asterisk/utils.c

/*
 * 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.
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.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/logger.h"
#include "asterisk/md5.h"
#include "asterisk/sha1.h"
#include "asterisk/options.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/stringfields.h"

#define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/utils.h"

static char base64[64];
static char b2a[256];

#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined( __NetBSD__ ) || defined(__APPLE__) || defined(__CYGWIN__)

#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)
{
	int res;
	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;
	res = 0;
	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_addr_list = (void *) hp->buf;
		hp->hp.h_addr = hp->buf + sizeof(void *);
		if (inet_pton(AF_INET, host, hp->hp.h_addr) > 0)
			return &hp->hp;
		return NULL;
		
	}
#ifdef SOLARIS
	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;
}



AST_MUTEX_DEFINE_STATIC(test_lock);
AST_MUTEX_DEFINE_STATIC(test_lock2);
static pthread_t test_thread; 
static int lock_count = 0;
static int test_errors = 0;

/*! \brief This is a regression test for recursive mutexes.
   test_for_thread_safety() will return 0 if recursive mutex locks are
   working properly, and non-zero if they are not working properly. */
static void *test_thread_body(void *data) 
{ 
	ast_mutex_lock(&test_lock);
	lock_count += 10;
	if (lock_count != 10) 
		test_errors++;
	ast_mutex_lock(&test_lock);
	lock_count += 10;
	if (lock_count != 20) 
		test_errors++;
	ast_mutex_lock(&test_lock2);
	ast_mutex_unlock(&test_lock);
	lock_count -= 10;
	if (lock_count != 10) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 10;
	ast_mutex_unlock(&test_lock2);
	if (lock_count != 0) 
		test_errors++;
	return NULL;
} 

int test_for_thread_safety(void)
{ 
	ast_mutex_lock(&test_lock2);
	ast_mutex_lock(&test_lock);
	lock_count += 1;
	ast_mutex_lock(&test_lock);
	lock_count += 1;
	ast_pthread_create(&test_thread, NULL, test_thread_body, NULL); 
	usleep(100);
	if (lock_count != 2) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 1;
	usleep(100); 
	if (lock_count != 1) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 1;
	if (lock_count != 0) 
		test_errors++;
	ast_mutex_unlock(&test_lock2);
	usleep(100);
	if (lock_count != 0) 
		test_errors++;
	pthread_join(test_thread, NULL);
	return(test_errors);          /* return 0 on success. */
}

/*! \brief Produce 32 char MD5 hash of value. */
void ast_md5_hash(char *output, char *input)
{
	struct MD5Context md5;
	unsigned char digest[16];
	char *ptr;
	int x;

	MD5Init(&md5);
	MD5Update(&md5, (unsigned char *)input, strlen(input));
	MD5Final(digest, &md5);
	ptr = output;
	for (x=0; x<16; x++)
		ptr += sprintf(ptr, "%2.2x", digest[x]);
}

/*! \brief Produce 40 char SHA1 hash of value. */
void ast_sha1_hash(char *output, 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, "%2.2x", Message_Digest[x]);
}

/*! \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;
	int incnt = 0;
	while(*src && (cnt < max)) {
		/* Shift in 6 bits of input */
		byte <<= 6;
		byte |= (b2a[(int)(*src)]) & 0x3f;
		bits += 6;
		src++;
		incnt++;
		/* 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++;
		}
	}
	/* Dont worry about left over bits, they're extra anyway */
	return cnt;
}

/*! \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);
}

static void base64_init(void)
{
	int x;
	memset(b2a, -1, sizeof(b2a));
	/* Initialize base-64 Conversion table */
	for (x=0;x<26;x++) {
		/* A-Z */
		base64[x] = 'A' + x;
		b2a['A' + x] = x;
		/* a-z */
		base64[x + 26] = 'a' + x;
		b2a['a' + x] = x + 26;
		/* 0-9 */
		if (x < 10) {
			base64[x + 52] = '0' + x;
			b2a['0' + x] = x + 52;
		}
	}
	base64[62] = '+';
	base64[63] = '/';
	b2a[(int)'+'] = 62;
	b2a[(int)'/'] = 63;
#if 0
	for (x=0;x<64;x++) {
		if (b2a[(int)base64[x]] != x) {
			fprintf(stderr, "!!! %d failed\n", x);
		} else
			fprintf(stderr, "--- %d passed\n", x);
	}
#endif
}

