gstreamer/ext/dtls/gstdtlssrtpdec.c

474 lines
15 KiB
C

/*
* 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 "gstdtlssrtpdec.h"
#include "gstdtlsconnection.h"
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate rtp_src_template =
GST_STATIC_PAD_TEMPLATE ("rtp_src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp;application/x-rtcp")
);
static GstStaticPadTemplate data_src_template =
GST_STATIC_PAD_TEMPLATE ("data_src",
GST_PAD_SRC,
GST_PAD_REQUEST,
GST_STATIC_CAPS_ANY);
GST_DEBUG_CATEGORY_STATIC (gst_dtls_srtp_dec_debug);
#define GST_CAT_DEFAULT gst_dtls_srtp_dec_debug
#define gst_dtls_srtp_dec_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstDtlsSrtpDec, gst_dtls_srtp_dec,
GST_TYPE_DTLS_SRTP_BIN, GST_DEBUG_CATEGORY_INIT (gst_dtls_srtp_dec_debug,
"dtlssrtpdec", 0, "DTLS Decoder"));
enum
{
PROP_0,
PROP_PEM,
PROP_PEER_PEM,
NUM_PROPERTIES
};
static GParamSpec *properties[NUM_PROPERTIES];
#define DEFAULT_PEM NULL
#define DEFAULT_PEER_PEM NULL
static void gst_dtls_srtp_dec_set_property (GObject *, guint prop_id,
const GValue *, GParamSpec *);
static void gst_dtls_srtp_dec_get_property (GObject *, guint prop_id,
GValue *, GParamSpec *);
static GstPad *gst_dtls_srtp_dec_request_new_pad (GstElement *,
GstPadTemplate *, const gchar * name, const GstCaps *);
static GstCaps *on_decoder_request_key (GstElement * srtp_decoder, guint ssrc,
GstDtlsSrtpBin *);
static void on_peer_pem (GstElement * srtp_decoder, GParamSpec * pspec,
GstDtlsSrtpDec * self);
static void gst_dtls_srtp_dec_remove_dtls_element (GstDtlsSrtpBin *);
static GstPadProbeReturn remove_dtls_decoder_probe_callback (GstPad *,
GstPadProbeInfo *, GstElement *);
static GstPadProbeReturn drop_funnel_rtcp_caps (GstPad *, GstPadProbeInfo *,
gpointer);
static void
gst_dtls_srtp_dec_class_init (GstDtlsSrtpDecClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
GstDtlsSrtpBinClass *dtls_srtp_bin_class;
gobject_class = (GObjectClass *) klass;
element_class = (GstElementClass *) klass;
dtls_srtp_bin_class = (GstDtlsSrtpBinClass *) klass;
gobject_class->set_property =
GST_DEBUG_FUNCPTR (gst_dtls_srtp_dec_set_property);
gobject_class->get_property =
GST_DEBUG_FUNCPTR (gst_dtls_srtp_dec_get_property);
element_class->request_new_pad =
GST_DEBUG_FUNCPTR (gst_dtls_srtp_dec_request_new_pad);
dtls_srtp_bin_class->remove_dtls_element =
GST_DEBUG_FUNCPTR (gst_dtls_srtp_dec_remove_dtls_element);
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);
g_object_class_install_properties (gobject_class, NUM_PROPERTIES, properties);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&rtp_src_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&data_src_template));
gst_element_class_set_static_metadata (element_class,
"DTLS-SRTP Decoder",
"Decoder/Network/DTLS/SRTP",
"Decodes SRTP packets with a key received from DTLS",
"Patrik Oldsberg patrik.oldsberg@ericsson.com");
}
static void
gst_dtls_srtp_dec_init (GstDtlsSrtpDec * self)
{
GstElementClass *klass = GST_ELEMENT_GET_CLASS (GST_ELEMENT (self));
GstPadTemplate *templ;
