socket.h

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/*
 * Copyright (C) 2004-2006  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: socket.h,v 1.57.18.6 2006/06/07 00:29:45 marka Exp $ */

#ifndef ISC_SOCKET_H
#define ISC_SOCKET_H 1

/*****
 ***** Module Info
 *****/

/*! \file
 * \brief Provides TCP and UDP sockets for network I/O.  The sockets are event
 * sources in the task system.
 *
 * When I/O completes, a completion event for the socket is posted to the
 * event queue of the task which requested the I/O.
 *
 * \li MP:
 *	The module ensures appropriate synchronization of data structures it
 *	creates and manipulates.
 *	Clients of this module must not be holding a socket's task's lock when
 *	making a call that affects that socket.  Failure to follow this rule
 *	can result in deadlock.
 *	The caller must ensure that isc_socketmgr_destroy() is called only
 *	once for a given manager.
 *
 * \li Reliability:
 *	No anticipated impact.
 *
 * \li Resources:
 *	TBS
 *
 * \li Security:
 *	No anticipated impact.
 *
 * \li Standards:
 *	None.
 */

/***
 *** Imports
 ***/

#include <isc/lang.h>
#include <isc/types.h>
#include <isc/event.h>
#include <isc/eventclass.h>
#include <isc/time.h>
#include <isc/region.h>
#include <isc/sockaddr.h>

ISC_LANG_BEGINDECLS

/***
 *** Constants
 ***/

/*%
 * Maximum number of buffers in a scatter/gather read/write.  The operating
 * system in use must support at least this number (plus one on some.)
 */
#define ISC_SOCKET_MAXSCATTERGATHER	8

/***
 *** Types
 ***/

struct isc_socketevent {
	ISC_EVENT_COMMON(isc_socketevent_t);
	isc_result_t		result;		/*%< OK, EOF, whatever else */
	unsigned int		minimum;	/*%< minimum i/o for event */
	unsigned int		n;		/*%< bytes read or written */
	unsigned int		offset;		/*%< offset into buffer list */
	isc_region_t		region;		/*%< for single-buffer i/o */
	isc_bufferlist_t	bufferlist;	/*%< list of buffers */
	isc_sockaddr_t		address;	/*%< source address */
	isc_time_t		timestamp;	/*%< timestamp of packet recv */
	struct in6_pktinfo	pktinfo;	/*%< ipv6 pktinfo */
	isc_uint32_t		attributes;	/*%< see below */
	isc_eventdestructor_t   destroy;	/*%< original destructor */
};

typedef struct isc_socket_newconnev isc_socket_newconnev_t;
struct isc_socket_newconnev {
	ISC_EVENT_COMMON(isc_socket_newconnev_t);
	isc_socket_t *		newsocket;
	isc_result_t		result;		/*%< OK, EOF, whatever else */
	isc_sockaddr_t		address;	/*%< source address */
};

typedef struct isc_socket_connev isc_socket_connev_t;
struct isc_socket_connev {
	ISC_EVENT_COMMON(isc_socket_connev_t);
	isc_result_t		result;		/*%< OK, EOF, whatever else */
};

/*@{*/
/*!
 * _ATTACHED:	Internal use only.
 * _TRUNC:	Packet was truncated on receive.
 * _CTRUNC:	Packet control information was truncated.  This can
 *		indicate that the packet is not complete, even though
 *		all the data is valid.
 * _TIMESTAMP:	The timestamp member is valid.
 * _PKTINFO:	The pktinfo member is valid.
 * _MULTICAST:	The UDP packet was received via a multicast transmission.
 */
#define ISC_SOCKEVENTATTR_ATTACHED		0x80000000U /* internal */
#define ISC_SOCKEVENTATTR_TRUNC			0x00800000U /* public */
#define ISC_SOCKEVENTATTR_CTRUNC		0x00400000U /* public */
#define ISC_SOCKEVENTATTR_TIMESTAMP		0x00200000U /* public */
#define ISC_SOCKEVENTATTR_PKTINFO		0x00100000U /* public */
#define ISC_SOCKEVENTATTR_MULTICAST		0x00080000U /* public */
/*@}*/

