/** * @file port.h * @note Copyright (C) 2011 Richard Cochran * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef HAVE_PORT_H #define HAVE_PORT_H #include "dm.h" #include "fd.h" #include "foreign.h" #include "fsm.h" #include "transport.h" /* forward declarations */ struct interface; struct clock; /** Opaque type. */ struct port; /** * Returns the dataset from a port's best foreign clock record, if any * has yet been discovered. This function does not bring the returned * dataset up to date, so the caller should invoke port_compute_best() * beforehand. * * @param port A pointer previously obtained via port_open(). * @return A pointer to a dataset, or NULL. */ struct dataset *port_best_foreign(struct port *port); /** * Close a port and free its associated resources. After this call * returns, @a port is no longer a valid port instance. * * @param port A pointer previously obtained via port_open(). */ void port_close(struct port *port); /** * Computes the 'best' foreign master discovered on a port. This has * the side effect of updating the 'dataset' field of the returned * foreign master. * * @param port A pointer previously obtained via port_open(). * @return A pointer to the port's best foreign master, or NULL. */ struct foreign_clock *port_compute_best(struct port *port); /** * Dispatch a port event. This may cause a state transition on the * port, with the associated side effect. * * @param port A pointer previously obtained via port_open(). * @param event One of the @a fsm_event codes. * @param mdiff Whether a new master has been selected. * @return Zero if the port's file descriptor array is still valid, * and non-zero if it has become invalid. */ int port_dispatch(struct port *p, enum fsm_event event, int mdiff); /** * Generates state machine events based on activity on a port's file * descriptors. * * @param port A pointer previously obtained via port_open(). * @param fd_index The index of the active file descriptor. * @return One of the @a fsm_event codes. */ enum fsm_event port_event(struct port *port, int fd_index); /** * Forward a message on a given port. * @param port A pointer previously obtained via port_open(). * @param msg The message to send. Must be in network byte order. * @param msglen The length of the message in bytes. * @return Zero on success, non-zero otherwise. */ int port_forward(struct port *p, struct ptp_message *msg, int msglen); /** * Obtain a port's identity. * @param p A pointer previously obtained via port_open(). * @return The port identity of 'p'. */ struct PortIdentity port_identity(struct port *p); /** * Manage a port according to a given message. * @param p A pointer previously obtained via port_open(). * @param ingress The port on which 'msg' was received. * @param msg A management message. * @return Zero if the message is valid, non-zero otherwise. */ int port_manage(struct port *p, struct port *ingress, struct ptp_message *msg); /** * Send a management error status message. * @param pid The id of the responding port. * @param ingress Port on which the 'req' was received. * @param req The management message which triggered the error. * @param error_id One of the management error ID values. * @return Zero on success, non-zero otherwise. */ int port_management_error(struct PortIdentity pid, struct port *ingress, struct ptp_message *req, Enumeration16 error_id); /** * Allocate a reply to a management message. * * Messages are reference counted, and newly allocated messages have a * reference count of one. Allocated messages are freed using the * function @ref msg_put(). * * @param pid The id of the responding port. * @param ingress The port on which 'req' was received. * @param req A management message. * @return Pointer to a message on success, NULL otherwise. */ struct ptp_message *port_management_reply(struct PortIdentity pid, struct port *ingress, struct ptp_message *req); /** * Open a network port. * @param phc_index The PHC device index for the network device. * @param timestamping The timestamping mode for this port. * @param number An arbitrary number assigned to this port. * @param interface The interface data * @param clock A pointer to the system PTP clock. * @return A pointer to an open port on success, or NULL otherwise. */ struct port *port_open(int phc_index, enum timestamp_type timestamping, int number, struct interface *interface, struct clock *clock); /** * Returns a port's current state. * @param port A port instance. * @return One of the @ref port_state values. */ enum port_state port_state(struct port *port); /** * Utility function for setting or resetting a file descriptor timer. * * This function sets the timer 'fd' to the value M(2^N), where M is * the value of the 'scale' parameter and N in the value of the * 'log_seconds' parameter. * * Passing both 'scale' and 'log_seconds' as zero disables the timer. * * @param fd A file descriptor previously opened with timerfd_create(2). * @param scale The multiplicative factor for the timer. * @param log_seconds The exponential factor for the timer. * @return Zero on success, non-zero otherwise. */ int set_tmo(int fd, unsigned int scale, int log_seconds); #endif