/*
 * Copyright 2015 The Android Open Source Project
 * Copyright (C) 2015 Freescale Semiconductor, Inc.
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <assert.h>

#include <hardware/hardware.h>
#include <hardware/boot_control.h>
#include <cutils/log.h>
#include <cutils/properties.h>
#include <external/zlib/zlib.h>
#include "bootctl.h"

static uint32_t g_dwCurSlot;
static bool g_bInited;
static const char *g_aSlotSuffix[SLOT_NUM] = { "_a", "_b" };

#define INIT_CHECK do{ if(!g_bInited) {ALOGE("%s, module not inited", __FUNCTION__); return -EINVAL;} }while(0)
#define SLOT_CHECK(slot, retval) do { if(slot >= SLOT_NUM) {ALOGE("%s, slot %d too large", __FUNCTION__, slot); return retval;} }while(0)
#define RET_CHECK(ret, func) do { if(ret < 0){ ALOGE("%s, %s failed", __FUNCTION__, #func); return ret;} }while(0)
#define TRACE ALOGI("enter %s", __FUNCTION__)

void bootctl_init(struct boot_control_module *module);
unsigned bootctl_getNumberSlots(struct boot_control_module *module);
unsigned bootctl_getCurrentSlot(struct boot_control_module *module);
int bootctl_markBootSuccessful(struct boot_control_module *module);
int bootctl_setActiveBootSlot(struct boot_control_module *module, unsigned slot);
int bootctl_setSlotAsUnbootable(struct boot_control_module *module, unsigned slot);
int bootctl_isSlotBootable(struct boot_control_module *module, unsigned slot);
const char* bootctl_getSuffix(struct boot_control_module *module, unsigned slot);

static struct hw_module_methods_t bootctl_module_methods = {
        open: NULL
};

boot_control_module_t HAL_MODULE_INFO_SYM = {
        common: {
                tag: HARDWARE_MODULE_TAG,
                module_api_version: BOOT_CONTROL_MODULE_API_VERSION_0_1,
                hal_api_version: 0,
                id: BOOT_CONTROL_HARDWARE_MODULE_ID,
                name: "Freescale Boot Control",
                author: "Freescale Semiconductor Inc.",
                methods: &bootctl_module_methods,
                dso: NULL,
                reserved: {0}
        },
        init: bootctl_init,
        getNumberSlots: bootctl_getNumberSlots,
        getCurrentSlot: bootctl_getCurrentSlot,
        markBootSuccessful: bootctl_markBootSuccessful,
        setActiveBootSlot: bootctl_setActiveBootSlot,
        setSlotAsUnbootable: bootctl_setSlotAsUnbootable,
        isSlotBootable: bootctl_isSlotBootable,
        getSuffix: bootctl_getSuffix,
        reserved: {0}
};

static int crcCheck(TBootCtl *ptBootCtl) {
    uint32_t crc = 0;
    uint8_t *pData = NULL;
    uint32_t len = 0;

    if(ptBootCtl == NULL)
        return -EINVAL;

    pData = (uint8_t *)ptBootCtl + CRC_DATA_OFFSET;
    len = sizeof(TBootCtl) - CRC_DATA_OFFSET;

    crc = crc32(0, pData, len);
    if(crc != ptBootCtl->m_crc) {
        ALOGE("crcCheck failed, calcuated %d, read %d\n", crc, ptBootCtl->m_crc);
        return -EINVAL;
    }

    return 0;
}

static int crcSet(TBootCtl *ptBootCtl) {
    uint32_t crc = 0;
    uint8_t *pData = NULL;
    uint32_t len = 0;

    if(ptBootCtl == NULL)
        return -EINVAL;

    pData = (uint8_t *)ptBootCtl + CRC_DATA_OFFSET;
    len = sizeof(TBootCtl) - CRC_DATA_OFFSET;

    crc = crc32(0, pData, len);
    ptBootCtl->m_crc = crc;

    return 0;
}

void bootctl_init(struct boot_control_module *module) {
    int i;

    TRACE;

    if(g_bInited) {
        ALOGI("bootctl_init already called\n");
        return;
    }

    char propbuf[PROPERTY_VALUE_MAX];

    // Get the suffix from the kernel commandline
    property_get("ro.boot.slot_suffix", propbuf, "");
    if (propbuf[0] == '\0') {
        ALOGE("property_get ro.boot.slot_suffix failed\n");
        return;
    }

    ALOGI("slot suffix is %s\n", propbuf);

    for(i = 0; i < SLOT_NUM; i++) {
        if(strcmp(propbuf, g_aSlotSuffix[i]) == 0)
            break;
    }

    if(i >= SLOT_NUM) {
        ALOGE("slot suffix %s not valid\n", propbuf);
        return;
    }

    g_dwCurSlot = i;
    g_bInited = true;

    return;
}

unsigned bootctl_getNumberSlots(struct boot_control_module *module)
{
    TRACE;
    return  SLOT_NUM;
}

unsigned bootctl_getCurrentSlot(struct boot_control_module *module)
{
    TRACE;

    INIT_CHECK;
    return  g_dwCurSlot;
}

//return fd
static int bootctl_load(TBootCtl *ptBootCtl, bool read_only) {
    int fd = -1;
    int ret = 0;
    char *pMagic = NULL;

    if(ptBootCtl == NULL)
        return -EINVAL;

    fd = open(MISC_PARTITION, read_only ? O_RDONLY : O_RDWR);
    if(fd < 0) {
        ALOGE("%s, open %s failed, fd %d, errno %d", __FUNCTION__, MISC_PARTITION, fd, errno);
        return -errno;
    }

    lseek(fd, BOOTCTRL_OFFSET, SEEK_SET);

    do {
        ret = read(fd, ptBootCtl, sizeof(TBootCtl));
    } while (ret == -1 && errno == EAGAIN);

    if (ret == -1) {
        close(fd);
        ALOGE("%s, read failed, errno %d", __FUNCTION__, errno);
        return -errno;
    }

