gstreamer/gst/pcapparse/gstpcapparse.c

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/*
* Copyright 2007 Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-pcapparse
* @title: pcapparse
*
* Extracts payloads from Ethernet-encapsulated IP packets.
* Use #GstPcapParse:src-ip, #GstPcapParse:dst-ip,
* #GstPcapParse:src-port and #GstPcapParse:dst-port to restrict which packets
* should be included.
*
* The supported data format is the classical
* [libpcap file format](https://wiki.wireshark.org/Development/LibpcapFileFormat)
*
* ## Example pipelines
* |[
* gst-launch-1.0 filesrc location=h264crasher.pcap ! pcapparse ! rtph264depay
* ! ffdec_h264 ! fakesink
* ]| Read from a pcap dump file using filesrc, extract the raw UDP packets,
* depayload and decode them.
*
*/
/* TODO:
* - Implement support for timestamping the buffers.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "gstpcapparse.h"
#include <string.h>
#ifndef G_OS_WIN32
#include <arpa/inet.h>
#include <netinet/in.h>
#include <string.h>
#else
#include <winsock2.h>
#endif
const guint GST_PCAPPARSE_MAGIC_MILLISECOND_NO_SWAP_ENDIAN = 0xa1b2c3d4;
const guint GST_PCAPPARSE_MAGIC_NANOSECOND_NO_SWAP_ENDIAN = 0xa1b23c4d;
const guint GST_PCAPPARSE_MAGIC_MILLISECOND_SWAP_ENDIAN = 0xd4c3b2a1;
const guint GST_PCAPPARSE_MAGIC_NANOSECOND_SWAP_ENDIAN = 0x4d3cb2a1;
enum
{
PROP_0,
PROP_SRC_IP,
PROP_DST_IP,
PROP_SRC_PORT,
PROP_DST_PORT,
PROP_CAPS,
PROP_TS_OFFSET
};
GST_DEBUG_CATEGORY_STATIC (gst_pcap_parse_debug);
#define GST_CAT_DEFAULT gst_pcap_parse_debug
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("raw/x-pcap"));
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void gst_pcap_parse_finalize (GObject * object);
static void gst_pcap_parse_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_pcap_parse_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static GstStateChangeReturn
gst_pcap_parse_change_state (GstElement * element, GstStateChange transition);
static void gst_pcap_parse_reset (GstPcapParse * self);
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static GstFlowReturn gst_pcap_parse_chain (GstPad * pad,
GstObject * parent, GstBuffer * buffer);
static gboolean gst_pcap_sink_event (GstPad * pad,
GstObject * parent, GstEvent * event);
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#define parent_class gst_pcap_parse_parent_class
G_DEFINE_TYPE (GstPcapParse, gst_pcap_parse, GST_TYPE_ELEMENT);
static void
gst_pcap_parse_class_init (GstPcapParseClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
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GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gobject_class->finalize = gst_pcap_parse_finalize;
gobject_class->get_property = gst_pcap_parse_get_property;
gobject_class->set_property = gst_pcap_parse_set_property;
g_object_class_install_property (gobject_class,
PROP_SRC_IP, g_param_spec_string ("src-ip", "Source IP",
"Source IP to restrict to", "",
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class,
PROP_DST_IP, g_param_spec_string ("dst-ip", "Destination IP",
"Destination IP to restrict to", "",
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class,
PROP_SRC_PORT, g_param_spec_int ("src-port", "Source port",
"Source port to restrict to", -1, G_MAXUINT16, -1,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class,
PROP_DST_PORT, g_param_spec_int ("dst-port", "Destination port",
"Destination port to restrict to", -1, G_MAXUINT16, -1,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_CAPS,
g_param_spec_boxed ("caps", "Caps",
"The caps of the source pad", GST_TYPE_CAPS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_TS_OFFSET,
