SAMBA Developers Guide

Macros in byteorder.h

dbgtext()
dbghdr()
format_debug_text()

4. Coding Suggestions

5. Samba Internals

Character Handling

The new functions

CVAL(buf,pos)
PVAL(buf,pos)
SCVAL(buf,pos,val)
SVAL(buf,pos)
IVAL(buf,pos)
SVALS(buf,pos)
IVALS(buf,pos)
SSVAL(buf,pos,val)
SIVAL(buf,pos,val)
SSVALS(buf,pos,val)
SIVALS(buf,pos,val)
RSVAL(buf,pos)
RIVAL(buf,pos)
RSSVAL(buf,pos,val)
RSIVAL(buf,pos,val)

LAN Manager Samba API

Parameters
Return value

Code character table

6. The smb.conf file

Handling of Whitespace
Handling of Line Continuation
Line Continuation Quirks

About params.c

7. NetBIOS in a Unix World

Introduction
Usernames
File Ownership
Passwords
Locking
Deny Modes
Trapdoor UIDs
Port numbers
Protocol Complexity

8. Tracing samba system calls

9. NT Domain RPC's

Sources
Credits

Notes
Enumerations
Structures

MSRPC Pipes
Header
Tail
RPC Bind / Bind Ack
NTLSA Transact Named Pipe
LSA Open Policy
LSA Query Info Policy
LSA Enumerate Trusted Domains
LSA Open Secret
LSA Close
LSA Lookup SIDS
LSA Lookup Names

LSA Request Challenge
LSA Authenticate 2
LSA Server Password Set
LSA SAM Logon
LSA SAM Logoff

Query for PDC
SAM Logon

Net Share Enum
Net Server Get Info

Definitions
Protocol
Comments

1. Definition of NetBIOS Protocol and Name Resolution Modes

Well-known SIDs
Well-known RIDS

10. Samba Printing Internals

Abstract
+

Table of Contents

NETBIOS
BROADCAST NetBIOS
NBNS NetBIOS

2. Samba Architecture

Introduction
Multithreading and Samba
Threading smbd
Threading nmbd
nbmd Design

3. The samba DEBUG system

Macros in byteorder.h

dbgtext()
dbghdr()
format_debug_text()

4. Coding Suggestions

5. Samba Internals

Character Handling

The new functions

CVAL(buf,pos)
PVAL(buf,pos)
SCVAL(buf,pos,val)
SVAL(buf,pos)
IVAL(buf,pos)
SVALS(buf,pos)
IVALS(buf,pos)
SSVAL(buf,pos,val)
SIVAL(buf,pos,val)
SSVALS(buf,pos,val)
SIVALS(buf,pos,val)
RSVAL(buf,pos)
RIVAL(buf,pos)
RSSVAL(buf,pos,val)
RSIVAL(buf,pos,val)

LAN Manager Samba API

Parameters
Return value

Code character table

6. The smb.conf file

Handling of Whitespace
Handling of Line Continuation
Line Continuation Quirks

9. Finding useful information on windows

About params.c

7. NetBIOS in a Unix World

Introduction
Usernames
File Ownership
Passwords
Locking
Deny Modes
Trapdoor UIDs
Port numbers
Protocol Complexity

8. Tracing samba system calls

Netlogon debugging output

10. NT Domain RPC's

Sources
Credits

Notes
Enumerations
Structures

MSRPC Pipes
Header
Tail
RPC Bind / Bind Ack
NTLSA Transact Named Pipe
LSA Open Policy
LSA Query Info Policy
LSA Enumerate Trusted Domains
LSA Open Secret
LSA Close
LSA Lookup SIDS
LSA Lookup Names

LSA Request Challenge
LSA Authenticate 2
LSA Server Password Set
LSA SAM Logon
LSA SAM Logoff

Query for PDC
SAM Logon

Net Share Enum
Net Server Get Info

Definitions
Protocol
Comments

Security in the 'new SAM'

Well-known SIDs
Well-known RIDS

11. Samba Printing Internals

Abstract
Printing Interface to Various Back ends -
+
Print Queue TDB's -
+
ChangeID and Client Caching of Printer Information -
+
Windows NT/2K Printer Change Notify -

