/*
 * 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;
}

