/*
 * Copyright (c) 2016 MariaDB Corporation Ab
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file and at www.mariadb.com/bsl.
 *
 * Change Date: 2019-07-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2 or later of the General
 * Public License.
 */

/**
 * @file utils.c - General utility functions
 *
 * @verbatim
 * Revision History
 *
 * Date         Who                     Description
 * 10-06-2013   Massimiliano Pinto      Initial implementation
 * 12-06-2013   Massimiliano Pinto      Read function trought
 *                                      the gwbuff strategy
 * 13-06-2013   Massimiliano Pinto      MaxScale local authentication
 *                                      basics
 * 02-09-2014   Martin Brampton         Replaced C++ comments by C comments
 *
 * @endverbatim
 */

#include <maxscale/utils.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <regex.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <openssl/sha.h>
#include <maxscale/alloc.h>
#include <maxscale/dcb.h>
#include <maxscale/log_manager.h>
#include <maxscale/pcre2.h>
#include <maxscale/poll.h>
#include <maxscale/random_jkiss.h>
#include <maxscale/secrets.h>
#include <maxscale/session.h>

#if !defined(PATH_MAX)
# if defined(__USE_POSIX)
#   define PATH_MAX _POSIX_PATH_MAX
# else
#   define PATH_MAX 256
# endif
#endif

#define MAX_ERROR_MSG PATH_MAX

/* used in the hex2bin function */
#define char_val(X) (X >= '0' && X <= '9' ? X-'0' :     \
                     X >= 'A' && X <= 'Z' ? X-'A'+10 :  \
                     X >= 'a' && X <= 'z' ? X-'a'+10 :  \
                     '\177')

/* used in the bin2hex function */
char hex_upper[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char hex_lower[] = "0123456789abcdefghijklmnopqrstuvwxyz";

/**
 * Check if the provided pathname is POSIX-compliant. The valid characters
 * are [a-z A-Z 0-9._-].
 * @param path A null-terminated string
 * @return true if it is a POSIX-compliant pathname, otherwise false
 */
bool is_valid_posix_path(char* path)
{
    char* ptr = path;
    while (*ptr != '\0')
    {
        if (isalnum(*ptr) || *ptr == '/' || *ptr == '.' || *ptr == '-' || *ptr == '_')
        {
            ptr++;
        }
        else
        {
            return false;
        }
    }
    return true;
}

/*****************************************
 * backend read event triggered by EPOLLIN
 *****************************************/

int setnonblocking(int fd)
{
    int fl;

    if ((fl = fcntl(fd, F_GETFL, 0)) == -1)
    {
        char errbuf[MXS_STRERROR_BUFLEN];
        MXS_ERROR("Can't GET fcntl for %i, errno = %d, %s.",
                  fd,
                  errno,
                  strerror_r(errno, errbuf, sizeof(errbuf)));
        return 1;
    }

    if (fcntl(fd, F_SETFL, fl | O_NONBLOCK) == -1)
    {
        char errbuf[MXS_STRERROR_BUFLEN];
        MXS_ERROR("Can't SET fcntl for %i, errno = %d, %s",
                  fd,
                  errno,
                  strerror_r(errno, errbuf, sizeof(errbuf)));
        return 1;
    }
    return 0;
}


char *gw_strend(register const char *s)
{
    while (*s++)
    {
        ;
    }
    return (char*) (s - 1);
}

/*****************************************
 * generate a random char
 *****************************************/
static char gw_randomchar()
{
    return (char)((random_jkiss() % 78) + 30);
}

