Import pjproject-2.0.1

1 files changed, 1406 insertions, 0 deletions

diff --git a/pjsip/include/pjsip/sip_transport.h b/pjsip/include/pjsip/sip_transport.h
new file mode 100644
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+++ b/pjsip/include/pjsip/sip_transport.h
@@ -0,0 +1,1406 @@
+/* $Id: sip_transport.h 4173 2012-06-20 10:39:05Z ming $ */
+/* 
+ * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
+ * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+#ifndef __PJSIP_SIP_TRANSPORT_H__
+#define __PJSIP_SIP_TRANSPORT_H__
+
+/**
+ * @file sip_transport.h
+ * @brief SIP Transport
+ */
+
+#include <pjsip/sip_msg.h>
+#include <pjsip/sip_parser.h>
+#include <pjsip/sip_resolve.h>
+#include <pj/sock.h>
+#include <pj/list.h>
+#include <pj/ioqueue.h>
+#include <pj/timer.h>
+
+PJ_BEGIN_DECL
+
+/**
+ * @defgroup PJSIP_TRANSPORT Transport
+ * @ingroup PJSIP_CORE
+ * @brief This is the transport framework.
+ *
+ * The transport framework is fully extensible. Please see
+ * <A HREF="/docs.htm">PJSIP Developer's Guide</A> PDF
+ * document for more information.
+ *
+ * Application MUST register at least one transport to PJSIP before any
+ * messages can be sent or received. Please see @ref PJSIP_TRANSPORT_UDP
+ * on how to create/register UDP transport to the transport framework.
+ *
+ * @{
+ */
+
+/*****************************************************************************
+ *
+ * GENERAL TRANSPORT (NAMES, TYPES, ETC.)
+ *
+ *****************************************************************************/
+
+/*
+ * Forward declaration for transport factory (since it is referenced by
+ * the transport factory itself).
+ */
+typedef struct pjsip_tpfactory pjsip_tpfactory;
+
+
+/**
+ * Flags for SIP transports.
+ */
+enum pjsip_transport_flags_e
+{
+    PJSIP_TRANSPORT_RELIABLE	    = 1,    /**< Transport is reliable.	    */
+    PJSIP_TRANSPORT_SECURE	    = 2,    /**< Transport is secure.	    */
+    PJSIP_TRANSPORT_DATAGRAM	    = 4     /**< Datagram based transport.  
+					         (it's also assumed to be 
+						 connectionless)	    */
+};
+
+/**
+ * Check if transport tp is reliable.
+ */
+#define PJSIP_TRANSPORT_IS_RELIABLE(tp)	    \
+	    ((tp)->flag & PJSIP_TRANSPORT_RELIABLE)
+
+/**
+ * Check if transport tp is secure.
+ */
+#define PJSIP_TRANSPORT_IS_SECURE(tp)	    \
+	    ((tp)->flag & PJSIP_TRANSPORT_SECURE)
+
+/**
+ * Register new transport type to PJSIP. The PJSIP transport framework
+ * contains the info for some standard transports, as declared by
+ * #pjsip_transport_type_e. Application may use non-standard transport
+ * with PJSIP, but before it does so, it must register the information
+ * about the new transport type to PJSIP by calling this function.
+ *
+ * @param tp_flag   The flags describing characteristics of this
+ *		    transport type.
+ * @param tp_name   Transport type name.
+ * @param def_port  Default port to be used for the transport.
+ * @param p_tp_type On successful registration, it will be filled with
+ *		    the registered type. This argument is optional.
+ *
+ * @return	    PJ_SUCCESS if registration is successful, or
+ *		    PJSIP_ETYPEEXISTS if the same transport type has
+ *		    already been registered.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_register_type(unsigned tp_flag,
+						   const char *tp_name,
+						   int def_port,
+						   int *p_tp_type);
+
+
+/**
+ * Get the transport type from the transport name.
+ *
+ * @param name	    Transport name, such as "TCP", or "UDP".
+ *
+ * @return	    The transport type, or PJSIP_TRANSPORT_UNSPECIFIED if 
+ *		    the name is not recognized as the name of supported 
+ *		    transport.
+ */
+PJ_DECL(pjsip_transport_type_e) 
+pjsip_transport_get_type_from_name(const pj_str_t *name);
+
+/**
+ * Get the transport type for the specified flags.
+ *
+ * @param flag	    The transport flag.
+ *
+ * @return	    Transport type.
+ */
+PJ_DECL(pjsip_transport_type_e) 
+pjsip_transport_get_type_from_flag(unsigned flag);
+
+/**
+ * Get the socket address family of a given transport type.
+ *
+ * @param type	    Transport type.
+ *
+ * @return	    Transport type.
+ */
+PJ_DECL(int) pjsip_transport_type_get_af(pjsip_transport_type_e type);
+
+/**
+ * Get transport flag from type.
+ *
+ * @param type	    Transport type.
+ *
+ * @return	    Transport flags.
+ */
+PJ_DECL(unsigned)
+pjsip_transport_get_flag_from_type( pjsip_transport_type_e type );
+
+/**
+ * Get the default SIP port number for the specified type.
+ *
+ * @param type	    Transport type.
+ *
+ * @return	    The port number, which is the default SIP port number for
+ *		    the specified type.
+ */
+PJ_DECL(int) 
+pjsip_transport_get_default_port_for_type(pjsip_transport_type_e type);
+
+/**
+ * Get transport type name.
+ *
+ * @param t	    Transport type.
+ *
+ * @return	    Transport name.
+ */
+PJ_DECL(const char*) pjsip_transport_get_type_name(pjsip_transport_type_e t);
+
+/**
+ * Get longer description for the specified transport type.
+ *
+ * @param t	    Transport type.
+ *
+ * @return	    Transport description.
