dcsctp: Add SCTP packet
This represents the wire encoding/decoding of SCTP packets.
Bug: webrtc:12614
Change-Id: Id7a4e4654f29eea126ea3058333f5c625606446b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/213349
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33650}
diff --git a/net/dcsctp/packet/BUILD.gn b/net/dcsctp/packet/BUILD.gn
index 5bfe74a..61bbdc8 100644
--- a/net/dcsctp/packet/BUILD.gn
+++ b/net/dcsctp/packet/BUILD.gn
@@ -198,6 +198,21 @@
]
}
+rtc_library("sctp_packet") {
+ deps = [
+ ":crc32c",
+ "../../../api:array_view",
+ "../../../rtc_base",
+ "../../../rtc_base:checks",
+ "../../../rtc_base:rtc_base_approved",
+ "../public:types",
+ ]
+ sources = [
+ "sctp_packet.cc",
+ "sctp_packet.h",
+ ]
+}
+
if (rtc_include_tests) {
rtc_library("dcsctp_packet_unittests") {
testonly = true
@@ -208,6 +223,7 @@
":crc32c",
":error_cause",
":parameter",
+ ":sctp_packet",
":tlv_trait",
"../../../api:array_view",
"../../../rtc_base:checks",
@@ -258,6 +274,7 @@
"parameter/ssn_tsn_reset_request_parameter_test.cc",
"parameter/state_cookie_parameter_test.cc",
"parameter/supported_extensions_parameter_test.cc",
+ "sctp_packet_test.cc",
"tlv_trait_test.cc",
]
}
diff --git a/net/dcsctp/packet/sctp_packet.cc b/net/dcsctp/packet/sctp_packet.cc
new file mode 100644
index 0000000..53f77ef
--- /dev/null
+++ b/net/dcsctp/packet/sctp_packet.cc
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+#include "net/dcsctp/packet/sctp_packet.h"
+
+#include <stddef.h>
+
+#include <cstdint>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "absl/memory/memory.h"
+#include "absl/types/optional.h"
+#include "api/array_view.h"
+#include "net/dcsctp/common/math.h"
+#include "net/dcsctp/packet/bounded_byte_reader.h"
+#include "net/dcsctp/packet/bounded_byte_writer.h"
+#include "net/dcsctp/packet/chunk/chunk.h"
+#include "net/dcsctp/packet/crc32c.h"
+#include "net/dcsctp/public/dcsctp_options.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/strings/string_format.h"
+
+namespace dcsctp {
+namespace {
+constexpr size_t kMaxUdpPacketSize = 65535;
+constexpr size_t kChunkTlvHeaderSize = 4;
+constexpr size_t kExpectedDescriptorCount = 4;
+} // namespace
+
+/*
+ 0 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Source Port Number | Destination Port Number |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Verification Tag |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Checksum |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+*/
+
+SctpPacket::Builder::Builder(VerificationTag verification_tag,
+ const DcSctpOptions& options)
+ : verification_tag_(verification_tag),
+ source_port_(options.local_port),
+ dest_port_(options.remote_port),
+ max_mtu_(options.mtu) {}
+
+SctpPacket::Builder& SctpPacket::Builder::Add(const Chunk& chunk) {
+ if (out_.empty()) {
+ out_.reserve(max_mtu_);
+ out_.resize(SctpPacket::kHeaderSize);
+ BoundedByteWriter<kHeaderSize> buffer(out_);
+ buffer.Store16<0>(source_port_);
+ buffer.Store16<2>(dest_port_);
+ buffer.Store32<4>(*verification_tag_);
+ // Checksum is at offset 8 - written when calling Build();
+ }
+ chunk.SerializeTo(out_);
+ if (out_.size() % 4 != 0) {
+ out_.resize(RoundUpTo4(out_.size()));
+ }
+
+ return *this;
+}
+
+std::vector<uint8_t> SctpPacket::Builder::Build() {
+ std::vector<uint8_t> out;
+ out_.swap(out);
+
+ if (!out.empty()) {
+ uint32_t crc = GenerateCrc32C(out);
+ BoundedByteWriter<kHeaderSize>(out).Store32<8>(crc);
+ }
+ return out;
+}
+
+absl::optional<SctpPacket> SctpPacket::Parse(
+ rtc::ArrayView<const uint8_t> data,
+ bool disable_checksum_verification) {
+ if (data.size() < kHeaderSize + kChunkTlvHeaderSize ||
+ data.size() > kMaxUdpPacketSize) {
+ RTC_DLOG(LS_WARNING) << "Invalid packet size";
+ return absl::nullopt;
+ }
+
+ BoundedByteReader<kHeaderSize> reader(data);
+
+ CommonHeader common_header;
+ common_header.source_port = reader.Load16<0>();
+ common_header.destination_port = reader.Load16<2>();
+ common_header.verification_tag = VerificationTag(reader.Load32<4>());
+ common_header.checksum = reader.Load32<8>();
+
+ // Create a copy of the packet, which will be held by this object.