11. Samba WINS Internals

WINS Failover

12. The Upcoming SAM System

Standalone from UNIX

Handles and Races in the new SAM

Layers

Application
SAM Interface
SAM Modules

SAM Modules

Special Module: sam_passdb
sam_ads

Memory Management

Testing

13. LanMan and NT Password Encryption

Introduction
How does it work?
The smbpasswd file

14. Modules

Advantages

Loading modules

Static modules
Shared modules

Writing modules

Static/Shared selection in configure.in

15. RPC Pluggable Modules

About
General Overview

16. Notes to packagers

Versioning
Modules

Chapter 1. Definition of NetBIOS Protocol and Name Resolution Modes

Luke Leighton

12 June 1997

Table of Contents

NETBIOS
BROADCAST NetBIOS
NBNS NetBIOS

NETBIOS

12. Samba WINS Internals

WINS Failover

13. The Upcoming SAM System

Security in the 'new SAM'

Standalone from UNIX

Handles and Races in the new SAM

Layers

Application
SAM Interface
SAM Modules

SAM Modules

Special Module: sam_passdb
sam_ads

Memory Management

Testing

14. LanMan and NT Password Encryption

Introduction
How does it work?
The smbpasswd file

15. Modules

Advantages

Loading modules

Static modules
Shared modules

Writing modules

Static/Shared selection in configure.in

16. RPC Pluggable Modules

About
General Overview

17. VFS Modules

The Samba (Posix) VFS layer

The general interface
Possible VFS operation layers

The Interaction between the Samba VFS subsystem and the modules

Initialization and registration
How the Modules handle per connection data

Upgrading to the New VFS Interface

Upgrading from 2.2.* and 3.0aplha modules

Some Notes

Implement TRANSPARENT functions
Implement OPAQUE functions

18. Notes to packagers

Versioning
Modules

19. Contributing code

Chapter 1. Definition of NetBIOS Protocol and Name Resolution Modes

Luke Leighton

12 June 1997

Table of Contents

NETBIOS
BROADCAST NetBIOS
NBNS NetBIOS

NETBIOS

NetBIOS runs over the following tranports: TCP/IP; NetBEUI and IPX/SPX. Samba only uses NetBIOS over TCP/IP. For details on the TCP/IP NetBIOS Session Service NetBIOS Datagram Service, and NetBIOS Names, see @@ -61,7 +78,7 @@ NetBIOS names are either UNIQUE or GROUP. Only one application can claim a UNIQUE NetBIOS name on a network.

There are two kinds of NetBIOS Name resolution: Broadcast and Point-to-Point. -

BROADCAST NetBIOS

Clients can claim names, and therefore offer services on successfully claimed names, on their broadcast-isolated subnet. One way to get NetBIOS services (such as browsing: see ftp.microsoft.com/drg/developr/CIFS/browdiff.txt; and @@ -73,7 +90,7 @@ find that some of your hosts spend 95 percent of their time dealing with broadcast traffic. [If you have IPX/SPX on your LAN or WAN, you will find that this is already happening: a packet analyzer will show, roughly every twelve minutes, great swathes of broadcast traffic!]. -

NBNS NetBIOS

rfc1001.txt describes, amongst other things, the implementation and use of, a 'NetBIOS Name Service'. NT/AS offers 'Windows Internet Name Service' which is fully rfc1001/2 compliant, but has had to take specific action @@ -114,7 +131,7 @@ WINS Clients therefore claim names from the WINS server. If the WINS server allows them to register a name, the client's NetBIOS session service can then offer services on this name. Other WINS clients will then contact the WINS server to resolve a NetBIOS name. -

Chapter 2. Samba Architecture

Dan Shearer

November 1997

Table of Contents

Introduction
Multithreading and Samba
Threading smbd
Threading nmbd
nbmd Design

Introduction

Chapter 2. Samba Architecture

Dan Shearer

November 1997

Table of Contents

Introduction
Multithreading and Samba
Threading smbd
Threading nmbd
nbmd Design

Introduction

This document gives a general overview of how Samba works internally. The Samba Team has tried to come up with a model which is the best possible compromise between elegance, portability, security @@ -125,7 +142,7 @@ It also tries to answer some of the frequently asked questions such as:

Is Samba secure when running on Unix? The xyz platform? What about the root priveliges issue? -
Pros and cons of multithreading in various parts of Samba
Why not have a separate process for name resolution, WINS, and browsing?

Multithreading and Samba

Pros and cons of multithreading in various parts of Samba

Why not have a separate process for name resolution, WINS, and browsing?

