sctp: dcsctp: Print SCTP packets to logs
When verbose logs are enabled, SCTP packets will be dumped to debug
logs, allowing text2pcap to be used to generate PCAP files.
First start Chrome with verbose logs, and write those to file:
/path/to/chrome --enable-logging=stderr --v=4 2> out.log
Then extract the SCTP_PACKET traces and run text2pcap:
grep SCTP_PACKET out.log > sctp.log
text2pcap -n -i 132 -D -t '%H:%M:%S.' sctp.log sctp.pcapng
You may have to cut away more from the beginning if the debug logs
contain additional timestamps and more, e.g. like:
grep SCTP_PACKET out.log | cut -d ' ' -f 2- > sctp.log
Note that if there are multiple RTCPeerConnection objects created, each
will print out their packets to log, so to filter for a specific one:
grep "SCTP_PACKET DcSctpTransport0" out.log > sctp.log
Bug: webrtc:12614
Change-Id: Ibbceaf33719d09e7606247cb0496ddd827ea58bb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/218200
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33999}
diff --git a/media/sctp/dcsctp_transport.cc b/media/sctp/dcsctp_transport.cc
index 7cbc43f..f0ec69a 100644
--- a/media/sctp/dcsctp_transport.cc
+++ b/media/sctp/dcsctp_transport.cc
@@ -19,10 +19,13 @@
#include "absl/types/optional.h"
#include "api/array_view.h"
#include "media/base/media_channel.h"
+#include "net/dcsctp/public/packet_observer.h"
#include "net/dcsctp/public/types.h"
#include "net/dcsctp/socket/dcsctp_socket.h"
#include "p2p/base/packet_transport_internal.h"
#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/strings/string_builder.h"
#include "rtc_base/thread.h"
#include "rtc_base/trace_event.h"
#include "system_wrappers/include/clock.h"
@@ -76,6 +79,45 @@
webrtc_ppid == WebrtcPPID::kBinaryEmpty;
}
+// Print outs all sent and received packets to the logs, at LS_VERBOSE severity.
+class TextPcapPacketObserver : public dcsctp::PacketObserver {
+ public:
+ explicit TextPcapPacketObserver(absl::string_view name) : name_(name) {}
+
+ void OnSentPacket(dcsctp::TimeMs now, rtc::ArrayView<const uint8_t> payload) {
+ PrintPacket("O ", now, payload);
+ }
+
+ void OnReceivedPacket(dcsctp::TimeMs now,
+ rtc::ArrayView<const uint8_t> payload) {
+ PrintPacket("I ", now, payload);
+ }
+
+ private:
+ void PrintPacket(absl::string_view prefix,
+ dcsctp::TimeMs now,
+ rtc::ArrayView<const uint8_t> payload) {
+ rtc::StringBuilder s;
+ s << prefix;
+ int64_t remaining = *now % (24 * 60 * 60 * 1000);
+ int hours = remaining / (60 * 60 * 1000);
+ remaining = remaining % (60 * 60 * 1000);
+ int minutes = remaining / (60 * 1000);
+ remaining = remaining % (60 * 1000);
+ int seconds = remaining / 1000;
+ int ms = remaining % 1000;
+ s.AppendFormat("%02d:%02d:%02d.%03d", hours, minutes, seconds, ms);
+ s << " 0000";
+ for (uint8_t byte : payload) {
+ s.AppendFormat(" %02x", byte);
+ }
+ s << " # SCTP_PACKET " << name_;
+ RTC_LOG(LS_VERBOSE) << s.str();
+ }
+
+ const std::string name_;
+};
+
} // namespace
DcSctpTransport::DcSctpTransport(rtc::Thread* network_thread,
@@ -130,8 +172,13 @@
options.remote_port = remote_sctp_port;
options.max_message_size = max_message_size;
- socket_ = std::make_unique<dcsctp::DcSctpSocket>(debug_name_, *this,
- nullptr, options);
+ std::unique_ptr<dcsctp::PacketObserver> packet_observer;
+ if (RTC_LOG_CHECK_LEVEL(LS_VERBOSE)) {
+ packet_observer = std::make_unique<TextPcapPacketObserver>(debug_name_);
+ }
+
+ socket_ = std::make_unique<dcsctp::DcSctpSocket>(
+ debug_name_, *this, std::move(packet_observer), options);
} else {
if (local_sctp_port != socket_->options().local_port ||
remote_sctp_port != socket_->options().remote_port) {
