i2p: initial support

8 files changed, 358 insertions, 5 deletions

diff --git a/src/net/CMakeLists.txt b/src/net/CMakeLists.txt
index a81372125..fdb988f39 100644
--- a/src/net/CMakeLists.txt
+++ b/src/net/CMakeLists.txt
@@ -26,8 +26,8 @@
 # STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 # THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-set(net_sources error.cpp parse.cpp socks.cpp tor_address.cpp)
-set(net_headers error.h parse.h socks.h tor_address.h)
+set(net_sources error.cpp parse.cpp socks.cpp tor_address.cpp i2p_address.cpp)
+set(net_headers error.h parse.h socks.h tor_address.h i2p_address.h)
 
 monero_add_library(net ${net_sources} ${net_headers})
 target_link_libraries(net epee ${Boost_ASIO_LIBRARY})
diff --git a/src/net/fwd.h b/src/net/fwd.h
index ee7c539b0..7cae88251 100644
--- a/src/net/fwd.h
+++ b/src/net/fwd.h
@@ -34,6 +34,7 @@ namespace net
 {
     enum class error : int;
     class tor_address;
+    class i2p_address;
 
     namespace socks
     {
diff --git a/src/net/i2p_address.cpp b/src/net/i2p_address.cpp
new file mode 100644
index 000000000..cba829d3f
--- /dev/null
+++ b/src/net/i2p_address.cpp
@@ -0,0 +1,200 @@
+// Copyright (c) 2019, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "i2p_address.h"
+
+#include <algorithm>
+#include <boost/spirit/include/karma_generate.hpp>
+#include <boost/spirit/include/karma_uint.hpp>
+#include <cassert>
+#include <cstring>
+#include <limits>
+
+#include "net/error.h"
+#include "serialization/keyvalue_serialization.h"
+#include "storages/portable_storage.h"
+#include "string_tools.h"
+
+namespace net
+{
+    namespace
+    {
+        // !TODO only b32 addresses right now
+        constexpr const char tld[] = u8".b32.i2p";
+        constexpr const char unknown_host[] = "<unknown i2p host>";
+
+        constexpr const unsigned b32_length = 52;
+
+        constexpr const char base32_alphabet[] =
+            u8"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz234567";
+
+        expect<void> host_check(boost::string_ref host) noexcept
+        {
+            if (!host.ends_with(tld))
+                return {net::error::expected_tld};
+
+            host.remove_suffix(sizeof(tld) - 1);
+
+            if (host.size() != b32_length)
+                return {net::error::invalid_i2p_address};
+            if (host.find_first_not_of(base32_alphabet) != boost::string_ref::npos)
+                return {net::error::invalid_i2p_address};
+
+            return success();
+        }
+
+        struct i2p_serialized
+        {
+            std::string host;
+            std::uint16_t port;
+
+            BEGIN_KV_SERIALIZE_MAP()
+                KV_SERIALIZE(host)
+                KV_SERIALIZE(port)
+            END_KV_SERIALIZE_MAP()
+        };
+    }
+
+    i2p_address::i2p_address(const boost::string_ref host, const std::uint16_t port) noexcept
+      : port_(port)
+    {
+        // this is a private constructor, throw if moved to public
+        assert(host.size() < sizeof(host_));
+
+        const std::size_t length = std::min(sizeof(host_) - 1, host.size());
+        std::memcpy(host_, host.data(), length);
+        std::memset(host_ + length, 0, sizeof(host_) - length);
+    }
+
+    const char* i2p_address::unknown_str() noexcept
+    {
+        return unknown_host;
+    }
+
+    i2p_address::i2p_address() noexcept
+      : port_(0)
+    {
+        static_assert(sizeof(unknown_host) <= sizeof(host_), "bad buffer size");
+        std::memcpy(host_, unknown_host, sizeof(unknown_host));
+        std::memset(host_ + sizeof(unknown_host), 0, sizeof(host_) - sizeof(unknown_host));
+    }
+
+    expect<i2p_address> i2p_address::make(const boost::string_ref address, const std::uint16_t default_port)
+    {
+        boost::string_ref host = address.substr(0, address.rfind(':'));
+        const boost::string_ref port =
+            address.substr(host.size() + (host.size() == address.size() ? 0 : 1));
+
+        MONERO_CHECK(host_check(host));
+
+        std::uint16_t porti = default_port;
+        if (!port.empty() && !epee::string_tools::get_xtype_from_string(porti, std::string{port}))
+            return {net::error::invalid_port};
+
+        static_assert(b32_length + sizeof(tld) == sizeof(i2p_address::host_), "bad internal host size");
+        return i2p_address{host, porti};
+    }
+
+    bool i2p_address::_load(epee::serialization::portable_storage& src, epee::serialization::section* hparent)
+    {
+        i2p_serialized in{};
+        if (in._load(src, hparent) && in.host.size() < sizeof(host_) && (in.host == unknown_host || !host_check(in.host).has_error()))
+        {
+            std::memcpy(host_, in.host.data(), in.host.size());
+            std::memset(host_ + in.host.size(), 0, sizeof(host_) - in.host.size());
+            port_ = in.port;
+            return true;
+        }
+        static_assert(sizeof(unknown_host) <= sizeof(host_), "bad buffer size");
+        std::memcpy(host_, unknown_host, sizeof(unknown_host)); // include null terminator
+        port_ = 0;
+        return false;
+    }
+
+    bool i2p_address::store(epee::serialization::portable_storage& dest, epee::serialization::section* hparent) const
+    {
+        const i2p_serialized out{std::string{host_}, port_};
+        return out.store(dest, hparent);
+    }
+
+    i2p_address::i2p_address(const i2p_address& rhs) noexcept
+      : port_(rhs.port_)
+    {
+        std::memcpy(host_, rhs.host_, sizeof(host_));
+    }
+
+    i2p_address& i2p_address::operator=(const i2p_address& rhs) noexcept