Multithreading and Samba

People sometimes tout threads as a uniformly good thing. They are very nice in their place but are quite inappropriate for smbd. nmbd is another matter, and multi-threading it would be very nice. @@ -142,7 +159,7 @@ smbd multi-threaded. Multi-threading would actually make Samba much slower, less scalable, less portable and much less robust. The fact that we use a separate process for each connection is one of Samba's biggest advantages. -

Threading smbd

A few problems that would arise from a threaded smbd are:

It's not only to create threads instead of processes, but you @@ -167,7 +184,7 @@ A few problems that would arise from a threaded smbd are:
we couldn't use the system locking calls as the locking context of fcntl() is a process, not a thread. -

Threading nmbd

This would be ideal, but gets sunk by portability requirements.

Andrew tried to write a test threads library for nmbd that used only @@ -194,7 +211,7 @@ packet that arrives. Having a pool of processes is possible but is nasty to program cleanly due to the enormous amount of shared data (in complex structures) between the processes. We can't rely on each platform having a shared memory system. -

nbmd Design

Originally Andrew used recursion to simulate a multi-threaded environment, which use the stack enormously and made for really confusing debugging sessions. Luke Leighton rewrote it to use a @@ -215,7 +232,7 @@ keeps the idea of a distinct packet. See "struct packet_struct" in nameserv.h. It has all the detail but none of the on-the-wire mess. This makes it ideal for using in disk or memory-based databases for browsing and WINS support. -

Chapter 3. The samba DEBUG system

Chris Hertel

July 1998

Table of Contents

dbgtext()
dbghdr()
format_debug_text()

New Output Syntax

Chapter 3. The samba DEBUG system

Chris Hertel

July 1998

Table of Contents

dbgtext()
dbghdr()
format_debug_text()

New Output Syntax

The syntax of a debugging log file is represented as:

   >debugfile< :== { >debugmsg< }
@@ -268,7 +285,7 @@ by a newline.
 Note that in the above example the function names are not listed on
 the header line. That's because the example above was generated on an
 SGI Indy, and the SGI compiler doesn't support the __FUNCTION__ macro.
-

The DEBUG() Macro

Use of the DEBUG() macro is unchanged. DEBUG() takes two parameters. The first is the message level, the second is the body of a function call to the Debug1() function. @@ -319,7 +336,7 @@ would look like this: [1998/07/30 16:00:51, 0] file.c:function(261) .

Which isn't much use. The format buffer kludge fixes this problem. -

The DEBUGADD() Macro

In addition to the kludgey solution to the broken line problem described above, there is a clean solution. The DEBUGADD() macro never generates a header. It will append new text to the current debug @@ -333,7 +350,7 @@ DEBUGADD() macro is the same as that of the DEBUG() macro. This is the first line. This is the second line. This is the third line. -

The DEBUGLVL() Macro

One of the problems with the DEBUG() macro was that DEBUG() lines tended to get a bit long. Consider this example from nmbd_sendannounce.c: @@ -368,7 +385,7 @@ within the DEBUGLVL() block.

Processing that is only relevant to debug output can be contained within the DEBUGLVL() block. -

New Functions

dbgtext()

New Functions

dbgtext()

This function prints debug message text to the debug file (and possibly to syslog) via the format buffer. The function uses a variable argument list just like printf() or Debug1(). The @@ -377,7 +394,7 @@ and then passed to format_debug_text(). If you use DEBUGLVL() you will probably print the body of the message using dbgtext(). -

dbghdr()

This is the function that writes a debug message header. Headers are not processed via the format buffer. Also note that if the format buffer is not empty, a call to dbghdr() will not @@ -385,7 +402,7 @@ produce any output. See the comments in dbghdr() for more info.

It is not likely that this function will be called directly. It is used by DEBUG() and DEBUGADD(). -

format_debug_text()

This is a static function in debug.c. It stores the output text for the body of the message in a buffer until it encounters a newline. When the newline character is found, the buffer is @@ -394,7 +411,7 @@ buffer is reset. This allows us to add the indentation at the beginning of each line of the message body, and also ensures that the output is written a line at a time (which cleans up syslog output). -

Chapter 4. Coding Suggestions

Steve French

Simo Sorce

Andrew Bartlett

Tim Potter

Martin Pool

Chapter 4. Coding Suggestions

Steve French

Simo Sorce

Andrew Bartlett

Tim Potter

Martin Pool

So you want to add code to Samba ...