+ */
+PJ_DECL(const char*) pjsip_transport_get_type_desc(pjsip_transport_type_e t);
+
+
+
+/*****************************************************************************
+ *
+ * TRANSPORT SELECTOR.
+ *
+ *****************************************************************************/
+
+/**
+ * This structure describes the type of data in pjsip_tpselector.
+ */
+typedef enum pjsip_tpselector_type
+{
+    /** Transport is not specified. */
+    PJSIP_TPSELECTOR_NONE,
+
+    /** Use the specific transport to send request. */
+    PJSIP_TPSELECTOR_TRANSPORT,
+
+    /** Use the specific listener to send request. */
+    PJSIP_TPSELECTOR_LISTENER,
+
+} pjsip_tpselector_type;
+
+
+/**
+ * This structure describes the transport/listener preference to be used
+ * when sending outgoing requests.
+ *
+ * Normally transport will be selected automatically according to rules about
+ * sending requests. But some applications (such as proxies or B2BUAs) may 
+ * want to explicitly use specific transport to send requests, for example
+ * when they want to make sure that outgoing request should go from a specific
+ * network interface.
+ *
+ * The pjsip_tpselector structure is used for that purpose, i.e. to allow
+ * application specificly request that a particular transport/listener
+ * should be used to send request. This structure is used when calling
+ * pjsip_tsx_set_transport() and pjsip_dlg_set_transport().
+ */
+typedef struct pjsip_tpselector
+{
+    /** The type of data in the union */
+    pjsip_tpselector_type   type;
+
+    /** Union representing the transport/listener criteria to be used. */
+    union {
+	pjsip_transport	*transport;
+	pjsip_tpfactory	*listener;
+	void		*ptr;
+    } u;
+
+} pjsip_tpselector;
+
+
+/**
+ * Add transport/listener reference in the selector to prevent the specified
+ * transport/listener from being destroyed while application still has
+ * reference to it.
+ *
+ * @param sel	The transport selector.
+ */
+PJ_DECL(void) pjsip_tpselector_add_ref(pjsip_tpselector *sel);
+
+
+/**
+ * Decrement transport/listener reference in the selector.
+ * @param sel	The transport selector
+ */
+PJ_DECL(void) pjsip_tpselector_dec_ref(pjsip_tpselector *sel);
+
+
+/*****************************************************************************
+ *
+ * RECEIVE DATA BUFFER.
+ *
+ *****************************************************************************/
+
+/** 
+ * A customized ioqueue async operation key which is used by transport
+ * to locate rdata when a pending read operation completes.
+ */
+typedef struct pjsip_rx_data_op_key
+{
+    pj_ioqueue_op_key_t		op_key;	/**< ioqueue op_key.		*/
+    pjsip_rx_data	       *rdata;	/**< rdata associated with this */
+} pjsip_rx_data_op_key;
+
+
+/**
+ * Incoming message buffer.
+ * This structure keep all the information regarding the received message. This
+ * buffer lifetime is only very short, normally after the transaction has been
+ * called, this buffer will be deleted/recycled. So care must be taken when
+ * allocating storage from the pool of this buffer.
+ */
+struct pjsip_rx_data
+{
+
+    /**
+     * tp_info is part of rdata that remains static for the duration of the
+     * buffer. It is initialized when the buffer was created by transport.
+     */
+    struct 
+    {
+	/** Memory pool for this buffer. */
+	pj_pool_t		*pool;
+
+	/** The transport object which received this packet. */
+	pjsip_transport		*transport;
+
+	/** Other transport specific data to be attached to this buffer. */
+	void			*tp_data;
+
+	/** Ioqueue key. */
+	pjsip_rx_data_op_key	 op_key;
+
+    } tp_info;
+
+
+    /**
+     * pkt_info is initialized by transport when it receives an incoming
+     * packet.
+     */
+    struct
+    {
+	/** Time when the message was received. */
+	pj_time_val		 timestamp;
+
+	/** Pointer to the original packet. */
+	char			 packet[PJSIP_MAX_PKT_LEN];
+
+	/** Zero termination for the packet. */
+	pj_uint32_t		 zero;
+
+	/** The length of the packet received. */
+	pj_ssize_t		 len;
+
+	/** The source address from which the packet was received. */
+	pj_sockaddr		 src_addr;
+
+	/** The length of the source address. */
+	int			 src_addr_len;
+
+	/** The IP source address string (NULL terminated). */
+	char			 src_name[PJ_INET6_ADDRSTRLEN];
+
+	/** The IP source port number. */
+	int			 src_port;
+
+    } pkt_info;
+
+
+    /**
+     * msg_info is initialized by transport mgr (tpmgr) before this buffer
+     * is passed to endpoint.
+     */
+    struct
+    {
+	/** Start of msg buffer. */
+	char			*msg_buf;
+
+	/** Length fo message. */
+	int			 len;
+
+	/** The parsed message, if any. */
+	pjsip_msg		*msg;
+
+	/** Short description about the message. 
+	 *  Application should use #pjsip_rx_data_get_info() instead.
+	 */
+	char			*info;
+
+	/** The Call-ID header as found in the message. */
+	pjsip_cid_hdr		*cid;
+
+	/** The From header as found in the message. */
+	pjsip_from_hdr		*from;
+
+	/** The To header as found in the message. */
+	pjsip_to_hdr		*to;
+
+	/** The topmost Via header as found in the message. */
+	pjsip_via_hdr		*via;
+
+	/** The CSeq header as found in the message. */
+	pjsip_cseq_hdr		*cseq;
+
+	/** Max forwards header. */
+	pjsip_max_fwd_hdr	*max_fwd;
+
+	/** The first route header. */
+	pjsip_route_hdr		*route;
+
+	/** The first record-route header. */
+	pjsip_rr_hdr		*record_route;
+
+	/** Content-type header. */
+	pjsip_ctype_hdr		*ctype;
+
+	/** Content-length header. */
+	pjsip_clen_hdr		*clen;
+
+	/** "Require" header containing aggregates of all Require
+	 *  headers found in the message, or NULL. 