+ std::vector<uint8_t> data_copy =
+ std::vector<uint8_t>(data.begin(), data.end());
+
+ // Verify the checksum. The checksum field must be zero when that's done.
+ BoundedByteWriter<kHeaderSize>(data_copy).Store32<8>(0);
+ uint32_t calculated_checksum = GenerateCrc32C(data_copy);
+ if (!disable_checksum_verification &&
+ calculated_checksum != common_header.checksum) {
+ RTC_DLOG(LS_WARNING) << rtc::StringFormat(
+ "Invalid packet checksum, packet_checksum=0x%08x, "
+ "calculated_checksum=0x%08x",
+ common_header.checksum, calculated_checksum);
+ return absl::nullopt;
+ }
+ // Restore the checksum in the header.
+ BoundedByteWriter<kHeaderSize>(data_copy).Store32<8>(common_header.checksum);
+
+ // Validate and parse the chunk headers in the message.
+ /*
+ 0 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Chunk Type | Chunk Flags | Chunk Length |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+ std::vector<ChunkDescriptor> descriptors;
+ descriptors.reserve(kExpectedDescriptorCount);
+ rtc::ArrayView<const uint8_t> descriptor_data =
+ rtc::ArrayView<const uint8_t>(data_copy).subview(kHeaderSize);
+ while (!descriptor_data.empty()) {
+ if (descriptor_data.size() < kChunkTlvHeaderSize) {
+ RTC_DLOG(LS_WARNING) << "Too small chunk";
+ return absl::nullopt;
+ }
+ BoundedByteReader<kChunkTlvHeaderSize> chunk_header(descriptor_data);
+ uint8_t type = chunk_header.Load8<0>();
+ uint8_t flags = chunk_header.Load8<1>();
+ uint16_t length = chunk_header.Load16<2>();
+ uint16_t padded_length = RoundUpTo4(length);
+ if (padded_length > descriptor_data.size()) {
+ RTC_DLOG(LS_WARNING) << "Too large chunk. length=" << length
+ << ", remaining=" << descriptor_data.size();
+ return absl::nullopt;
+ }
+ descriptors.emplace_back(type, flags,
+ descriptor_data.subview(0, padded_length));
+ descriptor_data = descriptor_data.subview(padded_length);
+ }
+
+ // Note that iterators (and pointer) are guaranteed to be stable when moving a
+ // std::vector, and `descriptors` have pointers to within `data_copy`.
+ return SctpPacket(common_header, std::move(data_copy),
+ std::move(descriptors));
+}
+} // namespace dcsctp
diff --git a/net/dcsctp/packet/sctp_packet.h b/net/dcsctp/packet/sctp_packet.h
new file mode 100644
index 0000000..927b8db
--- /dev/null
+++ b/net/dcsctp/packet/sctp_packet.h
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef NET_DCSCTP_PACKET_SCTP_PACKET_H_
+#define NET_DCSCTP_PACKET_SCTP_PACKET_H_
+
+#include <stddef.h>
+
+#include <cstdint>
+#include <functional>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "api/array_view.h"
+#include "net/dcsctp/common/internal_types.h"
+#include "net/dcsctp/packet/chunk/chunk.h"
+#include "net/dcsctp/public/dcsctp_options.h"
+
+namespace dcsctp {
+
+// The "Common Header", which every SCTP packet starts with, and is described in
+// https://tools.ietf.org/html/rfc4960#section-3.1.
