channel_info.c File Reference

Channel-locked PJSIP information for CHANNEL() reads. More...

#include "asterisk.h"
#include <pjsip.h>
#include "asterisk/astobj2.h"
#include "asterisk/channel.h"
#include "asterisk/datastore.h"
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_session.h"
#include "asterisk/rtp_engine.h"
#include "include/channel_info.h"

Include dependency graph for channel_info.c:

Go to the source code of this file.

Functions
static void	channel_info_breakdown (void *data, struct ast_channel *old_chan, struct ast_channel *new_chan)
static void	channel_info_destroy (void *data)
static int	channel_info_incoming_request (struct ast_sip_session *session, struct pjsip_rx_data *rdata)
static void	channel_info_incoming_response (struct ast_sip_session *session, struct pjsip_rx_data *rdata)
static void	channel_info_outgoing_request (struct ast_sip_session *session, struct pjsip_tx_data *tdata)
static void	channel_info_outgoing_response (struct ast_sip_session *session, struct pjsip_tx_data *tdata)
static void	channel_info_update_locked (struct pjsip_channel_info *info, struct ast_sip_session *session)
static int	channel_info_update_task (void *data)
static int	copy_uri (struct pjsip_channel_uri *dest, pjsip_uri_context_e context, const void *uri, const char *type)
int	pjsip_channel_info_create (struct ast_channel *chan, struct ast_sip_session *session)
	Create channel-owned PJSIP information before channel publication.
struct pjsip_channel_info *	pjsip_channel_info_get (struct ast_channel *chan)
	Find the channel's information, or NULL if it has none.
void	pjsip_channel_info_register (void)
	Register the channel information session supplement.
void	pjsip_channel_info_schedule_update (struct ast_sip_session *session)
	Schedule a refresh from any thread without waiting for the serializer.
void	pjsip_channel_info_unregister (void)
	Unregister the channel information session supplement.
void	pjsip_channel_info_update (struct ast_sip_session *session)
	Refresh channel information under the channel lock.

Variables
static const struct ast_datastore_info	channel_info_datastore
static struct ast_sip_session_supplement	channel_info_supplement

Detailed Description

Channel-locked PJSIP information for CHANNEL() reads.

The channel datastore owns cached dialog URIs, the remote tag, signaling security, RTP instance references, and media security and hold flags. Readers and writers access the cache under the channel lock. A datastore lookup returns a borrowed pointer valid only while that lock is held.

Session serializer tasks refresh the cache through session->channel. SIP supplements refresh it during incoming message processing and queue refreshes for subsequent changes. Masquerades suspend the serializer while changing the channel association and move the datastore with the channel.

CHANNEL() reads use the cache for values that SIP and SDP processing can change without the channel lock. Stable identity and original request information are read directly from the session. Direct-media addresses are read under the channel lock. RTP APIs supply RTP addresses and statistics.

These reads do not wait for the session serializer or acquire the dialog lock while holding the channel lock to avoid a deadlock with masquerade processing.

Definition in file channel_info.c.

Function Documentation

channel_info_breakdown()

static void channel_info_breakdown ( void *  data, struct ast_channel *  old_chan, struct ast_channel *  new_chan  )

static

Definition at line 67 of file channel_info.c.

{
    struct pjsip_channel_info *info = data;
    struct ast_datastore *datastore = info->datastore;
 
    /*
     * Core calls breakdown on the destination's old datastores before moving
     * the source's datastores over. Both channels are locked. The moved
     * datastore needs no fixup because it contains no channel pointer.
     */
    if (!ast_channel_datastore_remove(new_chan, datastore)) {
        ast_datastore_free(datastore);
    }
}

References ast_channel_datastore_remove(), ast_datastore_free(), and ast_datastore::info.

channel_info_destroy()

static void channel_info_destroy ( void *  data )

static

Definition at line 57 of file channel_info.c.

{
    struct pjsip_channel_info *info = data;
 
    ast_free(info->remote_tag);
    ao2_cleanup(info->audio_rtp);
    ao2_cleanup(info->video_rtp);
    ast_free(info);
}

References ao2_cleanup, and ast_free.

channel_info_incoming_request()

static int channel_info_incoming_request ( struct ast_sip_session *  session, struct pjsip_rx_data *  rdata  )

static

Definition at line 252 of file channel_info.c.

