mirror of
https://github.com/oxen-io/lokinet.git
synced 2024-11-03 23:15:52 +00:00
9fdde65798
actually open new RCs in binary mode clang-format win32 skeleton code for tun (still working on the guts)
962 lines
26 KiB
C++
962 lines
26 KiB
C++
#include <llarp/link/utp.hpp>
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#include "router.hpp"
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#include <llarp/messages/link_intro.hpp>
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#include <llarp/messages/discard.hpp>
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#include <llarp/buffer.hpp>
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#include <llarp/endian.h>
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#include <utp.h>
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#include <cassert>
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#include <tuple>
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#include <deque>
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#ifdef __linux__
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#include <linux/errqueue.h>
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#include <netinet/ip_icmp.h>
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#endif
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#ifdef _WIN32
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#include <winsock2.h>
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#include <ws2tcpip.h>
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#include <wspiapi.h>
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#endif
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namespace llarp
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{
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namespace utp
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{
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constexpr size_t FragmentHashSize = 32;
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constexpr size_t FragmentNonceSize = 24;
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constexpr size_t FragmentOverheadSize =
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FragmentHashSize + FragmentNonceSize;
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constexpr size_t FragmentBodyPayloadSize = 1024;
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constexpr size_t FragmentBodyOverhead = sizeof(uint32_t) * 2;
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constexpr size_t FragmentBodySize =
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FragmentBodyOverhead + FragmentBodyPayloadSize;
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constexpr size_t FragmentBufferSize =
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FragmentOverheadSize + FragmentBodySize;
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typedef llarp::AlignedBuffer< FragmentBufferSize > FragmentBuffer;
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constexpr size_t MaxSend = 64;
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/// maximum size for send queue for a session before we drop
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constexpr size_t MaxSendQueueSize = 128;
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typedef llarp::AlignedBuffer< MAX_LINK_MSG_SIZE > MessageBuffer;
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struct LinkLayer;
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struct BaseSession : public ILinkSession
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{
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RouterContact remoteRC;
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utp_socket* sock;
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LinkLayer* parent;
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bool gotLIM;
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PubKey remoteTransportPubKey;
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Addr remoteAddr;
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SharedSecret sessionKey;
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llarp_time_t lastActive;
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const static llarp_time_t sessionTimeout = 30 * 1000;
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std::deque< utp_iovec > vecq;
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std::deque< FragmentBuffer > sendq;
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FragmentBuffer recvBuf;
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size_t recvBufOffset;
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MessageBuffer recvMsg;
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size_t recvMsgOffset;
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bool stalled = false;
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void
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Alive();
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/// base
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BaseSession(LinkLayer* p);
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/// outbound
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BaseSession(LinkLayer* p, utp_socket* s, const RouterContact& rc,
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const AddressInfo& addr);
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/// inbound
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BaseSession(LinkLayer* p, utp_socket* s, const Addr& remote);
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enum State
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{
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eInitial,
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eConnecting,
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eLinkEstablished, // when utp connection is established
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eCryptoHandshake, // crypto handshake initiated
