res_pjsip_outbound_registration.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Joshua Colp <jcolp@digium.com>
 *
 * 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.
 */
 
/*** MODULEINFO
    <depend>pjproject</depend>
    <depend>res_pjsip</depend>
    <use type="module">res_statsd</use>
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <pjsip.h>
#include <pjsip_ua.h>
 
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_cli.h"
#include "asterisk/module.h"
#include "asterisk/taskprocessor.h"
#include "asterisk/cli.h"
#include "asterisk/stasis_system.h"
#include "asterisk/threadstorage.h"
#include "asterisk/threadpool.h"
#include "asterisk/statsd.h"
#include "res_pjsip/include/res_pjsip_private.h"
#include "asterisk/vector.h"
#include "asterisk/pbx.h"
 
/*** DOCUMENTATION
    <configInfo name="res_pjsip_outbound_registration" language="en_US">
        <synopsis>SIP resource for outbound registrations</synopsis>
        <description><para>
            <emphasis>Outbound Registration</emphasis>
            </para>
            <para>This module allows <literal>res_pjsip</literal> to register to other SIP servers.</para>
        </description>
        <configFile name="pjsip.conf">
            <configObject name="registration">
                <synopsis>The configuration for outbound registration</synopsis>
                <description><para>
                    Registration is <emphasis>COMPLETELY</emphasis> separate from the rest of
                    <literal>pjsip.conf</literal>. A minimal configuration consists of
                    setting a <literal>server_uri</literal> and a <literal>client_uri</literal>.
                </para></description>
                <configOption name="auth_rejection_permanent" default="yes">
                    <synopsis>Determines whether failed authentication challenges are treated
                    as permanent failures.</synopsis>
                    <description><para>If this option is enabled and an authentication challenge fails,
                    registration will not be attempted again until the configuration is reloaded.</para></description>
                </configOption>
                <configOption name="client_uri">
                    <synopsis>Client SIP URI used when attemping outbound registration</synopsis>
                    <description><para>
                        This is the address-of-record for the outbound registration (i.e. the URI in
                        the To header of the REGISTER).</para>
                        <para>For registration with an ITSP, the client SIP URI may need to consist of
                        an account name or number and the provider's hostname for their registrar, e.g.
                        client_uri=1234567890@example.com. This may differ between providers.</para>
                        <para>For registration to generic registrars, the client SIP URI will depend
                        on networking specifics and configuration of the registrar.
                    </para></description>
                </configOption>
                <configOption name="contact_user" default="s">
                    <synopsis>Contact User to use in request. If this value is not set, this defaults to 's'</synopsis>
                </configOption>
                <configOption name="contact_header_params">
                    <synopsis>Header parameters to place in the Contact header</synopsis>
                </configOption>
                <configOption name="expiration" default="3600">
                    <synopsis>Expiration time for registrations in seconds</synopsis>
                </configOption>
                <configOption name="max_retries" default="10">
                    <synopsis>Maximum number of registration attempts.</synopsis>
                    <description><para>
                        This sets the maximum number of registration attempts that are made before
                        stopping any further attempts. If set to 0 then upon failure no further attempts
                        are made.
                    </para></description>
                </configOption>
                <configOption name="security_negotiation" default="no">
                    <synopsis>The kind of security agreement negotiation to use. Currently, only mediasec is supported.</synopsis>
                    <description>
                        <enumlist>
                            <enum name="no" />
                            <enum name="mediasec" />
                        </enumlist>
                    </description>
                </configOption>
                <configOption name="security_mechanisms">
                    <synopsis>List of security mechanisms supported.</synopsis>
                    <description><para>
                        This is a comma-delimited list of security mechanisms to use. Each security mechanism
                        must be in the form defined by RFC 3329 section 2.2.
                    </para></description>
                </configOption>
                <configOption name="outbound_auth" default="">
                    <synopsis>Authentication object(s) to be used for outbound registrations.</synopsis>
                    <description><para>
                        This is a comma-delimited list of <replaceable>auth</replaceable>
                        sections defined in <filename>pjsip.conf</filename> used to respond
                        to outbound authentication challenges.</para>
                        <note><para>
                        Using the same auth section for inbound and outbound
                        authentication is not recommended.  There is a difference in
                        meaning for an empty realm setting between inbound and outbound
                        authentication uses.  See the auth realm description for details.
                        </para></note>
                    </description>
                </configOption>
                <configOption name="outbound_proxy" default="">
                    <synopsis>Full SIP URI of the outbound proxy used to send registrations</synopsis>
                </configOption>
                <configOption name="max_random_initial_delay" default="10">
                    <synopsis>Maximum interval in seconds for which an initial registration may be randomly delayed</synopsis>
                    <description>
                        <para>By default, registrations are randomly delayed by a small amount to prevent
                        too many registrations from being made simultaneously.</para>
                        <para>Depending on your system usage, it may be desirable to set this to a smaller
                        or larger value to have fine grained control over the size of this random delay.</para>
                    </description>
                </configOption>
                <configOption name="retry_interval" default="60">
                    <synopsis>Interval in seconds between retries if outbound registration is unsuccessful</synopsis>
                </configOption>
                <configOption name="forbidden_retry_interval" default="0">
                    <synopsis>Interval used when receiving a 403 Forbidden response.</synopsis>
                    <description><para>
                        If a 403 Forbidden is received, chan_pjsip will wait
                        <replaceable>forbidden_retry_interval</replaceable> seconds before
                        attempting registration again. If 0 is specified, chan_pjsip will not
                        retry after receiving a 403 Forbidden response. Setting this to a non-zero
                        value goes against a "SHOULD NOT" in RFC3261, but can be used to work around
                        buggy registrars.
                    </para></description>
                </configOption>
                <configOption name="fatal_retry_interval" default="0">
                    <synopsis>Interval used when receiving a Fatal response.</synopsis>
                    <description><para>
                        If a fatal response is received, chan_pjsip will wait
                        <replaceable>fatal_retry_interval</replaceable> seconds before
                        attempting registration again. If 0 is specified, chan_pjsip will not
                        retry after receiving a fatal (non-temporary 4xx, 5xx, 6xx) response.
                        Setting this to a non-zero value may go against a "SHOULD NOT" in RFC3261,
                        but can be used to work around buggy registrars.</para>
                        <note><para>if also set the <replaceable>forbidden_retry_interval</replaceable>
                        takes precedence over this one when a 403 is received.
                        Also, if <replaceable>auth_rejection_permanent</replaceable> equals 'yes' then
                        a 401 and 407 become subject to this retry interval.</para></note>
                    </description>
                </configOption>
                <configOption name="server_uri">
                    <synopsis>SIP URI of the server to register against</synopsis>
                    <description><para>
                        This is the URI at which to find the registrar to send the outbound REGISTER. This URI
                        is used as the request URI of the outbound REGISTER request from Asterisk.</para>
                        <para>For registration with an ITSP, the setting may often be just the domain of
                        the registrar, e.g. sip:sip.example.com.
                    </para></description>
                </configOption>
                <configOption name="transport">
                    <synopsis>Transport used for outbound authentication</synopsis>
                    <description>
                        <note><para>A <replaceable>transport</replaceable> configured in
                        <literal>pjsip.conf</literal>. As with other <literal>res_pjsip</literal> modules, this will use the first available transport of the appropriate type if unconfigured.</para></note>
                    </description>
                </configOption>
                <configOption name="line">
                    <synopsis>Whether to add a 'line' parameter to the Contact for inbound call matching</synopsis>
                    <description><para>
                        When enabled this option will cause a 'line' parameter to be added to the Contact
                        header placed into the outgoing registration request. If the remote server sends a call
                        this line parameter will be used to establish a relationship to the outbound registration,
                        ultimately causing the configured endpoint to be used.
                    </para></description>
                </configOption>
                <configOption name="endpoint">
                    <synopsis>Endpoint to use for incoming related calls</synopsis>
                    <description><para>
                        When line support is enabled this configured endpoint name is used for incoming calls
                        that are related to the outbound registration.
                    </para></description>
                </configOption>
                <configOption name="type">
                    <synopsis>Must be of type 'registration'.</synopsis>
                </configOption>
                <configOption name="support_path">
                    <synopsis>Enables advertising SIP Path support for outbound REGISTER requests.</synopsis>
                    <description><para>
                        When this option is enabled, outbound REGISTER requests will advertise
                        support for Path headers so that intervening proxies can add to the Path
                        header as necessary.
                    </para></description>
                </configOption>
                <configOption name="support_outbound">
                    <synopsis>Enables advertising SIP Outbound support (RFC5626) for outbound REGISTER requests.</synopsis>
                </configOption>
                <configOption name="user_agent">
                    <synopsis>Overrides the User-Agent header that should be used for outbound REGISTER requests.</synopsis>
                </configOption>
            </configObject>
        </configFile>
    </configInfo>
    <manager name="PJSIPUnregister" language="en_US">
        <synopsis>
            Unregister an outbound registration.
        </synopsis>
        <syntax>
            <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
            <parameter name="Registration" required="true">
                <para>The outbound registration to unregister or '*all' to unregister them all.</para>
            </parameter>
        </syntax>
        <description>
            <para>
            Unregisters the specified (or all) outbound registration(s) and stops future registration attempts.
            Call PJSIPRegister to start registration and schedule re-registrations according to configuration.
            </para>
        </description>
    </manager>
    <manager name="PJSIPRegister" language="en_US">
        <synopsis>
            Register an outbound registration.
        </synopsis>
        <syntax>
            <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
            <parameter name="Registration" required="true">
                <para>The outbound registration to register or '*all' to register them all.</para>
            </parameter>
        </syntax>
        <description>
            <para>
            Unregisters the specified (or all) outbound registration(s) then starts registration and schedules re-registrations
            according to configuration.
            </para>
        </description>
    </manager>
    <manager name="PJSIPShowRegistrationsOutbound" language="en_US">
        <synopsis>
            Lists PJSIP outbound registrations.
        </synopsis>
        <syntax />
        <description>
            <para>
            In response <literal>OutboundRegistrationDetail</literal> events showing configuration and status
            information are raised for each outbound registration object. <literal>AuthDetail</literal>
            events are raised for each associated auth object as well.  Once all events are completed an
            <literal>OutboundRegistrationDetailComplete</literal> is issued.
                        </para>
        </description>
    </manager>
 ***/
 
/* forward declarations */
static int set_outbound_initial_authentication_credentials(pjsip_regc *regc,
        const struct ast_sip_auth_vector *auth_vector);
 
/*! \brief Some thread local storage used to determine if the running thread invoked the callback */
AST_THREADSTORAGE(register_callback_invoked);
 
/*! \brief Amount of buffer time (in seconds) before expiration that we re-register at */
#define REREGISTER_BUFFER_TIME 10
 
/*! \brief Size of the buffer for creating a unique string for the line */
#define LINE_PARAMETER_SIZE 8
 
/*! \brief Various states that an outbound registration may be in */
enum sip_outbound_registration_status {
    /*! \brief Currently unregistered */
    SIP_REGISTRATION_UNREGISTERED = 0,
    /*! \brief Registered, yay! */
    SIP_REGISTRATION_REGISTERED,
    /*! \brief Registration was rejected, but response was temporal */
    SIP_REGISTRATION_REJECTED_TEMPORARY,
    /*! \brief Registration was rejected, permanently */
    SIP_REGISTRATION_REJECTED_PERMANENT,
    /*! \brief Registration is stopping. */
    SIP_REGISTRATION_STOPPING,
    /*! \brief Registration has been stopped */
    SIP_REGISTRATION_STOPPED,
};
 
/*!
 * \internal
 * \brief Convert the internal registration state to an external status string.
 * \since 13.5.0
 *
 * \param state Current outbound registration state.
 *
 * \return External registration status string.
 */
static const char *sip_outbound_registration_status_str(enum sip_outbound_registration_status state)
{
    const char *str;
 
    str = "Unregistered";
    switch (state) {
    case SIP_REGISTRATION_STOPPING:
    case SIP_REGISTRATION_STOPPED:
    case SIP_REGISTRATION_UNREGISTERED:
        break;
    case SIP_REGISTRATION_REGISTERED:
        str = "Registered";
        break;
    case SIP_REGISTRATION_REJECTED_TEMPORARY:
    case SIP_REGISTRATION_REJECTED_PERMANENT:
        str = "Rejected";
        break;
    }
    return str;
}
 
