res_pjsip.h

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Mark Michelson <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

#ifndef _RES_PJSIP_H
#define _RES_PJSIP_H

#include <pjsip.h>
/* Needed for SUBSCRIBE, NOTIFY, and PUBLISH method definitions */
#include <pjsip_simple.h>
#include <pjsip/sip_transaction.h>
#include <pj/timer.h>
/* Needed for pj_sockaddr */
#include <pjlib.h>

#include "asterisk/stringfields.h"
/* Needed for struct ast_sockaddr */
#include "asterisk/netsock2.h"
/* Needed for linked list macros */
#include "asterisk/linkedlists.h"
/* Needed for ast_party_id */
#include "asterisk/channel.h"
/* Needed for ast_sorcery */
#include "asterisk/sorcery.h"
/* Needed for ast_dnsmgr */
#include "asterisk/dnsmgr.h"
/* Needed for ast_endpoint */
#include "asterisk/endpoints.h"
/* Needed for ast_t38_ec_modes */
#include "asterisk/udptl.h"
/* Needed for ast_rtp_dtls_cfg struct */
#include "asterisk/rtp_engine.h"
/* Needed for AST_VECTOR macro */
#include "asterisk/vector.h"
/* Needed for ast_sip_for_each_channel_snapshot struct */
#include "asterisk/stasis_channels.h"
#include "asterisk/stasis_endpoints.h"
#include "asterisk/stream.h"

#define PJSIP_MINVERSION(m,n,p) (((m << 24) | (n << 16) | (p << 8)) >= PJ_VERSION_NUM)

#ifndef PJSIP_EXPIRES_NOT_SPECIFIED
/*
 * Added in pjproject 2.10.0. However define here if someone compiles against a
 * version of pjproject < 2.10.0.
 *
 * Usually defined in pjsip/include/pjsip/sip_msg.h (included as part of <pjsip.h>)
 */
#define PJSIP_EXPIRES_NOT_SPECIFIED ((pj_uint32_t)-1)
#endif

/* Forward declarations of PJSIP stuff */
struct pjsip_rx_data;
struct pjsip_module;
struct pjsip_tx_data;
struct pjsip_dialog;
struct pjsip_transport;
struct pjsip_tpfactory;
struct pjsip_tls_setting;
struct pjsip_tpselector;

/*! \brief Maximum number of ciphers supported for a TLS transport */
#define SIP_TLS_MAX_CIPHERS 64

/*! Maximum number of challenges before assuming that we are in a loop */
#define MAX_RX_CHALLENGES  10

AST_VECTOR(ast_sip_service_route_vector, char *);

/*!
 * \brief Structure for SIP transport information
 */
struct ast_sip_transport_state {
   /*! \brief Transport itself */
   struct pjsip_transport *transport;
   /*! \brief Transport factory */
   struct pjsip_tpfactory *factory;
   /*!
    * Transport id
    * \since 13.8.0
    */
   char *id;
   /*!
    * Transport type
    * \since 13.8.0
    */
   enum ast_transport type;
   /*!
    * Address and port to bind to
    * \since 13.8.0
    */
   pj_sockaddr host;
   /*!
    * TLS settings
    * \since 13.8.0
    */
   pjsip_tls_setting tls;
   /*!
    * Configured TLS ciphers
    * \since 13.8.0
    */
   pj_ssl_cipher ciphers[SIP_TLS_MAX_CIPHERS];
   /*!
    * Optional local network information, used for NAT purposes.
    * "deny" (set) means that it's in the local network. Use the
    * ast_sip_transport_is_nonlocal and ast_sip_transport_is_local
    * macro's.
    * \since 13.8.0
    */
   struct ast_ha *localnet;
   /*!
    * DNS manager for refreshing the external signaling address
    * \since 13.8.0
    */
   struct ast_dnsmgr_entry *external_signaling_address_refresher;
   /*!
    * Optional external signaling address information
    * \since 13.8.0
    */
   struct ast_sockaddr external_signaling_address;
   /*!
    * DNS manager for refreshing the external media address
    * \since 13.18.0
    */
   struct ast_dnsmgr_entry *external_media_address_refresher;
   /*!
    * Optional external signaling address information
    * \since 13.18.0
    */
   struct ast_sockaddr external_media_address;
   /*!
    * Set when this transport is a flow of signaling to a target
    * \since 17.0.0
    */
   int flow;
   /*!
    * The P-Preferred-Identity to use on traffic using this transport
    * \since 17.0.0
    */
   char *preferred_identity;
   /*!
    * The Service Routes to use on traffic using this transport
    * \since 17.0.0
    */
   struct ast_sip_service_route_vector *service_routes;
};

#define ast_sip_transport_is_nonlocal(transport_state, addr) \
   (!transport_state->localnet || ast_apply_ha(transport_state->localnet, addr) == AST_SENSE_ALLOW)

#define ast_sip_transport_is_local(transport_state, addr) \
   (transport_state->localnet && ast_apply_ha(transport_state->localnet, addr) != AST_SENSE_ALLOW)

/*!
 * \brief Transport to bind to
 */
struct ast_sip_transport {
   /*! Sorcery object details */
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Certificate of authority list file */
      AST_STRING_FIELD(ca_list_file);
      /*! Certificate of authority list path */
      AST_STRING_FIELD(ca_list_path);
      /*! Public certificate file */
      AST_STRING_FIELD(cert_file);
      /*! Optional private key of the certificate file */
      AST_STRING_FIELD(privkey_file);
      /*! Password to open the private key */
      AST_STRING_FIELD(password);
      /*! External signaling address */
      AST_STRING_FIELD(external_signaling_address);
      /*! External media address */
      AST_STRING_FIELD(external_media_address);
      /*! Optional domain to use for messages if provided could not be found */
      AST_STRING_FIELD(domain);
      );
   /*! Type of transport */
   enum ast_transport type;
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.8.0 deprecated
    * Address and port to bind to
    */
   pj_sockaddr host;
   /*! Number of simultaneous asynchronous operations */
   unsigned int async_operations;
   /*! Optional external port for signaling */
   unsigned int external_signaling_port;
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.7.1 deprecated
    * TLS settings
    */
   pjsip_tls_setting tls;
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.7.1 deprecated
    * Configured TLS ciphers
    */
   pj_ssl_cipher ciphers[SIP_TLS_MAX_CIPHERS];
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.7.1 deprecated
    * Optional local network information, used for NAT purposes
    */
   struct ast_ha *localnet;
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.7.1 deprecated
    * DNS manager for refreshing the external address
    */
   struct ast_dnsmgr_entry *external_address_refresher;
   /*!
    * \deprecated Moved to ast_sip_transport_state
    * \version 13.7.1 deprecated
    * Optional external address information
    */
   struct ast_sockaddr external_address;
   /*!
    * \deprecated
    * \version 13.7.1 deprecated
    * Transport state information
    */
   struct ast_sip_transport_state *state;
   /*! QOS DSCP TOS bits */
   unsigned int tos;
   /*! QOS COS value */
   unsigned int cos;
   /*! Write timeout */
   int write_timeout;
   /*! Allow reload */
   int allow_reload;
   /*! Automatically send requests out the same transport requests have come in on */
   int symmetric_transport;
   /*! This is a flow to another target */
   int flow;
};

#define SIP_SORCERY_DOMAIN_ALIAS_TYPE "domain_alias"

/*!
 * Details about a SIP domain alias
 */
struct ast_sip_domain_alias {
   /*! Sorcery object details */
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Domain to be aliased to */
      AST_STRING_FIELD(domain);
   );
};

/*!
 * \brief Structure for SIP nat hook information
 */
struct ast_sip_nat_hook {
   /*! Sorcery object details */
   SORCERY_OBJECT(details);
   /*! Callback for when a message is going outside of our local network */
   void (*outgoing_external_message)(struct pjsip_tx_data *tdata, struct ast_sip_transport *transport);
};

/*!
 * \brief Contact associated with an address of record
 */
struct ast_sip_contact {
   /*! Sorcery object details, the id is the aor name plus a random string */
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Full URI of the contact */
      AST_STRING_FIELD(uri);
      /*! Outbound proxy to use for qualify */
      AST_STRING_FIELD(outbound_proxy);
      /*! Path information to place in Route headers */
      AST_STRING_FIELD(path);
      /*! Content of the User-Agent header in REGISTER request */
      AST_STRING_FIELD(user_agent);
      /*! The name of the aor this contact belongs to */
      AST_STRING_FIELD(aor);
      /*! Asterisk Server name */
      AST_STRING_FIELD(reg_server);
      /*! IP-address of the Via header in REGISTER request */
      AST_STRING_FIELD(via_addr);
      /*! Content of the Call-ID header in REGISTER request */
      AST_STRING_FIELD(call_id);
      /*! The name of the endpoint that added the contact */
      AST_STRING_FIELD(endpoint_name);
   );
   /*! Absolute time that this contact is no longer valid after */
   struct timeval expiration_time;
   /*! Frequency to send OPTIONS requests to contact. 0 is disabled. */
   unsigned int qualify_frequency;
   /*! If true authenticate the qualify challenge response if needed */
   int authenticate_qualify;
   /*! Qualify timeout. 0 is diabled. */
   double qualify_timeout;
   /*! Endpoint that added the contact, only available in observers */
   struct ast_sip_endpoint *endpoint;
   /*! Port of the Via header in REGISTER request */
   int via_port;
   /*! If true delete the contact on Asterisk restart/boot */
   int prune_on_boot;
};

/*!
 * \brief Status type for a contact.
 */
enum ast_sip_contact_status_type {
   /*! Frequency > 0, but no response from remote uri */
   UNAVAILABLE,
   /*! Frequency > 0, and got response from remote uri */
   AVAILABLE,
   /*! Default last status, and when a contact status object is not found */
   UNKNOWN,
   /*! Frequency == 0, has a contact, but don't know status (non-qualified) */
   CREATED,
   REMOVED,
};

/*!
 * \brief A contact's status.
 *
 * \detail Maintains a contact's current status and round trip time
 *         if available.
 */
struct ast_sip_contact_status {
   AST_DECLARE_STRING_FIELDS(
      /*! The original contact's URI */
      AST_STRING_FIELD(uri);
      /*! The name of the aor this contact_status belongs to */
      AST_STRING_FIELD(aor);
   );
   /*! The round trip time in microseconds */
   int64_t rtt;
   /*! Current status for a contact (default - unavailable) */
   enum ast_sip_contact_status_type status;
   /*! Last status for a contact (default - unavailable) */
   enum ast_sip_contact_status_type last_status;
   /*! Name of the contact */
   char name[0];
};

/*!
 * \brief A SIP address of record
 */
struct ast_sip_aor {
   /*! Sorcery object details, the id is the AOR name */
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Voicemail boxes for this AOR */
      AST_STRING_FIELD(mailboxes);
      /*! Outbound proxy for OPTIONS requests */
      AST_STRING_FIELD(outbound_proxy);
   );
   /*! Minimum expiration time */
   unsigned int minimum_expiration;
   /*! Maximum expiration time */
   unsigned int maximum_expiration;
   /*! Default contact expiration if one is not provided in the contact */
   unsigned int default_expiration;
   /*! Frequency to send OPTIONS requests to AOR contacts. 0 is disabled. */
   unsigned int qualify_frequency;
   /*! If true authenticate the qualify challenge response if needed */
   int authenticate_qualify;
   /*! Maximum number of external contacts, 0 to disable */
   unsigned int max_contacts;
   /*! Whether to remove any existing contacts not related to an incoming REGISTER when it comes in */
   unsigned int remove_existing;
   /*! Any permanent configured contacts */
   struct ao2_container *permanent_contacts;
   /*! Determines whether SIP Path headers are supported */
   unsigned int support_path;
   /*! Qualify timeout. 0 is diabled. */
   double qualify_timeout;
   /*! Voicemail extension to set in Message-Account */
   char *voicemail_extension;
};

/*!
 * \brief A wrapper for contact that adds the aor_id and
 * a consistent contact id.  Used by ast_sip_for_each_contact.
 */
struct ast_sip_contact_wrapper {
   /*! The id of the parent aor. */
   char *aor_id;
   /*! The id of contact in form of aor_id/contact_uri. */
   char *contact_id;
   /*! Pointer to the actual contact. */
   struct ast_sip_contact *contact;
};

/*!
 * \brief DTMF modes for SIP endpoints
 */
enum ast_sip_dtmf_mode {
   /*! No DTMF to be used */
   AST_SIP_DTMF_NONE,
   /* XXX Should this be 2833 instead? */
   /*! Use RFC 4733 events for DTMF */
   AST_SIP_DTMF_RFC_4733,
   /*! Use DTMF in the audio stream */
   AST_SIP_DTMF_INBAND,
   /*! Use SIP INFO DTMF (blech) */
   AST_SIP_DTMF_INFO,
   /*! Use SIP 4733 if supported by the other side or INBAND if not */
   AST_SIP_DTMF_AUTO,
   /*! Use SIP 4733 if supported by the other side or INFO DTMF (blech) if not */
   AST_SIP_DTMF_AUTO_INFO,
};

/*!
 * \brief Methods of storing SIP digest authentication credentials.
 *
 * Note that both methods result in MD5 digest authentication being
 * used. The two methods simply alter how Asterisk determines the
 * credentials for a SIP authentication
 */
enum ast_sip_auth_type {
   /*! Credentials stored as a username and password combination */
   AST_SIP_AUTH_TYPE_USER_PASS,
   /*! Credentials stored as an MD5 sum */
   AST_SIP_AUTH_TYPE_MD5,
   /*! Google Oauth */
   AST_SIP_AUTH_TYPE_GOOGLE_OAUTH,
   /*! Credentials not stored this is a fake auth */
   AST_SIP_AUTH_TYPE_ARTIFICIAL
};

#define SIP_SORCERY_AUTH_TYPE "auth"

struct ast_sip_auth {
   /*! Sorcery ID of the auth is its name */
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Identification for these credentials */
      AST_STRING_FIELD(realm);
      /*! Authentication username */
      AST_STRING_FIELD(auth_user);
      /*! Authentication password */
      AST_STRING_FIELD(auth_pass);
      /*! Authentication credentials in MD5 format (hash of user:realm:pass) */
      AST_STRING_FIELD(md5_creds);
      /*! Refresh token to use for OAuth authentication */
      AST_STRING_FIELD(refresh_token);
      /*! Client ID to use for OAuth authentication */
      AST_STRING_FIELD(oauth_clientid);
      /*! Secret to use for OAuth authentication */
      AST_STRING_FIELD(oauth_secret);
   );
   /*! The time period (in seconds) that a nonce may be reused */
   unsigned int nonce_lifetime;
   /*! Used to determine what to use when authenticating */
   enum ast_sip_auth_type type;
};

AST_VECTOR(ast_sip_auth_vector, const char *);