/*****************************************
 * generate a random string
 * output must be pre allocated
 *****************************************/
int gw_generate_random_str(char *output, int len)
{
    int i;

    for (i = 0; i < len; ++i )
    {
        output[i] = gw_randomchar();
    }

    output[len] = '\0';

    return 0;
}

/*****************************************
 * hex string to binary data
 * output must be pre allocated
 *****************************************/
int gw_hex2bin(uint8_t *out, const char *in, unsigned int len)
{
    const char *in_end = in + len;

    if (len == 0 || in == NULL)
    {
        return 1;
    }

    while (in < in_end)
    {
        register unsigned char b1 = char_val(*in);
        uint8_t b2 = 0;
        in++;
        b2 =  (b1 << 4) | char_val(*in);
        *out++ = b2;

        in++;
    }

    return 0;
}

/*****************************************
 * binary data to hex string
 * output must be pre allocated
 *****************************************/
char *gw_bin2hex(char *out, const uint8_t *in, unsigned int len)
{
    const uint8_t *in_end = in + len;
    if (len == 0 || in == NULL)
    {
        return NULL;
    }

    for (; in != in_end; ++in)
    {
        *out++ = hex_upper[((uint8_t) * in) >> 4];
        *out++ = hex_upper[((uint8_t) * in) & 0x0F];
    }
    *out = '\0';

    return out;
}

/****************************************************
 * fill a preallocated buffer with XOR(str1, str2)
 * XOR between 2 equal len strings
 * note that XOR(str1, XOR(str1 CONCAT str2)) == str2
 * and that  XOR(str1, str2) == XOR(str2, str1)
 *****************************************************/
void gw_str_xor(uint8_t *output, const uint8_t *input1, const uint8_t *input2, unsigned int len)
{
    const uint8_t *input1_end = NULL;
    input1_end = input1 + len;

    while (input1 < input1_end)
    {
        *output++ = *input1++ ^ *input2++;
    }

    *output = '\0';
}

/**********************************************************
 * fill a 20 bytes preallocated with SHA1 digest (160 bits)
 * for one input on in_len bytes
 **********************************************************/
void gw_sha1_str(const uint8_t *in, int in_len, uint8_t *out)
{
    unsigned char hash[SHA_DIGEST_LENGTH];

    SHA1(in, in_len, hash);
    memcpy(out, hash, SHA_DIGEST_LENGTH);
}

/********************************************************
 * fill 20 bytes preallocated with SHA1 digest (160 bits)
 * for two inputs, in_len and in2_len bytes
 ********************************************************/
void gw_sha1_2_str(const uint8_t *in, int in_len, const uint8_t *in2, int in2_len, uint8_t *out)
{
    SHA_CTX context;
    unsigned char hash[SHA_DIGEST_LENGTH];

    SHA1_Init(&context);
    SHA1_Update(&context, in, in_len);
    SHA1_Update(&context, in2, in2_len);
    SHA1_Final(hash, &context);

    memcpy(out, hash, SHA_DIGEST_LENGTH);
}


/**
 * node Gets errno corresponding to latest socket error
 *
 * Parameters:
 * @param fd - in, use
 *          socket to examine
 *
 * @return errno
 *
 *
 */
int gw_getsockerrno(int fd)
{
    int eno = 0;
    socklen_t elen = sizeof(eno);

    if (fd <= 0)
    {
        goto return_eno;
    }

    if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&eno, &elen) != 0)
    {
        eno = 0;
    }

return_eno:
    return eno;
}

/**
 * Create a HEX(SHA1(SHA1(password)))
 *
 * @param password      The password to encrypt
 * @return              The new allocated encrypted password, that the caller must free
 *
 */
char *create_hex_sha1_sha1_passwd(char *passwd)
{
    uint8_t hash1[SHA_DIGEST_LENGTH] = "";
    uint8_t hash2[SHA_DIGEST_LENGTH] = "";
    char *hexpasswd = NULL;

    if ((hexpasswd = (char *)MXS_CALLOC(SHA_DIGEST_LENGTH * 2 + 1, 1)) == NULL)
    {
        return NULL;
    }

    /* hash1 is SHA1(real_password) */
    gw_sha1_str((uint8_t *)passwd, strlen(passwd), hash1);

    /* hash2 is the SHA1(input data), where input_data = SHA1(real_password) */
    gw_sha1_str(hash1, SHA_DIGEST_LENGTH, hash2);