/*! \brief Outbound registration information */
struct sip_outbound_registration {
    /*! \brief Sorcery object details */
    SORCERY_OBJECT(details);
    /*! \brief Stringfields */
    AST_DECLARE_STRING_FIELDS(
        /*! \brief URI for the registrar */
        AST_STRING_FIELD(server_uri);
        /*! \brief URI for the AOR */
        AST_STRING_FIELD(client_uri);
        /*! \brief Optional user for contact header */
        AST_STRING_FIELD(contact_user);
        /*! \brief Optional header parameters for contact */
        AST_STRING_FIELD(contact_header_params);
        /*! \brief Explicit transport to use for registration */
        AST_STRING_FIELD(transport);
        /*! \brief Outbound proxy to use */
        AST_STRING_FIELD(outbound_proxy);
        /*! \brief Endpoint to use for related incoming calls */
        AST_STRING_FIELD(endpoint);
        /*! \brief User-Agent to use when sending the REGISTER */
        AST_STRING_FIELD(user_agent);
    );
    /*! \brief Requested expiration time */
    unsigned int expiration;
    /*! \brief Maximum random initial delay interval for initial registrations */
    unsigned int max_random_initial_delay;
    /*! \brief Interval at which retries should occur for temporal responses */
    unsigned int retry_interval;
    /*! \brief Interval at which retries should occur for permanent responses */
    unsigned int forbidden_retry_interval;
    /*! \brief Interval at which retries should occur for all permanent responses */
    unsigned int fatal_retry_interval;
    /*! \brief Treat authentication challenges that we cannot handle as permanent failures */
    unsigned int auth_rejection_permanent;
    /*! \brief Maximum number of retries permitted */
    unsigned int max_retries;
    /*! \brief Whether to add a line parameter to the outbound Contact or not */
    unsigned int line;
    /*! \brief Type of security negotiation to use (RFC 3329). */
    enum ast_sip_security_negotiation security_negotiation;
    /*! \brief Client security mechanisms (RFC 3329). */
    struct ast_sip_security_mechanism_vector security_mechanisms;
    /*! \brief Configured authentication credentials */
    struct ast_sip_auth_vector outbound_auths;
    /*! \brief Whether Path support is enabled */
    unsigned int support_path;
    /*! \brief Whether Outbound support is enabled */
    unsigned int support_outbound;
};
 
/*! \brief Outbound registration client state information (persists for lifetime of regc) */
struct sip_outbound_registration_client_state {
    /*! \brief Current state of this registration */
    enum sip_outbound_registration_status status;
    /*!
     * \brief Outbound registration client
     * \note May only be accessed within the serializer thread
     * because it might get destroyed and set to NULL for
     * module unload.
     */
    pjsip_regc *client;
    /*!
     * \brief Last tdata sent
     * We need the original tdata to resend a request on auth failure
     * or timeout.  On an auth failure, we use the original tdata
     * to initialize the new tdata for the authorized response.  On a timeout
     * we need it to skip failed SRV entries if any.
     */
    pjsip_tx_data *last_tdata;
    /*! \brief Timer entry for retrying on temporal responses */
    pj_timer_entry timer;
    /*! \brief Optional line parameter placed into Contact */
    char line[LINE_PARAMETER_SIZE];
    /*! \brief Current number of retries */
    unsigned int retries;
    /*! \brief Maximum number of retries permitted */
    unsigned int max_retries;
    /*! \brief Interval at which retries should occur for temporal responses */
    unsigned int retry_interval;
    /*! \brief Interval at which retries should occur for permanent responses */
    unsigned int forbidden_retry_interval;
    /*! \brief Interval at which retries should occur for all permanent responses */
    unsigned int fatal_retry_interval;
    /*! \brief Treat authentication challenges that we cannot handle as permanent failures */
    unsigned int auth_rejection_permanent;
    /*! \brief Determines whether SIP Path support should be advertised */
    unsigned int support_path;
    /*! \brief Determines whether SIP Outbound support should be advertised */
    unsigned int support_outbound;
    /*! \brief Type of security negotiation to use (RFC 3329). */
    enum ast_sip_security_negotiation security_negotiation;
    /*! \brief Client security mechanisms (RFC 3329). */
    struct ast_sip_security_mechanism_vector security_mechanisms;
    /*! \brief Security mechanisms of the peer (RFC 3329). */
    struct ast_sip_security_mechanism_vector server_security_mechanisms;
    /*! CSeq number of last sent auth request. */
    unsigned int auth_cseq;
    /*! \brief Serializer for stuff and things */
    struct ast_taskprocessor *serializer;
    /*! \brief Configured authentication credentials */
    struct ast_sip_auth_vector outbound_auths;
    /*! \brief Registration should be destroyed after completion of transaction */
    unsigned int destroy:1;
    /*! \brief Non-zero if we have attempted sending a REGISTER with authentication */
    unsigned int auth_attempted:1;
    /*! \brief Status code of last response if we have tried to register before */
    int last_status_code;
    /*! \brief The name of the transport to be used for the registration */
    char *transport_name;
    /*! \brief The name of the registration sorcery object */
    char *registration_name;
    /*! \brief Expected time of registration lapse/expiration */
    unsigned int registration_expires;
    /*! \brief The value for the User-Agent header sent in requests */
    char *user_agent;
};
 
/*! \brief Outbound registration state information (persists for lifetime that registration should exist) */
struct sip_outbound_registration_state {
    /*! \brief Outbound registration configuration object */
    struct sip_outbound_registration *registration;
    /*! \brief Client state information */
    struct sip_outbound_registration_client_state *client_state;
};
 
/*! Time needs to be long enough for a transaction to timeout if nothing replies. */
#define MAX_UNLOAD_TIMEOUT_TIME     35  /* Seconds */
 
/*! Shutdown group to monitor sip_outbound_registration_client_state serializers. */
static struct ast_serializer_shutdown_group *shutdown_group;
 
/*! \brief Default number of state container buckets */
#define DEFAULT_STATE_BUCKETS 53
static AO2_GLOBAL_OBJ_STATIC(current_states);
 
/*! subscription id for network change events */
static struct stasis_subscription *network_change_sub;
 
/*! \brief hashing function for state objects */
static int registration_state_hash(const void *obj, const int flags)
{
    const struct sip_outbound_registration_state *object;
    const char *key;
 
    switch (flags & OBJ_SEARCH_MASK) {
    case OBJ_SEARCH_KEY:
        key = obj;
        break;
    case OBJ_SEARCH_OBJECT:
        object = obj;
        key = ast_sorcery_object_get_id(object->registration);
        break;
    default:
        ast_assert(0);
        return 0;
    }
    return ast_str_hash(key);
}
 
/*! \brief comparator function for state objects */
static int registration_state_cmp(void *obj, void *arg, int flags)
{
    const struct sip_outbound_registration_state *object_left = obj;
    const struct sip_outbound_registration_state *object_right = arg;
    const char *right_key = arg;
    int cmp;
 
    switch (flags & OBJ_SEARCH_MASK) {
    case OBJ_SEARCH_OBJECT:
        right_key = ast_sorcery_object_get_id(object_right->registration);
        /* Fall through */
    case OBJ_SEARCH_KEY:
        cmp = strcmp(ast_sorcery_object_get_id(object_left->registration), right_key);
        break;
    case OBJ_SEARCH_PARTIAL_KEY:
        /* Not supported by container. */
        ast_assert(0);
        return 0;
    default:
        cmp = 0;
        break;
    }
    if (cmp) {
        return 0;
    }
    return CMP_MATCH;
}
 
static struct sip_outbound_registration_state *get_state(const char *id)
{
    struct sip_outbound_registration_state *state = NULL;
    struct ao2_container *states;
 
    states = ao2_global_obj_ref(current_states);
    if (states) {
        state = ao2_find(states, id, OBJ_SEARCH_KEY);
        ao2_ref(states, -1);
    }
    return state;
}
 
static struct ao2_container *get_registrations(void)
{
    struct ao2_container *registrations = ast_sorcery_retrieve_by_fields(
        ast_sip_get_sorcery(), "registration",
        AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
 
    return registrations;
}
 
/*! \brief Callback function for matching an outbound registration based on line */
static int line_identify_relationship(void *obj, void *arg, int flags)
{
    struct sip_outbound_registration_state *state = obj;
    pjsip_param *line = arg;
 
    return !pj_strcmp2(&line->value, state->client_state->line) ? CMP_MATCH : 0;
}
 
static struct pjsip_param *get_uri_option_line(const void *uri)
{
    static const pj_str_t LINE_STR = { "line", 4 };
 
    return ast_sip_pjsip_uri_get_other_param((pjsip_uri *)uri, &LINE_STR);
}
 
/*! \brief Endpoint identifier which uses the 'line' parameter to establish a relationship to an outgoing registration */
static struct ast_sip_endpoint *line_identify(pjsip_rx_data *rdata)
{
    pjsip_param *line;
    RAII_VAR(struct ao2_container *, states, NULL, ao2_cleanup);
    RAII_VAR(struct sip_outbound_registration_state *, state, NULL, ao2_cleanup);
 
    if (!(line = get_uri_option_line(rdata->msg_info.to->uri))
        && !(line = get_uri_option_line(rdata->msg_info.msg->line.req.uri))) {
        return NULL;
    }
 
    states = ao2_global_obj_ref(current_states);
    if (!states) {
        return NULL;
    }
 
    state = ao2_callback(states, 0, line_identify_relationship, line);
    if (!state || ast_strlen_zero(state->registration->endpoint)) {
        return NULL;
    }
 
    ast_debug(3, "Determined relationship to outbound registration '%s' based on line '%s', using configured endpoint '%s'\n",
        ast_sorcery_object_get_id(state->registration), state->client_state->line, state->registration->endpoint);
 
    return ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", state->registration->endpoint);
}
 
static struct ast_sip_endpoint_identifier line_identifier = {
    .identify_endpoint = line_identify,
};
 
/*! \brief Helper function which cancels the timer on a client */
static void cancel_registration(struct sip_outbound_registration_client_state *client_state)
{
    if (pj_timer_heap_cancel_if_active(pjsip_endpt_get_timer_heap(ast_sip_get_pjsip_endpoint()),
        &client_state->timer, client_state->timer.id)) {
        /* The timer was successfully cancelled, drop the refcount of client_state */
        ao2_ref(client_state, -1);
    }
}
 
static pj_str_t PATH_NAME = { "path", 4 };
static pj_str_t OUTBOUND_NAME = { "outbound", 8 };
 
AST_VECTOR(pjsip_generic_string_hdr_vector, pjsip_generic_string_hdr *);
 
/*!
 * \internal
 * \brief Callback function which finds a contact whose contact_status has security mechanisms.
 *
 * \param obj Pointer to the ast_sip_contact.
 * \param arg Pointer-pointer to a contact_status that will be set to the contact_status found by this function.
 * \param flags Flags used by the ao2_callback function.
 *
 * \note The refcount of the found contact_status must be decremented by the caller.
 */
static int contact_has_security_mechanisms(void *obj, void *arg, int flags)
{
    struct ast_sip_contact *contact = obj;
    struct ast_sip_contact_status **ret = arg;
    struct ast_sip_contact_status *contact_status = ast_sip_get_contact_status(contact);
 
    if (!contact_status) {
        return -1;
    }
    if (!AST_VECTOR_SIZE(&contact_status->security_mechanisms)) {
        ao2_cleanup(contact_status);
        return -1;
    }
    *ret = contact_status;
    return 0;
}
 
static int contact_add_security_headers_to_status(void *obj, void *arg, int flags)
{
    struct ast_sip_contact *contact = obj;
    struct pjsip_generic_string_hdr_vector *header_vector = arg;
    struct ast_sip_contact_status *contact_status = ast_sip_get_contact_status(contact);
 
    if (!contact_status) {
        return -1;
    }
    if (AST_VECTOR_SIZE(&contact_status->security_mechanisms)) {
        goto out;
    }
 
    ao2_lock(contact_status);
    AST_VECTOR_CALLBACK_VOID(header_vector, ast_sip_header_to_security_mechanism, &contact_status->security_mechanisms);
    ao2_unlock(contact_status);
 
out:
    ao2_cleanup(contact_status);
    return 0;
}
 
/*! \brief Adds security negotiation mechanisms of outbound registration client state as Security headers to tdata. */
static void add_security_headers(struct sip_outbound_registration_client_state *client_state,
    pjsip_tx_data *tdata)
{
    int add_sec_client_header = 0;
    struct sip_outbound_registration *reg = NULL;
    struct ast_sip_endpoint *endpt = NULL;
    struct ao2_container *contact_container;
    struct ast_sip_contact_status *contact_status = NULL;
    struct ast_sip_security_mechanism_vector *sec_mechs = NULL;
    static const pj_str_t security_verify = { "Security-Verify", 15 };
    static const pj_str_t security_client = { "Security-Client", 15 };
 
    if (client_state->security_negotiation != AST_SIP_SECURITY_NEG_MEDIASEC) {
        return;
    }
 
    /* Get contact status through registration -> endpoint name -> aor -> contact (if set) */
    if ((reg = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration", client_state->registration_name))
        && !ast_strlen_zero(reg->endpoint) && (endpt = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", reg->endpoint))
        && (contact_container = ast_sip_location_retrieve_contacts_from_aor_list(endpt->aors))) {
        /* Retrieve all contacts associated with aors from this endpoint
         * and find the first one that has security mechanisms.
         */
        ao2_callback(contact_container, 0, contact_has_security_mechanisms, &contact_status);
        if (contact_status) {
            ao2_lock(contact_status);
            sec_mechs = &contact_status->security_mechanisms;
        }
        ao2_cleanup(contact_container);
    }
    /* Use client_state->server_security_mechanisms if contact_status does not exist. */
    if (!contact_status && AST_VECTOR_SIZE(&client_state->server_security_mechanisms)) {
        sec_mechs = &client_state->server_security_mechanisms;
    }
    if (client_state->status == SIP_REGISTRATION_REJECTED_TEMPORARY || client_state->auth_attempted) {
        if (sec_mechs != NULL && pjsip_msg_find_hdr_by_name(tdata->msg, &security_verify, NULL) == NULL) {
            ast_sip_add_security_headers(sec_mechs, "Security-Verify", 0, tdata);
        }
        if (client_state->last_status_code == 494) {
            ast_sip_remove_headers_by_name_and_value(tdata->msg, &security_client, NULL);
        } else {
            /* necessary if a retry occures */
            add_sec_client_header = (pjsip_msg_find_hdr_by_name(tdata->msg, &security_client, NULL) == NULL) ? 1 : 0;
        }
    } else {
        ast_sip_add_security_headers(&client_state->security_mechanisms, "Security-Client", 0, tdata);
    }
 
    if (add_sec_client_header) {
        ast_sip_add_security_headers(&client_state->security_mechanisms, "Security-Client", 0, tdata);
    }
 