/*!
 * \brief Different methods by which incoming requests can be matched to endpoints
 */
enum ast_sip_endpoint_identifier_type {
   /*! Identify based on user name in From header */
   AST_SIP_ENDPOINT_IDENTIFY_BY_USERNAME = (1 << 0),
   /*! Identify based on user name in Auth header first, then From header */
   AST_SIP_ENDPOINT_IDENTIFY_BY_AUTH_USERNAME = (1 << 1),
   /*! Identify based on source IP address */
   AST_SIP_ENDPOINT_IDENTIFY_BY_IP = (1 << 2),
   /*! Identify based on arbitrary headers */
   AST_SIP_ENDPOINT_IDENTIFY_BY_HEADER = (1 << 3),
};
AST_VECTOR(ast_sip_identify_by_vector, enum ast_sip_endpoint_identifier_type);

enum ast_sip_session_refresh_method {
   /*! Use reinvite to negotiate direct media */
   AST_SIP_SESSION_REFRESH_METHOD_INVITE,
   /*! Use UPDATE to negotiate direct media */
   AST_SIP_SESSION_REFRESH_METHOD_UPDATE,
};

enum ast_sip_direct_media_glare_mitigation {
   /*! Take no special action to mitigate reinvite glare */
   AST_SIP_DIRECT_MEDIA_GLARE_MITIGATION_NONE,
   /*! Do not send an initial direct media session refresh on outgoing call legs
    * Subsequent session refreshes will be sent no matter the session direction
    */
   AST_SIP_DIRECT_MEDIA_GLARE_MITIGATION_OUTGOING,
   /*! Do not send an initial direct media session refresh on incoming call legs
    * Subsequent session refreshes will be sent no matter the session direction
    */
   AST_SIP_DIRECT_MEDIA_GLARE_MITIGATION_INCOMING,
};

enum ast_sip_session_media_encryption {
   /*! Invalid media encryption configuration */
   AST_SIP_MEDIA_TRANSPORT_INVALID = 0,
   /*! Do not allow any encryption of session media */
   AST_SIP_MEDIA_ENCRYPT_NONE,
   /*! Offer SDES-encrypted session media */
   AST_SIP_MEDIA_ENCRYPT_SDES,
   /*! Offer encrypted session media with datagram TLS key exchange */
   AST_SIP_MEDIA_ENCRYPT_DTLS,
};

enum ast_sip_session_redirect {
   /*! User portion of the target URI should be used as the target in the dialplan */
   AST_SIP_REDIRECT_USER = 0,
   /*! Target URI should be used as the target in the dialplan */
   AST_SIP_REDIRECT_URI_CORE,
   /*! Target URI should be used as the target within chan_pjsip itself */
   AST_SIP_REDIRECT_URI_PJSIP,
};

/*!
 * \brief Incoming/Outgoing call offer/answer joint codec preference.
 *
 * The default is INTERSECT ALL LOCAL.
 */
enum ast_sip_call_codec_pref {
   /*! Two bits for merge */
   /*! Intersection of local and remote */
   AST_SIP_CALL_CODEC_PREF_INTERSECT = 1 << 0,
   /*! Union of local and remote */
   AST_SIP_CALL_CODEC_PREF_UNION =     1 << 1,

   /*! Two bits for filter */
   /*! No filter */
   AST_SIP_CALL_CODEC_PREF_ALL =    1 << 2,
   /*! Only the first */
   AST_SIP_CALL_CODEC_PREF_FIRST =  1 << 3,

   /*! Two bits for preference and sort   */
   /*! Prefer, and order by local values */
   AST_SIP_CALL_CODEC_PREF_LOCAL =  1 << 4,
   /*! Prefer, and order by remote values */
   AST_SIP_CALL_CODEC_PREF_REMOTE =    1 << 5,
};

/*!
 * \brief Returns true if the preference is set in the parameter
 * \since 18.0.0
 *
 * \param param A ast_flags struct with one or more of enum ast_sip_call_codec_pref set
 * \param codec_pref The last component of one of the enum values
 * \retval 1 if the enum value is set
 * \retval 0 if not
 */
#define ast_sip_call_codec_pref_test(__param, __codec_pref) (!!(ast_test_flag( &__param, AST_SIP_CALL_CODEC_PREF_ ## __codec_pref )))

/*!
 * \brief Session timers options
 */
struct ast_sip_timer_options {
   /*! Minimum session expiration period, in seconds */
   unsigned int min_se;
   /*! Session expiration period, in seconds */
   unsigned int sess_expires;
};

/*!
 * \brief Endpoint configuration for SIP extensions.
 *
 * SIP extensions, in this case refers to features
 * indicated in Supported or Required headers.
 */
struct ast_sip_endpoint_extensions {
   /*! Enabled SIP extensions */
   unsigned int flags;
   /*! Timer options */
   struct ast_sip_timer_options timer;
};

/*!
 * \brief Endpoint configuration for unsolicited MWI
 */
struct ast_sip_mwi_configuration {
   AST_DECLARE_STRING_FIELDS(
      /*! Configured voicemail boxes for this endpoint. Used for MWI */
      AST_STRING_FIELD(mailboxes);
      /*! Username to use when sending MWI NOTIFYs to this endpoint */
      AST_STRING_FIELD(fromuser);
   );
   /*! Should mailbox states be combined into a single notification? */
   unsigned int aggregate;
   /*! Should a subscribe replace unsolicited notifies? */
   unsigned int subscribe_replaces_unsolicited;
   /*! Voicemail extension to set in Message-Account */
   char *voicemail_extension;
};

/*!
 * \brief Endpoint subscription configuration
 */
struct ast_sip_endpoint_subscription_configuration {
   /*! Indicates if endpoint is allowed to initiate subscriptions */
   unsigned int allow;
   /*! The minimum allowed expiration for subscriptions from endpoint */
   unsigned int minexpiry;
   /*! Message waiting configuration */
   struct ast_sip_mwi_configuration mwi;
   /*! Context for SUBSCRIBE requests */
   char context[AST_MAX_CONTEXT];
};

/*!
 * \brief NAT configuration options for endpoints
 */
struct ast_sip_endpoint_nat_configuration {
   /*! Whether to force using the source IP address/port for sending responses */
   unsigned int force_rport;
   /*! Whether to rewrite the Contact header with the source IP address/port or not */
   unsigned int rewrite_contact;
};

/*!
 * \brief Party identification options for endpoints
 *
 * This includes caller ID, connected line, and redirecting-related options
 */
struct ast_sip_endpoint_id_configuration {
   struct ast_party_id self;
   /*! Do we accept identification information from this endpoint */
   unsigned int trust_inbound;
   /*! Do we send private identification information to this endpoint? */
   unsigned int trust_outbound;
   /*! Do we send P-Asserted-Identity headers to this endpoint? */
   unsigned int send_pai;
   /*! Do we send Remote-Party-ID headers to this endpoint? */
   unsigned int send_rpid;
   /*! Do we send messages for connected line updates for unanswered incoming calls immediately to this endpoint? */
   unsigned int rpid_immediate;
   /*! Do we add Diversion headers to applicable outgoing requests/responses? */
   unsigned int send_diversion;
   /*! Do we accept connected line updates from this endpoint? */
   unsigned int trust_connected_line;
   /*! Do we send connected line updates to this endpoint? */
   unsigned int send_connected_line;
   /*! When performing connected line update, which method should be used */
   enum ast_sip_session_refresh_method refresh_method;
   /*! Do we add History-Info headers to applicable outgoing requests/responses? */
   unsigned int send_history_info;
};

/*!
 * \brief Call pickup configuration options for endpoints
 */
struct ast_sip_endpoint_pickup_configuration {
   /*! Call group */
   ast_group_t callgroup;
   /*! Pickup group */
   ast_group_t pickupgroup;
   /*! Named call group */
   struct ast_namedgroups *named_callgroups;
   /*! Named pickup group */
   struct ast_namedgroups *named_pickupgroups;
};

/*!
 * \brief Configuration for one-touch INFO recording
 */
struct ast_sip_info_recording_configuration {
   AST_DECLARE_STRING_FIELDS(
      /*! Feature to enact when one-touch recording INFO with Record: On is received */
      AST_STRING_FIELD(onfeature);
      /*! Feature to enact when one-touch recording INFO with Record: Off is received */
      AST_STRING_FIELD(offfeature);
   );
   /*! Is one-touch recording permitted? */
   unsigned int enabled;
};

/*!
 * \brief Endpoint configuration options for INFO packages
 */
struct ast_sip_endpoint_info_configuration {
   /*! Configuration for one-touch recording */
   struct ast_sip_info_recording_configuration recording;
};

/*!
 * \brief RTP configuration for SIP endpoints
 */
struct ast_sip_media_rtp_configuration {
   AST_DECLARE_STRING_FIELDS(
      /*! Configured RTP engine for this endpoint. */
      AST_STRING_FIELD(engine);
   );
   /*! Whether IPv6 RTP is enabled or not */
   unsigned int ipv6;
   /*! Whether symmetric RTP is enabled or not */
   unsigned int symmetric;
   /*! Whether ICE support is enabled or not */
   unsigned int ice_support;
   /*! Whether to use the "ptime" attribute received from the endpoint or not */
   unsigned int use_ptime;
   /*! Do we use AVPF exclusively for this endpoint? */
   unsigned int use_avpf;
   /*! Do we force AVP, AVPF, SAVP, or SAVPF even for DTLS media streams? */
   unsigned int force_avp;
   /*! Do we use the received media transport in our answer SDP */
   unsigned int use_received_transport;
   /*! \brief DTLS-SRTP configuration information */
   struct ast_rtp_dtls_cfg dtls_cfg;
   /*! Should SRTP use a 32 byte tag instead of an 80 byte tag? */
   unsigned int srtp_tag_32;
   /*! Do we use media encryption? what type? */
   enum ast_sip_session_media_encryption encryption;
   /*! Do we want to optimistically support encryption if possible? */
   unsigned int encryption_optimistic;
   /*! Number of seconds between RTP keepalive packets */
   unsigned int keepalive;
   /*! Number of seconds before terminating channel due to lack of RTP (when not on hold) */
   unsigned int timeout;
   /*! Number of seconds before terminating channel due to lack of RTP (when on hold) */
   unsigned int timeout_hold;
   /*! Follow forked media with a different To tag */
   unsigned int follow_early_media_fork;
   /*! Accept updated SDPs on non-100rel 18X and 2XX responses with the same To tag */
   unsigned int accept_multiple_sdp_answers;
};

/*!
 * \brief Direct media options for SIP endpoints
 */
struct ast_sip_direct_media_configuration {
   /*! Boolean indicating if direct_media is permissible */
   unsigned int enabled;
   /*! When using direct media, which method should be used */
   enum ast_sip_session_refresh_method method;
   /*! Take steps to mitigate glare for direct media */
   enum ast_sip_direct_media_glare_mitigation glare_mitigation;
   /*! Do not attempt direct media session refreshes if a media NAT is detected */
   unsigned int disable_on_nat;
};

struct ast_sip_t38_configuration {
   /*! Whether T.38 UDPTL support is enabled or not */
   unsigned int enabled;
   /*! Error correction setting for T.38 UDPTL */
   enum ast_t38_ec_modes error_correction;
   /*! Explicit T.38 max datagram value, may be 0 to indicate the remote side can be trusted */
   unsigned int maxdatagram;
   /*! Whether NAT Support is enabled for T.38 UDPTL sessions or not */
   unsigned int nat;
   /*! Whether to use IPv6 for UDPTL or not */
   unsigned int ipv6;
};

/*!
 * \brief Media configuration for SIP endpoints
 */
struct ast_sip_endpoint_media_configuration {
   AST_DECLARE_STRING_FIELDS(
      /*! Optional media address to use in SDP */
      AST_STRING_FIELD(address);
      /*! SDP origin username */
      AST_STRING_FIELD(sdpowner);
      /*! SDP session name */
      AST_STRING_FIELD(sdpsession);
   );
   /*! RTP media configuration */
   struct ast_sip_media_rtp_configuration rtp;
   /*! Direct media options */
   struct ast_sip_direct_media_configuration direct_media;
   /*! T.38 (FoIP) options */
   struct ast_sip_t38_configuration t38;
   /*! Configured codecs */
   struct ast_format_cap *codecs;
   /*! Capabilities in topology form */
   struct ast_stream_topology *topology;
   /*! DSCP TOS bits for audio streams */
   unsigned int tos_audio;
   /*! Priority for audio streams */
   unsigned int cos_audio;
   /*! DSCP TOS bits for video streams */
   unsigned int tos_video;
   /*! Priority for video streams */
   unsigned int cos_video;
   /*! Is g.726 packed in a non standard way */
   unsigned int g726_non_standard;
   /*! Bind the RTP instance to the media_address */
   unsigned int bind_rtp_to_media_address;
   /*! Use RTCP-MUX */
   unsigned int rtcp_mux;
   /*! Maximum number of audio streams to offer/accept */
   unsigned int max_audio_streams;
   /*! Maximum number of video streams to offer/accept */
   unsigned int max_video_streams;
   /*! Use BUNDLE */
   unsigned int bundle;
   /*! Enable webrtc settings and defaults */
   unsigned int webrtc;
   /*! Codec preference for an incoming offer */
   struct ast_flags incoming_call_offer_pref;
   /*! Codec preference for an outgoing offer */
   struct ast_flags outgoing_call_offer_pref;
   /*! Codec negotiation prefs for incoming offers */
   struct ast_stream_codec_negotiation_prefs codec_prefs_incoming_offer;
   /*! Codec negotiation prefs for outgoing offers */
   struct ast_stream_codec_negotiation_prefs codec_prefs_outgoing_offer;
   /*! Codec negotiation prefs for incoming answers */
   struct ast_stream_codec_negotiation_prefs codec_prefs_incoming_answer;
   /*! Codec negotiation prefs for outgoing answers */
   struct ast_stream_codec_negotiation_prefs codec_prefs_outgoing_answer;
};

