+
+
THIS IS INCOMPLETE! I'M ONLY COMMITING IT IN ORDER TO SOLICIT COMMENTS
FROM A FEW PEOPLE. DON'T TAKE THIS AS THE FINAL VERSION YET.
- it makes code much less likely to be recursion-safe
- it leads to subtle side effects when the same code is called from
multiple places
+ - doesn't play well with shared libraries or plugins
Static data is particularly evil in library code (such as our internal
smb and rpc libraries). If you can get rid of all static data in
"text"). So you can have constant tables of protocol data.
-Memory Contexts
----------------
+How to use talloc
+-----------------
-We introduced the talloc() system for memory contexts during the 2.2
-development cycle and it has been a great success. It has greatly
-simplified a lot of our code, particularly with regard to error
-handling.
-
-In Samba4 we use talloc even more extensively to give us much finer
-grained memory management. The really important thing to remember
-about talloc in Samba4 is:
-
- "don't just use the first talloc context that comes to hand - use
- the RIGHT talloc context"
-
-Just using the first talloc context that comes to hand is probably the
-most common systematic bug I have seen so far from programmers that
-have worked on the Samba4 code base. The reason this is vital is that
-different talloc contexts have vastly different lifetimes, so if you
-use a talloc context that has a long lifetime (such as one associated
-with a tree connection) for data that is very short lived (such as
-parsing an individual packet) then you have just introduced a huge
-memory leak.
-
-In fact, it is quite common that the correct thing to do is to create
-a new talloc context for some little function and then destroy it when
-you are done. That will give you a memory context that has exactly the
-right lifetime.
-
-You should also go and look at a new talloc function in Samba4 called
-talloc_steal(). By using talloc_steal() you can move a lump of memory
-from one memory context to another without copying the data. This
-should be used when a backend function (such as a packet parser)
-produces a result as a lump of talloc memory and you need to keep it
-around for a longer lifetime than the talloc context it is in. You
-just "steal" the memory from the short-lived context, putting it into
-your long lived context.
+Please see the separate document, source/lib/talloc/talloc_guide.txt
+You _must_ read this if you want to program in Samba4.
Interface Structures
In Samba3 many of the core wire structures in the SMB protocol were
never explicitly defined in Samba. Instead, our parse and generation
functions just worked directly with wire buffers. The biggest problem
-with this is that is tied our parse code with out "business logic"
+with this is that is tied our parse code with our "business logic"
much too closely, which meant the code got extremely confusing to
read.
are extremely important differences in the approach that are worth
pointing out.
-In the Samba3 msrpc code we used explicit parse strucrures for all
+In the Samba3 msrpc code we used explicit parse structures for all
msrpc functions. The problem is that we didn't just put all of the
real variables in these structures, we also put in all the artifacts
as well. A good example is the security descriptor strucrure that
*NOT* be in the interface structure.
In Samba3 there were unwritten rules about which variables in a
-strucrure a high level caller has to fill in and which ones are filled
+structure a high level caller has to fill in and which ones are filled
in by the marshalling code. In Samba4 those rules are gone, because
the redundent artifact variables are gone. The high level caller just
sets up the real variables and the marshalling code worries about
each SMB.
As an example go and have a look at reply_getatr_send() and
-reply_getatr() in smbd/reply.c. Read them? Good.
+reply_getatr() in smb_server/reply.c. Read them? Good.
Notice that reply_getatr() sets up the req->async structure to contain
the send function. Thats how the backend gets to do an async reply, it
The format is:
- TRANSPORT:host:[flags]
+ TRANSPORT:host[flags]
where TRANSPORT is either ncacn_np for SMB or ncacn_ip_tcp for RPC/TCP
-"host" is an IP or hostname or netbios name
+"host" is an IP or hostname or netbios name. If the binding string
+identifies the server side of an endpoint, "host" may be an empty
+string.
