dcsctp: Expose negotiated stream counts
To allow the transport to be able to know which ranges of
stream identifiers it can use, the negotiated incoming/inbound
and outgoing/outbound stream counts will be exposed. They are
added to Metrics, and guaranteed to be available from within
the OnConnected callback.
In this CL, dcSCTP will not validate that the client is sending
on a stream that is within the negotiated bounds. That will be
done as a follow-up CL.
Bug: webrtc:14277
Change-Id: Ic764e5f93f53d55633ee547df86246022f4097cf
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/272321
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37876}
diff --git a/net/dcsctp/public/dcsctp_socket.h b/net/dcsctp/public/dcsctp_socket.h
index 8506397..2df6a2c 100644
--- a/net/dcsctp/public/dcsctp_socket.h
+++ b/net/dcsctp/public/dcsctp_socket.h
@@ -244,6 +244,13 @@
// Indicates if RFC8260 User Message Interleaving has been negotiated by both
// peers.
bool uses_message_interleaving = false;
+
+ // The number of negotiated incoming and outgoing streams, which is configured
+ // locally as `DcSctpOptions::announced_maximum_incoming_streams` and
+ // `DcSctpOptions::announced_maximum_outgoing_streams`, and which will be
+ // signaled by the peer during connection.
+ uint16_t negotiated_maximum_incoming_streams = 0;
+ uint16_t negotiated_maximum_outgoing_streams = 0;
};
// Callbacks that the DcSctpSocket will call synchronously to the owning
diff --git a/net/dcsctp/socket/capabilities.h b/net/dcsctp/socket/capabilities.h
index c6d3692..fa3be37 100644
--- a/net/dcsctp/socket/capabilities.h
+++ b/net/dcsctp/socket/capabilities.h
@@ -10,6 +10,7 @@
#ifndef NET_DCSCTP_SOCKET_CAPABILITIES_H_
#define NET_DCSCTP_SOCKET_CAPABILITIES_H_
+#include <cstdint>
namespace dcsctp {
// Indicates what the association supports, meaning that both parties
// support it and that feature can be used.
@@ -20,6 +21,9 @@
bool message_interleaving = false;
// RFC6525 Stream Reconfiguration
bool reconfig = false;
+ // Negotiated maximum incoming and outgoing stream count.
+ uint16_t negotiated_maximum_incoming_streams = 0;
+ uint16_t negotiated_maximum_outgoing_streams = 0;
};
} // namespace dcsctp
diff --git a/net/dcsctp/socket/dcsctp_socket.cc b/net/dcsctp/socket/dcsctp_socket.cc
index 5383819..78c88c3 100644
--- a/net/dcsctp/socket/dcsctp_socket.cc
+++ b/net/dcsctp/socket/dcsctp_socket.cc
@@ -90,8 +90,10 @@
constexpr uint32_t kMinInitialTsn = 0;
constexpr uint32_t kMaxInitialTsn = std::numeric_limits<uint32_t>::max();
-Capabilities GetCapabilities(const DcSctpOptions& options,
- const Parameters& parameters) {
+Capabilities ComputeCapabilities(const DcSctpOptions& options,
+ uint16_t peer_nbr_outbound_streams,
+ uint16_t peer_nbr_inbound_streams,
+ const Parameters& parameters) {
Capabilities capabilities;
absl::optional<SupportedExtensionsParameter> supported_extensions =
parameters.get<SupportedExtensionsParameter>();
@@ -114,6 +116,12 @@
supported_extensions->supports(ReConfigChunk::kType)) {
capabilities.reconfig = true;
}
+
+ capabilities.negotiated_maximum_incoming_streams = std::min(
+ options.announced_maximum_incoming_streams, peer_nbr_outbound_streams);
+ capabilities.negotiated_maximum_outgoing_streams = std::min(
+ options.announced_maximum_outgoing_streams, peer_nbr_inbound_streams);
+
return capabilities;
}
@@ -312,6 +320,10 @@
size_t a_rwnd,
TieTag tie_tag) {
metrics_.uses_message_interleaving = capabilities.message_interleaving;
+ metrics_.negotiated_maximum_incoming_streams =
+ capabilities.negotiated_maximum_incoming_streams;
+ metrics_.negotiated_maximum_outgoing_streams =
+ capabilities.negotiated_maximum_outgoing_streams;
tcb_ = std::make_unique<TransmissionControlBlock>(
timer_manager_, log_prefix_, options_, capabilities, callbacks_,
send_queue_, my_verification_tag, my_initial_tsn, peer_verification_tag,
@@ -339,6 +351,10 @@
capabilities.message_interleaving =
state.capabilities.message_interleaving;
capabilities.reconfig = state.capabilities.reconfig;
