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res_pjsip_registrar.c: Update remove_existing AOR contact handling.

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When "rewrite_contact" is enabled, the "max_contacts" count option can
block re-registrations because the source port from the endpoint can be
random.  When the re-registration is blocked, the endpoint may give up
re-registering and require manual intervention.

* The "remove_existing" option now allows a registration to succeed by
displacing any existing contacts that now exceed the "max_contacts" count.
Any removed contacts are the next to expire.  The behaviour change is
beneficial when "rewrite_contact" is enabled and "max_contacts" is greater
than one.  The removed contact is likely the old contact created by
"rewrite_contact" that the device is refreshing.

ASTERISK-27192

Change-Id: I64c107a10b70db1697d17136051ae6bf22b5314b
This commit is contained in:
Richard Mudgett
2017-09-20 18:36:15 -05:00
parent 39b68a41f7
commit d388c18abf
5 changed files with 192 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
res/res_pjsip.c
View File

@@ -1408,6 +1408,18 @@
It only limits contacts added through external interaction, such as
registration.
</para>
<note><para>The <replaceable>rewrite_contact</replaceable> option
registers the source address as the contact address to help with
NAT and reusing connection oriented transports such as TCP and
TLS. Unfortunately, refreshing a registration may register a
different contact address and exceed
<replaceable>max_contacts</replaceable>. The
<replaceable>remove_existing</replaceable> option can help by
removing the soonest to expire contact(s) over
<replaceable>max_contacts</replaceable> which is likely the
old <replaceable>rewrite_contact</replaceable> contact source
address being refreshed.
</para></note>
<note><para>This should be set to <literal>1</literal> and
<replaceable>remove_existing</replaceable> set to <literal>yes</literal> if you
wish to stick with the older <literal>chan_sip</literal> behaviour.
@@ -1417,15 +1429,29 @@
<configOption name="minimum_expiration" default="60">
<synopsis>Minimum keep alive time for an AoR</synopsis>
<description><para>
Minimum time to keep a peer with an explict expiration. Time in seconds.
Minimum time to keep a peer with an explicit expiration. Time in seconds.
</para></description>
</configOption>
<configOption name="remove_existing" default="no">
<synopsis>Determines whether new contacts replace existing ones.</synopsis>
<description><para>
On receiving a new registration to the AoR should it remove
the existing contact that was registered against it?
On receiving a new registration to the AoR should it remove enough
existing contacts not added or updated by the registration to
satisfy <replaceable>max_contacts</replaceable>? Any removed
contacts will expire the soonest.
</para>
<note><para>The <replaceable>rewrite_contact</replaceable> option
registers the source address as the contact address to help with
NAT and reusing connection oriented transports such as TCP and
TLS. Unfortunately, refreshing a registration may register a
different contact address and exceed
<replaceable>max_contacts</replaceable>. The
<replaceable>remove_existing</replaceable> option can help by
removing the soonest to expire contact(s) over
<replaceable>max_contacts</replaceable> which is likely the
old <replaceable>rewrite_contact</replaceable> contact source
address being refreshed.
</para></note>
<note><para>This should be set to <literal>yes</literal> and
<replaceable>max_contacts</replaceable> set to <literal>1</literal> if you
wish to stick with the older <literal>chan_sip</literal> behaviour.