+struct CommonHeader {
+ uint16_t source_port;
+ uint16_t destination_port;
+ VerificationTag verification_tag;
+ uint32_t checksum;
+};
+
+// Represents an immutable (received or to-be-sent) SCTP packet.
+class SctpPacket {
+ public:
+ static constexpr size_t kHeaderSize = 12;
+
+ struct ChunkDescriptor {
+ ChunkDescriptor(uint8_t type,
+ uint8_t flags,
+ rtc::ArrayView<const uint8_t> data)
+ : type(type), flags(flags), data(data) {}
+ uint8_t type;
+ uint8_t flags;
+ rtc::ArrayView<const uint8_t> data;
+ };
+
+ SctpPacket(SctpPacket&& other) = default;
+ SctpPacket& operator=(SctpPacket&& other) = default;
+ SctpPacket(const SctpPacket&) = delete;
+ SctpPacket& operator=(const SctpPacket&) = delete;
+
+ // Used for building SctpPacket, as those are immutable.
+ class Builder {
+ public:
+ Builder(VerificationTag verification_tag, const DcSctpOptions& options);
+
+ Builder(Builder&& other) = default;
+ Builder& operator=(Builder&& other) = default;
+
+ // Adds a chunk to the to-be-built SCTP packet.
+ Builder& Add(const Chunk& chunk);
+
+ // The number of bytes remaining in the packet, until the MTU is reached.
+ size_t bytes_remaining() const {
+ return out_.size() >= max_mtu_ ? 0 : max_mtu_ - out_.size();
+ }
+
+ // Indicates if any packets have been added to the builder.
+ bool empty() const { return out_.empty(); }
+
+ // Returns the payload of the build SCTP packet. The Builder will be cleared
+ // after having called this function, and can be used to build a new packet.
+ std::vector<uint8_t> Build();
+
+ private:
+ void WritePacketHeader();
+ VerificationTag verification_tag_;
+ uint16_t source_port_;
+ uint16_t dest_port_;
+ size_t max_mtu_;
+ std::vector<uint8_t> out_;
+ };
+
+ // Parses `data` as an SCTP packet and returns it if it validates.
+ static absl::optional<SctpPacket> Parse(
+ rtc::ArrayView<const uint8_t> data,
+ bool disable_checksum_verification = false);
+
+ // Returns the SCTP common header.
+ const CommonHeader& common_header() const { return common_header_; }
+
+ // Returns the chunks (types and offsets) within the packet.
+ rtc::ArrayView<const ChunkDescriptor> descriptors() const {
+ return descriptors_;
+ }
+
+ private:
+ SctpPacket(const CommonHeader& common_header,
+ std::vector<uint8_t> data,
+ std::vector<ChunkDescriptor> descriptors)
+ : common_header_(common_header),
+ data_(std::move(data)),
+ descriptors_(std::move(descriptors)) {}
+
+ CommonHeader common_header_;
+
+ // As the `descriptors_` refer to offset within data, and since SctpPacket is
+ // movable, `data` needs to be pointer stable, which it is according to
+ // http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#2321
+ std::vector<uint8_t> data_;
+ // The chunks and their offsets within `data_ `.