#define ISC_SOCKEVENT_ANYEVENT  (0)
#define ISC_SOCKEVENT_RECVDONE	(ISC_EVENTCLASS_SOCKET + 1)
#define ISC_SOCKEVENT_SENDDONE	(ISC_EVENTCLASS_SOCKET + 2)
#define ISC_SOCKEVENT_NEWCONN	(ISC_EVENTCLASS_SOCKET + 3)
#define ISC_SOCKEVENT_CONNECT	(ISC_EVENTCLASS_SOCKET + 4)

/*
 * Internal events.
 */
#define ISC_SOCKEVENT_INTR	(ISC_EVENTCLASS_SOCKET + 256)
#define ISC_SOCKEVENT_INTW	(ISC_EVENTCLASS_SOCKET + 257)

typedef enum {
	isc_sockettype_udp = 1,
	isc_sockettype_tcp = 2,
	isc_sockettype_unix = 3
} isc_sockettype_t;

/*@{*/
/*!
 * How a socket should be shutdown in isc_socket_shutdown() calls.
 */
#define ISC_SOCKSHUT_RECV	0x00000001	/*%< close read side */
#define ISC_SOCKSHUT_SEND	0x00000002	/*%< close write side */
#define ISC_SOCKSHUT_ALL	0x00000003	/*%< close them all */
/*@}*/

/*@{*/
/*!
 * What I/O events to cancel in isc_socket_cancel() calls.
 */
#define ISC_SOCKCANCEL_RECV	0x00000001	/*%< cancel recv */
#define ISC_SOCKCANCEL_SEND	0x00000002	/*%< cancel send */
#define ISC_SOCKCANCEL_ACCEPT	0x00000004	/*%< cancel accept */
#define ISC_SOCKCANCEL_CONNECT	0x00000008	/*%< cancel connect */
#define ISC_SOCKCANCEL_ALL	0x0000000f	/*%< cancel everything */
/*@}*/

/*@{*/
/*!
 * Flags for isc_socket_send() and isc_socket_recv() calls.
 */
#define ISC_SOCKFLAG_IMMEDIATE	0x00000001	/*%< send event only if needed */
#define ISC_SOCKFLAG_NORETRY	0x00000002	/*%< drop failed UDP sends */
/*@}*/

/***
 *** Socket and Socket Manager Functions
 ***
 *** Note: all Ensures conditions apply only if the result is success for
 *** those functions which return an isc_result.
 ***/

isc_result_t
isc_socket_create(isc_socketmgr_t *manager,
		  int pf,
		  isc_sockettype_t type,
		  isc_socket_t **socketp);
/*%<
 * Create a new 'type' socket managed by 'manager'.
 *
 * Note:
 *
 *\li	'pf' is the desired protocol family, e.g. PF_INET or PF_INET6.
 *
 * Requires:
 *
 *\li	'manager' is a valid manager
 *
 *\li	'socketp' is a valid pointer, and *socketp == NULL
 *
 * Ensures:
 *
 *	'*socketp' is attached to the newly created socket
 *
 * Returns:
 *
 *\li	#ISC_R_SUCCESS
 *\li	#ISC_R_NOMEMORY
 *\li	#ISC_R_NORESOURCES
 *\li	#ISC_R_UNEXPECTED
 */

void
isc_socket_cancel(isc_socket_t *sock, isc_task_t *task,
		  unsigned int how);
/*%<
 * Cancel pending I/O of the type specified by "how".
 *
 * Note: if "task" is NULL, then the cancel applies to all tasks using the
 * socket.
 *
 * Requires:
 *
 * \li	"socket" is a valid socket
 *
 * \li	"task" is NULL or a valid task
 *
 * "how" is a bitmask describing the type of cancelation to perform.
 * The type ISC_SOCKCANCEL_ALL will cancel all pending I/O on this
 * socket.
 *
 * \li ISC_SOCKCANCEL_RECV:
 *	Cancel pending isc_socket_recv() calls.
 *
 * \li ISC_SOCKCANCEL_SEND:
 *	Cancel pending isc_socket_send() and isc_socket_sendto() calls.
 *
 * \li ISC_SOCKCANCEL_ACCEPT:
 *	Cancel pending isc_socket_accept() calls.
 *
 * \li ISC_SOCKCANCEL_CONNECT:
 *	Cancel pending isc_socket_connect() call.
 */

