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diff --git a/docs/docbook/devdoc/internals.sgml b/docs/docbook/devdoc/internals.sgml deleted file mode 100644 index 982cfd2e10..0000000000 --- a/docs/docbook/devdoc/internals.sgml +++ /dev/null @@ -1,440 +0,0 @@ -<chapter id="internals"> -<chapterinfo> - <author> - <firstname>David</firstname><surname>Chappell</surname> - <affiliation> - <address><email>David.Chappell@mail.trincoll.edu</email></address> - </affiliation> - </author> - <pubdate>8 May 1996</pubdate> -</chapterinfo> - -<title>Samba Internals</title> - -<sect1> -<title>Character Handling</title> -<para> -This section describes character set handling in Samba, as implemented in -Samba 3.0 and above -</para> - -<para> -In the past Samba had very ad-hoc character set handling. Scattered -throughout the code were numerous calls which converted particular -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. -</para> -</sect1> - -<sect1> -<title>The new functions</title> - -<para> -The new system works like this: -</para> - -<orderedlist> -<listitem><para> - all char* strings inside Samba are "unix" strings. These are - multi-byte strings that are in the charset defined by the "unix - charset" option in smb.conf. -</para></listitem> - -<listitem><para> - there is no single fixed character set for unix strings, but any - character set that is used does need the following properties: - </para> - <orderedlist> - - <listitem><para> - must not contain NULLs except for termination - </para></listitem> - - <listitem><para> - must be 7-bit compatible with C strings, so that a constant - string or character in C will be byte-for-byte identical to the - equivalent string in the chosen character set. - </para></listitem> - - <listitem><para> - when you uppercase or lowercase a string it does not become - longer than the original string - </para></listitem> - - <listitem><para> - must be able to correctly hold all characters that your client - will throw at it - </para></listitem> - </orderedlist> - - <para> - For example, UTF-8 is fine, and most multi-byte asian character sets - are fine, but UCS2 could not be used for unix strings as they - contain nulls. - </para> -</listitem> - -<listitem><para> - when you need to put a string into a buffer that will be sent on the - wire, or you need a string in a character set format that is - compatible with the clients character set then you need to use a - pull_ or push_ function. The pull_ functions pull a string from a - wire buffer into a (multi-byte) unix string. The push_ functions - push a string out to a wire buffer. -</para></listitem> - -<listitem><para> - the two main pull_ and push_ functions you need to understand are - pull_string and push_string. These functions take a base pointer - that should point at the start of the SMB packet that the string is - in. The functions will check the flags field in this packet to - automatically determine if the packet is marked as a unicode packet, - and they will choose whether to use unicode for this string based on - that flag. You may also force this decision using the STR_UNICODE or - STR_ASCII flags. For use in smbd/ and libsmb/ there are wrapper - functions clistr_ and srvstr_ that call the pull_/push_ functions - with the appropriate first argument. - </para> - - <para> - You may also call the pull_ascii/pull_ucs2 or push_ascii/push_ucs2 - functions if you know that a particular string is ascii or - unicode. There are also a number of other convenience functions in - charcnv.c that call the pull_/push_ functions with particularly - common arguments, such as pull_ascii_pstring() - </para> -</listitem> - -<listitem><para> - The biggest thing to remember is that internal (unix) strings in Samba - may now contain multi-byte characters. This means you cannot assume - that characters are always 1 byte long. Often this means that you will - have to convert strings to ucs2 and back again in order to do some - (seemingly) simple task. For examples of how to do this see functions - like strchr_m(). I know this is very slow, and we will eventually - speed it up but right now we want this stuff correct not fast. -</para></listitem> - -<listitem><para> - all lp_ functions now return unix strings. The