GstPad *target_pad, *ghost_pad, *pad;
gboolean ret;
/*
+--------------------+
+--------------+ .-o| dtlsdec |o-R----------data
| dtls|o-' +--------------------+
sink---o| dtlsdemux |
| srt(c)p|o-. +-----------+ +-----------+
+--------------+ '-o|srtp rtp|o---o|rtp |
| srtpdec | | funnel |o---rt(c)p
o|srtcp rtcp|o---o|rtcp |
+-----------+ +-----------+
*/
self->srtp_dec = gst_element_factory_make ("srtpdec", "srtp-decoder");
if (!self->srtp_dec) {
GST_ERROR_OBJECT (self,
"failed to create srtp_dec, is the srtp plugin registered?");
return;
}
self->dtls_srtp_demux =
gst_element_factory_make ("dtlssrtpdemux", "dtls-srtp-demux");
if (!self->dtls_srtp_demux) {
GST_ERROR_OBJECT (self, "failed to create dtls_srtp_demux");
return;
}
self->bin.dtls_element = gst_element_factory_make ("dtlsdec", "dtls-decoder");
if (!self->bin.dtls_element) {
GST_ERROR_OBJECT (self, "failed to create dtls_dec");
return;
}
self->funnel = gst_element_factory_make ("funnel", "funnel");
if (!self->funnel) {
GST_ERROR_OBJECT (self, "failed to create funnel");
return;
}
gst_bin_add_many (GST_BIN (self),
self->dtls_srtp_demux,
self->bin.dtls_element, self->srtp_dec, self->funnel, NULL);
ret =
gst_element_link_pads (self->dtls_srtp_demux, "dtls_src",
self->bin.dtls_element, NULL);
g_return_if_fail (ret);
ret =
gst_element_link_pads (self->dtls_srtp_demux, "rtp_src", self->srtp_dec,
"rtp_sink");
g_return_if_fail (ret);
ret =
gst_element_link_pads (self->srtp_dec, "rtp_src", self->funnel, "sink_0");
g_return_if_fail (ret);
ret =
gst_element_link_pads (self->srtp_dec, "rtcp_src", self->funnel,
"sink_1");
g_return_if_fail (ret);
pad = gst_element_get_static_pad (self->funnel, "sink_1");
gst_pad_add_probe (pad, GST_PAD_PROBE_TYPE_EVENT_DOWNSTREAM,
drop_funnel_rtcp_caps, NULL, NULL);
gst_object_unref (pad);
templ = gst_element_class_get_pad_template (klass, "rtp_src");
target_pad = gst_element_get_static_pad (self->funnel, "src");
ghost_pad = gst_ghost_pad_new_from_template ("rtp_src", target_pad, templ);
gst_object_unref (target_pad);
g_return_if_fail (ghost_pad);
ret = gst_element_add_pad (GST_ELEMENT (self), ghost_pad);
g_return_if_fail (ret);
templ = gst_element_class_get_pad_template (klass, "sink");
target_pad = gst_element_get_static_pad (self->dtls_srtp_demux, "sink");
ghost_pad = gst_ghost_pad_new_from_template ("sink", target_pad, templ);
gst_object_unref (target_pad);
g_return_if_fail (ghost_pad);
ret = gst_element_add_pad (GST_ELEMENT (self), ghost_pad);
g_return_if_fail (ret);
g_signal_connect (self->srtp_dec, "request-key",
G_CALLBACK (on_decoder_request_key), self);
g_signal_connect (self->bin.dtls_element, "notify::peer-pem",
G_CALLBACK (on_peer_pem), self);
}
static void
gst_dtls_srtp_dec_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstDtlsSrtpDec *self = GST_DTLS_SRTP_DEC (object);
switch (prop_id) {
case PROP_PEM:
if (self->bin.dtls_element) {
g_object_set_property (G_OBJECT (self->bin.dtls_element), "pem", value);
} else {
GST_WARNING_OBJECT (self, "tried to set pem after disabling DTLS");