/*! \brief  ast_uri_encode: Turn text string to URI-encoded %XX version
\note 	At this point, we're converting from ISO-8859-x (8-bit), not UTF8
	as in the SIP protocol spec 
	If doreserved == 1 we will convert reserved characters also.
	RFC 2396, section 2.4
	outbuf needs to have more memory allocated than the instring
	to have room for the expansion. Every char that is converted
	is replaced by three ASCII characters.

	Note: The doreserved option is needed for replaces header in
	SIP transfers.
*/
char *ast_uri_encode(const char *string, char *outbuf, int buflen, int doreserved) 
{
	char *reserved = ";/?:@&=+$, ";	/* Reserved chars */

 	const char *ptr  = string;	/* Start with the string */
	char *out = NULL;
	char *buf = NULL;

	strncpy(outbuf, string, buflen);

	/* If there's no characters to convert, just go through and don't do anything */
	while (*ptr) {
		if (((unsigned char) *ptr) > 127 || (doreserved && strchr(reserved, *ptr)) ) {
			/* Oops, we need to start working here */
			if (!buf) {
				buf = outbuf;
				out = buf + (ptr - string) ;	/* Set output ptr */
			}
			out += sprintf(out, "%%%02x", (unsigned char) *ptr);
		} else if (buf) {
			*out = *ptr;	/* Continue copying the string */
			out++;
		} 
		ptr++;
	}
	if (buf)
		*out = '\0';
	return outbuf;
}

/*! \brief  ast_uri_decode: Decode SIP URI, URN, URL (overwrite the string)  */
void ast_uri_decode(char *s) 
{
	char *o;
	unsigned int tmp;

	for (o = s; *s; s++, o++) {
		if (*s == '%' && strlen(s) > 2 && 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';
}

/*! \brief  ast_inet_ntoa: Recursive thread safe replacement of inet_ntoa */
const char *ast_inet_ntoa(char *buf, int bufsiz, struct in_addr ia)
{
	return inet_ntop(AF_INET, &ia, buf, bufsiz);
}

int ast_utils_init(void)
{
	base64_init();
	return 0;
}

#ifndef __linux__
#undef pthread_create /* For ast_pthread_create function only */
#endif /* !__linux__ */

/*
 * 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 with the MAC.
 */
static void *dummy_start(void *data)
{
	void *ret;
	struct thr_arg a = *((struct thr_arg *)data);	/* make a local copy */

	free(data);
	ast_register_thread(a.name);
	pthread_cleanup_push(ast_unregister_thread, (void *)pthread_self());	/* on unregister */
	ret = a.start_routine(a.data);
	pthread_cleanup_pop(1);
	return ret;
}

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)
{
	struct thr_arg *a;

	pthread_attr_t lattr;
	if (!attr) {
		pthread_attr_init(&lattr);
		attr = &lattr;
	}
#ifdef __linux__
	/* On Linux, 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(). */
	errno = pthread_attr_setinheritsched(attr, PTHREAD_INHERIT_SCHED);
	if (errno)
		ast_log(LOG_WARNING, "pthread_attr_setinheritsched returned non-zero: %s\n", strerror(errno));
#endif

	if (!stacksize)
		stacksize = AST_STACKSIZE;
	errno = pthread_attr_setstacksize(attr, stacksize);
	if (errno)
		ast_log(LOG_WARNING, "pthread_attr_setstacksize returned non-zero: %s\n", strerror(errno));
	a = ast_malloc(sizeof(*a));
	if (!a)
		ast_log(LOG_WARNING, "no memory, thread %s will not be listed\n", start_fn);
	else {	/* remap parameters */
		a->start_routine = start_routine;
		a->data = data;
		start_routine = dummy_start;
		asprintf(&a->name, "%-20s started at [%5d] %s %s()",
			start_fn, line, file, caller);
		data = a;
	}
	return pthread_create(thread, attr, start_routine, data); /* We're in ast_pthread_create, so it's okay */
}