+ capabilities.negotiated_maximum_incoming_streams =
+ state.capabilities.negotiated_maximum_incoming_streams;
+ capabilities.negotiated_maximum_outgoing_streams =
+ state.capabilities.negotiated_maximum_outgoing_streams;
send_queue_.RestoreFromState(state);
@@ -578,6 +594,10 @@
(send_queue_.total_buffered_amount() + packet_payload_size - 1) /
packet_payload_size;
metrics.peer_rwnd_bytes = tcb_->retransmission_queue().rwnd();
+ metrics.negotiated_maximum_incoming_streams =
+ tcb_->capabilities().negotiated_maximum_incoming_streams;
+ metrics.negotiated_maximum_incoming_streams =
+ tcb_->capabilities().negotiated_maximum_incoming_streams;
return metrics;
}
@@ -1172,7 +1192,9 @@
*connect_params_.verification_tag, *connect_params_.initial_tsn,
*chunk->initiate_tag(), *chunk->initial_tsn());
- Capabilities capabilities = GetCapabilities(options_, chunk->parameters());
+ Capabilities capabilities =
+ ComputeCapabilities(options_, chunk->nbr_outbound_streams(),
+ chunk->nbr_inbound_streams(), chunk->parameters());
SctpPacket::Builder b(chunk->initiate_tag(), options_);
Parameters::Builder params_builder =
@@ -1221,7 +1243,9 @@
"InitAck chunk doesn't contain a cookie");
return;
}
- Capabilities capabilities = GetCapabilities(options_, chunk->parameters());
+ Capabilities capabilities =
+ ComputeCapabilities(options_, chunk->nbr_outbound_streams(),
+ chunk->nbr_inbound_streams(), chunk->parameters());
t1_init_->Stop();
metrics_.peer_implementation = DeterminePeerImplementation(cookie->data());
diff --git a/net/dcsctp/socket/dcsctp_socket_test.cc b/net/dcsctp/socket/dcsctp_socket_test.cc
index d1e2d90..ab854da 100644
--- a/net/dcsctp/socket/dcsctp_socket_test.cc
+++ b/net/dcsctp/socket/dcsctp_socket_test.cc
@@ -2668,5 +2668,29 @@
EXPECT_THAT(GetReceivedMessagePpids(z), IsEmpty());
}
+TEST_P(DcSctpSocketParametrizedTest, ExposesTheNumberOfNegotiatedStreams) {
+ DcSctpOptions options_a = {
+ .announced_maximum_incoming_streams = 12,
+ .announced_maximum_outgoing_streams = 45,
+ };
+ SocketUnderTest a("A", options_a);
+
+ DcSctpOptions options_z = {
+ .announced_maximum_incoming_streams = 23,
+ .announced_maximum_outgoing_streams = 34,
+ };
+ auto z = std::make_unique<SocketUnderTest>("Z", options_z);
+
+ ConnectSockets(a, *z);
+ z = MaybeHandoverSocket(std::move(z));
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(Metrics metrics_a, a.socket.GetMetrics());
+ EXPECT_EQ(metrics_a.negotiated_maximum_incoming_streams, 12);
+ EXPECT_EQ(metrics_a.negotiated_maximum_outgoing_streams, 23);
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(Metrics metrics_z, z->socket.GetMetrics());
+ EXPECT_EQ(metrics_z.negotiated_maximum_incoming_streams, 23);
+ EXPECT_EQ(metrics_z.negotiated_maximum_outgoing_streams, 12);
+}
} // namespace
} // namespace dcsctp
diff --git a/net/dcsctp/socket/state_cookie.cc b/net/dcsctp/socket/state_cookie.cc
index 7d04cbb..86be77a 100644
--- a/net/dcsctp/socket/state_cookie.cc
+++ b/net/dcsctp/socket/state_cookie.cc
@@ -40,6 +40,8 @@
buffer.Store8<28>(capabilities_.partial_reliability);
buffer.Store8<29>(capabilities_.message_interleaving);
buffer.Store8<30>(capabilities_.reconfig);
+ buffer.Store16<32>(capabilities_.negotiated_maximum_incoming_streams);
+ buffer.Store16<34>(capabilities_.negotiated_maximum_outgoing_streams);
return cookie;
}
@@ -70,6 +72,8 @@
capabilities.partial_reliability = buffer.Load8<28>() != 0;
capabilities.message_interleaving = buffer.Load8<29>() != 0;
capabilities.reconfig = buffer.Load8<30>() != 0;
+ capabilities.negotiated_maximum_incoming_streams = buffer.Load16<32>();
+ capabilities.negotiated_maximum_outgoing_streams = buffer.Load16<34>();
return StateCookie(verification_tag, initial_tsn, a_rwnd, tie_tag,
capabilities);
diff --git a/net/dcsctp/socket/state_cookie.h b/net/dcsctp/socket/state_cookie.h
index df4b801..a26dbf8 100644
--- a/net/dcsctp/socket/state_cookie.h
+++ b/net/dcsctp/socket/state_cookie.h
@@ -27,7 +27,7 @@
// Do not trust anything in it; no pointers or anything like that.