/*!
 * \brief An entity with which Asterisk communicates
 */
struct ast_sip_endpoint {
   SORCERY_OBJECT(details);
   AST_DECLARE_STRING_FIELDS(
      /*! Context to send incoming calls to */
      AST_STRING_FIELD(context);
      /*! Name of an explicit transport to use */
      AST_STRING_FIELD(transport);
      /*! Outbound proxy to use */
      AST_STRING_FIELD(outbound_proxy);
      /*! Explicit AORs to dial if none are specified */
      AST_STRING_FIELD(aors);
      /*! Musiconhold class to suggest that the other side use when placing on hold */
      AST_STRING_FIELD(mohsuggest);
      /*! Configured tone zone for this endpoint. */
      AST_STRING_FIELD(zone);
      /*! Configured language for this endpoint. */
      AST_STRING_FIELD(language);
      /*! Default username to place in From header */
      AST_STRING_FIELD(fromuser);
      /*! Domain to place in From header */
      AST_STRING_FIELD(fromdomain);
      /*! Context to route incoming MESSAGE requests to */
      AST_STRING_FIELD(message_context);
      /*! Accountcode to auto-set on channels */
      AST_STRING_FIELD(accountcode);
      /*! If set, we'll push incoming MWI NOTIFYs to stasis using this mailbox */
      AST_STRING_FIELD(incoming_mwi_mailbox);
   );
   /*! Configuration for extensions */
   struct ast_sip_endpoint_extensions extensions;
   /*! Configuration relating to media */
   struct ast_sip_endpoint_media_configuration media;
   /*! SUBSCRIBE/NOTIFY configuration options */
   struct ast_sip_endpoint_subscription_configuration subscription;
   /*! NAT configuration */
   struct ast_sip_endpoint_nat_configuration nat;
   /*! Party identification options */
   struct ast_sip_endpoint_id_configuration id;
   /*! Configuration options for INFO packages */
   struct ast_sip_endpoint_info_configuration info;
   /*! Call pickup configuration */
   struct ast_sip_endpoint_pickup_configuration pickup;
   /*! Inbound authentication credentials */
   struct ast_sip_auth_vector inbound_auths;
   /*! Outbound authentication credentials */
   struct ast_sip_auth_vector outbound_auths;
   /*! DTMF mode to use with this endpoint */
   enum ast_sip_dtmf_mode dtmf;
   /*! Method(s) by which the endpoint should be identified. */
   enum ast_sip_endpoint_identifier_type ident_method;
   /*! Order of the method(s) by which the endpoint should be identified. */
   struct ast_sip_identify_by_vector ident_method_order;
   /*! Boolean indicating if ringing should be sent as inband progress */
   unsigned int inband_progress;
   /*! Pointer to the persistent Asterisk endpoint */
   struct ast_endpoint *persistent;
   /*! The number of channels at which busy device state is returned */
   unsigned int devicestate_busy_at;
   /*! Whether fax detection is enabled or not (CNG tone detection) */
   unsigned int faxdetect;
   /*! Determines if transfers (using REFER) are allowed by this endpoint */
   unsigned int allowtransfer;
   /*! Method used when handling redirects */
   enum ast_sip_session_redirect redirect_method;
   /*! Variables set on channel creation */
   struct ast_variable *channel_vars;
   /*! Whether to place a 'user=phone' parameter into the request URI if user is a number */
   unsigned int usereqphone;
   /*! Whether to pass through hold and unhold using re-invites with recvonly and sendrecv */
   unsigned int moh_passthrough;
   /*! Access control list */
   struct ast_acl_list *acl;
   /*! Restrict what IPs are allowed in the Contact header (for registration) */
   struct ast_acl_list *contact_acl;
   /*! The number of seconds into call to disable fax detection.  (0 = disabled) */
   unsigned int faxdetect_timeout;
   /*! Override the user on the outgoing Contact header with this value. */
   char *contact_user;
   /*! Whether to response SDP offer with single most preferred codec. */
   unsigned int preferred_codec_only;
   /*! Do we allow an asymmetric RTP codec? */
   unsigned int asymmetric_rtp_codec;
   /*! Do we allow overlap dialling? */
   unsigned int allow_overlap;
   /*! Whether to notifies all the progress details on blind transfer */
   unsigned int refer_blind_progress;
   /*! Whether to notifies dialog-info 'early' on INUSE && RINGING state */
   unsigned int notify_early_inuse_ringing;
   /*! Suppress Q.850 Reason headers on this endpoint */
   unsigned int suppress_q850_reason_headers;
   /*! Ignore 183 if no SDP is present */
   unsigned int ignore_183_without_sdp;
   /*! Enable STIR/SHAKEN support on this endpoint */
   unsigned int stir_shaken;
   /*! Should we authenticate OPTIONS requests per RFC 3261? */
   unsigned int allow_unauthenticated_options;
};

/*! URI parameter for symmetric transport */
#define AST_SIP_X_AST_TXP "x-ast-txp"
#define AST_SIP_X_AST_TXP_LEN 9

/*!
 * \brief Initialize an auth vector with the configured values.
 *
 * \param vector Vector to initialize
 * \param auth_names Comma-separated list of names to set in the array
 * \retval 0 Success
 * \retval non-zero Failure
 */
int ast_sip_auth_vector_init(struct ast_sip_auth_vector *vector, const char *auth_names);

/*!
 * \brief Free contents of an auth vector.
 *
 * \param array Vector whose contents are to be freed
 */
void ast_sip_auth_vector_destroy(struct ast_sip_auth_vector *vector);

/*!
 * \brief Possible returns from ast_sip_check_authentication
 */
enum ast_sip_check_auth_result {
    /*! Authentication needs to be challenged */
    AST_SIP_AUTHENTICATION_CHALLENGE,
    /*! Authentication succeeded */
    AST_SIP_AUTHENTICATION_SUCCESS,
    /*! Authentication failed */
    AST_SIP_AUTHENTICATION_FAILED,
    /*! Authentication encountered some internal error */
    AST_SIP_AUTHENTICATION_ERROR,
};

/*!
 * \brief An interchangeable way of handling digest authentication for SIP.
 *
 * An authenticator is responsible for filling in the callbacks provided below. Each is called from a publicly available
 * function in res_sip. The authenticator can use configuration or other local policy to determine whether authentication
 * should take place and what credentials should be used when challenging and authenticating a request.
 */
struct ast_sip_authenticator {
    /*!
     * \brief Check if a request requires authentication
     * See ast_sip_requires_authentication for more details
     */
    int (*requires_authentication)(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);
   /*!
    * \brief Check that an incoming request passes authentication.
    *
    * The tdata parameter is useful for adding information such as digest challenges.
    *
    * \param endpoint The endpoint sending the incoming request
    * \param rdata The incoming request
    * \param tdata Tentative outgoing request.
    */
   enum ast_sip_check_auth_result (*check_authentication)(struct ast_sip_endpoint *endpoint,
         pjsip_rx_data *rdata, pjsip_tx_data *tdata);
};

/*!
 * \brief an interchangeable way of responding to authentication challenges
 *
 * An outbound authenticator takes incoming challenges and formulates a new SIP request with
 * credentials.
 */
struct ast_sip_outbound_authenticator {
   /*!
    * \brief Create a new request with authentication credentials
    *
    * \param auths A vector of IDs of auth sorcery objects
    * \param challenge The SIP response with authentication challenge(s)
    * \param old_request The request that received the auth challenge(s)
    * \param new_request The new SIP request with challenge response(s)
    * \retval 0 Successfully created new request
    * \retval -1 Failed to create a new request
    */
   int (*create_request_with_auth)(const struct ast_sip_auth_vector *auths, struct pjsip_rx_data *challenge,
         struct pjsip_tx_data *old_request, struct pjsip_tx_data **new_request);
};

/*!
 * \brief An entity responsible for identifying the source of a SIP message
 */
struct ast_sip_endpoint_identifier {
    /*!
     * \brief Callback used to identify the source of a message.
     * See ast_sip_identify_endpoint for more details
     */
    struct ast_sip_endpoint *(*identify_endpoint)(pjsip_rx_data *rdata);
};

/*!
 * \brief Contact retrieval filtering flags
 */
enum ast_sip_contact_filter {
   /*! \brief Default filter flags */
   AST_SIP_CONTACT_FILTER_DEFAULT = 0,

   /*! \brief Return only reachable or unknown contacts */
   AST_SIP_CONTACT_FILTER_REACHABLE = (1 << 0),
};

/*!
 * \brief Adds a Date header to the tdata, formatted like:
 * Date: Wed, 01 Jan 2021 14:53:01 GMT
 * \since 16.19.0
 *
 * \note There is no checking done to see if the header already exists
 * before adding it. It's up to the caller of this function to determine
 * if that needs to be done or not.
 */
void ast_sip_add_date_header(pjsip_tx_data *tdata);

/*!
 * \brief Register a SIP service in Asterisk.
 *
 * This is more-or-less a wrapper around pjsip_endpt_register_module().
 * Registering a service makes it so that PJSIP will call into the
 * service at appropriate times. For more information about PJSIP module
 * callbacks, see the PJSIP documentation. Asterisk modules that call
 * this function will likely do so at module load time.
 *
 * \param module The module that is to be registered with PJSIP
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_register_service(pjsip_module *module);

/*!
 * This is the opposite of ast_sip_register_service().  Unregistering a
 * service means that PJSIP will no longer call into the module any more.
 * This will likely occur when an Asterisk module is unloaded.
 *
 * \param module The PJSIP module to unregister
 */
void ast_sip_unregister_service(pjsip_module *module);

/*!
 * \brief Register a SIP authenticator
 *
 * An authenticator has three main purposes:
 * 1) Determining if authentication should be performed on an incoming request
 * 2) Gathering credentials necessary for issuing an authentication challenge
 * 3) Authenticating a request that has credentials
 *
 * Asterisk provides a default authenticator, but it may be replaced by a
 * custom one if desired.
 *
 * \param auth The authenticator to register
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_register_authenticator(struct ast_sip_authenticator *auth);

/*!
 * \brief Unregister a SIP authenticator
 *
 * When there is no authenticator registered, requests cannot be challenged
 * or authenticated.
 *
 * \param auth The authenticator to unregister
 */
void ast_sip_unregister_authenticator(struct ast_sip_authenticator *auth);

 /*!
 * \brief Register an outbound SIP authenticator
 *
 * An outbound authenticator is responsible for creating responses to
 * authentication challenges by remote endpoints.
 *
 * \param auth The authenticator to register
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_register_outbound_authenticator(struct ast_sip_outbound_authenticator *outbound_auth);

/*!
 * \brief Unregister an outbound SIP authenticator
 *
 * When there is no outbound authenticator registered, authentication challenges
 * will be handled as any other final response would be.
 *
 * \param auth The authenticator to unregister
 */
void ast_sip_unregister_outbound_authenticator(struct ast_sip_outbound_authenticator *auth);

/*!
 * \brief Register a SIP endpoint identifier with a name.
 *
 * An endpoint identifier's purpose is to determine which endpoint a given SIP
 * message has come from.
 *
 * Multiple endpoint identifiers may be registered so that if an endpoint
 * cannot be identified by one identifier, it may be identified by another.
 *
 * \param identifier The SIP endpoint identifier to register
 * \param name The name of the endpoint identifier
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_register_endpoint_identifier_with_name(struct ast_sip_endpoint_identifier *identifier,
                     const char *name);

/*!
 * \brief Register a SIP endpoint identifier
 *
 * An endpoint identifier's purpose is to determine which endpoint a given SIP
 * message has come from.
 *
 * Multiple endpoint identifiers may be registered so that if an endpoint
 * cannot be identified by one identifier, it may be identified by another.
 *
 * Asterisk provides two endpoint identifiers. One identifies endpoints based
 * on the user part of the From header URI. The other identifies endpoints based
 * on the source IP address.
 *
 * If the order in which endpoint identifiers is run is important to you, then
 * be sure to load individual endpoint identifier modules in the order you wish
 * for them to be run in modules.conf
 *
 * \note endpoint identifiers registered using this method (no name specified)
 *       are placed at the front of the endpoint identifiers list ahead of any
 *       named identifiers.
 *
 * \param identifier The SIP endpoint identifier to register
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_register_endpoint_identifier(struct ast_sip_endpoint_identifier *identifier);

/*!
 * \brief Unregister a SIP endpoint identifier
 *
 * This stops an endpoint identifier from being used.
 *
 * \param identifier The SIP endoint identifier to unregister
 */
void ast_sip_unregister_endpoint_identifier(struct ast_sip_endpoint_identifier *identifier);

/*!
 * \brief Allocate a new SIP endpoint
 *
 * This will return an endpoint with its refcount increased by one. This reference
 * can be released using ao2_ref().
 *
 * \param name The name of the endpoint.
 * \retval NULL Endpoint allocation failed
 * \retval non-NULL The newly allocated endpoint
 */
void *ast_sip_endpoint_alloc(const char *name);

/*!
 * \brief Change state of a persistent endpoint.
 *
 * \param endpoint_name The SIP endpoint name to change state.
 * \param state The new state
 * \retval 0 Success
 * \retval -1 Endpoint not found
 */
int ast_sip_persistent_endpoint_update_state(const char *endpoint_name, enum ast_endpoint_state state);

/*!
 * \brief Publish the change of state for a contact.
 *
 * \param endpoint_name The SIP endpoint name.
 * \param contact_status The contact status.
 */
void ast_sip_persistent_endpoint_publish_contact_state(const char *endpoint_name, const struct ast_sip_contact_status *contact_status);

/*!
 * \brief Retrieve the current status for a contact.
 *
 * \param contact The contact.
 *
 * \retval non-NULL Success
 * \retval NULL Status information not found
 *
 * \note The returned contact status object is immutable.
 */
struct ast_sip_contact_status *ast_sip_get_contact_status(const struct ast_sip_contact *contact);

/*!
 * \brief Get a pointer to the PJSIP endpoint.
 *
 * This is useful when modules have specific information they need
 * to register with the PJSIP core.
 * \retval NULL endpoint has not been created yet.
 * \retval non-NULL PJSIP endpoint.
 */
pjsip_endpoint *ast_sip_get_pjsip_endpoint(void);

/*!
 * \brief Get a pointer to the SIP sorcery structure.
 *
 * \retval NULL sorcery has not been initialized
 * \retval non-NULL sorcery structure
 */
struct ast_sorcery *ast_sip_get_sorcery(void);

/*!
 * \brief Retrieve a named AOR
 *
 * \param aor_name Name of the AOR
 *
 * \retval NULL if not found
 * \retval non-NULL if found
 */
struct ast_sip_aor *ast_sip_location_retrieve_aor(const char *aor_name);

/*!
 * \brief Retrieve the first bound contact for an AOR
 *
 * \param aor Pointer to the AOR
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 */
struct ast_sip_contact *ast_sip_location_retrieve_first_aor_contact(const struct ast_sip_aor *aor);

/*!
 * \brief Retrieve the first bound contact for an AOR and filter based on flags
 * \since 13.16.0
 *
 * \param aor Pointer to the AOR
 * \param flags Filtering flags
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 */
struct ast_sip_contact *ast_sip_location_retrieve_first_aor_contact_filtered(const struct ast_sip_aor *aor,
   unsigned int flags);

/*!
 * \brief Retrieve all contacts currently available for an AOR
 *
 * \param aor Pointer to the AOR
 *
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 *
 * \warning
 * Since this function prunes expired contacts before returning, it holds a named write
 * lock on the aor.  If you already hold the lock, call ast_sip_location_retrieve_aor_contacts_nolock instead.
 */
struct ao2_container *ast_sip_location_retrieve_aor_contacts(const struct ast_sip_aor *aor);

/*!
 * \brief Retrieve all contacts currently available for an AOR and filter based on flags
 * \since 13.16.0
 *
 * \param aor Pointer to the AOR
 * \param flags Filtering flags
 *
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 *
 * \warning
 * Since this function prunes expired contacts before returning, it holds a named write
 * lock on the aor.  If you already hold the lock, call ast_sip_location_retrieve_aor_contacts_nolock instead.
 */
struct ao2_container *ast_sip_location_retrieve_aor_contacts_filtered(const struct ast_sip_aor *aor,
   unsigned int flags);

/*!
 * \brief Retrieve all contacts currently available for an AOR without locking the AOR
 * \since 13.9.0
 *
 * \param aor Pointer to the AOR
 *
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 *
 * \warning
 * This function should only be called if you already hold a named write lock on the aor.
 */
struct ao2_container *ast_sip_location_retrieve_aor_contacts_nolock(const struct ast_sip_aor *aor);

/*!
 * \brief Retrieve all contacts currently available for an AOR without locking the AOR and filter based on flags
 * \since 13.16.0
 *
 * \param aor Pointer to the AOR
 * \param flags Filtering flags
 *
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 *
 * \warning
 * This function should only be called if you already hold a named write lock on the aor.
 */
struct ao2_container *ast_sip_location_retrieve_aor_contacts_nolock_filtered(const struct ast_sip_aor *aor,
   unsigned int flags);

/*!
 * \brief Retrieve the first bound contact from a list of AORs
 *
 * \param aor_list A comma-separated list of AOR names
 * \retval NULL if no contacts available
 * \retval non-NULL if contacts available
 */
struct ast_sip_contact *ast_sip_location_retrieve_contact_from_aor_list(const char *aor_list);