{
    pjsip_channel_info_update(session);
    pjsip_channel_info_schedule_update(session);
    return 0;
}

References pjsip_channel_info_schedule_update(), pjsip_channel_info_update(), and session.

channel_info_incoming_response()

static void channel_info_incoming_response ( struct ast_sip_session *  session, struct pjsip_rx_data *  rdata  )

static

Definition at line 260 of file channel_info.c.

{
    pjsip_channel_info_update(session);
    pjsip_channel_info_schedule_update(session);
}

References pjsip_channel_info_schedule_update(), pjsip_channel_info_update(), and session.

channel_info_outgoing_request()

static void channel_info_outgoing_request ( struct ast_sip_session *  session, struct pjsip_tx_data *  tdata  )

static

Definition at line 267 of file channel_info.c.

{
    pjsip_channel_info_schedule_update(session);
}

References pjsip_channel_info_schedule_update(), and session.

channel_info_outgoing_response()

static void channel_info_outgoing_response ( struct ast_sip_session *  session, struct pjsip_tx_data *  tdata  )

static

Definition at line 273 of file channel_info.c.

{
    pjsip_channel_info_schedule_update(session);
}

References pjsip_channel_info_schedule_update(), and session.

channel_info_update_locked()

static void channel_info_update_locked ( struct pjsip_channel_info *  info, struct ast_sip_session *  session  )

static

Definition at line 122 of file channel_info.c.

{
    pjsip_dialog *dlg = session->inv_session ? session->inv_session->dlg : NULL;
    struct ast_sip_session_media *media;
 
    if (dlg) {
        int target_changed;
        const pj_str_t *tag = &dlg->remote.info->tag;
 
        target_changed = copy_uri(&info->target_uri, PJSIP_URI_IN_REQ_URI,
            dlg->target, "target_uri");
        copy_uri(&info->local_uri, PJSIP_URI_IN_FROMTO_HDR,
            dlg->local.info->uri, "local_uri");
        copy_uri(&info->remote_uri, PJSIP_URI_IN_FROMTO_HDR,
            dlg->remote.info->uri, "remote_uri");
        /* PJSIP_MAX_TAG_LEN describes generated tags, not a received-tag limit. */
        if (!info->remote_tag || strlen(info->remote_tag) != tag->slen
            || (tag->slen && memcmp(info->remote_tag, tag->ptr, tag->slen))) {
            char *copy = ast_strndup(tag->slen ? tag->ptr : "", tag->slen);
 
            ast_free(info->remote_tag);
            info->remote_tag = copy;
        }
#ifdef HAVE_PJSIP_GET_DEST_INFO
        if (target_changed || info->target_uri.length < 0 || info->secure < 0) {
            pjsip_host_info dest;
            pj_pool_t *pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(),
                "channel-info", 128, 128);
 
            info->secure = -1;
            if (pool) {
                if (pjsip_get_dest_info(dlg->target, NULL, pool, &dest) == PJ_SUCCESS) {
                    info->secure = !!(dest.flag & PJSIP_TRANSPORT_SECURE);
                }
                pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), pool);
            }
        }
#else
        ast_log(LOG_WARNING, "Asterisk has been built against a version of pjproject which does not have the required functionality to support the 'secure' argument. Please upgrade to version 2.3 or later.\n");
        (void) target_changed;
#endif
    } else {
        copy_uri(&info->target_uri, PJSIP_URI_IN_REQ_URI, NULL, "target_uri");
        copy_uri(&info->local_uri, PJSIP_URI_IN_FROMTO_HDR, NULL, "local_uri");
        copy_uri(&info->remote_uri, PJSIP_URI_IN_FROMTO_HDR, NULL, "remote_uri");
        ast_free(info->remote_tag);
        info->remote_tag = NULL;
        info->secure = -1;
    }
 
    media = session->active_media_state
        ? session->active_media_state->default_session[AST_MEDIA_TYPE_AUDIO] : NULL;
    ao2_replace(info->audio_rtp, media ? media->rtp : NULL);
    info->audio_secure = media && media->srtp
        && ast_test_flag(media->srtp, AST_SRTP_CRYPTO_OFFER_OK);
    info->audio_held = media && media->remotely_held;
    media = session->active_media_state
        ? session->active_media_state->default_session[AST_MEDIA_TYPE_VIDEO] : NULL;
    ao2_replace(info->video_rtp, media ? media->rtp : NULL);
    info->video_secure = media && media->srtp
        && ast_test_flag(media->srtp, AST_SRTP_CRYPTO_OFFER_OK);
    info->video_held = media && media->remotely_held;
}