One of the daunting tasks facing a programmer attempting to write code for @@ -405,8 +422,8 @@ document will attempt to document a few of the more important coding practices used at this time on the Samba project. The coding practices are expected to change slightly over time, and even to grow as more is learned about obscure portability considerations. Two existing documents -samba/source/internals.doc and -samba/source/architecture.doc provide +samba/source/internals.doc and +samba/source/architecture.doc provide additional information.

The loosely related question of coding style is very personal and this @@ -536,7 +553,7 @@ The suggestions above are simply that, suggestions, but the information may help in reducing the routine rework done on new code. The preceeding list is expected to change routinely as new support routines and macros are added. -

Chapter 5. Samba Internals

David Chappell

<David.Chappell@mail.trincoll.edu>

8 May 1996

Character Handling

Chapter 5. Samba Internals

David Chappell

<David.Chappell@mail.trincoll.edu>

8 May 1996

Character Handling

This section describes character set handling in Samba, as implemented in Samba 3.0 and above

@@ -546,7 +563,7 @@ strings to/from DOS codepages. The problem is that there was no way of telling if a particular char* is in dos codepage or unix codepage. This led to a nightmare of code that tried to cope with particular cases without handlingt the general case. -

The new functions

The new system works like this:

all char* strings inside Samba are "unix" strings. These are @@ -608,28 +625,28 @@ The new system works like this: parameters is gone.
all vfs functions take unix strings. Don't convert when passing to them -

Macros in byteorder.h

This section describes the macros defined in byteorder.h. These macros are used extensively in the Samba code. -

CVAL(buf,pos)

returns the byte at offset pos within buffer buf as an unsigned character. -

PVAL(buf,pos)

returns the value of CVAL(buf,pos) cast to type unsigned integer.

SCVAL(buf,pos,val)

sets the byte at offset pos within buffer buf to value val.

SVAL(buf,pos)

PVAL(buf,pos)

returns the value of CVAL(buf,pos) cast to type unsigned integer.

SCVAL(buf,pos,val)

sets the byte at offset pos within buffer buf to value val.

SVAL(buf,pos)

returns the value of the unsigned short (16 bit) little-endian integer at offset pos within buffer buf. An integer of this type is sometimes refered to as "USHORT". -

IVAL(buf,pos)

returns the value of the unsigned 32 bit little-endian integer at offset -pos within buffer buf.

SVALS(buf,pos)

returns the value of the signed short (16 bit) little-endian integer at -offset pos within buffer buf.

IVALS(buf,pos)

returns the value of the signed 32 bit little-endian integer at offset pos -within buffer buf.

SSVAL(buf,pos,val)

sets the unsigned short (16 bit) little-endian integer at offset pos within -buffer buf to value val.

SIVAL(buf,pos,val)

sets the unsigned 32 bit little-endian integer at offset pos within buffer -buf to the value val.

SSVALS(buf,pos,val)

sets the short (16 bit) signed little-endian integer at offset pos within -buffer buf to the value val.

SIVALS(buf,pos,val)

sets the signed 32 bit little-endian integer at offset pos withing buffer -buf to the value val.

RSVAL(buf,pos)

returns the value of the unsigned short (16 bit) big-endian integer at -offset pos within buffer buf.

RIVAL(buf,pos)

returns the value of the unsigned 32 bit big-endian integer at offset -pos within buffer buf.

RSSVAL(buf,pos,val)

sets the value of the unsigned short (16 bit) big-endian integer at +

IVAL(buf,pos)

returns the value of the unsigned 32 bit little-endian integer at offset +pos within buffer buf.

SVALS(buf,pos)

returns the value of the signed short (16 bit) little-endian integer at +offset pos within buffer buf.

IVALS(buf,pos)

returns the value of the signed 32 bit little-endian integer at offset pos +within buffer buf.

SSVAL(buf,pos,val)

sets the unsigned short (16 bit) little-endian integer at offset pos within +buffer buf to value val.

SIVAL(buf,pos,val)

sets the unsigned 32 bit little-endian integer at offset pos within buffer +buf to the value val.

SSVALS(buf,pos,val)

sets the short (16 bit) signed little-endian integer at offset pos within +buffer buf to the value val.

SIVALS(buf,pos,val)

sets the signed 32 bit little-endian integer at offset pos withing buffer +buf to the value val.