+    {
+        if (this != std::addressof(rhs))
+        {
+            port_ = rhs.port_;
+            std::memcpy(host_, rhs.host_, sizeof(host_));
+        }
+        return *this;
+    }
+
+    bool i2p_address::is_unknown() const noexcept
+    {
+        static_assert(1 <= sizeof(host_), "host size too small");
+        return host_[0] == '<'; // character is not allowed otherwise
+    }
+
+    bool i2p_address::equal(const i2p_address& rhs) const noexcept
+    {
+        return port_ == rhs.port_ && is_same_host(rhs);
+    }
+
+    bool i2p_address::less(const i2p_address& rhs) const noexcept
+    {
+        return std::strcmp(host_str(), rhs.host_str()) < 0 || port() < rhs.port();
+    }
+
+    bool i2p_address::is_same_host(const i2p_address& rhs) const noexcept
+    {
+        return std::strcmp(host_str(), rhs.host_str()) == 0;
+    }
+
+    std::string i2p_address::str() const
+    {
+        const std::size_t host_length = std::strlen(host_str());
+        const std::size_t port_length =
+            port_ == 0 ? 0 : std::numeric_limits<std::uint16_t>::digits10 + 2;
+
+        std::string out{};
+        out.reserve(host_length + port_length);
+        out.assign(host_str(), host_length);
+
+        if (port_ != 0)
+        {
+            out.push_back(':');
+            namespace karma = boost::spirit::karma;
+            karma::generate(std::back_inserter(out), karma::ushort_, port());
+        }
+        return out;
+    }
+}
diff --git a/src/net/i2p_address.h b/src/net/i2p_address.h
new file mode 100644
index 000000000..28a1118ba
--- /dev/null
+++ b/src/net/i2p_address.h
@@ -0,0 +1,140 @@
+// Copyright (c) 2019, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include <boost/utility/string_ref.hpp>
+#include <cstdint>
+#include <string>
+
+#include "common/expect.h"
+#include "net/enums.h"
+#include "net/error.h"
+
+namespace epee
+{
+namespace serialization
+{
+    class portable_storage;
+    struct section;
+}
+}
+
+namespace net
+{
+    //! b32 i2p address; internal format not condensed/decoded.
+    class i2p_address
+    {
+        std::uint16_t port_;
+        char host_[61]; // null-terminated
+
+        //! Keep in private, `host.size()` has no runtime check
+        i2p_address(boost::string_ref host, std::uint16_t port) noexcept;
+
+    public:
+        //! \return Size of internal buffer for host.
+        static constexpr std::size_t buffer_size() noexcept { return sizeof(host_); }
+
+        //! \return `<unknown tor host>`.
+        static const char* unknown_str() noexcept;
+
+        //! An object with `port() == 0` and `host_str() == unknown_str()`.
+        i2p_address() noexcept;
+
+        //! \return A default constructed `i2p_address` object.
+        static i2p_address unknown() noexcept { return i2p_address{}; }
+
+        /*!
+            Parse `address` in b32 i2p format (i.e. x.b32.i2p:80)
+            with `default_port` being used if port is not specified in
+            `address`.
+        */
+        static expect<i2p_address> make(boost::string_ref address, std::uint16_t default_port = 0);
+
+        //! Load from epee p2p format, and \return false if not valid tor address
+        bool _load(epee::serialization::portable_storage& src, epee::serialization::section* hparent);
+
+        //! Store in epee p2p format
+        bool store(epee::serialization::portable_storage& dest, epee::serialization::section* hparent) const;
+
+        // Moves and copies are currently identical
+
+        i2p_address(const i2p_address& rhs) noexcept;
+        ~i2p_address() = default;
+        i2p_address& operator=(const i2p_address& rhs) noexcept;
+
+        //! \return True if default constructed or via `unknown()`.
+        bool is_unknown() const noexcept;
+
+        bool equal(const i2p_address& rhs) const noexcept;
+        bool less(const i2p_address& rhs) const noexcept;
+
+        //! \return True if i2p addresses are identical.
+        bool is_same_host(const i2p_address& rhs) const noexcept;
+
+        //! \return `x.b32.i2p` or `x.b32.i2p:z` if `port() != 0`.
+        std::string str() const;
+
+        //! \return Null-terminated `x.b32.i2p` value or `unknown_str()`.
+        const char* host_str() const noexcept { return host_; }
+
+        //! \return Port value or `0` if unspecified.
+        std::uint16_t port() const noexcept { return port_; }
+
+        static constexpr bool is_loopback() noexcept { return false; }
+        static constexpr bool is_local() noexcept { return false; }
+
+        static constexpr epee::net_utils::address_type get_type_id() noexcept
+        {
+            return epee::net_utils::address_type::i2p;
+        }
+
+        static constexpr epee::net_utils::zone get_zone() noexcept
+        {
+            return epee::net_utils::zone::i2p;
+        }
+
+        //! \return `!is_unknown()`.
+        bool is_blockable() const noexcept { return !is_unknown(); }
+    };
+
+    inline bool operator==(const i2p_address& lhs, const i2p_address& rhs) noexcept
+    {
+        return lhs.equal(rhs);
+    }
+
+    inline bool operator!=(const i2p_address& lhs, const i2p_address& rhs) noexcept
+    {
+        return !lhs.equal(rhs);
+    }
+
+    inline bool operator<(const i2p_address& lhs, const i2p_address& rhs) noexcept
+    {
+        return lhs.less(rhs);
+    }
+} // net
diff --git a/src/net/parse.cpp b/src/net/parse.cpp
index ebf91eeff..eaaadb67e 100644
--- a/src/net/parse.cpp
+++ b/src/net/parse.cpp
@@ -29,6 +29,7 @@
 #include "parse.h"
 