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eSessionReady, // session is ready
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eClose // utp connection is closed
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};
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llarp_router*
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Router();
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State state;
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void
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OnLinkEstablished(LinkLayer* p)
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{
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parent = p;
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EnterState(eLinkEstablished);
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llarp::LogDebug("link established with ", remoteAddr);
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}
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void
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EnterState(State st);
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BaseSession();
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~BaseSession();
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void
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PumpWrite()
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{
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if(!sock)
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return;
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ssize_t expect = 0;
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std::vector< utp_iovec > vecs;
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for(const auto& vec : vecq)
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{
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expect += vec.iov_len;
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vecs.push_back(vec);
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}
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if(expect)
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{
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ssize_t s = utp_writev(sock, vecs.data(), vecs.size());
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llarp::LogDebug("utp_writev wrote=", s, " expect=", expect,
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" to=", remoteAddr);
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while(s > vecq.front().iov_len)
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{
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s -= vecq.front().iov_len;
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vecq.pop_front();
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sendq.pop_front();
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}
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if(vecq.size())
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{
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auto& front = vecq.front();
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front.iov_len -= s;
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front.iov_base = ((byte_t*)front.iov_base) + s;
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}
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}
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/*
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while(sendq.size() > 0 && !stalled)
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{
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ssize_t expect = FragmentBufferSize - sendBufOffset;
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ssize_t s = write_ll(sendq.front().data() + sendBufOffset,
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expect); if(s != expect)
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{
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llarp::LogDebug("stalled at offset=", sendBufOffset, " sz=", s,
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" to ", remoteAddr);
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sendBufOffset += s;
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stalled = true;
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}
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else
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{
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sendBufOffset = 0;
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sendq.pop_front();
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}
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}
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*/
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}
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ssize_t
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write_ll(byte_t* buf, size_t sz)
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{
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if(sock == nullptr)
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{
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llarp::LogWarn("write_ll failed: no socket");
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return 0;
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}
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ssize_t s = utp_write(sock, buf, sz);
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llarp::LogDebug("write_ll ", s, " of ", sz, " bytes to ", remoteAddr);
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return s;
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}
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bool
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VerifyThenDecrypt(byte_t* buf);
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void
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EncryptThenHash(const byte_t* ptr, uint32_t sz, bool isLastFragment);