RSVAL(buf,pos)

returns the value of the unsigned short (16 bit) big-endian integer at +offset pos within buffer buf.

RIVAL(buf,pos)

returns the value of the unsigned 32 bit big-endian integer at offset +pos within buffer buf.

RSSVAL(buf,pos,val)

sets the value of the unsigned short (16 bit) big-endian integer at offset pos within buffer buf to value val. -refered to as "USHORT".

RSIVAL(buf,pos,val)

sets the value of the unsigned 32 bit big-endian integer at offset -pos within buffer buf to value val.

LAN Manager Samba API

+refered to as "USHORT".

RSIVAL(buf,pos,val)

sets the value of the unsigned 32 bit big-endian integer at offset +pos within buffer buf to value val.

LAN Manager Samba API

This section describes the functions need to make a LAN Manager RPC call. This information had been obtained by examining the Samba code and the LAN Manager 2.0 API documentation. It should not be considered entirely @@ -642,7 +659,7 @@ call_api(int prcnt, int drcnt, int mprcnt, int mdrcnt,

This function is defined in client.c. It uses an SMB transaction to call a remote api. -

Parameters

The parameters are as follows:

+
Parameters
The parameters are as follows:
1. prcnt: the number of bytes of parameters begin sent.
2. drcnt: the number of bytes of data begin sent. @@ -687,7 +704,7 @@ substructures apply, this string is of zero length.
The code in client.c always calls call_api() with no data. It is unclear when a non-zero length data buffer would be sent. -
Return value
+
Return value
The returned parameters (pointed to by rparam), in their order of appearance are:
1. An unsigned 16 bit integer which contains the API function's return code. @@ -718,7 +735,7 @@ fix_char_ptr() in client.c can be used for this purpose. The third parameter (which may be read as "SVAL(rparam,4)") has something to do with indicating the amount of data returned or possibly the amount of data which can be returned if enough buffer space is allowed. -
Code character table
+

Code character table

Certain data structures are described by means of ASCIIz strings containing code characters. These are the code characters:

@@ -741,7 +758,7 @@ r pointer to returned data buffer??? L length in bytes of returned data buffer???
h number of bytes of information available??? -

Chapter 6. The smb.conf file

Chris Hertel

November 1997

Table of Contents

Handling of Whitespace
Handling of Line Continuation
Line Continuation Quirks

About params.c

Lexical Analysis

Chapter 6. The smb.conf file

Chris Hertel

November 1997

Table of Contents

Handling of Whitespace
Handling of Line Continuation
Line Continuation Quirks

About params.c

Lexical Analysis

Basically, the file is processed on a line by line basis. There are four types of lines that are recognized by the lexical analyzer (params.c): @@ -768,7 +785,7 @@ ignores them. The latter two line types are scanned for These are the only tokens passed to the parameter loader (loadparm.c). Parameter names and values are divided from one another by an equal sign: '='. -

Handling of Whitespace

Whitespace is defined as all characters recognized by the isspace() function (see ctype(3C)) except for the newline character ('\n') The newline is excluded because it identifies the end of the line. @@ -783,7 +800,7 @@ the exception of carriage return characters ('\r'), all of which are removed.

Leading and trailing whitespace is removed from names and values. -

Handling of Line Continuation

Long section header and parameter lines may be extended across multiple lines by use of the backslash character ('\\'). Line continuation is ignored for blank and comment lines. @@ -806,7 +823,7 @@ line, plus the four preceeding the word 'with' in the second line. Line continuation characters are ignored on blank lines and at the end of comments. They are *only* recognized within section and parameter lines. -

Line Continuation Quirks

Note the following example:

Line Continuation Quirks

Note the following example:

 	param name = parameter value string \
     \
     with line continuation.
@@ -830,7 +847,7 @@ terminating character, and the rest of the line is ignored.  The lines

are read as

 	[section name]
     param name = value
-

Syntax

The syntax of the smb.conf file is as follows:

Syntax

The syntax of the smb.conf file is as follows:

   <file>            :==  { <section> } EOF
   <section>         :==  <section header> { <parameter line> }
   <section header>  :==  '[' NAME ']'
@@ -849,12 +866,12 @@ terminating character, and the rest of the line is ignored.  The lines
 	A parameter line is divided into a NAME and a VALUE.  The *first*
 	equal sign on the line separates the NAME from the VALUE.  The
 	VALUE is terminated by a newline character (NL = '\n').
-