+	 */
+	pjsip_require_hdr	*require;
+
+	/** "Supported" header containing aggregates of all Supported
+	 *  headers found in the message, or NULL. 
+	 */
+	pjsip_supported_hdr	*supported;
+
+	/** The list of error generated by the parser when parsing 
+	    this message. 
+	 */
+	pjsip_parser_err_report parse_err;
+
+    } msg_info;
+
+
+    /**
+     * endpt_info is initialized by endpoint after this buffer reaches
+     * endpoint.
+     */
+    struct
+    {
+	/** 
+	 * Data attached by modules to this message. 
+	 */
+	void	*mod_data[PJSIP_MAX_MODULE];
+
+    } endpt_info;
+
+};
+
+/**
+ * Get printable information about the message in the rdata.
+ *
+ * @param rdata	    The receive data buffer.
+ *
+ * @return	    Printable information.
+ */
+PJ_DECL(char*) pjsip_rx_data_get_info(pjsip_rx_data *rdata);
+
+
+/*****************************************************************************
+ *
+ * TRANSMIT DATA BUFFER MANIPULATION.
+ *
+ *****************************************************************************/
+
+/** Customized ioqueue async operation key, used by transport to keep
+ *  callback parameters.
+ */
+typedef struct pjsip_tx_data_op_key
+{
+    /** ioqueue pending operation key. */
+    pj_ioqueue_op_key_t	    key;
+
+    /** Transmit data associated with this key. */
+    pjsip_tx_data	   *tdata;
+
+    /** Arbitrary token (attached by transport) */
+    void		   *token;
+
+    /** Callback to be called when pending transmit operation has
+        completed.
+     */
+    void		  (*callback)(pjsip_transport*,void*,pj_ssize_t);
+} pjsip_tx_data_op_key;
+
+
+/**
+ * Data structure for sending outgoing message. Application normally creates
+ * this buffer by calling #pjsip_endpt_create_tdata.
+ *
+ * The lifetime of this buffer is controlled by the reference counter in this
+ * structure, which is manipulated by calling #pjsip_tx_data_add_ref and
+ * #pjsip_tx_data_dec_ref. When the reference counter has reached zero, then
+ * this buffer will be destroyed.
+ *
+ * A transaction object normally will add reference counter to this buffer
+ * when application calls #pjsip_tsx_send_msg, because it needs to keep the
+ * message for retransmission. The transaction will release the reference
+ * counter once its state has reached final state.
+ */
+struct pjsip_tx_data
+{
+    /** This is for transmission queue; it's managed by transports. */
+    PJ_DECL_LIST_MEMBER(struct pjsip_tx_data);
+
+    /** Memory pool for this buffer. */
+    pj_pool_t		*pool;
+
+    /** A name to identify this buffer. */
+    char		 obj_name[PJ_MAX_OBJ_NAME];
+
+    /** Short information describing this buffer and the message in it. 
+     *  Application should use #pjsip_tx_data_get_info() instead of
+     *  directly accessing this member.
+     */
+    char		*info;
+
+    /** For response message, this contains the reference to timestamp when 
+     *  the original request message was received. The value of this field
+     *  is set when application creates response message to a request by
+     *  calling #pjsip_endpt_create_response.
+     */
+    pj_time_val		 rx_timestamp;
+
+    /** The transport manager for this buffer. */
+    pjsip_tpmgr		*mgr;
+
+    /** Ioqueue asynchronous operation key. */
+    pjsip_tx_data_op_key op_key;
+
+    /** Lock object. */
+    pj_lock_t		*lock;
+
+    /** The message in this buffer. */
+    pjsip_msg 		*msg;
+
+    /** Strict route header saved by #pjsip_process_route_set(), to be
+     *  restored by #pjsip_restore_strict_route_set().
+     */
+    pjsip_route_hdr	*saved_strict_route;
+
+    /** Buffer to the printed text representation of the message. When the
+     *  content of this buffer is set, then the transport will send the content
+     *  of this buffer instead of re-printing the message structure. If the
+     *  message structure has changed, then application must invalidate this
+     *  buffer by calling #pjsip_tx_data_invalidate_msg.
+     */
+    pjsip_buffer	 buf;
+
+    /** Reference counter. */
+    pj_atomic_t		*ref_cnt;
+
+    /** Being processed by transport? */
+    int			 is_pending;
+
+    /** Transport manager internal. */
+    void		*token;
+
+    /** Callback to be called when this tx_data has been transmitted.	*/
+    void	       (*cb)(void*, pjsip_tx_data*, pj_ssize_t);
+
+    /** Destination information, to be used to determine the network address
+     *  of the message. For a request, this information is  initialized when
+     *  the request is sent with #pjsip_endpt_send_request_stateless() and
+     *  network address is resolved. For CANCEL request, this information
+     *  will be copied from the original INVITE to make sure that the CANCEL
+     *  request goes to the same physical network address as the INVITE
+     *  request.
+     */
+    struct
+    {
+	/** Server name. 
+	 */
+	pj_str_t		 name;
+
+	/** Server addresses resolved. 
+	 */
+	pjsip_server_addresses   addr;
+
+	/** Current server address being tried. 
+	 */
+	unsigned cur_addr;
+
+    } dest_info;
+
+    /** Transport information, only valid during on_tx_request() and 
+     *  on_tx_response() callback.
+     */
+    struct
+    {
+	pjsip_transport	    *transport;	    /**< Transport being used.	*/
+	pj_sockaddr	     dst_addr;	    /**< Destination address.	*/
+	int		     dst_addr_len;  /**< Length of address.	*/
+	char		     dst_name[PJ_INET6_ADDRSTRLEN]; /**< Destination address.	*/
+	int		     dst_port;	    /**< Destination port.	*/
+    } tp_info;
+
+    /** 
+     * Transport selector, to specify which transport to be used. 
