/*
* Copyright (c) 2014, Ericsson AB. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstdtlsdec.h"
#include "gstdtlscertificate.h"
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-dtls")
);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_REQUEST,
GST_STATIC_CAPS_ANY);
GST_DEBUG_CATEGORY_STATIC (gst_dtls_dec_debug);
#define GST_CAT_DEFAULT gst_dtls_dec_debug
#define gst_dtls_dec_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstDtlsDec, gst_dtls_dec, GST_TYPE_ELEMENT,
GST_DEBUG_CATEGORY_INIT (gst_dtls_dec_debug, "dtlsdec", 0, "DTLS Decoder"));
enum
{
SIGNAL_ON_KEY_RECEIVED,
NUM_SIGNALS
};
static guint signals[NUM_SIGNALS];
enum
{
PROP_0,
PROP_CONNECTION_ID,
PROP_PEM,
PROP_PEER_PEM,
PROP_DECODER_KEY,
PROP_SRTP_CIPHER,
PROP_SRTP_AUTH,
NUM_PROPERTIES
};
static GParamSpec *properties[NUM_PROPERTIES];
#define DEFAULT_CONNECTION_ID NULL
#define DEFAULT_PEM NULL
#define DEFAULT_PEER_PEM NULL
#define DEFAULT_DECODER_KEY NULL
#define DEFAULT_SRTP_CIPHER 0
#define DEFAULT_SRTP_AUTH 0
static void gst_dtls_dec_finalize (GObject *);
static void gst_dtls_dec_dispose (GObject *);
static void gst_dtls_dec_set_property (GObject *, guint prop_id,
const GValue *, GParamSpec *);
static void gst_dtls_dec_get_property (GObject *, guint prop_id, GValue *,
GParamSpec *);
static GstStateChangeReturn gst_dtls_dec_change_state (GstElement *,
GstStateChange);
static GstPad *gst_dtls_dec_request_new_pad (GstElement *, GstPadTemplate *,
const gchar * name, const GstCaps *);
static void gst_dtls_dec_release_pad (GstElement *, GstPad *);
static void on_key_received (GstDtlsConnection *, gpointer key, guint cipher,
guint auth, GstDtlsDec *);
static gboolean on_peer_certificate_received (GstDtlsConnection *, gchar * pem,
GstDtlsDec *);
static GstFlowReturn sink_chain (GstPad *, GstObject * parent, GstBuffer *);
static GstFlowReturn sink_chain_list (GstPad *, GstObject * parent,
GstBufferList *);
static GstDtlsAgent *get_agent_by_pem (const gchar * pem);
static void agent_weak_ref_notify (gchar * pem, GstDtlsAgent *);
static void create_connection (GstDtlsDec *, gchar * id);
static void connection_weak_ref_notify (gchar * id, GstDtlsConnection *);
static void
gst_dtls_dec_class_init (GstDtlsDecClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
gobject_class = (GObjectClass *) klass;
element_class = (GstElementClass *) klass;
gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_dtls_dec_finalize);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_dtls_dec_dispose);
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_dtls_dec_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_dtls_dec_get_property);
element_class->change_state = GST_DEBUG_FUNCPTR (gst_dtls_dec_change_state);
element_class->request_new_pad =
GST_DEBUG_FUNCPTR (gst_dtls_dec_request_new_pad);
element_class->release_pad = GST_DEBUG_FUNCPTR (gst_dtls_dec_release_pad);
signals[SIGNAL_ON_KEY_RECEIVED] =
g_signal_new ("on-key-received", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, 0, NULL, NULL,
g_cclosure_marshal_generic, G_TYPE_NONE, 0);
properties[PROP_CONNECTION_ID] =
g_param_spec_string ("connection-id",
"Connection id",
"Every encoder/decoder pair should have the same, unique, connection-id",
DEFAULT_CONNECTION_ID, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
properties[PROP_PEM] =