    /* dbpass is the HEX form of SHA1(SHA1(real_password)) */
    gw_bin2hex(hexpasswd, hash2, SHA_DIGEST_LENGTH);

    return hexpasswd;
}

/**
 * Remove duplicate and trailing forward slashes from a path.
 * @param path Path to clean up
 */
bool clean_up_pathname(char *path)
{
    char *data = path;
    size_t len = strlen(path);

    if (len > PATH_MAX)
    {
        MXS_ERROR("Pathname too long: %s", path);
        return false;
    }

    while (*data != '\0')
    {
        if (*data == '/')
        {
            if (*(data + 1) == '/')
            {
                memmove(data, data + 1, len);
                len--;
            }
            else if (*(data + 1) == '\0' && data != path)
            {
                *data = '\0';
            }
            else
            {
                data++;
                len--;
            }
        }
        else
        {
            data++;
            len--;
        }
    }

    return true;
}

/**
 * @brief Internal helper function for mkdir_all()
 *
 * @param path Path to create
 * @param mask Bitmask to use
 * @return True if directory exists or it was successfully created, false on error
 */
static bool mkdir_all_internal(char *path, mode_t mask)
{
    bool rval = false;

    if (mkdir(path, mask) == -1 && errno != EEXIST)
    {
        if (errno == ENOENT)
        {
            /** Try to create the parent directory */
            char *ndir = strrchr(path, '/');
            if (ndir)
            {
                *ndir = '\0';
                if (mkdir_all_internal(path, mask))
                {
                    /** Creation of the parent directory was successful, try to
                     * create the directory again */
                    *ndir = '/';
                    if (mkdir(path, mask) == 0)
                    {
                        rval = true;
                    }
                    else
                    {
                        char err[MXS_STRERROR_BUFLEN];
                        MXS_ERROR("Failed to create directory '%s': %d, %s",
                                  path, errno, strerror_r(errno, err, sizeof(err)));
                    }
                }
            }
        }
        else
        {
            char err[MXS_STRERROR_BUFLEN];
            MXS_ERROR("Failed to create directory '%s': %d, %s",
                      path, errno, strerror_r(errno, err, sizeof(err)));
        }
    }
    else
    {
        rval = true;
    }

    return rval;
}

/**
 * @brief Create a directory and any parent directories that do not exist
 *
 *
 * @param path Path to create
 * @param mask Bitmask to use
 * @return True if directory exists or it was successfully created, false on error
 */
bool mxs_mkdir_all(const char *path, int mask)
{
    char local_path[strlen(path) + 1];
    strcpy(local_path, path);

    if (local_path[sizeof(local_path) - 2] == '/')
    {
        local_path[sizeof(local_path) - 2] = '\0';
    }

    return mkdir_all_internal(local_path, (mode_t)mask);
}

/**
 * Trim leading and trailing whitespace from a string
 *
 * @param str String to trim
 * @return    Trimmed string
 */
char* trim(char *str)
{
    char* ptr = strchr(str, '\0') - 1;

    while (ptr > str && isspace(*ptr))
    {
        ptr--;
    }

    if (isspace(*(ptr + 1)))
    {
        *(ptr + 1) = '\0';
    }

    ptr = str;

    while (isspace(*ptr))
    {
        ptr++;
    }

    if (ptr != str)
    {
        memmove(str, ptr, strlen(ptr) + 1);
    }

    return str;
}

/**
 * Replace all whitespace with spaces and squeeze repeating whitespace characters
 *
 * @param str String to squeeze
 * @return Squeezed string
 */
char* squeeze_whitespace(char* str)
{
    char* store = str;
    char* ptr = str;

    /** Remove leading whitespace */
    while (isspace(*ptr) && *ptr != '\0')
    {
        ptr++;
    }

    /** Squeeze all repeating whitespace */
    while (*ptr != '\0')
    {
        while (isspace(*ptr) && isspace(*(ptr + 1)))
        {
            ptr++;
        }

        if (isspace(*ptr))
        {
            *store++ = ' ';
            ptr++;
        }
        else
        {
            *store++ = *ptr++;
        }
    }

    *store = '\0';

    /** Remove trailing whitespace */
    while (store > str && isspace(*(store - 1)))
    {
        store--;
        *store = '\0';
    }

    return str;
}

/**
 * Strip escape characters from a character string.
 * @param String to parse.
 * @return True if parsing was successful, false on errors.
 */
bool
strip_escape_chars(char* val)
{
    int cur, end;

    if (val == NULL)
    {
        return false;
    }

    end = strlen(val) + 1;
    cur = 0;

    while (cur < end)
    {
        if (val[cur] == '\\')
        {
            memmove(val + cur, val + cur + 1, end - cur - 1);
            end--;
        }
        cur++;
    }
    return true;
}

