chan_pjsip: add allow_sending_180_after_183 option

added new global config option "allow_sending_180_after_183"
that if enabled will preserve 180 after a 183

ASTERISK-29842

Change-Id: I8a53f8c35595b6d16d8e86e241b5f110d92f3d18

channels/chan_pjsip.c

@@ -1630,8 +1630,12 @@ static int chan_pjsip_indicate(struct ast_channel *ast, int condition, const voi
 			if (channel->session->endpoint->inband_progress ||
 				(channel->session->inv_session && channel->session->inv_session->neg &&
 				pjmedia_sdp_neg_get_state(channel->session->inv_session->neg) == PJMEDIA_SDP_NEG_STATE_DONE)) {
-				response_code = 183;
 				res = -1;
+				if (ast_sip_get_allow_sending_180_after_183()) {
+					response_code = 180;
+				} else {
+					response_code = 183;
+				}
 			} else {
 				response_code = 180;
 			}

configs/samples/pjsip.conf.sample

@@ -1311,6 +1311,12 @@
                     ; creating an implicit subscription (see RFC 4488).
                     ; (default: "yes")
 
+;allow_sending_180_after_183=yes	; Allow Asterisk to send 180 Ringing to an endpoint
+					; after 183 Session Progress has been send.
+					; If disabled Asterisk will instead send only a
+					; 183 Session Progress to the endpoint.
+					; (default: "no")
+
 ; MODULE PROVIDING BELOW SECTION(S): res_pjsip_acl
 ;==========================ACL SECTION OPTIONS=========================
 ;[acl]

contrib/ast-db-manage/config/versions/0bee61aa9425_allow_180_ringing_with_sdp.py

@@ -0,0 +1,36 @@
+"""allow_sending_180_after_183
+
+Revision ID: 0bee61aa9425
+Revises: 8f72185e437f
+Create Date: 2022-04-07 13:51:33.400664
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import ENUM
+
+# revision identifiers, used by Alembic.
+revision = '0bee61aa9425'
+down_revision = '8f72185e437f'
+AST_BOOL_NAME = 'ast_bool_values'
+# We'll just ignore the n/y and f/t abbreviations as Asterisk does not write
+# those aliases.
+AST_BOOL_VALUES = [ '0', '1',
+                    'off', 'on',
+                    'false', 'true',
+                    'no', 'yes' ]
+
+def upgrade():
+    ############################# Enums ##############################
+
+    # ast_bool_values has already been created, so use postgres enum object
+    # type to get around "already created" issue - works okay with mysql
+    ast_bool_values = ENUM(*AST_BOOL_VALUES, name=AST_BOOL_NAME, create_type=False)
+
+    op.add_column('ps_globals', sa.Column('allow_sending_180_after_183', ast_bool_values))
+
+
+def downgrade():
+    if op.get_context().bind.dialect.name == 'mssql':
+        op.drop_constraint('ck_ps_globals_allow_sending_180_after_183_ast_bool_values', 'ps_globals')
+    op.drop_column('ps_globals', 'allow_sending_180_after_183')

doc/CHANGES-staging/chan_pjsip_180_sdp.txt

@@ -0,0 +1,8 @@
+Subject: chan_pjsip
+
+added global config option "allow_sending_180_after_183"
+
+Allow Asterisk to send 180 Ringing to an endpoint
+after 183 Session Progress has been send.
+If disabled Asterisk will instead send only a
+183 Session Progress to the endpoint.

include/asterisk/res_pjsip.h

@@ -3065,6 +3065,13 @@ int ast_sip_get_mwi_tps_queue_low(void);
  */
 unsigned int ast_sip_get_mwi_disable_initial_unsolicited(void);
 