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bool
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QueueWriteBuffers(llarp_buffer_t buf)
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{
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if(sendq.size() >= MaxSendQueueSize)
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return false;
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llarp::LogDebug("write ", buf.sz, " bytes to ", remoteAddr);
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lastActive = llarp_time_now_ms();
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size_t sz = buf.sz;
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byte_t* ptr = buf.base;
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while(sz)
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{
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uint32_t s = std::min(FragmentBodyPayloadSize, sz);
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EncryptThenHash(ptr, s, ((sz - s) == 0));
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ptr += s;
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sz -= s;
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}
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return true;
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}
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void
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Connect()
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{
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utp_connect(sock, remoteAddr, remoteAddr.SockLen());
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EnterState(eConnecting);
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}
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void
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OutboundLinkEstablished(LinkLayer* p)
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{
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OnLinkEstablished(p);
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OutboundHandshake();
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}
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// send first message
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void
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OutboundHandshake();
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// mix keys
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bool
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DoKeyExchange(llarp_transport_dh_func dh, const KeyExchangeNonce& n,
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const PubKey& other, const SecretKey& secret)
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{
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ShortHash t_h;
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AlignedBuffer< 64 > tmp;
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memcpy(tmp.data(), sessionKey, sessionKey.size());
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memcpy(tmp.data() + sessionKey.size(), n, n.size());
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// t_h = HS(K + L.n)
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if(!Router()->crypto.shorthash(t_h, ConstBuffer(tmp)))
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{
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llarp::LogError("failed to mix key to ", remoteAddr);
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return false;
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}
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// K = TKE(a.p, B_a.e, sk, t_h)
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if(!dh(sessionKey, other, secret, t_h))
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{
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llarp::LogError("key exchange with ", other, " failed");
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return false;
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}
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llarp::LogDebug("keys mixed with session to ", remoteAddr);
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return true;
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}
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void
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TickImpl(llarp_time_t now)
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{
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}
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void
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Close();
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bool
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Recv(const void* buf, size_t sz)
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{
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Alive();
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byte_t* ptr = (byte_t*)buf;
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llarp::LogDebug("utp read ", sz, " from ", remoteAddr);
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size_t s = sz;
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// process leftovers
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if(recvBufOffset)
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{
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auto left = FragmentBufferSize - recvBufOffset;
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if(s >= left)
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{
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// yes it fills it
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llarp::LogDebug("process leftovers, offset=", recvBufOffset,
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" sz=", s, " left=", left);
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memcpy(recvBuf.data() + recvBufOffset, ptr, left);
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s -= left;
