utils.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*! \file
 *
 * \brief Utility functions
 *
 * \note These are important for portability and security,
 * so please use them in favour of other routines.
 * Please consult the CODING GUIDELINES for more information.
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>
#if defined(__APPLE__)
#include <mach/mach.h>
#elif defined(__FreeBSD__)
#include <sys/thr.h>
#elif defined(__NetBSD__)
#include <lwp.h>
#endif
 
#include "asterisk/network.h"
#include "asterisk/ast_version.h"
 
#define AST_API_MODULE      /* ensure that inlinable API functions will be built in lock.h if required */
#include "asterisk/lock.h"
#include "asterisk/io.h"
#include "asterisk/md5.h"
#include "asterisk/sha1.h"
#include "asterisk/cli.h"
#include "asterisk/linkedlists.h"
#include "asterisk/astobj2.h"
 
#define AST_API_MODULE      /* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/strings.h"
 
#define AST_API_MODULE      /* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/time.h"
 
#define AST_API_MODULE      /* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/utils.h"
 
#define AST_API_MODULE
#include "asterisk/threadstorage.h"
 
#define AST_API_MODULE
#include "asterisk/config.h"
 
#define AST_API_MODULE
#include "asterisk/alertpipe.h"
 
/* These arrays are global static variables because they are only modified
 * once - in base64_init. The only purpose they have is to serve as a dictionary
 * for encoding and decoding base64 and base64 URL, so there's no harm in
 * accessing these arrays in multiple threads.
 */
static char base64[64];
static char base64url[64];
static char b2a[256];
static char b2a_url[256];
 
AST_THREADSTORAGE(inet_ntoa_buf);
 
#if !defined(HAVE_GETHOSTBYNAME_R_5) && !defined(HAVE_GETHOSTBYNAME_R_6)
 
#define ERANGE 34   /*!< duh? ERANGE value copied from web... */
#undef gethostbyname
 
AST_MUTEX_DEFINE_STATIC(__mutex);
 
/*! \brief Reentrant replacement for gethostbyname for BSD-based systems.
\note This
routine is derived from code originally written and placed in the public
domain by Enzo Michelangeli <em@em.no-ip.com> */
 
static int gethostbyname_r (const char *name, struct hostent *ret, char *buf,
                size_t buflen, struct hostent **result,
                int *h_errnop)
{
    int hsave;
    struct hostent *ph;
    ast_mutex_lock(&__mutex); /* begin critical area */
    hsave = h_errno;
 
    ph = gethostbyname(name);
    *h_errnop = h_errno; /* copy h_errno to *h_herrnop */
    if (ph == NULL) {
        *result = NULL;
    } else {
        char **p, **q;
        char *pbuf;
        int nbytes = 0;
        int naddr = 0, naliases = 0;
        /* determine if we have enough space in buf */
 
        /* count how many addresses */
        for (p = ph->h_addr_list; *p != 0; p++) {
            nbytes += ph->h_length; /* addresses */
            nbytes += sizeof(*p); /* pointers */
            naddr++;
        }
        nbytes += sizeof(*p); /* one more for the terminating NULL */
 
        /* count how many aliases, and total length of strings */
        for (p = ph->h_aliases; *p != 0; p++) {
            nbytes += (strlen(*p)+1); /* aliases */
            nbytes += sizeof(*p);  /* pointers */
            naliases++;
        }
        nbytes += sizeof(*p); /* one more for the terminating NULL */
 
        /* here nbytes is the number of bytes required in buffer */
        /* as a terminator must be there, the minimum value is ph->h_length */
        if (nbytes > buflen) {
            *result = NULL;
            ast_mutex_unlock(&__mutex); /* end critical area */
            return ERANGE; /* not enough space in buf!! */
        }
 
        /* There is enough space. Now we need to do a deep copy! */
        /* Allocation in buffer:
            from [0] to [(naddr-1) * sizeof(*p)]:
            pointers to addresses
            at [naddr * sizeof(*p)]:
            NULL
            from [(naddr+1) * sizeof(*p)] to [(naddr+naliases) * sizeof(*p)] :
            pointers to aliases
            at [(naddr+naliases+1) * sizeof(*p)]:
            NULL
            then naddr addresses (fixed length), and naliases aliases (asciiz).
        */
 
        *ret = *ph;   /* copy whole structure (not its address!) */
 
        /* copy addresses */
        q = (char **)buf; /* pointer to pointers area (type: char **) */
        ret->h_addr_list = q; /* update pointer to address list */
        pbuf = buf + ((naddr + naliases + 2) * sizeof(*p)); /* skip that area */
        for (p = ph->h_addr_list; *p != 0; p++) {
            memcpy(pbuf, *p, ph->h_length); /* copy address bytes */
            *q++ = pbuf; /* the pointer is the one inside buf... */
            pbuf += ph->h_length; /* advance pbuf */
        }
        *q++ = NULL; /* address list terminator */
 
        /* copy aliases */
        ret->h_aliases = q; /* update pointer to aliases list */
        for (p = ph->h_aliases; *p != 0; p++) {
            strcpy(pbuf, *p); /* copy alias strings */
            *q++ = pbuf; /* the pointer is the one inside buf... */
            pbuf += strlen(*p); /* advance pbuf */
            *pbuf++ = 0; /* string terminator */
        }
        *q++ = NULL; /* terminator */
 
        strcpy(pbuf, ph->h_name); /* copy alias strings */
        ret->h_name = pbuf;
        pbuf += strlen(ph->h_name); /* advance pbuf */
        *pbuf++ = 0; /* string terminator */
 
        *result = ret;  /* and let *result point to structure */
 
    }
    h_errno = hsave;  /* restore h_errno */
    ast_mutex_unlock(&__mutex); /* end critical area */
 
    return (*result == NULL); /* return 0 on success, non-zero on error */
}
 
 
#endif
 
/*! \brief Re-entrant (thread safe) version of gethostbyname that replaces the
   standard gethostbyname (which is not thread safe)
*/
struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp)
{
#ifndef HAVE_GETHOSTBYNAME_R_5
    int res;
#endif
    int herrno;
    int dots = 0;
    const char *s;
    struct hostent *result = NULL;
    /* Although it is perfectly legitimate to lookup a pure integer, for
       the sake of the sanity of people who like to name their peers as
       integers, we break with tradition and refuse to look up a
       pure integer */
    s = host;
    while (s && *s) {
        if (*s == '.')
            dots++;
        else if (!isdigit(*s))
            break;
        s++;
    }
    if (!s || !*s) {
        /* Forge a reply for IP's to avoid octal IP's being interpreted as octal */
        if (dots != 3)
            return NULL;
        memset(hp, 0, sizeof(struct ast_hostent));
        hp->hp.h_addrtype = AF_INET;
        hp->hp.h_addr_list = (void *) hp->buf;
        hp->hp.h_addr = hp->buf + sizeof(void *);
        /* For AF_INET, this will always be 4 */
        hp->hp.h_length = 4;
        if (inet_pton(AF_INET, host, hp->hp.h_addr) > 0)
            return &hp->hp;
        return NULL;
 
    }
#ifdef HAVE_GETHOSTBYNAME_R_5
    result = gethostbyname_r(host, &hp->hp, hp->buf, sizeof(hp->buf), &herrno);
 
    if (!result || !hp->hp.h_addr_list || !hp->hp.h_addr_list[0])
        return NULL;
#else
    res = gethostbyname_r(host, &hp->hp, hp->buf, sizeof(hp->buf), &result, &herrno);
 
    if (res || !result || !hp->hp.h_addr_list || !hp->hp.h_addr_list[0])
        return NULL;
#endif
    return &hp->hp;
}
 
/*! \brief Produce 32 char MD5 hash of value. */
void ast_md5_hash(char *output, const char *input)
{
    struct MD5Context md5;
    unsigned char digest[16];
    char *ptr;
    int x;
 
    MD5Init(&md5);
    MD5Update(&md5, (const unsigned char *) input, strlen(input));
    MD5Final(digest, &md5);
    ptr = output;
    for (x = 0; x < 16; x++)
        ptr += sprintf(ptr, "%02hhx", digest[x]);
}
 
/*! \brief Produce 40 char SHA1 hash of value. */
void ast_sha1_hash(char *output, const char *input)
{
    struct SHA1Context sha;
    char *ptr;
    int x;
    uint8_t Message_Digest[20];
 
    SHA1Reset(&sha);
 
    SHA1Input(&sha, (const unsigned char *) input, strlen(input));
 
    SHA1Result(&sha, Message_Digest);
    ptr = output;
    for (x = 0; x < 20; x++)
        ptr += sprintf(ptr, "%02hhx", Message_Digest[x]);
}
 
/*! \brief Produce a 20 byte SHA1 hash of value. */
void ast_sha1_hash_uint(uint8_t *digest, const char *input)
{
        struct SHA1Context sha;
 
        SHA1Reset(&sha);
 
        SHA1Input(&sha, (const unsigned char *) input, strlen(input));
 
        SHA1Result(&sha, digest);
}
 
/*! \brief decode BASE64 encoded text */
int ast_base64decode(unsigned char *dst, const char *src, int max)
{
    int cnt = 0;
    unsigned int byte = 0;
    unsigned int bits = 0;
    while(*src && *src != '=' && (cnt < max)) {
        /* Shift in 6 bits of input */
        byte <<= 6;
        byte |= (b2a[(int)(*src)]) & 0x3f;
        bits += 6;
        src++;
        /* If we have at least 8 bits left over, take that character
           off the top */
        if (bits >= 8)  {
            bits -= 8;
            *dst = (byte >> bits) & 0xff;
            dst++;
            cnt++;
        }
    }
    /* Don't worry about left over bits, they're extra anyway */
    return cnt;
}
 
/*! \brief Decode BASE64 encoded text and return the string */
char *ast_base64decode_string(const char *src)
{
    size_t encoded_len;
    size_t decoded_len;
    int padding = 0;
    unsigned char *decoded_string;
 
    if (ast_strlen_zero(src)) {
        return NULL;
    }
 
    encoded_len = strlen(src);
    if (encoded_len > 2 && src[encoded_len - 1] == '=') {
        padding++;
        if (src[encoded_len - 2] == '=') {
            padding++;
        }
    }
 
    decoded_len = (encoded_len / 4 * 3) - padding;
    decoded_string = ast_malloc(decoded_len + 1);
    if (!decoded_string) {
        return NULL;
    }
 
    ast_base64decode(decoded_string, src, decoded_len);
    decoded_string[decoded_len] = '\0';
 
    return (char *)decoded_string;
}
 
/*! \brief encode text to BASE64 coding */
int ast_base64encode_full(char *dst, const unsigned char *src, int srclen, int max, int linebreaks)
{
    int cnt = 0;
    int col = 0;
    unsigned int byte = 0;
    int bits = 0;
    int cntin = 0;
    /* Reserve space for null byte at end of string */
    max--;
    while ((cntin < srclen) && (cnt < max)) {
        byte <<= 8;
        byte |= *(src++);
        bits += 8;
        cntin++;
        if ((bits == 24) && (cnt + 4 <= max)) {
            *dst++ = base64[(byte >> 18) & 0x3f];
            *dst++ = base64[(byte >> 12) & 0x3f];
            *dst++ = base64[(byte >> 6) & 0x3f];
            *dst++ = base64[byte & 0x3f];
            cnt += 4;
            col += 4;
            bits = 0;
            byte = 0;
        }
        if (linebreaks && (cnt < max) && (col == 64)) {
            *dst++ = '\n';
            cnt++;
            col = 0;
        }
    }
    if (bits && (cnt + 4 <= max)) {
        /* Add one last character for the remaining bits,
           padding the rest with 0 */
        byte <<= 24 - bits;
        *dst++ = base64[(byte >> 18) & 0x3f];
        *dst++ = base64[(byte >> 12) & 0x3f];
        if (bits == 16)
            *dst++ = base64[(byte >> 6) & 0x3f];
        else
            *dst++ = '=';
        *dst++ = '=';
        cnt += 4;
    }
    if (linebreaks && (cnt < max)) {
        *dst++ = '\n';
        cnt++;
    }
    *dst = '\0';
    return cnt;
}
 
int ast_base64encode(char *dst, const unsigned char *src, int srclen, int max)
{
    return ast_base64encode_full(dst, src, srclen, max, 0);
}
 