/*!
 * \brief Retrieve all contacts from a list of AORs
 *
 * \param aor_list A comma-separated list of AOR names
 * \retval NULL if no contacts available
 * \retval non-NULL container (which must be freed) if contacts available
 */
struct ao2_container *ast_sip_location_retrieve_contacts_from_aor_list(const char *aor_list);

/*!
 * \brief Retrieve the first bound contact AND the AOR chosen from a list of AORs
 *
 * \param aor_list A comma-separated list of AOR names
 * \param aor The chosen AOR
 * \param contact The chosen contact
 */
 void ast_sip_location_retrieve_contact_and_aor_from_list(const char *aor_list, struct ast_sip_aor **aor,
   struct ast_sip_contact **contact);

/*!
 * \brief Retrieve the first bound contact AND the AOR chosen from a list of AORs and filter based on flags
 * \since 13.16.0
 *
 * \param aor_list A comma-separated list of AOR names
 * \param flags Filtering flags
 * \param aor The chosen AOR
 * \param contact The chosen contact
 */
void ast_sip_location_retrieve_contact_and_aor_from_list_filtered(const char *aor_list, unsigned int flags,
   struct ast_sip_aor **aor, struct ast_sip_contact **contact);

/*!
 * \brief Retrieve a named contact
 *
 * \param contact_name Name of the contact
 *
 * \retval NULL if not found
 * \retval non-NULL if found
 */
struct ast_sip_contact *ast_sip_location_retrieve_contact(const char *contact_name);

/*!
 * \brief Add a new contact to an AOR
 *
 * \param aor Pointer to the AOR
 * \param uri Full contact URI
 * \param expiration_time Optional expiration time of the contact
 * \param path_info Path information
 * \param user_agent User-Agent header from REGISTER request
 * \param via_addr
 * \param via_port
 * \param call_id
 * \param endpoint The endpoint that resulted in the contact being added
 *
 * \retval -1 failure
 * \retval 0 success
 *
 * \warning
 * This function holds a named write lock on the aor.  If you already hold the lock
 * you should call ast_sip_location_add_contact_nolock instead.
 */
int ast_sip_location_add_contact(struct ast_sip_aor *aor, const char *uri,
   struct timeval expiration_time, const char *path_info, const char *user_agent,
   const char *via_addr, int via_port, const char *call_id,
   struct ast_sip_endpoint *endpoint);

/*!
 * \brief Add a new contact to an AOR without locking the AOR
 * \since 13.9.0
 *
 * \param aor Pointer to the AOR
 * \param uri Full contact URI
 * \param expiration_time Optional expiration time of the contact
 * \param path_info Path information
 * \param user_agent User-Agent header from REGISTER request
 * \param via_addr
 * \param via_port
 * \param call_id
 * \param endpoint The endpoint that resulted in the contact being added
 *
 * \retval -1 failure
 * \retval 0 success
 *
 * \warning
 * This function should only be called if you already hold a named write lock on the aor.
 */
int ast_sip_location_add_contact_nolock(struct ast_sip_aor *aor, const char *uri,
   struct timeval expiration_time, const char *path_info, const char *user_agent,
   const char *via_addr, int via_port, const char *call_id,
   struct ast_sip_endpoint *endpoint);

/*!
 * \brief Create a new contact for an AOR without locking the AOR
 * \since 13.18.0
 *
 * \param aor Pointer to the AOR
 * \param uri Full contact URI
 * \param expiration_time Optional expiration time of the contact
 * \param path_info Path information
 * \param user_agent User-Agent header from REGISTER request
 * \param via_addr
 * \param via_port
 * \param call_id
 * \param prune_on_boot Non-zero if the contact cannot survive a restart/boot.
 * \param endpoint The endpoint that resulted in the contact being added
 *
 * \return The created contact or NULL on failure.
 *
 * \warning
 * This function should only be called if you already hold a named write lock on the aor.
 */
struct ast_sip_contact *ast_sip_location_create_contact(struct ast_sip_aor *aor,
   const char *uri, struct timeval expiration_time, const char *path_info,
   const char *user_agent, const char *via_addr, int via_port, const char *call_id,
   int prune_on_boot, struct ast_sip_endpoint *endpoint);

/*!
 * \brief Update a contact
 *
 * \param contact New contact object with details
 *
 * \retval -1 failure
 * \retval 0 success
 */
int ast_sip_location_update_contact(struct ast_sip_contact *contact);

/*!
* \brief Delete a contact
*
* \param contact Contact object to delete
*
* \retval -1 failure
* \retval 0 success
*/
int ast_sip_location_delete_contact(struct ast_sip_contact *contact);

/*!
 * \brief Prune the prune_on_boot contacts
 * \since 13.18.0
 */
void ast_sip_location_prune_boot_contacts(void);

/*!
 * \brief Callback called when an outbound request with authentication credentials is to be sent in dialog
 *
 * This callback will have the created request on it. The callback's purpose is to do any extra
 * housekeeping that needs to be done as well as to send the request out.
 *
 * This callback is only necessary if working with a PJSIP API that sits between the application
 * and the dialog layer.
 *
 * \param dlg The dialog to which the request belongs
 * \param tdata The created request to be sent out
 * \param user_data Data supplied with the callback
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
typedef int (*ast_sip_dialog_outbound_auth_cb)(pjsip_dialog *dlg, pjsip_tx_data *tdata, void *user_data);

/*!
 * \brief Set up outbound authentication on a SIP dialog
 *
 * This sets up the infrastructure so that all requests associated with a created dialog
 * can be re-sent with authentication credentials if the original request is challenged.
 *
 * \param dlg The dialog on which requests will be authenticated
 * \param endpoint The endpoint whom this dialog pertains to
 * \param cb Callback to call to send requests with authentication
 * \param user_data Data to be provided to the callback when it is called
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_dialog_setup_outbound_authentication(pjsip_dialog *dlg, const struct ast_sip_endpoint *endpoint,
      ast_sip_dialog_outbound_auth_cb cb, void *user_data);

/*!
 * \brief Retrieves a reference to the artificial auth.
 *
 * \retval The artificial auth
 */
struct ast_sip_auth *ast_sip_get_artificial_auth(void);

/*!
 * \brief Retrieves a reference to the artificial endpoint.
 *
 * \retval The artificial endpoint
 */
struct ast_sip_endpoint *ast_sip_get_artificial_endpoint(void);

/*! \defgroup pjsip_threading PJSIP Threading Model
 * @{
 * \page PJSIP PJSIP Threading Model
 *
 * There are three major types of threads that SIP will have to deal with:
 * \li Asterisk threads
 * \li PJSIP threads
 * \li SIP threadpool threads (a.k.a. "servants")
 *
 * \par Asterisk Threads
 *
 * Asterisk threads are those that originate from outside of SIP but within
 * Asterisk. The most common of these threads are PBX (channel) threads and
 * the autoservice thread. Most interaction with these threads will be through
 * channel technology callbacks. Within these threads, it is fine to handle
 * Asterisk data from outside of SIP, but any handling of SIP data should be
 * left to servants, \b especially if you wish to call into PJSIP for anything.
 * Asterisk threads are not registered with PJLIB, so attempting to call into
 * PJSIP will cause an assertion to be triggered, thus causing the program to
 * crash.
 *
 * \par PJSIP Threads
 *
 * PJSIP threads are those that originate from handling of PJSIP events, such
 * as an incoming SIP request or response, or a transaction timeout. The role
 * of these threads is to process information as quickly as possible so that
 * the next item on the SIP socket(s) can be serviced. On incoming messages,
 * Asterisk automatically will push the request to a servant thread. When your
 * module callback is called, processing will already be in a servant. However,
 * for other PJSIP events, such as transaction state changes due to timer
 * expirations, your module will be called into from a PJSIP thread. If you
 * are called into from a PJSIP thread, then you should push whatever processing
 * is needed to a servant as soon as possible. You can discern if you are currently
 * in a SIP servant thread using the \ref ast_sip_thread_is_servant function.
 *
 * \par Servants
 *
 * Servants are where the bulk of SIP work should be performed. These threads
 * exist in order to do the work that Asterisk threads and PJSIP threads hand
 * off to them. Servant threads register themselves with PJLIB, meaning that
 * they are capable of calling PJSIP and PJLIB functions if they wish.
 *
 * \par Serializer
 *
 * Tasks are handed off to servant threads using the API call \ref ast_sip_push_task.
 * The first parameter of this call is a serializer. If this pointer
 * is NULL, then the work will be handed off to whatever servant can currently handle
 * the task. If this pointer is non-NULL, then the task will not be executed until
 * previous tasks pushed with the same serializer have completed. For more information
 * on serializers and the benefits they provide, see \ref ast_threadpool_serializer
 *
 * \par Scheduler
 *
 * Some situations require that a task run periodically or at a future time.  Normally
 * the ast_sched functionality would be used but ast_sched only uses 1 thread for all
 * tasks and that thread isn't registered with PJLIB and therefore can't do any PJSIP
 * related work.
 *
 * ast_sip_sched uses ast_sched only as a scheduled queue.  When a task is ready to run,
 * it's pushed to a Serializer to be invoked asynchronously by a Servant.  This ensures
 * that the task is executed in a PJLIB registered thread and allows the ast_sched thread
 * to immediately continue processing the queue.  The Serializer used by ast_sip_sched
 * is one of your choosing or a random one from the res_pjsip pool if you don't choose one.
 *
 * \note
 *
 * Do not make assumptions about individual threads based on a corresponding serializer.
 * In other words, just because several tasks use the same serializer when being pushed
 * to servants, it does not mean that the same thread is necessarily going to execute those
 * tasks, even though they are all guaranteed to be executed in sequence.
 */

typedef int (*ast_sip_task)(void *user_data);

/*!
 * \brief Create a new serializer for SIP tasks
 * \since 13.8.0
 *
 * See \ref ast_threadpool_serializer for more information on serializers.
 * SIP creates serializers so that tasks operating on similar data will run
 * in sequence.
 *
 * \param name Name of the serializer. (must be unique)
 *
 * \retval NULL Failure
 * \retval non-NULL Newly-created serializer
 */
struct ast_taskprocessor *ast_sip_create_serializer(const char *name);

struct ast_serializer_shutdown_group;

/*!
 * \brief Create a new serializer for SIP tasks
 * \since 13.8.0
 *
 * See \ref ast_threadpool_serializer for more information on serializers.
 * SIP creates serializers so that tasks operating on similar data will run
 * in sequence.
 *
 * \param name Name of the serializer. (must be unique)
 * \param shutdown_group Group shutdown controller. (NULL if no group association)
 *
 * \retval NULL Failure
 * \retval non-NULL Newly-created serializer
 */
struct ast_taskprocessor *ast_sip_create_serializer_group(const char *name, struct ast_serializer_shutdown_group *shutdown_group);

/*!
 * \brief Determine the distributor serializer for the SIP message.
 * \since 13.10.0
 *
 * \param rdata The incoming message.
 *
 * \retval Calculated distributor serializer on success.
 * \retval NULL on error.
 */
struct ast_taskprocessor *ast_sip_get_distributor_serializer(pjsip_rx_data *rdata);

/*!
 * \brief Set a serializer on a SIP dialog so requests and responses are automatically serialized
 *
 * Passing a NULL serializer is a way to remove a serializer from a dialog.
 *
 * \param dlg The SIP dialog itself
 * \param serializer The serializer to use
 */
void ast_sip_dialog_set_serializer(pjsip_dialog *dlg, struct ast_taskprocessor *serializer);

/*!
 * \brief Set an endpoint on a SIP dialog so in-dialog requests do not undergo endpoint lookup.
 *
 * \param dlg The SIP dialog itself
 * \param endpoint The endpoint that this dialog is communicating with
 */
void ast_sip_dialog_set_endpoint(pjsip_dialog *dlg, struct ast_sip_endpoint *endpoint);

/*!
 * \brief Get the endpoint associated with this dialog
 *
 * This function increases the refcount of the endpoint by one. Release
 * the reference once you are finished with the endpoint.
 *
 * \param dlg The SIP dialog from which to retrieve the endpoint
 * \retval NULL No endpoint associated with this dialog
 * \retval non-NULL The endpoint.
 */
struct ast_sip_endpoint *ast_sip_dialog_get_endpoint(pjsip_dialog *dlg);

/*!
 * \brief Pushes a task to SIP servants
 *
 * This uses the serializer provided to determine how to push the task.
 * If the serializer is NULL, then the task will be pushed to the
 * servants directly. If the serializer is non-NULL, then the task will be
 * queued behind other tasks associated with the same serializer.
 *
 * \param serializer The serializer to which the task belongs. Can be NULL
 * \param sip_task The task to execute
 * \param task_data The parameter to pass to the task when it executes
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_push_task(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data);

/*!
 * \brief Push a task to SIP servants and wait for it to complete.
 *
 * Like \ref ast_sip_push_task except that it blocks until the task
 * completes.  If the current thread is a SIP servant thread then the
 * task executes immediately.  Otherwise, the specified serializer
 * executes the task and the current thread waits for it to complete.
 *
 * \note PJPROJECT callbacks tend to have locks already held when
 * called.
 *
 * \warning \b Never hold locks that may be acquired by a SIP servant
 * thread when calling this function.  Doing so may cause a deadlock
 * if all SIP servant threads are blocked waiting to acquire the lock
 * while the thread holding the lock is waiting for a free SIP servant
 * thread.
 *
 * \warning \b Use of this function in an ao2 destructor callback is a
 * bad idea.  You don't have control over which thread executes the
 * destructor.  Attempting to shift execution to another thread with
 * this function is likely to cause deadlock.
 *
 * \param serializer The SIP serializer to execute the task if the
 * current thread is not a SIP servant.  NULL if any of the default
 * serializers can be used.
 * \param sip_task The task to execute
 * \param task_data The parameter to pass to the task when it executes
 *
 * \note The sip_task() return value may need to be distinguished from
 * the failure to push the task.
 *
 * \return sip_task() return value on success.
 * \retval -1 Failure to push the task.
 */
int ast_sip_push_task_wait_servant(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data);

/*!
 * \brief Push a task to SIP servants and wait for it to complete.
 * \deprecated Replaced with ast_sip_push_task_wait_servant().
 */
int ast_sip_push_task_synchronous(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data);

/*!
 * \brief Push a task to the serializer and wait for it to complete.
 *
 * Like \ref ast_sip_push_task except that it blocks until the task is
 * completed by the specified serializer.  If the specified serializer
 * is the current thread then the task executes immediately.
 *
 * \note PJPROJECT callbacks tend to have locks already held when
 * called.
 *
 * \warning \b Never hold locks that may be acquired by a SIP servant
 * thread when calling this function.  Doing so may cause a deadlock
 * if all SIP servant threads are blocked waiting to acquire the lock
 * while the thread holding the lock is waiting for a free SIP servant
 * thread for the serializer to execute in.
 *
 * \warning \b Never hold locks that may be acquired by the serializer
 * when calling this function.  Doing so will cause a deadlock.
 *
 * \warning \b Never use this function in the pjsip monitor thread (It
 * is a SIP servant thread).  This is likely to cause a deadlock.
 *
 * \warning \b Use of this function in an ao2 destructor callback is a
 * bad idea.  You don't have control over which thread executes the
 * destructor.  Attempting to shift execution to another thread with
 * this function is likely to cause deadlock.
 *
 * \param serializer The SIP serializer to execute the task.  NULL if
 * any of the default serializers can be used.
 * \param sip_task The task to execute
 * \param task_data The parameter to pass to the task when it executes
 *
 * \note It is generally better to call
 * ast_sip_push_task_wait_servant() if you pass NULL for the
 * serializer parameter.
 *
 * \note The sip_task() return value may need to be distinguished from
 * the failure to push the task.
 *
 * \return sip_task() return value on success.
 * \retval -1 Failure to push the task.
 */
int ast_sip_push_task_wait_serializer(struct ast_taskprocessor *serializer, int (*sip_task)(void *), void *task_data);