g_param_spec_string ("pem",
"PEM string",
"A string containing a X509 certificate and RSA private key in PEM format",
DEFAULT_PEM, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
properties[PROP_PEER_PEM] =
g_param_spec_string ("peer-pem",
"Peer PEM string",
"The X509 certificate received in the DTLS handshake, in PEM format",
DEFAULT_PEER_PEM, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
properties[PROP_DECODER_KEY] =
g_param_spec_boxed ("decoder-key",
"Decoder key",
"SRTP key that should be used by the decoder",
GST_TYPE_CAPS, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
properties[PROP_SRTP_CIPHER] =
g_param_spec_uint ("srtp-cipher",
"SRTP cipher",
"The SRTP cipher selected in the DTLS handshake. "
"The value will be set to an GstDtlsSrtpCipher.",
0, GST_DTLS_SRTP_CIPHER_AES_128_ICM, DEFAULT_SRTP_CIPHER,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
properties[PROP_SRTP_AUTH] =
g_param_spec_uint ("srtp-auth",
"SRTP authentication",
"The SRTP authentication selected in the DTLS handshake. "
"The value will be set to an GstDtlsSrtpAuth.",
0, GST_DTLS_SRTP_AUTH_HMAC_SHA1_80, DEFAULT_SRTP_AUTH,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, NUM_PROPERTIES, properties);
gst_element_class_add_static_pad_template (element_class, &src_template);
gst_element_class_add_static_pad_template (element_class, &sink_template);
gst_element_class_set_static_metadata (element_class,
"DTLS Decoder",
"Decoder/Network/DTLS",
"Decodes DTLS packets", "Patrik Oldsberg patrik.oldsberg@ericsson.com");
}
static void
gst_dtls_dec_init (GstDtlsDec * self)
{
self->agent = get_agent_by_pem (NULL);
self->connection_id = NULL;
self->connection = NULL;
self->peer_pem = NULL;
self->decoder_key = NULL;
self->srtp_cipher = DEFAULT_SRTP_CIPHER;
self->srtp_auth = DEFAULT_SRTP_AUTH;
g_mutex_init (&self->src_mutex);
self->src = NULL;
self->sink = gst_pad_new_from_static_template (&sink_template, "sink");
g_return_if_fail (self->sink);
gst_pad_set_chain_function (self->sink, GST_DEBUG_FUNCPTR (sink_chain));
gst_pad_set_chain_list_function (self->sink,
GST_DEBUG_FUNCPTR (sink_chain_list));
gst_element_add_pad (GST_ELEMENT (self), self->sink);
}
static void
gst_dtls_dec_finalize (GObject * object)
{
GstDtlsDec *self = GST_DTLS_DEC (object);
if (self->decoder_key) {
gst_buffer_unref (self->decoder_key);
self->decoder_key = NULL;
}
g_free (self->connection_id);
self->connection_id = NULL;
g_free (self->peer_pem);
self->peer_pem = NULL;
g_mutex_clear (&self->src_mutex);
GST_LOG_OBJECT (self, "finalized");
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_dtls_dec_dispose (GObject * object)
{
GstDtlsDec *self = GST_DTLS_DEC (object);
if (self->agent) {
g_object_unref (self->agent);
self->agent = NULL;
}
if (self->connection) {
g_object_unref (self->connection);
self->connection = NULL;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_dtls_dec_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstDtlsDec *self = GST_DTLS_DEC (object);
switch (prop_id) {
case PROP_CONNECTION_ID:
g_free (self->connection_id);
self->connection_id = g_value_dup_string (value);
g_return_if_fail (self->agent);
create_connection (self, self->connection_id);
break;
case PROP_PEM:
if (self->agent) {
g_object_unref (self->agent);
}
self->agent = get_agent_by_pem (g_value_get_string (value));
