stream: Enforce formats immutability and ensure formats exist.

Some places in Asterisk did not treat the formats on a stream
as immutable when they are.

The ast_stream_get_formats function is now const to enforce this
and parts of Asterisk have been updated to take this into account.
Some violations of this were also fixed along the way.

An additional minor tweak is that streams are now allocated with
an empty format capabilities structure removing the need in various
places to check that one is present on the stream.

ASTERISK-28846

Change-Id: I32f29715330db4ff48edd6f1f359090458a9bfbe

diff --git a/bridges/bridge_native_rtp.c b/bridges/bridge_native_rtp.c
index a6addf27110391fbfebb56ba8bc1eab5ec296486..19c6ab525b42058c9fe1c51fbb65c2d946b1acb0 100644 (file)
--- a/bridges/bridge_native_rtp.c
+++ b/bridges/bridge_native_rtp.c
@@ -859,7 +859,7 @@ static struct ast_stream_topology *native_rtp_request_stream_topology_update(
        struct ast_stream_topology *requested_topology)
 {
        struct ast_stream *stream;
-       struct ast_format_cap *audio_formats = NULL;
+       const struct ast_format_cap *audio_formats = NULL;
        struct ast_stream_topology *new_topology;
        int i;
 
@@ -886,6 +886,8 @@ static struct ast_stream_topology *native_rtp_request_stream_topology_update(
 
        if (audio_formats) {
                for (i = 0; i < ast_stream_topology_get_count(new_topology); ++i) {
+                       struct ast_format_cap *joint;
+
                        stream = ast_stream_topology_get_stream(new_topology, i);
 
                        if (ast_stream_get_type(stream) != AST_MEDIA_TYPE_AUDIO ||
@@ -893,8 +895,16 @@ static struct ast_stream_topology *native_rtp_request_stream_topology_update(
                                continue;
                        }
 
-                       ast_format_cap_append_from_cap(ast_stream_get_formats(stream), audio_formats,
+                       joint = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+                       if (!joint) {
+                               continue;
+                       }
+
+                       ast_format_cap_append_from_cap(joint, ast_stream_get_formats(stream),
                                AST_MEDIA_TYPE_AUDIO);
+                       ast_format_cap_append_from_cap(joint, audio_formats, AST_MEDIA_TYPE_AUDIO);
+                       ast_stream_set_formats(stream, joint);
+                       ao2_ref(joint, -1);
                }
        }
 

diff --git a/bridges/bridge_simple.c b/bridges/bridge_simple.c
index 545b3ad1cbe04be718e22dfe757ac239184d1ff6..abda774dd58a02d8f579e9b0c241600b739d5930 100644 (file)
--- a/bridges/bridge_simple.c
+++ b/bridges/bridge_simple.c
@@ -63,7 +63,7 @@ static struct ast_stream_topology *simple_bridge_request_stream_topology_update(
        struct ast_stream_topology *requested_topology)
 {
        struct ast_stream *stream;
-       struct ast_format_cap *audio_formats = NULL;
+       const struct ast_format_cap *audio_formats = NULL;
        struct ast_stream_topology *new_topology;
        int i;
 
@@ -90,6 +90,8 @@ static struct ast_stream_topology *simple_bridge_request_stream_topology_update(
 
        if (audio_formats) {
                for (i = 0; i < ast_stream_topology_get_count(new_topology); ++i) {
+                       struct ast_format_cap *joint;
+
                        stream = ast_stream_topology_get_stream(new_topology, i);
 
                        if (ast_stream_get_type(stream) != AST_MEDIA_TYPE_AUDIO ||
@@ -97,8 +99,16 @@ static struct ast_stream_topology *simple_bridge_request_stream_topology_update(
                                continue;
                        }
 
