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 ast_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 = ast_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.
 */

/* this is a little complex... string fields are stored with their
   allocated size in the bytes preceding the string; even the
   constant 'empty' string has to be this way, so the code that
   checks to see if there is enough room for a new string doesn't
   have to have any special case checks
*/

static const struct {
	ast_string_field_allocation allocation;
	char string[1];
} __ast_string_field_empty_buffer;

ast_string_field __ast_string_field_empty = __ast_string_field_empty_buffer.string;

#define ALLOCATOR_OVERHEAD 48

static size_t optimal_alloc_size(size_t size)
{
	unsigned int count;

	size += ALLOCATOR_OVERHEAD;

	for (count = 1; size; size >>= 1, count++);

	return (1 << count) - ALLOCATOR_OVERHEAD;
}

/*! \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;
	size_t alloc_size = optimal_alloc_size(sizeof(*pool) + size);

	if (!(pool = ast_calloc(1, alloc_size))) {
		return -1;
	}

	pool->prev = *pool_head;
	pool->size = alloc_size - sizeof(*pool);
	*pool_head = pool;
	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;
		(*pool_head)->used = (*pool_head)->active = 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 = (*pool_head)->size - (*pool_head)->used;
	size_t to_alloc = needed + sizeof(ast_string_field_allocation);

	if (__builtin_expect(to_alloc > space, 0)) {
		size_t new_size = (*pool_head)->size;

		while (new_size < to_alloc) {
			new_size *= 2;
		}

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

	result = (*pool_head)->base + (*pool_head)->used;
	(*pool_head)->used += to_alloc;
	(*pool_head)->active += needed;
	result += sizeof(ast_string_field_allocation);
	AST_STRING_FIELD_ALLOCATION(result) = needed;
	mgr->last_alloc = result;

	return result;
}

int __ast_string_field_ptr_grow(struct ast_string_field_mgr *mgr,
				struct ast_string_field_pool **pool_head, size_t needed,
				const ast_string_field *ptr)
{
	ssize_t grow = needed - AST_STRING_FIELD_ALLOCATION(*ptr);
	size_t space = (*pool_head)->size - (*pool_head)->used;

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

	if (space < grow) {
		return 1;
	}

	(*pool_head)->used += grow;
	(*pool_head)->active += grow;
	AST_STRING_FIELD_ALLOCATION(*ptr) += grow;

	return 0;
}

void __ast_string_field_release_active(struct ast_string_field_pool *pool_head,
				       const ast_string_field ptr)
{
	struct ast_string_field_pool *pool, *prev;

	if (ptr == __ast_string_field_empty) {
		return;
	}

	for (pool = pool_head, prev = NULL; pool; prev = pool, pool = pool->prev) {
		if ((ptr >= pool->base) && (ptr <= (pool->base + pool->size))) {
			pool->active -= AST_STRING_FIELD_ALLOCATION(ptr);
			if ((pool->active == 0) && prev) {
				prev->prev = pool->prev;
				ast_free(pool);
			}
			break;
		}
	}
}

void __ast_string_field_ptr_build_va(struct ast_string_field_mgr *mgr,
				     struct ast_string_field_pool **pool_head,
				     ast_string_field *ptr, const char *format, va_list ap1, va_list ap2)
{
	size_t needed;
	size_t available;
	size_t space = (*pool_head)->size - (*pool_head)->used;
	ssize_t grow;
	char *target;

	/* if the field already has space allocated, try to reuse it;
	   otherwise, try to use the empty space at the end of the current
	   pool
	*/
	if (*ptr != __ast_string_field_empty) {
		target = (char *) *ptr;
		available = AST_STRING_FIELD_ALLOCATION(*ptr);
		if (*ptr == mgr->last_alloc) {
			available += space;
		}
	} else {
		target = (*pool_head)->base + (*pool_head)->used + sizeof(ast_string_field_allocation);
		available = space - sizeof(ast_string_field_allocation);
	}

	needed = vsnprintf(target, available, format, ap1) + 1;

	va_end(ap1);

	if (needed > available) {
		/* the allocation could not be satisfied using the field's current allocation
		   (if it has one), or the space available in the pool (if it does not). allocate
		   space for it, adding a new string pool if necessary.
		*/
		if (!(target = (char *) __ast_string_field_alloc_space(mgr, pool_head, needed))) {
			return;
		}
		vsprintf(target, format, ap2);
		__ast_string_field_release_active(*pool_head, *ptr);
		*ptr = target;
	} else if (*ptr != target) {
		/* the allocation was satisfied using available space in the pool, but not
		   using the space already allocated to the field
		*/
		__ast_string_field_release_active(*pool_head, *ptr);
		mgr->last_alloc = *ptr = target;
		AST_STRING_FIELD_ALLOCATION(target) = needed;
		(*pool_head)->used += needed + sizeof(ast_string_field_allocation);
		(*pool_head)->active += needed;
	} else if ((grow = (needed - AST_STRING_FIELD_ALLOCATION(*ptr))) > 0) {
		/* the allocation was satisfied by using available space in the pool *and*
		   the field was the last allocated field from the pool, so it grew
		*/
		(*pool_head)->used += grow;
		(*pool_head)->active += grow;
		AST_STRING_FIELD_ALLOCATION(*ptr) += grow;
	}
}

void __ast_string_field_ptr_build(struct ast_string_field_mgr *mgr,
				  struct ast_string_field_pool **pool_head,
				  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