/*! \brief Encode to BASE64 and return encoded string */
char *ast_base64encode_string(const char *src)
{
    size_t encoded_len;
    char *encoded_string;
 
    if (ast_strlen_zero(src)) {
        return NULL;
    }
 
    encoded_len = ((strlen(src) * 4 / 3 + 3) & ~3) + 1;
    encoded_string = ast_calloc(1, encoded_len);
 
    ast_base64encode(encoded_string, (const unsigned char *)src, strlen(src), encoded_len);
 
    return encoded_string;
}
 
int ast_base64url_decode(unsigned char *dst, const char *src, int max)
{
    int cnt = 0;
    unsigned int byte = 0;
    unsigned int bits = 0;
 
    while (*src && (cnt < max)) {
        byte <<= 6;
        byte |= (b2a_url[(int)(*src)]) & 0x3f;
        bits += 6;
        src++;
        if (bits >= 8) {
            bits -= 8;
            *dst = (byte >> bits) & 0xff;
            dst++;
            cnt++;
        }
    }
    return cnt;
}
 
char *ast_base64url_decode_string(const char *src)
{
    size_t decoded_len;
    unsigned char *decoded_string;
 
    if (ast_strlen_zero(src)) {
        return NULL;
    }
 
    decoded_len = strlen(src) * 3 / 4;
    decoded_string = ast_malloc(decoded_len + 1);
    if (!decoded_string) {
        return NULL;
    }
 
    ast_base64url_decode(decoded_string, src, decoded_len);
    decoded_string[decoded_len] = '\0';
 
    return (char *)decoded_string;
}
 
int ast_base64url_encode_full(char *dst, const unsigned char *src, int srclen, int max, int linebreaks)
{
    int cnt = 0;
    int col = 0;
    unsigned int byte = 0;
    int bits = 0;
    int cntin = 0;
 
    max--;
    while ((cntin < srclen) && (cnt < max)) {
        byte <<= 8;
        byte |= *(src++);
        bits += 8;
        cntin++;
        if ((bits == 24) && (cnt + 4 <= max)) {
            *dst++ = base64url[(byte >> 18) & 0x3f];
            *dst++ = base64url[(byte >> 12) & 0x3f];
            *dst++ = base64url[(byte >> 6) & 0x3f];
            *dst++ = base64url[(byte) & 0x3f];
            cnt += 4;
            col += 4;
            bits = 0;
            byte = 0;
        }
        if (linebreaks && (cnt < max) && (col == 64)) {
            *dst++ = '\n';
            cnt++;
            col = 0;
        }
    }
    if (bits && (cnt + 4 <= max)) {
        byte <<= 24 - bits;
        *dst++ = base64url[(byte >> 18) & 0x3f];
        *dst++ = base64url[(byte >> 12) & 0x3f];
        if (bits == 16) {
            *dst++ = base64url[(byte >> 6) & 0x3f];
        }
        cnt += 4;
    }
    if (linebreaks && (cnt < max)) {
        *dst++ = '\n';
        cnt++;
    }
    *dst = '\0';
    return cnt;
}
 
int ast_base64url_encode(char *dst, const unsigned char *src, int srclen, int max)
{
    return ast_base64url_encode_full(dst, src, srclen, max, 0);
}
 
char *ast_base64url_encode_string(const char *src)
{
    size_t encoded_len;
    char *encoded_string;
 
    if (ast_strlen_zero(src)) {
        return NULL;
    }
 
    encoded_len = ((strlen(src) * 4 / 3 + 3) & ~3) + 1;
    encoded_string = ast_malloc(encoded_len);
 
    ast_base64url_encode(encoded_string, (const unsigned char *)src, strlen(src), encoded_len);
 
    return encoded_string;
}
 
static void base64_init(void)
{
    int x;
    memset(b2a, -1, sizeof(b2a));
    memset(b2a_url, -1, sizeof(b2a_url));
    /* Initialize base-64 Conversion table */
    for (x = 0; x < 26; x++) {
        /* A-Z */
        base64[x] = 'A' + x;
        base64url[x] = 'A' + x;
        b2a['A' + x] = x;
        b2a_url['A' + x] = x;
        /* a-z */
        base64[x + 26] = 'a' + x;
        base64url[x + 26] = 'a' + x;
        b2a['a' + x] = x + 26;
        b2a_url['a' + x] = x + 26;
        /* 0-9 */
        if (x < 10) {
            base64[x + 52] = '0' + x;
            base64url[x + 52] = '0' + x;
            b2a['0' + x] = x + 52;
            b2a_url['0' + x] = x + 52;
        }
    }
    base64[62] = '+';
    base64[63] = '/';
    base64url[62] = '-';
    base64url[63] = '_';
    b2a[(int)'+'] = 62;
    b2a[(int)'/'] = 63;
    b2a_url[(int)'-'] = 62;
    b2a_url[(int)'_'] = 63;
}
 
#define BASELINELEN    72  /*!< Line length for Base 64 encoded messages */
#define BASEMAXINLINE  256 /*!< Buffer size for Base 64 attachment encoding */
 
/*! \brief Structure used for base64 encoding */
struct baseio {
    int iocp;
    int iolen;
    int linelength;
    int ateof;
    unsigned char iobuf[BASEMAXINLINE];
};
 
/*!
 * \brief utility used by inchar(), for base_encode()
 */
static int inbuf(struct baseio *bio, FILE *fi)
{
    int l;
 
    if (bio->ateof) {
        return 0;
    }
 
    if ((l = fread(bio->iobuf, 1, BASEMAXINLINE, fi)) != BASEMAXINLINE) {
        bio->ateof = 1;
        if (l == 0) {
            /* Assume EOF */
            return 0;
        }
    }
 
    bio->iolen = l;
    bio->iocp = 0;
 
    return 1;
}
 
/*!
 * \brief utility used by base_encode()
 */
static int inchar(struct baseio *bio, FILE *fi)
{
    if (bio->iocp >= bio->iolen) {
        if (!inbuf(bio, fi)) {
            return EOF;
        }
    }
 
    return bio->iobuf[bio->iocp++];
}
 
/*!
 * \brief utility used by base_encode()
 */
static int ochar(struct baseio *bio, int c, FILE *so, const char *endl)
{
    if (bio->linelength >= BASELINELEN) {
        if (fputs(endl, so) == EOF) {
            return -1;
        }
 
        bio->linelength = 0;
    }
 
    if (putc(((unsigned char) c), so) == EOF) {
        return -1;
    }
 
    bio->linelength++;
 
    return 1;
}
 
int ast_base64_encode_file(FILE *inputfile, FILE *outputfile, const char *endl)
{
    static const unsigned char dtable[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K',
        'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
        'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0',
        '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
    int i, hiteof = 0;
    struct baseio bio;
 
    memset(&bio, 0, sizeof(bio));
    bio.iocp = BASEMAXINLINE;
 
    while (!hiteof){
        unsigned char igroup[3], ogroup[4];
        int c, n;
 
        memset(igroup, 0, sizeof(igroup));
 
        for (n = 0; n < 3; n++) {
            if ((c = inchar(&bio, inputfile)) == EOF) {
                hiteof = 1;
                break;
            }
 
            igroup[n] = (unsigned char) c;
        }
 
        if (n > 0) {
            ogroup[0]= dtable[igroup[0] >> 2];
            ogroup[1]= dtable[((igroup[0] & 3) << 4) | (igroup[1] >> 4)];
            ogroup[2]= dtable[((igroup[1] & 0xF) << 2) | (igroup[2] >> 6)];
            ogroup[3]= dtable[igroup[2] & 0x3F];
 
            if (n < 3) {
                ogroup[3] = '=';
 
                if (n < 2) {
                    ogroup[2] = '=';
                }
            }
 
            for (i = 0; i < 4; i++) {
                ochar(&bio, ogroup[i], outputfile, endl);
            }
        }
    }
 
    if (fputs(endl, outputfile) == EOF) {
        return 0;
    }
 
    return 1;
}
 
int ast_base64_encode_file_path(const char *filename, FILE *outputfile, const char *endl)
{
    FILE *fi;
    int res;
 
    if (!(fi = fopen(filename, "rb"))) {
        ast_log(AST_LOG_WARNING, "Failed to open file: %s: %s\n", filename, strerror(errno));
        return -1;
    }
 
    res = ast_base64_encode_file(fi, outputfile, endl);
 
    fclose(fi);
 
    return res;
}
 
const struct ast_flags ast_uri_http = {AST_URI_UNRESERVED};
const struct ast_flags ast_uri_http_legacy = {AST_URI_LEGACY_SPACE | AST_URI_UNRESERVED};
const struct ast_flags ast_uri_sip_user = {AST_URI_UNRESERVED | AST_URI_SIP_USER_UNRESERVED};
 
char *ast_uri_encode(const char *string, char *outbuf, int buflen, struct ast_flags spec)
{
    const char *ptr  = string;  /* Start with the string */
    char *out = outbuf;
    const char *mark = "-_.!~*'()"; /* no encode set, RFC 2396 section 2.3, RFC 3261 sec 25 */
    const char *user_unreserved = "&=+$,;?/"; /* user-unreserved set, RFC 3261 sec 25 */
 
    while (*ptr && out - outbuf < buflen - 1) {
        if (ast_test_flag(&spec, AST_URI_LEGACY_SPACE) && *ptr == ' ') {
            /* for legacy encoding, encode spaces as '+' */
            *out = '+';
            out++;
        } else if (!(ast_test_flag(&spec, AST_URI_MARK)
                && strchr(mark, *ptr))
            && !(ast_test_flag(&spec, AST_URI_ALPHANUM)
                && ((*ptr >= '0' && *ptr <= '9')
                || (*ptr >= 'A' && *ptr <= 'Z')
                || (*ptr >= 'a' && *ptr <= 'z')))
            && !(ast_test_flag(&spec, AST_URI_SIP_USER_UNRESERVED)
                && strchr(user_unreserved, *ptr))) {
 
            if (out - outbuf >= buflen - 3) {
                break;
            }
            out += sprintf(out, "%%%02hhX", (unsigned char) *ptr);
        } else {
            *out = *ptr;    /* Continue copying the string */
            out++;
        }
        ptr++;
    }
 
    if (buflen) {
        *out = '\0';
    }
 
    return outbuf;
}
 
void ast_uri_decode(char *s, struct ast_flags spec)
{
    char *o;
    unsigned int tmp;
 
    for (o = s; *s; s++, o++) {
        if (ast_test_flag(&spec, AST_URI_LEGACY_SPACE) && *s == '+') {
            /* legacy mode, decode '+' as space */
            *o = ' ';
        } else if (*s == '%' && s[1] != '\0' && s[2] != '\0' && sscanf(s + 1, "%2x", &tmp) == 1) {
            /* have '%', two chars and correct parsing */
            *o = tmp;
            s += 2; /* Will be incremented once more when we break out */
        } else /* all other cases, just copy */
            *o = *s;
    }
    *o = '\0';
}
 
int ast_uri_verify_encoded(const char *string)
{
    const char *ptr = string;
    size_t length;
    char *endl;
 
    if (!string) {
        return 0;
    }
 
    length = strlen(string);
    endl = (char *)string + length;
 
    while (*ptr) {
        if (*ptr == '%') {
            unsigned int tmp;
            /* Make sure there are at least 2 characters left to decode */
            if (ptr + 2 >= endl) {
                return 0;
            }
            /* Try to parse the next two characters as hex */
            if (sscanf(ptr + 1, "%2x", &tmp) != 1) {
                return 0;
            }
            /* All good, move past the '%' and the two hex digits */
            ptr += 3;
        } else if (!isalnum((unsigned char ) *ptr) && !strchr("-_.+", *ptr)) {
            return 0;
        } else {
            ptr++;
        }
    }
 