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recvBufOffset = 0;
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ptr += left;
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if(!VerifyThenDecrypt(recvBuf.data()))
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return false;
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}
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}
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// process full fragments
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while(s >= FragmentBufferSize)
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{
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recvBufOffset = 0;
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llarp::LogDebug("process full sz=", s);
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if(!VerifyThenDecrypt(ptr))
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return false;
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ptr += FragmentBufferSize;
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s -= FragmentBufferSize;
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}
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if(s)
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{
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// hold onto leftovers
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llarp::LogDebug("leftovers sz=", s);
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memcpy(recvBuf.data() + recvBufOffset, ptr, s);
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recvBufOffset += s;
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}
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return true;
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}
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bool
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InboundLIM(const LinkIntroMessage* msg);
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bool
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OutboundLIM(const LinkIntroMessage* msg);
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bool
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IsTimedOut(llarp_time_t now) const
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{
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if(state == eClose)
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return true;
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if(now < lastActive)
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return false;
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auto dlt = now - lastActive;
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if(dlt >= sessionTimeout)
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{
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llarp::LogDebug("session timeout reached for ", remoteAddr);
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return true;
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}
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return false;
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}
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const PubKey&
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RemotePubKey() const
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{
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return remoteRC.pubkey;
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}
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const Addr&
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RemoteEndpoint() const
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{
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return remoteAddr;
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}
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void
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MarkEstablished();
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}; // namespace utp
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struct LinkLayer : public ILinkLayer
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{
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utp_context* _utp_ctx = nullptr;
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llarp_router* router = nullptr;
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static uint64
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OnRead(utp_callback_arguments* arg);
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static uint64
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SendTo(utp_callback_arguments* arg)
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{
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LinkLayer* l =
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static_cast< LinkLayer* >(utp_context_get_userdata(arg->context));
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llarp::LogDebug("utp_sendto ", Addr(*arg->address), " ", arg->len,
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" bytes");
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if(::sendto(l->m_udp.fd, (char*)arg->buf, arg->len, arg->flags,
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arg->address, arg->address_len)
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== -1)
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{
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llarp::LogError("sendto failed: ", strerror(errno));
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}
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return 0;
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}
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static uint64
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OnError(utp_callback_arguments* arg)
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{
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BaseSession* session =