+     * The value here must be set with pjsip_tx_data_set_transport(),
+     * to allow reference counter to be set properly.
+     */
+    pjsip_tpselector	    tp_sel;
+
+    /**
+     * Special flag to indicate that this transmit data is a request that has
+     * been updated with proper authentication response and is ready to be
+     * sent for retry.
+     */
+    pj_bool_t		    auth_retry;
+
+    /**
+     * Arbitrary data attached by PJSIP modules.
+     */
+    void		    *mod_data[PJSIP_MAX_MODULE];
+
+    /**
+     * If via_addr is set, it will be used as the "sent-by" field of the
+     * Via header for outgoing requests as long as the request uses via_tp
+     * transport. Normally application should not use or access these fields.
+     */
+    pjsip_host_port          via_addr;      /**< Via address.	        */
+    const void              *via_tp;        /**< Via transport.	        */
+};
+
+
+/**
+ * Create a new, blank transmit buffer. The reference count is initialized
+ * to zero.
+ *
+ * @param mgr		The transport manager.
+ * @param tdata		Pointer to receive transmit data.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ *
+ * @see pjsip_endpt_create_tdata
+ */
+PJ_DECL(pj_status_t) pjsip_tx_data_create( pjsip_tpmgr *mgr,
+					   pjsip_tx_data **tdata );
+
+/**
+ * Add reference counter to the transmit buffer. The reference counter controls
+ * the life time of the buffer, ie. when the counter reaches zero, then it 
+ * will be destroyed.
+ *
+ * @param tdata	    The transmit buffer.
+ */
+PJ_DECL(void) pjsip_tx_data_add_ref( pjsip_tx_data *tdata );
+
+/**
+ * Decrement reference counter of the transmit buffer.
+ * When the transmit buffer is no longer used, it will be destroyed and
+ * caller is informed with PJSIP_EBUFDESTROYED return status.
+ *
+ * @param tdata	    The transmit buffer data.
+ * @return	    This function will always succeeded eventhough the return
+ *		    status is non-zero. A status PJSIP_EBUFDESTROYED will be
+ *		    returned to inform that buffer is destroyed.
+ */
+PJ_DECL(pj_status_t) pjsip_tx_data_dec_ref( pjsip_tx_data *tdata );
+
+/**
+ * Print the SIP message to transmit data buffer's internal buffer. This
+ * may allocate memory for the buffer, if the buffer has not been allocated
+ * yet, and encode the SIP message to that buffer.
+ *
+ * @param tdata	    The transmit buffer.
+ *
+ * @return	    PJ_SUCCESS on success of the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_tx_data_encode(pjsip_tx_data *tdata);
+
+/**
+ * Check if transmit data buffer contains a valid message.
+ *
+ * @param tdata	    The transmit buffer.
+ * @return	    Non-zero (PJ_TRUE) if buffer contains a valid message.
+ */
+PJ_DECL(pj_bool_t) pjsip_tx_data_is_valid( pjsip_tx_data *tdata );
+
+/**
+ * Invalidate the print buffer to force message to be re-printed. Call
+ * when the message has changed after it has been printed to buffer. The
+ * message is printed to buffer normally by transport when it is about to be 
+ * sent to the wire. Subsequent sending of the message will not cause
+ * the message to be re-printed, unless application invalidates the buffer
+ * by calling this function.
+ *
+ * @param tdata	    The transmit buffer.
+ */
+PJ_DECL(void) pjsip_tx_data_invalidate_msg( pjsip_tx_data *tdata );
+
+/**
+ * Get short printable info about the transmit data. This will normally return
+ * short information about the message.
+ *
+ * @param tdata	    The transmit buffer.
+ *
+ * @return	    Null terminated info string.
+ */
+PJ_DECL(char*) pjsip_tx_data_get_info( pjsip_tx_data *tdata );
+
+/**
+ * Set the explicit transport to be used when sending this transmit data.
+ * Application should not need to call this function, but rather use
+ * pjsip_tsx_set_transport() and pjsip_dlg_set_transport() instead (which
+ * will call this function).
+ *
+ * @param tdata	    The transmit buffer.
+ * @param sel	    Transport selector.
+ *
+ * @return	    PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjsip_tx_data_set_transport(pjsip_tx_data *tdata,
+						 const pjsip_tpselector *sel);
+
+
+/*****************************************************************************
+ *
+ * TRANSPORT
+ *
+ *****************************************************************************/
+/**
+ * Type of callback to receive transport operation status.
+ */
+typedef void (*pjsip_transport_callback)(pjsip_transport *tp, void *token,
+                                         pj_ssize_t sent_bytes);
+
+/**
+ * This structure describes transport key to be registered to hash table.
+ */
+typedef struct pjsip_transport_key
+{
+    /**
+     * Transport type.
+     */
+    long		    type;
+
+    /**
+     * Destination address.
+     */
+    pj_sockaddr		    rem_addr;
+
+} pjsip_transport_key;
+
+
+/**
+ * Enumeration of transport direction types.
+ */
+typedef enum pjsip_transport_dir
+{
+    PJSIP_TP_DIR_NONE,		    /**< Direction not set, normally used by
+				         connectionless transports such as 
+					 UDP transport.			    */
+    PJSIP_TP_DIR_OUTGOING,	    /**< Outgoing connection or client mode,
+				         this is only for connection-oriented 
+					 transports.			    */
+    PJSIP_TP_DIR_INCOMING,	    /**< Incoming connection or server mode,
+					 this is only for connection-oriented
+					 transports.			    */
+} pjsip_transport_dir;
+
+
+/**
+ * This structure represent the "public" interface of a SIP transport.