    // Read on block devices on Linux are never partial so fine to assert everything was read.
    assert(ret == sizeof(TBootCtl));

    pMagic = ptBootCtl->m_magic;
    if(!((pMagic[0] == '\0') && (pMagic[1] == 'F') && (pMagic[2] == 'S') && (pMagic[3] == 'L')))
    {
        close(fd);
        ALOGE("%s, magic error, 0x%02x 0x%02x 0x%02x 0x%02x",
            __FUNCTION__, pMagic[0], pMagic[1], pMagic[2], pMagic[3]);
        return -EINVAL;
    }

    ret = crcCheck(ptBootCtl);
    if(ret) {
        close(fd);
        ALOGE("%s, crcCheck failed", __FUNCTION__);
        return ret;
    }

    return fd;
}

static int bootctl_store(int fd, TBootCtl *ptBootCtl) {
    int ret = 0;

    if((fd < 0) || (ptBootCtl == NULL))
        return -EINVAL;

    crcSet(ptBootCtl);

    lseek(fd, BOOTCTRL_OFFSET, SEEK_SET);

    do {
        ret = write(fd, ptBootCtl, sizeof(TBootCtl));
    } while (ret == -1 && errno == EAGAIN);

    if (ret == -1) {
        close(fd);
        ALOGE("%s, write failed, errno %d", __FUNCTION__, errno);
        return -errno;
    }

    // Writes on block devices on Linux are never partial so fine to assert everything was written.
    assert(ret == sizeof(TBootCtl));

    ret = fsync(fd);
    if (ret == -1) {
       close(fd);
       ALOGE("%s, fsync failed, errno %d", __FUNCTION__, errno);
       return -errno;
    }

    close(fd);

    return 0;
}

int bootctl_markBootSuccessful(struct boot_control_module *module)
{
    int ret = 0;
    int fd = 0;
    TBootCtl tBootCtl;

    TRACE;
    INIT_CHECK;

    ALOGI("bootctl_markBootSuccessful curSlot %d", g_dwCurSlot);

    fd = bootctl_load(&tBootCtl, false);
    RET_CHECK(fd, bootctl_load);

    tBootCtl.m_aSlotMeta[g_dwCurSlot].m_BootSuc = 1;

    ret = bootctl_store(fd, &tBootCtl);
    return ret;
}

int bootctl_setActiveBootSlot(struct boot_control_module *module, unsigned slot)
{
    int ret = 0;
    int fd = 0;
    TBootCtl tBootCtl;

    TRACE;
    INIT_CHECK;
    SLOT_CHECK(slot, -EINVAL);

    if(slot == g_dwCurSlot) {
        ALOGI("%s, !!! warning, active slot is same as curSlot %d", __FUNCTION__, slot);
    }

    fd = bootctl_load(&tBootCtl, false);
    RET_CHECK(fd, bootctl_load);

    tBootCtl.m_aSlotMeta[slot].m_BootSuc = 0;
    tBootCtl.m_aSlotMeta[slot].m_Priority = 15;
    tBootCtl.m_aSlotMeta[slot].m_TryRemain = 7;

    // lower other slot priority
    for(uint32_t i = 0; i < SLOT_NUM; i++) {
        if(i == slot)
            continue;

        if(tBootCtl.m_aSlotMeta[i].m_Priority >= 15)
            tBootCtl.m_aSlotMeta[i].m_Priority = 14;
    }

    ret = bootctl_store(fd, &tBootCtl);
    return ret;
}

int bootctl_setSlotAsUnbootable(struct boot_control_module *module, unsigned slot)
{
    int retVal = 0;
    int ret = 0;
    int fd = 0;
    TBootCtl tBootCtl;

    TRACE;
    INIT_CHECK;
    SLOT_CHECK(slot, -EINVAL);

    if(slot == g_dwCurSlot) {
        ALOGI("%s, !!! warning, set current slot %d unbootable", __FUNCTION__, slot);
    }

    fd = bootctl_load(&tBootCtl, false);
    RET_CHECK(fd, bootctl_load);

    tBootCtl.m_aSlotMeta[slot].m_BootSuc = 0;
    tBootCtl.m_aSlotMeta[slot].m_Priority = 0;
    tBootCtl.m_aSlotMeta[slot].m_TryRemain = 0;

    ret = bootctl_store(fd, &tBootCtl);
    return ret;
}

int bootctl_isSlotBootable(struct boot_control_module *module, unsigned slot)
{
    int ret = 0;
    int fd = 0;
    TBootCtl tBootCtl;

    TRACE;
    INIT_CHECK;
    SLOT_CHECK(slot, -EINVAL);

    fd = bootctl_load(&tBootCtl, true);
    RET_CHECK(fd, bootctl_load);

    if((tBootCtl.m_aSlotMeta[slot].m_BootSuc > 0) || (tBootCtl.m_aSlotMeta[slot].m_TryRemain > 0))
        ret = 1;

    close(fd);

    return ret;
}

const char* bootctl_getSuffix(struct boot_control_module *module, unsigned slot)
{
    TRACE;
    SLOT_CHECK(slot, NULL);

    return g_aSlotSuffix[slot];
}