#define BUFFER_GROWTH_RATE 1.2
static pcre2_code* remove_comments_re = NULL;
static const PCRE2_SPTR remove_comments_pattern = (PCRE2_SPTR)
    "(?:`[^`]*`\\K)|(\\/[*](?!(M?!)).*?[*]\\/)|(?:#.*|--[[:space:]].*)";

/**
 * Remove SQL comments from the end of a string
 *
 * The inline executable comments are not removed due to the fact that they can
 * alter the behavior of the query.
 * @param src Pointer to the string to modify.
 * @param srcsize Pointer to a size_t variable which holds the length of the string to
 * be modified.
 * @param dest The address of the pointer where the result will be stored. If the
 * value pointed by this parameter is NULL, new memory will be allocated as needed.
 * @param Pointer to a size_t variable where the size of the result string is stored.
 * @return Pointer to new modified string or NULL if memory allocation failed.
 * If NULL is returned and the value pointed by @c dest was not NULL, no new
 * memory will be allocated, the memory pointed by @dest will be freed and the
 * contents of @c dest and @c destsize will be invalid.
 */
char* remove_mysql_comments(const char** src, const size_t* srcsize, char** dest, size_t* destsize)
{
    static const PCRE2_SPTR replace = (PCRE2_SPTR) "";
    pcre2_match_data* mdata;
    char* output = *dest;
    size_t orig_len = *srcsize;
    size_t len = output ? *destsize : orig_len;

    if (orig_len > 0)
    {
        if ((output || (output = (char*) malloc(len * sizeof (char)))) &&
            (mdata = pcre2_match_data_create_from_pattern(remove_comments_re, NULL)))
        {
            while (pcre2_substitute(remove_comments_re, (PCRE2_SPTR) * src, orig_len, 0,
                                    PCRE2_SUBSTITUTE_GLOBAL, mdata, NULL,
                                    replace, PCRE2_ZERO_TERMINATED,
                                    (PCRE2_UCHAR8*) output, &len) == PCRE2_ERROR_NOMEMORY)
            {
                char* tmp = (char*) realloc(output, (len = (size_t) (len * BUFFER_GROWTH_RATE + 1)));
                if (tmp == NULL)
                {
                    free(output);
                    output = NULL;
                    break;
                }
                output = tmp;
            }
            pcre2_match_data_free(mdata);
        }
        else
        {
            free(output);
            output = NULL;
        }
    }
    else if (output == NULL)
    {
        output = strdup(*src);
    }

    if (output)
    {
        *destsize = strlen(output);
        *dest = output;
    }

    return output;
}

static pcre2_code* replace_values_re = NULL;
static const PCRE2_SPTR replace_values_pattern = (PCRE2_SPTR) "(?i)([-=,+*/([:space:]]|\\b|[@])"
    "(?:[0-9.-]+|(?<=[@])[a-z_0-9]+)([-=,+*/)[:space:];]|$)";

/**
 * Replace literal numbers and user variables with a question mark.
 * @param src Pointer to the string to modify.
 * @param srcsize Pointer to a size_t variable which holds the length of the string to
 * be modified.
 * @param dest The address of the pointer where the result will be stored. If the
 * value pointed by this parameter is NULL, new memory will be allocated as needed.
 * @param Pointer to a size_t variable where the size of the result string is stored.
 * @return Pointer to new modified string or NULL if memory allocation failed.
 * If NULL is returned and the value pointed by @c dest was not NULL, no new
 * memory will be allocated, the memory pointed by @dest will be freed and the
 * contents of @c dest and @c destsize will be invalid.
 */
char* replace_values(const char** src, const size_t* srcsize, char** dest, size_t* destsize)
{
    static const PCRE2_SPTR replace = (PCRE2_SPTR) "$1?$2";
    pcre2_match_data* mdata;
    char* output = *dest;
    size_t orig_len = *srcsize;
    size_t len = output ? *destsize : orig_len;