    return 1; /* all characters are valid */
}
 
char *ast_escape_quoted(const char *string, char *outbuf, int buflen)
{
    const char *ptr  = string;
    char *out = outbuf;
    char *allow = "\t\v !"; /* allow LWS (minus \r and \n) and "!" */
 
    while (*ptr && out - outbuf < buflen - 1) {
        if (!(strchr(allow, *ptr))
            && !(*ptr >= '#' && *ptr <= '[') /* %x23 - %x5b */
            && !(*ptr >= ']' && *ptr <= '~') /* %x5d - %x7e */
            && !((unsigned char) *ptr > 0x7f)) {             /* UTF8-nonascii */
 
            if (out - outbuf >= buflen - 2) {
                break;
            }
            out += sprintf(out, "\\%c", (unsigned char) *ptr);
        } else {
            *out = *ptr;
            out++;
        }
        ptr++;
    }
 
    if (buflen) {
        *out = '\0';
    }
 
    return outbuf;
}
 
char *ast_escape_semicolons(const char *string, char *outbuf, int buflen)
{
    const char *ptr = string;
    char *out = outbuf;
 
    if (string == NULL || outbuf == NULL) {
        ast_assert(string != NULL && outbuf != NULL);
        return NULL;
    }
 
    while (*ptr && out - outbuf < buflen - 1) {
        if (*ptr == ';') {
            if (out - outbuf >= buflen - 2) {
                break;
            }
            strcpy(out, "\\;");
            out += 2;
        } else {
            *out = *ptr;
            out++;
        }
        ptr++;
    }
 
    if (buflen) {
        *out = '\0';
    }
 
    return outbuf;
}
 
void ast_unescape_quoted(char *quote_str)
{
    int esc_pos;
    int unesc_pos;
    int quote_str_len = strlen(quote_str);
 
    for (esc_pos = 0, unesc_pos = 0;
        esc_pos < quote_str_len;
        esc_pos++, unesc_pos++) {
        if (quote_str[esc_pos] == '\\') {
            /* at least one more char and current is \\ */
            esc_pos++;
            if (esc_pos >= quote_str_len) {
                break;
            }
        }
 
        quote_str[unesc_pos] = quote_str[esc_pos];
    }
    quote_str[unesc_pos] = '\0';
}
 
int ast_xml_escape(const char *string, char * const outbuf, const size_t buflen)
{
    char *dst = outbuf;
    char *end = outbuf + buflen - 1; /* save one for the null terminator */
 
    /* Handle the case for the empty output buffer */
    if (buflen == 0) {
        return -1;
    }
 
    /* Escaping rules from http://www.w3.org/TR/REC-xml/#syntax */
    /* This also prevents partial entities at the end of a string */
    while (*string && dst < end) {
        const char *entity = NULL;
        int len = 0;
 
        switch (*string) {
        case '<':
            entity = "&lt;";
            len = 4;
            break;
        case '&':
            entity = "&amp;";
            len = 5;
            break;
        case '>':
            /* necessary if ]]> is in the string; easier to escape them all */
            entity = "&gt;";
            len = 4;
            break;
        case '\'':
            /* necessary in single-quoted strings; easier to escape them all */
            entity = "&apos;";
            len = 6;
            break;
        case '"':
            /* necessary in double-quoted strings; easier to escape them all */
            entity = "&quot;";
            len = 6;
            break;
        default:
            *dst++ = *string++;
            break;
        }
 
        if (entity) {
            ast_assert(len == strlen(entity));
            if (end - dst < len) {
                /* no room for the entity; stop */
                break;
            }
            /* just checked for length; strcpy is fine */
            strcpy(dst, entity);
            dst += len;
            ++string;
        }
    }
    /* Write null terminator */
    *dst = '\0';
    /* If any chars are left in string, return failure */
    return *string == '\0' ? 0 : -1;
}
 
/*! \brief  ast_inet_ntoa: Recursive thread safe replacement of inet_ntoa */
const char *ast_inet_ntoa(struct in_addr ia)
{
    char *buf;
 
    if (!(buf = ast_threadstorage_get(&inet_ntoa_buf, INET_ADDRSTRLEN)))
        return "";
 
    return inet_ntop(AF_INET, &ia, buf, INET_ADDRSTRLEN);
}
 
static int dev_urandom_fd = -1;
 
#ifndef __linux__
#undef pthread_create /* For ast_pthread_create function only */
#endif /* !__linux__ */
 
#ifdef DEBUG_THREADS
 
#if !defined(LOW_MEMORY)
/*! \brief A reasonable maximum number of locks a thread would be holding ... */
#define AST_MAX_LOCKS 64
 
/* Allow direct use of pthread_mutex_t and friends */
#undef pthread_mutex_t
#undef pthread_mutex_lock
#undef pthread_mutex_unlock
#undef pthread_mutex_init
#undef pthread_mutex_destroy
 
/*!
 * \brief Keep track of which locks a thread holds
 *
 * There is an instance of this struct for every active thread
 */
struct thr_lock_info {
    /*! The thread's ID */
    pthread_t thread_id;
    /*! The thread name which includes where the thread was started */
    const char *thread_name;
    /*! This is the actual container of info for what locks this thread holds */
    struct {
        const char *file;
        const char *func;
        const char *lock_name;
        void *lock_addr;
        int times_locked;
        int times_lock_attempted;
        struct timeval last_locked;
        struct timeval last_unlocked;
        int line_num;
        enum ast_lock_type type;
        /*! This thread is waiting on this lock */
        int pending:2;
        /*! A condition has suspended this lock */
        int suspended:1;
#ifdef HAVE_BKTR
        struct ast_bt *backtrace;
#endif
    } locks[AST_MAX_LOCKS];
    /*! This is the number of locks currently held by this thread.
     *  The index (num_locks - 1) has the info on the last one in the
     *  locks member */
    unsigned int num_locks;
    /*! The LWP id (which GDB prints) */
    int lwp;
    /*! Protects the contents of the locks member
     * Intentionally not ast_mutex_t */
    pthread_mutex_t lock;
    AST_LIST_ENTRY(thr_lock_info) entry;
};
 
/*!
 * \brief Locked when accessing the lock_infos list
 */
AST_MUTEX_DEFINE_STATIC(lock_infos_lock);
/*!
 * \brief A list of each thread's lock info
 */
static AST_LIST_HEAD_NOLOCK_STATIC(lock_infos, thr_lock_info);
 
/*!
 * \brief Destroy a thread's lock info
 *
 * This gets called automatically when the thread stops
 */
static void lock_info_destroy(void *data)
{
    struct thr_lock_info *lock_info = data;
    int i;
 
    pthread_mutex_lock(&lock_infos_lock.mutex);
    AST_LIST_REMOVE(&lock_infos, lock_info, entry);
    pthread_mutex_unlock(&lock_infos_lock.mutex);
 
 
    for (i = 0; i < lock_info->num_locks; i++) {
        if (lock_info->locks[i].pending == -1) {
            /* This just means that the last lock this thread went for was by
             * using trylock, and it failed.  This is fine. */
            break;
        }
 
        ast_log(LOG_ERROR,
            "Thread '%s' still has a lock! - '%s' (%p) from '%s' in %s:%d!\n",
            lock_info->thread_name,
            lock_info->locks[i].lock_name,
            lock_info->locks[i].lock_addr,
            lock_info->locks[i].func,
            lock_info->locks[i].file,
            lock_info->locks[i].line_num
        );
    }
 
    pthread_mutex_destroy(&lock_info->lock);
    if (lock_info->thread_name) {
        ast_free((void *) lock_info->thread_name);
    }
    ast_free(lock_info);
}
 
/*!
 * \brief The thread storage key for per-thread lock info
 */
AST_THREADSTORAGE_CUSTOM(thread_lock_info, NULL, lock_info_destroy);
#endif /* ! LOW_MEMORY */
 
void ast_store_lock_info(enum ast_lock_type type, const char *filename,
    int line_num, const char *func, const char *lock_name, void *lock_addr, struct ast_bt *bt)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    int i;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return;
 
    pthread_mutex_lock(&lock_info->lock);
 
    for (i = 0; i < lock_info->num_locks; i++) {
        if (lock_info->locks[i].lock_addr == lock_addr) {
            lock_info->locks[i].times_locked++;
            lock_info->locks[i].times_lock_attempted++;
            lock_info->locks[i].last_locked = ast_tvnow();
#ifdef HAVE_BKTR
            lock_info->locks[i].backtrace = bt;
#endif
            pthread_mutex_unlock(&lock_info->lock);
            return;
        }
    }
 
    if (lock_info->num_locks == AST_MAX_LOCKS) {
        /* Can't use ast_log here, because it will cause infinite recursion */
        fprintf(stderr, "XXX ERROR XXX A thread holds more locks than '%d'."
            "  Increase AST_MAX_LOCKS!\n", AST_MAX_LOCKS);
        pthread_mutex_unlock(&lock_info->lock);
        return;
    }
 
    if (i && lock_info->locks[i - 1].pending == -1) {
        /* The last lock on the list was one that this thread tried to lock but
         * failed at doing so.  It has now moved on to something else, so remove
         * the old lock from the list. */
        i--;
        lock_info->num_locks--;
        memset(&lock_info->locks[i], 0, sizeof(lock_info->locks[0]));
    }
 
    lock_info->locks[i].file = filename;
    lock_info->locks[i].line_num = line_num;
    lock_info->locks[i].func = func;
    lock_info->locks[i].lock_name = lock_name;
    lock_info->locks[i].lock_addr = lock_addr;
    lock_info->locks[i].times_locked = 1;
    lock_info->locks[i].times_lock_attempted = 1;
    lock_info->locks[i].last_locked = ast_tvnow();
    lock_info->locks[i].type = type;
    lock_info->locks[i].pending = 1;
#ifdef HAVE_BKTR
    lock_info->locks[i].backtrace = bt;
#endif
    lock_info->num_locks++;
 
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
void ast_mark_lock_acquired(void *lock_addr)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return;
 
    pthread_mutex_lock(&lock_info->lock);
    if (lock_info->locks[lock_info->num_locks - 1].lock_addr == lock_addr) {
        lock_info->locks[lock_info->num_locks - 1].pending = 0;
    }
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
void ast_mark_lock_failed(void *lock_addr)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return;
 
    pthread_mutex_lock(&lock_info->lock);
    if (lock_info->locks[lock_info->num_locks - 1].lock_addr == lock_addr) {
        lock_info->locks[lock_info->num_locks - 1].pending = -1;
        lock_info->locks[lock_info->num_locks - 1].times_locked--;
        lock_info->locks[lock_info->num_locks - 1].last_unlocked = ast_tvnow();
    }
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, int *lineno, char *func, size_t func_size, char *mutex_name, size_t mutex_name_size)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    int i = 0;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return -1;
 
    pthread_mutex_lock(&lock_info->lock);
 
    for (i = lock_info->num_locks - 1; i >= 0; i--) {
        if (lock_info->locks[i].lock_addr == lock_addr)
            break;
    }
 
    if (i == -1) {
        /* Lock not found :( */
        pthread_mutex_unlock(&lock_info->lock);
        return -1;
    }
 
    ast_copy_string(filename, lock_info->locks[i].file, filename_size);
    *lineno = lock_info->locks[i].line_num;
    ast_copy_string(func, lock_info->locks[i].func, func_size);
    ast_copy_string(mutex_name, lock_info->locks[i].lock_name, mutex_name_size);
 
    pthread_mutex_unlock(&lock_info->lock);
 
    return 0;
#else /* if defined(LOW_MEMORY) */
    return -1;
#endif
}
 
void ast_suspend_lock_info(void *lock_addr)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    int i = 0;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info)))) {
        return;
    }
 
    pthread_mutex_lock(&lock_info->lock);
 
    for (i = lock_info->num_locks - 1; i >= 0; i--) {
        if (lock_info->locks[i].lock_addr == lock_addr)
            break;
    }
 
    if (i == -1) {
        /* Lock not found :( */
        pthread_mutex_unlock(&lock_info->lock);
        return;
    }
 
    lock_info->locks[i].suspended = 1;
 