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static_cast< BaseSession* >(utp_get_userdata(arg->socket));
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if(session)
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{
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if(arg->error_code == UTP_ETIMEDOUT)
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{
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session->Router()->OnConnectTimeout(session->GetPubKey());
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}
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llarp::LogError(utp_error_code_names[arg->error_code], " via ",
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session->remoteAddr);
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session->Close();
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}
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return 0;
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}
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static uint64
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OnStateChange(utp_callback_arguments*);
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static uint64
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OnAccept(utp_callback_arguments*);
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static uint64
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OnLog(utp_callback_arguments* arg)
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{
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llarp::LogDebug(arg->buf);
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return 0;
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}
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LinkLayer(llarp_router* r) : ILinkLayer()
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{
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router = r;
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_utp_ctx = utp_init(2);
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utp_context_set_userdata(_utp_ctx, this);
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utp_set_callback(_utp_ctx, UTP_SENDTO, &LinkLayer::SendTo);
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utp_set_callback(_utp_ctx, UTP_ON_ACCEPT, &LinkLayer::OnAccept);
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utp_set_callback(_utp_ctx, UTP_ON_STATE_CHANGE,
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&LinkLayer::OnStateChange);
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utp_set_callback(_utp_ctx, UTP_ON_READ, &LinkLayer::OnRead);
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utp_set_callback(_utp_ctx, UTP_ON_ERROR, &LinkLayer::OnError);
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utp_set_callback(_utp_ctx, UTP_LOG, &LinkLayer::OnLog);
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utp_context_set_option(_utp_ctx, UTP_LOG_NORMAL, 1);
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utp_context_set_option(_utp_ctx, UTP_LOG_MTU, 1);
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utp_context_set_option(_utp_ctx, UTP_LOG_DEBUG, 1);
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utp_context_set_option(_utp_ctx, UTP_SNDBUF, MAX_LINK_MSG_SIZE * 16);
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utp_context_set_option(_utp_ctx, UTP_RCVBUF, MAX_LINK_MSG_SIZE * 64);
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}
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~LinkLayer()
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{
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utp_destroy(_utp_ctx);
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}
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uint16_t
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Rank() const
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{
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return 1;
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}
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void
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RecvFrom(const Addr& from, const void* buf, size_t sz)
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{
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utp_process_udp(_utp_ctx, (const byte_t*)buf, sz, from, from.SockLen());
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}
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#ifdef __linux__
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void
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ProcessICMP()
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{
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do
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{
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byte_t vec_buf[4096], ancillary_buf[4096];
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struct iovec iov = {vec_buf, sizeof(vec_buf)};
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struct sockaddr_in remote;
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struct msghdr msg;
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ssize_t len;
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struct cmsghdr* cmsg;
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struct sock_extended_err* e;
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struct sockaddr* icmp_addr;
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struct sockaddr_in* icmp_sin;
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memset(&msg, 0, sizeof(msg));
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msg.msg_name = &remote;
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msg.msg_namelen = sizeof(remote);
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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msg.msg_flags = 0;
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msg.msg_control = ancillary_buf;