References ao2_replace, ast_free, ast_log, AST_MEDIA_TYPE_AUDIO, AST_MEDIA_TYPE_VIDEO, ast_sip_get_pjsip_endpoint(), AST_SRTP_CRYPTO_OFFER_OK, ast_strndup, ast_test_flag, copy(), copy_uri(), LOG_WARNING, NULL, ast_sip_session_media::remotely_held, ast_sip_session_media::rtp, session, and ast_sip_session_media::srtp.

Referenced by pjsip_channel_info_create(), and pjsip_channel_info_update().

channel_info_update_task()

static int channel_info_update_task ( void *  data )

static

Definition at line 229 of file channel_info.c.

{
    struct ast_sip_session *session = data;
 
    pjsip_channel_info_update(session);
    ao2_ref(session, -1);
    return 0;
}

References ao2_ref, pjsip_channel_info_update(), and session.

Referenced by pjsip_channel_info_schedule_update().

copy_uri()

static int copy_uri ( struct pjsip_channel_uri *  dest, pjsip_uri_context_e  context, const void *  uri, const char *  type  )

static

Definition at line 98 of file channel_info.c.

{
    char value[PJSIP_MAX_URL_SIZE] = "";
    int length = 0;
    int changed;
 
    if (uri) {
        length = pjsip_uri_print(context, uri, value, sizeof(value));
        if (length < 0 || length >= sizeof(value)) {
            ast_log(LOG_ERROR, "Unable to capture PJSIP %s in %zu bytes\n",
                type, sizeof(value));
            value[0] = '\0';
            length = -1;
        } else {
            value[length] = '\0';
        }
    }
    changed = dest->length != length || strcmp(dest->value, value);
    ast_copy_string(dest->value, value, sizeof(dest->value));
    dest->length = length;
    return changed;
}

References ast_copy_string(), ast_log, pjsip_channel_uri::length, LOG_ERROR, type, pjsip_channel_uri::value, and value.

Referenced by channel_info_update_locked().

pjsip_channel_info_create()

int pjsip_channel_info_create	(	struct ast_channel *	chan,
		struct ast_sip_session *	session
	)

Create channel-owned PJSIP information before channel publication.

Precondition

The caller holds the channel lock and executes in the session serializer.

Return values

0	on success
-1	on failure

Definition at line 187 of file channel_info.c.

{
    struct ast_datastore *datastore;
    struct pjsip_channel_info *info;
 
    datastore = ast_datastore_alloc(&channel_info_datastore, NULL);
    if (!datastore) {
        return -1;
    }
    info = ast_calloc(1, sizeof(*info));
    if (!info) {
        ast_datastore_free(datastore);
        return -1;
    }
    info->datastore = datastore;
    info->secure = -1;
    datastore->data = info;
 
    /* The caller holds the channel lock and is running in the serializer. */
    channel_info_update_locked(info, session);
    ast_channel_datastore_add(chan, datastore);
    return 0;
}

References ast_calloc, ast_channel_datastore_add(), ast_datastore_alloc, ast_datastore_free(), channel_info_datastore, channel_info_update_locked(), ast_datastore::data, pjsip_channel_info::datastore, NULL, and session.

Referenced by chan_pjsip_new().

pjsip_channel_info_get()

struct pjsip_channel_info * pjsip_channel_info_get

(

struct ast_channel *

chan

)

Find the channel's information, or NULL if it has none.

Precondition

The caller holds the channel lock.

Note

The result is borrowed and may only be used while the channel is locked. Do not release it with ao2_cleanup(). The channel datastore owns its lifetime.

Definition at line 89 of file channel_info.c.