    /* Cleanup */
    if (contact_status) {
        ao2_unlock(contact_status);
        ao2_cleanup(contact_status);
    }
    ao2_cleanup(endpt);
    ao2_cleanup(reg);
}
 
/*! \brief Helper function which sends a message and cleans up, if needed, on failure */
static pj_status_t registration_client_send(struct sip_outbound_registration_client_state *client_state,
    pjsip_tx_data *tdata)
{
    pj_status_t status;
    int *callback_invoked;
    pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };
 
    callback_invoked = ast_threadstorage_get(&register_callback_invoked, sizeof(int));
    if (!callback_invoked) {
        pjsip_tx_data_dec_ref(tdata);
        return PJ_ENOMEM;
    }
    *callback_invoked = 0;
 
    /* Due to the message going out the callback may now be invoked, so bump the count */
    ao2_ref(client_state, +1);
    /*
     * We also bump tdata in expectation of saving it to client_state->last_tdata.
     * We have to do it BEFORE pjsip_regc_send because if it succeeds, it decrements
     * the ref count on its own.
     */
    pjsip_tx_data_add_ref(tdata);
 
    /* Add Security-Verify or Security-Client headers */
    add_security_headers(client_state, tdata);
 
    /*
     * Replace the User-Agent header if a different one should be used
     */
    if (!ast_strlen_zero(client_state->user_agent)) {
        static const pj_str_t user_agent_str = { "User-Agent", 10 };
        pjsip_generic_string_hdr *default_user_agent_hdr;
        pjsip_generic_string_hdr *user_agent_hdr;
        pj_str_t user_agent_val;
        default_user_agent_hdr = pjsip_msg_find_hdr_by_name(tdata->msg, &user_agent_str, NULL);
        user_agent_val = pj_str(client_state->user_agent);
        user_agent_hdr = pjsip_generic_string_hdr_create(tdata->pool, &user_agent_str, &user_agent_val);
        if (!user_agent_hdr) {
            ast_log(LOG_ERROR, "Could not add custom User-Agent to outbound registration %s, sending REGISTER request with non-custom header\n", client_state->registration_name);
        } else {
            if (default_user_agent_hdr) {
                pj_list_erase(default_user_agent_hdr);
            }
            pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)user_agent_hdr);
        }
    }
 
    /*
     * Set the transport in case transports were reloaded.
     * When pjproject removes the extraneous error messages produced,
     * we can check status and only set the transport and resend if there was an error
     */
    ast_sip_set_tpselector_from_transport_name(client_state->transport_name, &selector);
    pjsip_regc_set_transport(client_state->client, &selector);
    ast_sip_tpselector_unref(&selector);
 
    status = pjsip_regc_send(client_state->client, tdata);
 
    /*
     * If the attempt to send the message failed and the callback was not invoked we need to
     * drop the references we just added
     */
    if ((status != PJ_SUCCESS) && !(*callback_invoked)) {
        pjsip_tx_data_dec_ref(tdata);
        ao2_ref(client_state, -1);
        return status;
    }
 
    /*
     * Decref the old last_data before replacing it.
     * BTW, it's quite possible that last_data == tdata
     * if we're trying successive servers in an SRV set.
     */
    if (client_state->last_tdata) {
        pjsip_tx_data_dec_ref(client_state->last_tdata);
    }
    client_state->last_tdata = tdata;
 
    return status;
}
 
/*! \brief Helper function to add string to Supported header */
static int add_to_supported_header(pjsip_tx_data *tdata, pj_str_t *name)
{
    pjsip_supported_hdr *hdr;
    int i;
 
    hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
    if (!hdr) {
        /* insert a new Supported header */
        hdr = pjsip_supported_hdr_create(tdata->pool);
        if (!hdr) {
            pjsip_tx_data_dec_ref(tdata);
            return 0;
        }
 
        pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
    }
 
    /* Don't add the value if it's already there */
    for (i = 0; i < hdr->count; ++i) {
        if (pj_stricmp(&hdr->values[i], name) == 0) {
            return 1;
        }
    }
 
    if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
        return 0;
    }
 
    /* add on to the existing Supported header */
    pj_strassign(&hdr->values[hdr->count++], name);
 
    return 1;
}
 
/*! \brief Helper function to add configured supported headers */
static int add_configured_supported_headers(struct sip_outbound_registration_client_state *client_state, pjsip_tx_data *tdata)
{
    if (client_state->support_path) {
        if (!add_to_supported_header(tdata, &PATH_NAME)) {
            return 0;
        }
    }
 
    if (client_state->support_outbound) {
        if (!add_to_supported_header(tdata, &OUTBOUND_NAME)) {
            return 0;
        }
    }
 
    return 1;
}
 
/*! \brief Callback function for registering */
static int handle_client_registration(void *data)
{
    RAII_VAR(struct sip_outbound_registration_client_state *, client_state, data, ao2_cleanup);
    pjsip_tx_data *tdata;
 
    if (set_outbound_initial_authentication_credentials(client_state->client, &client_state->outbound_auths)) {
        ast_log(LOG_WARNING, "Failed to set initial authentication credentials\n");
    }
 
    if (client_state->status == SIP_REGISTRATION_STOPPED
        || pjsip_regc_register(client_state->client, PJ_FALSE, &tdata) != PJ_SUCCESS) {
        return 0;
    }
 
    if (DEBUG_ATLEAST(1)) {
        pjsip_regc_info info;
 
        pjsip_regc_get_info(client_state->client, &info);
        ast_log(LOG_DEBUG, "Outbound REGISTER attempt %u to '%.*s' with client '%.*s'\n",
            client_state->retries + 1,
            (int) info.server_uri.slen, info.server_uri.ptr,
            (int) info.client_uri.slen, info.client_uri.ptr);
    }
 
    if (!add_configured_supported_headers(client_state, tdata)) {
        ast_log(LOG_WARNING, "Failed to set supported headers\n");
        return -1;
    }
 
    registration_client_send(client_state, tdata);
 
    return 0;
}
 
/*! \brief Timer callback function, used just for registrations */
static void sip_outbound_registration_timer_cb(pj_timer_heap_t *timer_heap, struct pj_timer_entry *entry)
{
    struct sip_outbound_registration_client_state *client_state = entry->user_data;
 
    entry->id = 0;
 
    /*
     * Transfer client_state reference to serializer task so the
     * nominal path will not dec the client_state ref in this
     * pjproject callback thread.
     */
    if (ast_sip_push_task(client_state->serializer, handle_client_registration, client_state)) {
        ast_log(LOG_WARNING, "Scheduled outbound registration could not be executed.\n");
        ao2_ref(client_state, -1);
    }
}
 
/*! \brief Helper function which sets up the timer to re-register in a specific amount of time */
static void schedule_registration(struct sip_outbound_registration_client_state *client_state, unsigned int seconds)
{
    pj_time_val delay = { .sec = seconds, };
    pjsip_regc_info info;
 
    cancel_registration(client_state);
 
    pjsip_regc_get_info(client_state->client, &info);
    ast_debug(1, "Scheduling outbound registration to server '%.*s' from client '%.*s' in %d seconds\n",
            (int) info.server_uri.slen, info.server_uri.ptr,
            (int) info.client_uri.slen, info.client_uri.ptr,
            seconds);
 
    ao2_ref(client_state, +1);
    if (pjsip_endpt_schedule_timer(ast_sip_get_pjsip_endpoint(), &client_state->timer, &delay) != PJ_SUCCESS) {
        ast_log(LOG_WARNING, "Failed to schedule registration to server '%.*s' from client '%.*s'\n",
                (int) info.server_uri.slen, info.server_uri.ptr,
                (int) info.client_uri.slen, info.client_uri.ptr);
        ao2_ref(client_state, -1);
    }
    client_state->registration_expires = ((int) time(NULL)) + seconds;
}
 
static void update_client_state_status(struct sip_outbound_registration_client_state *client_state, enum sip_outbound_registration_status status)
{
    const char *status_old;
    const char *status_new;
 
    if (client_state->status == status) {
        /* Status state did not change at all. */
        return;
    }
 
    status_old = sip_outbound_registration_status_str(client_state->status);
    status_new = sip_outbound_registration_status_str(status);
    client_state->status = status;
 
    if (!strcmp(status_old, status_new)) {
        /*
         * The internal status state may have changed but the status
         * state we tell the world did not change at all.
         */
        return;
    }
 
    ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "-1", 1.0,
        status_old);
    ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "+1", 1.0,
        status_new);
}
 
/*! \brief Callback function for unregistering (potentially) and destroying state */
static int handle_client_state_destruction(void *data)
{
    struct sip_outbound_registration_client_state *client_state = data;
 
    cancel_registration(client_state);
 
    if (client_state->client) {
        pjsip_regc_info info;
        pjsip_tx_data *tdata;
 
        pjsip_regc_get_info(client_state->client, &info);
 
        if (info.is_busy == PJ_TRUE) {
            /* If a client transaction is in progress we defer until it is complete */
            ast_debug(1,
                "Registration transaction is busy with server '%.*s' from client '%.*s'.\n",
                (int) info.server_uri.slen, info.server_uri.ptr,
                (int) info.client_uri.slen, info.client_uri.ptr);
            client_state->destroy = 1;
            ao2_ref(client_state, -1);
            return 0;
        }
 
        switch (client_state->status) {
        case SIP_REGISTRATION_UNREGISTERED:
            break;
        case SIP_REGISTRATION_REGISTERED:
            ast_debug(1,
                "Trying to unregister with server '%.*s' from client '%.*s' before destruction.\n",
                (int) info.server_uri.slen, info.server_uri.ptr,
                (int) info.client_uri.slen, info.client_uri.ptr);
 
            update_client_state_status(client_state, SIP_REGISTRATION_STOPPING);
            client_state->destroy = 1;
            if (pjsip_regc_unregister(client_state->client, &tdata) == PJ_SUCCESS
                && add_configured_supported_headers(client_state, tdata)
                && registration_client_send(client_state, tdata) == PJ_SUCCESS) {
                ao2_ref(client_state, -1);
                return 0;
            }
            break;
        case SIP_REGISTRATION_REJECTED_TEMPORARY:
        case SIP_REGISTRATION_REJECTED_PERMANENT:
        case SIP_REGISTRATION_STOPPING:
        case SIP_REGISTRATION_STOPPED:
            break;
        }
 
        pjsip_regc_destroy(client_state->client);
        client_state->client = NULL;
    }
 
    update_client_state_status(client_state, SIP_REGISTRATION_STOPPED);
    ast_sip_auth_vector_destroy(&client_state->outbound_auths);
    ast_sip_security_mechanisms_vector_destroy(&client_state->security_mechanisms);
    ast_sip_security_mechanisms_vector_destroy(&client_state->server_security_mechanisms);
    ao2_ref(client_state, -1);
 
    return 0;
}
 
/*! \brief Structure for registration response */
struct registration_response {
    /*! \brief Response code for the registration attempt */
    int code;
    /*! \brief Expiration time for registration */
    int expiration;
    /*! \brief Retry-After value */
    int retry_after;
    /*! \brief Outbound registration client state */
    struct sip_outbound_registration_client_state *client_state;
    /*! \brief The response message */
    pjsip_rx_data *rdata;
    /*! \brief Request for which the response was received */
    pjsip_tx_data *old_request;
    /*! \brief Key for the reliable transport in use */
    char transport_key[IP6ADDR_COLON_PORT_BUFLEN];
};
 
