From e234f7c490800ae0a7ae9b5a5b88e8dff1dfafc9 Mon Sep 17 00:00:00 2001
From: vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Tue, 24 Jun 2008 08:36:11 +0000
Subject: [PATCH] [Description]:  Misuse of retransmisson of DHCPDISCOVER in
 Dhcp4 drive, the root cause is that DHCP doesn't retransmit discover message
 when timeout. [Solution]:  Correct the mechanism for discover message.
 [Impaction]:  Dhcp4Dxe. [Reference Info]:  EDK tracker 1150 - Misuse of
 retransmisson of DHCPDISCOVER in Dhcp4 drive.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5366 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Universal/Network/Dhcp4Dxe/Dhcp4Impl.h    |  4 +-
 .../Universal/Network/Dhcp4Dxe/Dhcp4Io.c      | 56 +++++++------------
 2 files changed, 22 insertions(+), 38 deletions(-)

diff --git a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.h b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.h
index d7e41134af..bf401bda0d 100644
--- a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.h
+++ b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Impl.h
@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2006, Intel Corporation
+Copyright (c) 2006 - 2008, Intel Corporation
 All rights reserved. This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -136,8 +136,6 @@ struct _DHCP_SERVICE {
   UINT32                        PacketToLive; // Retransmission timer for our packets
   INTN                          CurRetry;
   INTN                          MaxRetries;
-
-  UINT32                        WaitOffer;    // Time to collect the offers
   UINT32                        LeaseLife;
 };
 
diff --git a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
index 9cead840bd..415ffa8ab7 100644
--- a/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
+++ b/MdeModulePkg/Universal/Network/Dhcp4Dxe/Dhcp4Io.c
@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2006 - 2007, Intel Corporation
+Copyright (c) 2006 - 2008, Intel Corporation
 All rights reserved. This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -272,9 +272,7 @@ DhcpSetTransmitTimer (
 
   DhcpSb->PacketToLive = Times[DhcpSb->CurRetry];
 
-  if (DhcpSb->DhcpState == Dhcp4Selecting) {
-    DhcpSb->WaitOffer = DhcpSb->PacketToLive;
-  }
+  return;
 }
 
 /**
@@ -497,7 +495,6 @@ DhcpCleanLease (
   DhcpSb->PacketToLive  = 0;
   DhcpSb->CurRetry      = 0;
   DhcpSb->MaxRetries    = 0;
-  DhcpSb->WaitOffer     = 0;
   DhcpSb->LeaseLife     = 0;
 }
 
@@ -525,11 +522,6 @@ DhcpChooseOffer (
 
   ASSERT (DhcpSb->LastOffer != NULL);
 
-  //
-  // Stop waiting more offers
-  //
-  DhcpSb->WaitOffer = 0;
-
   //
   // User will cache previous offers if he wants to select
   // from multiple offers. If user provides an invalid packet,
@@ -1501,30 +1493,27 @@ DhcpOnTimerTick (
 
   DhcpSb   = (DHCP_SERVICE *) Context;
   Instance = DhcpSb->ActiveChild;
-
+  
   //
-  // Check the time to wait offer
+  // Check the retransmit timer
   //
-  if ((DhcpSb->WaitOffer > 0) && (--DhcpSb->WaitOffer == 0)) {
+  if ((DhcpSb->PacketToLive > 0) && (--DhcpSb->PacketToLive == 0)) {
+
     //
-    // OK, offer collection finished, select a offer
+    // Select offer at each timeout if any offer received.
     //
-    ASSERT (DhcpSb->DhcpState == Dhcp4Selecting);
+    if (DhcpSb->DhcpState == Dhcp4Selecting && DhcpSb->LastOffer != NULL) {
 
-    if (DhcpSb->LastOffer == NULL) {
-      goto END_SESSION;
-    }
+      Status = DhcpChooseOffer (DhcpSb);
 
-    if (EFI_ERROR (DhcpChooseOffer (DhcpSb))) {
-      goto END_SESSION;
+      if (EFI_ERROR(Status)) {
+        FreePool (DhcpSb->LastOffer);
+        DhcpSb->LastOffer = NULL;
+      } else {
+        goto ON_EXIT;
+      }
     }
-  }
-
-  //
-  // Check the retransmit timer
-  //
-  if ((DhcpSb->PacketToLive > 0) && (--DhcpSb->PacketToLive == 0)) {
-
+    
     if (++DhcpSb->CurRetry < DhcpSb->MaxRetries) {
       //
       // Still has another try
@@ -1532,10 +1521,7 @@ DhcpOnTimerTick (
       DhcpRetransmit (DhcpSb);
       DhcpSetTransmitTimer (DhcpSb);
 
-    } else {
-      if (!DHCP_CONNECTED (DhcpSb->DhcpState)) {
-        goto END_SESSION;
-      }
+    } else if (DHCP_CONNECTED (DhcpSb->DhcpState)) {
 
       //
       // Retransmission failed, if the DHCP request is initiated by
@@ -1562,9 +1548,11 @@ DhcpOnTimerTick (
         DhcpSb->IoStatus = EFI_TIMEOUT;
         DhcpNotifyUser (DhcpSb, DHCP_NOTIFY_RENEWREBIND);
       }
+    } else {
+      goto END_SESSION;
     }
   }
-
+  
   //
   // If an address has been acquired, check whether need to
   // refresh or whether it has expired.
@@ -1628,9 +1616,7 @@ DhcpOnTimerTick (
     }
   }
 
-  //
-  //
-  //
+ON_EXIT:
   if ((Instance != NULL) && (Instance->Token != NULL)) {
     Instance->Timeout--;
     if (Instance->Timeout == 0) {
-- 
2.39.2