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
void ast_restore_lock_info(void *lock_addr)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    int i = 0;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return;
 
    pthread_mutex_lock(&lock_info->lock);
 
    for (i = lock_info->num_locks - 1; i >= 0; i--) {
        if (lock_info->locks[i].lock_addr == lock_addr)
            break;
    }
 
    if (i == -1) {
        /* Lock not found :( */
        pthread_mutex_unlock(&lock_info->lock);
        return;
    }
 
    lock_info->locks[i].suspended = 0;
 
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
 
void ast_remove_lock_info(void *lock_addr, struct ast_bt *bt)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    int i = 0;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return;
 
    pthread_mutex_lock(&lock_info->lock);
 
    for (i = lock_info->num_locks - 1; i >= 0; i--) {
        if (lock_info->locks[i].lock_addr == lock_addr)
            break;
    }
 
    if (i == -1) {
        /* Lock not found :( */
        pthread_mutex_unlock(&lock_info->lock);
        return;
    }
 
    if (lock_info->locks[i].times_locked > 1) {
        lock_info->locks[i].times_locked--;
        lock_info->locks[i].last_unlocked = ast_tvnow();
#ifdef HAVE_BKTR
        lock_info->locks[i].backtrace = bt;
#endif
        pthread_mutex_unlock(&lock_info->lock);
        return;
    }
 
    if (i < lock_info->num_locks - 1) {
        /* Not the last one ... *should* be rare! */
        memmove(&lock_info->locks[i], &lock_info->locks[i + 1],
            (lock_info->num_locks - (i + 1)) * sizeof(lock_info->locks[0]));
    }
 
    lock_info->num_locks--;
 
    pthread_mutex_unlock(&lock_info->lock);
#endif /* ! LOW_MEMORY */
}
 
#if !defined(LOW_MEMORY)
static const char *locktype2str(enum ast_lock_type type)
{
    switch (type) {
    case AST_MUTEX:
        return "MUTEX";
    case AST_RDLOCK:
        return "RDLOCK";
    case AST_WRLOCK:
        return "WRLOCK";
    }
 
    return "UNKNOWN";
}
 
#ifdef HAVE_BKTR
static void append_backtrace_information(struct ast_str **str, struct ast_bt *bt)
{
    struct ast_vector_string *symbols;
    int num_frames;
 
    if (!bt) {
        ast_str_append(str, 0, "\tNo backtrace to print\n");
        return;
    }
 
    /* store frame count locally to avoid the memory corruption that
     * sometimes happens on virtualized CentOS 6.x systems */
    num_frames = bt->num_frames;
    if ((symbols = ast_bt_get_symbols(bt->addresses, num_frames))) {
        int frame_iterator;
 
        for (frame_iterator = 1; frame_iterator < AST_VECTOR_SIZE(symbols); ++frame_iterator) {
            ast_str_append(str, 0, "\t%s\n", AST_VECTOR_GET(symbols, frame_iterator));
        }
 
        ast_bt_free_symbols(symbols);
    } else {
        ast_str_append(str, 0, "\tCouldn't retrieve backtrace symbols\n");
    }
}
#endif
 
static void append_lock_information(struct ast_str **str, struct thr_lock_info *lock_info, int i)
{
    int j;
    ast_mutex_t *lock;
    struct ast_lock_track *lt;
    struct timeval held_for;
    struct timeval now = ast_tvnow();
    char lock_time[32], unlock_time[32], held_time[32];
 
    held_for = ast_tvsub(now, lock_info->locks[i].last_locked);
    /* format time duration strings */
    ast_format_duration_hh_mm_ss(lock_info->locks[i].last_locked.tv_sec,
                                    lock_time, sizeof(lock_time));
    ast_format_duration_hh_mm_ss(lock_info->locks[i].last_unlocked.tv_sec,
                                    unlock_time, sizeof(unlock_time));
    ast_format_duration_hh_mm_ss(held_for.tv_sec, held_time, sizeof(held_time));
 
    ast_str_append(str, 0, "=== ---> %sLock #%d (%s): %s %d %s %s %p\n"
                        "===      %s.%06ld, %s.%06ld, %s.%06ld (%d, %d%s)\n",
                   lock_info->locks[i].pending > 0 ? "Waiting for " :
                   lock_info->locks[i].pending < 0 ? "Tried and failed to get " : "", i,
                   lock_info->locks[i].file,
                   locktype2str(lock_info->locks[i].type),
                   lock_info->locks[i].line_num,
                   lock_info->locks[i].func,
                   lock_info->locks[i].lock_name,
                   lock_info->locks[i].lock_addr,
                   lock_time,
                   lock_info->locks[i].last_locked.tv_usec,
                   unlock_time,
                   lock_info->locks[i].last_unlocked.tv_usec,
                   held_time,
                   held_for.tv_usec,
                   lock_info->locks[i].times_locked,
                   lock_info->locks[i].times_lock_attempted,
                   lock_info->locks[i].suspended ? " - suspended" : "");
#ifdef HAVE_BKTR
    append_backtrace_information(str, lock_info->locks[i].backtrace);
#endif
 
    if (!lock_info->locks[i].pending || lock_info->locks[i].pending == -1)
        return;
 
    /* We only have further details for mutexes right now */
    if (lock_info->locks[i].type != AST_MUTEX)
        return;
 
    lock = lock_info->locks[i].lock_addr;
    lt = lock->track;
    ast_reentrancy_lock(lt);
    for (j = 0; *str && j < lt->reentrancy; j++) {
        ast_str_append(str, 0, "=== --- ---> Locked Here: %s line %d (%s)\n",
                       lt->file[j], lt->lineno[j], lt->func[j]);
    }
    ast_reentrancy_unlock(lt);
}
#endif /* ! LOW_MEMORY */
 
/*! This function can help you find highly temporal locks; locks that happen for a
    short time, but at unexpected times, usually at times that create a deadlock,
    Why is this thing locked right then? Who is locking it? Who am I fighting
    with for this lock?
 
    To answer such questions, just call this routine before you would normally try
    to acquire a lock. It doesn't do anything if the lock is not acquired. If the
    lock is taken, it will publish a line or two to the console via ast_log().
 
    Sometimes, the lock message is pretty uninformative. For instance, you might
    find that the lock is being acquired deep within the astobj2 code; this tells
    you little about higher level routines that call the astobj2 routines.
    But, using gdb, you can set a break at the ast_log below, and for that
    breakpoint, you can set the commands:
      where
      cont
    which will give a stack trace and continue. -- that aught to do the job!
 
*/
void ast_log_show_lock(void *this_lock_addr)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    struct ast_str *str;
 
    if (!(str = ast_str_create(4096))) {
        ast_log(LOG_NOTICE,"Could not create str\n");
        return;
    }
 
 
    pthread_mutex_lock(&lock_infos_lock.mutex);
    AST_LIST_TRAVERSE(&lock_infos, lock_info, entry) {
        int i;
        pthread_mutex_lock(&lock_info->lock);
        for (i = 0; str && i < lock_info->num_locks; i++) {
            /* ONLY show info about this particular lock, if
               it's acquired... */
            if (lock_info->locks[i].lock_addr == this_lock_addr) {
                append_lock_information(&str, lock_info, i);
                ast_log(LOG_NOTICE, "%s", ast_str_buffer(str));
                break;
            }
        }
        pthread_mutex_unlock(&lock_info->lock);
    }
    pthread_mutex_unlock(&lock_infos_lock.mutex);
    ast_free(str);
#endif /* ! LOW_MEMORY */
}
 
 
struct ast_str *ast_dump_locks(void)
{
#if !defined(LOW_MEMORY)
    struct thr_lock_info *lock_info;
    struct ast_str *str;
    char print_time[32];
    struct timeval now = ast_tvnow();
 
    if (!(str = ast_str_create(4096))) {
        return NULL;
    }
 
    ast_format_duration_hh_mm_ss(now.tv_sec, print_time, sizeof(print_time));
 
    ast_str_append(&str, 0, "\n"
                   "=======================================================================\n"
                   "=== %s\n"
                   "=== Currently Held Locks at Time: %s.%06ld =================\n"
                   "=======================================================================\n"
                   "===\n"
                   "=== <pending> <lock#> (<file>): <lock type> <line num> <function> <lock name> <lock addr>\n"
                   "=== <locked at>, <failed at>, <held for> (attempts, times locked)\n"
                   "===\n", ast_get_version(), print_time, now.tv_usec);
    if (!str) {
        return NULL;
    }
 
    pthread_mutex_lock(&lock_infos_lock.mutex);
    AST_LIST_TRAVERSE(&lock_infos, lock_info, entry) {
        int i;
        int header_printed = 0;
        pthread_mutex_lock(&lock_info->lock);
        for (i = 0; str && i < lock_info->num_locks; i++) {
            /* Don't show suspended locks */
            if (lock_info->locks[i].suspended) {
                continue;
            }
 
            if (!header_printed) {
                if (lock_info->lwp != -1) {
                    ast_str_append(&str, 0, "=== Thread ID: 0x%lx LWP:%d (%s)\n",
                        (long unsigned) lock_info->thread_id, lock_info->lwp, lock_info->thread_name);
                } else {
                    ast_str_append(&str, 0, "=== Thread ID: 0x%lx (%s)\n",
                        (long unsigned) lock_info->thread_id, lock_info->thread_name);
                }
                header_printed = 1;
            }
 
            append_lock_information(&str, lock_info, i);
        }
        pthread_mutex_unlock(&lock_info->lock);
        if (!str) {
            break;
        }
        if (header_printed) {
            ast_str_append(&str, 0, "=== -------------------------------------------------------------------\n"
                "===\n");
        }
        if (!str) {
            break;
        }
    }
    pthread_mutex_unlock(&lock_infos_lock.mutex);
 
    if (!str) {
        return NULL;
    }
 
    ast_str_append(&str, 0, "=======================================================================\n"
                   "\n");
 
    return str;
#else /* if defined(LOW_MEMORY) */
    return NULL;
#endif
}
 
#if !defined(LOW_MEMORY)
static char *handle_show_locks(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct ast_str *str;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "core show locks";
        e->usage =
            "Usage: core show locks\n"
            "       This command is for lock debugging.  It prints out which locks\n"
            "are owned by each active thread.\n";
        ast_cli_allow_at_shutdown(e);
        return NULL;
 
    case CLI_GENERATE:
        return NULL;
    }
 
    str = ast_dump_locks();
    if (!str) {
        return CLI_FAILURE;
    }
 
    ast_cli(a->fd, "%s", ast_str_buffer(str));
 
    ast_free(str);
 
    return CLI_SUCCESS;
}
 
static struct ast_cli_entry utils_cli[] = {
    AST_CLI_DEFINE(handle_show_locks, "Show which locks are held by which thread"),
};
#endif /* ! LOW_MEMORY */
#endif /* DEBUG_THREADS */
 
#if !defined(LOW_MEMORY)
/*
 * support for 'show threads'. The start routine is wrapped by
 * dummy_start(), so that ast_register_thread() and
 * ast_unregister_thread() know the thread identifier.
 */
struct thr_arg {
    void *(*start_routine)(void *);
    void *data;
    char *name;
};
 