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 poll(pfd, 1, ms);
}

int ast_carefulwrite(int fd, char *s, int len, int timeoutms) 
{
	/* Try to write string, but wait no more than ms milliseconds
	   before timing out */
	int res = 0;
	struct pollfd fds[1];
	while (len) {
		res = write(fd, s, len);
		if ((res < 0) && (errno != EAGAIN)) {
			return -1;
		}
		if (res < 0)
			res = 0;
		len -= res;
		s += res;
		res = 0;
		if (len) {
			fds[0].fd = fd;
			fds[0].events = POLLOUT;
			/* Wait until writable again */
			res = poll(fds, 1, timeoutms);
			if (res < 1)
				return -1;
		}
	}
	return res;
}

char *ast_strip_quoted(char *s, const char *beg_quotes, const char *end_quotes)
{
	char *e;
	char *q;

	s = ast_strip(s);
	if ((q = strchr(beg_quotes, *s))) {
		e = s + strlen(s) - 1;
		if (*e == *(end_quotes + (q - beg_quotes))) {
			s++;
			*e = '\0';
		}
	}

	return s;
}

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_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",
			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",
			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;
}
#undef ONE_MILLION

#ifndef HAVE_STRCASESTR
static char *upper(const char *orig, char *buf, int bufsize)
{
	int i = 0;

	while (i < (bufsize - 1) && orig[i]) {
		buf[i] = toupper(orig[i]);
		i++;
	}

	buf[i] = '\0';

	return buf;
}

char *strcasestr(const char *haystack, const char *needle)
{
	char *u1, *u2;
	int u1len = strlen(haystack) + 1, u2len = strlen(needle) + 1;

	u1 = alloca(u1len);
	u2 = alloca(u2len);
	if (u1 && u2) {
		char *offset;
		if (u2len > u1len) {
			/* Needle bigger than haystack */
			return NULL;
		}
		offset = strstr(upper(haystack, u1, u1len), upper(needle, u2, u2len));
		if (offset) {
			/* Return the offset into the original string */
			return ((char *)((unsigned long)haystack + (unsigned long)(offset - u1)));
		} else {
			return NULL;
		}
	} else {
		ast_log(LOG_ERROR, "Out of memory\n");
		return NULL;
	}
}
#endif /* !HAVE_STRCASESTR */

#ifndef HAVE_STRNLEN
size_t strnlen(const char *s, size_t n)
{
	size_t len;

	for (len=0; len < n; len++)
		if (s[len] == '\0')
			break;

	return len;
}
#endif /* !HAVE_STRNLEN */

#if !defined(HAVE_STRNDUP) && !defined(__AST_DEBUG_MALLOC)
char *strndup(const char *s, size_t n)
{
	size_t len = strnlen(s, n);
	char *new = ast_malloc(len + 1);

	if (!new)
		return NULL;

	new[len] = '\0';
	return memcpy(new, s, len);
}
#endif /* !defined(HAVE_STRNDUP) && !defined(__AST_DEBUG_MALLOC) */

#if !defined(HAVE_VASPRINTF) && !defined(__AST_DEBUG_MALLOC)
int vasprintf(char **strp, const char *fmt, va_list ap)
{
	int size;
	va_list ap2;
	char s;

	*strp = NULL;
	va_copy(ap2, ap);
	size = vsnprintf(&s, 1, fmt, ap2);
	va_end(ap2);
	*strp = ast_malloc(size + 1);
	if (!*strp)
		return -1;
	vsnprintf(*strp, size + 1, fmt, ap);

	return size;
}
#endif /* !defined(HAVE_VASPRINTF) && !defined(__AST_DEBUG_MALLOC) */

/*
 * Based on Code from bsd-asprintf from OpenSSH
 * Copyright (c) 2004 Darren Tucker.
 *
 * Based originally on asprintf.c from OpenBSD:
 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#if !defined(HAVE_ASPRINTF) && !defined(__AST_DEBUG_MALLOC) 
int asprintf(char **str, const char *fmt, ...)
{
        va_list ap;
        int ret;