g_param_spec_int64 ("ts-offset", "Timestamp Offset",
"Relative timestamp offset (ns) to apply (-1 = use absolute packet time)",
-1, G_MAXINT64, -1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gst_element_class_add_static_pad_template (element_class, &sink_template);
gst_element_class_add_static_pad_template (element_class, &src_template);
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element_class->change_state = gst_pcap_parse_change_state;
gst_element_class_set_static_metadata (element_class, "PCapParse",
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"Raw/Parser",
"Parses a raw pcap stream",
"Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>");
GST_DEBUG_CATEGORY_INIT (gst_pcap_parse_debug, "pcapparse", 0, "pcap parser");
}
static void
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gst_pcap_parse_init (GstPcapParse * self)
{
self->sink_pad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (self->sink_pad,
GST_DEBUG_FUNCPTR (gst_pcap_parse_chain));
gst_pad_use_fixed_caps (self->sink_pad);
gst_pad_set_event_function (self->sink_pad,
GST_DEBUG_FUNCPTR (gst_pcap_sink_event));
gst_element_add_pad (GST_ELEMENT (self), self->sink_pad);
self->src_pad = gst_pad_new_from_static_template (&src_template, "src");
gst_pad_use_fixed_caps (self->src_pad);
gst_element_add_pad (GST_ELEMENT (self), self->src_pad);
self->src_ip = -1;
self->dst_ip = -1;
self->src_port = -1;
self->dst_port = -1;
self->offset = -1;
self->adapter = gst_adapter_new ();
gst_pcap_parse_reset (self);
}
static void
gst_pcap_parse_finalize (GObject * object)
{
GstPcapParse *self = GST_PCAP_PARSE (object);
g_object_unref (self->adapter);
if (self->caps)
gst_caps_unref (self->caps);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static const gchar *
get_ip_address_as_string (gint64 ip_addr)
{
if (ip_addr >= 0) {
struct in_addr addr;
addr.s_addr = ip_addr;
return inet_ntoa (addr);
} else {
return "";
}
}
static void
set_ip_address_from_string (gint64 * ip_addr, const gchar * ip_str)
{
if (ip_str[0] != '\0') {
gulong addr = inet_addr (ip_str);
if (addr != INADDR_NONE)
*ip_addr = addr;
} else {
*ip_addr = -1;
}
}
static void
gst_pcap_parse_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstPcapParse *self = GST_PCAP_PARSE (object);
switch (prop_id) {
case PROP_SRC_IP:
g_value_set_string (value, get_ip_address_as_string (self->src_ip));
break;
case PROP_DST_IP:
g_value_set_string (value, get_ip_address_as_string (self->dst_ip));
break;
case PROP_SRC_PORT:
g_value_set_int (value, self->src_port);
break;
case PROP_DST_PORT:
g_value_set_int (value, self->dst_port);
break;
case PROP_CAPS:
gst_value_set_caps (value, self->caps);
break;
case PROP_TS_OFFSET:
g_value_set_int64 (value, self->offset);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_pcap_parse_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstPcapParse *self = GST_PCAP_PARSE (object);
switch (prop_id) {
case PROP_SRC_IP:
set_ip_address_from_string (&self->src_ip, g_value_get_string (value));
break;
case PROP_DST_IP:
set_ip_address_from_string (&self->dst_ip, g_value_get_string (value));
break;
case PROP_SRC_PORT:
self->src_port = g_value_get_int (value);
break;
case PROP_DST_PORT:
self->dst_port = g_value_get_int (value);
break;
case PROP_CAPS:
{
const GstCaps *new_caps_val;
GstCaps *new_caps, *old_caps;
new_caps_val = gst_value_get_caps (value);
if (new_caps_val == NULL) {
new_caps = gst_caps_new_any ();
} else {
new_caps = gst_caps_copy (new_caps_val);
}
old_caps = self->caps;
self->caps = new_caps;
if (old_caps)
gst_caps_unref (old_caps);
gst_pad_set_caps (self->src_pad, new_caps);
break;
