-*- indented-text -*-

BUGS ---------------------------------------------------------------

Do not rely on having a group called "nobody"

FEATURES ------------------------------------------------------------

Use chroot only if supported

Allow supplementary groups in rsyncd.conf 2002/04/09

Handling IPv6 on old machines

Other IPv6 stuff:

Add ACL support 2001/12/02

Lazy directory creation

proxy authentication 2002/01/23

SOCKS 2002/01/23

FAT support

Allow forcing arbitrary permissions 2002/03/12

--diff david.e.sewell 2002/03/15

Add daemon --no-fork option

Create more granular verbosity jw 2003/05/15

DOCUMENTATION --------------------------------------------------------

Keep list of open issues and todos on the web site

Perhaps redo manual as SGML

LOGGING --------------------------------------------------------------

Memory accounting

Improve error messages

Better statistics: Rasmus 2002/03/08

Perhaps flush stdout like syslog

Log deamon sessions that just list modules

Log child death on signal

Log errors with function that reports process of origin

verbose output David Stein 2001/12/20

internationalization

DEVELOPMENT --------------------------------------------------------

Handling duplicate names

Use generic zlib 2002/02/25

TDB: 2002/03/12

Splint 2002/03/12

PERFORMANCE ----------------------------------------------------------

File list structure in memory

Traverse just one directory at a time

Allow skipping MD4 file_sum 2002/04/08

Accelerate MD4

TESTING --------------------------------------------------------------

Torture test

Cross-test versions 2001/08/22

Test on kernel source

Test large files

Create mutator program for testing

Create configure option to enable dangerous tests

If tests are skipped, say why.

Test daemon feature to disallow particular options.

Create pipe program for testing

Create test makefile target for some tests

RELATED PROJECTS -----------------------------------------------------

rsyncsh

http://rsync.samba.org/rsync-and-debian/

rsyncable gzip patch

rsyncsplit as alternative to real integration with gzip?

reverse rsync over HTTP Range

BUGS ---------------------------------------------------------------

Do not rely on having a group called "nobody"

http://www.linuxbase.org/spec/refspecs/LSB_1.1.0/gLSB/usernames.html

On Debian it's "nogroup"

-- --

FEATURES ------------------------------------------------------------

Use chroot only if supported

If the platform doesn't support it, then don't even try.

If running as non-root, then don't fail, just give a warning.

(There was a thread about this a while ago?)

http://lists.samba.org/pipermail/rsync/2001-August/thread.html

http://lists.samba.org/pipermail/rsync/2001-September/thread.html

-- --

Allow supplementary groups in rsyncd.conf 2002/04/09

Perhaps allow supplementary groups to be specified in rsyncd.conf;

then make the first one the primary gid and all the rest be

supplementary gids.

-- --

Handling IPv6 on old machines

The KAME IPv6 patch is nice in theory but has proved a bit of a

nightmare in practice. The basic idea of their patch is that rsync

is rewritten to use the new getaddrinfo()/getnameinfo() interface,

rather than gethostbyname()/gethostbyaddr() as in rsync 2.4.6.

Systems that don't have the new interface are handled by providing

our own implementation in lib/, which is selectively linked in.

The problem with this is that it is really hard to get right on

platforms that have a half-working implementation, so redefining

these functions clashes with system headers, and leaving them out

breaks. This affects at least OSF/1, RedHat 5, and Cobalt, which

are moderately improtant.

Perhaps the simplest solution would be to have two different files

implementing the same interface, and choose either the new or the

old API. This is probably necessary for systems that e.g. have

IPv6, but gethostbyaddr() can't handle it. The Linux manpage claims

this is currently the case.

In fact, our internal sockets interface (things like

open_socket_out(), etc) is much narrower than the getaddrinfo()

interface, and so probably simpler to get right. In addition, the

old code is known to work well on old machines.

We could drop the rather large lib/getaddrinfo files.

-- --

Other IPv6 stuff:

Implement suggestions from http://www.kame.net/newsletter/19980604/

and ftp://ftp.iij.ad.jp/pub/RFC/rfc2553.txt

If a host has multiple addresses, then listen try to connect to all

in order until we get through. (getaddrinfo may return multiple

addresses.) This is kind of implemented already.

Possibly also when starting as a server we may need to listen on

multiple passive addresses. This might be a bit harder, because we

may need to select on all of them. Hm.

-- --

Add ACL support 2001/12/02

Transfer ACLs. Need to think of a standard representation.

Probably better not to even try to convert between NT and POSIX.

Possibly can share some code with Samba.

NOTE: there is a patch that implements this in the "patches" subdir.

-- --

Lazy directory creation

With the current common --include '*/' --exclude '*' pattern, people

can end up with many empty directories. We might avoid this by

lazily creating such directories.

-- --

proxy authentication 2002/01/23

Allow RSYNC_PROXY to be http://user:pass@proxy.foo:3128/, and do

HTTP Basic Proxy-Authentication.

Multiple schemes are possible, up to and including the insanity that

is NTLM, but Basic probably covers most cases.