magic "DOS" flag on - parameters is gone. -</para></listitem> - -<listitem><para> - all vfs functions take unix strings. Don't convert when passing to them -</para></listitem> - -</orderedlist> - -</sect1> - -<sect1> -<title>Macros in byteorder.h</title> - -<para> -This section describes the macros defined in byteorder.h. These macros -are used extensively in the Samba code. -</para> - -<sect2> -<title>CVAL(buf,pos)</title> - -<para> -returns the byte at offset pos within buffer buf as an unsigned character. -</para> -</sect2> - -<sect2> -<title>PVAL(buf,pos)</title> -<para>returns the value of CVAL(buf,pos) cast to type unsigned integer.</para> -</sect2> - -<sect2> -<title>SCVAL(buf,pos,val)</title> -<para>sets the byte at offset pos within buffer buf to value val.</para> -</sect2> - -<sect2> -<title>SVAL(buf,pos)</title> -<para> - 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". -</para> -</sect2> - -<sect2> -<title>IVAL(buf,pos)</title> -<para>returns the value of the unsigned 32 bit little-endian integer at offset -pos within buffer buf.</para> -</sect2> - -<sect2> -<title>SVALS(buf,pos)</title> -<para>returns the value of the signed short (16 bit) little-endian integer at -offset pos within buffer buf.</para> -</sect2> - -<sect2> -<title>IVALS(buf,pos)</title> -<para>returns the value of the signed 32 bit little-endian integer at offset pos -within buffer buf.</para> -</sect2> - -<sect2> -<title>SSVAL(buf,pos,val)</title> -<para>sets the unsigned short (16 bit) little-endian integer at offset pos within -buffer buf to value val.</para> -</sect2> - -<sect2> -<title>SIVAL(buf,pos,val)</title> -<para>sets the unsigned 32 bit little-endian integer at offset pos within buffer -buf to the value val.</para> -</sect2> - -<sect2> -<title>SSVALS(buf,pos,val)</title> -<para>sets the short (16 bit) signed little-endian integer at offset pos within -buffer buf to the value val.</para> -</sect2> - -<sect2> -<title>SIVALS(buf,pos,val)</title> -<para>sets the signed 32 bit little-endian integer at offset pos withing buffer -buf to the value val.</para> -</sect2> - -<sect2> -<title>RSVAL(buf,pos)</title> -<para>returns the value of the unsigned short (16 bit) big-endian integer at -offset pos within buffer buf.</para> -</sect2> - -<sect2> -<title>RIVAL(buf,pos)</title> -<para>returns the value of the unsigned 32 bit big-endian integer at offset -pos within buffer buf.</para> -</sect2> - -<sect2> -<title>RSSVAL(buf,pos,val)</title> -<para>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".</para> -</sect2> - -<sect2> -<title>RSIVAL(buf,pos,val)</title> -<para>sets the value of the unsigned 32 bit big-endian integer at offset -pos within buffer buf to value val.</para> -</sect2> - -</sect1> - - -<sect1> -<title>LAN Manager Samba API</title> - -<para> -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 -reliable. -</para> - -<para> -<programlisting> -call_api(int prcnt, int drcnt, int mprcnt, int mdrcnt, - char *param, char *data, char **rparam, char **rdata); -</programlisting> -</para> - -<para> -This function is defined in client.c. It uses an SMB transaction to call a -remote api. -</para> - -<sect2> -<title>Parameters</title> - -<para>The parameters are as follows:</para> - -<orderedlist> -<listitem><para> - prcnt: the number of bytes of parameters begin sent. -</para></listitem> -<listitem><para> - drcnt: the number of bytes of data begin sent. -</para></listitem> -<listitem><para> - mprcnt: the maximum number of bytes of parameters which should be returned -</para></listitem> -<listitem><para> - mdrcnt: the maximum number of bytes of data which should be returned -</para></listitem> -<listitem><para> - param: a pointer to the parameters to be sent. -</para></listitem> -<listitem><para> - data: a pointer to the data to be sent. -</para></listitem> -<listitem><para> - rparam: a pointer to a pointer which will be set to point to the returned - paramters. The caller of call_api() must deallocate this memory. -</para></listitem> -<listitem><para> - rdata: a pointer to a pointer which will be set to point to the returned - data. The caller of call_api() must deallocate this memory. -</para></listitem> -</orderedlist> - -<para> -These are the parameters which you ought to send, in