+ * Applications normally extend this structure to include transport
+ * specific members.
+ */
+struct pjsip_transport
+{
+    char		    obj_name[PJ_MAX_OBJ_NAME];	/**< Name. */
+
+    pj_pool_t		   *pool;	    /**< Pool used by transport.    */
+    pj_atomic_t		   *ref_cnt;	    /**< Reference counter.	    */
+    pj_lock_t		   *lock;	    /**< Lock object.		    */
+    pj_bool_t		    tracing;	    /**< Tracing enabled?	    */
+    pj_bool_t		    is_shutdown;    /**< Being shutdown?	    */
+    pj_bool_t		    is_destroying;  /**< Destroy in progress?	    */
+
+    /** Key for indexing this transport in hash table. */
+    pjsip_transport_key	    key;
+
+    char		   *type_name;	    /**< Type name.		    */
+    unsigned		    flag;	    /**< #pjsip_transport_flags_e   */
+    char		   *info;	    /**< Transport info/description.*/
+
+    int			    addr_len;	    /**< Length of addresses.	    */
+    pj_sockaddr		    local_addr;	    /**< Bound address.		    */
+    pjsip_host_port	    local_name;	    /**< Published name (eg. STUN). */
+    pjsip_host_port	    remote_name;    /**< Remote address name.	    */
+    pjsip_transport_dir	    dir;	    /**< Connection direction.	    */
+    
+    pjsip_endpoint	   *endpt;	    /**< Endpoint instance.	    */
+    pjsip_tpmgr		   *tpmgr;	    /**< Transport manager.	    */
+    pj_timer_entry	    idle_timer;	    /**< Timer when ref cnt is zero.*/
+
+    void		   *data;	    /**< Internal transport data.   */
+
+    /**
+     * Function to be called by transport manager to send SIP message.
+     *
+     * @param transport	    The transport to send the message.
+     * @param packet	    The buffer to send.
+     * @param length	    The length of the buffer to send.
+     * @param op_key	    Completion token, which will be supplied to
+     *			    caller when pending send operation completes.
+     * @param rem_addr	    The remote destination address.
+     * @param addr_len	    Size of remote address.
+     * @param callback	    If supplied, the callback will be called
+     *			    once a pending transmission has completed. If
+     *			    the function completes immediately (i.e. return
+     *			    code is not PJ_EPENDING), the callback will not
+     *			    be called.
+     *
+     * @return		    Should return PJ_SUCCESS only if data has been
+     *			    succesfully queued to operating system for 
+     *			    transmission. Otherwise it may return PJ_EPENDING
+     *			    if the underlying transport can not send the
+     *			    data immediately and will send it later, which in
+     *			    this case caller doesn't have to do anything 
+     *			    except wait the calback to be called, if it 
+     *			    supplies one.
+     *			    Other return values indicate the error code.
+     */
+    pj_status_t (*send_msg)(pjsip_transport *transport, 
+			    pjsip_tx_data *tdata,
+			    const pj_sockaddr_t *rem_addr,
+			    int addr_len,
+			    void *token,
+			    pjsip_transport_callback callback);
+
+    /**
+     * Instruct the transport to initiate graceful shutdown procedure.
+     * After all objects release their reference to this transport,
+     * the transport will be deleted.
+     *
+     * Note that application MUST use #pjsip_transport_shutdown() instead.
+     *
+     * @param transport	    The transport.
+     *
+     * @return		    PJ_SUCCESS on success.
+     */
+    pj_status_t (*do_shutdown)(pjsip_transport *transport);
+
+    /**
+     * Forcefully destroy this transport regardless whether there are
+     * objects that currently use this transport. This function should only
+     * be called by transport manager or other internal objects (such as the
+     * transport itself) who know what they're doing. Application should use
+     * #pjsip_transport_shutdown() instead.
+     *
+     * @param transport	    The transport.
+     *
+     * @return		    PJ_SUCCESS on success.
+     */
+    pj_status_t (*destroy)(pjsip_transport *transport);
+
+    /*
+     * Application may extend this structure..
+     */
+};
+
+
+/**
+ * Register a transport instance to the transport manager. This function
+ * is normally called by the transport instance when it is created
+ * by application.
+ *
+ * @param mgr		The transport manager.
+ * @param tp		The new transport to be registered.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_register( pjsip_tpmgr *mgr,
+					       pjsip_transport *tp );
+
+
+/**
+ * Start graceful shutdown procedure for this transport. After graceful
+ * shutdown has been initiated, no new reference can be obtained for
+ * the transport. However, existing objects that currently uses the
+ * transport may still use this transport to send and receive packets.
+ *
+ * After all objects release their reference to this transport,
+ * the transport will be destroyed immediately.
+ *
+ * @param tp		    The transport.
+ *
+ * @return		    PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_shutdown(pjsip_transport *tp);
+
+/**
+ * Destroy a transport when there is no object currently uses the transport.
+ * This function is normally called internally by transport manager or the
+ * transport itself. Application should use #pjsip_transport_shutdown()
+ * instead.
+ *
+ * @param tp		The transport instance.
+ *
+ * @return		PJ_SUCCESS on success or the appropriate error code.
+ *			Some of possible errors are PJSIP_EBUSY if the 
+ *			transport's reference counter is not zero.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_destroy( pjsip_transport *tp);
+
+/**
+ * Add reference counter to the specified transport. Any objects that wishes
+ * to keep the reference of the transport MUST increment the transport's
+ * reference counter to prevent it from being destroyed.
+ *
+ * @param tp		The transport instance.