/*
 * on OS/X, pthread_cleanup_push() and pthread_cleanup_pop()
 * are odd macros which start and end a block, so they _must_ be
 * used in pairs (the latter with a '1' argument to call the
 * handler on exit.
 * On BSD we don't need this, but we keep it for compatibility.
 */
static void *dummy_start(void *data)
{
    void *ret;
    struct thr_arg a = *((struct thr_arg *) data);  /* make a local copy */
#ifdef DEBUG_THREADS
    struct thr_lock_info *lock_info;
    pthread_mutexattr_t mutex_attr;
 
    if (!(lock_info = ast_threadstorage_get(&thread_lock_info, sizeof(*lock_info))))
        return NULL;
 
    lock_info->thread_id = pthread_self();
    lock_info->lwp = ast_get_tid();
    lock_info->thread_name = ast_strdup(a.name);
 
    pthread_mutexattr_init(&mutex_attr);
    pthread_mutexattr_settype(&mutex_attr, AST_MUTEX_KIND);
    pthread_mutex_init(&lock_info->lock, &mutex_attr);
    pthread_mutexattr_destroy(&mutex_attr);
 
    pthread_mutex_lock(&lock_infos_lock.mutex); /* Intentionally not the wrapper */
    AST_LIST_INSERT_TAIL(&lock_infos, lock_info, entry);
    pthread_mutex_unlock(&lock_infos_lock.mutex); /* Intentionally not the wrapper */
#endif /* DEBUG_THREADS */
 
    /* note that even though data->name is a pointer to allocated memory,
       we are not freeing it here because ast_register_thread is going to
       keep a copy of the pointer and then ast_unregister_thread will
       free the memory
    */
    ast_free(data);
    ast_register_thread(a.name);
    pthread_cleanup_push(ast_unregister_thread, (void *) pthread_self());
 
    ret = a.start_routine(a.data);
 
    pthread_cleanup_pop(1);
 
    return ret;
}
 
#endif /* !LOW_MEMORY */
 
int ast_background_stacksize(void)
{
#if !defined(LOW_MEMORY)
    return AST_STACKSIZE;
#else
    return AST_STACKSIZE_LOW;
#endif
}
 
int ast_pthread_create_stack(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine)(void *),
                 void *data, size_t stacksize, const char *file, const char *caller,
                 int line, const char *start_fn)
{
#if !defined(LOW_MEMORY)
    struct thr_arg *a;
#endif
 
    if (!attr) {
        attr = ast_alloca(sizeof(*attr));
        pthread_attr_init(attr);
    }
 
#if defined(__linux__) || defined(__FreeBSD__)
    /* On Linux and FreeBSD , pthread_attr_init() defaults to PTHREAD_EXPLICIT_SCHED,
       which is kind of useless. Change this here to
       PTHREAD_INHERIT_SCHED; that way the -p option to set realtime
       priority will propagate down to new threads by default.
       This does mean that callers cannot set a different priority using
       PTHREAD_EXPLICIT_SCHED in the attr argument; instead they must set
       the priority afterwards with pthread_setschedparam(). */
    if ((errno = pthread_attr_setinheritsched(attr, PTHREAD_INHERIT_SCHED)))
        ast_log(LOG_WARNING, "pthread_attr_setinheritsched: %s\n", strerror(errno));
#endif
 
    if (!stacksize)
        stacksize = AST_STACKSIZE;
 
    if ((errno = pthread_attr_setstacksize(attr, stacksize ? stacksize : AST_STACKSIZE)))
        ast_log(LOG_WARNING, "pthread_attr_setstacksize: %s\n", strerror(errno));
 
#if !defined(LOW_MEMORY)
    if ((a = ast_malloc(sizeof(*a)))) {
        a->start_routine = start_routine;
        a->data = data;
        start_routine = dummy_start;
        if (ast_asprintf(&a->name, "%-20s started at [%5d] %s %s()",
                 start_fn, line, file, caller) < 0) {
            a->name = NULL;
        }
        data = a;
    }
#endif /* !LOW_MEMORY */
 
    return pthread_create(thread, attr, start_routine, data); /* We're in ast_pthread_create, so it's okay */
}
 
 
int ast_pthread_create_detached_stack(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine)(void *),
                 void *data, size_t stacksize, const char *file, const char *caller,
                 int line, const char *start_fn)
{
    unsigned char attr_destroy = 0;
    int res;
 
    if (!attr) {
        attr = ast_alloca(sizeof(*attr));
        pthread_attr_init(attr);
        attr_destroy = 1;
    }
 
    if ((errno = pthread_attr_setdetachstate(attr, PTHREAD_CREATE_DETACHED)))
        ast_log(LOG_WARNING, "pthread_attr_setdetachstate: %s\n", strerror(errno));
 
    res = ast_pthread_create_stack(thread, attr, start_routine, data,
                                   stacksize, file, caller, line, start_fn);
 
    if (attr_destroy)
        pthread_attr_destroy(attr);
 
    return res;
}
 
int ast_wait_for_input(int fd, int ms)
{
    struct pollfd pfd[1];
 
    memset(pfd, 0, sizeof(pfd));
    pfd[0].fd = fd;
    pfd[0].events = POLLIN | POLLPRI;
    return ast_poll(pfd, 1, ms);
}
 
int ast_wait_for_output(int fd, int ms)
{
    struct pollfd pfd[1];
 
    memset(pfd, 0, sizeof(pfd));
    pfd[0].fd = fd;
    pfd[0].events = POLLOUT;
    return ast_poll(pfd, 1, ms);
}
 
static int wait_for_output(int fd, int timeoutms)
{
    struct pollfd pfd = {
        .fd = fd,
        .events = POLLOUT,
    };
    int res;
    struct timeval start = ast_tvnow();
    int elapsed = 0;
 
    /* poll() until the fd is writable without blocking */
    while ((res = ast_poll(&pfd, 1, timeoutms - elapsed)) <= 0) {
        if (res == 0) {
            /* timed out. */
#ifndef STANDALONE
            ast_debug(1, "Timed out trying to write\n");
#endif
            return -1;
        } else if (res == -1) {
            /* poll() returned an error, check to see if it was fatal */
 
            if (errno == EINTR || errno == EAGAIN) {
                elapsed = ast_tvdiff_ms(ast_tvnow(), start);
                if (elapsed >= timeoutms) {
                    return -1;
                }
                /* This was an acceptable error, go back into poll() */
                continue;
            }
 
            /* Fatal error, bail. */
            ast_log(LOG_ERROR, "poll returned error: %s\n", strerror(errno));
 
            return -1;
        }
        elapsed = ast_tvdiff_ms(ast_tvnow(), start);
        if (elapsed >= timeoutms) {
            return -1;
        }
    }
 
    return 0;
}
 
/*!
 * Try to write string, but wait no more than ms milliseconds before timing out.
 *
 * \note The code assumes that the file descriptor has NONBLOCK set,
 * so there is only one system call made to do a write, unless we actually
 * have a need to wait.  This way, we get better performance.
 * If the descriptor is blocking, all assumptions on the guaranteed
 * detail do not apply anymore.
 */
int ast_carefulwrite(int fd, char *s, int len, int timeoutms)
{
    struct timeval start = ast_tvnow();
    int res = 0;
    int elapsed = 0;
 
    while (len) {
        if (wait_for_output(fd, timeoutms - elapsed)) {
            return -1;
        }
 
        res = write(fd, s, len);
 
        if (res < 0 && errno != EAGAIN && errno != EINTR) {
            /* fatal error from write() */
            if (errno == EPIPE) {
#ifndef STANDALONE
                ast_debug(1, "write() failed due to reading end being closed: %s\n", strerror(errno));
#endif
            } else {
                ast_log(LOG_ERROR, "write() returned error: %s\n", strerror(errno));
            }
            return -1;
        }
 
        if (res < 0) {
            /* It was an acceptable error */
            res = 0;
        }
 
        /* Update how much data we have left to write */
        len -= res;
        s += res;
        res = 0;
 
        elapsed = ast_tvdiff_ms(ast_tvnow(), start);
        if (elapsed >= timeoutms) {
            /* We've taken too long to write
             * This is only an error condition if we haven't finished writing. */
            res = len ? -1 : 0;
            break;
        }
    }
 
    return res;
}
 
char *ast_strip_quoted(char *s, const char *beg_quotes, const char *end_quotes)
{
    char *e;
    const char *q;
 
    s = ast_strip(s);
    if ((q = strchr(beg_quotes, *s)) && *q != '\0') {
        e = s + strlen(s) - 1;
        if (*e == *(end_quotes + (q - beg_quotes))) {
            s++;
            *e = '\0';
        }
    }
 
    return s;
}
 
char *ast_strsep(char **iss, const char sep, uint32_t flags)
{
    char *st = *iss;
    char *is;
    int inquote = 0;
    int found = 0;
    char stack[8];
 
    if (ast_strlen_zero(st)) {
        *iss = NULL;
        return st;
    }
 
    memset(stack, 0, sizeof(stack));
 
    for(is = st; *is; is++) {
        if (*is == '\\') {
            if (*++is != '\0') {
                is++;
            } else {
                break;
            }
        }
 
        if (*is == '\'' || *is == '"') {
            if (*is == stack[inquote]) {
                stack[inquote--] = '\0';
            } else {
                if (++inquote >= sizeof(stack)) {
                    return NULL;
                }
                stack[inquote] = *is;
            }
        }
 
        if (*is == sep && !inquote) {
            *is = '\0';
            found = 1;
            *iss = is + 1;
            break;
        }
    }
    if (!found) {
        *iss = NULL;
    }
 
    if (flags & AST_STRSEP_STRIP) {
        st = ast_strip_quoted(st, "'\"", "'\"");
    }
 
    if (flags & AST_STRSEP_TRIM) {
        char *trimmed = ast_strip(st);
        if (!ast_strlen_zero(trimmed)) {
            st = trimmed;
        }
    }
 
    if (flags & AST_STRSEP_UNESCAPE) {
        ast_unescape_quoted(st);
    }
 
    return st;
}
 
char *ast_strsep_quoted(char **iss, const char sep, const char quote, uint32_t flags)
{
    char *st = *iss;
    char *is;
    int inquote = 0;
    int found = 0;
    char stack[8];
    const char qstr[] = { quote };
 
    if (ast_strlen_zero(st)) {
        *iss = NULL;
        return st;
    }
 
    memset(stack, 0, sizeof(stack));
 
    for(is = st; *is; is++) {
        if (*is == '\\') {
            if (*++is != '\0') {
                is++;
            } else {
                break;
            }
        }
 
        if (*is == quote) {
            if (*is == stack[inquote]) {
                stack[inquote--] = '\0';
            } else {
                if (++inquote >= sizeof(stack)) {
                    return NULL;
                }
                stack[inquote] = *is;
            }
        }
 
        if (*is == sep && !inquote) {
            *is = '\0';
            found = 1;
            *iss = is + 1;
            break;
        }
    }
    if (!found) {
        *iss = NULL;
    }
 
    if (flags & AST_STRSEP_STRIP) {
        st = ast_strip_quoted(st, qstr, qstr);
    }
 
    if (flags & AST_STRSEP_TRIM) {
        char *trimmed = ast_strip(st);
        if (!ast_strlen_zero(trimmed)) {
            st = trimmed;
        }
    }
 
    if (flags & AST_STRSEP_UNESCAPE) {
        ast_unescape_quoted(st);
    }
 
    return st;
}
 
char *ast_unescape_semicolon(char *s)
{
    char *e;
    char *work = s;
 
    while ((e = strchr(work, ';'))) {
        if ((e > work) && (*(e-1) == '\\')) {
            memmove(e - 1, e, strlen(e) + 1);
            work = e;
        } else {
            work = e + 1;
        }
    }
 
    return s;
}
 
/* !\brief unescape some C sequences in place, return pointer to the original string.
 */
char *ast_unescape_c(char *src)
{
    char c, *ret, *dst;
 
    if (src == NULL)
        return NULL;
    for (ret = dst = src; (c = *src++); *dst++ = c ) {
        if (c != '\\')
            continue;   /* copy char at the end of the loop */
        switch ((c = *src++)) {
        case '\0':  /* special, trailing '\' */
            c = '\\';
            break;
        case 'b':   /* backspace */
            c = '\b';
            break;
        case 'f':   /* form feed */
            c = '\f';
            break;
        case 'n':
            c = '\n';
            break;
        case 'r':
            c = '\r';
            break;
        case 't':
            c = '\t';
            break;
        }
        /* default, use the char literally */
    }
    *dst = '\0';
    return ret;
}
 