/*! \brief Registration response structure destructor */
static void registration_response_destroy(void *obj)
{
    struct registration_response *response = obj;
 
    if (response->rdata) {
        pjsip_rx_data_free_cloned(response->rdata);
    }
 
    if (response->old_request) {
        pjsip_tx_data_dec_ref(response->old_request);
    }
 
    ao2_cleanup(response->client_state);
}
 
/*! \brief Helper function which determines if a response code is temporal or not */
static int sip_outbound_registration_is_temporal(unsigned int code,
        struct sip_outbound_registration_client_state *client_state)
{
    /* Shamelessly taken from pjsua */
    if (code == PJSIP_SC_REQUEST_TIMEOUT ||
        code == PJSIP_SC_INTERNAL_SERVER_ERROR ||
        code == PJSIP_SC_BAD_GATEWAY ||
        code == PJSIP_SC_SERVICE_UNAVAILABLE ||
        code == PJSIP_SC_SERVER_TIMEOUT ||
        ((code == PJSIP_SC_UNAUTHORIZED ||
          code == PJSIP_SC_PROXY_AUTHENTICATION_REQUIRED) &&
         !client_state->auth_rejection_permanent) ||
        PJSIP_IS_STATUS_IN_CLASS(code, 600)) {
        return 1;
    } else {
        return 0;
    }
}
 
static void schedule_retry(struct registration_response *response, unsigned int interval,
               const char *server_uri, const char *client_uri)
{
    update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
    schedule_registration(response->client_state, interval);
 
    if (response->rdata) {
        ast_log(LOG_WARNING, "Temporal response '%d' received from '%s' on "
            "registration attempt to '%s', retrying in '%u'\n",
            response->code, server_uri, client_uri, interval);
    } else {
        ast_log(LOG_WARNING, "No response received from '%s' on "
            "registration attempt to '%s', retrying in '%u'\n",
            server_uri, client_uri, interval);
    }
}
 
static int reregister_immediately_cb(void *obj)
{
    struct sip_outbound_registration_state *state = obj;
 
    if (state->client_state->status != SIP_REGISTRATION_REGISTERED) {
        ao2_ref(state, -1);
        return 0;
    }
 
    if (DEBUG_ATLEAST(1)) {
        pjsip_regc_info info;
 
        pjsip_regc_get_info(state->client_state->client, &info);
        ast_log(LOG_DEBUG,
            "Outbound registration transport to server '%.*s' from client '%.*s' shutdown\n",
            (int) info.server_uri.slen, info.server_uri.ptr,
            (int) info.client_uri.slen, info.client_uri.ptr);
    }
 
    cancel_registration(state->client_state);
 
    ao2_ref(state->client_state, +1);
    handle_client_registration(state->client_state);
 
    ao2_ref(state, -1);
    return 0;
}
 
/*!
 * \internal
 * \brief The reliable transport we registered using has shutdown.
 * \since 13.18.0
 *
 * \param obj What is needed to initiate a reregister attempt.
 *
 * \note Normally executed by the pjsip monitor thread.
 */
static void registration_transport_shutdown_cb(void *obj)
{
    const char *registration_name = obj;
    struct sip_outbound_registration_state *state;
 
    state = get_state(registration_name);
    if (!state) {
        /* Registration no longer exists or shutting down. */
        return;
    }
    if (ast_sip_push_task(state->client_state->serializer, reregister_immediately_cb, state)) {
        ao2_ref(state, -1);
    }
}
 
static int monitor_matcher(void *a, void *b)
{
    char *ma = a;
    char *mb = b;
 
    return strcmp(ma, mb) == 0;
}
 
static void registration_transport_monitor_setup(const char *transport_key, const char *registration_name)
{
    char *monitor;
 
    monitor = ao2_alloc_options(strlen(registration_name) + 1, NULL,
        AO2_ALLOC_OPT_LOCK_NOLOCK);
    if (!monitor) {
        return;
    }
    strcpy(monitor, registration_name);/* Safe */
 
    /*
     * We'll ignore if the transport has already been shutdown before we
     * register the monitor.  We might get into a message spamming infinite
     * loop of registration, shutdown, reregistration...
     */
    ast_sip_transport_monitor_register_replace_key(transport_key, registration_transport_shutdown_cb,
        monitor, monitor_matcher);
    ao2_ref(monitor, -1);
}
 
static void save_response_fields_to_transport(struct registration_response *response)
{
    static const pj_str_t associated_uri_str = { "P-Associated-URI", 16 };
    static const pj_str_t service_route_str = { "Service-Route", 13 };
    pjsip_hdr *header = NULL;
    pjsip_msg *msg = response->rdata->msg_info.msg;
    struct ast_sip_service_route_vector *service_routes = NULL;
 
    /* If no transport is specified then we can't update any */
    if (ast_strlen_zero(response->client_state->transport_name)) {
        return;
    }
 
    ast_sip_transport_state_set_transport(response->client_state->transport_name, response->rdata->tp_info.transport);
 
    while ((header = pjsip_msg_find_hdr_by_name(msg, &service_route_str, header ? header->next : NULL))) {
        char *service_route;
        size_t size;
 
        /* The below code takes the approach that if we can't store all service routes then we
         * store none at all. This gives a predictable failure condition instead of storing a
         * partial list and having partial route headers.
         */
        size = pj_strlen(&((pjsip_generic_string_hdr*)header)->hvalue) + 1;
        service_route = ast_malloc(size);
        if (!service_route) {
            if (service_routes) {
                ast_sip_service_route_vector_destroy(service_routes);
                service_routes = NULL;
            }
            break;
        }
 
        ast_copy_pj_str(service_route, &((pjsip_generic_string_hdr*)header)->hvalue, size);
 
        if (!service_routes) {
            service_routes = ast_sip_service_route_vector_alloc();
            if (!service_routes) {
                ast_free(service_route);
                break;
            }
        }
 
        if (AST_VECTOR_APPEND(service_routes, service_route)) {
            ast_free(service_route);
            ast_sip_service_route_vector_destroy(service_routes);
            service_routes = NULL;
            break;
        }
    }
 
    /* If any service routes were handled then store them on the transport */
    if (service_routes) {
        ast_sip_transport_state_set_service_routes(response->client_state->transport_name, service_routes);
    }
 
    /* If an associated URI is present in the response we need to use it on any outgoing
     * traffic on the transport.
     */
    header = pjsip_msg_find_hdr_by_name(msg, &associated_uri_str, NULL);
    if (header) {
        char value[pj_strlen(&((pjsip_generic_string_hdr*)header)->hvalue) + 1];
 
        ast_copy_pj_str(value, &((pjsip_generic_string_hdr*)header)->hvalue, sizeof(value));
        ast_sip_transport_state_set_preferred_identity(response->client_state->transport_name, value);
    }
}
 
 
/*! \brief Callback function for handling a response to a registration attempt */
static int handle_registration_response(void *data)
{
    struct registration_response *response = data;
    pjsip_regc_info info;
    char server_uri[PJSIP_MAX_URL_SIZE];
    char client_uri[PJSIP_MAX_URL_SIZE];
 
    if (response->client_state->status == SIP_REGISTRATION_STOPPED) {
        ao2_ref(response, -1);
        return 0;
    }
 
    pjsip_regc_get_info(response->client_state->client, &info);
    ast_copy_pj_str(server_uri, &info.server_uri, sizeof(server_uri));
    ast_copy_pj_str(client_uri, &info.client_uri, sizeof(client_uri));
    response->client_state->last_status_code = response->code;
 
    ast_debug(1, "Processing REGISTER response %d from server '%s' for client '%s'\n",
            response->code, server_uri, client_uri);
 
    if (response->code == 408 || response->code == 503) {
        if ((ast_sip_failover_request(response->old_request))) {
            int res = registration_client_send(response->client_state, response->old_request);
            /* The tdata ref was stolen */
            response->old_request = NULL;
            if (res == PJ_SUCCESS) {
                ao2_ref(response, -1);
                return 0;
            }
        }
    } else if ((response->code == 401 || response->code == 407 || response->code == 494)
        && (!response->client_state->auth_attempted
            || response->rdata->msg_info.cseq->cseq != response->client_state->auth_cseq)) {
        int res;
        pjsip_cseq_hdr *cseq_hdr;
        pjsip_tx_data *tdata;
 
        if (response->client_state->security_negotiation == AST_SIP_SECURITY_NEG_MEDIASEC) {
            struct sip_outbound_registration *reg = NULL;
            struct ast_sip_endpoint *endpt = NULL;
            struct ao2_container *contact_container = NULL;
            pjsip_generic_string_hdr *header;
            struct pjsip_generic_string_hdr_vector header_vector;
            static const pj_str_t security_server = { "Security-Server", 15 };
 
            if ((reg = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration",
                response->client_state->registration_name)) && reg->endpoint &&
                (endpt = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", reg->endpoint))) {
                /* Retrieve all contacts associated with aors from this endpoint (if set). */
                contact_container = ast_sip_location_retrieve_contacts_from_aor_list(endpt->aors);
            }
            /* Add server list of security mechanism to client_state and contact status if exists. */
            AST_VECTOR_INIT(&header_vector, 1);
            header = pjsip_msg_find_hdr_by_name(response->rdata->msg_info.msg, &security_server, NULL);
            for (; header;
                header = pjsip_msg_find_hdr_by_name(response->rdata->msg_info.msg, &security_server, header->next)) {
                AST_VECTOR_APPEND(&header_vector, header);
                ast_sip_header_to_security_mechanism(header, &response->client_state->server_security_mechanisms);
            }
            if (contact_container) {
                /* Add server security mechanisms to contact status of all associated contacts to be able to send correct
                 * Security-Verify headers on subsequent non-REGISTER requests through this outbound registration.
                 */
                ao2_callback(contact_container, OBJ_NODATA, contact_add_security_headers_to_status, &header_vector);
                ao2_cleanup(contact_container);
            }
            AST_VECTOR_FREE(&header_vector);
            ao2_cleanup(endpt);
            ao2_cleanup(reg);
        }
 
        if (response->code == 494) {
            update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
            response->client_state->retries++;
            schedule_registration(response->client_state, 0);
            ao2_ref(response, -1);
            return 0;
        } else if (!ast_sip_create_request_with_auth(&response->client_state->outbound_auths,
                response->rdata, response->old_request, &tdata)) {
            response->client_state->auth_attempted = 1;
            ast_debug(1, "Sending authenticated REGISTER to server '%s' from client '%s'\n",
                    server_uri, client_uri);
            pjsip_tx_data_add_ref(tdata);
 
            res = registration_client_send(response->client_state, tdata);
 
            /* Save the cseq that actually got sent. */
            cseq_hdr = (pjsip_cseq_hdr *) pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ,
                NULL);
            response->client_state->auth_cseq = cseq_hdr->cseq;
            pjsip_tx_data_dec_ref(tdata);
            if (res == PJ_SUCCESS) {
                ao2_ref(response, -1);
                return 0;
            }
        } else {
            ast_log(LOG_WARNING, "Failed to create authenticated REGISTER request to server '%s' from client '%s'\n",
                    server_uri, client_uri);
        }
        /* Otherwise, fall through so the failure is processed appropriately */
    }
 
    response->client_state->auth_attempted = 0;
 
    if (PJSIP_IS_STATUS_IN_CLASS(response->code, 200)) {
        /* Check if this is in regards to registering or unregistering */
        if (response->expiration) {
            int next_registration_round;
 
            /* If the registration went fine simply reschedule registration for the future */
            ast_debug(1, "Outbound registration to '%s' with client '%s' successful\n", server_uri, client_uri);
            update_client_state_status(response->client_state, SIP_REGISTRATION_REGISTERED);
            response->client_state->retries = 0;
            next_registration_round = response->expiration - REREGISTER_BUFFER_TIME;
            if (next_registration_round < 0) {
                /* Re-register immediately. */
                next_registration_round = 0;
            }
            schedule_registration(response->client_state, next_registration_round);
 
            /* See if we should monitor for transport shutdown */
            if (PJSIP_TRANSPORT_IS_RELIABLE(response->rdata->tp_info.transport)) {
                registration_transport_monitor_setup(response->transport_key,
                    response->client_state->registration_name);
            }
        } else {
            ast_debug(1, "Outbound unregistration to '%s' with client '%s' successful\n", server_uri, client_uri);
            update_client_state_status(response->client_state, SIP_REGISTRATION_UNREGISTERED);
            if (PJSIP_TRANSPORT_IS_RELIABLE(response->rdata->tp_info.transport)) {
                ast_sip_transport_monitor_unregister_key(response->transport_key,
                    registration_transport_shutdown_cb, response->client_state->registration_name,
                    monitor_matcher);
            }
        }
 
        save_response_fields_to_transport(response);
    } else if (response->client_state->destroy) {
        /* We need to deal with the pending destruction instead. */
    } else if (response->retry_after) {
        /* If we have been instructed to retry after a period of time, schedule it as such */
        schedule_retry(response, response->retry_after, server_uri, client_uri);
    } else if (response->client_state->retry_interval
        && sip_outbound_registration_is_temporal(response->code, response->client_state)) {
        if (response->client_state->retries == response->client_state->max_retries) {
            /* If we received enough temporal responses to exceed our maximum give up permanently */
            update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_PERMANENT);
            ast_log(LOG_WARNING, "Maximum retries reached when attempting outbound registration to '%s' with client '%s', stopping registration attempt\n",
                server_uri, client_uri);
        } else {
            /* On the other hand if we can still try some more do so */
            response->client_state->retries++;
            schedule_retry(response, response->client_state->retry_interval, server_uri, client_uri);
        }
    } else {
        if (response->code == 403
            && response->client_state->forbidden_retry_interval
            && response->client_state->retries < response->client_state->max_retries) {
            /* A forbidden response retry interval is configured and there are retries remaining */
            update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
            response->client_state->retries++;
            schedule_registration(response->client_state, response->client_state->forbidden_retry_interval);
            ast_log(LOG_WARNING, "403 Forbidden fatal response received from '%s' on registration attempt to '%s', retrying in '%u' seconds\n",
                server_uri, client_uri, response->client_state->forbidden_retry_interval);
        } else if (response->client_state->fatal_retry_interval
               && response->client_state->retries < response->client_state->max_retries) {
            /* Some kind of fatal failure response received, so retry according to configured interval */
            update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_TEMPORARY);
            response->client_state->retries++;
            schedule_registration(response->client_state, response->client_state->fatal_retry_interval);
            ast_log(LOG_WARNING, "'%d' fatal response received from '%s' on registration attempt to '%s', retrying in '%u' seconds\n",
                response->code, server_uri, client_uri, response->client_state->fatal_retry_interval);
        } else {
            /* Finally if there's no hope of registering give up */
            update_client_state_status(response->client_state, SIP_REGISTRATION_REJECTED_PERMANENT);
            if (response->rdata) {
                ast_log(LOG_WARNING, "Fatal response '%d' received from '%s' on registration attempt to '%s', stopping outbound registration\n",
                    response->code, server_uri, client_uri);
            } else {
                ast_log(LOG_WARNING, "Fatal registration attempt to '%s', stopping outbound registration\n", client_uri);
            }
        }
    }
 
    ast_system_publish_registry("PJSIP", client_uri, server_uri,
        sip_outbound_registration_status_str(response->client_state->status), NULL);
 
    if (response->client_state->destroy) {
        /* We have a pending deferred destruction to complete now. */
        ao2_ref(response->client_state, +1);
        handle_client_state_destruction(response->client_state);
    }
 
    ao2_ref(response, -1);
    return 0;
}
 
/*! \brief Callback function for outbound registration client */
static void sip_outbound_registration_response_cb(struct pjsip_regc_cbparam *param)
{
    struct sip_outbound_registration_client_state *client_state = param->token;
    struct registration_response *response;
    int *callback_invoked;
 
    callback_invoked = ast_threadstorage_get(&register_callback_invoked, sizeof(int));
 
    ast_assert(callback_invoked != NULL);
    ast_assert(client_state != NULL);
 
