From e537878b8abee59317cac24a38bfe7291e7c471a Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Mon, 25 Jul 2022 13:42:59 -0400
Subject: [PATCH] check Ack block bufer size and shrink ranges if necessary
---
libi2pd/SSU2Session.cpp | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/libi2pd/SSU2Session.cpp b/libi2pd/SSU2Session.cpp
index afa38df7..8a67d9ca 100644
--- a/libi2pd/SSU2Session.cpp
+++ b/libi2pd/SSU2Session.cpp
@@ -2055,6 +2055,8 @@ namespace transport
size_t SSU2Session::CreateAckBlock (uint8_t * buf, size_t len)
{
if (len < 8) return 0;
+ int maxNumRanges = (len - 8) >> 1;
+ if (maxNumRanges > SSU2_MAX_NUM_ACK_RANGES) maxNumRanges = SSU2_MAX_NUM_ACK_RANGES;
buf[0] = eSSU2BlkAck;
uint32_t ackThrough = m_OutOfSequencePackets.empty () ? m_ReceivePacketNum : *m_OutOfSequencePackets.rbegin ();
htobe32buf (buf + 3, ackThrough); // Ack Through
@@ -2078,9 +2080,9 @@ namespace transport
{
auto d = std::div (acnt - 255, 255);
acnt = 255;
- if (d.quot > SSU2_MAX_NUM_ACK_RANGES)
+ if (d.quot > maxNumRanges)
{
- d.quot = SSU2_MAX_NUM_ACK_RANGES;
+ d.quot = maxNumRanges;
d.rem = 0;
}
// Acks only ragnes for acnt
@@ -2095,12 +2097,12 @@ namespace transport
numRanges++;
}
}
- while (it != m_OutOfSequencePackets.rend () && numRanges < SSU2_MAX_NUM_ACK_RANGES)
+ while (it != m_OutOfSequencePackets.rend () && numRanges < maxNumRanges)
{
if (lastNum - (*it) > 255)
{
// NACKs only ranges
- if (lastNum > (*it) + 255*(SSU2_MAX_NUM_ACK_RANGES - numRanges)) break; // too many NACKs
+ if (lastNum > (*it) + 255*(maxNumRanges - numRanges)) break; // too many NACKs
while (lastNum - (*it) > 255)
{
buf[8 + numRanges*2] = 255; buf[8 + numRanges*2 + 1] = 0; // NACKs 255, Acks 0
@@ -2124,13 +2126,13 @@ namespace transport
numAcks -= 255;
numRanges++;
buf[8 + numRanges*2] = 0; // NACKs 0
- if (numRanges >= SSU2_MAX_NUM_ACK_RANGES) break;
+ if (numRanges >= maxNumRanges) break;
}
if (numAcks > 255) numAcks = 255;
buf[8 + numRanges*2 + 1] = (uint8_t)numAcks; // Acks
numRanges++;
}
- if (numRanges < SSU2_MAX_NUM_ACK_RANGES && it == m_OutOfSequencePackets.rend ())
+ if (numRanges < maxNumRanges && it == m_OutOfSequencePackets.rend ())
{
// add range between out-of-seqence and received
int nacks = *m_OutOfSequencePackets.begin () - m_ReceivePacketNum - 1;