156
res/res_pjsip_registrar.c
View File

@@ -129,7 +129,8 @@ static int registrar_find_contact(void *obj, void *arg, int flags)
/*! \brief Internal function which validates provided Contact headers to confirm that they are acceptable, and returns number of contacts */
static int registrar_validate_contacts(const pjsip_rx_data *rdata, struct ao2_container *contacts, struct ast_sip_aor *aor, int *added, int *updated, int *deleted)
{
pjsip_contact_hdr *previous = NULL, *contact = (pjsip_contact_hdr *)&rdata->msg_info.msg->hdr;
pjsip_contact_hdr *previous = NULL;
pjsip_contact_hdr *contact = (pjsip_contact_hdr *)&rdata->msg_info.msg->hdr;
struct registrar_contact_details details = {
.pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(), "Contact Comparison", 256, 256),
};
@@ -140,15 +141,18 @@ static int registrar_validate_contacts(const pjsip_rx_data *rdata, struct ao2_co
while ((contact = (pjsip_contact_hdr *) pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_CONTACT, contact->next))) {
int expiration = registrar_get_expiration(aor, contact, rdata);
RAII_VAR(struct ast_sip_contact *, existing, NULL, ao2_cleanup);
struct ast_sip_contact *existing;
char contact_uri[pjsip_max_url_size];
if (contact->star) {
/* The expiration MUST be 0 when a '*' contact is used and there must be no other contact */
if ((expiration != 0) || previous) {
if (expiration != 0 || previous) {
pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), details.pool);
return -1;
}
/* Count all contacts to delete */
*deleted = ao2_container_count(contacts);
previous = contact;
continue;
} else if (previous && previous->star) {
/* If there is a previous contact and it is a '*' this is a deal breaker */
@@ -177,14 +181,16 @@ static int registrar_validate_contacts(const pjsip_rx_data *rdata, struct ao2_co
}
/* Determine if this is an add, update, or delete for policy enforcement purposes */
if (!(existing = ao2_callback(contacts, 0, registrar_find_contact, &details))) {
existing = ao2_callback(contacts, 0, registrar_find_contact, &details);
ao2_cleanup(existing);
if (!existing) {
if (expiration) {
(*added)++;
++*added;
}
} else if (expiration) {
(*updated)++;
++*updated;
} else {
(*deleted)++;
++*deleted;
}
}
@@ -219,7 +225,7 @@ static int registrar_delete_contact(void *obj, void *arg, int flags)
contact->user_agent);
}
return 0;
return CMP_MATCH;
}
/*! \brief Internal function which adds a contact to a response */
@@ -351,6 +357,96 @@ static void register_contact_transport_shutdown_cb(void *data)
ast_named_lock_put(lock);
}
AST_VECTOR(excess_contact_vector, struct ast_sip_contact *);
static int vec_contact_cmp(struct ast_sip_contact *left, struct ast_sip_contact *right)
{
struct ast_sip_contact *left_contact = left;
struct ast_sip_contact *right_contact = right;
/* Sort from soonest to expire to last to expire */
return ast_tvcmp(left_contact->expiration_time, right_contact->expiration_time);
}
static int vec_contact_add(void *obj, void *arg, int flags)
{
struct ast_sip_contact *contact = obj;
struct excess_contact_vector *contact_vec = arg;
/*
* Performance wise, an insertion sort is fine because we
* shouldn't need to remove more than a handful of contacts.
* I expect we'll typically be removing only one contact.
*/
AST_VECTOR_ADD_SORTED(contact_vec, contact, vec_contact_cmp);
if (AST_VECTOR_SIZE(contact_vec) == AST_VECTOR_MAX_SIZE(contact_vec)) {
/*
* We added a contact over the number we need to remove.
* Remove the longest to expire contact from the vector
* which is the last element in the vector. It may be
* the one we just added or the one we just added pushed
* out an earlier contact from removal consideration.
*/
--AST_VECTOR_SIZE(contact_vec);
}
return 0;
}
/*!
* \internal
* \brief Remove excess existing contacts that expire the soonest.
* \since 13.18.0
*
* \param contacts Container of unmodified contacts that could remove.
* \param to_remove Maximum number of contacts to remove.
*
* \return Nothing
*/
static void remove_excess_contacts(struct ao2_container *contacts, unsigned int to_remove)
{
struct excess_contact_vector contact_vec;
/*
* Create a sorted vector to hold the to_remove soonest to
* expire contacts. The vector has an extra space to
* temporarily hold the longest to expire contact that we
* won't remove.
*/
if (AST_VECTOR_INIT(&contact_vec, to_remove + 1)) {
return;
}
ao2_callback(contacts, OBJ_NODATA | OBJ_MULTIPLE, vec_contact_add, &contact_vec);
/*
* The vector should always be populated with the number