+ std::vector<ChunkDescriptor> descriptors_;
+};
+} // namespace dcsctp
+
+#endif // NET_DCSCTP_PACKET_SCTP_PACKET_H_
diff --git a/net/dcsctp/packet/sctp_packet_test.cc b/net/dcsctp/packet/sctp_packet_test.cc
new file mode 100644
index 0000000..ad4d0cc
--- /dev/null
+++ b/net/dcsctp/packet/sctp_packet_test.cc
@@ -0,0 +1,296 @@
+/*
+ * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+#include "net/dcsctp/packet/sctp_packet.h"
+
+#include <cstdint>
+#include <utility>
+#include <vector>
+
+#include "api/array_view.h"
+#include "net/dcsctp/common/internal_types.h"
+#include "net/dcsctp/packet/chunk/abort_chunk.h"
+#include "net/dcsctp/packet/chunk/cookie_ack_chunk.h"
+#include "net/dcsctp/packet/chunk/data_chunk.h"
+#include "net/dcsctp/packet/chunk/init_chunk.h"
+#include "net/dcsctp/packet/chunk/sack_chunk.h"
+#include "net/dcsctp/packet/error_cause/error_cause.h"
+#include "net/dcsctp/packet/error_cause/user_initiated_abort_cause.h"
+#include "net/dcsctp/packet/parameter/parameter.h"
+#include "net/dcsctp/packet/tlv_trait.h"
+#include "net/dcsctp/testing/testing_macros.h"
+#include "rtc_base/gunit.h"
+#include "test/gmock.h"
+
+namespace dcsctp {
+namespace {
+using ::testing::SizeIs;
+
+constexpr VerificationTag kVerificationTag = VerificationTag(0x12345678);
+
+TEST(SctpPacketTest, DeserializeSimplePacketFromCapture) {
+ /*
+ Stream Control Transmission Protocol, Src Port: 5000 (5000), Dst Port: 5000
+ (5000) Source port: 5000 Destination port: 5000 Verification tag: 0x00000000
+ [Association index: 1]
+ Checksum: 0xaa019d33 [unverified]
+ [Checksum Status: Unverified]
+ INIT chunk (Outbound streams: 1000, inbound streams: 1000)
+ Chunk type: INIT (1)
+ Chunk flags: 0x00
+ Chunk length: 90
+ Initiate tag: 0x0eddca08
+ Advertised receiver window credit (a_rwnd): 131072
+ Number of outbound streams: 1000
+ Number of inbound streams: 1000
+ Initial TSN: 1426601527
+ ECN parameter
+ Parameter type: ECN (0x8000)
+ Parameter length: 4
+ Forward TSN supported parameter
+ Parameter type: Forward TSN supported (0xc000)
+ Parameter length: 4
+ Supported Extensions parameter (Supported types: FORWARD_TSN, AUTH,
+ ASCONF, ASCONF_ACK, RE_CONFIG) Parameter type: Supported Extensions
+ (0x8008) Parameter length: 9 Supported chunk type: FORWARD_TSN (192) Supported
+ chunk type: AUTH (15) Supported chunk type: ASCONF (193) Supported chunk type:
+ ASCONF_ACK (128) Supported chunk type: RE_CONFIG (130) Parameter padding:
+ 000000 Random parameter Parameter type: Random (0x8002) Parameter length: 36
+ Random number: c5a86155090e6f420050634cc8d6b908dfd53e17c99cb143…
+ Requested HMAC Algorithm parameter (Supported HMACs: SHA-1)
+ Parameter type: Requested HMAC Algorithm (0x8004)
+ Parameter length: 6
+ HMAC identifier: SHA-1 (1)
+ Parameter padding: 0000
+ Authenticated Chunk list parameter (Chunk types to be authenticated:
+ ASCONF_ACK, ASCONF) Parameter type: Authenticated Chunk list
+ (0x8003) Parameter length: 6 Chunk type: ASCONF_ACK (128) Chunk type: ASCONF
+ (193) Chunk padding: 0000
+ */
+
+ uint8_t data[] = {
+ 0x13, 0x88, 0x13, 0x88, 0x00, 0x00, 0x00, 0x00, 0xaa, 0x01, 0x9d, 0x33,
+ 0x01, 0x00, 0x00, 0x5a, 0x0e, 0xdd, 0xca, 0x08, 0x00, 0x02, 0x00, 0x00,
+ 0x03, 0xe8, 0x03, 0xe8, 0x55, 0x08, 0x36, 0x37, 0x80, 0x00, 0x00, 0x04,
+ 0xc0, 0x00, 0x00, 0x04, 0x80, 0x08, 0x00, 0x09, 0xc0, 0x0f, 0xc1, 0x80,
+ 0x82, 0x00, 0x00, 0x00, 0x80, 0x02, 0x00, 0x24, 0xc5, 0xa8, 0x61, 0x55,
+ 0x09, 0x0e, 0x6f, 0x42, 0x00, 0x50, 0x63, 0x4c, 0xc8, 0xd6, 0xb9, 0x08,
+ 0xdf, 0xd5, 0x3e, 0x17, 0xc9, 0x9c, 0xb1, 0x43, 0x28, 0x4e, 0xaf, 0x64,
+ 0x68, 0x2a, 0xc2, 0x97, 0x80, 0x04, 0x00, 0x06, 0x00, 0x01, 0x00, 0x00,
+ 0x80, 0x03, 0x00, 0x06, 0x80, 0xc1, 0x00, 0x00};
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SctpPacket packet, SctpPacket::Parse(data));
+ EXPECT_EQ(packet.common_header().source_port, 5000);
+ EXPECT_EQ(packet.common_header().destination_port, 5000);
+ EXPECT_EQ(packet.common_header().verification_tag, VerificationTag(0));
+ EXPECT_EQ(packet.common_header().checksum, 0xaa019d33);
+
+ EXPECT_THAT(packet.descriptors(), SizeIs(1));
+ EXPECT_EQ(packet.descriptors()[0].type, InitChunk::kType);
+ ASSERT_HAS_VALUE_AND_ASSIGN(InitChunk init,
+ InitChunk::Parse(packet.descriptors()[0].data));
+ EXPECT_EQ(init.initial_tsn(), TSN(1426601527));
+}
+
+TEST(SctpPacketTest, DeserializePacketWithTwoChunks) {
+ /*
+ Stream Control Transmission Protocol, Src Port: 1234 (1234),
+ Dst Port: 4321 (4321)
+ Source port: 1234
+ Destination port: 4321
+ Verification tag: 0x697e3a4e
+ [Association index: 3]
+ Checksum: 0xc06e8b36 [unverified]
+ [Checksum Status: Unverified]
+ COOKIE_ACK chunk
+ Chunk type: COOKIE_ACK (11)
+ Chunk flags: 0x00
+ Chunk length: 4
+ SACK chunk (Cumulative TSN: 2930332242, a_rwnd: 131072,
+ gaps: 0, duplicate TSNs: 0)
+ Chunk type: SACK (3)
+ Chunk flags: 0x00
+ Chunk length: 16
+ Cumulative TSN ACK: 2930332242
+ Advertised receiver window credit (a_rwnd): 131072
+ Number of gap acknowledgement blocks: 0
+ Number of duplicated TSNs: 0
+ */
+
+ uint8_t data[] = {0x04, 0xd2, 0x10, 0xe1, 0x69, 0x7e, 0x3a, 0x4e,
+ 0xc0, 0x6e, 0x8b, 0x36, 0x0b, 0x00, 0x00, 0x04,
+ 0x03, 0x00, 0x00, 0x10, 0xae, 0xa9, 0x52, 0x52,
+ 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SctpPacket packet, SctpPacket::Parse(data));
+ EXPECT_EQ(packet.common_header().source_port, 1234);
+ EXPECT_EQ(packet.common_header().destination_port, 4321);
+ EXPECT_EQ(packet.common_header().verification_tag,
+ VerificationTag(0x697e3a4eu));
+ EXPECT_EQ(packet.common_header().checksum, 0xc06e8b36u);
+
+ EXPECT_THAT(packet.descriptors(), SizeIs(2));
+ EXPECT_EQ(packet.descriptors()[0].type, CookieAckChunk::kType);