{
    struct ast_datastore *datastore;
 
    datastore = ast_channel_datastore_find(chan, &channel_info_datastore, NULL);
    return datastore ? datastore->data : NULL;
}

References ast_channel_datastore_find(), channel_info_datastore, ast_datastore::data, and NULL.

Referenced by channel_read_pjsip(), pjsip_acf_channel_read(), and pjsip_channel_info_update().

pjsip_channel_info_register()

void pjsip_channel_info_register

(

void

)

Register the channel information session supplement.

Definition at line 289 of file channel_info.c.

{
    ast_sip_session_register_supplement(&channel_info_supplement);
}

References ast_sip_session_register_supplement, and channel_info_supplement.

Referenced by load_module().

pjsip_channel_info_schedule_update()

void pjsip_channel_info_schedule_update

(

struct ast_sip_session *

session

)

Schedule a refresh from any thread without waiting for the serializer.

Definition at line 238 of file channel_info.c.

{
    /*
     * Capture changes made after supplements or from an outgoing transport
     * callback outside the serializer. Never wait for the queued refresh.
     */
    if (ast_sip_push_task(session->serializer, channel_info_update_task,
        ao2_bump(session))) {
        ast_log(LOG_WARNING, "Unable to queue PJSIP channel information refresh for %s\n",
            ast_sip_session_get_name(session));
        ao2_ref(session, -1);
    }
}

References ao2_bump, ao2_ref, ast_log, ast_sip_push_task, ast_sip_session_get_name(), channel_info_update_task(), LOG_WARNING, and session.

Referenced by channel_info_incoming_request(), channel_info_incoming_response(), channel_info_outgoing_request(), and channel_info_outgoing_response().

pjsip_channel_info_unregister()

void pjsip_channel_info_unregister

(

void

)

Unregister the channel information session supplement.

Definition at line 294 of file channel_info.c.

{
    ast_sip_session_unregister_supplement(&channel_info_supplement);
}

References ast_sip_session_unregister_supplement(), and channel_info_supplement.

Referenced by load_module(), and unload_module().

pjsip_channel_info_update()

void pjsip_channel_info_update

(

struct ast_sip_session *

session

)

Refresh channel information under the channel lock.

Precondition

The caller executes in the session serializer.

Definition at line 212 of file channel_info.c.

{
    struct ast_channel *chan = session->channel;
    struct pjsip_channel_info *info;
 
    /* Serializer execution stabilizes session->channel across a masquerade. */
    if (!chan) {
        return;
    }
    ast_channel_lock(chan);
    info = pjsip_channel_info_get(chan);
    if (info) {
        channel_info_update_locked(info, session);
    }
    ast_channel_unlock(chan);
}

References ast_channel_lock, ast_channel_unlock, channel_info_update_locked(), pjsip_channel_info_get(), and session.

Referenced by channel_info_incoming_request(), channel_info_incoming_response(), channel_info_update_task(), and send_direct_media_request().

Variable Documentation

channel_info_datastore

const struct ast_datastore_info channel_info_datastore

static

Initial value:

= {
    .type = "chan_pjsip_channel_info",
    .destroy = channel_info_destroy,
    .chan_breakdown = channel_info_breakdown,
}

Definition at line 83 of file channel_info.c.

                                                                {
    .type = "chan_pjsip_channel_info",
    .destroy = channel_info_destroy,
    .chan_breakdown = channel_info_breakdown,
};

Referenced by pjsip_channel_info_create(), and pjsip_channel_info_get().

channel_info_supplement

struct ast_sip_session_supplement channel_info_supplement

static

Definition at line 279 of file channel_info.c.

                                                                   {
    /* Refresh before channel supplements publish snapshots or queue control frames. */
    .priority = AST_SIP_SUPPLEMENT_PRIORITY_CHANNEL - 1,
    .incoming_request = channel_info_incoming_request,
    .incoming_response = channel_info_incoming_response,
    .outgoing_request = channel_info_outgoing_request,
    .outgoing_response = channel_info_outgoing_response,
    .response_priority = AST_SIP_SESSION_AFTER_MEDIA,
};

Referenced by pjsip_channel_info_register(), and pjsip_channel_info_unregister().