    if (orig_len > 0)
    {
        if ((output || (output = (char*) malloc(len * sizeof (char)))) &&
            (mdata = pcre2_match_data_create_from_pattern(replace_values_re, NULL)))
        {
            while (pcre2_substitute(replace_values_re, (PCRE2_SPTR) * src, orig_len, 0,
                                    PCRE2_SUBSTITUTE_GLOBAL, mdata, NULL,
                                    replace, PCRE2_ZERO_TERMINATED,
                                    (PCRE2_UCHAR8*) output, &len) == PCRE2_ERROR_NOMEMORY)
            {
                char* tmp = (char*) realloc(output, (len = (size_t) (len * BUFFER_GROWTH_RATE + 1)));
                if (tmp == NULL)
                {
                    free(output);
                    output = NULL;
                    break;
                }
                output = tmp;
            }
            pcre2_match_data_free(mdata);
        }
        else
        {
            free(output);
            output = NULL;
        }
    }
    else if (output == NULL)
    {
        output = strdup(*src);
    }

    if (output)
    {
        *destsize = strlen(output);
        *dest = output;
    }

    return output;
}

/**
 * Find the given needle - user-provided literal -  and replace it with
 * replacement string. Separate user-provided literals from matching table names
 * etc. by searching only substrings preceded by non-letter and non-number.
 *
 * @param haystack      Plain text query string, not to be freed
 * @param needle        Substring to be searched, not to be freed
 * @param replacement   Replacement text, not to be freed
 *
 * @return newly allocated string where needle is replaced
 */
char* replace_literal(char* haystack, const char* needle, const char* replacement)
{
    const char* prefix = "[ ='\",\\(]"; /*< ' ','=','(',''',''"',',' are allowed before needle */
    const char* suffix = "([^[:alnum:]]|$)"; /*< alpha-num chars aren't allowed after the needle */
    char* search_re;
    char* newstr;
    regex_t re;
    regmatch_t match;
    int rc;
    size_t rlen = strlen(replacement);
    size_t nlen = strlen(needle);
    size_t hlen = strlen(haystack);

    search_re = (char *) malloc(strlen(prefix) + nlen + strlen(suffix) + 1);

    if (search_re == NULL)
    {
        char errbuf[MXS_STRERROR_BUFLEN];
        fprintf(stderr, "Regex memory allocation failed : %s\n",
                strerror_r(errno, errbuf, sizeof (errbuf)));
        newstr = haystack;
        goto retblock;
    }

    sprintf(search_re, "%s%s%s", prefix, needle, suffix);
    /** Allocate memory for new string +1 for terminating byte */
    newstr = (char *) malloc(hlen - nlen + rlen + 1);

    if (newstr == NULL)
    {
        char errbuf[MXS_STRERROR_BUFLEN];
        fprintf(stderr, "Regex memory allocation failed : %s\n",
                strerror_r(errno, errbuf, sizeof (errbuf)));
        free(search_re);
        free(newstr);
        newstr = haystack;
        goto retblock;
    }

    rc = regcomp(&re, search_re, REG_EXTENDED | REG_ICASE);
    ss_info_dassert(rc == 0, "Regex check");

    if (rc != 0)
    {
        char error_message[MAX_ERROR_MSG];
        regerror(rc, &re, error_message, MAX_ERROR_MSG);
        fprintf(stderr, "Regex error compiling '%s': %s\n",
                search_re, error_message);
        free(search_re);
        free(newstr);
        newstr = haystack;
        goto retblock;
    }
    rc = regexec(&re, haystack, 1, &match, 0);

    if (rc != 0)
    {
        free(search_re);
        free(newstr);
        regfree(&re);
        newstr = haystack;
        goto retblock;
    }
    memcpy(newstr, haystack, match.rm_so + 1);
    memcpy(newstr + match.rm_so + 1, replacement, rlen);
    /** +1 is terminating byte */
    memcpy(newstr + match.rm_so + 1 + rlen, haystack + match.rm_so + 1 + nlen, hlen - (match.rm_so + 1) - nlen + 1);

    regfree(&re);
    free(haystack);
    free(search_re);
retblock:
    return newstr;
}

static pcre2_code* replace_quoted_re = NULL;
static const PCRE2_SPTR replace_quoted_pattern = (PCRE2_SPTR)
    "(?>[^'\"]*)(?|(?:\"\\K(?:(?:(?<=\\\\)\")|[^\"])*(\"))|(?:'\\K(?:(?:(?<=\\\\)')|[^'])*(')))";