class StateCookie {
public:
- static constexpr size_t kCookieSize = 31;
+ static constexpr size_t kCookieSize = 36;
StateCookie(VerificationTag initiate_tag,
TSN initial_tsn,
diff --git a/net/dcsctp/socket/state_cookie_test.cc b/net/dcsctp/socket/state_cookie_test.cc
index 870620b..7d8e133 100644
--- a/net/dcsctp/socket/state_cookie_test.cc
+++ b/net/dcsctp/socket/state_cookie_test.cc
@@ -18,9 +18,11 @@
using ::testing::SizeIs;
TEST(StateCookieTest, SerializeAndDeserialize) {
- Capabilities capabilities = {/*partial_reliability=*/true,
- /*message_interleaving=*/false,
- /*reconfig=*/true};
+ Capabilities capabilities = {.partial_reliability = true,
+ .message_interleaving = false,
+ .reconfig = true,
+ .negotiated_maximum_incoming_streams = 123,
+ .negotiated_maximum_outgoing_streams = 234};
StateCookie cookie(VerificationTag(123), TSN(456),
/*a_rwnd=*/789, TieTag(101112), capabilities);
std::vector<uint8_t> serialized = cookie.Serialize();
@@ -34,12 +36,16 @@
EXPECT_TRUE(deserialized.capabilities().partial_reliability);
EXPECT_FALSE(deserialized.capabilities().message_interleaving);
EXPECT_TRUE(deserialized.capabilities().reconfig);
+ EXPECT_EQ(deserialized.capabilities().negotiated_maximum_incoming_streams,
+ 123);
+ EXPECT_EQ(deserialized.capabilities().negotiated_maximum_outgoing_streams,
+ 234);
}
TEST(StateCookieTest, ValidateMagicValue) {
- Capabilities capabilities = {/*partial_reliability=*/true,
- /*message_interleaving=*/false,
- /*reconfig=*/true};
+ Capabilities capabilities = {.partial_reliability = true,
+ .message_interleaving = false,
+ .reconfig = true};
StateCookie cookie(VerificationTag(123), TSN(456),
/*a_rwnd=*/789, TieTag(101112), capabilities);
std::vector<uint8_t> serialized = cookie.Serialize();
diff --git a/net/dcsctp/socket/transmission_control_block.cc b/net/dcsctp/socket/transmission_control_block.cc
index d769e26..1dcf394 100644
--- a/net/dcsctp/socket/transmission_control_block.cc
+++ b/net/dcsctp/socket/transmission_control_block.cc
@@ -274,6 +274,8 @@
if (capabilities_.reconfig) {
sb << "Reconfig,";
}
+ sb << " max_in=" << capabilities_.negotiated_maximum_incoming_streams;
+ sb << " max_out=" << capabilities_.negotiated_maximum_outgoing_streams;
return sb.Release();
}
@@ -292,6 +294,10 @@
state.capabilities.partial_reliability = capabilities_.partial_reliability;
state.capabilities.message_interleaving = capabilities_.message_interleaving;
state.capabilities.reconfig = capabilities_.reconfig;
+ state.capabilities.negotiated_maximum_incoming_streams =
+ capabilities_.negotiated_maximum_incoming_streams;
+ state.capabilities.negotiated_maximum_outgoing_streams =
+ capabilities_.negotiated_maximum_outgoing_streams;
state.my_verification_tag = my_verification_tag().value();
state.peer_verification_tag = peer_verification_tag().value();
