Fix DNS and IPFS for Multiaddr (#43)

* Add DNS processing to multiaddr
* Fix IPFS resolution in multiaddr
* Fix comment about IPFS/P2P in multiaddr

Author: Harrm

include/libp2p/multi/converters/dns_converter.hpp

@@ -0,0 +1,25 @@
+/**
+ * Copyright Soramitsu Co., Ltd. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef LIBP2P_DNS_CONVERTER_HPP
+#define LIBP2P_DNS_CONVERTER_HPP
+
+#include <libp2p/outcome/outcome.hpp>
+
+namespace libp2p::multi::converters {
+
+  /**
+   * Converts a DNS part of a multiaddress (a hostname)
+   * to bytes representation as a hex string
+   */
+  class DnsConverter {
+   public:
+    static auto addressToHex(std::string_view addr)
+    -> outcome::result<std::string>;
+  };
+
+}  // namespace libp2p::multi::converters
+
+#endif  // LIBP2P_DNS_CONVERTER_HPP

include/libp2p/multi/multiaddress_protocol_list.hpp

@@ -78,6 +78,9 @@ namespace libp2p::multi {
      * otherwise
      */
     static constexpr auto get(std::string_view name) -> Protocol const * {
+      if(name == "ipfs") {
+        name = "p2p";  // IPFS is a legacy name, P2P is the preferred one
+      }
       for (Protocol const &protocol : protocols_) {
         if (protocol.name == name) {
           return &protocol;
@@ -120,15 +123,15 @@ namespace libp2p::multi {
         {Protocol::Code::IP6, 128, "ip6"},
         {Protocol::Code::IP6_ZONE, Protocol::kVarLen, "ip6zone"},
         {Protocol::Code::DNS, Protocol::kVarLen, "dns"},
-        {Protocol::Code::DNS4, Protocol::kVarLen, "dns64"},
+        {Protocol::Code::DNS4, Protocol::kVarLen, "dns4"},
         {Protocol::Code::DNS6, Protocol::kVarLen, "dns6"},
         {Protocol::Code::DNS_ADDR, Protocol::kVarLen, "dnsaddr"},
         {Protocol::Code::SCTP, 16, "sctp"},
         {Protocol::Code::UDT, 0, "udt"},
         {Protocol::Code::UTP, 0, "utp"},
         {Protocol::Code::UNIX, Protocol::kVarLen, "unix"},
-        // {Protocol::Code::P2P, Protocol::kVarLen, "p2p"},
-        {Protocol::Code::P2P, Protocol::kVarLen, "ipfs"},
+        {Protocol::Code::P2P, Protocol::kVarLen, "p2p"},
+        // Also P2P protocol may have a legacy name "ipfs"
         {Protocol::Code::ONION, 96, "onion"},
         {Protocol::Code::ONION3, 296, "onion3"},
         {Protocol::Code::GARLIC64, Protocol::kVarLen, "garlic64"},

src/multi/converters/CMakeLists.txt

@@ -11,6 +11,7 @@ libp2p_add_library(p2p_converters
     tcp_converter.cpp
     udp_converter.cpp
     ipfs_converter.cpp
+    dns_converter.cpp
     )
 target_link_libraries(p2p_converters
     Boost::boost

src/multi/converters/converter_utils.cpp

@@ -14,6 +14,7 @@
 #include <libp2p/multi/converters/ip_v4_converter.hpp>
 #include <libp2p/multi/converters/ip_v6_converter.hpp>
 #include <libp2p/multi/converters/ipfs_converter.hpp>
+#include <libp2p/multi/converters/dns_converter.hpp>
 #include <libp2p/multi/converters/tcp_converter.hpp>
 #include <libp2p/multi/converters/udp_converter.hpp>
 #include <libp2p/multi/multiaddress_protocol_list.hpp>
@@ -89,12 +90,14 @@ namespace libp2p::multi::converters {
       case Protocol::Code::P2P:
         return IpfsConverter::addressToHex(addr);
 
-      case Protocol::Code::IP6_ZONE:
       case Protocol::Code::DNS:
       case Protocol::Code::DNS4:
       case Protocol::Code::DNS6:
       case Protocol::Code::DNS_ADDR:
       case Protocol::Code::UNIX:
+        return DnsConverter::addressToHex(addr);
+
+      case Protocol::Code::IP6_ZONE:
       case Protocol::Code::ONION3:
       case Protocol::Code::GARLIC64:
       case Protocol::Code::QUIC:
@@ -127,7 +130,7 @@ namespace libp2p::multi::converters {
         return ConversionError::NO_SUCH_PROTOCOL;
       }
 