/**
 * Replace contents of single or double quoted strings with question marks.
 * @param src Pointer to the string to modify.
 * @param srcsize Pointer to a size_t variable which holds the length of the string to
 * be modified.
 * @param dest The address of the pointer where the result will be stored. If the
 * value pointed by this parameter is NULL, new memory will be allocated as needed.
 * @param Pointer to a size_t variable where the size of the result string is stored.
 * @return Pointer to new modified string or NULL if memory allocation failed.
 * If NULL is returned and the value pointed by @c dest was not NULL, no new
 * memory will be allocated, the memory pointed by @dest will be freed and the
 * contents of @c dest and @c destsize will be invalid.
 */
char* replace_quoted(const char** src, const size_t* srcsize, char** dest, size_t* destsize)
{
    static const PCRE2_SPTR replace = (PCRE2_SPTR) "?$1";
    pcre2_match_data* mdata;
    char* output = *dest;
    size_t orig_len = *srcsize;
    size_t len = output ? *destsize : orig_len;

    if (orig_len > 0)
    {
        if ((output || (output = (char*) malloc(len * sizeof (char)))) &&
            (mdata = pcre2_match_data_create_from_pattern(replace_quoted_re, NULL)))
        {
            while (pcre2_substitute(replace_quoted_re, (PCRE2_SPTR) * src, orig_len, 0,
                                    PCRE2_SUBSTITUTE_GLOBAL, mdata, NULL,
                                    replace, PCRE2_ZERO_TERMINATED,
                                    (PCRE2_UCHAR8*) output, &len) == PCRE2_ERROR_NOMEMORY)
            {
                char* tmp = (char*) realloc(output, (len = (size_t) (len * BUFFER_GROWTH_RATE + 1)));
                if (tmp == NULL)
                {
                    free(output);
                    output = NULL;
                    break;
                }
                output = tmp;
            }
            pcre2_match_data_free(mdata);
        }
        else
        {
            free(output);
            output = NULL;
        }
    }
    else if (output == NULL)
    {
        output = strdup(*src);
    }

    if (output)
    {
        *destsize = strlen(output);
        *dest = output;
    }
    else
    {
        *dest = NULL;
    }

    return output;
}

/**
 * Initialize the utils library
 *
 * This function initializes structures used in various functions.
 * @return true on success, false on error
 */
bool utils_init()
{
    bool rval = true;

    PCRE2_SIZE erroffset;
    int errcode;

    ss_info_dassert(remove_comments_re == NULL, "utils_init called multiple times");
    remove_comments_re = pcre2_compile(remove_comments_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
                                       &erroffset, NULL);
    if (remove_comments_re == NULL)
    {
        rval = false;
    }

    ss_info_dassert(replace_quoted_re == NULL, "utils_init called multiple times");
    replace_quoted_re = pcre2_compile(replace_quoted_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
                                      &erroffset, NULL);
    if (replace_quoted_re == NULL)
    {
        rval = false;
    }

    ss_info_dassert(replace_values_re == NULL, "utils_init called multiple times");
    replace_values_re = pcre2_compile(replace_values_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
                                      &erroffset, NULL);
    if (replace_values_re == NULL)
    {
        rval = false;
    }

    return rval;
}

/**
 * Close the utils library. This should be the last call to this library.
 */
void utils_end()
{
    pcre2_code_free(remove_comments_re);
    remove_comments_re = NULL;
    pcre2_code_free(replace_quoted_re);
    replace_quoted_re = NULL;
    pcre2_code_free(replace_values_re);
    replace_values_re = NULL;
}

SPINLOCK tmplock = SPINLOCK_INIT;