        *str = NULL;
        va_start(ap, fmt);
        ret = vasprintf(str, fmt, ap);
        va_end(ap);

        return ret;
}
#endif /* !defined(HAVE_ASPRINTF) && !defined(__AST_DEBUG_MALLOC) */

#ifndef HAVE_STRTOQ
#ifndef LONG_MIN
#define LONG_MIN        (-9223372036854775807L-1L)
	                                 /* min value of a "long int" */
#endif
#ifndef LONG_MAX
#define LONG_MAX        9223372036854775807L
	                                 /* max value of a "long int" */
#endif

/*! \brief
 * Convert a string to a quad integer.
 *
 * \note Ignores `locale' stuff.  Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
uint64_t strtoq(const char *nptr, char **endptr, int base)
{
	 const char *s;
	 uint64_t acc;
	 unsigned char c;
	 uint64_t qbase, cutoff;
	 int neg, any, cutlim;

	 /*
	  * Skip white space and pick up leading +/- sign if any.
	  * If base is 0, allow 0x for hex and 0 for octal, else
	  * assume decimal; if base is already 16, allow 0x.
	  */
	 s = nptr;
	 do {
	         c = *s++;
	 } while (isspace(c));
	 if (c == '-') {
	         neg = 1;
	         c = *s++;
	 } else {
	         neg = 0;
	         if (c == '+')
	                 c = *s++;
	 }
	 if ((base == 0 || base == 16) &&
	     c == '\0' && (*s == 'x' || *s == 'X')) {
	         c = s[1];
	         s += 2;
	         base = 16;
	 }
	 if (base == 0)
	         base = c == '\0' ? 8 : 10;

	 /*
	  * Compute the cutoff value between legal numbers and illegal
	  * numbers.  That is the largest legal value, divided by the
	  * base.  An input number that is greater than this value, if
	  * followed by a legal input character, is too big.  One that
	  * is equal to this value may be valid or not; the limit
	  * between valid and invalid numbers is then based on the last
	  * digit.  For instance, if the range for quads is
	  * [-9223372036854775808..9223372036854775807] and the input base
	  * is 10, cutoff will be set to 922337203685477580 and cutlim to
	  * either 7 (neg==0) or 8 (neg==1), meaning that if we have
	  * accumulated a value > 922337203685477580, or equal but the
	  * next digit is > 7 (or 8), the number is too big, and we will
	  * return a range error.
	  *
	  * Set any if any `digits' consumed; make it negative to indicate
	  * overflow.
	  */
	 qbase = (unsigned)base;
	 cutoff = neg ? (uint64_t)-(LONG_MIN + LONG_MAX) + LONG_MAX : LONG_MAX;
	 cutlim = cutoff % qbase;
	 cutoff /= qbase;
	 for (acc = 0, any = 0;; c = *s++) {
	         if (!isascii(c))
	                 break;
	         if (isdigit(c))
	                 c -= '\0';
	         else if (isalpha(c))
	                 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
	         else
	                 break;
	         if (c >= base)
	                 break;
	         if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
	                 any = -1;
	         else {
	                 any = 1;
	                 acc *= qbase;
	                 acc += c;
	         }
	 }
	 if (any < 0) {
	         acc = neg ? LONG_MIN : LONG_MAX;
	 } else if (neg)
	         acc = -acc;
	 if (endptr != 0)
	         *((const char **)endptr) = any ? s - 1 : nptr;
	 return acc;
}
#endif /* !HAVE_STRTOQ */