-- --

SOCKS 2002/01/23

Add --with-socks, and then perhaps a command-line option to put them

on or off. This might be more reliable than LD_PRELOAD hacks.

-- --

FAT support

rsync to a FAT partition on a Unix machine doesn't work very well at

the moment. I think we get errors about invalid filenames and

perhaps also trying to do atomic renames.

I guess the code to do this is currently #ifdef'd on Windows;

perhaps we ought to intelligently fall back to it on Unix too.

-- --

Allow forcing arbitrary permissions 2002/03/12

On 12 Mar 2002, Dave Dykstra <dwd@bell-labs.com> wrote:

> If we would add an option to do that functionality, I

> would vote for one that was more general which could mask

> off any set of permission bits and possibly add any set of

> bits. Perhaps a chmod-like syntax if it could be

> implemented simply.

I think that would be good too. For example, people uploading files

to a web server might like to say

rsync -avzP --chmod a+rX ./ sourcefrog.net:/home/www/sourcefrog/

Ideally the patch would implement as many of the gnu chmod semantics

as possible. I think the mode parser should be a separate function

that passes back something like (mask,set) description to the rest

of the program. For bonus points there would be a test case for the

parser.

Possibly also --chown

(Debian #23628)

NOTE: there is a patch that implements this in the "patches" subdir.

-- --

--diff david.e.sewell 2002/03/15

Allow people to specify the diff command. (Might want to use wdiff,

gnudiff, etc.)

Just diff the temporary file with the destination file, and delete

the tmp file rather than moving it into place.

Interaction with --partial.

Security interactions with daemon mode?

-- --

Add daemon --no-fork option

Very useful for debugging. Also good when running under a

daemon-monitoring process that tries to restart the service when the

parent exits.

-- --

Create more granular verbosity jw 2003/05/15

Control output with the --report option.

The option takes as a single argument (no whitespace) a

comma delimited lists of keywords.

This would separate debugging from "logging" as well as

fine grained selection of statistical reporting and what

actions are logged.

http://lists.samba.org/archive/rsync/2003-May/006059.html

-- --

DOCUMENTATION --------------------------------------------------------

Keep list of open issues and todos on the web site

-- --

Perhaps redo manual as SGML

The man page is getting rather large, and there is more information

that ought to be added.

TexInfo source is probably a dying format.

Linuxdoc looks like the most likely contender. I know DocBook is

favoured by some people, but it's so bloody verbose, even with emacs

support.

-- --

LOGGING --------------------------------------------------------------

Memory accounting

At exit, show how much memory was used for the file list, etc.

Also we do a wierd exponential-growth allocation in flist.c. I'm

not sure this makes sense with modern mallocs. At any rate it will

make us allocate a huge amount of memory for large file lists.

-- --

Improve error messages

If we hang or get SIGINT, then explain where we were up to. Perhaps

have a static buffer that contains the current function name, or

some kind of description of what we were trying to do. This is a

little easier on people than needing to run strace/truss.

"The dungeon collapses! You are killed." Rather than "unexpected

eof" give a message that is more detailed if possible and also more

helpful.

If we get an error writing to a socket, then we should perhaps

continue trying to read to see if an error message comes across

explaining why the socket is closed. I'm not sure if this would

work, but it would certainly make our messages more helpful.

What happens if a directory is missing -x attributes. Do we lose

our load? (Debian #28416) Probably fixed now, but a test case would

be good.

When running as a daemon, some errors should both be returned to the

user and logged. This will make interacting with a daemon less

cryptic.

-- --

Better statistics: Rasmus 2002/03/08

<Rasmus>

hey, how about an rsync option that just gives you the

summary without the list of files? And perhaps gives

more information like the number of new files, number

of changed, deleted, etc. ?

<mbp>

nice idea there is --stats but at the moment it's very

tridge-oriented rather than user-friendly it would be

nice to improve it that would also work well with

--dryrun

-- --

Perhaps flush stdout like syslog

Perhaps flush stdout after each filename, so that people trying to

monitor progress in a log file can do so more easily. See

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=48108

-- --

Log deamon sessions that just list modules

At the connections that just get a list of modules are not logged,

but they should be.

-- --

Log child death on signal

If a child of the rsync daemon dies with a signal, we should notice

that when we reap it and log a message.

-- --

Log errors with function that reports process of origin

Use a separate function for reporting errors; prefix it with

"rsync:" or "rsync(remote)", or perhaps even "rsync(local

generator): ".

-- --

verbose output David Stein 2001/12/20

At end of transfer, show how many files were or were not transferred

correctly.

-- --

internationalization

Change to using gettext(). Probably need to ship this for platforms

that don't have it.

Solicit translations.

Does anyone care? Before we bother modifying the code, we ought to

get the manual translated first, because that's possibly more useful

and at any rate demonstrates desire.