/*
 * Standard escape sequences - Note, '\0' is not included as a valid character
 * to escape, but instead is used here as a NULL terminator for the string.
 */
char escape_sequences[] = {
    '\a', '\b', '\f', '\n', '\r', '\t', '\v', '\\', '\'', '\"', '\?', '\0'
};
 
/*
 * Standard escape sequences output map (has to maintain matching order with
 * escape_sequences). '\0' is included here as a NULL terminator for the string.
 */
static char escape_sequences_map[] = {
    'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', '\'', '"', '?', '\0'
};
 
char *ast_escape(char *dest, const char *s, size_t size, const char *to_escape)
{
    char *p;
    char *c;
 
    if (!dest || !size) {
        return dest;
    }
    if (ast_strlen_zero(s)) {
        *dest = '\0';
        return dest;
    }
 
    if (ast_strlen_zero(to_escape)) {
        ast_copy_string(dest, s, size);
        return dest;
    }
 
    for (p = dest; *s && --size; ++s, ++p) {
        /* If in the list of characters to escape then escape it */
        if (strchr(to_escape, *s)) {
            if (!--size) {
                /* Not enough room left for the escape sequence. */
                break;
            }
 
            /*
             * See if the character to escape is part of the standard escape
             * sequences. If so we'll have to use its mapped counterpart
             * otherwise just use the current character.
             */
            c = strchr(escape_sequences, *s);
            *p++ = '\\';
            *p = c ? escape_sequences_map[c - escape_sequences] : *s;
        } else {
            *p = *s;
        }
    }
    *p = '\0';
 
    return dest;
}
 
char *ast_escape_c(char *dest, const char *s, size_t size)
{
    /*
     * Note - This is an optimized version of ast_escape. When looking only
     * for escape_sequences a couple of checks used in the generic case can
     * be left out thus making it slightly more efficient.
     */
    char *p;
    char *c;
 
    if (!dest || !size) {
        return dest;
    }
    if (ast_strlen_zero(s)) {
        *dest = '\0';
        return dest;
    }
 
    for (p = dest; *s && --size; ++s, ++p) {
        /*
         * See if the character to escape is part of the standard escape
         * sequences. If so use its mapped counterpart.
         */
        c = strchr(escape_sequences, *s);
        if (c) {
            if (!--size) {
                /* Not enough room left for the escape sequence. */
                break;
            }
 
            *p++ = '\\';
            *p = escape_sequences_map[c - escape_sequences];
        } else {
            *p = *s;
        }
    }
    *p = '\0';
 
    return dest;
}
 
static char *escape_alloc(const char *s, size_t *size)
{
    if (!s) {
        return NULL;
    }
 
    /*
     * The result string needs to be twice the size of the given
     * string just in case every character in it needs to be escaped.
     */
    *size = strlen(s) * 2 + 1;
    return ast_malloc(*size);
}
 
char *ast_escape_alloc(const char *s, const char *to_escape)
{
    size_t size = 0;
    char *dest = escape_alloc(s, &size);
 
    return ast_escape(dest, s, size, to_escape);
}
 
char *ast_escape_c_alloc(const char *s)
{
    size_t size = 0;
    char *dest = escape_alloc(s, &size);
 
    return ast_escape_c(dest, s, size);
}
 
int ast_build_string_va(char **buffer, size_t *space, const char *fmt, va_list ap)
{
    int result;
 
    if (!buffer || !*buffer || !space || !*space)
        return -1;
 
    result = vsnprintf(*buffer, *space, fmt, ap);
 
    if (result < 0)
        return -1;
    else if (result > *space)
        result = *space;
 
    *buffer += result;
    *space -= result;
    return 0;
}
 
int ast_build_string(char **buffer, size_t *space, const char *fmt, ...)
{
    va_list ap;
    int result;
 
    va_start(ap, fmt);
    result = ast_build_string_va(buffer, space, fmt, ap);
    va_end(ap);
 
    return result;
}
 
int ast_regex_string_to_regex_pattern(const char *regex_string, struct ast_str **regex_pattern)
{
    int regex_len = strlen(regex_string);
    int ret = 3;
 
    /* Chop off the leading / if there is one */
    if ((regex_len >= 1) && (regex_string[0] == '/')) {
        ast_str_set(regex_pattern, 0, "%s", regex_string + 1);
        ret -= 2;
    }
 
    /* Chop off the ending / if there is one */
    if ((regex_len > 1) && (regex_string[regex_len - 1] == '/')) {
        ast_str_truncate(*regex_pattern, -1);
        ret -= 1;
    }
 
    return ret;
}
 
int ast_true(const char *s)
{
    if (ast_strlen_zero(s))
        return 0;
 
    /* Determine if this is a true value */
    if (!strcasecmp(s, "yes") ||
        !strcasecmp(s, "true") ||
        !strcasecmp(s, "y") ||
        !strcasecmp(s, "t") ||
        !strcasecmp(s, "1") ||
        !strcasecmp(s, "on"))
        return -1;
 
    return 0;
}
 
int ast_false(const char *s)
{
    if (ast_strlen_zero(s))
        return 0;
 
    /* Determine if this is a false value */
    if (!strcasecmp(s, "no") ||
        !strcasecmp(s, "false") ||
        !strcasecmp(s, "n") ||
        !strcasecmp(s, "f") ||
        !strcasecmp(s, "0") ||
        !strcasecmp(s, "off"))
        return -1;
 
    return 0;
}
 
#define ONE_MILLION 1000000
/*
 * put timeval in a valid range. usec is 0..999999
 * negative values are not allowed and truncated.
 */
static struct timeval tvfix(struct timeval a)
{
    if (a.tv_usec >= ONE_MILLION) {
        ast_log(LOG_WARNING, "warning too large timestamp %ld.%ld\n",
            (long)a.tv_sec, (long int) a.tv_usec);
        a.tv_sec += a.tv_usec / ONE_MILLION;
        a.tv_usec %= ONE_MILLION;
    } else if (a.tv_usec < 0) {
        ast_log(LOG_WARNING, "warning negative timestamp %ld.%ld\n",
            (long)a.tv_sec, (long int) a.tv_usec);
        a.tv_usec = 0;
    }
    return a;
}
 
struct timeval ast_tvadd(struct timeval a, struct timeval b)
{
    /* consistency checks to guarantee usec in 0..999999 */
    a = tvfix(a);
    b = tvfix(b);
    a.tv_sec += b.tv_sec;
    a.tv_usec += b.tv_usec;
    if (a.tv_usec >= ONE_MILLION) {
        a.tv_sec++;
        a.tv_usec -= ONE_MILLION;
    }
    return a;
}
 
struct timeval ast_tvsub(struct timeval a, struct timeval b)
{
    /* consistency checks to guarantee usec in 0..999999 */
    a = tvfix(a);
    b = tvfix(b);
    a.tv_sec -= b.tv_sec;
    a.tv_usec -= b.tv_usec;
    if (a.tv_usec < 0) {
        a.tv_sec-- ;
        a.tv_usec += ONE_MILLION;
    }
    return a;
}
 
int ast_remaining_ms(struct timeval start, int max_ms)
{
    int ms;
 
    if (max_ms < 0) {
        ms = max_ms;
    } else {
        ms = max_ms - ast_tvdiff_ms(ast_tvnow(), start);
        if (ms < 0) {
            ms = 0;
        }
    }
 
    return ms;
}
 
void ast_format_duration_hh_mm_ss(int duration, char *buf, size_t length)
{
    int durh, durm, durs;
    durh = duration / 3600;
    durm = (duration % 3600) / 60;
    durs = duration % 60;
    snprintf(buf, length, "%02d:%02d:%02d", durh, durm, durs);
}
 
#undef ONE_MILLION
 
#ifndef linux
AST_MUTEX_DEFINE_STATIC(randomlock);
#endif
 
long int ast_random(void)
{
    long int res;
 
    if (dev_urandom_fd >= 0) {
        int read_res = read(dev_urandom_fd, &res, sizeof(res));
        if (read_res > 0) {
            long int rm = RAND_MAX;
            res = res < 0 ? ~res : res;
            rm++;
            return res % rm;
        }
    }
 
    /* XXX - Thread safety really depends on the libc, not the OS.
     *
     * But... popular Linux libc's (uClibc, glibc, eglibc), all have a
     * somewhat thread safe random(3) (results are random, but not
     * reproducible). The libc's for other systems (BSD, et al.), not so
     * much.
     */
#ifdef linux
    res = random();
#else
    ast_mutex_lock(&randomlock);
    res = random();
    ast_mutex_unlock(&randomlock);
#endif
    return res;
}
 
void ast_replace_subargument_delimiter(char *s)
{
    for (; *s; s++) {
        if (*s == '^') {
            *s = ',';
        }
    }
}
 
char *ast_process_quotes_and_slashes(char *start, char find, char replace_with)
{
    char *dataPut = start;
    int inEscape = 0;
    int inQuotes = 0;
 
    for (; *start; start++) {
        if (inEscape) {
            *dataPut++ = *start;       /* Always goes verbatim */
            inEscape = 0;
        } else {
            if (*start == '\\') {
                inEscape = 1;      /* Do not copy \ into the data */
            } else if (*start == '\'') {
                inQuotes = 1 - inQuotes;   /* Do not copy ' into the data */
            } else {
                /* Replace , with |, unless in quotes */
                *dataPut++ = inQuotes ? *start : ((*start == find) ? replace_with : *start);
            }
        }
    }
    if (start != dataPut)
        *dataPut = 0;
    return dataPut;
}
 
void ast_join_delim(char *s, size_t len, const char * const w[], unsigned int size, char delim)
{
    int x, ofs = 0;
    const char *src;
 
    /* Join words into a string */
    if (!s)
        return;
    for (x = 0; ofs < len && x < size && w[x] ; x++) {
        if (x > 0)
            s[ofs++] = delim;
        for (src = w[x]; *src && ofs < len; src++)
            s[ofs++] = *src;
    }
    if (ofs == len)
        ofs--;
    s[ofs] = '\0';
}
 
char *ast_to_camel_case_delim(const char *s, const char *delim)
{
    char *res = ast_strdup(s);
    char *front, *back, *buf = res;
    int size;
 
    front = strtok_r(buf, delim, &back);
 
    while (front) {
        size = strlen(front);
        *front = toupper(*front);
        ast_copy_string(buf, front, size + 1);
        buf += size;
        front = strtok_r(NULL, delim, &back);
    }
 
    return res;
}
 
/*! \brief
 * get values from config variables.
 */
int ast_get_timeval(const char *src, struct timeval *dst, struct timeval _default, int *consumed)
{
    long double dtv = 0.0;
    int scanned;
 
    if (dst == NULL)
        return -1;
 
    *dst = _default;
 
    if (ast_strlen_zero(src))
        return -1;
 
    /* only integer at the moment, but one day we could accept more formats */
    if (sscanf(src, "%30Lf%n", &dtv, &scanned) > 0) {
        dst->tv_sec = dtv;
        dst->tv_usec = (dtv - dst->tv_sec) * 1000000.0;
        if (consumed)
            *consumed = scanned;
        return 0;
    } else
        return -1;
}
 
/*! \brief
 * get values from config variables.
 */
int ast_get_time_t(const char *src, time_t *dst, time_t _default, int *consumed)
{
    long t;
    int scanned;
 
    if (dst == NULL)
        return -1;
 
    *dst = _default;
 
    if (ast_strlen_zero(src))
        return -1;
 
    /* only integer at the moment, but one day we could accept more formats */
    if (sscanf(src, "%30ld%n", &t, &scanned) == 1) {
        *dst = t;
        if (consumed)
            *consumed = scanned;
        return 0;
    } else
        return -1;
}
 
void ast_enable_packet_fragmentation(int sock)
{
#if defined(HAVE_IP_MTU_DISCOVER)
    int val = IP_PMTUDISC_DONT;
 
    if (setsockopt(sock, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val)))
        ast_log(LOG_WARNING, "Unable to disable PMTU discovery. Large UDP packets may fail to be delivered when sent from this socket.\n");
#endif /* HAVE_IP_MTU_DISCOVER */
}
 
int ast_mkdir(const char *path, int mode)
{
    char *ptr;
    int len = strlen(path), count = 0, x, piececount = 0;
    char *tmp = ast_strdupa(path);
    char **pieces;
    char *fullpath = ast_alloca(len + 1);
    int res = 0;
 
    for (ptr = tmp; *ptr; ptr++) {
        if (*ptr == '/')
            count++;
    }
 