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msg.msg_controllen = sizeof(ancillary_buf);
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len = recvmsg(m_udp.fd, &msg, MSG_ERRQUEUE | MSG_DONTWAIT);
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if(len < 0)
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{
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if(errno == EAGAIN || errno == EWOULDBLOCK)
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errno = 0;
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else
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llarp::LogError("failed to read icmp for utp ", strerror(errno));
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return;
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}
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for(cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg))
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{
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if(cmsg->cmsg_type != IP_RECVERR)
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{
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continue;
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}
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if(cmsg->cmsg_level != SOL_IP)
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{
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continue;
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}
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e = (struct sock_extended_err*)CMSG_DATA(cmsg);
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if(!e)
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continue;
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if(e->ee_origin != SO_EE_ORIGIN_ICMP)
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{
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continue;
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}
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icmp_addr = (struct sockaddr*)SO_EE_OFFENDER(e);
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icmp_sin = (struct sockaddr_in*)icmp_addr;
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if(icmp_sin->sin_port != 0)
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{
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continue;
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}
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if(e->ee_type == 3 && e->ee_code == 4)
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{
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utp_process_icmp_fragmentation(_utp_ctx, vec_buf, len,
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(struct sockaddr*)&remote,
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sizeof(remote), e->ee_info);
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}
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else
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{
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utp_process_icmp_error(_utp_ctx, vec_buf, len,
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(struct sockaddr*)&remote, sizeof(remote));
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}
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}
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} while(true);
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}
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#endif
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void
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Pump()
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{
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utp_issue_deferred_acks(_utp_ctx);
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#ifdef __linux__
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ProcessICMP();
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#endif
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std::set< PubKey > sessions;
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{
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Lock l(m_AuthedLinksMutex);
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auto itr = m_AuthedLinks.begin();
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while(itr != m_AuthedLinks.end())
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{
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sessions.insert(itr->first);
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++itr;
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}
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}
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ILinkLayer::Pump();
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{
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Lock l(m_AuthedLinksMutex);
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for(const auto& pk : sessions)
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{
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if(m_AuthedLinks.find(pk) == m_AuthedLinks.end())
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{
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// all sessions were removed
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router->SessionClosed(pk);
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}
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}
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}
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}
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void
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Stop()
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{
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}
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llarp_router*
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GetRouter();
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bool
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KeyGen(SecretKey& k)