 #include "net/tor_address.h"
+#include "net/i2p_address.h"
 #include "string_tools.h"
 
 namespace net
@@ -43,7 +44,7 @@ namespace net
         if (host.ends_with(".onion"))
             return tor_address::make(address, default_port);
         if (host.ends_with(".i2p"))
-            return make_error_code(net::error::invalid_i2p_address); // not yet implemented (prevent public DNS lookup)
+            return i2p_address::make(address, default_port);
 
         std::uint16_t port = default_port;
         if (host.size() < address.size())
diff --git a/src/net/parse.h b/src/net/parse.h
index 9195ddc2b..5804c4128 100644
--- a/src/net/parse.h
+++ b/src/net/parse.h
@@ -37,11 +37,11 @@
 namespace net
 {
     /*!
-      Identifies onion and IPv4 addresses and returns them as a generic
+      Identifies onion, i2p and IPv4 addresses and returns them as a generic
       `network_address`. If the type is unsupported, it might be a hostname,
       and `error() == net::error::kUnsupportedAddress` is returned.
 
-      \param address An onion address, ipv4 address or hostname. Hostname
+      \param address An onion address, i2p address, ipv4 address or hostname. Hostname
           will return an error.
       \param default_port If `address` does not specify a port, this value
           will be used.
diff --git a/src/net/socks.cpp b/src/net/socks.cpp
index f31efc8c1..53154369b 100644
--- a/src/net/socks.cpp
+++ b/src/net/socks.cpp
@@ -40,6 +40,7 @@
 
 #include "net/net_utils_base.h"
 #include "net/tor_address.h"
+#include "net/i2p_address.h"
 
 namespace net
 {
@@ -273,6 +274,13 @@ namespace socks
         return false;
     }
 
+    bool client::set_connect_command(const net::i2p_address& address)
+    {
+        if (!address.is_unknown())
+            return set_connect_command(address.host_str(), address.port());
+        return false;
+    }
+
     bool client::set_resolve_command(boost::string_ref domain)
     {
         if (socks_version() != version::v4a_tor)
diff --git a/src/net/socks.h b/src/net/socks.h
index d29a51ccb..825937792 100644
--- a/src/net/socks.h
+++ b/src/net/socks.h
@@ -155,6 +155,9 @@ namespace socks
         //! Try to set `address` as remote Tor hidden service connection request.
         bool set_connect_command(const net::tor_address& address);
 
+        //! Try to set `address` as remote i2p hidden service connection request.
+        bool set_connect_command(const net::i2p_address& address);
+
         //! Try to set `domain` as remote DNS A record lookup request.
         bool set_resolve_command(boost::string_ref domain);