/*
 * Set IP address in socket structure in_addr
 *
 * @param a     Pointer to a struct in_addr into which the address is written
 * @param p     The hostname to lookup
 * @return      1 on success, 0 on failure
 */
int
setipaddress(struct in_addr *a, char *p)
{
#ifdef __USE_POSIX
    struct addrinfo *ai = NULL, hint;
    int rc;
    struct sockaddr_in *res_addr;
    memset(&hint, 0, sizeof (hint));

    hint.ai_socktype = SOCK_STREAM;

    /*
     * This is for the listening socket, matching INADDR_ANY only for now.
     * For future specific addresses bind, a dedicated routine woulbd be better
     */

    if (strcmp(p, "0.0.0.0") == 0)
    {
        hint.ai_flags = AI_PASSIVE;
        hint.ai_family = AF_UNSPEC;
        if ((rc = getaddrinfo(p, NULL, &hint, &ai)) != 0)
        {
            MXS_ERROR("Failed to obtain address for host %s, %s",
                      p,
                      gai_strerror(rc));

            return 0;
        }
    }
    else
    {
        hint.ai_flags = AI_CANONNAME;
        hint.ai_family = AF_INET;

        if ((rc = getaddrinfo(p, NULL, &hint, &ai)) != 0)
        {
            MXS_ERROR("Failed to obtain address for host %s, %s",
                      p,
                      gai_strerror(rc));

            return 0;
        }
    }

    /* take the first one */
    if (ai != NULL)
    {
        res_addr = (struct sockaddr_in *)(ai->ai_addr);
        memcpy(a, &res_addr->sin_addr, sizeof(struct in_addr));

        freeaddrinfo(ai);

        return 1;
    }
#else
    struct hostent *h;

    spinlock_acquire(&tmplock);
    h = gethostbyname(p);
    spinlock_release(&tmplock);

    if (h == NULL)
    {
        if ((a->s_addr = inet_addr(p)) == -1)
        {
            MXS_ERROR("gethostbyname failed for [%s]", p);

            return 0;
        }
    }
    else
    {
        /* take the first one */
        memcpy(a, h->h_addr, h->h_length);

        return 1;
    }
#endif
    return 0;
}


/**
 * Parse the bind config data. This is passed in a string as address:port.
 *
 * The address may be either a . separated IP address or a hostname to
 * lookup. The address 0.0.0.0 is the wildcard address for SOCKADR_ANY.
 * The ':' and port are required.
 *
 * @param config        The bind address and port separated by a ':'
 * @param addr          The sockaddr_in in which the data is written
 * @return              0 on failure
 */
int
parse_bindconfig(const char *config, struct sockaddr_in *addr)
{
    char buf[strlen(config) + 1];
    strcpy(buf, config);

    char *port = strrchr(buf, ':');
    short pnum;
    if (port)
    {
        *port = 0;
        port++;
        pnum = atoi(port);
    }
    else
    {
        return 0;
    }

    if (!strcmp(buf, "0.0.0.0"))
    {
        addr->sin_addr.s_addr = htonl(INADDR_ANY);
    }
    else
    {
        if (!inet_aton(buf, &addr->sin_addr))
        {
            struct hostent *hp = gethostbyname(buf);

            if (hp)
            {
                bcopy(hp->h_addr, &(addr->sin_addr.s_addr), hp->h_length);
            }
            else
            {
                MXS_ERROR("Failed to lookup host '%s'.", buf);
                return 0;
            }
        }
    }

    addr->sin_family = AF_INET;
    addr->sin_port = htons(pnum);
    return 1;
}

/**
 * Return the number of processors available.
 * @return Number of processors or 1 if the required definition of _SC_NPROCESSORS_CONF
 * is not found
 */
long get_processor_count()
{
    long processors = 1;
#ifdef _SC_NPROCESSORS_ONLN
    if ((processors = sysconf(_SC_NPROCESSORS_ONLN)) <= 0)
    {
        MXS_WARNING("Unable to establish the number of available cores. Defaulting to 1.");
        processors = 1;
    }
#else
#error _SC_NPROCESSORS_ONLN not available.
#endif
    return processors;
}