/*!
 * \brief Determine if the current thread is a SIP servant thread
 *
 * \retval 0 This is not a SIP servant thread
 * \retval 1 This is a SIP servant thread
 */
int ast_sip_thread_is_servant(void);

/*!
 * \brief Task flags for the res_pjsip scheduler
 *
 * The default is AST_SIP_SCHED_TASK_FIXED
 *                | AST_SIP_SCHED_TASK_DATA_NOT_AO2
 *                | AST_SIP_SCHED_TASK_DATA_NO_CLEANUP
 *                | AST_SIP_SCHED_TASK_PERIODIC
 */
enum ast_sip_scheduler_task_flags {
   /*!
    * The defaults
    */
   AST_SIP_SCHED_TASK_DEFAULTS = (0 << 0),

   /*!
    * Run at a fixed interval.
    * Stop scheduling if the callback returns <= 0.
    * Any other value is ignored.
    */
   AST_SIP_SCHED_TASK_FIXED = (0 << 0),
   /*!
    * Run at a variable interval.
    * Stop scheduling if the callback returns <= 0.
    * Any other return value is used as the new interval.
    */
   AST_SIP_SCHED_TASK_VARIABLE = (1 << 0),

   /*!
    * Run just once.
    * Return values are ignored.
    */
   AST_SIP_SCHED_TASK_ONESHOT = (1 << 6),

   /*!
    * The task data is not an AO2 object.
    */
   AST_SIP_SCHED_TASK_DATA_NOT_AO2 = (0 << 1),
   /*!
    * The task data is an AO2 object.
    * A reference count will be held by the scheduler until
    * after the task has run for the final time (if ever).
    */
   AST_SIP_SCHED_TASK_DATA_AO2 = (1 << 1),

   /*!
    * Don't take any cleanup action on the data
    */
   AST_SIP_SCHED_TASK_DATA_NO_CLEANUP = (0 << 3),
   /*!
    * If AST_SIP_SCHED_TASK_DATA_AO2 is set, decrement the reference count
    * otherwise call ast_free on it.
    */
   AST_SIP_SCHED_TASK_DATA_FREE = ( 1 << 3 ),

   /*!
    * \brief The task is scheduled at multiples of interval
    * \see Interval
    */
   AST_SIP_SCHED_TASK_PERIODIC = (0 << 4),
   /*!
    * \brief The next invocation of the task is at last finish + interval
    * \see Interval
    */
   AST_SIP_SCHED_TASK_DELAY = (1 << 4),
   /*!
    * \brief The scheduled task's events are tracked in the debug log.
    * \details
    * Schedule events such as scheduling, running, rescheduling, canceling,
    * and destroying are logged about the task.
    */
   AST_SIP_SCHED_TASK_TRACK = (1 << 5),
};

/*!
 * \brief Scheduler task data structure
 */
struct ast_sip_sched_task;

/*!
 * \brief Schedule a task to run in the res_pjsip thread pool
 * \since 13.9.0
 *
 * \param serializer The serializer to use.  If NULL, don't use a serializer (see note below)
 * \param interval The invocation interval in milliseconds (see note below)
 * \param sip_task The task to invoke
 * \param name An optional name to associate with the task
 * \param task_data Optional data to pass to the task
 * \param flags One of enum ast_sip_scheduler_task_type
 *
 * \returns Pointer to \ref ast_sip_sched_task ao2 object which must be dereferenced when done.
 *
 * \paragraph Serialization
 *
 * Specifying a serializer guarantees serialized execution but NOT specifying a serializer
 * may still result in tasks being effectively serialized if the thread pool is busy.
 * The point of the serializer BTW is not to prevent parallel executions of the SAME task.
 * That happens automatically (see below).  It's to prevent the task from running at the same
 * time as other work using the same serializer, whether or not it's being run by the scheduler.
 *
 * \paragraph Interval
 *
 * The interval is used to calculate the next time the task should run.  There are two models.
 *
 * \ref AST_SIP_SCHED_TASK_PERIODIC specifies that the invocations of the task occur at the
 * specific interval.  That is, every \ref "interval" milliseconds, regardless of how long the task
 * takes. If the task takes longer than \ref interval, it will be scheduled at the next available
 * multiple of \ref interval.  For exmaple: If the task has an interval of 60 seconds and the task
 * takes 70 seconds, the next invocation will happen at 120 seconds.
 *
 * \ref AST_SIP_SCHED_TASK_DELAY specifies that the next invocation of the task should start
 * at \ref interval milliseconds after the current invocation has finished.
 *
 */
struct ast_sip_sched_task *ast_sip_schedule_task(struct ast_taskprocessor *serializer,
   int interval, ast_sip_task sip_task, const char *name, void *task_data,
   enum ast_sip_scheduler_task_flags flags);

/*!
 * \brief Cancels the next invocation of a task
 * \since 13.9.0
 *
 * \param schtd The task structure pointer
 * \retval 0 Success
 * \retval -1 Failure
 * \note Only cancels future invocations not the currently running invocation.
 */
int ast_sip_sched_task_cancel(struct ast_sip_sched_task *schtd);

/*!
 * \brief Cancels the next invocation of a task by name
 * \since 13.9.0
 *
 * \param name The task name
 * \retval 0 Success
 * \retval -1 Failure
 * \note Only cancels future invocations not the currently running invocation.
 */
int ast_sip_sched_task_cancel_by_name(const char *name);

/*!
 * \brief Gets the last start and end times of the task
 * \since 13.9.0
 *
 * \param schtd The task structure pointer
 * \param[out] when_queued Pointer to a timeval structure to contain the time when queued
 * \param[out] last_start Pointer to a timeval structure to contain the time when last started
 * \param[out] last_end Pointer to a timeval structure to contain the time when last ended
 * \retval 0 Success
 * \retval -1 Failure
 * \note Any of the pointers can be NULL if you don't need them.
 */
int ast_sip_sched_task_get_times(struct ast_sip_sched_task *schtd,
   struct timeval *when_queued, struct timeval *last_start, struct timeval *last_end);

/*!
 * \brief Gets the queued, last start, last_end, time left, interval, next run
 * \since 16.15.0
 * \since 18.1.0
 *
 * \param schtd The task structure pointer
 * \param[out] when_queued Pointer to a timeval structure to contain the time when queued
 * \param[out] last_start Pointer to a timeval structure to contain the time when last started
 * \param[out] last_end Pointer to a timeval structure to contain the time when last ended
 * \param[out] interval Pointer to an int to contain the interval in ms
 * \param[out] time_left Pointer to an int to contain the ms left to the next run
 * \param[out] last_end Pointer to a timeval structure to contain the next run time
 * \retval 0 Success
 * \retval -1 Failure
 * \note Any of the pointers can be NULL if you don't need them.
 */
int ast_sip_sched_task_get_times2(struct ast_sip_sched_task *schtd,
   struct timeval *when_queued, struct timeval *last_start, struct timeval *last_end,
   int *interval, int *time_left, struct timeval *next_start);

/*!
 * \brief Gets the last start and end times of the task by name
 * \since 13.9.0
 *
 * \param name The task name
 * \param[out] when_queued Pointer to a timeval structure to contain the time when queued
 * \param[out] last_start Pointer to a timeval structure to contain the time when last started
 * \param[out] last_end Pointer to a timeval structure to contain the time when last ended
 * \retval 0 Success
 * \retval -1 Failure
 * \note Any of the pointers can be NULL if you don't need them.
 */
int ast_sip_sched_task_get_times_by_name(const char *name,
   struct timeval *when_queued, struct timeval *last_start, struct timeval *last_end);

/*!
 * \brief Gets the queued, last start, last_end, time left, interval, next run by task name
 * \since 16.15.0
 * \since 18.1.0
 *
 * \param name The task name
 * \param[out] when_queued Pointer to a timeval structure to contain the time when queued
 * \param[out] last_start Pointer to a timeval structure to contain the time when last started
 * \param[out] last_end Pointer to a timeval structure to contain the time when last ended
 * \param[out] interval Pointer to an int to contain the interval in ms
 * \param[out] time_left Pointer to an int to contain the ms left to the next run
 * \param[out] last_end Pointer to a timeval structure to contain the next run time
 * \retval 0 Success
 * \retval -1 Failure
 * \note Any of the pointers can be NULL if you don't need them.
 */
int ast_sip_sched_task_get_times_by_name2(const char *name,
   struct timeval *when_queued, struct timeval *last_start, struct timeval *last_end,
   int *interval, int *time_left, struct timeval *next_start);

/*!
 * \brief Gets the number of milliseconds until the next invocation
 * \since 13.9.0
 *
 * \param schtd The task structure pointer
 * \return The number of milliseconds until the next invocation or -1 if the task isn't scheduled
 */
int ast_sip_sched_task_get_next_run(struct ast_sip_sched_task *schtd);

/*!
 * \brief Gets the number of milliseconds until the next invocation
 * \since 13.9.0
 *
 * \param name The task name
 * \return The number of milliseconds until the next invocation or -1 if the task isn't scheduled
 */
int ast_sip_sched_task_get_next_run_by_name(const char *name);

/*!
 * \brief Checks if the task is currently running
 * \since 13.9.0
 *
 * \param schtd The task structure pointer
 * \retval 0 not running
 * \retval 1 running
 */
int ast_sip_sched_is_task_running(struct ast_sip_sched_task *schtd);

/*!
 * \brief Checks if the task is currently running
 * \since 13.9.0
 *
 * \param name The task name
 * \retval 0 not running or not found
 * \retval 1 running
 */
int ast_sip_sched_is_task_running_by_name(const char *name);

/*!
 * \brief Gets the task name
 * \since 13.9.0
 *
 * \param schtd The task structure pointer
 * \retval 0 success
 * \retval 1 failure
 */
int ast_sip_sched_task_get_name(struct ast_sip_sched_task *schtd, char *name, size_t maxlen);

/*!
 *  @}
 */

/*!
 * \brief SIP body description
 *
 * This contains a type and subtype that will be added as
 * the "Content-Type" for the message as well as the body
 * text.
 */
struct ast_sip_body {
   /*! Type of the body, such as "application" */
   const char *type;
   /*! Subtype of the body, such as "sdp" */
   const char *subtype;
   /*! The text to go in the body */
   const char *body_text;
};

/*!
 * \brief General purpose method for creating a UAC dialog with an endpoint
 *
 * \param endpoint A pointer to the endpoint
 * \param aor_name Optional name of the AOR to target, may even be an explicit SIP URI
 * \param request_user Optional user to place into the target URI
 *
 * \retval non-NULL success
 * \retval NULL failure
 */
pjsip_dialog *ast_sip_create_dialog_uac(const struct ast_sip_endpoint *endpoint, const char *aor_name, const char *request_user);

/*!
 * \brief General purpose method for creating a UAS dialog with an endpoint
 *
 * \deprecated This function is unsafe (due to the returned object not being locked nor
 *             having its reference incremented) and should no longer be used. Instead
 *             use ast_sip_create_dialog_uas_locked so a properly locked and referenced
 *             object is returned.
 *
 * \param endpoint A pointer to the endpoint
 * \param rdata The request that is starting the dialog
 * \param[out] status On failure, the reason for failure in creating the dialog
 */
pjsip_dialog *ast_sip_create_dialog_uas(const struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata, pj_status_t *status);

/*!
 * \brief General purpose method for creating a UAS dialog with an endpoint
 *
 * This function creates and returns a locked, and referenced counted pjsip
 * dialog object. The caller is thus responsible for freeing the allocated
 * memory, decrementing the reference, and releasing the lock when done with
 * the returned object.
 *
 * \note The safest way to unlock the object, and decrement its reference is by
 *       calling pjsip_dlg_dec_lock. Alternatively, pjsip_dlg_dec_session can be
 *       used to decrement the reference only.
 *
 * The dialog is returned locked and with a reference in order to ensure that the
 * dialog object, and any of its associated objects (e.g. transaction) are not
 * untimely destroyed. For instance, that could happen when a transport error
 * occurs.
 *
 * As long as the caller maintains a reference to the dialog there should be no
 * worry that it might unknowningly be destroyed. However, once the caller unlocks
 * the dialog there is a danger that some of the dialog's internal objects could
 * be lost and/or compromised. For example, when the aforementioned transport error
 * occurs the dialog's associated transaction gets destroyed (see pjsip_dlg_on_tsx_state
 * in sip_dialog.c, and mod_inv_on_tsx_state in sip_inv.c).
 *
 * In this case and before using the dialog again the caller should re-lock the
 * dialog, check to make sure the dialog is still established, and the transaction
 * still exists and has not been destroyed.
 *
 * \param endpoint A pointer to the endpoint
 * \param rdata The request that is starting the dialog
 * \param[out] status On failure, the reason for failure in creating the dialog
 *
 * \retval A locked, and reference counted pjsip_dialog object.
 * \retval NULL on failure
 */
pjsip_dialog *ast_sip_create_dialog_uas_locked(const struct ast_sip_endpoint *endpoint,
   pjsip_rx_data *rdata, pj_status_t *status);

/*!
 * \brief General purpose method for creating an rdata structure using specific information
 * \since 13.15.0
 *
 * \param rdata[out] The rdata structure that will be populated
 * \param packet A SIP message
 * \param src_name The source IP address of the message
 * \param src_port The source port of the message
 * \param transport_type The type of transport the message was received on
 * \param local_name The local IP address the message was received on
 * \param local_port The local port the message was received on
 * \param contact_uri The contact URI of the message
 *
 * \retval 0 success
 * \retval -1 failure
 */
int ast_sip_create_rdata_with_contact(pjsip_rx_data *rdata, char *packet,
   const char *src_name, int src_port, char *transport_type, const char *local_name,
   int local_port, const char *contact_uri);

/*!
 * \brief General purpose method for creating an rdata structure using specific information
 *
 * \param rdata[out] The rdata structure that will be populated
 * \param packet A SIP message
 * \param src_name The source IP address of the message
 * \param src_port The source port of the message
 * \param transport_type The type of transport the message was received on
 * \param local_name The local IP address the message was received on
 * \param local_port The local port the message was received on
 *
 * \retval 0 success
 * \retval -1 failure
 */
int ast_sip_create_rdata(pjsip_rx_data *rdata, char *packet, const char *src_name,
   int src_port, char *transport_type, const char *local_name, int local_port);