}
case PROP_TS_OFFSET:
self->offset = g_value_get_int64 (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_pcap_parse_reset (GstPcapParse * self)
{
self->initialized = FALSE;
self->swap_endian = FALSE;
self->nanosecond_timestamp = FALSE;
self->cur_packet_size = -1;
self->cur_ts = GST_CLOCK_TIME_NONE;
self->base_ts = GST_CLOCK_TIME_NONE;
self->newsegment_sent = FALSE;
self->first_packet = TRUE;
gst_adapter_clear (self->adapter);
}
static guint32
gst_pcap_parse_read_uint32 (GstPcapParse * self, const guint8 * p)
{
guint32 val = *((guint32 *) p);
if (self->swap_endian) {
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
return GUINT32_FROM_BE (val);
#else
return GUINT32_FROM_LE (val);
#endif
} else {
return val;
}
}
#define ETH_MAC_ADDRESSES_LEN 12
#define ETH_HEADER_LEN 14
#define ETH_VLAN_HEADER_LEN 4
#define SLL_HEADER_LEN 16
#define IP_HEADER_MIN_LEN 20
#define UDP_HEADER_LEN 8
#define IP_PROTO_UDP 17
#define IP_PROTO_TCP 6
static gboolean
gst_pcap_parse_scan_frame (GstPcapParse * self,
const guint8 * buf,
gint buf_size, const guint8 ** payload, gint * payload_size)
{
const guint8 *buf_ip = 0;
const guint8 *buf_proto;
guint16 eth_type;
guint8 b;
guint8 ip_header_size;
guint8 flags;
guint16 fragment_offset;
guint8 ip_protocol;
guint32 ip_src_addr;
guint32 ip_dst_addr;
guint16 src_port;
guint16 dst_port;
guint16 len;
guint16 ip_packet_len;
switch (self->linktype) {
case LINKTYPE_ETHER:
if (buf_size < ETH_HEADER_LEN + IP_HEADER_MIN_LEN + UDP_HEADER_LEN)
return FALSE;
eth_type = GUINT16_FROM_BE (*((guint16 *) (buf + ETH_MAC_ADDRESSES_LEN)));
/* check for vlan 802.1q header (4 bytes, with first two bytes equal to 0x8100) */
if (eth_type == 0x8100) {
if (buf_size <
ETH_HEADER_LEN + ETH_VLAN_HEADER_LEN + IP_HEADER_MIN_LEN +
UDP_HEADER_LEN)
return FALSE;
eth_type =
GUINT16_FROM_BE (*((guint16 *) (buf + ETH_MAC_ADDRESSES_LEN +
ETH_VLAN_HEADER_LEN)));
buf_ip = buf + ETH_HEADER_LEN + ETH_VLAN_HEADER_LEN;
} else {
buf_ip = buf + ETH_HEADER_LEN;
}
break;
case LINKTYPE_SLL:
if (buf_size < SLL_HEADER_LEN + IP_HEADER_MIN_LEN + UDP_HEADER_LEN)
return FALSE;
eth_type = GUINT16_FROM_BE (*((guint16 *) (buf + 14)));
buf_ip = buf + SLL_HEADER_LEN;
break;
case LINKTYPE_RAW:
if (buf_size < IP_HEADER_MIN_LEN + UDP_HEADER_LEN)
return FALSE;
eth_type = 0x800; /* This is fine since IPv4/IPv6 is parse elsewhere */
buf_ip = buf;
break;
default:
return FALSE;
}
if (eth_type != 0x800) {
GST_ERROR_OBJECT (self,
"Link type %d: Ethernet type %d is not supported; only type 0x800",
(gint) self->linktype, (gint) eth_type);
return FALSE;
}
b = *buf_ip;
/* Check that the packet is IPv4 */
if (((b >> 4) & 0x0f) != 4)
return FALSE;
ip_header_size = (b & 0x0f) * 4;
if (buf_ip + ip_header_size > buf + buf_size)
return FALSE;
flags = buf_ip[6] >> 5;
fragment_offset =
(GUINT16_FROM_BE (*((guint16 *) (buf_ip + 6))) & 0x1fff) * 8;
if (flags & 0x1 || fragment_offset > 0) {
GST_ERROR_OBJECT (self, "Fragmented packets are not supported");
return FALSE;
}
ip_protocol = *(buf_ip + 9);
GST_LOG_OBJECT (self, "ip proto %d", (gint) ip_protocol);
if (ip_protocol != IP_PROTO_UDP && ip_protocol != IP_PROTO_TCP)
return FALSE;
/* ip info */
ip_src_addr = *((guint32 *) (buf_ip + 12));
ip_dst_addr = *((guint32 *) (buf_ip + 16));
buf_proto = buf_ip + ip_header_size;
ip_packet_len = GUINT16_FROM_BE (*(guint16 *) (buf_ip + 2));
/* ok for tcp and udp */
src_port = GUINT16_FROM_BE (*((guint16 *) (buf_proto + 0)));
dst_port = GUINT16_FROM_BE (*((guint16 *) (buf_proto + 2)));
/* extract some params and data according to protocol */
if (ip_protocol == IP_PROTO_UDP) {
len = GUINT16_FROM_BE (*((guint16 *) (buf_proto + 4)));
