utils.c

	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 (asprintf(&a->name, "%-20s started at [%5d] %s %s()",
			     start_fn, line, file, caller) < 0) {
			ast_log(LOG_WARNING, "asprintf() failed: %s\n", strerror(errno));
			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 = 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 poll(pfd, 1, ms);
}

static int ast_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 = poll(&pfd, 1, timeoutms - elapsed)) <= 0) {
		if (res == 0) {
			/* timed out. */
			ast_log(LOG_NOTICE, "Timed out trying to write\n");
			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 (ast_wait_for_output(fd, timeoutms - elapsed)) {
			return -1;
		}

		res = write(fd, s, len);

		if (res < 0 && errno != EAGAIN && errno != EINTR) {
			/* fatal error from write() */
			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;
}

int ast_careful_fwrite(FILE *f, int fd, const char *src, size_t len, int timeoutms)
{
	struct timeval start = ast_tvnow();
	int n = 0;
	int elapsed = 0;

	while (len) {
		if (ast_wait_for_output(fd, timeoutms - elapsed)) {
			/* poll returned a fatal error, so bail out immediately. */
			return -1;
		}

		/* Clear any errors from a previous write */
		clearerr(f);

		n = fwrite(src, 1, len, f);

		if (ferror(f) && errno != EINTR && errno != EAGAIN) {
			/* fatal error from fwrite() */
			if (!feof(f)) {
				/* Don't spam the logs if it was just that the connection is closed. */
				ast_log(LOG_ERROR, "fwrite() returned error: %s\n", strerror(errno));
			}
			n = -1;
			break;
		}

		/* Update for data already written to the socket */
		len -= n;
		src += n;

		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. */
			n = len ? -1 : 0;
			break;
		}
	}

	while (fflush(f)) {
		if (errno == EAGAIN || errno == EINTR) {
			continue;
		}
		if (!feof(f)) {
			/* Don't spam the logs if it was just that the connection is closed. */
			ast_log(LOG_ERROR, "fflush() returned error: %s\n", strerror(errno));
		}
		n = -1;
		break;
	}

	return n < 0 ? -1 : 0;
}

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

	return s;
}

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;
}

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",
			(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;
}
#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) {
			long int rm = RAND_MAX;
			res = res < 0 ? ~res : res;
			rm++;
			return res % rm;
		}
	}
#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';
}

/*
 * stringfields support routines.
 */

const char __ast_string_field_empty[] = ""; /*!< the empty string */

/*! \brief add a new block to the pool.
 * We can only allocate from the topmost pool, so the
 * fields in *mgr reflect the size of that only.
 */
static int add_string_pool(struct ast_string_field_mgr *mgr,
			   struct ast_string_field_pool **pool_head,
			   size_t size)
{
	struct ast_string_field_pool *pool;

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

	return 0;
}

/*
 * This is an internal API, code should not use it directly.
 * It initializes all fields as empty, then uses 'size' for 3 functions:
 * size > 0 means initialize the pool list with a pool of given size.
 *	This must be called right after allocating the object.
 * size = 0 means release all pools except the most recent one.
 *	This is useful to e.g. reset an object to the initial value.
 * size < 0 means release all pools.
 *	This must be done before destroying the object.
 */
int __ast_string_field_init(struct ast_string_field_mgr *mgr,
			    struct ast_string_field_pool **pool_head,
			    int size)
{
	const char **p = (const char **) pool_head + 1;
	struct ast_string_field_pool *cur = *pool_head;

	/* clear fields - this is always necessary */
	while ((struct ast_string_field_mgr *) p != mgr)
		*p++ = __ast_string_field_empty;
	mgr->last_alloc = NULL;
	if (size > 0) {			/* allocate the initial pool */
		*pool_head = NULL;
		return add_string_pool(mgr, pool_head, size);
	}
	if (size < 0) {			/* reset all pools */
		*pool_head = NULL;
	} else {			/* preserve the first pool */
		if (cur == NULL) {
			ast_log(LOG_WARNING, "trying to reset empty pool\n");
			return -1;
		}
		cur = cur->prev;
		(*pool_head)->prev = NULL;
		mgr->used = 0;
	}

	while (cur) {
		struct ast_string_field_pool *prev = cur->prev;

		ast_free(cur);
		cur = prev;
	}

	return 0;
}

ast_string_field __ast_string_field_alloc_space(struct ast_string_field_mgr *mgr,
						struct ast_string_field_pool **pool_head, size_t needed)
{
	char *result = NULL;
	size_t space = mgr->size - mgr->used;

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

		while (new_size < needed)
			new_size *= 2;

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

	result = (*pool_head)->base + mgr->used;
	mgr->used += needed;
	mgr->last_alloc = result;
	return result;
}

int __ast_string_field_ptr_grow(struct ast_string_field_mgr *mgr, size_t needed,
				const ast_string_field *ptr)
{
	int grow = needed - (strlen(*ptr) + 1);
	size_t space = mgr->size - mgr->used;

	if (grow <= 0) {
		return 0;
	}

	if (*ptr != mgr->last_alloc) {
		return 1;
	}

	if (space < grow) {
		return 1;
	}

	mgr->used += grow;

	return 0;
}

void __ast_string_field_ptr_build_va(struct ast_string_field_mgr *mgr,
				     struct ast_string_field_pool **pool_head,
				     const ast_string_field *ptr, const char *format, va_list ap1, va_list ap2)
{
	size_t needed;
	char *dst = (*pool_head)->base + mgr->used;
	const char **p = (const char **) ptr;
	size_t space = mgr->size - mgr->used;

	/* try to write using available space */
	needed = vsnprintf(dst, space, format, ap1) + 1;

	va_end(ap1);

	if (needed > space) {	/* if it fails, reallocate */
		size_t new_size = mgr->size * 2;

		while (new_size < needed)
			new_size *= 2;

		if (add_string_pool(mgr, pool_head, new_size))
			return;

		dst = (*pool_head)->base + mgr->used;
		vsprintf(dst, format, ap2);
	}

	mgr->last_alloc = *p = dst;
	mgr->used += needed;
}

void __ast_string_field_ptr_build(struct ast_string_field_mgr *mgr,
				  struct ast_string_field_pool **pool_head,
				  const ast_string_field *ptr, 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_ptr_build_va(mgr, pool_head, ptr, format, ap1, ap2);

	va_end(ap1);
	va_end(ap2);
}
/* end of stringfields support */

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;
}

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
#if !defined(LOW_MEMORY)
	ast_cli_register_multiple(utils_cli, ARRAY_LEN(utils_cli));
#endif
#endif
	return 0;
}

#ifndef __AST_DEBUG_MALLOC
int _ast_asprintf(char **ret, const char *file, int lineno, const char *func, const char *fmt, ...)
{
	int res;
	va_list ap;

	va_start(ap, fmt);
	if ((res = vasprintf(ret, fmt, ap)) == -1) {
		MALLOC_FAILURE_MSG;
	}
	va_end(ap);

	return res;
}
#endif