+ *
+ * @return		PJ_SUCCESS on success or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_add_ref( pjsip_transport *tp );
+
+/**
+ * Decrement reference counter of the specified transport. When an object no
+ * longer want to keep the reference to the transport, it must decrement the
+ * reference counter. When the reference counter of the transport reaches 
+ * zero, the transport manager will start the idle timer to destroy the
+ * transport if no objects acquire the reference counter during the idle
+ * interval.
+ *
+ * @param tp		The transport instance.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_dec_ref( pjsip_transport *tp );
+
+
+/**
+ * This function is called by transport instances to report an incoming 
+ * packet to the transport manager. The transport manager then would try to
+ * parse all SIP messages in the packet, and for each parsed SIP message, it
+ * would report the message to the SIP endpoint (#pjsip_endpoint).
+ *
+ * @param mgr		The transport manager instance.
+ * @param rdata		The receive data buffer containing the packet. The
+ *			transport MUST fully initialize tp_info and pkt_info
+ *			member of the rdata.
+ *
+ * @return		The number of bytes successfully processed from the
+ *			packet. If the transport is datagram oriented, the
+ *			value will be equal to the size of the packet. For
+ *			stream oriented transport (e.g. TCP, TLS), the value
+ *			returned may be less than the packet size, if 
+ *			partial message is received. The transport then MUST
+ *			keep the remainder part and report it again to
+ *			this function once more data/packet is received.
+ */
+PJ_DECL(pj_ssize_t) pjsip_tpmgr_receive_packet(pjsip_tpmgr *mgr,
+					       pjsip_rx_data *rdata);
+
+
+/*****************************************************************************
+ *
+ * TRANSPORT FACTORY
+ *
+ *****************************************************************************/
+
+
+/**
+ * A transport factory is normally used for connection oriented transports
+ * (such as TCP or TLS) to create instances of transports. It registers
+ * a new transport type to the transport manager, and the transport manager
+ * would ask the factory to create a transport instance when it received
+ * command from application to send a SIP message using the specified
+ * transport type.
+ */
+struct pjsip_tpfactory
+{
+    /** This list is managed by transport manager. */
+    PJ_DECL_LIST_MEMBER(struct pjsip_tpfactory);
+
+    char		    obj_name[PJ_MAX_OBJ_NAME];	/**< Name.	*/
+
+    pj_pool_t		   *pool;	    /**< Owned memory pool.	*/
+    pj_lock_t		   *lock;	    /**< Lock object.		*/
+
+    pjsip_transport_type_e  type;	    /**< Transport type.	*/
+    char		   *type_name;      /**< Type string name.	*/
+    unsigned		    flag;	    /**< Transport flag.	*/
+
+    pj_sockaddr		    local_addr;	    /**< Bound address.		*/
+    pjsip_host_port	    addr_name;	    /**< Published name.	*/
+
+    /**
+     * Create new outbound connection suitable for sending SIP message
+     * to specified remote address.
+     * Note that the factory is responsible for both creating the
+     * transport and registering it to the transport manager.
+     */
+    pj_status_t (*create_transport)(pjsip_tpfactory *factory,
+				    pjsip_tpmgr *mgr,
+				    pjsip_endpoint *endpt,
+				    const pj_sockaddr *rem_addr,
+				    int addr_len,
+				    pjsip_transport **transport);
+
+    /**
+     * Create new outbound connection suitable for sending SIP message
+     * to specified remote address by also considering outgoing SIP 
+     * message data.
+     * Note that the factory is responsible for both creating the
+     * transport and registering it to the transport manager.
+     */
+    pj_status_t (*create_transport2)(pjsip_tpfactory *factory,
+				     pjsip_tpmgr *mgr,
+				     pjsip_endpoint *endpt,
+				     const pj_sockaddr *rem_addr,
+				     int addr_len,
+				     pjsip_tx_data *tdata,
+				     pjsip_transport **transport);
+
+    /**
+     * Destroy the listener.
+     */
+    pj_status_t (*destroy)(pjsip_tpfactory *factory);
+
+    /*
+     * Application may extend this structure..
+     */
+};
+
+
+
+/**
+ * Register a transport factory.
+ *
+ * @param mgr		The transport manager.
+ * @param tpf		Transport factory.
+ *
+ * @return		PJ_SUCCESS if listener was successfully created.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_register_tpfactory(pjsip_tpmgr *mgr,
+						    pjsip_tpfactory *tpf);
+
+/**
+ * Unregister factory.
+ *
+ * @param mgr		The transport manager.
+ * @param tpf		Transport factory.
+ *
+ * @return		PJ_SUCCESS is sucessfully unregistered.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_unregister_tpfactory(pjsip_tpmgr *mgr,
+						      pjsip_tpfactory *tpf);
+
+
+/*****************************************************************************
+ *
+ * TRANSPORT MANAGER
+ *
+ *****************************************************************************/
+
+/**
+ * Type of callback to be called when transport manager receives incoming
+ * SIP message.
+ *
+ * @param ep	    Endpoint.
+ * @param status    Receiption status.
+ * @param rd	    Received packet.
+ */
+typedef void (*pjsip_rx_callback)(pjsip_endpoint *ep, pj_status_t status, 
+				  pjsip_rx_data *rd);
+
+/**
+ * Type of callback to be called before transport manager is about
+ * to transmit SIP message.
+ *
+ * @param ep	    Endpoint.
+ * @param td	    Transmit data.
+ */
+typedef pj_status_t (*pjsip_tx_callback)(pjsip_endpoint *ep, pjsip_tx_data*td);
+
+/**
+ * Create a transport manager. Normally application doesn't need to call
+ * this function directly, since a transport manager will be created and
+ * destroyed automatically by the SIP endpoint.
+ *
+ * @param pool	    Pool.
+ * @param endpt	    Endpoint instance.
+ * @param rx_cb	    Callback to receive incoming message.
+ * @param tx_cb	    Callback to be called before transport manager is sending
+ *		    outgoing message.
+ * @param p_mgr	    Pointer to receive the new transport manager.
