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From: Andrei Emeltchenko <Andrei.Emeltchenko.news@gmail.com>
To: linux-bluetooth@vger.kernel.org
Subject: [RFC] android/avdtp: Fix SEID assignment
Date: Thu, 12 Feb 2015 13:00:18 +0200
Message-Id: <1423738818-30130-1-git-send-email-Andrei.Emeltchenko.news@gmail.com>
Sender: linux-bluetooth-owner@vger.kernel.org
List-ID: <linux-bluetooth.vger.kernel.org>

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Fixes SEID generation for avdtp. Currently SEIDs were assigned assuming
that SEID are registered and unregistered in the same order like:
seid = g_slist_length(seps) + 1
which makes it possible to reuse similar SEIDs
---
 android/avdtp.c   | 32 +++++++++++++++++++++++++++++---
 unit/test-avdtp.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/android/avdtp.c b/android/avdtp.c
index 22c492b..20f27d4 100644
--- a/android/avdtp.c
+++ b/android/avdtp.c
@@ -45,6 +45,7 @@
 #include "../profiles/audio/a2dp-codecs.h"
 
 #define MAX_SEID 0x3E
+static uint64_t seids;
 
 #ifndef MAX
 # define MAX(x, y) ((x) > (y) ? (x) : (y))
@@ -3350,20 +3351,44 @@ int avdtp_delay_report(struct avdtp *session, struct avdtp_stream *stream,
 							&req, sizeof(req));
 }
 
+static uint8_t avdtp_get_seid(void)
+{
+	uint64_t temp = seids;
+	uint8_t id = 1;
+
+	while (temp >>= 1)
+		id++;
+
+	if (id > MAX_SEID)
+		return 0;
+
+	seids |= (uint64_t) (0x01l << id);
+
+	DBG("seids 0x%04lx id %d", seids, id);
+
+	return id;
+}
+
+static void avdtp_clear_seid(uint8_t seid)
+{
+	seids &= ~(0x1l<<seid);
+
+	DBG("seids 0x%04lx cleared bit %d ", seids, seid);
+}
+
 struct avdtp_local_sep *avdtp_register_sep(uint8_t type, uint8_t media_type,
 						uint8_t codec_type,
 						gboolean delay_reporting,
 						struct avdtp_sep_ind *ind,
 						struct avdtp_sep_cfm *cfm,
-						void *user_data,
-						uint8_t seid)
+						void *user_data, uint8_t seid)
 {
 	struct avdtp_local_sep *sep;
 
 	sep = g_new0(struct avdtp_local_sep, 1);
 
 	sep->state = AVDTP_STATE_IDLE;
-	sep->info.seid = seid;
+	sep->info.seid = avdtp_get_seid();
 	sep->info.type = type;
 	sep->info.media_type = media_type;
 	sep->codec = codec_type;
@@ -3396,6 +3421,7 @@ int avdtp_unregister_sep(struct avdtp_local_sep *sep)
 	DBG("SEP %p unregistered: type:%d codec:%d seid:%d", sep,
 			sep->info.type, sep->codec, sep->info.seid);
 
+	avdtp_clear_seid(sep->info.seid);
 	g_free(sep);
 
 	return 0;
diff --git a/unit/test-avdtp.c b/unit/test-avdtp.c
index 03fd4b1..00b72f1 100644
--- a/unit/test-avdtp.c
+++ b/unit/test-avdtp.c
@@ -39,6 +39,8 @@
 #include "src/log.h"
 #include "android/avdtp.h"
 
+#define MAX_SEID 0x3E
+
 GSList *lseps = NULL;
 
 struct test_pdu {
@@ -567,6 +569,35 @@ static void test_server_0_sep(gconstpointer data)
 	execute_context(context);
 }
 
+static void unregister_sep(gpointer data, gpointer user_data)
+{
+	struct avdtp_local_sep *sep = data;
+
+	lseps = g_slist_remove(lseps, sep);
+	avdtp_unregister_sep(sep);
+}
+
+static void test_server_seid(gconstpointer data)
+{
+	struct context *context = create_context(0x0103, data);
+	struct avdtp_local_sep *sep;
+	int i;
+
+	for (i = 0; i < MAX_SEID; i++) {
+		sep = avdtp_register_sep(AVDTP_SEP_TYPE_SINK,
+						AVDTP_MEDIA_TYPE_AUDIO,
+						0x00, TRUE, &sep_ind, NULL,
+						context,
+						g_slist_length(lseps) + 1);
+		g_assert(sep);
+
+		lseps = g_slist_append(lseps, sep);
+		avdtp_set_lseps(context->session, lseps);
+	}
+
+	g_slist_foreach(lseps, unregister_sep, NULL);
+}
+
 static gboolean sep_getcap_ind_frg(struct avdtp *session,
 					struct avdtp_local_sep *sep,
 					GSList **caps, uint8_t *err,
@@ -774,6 +805,8 @@ int main(int argc, char *argv[])
 	 * To verify that the following procedures are implemented according to
 	 * their specification in AVDTP.
 	 */
+	define_test("/TP/SIG/SMG/BV-06-C-SEID-1", test_server_seid,
+			raw_pdu(0x00));
 	define_test("/TP/SIG/SMG/BV-05-C", test_client,
 			raw_pdu(0x00, 0x01));
 	define_test("/TP/SIG/SMG/BV-06-C", test_server,
-- 
2.1.0