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
}
}
static void
gst_dtls_srtp_dec_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstDtlsSrtpDec *self = GST_DTLS_SRTP_DEC (object);
switch (prop_id) {
case PROP_PEM:
if (self->bin.dtls_element) {
g_object_get_property (G_OBJECT (self->bin.dtls_element), "pem", value);
} else {
GST_WARNING_OBJECT (self, "tried to get pem after disabling DTLS");
}
break;
case PROP_PEER_PEM:
if (self->bin.dtls_element) {
g_object_get_property (G_OBJECT (self->bin.dtls_element), "peer-pem",
value);
} else {
GST_WARNING_OBJECT (self, "tried to get peer-pem after disabling DTLS");
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
}
}
static GstPad *
gst_dtls_srtp_dec_request_new_pad (GstElement * element,
GstPadTemplate * templ, const gchar * name, const GstCaps * caps)
{
GstDtlsSrtpDec *self = GST_DTLS_SRTP_DEC (element);
GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
GstPad *ghost_pad = NULL;
gboolean ret;
GST_DEBUG_OBJECT (element, "pad requested");
g_return_val_if_fail (self->bin.dtls_element, NULL);
g_return_val_if_fail (!self->bin.key_is_set, NULL);
if (templ == gst_element_class_get_pad_template (klass, "data_src")) {
GstPad *target_pad;
target_pad = gst_element_get_request_pad (self->bin.dtls_element, "src");
ghost_pad = gst_ghost_pad_new_from_template (name, target_pad, templ);
gst_object_unref (target_pad);
g_return_val_if_fail (ghost_pad, NULL);
ret = gst_pad_set_active (ghost_pad, TRUE);
g_return_val_if_fail (ret, NULL);
ret = gst_element_add_pad (element, ghost_pad);
g_return_val_if_fail (ret, NULL);
GST_LOG_OBJECT (self, "added data src pad");
if (caps) {
g_object_set (ghost_pad, "caps", caps, NULL);
}
return ghost_pad;
}
g_return_val_if_reached (NULL);
}
static GstCaps *
on_decoder_request_key (GstElement * srtp_decoder,
guint ssrc, GstDtlsSrtpBin * bin)
{
GstCaps *key_caps;
GstBuffer *key_buffer = NULL;
guint cipher;
guint auth;
if (bin->key_is_set) {
if (bin->key) {
if (bin->srtp_cipher && bin->srtp_auth && bin->srtcp_cipher
&& bin->srtcp_auth) {
GST_DEBUG_OBJECT (bin, "setting srtp key");
return gst_caps_new_simple ("application/x-srtp",
"srtp-key", GST_TYPE_BUFFER, gst_buffer_copy (bin->key),
"srtp-auth", G_TYPE_STRING, bin->srtp_auth,
"srtcp-auth", G_TYPE_STRING, bin->srtcp_auth,
"srtp-cipher", G_TYPE_STRING, bin->srtp_cipher,
"srtcp-cipher", G_TYPE_STRING, bin->srtcp_cipher, NULL);
} else {
GST_WARNING_OBJECT (bin,
"srtp key is set but not all ciphers and auths");
return NULL;
}
}
GST_DEBUG_OBJECT (bin, "setting srtp key to null");
return gst_caps_new_simple ("application/x-srtp",
"srtp-key", GST_TYPE_BUFFER, NULL,
"srtp-auth", G_TYPE_STRING, "null",
"srtcp-auth", G_TYPE_STRING, "null",
"srtp-cipher", G_TYPE_STRING, "null",
"srtcp-cipher", G_TYPE_STRING, "null", NULL);
}
if (bin->dtls_element) {
g_object_get (bin->dtls_element, "decoder-key", &key_buffer, NULL);
}
if (key_buffer) {
g_object_get (bin->dtls_element,
"srtp-cipher", &cipher, "srtp-auth", &auth, NULL);