    *callback_invoked = 1;
 
    response = ao2_alloc(sizeof(*response), registration_response_destroy);
    if (!response) {
        ao2_ref(client_state, -1);
        return;
    }
    response->code = param->code;
    response->expiration = param->expiration;
    /*
     * Transfer client_state reference to response so the
     * nominal path will not dec the client_state ref in this
     * pjproject callback thread.
     */
    response->client_state = client_state;
 
    ast_debug(1, "Received REGISTER response %d(%.*s)\n",
        param->code, (int) param->reason.slen, param->reason.ptr);
 
    if (param->rdata) {
        struct pjsip_retry_after_hdr *retry_after;
        pjsip_transaction *tsx;
 
        retry_after = pjsip_msg_find_hdr(param->rdata->msg_info.msg, PJSIP_H_RETRY_AFTER,
            NULL);
        response->retry_after = retry_after ? retry_after->ivalue : 0;
 
        /*
         * If we got a response from the server, we have to use the tdata
         * from the transaction, not the tdata saved when we sent the
         * request.  If we use the saved tdata, we won't process responses
         * like 423 Interval Too Brief correctly and we'll wind up sending
         * the bad Expires value again.
         */
        pjsip_tx_data_dec_ref(client_state->last_tdata);
 
        tsx = pjsip_rdata_get_tsx(param->rdata);
        response->old_request = tsx->last_tx;
        pjsip_tx_data_add_ref(response->old_request);
        pjsip_rx_data_clone(param->rdata, 0, &response->rdata);
        AST_SIP_MAKE_REMOTE_IPADDR_PORT_STR(param->rdata->tp_info.transport,
            response->transport_key);
 
    } else {
        /* old_request steals the reference */
        response->old_request = client_state->last_tdata;
    }
    client_state->last_tdata = NULL;
 
    /*
     * Transfer response reference to serializer task so the
     * nominal path will not dec the response ref in this
     * pjproject callback thread.
     */
    if (ast_sip_push_task(client_state->serializer, handle_registration_response, response)) {
        ast_log(LOG_WARNING, "Failed to pass incoming registration response to threadpool\n");
        ao2_cleanup(response);
    }
}
 
/*! \brief Destructor function for registration state */
static void sip_outbound_registration_state_destroy(void *obj)
{
    struct sip_outbound_registration_state *state = obj;
 
    ast_debug(3, "Destroying registration state for registration to server '%s' from client '%s'\n",
        state->registration ? state->registration->server_uri : "",
        state->registration ? state->registration->client_uri : "");
    ao2_cleanup(state->registration);
 
    if (!state->client_state) {
        /* Nothing to do */
    } else if (!state->client_state->serializer) {
        ao2_ref(state->client_state, -1);
    } else if (ast_sip_push_task(state->client_state->serializer,
        handle_client_state_destruction, state->client_state)) {
        ast_log(LOG_WARNING, "Failed to pass outbound registration client destruction to threadpool\n");
        ao2_ref(state->client_state, -1);
    }
}
 
/*! \brief Destructor function for client registration state */
static void sip_outbound_registration_client_state_destroy(void *obj)
{
    struct sip_outbound_registration_client_state *client_state = obj;
 
    ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "-1", 1.0);
    ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "-1", 1.0,
        sip_outbound_registration_status_str(client_state->status));
 
    ast_taskprocessor_unreference(client_state->serializer);
    ast_free(client_state->transport_name);
    ast_free(client_state->registration_name);
    ast_free(client_state->user_agent);
    if (client_state->last_tdata) {
        pjsip_tx_data_dec_ref(client_state->last_tdata);
    }
}
 
/*! \brief Allocator function for registration state */
static struct sip_outbound_registration_state *sip_outbound_registration_state_alloc(struct sip_outbound_registration *registration)
{
    struct sip_outbound_registration_state *state;
    char tps_name[AST_TASKPROCESSOR_MAX_NAME + 1];
 
    state = ao2_alloc(sizeof(*state), sip_outbound_registration_state_destroy);
    if (!state) {
        return NULL;
    }
    state->client_state = ao2_alloc(sizeof(*state->client_state),
        sip_outbound_registration_client_state_destroy);
    if (!state->client_state) {
        ao2_cleanup(state);
        return NULL;
    }
 
    state->client_state->status = SIP_REGISTRATION_UNREGISTERED;
    pj_timer_entry_init(&state->client_state->timer, 0, state->client_state,
        sip_outbound_registration_timer_cb);
    state->client_state->transport_name = ast_strdup(registration->transport);
    state->client_state->registration_name =
        ast_strdup(ast_sorcery_object_get_id(registration));
    state->client_state->user_agent = ast_strdup(registration->user_agent);
 
    ast_statsd_log_string("PJSIP.registrations.count", AST_STATSD_GAUGE, "+1", 1.0);
    ast_statsd_log_string_va("PJSIP.registrations.state.%s", AST_STATSD_GAUGE, "+1", 1.0,
        sip_outbound_registration_status_str(state->client_state->status));
 
    if (!state->client_state->transport_name
        || !state->client_state->registration_name) {
        ao2_cleanup(state);
        return NULL;
    }
 
    /* Create name with seq number appended. */
    ast_taskprocessor_build_name(tps_name, sizeof(tps_name), "pjsip/outreg/%s",
        ast_sorcery_object_get_id(registration));
 
    state->client_state->serializer = ast_sip_create_serializer_group(tps_name,
        shutdown_group);
    if (!state->client_state->serializer) {
        ao2_cleanup(state);
        return NULL;
    }
 
    state->registration = ao2_bump(registration);
    return state;
}
 
/*! \brief Destructor function for registration information */
static void sip_outbound_registration_destroy(void *obj)
{
    struct sip_outbound_registration *registration = obj;
 
    ast_sip_auth_vector_destroy(&registration->outbound_auths);
    ast_sip_security_mechanisms_vector_destroy(&registration->security_mechanisms);
 
    ast_string_field_free_memory(registration);
}
 
/*! \brief Allocator function for registration information */
static void *sip_outbound_registration_alloc(const char *name)
{
    struct sip_outbound_registration *registration;
 
    registration = ast_sorcery_generic_alloc(sizeof(*registration),
        sip_outbound_registration_destroy);
    if (!registration || ast_string_field_init(registration, 256)) {
        ao2_cleanup(registration);
        return NULL;
    }
 
    return registration;
}
 
/*! \brief Helper function which populates a pj_str_t with a contact header */
static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const char *user,
    const pj_str_t *target, pjsip_tpselector *selector, const char *line, const char *header_params)
{
    pj_str_t tmp, local_addr;
    pjsip_uri *uri;
    pjsip_sip_uri *sip_uri;
    pjsip_transport_type_e type;
    int local_port;
 
    pj_strdup_with_null(pool, &tmp, target);
 
    if (!(uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0)) ||
        (!PJSIP_URI_SCHEME_IS_SIP(uri) && !PJSIP_URI_SCHEME_IS_SIPS(uri))) {
        return -1;
    }
 
    sip_uri = pjsip_uri_get_uri(uri);
 
    type = pjsip_transport_get_type_from_name(&sip_uri->transport_param);
    if (PJSIP_URI_SCHEME_IS_SIPS(sip_uri)) {
        if (type == PJSIP_TRANSPORT_UNSPECIFIED
            || !(pjsip_transport_get_flag_from_type(type) & PJSIP_TRANSPORT_SECURE)) {
            type = PJSIP_TRANSPORT_TLS;
        }
    } else if (!sip_uri->transport_param.slen) {
        type = PJSIP_TRANSPORT_UDP;
    } else if (type == PJSIP_TRANSPORT_UNSPECIFIED) {
        return -1;
    }
 
    if (pj_strchr(&sip_uri->host, ':')) {
        type |= PJSIP_TRANSPORT_IPV6;
    }
 
    if (pjsip_tpmgr_find_local_addr(pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint()),
        pool, type, selector, &local_addr, &local_port) != PJ_SUCCESS) {
        return -1;
    }
 
    if (!pj_strchr(&sip_uri->host, ':') && pj_strchr(&local_addr, ':')) {
        type |= PJSIP_TRANSPORT_IPV6;
    }
 
    contact->ptr = pj_pool_alloc(pool, PJSIP_MAX_URL_SIZE);
    contact->slen = pj_ansi_snprintf(contact->ptr, PJSIP_MAX_URL_SIZE,
        "<%s:%s@%s%.*s%s:%d%s%s%s%s>%s%s",
        ((pjsip_transport_get_flag_from_type(type) & PJSIP_TRANSPORT_SECURE) && PJSIP_URI_SCHEME_IS_SIPS(uri)) ? "sips" : "sip",
        user,
        (type & PJSIP_TRANSPORT_IPV6) ? "[" : "",
        (int)local_addr.slen,
        local_addr.ptr,
        (type & PJSIP_TRANSPORT_IPV6) ? "]" : "",
        local_port,
        (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? ";transport=" : "",
        (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? pjsip_transport_get_type_name(type) : "",
        !ast_strlen_zero(line) ? ";line=" : "",
        S_OR(line, ""),
        !ast_strlen_zero(header_params) ? ";" : "",
        S_OR(header_params, ""));
 
    return 0;
}
 
/*!
 * \internal
 * \brief Check if a registration can be reused
 *
 * This checks if the existing outbound registration's configuration differs from a newly-applied
 * outbound registration to see if the applied one.
 *
 * \param existing The pre-existing outbound registration
 * \param applied The newly-created registration
 */
static int can_reuse_registration(struct sip_outbound_registration *existing,
    struct sip_outbound_registration *applied)
{
    int rc = 1;
    struct ast_sorcery *sorcery = ast_sip_get_sorcery();
    struct ast_variable *ve = ast_sorcery_objectset_create(sorcery, existing);
    struct ast_variable *va = ast_sorcery_objectset_create(sorcery, applied);
    struct ast_variable *vc = NULL;
 
    if (ast_sorcery_changeset_create(ve, va, &vc) || vc != NULL) {
        rc = 0;
        ast_debug(4, "Registration '%s' changed.  Can't re-use.\n", ast_sorcery_object_get_id(existing));
    } else {
        ast_debug(4, "Registration '%s' didn't change.  Can re-use\n", ast_sorcery_object_get_id(existing));
    }
 
    ast_variables_destroy(ve);
    ast_variables_destroy(va);
    ast_variables_destroy(vc);
 
    return rc;
}
 
/*! \brief Get google oauth2 access token using refresh token */
static const char *fetch_google_access_token(const struct ast_sip_auth *auth)
{
    char *cmd = NULL;
    const char *token;
    const char *url = "https://www.googleapis.com/oauth2/v3/token";
    char buf[4096];
    int res;
    struct ast_json_error error;
    struct ast_json *json;
 
    /* set timeout to be shorter than default 180s (also checks func_curl is available) */
    if (ast_func_write(NULL, "CURLOPT(conntimeout)", "10")) {
        ast_log(LOG_ERROR, "CURL is unavailable. This is required for Google OAuth 2.0 authentication. Please ensure it is loaded.\n");
        return NULL;
    }
 
    res = ast_asprintf(&cmd,
        "CURL(%s,client_id=%s&client_secret=%s&refresh_token=%s&grant_type=refresh_token)",
        url, auth->oauth_clientid, auth->oauth_secret, auth->refresh_token);
    if (res < 0) {
        return NULL;
    }
 
    ast_debug(2, "Performing Google OAuth 2.0 authentication using command: %s\n", cmd);
 
    buf[0] = '\0';
    res = ast_func_read(NULL, cmd, buf, sizeof(buf));
    ast_free(cmd);
    if (res) {
        ast_log(LOG_ERROR, "Could not retrieve Google OAuth 2.0 authentication\n");
        return NULL;
    }
 
    ast_debug(2, "Google OAuth 2.0 authentication returned: %s\n", buf);
 
    json = ast_json_load_string(buf, &error);
    if (!json) {
        ast_log(LOG_ERROR, "Could not parse Google OAuth 2.0 authentication: %d(%d) %s: '%s'\n",
            error.line, error.column, error.text, buf);
        return NULL;
    }
 
    token = ast_json_string_get(ast_json_object_get(json, "access_token"));
    if (!token) {
        ast_log(LOG_ERROR, "Could not find Google OAuth 2.0 access_token in: '%s'\n",
            buf);
    }
    token = ast_strdup(token);
    ast_json_unref(json);
    return token;
}
 
