1 files changed, 46 insertions, 269 deletions

diff --git a/indra/llmessage/llpacketring.cpp b/indra/llmessage/llpacketring.cpp
index b8284334ea..bade413e61 100644
--- a/indra/llmessage/llpacketring.cpp
+++ b/indra/llmessage/llpacketring.cpp
@@ -28,344 +28,121 @@
 
 #include "llpacketring.h"
 
-#if LL_WINDOWS
-    #include <winsock2.h>
-#else
-    #include <sys/socket.h>
-    #include <netinet/in.h>
-#endif
-
-// linden library includes
 #include "llerror.h"
-#include "lltimer.h"
-#include "llproxy.h"
-#include "llrand.h"
-#include "message.h"
-#include "u64.h"
 
-constexpr S16 MAX_BUFFER_RING_SIZE = 1024;
+constexpr S16 MAX_BUFFER_RING_SIZE     = 8192;
+
+// DANGER: don't adjust DEFAULT_BUFFER_RING_SIZE unless you know what
+// you're doing.  Its value affects the "buffer load rate" which is used
+// to supply backpressure to an overloaded nework queue.
 constexpr S16 DEFAULT_BUFFER_RING_SIZE = 256;
 
-LLPacketRing::LLPacketRing ()
-    : mPacketRing(DEFAULT_BUFFER_RING_SIZE, nullptr)
+LLPacketRing::LLPacketRing()
+    : mRing(DEFAULT_BUFFER_RING_SIZE, nullptr)
 {
     LLHost invalid_host;
-    for (size_t i = 0; i < mPacketRing.size(); ++i)
+    for (size_t i = 0; i < mRing.size(); ++i)
     {
-        mPacketRing[i] = new LLPacketBuffer(invalid_host, nullptr, 0);
+        mRing[i] = new LLPacketBuffer(invalid_host, nullptr, 0);
     }
 }
 
-LLPacketRing::~LLPacketRing ()
+LLPacketRing::~LLPacketRing()
 {
-    for (auto packet : mPacketRing)
+    for (auto* packet : mRing)
     {
         delete packet;
     }
-    mPacketRing.clear();
+    mRing.clear();
     mNumBufferedPackets = 0;
     mNumBufferedBytes = 0;
     mHeadIndex = 0;
 }
 
-S32 LLPacketRing::receivePacket (S32 socket, char *datap)
-{
-    bool drop = computeDrop();
-    return (mNumBufferedPackets > 0) ?
-        receiveOrDropBufferedPacket(datap, drop) :
-        receiveOrDropPacket(socket, datap, drop);
-}
-
-bool send_packet_helper(int socket, const char * datap, S32 data_size, LLHost host)
-{
-    if (!LLProxy::isSOCKSProxyEnabled())
-    {
-        return send_packet(socket, datap, data_size, host.getAddress(), host.getPort());
-    }
-
-    char headered_send_buffer[NET_BUFFER_SIZE + SOCKS_HEADER_SIZE];
-
-    proxywrap_t *socks_header = static_cast<proxywrap_t*>(static_cast<void*>(&headered_send_buffer));
-    socks_header->rsv   = 0;
-    socks_header->addr  = host.getAddress();
-    socks_header->port  = htons(host.getPort());
-    socks_header->atype = ADDRESS_IPV4;
-    socks_header->frag  = 0;
-
-    memcpy(headered_send_buffer + SOCKS_HEADER_SIZE, datap, data_size);
-
-    return send_packet( socket,
-                        headered_send_buffer,
-                        data_size + SOCKS_HEADER_SIZE,
-                        LLProxy::getInstance()->getUDPProxy().getAddress(),
-                        LLProxy::getInstance()->getUDPProxy().getPort());
-}
-
-bool LLPacketRing::sendPacket(int socket, const char * datap, S32 data_size, LLHost host)
+void LLPacketRing::pushPacket(const LLPacketBuffer& packet)
 {
-    mActualBytesOut += data_size;
-    return send_packet_helper(socket, datap, data_size, host);
-}
-
-void LLPacketRing::dropPackets (U32 num_to_drop)
-{
-    mPacketsToDrop += num_to_drop;
-}
-
-void LLPacketRing::setDropPercentage (F32 percent_to_drop)
-{
-    mDropPercentage = percent_to_drop;
-}
-
-bool LLPacketRing::computeDrop()
-{
-    bool drop= (mDropPercentage > 0.0f && (ll_frand(100.f) < mDropPercentage));
-    if (drop)
-    {
-        ++mPacketsToDrop;
-    }
-    if (mPacketsToDrop > 0)
-    {
-        --mPacketsToDrop;
-        drop = true;
-    }
-    return drop;
-}
-
-S32 LLPacketRing::receiveOrDropPacket(S32 socket, char *datap, bool drop)
-{
-    S32 packet_size = 0;
-
-    // pull straight from socket
-    if (LLProxy::isSOCKSProxyEnabled())
+    S16 ring_size = (S16)mRing.size();
+    if (mNumBufferedPackets >= ring_size && ring_size < MAX_BUFFER_RING_SIZE)
     {
-        char buffer[NET_BUFFER_SIZE + SOCKS_HEADER_SIZE];   /* Flawfinder ignore */
-        packet_size = receive_packet(socket, buffer);
-        if (packet_size > 0)
-        {
-            mActualBytesIn += packet_size;
-        }
-
-        if (packet_size > SOCKS_HEADER_SIZE)
-        {
-            if (drop)
-            {
-                packet_size = 0;
-            }
-            else
-            {
-                // *FIX We are assuming ATYP is 0x01 (IPv4), not 0x03 (hostname) or 0x04 (IPv6)
-                packet_size -= SOCKS_HEADER_SIZE; // The unwrapped packet size
-                memcpy(datap, buffer + SOCKS_HEADER_SIZE, packet_size);
-                proxywrap_t * header = static_cast<proxywrap_t*>(static_cast<void*>(buffer));
-                mLastSender.setAddress(header->addr);
-                mLastSender.setPort(ntohs(header->port));
-                mLastReceivingIF = ::get_receiving_interface();
-            }
-        }
-        else
-        {
-            packet_size = 0;
-        }
-    }
-    else
-    {
-        packet_size = receive_packet(socket, datap);
-        if (packet_size > 0)
-        {
-            mActualBytesIn += packet_size;
-            if (drop)
-            {
-                packet_size = 0;
-            }
-            else
-            {
-                mLastSender = ::get_sender();
-                mLastReceivingIF = ::get_receiving_interface();
-            }
-        }
+        expandRing();
+        ring_size = (S16)mRing.size();
     }
-    return packet_size;
-}
 