+ EXPECT_EQ(packet.descriptors()[1].type, SackChunk::kType);
+ ASSERT_HAS_VALUE_AND_ASSIGN(
+ CookieAckChunk cookie_ack,
+ CookieAckChunk::Parse(packet.descriptors()[0].data));
+ ASSERT_HAS_VALUE_AND_ASSIGN(SackChunk sack,
+ SackChunk::Parse(packet.descriptors()[1].data));
+}
+
+TEST(SctpPacketTest, DeserializePacketWithWrongChecksum) {
+ /*
+ Stream Control Transmission Protocol, Src Port: 5000 (5000),
+ Dst Port: 5000 (5000)
+ Source port: 5000
+ Destination port: 5000
+ Verification tag: 0x0eddca08
+ [Association index: 1]
+ Checksum: 0x2a81f531 [unverified]
+ [Checksum Status: Unverified]
+ SACK chunk (Cumulative TSN: 1426601536, a_rwnd: 131072,
+ gaps: 0, duplicate TSNs: 0)
+ Chunk type: SACK (3)
+ Chunk flags: 0x00
+ Chunk length: 16
+ Cumulative TSN ACK: 1426601536
+ Advertised receiver window credit (a_rwnd): 131072
+ Number of gap acknowledgement blocks: 0
+ Number of duplicated TSNs: 0
+ */
+
+ uint8_t data[] = {0x13, 0x88, 0x13, 0x88, 0x0e, 0xdd, 0xca, 0x08, 0x2a, 0x81,
+ 0xf5, 0x31, 0x03, 0x00, 0x00, 0x10, 0x55, 0x08, 0x36, 0x40,
+ 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+ EXPECT_FALSE(SctpPacket::Parse(data).has_value());
+}
+
+TEST(SctpPacketTest, DeserializePacketDontValidateChecksum) {
+ /*
+ Stream Control Transmission Protocol, Src Port: 5000 (5000),
+ Dst Port: 5000 (5000)
+ Source port: 5000
+ Destination port: 5000
+ Verification tag: 0x0eddca08
+ [Association index: 1]
+ Checksum: 0x2a81f531 [unverified]
+ [Checksum Status: Unverified]
+ SACK chunk (Cumulative TSN: 1426601536, a_rwnd: 131072,
+ gaps: 0, duplicate TSNs: 0)
+ Chunk type: SACK (3)
+ Chunk flags: 0x00
+ Chunk length: 16
+ Cumulative TSN ACK: 1426601536
+ Advertised receiver window credit (a_rwnd): 131072
+ Number of gap acknowledgement blocks: 0
+ Number of duplicated TSNs: 0
+ */
+
+ uint8_t data[] = {0x13, 0x88, 0x13, 0x88, 0x0e, 0xdd, 0xca, 0x08, 0x2a, 0x81,
+ 0xf5, 0x31, 0x03, 0x00, 0x00, 0x10, 0x55, 0x08, 0x36, 0x40,
+ 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(
+ SctpPacket packet,
+ SctpPacket::Parse(data, /*disable_checksum_verification=*/true));
+ EXPECT_EQ(packet.common_header().source_port, 5000);
+ EXPECT_EQ(packet.common_header().destination_port, 5000);
+ EXPECT_EQ(packet.common_header().verification_tag,
+ VerificationTag(0x0eddca08u));
+ EXPECT_EQ(packet.common_header().checksum, 0x2a81f531u);
+}
+
+TEST(SctpPacketTest, SerializeAndDeserializeSingleChunk) {
+ SctpPacket::Builder b(kVerificationTag, {});
+ InitChunk init(/*initiate_tag=*/VerificationTag(123), /*a_rwnd=*/456,
+ /*nbr_outbound_streams=*/65535,
+ /*nbr_inbound_streams=*/65534, /*initial_tsn=*/TSN(789),
+ /*parameters=*/Parameters());
+
+ b.Add(init);
+ std::vector<uint8_t> serialized = b.Build();
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SctpPacket packet, SctpPacket::Parse(serialized));
+
+ EXPECT_EQ(packet.common_header().verification_tag, kVerificationTag);