g_return_val_if_fail (cipher == GST_DTLS_SRTP_CIPHER_AES_128_ICM, NULL);
key_caps = gst_caps_new_simple ("application/x-srtp",
"srtp-key", GST_TYPE_BUFFER, key_buffer,
"srtp-cipher", G_TYPE_STRING, "aes-128-icm",
"srtcp-cipher", G_TYPE_STRING, "aes-128-icm", NULL);
switch (auth) {
case GST_DTLS_SRTP_AUTH_HMAC_SHA1_32:
gst_caps_set_simple (key_caps,
"srtp-auth", G_TYPE_STRING, "hmac-sha1-32",
"srtcp-auth", G_TYPE_STRING, "hmac-sha1-32", NULL);
break;
case GST_DTLS_SRTP_AUTH_HMAC_SHA1_80:
gst_caps_set_simple (key_caps,
"srtp-auth", G_TYPE_STRING, "hmac-sha1-80",
"srtcp-auth", G_TYPE_STRING, "hmac-sha1-80", NULL);
break;
default:
g_return_val_if_reached (NULL);
break;
}
return key_caps;
}
return NULL;
}
static void
on_peer_pem (GstElement * srtp_decoder, GParamSpec * pspec,
GstDtlsSrtpDec * self)
{
g_return_if_fail (self);
g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_PEER_PEM]);
}
static void
gst_dtls_srtp_dec_remove_dtls_element (GstDtlsSrtpBin * bin)
{
GstDtlsSrtpDec *self = GST_DTLS_SRTP_DEC (bin);
GstPad *demux_pad;
gulong id;
if (!bin->dtls_element) {
return;
}
demux_pad = gst_element_get_static_pad (self->dtls_srtp_demux, "dtls_src");
id = gst_pad_add_probe (demux_pad, GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM,
(GstPadProbeCallback) remove_dtls_decoder_probe_callback,
bin->dtls_element, NULL);
g_return_if_fail (id);
bin->dtls_element = NULL;
gst_pad_push_event (demux_pad,
gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM,
gst_structure_new_empty ("dummy")));
gst_object_unref (demux_pad);
}
static GstPadProbeReturn
remove_dtls_decoder_probe_callback (GstPad * pad,
GstPadProbeInfo * info, GstElement * element)
{
gst_pad_remove_probe (pad, GST_PAD_PROBE_INFO_ID (info));
gst_element_set_state (GST_ELEMENT (element), GST_STATE_NULL);
gst_bin_remove (GST_BIN (GST_ELEMENT_PARENT (element)), element);
return GST_PAD_PROBE_OK;
}
static GstPadProbeReturn
drop_funnel_rtcp_caps (GstPad * pad, GstPadProbeInfo * info, gpointer data)
{
/* FIXME: This is needed for setting the proper caps until
* GStreamer supports MIXED caps or another mechanism to
* prevent renegotiation all the time when two different caps
* are going over the same pad
*/
if (GST_EVENT_TYPE (info->data) == GST_EVENT_CAPS) {
GstCaps *caps, *peercaps;
GstStructure *s;
gst_event_parse_caps (GST_EVENT (info->data), &caps);
s = gst_caps_get_structure (caps, 0);
if (gst_structure_has_name (s, "application/x-rtcp")) {
peercaps = gst_pad_query_caps (pad, NULL);
/* If the peer does not accept RTCP, we are linked to
* the RTP sinkpad of rtpbin. In that case we have to
* drop the RTCP caps and assume that we sent RTP caps
* before here, which is very likely but not guaranteed
* if for some reason we receive RTCP before any RTP.
* In that unlikely case we will get event misordering
* warnings later, instead of getting them always as
* happens now.
*/
if (peercaps && !gst_caps_is_subset (caps, peercaps)) {
gst_caps_unref (peercaps);
return GST_PAD_PROBE_DROP;
}
gst_caps_replace (&peercaps, NULL);
}
}
return GST_PAD_PROBE_OK;
}