From 87d76df1720e29e4195cf4a8845c07450fb3b2f2 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Tue, 1 Aug 2023 11:38:26 -0700
Subject: Fixed issues around disconnected sockets.

We were bailing out when sockets closed, that was silly.
---
 src/stable/server.cpp  | 97 ++++++++++++++++++++++++++++++++++----------------
 src/stable/server.h    |  2 +-
 src/stable/sockettcp.h |  7 ++++
 3 files changed, 75 insertions(+), 31 deletions(-)

(limited to 'src/stable')

diff --git a/src/stable/server.cpp b/src/stable/server.cpp
index 3aa8a34..6ee7d6e 100644
--- a/src/stable/server.cpp
+++ b/src/stable/server.cpp
@@ -247,6 +247,8 @@ void Bu::Server::addClient( const Bu::ServerSocket *pSrv, Bu::Socket *pSocket )
 Bu::Client *Bu::Server::getClient( fd iId )
 {
     Bu::MutexLocker l( mClients );
+    if( !hClients.has( iId ) )
+        return NULL;
     return hClients.get( iId );
 }
 
@@ -520,30 +522,38 @@ void Bu::Server::IoWorker::handleRead( Client *pClient, Socket *pSocket )
     Bu::size iTotal=0;
 
     BU_PROFILE_START("client.read");
-    for(;;)
+    try
     {
-        try
+        for(;;)
         {
-            iRead = pSocket->read( buf, RBS );
-
-            if( iRead == 0 )
+            try
             {
-                break;
+                iRead = pSocket->read( buf, RBS );
+
+                if( iRead == 0 )
+                {
+                    break;
+                }
+                else
+                {
+                    iTotal += iRead;
+                    pClient->cbBuffer.server().write( buf, iRead );
+                    if( !pSocket->canRead() )
+                        break;
+                }
             }
-            else
+            catch( Bu::ExceptionBase &e )
             {
-                iTotal += iRead;
-                pClient->cbBuffer.server().write( buf, iRead );
-                if( !pSocket->canRead() )
-                    break;
+                pClient->disconnect();
+                //close( pSocket );
+                return;
             }
         }
-        catch( Bu::ExceptionBase &e )
-        {
-            pClient->disconnect();
-            //close( pSocket );
-            return;
-        }
+    }
+    catch( std::exception &e )
+    {
+        // Probably the socket is dead. We should maybe disconnect, but we'll
+        // also notice soon enough anyway?
     }
     BU_PROFILE_END("client.read");
 
@@ -565,12 +575,28 @@ void Bu::Server::IoWorker::handleRead( Client *pClient, Socket *pSocket )
 void Bu::Server::IoWorker::handleWrite( Client *pClient, Socket *pSocket )
 {
     char buf[RBS];
-    while( pClient->hasOutput() > 0 )
+    try
+    {
+        while( pClient->hasOutput() )
+        {
+            int iAmnt = RBS;
+            iAmnt = pClient->cbBuffer.server().peek( buf, iAmnt );
+            int iReal = pSocket->write( buf, iAmnt );
+            pClient->cbBuffer.server().seek( iReal );
+            if( iReal < iAmnt )
+            {
+                // We wrote less than expected, the kernel buffer must be full,
+                // we should queue ourselves again.
+                rSrv.clientWriteReady( pClient->getId() );
+                break;
+            }
+        }
+    }
+    catch( std::exception &e )
     {
-        int iAmnt = RBS;
-        iAmnt = pClient->cbBuffer.server().peek( buf, iAmnt );
-        int iReal = pSocket->write( buf, iAmnt );
-        pClient->cbBuffer.server().seek( iReal );
+        // Error working with socket, it's probably closed.
+        if( pClient->hasOutput() )
+            rSrv.clientWriteReady( pClient->getId() );
     }
 }
 
@@ -596,17 +622,28 @@ void Bu::Server::ClientWorker::run()
         if( pEv == NULL )
             continue;
 
-        Client *pClient = rSrv.getClient( pEv->getId() );
-        if( pClient == NULL )
+        try
         {
-            delete pEv;
-            continue;
+            Client *pClient = rSrv.getClient( pEv->getId() );
+            if( pClient == NULL )
+            {
+                delete pEv;
+                continue;
+            }
+           
+            pClient->processInput();
+            if( pClient->getOutputSize() > 0 )
+            {
+                rSrv.clientWriteReady( pClient->getId() );
+            }
         }
-       
-        pClient->processInput();
-        if( pClient->getOutputSize() > 0 )
+        catch( std::exception &e )
+        {
+           // Probably we're fine, the client just closed between queuing and
+           // working.
+        }
+        catch(...)
         {
-            rSrv.clientWriteReady( pClient->getId() );
         }
         delete pEv;
     }
diff --git a/src/stable/server.h b/src/stable/server.h
index 9fb8282..a9680cf 100644
--- a/src/stable/server.h
+++ b/src/stable/server.h
@@ -23,7 +23,7 @@
 #include "bu/config.h"
 
 #ifndef PROFILE_BU_SERVER
- #define PROFILE_BU_SERVER   1
+// #define PROFILE_BU_SERVER   1
 #endif
 
 #ifdef PROFILE_BU_SERVER
diff --git a/src/stable/sockettcp.h b/src/stable/sockettcp.h
index 3fc14ef..8539b52 100644
--- a/src/stable/sockettcp.h
+++ b/src/stable/sockettcp.h
@@ -48,7 +48,14 @@ namespace Bu
      ...
      ...
      ...
+     // sigset is deprecated
      sigset( SIGPIPE, SIG_IGN ); // do this before you use a Bu::SocketTcp
+
+     // this is the modern Linux alternative
+     struct sigaction saIgnore;
+     memset( &saIgnore, 0, sizeof(struct sigaction) );
+     saIgnore.sa_handler = SIG_IGN;
+     sigaction( SIGPIPE, &saIgnore, NULL );
      @endcode
      * When this is done, Bu::SocketTcp will simply throw a broken pipe
      * exception just like every other error condition, allowing your program
-- 
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