_FAILURE);
}

extern tRW_CB rw_cb;
extern tNFC_CB nfc_cb;
void rw_init(void);
tNFC_STATUS rw_t3t_select(uint8_t peer_nfcid2[NCI_RF_F_UID_LEN],
                          uint8_t mrti_check, uint8_t mrti_update);

static void (*real_GKI_freebuf)(void* ptr) = nullptr;
void *kAllocatedPointers[2];
int allocatedPointersIndex = -1;
bool kIsInitialized = false;

void init(void) {
    real_GKI_freebuf = (void (*)(void*))dlsym(RTLD_NEXT, "_Z11GKI_freebufPv");
    if (!real_GKI_freebuf) {
        return;
    }

    kIsInitialized = true;
}

void GKI_freebuf(void* ptr) {
    if (!kIsInitialized) {
        init();
    }
    if (ptr == kAllocatedPointers[0] || ptr == kAllocatedPointers[1]) {
        return;
    } else {
        real_GKI_freebuf(ptr);
    }
}

void *allocate_memory(size_t size) {
    void *ptr = memalign(16, size);
    memset(ptr, 0x0, size);
    kAllocatedPointers[++allocatedPointersIndex] = ptr;
    return ptr;
}

// borrowed from rw_i93.cc
enum {
    RW_T3T_CMD_DETECT_NDEF,
    RW_T3T_CMD_CHECK_NDEF,
    RW_T3T_CMD_UPDATE_NDEF,
    RW_T3T_CMD_CHECK,
    RW_T3T_CMD_UPDATE,
    RW_T3T_CMD_SEND_RAW_FRAME,
    RW_T3T_CMD_GET_SYSTEM_CODES,
    RW_T3T_CMD_FORMAT,
    RW_T3T_CMD_SET_READ_ONLY_SOFT,
    RW_T3T_CMD_SET_READ_ONLY_HARD,

    RW_T3T_CMD_MAX
};

// borrowed from rw_i93.cc
enum {
    RW_T3T_STATE_NOT_ACTIVATED,
    RW_T3T_STATE_IDLE,
    RW_T3T_STATE_COMMAND_PENDING
};

// borrowed from rw_i93.cc
enum {
    /* Sub states for formatting Felica-Lite */
    RW_T3T_FMT_SST_POLL_FELICA_LITE, /* Waiting for POLL Felica-Lite response (for
     formatting) */
    RW_T3T_FMT_SST_CHECK_MC_BLK, /* Waiting for Felica-Lite MC (MemoryControl)
     block-read to complete */
    RW_T3T_FMT_SST_UPDATE_MC_BLK, /* Waiting for Felica-Lite MC (MemoryControl)
     block-write to complete */
    RW_T3T_FMT_SST_UPDATE_NDEF_ATTRIB, /* Waiting for NDEF attribute block-write
     to complete */

    /* Sub states for setting Felica-Lite read only */
    RW_T3T_SRO_SST_POLL_FELICA_LITE, /* Waiting for POLL Felica-Lite response (for
     setting read only) */
    RW_T3T_SRO_SST_UPDATE_NDEF_ATTRIB, /* Waiting for NDEF attribute block-write
     to complete */
    RW_T3T_SRO_SST_CHECK_MC_BLK, /* Waiting for Felica-Lite MC (MemoryControl)
     block-read to complete */
    RW_T3T_SRO_SST_UPDATE_MC_BLK /* Waiting for Felica-Lite MC (MemoryControl)
     block-write to complete */
};

void cback(tRW_EVENT event __attribute__((unused)),
           tRW_DATA* p_data __attribute__((unused))) {
}

int main() {
    sigemptyset(&new_action.sa_mask);
    new_action.sa_flags = SA_SIGINFO;
    new_action.sa_sigaction = sigsegv_handler;
    sigaction(SIGSEGV, &new_action, &old_action);
    tRW_T3T_CB* p_t3t = &rw_cb.tcb.t3t;

    GKI_init();
    rw_init();

    uint8_t peer_nfcid2[NCI_RF_F_UID_LEN];
    uint8_t mrti_check = 1, mrti_update = 1;
    enable_selective_overload = ENABLE_MEMALIGN_CHECK;
    if (rw_t3t_select(peer_nfcid2, mrti_check, mrti_update) != NFC_STATUS_OK) {
        return EXIT_FAILURE;
    }

    tNFC_CONN *p_data = (tNFC_CONN *) allocate_memory(sizeof(tNFC_CONN));
    if (!p_data) {
        return EXIT_FAILURE;
    }
    p_data->data.p_data = (NFC_HDR *) allocate_memory(sizeof(NFC_HDR) * 4);
    enable_selective_overload = ENABLE_FREE_CHECK | ENABLE_REALLOC_CHECK;
    if (!(p_data->data.p_data)) {
        free(p_data);
        return EXIT_FAILURE;
    }
    vulnPtr = (char *)p_data->data.p_data;
    p_data->status = NFC_STATUS_OK;

    p_t3t->cur_cmd = RW_T3T_CMD_SET_READ_ONLY_HARD;
    p_t3t->rw_state = RW_T3T_STATE_COMMAND_PENDING;
    p_t3t->rw_substate = RW_T3T_SRO_SST_CHECK_MC_BLK;

    NFC_HDR* p_msg = (p_data->data).p_data;
    p_msg->len = T3T_MSG_RSP_COMMON_HDR_LEN;

    uint8_t* p_t3t_rsp = (uint8_t*) (p_msg + 1) + (p_msg->offset + 1);
    p_t3t_rsp[T3T_MSG_RSP_OFFSET_RSPCODE] = T3T_MSG_OPC_CHECK_RSP;
    p_t3t_rsp[T3T_MSG_RSP_OFFSET_STATUS1] = T3T_MSG_RSP_STATUS_OK;

    uint8_t* p_mc = &p_t3t_rsp[T3T_MSG_RSP_OFFSET_CHECK_DATA];
    p_mc[T3T_MSG_FELICALITE_MC_OFFSET_SYS_OP] = T3T_MSG_FELICALITE_MC_OFFSET;

    tNFC_CONN_CB* p_cb = &nfc_cb.conn_cb[NFC_RF_CONN_ID];
    tNFC_CONN_EVT event = NFC_DATA_CEVT;
    TIMER_LIST_ENT pFirst = { };
    nfc_cb.quick_timer_queue.p_first = &pFirst;

    rw_cb.p_cback = &cback;
    testInProgress = true;
    p_cb->p_cback(0, event, p_data);
    testInProgress = false;

    free(p_data->data.p_data);
    free(p_data);

    return EXIT_SUCCESS;
}