-                       ast_format_cap_append_from_cap(ast_stream_get_formats(stream), audio_formats,
+                       joint = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+                       if (!joint) {
+                               continue;
+                       }
+
+                       ast_format_cap_append_from_cap(joint, ast_stream_get_formats(stream),
                                AST_MEDIA_TYPE_AUDIO);
+                       ast_format_cap_append_from_cap(joint, audio_formats, AST_MEDIA_TYPE_AUDIO);
+                       ast_stream_set_formats(stream, joint);
+                       ao2_ref(joint, -1);
                }
        }
 

diff --git a/bridges/bridge_softmix.c b/bridges/bridge_softmix.c
index e1c673496667c183fb0ecb34cbab08ba139e1b67..09218ce99650c664f405590d1d63a2274518334a 100644 (file)
--- a/bridges/bridge_softmix.c
+++ b/bridges/bridge_softmix.c
@@ -2575,7 +2575,7 @@ fail:
 static int validate_stream(struct ast_test *test, struct ast_stream *stream,
        const struct stream_parameters *params)
 {
-       struct ast_format_cap *stream_caps;
+       const struct ast_format_cap *stream_caps;
        struct ast_format_cap *params_caps;
 
        if (ast_stream_get_type(stream) != params->type) {

diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index 5df39c3bd6ace01bf9fee248299832f1c622e71f..99ef6440daea099317d07f33f19cd1d667e83e41 100644 (file)
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -820,7 +820,7 @@ static int is_compatible_format(struct ast_sip_session *session, struct ast_fram
 {
        struct ast_stream_topology *topology = session->active_media_state->topology;
        struct ast_stream *stream = ast_stream_topology_get_stream(topology, f->stream_num);
-       struct ast_format_cap *cap = ast_stream_get_formats(stream);
+       const struct ast_format_cap *cap = ast_stream_get_formats(stream);
 
        return ast_format_cap_iscompatible_format(cap, f->subclass.format) != AST_FORMAT_CMP_NOT_EQUAL;
 }

diff --git a/channels/pjsip/dialplan_functions.c b/channels/pjsip/dialplan_functions.c
index 7cc4506a5e8b4ca0fc0515c08b4ea4cbe73082ff..2ace3ade3814717a7c735ba1fbde908276fdc0d7 100644 (file)
--- a/channels/pjsip/dialplan_functions.c
+++ b/channels/pjsip/dialplan_functions.c
@@ -1235,7 +1235,7 @@ static int media_offer_read_av(struct ast_sip_session *session, char *buf,
        struct ast_stream_topology *topology;
        int idx;
        struct ast_stream *stream = NULL;
-       struct ast_format_cap *caps;
+       const struct ast_format_cap *caps;
        size_t accum = 0;
 
        if (session->inv_session->dlg->state == PJSIP_DIALOG_STATE_ESTABLISHED) {
@@ -1352,9 +1352,18 @@ static int media_offer_write_av(void *obj)
        if (!stream) {
                return 0;
        }
-       caps = ast_stream_get_formats(stream);
+
+       caps = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+       if (!caps) {
+               return -1;
+       }
+
+       ast_format_cap_append_from_cap(caps, ast_stream_get_formats(stream),
+               AST_MEDIA_TYPE_UNKNOWN);
        ast_format_cap_remove_by_type(caps, data->media_type);
        ast_format_cap_update_by_allow_disallow(caps, data->value, 1);
+       ast_stream_set_formats(stream, caps);
+       ao2_ref(caps, -1);
 
        return 0;
 }

diff --git a/doc/UPGRADE-staging/stream_immutable_formats.txt b/doc/UPGRADE-staging/stream_immutable_formats.txt
new file mode 100644 (file)
index 0000000..2af5d9b
--- /dev/null
+++ b/doc/UPGRADE-staging/stream_immutable_formats.txt
@@ -0,0 +1,9 @@
+Subject: Core
+
+The streams API function ast_stream_get_formats is
+now defined as returning the format capabilities const.
+This has always been the case but was never enforced
+through the API itself. Any consumer of this API that
+is not treating the formats as immutable should update
+their code to create a new format capabilities and set
+it on the stream instead.