void
isc_socket_shutdown(isc_socket_t *sock, unsigned int how);
/*%<
 * Shutdown 'socket' according to 'how'.
 *
 * Requires:
 *
 * \li	'socket' is a valid socket.
 *
 * \li	'task' is NULL or is a valid task.
 *
 * \li	If 'how' is 'ISC_SOCKSHUT_RECV' or 'ISC_SOCKSHUT_ALL' then
 *
 *		The read queue must be empty.
 *
 *		No further read requests may be made.
 *
 * \li	If 'how' is 'ISC_SOCKSHUT_SEND' or 'ISC_SOCKSHUT_ALL' then
 *
 *		The write queue must be empty.
 *
 *		No further write requests may be made.
 */

void
isc_socket_attach(isc_socket_t *sock, isc_socket_t **socketp);
/*%<
 * Attach *socketp to socket.
 *
 * Requires:
 *
 * \li	'socket' is a valid socket.
 *
 * \li	'socketp' points to a NULL socket.
 *
 * Ensures:
 *
 * \li	*socketp is attached to socket.
 */

void
isc_socket_detach(isc_socket_t **socketp);
/*%<
 * Detach *socketp from its socket.
 *
 * Requires:
 *
 * \li	'socketp' points to a valid socket.
 *
 * \li	If '*socketp' is the last reference to the socket,
 *	then:
 *
 *		There must be no pending I/O requests.
 *
 * Ensures:
 *
 * \li	*socketp is NULL.
 *
 * \li	If '*socketp' is the last reference to the socket,
 *	then:
 *
 *		The socket will be shutdown (both reading and writing)
 *		for all tasks.
 *
 *		All resources used by the socket have been freed
 */

isc_result_t
isc_socket_bind(isc_socket_t *sock, isc_sockaddr_t *addressp);
/*%<
 * Bind 'socket' to '*addressp'.
 *
 * Requires:
 *
 * \li	'socket' is a valid socket
 *
 * \li	'addressp' points to a valid isc_sockaddr.
 *
 * Returns:
 *
 * \li	ISC_R_SUCCESS
 * \li	ISC_R_NOPERM
 * \li	ISC_R_ADDRNOTAVAIL
 * \li	ISC_R_ADDRINUSE
 * \li	ISC_R_BOUND
 * \li	ISC_R_UNEXPECTED
 */

isc_result_t
isc_socket_filter(isc_socket_t *sock, const char *filter);
/*%<
 * Inform the kernel that it should perform accept filtering.
 * If filter is NULL the current filter will be removed.:w
 */

isc_result_t
isc_socket_listen(isc_socket_t *sock, unsigned int backlog);
/*%<
 * Set listen mode on the socket.  After this call, the only function that
 * can be used (other than attach and detach) is isc_socket_accept().
 *
 * Notes:
 *
 * \li	'backlog' is as in the UNIX system call listen() and may be
 *	ignored by non-UNIX implementations.
 *
 * \li	If 'backlog' is zero, a reasonable system default is used, usually
 *	SOMAXCONN.
 *
 * Requires:
 *
 * \li	'socket' is a valid, bound TCP socket or a valid, bound UNIX socket.
 *
 * Returns:
 *
 * \li	ISC_R_SUCCESS
 * \li	ISC_R_UNEXPECTED
 */

isc_result_t
isc_socket_accept(isc_socket_t *sock,
		  isc_task_t *task, isc_taskaction_t action, const void *arg);
/*%<
 * Queue accept event.  When a new connection is received, the task will
 * get an ISC_SOCKEVENT_NEWCONN event with the sender set to the listen
 * socket.  The new socket structure is sent inside the isc_socket_newconnev_t
 * event type, and is attached to the task 'task'.
 *
 * REQUIRES:
 * \li	'socket' is a valid TCP socket that isc_socket_listen() was called
 *	on.