    /* Count the components to the directory path */
    pieces = ast_alloca(count * sizeof(*pieces));
    for (ptr = tmp; *ptr; ptr++) {
        if (*ptr == '/') {
            *ptr = '\0';
            pieces[piececount++] = ptr + 1;
        }
    }
 
    *fullpath = '\0';
    for (x = 0; x < piececount; x++) {
        /* This looks funky, but the buffer is always ideally-sized, so it's fine. */
        strcat(fullpath, "/");
        strcat(fullpath, pieces[x]);
        res = mkdir(fullpath, mode);
        if (res && errno != EEXIST)
            return errno;
    }
    return 0;
}
 
static int safe_mkdir(const char *base_path, char *path, int mode)
{
    RAII_VAR(char *, absolute_path, NULL, ast_std_free);
 
    absolute_path = realpath(path, NULL);
 
    if (absolute_path) {
        /* Path exists, but is it in the right place? */
        if (!ast_begins_with(absolute_path, base_path)) {
            return EPERM;
        }
 
        /* It is in the right place! */
        return 0;
    } else {
        /* Path doesn't exist. */
 
        /* The slash terminating the subpath we're checking */
        char *path_term = strchr(path, '/');
        /* True indicates the parent path is within base_path */
        int parent_is_safe = 0;
        int res;
 
        while (path_term) {
            RAII_VAR(char *, absolute_subpath, NULL, ast_std_free);
 
            /* Truncate the path one past the slash */
            char c = *(path_term + 1);
            *(path_term + 1) = '\0';
            absolute_subpath = realpath(path, NULL);
 
            if (absolute_subpath) {
                /* Subpath exists, but is it safe? */
                parent_is_safe = ast_begins_with(
                    absolute_subpath, base_path);
            } else if (parent_is_safe) {
                /* Subpath does not exist, but parent is safe
                 * Create it */
                res = mkdir(path, mode);
                if (res != 0) {
                    ast_assert(errno != EEXIST);
                    return errno;
                }
            } else {
                /* Subpath did not exist, parent was not safe
                 * Fail! */
                errno = EPERM;
                return errno;
            }
            /* Restore the path */
            *(path_term + 1) = c;
            /* Move on to the next slash */
            path_term = strchr(path_term + 1, '/');
        }
 
        /* Now to build the final path, but only if it's safe */
        if (!parent_is_safe) {
            errno = EPERM;
            return errno;
        }
 
        res = mkdir(path, mode);
        if (res != 0 && errno != EEXIST) {
            return errno;
        }
 
        return 0;
    }
}
 
int ast_safe_mkdir(const char *base_path, const char *path, int mode)
{
    RAII_VAR(char *, absolute_base_path, NULL, ast_std_free);
    RAII_VAR(char *, p, NULL, ast_free);
 
    if (base_path == NULL || path == NULL) {
        errno = EFAULT;
        return errno;
    }
 
    p = ast_strdup(path);
    if (p == NULL) {
        errno = ENOMEM;
        return errno;
    }
 
    absolute_base_path = realpath(base_path, NULL);
    if (absolute_base_path == NULL) {
        return errno;
    }
 
    return safe_mkdir(absolute_base_path, p, mode);
}
 
static void utils_shutdown(void)
{
    close(dev_urandom_fd);
    dev_urandom_fd = -1;
#if defined(DEBUG_THREADS) && !defined(LOW_MEMORY)
    ast_cli_unregister_multiple(utils_cli, ARRAY_LEN(utils_cli));
#endif
}
 
int ast_utils_init(void)
{
    dev_urandom_fd = open("/dev/urandom", O_RDONLY);
    base64_init();
#ifdef DEBUG_THREADS
#if !defined(LOW_MEMORY)
    ast_cli_register_multiple(utils_cli, ARRAY_LEN(utils_cli));
#endif
#endif
    ast_register_cleanup(utils_shutdown);
    return 0;
}
 
 
/*!
 *\brief Parse digest authorization header.
 *\return Returns -1 if we have no auth or something wrong with digest.
 *\note This function may be used for Digest request and response header.
 * request arg is set to nonzero, if we parse Digest Request.
 * pedantic arg can be set to nonzero if we need to do addition Digest check.
 */
int ast_parse_digest(const char *digest, struct ast_http_digest *d, int request, int pedantic) {
    char *c;
    struct ast_str *str = ast_str_create(16);
 
    /* table of recognised keywords, and places where they should be copied */
    const struct x {
        const char *key;
        const ast_string_field *field;
    } *i, keys[] = {
        { "username=", &d->username },
        { "realm=", &d->realm },
        { "nonce=", &d->nonce },
        { "uri=", &d->uri },
        { "domain=", &d->domain },
        { "response=", &d->response },
        { "cnonce=", &d->cnonce },
        { "opaque=", &d->opaque },
        /* Special cases that cannot be directly copied */
        { "algorithm=", NULL },
        { "qop=", NULL },
        { "nc=", NULL },
        { NULL, 0 },
    };
 
    if (ast_strlen_zero(digest) || !d || !str) {
        ast_free(str);
        return -1;
    }
 
    ast_str_set(&str, 0, "%s", digest);
 
    c = ast_skip_blanks(ast_str_buffer(str));
 
    if (strncasecmp(c, "Digest ", strlen("Digest "))) {
        ast_log(LOG_WARNING, "Missing Digest.\n");
        ast_free(str);
        return -1;
    }
    c += strlen("Digest ");
 
    /* lookup for keys/value pair */
    while (c && *c && *(c = ast_skip_blanks(c))) {
        /* find key */
        for (i = keys; i->key != NULL; i++) {
            char *src, *separator;
            int unescape = 0;
            if (strncasecmp(c, i->key, strlen(i->key)) != 0) {
                continue;
            }
 
            /* Found. Skip keyword, take text in quotes or up to the separator. */
            c += strlen(i->key);
            if (*c == '"') {
                src = ++c;
                separator = "\"";
                unescape = 1;
            } else {
                src = c;
                separator = ",";
            }
            strsep(&c, separator); /* clear separator and move ptr */
            if (unescape) {
                ast_unescape_c(src);
            }
            if (i->field) {
                ast_string_field_ptr_set(d, i->field, src);
            } else {
                /* Special cases that require additional processing */
                if (!strcasecmp(i->key, "algorithm=")) {
                    if (strcasecmp(src, "MD5")) {
                        ast_log(LOG_WARNING, "Digest algorithm: \"%s\" not supported.\n", src);
                        ast_free(str);
                        return -1;
                    }
                } else if (!strcasecmp(i->key, "qop=") && !strcasecmp(src, "auth")) {
                    d->qop = 1;
                } else if (!strcasecmp(i->key, "nc=")) {
                    unsigned long u;
                    if (sscanf(src, "%30lx", &u) != 1) {
                        ast_log(LOG_WARNING, "Incorrect Digest nc value: \"%s\".\n", src);
                        ast_free(str);
                        return -1;
                    }
                    ast_string_field_set(d, nc, src);
                }
            }
            break;
        }
        if (i->key == NULL) { /* not found, try ',' */
            strsep(&c, ",");
        }
    }
    ast_free(str);
 
    /* Digest checkout */
    if (ast_strlen_zero(d->realm) || ast_strlen_zero(d->nonce)) {
        /* "realm" and "nonce" MUST be always exist */
        return -1;
    }
 
    if (!request) {
        /* Additional check for Digest response */
        if (ast_strlen_zero(d->username) || ast_strlen_zero(d->uri) || ast_strlen_zero(d->response)) {
            return -1;
        }
 
        if (pedantic && d->qop && (ast_strlen_zero(d->cnonce) || ast_strlen_zero(d->nc))) {
            return -1;
        }
    }
 
    return 0;
}
 
int ast_get_tid(void)
{
    int ret = -1;
#if defined (__linux) && defined(SYS_gettid)
    ret = syscall(SYS_gettid); /* available since Linux 1.4.11 */
#elif defined(__sun)
    ret = pthread_self();
#elif defined(__APPLE__)
    ret = mach_thread_self();
    mach_port_deallocate(mach_task_self(), ret);
#elif defined(__FreeBSD__)
    long lwpid;
    thr_self(&lwpid);
    ret = lwpid;
#elif defined(__NetBSD__)
    ret = _lwp_self();
#elif defined(__OpenBSD__)
    ret = getthrid();
#endif
    return ret;
}
 
char *ast_utils_which(const char *binary, char *fullpath, size_t fullpath_size)
{
    const char *envPATH = getenv("PATH");
    char *tpath, *path;
    struct stat unused;
    if (!envPATH) {
        return NULL;
    }
    tpath = ast_strdupa(envPATH);
    while ((path = strsep(&tpath, ":"))) {
        snprintf(fullpath, fullpath_size, "%s/%s", path, binary);
        if (!stat(fullpath, &unused)) {
            return fullpath;
        }
    }
    return NULL;
}
 
int ast_check_ipv6(void)
{
    int udp6_socket = socket(AF_INET6, SOCK_DGRAM, 0);
 
    if (udp6_socket < 0) {
        return 0;
    }
 
    close(udp6_socket);
    return 1;
}
 
void DO_CRASH_NORETURN ast_do_crash(void)
{
#if defined(DO_CRASH)
    abort();
    /*
     * Just in case abort() doesn't work or something else super
     * silly, and for Qwell's amusement.
     */
    *((int *) 0) = 0;
#endif  /* defined(DO_CRASH) */
}
 
void DO_CRASH_NORETURN __ast_assert_failed(int condition, const char *condition_str, const char *file, int line, const char *function)
{
    /*
     * Attempt to put it into the logger, but hope that at least
     * someone saw the message on stderr ...
     */
    fprintf(stderr, "FRACK!, Failed assertion %s (%d) at line %d in %s of %s\n",
        condition_str, condition, line, function, file);
    ast_log(__LOG_ERROR, file, line, function, "FRACK!, Failed assertion %s (%d)\n",
        condition_str, condition);
 
    /* Generate a backtrace for the assert */
    ast_log_backtrace();
 
    /*
     * Give the logger a chance to get the message out, just in case
     * we abort(), or Asterisk crashes due to whatever problem just
     * happened after we exit ast_assert().
     */
    usleep(1);
    ast_do_crash();
}
 
char *ast_eid_to_str(char *s, int maxlen, struct ast_eid *eid)
{
    int x;
    char *os = s;
    if (maxlen < 18) {
        if (s && (maxlen > 0)) {
            *s = '\0';
        }
    } else {
        for (x = 0; x < 5; x++) {
            sprintf(s, "%02hhx:", eid->eid[x]);
            s += 3;
        }
        sprintf(s, "%02hhx", eid->eid[5]);
    }
    return os;
}
 
#if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) || defined(__Darwin__)
#include <ifaddrs.h>
#include <net/if_dl.h>
 
void ast_set_default_eid(struct ast_eid *eid)
{
    struct ifaddrs *ifap, *ifaphead;
    int rtnerr;
    const struct sockaddr_dl *sdl;
    int alen;
    caddr_t ap;
    char eid_str[20];
    unsigned char empty_mac[6] = {0, 0, 0, 0, 0, 0};
    unsigned char full_mac[6]  = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
    rtnerr = getifaddrs(&ifaphead);
    if (rtnerr) {
        ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
            "You will have to set it manually.\n");
        return;
    }
 
    if (!ifaphead) {
        ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
            "You will have to set it manually.\n");
        return;
    }
 
    for (ifap = ifaphead; ifap; ifap = ifap->ifa_next) {
        if (ifap->ifa_addr->sa_family != AF_LINK) {
            continue;
        }
 
        sdl = (const struct sockaddr_dl *) ifap->ifa_addr;
        ap = ((caddr_t) ((sdl)->sdl_data + (sdl)->sdl_nlen));
        alen = sdl->sdl_alen;
        if (alen != 6 || !(memcmp(ap, &empty_mac, 6) && memcmp(ap, &full_mac, 6))) {
            continue;
        }
 
        memcpy(eid, ap, sizeof(*eid));
        ast_debug(1, "Seeding global EID '%s'\n",
                ast_eid_to_str(eid_str, sizeof(eid_str), eid));
        freeifaddrs(ifaphead);
        return;
    }
 
    ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
        "You will have to set it manually.\n");
    freeifaddrs(ifaphead);
 
    return;
}
 
#elif defined(SOLARIS)
#include <sys/sockio.h>
#include <net/if_arp.h>
 
void ast_set_default_eid(struct ast_eid *eid)
{
    int s;
    int x;
    struct lifreq *ifr = NULL;
    struct lifnum ifn;
    struct lifconf ifc;
    struct arpreq ar;
    struct sockaddr_in *sa, *sa2;
    char *buf = NULL;
    char eid_str[20];
    int bufsz;
    unsigned char empty_mac[6] = {0, 0, 0, 0, 0, 0};
    unsigned char full_mac[6]  = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (s <= 0) {
        ast_log(LOG_WARNING, "Unable to open a socket for seeding global EID. "
            " You will have to set it manually.\n");
        return;
    }
 
    /* Get a count of interfaces on the machine */
    ifn.lifn_family = AF_UNSPEC;
    ifn.lifn_flags = 0;
    ifn.lifn_count = 0;
    if (ioctl(s, SIOCGLIFNUM, &ifn) < 0) {
        ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
            " You will have to set it manually.\n");
        close(s);
        return;
    }
 
    bufsz = ifn.lifn_count * sizeof(struct lifreq);
    if (!(buf = ast_malloc(bufsz))) {
        ast_log(LOG_WARNING, "Unable to allocate memory for seeding global EID. "
            "You will have to set it manually.\n");
        close(s);
        return;
    }
    memset(buf, 0, bufsz);
 
    /* Get a list of interfaces on the machine */
    ifc.lifc_len = bufsz;
    ifc.lifc_buf = buf;
    ifc.lifc_family = AF_UNSPEC;
    ifc.lifc_flags = 0;
    if (ioctl(s, SIOCGLIFCONF, &ifc) < 0) {
        ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
            "You will have to set it manually.\n");
        ast_free(buf);
        close(s);
        return;
    }
 
    for (ifr = (struct lifreq *)buf, x = 0; x < ifn.lifn_count; ifr++, x++) {
        unsigned char *p;
 
        sa = (struct sockaddr_in *)&(ifr->lifr_addr);
        sa2 = (struct sockaddr_in *)&(ar.arp_pa);
        *sa2 = *sa;
 
        if(ioctl(s, SIOCGARP, &ar) >= 0) {
            p = (unsigned char *)&(ar.arp_ha.sa_data);
            if (!(memcmp(p, &empty_mac, 6) && memcmp(p, &full_mac, 6))) {
                continue;
            }
 
            memcpy(eid, p, sizeof(*eid));
            ast_debug(1, "Seeding global EID '%s'\n",
                ast_eid_to_str(eid_str, sizeof(eid_str), eid));
            ast_free(buf);
            close(s);
            return;
        }
    }
 
    ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
        "You will have to set it manually.\n");
    ast_free(buf);
    close(s);
 
    return;
}
 
#else
void ast_set_default_eid(struct ast_eid *eid)
{
    int s;
    int i;
    struct ifreq *ifr;
    struct ifreq *ifrp;
    struct ifconf ifc;
    char *buf = NULL;
    char eid_str[20];
    int bufsz, num_interfaces;
    unsigned char empty_mac[6] = {0, 0, 0, 0, 0, 0};
    unsigned char full_mac[6]  = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (s < 0) {
        ast_log(LOG_WARNING, "Unable to open socket for seeding global EID. "
            "You will have to set it manually.\n");
        return;
    }
 
    ifc.ifc_len = 0;
    ifc.ifc_buf = NULL;
    if (ioctl(s, SIOCGIFCONF, &ifc) || ifc.ifc_len <= 0) {
        ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
            "You will have to set it manually.\n");
        close(s);
        return;
    }
    bufsz = ifc.ifc_len;
 
    if (!(buf = ast_malloc(bufsz))) {
        ast_log(LOG_WARNING, "Unable to allocate memory for seeding global EID. "
            "You will have to set it manually.\n");
        close(s);
        return;
    }
 
    ifc.ifc_buf = buf;
    if (ioctl(s, SIOCGIFCONF, &ifc) < 0) {
        ast_log(LOG_WARNING, "Unable to retrieve ethernet interfaces for seeding global EID. "
            "You will have to set it manually.\n");
        ast_free(buf);
        close(s);
        return;
    }
 
    ifrp = ifc.ifc_req;
    num_interfaces = ifc.ifc_len / sizeof(*ifr);
 
    for (i = 0; i < num_interfaces; i++) {
        ifr = &ifrp[i];
        if (!ioctl(s, SIOCGIFHWADDR, ifr)) {
            unsigned char *hwaddr = (unsigned char *) ifr->ifr_hwaddr.sa_data;
 
            if (!(memcmp(hwaddr, &empty_mac, 6) && memcmp(hwaddr, &full_mac, 6))) {
                continue;
            }
 
            memcpy(eid, hwaddr, sizeof(*eid));
            ast_debug(1, "Seeding global EID '%s' from '%s' using 'siocgifhwaddr'\n",
                ast_eid_to_str(eid_str, sizeof(eid_str), eid), ifr->ifr_name);
            ast_free(buf);
            close(s);
            return;
        }
    }
 
    ast_log(LOG_WARNING, "No ethernet interface found for seeding global EID. "
        "You will have to set it manually.\n");
    ast_free(buf);
    close(s);
 
    return;
}
#endif /* LINUX */
 
int ast_str_to_eid(struct ast_eid *eid, const char *s)
{
    unsigned int eid_int[6];
    int x;
 
    if (sscanf(s, "%2x:%2x:%2x:%2x:%2x:%2x", &eid_int[0], &eid_int[1], &eid_int[2],
         &eid_int[3], &eid_int[4], &eid_int[5]) != 6) {
            return -1;
    }
 
    for (x = 0; x < 6; x++) {
        eid->eid[x] = eid_int[x];
    }
 
    return 0;
}
 
int ast_eid_cmp(const struct ast_eid *eid1, const struct ast_eid *eid2)
{
    return memcmp(eid1, eid2, sizeof(*eid1));
}
 
int ast_eid_is_empty(const struct ast_eid *eid)
{
    struct ast_eid empty_eid;
 
    memset(&empty_eid, 0, sizeof(empty_eid));
    return memcmp(eid, &empty_eid, sizeof(empty_eid)) ? 0 : 1;
}
 
int ast_file_is_readable(const char *filename)
{
#if defined(HAVE_EACCESS) || defined(HAVE_EUIDACCESS)
#if defined(HAVE_EUIDACCESS) && !defined(HAVE_EACCESS)
#define eaccess euidaccess
#endif
    return eaccess(filename, R_OK) == 0;
#else
    int fd = open(filename, O_RDONLY |  O_NONBLOCK);
    if (fd < 0) {
        return 0;
    }
    close(fd);
    return 1;
#endif
}
 
int ast_compare_versions(const char *version1, const char *version2)
{
    unsigned int major[2] = { 0 };
    unsigned int minor[2] = { 0 };
    unsigned int patch[2] = { 0 };
    unsigned int extra[2] = { 0 };
    int res;
 
    sscanf(version1, "%u.%u.%u.%u", &major[0], &minor[0], &patch[0], &extra[0]);
    sscanf(version2, "%u.%u.%u.%u", &major[1], &minor[1], &patch[1], &extra[1]);
 
    res = major[0] - major[1];
    if (res) {
        return res;
    }
    res = minor[0] - minor[1];
    if (res) {
        return res;
    }
    res = patch[0] - patch[1];
    if (res) {
        return res;
    }
    return extra[0] - extra[1];
}
 
int __ast_fd_set_flags(int fd, int flags, enum ast_fd_flag_operation op,
    const char *file, int lineno, const char *function)
{
    int f;
 
    f = fcntl(fd, F_GETFL);
    if (f == -1) {
        ast_log(__LOG_ERROR, file, lineno, function,
            "Failed to get fcntl() flags for file descriptor: %s\n", strerror(errno));
        return -1;
    }
 
    switch (op) {
    case AST_FD_FLAG_SET:
        if ((f & flags) == flags) {
            /* There is nothing to set */
            return 0;
        }
        f |= flags;
        break;
    case AST_FD_FLAG_CLEAR:
        if (!(f & flags)) {
            /* There is nothing to clear */
            return 0;
        }
        f &= ~flags;
        break;
    default:
        ast_assert(0);
        break;
    }
 
    f = fcntl(fd, F_SETFL, f);
    if (f == -1) {
        ast_log(__LOG_ERROR, file, lineno, function,
            "Failed to set fcntl() flags for file descriptor: %s\n", strerror(errno));
        return -1;
    }
 
    return 0;
}
 
#ifndef HAVE_SOCK_NONBLOCK
int ast_socket_nonblock(int domain, int type, int protocol)
{
    int s = socket(domain, type, protocol);
    if (s < 0) {
        return -1;
    }
 
    if (ast_fd_set_flags(s, O_NONBLOCK)) {
        close(s);
        return -1;
    }
 
    return s;
}
#endif
 
#ifndef HAVE_PIPE2
int ast_pipe_nonblock(int filedes[2])
{
    int p = pipe(filedes);
    if (p < 0) {
        return -1;
    }
 
    if (ast_fd_set_flags(filedes[0], O_NONBLOCK)
       || ast_fd_set_flags(filedes[1], O_NONBLOCK)) {
        close(filedes[0]);
        close(filedes[1]);
        return -1;
    }
 
    return 0;
}
#endif
 
/*!
 * \brief A thread local indicating whether the current thread is a user interface.
 */
AST_THREADSTORAGE(thread_user_interface_tl);
 
int ast_thread_user_interface_set(int is_user_interface)
{
    int *thread_user_interface;
 
    thread_user_interface = ast_threadstorage_get(
        &thread_user_interface_tl, sizeof(*thread_user_interface));
    if (thread_user_interface == NULL) {
        ast_log(LOG_ERROR, "Error setting user interface status for current thread\n");
        return -1;
    }
 
    *thread_user_interface = !!is_user_interface;
    return 0;
}
 
int ast_thread_is_user_interface(void)
{
    int *thread_user_interface;
 
    thread_user_interface = ast_threadstorage_get(
        &thread_user_interface_tl, sizeof(*thread_user_interface));
    if (thread_user_interface == NULL) {
        ast_log(LOG_ERROR, "Error checking thread's user interface status\n");
        /* On error, assume that we are not a user interface thread */
        return 0;
    }
 
    return *thread_user_interface;
}
 
int ast_check_command_in_path(const char *cmd)
{
    char *token, *saveptr, *path = getenv("PATH");
    char filename[PATH_MAX];
    int len;
 
    if (path == NULL) {
        return 0;
    }
 
    path = ast_strdup(path);
    if (path == NULL) {
        return 0;
    }
 
    token = strtok_r(path, ":", &saveptr);
    while (token != NULL) {
        len = snprintf(filename, sizeof(filename), "%s/%s", token, cmd);
        if (len < 0 || len >= sizeof(filename)) {
            ast_log(LOG_WARNING, "Path constructed with '%s' too long; skipping\n", token);
            continue;
        }
 
        if (access(filename, X_OK) == 0) {
            ast_free(path);
            return 1;
        }
 
        token = strtok_r(NULL, ":", &saveptr);
    }
    ast_free(path);
    return 0;
}