diff --git a/include/asterisk/stream.h b/include/asterisk/stream.h
index 17275c58ae6444dd923ba6b4d1e8b77fac288cc1..bbeeacb06aea836bba58e15f7e8c3154aba23420 100644 (file)
--- a/include/asterisk/stream.h
+++ b/include/asterisk/stream.h
@@ -164,7 +164,7 @@ void ast_stream_set_type(struct ast_stream *stream, enum ast_media_type type);
  *
  * \since 15
  */
-struct ast_format_cap *ast_stream_get_formats(const struct ast_stream *stream);
+const struct ast_format_cap *ast_stream_get_formats(const struct ast_stream *stream);
 
 /*!
  * \brief Get the count of the current negotiated formats of a stream

diff --git a/main/stream.c b/main/stream.c
index 41b7948d3f9a46e2b770f20f9174cd2c020c13d8..5966a86f3ac7a7d443e1c0dfbada7397197ec305 100644 (file)
--- a/main/stream.c
+++ b/main/stream.c
@@ -108,6 +108,12 @@ struct ast_stream *ast_stream_alloc(const char *name, enum ast_media_type type)
        stream->group = -1;
        strcpy(stream->name, S_OR(name, "")); /* Safe */
 
+       stream->formats = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
+       if (!stream->formats) {
+               ast_free(stream);
+               return NULL;
+       }
+
        return stream;
 }
 
@@ -179,7 +185,7 @@ void ast_stream_set_type(struct ast_stream *stream, enum ast_media_type type)
        stream->type = type;
 }
 
-struct ast_format_cap *ast_stream_get_formats(const struct ast_stream *stream)
+const struct ast_format_cap *ast_stream_get_formats(const struct ast_stream *stream)
 {
        ast_assert(stream != NULL);
 

diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index 558e706a0bae934ad46c9a64e3083b25a5d91562..67899e4180e4db0c18d92bfead9d8673b1acaac2 100644 (file)
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -1752,9 +1752,11 @@ static int sip_session_refresh(struct ast_sip_session *session,
                                                        continue;
                                                } else {
                                                        /* However if the stream is otherwise remaining the same we can keep the formats
-                                                        * that exist on it already which allows media to continue to flow.
+                                                        * that exist on it already which allows media to continue to flow. We don't modify
+                                                        * the format capabilities but do need to cast it so that ao2_bump can raise the
+                                                        * reference count.
                                                         */
-                                                       joint_cap = ao2_bump(ast_stream_get_formats(existing_stream));
+                                                       joint_cap = ao2_bump((struct ast_format_cap *)ast_stream_get_formats(existing_stream));
                                                }
                                        }
                                        ast_stream_set_formats(stream, joint_cap);

diff --git a/res/res_pjsip_session/pjsip_session_caps.c b/res/res_pjsip_session/pjsip_session_caps.c
index 7aa4c1fd49f7a525227b414692162cf1b3f3c742..ca7ef4463895cd2a5da8feaf26ae75732a72c8e3 100644 (file)
--- a/res/res_pjsip_session/pjsip_session_caps.c
+++ b/res/res_pjsip_session/pjsip_session_caps.c
@@ -122,7 +122,7 @@ struct ast_stream *ast_sip_session_create_joint_call_stream(const struct ast_sip
        struct ast_stream *remote_stream)
 {
        struct ast_stream *joint_stream = ast_stream_clone(remote_stream, NULL);
-       struct ast_format_cap *remote = ast_stream_get_formats(remote_stream);
+       const struct ast_format_cap *remote = ast_stream_get_formats(remote_stream);
        enum ast_media_type media_type = ast_stream_get_type(remote_stream);
 
        struct ast_format_cap *joint = ast_sip_create_joint_call_cap(remote,