From 8bd32f489700a31c14e50a914a38f421fe3cfaea Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Thu, 28 Jul 2011 20:22:45 -0700
Subject: [PATCH 1/2] First part of bugfix for bug #8335 - file copy aborts with smb2_validate_message_id: bad message_id

Set default max credits to 8192 now this has been documented in the
SMB2 spec.
---
 docs-xml/smbdotconf/protocol/smb2maxcredits.xml |    2 +-
 source3/include/local.h                         |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs-xml/smbdotconf/protocol/smb2maxcredits.xml b/docs-xml/smbdotconf/protocol/smb2maxcredits.xml
index 69d04f7..310b898 100644
--- a/docs-xml/smbdotconf/protocol/smb2maxcredits.xml
+++ b/docs-xml/smbdotconf/protocol/smb2maxcredits.xml
@@ -8,7 +8,7 @@
 that Samba tells the client it will allow. This is similar to the <smbconfoption name="max mux"/>
 parameter for SMB1. You should never need to set this parameter.
 </para>
-<para>The default is 128 credits, which is the same as a Windows SMB2 server.</para>
+<para>The default is 8192 credits, which is the same as a Windows 2008R2 SMB2 server.</para>
 </description>
 
 <value type="default">128</value>
diff --git a/source3/include/local.h b/source3/include/local.h
index 594f700..d71a72c 100644
--- a/source3/include/local.h
+++ b/source3/include/local.h
@@ -235,7 +235,7 @@
 #define DEFAULT_SMB2_MAX_READ (1024*1024)
 #define DEFAULT_SMB2_MAX_WRITE (1024*1024)
 #define DEFAULT_SMB2_MAX_TRANSACT (1024*1024)
-#define DEFAULT_SMB2_MAX_CREDITS 128
+#define DEFAULT_SMB2_MAX_CREDITS 8192
 #define DEFAULT_SMB2_MAX_CREDIT_BITMAP_FACTOR 2
 
 #endif
-- 
1.7.1


From 0159b0e3d3b51d468e9494c33c123636e0ad718d Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Thu, 28 Jul 2011 20:23:30 -0700
Subject: [PATCH 2/2] Secod part of bugfix for bug #8335 - file copy aborts with smb2_validate_message_id: bad message_id

Modify the credit granting algorithm to closer to what I believe
Windows does.

Split up max_credits into 1/16ths, and then scale
the requested credits by how many 16ths have been
currently granted. Less than 1/16th == grant all
requested (100%), scale down as more have been
granted. Never ask for less than 1 if the client
asked for at least 1.
---
 source3/smbd/smb2_server.c |   27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/source3/smbd/smb2_server.c b/source3/smbd/smb2_server.c
index 65454ae..48fb20f 100644
--- a/source3/smbd/smb2_server.c
+++ b/source3/smbd/smb2_server.c
@@ -455,9 +455,30 @@ static void smb2_set_operation_credit(struct smbd_server_connection *sconn,
 
 	SMB_ASSERT(sconn->smb2.max_credits >= sconn->smb2.credits_granted);
 
-	/* Remember what we gave out. */
-	credits_granted = MIN(credits_requested, (sconn->smb2.max_credits -
-		sconn->smb2.credits_granted));
+	if (credits_requested) {
+		uint16_t modified_credits_requested;
+		uint32_t multiplier;
+
+		/*
+		 * Split up max_credits into 1/16ths, and then scale
+		 * the requested credits by how many 16ths have been
+		 * currently granted. Less than 1/16th == grant all
+		 * requested (100%), scale down as more have been
+		 * granted. Never ask for less than 1 as the client
+		 * asked for at least 1. JRA.
+		 */
+
+		multiplier = 16 - (((sconn->smb2.credits_granted * 16) / sconn->smb2.max_credits) % 16);
+
+		modified_credits_requested = (multiplier * credits_requested) / 16;
+		if (modified_credits_requested == 0) {
+			modified_credits_requested = 1;
+		}
+
+		/* Remember what we gave out. */
+		credits_granted = MIN(modified_credits_requested,
+					(sconn->smb2.max_credits - sconn->smb2.credits_granted));
+	}
 
 	if (credits_granted == 0 && sconn->smb2.credits_granted == 0) {
 		/* First negprot packet, or ensure the client credits can
-- 
1.7.1