* of contacts we need to remove. Just in case, we will
* remove all contacts in the vector even if the contacts
* container had fewer contacts than there should be.
*/
ast_assert(AST_VECTOR_SIZE(&contact_vec) == to_remove);
to_remove = AST_VECTOR_SIZE(&contact_vec);
/* Remove the excess contacts that expire the soonest */
while (to_remove--) {
struct ast_sip_contact *contact;
contact = AST_VECTOR_GET(&contact_vec, to_remove);
ast_sip_location_delete_contact(contact);
ast_verb(3, "Removed contact '%s' from AOR '%s' due to remove_existing\n",
contact->uri, contact->aor);
ast_test_suite_event_notify("AOR_CONTACT_REMOVED",
"Contact: %s\r\n"
"AOR: %s\r\n"
"UserAgent: %s",
contact->uri,
contact->aor,
contact->user_agent);
}
AST_VECTOR_FREE(&contact_vec);
}
static int register_aor_core(pjsip_rx_data *rdata,
struct ast_sip_endpoint *endpoint,
struct ast_sip_aor *aor,
@@ -359,7 +455,10 @@ static int register_aor_core(pjsip_rx_data *rdata,
{
static const pj_str_t USER_AGENT = { "User-Agent", 10 };
int added = 0, updated = 0, deleted = 0;
int added = 0;
int updated = 0;
int deleted = 0;
int contact_count;
pjsip_contact_hdr *contact_hdr = NULL;
struct registrar_contact_details details = { 0, };
pjsip_tx_data *tdata;
@@ -396,7 +495,14 @@ static int register_aor_core(pjsip_rx_data *rdata,
return PJ_TRUE;
}
if ((MAX(added - deleted, 0) + (!aor->remove_existing ? ao2_container_count(contacts) : 0)) > aor->max_contacts) {
if (aor->remove_existing) {
/* Cumulative number of contacts affected by this registration */
contact_count = MAX(updated + added - deleted, 0);
} else {
/* Total contacts after this registration */
contact_count = ao2_container_count(contacts) + added - deleted;
}
if (contact_count > aor->max_contacts) {
/* Enforce the maximum number of contacts */
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 403, NULL, NULL, NULL);
ast_sip_report_failed_acl(endpoint, rdata, "registrar_attempt_exceeds_maximum_configured_contacts");
@@ -405,7 +511,9 @@ static int register_aor_core(pjsip_rx_data *rdata,
return PJ_TRUE;
}
if (!(details.pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(), "Contact Comparison", 256, 256))) {
details.pool = pjsip_endpt_create_pool(ast_sip_get_pjsip_endpoint(),
"Contact Comparison", 256, 256);
if (!details.pool) {
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
return PJ_TRUE;
}
@@ -446,7 +554,8 @@ static int register_aor_core(pjsip_rx_data *rdata,
if (contact_hdr->star) {
/* A star means to unregister everything, so do so for the possible contacts */
ao2_callback(contacts, OBJ_NODATA | OBJ_MULTIPLE, registrar_delete_contact, (void *)aor_name);
ao2_callback(contacts, OBJ_NODATA | OBJ_UNLINK | OBJ_MULTIPLE,
registrar_delete_contact, (void *)aor_name);
break;
}
@@ -459,7 +568,8 @@ static int register_aor_core(pjsip_rx_data *rdata,
details.uri = pjsip_uri_get_uri(contact_hdr->uri);
pjsip_uri_print(PJSIP_URI_IN_CONTACT_HDR, details.uri, contact_uri, sizeof(contact_uri));
if (!(contact = ao2_callback(contacts, OBJ_UNLINK, registrar_find_contact, &details))) {
contact = ao2_callback(contacts, OBJ_UNLINK, registrar_find_contact, &details);
if (!contact) {
int prune_on_boot = 0;
pj_str_t host_name;
@@ -600,15 +710,29 @@ static int register_aor_core(pjsip_rx_data *rdata,
pjsip_endpt_release_pool(ast_sip_get_pjsip_endpoint(), details.pool);
/* If the AOR is configured to remove any existing contacts that have not been updated/added as a result of this REGISTER
* do so
/*
* If the AOR is configured to remove any contacts over max_contacts
* that have not been updated/added/deleted as a result of this
* REGISTER do so.
*
* The contacts container currently holds the existing contacts that
* were not affected by this REGISTER.
*/
if (aor->remove_existing) {
ao2_callback(contacts, OBJ_NODATA | OBJ_MULTIPLE, registrar_delete_contact, NULL);
/* Total contacts after this registration */
contact_count = ao2_container_count(contacts) + updated + added;
if (contact_count > aor->max_contacts) {
/* Remove excess existing contacts that expire the soonest */
remove_excess_contacts(contacts, contact_count - aor->max_contacts);
}
}
/* Re-retrieve contacts. Caller will clean up the original container. */
contacts = ast_sip_location_retrieve_aor_contacts_nolock(aor);
if (!contacts) {
pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
return PJ_TRUE;
}
response_contact = ao2_callback(contacts, 0, NULL, NULL);
/* Send a response containing all of the contacts (including static) that are present on this AOR */