if (self->connection_id) {
create_connection (self, self->connection_id);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
}
}
static void
gst_dtls_dec_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstDtlsDec *self = GST_DTLS_DEC (object);
switch (prop_id) {
case PROP_CONNECTION_ID:
g_value_set_string (value, self->connection_id);
break;
case PROP_PEM:
g_value_take_string (value,
gst_dtls_agent_get_certificate_pem (self->agent));
break;
case PROP_PEER_PEM:
g_value_set_string (value, self->peer_pem);
break;
case PROP_DECODER_KEY:
g_value_set_boxed (value, self->decoder_key);
break;
case PROP_SRTP_CIPHER:
g_value_set_uint (value, self->srtp_cipher);
break;
case PROP_SRTP_AUTH:
g_value_set_uint (value, self->srtp_auth);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
}
}
static GstStateChangeReturn
gst_dtls_dec_change_state (GstElement * element, GstStateChange transition)
{
GstDtlsDec *self = GST_DTLS_DEC (element);
GstStateChangeReturn ret;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
if (self->connection) {
g_signal_connect_object (self->connection,
"on-decoder-key", G_CALLBACK (on_key_received), self, 0);
g_signal_connect_object (self->connection,
"on-peer-certificate", G_CALLBACK (on_peer_certificate_received),
self, 0);
} else {
GST_WARNING_OBJECT (self,
"trying to change state to ready without connection id and pem");
return GST_STATE_CHANGE_FAILURE;
}
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
return ret;
}
static gboolean
forward_sticky_events (GstPad * pad, GstEvent ** event, gpointer user_data)
{
GstPad *srcpad = GST_PAD_CAST (user_data);
GstFlowReturn ret;
ret = gst_pad_store_sticky_event (srcpad, *event);
if (ret != GST_FLOW_OK) {
GST_DEBUG_OBJECT (srcpad, "storing sticky event %p (%s) failed: %s", *event,
GST_EVENT_TYPE_NAME (*event), gst_flow_get_name (ret));
}
return TRUE;
}
static GstPad *
gst_dtls_dec_request_new_pad (GstElement * element,
GstPadTemplate * tmpl, const gchar * name, const GstCaps * caps)
{
GstDtlsDec *self = GST_DTLS_DEC (element);
GstPad *pad;
GST_DEBUG_OBJECT (element, "requesting pad");
g_return_val_if_fail (!self->src, NULL);
g_return_val_if_fail (tmpl->direction == GST_PAD_SRC, NULL);
g_mutex_lock (&self->src_mutex);
if (self->src) {
GST_ERROR_OBJECT (self, "Pad %s:%s exists already",
GST_DEBUG_PAD_NAME (self->src));
g_mutex_unlock (&self->src_mutex);
return NULL;
}
self->src = pad = gst_pad_new_from_template (tmpl, name);
g_mutex_unlock (&self->src_mutex);
gst_pad_set_active (pad, TRUE);
if (caps)
gst_pad_set_caps (pad, (GstCaps *) caps);
/* Forward sticky events to the new srcpad */
gst_pad_sticky_events_foreach (self->sink, forward_sticky_events, self->src);
gst_element_add_pad (element, pad);
return pad;
}
static void
gst_dtls_dec_release_pad (GstElement * element, GstPad * pad)
{
GstDtlsDec *self = GST_DTLS_DEC (element);
g_return_if_fail (self->src == pad);
g_mutex_lock (&self->src_mutex);
self->src = NULL;
g_mutex_unlock (&self->src_mutex);
GST_DEBUG_OBJECT (self, "releasing src pad");
gst_element_remove_pad (element, pad);
}
static void
on_key_received (GstDtlsConnection * connection, gpointer key, guint cipher,
guint auth, GstDtlsDec * self)
{
gpointer key_dup;
gchar *key_str;
g_return_if_fail (GST_IS_DTLS_DEC (self));
self->srtp_cipher = cipher;
self->srtp_auth = auth;