-S32 LLPacketRing::receiveOrDropBufferedPacket(char *datap, bool drop)
-{
-    assert(mNumBufferedPackets > 0);
-    S32 packet_size = 0;
+    LLPacketBuffer* slot = mRing[mHeadIndex];
+    S32 old_size = slot->getSize();
 
-    S16 ring_size = (S16)(mPacketRing.size());
-    S16 packet_index = (mHeadIndex + ring_size - mNumBufferedPackets) % ring_size;
-    LLPacketBuffer* packet = mPacketRing[packet_index];
-    packet_size = packet->getSize();
-    mLastSender = packet->getHost();
-    mLastReceivingIF = packet->getReceivingInterface();
+    *slot = packet;
 
-    --mNumBufferedPackets;
-    mNumBufferedBytes -= packet_size;
-    if (mNumBufferedPackets == 0)
-    {
-        assert(mNumBufferedBytes == 0);
-    }
+    mHeadIndex = (mHeadIndex + 1) % ring_size;
 
-    if (!drop)
+    if (mNumBufferedPackets < ring_size)
     {
-        if (packet_size > 0)
-        {
-            memcpy(datap, packet->getData(), packet_size);
-        }
-        else
-        {
-            assert(false);
-        }
+        ++mNumBufferedPackets;
+        mNumBufferedBytes += packet.getSize();
     }
     else
     {
-        packet_size = 0;
+        // Ring is at maximum capacity; oldest packet was overwritten.
+        // This is VERY BAD because we've already ACKed the packet we're loosing
+        // (if it was "reliable").
+        LL_WARNS("PacketRing") << "buffer overflow at " << mNumBufferedPackets << " packets" << LL_ENDL;
+        mNumBufferedBytes += packet.getSize() - old_size;
     }
-    return packet_size;
 }
 
-S32 LLPacketRing::bufferInboundPacket(S32 socket)
+bool LLPacketRing::popPacket(LLPacketBuffer& packet)
 {
-    if (mNumBufferedPackets == mPacketRing.size() && mNumBufferedPackets < MAX_BUFFER_RING_SIZE)
+    if (mNumBufferedPackets <= 0)
     {
-        expandRing();
+        return false;
     }
 
-    LLPacketBuffer* packet = mPacketRing[mHeadIndex];
-    S32 old_packet_size = packet->getSize();
-    S32 packet_size = 0;
-    if (LLProxy::isSOCKSProxyEnabled())
-    {
-        char buffer[NET_BUFFER_SIZE + SOCKS_HEADER_SIZE];   /* Flawfinder ignore */
-        packet_size = receive_packet(socket, buffer);
-        if (packet_size > 0)
-        {
-            mActualBytesIn += packet_size;
-            if (packet_size > SOCKS_HEADER_SIZE)
-            {
-                // *FIX We are assuming ATYP is 0x01 (IPv4), not 0x03 (hostname) or 0x04 (IPv6)
+    S16 ring_size  = (S16)mRing.size();
+    S16 tail_index = (mHeadIndex + ring_size - mNumBufferedPackets) % ring_size;
 
-                proxywrap_t * header = static_cast<proxywrap_t*>(static_cast<void*>(buffer));
-                LLHost sender;
-                sender.setAddress(header->addr);
-                sender.setPort(ntohs(header->port));
+    LLPacketBuffer* slot = mRing[tail_index];
+    S32 packet_size = slot->getSize();
 