"flags" can include a SMB pipe name if using the ncacn_np transport or
a TCP port number if using the ncacn_ip_tcp transport, otherwise they
other recognised flags are:
- sign : enable ntlmssp signing
- seal : enable ntlmssp sealing
- validate: enable the NDR validator
- print: enable debugging of the packets
- bigendian: use bigendian RPC
+ sign : enable ntlmssp signing
+ seal : enable ntlmssp sealing
+ spnego : use SPNEGO instead of NTLMSSP authentication
+ krb5 : use KRB5 instead of NTLMSSP authentication
+ connect : enable rpc connect level auth (auth, but no sign or seal)
+ validate : enable the NDR validator
+ print : enable debugging of the packets
+ bigendian : use bigendian RPC
+ padcheck : check reply data for non-zero pad bytes
-For example, these all connect to the samr pipe:
+Here are some examples:
ncacn_np:myserver
- ncacn_np:myserver:samr
- ncacn_np:myserver:samr,seal
- ncacn_np:myserver:\pipe\samr
- ncacn_np:myserver:/pipe/samr
ncacn_np:myserver[samr]
ncacn_np:myserver[\pipe\samr]
ncacn_np:myserver[/pipe/samr]
- ncacn_np:myserver:[samr,sign,print]
- ncacn_np:myserver:[\pipe\samr,sign,seal,bigendian]
- ncacn_np:myserver:[/pipe/samr,seal,validate]
-
+ ncacn_np:myserver[samr,sign,print]
+ ncacn_np:myserver[sign,spnego]
+ ncacn_np:myserver[\pipe\samr,sign,seal,bigendian]
+ ncacn_np:myserver[/pipe/samr,seal,validate]
+ ncacn_np:
+ ncacn_np:[/pipe/samr]
ncacn_ip_tcp:myserver
- ncacn_ip_tcp:myserver:1024
ncacn_ip_tcp:myserver[1024]
- ncacn_ip_tcp:myserver:[1024,sign,seal]
+ ncacn_ip_tcp:myserver[sign,seal]
+ ncacn_ip_tcp:myserver[spnego,seal]
IDEA: Maybe extend UNC names like this?
smbclient //server/share
- smbclient //server/share:[sign,seal,spnego]
+ smbclient //server/share[sign,seal,spnego]
DCERPC Handles
--------------
- msrpc
-- use _p talloc varients
-
don't zero structures! avoid ZERO_STRUCT() and talloc_zero()
test timezone handling by using a server in different zone from client
-don't just use any old TALLOC_CTX, use the right one!
-
do {} while (0) system
NT_STATUS_IS_OK() is NOT the opposite of NT_STATUS_IS_ERR()
need to implement secondary parts of trans2 and nttrans in server and
client
-add talloc_steal() to move a talloc ptr from one pool to another
-
document access_mask in openx reply
check all capabilities and flag1, flag2 fields (eg. EAs)
svn instructions
-test commit
+Ideas
+-----
+
+ - store all config in config.ldb
+
+ - load from smb.conf if modtime changes
+
+ - dump full system config with ldbsearch
+
+ - will need the ability to form a ldif difference file
+
+ - advanced web admin via a web ldb editor
+
+ - normal web admin via web forms -> ldif
+
+ - config.ldb will replace smb.conf, secrets.tdb, shares.tdb etc
+
+ - subsystems in smbd will load config parameters for a share
+ using ldbsearch at tconx time
+
+ - need a loadparm equivalent module that provides parameter defaults
+
+ - start smbd like this: "smbd -C tdb://etc/samba/config.ldb" or
+ "smbd -C ldapi://var/run/ldapi"
+
+ - write a tool that generates a template ldap schema from an existing
+ ldb+tdb file
+
+ - no need to HUP smbd to reload config
+
+ - how to handle configuration comments? same problem as SWAT
+
+
+BUGS:
+ add a test case for last_entry_offset in trans2 find interfaces
+ conn refused
+ connect -> errno
+ no 137 resolution not possible
+ should not fallback to anon when pass supplied
+ should check pass-thu cap bit, and skip lots of tests
+ possibly allow the test suite to say "allow oversized replies" for
+ trans2 and other calls
+ handle servers that don't have the setattre call in torture
+ add max file coponent length test and max path len test
+ check for alloc failure in all core reply.c and trans2.c code where
+ allocation size depends on client parameter
+
+case-insenstive idea:
+ all filenames on disk lowercase
+ real case in extended attribute
+ keep cache of what dirs are all lowercase
+ when searching for name, don't search if dir is definately all lowercase
+ when creating file, use dnotify to tell if someone else creates at
+ same time
+
+solve del *.* idea:
+ make mangle cache dynamic size
+ fill during a dir scan
+ setup a timer
+ destroy cache after 30 sec
+ destroy if a 2nd dir scan happens on same dir
+
git.samba.org / ira / wip.git / blobdiff