key_dup = g_memdup (key, GST_DTLS_SRTP_MASTER_KEY_LENGTH);
if (self->decoder_key) {
gst_buffer_unref (self->decoder_key);
self->decoder_key = NULL;
}
self->decoder_key =
gst_buffer_new_wrapped (key_dup, GST_DTLS_SRTP_MASTER_KEY_LENGTH);
key_str = g_base64_encode (key, GST_DTLS_SRTP_MASTER_KEY_LENGTH);
GST_INFO_OBJECT (self, "received key: %s", key_str);
g_free (key_str);
g_signal_emit (self, signals[SIGNAL_ON_KEY_RECEIVED], 0);
}
static gboolean
on_peer_certificate_received (GstDtlsConnection * connection, gchar * pem,
GstDtlsDec * self)
{
g_return_val_if_fail (GST_IS_DTLS_DEC (self), TRUE);
GST_DEBUG_OBJECT (self, "Received peer certificate PEM: \n%s", pem);
if (self->peer_pem != NULL) {
g_free (self->peer_pem);
self->peer_pem = NULL;
}
self->peer_pem = g_strdup (pem);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_PEER_PEM]);
return TRUE;
}
static gint
process_buffer (GstDtlsDec * self, GstBuffer * buffer)
{
GstMapInfo map_info;
gint size;
if (!gst_buffer_map (buffer, &map_info, GST_MAP_READWRITE))
return 0;
if (!map_info.size) {
gst_buffer_unmap (buffer, &map_info);
return 0;
}
size =
gst_dtls_connection_process (self->connection, map_info.data,
map_info.size);
gst_buffer_unmap (buffer, &map_info);
if (size <= 0)
return size;
gst_buffer_set_size (buffer, size);
return size;
}
static gboolean
process_buffer_from_list (GstBuffer ** buffer, guint idx, gpointer user_data)
{
GstDtlsDec *self = GST_DTLS_DEC (user_data);
gint size;
*buffer = gst_buffer_make_writable (*buffer);
size = process_buffer (self, *buffer);
if (size <= 0)
gst_buffer_replace (buffer, NULL);
return TRUE;
}
static GstFlowReturn
sink_chain_list (GstPad * pad, GstObject * parent, GstBufferList * list)
{
GstDtlsDec *self = GST_DTLS_DEC (parent);
GstFlowReturn ret = GST_FLOW_OK;
GstPad *other_pad;
list = gst_buffer_list_make_writable (list);
gst_buffer_list_foreach (list, process_buffer_from_list, self);
if (gst_buffer_list_length (list) == 0) {
GST_DEBUG_OBJECT (self, "Not produced any buffers");
gst_buffer_list_unref (list);
return GST_FLOW_OK;
}
g_mutex_lock (&self->src_mutex);
other_pad = self->src;
if (other_pad)
gst_object_ref (other_pad);
g_mutex_unlock (&self->src_mutex);
if (other_pad) {
GST_LOG_OBJECT (self, "decoded buffer list with length %u, pushing",
gst_buffer_list_length (list));
ret = gst_pad_push_list (other_pad, list);
gst_object_unref (other_pad);
} else {
GST_LOG_OBJECT (self, "dropped buffer list with length %d, not linked",
gst_buffer_list_length (list));
gst_buffer_list_unref (list);
}
return ret;
}
static GstFlowReturn
sink_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstDtlsDec *self = GST_DTLS_DEC (parent);
GstFlowReturn ret = GST_FLOW_OK;
gint size;
GstPad *other_pad;
if (!self->agent) {
gst_buffer_unref (buffer);
return GST_FLOW_OK;
}
GST_DEBUG_OBJECT (self,
"received buffer from %s with length %" G_GSIZE_FORMAT,
self->connection_id, gst_buffer_get_size (buffer));
buffer = gst_buffer_make_writable (buffer);
size = process_buffer (self, buffer);
if (size <= 0) {
gst_buffer_unref (buffer);
return GST_FLOW_OK;
}
g_mutex_lock (&self->src_mutex);
other_pad = self->src;
if (other_pad)
gst_object_ref (other_pad);
g_mutex_unlock (&self->src_mutex);
if (other_pad) {
GST_LOG_OBJECT (self, "decoded buffer with length %d, pushing", size);