-      if (protocol->name != "ipfs") {
+      if (protocol->name != "ipfs" and protocol->name != "p2p") {
         lastpos = lastpos
             + UVarint::calculateSize(pid_bytes.subspan(lastpos / 2)) * 2;
         std::string address;

src/multi/converters/dns_converter.cpp

@@ -0,0 +1,20 @@
+/**
+ * Copyright Soramitsu Co., Ltd. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <libp2p/multi/converters/dns_converter.hpp>
+
+#include <libp2p/common/hexutil.hpp>
+#include <libp2p/multi/uvarint.hpp>
+
+namespace libp2p::multi::converters {
+
+  auto DnsConverter::addressToHex(std::string_view addr)
+      -> outcome::result<std::string> {
+    std::vector<uint8_t> bytes(addr.size());
+    std::copy(addr.begin(), addr.end(), bytes.begin());
+    auto hex = common::hex_lower(bytes);
+    return UVarint{bytes.size()}.toHex() + hex;
+  }
+}

src/multi/multiaddress.cpp

@@ -127,6 +127,17 @@ namespace libp2p::multi {
   bool Multiaddress::decapsulateStringFromAddress(std::string_view proto,
                                                   const ByteBuffer &bytes) {
     auto str_pos = stringified_address_.rfind(proto);
+    if (proto == "/p2p" or proto == "/ipfs") {
+      auto alt_pos =
+          stringified_address_.rfind(proto == "/ipfs" ? "/p2p" : "/ipfs");
+      if (alt_pos != std::string::npos) {
+        if(str_pos == std::string::npos) {
+          str_pos = alt_pos;
+        } else {
+          str_pos = std::max(str_pos, alt_pos);
+        }
+      }
+    }
     if (str_pos == std::string::npos) {
       return false;
     }
@@ -167,6 +178,12 @@ namespace libp2p::multi {
     auto proto_str = "/"s + std::string(protocol->name);
     auto proto_positions =
         findSubstringOccurrences(stringified_address_, proto_str);
+    if (proto == Protocol::Code::P2P) {  // ipfs and p2p are equivalent
+      auto ipfs_occurences =
+          findSubstringOccurrences(stringified_address_, "/ipfs"s);
+      proto_positions.insert(proto_positions.end(), ipfs_occurences.begin(),
+                             ipfs_occurences.end());
+    }
 
     for (const auto &pos : proto_positions) {
       auto value_pos = stringified_address_.find_first_of('/', pos + 1) + 1;

test/libp2p/multi/multiaddress_test.cpp

@@ -38,9 +38,7 @@ class MultiaddressTest : public ::testing::Test {
  * @then creation succeeds
  */
 TEST_F(MultiaddressTest, CreateFromStringValid) {
-  auto result = Multiaddress::create(valid_ip_udp);
-  ASSERT_TRUE(result);
-  auto &&address = result.value();
+  EXPECT_OUTCOME_TRUE(address, Multiaddress::create(valid_ip_udp));
   ASSERT_EQ(address.getStringAddress(), valid_ip_udp);
   ASSERT_EQ(address.getBytesAddress(), valid_ip_udp_bytes);
 }
@@ -245,3 +243,15 @@ TEST_F(MultiaddressTest, GetProtocolsWithValues) {
                   std::make_pair(*ProtocolList::get("ip4"), "127.0.0.1"),
                   std::make_pair(*ProtocolList::get("udp"), "3232")));
 }
+
+/**
+ * @given a multiaddr containing DNS and P2P entries
+ * @when parsing it
+ * @then it is accepted
+ */
+TEST_F(MultiaddressTest, DnsAndIpfs) {
+  auto addr = "/dns4/kusama-bootnode-1.paritytech.net/tcp/30333/p2p/QmV32G18YzenpNFmhqg2n7TtdjYRK7oU6FhLbDL4oRgsbe"s;
+  EXPECT_OUTCOME_TRUE(address, Multiaddress::create(addr));
+  ASSERT_EQ(address.getStringAddress(), addr);
+
+}

test/libp2p/multi/utils/string_from_to_bytes_test.cpp

@@ -79,19 +79,19 @@ TEST(AddressConverter, BytesToString) {
   VALID_BYTES_TO_STR("/udp/1234", "910204D2")
   VALID_BYTES_TO_STR("/tcp/1234", "0604D2")
   VALID_BYTES_TO_STR(
-      "/ipfs/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC/tcp/1234",
+      "/p2p/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC/tcp/1234",
       "A503221220D52EBB89D85B02A284948203A62FF28389C57C9F42BEEC4EC20DB76A68911C"
       "0B0604D2")
   VALID_BYTES_TO_STR("/ip4/127.0.0.1/udp/1234", "047F000001910204D2")
   VALID_BYTES_TO_STR("/ip4/127.0.0.1/udp/0", "047F00000191020000")
   VALID_BYTES_TO_STR("/ip4/127.0.0.1/tcp/1234/udp/0/udp/1234",
                      "047F0000010604D291020000910204D2")
   VALID_BYTES_TO_STR(
-      "/ip4/127.0.0.1/ipfs/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC",
+      "/ip4/127.0.0.1/p2p/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC",
       "047F000001A503221220D52EBB89D85B02A284948203A62FF28389C57C9F42BEEC4EC20D"
       "B76A68911C0B")
   VALID_BYTES_TO_STR(
-      "/ip4/127.0.0.1/ipfs/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC/tcp/"
+      "/ip4/127.0.0.1/p2p/QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC/tcp/"
       "1234",
       "047F000001A503221220D52EBB89D85B02A284948203A62FF28389C57C9F42BEEC4EC20D"
       "B76A68911C0B0604D2")

test/libp2p/peer/peer_address_test.cpp

@@ -36,7 +36,7 @@ class PeerAddressTest : public ::testing::Test {
       Multiaddress::create("/ip4/192.168.0.1/tcp/228").value();
 
   const std::string kaddressString =
-      std::string{kDefaultAddress.getStringAddress()} + "/ipfs/"
+      std::string{kDefaultAddress.getStringAddress()} + "/p2p/"
       + kEncodedDefaultPeerId;
 };