badvpn/system/BDatagram.h
2020-02-01 15:02:11 -08:00

234 lines
7.6 KiB
C

/**
* @file BDatagram.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef BADVPN_SYSTEM_BDATAGRAM
#define BADVPN_SYSTEM_BDATAGRAM
#include <misc/debug.h>
#include <flow/PacketPassInterface.h>
#include <flow/PacketRecvInterface.h>
#include <system/BAddr.h>
#include <system/BReactor.h>
#include <system/BNetwork.h>
struct BDatagram_s;
/**
* Represents datagram communication. This is usually UDP, but may also be Linux packet sockets.
* Sending and receiving is performed via {@link PacketPassInterface} and {@link PacketRecvInterface},
* respectively.
*/
typedef struct BDatagram_s BDatagram;
#define BDATAGRAM_EVENT_ERROR 1
/**
* Handler called when an error occurs with the datagram object.
* The datagram object is no longer usable and must be freed from withing the job closure of
* this handler. No further I/O, interface initialization, binding and send address setting
* must occur.
*
* @param user as in {@link BDatagram_Init}
* @param event always BDATAGRAM_EVENT_ERROR
*/
typedef void (*BDatagram_handler) (void *user, int event);
/**
* Checks if the given address family (from {@link BAddr.h}) is supported by {@link BDatagram}
* and related objects.
*
* @param family family to check
* @return 1 if supported, 0 if not
*/
int BDatagram_AddressFamilySupported (int family);
/**
* Initializes the object.
* {@link BNetwork_GlobalInit} must have been done.
*
* @param o the object
* @param family address family. Must be supported according to {@link BDatagram_AddressFamilySupported}.
* @param reactor reactor we live in
* @param user argument to handler
* @param handler handler called when an error occurs
* @return 1 on success, 0 on failure
*/
int BDatagram_Init (BDatagram *o, int family, BReactor *reactor, void *user,
BDatagram_handler handler) WARN_UNUSED;
/**
* Frees the object.
* The send and receive interfaces must not be initialized.
*
* @param o the object
*/
void BDatagram_Free (BDatagram *o);
/**
* Binds to the given local address.
* May initiate I/O.
*
* @param o the object
* @param addr address to bind to. Its family must be supported according to {@link BDatagram_AddressFamilySupported}.
* @return 1 on success, 0 on failure
*/
int BDatagram_Bind (BDatagram *o, BAddr addr) WARN_UNUSED;
/**
* Sets addresses for sending.
* May initiate I/O.
*
* @param o the object
* @param remote_addr destination address for sending datagrams. Its family must be supported according
* to {@link BDatagram_AddressFamilySupported}.
* @param local_addr local source IP address. May be an invalid address, otherwise its family must be
* supported according to {@link BDatagram_AddressFamilySupported}.
*/
void BDatagram_SetSendAddrs (BDatagram *o, BAddr remote_addr, BIPAddr local_addr);
/**
* Returns the remote and local address of the last datagram received.
* Fails if and only if no datagrams have been received yet.
*
* @param o the object
* @param remote_addr returns the remote source address of the datagram. May be an invalid address, theoretically.
* @param local_addr returns the local destination IP address. May be an invalid address.
* @return 1 on success, 0 on failure
*/
int BDatagram_GetLastReceiveAddrs (BDatagram *o, BAddr *remote_addr, BIPAddr *local_addr);
/**
* Determines the local address.
*
* This calls getsockname() to determine the local address and returns the result as
* BAddr. This function fails if the address cannot be determined or translated to
* BAddr (it never succeeds but returns a BADDR_TYPE_NONE address).
*
* @param o the object
* @param local_addr returns the local bound address.
* @return 1 on success, 0 on failure
*/
int BDatagram_GetLocalAddr (BDatagram *o, BAddr *local_addr);
/**
* Returns the local port.
*
* This is a convenience function implemented based on BDatagram_GetLocalAddr.
*
* @param o the object
* @param local_port returns the local bound port.
* @return 1 on success, 0 on failure
*/
int BDatagram_GetLocalPort (BDatagram *o, uint16_t *local_port);
#ifndef BADVPN_USE_WINAPI
/**
* Returns the underlying socket file descriptor of the datagram object.
* Available on Unix-like systems only.
*
* @param o the object
* @return file descriptor
*/
int BDatagram_GetFd (BDatagram *o);
#endif
/**
* Sets the SO_REUSEADDR option for the underlying socket.
*
* @param o the object
* @param reuse value of the option. Must be 0 or 1.
*/
int BDatagram_SetReuseAddr (BDatagram *o, int reuse);
/**
* Initializes the send interface.
* The send interface must not be initialized.
*
* @param o the object
* @param mtu maximum transmission unit. Must be >=0.
*/
void BDatagram_SendAsync_Init (BDatagram *o, int mtu);
/**
* Frees the send interface.
* The send interface must be initialized.
* If the send interface was busy when this is called, the datagram object is no longer usable and must be
* freed before any further I/O or interface initialization.
*
* @param o the object
*/
void BDatagram_SendAsync_Free (BDatagram *o);
/**
* Returns the send interface.
* The send interface must be initialized.
* The MTU of the interface will be as in {@link BDatagram_SendAsync_Init}.
*
* @param o the object
* @return send interface
*/
PacketPassInterface * BDatagram_SendAsync_GetIf (BDatagram *o);
/**
* Initializes the receive interface.
* The receive interface must not be initialized.
*
* @param o the object
* @param mtu maximum transmission unit. Must be >=0.
*/
void BDatagram_RecvAsync_Init (BDatagram *o, int mtu);
/**
* Frees the receive interface.
* The receive interface must be initialized.
* If the receive interface was busy when this is called, the datagram object is no longer usable and must be
* freed before any further I/O or interface initialization.
*
* @param o the object
*/
void BDatagram_RecvAsync_Free (BDatagram *o);
/**
* Returns the receive interface.
* The receive interface must be initialized.
* The MTU of the interface will be as in {@link BDatagram_RecvAsync_Init}.
*
* @param o the object
* @return receive interface
*/
PacketRecvInterface * BDatagram_RecvAsync_GetIf (BDatagram *o);
#ifdef BADVPN_USE_WINAPI
#include "BDatagram_win.h"
#else
#include "BDatagram_unix.h"
#endif
#endif