+/*!
+ * \brief Retrieve the global setting 'allow_sending_180_after_183'.
+ *
+ * \retval non zero if disable.
+ */
+unsigned int ast_sip_get_allow_sending_180_after_183(void);
+
 /*!
  * \brief Retrieve the global setting 'use_callerid_contact'.
  * \since 13.24.0

res/res_pjsip/config_global.c

@@ -48,6 +48,7 @@
 #define DEFAULT_MWI_TPS_QUEUE_HIGH AST_TASKPROCESSOR_HIGH_WATER_LEVEL
 #define DEFAULT_MWI_TPS_QUEUE_LOW -1
 #define DEFAULT_MWI_DISABLE_INITIAL_UNSOLICITED 0
+#define DEFAULT_ALLOW_SENDING_180_AFTER_183 0
 #define DEFAULT_IGNORE_URI_USER_OPTIONS 0
 #define DEFAULT_USE_CALLERID_CONTACT 0
 #define DEFAULT_SEND_CONTACT_STATUS_ON_UPDATE_REGISTRATION 0
@@ -92,6 +93,8 @@ struct global_config {
 	unsigned int contact_expiration_check_interval;
 	/*! Nonzero to disable multi domain support */
 	unsigned int disable_multi_domain;
+	/*! Nonzero to disable changing 180/SDP to 183/SDP */
+	unsigned int allow_sending_180_after_183;
 	/*! The maximum number of unidentified requests per source IP address before a security event is logged */
 	unsigned int unidentified_request_count;
 	/*! The period during which unidentified requests are accumulated */
@@ -444,6 +447,21 @@ unsigned int ast_sip_get_mwi_disable_initial_unsolicited(void)
 	return disable_initial_unsolicited;
 }
 
+unsigned int ast_sip_get_allow_sending_180_after_183(void)
+{
+	unsigned int allow_sending_180_after_183;
+	struct global_config *cfg;
+
+	cfg = get_global_cfg();
+	if (!cfg) {
+		return DEFAULT_ALLOW_SENDING_180_AFTER_183;
+	}
+
+	allow_sending_180_after_183 = cfg->allow_sending_180_after_183;
+	ao2_ref(cfg, -1);
+	return allow_sending_180_after_183;
+}
+
 unsigned int ast_sip_get_ignore_uri_user_options(void)
 {
 	unsigned int ignore_uri_user_options;
@@ -708,6 +726,9 @@ int ast_sip_initialize_sorcery_global(void)
 	ast_sorcery_object_field_register(sorcery, "global", "mwi_disable_initial_unsolicited",
 		DEFAULT_MWI_DISABLE_INITIAL_UNSOLICITED ? "yes" : "no",
 		OPT_BOOL_T, 1, FLDSET(struct global_config, mwi.disable_initial_unsolicited));
+	ast_sorcery_object_field_register(sorcery, "global", "allow_sending_180_after_183",
+		DEFAULT_ALLOW_SENDING_180_AFTER_183 ? "yes" : "no",
+		OPT_BOOL_T, 1, FLDSET(struct global_config, allow_sending_180_after_183));
 	ast_sorcery_object_field_register(sorcery, "global", "ignore_uri_user_options",
 		DEFAULT_IGNORE_URI_USER_OPTIONS ? "yes" : "no",
 		OPT_BOOL_T, 1, FLDSET(struct global_config, ignore_uri_user_options));

res/res_pjsip/pjsip_config.xml

@@ -2348,6 +2348,17 @@
 				<configOption name="norefersub" default="yes">
 					<synopsis>Advertise support for RFC4488 REFER subscription suppression</synopsis>
 				</configOption>
+				<configOption name="allow_sending_180_after_183" default="no">
+					<synopsis>Allow 180 after 183</synopsis>
+					<description><para>
+						Allow Asterisk to send 180 Ringing to an endpoint
+						after 183 Session Progress has been send.
+						If disabled Asterisk will instead send only a
+						183 Session Progress to the endpoint.
+						(default: "no")
+						</para>
+					</description>
+				</configOption>
 			</configObject>
 		</configFile>
 	</configInfo>