#ifndef HAVE_GETLOADAVG
#ifdef linux
/*! \brief Alternative method of getting load avg on Linux only */
int getloadavg(double *list, int nelem)
{
	FILE *LOADAVG;
	double avg[3] = { 0.0, 0.0, 0.0 };
	int i, res = -1;

	if ((LOADAVG = fopen("/proc/loadavg", "r"))) {
		fscanf(LOADAVG, "%lf %lf %lf", &avg[0], &avg[1], &avg[2]);
		res = 0;
		fclose(LOADAVG);
	}

	for (i = 0; (i < nelem) && (i < 3); i++) {
		list[i] = avg[i];
	}

	return res;
}
#else /* !linux */
/*! \brief Return something that won't cancel the call, but still return -1, in case
 * we correct the implementation to check return value */
int getloadavg(double *list, int nelem)
{
	int i;

	for (i = 0; i < nelem; i++) {
		list[i] = 0.1;
	}
	return -1;
}
#endif /* linux */
#endif /* !defined(_BSD_SOURCE) */

/*! \brief glibc puts a lock inside random(3), so that the results are thread-safe.
 * BSD libc (and others) do not. */
#ifndef linux

AST_MUTEX_DEFINE_STATIC(randomlock);

long int ast_random(void)
{
	long int res;
	ast_mutex_lock(&randomlock);
	res = random();
	ast_mutex_unlock(&randomlock);
	return res;
}
#endif

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(char *s, size_t len, char * const w[])
{
	int x, ofs = 0;
	const char *src;

	/* Join words into a string */
	if (!s)
		return;
	for (x=0; ofs < len && w[x]; x++) {
		if (x > 0)
			s[ofs++] = ' ';
		for (src = w[x]; *src && ofs < len; src++)
			s[ofs++] = *src;
	}
	if (ofs == len)
		ofs--;
	s[ofs] = '\0';
}

const char __ast_string_field_empty[] = "";

static int add_string_pool(struct ast_string_field_mgr *mgr, size_t size)
{
	struct ast_string_field_pool *pool;

	if (!(pool = ast_calloc(1, sizeof(*pool) + size)))
		return -1;
	
	pool->prev = mgr->pool;
	mgr->pool = pool;
	mgr->size = size;
	mgr->space = size;
	mgr->used = 0;

	return 0;
}

int __ast_string_field_init(struct ast_string_field_mgr *mgr, size_t size,
			    ast_string_field *fields, int num_fields)
{
	int index;

	if (add_string_pool(mgr, size))
		return -1;

	for (index = 0; index < num_fields; index++)
		fields[index] = __ast_string_field_empty;

	return 0;
}

ast_string_field __ast_string_field_alloc_space(struct ast_string_field_mgr *mgr, size_t needed,
						ast_string_field *fields, int num_fields)
{
	char *result = NULL;

	if (__builtin_expect(needed > mgr->space, 0)) {
		size_t new_size = mgr->size * 2;

		while (new_size < needed)
			new_size *= 2;

		if (add_string_pool(mgr, new_size))
			return NULL;
	}

	result = mgr->pool->base + mgr->used;
	mgr->used += needed;
	mgr->space -= needed;
	return result;
}

void __ast_string_field_index_build(struct ast_string_field_mgr *mgr,
				    ast_string_field *fields, int num_fields,
				    int index, const char *format, ...)
{
	size_t needed;
	va_list ap1, ap2;

	va_start(ap1, format);
	va_start(ap2, format);		/* va_copy does not exist on FreeBSD */

	needed = vsnprintf(mgr->pool->base + mgr->used, mgr->space, format, ap1) + 1;

	va_end(ap1);

	if (needed > mgr->space) {
		size_t new_size = mgr->size * 2;

		while (new_size < needed)
			new_size *= 2;

		if (add_string_pool(mgr, new_size))
			return;

		vsprintf(mgr->pool->base + mgr->used, format, ap2);
	}

	fields[index] = mgr->pool->base + mgr->used;
	mgr->used += needed;
	mgr->space -= needed;

	va_end(ap2);
}

AST_MUTEX_DEFINE_STATIC(fetchadd_m); /* used for all fetc&add ops */
int ast_atomic_fetchadd_int_slow(volatile int *p, int v)
{
        int ret;
        ast_mutex_lock(&fetchadd_m);
        ret = *p;
        *p += v;
        ast_mutex_unlock(&fetchadd_m);
        return ret;
}

/*! \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, "%ld%n", &t, &scanned) == 1) {
		*dst = t;
		if (consumed)
			*consumed = scanned;
		return 0;
	} else
		return -1;
}