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Code Issues Releases Activity

handle out-of-sequence tunnel fragments

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orignal 2014-09-10 21:31:32 -04:00
parent 5abd4021c4
commit 26c629a7d8
2 changed files with 65 additions and 13 deletions
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67
TunnelEndpoint.cpp
View File

@ -15,6 +15,8 @@ namespace tunnel
{ {
for (auto it: m_IncompleteMessages) for (auto it: m_IncompleteMessages)
i2p::DeleteI2NPMessage (it.second.data); i2p::DeleteI2NPMessage (it.second.data);
for (auto it: m_OutOfSequenceFragments)
i2p::DeleteI2NPMessage (it.second.data);
} }
void TunnelEndpoint::HandleDecryptedTunnelDataMsg (I2NPMessage * msg) void TunnelEndpoint::HandleDecryptedTunnelDataMsg (I2NPMessage * msg)
@ -120,6 +122,7 @@ namespace tunnel
{ {
m.nextFragmentNum = 1; m.nextFragmentNum = 1;
m_IncompleteMessages[msgID] = m; m_IncompleteMessages[msgID] = m;
HandleOutOfSequenceFragment (msgID, m);
} }
else else
{ {
@ -148,40 +151,78 @@ namespace tunnel
auto it = m_IncompleteMessages.find (msgID); auto it = m_IncompleteMessages.find (msgID);
if (it != m_IncompleteMessages.end()) if (it != m_IncompleteMessages.end())
{ {
if (m.nextFragmentNum == it->second.nextFragmentNum) auto& msg = it->second;
if (m.nextFragmentNum == msg.nextFragmentNum)
{ {
I2NPMessage * incompleteMessage = it->second.data; if (msg.data->len + size < I2NP_MAX_MESSAGE_SIZE) // check if messega is not too long
if (incompleteMessage->len + size < I2NP_MAX_MESSAGE_SIZE) // check if messega is not too long
{ {
memcpy (incompleteMessage->buf + incompleteMessage->len, fragment, size); // concatenate fragment memcpy (msg.data->buf + msg.data->len, fragment, size); // concatenate fragment
incompleteMessage->len += size; msg.data->len += size;
if (isLastFragment) if (isLastFragment)
{ {
// message complete // message complete
HandleNextMessage (it->second); HandleNextMessage (msg);
m_IncompleteMessages.erase (it); m_IncompleteMessages.erase (it);
} }
else else
it->second.nextFragmentNum++; {
msg.nextFragmentNum++;
HandleOutOfSequenceFragment (msgID, msg);
}
} }
else else
{ {
LogPrint ("Fragment ", m.nextFragmentNum, " of message ", msgID, "exceeds max I2NP message size. Message dropped"); LogPrint ("Fragment ", m.nextFragmentNum, " of message ", msgID, "exceeds max I2NP message size. Message dropped");
i2p::DeleteI2NPMessage (it->second.data); i2p::DeleteI2NPMessage (msg.data);
m_IncompleteMessages.erase (it); m_IncompleteMessages.erase (it);
} }
i2p::DeleteI2NPMessage (m.data);
} }
else else
{ {
LogPrint ("Unexpected fragment ", m.nextFragmentNum, " instead ", it->second.nextFragmentNum, " of message ", msgID, ". Discarded"); LogPrint ("Unexpected fragment ", (int)m.nextFragmentNum, " instead ", (int)msg.nextFragmentNum, " of message ", msgID, ". Saved");
i2p::DeleteI2NPMessage (it->second.data); AddOutOfSequenceFragment (msgID, m.nextFragmentNum, isLastFragment, m.data);
m_IncompleteMessages.erase (it); // TODO: store unexpected fragment for a while
} }
} }
else else
LogPrint ("First fragment of message ", msgID, " not found. Discarded"); {
LogPrint ("First fragment of message ", msgID, " not found. Saved");
AddOutOfSequenceFragment (msgID, m.nextFragmentNum, isLastFragment, m.data);
}
}
i2p::DeleteI2NPMessage (m.data); void TunnelEndpoint::AddOutOfSequenceFragment (uint32_t msgID, uint8_t fragmentNum, bool isLastFragment, I2NPMessage * data)
{
auto it = m_OutOfSequenceFragments.find (msgID);
if (it == m_OutOfSequenceFragments.end ())
m_OutOfSequenceFragments.insert (std::pair<uint32_t, Fragment> (msgID, {fragmentNum, isLastFragment, data}));
else
i2p::DeleteI2NPMessage (data);
}
void TunnelEndpoint::HandleOutOfSequenceFragment (uint32_t msgID, TunnelMessageBlockEx& msg)
{
auto it = m_OutOfSequenceFragments.find (msgID);
if (it != m_OutOfSequenceFragments.end ())
{
if (it->second.fragmentNum == msg.nextFragmentNum)
{
LogPrint ("Out-of-sequence fragment ", (int)it->second.fragmentNum, " of message ", msgID, " found");
auto size = it->second.data->GetLength ();
memcpy (msg.data->buf + msg.data->len, it->second.data->GetBuffer (), size); // concatenate out-of-sync fragment
msg.data->len += size;
if (it->second.isLastFragment)
{
// message complete
HandleNextMessage (msg);
m_IncompleteMessages.erase (msgID);
}
else
msg.nextFragmentNum++;
i2p::DeleteI2NPMessage (it->second.data);
m_OutOfSequenceFragments.erase (it);
}
}
} }
void TunnelEndpoint::HandleNextMessage (const TunnelMessageBlock& msg) void TunnelEndpoint::HandleNextMessage (const TunnelMessageBlock& msg)

11
TunnelEndpoint.h
View File

@ -17,6 +17,13 @@ namespace tunnel
{ {
uint8_t nextFragmentNum; uint8_t nextFragmentNum;
}; };
struct Fragment
{
uint8_t fragmentNum;
bool isLastFragment;
I2NPMessage * data;
};
public: public:
@ -30,10 +37,14 @@ namespace tunnel
void HandleFollowOnFragment (uint32_t msgID, bool isLastFragment, const TunnelMessageBlockEx& m); void HandleFollowOnFragment (uint32_t msgID, bool isLastFragment, const TunnelMessageBlockEx& m);
void HandleNextMessage (const TunnelMessageBlock& msg); void HandleNextMessage (const TunnelMessageBlock& msg);
void AddOutOfSequenceFragment (uint32_t msgID, uint8_t fragmentNum, bool isLastFragment, I2NPMessage * data);
void HandleOutOfSequenceFragment (uint32_t msgID, TunnelMessageBlockEx& msg);
private: private:
std::map<uint32_t, TunnelMessageBlockEx> m_IncompleteMessages; std::map<uint32_t, TunnelMessageBlockEx> m_IncompleteMessages;
std::map<uint32_t, Fragment> m_OutOfSequenceFragments;
bool m_IsInbound; bool m_IsInbound;
size_t m_NumReceivedBytes; size_t m_NumReceivedBytes;
}; };