/*!
 * \brief General purpose method for creating a SIP request
 *
 * Its typical use would be to create one-off requests such as an out of dialog
 * SIP MESSAGE.
 *
 * The request can either be in- or out-of-dialog. If in-dialog, the
 * dlg parameter MUST be present. If out-of-dialog the endpoint parameter
 * MUST be present. If both are present, then we will assume that the message
 * is to be sent in-dialog.
 *
 * The uri parameter can be specified if the request should be sent to an explicit
 * URI rather than one configured on the endpoint.
 *
 * \param method The method of the SIP request to send
 * \param dlg Optional. If specified, the dialog on which to request the message.
 * \param endpoint Optional. If specified, the request will be created out-of-dialog to the endpoint.
 * \param uri Optional. If specified, the request will be sent to this URI rather
 * than one configured for the endpoint.
 * \param contact The contact with which this request is associated for out-of-dialog requests.
 * \param[out] tdata The newly-created request
 *
 * The provided contact is attached to tdata with its reference bumped, but will
 * not survive for the entire lifetime of tdata since the contact is cleaned up
 * when all supplements have completed execution.
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_create_request(const char *method, struct pjsip_dialog *dlg,
      struct ast_sip_endpoint *endpoint, const char *uri,
      struct ast_sip_contact *contact, pjsip_tx_data **tdata);

/*!
 * \brief General purpose method for sending a SIP request
 *
 * This is a companion function for \ref ast_sip_create_request. The request
 * created there can be passed to this function, though any request may be
 * passed in.
 *
 * This will automatically set up handling outbound authentication challenges if
 * they arrive.
 *
 * \param tdata The request to send
 * \param dlg Optional. The dialog in which the request is sent.  Otherwise it is out-of-dialog.
 * \param endpoint Optional. If specified, the out-of-dialog request is sent to the endpoint.
 * \param token Data to be passed to the callback upon receipt of out-of-dialog response.
 * \param callback Callback to be called upon receipt of out-of-dialog response.
 *
 * \retval 0 Success
 * \retval -1 Failure (out-of-dialog callback will not be called.)
 */
int ast_sip_send_request(pjsip_tx_data *tdata, struct pjsip_dialog *dlg,
   struct ast_sip_endpoint *endpoint, void *token,
   void (*callback)(void *token, pjsip_event *e));

/*!
 * \brief General purpose method for sending an Out-Of-Dialog SIP request
 *
 * This is a companion function for \ref ast_sip_create_request. The request
 * created there can be passed to this function, though any request may be
 * passed in.
 *
 * This will automatically set up handling outbound authentication challenges if
 * they arrive.
 *
 * \param tdata The request to send
 * \param endpoint Optional. If specified, the out-of-dialog request is sent to the endpoint.
 * \param timeout.  If non-zero, after the timeout the transaction will be terminated
 * and the callback will be called with the PJSIP_EVENT_TIMER type.
 * \param token Data to be passed to the callback upon receipt of out-of-dialog response.
 * \param callback Callback to be called upon receipt of out-of-dialog response.
 *
 * \retval 0 Success
 * \retval -1 Failure (out-of-dialog callback will not be called.)
 *
 * \note Timeout processing:
 * There are 2 timers associated with this request, PJSIP timer_b which is
 * set globally in the "system" section of pjsip.conf, and the timeout specified
 * on this call.  The timer that expires first (before normal completion) will
 * cause the callback to be run with e->body.tsx_state.type = PJSIP_EVENT_TIMER.
 * The timer that expires second is simply ignored and the callback is not run again.
 */
int ast_sip_send_out_of_dialog_request(pjsip_tx_data *tdata,
   struct ast_sip_endpoint *endpoint, int timeout, void *token,
   void (*callback)(void *token, pjsip_event *e));

/*!
 * \brief General purpose method for creating a SIP response
 *
 * Its typical use would be to create responses for out of dialog
 * requests.
 *
 * \param rdata The rdata from the incoming request.
 * \param st_code The response code to transmit.
 * \param contact The contact with which this request is associated.
 * \param[out] tdata The newly-created response
 *
 * The provided contact is attached to tdata with its reference bumped, but will
 * not survive for the entire lifetime of tdata since the contact is cleaned up
 * when all supplements have completed execution.
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_create_response(const pjsip_rx_data *rdata, int st_code,
   struct ast_sip_contact *contact, pjsip_tx_data **p_tdata);

/*!
 * \brief Send a response to an out of dialog request
 *
 * Use this function sparingly, since this does not create a transaction
 * within PJSIP. This means that if the request is retransmitted, it is
 * your responsibility to detect this and not process the same request
 * twice, and to send the same response for each retransmission.
 *
 * \param res_addr The response address for this response
 * \param tdata The response to send
 * \param endpoint The ast_sip_endpoint associated with this response
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_send_response(pjsip_response_addr *res_addr, pjsip_tx_data *tdata, struct ast_sip_endpoint *sip_endpoint);

/*!
 * \brief Send a stateful response to an out of dialog request
 *
 * This creates a transaction within PJSIP, meaning that if the request
 * that we are responding to is retransmitted, we will not attempt to
 * re-handle the request.
 *
 * \param rdata The request that is being responded to
 * \param tdata The response to send
 * \param endpoint The ast_sip_endpoint associated with this response
 *
 * \since 13.4.0
 *
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_send_stateful_response(pjsip_rx_data *rdata, pjsip_tx_data *tdata, struct ast_sip_endpoint *sip_endpoint);

/*!
 * \brief Determine if an incoming request requires authentication
 *
 * This calls into the registered authenticator's requires_authentication callback
 * in order to determine if the request requires authentication.
 *
 * If there is no registered authenticator, then authentication will be assumed
 * not to be required.
 *
 * \param endpoint The endpoint from which the request originates
 * \param rdata The incoming SIP request
 * \retval non-zero The request requires authentication
 * \retval 0 The request does not require authentication
 */
int ast_sip_requires_authentication(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);

/*!
 * \brief Method to determine authentication status of an incoming request
 *
 * This will call into a registered authenticator. The registered authenticator will
 * do what is necessary to determine whether the incoming request passes authentication.
 * A tentative response is passed into this function so that if, say, a digest authentication
 * challenge should be sent in the ensuing response, it can be added to the response.
 *
 * \param endpoint The endpoint from the request was sent
 * \param rdata The request to potentially authenticate
 * \param tdata Tentative response to the request
 * \return The result of checking authentication.
 */
enum ast_sip_check_auth_result ast_sip_check_authentication(struct ast_sip_endpoint *endpoint,
      pjsip_rx_data *rdata, pjsip_tx_data *tdata);

/*!
 * \brief Create a response to an authentication challenge
 *
 * This will call into an outbound authenticator's create_request_with_auth callback
 * to create a new request with authentication credentials. See the create_request_with_auth
 * callback in the \ref ast_sip_outbound_authenticator structure for details about
 * the parameters and return values.
 */
int ast_sip_create_request_with_auth(const struct ast_sip_auth_vector *auths, pjsip_rx_data *challenge,
      pjsip_tx_data *tdata, pjsip_tx_data **new_request);

/*!
 * \brief Determine the endpoint that has sent a SIP message
 *
 * This will call into each of the registered endpoint identifiers'
 * identify_endpoint() callbacks until one returns a non-NULL endpoint.
 * This will return an ao2 object. Its reference count will need to be
 * decremented when completed using the endpoint.
 *
 * \param rdata The inbound SIP message to use when identifying the endpoint.
 * \retval NULL No matching endpoint
 * \retval non-NULL The matching endpoint
 */
struct ast_sip_endpoint *ast_sip_identify_endpoint(pjsip_rx_data *rdata);

/*!
 * \brief Get a specific header value from rdata
 *
 * \note The returned value does not need to be freed since it's from the rdata pool
 *
 * \param rdata The rdata
 * \param str The header to find
 *
 * \retval NULL on failure
 * \retval The header value on success
 */
char *ast_sip_rdata_get_header_value(pjsip_rx_data *rdata, const pj_str_t str);

/*!
 * \brief Set the outbound proxy for an outbound SIP message
 *
 * \param tdata The message to set the outbound proxy on
 * \param proxy SIP uri of the proxy
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_set_outbound_proxy(pjsip_tx_data *tdata, const char *proxy);

/*!
 * \brief Add a header to an outbound SIP message
 *
 * \param tdata The message to add the header to
 * \param name The header name
 * \param value The header value
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_add_header(pjsip_tx_data *tdata, const char *name, const char *value);

/*!
 * \brief Add a body to an outbound SIP message
 *
 * If this is called multiple times, the latest body will replace the current
 * body.
 *
 * \param tdata The message to add the body to
 * \param body The message body to add
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_add_body(pjsip_tx_data *tdata, const struct ast_sip_body *body);

/*!
 * \brief Add a multipart body to an outbound SIP message
 *
 * This will treat each part of the input vector as part of a multipart body and
 * add each part to the SIP message.
 *
 * \param tdata The message to add the body to
 * \param bodies The parts of the body to add
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_add_body_multipart(pjsip_tx_data *tdata, const struct ast_sip_body *bodies[], int num_bodies);

/*!
 * \brief Append body data to a SIP message
 *
 * This acts mostly the same as ast_sip_add_body, except that rather than replacing
 * a body if it currently exists, it appends data to an existing body.
 *
 * \param tdata The message to append the body to
 * \param body The string to append to the end of the current body
 * \retval 0 Success
 * \retval -1 Failure
 */
int ast_sip_append_body(pjsip_tx_data *tdata, const char *body_text);

/*!
 * \brief Copy a pj_str_t into a standard character buffer.
 *
 * pj_str_t is not NULL-terminated. Any place that expects a NULL-
 * terminated string needs to have the pj_str_t copied into a separate
 * buffer.
 *
 * This method copies the pj_str_t contents into the destination buffer
 * and NULL-terminates the buffer.
 *
 * \param dest The destination buffer
 * \param src The pj_str_t to copy
 * \param size The size of the destination buffer.
 */
void ast_copy_pj_str(char *dest, const pj_str_t *src, size_t size);

/*!
 * \brief Create and copy a pj_str_t into a standard character buffer.
 *
 * pj_str_t is not NULL-terminated. Any place that expects a NULL-
 * terminated string needs to have the pj_str_t copied into a separate
 * buffer.
 *
 * Copies the pj_str_t contents into a newly allocated buffer pointed to
 * by dest. NULL-terminates the buffer.
 *
 * \note Caller is responsible for freeing the allocated memory.
 *
 * \param dest [out] The destination buffer
 * \param src The pj_str_t to copy
 * \retval Number of characters copied or negative value on error
 */
int ast_copy_pj_str2(char **dest, const pj_str_t *src);

/*!
 * \brief Get the looked-up endpoint on an out-of dialog request or response
 *
 * The function may ONLY be called on out-of-dialog requests or responses. For
 * in-dialog requests and responses, it is required that the user of the dialog
 * has the looked-up endpoint stored locally.
 *
 * This function should never return NULL if the message is out-of-dialog. It will
 * always return NULL if the message is in-dialog.
 *
 * This function will increase the reference count of the returned endpoint by one.
 * Release your reference using the ao2_ref function when finished.
 *
 * \param rdata Out-of-dialog request or response
 * \return The looked up endpoint
 */
struct ast_sip_endpoint *ast_pjsip_rdata_get_endpoint(pjsip_rx_data *rdata);

/*!
 * \brief Add 'user=phone' parameter to URI if enabled and user is a phone number.
 *
 * \param endpoint The endpoint to use for configuration
 * \param pool The memory pool to allocate the parameter from
 * \param uri The URI to check for user and to add parameter to
 */
void ast_sip_add_usereqphone(const struct ast_sip_endpoint *endpoint, pj_pool_t *pool, pjsip_uri *uri);

/*!
 * \brief Retrieve any endpoints available to sorcery.
 *
 * \retval Endpoints available to sorcery, NULL if no endpoints found.
 */
struct ao2_container *ast_sip_get_endpoints(void);

/*!
 * \brief Retrieve the default outbound endpoint.
 *
 * \retval The default outbound endpoint, NULL if not found.
 */
struct ast_sip_endpoint *ast_sip_default_outbound_endpoint(void);

/*!
 * \brief Retrieve relevant SIP auth structures from sorcery
 *
 * \param auths Vector of sorcery IDs of auth credentials to retrieve
 * \param[out] out The retrieved auths are stored here
 */
int ast_sip_retrieve_auths(const struct ast_sip_auth_vector *auths, struct ast_sip_auth **out);

/*!
 * \brief Clean up retrieved auth structures from memory
 *
 * Call this function once you have completed operating on auths
 * retrieved from \ref ast_sip_retrieve_auths
 *
 * \param auths An array of auth object pointers to clean up
 * \param num_auths The number of auths in the array
 */
void ast_sip_cleanup_auths(struct ast_sip_auth *auths[], size_t num_auths);

/*!
 * \brief Retrieve relevant SIP auth structures from sorcery as a vector
 *
 * \param auth_ids Vector of sorcery IDs of auth credentials to retrieve
 * \param[out] auth_objects A pointer ast_sip_auth_objects_vector to hold the objects
 *
 * \retval 0 Success
 * \retval -1 Number of auth objects found is less than the number of names supplied.
 *
 * \WARNING The number of auth objects retrieved may be less than the
 * number of auth ids supplied if auth objects couldn't be found for
 * some of them.
 *
 * \NOTE Since the ref count on all auith objects returned has been
 * bumped, you must call ast_sip_cleanup_auth_objects_vector() to decrement
 * the ref count on all of the auth objects in the vector,
 * then call AST_VECTOR_FREE() on the vector itself.
 *
 */
AST_VECTOR(ast_sip_auth_objects_vector, struct ast_sip_auth *);
int ast_sip_retrieve_auths_vector(const struct ast_sip_auth_vector *auth_ids,
   struct ast_sip_auth_objects_vector *auth_objects);

/*!
 * \brief Clean up retrieved auth objects in vector
 *
 * Call this function once you have completed operating on auths
 * retrieved from \ref ast_sip_retrieve_auths_vector.  All
 * auth objects will have their reference counts decremented and
 * the vector size will be reset to 0.  You must still call
 * AST_VECTOR_FREE() on the vector itself.
 *
 * \param auth_objects A vector of auth structures to clean up
 */
#define ast_sip_cleanup_auth_objects_vector(auth_objects) AST_VECTOR_RESET(auth_objects, ao2_cleanup)

/*!
 * \brief Checks if the given content type matches type/subtype.
 *
 * Compares the pjsip_media_type with the passed type and subtype and
 * returns the result of that comparison.  The media type parameters are
 * ignored.
 *
 * \param content_type The pjsip_media_type structure to compare
 * \param type The media type to compare
 * \param subtype The media subtype to compare
 * \retval 0 No match
 * \retval -1 Match
 */
int ast_sip_is_content_type(pjsip_media_type *content_type, char *type, char *subtype);

/*!
 * \brief Send a security event notification for when an invalid endpoint is requested
 *
 * \param name Name of the endpoint requested
 * \param rdata Received message
 */
void ast_sip_report_invalid_endpoint(const char *name, pjsip_rx_data *rdata);

/*!
 * \brief Send a security event notification for when an ACL check fails
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 * \param name Name of the ACL
 */
void ast_sip_report_failed_acl(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata, const char *name);

/*!
 * \brief Send a security event notification for when a challenge response has failed
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 */
void ast_sip_report_auth_failed_challenge_response(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);

/*!
 * \brief Send a security event notification for when authentication succeeds
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 */
void ast_sip_report_auth_success(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);

/*!
 * \brief Send a security event notification for when an authentication challenge is sent
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 * \param tdata Sent message
 */
void ast_sip_report_auth_challenge_sent(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata, pjsip_tx_data *tdata);

/*!
 * \brief Send a security event notification for when a request is not supported
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 * \param req_type the type of request
 */
void ast_sip_report_req_no_support(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata,
               const char* req_type);