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{
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router->crypto.encryption_keygen(k);
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return true;
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}
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void
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Tick(llarp_time_t now)
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{
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utp_check_timeouts(_utp_ctx);
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ILinkLayer::Tick(now);
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}
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ILinkSession*
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NewOutboundSession(const RouterContact& rc, const AddressInfo& addr);
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utp_socket*
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NewSocket()
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{
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return utp_create_socket(_utp_ctx);
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}
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const char*
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Name() const
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{
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return "utp";
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}
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};
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std::unique_ptr< ILinkLayer >
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NewServer(llarp_router* r)
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{
|
|
return std::unique_ptr< LinkLayer >(new LinkLayer(r));
|
|
}
|
|
|
|
BaseSession::BaseSession(LinkLayer* p)
|
|
{
|
|
parent = p;
|
|
remoteTransportPubKey.Zero();
|
|
recvMsgOffset = 0;
|
|
|
|
SendQueueBacklog = [&]() -> size_t { return sendq.size(); };
|
|
|
|
SendKeepAlive = [&]() -> bool {
|
|
auto now = llarp_time_now_ms();
|
|
if(sendq.size() == 0 && state == eSessionReady && now > lastActive
|
|
&& now - lastActive > (sessionTimeout / 4))
|
|
{
|
|
DiscardMessage msg;
|
|
byte_t tmp[128] = {0};
|
|
auto buf = llarp::StackBuffer< decltype(tmp) >(tmp);
|
|
if(!msg.BEncode(&buf))
|
|
return false;
|
|
buf.sz = buf.cur - buf.base;
|
|
buf.cur = buf.base;
|
|
if(!this->QueueWriteBuffers(buf))
|
|
return false;
|
|
}
|
|
return true;
|
|
};
|
|
gotLIM = false;
|
|
recvBufOffset = 0;
|
|
TimedOut = [&](llarp_time_t now) -> bool {
|
|
return this->IsTimedOut(now) || this->state == eClose;
|
|
};
|
|
GetPubKey = std::bind(&BaseSession::RemotePubKey, this);
|
|
lastActive = llarp_time_now_ms();
|
|
// Pump = []() {};
|
|
Pump = std::bind(&BaseSession::PumpWrite, this);
|
|
Tick = std::bind(&BaseSession::TickImpl, this, std::placeholders::_1);
|
|
SendMessageBuffer = std::bind(&BaseSession::QueueWriteBuffers, this,
|
|
std::placeholders::_1);
|
|
|
|
IsEstablished = [=]() {
|
|
return this->state == eSessionReady || this->state == eLinkEstablished;
|
|
};
|
|
|
|
SendClose = std::bind(&BaseSession::Close, this);
|
|
GetRemoteEndpoint = std::bind(&BaseSession::RemoteEndpoint, this);
|
|
}
|
|
|
|
BaseSession::BaseSession(LinkLayer* p, utp_socket* s,
|
|
const RouterContact& rc, const AddressInfo& addr)
|
|
: BaseSession(p)
|
|
{
|
|
remoteRC.Clear();
|
|
remoteTransportPubKey = addr.pubkey;
|
|
remoteRC = rc;
|
|
sock = s;
|
|
assert(utp_set_userdata(sock, this) == this);
|
|
assert(s == sock);
|
|
remoteAddr = addr;
|
|
Start = std::bind(&BaseSession::Connect, this);
|
|
GotLIM =
|
|
std::bind(&BaseSession::OutboundLIM, this, std::placeholders::_1);
|
|
}
|
|
|
|
BaseSession::BaseSession(LinkLayer* p, utp_socket* s, const Addr& addr)
|
|
: BaseSession(p)
|
|
{
|
|
p->router->crypto.shorthash(sessionKey,
|
|
InitBuffer(p->router->pubkey(), PUBKEYSIZE));
|
|
remoteRC.Clear();
|
|
sock = s;
|
|
assert(s == sock);
|
|
assert(utp_set_userdata(sock, this) == this);
|
|
remoteAddr = addr;
|
|
Start = []() {};
|
|
GotLIM = std::bind(&BaseSession::InboundLIM, this, std::placeholders::_1);
|
|
}
|
|
|
|
bool
|
|
BaseSession::InboundLIM(const LinkIntroMessage* msg)
|
|
{
|
|
if(gotLIM && remoteRC.pubkey != msg->rc.pubkey)
|
|
{
|
|
return false;
|
|
}
|
|
remoteRC = msg->rc;
|
|
gotLIM = true;
|
|
if(!DoKeyExchange(Router()->crypto.transport_dh_server, msg->N,
|
|
remoteRC.enckey, parent->TransportSecretKey()))
|
|
return false;
|
|
EnterState(eSessionReady);
|
|
return true;
|
|
}
|
|
|
|
bool
|
|
BaseSession::OutboundLIM(const LinkIntroMessage* msg)
|
|
{
|
|
if(gotLIM && remoteRC.pubkey != msg->rc.pubkey)
|
|
{
|
|
return false;
|
|
}
|
|
remoteRC = msg->rc;
|
|
gotLIM = true;
|
|
// TODO: update address info pubkey
|
|
return DoKeyExchange(Router()->crypto.transport_dh_client, msg->N,
|
|
remoteTransportPubKey, Router()->encryption);
|
|
}
|
|
|
|
void
|
|
BaseSession::OutboundHandshake()
|
|
{
|
|
// set session key
|
|
Router()->crypto.shorthash(sessionKey, ConstBuffer(remoteRC.pubkey));
|
|
|
|
byte_t tmp[LinkIntroMessage::MaxSize];
|
|
auto buf = StackBuffer< decltype(tmp) >(tmp);
|
|
// build our RC
|
|
LinkIntroMessage msg;
|
|
msg.rc = Router()->rc();
|
|
if(!msg.rc.VerifySignature(&Router()->crypto))
|
|
{
|
|
llarp::LogError("our RC is invalid? closing session to", remoteAddr);
|
|
Close();
|
|
return;
|
|
}
|
|
msg.N.Randomize();
|
|
msg.P = DefaultLinkSessionLifetime;
|
|
if(!msg.Sign(&Router()->crypto, Router()->identity))
|
|
{
|
|
llarp::LogError("failed to sign LIM for outbound handshake to ",
|
|
remoteAddr);
|
|
Close();
|
|
return;
|
|
}
|
|
// encode
|
|
if(!msg.BEncode(&buf))
|
|
{
|
|
llarp::LogError("failed to encode LIM for handshake to ", remoteAddr);
|
|
Close();
|
|
return;
|
|
}
|
|
// rewind
|
|
buf.sz = buf.cur - buf.base;
|
|
buf.cur = buf.base;
|
|
// send
|
|
if(!SendMessageBuffer(buf))
|
|
{
|
|