-- --

DEVELOPMENT --------------------------------------------------------

Handling duplicate names

Some folks would like rsync to be deterministic in how it handles

duplicate names that come from mering multiple source directories

into a single destination directory; e.g. the last name wins. We

could do this by switching our sort algorithm to one that will

guarantee that the names won't be reordered. Alternately, we could

assign an ever-increasing number to each item as we insert it into

the list and then make sure that we leave the largest number when

cleaning the file list (see clean_flist()). Another solution would

be to add a hash table, and thus never put any duplicate names into

the file list (and bump the protocol to handle this).

-- --

Use generic zlib 2002/02/25

Perhaps don't use our own zlib.

Advantages:

- will automatically be up to date with bugfixes in zlib

- can leave it out for small rsync on e.g. recovery disks

- can use a shared library

- avoids people breaking rsync by trying to do this themselves and

messing up

Should we ship zlib for systems that don't have it, or require

people to install it separately?

Apparently this will make us incompatible with versions of rsync

that use the patched version of rsync. Probably the simplest way to

do this is to just disable gzip (with a warning) when talking to old

versions.

-- --

TDB: 2002/03/12

Rather than storing the file list in memory, store it in a TDB.

This *might* make memory usage lower while building the file list.

Hashtable lookup will mean files are not transmitted in order,

though... hm.

This would neatly eliminate one of the major post-fork shared data

structures.

-- --

Splint 2002/03/12

Build rsync with SPLINT to try to find security holes. Add

annotations as necessary. Keep track of the number of warnings

found initially, and see how many of them are real bugs, or real

security bugs. Knowing the percentage of likely hits would be

really interesting for other projects.

-- --

PERFORMANCE ----------------------------------------------------------

File list structure in memory

Rather than one big array, perhaps have a tree in memory mirroring

the directory tree.

This might make sorting much faster! (I'm not sure it's a big CPU

problem, mind you.)

It might also reduce memory use in storing repeated directory names

-- again I'm not sure this is a problem.

-- --

Traverse just one directory at a time

Traverse just one directory at a time. Tridge says it's possible.

At the moment rsync reads the whole file list into memory at the

start, which makes us use a lot of memory and also not pipeline

network access as much as we could.

-- --

Allow skipping MD4 file_sum 2002/04/08

If we're doing a local transfer, or using -W, then perhaps don't

send the file checksum. If we're doing a local transfer, then

calculating MD4 checksums uses 90% of CPU and is unlikely to be

useful.

We should not allow it to be disabled separately from -W, though

as it is the only thing that lets us know when the rsync algorithm

got out of sync and messed the file up (i.e. if the basis file

changed between checksum generation and reception).

-- --

Accelerate MD4

Perhaps borrow an assembler MD4 from someone?

Make sure we call MD4 with properly-sized blocks whenever possible

to avoid copying into the residue region?

-- --

TESTING --------------------------------------------------------------

Torture test

Something that just keeps running rsync continuously over a data set

likely to generate problems.

-- --

Cross-test versions 2001/08/22

Part of the regression suite should be making sure that we

don't break backwards compatibility: old clients vs new

servers and so on. Ideally we would test both up and down

from the current release to all old versions.

Run current rsync versions against significant past releases.

We might need to omit broken old versions, or versions in which

particular functionality is broken

It might be sufficient to test downloads from well-known public

rsync servers running different versions of rsync. This will give

some testing and also be the most common case for having different

versions and not being able to upgrade.

The new --protocol option may help in this.

-- --

Test on kernel source

Download all versions of kernel; unpack, sync between them. Also

sync between uncompressed tarballs. Compare directories after

transfer.

Use local mode; ssh; daemon; --whole-file and --no-whole-file.

Use awk to pull out the 'speedup' number for each transfer. Make

sure it is >= x.

-- --

Test large files

Sparse and non-sparse

-- --

Create mutator program for testing

Insert bytes, delete bytes, swap blocks, ...

-- --

Create configure option to enable dangerous tests

-- --

If tests are skipped, say why.

-- --

Test daemon feature to disallow particular options.

-- --

Create pipe program for testing

Create pipe program that makes slow/jerky connections for

testing Versions of read() and write() that corrupt the

stream, or abruptly fail

-- --

Create test makefile target for some tests

Separate makefile target to run rough tests -- or perhaps

just run them every time?

-- --

RELATED PROJECTS -----------------------------------------------------

rsyncsh

Write a small emulation of interactive ftp as a Pythonn program

that calls rsync. Commands such as "cd", "ls", "ls *.c" etc map

fairly directly into rsync commands: it just needs to remember the

current host, directory and so on. We can probably even do

completion of remote filenames.

-- --

http://rsync.samba.org/rsync-and-debian/

-- --

rsyncable gzip patch

Exhaustive, tortuous testing

Cleanups?

-- --

rsyncsplit as alternative to real integration with gzip?

-- --

reverse rsync over HTTP Range

Goswin Brederlow suggested this on Debian; I think tridge and I

talked about it previous in relation to rproxy.

Addendum: It looks like someone is working on a version of this:

http://zsync.moria.org.uk/

-- --