if (len < UDP_HEADER_LEN || buf_proto + len > buf + buf_size)
return FALSE;
*payload = buf_proto + UDP_HEADER_LEN;
*payload_size = len - UDP_HEADER_LEN;
} else {
if (buf_proto + 12 >= buf + buf_size)
return FALSE;
len = (buf_proto[12] >> 4) * 4;
if (buf_proto + len > buf + buf_size)
return FALSE;
/* all remaining data following tcp header is payload */
*payload = buf_proto + len;
*payload_size = ip_packet_len - ip_header_size - len;
}
/* but still filter as configured */
if (self->src_ip >= 0 && ip_src_addr != self->src_ip)
return FALSE;
if (self->dst_ip >= 0 && ip_dst_addr != self->dst_ip)
return FALSE;
if (self->src_port >= 0 && src_port != self->src_port)
return FALSE;
if (self->dst_port >= 0 && dst_port != self->dst_port)
return FALSE;
return TRUE;
}
static GstFlowReturn
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gst_pcap_parse_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
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GstPcapParse *self = GST_PCAP_PARSE (parent);
GstFlowReturn ret = GST_FLOW_OK;
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GstBufferList *list = NULL;
gst_adapter_push (self->adapter, buffer);
while (ret == GST_FLOW_OK) {
gint avail;
const guint8 *data;
avail = gst_adapter_available (self->adapter);
if (self->initialized) {
if (self->cur_packet_size >= 0) {
/* Parse the Packet Data */
if (avail < self->cur_packet_size)
break;
if (self->cur_packet_size > 0) {
const guint8 *payload_data;
gint payload_size;
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data = gst_adapter_map (self->adapter, self->cur_packet_size);
GST_LOG_OBJECT (self, "examining packet size %" G_GINT64_FORMAT,
self->cur_packet_size);
if (gst_pcap_parse_scan_frame (self, data, self->cur_packet_size,
&payload_data, &payload_size)) {
GstBuffer *out_buf;
guintptr offset = payload_data - data;
gst_adapter_unmap (self->adapter);
gst_adapter_flush (self->adapter, offset);
/* we don't use _take_buffer_fast() on purpose here, we need a
* buffer with a single memory, since the RTP depayloaders expect
* the complete RTP header to be in the first memory if there are
* multiple ones and we can't guarantee that with _fast() */
if (payload_size > 0) {
out_buf = gst_adapter_take_buffer (self->adapter, payload_size);
} else {
out_buf = gst_buffer_new ();
}
/* only first packet should have DISCONT flag */
if (G_LIKELY (!self->first_packet)) {
GST_BUFFER_FLAG_UNSET (out_buf, GST_BUFFER_FLAG_DISCONT);
} else {
GST_BUFFER_FLAG_SET (out_buf, GST_BUFFER_FLAG_DISCONT);
self->first_packet = FALSE;
}
gst_adapter_flush (self->adapter,
self->cur_packet_size - offset - payload_size);
if (GST_CLOCK_TIME_IS_VALID (self->cur_ts)) {
if (!GST_CLOCK_TIME_IS_VALID (self->base_ts))
self->base_ts = self->cur_ts;
if (self->offset >= 0) {
self->cur_ts -= self->base_ts;
self->cur_ts += self->offset;
}
}
GST_BUFFER_TIMESTAMP (out_buf) = self->cur_ts;
if (list == NULL)
list = gst_buffer_list_new ();
gst_buffer_list_add (list, out_buf);
} else {
gst_adapter_unmap (self->adapter);
gst_adapter_flush (self->adapter, self->cur_packet_size);
}
}
self->cur_packet_size = -1;
} else {
/* Parse the Record (Packet) Header */
guint32 ts_sec;
guint32 ts_usec;
guint32 incl_len;
/* sizeof(pcaprec_hdr_t) == 16 */
if (avail < 16)
break;
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data = gst_adapter_map (self->adapter, 16);
ts_sec = gst_pcap_parse_read_uint32 (self, data + 0);
ts_usec = gst_pcap_parse_read_uint32 (self, data + 4);
incl_len = gst_pcap_parse_read_uint32 (self, data + 8);
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/* orig_len = gst_pcap_parse_read_uint32 (self, data + 12); */
