Function NgRecvData

tools/libnetgraph/sock.c:219–251

* Read a packet from a data socket * Returns -1 if error and sets errno. */

 * Returns -1 if error and sets errno.
 */
int
NgRecvData(int ds, u_char * buf, size_t len, char *hook)
{
	u_char frombuf[NG_HOOKSIZ + NGSA_OVERHEAD];
	struct sockaddr_ng *const from = (struct sockaddr_ng *) frombuf;
	socklen_t fromlen = sizeof(frombuf);
	int rtn, errnosv;

	/* Read packet */
	rtn = recvfrom(ds, buf, len, 0, (struct sockaddr *) from, &fromlen);
	if (rtn < 0) {
		errnosv = errno;
		if (_gNgDebugLevel >= 1)
			NGLOG("recvfrom");
		errno = errnosv;
		return (-1);
	}

	/* Copy hook name */
	if (hook != NULL)
		strlcpy(hook, from->sg_data, NG_HOOKSIZ);

	/* Debugging */
	if (_gNgDebugLevel >= 2) {
		NGLOGX("READ %s from hook \"%s\" (%d bytes)",
		       rtn ? "PACKET" : "EOF", from->sg_data, rtn);
		if (_gNgDebugLevel >= 3)
			_NgDebugBytes(buf, rtn);
	}

	/* Done */
	return (rtn);
}

/*
 * Identical to NgRecvData() except buffer is dynamically allocated.