-                packet_size -= SOCKS_HEADER_SIZE; // The unwrapped packet size
-                packet->init(buffer + SOCKS_HEADER_SIZE, packet_size, sender);
+    packet = *slot;
 
-                mHeadIndex = (mHeadIndex + 1) % (S16)(mPacketRing.size());
-                if (mNumBufferedPackets < MAX_BUFFER_RING_SIZE)
-                {
-                    ++mNumBufferedPackets;
-                    mNumBufferedBytes += packet_size;
-                }
-                else
-                {
-                    // we overwrote an older packet
-                    mNumBufferedBytes += packet_size - old_packet_size;
-                }
-            }
-            else
-            {
-                packet_size = 0;
-            }
-        }
-    }
-    else
-    {
-        packet->init(socket);
-        packet_size = packet->getSize();
-        if (packet_size > 0)
-        {
-            mActualBytesIn += packet_size;
+    --mNumBufferedPackets;
+    mNumBufferedBytes -= packet_size;
 
-            mHeadIndex = (mHeadIndex + 1) % (S16)(mPacketRing.size());
-            if (mNumBufferedPackets < MAX_BUFFER_RING_SIZE)
-            {
-                ++mNumBufferedPackets;
-                mNumBufferedBytes += packet_size;
-            }
-            else
-            {
-                // we overwrote an older packet
-                mNumBufferedBytes += packet_size - old_packet_size;
-            }
-        }
-    }
-    return packet_size;
-}
+    llassert(mNumBufferedPackets > 0 || mNumBufferedBytes == 0);
 
-S32 LLPacketRing::drainSocket(S32 socket)
-{
-    // drain into buffer
-    S32 packet_size = 1;
-    S32 num_loops = 0;
-    S32 old_num_packets = mNumBufferedPackets;
-    while (packet_size > 0)
-    {
-        packet_size = bufferInboundPacket(socket);
-        ++num_loops;
-    }
-    S32 num_dropped_packets = (num_loops - 1 + old_num_packets) - mNumBufferedPackets;
-    if (num_dropped_packets > 0)
-    {
-        // It will eventually be accounted by mDroppedPackets
-        // and mPacketsLost, but track it here for logging purposes.
-        mNumDroppedPackets += num_dropped_packets;
-    }
-    return (S32)(mNumBufferedPackets);
+    return true;
 }
 
 bool LLPacketRing::expandRing()
 {
-    // compute larger size
-    constexpr S16 BUFFER_RING_EXPANSION = 256;
-    S16 old_size = (S16)(mPacketRing.size());
+    constexpr S16 BUFFER_RING_EXPANSION = 512;
+    S16 old_size = (S16)mRing.size();
     S16 new_size = llmin(old_size + BUFFER_RING_EXPANSION, MAX_BUFFER_RING_SIZE);
     if (new_size == old_size)
     {
-        // mPacketRing is already maxed out
         return false;
     }
 
-    // make a larger ring and copy packet pointers
+    // Lay existing entries out linearly in FIFO order starting at index 0.
     std::vector<LLPacketBuffer*> new_ring(new_size, nullptr);
     for (S16 i = 0; i < old_size; ++i)
     {
         S16 j = (mHeadIndex + i) % old_size;
-        new_ring[i] = mPacketRing[j];
+        new_ring[i] = mRing[j];
     }
 
-    // allocate new packets for the remainder of new_ring
     LLHost invalid_host;
     for (S16 i = old_size; i < new_size; ++i)
     {
         new_ring[i] = new LLPacketBuffer(invalid_host, nullptr, 0);
     }
 
-    // swap the rings and reset mHeadIndex
-    mPacketRing.swap(new_ring);
+    mRing.swap(new_ring);
     mHeadIndex = mNumBufferedPackets;
     return true;
 }
 
 F32 LLPacketRing::getBufferLoadRate() const
 {
-    // goes up to MAX_BUFFER_RING_SIZE
     return (F32)mNumBufferedPackets / (F32)DEFAULT_BUFFER_RING_SIZE;
 }
-
-void LLPacketRing::dumpPacketRingStats()
-{
-    mNumDroppedPacketsTotal += mNumDroppedPackets;
-    LL_INFOS("Messaging") << "Packet ring stats: " << std::endl
-                          << "Buffered packets: " << mNumBufferedPackets << std::endl
-                          << "Buffered bytes: " << mNumBufferedBytes << std::endl
-                          << "Dropped packets current: " << mNumDroppedPackets << std::endl
-                          << "Dropped packets total: " << mNumDroppedPacketsTotal << std::endl
-                          << "Dropped packets percentage: " << mDropPercentage << "%" << std::endl
-                          << "Actual in bytes: " << mActualBytesIn << std::endl
-                          << "Actual out bytes: " << mActualBytesOut << LL_ENDL;
-    mNumDroppedPackets = 0;
-}