ret = gst_pad_push (other_pad, buffer);
gst_object_unref (other_pad);
} else {
GST_LOG_OBJECT (self, "dropped buffer with length %d, not linked", size);
gst_buffer_unref (buffer);
}
return ret;
}
static GHashTable *agent_table = NULL;
G_LOCK_DEFINE_STATIC (agent_table);
static GstDtlsAgent *generated_cert_agent = NULL;
static GstDtlsAgent *
get_agent_by_pem (const gchar * pem)
{
GstDtlsAgent *agent;
if (!pem) {
if (g_once_init_enter (&generated_cert_agent)) {
GstDtlsAgent *new_agent;
new_agent = g_object_new (GST_TYPE_DTLS_AGENT, "certificate",
g_object_new (GST_TYPE_DTLS_CERTIFICATE, NULL), NULL);
GST_DEBUG_OBJECT (generated_cert_agent,
"no agent with generated cert found, creating new");
g_once_init_leave (&generated_cert_agent, new_agent);
} else {
GST_DEBUG_OBJECT (generated_cert_agent,
"using agent with generated cert");
}
agent = generated_cert_agent;
g_object_ref (agent);
} else {
G_LOCK (agent_table);
if (!agent_table) {
agent_table =
g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
}
agent = GST_DTLS_AGENT (g_hash_table_lookup (agent_table, pem));
if (!agent) {
agent = g_object_new (GST_TYPE_DTLS_AGENT,
"certificate", g_object_new (GST_TYPE_DTLS_CERTIFICATE, "pem", pem,
NULL), NULL);
g_object_weak_ref (G_OBJECT (agent), (GWeakNotify) agent_weak_ref_notify,
(gpointer) g_strdup (pem));
g_hash_table_insert (agent_table, g_strdup (pem), agent);
GST_DEBUG_OBJECT (agent, "no agent found, created new");
} else {
g_object_ref (agent);
GST_DEBUG_OBJECT (agent, "agent found");
}
G_UNLOCK (agent_table);
}
return agent;
}
static void
agent_weak_ref_notify (gchar * pem, GstDtlsAgent * agent)
{
G_LOCK (agent_table);
g_hash_table_remove (agent_table, pem);
G_UNLOCK (agent_table);
g_free (pem);
pem = NULL;
}
static GHashTable *connection_table = NULL;
G_LOCK_DEFINE_STATIC (connection_table);
GstDtlsConnection *
gst_dtls_dec_fetch_connection (gchar * id)
{
GstDtlsConnection *connection;
g_return_val_if_fail (id, NULL);
GST_DEBUG ("fetching '%s' from connection table, size is %d",
id, g_hash_table_size (connection_table));
G_LOCK (connection_table);
connection = g_hash_table_lookup (connection_table, id);
if (connection) {
g_object_ref (connection);
g_hash_table_remove (connection_table, id);
} else {
GST_WARNING ("no connection with id '%s' found", id);
}
G_UNLOCK (connection_table);
return connection;
}
static void
create_connection (GstDtlsDec * self, gchar * id)
{
g_return_if_fail (GST_IS_DTLS_DEC (self));
g_return_if_fail (GST_IS_DTLS_AGENT (self->agent));
if (self->connection) {
g_object_unref (self->connection);
self->connection = NULL;
}
G_LOCK (connection_table);
if (!connection_table) {
connection_table =
g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
}
if (g_hash_table_contains (connection_table, id)) {
G_UNLOCK (connection_table);
g_return_if_reached ();
}
self->connection =
g_object_new (GST_TYPE_DTLS_CONNECTION, "agent", self->agent, NULL);
g_object_weak_ref (G_OBJECT (self->connection),
(GWeakNotify) connection_weak_ref_notify, g_strdup (id));
g_hash_table_insert (connection_table, g_strdup (id), self->connection);
G_UNLOCK (connection_table);
}
static void
connection_weak_ref_notify (gchar * id, GstDtlsConnection * connection)
{
G_LOCK (connection_table);
g_hash_table_remove (connection_table, id);
G_UNLOCK (connection_table);
g_free (id);
id = NULL;
}