/*!
 * \internal
 * \brief Set pjsip registration context with any authentication credentials that need to be
 * sent in the initial registration request
 *
 * \param regc The pjsip registration context
 * \param auth_vector The vector of configured authentication credentials
 */
static int set_outbound_initial_authentication_credentials(pjsip_regc *regc,
        const struct ast_sip_auth_vector *auth_vector)
{
    size_t auth_size = AST_VECTOR_SIZE(auth_vector);
    struct ast_sip_auth *auths[auth_size];
    const char *access_token;
    pjsip_cred_info auth_creds[1];
    pjsip_auth_clt_pref prefs;
    int res = 0;
    int idx;
 
    memset(auths, 0, sizeof(auths));
    if (ast_sip_retrieve_auths(auth_vector, auths)) {
        res = -1;
        goto cleanup;
    }
 
    for (idx = 0; idx < auth_size; ++idx) {
        switch (auths[idx]->type) {
        case AST_SIP_AUTH_TYPE_GOOGLE_OAUTH:
            pj_cstr(&auth_creds[0].username, auths[idx]->auth_user);
            pj_cstr(&auth_creds[0].scheme, "Bearer");
            pj_cstr(&auth_creds[0].realm, auths[idx]->realm);
            ast_debug(2, "Obtaining Google OAuth access token\n");
            access_token = fetch_google_access_token(auths[idx]);
            if (!access_token) {
                ast_log(LOG_WARNING, "Obtaining Google OAuth access token failed\n");
                access_token = auths[idx]->auth_pass;
                res = -1;
            }
            ast_debug(2, "Setting data to '%s'\n", access_token);
 
            pj_cstr(&auth_creds[0].data, access_token);
            auth_creds[0].data_type = PJSIP_CRED_DATA_PLAIN_PASSWD;
 
            pjsip_regc_set_credentials(regc, 1, auth_creds);
 
            /* for oauth, send auth without waiting for unauthorized response */
            prefs.initial_auth = PJ_TRUE;
            pj_cstr(&prefs.algorithm, "oauth");
            pjsip_regc_set_prefs(regc, &prefs);
 
            if (access_token != auths[idx]->auth_pass) {
                ast_free((char *) access_token);
            }
            break;
        default:
            /* other cases handled after receiving auth rejection */
            break;
        }
    }
 
cleanup:
    ast_sip_cleanup_auths(auths, auth_size);
    return res;
}
 
/*! \brief Helper function that allocates a pjsip registration client and configures it */
static int sip_outbound_registration_regc_alloc(void *data)
{
    struct sip_outbound_registration_state *state = data;
    RAII_VAR(struct sip_outbound_registration *, registration,
         ao2_bump(state->registration), ao2_cleanup);
    pj_pool_t *pool;
    pj_str_t tmp;
    pjsip_uri *uri;
    pj_str_t server_uri, client_uri, contact_uri;
    pjsip_tpselector selector = { .type = PJSIP_TPSELECTOR_NONE, };
 
    pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(), "URI Validation", 256, 256);
    if (!pool) {
        ast_log(LOG_ERROR, "Could not create pool for URI validation on outbound registration '%s'\n",
            ast_sorcery_object_get_id(registration));
        return -1;
    }
 
    pj_strdup2_with_null(pool, &tmp, registration->server_uri);
    uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0);
    if (!uri) {
        ast_log(LOG_ERROR, "Invalid server URI '%s' specified on outbound registration '%s'\n",
            registration->server_uri, ast_sorcery_object_get_id(registration));
        pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
        return -1;
    }
 
    pj_strdup2_with_null(pool, &tmp, registration->client_uri);
    uri = pjsip_parse_uri(pool, tmp.ptr, tmp.slen, 0);
    if (!uri) {
        ast_log(LOG_ERROR, "Invalid client URI '%s' specified on outbound registration '%s'\n",
            registration->client_uri, ast_sorcery_object_get_id(registration));
        pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
        return -1;
    }
 
    pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
 
    ast_assert(state->client_state->client == NULL);
    if (pjsip_regc_create(ast_sip_get_pjsip_endpoint(), state->client_state,
            sip_outbound_registration_response_cb,
            &state->client_state->client) != PJ_SUCCESS) {
        return -1;
    }
 
    ast_sip_set_tpselector_from_transport_name(registration->transport, &selector);
    pjsip_regc_set_transport(state->client_state->client, &selector);
 
    if (!ast_strlen_zero(registration->outbound_proxy)) {
        pjsip_route_hdr route_set, *route;
        static const pj_str_t ROUTE_HNAME = { "Route", 5 };
        pj_str_t tmp;
 
        pj_list_init(&route_set);
 
        pj_strdup2_with_null(pjsip_regc_get_pool(state->client_state->client), &tmp,
            registration->outbound_proxy);
        route = pjsip_parse_hdr(pjsip_regc_get_pool(state->client_state->client),
            &ROUTE_HNAME, tmp.ptr, tmp.slen, NULL);
        if (!route) {
            ast_sip_tpselector_unref(&selector);
            return -1;
        }
        pj_list_insert_nodes_before(&route_set, route);
 
        pjsip_regc_set_route_set(state->client_state->client, &route_set);
    }
 
    if (state->registration->line) {
        ast_generate_random_string(state->client_state->line, sizeof(state->client_state->line));
    }
 
    pj_cstr(&server_uri, registration->server_uri);
 
    if (sip_dialog_create_contact(pjsip_regc_get_pool(state->client_state->client),
        &contact_uri, S_OR(registration->contact_user, "s"), &server_uri, &selector,
        state->client_state->line, registration->contact_header_params)) {
        ast_sip_tpselector_unref(&selector);
        return -1;
    }
 
    ast_sip_tpselector_unref(&selector);
 
    pj_cstr(&client_uri, registration->client_uri);
    if (pjsip_regc_init(state->client_state->client, &server_uri, &client_uri,
        &client_uri, 1, &contact_uri, registration->expiration) != PJ_SUCCESS) {
        return -1;
    }
 
    return 0;
}
 
/*! \brief Helper function which performs a single registration */
static int sip_outbound_registration_perform(void *data)
{
    struct sip_outbound_registration_state *state = data;
    struct sip_outbound_registration *registration = ao2_bump(state->registration);
    size_t i;
    int max_delay;
 
    /* Just in case the client state is being reused for this registration, free the auth information */
    ast_sip_auth_vector_destroy(&state->client_state->outbound_auths);
    ast_sip_security_mechanisms_vector_destroy(&state->client_state->security_mechanisms);
    ast_sip_security_mechanisms_vector_destroy(&state->client_state->server_security_mechanisms);
 
    AST_VECTOR_INIT(&state->client_state->outbound_auths, AST_VECTOR_SIZE(&registration->outbound_auths));
    for (i = 0; i < AST_VECTOR_SIZE(&registration->outbound_auths); ++i) {
        char *name = ast_strdup(AST_VECTOR_GET(&registration->outbound_auths, i));
 
        if (name && AST_VECTOR_APPEND(&state->client_state->outbound_auths, name)) {
            ast_free(name);
        }
    }
    ast_sip_security_mechanisms_vector_copy(&state->client_state->security_mechanisms,
                                            &registration->security_mechanisms);
    state->client_state->retry_interval = registration->retry_interval;
    state->client_state->forbidden_retry_interval = registration->forbidden_retry_interval;
    state->client_state->fatal_retry_interval = registration->fatal_retry_interval;
    state->client_state->max_retries = registration->max_retries;
    state->client_state->retries = 0;
    state->client_state->support_path = registration->support_path;
    state->client_state->support_outbound = registration->support_outbound;
    state->client_state->security_negotiation = registration->security_negotiation;
    state->client_state->auth_rejection_permanent = registration->auth_rejection_permanent;
    max_delay = registration->max_random_initial_delay;
 
    pjsip_regc_update_expires(state->client_state->client, registration->expiration);
 
    /* n mod 0 is undefined, so don't let that happen */
    schedule_registration(state->client_state, (max_delay ? ast_random() % max_delay : 0) + 1);
 
    ao2_ref(registration, -1);
    ao2_ref(state, -1);
    return 0;
}
 
/*! \brief Apply function which finds or allocates a state structure */
static int sip_outbound_registration_apply(const struct ast_sorcery *sorcery, void *obj)
{
    RAII_VAR(struct ao2_container *, states, ao2_global_obj_ref(current_states), ao2_cleanup);
    RAII_VAR(struct sip_outbound_registration_state *, state, NULL, ao2_cleanup);
    RAII_VAR(struct sip_outbound_registration_state *, new_state, NULL, ao2_cleanup);
    struct sip_outbound_registration *applied = obj;
 
    if (!states) {
        /* Global container has gone.  Likely shutting down. */
        return -1;
    }
    state = ao2_find(states, ast_sorcery_object_get_id(applied), OBJ_SEARCH_KEY);
 
    ast_debug(4, "Applying configuration to outbound registration '%s'\n", ast_sorcery_object_get_id(applied));
 
    if (ast_strlen_zero(applied->server_uri)) {
        ast_log(LOG_ERROR, "No server URI specified on outbound registration '%s'\n",
            ast_sorcery_object_get_id(applied));
        return -1;
    } else if (ast_sip_validate_uri_length(applied->server_uri)) {
            ast_log(LOG_ERROR, "Server URI or hostname length exceeds pjproject limit or is not a sip(s) uri: '%s'\n",
                ast_sorcery_object_get_id(applied));
            return -1;
    } else if (ast_strlen_zero(applied->client_uri)) {
        ast_log(LOG_ERROR, "No client URI specified on outbound registration '%s'\n",
            ast_sorcery_object_get_id(applied));
        return -1;
    } else if (ast_sip_validate_uri_length(applied->client_uri)) {
            ast_log(LOG_ERROR, "Client URI or hostname length exceeds pjproject limit or is not a sip(s) uri: '%s'\n",
                ast_sorcery_object_get_id(applied));
            return -1;
    } else if (applied->line && ast_strlen_zero(applied->endpoint)) {
        ast_log(LOG_ERROR, "Line support has been enabled on outbound registration '%s' without providing an endpoint\n",
            ast_sorcery_object_get_id(applied));
        return -1;
    } else if (!ast_strlen_zero(applied->endpoint) && !applied->line) {
        ast_log(LOG_ERROR, "An endpoint has been specified on outbound registration '%s' without enabling line support\n",
            ast_sorcery_object_get_id(applied));
        return -1;
    }
 
    if (state && can_reuse_registration(state->registration, applied)) {
        ast_debug(4,
            "No change between old configuration and new configuration on outbound registration '%s'. Using previous state\n",
            ast_sorcery_object_get_id(applied));
 
        /*
         * This is OK to replace without relinking the state in the
         * current_states container since state->registration and
         * applied have the same key.
         */
        ao2_lock(states);
        ao2_replace(state->registration, applied);
        ao2_unlock(states);
        return 0;
    }
 
    if (!(new_state = sip_outbound_registration_state_alloc(applied))) {
        return -1;
    }
 
    if (ast_sip_push_task_wait_serializer(new_state->client_state->serializer,
        sip_outbound_registration_regc_alloc, new_state)) {
        return -1;
    }
 
    if (ast_sip_push_task(new_state->client_state->serializer,
                  sip_outbound_registration_perform, ao2_bump(new_state))) {
        ast_log(LOG_ERROR, "Failed to perform outbound registration on '%s'\n",
            ast_sorcery_object_get_id(new_state->registration));
        ao2_ref(new_state, -1);
        return -1;
    }
 
    ao2_lock(states);
    if (state) {
        ao2_unlink(states, state);
    }
    ao2_link(states, new_state);
    ao2_unlock(states);
 
    return 0;
}
 
static int security_mechanism_to_str(const void *obj, const intptr_t *args, char **buf)
{
    const struct sip_outbound_registration *registration = obj;
 
    return ast_sip_security_mechanisms_to_str(&registration->security_mechanisms, 0, buf);
}
 
static const char *security_negotiation_map[] = {
    [AST_SIP_SECURITY_NEG_NONE] = "no",
    [AST_SIP_SECURITY_NEG_MEDIASEC] = "mediasec",
};
 
static int security_negotiation_to_str(const void *obj, const intptr_t *args, char **buf)
{
    const struct sip_outbound_registration *registration = obj;
    if (ARRAY_IN_BOUNDS(registration->security_negotiation, security_negotiation_map)) {
        *buf = ast_strdup(security_negotiation_map[registration->security_negotiation]);
    }
    return 0;
}
 
static int security_mechanisms_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
    struct sip_outbound_registration *registration = obj;
 
    return ast_sip_security_mechanism_vector_init(&registration->security_mechanisms, var->value);
}
 
static int security_negotiation_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
    struct sip_outbound_registration *registration = obj;
 
    return ast_sip_set_security_negotiation(&registration->security_negotiation, var->value);
}
 
static int outbound_auth_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
{
    struct sip_outbound_registration *registration = obj;
 