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gst_adapter_unmap (self->adapter);
gst_adapter_flush (self->adapter, 16);
self->cur_ts =
ts_sec * GST_SECOND +
ts_usec * (self->nanosecond_timestamp ? 1 : GST_USECOND);
self->cur_packet_size = incl_len;
}
} else {
/* Parse the Global Header */
guint32 magic;
guint32 linktype;
guint16 major_version;
/* sizeof(pcap_hdr_t) == 24 */
if (avail < 24)
break;
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data = gst_adapter_map (self->adapter, 24);
magic = *((guint32 *) data);
major_version = *((guint16 *) (data + 4));
linktype = *((guint32 *) (data + 20));
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gst_adapter_unmap (self->adapter);
if (magic == GST_PCAPPARSE_MAGIC_MILLISECOND_NO_SWAP_ENDIAN ||
magic == GST_PCAPPARSE_MAGIC_NANOSECOND_NO_SWAP_ENDIAN) {
self->swap_endian = FALSE;
if (magic == GST_PCAPPARSE_MAGIC_NANOSECOND_NO_SWAP_ENDIAN)
self->nanosecond_timestamp = TRUE;
} else if (magic == GST_PCAPPARSE_MAGIC_MILLISECOND_SWAP_ENDIAN ||
magic == GST_PCAPPARSE_MAGIC_NANOSECOND_SWAP_ENDIAN) {
self->swap_endian = TRUE;
if (magic == GST_PCAPPARSE_MAGIC_NANOSECOND_SWAP_ENDIAN)
self->nanosecond_timestamp = TRUE;
major_version = GUINT16_SWAP_LE_BE (major_version);
linktype = GUINT32_SWAP_LE_BE (linktype);
} else {
GST_ELEMENT_ERROR (self, STREAM, WRONG_TYPE, (NULL),
("File is not a libpcap file, magic is %X", magic));
ret = GST_FLOW_ERROR;
goto out;
}
if (major_version != 2) {
GST_ELEMENT_ERROR (self, STREAM, WRONG_TYPE, (NULL),
("File is not a libpcap major version 2, but %u", major_version));
ret = GST_FLOW_ERROR;
goto out;
}
if (linktype != LINKTYPE_ETHER && linktype != LINKTYPE_SLL &&
linktype != LINKTYPE_RAW) {
GST_ELEMENT_ERROR (self, STREAM, WRONG_TYPE, (NULL),
("Only dumps of type Ethernet, raw IP or Linux Cooked (SLL) "
"understood; type %d unknown", linktype));
ret = GST_FLOW_ERROR;
goto out;
}
GST_DEBUG_OBJECT (self, "linktype %u", linktype);
self->linktype = linktype;
gst_adapter_flush (self->adapter, 24);
self->initialized = TRUE;
}
}
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if (list) {
if (!self->newsegment_sent && GST_CLOCK_TIME_IS_VALID (self->cur_ts)) {
GstSegment segment;
if (self->caps)
gst_pad_set_caps (self->src_pad, self->caps);
gst_segment_init (&segment, GST_FORMAT_TIME);
segment.start = self->base_ts;
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gst_pad_push_event (self->src_pad, gst_event_new_segment (&segment));
self->newsegment_sent = TRUE;
}
ret = gst_pad_push_list (self->src_pad, list);
list = NULL;
}
out:
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if (list)
gst_buffer_list_unref (list);
return ret;
}
static gboolean
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gst_pcap_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
gboolean ret = TRUE;
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GstPcapParse *self = GST_PCAP_PARSE (parent);
switch (GST_EVENT_TYPE (event)) {
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case GST_EVENT_SEGMENT:
/* Drop it, we'll replace it with our own */
gst_event_unref (event);
break;
case GST_EVENT_FLUSH_STOP:
gst_pcap_parse_reset (self);
/* Push event down the pipeline so that other elements stop flushing */
/* fall through */
default:
ret = gst_pad_push_event (self->src_pad, event);
break;
}
return ret;
}
static GstStateChangeReturn
gst_pcap_parse_change_state (GstElement * element, GstStateChange transition)
{
GstPcapParse *self = GST_PCAP_PARSE (element);
GstStateChangeReturn ret;
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_pcap_parse_reset (self);
break;
default:
break;
}
return ret;
}