About params.c

The parsing of the config file is a bit unusual if you are used to lex, yacc, bison, etc. Both lexical analysis (scanning) and parsing are performed by params.c. Values are loaded via callbacks to loadparm.c. -

Chapter 7. NetBIOS in a Unix World

Andrew Tridgell

April 1995

Table of Contents

Introduction
Usernames
File Ownership
Passwords
Locking
Deny Modes
Trapdoor UIDs
Port numbers
Protocol Complexity

Introduction

Chapter 7. NetBIOS in a Unix World

Andrew Tridgell

April 1995

Table of Contents

Introduction
Usernames
File Ownership
Passwords
Locking
Deny Modes
Trapdoor UIDs
Port numbers
Protocol Complexity

Introduction

This is a short document that describes some of the issues that confront a SMB implementation on unix, and how Samba copes with them. They may help people who are looking at unix<->PC @@ -862,7 +879,7 @@ interoperability.

It was written to help out a person who was writing a paper on unix to PC connectivity. -

Usernames

The SMB protocol has only a loose username concept. Early SMB protocols (such as CORE and COREPLUS) have no username concept at all. Even in later protocols clients often attempt operations @@ -899,7 +916,7 @@ in the vast majority of cases. The methods include username maps, the service%user syntax, the saving of session setup usernames for later validation and the derivation of the username from the service name (either directly or via the user= option). -

File Ownership

The commonly used SMB protocols have no way of saying "you can't do that because you don't own the file". They have, in fact, no concept of file ownership at all. @@ -917,7 +934,7 @@ file time comparisons right. There are several possible solutions to this problem, including username mapping, and forcing a specific username for particular shares. -

Passwords

Many SMB clients uppercase passwords before sending them. I have no idea why they do this. Interestingly WfWg uppercases the password only if the server is running a protocol greater than COREPLUS, so @@ -939,7 +956,7 @@ This means that it is *VERY* important to ensure that the Samba smbpasswd file containing these password hashes is only readable by the root user. See the documentation ENCRYPTION.txt for more details. -

Locking

Since samba 2.2, samba supports other types of locking as well. This section is outdated.

@@ -970,7 +987,7 @@ asking the server to notify it if anyone else tries to do something on the same file, at which time the client will say if it is willing to give up its lock. Unix has no simple way of implementing opportunistic locking, and currently Samba has no support for it. -

Deny Modes

When a SMB client opens a file it asks for a particular "deny mode" to be placed on the file. These modes (DENY_NONE, DENY_READ, DENY_WRITE, DENY_ALL, DENY_FCB and DENY_DOS) specify what actions should be @@ -984,7 +1001,7 @@ directory or a shared memory implementation. The lock file method is clumsy and consumes processing and file resources, the shared memory implementation is vastly prefered and is turned on by default for those systems that support it. -

Trapdoor UIDs

A SMB session can run with several uids on the one socket. This happens when a user connects to two shares with different usernames. To cope with this the unix server needs to switch uids @@ -994,7 +1011,7 @@ a single uid.

Note that you can also get the "trapdoor uid" message for other reasons. Please see the FAQ for details. -

Port numbers

There is a convention that clients on sockets use high "unprivilaged" port numbers (>1000) and connect to servers on low "privilaged" port numbers. This is enforced in Unix as non-root users can't open a @@ -1017,7 +1034,7 @@ to any of these OSes unless they are running as root. The answer comes back, but it goes to port 137 which the unix user can't listen on. Interestingly WinNT3.1 got this right - it sends node status responses back to the source port in the request. -

Protocol Complexity

There are many "protocol levels" in the SMB protocol. It seems that each time new functionality was added to a Microsoft operating system, they added the equivalent functions in a new protocol level of the SMB @@ -1055,7 +1072,7 @@ published new specifications. These are far superior to the old X/Open documents but there are still undocumented calls and features. This specification is actively being worked on by a CIFS developers mailing list hosted by Microsft. -

Chapter 8. Tracing samba system calls

Andrew Tridgell

Samba Team

Chapter 8. Tracing samba system calls

Andrew Tridgell

Samba Team

This file describes how to do a system call trace on Samba to work out what its doing wrong. This is not for the faint of heart, but if you are reading this then you are probably desperate. @@ -1081,8 +1098,8 @@ strace as strace is the only portable system tracer (its available for free for many unix types) and its also got some of the nicest features.