+ *
+ * @return	    PJ_SUCCESS or the appropriate error code on error.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_create( pj_pool_t *pool,
+					 pjsip_endpoint * endpt,
+					 pjsip_rx_callback rx_cb,
+					 pjsip_tx_callback tx_cb,
+					 pjsip_tpmgr **p_mgr);
+
+
+/**
+ * Find out the appropriate local address info (IP address and port) to
+ * advertise in Contact header based on the remote address to be 
+ * contacted. The local address info would be the address name of the
+ * transport or listener which will be used to send the request.
+ *
+ * In this implementation, it will only select the transport based on
+ * the transport type in the request.
+ *
+ * @param tpmgr	    The transport manager.
+ * @param pool	    Pool to allocate memory for the IP address.
+ * @param type	    Destination address to contact.
+ * @param sel	    Optional pointer to prefered transport, if any.
+ * @param ip_addr   Pointer to receive the IP address.
+ * @param port	    Pointer to receive the port number.
+ *
+ * @return	    PJ_SUCCESS, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_find_local_addr( pjsip_tpmgr *tpmgr,
+						  pj_pool_t *pool,
+						  pjsip_transport_type_e type,
+						  const pjsip_tpselector *sel,
+						  pj_str_t *ip_addr,
+						  int *port);
+
+/**
+ * Return number of transports currently registered to the transport
+ * manager.
+ *
+ * @param mgr	    The transport manager.
+ *
+ * @return	    Number of transports.
+ */
+PJ_DECL(unsigned) pjsip_tpmgr_get_transport_count(pjsip_tpmgr *mgr);
+
+
+/**
+ * Destroy a transport manager. Normally application doesn't need to call
+ * this function directly, since a transport manager will be created and
+ * destroyed automatically by the SIP endpoint.
+ *
+ * @param mgr	    The transport manager.
+ *
+ * @return	    PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_destroy(pjsip_tpmgr *mgr);
+
+
+/**
+ * Dump transport info and status to log.
+ *
+ * @param mgr	    The transport manager.
+ */
+PJ_DECL(void) pjsip_tpmgr_dump_transports(pjsip_tpmgr *mgr);
+
+
+/*****************************************************************************
+ *
+ * PUBLIC API
+ *
+ *****************************************************************************/
+
+
+/**
+ * Find transport to be used to send message to remote destination. If no
+ * suitable transport is found, a new one will be created.
+ *
+ * This is an internal function since normally application doesn't have access
+ * to transport manager. Application should use pjsip_endpt_acquire_transport()
+ * instead.
+ *
+ * @param mgr	    The transport manager instance.
+ * @param type	    The type of transport to be acquired.
+ * @param remote    The remote address to send message to.
+ * @param addr_len  Length of the remote address.
+ * @param sel	    Optional pointer to transport selector instance which is
+ *		    used to find explicit transport, if required.
+ * @param tp	    Pointer to receive the transport instance, if one is found.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_acquire_transport(pjsip_tpmgr *mgr,
+						   pjsip_transport_type_e type,
+						   const pj_sockaddr_t *remote,
+						   int addr_len,
+						   const pjsip_tpselector *sel,
+						   pjsip_transport **tp);
+
+/**
+ * Find suitable transport for sending SIP message to specified remote 
+ * destination by also considering the outgoing SIP message. If no suitable 
+ * transport is found, a new one will be created.
+ *
+ * This is an internal function since normally application doesn't have access
+ * to transport manager. Application should use pjsip_endpt_acquire_transport2()
+ * instead.
+ *
+ * @param mgr	    The transport manager instance.
+ * @param type	    The type of transport to be acquired.
+ * @param remote    The remote address to send message to.
+ * @param addr_len  Length of the remote address.
+ * @param sel	    Optional pointer to transport selector instance which is
+ *		    used to find explicit transport, if required.
+ * @param tdata	    Optional pointer to data to be sent.
+ * @param tp	    Pointer to receive the transport instance, if one is found.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_acquire_transport2(pjsip_tpmgr *mgr,
+						    pjsip_transport_type_e type,
+						    const pj_sockaddr_t *remote,
+						    int addr_len,
+						    const pjsip_tpselector *sel,
+						    pjsip_tx_data *tdata,
+						    pjsip_transport **tp);
+
+/**
+ * Type of callback to receive notification when message or raw data
+ * has been sent.
+ *
+ * @param token		The token that was given when calling the function
+ *			to send message or raw data.
+ * @param tdata		The transmit buffer used to send the message.
+ * @param bytes_sent	Number of bytes sent. On success, the value will be
+ *			positive number indicating the number of bytes sent.
+ *			On failure, the value will be a negative number of
+ *			the error code (i.e. bytes_sent = -status).
+ */
+typedef void (*pjsip_tp_send_callback)(void *token, pjsip_tx_data *tdata,
+				       pj_ssize_t bytes_sent);
+
+
+/**
+ * This is a low-level function to send a SIP message using the specified
+ * transport to the specified destination.
+ * 
+ * @param tr	    The SIP transport to be used.
+ * @param tdata	    Transmit data buffer containing SIP message.
+ * @param addr	    Destination address.
+ * @param addr_len  Length of destination address.
+ * @param token	    Arbitrary token to be returned back to callback.
+ * @param cb	    Optional callback to be called to notify caller about
+ *		    the completion status of the pending send operation.
+ *
+ * @return	    If the message has been sent successfully, this function
+ *		    will return PJ_SUCCESS and the callback will not be 
+ *		    called. If message cannot be sent immediately, this
+ *		    function will return PJ_EPENDING, and application will
+ *		    be notified later about the completion via the callback.
