Bug 1915369 - track bytes sent and received when using quinn-udp r=necko-reviewers,valentin

An `nsIUDPSocket` tracks the number of bytes sent and received through its
methods, e.g. `RecvWithAddr`. The number of bytes is then displayed in
about:networking#sockets.

With `network.http.http3.use_nspr_for_io` set to `false` `Http3Session` uses
`quinn-udp` instead of `NSPR` for HTTP/3 QUIC UDP IO. Thus it does not use
`nsIUDPSocket` `RecvWithAddr`, but instead optains a raw file descriptor via
`nsIUDPSocket` `GetFileDescriptor` and then does its IO directly. Thereby the
number of bytes sent and received in `nsIUDPSocket` are not updated, i.e. stay
at `0`.

This commit exposes two new methods in `nsIUDPSocket`, namely `addOutputBytes`
and `addInputBytes` which are each called after any IO operation on the raw file
descriptor optained through `nsIUDPSocket` `GetFileDescriptor`.

Differential Revision: https://phabricator.services.mozilla.com/D220379

netwerk/base/nsIUDPSocket.idl

@@ -255,14 +255,38 @@ interface nsIUDPSocket : nsISupports
                                        [const, optional] in NetAddrPtr iface);
 
     /**
-    * getFileDescriptor
-    *
-    * Get the file descriptor of the socket.
-    *
-    * @return The file descriptor.
-    */
+      * getFileDescriptor
+      *
+      * Get the file descriptor of the socket.
+      *
+      * @return The file descriptor.
+      */
     [noscript, notxpcom] int64_t getFileDescriptor();
 
+    /**
+     * addOutputBytes
+     *
+     * Add number of bytes written to the socket. Used when sending data through
+     * file descriptor optained from getFileDescriptor instead of nsIUDPSocket
+     * methods.
+     *
+     * @param aBytes
+     *        The number of bytes written.
+     */
+    [noscript, notxpcom] void addOutputBytes(in uint32_t aBytes);
+
+    /**
+     * addInputBytes
+     *
+     * Add number of bytes read from the socket. Used when reading data through
+     * file descriptor optained from getFileDescriptor instead of nsIUDPSocket
+     * methods.
+     *
+     * @param aBytes
+     *        The number of bytes read.
+     */
+    [noscript, notxpcom] void addInputBytes(in uint32_t aBytes);
+
     /**
      * multicastLoopback
      *

netwerk/base/nsUDPSocket.cpp

@@ -257,11 +257,16 @@ nsUDPSocket::nsUDPSocket() {
 
 nsUDPSocket::~nsUDPSocket() { CloseSocket(); }
 
-void nsUDPSocket::AddOutputBytes(int32_t aBytes) {
+void nsUDPSocket::AddOutputBytes(uint32_t aBytes) {
   mByteWriteCount += aBytes;
   profiler_count_bandwidth_written_bytes(aBytes);
 }
 
+void nsUDPSocket::AddInputBytes(uint32_t aBytes) {
+  mByteReadCount += aBytes;
+  profiler_count_bandwidth_read_bytes(aBytes);
+}
+
 void nsUDPSocket::OnMsgClose() {
   UDPSOCKET_LOG(("nsUDPSocket::OnMsgClose [this=%p]\n", this));
 
@@ -430,8 +435,7 @@ void nsUDPSocket::OnSocketReady(PRFileDesc* fd, int16_t outFlags) {
         ("nsUDPSocket::OnSocketReady: PR_RecvFrom failed [this=%p]\n", this));
     return;
   }
-  mByteReadCount += count;
-  profiler_count_bandwidth_read_bytes(count);
+  this->AddInputBytes(count);
 
   FallibleTArray<uint8_t> data;
   if (!data.AppendElements(buff, count, fallible)) {
@@ -1238,8 +1242,8 @@ nsUDPSocket::RecvWithAddr(NetAddr* addr, nsTArray<uint8_t>& aData) {
         ("nsUDPSocket::RecvWithAddr: PR_RecvFrom failed [this=%p]\n", this));
     return NS_OK;
   }
-  mByteReadCount += count;
-  profiler_count_bandwidth_read_bytes(count);
+
+  this->AddInputBytes(count);
   PRNetAddrToNetAddr(&prAddr, addr);
 
   if (!aData.AppendElements(buff, count, fallible)) {

netwerk/base/nsUDPSocket.h

@@ -34,8 +34,6 @@ class nsUDPSocket final : public nsASocketHandler, public nsIUDPSocket {
   uint64_t ByteCountSent() override { return mByteWriteCount; }
   uint64_t ByteCountReceived() override { return mByteReadCount; }
 
-  void AddOutputBytes(int32_t aBytes);
-
   nsUDPSocket();
 
  private:

netwerk/protocol/http/Http3Session.cpp

@@ -429,6 +429,7 @@ nsresult Http3Session::ProcessInput(nsIUDPSocket* socket) {
     return rv.result;
   }
   mTotalBytesRead += rv.bytes_read;
+  socket->AddInputBytes(rv.bytes_read);
 
   return NS_OK;
 }
@@ -982,6 +983,7 @@ nsresult Http3Session::ProcessOutput(nsIUDPSocket* socket) {
   if (rv.bytes_written != 0) {
     mTotalBytesWritten += rv.bytes_written;
     mLastWriteTime = PR_IntervalNow();
+    socket->AddOutputBytes(rv.bytes_written);
   }
 
   return NS_OK;