    return ast_sip_auth_vector_init(&registration->outbound_auths, var->value);
}
 
static int outbound_auths_to_str(const void *obj, const intptr_t *args, char **buf)
{
    const struct sip_outbound_registration *registration = obj;
 
    return ast_sip_auths_to_str(&registration->outbound_auths, buf);
}
 
static int outbound_auths_to_var_list(const void *obj, struct ast_variable **fields)
{
    const struct sip_outbound_registration *registration = obj;
    int i;
    struct ast_variable *head = NULL;
 
    for (i = 0; i < AST_VECTOR_SIZE(&registration->outbound_auths) ; i++) {
        ast_variable_list_append(&head, ast_variable_new("outbound_auth",
            AST_VECTOR_GET(&registration->outbound_auths, i), ""));
    }
 
    if (head) {
        *fields = head;
    }
 
    return 0;
}
 
static int unregister_task(void *obj)
{
    struct sip_outbound_registration_state *state = obj;
    struct pjsip_regc *client = state->client_state->client;
    pjsip_tx_data *tdata;
    pjsip_regc_info info;
 
    pjsip_regc_get_info(client, &info);
    ast_debug(1, "Unregistering contacts with server '%s' from client '%s'\n",
        state->registration->server_uri, state->registration->client_uri);
 
    cancel_registration(state->client_state);
 
    if (pjsip_regc_unregister(client, &tdata) == PJ_SUCCESS
        && add_configured_supported_headers(state->client_state, tdata)) {
        registration_client_send(state->client_state, tdata);
    }
 
    ao2_ref(state, -1);
    return 0;
}
 
static int queue_unregister(struct sip_outbound_registration_state *state)
{
    ao2_ref(state, +1);
    if (ast_sip_push_task(state->client_state->serializer, unregister_task, state)) {
        ao2_ref(state, -1);
        return -1;
    }
 
    return 0;
}
 
static int queue_register(struct sip_outbound_registration_state *state)
{
    ao2_ref(state, +1);
    if (ast_sip_push_task(state->client_state->serializer, sip_outbound_registration_perform, state)) {
        ao2_ref(state, -1);
        return -1;
    }
 
    return 0;
}
 
static void unregister_all(void)
{
    struct ao2_container *states;
 
    states = ao2_global_obj_ref(current_states);
    if (!states) {
        return;
    }
 
    /* Clean out all the states and let sorcery handle recreating the registrations */
    ao2_callback(states, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL);
    ao2_ref(states, -1);
}
 
static void reregister_all(void)
{
    unregister_all();
    ast_sorcery_load_object(ast_sip_get_sorcery(), "registration");
}
 
static char *cli_complete_registration(const char *line, const char *word,
                       int pos, int state)
{
    char *result = NULL;
    int wordlen;
    int which = 0;
    struct sip_outbound_registration *registration;
    struct ao2_container *registrations;
    struct ao2_iterator i;
 
    if (pos != 3) {
        return NULL;
    }
 
    wordlen = strlen(word);
    if (wordlen == 0 && ++which > state) {
        return ast_strdup("*all");
    }
 
    registrations = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "registration",
        AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
    if (!registrations) {
        return NULL;
    }
 
    i = ao2_iterator_init(registrations, 0);
    while ((registration = ao2_iterator_next(&i))) {
        const char *name = ast_sorcery_object_get_id(registration);
 
        if (!strncasecmp(word, name, wordlen) && ++which > state) {
            result = ast_strdup(name);
        }
 
        ao2_ref(registration, -1);
        if (result) {
            break;
        }
    }
    ao2_iterator_destroy(&i);
 
    ao2_ref(registrations, -1);
    return result;
}
 
static char *cli_unregister(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct sip_outbound_registration_state *state;
    const char *registration_name;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "pjsip send unregister";
        e->usage =
            "Usage: pjsip send unregister <registration> | *all\n"
            "       Unregisters the specified (or all) outbound registration(s) "
            "and stops future registration attempts.\n";
        return NULL;
    case CLI_GENERATE:
        return cli_complete_registration(a->line, a->word, a->pos, a->n);
    }
 
    if (a->argc != 4) {
        return CLI_SHOWUSAGE;
    }
 
    registration_name = a->argv[3];
 
    if (strcmp(registration_name, "*all") == 0) {
        unregister_all();
        ast_cli(a->fd, "Unregister all queued\n");
        return CLI_SUCCESS;
    }
 
    state = get_state(registration_name);
    if (!state) {
        ast_cli(a->fd, "Unable to retrieve registration %s\n", registration_name);
        return CLI_FAILURE;
    }
 
    if (queue_unregister(state)) {
        ast_cli(a->fd, "Failed to queue unregistration\n");
    }
 
    ao2_ref(state, -1);
    return CLI_SUCCESS;
}
 
static char *cli_register(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    struct sip_outbound_registration_state *state;
    const char *registration_name;
 
    switch (cmd) {
    case CLI_INIT:
        e->command = "pjsip send register";
        e->usage =
            "Usage: pjsip send register <registration> | *all \n"
            "       Unregisters the specified (or all) outbound "
            "registration(s) then starts registration(s) and schedules re-registrations.\n";
        return NULL;
    case CLI_GENERATE:
        return cli_complete_registration(a->line, a->word, a->pos, a->n);
    }
 
    if (a->argc != 4) {
        return CLI_SHOWUSAGE;
    }
 
    registration_name = a->argv[3];
 
    if (strcmp(registration_name, "*all") == 0) {
        reregister_all();
        ast_cli(a->fd, "Re-register all queued\n");
        return CLI_SUCCESS;
    }
 
    state = get_state(registration_name);
    if (!state) {
        ast_cli(a->fd, "Unable to retrieve registration %s\n", registration_name);
        return CLI_FAILURE;
    }
 
    /* We need to serialize the unregister and register so they need
     * to be queued as separate tasks.
     */
    if (queue_unregister(state)) {
        ast_cli(a->fd, "Failed to queue unregistration\n");
    } else if (queue_register(state)) {
        ast_cli(a->fd, "Failed to queue registration\n");
    }
 
    ao2_ref(state, -1);
    return CLI_SUCCESS;
}
 
static int ami_unregister(struct mansession *s, const struct message *m)
{
    const char *registration_name = astman_get_header(m, "Registration");
    struct sip_outbound_registration_state *state;
 
    if (ast_strlen_zero(registration_name)) {
        astman_send_error(s, m, "Registration parameter missing.");
        return 0;
    }
 
    if (strcmp(registration_name, "*all") == 0) {
        unregister_all();
        astman_send_ack(s, m, "Unregistrations queued.");
        return 0;
    }
 
    state = get_state(registration_name);
    if (!state) {
        astman_send_error(s, m, "Unable to retrieve registration entry\n");
        return 0;
    }
 
    if (queue_unregister(state)) {
        astman_send_ack(s, m, "Failed to queue unregistration");
    } else {
        astman_send_ack(s, m, "Unregistration sent");
    }
 
    ao2_ref(state, -1);
    return 0;
}
 
static int ami_register(struct mansession *s, const struct message *m)
{
    const char *registration_name = astman_get_header(m, "Registration");
    struct sip_outbound_registration_state *state;
 
    if (ast_strlen_zero(registration_name)) {
        astman_send_error(s, m, "Registration parameter missing.");
        return 0;
    }
 
    if (strcmp(registration_name, "*all") == 0) {
        reregister_all();
        astman_send_ack(s, m, "Reregistrations queued.");
        return 0;
    }
 
    state = get_state(registration_name);
    if (!state) {
        astman_send_error(s, m, "Unable to retrieve registration entry\n");
        return 0;
    }
 
    /* We need to serialize the unregister and register so they need
     * to be queued as separate tasks.
     */
    if (queue_unregister(state)) {
        astman_send_ack(s, m, "Failed to queue unregistration");
    } else if (queue_register(state)) {
        astman_send_ack(s, m, "Failed to queue unregistration");
    } else {
        astman_send_ack(s, m, "Reregistration sent");
    }
 
    ao2_ref(state, -1);
    return 0;
}
 
struct sip_ami_outbound {
    struct ast_sip_ami *ami;
    int registered;
    int not_registered;
    struct sip_outbound_registration *registration;
};
 
static int ami_outbound_registration_task(void *obj)
{
    struct sip_ami_outbound *ami = obj;
    struct ast_str *buf;
    struct sip_outbound_registration_state *state;
 
    buf = ast_sip_create_ami_event("OutboundRegistrationDetail", ami->ami);
    if (!buf) {
        return -1;
    }
 
    ast_sip_sorcery_object_to_ami(ami->registration, &buf);
 
    if ((state = get_state(ast_sorcery_object_get_id(ami->registration)))) {
        pjsip_regc_info info;
 
        if (state->client_state->status == SIP_REGISTRATION_REGISTERED) {
            ++ami->registered;
        } else {
            ++ami->not_registered;
        }
 
        ast_str_append(&buf, 0, "Status: %s\r\n",
            sip_outbound_registration_status_str(state->client_state->status));
 
        pjsip_regc_get_info(state->client_state->client, &info);
        ast_str_append(&buf, 0, "NextReg: %d\r\n", info.next_reg);
        ao2_ref(state, -1);
    }
 
    astman_append(ami->ami->s, "%s\r\n", ast_str_buffer(buf));
    ast_free(buf);
 
    return ast_sip_format_auths_ami(&ami->registration->outbound_auths, ami->ami);
}
 
static int ami_outbound_registration_detail(void *obj, void *arg, int flags)
{
    struct sip_ami_outbound *ami = arg;
 
    ami->registration = obj;
    return ast_sip_push_task_wait_servant(NULL, ami_outbound_registration_task, ami);
}
 
static int ami_show_outbound_registrations(struct mansession *s,
                       const struct message *m)
{
    struct ast_sip_ami ami = { .s = s, .m = m, .action_id = astman_get_header(m, "ActionID"), };
    struct sip_ami_outbound ami_outbound = { .ami = &ami };
    struct ao2_container *regs;
 
    regs = get_registrations();
    if (!regs) {
        astman_send_error(s, m, "Unable to retrieve "
                  "outbound registrations\n");
        return -1;
    }
 
    astman_send_listack(s, m, "Following are Events for each Outbound registration",
        "start");
 
    ao2_callback(regs, OBJ_NODATA, ami_outbound_registration_detail, &ami_outbound);
 
    astman_send_list_complete_start(s, m, "OutboundRegistrationDetailComplete",
        ami_outbound.registered + ami_outbound.not_registered);
    astman_append(s,
        "Registered: %d\r\n"
        "NotRegistered: %d\r\n",
        ami_outbound.registered,
        ami_outbound.not_registered);
    astman_send_list_complete_end(s);
 
    ao2_ref(regs, -1);
    return 0;
}
 
static struct ao2_container *cli_get_container(const char *regex)
{
    RAII_VAR(struct ao2_container *, container, NULL, ao2_cleanup);
    struct ao2_container *s_container;
 
    container = ast_sorcery_retrieve_by_regex(ast_sip_get_sorcery(), "registration", regex);
    if (!container) {
        return NULL;
    }
 
    s_container = ao2_container_alloc_list(AO2_ALLOC_OPT_LOCK_NOLOCK, 0,
        ast_sorcery_object_id_sort, ast_sorcery_object_id_compare);
    if (!s_container) {
        return NULL;
    }
 
    if (ao2_container_dup(s_container, container, 0)) {
        ao2_ref(s_container, -1);
        return NULL;
    }
 
    return s_container;
}
 
static int cli_iterator(void *container, ao2_callback_fn callback, void *args)
{
    ao2_callback(container, OBJ_NODATA, callback, args);
 
    return 0;
}
 
static void *cli_retrieve_by_id(const char *id)
{
    struct ao2_container *states;
    void *obj = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration", id);
 
    if (!obj) {
        /* if the object no longer exists then remove its state  */
        states = ao2_global_obj_ref(current_states);
        if (states) {
            ao2_find(states, id, OBJ_SEARCH_KEY | OBJ_UNLINK | OBJ_NODATA);
            ao2_ref(states, -1);
        }
    }
 
    return obj;
}
 
static int cli_print_header(void *obj, void *arg, int flags)
{
    struct ast_sip_cli_context *context = arg;
 
    ast_assert(context->output_buffer != NULL);
 
    ast_str_append(&context->output_buffer, 0,
        " <Registration/ServerURI..............................>  <Auth....................>  <Status.......>\n");
 
    return 0;
}
 
static int cli_print_body(void *obj, void *arg, int flags)
{
    struct sip_outbound_registration *registration = obj;
    struct ast_sip_cli_context *context = arg;
    const char *id = ast_sorcery_object_get_id(registration);
    struct sip_outbound_registration_state *state = get_state(id);
    int expsecs;
#define REGISTRATION_URI_FIELD_LEN  53
 
    ast_assert(context->output_buffer != NULL);
    expsecs = state ? state->client_state->registration_expires - ((int) time(NULL)) : 0;
 
    ast_str_append(&context->output_buffer, 0, " %-s/%-*.*s  %-26s  %-16s %s%d%s\n",
        id,
        (int) (REGISTRATION_URI_FIELD_LEN - strlen(id)),
        (int) (REGISTRATION_URI_FIELD_LEN - strlen(id)),
        registration->server_uri,
        AST_VECTOR_SIZE(&registration->outbound_auths)
            ? AST_VECTOR_GET(&registration->outbound_auths, 0)
            : "n/a",
        (state ? sip_outbound_registration_status_str(state->client_state->status) : "Unregistered"),
        state ? " (exp. " : "", abs(expsecs), state ? (expsecs < 0 ? "s ago)" : "s)") : "");
    ao2_cleanup(state);
 
