/*
 * mkbootimg/util.c
 *
 * Copyright (C) 2017 - 2020 bzt (bztsrc@gitlab)
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * This file is part of the BOOTBOOT Protocol package.
 * @brief Utility functions
 *
 */
#include "main.h"
#define __USE_XOPEN_EXTENDED 1  /* for readlink() */
#include <unistd.h>

#ifdef __WIN32__
int readlink(char *path, char *target, int len) {
    (void)path;
    (void)target;
    (void)len;
    return 0;
}
#endif

time_t t;
struct tm *ts;
guid_t diskguid;
char *json = NULL, *config = NULL, *kernelname = NULL, *initrd_dir[NUMARCH] = {0}, *initrd_file[NUMARCH] = {0};
char initrd_arch[NUMARCH] = {0};
int fs_len, initrd_size[NUMARCH] = {0}, initrd_gzip = 1, boot_size = 0, boot_fat = 16, disk_size = 0;
int iso9660 = 0, skipbytes = 0;
unsigned char *fs_base = NULL, *initrd_buf[NUMARCH] = {0};
unsigned long int tsize = 0, es = 0, esiz = 0, disk_align = 0;
initrd_open rd_open = NULL;
initrd_add rd_add = NULL;
initrd_close rd_close = NULL;

/**
 * Read a file entirely into memory. Don't use it with partition image files
 */
long int read_size;
unsigned char* readfileall(char *file)
{
    unsigned char *data=NULL;
    FILE *f;
    read_size=0;
    if(!file || !*file) return NULL;
    f=fopen(file,"r");
    if(f){
        fseek(f,0L,SEEK_END);
        read_size=ftell(f);
        fseek(f,0L,SEEK_SET);
        data=(unsigned char*)malloc(read_size+1);
        if(!data) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
        memset(data,0,read_size+1);
        fread(data,read_size,1,f);
        data[read_size] = 0;
        fclose(f);
    }
    return data;
}

/**
 * Convert hex string into integer
 */
unsigned int gethex(char *ptr, int len)
{
    unsigned int ret = 0;
    for(;len--;ptr++) {
        if(*ptr>='0' && *ptr<='9') {          ret <<= 4; ret += (unsigned int)(*ptr-'0'); }
        else if(*ptr >= 'a' && *ptr <= 'f') { ret <<= 4; ret += (unsigned int)(*ptr-'a'+10); }
        else if(*ptr >= 'A' && *ptr <= 'F') { ret <<= 4; ret += (unsigned int)(*ptr-'A'+10); }
        else break;
    }
    return ret;
}

/**
 * Parse a GUID in string into binary representation
 */
void getguid(char *ptr, guid_t *guid)
{
    int i;
    memset(guid, 0, sizeof(guid_t));
    if(!ptr || !*ptr || ptr[8] != '-' || ptr[13] != '-' || ptr[18] != '-') return;
    guid->Data1 = gethex(ptr, 8); ptr += 9;
    guid->Data2 = gethex(ptr, 4); ptr += 5;
    guid->Data3 = gethex(ptr, 4); ptr += 5;
    guid->Data4[0] = gethex(ptr, 2); ptr += 2;
    guid->Data4[1] = gethex(ptr, 2); ptr += 2; if(*ptr == '-') ptr++;
    for(i = 2; i < 8; i++, ptr += 2) guid->Data4[i] = gethex(ptr, 2);
}