+
+ ASSERT_THAT(packet.descriptors(), SizeIs(1));
+ EXPECT_EQ(packet.descriptors()[0].type, InitChunk::kType);
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(InitChunk deserialized,
+ InitChunk::Parse(packet.descriptors()[0].data));
+ EXPECT_EQ(deserialized.initiate_tag(), VerificationTag(123));
+ EXPECT_EQ(deserialized.a_rwnd(), 456u);
+ EXPECT_EQ(deserialized.nbr_outbound_streams(), 65535u);
+ EXPECT_EQ(deserialized.nbr_inbound_streams(), 65534u);
+ EXPECT_EQ(deserialized.initial_tsn(), TSN(789));
+}
+
+TEST(SctpPacketTest, SerializeAndDeserializeThreeChunks) {
+ SctpPacket::Builder b(kVerificationTag, {});
+ b.Add(SackChunk(/*cumulative_tsn_ack=*/TSN(999), /*a_rwnd=*/456,
+ {SackChunk::GapAckBlock(2, 3)},
+ /*duplicate_tsns=*/{TSN(1), TSN(2), TSN(3)}));
+ b.Add(DataChunk(TSN(123), StreamID(456), SSN(789), PPID(9090),
+ /*payload=*/{1, 2, 3, 4, 5},
+ /*options=*/{}));
+ b.Add(DataChunk(TSN(124), StreamID(654), SSN(987), PPID(909),
+ /*payload=*/{5, 4, 3, 3, 1},
+ /*options=*/{}));
+
+ std::vector<uint8_t> serialized = b.Build();
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SctpPacket packet, SctpPacket::Parse(serialized));
+
+ EXPECT_EQ(packet.common_header().verification_tag, kVerificationTag);
+
+ ASSERT_THAT(packet.descriptors(), SizeIs(3));
+ EXPECT_EQ(packet.descriptors()[0].type, SackChunk::kType);
+ EXPECT_EQ(packet.descriptors()[1].type, DataChunk::kType);
+ EXPECT_EQ(packet.descriptors()[2].type, DataChunk::kType);
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SackChunk sack,
+ SackChunk::Parse(packet.descriptors()[0].data));
+ EXPECT_EQ(sack.cumulative_tsn_ack(), TSN(999));
+ EXPECT_EQ(sack.a_rwnd(), 456u);
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(DataChunk data1,
+ DataChunk::Parse(packet.descriptors()[1].data));
+ EXPECT_EQ(data1.tsn(), TSN(123));
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(DataChunk data2,
+ DataChunk::Parse(packet.descriptors()[2].data));
+ EXPECT_EQ(data2.tsn(), TSN(124));
+}
+
+TEST(SctpPacketTest, ParseAbortWithEmptyCause) {
+ SctpPacket::Builder b(kVerificationTag, {});
+ b.Add(AbortChunk(
+ /*filled_in_verification_tag=*/true,
+ Parameters::Builder().Add(UserInitiatedAbortCause("")).Build()));
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(SctpPacket packet, SctpPacket::Parse(b.Build()));
+
+ EXPECT_EQ(packet.common_header().verification_tag, kVerificationTag);
+
+ ASSERT_THAT(packet.descriptors(), SizeIs(1));
+ EXPECT_EQ(packet.descriptors()[0].type, AbortChunk::kType);
+
+ ASSERT_HAS_VALUE_AND_ASSIGN(AbortChunk abort,
+ AbortChunk::Parse(packet.descriptors()[0].data));
+ ASSERT_HAS_VALUE_AND_ASSIGN(
+ UserInitiatedAbortCause cause,
+ abort.error_causes().get<UserInitiatedAbortCause>());
+ EXPECT_EQ(cause.upper_layer_abort_reason(), "");
+}
+
+} // namespace
+} // namespace dcsctp