/*!
 * \brief Send a security event notification for when a memory limit is hit.
 *
 * \param endpoint Pointer to the endpoint in use
 * \param rdata Received message
 */
void ast_sip_report_mem_limit(struct ast_sip_endpoint *endpoint, pjsip_rx_data *rdata);

int ast_sip_add_global_request_header(const char *name, const char *value, int replace);
int ast_sip_add_global_response_header(const char *name, const char *value, int replace);

/*!
 * \brief Retrieves the value associated with the given key.
 *
 * \param ht the hash table/dictionary to search
 * \param key the key to find
 *
 * \retval the value associated with the key, NULL otherwise.
 */
void *ast_sip_dict_get(void *ht, const char *key);

/*!
 * \brief Using the dictionary stored in mod_data array at a given id,
 *        retrieve the value associated with the given key.
 *
 * \param mod_data a module data array
 * \param id the mod_data array index
 * \param key the key to find
 *
 * \retval the value associated with the key, NULL otherwise.
 */
#define ast_sip_mod_data_get(mod_data, id, key)    \
   ast_sip_dict_get(mod_data[id], key)

/*!
 * \brief Set the value for the given key.
 *
 * Note - if the hash table does not exist one is created first, the key/value
 * pair is set, and the hash table returned.
 *
 * \param pool the pool to allocate memory in
 * \param ht the hash table/dictionary in which to store the key/value pair
 * \param key the key to associate a value with
 * \param val the value to associate with a key
 *
 * \retval the given, or newly created, hash table.
 */
void *ast_sip_dict_set(pj_pool_t* pool, void *ht,
             const char *key, void *val);

/*!
 * \brief Utilizing a mod_data array for a given id, set the value
 *        associated with the given key.
 *
 * For a given structure's mod_data array set the element indexed by id to
 * be a dictionary containing the key/val pair.
 *
 * \param pool a memory allocation pool
 * \param mod_data a module data array
 * \param id the mod_data array index
 * \param key the key to find
 * \param val the value to associate with a key
 */
#define ast_sip_mod_data_set(pool, mod_data, id, key, val)     \
   mod_data[id] = ast_sip_dict_set(pool, mod_data[id], key, val)

/*!
 * \brief For every contact on an AOR call the given 'on_contact' handler.
 *
 * \param aor the aor containing a list of contacts to iterate
 * \param on_contact callback on each contact on an AOR.  The object
 * received by the callback will be a ast_sip_contact_wrapper structure.
 * \param arg user data passed to handler
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_for_each_contact(const struct ast_sip_aor *aor,
      ao2_callback_fn on_contact, void *arg);

/*!
 * \brief Handler used to convert a contact to a string.
 *
 * \param object the ast_sip_aor_contact_pair containing a list of contacts to iterate and the contact
 * \param arg user data passed to handler
 * \param flags
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_contact_to_str(void *object, void *arg, int flags);

/*!
 * \brief For every aor in the comma separated aors string call the
 *        given 'on_aor' handler.
 *
 * \param aors a comma separated list of aors
 * \param on_aor callback for each aor
 * \param arg user data passed to handler
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_for_each_aor(const char *aors, ao2_callback_fn on_aor, void *arg);

/*!
 * \brief For every auth in the array call the given 'on_auth' handler.
 *
 * \param array an array of auths
 * \param on_auth callback for each auth
 * \param arg user data passed to handler
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_for_each_auth(const struct ast_sip_auth_vector *array,
           ao2_callback_fn on_auth, void *arg);

/*!
 * \brief Converts the given auth type to a string
 *
 * \param type the auth type to convert
 * \retval a string representative of the auth type
 */
const char *ast_sip_auth_type_to_str(enum ast_sip_auth_type type);

/*!
 * \brief Converts an auths array to a string of comma separated values
 *
 * \param auths an auth array
 * \param buf the string buffer to write the object data
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_auths_to_str(const struct ast_sip_auth_vector *auths, char **buf);

/*!
 * \brief AMI variable container
 */
struct ast_sip_ami {
   /*! Manager session */
   struct mansession *s;
   /*! Manager message */
   const struct message *m;
   /*! Manager Action ID */
   const char *action_id;
   /*! user specified argument data */
   void *arg;
   /*! count of objects */
   int count;
};

/*!
 * \brief Creates a string to store AMI event data in.
 *
 * \param event the event to set
 * \param ami AMI session and message container
 * \retval an initialized ast_str or NULL on error.
 */
struct ast_str *ast_sip_create_ami_event(const char *event,
                struct ast_sip_ami *ami);

/*!
 * \brief An entity responsible formatting endpoint information.
 */
struct ast_sip_endpoint_formatter {
   /*!
    * \brief Callback used to format endpoint information over AMI.
    */
   int (*format_ami)(const struct ast_sip_endpoint *endpoint,
           struct ast_sip_ami *ami);
   AST_RWLIST_ENTRY(ast_sip_endpoint_formatter) next;
};

/*!
 * \brief Register an endpoint formatter.
 *
 * \param obj the formatter to register
 */
void ast_sip_register_endpoint_formatter(struct ast_sip_endpoint_formatter *obj);

/*!
 * \brief Unregister an endpoint formatter.
 *
 * \param obj the formatter to unregister
 */
void ast_sip_unregister_endpoint_formatter(struct ast_sip_endpoint_formatter *obj);

/*!
 * \brief Converts a sorcery object to a string of object properties.
 *
 * \param obj the sorcery object to convert
 * \param str the string buffer to write the object data
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_sorcery_object_to_ami(const void *obj, struct ast_str **buf);

/*!
 * \brief Formats the endpoint and sends over AMI.
 *
 * \param endpoint the endpoint to format and send
 * \param endpoint ami AMI variable container
 * \param count the number of formatters operated on
 * \retval 0 Success, otherwise non-zero on error
 */
int ast_sip_format_endpoint_ami(struct ast_sip_endpoint *endpoint,
            struct ast_sip_ami *ami, int *count);

/*!
 * \brief Formats the contact and sends over AMI.
 *
 * \param obj a pointer an ast_sip_contact_wrapper structure
 * \param arg a pointer to an ast_sip_ami structure
 * \param flags ignored
 * \retval 0 Success, otherwise non-zero on error
 */
int ast_sip_format_contact_ami(void *obj, void *arg, int flags);

/*!
 * \brief Format auth details for AMI.
 *
 * \param auths an auth array
 * \param ami ami variable container
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_format_auths_ami(const struct ast_sip_auth_vector *auths,
              struct ast_sip_ami *ami);

/*!
 * \brief Retrieve the endpoint snapshot for an endpoint
 *
 * \param endpoint The endpoint whose snapshot is to be retreieved.
 * \retval The endpoint snapshot
 */
struct ast_endpoint_snapshot *ast_sip_get_endpoint_snapshot(
   const struct ast_sip_endpoint *endpoint);

/*!
 * \brief Retrieve the device state for an endpoint.
 *
 * \param endpoint The endpoint whose state is to be retrieved.
 * \retval The device state.
 */
const char *ast_sip_get_device_state(const struct ast_sip_endpoint *endpoint);

/*!
 * \brief For every channel snapshot on an endpoint snapshot call the given
 *        'on_channel_snapshot' handler.
 *
 * \param endpoint_snapshot snapshot of an endpoint
 * \param on_channel_snapshot callback for each channel snapshot
 * \param arg user data passed to handler
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_for_each_channel_snapshot(const struct ast_endpoint_snapshot *endpoint_snapshot,
      ao2_callback_fn on_channel_snapshot,
                  void *arg);

/*!
 * \brief For every channel snapshot on an endpoint all the given
 *        'on_channel_snapshot' handler.
 *
 * \param endpoint endpoint
 * \param on_channel_snapshot callback for each channel snapshot
 * \param arg user data passed to handler
 * \retval 0 Success, non-zero on failure
 */
int ast_sip_for_each_channel(const struct ast_sip_endpoint *endpoint,
      ao2_callback_fn on_channel_snapshot,
                  void *arg);

enum ast_sip_supplement_priority {
   /*! Top priority. Supplements with this priority are those that need to run before any others */
   AST_SIP_SUPPLEMENT_PRIORITY_FIRST = 0,
   /*! Channel creation priority.
    * chan_pjsip creates a channel at this priority. If your supplement depends on being run before
    * or after channel creation, then set your priority to be lower or higher than this value.
    */
   AST_SIP_SUPPLEMENT_PRIORITY_CHANNEL = 1000000,
   /*! Lowest priority. Supplements with this priority should be run after all other supplements */
   AST_SIP_SUPPLEMENT_PRIORITY_LAST = INT_MAX,
};

/*!
 * \brief A supplement to SIP message processing
 *
 * These can be registered by any module in order to add
 * processing to incoming and outgoing SIP out of dialog
 * requests and responses
 */
struct ast_sip_supplement {
   /*! Method on which to call the callbacks. If NULL, call on all methods */
   const char *method;
   /*! Priority for this supplement. Lower numbers are visited before higher numbers */
   enum ast_sip_supplement_priority priority;
   /*!
    * \brief Called on incoming SIP request
    * This method can indicate a failure in processing in its return. If there
    * is a failure, it is required that this method sends a response to the request.
    * This method is always called from a SIP servant thread.
    *
    * \note
    * The following PJSIP methods will not work properly:
    * pjsip_rdata_get_dlg()
    * pjsip_rdata_get_tsx()
    * The reason is that the rdata passed into this function is a cloned rdata structure,
    * and its module data is not copied during the cloning operation.
    * If you need to get the dialog, you can get it via session->inv_session->dlg.
    *
    * \note
    * There is no guarantee that a channel will be present on the session when this is called.
    */
   int (*incoming_request)(struct ast_sip_endpoint *endpoint, struct pjsip_rx_data *rdata);
   /*!
    * \brief Called on an incoming SIP response
    * This method is always called from a SIP servant thread.
    *
    * \note
    * The following PJSIP methods will not work properly:
    * pjsip_rdata_get_dlg()
    * pjsip_rdata_get_tsx()
    * The reason is that the rdata passed into this function is a cloned rdata structure,
    * and its module data is not copied during the cloning operation.
    * If you need to get the dialog, you can get it via session->inv_session->dlg.
    *
    * \note
    * There is no guarantee that a channel will be present on the session when this is called.
    */
   void (*incoming_response)(struct ast_sip_endpoint *endpoint, struct pjsip_rx_data *rdata);
   /*!
    * \brief Called on an outgoing SIP request
    * This method is always called from a SIP servant thread.
    */
   void (*outgoing_request)(struct ast_sip_endpoint *endpoint, struct ast_sip_contact *contact, struct pjsip_tx_data *tdata);
   /*!
    * \brief Called on an outgoing SIP response
    * This method is always called from a SIP servant thread.
    */
   void (*outgoing_response)(struct ast_sip_endpoint *endpoint, struct ast_sip_contact *contact, struct pjsip_tx_data *tdata);
   /*! Next item in the list */
   AST_LIST_ENTRY(ast_sip_supplement) next;
};

/*!
 * \brief Register a supplement to SIP out of dialog processing
 *
 * This allows for someone to insert themselves in the processing of out
 * of dialog SIP requests and responses. This, for example could allow for
 * a module to set channel data based on headers in an incoming message.
 * Similarly, a module could reject an incoming request if desired.
 *
 * \param supplement The supplement to register
 * \retval 0 Success
 * \retval -1 Failure
 */
void ast_sip_register_supplement(struct ast_sip_supplement *supplement);

/*!
 * \brief Unregister a an supplement to SIP out of dialog processing
 *
 * \param supplement The supplement to unregister
 */
void ast_sip_unregister_supplement(struct ast_sip_supplement *supplement);

/*!
 * \brief Retrieve the global MWI taskprocessor high water alert trigger level.
 *
 * \since 13.12.0
 *
 * \retval the system MWI taskprocessor high water alert trigger level
 */
unsigned int ast_sip_get_mwi_tps_queue_high(void);

/*!
 * \brief Retrieve the global MWI taskprocessor low water clear alert level.
 *
 * \since 13.12.0
 *
 * \retval the system MWI taskprocessor low water clear alert level
 */
int ast_sip_get_mwi_tps_queue_low(void);

/*!
 * \brief Retrieve the global setting 'disable sending unsolicited mwi on startup'.
 * \since 13.12.0
 *
 * \retval non zero if disable.
 */
unsigned int ast_sip_get_mwi_disable_initial_unsolicited(void);

/*!
 * \brief Retrieve the global setting 'use_callerid_contact'.
 * \since 13.24.0
 *
 * \retval non zero if CALLERID(num) is to be used as the default username in the contact
 */
unsigned int ast_sip_get_use_callerid_contact(void);

/*!
 * \brief Retrieve the global setting 'norefersub'.
 *
 * \retval non zero if norefersub is to be sent in "Supported" Headers
 */
unsigned int ast_sip_get_norefersub(void);

/*!
 * \brief Retrieve the global setting 'ignore_uri_user_options'.
 * \since 13.12.0
 *
 * \retval non zero if ignore the user field options.
 */
unsigned int ast_sip_get_ignore_uri_user_options(void);

/*!
 * \brief Retrieve the global setting 'send_contact_status_on_update_registration'.
 * \since 16.2.0
 *
 * \retval non zero if need to send AMI ContactStatus event when a contact is updated.
 */
unsigned int ast_sip_get_send_contact_status_on_update_registration(void);


/*!
 * \brief Truncate the URI user field options string if enabled.
 * \since 13.12.0
 *
 * \param str URI user field string to truncate if enabled
 *
 * \details
 * We need to be able to handle URI's looking like
 * "sip:1235557890;[email protected];user=phone"
 *
 * Where the URI user field is:
 * "1235557890;phone-context=national"
 *
 * When truncated the string will become:
 * "1235557890"
 */
#define AST_SIP_USER_OPTIONS_TRUNCATE_CHECK(str)            \
   do {                                         \
      char *__semi = strchr((str), ';');                 \
      if (__semi && ast_sip_get_ignore_uri_user_options()) {   \
         *__semi = '\0';                              \
      }                                         \
   } while (0)

/*!
 * \brief Retrieve the system debug setting (yes|no|host).
 *
 * \note returned string needs to be de-allocated by caller.
 *
 * \retval the system debug setting.
 */
char *ast_sip_get_debug(void);

/*!
 * \brief Retrieve the global regcontext setting.
 *
 * \since 13.8.0
 *
 * \note returned string needs to be de-allocated by caller.
 *
 * \retval the global regcontext setting
 */
char *ast_sip_get_regcontext(void);

/*!
 * \brief Retrieve the global endpoint_identifier_order setting.
 *
 * Specifies the order by which endpoint identifiers should be regarded.
 *
 * \retval the global endpoint_identifier_order value
 */
char *ast_sip_get_endpoint_identifier_order(void);

/*!
 * \brief Retrieve the default voicemail extension.
 * \since 13.9.0
 *
 * \note returned string needs to be de-allocated by caller.
 *
 * \retval the default voicemail extension
 */
char *ast_sip_get_default_voicemail_extension(void);

/*!
 * \brief Retrieve the global default realm.
 *
 * This is the value placed in outbound challenges' realm if there
 * is no better option (such as an auth-configured realm).
 *
 * \param[out] realm The default realm
 * \param size The buffer size of realm
 * \return nothing
 */
void ast_sip_get_default_realm(char *realm, size_t size);