-Next, try using strace on some simple commands. For example, strace -ls or strace echo hello. +Next, try using strace on some simple commands. For example, strace +ls or strace echo hello.

You'll notice that it produces a LOT of output. It is showing you the arguments to every system call that the program makes and the @@ -1091,7 +1108,7 @@ get lots of output. You'll also find that it produces a lot of "preamble" stuff showing the loading of shared libraries etc. Ignore this (unless its going wrong!)

-For example, the only line that really matters in the strace echo +For example, the only line that really matters in the strace echo hello output is:

 write(1, "hello\n", 6)                  = 6
@@ -1100,10 +1117,10 @@ Ok, now you're familiar with strace. To use it on Samba you need to
 strace the running smbd daemon. The way I tend ot use it is to first
 login from my Windows PC to the Samba server, then use smbstatus to
 find which process ID that client is attached to, then as root I do
-strace -p PID to attach to that process. I normally redirect the
+strace -p PID to attach to that process. I normally redirect the
 stderr output from this command to a file for later perusal. For
 example, if I'm using a csh style shell:
-
strace -f -p 3872 >& strace.out
or with a sh style shell:
strace -f -p 3872 > strace.out 2>&1

+
strace -f -p 3872 >& strace.out
or with a sh style shell:
strace -f -p 3872 > strace.out 2>&1

 Note the "-f" option. This is only available on some systems, and
 allows you to trace not just the current process, but any children it
 forks. This is great for finding printing problems caused by the
@@ -1122,16 +1139,16 @@ numbers and "follow" what happens to an open file until it is closed.
 

 Beyond this you will have to use your initiative. To give you an idea
 of what you are looking for here is a piece of strace output that
-shows that /dev/null is not world writeable, which
+shows that /dev/null is not world writeable, which
 causes printing to fail with Samba:
 
 [pid 28268] open("/dev/null", O_RDWR)   = -1 EACCES (Permission denied)
 [pid 28268] open("/dev/null", O_WRONLY) = -1 EACCES (Permission denied)
 

-The process is trying to first open /dev/null read-write 
-then read-only. Both fail. This means /dev/null has 
+The process is trying to first open /dev/null read-write 
+then read-only. Both fail. This means /dev/null has 
 incorrect permissions.
-

Chapter 9. NT Domain RPC's

01 November 97(version 0.0.24)

Table of Contents

Sources
Credits

Notes
Enumerations
Structures

MSRPC Pipes
Header
Tail
RPC Bind / Bind Ack
NTLSA Transact Named Pipe
LSA Open Policy
LSA Query Info Policy
LSA Enumerate Trusted Domains
LSA Open Secret
LSA Close
LSA Lookup SIDS
LSA Lookup Names

LSA Request Challenge
LSA Authenticate 2
LSA Server Password Set
LSA SAM Logon
LSA SAM Logoff

Query for PDC
SAM Logon

Net Share Enum
Net Server Get Info

Definitions
Protocol
Comments

Well-known SIDs
Well-known RIDS

Introduction

Chapter 9. Finding useful information on windows

Jelmer R. Vernooij

The Samba Team
<jelmer@samba.org>

Andrew Tridgell

Samba Team
<tridge@samba.org>

Table of Contents

Netlogon debugging output

Netlogon debugging output

stop netlogon service on PDC
rename original netlogon.dll to netlogon.dll.original
copy checked version of netlogon.dll to system32 directory
set HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\DBFlag to 0x20000004
start netlogon service on PDC

Chapter 10. NT Domain RPC's

Luke Leighton

<lkcl@switchboard.net>

Paul Ashton

<paul@argo.demon.co.uk>

Duncan Stansfield

<duncans@sco.com>

01 November 97(version 0.0.24)

Table of Contents

Sources
Credits

Notes
Enumerations
Structures

MSRPC Pipes
Header
Tail
RPC Bind / Bind Ack
NTLSA Transact Named Pipe
LSA Open Policy
LSA Query Info Policy
LSA Enumerate Trusted Domains
LSA Open Secret
LSA Close
LSA Lookup SIDS
LSA Lookup Names

LSA Request Challenge
LSA Authenticate 2
LSA Server Password Set
LSA SAM Logon
LSA SAM Logoff

Query for PDC
SAM Logon

Net Share Enum
Net Server Get Info

Definitions
Protocol
Comments