    if (context->show_details
        || (context->show_details_only_level_0 && context->indent_level == 0)) {
        ast_str_append(&context->output_buffer, 0, "\n");
        ast_sip_cli_print_sorcery_objectset(registration, context, 0);
    }
 
    return 0;
}
 
/*
 * A function pointer to callback needs to be within the
 * module in order to avoid problems with an undefined
 * symbol when the module is loaded.
 */
static char *my_cli_traverse_objects(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    return ast_sip_cli_traverse_objects(e, cmd, a);
}
 
static struct ast_cli_entry cli_outbound_registration[] = {
    AST_CLI_DEFINE(cli_unregister, "Unregisters outbound registration target"),
    AST_CLI_DEFINE(cli_register, "Registers an outbound registration target"),
    AST_CLI_DEFINE(my_cli_traverse_objects, "List PJSIP Registrations",
        .command = "pjsip list registrations",
        .usage = "Usage: pjsip list registrations [ like <pattern> ]\n"
                "       List the configured PJSIP Registrations\n"
                "       Optional regular expression pattern is used to filter the list.\n"),
    AST_CLI_DEFINE(my_cli_traverse_objects, "Show PJSIP Registrations",
        .command = "pjsip show registrations",
        .usage = "Usage: pjsip show registrations [ like <pattern> ]\n"
                "       Show the configured PJSIP Registrations\n"
                "       Optional regular expression pattern is used to filter the list.\n"),
    AST_CLI_DEFINE(my_cli_traverse_objects, "Show PJSIP Registration",
        .command = "pjsip show registration",
        .usage = "Usage: pjsip show registration <id>\n"
                 "       Show the configured PJSIP Registration\n"),
};
 
static struct ast_sip_cli_formatter_entry *cli_formatter;
 
static void auth_observer(const char *type)
{
    struct sip_outbound_registration *registration;
    struct sip_outbound_registration_state *state;
    struct ao2_container *regs;
    const char *registration_id;
    struct ao2_iterator i;
 
    ast_debug(4, "Auths updated. Checking for any outbound registrations that are in permanent rejected state so they can be retried\n");
 
    regs = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "registration",
        AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
    if (!regs || ao2_container_count(regs) == 0) {
        ao2_cleanup(regs);
        return;
    }
 
    i = ao2_iterator_init(regs, 0);
    for (; (registration = ao2_iterator_next(&i)); ao2_ref(registration, -1)) {
        registration_id = ast_sorcery_object_get_id(registration);
        state = get_state(registration_id);
        if (state && state->client_state->status == SIP_REGISTRATION_REJECTED_PERMANENT) {
            ast_debug(4, "Trying outbound registration '%s' again\n", registration_id);
 
            if (ast_sip_push_task(state->client_state->serializer,
                          sip_outbound_registration_perform, ao2_bump(state))) {
                ast_log(LOG_ERROR, "Failed to perform outbound registration on '%s'\n", registration_id);
                ao2_ref(state, -1);
            }
        }
        ao2_cleanup(state);
    }
    ao2_iterator_destroy(&i);
    ao2_cleanup(regs);
}
 
static const struct ast_sorcery_observer observer_callbacks_auth = {
    .loaded = auth_observer,
};
 
static int check_state(void *obj, void *arg, int flags)
{
    struct sip_outbound_registration_state *state = obj;
    struct sip_outbound_registration *registration;
 
    registration = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "registration",
        ast_sorcery_object_get_id(state->registration));
    if (!registration) {
        /* This is a dead registration */
        return CMP_MATCH;
    }
 
    ao2_ref(registration, -1);
    return 0;
}
 
/*!
 * \internal
 * \brief Observer to purge dead registration states.
 *
 * \param name Module name owning the sorcery instance.
 * \param sorcery Instance being observed.
 * \param object_type Name of object being observed.
 * \param reloaded Non-zero if the object is being reloaded.
 */
static void registration_loaded_observer(const char *name, const struct ast_sorcery *sorcery, const char *object_type, int reloaded)
{
    struct ao2_container *states;
 
    if (strcmp(object_type, "registration")) {
        /* Not interested */
        return;
    }
 
    states = ao2_global_obj_ref(current_states);
    if (!states) {
        /* Global container has gone.  Likely shutting down. */
        return;
    }
 
    /*
     * Refresh the current configured registrations. We don't need to hold
     * onto the objects, as the apply handler will cause their states to
     * be created appropriately.
     */
    ao2_cleanup(get_registrations());
 
    /* Now to purge dead registrations. */
    ao2_callback(states, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, check_state, NULL);
    ao2_ref(states, -1);
}
 
static const struct ast_sorcery_instance_observer observer_callbacks_registrations = {
    .object_type_loaded = registration_loaded_observer,
};
 
static void registration_deleted_observer(const void *obj)
{
    const struct sip_outbound_registration *registration = obj;
    struct ao2_container *states;
 
    states = ao2_global_obj_ref(current_states);
    if (!states) {
        /* Global container has gone.  Likely shutting down. */
        return;
    }
 
    ao2_find(states, ast_sorcery_object_get_id(registration), OBJ_UNLINK | OBJ_NODATA | OBJ_SEARCH_KEY);
 
    ao2_ref(states, -1);
}
 
static const struct ast_sorcery_observer registration_observer = {
    .deleted = registration_deleted_observer,
};
 
static void network_change_stasis_cb(void *data, struct stasis_subscription *sub, struct stasis_message *message)
{
    /* This callback is only concerned with network change messages from the system topic. */
    if (stasis_message_type(message) != ast_network_change_type()) {
        return;
    }
    ast_debug(3, "Received network change event\n");
 
    reregister_all();
}
 
static int unload_module(void)
{
    int remaining;
 
    network_change_sub = stasis_unsubscribe_and_join(network_change_sub);
 
    ast_manager_unregister("PJSIPShowRegistrationsOutbound");
    ast_manager_unregister("PJSIPUnregister");
    ast_manager_unregister("PJSIPRegister");
 
    ast_cli_unregister_multiple(cli_outbound_registration, ARRAY_LEN(cli_outbound_registration));
    ast_sip_unregister_cli_formatter(cli_formatter);
    cli_formatter = NULL;
 
    ast_sip_unregister_endpoint_identifier(&line_identifier);
 
    ast_sorcery_observer_remove(ast_sip_get_sorcery(), "auth", &observer_callbacks_auth);
    ast_sorcery_instance_observer_remove(ast_sip_get_sorcery(), &observer_callbacks_registrations);
 
    ast_sorcery_object_unregister(ast_sip_get_sorcery(), "registration");
 
    ao2_global_obj_release(current_states);
 
    ast_sip_transport_monitor_unregister_all(registration_transport_shutdown_cb, NULL, NULL);
 
    /* Wait for registration serializers to get destroyed. */
    ast_debug(2, "Waiting for registration transactions to complete for unload.\n");
    remaining = ast_serializer_shutdown_group_join(shutdown_group, MAX_UNLOAD_TIMEOUT_TIME);
    if (remaining) {
        /*
         * NOTE: We probably have a sip_outbound_registration_client_state
         * ref leak if the remaining count cannot reach zero after a few
         * minutes of trying to unload.
         */
        ast_log(LOG_WARNING, "Unload incomplete.  Could not stop %d outbound registrations.  Try again later.\n",
            remaining);
        return -1;
    }
 
    ast_debug(2, "Successful shutdown.\n");
 
    ao2_cleanup(shutdown_group);
    shutdown_group = NULL;
 
    return 0;
}
 
static int load_module(void)
{
    struct ao2_container *new_states;
 
    shutdown_group = ast_serializer_shutdown_group_alloc();
    if (!shutdown_group) {
        return AST_MODULE_LOAD_DECLINE;
    }
 
    /* Create outbound registration states container. */
    new_states = ao2_container_alloc_hash(AO2_ALLOC_OPT_LOCK_MUTEX, 0,
        DEFAULT_STATE_BUCKETS, registration_state_hash, NULL, registration_state_cmp);
    if (!new_states) {
        ast_log(LOG_ERROR, "Unable to allocate registration states container\n");
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
    ao2_global_obj_replace_unref(current_states, new_states);
    ao2_ref(new_states, -1);
 
    /*
     * Register sorcery object descriptions.
     */
    ast_sorcery_apply_config(ast_sip_get_sorcery(), "res_pjsip_outbound_registration");
    ast_sorcery_apply_default(ast_sip_get_sorcery(), "registration", "config", "pjsip.conf,criteria=type=registration");
 
    if (ast_sorcery_object_register(ast_sip_get_sorcery(), "registration", sip_outbound_registration_alloc, NULL, sip_outbound_registration_apply)) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "type", "", OPT_NOOP_T, 0, 0);
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "server_uri", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, server_uri));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "client_uri", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, client_uri));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "contact_user", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, contact_user));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "contact_header_params", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, contact_header_params));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "transport", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, transport));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "outbound_proxy", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, outbound_proxy));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "expiration", "3600", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, expiration));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "max_random_initial_delay", "10", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, max_random_initial_delay));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "retry_interval", "60", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, retry_interval));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "forbidden_retry_interval", "0", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, forbidden_retry_interval));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "fatal_retry_interval", "0", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, fatal_retry_interval));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "max_retries", "10", OPT_UINT_T, 0, FLDSET(struct sip_outbound_registration, max_retries));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "auth_rejection_permanent", "yes", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, auth_rejection_permanent));
    ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "registration", "outbound_auth", "", outbound_auth_handler, outbound_auths_to_str, outbound_auths_to_var_list, 0, 0);
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "support_path", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, support_path));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "support_outbound", "no", OPT_YESNO_T, 1, FLDSET(struct sip_outbound_registration, support_outbound));
    ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "registration", "security_negotiation", "no", security_negotiation_handler, security_negotiation_to_str, NULL, 0, 0);
    ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "registration", "security_mechanisms", "", security_mechanisms_handler, security_mechanism_to_str, NULL, 0, 0);
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "line", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, line));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "endpoint", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, endpoint));
    ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "user_agent", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, user_agent));
 
    /*
     * Register sorcery observers.
     */
    if (ast_sorcery_instance_observer_add(ast_sip_get_sorcery(),
        &observer_callbacks_registrations)
        || ast_sorcery_observer_add(ast_sip_get_sorcery(), "auth",
            &observer_callbacks_auth)
        || ast_sorcery_observer_add(ast_sip_get_sorcery(), "registration",
            &registration_observer)) {
        ast_log(LOG_ERROR, "Unable to register observers.\n");
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    /* Register how this module identifies endpoints. */
    ast_sip_register_endpoint_identifier(&line_identifier);
 
    /* Register CLI commands. */
    cli_formatter = ao2_alloc(sizeof(struct ast_sip_cli_formatter_entry), NULL);
    if (!cli_formatter) {
        ast_log(LOG_ERROR, "Unable to allocate memory for cli formatter\n");
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
    cli_formatter->name = "registration";
    cli_formatter->print_header = cli_print_header;
    cli_formatter->print_body = cli_print_body;
    cli_formatter->get_container = cli_get_container;
    cli_formatter->iterate = cli_iterator;
    cli_formatter->get_id = ast_sorcery_object_get_id;
    cli_formatter->retrieve_by_id = cli_retrieve_by_id;
    ast_sip_register_cli_formatter(cli_formatter);
    ast_cli_register_multiple(cli_outbound_registration, ARRAY_LEN(cli_outbound_registration));
 
    /* Register AMI actions. */
    ast_manager_register_xml("PJSIPUnregister", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_unregister);
    ast_manager_register_xml("PJSIPRegister", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_register);
    ast_manager_register_xml("PJSIPShowRegistrationsOutbound", EVENT_FLAG_SYSTEM | EVENT_FLAG_REPORTING, ami_show_outbound_registrations);
 
    /* Clear any previous statsd gauges in case we weren't shutdown cleanly */
    ast_statsd_log("PJSIP.registrations.count", AST_STATSD_GAUGE, 0);
    ast_statsd_log("PJSIP.registrations.state.Registered", AST_STATSD_GAUGE, 0);
    ast_statsd_log("PJSIP.registrations.state.Unregistered", AST_STATSD_GAUGE, 0);
    ast_statsd_log("PJSIP.registrations.state.Rejected", AST_STATSD_GAUGE, 0);
 
    /* Load configuration objects */
    ast_sorcery_load_object(ast_sip_get_sorcery(), "registration");
 
    network_change_sub = stasis_subscribe(ast_system_topic(),
        network_change_stasis_cb, NULL);
    stasis_subscription_accept_message_type(network_change_sub, ast_network_change_type());
    stasis_subscription_set_filter(network_change_sub, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int reload_module(void)
{
    ast_sorcery_reload_object(ast_sip_get_sorcery(), "registration");
    return 0;
}
 
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Outbound Registration Support",
    .support_level = AST_MODULE_SUPPORT_CORE,
    .load = load_module,
    .reload = reload_module,
    .unload = unload_module,
    .load_pri = AST_MODPRI_APP_DEPEND,
    .requires = "res_pjsip",
    .optional_modules = "res_statsd",
);