/*!
 * \brief Retrieve the global default from user.
 *
 * This is the value placed in outbound requests' From header if there
 * is no better option (such as an endpoint-configured from_user or
 * caller ID number).
 *
 * \param[out] from_user The default from user
 * \param size The buffer size of from_user
 * \return nothing
 */
void ast_sip_get_default_from_user(char *from_user, size_t size);

/*!
 * \brief Retrieve the system keep alive interval setting.
 *
 * \retval the keep alive interval.
 */
unsigned int ast_sip_get_keep_alive_interval(void);

/*!
 * \brief Retrieve the system contact expiration check interval setting.
 *
 * \retval the contact expiration check interval.
 */
unsigned int ast_sip_get_contact_expiration_check_interval(void);

/*!
 * \brief Retrieve the system setting 'disable multi domain'.
 * \since 13.9.0
 *
 * \retval non zero if disable multi domain.
 */
unsigned int ast_sip_get_disable_multi_domain(void);

/*!
 * \brief Retrieve the system max initial qualify time.
 *
 * \retval the maximum initial qualify time.
 */
unsigned int ast_sip_get_max_initial_qualify_time(void);

/*!
 * \brief translate ast_sip_contact_status_type to character string.
 *
 * \retval the character string equivalent.
 */

const char *ast_sip_get_contact_status_label(const enum ast_sip_contact_status_type status);
const char *ast_sip_get_contact_short_status_label(const enum ast_sip_contact_status_type status);

/*!
 * \brief Set a request to use the next value in the list of resolved addresses.
 *
 * \param tdata the tx data from the original request
 * \retval 0 No more addresses to try
 * \retval 1 The request was successfully re-intialized
 */
int ast_sip_failover_request(pjsip_tx_data *tdata);

/*!
 * \brief Retrieve the local host address in IP form
 *
 * \param af The address family to retrieve
 * \param addr A place to store the local host address
 *
 * \retval 0 success
 * \retval -1 failure
 *
 * \since 13.6.0
 */
int ast_sip_get_host_ip(int af, pj_sockaddr *addr);

/*!
 * \brief Retrieve the local host address in string form
 *
 * \param af The address family to retrieve
 *
 * \retval non-NULL success
 * \retval NULL failure
 *
 * \since 13.6.0
 *
 * \note An empty string may be returned if the address family is valid but no local address exists
 */
const char *ast_sip_get_host_ip_string(int af);

/*!
 * \brief Return the size of the SIP threadpool's task queue
 * \since 13.7.0
 */
long ast_sip_threadpool_queue_size(void);

/*!
 * \brief Retrieve the SIP threadpool object
 */
struct ast_threadpool *ast_sip_threadpool(void);

/*!
 * \brief Retrieve transport state
 * \since 13.7.1
 *
 * @param transport_id
 * @returns transport_state
 *
 * \note ao2_cleanup(...) or ao2_ref(...,  -1) must be called on the returned object
 */
struct ast_sip_transport_state *ast_sip_get_transport_state(const char *transport_id);

/*!
 * \brief Retrieves all transport states
 * \since 13.7.1
 *
 * @returns ao2_container
 *
 * \note ao2_cleanup(...) or ao2_ref(...,  -1) must be called on the returned object
 */
struct ao2_container *ast_sip_get_transport_states(void);

/*!
 * \brief Sets pjsip_tpselector from ast_sip_transport
 * \since 13.8.0
 *
 * \param transport The transport to be used
 * \param selector The selector to be populated
 * \retval 0 success
 * \retval -1 failure
 *
 * \note The transport selector must be unreffed using ast_sip_tpselector_unref
 */
int ast_sip_set_tpselector_from_transport(const struct ast_sip_transport *transport, pjsip_tpselector *selector);

/*!
 * \brief Sets pjsip_tpselector from ast_sip_transport
 * \since 13.8.0
 *
 * \param transport_name The name of the transport to be used
 * \param selector The selector to be populated
 * \retval 0 success
 * \retval -1 failure
 *
 * \note The transport selector must be unreffed using ast_sip_tpselector_unref
 */
int ast_sip_set_tpselector_from_transport_name(const char *transport_name, pjsip_tpselector *selector);

/*!
 * \brief Unreference a pjsip_tpselector
 * \since 17.0.0
 *
 * \param selector The selector to be unreffed
 */
void ast_sip_tpselector_unref(pjsip_tpselector *selector);

/*!
 * \brief Sets the PJSIP transport on a child transport
 * \since 17.0.0
 *
 * \param transport_name The name of the transport to be updated
 * \param transport The PJSIP transport
 * \retval 0 success
 * \retval -1 failure
 */
int ast_sip_transport_state_set_transport(const char *transport_name, pjsip_transport *transport);

/*!
 * \brief Sets the P-Preferred-Identity on a child transport
 * \since 17.0.0
 *
 * \param transport_name The name of the transport to be set on
 * \param identity The P-Preferred-Identity to use on requests on this transport
 * \retval 0 success
 * \retval -1 failure
 */
int ast_sip_transport_state_set_preferred_identity(const char *transport_name, const char *identity);

/*!
 * \brief Sets the service routes on a child transport
 * \since 17.0.0
 *
 * \param transport_name The name of the transport to be set on
 * \param service_routes A vector of service routes
 * \retval 0 success
 * \retval -1 failure
 *
 * \note This assumes ownership of the service routes in both success and failure scenarios
 */
int ast_sip_transport_state_set_service_routes(const char *transport_name, struct ast_sip_service_route_vector *service_routes);

/*!
 * \brief Apply the configuration for a transport to an outgoing message
 * \since 17.0.0
 *
 * \param transport_name The name of the transport to apply configuration from
 * \param tdata The SIP message
 */
void ast_sip_message_apply_transport(const char *transport_name, pjsip_tx_data *tdata);

/*!
 * \brief Allocate a vector of service routes
 * \since 17.0.0
 *
 * \retval non-NULL success
 * \retval NULL failure
 */
struct ast_sip_service_route_vector *ast_sip_service_route_vector_alloc(void);

/*!
 * \brief Destroy a vector of service routes
 * \since 17.0.0
 *
 * \param service_routes A vector of service routes
 */
void ast_sip_service_route_vector_destroy(struct ast_sip_service_route_vector *service_routes);

/*!
 * \brief Set name and number information on an identity header.
 *
 * \param pool Memory pool to use for string duplication
 * \param id_hdr A From, P-Asserted-Identity, or Remote-Party-ID header to modify
 * \param id The identity information to apply to the header
 */
void ast_sip_modify_id_header(pj_pool_t *pool, pjsip_fromto_hdr *id_hdr,
   const struct ast_party_id *id);

/*!
 * \brief Retrieve the unidentified request security event thresholds
 * \since 13.8.0
 *
 * \param count The maximum number of unidentified requests per source ip to accumulate before emitting a security event
 * \param period The period in seconds over which to accumulate unidentified requests
 * \param prune_interval The interval in seconds at which expired entries will be pruned
 */
void ast_sip_get_unidentified_request_thresholds(unsigned int *count, unsigned int *period,
   unsigned int *prune_interval);

/*!
 * \brief Get the transport name from an endpoint or request uri
 * \since 13.15.0
 *
 * \param endpoint
 * \param sip_uri
 * \param buf Buffer to receive transport name
 * \param buf_len Buffer length
 *
 * \retval 0 Success
 * \retval -1 Failure
 *
 * \note
 * If endpoint->transport is not NULL, it is returned in buf.
 * Otherwise if sip_uri has an 'x-ast-txp' parameter AND the sip_uri host is
 * an ip4 or ip6 address, its value is returned,
 */
int ast_sip_get_transport_name(const struct ast_sip_endpoint *endpoint,
   pjsip_sip_uri *sip_uri, char *buf, size_t buf_len);

/*!
 * \brief Sets pjsip_tpselector from an endpoint or uri
 * \since 13.15.0
 *
 * \param endpoint If endpoint->transport is set, it's used
 * \param sip_uri If sip_uri contains a x-ast-txp parameter, it's used
 * \param selector The selector to be populated
 *
 * \retval 0 success
 * \retval -1 failure
 */
int ast_sip_set_tpselector_from_ep_or_uri(const struct ast_sip_endpoint *endpoint,
   pjsip_sip_uri *sip_uri, pjsip_tpselector *selector);

/*!
 * \brief Set the transport on a dialog
 * \since 13.15.0
 *
 * \param endpoint
 * \param dlg
 * \param selector (optional)
 *
 * \note
 * This API calls ast_sip_get_transport_name(endpoint, dlg->target) and if the result is
 * non-NULL, calls pjsip_dlg_set_transport.  If 'selector' is non-NULL, it is updated with
 * the selector used.
 *
 * \note
 * It is the responsibility of the caller to unref the passed in selector if one is provided.
 */
int ast_sip_dlg_set_transport(const struct ast_sip_endpoint *endpoint, pjsip_dialog *dlg,
   pjsip_tpselector *selector);

/*!
 * \brief Convert the DTMF mode enum value into a string
 * \since 13.18.0
 *
 * \param dtmf the dtmf mode
 * \param buf Buffer to receive dtmf mode string
 * \param buf_len Buffer length
 *
 * \retval 0 Success
 * \retval -1 Failure
 *
 */
int ast_sip_dtmf_to_str(const enum ast_sip_dtmf_mode dtmf,
   char *buf, size_t buf_len);

/*!
 * \brief Convert the DTMF mode name into an enum
 * \since 13.18.0
 *
 * \param dtmf_mode dtmf mode as a string
 *
 * \retval  >= 0 The enum value
 * \retval -1 Failure
 *
 */
int ast_sip_str_to_dtmf(const char *dtmf_mode);

/*!
 * \brief Convert the call codec preference flags to a string
 * \since 18.0.0
 *
 * \param pref the call codec preference setting
 *
 * \returns a constant string with either the setting value or 'unknown'
 * \note Don't try to free the string!
 *
 */
const char *ast_sip_call_codec_pref_to_str(struct ast_flags pref);

/*!
 * \brief Convert a call codec preference string to preference flags
 * \since 18.0.0
 *
 * \param pref A pointer to an ast_flags structure to receive the preference flags
 * \param pref_str The call codec preference setting string
 * \param is_outgoing Is for outgoing calls?
 *
 * \retval 0 The string was parsed successfully
 * \retval -1 The string option was invalid
 */
int ast_sip_call_codec_str_to_pref(struct ast_flags *pref, const char *pref_str, int is_outgoing);

/*!
 * \brief Transport shutdown monitor callback.
 * \since 13.18.0
 *
 * \param data User data to know what to do when transport shuts down.
 *
 * \note The callback does not need to care that data is an ao2 object.
 *
 * \return Nothing
 */
typedef void (*ast_transport_monitor_shutdown_cb)(void *data);

/*!
 * \brief Transport shutdown monitor data matcher
 * \since 13.20.0
 *
 * \param a User data to compare.
 * \param b User data to compare.
 *
 * \retval 1 The data objects match
 * \retval 0 The data objects don't match
 */
typedef int (*ast_transport_monitor_data_matcher)(void *a, void *b);

enum ast_transport_monitor_reg {
   /*! \brief Successfully registered the transport monitor */
   AST_TRANSPORT_MONITOR_REG_SUCCESS,
   /*! \brief Replaced the already existing transport monitor with new one. */
   AST_TRANSPORT_MONITOR_REG_REPLACED,
   /*!
    * \brief Transport not found to monitor.
    * \note Transport is either already shutdown or is not reliable.
    */
   AST_TRANSPORT_MONITOR_REG_NOT_FOUND,
   /*! \brief Error while registering transport monitor. */
   AST_TRANSPORT_MONITOR_REG_FAILED,
};

/*!
 * \brief Register a reliable transport shutdown monitor callback.
 * \since 13.20.0
 *
 * \param transport Transport to monitor for shutdown.
 * \param cb Who to call when transport is shutdown.
 * \param ao2_data Data to pass with the callback.
 *
 * \note The data object passed will have its reference count automatically
 * incremented by this call and automatically decremented after the callback
 * runs or when the callback is unregistered.
 *
 * There is no checking for duplicate registrations.
 *
 * \return enum ast_transport_monitor_reg
 */
enum ast_transport_monitor_reg ast_sip_transport_monitor_register(pjsip_transport *transport,
   ast_transport_monitor_shutdown_cb cb, void *ao2_data);

/*!
 * \brief Register a reliable transport shutdown monitor callback replacing any duplicate.
 * \since 13.26.0
 * \since 16.3.0
 *
 * \param transport Transport to monitor for shutdown.
 * \param cb Who to call when transport is shutdown.
 * \param ao2_data Data to pass with the callback.
 * \param matches Matcher function that returns true if data matches a previously
 *                registered data object
 *
 * \note The data object passed will have its reference count automatically
 * incremented by this call and automatically decremented after the callback
 * runs or when the callback is unregistered.
 *
 * This function checks for duplicates, and overwrites/replaces the old monitor
 * with the given one.
 *
 * \return enum ast_transport_monitor_reg
 */
enum ast_transport_monitor_reg ast_sip_transport_monitor_register_replace(pjsip_transport *transport,
   ast_transport_monitor_shutdown_cb cb, void *ao2_data, ast_transport_monitor_data_matcher matches);

/*!
 * \brief Unregister a reliable transport shutdown monitor
 * \since 13.20.0
 *
 * \param transport Transport to monitor for shutdown.
 * \param cb The callback that was used for the original register.
 * \param data Data to pass to the matcher. May be NULL and does NOT need to be an ao2 object.
 *             If NULL, all monitors with the provided callbck are unregistered.
 * \param matches Matcher function that returns true if data matches the previously
 *                registered data object.  If NULL, a simple pointer comparison is done.
 *
 * \note The data object passed into the original register will have its reference count
 * automatically decremeneted.
 *
 * \return Nothing
 */
void ast_sip_transport_monitor_unregister(pjsip_transport *transport,
   ast_transport_monitor_shutdown_cb cb, void *data, ast_transport_monitor_data_matcher matches);

/*!
 * \brief Unregister a transport shutdown monitor from all reliable transports
 * \since 13.20.0
 *
 * \param cb The callback that was used for the original register.
 * \param data Data to pass to the matcher. May be NULL and does NOT need to be an ao2 object.
 *             If NULL, all monitors with the provided callbck are unregistered.
 * \param matches Matcher function that returns true if ao2_data matches the previously
 *                registered data object.  If NULL, a simple pointer comparison is done.
 *
 * \note The data object passed into the original register will have its reference count
 * automatically decremeneted.
 *
 * \return Nothing
 */
void ast_sip_transport_monitor_unregister_all(ast_transport_monitor_shutdown_cb cb,
   void *data, ast_transport_monitor_data_matcher matches);

/*! Transport state notification registration element.  */
struct ast_sip_tpmgr_state_callback {
   /*! PJPROJECT transport state notification callback */
   pjsip_tp_state_callback cb;
   AST_LIST_ENTRY(ast_sip_tpmgr_state_callback) node;
};

/*!
 * \brief Register a transport state notification callback element.
 * \since 13.18.0
 *
 * \param element What we are registering.
 *
 * \return Nothing
 */
void ast_sip_transport_state_register(struct ast_sip_tpmgr_state_callback *element);

/*!
 * \brief Unregister a transport state notification callback element.
 * \since 13.18.0
 *
 * \param element What we are unregistering.
 *
 * \return Nothing
 */
void ast_sip_transport_state_unregister(struct ast_sip_tpmgr_state_callback *element);

#endif /* _RES_PJSIP_H */