+ *		    Any statuses other than PJ_SUCCESS or PJ_EPENDING
+ *		    indicates immediate failure, and in this case the 
+ *		    callback will not be called.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_send( pjsip_transport *tr, 
+					   pjsip_tx_data *tdata,
+					   const pj_sockaddr_t *addr,
+					   int addr_len,
+					   void *token,
+					   pjsip_tp_send_callback cb);
+
+
+/**
+ * This is a low-level function to send raw data to a destination.
+ *
+ * See also #pjsip_endpt_send_raw() and #pjsip_endpt_send_raw_to_uri().
+ *
+ * @param mgr	    Transport manager.
+ * @param tp_type   Transport type.
+ * @param sel	    Optional pointer to transport selector instance if
+ *		    application wants to use a specific transport instance
+ *		    rather then letting transport manager finds the suitable
+ *		    transport.
+ * @param tdata	    Optional transmit data buffer to be used. If this value
+ *		    is NULL, this function will create one internally. If
+ *		    tdata is specified, this function will decrement the
+ *		    reference counter upon completion.
+ * @param raw_data  The data to be sent.
+ * @param data_len  The length of the data.
+ * @param addr	    Destination address.
+ * @param addr_len  Length of destination address.
+ * @param token	    Arbitrary token to be returned back to callback.
+ * @param cb	    Optional callback to be called to notify caller about
+ *		    the completion status of the pending send operation.
+ *
+ * @return	    If the message has been sent successfully, this function
+ *		    will return PJ_SUCCESS and the callback will not be 
+ *		    called. If message cannot be sent immediately, this
+ *		    function will return PJ_EPENDING, and application will
+ *		    be notified later about the completion via the callback.
+ *		    Any statuses other than PJ_SUCCESS or PJ_EPENDING
+ *		    indicates immediate failure, and in this case the 
+ *		    callback will not be called.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_send_raw(pjsip_tpmgr *mgr,
+					  pjsip_transport_type_e tp_type,
+					  const pjsip_tpselector *sel,
+					  pjsip_tx_data *tdata,
+					  const void *raw_data,
+					  pj_size_t data_len,
+					  const pj_sockaddr_t *addr,
+					  int addr_len,
+					  void *token,
+					  pjsip_tp_send_callback cb);
+
+
+/**
+ * Enumeration of transport state types.
+ */
+typedef enum pjsip_transport_state
+{
+    PJSIP_TP_STATE_CONNECTED,	    /**< Transport connected, applicable only
+					 to connection-oriented transports
+					 such as TCP and TLS.		    */
+    PJSIP_TP_STATE_DISCONNECTED	    /**< Transport disconnected, applicable
+					 only to connection-oriented 
+					 transports such as TCP and TLS.    */
+} pjsip_transport_state;
+
+
+/**
+ * Definition of transport state listener key.
+ */
+typedef void pjsip_tp_state_listener_key;
+
+/**
+ * Structure of transport state info passed by #pjsip_tp_state_callback.
+ */
+typedef struct pjsip_transport_state_info {
+    /**
+     * The last error code related to the transport state.
+     */
+    pj_status_t		 status;
+
+    /**
+     * Optional extended info, the content is specific for each transport type.
+     */
+    void		*ext_info;
+
+    /**
+     * Optional user data. In global transport state notification, this will
+     * always be NULL.
+     */
+    void		*user_data;
+
+} pjsip_transport_state_info;
+
+
+/**
+ * Type of callback to receive transport state notifications, such as
+ * transport connected/disconnected. Application may shutdown the transport
+ * in this callback.
+ *
+ * @param tp		The transport instance.
+ * @param state		The transport state.
+ * @param info		The transport state info.
+ */
+typedef void (*pjsip_tp_state_callback)(
+				    pjsip_transport *tp,
+				    pjsip_transport_state state,
+				    const pjsip_transport_state_info *info);
+
+
+/**
+ * Set callback of global transport state notification. The caller will be
+ * notified whenever the state of any transport is changed. The type of events
+ * are defined in #pjsip_transport_state.
+ *
+ * Note that this function will override the existing callback, if any, so
+ * application is recommended to keep the old callback and manually forward
+ * the notification to the old callback, otherwise other component that 
+ * concerns about the transport state will no longer receive transport state 
+ * events.
+ * 
+ * @param mgr	    Transport manager.
+ * @param cb	    Callback to be called to notify caller about transport 
+ *		    state changing.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_tpmgr_set_state_cb(pjsip_tpmgr *mgr,
+					      pjsip_tp_state_callback cb);
+
+
+/**
+ * Get the callback of global transport state notification.
+ * 
+ * @param mgr	    Transport manager.
+ *
+ * @return	    The transport state callback or NULL if it is not set.
+ */
+PJ_DECL(pjsip_tp_state_callback) pjsip_tpmgr_get_state_cb(
+					      const pjsip_tpmgr *mgr);
+
+
+/**
+ * Add a listener to the specified transport for transport state notification.
+ * 
+ * @param tp	    The transport.
+ * @param cb	    Callback to be called to notify listener about transport 
+ *		    state changing.
+ * @param user_data The user data.
+ * @param key	    Output key, used to remove this listener.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_add_state_listener (
+					    pjsip_transport *tp,
+					    pjsip_tp_state_callback cb,
+					    void *user_data,
+					    pjsip_tp_state_listener_key **key);
+
+
+/**
+ * Remove a listener from the specified transport for transport state 
+ * notification.
+ * 
+ * @param tp	    The transport.
+ * @param key	    The listener key.
+ * @param user_data The user data, for validation purpose.
+ *
+ * @return	    PJ_SUCCESS on success, or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pjsip_transport_remove_state_listener (
+				    pjsip_transport *tp,
+				    pjsip_tp_state_listener_key *key,
+				    const void *user_data);
+
+
+/**
+ * @}
+ */
+
+
+PJ_END_DECL
+
+#endif	/* __PJSIP_SIP_TRANSPORT_H__ */
+