utils.c

			memmove(e - 1, e, strlen(e) + 1);
			work = e;
		}
	}

	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

/*! \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);
#endif

long int ast_random(void)
{
	long int res;
#ifdef HAVE_DEV_URANDOM
	if (dev_urandom_fd >= 0) {
		int read_res = read(dev_urandom_fd, &res, sizeof(res));
		if (read_res > 0)
			return labs(res);
	}
#endif
#ifdef linux
	res = random();
#else
	ast_mutex_lock(&randomlock);
	res = random();
	ast_mutex_unlock(&randomlock);
#endif
	return res;
}

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

	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;
}

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

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

	__ast_string_field_index_build_va(mgr, fields, num_fields, index, format, ap1, ap2);

	va_end(ap1);
	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_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, "%Lf%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, "%ld%n", &t, &scanned) == 1) {
		*dst = t;
		if (consumed)
			*consumed = scanned;
		return 0;
	} else
		return -1;
}

/*!
 * core handler for dynamic strings.
 * This is not meant to be called directly, but rather through the
 * various wrapper macros
 *	ast_str_set(...)
 *	ast_str_append(...)
 *	ast_str_set_va(...)
 *	ast_str_append_va(...)
 */
int __ast_str_helper(struct ast_str **buf, size_t max_len,
	int append, const char *fmt, va_list ap)
{
	int res, need;
	int offset = (append && (*buf)->len) ? (*buf)->used : 0;

	if (max_len < 0)
		max_len = (*buf)->len;	/* don't exceed the allocated space */
	/*
	 * Ask vsnprintf how much space we need. Remember that vsnprintf
	 * does not count the final '\0' so we must add 1.
	 */
	res = vsnprintf((*buf)->str + offset, (*buf)->len - offset, fmt, ap);

	need = res + offset + 1;
	/*
	 * If there is not enough space and we are below the max length,
	 * reallocate the buffer and return a message telling to retry.
	 */
	if (need > (*buf)->len && (max_len == 0 || (*buf)->len < max_len) ) {
		if (max_len && max_len < need)	/* truncate as needed */
			need = max_len;
		else if (max_len == 0)	/* if unbounded, give more room for next time */
			need += 16 + need/4;
		if (0)	/* debugging */
			ast_verbose("extend from %d to %d\n", (int)(*buf)->len, need);
		if (ast_str_make_space(buf, need)) {
			ast_verbose("failed to extend from %d to %d\n", (int)(*buf)->len, need);
			return AST_DYNSTR_BUILD_FAILED;
		}
		(*buf)->str[offset] = '\0';	/* Truncate the partial write. */

		/* va_end() and va_start() must be done before calling
		 * vsnprintf() again. */
		return AST_DYNSTR_BUILD_RETRY;
	}
	/* update space used, keep in mind the truncation */
	(*buf)->used = (res + offset > (*buf)->len) ? (*buf)->len : res + offset;

	return res;
}

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 = alloca(len + 1);
	int res = 0;

	for (ptr = tmp; *ptr; ptr++) {
		if (*ptr == '/')
			count++;
	}

	/* Count the components to the directory path */
	pieces = 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;
}

int ast_utils_init(void)
{
#ifdef HAVE_DEV_URANDOM
	dev_urandom_fd = open("/dev/urandom", O_RDONLY);
#endif
	base64_init();
#ifdef DEBUG_THREADS
	ast_cli_register_multiple(utils_cli, sizeof(utils_cli) / sizeof(utils_cli[0]));
#endif
	return 0;
}