llarp::LogError("failed to send handshake to ", remoteAddr);
|
|
Close();
|
|
return;
|
|
}
|
|
// mix keys
|
|
if(!DoKeyExchange(Router()->crypto.transport_dh_client, msg.N,
|
|
remoteTransportPubKey, Router()->encryption))
|
|
{
|
|
llarp::LogError("failed to mix keys for outbound session to ",
|
|
remoteAddr);
|
|
Close();
|
|
return;
|
|
}
|
|
EnterState(eSessionReady);
|
|
}
|
|
|
|
llarp_router*
|
|
BaseSession::Router()
|
|
{
|
|
return parent->router;
|
|
}
|
|
|
|
BaseSession::~BaseSession()
|
|
{
|
|
if(sock)
|
|
{
|
|
utp_shutdown(sock, SHUT_RDWR);
|
|
utp_close(sock);
|
|
utp_set_userdata(sock, nullptr);
|
|
}
|
|
}
|
|
|
|
ILinkSession*
|
|
LinkLayer::NewOutboundSession(const RouterContact& rc,
|
|
const AddressInfo& addr)
|
|
{
|
|
return new BaseSession(this, utp_create_socket(_utp_ctx), rc, addr);
|
|
}
|
|
|
|
uint64
|
|
LinkLayer::OnRead(utp_callback_arguments* arg)
|
|
{
|
|
BaseSession* self =
|
|
static_cast< BaseSession* >(utp_get_userdata(arg->socket));
|
|
|
|
if(self)
|
|
{
|
|
if(self->state == BaseSession::eClose)
|
|
{
|
|
return 0;
|
|
}
|
|
if(!self->Recv(arg->buf, arg->len))
|
|
{
|
|
llarp::LogDebug("recv fail for ", self->remoteAddr);
|
|
self->Close();
|
|
return 0;
|
|
}
|
|
utp_read_drained(arg->socket);
|
|
}
|
|
else
|
|
{
|
|
llarp::LogWarn("utp_socket got data with no underlying session");
|
|
utp_close(arg->socket);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
uint64
|
|
LinkLayer::OnStateChange(utp_callback_arguments* arg)
|
|
{
|
|
LinkLayer* l =
|
|
static_cast< LinkLayer* >(utp_context_get_userdata(arg->context));
|
|
BaseSession* session =
|
|
static_cast< BaseSession* >(utp_get_userdata(arg->socket));
|
|
if(session)
|
|
{
|
|
if(arg->state == UTP_STATE_CONNECT)
|
|
{
|
|
if(session->state == BaseSession::eClose)
|
|
{
|
|
return 0;
|
|
}
|
|
session->OutboundLinkEstablished(l);
|
|
}
|
|
else if(arg->state == UTP_STATE_WRITABLE)
|
|
{
|
|
session->PumpWrite();
|
|
}
|
|
else if(arg->state == UTP_STATE_EOF)
|
|
{
|
|
llarp::LogDebug("got eof from ", session->remoteAddr);
|
|
session->Close();
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
uint64
|
|
LinkLayer::OnAccept(utp_callback_arguments* arg)
|
|
{
|
|
LinkLayer* self =
|
|
static_cast< LinkLayer* >(utp_context_get_userdata(arg->context));
|
|
Addr remote(*arg->address);
|
|
llarp::LogDebug("utp accepted from ", remote);
|
|
BaseSession* session = new BaseSession(self, arg->socket, remote);
|
|
self->PutSession(session);
|
|
session->OnLinkEstablished(self);
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
BaseSession::EncryptThenHash(const byte_t* ptr, uint32_t sz,
|
|
bool isLastFragment)
|
|
|
|
{
|
|
sendq.emplace_back();
|
|
auto& buf = sendq.back();
|
|
vecq.emplace_back();
|
|
auto& vec = vecq.back();
|
|
vec.iov_base = buf.data();
|
|
vec.iov_len = FragmentBufferSize;
|
|
llarp::LogDebug("encrypt then hash ", sz, " bytes last=", isLastFragment);
|
|
buf.Randomize();
|
|
byte_t* nonce = buf.data() + FragmentHashSize;
|
|
byte_t* body = nonce + FragmentNonceSize;
|
|
byte_t* base = body;
|
|
if(isLastFragment)
|
|
htobe32buf(body, 0);
|
|
else
|
|
htobe32buf(body, 1);
|
|
body += sizeof(uint32_t);
|
|
htobe32buf(body, sz);
|
|
body += sizeof(uint32_t);
|
|
memcpy(body, ptr, sz);
|
|
|
|
auto payload =
|
|
InitBuffer(base, FragmentBufferSize - FragmentOverheadSize);
|
|
|
|
// encrypt
|
|
Router()->crypto.xchacha20(payload, sessionKey, nonce);
|
|
|
|
payload.base = nonce;
|
|
payload.cur = payload.base;
|
|
payload.sz = FragmentBufferSize - FragmentHashSize;
|
|
// key'd hash
|
|
Router()->crypto.hmac(buf.data(), payload, sessionKey);
|
|
}
|
|
|
|
void
|
|
BaseSession::EnterState(State st)
|
|
{
|
|
state = st;
|
|
if(st == eSessionReady)
|
|
{
|
|
parent->MapAddr(remoteRC.pubkey, this);
|
|
Router()->HandleLinkSessionEstablished(remoteRC);
|
|
}
|
|
Alive();
|
|
}
|
|
|
|
bool
|
|
BaseSession::VerifyThenDecrypt(byte_t* buf)
|
|
{
|
|
llarp::LogDebug("verify then decrypt ", remoteAddr);
|
|
ShortHash digest;
|
|
|
|
auto hbuf = InitBuffer(buf + FragmentHashSize,
|
|
FragmentBufferSize - FragmentHashSize);
|
|
if(!Router()->crypto.hmac(digest.data(), hbuf, sessionKey))
|
|
{
|
|
llarp::LogError("keyed hash failed");
|
|
return false;
|
|
}
|
|
ShortHash expected(buf);
|
|
if(expected != digest)
|
|
{
|
|
llarp::LogError("Message Integrity Failed: got ", digest, " from ",
|
|
remoteAddr, " instead of ", expected);
|
|
llarp::DumpBuffer(InitBuffer(buf, FragmentBufferSize));
|
|
return false;
|
|
}
|
|
|
|
auto body = InitBuffer(buf + FragmentOverheadSize,
|
|
FragmentBufferSize - FragmentOverheadSize);
|
|
|
|
Router()->crypto.xchacha20(body, sessionKey, buf + FragmentHashSize);
|
|
|
|
uint32_t upper, lower;
|
|
if(!(llarp_buffer_read_uint32(&body, &upper)
|
|
&& llarp_buffer_read_uint32(&body, &lower)))
|
|
return false;
|
|
bool fragmentEnd = upper == 0;
|
|
llarp::LogDebug("fragment size ", lower, " from ", remoteAddr);
|
|
if(lower + recvMsgOffset > recvMsg.size())
|
|
{
|
|
llarp::LogError("Fragment too big: ", lower, " bytes");
|
|
return false;
|
|
}
|
|
memcpy(recvMsg.data() + recvMsgOffset, body.cur, lower);
|
|
recvMsgOffset += lower;
|
|
if(fragmentEnd)
|
|
{
|
|
// got a message
|
|
llarp::LogDebug("end of message from ", remoteAddr);
|
|
auto mbuf = InitBuffer(recvMsg.data(), recvMsgOffset);
|
|
if(!Router()->HandleRecvLinkMessageBuffer(this, mbuf))
|
|
{
|
|
llarp::LogWarn("failed to handle message from ", remoteAddr);
|
|
llarp::DumpBuffer(mbuf);
|
|
}
|
|
recvMsgOffset = 0;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void
|
|
BaseSession::Close()
|
|
{
|
|
if(state != eClose)
|
|
{
|
|
if(sock)
|
|
{
|
|
utp_shutdown(sock, SHUT_RDWR);
|
|
utp_close(sock);
|
|
llarp::LogDebug("utp_close ", remoteAddr);
|
|
utp_set_userdata(sock, nullptr);
|
|
}
|
|
}
|
|
EnterState(eClose);
|
|
sock = nullptr;
|
|
}
|
|
|
|
void
|
|
BaseSession::Alive()
|
|
{
|
|
lastActive = llarp_time_now_ms();
|
|
}
|
|
|
|
} // namespace utp
|
|
|
|
} // namespace llarp
|