/**
 * Recursively parse a directory
 */
void parsedir(char *directory, int parent)
{
    DIR *dir;
    struct dirent *ent;
    char full[MAXPATH];
    unsigned char *tmp;
    struct stat st;

    if ((dir = opendir(directory)) != NULL) {
        while ((ent = readdir(dir)) != NULL) {
            if(!parent && (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))) continue;
            full[0] = 0;
            strncat(full, directory, sizeof(full)-1);
            strncat(full, "/", sizeof(full)-1);
            strncat(full, ent->d_name, sizeof(full)-1);
            if(stat(full, &st)) continue;
            if(S_ISDIR(st.st_mode)) {
                (*rd_add)(&st, full + skipbytes, NULL, 0);
                if(strcmp(ent->d_name, ".") && strcmp(ent->d_name, ".."))
                    parsedir(full, parent+1);
            } else {
                tmp = NULL; read_size = 0;
                if(S_ISREG(st.st_mode)) tmp = readfileall(full); else
                if(S_ISLNK(st.st_mode)) {
                    tmp = malloc(MAXPATH); if(!tmp) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
                    read_size=readlink(full,(char*)tmp,MAXPATH-1); tmp[read_size]=0;
                }
                (*rd_add)(&st, full + skipbytes, tmp, read_size);
                if(tmp) free(tmp);
            }
        }
        closedir(dir);
    }
}

/**
 * Compress the initrd image
 */
void initrdcompress()
{
    unsigned char *initrdgz;
    unsigned long int initrdgz_len = 0;
    uint32_t crc;
    if(!initrd_gzip || !fs_len || !fs_base || (fs_base[0] == 0x1f && fs_base[1] == 0x8b)) return;
    initrdgz_len = compressBound(fs_len);
    initrdgz = malloc(initrdgz_len);
    if(!initrdgz) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
    compress2(initrdgz, &initrdgz_len, fs_base, fs_len, 9);
    if(initrdgz_len) {
        crc = crc32(0,fs_base, fs_len);
        fs_base = realloc(fs_base, initrdgz_len + 18);
        if(!fs_base) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
        memset(fs_base, 0, 10);
        fs_base[0] = 0x1f; fs_base[1] = 0x8b; fs_base[2] = 0x8; fs_base[9] = 3;
        memcpy(fs_base + 4, &t, 4);
        memcpy(fs_base + 10, initrdgz + 2, initrdgz_len - 2);
        memcpy(fs_base + 10 + initrdgz_len - 2, &crc, 4);
        memcpy(fs_base + 14 + initrdgz_len - 2, &fs_len, 4);
        fs_len = initrdgz_len - 2 + 18;
    } else
        free(initrdgz);
}

/**
 * Uncompress the initrd image
 */
void initrduncompress()
{
    unsigned char *buf;
    unsigned long int len = 0;
    if(!fs_len || !fs_base || fs_base[0] != 0x1f || fs_base[1] != 0x8b || fs_base[2] != 8) return;
    memcpy(&len, fs_base + fs_len - 4, 4);
    buf = malloc(len);
    if(!buf) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
    if(uncompress(buf,&len,fs_base,fs_len) == Z_OK && len > 0) {
        free(fs_base);
        fs_base = buf;
        fs_len = len;
    } else
        free(buf);
}

/**
 * precalculated CRC32c lookup table for polynomial 0x1EDC6F41 (castagnoli-crc)
 */
uint32_t crc32c_lookup[256]={
    0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L, 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
    0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL, 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
    0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL, 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
    0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L, 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
    0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL, 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
    0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L, 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
    0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L, 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
    0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL, 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
    0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L, 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
    0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L, 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
    0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L, 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
    0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L, 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
    0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L, 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
    0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L, 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
    0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L, 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
    0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L, 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
    0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL, 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
    0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L, 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
    0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L, 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
    0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL, 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
    0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L, 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
    0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL, 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
    0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL, 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
    0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L, 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
    0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L, 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
    0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL, 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
    0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL, 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
    0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L, 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
    0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL, 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
    0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L, 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
    0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L, 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
    0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL, 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
};
uint32_t crc32_calc(unsigned char *start,int length)
{
    uint32_t crc32_val=0;
    while(length--) crc32_val=(crc32_val>>8)^crc32c_lookup[(crc32_val&0xff)^(unsigned char)*start++];
    return crc32_val;
}