the order of their -appearance in the parameter block: -</para> - -<orderedlist> - -<listitem><para> -An unsigned 16 bit integer API number. You should set this value with -SSVAL(). I do not know where these numbers are described. -</para></listitem> - -<listitem><para> -An ASCIIZ string describing the parameters to the API function as defined -in the LAN Manager documentation. The first parameter, which is the server -name, is ommited. This string is based uppon the API function as described -in the manual, not the data which is actually passed. -</para></listitem> - -<listitem><para> -An ASCIIZ string describing the data structure which ought to be returned. -</para></listitem> - -<listitem><para> -Any parameters which appear in the function call, as defined in the LAN -Manager API documentation, after the "Server" and up to and including the -"uLevel" parameters. -</para></listitem> - -<listitem><para> -An unsigned 16 bit integer which gives the size in bytes of the buffer we -will use to receive the returned array of data structures. Presumably this -should be the same as mdrcnt. This value should be set with SSVAL(). -</para></listitem> - -<listitem><para> -An ASCIIZ string describing substructures which should be returned. If no -substructures apply, this string is of zero length. -</para></listitem> - -</orderedlist> - -<para> -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. -</para> - -</sect2> - -<sect2> -<title>Return value</title> - -<para> -The returned parameters (pointed to by rparam), in their order of appearance -are:</para> - -<orderedlist> - -<listitem><para> -An unsigned 16 bit integer which contains the API function's return code. -This value should be read with SVAL(). -</para></listitem> - -<listitem><para> -An adjustment which tells the amount by which pointers in the returned -data should be adjusted. This value should be read with SVAL(). Basically, -the address of the start of the returned data buffer should have the returned -pointer value added to it and then have this value subtracted from it in -order to obtain the currect offset into the returned data buffer. -</para></listitem> - -<listitem><para> -A count of the number of elements in the array of structures returned. -It is also possible that this may sometimes be the number of bytes returned. -</para></listitem> -</orderedlist> - -<para> -When call_api() returns, rparam points to the returned parameters. The -first if these is the result code. It will be zero if the API call -suceeded. This value by be read with "SVAL(rparam,0)". -</para> - -<para> -The second parameter may be read as "SVAL(rparam,2)". It is a 16 bit offset -which indicates what the base address of the returned data buffer was when -it was built on the server. It should be used to correct pointer before -use. -</para> - -<para> -The returned data buffer contains the array of returned data structures. -Note that all pointers must be adjusted before use. The function -fix_char_ptr() in client.c can be used for this purpose. -</para> - -<para> -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. -</para> - -</sect2> -</sect1> - -<sect1> -<title>Code character table</title> -<para> -Certain data structures are described by means of ASCIIz strings containing -code characters. These are the code characters: -</para> - -<orderedlist> -<listitem><para> -W a type byte little-endian unsigned integer -</para></listitem> -<listitem><para> -N a count of substructures which follow -</para></listitem> -<listitem><para> -D a four byte little-endian unsigned integer -</para></listitem> -<listitem><para> -B a byte (with optional count expressed as trailing ASCII digits) -</para></listitem> -<listitem><para> -z a four byte offset to a NULL terminated string -</para></listitem> -<listitem><para> -l a four byte offset to non-string user data -</para></listitem> -<listitem><para> -b an offset to data (with count expressed as trailing ASCII digits) -</para></listitem> -<listitem><para> -r pointer to returned data buffer??? -</para></listitem> -<listitem><para> -L length in bytes of returned data buffer??? -</para></listitem> -<listitem><para> -h number of bytes of information available??? -</para></listitem> -</orderedlist> - -</sect1> -</chapter> |